| 摘要 |
PURPOSE:To improve the insufficient agitation of a steel bath and to accelerate the secondary combustion of CO by top blowing O2 to the molten steel from a lance nozzle provided with a subnozzle on the lateral side of a main nozzle and bottom blowing an agitating gas through tuyeres provided below the steel bath level of a furnace body. CONSTITUTION:The angle theta of the above-described subnozzle 2 is set larger than the angle of a main nozzle 1, and the extension line of the hole of the nozzle 2 is located nearer the centerline C side of the furnace body than the boundary between the surface of the molten steel in the furnace and the furnace wall. On the other hand, tuyeres 3 are provided between the circle that the points of intersection of the extension lines of the O2 jets from the main nozzle 1 and the furnace bottom draw and the circle that the points of 1/2 the distances from said circle up to the inside circumference of the furnace wall draw. O2 is top blown through the nozzle 1 and the nozzle 2 and an agitating gas is bottom blown through the tuyeres 3 by the above-mentioned constitution. As a result, the gaseous CO generated during decarburization is burned positively to CO2 and the heat level in the furnace is increased. |
