METHOD FOR RECOVERING GAS DURING DEPHOSPHORIZATION OPERATION IN CONVERTER EXHAUST GAS TREATMENT FACILITY FOR DECARBONIZATION BLOWING, AND DEVICE FOR CONTROLLING PRESSURE INSIDE FURNACE

PROBLEM TO BE SOLVED: To recover an evolved gas so as to be used as a valuable gas in an as-unburnt state, without increasing an amount of blowing oxygen or an auxiliary material, which are prescribed according to the dephosphorization operation, namely without charging a new material into a converter for an increased amount of the evolved gas, by accurately controlling a pressure inside the furnace during a dephosphorization operation in a converter exhaust gas treatment facility for decarbonization blowing. SOLUTION: The method for recovering the gas in the as-unburnt state comprises: closing and completely water-sealing at least one of furnace pressure control dampers which are variable throat type venturi scrubbers provided with several secondary dust catchers, to close the gas evolved from the converter, when carrying out the dephosphorization operation in the converter exhaust gas treatment facility for decarbonization blowing; and controlling the pressure inside the furnace with the furnace pressure control dampers which are not water-sealed. COPYRIGHT: (C)2004,JPO