Physical Modeling of Inclusion Approach to the Steel–Slag Interface with Focus on Hydrodynamic Interactions

Abstract A physical model is developed in order to understand the behavior of non‐metallic inclusions near the steel–slag interface during the vacuum ladle treatment of liquid steel. A flat liquid/liquid interface is created using glycerol as the heavy phase and silicone oil as the light phase. Spherical polymer particles are introduced into the glycerol and filmed while they rise up towards the interface. The density and the diameter of the particles as well as the viscosity of the silicone oil are varied. The particle velocity is measured as a function of the distance to the interface and the hydrodynamic correction factor of the Stokes steady drag is deduced. Results are compared with the available theoretical models, in particular, for non‐deformable no‐slip and free‐slip interfaces. Then, the dependence of the hydrodynamic correction factor on the density difference ratio, the capillary number, and the viscosity ratio is examined.