Dust collection technology removes particulate pollutants generated in industrial processes. Electrostatic precipitators capture dust using electrons and are categorized into dry and wet methods. Recently, due to environmental regulations, the importance of wet methods has grown significantly.
Dust collection technology is a critical method for removing particulate pollutants generated during industrial processes. This technology is essential for environmental protection and worker health. As industry advances, air pollution problems are becoming more severe, making responses increasingly important. When pollutants are released into the atmosphere, they can have harmful effects on human health and, in the long term, contribute to climate change. Therefore, the development and application of efficient dust collection technology has become a fundamental requirement for modern industry.
Electrostatic precipitators, in particular, are highly effective. They work by artificially generating electrons that adsorb onto dust or harmful substances, which are then collected on the collection plates. Electrostatic precipitators utilize the principle of electrically charging pollutant particles to adsorb them onto collection plates. This method is more efficient than physically removing pollutants and offers the advantage of effectively capturing even fine particles. Consequently, electrostatic precipitation is widely used across various industrial sectors.
Additionally, electrostatic precipitators are categorized as dry or wet types based on their filter cleaning method. The vast majority of precipitators installed and operated in domestic power plants are dry electrostatic precipitators. Dry electrostatic precipitators are favored by many power plants due to their ease of maintenance and lower operating costs. However, with the recent strengthening of environmental regulations, dry electrostatic precipitators alone are insufficient for controlling pollutants like ultrafine dust. Ultrafine dust can be directly inhaled into the human respiratory system, causing serious health problems, making its effective removal crucial. Consequently, the recent trend is to use wet electrostatic precipitators as the final pollution control equipment.
While the main body of a wet electrostatic precipitator can take various forms, a cylindrical precipitator can be used as an example. First, the lower part of the main body connects to a passage where contaminated gas enters, while the upper part connects to a passage that discharges air purified by filtering out contaminants. Inside the cylinder, at its center, is a discharge rod with a pointed discharge needle. Collector plates are installed on the inner wall of the cylinder to capture the contaminated particles. The discharge rod and the collection plates are connected to the (-) and (+) poles, respectively, by a high-voltage generator. Additionally, a device supplying cleaning water to the collection plates is installed to remove the captured contaminants.
The process of removing contaminants in a wet electrostatic precipitator is as follows. First, when a high voltage is continuously applied to the discharge rod via the high-voltage generator, corona discharge occurs at the tip of the discharge rod. Corona discharge refers to the phenomenon where the insulating state of a gas, which unlike metal does not conduct electricity, is broken down by a high voltage. When a high voltage is continuously applied to a sharp-tipped object, such as a needle, a negative charge accumulates at the tip, causing the electrostatic force to increase sharply. This causes gas molecules in the vicinity to lose electrons from their nuclei, breaking down the gas’s insulating state. Subsequently, electrons generated by the corona discharge migrate toward the (+) pole’s collection plate due to polarity. These electrons pass through the space between the discharge rod and the collection plate, colliding with minute airborne contaminants. When electrons are adsorbed onto the surface of these contaminants through such collisions, the contaminants acquire a negative charge; this is called the contamination’s electrification. The charged contaminants, or charged particles, are then drawn toward the collector plates by the electric field formed between the (-) electrode discharge rod and the (+) electrode collector plates, where they are captured. Finally, the contaminants are washed off by the cleaning water and removed.
In this way, electrostatic precipitators play a vital role in protecting the atmospheric environment by effectively removing pollutants. However, to meet continuously evolving environmental regulations, it is necessary to introduce new precipitation technologies alongside technological advancements. These efforts will ultimately contribute to making our environment cleaner and healthier. For example, various studies are currently underway to further enhance the efficiency of electrostatic precipitators. Examples include maximizing the surface area of collection plates using nanotechnology or improving pollutant capture efficiency with new materials. Additionally, technologies are being developed to optimize airflow within the precipitator, enabling pollutants to adhere more effectively to the collection plates. These technological innovations will further enhance the performance of electrostatic precipitators, contributing to the creation of a better atmospheric environment.
In conclusion, electrostatic precipitator technology plays a vital role in effectively removing pollutants generated in industrial settings. The harmonious use of dry and wet electrostatic precipitators provides flexibility to address diverse pollutants. Continuous technological development and adaptation to environmental regulations are essential for creating a cleaner atmospheric environment. We look forward to the continuation of these efforts.
