METHOD FOR CONTROLLING COMBUSTION IN BLAST FURNACE AIR HEATING FURNACE

摘要

PURPOSE: A combustion control method of a blast furnace is provided to improve thermal efficiency by setting up a reference exhaust gas temperature control value according to such external factors as the change of air temperature. CONSTITUTION: A primary reference exhaust gas temperature and another temperature at a combustion completion point are set up by adding specific temperature values to a minimum exhaust gas value obtained by a correlation equation produced by correlation analysis of minimum exhaust gas temperatures of air heating furnaces and cool air temperatures. Exhaust gas temperature after the primary exhaust gas temperature to the combustion completion point and a ratio of mixed gas amount to exhaust gas temperature is obtained. By using the exhaust gas temperature ratio, amount of mixed gas lately used is obtained. A lately used mixed gas flow rate is obtained by using the lately used mixed gas amount. With the lately used mixed gas flow rate, the combustion in an air heating furnace in a blast furnace is controlled.