Claims
- 1. A process for sterilizing the interior of food cartons, the process comprising:
- (a) providing a plurality of cartons, each having a bottom, a top and upright side walls;
- (b) advancing the plurality of cartons along a predetermined path;
- (c) directing reflected ultraviolet light from a mercury vapor arc lamp by a parabolic reflector into said cartons through the open tops of the cartons, the lamp being elongated and having a longitudinal axis, the predetermined path being parallel to the longitudinal axis of the lamp, said cartons having a height-to-width ratio of at least 2 to 1, and the reflector being positioned relative to the lamp so that a substantial proportion of the reflected light from said lamp impinging on side walls of the cartons at an angle of incidence of at least 13 degrees.
- 2. The process according to claim 1 including restricting the light from the lamp to wavelengths greater than 220 nanometers to avoid the formation of ozone.
- 3. The process according to claim 1 wherein the reflector is aluminum and the process includes absorbing heat from the lamp on the aluminum reflector, and including circulating fluid over the reflector on a side opposite the lamp to withdraw heat from the reflector.
- 4. The process according to claim 3, wherein the circulating fluid is air.
- 5. The process according to claim 1 including operating the lamp at a temperature from about 1100 degrees F. to about 1500 degrees F., absorbing heat from the lamp on the reflector, and cooling the reflector by causing cooling air to flow in heat exchange relation with the reflector.
- 6. The process according to claim 5 including enclosing the reflector in a housing and maintaining the temperature in the housing between about 50 degrees and 100 degrees C.
- 7. The process according to claim 6 including exposing cartons on a conveyor to ultraviolet light having a wavelength of at least 220 nanometers and an intensity of at least 16 mW/cm.sup.2.
- 8. A process for sterilizing the interior of food cartons, the process comprising:
- (a) arranging a plurality of empty food cartons with open tops on a conveyor, each of said cartons having a bottom, a top and upright side walls;
- (b) intermittently advancing the empty food cartons on the conveyor at predetermined intervals;
- (c) exposing the interior of the empty food cartons to ultraviolet radiation from an elongated ultraviolet lamp, said lamp having a longitudinal axis, said cartons advancing on the conveyor parallel to the longitudinal axis of the lamp;
- (d) limiting the wavelength of the ultraviolet radiation to at least 220 nanometers; and
- (e) reflecting the radiation from the lamp by a parabolic reflector, said reflector being positioned relative to the lamp to cause the radiation to impinge on side walls of the empty food cartons at an angle of incidence of at least 13 degrees.
- 9. The process according to claim 8 including aligning two opposite sides of the cartons with the length of the lamp and the other two sides transverse of the length of the lamp.
- 10. The process according to claim 8 wherein the reflector is metallic and the process includes cooling the reflector by passing air over the reflector.
Parent Case Info
This application is a divisional of application Ser. No. 07/955,259, filed Oct. 1, 1992, now U.S. Pat. No. 5,326,542.
US Referenced Citations (10)
Non-Patent Literature Citations (3)
Entry |
"Surface Sterilization with Advanced UV Disinfection Systems", Aquionics Brochure. |
"The Medium Pressure Arc Tube", Aquionics Information File IX. |
"Effect of Chemical and Physical Sterilants on Aseptic Packaging of Dairy Products", Patil, et al., New Zealand Journal of Dairy Science and Technology, vol. 23, pp. 175-183 (1988). |
Divisions (1)
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Number |
Date |
Country |
Parent |
955259 |
Oct 1992 |
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