FLUIDIZED-BED COMBUSTION AND GASIFICATION FURNACE Russian patent published in 2004 - IPC

FIELD: furnaces for recovering black coal of various grades. SUBSTANCE: proposed fluidized bed furnace assembled of integrated combustion and gasification furnaces that functions as fluidized-bed coal-fired boiler designed for burning various grades of black coil without redesigning its heat-transfer surfaces, that is, without redesigning the boiler, is divided by means of plurality of partitions into gasification furnace, main combustion chamber, and heat recovery chamber; mentioned gasification furnace and heat recovery chamber are fully isolated from one another. Return fluidized medium flow is produced in at least one of mentioned gasification furnaces and in main combustion chamber; intensive fluidization zone is produced in this flow so as to ensure high fluidization speed in fluidized bed of particular zone thereby generating fluidized medium upflow; weak fluidization zone is produced in fluidized bed so as to ensure low fluidization speed in fluidized bed thereby producing fluidized medium downflow. Circulating fluidized medium flow is produced between gasification furnace and main combustion chamber. Circulating fluidized medium flow is also produced between heat recovery chamber and main combustion chamber. EFFECT: enhanced furnace efficiency, reduced amount of polluting wastes. 84 cl, 16 dwg