Mathematical And Physical Simulation On Molten Steel Flow In Tundish Of Continuous Casting Process

With the development of steel-making technology, it becomes more and more important to improve the cleanlines and quality of casting steel. Therefore, it is very significant both in theory and practical application to study and analyze the flow field and temperature field of molten steel in tundish.The thesis makes research on the tundish of No.4 slab caster of Bao-steel. Three-dimensional mathematical models are currently being used successfully to simulate liquid steel flow and temperature distribution, the large-scale universal Finite Element analyses software ANSYS CFX is used and many models based on different tundishes are built. By calculating the flow fields in the tundishes with different conditions, analyzing the average residence time in the tundish under transient condition, then the assembled number, the installing order and location of weir and dam are confirmed to have influence on the flow field in tundish, then the structure of tundish is optimized. In the meantime, the water simulation is studied in the paper .And build the scale of 1:3 model based on similarity theory and'stimulate-response'technology is applied. The trace is the saturated salt solution. We measure the conductance against the tracer concentration. The RTD curves are drawn. Then we calculate the average residence time and study the proportions of dead,plug,mixed volume. According to their effects, the conclusions are as follows:(1) Compared with the tundish setting with weir,dam, the tundish has bigger area of dead zone without flow control devices, not be beneficial to inclusions removal.(2) The design of dam is not very appropriate in the case provided by Danieli. So it's not the best choice. a good result can be achieved by adjusting the dam to the top of ladder in the tundish.(3) Under the cases with flow control devices, among the cases near the inlet, the scheme 1 (the distance between weir and inlet is 600mm, the distance between dam and weir is 400mm, the high between the bottom and weir is 300mm, the high of dam is 400mm)is better. Among the cases far from the inlet, the scheme 10(the distance between weir and inlet is 1500mm, the distance between dam and weir is 600mm, the high between the bottom and weir is 250mm, the high of dam is 430mm)is better. (4) For the practice of Bao-steel, Optimized case is test3. Paramater as following: The turbulence inhabiting pouring pad Bao-steel now used is selected, the distance between dam and weir is 450mm, the high between the bottom and weir is 300mm, the distance between weir and inlet is 1750mm, the high of dam is 500mm.