Numerical simulation of Argon–Molten steel two-phase flow in an industrial single snorkel refining furnace with bubble expansion, coalescence, and breakup

Abstract

The single snorkel refining furnace (SSRF) is widely used in secondary refining for the miniaturization of special steel. In this study, a computational fluid dynamics (CFD) model, coupled with population balance equations (PBEs), is built to describe the argon–molten steel two-phase flow in an industrial SSRF. In this simulation, bubble expansion due to the sharp variation in hydrostatic pressure and bubble coalescence and breakup are considered for the first time. The numerical results are basically consistent with the experimental observations and calculated values published in the literature for the mixing behavior and local velocity in the physical simulation and the Sauter mean bubble diameter and circulation flow rate in the industrial SSRF. The simulated results indicate that the width of bubble plume increases as the bubbles rise, and larger bubbles are formed in the center of the plume, while smaller bubbles are generated at its outer boundary. Meanwhile, the Sauter mean bubble diameter decreases gradually with rise height until reaching an equilibrium value. In addition, the circulation flow rate of molten steel is relatively independent of the initial bubble diameter. Finally, in the range of explored argon flow rates, the circulation flow rate and the refining efficiency can be enhanced as the argon flow rate is increased.