Physical and numerical simulation for optimization of bottom blowing arrangement of 160-ton ladle

In this study, a novel 1/3-scale water model was designed for a 160-ton ladle based on the similarity principle. The model consists of 24 bottom blow holes and four measuring electrodes positioned at various directions and heights. In order to determine the optimal layout for double-nozzle bottom blowing at a global level, fully combined experiments were conducted at four radial positions of 0.55R, 0.60R, 0.65R and 0.70R and five angles of 90°, 95°, 100°, 110° and 120°. By investigating the effects of different combinations of bottom blowing position and flow rate on mixing time, several preferred schemes for the bottom blowing arrangement were pre-selected in comparison with the industrial prototype. Subsequently, numerical simulations were performed to further optimize the scheme. The Euler-Euler model and the Realizable k-ε turbulence model were employed in the numerical simulation to solve the governing differential equation of the flow field, facilitating acquisition of a three-dimensional unsteady flow field of molten steel during ladle bottom blowing. The distribution characteristics of the flow field and the ratio of dead zones in the pre-selected schemes were analyzed, ultimately leading to the determination of an optimal bottom blowing scheme. The findings demonstrate that, at a blow rate of 4.65 NL/min, the arrangement of bottom blowing positions can be successively ranked as 0.60R-100, 0.55R-110, 0.65R-100 and 0.65R-95 in increasing order of mixing time, including an industrial prototype denoted as 0.65R-95. The mixing time exhibits a gradual decrease with increasing gas flow rate, and for each inlet there exists a critical value of 4.65 NL/min that corresponds to a prototype gas flow rate of 200 NL/min. The numerical simulation results indicate that an optimal arrangement with a reduced mixing time generally exhibits a decreased proportion of dead zone. Considering both the mixing time and proportion of dead zone, the optimal arrangement for bottom blowing is determined as 0.60R-100, where “0.60R” represents the radial position and “100°” denotes the separation angle between dual inlet centers.