Method and apparatus for sterilizing cartons
AssigneeTetra Laval Holdings & Finance S.A.
InventorsCharles E. Sizer, Terry D. Erickson, Terrence F. Manley
Life of this patent
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Abstract
An ultraviolet (UV) sterilization system for food cartons is disclosed. An elongated UV lamp is mounted in a housing. A parabolic cylinder reflector is mounted in the housing with the focus of the reflector coinciding with the axis of the arc in the UV lamp. The shape of the parabolic reflector directs radiation from the lamp into cartons positioned on a conveyor below the lamp. The axis of the arc is parallel to the direction of movement of the cartons on the conveyor. The front surface of the reflector also absorbs heat from the lamp and heat is removed from the reflector by circulating air over the back surface of the reflector.
Claims18
Apparatus for sterilizing the interior of food cartons of the type having a bottom and upright side walls, the apparatus comprising:
- (a) conveyor means for supporting and advancing a plurality of cartons along a path;
- (b) a source of ultraviolet light, said source of ultraviolet light being elongated and having a longitudinal axis, said path being substantially parallel to said axis;
- (c) a relfector extending along said longitudinal axis and spaced from said source of ultraviolet light for reflecting light from said source of ultraviolet light toward a bottom and side walls of cartons on said conveyor means, said reflector being elongated and being transversely curved about said longitudinal axis, said reflector having opposite parabolic sides joined together along an apex parallel to said longitudinal axis, said sides being rotated from the vertical about 13 degrees toward each other and having a common focus at the source ultraviolet light;
- (d) cooling means for cooling said reflector means;
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- (e) power means for operating said source of ultraviolet light.
Apparatus for sterilizing the interior of food cartons of the type having a bottom and upright side walls, the apparatus comprising:
- (a) conveyor means for supporting a plurality of cartons along a predetermined straight path;
- (b) housing means spaced above said conveyor means;
- (c) an ultraviolet lamp having an elongated tube and electrodes at opposite ends, said tube having a central axis that is substantially parallel to said straight path;
- (d) means for mounting said ultraviolet lamp in said housing means;
- said housing means including a parabolic reflector extending along one side of said elongated tube opposite said conveyor, said reflector being spaced from said elongated tube and being shaped to focus light from the ultraviolet lamp toward a bottom and side walls of cartons on said conveyor means;
- said parabolic reflector having opposite sides joined together along an axis parallel to said central axis, said reflector sides being rotated from the vertical about 13 degrees toward each other
- (e) means for circulating a cooling fluid through said housing means to remove heat from said reflector.
Apparatus for sterilizing the interior of food cartons of the type having a bottom and upright side walls, the apparatus comprising:
- (a) conveyor means for supporting a series of cartons on a support surface that advances along a predetermined straight path;
- (b) housing means spaced above said conveyor means, said housing means including an outer shell and an inner shell, said outer shell and said inner shell each having end walls, said end walls of said inner shell being spaced from said end walls of said outer shell;
- (c) a pair of end members mounted in the respective end walls of said inner shell, an ultraviolet lamp in the form of an elongated tube having opposite ends and electrodes at the opposite ends of the tube, said tube having a central axis that is substantially parallel to said straight path, the opposite pair of ends of said tube being mounted in said end members, said ultraviolet lamp when energized produces an arc of radiation;
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- (d) an elongated reflector extending along said tube, said reflector being mounted in said inner shell to prevent fluid communication between an exterior of said tube and an interior of both of said shells, said reflector having first and second parabolic reflectors, said first and second parabolic reflectors each having a central axis and a focus, said first parabolic reflector having a central axis that intersects the central axis of the second parabolic reflector at an acute angle and the focus of the first and second parabolic reflectors coincide with said arc of radiation.
Dependencies are inferred from the claim text.