Mail screening device

• US 20080250845A1
• Filed: 04/12/2007
• Published: 10/16/2008
• Est. Priority Date: 04/12/2007
• Status: Active Grant

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Inventors: Szarek, Matt, Damer, Kenneth Scott, Burroughs, Eric Gregory
• Granted Patent: US 7,543,478 B2
• Time in Patent Office: Days
• US Class Current: 73/28.01
• CPC Class Codes: G01N 1/2202 involving separation of sample components during sampling
• CPC Class Codes: G01N 2001/025 postal items
• CPC Class Codes: G01N 2001/028 Sampling from a surface, swabbing, vaporising

Abstract

A mail screening device for hazardous materials is disclosed. The mail screening device comprises a sample collection unit that uses air jets or air knives to dislodge residues of hazardous materials from a mail, and a detection unit that detects the hazardous materials in the exhaust air flow. Comparing to traditional mail screening systems that use belts and rollers to physically pinch a mail for sample collection, the device of the present invention is less complex and easier to operate, thereby reducing installation, maintenance and replacement costs.

Claims

1. A mail screening device for hazardous materials, comprising:

a sample collection unit comprising a nozzle that produces a flow of pressured air to dislodge residues of a hazardous material from a mail; and

a detection unit that detects said hazardous material in an exhaust flow containing said residues of said hazardous material.

2. The mail screening device of claim 1, further comprising a mail feeder that delivers mails to said sample collection unit.

3. The mail screening device of claim 2, wherein said mail feeder is a conveyer belt.

4. The mail screening device of claim 1, wherein said a sample collection unit comprises multiple nozzles arranged to produce air flows that form different angles with surfaces of said mail.

5. The mail screening device of claim 1, wherein said nozzle produces an air flow in the shape of an air knife.

6. The mail screening device of claim 1, wherein said nozzle produces a pulsed air flow.

7. The mail screening device of claim 6, further comprising an electronic solenoid-activated valve that controls timing of said pulsed air flow.

8. The mail screening device of claim 1, wherein said nozzle produces a continuous air flow.

9. The mail screening device of claim 1, wherein said nozzle produces an air flow of variable pressure.

10. The mail screening device of claim 1, wherein said nozzle produces an air flow of constant pressure.

11. The mail screening device of claim 1, wherein said nozzle produces an air flow in the shape of an air jet.

12. The mail screening device of claim 1, further comprising an air source.

13. The mail screening device of claim 12, wherein said air source is a compressed air system or a blower-driven air system.

14. The mail screening device of claim 1, wherein said detection unit comprises an in-line analyzer that detects said hazardous material in said exhaust flow in real time.

15. The mail screening device of claim 1, wherein said sample collection unit comprises a particle/aerosol collector that traps said residues of the hazardous material in said exhaust flow.

16. The mail screening device of claim 1, wherein said hazardous material is selected from the group consisting of chemical warfare agents, biological warfare agents, explosives, non-traditional agents or dusty agents.

17. The mail screening device of claim 1, wherein said hazardous material is a bacteria spore.

18. A method for detecting hazardous materials in the interior, or on the exterior of a mail, comprising:

subjecting said mail to a stream of pressured air to dislodge residues of a hazardous material from said mail;

collecting an exhaust flow of air from said mail; and

detecting said hazardous material in said exhaust flow.

19. The method of claim 18, wherein said hazardous material is detected in real time.

20. The method of claim 18, wherein said mail is subjected to multiple streams of pressured air to dislodge residues of said hazardous material from said mail.