Filter, to separate air particles from air flow, has structured folds to give double spacer structures and forming channels which taper from entry to exit

摘要

A filter comprises a number of parallel flow channels. The channels have a maximum cross section at the entry, with a constant tapering to the exit. Half the flow channels take the unfiltered air with their openings at the entry into the filter, and the remaining channels take the filtered air to their openings at the exit. The channels are arranged alternately, with common walls of a filter material, through winding or layering a filter strip and a dividing strip (19), with folds along folding lines (31) to act as spacers. Each spacer is a double spacer to support the flanking filter strips with a channel structure, using identical folding surfaces (28-30) with a flat surface (34).