A Numerical Study on Particle-Induced Erosion to Laval Nozzle in Powder-Oxygen Injection Using BOF Lance

Oxygen-powder injection from a BOF lance has received much attention in attempts to improve refining efficiency, but knowledge of particle-induced erosion to the lance nozzle, as one of the foreseeable concerns in such a process, is still limited. Thus, numerical studies on gas-particle flow through a Laval nozzle were performed to clarify what the nozzle erosion distribution is and how it is influenced by particle motion. The results show that the most serious erosion occurs in the nozzle convergent section, where nozzle erosion can be further intensified by increasing the powder feeding rate or particle size. The powder blowing parameters have a significant influence on the erosion rate and distribution. Increasing the powder feeding rate or decreasing the particle size worsens erosion downstream of the nozzle divergent section. Therefore, in order to reduce erosion, the powder feeding rate and particle size should be smaller than 2.0 kg/s and larger than 10 mu m, respectively.

Automated summary

Oxygen-powder injection from a BOF lance can cause erosion to the lance nozzle, with the most serious erosion occurring in the nozzle convergent section. The erosion rate and distribution are significantly influenced by powder blowing parameters, and reducing the powder feeding rate and increasing particle size can help reduce erosion downstream of the nozzle divergent section.