Patent ID: 7875095

Claim:
A virtual impactor device for concentrating an aerosol by separating a minor flow from a bulk flow, which comprises: a) an upstream intake member formed of opposing walls for receiving a gas stream therebetween; b) a downstream skimmer unit with skimmer unit body, said skimmer unit having an inlet aperture for receiving said gas stream from said intake member, said inlet aperture fluidly conjoined to an inlet raceway, said inlet raceway fluidly conjoined to a junction formed of said inlet raceway, two lateral flow channels and a downstream collector channel, wherein said intake unit, inlet raceway, and downstream collector channel are generally coaxial with the long axis of flow of the gas stream; c) further wherein said junction divides the skimmer unit body into four body members in plan view, said body members comprising two frontend body members and two backend body members, said two frontend body members forming said inlet raceway therebetween and said two backend body members forming said collector channel therebetween, the upstream mouth of said collector channel forming a virtual impactor void with lips and the downstream aspect of said collector channel forming an outlet from said skimmer body; d) further wherein a first of said frontend body members and a first of said backend body members form a first lateral flow channel therebetween, said first lateral flow channel having a throat bounded by a posterior wall of said first frontend body member and an anterior wall of said first backend body member, and a second of said frontend body members and a second of said backend body members form a second lateral flow channel therebetween, said second lateral flow channel having a throat bounded by a posterior wall of said second frontend body member and an anterior wall of said second backend body member; said lateral flow channels for receiving said bulk flow; and, e) further characterized in that the anterior walls of the downstream body members curve away from said lips of said virtual impactor void in a generally concavedly contoured bend for contactingly redirecting a major streamline of said bulk flow, and said throat of each said lateral flow channels is configured to bend said bulk flow along an arcuate path away from the direction of the long axis of flow, said arcuate path bending more than 90° away from the direction of the long axis of flow.