Solar Still Efficiency Augmentation using Cylindrical Sweeping Agitator on the Absorber Plate

Passive solar stills are simple devices which generate potable water by way of desalination of brackish water. However, the main limitation of this device is its poor still efficiency. This paper presents an innovative technique of increasing the still efficiency using the sweeping agitator system in the passive solar still device. The agitator rotates on the still basin plate thereby sweeping the water on the plate and enhances mixing which results in increased heat transfer. The experiment is carried out on a single slope passive solar still in the outdoor conditions of Dubai during the month of May. The presence of sweeping agitator is shown to be effective in enhancing the distillate output as well as solar still efficiency. The results show that the solar still efficiency increased by about 3.95% as compared to base still.