Electrostatic precipitator

Inside of the electrostatic precipitator

Collection electrode of electrostatic precipitator in waste incineration plant in Gdansk

InsulatorWESPHousingRemoved

Electrostatic precipitator

Resistivity Values of Representative Dusts and Fumes From Industrial Plants

Electrostatic Precipitator (ESP) is a filtration device that removes fine particles, like dust and smoke, from a flowing gas using the force of an induced electrostatic charge minimally impeding the flow of gases through the unit. In simple terms, it is a device that uses electricity to capture particles in the air or gas stream.

History

The concept of electrostatic precipitation has been known since the 18th century. The first practical ESP was developed by Dr. Frederick Cottrell in 1907. He was a chemistry professor at the University of California, Berkeley, and his invention was initially aimed at controlling the acidic emissions from smelters.

Principle of Operation

An electrostatic precipitator works by forcing dirty flue gas (the gas escaping from a furnace) past two electrodes. These electrodes are known as the charge electrode and the collecting electrode. The charge electrode emits a high-voltage electric charge to the particles in the gas. These charged particles are then attracted to the collecting electrode, where they accumulate until they are removed.

Key Components

• Charging Electrode: Also known as discharge electrodes, these are responsible for ionizing the air and charging the particles in the gas stream.
• Collecting Electrode: These are large plates that attract and collect the charged particles.
• Rapper: A mechanical system used to remove the collected particles from the collecting electrodes.
• Hopper: The area where the collected particles are stored before removal.

Types of Electrostatic Precipitators

Electrostatic precipitators can be categorized into two main types based on their operation: dry and wet.

• Dry Electrostatic Precipitators: These are used to collect dry particles like dust and ash. They are widely used in power plants, iron and steel mills, and cement plants.
• Wet Electrostatic Precipitators: These are used to remove wet particles like oil, tar, and wet dust. They are often used in paper mills and in the production of acid.

Applications

Electrostatic precipitators are used in a variety of industries to reduce air pollution. Their applications include:

• Power plants
• Cement industry
• Steel mills
• Paper mills
• Chemical industry

Advantages and Disadvantages

Advantages

• High efficiency in removing particles
• Ability to handle large volumes of gas
• Low operating costs
• Can remove particles of varying sizes

Disadvantages

• High initial cost
• Requires significant space
• Performance can be affected by the electrical properties of the particles
• Maintenance and operation require specialized knowledge

Environmental Impact

Electrostatic precipitators play a crucial role in reducing air pollution. By removing particulate matter from emissions, ESPs help in improving air quality and protecting human health and the environment. However, the disposal of collected particles can pose environmental challenges.

Future Developments

Advancements in ESP technology focus on improving efficiency, reducing energy consumption, and minimizing the impact of collected particle disposal. Innovations include the development of compact ESPs, improvements in electrode materials, and the integration of ESPs with other pollution control technologies.