Prevent of clogging via a mathematical model of heat transfer in submerged entry nozzle

Abstract

Clogging of the steel in the submerged entry nozzle (SEN) is mainly due to the agglomeration and/or interaction of the steel with the SEN refractory material. However, the continuous casting steel also leads to clogging - the freezing of the steel in the SEN at the beginning of the casting. The freezing of the steel in the SEN results mainly in the change in the geometry, the low casting temperature of steel, the insufficient preheating of the SEN and the low initial casting speed. To eliminate the problems of steel freezing at the beginning of continuous casting, the authors solved them using a mathematical model of heat transfer in the SEN. Using the mathematical model, it is possible to simulate the layout of temperatures in the SEN and the temperature of the steel at the interface of steel - the inner surface of the SEN. To determine the temperature layout in the SEN after installation on the tundish, a method of measuring the decreased average temperatures of the SEN by free convection after heating was used. Based on the analysis of the current state using simulations in a mathematical model, it is possible to define conditions for preventing the freezing of steel in the SEN when the wall thickness or isolation thickness is changing.