The swirling effect in an immersion nozzle on the flow in a continuous casting mold

A numerical analysis and water model study of the mold region of a continuous casting apparatus was performed with a novel injection concept using swirling flow in the pouring tube, to control the heat and mass transfer in the continuous casting mold. As a result, the following results were found: 1) By changing swirl strength, it is easy to control the flow pattern as well as the direction of the flow. 2) Uniform velocity distribution can be obtained within a very short distance from the outlet of the nozzle. 3) Heat and mass transfer near the meniscus can be remarkably activated compared with a conventional straight type immersion nozzle without swirl. 4) Swirl helps the superheat in the melt dissipate. 5) Penetration depth of nozzle outlet flow is decreased remarkably by the application of swirling. 6) For the case without swirl, the peak of the flow moves near the mold-wall with flowing down from the outlet of the nozzle due to the Coanda-effect. On the other hand, peak of the flow moves near the mold axis with flowing down from the nozzle-outlet within considerable short distance, namely axi-symmetric velocity distribution can be obtained within very short distance from the nozzle-outlet. Those findings mentioned above are very useful to control the flow pattern in the billet and bloom continuous casters.