Studies by mathematical and physical modelling of fluid flow and inclusion removal phenomena in slab tundish for casting stainless steel using various flow control device designs

A mathematical model, based on the SOLA-SURF scheme and k-epsilon two equation model (where k is the turbulence kinetic energy and e is its dissipation), has been developed to simulate the fluid flow and mass transfer phenomena as well as inclusion removal rate for a single strand stainless steel continuous casting tundish under various designs of flow control device (FCD). A physical model, one-third the scale of the actual slab continuous casting tundish, has also been constructed to observe/measure the fluid flow and mass transfer phenomena directly. The experimental observations/measurements have been used to validate the mathematical model. Satisfactory consistency is noted when the simulated results are compared with the experimental results. The verified mathematical model has been applied to the actual slab continuous casting tundish to evaluate the effects of FCD design on the fluid flow-mass transfer phenomena and inclusion removal rate. It has been found that incorporation of a pouring pad underneath the long nozzle can enhance the opportunity for inclusions to float, and achieves the highest removal rate of inclusions among the four FCD designs evaluated.