ABSTRACT
Coal can be burned in a bed where the grate is fixed in space and combustion takes place with an upward flow of air through the bed. The combustion of the bed of coke particles thus formed on the fire grate is maintained by the upward stream of air that passes through a layer of ashes on the bottom of the grate before it comes into contact with the coke. The rate of feed and the stoker grate speed are affected by the rates of ignition and combustion. The atmospheric fluidized-bed-combustion (AFBC) process consists of forming a bed of inert materials such as finely sized ash or ash mixed with sand, limestone, and solid fuel particles in a combustor and fluidizing it by forcing combustion air up through the bed mixture. Atmospheric fluidized-beds have passed the research and development stage, and AFBC units have commercially been available; there are many hundreds of units installed worldwide, especially in China.
