Visualization and Droplet Characterization of High Flow Rate Electrospray for Wet Electrostatic Precipitator

Electrospray refers to a phenomenon in which a fluid passing through a nozzle is sprayed in the form of droplets by electrostatic repulsion when a high voltage is applied to the nozzle. Unlike the previous research focused on the cone jet mode, the electrostatic spray for particulate matter collection from power plant exhaust gas uses a high flow rate that is dozens of times higher leading to the distinctive spraying modes. It is important to observe the spray range and the size of spray droplets to improve the dust collection efficiency through colliding and agglomeration with fine dust particles. In this study, the shape and distribution of the electrospray under a high flow rate was visualized. An image processing software was used for the spray droplet photos to characterize the electrospray. The photos were captured using the shadowgraph technique with a high-speed strobe. From the analysis, the droplet diameter was measured, and the statistical distribution was characterized by applying a certain voltage.