Influence of Carrier Gas of Converter Oxygen Lance on Smooth Distribution of O2−CO2−CaO Mixed Jet

Abstract

Converter steelmaking is the primary steelmaking method because of its fast production rhythm and ability to handle molten iron. Despite its benefits, there are some limitations with this method that cannot be ignored. These limitations include excessive loss of iron by evaporation caused by a high-temperature fire spot zone and uneven melting of lump lime, which leads to an increase in steel consumption and a decrease in steelmaking efficiency. In view of these shortcomings, this study tested the approach of mixing a top-blown O2 lance with CO2. The mixture gas (80%O2 + 20%CO2) was used as a carrier gas to blow CaO powder from the top-blown oxygen lance into a molten bath. Based on the standard κ−e turbulence model and the discrete particle model, the effects of flow rates of carrier gas on the distribution of gas and CaO powder jets were analyzed by numerical simulation. The simulation results show that the velocity of Cao powder increases with the increase in gas flow rate. The distribution area of Cao powder in radial section is more concentrated, and the deviation distance between Cao powder distribution and pore axis is shorter. At the same time, because of the inertia force of Cao powder, the attenuation speed of carrier gas jet in subsonic region slows down. The interaction between mixed carrier gas and powder is beneficial for the mixture gas and powder to participate in metallurgical reaction.