Physical and CFD Modeling of the Effect of Top Layer Properties on the Formation of Open-Eye in Gas-Stirred Ladles With Single and Dual-Plugs

In secondary steelmaking, the optimal size and position of open-eye is important for effective alloying practice. In the current work, the effect of the top layer thickness and density on the formation of open-eye in a gas stirred ladle was investigated. A one-fifth scale water model of 150-ton ladle was established with single and dual plug configurations for the physical modeling measurements. Air, water and three different oils were used to simulate the argon, liquid steel and slag in the water model, respectively. A transient Computational Fluid Dynamics (CFD) model based on Eulerian Volume of Fluid (VOF) approach was developed for numerical modeling of the fluid flow behavior. The physical modeling results show that the relative open-eye area decreases from 46.7 to 5.6% when top layer thickness was increased from 0.75 to 7.5 cm using a gas flow rate of 7.5 NL min(-1). The effect of the number of plugs on the open-eye area for the same range of top layer thickness mentioned above was also studied. The relative open-eye area generated due to the gas injection through the dual plugs decreased from 49.9 to 5.8%. To study the effect of top layer properties, rapeseed oil, castor oil and paraffin oil were employed for studying the effect of density and dynamic viscosity on the open-eye formation. The results revealed that a larger open-eye is formed when the density is increased. Furthermore, it was found out that the density of the upper phase dominates the open-eye formation while dynamic viscosity has only minor effect. The results obtained from numerical simulations and physical modeling were found to be in good agreement.