Internal Gas Injection into Ladle Shroud and Improvement in Tundish Hydrodynamic Performance

Abstract

In this article, two-phase experimental and numerical investigations are performed to study the effect of inert gas injection to ladle shroud on the hydrodynamic performance of tundish. It is widely known that the flow of molten steel through a shroud, with or without inert gas injection, can influence the flow behavior in the tundish and, consequently, the hydrodynamic performance. However, large throughput rates may promote refractory wear, slag entrainment, and large tundish eye, which are known to seriously impair steel cleanliness, implying a severe need for optimization of the inert gas injection rate into the ladle shroud. In this study, two distinct reduced scale slab-casting tundishes (from different plants) with scale factors of 0.35 and 0.40 fitted with various flow modifiers are considered. Experiments are performed considering gas-to-liquid loading ratios of 10, 20, and 30%. An improved tundish hydrodynamic performance is observed during the experiments, which is validated with numerical modeling results using ANSYS Fluent 2021R1. Although gas injection to the shroud certainly enhances the hydrodynamic performance of tundishes, the effect fades away beyond 20% of the gas-to-liquid loading ratio, regardless of the tundish design, capacity, and different flow modifiers used.