Patent ID: 9192885
Filing Date: 2015-11-24
Classification: B01D,F02M

Abstract:
1. A main filter element configured for arrangement within a filter housing seal-tightly separating between an inlet and an outlet such that airflow flowing from the inlet to the outlet is required to flow through the main filter element, the main filter element comprising: a filter medium arranged as an axially elongated, circumferentially closed filter body surrounding a central axis, the circumferentially closed body having a circular ring shape cross section or oval cross section, the circumferentially closed filter body having an open interior arranged within the circumferentially closed body and on the central axis; a first end face arranged at one axial end of the circumferentially closed filter body; a second end face arrange at an opposing axial end of the circumferentially closed filter body; a first flow face formed at a radial exterior face of the circumferentially closed body and extending between the first and second end faces; a second flow face formed at a radial interior face of the circumferentially closed body and extending between the first and second end faces; wherein one of the flow faces forms an inlet flow face of the filter element and the other flow face forms an outlet flow face of the filter element; wherein the filter medium of the circumferentially closed body comprises at least one layer of filter paper with cellulose or non-woven filer media of synthetic fibers; wherein the filter medium is folded or wound encircling the central axis; a first end disk secured onto and covering the first end face of the circumferentially closed filter body, the first end disk having an open central region opening into the open interior of the circumferentially closed filter body, the first end disk including a second end disk secured onto and covering the second end face of the circumferentially closed filter body, the second end disk having an central region extending over the open interior of the circumferentially closed filter body, the second end disk including an axially extending support pipe arranged at the second flow face, the support pipe including a plurality of flow passages extending radially though the flow pipe, the flow pipe extending axially between the first end face and the second end face and encircling the open interior of the circumferentially closed filter body, the axially extending support pipe including