Particle removal performance of a two stage electrostatic precipitator with carbon based nonmetallic collection plates for oil mist

Abstract

The electrostatic precipitator, one of the air pollution control devices, is widely applied in industrial fields due to the low differential pressure and high particle removal efficiency. However, the electrostatic precipitator use high voltage leading to the risk of unstable sparks and corrosion. As a solution to this challenge, two-stage electrostatic precipitators that separates the pre-charging and collection stages have been developed, but expensive anticorrosive metals are required. In this study, we developed a carbon based non-metal two stage electrostatic precipitator to investigate the particle removal performance for oil mist. Five types of collection modules were manufactured by varying the materials of the high voltage and ground electrodes, and the particle removal performance depending on the flow velocity, particle diameter, and applied voltage was evaluated for each collection module. For the present experiment, there was no significant difference in particle removal performance regardless of electrode material. We confirmed the average electric field strength for each electrode material through numerical analysis. As a result, the non-metal electrode also showed an electric field strength similar to that of the metal electrode. The experimental results corresponded to the electrostatic precipitation theory, the Deutsch equation and Cochet's theory, and showed the maximum removal efficiency of PM2.5 at 91.5% at 3 m/s, the fastest flow rate in this experiment. Carbon is lighter, cheaper, and more anticorrosive than general metals. Therefore, the characteristics of the carbon based non-metal electrostatic precipitator introduced in this study are expected to be applied to industrial post-treatment facilities.