The Mathematical And Physical Modeling Of The Fluid Flow In The Six-strand Tundish

Metallurgy in tundish is an important step in the Continuous Casting Process. It is propitious to average steel temperature and to urge the nonmetal inclusion to float through setting up flow control devices and improving the flow state of melt steel. Mathematical modeling and physical modeling are two effective methods to study the fluid flow. Because the fresh melt steel isn't distributed equably in the sixway tundish of Lian-yuan steel corporation and that arose the lower temperature in the first and sixth strands we use the two ways to research the fluid flow on the condition of the different flow control devices.We choose the K- E model in the course of mathematical computing and plot the flow region in the body-fitted coordinates, then calculate it with the PHOENICS software. In the experiment of physical modeling the paper build the reduced scale of 1:3 model based on similarity theory and 'stimulate-response' technology is applied. The tracer is KC1 solution. We measure the voltage against the tracer concentration. After amplifying and 'transforming them the RTD curves are drawn. Then we calculate the average residence time(ART)-Ta and study the proportions of dead plug, mixed volumes the asymmetrical degree the critical height and the shroud diameter' effect. After dying the fluid flow we analyse its state through observing it and taking pictures. According to their effects, the conclusions are as follows:1. The right flow control devices must be set up. Without them the obvious short-circuit appears in third and fourth exit nozzle. The ART in the modular tundish is just 234.4 seconds.2. Baffle A and B can't or less improve the fluid flow state because their holes aren't reasonable. For example, to baffle A(such as No.l), the ART in the modular tundish equals to 204.0 seconds which is lower 30.4 seconds than that of bare tundish. The maximum difference among all strands equals to 80.8 seconds and the proportion of dead volume reachs 53.7% and the RTD curve has the trend of steep rise and fall. After using baffle B the fluid flow is improved a little. But both the minimum breakthrough time(Tr) and the time to attain peak concentration(Tp) are less than 10 seconds. The proportion of dead volume(Vd%) equals to 30% and the asymmetrical degree(Y) is bigger.3. The apt baffle of C type and D type may greatly improve the fluid flow slate. Take the No.47 and No.50 for example, the ARTs in the modular tundish are 348.1 seconds and 364.3 seconds respectively, more than 5 minutes. The maximum differences are 25.8 seconds and 24.6 seconds respectively, less than 34.6 seconds. The two dead volume ratios are under 20% and the asymmetrical degrees(Y) are smaller. Those achieve the contract demand.4. On the present condition both the bigger pound region volume and the smaller shroud diameter can improve the ART in tundish and in favor of removing inclusion. Comparing D type baffle with C type baffle the former's pound region volume increase 4.4% bring that Ta improve 4.7% and the dead volume ratio decrease 3.5%; In the same conditions the shroud diameter adds up to 36mm based on 22mm bring that Ta decreases 12% and Vd% increases 9.5%.