40t单流中间包控流装置的优化配置

Optimization of flow control devices in a 40-t single strand tundish

采用水模型和工业验证的方法针对40 t单流中间包的控流装置进行优化配置研究.通过对单独湍流抑制器控流装置、湍流抑制器+下挡墙组合控流装置、湍流抑制器+下挡墙+上挡墙组合控流装置的研究表明,下挡墙在改善钢液流动形态和减少中间包内死区方面所起的作用大于上挡墙.平均停留时间随下挡墙与长水口的距离增加呈先增大后减小的趋势.确定了单流中间包以湍流抑制器+下挡墙的优化组合形式,死区比例由原来的25.9%降低到了13.6%.通过系统取样分析发现优化后中间包内T.O和N含量大幅降低,正常坯中的大型夹杂物质量分数也由原来的8.4×10-7降低到3.2×10-7.

An optimization of flow control ＂devices in a 40-t single strand continuous casting tundish was carried out by water mod- eling experiments and industrial experiments. Three cases were considered during the experiments, i. e, tundish equipped with a turbulence inhibitor, tundish equipped with a turbulence inhibitor and dams, and tundish equipped with a turbulence inhibitor, dams and weirs. The results show that the dams play a much more important role than the weirs in improving the fluid flow characteristics and decreasing the dead volume fraction in the tundish. The average residence time increases firstly and reduces afterward with increasing distance between the dam and nozzle. The tundish equipped with a turbulence inhibitor and dams is the optimized according to these results, and the dead volume fraction reduces to 13.6% from 25.9%. The results of industrial application shows that the T. O and N contents reduce greatly and the mass fraction of macro inclusions in normal slabs reduced to 3.2×10 ^-7 from 8.4 × 10^-7.