RH底喷粉精炼过程数值模拟研究

Numerical simulation study on bottom powder injection in RH refining process

RH真空槽底喷粉精炼将脱硫粉剂直接喷入钢液,冶金反应程度高,终点元素含量稳定,能够完成高品质钢的炉外精炼任务。对RH底喷粉过程进行数值模拟研究,探究底喷粉过程的粉剂行为及对钢液流场的影响规律,优化喷嘴布置方案,旨在推动该技术的工业化应用。研究结果表明,180°喷嘴布置方案(即下降管侧喷吹,简称方案2)的钢液环流量比0°喷嘴布置方案(即上升管侧喷吹,简称方案1)增加1.8 t/min(增量比例为1.4%);方案2的钢包最下端钢液粉剂浓度比方案1高0.2~0.9 kg/m^(3)(增量比例为6.7%~81.8%);方案2条件下,钢包内钢液流动死区的粉剂浓度随喷嘴布置高度的降低而降低。结合粉剂收得率,确定方案2喷嘴布置高度为300 mm,此时粉剂收得率较方案1提升2.59%。

Powder injection in RH vacuum chamber can complete the task of secondary refining for high-quality steel.In order to promote the industrial application of this technology,the RH bottom powder injection was numerically simulated to investigate the powder behavior and its impact on the steel flow field,and thus to optimize the nozzle layout.The simulation results indicate that the circulation flow rate of molten steel with nozzle at 180°(i.e.powder injection on the descending snorkel side,abbreviated as scheme 2)is increased by 1.8 t/min(with an increase ratio of 1.4%)compared to that with nozzle at 0°(i.e.powder injection on the ascending snorkel side,abbreviated as scheme 1).The powder concentration in the dead zone of the ladle in scheme 2 is 0.2-0.9 kg/m^(3)higher than that in scheme 1(with an increase ratio of 6.7%-81.8%).Under the condition of scheme 2,the powder concentration in the dead zone of the ladle decreases with the decrease of the nozzle height.Based on the powder yield,the nozzle height of scheme 2 is determined to be 300 mm.The yield of powder in scheme 2 was 2.59%higher than that in scheme 1.