Patent ID: 8741016

Claim:
A filter device filtering a fluid, the filtering device comprising: an inlet flow face at a first axial end of said filter device; an outlet flow face at an opposing second axial end of said filter device; a spirally wound compact filter comprising a corrugated filter material layer; a flat filter material layer overlaid onto said corrugated filter material layer, wherein said corrugated and flat layers are spirally wound about a central axis of the filter device providing a spirally wound filter body having an inlet flow face on a raw side of said spirally wound filter body and an axially opposing outlet flow face on a clean side of said spirally wound filter body, axially opposing in a direction of said central axis, wherein said wound filter body has a plurality of axially extending gas flow passages extending in between said raw and clean sides, wherein said gas flow passages are alternatingly closed off, wherein fluid flows axially within said compact filter element from said inlet flow face of said spirally wound filter body to said outlet flow face of said spirally wound filter body in said direction of said central axis; a star filter comprising a filter material having folds arranged into a star shape, wherein said star filter radially and circumferentially surrounds said compact filter, said spirally wound compact filter arranged within an interior of said star filter; wherein said folds extend in the direction of the central axis between opposing axial ends of said star filter, wherein said compact filter and said start filter are arranged to filter in parallel, each filtering a different portion of said fluid to be filtered; a circumferentially extending first terminal sealing surface arranged on a first one of said flow faces of said filter device, said first terminal sealing surface secured onto and seal-tightly covering an axial end face of filter material folds of said star filter from a radially outer flow face of said star filter to a radially inner flow face of said star filter; wherein said first terminal sealing surface extends radially inwardly relative to said central axis from said radially inner flow face of said star filter to terminate at and seal against a radial outer surface of the spirally wound filter body; wherein the axially opposed flow faces of the spirally wound filter body remain uncovered by the first terminal sealing surface; wherein a first portion of said fluid to be filtered enters said spirally wound compact filter at said axial raw side of said compact filter, flowing axially through said gas flow passages to exit said spirally wound compact filter at said axially opposed clean side at a radially interior clean side at an interior of said star filter, wherein a different second portion of said fluid to be filtered enters a radially outer face of said star filter, flows radially inwardly through said star filter material folds and exits said star filter at said radially interior clean side at an interior of said star filter.