CFB BOILER

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CFB BOILER TECHNOLOGY (CIRCULATING FLUIDIZED BED)

The basic concept of a CFB boiler is a stoker boiler (fluidized bed) in which coal is burned on a running chain and given a blow of air from the bottom so that the coal smolders above the chain. after repowering and redesigning, the boiler with the CFB type is obtained. In the following, we will briefly discuss the meaning, parts of the boiler, combustion concepts, comparisons of CFB and Pulvurized Coal boilers, general operating procedures, combustion processes, combustion control, and others.

A. the meaning of CFB

1. CIRCULATING :

The circulation of unburned coal from FURNACE to CYCLONE then enters SEALPOT and returns to FURNACE.

2. FLUIDIZED :

Primary blowing of air to keep bed material and coal floating in the furnace.

3. BED :

The material is in the form of small particles (quartz sand, bottom ash) which can be used as an initial medium for heat transfer from HSB combustion to coal combustion (100 tons)

B. 3 Main parts of a CFB type boiler

1. FURNACE

Serves as a place for burning fuel. components contained in the furniture: wall ntube, panel evaporator, super heater panel.

2. CYCLONE

Serves to separate unburned coal with ash (ash) remaining combustion and return it to the furnace. Cyclone main components : Cyclone, Sealpot, Seal Pot Dutch

3. BACKPASS

Serves as a space for the utilization of heat contained in the flue gas. The main components in the backpass are: Finishing, Superheater, Low temperature Superheater, Economizer, and Tubular Air Heater.

C. CFB Boil Boiler combustion concept

The combustion concept of this CFB boiler is:

– CFB Boiler capable of burning with low emission levels (very low Sox and Nox)

– Coal is burned in the floating “bed of material” and circulates in the burnace due to high air velocity causing fluidization of the bed material.

– Bed infentory consists of fuel, sorbent, inert sand, and reinjected coal from cyclone.