METHOD FOR CONTROLLING TEMPERATURE OF FURNACE TOP GAS IN BLAST FURNACE

PROBLEM TO BE SOLVED: To avoid the lowering of electric power output and the burning of a filter cloth in a dry type dust collector by pretermining the starting temps. of spraying water by dividing the time into the charging time of ore and the term except this charging time, starting the spraying water at the stage which the temp. with a furnace top gas thermometer reaches the starting temp. of the spraying water, and stopping the spraying water at the stage which the temp. becomes lower than the starting temp. of spraying water. SOLUTION: After introducing the furnace top gas in a blast furnace 1 into the dry type dust collector 2 and removing the dust therein, this gas is fed to the power generator 3. Since the heat resistant temp. of the filter cloth 4 for dust collector is lower in comparison with the max. value of the furnace top gas, the temp. control of the furnace top gas is executed by using the furnace top gas thermometer and a spraying water nozzle at the furnace top 8. The spraying water is started at >=200 deg.C, that is the temp. of the furnace top gas except the charging time of the ore. At the charging time of the ore, since this gas temp. is lowered with the charging, the spraying water is started at >=240 deg.C. In the case that the furnace top gas temp. rises by slippage, blow-off, reduction of blasting, etc., the spraying water quantity is decided from the gas speed measured with a furnace top gas flow meter 6. The power generated output can be increased by reducing the variating width of the furnace top gas temp. and raising the average gas temp.