Effect of barbed tubular electrode corona discharge EHD flow on submicron particle collection in a wide-type ESP

Abstract

In an electrostatic precipitator (ESP), the electrohydrodynamic (EHD) flow induced by the corona discharge is formed from the coupling of ionic wind and primary flow. This kind of non-laminar flow has a notable impact on submicron particle collection. The barbed tubular electrode is commonly used in industrial dust removal due to its high corona discharge intensity and fine particle collection efficiency, as well as its low inception voltage. However, the specific EHD flow functionary mechanism induced by the ESP's corona discharge for the purpose of submicron particle movement and collection has yet to be evaluated. In this work, a Particle Image Velocimetry (PIV) system was used to investigate EHD flow characteristics under this type of corona discharge. The experimental variables included barb tip orientation (in observation planes), primary flow velocity, and applied voltage. Based on the submicron particles' force and the entire flow field's velocity distribution within the ESP, we proposed two mechanisms for this type of corona discharge—“vacuum vortex obstruction” and “high-speed flow driven deposition,” and determined that submicron particle re-entrainment is closely related to both phenomenon.