The present disclosure relates to air filters. More particularly, it relates to air filters including pleated filter media that can be uniformly expanded and contracted. In some embodiments, the air filters are adjustably sized air filter systems. In some embodiments, the air filters can be used in a window opening.

A filtration filter comprises a porous film including a central film portion having a plurality of through holes and an outer edge portion adjacent to the central film portion. The porous film portion lies in a flat plane in the absence of a force being applied to the central portion of the central film portion. A frame holds the outer edge portion of the porous film in such a manner that when a force is applied to the central film portion in a first direction, the central film portion moves in the first direction relative to the flat plane and the outer edge portion moves in a second direction, opposite to the first direction, relative to the flat plane. In this way stresses applied to the porous film during a filtering operation are reduced.

A filtration system comprising a housing defining a central compartment, an outlet and a housing sealing surface having a first non-planar surface. A cover is removably coupled to the housing. The cover defines an inlet and comprises a cover sealing surface having a second non-planar surface. The filtration system also includes a filter element comprising a filter media and a seal member. The filter element is removably received in the central compartment. The seal member comprising a complimentary non-planar sealing surface that matches the first non-planar surface and the second non-planar surface such that the seal member axially pinched between the housing and the cover by the housing sealing surface and the cover sealing surface to form a first seal between the seal member and the housing and a second seal between the seal member and the cover.

Disclosed is an air filtration module for seed planters. The filtration module includes a filter cartridge with a filter media disposed therein. The cartridge is sized and shaped to fit into the stock seed hopper. The filter media is configured to filter out and contain particles of seed coating materials that contain neonicotinoids and/or other airborne contaminants. The filter cartridge can replace the porous seed container wall through which compressed air is discharged out the seed hopper air discharge vent.

A trap bowl is provided to accumulate liquid droplets from a filter, as a liquid content. The trap bowl includes a transparent vertical prism. The transparent vertical prism includes a face that forms a vertical transparent surface facing against a content of the section. The face can provide a first angle of total reflection when content of the section is a type of gas, and a second angle of total reflection when the content of the section is the liquid content. A light source may emit a light beam incident on the face at an angle of incidence. The angle of incidence results in reflection of the light beam, striking the light receiver, when the face has the first angle of total reflection, and results in refraction of the light beam, missing the light receiver, when the face has the second angle of total reflection.

This gas purification filter unit (10) is provided with: a first elimination unit (11) that eliminates gas component impurities among the impurities contained in ozone generated from an ozone generating device; and a second elimination unit (12) that is disposed at a later stage than the first elimination unit and that further eliminates solid particulate impurities from among the impurities from which the gas component has been eliminated. Ozone containing impurities are caused to flow in from the inflow end (10a) of such a gas purification filter unit (10) and is passed through the first elimination unit (11) and second elimination unit (12), and thus ozone from which impurities have been eliminated is discharged from an outflow end (10b).

A filter element for filtering impurities from air, comprises one or more filter packages whereby each filter package is made of a single-layered or multilayered filter medium and is connected to an inflow opening in an inlet piece. The inlet piece and the inflow opening of the inlet piece have an aerodynamic design, and that the filter package is essentially skittle-shaped, such that one end of which is open and fastened to the inflow opening and the other end of which is closed by a filter medium from which the filter package is also made.

An air cleaning device is provided. The air cleaning device includes: a main body; a filter configured to be disposed in the main body to purify air; and an image transmitter configured to show a state of the filter to an outside of the main body.

A brake disc arrangement has a brake disc and a brake caliper arranged at the brake disc. A brake caliper holder is provided. One or more bearing bolts hold the brake caliper at the brake caliper holder. A brake dust particle filter is provided with a filter housing. The filter housing of the brake dust particle filter is fixedly connected by the one or more bearing bolts to the brake caliper or to the brake caliper holder.

A multi-piece air filter housing, air filter assembly, and method for assembling an air filter for use with a heating, ventilation, and air conditioning (HVAC) systems or stand alone air circulation devices. In one example at least a first sidewall section and a second sidewall section include sidewall connectors allowing the first and second sidewall sections to be connected defining an interior cavity for receipt and support of air filter media. In one example, the air filter housing includes four modular sidewall sections that are connected together to form the air filter housing. A housing connector is used to secure the air filter housing and filter media circumferentially around a forced air passage opening to direct airflow through the air filter housing and filter media. In one example, the air filter assembly is useful for suspending ceiling HVAC vents.