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.

1 . A method of irradiating articles, comprising: 
 positioning an article to be irradiated in a processing area;    controlling an atmosphere in the processing area to exclude oxygen; and    applying at least one of electron beam, x-ray and gamma radiation to the article in the processing area.    
   
   
       2 . The method of  claim 1 , wherein positioning the article to be irradiated in the processing area comprises: 
 conveying the article on a top surface of a product conveyor into the processing area.    
   
   
       3 . The method of  claim 2 , wherein positioning the article to be irradiated in the processing area further comprises: 
 carrying the article from an input area to the product conveyor with an input conveyor; and    carrying the article from the product conveyor to an output area with an output conveyor.    
   
   
       4 . The method of  claim 3 , wherein the input conveyor is at a first elevation, the product conveyor is at a second elevation, and the output conveyor is a third elevation, the second elevation being different from the first and third elevations.  
   
   
       5 . The method of  claim 3 , wherein positioning the article to be irradiated in the processing area further comprises: 
 changing an elevation of the article between the input conveyor and the product conveyor with a first elevator; and    changing an elevation of the article between the product conveyor and the output conveyor with a second elevator.    
   
   
       6 . The method of  claim 1 , wherein the atmosphere in the processing area is filled with a gas selected from the group consisting of nitrogen and carbon dioxide.  
   
   
       7 . The method of  claim 1 , wherein the application of at least one of electron beam, x-ray and gamma radiation to the article is performed from two opposite sides of the article.  
   
   
       8 . The method of  claim 1 , wherein the article is a tray of fresh ground meat.  
   
   
       9 . A method of irradiating fresh ground meat comprising: 
 placing the fresh ground meat in trays, the trays of fresh ground beef excluding oxygen;    positioning the trays of fresh ground meat in a processing area;    controlling a first atmosphere in the processing area to exclude oxygen; and    applying at least one of electron beam, x-ray and gamma radiation to the trays of fresh ground meat in the processing area.    
   
   
       10 . The method of  claim 9 , wherein placing the fresh ground meat in trays comprises: 
 grinding fresh meat to produce the fresh ground meat in a ribbon shape;    cutting the fresh ground meat into loaves; and    filling the trays with the loaves of fresh ground meat, all of these steps being performed in a second atmosphere controlled to exclude oxygen.    
   
   
       11 . The method of  claim 10 , wherein the second atmosphere is controlled by providing an enclosing shroud that is filled with a gas selected from the group consisting of nitrogen and carbon dioxide.  
   
   
       12 . The method of  claim 9 , wherein the first atmosphere is controlled by enclosing the processing area with a sealed conduit that is filled with a gas selected from the group consisting of nitrogen and carbon dioxide.  
   
   
       13 . The method of  claim 9 , wherein positioning the trays of fresh ground meat in the processing area comprises: 
 conveying the trays of fresh ground meat on a top surface of a product conveyor into the processing area.    
   
   
       14 . The method of  claim 13 , wherein positioning the trays of fresh ground meat in the processing area further comprises: 
 carrying the trays of fresh ground meat from an input area to the product conveyor with an input conveyor; and    carrying the trays of fresh ground meat from the product conveyor to an output area with an output conveyor.    
   
   
       15 . The method of  claim 14 , wherein the input conveyor is at a first elevation, the product conveyor is at a second elevation, and the output conveyor is a third elevation, the second elevation being different from the first and third elevations.  
   
   
       16 . The method of  claim 14 , wherein positioning the trays of fresh ground meat in the processing area further comprises: 
 changing an elevation of the trays of fresh ground meat between the input conveyor and the product conveyor with a first elevator; and    changing an elevation of the trays of fresh ground meat between the product conveyor and the output conveyor with a second elevator.    
   
   
       17 . The method of  claim 9 , wherein the application of at least one of electron beam, x-ray and gamma radiation to the trays of fresh ground meat is performed from two opposite sides.