EHD-Enhanced Water Evaporation

Abstract

The enhancement of water evaporation by electrostatic field (corona wind) has been experimentally evaluated in this study. Two sets of experiments were conducted, with and without cross-flow, at an increment of 1 kV from the corona threshold voltage until the occurrence of sparkover. Two types of electrodes (wire and needle) were used. In addition, both positive and negative corona discharges were applied. The weight loss of water due to evaporation as well as the ambient temperature and humidity were measured. For each case a companion experiment was carried out simultaneously under the same ambient conditions but without the application of electric field. The result of which is used as a basis in the evaluation of the evaporation enhancement using electric field. Each experiment lasted for at least 5 h. With the application of electric field alone, the enhancement in the water evaporation rate increases with the applied voltage. With the introduction of cross-flow, the enhancement in the evaporation rate becomes nearly independent of the applied voltage and is close to the result obtained with cross-flow alone.