METHOD FOR BLOWING GAS INTO MOLTEN IRON IN STEEL MAKING VESSEL

• Main Authors: FUJII TETSUYA, TAKASHIBA NOBUMOTO, TACHIBANA RINZOU, KATOU YOSHIHIDE, KAKIO YASUHIRO
• Format: Patent
• Language: English
• Published: 09.01.1986
• Subjects: CASTING; CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES; CHEMISTRY; METALLURGY; METALLURGY OF IRON; PERFORMING OPERATIONS; POWDER METALLURGY; PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OFWROUGHT-IRON OR STEEL; TRANSPORTING; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS

PURPOSE:To prevent the erosion of a bottom blowing tuyere consisting of plural pieces of metallic pipes as gas passage holes embedded into a refractory compsn. and to regulate the rate of blowing over a wide range by decreasing the inside diameter of said pipes and using a high-pressure gas. CONSTITUTION:The tuyere 1 disposed in a furnace bottom brike 5 convering the inside of a bottom shell 4 of a converter consists of plural pieces of the stainless steel pipes 2 which have <=3mm. inside diameter and is embedded into a tuyere brick 3 as the common refractory compsn. of the furnace. The bottom end of the pipe 2 is commonly connected to a gas accumulation chamber 6 and is further communicated with a feed pipe 7 for a gas such as inert gas. The gas is blown into the molten iron in the converter by using such tuyere 1 so that the inlet pressure of the tuyere attains >=50kg/cm in at least part of the entire blowing period. The erosion of the tuyere is thus prevented and the service life of the tuyere is extended. Since the flow rate of gas blowing is regulatable over a wide range, the dephosphorization and desulfurization or the blowing metting the purpose such as the improvement of an iron yield is made possible.