WO2024206679A2 - System and method for peracetic acid monitoring and adjustment in high ph solutions - Google Patents

Abstract

A system and method for adjusting a peroxycarboxylic acid are described. In an embodiment, the system comprises a process water source configured to carry process water; a valve configured to selectively place a source of a peroxy carboxylic acid in fluidic communication with the process water source; a first pump configured to pump an aliquot of the process water from the process water source to a testing location; a second pump in fluidic communication with a source of an acid and configured to pump a portion of the acid to the testing location in a combined flow with the aliquot; a peroxycarboxylic acid sensor positioned in the testing location and configured to generate a peroxy carboxylic acid signal based upon a concentration of the peroxy carboxylic acid in the combined flow; a pH sensor positioned in the testing location configured to generate a pH signal based on a pH of the combined flow.

Description

SYSTEM AND METHOD FOR PERACETIC ACID MONITORING AND ADJUSTMENT IN HIGH PH SOLUTIONS

CROSS-REFERENCE(S) TO RELATED APPLICATION S)

[0001] This application claims the benefit of U.S. Provisional Application No. 63/492,834, filed March 29, 2023, the entire contents of which are incorporated herein by reference.

BACKGROUND

[0002] Peracetic Acid (PAA) is widely used throughout the food processing industry as a processing aid. Its oxidative activity to control a range of broad-spectrum microbes and harmless dissociative properties make it well suited for the food industry. The synergistic effects of mixing other processing aids with PAA are becoming more prevalent. One such chemistry commonly combined with PAA alters the mildly acidic solution into an alkaline solution greater than pH 7.

[0003] Current conventional PAA sensor technology has difficulty operating in heavy organics, such as experienced in poultry processing environments, and alkaline conditions. The challenges of heavy organics and alkaline solutions make it difficult to apply automated systems to these areas of the processing industry. Attempts to address these challenges are met with routine cleaning of filters, blockages, loss of water flow and inaccuracy of readings due to alkaline pH. Because of the challenges, much of the industry has adopted manual, handheld titration methods, which are time-consuming, expensive, and come with greater risk of inaccuracy due to the requirement for human intervention.

SUMMARY

[0004] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0005] To address these and related challenges, the present disclosure provides systems and methods for monitoring and adjusting, such as continuously monitoring and adjusting, a peroxycarboxylic acid concentration.

[0006] In this regard, in an aspect, the present disclosure provides a system for adjusting and/or monitoring a peroxycarboxylic acid concentration or amount, such as in a continuous and/or automated manner. In an embodiment, the system comprises a process water source configured to carry process water; a valve configured to selectively place a source of a peroxy carboxylic acid in fluidic communication with the process water source; a first pump configured to pump an aliquot of the process water from the process water source to a testing location; a second pump in fluidic communication with a source of an acid and configured to pump a portion of the acid to the testing location in a combined flow with the aliquot; a peroxycarboxylic acid sensor positioned in the testing location and configured to generate a peroxycarboxylic acid signal based upon a concentration of the peroxycarboxylic acid in the combined flow; and a pH sensor positioned in the testing location configured to generate a pH signal based on a pH of the combined flow; a controller operatively coupled to the peroxycarboxylic acid sensor, the pH sensor, the first pump, the second pump, and the valve, the controller including logic that, when executed, causes the system to perform operations. In an embodiment, the operations include pumping, with the first pump, an aliquot of the process water to the testing location; pumping, with the second pump, acid from the source of the acid to the testing location; generating, with the pH sensor, the pH signal based upon the pH of the combined flow; generating, with the peroxycarboxylic acid sensor, the peroxycarboxylic acid signal based upon the concentration of the peroxycarboxylic acid of the combined flow; and operating the valve to provide an amount of the peroxycarboxylic acid to the process water source based upon the peroxycarboxylic acid signal.

[0007] In an embodiment, an amount of the acid pumped with the second pump is based upon the pH signal. In an embodiment, the controller further includes logic that, when executed, causes the system to perform operations including pumping, with the second pump, the acid into the combined flow when pH of the combined flow is greater than 6.

[0008] In an embodiment, the system further comprises a mixer configured to mix the aliquot and the acid of the combined flow to provide a mixed combined flow. In an embodiment, the mixer is positioned between the first pump and the testing location. In an embodiment, the mixer is configured to provide a substantially homogenous mixed combined flow.

[0009] In an embodiment, the system further comprises a sample port configured to expel a portion of the combined flow from the testing location.

[0010] In an embodiment, the combined flow is configured to release into the process water source after passing through the testing location. In an embodiment, the combined flow is configured to release into a drain after passing through the testing location.

[0011] In an embodiment, the peroxycarboxylic acid solution comprises peracetic acid (PAA).

[0012] In an embodiment, the valve is configured to selectively place a caustic source in fluidic communication with the process water source.

[0013] In an embodiment, the system further comprising a second valve configured to selectively place a caustic source in fluidic communication with the process water source.

[0014] In an embodiment, the acid has a pH of less than 1.

[0015] In an embodiment, the aliquot is not removed from an outflow of the process water source.

[0016] In an embodiment, the system further comprises a filter positioned between the process water source and the first pump, wherein the filter is configured to filter particles from the aliquot.

[0017] In an embodiment, the controller further includes logic that, when executed, causes the system to perform operations including continuously pumping, with the first pump, aliquots of the process water including the aliquot to the testing location during a duty cycle of the system.

[0018] In another aspect, the present disclosure provides a method for adjusting concentration of peroxycarboxylic acid in a process water source. In an embodiment, the method comprises pumping, with a first pump, an aliquot of process water from the process water source to a testing location downstream from the process water source; pumping, with a second pump, acid from a source of the acid to the testing location to provide a combined flow of the aliquot and the acid; measuring a pH of the combined flow; measuring the concentration of the peroxy carboxylic acid of the combined flow; operating a valve to provide an amount of peroxycarboxylic acid to the process water source based upon the concentration of the peroxycarboxylic acid.

[0019] In an embodiment, an amount of the acid pumped with the second pump is based upon the pH signal.

[0020] In an embodiment, pumping, with the second pump, occurs when the pH of the combined flow is greater than 6. [0021] In an embodiment, pumping, with the first pump, comprises continuously pumping, with the first pump, aliquots of the process water including the aliquot to the testing location during.

[0022] In an embodiment, measuring the pH of the combined flow comprises generating, with a pH sensor disposed in the testing location, a pH signal based upon a pH of the combined flow; measuring the concentration of the peroxycarboxylic acid of the combined flow comprises generating, with a peroxycarboxylic acid sensor disposed in the testing location, a peroxycarboxylic acid signal based upon the concentration of the peroxycarboxylic acid of the combined flow, and operating a valve to provide an amount of peroxycarboxylic acid to the process water source based upon the peroxy carboxylic acid signal.

[0023] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

DESCRIPTION OF THE DRAWINGS

[0024] The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

[0025] FIGURE 1 is a schematic illustration of a system in accordance with an embodiment of the present disclosure;

[0026] FIGURE 2 is a schematic illustration of another system in accordance with an embodiment of the present disclosure;

[0027] FIGURE 3 is a block diagram of a method in accordance with an embodiment of the present disclosure; and

[0028] FIGURE 4 is a schematic illustration of another system in accordance with an embodiment of the present disclosure;

[0029] FIGURES 5A-5C graphically illustrate peroxycarboxylic acid concentration in a combined flow over time as measured by a peroxy carboxylic acid sensor of a system according to an embodiment of the present disclosure; and [0030] FIGURE 6 graphically illustrates peroxycarboxylic acid concentration in a combined flow over time as measured by a peroxycarboxylic acid sensor of a system according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

[0031] While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.

[0032] Embodiments of an apparatus, machine-readable storage medium, and method for adjusting a concentration or an amount of a peroxy carboxylic acid are described herein. In the following description numerous specific details are set forth to provide a thorough understanding of the embodiments. One skilled in the relevant art will recognize, however, that the techniques described herein can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well- known structures, materials, or operations are not shown or described in detail to avoid obscuring certain aspects.

[0033] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. SYSTEMS

[0034] In an aspect, the present disclosure provides systems for monitoring and/or adjusting a concentration or amount of a peroxycarboxylic acid. In an embodiment, the system is configured for continuous and/or automated monitoring and/or adjusting of a concentration or amount of a peroxycarboxylic acid, such as may be performed without significant human intervention and without interruption over an extended period of time.

[0035] In this regard, attention is directed to FIGURE 1 in which a system 100 according to an embodiment of the present disclosure is illustrated. The system 100 is shown to include a process water source 102 configured to carry process water; and a valve 104 configured to selectively place a source of a peroxy carboxylic acid 106 in fluidic communication with the process water source 102. In the illustrated embodiment, the source of process water 102 is shown as a tank 102, such as a treatment tank 102. While a tank 102 is illustrated, it will be understood that other sources of process water 102 can be used and are within the scope of the present disclosure, such as a vessel, stream, pond, drain, and the like.

[0036] In an embodiment, the tank 102 is configured to process, such as to disinfect, a food product or foodstuff, such as but not limited to a poultry carcass. While poultry carcasses are discussed further herein, it will be understood that the source of process water 102 is not limited to a configuration for treating or disinfecting a poultry carcass and that other configurations are possible and within the scope of the present disclosure.

[0037] As used herein, “food products” and “foodstuffs”, which may be referred to interchangeably, refer to solid and liquid food products that are edible by humans or domesticated animals. Solid food products include but are not limited to meat products such as poultry products (e.g., chicken, duck, and turkey products), eggs, beef products, pork products, and seafood products (e.g., fish, shellfish, crustaceans, mollusks, echinoderms, seaweed). Solid food products also include produce products, for example, fruits, vegetables, algae, seeds, grains, sprouts, legumes, soy, and nuts. Solid food products also include dairy products such as hard, soft, and semi-soft cheeses. Liquid food products can include beverages (e.g., juices, soda), liquid dairy products (e.g., milk and cream), fermented beverages (e.g., beer and wine), and liquid feed ingredients and liquid feeds used as animal feed (e.g., fermented liquid feeds fed to farm livestock and poultry).

[0038] As above, the system 100 includes a valve 104 configured to selectively place a source of a peroxy carboxylic acid 106 in fluidic communication with the process water source 102. In this regard, the valve 104 is configured to introduce the peroxy carboxylic acid into the process water source 102, such as when a concentration or amount of the peroxy carboxylic acid in the tank 102 is below a predetermined or desirable level. The valve 104 can be any type of valve 104 configured to selectively provide fluidic access, such as through activation of the valve 104 between an open and a closed configuration. Examples of valves 104 within the scope of the present disclosure include but are not limited to hydraulic valves, pneumatic valves, manual valves, solenoid valves, and motor valves. While valves 104 are discussed further herein with respect to structures configured to selectively place the source of the peroxy carboxylic acid 106 in fluidic communication with the process water source 102, any structure or group of structures configured to perform such selective placement of the source of the peroxy carboxylic acid source 106 in fluidic communication with the process water source 102 are possible and within the scope of the present disclosure.

[0039] In an embodiment, the peroxycarboxylic is peracetic acid (PAA). While PAA is discussed further herein, it will be understood that other peroxy carboxylic acids are possible and within the scope of the present disclosure.

[0040] While peroxy carboxylic acids are described herein, other acids may be used with the systems 100 and 200 and methods, such as method 300, of the present disclosure. Such acids can be selected from, but should not be limited to citric acid, ascorbic acid, lactic acid, acetic acid, peracetic acid, formic acid, propionic acid, butyric acid, valeric acid, caproic acid, oxalic acid, malic acid, benzoic acid, carbonic acid, phenol, uric acid, taurine, p-toluenesulfonic acid, triflic acid, aminomethylphosphonic acid, and combinations thereof.

[0041] As shown, the system 100 also includes a first pump 108 configured to pump an aliquot of the process water from the process water source 102 to a testing location 110. In the illustrated embodiment, the first pump 108 is shown in direct fluidic communication with the source of process water 102. However, the first pump 108 can be separated from the process water source 102 by one or more valves.

[0042] In the illustrated embodiment, the first pump 108 does not pump the aliquot from an outflow 132 of the tank 102. As discussed below, the system 100 includes components, such as the second pump 112 and source of an acid 114, to reduce a pH of the aliquot. Reducing a pH of a total outflow 132 of the tank 102 would involve large amounts of reagents, i.e., acid, and, therefore, the first pump 108 is configured to pump an aliquot having a much smaller volume.

[0043] The first pump 108 is shown upstream of a testing location 110 and in between the process water source 102 and the testing location 110. In an embodiment, the first pump 108 is configured to pump an aliquot of the process water to the testing location 110 and, in some embodiments, through the testing location 110. In an embodiment, the first pump 108 is configured to pump many aliquots of the process water through a circuit, pipes, conduits, and the like, including the testing location 110. In an embodiment, the first pump 108 is configured to continuously pump process water through the testing location 110 such that the testing location 110 is exposed continuously to a plurality of aliquots of the process, such as to test the process water over time as its components and concentrations change.

[0044] As described herein, process water and other liquids are described as travelling from a starting point, such as the process water source 102, to an end point, such as returning to the process water source 102 in a loop or to a drain. In various embodiments, the present disclosure refers to upstream and downstream positions. In an embodiment, “upstream” refers to a position within the system, such as system 100, closer to a starting point and farther from an end point. Correspondingly, in an embodiment, “downstream” refers to a position closer to an end point and farther from a starting point. While fluid can pass through the system 100 in a loop, such as starting and ending at the process water source 102, closer and farther from an end point is determined as the fluid passes through the system 100 according to the general direction of flow through the system 100. As an example, and as described above, the first pump 108 is shown upstream of the testing location 110. As a further example, the first pump 108 is shown downstream of the process water source 102.

[0045] As used herein, an “aliquot” refers to a portion of the total volume of a fluid sample, e.g., process water, to be analyzed. In an embodiment, an aliquot comprises a volume of liquid including a portion of the process water flowing through a portion of the system 100 including the testing location 110. In an embodiment, the aliquot is defined, at least in part, as a volume of liquid, such as comprising process water, within the testing location 110, such as can be tested at any one time. In an embodiment, the system 100 is configured to pump, such as to pump continuously, a plurality of aliquots through the system 100. In an embodiment, the system 100 is configured to pump a plurality of concatenated aliquots, i.e., a plurality of immediately adjacent and connected aliquots, suitable for continuous measurement.

[0046] The system 100 is also shown to include a second pump 112 in fluidic communication with a source of an acid 114 and configured to pump a portion of the acid to the testing location 110 in a combined flow with the aliquot. In this regard, the outflow of the second pump 112 is shown to merge with an outflow of the first pump 108 upstream of the testing location 110 such that the outflows of the first pump 108 and the second pump 112 merge and/or mix to provide the combined flow.

[0047] By providing a combined flow comprising the aliquot of the process water and acid from the source of acid 106, a pH of the combined flow is reduced relative to that of the process water, i.e., the untreated process water. As discussed further herein, conventionally, certain process water including peroxycarboxylic acid has a pH above 7, which makes accurate peroxycarboxylic acid concentration measurement difficult or impossible with conventional sensors for peroxycarboxylic acid. By lowering the pH of the process water with the acid from the source of the acid, peroxycarboxylic acid concentration can be more accurately measured in the testing location 110.

[0048] In an embodiment, the acid in the source of an acid 114 is highly concentrated. In one example, the acid has a pH of less than 1. In an embodiment, the acid has a concentration of greater than 1 M. In an embodiment, the acid is a strong acid, such as a strong acid selected from hydrochloric acid, sulfuric acid, nitric acid, chloric acid, perchloric acid, hydrobromic acid, hydroiodic acid, and combinations thereof.

[0049] By having a highly concentrated and/or strong acid, a concentration of the aliquot, such as a peroxy carboxylic acid concentration in the aliquot, is not greatly affected by introducing the acid into the combined flow because relatively small volumes are used to reduce the pH of the aliquot to an appropriate level. In this regard, the aliquot is diluted less than if the aliquot had been treated with a weak and/or dilute acid.

[0050] In an embodiment, a concentration of the acid and a volume of acid introduced into the combined flow are known, such that a concentration of the peroxy carboxylic acid in the aliquot in the absence of the acid can be and/or is determined.

[0051] In the illustrated embodiment, the system 100 is shown to include a mixer 122 configured to mix the aliquot and the acid of the combined flow to provide a mixed combined flow. In an embodiment, the mixer 122 is positioned between the first pump 108 and the testing location 110. In this regard, in an embodiment, the mixer 122 is configured to provide a substantially homogenous mixed combined flow. By mixing the combined flow with the mixer 122, the testing location 110 receives a combined flow that is mixed and, therefore, more homogeneous, which can lead to a more accurate measurement. In particular, by mixing the aliquot of the process water with the acid, the pH of the aliquot is lowered and lowered more uniformly than without such mixing. As above, lowering a pH of a peroxycarboxylic acid solution, such as below a pH of 7, generally leads to a more accurate measurement of a concentration of the peroxycarboxylic acid in the aliquot and, by implication, the process water generally.

[0052] The mixer 122 can be any mixer 122 configured to mix the combined flow. In an embodiment, the mixer 122 is a herringbone mixer. In an embodiment, the mixer 122 is weir mixer. In an embodiment, the mixer 122 is selected from a herringbone mixer, zig-zag mixer, micro jet mixer, or micro-vortex mixer. In an embodiment, the mixer 122 is selected from a T-mixer, Y-mixer, or W-mixer. In an embodiment, the mixer 122 defines a plurality of flow paths configured to impart turbulence and non-laminar flow to the combined flow, thereby mixing the combined flow. In an embodiment, the mixer 122 comprises a motor attached to a propeller or other mixing structure configured to actively mix the combined flow.

[0053] As above, the system 100 includes a testing location 110 for testing an aliquot of the process water in the combined flow. In the illustrated embodiment, the testing location 110 is shown to include a peroxycarboxylic acid sensor 116 and a pH sensor 118. In an embodiment, the peroxycarboxylic acid sensor 116 is configured to generate a peroxycarboxylic acid signal based upon a concentration of the peroxycarboxylic acid in the combined flow. In an embodiment, the pH sensor 118 is configured to generate a pH signal based on a pH of the combined flow.

[0054] The testing location 110, including the pH sensor 118 and the peroxycarboxylic acid sensor 116, is shown operatively coupled to a controller 120. In the illustrated embodiment, the controller 120 is also shown operatively coupled to the valve 104, the first pump 108, and the second pump 112. As shown, the operative couplings between the controller 120 and the system 100 components are in the form of wired connections. While wired connections are illustrated, it will be understood that wireless connections (such as Bluetooth, Wi-Fi, near-field, radio connections, and the like) are possible and within the scope of the present disclosure.

[0055] The controller 120 is a functional element that choreographs and controls the operation of the other functional elements. In one embodiment, controller 120 is implemented with hardware logic (e.g., application specific integrated circuit, field programmable gate array, etc.). In yet another embodiment, controller 120 may be implemented as a general-purpose microcontroller 120 that executes software or firmware instructions stored in memory (e.g., non-volatile memory, etc.). Yet alternatively, controller 120 may be implemented in a combination of hardware and software and further may be centralized or distributed across multiple components.

[0056] In an embodiment, the controller 120 includes logic that, when executed, causes the system 100 to perform operations. In an embodiment, the controller 120 includes logic that, when executed, causes the system 100 to perform operations for performing one or more methods of the present disclosure and/or portions thereof.

[0057] In an embodiment, the operations include one or more of operations comprising pumping, with the first pump 108, an aliquot of the process water to the testing location 110; pumping, with the second pump 112, acid from the source of the acid to the testing location 110; generating, with the pH sensor 118, the pH signal based upon the pH of the combined flow; generating, with the peroxy carboxylic acid sensor 116, the peroxy carboxylic acid signal based upon the concentration of the peroxy carboxylic acid of the combined flow; and operating the valve 104 to provide an amount of the peroxy carboxylic acid to the process water source 102 based upon the peroxy carboxylic acid signal.

[0058] In an embodiment, an amount of the acid pumped with the second pump 112 is based upon the pH signal. In this regard, for example, if the pH signal is high, such as indicating a pH above 7, an amount of the acid pumped with the second pump 112 is increased to reduce the pH of the combined flow to below 7 such that the peroxy carboxylic acid sensor 116 can provide a more accurate peroxycarboxylic acid signal. In an embodiment, the controller 120 further includes logic that, when executed, causes the system 100 to perform operations including pumping, with the second pump 112, the acid into the combined flow when pH of the combined flow is greater than 6. Correspondingly, in an embodiment, the controller 120 further includes logic that, when executed, causes the system 100 to perform operations including stopping or reducing an amount of acid pumped with the second pump 112 into the combined flow when a pH of the combined flow is below a predetermined threshold. For example, if the peroxycarboxylic acid sensor 116 is configured to provide an accurate measurement of peroxy carboxylic acid concentration at a pH of below 6, the second pump 112 may reduce an amount of acid pumped into the combined flow if the pH sensor 118 generates a pH signal indicating that a pH of the combined flow is 2 at current levels of acid pumped by the second pump 112.

[0059] Once the pH of the combined flow is appropriately adjusted and an accurate determination or measurement of peroxy carboxylic acid concentration is made, the system 100 is configured to introduce an amount of the peroxycarboxylic acid to the tank 102 based upon the peroxycarboxylic acid signal from the peroxycarboxylic acid sensor 116. In this regard, in an embodiment, the controller 120 includes logic that, when executed, causes the system 100 to perform operations including operating the valve 104 to provide an amount of the peroxy carboxylic acid to the tank 102 based upon the peroxy carboxylic acid signal. For example, if the peroxy carboxylic acid signal indicates that peroxycarboxylic acid concentration in the process water is below a predetermined threshold, such as below a mandated or recommended concentration, the controller 120 operates the valve 104 to increase an amount of peroxy carboxylic acid in the process water. As an example, the controller 120 can operate the valve 104 to introduce an additional amount of peroxycarboxylic into the tank 102 so the concentration of the peroxy carboxylic acid meets or exceeds the predetermined threshold, for example based on a volume of the tank 102, volume of process water in the tank 102, concentration of the peroxy carboxylic acid in the source of peroxy carboxylic acid 106, concentration of the peroxyacetic acid in the process water, and the like.

[0060] As above, in certain embodiments, a basic or high pH peroxy carboxylic acid solution is used in or as the process water. Accordingly, in an embodiment, the system 100 includes or is in fluidic communication with a source of a caustic (see for example source of caustic 226 illustrated in and discussed further herein with respect to FIGURE 2). In an embodiment, the source of a peroxy carboxylic acid 106 is also a source of a caustic. In this regard, in an embodiment, the valve 104 is configured to selectively place the caustic source in fluidic communication with the tank 102.

[0061] As shown, the combined flow is configured to release into the tank 102 after passing through the testing location 110. Such a configuration reduces wastewater and reuses peroxycarboxylic acid, thereby reducing overall cost.

[0062] The illustrated embodiment is also shown to include a sample port 124 and a sample port valve 128. As shown, the sample port 124 is positioned downstream from the first pump 108, second pump 112, and the mixer 122. In this regard, the sample port 124 is positioned to receive the combined flow, such as a mixed combined flow. The sample port 124 may be used to test an aliquot, such as through opening of valve 134, such as in addition to testing of a portion of the aliquot tested within the testing location 110. In this regard, the sample port 124 allows for manual testing of the aliquot in addition to automated testing provided by the testing location 110, such as to verify signals provided by the pH sensor 118 and the carboxylic acid sensor disposed in the testing location 110.

[0063] As shown in Example 1 provided herein below, the systems of the present disclosure, such as system 100, are configured to measure peroxy carboxylic acid concentrations, such as with peroxycarboxylic acid sensor 116, accurately. In this regard, in an embodiment, the peroxycarboxylic acid sensor 116 is configured to generate a signal indicating a peroxycarboxylic acid concentration with a difference between an actual, titrated, or directly measured peroxy carboxylic acid concentration of less than 25 ppm, 20 ppm, 15 ppm, 10 ppm, 9 ppm, 8 ppm, 7 ppm, or 6 ppm.

[0064] In an embodiment, the system 100 includes a filter positioned between the tank 102 and the first pump 108, wherein the filter is configured to filter particles from the aliquot. While in certain embodiments, the system 100 includes a filter, in certain embodiments, the filter is not necessary or included.

[0065] Another system 200 in accordance with an embodiment of the present disclosure will now be described with respect to FIGURE 2. As shown, the system 200 includes a process water source 202 configured to carry process water; a valve 204 configured to selectively place a source of a peroxycarboxylic acid 206 in fluidic communication with the process water source 202; a first pump 208 configured to pump an aliquot of the process water from the process water source 202 to a testing location 210; a second pump 212 in fluidic communication with a source of an acid 214 and configured to pump a portion of the acid to the testing location 210 in a combined flow with the aliquot; a peroxy carboxylic acid sensor 216 positioned in the testing location 210 and configured to generate a peroxycarboxylic acid signal based upon a concentration of the peroxy carboxylic acid in the combined flow; and a pH sensor 218 positioned in the testing location 210 configured to generate a pH signal based on a pH of the combined flow. As shown, the first pump 208 is configured to pump an aliquot from the process water source 202 that is not from an outflow 232 of the process water source 202.

[0066] As shown, the system 200 includes a mixer 222 disposed fluidically between the first pump 208 and the second pump 212 on an upstream end and the testing location 210 on a downstream end. In an embodiment, the mixer 222 is an example of mixer 122.

[0067] The system 200 is shown to include a source of caustic 226 in selective fluidic communication with the process water source 202. As shown the system 200 includes a second valve 228 configured to selectively place the caustic source 226 in fluidic communication with the process water source 202.

[0068] In an embodiment, the caustic source 226 includes or is in fluidic communication with a caustic, such as sodium hydroxide, potassium hydroxide, and combinations thereof. As shown, the caustic source 226 is fluidically separated from the peroxycarboxylic acid source 206. The system 200 is shown to further include a second valve 228 configured to selectively place the caustic source 226 in fluidic communication with the process water source 202. In an embodiment, the controller 220 includes logic that, when executed, causes the system 200 to perform operations including operating the second valve 228 to place the caustic source 226 in fluidic communication with the process water, thereby introducing the caustic into the process water. In an embodiment, operating the second valve 228 includes operating the second valve 228 based upon an amount of peroxycarboxylic acid introduced into the process water by the valve 204, such as to manage or modulate a pH of the process water.

[0069] The system 200 is also shown to include a controller 220 operatively coupled to the first pump 208, the second pump 212, the pH sensor 218, the peroxy carboxylic acid sensor 216, and the valve 204. In an embodiment, controller 220 is an example of controller 120. In an embodiment, the controller 220 includes logic that, when executed, causes the system 200 to perform operations, such as operations to perform one or more steps or portions of the methods of the present disclosure. In an embodiment, the operations include one or more of pumping, with the first pump 208, an aliquot of the process water to the testing location 210; pumping, with the second pump 212, acid from the source of the acid to the testing location 210; generating, with the pH sensor 218, the pH signal based upon the pH of the combined flow; generating, with the peroxycarboxylic acid sensor 216, the peroxy carboxylic acid signal based upon the concentration of the peroxycarboxylic acid of the combined flow; and operating the valve 204 to provide an amount of the peroxycarboxylic acid to the process water source 202 based upon the peroxy carboxylic acid signal. As discussed further herein with respect to FIGURE 1, in an embodiment, an amount of the acid pumped with the second pump 212 is based upon the pH signal.

[0070] In the illustrated embodiment, the system 200 is configured to dispose of the aliquot through a drain 230, rather than returning the aliquot to the process water source 202. In this regard, the aliquot does not acidify the basic process water, which could require additional caustic from the caustic source 226.

[0071] Another example of a system 400 according to embodiments of the present disclosure will now be described with respect to FIGURE 4. As shown, the system 400 includes a process water source 402 configured to carry process water; a valve 404 configured to selectively place a source of a peroxycarboxylic acid 406 in fluidic communication with the process water source 402; a first pump 408 configured to pump an aliquot of the process water from the process water source 402 to a testing location 410. The system 400 is shown to further include a second pump 412 in fluidic communication with a source of an acid 414 and configured to pump a portion of the acid to the testing location 410 in a combined flow with the aliquot.

[0072] In the illustrated embodiment, the system 400 is shown to include a peroxy carboxylic acid sensor 416 positioned in the testing location 410 and configured to generate a peroxycarboxylic acid signal based upon a concentration of the peroxy carboxylic acid in the combined flow; and a pH sensor 418 positioned in the testing location 410 configured to generate a pH signal based on a pH of the combined flow.

[0073] The system 400 is shown to further include a controller 420 operatively coupled to various components of the system 400, such as the peroxy carboxylic acid sensor 416, the pH sensor 418, the first pump 408, the second pump 412, and the valve 404, and is configured to choreograph their operation. While certain operative coupling is shown by wired connections, it will be understood that wireless connections are possible and within the scope of the present disclosure.

[0074] As shown, the peroxycarboxylic acid sensor 416 is shown positioned downstream of the pH sensor 418. In certain embodiments, the peroxy carboxylic acid sensor 416 can be damaged if it contacts a fluid, such as fluid of a combined flow, having a pH that is too low. As discussed further herein, the system 400 can adjust a pH of the combined flow based on the pH signal generated by the pH sensor 418. By placing the pH sensor 418 upstream of the peroxycarboxylic acid sensor 416, the pH sensor 418 generates a pH signal of the combined flow upstream of the peroxycarboxylic acid sensor 416. Such a configuration can reduce the likelihood of inadvertently lowering the pH of the combined flow to a level that could damage the peroxycarboxylic acid sensor 416.

[0075] As above, the pH sensor 418 generates a pH signal based on the combined flow. If the pH sensor 418 generated a pH signal of combined flow downstream of the peroxy carboxylic acid sensor 416, such as because the pH sensor 418 was positioned downstream of the peroxy carboxylic acid sensor 416, it is possible that the pH signal could indicate that additional acid should be introduced with the second pump 412, even if the combined flow that has not yet reached the peroxy carboxylic acid sensor 416 has a sufficiently low pH for accurate peroxycarboxylic acid measurement. In such an instance, further addition of acid to the combined flow could lower the pH of the combined flow such that it would damage the peroxy carboxylic acid sensor 416.

[0076] In the illustrated embodiment, the system 400 is shown to include a sediment filter 456 positioned in fluidic communication with, adjacent to, and downstream of the process water source 402. The sediment filter 456 is configured to collect sediment that passes from the process water source 402 so that such sediment does not or is less likely to proceed on to the testing location 410 or other downstream components of the system 400 where it might clog such downstream components or interfere with measurement of the process water or combined flow. As shown, the sediment filter 456 is coupled to a solenoid 442 to configured to drain the sediment filter 456, such as periodically drain the sediment filter 456. In an embodiment, the sediment filter 456 is operatively coupled to the controller 420, which may be configured to regularly and/or periodically drain the sediment filter 456, such as by opening the solenoid 442. In this regard, in an embodiment, the solenoid 442 is configured to empty the sediment filter when in an open position, wherein the controller 420 is operatively coupled to the solenoid 442, and wherein the controller 420 includes logic that, when executed, causes the system 400 to perform operations including placing the solenoid 442 in an open configuration to empty the sediment filter 456.

[0077] The system 400 is shown to include a viewing window 452 positioned downstream of the first pump 408 and the second pump 412. In an embodiment, the viewing window 452 is optically transparent, transmissive, or otherwise configured to allow a viewer to see the combined flow flowing toward the testing location 410. Such a viewing window 452 is suitable to allow a user to see whether sediment or other particulate matter, such as might clog, foul, or otherwise inhibit measurement of the combined flow, is moving through the system 400 toward the testing location 410. In an embodiment, the viewing window 452 is included in the system 400 instead of a mixer as described further herein with respect to FIGURES 1 and 2.

[0078] As above, the system 400 includes a peroxy carboxylic acid sensor 416 positioned in the testing location 410 and configured to generate a peroxy carboxylic acid signal based upon a concentration of the peroxycarboxylic acid in the combined flow. In the illustrated embodiment, the testing location 410 between the pH sensor 418 and the peroxycarboxylic acid sensor 416 includes a flow channel 558 having a flow axis 450. As shown, the system 400 includes a peroxycarboxylic carboxylic acid sensor channel 454 providing fluidic communication between the flow channel 558 and the peroxy carboxylic acid sensor 416. The peroxy carboxylic carboxylic acid sensor channel 454 is shown to intersect the flow channel 558 at a non-orthogonal angle, such as relative to the flow axis 450. In an embodiment, the non-orthogonal angle is in a range between 0-45 degrees. In this regard, the combined flow is not configured to pass orthogonally past the peroxy carboxylic acid sensor 416. Rather, combined flow passes the peroxy carboxylic acid sensor 416 upwards and non-orthogonally. In this regard, fats and other organic matter in the combined flow are less likely to adhere to or foul the peroxycarboxylic acid sensor 416.

[0079] The system 400 is shown to further include a clean-in-place (CIP) flush channel 436. As shown, the CIP flush channel 436 is positioned downstream of the process water source 402. The CIP flush channel 436 is configured to flush fluid through various components of the system 400, including the sediment filter 456, pH sensor 418, peroxy carboxylic acid sensor 416, testing location 410 generally, etc. In an embodiment, the CIP flush channel 436 is configured to flush fluid, such as water, through the system 400. By flushing water through the system 400, organic material adhered to various internal components of the system 400, such as the pH sensor 418 or the peroxy carboxylic acid sensor 416, can be dislodged, thereby improving function of or flow through the components. In an embodiment, the CIP flush channel 436 is configured to flush a cleaning fluid or caustic through the system 400, thereby disinfecting the system 400, such as when the system 400 is not operational in processing a food product.

[0080] Fluidically coupled to the CIP flush channel 436, the system 400 is shown to further include a peroxy carboxylic acid flush channel 438, fluidically separated from the CIP flush channel 436 by a solenoid 444. The peroxycarboxylic acid flush channel 438 is configured to provide fluidic communication between the CIP flush channel 436 and the peroxycarboxylic acid sensor 416. When the CIP flush channel 436 provides fluid to the peroxy carboxylic acid flush channel 438, such as through opening solenoid 444, and, in certain embodiments, closing solenoid 446, water or a cleaning solution is passed past the peroxy carboxylic acid sensor 416 to dislodge organic material adhered thereto and clean the peroxycarboxylic acid sensor 416.

[0081] In an embodiment, the CIP flush channel 436 is fluidically coupled to a flush pump configured to flush fluid through the CIP flush channel 436, such as water and cleaning fluid discussed further herein. In an embodiment, the CIP flush channel 436 is fluidically coupled to a source of water, such as municipal water, and a source of cleaning fluid, such as through the flush pump.

[0082] Immediately downstream of the pH sensor 418 and the peroxy carboxylic acid sensor 416, the system 400 is shown to include flow meters 440. In an embodiment, the flow meters 440 are configured to generate a flow signal based on a flow rate or flow speed of the combined flow. As shown, the flow meters 440 are shown operatively coupled to the controller 420. In an embodiment, the controller 420 increases or decreases flow through the system 400, such as to increase or decrease a flow rate of the combined flow, based on the flow signal. Accordingly, in an embodiment, the flow meters 440 are operatively coupled to the controller 420, wherein the controller 420 further includes logic that, when executed, causes the system 400 to perform operations including adjusting, with the first pump 408, a flow rate of fluid flow through the system 400 based on the flow signal. Such an increase or decrease can be modulated through, for example, operation or modulation of the first pump 408. By increasing a flow rate or flow speed of the combined flow, organic matter in the testing location 410 can be dislodged. In this regard, in an embodiment, where the flow meters 440 generate a signal indicating that flow through the testing location 410 has stopped, the CIP flush channel can operate to flush flow through the testing location 410, such as through the PAA sensor flush channel 438 to dislodge any material stuck in the testing location 410, particularly on the PAA sensor 416.

[0083] Following passage of the combined flow through the flow meters 440, the combined flow can pass through a sample port 424 openable with a sample port valve 434. In use, the sample port 424 can be used to manually obtain a sample of the combined flow, such as to confirm measurements from the pH sensor 418 and peroxy carboxylic acid sensor 416. The combined flow is further shown flowing back into the process water source 402, which can flow out of outflow 432. Alternatively, such as when sample port valve 434 is in a closed configuration, the combined flow can bypass the sample port 424 and freely flow back into the process water source 402.

[0084] The system 400 is further shown to include solenoids 442, 444, 446, and 448 coupled to various portions of the system 400, such as the CIP flush 436, peroxy carboxylic acid sensor flush 438, process water source 402, and sediment filter 456, which are configured to selectively open and close to place the components in fluidic communication and direct flow of fluids through the system 400. In an embodiment, one or more of the solenoids 442, 444, 446, and 448 are operatively coupled to the controller 420, such as through wireless communication, where the controller 420 includes logic that, when executed, causes the system 400 to perform operations for opening or closing the solenoid(s) 442, 444, 446, and 448.

METHODS

[0085] In another aspect, the present disclosure provides methods for monitoring and/or adjusting a concentration or an amount of a peroxycarboxylic acid, such as in process water.

[0086] In this regard, attention is directed to FIGURE 3, which is a block diagram of a method 300 in accordance with an embodiment of the present disclosure. In an embodiment, the method 300 is suitable to be performed on the systems of the present disclosure, such as system 100 discussed further herein with respect to FIGURE 1, system 200 discussed further herein with respect to FIGURE 2, and/or system 400 discussed further herein with respect to FIGURE 4.

[0087] In an embodiment, method 300 begins with process block 301, which includes pumping, with a first pump, such as first pumps 108 or 208, an aliquot of process water from a process water source, such as process water sources 102 or 202, to a testing location, such as testing locations 110 or 210, downstream from the process water source. In an embodiment, the process water comprises a peroxycarboxylic acid, such a peracetic acid. In an embodiment, the process water comprises a foodstuff, such as one or more poultry carcasses being processed (i.e., disinfected).

[0088] In an embodiment, pumping, with the first pump, comprises continuously pumping, with the first pump, aliquots of the process water including the aliquot to the testing location during. In this regard, the method 300 is suitable to continuously and iteratively test the process water for peroxycarboxylic acid concentration. In an embodiment, continuous pumping of aliquots of the process water refers to serial pumping of concatenated or adjacent aliquots of the process water.

[0089] In an embodiment, pumping, with the first pump, comprises periodically pumping, with the first pump, aliquots of the process water including the aliquot to the testing location during. As an example, in an embodiment, pumping, with the first pump, the process water includes pumping aliquots at a frequency, such as every minute, every 5 minutes, every 10 minutes, every hour, and the like during operation or performance of the method 300. [0090] In an embodiment, process block 301 is followed by process block 303, which includes pumping, with a second pump, such as second pumps 112 or 212, acid from a source of the acid, such as acid sources 114 or 214, to provide a combined flow of the aliquot and the acid. In an embodiment, pumping the combined flow with the second pump and the first pump includes pumping the combined flow to and/or through the testing location. In an embodiment, the combined flow is pumped with a combination of flows from the first pump and the second pump.

[0091] In an embodiment, pumping, with the second pump, occurs when the pH of the combined flow is greater than 7 or greater than 6. As discussed further herein, in an embodiment, the method 300 is iterative, such that a measured pH of an aliquot can be adjusted in subsequent aliquots. In other words, when an aliquot has a pH higher than a predetermined threshold, such as over 6, the second pump can be used to pump acid or to pump additional acid into a subsequent aliquot so that a concentration of peroxy carboxylic acid therein can be more accurately determined or measured.

[0092] In an embodiment, process block 303 is followed by process block 305, which includes flowing the combined flow through a mixer, such as mixer 122, to provide a combined mixed flow. In an embodiment, the combined mixed flow is substantially homogeneous. In an embodiment, the substantially homogeneous combined mixed flow has concentration variations of, for example, the acid and/or peroxycarboxylic acid of less than 5%. In an embodiment, the mixer is one of mixers 122 or 222.

[0093] In an embodiment, the mixer is disposed between the first pump and the testing location. In an embodiment, the mixer is disposed between the second pump and the testing location. In an embodiment, the mixer is disposed upstream of the testing location. In an embodiment, the mixer is disposed downstream of the first pump and the second pump.

[0094] In an embodiment, process block 305 is optional.

[0095] In an embodiment, process blocks 303 or 305 are followed by process block 307, which includes measuring a pH of the combined flow. In an embodiment, measuring the pH of the combined flow comprises generating, with a pH sensor, such as pH sensors 118 or 218, disposed in the testing location, a pH signal based upon the pH of the combined flow. In an embodiment, the pH signal is indicative of and/or based upon the pH of the combined flow. In an embodiment, the pH signal is converted or correlated to the pH of the combined flow. [0096] In an embodiment, measuring the pH of the combined flow comprises generating, with a pH sensor, such as pH sensors 118 or 218, disposed in the testing location, a pH signal based upon a pH of the combined flow.

[0097] In an embodiment, the pH of the combined flow is measured at a predetermined frequency. In an embodiment, the rate of pH measurement is determined by a flow rate of the combined flow. In an embodiment, the pH of the combined flow is measured continuously during operation of the system.

[0098] In an embodiment, process block 307 is followed by process block 309, which includes measuring the concentration of the peroxy carboxylic acid of the combined flow. In an embodiment, measuring the concentration of the peroxycarboxylic acid of the combined flow comprises generating, with a peroxycarboxylic acid sensor, such as peroxycarboxylic acid sensors 116 or 216, disposed in the testing location, a peroxy carboxylic acid signal based upon the concentration of the peroxy carboxylic acid of the combined flow. In an embodiment, the peroxycarboxylic acid signal is correlated with or converted to a concentration of the peroxycarboxylic acid in the combined flow. In an embodiment, the measurement of the concentration of the peroxycarboxylic acid is timed such that the same aliquot or volume of the combined flow is tested for both pH and concentration of peroxy carboxylic acid.

[0099] In an embodiment, method 300 further includes calibrating the peroxy carboxylic acid sensor, such as to ensure accurate or more accurate measurement of peroxy carboxylic acid concentration. In the absence of calibration of the peroxy carboxylic acid sensor, peroxy carboxylic acid concentration may be inaccurate or less accurate than if a calibration step had been performed. See, for example, Table 3.

[0100] In an embodiment, the concentration of the peroxycarboxylic acid is measured periodically, such as at a predetermined rate. In an embodiment, the predetermined rate of peroxycarboxylic acid concentration measurement is the same as, correlated with, or otherwise based on the rate or frequency of pH measurement. For example, in an embodiment, the timing of measuring the peroxycarboxylic acid concentration is timed so that a common volume of the combined flow, i.e., the aliquot, is measured for both pH and peroxycarboxylic acid concentration. In this regard, there may be a delay in the timing of these measurements such that the aliquot is measured, for example, for its pH and then the same aliquot is measured for its peroxycarboxylic acid concentration after it flows downstream to the peroxycarboxylic acid sensor. In an embodiment, the rate or frequency of peroxy carboxylic acid concentration measurement is based upon a flow rate of the combined flow through testing location.

[0101] In an embodiment, the measuring the peroxyacetic acid concentration includes taking into account a volume of the acid solution from the second pump and any dilution of the aliquot that occurred in generating the combined flow with the aliquot and the acid. In this regard, measuring the peroxyacetic acid concentration can be based, for example, on the peroxyacetic acid signal, the volume of the aliquot, and the volume of the acid added to the aliquot.

[0102] In an embodiment, process block 309 is followed by process block 311, which includes providing an amount of peroxycarboxylic acid to the process water source based upon the peroxy carboxylic acid concentration in the aliquot. In embodiment, process block 311 includes operating a valve, such as valves 104 or 204, to provide an amount of peroxy carboxylic acid to the treatment process water source based upon the concentration of the peroxycarboxylic acid, such as based upon a peroxyacetic acid concentration signal produced by a peroxyacetic acid sensor in the testing location, as discussed further herein with respect to process block 309.

[0103] In an embodiment, process block 311 is optional, such as when the peroxyacetic acid concentration is at or above a predetermined threshold. In an embodiment, process block 311 includes providing additional water to the process water source to dilute the process water, such as where the peroxyacetic acid concentration is above the predetermined threshold.

[0104] In an embodiment, process block 311 is followed by process block 313, which includes pumping, such as with the second pump, additional acid into the combined flow. In an embodiment, when the pH of the combined flow is too high, accurate measurement of the peroxyacetic acid concentration is not possible, more difficult, or less reliable. In such instances, the method 300 can include pumping additional acid into the combined flow to lower the pH of the combined flow. In an embodiment, an amount of the acid pumped with the second pump is based upon the pH signal. In an embodiment, process block 313 is optional, such as when the pH of the combined flow is sufficiently low, such as below 7.

[0105] As shown, in an embodiment, method 300 can be iterative. In this regard, in an embodiment, after process blocks 311 or 313, the method 300 can return to process block 301 to begin the method 300 again. In an embodiment, method 300 is repeated continuously, such as when the first pump pumps aliquots continuously during performance of method 300. In an embodiment, the method 300 includes performing one or more of the process blocks at a predetermined frequency. In an embodiment, the method 300 includes performing one or more process blocks at a frequency that is determined during performance of the method 300.

[0106] The order in which some or all of the process blocks appear in process 300 should not be deemed limiting. Rather, one of ordinary skill in the art having the benefit of the present disclosure will understand that some of the process blocks may be executed in a variety of orders not illustrated, or even in parallel.

[0107] The processes explained above are described in terms of computer software and hardware. The techniques described may constitute machine-executable instructions embodied within a tangible or non-transitory machine (e.g., computer) readable storage medium, that when executed by a machine will cause the machine to perform the operations described. Additionally, the processes may be embodied within hardware, such as an application specific integrated circuit (“ASIC”) or otherwise.

[0108] A tangible machine-readable storage medium includes any mechanism that provides (i.e., stores) information in a non-transitory form accessible by a machine (e.g., a computer, network device, personal digital assistant, manufacturing tool, any device with a set of one or more processors, etc.). For example, a machine-readable storage medium includes recordable/non-recordable media (e.g., read only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, flash memory devices, etc.).

EXAMPLES

EXAMPLE 1 : HIGH PH PAA SOLUTION CONTINUOUS MONITORING

WITH IN-LINE PAA PROBE

1.1 CHEMICALS:

[0109] Prevenio 22% OxypHresh peracetic acid (PAA). Prevenio BasicpHresh (caustic). 0.8% (loz per 1 gallon of water)

[0110] Prevenio PoultrypHresh (Sulfuric acid solution).

1.2 TEST METHOD FOR PAA TITRATION:

[OHl] 30 mL of test solution was used. The endpoint of the titration was determined by a definite change of the sample from dark orange/brown to clear. Concentration of PAA in ppm was calculated by multiplying the number of drops of 0. IN sodium thiosulfate added to obtain a clear solution by 5 ppm per drop.

1.3 STOCK SOLUTION:

[0112] A solution with a target of 150 ppm PAA and pH target of 10-11 was made to represent conditions in a clean poultry immersion chiller system. A 60-quart Igloo cooler was used to mix and contain the stock solution for each test. Tap water (28 or 38L) was added to the container. A submersible water pump (Geoglobal partners 84577) was placed in the water to mimic agitation in a chiller system to ensure a thorough mix of the chemistry added into the stock solution. 22% OxypHresh PAA was added until an initial target >150 ppm was reached. A drop titration (method described in 1.2) was performed to test and confirm PAA concentrations. Once target PAA concentration was achieved, a pH probe (Oakton pH 2700) was placed in the stock solution to monitor pH of the solution. BasicpHresh was added to the stock solution to raise the pH until a pH target of 10-11 was achieved. A second PAA titration was performed and recorded post pH adjustment.

1.4 EXPERIMENT SET UP:

[0113] Two peristaltic pumps, an amphoteric PAA monitoring probe (Walchem PES7L), and pH probe (Oakton pH 2700) were used in the setup of the flow loop to monitor the pH and PAA concentrations of the solution throughout the experiment. One peristaltic pump was allocated to transfer the stock solution into the flow loop at 35% speed. The second peristaltic pump was allocated to dose a 0.8% solution of PoultrypHresh at 1 or 1.5% speed into the flow loop line to lower the pH of the stock solution prior to passing by the PAA monitoring probe. The drop in pH of the flow loop solution was monitored by a pH probe (Oakton pH 2700) placed into the flow loop line. The flow loop solution was targeted at a pH <6 prior to passing by the PAA monitoring probe. Flow loop solution was discharged into an empty 60-quart Igloo cooler containment.

1.5 EXPERIMENT:

[0114] Four total replications of the experiment were completed and recorded. Once target concentrations of stock chiller solution were achieved, the peristaltic pumps were turned on to start the experiment. PAA concentrations and pH of the stock solution and flow loop solution were monitored and recorded at the following time intervals: 0, 5, 15, 30, 45, and 60 minutes. The differences in PAA concentration of the flow loop solution between the in-line PAA probe and PAA titration method were recorded.

1.6 RESULTS: [0115] The results from the four replications are provided in the Tables Below.

*No PAA calibration with this test.

* PAA Probe used was the Bogart labs benchtop probe. Handheld went out. Was unable to adjust chemistry during test with only 1 pH probe.

** two separate containers were used for these tests. Stock solution represented the chiller for intake solution. A separate container was used for the discharge solution post flowcell.

[0116] The average of the four replications of the experiment are in TABLE 6.

TABLE 6

[0117] The PAA probe was able to monitor the PAA concentration of the flow loop solution with an average of approximately 6 ppm difference between the PAA probe reading and the titration method. This experiment demonstrates the PAA probe can accurately monitor PAA concentrations in high pH treated poultry immersion chillers over time.

EXAMPLE 2: HIGH PH PAA SOLUTION CONTINUOUS MONITORING

PAA CONCENTRATION IN POULTRY PROCESS WATER

[0118] A PAA Chiller Monitor system similar to the system illustrated in FIGURE 4 was validated over 3 consecutive days for several hours each day.

[0119] The PAA Chiller Monitor system controlled by a Walchem W900 series controller was installed on a pre-chiller for observations and testing. A U-inch stainless steel valve and sample port was installed in the vessel wall for the process water source. The pump removed water from the vessel, and it passed through the sediment filter before entering the system. A second metering pump injected a 0.8% sulfuric acid solution into the process stream. The acid injection is controlled and monitored by a Walchem pH probe (WEL-PHF-NN) to maintain a target range between pH 3-5 in the combined flow of the detection zone. The process water continued to through the system and a small portion between 0.2-0.6 gpm was diverted from the primary stream over the PAA probe. The flow was monitored by an IFM SM6004. The system automatically adjusted the flow to maintain the target gpm. If the system detected a blockage, the CIP flush system was activated for a desired amount of time. During field testing, the CIP flush system was scheduled every 15 min for 6 secs. A second IFM SM6004 flow meter was utilized to assist with detecting a blockage and process flow monitoring. After flowing past the PAA probe, the process stream exited the system to a drainage system.

[0120] The system was connected via flexible U-inch polytubing to a stainless-steel sample port located on the pre-chiller body wall. The process pump and acid pump were energized to begin operation. The system was allowed to stabilize for 25 min before instrument calibration. A 2-pt calibration was completed on the pH probe with a pH buffer 4 and pH buffer 7. Aquaphoenix PAA titration kits were used for the probe calibration process and measurements throughout the field trial. The PAA probe received a 1-pt calibration each day. The differences in PAA concentration of the flow loop solution between the in-line PAA probe, PAA titration method and standard measurements were recorded.

[0121] Signal from the PAA probe can vary based on flow and pH fluctuations. During the calibration process of the PAA probe, these conditions are configured as part of the calibration. The conditions of pH and flow were maintained to improve accuracy of the PAA reading.

[0122] Large sediments from the evisceration process occasionally obstructed flow through the system. A sediment filter with an automated flush valve was included at an upstream portion of the system to mitigate blockages for consistent flow.

[0123] To monitor flow across the PAA probe and through the system, a flow meter was installed to monitor flow and automatically adjust as needed. Further, the pH probe was positioned upstream of the PAA probe to protect it from encounters of low (i.e., pH <1), which could damage the PAA probe. Allowing the pH probe to measure the process water before the PAA probe increased service life and improved accuracy of the system. During extended operation of the system, normal organics from the process could accumulate at the base of the probe decreasing with the accuracy of the readings. The flow cell containing the PAA probe was positioned between 0-45 degrees to limit the amount of fat accumulation thereon. A Clean-in-Place (CIP) flush was included in the system to automatically flush organics from the PAA probe to improve system performance.

[0124] TABLE 7

[0125] TABLE 8

[0126] TABLE 9

[0127] Differences between standard PAA measurements (i.e., those measurements made by the standard pre-chiller system) and those in the flow loop of the present disclosure are provided in TABLE 10.

[0128] TABLE 10: Differences between standard PAA concentration measurements and flow loop measurements

[0129] As shown in TABLE 10, by controller PAA concentration with the system of the present disclosure, particularly measuring PAA concentration at a relatively low pH that has a lower pH than the process water in the process water source, the system of the present disclosure is able to maintain PAA concentration closely within a goal concentration, such as within 10-15 ppm over an extended period. See also FIGURES 5A- 5C.

[0130] By contrast, FIGURE 6 illustrates peroxycarboxylic acid concentration in a combined flow over time as measured by a peroxycarboxylic acid sensor of a system according to an embodiment of the present disclosure, where initial pH of the combined flow is roughly that of the process water (i.e., approximately 10-11). See also TABLE 11.

[0131] TABLE 11 :

[0132] As shown, the pH in the flow loop (i.e., the combined flow) starts high and decreases over time below 6. As shown in TABLE 12, as the pH lowers, the difference in PAA concentration as measured by the PAA sensor and actual PAA concentration correspondingly lowers. As also shown, there is a drastic decrease in this difference as the pH in the flow loop (i.e., in the combined flow in the testing region) decreases below 6. [0133] TABLE 12

[0134] FIGURE 6 and TABLES 11 and 12 demonstrate how low pH of combined flow leads to more accurate PAA concentration measurements, such as in a flow loop or detection zone of the systems of the present disclosure.

[0135] The above description of illustrated embodiments of the invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize.

[0136] These modifications can be made to the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification. Rather, the scope of the invention is to be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation.

[0137] It should be noted that for purposes of this disclosure, terminology such as “upper,” “lower,” “vertical,” “horizontal,” “inwardly,” “outwardly,” “inner,” “outer,” “front,” “rear,” etc., should be construed as descriptive and not limiting the scope of the claimed subject matter. Further, the use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” and “mounted” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. The term “about” means plus or minus 5% of the stated value.

[0138] While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.

Claims

CLAIMS The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A system comprising: a process water source configured to carry process water; a valve configured to selectively place a source of a peroxy carboxylic acid in fluidic communication with the process water source; a first pump configured to pump an aliquot of the process water from the process water source to a testing location; a second pump in fluidic communication with a source of an acid and configured to pump a portion of the acid to the testing location in a combined flow with the aliquot; a peroxy carboxylic acid sensor positioned in the testing location and configured to generate a peroxycarboxylic acid signal based upon a concentration of the peroxy carboxylic acid in the combined flow; a pH sensor positioned in the testing location configured to generate a pH signal based on a pH of the combined flow; and a controller operatively coupled to the peroxy carboxylic acid sensor, the pH sensor, the first pump, the second pump, and the valve, the controller including logic that, when executed, causes the system to perform operations including: pumping, with the first pump, an aliquot of the process water to the testing location; pumping, with the second pump, acid from the source of the acid to the testing location; generating, with the pH sensor, the pH signal based upon the pH of the combined flow; generating, with the peroxycarboxylic acid sensor, the peroxycarboxylic acid signal based upon the concentration of the peroxycarboxylic acid of the combined flow; and operating the valve to provide an amount of the peroxycarboxylic acid to the process water source based upon the peroxy carboxylic acid signal.

2. The system of Claim 1, wherein an amount of the acid pumped with the second pump is based upon the pH signal.

3. The system of Claim 1, wherein the controller further includes logic that, when executed, causes the system to perform operations including pumping, with the second pump, the acid into the combined flow when pH of the combined flow is greater than 6.

4. The system of Claim 1, further comprising a mixer configured to mix the aliquot and the acid of the combined flow to provide a mixed combined flow.

5. The system of Claim 4, wherein the mixer is positioned between the first pump and the testing location.

6. The system of Claim 4, wherein the mixer is configured to provide a substantially homogenous mixed combined flow.

7. The system of Claim 1, further comprising a sample port configured to expel a portion of the combined flow from the system.

8. The system of Claim 1, wherein the combined flow is configured to release into the process water source after passing through the testing location.

9. The system of Claim 1, wherein the combined flow is configured to release into a drain after passing through the testing location.

10. The system of Claim 1, wherein the peroxy carboxylic acid solution comprises peracetic acid (PAA).

11. The system of Claim 1, wherein the valve is configured to selectively place a caustic source in fluidic communication with the process water source.

12. The system of Claim 1, further comprising a second valve configured to selectively place a caustic source in fluidic communication with the process water source.

13. The system of Claim 1, wherein the acid has a pH of less than 1.

14. The system of Claim 1, wherein the aliquot is not removed from an outflow of the process water source.

15. The system of Claim 1, further comprising a filter positioned between the process water source and the first pump, wherein the filter is configured to filter particles from the aliquot.

16. The system of Claim 15, further comprising a solenoid configured to empty the filter when in an open position, wherein the controller is operatively coupled to the solenoid, and wherein the controller includes logic that, when executed, causes the system to perform operations including placing the solenoid in an open configuration to empty the filter.

17. The system of Claim 1, wherein the controller further includes logic that, when executed, causes the system to perform operations including continuously pumping, with the first pump, aliquots of the process water including the aliquot to the testing location during a duty cycle of the system.

18. The system of Claim 1, wherein the pH sensor is positioned upstream of the peroxy carboxylic acid sensor.

19. The system of Claim 1, further comprising one or more flow meters configured to generate a flow signal based on a flow rate of the combined flow.

20. The system of Claim 19, wherein the one or more flow meters are operatively coupled to the controller, wherein the controller further includes logic that, when executed, causes the system to perform operations including adjusting, with the first pump, the flow rate of fluid flow through the system based on the flow signal.

21. The system of Claim 1, wherein the testing location comprises: a flow channel configured to flow the combined flow and defining a flow axis; and a peroxycarboxylic carboxylic acid sensor channel providing fluidic communication between the flow channel and the peroxycarboxylic acid sensor, wherein the peroxycarboxylic carboxylic acid sensor channel intersects the flow channel at a non-orthogonal angle relative to the flow axis.

22. The system of Claim 21, wherein the non-orthogonal angle is in a range between 0-45 degrees.

23. The system of Claim 1, further comprising a clean-in-place flush channel positioned downstream of the process water source fluidically coupled to the testing location and configured to flush fluid through the testing location.

24. A method for adjusting concentration of peroxycarboxylic acid in a process water source, the method comprising: pumping, with a first pump, an aliquot of process water from the process water source to a testing location downstream from the process water source; pumping, with a second pump, acid from a source of the acid to the testing location to provide a combined flow of the aliquot and the acid; measuring a pH of the combined flow; measuring the concentration of the peroxycarboxylic acid of the combined flow; and operating a valve to provide an amount of peroxycarboxylic acid to the process water source based upon the concentration of the peroxy carboxylic acid.

25. The method of Claim 24, wherein an amount of the acid pumped with the second pump is based upon the pH of the combined flow.

26. The method of Claim 24, wherein pumping, with the second pump, occurs when the pH of the combined flow is greater than 6.

27. The method of Claim 24, wherein pumping, with the first pump, comprises continuously pumping, with the first pump, aliquots of the process water including the aliquot to the testing location during.

28. The method of Claim 24, wherein measuring the pH of the combined flow comprises generating, with a pH sensor disposed in the testing location, a pH signal based upon a pH of the combined flow; wherein measuring the concentration of the peroxy carboxylic acid of the combined flow comprises generating, with a peroxycarboxylic acid sensor disposed in the testing location, a peroxycarboxylic acid signal based upon the concentration of the peroxy carboxylic acid of the combined flow, and wherein operating a valve to provide an amount of peroxycarboxylic acid to the process water source is based upon the peroxycarboxylic acid signal.