Characteristics of Supersonic Oxygen Jet in RH Vacuum Refining Furnace

RH is one of the essential secondary refining processes, and the oxygen lance plays a significant part in its multi-functionalization. Therefore, it is necessary to dig deeper into the jet characteristics at low ambient pressure. This study examined the supersonic oxygen jet parameters, such as the jet Mach number, dynamic pressure, turbulence kinetic energy, and half-jet width with computational fluid dynamics, for RH vacuum furnaces operating at ambient pressures ranging from 4000 to 1000 Pa and 101325 Pa. Underexpanded jets were observed at the ambient pressures from 4000 to 1000 Pa, and single strong barrel shocks existed. It was shown that decreasing the back pressure significantly improved the axial and radial Mach number of the jet. However, this improvement was related to a sacrifice of the dynamic pressure. The length of the potential core region and supersonic region increased greatly with decreased ambient pressure. The decrease in ambient pressure also considerably increased the turbulence kinetic energy, indicating a heightened level of energy transfer. However, the correlation between the half-jet width and the ambient pressure was not a simple linear relationship. The half-jet width increased with the ambient pressure decreasing from 4000 Pa to 1000 Pa.