Novel cross-flow electrostatic precipitator: Numerical and experimental study

Abstract

ABSTRACT Electrostatic precipitators (ESP) are used extensively for removing particulates from a gas flow by charging the particles and then removing them in the presence of an electric field. Traditional ESP designs use the walls of the flow channel as the grounded collection surface. The objective of this present study is to evaluate a novel ESP configuration, recently patented by Ohio University’s Electrostatic Laboratory, in which an array of vertical surfaces of cylindrical geometry are placed in a crossflow configuration and used as grounded collection surfaces. A numerical approach was adopted by developing and implementing User-Defined Functions (UDFs) in ANSYS Fluent computational fluid dynamics (CFD) software to build a two-dimensional cross-flow ESP model, for the first time, for the gas flow and particulate capture. The two-dimensional numerical models proved useful in shedding light on the basics of the collection process in the novel cross-flow ESP. In the studied configuration, the collection of the particles on the collector surface was limited to the anterior and posterior surfaces of the first and second collection rows, respectively. The collection at the posterior surface of the second row presented interesting behavior, with the particles becoming entrained in the wake of the collectors and the electric field from the discharge electrode located downstream that was opposite to the fluid flow direction. The output of the simulation underestimated the experimental data. The lower efficiency prediction of the model could have been due to the vibration of the collection electrodes, collection by the mist formed in the wet system, and particle agglomeration in the experiments. The results of this study provide critical information in improving the particulate efficiency of novel cross-flow ESP and other similar cross-flow ESP systems. Implications: A novel Electrostatic precipitator (ESP) configuration (recently patented) was evaluated. A numerical approach was adopted to build a cross-flow ESP model, for the first time, for the gas flow and particulate capture. The collection of the particles on the collector surface was limited to the anterior and posterior surfaces of the first and second collection rows. Also, the particles were entrained in the wake of the collectors. The output of the simulation underestimated the experimental data. The results of this study provide critical information in improving the particulate efficiency of novel cross-flow ESP and other similar cross-flow systems.