Patent ID: 7276098

Claim:
A tangential in-line air filter configured for minimum air resistance during forced airflow operation and for optimum particulate interception by diffusion, said tangential in-line air filter comprising: a filter housing placed in-line within a forced airflow system; a filter medium within said filter housing in flow communication with said forced airflow system, said filter medium having a plurality of pleats or corrugations with a longitudinal axis parallel to said forced airflow direction, said filter medium including: an inner filter medium surrounding a center annulus, said inner filter medium having at least one end blocked or sealed; an outer filter medium peripherally surrounding said inner filter medium; and a support tube separating said inner filter medium from said outer filter medium; wherein said inner and outer filter mediums have a longitudinal axis parallel to said airflow direction; wherein said filter medium absorbs substantially all pollutants or particulates during diffusion when said airflow is not forced through said filter medium, and releases said particulates or pollutants when said airflow is forced tangentially through said filter medium.