Abstract:
Disclosed herein are an electrochemical softening apparatus that is relatively convenient and inexpensive and a washing machine including the same. The softening apparatus regenerates a zeolite compound that has been used to perform ion exchange using hydrogen ions (H + ) generated using an electrochemical method such that the zeolite compound is repeatedly used. Hydrogen ions (H + ) generated during a re-softening process are used to remove contaminants due to microorganisms and a scale component. The softening apparatus includes a regeneration unit to generate regeneration water containing hydrogen ions (H + ) and a softening unit, including an Ion exchange material regenerated by the regeneration water, to convert raw water containing a hardness component into soft water containing hydrogen ions (H + ).

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of Korean Patent Application No. 10-2013-0117616, filed on Oct. 2, 2013, and Korean Patent Application No. 10-2014-0006673, filed on Jan. 20, 2014 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    Embodiments of the present disclosure relate to a washing machine including a softening apparatus that simultaneously performs softening and washing (sterilization, descaling, etc.) and a washing machine including the same. 
         [0004]    2. Description of the Related Art 
         [0005]    When detergent is used to remove non-polar contaminants from electric home appliances (a washer, a dishwasher, etc.) using water, cleaning performance may be deteriorated due to hardness of the water and the electric home appliances may be contaminated due to microorganisms propagating in the water and a scale component. 
         [0006]    In order to prevent cleaning performance from being deteriorated due to hardness of the water, a heater may be used to increase solubility of the detergent, a hardness component may be removed using an ion exchange method, or electrochemical capacitive deionization (CDI) using electrostatic attractive force of an ion component may be applied. However, these methods do not fundamentally remove a hardness component (Ca 2+  or Mg 2+ ) with the result that the hardness component may deposited on an object to be washed or a complicated system may be used to remove the hardness component. In this case, however, material costs may be increased and high energy may be needed. Ion exchange resin using an ion exchange method is relatively inexpensive and convenient. When the ion exchange resin is regenerated for repetitive use, however, a high-concentration sodium chloride solution (NaCl) is used. As a result, actual application to the system is limited due to user inconvenience and environmental regulations due to regenerated waste water. 
         [0007]    In order to prevent the cleaning system from being contaminated due to microorganisms, various methods, such as high-temperature sterilization, decolorant ion sterilization, and negative ion sterilization, may be used. However, these methods may require high energy and cause user inconvenience due to use of additional consumable chemicals. In addition, actual application to the system is limited due to environmental regulations. 
         [0008]    For contamination due to the scale component, there are insufficient solutions. 
       SUMMARY 
       [0009]    It is an aspect to provide an electrochemical softening apparatus that is relatively convenient and inexpensive and a washing machine including the same. 
         [0010]    It is an aspect to provide a softening apparatus that regenerates zeolite that has been used to perform ion exchange using hydrogen ions (H + ) generated using an electrochemical method such that the zeolite is repeatedly used and a washing machine including the same. 
         [0011]    It is an aspect to provide a softening apparatus designed such that hydrogen ions exchanged with a hardness component during a re-softening process are used to remove contaminants due to microorganisms and a scale component and a washing machine including the same. 
         [0012]    Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the disclosure. 
         [0013]    In accordance with one aspect, a softening apparatus includes a regeneration unit to generate regeneration water containing hydrogen ions (H + ) and a softening unit, including an Ion exchange material regenerated by the regeneration water, to convert raw water containing a hardness component into soft water containing hydrogen ions (H + ). 
         [0014]    The regeneration unit may electrolyze water to generate the hydrogen ions (H+). 
         [0015]    The water may include soft water. 
         [0016]    The regeneration unit may include a housing forming an external appearance and an electrode provided in the housing. 
         [0017]    The Ion exchange material may be coupled to one side of the electrode via a binder such that the regeneration unit and the softening unit are integrally formed. 
         [0018]    The binder may include at least one selected from a group consisting of an inorganic binder and a porous binder. 
         [0019]    The regeneration unit may include a cyclone type housing, a cylindrical anode provided in the housing, and a cathode disposed on a central axis of the anode, and the Ion exchange material may be disposed between the anode and the cathode. 
         [0020]    The hardness component of the raw water may be adsorbed by the Ion exchange material of the softening unit and, at the same time, hydrogen ions (H + ) may be separated from the Ion exchange material to soften the raw water. 
         [0021]    The hydrogen ions (H + ) contained in the regeneration water supplied from the regeneration unit may be adsorbed by the Ion exchange material of the softening unit and, at the same time, a hardness component may be separated from the Ion exchange material to regenerate the Ion exchange material. 
         [0022]    The Ion exchange material may include at least one selected from a group consisting of zeolite, activated carbon, platinum (Pt), titanium (Ti), titanium oxide (TiO 2 ), carbon black ion exchange resin, and manganese (Mn). 
         [0023]    The Ion exchange material may be of a bead type or a powder type. 
         [0024]    The softening apparatus may further include a heater to heat water supplied to at least one selected from between the softening unit and the regeneration unit. 
         [0025]    In accordance with an aspect, a washing machine includes a washing device, a softening apparatus, and a controller to control operation of the washing device and the softening apparatus, wherein the softening apparatus includes a regeneration unit to generate regeneration water containing hydrogen ions (H + ) and a softening unit, including an Ion exchange material regenerated by the regeneration water, to convert raw water containing a hardness component into soft water containing hydrogen ions (H + ). 
         [0026]    When the washing device is operated in a sterilization mode, the controller may control the softening unit to generate soft water containing hydrogen ions (H + ) such that the soft water is used to sterilize or descale the washing device. 
         [0027]    The washing machine may further include a detergent supply device to supply detergent to the soft water discharged from the softening unit. 
         [0028]    When the washing device is operated in a washing mode, the controller may control the soft water discharged from the softening unit to be mixed with the detergent supplied from the detergent supply device such that the mixture is provided to the washing device. 
         [0029]    When the washing device is operated in a regeneration mode, the controller may control the regeneration unit to generate regeneration water containing hydrogen ions (H+) and to supply the regeneration water to the softening unit such that the Ion exchange material is regenerated. 
         [0030]    The washing machine may further include a channel unit to guide soft water generated by the softening unit or condensed water containing a hardness component. 
         [0031]    The washing machine may further include a hardness sensor to sense hardness of the soft water discharged from the softening unit. When the output of the hardness sensor reaches predetermined first reference hardness, the controller may control the regeneration mode to be executed. 
         [0032]    The washing machine may further include an electric conductivity sensor to sense electric conductivity of the soft water discharged from the softening unit. When the output of the electric conductivity sensor reaches predetermined second reference conductivity, the controller may control the regeneration mode to be executed. 
         [0033]    The washing machine may further include a flow rate sensor to sense flow rate of the soft water discharged from the softening unit. When the output of the flow rate sensor reaches predetermined third reference flow rate, the controller may control the regeneration mode to be executed. 
         [0034]    The controller may control the regeneration mode to be executed during the washing mode or the sterilization mode of the washing device. 
         [0035]    The regeneration unit may include a housing forming an external appearance and an electrode provided in the housing and the Ion exchange material may be coupled to one side of the electrode via a binder such that the regeneration unit and the softening unit are integrally formed. 
         [0036]    The binder may include at least one selected from a group consisting of an inorganic binder and a porous binder. 
         [0037]    The washing machine may further include a heater to heat water supplied to at least one selected from between the softening unit and the regeneration unit. 
         [0038]    In accordance with an aspect, an operation method of a washing machine including a washing device and a softening apparatus comprising an Ion exchange material having hydrogen ions (H + ) adsorbed thereby includes supplying raw water containing a hardness component to the softening apparatus to generate soft water containing hydrogen ions and providing the generated soft water to the washing device to wash or sterilize the washing device. 
         [0039]    The operation method may further include supplying detergent to the generated soft water and providing the soft water containing the detergent to the washing machine to wash the washing device. 
         [0040]    The operation method may further include heating the raw water containing the hardness component using a heater. 
         [0041]    The operation method may further include determining whether the softening apparatus is to be regenerated and, determining that the softening apparatus is to be regenerated, regenerating the softening apparatus. 
         [0042]    The determining whether the softening apparatus is to be regenerated may include at least one selected from among sensing a hardness value of the generated soft water, sensing electrical conductivity of the generated soft water, and total flow rate of the soft water generated by the softening apparatus. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0043]    These and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
           [0044]      FIG. 1  is a view showing construction of a softening apparatus according to an embodiment; 
           [0045]      FIG. 2  is a view showing a softening process of the softening apparatus according to the embodiment; 
           [0046]      FIG. 3  is a view showing a regeneration process of the softening apparatus according to the embodiment; 
           [0047]      FIG. 4  is a view showing the softening and regeneration processes performed in  FIGS. 2 and 3  as a chemical reaction formula; 
           [0048]      FIG. 5  is a view showing construction of a softening apparatus including a heater according to an embodiment; 
           [0049]      FIGS. 6A to 6C  are views showing positions where the heater may be installed in the softening apparatus shown in  FIG. 5 ; 
           [0050]      FIG. 7  is a graph showing the average adsorption amount of sodium ions based on concentration of sodium chloride per temperature; 
           [0051]      FIG. 8  is a graph showing a dissociation constant of water based on temperature; 
           [0052]      FIG. 9  is a view showing construction of a softening apparatus including a storage tank according to an embodiment; 
           [0053]      FIG. 10  is a view showing a softening apparatus including a softening unit and a regeneration unit, which are separated from each other, according to an embodiment; 
           [0054]      FIG. 11  is a view showing a cyclone type softening apparatus according to an embodiment; 
           [0055]      FIG. 12  is a view showing a washing machine including the softening apparatus of  FIG. 1 ; 
           [0056]      FIG. 13  is a control block diagram of the washing machine shown in  FIG. 12 ; and 
           [0057]      FIG. 14  is a flowchart showing a control process of a washing machine according to an embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0058]    Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. 
         [0059]    Embodiments relate to a softening apparatus that softens raw water containing a hardness component and a washing machine including the same. In this specification, supply water containing a hardness component introduced into the softening apparatus is referred to as raw water, raw water, from which the hardness component has been removed, discharged from a softening unit is referred to as soft water, supply water having high concentration of hydrogen ions (H + ) electrolyzed and supplied to an Ion exchange material is referred to as regeneration water, and regeneration water having high concentration of a hardness component through a regeneration process is referred to as condensed water for the convenience of description. The hardness component may include positive ions, such as calcium ions (Ca 2+ ) and magnesium ions (Mg 2+ ), having positive charges. Hereinafter, a description will be given on the assumption that the hardness component includes calcium ions and magnesium ions for the convenience of description. 
         [0060]    Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.  FIG. 1  is a view showing construction of a softening apparatus  100  according to an embodiment. 
         [0061]    Referring to  FIG. 1 , the softening apparatus  100  includes a housing  110  having an inlet port  101  and an outlet port  102 , a softening unit  120  having an Ion exchange material  121  to convert raw water into soft water, a regeneration unit  130  to regenerate the Ion exchange material  121  using hydrogen ions (H) generated during electrolysis of water, and channel units  141 ,  142 , and  143  to guide soft water discharged from the softening unit  120  or condensed water discharged from the regeneration unit  130 . In addition, the softening apparatus  100  may further include a detergent supply device  150  to supply detergent to the soft water discharged from the softening unit  120 . The softening unit  120  and the regeneration unit  130  are provided for softening and regeneration, respectively. The softening unit  120  and the regeneration unit  130  may be separated from each other. In this embodiment, however, a softening and regeneration element is integrally formed in the housing  110 . Consequently, the softening and regeneration device is referred to as the softening unit  120  when generating soft water through a softening process and as regeneration unit  130  when performing a regeneration process. 
         [0062]    Hereinafter, the respective elements of the softening apparatus  100  will be described in more detail. 
         [0063]    The housing  110  includes an inlet port  101  connected to a raw water pipe to allow raw water to be introduced therethrough and an outlet port  102  connected to a water discharge pipe to allow soft water to be discharged therethrough. The inlet port  101  may be formed at a central axis of the top of the housing  110  and the outlet port  102  may be formed at a central axis of the bottom of the housing  110 . The inlet port  101  and the outlet port  102  are provided with valves  140  to allow or block flow of raw water to be introduced into the inlet port  101  and soft water to be discharged to the inlet port  101 . During operation of the softening apparatus  100 , the valves  140  may be controlled to properly adjust introduction of raw water and discharge of soft water. 
         [0064]    The softening unit  120  is provided in the housing  110 . The softening unit  120  is an element to remove a hardness component from raw water introduced through the inlet port  101  of the softening apparatus  100  to soften the raw water. The softening unit  120  softens water based on ion exchange capability of the Ion exchange material  121 . The softening unit  120  may be integrally formed with or separated from the regeneration unit  130 . In  FIG. 1 , the softening unit  120  is integrally formed with the regeneration unit  130 . 
         [0065]    The Ion exchange material  121  may be, for example of a bead type or a powder type, but is not limited to those types. The Ion exchange material  121  may fill the softening unit  120 . The Ion exchange material  121  may be coupled to one side of an electrode  131 , specifically the surface of an anode via a binder. At least one selected from a group consisting of an inorganic binder and a porous binder may be used as the binder to increase the ion exchange amount of the Ion exchange material  121 . 
         [0066]    A bead type zeolite compound is obtained by adding a binder to powder type zeolite particles (Z) and forming the powder type zeolite particles in a spherical shape. Water easily passes through the bead type zeolite compound since gaps among the particles are large. However, the bead type zeolite compound has a smaller specific surface area than a powder type zeolite compound with the result that softening performance per unit weight may be deteriorated. The powder type zeolite compound has a large specific surface area with the result that softening performance per unit weight is excellent. However, gaps among the particles are small. When water passes through the powder type zeolite compound, therefore, differential pressure may greatly increase. 
         [0067]    Consequently, a proper sized zeolite compound may be used for the above reasons. Furthermore, activated carbon (C) may be coupled to the zeolite compound or the housing  110  may be designed to have a cyclone structure. In  FIGS. 1 and 2 , the Ion exchange material  121  is formed by coupling the activated carbon (C) to the zeolite compound. 
         [0068]    In addition, the Ion exchange material  121  may include at least one selected from a group consisting of an ion exchange material having zeolite, ion exchange resin, ion exchange thin film, ion exchange fiber, and at least one inorganic metal ion selected from a group consisting of aluminum (Al), zirconium (Zr), and silicon (Si) as central atoms and an ion exchangeable site on the surface thereof, a material formed by introducing a functional group or a polymer compound to the surface of zeolite or ion exchange resin, a compound formed by introducing an ion exchange group including zeolite to at least one selected from a group consisting of platinum (Pt), titanium (Ti), titanium oxide (TiO 2 ), manganese (Mn), carbon black, and zeocarbon. 
         [0069]    The regeneration unit  130  is an element to electrolyze raw water to remove hard impurities from the Ion exchange material  121 . More specifically, the regeneration unit  130  supplies hydrogen ions (H + ) generated during electrolysis of water to the Ion exchange material  121  to regenerate the Ion exchange material  121 . 
         [0070]    The regeneration unit  130  includes an electrode  131  to electrolyze raw water. The electrode  131  includes an anode  131   a  and a cathode  131   b  spaced apart from the anode  131   a . At least one anode  131   a  and at least one cathode  131   b  may be provided. More specifically, the anode  131   a  and the cathode  131   b  each may be formed in the shape, for example, of a circular electrode, a bar electrode, or a plate electrode. 
         [0071]    In  FIG. 1 , the anode  131   a  and the cathode  131   b  each are formed in the shape of a plate electrode for the convenience of description. Alternatively, the anode  131   a  may be formed in the shape of a circular electrode such that the anode  131   a  extends in a longitudinal direction and the cathode  131   b  may be formed in the shape of a bar electrode such that the cathode  131   b  is disposed inside the anode  131   a . In addition, pluralities of anodes  131   a  and cathodes  131   b  may be provided such that the anodes  131   a  and the cathodes  131   b  are alternately arranged. 
         [0072]    In addition, the regeneration unit  130  may include a diaphragm  160  disposed between the anode  131   a  and the cathode  131   b  to selectively transmit ions. The diaphragm  160  may include at least one selected from a group consisting of non-woven fabric, membrane, and ion exchange film. 
         [0073]    As needed, a plurality of regeneration units  130  may be provided to constitute a regeneration module. In this case, regeneration may be more rapidly and effectively performed. 
         [0074]    The channel units  141 ,  142 , and  143  guide soft water or condensed water discharged from the softening unit  120  or the regeneration unit  130 . Referring to  FIG. 1 , acid soft water obtained by removing a hardness component from raw material and condensed water containing a hardness component separated from the Ion exchange material  121  may be discharged from the anode  131   a  side based on the diaphragm  160  and alkali water may be discharged from the cathode  131   b  side. The channel units  141 ,  142 , and  143  guide soft water discharged from the softening apparatus  100  such that the soft water is properly supplied as described above. Components of soft water and condensed water will be explained in detail when operation of the softening apparatus  100  is described below. 
         [0075]    The channel units  141 ,  142 , and  143  may include a first channel unit  141 , a second channel unit  142 , and a third channel unit  143 . The first channel unit  141  guides acid soft water to be supplied to a supply unit of the detergent supply device  150 . The second channel unit  142  guides acid soft water to be moved to a position where sterilization and descaling are performed. The third channel unit  143  guides condensed water and alkali water to be discharged outside. 
         [0076]    The detergent supply device  150  is provided in the vicinity of the first channel unit  141 . The softening apparatus  100  supplies softened wash water to an apparatus connected to the softening apparatus  100  or including the softening apparatus  100 . The softening apparatus  100  may supply detergent to soft water through the detergent supply device  150 . 
         [0077]    Hereinafter, softening and regeneration processes and principles of the softening apparatus  100  with the above-stated construction according to the embodiment will be described in detail. 
         [0078]      FIG. 2  is a view showing a softening process of the softening apparatus  100  according to the embodiment,  FIG. 3  is a view showing a regeneration process of the softening apparatus  100  according to the embodiment, and  FIG. 4  is a view showing the softening and regeneration processes performed in  FIGS. 2 and 3  as a chemical reaction formula. 
         [0079]    Referring to  FIG. 2 , when raw water is introduced into the softening unit  120  through the inlet port  101 , the raw water reaches the Ion exchange material  121  filling the softening unit  120 . When the raw water reaches the Ion exchange material  121 , a hardness component (calcium ions (Ca 2+ ) or magnesium ions (Mg 2+ )) contained in the raw water is removed by the Ion exchange material  121  and soft water is discharged through an outlet port  102   a  of the housing  110 . That is, the raw water softening process is performed such that the hardness component of the raw water is adsorbed by the Ion exchange material  121  and, at the same time, a positive ion component is separated from the Ion exchange material  121 . 
         [0080]    The principle of ion exchange in the Ion exchange material  121  is related to the structure of the Ion exchange material  121 . In one embodiment, the Ion exchange material  121  includes a zeolite particle (Z) represented by structural formula 1. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0081]    Referring to structural formula 1, the zeolite particle (Z) has silicon and aluminum as central atoms. The aluminum component of the zeolite particle (Z) partially has negative charges and, therefore, may adsorb positive ions having positive charges. 
         [0082]    When raw water containing a hardness component (calcium ions (Ca 2+ ) and magnesium ions (Mg 2+ )) is introduced to an initial zeolite particle (Z) coupled to hydrogen ions (H + ) or sodium ions (Nat), therefore, ion exchange is performed between the hydrogen ions (H + ) and the calcium ions (Ca 2+ ) and the magnesium ions (Mg 2+ ). In addition, ion exchange is performed between the sodium ions (Nat) and the calcium ions (Ca 2+ ) and the magnesium ions (Mg 2+ ). 
         [0083]    Chemical reaction formulas 1 and 2 show a process in which the hardness component is adsorbed by the zeolite particle (Z). 
         [0000]    
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
     
         [0084]    The initial zeolite particle (Z) may include sodium ions (Nat) or hydrogen ions (H + ) based on kind thereof. However, the regeneration process is performed through ion exchange between high-concentration hydrogen ions (H + ) generated during electrolysis of water and calcium ions (Ca 2+ ) and magnesium ions (Mg 2+ ). As the regeneration process and the softening process are repeatedly performed, ion exchange is repeatedly performed between the hydrogen ions (H + ) and the calcium ions (Ca 2+ ) and the magnesium ions (Mg 2+ ). During ion exchange at the regeneration process and the softening process, the hydrogen ions (H + ) are mainly intervened. 
         [0085]    As concentration of hydrogen ions (H + ) of water increases, pH of the water decreases and the water is acidified. Acid is corrosive. The Ion exchange material  121  may be corroded due to such corrosiveness of acid. In the softening apparatus  100 , zeolite is repeatedly regenerated and used for a long period of time. Consequently, zeolite stable against acid may be used as the Ion exchange material  121 . 
         [0086]    When the softening process is performed for a predetermined amount of water, the regeneration process may be performed to remove impurities from the Ion exchange material  121 . That is, hard impurities may be removed from the Ion exchange material  121  through the regeneration process such that the softening apparatus  100  is continuously usable. 
         [0087]    Referring to  FIG. 3 , when raw water is introduced into the softening apparatus  100  through the inlet port  101  during the regeneration process, current is applied to the anode  131   a  and the cathode  131   b  of the regeneration unit  130 . As a result, the raw water is electrolyzed to generate hydrogen positive ions. 
         [0088]    When electric energy is applied to water such that the water is electrolyzed to perform an oxidation-reduction reaction, a reaction represented by chemical reaction formula 3 occurs at the anode  131   a  and a reaction represented by chemical reaction formula 4 occurs at the cathode  131   b.    
         [0000]      H 2 O→½O 2 +2H + +2 e   −   Chemical reaction formula 3
 
         [0000]      2H 2 O+ 2   e   − →H 2 +2OH −   Chemical reaction formula 4
 
         [0089]    Referring to chemical reaction formulas 3 and 4, regeneration water having high concentration of hydrogen ions (H + ) is generated from the anode  131   a . When the regeneration water is supplied to the Ion exchange material  121  provided in the vicinity of the anode  131   a , calcium ions (Ca 2+ ) and magnesium ions (Mg 2+ ) adsorbed by the Ion exchange material  121  are exchanged with the high-concentration hydrogen ions (H + ) to regenerate the Ion exchange material  121 . 
         [0090]    Meanwhile, a compound formed by coupling activated carbon (C) to zeolite particles (Z) may be used as the Ion exchange material  121 . Activated carbon (C) has a large specific surface area and high electric conductivity. When a compound formed by coupling activated carbon (C) to zeolite particles (Z) is used as the Ion exchange material  121 , therefore, the electrode  131  may have a large specific surface area. 
         [0091]    That is, when activated carbon (C) is not coupled to zeolite particles (Z), hydrogen ions (H + ) are mainly generated at the surface of the electrode. On the other hand, when activated carbon (C) is coupled to zeolite particles (Z), hydrogen ions (H + ) may be generated in the vicinity of the activated carbon (C) in addition to at the surface of the electrode. As a result, regeneration water having high-concentration hydrogen ions (H + ) may be obtained, thereby achieving more rapid regeneration of zeolite. 
         [0092]    A softening and regeneration cycle as shown in  FIG. 4  is derived from combination of the principles shown in  FIGS. 2 and 3 . In  FIG. 4 , a solid line indicates a softening process and a dotted line indicates a regeneration process. 
         [0093]    Referring to  FIG. 4 , zeolite particles (Z) may have a form of H x Y(s) or Na R Y(s). When raw water containing a hardness component (Ca 2+  or Mg 2+ ) is supplied to zeolite particles (Z) of the softening unit  120 , calcium ions (Ca 2+ ) or magnesium ions (Mg 2+ ) are adsorbed by the zeolite particles (Z) and, at the same time, a positive ion component, such as hydrogen ions (H + ) or sodium ions (Nat), is separated from the Ion exchange material  121 . After completion of the softening process, therefore, soft water is discharged from the anode  131   a  side. 
         [0094]    After completion of the softening process, a regeneration process may be periodically performed as needed. The regeneration process uses high-concentration hydrogen ions (H + ) generated during electrolysis of water. That is, a large amount of hydrogen ions (H + ) are generated from the anode  131   a  side during electrolysis of water. The hydrogen ions (H + ) are exchanged with the calcium ions (Ca 2+ ) or magnesium ions (Mg 2+ ) adsorbed by the Ion exchange material  121  to regenerate the zeolite particles (Z). After completion of the regeneration process, therefore, condensed water containing calcium ions (Ca 2+ ) and magnesium ions (Mg 2+ ) is discharged from the anode  131   a  side and alkali water containing a large amount of hydroxyl ions (OH) is discharged from the cathode  131   b  side. 
         [0095]    As a result, acid soft water containing hydrogen ions (H + ) generated after completion of the softening process may be used to sterilize or descale another apparatus connected to the softening apparatus  100  or detergent may be supplied to the soft water through the detergent supply device  150  such that the soft water may be used as wash water. Meanwhile, the condensed water and the alkali water generated after completion of the regeneration process are discharged outside through a drain. 
         [0096]    Next, construction and operation of a softening apparatus  100  including a heater  160  according to an embodiment will be described in detail.  FIG. 5  is a view showing construction of a softening apparatus  100  including a heater  160  according to an embodiment,  FIGS. 6A to 6C  are views showing positions where the heater  160  may be installed in the softening apparatus,  FIG. 7  is a graph showing the average adsorption amount of sodium ions (Nat) based on concentration of sodium chloride per temperature, and  FIG. 8  is a graph showing a dissociation constant of water based on temperature. 
         [0097]    Referring to  FIG. 5 , the softening apparatus  100  may further include a heater  160  in addition to the construction shown in  FIG. 1  and a repeated description thereof corresponding to  FIG. 1  will be omitted. 
         [0098]    The heater  160  is an element to heat raw water supplied to the regeneration unit  130 . During the regeneration process, the heater  160  may heat raw water supplied to the Ion exchange material  121  such that the raw water is easily electrolyzed. When the temperature of the Ion exchange material  121  is increased, calcium ions (Ca 2+ ) or magnesium ions (Mg 2+ ) may be easily separated from the Ion exchange material  121 . Consequently, a hardness component (Ca 2+  or Mg 2+ ) may be easily separated from the Ion exchange material  121  using this principle. 
         [0099]    More specifically, when temperature is changed from room temperature to high temperature, a dissociation constant of water is abruptly increased with the result that the water is easily electrolyzed. As the electrolysis result of the water, concentration of hydrogen ions (H + ) is increased and, therefore, the hydrogen ions (H + ) may be actively exchanged with the hardness component (Ca 2+  or Mg 2+ ) coupled to the Ion exchange material  121 . 
         [0100]    Referring to  FIGS. 6A to 6C , the heater  160  may be installed before the regeneration unit  130  and/or the softening unit  120  or in the vicinity of the regeneration unit  130  and/or the softening unit  120 . 
         [0101]      FIG. 6A  shows that the regeneration unit  130  and the softening unit  120  are integrally formed and  FIGS. 6B and 6C  show that the regeneration unit  130  generates and supplies hydrogen ions (H + ) to the softening unit  120  to perform regeneration. 
         [0102]    When the heater  160  is provided before the regeneration unit  130  and the softening unit  120  as shown in  FIG. 6A , raw water heated by the heater  160  is supplied to the regeneration unit  130  such that the raw water is electrolyzed by the regeneration unit  130 . Consequently, hydrogen ions (H + ) may be more easily obtained on the anode  131   a  side and regeneration water having a large amount of hydrogen ions (H + ) through electrolysis may be supplied to the Ion exchange material  121  such that a hardness component (Ca 2+  or Mg 2+ ) is easily separated from the Ion exchange material  121 . In addition, even when the heater  160  is provided in the vicinity of the regeneration unit  130  and the softening unit  120  as shown in  FIG. 6B , the above effects may be obtained. 
         [0103]    As previously described, the heater  160  may be provided at the softening unit  120  or the regeneration unit  130 . For example, as shown in  FIG. 6C , the heater  160  may be installed in the vicinity of the softening unit  120 . In this case, room-temperature raw water is supplied to the regeneration unit  130  such that the raw water is electrolyzed by the regeneration unit  130  and regeneration water obtained through electrolysis is supplied to the softening unit  120  such that the regeneration water is heated by the heater  160 . The heated regeneration water may be supplied to the Ion exchange material  121  such that a hardness component (Ca 2+  or Mg 2+ ) is easily separated from the Ion exchange material  121 . 
         [0104]    Referring to  FIG. 7 , the adsorption amount of sodium is greater at high temperature than at low temperature. This is because motive power is thermodynamically increased to the heat at high temperature and, therefore, an ion separation property is increased. 
         [0105]    The same principle may be applied to calcium ions (Ca 2+ ) and magnesium ions (Mg 2+ ). That is, when the Ion exchange material  121  is regenerated using high-temperature regeneration water during the regeneration process, an ion separation property of calcium ions (Ca 2+ ) and magnesium ions (Mg 2+ ) is increased. Consequently, calcium ions (Ca 2+ ) and magnesium ions (Mg 2+ ) may be easily removed from the Ion exchange material  121 . 
         [0106]    Referring to  FIG. 8 , a dissociation constant of water is abruptly increased when temperature is changed from room temperature to high temperature. Consequently, higher concentration of hydrogen ions (H + ) may be obtained at high temperature and, therefore, regeneration may be easily achieved. 
         [0107]    For example, a dissociation constant of water is 0.68*10 (−14)  at 20° C. On the other hand, a dissociation constant of water is 33*10 (−14) , which is about 48 times that at 20° C., at 85° C. When the heater  160  is installed such that high-temperature raw water is supplied to the Ion exchange material  121  containing high concentration of hydrogen ions (H + ) during the regeneration process, therefore, calcium ions (Ca 2+ ) and magnesium ions (Mg 2+ ) may be easily separated from the Ion exchange material  121 . 
         [0108]    Next, a softening apparatus  100  including a storage tank  170  according to an embodiment will be described in detail.  FIG. 9  is a view showing construction of a softening apparatus  100  including a storage tank  170  according to an embodiment. 
         [0109]    Referring to  FIG. 9 , the softening apparatus  100  may further include a storage tank  170  in addition to the construction shown in  FIG. 1  and a repeated description thereof corresponding to  FIG. 1  will be omitted for the convenience of description. 
         [0110]    The storage tank  170  stores soft water discharged from the softening unit  120  such that the soft water is supplied to the regeneration unit  130  during the regeneration process. 
         [0111]    In the softening apparatus  100  shown in  FIGS. 1 and 6 , raw water containing a large amount of a hardness component (Ca 2+  or Mg 2+ ) is supplied to the regeneration unit  130 . However, the regeneration process is performed such that high-concentration hydrogen ions (H + ) generated during electrolysis of water are supplied to the Ion exchange material  121 . When the hardness component (Ca 2+  or Mg 2+ ) is supplied to the Ion exchange material  121  during the regeneration process, therefore, ion exchange may be more effectively performed. In this embodiment, therefore, soft water is stored in the storage tank  170  during the softening process and then the soft water stored in the storage tank  170  is supplied to the regeneration unit  130  during the regeneration process. Consequently, the regeneration process may be more easily performed. 
         [0112]    Next, a softening apparatus  100  including a softening unit  120  and a regeneration unit  130 , which are separated from each other, according to an embodiment will be described in detail.  FIG. 10  is a view showing a softening apparatus  100  including a softening unit  120  and a regeneration unit  130 , which are separated from each other, according to an embodiment. 
         [0113]    Referring to  FIG. 10 , the softening apparatus  100  includes the construction shown in  FIG. 1 . However, the regeneration unit  130  is installed before the softening unit  120 . That is, the regeneration unit  130  and the softening unit  120  are separated from each other. Consequently, external appearances of the softening unit  120  and the regeneration unit  130  are defined by housings  110   a  and  110   b.    
         [0114]    A bead type zeolite compound is used as the Ion exchange material  121 . The Ion exchange material  121  fills a gap between the inlet port  101  and the outlet unit  102  inside the housing  110   a  of the softening unit  120 . 
         [0115]    The electrode  131  includes a plate-shaped anode  131   a  and a plate-shaped cathode  131   b  provided in the housing  110   b  of the regeneration unit  130 . The anode  131   a  and the cathode  131   b  are spaced apart from each other in a state in which the diaphragm  160  is disposed between the anode  131   a  and the cathode  131   b.    
         [0116]    Operation of the softening apparatus  100  is as follows. During the softening process of the softening apparatus  100 , raw water having passed through the regeneration unit  130  installed before the softening unit  120  is introduced into the softening unit  120 . At this time, electric power is not supplied to the electrode  131  of the regeneration unit  130 . As a result, the raw water introduced into the regeneration unit  130  passes through the regeneration unit  130  and is introduced into the softening unit  120 . The raw water introduced into the softening unit  120  is softened according to the same principle as shown in  FIG. 2 . 
         [0117]    After the softening process is performed several times, it may be necessary to regenerate the Ion exchange material  121  of the softening apparatus  100 . 
         [0118]    During the regeneration process of the Ion exchange material  121 , electric power is supplied to the electrode  131  of the regeneration unit  130  such that raw water introduced into the regeneration unit  130  is electrolyzed. When the raw water is electrolyzed, regeneration water having high concentration of hydrogen ions (H + ) is obtained. The regeneration water is supplied to the Ion exchange material  121  of the softening unit  120 . The hydrogen ions (H + ) of the regeneration water supplied to the Ion exchange material  121  are exchanged with a hardness component (Ca 2+  or Mg 2+ ) adsorbed by the Ion exchange material  121  to regenerate the Ion exchange material  121 . 
         [0119]    Next, a softening apparatus  100  according to an embodiment will be described in detail.  FIG. 11  is a view showing a cyclone type softening apparatus  100  according to an embodiment. 
         [0120]    Referring to  FIG. 11 , the softening apparatus  100  is configured such that the softening unit  120  and the regeneration unit  130  are integrally formed, the housing  110  is designed to have a cyclone structure, and a power type zeolite compound fills the housing  110 . In addition, the inlet port  101  is formed at one side of the housing  110  and the outlet port  102  is formed at the top of the housing  110 . 
         [0121]    Operation of the softening apparatus  100  with the above-stated construction is as follows. When raw water containing a hardness component (Ca 2+  or Mg 2+ ) is introduced into the housing  110  through the inlet port  101  during the softening process, cyclone is generated in the housing  110 . As a result, zeolite particles (Z) sink and the water, which is lighter than the zeolite particles (Z), is softened and discharged through the outlet port  102  due to the difference in density between the zeolite particles (Z) and the water 
         [0122]    After the softening process is performed several times, it may be necessary to regenerate the Ion exchange material  121  of the softening apparatus  100 . 
         [0123]    When raw water is introduced through the inlet port  101  of the housing  110  and electric power is supplied to the electrode  131  of the regeneration unit  130  to regenerate the Ion exchange material  121 , the raw water supplied to the regeneration unit  130  is electrolyzed and regeneration water having high concentration of hydrogen ions (H + ) is obtained. The regeneration water obtained by the regeneration unit  130  is supplied to the Ion exchange material  121  to regenerate the Ion exchange material  121 . 
         [0124]    Next, a washing machine including the softening apparatus  100  shown in  FIG. 1  will be described in detail. However, the softening apparatus  100  can be applied to any appliance, for example, a dishwasher or refrigerator, or a device that can benefit from softened water. 
         [0125]    The washing machine may include a washing device, a softening apparatus  100 , and a controller to control operation of the washing device and the softening apparatus  100 . The softening apparatus  100  may include a regeneration unit  130  to generate regeneration water containing hydrogen ions (H + ) and a softening unit  120 , including an Ion exchange material which is regenerated by the regeneration water, to convert raw water containing a hardness component into soft water containing hydrogen ions (H + ). The washing machine may include all kinds of apparatuses, such as a washer and a dishwasher, using for washing. Hereinafter, a washer will be described in detail by way of example for the convenience of description. 
         [0126]      FIG. 12  is a view showing a washing machine  200  including the softening apparatus  100  of  FIG. 1  and  FIG. 13  is a control block diagram of the washing machine  200  shown in  FIG. 12 . The washing machine  200  may include any one of the softening apparatuses  100  shown in  FIGS. 1 ,  5 , and  9  to  11 . Hereinafter, the washing machine  200  including the softening apparatus  100  shown in  FIG. 1  will be described in detail by way of example for the convenience of description. 
         [0127]    Referring to  FIGS. 12 and 13 , the washing machine  200  includes a softening apparatus  100 , channel units  141 ,  142 , and  143  to guide soft water discharged from the softening apparatus  100 , a plurality of valves  140  to allow or block flow of the soft water in the channel units  141 ,  142 , and  143 , an input unit  205  to allow input of a command to control the washing machine  200 , a sensor unit  210  to determine regeneration time, a washing tub  290  to perform washing, a drive unit  220  to drive the washing tub  290  and the softening apparatus  100 , and a controller  230  to control operation of the washing tub  290  and the softening apparatus  100 . In addition, the washing machine  200  may further include a drain  190 , which is a discharge passage of wash water discharged from the washing tub  290  and concentrated water and alkali water discharged from the softening apparatus  100  and a detergent supply device  150  to supply detergent to soft water generated by the softening apparatus  100 . 
         [0128]    The softening apparatus  100  includes a housing  110  having an inlet port  101  and an outlet port  102 , a softening unit  120  having an Ion exchange material  121  to convert raw water into soft water, and a regeneration unit  130  to electrolyze water to generate hydrogen ions (H+) and to supply the generated hydrogen ions (H + ) to the Ion exchange material  121  to regenerate the Ion exchange material  121 . Hereinafter, a repeated description of the softening apparatus  100  corresponding to  FIG. 1  will be omitted for the convenience of description. 
         [0129]    The input unit  205  is an element to allow input of a control command of the washing machine  200 . The input unit  205  may be of a button type or a touch type. The washing machine  200  may be operated in a sterilization mode, a washing mode, and a regeneration mode. Correspondingly, the input unit  205  may include a sterilization mode input unit  205 , a washing mode input unit  205 , and a regeneration mode input unit  205 . 
         [0130]    The sensor unit  210  may be provided in the housing  110  of the softening apparatus  100  or around the outlet port  102   a  to determine regeneration time of the softening apparatus  100 . More specifically, when the softening process is performed for a predetermined amount of water, the regeneration process may be performed to remove impurities from the Ion exchange material  121 . The sensor unit  210  senses a hardness component (Ca 2+  or Mg 2+ ) of soft water to determine regeneration time of the softening apparatus  100 . 
         [0131]    The sensor unit  210  may include at least one selected from among a hardness sensor, an electric conductivity sensor, a capacitive sensor, and a flow rate sensor. The hardness sensor senses a hardness component (Ca 2+  or Mg 2+ ) of soft water discharged from the softening unit  120 . The electric conductivity sensor senses change in electric conductivity based on the hardness component (Ca 2+  or Mg 2+ ) of the soft water discharged from the softening unit  120 . The flow rate sensor senses the amount of soft water treated by the softening unit  120  and outputs the sensing result to the controller  230 . 
         [0132]    The controller  230  controls the washing device to be operated in the sterilization mode, the washing mode, and the regeneration mode. After the softening and regeneration processes, the controller  230  controls flow of soft water and condensed water through the valves  140 . 
         [0133]    When a sterilization command is input through the input unit  205 , the sterilization mode may be executed. When the washing machine  200  is operated in the sterilization mode, the softening unit  120  may generate soft water containing hydrogen ions (H + ) such that the soft water is used to sterilize or descale the washing tub  290 . 
         [0134]    When a washing command is input through the input unit  205 , the washing mode may be executed. When the washing machine  200  is operated in the washing mode, soft water discharged from the softening unit  120  may be mixed with detergent supplied from the detergent supply device  150  such that the mixture is supplied to the washing tub  290 . 
         [0135]    When a regeneration command is input through the input unit  205  or it is determined according to a predetermined criterion that the regeneration mode is to be executed, the regeneration mode may be executed. When the washing machine  200  is operated in the regeneration mode, the regeneration unit  130  may generate regeneration water containing hydrogen ions (H + ) and supply the regeneration water to the softening unit  120  to regenerate the Ion exchange material. 
         [0136]    Hereinafter, a detailed description will be given of a regeneration time determination method of the washing machine  200  excluding a case in which the regeneration command is input through the input unit  205 . 
         [0137]    When the sensing result of the hardness sensor is output, the controller  230  may determine a hardness component (Ca 2+  or Mg 2+ ) of soft water according to the output signal of the hardness sensor. When the output of the hardness sensor reaches predetermined first reference hardness, the controller  230  may control the regeneration unit  130  to perform the regeneration process. 
         [0138]    In addition, when the sensing result of the electric conductivity sensor is output, the controller  230  may determine a hardness component (Ca 2+  or Mg 2+ ) of soft water according to the output signal of the electric conductivity sensor. When the output of the electric conductivity sensor reaches predetermined second reference conductivity, the controller  230  may control the regeneration unit  130  to perform the regeneration process. 
         [0139]    In addition, when the sensing result of the flow rate sensor is output, the controller  230  may check the amount of soft water treated by the softening unit  120  according to the output signal of the flow rate sensor. When the output of the flow rate sensor reaches predetermined third reference flow rate, the controller  230  may control the regeneration unit  130  to perform the regeneration process. 
         [0140]    Next, a description will be given of a soft water and condensed water flow control process after the softening process and the regeneration process. 
         [0141]    When the sterilization mode is input, soft water containing hydrogen ions (H + ) discharge from the softening unit  120  is supplied to a position where sterilization or descaling is needed. As previously described, the soft water is acid water containing a large amount of hydrogen ions (H + ). Consequently, the soft water may be introduced into the washing tub  290  through the second channel unit  142  to sterilize and descale the washing tub  290 . 
         [0142]    When the washing mode is input, soft water discharged from the softening unit  120  may be mixed with detergent supplied from the detergent supply device  150  such that the mixture is supplied to the washing tub  290 . In this case, soft water containing a large amount of hydrogen ions (H+) may be used as wash water. 
         [0143]    When the regeneration mode is input or it is determined that the regeneration mode is to be executed, electric power is applied to the electrode  131  to electrolyze water. Regeneration water containing high-concentration hydrogen ions (H + ) may be obtained through electrolysis of water. Concentrated water discharged after completion of the regeneration process may be discharged outside through the drain. 
         [0144]    Hereinafter, an operation method of the washing machine  200  will be described. 
         [0145]    The operation method of the washing machine  200  includes an operation of supplying raw water containing a hardness component to the softening apparatus  100  to generate soft water containing hydrogen ions and an operation of providing the generated soft water to wash or sterilize the washing device. The operation of providing the generated soft water to wash the washing device may further include an operation of supplying detergent to the generated soft water and providing the soft water containing the detergent to the washing device to wash the washing device. 
         [0146]    In addition, it may be necessary to periodically regenerate the Ion exchange material of the softening apparatus  100  included in the washing machine  200  after the softening process is performed several times. Upon determining that the Ion exchange material is to be regenerated, an operation of regenerating the softening apparatus  100  may be performed. 
         [0147]      FIG. 14  is a flowchart showing an operation method of a washing machine  200  according to an embodiment. Hereinafter, the operation method of the washing machine  200  as a washer will be described in more detail by way of example. 
         [0148]    Referring to  FIG. 14 , when raw water is supplied to the washing machine  200 , the softening unit  120  softens the raw water into soft water. That is, a hardness component (Ca 2+  or Mg 2+ ) is removed from the raw water while the raw water passes through the softening unit  120  ( 310  and  320 ). 
         [0149]    The hardness sensor senses hardness of the soft water discharged from the softening unit  120 . At an early stage of the softening process, the hardness component (Ca 2+  or Mg 2+ ) is hardly sensed. As the softening process is performed several times, the hardness component (Ca 2+  or Mg 2+ ) accumulates in the Ion exchange material  121 . As a result, hardness having a predetermined value or more may be sensed. Consequently, the hardness sensor periodically senses the hardness of the soft water output from the softening unit  120  and outputs the sensing result to the controller  230  ( 330 ). 
         [0150]    Upon receiving the output of the hardness sensor, the controller  230  determines an output value of the hardness sensor. Upon determining that the hardness component (Ca 2+  or Mg 2+ ) of the soft water discharged from the softening unit  120  has reached the predetermined first reference hardness, the controller  230  controls the regeneration unit to perform the regeneration process. On the other hand, upon determining that the hardness component (Ca 2+  or Mg 2+ ) of the soft water discharged from the softening unit  120  has not reached the predetermined first reference hardness, the controller  230  determines whether the sterilization mode has been input ( 340  and  350 ). 
         [0151]    Upon determining that the hardness component (Ca 2+  or Mg 2+ ) of the soft water discharged from the softening unit  120  has reached the predetermined first reference hardness, it is determined that the regeneration process is to be performed. Consequently, electric power is supplied to the electrode  131  of the regeneration unit  130  such that raw water introduced into the regeneration unit  130  is electrolyzed. When the raw water is electrolyzed, hydrogen ions (H + ) are generated and the hydrogen ions (H + ) are exchanged with the hardness component (Ca 2+  or Mg 2+ ) coupled to the Ion exchange material  121  to perform the regeneration process. When the regeneration process is completed, raw water is supplied to the softening unit  120  and the raw water is softened by the regenerated Ion exchange material  121  ( 342 ,  344 ,  310 , and  320 ). Concentrated water and alkali water generated during the regeneration process are discharged through the drain  190  via the third channel unit  143 . In addition, prestored soft water may be supplied to perform the regeneration process as previously described with reference to  FIG. 9 . 
         [0152]    Upon determining that the hardness component (Ca 2+  or Mg 2+ ) of the soft water discharged from the softening unit  120  has not reached the predetermined first reference hardness, the soft water discharged from the softening unit  120  is supplied to execute the sterilization mode or the washing mode (350). 
         [0153]    Upon determining that the sterilization mode has been input through the input unit  205 , the soft water discharged from the softening unit  120  is supplied to the washing tub  290  via the second channel unit  142  such that the soft water is used to sterilize and descale the washing tub  290  ( 350 ,  352 , and  354 ). 
         [0154]    Upon determining that the sterilization mode has not been input through the input unit  205 , it is determined that the washing mode has been input. Consequently, detergent is supplied to the soft water introduced into the first channel unit  141  through the detergent supply device  150 . The soft water containing the detergent is supplied to the washing tub  290  such that the soft water is provided for washing ( 350 ,  360 ,  362 , and  364 ). 
         [0155]    The operation method of the washing machine  200  is not limited to that shown in  FIG. 14 . The regeneration process may be performed after the washing process or the regeneration process may be directly performed through the input unit  205 . That is, the above-described operation method of the washing machine  200  may include all processes within a scope easily changeable by those skilled in the art. 
         [0156]    As is apparent from the above description, the softening apparatus and the washing machine according to the embodiments may have the following effects. 
         [0157]    First, a zeolite compound that has been used to perform ion exchange may be regenerated using hydrogen ions (H + ) generated using an electrochemical method such that the zeolite compound may be repeatedly used. 
         [0158]    In addition, the zeolite compound may be continuously regenerated without supply of an additional regeneration agent, thereby improving economical efficiency. 
         [0159]    Furthermore, hydrogen ions (H + ) generated during a softening process may be used for sterilization and descaling, thereby executing a sterilization mode separately from a washing mode. 
         [0160]    Although a few embodiments have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.