DESALINATION SYSTEM OF SWEEPING GAS MEMBRANE DISTILLATION COMBINED WITH JET IMPINGEMENT CONDENSATION

An experimental study of a desalination system that combines sweeping gas membrane distillation (SGMD) and jet impingement condenser (JIC) was conducted to evaluate freshwater production and system performance. Air was used as a gas carrier of water vapor from the SGMD unit to be delivered to the JIC unit. An air compressor and vacuum pump were tested to investigate the effects of air injection or suction in the sweeping air channel of the membrane distillation unit. The results showed that using a vacuum pump significantly improved the freshwater production rates and system energy performance compared to other carrying mechanisms. To optimize the design of the SGMD-JIC combined system, the influence of various parameters were analyzed, including the air flow rate, aperture diameter, aperture-to-surface distance, and coolant temperature. The permeate flux and specific thermal energy consumption (STEC) were obtained. The optimum permeate flux and STEC obtained was 44 kg/m²h and 1082 kWh/m³, respectively, at 0.75 CFM air flow rate, 1.5 mm aperture diameter of 14 mm aperture-to-surface distance, and coolant temperature of 5 °C. The experimental findings demonstrated superior performance in comparison to state-of-the-art techniques utilized in SGMD technology. The current study can be used to optimize the design and operating conditions of a jet impingement condenser. Additionally, the experimental data obtained provide an invaluable tool for future numerical modeling of the problem for better insights into the phase-change heat and mass transfer of the SGMD-JIC system.