Three-dimensional analysis of molten steel flow in slab continuous castingmould with rotated ports in submerged entry nozzle

The purpose of this study is to develop a three-dimensional (3D) analysis s ystem capable of analysing the flow field of molten steel in the slab conti nuous casting mould with rotated ports in the submerged entry nozzle. The u ltimate goal is to obtain the optimal design for the entry ports of the sub merged nozzle, which can introduce favourable flow patterns to remove non-m etallic inclusions and avoid entrapment of molten slag and casting powder t o produce steel slab of high cleanliness. In this study, a computational fl uid dynamics technique, Sola-Surf, is employed to conduct the 3D fluid flow analysis. The technique has the capability of treating fluid flow problems with a free surface that slightly vibrates. The slightly vibrating free su rface presents fairly accurately the behaviour of the molten slag-casting p owder layer in the continuous casting mould. The developed simulation syste m is then tested on a slab continuous casting mould to analyse the fluid fl ow behaviour of molten steel under various nozzle designs. The design condi tions include submerged depth of the nozzle, tilted angle of the nozzle por t, and rotated angle of the nozzle port. The results of the simulations sho w that of the various design factors rotation of the nozzle entry ports has the greatest effect on the flow pattern. It can prolong the residence time of the molten steel and stabilise the molten slag-casting powder layer, wh ich is very favourable for obtaining continuous casting slag of high cleanl iness.