Effect of Mold Oscillation on Multiphase Flow and Slag Entrainment in a Slab Continuous Casting Mold

Abstract

In the current study, a three-dimensional mathematical model that integrated the large eddy simulation (LES) turbulent model, volume of fluid (VOF) multiphase model, and the dynamic mesh model, was developed to investigate the influence of the mold oscillation on the steel, slag, and air multiphase flow and the slag entrainment in a slab continuous casting mold. The results indicated that the mold oscillation led to an increase of about 0.35 m/s in the speed of molten steel at the impact point of the upper and lower circulation on the narrow surface. However, it reduced about 0.047 m/s in the maximum speed of the meniscus at 1/4 width of the mold. The Fast Fourier Transform (FFT) analysis revealed that the characteristic frequency of the speed fluctuation in the gravity direction of the meniscus near the narrow surface was 1.27 Hz without the consideration of the mold oscillation. Upon the application of the mold oscillation, a new characteristic frequency of 3 Hz, matching the mold oscillation frequency, emerged with twice the intensity of the original 1.27 Hz frequency. Moreover, the mold oscillation had little effect on the characteristic frequency of the speed fluctuation on the meniscus far away from the narrow surface. A user-defined function (UDF) was employed to quantify the number, size, and spatial distribution of entrained slag droplets. The net slag entrainment rate was reduced from 0.0152 to 0.0113 kg/s after the consideration of the mold oscillation, and the number of entrained slag droplets was also decreased. The effect of mold oscillation on the size distribution of entrained slag droplets and the occurrence location of the slag entrainment on the meniscus were not significant.