Numerical Investigation of Effect of Casting Speed on Flow Characteristics of Molten Steel in Multistrand Tundish

Casting speed is one of the key factors affecting flow characteristics in the tundish. This paper gives a detailed numerical investigation for the effect of casting speed on flow characteristics in a five-strand tundish. Firstly, a quantitative evaluation method of flow characteristics (such as dead region, short-circuit flow and flow uniformity among multiple strands) is proposed. And then, by using the method, the effect of the cases (such as reducing to the same casting speed for each strand, closing one or two strands, etc.) on flow characteristics in the case of reducing throughput is analyzed. The results show that the case of closing strands 2 and 4 has the best flow characteristics, and not only dead region volume is smaller, but also the flow difference among multiple strands is also smaller. Meanwhile, in view of slower flow and bigger dead region near the far-strand of the tundish and large difference for flow characteristics between the far-strand and other strands, the effect of increasing the far-strand's casting speed on improving the overall flow characteristic in the tundish is also analyzed. The results show that, increasing the far-strand's casting speed can significantly reduce dead region proportion and flow difference among multiple strands, and in the case of the same throughput, the short-circuit flow does not change much. In the case of increasing the same throughput, flow characteristics in the tundish for only increasing the far-strand's casting speed are better than that for increasing casting speed of each strand simultaneously.