The efficiency of corona wind drying and its application to the food industry

This work pertains to a novel drying method, the 'corona wind', and looks at the potential to optimise a corona wind blower for application to the food industry. The corona wind is a method of inducing forced convection by ionic injection and subsequent acceleration between two electrodes. The wind velocity of a blower was found to be proportional to the voltage applied for specific electrode spacing and with cube root proportionality to the electrical power used. The power consumption was shown to be independent of the electrode spacing, allowing a generic calculation for a corona wind blower in air of 1.5% conversion of electric energy into kinetic energy. This low energetic efficiency is offset by the unique properties of the corona wind, which allows the wind to be directed. Experiments using the corona wind to evaporate water from paper towels and biscuits shows significant drying enhancement at an overall efficiency comparable to convention drying methods. The caveat is that the arrangement of electrodes is crucial for effective operation. (c) 2006 Elsevier Ltd. All rights reserved.