Comparison of Mechanical Vapour Compression Evaporator Technologies

Abstract

The energy efficiency, heat exchanger area requirements, and solids handling performance of Mechanical Vapour Compression (MVC) evaporation were compared to a proposed evaporator configuration called Mechanical Vapour Compression Flash Distillation (MVC-FD). Steady-state models were developed for both systems, and their thermal performance was compared. It was found that the MVC-FD configuration significantly increases specific energy consumption and heat exchanger requirements when compared to the standard MVC configuration. A steady-state bulk fouling model was developed for CaSO4-H2O-NaCl to determine whether fouling is reduced using the MVC-FD configuration. It was found that fouling is increased in this system due to the solubility properties of CaSO4. Fouling was also examined for the NaCl-H2O fluid system. It was found that the fouling can be substantially reduced by the MVC-FD system because fouling in this system is driven primarily by liquid volume change.