WO2004064874A2

WO2004064874A2 - Underside disinfection of workpieces on a conveyor belt

Info

Publication number: WO2004064874A2
Application number: PCT/US2004/001470
Authority: WO
Inventors: Joe Rheingans; Gary Nolen
Original assignee: Safe Foods Corporation
Priority date: 2003-01-21
Filing date: 2004-01-21
Publication date: 2004-08-05
Also published as: WO2004064874A3

Abstract

A disinfection system 10 is disclosed. A conveyor having rollers 16, 18, 20 and a conveyor belt 14 is provided, along with a UV radiation unit 22. The conveyor belt 14 passes first over an upper roller 16, then under an adjacent lower roller 18, and then over another upper roller 20 to form a trough 21. The UV radiation unit 22 is supported in the trough 21, disposed so that workpieces 24 passing along the conveyor belt 14 will pass over the UV radiation unit 22 without coming into contact with it. As the conveyor belt 14 moves workpieces 24 through the treatment section, over and past the troughs 21 and the UV radiation units 22 disposed in the troughs 21, these UV radiation units 22 treat the undersides of the workpieces 24. The UV radiation units 22 in the troughs 21 also treat the belt 14 while it is free from workpieces 24 in each trough 21. Upper or side UV radiation units 44 may also be provided for 360 degree disinfection.

Description

UNDERSIDE DISINFECTION OF WORKPIECES ON A CONVEYOR BELT

This application claims the benefit of U.S. Provisional Application Ser. No. 60/441,913, filed on January 21, 2003, the disclosure of which is incorporated herein by reference.

Background of the Invention The present invention relates to disinfection using ultraviolet (UV) lighting or radiation, and more particularly, to underside or 360° disinfection of workpieces carried on a conveyor belt. It is known to treat food products, surfaces associated with food processing, and other workpieces with UV radiation to remove microbial contamination. It is also known to position a UV lamp or bulb over a conveyor belt to treat products passing under the bulb. One problem with this approach is that the underside or bottom portion of the product that rests on the conveyor belt is not treated by the overhead bulb, leaving a potentially large area untreated. U.S. Patent No. 6,132,784 attempts to address this problem by positioning powered rollers, rather than a belt, under the UV lamp and rotating the product (such as apples) under the lamp for more complete UV treatment. The disclosure of U.S. Patent No. 6,132,784 is incorporated herein by reference. This offers some advantages, but many if not most products one might wish to treat using UV radiation are not well suited for rotation under a UV lamp using such powered rollers.

U.S. Patent Nos. 4,877,964 and 5,958,336 attempt to address the problem of treating the underside of workpieces on a conveyor by using spaced, powered rollers and positioning UV lamps or bulbs below or between the spaced, powered rollers. Also, U.S. Patent No. 5,597,597 attempts to address the problem of treating the underside of workpieces on a conveyor by using a mesh conveyor. The disclosures of U.S. Patent Nos. 4,877,964,

5,597,597, 5,958,336, and 6,132,784 are incorporated herein by reference. These systems disclosed in these patents offer some advantages, but these systems are for use in connection with a conveyor that uses a series of uncovered rollers rather than using a conveyor belt. Under some circumstances, it may be desirable to use a conveyor having an endless conveyor belt, such as to better control and contain moisture and other debris that might fall from workpieces being carried. Summary of the Invention

It is therefore an object of the present invention to provide a system that provides for underside treatment of workpieces being carried on conveyor belts.

It is a further object of the present invention to provide a system of the above type that provides for underside disinfection of workpieces being carried by conveyors.

It is a further object of the present invention to provide a system of the above type in which the treatment is disinfection using UV radiation.

It is a further object of the present invention to provide a system of the above type that provides 360 degree disinfection of workpieces carried on a conveyor belt. It is further object of the present invention to provide a system of the above type that allows the underside of a workpiece carried by a conveyor belt to be treated without the need to remove the workpiece from the belt.

It is further object of the present invention to provide a system of the above type that provides for workpiece on a conveyor belt to be automatically moved from one location on the surface of the belt to another location on the surface of the belt.

It is a further object of the present invention to provide for thorough workpiece and belt disinfection in a single area.

It is a further object of the present invention to make efficient use of radiation emitted from a UV bulb by positioning objects to be disinfected in close proximity to multiple areas about its circumference.

It is a further object of the present invention to make efficient use of radiation emitted from a UV bulb by positioning objects to be disinfected in close proximity to at least four areas about its circumference.

It is a further object of the present invention to provide a system of the above type that allows for improved disinfection of both a workpiece and of a belt in the same region.

Toward the fulfillment of these and other objects and advantages, a disinfection system is disclosed. A conveyor having rollers and a conveyor belt is provided, along with a UV radiation unit. The conveyor belt passes first over an upper roller, then under an adjacent lower roller, and then over another upper roller to form a trough. The UV radiation unit is supported in the trough, disposed so that workpieces passing along the conveyor belt will pass over the UV radiation unit without coming into contact with it. As the conveyor belt moves workpieces through the treatment section, over and past the troughs and the UV radiation units disposed in the troughs, these UV radiation units treat the undersides of the workpieces. The UV radiation units in the troughs also treat the belt while it is free from workpieces in each trough. Upper or side UV radiation units may also be provided for 360 degree disinfection.

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 sectional, side elevation view of a system of the present invention; and FIG. 2 is an overhead view of a portion of a 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, having an endless belt 14 and rollers 16, 18, and 20, and a treatment unit 22, that is preferably a UV radiation unit

The conveyor 12 may take any number of different forms and may be most any conventional conveyor known in the art that uses an endless belt to carry workpieces 24 resting on the belt 14. The belt 14 and rollers 16, 18, and 20 may be of most any conventional construction. As best seen in Fig. 1, roller 18 is disposed below rollers 16 and 20 and is preferably centered between rollers 16 and 20. Belt 14 passes over roller 16, under roller 18, and over roller 20 to form a relatively narrow, shallow trough 21 that will be described in more detail below. Additional rollers, such as rollers 26, 28, 30, 32, 34, and 36 may also be provided and arranged as desired to form additional troughs 21 that may be sized and positioned as desired.

The treatment units 22 are preferably radiation sources and are more preferably UV radiation units. UV radiation units 22 are widely known in the art and typically include a UV bulb that is housed in a protective transparent shell or housing. Although not preferred, the

UV radiation unit 22 may include a reflector. The UV radiation unit 22 may take any number of forms, shapes, sizes, and configurations. Each UV radiation unit 22 may be as simple as a single UV bulb or may take the form of most any conventional UV radiation unit known in the art.

The UV radiation unit 22 is disposed in trough 21. It is preferably disposed so that a top surface of unit 22 is below a top surface of the belt 14 at the location where the belt passes over roller 16 and below a top surface of the belt 14 at the location where the belt 14 passes over roller 20. The top surface of the unit 22 is also disposed so that it will be in close proximity to, but not in contact with, the undersides or lower surfaces of the workpieces 24 as the workpieces 24 pass over the trough 21 and unit 22. The size and shape of the trough 21 is selected so that the unit 22 is in close proximity to, but not in contact with, a segment of the belt 14 that is disposed between rollers 16 and 18, in close proximity to, but not in contact with, roller 18, and in close proximity to, but not in contact with, a segment of the belt 14 disposed between rollers 18 and 20.

The number of troughs 21 formed and units 22 used will vary depending upon the needs of the system 10. Multiple units 22 will typically be used to obtain the desired degree of disinfection. The troughs 21 and units 22 will typically be aligned such that a line 38 passing through center points of the units 22 will be parallel with and equidistant between a line 40 passing through center points of the upper rollers 16, 20, 28, 32, and 36 and a line 42 passing between center points of the lower rollers 18, 26, 30, and 34.

The workpieces 24 may take any number of different shapes, sizes, and forms and may be virtually any item that a user wishes to carry on a conveyor belt 14. It is preferred that the workpiece 24 be of sufficient size and stiffness to avoid falling into or becoming lodged or stuck in a trough 21. The length of the workpiece 24 measured along the direction of travel will preferably be greater than the distance between the centers of rollers 16 and 20, will more preferably be greater than approximately twice the distance between the centers of rollers 16 and 20, and will most preferably be greater than approximately three times the distance between the centers of rollers 16 and 20.

It will typically be desired to provide 360 degree treatment or disinfection of the workpieces 24, so additional treatment units 44, preferably UV radiation units, will typically be provided. These UV radiation units 44 may be disposed any number of places, such as above or to the sides of the belt 14, with the UV radiation units 44 being disposed so that workpieces 24 passing the UV radiation units 44 will come into close proximity with the units 44 without coming into contact with the units 44. It is understood that the overhead or side UV radiation units 44 may be positioned in any number of locations and need not be disposed immediately above the troughs 21. It is also understood that different shapes, sizes, and configurations of UV radiation units 22 and 44 may be used depending upon the location and desired performance characteristics of the unit 22 and 44 at any particular location. In operation, the UV radiation units 22 and 44 are turned on, and the conveyor 12 is activated so that the belt 14 begins moving. Workpieces 24 are placed on the belt 14 upstream of the troughs 21 and UV radiation units 22 and 44. As the belt 14 moves to and through the treatment region or regions in which the troughs 21 and UV radiation units 22 and 44 are located, the belt 14 is directed over roller 16, under roller 18, and over roller 20, providing down and up movement of the belt 14 so that the belt passes under UV radiation unit 22 while the workpieces 24 pass over the UV radiation unit 22. The UV radiation unit is in close proximity to and provides disinfecting radiation treatment to the lower roller 18, the segment of the belt 14 that is passing between roller 16 and roller 18, and the segment of the belt 14 that is passing between roller 18 and roller 20. This offers improved disinfection of the belt 14 by allowing the lower UV radiation units 2 to irradiate the entire surface of the belt 14 without workpieces 24 blocking large portions of the belt 14 surface.

When the belt 14 moves a workpiece 24 over a trough 21, the UV radiation unit 22 in that trough 21 provides disinfecting radiation treatment to the underside or lower surfaces of the workpiece 24. Because a point on the belt 14 will travel a greater distance than an adjacent point on the underside of a workpiece 24 as the belt 14 and workpiece 24 move past the troughs 21, there will be a slight relocation or movement of the workpiece 24 relative to the belt 14 as the belt 14 and workpiece 24 move past the troughs 21. This relocation or movement of the workpieces 24 relative to the belt 14 contributes to improved belt 14 disinfection by exposing different areas of the belt 14 to radiation from the upper or side UV radiation units 44. If upper or side radiation units 44 are used, the combination of treatment from the lower units 22 and upper units 44 allows for 360 degree treatment of the workpieces 24.

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, while the treatment unit 22 discussed in the preferred embodiment is a UV radiation unit 22, it is understood that the system 10 may be used in connection with any number of different kinds or types of treatments, including but not limited such widely varying treatments as painting, washing, seasoning, drying, and countless other treatments. Also, any number of troughs 21 may be formed, and the troughs 21 may take any number of different shapes, sizes, and configurations. Further, although it is preferred to use upper or side UV radiation units 44 to provide 360 degree treatment, it is understood that such units 44 need not be used. Further still, although it is preferred to use the lower UV radiation units 22, it is understood that such units 22 need not be used. 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.

Claims

What is claimed is:

1. A method, comprising:

(a) placing a workpiece on a belt; and

(b) conveying said workpiece so that a treatment unit comes between said workpiece and said belt.

2. The method of claim 1, wherein step (b) comprises: conveying said workpiece so that said treatment unit comes between said workpiece and said belt, said workpiece passing above said treatment unit and said belt passing below said treatment unit.

3. The method of claim 1 , wherein step (b) comprises: conveying said workpiece so that said treatment unit comes between said workpiece and said belt, said treatment unit comprising a radiation unit.

4. The method of claim 1, wherein step (b) comprises: conveying said workpiece so that said treatment unit comes between said workpiece and said belt, said treatment unit comprising a UV radiation unit.

5. The method of claim 1, further comprising: providing a second treatment unit, said second unit being disposed so that said workpiece passes between said first treatment unit and said second treatment unit.

6. The method of claim 1, wherein step (a) comprises: placing said workpiece on said belt, said workpiece being selected from the group consisting of food products and surfaces associated with food processing.

7. The method of claim 1 , wherein said treatment unit is selected from the group consisting of radiating, painting, washing, seasoning, and drying units.

8. A method, comprising: (a) providing first, second, and third rollers; a top surface of said second roller being disposed lower than top surfaces of said first and third rollers;

(b) passing a belt over said first roller, then under said second roller, and then over said third roller;

(c) placing a workpiece on said belt; and (d) moving said workpiece past said first, second, and third rollers.

9. The method of claim 8, further comprising irradiating said belt and said workpiece on said belt.

10. The method of claim 8, further comprising irradiating an underside of said workpiece as said workpiece moves past said second roller.

11. The method of claim 10, further comprising irradiating an upper surface of said belt as said belt moves from said first roller to said second roller.

12. The method of claim 8, wherein: before said workpiece passes said first roller, a first location on said workpiece is in contact with a first location on said belt; as said first location on said workpiece passes said second roller, said first location on said workpiece is not in contact with said belt; and after said first location on said workpiece passes said third roller, said first location on said workpiece is in contact with said belt at a location other than said first location on said belt.

13. The method of claim 8, wherein: said first roller is positioned a first distance from said third roller; and said workpiece has at least one dimension having a length that is greater than approximately twice said first distance.

14. The method of claim 8, further comprising: after passing said belt over said third roller, passing said belt under a fourth roller and then over a fifth roller; and moving said workpiece past said fourth and fifth rollers

15. A combination, comprising: a plurality of rollers; a belt operably connected to said plurality of rollers to travel a path, said path including a first trough section; and a first treatment unit disposed in said first trough section of said belt, said first treatment unit being disposed in said first trough section so that a workpiece traveling on said belt past said first trough section passes above said first treatment unit.

16. The combination of claim 15, wherein said first treatment unit comprises a radiation unit.

17. The combination of claim 15, wherein said first treatment unit comprises a first UV radiation unit.

18. The combination of claim 17, further comprising a second UV radiation unit, said second UV radiation unit being disposed so that said belt and said workpiece pass under said second UV radiation unit.

19. The combination of claim 15 wherein said path further comprises a second trough section, and further comprising a second treatment unit disposed in said second trough section of said belt, said second treatment unit being disposed in said second trough section so that said workpiece traveling on said belt past said second trough section passes above said second treatment unit.

20. The combination of claim 15, wherein: said plurality of rollers comprises first, second, and third rollers, a top surface of said second roller being disposed lower than top surfaces of said first and third rollers; said belt passing over said first roller, under said second roller, and over said third roller to form said first trough section.