Air sanitation apparatus for food processing tanks having air agitation piping and methods thereof

Abstract

An air sanitation apparatus capable of providing an antimicrobial agent in the form of a gas or mist into the air lines that feed into a processing tank for air agitation of the contents in the processing tank, the air sanitation apparatus capable of being operably coupled to an air supply header that uses a plurality of air supply tubes connecting the air supply header. The source of compressed air passing through the air sanitation apparatus having a microbial load decreased using photohydroionization and the antimicrobial agent.

Claims

1. A processing tank sanitation system, comprising: a compressed air header operably connected to a compressed air supply, wherein the air header includes an in-line air sanitation apparatus located upstream of a plurality of air agitation tubes operably connected to a processing tank, the air agitation tubes spaced apart along a longitudinal length of the processing tank; wherein the air sanitation apparatus includes a housing having a compressed air inlet and a sanitizing compressed air outlet located downstream of the compressed air inlet, an inlet coupling operably connecting the compressed air inlet to the compressed air header, an outlet coupling operably connecting the sanitizing compressed air outlet to the compressed air header, a UV light source and a vaporizing means located within the housing, the vaporizing means in fluid connection with a compressed air source and a liquid antimicrobial agent source, the compressed air source and the liquid antimicrobial agent source capable of being fed into the vaporizing means to provide the liquid antimicrobial agent in the form of an antimicrobial aerosol to mix with the compressed air supply and form a seeded compressed air stream upstream of the UV light source, wherein the seeded compressed air stream is exposed to the UV light source generating reactive oxygen species to create a sanitizing compressed air stream, the sanitizing compressed air stream having a least a portion of the antimicrobial aerosol; and the sanitizing compressed air stream exiting the air sanitation apparatus via the sanitizing compressed air outlet and supplied to the processing tank through each of the plurality of air agitation tubes such that sparging bubbles of the sanitizing compressed air stream agitate a chemical intervention solution within the processing tank; wherein the antimicrobial aerosol does not interfere with the chemical intervention solution within the processing tank for processing a food product.

2. The processing tank sanitation system of claim 1, wherein at least one UV light source comprises a photohydroionization cell.

3. The processing tank sanitation system of claim 1, further comprising an air distributor located within the housing of the air sanitation apparatus proximate to the compressed air inlet and upstream to at least one UV light source.

4. The processing tank sanitation system of claim 1, further comprising two or more UV light sources, wherein a catalyst surface is located proximate each of the two or more UV light sources.

5. The processing tank sanitation of claim 1, wherein the at least one UV light source contains one or more bands that wrap around the outer surface of the UV light source, wherein the catalyst surface is located on at least one of the bands.

6. The processing tank sanitation system of claim 1, wherein the at least one UV light source contains one or more longitudinal strips that run the length of the UV light source, wherein the catalyst surface is located on at least one of the longitudinal strips.

7. The processing tank sanitation system of claim 1, wherein the catalyst surface further comprises a desiccant for absorbing water from the air that is flowing through the air sanitation apparatus.

8. The processing tank sanitation system of claim 1, the apparatus comprising at least two UV light sources configured generally parallel to each other within the air sanitation apparatus.

9. The processing tank sanitation system of claim 1, the apparatus comprising at least two UV light sources configured generally perpendicular to each other within the air sanitation apparatus.

10. The processing tank sanitation system of claim 1, the apparatus comprising at least two UV light sources, wherein the catalyst surface is located between two adjacent UV light sources.

11. The processing tank sanitation system of claim 10, the apparatus comprising a panel located between the two adjacent UV light sources, wherein the catalyst surface is provided on the panel.

12. The processing tank sanitation system of claim 11, wherein the panel comprising the catalyst surface is capable of being removed from the housing and replaced with a different panel.

13. The processing tank sanitation system of claim 1, wherein the liquid antimicrobial agent comprising hydrogen peroxide or a peroxycarboxylic acid.

14. The processing tank sanitation system of claim 13, wherein the liquid antimicrobial agent comprises at least one peroxycarboxylic acid having 2-18 carbon atoms chosen from peroxyformic acid, peroxypropionic acid, peroxyacetic acid, peroxybutanoic acid, peroxypentanoic acid, peroxyhexanoic acid, peroxyheptanoic acid, peroxyoctanoic acid, peroxynonanoic acid, peroxydecanoic acid, peroxyundecanoic acid, peroxydodecanoic acid, peroxylactic acid, peroxymaleic acid, peroxyascorbic acid, peroxyhydroxyacetic acid, peroxyoxalic acid, peroxymalonic acid, peroxysuccinic acid, peroxyglutaric acid, peroxyadipic acid, peroxypimelic acid, peroxysubric acid, and mixtures thereof.

15. The processing tank sanitation system of claim 13, wherein the liquid antimicrobial agent comprises an equilibrium peroxycarboxylic acid or a pH modified peroxycarboxylic acid, the equilibrium peroxycarboxylic acid preferably having a pH above about 3.0 and below about 7.0.

16. The processing tank sanitation system of claim 13, wherein the liquid antimicrobial agent is atomized or nebulized into the compressed air supply in the form of a mist or gas having about 0.5 to about 10 micron droplets.

17. The processing tank sanitation system of claim 1, wherein the processing tank is a chiller processing tank for poultry processing.

18. The processing tank sanitation system of claim 1, wherein the liquid antimicrobial agent comprises peroxyacetic acid.

19. The processing tank sanitation system of claim 1, wherein the liquid antimicrobial agent comprises peroxylactic acid.

20. The processing tank sanitation system of claim 1, wherein the liquid antimicrobial agent is configured to be fed into the vaporizing means at a consumption rate of about 0.5 Liters per minute to about 3.0 Liters per minute.

21. The processing tank sanitation system of claim 1, wherein the liquid antimicrobial agent is configured to be fed into the vaporizing means at a flow rate of about 2 mL/hour and about 5 mL/hour.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1A is a side view of a representative prior art processing tank, particularly a chiller tank used for poultry processing, wherein compressed air is supplied to a compressed air supply header, the compressed air supply header feeding a plurality of tubes spaced apart along the operational length of the processing tank, each of the plurality of tubes operably coupled to a bottom portion of the processing tank, such that compressed air is supplied from each of the plurality of tubes into the interior volume of the processing tank to agitate the liquid contents of the processing tank during normal operation.

(2) FIG. 1B is a cross-sectional view of the representative prior art processing tank of FIG. 1A, further illustrating compressed air being supplied from a compressed air supply header located on each side of the processing tank to a tube that is operably coupled to a bottom portion of the processing tank, such that compressed air is supplied from each of the plurality of tubes into the interior volume of the processing tank to agitate the liquid contents of the processing tank during normal operation.

(3) FIG. 2A is a side view of an air sanitation apparatus according to certain embodiments of the present invention, the air sanitation apparatus inserted in the compressed air supply line of a processing tank, particularly a chiller tank used for poultry processing, wherein sanitized, compressed air is supplied to a compressed air supply header feeding a plurality of tubes spaced apart along the operational length of the processing tank, each of the plurality of tubes operably coupled to a bottom portion of the processing tank, such that the sanitized, compressed air is supplied from each of the plurality of tubes into the interior volume of the processing tank to agitate the liquid contents of the processing tank during normal operation.

(4) FIG. 2B is a cross-sectional view of the processing tank of FIG. 2B, further illustrating sanitized, compressed air being supplied from a compressed air supply header located on each side of the processing tank to a tube that is operably coupled to a bottom portion of the processing tank, such that the sanitized, compressed air is supplied from each of the plurality of tubes into the interior volume of the processing tank to agitate the contents of the processing tank during normal operation.

(5) FIG. 3 is a partial cross-sectional view of an air sanitation apparatus according to certain embodiments of the present invention.

(6) FIG. 4 is a partial cross-sectional view of an air sanitation apparatus according to certain embodiments of the present invention.

(7) FIG. 5 is a partial cross-sectional view of an air sanitation apparatus according to certain embodiments of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

(8) Referring generally now to the figures, particularly FIGS. 1A and 1B, is provided a processing tank 10 of the prior art. The processing tank 10 having a product infeed 12 and a product outlet 14, whereby the processing tank 10 contains a bath 40 filled to a desired processing level 38 with a processing liquid, such that the product can undergo any soaking, dipping, quenching, rinsing, washing, cooling, heating, or any other processing in which a product intended for human consumption is processed. During such processing operations, the bath 40 in the processing tank 10 may be stirred by air agitation, which comprises providing sparging bubbles 36 within the bath 40. The air used for air agitation being provided to the processing tank 10 from a compressed air header 20 by the use of a plurality of air agitation tubes 30 that are spaced apart along the longitudinal length of the processing tank 10, the compressed air header 20 being operably connected to a compressed air supply 22, which can be located in another room 25, such as a mechanical room, where the air is unfiltered for microbial loads. The compressed air header 20 can be split into two or more runs, such as shown in FIG. 1B whereby the compressed air header 20 extends the longitudinal length on both sides of the processing tank 10. As illustrated in FIGS. 1A and 1B, the plurality of air supply tubes 30 are operably connected on a proximate end 32 to one of the compressed air headers 20 and to the processing tank 10 on a distal end 34, such that the compressed air flows from the respective compressed air header 20 into the plurality of air agitation tubes 30 and into the processing tank 10 to provide sparging bubbles 36 for air agitation of the bath 40 contained within the processing tank 10.

(9) Referring now to FIGS. 2A and 2B, an air sanitation apparatus 100 of the present invention can be provided in line of the compressed air that is supplied to the processing tank 10. For example, the air sanitation apparatus 100 of the present invention can be operably coupled to a compressed air header 20, such that air flows through the air sanitation apparatus 100 prior to being provided to the processing tank 10. In some aspects, the air sanitation apparatus 100 is provided in line of the compressed air header 20 prior to the compressed air header 20 splitting into two or more compressed air header sections 20, each of the sections 20 substantially traversing a longitudinal length of the processing tank 10. In some other aspects, an air sanitation apparatus 100 can be provided in line of the compressed air header 20 after the compressed air header 20 is split into two sections traversing the longitudinal length of the processing tank 10, such that an air sanitation apparatus 100 can be provided on each section of the compressed air header 20, or only on one such section. The air sanitation apparatus 100 providing an antimicrobial agent in the form of a mist or gas in the compressed air, which is then introduced into the processing tank 10 during the air agitation process.

(10) In some aspects, the bath 40 comprises a chemical intervention solution chosen from chlorine, bromine, cetylpyridinium chloride (CPC), an organic acid, a peroxycarboxylic acid, trisodium phosphate (TSP), acidified sodium chlorite, and chlorine dioxide. The antimicrobial agent is preferably chosen such that it does not interfere with the chemical intervention solution. In some other aspects, the antimicrobial agent may be chosen to further enhance or extend the effectiveness of the bath 40 containing the chemical intervention solution.

(11) Referring now to FIGS. 3-5, the air sanitation apparatus 100 of the present invention contains a housing 102 having an air inlet 104 that may have an air inlet coupling 106 to operably connect the air sanitation apparatus 100 to an upstream section of the compressed air header 20 and an air outlet 108 that may have an air outlet coupling 110 to operably connect the air sanitation apparatus 100 to a downstream section of the compressed air header 20.

(12) Within the housing 102 is comprised one or more UV light sources 132 and a catalyst source, the catalyst source providing a catalyst surface located between the air inlet 104 and air outlet 108, such that the source of compressed air passing through the air sanitation apparatus 100 is exposed to the radiation of the one or more UV light sources 132. The one or more UV light sources 132 being powered by a UV light power supply 130. In some aspects, the UV light sources comprise one or more photohydroionization cells.

(13) While the UV light sources 132 are shown in a generally parallel configuration, the UV light sources may also be provided in an intersecting or criss-cross configuration with respect to each other within the housing. In some aspects, the catalyst surface is positioned in close proximity to the one or more UV light sources 132 emitting energy at a specific wavelengths set to maximize the process effect. In some aspects, the one or more UV light sources 132 contain bands 133 that wrap around the outer surface of the UV light source and/or longitudinal strips 134 that run the length of the UV light source, wherein the catalyst surface is located on the bands 133 and/or longitudinal strips 134 in close proximity to the respective UV light source 132.

(14) An air distributor 112 can also be provided within the housing 102 proximate the air inlet 104 and located upstream in the compressed air flow prior to the one or more UV light sources 132 and the catalyst surface. The air distributor 112 can comprise a baffle, such as an S-shaped or V-shaped baffle, to capture and remove unwanted contaminants in the compressed air flow, such as oil or grease particulate emissions.

(15) Located between the one or more UV light sources 132 and the air inlet 104 is a means 120 for producing the antimicrobial agent in the form of a mist or gas, such as an atomizer or nebulizer, which is fed a source of compressed air 116 and a source of an antimicrobial agent 118. In certain aspects, means 120 for producing the antimicrobial agent in the form of a mist or gas is located between the air distributor 112 and the one or more UV light sources 132 and the catalyst surface. The source of compressed air 116 and the source of an antimicrobial agent 118 are fed into means 120, such as an atomizer or nebulizer, to continually provide the antimicrobial agent in the form of a mist or gas within the air flow prior to the air flow being exposed to the radiation of the UV light sources 132 and the catalyst surface. In some aspects, the air sanitation apparatus 100 continually treats the source of air by atomizing or nebulizing the source of the antimicrobial agent upstream from the UV light sources 132, which in some aspects comprise one or more photohydroionization (PHI) cells.

(16) The catalyst surface is preferably positioned in close proximity to the one or more UV light sources 132 emitting energy at one or more specific wavelengths set to maximize the process effect. In some aspects, the one or more UV light sources 132 contain bands 133 that wrap around the outer surface of the UV light source 132 and/or longitudinal strips 134 that run the length of the UV light source 132, wherein the catalyst surface is deposited or otherwise located on the bands 133 and/or longitudinal strips 134.

(17) During normal operation, the liquid antimicrobial agent is preferably formed into a mist or gas such that the mist or gas of the antimicrobial agent is provided in about 0.5 to about 10 micron droplets, in some aspects about 1 to about 9 micron droplets, in some aspects about 2 to about 8 micron droplets, and in some other aspects about 4 to about 7 micron droplets, with one of ordinary skill in the art appreciating that am atomizer/nebulizer can provide desired size droplets of the antimicrobial agent.

(18) As shown in FIG. 3, the UV light sources 132 may only traverse a portion of the interior width of the housing 102. In such configurations, an air deflector 114 may be utilized to direct the air flow, such that the air flow passes over, under and/or around the area of the UV light sources 132. In some other aspects, as shown in FIGS. 4 and 5, the one or more UV light sources 132 extend substantially the entire width of the housing 102, such that the source of compressed air passing through the air sanitation apparatus 100 is exposed to the one or more UV light sources 132.

(19) In certain aspects, the catalyst surface can be located between two adjacent UV light sources 132. In some aspects, as shown in FIG. 5, the catalyst surface can be provided on one or more panels 136 that can be inserted between two adjacent UV light sources 132, each panel 136 capable of being removed from the housing 102 and replaced with a different panel 136, depending upon the catalyst surface reaching its lifetime, becoming contaminated, being replaced with a different catalyst, or the like. In some aspects, the panel 136 having the catalyst surface has a plurality of apertures or comprises an air distributor, such that the air flow can pass through the panel 136 during normal operation.

(20) Prior to being fed into the means 120 for producing the antimicrobial agent in the form of a mist or gas, the source of the antimicrobial agent 118 is a liquid. In some aspects, the liquid antimicrobial agent preferably comprises hydrogen peroxide. In some other aspects, the liquid antimicrobial agent preferably comprises a peroxycarboxylic acid. In still some other aspects, the liquid antimicrobial agent comprises chlorine, bromine, cetylpyridinium chloride (CPC), an organic acid, a peroxycarboxylic acid, hydrogen peroxide, trisodium phosphate, acidified sodium chlorite, chlorine dioxide, and/or mixtures thereof.

(21) In some aspects, the liquid antimicrobial agent comprises hydrogen peroxide. By providing micron-sized droplets of hydrogen peroxide in the compressed air source, there are more available free radical hydroxyls to perform the desired work of sanitizing the compressed air stream. In certain aspects, the hydrogen peroxide is provided at a concentration in a range of about 3% to about 50%, in some other aspects about 5% to about 35%, and in some other aspects about 5% to about 10%.

(22) In some aspects, the liquid antimicrobial agent comprises at least one peroxycarboxylic acid having 2-18 carbon atoms. In some aspects, the peroxycarboxylic acid solution is chosen from peroxyformic acid, peroxypropionic acid, peroxyacetic acid, peroxybutanoic acid, peroxypentanoic acid, peroxyhexanoic acid, peroxyheptanoic acid, peroxyoctanoic acid, peroxynonanoic acid, peroxydecanoic acid, peroxyundecanoic acid, peroxydodecanoic acid, peroxylactic acid, peroxymaleic acid, peroxyascorbic acid, peroxyhydroxyacetic acid, peroxyoxalic acid, peroxymalonic acid, peroxysuccinic acid, peroxyglutaric acid, peroxyadipic acid, peroxypimelic acid, peroxysubric acid, and mixtures thereof. Preferably, the antimicrobial agent comprises an equilibrium peroxycarboxylic acid or a pH modified peroxycarboxylic acid.

(23) In some aspects, the equilibrium peroxycarboxylic acid preferably has a pH above about 3.0 and below about 7.0, in some aspects about 3.5 to about 5.5, and in some other aspects about 3.5 to about 5.0, although subranges within these ranges is contemplated. In some preferred aspects, the equilibrium peroxycarboxylic acid comprises peroxyacetic acid.

(24) In some aspects, the pH modified peroxycarboxylic acid preferably has a pH above about 7.0 and below about 10.0, in certain aspects a pH range of about 7.0 to about 9.5, and in some other aspects a pH range of about 7.5 to about 9.0, although subranges within these ranges is contemplated. The pH modified peroxycarboxylic acid can be prepared by combining a peroxycarboxylic acid solution, such as a peroxyacetic acid solution, with one or more buffering agents chosen from sodium hydroxide, potassium hydroxide, the sodium salt of carbonic acid, the potassium salt of carbonic acid, phosphoric acid, silicic acid or mixtures thereof, in a quantity that is necessary to bring the solution to said pH range One of ordinary skill in the art will appreciate that other alkalizing chemistries approved for direct food contact may also be used, whether alone or in combination with any of the foregoing buffering agents. The quantity of the buffering agent in a buffered peroxycarboxylic acid solution will generally be in the range of about 0.01% to about 10% by volume of the total solution, but other volumes of the buffering agent may be utilized depending upon various parameters, such as local water condition, including pH, hardness and conductivity. In some preferred aspects, the pH modified peroxycarboxylic acid comprises peroxyacetic acid.

(25) The catalyst surface preferably substantially surrounds the UV light source 132. The ultraviolet light emitted from at least one UV light source 132 includes ultraviolet light energy between about 10 nm and about 400 nm, in some other aspects about 50 nm to about 350 nm, and in some other aspects about 100 nm to about 300 nm. In some aspects, the catalyst surface comprises titanium dioxide. In some other aspects, the catalyst surface comprises a transition metal oxide, such as titanium dioxide. In some aspects, the catalyst surface can comprise two or more transition metal oxides, or transition metal alloy oxides, such as titanium alloyed with iron, aluminium, vanadium, and molybdenum. In some aspects, the catalyst surface can also comprise at least one of the following metallic compounds: silver; copper; and rhodium, if not all three compounds. In some other aspects, the catalyst surface contains silver ions, such as silver dihydrogen salts.

(26) In some aspects, the air sanitation apparatus 100 utilizes a UV/H2O2 Advanced Oxidation Process (AOP). Oxidizers created during advanced oxidation processes are much more effective than traditional oxidants at reacting with compounds such as microbes, odor causing chemicals, and other inorganic and organic chemicals. Oxidants that may be created in an advanced oxidation process are considerably stronger than typical cleaning agents such as chlorine. These oxidants, generally referred to as advanced oxidation product or AOP, include Ozone, Hydroxyl Radicals, Hydro Peroxides, Ozonide Ions, Hydroxides, and Super Oxide ions. All of these compounds are either used during or are produced as a result of advanced oxidation processes. With the process of the present invention, not only is the catalyst surface active, but also is the air space between the catalyst surface and the UV light source 132.

(27) Generally, advanced oxidation product will react with compounds that typically will not react with other common oxidants. An example of one of the strong oxidizers created by advanced oxidation processes is the Hydroxyl Radical. The Hydroxyl Radical (OH) is very unstable, thereby making it very aggressive for a free radical. One method that creates the Hydroxyl or free radical is when ozone and water react with ultraviolet light energy and protolysis occurs. Although the Hydroxyl Radicals are very short lived, they have a higher oxidation potential than ozone, chlorine, or hydrogen peroxide, and their unstable nature increases their reaction speed. A strong benefit of advanced oxidation is the end product of carbon dioxide and water.

(28) Water found in the processing plant air can be drawn through the air sanitization apparatus of the present invention, where the water is absorbed by a desiccant material. Water can also be introduced into the air sanitization apparatus by the liquid antimicrobial agent that is atomized/nebulized. Once absorbed, the water is brought into contact with the catalyst and exposed to the UV radiation. When this moisture is exposed to UV radiation, and allowed ample time to absorb the UV radiation while retained on the descant material, several processes are initiated.

(29) While in the presence of ultraviolet (UV) light, the H.sub.2O is broken into hydroxyl radicals (.OH). The oxidation potential of a hydroxyl radical (2.8V) is much greater than ozone (2.07V) and chlorine (1.39V) and thus has the capability of oxidizing a variety of organic and inorganic contaminants. The recombination of the hydroxyl and ozone free radicals in the presence of the catalyst, promotes the development of hydrogen peroxide. UV light catalyzes the dissociation of hydrogen peroxide into hydroxyl radicals through chain reactions or the hydrogen peroxide is entrained into the air stream where it destroys bacteria and fungus. This in combination with the dislodged free radicals and the UV radiation means the sanitation system utilizes four different bacteria and/or fungi killing agents in a very safe and effective way.

(30) The combination of safe low level ozone (O.sub.3), hydroxyls and a broad spectrum UV light enhanced by a catalyst containing a hydrated quad-metallic compound produces an advanced oxidation reaction. This process also produces hydro-peroxides, super oxide ions, ozonide ions and hydroxides. By providing the proper UV light wavelength, in combination with a triple function, low maintenance unit, the PHI Cell provides safe hydro-peroxides, super oxide ions, ozonide ions and hydroxides to purify the air. PHI is not a typical UV light source placed in an air stream, and it is not a high maintenance open electrode ozone generator.

(31) In some aspects, the air sanitation apparatus of the present invention utilizes the antimicrobial agent, such as hydrogen peroxide, to seed the incoming air prior to the PHI cell for a dramatically increase volume of free radical generation. For example, by providing ultra-small droplets of 10% H.sub.2O.sub.2 in the incoming air, there are more available free radical hydroxyls to perform the desired work of sanitizing the air stream and/or the food product within the processing tank 10. In some aspects, the specialized nebulizing injector provides about 0.5 to about 10 micron droplets, in some aspects about 1 to about 9 micron droplets, in some aspects about 2 to about 8 micron droplets, and in some other aspects about 4 to about 7 micron droplets of hydrogen peroxide on a continuous basis with the supply delivered to all units through on chemical delivery system positioned in a convenient location. One of ordinary skill in the art will appreciate that the nebulizing injector can provide different sized droplets of hydrogen peroxide depending upon the specific application.

(32) In some aspects, the hydrogen peroxide consumption rate is approximately 0.5 GPM Max with effective flows as low as 2 mL/hr depending on organic loading.

(33) In some other aspects, the liquid antimicrobial agent consumption rate through the means for producing the antimicrobial agent in the form of a mist or gas is approximately 1.9 Liters per minute with effective flow rates as low as 2 mL/hr, depending on organic loading. In some aspects, the liquid antimicrobial agent consumption rate is about 0.5 Liters per minute to about 3.0 Liters per minute. In some aspects, the effective flow is between about 2 mL/hr and about 5 mL/hr. One of ordinary skill in the art will appreciate that the consumption rate is dependent upon unit size, volume of air treated, and operating time per day, such that values outsides these ranges are contemplated.

(34) With the air sanitation apparatus of the present invention, micro-organisms can be reduced up to at least about 80%, in some aspects at least about 85%0% in some aspects at least about 90%, in some aspects at least about 95%, and in some other aspects at least about 99.99% in certain situations. Gases, VOCs and odors can also be reduced significantly, and the plant will contain ozonide ions, hydro-peroxides, super oxide ion and hydroxides which will provide continuous protection for the air as well as equipment without the use of temperamental and very problematic open electrode plasma or corona discharge ozone generation systems.