Patent ID: 7458284
Filing Date: 2008-12-02
Classification: G01N

Abstract:
1. A three-stage dust sampler comprising: a cap; an inlet element having a hollow column, the hollow column having a radial baffler inside and an inlet nozzle at the center of the baffler; a base having a hollow column, the hollow column having a bottom plate, a top opening and an outlet adapted to be connected to a pump, the outlet passing through the hollow column; two-stage impactors connecting the inlet element to the base, the two-stage impactors comprising: a first foam substrate supporting element having a hollow column, the hollow column having a radial baffler and 6 nozzles passing through the baffler and annularly surrounding the center of the baffler; a second foam substrate supporting element having a hollow column, the hollow column having a radial baffler and 6 nozzles passing through the baffler and annularly surrounding the center of the baffler; a third foam substrate supporting element having a hollow column, a dish and a plurality of radial arms holding the dish in the hollow column and at the center of the hollow column to form a plurality of channels between the hollow column and the dish; a first foam substrate mounted on the radial baffler of the first foam substrate supporting element with the nozzles passing through the baffler of the first foam substrate supporting element being exposed and surrounded by the first foam substrate; a second foam substrate mounted on the radial baffler of the second foam substrate supporting element and adjacent to the nozzles passing through the baffler of the second foam substrate supporting element; a third foam substrate mounted on the dish of the third foam substrate supporting element; and a final filter, wherein the inlet element, the first foam substrate supporting element, the second foam substrate supporting element and the third foam substrate supporting element are all hermetically cascaded one by one; the cap is fixed on the inlet element with an interval therebetween so that an annular inlet surrounding the inlet nozzle is formed between the cap and the inlet element; one free end of the third foam substrate supporting element is hermetically connected to the top opening of the base, and the final filter clamped between the third foam substrate supporting element and the base; and when the outlet of the base is connected to a pump, an air flow enters the inlet nozzle of the inlet element via the annular inlet, contacts the first foam substrate, passes through the nozzles of the first foam substrate supporting element, contacts the second foam substrate, passes through the nozzles of the second foam substrate supporting element, contacts the third foam substrate, passes through the channels of the third foam substrate supporting element, passes through the final filter, and enters the outlet of the base to exit from the dust sampler.