Solar Desalination and Hot Water Production Using A Falling Film Enhanced by Counter Current Air Flow

Solar desalination has been under investigation for long time via different methods based on thermal techniques. Recently solar energy is used to power membrane desalination. Among the thermal methods used solar stills, humidification/ dehumidification and solar ponds. The low productivity in most of the thermal methods triggered many attempts and modifications for improvements. It is the purpose of this study to utilize solar energy to desalinate water of various sources (brackish and sea water) flowing as a film over sieve trays fixed to an inclined surface acting as a solar collector. The falling water will be contacted by air flowing in a countercurrent fashion. The mode of evaporation, the increase in the water resident time, the flowing air carrying the evaporated water preventing attenuation of the solar energy are expected to improve the performance of the unit compared to previously designed units available in literature. Heat integration will be taken care of using the feed water as air cooling medium and by recycling the hot water to the feed tank.