| 摘要 |
PURPOSE:To restrain erosion of tip of a nozzle by constricting a fine carbon blowing nozzle of a double tube and blowing a fine carbon from an internal tube with carrier gas mixing the specified amount of oxygen with inert gas and blowing gas for cooling a nozzle from an external tube. CONSTITUTION:Fine carbon materials are fed from an upper part or a side surface of a molten iron to the molten iron charged in a vessel with a bottom blowing nozzle. The fine carbon blowing nozzle is composed of a double tube. Carrier gas mixing 5-25% oxygen in the inert gas, such as Ar, N2 is blown with the fine carbon into the molten iron from the internal tube of the nozzle. From an external tube, inactive gas, such as Ar, N2 and the like, weak acid gas, such as CO2, H2O2 and the like and hydrocarbon gas, such as propane and the like are blown as gas for cooling the nozzle. |
