Water desalination with the concentrating mirror solar still
2018 – 2019
أ.د. أشرف سعيد
Single basin stills have low efficiency, generally below 45%, due to high top losses. Double glazing can potentially reduce heat losses, but it also reduces the transmitted portion of the solar radiation. The reflectors, either external or internal, are a good and cheap modification to increase the solar irradiation directed to the basin liner or the water as well as the distillate efficiency of the still. The concentrating mirror solar still uses a parabolic or flat mirror for focusing sunlight onto an evaporator vessel. The water is evaporated in this vessel exposed to extremely high temperature. The evaporator vessel in basin still consists of a basin, support structure, transparent glazing, and distillate trough. Thermal insulation is usually provided underneath the basin to minimize heat loss. Other ancillary components include sealants, piping and valves, storage, external cover, and a reflector (mirror) to concentrate light.
In the present project, solar still desalination system assisted with a reflector (mirror) to concentrate light is used for obtaining drinking water by a recommended design. A prototype for still integrated with external reflectors, fan, and external condenser is executed. The effect of solar radiation, mirror angle of inclination, and ambient air condition on the amount of obtained clean water, will be studied.