Patent Publication Number: US-9903029-B2

Title: Bipolar-electrode electrolytic cell

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation of U.S. patent application Ser. No. 14/007,429, entitled “BIPOLAR-ELECTRODE ELECTROLYTIC CELL,” filed on Sep. 25, 2013 (pending), which is a 371 of International Patent Application Serial No. PCT/JP2012/056378 filed on Mar. 13, 2012, which claims priority to Japanese Patent Application No. 2011-072048, filed on Mar. 29, 2011, the disclosures of which are hereby incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a bipolar-electrode electrolytic cell included in an electrolysis water-making apparatus which generates electrolysis sterilized water. Priority is claimed on Japanese Patent Application No. 2011-072048, filed Mar. 29, 2011, the content of which is incorporated herein by reference. 
     BACKGROUND ART 
     In the related art, in order to generate electrolysis sterilized water which sterilizes and cleans food or an apparatus for manufacturing food in a food manufacturing field or the like, an electrolytic water manufacturing apparatus including a bipolar-electrode electrolytic cell is used (for example, Patent Document 1). In the bipolar-electrode electrolytic cell, a large number of electrode plates formed from titanium oxide or the like are arranged, insulation spacers are respectively disposed between the electrode plates so as not to short-circuit the adjacent electrode plates, and unit cells are independently formed and respectively between the electrode plates. A catalyst coated on a base material of the electrode plate of the electrolytic cell is formed from noble metals such as platinum (Pt) or iridium (Ir), which are expensive. Thus, the cost can be reduced by coating the catalyst thin on a surface of titanium metal which is relatively inexpensive and has excellent strength, workability and corrosion resistance. In addition, since the generated materials are different from each other in a cathode and an anode, different catalysts may be used. Usually, the electrode plate of hydrochloric acid electrolysis which is obtained by coating, the catalyst such as Pr or Ir on the base material formed of titanium is used. Specifically, Pt or Ir is essential to generate chlorine gas on an anode surface and the life of the electrode is increased in proportion to the coated amount. Meanwhile, Pt or Ir is not essential to generate hydrogen gas on the cathode surface and the catalyst different from the anode surface may be coated. In addition, in a case where the base material is formed of titanium, hydrogen gas may be generated even though the coating of the catalyst is not present. Thus, coating only one surface of the electrode plate is coated can be used so that the simplest electrode in which both cathode and anode surfaces are present on the front and rear of one electrode plate is provided. Accordingly, in the assembly of the bipolar-electrode electrolytic cell, one plate surface on which platinum, iridium oxide or the like is coated, is directed to be a plus side, and then the electrode plate and the spacer are disposed. In other words, chloride is generated on the one plate surface and hydrogen is generated on the other plate surface. 
     CITATION LIST 
     Patent Literature 
     [Patent Document 1] Japanese Unexamined Patent Application, First Publication No. 2010-058052 
     SUMMARY OF INVENTION 
     Technical Problem 
     However, according to a bipolar-electrode electrolytic cell of the related art described above, an electrode plate is disposed on a spacer by observing the front and rear of a plate surface of the electrode plate and by determining the direction of the plate surface. Thus, the electrolytic cell may be assembled in which normal electrolysis cannot be performed by disposing the electrode plate on the spacer in a wrong direction. 
     In addition, the wrong disposition of the electrode plate described above leads to reduce electrolysis efficiency of the bipolar-electrode electrolytic cell in the early stage. 
     In addition, in order to prevent the wrong disposition of the electrode plate described above, it is necessary to dispose the electrode plate after sufficiently checking the front and rear of the electrode plate. Thus, the efficiency of assembly work of the bipolar-electrode electrolytic cell is reduced due to the determination of the front and rear of the plate surface of the electrode plate. 
     The invention has been accomplished in considering the above described problems and provides a bipolar-electrode electrolytic cell in which a direction of an electrode plate to a spacer is easily determined, wrong assembly of the bipolar-electrode electrolytic cell can be prevented easily and reliably, and reduction of an electrolysis efficiency in the early stage can be prevented. 
     Solution to Problem 
     The invention provides following means to solve the above problems. That is, a bipolar-electrode electrolytic cell according to a first invention of the present application includes a chassis; an electrode plate performing electrolysis in electrolyte solution and generating electrolyzed products; and a plate-shaped spacer having a concavity on which the electrode plate is disposed in which a unit cell, which is formed by connecting a plurality of spacers in which the electrode plate is disposed on the concavity so that one plate surface of the electrode plate is directed to one direction, is disposed inside the chassis. In addition, the bipolar-electrode electrolytic cell includes an engaged portion which is provided on any one side of the concavity of the spacer and the electrode plate; and an engaging portion which is formed on the other portion with respect to the one side portion. The engaged portion and the engaging portion are positioned so as to correspond to each other, and are formed to dispose the electrode plate inside the concavity, when the one plate surface of the electrode plate is disposed on the concavity toward the one direction. Furthermore, the engaged portion and the engaging portion are positioned so as not to correspond to each other, and are prevented from disposing the electrode plate inside the concavity, when the other plate surface of the electrode plate is disposed on the concavity toward the one direction. 
     In bipolar-electrode electrolytic cell of a second invention of the application according to the first invention, the engaged portion is a projecting wall or a projecting part formed on the concavity, and 
     wherein the engaging portion is a cut-out portion or a hole formed on the electrode plate. 
     In bipolar-electrode electrolytic cell of a third invention of the application according to the first or second invention, the spacer has a latching portion formed on the plate surface and a latched portion which latches the latching portion of another spacer and performs connection thereto. 
     In bipolar-electrode electrolytic cell of a fourth invention of the application according to the third invention, a fitting convex portion is formed on the one plate surface of the spacer and a fitting concave portion, which is fitted into the fitting convex portion of the one plate surface of the other spacer and holds the connection between spacers, is formed on the other plate surface of the spacer. 
     Advantageous Effects of Invention 
     According to the bipolar-electrode electrolytic cell of the invention, the engaged portion and the engaging portion are formed on the electrode plate and the spacer, respectively so that the engaged portion and the engaging portion are positioned to correspond to each other and can dispose the electrode plate inside the concavity, when one plate surface of the electrode plate is disposed on the concavity toward one direction. Meanwhile, the engaged portion and the engaging portion are formed on the electrode plate and the spacer, respectively so that the engaged portion and the engaging portion are positioned so as not to correspond to each other and are prevented from disposing the electrode plate inside the concavity, when the other plate surface of the electrode plate is disposed on the concavity toward one direction. In other words, the electrode plate cannot be assembled to the spacer other than a predetermined direction of the electrode plate. Accordingly, when the front and rear of the electrode plate is provided in distinguished way, the electric plate does not get disposed in a wrong direction. Accordingly, corrosion of the electrode plate can be avoided due to a wrong disposition of the electrode plate, and reduction of the electrolysis efficiency of the bipolar-electrode electrolytic cell in the early stage can be avoided. In addition, peeling of the coating of the electrode plate can be avoided, and the short life of the electrode plate is prevented. 
     In addition, according to the bipolar-electrode electrolytic cell of the invention, the electrolysis efficiency of the bipolar-electrode electrolytic cell can be maintained for a long period. 
     In addition, according to the bipolar-electrode electrolytic cell of the invention, since determination of the direction of the electrode plate is easily performed, the assembly of the bipolar-electrode electrolytic cell can be performed simply and efficiently. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a view illustrating a bipolar-electrode electrolytic cell illustrated as a first embodiment of the invention, and is an exploded perspective view of the bipolar-electrode electrolytic cell viewed from one direction. 
         FIG. 2  is a vertical cross-sectional view of the bipolar-electrode electrolytic cell illustrated as the first embodiment of the invention. 
         FIG. 3A  is a view illustrating a spacer of the bipolar-electrode electrolytic cell illustrated as the first embodiment of the invention, and is a front view of the spacer. 
         FIG. 3B  is a view illustrating the spacer of the bipolar-electrode electrolytic cell illustrated as the first embodiment of the invention, and is a side view of the spacer. 
         FIG. 3C  is a view illustrating the spacer of the bipolar-electrode electrolytic cell illustrated as the first embodiment of the invention, and is a rear view of the spacer. 
         FIG. 4A  is a view illustrating the spacer of the bipolar-electrode electrolytic cell illustrated as the first embodiment of the invention, and is a perspective view of the spacer viewed from in a rear direction. 
         FIG. 4B  is a view illustrating the spacer of the bipolar-electrode electrolytic cell illustrated as the first embodiment of the invention, and is a perspective view of the spacer viewed from in a front direction. 
         FIG. 5A  is a view illustrating an electrode plate of the bipolar-electrode electrolytic cell illustrated as the first embodiment of the invention, and is a front view of the electrode plate. 
         FIG. 5B  is a view illustrating the spacer of the bipolar-electrode electrolytic cell illustrated as the first embodiment of the invention, and is a front view of the spacer into which the electrode plate illustrated in  FIG. 5A  is fitted. 
         FIG. 5C  is a view illustrating the electrode plate of the bipolar-electrode electrolytic cell illustrated as the first embodiment of the invention, and is a rear view of the electrode plate. 
         FIG. 5D  is a view illustrating the spacer of the bipolar-electrode electrolytic cell illustrated as the first embodiment of the invention, and is a front view of the spacer. 
         FIG. 6  is an enlarged perspective view illustrating a connection state between the spacers of the bipolar-electrode electrolytic cell illustrated as the first embodiment of the invention. 
         FIG. 7  is an explanatory view illustrating a connection method of the electrode plate and the spacer of the bipolar-electrode electrolytic cell illustrated as the first embodiment of the invention. 
         FIG. 8  is a perspective view illustrating a connected state of the electrode plate and the spacer of the bipolar-electrode electrolytic cell illustrated as the first embodiment of the invention. 
         FIG. 9A  is a view illustrating a modification example of the electrode plate of the bipolar-electrode electrolytic cell illustrated as the first embodiment of the invention, and is a front view of the electrode plate. 
         FIG. 9B  is a view illustrating a modification example of the spacer of the bipolar-electrode electrolytic cell illustrated as the first embodiment of the invention, and is a front view of the spacer into which the electrode plate is illustrated in  FIG. 9A . 
         FIG. 10A  is a view illustrating the electrode plate of the bipolar-electrode electrolytic cell illustrated as a second embodiment of the invention, and is a front view of the electrode plate. 
         FIG. 10B  is a view illustrating the spacer of the bipolar-electrode electrolytic cell illustrated as the second embodiment of the invention, and is a front view of the spacer into which the electrode plate is fitted illustrated in  FIG. 10A . 
         FIG. 10C  is a view illustrating the electrode plate of the bipolar-electrode electrolytic cell illustrated as the second embodiment of the invention, and is a rear view of the electrode plate. 
         FIG. 10D  is a view illustrating the spacer of the bipolar-electrode electrolytic cell illustrated as the second embodiment of the invention, and is a front view of the spacer. 
         FIG. 11A  is a view illustrating the electrode plate of the bipolar-electrode electrolytic cell illustrated as a third embodiment of the invention, and is a front view of the electrode plate. 
         FIG. 11B  is a view illustrating the spacer of the bipolar-electrode electrolytic cell illustrated as the third embodiment of the invention, and is a front view of the spacer fitted into the electrode plate illustrated in  FIG. 11A . 
         FIG. 11C  is a view illustrating the electrode plate of the bipolar-electrode electrolytic cell illustrated as the third embodiment of the invention, and is a rear view of the electrode plate. 
         FIG. 11D  is a view illustrating the spacer of the bipolar-electrode electrolytic cell illustrated as the third embodiment of the invention and is a front view of the spacer. 
         FIG. 12A  is a view illustrating a modification example of the electrode plate of the bipolar-electrode electrolytic cell illustrated as the first embodiment of the invention, and is a front view of the electrode plate. 
         FIG. 12B  is a view illustrating a modification example of the spacer of the bipolar-electrode electrolytic cell illustrated as the first embodiment of the invention, and is a front view of the spacer into which the electrode plate is fitted illustrated in  FIG. 12A . 
         FIG. 13A  is a view illustrating a modification example of the electrode plate of the bipolar-electrode electrolytic cell illustrated as the second embodiment of the invention, and is a front view of the electrode plate. 
         FIG. 13B  is a view illustrating a modification example of the spacer of the bipolar-electrode electrolytic cell illustrated as the second embodiment of the invention, and is a front view of the spacer into which the electrode plate is fitted illustrated in  FIG. 13A . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, an embodiment of a bipolar-electrode electrolytic cell of the invention will be described referring to the drawings. 
     First Embodiment 
       FIG. 1  is a view illustrating a first embodiment of the bipolar-electrode electrolytic cell according to the invention and is an exploded perspective view of a bipolar-electrode electrolytic cell  1  viewed from one direction. As illustrated in  FIG. 1 , the bipolar-electrode electrolytic cell  1  has a plurality of electrode plates  3  and a plurality of spacers  4  inside a chassis  2 . 
     The chassis  2  includes side plates  5 A and  5 B, and a body  6 . They are formed from a synthetic resin such as vinyl chloride resin, carbonate resin and acrylic resin. 
     The side plates  5 A and  5 B are plate-shaped members which appear to have a rectangular shape with a predetermined thickness. Electrode through holes  7 , which pass through the center portion of the side plates  5 A and  5 B in the thickness direction thereof, respectively, are formed in the side plates  5 A and  5 B. In addition, at a lower portion of the side plate  5 A, a supplying hole  8  for supplying an electrolyte solution which passes through the thickness direction thereof is formed, and at an upper portion of the side plate  5 B, an extracting hole  9  for extracting electrolyzed products which passes through the thickness direction thereof is formed. 
       FIG. 2  is a vertical cross-sectional view of the bipolar-electrode electrolytic cell  1  in an assembled state and illustrates a cross-section in the center of the electrode through hole  7  in  FIG. 1 . As illustrated in  FIG. 2 , the side plates  5 A and  5 B have engaging concavities  11  formed on inner surfaces thereof which are opposed, respectively, and have concave portions  12  formed on the center portion of the outer surfaces thereof, respectively. In addition, the supplying hole  8  includes a large diameter portion  8   a  and a small diameter portion  8   b , and the extracting hole  9  includes a large diameter portion  9   a  and a small diameter portion  9   b . In addition, the center portion of the inner surface of the side plate  5 A has a concavity  13  to fit the electrode plate  3 . 
     The body  6  is a cylindrical member. The side plate  5 A is fixed to one end portion of the body  6  and the side plate  5 B is fixed to the other end portion thereof. 
     The electrode plate  3  is a plate-shaped member made from a metal such as titanium alloy. For example, coating of platinum for the anode is applied to one plate surface  3   a  of the electrode plate  3 . It is desirable that Coating for the cathode is applied to the other plate surface  3   b . However, in the first embodiment, the coating is not applied to the other plate surface  3   b.    
     In addition, as illustrated in  FIG. 1 , the electrode plate  3  is formed in a substantially square shape viewed in a plan view. Furthermore, one end side of an outer periphery of the electrode plate  3  has a cut-out portion  10 A of which a shape of the periphery has a substantially U shape. 
     The cut-out portion  10 A is an engaging portion which is paired with an engaged portion of the spacer  4  described below. If the electrode plate  3  is directed so that the outer periphery having the cut-out portion  10 A is positioned on the upper end when the one plate surface  3   a  of the electrode plate  3  is viewed in a plan view, the cut-out portion  10 A is formed to open to the upper side in the right end side of the electrode plate  3 . 
     Each electrode plate  3 ,  3  . . . is disposed side by side in such a manner that the one plate surface  3   a  on which the coating is applied is directed in one direction between the side plates  5 A and  5 B which are disposed facing each other having a predetermined dimensions. As illustrated in  FIG. 2 , metal electrode bars  21 A and  21 B are fixed to center portion of the electrode plate  3  which is disposed on both ends in each electrode plate  3 ,  3  . . . . 
     Heads  22  are formed on one end portion in the electrode bars  21 A and  21 B, and male thread portions  23  are formed on the outer surface of the other end portion. In addition, the Heads  22  are fixed to the center portion of the electrode plate  3 . 
     As illustrated in  FIG. 1 , the spacer  4  is a plate-shaped member formed from a synthetic resin such as vinyl chloride resin and carbonate resin, and is formed in a circular shape when viewed in a plan view so as to fall into the inside of the cylindrical body  6 . Each spacer  4 ,  4  . . . is disposed between each electrode plate  3 ,  3  . . . so as to be disposed alternately with each electrode plate  3 ,  3  . . . , and is disposed side by side in such a manner that each one plate surface thereof is directed in one direction between the side plates  5 A and  5 B. 
     The spacer  4  is illustrated in  FIGS. 3A to 3C, 4A and 4B . As illustrated in the figures, the spacer  4  is a circular plate-shaped member and has a hollow hole  24  which passes through the center portion of the plate surface in a direction (in other words, the thickness direction) between the plate surfaces. A contour of the hollow hole  24  is a square when viewed in a plan view. In addition, a dimension of each side configuring the contour of the hollow hole  24  is slightly smaller than the dimension of each side configuring the outer periphery of the electrode plate  3  described above. 
     The one plate surface  4   a  of the spacer  4  has a concavity  25  which is recessed in the thickness direction thereof along an inner wall surface of the hollow hole  24 . In other words, the concavity  25  is formed with a constant width dimension substantially along each side of the hollow hole  24  to be recessed in the thickness direction of the spacer  4 , and includes four concave portions  25   a  to  25   d  along each side thereof. 
     A bottom surface y of one end side of the concave portion  25   a  has a projecting part  35  protruding in the direction (the thickness direction) between the plate surfaces  4   a  and  4   b  of the spacer  4 . As illustrated in  FIG. 4B , the projecting part  35  is an engaged portion which is formed in a substantially circular column shape. As illustrated in  FIGS. 5A and 5B , when the other plate surface  3   b  of the electrode plate  3  is opposite to the bottom surface y of the concavity  25 , since the cut-out portion  10 A of the electrode plate  3  and the projecting part  35  of the spacer  4  are positioned and engaged corresponding to each other, the electrode plate  3  can be disposed inside the concavity  25 . As illustrated in  FIGS. 10C and 10D , when the coated one plate surface  3   a  is opposite to the bottom surface y of the concavity  25 , the cut-out portion  10 A of the electrode plate  3  and the projecting part  35  of the spacer  4  are not positioned corresponding to each other. In other words, since the engagement position (the engagement position of the cut-out portion  10 A and the projecting part  35  each other) of the electrode plate  3  and the spacer  4  do not fit each other, disposition of the electrode plate  3  inside the concavity  25  is prevented. 
     In other words, when the other plate surface  3   b  of the electrode plate  3  is opposite to the bottom surface y of the concavity  25  (in a case of  FIG. 5A ), since the positions of the projecting part  35  of the spacer  4  and the cut-out portion  10 A of the electrode plate  3  illustrated in  FIG. 5B  correspond to each other, both can be engaged. Meanwhile, when the electrode plate  3  illustrated in  FIG. 5A  is turned over and directed as illustrated in  FIG. 10C , since the positions of the projecting part  35  and the cut-out portion  10 A are not aligned with each other even though the other plate surface  3   b  is rotated to a certain angle, the electrode plate  3  contacts the projecting part  35  and the electrode plate  3  cannot be disposed inside the concavity  25 . 
     The concavity  25  is provided in the periphery of the projecting part  35  by rounding the circumference thereof so as to bypass the projecting part  35 . 
     As described above and as illustrated in  FIGS. 5A and 5B , only when the electrode plate  3  is directed in one direction, the electrode plate  3  can be fitted inside the concavity  25  of the spacer  4 . 
     In addition, the concavity  25  has a rectangular shape substantially along each side of the hollow hole  24 . The dimension outside of each side of the rectangular shape is slightly larger than the dimension of each side of the electrode plate  3 . Accordingly, the electrode plate  3  is fitted inside the concavity  25  without a clearance and the electrode plate  3  is fixed so as not to move in a direction along the plate surface of the spacer  4 . In addition, the depth of the concavity  25  in the thickness direction is substantially the same dimension as the thickness of the electrode plate  3 . Accordingly, when the electrode plate  3  is fitted, the plate surface  3   a  of the electrode plate  3  and the plate surface  4   a  of the spacer  4  have the same surface as each other. 
     As illustrated in  FIGS. 4A and 4B , in the spacer  4 , latching portions  26  and  26  are formed on upper and lower portions of the hollow hole  24 , and latched portions  27  and  27 , which latch the latching portions  26  and  26 , are formed on the periphery portion of both sides in the right and left of the hollow hole  24 . As illustrated in  FIG. 6 , the latching portion  26  and the latched portion  27  make the adjacent spacers  4  and  4  to be coupled with each other. Each of the spacers  4  and  4  is connected and coupled by latching the latching portions  26  and  26  of the other spacer  4  to the latched portions  27  and  27  of the one spacer  4  in the spacers  4  and  4  which are adjacent to each other. 
     As illustrated in  FIGS. 4A and 4B , the latched portion  27  is formed on the periphery portion of the spacer  4  and includes a concave portion  27   a  which is recessed in the hollow hole  24  side of the spacer  4  and in which the latching portion  26  is entered, and a fitting concavity  27   b  which is recessed in the thickness direction of the spacer  4  in the lateral direction of the outer periphery direction of the concave portion  27   a.    
     The latching portion  26  is formed on the peripheral portion which is rotated 90 degrees from a position in which the latched portion  27  is formed. The latching portion  26  includes a rising wall portion  26   a  which rises from the plate surface  4   a  and an extending portion  26   b  which is bent laterally from the rising wall portion  26   a  so as to be parallel to the plate surface  4   a  and along the outer periphery of the spacer  4 . 
     As illustrated in  FIG. 6 , the thickness of the extending portion  26   b  is formed of the same dimension as the depth dimension of a recess from the other plate surface  4   a  of the other spacer  4  to the fitting concavity  27   b . When the extending portion  26   b  of the latching portion  26  is overlapped and latched on the fitting concavity  27   b  of the latched portion  27 , the plate surface  26   c  of the extending portion  26   b  and the plate surface  4   a  of the other spacer  4  have substantially the same surface as each other. In addition, lower side of the extending portion  26   b  is a space portion S. 
     A fitting convex portion  36  is formed on the side of circumferential direction of the space portion S which is positioned on the lower side of the extending portion  26   b . Meanwhile, a fitting concave portion  37 , which is fitted with the fitting convex portion  36  when the latching portion  26  of one spacer  4  is latched on the latched portion  27  of the other spacer  4  which are adjacent to each other, is formed on the side of the fitting concavity  27   b  of the latched portion  27 . 
     In addition, the latching portion  26  of the spacer  4  of the plurality of spacers  4 ,  4  . . . , which is nearest to the side plate  5 B, is latched on a latched portion (not illustrated) formed on the side plate  5 B. Meanwhile, the latched portion  27  of the spacer  4 , which is nearest to the side plate  5 A, is latched on a latching portion (not illustrated) formed on the side plate  5 A. 
     In addition, as illustrated in  FIG. 4B , the spacer  4  has liquid through holes  28 ,  28  . . . , through which electrolyte solution passes, formed outside the center portion of the concave portions  25   a  and  25   c  which forms the concavity  25  in the right-left direction, and outside of the center portion of the convex portions  25   b  and  25   d  in the up-down direction, respectively. 
     The liquid through hole  28  is a hole which passes through in the direction between the plate surfaces  4   a  and  4   b  (the thickness direction) of the spacer  4 . A flow passage  30  formed on the plate surface  4   b  connects between the liquid through hole  28  and the hollow hole  24 , and the electrolyte solution introduced in the liquid through hole  28  is guided inside the hollow hole  24  through the flow passage  30  as described below. 
     As illustrated in  FIG. 4A , the flow passage  30  is a groove formed on the plate surface  4   b . As illustrated in  FIG. 3C , the flow passage  30  includes a groove  30   a  which is straightly extended from the liquid through hole  28  toward the hollow hole  24  and grooves  30   b  and  30   c  which are extended from the liquid through hole  28  along the end periphery of the hollow hole  24  in both directions, and which are bent in an intermediate portion thereof and then are extended toward the hollow hole  24 . 
     In addition, as illustrated in  FIG. 2 , the liquid through hole  28 , which is positioned on the lower portion of an unit cell C when disposed inside the chassis  2 , is an inlet which supplies the electrolyte solution. In addition, the liquid through hole  28 , which is positioned on the upper portion of the unit cell C is an outlet of the electrolyzed products of the electrolyte solution. Furthermore, the liquid through holes  28  positioned on the right and left of the unit cell C are liquid-level adjustment holes which communicate with the inside of each unit cell C through the flow passage  30  and adjust a liquid level of the electrolyte solution which invades in the unit cell C. 
     The bipolar-electrode electrolytic cell  1  described above is assembled as follows. First, as illustrated in  FIG. 5B , the other plate surface  3   b  on which the coating is not applied is opposite to the bottom surface y of the concavity  25 , and the electrode plate  3  is disposed inside the concavity  25  so that the cut-out portion  10 A of the electrode plate  3  is directed in the engagement direction with the projecting part  35  of the spacer  4 . At this time, as illustrated in  FIG. 5C , when the direction of the electrode plate  3  is opposite to the direction described above, in other words, when the one plate surface  3   a  on which the coating is applied is disposed to be opposite to the bottom surface y of the concavity  25 , since the positions of the cut-out portion  10 A and the projecting part  35  are not aligned with each other, the disposition of the electrode plate  3  on the concavity  25  is prevented by the projecting part  35 . 
     Then, as illustrated in  FIG. 7 , the spacer  4  on which the electrode plate  3  is disposed is overlapped and fixed to the other spacer  4  on which the electrode plate  3  is disposed. In other words, the latching portion  26  of the one spacer  4  enters the concave portion  27   a  of the latched portion  27  of the other spacer  4 . Therewith, a front end of the extending portion  26   b  of the latching portion  26  is latched on a front end of the fitting concavity  27   b  of the latched portion  27 , and the plate surfaces  4   a  and  4   b  of the spacers  4  and  4  which are opposite to each other, are approaching each other. As a result, the fitting convex portion  36  formed on the plate surface  4   a  of the one spacer  4  contacts the plate surface  4   b  of the other spacer  4 , and close contact between the plate surfaces  4   a  and  4   b  of the spacers  4  and  4  which are linked with each other is prevented. Therewith, the latching portion  26  is elastically deformed to outside the plate surface  4   a  of the one spacer  4  by the fitting concavity  27   b  of the latched portion  27 . In addition, the fitting concavity  27   b  of the latched portion  27  is elastically deformed to outside the plate surface  4   b  of the other spacer  4  by the latching portion  26 . 
     In this state, when the one spacer  4  is slid so as to relatively move to the other spacer  4 , the fitting convex portion  36  fits with the fitting concave portion  37 . Accordingly, plate surfaces  4   a  and  4   b  of the spacers  4  and  4  come into close contact with each other, and the extending portion  26   b  and the fitting concavity  27   b  contact. As a result, the spacers  4  and  4  are fixed to each other so as not to move. At this time, peripheral portion of each electrode plate  3  is covered by adjacent spacer  4 . Thus, each electrode plate  3  is held so as not to move inside the concavity  25  of the spacer  4  into which each electrode plate  3  is fitted. 
     As described above, a connected body M of the spacers  4 ,  4  . . . is obtained in which the electrode plate  3  illustrated in  FIG. 8  is assembled by sequentially connecting the spacers  4  and  4 . 
     Then, as illustrated in  FIG. 2 , the electrode bar  21 A fixed to the electrode plate  3  which is the nearest to the side plate  5 A passes through the electrode through hole  7  of the side plate  5 A, and the electrode bar  21 B fixed to the electrode plate  3  which is the nearest to the side plate  5 B passes through the electrode through hole  7  of the side plate  5 B. Then, the electrode plate  3  which is nearest to the side plate  5 B is inserted into the concavity  25  of the spacer  4  positioned one end side of the connected body M, and the body  6  is covered on the connected body M, and the side plate  5 A is aligned so that the supplying hole  8  and the liquid through hole  28  communicate with each other. Then, in a state where a washer  43  and a spring washer  44  are interposed on the male thread portion  23  of each of electrode bars  21 A and  21 B, a nut  45  is fastened. Accordingly, the side plate  5 A, the body  6 , the side plate  5 B, and the spacers  4 ,  4  . . . are firmly fixed. In addition, the electrode plate  3  which is nearest to the side plate  5 A is fitted inside the concavity  13  of the side plate  5 A. 
     In the above configuration, the liquid through holes  28  of each spacer  4  communicate with each other. In addition, the liquid through hole  28  of the liquid through holes  28  communicating with each other, which is positioned on the lower side thereof, communicates with the supplying hole  8  of the side plate  5 A, and the liquid through hole  28  positioned on the upper side thereof communicates with the extracting hole  9  of the side plate  5 B. 
     In addition, the hollow hole  24  of each spacer  4  is covered by two sheets of the adjacent electrode plates  3  and  3  and then a space is formed. The inside of the space is the unit cell C in which the electrolyte solution is electrolyzed. 
     In addition, the flow passage  30  of each spacer  4  is covered by the adjacent spacer  4  and the electrode plate  3  which is fitted into the spacer  4 . Accordingly, the flow passage  30  is a fluid passage communicating the liquid through hole  28  and the inside of the hollow hole  24 . 
     In addition, the liquid through hole  28  and the flow passage  30  communicating with the liquid through hole  28  which are positioned on both sides of the right and left of the spacer  4 , other than the liquid through holes  28  and  28  communicating with the supplying hole  8  and the extracting hole  9 , are covered by the adjacent spacer  4  and the electrode plate  3  fitted into the spacer  4 . Accordingly, the flow passage  30  is a fluid passage communicating with the inside of the liquid through hole  28  and the inside of the hollow hole  24 . As a result, the insides of the hollow holes  24  of each spacer  4  communicate with each other. 
     Next, production of the electrolyzed products in the bipolar-electrode electrolytic cell  1  described above will be described referring to  FIG. 2 . First, the electrolyte solution is supplied to the supplying hole  8 . The electrolyte solution is flowed into the liquid through hole  28  provided on the lower side of each spacer  4  and flowed into the unit cell C through the flow passage  30  of each spacer  4  so that the spacers  4  communicate with each other. When the electrolyte solution reaches a predetermined amount inside the unit cell C, electricity is applied between the electrode bars so that the electrode bars  21 A and  21 B are the anode and the cathode, respectively. As a result, the electrolyte solution is electrolyzed on the one plate surface  3   a  of the electrode plate  3 , and the electrolyzed products of a turbid state of a gas such as chlorine and a liquid inside the unit cell C, or the electrolyzed products which is mainly formed from chlorine or the like, are provided. The electrolyzed products reach inside the liquid through hole  28  of the upper side thereof configuring the outlet from the inside of the unit cell C via the flow passage  30  of each spacer  4 , and the electrolyzed products are extracted through the extracting hole  9 . 
     In this case, as described above, the plate surface  3   b  of the electrode plate  3  on which the coating is not applied is disposed so as to necessarily oppose the bottom surface y of the concavity  25  of the spacer  4 . In other words, when the electricity is applied between the electrode bars  21 A and  21 B as described above, the one plate surface  3   a  on which the coating is applied for the anode is always the plus side, and normal electrolysis can be performed because chlorine is generated on the plate surface  3   a . In addition, reduction of the electrolysis efficiency of the bipolar-electrode electrolytic cell  1  can be prevented over a long period. 
     As described above, according to the bipolar-electrode electrolytic cell  1 , since the projecting part  35  and the cut-out portion  10 A are positioned at the corresponding positions each other when the other plate surface  3   b  of the electrode plate  3  is opposite to the bottom surface y of the concavity  25 , the electrode plate  3  can be positioned inside the concavity  25 . On the other hand, since the projecting part  35  and the cut-out portion  10 A are not positioned at the corresponding positions of each other when the one plate surface  3   a  of the electrode plate  3  is opposite to the bottom surface y of the concavity  25 , the positions thereof are not aligned to each other, and the disposition of the electrode plate  3  inside the concavity  25  is prevented. In other words, the electrode plate  3  cannot be assembled in the spacer  4  in a direction which is opposite to a predetermined direction. Accordingly, since the front and rear sides of the electrode plate  3  are distinguished each other, the electrode plate  3  is not disposed on the spacer  4  in a wrong direction. Thus, wrong assembly of the electrolytic cell can be prevented so that normal electrolysis can be performed. 
     In addition, since determination of the direction of the electrode plate  3  is easily performed, the assembly of the bipolar-electrode electrolytic cell  1  can be performed simply and efficiently. 
     In addition, in the first embodiment, the latching portion  26  and the latched portion  27  are provided, and the fitting convex portion  36  and the fitting concave portion  37  are formed on the spacer  4 . Thus, the connection of the spacers  4  and  4  between each other can be performed simply, and the connection state can be made firm. 
     Modification Example 
     In addition, in the first embodiment, the cut-out portion  10 A is formed so that the shape of the peripheral portion is in substantially a U shape. However, the invention is not limited to the embodiment. For example, as illustrated in  FIGS. 9A and 9B , the shape of the peripheral portion of the cut-out portion  10 A may be formed so as to be substantially a V shape, and may be formed in other polygonal. In brief, the cut-out portion  10 A surrounds the outer periphery of the projecting part  35 , and may be open to the outside of one end periphery of the electrode plate  3 . 
     In addition, the projecting part  35  is not necessarily formed on the right end portion of the concave portion  25   a  which is positioned on the upper portion side of the concavity  25  of the spacer  4 . If the projecting part  35  is not formed on imaginary center lines L 1  to L 4  (in other words, lines bisecting the outer periphery of the concavity  25  so as to be the line symmetry) passing points p and p which bisect corner portions  25 s and  25 s of the concavity  25  or one side of the concavity  25 , the projecting part  35  may form on any position of the concavity  25 . 
     In other words, if the projecting part  35  is formed on the imaginary center lines L 1  to L 4 , the electrode plate  3  can be disposed on the concavity  25 , because the electrode plate  3  having the cut-out portion  10 A, which is fitted into the projecting part  35 , is positioned such that the projecting part  35  and the cut-out portion  10 A correspond to each other even though any one of the plate surfaces  3   a  and  3   b  is directed to the spacer  4 . On the other hand, when the projecting part  35  is formed on a position which is shifted from the imaginary center lines L 1  to L 4  and the cut-out portion  10 A of the electrode plate  3  is formed so as to surround the projecting part  35 , the forming position of the cut-out portion  10 A when the one plate surface  3   a  of the electrode plate  3  is viewed in a plan view, and the forming position of the cut-out portion  10 A when the other plate surface  3   b  is viewed in a front view, are not always aligned to each other. In other words, the one plate surface  3   a  of the electrode plate  3  can be always disposed in one direction on the spacer  4 . 
     Second Embodiment 
     Next, a second embodiment of the invention will be described referring to  FIGS. 10A to 10D . In the second embodiment, the same reference numeral is given to the same configuration of the first embodiment and the description thereof will be omitted. In addition, in the bipolar-electrode electrolytic cell  1  of the second embodiment, a shape of a cut-out portion  10 B of the electrode plate  3  is different from the first embodiment. Besides that, the configuration of the second embodiment is the same as the first embodiment. 
     The cut-out portion  10 B of the second embodiment is formed such that an angle portion  3 s of the electrode plate  3  corresponding to the projecting part  35  of the spacer  4  is cut in a straight shape when the one plate surface  3   a  of the electrode plate  3  is viewed from a front view. Two angles θ 1  and θ 2  formed on the electrode plate  3  are formed to be different from each other by the cutting. The shapes of the electrode plates  3  are different from each other by such an electrode plate  3 , between a case where the one plate surface  3   a  of the electrode plate  3  is directed in one direction and a case where the other plate surface  3   b  of the electrode plate  3  is directed in one direction. 
     Accordingly, similar to the above first embodiment, as illustrated in  FIGS. 10A and 10B , only when the other plate surface  3   b  of the electrode plate  3  is opposite to the bottom surface y of the concavity  25 , the projecting part  35  and the cut-out portion  10 B are positioned on the portions corresponding to each other, and the electrode plate  3  can be disposed inside the concavity  25 . On the other hand, as illustrated in  FIGS. 10C and 10D , when the electrode plate  3  is assembled to the spacer  4  in a direction opposite to a predetermined direction, a portion which is fitted into the projecting part  35  of the cut-out portion  10 B is shifted from the position of the projecting part  35 , and the electrode plate  3  is fitted into the projecting part  35  and then cannot be fitted into the concavity  25 . 
     Accordingly, also in the second embodiment, similar to the above first embodiment, only when the other plate surface  3   b  of the electrode plate  3  is opposite to the concavity  25 , the electrode plate  3  can be disposed on the spacer  4 . Accordingly, the same functions and effects as those of the above first embodiment can be obtained. 
     Third Embodiment 
     Next, a third embodiment of the invention will be described referring to  FIGS. 11A to 11D . In the third embodiment, the same reference numeral is given to the same configuration of the first embodiment and the description thereof will be omitted. In addition, in the bipolar-electrode electrolytic cell  1  of the third embodiment, the configuration thereof is different from the first embodiment in that the engaging portion is not cut out and is a hole  40  into which the projecting part  35  is fitted. Besides that, the configuration thereof is similar to the first embodiment. 
     In the third embodiment, the hole  40  has a diameter slightly larger than the diameter of the circle column of the projecting part  35 , and the projecting part  35  can be fitted into the hole  40 . 
     As illustrated in  FIGS. 11A and 11B , in the third embodiment, the projecting part  35  is formed so as not to position on the imaginary center lines L 1  to L 4 . Furthermore, when the other plate surface  3   b  is disposed opposite to the bottom surface y of the concavity  25  of the spacer  4 , the hole  40  of the electrode plate  3  is formed on a position into which the projecting part  35  is fitted. Accordingly, in the case described above, the projecting part  35  is fitted into the hole  40 , and the electrode plate  3  can be disposed on the concavity  25 . However, as illustrated in  FIGS. 11C and 11D , when the one plate surface  3   a  is disposed to be opposite to the bottom surface y of the concavity  25 , since the position on which the hole  40  is formed is shifted from the position of the projecting part  35 , the electrode plate  3  is prevented from fitting into the concavity  25 . Accordingly, also in the third embodiment, similar to the first and second embodiments, only when the other plate surface  3   b  of the electrode plate  3  is opposite to the concavity  25 , the electrode plate  3  can be disposed on the spacer  4 . Thus, the same effects as that of the first embodiment can be obtained. 
     In addition, in the first embodiment, the modification examples thereof and the second embodiment, the engaged portion is the projecting part  35  and any of the electrode plate  3  having the cut-out portion  1  OA or the electrode plate  3  having the cut-out portion  10 B can be applied to the spacer  4  including the projecting part  35 . However, as illustrated in  FIGS. 12A and 12B , and  FIGS. 13A and 13B , for example, the latched portion may be a projecting wall  50  or  51  fitted into the cut-out portion  10 A or  10 B, instead of the projecting part  35 . Even in a case when the engaged portion is the projecting wall  50  or  51 , only when the electrode plate  3  is directed in one direction, the electrode plate  3  can be disposed on the concavity  25 . Thus, the same functions and effects as those of the above first and second embodiments can be obtained. 
     INDUSTRIAL APPLICABILITY 
     According to the bipolar-electrode electrolytic cell of the invention, corrosion of the electrode plate can be avoid due to an wrong disposition of the electrode plate, and decrease of the electrolysis efficiency of the bipolar-electrode electrolytic cell in the early stage can be avoid. In addition, peeling of the coating of the electrode plate can be avoided, and the short life of the electrode plate is prevented. 
     In addition, according to the bipolar-electrode electrolytic cell of the invention, the electrolysis efficiency of the bipolar-electrode electrolytic cell can be maintained for a long period. 
     In addition, according to the bipolar-electrode electrolytic cell of the invention, since the direction of the electrode plate can be easily determined, the assembly of the bipolar-electrode electrolytic cell can be performed simply and efficiently. 
     REFERENCE SIGNS LIST 
     
         
         
           
               1  bipolar-electrode electrolytic cell 
               2  chassis 
               3  electrode plate 
               3   a  one plate surface 
               3   b  other plate surface 
               4  spacer 
               10 A,  10 B cut-out portion (engaging portion) 
               25  concavity 
               26  latching portion 
               27  latched portion 
               35  projecting part (engaged portion) 
               36  fitting convex portion 
               37  fitting concave portion 
               40  hole (engaging portion) 
               50 ,  51  projecting wall (engaged portion) 
             C unit cell