Steady-state experimental study of a closed recycle solar still with enhanced falling film evaporation and regeneration

An active regenerative solar still with an area of 1.03 m2, enabling one to reuse the latent heat of condensation and sensible heat of brine, is constructed and tested indoors, using a solar simulator for irradiation. In this still, a considerable fraction of the latent and sensible heat is successfully recycled and utilized for preheating the feedstock and recycling air via a falling film evaporator–condenser. The forced thin layer evaporation and film condensation, which are the efficient enhanced processes for heat transfer, are applied in this unit. As a result, the performance ratio of the unit is about two to three times greater than that of a conventional basin-type solar still (single-effect).