BOILER FOR BURNING CLINKERING COAL Russian patent published in 2003 - IPC

FIELD: boilers for burning clinkering coal having low-melting point ash. SUBSTANCE: proposed boiler has T-shaped arrangement and is provided with furnace, opposing burners arranged in two tiers, dust system with mills, heating surfaces at furnace outlet which are made in form of slag screen and convective steam super-heater located in horizontal gas duct; mills are hammer-type and burners are vortex-type; dust system includes centrifugal separators; moisture traps mounted between centrifugal separators and vortex burners ensure 50 to 90% separation of used drying agent due to use of rotary motion of dust-gas-air mixture in centrifugal separators. Separated part of drying agent is directed to furnace zone located higher than level of second tier of vortex burners by 1-4 m. Boiler is provided with recirculating gas exhausters taking gases at temperature of 500-700 C for additional gas-and-air drying; it is also provided with shields with heat-insulating coat on their surfaces over perimeter of furnace; it projects by 0.5-1 m from edges of first and second tiers of vortex burners. Mounted in upper portion of furnace are additional heating surfaces made in form of separate shields to ensure required temperature level of slag-free operation of convective steam superheater not higher than 900 C. EFFECT: enhanced operational reliability. 5 cl, 1 dwg