The Study Of Numerical And Physical Simulation In The Tundish And Mold For Billet Continuous Casting

In this paper,physical simulation experiment and numerical simulation study are carried out for the optimization needs of a new billet continuous casting machine in a steel plant of six-strand tundish and five-strand tundish,and mould SEN(Submerged Entry Nozzle)for continuous casting.For the optimization of tundish,by increasing the distance between ladle shroud and SEN,the fluid flows smoothly in a large space and stable eddy current forward flow is formed in the injection flow area,which is conducive to increasing the residence time of molten steel in the tundish and enhancing the floating of inclusion.The simulated flow of water in tundish tests the change of flow field when the distance between ladle shroud and SEN is 2000 mm,1600mm and 1300 mm,respectively.For six-strand tundish,when the distance between ladle shroud and SEN is 2000 mm,the volume fraction of dead zone does not change much,and the residence time of molten steel increases.At the same time,the inclusion removal rate increases with the increase of the distance between ladle shroud and SEN.For the five-strand tundish,the flow field changes significantly by changing the distance between ladle shroud and SEN.Under the condition of turbulence controller,increasing the distance between ladle shroud and SEN can significantly reduce the dead zone volume and improve the inclusion removal rate.In the process of tundish RTD test,for the tundish of six-strand and five-strand,the first flow to flow out of the tundish is the intermediate flow,and the flow pace of the intermediate two flows is relatively consistent,and the side flow flows last to flow out.The intermediate flow of the five-strand tundish is the slowest to respond to the "stimulus" because it is on the back of the porous retaining wall.Numerical simulation was carried out for the straight and four-hole nozzle of the mold.The straight nozzle has a large speed difference in the horizontal direction of the nozzle due to the same direction of outflow and the casting direction,and the four-hole nozzle has an angle between the direction of outflow and the casting direction,forming up and down vortices near the hole of the nozzle.As the depth of nozzle insertion increases,it has little effect on the straight nozzle.For the four-hole nozzle,the position of eddy current changes significantly,which will affect the mold level fluctuation and heat transfer.Through the above numerical simulation study and combined with the design of continuous casting machine,the design scheme of flow control device for six-strand tundish and five-strand tundish,the type of mold SEN and the recommended value of insertion depth are given.