Impact of Lance Bending Failure on Bath Dynamics of Top-Submerged Smelting Furnace for Non-ferrous Metals

Lance bending failure is a pervasive issue in top-submerged lance (TSL) smelting furnaces employed in the processing of non-ferrous metals, while the impact of lance bending failure on bath dynamics remains insufficiently understood. This study utilizes a volume of fluid multiphase flow model to elucidate the effects of lance bending on the velocity field, stirring zone, splashing behavior, and wall shear stress within the bath of a top-blown smelting furnace. The findings demonstrate that lance bending significantly disrupts the flow regime within the bath, resulting in the breakdown of uniform melt velocity distribution and a substantial reduction in melt velocity. The altered flow dynamics lead to a lateral shift in the stirring region toward the direction of the bending, culminating in a 53.9% reduction in the volume of the stirring zone. Furthermore, the Coanda effect exerted on ascending gas bubbles becomes increasingly prominent as the bending angle grows, with bubbles adhering to the lance wall on the bending side, consequently inducing melt splashing in that direction. Overall, a bending angle of 3° is identified as the upper permissible limit during the smelting process, beyond which further increases in bending angle lead to diminished gas-phase stirring efficiency. These insights provide critical theoretical guidance for optimizing the TSL furnace smelting process while mitigating the risks and associated losses arising from lance bending failure.