Abstract:
An electrolysis device is disclosed for producing alkaline water from water including an electrolysis vessel, a positive electrode, a negative electrode, a bipolar membrane element, and at least one cation exchangeable membrane within the electrolysis vessel. The bipolar membrane element has a cation exchangeable side and an anion exchangeable side, the cation exchangeable side being closer to the negative electrode than the anion exchangeable side. The at least one cation exchangeable membrane is arranged between the anion exchangeable side of the bipolar membrane element and the positive electrode, so as to define an alkali chamber between the bipolar membrane element and the cation exchangeable membrane. An ionic exchange resin is associated with the vessel, whereby flow of the water though the vessel and the ionic exchange resin produces alkaline water in the alkali chamber. Various options and modifications are possible. A related washing machine such as a dishwasher is also disclosed.

Description:
FIELD OF THE INVENTION 
       [0001]    The subject matter disclosed herein relates generally electrolysis devices useful for cleaning and to related washing machines that can operate without use of detergent. 
       BACKGROUND OF THE INVENTION 
       [0002]    Most clothes washers and dishwashers use detergents to clean the desired objects (clothing or cookware). Various formulations of detergents have been introduced that provide excellent cleaning in either type of machine. For example, clothes washers often use a surfactant such as a linear alkylbenzenesulfonates, usually along with water softeners, bleaches, enzymes, etc. Dishwashers also use surfactants, water softeners, bleaches, enzymes, and other ingredients. 
         [0003]    Detergents have become substantially more environmentally sensitive over the years in terms of wastewater processing concerns of the various ingredients. However, use of detergents generally requires use of rinse cycles, which in turn requires that additional water and energy be used by the machine. Further, additional wastewater is generated during such a rinse cycle, requiring additional treatment in a septic or sewage system. 
         [0004]    In order to avoid or reduce use of detergents, detergentless ionic washing has been proposed in clothing and dishwashers. For example, a number of such ionic washers are disclosed in US 2009/0159448, owned by Applicants&#39; Assignee, and incorporated by reference herein. In that patent application, alkaline water is produced for detergentless washing in various embodiments of electrolysis devices. However, due to the low conductivity of typical tap water, energy consumption of such ionic devices may be high. Also, undesirable scaling may occur in some such systems in some conditions. Accordingly, an improved detergentless ionic washing system would be welcome. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0005]    Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention. 
         [0006]    According to certain aspects of the disclosure, an electrolysis device is disclosed for producing alkaline water from water including an electrolysis vessel, a positive electrode, a negative electrode, a bipolar membrane element, and at least one cation exchangeable membrane within the electrolysis vessel. The bipolar membrane element has a cation exchangeable side and an anion exchangeable side, the cation exchangeable side being closer to the negative electrode than the anion exchangeable side. The at least one cation exchangeable membrane is arranged between the anion exchangeable side of the bipolar membrane element and the positive electrode, so as to define an alkalic chamber between the bipolar membrane element and the cation exchangeable membrane. An ionic exchange resin is associated with the vessel, whereby flow of the water though the vessel and the ionic exchange resin produces alkaline water in the alkalic chamber. Various options and modifications are possible. 
         [0007]    According to certain other aspects of the disclosure, a detergentless washing machine includes a washing compartment for washing objects and an electrolysis vessel for supplying alkaline water to the washing compartment. The electrolysis vessel includes a positive electrode, a negative electrode, a bipolar membrane element, and at least one cation exchangeable membrane within the electrolysis vessel. The bipolar membrane element has a cation exchangeable side and an anion exchangeable side, the cation exchangeable side being closer to the negative electrode than the anion exchangeable side. The at least one cation exchangeable membrane is arranged between the anion exchangeable side of the bipolar membrane element and the positive electrode, so as to define an alkalic chamber between the bipolar membrane element and the cation exchangeable membrane. An ionic exchange resin is associated with the vessel, whereby flow of the water though the vessel and the ionic exchange resin produces the alkaline water in the alkalic chamber to be provided to the washing compartment for washing the objects. Again, various options and modifications are possible. 
         [0008]    These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which: 
           [0010]      FIG. 1  provides a schematic view of a washer having an electrolysis device according to certain aspects of the disclosure; 
           [0011]      FIG. 2  provides a schematic view of one possible electrolysis device useful in the washer of  FIG. 1 ; 
           [0012]      FIG. 3  provides a schematic view of another possible electrolysis device useful in the washer of  FIG. 1 ; 
           [0013]      FIG. 4  provides a schematic view of another possible electrolysis device useful in the washer of  FIG. 1 ; and 
           [0014]      FIG. 5  provides a schematic view of another possible electrolysis device useful in the washer of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. 
         [0016]      FIG. 1  illustrates an exemplary washing machine  10 . The exemplary washing machine  10  may include for example a cabinet  12 , a hinged door  14 , a washing compartment  16  in which washing of objects occurs, a water supply  18 , and a water outlet  20 . If desired, water supply  18  may include separate hot and cold water supplies (not shown). Water supply  18  and outlet  20  are connected to washing compartment  60  in conventional ways. Washing compartment  16  could be fixed (as in a dishwasher or the like) or could include a movable/rotatable drum within a larger container (as in a clothes washer or the like). Washing compartment  16  could include various conventional items within it such as sprayers, racks, tumbling structures, vents and drains, etc., as desired. 
         [0017]    Washing machine  10  may include a user interface  22  including one or more input devices such as buttons, and one or more output devices such as displays, LED&#39;s, etc. A conventional controller  24 , for example including a memory and processor, within washing machine  10  may receive and send signals from user interface  22  and other components of the device (not shown for clarity as unnecessary to fully disclose and explain the present inventive concepts), such as pumps, motors, valves, containers, sensors, power sources, rectifiers, etc., as are known to perform desired washing activities and cycles. 
         [0018]    It should therefore be understood that washing machine  10  could comprise a clothes washer, a dish washer, a medical device sterilizer, or any other water-based machine for washing items. Therefore, conventional components of such devices as mentioned above could be adapted to employ the detergentless cleaning devices disclosed herein. 
         [0019]      FIG. 1  further schematically shows an electrolysis device  28  located within washing machine  10  and including an electrolysis cell  30 . A container  32  holds the alkaline product of electrolysis device  30 . Conduits  34  and  36  connect container  32  to electrolysis device  30 , and conduit  38  connects container  32  to washing compartment  16 . A container  40  holds the acidic product of electrolysis device  30 . Conduits  42  and  44  connect container  40  to electrolysis device  30 , and conduit  46  connects container  40  to washing compartment  16 . Electrolysis device  30  may receive water from water supply  18  as well via conduit  48 . 
         [0020]    As shown in  FIG. 2 , a cell unit  50  includes a positive electrode  52  and a negative electrode  54 . The electrodes may be highly porous metals, such as titanium mesh for example. The cell unit includes a vessel  56  and a number of cells  58 ,  60 ,  62 , and  64 . The cells are divided by ion exchange membranes  66 , 68 , and  70 . Membrane  66  is an anion exchange membrane, membrane  70  is a cation exchange membrane, and membrane  68  is a bipolar exchange membrane. Membrane  68  has an anion exchange side  72  and a cation exchange side  74 . 
         [0021]    Inlets  76 , 78 , 80  and  82  and outlets  84 , 86 , 88 , and  90  are provided for the cells  58 - 64 , respectively. Each cell has within it a mixture of both cation and anion exchange resins  92  which may be any of a number of commercially available resins. For example, the resins may be cross-linked divinylbenzene, if desired. The cation exchange resin may have as a functional group a sulfonic group (—SO3H or −SO3Na), and the anion exchange resin may have as a the functional group a quaternary amine group. 
         [0022]    An acid container  94  and an alkaline container  96  are provided as well. Acid container  94  has a first outlet  98  connected to cell inlets  78  and  82 , and a second outlet  100  that is connected to a desired end use location, such as the interior of a washer  10 . An inlet  102  is connected to cell outlets  86  and  90 . Acidic liquid can thus cycle through cells  60  and  64  (acidic chambers) and container  94  via a pump (not shown). Alkaline container  96  has a first outlet  104  is similarly connected to cell inlets  76  and  80  and a second outlet  106  connected to a desired end use location. Inlet  108  is connected to cell outlets  84  and  88 . Alkaline liquid can thus cycle through cells  58  and  62  (alkalic chambers) in a similar fashion. 
         [0023]    Cells  58 - 64  should be large enough to generate sufficient alkaline water for cleaning the desired objects in a reasonable amount of time. For example, if used in a dishwasher, typical wash cycles vary from 30-75 minutes or so, depending on the device and the chosen cycle. Therefore, the size, flow rate, current, etc. can be chosen to obtain an amount of alkaline water needed for a given cycle. To generate 1.2 gallons of alkaline water of a pH of over 11, for example, might require cells with membranes as large as 10×20 cm, that run for an amount of time such as 20-25 minutes or so. Such alkaline water can be used in a dishwasher instead of detergent to clean cookware during a typical cleaning cycle. The acidic water generated can be used during rinsing to sanitize or sterilize as well. 
         [0024]    The presence of the ion exchange resins within the cells allows the cells to operate while reducing CaCO 3  scaling and other such deposits on the ion exchange membranes while still allowing the chemical and electrical reactions to occur. It is believed that the regeneration of H and OH ions caused by the ion exchange resins beneficially prevents such scaling deposits. Further, by placing the ion exchange resins in the cells, the resins do no wear out, or will do so much more slowly so that they need not be changed out during the life of the product. 
         [0025]      FIG. 3  shows a variation of cell unit  50  of  FIG. 2 . In  FIG. 3 , like parts receive like reference numerals, so all need not be mentioned herein. Cell unit  150  of  FIG. 3  differs from that of  FIG. 2  in that cells  158 - 164  do not include mixtures of ion exchange resins. Instead, anion exchange resins  191  are located in cells  158  and  162 , and cation exchange resins  193  are located in cells  160  and  164 . Resins may be of the types described above. Splitting the resins on a per cell basis may provide better performance in certain situation in terms of higher acid and alkaline generation at a given set of parameters. 
         [0026]      FIG. 4  shows another modified version in which mixed resins may be employed. However, cell unit  250  of  FIG. 4  includes three separate cells on each side of bipolar membrane  268  and formed by additional exchange membranes. As shown, cells  258  and  262  are connected to alkaline container  296 , as before. Cells  260  and  264  are connected to acidic container  294  in similar fashion. Membranes  265  and  270  are cation exchange membranes and membranes  266  and  271  are anion exchange membranes. Cells  259  and  263  are connected to a water cycle. Ion exchange resins  292  are mixed as illustrated, but could be separated out according to anion and cation as above, if desired. Therefore, cell  250  provides a further separated system in which feed water can be provided as needed via a separate inlet. The feed water need not be circulated as shown, but may simply be provided to the washing device or drained after cycling though cell  20 . Cell  250  may thus provide another arrangement for created alkaline water and acidic water for cleaning, while providing a ready source of water to the device as substances are used during cleaning. 
         [0027]    Finally,  FIG. 5  shows an alternate device in which cell  350  is a modified version of cells  50  and  150  above. In cell  350 , however, separate containers  395  and  397  are provided for the anion exchange resin  391  and the cation exchange resin  393 , respectively. Placing the exchange resins exterior to cell  350  does provide a number of the regenerative and anti-scaling benefits discussed above. However, in case performance degrades over time due to the resins and/or other portions of the cell becoming fouled or scaled, the resins can be replaced in containers  395  and  397  without having to replace the entire cell vessel  356 . In some applications, this may be sufficient to provide the benefits mentioned above while still allowing for maintenance. Alternatively. The resins can be periodically changed on a regular schedule regardless of any fouling, degradation, etc., if desired to ensure peak performance of cell  350 . 
         [0028]    Accordingly, using the various electrolytic devices above and variations as disclosed, a detergentless wash can be achieved using alkalic and/or acidic water. In a dishwasher, sufficient alkalic water can be generated in a typical cycle amount of time, using minimal electric power as compared to the entire power demand of the machine, to suitably clean cookware using approximately 1.2 gallons of alkalic water at approximately 11 pH or more. Thus, detergent need not be employed, providing cost and environmental benefits. It should be understood that the electrolytic device herein may be used with various applications, including clothes and dish washing devices. However, other washing devices and other devices requiring alkaline and/or acidic water may be practiced using the present teachings. 
         [0029]    This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.