LCAK钢CAS精炼过程的物理模拟

Physical modeling of CAS refining processes for LCAK steel

针对CAS精炼过程中罩外有大量气泡溢出的问题,在相似性原理的基础上建立了CAS钢包的水模型.研究了CAS精炼过程中底吹气量、浸渍罩插入深度和不同底吹位置对钢包混匀时间的影响.实验发现:浸渍罩的中心与底吹气孔的中心同轴时,能有效地防止罩外气泡溢出.对于300 t钢包,底吹方案优化后,底吹位置选在距钢包中心0.3r～0.4r(r为钢包底部半径),精炼时底吹气量为600 L·min-1,排渣时底吹气量选在500 L·min-1左右,浸渍罩浸入深度选为180～225 mm.工业试验表明,优化后的底吹方案有效地解决了罩外气泡溢出的问题,并且提高了LCAK钢液的洁净度和可浇注性.

Based on the similarity principle, a water model was established for the problem that a large number of bubbles overflow from the submerged tube in the CAS process. The effects of the flow rate of bottom gas, the submerging depth of the submerged tube and the nozzle position on the mixing behavior of liquid steel were studied. It is found that the problem of bubble escaping can be resolved when the hood eenter and the bottom nozzle center are coaxial. For a 300 t ladle, the optimal bottom blowing process was obtained. The optimal position of bubbling is 0. 3r to 0. 4r （r is the ladle bottom radius） away from the ladle bottom center, the flow rate of bottom blowing is approximately 600 L. min^-1 in the refining process and 500 L. min^-1 in the deslagging process, and the immersion depth of the submerged tulle is 180 to 225 mm. Industrial tests show that the improved bottom blowing process can effectively prevent bubbles from overflowing, and improve the cleanness and castability of the LCAK steel.