CFD simulation of multiphase melt flows in steelmaking converters

The three-dimensional, transient, non-isothermal flow of melt, slag and oxygen/argon is simulated for a 335 t combined blowing converter with six-hole top lance and 14 bottom tuyeres. The calculation is based on the Reynolds averaged Navier-Stokes (RANS) equations and the Standard k-epsilon model. The time-dependent formation of the melt cavities is modeled by the Volume of Fluid (VoF) approach. To simulate the stirring gas plumes, individual argon bubbles are released from each bottom tuyere. The bubbles are treated as dispersed phase and modeled by the Discrete Phase Model (DPM). The basic flow phenomena such as the penetration of the supersonic oxygen jets, the motion of the liquid interfaces, the behavior of the gas plumes and their interaction with the bulk flow as well as the heat transport in the refractory lining are predicted reasonably well. However, the blowing process can only be simulated for a limited process period due to computing-time reasons. Thus, the mixing time, which gives detailed information on the homogenization process, is calculated for pure bottom-blowing. The CFD model provides an efficient tool to describe and further improve the combined blowing process