Optimization design of jet characteristics for staggered oxygen lances in small and medium-sized converters

In the modern steel production process, the behavior of oxygen jets exerts a significant influence on the converter smelting effect. Taking a 120 t converter in a steel plant as the research object, numerical simulation methods are employed to investigate the effects of nozzle arrangement, inclination angle and flow rate ratio of staggered oxygen lances on jet characteristics. The results show that compared with the nozzle arrangement mode with large nozzles and small inclination angles, the arrangement with large nozzles and large inclination angles can make the radial dynamic pressure distribution of jets more uniform, enhance jet independence, and thus obtain a larger effective impact area. Increasing the inclination angle accelerates the attenuation of jet velocity, increases the jet merging distance, and improves the uniformity of radial dynamic pressure distribution, with the effective impact area reaching the maximum value when the inclination angle is 16°. In addition, with the increase of flow rate ratio, the velocity of large-nozzle jets increases while the merging distance decreases, leading to an expanded difference in radial dynamic pressure peaks between large and small nozzles. The effective impact area increases with the rise of flow rate ratio, so the optimal flow rate ratio is determined as 65%/35%.