Numerical Simulation and Improvement of TSL Smelting Process: the Effect of Lance Bending

The lance is the heart of Top-Submerged-Lance (TSL) furnace and is also the most vulnerable part. A numerical simulation model was developed to study the TSL smelting process with a bending lance, and the effects of the bending angle on the flow field, the fluctuation and splashing, and the mean shear on the walls of the lance and the furnace body were analyzed. A VOF multi-phase model coupled with a Realizable k-epsilon turbulence model was adopted in this work. The simulation results reveal that the bending lance leads to asymmetrical flow field distribution, severer interface fluctuation, significantly higher slag splashing and mean shear stress on the walls of both lance and furnace body. The maximum instantaneous splashing quantity with the bending lances was increased by 33.3% compared to the vertical lance. An improvement by lance rotation on furnace operation was simulated to mitigate the effect of lance bending. Compared with the result of the original vertical lance, a smaller mean shear on the lance wall was achieved for a rotated lance.