Patent ID: 7323106

Claim:
A filter comprising a plurality of pleated filter elements pleated along axially extending bend lines to form axially extending channels extending axially along an axial direction from an upstream end to a downstream end, each channel having a channel height extending transversely along a transverse direction perpendicular to said axial direction, each channel having a channel width extending laterally along a lateral direction perpendicular to said transverse direction and perpendicular to said axial direction, said channels being alternately sealed at said upstream and downstream ends to provide a first set of flow channels open at their upstream ends and closed at their downstream ends, and a second set of flow channels closed at their upstream ends and open at their downstream ends, a first and a second of said filter elements having a transverse gap therebetween at one of said upstream and downstream ends, and being sealed to each other at the other of said upstream and downstream ends, said gap providing additional fluid flow axially therethrough, the channel height of said first filter element being different than the channel height of said second filter element, wherein said first and second filter elements are angled with respect to each other as they extend axially from upstream to downstream to provide said transverse gap therebetween of changing transverse width, and wherein said gap tapers from a first transverse width at said one of said upstream and downstream ends to a second transverse width at the other of said upstream and downstream ends, one of said first and second transverse widths being greater than the other of said first and second transverse widths.