Numerical investigation of vanadium distill-condensation via computational fluid dynamics

A coupled VOF-Species Transport-Discrete Phase numerical framework incorporating user-defined condensation source terms (UDFs) is developed to investigate the multiphase condensation behavior and impurity migration of VOCl₃ mixed vapors under nitrogen-protected conditions. The spatial evolution of vapor-liquid interfaces, heat and mass transfer, and particle transport is systematically analyzed. The results show that condensation is initiated at localized interfacial regions near the cooled wall and gradually evolves into continuous liquid film growth along the flow direction, leading to a transition from interfacial-controlled to diffusion-controlled condensation. The accumulation of non-condensable nitrogen thickens the diffusion boundary layer and suppresses condensation, while enhanced wall subcooling strengthens the thermal driving force. Their competition governs the spatial non-uniformity of condensation intensity. The synchronized attenuation of Nusselt and Sherwood numbers confirms the coupled heat and mass transfer mechanism. Most solid particles are transported along gas streamlines, yielding outlet recovery rates above 99%, whereas slight particle enrichment near the liquid film suggests a weak interception effect. These findings provide guidance for optimizing industrial distillation - condensation systems.