Developing a Compact Particle Collector by Integrating a Wet Electrostatic Precipitator and an Inertia Mist Eliminator

Zhengda Yang,Ye Jiang,Can Zhou,Yang Yang,Riyi Lin,Chenghang Zheng,Xiang Gao,Hongbo Qiu

doi:10.4209/aaqr.210209

Abstract

ABSTRACT Wet electrostatic precipitator (WESP) is a reliable alternative to realize the ultra-low emission of particulate matter from coal-fired power plants. This work proposes to develop a compact particle collector by integrating a WESP and an inertia mist eliminator (IME). The particle collection efficiency and charging characteristics of the WESP were analyzed to determine the potential for compact design. Results show that the WESP was easy to achieve a collection efficiency of 95% for both pin and wire electrodes. Particle charging can still be guaranteed with short WESP length and high voltage, indicating the particle charging was sensitive to electrical parameters. Charges carried by the escaping particles acted as a bridge between the WESP and the IME. The collision enhanced by particle charging can lead to an improvement in overall efficiency and charge loss. The particle charge loss of the particle sized 7.29 μm was 22.6% and 29.4% for the one and two stage IME, which coincided with the efficiency enhancement of WESP. The collection efficiency significantly decreased as the WESP size decreased, but the collection efficiency can be enhanced by the combination with IME. The 6-wire WESP enhanced by one-stage IME can be considered the optimal combination because the WESP size can be shorten by 40% while maintaining a similar efficiency. The research findings are beneficial for the retrofit of air pollution control devices in limited space.

Highlights

The pollutants of sulfur dioxide, nitrogen oxides, particulate matter (PM)discharged from energy utilization and conversion processes are crucial for the severe air pollution in recent years (Gao et al, 2018, Jiang et al, 2021, Ye et al, 2020).Recently, much attention is paid to particulate pollution because of the popularity of the PM2.5 concept (Chen et al, 2019).the PM emission standards become strict around the world
The PM emission concentration can be reduced below mg m–3 with Low-low temperature electrostatic precipitator (LLTESP) and electrostatic fabric filter (EFF) and even below 5 mg m–3 with the further assistance of highly efficient demisters equipped at the wet flue gas desulfurization tower (WFGD)
Prior to developing a novel particle collector, the performance of the wet electrostatic precipitator (WESP) was evaluated in terms of discharge characteristics and collection efficiency

Summary

Introduction

The pollutants of sulfur dioxide, nitrogen oxides, particulate matter (PM)discharged from energy utilization and conversion processes are crucial for the severe air pollution in recent years (Gao et al, 2018, Jiang et al, 2021, Ye et al, 2020).Recently, much attention is paid to particulate pollution because of the popularity of the PM2.5 concept (particle with diameter less than 2.5 micrometers) (Chen et al, 2019).the PM emission standards become strict around the world. Much attention is paid to particulate pollution because of the popularity of the PM2.5 concept (particle with diameter less than 2.5 micrometers) (Chen et al, 2019). In China, the PM in flue gases from coal-fired power plants and steel sintering is required lower than mg m–3 according to the latest ultralow emission standard (Cui et al, 2018, Yang et al, 2021). Low-low temperature electrostatic precipitator (LLTESP), electrostatic fabric filter (EFF), and wet electrostatic precipitator (WESP) are applied to realize the PM ultra-low emission (Li et al, 2019, Yang et al, 2019). The PM emission concentration can be reduced below mg m–3 with LLTESPs and EFFs and even below 5 mg m–3 with the further assistance of highly efficient demisters equipped at the wet flue gas desulfurization tower (WFGD)

Methods

Results

Conclusion