Abstract:
Systems and methods that facilitate aqueous ozone disinfection on a distributed basis that is sufficient to be effective at dramatically reducing bacteria on materials washed with ozonated water. The system provided herein facilitates the distribution of ozonated water to multiple sinks while keeping the additional hardware and associated costs at each sink at a minimum.

Description:
CROSS-REFERENCE TO RELATED APPLICAITONS 
       [0001]    This application claims the benefit of U.S. Provisional application No. 61/618,552, filed Mar. 30, 2012, which application is incorporated by reference. 
     
    
     FIELD 
       [0002]    The embodiments described herein relate generally to ozone disinfection and, more particularly, to systems and methods that facilitate aqueous ozone disinfection on a distributed basis that is sufficient to be effective at dramatically reducing bacteria on materials washed with ozonated water. 
       BACKGROUND INFORMATION 
       [0003]    The current accepted practice in food preparation typically results in the bacteria that arrived on the food item being spread to the prepared portions of the food item or to other items. The bacteria can lead to food spoilage and other complications resulting in increased costs. 
         [0004]    In order to combat the spread of bacteria, most establishments rinse the food items with water upon arrival and also rinse the food preparation surfaces and tools with water throughout the day. Water alone does not eliminate the bacteria. However, ozone in water has been demonstrated to be effective at dramatically reducing bacteria on materials washed with that ozonated water. 
         [0005]    In a food preparation installation, such as a restaurant or food packaging facility, an ozonated water system typically includes one or more sinks with a separate ozone generation system coupled to separate ones of the one or more sinks to supply ozonated water from the one or more sinks. In installations with several sinks, supplying ozonated water from each sink can be costly. In addition, in may not be physically feasible due to space and/or aesthetic reasons to provide an ozone generation system at each sink. 
         [0006]    Thus, it is desirable to provide a distributed ozone system that would facilitate aqueous ozone disinfection on a distributed basis that is sufficient to be effective at dramatically reducing bacteria on materials washed with ozonated water. 
       SUMMARY 
       [0007]    The embodiments described herein are directed to systems and methods that would facilitate aqueous ozone disinfection on a distributed basis that is sufficient to be effective at dramatically reducing bacteria on materials washed with ozonated water. The system provided herein facilitates the distribution of ozonated water to multiple sinks while keeping the additional hardware and associated costs at each sink at a minimum. In one embodiment, water supplied to a sink is mixed with ozone to produce ozonated water. The system includes a central ozone generation system coupled to a venturi system at each sink. The venturi system is used to mix the ozone with the water. The level of ozonation of the water at each sink may be monitored in real-time by an Oxidation-Reduction-Potential (ORP) meter to verify that the ozone level at each sink is sufficient to disinfect any pathogens present. A flow switch is positioned in line after the venturi system and coupled to the ozone generation system to prevent production of ozone until after the flow of water has commenced through the venturi system. 
         [0008]    Other systems, methods, features and advantages of the example embodiments will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0009]    The details of the example embodiments, including structure and operation, may be gleaned in part by study of the accompanying figures, in which like reference numerals refer to like parts. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, all illustrations are intended to convey concepts, where relative sizes, shapes and other detailed attributes may be illustrated schematically rather than literally or precisely. 
           [0010]      FIG. 1  is a schematic diagram of a distributed ozone disinfection system. 
           [0011]      FIG. 2  is a flow diagram of a distributed ozone disinfection system. 
           [0012]      FIG. 3  is a front view of a gas injector venturi device. 
           [0013]      FIG. 4  is a schematic of a control diagram for control of the distributed ozone disinfection system. 
           [0014]      FIG. 5  is a plan view of an ozone generator system. 
       
    
    
       [0015]    It should be noted that elements of similar structures or functions are generally represented by like reference numerals for illustrative purpose throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the preferred embodiments. 
       DETAILED DESCRIPTION 
       [0016]    Each of the additional features and teachings disclosed below can be utilized separately or in conjunction with other features and teachings to produce systems and methods to facilitate distributed aqueous ozone disinfection. Representative examples of the present invention, which utilize many of these additional features and teachings both separately and in combination, will now be described in further detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Therefore, combinations of features and steps disclosed in the following detail description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the present teachings. 
         [0017]    Moreover, the various features of the representative examples and the dependent claims may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings. In addition, it is expressly noted that all features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original disclosure, as well as for the purpose of restricting the claimed subject matter independent of the compositions of the features in the embodiments and/or the claims. It is also expressly noted that all value ranges or indications of groups of entities disclose every possible intermediate value or intermediate entity for the purpose of original disclosure, as well as for the purpose of restricting the claimed subject matter. 
         [0018]    The systems and methods provided herein address distribution of ozonated water to multiple sinks while keeping the additional hardware and associated costs at each sink at a minimum. The present systems and methods also allow the user to verify that the ozone level at each sink is sufficient to disinfect any pathogens present. The present system is particularly suited to use in restaurants and markets for ensuring the freshness and safety of food. 
         [0019]    To keep the added hardware at each sink at a minimum and the price per cost low, the ozone is generated at a central location in the facility and piped through tubes to a plurality of sinks. In a preferred embodiment, up to six sinks are preferably supplied with ozone from a single ozone generation system at a distance of up to 50 feet from the location where the ozone is generated. Just before the cold water pipe enters the sink the water pipe and the ozone tube are connected via a venturi device that mixes the ozone into the water. At the output of the venturi device is an optional oxidation reduction potential (ORP) sensor that measures the level of ozone in the water. If the ozone level is appropriate for pathogen reduction, the sensor will cause a light to go on near the sink so that a user can be sure that sufficient ozone is being generated. 
         [0020]    In order that ozone is generated only when it is needed, a thermal differential flow switch attached to the water pipe near the sink is used to determine when cold water is flowing into the sink. A wire connects this switch to the central ozone generating device. When the device detects water flowing into the sink, it signals the ozone generating device to begin generating ozone. Approximately half a gallon of water will flow into the sink before the ozone reaches the sink. This will vary depending on the flow rate of the water. 
         [0021]    To produce the-ozone gas the centralized device consists of a pump that pushes ambient air into the device, a dehumidifier to ensure that the dew point of the pumped in air is sufficiently low for the ozone generator to work effectively, and an ozone generator that uses the corona discharge method for producing ozone. A fan is included to ensure that the device does not overheat. 
         [0022]    A system  10 , as shown in  FIG. 1 , for disinfection of pathogen on food items and other materials and tools encountered during food preparation and packaging in restaurants and markets, and the like, is comprised of a plurality of N sinks  20 A,  20 B and  20 N coupled to a water supply line  30 . Each sink includes a basin  22 , a faucet, and an on-off valve  26 . The water supply line  30  branches off to each sink  20 A,  20 B and  20 N at supply branches  32 A,  32 B and  32 N. Each supply branch includes a venturi system  50  where the water is mixed with ozone from a central ozone generating system  40  to produce ozonated water. The venturi systems  50  are coupled to the central ozone generating system  40  via ozone supply tubing  42  which branches off at branches  42 A,  42 B and  42 N to supply ozone to each venturi system  50 . A flow switch  44  is positioned downstream of the venturi system  50  and coupled to the central ozone generating system  40  electrically along line  45  or wirelessly. Alternatively, a flow switch may instead be positioned upstream of the supply branches  32 A,  32 B and  32 N in the water supply line  30  to detect flow through any of the supply branches  32 A,  32 B and  32 N. An ORP sensor  62  of an ORP monitoring system  60  is also positioned downstream of the venturi system  50  and may be coupled to the central ozone generating system  40  electrically along line  63  or wirelessly. 
         [0023]    In another alternative, an ozone reservoir  41  may be positioned downstream of the central ozone generating system  40  in one or more of the supply branches  32 A,  32 B and  32 N prior to the venture system  50 . The ozone reservoir tends to speed up the process of ozonating the water. The reservoir  41  is desirable for sinks that are spaced at a significant distance from the ozone generator system  40 . A one way check valve  43  is positioned upstream of the reservoir  41  prior to the venture system  50  to prevent water from flowing into the gas line  42 A. The venturi system  50  is preferably a gas injector venturi device, such as a Mazzei® venturi-type, differential pressure injector. See, e.g., U.S. Pat. No. 5,863,128. As depicted in greater detail in  FIG. 3 , the gas injector venturi device  50  narrows as it transitions from an injector inlet  52  to an injection chamber  53  and then widens as the injector  50  transitions from the injection chamber  53  to an injector outlet  54 . Located at the injection chamber  53  is a gas injection port  56 . An ozone gas supply line  42  ( FIG. 1 ), which extends to each sink, is coupled to the injection port  56 . Pressurized water entering the inlet  52  of the injector  50  changes to a high velocity jet stream as it passes through the injection chamber  53  drawing the ozone gas in through the injection port  56  to be entrained or dissolved in the pressurized water. 
         [0024]    Referring to  FIGS. 1 and 4 , the ozonated water exits the venturi device  50  and continues through an ozonated water piping section  34 A,  34 B and  34 N at each sink. An Oxidation-Reduction Potential (ORP) monitor system  60  includes a sensor  62  positioned downstream of the venturi device  50 . The ORP sensor  62  includes a probe extending into the flow of ozonated water in the ozonated water piping section  34 A,  34 B and  34 N. An ORP meter  64  analyzes the data from the ORP sensor  62  to determine if the level of ozone in the water is at a level sufficient for pathogen reduction. If so, the ORP meter  64  will cause an ORP indicator light  66  to go on at or near the sink so as to indicate to the user that sufficient ozone is being generated. As depicted in  FIGS. 4 and 5 , the central ozone generating system  40  includes an ozone generation system  80  that includes an ozone generator  82  having an inlet and outlet. The ozone generator  82  is preferably a corona discharge type ozone generator. The ozone generator  82  is coupled at its inlet to an air pump  84  and a de-humidifier  86 . The central ozone generating system  40  includes a control board  70  coupled to the ozone generation system  80  and configured to control the operation of the generation system  80 . 
         [0025]    The control logic for the central ozone generating system  40  is depicted in  FIG. 4 . As depicted, AC power at 120 V, 60 Hz is supplied to the system  40  and a user controlled mechanical switch  73  for interruptng power to the system  40  is provided. Included in the switch  73  is a power indicator light  74 . An AC-to-DC power transformer  75  is coupled to the switch  73  and provides 24 V DC power to the ORP (oxidation reduction potential) meter  64 , an ORP indicator light  66 , and a transfer relay  71 . As depicted, when the flow switch  44  detects water flowing, it closes a DC circuit that in turn closes (activations) the transfer relay  71 , giving AC power to the ozone generation circuit  70  and the ozone generator  80 . The ozone control board/generation circuit  70  and ozone generation system  80  are coupled in series with the transfer relay  71  to generate ozone once the relay  71  is activated to power the ozone generation circuit  70 . An indicator light  72  connected to the relay  71  indicates whether ozone is being generated (green) or not (red) based on whether the transfer relay is open (red) or closed (green). 
         [0026]    In operation, pressurized water is supplied to the system so that water is flowing past the flow switch  44 . When the power switch  73  is turned on or closed, the flow switch  44  senses whether water is flowing through the venturi system  50  for ozone to be mixed with. If water flow is detected by the flow switch  44 , the flow switch activates the transfer relay  71 . As a result, the transfer relay  71  closes and powers the ozone generation circuit  70  which causes the ozone generator  82  to generate ozone. With the transfer relay  71  activated, the indicator light  72  is illuminated green. If the flow switch  44  does not detect water flow through the piping system, the flow switch  44  will not activate the transfer relay  71  and, thus, the ozone generation circuit  70  will not be powered to cause the ozone generator  82  to generate ozone. With the transfer relay  71  remaining open, the indicator light  72  is illuminated red. 
         [0027]    Alternatively, instead of a flow switch, a vacuum sensor is provided to sense a vacuum at the gas injection port  56  of the gas injector venturi device  50  as water flows through the gas injector venturi device  50 . 
         [0028]    The example embodiments provided herein, however, are merely intended as illustrative examples and not to be limiting in any way. Moreover, one skilled in the art will readily recognize that similar systems can be equally adapted with appropriate modification of parameters. 
         [0029]    In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention. For example, the reader is to understand that the specific ordering and combination of process actions shown in the process flow diagrams described herein is merely illustrative, unless otherwise stated, and the invention can be performed using different or additional process actions, or a different combination or ordering of process actions. As another example, each feature of one embodiment can be mixed and matched with other features shown in other embodiments. Features and processes known to those of ordinary skill may similarly be incorporated as desired. Additionally and obviously, features may be added or subtracted as desired. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents.