In the dust collection business, bag filter vs. cartridge filter has drawn much attention recently. Each is an application used for the treatment of dust in industrial processes. To a certain extent, the use of these filters is at the center of an ongoing debate. One that’s central question pivots on which application is better: bag filters or cartridge filters?
The answer to that question merits attention, if only because entire industries are behind each. However, there are differences between the two that merit attention as well. More practical reasons relating to why one type of filter would be favored over another. For that answer, “The devil is in the details,” and worth a closer look.
Bag Filters
Bag filters are fabric filters used in baghouse dust collectors, which are industrial-scale fabric filter systems used in manufacturing and other industrial operations to remove dust, gases, and solid particulates from the workplace and from being released into the atmosphere. Baghouse systems have long been the industry standard in industrial dust collection. In fact, for most in the industry, the word “baghouses” are synonymous with “dust collectors,” and the two are often used interchangeably.
Cartridge Filters
On the other hand, cartridge filters are fabric filters used in cartridge dust collector systems, which are also employed in industrial and manufacturing environments to remove harmful dust, particulates, and gases from the airstream. Cartridge dust collectors have grown in popularity in recent years. They are well-regarded for their efficiency and are practical applications for use in metalworking, plasma cutting, blasting, welding, powder coating, and woodworking, or the general ventilation of large spaces, and more.
What’s the Difference Between a Bag Filter and vs Cartridge Filter?
Both bag and cartridge filters can be made from different materials or in different sizes or shapes, and the specific weight of the fabric used can also differ. However, typically, the fabric materials are polymeric, and either may be rendered with surface treatments to enhance filtration performances for specific purposes.
That said, their design is the primary difference of note between the two filters. Cartridge filters are pleated, and bag filters are not. Cartridge filters are housed in either a metal mesh, known as expanded metal, which is attached to the outside or inside of the cartridge (or both), or instead, fabric bands can be used to retain the shape of the cartridge. Bag filters are arranged in rows and mounted vertically over a sheet metal cage housing.
Pleated cartridge filters can be adapted to fit baghouse dust collection systems, whereas bag filters cannot and would not be adapted for use in cartridge dust collection systems. That baghouse systems can also utilize pleated cartridge filters to remove particulate matter from the air is an important indicator that favors cartridge filters—to an extent.
Pleated filters have, by design, an increased surface area. As a result, the increased filter surface area allows for lower air-to-cloth ratios in the same space as a bag filter, which, in turn, allows for more particulates to be captured from the airstream. Pleated layers of deeply woven fabric pockets also allow for higher dust retention rates. In sum, pleated filters are known for their high efficiency, long service life, and low maintenance.
However, pleated baghouse filters have a slightly higher pressure drop than traditional fabric bags because of the larger media surface area and require more cloth. Though the service life is more extended and filter changeouts are less frequent, the initial and ongoing costs of the cartridges are higher than traditional fabric bags. Installation time of pleated filters takes longer than conventional bag filters, too, and can require additional effort to replace, which may result in extended downtime.
Which Filter Is Better for Your Dust Collector System?
In the ongoing bag filter vs. cartridge filter debate, “Which filter is better?” can only be answered by asking, “Which filter is better for your system?” Your application’s needs will determine which filter type best suits your production and work environment. Cartridge dust collectors are ideal for light-loading applications where the dust is dry and free-flowing; suitable for specific configurations and applications and perfect for placement in smaller spaces with the same airflow as a more extensive baghouse system.
Baghouse collectors may be “old school” regarding dust collection systems, but they are just as relevant today as they always have been. They are still engineered to collect, capture, and separate dust and particulates from the air with up to 99.9% efficiency. They are most effective in capturing larger particulate matter and for extreme loading applications.
Bag filters do offer a long service life. They can handle more demanding and heavier dust loads, abrasive or sticky materials, high-temperature applications, and particles contaminated with solvents or moisture. As cartridge filters continue to grow in popularity, and more companies move to take advantage of their efficiency, low maintenance, smaller size, and increased filter surface area, it is possible to upgrade existing baghouse systems. As pleated bags can be incorporated into most existing baghouse systems, companies do not need to upgrade to a new system or reinvest in an extensive redesign of the old one.
To learn more about bag and cartridge filters and which application suits your company’s dust collection needs, please contact us at CPE Filters today!