| The process control in continuous casting production has a great influence on the quality of continuous casting slab.Tundish,as the intermediate vessel in the process of continuous casting production,plays a key role in the quality of continuous casting slab.This is because the internal structure of tundish influences whether the molten steel transported from the large ladle can obtain good flowability and be reasonably distributed to the continuous caster,At the same time,it is also very important to control the temperature of molten steel in tundish.With the development of continuous casting technology,multi-strand continuous casting technology has been widely used because of its high efficiency and stability.It also promotes the development of multi-strand tundish.In this paper,a Five-strand four-channel induction heating tundish in a factory is used as a model,and the fluent simulation software is used to optimize the simulation of different turbulent flow,different position of retaining wall and different number of holes in the retaining wall.The removal effect of inclusions under heating condition is analyzed by numerical simulation and verified by 1:4 physical model.Through the simulation and analysis of temperature field and RTD curve of tundish flow field,the results show that:The internal structure of the original tundish is unreasonable.There are different degrees of short-circuit flow in the molten steel flowing out of each nozzle of the tundish,and the consistency of multi-flow is poor.According to this model,when the retaining wall is installed at 850 mm away from the nozzle,the liquid steel in the tundish can obtain better flow performance.Compared with the original tundish,the total residence time of the tundish after the retaining wall is 987s,extending 205s;the volume of the whole mixing zone is 54.78%,increasing 19.18%;the volume of the dead zone is 14.32%,reducing 17.8%.Tundish consistency increased from 5.56×10-6 to2.66×10-6.The overall temperature drop of tundish was reduced from 47.5K to35.8K38.4K,and the temperature difference of each flow was reduced from 2.16K to0.79K,with a decrease of more than 63.4%.Based on the optimized tundish structure,the simulation of tundish heating state is carried out.The results show that:after the tundish is heated,the flow pattern distribution is more uniform.Compared with normal temperature,the highest temperature of molten steel flowing out of tundish channel after heating is 20K,and the volume of dead zone decreases from 14.32%to 12.33%.The average residence time was extended from 987s to 1010s and 23s.The consistency of each flow in tundish has changed from 2.66×10-66 to 2.39×10-6,and the consistency of each flow has been improved.After the tundish channel is loaded with heat source,the removal of inclusions in tundish molten steel can be enhanced to a certain extent.Especially for the impurities removed by Stoke floatation,the removal rate of inclusions increases by5.1%on average. |
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