水口出口形状对高拉速板坯连铸结晶器内流场特征的影响

采用1∶1的水力学模型研究了浸入式水口出口形状(椭圆形、矩形、方形)对结晶器自由液面特征、流股特征与流场的影响。在通钢量为3.20和4.48t/min时,结晶器液面波动与表面流速都遵循椭圆形水口矩形水口方形水口的变化规律。椭圆形水口的流股为"旋转流股",流股扩展角和倾角最大,流股分散,且在出口处流速分布均匀;方形与矩形水口流股为"平滑流股",方形水口流股的扩展角和倾角最小,流股集中在出口偏下半部分处;矩形水口流股扩展角、倾角、流股分散与均匀程度居中。综合考虑:在高拉速条件下(通钢量为4.48t/min),椭圆形水口条件下结晶器液面的平均波高为5.5mm,表面流速为0.32m/s,仍然有提高拉速的空间,且流股速度在出口处分布均匀,所以较优的水口出口形状为椭圆形。

Effect of Port-Shape Design on Fluid Flow in High-Speed Slab Continuous Casting Mold

Full scale water model experiments were conducted to investigate the effect of port shapes, oval port, rectangular port and square port, on free surface, jet characteristics and fluid flow in the mold. The results show that the order of increasing level fluctuation and meniscus velocity is from oval port, rectangular port to square port at the flow flux of 3. 20 and 4. 48t/min. Generating the largest jet-spread angle and jet-discharge angle, the oval-port jets are swirling, scattered and uniformed. Generating the smallest angles, jets from the square port are smoothing and concentrated at the bottom of the port. Nevertheless, the rectangular-port ones have moderate angles and distribution with smoothing jets. Consequently, the oval port is superior in high-speed casting with even-distributed jets, average level fluctuation of 5. 5mm and the average meniscus velocity of 0. 38m/s which leaves space for the improvement of casting speed in production.