Fog collection on a superhydrophilic wire

摘要

Fog collection shows great promise as a solution to the water scarcity problem in some arid regions. In addition, it can be applied to saving water required for important industrial system processes, such as recapturing water in cooling towers of thermal power plants. Although a number of studies have been conducted to investigate the principles of fog collection, most of the studies have sought methods to facilitate the transport of the captured liquid on multiple wire systems. However, it is important to study the fundamental correlation between the fog collection rate and the process of fog droplet capture, which has been largely underexplored, in order to understand the full span of the fog collection process and improve its collection efficiency. In this study, we aim to examine the correlation between the measured collection rate and the deposition step of fog collection on a wire, using spontaneous wetting of vertical, superhydrophilic wires that minimize the liquid loss during transport to precisely measure the volume of collected water. Experiments were conducted using the wires with various diameters under different wind speed conditions. The results show that the measured fog collection rate per unit area is linearly proportional to an empirically obtained deposition efficiency of aerosols, a function of the Stokes number. In addition to the controlled liquid transport by the modification of surface wettability, this study provides physical insights for the optimal design of fog collectors from an aerodynamics-centered perspective, benefitting the fight against the global water crisis. Published under license by AIP Publishing.