Effects of Nozzle Layout and Parameters on the Jet Characteristics of a CO2 + O2 Mixed Oxygen Lance

The application of CO2 for converter steelmaking results in several beneficial effects. However, limited studies have investigated the influence of CO2 and O-2 mixed injection on jet flow field and whether jet characteristics can be improved by changing the layout of nozzle holes. This study used FLUENT(R) to simulate the jet distribution of the oxygen lance nozzle of a 120 t converter. First, the model was verified; then, the influences of nozzle center opening area and injection flow rate on the jet characteristics of the main blowing hole were simulated and analyzed. At the same distance, a larger central hole and injection flow rate corresponded to a greater jet axial velocity from the main blowing hole and larger area of impact from the jet onto a molten pool. However, the jet turbulent kinetic energy of the nozzle axis increases with the size of the central hole and injection flow rate; meanwhile, the offset angle of the actual axial velocity of the jet increases, and the coalescence point of each jet advances. The results obtained can serve as reference for the design and optimization of an oxygen lance nozzle for the mixed injection of CO2 + O-2 in converter steelmaking.

Automated summary

This study investigates the influence of CO2 and O-2 mixed injection on the jet distribution of an oxygen lance nozzle in converter steelmaking. Larger central hole and injection flow rate result in higher jet axial velocity and impact area onto a molten pool from the main blowing hole. However, the turbulent kinetic energy of the jet nozzle axis increases with the size of the central hole and injection flow rate, leading to an increase in offset angle of the actual jet velocity and advancement of coalescence point of each jet.