Introduction To Filter Bags

Basic Introduction  

A filter bag is a highly efficient, replaceable bag-type filter element. Its primary function is to separate solid particulate impurities from liquids or gases through physical mechanisms such as interception and adsorption. Typically constructed from flexible filter media—such as polyester, polypropylene, nylon, or PTFE—the filter bag is designed in a pouch-like structure. It is installed within a dedicated support basket or frame, which is housed inside the filter casing. As the fluid passes through the bag filter, contaminants are retained either within the filter medium or on its surface, allowing only the purified fluid to pass through. This operational mechanism aligns with the principles of either depth filtration or surface filtration, and is extensively utilized in industrial purification processes.

Filter bags are primarily utilized in applications that require the efficient removal of particulate pollutants. These include industrial liquid purification, such as filtration of medicinal liquids, solvents, and acidic or alkaline solutions within the chemical industry. For water treatment, filter bags are employed in the pretreatment of industrial wastewater and the protection of circulating water systems. Additionally, they are used to control particulate matter in lubricating oils and fuel oils in the oil industry.

As a core application, filter bags play a crucial role in industrial gas dust removal. In the power generation sector, they are used for flue gas filtration in coal-fired power plants, enabling compliance with ultra-low emission standards.  They are also applied in high-temperature flue gas treatment during waste incineration, as well as in the collection of welding fumes and pharmaceutical dust.