Experimental investigation of spherical salt balls effect on solar distillers’ thermal performance at various water depths

In this research, a single slope solar distiller was fabricated and tested under the climate of Al- Hilla city, Iraq, with a tilt angle of 32.5° according to its latitude. The experimental tests were done in November 2021. Two types of distillers were examined, the first one was a classical type, while the other one was modified by adding twenty-five spherical salt balls in its basin. Furthermore, the impact of the water depth (1.5 and 2 cm) was also investigated. Therefore, two cases were tested as follows: 25 spherical salt balls for 1.5 cm water depth (Case 1) and 25 spherical salt balls for 2 cm water depth (Case 2). It was found that using salt balls has a good role in increasing the productivity of modified solar distillers. Also, the daily accumulated productivity of modified solar still (MSS-SB) for Case 1 was higher than for Case 2 and classical solar distiller by about 8.06% and 17.45%, respectively. The results show that the maximum productivity was attained by MSS-SB Case 1, which was 1568 g/m², followed by 1451 g/m² for MSS-SB Case 2, and 1335 g/m² for classical solar still. Finally, a minimum depth of basin water should be used with salt balls to increase the efficiency of the solar still.