Disinfection acid production systems and methods

Abstract

Systems for producing disinfection acid and methods for producing disinfection acid. The systems may include one or more conduits having one or more reaction tubes disposed therein for producing the disinfection acid. The system may include incorporating the one or more reaction tubes into a pre-existing conduit, such as a conduit used in a wastewater treatment plant or other industrial process, so as to take advantage of the latent heat and flow rate of fluid flowing through the pre-existing conduit.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 63 / 616,334, filed December 29, 2023, which is incorporated herein by reference. FIELD OF THE DISCLOSURE

[0002] This disclosure relates generally to disinfection acid production systems and to methods for producing disinfection acid and, in particular, relates to disinfection acid production systems having reaction tubes incorporated within conduits having a fluid flowing therethrough. BACKGROUND

[0003] Disinfection acid such as performic acid is commonly used for disinfecting water or aqueous solutions. For example, disinfection acid may be used for treating drain water, water used in horticulture, or any water in need of treatment. Performic acid, for example, is an effective disinfectant for harmful microorganisms, such as fungi, viruses, bacteria, yeasts, and algae, and degrades into harmless byproducts, including carbon dioxide, oxygen, and water.

[0004] Prior performic acid production systems typically combine acids and hydrogen peroxide in a reactor to produce performic acid. In production systems in which performic acid is produced in a coil-type reactor, a ramp-up time of at least 10 minutes, often at least 20 minutes, is usually required before any performic acid is produced. A substantial amount of the time associated with this ramp-up relates to temperature regulation. Performic acid is synthesized by the reaction of formic acid and hydrogen peroxide in an equilibrium reaction. The time required to reach the equilibrium is inversely proportional with the reaction temperature. Thus, controlling the temperature of the reaction may be critical depending on the desired flow rate and concentration of performic acid.

[0005] Performic acid may be used to treat water and aqueous solutions due at least in part, to its ease of production and harmless byproducts. However, because of its instability, performic acid usually is produced on-site as the need arises.

[0006] High throughput applications of performic acid include treatment of municipal water supply, treatment of water for industrial farming, and the like. In some situations, continuous and uninterrupted water treatment is needed, such as to treat municipal water supply during and after a storm, or during and after an event attracting a large amount of people. In some situations, varying amounts of performic acid are needed, such as a greater amount immediately following heavy rain, a lesser amount after water levels have reduced or in periods of drought, or varying amounts in response to the natural fluctuation of moisture in waste water.

[0007] Since the reaction of formic acid with hydrogen peroxide is an exothermic process, current performic acid production systems often include cooling means, such as a water bath, the temperature of which is heated or cooled to control the temperature of the reaction. A cooling system may comprise e.g. a heat exchanger or similar thermal transfer means for cooling the water bath and for extracting the heat generated by the performic acid reaction and discharging the heat into the environment. The components associated with this heat exchanger require maintenance in addition to that required by the reaction components themselves because a failure or other downtime associated with the heat exchanger results in ceasing production of the acid. Furthermore, the heat exchanger is often supplied with a cooling medium, representing yet another raw material necessary for the production of the acid.

[0008] Thus, disinfection acid production systems having the ability to quickly produce a desired amount of disinfection acid, without delays or additional equipment, materials, and maintenance for temperature regulation, would be beneficial. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The detailed description is set forth with reference to the accompanying drawings. The use of the same reference numerals may indicate similar to identical items. Various embodiments may utilize elements and / or components other than those illustrated in the drawings, and some elements and / or components may not be present in various embodiments. Elements and / or components in the figures are not necessarily drawn to scale. Throughout this disclosure, depending on the context, singular and plural terminology may be used interchangeably.

[0010] FIG. 1 is a system for producing disinfection acid in a conduit in accordance with an embodiment of the disclosure.

[0011] FIG. 2 is a system for producing disinfection acid in a pre-existing conduit in accordance with an embodiment of the disclosure.

[0012] FIG. 3 is a system for producing disinfection acid having multiple reaction tubes in a pre-existing conduit in accordance with an embodiment of the disclosure.

[0013] FIG. 4 is a system for producing disinfection acid having an adjustable reaction tube in a pre-existing conduit in accordance with an embodiment of the disclosure.

[0014] FIG. 5 is a system for producing disinfection acid having multiple reaction tubes in a pre-existing conduit in accordance with an embodiment of the disclosure.

[0015] FIGS. 6A-6C depict exemplary reaction tube shapes in accordance with embodiments of the disclosure. DETAILED DESCRIPTION

[0016] Disinfection acid production systems and methods of producing disinfection acid are provided herein including disinfection acid production systems, and methods of production that advantageously reduce the impact of reaching and maintaining temperature equilibrium on disinfection acid production, increase the capabilities of the system to react to varying production demands, reduce the complexity of systems in which multiple means of production are combined, or a combination thereof. The present disclosure includes non-limiting embodiments of disinfection acid production systems. The embodiments are described in detail herein to enable one of ordinary skill in the art to practice the disinfection acid production systems and methods of producing disinfection acid, although it is to be understood that other embodiments may be utilized and that logical changes may be made without departing from the scope of the disclosure.

[0017] Throughout this disclosure, various aspects are presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the disclosure. Accordingly, the description of a range should be considered to have specifically disclosed all the possible sub-ranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0018] Although embodiments described herein may be described with respect to the formation of performic acid from the reaction of formic acid with hydrogen peroxide, other disinfection acids may be produced using the systems described herein, such as the production of chlorine dioxide disinfectant from a chlorine-chlorite reaction of chlorine gas with water; the production of peracetic acid from the reaction of acetic acid with hydrogen peroxide; or other suitable disinfectants. The decision to recite performic acid to the exclusion of other disinfection acids is in the interest of brevity only and is not intended to limit the disclosure.

[0019] In embodiments in which performic acid is produced by the systems and methods described herein, any known method of making performic acid can be used. For example, performic acid may be produced by mixing 70-80 wt% formic acid and 30-50 wt% hydrogen peroxide, optionally in the presence of a catalyst. The catalyst may be combined with the formic acid to form a liquid containing, e g., 70-80 wt% formic acid and 5-15 wt% catalyst, with the balance being water. Suitable catalysts may include sulfuric acid, nitric acid, hydrofluoric acid, phosphoric acid, sulfuric acid, a salt thereof, or a combination thereof. At equilibrium, a performic acid mixture may be produced containing performic acid, unreacted formic acid, unreacted hydrogen peroxide, and water. The concentration of performic acid in the performic acid mixture may be, e.g., from 10 % to 16 %, by weight, from 12 % to 16 %, by weight, from 7 % to 12 %, by weight, based on the weight of the performic acid mixture, or another concentration depending on the concentration of hydrogen peroxide used.

[0020] Systems for Disinfection Acid Production

[0021] Systems for disinfection acid production are disclosed herein. In some embodiments, the system for producing disinfection acid includes one or more conduits. Each of the one or more conduits includes a fluid flow inlet for receiving a flow of fluid and a fluid flow outlet for discharging the flow of fluid. In some embodiments, the fluid flowing through the one or more conduits is water.

[0022] In some embodiments, the system includes at least one reaction tube disposed in each of the one or more conduits such that the flow of fluid contacts the at least one reaction tube. In some embodiments, each of the at least one reaction tubes includes a reaction portion, one or more reactant inlets for receiving one or more disinfection acid reactants, and a reaction outlet for discharging the disinfection acid. As used herein, the “reaction portion” refers to a length of the reaction tubes downstream of the reactant inlets, but upstream of the reaction outlet, where all of the disinfection acid reactants are in contact with one another and therefore reacting to produce the disinfection acid.

[0023] As used herein, a “conduit” refers to a vessel for communicating a flow of fluid. The conduit may be partially open or exposed, such as a trough or flume, or may resemble a pipe or other closed cylinder with a fluid flow inlet and a fluid flow outlet in which the reaction tube is positioned. The conduit may be an open cylinder with fluid flowing into the conduit at one end and out of the conduit at the other end. The conduit may have a circular cross-section, a square cross-section, rectangular cross-section, triangular cross-section, or another cross-sectional shape. The conduit may be open to the environment, such as for wastewater treatment plants. Any suitable conduit having a flow of fluid may be utilized in the systems described herein.

[0024] As used herein, a “reaction tube” refers to a tube, pipe, coil, or other enclosed conduit in which the disinfection acid reactants may be combined and be permitted to react to form the disinfection acid. The reaction tube may take the form of a three-dimensional helical coil, a twodimensional coil-like structure with numerous straight paths joined by bent regions to form an “S”-like structure, a straight pipe, or another shape. When multiple reaction tubes are incorporated within the system, each reaction tube may have the same shape or different shapes. Any suitable shaped reaction tube may be utilized in the embodiments described herein.

[0025] A reaction tube is “contacted” by the flow of fluid when it is arranged at a position that permits, or would permit, all or a portion of the reaction tube to be submerged during normal operation of the fluid flow. The fluid flowing through the conduit may allow control over temperature, e.g., the temperature of the reactants or product while in a reaction tube, upon exiting a reaction tube, etc. The one or more reaction tubes may have a length and crosssectional area that determines, at least in part, the residence time of the precursors in the reaction tube. The flow rate of the reactants through the reaction tube may determine, at least in part, the residence time of the precursors in the reaction tube. Therefore, modifying (i) the length of the reaction tube (e.g., by switching a flow of reactants from a first reaction tube to a second reaction tube of a different length, as described herein), (ii) the flow rate of reactants through a reaction tube, (iii) the temperature of the fluid that is contacting the reaction tube, or (iv) a combination thereof may determine, at least in part, the concentration of the disinfection acid produced. In some embodiments, a conduit has two reaction tubes that have different lengths so that one system is capable of producing two different concentrations of disinfection acid depending on the needs of the application. For example, a first reaction tube having a first length may be configured to produce a first concentration of disinfection acid in periods of average demand, while a second reaction tube having a second, and greater, length may be configured to produce a second concentration of disinfection acid in periods of high demand. In some embodiments, a conduit includes a plurality of reaction tubes, each having a reaction tube length that is greater than, equal to, or less than any other reaction tube length. For example, a conduit may have three reaction tubes that have different lengths so that one unit is capable of producing three different concentrations of disinfection acid depending on the needs of the application. In some embodiments, a reactor unit has four reaction tubes, five reaction tubes, six reaction tubes, or more than six reaction tubes, depending on the needs of the application.

[0026] In some embodiments, at least one of the one or more conduits is a pre-existing conduit. As used herein, a “pre-existing conduit” refers to a conduit with a fluid flow having a preexisting purpose other than as part of the systems described herein. For example, a conduit may exist in a facility that is configured to transmit a fluid; this fluid may have a particular temperature and flow rate associated with the pre-existing purpose. In some embodiments, the one or more pre-existing conduits may include water conduits in municipal or other governmental, industrial, agricultural, or residential water flow management or water treatment systems or facilities. For example, many wastewater treatment facilities utilize a microbial treatment to remove organics present in the wastewater. Thus the waste water is heated, if needed, to a temperature in which the efficacy of these microbes is preserved. The temperatures in such biological treatment of waste water vary and may be between, e.g., 20°C to 40°C, but may also have other temperatures, e.g. around 15°C, depending on the process, microbe, environment, etc. Thus, incorporating the reaction tube into a wastewater treatment facility can eliminate the need for temperature regulation in the disinfection acid production process. In some embodiments, the system described herein may incorporate one or more reaction tubes into the pre-existing conduit to take advantage of the flow rate and temperature of the pre-existing flow of fluid present in the pre-existing conduit to effect the reaction of the reactants in the one or more reaction tubes. In this way, the “reactor” otherwise necessary for producing the disinfection acid is eliminated without any detrimental effect on the pre-existing conduit or preexisting flow of fluid.

[0027] Furthermore, incorporating the reactor tube into the pre-existing conduit may enable thermal transfer from the reactor tube. For example, if the reactor tube is utilized for the production of performic acid, which is produced in an exothermic reaction, submerging the reaction tube in an existing flow of fluid in a pre-existing conduit enables cooling from the reactor tube to the pre-existing flow of fluid. The volume of water flowing in the pre-existing conduit enables both cooling the reaction tube and affecting the reaction temperature. Conventional disinfection acid production systems, such as systems for producing performic acid, dedicate substantial space, expense, and energy consumption to cooling means, such as heat exchangers. Incorporating the reaction tube in an existing flow of fluid reduces the amount of space necessary for the disinfection acid production system, reduces the energy necessary for producing the disinfection acid, reduces the overall cost of the system, reduces the amount of emissions associated with the system, and reduces reliance on potentially harmful chemicals. Furthermore, since failure or downtime associated with the cooling apparatus in conventional acid production systems prevents using the system for acid production, eliminating the need for such cooling apparatus also eliminates the possibility that the cooling apparatus may fail and disable acid production.

[0028] In some embodiments, the pre-existing conduit includes a wastewater flow and / or a water disinfection stream. As described previously, disinfection acids are commonly used for disinfecting water streams such as those treated at wastewater treatment plants. Wastewater treatment plants often have conduits that have preconditioned water flowing at an initial flow rate and temperature. For example, the water may be preconditioned to enable microbial treatment for the removal of organics. The one or more reaction tubes described herein may be disposed within the wastewater stream to take advantage of the pre-existing temperature conditioning, if present, thereby minimizing any secondary temperature control necessary to generate the disinfection acid. In other embodiments, the wastewater treatment plant may operate at a temperature suitable for the production of the disinfection acid, even without temperature conditioning associated with the pre-existing purpose. Many wastewater treatment plants operate between about 10°C and about 30°C, which is a temperature range suitable for the production of the disinfection acid; performic acid may be produced e.g. at approximately 20°C to 30°C. By incorporating the reaction tube into the wastewater treatment plant, the performic acid may be produced without any secondary cooling. Furthermore, variations in the temperature in the wastewater treatment facility, such as temperatures at about 10°C or about 30°C, may be compensated for by utilizing a longer reaction tube (to account for the slower reaction rate at lower temperatures) or a shorter reaction tube (to account for the swifter reaction rate at higher temperatures).

[0029] In some embodiments, the wastewater stream may have a temperature suitable for the production of the disinfection acid without any secondary heating. In other embodiments, the wastewater stream may have a first intermediate temperature that is greater than an initial reaction tube temperature, but less than the temperature necessary for producing the disinfection acid at the desired concentration and / or flow rate. In these embodiments, the system may include a heating means for heating the one or more reaction tubes to the necessary temperature for the production of the disinfection acid. In some embodiments, the heating means includes a heating jacket, a heating element, or another suitable heating means.

[0030] In some embodiments, the reaction outlet of the at least one reaction tube discharges the disinfection acid into the pre-existing flow of fluid for disinfection of the fluid flow flowing through the pre-existing conduit. For example, when the pre-existing flow of fluid is a wastewater stream, the at least one reaction tube may be configured to produce disinfection acid intended to treat the wastewater stream itself, further increasing the sustainability of the system. Furthermore, in this embodiment, no disinfection acid storage is necessary and the piping necessary for transmission of the disinfection acid is minimized.

[0031] In some embodiments, the system includes a housing in which the at least one reaction tube is disposed. The housing may be configured to permit passage of at least a portion of the pre-existing flow of fluid. The housing may take the form of a protective wall surrounding the at least one reaction tube, but with one or more holes of spaces through which the pre-existing flow of fluid may be permitted to pass through. The housing may take the form of a cage. In some embodiments, the housing includes a screen for filtering particulate matter from the pre-existing flow of fluid before it contacts the at least one reaction tube.

[0032] In embodiments in which the at least one reaction tube is disposed in a closed conduit, the conduit may include a door, access port, window, or other means for accessing the at least one reaction tube inside the conduit to enable cleaning and maintenance.

[0033] In some embodiments, at least one of the one or more conduits includes two or more reaction tube. In some embodiments, each of the two or more reaction tubes is positioned at different positions within the conduit. For example, a first of the two or more reaction tubes may be positioned in the fluid flow proximal to the edge of the conduit, while a second of the two or more reaction tubes may be positioned in the fluid flow proximal to the center of the conduit. The temperature of the flow of fluid in the conduit may vary from the center of the conduit to the edge or circumference of the conduit. For example, when the conduit is a pre-existing conduit and the fluid flow is a pre-existing fluid flow, the pre-existing conduit may be outdoors and therefore subject to the temperature of the environment. In this example, the fluid at the edge or circumference of the conduit may have a temperature that more readily fluctuates with the temperature of the environment, while the fluid at the center of the conduit may have a temperature that is buffered by the surrounding fluid. In this way, the different temperature regimes of the flow of fluid may be utilized to control the temperature of the reaction.

[0034] In some embodiments, the reaction portion of a first of the two or more reaction tubes has a first volume and the reaction portion of a second of the two or more reaction tubes has a second volume different from the first volume. As described above, some pre-existing conduits have temperatures slightly above or slightly below the preferred temperature for disinfectant acid production. By incorporating multiple reaction tubes with different volumes, a different reaction tube may be utilized to account for variations in temperature. For example, a longer reaction tube may be utilized that increases the residence time of the reactants in the reaction portion of the reaction tube, thereby offsetting the reduced reaction rate attributed to lower temperatures. Shorter reaction tubes with lower reactant residence time may be utilized when the temperature is higher.

[0035] In some embodiments, the flow of disinfection acid reactants is configurable to be split between the first reaction tube and the second reaction tube, such as by using a valve for controlling a proportion of disinfection acid reactants entering the first reaction tube and the second reaction tube. By splitting the reactants to one of either the first or second reaction tube, the temperature and concentration of the disinfection acid may be controlled without the need for secondary heating. In some embodiments, the reaction outlet of the first reaction tube is configured to couple with the reaction outlet of the second reaction tube to produce a single disinfection acid discharge stream.

[0036] In some embodiments, the one or more reactant inlets and the reaction outlet are configured to slide into and out of the one or more conduits. In other words, the reaction tube is configured to be positionable between multiple positions within the conduit. For example, the reaction tube may be positionable at a first position near the circumference or edge of the conduit and a second position near the center of the conduit. As described above, the temperature of the flow of fluid in the conduit may vary from the center of the conduit to the edge or circumference of the conduit. By making the one or more reactant inlets and the reaction outlet slidable into and out of the conduit, the reaction tube may be positioned within the flow of fluid at a point where the temperature is most advantageous for enabling disinfection acid production.

[0037] In some embodiments, the one or more reactant inlets include a first reactant inlet for supplying formic acid, optionally with a catalyst such as sulfuric acid, and a second reactant inlet for supplying hydrogen peroxide. Thus, in these embodiments, the disinfection acid includes performic acid, which is the reaction product of formic acid and hydrogen peroxide. The reaction outlet, therefore, is configured to discharge performic acid. In some embodiments, the system includes one or reactant sources. For example, the system may include a reservoir of formic acid and a reservoir of hydrogen peroxide each connected to a reactant inlet for supplying the formic acid and hydrogen peroxide to the reaction portion of the reaction tube within the conduit. Any suitable means for delivering and regulating the delivery of reactants may be utilized, including pumps, valves, actuators, programmable logic controllers, and the like. Furthermore, typical performic acid production systems include a flushing means for flushing unreacted reactants from the reaction tube in between performic acid production cycles. Such flushing means may be included in the systems described herein.

[0038] FIG. 1 depicts a system 100 for producing disinfection acid including a conduit 102 having a fluid flow inlet 104 for receiving a flow of fluid 106, and a fluid flow outlet 108 for discharging the flow of fluid 106. A reaction tube 110 is disposed within conduit 102, the reaction tube 110 including a reaction portion 112, one or more reactant inlets 114, and a reaction outlet 116.

[0039] FIG. 2 depicts a system 200 for producing disinfection acid including a conduit 202. Conduit 202 is depicted as a pre-existing conduit having a pre-existing fluid flow, i.e., a conduit and fluid flow that serves a purpose other than the one described herein, such as a wastewater treatment conduit or the like. Conduit 202 has a fluid flow inlet 204 for receiving a flow of fluid 206, and a fluid flow outlet 208 for discharging the flow of fluid 206. A reaction tube 210 is disposed within conduit 202, the reaction tube 210 including a reaction portion 212, one or more reactant inlets 214, and a reaction outlet 216.

[0040] FIG. 3 depicts a system 300 for producing disinfection acid having a first reaction tube 302 positioned near the edge of conduit 304 and a second reaction tube 306 positioned near the center of conduit 304. FIG. 4 depicts a system 400 for producing disinfection acid having a reaction tube 402 configured to slide from a first position near the circumference of conduit 404 to a second position near the center of conduit 404.

[0041] FIG. 5 depicts a system 500 for producing disinfection acid having a conduit 502, a first reaction tube 504 having a first length, and a second reaction tube 506 having a second length longer than the first length. As described above, reactants may be selectively proportioned to the two reaction tubes depending on the temperature of the fluid flowing through the conduit; longer reaction tubes may account for a lower temperature in the fluid flowing through the conduit while shorter reaction rubes may account for a higher temperature in the fluid flowing through the conduit.

[0042] FIGS. 6A-6C depict three exemplary reaction tube shapes: a three-dimensional helical coil 602, a straight pipe 604, and a two-dimensional coil 606. These reaction tube shapes are merely exemplary and alternative shapes may be implemented depending on the available space, the desired thermal characteristics, etc. Furthermore, although each of Figures 1-5 are depicted as having helical coil-shaped reaction tubes, any one of the reaction tubes in these figures may take the form of a straight pipe, two-dimensional coil, or another shape.

[0043] Methods for Producing Disinfection Acid

[0044] Methods for producing disinfection acid are also disclosed herein. In one aspect, a method includes providing any one of the systems as described herein. In another aspect, a method include providing one or more conduits, each conduit having a fluid flow inlet, and a fluid flow outlet. In some embodiments, each of the one or more conduits provided by the method include at least one reaction tube, each of the reaction tubes including a reaction portion having a volume, one or more reactant inlets, and a reaction outlet. The method may include supplying fluid through the fluid flow inlet to form a flow of fluid, the fluid having a temperature and a flow rate.

[0045] In some embodiments, the method includes supplying one or more disinfection acid reactants through the one or more reactant inlets such that the one or more disinfection acid reactants react in the reaction portion to form the disinfection acid. In some embodiments, the method includes discharging the disinfection acid through the reaction outlet. In some embodiments, the volume of the reaction portion, the temperature of the fluid, and the flow rate of the fluid are configured to produce a concentration of disinfection acid. As described above, the disinfection acid is generally produced through an equilibrium reaction that may be controlled by the flow rate of reactants (by way of the reaction portion volume), the temperature of the fluid (which influences the reaction temperature by the heating / cooling of the reaction tube in the flow of fluid), and the flow rate of the fluid (which also influences the reaction temperature).

[0046] In some embodiments, the method may include heating the reaction portion to a temperature suitable for the production of the disinfection acid. The heating means may act directly on the reaction portion, such as through the use of a heating jacket secured to at least a portion of the reaction portion. The heating means may act on the fluid flowing through the conduit, such as by heating the fluid before it enters the conduit or before it enters the fluid flow conduit portion of the pipe. Any suitable heating means may be utilized.

[0047] In some embodiments, the method includes utilizing at least one conduit that is a preexisting conduit so that the fluid flow inlet of the pre-existing conduit is a pre-existing flow of fluid. In other words, the conduit and fluid flow therein may have a pre-existing purpose other than as part of the systems and methods described herein, such as being part of a wastewater treatment plant or other industrial process.

[0048] In some embodiments, the method includes discharging the disinfection acid through the reaction outlet and introducing the disinfection acid into the flow of fluid that is present in the conduit. In this way, the method advantageously increases sustainability of the disinfection acid production by producing the disinfection acid in the very same fluid it is intended to disinfect. In some embodiments, the reaction tube is incorporated within the pre-existing conduit proximal to the location where the disinfection acid is introduced into the fluid flow. In other embodiments, the reaction tube is incorporated within the pre-existing conduit at a location more remote from where the disinfection acid is introduced. In some embodiments, the pre-existing conduit may have a serpentine construction so that the reaction tube is incorporated within the pre-existing conduit at a first location and the introduction of disinfection acid occurs at a second location that is substantially “downstream” from the first location but is physically positioned proximal to the first location by virtue of the serpentine shape of the pre-existing conduit.

[0049] In some embodiments, supplying the one or more disinfection acid reactants includes supplying formic acid through a first reactant inlet and supplying hydrogen peroxide through a second reactant inlet. Thus, reacting the one or more disinfection acid reactants includes forming performic acid.

[0050] In some embodiments, the method includes providing two or more reaction tubes in at least one of the one or more conduits. In some embodiments, the method includes supplying a first amount of the one or more disinfection acid reactants to a first reaction tube having a first volume and supplying a second amount of the one or more disinfection acid reactants to a second reaction tube having a second volume that is different from the first volume. As described above, the volume of the reaction tube controls, at least in part, the concentration of disinfection acid produced in the reaction tube. By utilizing two reaction tubes each having a different volume, the concentration of disinfection acid produced by the method may be tuned to the specific application. In some embodiments, the method includes actuating a valve or other means for portioning the disinfection acid reactants to the first and second reaction tubes.

[0051] In some embodiments, the system provided by the method includes one or more reactant inlets and reaction outlet that are configured to shift or slide into and out of the one or more conduits so that the at least one reaction tube is configured to shift or slide from a first position in the center of the conduit to a second position proximal to the circumference of the conduit. As described above, the temperature of the flow of fluid in the conduit may vary from the center of the conduit to the edge or circumference of the conduit. By providing a system with the ability to shift the reaction tube to different radial positions within the conduit each having a different temperature regime, the temperature of the reaction may be controlled without the need for secondary temperature control.

[0052] ASPECTS

[0053] The following is a non-limiting listing of aspects of the disclosure.

[0054] Aspect 1. A system for producing disinfection acid, the system comprising, consisting of, or consisting essentially of one or more conduits comprising, consisting of, or consisting essentially of a fluid flow inlet for receiving a flow of fluid and a fluid flow outlet for discharging the flow of fluid; and at least one reaction tube disposed in each of the one or more conduits such that the flow of fluid contacts the at least one reaction tube, each of the at least one reaction tubes comprising, consisting of, or consisting essentially of a reaction portion, one or more reactant inlets for receiving one or more disinfection acid reactants, and a reaction outlet for discharging the disinfection acid, each reaction portion having a volume configured to produce a concentration of disinfection acid.

[0055] Aspect 2. The system of Aspect 1, wherein the at least one reaction tube is in the form of a straight pipe or circular coil.

[0056] Aspect 3. The system of Aspect 1, wherein at least one of the one or more conduits is a pre-existing conduit, the fluid flow inlet of the pre-existing conduit is configured to receive the flow of fluid, and the flow of fluid is a pre-existing flow of fluid.

[0057] Aspect 4. The system of Aspect 3, wherein the pre-existing flow of fluid comprises a wastewater flow or a water disinfection stream.

[0058] Aspect 5. The system of Aspect 4 wherein the pre-existing flow of fluid has a temperature suitable for the production of the disinfection acid.

[0059] Aspect 6. The system of Aspect 4, further comprising, consisting of, or consisting essentially of a heating means for heating the one or more reaction tubes to a temperature suitable for the production of the disinfection acid, wherein the pre-existing flow of water has a first intermediate temperature greater than an initial reaction tube temperature but less than the temperature suitable for the production of the disinfection acid.

[0060] Aspect 7. The system of Aspect 3, wherein the reaction outlet of the at least one reaction tube discharges the disinfection acid into the pre-existing flow of fluid for disinfection of the fluid flow flowing through the pre-existing conduit.

[0061] Aspect 8. The system of Aspect 3, wherein the disinfection acid produced by the system is configured to disinfect the pre-existing flow of fluid.

[0062] Aspect 9. The system of Aspect 3, further comprising, consisting of, or consisting essentially of a housing in which the at least one reaction tube is disposed, wherein the housing is configured permit passage of at least a portion of the pre-existing flow of fluid.

[0063] Aspect 10. The system of Aspect 9, wherein the housing further comprises a screen for filtering particulate matter before the pre-existing flow of fluid contacts the at least one reaction tube.

[0064] Aspect 11. The system of Aspect 1, wherein at least one of the one or more conduits comprises two or more reaction tubes, wherein a flow of disinfection acid reactants is configurable to be split between the first reaction tube and the second reaction tube.

[0065] Aspect 12. The system of Aspect 11, wherein a first of the two or more reaction tubes is positioned in the fluid flow proximal to an edge of the conduit, and a second of the two or more reaction tubes is positioned in the fluid flow proximal to a center of the conduit.

[0066] Aspect 13. The system of Aspect 8, wherein the reaction portion of a first of the two or more reaction tubes has a first volume and the reaction portion of a second of the two or more reaction tubes has a second volume that is different from the first volume.

[0067] Aspect 14. The system of Aspect 11, wherein the reaction outlet for the first reaction tube is configured to couple with the reaction outlet for the second reaction tube to produce a single disinfection acid discharge stream.

[0068] Aspect 15. The system of Aspect 11, further comprising, consisting of, or consisting essentially of a valve for controlling a proportion of disinfection acid reactants entering the first reaction tube and the second reaction tube.

[0069] Aspect 16. The system of Aspect 1, wherein the one or more reactant inlets and the reaction outlet are configured to slide into and out of the one or more conduits so that the at least one reaction tube is configured to shift from a position in the center of the conduit to a position proximal to an edge of the conduit.

[0070] Aspect 17. The system of Aspect 1, wherein the one or more reactant inlets comprises a first reactant inlet for supplying formic acid and a second reactant inlet for supplying hydrogen peroxide, and wherein the disinfection acid comprises performic acid.

[0071] Aspect 18. A method for forming a disinfection acid, the method comprising, consisting of, or consisting essentially of: providing one or more conduits comprising, consisting of, or consisting essentially of a fluid flow inlet and a fluid flow outlet, wherein each of the one or more conduits comprise at least one reaction tube, wherein each of the at least one reaction tubes comprise a reaction portion having a volume, one or more reactant inlets, and a reaction outlet, supplying fluid through the fluid flow inlet to form a flow of fluid, wherein the fluid has a temperature and a flow rate, supplying one or more disinfection acid reactants through the one or more reactant inlets such that the one or more disinfection acid reactants react in the reaction portion to form the disinfection acid, and discharging the disinfection acid through the reaction outlet, wherein the volume of the reaction portion, the temperature of the fluid, and the flow rate of the fluid are configured to produce a concentration of disinfection acid.

[0072] Aspect 19. The method of Aspect 18, further comprising, consisting of, or consisting essentially of heating the reaction portion.

[0073] Aspect 20. The method of Aspect 18, wherein at least one of the one or more conduits is a pre-existing conduit, the fluid flow inlet of the pre-existing conduit is configured to receive the flow of fluid, and the flow of fluid is a pre-existing flow of fluid.

[0074] Aspect 21. The method of Aspect 20, wherein discharging the disinfection acid through the reaction outlet comprises discharging the disinfection acid into the pre-existing flow of fluid so as to disinfect the fluid.

[0075] Aspect 22. The method of Aspect 18, wherein supplying the one or more disinfection acid reactants comprises supplying formic acid through a first reactant inlet and supplying hydrogen peroxide through a second reactant inlet, and wherein reacting the one or more disinfection acid reactants comprises forming performic acid.

[0076] Aspect 23. The method of Aspect 18, wherein at least one of the one or more conduits comprises at least two or more reaction tubes, and wherein supplying the one or more disinfection acid reactants comprises supplying a first reaction tube with a first amount of disinfection acid reactants and supplying a second reaction tube with a second amount of disinfection acid reactants.

[0077] Aspect 24. The method of Aspect 23, wherein the first reaction tube has a first volume and the second reaction tube has a second volume that is different from the first volume.

[0078] Aspect 25. The method of Aspect 18, wherein the one or more reactant inlets and the reaction outlet are configured to shift into and out of the one or more conduits so that the at least one reaction tube is configured to shift from a position in a center of the conduit to a position proximal to an edge of the conduit, and wherein reacting the one or more disinfection acid reactants further comprises shifting the at least one reaction tube to a position within the one or more conduits having a temperature suitable for the formation of the disinfection acid.

[0079] While the disclosure has been described with reference to a number of embodiments, it will be understood by those skilled in the art that the disclosure is not limited to such disclosed embodiments. Rather, the disclosure can be modified to incorporate any number of variations, alterations, substitutions, or equivalent arrangements not described herein, but which are commensurate with the spirit and scope of the disclosure. Conditional language used herein, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, generally is intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements or functional 5 capabilities. Additionally, while various embodiments of the disclosure have been described, it is to be understood that aspects of the disclosure may include only some of the described embodiments. Accordingly, the disclosure is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.

Claims

1. A system for producing disinfection acid, the system comprising:one or more conduits comprising a fluid flow inlet for receiving a flow of fluid and a fluid flow outlet for discharging the flow of fluid; andat least one reaction tube disposed in each of the one or more conduits such that the flow of fluid contacts the at least one reaction tube, each of the at least one reaction tubes comprising a reaction portion, one or more reactant inlets for receiving one or more disinfection acid reactants, and a reaction outlet for discharging the disinfection acid, each reaction portion having a volume configured to produce a concentration of disinfection acid.

2. The system of claim 1, wherein the at least one reaction tube is in the form of a straight pipe or circular coil.

3. The system of claim 1, wherein at least one of the one or more conduits is a pre-existing conduit, the fluid flow inlet of the pre-existing conduit is configured to receive the flow of fluid, and the flow of fluid is a pre-existing flow of fluid.

4. The system of claim 3, wherein the pre-existing flow of fluid comprises a wastewater flow or a water disinfection stream.

5. The system of claim 3, wherein the reaction outlet of the at least one reaction tube discharges the disinfection acid into the pre-existing flow of fluid for disinfection of the fluid flow flowing through the pre-existing conduit.

6. The system of claim 1, further comprising a housing in which the at least one reaction tube is disposed, wherein the housing is configured permit passage of at least a portion of the pre-existing flow of fluid.

7. The system of claim 1, wherein at least one of the one or more conduits comprises two ormore reaction tubes,wherein a flow of disinfection acid reactants is configurable to be split between the first reaction tube and the second reaction tube.

8. The system of claim 7, wherein the reaction outlet for the first reaction tube is configured to couple with the reaction outlet for the second reaction tube to produce a single disinfection acid discharge stream.

9. The system of claim 1, wherein the one or more reactant inlets and the reaction outlet are configured to slide into and out of the one or more conduits so that the at least one reaction tube is configured to shift from a position in the center of the conduit to a position proximal to an edge of the conduit.

10. A method for forming a disinfection acid, the method comprising:providing one or more conduits comprising a fluid flow inlet and a fluid flow outlet, wherein each of the one or more conduits comprise at least one reaction tube, wherein each of the at least one reaction tubes comprise a reaction portion having a volume, one or more reactant inlets, and a reaction outlet,supplying fluid through the fluid flow inlet to form a flow of fluid, wherein the fluid has a temperature and a flow rate,supplying one or more disinfection acid reactants through the one or more reactant inlets such that the one or more disinfection acid reactants react in the reaction portion to form the disinfection acid, anddischarging the disinfection acid through the reaction outlet,wherein the volume of the reaction portion, the temperature of the fluid, and the flow rate of the fluid are configured to produce a concentration of disinfection acid.

11. The method of claim 10, wherein at least one of the one or more conduits is a pre-existing conduit, the fluid flow inlet of the pre-existing conduit is configured to receive the flow of fluid, and the flow of fluid is a pre-existing flow of fluid.

12. The method of claim 11, wherein discharging the disinfection acid through the reaction outlet comprises discharging the disinfection acid into the pre-existing flow of fluid so as to disinfect the fluid.

13. The method of claim 10, wherein supplying the one or more disinfection acid reactants comprises supplying formic acid through a first reactant inlet and supplying hydrogen peroxide through a second reactant inlet, andwherein reacting the one or more disinfection acid reactants comprises forming performic acid.

14. The method of claim 10, wherein at least one of the one or more conduits comprises at least two or more reaction tubes, andwherein supplying the one or more disinfection acid reactants comprises supplying a first reaction tube with a first amount of disinfection acid reactants and supplying a second reaction tube with a second amount of disinfection acid reactants.

15. The method of claim 10, wherein the one or more reactant inlets and the reaction outlet are configured to shift into and out of the one or more conduits so that the at least one reaction tube is configured to shift from a position in a center of the conduit to a position proximal to an edge of the conduit, andwherein reacting the one or more disinfection acid reactants further comprises shifting the at least one reaction tube to a position within the one or more conduits having a temperature suitable for the formation of the disinfection acid.

Images