Method and apparatus for sterilizing mail

• US 20030129111A1
• Filed: 08/20/2002
• Published: 07/10/2003
• Est. Priority Date: 12/07/2001
• Status: Active Grant

• Current Assignee: Jimmie D. Miller
• Original Assignee: Jimmie D. Miller
• Inventors: Miller, Jimmie D., Sutton, Blair
• Granted Patent: US 6,737,029 B2
• Time in Patent Office: Days
• US Class Current: 422/292
• CPC Class Codes: A61L 2/202 Ozone
• CPC Class Codes: A62D 2101/02 Chemical warfare substances, e.g. cholinesterase inhibitors
• CPC Class Codes: A62D 3/38 by oxidation; by combustion
• CPC Class Codes: G01N 2001/025 postal items

Abstract

An apparatus for sterilizing an article of mail includes a chamber defining an airtight space and having an entrance for receiving the article of mail. A vacuum pump is coupled to the chamber for withdrawing air therefrom and, specifically, from the article of mail, this air withdrawal reducing the chamber air pressure. An ozone generator is coupled to the chamber for introducing ozone at atmospheric pressure therein following air withdrawal. This causes efficient diffusing of the ozone into the article of mail for sterilizing it against anthrax. The ozone is then withdrawn into an ozone filter that includes a non-consumable manganese dioxide catalyst for converting the ozone back into oxygen. The article of mail may be initially perforated to enhance air withdrawal and ozone diffusion. The article of mail may be embossed following ozone withdrawal to indicate completion of sterilization. The apparatus may be implemented using multiple chambers.

Claims

1. An apparatus for sterilizing an article of mail, comprising:

a first chamber defining an enclosed space and having a first entrance and a first exit;

a first conveyor extending between said first entrance and said first exit for moving the article of mail through said enclosed space of said first chamber along a first conveyance path;

a vacuum pump coupled to said first chamber for withdrawing air from the article of mail being conveyed along said first conveyance path, said vacuum pump causing a reduced air pressure within said first chamber;

a second chamber defining an enclosed space and having a second entrance and a second exit, said second chamber being positioned downstream from said first chamber;

a first auxiliary conveyor for moving the article of mail downstream between said first exit and said second entrance;

a second conveyor extending between said second entrance and said second exit for moving the article of mail through said enclosed space of said second chamber along a second conveyance path;

an ozone generator coupled to said second chamber for introducing ozone into said second chamber as the article of mail is moved therethrough; and

means in said ozone generator for substantially withdrawing ozone from said second chamber.

2. The apparatus as in claim 1 further comprising an ultraviolet lamp positioned in said first chamber along said first conveyance path for sterilizing outer surfaces of the article of mail being conveyed therealong.

3. The apparatus as in claim 1 further comprising:

a third chamber defining an enclosed space and having a third entrance and a third exit, said third chamber being positioned downstream from said second chamber;

a second auxiliary conveyor for moving the article of mail between said second exit and said third entrance;

a third conveyor for moving the article of mail between said third entrance and said third exit along a third conveyance path; and

an ozone filter coupled to said third chamber and having a non-consumable catalyst for converting ozone into oxygen.

4. The apparatus as in claim 1 further comprising an airlock positioned between said first and second chambers and surrounding said first auxiliary conveyor for retaining said reduced air pressure.

5. The apparatus as in claim 3 further comprising an airlock positioned between said second and third chambers and surrounding said second auxiliary conveyor for preventing unintended release of ozone as the article of mail is moved between said second and third chambers by said second auxiliary conveyor.

6. The apparatus as in claim 1 wherein:

respective entrances and exits of said first and second chambers are selectively movable between open and closed configurations; and

said first and second chambers are air-tight when said respective entrances and exits are in said closed configurations.

7. The apparatus as in claim 3 wherein:

said third entrance and said third exit of said third chamber are selectively movable between open and closed configurations; and

said third chamber is air-tight when said third entrance and said third exit are at said closed configurations.

8. The apparatus as in claim 3 further comprising means positioned in said third chamber for applying an indicium upon the article of mail upon passage of the article of mail through said third chamber, said indicium being indicative of completion of a sterilization cycle.

9. The apparatus as in claim 3 wherein said non-consumable catalyst is manganese dioxide.

10. The apparatus as in claim 1 further comprising a perforation roller pivotally mounted in said first chamber adjacent said first entrance and along said first conveyance path for contact with the article of mail, said perforation roller having a plurality of miniature pins arranged thereabout for perforating an outer surface of the article of mail as the article of mail is moved along said first conveyance path.

11. An apparatus for sterilizing an article of mail, comprising:

a chamber defining an enclosed space and having an entrance for receiving the article of mail into said enclosed space;

a vacuum pump coupled to said chamber for withdrawing air from the article of mail, said vacuum pump causing a reduced air pressure in said chamber;

an ultraviolet lamp positioned in said chamber for sterilizing outer surfaces of the article of mail;

an ozone generator coupled to said chamber for introducing ozone into said chamber at atmospheric pressure after an operation of said vacuum pump for diffusing said ozone into the article of mail for sterilization thereof;

an ozone filter coupled to said chamber and having a non-consumable catalyst for converting said ozone into oxygen; and

means for withdrawing said ozone from said chamber into said filter.

12. The apparatus as in claim 11 wherein said chamber includes an exit;

said apparatus further comprising a conveyor extending between said entrance and said exit for moving the article of mail through said enclosed space along a conveyance path.

13. The apparatus as in claim 11 wherein said non-consumable catalyst is manganese dioxide.

14. The apparatus as in claim 12 further comprising a perforation roller pivotally mounted in said chamber adjacent said entrance and along said conveyance path for contact with the article of mail, said perforation roller having a plurality of miniature pins arranged thereabout for perforating an outer surface of the article of mail as the article of mail is moved along said conveyance path.

15. The apparatus as in claim 12 further comprising means positioned in said chamber adjacent said exit for embossing the article of mail so as to indicate the article of mail has been sterilized.

16. The apparatus as in claim 11 wherein said ozone filter is coupled to said vacuum pump such that said vacuum pump draws air into said ozone filter.

17. A method for sterilizing an article of mail, comprising:

providing a chamber defining an enclosed space and having at least an entrance for receiving the article of mail;

withdrawing air from said chamber and from the article of mail in said chamber such that an air pressure within said chamber is reduced;

after said step of withdrawing air, introducing ozone at atmospheric pressure into said chamber for diffusing said ozone throughout said article of mail; and

withdrawing said ozone from said article of mail and from said chamber into an ozone filter having a non-consumable catalyst for converting said ozone to oxygen.

18. The method as in claim 17 further comprising subjecting the article of mail to ultraviolet light for sterilizing outer surfaces of the article of mail.

19. The method as in claim 17 further comprising perforating the article of mail prior to withdrawing air therefrom and from said chamber.

20. The method as in claim 17 further comprising imprinting an indicia on the article of mail following withdrawing said ozone, whereby to indicate completion of a sterilization cycle.