Filter element, e.g. for removing fat or paint from air, comprises top and bottom webs with inlet and exit openings on opposite sides of flow channel symmetry axis

摘要

Gas flow channels are formed between pleated top and bottom webs (10, 20) divided into alternating strips with rows of inlet and exit openings (40, 50) located on opposite sides of the gas flow channel symmetry axis (M). A filter element (1) comprises top and bottom webs each with parallel top and bottom fold lines (11, 12, 21, 22) that form wave or zigzag-shaped pleats. The top web (20) has its bottom fold lines (21) resting on top of the bottom fold lines (11) in the bottom web (10), such that lambda-shaped elongated flow channels (30) with an essentially chevron-shaped cross-section and essentially parallel top and bottom walls are formed between the bottom web sections (31) defined by successive bottom fold lines in the bottom web and the top web sections (32) defined by successive bottom fold lines in the top web. Inlet openings (40) are provided in the bottom web sections, located in a bottom channel wall region (33) on one side of the channel symmetry axis. Exit openings (50) are provided in the top web sections, located in a top channel wall region (36) on the other side of this symmetry axis. An Independent claim is also included for the web used to form the filter element, comprising identical width strips that alternately contain rows of inlet and exit openings, these openings having their longest side edge (41, 51) extending in the strip length direction, parallel to and at a short distance from the bottom fold line of the web.