Numerical Simulation of Fluid Flow and Interfacial Behavior in Three-phase Argon-Stirred Ladles with One Plug and Dual Plugs

A numerical investigation is performed to describe the quasi-steady fluid flow and interfacial behavior in a three-phase argon gas-stirred ladle with off-centered bottom Ar injection through a plug and two plugs placed in 180 degrees and 90 degrees configurations, respectively. The flow of the fluid phase is solved in an Eulerian frame of reference together with the motion of every individually injected Ar bubble, tracked in its own Lagrangian frame. Volume of fluid (VOF) model is used to track any interface between two or more immiscible phases, which include slag/metal, slag/gas and metal/gas. The characteristics of fluid flow in a gas-stirred ladle with one plug or two plugs configuration are described when the slag layer and the top gas are presented. The slag layer deformation and slag open-eye formation at different Ar gas flow rates for three types of plug arrangements are given. The comparison of the mixing time, the deformation of slag layer and the behavior of slag/steel interface between one-plug and two-plug system is made. Several implications for ladle operational issues during a gas-stirred ladle refining cycle are discussed. It is found that the proper selection of Ar gas flow rate and plug arrangements during a ladle refining cycle is required for different refining purposes considering the mixing and metallurgical reaction in a three-phase ladle system.