| 摘要 |
<p>PURPOSE:To remove efficiently the harmful gas and impurities contained in a molten steel in a short period in the stage of blowing an inert gas into the molten steel and removing the harmful gas therefrom by heating the molten steel by a plasma torch and using the inert gas of a high temp. CONSTITUTION:The harmful gas such as oxygen or nitrogen is absorbed and contained in the molten steel 3 which is melted and refined in the atmosphere and therefore the molten steel is put into a ladle furnace 1 and the inert gas is supplied by a plasma torch 7 into the furnace and is blown as high temp. gaseous plasma onto the molten steel 3, by which the molten steel is heated. The inert gas or gaseous hydrogen heated to 5,000-10,000 deg.C is supplied at the same time by a plasma torch 12 to a mixer 11 and is mixed with the low- temp. inert gas from an inlet pipe 21. The gaseous mixture is heated up to approximately the temp. of the steel 3 and is blown by a lance 9 into the molten steel 3. The molten steel 3 is stirred by the inert gas without being cooled, by which the harmful gas is released therefrom and the impurity is removed as slag 4.</p> |
