A filter cartridge, also called a filter element, is a replaceable component installed inside a dust collector. It captures airborne particulate matter and separates dust from the airflow. Industrial air-intake filter cartridges are also used as prefilters for gas turbines, blowers and air-compressor stations.

Filter cartridges provide a large filtration area within a compact volume because of their pleated construction. Whether a filter cartridge or a filter bag is more suitable depends on the dust characteristics, concentration, temperature, moisture content and operating conditions. For high dust concentrations, a cyclone or another pre-separation device may be required before the cartridge dust collector.

Replacing conventional filter bags with long pleated filter cartridges can increase the available filtration area, reduce the air-to-cloth ratio and save equipment space. The final emission performance depends on the filter media, dust characteristics, equipment design and operating conditions.

Industrial filter cartridges are commonly cleaned using compressed-air pulse-jet cleaning. Compressed air, typically at 4 bar or higher, is released through a pulse valve into the cartridge. The resulting pressure wave causes the filter media to flex and helps dislodge accumulated dust from its surface, reducing differential pressure and restoring airflow.

Common filter cartridge sizes include Ø350 × 660 mm, Ø324 × 660 mm and Ø324 × 1,000 mm. We can also manufacture filter cartridges in other diameters, lengths and connection designs for replacing conventional filter bags. Depending on the filter media and production requirements, customized cartridges up to approximately 3 meters long are available.

Available designs include cylindrical, conical and long bag-replacement filter cartridges. Replacement cartridges can also be manufactured according to the customer’s drawings, dimensions or physical samples.

Available installation methods include horizontal insertion, inclined insertion, chuck-and-rod mounting, threaded-rod mounting, three-lug mounting, top installation, bottom installation and side installation. The connection design can be customized to match the customer’s dust collector.

Common filter cartridge media include cellulose filter paper and polyester (PET) spunbond non-woven media. High-temperature pleatable media, including fiberglass, PPS, P84 and Nomex, are also available for suitable operating conditions.

A cellulose filter cartridge uses cellulose-based filter paper as its primary filtration medium. It is generally suitable for relatively low dust concentrations and dry operating conditions. Cellulose media can accommodate more pleats than polyester media within a cartridge of the same dimensions. For example, a Ø350 × 660 mm cartridge typically provides a filtration area of approximately 20–23.4 m².

Depending on the application, cellulose filter media can be supplied with nanofiber surface treatment, flame-retardant treatment or antistatic properties. The appropriate treatment should be selected according to the dust characteristics and operating conditions.

A polyester filter cartridge uses pleated polyester (PET) spunbond non-woven media. It is generally stronger and more suitable for relatively high dust concentrations than conventional cellulose media. Because polyester media is thicker, it normally has fewer pleats within a cartridge of the same dimensions. A Ø350 × 660 mm polyester cartridge typically provides approximately 9–10 m² of filtration area.

Polyester filter media can be supplied with PTFE membrane lamination, flame-retardant treatment, antistatic treatment, oil- and water-repellent treatment or other functional surface treatments, depending on the application.

Filter cartridge efficiency depends on the base media, fiber structure, surface treatment and membrane technology. A fine surface layer or microporous PTFE membrane can improve particle capture and surface dust release, although it may also increase the initial resistance.

Typical cellulose filter media weighs approximately 135 g/m², while polyester spunbond media commonly weighs approximately 240–260 g/m². High-temperature media such as PPS, P84 and Nomex may weigh approximately 350–360 g/m². Actual efficiency and media weight depend on the selected material and specification.

Nanofiber coating is commonly applied to cellulose filter media to create a fine surface filtration layer. Resin impregnation is often used to improve the stiffness, strength and moisture resistance of filter media. PTFE or ePTFE membrane lamination bonds a microporous membrane to the surface of the base media, providing high-efficiency surface filtration and improved dust release. The correct treatment depends on the dust and operating conditions.

Not necessarily. A larger filtration area can reduce the air-to-media ratio, but adding too many pleats reduces the spacing between them. Dust may become trapped between closely spaced pleats, making pulse cleaning less effective and shortening cartridge service life. Filtration area, pleat spacing and cleaning performance must therefore be properly balanced.

The appropriate filtration velocity depends on dust concentration, particle size, bulk density, moisture, temperature and filter media. Lower filtration velocity generally reduces pressure drop and improves service life, but it also requires more filter area and a larger dust collector.

As a general reference, cellulose filter cartridges are often selected at approximately 0.5–0.7 m/min, while polyester filter cartridges are commonly selected at no more than approximately 1.2 m/min. The final value should be determined according to the actual application.