| 摘要 |
<p>PURPOSE: To transfer the heat at a firing point on the upper surface of a slag to a metal by the shortest distance and the shortest time, by combining a top-blowing lance with plural steps of side-blowing tuyeres in a refining furnace at the optimum condition and developing circulating flow in the slag from the center point of the furnace to a furnace wall side. CONSTITUTION: In a top-blowing or a top-bottom combined blowing converter 1, carbonaceous material as heat source is charged and oxygen is blown onto the molten slag 4 from the top-blowing lance 6 to melt a steel scrap with the combustion heat of this carbonaceous material. Further, in the side-blowing tuyeres 5, 7 arranged in two steps in the furnace wall, the gaseous oxygen from the tuyeres 5 at the upper side is blown in an almost horizontal direction, and the gaseous oxygen from the tuyeres 7 at the lower side is blown into the slag layer toward the tuyeres 5 at the upper side while increasing gas flow rate. Further, inert gas, etc., are blown in from bottom blowing tuyeres 2 to stir the molten iron 3. By this method, the slag 4 is turned from the furnace wall side of the slag surface layer to the center side to develop the circulating flow, and the heat of the firing point obtd. from the top-blowing lance 6 is transferred to the molten iron 3 and the heat conductive efficiency is improved.</p> |
