Abstract
This comprehensive study employed a new design of drum solar still which keeps the basin water depth constant using constant head tank. Three solar stills nominated as drum solar still (DSS), modified drum solar still (MDSS), and conventional solar still (CSS) were tested under the same environmental conditions to be able to compare between their performances in fair. Both DSS and MDSS had a free to rotate drum fixed on a rotating shaft run by a DC motor. A PV system was used to eliminate the use of the traditional sources of energy. Besides, the effects of using a flat-sheet glass cover instead of the semi-circular shape, mirrors on the rear high-wall, front small-wall from glass sheet, and nanoparticles on the performance of MDSS were investigated. Various drum speeds were tested to point out the optimum speed of rotation for the MDSS with and without wick. Results revealed that the MDSS obtained better performance than that of the other solar stills. In addition, the drum speeds 0.05 and 0.1 rpm were the optimum speeds for MDSS with and without wick, respectively. Besides, at 0.1 rpm, the productivity of the MDSS with reflectors and nanofluid was increased by 296% more than that of the CSS. While the maximum productivity rise obtained for MDSS with wick at of 0.05 rpm was 280%. Also, the cost of 1 L from the CSS and MDSS was 0.05 and 0.041 $, respectively.