Circulating Fluidized Bed (CFB) Boilers


A circulating fluidized bed (CFB) boiler features higher gas velocity (superficial flow velocity) in the furnace (combustor) compared with a bubbling fluidized bed (BFB) boiler. The boiler activates a mixture of particles and gas to improve combustion reaction. Moreover, the fluid sand and fuel issuing out of the furnace are collected in a cyclone and recirculated into the furnace again, thereby improving combustion efficiency.



Supports a wide variety of fuels

Circulating fluidized bed (CFB) boilers from Mitsubishi Power are able to combust a wide range of fuels, including bituminous coal, brown coal, anthracite, petroleum coke, wood biomass, paper sludge, RPF (refuse paper & plastic fuel) and waste tires, and have high combustion efficiency.

Low environmental impact

As for temperatures inside the furnace, while a regular boiler reaches 1,400-1,500°C, temperatures inside a CFB are in the low range of 800-900°C, thus inhibiting the generation of thermal nitrogen oxides (NOx whose production is dependent on combustion temperature). Further, with the use of two-stage combustion, NOx generation can be limited to less than 100 ppm. When limestone is supplied to the furnace, furnace desulfurization can take place as illustrated by the following chemical equations.

CaCO3 → CaO+CO2

CaO+SO2+1/2O2 → CaSO4

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Also note that with our CFB boilers, by controlling the amount of particles supplied to the fluidized bed heat exchanger (FBHE), even when partial loading occurs or there is a change in the calorific value of the fuel, furnace temperature can be optimized for combustibility and furnace desulfurization.

Delivery Records

Circulating Fluidized Bed Boiler - Single-trunk Natural Circulating Type (Outdoor Model)

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Maximum continuous rating 170 t/h
Steam conditions Steam pressure 13.2 MPag
Steam temperature 540°C
Main Fuels Fuel chips, tire chips, RPF, sludge, screen cake, bark, pruned tree, straw pellets, in-facility waste, Bunker A
Start of operation 2008