Optimization Simulation Of Flow Field For Five-strand Bloom Tundish

Tundish is an important link in the continuous casting process.The flow field in tundish is crucial to the quality of continuous casting slab.Aiming at the problems of poor consistency and high ration of dead zone volume in the steady-state pouring process of five-strand and T-type bloom tundish in a factory,this paper studies the influence of different flow control devices on the tundish flow field by establishing1:2 physical model and 1:1 mathematical model,design different retaining walls and flow stabilizers,study the flow field of the tundish under different schemes,determine the optimal flow control combination scheme,study the flow field of tundish with less flow under the optimal flow control scheme,study the unsteady flow of tundish under different schemes,and determine the best ladle replacement operation,The results of the study show that:(1)The flow of molten steel under the prototype tundish is poor,there is short-circuit flow at the 2-flow nozzle,the overall consistency is poor,and the dead zone volume ration is high.The area of the low temperature area under the prototype tundish is large,the temperature difference exists in the molten steel at the outlet,the molten steel turbulence in the impact area is serious,and the liquid level fluctuates greatly;(2)In view of a series of problems in the prototype tundish,the flow control device of the tundish is optimized.Under the optimal solution,the response time of each nozzle is more consistent,the flow of molten steel is more uniform,the residence time is prolonged,the floating time of inclusions is increased,the dead volume ration is reduced,and the effective volume of the tundish is increased.The area of the low temperature area is reduced,the heat loss of tundish is reduced,and the temperature of the molten steel at the outlet of each flow outlet is also more uniform.(3)When the tundish is poured with less flow,the volume ratio of the dead zone increases significantly after closing the nozzle When one nozzle is closed,the tundish with 3-flow nozzle has better flow field,and when two nozzles are closed,the tundish with 2-flow nozzle and 4-flow nozzle has better flow field;After closing the 2 and 4flow nozzles,the overall temperature of the molten steel in the tundish decreases,and there is an obvious temperature gradient.The temperature difference of the molten steel at the 1-flow nozzle and 3-flow nozzle increases,and the overall consistency decreases.(4)The tundish replacement process was simulated,and the molten steel in the impact zone was severely exposed under the prototype tundish condition,causing serious secondary oxidation,emulsification of molten steel,and serious slag entrainment.Under the optimal combination of flow control devices,when the insertion depth of ladle shroud is kept at 135 mm,the minimum liquid level for changing the tundish is not lower than 350 mm,and the flow rate of the tundish is not higher than 10 m~3/h,the impact zone of the tundish basically does not occur.The molten steel is exposed,and there is no slag entrainment.