Iron Sand as a Heat Absorber to Enhance Performance of a Single-Basin Solar Still

Abstract

Many researchers already use sensible materials to enhance the performance of solar stills, but only a few use iron sand as a heat absorber in single-basin solar stills to enhance the performance, as demonstrated in this experiment. The study was conducted in the period August–September 2018 and used four solar stills with dimensions of 420 mm × 305 mm and a cover with a slope of 30 degrees. Three of the solar stills contained iron sand 20 mm high. The height of water in the three solar stills was 15 mm (V1), 20 mm (V2) and 25 mm (V3), so that the surface of the water would be: below the surface of the iron sand, on the same level as the surface of the iron sand, and above the surface of the iron sand, respectively. The fourth solar still, filled with only 20 mm (P) of water, was a benchmark for the others. From the results, we inferred that the heat absorbed by the iron sand enhanced the total heat transfer coefficients inside the solar still. This result agreed with exergy and overall efficiency of solar stills. The results showed that the fresh water produced by increasing V1, V2 and V3 against P was 1.5%, 51.8% and 57.1%, respectively. Therefore, we conclude that iron sand significantly enhances the productivity of a solar still. The best result was obtained when the water surface was higher than the iron sand surface.