浇注钢包环出钢口四孔透气塞吹氩控制下渣工艺

Controlling slag carry-over in teeming ladle by argon blowing process with four plugs installed around tapping hole

针对浇注钢包环出钢口四孔透气塞吹氩控制下渣工艺,建立了某钢厂130 t钢包三维DPM-VOF耦合数学模型以计算浇注钢包下渣过程,并通过冷态实验验证了该模型的有效性。利用该模型研究了不同偏心率对下渣行为的影响,揭示了该工艺控制下渣的行为规律,并分析了吹氩流量对控制下渣的影响。结果表明,随着偏心率的增大,不同浇注高度下的最大切向速度减小,汇流漩涡临界高度降低。环出钢口四孔透气塞吹入氩气后,气泡流股的汇聚有效地减弱了水口上方钢液的周向旋转速度,大幅降低了汇流漩涡下渣临界高度。4个气泡流股的气液两相流会抑制流向水口钢液的径向流动速度,由排流沉坑引起的下渣也得到明显抑制。随着吹氩流量的增加,下渣临界高度呈降低趋势。就本研究而言,控制下渣的最佳吹氩流量为30 L/min。

A 3 D DPM-VOF coupled mathematical model of a 130 t ladle was established to study the controlling slag carryover behavior in teeming ladle by argon blowing process with four plugs installed around tapping hole. The validity of the model was verified by cold experiments. The effect of eccentricity on slag carryover was investigated, and the law of controlling slag carry-over under the process was revealed by the mathematical model. The effect of argon flow rate on controlling the slag carry-over was also analyzed. The results show that, with the increase of eccentricity, the maximum tangential velocity under different teeming heights decreases, therefore the critical height of vortex also decreases accordingly. With argon injected into the ladle via four plugs installed around tapping hole, the aggregation of bubble flow strand effectively weakens the tangential velocity of molten steel above the nozzle, which reduces the critical height of vortex. The gas-liquid two-phase flow from four bubble streams can restrain the radial velocity of the molten steel toward the nozzle, so the slag carry-over caused by drain sink can also be restrained obviously. With the increase of argon flow rate, the critical height of controlling slag carry-over is reduced. And the optimal argon flow rate for controlling slag carry-over is 30 L/min for the ladle.