Purifying Technology in the Tundish Metallurgy-Discussion about the Model of Residual Time Distribution for Tundish
tundish metallurgy is critical in continuous casting process, and it has much to do with the clean steel technology. And the most effective and convenient way to evaluate the tundish designing or tundish metallurgy is to calculate different regions volume fraction in the tundish. Till now this can only be solved through some calculation models based on the analysis of residual time distribution (RTD) curve. In this paper, the short-coming of widely used modified mixed model and combined model are pointed out and explained. (1) it doesnt cover and cant calculate the volume fraction of bypass flow region, but bypass flow is always critical for optimizing tundish delsigning and tundish metallurgy; (2) and it is also not reasonable to define plug flows volume fraction equals to (1/2)(θmin＋θmax)orθmin,because for two different kinds of tundish even when θmin and θmax has the same value respectively, the plug flow volume fraction is different according to calculation result of vananceσ2; (3) it is not reasonable to define the dead regions volume fraction equals to1-θav, and in some case, minus value of the dead regions volume fraction is obtained if this equation is adopted Then in this paper, it suggests that it is not reliable to use these models to guide the tundish designing and tundish metallurgy process. At last a new model is attempted to propose. In the new model, the dead region is specifically defined,and it can be adjustable to define according the actual demand; and it can distinguish different flow patterns sensitively; whats more, when there exists combination of four different regions in the tundish, the volume fraction of each region can be solved at the same time, which can not be solved by the models proposed before; and the new model is able to calculate the bypass flow regions volume fraction, and almost no other model can do it so far. Especially, it is suitable for both of single-strand and multi-strands situations.
tundish residual time distribution (RTD) dead region backmix region mathematical simulation
PAN Hongwei CHENG Shusen
School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China
国际会议
2008 International Symposium on Clean Steel(2008年洁净钢生产技术学术研讨会)
鞍山
英文
141-150
2008-09-17（万方平台首次上网日期，不代表论文的发表时间）