Device and method for detecting hazardous material in mail
View Patent ↗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.
1. A mail screening device for hazardous materials, comprising:
a sample collection unit comprising:
at least one nozzle arranged in a configuration that mimics the pinching mechanism of physical pinching rollers or belts, wherein said nozzle produces a flow of pressured air capable of dislodging residues of a hazardous material contained in the interior and on the exterior of a mail package; 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 , wherein said a sample collection unit comprises multiple nozzles arranged to produce air flows that form different angles with surfaces of said mail.
3. The mail screening device of claim 1 , wherein said nozzle produces an air flow in the shape of an air knife.
4. The mail screening device of claim 1 , wherein said nozzle produces a continuous air flow.
5. The mail screening device of claim 1 , wherein said nozzle produces an air flow of variable pressure.
6. The mail screening device of claim 1 , wherein said nozzle produces an air flow of constant pressure.
7. The mail screening device of claim 1 , wherein said nozzle produces an air flow in the shape of an air jet.
8. 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.
9. 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.
10. 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.
11. The mail screening device of claim 1 , wherein said hazardous material is a bacteria spore.
12. The mail screening device of claim 1 , further comprising a mail feeder that delivers mails to said sample collection unit.
13. The mail screening device of claim 12 , wherein said mail feeder is a conveyer belt.
14. The mail screening device of claim 1 , wherein said nozzle produces a pulsed air flow.
15. The mail screening device of claim 14 , further comprising an electronic solenoid-activated valve that controls timing of said pulsed air flow.
16. The mail screening device of claim 1 , further comprising an air source.
17. The mail screening device of claim 16 , wherein said air source is a compressed air system or a blower-driven air system.
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 that mimics the pinching mechanism of physical pinching rollers or belts to dislodge residues of a hazardous material from the interior and exterior of 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.