连铸钢包浇注过程中旋涡的形成机理

连铸钢包浇注末期出现的旋涡卷渣现象会对连铸钢水质量产生重要的影响，为了有效控制生产中的旋涡卷渣现象，对钢包浇注末期旋涡的产生机理开展详细研究.依据相似原理，构建了相似比为1∶6的钢包物理模型，对钢包浇注过程中旋涡产生及卷渣过程进行研究，分析了初始液面高度、出水口尺寸与布置位置、出水口结构等因素对旋涡形成规律的影响.结果表明：旋涡形成过程与初始液面高度无关；钢包出水口尺寸和布置位置对于旋涡形成过程影响显著.随着出水口直径的增大，旋涡临界高度逐渐增加；随着偏心率的增加，旋涡临界高度逐渐降低，最佳偏心率为3/4.提出三片挡块式出水口结构，可以显著降低钢包浇注末期的旋涡临界高度，降低高度达50％左右.

Mechanism of vortex formation in teeming ladle during continuous casting process

Cleanness of molten steel in tundish was closely related to the slag entrapment by vortex at end of ladle teeming process.The formation mechanism of the vortex was investigated in order to develop effective measure-ment to prevent its negative effect.Based on the similarity criteria,series water modeling experiments,with scale of 1∶6,were carried out to investigate the formation and evolution mechanisms of vortex in ladle during teeming process.The effects of initial level of fluid in ladle,exit diameter and location,exit structure on formation mecha-nism of the vortex were studied.The results show that,under the present experimental conditions,the vortex for-mation has no relationship with the initial level of fluid in ladle,nevertheless,the exit diameter and location play an important role in vortex evolution.The critical height of vortex formation decreases with decreasing exit diame-ter and increasing exit eccentricity,and the best value of exit eccentricity is 3/4.A new exit structure is developed which dramatically delays the formation of vortex at the end of teeming process by 50%.