| In the process of multi-strand continuous casting,as a transition container for casting ladle and crystallizers,the tundish plays roles in storing aluminum liquid,evenly distributing aluminum liquid into each crystallizer,purifying aluminum liquid and so on.A reasonable flow control device can effectively optimize the flow of molten aluminum in tundish,uniform flow distribution and temperature field,promote the removal of impurities which can improve the quality of casting billet and increase the success rate of casting.Therefore,studying the influence of different flow control devices on the flow distribution and temperature field of molten aluminum in tundish can provide research ideas and theoretical guidance for the industrialized application of multi-strand continuous casting technology for aluminum.This paper takes the five-strand horizontal continuous casting tundish of an aluminum plant as the research object and studys the influence of different flow control schemes on fluid flow by physical simulation and numerical simulation.Based on the optimal flow control scheme,the influence of deflector holes’ height and angle on flow behavior of aluminum liquid in the tundish was investigated by orthogonal calculation.A three-dimensional flow and heat coupled model was established which can describe the fluid flow and heat transmission in a five-strand continuous casting tundish.The coupling calculation of the flow behavior and heat transmission of aluminum liquid in three kinds of flow control schemes was performed by the software of ANSYS Fluent.Three kinds of tundish models were made according to the ratio of 1:4.Water was used as fluid medium,and the velocity and temperature in specific locations were measured.Comparing measured results with calculated results,the error is within a reasonable range which verifies the accuracy of the calculation model.Numerical simulation results show that scheme three effectively improves the flow behavior of molten aluminum in tundish,and the velocity and temperature distribution is uniform.After flowing out from deflector holes in scheme three,aluminum liquid flows upwards till above the first outlet,and then flows to each outlet.The dead volume is small and the short-circuit flow is eliminated.Besides,aluminum liquid residence time is long which is beneficial to elimination of impurities.The temperature difference of molten aluminum in the whole tundish falls from 15 K in scheme one to 9K in scheme three with a drop of 40.0%.The maximum temperature difference of outlets is reduced from 7K in scheme one to 2K in scheme three which drops 71.4%.Based on scheme three,further study was conducted on the structural parameters of its flow control device,and the effects of deflector holes’ height and angle on the flow behavior and heat transfer of molten aluminum in tundish were calculated.The calculation results show that the height and angle of the deflector holes have a great influence on fluid flow.The fluid flow in tundish with flow control devices of 50mm/30°,100mm/20°,150mm/10°are reasonable.The standard deviations of velocity on each outlet are 0.12mm/s,0.30mm/s and 0.29mm/s,respectively.The velocity distribution is even,the dead volume is small,the liquid residence time is long,the liquid level is stable,and the billets’ quality and the process of casting can be guaranteed.The height and angle of deflector holes have little effect on temperature distribution in tundish.The temperature difference of the whole tundish is between 8.2K and 9.9K,and the temperature difference on each outlet is between 2.1K and 3.3K.In summary,the flow control devices of 50mm/30°,100mm/20°,150mm/10° meets production requirements. |
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