MM-M02 Rev.000 5th Submission (22.08.13)_NIGRIE

JAIPRAKASH POWER VENTURES LIMITED 2X660MW JAYPEE NIGRIE SUPER THERMAL POWER PROJECT P.O.-NIGRIE, DIST.-SINGRAULI, M.P.-486669

MM-M02 Maintenance manual for

Boiler Ducts and Dampers L&T-MHI BOILERS PRIVATE LIMITED 12/4, Delhi Mathura Road Near Sarai Khwaja Chowk Faridabad-121003, Haryana, India Tel: +91 129 4291000/1001 Fax: +91 129 429 1222 www.Lntmhi.com

Registered office: L&T House, N.M. Marg Ballard Estate Mumbai-400 001, India

Boiler Ducts and Dampers (MM-M02)

Contents Safety 1 General 2 Specifications 3 Preventive Maintenance 4 Disassembly and Reassembly 5 Corrective Maintenance 6 Recommended Lubrication 7 Appendices

Contents

Contents Revision Record ··············································································· i Copyright ························································································ ii Contact Address ·············································································· iii Personnel to whom this Manual is directed ············································ iv List of Manuals ················································································· v Abbreviations ················································································· vii Warranty ························································································ ix Limitation of Liability ········································································· xi Important Information ······································································· xiii Arrangement of the System Maintenance Manual ································· xvi

Chapter1

Safety ____________________________

1.1

Features of Boiler Safety ······················································ 1-1

1.2

Description of Warnings ······················································· 1-2 1.2.1

Definitions of “Serious Injury”, “Minor Injury”, “Serious Damage to Property”, and “Minor Damage to Property” ····· 1-3

1.2.2

Symbols ································································· 1-4

1.2.3

Hazard Warning Label ··············································· 1-5

1.2.4

Hazard Area ···························································· 1-7

1.3

Risk Assessment Standard ·················································· 1-8

1.4

Safety Measures ······························································ 1-10 1.4.1

Work Permit System (Lockout/Tagout) ························· 1-10

1.4.2

General Cautions on Personnel in Working Area············ 1-11

1.4.2.1 Cautions against Rotating Equipment ·························· 1-11 1.4.2.2 Cautions against Electrical Equipment ························· 1-11 1.4.2.3 Cautions against High Temperature Sections ················ 1-12 1.4.2.4 Cautions against Steam Leakage in the Plant ··············· 1-13 1.4.2.5 Cautions against Oil Leak in the Plant ························ 1-14 1.4.2.6 Cautions against Chemicals ······································ 1-14 MM-M02 Rev.000 (17.07.13)

1.4.2.7 Cautions against Combustible Materials/Storage Areas ··· 1-15 1.4.2.8 Cautions against Lack of Oxygen ······························· 1-15 1.4.2.9 Cautions against Lifting Heavy Object ························· 1-16 1.4.2.10Caution against Sharp Objects·································· 1-16 1.4.2.11Cautions for using a Fork Lift Truck ···························· 1-16

Boiler Ducts and Dampers 1

Contents

Chapter1

Safety (Cont’d. from previous page..) 1.4.2.12Cautions using Crane ············································· 1-17 1.4.2.13Disposal ······························································ 1-18

1.5

Emergency Measures························································ 1-19 1.5.1

Evacuation in an Emergency Case ····························· 1-19

1.5.1.1 Evacuation Route ··················································· 1-19 1.5.1.2 Evacuation of Disabled persons ································· 1-19 1.5.1.3 Evacuation from the Power House······························ 1-20

1.6

Chapter2

1.5.2

Fire Accident ························································· 1-21

1.5.3

Earthquake ··························································· 1-22

1.5.4

Explosion Accident ·················································· 1-22

Qualification and Training ··················································· 1-23

General __________________________

2.1

Purpose ··········································································· 2-1

2.2

References ······································································· 2-1

2.3

Overview of the Boiler Ducts and Dampers······························· 2-2

2.4

Construction ······································································ 2-8 Ducts ····································································· 2-8

2.4.2

Stiffeners and Struts ·················································· 2-9

2.4.3

Guide Vanes···························································· 2-9

2.4.4

Expansion Joints ······················································ 2-9

2.4.5

Duct Supports ························································ 2-10

2.4.6

Dampers ······························································ 2-11

Specifications _____________________

MM-M02 Rev.000 (17.07.13)

Chapter3

2.4.1

Boiler Ducts and Dampers 2

Contents

Chapter4 4.1

4.2

4.3

Chapter5

Preventive Maintenance _____________ Prerequisites ····································································· 4-1 4.1.1

Scheduling ······························································ 4-1

4.1.2

Departmental Interface/Notification ······························· 4-2

4.1.3

Isolation of Equipment ··············································· 4-2

4.1.4

Safety Precautions ···················································· 4-2

Routine Maintenance ·························································· 4-3 4.2.1

Preparation ····························································· 4-3

4.2.2

Inspection and Maintenance ······································· 4-4

Annual Outage Maintenance ··············································· 4-12 4.3.1

Preparation ··························································· 4-12

4.3.2

Inspection and Maintenance ····································· 4-13

Disassembly and Reassembly _______

5.1

Disassembly and Reassembly of a Multi-Louver Damper············· 5-1

5.2

Disassembly and Reassembly of a Butterfly Damper ·················· 5-7

5.3

Disassembly and Reassembly of a 3-Way Damper ·················· 5-11

5.4

Disassembly and Reassembly of a Wind Box Damper ·············· 5-14

5.5

Disassembly and Reassembly of a Guillotine Damper··············· 5-18

Chapter6

Corrective Maintenance _____________

6.1

Prerequisites ····································································· 6-1

6.2

Preparation ······································································· 6-2

6.3

Troubleshooting ································································· 6-2

Recommended Lubrication __________

MM-M02 Rev.000 (17.07.13)

Chapter7

Boiler Ducts and Dampers 3

Contents

Appendices Appendix A

Torque Chart ························································· A-1

Appendix B

Recommended Spare Parts ······································ B-1

Appendix C

Special Tools ························································· C-1

Appendix D

Coupling Alignment ················································ D-1

Appendix E

Applicable Vendor Drawings ····································· E-1

MM-M02 Rev.000 (17.07.13)

List Of Figures Figure1-1

Types of Hazard Warning Labels ································ 1-6

Figure 1-2

Danger Zone in Boiler Area ······································· 1-9

Figure 2-1

Air and Flue Gas Flow Diagram ·································· 2-5

Figure 2-2

Boiler Cooling and Sealing Air System Flow Diagram ······ 2-6

Figure 2-3

Arrangement of Air and Flue Gas Ducts ······················· 2-7

Figure 2-4

Construction of a Typical Air/Flue Gas Duct ················· 2-19

Figure 2-5

Construction of a Typical Non-Metallic Expansion Joint (1 of 2)································································ 2-20

Figure 2-6

Construction of a Typical Non-Metallic Expansion Joint (2 of 2)································································ 2-21

Figure 2-7

Typical Arrangement of Air and Gas Duct Supports ······· 2-22

Figure 2-8

Typical Arrangement of Hanger Supports in Air and Gas Ducts ································································· 2-23

Figure 2-9

Construction of a Multi-Louver Damper ······················ 2-24

Figure 2-10

Construction of a Duplex Multi-Louver Damper ············ 2-25

Figure 2-11

Construction of a Butterfly Damper···························· 2-26

Figure 2-12

Construction of a 3-Way Damper Assembly ················ 2-27

Figure 2-13

Construction of Windbox Burner Damper Assembly ······ 2-28

Figure 2-14

Construction of AA-Port Damper Assembly ················· 2-29

Figure 2-15

Construction of Guillotine Damper Assembly (1/2) ········ 2-30

Figure 2-16

Construction of Guillotine Damper Assembly (2/2) ········ 2-31

Figure E-1

FDF Outlet Damper ················································ E-2

Figure E-2

RAPH Outlet Secondary Air Damper ·························· E-3

Figure E-3

Burner Windbox Secondary Air Damper ······················ E-4

Figure E-4

RAPH Inlet Cold Primary Air Damper ·························· E-5

Figure E-5

RAPH Outlet Hot Primary Damper ····························· E-6

Boiler Ducts and Dampers 4

Contents

List Of Figures (Cont’d. from previous page..) Figure E-6

Pulverizer Inlet Hot Primary Air Damper ······················ E-7

Figure E-7

PAF Outlet Cold Primary Air Damper ·························· E-8

Figure E-8

Pulverizer Inlet Cold Primary Air Damper ····················· E-9

Figure E-9

RAPH Inlet Gas Damper ········································· E-10

Figure E-10

RAPH Outlet Gas Damper ······································ E-11

Figure E-11

IDF Outlet Damper ················································ E-12

Figure E-12

Pulverizer Inlet Hot Primary Air Shut-Off Damper·········· E-13

Figure E-13

Pulverizer Inlet Cold Primary Air Shut-Off Damper ········ E-14

Figure E-14

ESP Inlet Isolation Valve ········································· E-15

Figure E-15

Secondary Pass Gas Control Damper ······················· E-16

Figure E-16

Flame Detector Cooling Fan Inlet Damper ·················· E-17

List Of Tables Boiler Risk Assessment Standard ······························· 1-8

Table 3-1

Louver Dampers ····················································· 3-1

Table 3-2

Butterfly Dampers ··················································· 3-4

Table 3-3

Flap Type Dampers ················································· 3-5

Table 3-4

Guillotine Type Dampers··········································· 3-6

Table 3-5

3-Way Dampers ······················································ 3-7

Table 3-6

Design Pressure for Air & Gas Ducts ··························· 3-7

Table 3-7

Non-Metallic Expansion Joints ··································· 3-8

Table 4-1

Routine Maintenance Checklist ·································· 4-9

Table 4-2

Annual Outage Maintenance Checklist ······················· 4-24

Table 4-3

Abnormal Condition after Maintenance Checklist ·········· 4-28

Table 6-1

Troubleshooting – Ducts and Dampers ························ 6-3

Table 7-1

Recommended Lubrication for Dampers ······················ 7-1

Table A-1

Torque Chart ························································· A-1

MM-M02 Rev.000 (17.07.13)

Table 1-1

Boiler Ducts and Dampers 5

-*

Revision Record Description of Revision

Revision Issue Date

Date Revised

Pages Inserted

MM-M02 Rev.000 (17.07.13)

Page Number

Boiler Ducts and Dampers

i

Copyright COPYRIGHT © 2011, L&T-MHI BOILERS PRIVATE LTD. ALL RIGHTS RESERVED. ANY REPRODUCTION IS EXPRESSLY PROHIBITED. Contents of this manual are protected by Indian copyright laws.



All copyright, trade secrets, and other proprietary and intellectual property rights in the documents provided by L&T-MHI Boilers Private Ltd. (“LMB”) (including safety-and-instruction manuals) are at all times owned and reserved by LMB. Subject to your compliance with the restrictions set forth below, LMB grants to you a limited, non-exclusive license in the copyright for the sole purpose of allowing you to use, operate, maintain and inspect the Plant.



Use, copying or other form of reproduction of the whole or part of the documents provided by LMB (including safety-and-instruction manuals) for any purpose other than the purpose described above without LMB’s prior written consent is strictly prohibited.



The act of rewriting, translating, modifying, revising, creating electronic copies, uploading, selling, sublicensing, or otherwise disclosing the whole or part of the manual is strictly prohibited.



Except as specifically set forth above, no right, title or license to the documents provided by LMB, whether arising from contract, implication, and estoppel or otherwise, is being granted or otherwise transferred.

MM-M02 Rev.000 (17.07.13)



Boiler Ducts and Dampers

ii

Contact Address For any question or any clarification required, please do not hesitate to contact LMB through the following address (es).

For Support before Operation: L&T-MHI BOILERS PRIVATE LIMITED. LARSEN & TOUBRO 12/4 DELHI MATHURA ROAD FARIDABAD PIN – 121003 HARYANA INDIA Tel: +91 129 4291000/1001 Fax: +91 129 429 1222 Website: www.lntmhi.com

For Support after Commissioning and in an Emergency L&T-MHI BOILERS PRIVATE LIMITED. LARSEN & TOUBRO 12/4 DELHI MATHURA ROAD FARIDABAD PIN – 121003 HARYANA

MM-M02 Rev.000 (17.07.13)

INDIA Tel: +91 129 4291000/1001 Fax: +91 129 429 1222 Website: www.lntmhi.com

Boiler Ducts and Dampers

iii

P e r s o n n e l t o w h o m t h is Manual is directed This Manual has been prepared for all personnel who will participate in the operation and maintenance of the plant, and other related mechanical plant and equipment installed. In this Manual, LMB classifies personnel into the following two classes based on their ability, experience and their approach towards the safety of personnel, and the plant installed. Only the personnel recognized by the Customer as trained personnel are allowed to perform the operation and maintenance as specified in the manuals. Maintainers and Operators are required to have read and understood the contents of the safety, operation, and maintenance manuals and sufficiently understand the work procedures before actually starting their tasks.

Operator

Operators following the instructions of their supervisor or the Shift Charge Engineer are permitted to handle materials to be used in the operation of the plant. Operators are allowed to turn on the power supply, startup equipment, open up or remove covers or panels on receipt of an instruction or authorization from their superior. Operators are permitted access to the emergency stop devices following instructions given by their superior when dangerous or hazardous situations are recognized.

MM-M02 Rev.000 (17.07.13)

Maintainer

Maintainers are permitted to perform maintenance on the plant. They will also perform troubleshooting routine and periodical inspections of the installed equipment. In addition, the maintainer will also work under the supervision of LMB during on-the-job training and annual maintenance and overhauling in case LMB is requested to witness periodical inspections, etc. Maintainers MUST have attended the training program initially provided by LMB and subsequently by the Customer, and they must have obtained the necessary knowledge and maintenance skills to understand the characteristics of their tasks before actually starting their work. Boiler Ducts and Dampers

iv

List of Manuals LIST OF OPERATION MANUALS Module Number

Description

OPM-01

Boiler Feed Water System

OPM-02

Boiler Pressure Parts, Main Steam and Reheat Steam System

OPM-03

Air and Flue Gas System

OPM-04

Fuel Firing System

OPM-05

Soot Blowing System

OPM-06

Clean-up System

OPM-07

Auxiliary Steam System

OPM-08

CCCW System

OPM-09

Chemical Injection System LIST OF MAINTENANCE MANUALS

Module Number

Description

MM-M01

Boiler

MM-M02

Boiler Ducts and Dampers

MM-M03

Pulverizer (including Bunker, Coal Gate and Rotary Separator)

MM-M04

Burners (Coal, Oil and Igniter) LIST OF VENDOR MANUALS

MM-M02 Rev.000 (17.07.13)

Manual Code

Description

VM-1

Fans & Heat Exchangers

VM-2

Pulverizer

VM-3

Soot Blower

VM-4

Valves

VM-5

Pumps

VM-6

Coal Feeder

VM-7

Auxiliary Boiler

VM-8

Dampers & Ducting Accessories

VM-9

Fuel Oil System & Dosing System

VM-10

Windbox

Boiler Ducts and Dampers

v

Cont’d. from previous page.. LIST OF VENDOR MANUALS Manual Code

Description

Nitrogen Preservation System & Other Auxiliaries

VM-12

Piping & Pressure Parts

VM-13

HT Motors & Other Electrical Accessories

VM-14

Instrumentation Packages

MM-M02 Rev.000 (17.07.13)

VM-11

Boiler Ducts and Dampers

vi

Abbreviations Abb.

Expanded Form

Expanded Form

AA

Additional Air

DSH

De-superheater

ACWP

Auxiliary Cooling Water Pump

ECO

Economizer

AOP

Auxiliary Oil Pump

EOP

Emergency Oil Pump

APC

Automatic Plant Control

EP/ESP

Electrostatic Precipitator

ASL

Automatic Selection

FCB

Fast Cut Back

AVT

All Volatile Treatment

FCV

Flow Control valve

BCP

Boiler Circulating Pump

FD

Forced Draft

BFD

Butterfly Damper

FDF

Forced Draft Fan

BFPT

Boiler Feed Pump Turbine

GSC

Gland Steam Condenser

BI

Boiler Input Control Mode

GV

Governing Valve

Boiler Maximum Continuous

HI

BMCR

Rating

High

BMS

Burner Management System

HP

High Pressure

BOP

Balance of Plant

I&C

Instrument and control

BP

Break Point

ICV

Interceptor Valve

CCCW

Closed Circuit Cooling Water

ID

Induced Draft

CCCWP

Closed Circuit Cooling Water

IDF

Induced Draft Fan

Pump

MM-M02 Rev.000 (17.07.13)

Abb.

CCR

Central Control Room

IP

Intermediate Pressure

CP

Condensate Pump

LCV

Level Control Valve

CPU

Condensate Polisher Unit

LMB

L&T-MHI Boilers Pvt. Ltd.

CV

Control Valve

LO

Low

CVP

Condenser Vacuum Pump

LP

Low Pressure

CWP

Circulation Water Pump

LRSB

Long Retractable Soot Blower

CWT

Combined Water Treatment

MDBFP

Motor Driven Boiler Feed Pump

DCS

Distributed Control System

MDBFP

Motor Driven Boiler Feed Pump

BP

Booster Pump

DE

Driving End

MFT

Master Fuel Trip

DEH

Digital Electric Hydraulic

MLD

Multi-Louver Damper

DPI

Differential Pressure Indicator

MOP

Main Oil Pump

DPT

Differential Pressure Transmitter

MOV

Motor Operated Valve

Boiler Ducts and Dampers

vii

Cont’d. from previous page.. Abb.

Expanded Form

Abb.

Expanded Form

MSDS

Material Safety Data Sheet

PVC

Polyvinyl Chloride

MSV

Main Stop Valve

RAPH

Regenerative Air Preheater

NDE

Non Driving End

RH

Reheater

NDT

Non-Destructive Testing

RSV

Reheat Stop Valve

NRV

Non Return Valve

SB

Soot Blower

OPS

Operator Station

SG

Sub Group

PA

Primary Air

SH

Superheater

PAF

Primary Air Fan

SP

Secondary Pass

PB

Push Button

TB Valve

Turbine Bypass Valve

PCV

Pressure Control Valve

TDBFP

Turbine Driven Boiler Feed Pump

PERM

Permissive

TDBFP

Turbine Driven Boiler Feed Pump

BP

Booster Pump

Pressure Indicator

TCV

Temperature Control Valve

PLC

Programmable Logic Controller

TE

Temperature Element

PPE

Personal Protective Equipment

TOP

Turning Oil Pump

PS

Pressure Switch

TSF

Twin Seal Flap

PT

Pressure Transmitter

WC

Water Column

PTW

Permit to Work

WS

Water Separator

PULV

Pulverizer

WSDT

Water Separator Drain Tank

MM-M02 Rev.000 (17.07.13)

PI

Boiler Ducts and Dampers

viii

Warranty The provisions set forth in this section are in addition to all liability and warranty disclaimers and limitations set forth in BID Document No:JPVL-JNSTPP-SG-01 (the “Contract”). The express warranties set forth in the Contract (“Contract Warranties”) are the exclusive warranties for the Plant and are in lieu of any and all other warranties, express or implied, including without limitation, any guarantee or implied warranty of merchantability or fitness for a particular purpose, whether arising under law or from course of performance, course of dealing, or usage of trade. All other guarantees and warranties are hereby expressly excluded by LMB and forever waived by the JPVL.



Nothing in these provisions shall constitute or be deemed to constitute any additional liability undertaking or warranty, express or implied, with respect to the Plant. All capitalized terms used, but not defined in this Warranty Limitations section shall have the respective meanings ascribed to them in the Contract.



The Contract Warranties are subject to the construction, installation and commissioning works having been performed in full compliance with the requirements stated in (a) the Contract, (b) all manuals provided by LMB, including this manual, (c) all applicable rules, regulations and laws prevailing in the location where the Plant has been installed and will operate, and (d) any other instructions, if any, provided by LMB (collectively, “Rules and Requirements”). The Contract Warranties will NOT cover any accidents, partial or total failure of the Plant, losses or damages to personnel or property (including, without limitation, the Plant’s components, parts, systems and other equipment), or any other liability (collectively, “Accidents and Damages”) in the case of any breach of the stated Rules and Requirements.



For the detailed terms and conditions of the warranty concerning the Works and Project, refer to the Contract.

MM-M02 Rev.000 (17.07.13)



Boiler Ducts and Dampers

ix

In addition to the foregoing, the Contract Warranties will NOT cover any of the following Accidents and Damages: Accidents and Damages caused by any deviation from the Rules and Requirements;



Accidents and Damages caused by the modification or re-installation of the Plant after the original installation, or caused by operation of the Plant for a purpose other than that for which it is designed;



Accidents and Damages caused by natural disasters or accidents during transfer or related handling;



Accidents and Damages occurring after the term of the warranty has expired;



Accidents and Damages due to faulty operation or operation not in accordance with the Rules and Requirements;



Accidents and Damages due to inappropriate maintenance or servicing performed by the Customer, its personnel or any other party;



Accidents and Damages caused by any components, parts, systems or other equipment other than those delivered by LMB;



Accidents and Damages caused by unidentifiable reasons including loss of the damaged parts which is necessary to pinpoint a cause of the failure;



Accidents and Damages caused by referring to inadequate, or incorrect references, data or information provided by the Customer;



Accidents and Damages caused by rust/corrosion due to inadequate handling and/or storage by the Customer; or



Accidents and Damages due to handling, storage and/ or use of the Plant under severe conditions or in an environment that does not meet the specified design conditions.

MM-M02 Rev.000 (17.07.13)



Boiler Ducts and Dampers

x

Limitation of Liability General 

The provisions set forth in this Limitation of Liability section are in addition to all liability and warranty disclaimers and limitations set forth in BID Document No: JPVL-JNSTPP-SG-01, (the “Contract”). Nothing in this Limitation of Liability section or manual shall constitute or be deemed to constitute any additional liability undertaking or warranty, express or implied, with respect to the Plant. All capitalized terms used, but not defined in this Limitation of Liability section shall have the respective meanings ascribed to them in the Contract.



The contents of this manual are subject to change without prior notice and without any obligation or liability to LMB.

Use and Disposal 

Use of the Plant must be limited to the use specified by LMB, including without limitation, use of the Plant in accordance with the Contract, this manual, all Safety Manuals, all applicable laws and regulations, and any other instructions, if any, provided by LMB. The Plant components, parts, systems and other equipment (collectively, “Equipment”) must be appropriately disposed off in accordance with the Contract, this manual, all Safety Manuals, all applicable laws and regulations, and any other instructions, if any, provided by LMB.

For Documents and Safety Training

MM-M02 Rev.000 (17.07.13)



The Customer’s personnel must read, understand and abide by all documents provided by LMB, including without limitation, the operation and maintenance manuals, safety manuals, and instruction manuals (collectively, “Safety Manuals”) and must have received all required and/or necessary safety training prior to the start of their work. Persons who have not received such safety training are not permitted to work on the installed Plant. This initial training, however, is merely the minimum requirements prior to allowing any personnel to work on the installed Plant. The Customer must, on a continual and regular schedule, give up-to-date training to its personnel on safety requirements, provide testing or other methods to confirm their understanding of the safety training, and confirm that they have the physical and mental capability to perform their respective roles. The Customer’s obligation for safety training and personnel supervision is an ongoing obligation and must be continuously performed and kept current throughout the operation of the Plant. Accidents, partial or total failure of the Plant, damage to personnel or property, loss, injuries, and other liability (collectively, “Liability”) caused by inadequate safety training or the Customer’s personnel’s failure to abide by the documents provided by LMB are expressly excluded from the coverage of any warranty provided by LMB and are the sole and exclusive responsibility of the Customer.

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xi



LMB will NOT be liable for any Liability caused by modification or changes made in Plant-related documents (including any Safety Manual) by anyone other than LMB.

For Damage to the Plant Accidents may occur by use of Equipment that is acquired from anyone other than LMB or anyone not appointed by LMB to modify or repair this Plant. The Customer shall not be permitted to modify or repair the Plant or change Equipment of the Plant without LMB’s prior written approval, under any circumstance.



LMB will NOT be liable for any Liability resulting from any abuse, misuse, misapplication of the Equipment supplied by LMB.



LMB will NOT be liable for any Liability caused by an act by the Customer in violation of the Contract, this manual, any applicable law or regulation, or any Safety Manual or any other instruction provided by LMB, including without limitation, a change of the installation environment or the removal and installation of any Equipment in a location different to that originally selected by LMB.



LMB will NOT be liable for any Liability caused by a defect, imperfection, or fault, in material or Equipment that was used during a repair, even when such a repair was performed by or under an instruction given by LMB.

MM-M02 Rev.000 (17.07.13)



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xii

Important Information Purpose of the Plant Usage This plant is designed to generate electric power of 2X660 MW by the steam turbine generator. The plant is only used for electric power generation purpose that supports stable and reliable electric power supply to power grid and supplying steam for auxiliary equipment in the power station.

General 1.

To satisfy the purpose mentioned above the following points must be strictly observed, a)

The operation, maintenance and inspection of the Boiler Ducts and Dampers must be performed by the persons who have basic technical knowledge and have been trained concerning the hazards of the Boiler Ducts and Dampers and its avoidance.

b)

The operators and maintainers must read and understand these manuals before starting the operation, maintenance or inspection. It is often experienced that serious damages to the equipment or personnel have occurred due to the unexpected action of operators or maintainers who do not fully understand the equipment.

MM-M02 Rev.000 (17.07.13)

c)

The modification or change of operational specification must be performed under the supervision of L&T-MHI Boilers Pvt.Ltd (LMB) or as per the written acceptances of LMB.

2.

The operation and maintenance must be performed according to the applicable laws and regulations at the location of the power station.

3.

Disposal from the power station must be treated to satisfy the local regulations.

4.

The copyright of software, drawings and other documents provided by LMB at all times, is still reserved by LMB.

5.

Use or copying of the whole or part of any information provided by LMB for any purpose other than operation and maintenance of this plant without written consent is strictly prohibited.

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xiii

Important General Notice for Safety 1.

The operator and maintainer must have knowledge about the equipment to maintain it in good operating condition and to avoid danger when using the equipment and systems.

2.

The protection measures must satisfy all of the operational functions.

3.

The safety activity must be planned systematically as “Safety and Health management system” and applied continually. Safety and Health management system must include the following points, a) Instructions for use and maintenance of the personal protective equipment issued to operators and maintainers b) The establishment of a work management system to make clear the operation directives and work procedures c) Implementation of training for operator and maintainer

4.

Operators and maintainers should be trained to act in a positive manner and prevent the occurrence of an accident by using their knowledge of the power plant.

5.

Operators and maintainers should be made to understand that the most important purpose of safety control is to protect all personnel from accidents and also to maintain operation of the plant without troubles.

6.

To prevent accidents involving personnel and equipment, it is necessary to observe the notices of this manual and to keep the correct operation according to the description provided in this manual. If the notices are not observed, the following dangers could occur to the operator, and to the maintainer.

MM-M02 Rev.000 (17.07.13)

7.

a)

Risk of a fatal accident

b)

Danger to lose his health and fitness

c)

Danger of damage to the equipment

LMB can not forecast all possible dangers existing in the plant such as danger due to human error and/or dangers caused by operating environment. As this manual and the alert label cannot cover all of the dangers, the operators and maintainers have to pay their full attention to all general safety notices.

8.

LMB shall not be responsible for damages and injury caused by neglecting the notices in this manual, and other necessary general notices.

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xiv

Instruction of this Manual This manual is provided for people familiar with the use of English. If some person not familiar with English is going to operate the plant, the Customer must then train him specially.

2.

This manual contains optional matters.

3.

Some figures in this manual include internal parts of the equipment which may not be obvious, when looking at the completed equipment drawing.

4.

LMB may change the content of this manual without notice.

5.

This manual is intended for the use by the operators and maintainers and it must be accessible to them at all times.

6.

If the Customer needs more detailed information, please contact LMB.

7.

The maintenance procedure described in this manual is based on engineering and design drawings/documents of the project. Maintainers should be made aware of any change in the maintenance procedure that may become necessary as a result of any modification in the equipment/installation during plant construction, commissioning or later.

8.

All data given in this manual are extracted from engineering drawings, documents and manufacturers’ instruction books for the equipment of this project. In case of any conflict or doubt regarding any value e.g. specification, dimension, torque, clearance, tolerance etc., maintainers must consult the certified and latest/as built drawings and manufacturers’ instruction books for the project.

MM-M02 Rev.000 (17.07.13)

1.

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xv

A rra n g em e n t o f th e S yste m Maintenance Manual This manual is arranged as follows. Chapter 1 Describes health and safety issues during maintenance, disassembly and reassembly of the Boiler Ducts and Dampers.

Chapter 2 Describes the construction, purpose, and function of the Boiler Ducts and Dampers and the associated parts.

Chapter 3 Describes the Boiler Ducts and Dampers parts, using the relevant Data Sheets.

Chapter 4 Describes the Preventive, Routine, and Outage Maintenance.

Chapter 5 Describes the disassembly and reassembly procedures, necessary to obtain access to internal parts for inspection and repair during Boiler Ducts and Dampers overhaul.

Chapter 6 Describes the corrective maintenance procedures to be followed to investigate,

MM-M02 Rev.000 (17.07.13)

identify and remedy defects occurring during operation.

Chapter 7

Includes Torque Chart, Spare Parts, Special Tools and Vendor Drawings/Documents

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xvi

Chapter 1

Safety

Chapter

1 S af ety 1.1

Features of Boiler Safety The boiler generates steam at high pressure and high temperature by means of combustion of coal and LDO/HFO in it’s furnace. The boiler when in operation undergoes wide variations of furnace pressure, as well as possible extremes of an explosion or implosion. To avoid such explosion or implosion, all equipment provided with the fuel firing system must be operated in a correct manner. This involves combustion of the fuel in proper condition and making sure that the burners and associated equipment are also in perfect working condition to serve the main boiler. As the boiler is operated with steam at super-critical pressure and at superheated temperature, the pressure parts of the boiler and steam pipes have to endure high stress during operation. The boiler is also a large structure and it is not possible to ascertain equal temperature distribution in all parts of the boiler. Thus the boiler has to withstand high static and dynamic stresses. This may result in the risk of tube failure. Leaked water and/or steam from the crack may also damage other parts of the boiler and/or person working near the steam blowing area. Burning of coal in the boiler produces huge quantities of ash. The ash can corrode the boiler tubes located in the gas path of the boiler and cause tube failure under high stress condition. As the steam leaked from cracks cannot be seen, all persons in the boiler area must pay attention to any noise caused by steam leakage. Some of the ash while its form to clinkers, may stick and melt on the furnace walls. Clinkers often drop onto the furnace bottom during outage of the boiler and this may lead to a hazard to personnel working in the furnace area.

MM-M02 Rev.000 (17.07.13)

As the boiler is a tall structure, personnel may be exposed to risk of falling or tripping from high elevations, while lifting parts or materials during operation and maintenance work on the boiler. All operators and maintainers must realize the danger and keep themselves safe, following the instructions written in this chapter.

Boiler Ducts and Dampers

1-1

Chapter 1

1.2

Safety

Description of Warnings Safety of personnel working in the power plant is of utmost importance. Keeping this in view, all conceivable situations are taken into consideration in the design of the power plant to avoid potential dangerous conditions. However, it is not possible to eliminate every risk because of the very nature of the plant. This manual classifies the severity and hazard level of such risks into two categories, “DANGER” and “CAUTIONS”. Read and understand the indications thoroughly before operation or maintenance of the plant. The contents of wordings, “DANGER” and “CAUTION” are described as follows; Kinds

Meaning of Warnings “DANGER” indicates an imminently hazardous situation in handling of the Boiler Ducts and Dampers, and that if not heeded, could result in death or serious injury, or serious damage to the property or environment. “CAUTION” indicates a potentially hazardous situation

CAUTION

during use of the Boiler Ducts and Dampers, which, if not avoided, may result in minor injury, or minor damage to the property or environment.

This manual also uses the following indicators in addition to the hazard level indications described above.

Kinds

Meaning of Warnings “IMPORTANT” describes the particular information or items that personnel must know during operation and

IMPORTANT

maintenance of the Boiler Ducts and Dampers, and that, if not heeded, may result in an accident of an in-assessable hazard level. “NOTICE” describes useful information and tips for handling of the Boiler Ducts and Dampers.

MM-M02 Rev.000 (17.07.13)

Notice

Boiler Ducts and Dampers

1-2

Chapter 1

Safety

1.2.1 Definitions of “serious injury”, “minor injury”, “serious damage to property”, and “minor damage to property” “Serious Injury” This term describes injuries, which leave after effects such as loss of eye sight, permanent disability, bone fracture or breakage, toxemia, gas inhalation, asphyxiation, electric shock, hospitalization or prolonged hospital visits for treatment.

“Minor Injury” This term describes injuries, which do not require hospitalization or prolonged attention at a hospital (injuries other than “the serious injuries” described above).

“Serious Damage to Property” This term describes damage, which require a suspension of productive activity for one day or more due to restoration of the damaged property.

“Minor Damage to Property”

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This term describes damage, which does not require any suspension of productive activity due to restoration of the damaged property.

Boiler Ducts and Dampers

1-3

Chapter 1

Safety

1.2.2 Symbols In this manual, the following symbols are added for easy understanding of the contents of warnings and are found next to “DANGER”, “CAUTION” and indications. These symbols are in compliance with “ISO 3864”.

Symbol

Description This symbol indicates the possible presence of high voltage, and warns of a hazard which may result in system shock, burn or death by electric shock if safety precautions are neglected or the system is handled incorrectly. This symbol indicates a movable section that is inside a safety cover or is exposed. Movable parts may inflict laceration or bone fracture to body parts such as hand, by pinching the hand and/or clothing. This symbol indicates the presence of parts whose surface could be hot, and may cause a burn if handled incorrectly.

This symbol indicates that care should be taken where you place your feet when moving around the area. Risk of injury by tripping is present near this symbol due to factors such as a location with an unstable surface, or obstructions such as scaffolding, temporary pipe lines, or other protrusions. This symbol indicates the possible presence of gas(es) which are harmful or asphyxiant to personnel. Be sure to ventilate fully before commencement of work.

This symbol indicates caution against the handling of a heavy object or working in an abnormal position. Do not work in an abnormal posture which may damage your back or waist. This symbol indicates “prohibited” items or actions during the

MM-M02 Rev.000 (17.07.13)

operation and maintenance of the Boiler Ducts and Dampers.

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1-4

Chapter 1

1.2.2

Safety

Symbols (Cont’d. from previous page..)

Symbol

Description This symbol indicates that personnel must not touch the surface since it is hot. Do NOT enter any area where this symbol is displayed.

This symbol indicates that the entry of personnel is prohibited. Do NOT enter any area where this symbol is displayed.

This symbol indicates that physical contact is prohibited. Do NOT touch or enter a location or enclosure where this symbol is displayed.

This symbol indicates that the stated items or actions in the warning notices relative to operation and maintenance of the Boiler Ducts and Dampers are mandatory.

1.2.3 Hazard Warning Label Hazard warning labels are applied where potential hazards are present during operation and maintenance activities. Hazard warning labels will be in appropriate sizes and colors that will catch the eye and the attention of personnel. They also have symbols that show the hazard types, in addition to the descriptions of warning contents.

IMPORTANT Personnel are requested to confirm the location of, and to read, and MM-M02 Rev.000 (17.07.13)

thoroughly understand the contents of all hazard warning labels applied to this Boiler Ducts and Dampers. If any of the hazard warning labels peel off/wear out or become unreadable, install a new label in the original location without delay.

Boiler Ducts and Dampers

1-5

Chapter 1

Safety

WARNING

DO NOT COME NEAR TO SHAFT EXPOSED ZONE WHEN IN OPERATION

STEEP DROP

DO NOT ENTER

DO NOT TOUCH

DO NOT TOUCH

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T B0001_A

FIGURE 1-1

Boiler Ducts and Dampers

TYPES OF HAZARD WARNING LABEL

1-6

Chapter 1

Safety

1.2.4 Hazard Area

IMPORTANT Only trained maintainers are allowed to enter the maintenance work area. Entry of untrained personnel to the area could cause not only

MM-M02 Rev.000 (17.07.13)

injury but also serious damage to the Boiler Ducts and Dampers.

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1-7

Chapter 1

1.3

Safety

Risk Assessment Standard (As per MIL STD882D) TABLE 1-1

RISK ASSESSMENT STANDARD Detailed Description of Impact on each Object

Category

Safety

Environment

I

Catastrophic

- Unit shutdown (unit cannot be operated) - More than 4 days for repairing

- Death

-Harmful gas or oil leakage -High pressure and temperature material leakage such as steam, water, air and gas, oil etc -Low oxygen

II

Critical

- Unit shutdown (cannot be operated) - Within 3 days for repairing

- Serious Injury

- Same as above

III

Marginal

- Unit shutdown (cannot be operated) - Can be repaired by Customer

- Minor Injury (with hospitalization)

IV

Negligible

- Same as above -High temperature surface -High elevation or unstable - Not harmful and high pressure & temperature leakage -Mechanically protected

- Minor Injury (without hospitalization)

TABLE 1-1

RISK ASSESSMENT STANDARD (CONTINUED)

Definition

Description

Category

Detailed

(A)

Frequent

Repeating occurrence

1 time / 1 or 2 months

(B)

Probable

Known to occur, or, “it has happened”

1 time / 1 year

(C)

Occasional

Could occur

1 time / 5 years

(D)

Remote

Not likely to occur

1 time / 10 years

(E)

Improbable

Practically Impossible

1 or 2 times / total life

TABLE 1-1 Hazard Categories Frequency of Occurrence

MM-M02 Rev.000 (17.07.13)

Health

RISK ASSESSMENT STANDARD (CONTINUED) I

II

III

IV

Catastrophic

Critical

Marginal

Negligible

(A)

Frequent

1

3

7

13

(B)

Probable

2

5

9

16

(C)

Occasional

4

6

11

18

(D)

Remote

8

10

14

19

(E)

Improbable

12

15

17

20

LEGEND

High

Boiler Ducts and Dampers

Serious

Medium

Low

1-8

Chapter 1

Safety

DANGER ZONE (Contains High temperature water, air and gas) WORKING ZONE

MM-M02 Rev.000 (17.07.13)

(Floor)

FIGURE 1-2 Boiler Ducts and Dampers

DANGER ZONE IN BOILER AREA 1-9

Chapter 1

1.4

Safety

Safety Measures 1.4.1 Work Permit System (Lockout/Tagout)

MM-M02 Rev.000 (17.07.13)

Work Permit System is applied when the Boiler Ducts and Dampers are shutdown for maintenance work, to complete the maintenance work under safe conditions. Customer is to develop a comprehensive work permit system. However, the recommended outline of the work permit system is as follows: 1

The Maintenance Engineer fills an application form for the work permit clearly indicating the content of the maintenance work that he wants to do, and submits it to the Shift Charge Engineer.

2

The Shift Charge Engineer passes the work permit form to the operator to study and decides the isolation method from the line in operation based on the mechanical and electrical view point. He then reports it to the Shift Charge Engineer with the comments on the hazard conditions for the work.

3

The Shift Charge Engineer gives work permit number and prepares necessary tags to show the work permit number and the situation of isolation of equipments/system/line. He then instructs the operators to set the isolation condition following the work permit form.

4

The operators open the breaker and set the valves to the specified condition, and the breaker and the valves are locked. The operators return the work permit to the Shift Charge Engineer.

5

The Shift Charge Engineer checks the isolation and issues the signed work permit to the Maintenance Engineer, or his representative.

6

The Maintenance Engineer orders the start of the maintenance work to the personnel nominated.

7

The Maintenance Engineer or his representative then returns the signed work permit to the Shift Charge Engineer after making sure the maintenance work is completed.

8

The Shift Charge Engineer then sends operators to release the locks and return them to the original situation.

9

The operators check the situation and report that the system is now back to the normal condition when signing off the work permit.

10

The Shift Charge Engineer makes sure that the work under the permit is completed and files details in the log book.

The Work Permit System outlines the responsibility of the workers at each step and ensures that the work is performed safely. Boiler Ducts and Dampers

1-10

Chapter 1

1.4.2

Safety

General Cautions on Personnel in Working Area

1.4.2.1

Caution against Rotating Equipment All couplings on rotating machines are covered by the coupling cover. However, whole parts of the shaft are not fully covered. It is recommended that the following warnings are observed strictly.



Do not approach or operate the equipment where protective covers have been removed. Get additional supervisor assistance.



Make sure that the circuit breaker for the motor is opened when required to remove the cover.



Care must be taken for exposed rotating parts, especially the place between the casing and coupling.



All shafting, coupling and other rotating parts must be guarded in order to prevent accidental contact.

1.4.2.2

Cautions against Electrical Equipment

MM-M02 Rev.000 (17.07.13)

The electrical equipment covered under this section includes all the plant equipment and the maintenance tools like grinders, lamps, welding equipment etc. Though live parts of the plant or maintenance tools are insulated, be sure to observe the following precautions. Failure to observe them may cause fatal accidents or personal injuries and damage to the electrical equipment.



Always make sure that power supply is switched off and disconnected at the up-stream side of power supply line for any kind of work on electric system and it is locked according to the Work Permit.



Under all circumstances , inspect live parts before bringing them into contact.



Do not remove or open panels or doors labeled with high live part warning label not included in the Work Permit.



Make sure that no material and/or parts remain in the panels or terminal box before closing them finally.

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1-11

Chapter 1

1.4.2.3

Safety

Cautions against High Temperature Sections Many equipment and pipelines in the plant contain high temperature fluid and they are insulated on their surface. Even though several hot spots exist in the wide area of insulated surface, some specified equipments and pipe lines are not insulated for cooling purpose. Since the temperature is very high and you can get burnt, observe the following caution to avoid burn injury.

CAUTION Wear suitable working wear including gloves to avoid direct contact with hot spots in the plant.



Sampling piping is not insulated to cool down the steam to a suitable temperature for the analyzer except in the places located close to a pass-way for personnel.



All exhaust pipes of the safety valves and the exhaust pipe of the boiler flush pipe are not insulated. Always wear gloves.



Do not touch measuring ports when boiler is operating without using aspirating line, Unexpected blow may occur. Because pressure of inside the duct is positive. Aspirating line must be checked by confirming sounds which show the aspirating air is working.

MM-M02 Rev.000 (17.07.13)



Boiler Ducts and Dampers

1-12

Chapter 1

1.4.2.4

Safety

Cautions against Steam Leakage in the Plant The steam leakage especially from high temperature steam may cause serious injury to the personnel and it must be repaired at an early stage of the leakage. Following pre-cautions must be followed to find leakage at an early stage.



Water drips may occur at the insulated parts such as the connected parts of lagging. The leaking point can be found by partially removing insulation with utmost care.



At the next step, the leakage water changes to visible steam. It is now too dangerous to remove the insulation.



Leakage of the superheated steam only makes whistling noise without generating white steam. It is very dangerous to approach the noise area.



Obtain a Permit to work before repairing the damage.



Be aware of the steam. The steam could leak from the water system which could contain water at 100ºC or higher even if it is low pressure type water system.



High temperature drain or steam could leak from the flush pipe during start-up.

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If not avoided, the steam or vapour can enter inside your working wear through a small gap between the body and clothing.

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1-13

Chapter 1

1.4.2.5

Safety

Cautions against Oil Leak in the Plant

CAUTION 

Oil leakage is very dangerous. It is a potential fire hazard.



Any oil leakage must be reported to the Shift Charge Engineer.



Oil leaks makes the area slippery and people are advised to move around these areas carefully.

1.4.2.6

Cautions against Chemicals Pay attention to the items to prevent any accident related to the chemicals in the plant.

IMPORTANT Precaution against chemicals



Operate chemical injection systems by strictly following the instructions of the chemist. The operator must use suitable protective tools.

Disposal



Observe the rules and regulation of the installation site.

Material Safety Data Sheet (hereafter MSDS)



Always understand the content of applicable MSDS in advance, and observe the notified instructions when handling.

Emergency response Solution against emergency must be thoroughly instructed to all personnel involved so that the complete measures can be taken in emergency.

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

Boiler Ducts and Dampers

1-14

Chapter 1

1.4.2.7

Safety

Cautions against Combustible Materials/ Storage Areas

IMPORTANT 

Storage containers must be clearly marked to indicate the content.



Bunding must be provided for bulk tanks.



Suitable fire protection must be provided for each area.



Do not store bulk combustible materials on the site.



Small quantities of combustible material must be stored in fire resistant cupboards.



Combustible materials must be segregated from other equipment.



Leakage of gasoline has risk of fire. Maximum storage quantity of gasoline outside of the dispensing pump is five (5) liters.

Emergency response:



Personnel directly involved in handling of combustible materials MUST be properly trained and thoroughly instructed. Other personnel in the vicinity must be aware of the dangers and take precautions in all situations.

MM-M02 Rev.000 (17.07.13)

1.4.2.8

Cautions against Lack of Oxygen



Check the oxygen content in the equipment, vessel, in a confined space before entering, to ensure sufficient ventilation.



Continue monitoring inspection.



Do not enter the equipment, vessel or confined space alone. If you must enter alone, take the necessary preventive measure to find a partner who will wait for your return at the point of entry.



Make complete arrangement for rescue.

Boiler Ducts and Dampers

oxygen

and

ventilation

during

1-15

Chapter 1

1.4.2.9

Safety

Cautions against Lifting Heavy Object Be careful during the removal/installation of any equipment during maintenance.

CAUTION 

Do NOT attempt to move or lift equipment in an abnormal posture. ALWAYS install/remove equipment, using a forklift or a crane. A normal lift without mechanical aid should be undertaken by two or more people.



Failure to observe the above may cause injury due to dropped equipment, back or waist injury or damage to the equipment.

1.4.2.10

Caution against Sharp Objects

CAUTION 

Use leather gloves when handling parts with sharp edges.

1.4.2.11

Cautions for using a Fork Lift Truck

CAUTION Do NOT permit anyone to stand below any item being lifted under any circumstance.



Failure to observe this may cause fatal accidents.



When using a forklift, ALWAYS lift the objects parallel to the ground while considering the center of gravity.Otherwise, lifted objects may fall and serious damage could occur.



A forklift is often used to transfer small machines. Check fork insertion position for the forklift prior to use. Be careful, as marks which indicate the fork insertion positions are sometimes hidden by wraps or packing material.

MM-M02 Rev.000 (17.07.13)



Boiler Ducts and Dampers

1-16

Chapter 1

1.4.2.12

Safety

Cautions using Crane

CAUTION A crane is often used to transfer heavy parts. Check for any possible risks which could occur during hoisting and transportation before operating the crane. Checking of the equipment:



Check the crane, the crane hook and all related items before use. Use wire ropes which can withstand the weight of the parts multiplied by a safety factor.



Inspect the shackles, eyebolts, jigs and wire ropes provided for the hoisting work prior to the actual hoisting.



Perform periodical inspection of hoisting tools at least once a year.

Rigging/ Slinging work:



Only authorized personnel can perform slinging work and operation of the crane.

Work area:



Before hoisting, secure a working area around the part to be lifted and prohibit the entry of unrelated personnel.

Hoisting method:



Hoist the part parallel to the ground while paying attention to the center of gravity.



Do NOT permit any person to stand under the part being lifted.



Pay attention and ensure that all persons are clear of the equipment being lifted.

Hoisting point:



Do NOT hoist any part from a position other than the specified hoisting points.

Unpacking:

MM-M02 Rev.000 (17.07.13)



Do NOT unpack any part until it is located in the designated location.

Protection of machine:



Boiler Ducts and Dampers

Avoid any impact with the unpacked parts.

1-17

Chapter 1

1.4.2.13 a)

Safety

Disposal Water disposal including oily drain The water is disposed through the plant drain system. The water must be carefully disposed according to materials contained in the water. The water drain system is separated into 3 categories; that are rain water, chemical water and oily water system. The waste water shall be treated and discharged to the public drain system.

b)

Chemical disposal Chemicals must be handled following the instruction of MSDS and disposed to the chemical drain system.

c)

Solid disposal made by maintenance work.

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For disposal from the site, observe the local legal regulations.

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Chapter 1

1.5

Safety

Emergency Measures 1.5.1 Evacuation in an Emergency 1.5.1.1

Evacuation Route The following items are considered on the design and installation of an emergency evacuation.

IMPORTANT  Each building in the plant is provided with 2 exits or more.

 Clear indication of exit that can be seen from any place in the building is provided with emergency power supply.

 Evacuation routes are indicated on each floor of the building, which leads personnel to the exits.

 Keep the evacuation routes completely free from materials and tools.

1.5.1.2

Evacuation of Disabled Persons The following items shall be considered for evacuation of disabled persons during an emergency:

IMPORTANT It is recommended to keep a stretcher available for emergencies at a place that is clearly visible.

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Chapter 1

1.5.1.3

Safety

Evacuation from the Power House Following are the guidances for evacuation from the power house.

IMPORTANT An Assembly place for personnel to assemble at after evacuation from the power house in an emergency must be predetermined and explained beforehand in the emergency training.



Evacuation directive must be given by the authorized person such as Shift Charge Engineer, and all personnel must be alerted in the power house repeatedly with an available communication facility.



All people working in the power house must stop the work immediately and leave the power house to the Assembly place.



When evacuated to the Assembly place, make sure that there is no one missing.

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

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Chapter 1

Safety

1.5.2 Fire Accident

IMPORTANT Clearly show the location of fire alarm push button and fire extinguisher to make everybody take the first step at fire protection.



Inform everyone concerned that a fire has broken out, if you happen to spot one.



Start fire-fighting using the fire extinguisher located near the fire site.



The operators must check whether the plant is ready for trip, and wait for orders from the authorized person.



The operator and other personnel must hand over the task of fire-fighting to the fire-fighting team when they arrive at the fire site and the operators must wait for instructions from the Shift Charge Engineer. All other personnel must immediately start evacuation.



If unit trip is decided, the operator must trip the plant manually.



The operators must evacuate the power house according to the instructions of the authorized person, immediately after shutdown of the unit.



If the fire is extinguished successfully, the operators should return to the power house as required by the Shift Charge Engineer and start inspection of the equipment for restarting the unit.



Based on the inspection, the authorized person should decide whether to operate the unit again or go for a shutdown for repair work.



After the inspection or repair, and then checking the equipment and/or system, start up the unit again.

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

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Chapter 1

Safety

1.5.3 Earthquake In case of an earthquake, the shift charge engineer or operator must judge whether the unit trip is necessary according to the intensity of the earthquake, and immediately trip the unit manually. If the unit is tripped, all equipment must be carefully checked on its operation status and tripped if abnormal phenomena are found. In the local area, mechanical and/or thermal shocks may be given to the equipment, piping, instruments and electrical panels. Be sure to observe the following when inspecting as above.



Check whether the lubricating oil pump is running. Bearings of the equipment will be damaged if lubricating oil is not supplied.



Check the piping and equipment for steam and water leakage. The steam or high temperature water leakage may cause serious injury to the personnel and it must be repaired at an early stage of the leakage.



Check the pulverizers and/or coal silos for signs of a fire. If a fire does start, make sure that the CO2 fire fighting system is properly operated.



Check the position of the boiler seismic stopper. Since the boiler seismic stopper must be anchored at the original position, boiler cannot be re-started if slippage is found. If the stopper is not at the original position, please contact LMB.

CAUTION 

Check the piping and equipment for the breaking or dropping of insulation. Since the exposure to hot surface may cause burn injury, it must be repaired if found.

MM-M02 Rev.000 (17.07.13)

1.5.4 Explosion Accident



Boiler Ducts and Dampers

Do not light a fire in a hazardous area where the combustibles (hydrogen gas, oxygen gas, coal, fuel oil, etc.) are stored or handled. Lighting a fire in a hazardous area can cause serious injury to personnel and serious damage to equipment due to explosion. 1-22

Chapter 1

1.6

Safety

Qualification and Training The system must be operated only by authorized operators & maintenance supervisors. Minimum requirements an operator and maintainer must satisfy : Operator and Maintainer can read and fully understand the description of this manual.



Operator and Maintainer can understand the related P & ID, logic diagram.



Operator and Maintainer know the location of the system equipment including pipe routes, valves and instruments.



Operator and Maintainer have fundamental knowledge of the function of each part of the equipment.



Operator can operate the equipment and the system manually at local stations.



Operator can operate the system remotely using BMS and DCS .



Operator can respond suitably to any kind of alarm.



Operator knows location of emergency exit in power house and is available to provide first aid treatment.



Operator knows emergency communication system operation.



Operator and Maintainer, following the Shift Charge Engineer’s instruction are aware of the isolation method for mechanical, electrical and instrumental equipments for safe maintenance work while the unit is in operation.



Maintainer must also be able to handle the maintenance tools provided by the owner and those supplied by the manufacturer.

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Chapter 2 General

Chapter

2 G e n eral 2.1

Purpose The purpose of this maintenance manual is to provide specific information to the Jaypee Nigrie Super Thermal Power Project mechanical maintenance personnel regarding the maintenance of Boiler Ducts and Dampers. Although this document will convey a good knowledge and direction regarding maintenance of the ducts, dampers and the associated components, it is recommended that in the event of a problem, not covered in this document, the person responsible should seek assistance or instruction from the manufacturer.

References a)

Air and Flue Gas P & I Diagram LMB Dwg. No. 97000-2161-1

b)

Boiler Cooling Air and Seal Air P & I Diagram LMB Dwg. No. 97000-2161-2

c)

Arrangement of Air Duct LMB Dwg No. : 38200- 0213.

d)

Detail of Air Duct (RAPH~BWB) LMB Dwg No. : 38100- 0211

e)

Arrangement of Gas Duct (1/4 to 4/4) LMB Dwg No. : 38400- 0001-0004

f)

Design of Multi-Louver Damper for Air and Gas Ducts LMB Dwg No. : 38000-3003-R.

g)

Design of Non-Metallic Expansion Joint for Air Duct LMB Dwg No. : 38000-2002 & 2012

h)

Typical Arrangement of Hanger Supports LMB Dwg No. : 38200-1021 & 1026

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2.2

Boiler Ducts and Dampers

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Chapter 2 General

2.3

Overview of the Boiler Ducts and Dampers In Jaypee Nigrie Super Thermal Power Project, pulverized coal is used in the boiler as the main fuel, and light diesel oil (LDO) is used as the initial start-up fuel. In addition, heavy fuel oil (HFO) is fired after initial Unit startup with LDO and also for stabilization of coal firing at low loads. Eight tilting type burner assemblies are provided on the eight sides of the furnace of each boiler for efficient and stable combustion of the fuel. Each burner assembly has provisions to fire pulverized coal at six elevations and oil at three elevations. The burners, arranged to form a corner firing system, produce two fireballs inside the furnace. Combustion air to these burners is provided through control dampers secured to eight wind boxes located on each corner of the furnace. Refer to Figure 2-1. The Air and Flue Gas System supplies combustion air to the pulverized coal in the furnace and evacuates the products of combustion from the furnace. The Air and Flue Gas System consists of two forced draft (FD) fans, two primary air (PA) fans, two induced draft (ID) fans, two regenerative airheaters (RAPH), electrostatic precipitators (EP) and associated ducts and dampers. The FD fans supply secondary air for the combustion of the pulverized coal. The PA fans supply primary air for drying and transporting the pulverized coal to the furnace. The ID fans evacuate the products of combustion from the furnace and exhaust it to the atmosphere through the stack. Cooling air for the flame detector is provided by two flame detector cooling air fans (one AC driven and another DC driven). These fans supply cooling air and protect the flame detectors from hot gases during operation. Cooling and sealing air for the furnace TV camera is directly supplied from the instrument air header for protection of the furnace TV camera from hot gases during operation. Sealing air required by the pulverized fuel system and the dampers handling ash-laden air is provided by two pulverizer seal air fans.

Boiler Ducts Refer to Figures 2-1 to 2-3.

MM-M02 Rev.000 (17.07.13)

The air and flue gas ducts are designed to carry air and flue gas without any external leakage and with minimum pressure drop. The primary air and secondary air are carried through air ducts; and the flue gas is carried through gas ducts. The air ducts connect the FD fans to the furnace via the RAPHs. The cold air ducts (bypassing the RAPH) and the hot air ducts (passing through RAPH) connect the PA fans to the pulverizers. The flue gas ducts connect the furnace to the atmosphere via the RAPHs, EPs and ID fans. The flue gas system is designed to provide passage for the products of combustion from the boiler. After leaving the economizer in two streams, the flue gas passes through the RAPHs and EPs. The suspended particulates are separated in the EPs and the resultant flue gas passes through the ID fans. The Boiler Ducts and Dampers

2-2

Chapter 2 General

two flue gas circuits are then directed to a common duct and the gas is discharged to the atmosphere through a stack. The stack discharges the products of combustion at a high elevation thereby reducing ground pollution from the plant. NOx, O2, SO2 and particulate measuring instruments are installed in the stack to assist in the control of emission level within permissible limits. The air and flue gas ducts are provided with non-metallic expansion joints at appropriate locations. These expansion joints absorb the thermal expansion in the hot air ducts and in the flue gas ducts during hot condition. They also absorb transmission of expansion and vibration forces to the equipment from the connected ducts. The external surfaces of the hot ducts are provided with thermal insulation to reduce heat loss and to prevent burn injuries to the operating personnel. The air and flue gas ducts are provided with a combination of fixed and movable supports to allow thermal expansion in the desired direction.

Dampers Refer to Figures 2-1 to 2-3. Dampers are installed in the ducts at specific locations to allow isolation of equipment for maintenance without affecting the operation of the boiler. Dampers are also provided to control air and flue gas flows as per requirement. The FD, and PA fans are provided with multi-louver type ON-OFF dampers at their discharge sides; ID fans are provided with duplex multi-louver type ON-OFF dampers at their suction and discharge sides. These discharge dampers are meant for starting the fans on no load and also for isolating any fan for maintenance purposes.

MM-M02 Rev.000 (17.07.13)

The RAPHs are provided with multi-louver type ON-OFF dampers at the outlet of primary air and secondary air. Multi-louver type ON-OFF dampers are also provided at the outlet of RAPH flue gas ducts. Duplex multi-louver dampers are provided at the inlet of RAPH flue gas ducts. Each EP has three flue gas passes , which are further divided into two passes (i.e. six in total). The EPs are provided with glandular spade guillotine type isolation dampers at the inlet and outlet of each of the subdivided flue gas passes. A total of twenty four (24) such dampers are provided for the gas passes, twelve (12) for the inlet and twelve (12) for the outlet. The flue gas duct at the downstream of economizer is provided with control multi-Louver type dampers to adjust flue gas flow as per requirement. The wind-boxes are also provided with control multi-louver type dampers to control combustion airflow according to fuel flow and load. Butterfly dampers are provided at the suction side of the flame detector cooling air fans (AC & DC). Butterfly dampers are also provided at the suction and discharge sides of each pulverizer seal air fan for isolation. Boiler Ducts and Dampers

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Chapter 2 General

Two 3-way dampers are provided, one at the common discharge duct of the flame detector cooling air fans and another at the common suction duct of the flame detector cooling air fans. The 3-way damper isolates the fan running with reduced discharge pressure.

MM-M02 Rev.000 (17.07.13)

Another two 3-way dampers are provided at the discharge ducts tapped from each of PAF and FDF outlet. This air is used for sealing the RAPH.

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2-4

General

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Chapter-2

FIGURE 2-1 Boiler Ducts and Dampers

AIR AND FLUE GAS FLOW DIAGRAM 2-5

General

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Chapter-2

FIGURE 2-2 Boiler Ducts and Dampers

BOILER COOLING AND SEALING AIR SYSTEM FLOW DIAGRAM 2-6

Chapter-2

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ITEM 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

FIGURE 2-3 Boiler Ducts and Dampers

General

DESCRIPTION ROOF HOUSING AIR HEATERS FORCED DRAFT FAN PRIMARY AIR FANS FURNACE CLINKER HOPPER COAL PULVERIZER FEEDERS COAL BUNKERS FLUE GAS DUCT COLD SECONDARY AIR DUCT HOT SECONDARY AIR DUCT COLD PRIMARY AIR DUCT HOT PRIMARY AIR DUCT FD FAN SILENCER ELECTROSTATIC PRECIPITATOR INDUCED DRAFT FAN STACK

ARRANGEMENT OF AIR AND FLUE GAS DUCTS 2-7

Chapter 2 General

2.4

Construction The major components of the air and gas ducting system are as follows:



Ducts



Stiffeners and struts



Guide vanes



Expansion joints



Duct supports



Dampers.

2.4.1 Ducts Refer to Figure 2-4. The function of the air/flue gas ducts is to transport air or flue gas to the desired location without any external leakage. The ducts are designed to perform this task with minimum pressure drop so as to minimize the system resistance as well as the capacity of the fans. The air and flue gas ducts are fabricated from carbon steel plates of the required grade based on the location of their use.. The larger size ducts are normally test-assembled at factory and sent to site in knocked-down condition for easy transportation. The smaller sized ducts are sent as a fabricated piece. The duct parts are assembled at site, welded together with flanges/ expansion bellows/dampers depending on their location in the system. After assembly, the ducts are seal welded internally to prevent leakage. The connections between ducts and expansion joints are bolted with gasket to prevent leakage. The assembled ducts are provided with appropriate supports to bear the weight of ducts and to assist in their movement due to thermal expansion.

MM-M02 Rev.000 (17.07.13)

The ducts are welded with stiffeners on the outside surfaces and struts inside to withstand extreme operating pressure conditions. Guide vanes are welded inside the ducts at certain bends to reduce pressure drop across the bend. The guide vanes reduce turbulence and achieve smooth gas flow. The ducts handling hot medium are provided with thermal insulation on the outside surfaces to prevent heat loss and injury to operating personnel.

Boiler Ducts and Dampers

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Chapter 2 General

Access doors are provided to facilitate internal inspection and maintenance of the ducts. The larger ducts are provided with internal ladders at the access door entry. Access platforms are provided for the access doors where necessary. The access doors are provided with sealing gaskets and bolted to prevent air/gas leakage through them. Instrument tapping points and test pockets are welded on the ducts at specific locations for the remote and local measurements of pressure, temperature, etc.

2.4.2 Stiffeners and Struts Refer to Figure 2-4. The function of stiffeners and struts is to provide rigidity to the duct. They protect the ducts from damage during any abnormal furnace pressure fluctuations. Stiffeners are angles or channel beams welded onto the perimeter of the ducts at pre-determined pitches. Stiffeners provide rigidity to the ducts from the outside surface. Additional rigidity for the ducts is provided internally by struts welded inside the ducts. The internal stiffeners are formed by welding gusset plates on the inside surface of the ducts and by welding struts between two gusset plates. Typical constructional details of the stiffeners and struts are shown in the attached drawing.

2.4.3 Guide Vanes Guide vanes are made up of thin steel plates fabricated to form a set of curved plates. The curved plates are made in different sizes with uniform curvature. They are welded inside the ducts between two parallel duct surfaces, normally at sharp bends. They reduce turbulence and achieve smooth fluid flow across the entire duct cross section, thereby reducing pressure drop across the bend.

2.4.4 Expansion Joints

MM-M02 Rev.000 (17.07.13)

Refer to Figures 2-5 and 2-6. The main function of the expansion joints in the ducting system is to absorb thermal expansion. They also reduce transmission of vibration from the fans to the ducts and vice-versa. Non-metallic type expansion joints are used in the ducting system depending upon their suitability, application and location.

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Chapter 2 General

Non-metallic Expansion Joint Refer to Figure 2-5 and 2-6. Non-metallic expansion joints are provided on the inlet and outlet ducts of FD, PA and ID fans. The non-metallic expansion joint is formed by bolting an expansion bellow (hardened rubber) and two cover plates between two angles. The cover plates are located within the duct facing air/flue gas, thus protecting the bellow. The cover plates are bolted to each end of the expansion joint to form an overlapping sliding joint as indicated in Figure 2-5 and 2-6. Non-asbestos packing is provided at the expansion joint flanges to ensure leak-proof. These flanges are used to secure the expansion joint sections to the ducts. The expansion joints at the discharge of the FD, PA, and ID fans are provided with an outer cover in addition to the inner cover. Dependent on their locations, these expansion joint sections are designed for a specific temperature and thermal expansion. For details of non-metallic expansion joints, refer to Table 3-5.

2.4.5 Duct Supports Refer to Figures 2-7 and 2-8. Duct supports are provided at various locations to support and guide them to move in the desired direction with minimum stress. Supports, hangers and stoppers are selectively provided on the ducts to move them as desired. The type of support and the materials used are decided with reference to the duct location and medium handled. Duct supports can be classified as supports, hangers and stoppers. Supports are further classified as fixed support, sliding support and guide support. Hangers are further classified as rigid hanger, spring hanger and constant load hanger. Stoppers are further classified as rigid stopper and guide stopper. The hangers and supports are designed to support the total weight of the duct, attachments, insulation and associated dynamic load.

MM-M02 Rev.000 (17.07.13)

Supports Refer to Figure 2-7. Supports are welded steel components, fabricated from steel plates and pipes. Fixed supports are welded both onto the structures and ducts. In the sliding and guide supports, one end is welded to the duct and the other end is connected with slide plate. The free end is provided with machined plates and liners to enable the support to Boiler Ducts and Dampers

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Chapter 2 General

move. Cleats are welded around the moving plate to direct the support in a particular plane. Supports are normally located below the point of support. Fixed support anchors the duct at the point of support. Sliding support allows the duct to move in any direction in the horizontal plane. Guide support allows the duct to move in a particular direction in the horizontal plane.

Stoppers Refer to Figure 2-7. Stoppers consist of beams welded onto both ducts and structures. The beams are interlocked with each other such that they can permit movement in certain plane(s) or restrict movement. A rigid or guide stopper controls or restricts movement of the ducts without bearing their weight. Rigid stopper restricts movement of the duct in all planes at the point of installation. Guide stopper allows movement of the duct in the desired plane(s).

Hangers Refer to Figure 2-8. Hangers consist of tie rods, spring or constant load hangers, clevis brackets and support brackets. The support brackets are welded to the ducts and the clevis bracket to the supporting structure. The duct is then supported to the structure through a combination of tie-rods, spring hangers, clevis, spherical washers and nuts. Hangers are normally supported in structures above the point of support. Rigid hanger restricts duct movement in the vertical plane at the point of support and allows movement in the other two planes. Spring hanger allows the duct to move in all three planes, but the supporting load changes as the duct moves in the vertical plane. Constant load hanger also allows the duct to move in all three planes, but the supporting load doesn’t vary appreciably as per duct movement.

2.4.6 Dampers

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Various types of dampers used in the ducting system are as follows:



Multi-Louver damper



Butterfly damper



3-way damper



Wind-box dampers.

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Chapter 2 General



Guillotine damper

a)

Multi-Louver Damper Refer to Figures 2-9 and 2-10. The multi-louver dampers are used in the ducting system either for isolation of equipment or flow control purposes. For normal applications, Multi-louver dampers are provided. Where the width of the duct is large, duplex multi-Louver dampers are used. Duplex multi-louver dampers are provided with double row of sealing system on a single blade. To provide 100% tightness in the interspace a peripheral air barrier is created by a small fan ensuring any gas leakage is positively banned. Seal air facility is provided to the stuffing boxes of dampers which handle ash-laden air (hot primary and hot secondary air). The major components of a multi-louver damper are as follows:



Damper frame



Landing bar and damper seals.



Shaft and blade assembly



Bearing assembly



Stuffing box



Lever Arm and Rod links



Actuator.

MM-M02 Rev.000 (17.07.13)

The damper frame is a fabricated structure made of minimum.6 mm thick Carbon steel plates. Flanges are welded to each end of the frame to secure the damper to the ducting. Damper seals and landing bars, made from carbon steel plates, are welded at the top and bottom ends of the frame. The top and bottom blades overlap and butt against these seats in the closed position and provide sealing with the end blades. The damper blades are fabricated from minimum 6 mm thick Carbon steel plates and are located within the damper frame. The blades are of the rotating type and are arranged horizontally one above the other. Each blade is of hollow rectangular in cross-section as indicated in Figures 2-9 to 2-10. Two end plates are welded at the bottom Boiler Ducts and Dampers

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Chapter 2 General

and top ends of each blade. The end plates overlap either with the damper seats or with the adjacent end plate and provide sealing when closed. The extreme ends of the blades are provided with bosses to accept blade shafts. The blade shafts are inserted into the blades at each end and secured by lock pins. The shafts are supported at the ends of the frame using spherical bearings. There are two types of shaft: drive shaft and stub shaft. The drive shaft is longer than the stub shaft. The stub shafts are supported at the ends by spherical bearings which are self-lubricated. Grease is periodically applied for better lubrication. The drive shaft is supported by a spherical bearing mounted on an outside bracket welded to the damper frame. Stuffing box is provided where the drive and driven shaft penetrates the frame to prevent air/flue gas leakage. The stuffing box is provided with non-asbestos gland packing and a gland follower. The gland follower is sufficiently tightened to prevent leakage and permit smooth operation. Over-tightening of the gland follower will result in sticky operation or jamming of the damper. The drive shaft is provided with a lever arm, which is connected to the damper actuator using a link pin. The drive blade is linked to other blades by means of a linkage mechanism. A link rod connects the levers provided on the driven blades using link pins. A turn buckle is provided in the link rod to enable adjustment between damper blades. The driven blade lever arm, link rod and turn buckle are located within the damper frame.

MM-M02 Rev.000 (17.07.13)

The damper is provided with a mechanical lock arrangement at the lever arm to ensure positive locking during maintenance. In the event of maintenance of pulverizer, cold and hot air inlet dampers must be closed engaging the mechanical lock in close position. And before putting the dampers into service the mechanical lock needs to be disengaged to restore into the normal operation. The lever arm and links are so arranged such that all blades move in the same direction in an isolation damper. In a control damper, the adjacent blades are linked to move in opposite directions. The pneumatic actuator for the damper is mounted on a support bracket welded on the damper frame around the drive shaft. The actuator is hinged to enable angular movement of the driving lever. The isolation dampers are provided with pneumatic power cylinders. The pneumatic control dampers are provided with control drive type. Boiler Ducts and Dampers

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Chapter 2 General

Each actuator is provided with filter regulator, solenoid valve, speed controllers, limit switches, quick exhaust valves and isolation valve. These items ensure smooth operation of damper at the required speed. Compressed air from the Instrument Air System is used to operate the damper actuators. Limit switches are provided to indicate open or closed position in the central control room. A position indicator plate is installed on the damper frame provides local indication.

b)

Butterfly Damper Refer to Figure 2-11. Butterfly dampers are provided in the inlets of flame detector cooling air fan. These dampers are of the ON-OFF type and remain either in the fully open or close position. The butterfly damper is of a multi-louver type construction. The butterfly damper consists of a frame, fabricated from Carbon steel plates. Counter flanges are welded to each end of the frame to secure the damper to the ducting. Two adjacent seats, made from Carbon steel plates, are welded at the top and bottom inside surfaces of the frame. The damper blade seals overlap and butt against these seats in the closed position and provide sealing with the end blades. The damper blade assembly, fabricated from Carbon steel plates, is located within the damper frame. Two identical damper blades are assembled together and secured to the common damper shaft. Seal plates are bolted to the edges of the damper blades as indicated in Figure 2-11. The seal plates butt against the damper seats and provide effective sealing when closed.

MM-M02 Rev.000 (17.07.13)

The blade shafts (drive and stub) are inserted between the two identical blades and locked by a set of lock pins. The shafts are supported at both ends, outside the frame, using high temperature type bearings. Stuffing boxes are provided where the shafts penetrate the frame to prevent air leakage. The stuffing boxes are provided with non-asbestos gland packing and a gland follower. The gland follower is tightened just sufficient to prevent leakage and permit smooth operation. Over tightening of the gland follower would result in sticky operation or jamming of the damper. A gear box is coupled with electric actuator and with the drive-end shaft. The electric actuator for the damper is mounted on a support bracket welded onto the damper frame around the Boiler Ducts and Dampers

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Chapter 2 General

drive-end shaft. The electric actuator is supported and hinged at the middle to enable angular movement of the driving lever. Limit switches are provided to detect open or closed position in the central control room. A position indicator plate is installed on the damper drive-end shaft to provide local indication.

c)

3-Way Damper Refer to Figure 2-12. 3-way dampers are used in locations where it is required to run only one out of the two fans available. It is installed in the suction and discharge ducts of the flame detector cooling air fans. The 3-way damper consists of a T-shaped body with two inlet and one outlet ducts. A disc, installed within the frame around a shaft, is hinged at the bottom of the body along the vertical axis. The disc moves to either of the extreme positions with respect to the hinge. The drive shaft is supported at the ends of the damper frame on double row deep groove bearings. O-rings are provided at both ends to prevent leakage of air. Flanges are welded to the inlets and outlet connections of the frame to facilitate removal for maintenance. The damper operates due to the pressure difference across the disc and hence no drive unit is necessary. It automatically changes over to the duct with a higher operating air pressure. During normal operation, the disc locates at one of the extreme positions; it does not locate in any intermediate position.

d)

Wind Box Dampers Refer to Figures 2-13 and 2-14.

MM-M02 Rev.000 (17.07.13)

Multi-Louver type control dampers are used in the windboxes to regulate combustion and auxiliary air to the burner assemblies. The windbox dampers are further classified as burner dampers and AA-port (additional air port) dampers. The burner dampers allow air supply for the proper combustion of coal and oil. The air supplied through the AA-port dampers controls NOx in the flue gas. The auxiliary air dampers in the burner damper assemblies are of Single-flap type control dampers. The remaining coal, oil and AA-port dampers are also Multi-Louver type control dampers.

Boiler Ducts and Dampers

2-15

Chapter 2 General

The burner dampers are located vertically, in three assemblies, one above the other in all eight corners of furnace waterwall. They are located adjacent to the three burner assemblies. The AA-port dampers are located in the eight corners of the furnace. The pneumatic cylinders and their linkage mechanisms are mounted on the respective damper frame work. The burner damper assemblies are bolted to the inlets of the respective wind boxes. The wind box dampers are not leak-proof in the closed position. A small quantity of air is allowed to bleed through the dampers for cooling the burner and AA-port nozzles from furnace radiation. Hence, the damper blades are not provided with any type of special sealing arrangement at the tips and sides. The major components of a wind box damper are as follows:



Damper frame



Blade and shaft assembly



Gland sealing arrangement



Actuators.

Damper Frame The damper frame is a fabricated Carbon Steel structure formed by channel beams. Each damper frame is sectioned using partition plates. The damper frame is partitioned to allow flow of air for coal, oil, auxiliary air and over-fire air separately. Steel angles (25 x 25 x 3 mm) welded lengthwise at the top and bottom of each compartment perform as stoppers for the blades in closed position. The stoppers also serve as seal for the damper. The damper frame has openings to allow insertion of the damper shaft at both ends. The shaft bearings and the gland packing are mounted, around the shaft, outside the damper frame.

MM-M02 Rev.000 (17.07.13)

Blade and Shaft Assembly Each damper blade is made of 4 mm thick Carbon steel plates. The blade is secured to a shaft (32 mm Ø) U-bolts and nuts at three locations for the burner dampers and four for AA-port dampers. The U-bolts are equally spaced along the shaft. The U-bolts are welded to the shafts after full tightening. The nuts, after tightening, are tack-welded to the blades to prevent loosening. Boiler Ducts and Dampers

2-16

Chapter 2 General

The two blades of a multi-louver damper are linked together by a linkage arrangement internally to ensure simultaneous movement of blades. The two blades open/close in opposite directions. Each shaft is supported by bearing on either side of the damper frame. These bearings provide smooth rotary movement of the blades. The drive shafts are longer than the stub shafts and they extend outside of the damper frame. Each driving shaft is provided with a gland packing arrangement at the location of frame penetration. The position of the damper blade is engraved on each drive shaft with a line-mark. In addition, position indicators are provided on the frame to indicate position of each damper.

Gland Sealing Arrangement A gland sealing arrangement is provided around the drive shaft where it protrudes the frame. The gland arrangement is provided in the DE bearing as indicated in Figures 2-13 and 2-14. The outer end of the DE bearing is flanged and provided with a slot to retain the gland packing. A set of 6.4 mm square section non-asbestos packing are inserted into the bearing slot and retained by a gland follower. The gland follower is sufficiently tightened to prevent leakage. Over-tightening of the gland follower would result in sticky operation of the damper.

Drive Unit The wind box dampers are driven by pneumatic power cylinders mounted on the damper frame. A support post is welded onto the damper frame and the pneumatic cylinder is hinged on this support at its rear end. The clevis screwed on the piston rod is connected to the drive lever using a hinge pin.

MM-M02 Rev.000 (17.07.13)

The hinged support enables the power cylinder to transform linear movement of the power cylinder into circular movement of the lever. The power cylinder is operated by compressed instrument air from the Instrument Air System which is free from moisture, oil and dirt.

Boiler Ducts and Dampers

2-17

Chapter 2 General

e)

Guillotine Damper Refer to Figure 2-15 & 2-16. Guillotine type dampers are provided in the inlet and outlet of the ESPs. These dampers are of ON-OFF type and remain either in fully open or close position. The dampers are of a glandular spade guillotine type in construction. The guillotine damper consists of a frame, fabricated from Carbon steel plates. Mating flanges, fabricated from carbon steel, are welded to each end of the frame to secure the damper to the ducting. The damper blade assembly, fabricated from Carbon steel plates, is located within the damper frame. Seal plates are bolted to the edges of the damper blade. The seal plates butt against the damper seats and provide effective sealing when closed. The drive end and non-drive end of line shaft are coupled with universal coupling in the middle. The shaft is supported at both ends, outside the frame, using pillow block type bearings. Two gear boxes are coupled with electric actuator and drive end and non-drive end of the line shaft. In the drive side, both ends of drive screw are coupled with two line shafts by flexible couplings. In the non-drive side, drive screw is coupled with one line shaft by flexible coupling too. The electric actuator for the damper is also coupled with line screw by another flexible coupling. This actuator is mounted on a support bracket welded onto the damper frame around the drive-end line shaft. The electric actuator is supported and hinged at the middle to enable angular movement of the driving lever.

MM-M02 Rev.000 (17.07.13)

Limit switches are provided to detect open or closed position in the central control room. A position indicator plate is installed on the damper drive-end line shaft to provide local indication.

Boiler Ducts and Dampers

2-18

General

MM-M02 Rev.000 (17.07.13)

Chapter-2

FIGURE 2-4 Boiler Ducts and Dampers

CONSTRUCTION OF A TYPICAL AIR/FLUE GAS DUCT 2-19

MM-M02 Rev.000 (17.07.13)

Chapter-2

FIGURE 2-5 Boiler Ducts and Dampers

General

CONSTRUCTION OF A TYPICAL NON-METALLIC EXPANSION JOINT (1 OF 2) 2-20

General

MM-M02 Rev.000 (17.07.13)

Chapter-2

FIGURE 2-6 Boiler Ducts and Dampers

CONSTRUCTION OF A TYPICAL NON-METTALLIC EXPANSION JOINT (2 OF 2) 2-21

General

MM-M02 Rev.000 (17.07.13)

Chapter-2

FIGURE 2-7 TYPICAL ARRANGEMENT OF AIR AND GAS DUCT SUPPORTS Boiler Ducts and Dampers

2-22

General

MM-M02 Rev.000 (17.07.13)

Chapter-2

FIGURE 2-8 TYPICAL ARRANGEMENT OF HANGER SUPPORTS Boiler Ducts and Dampers

IN AIR AND GAS DUCTS 2-23

MM-M02 Rev.000 (17.07.13)

Chapter-2

FIGURE 2-9 Boiler Ducts and Dampers

General

CONSTRUCTION OF A MULTI LOUVER DAMPER 2-24

General

MM-M02 Rev.000 (17.07.13)

Chapter-2

FIGURE 2-10 CONSTRUCTION OF A DUPLEX MULTI LOUVER DAMPER Boiler Ducts and Dampers

2-25

MM-M02 Rev.000 (17.07.13)

Chapter-2

FIGURE 2-11 Boiler Ducts and Dampers

General

CONSTRUCTION OF A BUTTERFLY DAMPER 2-26

MM-M02 Rev.000 (17.07.13)

Chapter-2

FIGURE 2-12 Boiler Ducts and Dampers

General

CONSTRUCTION OF A 3-WAY DAMPER ASSEMBLY 2-27

General

MM-M02 Rev.000 (17.07.13)

Chapter-2

FIGURE 2-13 CONSTRUCTION OF WINDBOX BURNER DAMPER ASSEMBLY Boiler Ducts and Dampers

2-28

General

MM-M02 Rev.000 (17.07.13)

Chapter-2

FIGURE 2-14 CONSTRUCTION OF AA-PORT DAMPER ASSEMBLY Boiler Ducts and Dampers

2-29

General

MM-M02 Rev.000 (17.07.13)

Chapter-2

FIGURE 2-15 Boiler Ducts and Dampers

CONSTRUCTION OF GUILLOTINE DAMPER ASSEMBLY (1/2) 2-30

General

MM-M02 Rev.000 (17.07.13)

Chapter-2

FIGURE 2-16 Boiler Ducts and Dampers

CONSTRUCTION OF GUILLOTINE DAMPER ASSEMBLY (2/2) 2-31

Chapter 3

Specifications

Chapter

3 Specifications TABLE 3-1

LOUVER DAMPERS

Damper Name

FD Outlet Damper

RAPH Outlet Secondary Air Damper

Windbox Secondary Air Damper

Damper Number

01HLA02AA101/102

01HLA05AA101/102

01HLA05AA701/702/703/704

Quantity

2

2

4

Damper Duty

ON-OFF

ON-OFF

REGULATION

Location

Outdoor

Outdoor

Outdoor

Direction of duct

Horizontal

Horizontal

Vertical

Type

Duplex Multi-Louver 8 blades

Duplex Multi-Louver 6 blades

Multi-Louver 2 blades

Size

4690 x 4690 (I/S FRAME)

3140x 9990 (I/S FRAME)

2590 x 4090 (I/S FRAME)

Total Weight(Approx.)

5500 kgs(Approx.)/Damper

7725 kgs(Approx.)/Damper

3000 kgs(Approx.)/Damper

Medium

Air

Air

Air

Flow rate (m /min)

15480

29580

10995

Temperature (ºC)

Maximum 50ºC

Maximum 375ºC

Maximum 375ºC

Pressure (mmWC)

Maximum (±)660 mmWC

Maximum (±)660 mmWC

Maximum (±)660 mmWC

Sealing Efficiency on 99.95%/99.88% C.S.A/Seal volumetric basis

99.95%/99.88%

99.95%/99.88%

Bearing Type

Grease lubricating Spherical Bearing

High Temperature Self Lubricating Type

Grease lubricating Spherical Bearing

Operating Time (in sec)

30

30

30

Actuator Type

Electric Actuator

Electric Actuator

Pneumatic Actuator

Seal Type

Leaf Spring type

Leaf Spring type

Leaf Spring type

Flange

Carbon Steel, IS:2062 Gr. B

Carbon Steel, IS:2062 Gr. B

Carbon Steel, IS:2062 Gr. B

Frame

Carbon Steel, IS:2062 Gr. B

Carbon Steel, IS:2062 Gr. B

Carbon Steel, IS:2062 Gr. B

Blade

Carbon Steel, IS:2062 Gr. B

Carbon Steel, ASTM A 516 GR 70

Carbon Steel, ASTM A 516 GR 70

Stub Shaft

Carbon Steel, BS:970 080 M40 (EN-8)

Stainless Steel, ASTM A479 TYPE 410

Stainless Steel, ASTM A479 TYPE 410

Drive Shaft

Carbon Steel, BS:970 080 M40 (EN-8)

Stainless Steel, ASTM A479 TYPE 410

Stainless Steel, ASTM A479 TYPE 410

Seal

Stainless Steel, BS:5770 316 S16 TR-280

Stainless Steel, BS:5770 316 S16 TR-280

Stainless Steel, BS:5770 316 S16 TR-280

3

MM-M02 Rev.000 (17.07.13)

Material

Boiler Ducts and Dampers

3-1

Chapter 3

Specifications

Cont’d. from previous page..

TABLE 3-1

LOUVER DAMPERS

Damper Name

RAPH Inlet Cold Primary Air Damper

RAPH Outlet Hot Primary Air Damper

Pulverizer Inlet Hot Primary Air Damper

PA Fan Outlet Cold Primary Air Damper

Damper Number

01HFE03AA101/102

01HFE05AA101/102

01HFE05AA701/703/70 5/707/709/711

01HFE03AA103/104

Quantity

2

2

6

2

Damper Duty

ON-OFF

ON-OFF

REGULATION

ON-OFF

Location

Outdoor

Outdoor

Outdoor

Outdoor

Direction of duct

Horizontal

Horizontal

Vertical

Horizontal

Type

Duplex Multi-Louver

Duplex Multi-Louver

Multi-Louver

Duplex Multi-Louver

3 blades

3 blades

2 blades

2 blades

3090 x 3890 (I/S FRAME)

3590 x 2640 (I/S FRAME) 1890 x 2290 (I/S FRAME) 2090 x 2790 (I/S FRAME)

Size

Total 3300 Weight(Appro kgs(Approx.)/Damper x.)

2900 kgs(Approx.)/Damper

2500 kgs(Approx.)/Damper

2000 kgs(Approx.)/Damper

Medium

Air

Air

Air

Air

Flow rate 3 (m /min)

6450

5460

2760

3270

Temperature (ºC)

Maximum 60ºC

Maximum 375ºC

Maximum 375ºC

Maximum 60ºC

Pressure (mmWC)

Maximum (+)1627 mmWC/(-)660 mmWC

Maximum (+)1627 mmWC/(-)660 mmWC

Maximum (+)1627 mmWC/(-) 660 mmWC

Maximum (+)1627 mmWC/(-) 660 mmWC

Sealing Efficiency on C.S.A/Seal volumetric basis

99.95%/99.88%

99.95%/99.88%

99.95%/99.88%

99.95%/99.88%

Bearing Type

Grease lubricating Spherical Bearing

Grease lubricating Spherical Bearing

High temperature self lubricating Spherical Bearing

Grease lubricating Spherical Bearing

Operating Time (in sec)

30

30

30

30

Actuator Type Electric Actuator

Electric Actuator

Pneumatic Actuator

Electric Actuator

Seal Type

Leaf Spring type

Leaf Spring type

Leaf Spring type

Leaf Spring type

Flange

Carbon Steel, IS:2062 Gr. B

Carbon Steel, IS:2062 Gr. B

Carbon Steel, IS:2062 Gr. B

Carbon Steel, IS:2062 Gr. B

Frame

Carbon Steel, IS:2062 Gr. B

Carbon Steel, IS:2062 Gr. B

Carbon Steel, IS:2062 Gr. B

Carbon Steel, IS:2062 Gr. B

Blade

Carbon Steel, IS:2062 Gr. B

Carbon Steel, ASTM A 516 GR 70

Carbon Steel, ASTM A 516 GR 70

Carbon Steel, IS:2062 Gr. B

Stub Shaft

Carbon Steel, BS:970 080 M40 (EN-8)

Stainless Steel, ASTM A479 TYPE 410

Stainless Steel, ASTM A479 TYPE 410

Carbon Steel, BS:970 080 M40 (EN-8)

Drive Shaft

Carbon Steel, BS:970 080 M40 (EN-8)

Stainless Steel, ASTM A479 TYPE 410

Stainless Steel, ASTM A479 TYPE 410

Carbon Steel, BS:970 080 M40 (EN-8)

Seal

Stainless Steel, BS:5770 316 S16 TR-280

Stainless Steel, BS:5770 316 S16 TR-280

Stainless Steel, BS:5770 316 S16 TR-280

Stainless Steel, BS:5770 316 S16 TR-280

MM-M02 Rev.000 (17.07.13)

Material

Boiler Ducts and Dampers

3-2

Chapter 3

Specifications

Cont’d. from previous page..

TABLE 3-1

LOUVER DAMPERS

Damper Name Pulverizer Inlet Cold Primary Air Damper

RAPH Inlet Gas Damper

RAPH Outlet Gas Damper

ID Fan Outlet Damper

Damper Number 01HFE03AA701/703/ 705/ 707/ 709/711

01HNA03AA101/102

01HNA04AA101/102

01HNA06AA101/102

Quantity

6

2

2

2

Damper Duty

REGULATION

ON-OFF

ON-OFF

ON-OFF

Location

Outdoor

Outdoor

Outdoor

Outdoor

Direction of duct Horizontal

Horizontal

Horizontal

Horizontal

Type

Multi-Louver

Duplex Multi-Louver

Duplex Multi-Louver

Duplex Multi-Louver

2 blades

8 blades

8 blades

10 blades

1090 x 1790 (I/S FRAME)

4086 x 15286 mm (I/S 3786 x 11686 (I/S FRAME) FRAME)

4900 x 6000 (I/S FRAME)

Total 1800 Weight(Approx.) kgs(Approx.)/Damper

9500 kgs(Approx.)/Damper

8500 kgs(Approx.)/Damper

8900 kgs(Approx.)/Damper

Medium

Air

Flue Gas

Flue Gas

Flue Gas

Flow rate 3 (m /min)

1200

46380

30600

28965

Temperature (ºC)

Maximum 60ºC

Maximum 400ºC

Maximum 170ºC

Maximum 170ºC

Pressure (mmWC)

Maximum (+)1627 mmWC/(-) 660 mmWC

Maximum (±)660 mmWC

Maximum (±) 660 mmWC

Maximum (+) 200 mmWC

Sealing 99.95%/99.88% Efficiency on C.S.A/Seal volumetric basis

100%

99.95%

100%

Bearing Type

High Temperature Self Lubricating Type

High Temperature Self Lubricating Type

High Temperature Self Lubricating Type

Operating Time 30 ( in sec)

30

30

30

Actuator Type

Pneumatic Actuator

Electric Actuator

Electric Actuator

Electric Actuator

Seal Type

Leaf Spring type

Leaf Spring type

Leaf Spring type

Leaf Spring type

Flange

Carbon Steel, IS:2062 Gr. B

Carbon Steel, IS:2062 Gr. B

Carbon Steel, IS:2062 Gr. B

Carbon Steel, IS:2062 Gr. B

Frame

Carbon Steel, IS:2062 Gr. B

Carbon Steel, IS:2062 Gr. B

Carbon Steel, IS:2062 Gr. B

Carbon Steel, IS:2062 Gr. B

Blade

Carbon Steel, IS:2062 Gr. B

Carbon Steel, ASTM A 516 GR 70

Carbon Steel, IS:2062 Gr. B

Carbon Steel, IS:2062 Gr. B

Stub Shaft

Carbon Steel, BS:970 080 M40 (EN-8)

Stainless Steel, SS 410

Carbon Steel, BS:970 080 M40 (EN-8)

Carbon Steel, BS:970 080 M40 (EN-8)

Drive Shaft

Carbon Steel, BS:970 080 M40 (EN-8)

Stainless Steel, SS 410

Carbon Steel, BS:970 080 M40 (EN-8)

Carbon Steel, BS:970 080 M40 (EN-8)

Seal

Stainless Steel, BS:5770 316 S16 TR-280

Stainless Steel, SS 316

Stainless Steel, BS:5770 316 S16 TR-280

Stainless Steel, BS:5770 316 S16 TR-280

Size

Grease lubricating Spherical Bearing

MM-M02 Rev.000 (17.07.13)

Material

Boiler Ducts and Dampers

3-3

Chapter 3

TABLE 3-2

Specifications

BUTTERFLY DAMPERS

Damper Name

Flame Detector Cooling Air Fan Inlet On-Off Damper

Damper Number

01HXA01AA101/102

Quantity

2

Damper Duty

ON-OFF

Location

Outdoor

Direction of duct

Horizontal

Type

Multi-Louver 6 blades

Size

Ø1210 (I/S FRAME)

Total Weight(Approx.)

700 kgs(Approx.)/Damper

Medium

Air 3

Flow rate (m /min)

105

Temperature (ºC)

Maximum 50ºC

Pressure (mmWC)

Maximum (±) 660 mmWC

Sealing Efficiency on C.S.A/Seal volumetric basis

99.95 %

Bearing Type

High Temperature Type

Operating Time (in sec)

10

Actuator Type

Electric Actuator

Seal Type

Leaf Spring type Carbon Steel, IS:2062 Gr. B

Frame

Carbon Steel, IS:2062 Gr. B

Blade

Carbon Steel, IS:2062 Gr. B

Stub Shaft

Carbon Steel, BS:970 080 M40 (EN-8)

Drive Shaft

Carbon Steel, BS:970 080 M40 (EN-8)

Seal

Stainless Steel, BS:5770 316 S16

MM-M02 Rev.000 (17.07.13)

Flange

Boiler Ducts and Dampers

3-4

Chapter 3

TABLE 3-3

FLAP TYPE DAMPERS

Damper Name

Pulverizer Inlet Hot Primary Air Isolation Damper

Damper Number

01HFE05AA702/704/706/708/710/712

Quantity

6

Damper Duty

ON-OFF

Location

Outdoor

Direction of duct

Horizontal

Type

Twin Seal Double Flap type

Size

1890 X 2290 (H X W)-900 F/F

Total Weight(Approx.)

3000 kgs (Approx.)/Damper

Medium

Air 3

Specifications

Flow rate (m /min)

2760

Temperature (ºC)

Design 375ºC

Pressure (mmWC)

Maximum (+)1627 mmWC/(-)660 mmWC

Sealing Efficiency on C.S.A/Seal volumetric basis

99.999%/99.88%

Bearing Type

High Temperature Type

Operating Time (in sec)

20

Actuator Type

Pneumatic Actuator

Seal Type

Leaf Spring type Carbon Steel, IS:2062 Gr. B

Frame

Carbon Steel, IS:2062 Gr. B

Blade

Carbon Steel, ASTM A 516 GR 70

Stub Shaft

--

Drive Shaft

Stainless Steel, ASTM A479 TYPE 410/EN-57T

Seal

Stainless Steel, BS:5770 PART-4 316 S16 TR-280

MM-M02 Rev.000 (17.07.13)

Flange

Boiler Ducts and Dampers

3-5

Chapter 3

TABLE 3-4

Specifications

GUILLOTINE TYPE DAMPERS

Damper Name

ESP Inlet Isolation Damper

Damper Number

01HNA04AA103/104/105/106/107/108/109/110/111/112/113/114

Quantity

12

Damper Duty

ON-OFF

Location

Outdoor

Direction of duct

Horizontal

Type

Glandular Spade Guillotine type

Size

4300 X 1600 (H X W) (I/S Frame)

Total Weight(Approx.)

5000 kgs (Approx.)/Damper

Medium

Flue Gas 3

Flow rate (m /min)

4895

Temperature (ºC)

Design 170ºC

Pressure (mmWC)

Design (-)473 mmWC

Sealing Efficiency on C.S.A

100%

Bearing Type

High Temperature Type

Operating Time (in sec)

300

Actuator Type

Electrical Actuator (With Integral Starter)

Seal Type

Bulb seal Carbon Steel, IS:2062 Gr. B

Frame

Carbon Steel, IS:2062 Gr. B

Blade

Carbon Steel, IS:2062 Gr. B

Line Shaft

Carbon Steel BS:970 080 M40 (EN-8)

Drive Screw

Carbon Steel BS:970 080 M40 (EN-8)

Seal

Stainless Steel, BS:5770 PART-4 316 S16 TR-280

MM-M02 Rev.000 (17.07.13)

Flange

Boiler Ducts and Dampers

3-6

Chapter 3

TABLE 3-5 Section

Damper Description

Damper Number

Specifications

3 – WAY DAMPERS Damper Type

Sectional Dimension (mm)

Quantity

Operation

Drive unit

Cooling Air

01HXA01 AA001

Flame detector cooling air fan suction damper

Self Closing Damper

600DN

1

Automatic Self changeover actuated

Cooling Air

01HXA01AA006

Flame detector cooling air fan discharge damper

Self Closing Damper

600DN

1

Automatic Self changeover actuated

Sealing Air

01HWA01AA025/026

RAPH seal air damper

Self Closing Damper

200DN

2

Automatic Self changeover actuated

TABLE 3-6

DESIGN PRESSURE FOR AIR AND GAS DUCTS Design Pressure

Section (+) Pressure (mmAq.)

(-) Pressure (mmAq.)

FDF ~ RAPH

480

-242

RAPH ~ BWB

230

-295

PAF (inlet)

-75

-295

PAF ~ RAPH

1405

-

RAPH ~ PULVERIZER

1245

-

PRIMARY COLD DUCT

1405

-

ECO ~ RAPH

-

-383

RAPH ~ ESP

-

-583

ESP ~ IDF

-

-583

200

-

MM-M02 Rev.000 (17.07.13)

IDF ~ STACK

Boiler Ducts and Dampers

3-7

Chapter 3

TABLE 3-7

Part

Section

Specifications

NON-METALLIC EXPANSION JOINTS

Expansion Internal Qty/ Joint Fluid Boiler No.

Design Fabric Type

Press.

Movements

Design Temp. (ºC)

(mmWc)

Dimension (mm)

(mm) Ax

Lat

300

(+)50.5

9.2

300

(+)73.4

-

Air duct

RAPH ~ BWB

AE03 R/L

Air

2

Thermoflex C40(OW)

±660

375

Air duct

RAPH ~ BWB

AE10 R/L

Air

2

Thermoflex C40(OW)

±660

375

AE43 R/L

Air

2

Thermoflex C40(OW)

+1627

375

3000x4742

300

(+)58.3

19.4

duct

RAPH ~ COMMON

Gas duct

ECO ~ RAPH

GE01 R/L

Gas

Thermoflex C40(OW)

±660

400

15300x4100

700

(+)149.2

319.6

2

4900x5450

-660

MM-M02 Rev.000 (17.07.13)

Air

6190x9142

(mm)

Length

Boiler Ducts and Dampers

3-8

Chapter 4 Preventive Maintenance

Chapter

4 P r e v e n t iv e M a in t e n a n c e Preventive maintenance is carried out to avoid or minimize the possibility of failure or deterioration of equipment performance. This requires a constant effort from maintenance staff to ensure that the equipment is available on demand. There are two categories of preventive maintenance, Routine Maintenance and Annual Outage Maintenance. Routine maintenance helps to reduce the possibility of outage and hence the downtime of equipment. Annual outage maintenance is carried out to maintain the internal components of the installed equipment. Though manufacturer’s recommendations provide a good basis for the provision of a preventive maintenance schedule, the frequency and other details should be updated from time to time based on practical experience and actual field feedback gathered during inspection and normal operation of the equipment/plant. Consideration of these field related specific issues will make the preventive maintenance more effective.

4.1

Prerequisites The necessary prerequisites for the preventive maintenance of the boiler ducts and dampers are as follows:

4.1.1 Scheduling

MM-M02 Rev.000 (17.07.13)

Scheduling is the first activity in the preparation of a preventive maintenance program; the schedule is to include planning to attend all operating equipment on a fixed regular basis. Initially, schedules will be prepared based on vendor/manufacturer’s generic instructions. The schedules will, however, be updated (frequency, nature of inspection, etc.) as site specific data becomes available. Preventive maintenance is to be coordinated with other departments concerned. In the case of a major scheduled outage, maintenance personnel and other departments concerned should jointly produce a plan of activities well in advance to decide the inspection activities and other logistics (such as the availability and supply of required equipment spare parts, and tools, etc.). The schedule should clearly identify the critical path. Priority is to be assigned to specific tasks that also involve parallel activities to reduce the equipment downtime and to complete the work within the stipulated time schedule.

Boiler Ducts and Dampers

4-1

Chapter 4 Preventive Maintenance

4.1.2 Departmental Interface/Notification Departmental communication is essential and interfacing between departments is to be maintained to avoid any lack of communication that may arise and adversely affect routine or annual outage maintenance work. Prior to commencing preventive maintenance, all concerned persons (shift supervisor, operators, etc.) are to be made aware of the schedule and the nature of the activities that are to take place. If it becomes clear that there is a problem or a conflict of interests in the schedule (e.g. the maintenance schedule interferes with another group’s work), this is to be resolved by mutual agreement between the parties involved.

4.1.3 Isolation of Equipment It is important that isolations are agreed and valid clearances and work permits are obtained before any maintenance work is performed. The isolation boundaries of the particular equipment to be taken under maintenance are to be clearly identified. In the case of an electrical isolation, the power supply shall be disconnected and/or the fuses removed. In the case of mechanical isolation, the dampers or other mechanical means of isolation, at the isolation boundaries are to be closed and if possible locked in the closed position. The system within the isolation boundaries is to be ventilated and drained through drain pipes installed in the duct system.

4.1.4 Safety Precautions

MM-M02 Rev.000 (17.07.13)

Before the commencement of any maintenance work, the person in charge of the work site is to perform a risk assessment and method statement for the safe execution of the job scope activities, described within the work permit. Risk assessment includes identifying, recognizing and understanding the potential hazards associated with the work. The method statement is prepared to illustrate the safe working practices in accordance with the safety manual and the manufacturer’s instruction manual to prevent personal injury and/or equipment damage. Prior to the commencement of actual work, the person carrying out the work is to make a safety check based on the above method statement and also use his own judgment to ensure that the equipment and the prevailing working conditions are safe. During maintenance work, every employee should follow the safe working procedures detailed in the method statement.

Boiler Ducts and Dampers

4-2

Chapter 4 Preventive Maintenance

4.2

Routine Maintenance The purpose of routine maintenance is the implementation of a preventive maintenance program on a day-to-day basis through a planned and correctly executed inspection. The routine maintenance activities are very important and, if they are properly carried out, they will enhance equipment reliability. As a result, good routine maintenance activities may help in cost reduction in the long run by way of a reduction in equipment downtime. Cleaning is an important and necessary maintenance activity to prevent the ingress of foreign materials. Other major points are as follows: (Summarized major routine activities are also tabulated in Table 4-1).

4.2.1 Preparation a)

Parts, Tools and Equipment It is important to prepare the necessary parts, tools and equipment before commencing actual work. Routine maintenance requires a standard mechanical tool kit, consumables, cleaning materials etc. Any shortages of these items will affect the maintenance activity and may delay the schedule. Personal Protective Equipment (PPE) is necessary for maintenance staff at all times. Upon completion of work, all tools and equipment should be serviced and stored correctly to ensure availability for further use.

b)

Documentation

MM-M02 Rev.000 (17.07.13)

Documentation is an important part of any maintenance duty. All findings should be noted on a comprehensive log sheet, reporting all aspects of the equipment observed during the routine inspection. The data recorded in these documents will be useful in determining the root cause of equipment failure found during annual outage/corrective maintenance work. Any abnormalities, if observed, are to be immediately communicated to the concerned department/personnel for rectification and are to be detailed in the report.

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4.2.2 Inspection and Maintenance

Wear proper SAFETY gadgets when performing inspection and maintenance of ducts and dampers. Leaking hot air is extremely dangerous and can cause severe burn injuries.

Ensure that the damper mechanical lock is engaged before entering a duct during boiler operation to prevent fatal accident.

a)

Ducts The silencer provided at the FD and PA fans suction duct are to be inspected for any damage or accumulation of any foreign materials on the screen. Carefully remove any foreign objects from the screen.

Note Do not carry any small loose items while clearing the above blockage. These can be drawn into the fan because of the suction pressure, Secure the loose items properly if carrying such items unavoidable.

MM-M02 Rev.000 (17.07.13)

The boiler ducts are to be externally inspected carefully for any corrosion or welding leakage when the boiler is in service. Leakage can be detected by hissing noise, fly ash leakage or by obvious de-colorization of the ducts or the insulation cladding. Perform repair depending upon the severity of the leakage and the plant operational requirements. Patch-up welding can be done if the boiler is to be restarted urgently. The manhole doors on the ducts are to be inspected for leakage of air or flue gas. Tighten the door fasteners immediately to arrest the leakage. Replace sealing ropes or gaskets with new ones during the next available shutdown, if leakage cannot be arrested by tightening. Inspect the non-metallic expansion joints for any leakage. Make a note of any leakage and rectify or replace the damaged expansion joint during the next available shut down.

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CAUTION During boiler maintenance, care must be taken that workers working on the floor above the Non metallic expansion joints do not inadvertently drop a tool and damage the joints.

CAUTION When welding or replacement work is done near Non metallic expansion joints, provide protection against burn damage or damage caused by being hit by replacement parts.

The duct supports, guides and stoppers are to be inspected for their integrity and for proper movement in their designated directions. Any obstruction to free movement can cause problems for the supports and/or the connected equipment. The cause of the restricted movement should be identified and rectified immediately or during next shut-down depending on the severity of such restriction. This can usually be done without affecting the unit operation. The hanger supports are to be inspected for their integrity having no loose/missing parts and proper movement of expansion must be checked. Repair or replace any missing or damaged component immediately. Check that the movement of spring hangers conforms with the recommended ‘HOT’ position marked on the spring housings. Remove any restriction to free movement of hanger supports at the first instance. Problem with one hanger support can lead to increased loading on the nearby supports and lead to their failure.

MM-M02 Rev.000 (17.07.13)

The hoppers on the flue gas ducts are to be inspected for ash accumulation at regular intervals. Ash accumulation leads to increased loading on the duct supports and ash loading on the EPs. Increased ash loading can lead to deterioration in the performance of EPs. Evacuate accumulated ash immediately manually or by ash removal equipment, following the recommended procedures. The insulation cladding sheets on the hot air and flue gas ducts are to be inspected for their integrity or damage. Replace with new sheets if any cladding sheet is found damaged. Secure loose cladding sheets to their original positions with proper screws.

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b)

Multi-Louver Dampers Check with operating personnel for details of any operational problems of a damper and investigate as necessary. The multi-Louver dampers are to be checked for smooth operation. A sticky damper is to be checked for friction between stationary and moving parts, tight gland packing and damaged bearings. Replace any damaged bearing or gland packing and provide necessary clearance between moving and stationary parts during shut-down. The multi-Louver dampers are to be visually inspected for the presence of any sticking or loose linkage/hinge pins and connecting links. Restore loosened pins and connecting links and secure them with proper washers and split pins. An external inspection should include a check for missing link pins and bent or damaged links. Record any damage and repair damaged links and pins during a shut-down. Replace and secure with new ones if any pin or link is damaged beyond repair. The damper shafts are to be checked for any air or gas leakage from the shaft glands. Gland leakage is to be corrected by tightening the gland packing follower. If leakage persists, replace the gland packing during a shut down. The damper actuators are to be checked for any leakage of instrument air. Rectify air leakage immediately on notice. The drain cock on each actuator of the air-filter regulator is to be opened at regular intervals and checked for the ingress of moisture. If water is observed, investigate and rectify the air driers in the Instrument Air System.

c)

Butterfly Damper

MM-M02 Rev.000 (17.07.13)

The butterfly dampers are to be checked for smooth operation. A sticky damper is to be checked for friction between stationary and moving parts, tight gland packing and damaged bearings. Replace any damaged bearing and provide necessary clearance between moving and stationary parts during shut-down. The butterfly dampers are to be visually inspected for the presence of any loose or missing linkage/hinge pins. Restore the loosened pins and secure them with proper washers and split pins. Replace with new ones if any pin is damaged beyond repair. The damper shafts are to be checked for any air leakage from the shaft glands. Gland leakage is to be corrected by tightening the gland packing follower. If leakage persists, replace the gland packing during next planned shut down. Boiler Ducts and Dampers

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The damper actuators are to be checked for any leakage of instrument air. Rectify air leakage immediately on notice. The drain cock on each actuator of air-filter regulator is to be opened at regular intervals, and checked for the presence of moisture. If water is observed, investigate and rectify the air driers in the Instrument Air System.

d)

3-Way Damper The 3-way dampers are to be checked for change-over. A sticky damper is to be checked for damaged bearings. Shut down and replace damaged bearings. The damper is to be checked for air leakage at the shaft ends. Tighten the end covers if minor leakage is observed. If the leakage persists, replace O-rings at the next available shutdown. The 3-way dampers are to be checked for air leakage from the flanges. Tighten the fasteners and correct the leakage. If the leakage persists, it should be attended at the next available shutdown. The standby cooling fan is to be checked for reverse rotation during operation. If reverse rotation is observed, the damper disc or seat should be inspected for any deformation or damage and the problem resolved.

e)

Wind Box Dampers The eight windbox dampers in the same elevation are to be checked for uniform opening. Non-uniform damper opening will affect the quality of flame in the furnace. Check for control air leakage, defective air cylinder or jammed damper. Investigate and remove the cause for non-uniform opening.

MM-M02 Rev.000 (17.07.13)

The windbox dampers are to be checked for smooth operation. A sticky damper is to be checked for damaged bearings and over-tight gland packing. Replace damaged bearings and gland packing with new during next shutdown. The windbox dampers are to be visually inspected for the presence of any loose or missing linkage pins. Restore the loosened pins and secure them with proper washers and split pins. The damper shafts are to be checked for any air leakage from the shaft glands. Gland leakage is to be corrected by tightening the gland packing follower. If leakage persists, replace the gland packing during next available shut down.

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The damper actuators are to be checked for any instrument air leakage. Rectify air leakage immediately on notice.

f)

Guillotine Damper The guillotine dampers are to be checked for smooth operation. It should be checked for friction free movement between stationary and moving parts. The gland packing and damaged bearings are also to be checked. Replace any damaged bearing and provide necessary clearance between moving and stationary parts during shut-down. The guillotine dampers are to be visually inspected, if any looseness appeared in mating flange, mating flange hardware and gasket. Tighten the loosened mating flange, its hardware and gasket. Replace with new ones if any parts found in damaged condition beyond repair. Frame seals are to be visually inspected and replace the same, if found any damage. Blade connection and side frame connection are to be checked and if found any loosened bolts tighten the loosened bolts immediately with the help of spring washers. The damper line shafts are to be inspected for any damage due to pitting, rusting or seizure. Defective line shafts should be rectified or replaced. Flexible coupling and universal coupling are to be checked for any loosened coupling bolts. Tighten the loosened coupling bolts immediately on notice. The electrical actuator needs to be checked for any loosened mounting bolts. Tighten the loosened mounting bolts immediately on notice.

MM-M02 Rev.000 (17.07.13)

Gearbox connection and actuator connection are to be checked for any loosened bolts and if found any loosened bolts, tighten the loosened bolts immediately with the help of spring washers.

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TABLE 4-1

No.

1

Description

Ducts

Major Check Item

Check Method

ROUTINE MAINTENANCE CHECKLIST

Check Reference

Action to be Taken (if beyond acceptable limit)

Remarks

Recommended Maintenance Frequency

Debris accumulation on FD fan suction duct silencer

Visual

No debris

Clear debris

Monthly

Debris accumulation on PA fan suction duct silencer

Visual

No debris

Clear debris

Monthly

Air or flue gas leakage

Visual

No leakage

Repair weld joints

Monthly

No leakage

Tighten door fasteners. If leak persists replace gasket.

Monthly

Ash accumulation in duct Visual, Installed hoppers instruments

No ash accumulation

Empty ash hoppers

Daily

Insulation cladding

Visual

No loose cladding or No rain ingress

Repair and replace insulation cladding after shutdown.

Monthly

Damage or leakage

Visual

No leakage or damage

Repair or replace expansion joint after shutdown

6 months

Visual

Design expansion movement

Remove obstruction for free movement

Weekly

Visual

No missing or Replace and secure loose or loose components missing components

Audible Manhole door leakage

Visual Audible

2

Duct supports, Proper expansion guides, movement stoppers, Loose or missing hangers components

Audible

6 months

MM-M02

Rev.000 (17.07.13)

3

Expansion Joints

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Cont’d. from previous page.. TABLE 4-1

No.

3

4

Description

(Continued)

Multi-Louver damper

Check Method

Spring hanger expansion movement

Visual

Spring hanger expansion movement

Visual

Smooth operation

Visual

Check Reference

Action to be Taken (if beyond acceptable limit)

Movement to match design HOT position

Check and adjust spring hanger for the correct COLD setting.

Movement to match design HOT position

Check and adjust spring hanger for the correct COLD setting.

Smooth operation

Remove friction between stationary and moving parts.

Butterfly damper

Replace damaged bearings.

Guillotine Damper

6 months

6 months

Daily

No missing pins or damaged links

Repair or replace

Daily

Air / flue gas Visual leakage from shaft glands and damper joints

No leakage

Repair at the earliest opportunity

Daily

Instrument air leakage

Audible

No air leakage

Rectify leakage

Daily

Presence of moisture in instrument air

Visual

Dry air

Check operating instrument air drier and changeover to standby drier

Daily

MM-M02

Visual

Recommended Maintenance Frequency

Remove expansion constraint.

Replace over-tightened gland packing.

Missing link pins and damaged links

Remarks

Remove expansion constraint.

3-way damper

Windbox damper

Rev.000 (17.07.13)

Major Check Item

ROUTINE MAINTENANCE CHECKLIST

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Cont’d. from previous page.. TABLE 4-1

No.

(Continued)

Major Check Item

Check Method

Check Reference

Reverse rotation of standby cooling fan

Visual

No reverse rotation

Uniform operation of windbox dampers in the same elevation

Visual

Uniform opening

Action to be Taken (if beyond acceptable limit) Check and rectify 3-way damper seat and disc

Check instrument air leakage

Remarks

Recommended Maintenance Frequency Daily

Daily

Check and rectify sticking damper Check and replace defective actuator

MM-M02

Rev.000 (17.07.13)

4

Description

ROUTINE MAINTENANCE CHECKLIST

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4.3

Annual Outage Maintenance The purpose of annual outage maintenance is the implementation of a preventive maintenance program on a yearly basis through a planned and correctly executed maintenance work program accompanying necessary inspections. The annual outage maintenance activities are very important in the sense that if properly executed, these enhance the life and reliability of equipment. Major activities related to annual outage maintenance are as follows (Summarized major activities for annual outage maintenance are also shown in Table 4-2):

4.3.1 Preparation a)

Parts, Tools and Equipment Refer to Subsection 4.2.1 a), Parts, Tools and Equipment. In addition, it will be necessary to identify and make an indent for any spare part that may be required. Annual outage will, in certain cases, require the use of material handling equipment. A set of standard mechanical tool kit, consumables, cleaning agents and waste cloth are required. Any shortages of these items will affect the maintenance activity and hence the schedule. Disconnect the electrical power supply for the motor and de-link the actuator from the motor operated dampers. Isolate the instrument air connection to the power cylinders before disconnecting the cylinders from the damper shafts. Personal Protective Equipment (PPE) such as gloves, goggles, safety boots, masks, safety harness etc, has to be arranged and should be used by maintenance staff at all times. Unused spare parts are to be returned for correct storage and the procurement of used spare parts should be arranged.

MM-M02 Rev.000 (17.07.13)

All tools and tackle should be returned to the stores after servicing and cleaning.

b)

Documentation Refer to Subsection 4.2.1 b), Documentation. Records are to be maintained to record information regarding spares and consumables used. These records will be used for future reference and spare parts replenishment.

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On completion of annual outage maintenance work, the equipment is to be monitored for correct operation and maintenance data logging. This will help to determine the correct intervals of preventive maintenance activities to ensure optimum plant and equipment availability. The prompt recording of the findings during an inspection will build a valuable document for future reference.

4.3.2 Inspection and Maintenance

Do not enter into the ducts in service until the boiler has been shut down and isolated and the ducts sufficiently cooled to enter. Severe burn injuries can occur if entry is made into a hot duct.

Enter a boiler duct only if oxygen content is above the safe limit. Presence of CO gas and insufficient oxygen content inside the duct can lead to fatal accidents.

MM-M02 Rev.000 (17.07.13)

Do not make the first entry into a duct alone. Always keep another person near the access door to provide external help during an emergency.

Use only approved lighting and hand-lamps inside a boiler duct. Use of lighting with higher voltages can lead to electrical shocks and fatal accidents.

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CAUTION Take care to place DANGER sign board outside the access door when performing inspection or maintenance inside of the ducting. This is to ensure that the access door is not closed accidentally when internal work is in progress.

CAUTION Remove the link pin between the damper and the actuator during inspection or maintenance on the ducts and dampers.

CAUTION When separating joints and flanges, use jacking bolts and wooden mallets. Never apply force with hammers, chisels or screwdrivers.

The following procedure is applicable to the inspection and maintenance of ducts and dampers:

   

MM-M02 Rev.000 (17.07.13)



Enter the duct from the nearest manhole/access door provided. Use an approach ladder, where it is not possible to enter the duct from a platform. Use face mask and goggles when entering the duct. Remove insulation and cladding sheet at the location of the expansion joints and duct joints, if damage is suspected. Thoroughly clean the duct, expansion joints and duct supports prior to visual inspection.



Rectify any defect identified during inspection.



Replace the access door gaskets with new.

 

Service the access door fasteners before re-using them. Damaged fasteners should be replaced. Use only approved temporary lighting in the inspection areas.

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CAUTION After completing the internal inspection, remove all the temporary ladders, wooden planks, tools, approved lighting and other materials that were used inside the ducting.

a)

Ducts Please refer to Section 4.2.2 a), Routine Inspection and Maintenance of ducts. Any detects noted during the above inspection must be rectified during the annual outage. Any accumulation of loose debris is to be collected and removed. Remove temporary platform after inspection. Temporary platform may prevent proper thermal expansion after restart.

Ensure that the ducts are sufficiently cooled and well ventilated before entering.

Check the duct and auxiliary parts when operating air/gas draft in excess of design pressure. Unexpected damage may cause serious injury.

CAUTION Check the duct and Auxiliary parts when wind speed is excessive. Unexpected damage may cause serious injury.

MM-M02 Rev.000 (17.07.13)

CAUTION Where temporary platform is installed, walk only on the platform. Walking elsewhere may cause serious injury.

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CAUTION Do not touch measuring ports when boiler is operating without using aspirate line. Unexpected blow may occur because of positive pressure inside the duct. Aspirate line must be checked by confirming sounds which demonstrate that the aspirate air is working. The ducts are to be inspected internally for erosion and weld cracks. Any previously reported defects are to be investigated and repaired. Perform a thickness survey of ducts where erosion is apparent. However, if wear or erosion occurs repeatedly in any particular area, welding a wear plate in position should be considered as a solution to the problem. Checks for corrosion are to be performed at this time. Any corrosion encountered is to be removed and the resultant bare metal treated with an anti-corrosive paint. The struts and guide vanes within the ducts are to be inspected for their integrity, defective weld joints and erosion. Repair or replace defective or worn struts and guide vanes. If duct vibration was noticed during operation, the stiffeners and the struts at that location should be inspected and any defect noticed should be rectified. The non-metallic expansion joint with duct is to be inspected for any weld defect and necessary repairs performed. Defective weld joint should be repaired as necessary. Inspect the areas where the duct supports have been welded to the duct material. Check for any cracks and make necessary repairs.

MM-M02 Rev.000 (17.07.13)

The condition of the acoustic material of the FD fan and PA fan silencer are to be checked. Replace any defective acoustic material. The FD fan and PA fan silencer screen should be inspected for any damage or for the adherence of foreign materials. Any sticking foreign material should be removed and the screen thoroughly cleaned using a wire brush and compressed air. The ash hoppers in the flue gas ducts are to be inspected for accumulation of ash. The cause for any accumulation should be analyzed and remedial measures taken.

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The ducts for flue gas, hot secondary air and hot primary air are to be inspected for accumulation of ash within the ducts. Any abnormal accumulation should be investigated and measures taken to prevent such future accumulation.

b)

Expansion Joints Non-metallic Expansion Joint The non-metallic expansion joints are to be inspected for any physical damage. The rubber bellows should be inspected for cracks or puncture. Small defects can be repaired by vulcanizing. Expansion joints damaged beyond repair are to be replaced with new ones. The expansion joint cover plate should be opened and inspected for any ash accumulation between the cover plate and bellow. Clean the accumulated ash and inspect the expansion joints. Inspect the rubber expansion bellow for any puncture or deterioration. Defect noticed in the rubber bellow should be rectified. Replace bellow if the defect is beyond repair.

c)

Duct Supports The duct supports should be inspected for their intended function. Defects noted during routine inspection but remaining unattended should be rectified during this shutdown. The fix supports and rigid stoppers should be inspected for any damage or weld crack. Defective beam should be replaced and defective weld should be repaired as necessary. The sliding and guide supports should be free to expand in the designated direction. Any obstruction to free movement can cause strain on the supports and to the connected equipment. The slide plates (Teflon and SS304) should be inspected for free movement. Any restriction to free movement should be removed. Defective slide plates should be replaced.

MM-M02 Rev.000 (17.07.13)

The guide stoppers should be inspected for any damage or deformation. Defect noticed should be rectified by either replacing the stopper or re-welding it in its original position. The rigid hangers are to be inspected visually for their intended function and integrity. Repair or replace any defective component. The spring hanger supports are to be inspected for their intended function. Compare the HOT and COLD positions noted during operation and shutdown respectively with design values. Adjust Boiler Ducts and Dampers

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COLD position if necessary. Hangers which are not possible to adjust should be replaced with new ones.

d)

Dampers Louver Damper Visually inspect the damper frame and seats for deformation, corrosion or erosion. Repair or replace the defective parts as necessary. Visually inspect the damper blades for any damage, deformation, corrosion or erosion. Perform thickness survey of blades where erosion is apparent. Repair or replace the defective blades as follows: Completely worn blades are to be replaced with new blades. Where the wear is local and the blade thickness is < 4 mm for air side and < 6 mm for gas side, perform patch-welding to restore the blade to its original thickness. Inspect the pins, which secure the blades to the shaft, for looseness, damage or wear. Damaged, worn and missing pins should be replaced and the blades secured properly. The damper (provided with seal plates) is to be inspected for damage, wear or detachment of seal plates and their fixing bolts. Replace seal plates and bolts with new if damage or wear is apparent. The anti-friction bearings are to be inspected for any damage, pitting, rusting or seizure. The bush bearings are to be inspected for any damage on the bearing surface. Defective bearings should be replaced with new. Grease the bearings as required.

MM-M02 Rev.000 (17.07.13)

Inspect the shaft gland packing for any damage or deterioration and for the presence of ash deposit. Inspect the shaft sleeve for any damage or scratch on the packing surface. Replace new gland packing as per the procedure described below if damage or deterioration is observed: Loosen and remove the bolts securing the gland packing follower. Withdraw the gland packing follower and then remove the old gland packing from the stuffing box (using a jig). Clean the stuffing box with compressed air and insert new gland packing. Uniformly tighten the gland retainer bolts alternately, simultaneously rotating the blade, sufficient to prevent gland leakage.

Note Do not over-tighten the follower. Standard bolt tightening torque is 1~2 kg-m.

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The link rods and link pins are to be inspected for deformation, wear or damage. Defective link rods and link pins should be replaced. The actuator lever and the link pin are to be checked for wear or damage. Worn or damaged pin and lever should be rectified or replaced. The actuator support is to be checked for any weld crack. The actuator hinge pins should be checked for looseness, wear or damage. Defects noticed should be rectified. After inspection and replacement of defective parts, individual blades are to be checked for full opening and closing positions. Replace the link rod and link pins and then check operation of the full damper manually. Ensure proper closing and opening operation for each blade. If necessary adjust the link rod and turn-buckle and ensure full opening and closing positions. Ensure that the actuator is inspected and overhauled by the instrumentation and controls department. Operate and check for full travel and free movement of the power cylinder before connecting the damper. Connect the damper to the actuator, operate the damper locally and confirm that the damper operation is smooth. Set the local position indicator for full open and close positions. Operate the damper from Central Control Room (CCR) and ensure that the damper position in CCR matches the local indicator.

Butterfly Damper Visually inspect the damper frame and seats for deformation, corrosion or erosion. Repair or replace the defective parts as necessary.

MM-M02 Rev.000 (17.07.13)

Visually inspect the damper blade for any damage, deformation, corrosion or erosion. Perform thickness survey of blades where erosion is apparent. Repair or replace the defective blades as follows: Completely worn blades are to be replaced with new blades. Where the wear is local and the blade thickness is < 4 mm for air side, perform patch-welding to restore the blade to its original thickness. Inspect the fasteners, which secure the blades to the shaft, for looseness, damage or wear. Damaged, worn and missing fasteners should be replaced and the blades secured properly.

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The damper is to be inspected for damage, wear or detachment of seal plates and their fixing bolts. Replace seal plates and bolts with new if damage or wear is apparent. The damper bearings are to be inspected for any damage, pitting, rusting or seizure. Defective bearings should be rectified or replaced. Inspect the gland packing for any damage or deterioration and for the presence of ash deposit. Inspect the shaft sleeve and lantern ring for any damage or scratches. Rectify or replace sleeve and/or lantern ring if defective. Replace new gland packing as per the procedure described below if damage or deterioration is observed: Loosen and remove the bolts securing the gland packing follower. Withdraw the gland packing follower and then remove the old gland packing from the stuffing box (using a jig). Clean the stuffing box with compressed air and insert new gland packing. Uniformly tighten the gland retainer bolts alternately, while rotating the blade, sufficient to prevent gland leakage.

Note Do not over-tighten the follower. Standard bolt tightening torque is 1~2 kg-m.

Inspect the seal air nozzle and the flange connecting the nozzle to the seal air pipe. If seal air leakage was observed during operation, replace the gasket. The actuator lever and the link pin are to be checked for wear or damage. Worn or damaged pin and lever should be rectified or replaced. The actuator support is to be checked for any weld crack. The actuator hinge pins should be checked for looseness, wear or damage. Defects noticed should be rectified.

MM-M02 Rev.000 (17.07.13)

After inspection and replacement of defective parts, check that the blade moves freely to the full closing and opening positions. Ensure that the seal plates are in full contact with the seats. Readjust the seal plates and attain proper seating with the seats as per the following procedure: Holding the damper blades in the closed position, inspect the seal clearance with the seat. Loosen the fixing bolts and adjust the seals to obtain maximum contact with the seats. If required tap the seal plates with wooden hammers. Ensure that the actuator is inspected and overhauled by the instrumentation and controls department. Operate and check for

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full travel and free movement of the power cylinder before connecting the damper. Connect the damper to the actuator, operate the damper locally and confirm that the damper operation is smooth. Set the local position indicator for full open and close positions. Operate the damper from CCR and ensure that the damper position in CCR coincides with the local indicator.

3-way Damper Visually inspect the damper flap and seat for any damage, deformity, corrosion or erosion. Check that the flap is secured properly with the shaft. Repair or replace defective flap depending on the severity of damage. The shaft bearings and O-rings are to be inspected for any damage or scratches. Defective bearings and O-rings should be rectified or replaced.

Wind Box Dampers Visually inspect the damper blades for any damage, deformation or erosion. Perform thickness survey of blades where erosion is apparent. Repair or replace damaged or worn blades. Inspect the U-bolts and nuts, which secure the blade to the shaft, for looseness, damage or wear. Damaged and missing U-bolts and nuts should be replaced and the blades secured properly. Weld the U-bolt to the shaft and tack weld nuts to the blades after full tightness.

Note Ensure that the notch engraved on the shaft (outer) end is parallel to the blade. The partition plates and stopper angles are to be inspected for damage, weld cracks or detachment. Replace stoppers if damage or distortion is apparent. Repair weld joint if weld cracks or detachment is observed.

MM-M02 Rev.000 (17.07.13)

The bearings are to be inspected for any damage, rusting or seizure. Defective bearings should be repaired or replaced. Inspect the shaft gland packing, if leakage observed during operation, for any damage or deterioration. Replace deteriorated gland packing with new.

Note Do not over-tighten the packing follower.

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The link rods and link pins are to be inspected for deformation, wear or damage. Defective link rods and link pins should be replaced and secured with split pins. The actuator lever and the link pin are to be checked for wear or damage. Worn or damaged pin and lever should be rectified or replaced. The air cylinder support is to be checked for any weld crack. Any defect noticed should be rectified. After inspection and replacement of defective parts, individual blades are to be checked for full opening and closing positions. Replace the link rod and link pins and then check manual operation of both blades together for the dual damper. Ensure proper closing and opening operation for each blade. Ensure that the actuator is inspected and overhauled by the instrumentation and controls department. Operate and check for full travel and free movement of the power cylinder before connecting the damper. Connect the damper to the actuator, operate the damper locally and confirm that the damper operation is smooth. Set the local position indicator for full open and close positions. Operate the damper from CCR and ensure that each damper position in CCR coincides with the local indicator. Confirm that all four dampers in the same elevation have uniform opening or closing operation.

Guillotine Damper Visually inspect the damper frame and seats for deformation, corrosion or erosion. Repair or replace the defective parts as necessary.

MM-M02 Rev.000 (17.07.13)

Visually inspect the damper blade for any damage, deformation, corrosion or erosion. Perform thickness survey of blades where erosion is apparent. Repair or replace the defective blades as follows: Completely worn blades are to be replaced with new blades. Where the wear is local and the blade thickness is < 6 mm for gas side, perform patch-welding to restore the blade to its original thickness. Inspect the fasteners, which secure the blades to the shaft, for looseness, damage or wear. Damaged, worn and missing fasteners should be replaced and the blades secured properly. The damper is to be inspected for damage, wear or detachment of seal and seal internals and their fixing bolts. Replace seal and Boiler Ducts and Dampers

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Chapter 4 Preventive Maintenance

seal internals and bolts with new if damage or wear is apparent. Replace the canvas of the gaiter if found severely torn off. The damper line shafts are to be inspected for any damage due to pitting, rusting or seizure. Defective line shafts should be rectified or replaced. The pillow block and the bearings are to be inspected for any damage due to pitting, rusting or seizure. Defective pillow block along with bearings should be rectified or replaced. The flexible coupling which coupled line shaft with gearbox and the universal coupling which coupled the actuator with gearbox are to be checked for any loosened coupling bolts and damaged washer. Tighten the loosened coupling bolts immediately on notice. The actuator support, actuator mounting bracket and L-Angle bracket are to be checked for any weld crack. Defects noticed should be rectified. Gearbox connection and actuator connection are to be checked for any loosened bolts and if found any loosened bolts, tighten the loosened bolts immediately with the help of spring washers. After inspection and replacement of defective parts, check that the blade moves freely to the full closing and opening positions. Ensure that the seals are perfectly placed on the seal. Readjust the seals to attain proper seating as per the following procedure: Holding the damper blades in the closed position, inspect the seal clearance with the seat. Loosen the fixing bolts and adjust the seals to obtain maximum contact with the seats. If required tap the seal plates with wooden hammers. Ensure that the actuator is inspected and overhauled by the electrical department. Operate and check for full travel and free movement of the damper. Connect the damper to the actuator, operate the damper locally and confirm that the damper operation is smooth. Set the local position indicator for full open and close positions.

MM-M02 Rev.000 (17.07.13)

Operate the damper from CCR and ensure that the damper position in CCR coincides with the local indicator.

Boiler Ducts and Dampers

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Chapter 4 Preventive Maintenance

TABLE 4-2 No.

Ducts Air and flue gas ducts

Major Check Item

Erosion, corrosion

Check Method

Visual, Thickness survey

Weld cracks Visual, NDE Struts, guide Erosion, weld Visual, NDE vanes, cracks stiffeners Ducts and Accumulation Visual duct of ash hoppers FDF suction Damage and Visual duct and foreign silencer material PAF suction Damage and Visual duct and foreign silencer material Non-metallic Damage, Visual, expansion erosion, Thickness joints corrosion of survey bellows Damage or Visual, NDE weld defect in cover plate Duct Free Visual, NDE supports: movement Fix, sliding Weld cracks and guide supports

Check Reference

Action to be Taken (if beyond acceptable limit)

Thickness within limits

Repair by patch work. Apply anti-corrosive painting after repair

No weld cracks No erosion or weld cracks

Repair weld joint Repair or replace

Remarks

Inspection Date

Inspector

Results

Recommended Minimum thickness (Original Thickness): Air ducts: 3.5mm (5 mm ) Flue gas ducts: 5.5mm (7 mm)

No abnormal Clear accumulated ash accumulation of ash No damage and foreign material on screen No damage and foreign material on screen No damage and thickness within limits

Clear any sticking foreign material

No damage and weld defect

Repair or replace cover plate

Free to slide No weld defect

Replace slide plates Repair weld defect

Clear any sticking foreign material Repair or replace

MM-M02

Rev.000 (17.07.13)

1

Description

ANNUAL OUTAGE MAINTENANCE CHECK LIST

Boiler Ducts and Dampers

4-24

Chapter 4 Preventive Maintenance

Cont’d. from previous page.. TABLE 4-2 No.

Description

Rigid and guide 1 (Cont) stoppers

Major Check Item

Check Method

Deformation, Visual damage

Rigid, spring and Missing or Visual constant load defective hanger supports components

Action to be Taken (if beyond acceptable limit)

No damage

Replace defective components

No missing or defective components

Replace missing or defective components

Readjust hangers. If springs are defective, replace springs.

Free expansion movement

Visual

Expansion as per design values

Packing

Visual

No damaged Replace packing or deteriorated packing

Remarks

Inspection Date

Inspector

Results

Adjust spring hangers COLD position during outage and verify HOT position during operation

MM-M02

Rev.000 (17.07.13)

Access Doors

Check Reference

ANNUAL OUTAGE MAINTENANCE CHECK LIST

Boiler Ducts and Dampers

4-25

Chapter 4 Preventive Maintenance

Cont’d. from previous page.. TABLE 4-2 No.

Major Check Item

Check Method

Check Reference

Action to be Taken (if beyond acceptable limit)

Multi-Louver Damper, Butterfly Damper, Wind Box Damper, Guillotine Damper Frame and Wear, corrosion Visual No abnormal wear, Repair or replace seats and deformation corrosion or deformation Blades Wear, corrosion Visual No abnormal wear, Repair or replace and deformation corrosion or deformation Blade Wear, damage Visual No damaged or Replace securing or looseness loose fasteners or fasteners or pins pins Seal plates Damage, wear Visual No damaged or Replace and secure or detachment loose seal plates properly Bearings

Wear, damage, Visual pitting or seizure Lubrication Visual

Gland packing Link rods and link pins

Damage or Visual deterioration Wear, Visual deformation or damage Wear or damage Visual

Lever and pins Actuator supports

Support beam damage or weld defect

Visual

No wear, damage or pitting Adequate good grease No damaged or deteriorated packing No deformation, wear or damage

Repair or replace defective bearings Clean bearings and apply fresh grease Replace gland packing

No wear or damage

Repair or replace

No damage or weld crack

Repair

Remarks

Inspection Date

Inspector

Results

Adjust seal clearance after replacement

Repair or replace

MM-M02

Rev.000 (17.07.13)

2

Description

ANNUAL OUTAGE MAINTENANCE CHECK LIST

Boiler Ducts and Dampers

4-26

Chapter 4 Preventive Maintenance

Cont’d. from previous page.. TABLE 4-2 No.

Check Method

Check Reference

Action to be Taken (if beyond acceptable limit)

Remarks

Inspection Date

Inspector

Results

3- Way Damper Flap and seat Deformation or Visual damage

No damage

Repair or replace

Bearing

Damage

Visual

No damage

Replace

O-rings

Damage

Visual

No crack or cut

Replace

MM-M02

Rev.000 (17.07.13)

3

Major Check Item

Description

ANNUAL OUTAGE MAINTENANCE CHECK LIST

Boiler Ducts and Dampers

4-27

Chapter 4 Preventive Maintenance

TABLE 4-3 No.

1

Description

Check Method

Check Reference

Action to be Taken (if beyond acceptable limit)

Remarks

Inspection Date

Inspector

Results

Ducts Duct, hopper guide vane, struts, stiffeners

Deformation, damage

Visual

Weld cracks

Visual NDE

No cracks

Repair weld joint

Non-metallic Deformation, expansion joints damage

Visual

No deformation

Repair or Replace

Weld cracks

Visual NDE

No cracks

Repair weld joint

Deformation, damage

Visual

No deformation

Repair or Replace

Weld cracks

Visual NDE

Duct supports Fix, sliding and guide supports Rigid, spring and constant hanger

No deformation

Repair or Replace

No Damage

No Damage

No Damage No cracks

Repair weld joint

Multi-Louver Damper, Butterfly Damper, Wind Box Damper, Guillotine Damper Frame and seats Deformation

Visual

No abnormal wear, corrosion or deformation

Repair or replace

Blades

Visual

No abnormal wear, corrosion or deformation

Repair or replace

Deformation

MM-M02

Rev.000 (17.07.13)

2

Major Check Item

ABNORMAL CONDITION AFTER MAINTENANCE CHECKLIST

Boiler Ducts and Dampers

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Chapter 4 Preventive Maintenance

Cont’d. from previous page.. TABLE 4-3 No.

Descriptio Major Check Item n

2 Blade (Cont) securing fasteners or pins

Damage or looseness

Check Method

Visual

Seal plates

Damage or Visual detachment Link rods Deformation or Visual and link pins damage Lever and Damage Visual pins Actuator Support beam Visual supports damage or weld defect

Check Reference

No damaged or loose fasteners or pins

Action to be Taken (if beyond acceptable limit)

Remarks

Inspection Date

Inspector

Results

Replace

No damaged or Replace and secure loose seal plates properly No deformation, or Repair or replace damage No damage Repair or replace No damage or weld crack

Repair

3- Way Damper Flap and seat Deformation or damage

Visual

No damage

Repair or replace

Bearing

Damage

Visual

No damage

Replace

O-rings

Damage

Visual

No crack or cut

Replace

MM-M02

Rev.000 (17.07.13)

3

ABNORMAL CONDITION AFTER MAINTENANCE CHECKLIST

Boiler Ducts and Dampers

4-29

Chapter 5

Disassembly and Reassembly

Chapter

5 Disassembly and Reassembly Disassembly and reassembly are the activities to be conducted when internal parts of the equipment are required to be accessed. An important part of the activities is the preparatory work. This should identify the manpower, spares and tools that may be required during the maintenance work. A shortfall of any of these may affect the schedule and the operational status of the plant. The major steps associated with disassembly and reassemblies are as follows:

5.1

Disassembly and Reassembly of a Multi-Louver Damper The disassembly and reassembly procedure for a typical Multi-Louver isolation damper is described below. The disassembly and reassembly procedures for the remaining single and double row Multi-Louver control and isolation dampers are similar.

CAUTION Prior to carrying out any maintenance on a Multi-Louver damper, confirm that the boiler and the concerned rotating equipment are shut down and all isolations are in place.

a)

Preparation If a Multi-Louver damper disassembly becomes necessary, all associated equipment is to be mechanically and electrically isolated and an authorized work permit and a valid isolation certificate shall be in place prior to commencement of work.

MM-M02 Rev.000 (17.07.13)

The following points are also to be considered while preparing for disassembly and reassembly. 

Have all necessary drawings (assembly drawings, sectional drawings, part details, etc.) and documents (log sheets, field record book, etc.) ready prior to start of work.



Prepare the necessary handling facilities (e.g. chain blocks, jacks and supports, etc.) to remove and store the various parts.



It is possible that a mobile crane may be required to remove the damper from its installed location for maintenance.

Co-ordinate with the instrumentation and controls department to remove all connected instrumentation before starting disassembly work.

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5-1

Chapter 5

b)

Disassembly and Reassembly

Disassembly

CAUTION When separating joints and flanges, use jacking bolts and wooden mallets. Never apply force with hammers, chisels or screwdrivers.

CAUTION Rigging and transportation of equipment must be carried out by authorized persons. Care is to be taken where equipment weight and center of gravity are to be considered. Utmost care is to be taken to protect machined surfaces.

All data are to be recorded during disassembly. During disassembly, make match marks on adjoining parts for ease of identification at the time of reassembly. The disassembly procedure is as follows: Refer to Figure 2-9. 1

Remove the link pin which connects the drive blade lever arm (14).

CAUTION Do not remove the link pin with steel hammer as the hammered pin edge may flare and make removal difficult. Use wooden mallets or a copper rod to remove the link pin.

Provide suitable support to the pneumatic cylinder and remove the hinge pins securing the pneumatic cylinder to the actuator support. Remove the pneumatic cylinder (6) and transport it to the laydown area for further inspection and maintenance by the instrumentation and controls section.

3

Provide suitable support to the link rod (13) and remove the link pins connecting the blade lever arm (14). Remove the link rod (13) and transport it to the laydown area.

MM-M02 Rev.000 (17.07.13)

2

Boiler Ducts and Dampers

5-2

Chapter 5

Disassembly and Reassembly

CAUTION Do not remove the link pin with steel hammer as the hammered pin edge may flare and make removal difficult. Use wooden mallets or a copper rod to remove the link pin.

4

Loosen the securing bolt and then remove the position indicator plate (18) and the limit switch assembly (16) from the drive blade shaft.

5

Using a suitable withdrawal device or a bearing puller withdraw the drive blade lever arm (14) from the drive shaft (4). Remove and secure the keys from the shaft.

Note Remove the seal plates at this stage from the blades for the applicable dampers fitted with seals. 6

Remove the bearing assembly (7) and sleeve from the drive and stub shafts (4 and 5) from both ends.

Note Provide suitable support to the blade being removed to avoid falling when the bearings are removed. Keep the blades in the open condition to provide supports to the blade that is removed. 7

Remove the pins securing the drive and stub shafts (4 and 5) and the blade (2).

8

Move the blade axially (if required) to facilitate removal of shafts and withdraw the drive and stub shafts (4 and 5) from the blade.

Note Match mark the removed blades and their respective shafts before removal for easy reassembly. 9

Following a similar procedure remove the remaining blades (2).

MM-M02 Rev.000 (17.07.13)

10 To remove the blade (2), use a suitable bearing puller and withdraw the bearing assembly (7) from the drive shaft (4). 11 Remove the seal (3), mating flange gasket (12), mating flange hard wares (11) and mating flange (10) from the blade (2). 12 Loosen the nuts securing the gland packing follower and remove the packing follower from the shaft. 13 Remove the gland packing from the stuffing box (8) located on the frame (1) at the actuator end. Boiler Ducts and Dampers

5-3

Chapter 5

Disassembly and Reassembly

Note Provide suitable support to the drive blade inside the duct to avoid falling when the packing and bearings are removed. 14 Remove the bearing assembly (7), bearing case and sleeve from the stub shaft (5) at the NDE. 15 As performed in Step 8 move the blade axially and remove the drive and stub shafts (4 and 5) from the blade (2).

c)

Reassembly Reassembly is carried out in the reverse sequence of disassembly. Install all parts in the same positions from where they were removed, referring to the match marks and identification numbers. Clean all disassembled components, service them and apply a thin coat of lubricating oil on the shaft at the location of bearings. The reassembly procedure is described below: 1

Insert the drive and stub shafts (4 and 5) into the respective ends of the blade (2) and secure them using pins.

2

Insert the blade and shaft assembly into the frame (1) and support it from the duct using wooden planks.

3

Clean and apply lubricating oil on the stub shaft (5) and insert the sleeve onto the shaft.

4

Install the bearing assembly (7) and the bearing case at the NDE of the stub shaft (5).

Note 1 Do not tighten the bearing case bolts fully as final setting may require small adjustments while aligning the shaft at the opposite end.

Note 2 The wooden supports at the bottom of the blades should be adjusted such that load is not transferred to the NDE shaft.

MM-M02 Rev.000 (17.07.13)

5

Replace new gland packing into the stuffing box (8) at the DE. Insert the packing follower and evenly tighten the nuts just sufficient enough to compress the gland packing.

Note Do not over-tighten the packing follower.

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5-4

Chapter 5

Disassembly and Reassembly

6

Apply a thin coat of lubricating oil on the drive shaft (4), where the bearing assembly (7) will be seated. Ensure that the bearing is inspected and serviced before installation. If the bearing was found to be damaged, it should be replaced.

7

Install the bearing assembly (7) on the drive shaft (4). Sometimes, it may be necessary to pre-heat the bearing in an oil bath before it is installed. Replace the bearing case and grease the bearing sufficiently.

8

Install the seal (3), mating flange gasket (12), mating flange hardware (11) and mating flange (10) on the blade (2).

9

Remove the wooden supports installed to support the blades, before attempting to operate the damper blades. Check the level of blade with a spirit level and perform minor adjustments if required. Tighten the bearing cases at this stage.

10 Rotate the blade back and forth and tighten the gland follower at this stage.

CAUTION Over tightening of the packing will hamper free movement of the damper.

11 Following similar procedure stated in Steps 1~4, install the remaining blades (2). Check operation of the blades for full open and close positions individually.

Note Adjust the seal plates at this stage to obtain maximum contact with the damper seat, wherever applicable. 12 Connect all blades using the link rod (13) and link pins with its turn-buckle arrangement. 13 Assemble the lever arm (14) on the drive shaft (4) using the keys.

MM-M02 Rev.000 (17.07.13)

14 Install and secure the position indicator (18) and limit switch (16) to the drive shaft (4). 15 Replace the pneumatic cylinder (6) and secure it to the support frame using hinge pins. 16 Connect the pneumatic cylinder with the lever arm (14) using link pin. 17 Restore the compressed air to the pneumatic cylinder and check damper operation to the fully open and close positions. Verify these

Boiler Ducts and Dampers

5-5

Chapter 5

Disassembly and Reassembly

positions from inside the duct. If any adjustment is required, use the turn-buckle arrangement to obtain the required conditions. 18 Verify that the position indicator reflects the actual position of the damper blades. Adjust the limit switches, if necessary, to obtain satisfactory results. 19 Restore the removed cabling and operate the damper from CCR and ensure full open and close operations.

MM-M02 Rev.000 (17.07.13)

20 Replace any damaged insulation and restore the damper to regular operation.

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5-6

Chapter 5

5.2

Disassembly and Reassembly

Disassembly and Reassembly of a Butterfly Damper

CAUTION Prior to carrying out any maintenance on a multi-Louver damper, confirm that the boiler and the concerned rotating equipment are shut down and all isolations are in place.

a)

Preparation If a butterfly damper disassembly becomes necessary, all associated equipment is to be mechanically and electrically isolated and an authorized work permit and a valid isolation certificate shall be in place prior to commencement of work. The following points are also to be considered while preparing for disassembly and reassembly.

b)



Have all necessary drawings (assembly drawings, sectional drawings, part details, etc.) and documents (log sheets, field record book, etc.) ready prior to start of work.



Prepare the necessary handling facilities (e.g. chain blocks, jacks and supports, etc.) to remove and store the various parts.



Co-ordinate with I&C and Electrical Department to remove all connected instrumentation and isolate electric power supply before starting disassembly work.

Disassembly

CAUTION When separating joints and flanges, use jacking bolts and wooden mallets. Never apply force with hammers, chisels or screwdrivers.

MM-M02 Rev.000 (17.07.13)

CAUTION Rigging and transportation of equipment must be carried out by authorized persons. Care is to be taken where equipment weight and center of gravity are to be considered. Utmost care is to be taken to protect machined surfaces.

Boiler Ducts and Dampers

5-7

Chapter 5

Disassembly and Reassembly

All data are to be recorded during disassembly. During disassembly, make match marks on adjoining parts for ease of identification during reassembly. The disassembly procedure is as follows: Refer to Figure 2-11. 1

De-Couple the electric actuator (7) and the gear box (6).

CAUTION Do not remove the link pin with steel hammer as the hammered pin edge may flare and make removal difficult. Use wooden mallets or a copper rod to remove the link pin.

2

Provide suitable support to the electric actuator and remove the hinge pins securing the electric-actuator to the actuator support. Remove the electric actuator and transport it to the laydown area for further inspection and maintenance by the instrumentation and controls and electrical sections.

3

Loosen the securing bolt and then remove the position indicator (15) from the drive shaft (4).

4

Using a suitable withdrawal device or a bearing puller withdraw the gear box (6) from the drive shaft (4). Remove and secure the keys from the shaft.

5

Remove the fixing bolts and then remove the seals (3) from the top and bottom ends of the blade.

6

Remove the bearings assembly (11) from the shafts (4 and 5) at both ends.

Note

MM-M02 Rev.000 (17.07.13)

Provide suitable support to the blade being removed to avoid falling when the bearings are removed. Keep the blades in the open condition to provide supports to the blade that is being removed. 7

Loosen the bolts securing the gland packing followers and remove the packing followers from the shafts (4 and 5).

8

Remove the gland packing and the lantern rings from the stuffing boxes (12) located on the frame (1) at both ends.

9

Remove the bolts securing the shafts (4 and 5) to the blade (2) and then remove the shafts.

Boiler Ducts and Dampers

5-8

Chapter 5

c)

Disassembly and Reassembly

Reassembly Reassembly is carried out in the reverse sequence of disassembly. Install all parts in the same positions they were removed from, referring to the match marks and identification numbers. Clean all disassembled components, service them and apply a thin coat of lubricating oil on the shaft at the location of bearings. The reassembly procedure is described below: 1

Locate the blade (2) in the horizontal position and provide support to it from the bottom of the duct using wooden planks.

Note The supports may not have been removed unless any maintenance work was performed on the blade. 2

Insert the shafts (4 and 5) through the frame (1) into the respective locations of the blade (2). Secure the shafts to the blade using bolts.

Note The blade support should be adjusted to locate the shafts concentric to the frame openings. 3

Replace new gland packing and lantern rings into the stuffing boxes (12) at both ends.

4

Install the packing followers and evenly tighten the bolts just sufficient enough to compress the gland packing.

Note Do not over-tighten the packing follower. 5

MM-M02 Rev.000 (17.07.13)

6

Apply a thin coat of lubricating oil on the drive shaft (4), where the bearing assembly (11) will be seated. Ensure that the bearing is inspected and serviced before installation. If the bearing was found to be damaged, it should be replaced. Install the bearing assembly (11) on the drive shaft (4). Replace the bearing case and grease the bearing sufficiently.

7

Following a similar procedure, install the bearing assembly (11) onto the stub shaft (5) at the NDE.

8

Remove the wooden supports before attempting to operate the damper blades. Check the level of blade with a spirit level and perform minor adjustments if required. Tighten the bearing cases at this stage.

9

Rotate the blade back and forth and hand-tighten the packing followers such that the gland packing is slightly compressed.

Boiler Ducts and Dampers

5-9

Chapter 5

Disassembly and Reassembly

CAUTION Over tightening of the packing will lead to seizure of the shaft.

10 Replace the seals (3) and secure them with the fixing bolts. Adjust the seals to have a tight contact with the seal seats. 11 Assemble the gear box (6) on the drive shaft (4) using the keys. 12 Install and secure the position indicator (15) to the drive shaft (4). 13 Replace the electric actuator (7) and secure it to the support frame using hinge pins. 14 Couple the electric actuator (7) with the gear box (6). 15 Restore the electric power supply to electric actuator and check damper operation to the fully open and close positions. Verify these positions from inside the duct. 16 Verify that the position indicator reflects the actual position of the damper blade. Adjust the position indicator, if necessary, to obtain satisfactory results. 17 Restore the removed cabling and operate the damper from CCR and ensure full open and close operations.

MM-M02 Rev.000 (17.07.13)

18 Replace any damaged insulation and restore the damper to regular operation.

Boiler Ducts and Dampers

5-10

Chapter 5

5.3

Disassembly and Reassembly

Disassembly and Reassembly of a 3- Way Damper

CAUTION Prior to carrying out any maintenance on a Multi-Louver damper, confirm that the boiler and the concerned rotating equipment are shut down and all isolations are in place.

a)

Preparation If a 3-way damper disassembly becomes necessary, all associated equipment is to be mechanically isolated and an authorized work permit and a valid isolation certificate shall be in place prior to commencement of work. The following points are also to be considered while preparing for disassembly and reassembly.

b)



Have all necessary drawings (assembly drawings, sectional drawings, part details, etc.) and documents (log sheets, field record book, etc.) ready prior to start of work.



Prepare the necessary handling facilities (e.g. chain blocks, jacks and supports, etc.) to remove and store the various parts of the equipment.



Co-ordinate with instrumentation and controls department and remove all the related instruments before starting the work.

Disassembly

CAUTION When separating joints and flanges use jacking bolts and wooden mallets. Never apply force with hammers, chisels or screwdrivers.

MM-M02 Rev.000 (17.07.13)

CAUTION Rigging and transportation of equipment must be carried out by authorized persons. Care is to be taken where equipment weight and center of gravity are to be considered. Care is to be taken to protect the machined surfaces.

Boiler Ducts and Dampers

5-11

Chapter 5

Disassembly and Reassembly

All data are to be recorded during disassembly. Make match marks on adjoining parts for reference during reassembly. Indicate the direction of flow if this is not marked on the damper body. Refer to Figure 2-12. 1

Using a chain block support the damper in position before removing the bolts from the air inlet and outlet flanges.

2

Lock the inlet and outlet pipes (with permanent supports or temporary locks). Ensure that the pipelines don’t move when the damper flanges are loosened.

3

Ensure that the chain block is loaded and remove the bolts from the counter flange and counter flange hard wares (8 & 9), gasket (10), and outlet spool piece.

4

Lower the damper using the chain-block and move it to a position from where it can be transported to the working area.

5

Locate the damper on timber supports to avoid damage to the machined surface of the flanges.

6

Remove the flange bolts and then remove the outlet side spool piece from the damper frame (1).

7

To remove the blade (2) and the drive shaft (4), proceed as follows:

   

MM-M02 Rev.000 (17.07.13)



Using timber planks or chain block, provide temporary supports to the blade (2). Remove the bearing lock and then remove the bearing (5) from the drive shaft (4) at both ends. Remove the gland box from the bearing base at both ends. Remove the O-rings from the gland boxes. Remove the pins securing the drive shaft and the blade and withdraw the drive shaft from one end of the frame. Lift the blade from the top of the frame for inspection or repair.

8

Inspect the drive shaft for any bend or damage. Install the drive shaft between centers in a lathe and position a Dial test Indicator (Clock Gauge) at the center of the shaft. Set the pointer at zero and rotate the drive shaft one complete turn to check for eccentricity. Minor corrections, if necessary, can be made in the workshop. If the bend is excessive, the drive shaft should be replaced.

9

Inspect the blade and the seal for damage. Minor damages on the blade and the seal can be removed by oilstone. If the surface defects are excessive, machine or replace the blade.

Boiler Ducts and Dampers

5-12

Chapter 5

c)

Disassembly and Reassembly

Reassembly Reassembly is carried out in the reverse sequence to that used for disassembly. Install all the parts in their original place, referring to the match marks. Insert the blade (2) from the top of the frame (1). Support it with temporary supports so as to enable insertion of drive shaft into the boss of the blade.

2

Insert the drive shaft (4) through one end of the frame (1) into the blade (2). Align the holes in the blade and the drive shaft and then insert the pins to secure the drive shaft and the blade.

3

Install O-Rings into the grooves in the gland box and locate the gland boxes into the grooves in the bearing base.

4

Replace the bearing (5) and secure them to the bearing base on either side of the drive shaft.

5

Check the movement of the blade for freedom. If it does not move freely, adjust the bearing alignment as necessary.

6

Install counter flange and counter flange hard wares (8 & 9), and a new gasket (10) and secure the spool piece to the frame using the original bolts and nuts. Tighten the fasteners to the recommended values provided in the torque chart in Appendix A.

7

Using the lifting equipment, transport the damper to its original position. Using new gaskets connect the inlet and outlet pipes to the counter flanges.

8

Using a torque wrench tighten all the bolts and nuts of the counter flanges to ensure leak-proof tightness.

MM-M02 Rev.000 (17.07.13)

1

Boiler Ducts and Dampers

5-13

Chapter 5

5.4

Disassembly and Reassembly

Disassembly and Reassembly of a Wind Box Damper

CAUTION Prior to carrying out any maintenance on a multi-Louver damper, confirm that the boiler and the concerned rotating equipment are shut down and all isolations are in place.

The disassembly and reassembly procedures for a typical dual blade windbox damper are described below. The procedures for the remaining dampers are similar.

a)

Preparation If a wind box damper removal and disassembly becomes necessary, all associated equipment is to be mechanically and electrically isolated and an authorized clearance and work permit shall be in place prior to the commencement of work. The following points are also to be considered when preparing for disassembly and reassembly:

b)



Have all necessary drawings (assembly drawings, sectional drawings, part details, etc.) and documents (log sheets, field record book, etc.) ready prior to start of work.



Prepare the necessary handling facilities (e.g. chain blocks, jacks and supports, etc. to remove and store the various parts of the equipment).



Co-ordinate with the instrumentation and controls Department to remove all the related instrumentation before starting disassembly work.

Disassembly

CAUTION

MM-M02 Rev.000 (17.07.13)

When separating joints and flanges, use jacking bolts and wooden mallets. Never apply force with hammers, chisels or screwdrivers.

All data are to be recorded during disassembly. During disassembly, make match marks on adjoining parts for ease of identification at the time of reassembly. The disassembly procedure is as follows: Refer to Figure 2-13. If it is necessary to remove a drive damper blade or drive shaft, perform the following steps:

Boiler Ducts and Dampers

5-14

Chapter 5

1

Disassembly and Reassembly

Disconnect the pneumatic cylinder and the drive mechanical assembly (13).

CAUTION Do not remove the link pin with steel hammer as the hammered pin edge may flare and make removal difficult. Use wooden mallets or a copper rod to remove the link pin.

2

Remove the pneumatic cylinder and the mounting unit from the support.

3

Remove the drive Mechanical assembly (13) from the shaft (1). Secure the shaft key.

4

Loosen and remove the packing gland bolts and nuts (9) and then remove the packing gland (8) from the bearing assembly (6).

5

Remove the gland packing (7) from the bearing assembly (6).

6

Remove the linkage pins and then remove the link (31) between the drive blade (28) and driven blade (30).

7

With a grinding machine, remove the tack welding between the shaft (1) and the U-bolt (3). Also remove the tack welding between the nuts (4) for the U-bolts and the blade (28).

8

Remove the U-bolts (3) and nuts (4) to release the damper blade (28) from the drive shaft (1).

9

Withdraw the drive blade shaft (1) axially from the damper box (34).

If it is necessary to remove a driven damper blade or shaft, perform the following steps: 10 Remove the welding between the bearing (5) and the damper box (34) and remove the bearing from one end of the damper box. 11 With a grinding machine, remove the tack welding between the shaft (15) and the U-bolt (3). Also remove the tack welding between the nuts (4) for the U-bolts and the driven blade (30).

MM-M02 Rev.000 (17.07.13)

12 Withdraw the driven blade shaft (15) through the opening of the damper box where the bearing was removed.

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5-15

Chapter 5

c)

Disassembly and Reassembly

Reassembly The reassembly procedure is carried out in the reverse sequence to that for disassembly. Install all parts in the same positions they were removed from, referring to the match marks and checking that the clearances are maintained as specified. 1

To reassemble a driven blade or shaft, perform the following steps: i)

Insert the driven blade shaft (15) through the damper box and install it into the bearing (5) at the opposite end.

Note This bearing was not removed during disassembly.

ii)

Secure the driven blade (30) with the driven blade shaft (15) using the U-bolts (3) and nuts (4).

iii) Tack-weld the U-bolt with the shaft (15) and the nut with the blade (30) after full tightening. iv) Replace the removed bearing (5) and weld it to the damper box (34). v)

2

Rotate by hand and ensure the blade and shaft assembly is free to move.

To reassemble a drive blade or shaft, perform the following steps: i)

Insert the drive blade shaft (1) through the bearing assembly (6) and install it into the bearing (5) at the opposite end.

Note The bearing (5) at the opposite end was not removed during disassembly.

ii)

Secure the drive blade (28) with the drive blade shaft (1) using the U-bolts (3) and nuts (4).

iii) Tack-weld the U-bolt with the shaft (1) and the nut with the blade (28) after full tightening.

MM-M02 Rev.000 (17.07.13)

iv) Replace new gland packing (7) into the bearing assembly (6). Replace the packing gland (8) and just hand-tighten it with the bolts and nuts (9).

Note Do not over tighten the packing gland.

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5-16

Chapter 5

v)

Disassembly and Reassembly

Rotate by hand and ensure the blade is free to move.

vi) Move both blades to the fully closed position and then replace the link (31) and connect the drive blade and the driven blades using pins. vii) Replace the drive mechanical assembly (13) using the removed shaft key. viii) Rotate the damper and ensure that both blades move to the fully open position. Replace the mounting unit and place the pneumatic cylinder onto the support.

4

Connect the clevis (17) of the pneumatic cylinder with the drive mechanical assembly (13).

5

Connect instrument air to the pneumatic cylinder and operate the damper locally. Ensure that the damper opens and closes fully.

6

Replace any removed or damaged insulation.

7

Operate the damper from CCR and ensure that it moves uniformly with other dampers in the same elevation.

MM-M02 Rev.000 (17.07.13)

3

Boiler Ducts and Dampers

5-17

Chapter 5

5.5

Disassembly and Reassembly

Disassembly and Reassembly of a Guillotine Damper

CAUTION Prior to carrying out any maintenance on a guillotine damper, confirm that the boiler and the concerned rotating equipment are shut down and all isolations are in place.

a)

Preparation If a guillotine damper disassembly becomes necessary, all associated equipment is to be mechanically and electrically isolated and an authorized work permit and a valid isolation certificate shall be in place prior to commencement of work. The following points are also to be considered while preparing for disassembly and reassembly. 

Have all necessary drawings (assembly drawings, sectional drawings, part details, etc.) and documents (log sheets, field record book, etc.) ready prior to start of work.



Prepare the necessary handling facilities (e.g. chain blocks, jacks and supports, etc.) to remove and store the various parts.



Co-ordinate with I&C and Electrical Department to remove all connected instrumentation and isolate electric power supply before starting disassembly work.

b) Disassembly

CAUTION When separating joints and flanges, use jacking bolts and wooden mallets. Never apply force with hammers, chisels or screwdrivers.

MM-M02 Rev.000 (17.07.13)

CAUTION Rigging and transportation of equipment must be carried out by authorized persons. Care is to be taken where equipment weight and center of gravity are to be considered. Utmost care is to be taken to protect machined surfaces.

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5-18

Chapter 5

Disassembly and Reassembly

All data are to be recorded during disassembly. During disassembly, make match marks on adjoining parts for ease of identification during reassembly. The disassembly procedure is as follows: Refer to Figure 2-15 & 2-16. 1

De-Couple the electric actuator (10) and the gear box (11).

2

Provide suitable support to the electric actuator and remove the actuator mounting bracket (19) and L-Angle bracket (18) securing the electric-actuator to the actuator support. Remove the electric actuator and transport it to the laydown area for further inspection and maintenance by the instrumentation and controls and electrical sections.

3

Loosen the securing bolt and then remove the position indicator from the electric actuator (10).

4

Loosen the flexible coupling bolts and remove the flexible coupling (14) from the gear box (11).

5

De-Couple the drive screws (5) from the gear box (11) in both sides and remove the flexible coupling bolts.

6

Using a suitable withdrawal device or a bearing puller withdraw the gear box (11) from the line shaft (7). Remove and secure the keys from the shaft.

7

Remove the fixing bolts and then remove the seals (3) from the blade.

8

Remove the pillow block bearings (12) from the line shaft (7) at both ends.

Note Provide suitable support to the blade being removed to avoid falling when the bearings are removed. Keep the blades in the open condition to provide supports to the blade that is being removed. 9

Loosen the universal coupling bolts and remove the universal coupling (13) from the line shafts (7).

MM-M02 Rev.000 (17.07.13)

10 Remove the bolts securing the line shafts (7) and then remove the line shafts.

c)

Reassembly Reassembly is carried out in the reverse sequence of disassembly. Install all parts in the same positions they were removed from, referring to the match marks and identification numbers. Clean all disassembled components, service them and apply a thin coat of lubricating oil on the

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5-19

Chapter 5

Disassembly and Reassembly

shaft at the location of bearings. The reassembly procedure is described below: 1

Locate the blade (2) in the horizontal position and provide support to it from the bottom of the duct using wooden planks.

Note The supports may not have been removed unless any maintenance work was performed on the blade. 2

Insert the drive screws (5) into the respective locations. Place the blade along with the frame (1) properly.

Note The blade support should be adjusted to locate the shafts concentric to the frame openings. 3

Replace flexible coupling bolts if found in damaged condition and refit the flexible coupling (14) into the line shaft (7), the gear box (11) and drive screws (5).at both ends.

Note Do not over-tighten the packing follower. 4

Apply a thin coat of lubrication on the line shaft (7) where the pillow block bearings (12) will be seated and also on the drive screws (5). Ensure that the bearing is inspected and serviced before installation. If the bearing was found to be damaged, it should be replaced.

5

Install the pillow block bearings (12) on the line shaft (7) at the DE side. Replace the bearing case and grease the bearing sufficiently.

6

Following a similar procedure, install the pillow block bearings (12) onto the line shaft (7) at the NDE side.

7

Remove the wooden supports before attempting to operate the damper blades. Check the level of blade with a spirit level and perform minor adjustments if required. Tighten the bearing cases at this stage.

8

Rotate the blade back and forth and hand-tighten the packing followers such that the gland packing is slightly compressed.

MM-M02 Rev.000 (17.07.13)

CAUTION Over tightening of the packing will lead to seizure of the shaft.

9

Replace the seals (3), seal internals (4) and secure them with the fixing bolts. Adjust the seals to have a tight contact with the seal seats.

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5-20

Chapter 5

Disassembly and Reassembly

10 Assemble the gear box (11) on the line shaft (7) using the keys. 11 Install and secure the position indicator to the electric actuator (10). 12 Replace the electric actuator (10) and secure it to the support frame using actuator mounting bracket (19) and L-Angle bracket (18). 13 Couple the electric actuator (10) with the gear box (11). 14 Restore the electric power supply to electric actuator and check damper operation to the fully open and close positions. Verify these positions from inside the duct. 15 Verify that the position indicator reflects the actual position of the damper blade. Adjust the position indicator, if necessary, to obtain satisfactory results. 16 Restore the removed cabling and operate the damper from CCR and ensure full open and close operations.

MM-M02 Rev.000 (17.07.13)

17 Replace any damaged insulation and restore the damper to regular operation.

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5-21

Chapter-6

Corrective Maintenance

Chapter

6 C o r r e c t iv e M a in t e n a n c e Corrective maintenance is the repair or replacement work undertaken for sudden failure of any part or component of the equipment. Though a well-planned preventive maintenance program tries to minimize the probability of occurrence of sudden failure of equipment, provision for attending to these unscheduled maintenance requirement is to be made. Corrective maintenance work is to be given priority depending on the seriousness of the problem faced and the impact on plant operations. The schedule for repair of any equipment should be carefully planned to keep outage time to a minimum. During such repair or replacement work, an inspection is to be carefully conducted to determine why the equipment has failed. Good corrective maintenance requires, not only the quick restoration of the failed equipment back into service but also demands every effort to identify and record the root cause of the failure. The inspection results can be of significant help in exploring the exact reason for the failure. The findings, along with possible rectification proposals, are to be used as a feedback to update the preventive maintenance procedures.

6.1

Prerequisites The necessary prerequisites for the corrective maintenance of the ducts and dampers are as follows:

a)

Scheduling Unlike preventive maintenance, scheduling activity only starts after failure of the equipment. Depending on the severity of the problem, the importance of the service provided by the failed equipment and availability of manpower to attend to the problem, a contingency schedule is to be prepared to solve the problem at the earliest opportunity. The schedule should clearly indicate the critical path activity and assign the priority for different parallel activities. Finally, once the schedule is agreed, strict adherence to it is to be maintained to ensure timely completion of the maintenance activity.

b)

Departmental Interface/Notification

MM-M02 Rev.000 (17.07.13)

Refer to Section 4.1.2, Departmental Interface/Notification.

c)

Isolation of Equipment Refer to Section 4.1.3, Isolation of Equipment.

d)

Safety Precautions Refer to Section 4.1.4, Safety Precautions.

Boiler Ducts and Dampers

6-1

Chapter-6

6.2

Corrective Maintenance

Preparation a)

Parts, Tools and Equipment Refer to Subsection 4.2.1 a), Parts, Tools and Equipment.

b)

Documentation Refer to Subsection 4.2.1 b), Documentation.

6.3

Troubleshooting

MM-M02 Rev.000 (17.07.13)

This section provides information about carrying out troubleshooting and servicing for the ducts and the dampers, pertaining to mechanical maintenance staff. Tables of Faults, Possible Causes and Remedies have been provided to assist in troubleshooting by qualified users. If any new kind of problem is encountered which is not listed in the following table, contact the manufacturer for assistance.

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6-2

Chapter-6

TROUBLESHOOTING – DUCTS AND DAMPERS

TABLE 6-1 Fault

Corrective Maintenance

Possible Causes

Remedy

Ducts Non-uniform duct expansion

Faulty supports or stoppers

Check the sliding supports on both sides of the duct and their guides. Correct them as per drawing

Hanger supports not loaded

Tie rods not adjusted correctly

Check the spring loading. Reload the spring by tightening the tie rods and lock them in position

Loose locknuts

Tighten lock nuts properly

Improper movement of duct supports and expansion bellows

Check all supports and expansion bellows for possible constraints and remove them.

Defective welding of stiffeners

Check for loose stiffeners and re-weld them

Loose multi-Louver damper blades

Check for loose blades of multi-Louver damper in adjacent area and rectify during shut down.

Wrong orientation of fan control vane damper at the suction side

Check orientation of control vane damper at the fan suction with respect to the rotation of the fan impeller. Re-erect the control damper correctly as per the installation drawings.

Air or flue gas leakage

Duct punctured due to erosion or defective weld joint

Remove insulation and inspect ducts for holes. Check for erosion during shutdown and rectify by patch welding or replace duct plates.

Leakage through access door

Loose bolts

Tighten access door bolts. Replace the gasket if leakage does not stop.

Deteriorated or damaged gasket

Replace gasket

FD fan suction silencer screen partially blocked

Check for any blockage at the suction screen of FD fan and clear it

Improper operation of blade pitch control

Check for proper operation of the blade pitch control and rectify

Discharge damper not opened fully

Check the damper actuator for its proper functioning. Rectify the defect or replace the actuator.

Punctured duct

Check for holes in the duct and repair the punctured area. Check insulation and replace if needed.

Duct vibration

Inadequate combustion air flow

MM-M02 Rev.000 (17.07.13)

Hot spots on the ducts

Boiler Ducts and Dampers

6-3

Chapter-6

Corrective Maintenance

Cont’d. from previous page.. TROUBLESHOOTING – DUCTS and DAMPERS

TABLE 6-1 Fault

Possible Causes

Remedy

Dampers Damper is stuck

Fouling of moving parts with stationary parts

Inspect and adjust blade clearance, readjust blade stop bolts

Broken or bent linkages

Repair or replace damaged linkages

Seizure of linkage joints and air cylinder hinge joints

Remove, clean and lubricate the linkage and hinge joint pins

Defective bearings

Replace defective bearings

Defective pneumatic cylinder

Repair or replace pneumatic cylinder

Low air pressure

Adjust correct air supply pressure Clean filters Rectify air leakage

Air / flue gas leakage through gland

Wind box damper not fully closing

Internal leakage of damper

Instrument air leakage

Rectify leakage

Faulty solenoid valve

Replace solenoid valve

Mechanical lock not removed

Remove pin from the mechanical lock

Packing damaged or deteriorated

Replace new packing material

Insufficient packing

Provide additional gland packing

Inadequate tightening of gland packing follower

Tighten the gland nuts sufficiently to obtain leak proof gland

Faulty air cylinder operation

Check air cylinder operation and rectify

Inadequate instrument air pressure

Check for instrument air leakage and rectify. Check for blockage of filter regulator and clear blockage

Damaged or distorted blades

Repair or replace damaged blades

Foreign material lodged between blades

Inspect and clear any foreign material during outage

Damaged seals

Adjust seal plates. Replace blade seals and/or damper seats as necessary.

MM-M02 Rev.000 (17.07.13)

External leakage of damper

Damper not closing fully

Repair or replace bent or damaged linkages

Deteriorated or damaged gasket

Replace the gasket

Loose bolts

Tighten the bolts properly

Body leakage

Identify the appropriate location of the leakage and arrest the same with welding.

Boiler Ducts and Dampers

6-4

Chapter-7

Recommended Lubrication

Chapter

7 Recommended Lubrication TABLE 7-1

RECOMMENDED LUBRICATION FOR DAMPERS

Item

Multi Louver Dampers and Duplex Multi Louver Dampers

3-way Damper

Application point

Bearings

Bearings, Steam Threads, Yoke nuts, All other threaded parts of valves.

Recommended lubricants

Silicon grease or High temperature grease

Silicon grease

Alvania Grease No.2 (Shell make)

Mobilux Grease No.2 (Mobil)

Mobilux Grease No.2 (Mobil)

Stem Threads: Castrol MP or Ronex MP,

Alvania Grease No.2 (Shell make)

Yoke Nut: Ronex MP/ Castrol MP Other threaded parts: MOLYKOTE P37 or equivalent Application Method

Hand operated Grease pump / gun

Hand operated Grease pump / gun

Quantity of initial fill

As required

As required

Annually

Annually

Quantity

-

-

Caution

-

-

As required

As required

Quantity

-

-

Caution

-

-

Replacement Frequency

Make-up

MM-M02 Rev.000 (17.07.13)

Frequency

Boiler Ducts and Dampers

7-1

Appendix A

Appendix

A Torque Chart TABLE A-1 Description

TORQUE CHART Quantity

Torque

M12 X 65Lg

2 Nos/gland follower

95 N/m in dry condition

TSF Dampers M16 X 60 Lg

2 Nos/gland follower

240 N/m in dry condition

MLD

Bolt/Stud Size

Remarks

Note: For limit Switch hardwares – Refer Manufacturer’s Catalogue.

MM-M02 Rev.000 (17.07.13)

.

Boiler Ducts and Dampers

A-1

Appendix B

Appendix

B Recommended Spare Parts SL.NO.

1

2

3

MLD

TSF Damper

BFD

Guillotine Damper

SPARES ITEM

QUANTITY

Bearings

1 Set / Damper

Seals

1 Set / Damper

Gland packing

1 Set / Damper

Bearings

1 Set / Damper

Seals

1 Set / Damper

Gland packing

1 Set / Damper

Bearings

1 Set / Damper

Seals

1 Set / Damper

Gland packing

1 Set / Damper

Seals

1 Set / Damper

MM-M02 Rev.000 (17.07.13)

4

PRODUCT

Boiler Ducts and Dampers

B-1

Appendix C

Appendix

C Special Tools

MM-M02 Rev.000 (17.07.13)

NOT RECOMMENDED

Boiler Ducts and Dampers

C-1

Appendix D

Appendix

D Coupling Alignment

MM-M02 Rev.000 (17.07.13)

NOT RECOMMENDED

Boiler Ducts and Dampers

D-1

Appendix E

Appendix

MM-M02 Rev.000 (17.07.13)

E Applicable Vendor Drawings

Boiler Ducts and Dampers

E-1

MM-M02 Rev.000 (17.07.13)

Appendix-E

FIGURE E-1 Boiler Ducts and Dampers

FDF OUTLET DAMPER E-2

MM-M02 Rev.000 (17.07.13)

Appendix-E

FIGURE E-2 Boiler Ducts and Dampers

RAPH OUTLET SECONDARY AIR DAMPER E-3

MM-M02 Rev.000 (17.07.13)

Appendix-E

FIGURE E-3 Boiler Ducts and Dampers

BURNER WINDBOX SECONDARY AIR DAMPER E-4

MM-M02 Rev.000 (17.07.13)

Appendix-E

FIGURE E-4 Boiler Ducts and Dampers

RAPH INLET COLD PRIMARY AIR DAMPER E-5

MM-M02 Rev.000 (17.07.13)

Appendix-E

FIGURE E-5 Boiler Ducts and Dampers

RAPH OUTLET HOT PRIMARY DAMPER E-6

MM-M02 Rev.000 (17.07.13)

Appendix-E

FIGURE E-6 Boiler Ducts and Dampers

PULVERIZER INLET HOT PRIMARY AIR DAMPER E-7

MM-M02 Rev.000 (17.07.13)

Appendix-E

FIGURE E-7 Boiler Ducts and Dampers

PAF OUTLET COLD PRIMARY AIR DAMPER E-8

MM-M02 Rev.000 (17.07.13)

Appendix-E

FIGURE E-8 Boiler Ducts and Dampers

PULVERIZER INLET COLD PRIMARY AIR DAMPER E-9

MM-M02 Rev.000 (17.07.13)

Appendix-E

FIGURE E-9 Boiler Ducts and Dampers

RAPH INLET GAS DAMPER E-10

MM-M02 Rev.000 (17.07.13)

Appendix-E

FIGURE E-10 Boiler Ducts and Dampers

RAPH OUTLET GAS DAMPER E-11

MM-M02 Rev.000 (17.07.13)

Appendix-E

FIGURE E-11 Boiler Ducts and Dampers

IDF OUTLET DAMPER E-12

MM-M02 Rev.000 (17.07.13)

Appendix-E

FIGURE E-12 Boiler Ducts and Dampers

PULVERIZER INLET HOT PRIMARY AIR SHUT-OFF DAMPER E-13

MM-M02 Rev.000 (17.07.13)

Appendix-E

FIGURE E-13 Boiler Ducts and Dampers

PULVERIZER INLET COLD PRIMARY AIR SHUT-OFF DAMPER E-14

MM-M02 Rev.000 (17.07.13)

Appendix-E

FIGURE E-14 Boiler Ducts and Dampers

ESP INLET ISOLATION DAMPER E-15

MM-M02 Rev.000 (17.07.13)

Appendix-E

FIGURE E-15 Boiler Ducts and Dampers

SECONDARY PASS GAS CONTROL DAMPER E-16

MM-M02 Rev.000 (17.07.13)

Appendix-E

FIGURE E-16 Boiler Ducts and Dampers

FLAME DETECTOR COOLING FAN INLET DAMPER E-17