Role of Gas Aspiration through Ladle Shroud and Influence on Tundish Hydrodynamic Performances: A Physical and Mathematical Modeling Study

Abstract

Gas aspiration through ladle shroud, during the teeming of a ladle into a tundish, has been investigated via physical and mathematical modeling. To this end, a volume of fluid‐based two‐phase turbulent flow model (in conjunction with the standard k–ε turbulence model) and a full‐scale two‐strand bloom casting tundish have been applied. Both flow and residence time distribution measurements are carried out in the full‐scale tundish system, adopting well‐established measurement techniques. Computational results, supported appropriately with experimentally measured data, indicate that gas aspiration alters flow and turbulence profoundly in the vicinity of the shroud entry zone. Early reversal of jetting flow toward the free surface, due to the buoyancy of the entrained gas, increases the overall intensity of motion in the tundish, creating more mixing flow volumes at the expense of plug flow volume. Most importantly, however, gas aspiration through shroud tends to drastically cut down interactions between the down coming liquid jet metal and the pouring box, making the specific design and shape of a pouring box redundant toward desirable flow modification. Finally, it is shown that strong surface flows and turbulence, generated due to gas aspiration, can be suitably damped by deploying a set of weirs, increasing plug flow volume in tundish.