Method and apparatus for producing a useful stream of hot gas from a fluidized bed combustor while controlling the bed's temperature

Claim 1

A method of producing a useful stream of hot gas from a fluidized bed combustor while controlling the temperature of the bed comprising: (1) creating and maintaining a fluidized bed within a combustion chamber, said fluidized bed comprising a turbulent suspension of particulate matter from which particulate matter is thrown into the freeboard region above the bed at a temperature substantially equal to the temperature of the bed; (2) introducing fuel into the fluidized bed and combusting substantially completely said fuel in said bed; (3) capturing and feeding back into the bed particulate matter blown out of the combustion chamber; and (4) introducing cooling gas, which has a temperature relatively lower than bed temperature and at which the cooling gas quenches combustion in the freeboard region, substantially horizontally into the freeboard region and into contact with particulate matter thrown into the freeboard region and lowering the temperature of the particulate matter while raising the temperature of the cooling gas before the particulate matter recycles by falling back into the bed or by being captured and fed into the bed after blowing out of the combustion chamber.

Claim 2

A method of producing a useful stream of hot gas from a fluidized bed combustor while controlling the temperature of the bed comprising: (1) creating and maintaining a fluidized bed within a combustion chamber, said fluidized bed comprising a turbulent suspension of particulate matter from which particulate matter is thrown into the freeboard region above the bed at a temperature substantially equal to the temperature of the bed; (2) introducing fuel into the fluidized bed and combusting substantially completely said fuel in said bed; (3) capturing and feeding back into the bed particulate matter blown out of the combustion chamber; and (4) introducing cooling gas, which has a temperature relatively lower than bed temperature and at which the cooling gas quenches combustion in the freeboard region, substantially horizontally into the freeboard region and into contact with particulate matter thrown into the freeboard region and lowering the temperature of the particulate matter while raising the temperature of the cooling gas before the particulate matter recycles by falling back into the bed or by being captured and fed into the bed after blowing out of the combustion chamber.