Patent Publication Number: US-11655581-B2

Title: Washing systems

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. Non-provisional application Ser. No. 16/321,390, filed Jan. 28, 2019, now allowed, which is a U.S. National Stage Entry of International Application No. PCT/US2017/046349, filed Aug. 10, 2017, which claims the benefit of and priority to U.S. Provisional Application No. 62/373,191, filed Aug. 10, 2016, each of which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE PRESENT DISCLOSURE 
     The present disclosure relates generally to washing systems, and more particularly, to washing systems including a recirculation line with an integrated fluid sanitizer module. 
     BACKGROUND 
     In industrial laundry applications, tunnel washing systems are often used to clean large volumes of soiled laundry (e.g., clothes, linens, fabrics, or the like). Typically, soiled laundry is placed into a loading hopper of a wash tunnel and is then moved through a series of zones or cycles, including a pre-wash zone, a main wash zone, and a rinse zone. After the laundry exits the rinse zone, a press then removes excess water from the laundry prior to moving the laundry to a dryer. Within each zone, chemicals and fresh water (collectively, “wash water”) is added to perform a desired cleaning operation. As the wash water flows through each zone and contacts the soiled laundry, the wash water may be contaminated by bacteria, viruses, algae, mold, fungi, or the like from the soiled laundry. As a result, soiled wash water is then removed from each zone via a drain and exits the system as waste. In an effort to reduce waste water, soiled wash water can be recirculated within the washing system. However, recirculation of soiled wash water leads to acceleration growth of bacteria, viruses, algae, mold, fungi, or the like in the wash water. 
     In addition, the pH of the wash water in each of the various zones must be controlled to effectively and efficiently clean the soiled laundry. For example, the pH of the wash water at the beginning of the main wash zone can be about 10.5, while the pH of the wash water at the end of the rinse zone can be between about 5 and 6. To achieve this difference in pH, chemicals are introduced into each of the zones or cycles to raise or lower the pH as required. Continually adding these chemicals to achieve a desired pH level adds to the costs of operating the tunnel washing system. 
     The present disclosure addresses these and other problems. 
     SUMMARY 
     According to some implementations of the present disclosure, a washing system includes a housing, a drain line, and a recirculation line. The housing is configured to receive, via a fluid inlet, fresh water during one or more wash cycles of a wash session. The drain line is coupled to the housing and includes a valve, and the drain line is configured to receive soiled water from the housing during the wash session. The recirculation line is coupled to and extends from the valve of the drain line and is configured to receive a portion of the soiled water via the valve. The recirculation line includes an integrated fluid sanitizer module configured to at least partially sanitize the portion of the soiled water, and the recirculation line is configured to deliver sanitized water from the integrated fluid sanitizer module to the fluid inlet of the housing. 
     According to some implementations of the present disclosure, a tunnel washing system includes a housing, a press, and a recirculation line. The housing includes a pre-wash zone, a main wash zone, and a rinse zone. The main wash zone includes a first fluid inlet and a first fluid outlet, and the rinse zone includes a second fluid inlet and a second fluid outlet. The press is coupled to a press tank which is configured to receive and store therein soiled press water. The recirculation line is coupled to the press tank and is configured to receive a portion of the soiled press water. The recirculation line includes an integrated fluid sanitizer module configured to at least partially sanitize the portion of the soiled press water. 
     The above summary of the present disclosure is not intended to represent each embodiment, or every aspect, of the present disclosure. Additional features and benefits of the present disclosure are apparent from the detailed description and figures set forth below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic illustration of a washing system according to some implementations of the present disclosure; 
         FIG.  2    is a partial cross-sectional view of an integrated fluid sanitizer module of the tunnel washing system of  FIG.  1    according to some implementations of the present disclosure; 
         FIG.  3    is a schematic illustration of a tunnel washing system according to some implementations of the present disclosure; 
         FIG.  4 A  is a plot of the pH of pre-wash zone water, wash zone water, rinse zone water, and press water in a first washing system according to some implementations of the present disclosure; and 
         FIG.  4 B  is a plot of the pH of pre-wash zone water, wash zone water, rinse zone water, and press water in a second washing system according to some implementations of the present disclosure. 
     
    
    
     While the present disclosure is susceptible to various modifications and alternative forms, specific embodiments and implementations are shown by way of example in the drawings and are described in detail herein. It should be understood, however, that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the disclosure is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the disclosure. 
     DETAILED DESCRIPTION 
     Referring to  FIG.  1   , a washing system  100  includes a housing  102 , a controller  108 , a fresh water reservoir or tank  150 , a chemical reservoir or tank  154 , a drain line  160 , and a recirculation line  170 . Generally, the washing system  100  is used for performing one or more wash sessions to clean soiled laundry (e.g., clothes, linens, fabrics, or the like). 
     A loading hopper or inlet (not shown) of the housing  102  receives soiled laundry to be cleaned during a given wash session, and can be a residential washer or a commercial tunnel washer (e.g.,  FIG.  2   ). As shown, the housing  102  includes a fluid inlet  104  and a fluid outlet  106 . The fluid inlet  104  is coupled to the fresh water reservoir or tank  150  and the chemical reservoir or tank  154  (e.g., via a metal pipe, a PVC pipe, a hose, or the like) such that the housing  102  receives fresh water from the fresh water reservoir or tank  150  and chemicals from the chemical reservoir or tank  154  for use during the wash session. The fluid inlet  104 , the fresh water reservoir or tank  150 , the chemical reservoir or tank  154 , or any combination thereof can include one or more valves (not shown) for use in controlling the volume of fresh water and/or chemicals that flow into the housing  102 . The chemical reservoir or tank  154  stores one or more chemicals for use during the wash session, such as, for example, detergent, bleach, alkalis, sours, solvents, hydrogen peroxide, paracetic acid, mineral spirits, or the like, or any combination thereof. 
     Each wash session includes one or more cycles, including, for example, a pre-wash cycle  110 , a main wash cycle  120 , a rinse cycle  130 , and press/spin cycle  140 . At the beginning of each of the one or more cycles, the housing  102  receives fresh water from the fresh water reservoir or tank  150  and/or chemicals from the chemical reservoir or tank  154  via the fluid inlet  104  (collectively, “wash water”). The wash water contacts the soiled laundry in the housing  102  for a predetermined cycle time (e.g., between about one minute and about sixty minutes, between about three minutes and about six minutes, between about six minutes and about twelve minutes, between about five minutes and about ten minutes, etc.). In some implementations, the housing  102  rotates or oscillates to agitate the soiled laundry to mix the soiled laundry with the wash water. 
     More specifically, the optional pre-wash cycle  110  is used to remove large debris from the soiled laundry prior to the main wash cycle  120 . During the main wash cycle  120 , chemicals are used to clean the soiled laundry (e.g., remove debris, dirt, stains and at least partially sanitize). Fresh water and/or chemicals are then used during the rinse cycle  130  to remove residual wash water from the main wash cycle  120  and the optional pre-wash cycle  110 . During the optional press/spin cycle  140 , excess water from the rinse cycle  130  is removed from the cleaned laundry to reduce the required drying time. The excess water can be removed during the optional press/spin cycle  140  by pressing or compressing the cleaned laundry to expel the excess water, or by spinning the cleaned laundry to create centrifugal forces that expel the excess water. 
     Soiled wash water is drained from the housing  102  via the fluid outlet  106 . The soiled wash water can be drained before each of the cycles of the wash session, during each of the cycles of the wash session, after each of the cycles of the wash session, or any combination thereof. The drain line  160  is coupled to the fluid outlet  106 , receives the soiled wash water, and delivers the soiled wash water to a main drain  164  (e.g., a sewage or waste water line). The drain line  160  includes a drain valve  162  upstream of the main drain  164  that is coupled to the recirculation line  170 . Instead of permitting all of the soiled wash water in the drain line  160  to flow into the main drain  164 , the drain valve  162  selectively diverts a portion of the soiled wash water received by the drain line  160  to the recirculation line  170  (e.g., between about 30 percent and about 50 percent of the soiled water received by the drain line  160 ). 
     The recirculation line  170  includes a pump  172 , an integrated fluid sanitizer module  180 , and an optional storage tank  174 . A first end of the recirculation line  170  is coupled to the drain valve  162  and a second end of the recirculation line  170  is coupled to the fluid inlet  104  of the housing  102 . As shown, the pump  172  is positioned upstream of the integrated fluid sanitizer module  180  and the fluid inlet  104  to force the predetermined volume of the soiled water to flow through the recirculation line  170 . The recirculation line  170  can be a metal pipe (e.g., copper, stainless steel, or the like), a PVC pipe, a hose, or the like, or any combination thereof. 
     As shown in  FIG.  2   , the integrated fluid sanitizer module  180  is generally used to at least partially sanitize the soiled wash water in the recirculation line  170  and includes an oxidative gas generator  182 , a manifold  192 , and a counter-flow mixer  194 . The oxidative gas generator  182  is used to produce a volume of o-zone gas and includes a first lamp housing  184   a  and a second lamp housing  184   b . The first lamp housing  184   a  includes a first gas inlet  186   a  and a first ultra-violet (“UV”) lamp  188   a  disposed therein. Similarly, the second lamp housing  184   b  includes a second gas inlet  186   b  and a second UV lamp  188   b  disposed therein. The first and second gas inlets  186   a ,  186   b  permit ambient air to enter each of the respective lamp housings  184   a ,  184   b  and to flow past each respective UV lamp  188   a ,  188   b . When powered by a power source (not shown), the first and second UV lamps  188   a ,  188   b  emit a wavelength of light between about 100 nm and about 500 nm. 
     When ambient air enters the first gas inlet  186   a  and the second gas inlet  186   b  and flows past the first UV lamp  188   a  and the second UV lamp  188   b  while both are emitting a wavelength of light of between about 180 nm and about 260 nm (e.g., about 187 nm), the wavelength of light breaks down oxygen molecules (O 2 ) from the ambient air into oxygen atoms (O). These oxygen atoms then react with other oxygen (O 2 ) molecules in the ambient air to produce the volume of o-zone gas (O 3  molecules). O-zone is a pale blue gas with a distinctively pungent smell and is a powerful disinfectant, oxidant, and deodorizer. 
     In some implementations, the oxidative gas generator  182  can include an optional fan (not shown) to aid in forcing ambient air through the gas inlet  186  to produce the volume of o-zone gas. While the oxidative gas generator  182  is shown as having two lamp housings  184   a  and  184   b  and two UV lamps  188   a  and  188   b , the oxidative gas generator  182  can include any number of lamp housings and/or UV lamps (e.g., one UV lamp, four UV lamps, etc.). In other implementations, the integrated fluid sanitizer module  180  includes an oxidative gas generator that does not include a UV lamp and produces the volume of o-zone gas using any other suitable mechanism (e.g., corona discharge). Alternatively, the integrated fluid sanitizer module  180  can include an o-zone gas storage tank (not shown) filled with o-zone gas and/or an oxygen storage tank (not shown) filled with oxygen gas. In such implementations, the oxygen storage tank can be used in conjunction with the oxidative gas generator  182  described above to deliver oxygen gas through the first and second gas inlets  186   a ,  186   b  to increase the production of o-zone gas. 
     Once produced by the oxidative gas generator  182 , the volume of o-zone is delivered to the manifold  192  via a gas delivery line  190 . The gas delivery line  190  can be a metal pipe, a PVC pipe, a hose, or the like, or any combination thereof. The manifold  192  can be a venturi injector (with or without a bypass manifold), a mixing valve, a diffuser, an aeration system, or the like, or any combination thereof. When the volume of o-zone gas reaches the manifold  192 , the volume of o-zone gas is mixed with and at least partially sanitizes the soiled wash water in the recirculation line  170  as it flows through the manifold  192 . 
     O-zone gas sanitizes by killing and/or inactivating microorganisms (e.g., bacteria, viruses, algae, mold, fungi, or the like), and can be many times more effective than chemicals. For example, o-zone gas can be approximately 150% more effective than chlorine and reacts over 3,000 times faster. O-zone gas is also advantageous because its chemical reactions do not leave any harmful byproducts. Because of its high oxidation potential, o-zone gas can precipitate a variety of organic and inorganic contaminates, including, for example, iron, manganese, sulfides, metals, body oils, sweat, and saliva. Further, o-zone gas oxidizes organic chemicals that are responsible for producing undesirable odors. 
     Advanced oxidative processes (often referred to as “AOP&#39;s”) are a set of chemical treatment procedures designed to remove organic and/or inorganic materials in water using hydroxyl radicals (*OH). Generally, the chemistry in AOP&#39;s can be divided into three parts: (1) formation of hydroxyl radicals, (2) initial attacks by the hydroxyl radicals on target molecules, breaking the target molecules into fragments, and (3) subsequent attacks by hydroxyl radicals until ultimate mineralization. One subset of AOP chemical processes that produce hydroxyl radicals employs o-zone gas. First, o-zone gas (O 3 ) reacts with a hydroxyl ion (HO − ) to yield HO 2   −  and O 2  (oxygen). Next, a second o-zone molecule (O 3 ) reacts with the HO 2   −  produced in the previous step to yield HO 2  and O 3   −  (an ozonide radical). The ozonide radical (O 3 ) then reacts with H +  to yield HO 3   − . Finally, the HO 3   −  produced during the previous step yields a hydrogen radical (*OH) and an oxygen molecule (O 2 ) upon protonation. 
     The hydroxyl radical is often referred to as the “detergent” of the troposphere because it reacts with many pollutants, decomposing them through “cracking”, often acting as the first step to their removal. It also has an important role in eliminating some greenhouse gases like methane and ozone. The rate of reaction with the hydroxyl radical often determines how long many pollutants last in the atmosphere, if they do not undergo photolysis or are rained out. For instance methane, which reacts relatively slowly with hydroxyl radical, has an average lifetime of less than five years, and many CFCs have lifetimes of 50 years or more. Pollutants, such as larger hydrocarbons, can have very short average lifetimes of less than a few hours. The hydroxyl radicals first reaction with many volatile organic compounds (often referred to as “VOC&#39;s”) having a chemical formula of RH, is the removal of a hydrogen atom, forming water (H 2 O) and an alkyl radical (R*). The alkyl radical will typically react rapidly with oxygen (O 2 ) forming a peroxy radical (RO*2). The fate of this radical in the troposphere is dependent on factors such as the amount of sunlight, pollution in the atmosphere and the nature of the alkyl radical that formed it. 
     AOP&#39;s that form hydroxyl radicals are advantageous in the field of water treatment for a number of reasons. For example, hydroxyl radicals can effectively eliminate organic compounds in aqueous phase, rather than collecting or transferred pollutants into another phase. Due to the high reactivity of hydroxyl radicals, they react with almost every aqueous pollutant without discriminating, thereby allowing many organic contaminates to be removed at the same time. Hydroxyl radicals can also remove some heavy metals in the form of precipitated M(OH) x . Because the complete reduction product of hydroxyl radicals is H 2 O, AOP&#39;s do not introduce any new hazardous substances into the water. 
     As shown in  FIG.  2   , the counter-flow mixer  194  of the integral fluid sanitizer module  180  is positioned downstream of the manifold  192 . The counter-flow mixer  194  includes a first portion  194   a  and a second portion  194   b  positioned downstream of the first portion  194   a . Due to this geometry, water in the recirculation line  170  flows into the first portion  194   a  and then into the second portion  194   b . The first portion  194   a  includes a first sanitizing lamp  196   a  disposed therein and the second portion  194   b  includes a second sanitizing lamp  196   b  disposed therein. When powered by a power source (not shown), the first sanitizing lamp  196   a  emits a first sanitizing wavelength of light and the second sanitizing lamp  196   b  emits a second sanitizing wavelength of light. These sanitizing wavelengths of light kill and/or inactivate microorganisms and can range between about 10 nm and about 400 nm. Preferably, the first and second sanitizing wavelengths of light are about 254 nm, which is commonly referred to as “germicidal ultra-violet light”. 
     As water enters the first portion  194   a  of the counter-flow mixer  194 , the water flows past the first sanitizing lamp  196   a . The first sanitizing wavelength of light emitted by the first sanitizing lamp  196   a  sanitizes the water by killing and/or inactivating microorganisms and reacts with the volume of o-zone gas injected in the manifold  192  to convert O 3  molecules into hydroxyl radicals. The water then flows from the first portion  194   a  into the second portion  194   b  and flows past the second sanitizing lamp  196   b . Like the first sanitizing wavelength of light, the second sanitizing wavelength of light emitted by the second sanitizing lamp  196   b  sanitizes the water and produces hydroxyl radicals by reacting with O 3  molecules. The geometry and flow pattern of the counter-flow mixer  194  causes press changes and turbulence in the water to increase the chemical reactions between the o-zone gas, the water, and the sanitizing wavelengths of light emitted by the first and second sanitizing lamps  196   a ,  196   b . Sanitized water then exits the second portion  194   b  of the counter-flow mixer  194  and continues along the recirculation line  170  towards the optional storage tank  174  and the fluid inlet  104  ( FIG.  1   ). 
     While the counter-flow mixer  194  is shown and described herein as including a first sanitizing lamp  196   a  and a second sanitizing lamp  196   b , the counter-flow mixer  194  can include any number of sanitizing lamps (e.g., one sanitizing lamp, four sanitizing lamps, ten sanitizing lamps, etc.). In some implementations, the integrated fluid sanitizer module  180  does not include a counter-flow mixer and instead includes one or more sanitizing lamps at least partially disposed within the recirculation line  170 . 
     In some implementations, the integrated fluid sanitizer module  180  includes a chemical feed line (not shown) that is coupled to the chemical reservoir or tank  154 . The chemical feed line delivers chemicals into the recirculation line  170  to further aid in sanitizing the soiled wash water. The chemical feed line of the integrated fluid sanitizer module  180  can include one or more pumps (not shown) and/or valves (not shown) to control the flow of chemicals into the recirculation line  170 . For example, the chemical feed line can deliver hydrogen peroxide into the recirculation line  170  (e.g., upstream of the manifold  192  and/or the counter-flow mixer  194 ). Hydrogen peroxide, which has a chemical formula of H 2 O 2 , is the simplest peroxide (i.e., a compound with an oxygen-oxygen single bond) and is often used as a weak oxidizer, bleaching agent, and disinfectant. For safety reasons, hydrogen peroxide is often handled as a dilute solution, rather than in its pure form. 
     In addition to producing hydroxyl radicals using o-zone gas, AOP&#39;s can employ hydrogen peroxide and ultra-violet light to produce hydroxyl radicals. When exposed to a wavelength of ultra-violet light (e.g., light having a wavelength between about 150 nm and about 250 nm), hydrogen peroxide yields hydroxyl radicals, which as described above, act as a sanitizing agent. Specifically, the ultra-violet wavelength of light causes hemolytic bond cleavage of the oxygen bond of one H 2 O 2 , molecule, resulting in the formation of two hydroxyl radicals. In this manner, injecting hydrogen peroxide into the recirculation line  170  such that it is exposed to the sanitizing wavelengths of light of the first and second sanitizing lamps  196   a ,  196   b  can force an AOP and produce hydroxyl radicals. Further, as described above, hydrogen peroxide is one of the chemicals that can be used in the one or more wash cycles (e.g., during the main wash cycle  120 ) as a bleaching agent and/or disinfectant. Thus, hydrogen peroxide may already be present in the soiled wash water in the recirculation line  170  and can force additional AOP&#39;s to Referring to  FIG.  1   , sanitized water in the recirculation line  170  downstream of the integrated fluid sanitizer module  180  is delivered to the fluid inlet  104  of the housing  102  by use of the pump  172 , or one or more additional pumps (not shown) for use in the wash session. In this manner, soiled wash water from any one of the one or more wash cycles can be sanitized and reused in a different one of the one or more wash cycles of the same wash session. For example, the recirculation line  170  can receive soiled wash water via the drain line  160  and drain valve  162  subsequent to the optional pre-wash cycle  110 , sanitize the soiled wash water using the integrated fluid sanitizer module  180 , and deliver sanitized water to the fluid inlet  104  for use during the main wash cycle  120 , the rinse cycle  130 , or the optional press/spin cycle  140 . Likewise, the recirculation line  170  can receive soiled wash water via the drain line  160  and drain valve  162  subsequent to the main wash cycle  120 , sanitize the soiled wash water using the integrated fluid sanitizer module  180 , and deliver sanitized water to the fluid inlet  104  for use during the rinse cycle  130  or the optional press/spin cycle  140 . In addition, the recirculation line  170  can receive soiled wash water via the drain line  160  and drain valve  162  subsequent to the rinse cycle  130 , sanitize the soiled wash water using the integrated fluid sanitizer module  180 , and deliver sanitized water to the fluid inlet  104  for use during the optional press/spin cycle  140 . 
     In some implementations, the recirculation line  170  includes an optional storage tank  174  positioned downstream of the integrated fluid sanitizer module  180  that receives and stores the sanitized water from the integrated fluid sanitizer module  180 . In such implementations, the sanitized water can be delivered from the optional storage tank  174  to the fluid inlet  104  of the housing  102  for use in the wash session or a second wash session. For example, the recirculation line  170  can receive soiled wash water subsequent to the optional press/spin cycle via the drain line  160  and drain valve  162 , sanitize the soiled wash water using the integrated fluid sanitizer module  180 , and deliver sanitized water to the optional storage tank  174  for use during for use during any one of the one or more cycles of a second wash session (e.g., a rinse cycle of the second wash session). As described above, hydrogen peroxide can be delivered by the chemical reservoir or tank  154  during one of the one or more wash cycles of the wash session. When sanitized water is delivered back into the housing  102  from the recirculation line  170 , a residual volume of o-zone gas remains in the sanitized water. Thus, the residual o-zone gas reacts with the hydrogen peroxide used during, for example, the rinse cycle  130  to produce hydroxyl radicals that can clean (e.g., whiten and brighten) the laundry. 
     The controller  108  is generally used to control the operation of the various elements of the washing system  100  and includes one or more processors and an associated memory device for storing instructions that are executable by the one or more processors. The controller  108  also includes a communication module that is communicatively coupled (e.g., by a wireless connection and/or a wired connection) to the various components of the washing system  100 , such as the fluid inlet  104 , the fluid outlet  106 , the drain valve  162 , the pump  172 , the integral fluid sanitizer module  180 , the optional storage tank  174 , the fresh water reservoir or tank  150 , the chemical reservoir or tank  154 , or any combination thereof. The controller  108  can also include a human-machine interface (“HMI”), such as a touchscreen interface, to permit a user to control the various components of the washing system  100 . For example, the HMI of the controller  108  can permit the user to select whether to operate the optional pre-wash cycle  110  or the optional press/spin cycle  140 , to select the volume of wash water that the drain valve  162  diverts to the recirculation line  170 , etc. 
     While the washing system  100  is shown as including all of the components described above, more or fewer components can be included in a washing system. For example, an alternative washing system (not shown) includes the housing  102 , the drain line  160 , and the recirculation line  170 . Thus, various washing systems can be formed using any portion of the basic components described herein. 
     Referring to  FIG.  3   , a tunnel washing system  200  that is similar to the washing system  100  includes a wash tunnel  202 , a press  240 , a fresh water reservoir  250 , a chemical reservoir  254 , a first tank  260 , a second tank  264 , a first recirculation line  270 , a second recirculation line  272 , a third recirculation line  273 , an optional fourth recirculation line  274 , and an optional fifth recirculation line  275 . The tunnel washing system  200  is generally used to efficiently clean large volumes of soiled laundry. 
     The wash tunnel  202  includes a loading hopper  204 , a helix that defines a plurality of modules  206 , a first seal  208   a , a second seal  208   b , and a third seal  208   c . The helix is disposed within the wash tunnel  202  and has a helix/cork-screw shape which defines the plurality of modules  206 . The first seal  208   a , the second seal  208   b , and the third seal  208   c  are positioned within the wash tunnel  202  such that the first seal  208   a  defines a pre-wash zone  210 , the first seal  208   a  and the second seal  208   b  define a main wash zone  220 , and the second seal  208   b  and the third seal  208   c  define a rinse zone  230 . As shown, the pre-wash zone  210  includes modules  1 ,  2 , and  3  of the plurality of modules  206 , the main wash zone  220  includes modules  4 ,  5 ,  6 ,  7 ,  8 , and  9  of the plurality of modules  206 , and the rinse zone  230  includes modules  10 ,  11 ,  12 ,  13 , and  14  of the plurality of modules  206 . 
     Each of the plurality of modules  206  includes perforations (not shown) to permit fluid to flow between adjacent modules within the pre-wash zone  210 , the main wash zone  220 , and the rinse zone  230  (e.g., between module  1  and module  2 ). The seals  208   a ,  208   b , and  208   c  inhibit fluid from freely flowing between adjacent modules of the plurality of modules  206  (e.g., between module  9  and module  10 ). More specifically, the first seal  208   a  inhibits fluid flow between the pre-wash zone  210  and the main wash zone  220 , the second seal  208   b  inhibits fluid flow between the main wash zone  220  and the rinse zone  230 , and the third seal  208   c  inhibits fluid flow between the rinse zone  230  and the press  240 . As a result, fluid flows through the plurality of modules  206  along arrow A in the main wash zone  220 , and fluid flows through the plurality of modules  206  along arrow B in the rinse zone  230 . 
     To operate the tunnel washing system  200 , soiled laundry is placed into the wash tunnel  202  through the loading hopper  204  and falls into module  1  of the plurality of modules  206  in the pre-wash zone  210 . The helix oscillates back and forth within the wash tunnel  202  along a central axis to agitate the soiled laundry within the first module for a predetermined period (e.g., between about one minute and about two minutes). After the predetermined period, the helix rotates a full revolution about its central axis, and the soiled laundry is exchanged from module  1  to module  2  of the plurality of modules  206  through a generally central throughhole of the helix. In this manner, the soiled laundry moves through the plurality of modules  206  of the wash tunnel  202  towards the press  240 . 
     While the plurality of modules  206  of the wash tunnel  202  is shown as having fourteen modules, the plurality of modules  206  can have any number of modules based on the geometry of the helix (e.g., three modules, ten modules, twenty modules, thirty modules, etc.). While not shown, the wash tunnel  202  can also include a finish zone positioned between the third seal  208   c  and the press  240 . The finish zone is generally used to administer a final treatment of water/chemicals to the laundry prior to entering the press  240 , and can comprise two modules of the plurality of modules  206 . 
     The fresh water reservoir  250  is the same as, or similar to, the fresh water reservoir or tank  150  of the washing system  100  described above and includes a fresh water pump  251 , a first fresh water valve  252   a , a second fresh water valve  252   b , a third fresh water valve  252   c , a fourth fresh water valve  252   d . The fresh water pump  251  pumps fresh water from the fresh water reservoir  250  towards the fresh water valves  252   a ,  252   b ,  252   c , and  252   d . The chemical reservoir  254  is the same as, or similar to, the chemical reservoir or tank  154  of the washing system  100  described above and includes a first chemical valve  256   a , a second chemical valve  256   b , and a third chemical valve  256   c . The chemical reservoir  254  can include a pump (not shown) that is the same as, or similar to, the fresh water pump  251 . 
     The first tank  260  includes a first tank feed line  262  that is coupled to the first fresh water valve  252   a  and a first overflow line  263 . The first tank feed line  262  delivers fresh water from the fresh water reservoir  250  to the first tank  260  for storage therein. The fresh water pump  251  and the first fresh water valve  252   a  control the volume of fresh water that flows into the first tank  260  through the first tank feed line  262 . Similarly, the second tank  264 , which is the same as, or similar to, the first tank  260 , includes a second tank feed line  266  that is the same as, or similar to, the first tank feed line  262  and is coupled to the second fresh water valve  252   b . The second tank  264  also includes a second overflow line  267 . The first tank feed line  262  and the second tank feed line  266  can be a metal pipe, a PVC pipe, a hose, or the like, or any combination thereof. 
     The pre-wash zone  210  of the wash tunnel  202  includes a pre-wash feed line  212  and a pre-wash chemical feed line  214 . The pre-wash feed line  212  is coupled to the first tank  260  and includes a pump  213 . The pump  213  pumps fluid stored in the first tank  260  (e.g., fresh water delivered by the first tank feed line  262  described above) through the pre-wash feed line  212  and into the pre-wash zone  210  (e.g., into the loading hopper  204  and/or module  1 ). The pre-wash chemical feed line  214  is coupled to the first chemical valve  256   a  of the chemical reservoir  254  and delivers chemicals to the pre-wash zone  210  (e.g., into the loading hopper  204  and/or module  1 ). The chemicals delivered by the pre-wash chemical feed line  214  and the fluid delivered by the pre-wash feed line  212  mix to form pre-wash water that is then used in the pre-wash zone  210 . 
     The main wash zone  220  of the wash tunnel  202  includes a main wash feed line  222  and a wash chemical feed line  224 . The main wash feed line  222  is coupled to the second tank  264  and includes a pump  223 . The pump  223  pumps fluid stored in the second tank  264  (e.g., fresh water delivered by the second tank feed line  266  described above) through the main wash feed line  222  and into the main wash zone  220  (e.g., into module  9 ). The wash chemical feed line  224  is coupled to the second chemical valve  256   b  of the chemical reservoir  254  and delivers chemicals into the pre-wash zone  210  (e.g., into module  9 ). The chemicals delivered by the wash chemical feed line  224  and the fluid delivered by the main wash feed line  222  mix to form wash water that is then used in the main wash zone  220 . 
     The rinse zone  230  of the wash tunnel  202  includes a fresh water feed line  232  and a rinse chemical feed line  234 . The fresh water feed line  232  is coupled to the third fresh water valve  252   c  of the fresh water reservoir  250  and delivers fresh water from the fresh water reservoir  250  to the rinse zone  230  (e.g., into module  14 ). The rinse chemical feed line  234  is coupled to the third chemical valve  256   c  of the chemical reservoir  254  and delivers chemicals into the rinse zone  230  (e.g., into module  14 ). The chemicals delivered by the rinse chemical feed line  234  and the fresh water delivered by the fresh water feed line  232  mix to form rinse water that is then used in the rinse zone  230 . 
     As shown, the press  240  is positioned directly adjacent to the rinse zone  230  and includes a press water feed line  242  and a press water tank  244 . Laundry exits the rinse zone  230  of the wash tunnel  202  and enters the press  240 . The press  240  is generally used to remove excess rinse water from the laundry prior to transporting the laundry to a dryer. The press  240  removes excess water by compressing or squeezing the laundry to expel excess water (“soiled press water”) using hydraulic mechanisms or the like. The press water feed line  242  is coupled to the fourth fresh water valve  252   d  of the fresh water reservoir  250  and delivers fresh water from the fresh water reservoir  250  to the press  240 . The press water tank  244  receives and stores the soiled press water and includes a press water diversion valve  246 . 
     The first recirculation line  270  is coupled to the press water diversion valve  246  and includes a pump  270   a  and an integrated fluid sanitizer module  280 . The first recirculation line  270  receives a portion of the soiled press water from the press water tank  244  via the press water diversion valve  246 . The integrated fluid sanitizer module  280  is the same as or similar to the integrated fluid sanitizer module  180  of the washing system  100  described above and is used to at least partially sanitize the portion of the soiled press water received by the first recirculation line  270 . The pump  270   a  pumps the portion of the soiled press water through the first recirculation line  270  and the integrated fluid sanitizer module  280  to the rinse zone  230  (e.g., as shown, into module  14 ). The first recirculation line  270  can be a metal pipe, a PVC pipe, a hose, or the like, or any combination thereof. In some implementations, the first recirculation line  270  includes a storage tank (not shown) that is the same as or similar to the optional storage tank  174  of the washing system  100 . 
     The second recirculation line  272  is similar to the first recirculation line  270  in that it is coupled to the press water diversion valve  246  and includes a pump  272   a . The second recirculation line  272  receives a second portion of the soiled press water from the press water tank  244  via the press water diversion valve  246 . The second recirculation line  272  differs from the first recirculation line in that it is coupled to the first tank  260 , and the pump  272   a  pumps the second portion of the soiled press through the second recirculation line  272  to the first tank  260 . The second portion of the soiled press water mixes with the fresh water delivered to the first tank  260  via the first tank feed line  262 . As described above, the pre-wash feed line  212  delivers fluid from the first tank  260  to the pre-wash zone  210 , meaning that at least some of the second portion of the soiled press water received by the first tank  260  is delivered to the pre-wash zone  210  via the pre-wash feed line  212 . 
     Like the first recirculation line, the second recirculation line  272  can be a metal pipe, a PVC pipe, a hose, or the like, or any combination thereof. While not shown, in some implementations, the second recirculation line can include a second integrated fluid sanitizer module that is the same as or similar to the integrated fluid sanitizer module  280  of the first recirculation line and the integrated fluid sanitizer module  180  of the washing system  100 . In other implementations, the press tank can include an integrated fluid sanitizer module that is the same as or similar to the integrated fluid sanitizer module  280  that sanitizes the press water prior to being delivered to the first recirculation line  270  and/or second recirculation line  272 . 
     The press water diversion valve  246  controls amount of soiled press water that flows into either the first recirculation line  270  or the second recirculation line  272 . For example, desirably, the press water diversion valve  246  diverts about thirty percent to about fifty percent of the soiled press water from the press water tank  244  to the first recirculation line  270  and about seventy percent to about thirty percent of the soiled press water from the press water tank  244  to the second recirculation line  272 . Diverting about thirty percent to about fifty percent of the soiled press water to the first recirculation line  270  helps prevent the first tank  260  from overflowing due to the second recirculation line  272 . 
     As described above, the rinse zone  230  uses rinse water which comprises fresh water received via the fresh water feed line  232 , chemicals received via the rinse chemical feed line  234 , and/or sanitized press water received via the first recirculation line  270 . As shown in  FIG.  3    and described above, the rinse water generally flows between module  14  and module  10  along arrow B. The rinse zone  230  includes a rinse water drain  235  (often referred to as a “weir box”) to control the rinse water level in the rinse zone  230  and to drain soiled rinse water that has been contaminated by the laundry (e.g., rinse water that has flowed from module  14  to module  10 ). The rinse water drain  235  is coupled to a rinse drain line  236  that receives the soiled rinse water. The rinse drain line  236  includes a lint screen  237  and a rinse water diversion valve  238 . As shown, the lint screen  237  is integral with the rinse drain line  236  and is positioned upstream of the rinse water diversion valve  238 . The lint screen  237  removes lint that has accumulated in the soiled rinse water from the laundry. The rinse drain line  236  continues past the rinse water diversion valve  238  and is coupled to a main drain  290  that is the same as or similar to the main drain  164  of the washing system  100  (e.g., a sewage line). 
     The third recirculation line  273  is coupled to the rinse water diversion valve  238  and includes a pump  273   a . The third recirculation line  273  receives a portion of the soiled rinse water from the rinse drain line  236  via the rinse water diversion valve  238 . The third recirculation line  273  is also coupled to the second tank  264 , and the pump  273   a  pumps the portion of the soiled rinse water through the third recirculation line  273  to the second tank  264 . The portion of the soiled rinse water then mixes with the fresh water delivered to the second tank  264  via the second tank feed line  266 . As described above, the main wash feed line  222  delivers fluid from the second tank  264  to the main wash zone  220 . As a result, at least some of the portion of the soiled rinse water received by the second tank  264  is delivered to the main wash zone  220  via the main wash feed line  222 . 
     The third recirculation line  273  is the same as or similar to the first and second recirculation lines  270 ,  272  in that the third recirculation line  273  can be a metal pipe, a PVC pipe, a hose, or the like, or any combination thereof, and can include an integrated fluid sanitizer module (not shown) that is the same as or similar to the integrated fluid sanitizer module  280 . Alternatively, the rinse drain line  236  can include an integrated fluid sanitizer module that is the same as or similar to the integrated fluid sanitizer module  280  and sanitizes the soiled rinse water upstream of the rinse water diversion valve  238 . 
     In some implementations, the tunnel washing system  200  includes the optional fourth recirculation line  274 , which is coupled to the rinse water diversion valve  238  and includes a pump  274   a . The optional fourth recirculation line  274  is similar to the third recirculation line  273  in that it is coupled to the rinse water diversion valve  238  and receives a second portion of the soiled rinse water from the rinse drain line  236 . More specifically, in such implementations, the rinse water diversion valve  238  is a four-way valve that is used to control the respective volumes of the portion of the soiled rinse water received by the third recirculation line  273 , the second portion of the soiled rinse water received by the optional fourth recirculation line  274 , and a third portion of the soiled rinse water received by the main drain  290 . As shown, the optional fourth recirculation line  274  is connected to first recirculation line  270  so that second portion of the soiled rinse water flows through the integrated fluid sanitizer module  280  and is sanitized. As described above, the first recirculation line  270  delivers fluid from the integrated fluid sanitizer module  280 , thus, in such implementations, the first recirculation line  270  delivers sanitized rinse water to the rinse zone  230  (e.g., into module  14 ). Alternatively, the optional fourth recirculation line  274  can include a fourth integrated fluid sanitizer module (not shown) that is the same as or similar to the integrated fluid sanitizer module  280 , and the fourth recirculation line directly delivers sanitized rinse water to the rinse zone  230 . 
     As described above, the main wash zone  220  uses wash water which comprises fluid from the first tank  260  received via the main wash feed line  222  and/or chemicals received via the wash chemical feed line  224 . As shown in  FIG.  3    and described above, the wash water generally flows between module  9  and module  4  along arrow A. The main wash zone  220  includes a wash water drain  225  (often referred to as a “weir box”) to control the wash water level in the main wash zone  220  and to drain soiled wash water (e.g., wash water that has flowed from module  9  to module  4  and has become contaminated by the soiled laundry). The wash water drain  225  is coupled to a wash water drain line  226  that receives the soiled wash water and has a wash water diversion valve  228 . The wash water drain line  226  continues downstream of the wash water diversion valve  228  and is coupled to the main drain  290 . As shown, the overflow line  263  of the first tank  260  and the overflow line  267  of the second tank  264  are coupled to the wash water drain line  226  downstream of the wash water diversion valve  228 , permitting overflow from the first tank  260  and/or second tank  264  to spill into the main drain  290  and exit the system. 
     In some implementations, the tunnel washing system  200  includes an optional fifth recirculation line  275  that is coupled to the wash water diversion valve  228  and includes a pump  275   a . The optional fifth recirculation line  275  is similar to the optional fourth recirculation line  274  in that it receives a second portion of the soiled wash water from the wash water drain line  226  via the wash water diversion valve  228 . As shown, the optional fifth recirculation line  275  is coupled to the first tank  260 , and the pump  275   a  pumps the second portion of the soiled wash water through the fifth recirculation line  275  and into the first tank  260 . As described above, the pre-wash feed line  212  delivers fluid from the first tank  260  to the pre-wash zone  210 , thus, in such implementations, the pre-wash feed line  212  delivers at least a some of the second portion of soiled wash water stored in the first tank  260  to the pre-wash zone  210 . 
     In some implementations, the optional fifth recirculation line  275  can include an integrated fluid sanitizer that is the same as or similar to the integrated fluid sanitizer module  280  of the first recirculation line  270  to sanitize the soiled wash water prior delivering it to the first tank  260 . Further the fifth recirculation line  275  can be coupled to the pre-wash zone  210  (e.g., via the loading hopper  204 ) to directly deliver soiled wash water to the pre-wash zone  210 . 
     Referring generally to  FIGS.  4 A and  4 B , the pH of the pre-wash water, the wash water, and the rinse water of a washing system can be controlled to effectively clean soiled laundry. As shown, it is desirable that the pH of the pre-wash zone water is between about 9 and about 10.5, the pH of the main wash zone water is between about 10.5 and about 7, and the pH of the rinse zone water and press water is between about 5 and about 6. In other words, the pre-wash zone and a first half of the main wash zone comprise a high alkalinity zone (i.e., high pH) and a second half of the main wash zone, the rinse zone, and the press comprise a low alkalinity zone (i.e., low pH). 
       FIG.  4 A  shows the pH of pre-wash zone water, main wash zone water, rinse zone water, and press water of a first washing system that is similar to the tunnel washing system  200  described above. The first washing system differs from the tunnel washing system  200  in that it does not include a first recirculation line, a fourth recirculation line, or a fifth recirculation line. As described above, the pre-wash zone receives fluid from the first tank, which includes fresh water and soiled press water, meaning that the pH of the fluid delivered from the first tank to the pre-wash zone is about 6. To raise the pH of the pre-wash zone water to be between about 10.5 and about 11, chemicals must be added to the pre-wash zone via a chemical feed line that is the same as or similar to the pre-wash chemical feed line  214  described above. This required change in pH in the pre-wash zone is illustrated by ΔpH 1  in  FIG.  4 A . Similarly, laundry enters into the rinse zone from the high alkalinity zone (i.e., with a high pH) saturated with wash water, and the rinse zone receives rinse water a fresh water feed line that is the same as or similar to the fresh water feed line  232  described above. Thus, chemicals (e.g., sours, parasitic acid, hydrogen peroxide, or any other suitable chemical with a low pH) must be delivered to the rinse zone via a chemical feed line that is the same as or similar to the rinse chemical feed line  234  to lower the pH of the rinse zone water to be between about 5 and about 6. The required change in pH in the rinse zone is illustrated by ΔpH 2  in  FIG.  4 A . 
       FIG.  4 B  shows the pH the pre-wash zone water, main wash zone water, rinse zone water, and press water of a second washing system that is similar to the first washing system and the tunnel washing system  200  described above. The first washing system differs from the first washing system in that it includes a first recirculation line that is the same as or similar to the first recirculation line  270  of the tunnel washing system  200  and a fifth recirculation line that is the same as or similar to the optional fifth recirculation line  275  of the tunnel washing system  200 . The fifth recirculation line delivers soiled wash water, which has a pH of between about 10.5 and about 11, to the first tank. As a result, the pH of the fluid in the first tank is raised to about 9.5 prior to being delivered to the pre-wash zone, meaning that the required change in pH at the beginning of the pre-wash zone denoted by ΔpH 3  is substantially less than ΔpH 1  in  FIG.  4 A  for the first washing system. Similarly, the first recirculation line delivers sanitized press water to the rinse zone having a pH of between about 5 and about 6. Thus, the required change in pH in the rinse zone, which is denoted by ΔpH 4 , is substantially less than ΔpH 3  in  FIG.  4 A  for the first washing system. In other words, fewer chemicals are required to obtain the desired pH level in the pre-wash zone and in the rinse zone, reducing the costs to operate the second washing system as compared to the first washing system. 
     While the integrated fluid sanitizer modules  180 ,  280  have been described herein as being used in a recirculation line (e.g., recirculation line  170 ), the integrated fluid sanitizer modules can be used in other portions of the wash systems  100 ,  200 . For example, the wash water drain line  226  can include an integrated fluid sanitizer module that is the same as, or similar to, the integrated fluid sanitizer  180 . In such implementations, soiled water wash is at least partially sanitized by the integrated fluid sanitizer module prior to being discharged into the main drain  290  (e.g., a sewage line). 
     EXAMPLES 
     In one example, a washing system that is similar to the washing systems  100  and  200  described above in that it includes an integrated fluid sanitizer module (e.g., the integrated fluid sanitizer module  180  shown in  FIG.  2   ). The water in this washing system was tested to demonstrate the reduction in bacteria in the water after passing through the integrated fluid sanitizer module. Table 1 shows the test results in colony-forming units per milliliter (“CFU”): 
     
       
         
           
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                 Pre-Aerobic Plate  
                 Pre-Aerobic Plate  
                   
               
               
                   
                 Count of Water  
                 Count of Water  
                   
               
               
                   
                 Pre-treatment 
                 Post-treatment 
                 Method 
               
               
                   
               
             
            
               
                 Test #1 
                 37 CFU/mL 
                 3 CFU/mL 
                 SM 9215B 20 th  Ed. 
               
               
                 Test #2 
                 73 CFU/mL 
                 8 CFU/mL 
                 SM 9215B 20 th  Ed. 
               
               
                   
               
            
           
         
       
     
     As indicated by the test results in Table 1, the integrated fluid sanitizer caused a 99.92% reduction in bacteria in Test #1 and a 99.89% reduction in bacteria in Test #2 (using a logarithmic scale reduction). For water to be considered potable (i.e., drinkable), the Safe Drinking Water Act currently requires the Maximum Contaminant Level (“MCL”) of microorganisms to be below 200 MCL. 
     To further demonstrate that the integrated fluid sanitizer module continuously disinfects water as it recirculates through the washing system multiple times, a second test was completed to measure the contaminates before and after a first recirculation loop, and before and after a second recirculation loop. Table 2 below summarizes the results: 
     
       
         
           
               
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                   
                 Pre-Aerobic Plate  
                 Pre-Aerobic Plate  
                   
               
               
                   
                 Count of Water at  
                 Count of Water  
                   
               
               
                   
                 Beginning of Loop 
                 at End of Loop 
                 Method 
               
               
                   
               
             
            
               
                 Loop #1 
                  7 CFU/mL 
                  5 CFU/mL 
                 SM 9215B 20 th  Ed. 
               
               
                 Loop #2 
                 36 CFU/mL 
                 21 CFU/mL 
                 SM 9215B 20 th  Ed. 
               
               
                   
               
            
           
         
       
     
     As indicated by the test results in Table 2, the integrated fluid sanitizer module continued to reduce bacteria in the water during multiple recirculation cycles in the washing system. Thus, the integrated fluid sanitizer module can be used to at least partially sanitize the same recirculation water multiple times. 
     While the disclosure is susceptible to various modifications and alternative forms, specific embodiments and methods thereof have been shown by way of example in the drawings and are described in detail herein. It should be understood, however, that it is not intended to limit the disclosure to the particular forms or methods disclosed, but, to the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the disclosure.