| 摘要 |
PURPOSE:To improve the cleanliness of a molten steel and to improve the quality of a steel ingot by providing a sliding nozzle with a gas feed porous plug between an upper stationary nozzle and long-sized lower stationary nozzle in the bottom of a vessel for a molten steel thereby preventing the solidification of the molten steel in the nozzle with the simple mechanism. CONSTITUTION:The sliding nozzle 53 having a heat resistant porous plug 54 for feeding an inert gas is provided between the upper stationary nozzle 52 and long-sized lower stationary nozzle 56 in the bottom 5 of the vessel for the molten steel. The inert gas is fed through the plug 54 to the inside of the upper nozzle 52 to prevent the solidification of the molten steel while the nozzle 53 is held shut. The nozzle 53 is shifted to allow the molten steel to flow downward from a nozzle hole 53a into the lower nozzle 56 in the stage of tapping, by which the molten steel is cast. The solidification of the molten steel in the nozzle is prevented by the simple mechanism, by which the cleanliness of the molten steel is improved and the quality of the steel ingot is improved. The oxidation is more statisfactorily prevented if the nozzle 56 is brought into tight contact with a pouring pipe 6. |
