73833830 Design and Fabrication of Portable Pneumatic Fuel Pump

DESIGN AND FABRICATION OF PORTABLE PNEUMATIC FUEL PUMP A PROJECT REPORT Submitted by

PRABHU J

(080212100085)

RAJARAJAN N M

(080212100097)

SARAVANAKUMAR S

(080212100109)

VEERAMANIKANDAN A

(080212100128)

in partial fulfilment for the award of the degree Of

BACHELOR OF ENGINEERING IN MECHANICAL ENGINEERING

DEPARTMENT OF MECHANICAL ENGINEERING

ANNA UNIVERSITY OF TECHNOLOGY COIMBATORE COIMBATORE – 641047 June 2011

ACKNOWLEDGEMENT First and foremost, we thank the Lord almighty for showering his blessings and lifting us in our all endeavours. We wish to express our deep sense of gratitude and heartfelt thanks to the Vice Chancellor Dr. K. Karunakaran, Anna University of Technology Coimbatore, for providing the efficient lab facilities and internet facilities which paved the way for the successful completion of the project. We wish to express our sincere thanks and deep sense of gratitude to the Registrar Cdr. S. Premchand, Anna University of Technology Coimbatore, for providing the necessary facilities along with sound moral support to carry out this project work successfully. We express our deep gratitude towards our respected Dean Academics, Dr. M. Saravanakumar, Anna University of Technology Coimbatore, for his continuous encouragement and support. We would like to thank, Dr. M. Sakthivel, Head of the Department, Mechanical Engineering, for giving his various ideas and suggestions which helped in enhancing the project in efficient way. We would like to express our sincere thankfulness and deep sense of gratitude to our guide Dr. K. Sooryaprakash, Assistant Professor, Department of Mechanical Engineering for giving his full support with encouraging words and mind which helped in completing this project with interest and to learn about various techniques. We would also like to express our sincere thankfulness and deep gratitude to all our beloved faculty of the Department of Mechanical Engineering.

TABLE OF CONTENTS

CHAPTER NO.

1

TITLE

PAGE NO.

ABSTRACT

i

LIST OF TABLES

ii

LIST OF FIGURES

iii

INTRODUCTION 1.1

Project Overview

1

1.2

Company Profile

5

2

LITERATURE REVIEW

6

3

OBJECTIVE

7

4

PROJECT DESCRIPTION

5

4.1

Introduction

8

4.2

Components and Descriptions

13

4.3

Block Diagram

17

4.4

Parts of the Pump

18

4.5

Parts Specifications

23

4.6

Working Principle

27

4.7

Design Calculation

29

4.8

Maintenance

31

4.9

Advantages and Limitations

32

BILL OF MATERIALS

33

6

COST ESTIMATION

7

CONCLUSION AND FUTURE ENHANCEMENTS

8

34

7.1

Conclusion

35

7.2

Future Enhancements

35

REFERENCES

36

ABSTRACT

This project “DESIGN AND FABRICATION OF PORTABLE PNEUMATIC FUEL PUMP” is an outcome of basic instinct to increase the discharge rate and decrease the time of pumping the fuel from storage barrels to the machine or equipment especially industries where machineries are placed in second or third floor. By utilizing simple pneumatic mechanism, fuel can be pumped especially with less power consumption and minimum human labour. When compared to traditional fuel pumping the time taken is also dramatically reduced, as the discharge rate is increased drastically. Added advantage in this is portable and occupies less space. It is ideal for fuel pumping, as no electric field around the fuel pumping area. This project is of great use to companies where pumping of fuel is everyday duty, even this project can be used in ration shops.

LIST OF FIGURES FIGURE NO

TITLE

PAGE NO

4.3.1

BLOCK DIAGRAM OF FUEL PUMP

17

4.4.1

PRESSURE GAUGE

18

4.4.2

AIR HOSE

19

4.4.3

GATE VALVE

21

4.4.4

O RINGS

22

4.5.1

CYLINDER HEAD

23

4.5.2

CYLINDER

24

4.5.3

ONE WAY VALVE

24

4.5.4

SUCTION PIPE

25

4.5.5

ISOMETRIC VIEW OF PNEUMATIC FUEL PUMP

26

4.6.1

FUNCTION CHART

28

LIST OF TABLES TABLE NO

TITLE

PAGE NO

1

BILL OF MATERIALS

33

2

COST ESTIMATION

34

CHAPTER 1 INTRODUCTION 1.1 PROJECT OVERVIEW In the pursuit of excellence, the manufacturing industries are seeking now in a new technology to improve productivity, quality of the product and reduce product cost. The cited subjects are seriously discussed in these days. Most of the manufacturing industries use centrifugal pumps for pumping fuel from barrels to the required location. The discharge rate of centrifugal pump is low. The discharge head has also some limitations which restrict the use of centrifugal pump where high head is required. As a fuel pump, the centrifugal pump is always risky because of electric motor placed just behind the impeller, which may lead to fire accidents. Hence having this in mind, usage of reciprocating pump instead of centrifugal pump looked like the best alternate. Rather than keeping the idea in mind we brought it to reality. We tested the performance of both the pumps. In this work a double acting reciprocating pump is used as fuel pump.

PNEUMATICS The word ‗pneuma‘ comes from Greek and means breather wind. The word pneumatics is the study of air movement and its phenomena is derived from the word pneuma. Today pneumatics is mainly understood to means the application of air as a working medium in industry especially the driving and controlling of machines and equipment. Pneumatics has for some considerable time between used for carrying out the simplest mechanical tasks in more recent times has played a more important role in the development of pneumatic technology for automation. Pneumatic systems operate on a supply of compressed air which must be made available in sufficient quantity and at a pressure to suit the capacity of the system. When the

pneumatic system is being adopted for the first time, however it wills indeed the necessary to deal with the question of compressed air supply. The key part of any facility for supply of compressed air is by means using reciprocating compressor. A compressor is a machine that takes in air, gas at a certain pressure and delivered the air at a high pressure. Compressor capacity is the actual quantity of air compressed and delivered and the volume expressed is that of the air at intake conditions namely at atmosphere pressure and normal ambient temperature. The compressibility of the air was first investigated by Robert Boyle in 1962 and that found that the product of pressure and volume of a particular quantity of gas. The usual written as PV = C

(or) P1V1 = P2V2

In this equation the pressure is the absolute pressured which for free is about 14.7 Psi and is of courage capable of maintaining a column of mercury, nearly 30 inches high in an ordinary barometer. Any gas can be used in pneumatic system but air is the mostly used system now a days.

SELECTION OF PNEUMATICS Mechanization is broadly defined as the replacement of manual effort by mechanical power. Pneumatic is an attractive medium for low cost mechanization particularly for sequential (or) repetitive operations. Many factories and plants already have a compressed air system, which is capable of providing the power (or) energy requirements and the control system (although equally pneumatic control systems may be economic and can be advantageously applied to other forms of power). The main advantage of an all pneumatic system are usually economic and simplicity the latter reducing maintenance to a low level. It can also have outstanding advantages in terms of safety.

PRODUCTION OF COMPRESSED AIR Pneumatic systems operate on a supply of compressed air, which must be made available. In sufficient quantity and at a pressure to suit the capacity of the system. When pneumatic system is being adopted for the first time, however it wills indeed the necessary to deal with the question of compressed air supply.

The key part of any facility for supply of

compressed air is by means using reciprocating compressor. A compressor is a machine that takes in air, gas at a certain pressure and delivered the air at a high pressure.

Compressor capacity is the actual quantity of air compressed and delivered and the volume expressed is that of the air at intake conditions namely at atmosphere pressure and normal ambient temperature. Clean condition of the suction air is one of the factors, which decides the life of a compressor. Warm and moist suction air will result in increased precipitation of condense from the compressed air. Compressor may be classified in two general types. 1. Positive displacement compressor. 2. Turbo compressor Positive displacement compressors are most frequently employed for compressed air plant and have proved highly successful and supply air for pneumatic control application. The types of positive compressor 1. Reciprocating type compressor 2. Rotary type compressor

Turbo compressors are employed where large capacity of air required at low discharge pressures. They cannot attain pressure necessary for pneumatic control application unless built in multistage designs and are seldom encountered in pneumatic service.

ROTARY TYPE COMPRESSORS

Rotary screw compressors use two meshing helical screws, known as rotors, to compress the gas. In a dry running rotary screw compressor, timing gears ensure that the male and female rotors maintain precise alignment. In an oil-flooded rotary screw compressor, lubricating oil bridges the space between the rotors, both providing a hydraulic seal and transferring mechanical energy between the driving and driven rotor. Gas enters at the suction side and moves through the threads as the screws rotate. The meshing rotors force the gas through the compressor, and the gas exits at the end of the screws. RECIPROCATING COMPRESSORS

Built for either stationary (or) portable service the reciprocating compressor is by far the most common type. Reciprocating compressors lap be had is sizes from the smallest capacities to deliver more than 500 m³/ min. In single stage compressor, the air pressure may be of 6 bar machines discharge of pressure is up to 15 bars. Discharge pressure in the range of 250 bars can be obtained with high pressure reciprocating compressors that of three & four stages. Single stage and 1200 stage models are particularly suitable for pneumatic applications, with preference going to the two stage design as soon as the discharge pressure exceeds 6 bar, because it in capable of matching the performance of single stage machine at lower costs per driving powers in the range.

1.2 COMPANY PROFILE

NAME

:

PERFECT POLY COATS

ADDRESS

:

S.F No. 408 / 1C, PRICOL PLANT I, Ramakrishna nagar, Jothipuram Post Coimbatore - 641047

NATURE OF WORK :

Painting automobile components

M/S. Perfect poly coats is the painting shop where most of the PRICOL manufactured components like clusters, speedometer consoles etc., are painted. This is the only painting shop which runs under PRICOL. It supplies products to the companies like Toyota, Ashok Leyland, TVS, Yamaha, Mahindra & Mahindra etc.,

CHAPTER 2 LITERATURE REVIEW The following solutions are drawn by referring various national and international journals in context with the existing problem definition.



According to European Patent EP0398209 (Reciprocating oil pump), an existing idea was identified. It works on a reciprocating pump providing oil for low pressure, self-contained oil-filled cables. The pressure head we required for our work was yet higher than the existing patent and large changes are needed on the outlet valve arrangements.



An international journal titled ―Design and Experimental Analyses of Smallflow High-head centrifugal-vortex Pump for Gas-Liquid Two-phase Mixture‖ proposed an idea relevant to the current issue, but portability could not be achieved. Also, centrifugal pumps are operated by electrical means but in our system pneumatic source should only be used.



Based on an international journal titled ―Analysis of gear pumps used to pump high density oils‖, the idea of using a gear pump for our work was revived. This idea was aborted due to insufficient discharge rate and high cost of the equipment.



With reference to a United States Patent 6685443 (Pneumatic reciprocating pump) the idea of using a pneumatically actuated pump was considered. Hence the pump needed electrical source after actuation, the idea was ignored.



Based on a United States Patent 5158439 (Pneumatic pumping device) which proposed an idea about a pneumatic pump for pumping acids, this pump can be used but the density of operating fluid i.e, Diesel was much higher.

CHAPTER 3 OBJECTIVE The primary objective of our work is to set up a pumping arrangement to pump diesel for a heating oven in a painting shop. Diesel is used as the fuel for the oven and hence it has to be pumped to an overhead storage tank from barrels at the ground level. The main concerns involved were 

The pump should be fire proof in order to avoid any fire accidents. The internal atmosphere of the painting shop contains a considerable amount of highly inflammable substances like thinner vapours.



The pump must be portable. There are four overhead tanks where the fuel has to be pumped separately.



Electric motors cannot be used as the driving source due to the increased risk of fire accidents.



It was better to use pneumatic source as the primary source of power. It was the highly available source in the paint shop as it was used throughout the painting process for spraying and drying procedures.

Thus through our search for a suitable way satisfying all the above concerns we decided to work on this project which we found simple and economical.

CHAPTER 4 PROJECT DESCRIPTION 4.1 INTRODUCTION Positive displacement pumps A positive displacement pump causes a fluid to move by trapping a fixed amount of it then forcing (displacing) that trapped volume into the discharge pipe. A positive displacement pump has an expanding cavity on the suction side and a decreasing cavity on the discharge side. Liquid flows into the pump as the cavity on the suction side expands and the liquid flows out of the discharge as the cavity collapses. The volume is constant given each cycle of operation. Positive displacement rotary pumps are pumps that move fluid using the principles of rotation. The vacuum created by the rotation of the pump captures and draws in the liquid. Rotary pumps are very efficient because they naturally remove air from the lines, eliminating the need to bleed the air from the lines manually. Positive displacement rotary pumps also have their weaknesses. Because of the nature of the pump, the clearance between the rotating pump and the outer edge must be very close, requiring that the pumps rotate at a slow, steady speed. If rotary pumps are operated at high speeds, the fluids will cause erosion. Rotary pumps that experience such erosion eventually show signs of enlarged clearances, which allow liquid to slip through and reduce the efficiency of the pump. Positive displacement rotary pumps can be grouped into three main types. Gear pumps are the simplest type of rotary pumps, consisting of two gears laid out side-by-side with their teeth enmeshed. The gears turn away from each other, creating a current that traps fluid between the teeth on the gears and the outer casing, eventually releasing the fluid on the discharge side of the pump as the teeth mesh and go around again. Many small teeth maintain a constant flow of fluid, while fewer, larger teeth create a tendency for the pump to discharge fluids in short, pulsing gushes. Screw pumps are a more complicated type of rotary pumps, featuring two or three screws with opposing thread —- that is, one screw turns clockwise, and the other counterclockwise. The screws are each mounted on shafts that run parallel to each other; the shafts also have gears on them that mesh with each other in order to turn the shafts together

and keep everything in place. The turning of the screws, and consequently the shafts to which they are mounted, draws the fluid through the pump. As with other forms of rotary pumps, the clearance between moving parts and the pump's casing is minimal. Moving vane pumps are the third type of rotary pumps, consisting of a cylindrical rotor encased in a similarly shaped housing. As the rotor turns, the vanes trap fluid between the rotor and the casing, drawing the fluid through the pump. Reciprocating - type Positive displacement pumps have an expanding cavity on the suction side and a decreasing cavity on the discharge side. Liquid flows into the pumps as the cavity on the suction side expands and the liquid flows out of the discharge as the cavity collapses. The volume is constant given each cycle of operation. The positive displacement pumps can be divided into two main classes 

Reciprocating



Rotary

The positive displacement principle applies to the following pumps. They are, 

Rotary lobe pump



Progressive cavity pump



Rotary gear pump



Piston pump



Diaphragm pump



Screw pump



Gear pump



Hydraulic pump



Vane pump



Regenerative (peripheral) pump



Peristaltic pump

Positive displacement pumps, unlike centrifugal or roto-dynamic pumps, will produce the same flow at a given speed (RPM) no matter what the discharge pressure. Positive displacement pumps are "constant flow machines"

A positive displacement pump must not be operated against a closed valve on the discharge side of the pump because it has no shut-off head like centrifugal pumps. A positive displacement pump operating against a closed discharge valve, will continue to produce flow until the pressure in the discharge line are increased until the line bursts or the pump is severely damaged – or both. A relief or safety valve on the discharge side of the positive displacement pump is therefore necessary. The relief valve can be internal or external. The pump manufacturer normally has the option to supply internal relief or safety valves. The internal valve should in general only be used as a safety precaution, an external relief valve installed in the discharge line with a return line back to the suction line or supply tank is recommended. Reciprocating pumps Typical reciprocating pumps are 

Plunger pumps



Diaphragm pumps

A plunger pump consists of a cylinder with a reciprocating plunger in it. The suction and discharge valves are mounted in the head of the cylinder. In the suction stroke the plunger retracts and the suction valves open causing suction of fluid into the cylinder. In the forward stroke the plunger pushes the liquid out of the discharge valve. With only one cylinder the fluid flow varies between maximum flow when the plunger moves through the middle positions, and zero flow when the plunger is at the end positions. A lot of energy is wasted when the fluid is accelerated in the piping system. Vibration and "water hammer" may be a serious problem. In general the problems are compensated for by using two or more cylinders not working in phase with each other. In diaphragm pumps, the plunger pressurizes hydraulic oil which is used to flex a diaphragm in the pumping cylinder. Diaphragm valves are used to pump hazardous and toxic fluids. An example of the piston displacement pump is the common hand soap pump.

Gear pump This uses two meshed gears rotating in a closely fitted casing. Fluid is pumped around the outer periphery by being trapped in the tooth spaces. It does not travel back on the meshed part, since the teeth mesh closely in the centre. Widely used on car engine oil pumps. it is also used in various hydraulic power packs.. Progressing cavity pump Widely used for pumping difficult materials such as sewage sludge contaminated with large particles, this pump consists of a helical shaped rotor, about ten times as long as its width. This can be visualized as a central core of diameter x, with typically a curved spiral wound around of thickness half x, although of course in reality it is made from one casting. This shaft fits inside a heavy duty rubber sleeve, of wall thickness typically x also. As the shaft rotates, fluid is gradually forced up the rubber sleeve. Such pumps can develop very high pressure at quite low volumes. Roots-type pumps The low pulsation rate and gentle performance of this Roots-type positive displacement pump is achieved due to a combination of its two 90° helical twisted rotors, and a triangular shaped sealing line configuration, both at the point of suction and at the point of discharge. This design produces a continuous and non-vorticuless flow with equal volume. Some applications are: 

High capacity industrial air compressors



Roots Type Superchargers on internal combustion engines.



A brand of civil defense siren, the Federal Signal Corporation's Thunderbolt.

Peristaltic pump A peristaltic pump is a type of positive displacement pump used for pumping a variety of fluids. The fluid is contained within a flexible tube fitted inside a circular pump casing (though linear peristaltic pumps have been made). A rotor with a number of "rollers", "shoes" or "wipers" attached to the external circumference compresses the flexible tube. As the rotor turns, the part of the tube under compression closes (or "occludes") thus forcing the fluid to be pumped to move through the tube. Additionally, as the tube opens to its natural state after

the passing of the cam ("restitution") fluid flow is induced to the pump. This process is called peristalsis and is used in many biological systems such as the gastrointestinal tract. Reciprocating-type pumps Reciprocating pumps are those which cause the fluid to move using one or more oscillating pistons, plungers or membranes (diaphragms). Reciprocating-type pumps require a system of suction and discharge valves to ensure that the fluid moves in a positive direction. Pumps in this category range from having "simplex" one cylinder, to in some cases "quad" four cylinders or more. Most reciprocatingtype pumps are "duplex" (two) or "triplex" (three) cylinder. Furthermore, they can be either "single acting" independent suction and discharge strokes or "double acting" suction and discharge in both directions. The pumps can be powered by air, steam or through a belt drive from an engine or motor. This type of pump was used extensively in the early days of steam propulsion (19th century) as boiler feed water pumps. Reciprocating pumps are now typically used for pumping highly viscous fluids including concrete and heavy oils, and special applications demanding low flow rates against high resistance.

Compressed-air-powered double-diaphragm pumps One modern application of positive displacement diaphragm pumps is compressedair-powered double-diaphragm pumps. Run on compressed air these pumps are intrinsically safe by design, although all manufacturers offer ATEX certified models to comply with industry regulation. Commonly seen in all areas of industry from shipping to processing, Graco, SandPiper, Wilden Pumps or ARO are generally the larger of the brands. They are relatively inexpensive and can be used for almost any duty from pumping water out of bunds, to pumping hydrochloric acid from secure storage (dependent on how the pump is manufactured – elastomers / body construction). Lift is normally limited to roughly 6m although heads can reach almost 200 Psi.

4.2 COMPONENTS AND DESCRIPTION PNEUMATIC CONTROL COMPONENT Pneumatically controlling valves are valves that control the flow of pressurized air. Another medium such as water (hydraulics) or electricity, for example, may be used to control the valves. Pneumatic cylinder

Pneumatic cylinders (sometimes known as air cylinders) are mechanical devices which utilize the power of compressed gas to produce a force in a reciprocating linear motion. Like hydraulic cylinders, pneumatic cylinders use the stored potential energy of a fluid, in this case compressed air, and convert it into kinetic energy as the air expands in an attempt to reach atmospheric pressure. This air expansion forces a piston to move in the desired direction. The piston is a disc or cylinder, and the piston rod transfers the force it develops to the object to be moved. Engineers prefer to use pneumatics sometime because they are quieter, cleaner, and do not require large amounts or space for fluid storage. An air cylinder is an operative device in which the state input energy of compressed air i.e. pneumatic power is converted in to mechanical output power, by reducing the pressure of the air to that of the atmosphere.

Single acting cylinder Single acting cylinder is only capable of performing an operating medium in only one direction. Single acting cylinders equipped with one inlet for the operating air pressure, can be production in several fundamentally different designs. Single cylinders develop power in one direction only. Therefore no heavy control equipment should be attached to them, which requires to be moved on the piston return stoke single action cylinder requires only about half the air volume consumed by a double acting for one operating cycle.

Double acting cylinders: A double acting cylinder is employed in control systems with the full pneumatic cushioning and it is essential when the cylinder itself is required to retard heavy messes. This can only be done at the end positions of the piston stock. In all intermediate position a separate externally mounted cushioning derive most be provided with the damping feature. The normal escape of air is out off by a cushioning piston before the end of the stock is required. As a result the sit in the cushioning chamber is again compressed since it cannot escape but slowly according to the setting made on reverses. The air freely enters the cylinder and the piston stokes in the other direction at full force and velocity.

Parts of Pneumatic Cylinder Piston A piston is

a

component

of reciprocating

engines,

reciprocating pumps, gas

compressors and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. In a pump, the function is reversed and force is transferred from the crankshaft to the piston for the purpose of compressing or ejecting the fluid in the cylinder. In some engines, the piston also acts as a valve by covering and uncovering ports in the cylinder wall. In other words, the piston can be defined as a cylindrical member of certain length which reciprocates inside the cylinder. The diameter of the piston is slightly less than that of the cylinder bore diameter and it is fitted to the top of the piston rod. It is one of the important parts which convert the pressure energy into mechanical power. The piston is equipped with a ring suitably proportioned and it is relatively soft rubber which is capable of providing good sealing with low friction at the operating pressure. The purpose of piston is to provide means of conveying the pressure of air inside the cylinder to the piston of the oil cylinder.

Generally piston is made up of  Aluminium alloy-light and medium work.  Brass or bronze or CI-Heavy duty.

The piston is double acting type. The piston moves forward when the high-pressure air is turned from the right side of cylinder. The piston moves backward when high pressure acts on the piston from the left side of the cylinder. The piston should be as strong and rigid as possible. The efficiency and economy of the machine primarily depends on the working of the piston. It must operate in the cylinder with a minimum of friction and should be able to withstand the high compressor force developed in the cylinder and also the shock load during operation. The piston should posses the following qualities. a. The movement of the piston not creates much noise. b. It should be frictionless. c. It should withstand high pressure.

Piston Rod The piston rod is circular in cross section. It connects piston with piston of other cylinder. The piston rod is made of mild steel ground and polished. A high finish is essential on the outer rod surface to minimize wear on the rod seals. The piston rod is connected to the piston by mechanical fastening. The piston and the piston rod can be separated if necessary. One end of the piston rod is connected to the bottom of the piston. The other end of the piston rod is connected to the other piston rod by means of coupling. The piston transmits the working force to the oil cylinder through the piston rod. The piston rod is designed to withstand the high compressive force. It should avoid bending and withstand shock loads caused by the cutting force. The piston moves inside the rod seal fixed in the bottom cover plate of the cylinder. The sealing arrangements prevent the leakage of air from the bottom of the cylinder while the rod reciprocates through it.

Cylinder Cover Plates The cylinder should be enclosed to get the applied pressure from the compressor and act on the pinion. The cylinder is thus closed by the cover plates on both the ends such that there is no leakage of air. An inlet port is provided on the top cover plate and an outlet ports on the bottom cover plate. There is also a hole drilled for the movement of the piston.

Cylinder Mounting Plates: It is attached to the cylinder cover plates and also to the carriage with the help of ‗L‘ bends and bolts.

Control valve: Various types of control valves are used to regulate, control and monitor the air energy for control of direction pressure, flow, etc. Pneumatic energy is regulated and controlled by pneumatic valves. Functionally valves are divided into four major groups.  Direction Control  Flow Control

Solenoid is another name for an electromagnet. Direction control valves are very often actuated by electromagnets. An electromagnet is a temporary magnet. A magnetic force is developed in an electromagnet when electrical current passes through it and force drops down as soon as it is de energized. This electromagnet is commonly termed as solenoid.

The proper working of a

solenoid operated valve depends on the reliability of the electromagnets. It ensures  Quick and sure action  Long life.  Easy maintenance.  Less wastage of energy.

4.3 BLOCK DIAGRAM

AIR ADJUSTMENT SCREW AIR INLET PISTION ARRANGEMENT

FUEL DELIVERY ONE WAY VALVE

SUCTION PIPE

PRE FILTER Fig. 4.3.1 Fuel Pump The block diagram, as shown in the fig 4.3.1, shows the arrangement of the portable pneumatic pump. This model is the actual output of this study.

4.4 PARTS OF THE FUEL PUMP The following are the parts of the fuel pump,  Pressure gauge  Air adjustment screw  Cylinder  Suction pipe  Filter  Air hose  Locknut  Grease nipple  ¼ inch gate valve  O Rings  Cylinder head  Tube couplers

Pressure gauge

Fig 4.4.1 pressure gauge Instruments used to measure pressure are called pressure gauges or vacuum gauges shown in the fig 4.4.1. A manometer could also be referring to a pressure measuring instrument, usually limited to measuring pressures near to atmospheric. The term manometer is often used to refer specifically to liquid column hydrostatic instruments. A vacuum gauge

is used to measure the pressure in a vacuum—which is further divided into two subcategories, high and low vacuum (and sometimes ultra-high vacuum). The applicable pressure range of many of the techniques used to measure vacuums has an overlap.

Filter A pneumatic filter is a device which removes contaminants from a compressed air stream. This can be done using a number of different techniques, from using a "media" type that traps particulates, but allows air to pass through to a venturi, to a membrane that only allows air to pass through. Air hose Air hose is shown in the fig 4.4.2. Air hoses are used in underwater diving, such as scuba diving, to carry air from the surface or from air tanks or diving pumps to the diver. Air hoses are therefore a necessary part of standard diving dress and any type of surface supplied diving equipment. They are an essential part of scuba diving equipment, used to deliver pressurised air from the first stage of a diving regulator to the other components.

Fig 4.4.2 Air hose Air hoses are used between locomotives and railroad cars for their brakes, and are also used between those tractors and semi-trailers which use air brakes.

Locknut A locknut, also known as a lock nut, locking nut, prevailing torque nut, stiff nut or elastic stop nut, is a nut that resists loosening under vibrations and torque. Elastic stop nuts and prevailing torque nuts are of the particular type where some portion of the nut deforms elastically to provide a locking action.

Grease fitting A grease fitting, grease nipple, Zerk fitting, or Alemite fitting is a metal fitting used in mechanical systems to feed lubricants, usually lubricating grease, under moderate to high pressure, into a bearing using a grease gun. The fitting is permanently installed by a threaded connection, leaving a nipple connection that the grease gun attaches to. The pressure supplied by the grease gun forces a small captive bearing ball in the nipple to move back against the force of its retaining spring. The arrangement is thus essentially a valve that opens under pressure to allow lubricant to pass through a channel and be forced into the voids of the bearing. When the pressure ceases, the ball returns to its closed position. The ball excludes dirt intrusion and functions as a check valve to prevent grease escaping back out of the nipple. The ball is almost flush with the surface of the nipple so it can be wiped clean to reduce the amount of debris carried with the grease into the bearing. The convex shape of the fitting allows the concave tip of the grease gun to seal against the nipple easily from many angles, yet with a sufficiently tight seal to force the pressured greased to move the ball and enter the fitting, rather than simply oozing past this temporary annular (ring-shaped) seal. Grease nipples are commonly made from zinc-plated steel, stainless steel, or brass. Gate valve A gate valve, also known as a sluice valve, is a valve that opens by lifting a round or rectangular gate/wedge out of the path of the fluid as shown in the fig 4.4.2. The distinct feature of a gate valve is the sealing surfaces between the gate and seats are planar, so gate valves are often used when a straight-line flow of fluid and minimum restric-tion is desired. The gate faces can form a wedge shape or they can be parallel. Typical gate valves should never be used for regulating flow, unless they are specifically designed for that purpose. On

opening the gate valve, the flow path is enlarged in a highly nonlinear manner with respect to percent of opening. This means that flow rate does not change evenly with stem travel. Also, a partially open gate disk tends to vibrate from the fluid flow. Most of the flow change occurs near shutoff with a relatively high fluid velocity causing disk and seat wear and eventual leakage if used to regulate flow. Typical gate valves are designed to be fully opened or closed. When fully open, the typical gate valve has no obstruction in the flow path, resulting in very low friction loss.

Fig 4.4.3 Gate valve

O Rings An O-ring, also known as a packing, or a toric joint, is a mechanical gasket in the shape of a torus; it is a loop of elastomer with a disc-shaped cross-section, designed to be seated in a groove and compressed during assembly between two or more parts, creating a seal at the interface as shown in the fig 4.4.4. The O-ring may be used in static applications or in dynamic applications where there is relative motion between the parts and the O-ring. Dynamic examples include rotating pump shafts and hydraulic cylinder pistons. O-rings are one of the most common seals used in machine design because they are inexpensive, easy to make, reliable, and have simple mounting requirements.

Fig 4.4.4 O rings

4.5 PARTS SPECIFICATION CYLINDER HEAD LENGTH

:

60 mm

DIAMETER :

70 mm

MATERIAL :

Aluminium die casting

DESCRIPTION

:

It is an aluminium cast block having one inlet, outlet and relief valve. It is placed above the cylinder

Fig. 4.5.1. Cylinder Head DOUBLE ACTING CYLINDER LENGTH

:

140 mm

DIAMETER :

85 mm

MATERIAL :

Galvanized iron

DESCRIPTION

:

The double acting cylinder is made up of galvanised iron. It is fitted just above the pump head

Fig.4.5.2 Cylinder ONE WAY VALVE LENGTH

:

52 mm

DIAMETER :

48 mm

MATERIAL :

Mild steel

DESCRIPTION

:

It is made up of cast iron used to connect the suction pipe and piston cylinder. Internal thread is provided for fastening.

Fig.4.5.3. One Way Valve

SUCTION PIPE LENGTH

:

888 mm

DIAMETER :

27 mm

MATERIAL :

Galvanised iron

DESCRIPTION

:

It is made up of galvanised iron material. V – Notch is provided at the end of the suction pipe for effective suction.

Fig.4.5.4. Suction Pipe PRESSURE GAUGE RANGE

:

1 – 10 bar

DESCRIPTION

:

It is used monitor the operating pressure. It is directly connected to the inlet pipe just after the compressor

FILTER LENGTH

:

30 mm

MATERIAL

:

Iron filter (Copper coated)

DESCRIPTION

:

It is cone shaped which helps to filter the fuel from foreign materials, debris and dusts. It is fitted in the end of the suction pipe.

AIR HOSE LENGTH

:

3000 mm

DIAMETER :

8 mm

MATERIAL :

Nylon

DESCRIPTION

:

It is used to connect the compressor to the pump inlet

The isometric view of the portable pneumatic pump is shown in the fig 4.5.5.

Fig.4.5.5 Isometric View of pneumatic fuel pump

4.6 WORKING PRINCIPLE Initially starting with air compresses, its function is to compress air from a low inlet pressure (usually atmospheric) to a higher pressure level. This is an accomplished by reducing the volume of the air. Air compressors are generally positive displacement units and are either of the reciprocating piston type or the rotary screw or rotary vane types. The air compressor used here is a typically small sized, two-stage compressor unit. It also consists of a compressed air tank, electric rotor and pulley drive, pressure controls and instruments for quick hook up and use. The compressor is driver by a 10HP motor and designed to operate in 145 – 175 PSI range. If the pressure exceeds the designed pressure of the receiver a release value provided releases the excesses air and thus stays a head of any hazards to take place. The stored air from compressor is passed through an air fitter where the compressed air is filtered from the fine dust particles. However, before the suction of air into compressor a filter process take place, but not sufficient to operate in the circuit here the filter is used. Then having a pressure regulator where the desired pressure to the operated is set. Here a variable pressure regulator is adopted. Through a variety of direction control value are available, a hand operated solenoid Valve with control unit is applied. The solenoid valve used here is 5 ports, 3 positions. There are two exhaust ports, two outlet ports and one inlet port. In two extreme positions only the directions can be changed while the Centro ore is a neutral position and no physical changes are incurred. The 2 outlet ports are connected to an actuator (Cylinder). The pneumatic activates is a double acting, single rod cylinder. The cylinder output is coupled to further purpose. The piston end has an air horning effect to prevent sudden thrust at extreme ends.

COMPRESSOR AIR

PUMP HEAD

DOUBLE ACTING CYLINDER

PISTON

ONE WAY VALVE

FUEL OUT

SUCTION PIPE

FUEL FROM BARREL Fig. 4.6.1. Function Chart The function chart, shown in the fig 4.6.1 shows the working of the pump. The compressed air from the compressor is passed into the pump head which moves the double acting cylinder. This makes the other side of the piston to suck fuel from suction valve and send it to the outlet valve. PRINCIPLE:  The compressed air from the compressor reaches the solenoid valve. The solenoid valve changes the direction of flow according to the signals from the timing device.  The compressed air pass through the solenoid valve and it is admitted into the front end of the cylinder block. The air pushes the piston for the cutting stroke. At the end of the cutting stroke air from the solenoid valve reaches the rear end of the cylinder

block. The pressure remains the same but the area is less due to the presence of piston rod. This exerts greater pressure on the piston, pushing it at a faster rate thus enabling faster return stroke.  The non-return valve is fixed to the hydraulic cylinders two side (Four numbers).  The stroke length of the piston can be changed by making suitable adjustment in the timer.

4.7 DESIGN CALCULATION Single acting reciprocating pump Diameter = 85 mm = 0.085 m Length = 100 mm = 0.1 m Area The area of the cylinder, A=( =(

)* d2 )*(0.0852)

= 5.674*10-3 m2

Theoretical Volume/stroke The volume of the cylinder, V = A*L m3 = 5.674*10-3*0.1 =5.674*10-4 m3 Number of delivery One stroke/sec = N/60

N = 60 rpm Theoretical Discharge Qt The theoretical discharge of the pump is, Qt =A*L*N/60 =(5.674*10-3*0.1*60)/60 =5.674*10-4 m3 s-1 = 5.674*10-4*1000 = 0.5674 litre/sec = 0.5674*3600 = 2042.82 litre/hour Calculation Verification The output of the pump is then verified by practical method. The results are given below, 10 Sec = 5 litre 1 min = 30 litre 1 sec = 0.5 litre. Thus the values are calculated with reference to standard formulae and the theoretical design values are calculated above. The actual output of the pump is also noted by experiments.

4.8 MAINTENANCE Maintenance It is the activity carried to increase the life and performance of the pumps. Types of Maintenance 1. Preventive maintenance 2. Breakdown maintenance 3. Schedule maintenance Preventive maintenance It is carried out regularly say every day, before and after the pump is operated. Breakdown maintenance It is done only after the pump stops working completely. Schedule maintenance It is carried in routine as per the schedule. It is carried out periodically.

The following are the maintenance which are done in order to avoid breakdown of the pump, 

Lubrication



Periodic inspection



Adjustment of parts



Cleaning



Periodic overhauling



Repair and replacement

4.9 ADVANTAGES AND LIMITATIONS

4.9.1 ADVANTAGES Even if all the other pumps are similar in use the Pneumatic water pump is more advantageous than the other pumps. 1. This is of compact in size 2. Less Maintenance is enough 3. The oil or water pumped is of higher pressure 4. Quite running and smooth operation is achieved. 5. Higher efficiency 6. Full efficient positive displacement pump 7. Effective working principle 8. It does not have any Prime mover, like electric motor related to the unit. 9. As the air is freely available, we can utilize the air to pumping the water and hence it is economical. 10. Less Maintenance

4.9.2 LIMITATIONS 1. It is costlier than the other types of pump because of compressor unit. 2. Less efficiency when compressed to other device. 3. Leakage of air affects the working of the unit.

CHAPTER 5 BILL OF MATERIALS S.NO

PARTS

MATERIALS

1

PRESSURE GAUGE

STEEL PLATE

1

2

AIR ADJUSTMENT SCREW

MILD STEEL

1

3

PISTON

MILD STEEL

1

4

CYLINDER

GALVANISED IRON

1

5

SUCTION PIPE

GALVANISED IRON

1

6

FILTER

IRON FILTER

1

7

PISTON ROD

MILD STEEL

1

8

HOSE

NYLON

2

9

GREASE NIBBLE

ALUMINIUM CASTING

1

10

GATE VALVE

GALVANISED IRON

1

11

CONNECTING PIN

BRASS

1

12

ONE WAY VALVE

MILD STEEL

2

13

ORINGS

RUBBER

3

14

TUBE COUPLER

MILD STEEL

1

15

LOCK NUT

BRASS

1

Table 2. Bill of Materials

QUANTITY

CHAPTER 6 COST ESTIMATION S.NO

NAME OF THE EQUIPMENT

NO OF QUANTITY

COST in (Rupees)

1

PRESSURE GAUGE

1

250

2

AIR ADJUSTMENT SCREW

1

150

3

PISTON

1

1500

4

CYLINDER

1

350

5

SUCTION PIPE

1

375

6

FILTER

1

150

7

PISTON ROD

1

125

8

HOSE

2

225

9

LOCK NUT

1

50

10

GREASE NIPPLE

1

350

11

¼ INCH GATE VALVE

1

240

12

OUTLET HOSE

1

90

13

CONNECTING PIN

1

75

14

BALLS AND ONE WAY VALVE

2

450

15

ORINGS

3

125

16

CYLINDER HEAD

1

1225

17

TUBE COUPLING

1

30

18

SPOOL VALVE

1

500

TOTAL

Table 3. Cost Estimation

6250

CHAPTER 7 CONCLUSION & FUTURE ENHANCEMENTS 7.1 CONCLUSION In this pneumatic fuel pump variable speeds can be obtained by adjusting the pressure of the compressed air. Since the mechanism is so simple and versatile it can be handled by any operator, construction of the unit is very simple. Handling the machine is easy and smooth operation is achieved. This pump also provides fire proof pumping. This increases fuel discharge and reduces human effort & operating time. The main feature of this pump is, it is portable.

7.2 FUTURE ENHANCEMENTS  In this pump, an accumulator can be attached. This attachment of accumulator provides constant discharge.  The diameter of the outlet pipe can be decreased to increase the head.

REFERENCES

 Antonio Esposito - Fluid power with application. Prentice hall of India private limited, 1980.  Bolton,W., - Pneumatic and hydraulic systems, Butterworth-Heinemann, Jordan Hill, Oxford,1997.  Catalogue of Janatics pneumatic product, Janatics Private Limited Coimbatore.  Design data book – compiled by Faculty of Mechanical Engineering, P.S.G. college of technology, Coimbatore  Festo Didactic KG – Fundamentals of control technology, Esslingen-1998.  Festo Pneumatic Catlogue - Festo Pvt Ltd. – Bangalore.

 Werner Deppert/Kurt Stoll., Cutting Cost With Pneumatics, Vogel Buchverlag Wurzburg, 1998.