| 摘要 |
PURPOSE:To completely prevent the occurrence of unexpected accident as well as smoothen the degassing of molten steel by providing a level detector for molten steel which is capable of detecting the level from the flow rate value of inert gas to be injected into molten steel in ladle to a degassing device for a suction type vacuum refining method. CONSTITUTION:When a degassing tank 3 goes down (or a ladle 1 goes up) and a suction pipe 4 is dipped in molten steel 2 in the ladle 1, the tip opening 7a of an inert gas supply pipe 7 is also dipped in the molten steel concurrently, whereupon the flow rate of gas in the pipe 7 is reduced due to back pressure loading entailed. The condition is detected by a flow rate detector 8, and the level of molten steel is detected by a device 9 on a conversion basis. Thus, a flow rate value range in a molten steel level such that the circulating flow of molten steel between the tank 3 and the ladle 1 can be made most properly is preset. And, the elevator of the tank 3, or the dipping depth of the pipe 4 in the molten steel 2, is controlled in connection with the flow rate value range, Thus, unexpected accidents, such as the separation of the pipe 4 from the molten steel level when the tank 3 is lifted to too high level during the vacuum suction operation, accident resulting from too sharrow of the dipping depth, etc., can be completely prevented. |
