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COAL Presentation Transcript
1.COAL
2.Boiler Types and Classifications
Fire in tube or Hot gas through tubes and boiler feed water in shell side
Fire Tubes submerged in water
Application
Used for small steam capacities
( upto 12000 kg/hr and 17.5kg/cm2
Merits
Low Capital Cost and fuel Efficient (82%)
Accepts wide & load fluctuations
Steam pressure variation is less (Large volume of water)
Packaged Boiler
Fire in tube or Hot gas through tubes and boiler feed water in shell side
Fire Tubes submerged in water
Application
Used for small steam capacities
( upto 12000 kg/hr and 17.5kg/cm2
Merits
Low Capital Cost and fuel Efficient (82%)
Accepts wide & load fluctuations
Steam pressure variation is less (Large volume of water)
Packaged Boiler
3.Chain Grate or Traveling Grate Stoker Boiler
Coal is fed on one end of a moving steel chain grate
Coal burns and ash drops off at end
Coal grate controls rate of coal feed into furnace by controlling the thickness of the fuel bed.
Coal must be uniform in size as large lumps will not burn out completely
Bed thickness decreases from coal feed end to rear end and so more air at front and less air at rear end to be supplied
Water tube boiler
Coal is fed on one end of a moving steel chain grate
Coal burns and ash drops off at end
Coal grate controls rate of coal feed into furnace by controlling the thickness of the fuel bed.
Coal must be uniform in size as large lumps will not burn out completely
Bed thickness decreases from coal feed end to rear end and so more air at front and less air at rear end to be supplied
Water tube boiler
4.Fluidized bed Combustion (FBC) boiler
When an evenly distributed air or gas is passed upward through a finely divided bed of solid particles such as sand supported on a fine mesh, the particles are undisturbed at low velocity. As air velocity is gradually increased, a stage is reached when the individual particles are suspended in the air stream
When an evenly distributed air or gas is passed upward through a finely divided bed of solid particles such as sand supported on a fine mesh, the particles are undisturbed at low velocity. As air velocity is gradually increased, a stage is reached when the individual particles are suspended in the air stream
5.Coal is pulverised to a fine powder, so that less than 2% is +300 microns, and 70-75% is below 75 microns.
Coal is blown with part of the combustion air into the boiler plant through a series of burner nozzles.
Coal is blown with part of the combustion air into the boiler plant through a series of burner nozzles.
6.PULVERISED FORM OF COAL
IT HAS MADE MODERN STEAM GENERATING UNITS HIGHLY THERMAL EFFICIENT, RELIABLE AND SAFE.
IT HAS MADE EFFICIENT USE OF LOW GRADE COALS.
IT PROVIDES GOOD CONTROL OVER COAL AIR MIXTURE PROPORTION, FLAME STABILITY WITH MINIMUM LEVEL OF UNBURNT CARBON.
IT HAS MADE MODERN STEAM GENERATING UNITS HIGHLY THERMAL EFFICIENT, RELIABLE AND SAFE.
IT HAS MADE EFFICIENT USE OF LOW GRADE COALS.
IT PROVIDES GOOD CONTROL OVER COAL AIR MIXTURE PROPORTION, FLAME STABILITY WITH MINIMUM LEVEL OF UNBURNT CARBON.
7. TYPE OF COALS
BASED ON PROXIMATE ANALYSIS OF COAL ON DRY BASIS:
ANTHRACITE
BITUMINOUS
SUB-BITUMINOUS
LIGNITE
BASED ON PROXIMATE ANALYSIS OF COAL ON DRY BASIS:
ANTHRACITE
BITUMINOUS
SUB-BITUMINOUS
LIGNITE
8.TYPES OF PULVERISERS
BASED ON PRINCIPLES OF PARTICLE SIZE REDUCTION
IMPACT
ATTRITION
CRUSHING
PULVERISERS USE ONE, TWO OR ALL THE THREE PRINCIPLES.
9.TYPES OF PULVERISERS
BASED ON PRINCIPLES OF PARTICLE SIZE REDUCTION
IMPACT
ATTRITION
CRUSHING
PULVERISERS USE ONE, TWO OR ALL THE THREE PRINCIPLES.
9.TYPES OF PULVERISERS
10.NOMENCLATURE- BOWL MILLS
583 XRS/ 803 XRP BOWL MILLS
58,80 STANDS FOR BOWL DIAMETER IN INCHES
IF THE NUMBER IS EVEN THEN ITS SHALLOW BOWL MILL.
IF THE NUMBER IS ODD THEN ITS DEEP BOWL MILL
3 - NUMBER OF ROLLERS THREE NOS.
X - FREQUENCY OF POWER SUPPLY 50 CYCLES. IN USA ’ X’ MEANS 60 CYCLES.
R- RAYMOND, NAME OF THE INVENTOR
S- SUCTION TYPE WITH EXHAUSTER AFTER MILL
P- PRESSURISED TYPE WITH P.A. FAN BEFORE MILL.
583 XRS/ 803 XRP BOWL MILLS
58,80 STANDS FOR BOWL DIAMETER IN INCHES
IF THE NUMBER IS EVEN THEN ITS SHALLOW BOWL MILL.
IF THE NUMBER IS ODD THEN ITS DEEP BOWL MILL
3 - NUMBER OF ROLLERS THREE NOS.
X - FREQUENCY OF POWER SUPPLY 50 CYCLES. IN USA ’ X’ MEANS 60 CYCLES.
R- RAYMOND, NAME OF THE INVENTOR
S- SUCTION TYPE WITH EXHAUSTER AFTER MILL
P- PRESSURISED TYPE WITH P.A. FAN BEFORE MILL.
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