Physical modeling of slag carryover in the last stage of ladle teeming during continuous casting with dynamic change of slide gate opening

To investigate slag carryover in the last stage of ladle teeming during continuous casting, a water model system was established. The nozzle flow rate of model ladle was controlled by slide gate, which was automatically governed by a control module. The prototype teeming process can be accurately modelled through the system. However, under the condition that the slide gate is fully opened, the teeming process in water model has a great deviation with the actual. The vortex critical height in the mode of dynamic changing of slide gate is obviously less than that under the condition of 100% opening. Furthermore, under the dynamic changing mode, effects of operating parameters on vortex formation and slag carryover have been investigated. The vortex critical height decreases as the residence time before teeming increases. The effect of initial water level on critical height of vortex is little. As the flow rate increases, the critical height of vortex increases significantly. The variation of vortex diameter experiences developing stage and matured stage. When oil is added into model ladle, an important change is that the critical height of vortex decreases. By contrast, the vortex diameter obviously increases. The vortex critical height decreases while oil is added into ladle, but it increases as the oil layer thickness increases.