PRESSURE EQUALIZING METHOD OF BLAST FURNACE TOP RESSURE EQUALIZING CHAMBER

PURPOSE:To prevent the abrasion of apparatus parts such as upper bells in accordance with the discharging of raw materials by adding tertiary equalizing pressure in the pressure equalizing in the top part of a two bell type furnace. CONSTITUTION:Part of the gas half cleaned from the gas in a furnace 7 is conducted through a pressure equalizing pipe 11 into an upper bell hopper (pressure equalizing chamber) 3, whereby a primary pressure equalizing is accomplished. The gas in the furnace 7 then is conducted through a pressure equalizing pipe 12 into the chamber 3, whereby a secondary pressure equalizing is accomplished. A lower bell hopper 5 and the inside of the furnace 7 are communicated with a pressure equalizing pipe. A secondary pressure equalizing valve 17 is then closed, and a tertiary pressure equalizing valve 21 and a pressure regulating valve 22 are opened to be ready for introduction of gaseous nitrogen or the like through a tertiary pressure equalizing pipe 20 into the chamber 3. Thereafter, an upper bell 4 is opened to charge raw materials A immediately or after a constant time, and gaseous nitrogen or the like is introduced so as to maintain the presure in the chamber 3 (equal to the furnace top pressure) in accordance with the discharging from the chamber 3 in the raw materials A. Then, the abrupt ascending of the rough gas along the slope 4' of the upper bell 4 is obviated and the abrasion of apparatus, devices, etc. is prevented.