Abstract: In a fluidized bed plant for the combustion of impure solid fuel in the presence of an absorbent material which absorbs and neutralizes the impurities, in particular sulfur, the supply of absorbent material to the fluidized bed is controlled in dependence on the impurity content in the exhaust gases leaving the fluidized bed. To achieve a rapid control, at least part of the absorbent material is supplied to the fluidized bed in a finely ground state. The bed material may consist of coarse-grained absorbent material or a chemically inactive material, or a mixture of these. Coarse-grained absorbent material which is discharged from the fluidized bed can have its particle size reduced and be passed back to the fluidized bed.

Abstract: A fluidized bed combustion chamber adaptable for use with relatively large gas turbines and the like, wherein a substantially spherically-shaped outer casing encloses an annular fluidized bed combustion chamber which is mounted on a double bottom air distribution box. A cleaning assembly is positioned within the fluidized bed and the entire combustion chamber is supported on a base plate which extends through the casing and into contact with the box. Compressed air enters the spherical casing, is directed through a pair of cooling gaps, is caused to enter the air distribution box and then passes through the fluidized bed.