FLUIDIZED BED COMBUSTION FURNACE

摘要

A fluidized bed combustion furnace comprising a throttle section (12) formed directly above a fluidized bed (18) so that the flow velocity of combustion gas in the throttle section becomes higher than the terminal velocity of grains or particles of a fluidizing medium which have a mean diameter, secondary air supply ports (22) provided in the throttle section in a plurality of stages, a free board section (13) formed above the throttle section, the free board section having such a cross-sectional area that the gas flow velocity becomes lower than the terminal velocity of mean diameter grains or particles of the fluidizing medium, two or more combustion gas inlets (16a) and (17a) of combustion gas passages (16) and (17) provided in an area of the ceiling portion of the free board section which is not coincident with the plane of projection of the throttle section, and a junction chamber (25) provided at the outlets of the combustion gas passages so that high-temperature gases passing through the combustion gas passages collide and merge with each other in the junction chamber.