| 摘要 |
<p>The present invention has been devised to obtain a metallurgical effect by introducing refining gas into a molten metal in a metallurgical vessel and stirring the molten metal sufficiently by convection, and to improve durability of one nozzle or a few nozzles for introducing the refining gas. At a predetermined position of a furnace bottom onto which a ramming mass is provided, a few cylindrical refractory sleeves are disposed close to the upper face of the furnace bottom from the lower portion thereof. In each cylindrical refractory sleeve a gas introducing nozzle, which introduces the refining gas, is disposed in such a manner that it can be drawn out downwardly for replacement. On the gas introducing nozzle, a gas pool formed by packing refractory granules from to 5 mm to 200 mm thick throughout the sleeve is disposed, and a ramming mass having a gas permeability equal to or larger than the ramming mass of the furnace bottom is installed in the sleeve up to its upper end, whereby the refining gas is introduced into the molten metal from the determined position to stir it by convection.</p> |
