Physical and Mathematical Modeling of Flow Structures of Liquid Steel in Ladle Stirring Operations

Abstract

Flow structures of liquid steel during stirring operations with argon injection in a ladle are studied using physical and mathematical models. Emphasis is made on the turbulent conditions near the metal-slag interface since this region is important for mass transfer and capture of inclusions by the slag phase. Experiments in a water model are analyzed through two multiphase models; the volume of fluid (VOF), and the Population Balance Model (PBM), which uses the input as the results provided by a Euler-Euler model. It is shown that the VOF model is accurately decomposed into the velocity fields of liquid and gas phases along the plume axis by the PBM model. Turbulent flow near the metal-slag interface is characterized by one and two-point correlations. Statistical correlations decrease under the presence of a top layer (slag). Fields of liquid velocities are well predicted by the VOF, and PBM models. Dimensionless velocity fields of the liquid lower phase, along the dimensionless plume height, can be correlated for a group of experiments or simulations but this procedure cannot be generalized. Increasing the thickness of the top layer breaks down all statistical correlations in the region near the interface. The VOF and PBM models are complementary and became the most suitable tools for ladle metallurgy furnace process-design and analysis.