| 摘要 |
PURPOSE:To heat easily and inexpensively the molten steel in a ladle and to facilitate secondary refining by charging an exothermic material into the molten metal, blowing inert gas into the ladle from the bottom thereof to stir the molten steel and blowing gaseous oxygen thereto while inducing circulating flow. CONSTITUTION:An exothermic material such as Al, Si or the like is charged from a chute 6 for charging the exothermic material into the molten steel 2 contained in a ladle 1 in the stage of heating up the molten steel 2 prior to its secondary refining. Inert gas such as Ar or CO2 is then charged into the ladle 1 from a porous plug 3 provided in the bottom of the ladle to stir the steel 2 and to disperse uniformly the added exothermic material into the steel 2. While the circulating flow as shown by an arrow is induced in the steel 2 by continuing the blowing of the inert gas, gaseous O2 is blown from an upper immersion pipe 5 immersed shallow roughly just above the plug 3 and is brought into reaction with the exothermic material, whereby the molten steel 1 is heated up. The oscillation by the steel 1 by blowing of the gaseous O2 is minimized. A required freeboard 7 height is sufficient at about 300-500mm.. |
