PLANT FOR THERMAL PROCESSING OF SOLID FUELS Russian patent published in 1998 - IPC

FIELD: thermal processing of solid fuels. SUBSTANCE: plant has device 13 for mixing dust-gas flow. One inlet of device 13 through gas duct 12 of combustion products is connected to outlet of cyclone 4. Two other inlets of device 13 are connected, respectively, by means of gas recirculation pipeline 18 with gas duct 17 behind ash collector 16 of waste-heat boiler 15 and through hot air duct 20 with hot air box 21 of air heater 14 of waste-heat boiler. Outlet of device 13 is connected to waste-heat boiler 15. Cleaned flow from cyclone 4 after mixing with noncleaned gas part is directed through gas duct 12 to device 13. Supplied to device 13 is also air heated up to 250-350 C from air heater 14 and a part of flue gases after ash collector 16. As a result of mixing, supplied to waste-heat boiler 15 is flow with temperature of 500-550 C sufficient to produce steam with temperature of 440-450 C. In this case, dust content in flow is not in excess of 450 g/n cu. m with gas recirculation degree of 75%. EFFECT: reduced rate of ash accumulations on tubes of waste-heat boiler and increased operating reliability. 1 cl, 1 dwg