GB903749A - Improvements in or relating to process for heating and humidifying blast for metallurgical furnaces - Google Patents

Abstract

903,749. Iron manufacture. KOPPERS CO. Inc. May 13, 1960 [Oct.28, 1959], No. 16980/60. Class 72. A method of heating and humidifying the blast for a blast furnace comprises blowing cold blast air through a preheater, heating the preheated blast by burning therein a gas containing a high proportion of hydrogen which forms water vapour in the blast, the remainder of the water vapour being supplied as steam after the blower and before the preheater, and delivering the heated and humidified blast to a blast furnace. As shown, cold air from a blower 42 is supplied to a stove 67 for preheating, steam in the required amount being supplied from a source 53. The preheated air then passes to a heating and humidifying chamber 55 where coke oven gas from a supply 58 is burned to heat the blast to the required temperature and to supply the remainder of the water vapour. Since the oxygen in the blast will be reduced by the combustion of the gas additional oxygen may be supplied from a source 62. Just more or just less than half the water vapour required may be supplied by combustion and control of the quantity supplied may be achieved by varying the temperature of the blast issuing from the preheater, a cooler blast requiring more gas to be burned and thereby adding more water vapour in the chamber 55. A recuperative type of preheater may be used.