An air filter is a device that separates dust from flue gas and is called an air filter or dust removal device. Its performance is expressed by the amount of gas that can be handled, the resistance loss when the gas passes through the air filter, and the filtration efficiency. At the same time, the price, operation and maintenance costs, service life, and ease of operation and management of air filters are also important factors in considering their performance. Air filters are commonly used in boilers and industrial production. Dust-collecting hoods are installed at places where dust is emitted, dust-laden gas is transported to the dust-removing device through the pipeline gas path, gas-solid separation is performed, dust is collected in the dust-removing device, and clean gas is introduced into the main pipe or The complete set of equipment directly discharged into the atmosphere is the air filter system, and the air filter is an important part of the system. From the perspective of ventilated air filters, dust is all small solid particles that can exist in air for a long time in a floating state. It is a dispersed system called aerosol, in which air is a dispersion medium and solid particles are dispersed phases. An air filter is a device that separates this small solid particle from the aerosol. According to the principle of the role of dust collector can be divided into the following categories:
1. Dry mechanical dust collector mainly refers to the dust removal equipment designed for application of inertial dust and gravity, such as sedimentation chambers, inert dust collectors, cyclone dust collectors, and other high concentration dust collectors, mainly for high-concentration coarse particle diameter dust The separation or concentration used.
2. Wet dust collector relies on hydraulic force to separate and collect dust particles, such as spray towers, scrubbers, impact dust collectors, venturis, etc., in the process of processing the production of high concentration, high air volume Dust-laden gas is used more often. For coarser, the separation efficiency of hydrophilic dust is higher than that of dry mechanical dust collectors.
3, particle layer dust collector with different particle size of the granular material layer as a filter material to filter the dust contained in the air dissolved equipment. It is mainly used in dust removal points in the production process of building materials, metallurgy, etc. It is often used to filter dusty gas with high concentration, coarse particles and high temperature.
4. Bag type dust collector, which is a dust removal device with fiber woven or filled layer as filter medium, and its use, form, size and efficiency of dust removal have a wide range, mainly used in the capture The place of fine dust is applied on the exhaust dust removal system and applied on the air intake system. In recent years, due to the continuous development of new filter media, the development of fiber filtration technology has also accelerated. With the continuous emergence of new products, the application fields have also expanded.
5. Electrostatic precipitator The precipitator introduces the dust-laden airflow into the electrostatic field. Under the action of the high-voltage electric field, the gas is ionized to generate electrons and positive ions. They move to positive and negative poles, respectively, when the dust particles flow through the operating electric field. Negative charges are removed at a certain rate toward the sedimentation plate opposite to their negative charge sign, where they settle down and thus leave the open air stream and are collected in an electrostatic precipitator. The dust collector has high dust removal efficiency, low resistance, and convenient maintenance and management. It has the same effect as the bag filter in capturing fine dust particles.