PURPOSE: To prevent the injury of associated devices owing to a drop of the gaseous pressure in a converter by preventing the abnormal drop of the pressure in the converter in the event of emergency such as tripping of an induced draft fan for waste gas or the like during converter operation by controlling the opening degree of the damper of a dust collector.
CONSTITUTION: The spacing between the skirt 5 of a hood 6 and a converter mouth 3 is decreased and the high-temp. waste gas contg. CO and iron oxide dust is efficiently recovered in the stage of refining a raw material 2 such as molten iron in the converter 1 by blowing of pure oxygen from a top blowing lance 4. The pressure of the waste gas in the converter drops sharply when the oxygen blowing is suspended in order to prevent danger in the event of emergency such as tripping of the induced draft fan 15 for waste gas during the above-mentioned operation. The pressure detected by an oscillator 7 in the converter is therefore fed to a controller 9 by which a change- over device 14 is operated to throttle the opening degree of the damper 10 of the dust collector 13 by an electro-hydraulic controller, by which the flow rate of the suction gas by the fan 15 is sharply decreased with a sharp decrease in the quantity of the gas in the converter and the abnormal drop of the gaseous pressure in the furnace is prevented.
OGATA SEIJI
YOSHIDA TORU
ARIMA KEIJI
TERADA TAKAO
FUJI ELECTRIC CO LTD