Study On Fluid Flow Control In Continuous Casting One-strand Slab Tundish

Physical and numerical simulations were carried out to study fluid flow and optimize flow control devices in a continuous casting one-strand slab tundish. The optimum tundish configuration was obtained.Fluid flow was unreasonable with the former tundish configuration. The minimum residence time, peak concentration time and average residence time were short, and the dead zone volume was large in the tundish configuration. The fraction of dead zone volume was36%. It made the effective volume of the tundish smaller, and wse not effective to promote floating and removal of the inclusion from liquid steel.Using of the turbulence inhibitors without top extending lip can improve the flow better than that with top extending lip in the tundish. Increasing the exit area of the turbulence inhibitors can make the fluid flow to larger area. Meanwhile, decreasing the distance from dam to tundish nozzle (S1) and the distance from weir bottom to tundish bottom (H1), and increasing the distance from weir to dam (S2) and the height of the dam (H2) can increase the impact zone volume of the tundish, increase fluid flow path, extend residence time of liquid steel and reduce the dead zone volume in this tundish.Case17was the optimal tundish configuration. Compared with the former tundish configuration, the minimum residence time, peak concentration time and average residence time of fluid flow were increased by30%,117%and33%in the optimal tundish, respectively. The fraction of dead zone volume dropped to14%, being61%lower than the original case. Using of the optimal flow control devices made the fluid flow more reasonable, and can promote floating and removal of inclusions.The results of fluid flow characteristics achieved from numerical simulation agreed well with those obtained from physical modeling. Mathematical simulation results show that the velocity distribution of liquid steel flow was uneven and the dead zone was formed in the area where liquid steel flows slowly in the former scheme tundish. The velocity distribution of liquid steel flow becomed more even and the dead zone volume was decreased obviously, after using of optimal flow control devices in the tundish.For the former scheme tundish, the temperature distribution was uneven in the upper area of tundish nozzle, existing obvious temperature gradient, and the lowest temperature was only1807K in the end of tundish. In the optimal scheme tundish, the low temperature area of liquid steel was decreased obviously at the end wall of tundish, the lowest temperature of liquid steel was1813K, the area of liquid steel temperature more than1819K significantly increased, and the temperature distribution of liquid steel becomed more uniform.When optimizing the tundish configuration, appropriate flow control devices should be adopted and the optimal installation position should be determined according to the inside shape characteristic of the tundish, in order to achieve optimal tundish configuration, obtain the best fluid flow characteristics, and make the fluid flow be favorable to floating and removal of the inclusion in the tundish.