Patent ID: 8869796

Claim:
An air filter comprising; (i) a housing with an air inlet and an air outlet, said air outlet being provided in an end wall of the housing, and (ii) a filter material in the path of air flow from the inlet to the outlet, the filter material being formed as a hollow tubular body positioned coaxial with said inlet and said outlet, said tubular body having an interior cavity and being located at one of its ends on said end wall of the housing around the air outlet and being blanked at its end opposite the air outlet so that the blanked end faces the air inlet and said air flow is inwardly through the tubular body, (iii) an electrostatically charged material positioned at the blanked end of the tubular body and externally thereof to treat inlet air to the housing before it passes through the tubular body, the electrostatically charged material being in the form of a flat pad seated on the blanked end of the tubular body and positioned directly facing the inlet perpendicular to the direction of air flow through the inlet, said pad being sized such that there is a clearance between the peripheral edge of the pad and the interior of the housing whereby the pad causes incoming air to diffuse, slow down and be diverted between the interior of the housing and the exterior periphery of the tubular body so that the air may then pass through the filter material.