顶旋型湍流抑制器对单流板坯中间包内湍流行为的影响

Effect of top-swirling turbulence inhibitor on flow behaviors of a single-strand slab casting tundish

设计了一种顶旋型湍流抑制器,使钢液产生旋转流场,降低钢/渣界面速度,促进夹杂物的去除,达到净化钢液的目的,并利用数值模拟的方法,对单流板坯中间包在稳态和非稳态时的流场进行研究。结果表明:使用新型抑制器相较于不使用和使用普通抑制器,对中间包稳态浇注流场有明显的改善,死区体积明显减小。拉速和中间包容量改变时,新型抑制器比普通抑制器对中间包液面波动的抑制效果更好。当拉速为1.15、1.55和1.85 m/min时,使用新型抑制器的中间包自由液面的平均速度分别为0.040、0.053和0.062 m/s,相较于普通抑制器分别降低了21.6%、24.3%和26.2%。当中间包容量为40、30和25 t时,使用新型抑制器相比于普通抑制器,自由液面的湍动能分别减少了20.9%、25.0%和26.3%。

A top swirl turbulence inhibitor(TI) was proposed to further enhance the cleanness of liquid steel in the tundish, through which the swirling flow field can be formed above the TI, the flow velocity at steel/slag interface can be reduced, and the removal floatation rate of non-metallic inclusion can be enhanced at the same time. The steady-state and transient flow fields of a single strand slab tundish were studied by numerical simulations. The results show that the novel TI can significantly improve the flow field of tundish at steady-state casting and reduce the volume of dead zone compared to the cases without TI and with the ordinary TI. When the casting speed and tundish capacity are changed, the novel TI has better suppression effect on the tundish liquid level fluctuation than the ordinary TI. When the casting speed is 1.15, 1.55, and 1.85 m/min, the free surface velocity under the novel TI are about 0.040, 0.053, and 0.062 m/s, respectively, which is reduced by 21.6%, 24.3% and 26.2% compared with the ordinary TI. Meanwhile, when the tundish capacity is 40, 30 and 25 t, the turbulent kinetic energy at free surface is reduced by 20.9%, 25.0% and 26.3% compared with the ordinary TI.