BURNER

摘要

PROBLEM TO BE SOLVED: To provide a burner which yields an NOx reducing effect even in a boiler high in furnace load and in internal furnace pressure like a once-through boiler or the like. SOLUTION: An outer cylinder 2b for supplying secondary air is built up with a fresh air passage 9 to supply fresh secondary air alone and a split gas passage 10 to supply the fresh secondary air and a recirculated gas as combustion exhaust gas recirculated through passages split on the inner circumference side and on the outer circumference side. Both the passages are arranged alternately in the circumferential direction of the outer cylinder. A fuel not burned completely by the primary air is burned by fresh air (fresh air through the fresh air passage 9) blown being split from the outer cylinder 2b or the fresh air and the recirculated gas (the fresh air and the recirculated gas through the slit gas passage 10) to form a split flame. Thus, the effect of efficient heat radiation made from the flame is combined with the effect of combustion obtained by the recirculated gas thereby further reducing NOx effectively. the effect of combustion obtained by the recirculated gas thereby further reducing NOx effectively.