Process for operating a plurality of regenerative hot blast stoves for

Abstract

A plurality of regenerative hot blast stoves are operated under a staggered-parallel process wherein each stove is alternately operated under a fixed heating cycle wherein no cold blast is supplied to the stove and no hot blast issues therefrom and a fixed blasting cycle wherein cold blast is supplied to the stove and issues therefrom as hot blast. The initiation of the cycles of the stoves is staggered in time with respect to each other such that at any given time hot blast issues from more than one of the stoves but at different temperatures. The temperature of the hot blast issuing from the stoves is regulated to a predetermined temperature required at the blast furnace in a two-stage operation including a first stage wherein relatively cooler and warmer hot blast issuing from those stoves operating under blasting is mixed and controlled as a function of a first reference temperature greater than the temperature required at the blast furnace, and a second stage wherein cold blast is admixed with the hot blast mixture and controlled as a function of a second reference temperature equal to the temperature required at the blast furnace. Upon a lowering of the second reference temperature due to an operating requirement of the blast furnace, the first reference temperature is raised, whereby the second stage temperature regulation overlaps the first stage temperature regulation.