Experimental study on water collection performance of wire-to-plate electrostatic fog collector at various fog generation rates and fog flow velocities

Abstract

Electrostatic fog collectors can assist in alleviating water scarcity by recovering water from fog in natural or industrial environments. Therefore, a wire-to-plate electrostatic fog collector is proposed in this study. To achieve this, an electrostatic fog collector experimental test system is established. The effects of voltage, fog generation rate, and fog flow velocity on the current and collection performance of the electrostatic fog collector are investigated experimentally, and its performance coefficients are evaluated. The water collection rate is primarily determined by the rate of fog generation, the size distribution and evaporation of fog droplets, and the collection capacity of the electrostatic fog collector. The fog droplets limit the charge transfer within the electrostatic fog collector. The evaporation of the droplets tends to reduce the rate of water collection. The voltage and fog flow velocity affect the collection capacity. The higher collection capacity can be obtained by increasing the operating voltage, associated with an increased electric force on fog droplets, or by lowering the fog velocity for a longer residence time. The proposed electrostatic fog collector can meet the energy requirements for industrial applications. The experimental results demonstrated that the electrostatic fog collector achieves a maximum collection efficiency of 60 % when the voltage is 24 kV, and the fog flow velocity is 1.06 m/s. Furthermore, an advantage over reverse osmosis desalination is obtained under a more favorable operating range. At a voltage of 20 kV, a superior performance coefficient of 388.8 kg/kWh is obtained. The results suggested that the designed electrostatic fog collector can effectively recover water from the fog.