Coupled CFD-DEM with Flow and Heat Transfer to Investigate the Melting and Motion of Alloy

Abstract

The melting and motion of ferroalloys play a crucial role in the mass transfer and homogenization of molten steel in ladles. Heat transfer, melting, and solidification behavior of an alloy affect its size, thereby altering its motion within the gas-stirring ladle. This study established a heat transfer and solidification-melting model for alloy particles in high-temperature metal liquids. The computational fluid dynamics (CFD) method was used to simulate the fluid within the ladle, and the discrete element method (DEM) was employed for the alloy particles. This coupling approach elucidates the motion trajectories of different types of alloys in molten steel under flow and heat exchange, particle heating, melting, and shrinkage conditions. Furthermore, the effects of alloy size, initial alloy temperature, molten steel flow rate, and molten steel temperature on the melting behavior of different types of alloys were investigated. The results showed that the melting time exponentially increased with increasing alloy size or decreasing molten steel flow rate. Moreover, the alloy melting time decreased with increasing initial alloy temperature or molten steel temperature. The impact of these factors on the melting of FeCr, FeMn, FeSi, and Al alloys was also evaluated. Furthermore, FeSi and Al alloys added at different positions in the ladle with symmetric dual gas bottom blowing had a residence time of only 1 second in the molten steel and did not completely melt. These findings indicate that FeSi, Al, and FeCr alloys should be added at the 0.4R position in the symmetrical plane. Furthermore, the − 0.4R or − 0.2R positions are more favorable for the melting of FeMn.