Electrode Configuration and Polarity Effects on Water Evaporation Enhancement by Electric Field

Abstract

Applying an electric field to some water solutions or food materials has been shown experimentally to increase the drying rate. In this work, an electric field was applied cross the interface of water via electrodes located upright above the water and under the water container. The polarity and the strength of the electric field and the shape of the electrodes were altered to investigate their effect on the water evaporation rate. The results show that the water evaporation rate in AC field is higher than that in DC field, indicate that the AC field have more effect in water evaporation and heat transfer than DC field. With respect to the effect of electrode configuration, the evaporation rate in the point-to-plane electrode configuration is higher than that in parallel plate, wire-plane, and tube-plane electrode configurations. The point electrode with conical end has more effect on the enhancement of water evaporation rate than that with hemispherical end and flat end. Larger the curvature of stressed electrode lead to higher water evaporation rate. However, the diameter of the rod has little effect on the evaporation rate. Both grid and plate can be used as the grounded electrode where the water samples placed, the mesh number of grid has little effect on the water evaporation rate.