Abstract: A fluid-bed furnace has at least one combustion chamber, preferably two side-by-side, housing a bed of incombustible particulate material to be fluidized when burning fuel fed thereto. Bed fluidization is by forced release in the incombustible material of combustion promoting gas, normally air, from a plenum chamber arrangement externally of the bed proper at a side or end thereof to save overall height.

Abstract: A fluid-bed furnace has one or more combustion chambers containing a fluidizable bed 10 of particulate material. At least adjacent pairs of combustion chambers are shown to share a common exhaust gas outlet system 30. For the or each combustion chamber there is an in-bed removable chamber 35 for housing a bed preheating burner 36 and supplying fluidizing combustion promoting gas via transverse feed pipes 38, usually equipped with upstanding outlet heads. Bed material support is by a V- or U-section trough 32 also at least partially accommodating the chamber 35 and a material extraction feed 34.