Abstract: Taking the tundish of Zhejiang Qingshan Iron & Steel Co., Ltd. as the research object, the middle tundish is asymmetric three-flow, producing 200 mm×200 mm billets with a pulling speed of 0.95－1.5 m/min. The water model experiment was conducted in a 3︰5 ratio test, and mathematical simulation assisted observation was performed to observe the changes caused by the parameters of the retaining wall and the diversion hole on the flow field of the molten steel and the equalization of each flow to find the optimal design scheme. The experimental results show that the lag time of the right, middle and left water ports of the original tundish is 40 s, 17 s and 17 s respectively, the mean value is 24.7 s and the standard deviation is 13. The actual average residence time is 636.9 s, 519.4 s and 459.4 s respectively, the mean value is 490.8 s and the standard deviation is 90.28, the dead zone ratio is 23.9 %, and the consistency of the molten steel flow is poor. After the optimized U type retaining wall, the stagnation time of each nozzle is 33.8 s, 31.2 s and 29.7s respectively, the average value increases to 31.6 s, the standard deviation is reduced to 2.11, the actual residence time is 502.1 s, 532.7s and 517.1 s respectively, the average value increases to 517.3 s, the standard deviation is reduced to 15.3, and the flow consistency is greatly improved. The proportion of dead zone dropped to 19.8 %.

Key words: multi-flow asymmetric tundish, flow field, consistency