To enhance the efficiency of the RH vacuum refining system a physical model of a 150 t RH vacuum refining system incorporating a vacuum chamber, snorkels, and ladle was established. The Euler-Euler two-fluid method was adopted for numerical simulations to systematically investigate the effects of different downcomer-to-riser diameter ratios on the circulation characteristics and refining performance of the RH device. The flow velocity at each position, flow field of the main cross-section, agitation effect on the molten steel at the ladle bottom, circulation flow rate, and mixing time under different diameter ratios(1-1.4) were analyzed for various diameter ratios. The results show that increasing the downcomer diameter significantly enhances the circulation flow rate(390 kg/s-492 kg/s), while the mixing time decreases (286 s–269 s). The flow field in the ladle tends to concentrate in the region between the two snorkels, the flow field in the vacuum chamber improves, and the proportion of the active region of molten steel at the ladle bottom decreases (from 39% to 19%). Considering all factors, the optimal diameter ratio of the downcomer to the riser is 1.2, which can balance the improvement of the circulation flow rate and maintain excellent molten steel stirring capability.
Kuwabara T , Umezawa K , Mori K J , et al . Investigation of decarburization behavior in RH-reactor and its operation improvement [J]. Transactions of the Iron and Steel Institute of Japan , 1988 , 28 ( 4 ): 305 - 314 .
Ling H , Zhang L , Liu C . Effect of snorkel shape on the fluid flow during RH degassing process: mathematical modelling [J]. Ironmaking & Steelmaking , 2018 , 45 ( 2 ): 145 - 156 .
Li B K , Tsukihashi F . Modeling of circulating flow in RH degassing vessel water model designed for two- and multi-legs operations [J]. ISIJ International , 2000 , 40 ( 12 ): 1203 - 1209 .
Chen G J , He S P , Li Y G , et al . Investigation of gas and liquid multiphase flow in the rheinsahl-heraeus (RH) reactor by using the Euler-Euler approach [J]. JOM , 2016 , 68 ( 8 ): 2138 - 2148 .
Geng D Q , Zheng J X , Wang K , et al . Simulation on decarburization and inclusion removal process in the ruhrstahl-heraeus (RH) process with ladle bottom blowing [J]. Metallurgical and Materials Transactions B , 2015 , 46 ( 3 ): 1484 - 1493 .