Patent ID: 6604474
Filing Date: 2003-08-12
Classification: F23C,F23D,F23K,F23L

Abstract:
A method of decreasing concentration of nitrogen oxides and carbon loss in a combustion flue gas comprising:a) providing a boiler having a combustion zone; b) providing a plurality of burners in a lower level of said combustion zone and one or more burners in an upper level of said combustion zone; c) injecting combustible solid fuel and an oxidizing agent into said plurality of burners in the lower level of said combustion zone; d) partially gasifying solid fuel particles in a duct upstream of said one or more burners in said upper level of said combustion zone by mixing the solid fuel particles with recycled flue gas at a temperature of 600-900Â° F.; and e) injecting the partially gasified solid fuel into at least one of said one or more burners in said upper level of said combustion zone.