| 摘要 |
PURPOSE:To expand the range of flow rate at which gas is blown in from the same tuyere and to refine various kinds of steel in a wide range in the same apparatus by blowing in an ordinary-temp. gas under pressure at a high flow rate of a blowing-in gas, and blowing in a gas which is compressed and expanded at a low flow rate. CONSTITUTION:When a low-carbon steel is refined at a high flow rate of the blown-in gas, the gas from a gas generator 2 is boosted by a booster 4, and directly blown into molten metal from a metallic or refractory tuyere 18 having a small-bore tube or narrow slit. When the high-carbon steel is refined at a low flow rate, a sluice valve 30 is closed, and sluice valves 26 and 28 are opened to blow a gas which is previously heated and expanded in a heating device 20 into molten metal from a heat-insulated tank 24 through the bottom-blowing tuyere 18. Various kinds of converter steel ranging from a low-carbon to a high-carbon steel can be efficiently refined in the same apparatus by this method. |
