| 摘要 |
PURPOSE:To obtain conditions for fluctuations of gaseous pressure by which the highest refining effect of molten steel is obtained by detecting continuously the gaseous pressure in a cylinder which stirs the molten steel by scooping up and discharging of the molten steel and controlling the fluctuation width thereof to >=800mm.Hg. CONSTITUTION:Pipings 3, 4 for pressurizing, and decompressing and evacuating are connected to the top end of a refractories-made cylinder 2 which is immersed at the bottom end part in treating molten steel 1 tapped into a vessel such as ladle for the purpose of secondary refining. The pipe 3 is connected to a high pressure gas source through a solenoid stop valve 5, a flow rate controlling valve 6, a tank 7, and a reducing valve 8. On the other hand, the pipe 4 is connected to a decompressing the evacuating pump 11 through a solenoid stop valve 10. When the valves 5, 9 are opened and closed alternately for a prescribed time with a controller 12, the gaseous pressure in the cylinder 2 repeates pressurizing and decompressing, and the molten steel 1 is discharged and sucked. The gaseous pressure in the cylinder 2 is detected continuously with a detector 13, and the valves 6, 10 are so cntrolled by the device 12 that the fluctuating width thereof attains the set value above 800mm.Hg. |
