Jet characteristics of a double-structure oxygen lance and its interaction with the molten pool in BOF steelmaking

An oxygen lance represents a commonly used piece of equipment in converter steelmaking. Its jet characteristics and the interaction of these jets with the molten pool will directly affect the smelting effect and blowing time. This work investigates the oxygen lance of a 260 t converter in a steel plant. Through numerical simulations and physical experiments, the influence of the operating pressure, ambient temperature, top-blowing flow, lance position, and other operating parameters on the jet flow characteristics of the oxygen lance is studied. Furthermore, the oxygen lance interaction with the molten pool is analyzed. The results show that the operating pressure has little effect on the fusion distance of the jet; however, its size determines the impact force of the jet on the molten pool. In addition, the high-temperature environment causes the density of the jet fluid to decrease, the jet attenuation speed to decrease, the jet fusion speed to increase, and the degree of fusion to attenuate. Furthermore, the spray volume of the furnace mouth continues to increase upon increasing the top-blowing flow; by contrast, the spray volume first increases and then decreases as the gun position increases. The maximum spray volume of the furnace mouth occurs at the 35-de gun position; the diameter of the impact pit varies with the gun position. As the top-blowing flow increases, the depth of the impact pit increases with the decrease in the gun position and the increase in the top-blowing flow. The mixing time gradually reduces with the increase in the top-blowing flow and the decrease in the gun position.