Object tracking based droplet characterization of high flowrate electrospray

Abstract

Electrospray was applied to the wet electrostatic precipitator to reduce the water consumption of high-efficiency fine dust collection. The size of droplets must be large to avoid evaporating quickly under high temperature exhaust gas conditions, so a high flow rate condition of several milliliters/min is used, which is relatively high compared with previous applications. Because a high flow rate electrospray has a wide spray range and a low spray density, image-based droplet size measurement was used. A bias in the probability in the distribution occurs because of the difference in velocity between the droplets. In this study, an approach with object tracking was suggested to eliminate the bias from velocity differences. High flow rate electrospray droplets under various voltage conditions were visualized with a high-speed camera. Based on the image processing, the corrected distribution was characterized, and the effect of the bias was established through comparison with the general distribution. In addition, the spray pattern and the droplet distribution according to the applied voltage of three spraying modes were analyzed. Improved analysis of the actual spray using this approach will guide the selection of operating conditions that optimize dust collection efficiency.