Current density distribution and optimization of the collection electrodes of a honeycomb wet electrostatic precipitator

Abstract

Wet electrostatic precipitators (ESPs) demonstrate a robust adaptability for particulate matter control and have been confirmed to be a promising technology for removing particles and sulfuric acid aerosol from flue gas. Recent studies have shown that removing fine particles or sulfuric acid aerosol from wet ESPs requires further development. Among the components of wet ESPs, discharge electrode configurations are crucial for determining the performance of wet ESPs. This paper reports the corona discharge characteristics and removal performance of sulfuric acid aerosol using different discharge electrode configurations in a honeycomb wet ESP experimental system. Two key parameters, namely, V–I characteristics and current density distribution, with different discharge electrode geometries (e.g., electrode type, spike spacing, and spike length) and rotation angles, were investigated by using a novel electrical parameter measurement system to evaluate the effects of these parameters on corona discharge. The results showed that triple-spike and sawtooth electrodes exhibit the highest average current density. The average current density of the triple-spike electrode increased with the spike length from 10 mm to 20 mm, and the peak current density distribution on the collection electrode increased by 62.1%, but the current density decreased sharply away from the spike. Moreover, the average peak current density decreased by 30.1% when the spike spacing was 25 mm given the sharp point discharge suppression when spikes were significantly dense. The electrode configuration was optimized on the basis of the current density distribution. The highest removal efficiency of sulfuric acid aerosol was 99.2% at a specific collection area of 23.09 m² (m³ s⁻¹)⁻¹.