Vertical flow chemical detection portal

• US 5,915,268 A
• Filed: 12/22/1997
• Issued: 06/22/1999
• Est. Priority Date: 12/22/1997
• Status: Expired due to Term

• Current Assignee: National Technology & Engineering Solutions Of Sandia LLC (Honeywell International Inc.)
• Original Assignee: Sandia Corporation (Martin Marietta Corporation)
• Inventors: Conrad, Frank James, Linker, Kevin L., Hannum, David W.
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): WIGGINS, JOHN DAVID
• Application Number:
  US08/995,777
• Time in Patent Office: 547 Days
• Field of Search: 73/23.2, 73/23.36, 73/86.03, 73/863.71, 73/23.31, 73/28.01, 422/93, 422/94
• US Class Current: 73/23.2
• CPC Class Codes: G01N 1/24 Suction devices G01N1/22 - G01N1/2294 take precedence
• CPC Class Codes: G01N 2001/024 passengers or luggage
• CPC Class Codes: G01V 9/007 by detecting gases or particles representative of underground layers at or near the surface analysing earth materials G01N33/24; analysing gases per se G01N

Abstract

A portal apparatus for screening objects or persons for the presence of trace amounts of chemical substances such as illicit drugs or explosives. The apparatus has a test space, in which a person may stand, defined by two generally upright sides spanned by a horizontal transom. One or more fans in the transom generate a downward air flow (uni-directional) within the test space. The air flows downwardly from a high pressure upper zone, past the object or person to be screened. Air moving past the object dislodges from the surface thereof both volatile and nonvolatile particles of the target substance. The particles are entrained into the air flow which continues flowing downward to a lower zone of reduced pressure, where the particle-bearing air stream is directed out of the test space and toward preconcentrator and detection components. The sides of the portal are specially configured to partially contain and maintain the air flow.

Claims

1. An apparatus for screening an object for the presence of a target substance thereon, the apparatus comprising:

a detector;

means for generating a downward flow of air from a zone above the object to a zone below the object, whereby particles selected from the group consisting of

volatile particles of the target substance on the object which are dislodged therefrom by flow of air,

non-volatile particles of the target substance on the object which are dislodged therefrom by flow of air,

particles of the target substance present in air surrounding the object, and

combinations thereof

become entrained in the flowing air; and

means for moving the air with entrained particles from the zone below the object to the detector.

2. An apparatus according to claim 1 wherein said detector comprises an ion mobility spectrometer.

3. An apparatus according to claim 1 further comprising means for partially containing the downward flow of air.

4. An apparatus according to claim 3 wherein said means for partially containing the downward flow of air comprises a walk-through portal, said portal comprising:

two sides; and

a transom extending substantially horizontally between the respective tops of said sides, whereby said sides and said transom define therebetween a test space.

5. An apparatus according to claim 4, wherein said means for generating a downward flow of air comprises at least one fan in said transom.

6. An apparatus according to claim 4 further comprising air jet nozzles disposed in said sides for blowing air laterally within said test space.

7. An apparatus according to claim 4 wherein each of said sides comprises:

a substantially vertical inside wall;

a sloped wall below and connected to said inside substantially vertical wall; and

a substantially vertical bottom wall below and connected to said sloped wall, whereby said zone above the object is defined at least in part by said inside walls, and said zone below the object is defined at least in part by said bottom walls, said zone above comprising a larger volume than said zone below.

8. An apparatus according to claim 7 wherein said means for moving the air with entrained particles comprises:

a fan in at least one of said sides, and

at least one vent intake disposed in at least one of said bottom walls.

9. A portal apparatus for screening an object for the presence thereon of target particles, said portal apparatus comprising:

two generally vertical sides;

a transom extending substantially horizontally between the respective tops of said sides, whereby said sides and said transom define therebetween a test space;

means in said transom for generating a downward flow of air into said test space and between said sides;

a particle detector; and

means for moving air from within the test space to said particle detector.

10. An apparatus according to claim 9 wherein each of said sides comprises:

a substantially vertical inside wall;

a sloped wall below and connected to said inside wall; and

a substantially vertical bottom wall below and connected to said sloped wall, whereby said inside walls are spaced further apart than said bottom walls, thereby narrowing said test space from top to bottom.

11. An apparatus according to claim 9 wherein said means for generating a downward flow of air comprises at least one fan for blowing ambient air.

12. An apparatus according to claim 10 wherein said means for moving air from within the test space comprises:

a fan in at least one of said sides, and

at least one vent intake disposed in at least one of said bottom walls.

13. A portal apparatus for screening an object for the presence thereon of trace amounts of a target substance, said apparatus comprising:

means for generating a downward flow of air past the object whereby particles selected from the group consisting of

volatile particles of the target substance on the object which are dislodged therefrom by flow of air,

non-volatile particles of the target substance on the object which are dislodged therefrom by flow of air,

particles of the target substance present in air surrounding the object, and

combinations thereof

become entrained in the flowing air; and

means for partially containing the flowing air to direct the air towards a detector.

14. An apparatus according to claim 13, wherein said means for partially containing comprises:

two upright sides in spaced-apart relation, each of said sides comprising at least one sloping wall whereby the distance separating said sides decreases from the tops of said sides to the bottoms of said sides;

a transom extending substantially horizontally between and connecting respective tops of said sides, whereby said sides and said transom define therebetween a test space.

15. An apparatus according to claim 14 wherein said means for generating a downward flow of air comprises a pair of fans disposed in said transom.

16. An apparatus according to claim 15 wherein each of said sides comprises:

a substantially vertical inside wall;

a sloped wall below and connected to said inside wall; and

a substantially vertical bottom wall below and connected to said sloped wall, whereby said zone above the object is defined at least in part by said inside walls, and said zone below the object is defined at least in part by said bottom walls, said zone above comprising a larger volume than said zone below.

17. An apparatus according to claim 16 further comprising air jet nozzles disposed in said vertical inside walls for blowing air laterally within said test space.

18. An apparatus according to claim 17 wherein said detector comprises an ion mobility spectrometer.

19. An apparatus according to claim 18 further comprising:

a fan in at least one of said sides; and

at least one vent intake disposed in at least one of said bottom walls.

20. An apparatus for screening an object for the presence of a target substance thereon, comprising:

a detector;

means for generating a predominantly uni-directional flow of air from a zone of relative higher pressure located in a first location in relation to the object to a zone of relative lower pressure located in a second location in relation to the object, said first location being different from said second location, said flow of air passing in close proximity to the object whereby particles selected from the group consisting of

volatile particles of the target substance on the object which are dislodged therefrom by flow of air,

non-volatile particles of the target substance on the object which are dislodged therefrom by flow of air,

particles of the target substance present in air surrounding the object, and

combinations thereof

become entrained in the flowing air; and

means for moving the air with entrained particles from the zone of relative lower pressure to the detector.

21. An apparatus according to claim 20 wherein said detector comprises an ion mobility spectrometer.

22. An apparatus according to claim 20 further comprising means for partially containing the flow of air from the zone of relative higher pressure to the zone of relative lower pressure.

23. A portal apparatus for screening an object for the presence thereon of trace amounts of a target substance, said apparatus comprising:

means for generating a predominantly uni-directional flow of air, said flow of air passing in close proximity past the object from a zone of relative higher pressure to a zone of relative lower pressure whereby particles selected from the group consisting of

volatile particles of the target substance on the object which are dislodged therefrom by flow of air,

non-volatile particles of the target substance on the object which are dislodged therefrom by flow of air,

particles of the target substance present in air surrounding the object, and

combinations thereof

become entrained in the flowing air; and

means for moving the air with entrained particles from the zone of relative lower pressure to a detector.