Ideal Stopper Rod Lifts for Various Casting Conditions

Abstract

Mathematical formulations to determine the flow controlling gap between a stopper rod and submerged entry nozzle are presented along with derivations. Expressions are also presented for the ideal stopper rod lift in terms of casting conditions and height of liquid metal in the tundish in order to maintain a constant mold level. Calculations using these formulations for a few example configurations are presented. These formulations could be used to determine the potential for flow rate control with a particular stopper rod as well as to make design improvements to increase this control. A possibility of using these calculations to estimate the extent of buildup on the stopper rod or orifice regions is also introduced.