Evaporation of Binary Mixtures in a Pillow Plate Thermosiphon Reboiler

Pillow plate heat exchangers show promising performance in extending the operating range of thermosiphon reboilers. Here, the evaporation of binary mixtures during natural circulation evaporation in a pillow plate apparatus was investigated. The experimental results show that the thermal performance is dominated by mixture effects and a component system-dependent minimum is found. The model approach according to Bennett and Chen has proven to reliably estimate the product-side heat transfer coefficient for pure substances and mixtures with a low boiling point distance. For wide-boiling mixtures and low pressures the approach must be adjusted.