Irradiation system and method

Abstract

Articles are irradiated by positioning an article to be irradiated in a processing area, controlling an atmosphere in the processing area to exclude oxygen, and applying radiation to the article in the processing area. In one embodiment, the article is positioned in the processing area by conveying the article on a top surface of a product conveyor in the processing area. One exemplary article for irradiation is a tray of fresh ground meat. The tray of fresh ground meat that is positioned in the processing area for irradiation may itself exclude oxygen as well.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) [0001] This application is a continuation of U.S. application Ser. No. 10 / 115,507 filed Apr. 2, 2002 for “Irradiation System and Method” by S. Koenck, S. Lyons, B. Dalziel, D. White, J. Kewley and V. Kennedy. [0002] U.S. application Ser. No. 10 / 115,507 claims the benefit of Provisional Application No. 60 / 280,790 filed Apr. 2, 2001 for “Irradiation System for Food or Other Articles” by S. Lyons, S. Koenck, B. Dalziel, D. White and J. Kewley, and also claims the benefit of Provisional Application No. 60 / 333,045 filed Nov. 14, 2001 for “Irradiation System for Sanitizing Mail” by S. Lyons, S. Koenck, B. Dalziel and V. Kennedy, and also claims the benefit of Provisional Application No. 60 / 359,813 filed Feb. 26, 2002 for “Irradiation System for Stationary Articles” by S. Lyons, S. Koenck, B. Dalziel and V. Kennedy.INCORPORATION BY REFERENCE [0003] The aforementioned U.S. application Ser. No. 10 / 115,507 and Provisional Application Nos. 60 / 280,790, ...

AI Technical Summary

Benefits of technology

The present invention is a method of irradiating articles by positioning them in a processing area, excluding oxygen, and applying radiation to them. This method can be used on items like trays of fresh ground meat. The technical effect of this invention is the ability to effectively and efficiently kill bacteria and other harmful microorganisms on food and other articles, while maintaining their quality and freshness.

Problems solved by technology

Ground meat such as ground beef is of particular concern for risk of food borne illness due to the fact that contaminants introduced during processing may be mixed throughout the product including the extreme product interior which receives the least amount of heat during cooking.

The most common gamma source for irradiation purposes is radioactive cobalt 60 which is simple and effective but expensive and hazardous to handle, transport, store and use.

Electrostatic accelerators are limited in maximum energy by the physical ability to generate and manage high static voltage at high power levels.

Electrostatic accelerators using Cockroft-Walton voltage multipliers are capable of energy levels of up to 1 MeV at high power levels, but the 10 MeV energy level utilized by many systems for effective irradiation is not typically available.

Conversion of the electron beam to x-ray irradiation is relatively inefficient but is effective for materials up to 18 inches or more with two-sided exposure.

In addition to food materials, recent attacks on the United States Postal Service (USPS) have occurred in which highly dangerous bacillus anthracis spores have been placed in envelopes and mailed, suggesting a need for irradiation of mail and related paper materials.

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