This post highlights the key differences between the two most heavily used commercial filters- the bag filters and the Cartridge filters. Cartridge filters can be depth or surface-type filter. The depth-type filters eliminate the contaminants and particles by using the complete thickness of the medium, while in the surface-type filters, the particles or pollutants are blocked on the filter’s surface.
Surface filters are ideal if there is a need to filter sediments of same-sized particles. If all the particles are, for instance, of 5 microns, then a pleated 5-microns filter works the best since it has greater surface area than the other filters. Compared with the pleated surface filters, the depth-type filters hold a limited surface area; however, they have the benefit of depth.
It can be stated generally that is the filter surface size is increased, higher flows can be experienced, the filter will last longer with enhanced dirt control capacity. The cartridge filters are usually developed to be disposed of, implying that they must be replaced once they are clogged.
On the other hand, the bag filters are generally used for removing dust in a range of industrial applications. The flow can be from the outside to an inside of the filter, implying that the separation of the particles takes place on the external surface of the filter or the way around, based on an application. The particles are usually captured on the internal surface of a bag filter.
In general, bag filters are not designed for a replacement in case of clogging, but some bag filters usually those used for gaseous applications such as dust removal, can be cleaned, for instance by mechanical shaking or by the backwashing with compressed air.
Bag filters are typically the surface-type filters. As a general rule of thumb, for the concentration less than 5 mg/m3 a surface filter is ideal, while for concentrations less than 0.5 mg/m3 a depth-type bag filter is more suitable. Also, surface bag filters can be cleaned and back-washed more easily, while depth-type filters are usually disposed of when clogged.