Abstract: The vertical fuel pipe of a fluidized bed extends up through the perforated support structure of the bed to discharge granulated solid fuel into the expanded bed. A cap, as a deflecting structure, is supported above the discharge of the fuel pipe and is shaped and arranged to divert the carrier fluid and granulated fuel into the combusting bed. The diverter structure is spaced above the end of the fuel pipe and provided with a configuration on its underside to form a venturi section which generates a low pressure in the stream into which the granules of solid fuel are drawn to lengthen their residence time in the combustion zone of the bed adjacent the fuel pipe.

Abstract: Apparatus for supporting a perforated plate (24) air distributor for a fluidized bed combustion boiler. The plate (24) is supported (26) around its entire periphery, and at given points (42) within its periphery, in such a manner that it is free to expand due to thermal growth in a horizontal direction, while still being capable of supporting a vertical load (12) without sagging, buckling, or being subject to failure.

Abstract: The air-supply system for a fluidized-bed furnace includes two air conduits for the same combustion zone. The conduits feed separate sets of holes in a distributor plate through which fluidizing air flows to reach the bed. During normal operation, only one conduit and set of holes is used, but the second conduit and set of holes is employed during start-up.