Influence of high porous sponges for improving the interfacial evaporation from hemispherical solar distillers

The present study aims to improve the palatable water production from the hemispherical cover solar distiller (HSD). To augment the palatable water produced from the hemispherical cover, a black sponge was utilized as a porous medium using different thicknesses, which augments the interfacial evaporation through the capillary effect of the water through the sponge. The rate of condensation of the hemispherical cover depends on the higher interaction of air from the ambient through wind velocity as the exposure area of the hemispherical cover is relatively higher as compared to the other traditional distillers. The rate of evaporation from the distillers depends on the interfacial materials used in the distillation unit, and this is achieved by using a highly porous black sponge to attain a higher evaporation rate. The thickness of the black porous sponge was optimized (1 to 4 cm), which was the operating parameter for better interfacial evaporation through the sponge, and the same has been compared to the conventional HSD without a porous sponge medium. Results showed a significant improvement in the evaporation rate using a porous medium as the palatable water produced from the HSD was improved by 72.29% using 3 cm as sponge thickness inside compared to the conventional HSD without the porous medium. The cumulative palatable water produced from the HSD using 3 cm as sponge thickness was found as 7150 mL/m², whereas the conventional HSD without sponge, it was found as 4150 mL/m². Moreover, using a porous sponge layer as an interfacial evaporation medium, the exergy and energy efficiencies were improved by about 512.87 and 70.53%, respectively. Similarly, with the influence of a porous sponge as an interfacial evaporation medium, the distilled water cost decreased by 41.67% more than the conventional HSD.