吹氩板坯连铸结晶器内双循环流的形成条件

利用Lagrange两相流模型定量研究了吹氩板坯结晶器内双循环流形成条件,并用水模型检验了数值模拟结果.在此基础上考察了吹氩量、钢流量,结晶器宽度、水口浸入深度以及下倾角度对双循环流形成的影响规律.结果表明:选择与其它工艺参数匹配的吹氩量是保证双循环流型的重要条件,且维持此流型的临界吹氩量随钢流量的增加而增加.当钢液质量流量较大(qm＞2.5 t/min)时,减小结晶器宽度和增加水口浸入深度均有助于扩大临界吹氩量范围,而水口下倾角度对其影响较小;当钢液质量流量较小(qm≤2.5 t/min)时,以上工艺参数的影响均不明显.

The Condition for Formation of a Double-Recirculation Flow Pattern in a Slab Continuous Casting Mold with Argon Gas

The formation of a double-recirculation flow pattern(DRFP) in continuous casting mold will be helpful for the improvement of slab quality. In the present study, the condition for the formation of the DRFP in a slab continuous casting mold with blowing argon gas was quantitively described using the Lagrange multi-phase flow model, and the prediction was validated by the water model. The influences of argon gas volume flowrate, fluid steel mass flowrate, mold width, submergence depth of SEN (Submerged Entry Nozzle) and port downward angle on the DRFP were numerically investigated. The results show that it is important for ensuring the DRFP that the argon gas flowrate matchs the other casting conditions. The critical argon gas flowrate increases with the increasing fluid steel mass flowrate, and the range of argon gas flowrate for keeping the DRFP will be enlarged by decreasing the mold width and increasing the submergence depth of SEN as the fluid steel mass flowrate is more than 2.486 ton/min, nevertheless, the port downward angle of SEN has little effect on it. However, the operation parameters have no significant influence on it as the fluid steel mass flowrate is below 2.486 ton/min.