Gas–slag–matte multiphase flow and bubble dynamics in an industrial side-blown smelting furnace

In present employment, computational fluid dynamics is employed to investigate the jet–slag–matte multiphase flow characteristics in a side-blown smelting furnace. The volume-of-fluid multiphase flow model is introduced to analyze the in-furnace hydrodynamic behavior, bubble morphology, and interfacial mixing performance, with a discussion of the effects of installation height of the tuyere and mass flow rate of the jet on flow behavior. In addition, the accuracy of the numerical model is verified by constructing a 1:10 physical water model. The results indicate that bubble dynamics are predominantly impacted by the turbulence intensity in the vicinity of the gas–slag interface. In regions with high cell Reynolds number (Rec), the bubble breakup and deformation are induced by shear forces, whereas buoyancy-driven spherical bubbles can be observed in regions with low Rec distribution. The molten below the nozzle is agitated by the jet with a slight velocity. The mass flow rate of the jet exerts a nonlinear effect on bubbling frequency, with a critical value at which the bubble frequency peaks. The fitting relationship between jet mass flow and bubble frequency has been found. When the installation height of the tuyere increases from 1500 to 1900 mm, the volume of the stirring dead zone expands. However, when the installation height of the tuyere is larger than 1900 mm, the dead zone volume decreases due to the surface entrainment mechanism. Raising the nozzle height also reduces the splashing volume of the slag phase, thus enhancing the stability of the flow field.