Optimization of the tundish flow field based on F-curve

The water model with a similarity ratio of 1∶2 was established for a three-strand beam blank tundish. The molten steel flowing character was researched in different flow control devices by using the F-curve, and the flow field of the tundish was optimized. The volume fractions of dead region, plug flow and well-mixed flow are calculated. The standard deviation of the stagnation time of 1, 2 and 3 flow and the maximum value of standard deviation function of F-curve were used to evaluate the dispersion of each flow. Three cases were considered during the experiments, i.e, prototype flow control device, turbulence inhibitor without dams combination, turbulence inhibitor and dams combination. The results show that short circuit flow exists in the middle nozzle of the prototype tundish, and poor consistency between nozzles, which may lead to the uneven temperature and cleanness of the three-strand beam blanks, leading to different quality of different beam blanks in one heat. Using the turbulence inhibitor without dams combination, the short circuit flow appears in the middle of tundish with the angle of diversion holes being 60°. When the angle is 86°, there is no short circuit flow, and the consistency between strands becomes better. When the angle is 110°, the short circuit flow appears in the two sides of the tundish nozzle with the best consistency between strands. There is no correlation between the consistency of the tundish strands and the dead volume fraction. When the consistency of the tundish strands is good, the dead volume fraction may not be small. After optimization, the angle of the diversion hole of the tundish turbulence inhibitor is 110°, the dam is 2400 mm away from the tundish center. There is no short-circuit flow, the consistency of 1# and 2# nozzles is the best, the dead volume fraction is reduced to 9.67% from 17.89%, and the reduction rate is 11.25%. The maximum standard deviation of the F-curve is reduced to 0.016 from 0.3.