Experimental investigation of modified solar still integrated with solar collector

Abstract

The limited productivity of traditional solar still considers as one of the most prominent obstacles to their implementation. Thus, the main objective of this study is to improve traditional solar still (TSS) productivity in two successive stages. In the first stage, a rotating hollow cylinder is used within the solar still to increase the surface area of evaporation and reduce the boundary layer thickness of untreated water film. Three rotational speeds have been tested (0.5, 1 and 3 rpm). The second stage included the integration of an external solar collector with the modified solar still (MSS) to raise the basin saltwater temperature. From the analysis of experimental results, it is observed that the productivity increased with decreasing rotational speed of a hollow cylinder and the maximum value obtained at the lower speed (0.5 rpm). Furthermore, integrating outer solar collector results in further enhancement, where the productivity of freshwater observed to be 5.5 L/m2 for MSS compared to 1.4 L/m2 from TSS. Accordingly, the productivity enhanced by 292% at an estimated cost to produce 1 L of freshwater of 0.048 $ and 0.049 $ from MSS and TSS respectively. Keywords: Modified solar still, Traditional solar still, Solar collector, Freshwater water productivity