Improving the vertical solar distiller performance using rotating wick discs and integrated condenser

Abstract

Freshwater is one of the most essential needs of society. Due to the limited amount of potable water on Earth, guaranteeing the supply of clean water to society is a major challenge. By utilizing abundant sunshine, solar still could be utilized to provide the necessary amount of drinking water in remote locations. The issue of restricted daily production inspires researchers to investigate novel ways for enhancing the thermal performance of desalination techniques while lowering expenses. In this work, the scholars improved a unique distillation method related to solar stills. The authors presented a novel improvement to the vertical distiller design to enhance the exposure area while decreasing the thickness of the water layer as much as possible. Thus, two rotational discs (flat type) covered with wick were integrated into the vertical distiller basin at 1.5 rpm and 5 cm water depth. Furthermore, providing vacuum via a fan with an external condenser. Besides, various rotating speeds (from 400 to 2000 rpm) were tested to determine the perfect fan speed that provides the maximum yield. The experimental findings revealed that the modified vertical distiller produced more pure water than the conventional distiller. Moreover, the rotation of wick discs and vacuum fan enhanced the yield of distillers enormously. Besides, the highest distiller performance was obtained at 1.5 rpm (wick disc speed) and 1600 rpm (fan speed, 10 min ON, and 10 min OFF). Moreover, the daily freshwater output was 19.1 L/m² day for MDSVD without the fan and 23.65 L/m² day for MDSVD with the fan. So, the yield of MSSVD without/with vacuum fan was improved by 548.65% and 660.45%, respectively, over that of CTD. The best thermal efficacy for MDSVD without/with vacuum fan was 77.47% and 84.05%, respectively. Lastly, the average cost of freshwater was 0.021, 0.0177, and 0.0164 $/L for CTD, MDSVD without/with vacuum fan, respectively.

Keywords: Desalination; Rotating parts; Saline water; Vacuum fan with an external condenser; Vertical disc solar still.