Disclosed is an air filter using high density filter paper. The filter paper may include a thermally bonded non-woven fabric filter paper 10 having air permeability to filter foreign materials of passed polluted air and change the polluted air to fresh air. The non-woven fabric filter paper includes wrinkled portions 10-1 and 10-N that are folded at a predetermined interval. A thickness of the wrinkle portions 10-1 and 10-N are provided with dense layers 15 and 17 comprising a first polyethylene terephthalate (PET) fiber 20-2 that can shrink by heat and a second polyethylene terephthalate (PET) fiber 20-1 that deforms upon by heat treatment.

A foldable filter frame including a filter media and a rectangular support frame surrounding and secured to the filter media, having opposed side frame elements having a hingable joint formed near the midpoint that allows the support frame and a dirt-capturing surface of the filter media to fold along lateral line from a planar, extended position to a folded position. The joint includes a fold line in a dirtied-side attaching panel, and a cut formed through a base and a clean-side attaching panel, of the side frame elements, and a means for biasing the joint to the planar, extended position. The biasing means is a strip of elastic member, stapled to an inside surface of the clean-side attaching panel in a relaxed state, across the cut formed through the clean-side attaching panel. The frame can have Velcro-type fasteners in the corners to secure the frame in the folded position.

The invention relates to an exhaust gas purification system applied to an internal combustion engine. The engine has a turbocharger including a turbine wheel and a housing for housing the turbine wheel. The housing defines a turbine outlet passage communicating with an exhaust gas discharging part of the turbine wheel. The engine further has an exhaust passage part communicating with an exhaust gas outlet of the turbine outlet passage. The system comprises an exhaust gas purification apparatus disposed in the exhaust passage part at a position adjacent to the exhaust gas outlet of the turbine outlet passage. Further, the apparatus includes an exhaust gas purification member. The member is provided such that its density in a peripheral part of the exhaust passage part is larger than that in a central part of the exhaust passage part and a flow passage resistance per unit volume of the member at an area of the central part of the exhaust passage part is smaller than that at an area of the peripheral part of the exhaust passage part.

Filtration media, media packs, and filtration elements are described, including fluted filtration media having offset flutes arranged to intermittently contact flutes on adjacent media, including angled and curved flutes. Pleated filtration media with alternating sealed pleat edges are also disclosed, including fluted media with alternating sealed flutes. A media pack can have a first sheet of media and a second sheet of media. The first sheet of media can have a first plurality flutes defining first flute valleys extending between a first face and a second face of the media pack. The second sheet of media can have a second plurality of flutes defining second flute peaks extending between the first face and the second face of the media pack. The first plurality of flutes can be non-parallel to the second plurality of flutes, and each first flute valley contacts one second flute peak at a discrete contact point.

A forcing and fixing structure for the filter cylinders of a filter cylinder dust collector includes a housing provided therein with a division plate. Plural twinned setting racks are disposed under the division plate, and plural twinned forcing rods are respectively set on the setting racks, and the forcing rods are respectively and vertically connected with a rotary handle. Further, plural assembling-and-disassembling plates are respectively mounted on each pair of the forcing rods for plurality filter cylinders to be fitted thereon. When the rotary handles are turned to actuate the forcing rods to rotate and drive the assembling-and-disassembling plate to move upward, the filter cylinders can be forced to tight fit with the division plate, thus facilitating assembly and disassembly of filter cylinders, attaining good airtight effect and elevating efficacy of air purification and quality of use of the filter cylinder type dust collector.

A filter element has a mat-type or sheet-type filter web (3) forming by its outside (5) at least in part a filter jacket (7). Along the outside (5) of the filter jacket (7), a surface configuration or modification takes place with structures (11) being delimited from the remaining surface (9) of the filter web (3), being joined to the filter jacket (7) and being of presettable contour and/or thickness. The structures (11) are generated by spray-fiber application and shaping, in such a manner that in time sequence, first the structures (11) and then the filter jacket (7), or in reverse order in time sequence, first the filter jacket (7) and then the structures (11), or that simultaneously both the filter jacket (7) and the structures (11) are formed in negative or positive shape on the filter jacket (7). The production of the filter element and a shaping device used in this production process are disclosed.

An air filter element fits upon an air cleaner housing with a bar element that is received into the outlet face of the air filter element. The air filter element has a receiver extending into the outlet face to accommodate the bar. In the case of a deep pleated pack for the filter element, a widened split may be provided to accommodate the bar. A protective member that can be provided as part of a basket may project into the outlet face to protect the air filter element pack at the receiver.

Filter media comprising surface-treated fiber webs having one or more advantageous physical properties are generally described. Certain improvements in the surface-treated fiber webs described herein may be realized in filter media comprising adsorbent particles. The improvements herein are, in some embodiments, related to favorable distributions of cavities in surface-treated fiber webs, such as those used in backers of the filter media.

A foldable filter frame including a filter media and a rectangular support frame surrounding and secured to the filter media, having opposed side frame elements having a hingable joint formed near the midpoint that allows the support frame and a dirt-capturing surface of the filter media to fold along lateral line from a planar, extended position to a folded position. The joint includes a fold line in a dirtied-side attaching panel, and a cut formed through a base and a clean-side attaching panel, of the side frame elements, and a means for biasing the joint to the planar, extended position. The biasing means is a strip of elastic member, stapled to an inside surface of the clean-side attaching panel in a relaxed state, across the cut formed through the clean-side attaching panel. The frame can have Velcro-type fasteners in the corners to secure the frame in the folded position.

Apparatus for separating ash particles from a flue gas. The apparatus includes a screen that has a plurality of semi-elliptical cylinder surfaces. The semi-elliptical cylinder surfaces having holes through which said flue gas flows and through which the ash particles will not pass. The screen has a single layer for performing the separation in a manner such that the ash particles fall away from the screen and collect outside of the screen. A method of reducing velocity of a flue gas passing through screening apparatus for separating flue gas from ash particles. The method includes replacing a first screen of the screening apparatus with a second screen that has a plurality of semi-elliptical cylinder surfaces.