PRIORITY CLAIM
This application is a continuation from U.S. application Ser. No. 11/383,103, filed May 12, 2006, now U.S. Pat. No. 7,275,982.
FIELD OF THE INVENTION
This invention relates generally to conveyor belts and, more specifically, to cleaning systems for conveyor belts.
BACKGROUND OF THE INVENTION
Meat processing factories must be kept extremely clean in order to ensure a safe, clean final product. The United States Department of Agriculture (USDA) strictly enforces regulations requiring meat-processing facilities to maintain proper cleanliness. On-site inspectors will often verify compliance by evaluating both the presence of microbes and the aesthetic appearance of a plant.
In the typical prior plant, conveyor belts and tools are cleaned periodically. In such plants, the entire plant is often shut down in order to thoroughly clean. However, in the periods between cleanings, grease and other soiling materials are allowed to collect and become compacted on the equipment, particularly in recesses, such as surface scratches and the joints between members forming the equipment. This collection of soil and grease is extremely unsanitary and degrades the aesthetic appearance of the plant. Plant operators therefore risk being reprimanded, fined, or shut down by the on-site USDA inspector. Furthermore, the longer the grease and soil is allowed to remain on the equipment, the more time and effort is required to remove it. Typically, the use of chemical solvents and hot water is required. These solvents are typically unsafe for human consumption and therefore equipment must be thoroughly rinsed before meat products may contact it.
In view of the foregoing, it would be an advancement in the art to provide a system allowing uninterrupted operation of a meat processing facility for extended periods while still maintaining a low microbial count and good aesthetics, without the use of hazardous chemicals.
SUMMARY OF THE INVENTION
A conveyor cleaning system is disclosed enabling continuous operation of meat processing equipment without the use of chemical solvents. In one embodiment, a conveyor system has a treating region and a processing region. A distributor positioned across the treating region deposits a film of ozonated water on the conveyor belt. In the processing region, the conveyor belt is exposed to soiling agents such as grease and other animal matter.
A high-pressure rinser may also be positioned over the treating section such that the distributor is positioned between the high-pressure rinser and the processing region. The rinser removes grease and soil prior to deposition of a fresh layer of ozonated water on the conveyor belt.
Ozonated water may be generated by a system including first and second tanks. The first tank is filled with ozone gas and water. After a predetermined time, such as one minute, undissolved ozone gas is released. The contents of the first tank are then transferred to a second tank along with more ozone gas. After again waiting a predetermined time period, such as one minute, undissolved ozone gas is released from the second tank. The contents of the second tank may then be used to coat the conveyor belt and for other purposes.
Preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to
The distributor 14 may be embodied as a sprayer 24 having multiple heads 26 for spraying ozonated water across substantially the entire width of the conveyor belt 12. In the illustrated embodiment, the sprayer 24 includes heads 26 emitting a jet of water from 10 to 110 degrees wide at a rate of from 0.25 to 5 gallons per minute (gpm). The spray patterns of the heads 26 may overlap to ensure complete coverage. The heads 26 are typically located from 2 to 12 inches from the surface of the conveyor belt 12.
The ozonated water used typically has a temperature from 32 to 100 degrees F. The concentration of ozone within the ozonated water is chosen such that off-gas from the nozzles remains below safety thresholds. In the illustrated embodiment, at the point of impact with the conveyor belt 12, the ozonated water typically has an ozone concentration of from 1.8 to 3.5 parts per million (ppm). The pressure of the ozonated water is typically low to reduce the amount of off-gassing. Typical pressures used include from 10 to 110 psi.
Referring to
This advantageous breaking down of grease prior to compaction or drying is accomplished without the use of solvents or other agents that are unsafe for human consumption. Ozone rapidly breaks down into oxygen, leaving no unsafe residue. Furthermore, only a thin film of ozonated water remains on the belt 12 as it enters the processing region 20. Workers are therefore only subject to insignificant amounts of ozone.
The grease and soil broken down by the ozonated water is easily rinsed away in the treating region 18 by the distributor 14 or a distinct rinsing sprayer 34. The rinsing sprayer 34 may direct a high-pressure jet of non-ozonated water at the conveyor belt 12 preparatory for the deposition of ozonated water by the distributor 14. The rinsing sprayer 34 may spray water at pressures from 100 to 1000 psi. Inasmuch as the water emitted from the rinsing sprayer 34 is non-ozonated the jet of water may be at a much higher pressure to more effectively remove grease and soil without risk of off-gassing. In order to reduce off-gassing, the spray pattern from the distributor 14 preferably will not overlap that of the high-pressure rinsing sprayer 34.
The above system may be used to treat other equipment in the meat processing industry, such as slicers, saws, and the like.
The conveyor treating system 10 may be used to perform the method 36 of
The systems and methods disclosed above enable an 80 to 100% reduction in sanitation chemicals used in a typical meat processing plant. They also reduce by 80 to 100% the amount of hot water required for sanitation. The labor required to sanitize the meat processing plant has also been reduced by 50%.
Furthermore, the system disclosed is more effective than conventional systems. Surfaces treated as described above have a 50% lower bacteria count. Continuous operation of the processing plant is also enabled inasmuch as grease and soil is not allowed to compact on equipment. Plants treated as described above may be safely operated 24 hours a day under USDA supervision. Inasmuch as the conveyor belt 12, or other equipment, is constantly cleaned, degradation of aesthetics between cleanings is significantly reduced.
Ozonated water for use in the conveyor treating system 10 may be produced using the generating system of
Ozone from the ozone generator 52 is fed into a tank 54 along with non-ozonated water. The ozone may be fed into an inlet pipe 56 conducting water to the tank 54. Alternatively, the ozone and water may enter the first tank 54 through distinct openings. In order to avoid excessive ozone levels, ozone left undissolved after a predetermined period is released, such as through a release valve 58. In one preferred embodiment, undissolved ozone is released after from 0.5 to 1.5 minutes. In another preferred embodiment, undissolved ozone is released after one minute.
Ozonated water from the first tank may be emptied into a second tank 60. Ozone may also be injected into the second tank 60, whether through a distinct inlet or through an inlet tube 62 connecting the second tank 60 to the first tank 54. As with the first tank 54, undissolved ozone is released after a predetermined period by means of a release valve 64. In one preferred embodiment, undissolved ozone is released after from 0.5 to 1.5 minutes. In another preferred embodiment, undissolved ozone is released after one minute. The ozonated water in the second tank 60 is then used for purposes such as coating a conveyor belt 12.
A controller 66 may control the flow of fluid between the components of the ozone generating system. Electronically controlled valves 68 and pumps 70 controlled by the controller 66 cause the fluid to flow according to the method described above.
In some methods of use, ozonated water in the second tank 60 is used while water in the first tank 54 is being exposed to ozone gas. In some embodiments, multiple generating systems are used, such that while ozonated water is produced in one system it is being used in another.
While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.