Wet Electrostatic Precipitator for Ultra-Low Industrial Emissions

A Wet Electrostatic Precipitator, commonly referred to as WESP, is a high-efficiency air pollution control device designed to remove fine particulate matter, acid mist, aerosols, water droplets, and other pollutants from wet or saturated flue gas streams. It is widely used in power generation, steel production, chemical processing, cement manufacturing, waste incineration, and other industrial applications where ultra-low emissions and stable operation are required.

Unlike conventional dry electrostatic precipitators, a WESP is especially suitable for treating flue gas with high moisture content. It is often installed downstream of wet flue gas desulfurization systems to further reduce particulate emissions, control acid mist, and minimize visible plume or “gypsum rain” phenomena.

How a Wet Electrostatic Precipitator Works

The working principle of a WESP is based on high-voltage electrostatic collection. The process generally includes three stages: particle charging, collection, and cleaning.

1、Gas ionization and particle charging  

   A high-voltage direct current field is applied between the discharge electrodes and collecting electrodes. The strong electric field causes corona discharge, generating a large number of ions that charge dust particles, mist droplets, and aerosols in the flue gas.

2、Electrostatic collection  

   Charged particles migrate toward the collecting electrodes under the influence of the electric field. Once they reach the electrode surface, they are captured and separated from the gas stream.

3、Wet cleaning without secondary dust  

   Instead of mechanical rapping used in dry ESPs, a WESP removes collected material by water spraying or a continuous liquid film. The captured dust and mist are washed into a collection sump, which helps prevent re-entrainment and secondary dust emissions.

Main Components

• A typical WESP system consists of the following components:

• Shell and gas distribution system to ensure uniform flue gas flow  

• Collecting electrodes, which may be plate-type, tubular, or honeycomb-type  

• Discharge electrodes for corona generation  

• High-voltage power supply and control system  

• Spray or flushing system for electrode cleaning  

• Mist eliminator and drainage system  

• Insulator protection system to maintain stable electrical performance

The equipment can be designed in vertical or horizontal configurations. Vertical tubular or honeycomb designs are commonly selected for compact layouts and high collection efficiency, while horizontal plate-type designs may be preferred in certain retrofit projects.

Key Advantages

• High collection efficiency  

  WESPs can effectively capture fine particles, including PM2.5 and submicron aerosols. Outlet particulate concentrations can be reduced to 10 mg/Nm³ or even below 5 mg/Nm³ in well-designed systems.

• Effective control of acid mist and aerosols  

  In addition to dust, WESPs help remove sulfuric acid mist, gypsum droplets, and other condensable pollutants from wet flue gas.

• No mechanical rapping  

  Wet cleaning avoids the secondary dust problem associated with dry ESP rapping systems, contributing to more stable emissions performance.

• Suitable for high-moisture flue gas  

  WESPs are designed to operate under saturated or near-saturated conditions, making them suitable for installation after wet desulfurization units.

• Compact structure and flexible layout  

  The equipment can be arranged as a standalone unit or integrated with existing flue gas treatment systems, depending on site conditions.

• Low pressure drop and stable operation  

  With no moving parts in the collection field, WESPs offer reliable long-term performance and relatively low maintenance requirements.

Typical Applications

Wet Electrostatic Precipitators are widely applied in industries with strict emission requirements, including:

Coal-fired and biomass power plants  

Steel mills, sintering lines, and coke oven gas cleaning  

Chemical and petrochemical plants  

Cement and building material production  

Waste incineration and hazardous waste treatment  

Non-ferrous metal smelting and acid plant tail gas treatment

They are particularly effective as a final polishing stage for flue gas treatment, helping plants meet increasingly stringent environmental standards and achieve ultra-low emission targets.

Why Choose Our WESP Solutions

Our Wet Electrostatic Precipitator systems are designed for industrial customers who require reliable emission control, compact installation, and long-term operational stability. Each solution can be customized based on flue gas volume, temperature, moisture content, pollutant characteristics, corrosion conditions, and site layout.

We support OEM, ODM, and project-based cooperation, and can provide technical drawings, performance data, material selection recommendations, and after-sales support for international clients. Whether you are upgrading an existing plant or designing a new emission control system, our team can help deliver a practical and efficient WESP solution.

For technical inquiries, product specifications, or quotation requests, please contact our sales and engineering team.