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Title:
IMPROVED DISINFECTION OF CONVEYOR LINE WITHOUT INCREASED LONGITUDINAL FOOTPRINT
Document Type and Number:
WIPO Patent Application WO/2004/064875
Kind Code:
A2
Abstract:
A disinfection system (10) for use in connection with a conveyor is disclosed. The conveyor (12) has a transport segment (24) and a return segment (26), and one or more treatment segments (28) and (30) are provided as part of the return segment. In each treatment segment, the conveyor line (22) is preferably redirected and routed at an angle to the line (22) in the transport segment (24), is more preferably redirected and routed at an angle that is substantially perpendicular to the line in the transport segment (24), and is most preferably redirected and routed in a substantially vertical direction. In the treatment segment (28) or (30), one or more UV radiation units (14) are aligned substantially vertically and are disposed in close proximity to and substantially parallel to the line (22) passing through the treatment segment (28) or (30).

Inventors:
NOLEN GARY (US)
RHEINGANS JOE (US)
Application Number:
PCT/US2004/001503
Publication Date:
August 05, 2004
Filing Date:
January 21, 2004
Export Citation:
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Assignee:
NOLEN GARY (US)
RHEINGANS JOE (US)
SAFE FOODS CORP (US)
International Classes:
A61L2/10; (IPC1-7): A61L/
Foreign References:
US6710357B12004-03-23
US6132784A2000-10-17
US5042540A1991-08-27
Attorney, Agent or Firm:
Rogers, Mark (4801 North Shore Drive North Little Rock, AR, US)
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Claims:
What is claimed is:
1. A method comprising: (a) circulating a line of a conveyor through a transport region and a return region so that workpieces are moved by said line through said transport region and are not moved by said line through said return region; (b) in said return region, moving said line through a treatment region, a substantial portion of a path of said line in said treatment region being disposed substantially perpendicular to a substantial portion of a path of said line in said transport region; and (c) disposing a radiation source adjacent to said substantial portion of said path of said line in said treatment region.
2. The method of claim 1, wherein said substantial portion of said path of said line in said treatment region is disposed substantially vertically.
3. The method of claim 1, wherein step (c) comprises disposing a UV radiation source adjacent to said substantial portion of said path of said line in said treatment region.
4. The method of claim 1, wherein said workpieces are selected from the group consisting of food products, containers, and packaging.
5. The method of claim 1, wherein said line comprises a belt.
6. The method of claim 1, wherein step (c) comprises: disposing said radiation source adjacent to said substantial portion of said path of said line in said treatment region so that said line passes in close proximity to opposing sides of said radiation source.
7. The method of claim 1, wherein said treatment region is disposed below said transport region.
8. A method, comprising: (a) circulating a line of a conveyor through a transport region and a return region so that workpieces are moved by said line through said transport region and are not moved by said line through said return region; (b) in said return region, passing said line over a first roller, then under a second roller, and then over a third roller; and (c) disposing a radiation source adjacent to a first portion of said line disposed between said first and second rollers or between said second and third rollers.
9. The method of claim 8, wherein said first portion of said line disposed between said first and second rollers or between said second and third rollers is disposed substantially vertically.
10. The method of claim 8, further comprising: in said return region, after passing said line over said third roller, passing said line under a fourth roller, said fourth roller being disposed so that a second portion of said line disposed between said third and fourth rollers is also adjacent to said radiation source.
11. The method of claim 10, wherein said second portion of said line disposed between said third and fourth rollers is disposed substantially vertically.
12. The method of claim 8, wherein said line comprises a belt.
13. The method of claim 8, wherein said workpieces are selected from the group consisting of food products, containers, and packaging.
14. The method of claim 8, wherein said treatment region is disposed below said transport region.
15. A combination, comprising: a radiation source having first and second sides opposite one another; and a conveyor line, said conveyor line being routed so that said conveyor line passes in close proximity to said first side of said radiation source and in close proximity to said second side of said radiation source.
16. The combination of claim 15, wherein said radiation source comprises a UV radiation source.
17. The combination of claim 15, wherein said radiation source comprises a plurality of UV bulbs, and a housing, said plurality of UV bulbs being disposed within said housing.
18. The combination of claim 15, wherein said conveyor line is routed over a transport region and a return region so that workpieces are moved by said line through said transport region and are not moved by said line through said return region, said conveyor line passing in close proximity to said first side of said radiation source and in close proximity to said second side of said radiation source in a portion of said return region.
19. A combination, comprising: a conveyor line, said conveyor line comprising a transport region and a return region so that workpieces are moved by said line through said transport region and are not moved by said line through said return region; said return region comprising a treatment region, a substantial portion of a path of said line in said treatment region being disposed substantially perpendicular to a substantial portion of a path of said line in said transport region; and a treatment unit disposed adjacent to said line in said treatment region.
20. The combination of claim 19, wherein said treatment unit comprises a radiation unit.
21. The combination of claim 19, wherein said treatment unit comprises a UV radiation unit.
22. The combination of claim 19, wherein said substantial portion of said path of said line in said treatment region is disposed vertically.
23. The combination of claim 22, wherein said substantial portion of said path of said line in said treatment region is disposed below said substantial portion of said path of said line in said transport region.
24. The combination of claim 20, wherein said radiation unit has first and second sides opposite one another, and wherein said line in said treatment region passes in close proximity to said first side of said radiation source and in close proximity to said second side of said radiation source.
25. The combination of claim 20, wherein said treatment unit is disposed in close proximity to said line at a location at which said line is undergoing a bend or turn.
Description:
IMPROVED DISINFECTION OF CONVEYOR LINE WITHOUT INCREASED LONGITUDINAL FOOTPRINT This application claims the benefit of U. S. Provisional Application Ser. No.

60/441,945, filed on January 21,2003, the disclosure of which is incorporated herein by reference.

Background of the Invention The present invention relates to disinfection of conveyors and, more particularly to disinfection of conveyors using ultraviolet (UV) lighting or radiation.

Cross contamination of food products, containers, packaging, and other surfaces during food processing is a problem and concern. Surfaces associated with food processing will from time to time be exposed to microbial contamination. If such a surface is left untreated, the surface can contribute to cross contamination of food products, containers, packaging, and the like that later come into contact with that surface. This is particularly true for conveyors that come into contact with large numbers of workpieces.

Food products, containers, packaging, and other such workpieces are often moved through processing steps using a conveyor having an endless belt, chain, band, cord, rope, or the like. It is known to use UV lighting to disinfect workpieces as the workpieces are moved by a conveyor. Treating food products on a conveyor will inherently provide some UV disinfection to the conveyor as well, but there are a number of disadvantages to relying upon this incidental exposure to disinfect a conveyor. For example, the portions of the conveyor upon which the workpieces rest will usually not be exposed to the UV radiation, leaving potentially large areas untreated. Further, the effectiveness of UV radiation diminishes rapidly, likely exponentially, with distance from the treated surface, and UV lamps used to disinfect workpieces on a conveyor belt must typically be disposed an undesirably far distance from the conveyor to allow room for the workpieces to pass.

U. S. Patent No. 5,042, 540, issued in 1991 to Gorlich, also discloses the use of a UV drying and disinfectant assembly 39 to disinfect belts 15 and 20 in a region of the conveyor in which the belts 15 and 20 do not carry workpieces. The disclosure of U. S. Patent No.

5,042, 540 is incorporated herein by reference. A system such as the one disclosed in the'540 patent offers advantages and helps to reduce the risk that the conveyor will contribute to cross contamination of workpieces carried thereon. Still, a system such as the one disclosed in the

'540 patent has a number of disadvantages. For example, the system appears to irradiate at least a portion of a substantially horizontal, wet belt by positioning the treating UV bulb beneath the wet belt. Allowing water and debris to drip from a belt onto a UV bulb or onto a protective, transparent lens or shield associated with that UV bulb can pose a safety hazard and can decrease the efficiency of the bulb as water and other debris are deposited onto the bulb or onto the protective, transparent shield disposed between the bulb and the belt. Also, the assembly 39 of the'540 patent appears to dispose the UV bulbs transverse or perpendicular to the direction of travel of the belts 15 and 20. Particularly if the belts 15 and 20 move with any speed, the assembly 39 of the'540 patent would likely offer an undesirably short exposure time. An effort to provide greater exposure time might lead to the addition of additional assemblies 39 or to the slowing of the speed of the belts 15 and 20, but neither of these options is particularly attractive. Adding assemblies would likely require an undesirable increase in the longitudinal footprint of the conveyor. Particularly since, in a processing line, time is money, slowing the belt speed would also be undesirable in many situations.

Summary of the Invention It is therefore an object of the present invention to provide a safe and reliable system for disinfecting a conveyor that offers extended treatment times without increasing the longitudinal footprint of the conveyor or decreasing the speed at which the conveyor operates.

It is a further object of the present invention to provide a system for disinfecting a conveyor that reduces the safety risks associated with allowing moisture and debris to drip from a treated area onto a UV radiation housing disposed below that treated area.

It is a further object of the present invention to provide a system for disinfecting a conveyor that reduces the risk that moisture and debris will reduce the efficiency with which the system irradiates the conveyor.

It is a further object of the present invention to provide a system for disinfecting a conveyor that makes efficient use of workspace to provide for increased UV radiation exposure times without increasing the longitudinal footprint of the conveyor or decreasing the speed at which the conveyor operates.

It is a still further object of the present invention to provide a system for disinfecting a

conveyor that offers the flexibility to incrementally and significantly increase UV radiation exposure times without increasing the longitudinal footprint of the conveyor or decreasing the speed at which the conveyor operates.

Toward the fulfillment of these and other objects and advantages, a disinfection system for use in connection with a conveyor is disclosed. The conveyor has a transport segment and a return segment, and one or more treatment segments are provided as part of the return segment. In each treatment segment, the conveyor line is preferably redirected and routed at an angle to the line in the transport segment, is more preferably redirected and routed at an angle that is substantially perpendicular to the line in the transport segment, and is most preferably redirected and routed in a substantially vertical direction. In the treatment segment, one or more UV radiation units are aligned substantially vertically and are disposed in close proximity to and substantially parallel to the line passing through the treatment segment.

Brief Description of the Drawings The above brief description, as well as further objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of the presently preferred but nonetheless illustrative embodiments in accordance with the present invention when taken in conjunction with the accompanying drawings, wherein: FIG. 1 is a side elevation view of a disinfection system of the present invention; FIG. 2 is side elevation view of an alternate embodiment of a disinfection system of the present invention; FIG. 3 is a side elevation view of a preferred embodiment of a disinfection system of the present invention; and FIG. 4 is a side elevation view of an alternate embodiment of a disinfection system of. the present invention.

Detailed Description of the Preferred Embodiment Referring to Fig. 1, the reference numeral 10 refers in general to a disinfection system of the present invention. The system 10 comprises a conveyor 12 and one or more treatment units 14. The conveyor 12 may take any number of different forms and may be selected from

among most any conventional conveyors known in the art, including but not limited to those using belts, chains, rollers, hooks, or the like to move workpieces 16. The treatment units 14 are preferably radiation sources and are more preferably UV radiation units. UV radiation units 14 are widely known in the art and typically include a bank of UV bulbs 17 in a protective housing 19. The housing 19 supports the UV bulbs 17 in close proximity to an area to be irradiated, protects the UV bulbs 17, and shields users and the outside surrounding environment from the radiation emitted by the bulbs 17. The UV radiation units 14 may take any number of forms, shapes, sizes, and configurations. Each UV radiation unit 14 may be as simple as a single UV bulb 17 or may take the form of most any conventional UV radiation unit known in the art.

The conveyor 12 of the present system 10 has a frame 18, a plurality of rollers 20, and an endless conveying line 22. As used herein, the term"line"22 includes any known looped or endless conveyor means used in conventional conveyors, including but not limited to belts, chains, cables, bands, ropes, cords, and the like. Although not required, the line 22 may have cleats 23 (Fig. 3) disposed on an upper surface thereof. The conveyor 12 has a transport segment 24 through which a point on the line 22 moves to carry or convey workpieces 16 and a return segment 26, through which a point on the line 22 must travel to return to the transport segment 24. In Figs. 1-3, the transport segment 24 is the segment traversed by a point on the line 22 as the point moves from roller 20a to roller 20b, and the return segment 26 is the segment traversed by a point on the line 22 as the point moves from roller 20b back to roller 20a. It is understood that the beginning of the transport segment 24 is determined by the location at which workpieces 16 are initially placed on or suspended from the line 22, and the beginning of the return segment 26 is determined by the location at which the last workpieces 16 are removed from the line 22, regardless of the general direction of travel of the line 22 at those locations. It is understood that rollers 20 may but need not define the beginning of the transport segment 24 or the beginning of the return segment 26. Over a substantial portion of the length of the transport segment 24 and the length of the return segment 26, the line 22 positioned in the transport segment 24 will be aligned substantially parallel with and moving in the opposite direction of the line 22 in the return segment 26.

The line 22 will typically be disposed substantially horizontally over a substantial portion of the length of the transport segment 24 and over a substantial portion of the length of the return segment 26.

The return segment 26 of the conveyor 12 includes one or more treatment segments 28 and 30. In Fig. 1, the treatment segment 28 is the segment traversed by a point on the line 22 as the point moves from roller 20c to roller 20e. The rollers 20c, 20d, and 20e are disposed so that the distance traveled by a point on the line 22 as it travels from roller 20c, past roller 20d, and to roller 20e is substantially greater than the linear distance between roller 20c and 20e. In that regard, the distance traveled by a point on the line 22 as the line 22 moves through the treatment segment 28 is preferably at least four times the linear distance between roller 20c and roller 20e, is more preferably at least six times the linear distance between roller 20c and roller 20e, and is most preferably at least ten times the linear distance between roller 20c and roller 20e. In Fig. 2, the first treatment segment 28 is the segment traversed by a point on the line 22 as the line 22 moves from roller 20c to roller 20e, and the second treatment segment 30 is the segment traversed by a point on the line 22 as the line 22 moves from roller 20f to 20h. Over a substantial portion of the length of each treatment segment 28 and 30, the line 22 in the treatment segment will be disposed at an angle with the line 22 in the transport segment 24, will more preferably be disposed substantially perpendicular to the line 22 in the transport segment 24, and will most preferably be aligned substantially vertically. In Fig. 3, the treatment segment 28 is the segment traversed by a point on the line 22 as the line 22 moves from roller 20c to roller 20g. Over a substantial portion of the length of each treatment segment 28 and 30, the line 22 in the treatment segment will be disposed at an angle with the line 22 in the transport segment 24, will more preferably be disposed substantially perpendicular to the line 22 in the transport segment 24, and will most preferably be aligned substantially vertically.

In each treatment segment 28 and 30, at least one UV radiation unit 14 is disposed adjacent to the line 22, with a UV bulb 17 being supported in close proximity to the line 22.

A protective transparent lens or shield may be positioned between the bulb 17 and the adjacent line 22 and preferably has a longitudinal axis that is disposed substantially vertical and substantially parallel with the longitudinal axis of the adjacent line 22. In the embodiments shown in Figs. 1 and 2, each treatment segment 28 and 30 has two UV radiation units 14 to further increase exposure times without a corresponding increase in the longitudinal footprint 32 of the conveyor or a corresponding decrease in line 22 speed. In Fig. 3, a single UV radiation unit 14 is positioned between adjacent vertical sections of the line 22, making highly efficient use of the radiation emitted by the UV radiation unit 14 and

providing for increased exposure time offered by a single unit 14. The UV radiation units 14 are aligned so that debris or moisture may drip or fall from the vertically disposed line 22 as the line travels through the treatment segment 28 or 30 without dripping or falling onto the UV radiation unit 14.

In an alternate embodiment disclosed in Fig. 4, UV bulbs 17 are positioned in close proximity to line 22 in one or more locations at which the line 22 is being turned or redirected, such as at rollers 20d and 20f. This provides for greater exposure into the cracks, seams, and links of line 22, where cells or other contaminants can be more difficult to treat when the belt is flat. It is understood that the radiation units 14 may be positioned near other bends or turns in the line 22 as well.

In operation, the conveyor is activated so that the line 22 begins to move. Workpieces 16 are placed on and taken from the line 22 as a point of the line 22 travels through the transport segment 24. After performing the desired work in the transport segment 24, a point of the line 24 then passes to the return segment 26. At some time as a point of the line 22 passes through the return segment 26, it passes through at least one treatment segment 28 and 30. As the point of the line passes through a treatment segment 28 and 30, at least one UV radiation unit 14 irradiates the point for a desired radiation exposure time to obtain a desired degree of disinfection. Because each point of the line 22 passes through at least one treatment segment 28 and 30 with each complete circuit or revolution of the line 22 about the conveyor 12, any point of the line bearing contamination that might have survived the UV radiation exposure on any particularly revolution will be repeatedly exposed to UV radiation as the line completes repeated circuits or revolutions. As best seen in Fig. 3, the line 22 is routed so that the upper, workpiece-bearing surface of the line 22 (such as the cleated 23 upper surface) are treated by the UV disinfection units 14. By aligning each treatment segment 28 and 30 substantially vertically, it is possible to provide for a longer radiation exposure time without increasing the longitudinal footprint of the conveyor or slowing the line 22 speed. Disposing these treatment segments 28 and 30 in areas below the transport segment 24 also makes efficient use of workspace that would often otherwise go unused. By using multiple UV radiation units 14 and multiple treatment segments 28 and 30, the system 10 offers the flexibility of significantly increasing or decreasing radiation exposure times by simply turning on or off the desired number of disinfection units 14. By positioning the UV radiation units 14 vertically alongside vertical portions of the line 22, the system 10 also

reduces the risks and inefficiencies that might otherwise result from allowing moisture and debris to drip or fall from the line 22 being treated onto a UV radiation unit 14.

Other modifications, changes and substitutions are intended in the foregoing, and in some instances, some features of the invention will be employed without a corresponding use of other features. For example, although the treatment units 14 are preferably UV radiation units, it is understood that the treatment units 14 may provide any of a wide variety of treatments in which it might be desirable to provide for increased treatment times without increasing the longitudinal footprint 32 of the conveyor 12. Also, although it is preferred to dispose the treatment segments 28 and 30 substantially vertically, it is understood that the treatment segments 28 and 30 may be disposed, aligned, configured, and routed in any number of different manners. Further, although the preferred embodiments position the treatment segments 28 and 30 below the transport segment 24, it is understood that the treatment segments 28 and 30 may be positioned in any number of locations and positions, such as, for example, above the transport segment 24. It is of course understood that all quantitative information is given by way of example only and is not intended to limit the scope of the present invention.