A filter may include: a first member having a first surface provided with a channel; and a second member set with a second surface thereof covering the channel. The first member may include a first passable portion that allows a fluid to pass between the first surface and a first space, which is defined beside a surface of the first member opposite to the first surface, through a first area of the channel. The second member may include a second passable portion that allows the fluid to pass between the second surface and a second space, which is defined beside a surface of the second member opposite to the second surface, through a second area of the channel distanced from the first area.

The invention relates to a filter arrangement for cleaning an air stream having at least three filter elements, wherein each filter element has a bellows made of pleated filter medium, wherein the filter elements are arranged in series and any two adjacent filter elements are connected to one another by means of a connecting tab. According to the invention, a fold run-out of all end folds of all bellows is oriented in a particular direction, the connecting tabs are of two different embodiments and the different embodiments of the connecting tabs are arranged alternatingly when viewed in a longitudinal direction of the filter arrangement. Not only is a simple installation of the filter elements in a filter holder thus facilitated but also a defined seating of the filter elements in the filter holder is ensured.

Multiple staged filters are provided herein. A filter may include a plurality of panels that each include a filtering front surface and a flat back surface, the filtering front surface having a first row of vertically extending protrusions spaced apart from one another to form vertical channels, a second row of vertically extending protrusions spaced apart from one another to form vertical channels, and one or more rows of filtering protrusions, where the one or more rows are vertically spaced apart from one another and extending between the first and second rows of vertically extending protrusions. Further, each row of filtering protrusions may include filtering protrusions that are spaced from one another to form filter channels having a size that is configured to receive and retain objects of a given size.

Multiple staged filters are provided herein. A filter may include a plurality of panels that each include a filtering front surface and a flat back surface, the filtering front surface having a first row of vertically extending protrusions spaced apart from one another to form vertical channels, a second row of vertically extending protrusions spaced apart from one another to form vertical channels, and one or more rows of filtering protrusions, where the one or more rows are vertically spaced apart from one another and extending between the first and second rows of vertically extending protrusions. Further, each row of filtering protrusions may include filtering protrusions that are spaced from one another to form filter channels having a size that is configured to receive and retain objects of a given size.

Multiple staged filters are provided herein. A filter may include a plurality of panels that each include a filtering front surface and a flat back surface, the filtering front surface having a first row of vertically extending protrusions spaced apart from one another to form vertical channels, a second row of vertically extending protrusions spaced apart from one another to form vertical channels, and one or more rows of filtering protrusions, where the one or more rows are vertically spaced apart from one another and extending between the first and second rows of vertically extending protrusions. Further, each row of filtering protrusions may include filtering protrusions that are spaced from one another to form filter channels having a size that is configured to receive and retain objects of a given size.

Multiple staged filters are provided herein. A filter may include a plurality of panels that each include a filtering front surface and a flat back surface, the filtering front surface having a first row of vertically extending protrusions spaced apart from one another to form vertical channels, a second row of vertically extending protrusions spaced apart from one another to form vertical channels, and one or more rows of filtering protrusions, where the one or more rows are vertically spaced apart from one another and extending between the first and second rows of vertically extending protrusions. Further, each row of filtering protrusions may include filtering protrusions that are spaced from one another to form filter channels having a size that is configured to receive and retain objects of a given size.

A three dimensional filter media for extended life filters includes: (a) a filter media base made of fabric selected from the group consisting of synthetic fabric, natural fabric and combinations thereof, the fabric being made of a plurality of threads, each of the plurality of threads being formed by a plurality of joined twisted thread filaments, the fabric being selected from the group consisting of woven fabric, knitted fabric, and combinations thereof, the fabric having a thickness of Z in the range of 0.020 to 0.075 inch, the fabric having a specified density; and, (b) a plurality of mechanical cilia connected to and protruding outwardly and away from the base, the cilia having a length that is at least 10 times Z, Z being the thickness of the base set forth above, and having a density that is no greater than 5% of the density of the base.

A three dimensional filter media for extended life filters includes: (a) a filter media base made of fabric selected from the group consisting of synthetic fabric, natural fabric and combinations thereof, the fabric being made of a plurality of threads, each of the plurality of threads being formed by a plurality of joined twisted thread filaments, the fabric being selected from the group consisting of woven fabric, knitted fabric, and combinations thereof, the fabric having a thickness of Z in the range of 0.020 to 0.075 inch, the fabric having a specified density; and, (b) a plurality of mechanical cilia connected to and protruding outwardly and away from the base, the cilia having a length that is at least 10 times Z, Z being the thickness of the base set forth above, and having a density that is no greater than 5% of the density of the base.

Filters (21) comprising a rolled expanded metal strip (13) are provided. The expanded metal strip (13) has an entrance zone (e.g., layer 1 and layer 2), a nozzle zone (e.g., layer 3), and, optionally, an exit zone (e.g., layers 4 and 5). The filter can also include an optional layer of woven wire mesh (e.g., layer 6). The filters have a thin wall (39) such that, in an embodiment, the ratio of the thickness (t) of the wall to the filter's outer diameter (OD) is less than or equal to 0.07, whereby the filter can weigh less and/or have a smaller envelope size than existing expanded metal filters. In an embodiment, the filter (21) can be used to filter and cool the gas stream produced by the rapid burning of the solid propellant (26) of an airbag inflator (157).

A method for producing an ash-free coal includes a step of mixing a coal with a solvent to prepare a slurry; a step of dissolving away a coal component soluble in the solvent, from the coal, by heating the slurry; a step of separating the solution containing the coal component dissolved therein from the slurry after the dissolution; and a step of subjecting the solution separated in the separation step to a vaporization and a separation of the solvent to obtain an ash-free coal. The separation step and the dissolution step are simultaneously performed.