Effect of Electromagnetic Swirling Flow in Immersion Nozzle on Round Continuous Casting Process of Steel

Swirling flow in an immersion nozzle generated by a refractory swirling blade has been proved to be effective in commercial test of swirling flow in round continuous casting process of steel in Japan on reduction of meniscus fluctuation,improvement of the temperature of the steel at the meniscus and the equiaxed crystal ratio.However refractory swirling blade is liable to cause clogging in nozzle,which hinders the further application of this process.A new process has been proposed by the authors,that is a rotating electromagnetic stirrer is set up around an immersion nozzle to induce a swirling flow in it by Lorentz force.New types of swirling flow electromagnetic generator(round,U-shape and modified U-shape) are proposed in this paper.In coil current intensity 500A,the effects of the structure of the generator on the flow field in the immersion nozzle and the mold are numerically analyzed.The simulated results show that,Lorentz force can effectively generate swirling flow of the molten steel without contact with the molten steel that flowing in the immersion nozzle.In the case of round generator,a strong swirling flow and thus more reversing flow are induced in the mold compared with no swirling generator case.The distribution of flow field in modified U-shape generator is better than that in U-shape,and gets relative close situation with that in round case.The reliability of the numerical simulation method is verified by the swirling experiment of low melting point alloy.