On the Fluid Dynamics in Wiped Film Evaporators during Evaporation

This dissertation investigates the separation of viscous and temperature-sensitive mixtures in wiped-film evaporators (DSV). Experimental studies with pure substances and binary mixtures were conducted to determine thermophysical properties and analyze fluid dynamics, particularly residence time distributions under different operating conditions. The results show that viscosity and density strongly influence residence time, while film rupture and dewetting can significantly increase it. In addition, a mechanistic Modelica model was developed to simulate heat transfer, evaporation, and fluid flow in the evaporator. The model shows good agreement with experimental data and provides a basis for improving predictive modeling and optimizing processes for temperature-sensitive materials.