Download - Atmospheric Fluidised Bed Combustion Boiler
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B&W
Atmospher ic F lu id ised Bed Combust ion Boi lers
for F i r ing Sol id Fuels
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Historically, Babcock & Wilcox has maintained an ongoing program to develop advanced
technologies which offer the potential for more efficient, cost effective and reliable steam
generation. One of these advanced technologies is Atmospheric Fluidised Bed
Combustion (AFBC), which promises to provide a viable alternative to conventional coal
fired and other solid fuel fired boilers for utility and industrial applications.
B & W began investigating various aspects of the AFBC process in the mid -70s and has
become the technological leader among boiler manufacturers in AFBC development for
utility and industrial use.
ADVANCED TECHNOLOGIES
FOR POWER GENERATION
Flow Modelled Fuel Feed System
Combustor Components
Fuel Feed Mixing Nozzles Studded Carbon Steel Inbed Evaporator and
Stainless Steel Inbed Superheater Tubes
Atmospheric Fluidised Bed Combustion Boilers (AFBC)
Secondary Over Fire Air Arrangement
110 TPH AFBC Control Room
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SALIENT FEATURES OF TBW AFBC BOILER
Boiler
Furnace
Cold AirCold
Ash
Drain
Hot
AirHot
Bed
Ash
Fluid bed ash coolers for cooling bed
ash. Air is used to cool ash. Flue gas
sent back to the air heater to recover
sensible heat resulting in further
improvement in efficiency.
Inclined airholes prevent bed material re-entry
eliminating back shifting.
Stainless steel air (Bubble Cap) nozzles for primary air
are designed for higher pressure drop to achieve
higher turndown ratios. The entire nozzle including the
shaft pipe is made of stainless steel.
Underbed fuel feed system using drag chain
feeders for smooth flow of high moisture
fuel to furnace. Hot air for transport of fuel
inside combustor for smooth flow of fuel in
the feed lines. No bends on fuel transport
lines improves availability.
Secondary overfire air is
provided from both sides of
furnace to ensure complete
combustion, resulting in
minimum unburnt, reduced
c a r b o n m o n o x i d e a n d
improving efficiency.
B&W design two stage
s t e a m s e p a r a t i n g
equipment inside the
drum ensures turbine
q u a l i t y s t e a m .
Guaranteed 99.99 %
steam purity even
under conditions of
rapid load changes.
In line, spaced bed evaporator tubes for
better access to bed plate. Pin studs welded
on inbed surfaces and furnace walls
eliminate tube erosion completely.
Distributor plate 16 mm thick carbon steel.
Shop assembled, machine
welded membrane panels
allow for less refractory and
make a gas tight enclosure
resulting in less leakage and
improved efficiency.
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The challenge of the AFBC process is to burn fuel in an environmentally acceptable manner yet showing economic
promise. The AFBC Boiler achieves this by carrying out combustion in a bed of crushed refractory / sand which is
suspended by an upward stream of air, fluidising it and facilitating a significant higher degree of combustion
completeness. In addition to this inherent advantage of the fluidised bed combustion process, design and operating
characteristics of TBW AFBC boilers offer a number of advantages for industrial steam and power generation.
Combustion temperatures of the AFBC process are maintained below the fuel ash softening temperature, so low-
grade fuels can be burned without the risk of slagging and fouling in the boiler. The lower temperatures also limit the
formation of nitrogen oxides. Fuels like coal, washery rejects, lignite (Kutch, Neyveli), petcoke, rice husk, DOB,
bark, effluent sludge from paper mills, viscose plant, coffee waste etc. can be effectively burnt in TBW
AFBC Boilers.
Due to lower operating temperatures, the TBW AFBC boiler design is less dependent on fuel and fuel ash
characteristics than conventional boilers.
SOx control is achieved by limestone addition.
sludge from
Load Vs Efficiency
EFFIC
IEN
CY
83
82
84
85
86
87
88
LOAD % MCR
30 40 50 60 70 80 90 100 110
Fuel : Coal with 45% ash
TBW TECHNOLOGY :
HIGH AVAILABILITY & EFFICIENCY
Boiler Availability*
JA
N 0
2
FEB
0
2
MA
R 0
2
AP
R 0
2
MAY
0
2
JU
N 0
2
JU
L 0
2
AU
G 0
2
SEP
0
2
OC
T 0
2
NO
V 0
2
DEC
0
2
% A
VA
ILA
BIL
ITY
0
100
MONTHS
* Based on actual observations at an operating unit.
71.5
98.11100
93.82
20
40
60
80
100
120
99.44 100 100 100 100 100 100 100 100 100
59
100
90.5
100 100
94.4
100 100 100
JA
N 0
3
FEB
0
3
MA
R 0
3
AP
R 0
3
MAY
0
3
JU
N 0
3
JU
L 0
3
AU
G 0
3
SEP
0
3
OC
T 0
3
NO
V 0
3
DEC
0
3
Plant
Shutdown
Planned
Shutdown
Capacity
Enhancement
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Designed and manufactured to the legendary Babcock & Wilcox quality incorporating the latest advances in boiler and control technology,
making it the most efficient and reliable boiler for combustion of diverse range of difficult fuels.
Capacity Range : Up to 300 TPH
2
Pressure : Up to 135 Kg/cm g
Temperature : Up to 540 C
Fuel : Coal / Lignite / Petcoke / Rice Husk / Pith /Oil / Agricultural Waste /
Washery Rejects / Char / Biomass / Spent Coffee Waste / Spent Tea
Waste, etc., Sawdust, DOB
Design Feature : Top or bottom supported, Single or Bi-drum design boilers suitable for
firing low calorific value fuels. Suspension burning of fuel - higher
combustion efficiency.
Coal Size 6 mm Bubbling Bed Ash Coolers Stainless Steel
Inbed Superheater Stainless Steel Fluidizing Nozzles Boiler
Bank without Baffles High Steam Purity Membrane Wall Furnace
Start-up by Oil / Charcoal
ATMOSPHERIC FLUID BED
COMBUSTION BOILER
(Underbed & Overbed feed system design)
FUEL
BUNKER 1
FUEL
BUNKER 2
ASH
DRAIN
PIPES
P A FAN
STEAM
DRUM
ACCESS
DOOR ON
L,H, SIDE
GROUND
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Salient Features
! Combustor does not have any moving parts thus reducing
maintenance in the furnace.
! Uniform Temperature distribution in the bed and agitating
characterstic of fluid bed ensures optimum combustion.
! Low excess air requirement resulting in higher efficiency.
! Lower NOx and CO emissions.
! Low SOx emission with limestone addition.
! Low temperature operation minimises the biomass fuel
ash agglomeration and fouling tendency.
HOPPER BOTTOM (FLUID BED)
! Continuous slow draining of bed ash which aids:
= Easy settling and disposal of large sized particles which
hamper fluidisation.
= Maintaining alkali concentration below acceptable levels.
= Avoiding accumulation of denser particles in bed in
maintaining uniform bed density across the entire bed.
! Under bed / over bed fuel feeding for proper distribution
of fuel.
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AFBC INSTALLATIONS
CLIENT NOS2
Kg/cm g FUEL YEARCap,
(TPH)Deg C
Mysore Paper Mills 2 60 63 460 Coal 1991
Central Pulp Mills 1 50 42 440 Coal/Lignite 1992
BILT for Sewa Paper Mills 1 45 42 440 Coal 1992
Mysore Paper Mills 1 60 63 460 Coal 1993
Nestle India Ltd. 1 14 24 Sat Spent Coffee Grounds, Coal, 1994
Coconut Shell, Spent Tea
JK Corporation 1 60 37 410 Coal 1995
Servall Engineering 1 44 13 209 Lignite 1995
GHCL 1 90 105 505 Lignite/Coal 1996
L&T 2 95 66 495 Coal/Washery Middlings 1996
Vardhaman Acrylic Ltd. 1 42 45 420 Coal 1997
L&T for Usha Martin 1 110 66 495 Coal 1998
Jocil Ltd. 1 30 66 485 Rice Husk, Coal, Cotton Stalk, Julia Fora 1999
JCT Ltd. 1 35 44 420 Coal. Rice Husk 2000
Khanna Paper Mills Ltd. 1 70 66 485 Rice Husk/Padtal 2000
India Glycols Ltd. 1 45 34 400 Rice Husk/Coal/Bio-Gas 2000
Oswal Chemical & Fertilisers Ltd. 2 110 63 485 Coal 2001
Saro Power & Infrastructure Ltd. 1 35 66 495 Coal/Rice Husk, Cotton Stalk, Julia Fora 2001
Shree Cements Ltd. 2 80 65 495 Imported Coal, Petcoke, Lignite 2001
Nestle, Thailand. 1 15 18.5 Sat Spent Coffee Ground 2001
Nova Petrochemicals Ltd. 1 47 47 495 Imported Coal, Petcoke, Lignite, 2001
Indian Coal, Sawdust/GN Shell
Nav Bharat Ferro Alloys Ltd. 2 65 93 515 Coal/Washery/Petcoke 2002
Sangam Spinners 1 50 66 495 K. Lignite/Petcoke 2002
Chaddha Papers Ltd. 1 50 65 490 Coal/Rice Husk/Petcoke 2002
Bhushan Ltd. 1 75 88 520 Washery Rejects/Char 2003
Sree Rayalseema Alkalies & 1 100 100 525 Coal 2003
Allied Chemicals Ltd.
Gujarat Ambuja Cements Ltd. 2 45 67 495 Rice Husk/Coal/Petcoke 2003
Nestle Russia Ltd. 1 18 22 Sat Spent Coffee Ground/Natural Gas & Diesel 2003
Khanna Paper Mills Ltd. 1 100 66 500 Petcoke/Rajasthan Lignite Paper Sludge 2003
& Plastic waste
West Coast Paper Mill 1 65 43.5 415 Coal 2003
Chettinad Cement Ltd. 1 68 87 515 Imported Coal, Indian Coal, Neveyli Lignite 2003
Madras Cement Ltd. 2 76 89 515 Imported Coal, Petcoke, Lignite 2003
Nestle Philippines Inc. 1 24.95 18 D&S Spent Coffee Ground, Green Coffee 2004
Residue, Roasted, Roasted Chaffs & HFO
ITC, Dakshin 1 60 64 485 Lignite, Sawdust, DOB 2004
Bhushan Ltd. 1 165 88 520 Washery Rejects/Char 2004
South Pacific Viscose 1 45 45 450 Coal/Viscose Sludge 2004
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AFBC INTALLATIONS / FEATURES
Usha Martin Industries Ltd.
Jamshedpur
Capacity : 110 TPH
Fuel Used : Coal
Research & Development
Shot Blasting Machine
Furnace Panels
in Shop Floor
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OTHER PRODUCTS & AFBC FEATURES
Inbed Evaporator
Assembly at Shop
Stainless Steel Dense
Studs for Inbed Tubes
Membrane Welding
Installation at Kanoria Chemicals
Capacity : 105 TPH
Fuel used : Coal
CFBC Boiler
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B&W
Thermax Babcock & Wilcox Limited
Pune
D-1 Block, Plot No 7/2, R.D. Aga Road,
M.I.D.C, Chinchwad, Pune 411 019, India.
Tel: 91-20-4126464 Fax: 91-20-27479200
Email: [email protected]
Mumbai
Dhanrajmahal 2nd floor,
Chhatrapati Shivaji Maharaj Marg,
Near Gateway of India, Colaba,
Mumbai 400 039, India.
Tel: 91-22-22045391, 22045324,
Fax: 91-22-22040859
Delhi
9, Community Centre, Basant Lok,
New Delhi 110 057, India.
Tel: 91-11-26145319, 26145326,
Fax: 91-11-26148679
Chennai
Fatima Akthar Court,
3rd floor, 312 Anna Salai,
Teynampet, Chennai 600 018, India.
Tel: 91-44-24353831, 24353834,
Fax: 91-44-24353841
Kolkata
Azimganj House, 5th Floor,
7 Camac Street, Kolkata 700 017, India.
Tel: 91-33-22826711/2/3,
Fax: 91-33-22826796
Hyderabad
6-3-649 Nalanda Complex
Somaji Guda, Hyderabad 500 082 India.
Tel: 91-40-23310254, 23312013, 23396820
Fax: 91-40-23312335
www. tbw ind i a . com Synerg
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