| 摘要 |
PROBLEM TO BE SOLVED: To generate reducing gas satisfying a suitable gas composition and temp. to the production of reduced iron and tom improve the efficiency by using the generating gas in a gas current coal gasificating furnace to the reduction, applying dehydrating treatment and/or decarbonating treatment to a part of off-gas in a producing apparatus and circulating the gas in the gas current coal gasificating furnace into a cooling furnace. SOLUTION: In the cooling furnace 10, radiation boiler is not arranged and a cooling furnace gas nozzle 16 is positioned at the lower part of the cooling furnace 10 and a high temp. gas at e.g. 1600 deg.C is rapidly cooled to 700-900 deg.C. This gas is used to the reduction of ore in a reduced iron producing apparatus 2 and treated from a heat recovery device 3 to a decarbonating device 7 in order and supplied into a nozzle in the cooling furnace. A part of the off-gas is branched from the inlet of the decarbonating device 7 and supplied into a gas nozzle 18 in the gasificating furnace. Carbon dioxide gas contained in the gas is reacted with C in the coal and worked as oxidizer and the gas to be supplied into the gasificating furnace with endothermic reaction can be reduced. A heating device for circulating gas needed for the reduced iron production and fuel therefor are unnecessary and the radiation boiler can be omitted. |
