Pressure-Drop and Flowrate Model of Slidegate Metal Delivery Systems (PFSG)

The pressure distribution in the flow delivery system is very important to steel quality, since the minimum pressure in the nozzle can cause air aspiration through cracks, joints, or porous refractory. A new MATLAB-based modeling tool has been developed to predict Pressure-drop Flow-rate relations in a Slide Gate system (PFSG) that enables researchers to investigate these phenomena. This model is validated with three-dimensional finite-difference model calculations and plant measurements and is applied to conduct parametric studies. The slide gate opening at which the minimum pressure occurs depends only on the nozzle diameter and is not affected by tundish height or casting speed. Decreasing lower diameter of the Submerged Entry Nozzle requires an increase in the slide gate opening to maintain casting speed. Furthermore, changing all diameters of the nozzle together has even more effect on the slide gate opening. This effect is beneficial to increase the minimum pressure in the system and lessen air aspiration problems.