Development of a Novel Electrostatic Precipitator System Using a Wet-Porous Electrode Array

Abstract

The authors introduce a novel electrostatic precipitator using a wet-porous electrode (WPE) array, for application to various work processes (e.g., molding and extrusion), to improve the removal performance of ultrafine particles and water-soluble gaseous pollutants generated during manufacturing. The WPE array electrostatic precipitator (WPE-ESP) consists of an ionization component for particle charging and a collection component equipped with the WPE array to maintain a high humidity environment. The performance of the WPE-ESP was evaluated in terms of the removal efficiency of airborne particles and water-soluble gases under ESP operating conditions in which the ionization charge current, the applied electric field strength of the collection component, and the relative humidity (RH) were varied. The collection efficiency of the WPE-ESP was enhanced by increasing the RH, due to water adsorption on the particle surface and the enhanced electric field strength near the collecting plate. The maximum total collection efficiency of the ESP system was~99.2% for a 73% RH collection environment, which was approximately 3.3% higher than that of conventional dry-type ESP (C-ESP). The proposed system also removed sulfur dioxide (SO 2 ), a representative source (90.7%) of undesirable emissions during manufacturing processes, and mitigated ozone (O 3, <10 ppb), a by-product of the corona discharge in the ESP, regardless of the field strength. The proposed WPE-ESP included a simple mounting system; additionally, the system generated a more uniform water film than that of wet-ESPs. Thus, the WPE-ESP shows great potential for application to workplaces and machining devices that require the simultaneous removal of ultrafine particles and water-soluble gaseous pollutants.