Flow Characterization and Inclusions Removal in a Slab Tundish Equipped with Bottom Argon Gas Feeding

Resumo

The fluid dynamics of a straight tundish was studied when Ar-gas was fed through the bottom, using mathematical simulation. Flow rates of 15 and 40 liters/min of argon in three locations into the tundish – near input steel, center, and near output steel – were analyzed. A stochastic model was employed for determining statistically the particle amount (emulating alumina particles) in the inclusions removal. From these calculations and those of the Residence Time Distribution (RTD) curves, we found a direct relationship to improve steel quality. Specifically, removal of the smaller nonmetallic inclusions was significantly enhanced for cases with the lowest dead volume fraction; they correspond to those of the highest averaged residence time. Therefore, it was found that it is even possible to reduce argon consumption and still obtain good results of steel cleanness.