Research on the mechanism of energy attenuation and compensation during the service-life of oxygen lance nozzles

In the high temperature environment inside the converter, the holes of oxygen lance nozzles will gradually be damaged with the increase in the number of blowing times. Therefore, clarifying the characteristics of nozzle jet and the variation of energy attenuation with the increase in number of blowing times is of great guiding significance for top-blown converter steelmaking. In the present work, the 120 tonnes converter five hole oxygen lance nozzle was taken as the research object, and the jet of nozzles with different damage morphologies were calculated. The jet characteristics and energy attenuation under different blowing heats were comprehensively explored. The results indicated that the wear at the exit of nozzle caused strong fluctuations in the jet, and the energy dissipation during the oscillation stage increased with the increase in the degree of wear. When the blowing heat lied within the range of 241-300, the energy consumption of jet oscillation reached up to 20.31%. A mathematical model was established for the correlation of number of blowing times, oxygen lance heights, and effective impact area. Based on the evaluation index of effective impact area, a compensation scheme for oxygen lance heights and pressure was proposed. The research results provide reference for the rational and efficient use of oxygen lance in industrial smelting.