适合漏斗型薄板坯连铸结晶器三孔水口的水模型优化

 采用1∶1的水模型研究了5种不同底孔直径(16～28mm)的三孔水口下漏斗型薄板坯结晶器内的流场、液面特征和卷渣行为。结果表明：在常规工艺参数下，5种三孔水口下结晶器内钢液的流场都是典型的“双辊流”，且流场稳定；在5种三孔水口下结晶器液面波动都较平稳，且波动范围都在±(3～5)mm之间。5种不同水口下结晶器液面主要发生剪切卷渣，漩涡卷渣很少发生。试验得知：在水口浸入深度280mm，拉速为5m/min时，剪切卷渣发生的钢液临界表面速度是0.32m/s，与文献报道的模型计算值较吻合。在水口浸入深度280mm、拉速为5m/min的条件下，适合薄板坯连铸的最佳的三孔水口的底孔直径为22mm。

Water Model Optimization of Three-Port Submerged Entry Nozzle Feeding a Funnel-Shaped Thin Slab Mold

A full-scale funnel-shaped thin slab water model was built to investigate the fluid flow, meniscus fluctuation and slag entrapping behaviors when it were fed by five three-port submerged entry nozzles (SENs) with various diameters.The results shows that the fluid flow in the present mold is a typical steady “double roll flow” when using these five SENs. Furthermore, meniscus fluctuation is within ±(3-5) mm under regular casting parameters (SEN immersion depth and casting speed is 280mm and 5m/min,respectively). The mode of slag entrapping is mainly entrapment by shear flow, and the vortex-related entrapment hardly occurs. The critical meniscus velocity which cause slag entrapping is determined to be 0.32m/s under the regular casting parameters mentioned above, which agrees well with the calculated value. The optimal bottom-hole diameter for this three-port SEN which is suitable for thin slab casting is 22mm.