Numerical study on steel flow dynamic behaviour in a round mould under the effect of a swirling flow brick design in tundish

Abstract

Swirling flow submerged entry nozzle technology is one of the important methods to optimise the continuous casting of steel. In this study, a novel swirling flow brick design in tundish was proposed to achieve a swirling flow submerged entry nozzle. Numerical simulations were carried out to investigate steel flow dynamic behaviour in a round mould under the effect of new designs. The results showed that a rotational steel flow was generated inside the submerged entry nozzle by using both two-inlet and three-inlet brick designs. Due to the rotational flow momentum, molten steel from the submerged entry nozzle outlet moved towards the mould wall. Such a flow pattern eliminated the impinging flow in mould, which was generally formed in conventional single-port submerged entry nozzle casting. When using swirling flow brick designs, the whole flow field in the submerged entry nozzle and mould exhibited a dynamic change. As the side-inlet number of bricks decreased from three-inlet to two-inlet, the velocity fluctuation range was reduced from ± 63.3% to ± 8.9%. Moreover, the swirling flow intensity in the submerged entry nozzle was decreased by about 40%. In addition, a high-pressure region above atmospheric pressure was obtained near the submerged entry nozzle wall by using new designs, which is helpful to prevent air from being sucked into the submerged entry nozzle.