OPERATION OF PARALLEL BLASTING WITH THREE HOT BLAST STOVES

PURPOSE:To raise thermal efficiency, by determining the lap ratio which represents the rate of a time capable of parallel blasting with two stoves on the basis of the condition to operate a blast furnace and the effectual amount of heat in hot blast stoves, and controlling each of the hot blast stoves in a range indicated by the lap ratio. CONSTITUTION:In the operation of hot blast stove to parallelly blast three stoves using three hot blast stoves, the lap ratio l which represents the rate of a time capable of parallelly blasting two of them is determined on the basis of the condition to operate a blast furnace and the effectual amount of heat in the hot blast stoves by the formula. A burning time and a blasting time in one cycle of each of the hot blast stoves are adjusted in a range indicated by the lap ratio lto perform parallel blasting for a predetermined time. In the formula, Y is thermal efficiency, Q is the amount of combustion heat (kcal/hr.stove), VB is the amount of hot air (Nm /min), TBCPTB is the specific heat of hot air (kcal/ Nm . deg.C), and TOCTPC is the specific heat of cool air (kcal/Nm . deg.C).