Effect of Relative Humidity on the Collection Efficiency of a Wire-To-Plane Electrostatic Precipitator

Abstract

This paper aims to analyse the influence of the atmospheric relative humidity level (RH) on the collection efficiency of a wire-to-plane electrostatic precipitator (WP-ESP). The experiments were performed with incense smoke particles having a mean size of about 0.28 µm. An aerosol spectrometer was employed for characterizing the size distribution of these particles at the outlet of the ESP. Then, the total and fractional collection efficiencies were estimated for different relative humidity levels ranging from 40 to 70 %. Various DC applied voltages in the case of positive and negative polarities have been under consideration. For given atmospheric conditions, the results obtained with the aerosol spectrometer show that the performances of the ESP increases with the applied voltage (range: 10 to 40 kV) and the particle diameter (range: 0.2 to 0.7 µm). The collection efficiency is higher at increased RH. The negative corona discharge is overall more effective than the positive one. However, the difference between the two polarities becomes minor at high RH.

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

“…As shown in Figure 4b, the collection efficiency increased with the RH. Specifically, for a 300-nm particle diameter, the collection efficiency increased by 50.4%, 77.8%, and 97.3% (p D 0.049), under RH conditions of 42%, 62%, and 73%, respectively, in good agreement with the results from previous studies (Nouri et al 2010;Chen et al 2014). The increase in the RH of the surrounding ESP enhanced the particle cohesiveness to the collecting plates, due to water adsorption on the particle surface.…”

“…Moreover, a wet-ESP can maintain its particle removal capabilities over the long term, due to the water film on the collection plate of the ESP that continuously removes the adhered dust (Lin et al 2010;Nouri et al 2010;Lin et al 2013). Especially, under high-humidity conditions in ESP, the particle cohesiveness increases due to water adsorption on the particle surface, and the electric field strength is elevated near the collecting plate, which improves the collection performance of ESPs (Nouri et al 2010;Bian et al 2011;Wang and You 2013;Chen et al 2014). Dor et al (1998) investigated two wet-ESP geometries: a wire-to-plate geometry and a multineedle-to-plate geometry; a suitable electrode arrangement for NOx removal was suggested.…”

Analysis of electric field and current density in an electrostatic precipitator

“…The basic principle of operation of an electrostatic precipitator, as already indicated, is that the gas borne particles are passed through an electric field where they are initially charged by means of a corona discharge and then, as a charged particle, are deflected across the electric field to migrate and be deposited on the collection or receiving electrodes [8].…”