The multiphase flows involving steel—slag—air phases in a two-strand tundish during ladle change are investigated using mathematical modeling. Experimental results from water modeling are used to validate the simulated results. Tundish cover powder (TCP) and steel samples are taken from eight heats in one sequence to evaluate the effect of the multiphase flows during ladle change on the composition of the TCPs and steel cleanliness. Furthermore, the effect of the refilling time on the air entrainment and slag aperture during ladle change is analyzed and discussed. It is found that the strong turbulent flows in the tundish impact zone during ladle change promote the mix of the two-layer cover powder, which consists of a basic TCP layer at the bottom and a top layer of rice hull balls. It results in a significant change in the composition of the TCPs and gradually deteriorates the steel cleanliness by the slag—steel reaction. Increasing the refilling time can effectively decrease the amount of entrained air and area of slag layer aperture in the tundish bath during ladle change. To reduce the steel reoxidation during ladle change, the refilling time should be larger than 184 s. Moreover, a new TCP is developed instead of the top layer of rice hull balls in industrial production. The use of the new TCP significantly improves the steel cleanliness in the tundish.

中文翻译：

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换包操作和中间包盖粉对连铸中间包钢清洁度影响的研究

使用数学模型研究了钢包更换期间双流中间包中钢-渣-空气相的多相流。水模拟的实验结果用于验证模拟结果。中间包覆盖粉末 (TCP) 和钢样品从一个序列中的八个炉次中取出，以评估钢包更换期间多相流对 TCP 组成和钢清洁度的影响。此外，分析和讨论了换包过程中补料时间对空气夹带和渣孔的影响。结果表明，更换钢包时中间包冲击区的强烈湍流促进了两层覆盖粉的混合，该覆盖粉由底部的基本TCP层和顶层的稻壳球组成。它导致 TCP 的组成发生显着变化，并通过渣-钢反应逐渐降低钢的清洁度。增加再充填时间可以有效减少更换钢包时夹带的空气量和中间包槽内渣层孔的面积。为减少换包过程中钢的再氧化，补水时间应大于184 s。此外，开发了一种新的TCP来代替工业生产中的稻壳球的顶层。新 TCP 的使用显着提高了中间包中钢材的清洁度。为减少换包过程中钢的再氧化，补水时间应大于184 s。此外，开发了一种新的TCP来代替工业生产中的稻壳球的顶层。新 TCP 的使用显着提高了中间包中钢材的清洁度。为减少换包过程中钢的再氧化，补水时间应大于184 s。此外，开发了一种新的TCP来代替工业生产中的稻壳球的顶层。新 TCP 的使用显着提高了中间包中钢材的清洁度。