| 摘要 |
PURPOSE:To shield the pouring flow of a molten steel from outdoor air and to thoroughly prevent nitrogen absorption by delineating the flow of the molten steel to be poured from a nozzle in the bottom of a ladle from the external atmosphere and blowing an inert gas to the molten steel flow on the surface of the molten steel in a tundish. CONSTITUTION:The top end 12 of the nozzle in the bottom 10 of the ladle is enclosed by a sealing hat 24 and a cylindrical pouring pipe 16 and is thereby shielded from the outdoor air. The top end part of the partition wall consisting of the sealing hat 24 and a pouring pipe 16 is hermetically sealed by a conical cap part 18 integrally constituted with the nozzle of the ladle. The bottom end of the pipe 16 is immersed into the molten steel in the stage of operation and is thus shielded from the external atmosphere. On the other hand, at least one inert gas guide pipe 20 is embedded into the partition wall part for shielding the outdoor air and an ejection port 22 is opened toward the falling molten steel flow. The effect of preventing the nitrogen absorption is obtd. at any angle of the port 2 as far as the angle is within an h<=0.5H range. |
