EXPERIMENTAL INVESTIGATION ON CONCENTRATOR-ASSISTED SOLAR-STILLS

The performance of a simple basin solar-still and a similar still coupled to an external trough type concentrator is investigated. The stills are basin-mounted inverted-V roof type, 1.67 m² area each. The assisting concentrator is a single trough-type finned tube 840 cm² receiver area with an adjustable trough half angle. The receiver tube and the basin form a thermosyphone closed loop generating a weak motion of the saline inside the stilt basin. Experiments have been conducted at Jeddah, Kingdom of Saudi Arabia ( Latitude 21^°45') for an average daily solar flux 300–500 w/ m² with water levels of 5–7 cm. A single correlation to predict the stills yield is obtained on basis of data for stills of different compass orientation. The productivity of the assisted still is 22% higher than that of the simple still under the same climatic conditions. For the present results, with fixed concentrator inclination, variation of the trough half angle has no appreciable effect upon the distillation process.