Development Of Dust Removal Industry

The development of dust removal technology is closely related to the industrialization process in China. Dust removal technology generally includes mechanical dust removal, wet dust removal, Electrostatic precipitator and bag type dust removal.
Mechanical dust removal utilizes the gravitational settling, inertia, or centrifugal force of dust to separate it. Its dust removal efficiency is generally below 90%, with low dust removal efficiency, low resistance, and energy conservation.
Wet dust removal utilizes the principle of gas-liquid contact washing to separate dust from dusty gases into liquids to remove dust from the gas. Its dust removal efficiency is slightly higher than that of mechanical dust removal, but it can easily cause secondary pollution of the washing liquid.
Electrostatic precipitator is to charge the dust particles by passing the dusty gas through a strong electric field. When it passes through the dust removal electrode, the particles with positive/negative charges are respectively absorbed by the negative/positive electrode plate, so as to remove the dust in the gas. The Electrostatic precipitator has a high dedusting efficiency, but its dedusting efficiency is greatly affected by the dust specific resistance, which is easy to lead to unstable dedusting efficiency. Since the 1990s, Electrostatic precipitator has been widely used in the treatment of smoke and dust pollution with high temperature, large flue gas volume and complex working conditions, such as thermal power generation and cement kiln. Bag filter is a type of dust collector that uses fiber filter materials to capture solid particles in dusty gases, forming a filter cake. Through the filter cake, fine dust particles are further filtered to achieve efficient dust removal. Bag dust removal technology can stably achieve high dust removal efficiency, with dust emissions reaching within 5mg/m3, and the dust removal efficiency is not affected by dust characteristics such as dust specific resistance. Generally speaking, dust with a particle size less than 10 microns (i.e. inhalable particulate matter) has a significant impact on human health, and bag filters have high separation efficiency for inhalable particulate matter. The application range of bag type dust collectors in the treatment of ambient temperature flue gas (<120 ℃) pollution is gradually expanding. With the further development of high-temperature resistant filter materials and pulse cleaning technology, bag type dust collectors have been increasingly widely used in the field of treating high temperature and high concentration flue gas due to their excellent dust removal performance.
With the acceleration of industrialization and urbanization, air pollution in China has become increasingly serious, and the emission standards of air pollutants have become increasingly stringent. Electrostatic precipitator and bag filters with high dust removal efficiency have been widely used. At present, Electrostatic precipitator and bag filter are the mainstream dedusting technologies in China.
Compared with Electrostatic precipitator, bag filter has greater advantages in energy saving and emission reduction. Under the situation of increasingly stringent national emission standards, the use of bag filter will become the main choice to control dust pollution.