桨叶结构对KR脱硫搅拌效果影响的数值模拟

Numerical simulation of effect of blade structure on KR desulfurization stirring

相较于喷吹法,KR机械搅拌法在铁水脱硫稳定性方面具有显著优势。KR铁水脱硫采用的搅拌桨结构不同,其脱硫效果也不尽相同。基于多重参考系法(MRF)模型,对使用不同搅拌桨的流场进行数值模拟,模拟结果与水模型实验结果较为吻合,最大误差为9.20%。模拟研究了传统四叶桨、螺旋三叶桨,双层四叶桨,双层三叶桨叶对铁水及脱硫剂的搅拌效果。结果表明:使用单层三叶螺旋桨的铁水涡旋高度落差最大。使用双层三叶螺旋桨时的底部区域脱硫剂体积分数为7.89%,与传统桨叶和单层三叶螺旋桨相比,分别增加了175.87%和61.22%。在200 t规模的铁水脱硫工业实验表明,与传统四叶桨相比,使用单层三叶桨在深脱硫后铁水中[S]无痕迹率提高10%。

Compared with the injection method, the KR mechanical stirring method has significant advantages in the stability of molten iron desulfurization. Due to the different structure of the stirring blade used in the desulfurization of KR molten iron, the desulfurization effect is also different. Based on the multiple reference frame method(MRF) model, the flow field with different impellers was numerically simulated. The simulation results are in good agreement with the experimental results of water model, and the maximum error is 9.20%. The stirring effects of traditional four-blade impeller and spiral three-blade impeller, double-layer four-blade impeller, double-layer three-blade impeller on the stirring effect of molten iron and desulfurizer were simulated and studied. The results show that the height drop of hot metal vortex with single-layer three blade propeller is the largest. When the double-layer three blade propeller is used, the volume fraction of desulfurizer in the bottom area is 7.89%, which is increased by 175.87% and 61.22% respectively compared with the traditional blade and single-layer three blade propeller. The industrial experiment of molten iron desulfurization in the scale of 200 t-scale hot metal shows that compared with the traditional four blade propeller, the traceless rate of [S] in molten iron after deep desulfurization with single-layer three blade propeller is increased by 10%.