Deconstructing plasma fog collection technology: an experimental study on factors impacting collection efficiency

Abstract

Water scarcity is a global challenge that hinders human development. In recent years, electrostatic fog collection technology has emerged as a promising technology to alleviate this issue. Although electrostatic fog collectors based on a variety of electrode structures have been developed previously, there has been less research into other factors affecting the efficiency of electrostatic fog collection (e.g. electrical factors, environmental factors, etc), which has delayed the commercial application of the technology. In this paper, we experimentally investigate the effects of power supply polarity, voltage, airflow direction, airflow velocity, fog concentration and temperature on collection efficiency using a typical wire-mesh electrode fog collector as an example. The results show that both electrical and environmental factors influence the collection efficiency by changing the charge and the electric field force of the droplets. Negative polarity corona and high voltage are more favorable for fog collection. High velocity airflow and high fog concentration increase the amount of water collected due to the ability to bring more droplets into the electric field. However, the collection efficiency is reduced by the weakening of the corona discharge. High temperature accelerates the evaporation of fog droplets, which is not favorable for fog collection. In conclusion, this work will not only contribute to revealing the underlying mechanisms of the electrostatic fog collection but also will guide the development of highly efficient fog collectors.

Advanced Fog Harvesting Method by Coupling Plasma and Micro/Nano Materials

“…A typical EFC consists of one discharge electrode (also known as corona electrode) and one collecting electrode, as shown in Figure a. , The former requires a conducting electrode with a minimal curvature radius and high voltage to trigger gas discharge, then produce abundant charged particles to charge fog droplets . The charges carried by micron-sized droplets can be obtained by q = 12π R d 2 ε 0 E , ,, where, R d , ε 0 , and E represent the droplet radius, vacuum dielectric constant, and electric field strength, respectively.…”