Numerical Simulation of Influence of Argon Flowrate on Tundish Nozzle Clogging during Continuous Casting

Influence of argon flowrate and slide gate opening ratio on deposition rate was researched by the method of numerical simulation. Flowrate of argon had influence markedly upon pressure in the nozzle, and the pressure dropped suddenly after molten steel flowing through the slide gate. To keep positive pressure at slide gate for avoiding inspiration of air, minimum flowrate of argon was increased from about 10 L∙min−1 to 25~30 L∙min−1 as slide gate opening ratio decreasing from 66.45%to 42.82% when casting speed was 1.2 m∙min −1 . Influence of argon flowrate on the deposition rate of alumina was related to the slide gate opening ratio. When the slide gate opening ratio was big, such as 66.45%, the deposition rate of alumina occurred maximum and minimum values as the argon flowrate increased step by step. When the opening ratio was small, such as 50.46% and 42.82%, the deposition rate of alumina was decreased all along as the argon flowrate increased, and the effect of argon flowrate on decreasing alumina deposition rate was not obvious when the argon flowrate was more than 15~20 L∙min −1 . Considering the influence of flowrate upon to static pressure in nozzle and deposition rate, the appropriate argon flowrate was 10 L∙min−1 as big opening ratio of slide gate (>60%). Due to the disadvantage of high flowrate, the appropriate argon flowrate was 15~20 L∙min −1 as small opening ratio (<60%).