SOME EXPERIMENTAL AND THEORETICAL-STUDIES OF A SINGLE BASIN SOLAR-STILL

This paper consists of experimental and theoretical results carried out on a single basin solar still under various modes of operation. The solar still was located in Nag Hammadi (latitude = 26-degrees-14'N, longitude = 32-degrees-E and altitude = 90 m), Egypt. The variations of daily distillate with basin water mass and salinity have been measured for the simple still. The effects of: (i) film distillation with and without addition of a small quantity of black dye to the basin water and; (ii) flat plate collector coupled to the still with film distillation and black dye operating on the thermosyphon circulation mode, on the daily distillate of the solar still were also studied. The best performance was found in the case of the coupled still under thermosyphon circulation using film distillation with black dye. The measured monthly average variations of the total solar radiation on a horizontal surface in Nag Hammadi were compared with those variations calculated using ASHRAE and Hottel models. Numerical calculations have been carried out for a typical cold and hot day, 22 November 1992 and 11 June 1993, in Nag Hammadi to predict the hourly variations of distilled water for a simple single basin solar still.