板坯连铸结晶器内渣滴卷入行为研究

Study on the Behavior of Slag Entrapment in Mold for Slab Caster

采用水力学物理模拟的方法，通过统计卷渣发生频率的半定量化方式研究了拉速、水VI插入深度和吹气量对结晶器内剪切卷渣、吹气卷渣以及漩涡卷渣等三种卷渣方式的影响规律，分析了各种卷渣方式产生的位置和条件，并观测了每种卷渣方式下卷人渣滴的冲击深度。结果表明，剪切卷渣是高拉速条件下的主要卷渣方式，受拉速影响最大；吹气卷渣发生在大吹气量低拉速的工况条件下，是由大气泡上浮导致，卷入渣滴的冲击深度较浅，容易上浮；漩涡卷渣的产生主要是由非对称流引起，与工况条件关系不大，卷入渣滴的冲击深度很深，难以上浮。此外，本文还探讨了渣滴冲击深度与水口插入深度之间的关系，并提出了减少卷渣的措施。

The influence of casting speed, immersion depth of nozzle and blowing gas flowrate on three types of slag entrapment in the mold was investigated by using physical modeling ,and the occurrence frequency of slag entrapment was obtained through statistical method.The conditon and position of three slag entrapment modes was analyzed,and then ,the penetration depth of slag droplets was observed.The results show that the slag entrapment caused by shear stress is the main entrapment mode in high casting speed,which is mainly effected by casting speed. The slag entrapment due to gas blowing would occur in casting mdd with low casting speed and high blowing gas flowrate, which is induced by big bubbles, and the slag droplets which are impacted shallower are easy to float. The slag entrapment caused by vortex has something with the asymmetry flow rather than the process parameters, and the slag droplets are difficult to float because of deep penetration depth.In addition, the relation between the penetration depth of slag droplets and immersion depth of nozzle was discussed, and some measures to reduce slag entrapment were also presented.