JPS57143412A - Humidifying method for blast for blast furnace - Google Patents

Abstract

PURPOSE:To improve the thermal efficiency of a hot stove in particular and to improve a heat energy effect by adding moisture in the state of water drops into the blast to be supplied from the hot stove to a blast furnace thereby humidifying the blast for blast furnaces. CONSTITUTION:When the tuyere level temp. in a blast furnace 7 or the heat level in the furnace 7 fluctuates, an adequate instruction is given to a controller 22 by taking the rate of fluctuations during operation of a blower 1, the moisture content of the atmospheric air, the max. permissible amt. of water tobe added, etc. into consideration. In accordance with this instruction, the water drops in the fine water droplet staate are added through a nozzle 18 installed in a blast pipe 11 into the cold wind 3 which is increased of pressure by the blower 1. The water drops are evaporated in the pipe 11 before they arrive at a hot stove 5 by the sensible heat of the pressure increased blast 3, by which blast air 17 is humidified; at the same time, the temp. of the air 17 is reduced by the degree corresponding to the heat of evaporation of the water drops. Next, the humidified blast 3 is heat exchanged with the air 17 of reduced temp. in a regeneration chamber 14 which is already heated by the combustion heat of fuel 8 for combustion in the furnace 5, whereby it is heated up to the prescribed value and the hot blast 6 is blown through a blast pipe 6 into the furnace 7.