Patent ID: 8181453

Claim:
An apparatus for introducing secondary air into exhaust gases, the apparatus comprising: an elongate housing for passage of exhaust gases, the housing cross-sectional area being equal throughout the length of the housing; a flange secured to an inlet of the elongate housing, the flange comprising a central opening through which exhaust gases are flowable into the elongate housing, wherein the flange comprises a plurality of channels formed in an upstream surface of the flange, the plurality of channels each extending from an outer periphery of the flange to the central opening; and a Venturi plate disposed on the upstream surface of the flange, the Venturi plate comprising a central hole that is smaller than the central opening of the flange, wherein all exhaust gases flow through the central opening and into the elongate housing via the central hole of the Venturi plate, the Venturi plate configured to create a low-pressure zone in the exhaust gases that have passed through the central hole of the Venturi plate, wherein outlets of the plurality of channels open to the low-pressure zone, the low-pressure zone and outlets of the plurality of channels being external to the central hole; wherein the low-pressure zone causes secondary non-pressurized atmospheric air outside the housing to be drawn into exhaust gases within the low-pressure zone via the plurality of channels.