Effect of Asymmetric Bottom Blowing on Melting Behavior of Steel Scrap in a Converter

Abstract

The stirring energy of bottom blowing is one of the most important factors affecting the steel scrap melting in converter. In this paper, a three-dimensional turbulent-multiphase-solidification/melting-solute transport coupling mathematical model is developed to investigate the molten metal flow and scrap melting behaviors in a steelmaking converter under asymmetric bottom blowing conditions. The mathematical model is verified by hot-state experiments. The results show that the dead zone volume fraction and mixing time can be reduced by 3 pct and 30 second by asymmetric bottom blowing, which can provide greater stirring kinetic energy for the molten bath, especially at the bottom of the molten bath, thereby accelerating the melting rate of the steel scrap. In Scheme A1, the time required for the complete melting of the steel scrap is 434 second, which is reduced by 96 second compared with the scheme of symmetrical blowing. Asymmetric bottom blowing can promote the heat exchange between low-temperature molten metal around steel scrap and high-temperature melt in other regions, so that the temperature field around steel scrap is stable at about 1710 K. Meanwhile, it can effectively promote the diffusion of carbon in steel scrap and then promote the rapid melting of scrap.