| 摘要 |
PURPOSE:To provide a removing device for base metal which melts away quickly and surely the base metal stuck to the inside circumferential wall surface of a treating vessel for molten metal by providing a gas diverging member in the gas jection part of a long-sized lance and a gas ejecting hole having the special construction between the same and the bottom end surface thereof. CONSTITUTION:The base metal S sticking to the inside wall 2b of an RH type vacuum degassing vessel 2 during the treatment of molten steel is melted away while the treatment of the molten steel in the vessel 2 is in pause. More specifically, a long-sized lance 8 is moved downward along a vertical moving guide 5 so as to be inserted 4 into the vessel 2 and when a gas ejecting part 14 arrives at the top end position of the metal S, a motor 6d is run at a low speed and gaseous O2 is ejected horizontally and radially from the ejection port EX of the ejection nozzle 14. As a result, gaseous fuel and the gaseous O2 are bombarded uniformly against the entire circumferential surface of the metal S, and the metal S is melted away successively from the upper part to the lower part. When the ejecting part 14 arrives at the bottom end position thereof, the low speed driving of the motor 6d and the supply of the gaseous O2 through the pipe 13 are stopped. |
