US 6,695,146 B2Granted

Method for surface deposition of concentrated airborne particles

AssigneeMesoSystems Technology, Inc.

InventorsCharles J. Call, Patrick T. Call, Vanessa M. Kenning, Andrew Kamholz

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Abstract

The present invention employs a virtual impactor to separate a flow of fluid into a major flow and a minor flow, such that the minor flow contains a higher concentration of particulates of a desired size. The minor flow is directed toward an archival surface, causing the particulates to impact against and be deposited on the archival surface. Over time, the archival surface and the virtual impactor are moved relative to one another such that particulates collected at different times are deposited as spaced-apart spots on different portions of the archival surface. The particulates are stored on the archival surface until analysis of the particulates is required. The archival surface can be coated with a material that enhances the deposition and retention of the particulates and can further be coated with materials that sustain the life of biological organism particulates deposited on the archival surface.

Claims17

Dependent claims

Apparatus for separating and collecting particulates entrained in a flow of fluid, said apparatus comprising:

(a) a virtual impactor capable of separating a fluid stream into a major flow and a minor flow, the major flow including a minor portion of particulates that are above a predetermined size and the minor flow including a major portion of the particulates that are above the predetermined size, said virtual impactor including a minor flow outlet through which the minor flow exits the virtual impactor;
(b) an archival surface disposed adjacent to said virtual impactor, such that the minor flow of fluid moving through said minor flow outlet is directed toward said archival surface;
said archival surface comprising a coating disposed on the archival surface that enhances a collection and retention of the particulates on the archival surface, wherein said coating comprises at least one of:
(i) a material characterized by its ability to retain particulates impacting thereon when dry, and having a relatively low coefficient of friction when wetted, so that the particulates that have impacted on the archival surface and been retained thereon are readily washed from said surface with a liquid, said material being further characterized by being hydrophilic when dry, and hydrophobic when wetted;
(ii) a material that attracts substantially only biologic particulates of a specific desired type, for efficiently separating said particulates from the minor flow of fluid, said coating binding with the particulates of the specific desired type to retain them on the archival surface;
and
(iii) a material that changes state while being retained on the impact collection surface, a first state of the material characterized by its ability to retain the particulates that impact thereon, separating the particulates from the minor flow of fluid, and a second state of the material characterized by its ability to readily release the particulates separated from the minor flow of fluid;
and
(c) a prime mover drivingly coupled to one of said virtual impactor and said archival surface, causing a relative position of said virtual impactor and said archival surface to be selectively changed over time, so that the minor flow of fluid moving through said minor flow outlet is directed toward a different portion of said archival surface over time.

6 more elements

A method for separating a fluid flow in which particulates are entrained into a major flow that includes a minor portion of particulates above a predetermined size and a minor flow that includes a major portion of the particulates above the predetermined size, and for depositing and collecting those particulates entrained in said minor flow, comprising the steps of:

(a) providing an archival surface having at least one surface enhancement that enhances a collection and retention of the particulates on the archival surface, said at least one surface enhancement comprising at least one of an indentation and a coating, wherein said coating comprises one of:
(i) a material characterized by its ability to retain particulates impacting thereon when dry, and having a relatively low coefficient of friction when wetted, so that the particulates that have impacted on the archival surface and been retained thereon are readily washed from said surface with a liquid, said material being further characterized by being hydrophilic when dry, and hydrophobic when wetted;
(ii) a material that attracts substantially only biological particulates of a specific desired type, for efficiently separating said biological particulates from the minor flow of fluid, said coating binding with the biological particulates of the specific desired type to retain them on the archival surface;
(iii) a material that changes state while being retained on the impact collection surface, a first state of the material characterized by its ability to retain the particulates that impact thereon, separating the particulates from the minor flow of fluid, and a second state of the material characterized by its ability to readily release the particulates separated from the minor flow of fluid;
and
(iv) a material that comprises a plurality of openings into which particulates are directed;
(b) directing the fluid flow into a virtual impactor, for separating the fluid flow into the major flow and the minor flow;
(c) directing the minor flow onto the archival surface, such that particulates entrained in the minor flow are deposited on the archival surface;
and
(d) changing a relative position between the virtual impactor and the archival surface over time, such that particulates deposited on the archival surface before said relative position is changed are disposed on a different portion of said archival surface than particulates deposited after said relative position is changed.

7 more elements

(a) providing an archival surface having at least one surface enhancement that enhances a collection and retention of the particulates on the archival surface, said at least one surface enhancement comprising at least one of an indentation and a coating, wherein said coating comprises one of:
(i) a material characterized by its ability to retain particulates impacting thereon when dry, and having a relatively low coefficient of friction when wetted, so that the particulates that have impacted on the archival surface and been retained thereon are readily washed from said surface with a liquid, said material being further characterized by being hydrophilic when dry, and hydrophobic when wetted;
(ii) a material that attracts substantially only biologic particulates of a specific desired type, for efficiently separating said particulates from the minor flow of fluid, said coating binding with the particulates of the specific desired type to retain them on the archival surface;
and
(iii) a material that changes state while being retained on the impact collection surface, a first state of the material characterized by its ability to retain the particulates that impact thereon, separating the particulates from the minor flow of fluid, and a second state of the material characterized by its ability to readily release the particulates separated from the minor flow of fluid;
(iv) a matreial facilitating survival of biological organisms, so that particulates comprising biological organisms that are deposited and retained on said archival surface are preserved in a living state for an extened period of time;
and
(v) a material that comprises a plurality of openings into which particulates are directed;
(b) directing the fluid into a virtual impactor, for separating the fluid flow into the major flow and the minor flow;
(c) directing the minor flow onto the archival surface, such that particulates entrained in the minor flow are deposited on the archival surface;
and
(d) changing a relative position between the virtual impactor and the archival
(d) changing a relative position between the virtual impactor and the archival surface over time by causing relative movement between the virtual impactor and the archival surface, such that particulates deposited on the archival surface before said relative position is changed are disposed on a different portion of said archival surface than particulates deposited after said relative position is changed.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/955,481Filed 17 Sep 2001 · continuation in part
Priority: 13 Nov 1998
Published: US 2002/0157993 A131 Oct 2002
Granted: 24 Feb 2004
Term ends: Not estimatedThe source records don’t support an estimate.

Classification16 codes

G01N 1/4077
Concentrating samples: by other techniques involving separation of suspended solids
B01D 21/2455
Discharge mechanisms for the sediments: conveyor belts
B01D 45/08
By utilising inertia: by impingement against baffle separators
G01N 1/2273
In the gaseous state: atmospheric sampling

Family

Application09/191,980Parent of this continuation-in-part · filed 13 Nov 1998
Application09/265,620Parent of this continuation-in-part · filed 10 Mar 1999
Application09/494,962Parent of this continuation-in-part · filed 31 Jan 2000
US 2002/0157993 A1Pre-grant publication · published 31 Oct 2002
US 6,290,065 B1Parent of this continuation-in-part
US 6,062,392 AParent of this continuation-in-part
US 6,363,800 B1Parent of this continuation-in-part
US 6,695,146 B2This patent

From the US filing history. Foreign family members aren’t listed.