Multi-panel fluid filter with equalized contaminant passages

A filter for filtering fluid flowing along an axial flow direction comprising a plurality of panels of pleated filter elements, each filter element having a plurality of pleats defined by wall segments extending along a transverse direction between first and second sets of pleat tips at first and second sets of axially extending bend lines, said transverse direction being perpendicular to said axial direction, each of said panels extending along a lateral direction perpendicular to said axial direction and perpendicular to said transverse direction, said wall segments extending axially between upstream and downstream ends, said wall segments defining axial flow channels therebetween, said upstream ends of said wall segments being alternately sealed to each other to define a first set of flow channels having open upstream ends, and a second set of flow channels interdigitated with said first set of flow channels and having closed upstream ends, said downstream ends of said wall segments being alternately sealed to each other such that said first set of flow channels have closed downstream ends, and said second set of flow channels have open downstream ends, such that fluid to be filtered flows substantially directly axially through said filter, through said open upstream ends of said first set of flow channels then through said wall segments then through said open downstream ends of said second set of flow channels, a first and a second of said panels 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.