No abstract

An electromagnetic field simulation along with a fluid flow analysis model were developed, to study the effect of the submerged entry nozzle's (SEN) angle of rotation, together with a rotational electromagnetic field, on the turbulent liquid steel flow within a curved, square mould of a billet continuous caster. The Realisable-k-ɛ turbulence model and the volume of fluid multiphase model were implemented, so as to simulate the effect of turbulent fluid flow on the shape of the top liquid steel meniscus. Similarly, the magnetic induction method was employed for simulating the effects of rotating magnetic fields on the flow patterns developed within the mould region. The predicted magnetic field and fluid flows were validated against previous experimental work. Predicted results demonstrated that fluid flows and the shape of the liquid steel meniscus could be significantly modified by changing the orientation of the SEN's ports in the presence of a lowfrequency rotating magnetic field.

The control of fluid flows within the mold region of continuous casters is a key factor in improving the quality of cast products. The performance of two different flow modifiers in the curved mold region of a typical square billet caster are compared. The flow modifiers investigated in this work are a 5-ported Submerged Entry Nozzle (SEN) and a Brake-Electromagnetic Stirring (Brake-EMS) unit, interacting with a Main-EMS. Two different commercial software programs, ANSYS Fluent and COMSOL, are used to develop a numerical Magneto-Hydro-Dynamic (MHD) model of this system, in order to study the efficiency of the selected flow modifiers. According to the simulated results, the dual-EMS unit (Brake-EMS together with Main-EMS), intensifies the swirling flows in the mid-region of the mold, but cannot decrease the intensive vertical upward flows that are being generated toward the meniscus corners. The proposed radial angulation of the SEN's exit ports, working in tandem with the Main-EMS, not only develops swirling flows at the midsection of the mold, but also transforms the vertical upward flows to a horizontally rotating flow near to the upper surface of the caster. This slight modification calmed flows at the liquid steel meniscus, thereby reducing mold powder entrainment (MPE).