Optimization Of Structure In 40t Eccentric Tundish

As an important equipment in the continuous casting production process,the tundish is the key link to ensure the quality of the steel from smelting and refining to solidification into billet.The metallurgical function of the tundish depends on the reasonable flow of molten steel in the tundish.Therefore,a reasonable tundish structure and molten steel flow can give full play to the metallurgical properties of the tundish,ensure the continuous casting process is stable and smooth,and improve the quality of the billet.Aiming at the problems that the covering agent is difficult to flow into the tundish and the molten steel flow is not good in the continuous casting production process of Basteel,this paper takes the 40 t tundish of Basteel as the research object.Based on the design of the upper and side openings of the turbulence inhibitor and the structural transformation of different weir and dam combinations,the influence of the structure of the turbulence inhibitor and the weir on the tundish flow field was analyzed,and the optimal flow control scheme was determined.Based on the similarity ratio of 1:3,a 40 t tundish physical model was established,and the RTD curve and flow field distribution of the prototype tundish under different pulling speeds were studied.It was found that the proportion of dead zone in the prototype tundish flow field was as high as 53%,and the proportion of fully mixed flow was 41%.When the pulling speed increased from 1.9 m/min to 2.5 m/min,the proportion of dead zone and total mixed flow in the tundish gradually decreased,and the plug flow remained basically unchanged.With the increase of the pulling speed,the molten steel is more fully mixed,which is conducive to the floating of inclusions and improving the quality of cast billets.On the basis of mastering the characteristics of the prototype flow field of the tundish,the flow field characteristics of the tundish under different structures of the current turbulence inhibitor are studied based on the structural design of the openings above and on the side of the injection hole of the current stabilizer.It is found that when the top of the flow turbulence inhibitor is opened,the cover in the flow turbulence inhibitor can flow into the tundish to a large extent,but the proportion of the dead zone increases significantly,which is not conducive to the mixing of molten steel,the uniform temperature and the removal of inclusions.The effect of pulling speed,flow turbulence inhibitor and weir structure on the flow field of the tundish was studied by orthogonal experiments,and it was found that the effect of the tundish flow field was in the order of flow turbulence inhibitor structure,pulling speed,weir structure.When the pulling speed of the tundish is increased from 2.1 m/min to 2.3 m/min,the inner diameter of the injection hole is reduced from the prototype 160 mm to 90 mm,the dead zone ratio can be reduced from 53% to 25%,and the optimization effect is remarkable.On the basis of physical simulation analysis,Fluent numerical simulation software is used to further analyze the tundish prototype and optimal combination scheme.The results show that the optimized combination is gentler than the prototype RTD curve,the short-circuit flow phenomenon in the tundish is improved,the molten steel is mixed quickly,and the impact area at the end of the flow beam is increased,which is more conducive to removing inclusions in the steel and cleaning the molten steel.The response sequence of the numerical simulation nozzle is nozzle 3 → nozzle 4 → nozzle 2 → nozzle1 → nozzle 5,which is consistent with the physical simulation results.The study of this paper shows that the opening cover above the flow turbulence inhibitor can flow into the tundish significantly,but its dead zone ratio will increase significantly.At the same time,the optimal experimental scheme of the tundish was determined through orthogonal experiments.It is suggested that enterprises can improve the tundish flow field and improve product quality by increasing the pulling speed and reducing the inner diameter of the injection hole from the prototype’s 160 mm to 90 mm.