The transformation from a macroscopic 1D light trapper to a 3D light trapper and the siphoning effect on the desalinating evaporator

Abstract

To verify the existence of the macroscopic 3D light trapping effect, a 3D light trapper with a 1D light trapping effect+3D light trapping effect was constructed. By exploiting and increasing the horizontal light path in a 1D light trapper-based system, the solar absorbance indeed increases from 96.51 % for a 2 mm gap to 99 % for a 14 mm gap. In addition to the macroscopic light trap effect, the salt accumulation deposited on the outer wall of the previously fabricated 3D-cup shaped device appears to be a salt layer that loosely adheres to the wall of the device, which is beneficial for recovering the steam generation performance of the evaporator by easily scraping out the layer of salt accumulation via the steel rule. The salt accumulation trend of the previously fabricated 3D cup-shaped evaporator is presumably driven by the siphoning effect and capillarity, which is also confirmed by adjusting the water head to 1.5 and − 1.5 cm. The evaporative interface for the 1.5 cm group lacks a siphoning effect, and its water supply is insufficient for evaporation. For this reason, the evaporative interface for the 1.5 cm group was rapidly dried and discontinued to work until the 40th hour. Nevertheless, the siphoning effect can not only supply adequate brine water to the evaporative interface but also form a salt layer on the outer surface of the device at the 7th hour for the −1.5 cm group. As time progresses, the salt layer becomes thicker and loosely adheres to the surface, which can be easily scraped out by a blade. In addition, through hydrophobic modification of the inner evaporative surface, the Janus device forms a looser salt accumulation layer than does the normal hydrophilic device, which can be more easily scraped out and collected than can the normal hydrophilic device.