METHOD FOR COMBUSTION WITH LOW NOX OF PULVERIZED COAL AND COMBUSTION BURNER

摘要

PURPOSE:To improve a combustion characteristic and make a substantial reduction of an amount of applied auxiliary liquid fuel when a load is varied by a method wherein an auxiliary flame is formed in a low NOX combustion burner for pulverized coal. CONSTITUTION:A pulverized coal nozzle 1 for use in injecting pre-mixture 5 of pulverized coal and primary transmitted air is arranged at a central part of a burner, and a nozzle 4 for injecting pre-heated liquid fuel 8 is arranged within the burner. A gas fuel nozzle 12 for injecting the pre-mixture gas of gaseous fuel 13 and combustion air 14 is arranged around an outer circumference of the pulverized coal nozzle 1, and then a secondary air nozzle 2 and a third air nozzle 3 are arranged around the fuel nozzle 12. After preheating of a combustion device under combustion of liquid fuel 18, pre-mixture 5 is fed from the pulverized coal nozzle 1 so as to form a pulverized coal flame. After this operation, premixed gaseous fuel 13 and combustion air 14 is fed so as to form a pilot flame around an outer circumference of an extremity end of the pulverized coal nozzle 1 and to keep a flame holding effect.