METHOD AND DEVICE FOR BURNING SOLID FUEL Russian patent published in 2003 - IPC

FIELD: gas- turbine engines; furnaces and thermal power plants; utilization of domestic and industrial wastes. SUBSTANCE: fuel is fed to furnace for thermal decomposition; then, fluidized bed is formed and fuel is subjected to thermal decomposition; products of thermal decomposition are fed to twisted air flow and is burnt at simultaneous separation of ash. Thermal decomposition process is performed at two stages. At first stage, heating and partial thermal decomposition are effected beyond fluidized bed. At second stage, final thermal decomposition is performed and burning in fluidized bed is made formed by twisted air flow, pyrolysis gas and particles of gasified fuel which are sucked from zone of escape of products of first stage by twisted air flow. Beginning of second stage of thermal decomposition process is performed in central part of vortex flow in plane of its formation. Combustion products of first stage at air excess coefficient lesser than one form continuation of air flow. Second stage of burning of gaseous products of thermal decomposition process is effected due to delivery of active air to passive mixture of thermal decomposition products sucked after first stage. Third stage of burning is performed in twisted flow of combustion products formed by high-temperature and high-velocity flow of combustion products escaping after second stage of burning. Device proposed for realization of this method includes bin for loading fuel, furnace for thermal decomposition of solid fuel with outlet hole at the top, unit for forming fluidized bed, cyclone-type furnace with inlet hole at the top; in the center there is hole for outlet of combustion products and holes for escape of ash is provided in lower portion; device is also provided with vortex chamber having ejector and air source. Furnace for thermal decomposition of fuel is circular in shape. Retort mounted coaxially inside furnace at end clearance relative to its bottom and is connected with bin in its upper part. Lateral surface of said retort is provided with holes connecting its interior with working space of circular furnace; unit for forming fluidized bed is located in lower portion of furnace; it is made in form of blade tangential swirler; upper outlet hole is connected with inlet of vortex combustion chamber whose outlet is connected with interior of furnace; ejector is connected with air supply source. EFFECT: enhanced efficiency; reduced emission of toxic agent; improved ecological characteristics. 3 cl, 2 dwg