Numerical simulation study on the effect of bottom blowing mode on flow and mixing phenomena in the ladle molten pool

Abstract

Based on the process parameters of bottom argon blowing in the steel ladles of a certain steel plant, a 1:1 full-scale numerical model was established. The evolution laws of the flow field structure, homogenisation characteristics, and fluctuation behaviours of the steel and slag interfaces under different blowing rates were analysed in detail. The mechanism of the effects of different blowing parameters on the flow characteristics of the molten material and metallurgical efficiency was clarified. Research indicates that a double plug, different flow bottom blowing model can effectively reconfigure the melt pool flow field structure by differentially regulating the gas supply parameters of the porous plug. The upward flow created by the high bottom blowing rate (800 L/min) has stronger penetration, driving the molten steel to form a high-level diffusion circulation; the low bottom blowing rate (400 L/min) forms a diffuse flow field near the bottom. Together, they create a three-dimensional circulation system that covers the entire area. Numerical simulations and water model experiments confirm that the 800_400 L/min mode exhibits optimal dynamic characteristics: the mixing time calculated numerically is controlled within 47 seconds, a 5% reduction compared to the original mode. Additionally, the overall fluctuation of slag in the 800_400 L/min mode is controlled within 0.25 m, a 17% reduction compared to the original mode. Notably, this mode achieves a 25% reduction in argon gas consumption while maintaining metallurgical effectiveness, demonstrating significant engineering and economic benefits, and also providing a theoretical basis for optimising the refining process.