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M.A.S. Burner TRAINING
Content
• M.A.S. burner design• Flame control by M.A.S. burner • Burning of
• Natural gas •Trouble shooting
• Position of the Burner • Service and maintenance
Unitherm Cemcon Firing Systems
Company Experience
Unitherm Cemcon Firing Systems
Establishment- 1949
Field of activity- engineering, production and installation of firing systems for industry and power stations
Experience in rotary kiln burners- more than 300 pcs.
1992- technological breakthrough: development of a new burning system generation called M.A.S. (Mono Airduct System)
1997- reduction of product scope to firing equipment for cement industry
At the moment UNITHERM-CEMCON is one of the leading manufacturers of firing systems in the cement industry. Until now numerous M.A.S. burners all over the world have been supplied and commissioned to the full satisfaction of our customers. The excellent operational experiences and the low NOx levels convinced major cement producers to choose the M.A.S. burner for replacement and for new plants as well.
Kiln capacity, heat consumption and clinker quality are defined by:
Unitherm Cemcon Firing Systems
1. Correct composition of raw meal
1.1 Chemistry Burnability
1.2 Meal fineness
2. Correct burning conditions
2.1 Fuel input and fuel distribution (kiln-calciner) ProcessKiln atmosphere (oxidizing) control
2.2 Kiln temperature profileflame shape control---burner design
2.3 Clinker residence timeburner position in kiln
2.4 Clinker cooling
M.A.S.® -Rotary Kiln BurnerBasic design
Primary air inlet
Flame setting devicewith scale
Primary (MAS) air damper
Outer jacket tube
Flexible swirl device
Nozzle outstream system
Coal dust inlet
Flexible air nozzles system for flame shape adjustment
Patent No: 0642645
Unitherm Cemcon Firing Systems
Central air damper
M.A.S.® -Gas Rotary Kiln Burner
Unitherm Cemcon Firing Systems
Swirl setting device
M.A.S.- main air
Central air
Unitherm Cemcon Firing Systems
3 Stages of clinker burning optimisation with M.A.S. burner
1st Stage: Control of flame shape by flame setting device 2nd Stage: Control of combustion intensity by adjustment of the M.A.S.-air
pressure 3rd Stage: Control of flame core temperature by adjustment of the central
air pressure
Unitherm Cemcon Firing Systems
1st Stage: Control of flame shapeby flame setting device
Unitherm Cemcon Firing Systems
1st Stage: Control of flame shapeby flame setting device
1st Stage: Control of flame shape
Unitherm Cemcon Firing Systems
by flame setting device
Unitherm Cemcon Firing Systems
Jets flow pattern
Jet flow Ring channel flow
nozz
le
gap
m/s
gap
nozz
le
nozz
le
m/s
ring channelSS
Burner NozzleM.A.S. - system
Burner Nozzle traditional three channel burner (basic)
as
ap
e
l
ap
asap
TT
nD
XmM
MM
,
,
,
,, 2
as
ap
e
l
ap
asap
TT
DXm
MMM
,
,
,
,, 2
The mixing zone for jets flow is shorter proportionally n1/2
n- jets number
1st Stage: Control of flame shape
FLAMEFLAME
FLAME SHAPE
SHORTLONG 1 2 3 4 5 6 7 8 9FLAMEFLAME
FLAME SHAPE
SHORTLONG 1 2 3 4 5 6 7 8 9
Unitherm Cemcon Firing Systems
by flame setting device
FLAMEFLAME
FLAME SHAPE
SHORTLONG 1 2 3 4 5 6 7 8 9
medium-sized flame narrow, long flamewide, short flame
1st Stage: Control of flame shape
Unitherm Cemcon Firing Systems
by flame setting device
2nd Stage: Control of combustion intensity
Unitherm Cemcon Firing Systems
M.A.S. air damper M.A.S. air pressure
by adjustment of the M.A.S.-air pressure
2nd Stage: Control of combustion intensity
Unitherm Cemcon Firing Systems
800
1000
1200
1400
1600
1800
2000
high pressure 50 mbarhot, short flame
medium pressure 30-50 mbar
low pressure < 10-20 mbarsoft, long flame
kiln length
Flam
e te
mpe
ratu
re, °
C
by adjustment of the M.A.S.-air pressure
3rd Stage: Control of flame core temperature
Unitherm Cemcon Firing Systems
Central air damper
Central air pressure
by adjustment of the central air pressure
3rd Stage: Control of flame core temperature
By increasing the central-air pressure, the flame gets stable but the temperature drops in the flame root, close to the burner head.
Unitherm Cemcon Firing Systems
by adjustment of the central air pressure
Path lines of central air colored by temperature [k]; note: no stabilizing swirl on l.h.s
Central air pressure 10 mbar Central air pressure 60 mbar
3rd Stage: Control of flame core temperature
Unitherm Cemcon Firing Systems
by adjustment of the central air pressure
Contours of temperature [k]
Central air pressure 10 mbar Central air pressure 60 mbar
3rd Stage: Control of flame core temperature
Unitherm Cemcon Firing Systems
Flame root temperature
central air pressure, mbar
by adjustment of the central air pressure
NOx-emission
0 10 20 30 40 50 60 70 80
Unitherm Cemcon Firing Systems
3 Stages of clinker burning optimisation with M.A.S. burner
Initial settings for medium-sized flame
Fuels in operationPressure of M.A.S.
– airM.A.S.
swirl numberPressure of central
air
mbar Setting on scale mbar
Natural gas 40-50 2-3 20-30
Light fuel oil 100 – 130 3 – 5 40 – 150
Heavy fuel oil 110 -140 3 – 5 40 – 150
Liquid secondary waste fuel oils 100 -140 3 – 5 40 – 150
Coal dust – high volatile 120– 160 4 – 6 40 – 150
Coal dust – low volatile 150 – 200 4 – 6 40 – 150
Solid secondary waste fuels 120 – 180 4 – 6 40 – 150
Unitherm Cemcon Firing Systems
3 Stages of clinker burning optimisation with M.A.S. burner
Initial settings for narrow, long flame
Fuels in operation Pressure of M.A.S. – air
M.A.S.swirl number
Pressure of central air
mbar Setting on scale mbar
Natural gas 10-30 0– 1 10-20
Light fuel oil 70 1 – 2 40 – 150
Heavy fuel oil 70 – 100 2 – 3 40 – 150
Liquid secondary waste fuel oils 70 – 100 2 – 3 40 – 150
Coal dust – high volatile 100 – 120 2 – 3 40 – 150
Coal dust – low volatile 140 – 150 3 – 4 40 – 150
Solid secondary waste fuels 100 – 120 3 – 4 40 – 150
Unitherm Cemcon Firing Systems
3 Stages of clinker burning optimisation with M.A.S. burner
Initial settings for wide, short flame
Fuels in operation Pressure of M.A.S. – air
M.A.S.swirl number
Pressure of central air
mbar Setting on scale mbar
Natural gas 50-70 3-5 50-60
Light fuel oil 160 – 200 6 – 7 40 – 150
Heavy fuel oil 180 – 220 6 – 7 40 – 150
Liquid secondary waste fuel oils160 – 220 6 – 8
40 – 150
Coal dust – high volatile160 – 220 5 – 8
40 – 150
Coal dust – low volatile 200 – 220 6 – 8 40 – 150
Solid secondary waste fuels180 – 220 6 – 8
40 – 150
Burner position in rotary kiln
Unitherm Cemcon Firing Systems
- especially for rotary kiln with grate cooler a proper axial position of the burner is very important!- 20 cm movement of the burner, moves the sinter zone up to 1m!- sometimes NOx - emissions depends on burner position drastically!- the clinker mass composition as well clinker characteristics depend on length of the cooling zone within the kiln, means also defined by burner axial position. We recommend to keep 1200-1250°C clinker temperature at the kiln edge
Temperature [K] Velocity [m/s]
Burner position in rotary kiln with grate cooler
Unitherm Cemcon Firing Systems
Initial position X=0for petcoke, solid secondary fuel, coal- following kiln axisfor natural gas or fuel oil- turn more horizontal (rotate around fix point) up to
maximum 3% less as kiln slope
Burner position in rotary kiln with satellite coolers
Unitherm Cemcon Firing Systems
Initial position X=1000for petcoke, solid secondary fuel, coal- following kiln axisfor natural gas or fuel oil- horizontal (rotate around fix point)
Burner position in rotary kiln
Unitherm Cemcon Firing Systems
Further optimisation
-move the burner tip to the clinker-keep the flame away from the coating -find the best axial position of the burner:
General considerations to burner axial position
-burner tip deep inside the kiln >> 0,5 m-risk of reduced kiln capacity and high flue gas temperature at kiln inlet-more straight flame -better fuel ignition -reduced risk of ring formation at kiln outlet
-burner tip inside the kiln < 0,5 m (usual position)-increase of kiln capacity and reducing of the flue gas temperature at kiln inlet-risk of uneven flame due to kiln outlet eddy (high turbulence of sec. air)-worse fuel ignition-risk of ring formation at kiln outlet or snowman in cooler
Trouble shooting
Unitherm Cemcon Firing Systems
Coating ring at kiln discharge
1.1 Move the burner into the kiln with 20 cm steps1.2 Adjust more soft, long flame by swirl setting device1.3 Decrease central air pressure1.4 Decrease M.A.S.-air pressure
Trouble shooting
Unitherm Cemcon Firing Systems
Permanent coating ring at the beginning of the sinter zone
1.1 Change the soft long flame to short hot flame each 4-8 hours1.2 For example:
Long flame : flame setting device Pos.0-2Short flame: flame setting device Pos.3-5
Trouble shooting
Unitherm Cemcon Firing Systems
Poor clinker burning, high free lime content in clinker, high CO-content in flue gas
1.1 Increase the M.A.S.-air pressure
1.2 Find the maximum flame core temperature with central air pressure
1.3 Adjust wide, short flame by flame setting device
1.4 Check oxygen content in flue gas and pressure difference through the kiln. Increase the secondary air flow.(If I.D. fan doesn‘t have sufficient power, decrease tertiary air flow)
Trouble shooting
Unitherm Cemcon Firing Systems
Brown clinker, reducing burning condition
1.1 Check oxygen content in flue gas and pressure difference through the kiln. Increase the secondary air flow.(If I.D. fan doesn‘t have sufficient power, decrease tertiary air flow)
1.2 Increase pressure of the M.A.S.-air and central air
1.3 Change the position of the burner tip in kiln
1.4 Adjust soft, long flame by flame setting device
Trouble shooting
Unitherm Cemcon Firing Systems
High kiln shell temperature, poor coating
1.1 Adjust soft, long flame by flame setting device
1.2 Decrease the M.A.S.-air pressure
1.3 Decrease the central air pressure
1.4 Decrease the secondary air flow with I.D. fan
1.5 Use the outer cooling of kiln shell with auxiliary fans
Trouble shooting
Unitherm Cemcon Firing Systems
High kiln shell temperature, poor coating
1.6 Change chemistry of the raw meal
COATING CONDITIONS
86
88
90
92
94
96
98
1,5 2 2,5 3 3,5 4
Silica Ratio
Lim
e sa
tura
tion
fact
or
Hard to burn clinkerDifficultes to form coating
Easy to burn clinkerPossible coating ring formation
Normal
Normal
Trouble shooting
Unitherm Cemcon Firing Systems
To remove more sulfur with clinker (clogging problem)
1.1 Adjust more hot flame
1.2 Increase oxygen content of 1-3%– more air through the kiln line
Parameters affecting NOx:
• Burning zone temperature• Free lime• LSF• Secondary air temperature• Sec.air flow characteristics
(cooler type)• Thermal kiln loading• Kiln design –staged
combustion in calciner• Fuel grinding size and
volatiles content• Burner tip position in kiln
Pyroprocess
Unitherm Cemcon Firing Systems
Trouble shooting
Parameters affecting NOx:
• Fuel surrounded by primary air (staged combustion)
• Low primary air amount (momentum)
• Close fuel ignition distance• Mixing intensity of fuels (swirl
number)• Burner settings (avoid
oxygen inside flame root)
Burner design
Unitherm Cemcon Firing Systems
Typical low NOx design
Trouble shooting
Impact of Central Air on NOx
Primary Air Pressure: 150mbar
Central Air Pressure: 25 mbar
NOx (Kiln Inlet): 1300 mg/m³
Primary Air Pressure: 150mbar
Central Air Pressure: 125 mbar
NOx (Kiln Inlet): 2700 mg/m³
Unitherm Cemcon Firing Systems
Trouble shooting
Trouble shooting
Unitherm Cemcon Firing Systems
Decreasing of NOx Emissions
1.1 Decrease M.A.S.-swirl on the swirl setting device to a narrow, long flame shape
1.2 Decrease pressure of the M.A.S.-air
1.3 Adjust pressure of central-air (try the upper and lower limit)
1.4 Increase coal-dust injection velocity
1.5 For solid secondary fuel burning - decrease pressure of Pneumoswirl-air
1.6 Change the position of the burner tip in kiln
1.7 Decrease temperature of secondary air (if possible)
Service and Maintenance
Unitherm Cemcon Firing Systems
Daily inspections
During operation, the rotary kiln firing equipment must be inspected at least once per working shift and at least the following controls carried out:
• Check functioning of the burner and visible damage or defects• Check flame shape• Visual check of burner insulation• Check equipment for sealed tightness (flange and tube connections, etc.)• Check functioning of operating displays (thermometer, pressure gauges,
flow control instruments, etc.)• Check equipment for suspicious sounds and vibrations
Service and Maintenance
Unitherm Cemcon Firing Systems
Periodical inspectionsThe following inspections should be carried out about every 3 months, or in the case of a plant standstill:
• Inspection of burner insulation;• Inspection of the all burner / lance nozzles for wear or deposits; • Inspection of input pipe at the pulverized coal connection and the
centering ribs for the coal dust nozzle for wear and tear• Inspection of the flexible flame setting device for smooth running• Inspection of oil / gas and air hoses• Inspection of the smooth functioning of fittings and gears• Inspection of bearings lubricated with oil and grease, and the carrying
out of service work in accordance with detailed descriptions of devices• Inspection of the solid secondary fuel channel for wear or deposits
Service and Maintenance
Unitherm Cemcon Firing Systems
Replacement of the nozzlesFor dismantling push the bolts of the nozzle wrench in the corresponding holes located on the nozzle and unscrew the nozzle.When the nozzle is loose, take it off by unscrewing the last few turns by hand.
Unscrew with nozzle wrench Take off nozzle by hand
Service and Maintenance
Unitherm Cemcon Firing Systems
Replacement of the baffle plateTo replace the baffle plate the innermost nozzle must be screwed off first,because the baffle plate is clamped between this innermost nozzle and inside located bolts.When the innermost nozzle is dismantled, take out the baffle plate by hand
innermost nozzle is dismantled take out the baffle plate
ReferencesM.A.S.-burners have been successfully operating in a lot of cement plants over the world
Unitherm Cemcon Firing Systems