Burners Czaplinski 2006

Burners - Influence of flame and flame shape on the refractory lining Alain Czaplinski

WHAT IS COMBUSTION ?

A CHEMICAL REACTION BETWEEN TWO CHEMICAL COMPONENTS WHICH CREATES HEAT TYPICALLY ONE OF THE COMPONENT IS AIR ( OXYDISING REACTION ), THE SECOND IS CALLED FUEL

GEORG ERNST STAHL ( 1660 – 1734 ) : COMBUSTION WAS DUE TO THE “PHLOGISTIC COMPONENT” IN COAL IN ORDER TO CALCINATE METAL COAL ( INCLUDING PHLOGISTIC ) => COAL + PHLOGISTIC => FIRE METAL + PHLOGISTIC => CALCINED METAL

IN 1760, BLACK IDENTIFIED “ FIXED AIR “ WHICH IS CO2 IN 1766, CAVENDISH IDENTIFIED “ INFLAMMABLE AIR “ WHICH IS H2 PRIESTLEY IDENTIFIED “PHLOGISTIC AIR “ WHICH IS N2 IN NOVEMBER 1772, LAVOISIER ESTABLISHED THE MASS CONSERVATION PRINCIPLE DURING TIN CALCINATION BY WEIGHTING THE AIR BEFORE AND AFTER THE REACTION

COMBUSTION IS NOT … CALCINATION : CaCO3 + HEAT ( 1800kJ/kg ) => Ca0 + CO2 BY EXTENSION, CALCINATION MEANS TO BURN AT HIGH TEMPERATURE A MATERIAL IN ORDER TO GET A NEW ONE PYROLYSIS : CHEMICAL DECOMPOSITION DUE TO HEAT

COMBUSTION REACTIONS C+0

=> CO + 111 kJ/mol

CO + 0 => CO2 + 283 kJ/mol C + 02 => CO2 + 394 kJ/mol

H2 + 0 => H20 + 242 kJ/mol S + 02 => S02 + 71 kJ/mol CH4 + 202 => CO2 + 2H20 + 820 kJ/mol

CALORIFIC HEAT VALUE HEATING VALUE : MEANS THE HEAT QUANTITY OBTAINED WHEN BURNING ONE UNIT OF FUEL IT IS THE HEAT POTENTIAL OF A FUEL WHICH CAN BE COMPARED WITH OTHERS

HIGH HEATING VALUE ( HHV ) : WATER IS CONSIDERED AS LIQUID (CONDENSATE ) LOW HEATING VALUE ( LHV ) : WATER IS CONSIDERED AS VAPOR HHV and LHV are expressed in kJ/kg HHV = LHV + WATER VAPORISATION HEAT

IN PRACTICE, IN ATMOSPHERIC CONDITIONS, WE NEED TO CONSIDER THE LHV AS FLUE GAS TEMPERATURE IS HIGHER THAN 100°c

RELATION BETWEEN HHV AND LHV HHV = LHV + WATER LATENT VAPORISATION HEAT HHV = LHV + ( %H20 ) x 25 + ( % H ) x 226 % PERCENTAGES IN WEIGHT

IE : HEAVY FUEL OIL LHV = 40100kJ/kg , H20 = 0,95% , H = 11% HHV = 40100 + (0,95)x25 + ( 11)x226 = 40100 + 24 +2486 = 42610 kJ/kg 6% difference IE : NATURAL GAS LHV = 36500 kJ/Nm3 , H20 = 0% , H = 18% HHV = 36500 + (0)x25 + ( 18)x226 = 36500 + 4068 = 40568 kJ/Nm3 11% difference

MAIN NOBLE FUEL CLASSIFICATION PER LHV NATURAL GAZ : 34 000 to 45 000 kJ/Nm3 ( depends on N2 content ) HEAVY FUEL OIL : 40 000 kJ/kg DIESEL OIL

: 43 000 kJ/kg

COAL : ANTHRACITE ( raw basis ) : up to 39 000 kJ/kg STEAM COAL ( raw basis ) : 24 000 kJ/kg to 27 000 kJ/kg LIGNITE ( raw basis ) : 15 000 kJ/kg to 19 000 kJ/kg PETCOKE

( raw basis ) 33 000 kJ/kg to 36 500 kJ/kg

ALTERNATIVE FUELS : TYPICAL LHV VALUES

•* Contaminated water * Blast furnace gaz * Dried sewage

negative 2 700 kJ/kg 8 000 to 15 000 kJ/kg

* Paper, cardboard

13 000 to 17 000 kJ/kg

* tyres

25 000 to 31 000 kJ/kg

* solvents

29 000 to 37 000 kJ/kg

* waste oils

27 000 to 40 000 kJ/kg

* Waste plastics

18 000 to 42 000 kJ/kg

ALTERNATIVE FUELS : WHY IN A CEMENT PLANT ? IN EUROPEAN COMMUNITY, CITY WASTES NEEDS FOR INCINERATION : A RESIDENCE TIME SUPERIOR TO 2 SECOND AT 850°c

IN A ROTARY KILN : RESIDENCE TIME IS SEVERAL SECONDS BETWEEN 900°c AND 1300 °c

A ROTARY KILN IS A PERFECT INCINERATOR WHERE ASHES ARE REUSED

DEFINITIONS ABOUT AIR

STOECHIOMETRIC AIR : EXACT AIR QUANTITY REQUIRED TO BURN ONE UNIT OF FUEL ( kg of air/ kg of fuel ) EXCESS AIR LAMBDA : AVAILABLE AIR QUANTITY / STOECHIOMETRIC AIR LAMBDA > 1 : REAL AIR EXCESS TO ALLOW A COMPLETE COMBUSTION LAMBDA +/- 1200c H2

=> 1430c

CH4 = > 1957c C2H4 =>

1560c

C3H8 = > 1980c C4H10 = > 1970c STEAM COAL = > +/- 2000c

COAL ANALYSIS %

PROXIMATE ANALYSIS

MOISTURE ASH VOLATILE MATTER FIXED CARBON

TOTAL

7.0 18.0 10.0 65.0

ULTIMATE ANALYSIS 68.00 H 2.20 S 0.80 N 1.00 O 3.00 H20 7.0 ASH 18.0

100.0

C

100,0

Moisture : difference in weight after drying at 105/110°c Volatile matter : difference in weight after pyrolysis at 900°c ( ISO ) or 950°c ( ASTM ) Ashes : remaining weight after complete combustion Fixed carbon : calculated by difference

COAL ANALYSIS PROXIMATE ANALYSIS ON DIFFERENT BASIS raw basis Moisture 7.0 Ash 18.0 Volatile Matter 10.0 Fixed Carbon 65.0 HHV ( Kj/Kg )

26,0

Total

100.0

as dried 1,0 19,16 10,65 69,19 27,68 100,0

dry

ash and moisture free 0.0 0,0 19,36 0,0 10,75 13,33 69,89 86,67 27,96 100,0

34,61 100,0

% in weight HHV is proportional to H20 and ashes, LHV to be calculated from HHV, H20 and H FOR SOLID FUEL, BASIS OF HEATING VALUE SHOULD BE ALWAYS MENTIONED

KEY POINT : IGNITION OF COAL •IGNITION MECHANISM OF COAL RELIES ON VOLATILE MATTER : PYROLYSIS AND COMBUSTION OF VOLATILE MATTER => HEATING UP OF AIR AND SOLID FUEL AT BURNER OUTLET QUANTITY AND QUALITY OF VOLATILE MATTERS ARE THE KEY FACTORS FOR IGNITION SIMPLE CRITERIA : IGNITION BASED ON VOLATILE MATTER CONTENT MORE INTERESTING CRITERIA IGNITION BASED ON QUALITY OF VOLATILE MATTER HHV COAL = HHV FIXED CARBON + HHV VOLATILE MATTER Calculations made on moisture and ash free basis IN CEMENT, WE INTRODUCED COAL WHEN TEMPERATURE IS AROUND 800c , WE AVOID THE IGNITION PROBLEMS

COAL REACTIVITY : % VOLATILE MATTER RELEASED VS TEMPERATURE

COAL REACTIVITY : COMBUSTION RATE OF CHAR ( AT 700c + AIR )

IGNITION OF ANTHRACITE COMPARED TO STEAM COAL ANTHRACITE OF VIET NAM

Temperature (°C)

1500

1000

500

0

STEAM COAL

1500

1000

500

0

0,00

1,00

2,00

3,00

4,00

5,00

6,00

7,00

COAL CLASSIFICATION (ASTM D388) VM/MAF FC/MAF %

0 2

100 98

8

92

14

86

LOW REACTIVITY Anthracite

Low vol. Bit. 22

78

HIGH REACTIVITY

Medium

.

vol. bit 31

69

High vol. A bit.

60

High vol. B bit.

High vol. C bit. or Subbit A

Subbit B

Subbit C

Lignite

40 8890

7780 7220

6110

5280

4610

kCal/kg

HHV WITH INHERENT MOISTURE WITHOUT MINERAL MATTER

SPECIFICITIES OF COMBUSTION IN CEMENT KILNS

ONE SINGLE BURNER ONE VERY LONG AND NARROW FURNACE ( L/D : 10 to 40 ) DIRECT HEAT EXCHANGE WITH CLINKER ( RADIATIONS, CONVECTION ) FUELS ASHES ARE INCORPORATED IN CLINKER ONLY 10% OF COMBUSTION AIR THOUGH THE BURNER EXTREMELY HOT SECONDARY AIR ( 700 TO 1200c ) COMBUSTION EFFICIENCY IS USELY NOT A CRITERIA STABLE LOAD LARGE MIXING OF FUELS

SPECIFICITIES OF COMBUSTION IN CEMENT KILNS ONE SINGLE BURNER ONE VERY LONG AND NARROW FURNACE ( L/D : 10 to 40 ) BURNER OUTPUT : UP TO 250 MW ( 5000 tpd, 4,2MJ/kg ) => equivalent to 21tph of Heavy Fuel oil PRECALCINER KILN : 12 000 tph, 40%/60%, 3MJ/kg clinker => main burner output is 166MW => precalciner output is 250 MW

POWER GENERATION : TANGENTIAL FIRING

FIRING SYSTEM TANGENTIAL WINDBOW BURNERS

DOUBLE ARCH FIRING CALLED W FLAME

TYPICAL ARCH COAL BURNER

BURNER ARRANGEMENT ON THE ARCH

SPECIFICITIES OF COMBUSTION IN CEMENT KILNS ONE SINGLE BURNER BURNER OUTPUT : UP TO 250 MW ( 5000 tpd, 4,2MJ/kg ) => equivalent to 21tph of Heavy Fuel oil PRECALCINER KILN : 12 000 tph, 40%/60%, 3MJ/kg clinker => main burner output is 166MW => precalciner output is 250 MW

A KILN BURNER IS SINGLE : RELIABILITY IS A KEY FACTOR VERY FEW BURNER MANUFACTURERS ON THE WORLD MARKET

SPECIFICITIES OF COMBUSTION IN CEMENT KILNS ONE VERY LONG AND NARROW FURNACE ( L/D : 10 to 40 ) THE FLAME SHAPE IS A KEY ISSUE TO FIT INSIDE THE NARROW TUNNEL THE TEMPERATURE PROFILE IS THE MOST IMPORTANT PARAMETER FOR A CEMENT OR LIME PRODUCER PREMIUM CRITERIA IS : FLAME SHAPE FLEXIBILITY

MULTICHANNELS BURNERS ARE USED IN ROTARY KILNS

MULTI CHANNEL BURNERS : PRINCIPLES THE THREE CHANNEL BURNER TYPE : SWIRL AIR AXIAL AIR AXIAL AIR (ANNULUS) COAL STREAM A

TEMPERATURE PROFILE (CFD Modelling) • p.a. nozzle setting

35° angle

short, hot flame

• p.a. nozzle setting

fully axial

controlled long flame

Unitherm Cemcon Firing Systems

TEMPERATURE PROFIL :

"long" flame

T

"short" flame

FOR CEMENT PRODUCERS : BURNER EFFICIENCY IS TO CONTROL THE FLAME TEMPERATURE ALONG THE KILN

FLAME TEMPERATURE : FLAME WITH LIGNITE AND WASTES

FLAME TEMPERATURE : LIGNITE AND WASTES FIRING

MAIN MULTICHANNEL BURNER MANUFACTURERS COMBUSTION COMPANIES : PILLARD : THREE CHANNELS BURNER, ROTAFLAM UNITHERM : UNIGO, UNIGRESS, UNIGAS, MAS GRECO ENFIL CEMENT ENGINEERING COMPANIES : FLS : SWIRLAX, CENTRAX AND

DUOFLEX

KHD :

PYROJET

UNITHERM MAS BURNER

ONE STABILISER IN THE CENTER ONE SINGLE AIR CHANNEL ADJUSTABLE AIR ANGLE DEVICE ONE 250mbar PA FAN SOLID and WASTES IN THE CENTER

SWIRL SETTING DEVICE FOR PRIMARY AIR

Unitherm Cemcon Firing Systems

PILLARD ROTAFLAM BURNER

ONE STABILISER IN THE CENTER TWO AIR CHANNELS ADJUSTABLE AIR CROSS SECTIONS ONE 250mbar PA FAN SOLID and WASTES IN THE CENTER

PILLARD ROTAFLAM : ADJUSTMENT OF AIR CROSS SECTIONS

FLS DUOFLEX BURNER ONE STABILISER IN THE CENTER TWO AIR CHANNELS MIXED BEFORE BURNER OUTLET ADJUSTABLE AIR CROSS SECTIONS ONE 250mbar PA FAN SOLID and WASTES IN THE CENTER

FLS DUOFLEX BURNER : AIR CROSS SECTIONS ADJUSTMENTS

KHD : PYROJET BURNERS Jet Air Nozzle Ring

NO STABILISER IN THE CENTER COAL CHANNEL BETWEEN TWO AIR CHANNELS FIXED CROSS SECTIONS ONE BLOWER FOR AXIAL AIR 450mbar ONE FAN FOR RADIAL AIR

GRECO ENFIL BURNERS NO FIXED CONCEPT, NO BRAND NAME CASE BY CASE STUDY FIXED CROSS SECTIONS COAL CHANNEL BETWEEN TWO AIR CHANNELS ONE ROOT BLOWER FOR AIR AT 450mbar WASTES IN THE CENTER

SPECIFICITIES OF COMBUSTION IN CEMENT KILNS DIRECT HEAT EXCHANGE WITH CLINKER ( RADIATIONS..)

THE FLAME NEEDS TO BE RADIANT TO IMPROVE THE HEAT EXCHANGE EFFICIENCY RADIATIONS : HEAT EXCHANGE VIA ELECTROMAGNETIC WAVES ( PHOTONS )

RADIANT HEAT FLUX IS PROPORTIONAL TO : T 4

THE FLAME NEEDS HIGH TEMPERATURE AND HIGH INTERNAL MIXING ( NATURAL GAS IS LESS EFFICIENT )

SPECIFICITIES OF COMBUSTION IN CEMENT KILNS

FUELS ASHES ARE INCORPORATED IN CLINKER IN POWER GENERATION, FLY AND BOTTOM ASHES ARE RECOVERED, BUT REUSING IS VERY DIFFICULT

IN CEMENT KILNS, REUSING IS EASY AS IT IS A PART OF THE FINAL PRODUCT WHICI IS REAL SPECIFIC TO THIS INDUSTRY IT MAY CREATE LIMITATIONS ( P2O5 , Cl etc ) WHEN FIRING WASTES

SPECIFICITIES OF COMBUSTION IN CEMENT KILNS ONLY 10% OF COMBUSTION AIR THOUGH THE BURNER EXTREMELY HOT SECONDARY AIR ( 700 TO 1200c ) PRIMARY AIR IS AMBIANT ( LOW TEMPERATURE ): HIGH %PA = LOW EFFICIENCY LOW PRIMARY AIR REDUCES ALSO NOx EMISSIONS LOW PA BURNERS WERE CALLED “HIGH EFFICIENCY BURNERS “

HIGH SPEED PRIMARY AIR IS MIXED WITH LOW SPEED SECONDARY AIR MIXING IS SOMETIMES DIFFICULT, POSITION OF THE BURNER INSIDE THE KILN SHOULD BE ADJUSTABLE

SECONDARY AIR INJECTION AT BURNER TIP

Secondary Air Mixing Flow pattern velocity in [m/s] (velocities above 25 m/s are displayed in red) Unitherm Cemcon Firing Systems

SPECIFICITIES OF COMBUSTION IN CEMENT KILNS COMBUSTION EFFICIENCY IS USELY NOT A CRITERIA FOR BURNERS MANUFACTURERS : BURNER EFFICIENCY IS THE COMBUSTION RATE USUALLY WITH A RIGHT EXCESS AIR AT KILN OUTLET ( 2% O2 ) IS ENOUGH FOR A COMPLETE COMBUSTION AS RESIDENCE TIME IS LONG ENOUGH WITH WASTE FUELS ( SOLID ) , IT MIGHT BE NECESSARY TO INCREASE THE EXCESS AIR

RELATIONS BETWEEN BRICKS AND BURNER AFTER 7 DAYS OF OPERATION

RELATIONS BETWEEN BRICKS AND BURNER AFTER 7 DAYS OF OPERATION

NOTHING TO DO WITH THE BRICKS

NOTHING TO DO WITH BURNER DESIGN

BUT A MISTAKE IN BURNER OPERATION

USUAL IGNITION PROCESS : 1) GAZ IGNITOR WITH ELECTRODES 2) LIQUID OR GAZ LANCE 3) SOLID FUEL INJECTION WHEN TEMPERATURE IS OK 4) CHANGE OF ROTATION SPEED 5) MEAL INJECTION

HEATING UP : RISK WITH POOR FUEL OIL PULVERISATION (1)

HEATING UP OF THE KILN WITH HEAVY FUEL OIL (2)

HEATING UP OF THE KILN WITH HEAVY FUEL OIL (3)

NEW LINING AFTER 8 HOURS HEATING UP TO 1000c

RELATION BETWEEN FLAME INTENSITY AND CLINKER INFLUENCING FACTORS : CEMENT PRODUCERS ARE FOCUSING ON : CLINKER PARAMETERS: BURNABILITY INDEX SILICA RATIO FREE LIME GRINDABILITY S02 , ALKALI RECIRCULATIONS etc..

BURNER MANUFACTURERS ARE FOCUSING ON : DIAMETER AND LENGTH OF KILN TYPE OF PROCESS FUELS TO BE BURNT KILN THERMAL LOAD IN BURNING ZONE

KILN THERMAL LOAD IN BURNING ZONE Q2 /S : HEAT INPUT THROUGH MAIN BURNER DIVIDED BY THE KILN SECTION ( INSIDE BRICKS ) : CALCULATED WITH : SPECIFIC HEAT CONSUMPTION IN kcal/kg KILN OUTPUT KILN DIAMETER Example : KILN : 2300 TPD, Diameter 4,6m , precalciner kiln SPECIFIC HEAT CONSUMPTION : 880 kcal/kg with 65% through the main burner bricks : B620/B320 Q2 /S = 0,65*(( 2300/24)*880*4)/ ( (4,6-0,44)2*π ) Q2 /S = 4033 Gcal/hm2

KILN THERMAL LOAD IMPACT ON LOWER TRANSITION ZONE BRICKS ONE TENTATIVE OF APPROACH BY CALCULATIONS : FLS KILN, 5000 TPD, PRECALCINER, DIAMETER 4,75M FIRST OPERATION KILN 1 : AT 5000 TPD : Q2 / S = 3,8 Gcal/hm2 LTZ : AG 85 0,4 TO 9M , STABLE COATING FROM 12 to 19M => LIFETIME : 14 MONTHS SECOND OPERATION KILN 1 : RUNNING AT 6000 TPD, Q2 / S = 4,5 Gcal/hm2 LTZ : AG 85 BETWEEN 0,4 TO 9M, STABLE COATING FROM 9 to 19M => LIFETIME : 14 MONTHS ( still running )

CONCLUSION : Q2 / S < 4,5 Gcal/hm2 => NO REAL IMPACT ON BRICK LIFETIME ( in this case )

KILN THERMAL LOAD IN BURNING ZONE POLYSIUS KILN WITH PREHEATER , 1800 TPD, DIAMETER 4,6M FIRST TYPE OF CLINKER : Q2 / S = 4,9 Gcal/hm2 SECOND TYPE OF CLINKER, Q2 / S = 5,4 Gcal/hm2 AG AF BETWEEN 7 TO 16M, stable coating starting from 12/14M LTZ LIFE TIME : 6 months with relative stable coating LIFE TIME : 3 months with 2 weeks operation without coating CONCLUSION : Q2 / S > 5,3 Gcal/hm2 BECOMES CRITICAL WITHOUT COATING

KILN THERMAL LOAD IN BURNING ZONE COMPARISON BETWEEN THE KILNS IN Gcal/hm2 :

Q2 / S < 4

: LOW TO NORMAL THERMAL LOAD

4 < Q2 / S < 4, 5 : NORMAL THERMAL LOAD 4,5 < Q2 / S < 5,3 : HIGH THERMAL LOAD Q2 / S > 5,3 : HIGH TO EXTREME HIGH THERMAL LOAD

Gcal m2 ⋅ h

specific heat average load in the sintering zone kiln efficiency

8000 7000

kiln efficiency with precalciner

6000 5000

5

4000 3000

4

2000

3

1000

tpd 1950

1960

1970

1980

KILN THERMAL LOAD EVOLUTION

1990

KILN THERMAL LOAD IN BURNING ZONE IN BELGIUM : 1640tpd, POLYSIUS PREHEATER KILN , Q2 / S = 3,8 Gcal/hm2 4600tpd, POLYSIUS PRECALCINER, Q2 / S = 4,3 Gcal/hm2 Same fuels , bricks B322/B622 on both kilns According to the production manager: “ the flame is stronger on kiln 3 than on kiln 4 “ Life time of bricks in LTZ : Kiln 3 : RG 85/ RG AF = 9 months hot spots Kiln 4 : AG AF = 12 months ( remaining thickness 150 to 200mm ) THERMAL LOAD IS ONE CALCULATED PARAMETER,

BUT FLAME CONTROL IS A NON QUANTIFIED PARAMETER WHICH IS MORE CRITICAL

GAZ FLAME : WITHOUT CONTROL

BURNER IMPULSE , FLAME MOMENTUM , FLAME INTENSITY : IMAGE OF FLAME HARDNESS BE CAREFUL, THERE ARE DIFFERENT WAYS OF CALCULATION (with or without fuels streams ) : FORMULA USED BY LAFARGE, PILLARD ETC.. AXIAL FLAME MOMENTUM : IT IS THE FORCE OF THE AIR STREAMS IN THE KILN AXIS

Gx = Gxa + Gxr = (Qma× Va ) + (Qmr× Vxr ) (N )

(N )

(N )

(m / s)

( kg / s )

( kg / s )

(m / s)

SPECIFIC FLAME MOMENTUM

Gx = Gxa+ Gxr = (Qma× Va ) + (Qmr× Vr ) (N )

(N)

IS ( N / Gcal )

(N)

= Gx/

( kg / s )

(m / s)

( kg / s )

(m / s)

/ P P I S = Gx ( N ) ( Gcal / hr )

/ Gcal ) ) ( N ) ( Gcal( N/ hr

SPECIFIC FLAME MOMENTUM WITH THE SAME WAY OF CALCULATIONS MUST BE USED FOR COMPARISONS

SWIRL NUMBER : ROTATION INSIDE THE FLAME BE CAREFUL, THERE ARE DIFFERENT WAYS OF CALCULATION : FORMULA USED BY LAFARGE, PILLARD ETC..

2(re3 − ri3 ) rg = 3(re3 − ri3 )

Gt × rg SN = De × Gx Gt = Gxr× tgα (N )

Radial air momentum : taking into account the radial air angle

(N )

2(Qma + Qmr ) De = (π × ρm × Gx)

2(re 3 − ri 3 ) rg = 3(re 3 − ri 3 )

IS ( N / Gcal)

De is the orifice diameter through which can pass a = Gx/ gaseous P flow Qv with a momentum of GX ( N ) ( Gcal / hr )

rg : gyration radius of swirl channel

TYPICAL VALUES LOW NOx GENERATION BURNERS : LOW PRIMARY AIR BURNERS SPECIFIC AXIAL AIR MOMENTUM SWIRL PRIMARY AIR PERCENTAGE

: 3 to 5 N / MW : 0,4 to 0,5 : 4 to 8%

HIGH IMPULSE BURNER : SHORT FLAME BURNERS SPECIFIC AXIAL AIR MOMENTUM SWIRL PRIMARY AIR PERCENTAGE

: 8 to 12 N / MW : 0,1 to 0,2 : 8 to 12%

Gx = Gxa+ Gxr = (Qma× Va ) + (Qmr× Vr ) (N )

(N )

(N )

( kg / s )

(m / s)

( kg / s )

(m / s)

PROBLEMS WITH HIGH IMPULSE BURNERS FOR BRICKS WITH HIGH IMPULSE LOW OR IMPULSE BURNERS : THE THEORITICAL THERMAL LOAD IN THE BURNING SECTION ( Q2 / S ) REMAINS THE SAME BUT THE HEAT TRANSFER PROCESS IS DIFFERENT IE THE TEMPERATURE PROFIL IS DIFFERENT THE PROBLEM FOR BURNER MANUFACTURERS WAS TO COMPACT THE FLAME VOLUME : IN THE PAST, THE FLAME WAS LONG AND SHARP OR SHORT AND LARGE BURNER MANUFACTURERS HAD TO WORK ON NEW DETAILED DESIGNS Gx = Gxa+ Gxr( = × Va ) + (QmrPRINCIPLES × Vr ) ) BY(Qma KEEPING OPERATING (N ) (N ) (N ) ( m / s ) ( kg / s ) ( kg / s ) ( m / s ) FOR FIRING PETCOKE AND ALTERNATIVE FUELS THEY SHOULD CALLED THEM “MAS AF”, “PYROJET AF”, “ROTAFLAM AF” etc..

HOLCIM IN SWITZERLAND : CHANGE OF FLAME LENGTH SINTERING ZONE, FLAME SHAPE WITH LOW IMPULSE BURNER

~23 m Flame

! ! WITH HIGH IMPULSE BURNER

~16 m Flame

!☺!

HIGH IMPULSE BURNER : IMPACT ON SINTERING ZONES BRICKS STABLE COATING IS THE BEST PROTECTION OF THE BRICKS IN SINTERING ZONE WITH HIGH IMPULSE BURNERS, THE SINTERING ZONE IS SHORTENED WHICH MAY CREATE PROBLEMS IN THE SELECTION OF BRICKS IN THIS ZONE 5000 TPD ( 4,75 * 74,2m ), FLS PRECALCINER KILNS WITH HIGH IMPULSE DUOFLEX BURNER AT THE DESIGN STAGE THE FOLLOWING SELECTION WAS MADE WITH FLS : 0 to 0,4M : KRONEX 85 0,4 to 9M : ALMAG 85 9 to 29M : REFRAMAG 85 29 to 41M : ALMAG 85

SINCE COMMISSSIONING, STABLE COATING ENDS AT 19/20M LIFE TIME OF RG 85 BETWEEN 19 TO 29M : 7 TO 9 MONTHS REPLACED WITH ALMAG 85 : LIFE TIME 1 YEAR ( running at 6000 tpd )

LAVA LIKE COATING : OVERHEATING

PROBLEM OF RAW MATERIAL PREPARATION ( IRON ORE ..) PROBLEM OF BURNER ADJUSTMENT : LOCAL WEAR : ORIENTATION OF BURNER FOR SOME METERS : HEAT INPUT IS TOO HIGH

COMBUSTION : IMPACT ON UPPER TRANSITION ZONE AND UPSTREAM BRICKS MAIN IMPACT, AS THE SINTERING MAY BE SHORTENED, THE POSITION OF THE UTZ IS CHANGED SELECTION ON THE BRICKS HAS TO FOLLOW THIS NEW POSITION

IF THE COMBUSTION OF SOLID FUELS IS NOT MASTERED IN THE FLAME ( INSUFFICIENT MIXING, TOO COARSE etc.. ) SOLID FUELS CAN FINISH BURNING ON THE BRICKS LOCAL REDOX CONDITIONS ON THE BRICKS

PROBLEMS WITH HIGH IMPULSE BURNERS FOR BRICKS

BURNER MANUFACTURERS HAD TO WORK ON NEW DETAILED DESIGNS ( BUT THEY KEPT THE BASIC PRINCIPLES OF OPERATION ) FOR FIRING PETCOKE AND ALTERNATIVE FUELS WE COULD CALLED THEM “MAS AR”, “PYROJET AR”, “ROTAFLAM AR” etc..

Gx = Gxa+ Gxr = (Qma× Va ) + (Qmr× Vr ) (N )

(N )

(N )

( kg / s )

(m / s)

( kg / s )

(m / s)

HOLCIM UNTERVARZ CEMENT PLANT Vision of a new mega burner Waste oil Contaminated water Tetra pack Plastic waste

Household waste Coal Paper Carboard

Liquid waste

Wood

Low calorific gas

Heavy fuel oil Distilation residues

ROTAFLAM® 125 MW for CEMENTOS APASCO / HOLCIM / Mexico Axial air channel Radial air channel Petcoke channel:

14.000 kg / h

Solid waste:

9.000 kg / h

Natural gas:

6.240 Nm³/ h

Heavy fuel oil: Waste oil:

11.300 kg / h 9.170 kg / h

WASTE FUEL FIRING : REAR PART OF A UNITHERM MAS BURNER

MIXING OF ALTERNATIVE FUEL IN BURNER CENTER

ROTAFLAM® SMALL SCALE TEST ROTAFLAM FLAME ADJUSMENT WITH A TEST TEST BURNER

ROTAFLAM CFD SIMULATION WITH CFD SIMULATION Q AIR RADIAL = 840 Nm3/h Q AIR AXIAL = 7000 Nm3/h

Q AIR RADIAL = 5700 Nm3/h Q AIR AXIAL = 2700 Nm3/h

ROTAFLAM® TIPS DESIGN MODIFICATIONS Previous Design: 1

2

3 4

1) Long axial excess at burner tip 2) Divergent axial air outlet 3) 45° Divergence of swirl air 4) 40° Swirl angle for swirl air Primary air pressure: 160–200 mbar Primary air amount: 6-8% Split Axial / Swirl: 40 / 60 Axial impulse: 2,8-3,8 N/MW Swirl number: 0,4-0,5

New Design: 1

2 3 4

1) Minimum axial excess at burner tip 2) Axial air outlet axis parallel 3) Reduced divergence of swirl air 4) Reduced swirl angle of swirl air Primary air pressure: 250 mbar Primary air amount: 8-12% Split Axial / Swirl: 65 / 35 Axial impulse: 8-12 N/MW Swirl number: 0,1-0,2

ISFAHAN CEMENT : GAZ BURNER WITHOUT CONTROL ( VERY LOW IMPULSE )

ISFAHAN : MULTICHANNEL GAZ BURNER ( LOW IMPULSE )

ISFAHAN : HIGH IMPULSE BURNER

COMPARISON OF TWO FLAMES WITH MULTICHANNELS BURNERS LOW IMPULSE WITHOUT CONTROL

HIGH IMPULSE UNDER CONTROL