The present invention relates to an enhanced exclusion filter having a cylindrical stack of substantially identical annular disks and a central rotating element. Each annular disk engages the rotating element by at least one strut which extends inward from the inner perimeter of the annular disk toward the central axis of the cylindrical stack. Protuberances extend from the annular disks and engage depressions in adjacent annular disks to maintain the spacing between adjacent annular disks. Dimples extending through the annular disks may be utilized to form a depression on one surface of an annular disk and a protuberance on the opposite surface of the annular disk. The annular disks are angularly offset by a fixed amount from the adjacent annular disks so that rough vane surfaces are formed by the struts of the annular disks. Preferably a pattern of substantially identical angular offsets is used. In the alternative, a pattern of angular offsets may be used in which series of small angular offsets are separated by large angular offsets in a direction opposite from the small angular offsets. Preferably, the design of the struts is modified so that the trailing and leading edges of the struts extend toward adjacent struts, forming more continuous vane surfaces. The present invention also relates to the use of exclusion filters as a means of providing a flow of fluid through electronics enclosures. The present invention also relates to the use of redundant pressurized enclosures comprising an enclosure casing, two exclusion filters, and two pressurizing means. The enclosure casing has a major orifice through which fluid enters the enclosure casing and a minor orifice through which fluid exits the enclosure casing. The pressurizing means discharge filtered and pressurized fluid in two discharge areas within the enclosure casings which are substantially opposite from one another.
An edge filter assembly is disclosed. The edge filter assembly may include a housing having an inlet and an outlet. The edge filter assembly may further include a filter element disposed within the housing including first and second filter plates and first and second spacers disposed between the first and second filter plates. The spacers and filter plates may be configured and arranged to form a flow channel extending generally radially within the housing and defined between the first and second filter plates and the first and second spacers. The flow channel may have an inner flow gate and an outer flow gate. The inner flow gate may be disposed radially inward of the outer flow gate and may have a different cross-sectional configuration than the outer flow gate. The first filter plate may have an axial projection extending therefrom generally aligned with a fluid path within the housing.
