Patent ID: 9718017
Date: 2017-08-01
CPC Classifications: B01D,G01N

Claim:
1. A virtual impaction particle separation inlet to fractionate airborne particulate matter (PM), the inlet comprising: a housing having a bottom, a collection tube that extends through the bottom, and a plurality of collection apertures formed in the bottom, arranged around the collection tube; a first plate disposed on top of the housing, having a plurality of acceleration nozzles disposed around the perimeter of the first plate; and a second plate disposed in the housing below the first plate, having a central aperture disposed on an upstream end the collection tube, and a plurality of separation apertures disposed around the central aperture and aligned with corresponding acceleration nozzles, wherein, when a partial vacuum is applied to the housing, ambient air including the PM flows through the plurality of acceleration nozzles and is divided into a major stream that flows through the central aperture and into the collection tube, and a minor stream that flows through the plurality of separation apertures and into the plurality of collection apertures, and the majority of the PM in the major stream has a smaller aerodynamic diameter (AD) than that of the majority of the PM in the minor stream.