A method of removing debris from a screen cover has a first mode of operation which includes: activating first and second fans to move first and second portions of air through screen cover and into a plenum, and moving the first and second portions of air from the plenum into a heat exchanger. A second mode of operation includes: deactivating the first fan for a first time period, activating the second fan for the first time period to move a third portion of air into the plenum, moving a first part of the third portion of air from the plenum into the heat exchanger during the first time period, and moving a second part of the third portion of air from the plenum through the screen cover during the first time period such that the second part of the third portion of air removes debris from the screen cover.

A method of removing debris from a screen cover has a first mode of operation which includes: activating first and second fans to move first and second portions of air through screen cover and into a plenum, and moving the first and second portions of air from the plenum into a heat exchanger. A second mode of operation includes: deactivating the first fan for a first time period, activating the second fan for the first time period to move a third portion of air into the plenum, moving a first part of the third portion of air from the plenum into the heat exchanger during the first time period, and moving a second part of the third portion of air from the plenum through the screen cover during the first time period such that the second part of the third portion of air removes debris from the screen cover.

A dust collector (1) is provided with a tank section (10) and a head section (20). The tank section (10) has a dust collection chamber (13) for containing dust. The head section (20) has a motor (23) and a dust collection fan (25). The dust collection chamber (13) has a cylindrical filter device (12) which, when air sucked in from the suction opening (11) flows through the filter device (12), separates dust from the air. A passage member (50) forms an air passage by which the outside air and a filter interior space (14) inside the filter device (12) are connected without having the filter device (12) therebetween. A cover body (60) closes the passage member (50) in an openable manner. The passage member (50) has first opening sections (53) facing the filter interior space (14) and located at different positions in the circumferential direction of the filter device (12).

Filter cartridges including tubular filter media having ovate cross-sections and filter systems using the ovate tubular filter cartridges are described herein. The inner perimeters of the ovate cross-sections of one or more of the filter cartridges may be asymmetric, i.e., the inner perimeters of the cross-sections of the tubular filter media in the filter cartridges may have no lines about which they are symmetric. The inner perimeters of the ovate cross-sections of the tubular filter media in one or more of the filter cartridges may have only one line of symmetry.

Filter cartridges including tubular filter media having ovate cross-sections and filter systems using the ovate tubular filter cartridges are described herein. The inner perimeters of the ovate cross-sections of one or more of the filter cartridges may be asymmetric, i.e., the inner perimeters of the cross-sections of the tubular filter media in the filter cartridges may have no lines about which they are symmetric. The inner perimeters of the ovate cross-sections of the tubular filter media in one or more of the filter cartridges may have only one line of symmetry.

Devices, systems and methods are disclosed which relate to using a wet foam elution method for removal of particles from a flat filter. Particles are captured from the atmosphere onto the flat filter. The flat filter is then placed into an extractor which passes a stream of wet foam through the flat filter. Expansion of the foam works to efficiently remove captured particles. The foam flows from the filter along with the captured particles into a sample container. Once in the sample container, the foam quickly breaks down leaving an analysis ready liquid sample.

Devices, systems and methods are disclosed which relate to using a wet foam elution method for removal of particles from a flat filter. Particles are captured from the atmosphere onto the flat filter. The flat filter is then placed into an extractor which passes a stream of wet foam through the flat filter. Expansion of the foam works to efficiently remove captured particles. The foam flows from the filter along with the captured particles into a sample container. Once in the sample container, the foam quickly breaks down leaving an analysis ready liquid sample.

A device is provided that provides an unbiased filtration effect and an effect of removing captured substances through backwashing by causing a fluid to uniformly pass through a filter element over the entire length in an axial direction at the time of backwashing so as to efficiently rotate a captured-substance removal tool in a filtration unit 1 which includes the captured-substance removal tool 20 axially supported inside the tubular filter element 2 to be rotatable.

A device is provided that provides an unbiased filtration effect and an effect of removing captured substances through backwashing by causing a fluid to uniformly pass through a filter element over the entire length in an axial direction at the time of backwashing so as to efficiently rotate a captured-substance removal tool in a filtration unit 1 which includes the captured-substance removal tool 20 axially supported inside the tubular filter element 2 to be rotatable.

An air filtration system for an operator environment of an agricultural vehicle including at least one external inlet, a first filtration device having a coarser level of filtration located between the external inlet and an HVAC system, a second filtration device having a second finer level of filtration and an associated blower located between the external inlet and the HVAC system where the air filtration system selectively connects either the first filtration device to the HVAC system blower or the second filtration device and its associated blower to the HVAC system blower and a bypass permanently connects the HVAC system blower and the second filtration device.