An experimental study on the efficacy of modifications in enhancing the performance of single basin double slope solar still

Abstract

This study aimed at enhancing the distillate production or productivity of double slope single basin solar still. In the conventional type still, internal and external modifications were attempted. Three solar stills with internal modification such as still with finned corrugated basin, still with black granite and still with wick were designed. Another still with external reflectors (external modification) was also fabricated. Finally, one still incorporating all the above internal and external modifications was constructed. The experiment was conducted at Villianur, Pondicherry during the months of March, April and May 2018. The performance of the conventional still and the five different stills with modifications was analyzed. The increase in water temperature was quick in the still with finned corrugated basin and still with external reflectors during the increasing sunshine hours. The still with black granite sustained higher water temperature for a longer period during the declining and off sunshine hours. The proportion of forenoon production was more in stills with external reflectors. Black granite enhanced the afternoon and night production. The distillate collected from the conventional still was 1880 ml/m2·d. The distillate production of the still with finned corrugated basin, still with black granite, still with wick, still with reflector and still with all internal and external modifications was 2995, 3210, 2690, 3655 and 5130 ml/m2·d respectively and it was 58.47%, 69.84%, 42.33%, 93.39% and 171.43% respectively higher than the production of the conventional still. The impact of basin water temperature and water-glass temperature difference on production rate was also examined. Finally the experimental values were compared with theoretical values.