Document qm0XOExd9zzgY2VyNQdnyo8zK

FILE NAME: Olin (OLIN) DATE: 1980 Oct 21 DOC#: OLINOOl DOCUMENT DESCRIPTION: US Patent 4229722 - Glove-Like Diaphragm Structure for Electrolytic Cells [It is desirable to be able to convert these cells from asbestos diaphragms to synthetic diaphragms or membranes to reduce the health hazard from asbestos, and to protect the environment from asbestos contamination. One solution would be the replacement of existing diaphragm cells with new filter-press type synthetic diaphragm or membrane cells. This alternative is not economically viable for most manufacturing situations. The other alternative is to somehow modify existing diaphragm cells so that they will be able to use synthetic diaphragms or membranes.] United States Patent [19] Specht [il] 4,229,277 [45] Oct. 21, 1980 [54] GLOVE-LIKE DIAPHRAGM STRUCTURE FOR ELECTROLYTIC CELLS [75] Inventor: Steven J. Specht, Mentor, Ohio [73] Assignee: Olin Corporation, New Haven, Conn. [21] Appl. No.: 71,204 [22] Filed: Aug. 30, 1979 [51] Int. Cl.3 ...................... C25B 13/02; C25B 13/08 [52] U.S. Cl...................................... 204/252; 204/282; 204/296 [58] Field of Search............................... 204/252-258, 204/263-266, 295-296, 282-283 [56] References Cited U.S. PATENT DOCUMENTS 2,104,812 4,078,987 4,110,191 1/1938 3/1978 8/1978 P h illip s................................... 204/283 Specht ............................... 204/252 X Specht et al........................ 204/295 X 4,152,225 4,165,272 4,175,024 5/1979 W oodward, Jr. et al......... 204/252 X 8/1979 Cunningham ..................... 204/252 X 11/1979 Darlington ......................... 204/295 X Primary Examiner--Howard S. Williams Assistant Examiner--D. R. Valentine Attorney, Agent, or Firm--Bruce E. Burdick; Thomas P. O'Day [57] ABSTRACT A non-adherent glove-like diaphragm structure for use in an electrolysis cell. The diaphragm structure has a finger means with an open upper end, and closed lower end, and a middle section connecting the upper and lower end. The lower end is perforated so as to receive an anode riser therethrough. The diaphragm structure also includes a border for attaching the finger to the upper edge of the cathode so as to separate the cathode from the anode and the anolyte of the electrolytic cell. 20 Claims, 7 Drawing Figures 'SB Z4 U .S. Patent Oct. 21, 1980 Sheet 1 of 3 4,229,277 U .S. Patent Oct. 2 1 , 1980 Sheet 2 of 3 4,229,277 .F IG -3 U.S. Patent Oct. 21,1980 Sheet 3of 3 4;229,277 - T its -7 2 4,229,277 1 said finger means having portions defining at least GLOVE-LIKE DIAPHRAGM STRUCTURE FOR one opening in the lower end thereof through ELECTROLYTIC CELLS which said anode risers can sealingly pass; and (b) border means, sealingly attached to said upper end This invention relates to synthetic diaphragm struc 5 of said finger means, for passing between said cell tures for electrolytic cells and particularly to a non top and said upper edge of said cathode structure adherent, glove-like diaphragm structure for such cells. so as to separate said upper edge of said cathode Concern about the health hazards of asbestos dia from said anode and said anolyte. phragms has resulted in the development of synthetic The invention also provides a method of assembling a substitutes which can be used in diaphragm-type elec 10 diaphragm electrolysis cell of the type having a cell trolytic cells. This development has resulted in the base, a cell top, a grate-like cathode structure having a availability of several commercially produced, ion ex plurality of vertical cathode fingers, a plurality of verti change, diaphragm materials which are manufactured cal anodes rising through said cathode structure, a plu in the form of flat sheets. All new commercial installa rality of flanged anodes posts connecting said anodes to tions using such synthetic diaphragms or membranes 15 said cell base, said anodes posts passing into holes in said incorporate filter-press cells because of the simplicity of base and a diaphragm between said cathode structure installing the separator. and said anodes, which method comprises the steps of: There are, however, large numbers of electrolytic (a) fabricating a non-adherent diaphragm structure cells presently in operation using asbestos diaphragms, having holes therein for said anode posts; such as, for example, the Hooker H-4 cell disclosed in 20 (b) placing an insulating seal on said cell base; U.S. Pat. No. 3,904,504, by Ruthel et al., issued Sept. 9, (c) placing said grate-like cathode structure on said 1975, to Hooker Chemicals and Plastics Corporation. It seal and insulatingly fastening said cell base to said is desirable to be able to convert these cells from asbes cathode structure; tos diaphragms to synthetic diaphragms or membranes (d) loosely inserting a non-adherent diaphragm struc to reduce the health hazard from asbestos, and to pro 25 ture into openings in said grate-like cathode struc tect the environment from asbestos contamination. One ture; solution would be the replacement of existing dia (e) aligning the holes in the diaphragm structure with phragm cells with new filter-press type synthetic dia the holes in the cell base; phragm or membrane cells. This alternative is not eco (f) placing said anodes between said vertical cathode nomically viable for most manufacturing situations. The 30 fingers; other alternative is to somehow modify existing dia (g) inserting said anode posts through the aligned phragm cells so that they will be able to use synthetic holes of said diaphragm and into said holes of said diaphragms or membranes. cell base, One proposed method of converting a diaphragm (h) tightening said anode posts to simultaneously electrolytic cell to a membrane electrolytic cell is that 35 secure said anodes and press said flange against the of U.S. Pat. No. 4,112,149, by Babinsky, issued Sept. 5, portions of said diaphragm structure surrounding 1978, to Diamond Shamrock Corporation. The Ba said holes of said diaphragm structure against said binsky patent suggests forming a membrane on a stan cell base, dard diaphragm cell cathode by suspending a matting (i) placing a sealing means between said cathode material in a liquid medium and then vacuum-depositing 40 structure and cell top; the matting material over the surface of the cathode and (j) folding portions of said diaphragm structure into then coating the vacuum-deposited matting material said sealing means; and with a layer of thermoplastic cation exchange material. (k) comprising a border portion of said diaphragm The thermoplastic material is then fused into a thin and structure between said cell top and said cathode uniform film on the surface of the matting material by 45 structure so as to complete the separation of said baking the cathode in an oven. The baked thermoplastic cathode structure from said anodes and cell base. layer can be hydrolyzed if necessary to change the The objects and advantages of the present invention thermoplastic form into a cation exchange form. How will be better understood by reference to the attached ever, that method utilizes asbestos fibers as the matting drawing, in which: material, and thus suffers from the very environmental 50 FIG. 1 is a side elevational view of a typical dia drawbacks which conventional asbestos diaphragm phragm cell in which the invention can be used; exhibit. FIG. 2 is a vertical, cross-sectional view, taken along These problems are solved by the present invention, lines 2--2 of FIG. 1 along the center line of an anode which provides a non-adherent, glove-like diaphragm thereof, showing the diaphragm structure of the inven structure for use in an electrolysis cell of the type hav 55 tion; ing an anolyte, a catholyte, a grate-like cathode struc FIG. 3 is a plan view of the diaphragm structure of ture with an upper edge, a cell base supporting said the invention in place on the cathode of the cell of FIG. cathode structure, at least one anode riser attached to l ; said cell base, at least one anode attached to said anode FIG. 4 is a vertical, cross-sectional view taken along risers and passing upwardly through said cathode struc 60 lines 4--4 of FIG. 3 showing the placement of the dia ture and a cell top for closing the top of the cell, said phragm structure of the invention in an otherwise con diaphragm structure comprising the following parts: ventional electrolytic cell; (a) at least one finger means, having an open upper FIG. 5 is an isometric view of the diaphragm struc end, a closed lower end and a middle section con ture of the invention, showing the folded tabs and anode necting said upper and lower ends, for passing 65 riser openings which can be provided therein, downwardly through said grate-like cathode struc FIG. 6 is an isometric view of a folded diaphragm ture and loosely around and under said anode so as sheet immediately prior to being sealed together to form to separate said anode from said cathode structure, a diaphragm structure of the invention; and 4,229,277 FIG. 7 is a front elevational view of the diaphragm ture 12 a suitable diaphragm material and then baking sheet of FIG. 6 after sealing showing where the seals the diaphragm in order to dry the diaphragm material are made. onto the cathode structure 12. The obvious solution to FIG. 1 is an external, side, elevational view of a con the need for a means of converting from a diaphragm ventional electrolytic, chlor-alkali cell 10 in which the material to a cation exchange membrane material would invention may be utilized. Cell 10 comprises a grate-like be to make a slurry of cation exchange material and cathode structure 12 supported on a cell base 14 and bake that material onto the conventional diaphragm. covered by a cell top 16. Cell base 14 can be in turn However, cation exchange materials are not presently supported by a double pedestal-type support 18, which commercially available in a form suitable for generation in turn rests on the floor of a typical chloralkali plant. A 10 of slurrys for the cation exchange sheet materials which suitable gasket means 20 is provided between cell top 16 are available must be modified so as to fit cathode struc and cathode structure 12. Similarly, a suitable gasket 22 ture 12. is placed between cathode structure 12 and cell base 14. The vertical cross-sectional view of FIG. 4 illustrates Also lying between cathode structure 12 and cell base how this dilemma can be solved by use of the present 14 is an anode busbar structure 24 which serves to con 15 invention. First, a diaphragm structure such as later duct current to the anodes 32 (see FIG. 4) of cell 10. described in FIG. 5 is fabricated as described below and Gasket 22 would therefore preferably lie between bus then installed in cell 10. Specifically, once the glove-like bar 24 and cathode structure 12 so as to insulate them structure has been fabricated, a rubber liner or gasket 22 from each other. Cathode structure 12 is preferably is placed on busbar 24, which in turn rests on cell base provided with cathode busbars 26, 28, and 30 which can 20 14. Cathode structure 12 is then placed on the cell base be specially designed so as to more uniformly distribute and diaphragm structure 34 is installed over the flow current within cathode structure 12. From all external channel 40 and transverse fingers 42 of cathode struc appearances, the structure of cell 10 appears to be con ture 12 with perforations 46 aligned with holes 48 in ventional, and therefore FIG. 1 is labeled "prior art" busbar 24. Anodes 32 are then placed between adjacent even though it is unconventional inside. 25 cathode fingers 42 and between cathode fingers 42 and In order to show the diaphragm structure of the in flow channel 40. Anode posts 50 of anodes 32 are in vention as it appears within cell 10, reference should be serted through perforations 46 and holes 48. A gasket 52 made to FIG. 2, which is a cross-sectional view taken and a gasket 54 can be provided above and below perfo longitudinally along the vertical center line of an anode ration 46 and anode post 50 has a flange 56 which is 32 of cell 10. The reference numerals in each of the 30 adapted to compress gaskets 52 and 54 sealingly about FIGURES of the drawing are intended to refer to the perforations 46 upon the tightening of anode post 50 same structures unless otherwise indicated. The interior within busbar 24. This tightening is accomplished by of cathode structure 12 is surrounded by the diaphragm use of some suitable tightening means such as threaded structure 34 of the invention. Diaphragm structure 34, nuts 58. After anode post 50 has been tightened so as to which as best seen in FIG. 5, as described below. 35 seal perforation 46, a gasket 60 is placed over the top Referring again to FIG. 2, diaphragm structure 34 flange of cathode structure 12 and tabs 66 of diaphragm includes a finger means 36 and a border means 38. Fin structure 34 are folded over gasket 60. Another gasket ger means 36 surrounds anodes 32 while border means 64, which can be identical to gasket 60, is placed over 38 is for passing between cell top 16 and cathode struc the folded tab 66 and cell top 16 is placed atop cathode ture 12 so as to separate the cathode structure 12 from 40 structure 12 and secured with springs not shown to anode 32 and the anolyte (not shown) in contact with compress gaskets 60 and 64 against tab 66 so as to seal anodes 32. The configuration of cathode structure 12 is the diaphragm at cathode flange 62. shown in some detail in FIG. 2. The basic element of FIG. 5 shows an isometric view of diaphragm struc structure 12 is the hollow, trapezoidal peripheral flow ture 34, which is rotated 90 from its normal position in channel 40, which is best seen in FIG. 4, and cathode 45 order to better show the lower ends 82 of finger means fingers 42, which are best seen in FIGS. 3 and 4. Chan 36. Structure 34 is seen to be a glove-like structure with nel 40 serves to direct caustic product to a caustic outlet a border means 38 from which a plurality of finger (not shown) and hydrogen gas to a hydrogen gas outlet means 36 downwardly extend, the finger means down 43, best seen in FIG. 3. wardly terminating at a closed lower end 82 which is FIG. 3 is a plan view showing for purposes of illustra- 50 perforated with a number of perforations 46. The num tion both a conventional adherent-type diaphragm 44 at the lower left of FIG. 3 and the diaphragm structure 34 ber of perforations 46 per finger means 36 is determined by the number of anode posts 50 per anode 32. The of the present invention at the lower right of FIG. 3. In actual practice of the invention diaphragm 44 is com perforations 46 are preferably made in a diaphragm sheet prior to the folding and sealing operations of pletely replaced by structure 34. Cathode structure 12 is 55 FIGS. 6 and 7. grate-like, comprising peripheral flow channel 40 and The fabrication of diaphragm structure 34 is best transverse, parallel, spaced cathode fingers 42. In order understood by reference to FIGS. 6 and 7 which show, for diaphragm structure 34 to fit into and surround respectively, the folding and sealing of tab portion 66a, cathode fingers 42, it is necessary that diaphragm struc 66b and edge portion 68a and 686 of a finger means 36 ture 34 have a rather complex shape. The ability to 60 of diaphragm structure 34. After perforation to provide manufacture such a complex shape is now available perforations 46, a long sheet of cation material is dou with the discovery, not forming a part of this invention, bled back and forth into a plurality of folds which are of that the cation exchange form of the cation exchange sufficient length to fit over transverse cathode fingers materials can be successfully heat sealed without de 42 and below anodes 32. The bottom portion of each stroying the ion exchange properties of the membrane. 65 fold is then trimmed so that a folded sheet now has a Prior art adherent diaphragm 44 was customarily ap T-shaped configuration such as seen in FIG. 6. Then plied by vacuum depositing a slurry upon the flow edges 68 are sealed to edges 686, tab portion 66a is channel 40 and transverse fingers 42 of cathode struc sealed to tab portion 666, tab portions 70a to tab por- 4,229,277 tions 706, and edge portion 72a to edge portion 726 to they be overlapped at lower end 82 in order to have form sealed edges 66, 68, 70, and 72 as seen in FIGS. 5 double strength at perforations 46. Another alternative and 6. Alternatively, seals 74, 76, 78, and 80 in portion would be to reinforce lower end 82 by an additional 66, side 68, side 72, and tab portion 70, respectively, can separate piece of cation exchange material so as to be made prior to trimming diaphragm structure 34 into strengthen perforations 46. The bottom end 82 and the T-shaped configuration of FIG. 7. middle section of each finger means 36 comprises a In operating cell 10, it may be desirable to utilize a single U-shaped sheet looped under the bottom edge of spacer between anode 32 and diaphragm structure 34 in an anode 32 and to linear side flanges or seals 76, 78 order to prevent abrasion of either the surface of dia joining the sides 68, 72 of the folded sheet. Gasket phragm structure 34 or the surface of anode 32. The 10 means 20 can preferably comprise the subelements of a surface of anode 32 generally is comprised of a catalytic part of border means 38 lying between cell top 16 and coating which is susceptible to abrasion by diaphragm flange 62 of cathode structure 12, a gasket 64 which structure 34. Such a spacer could be formed in the same seals between the cell top 16 and border means 38, a shape as diaphragm structure 34 and be placed immedi gasket 64 which seals between border means 38 and ately above the corresponding parts of diaphragm struc 15 flange 62 and a transition region of synthetic diaphragm ture 34. For purposes of showing this type of spacer, material for connecting finger means 36 to border reference is made to FIGS. 2, 3, and 4 of U.S. Pat. No. means 38 so as to complete the separation of cathode 4,115,237, by Woodard Jr. et al. commonly assigned. structure 12 from anodes 32 and any surrounding ano Referring again to FIG. 4, it is seen that diaphragm lyte within cell 10. structure 34 is a non-adherent, glove-like structure for 20 As best seen in FIGS. 5 and 7, diaphragm structure 34 use in electrolysis cell 10. Cell 10 would have an anolyte preferably has at least two comers formed by the junc solution surrounding anodes 32 within finger means 36. tion of tab portion 66 and 70, respectively, with sides 68 Cell 10 would also have a catholyte solution lying under and 72. Tab portions 66 and 70 are twistable and thus diaphragm structure 34 and within and surrounding serve as the transition regions, previously mentioned, cathode structure 12 and particularly cathode fingers 25 between finger means 36 and border means 38 at the 42. It is noted that cathode structure 12 is a grate-like junction of tabs 66 and 70 with sides 68 and 72. Tab cathode structure with an upper edge defined by the top portion 66 and 70 adapted to be held in sealed, twisted surface of flange 62. Also, it is noted that electrolysis position against border means 38 and between cell top cell 10 is a vertical electrolytic cell with cathode fingers 16 and flange 62 of cathode structure 12. 42 and anodes 32 aligned in parallel. The anodes 32 pass 30 Seals 68 and 72 are preferably two vertical, linear side upwardly through cathode structure 12 from the point seals along opposite sides 68 and 72 of finger means 36. of their attachment to anode busbar 24 of cell base 14. Seals 74 and 80 are preferably lateral linear seals at an Diaphragm structure 34 includes the finger means 36 angle to seal 76 and 78. Seals 74 and 80 are adapted to be for surrounding the anode and the border means 38 for twisted into a twisted position lying partially against sealing about the cathode structure. Finger means 36 35 border means 38. It is preferred that seals 74,76, 78, and further includes an open upper end 86, a closed lower 80 be heat sealed. end 82, and a middle section 84 connecting upper end 86 The anode is preferably an insoluble electrode such as with lower end 82. In this manner, finger means 36 platinum group metal, titanium coated with a platinum passes downwardly through the grate-like cathode group metal, or titanium coated with a platinum group structrue 12 and loosely around and under the anodes 32 40 metal oxide. The cathode is preferably made of iron, so as to separate anodes 32 from cathode structure 12, stainless steel, or nickel. The shape of the electrodes can finger means 36 having portions defining at least one be flat perforated plate, flat mesh, louvered plate, lou opening or "perforation" in lower end 82 through vered mesh or other suitable shape which exhibits satis which an anode riser or post 50 can sealingly pass. Gas factory gas release. The diaphragms are preferably cat kets 52 and 54 serve to seal openings or perforations 46 45 ion permeable membranes which have oxidation resis following such passage. Border means 38 of diaphragm tance and chlorine resistance and are comprised of a structure 34 is sealingly attached to the upper end 86 chlorine-resistant polymer type cation-exchange mem and passes between cell top 16 and the upper edge or brane. For example, a copolymer of tetrafluoroethylene upper surface of flange 62 of cathode structure 12 so as and a sulfonated perfluorovinyl ether or a copolymer of to separate the upper edge of flow channel 40 and the 50 tetrafluoroethylene and a carboxylated perfluorovinyl upper edge of flange 62 from anodes 32 and any anolyte ether and the like. The later cation-exchange mem within the cell 10. As noted above, finger means 36 can branes are preferably used. Suitable for use as such consist essentially of cation exchange membrane sheet "carboxylate membranes" are membranes produced by material, whether or not border means 38 also consists Asahi Glass Company of Japan. Another suitable "car of cation exchange membrane sheet material. It would 55 boxylate membrane" is that disclosed in U.S. Pat. No. be preferable that border means 38 also consist essen 4,151,053j by Seko et al, issued Apr. 24, 1979. Such a tially of cation exchange membrane sheet material. carboxylate membrane preferably comprises a fluoro Preferably, middle section 84 of finger means 36 is com carbon polymer which has pendent carboxylic acid prised of two planer sheets of synthetic diaphragm ma groups of the formula--OCF2COOH and derivatives terial and two linear side flanges or "sides" 68, 72 join 60 thereof. Carboxylate membranes have been found to ing the sides of the two sheets. These edges are called produce about 35% by weight caustic soda aqueous "flanges" because when joined they lie in a plane ap solution at over 90% current efficiency. proximately half way between the plane of each of the An alternative cation exchange membrane is one sheets forming finger means 36. If desired, a plurality of comprising a fluorocarbon polymer characterized by sheets could be used rather than one single sheet folded 65 the presence of pendent sulfonic acid groups of the back and forth. If a plurality of sheets were used, they formula--OCF2SO3H and derivatives thereof. This could be overlapped together at either lower end 82 or "sulfonic acid" membrane has been found to produce upper end 86. It would be, however, preferable that approximately 25% caustic soda aqueous solution at 4,229,277 7 8 about 75%-80% current efficiency. If such a "sulfonic 4. The diaphragm structure of claim 1, wherein said acid" membrane is treated on the caustic side with eth middle section further comprises the subelements of: ylene diamine to a depth of about 1.5 mils (38 microns) (a) Two planar sheets of synthetic diaphragm mate the current efficiency is boosted to about 85%. There rial; and fore, it is apparent that the carboxylate membrane is 5 (b) Two linear sealed side flanges joined the sides of presently superior to the sulfonic acid type membrane said two sheets. for chloralkali cells. 5. The diaphragm structure of claim 4 wherein said It will be understood that gasket 22 also serves to lower end comprises overlapped sealed bottoms of said electrically insulate busbar 24 from cathode structure two sheets. 12. Gasket 22 may take the form of a rubber sheet which10 6. The diaphragm structure of claim 1, wherein said covers the entire upper surface of busbar 24 and has bottom and middle section further comprise the subele perforations therethrough lined up with holes 48 in ments of: busbar 24. If gasket 22 is in such a sheet-like form, gas (a) a single U-shaped sheet looped under said bottom kets 54 could be eliminated and the diaphragm instead seals directly against the upper surface of gasket 22 15 of said anode; (b) two linear sealed side flanges joining the sides of surrounding holes 48. Such a procedure would elimi said sheets. nate the need to align gaskets 54 with holes 48 prior to 7. The diaphragm structure of claim 1 wherein said placing the anodes 32 between the vertical cathode border means comprises the subelements of: fingers 42 and inserting the anode posts through the aligned holes perforation 46 and holes 48. It will also be 20 sealing section, means, for lying between said cell top and said cathode structure; understood that it is preferable that the upper surface of first gasket means for sealing between said cell top flange 62 be planer so that the border means 38 of dia and said border section and said cell top; phragm structure 34 can be sealed to cathode structure second gasket means for sealing between said border 12 along a planer surface. Another alternative is that perforations 46 can be reinforced by use of inert mate 25 section and said cathode structure; and transition region means of synthetic diaphragm mate rial rather than cation exchange material since lower rial, for connecting said finger means and said bor end 82 does not have to have ion exchange properties der section means so as to complete the separation and therefore does not have to be permeable to cations of said cathode from said anolyte and anode. as does middle section 84. 30 8. The diaphragm structure of claim 7 wherein said From the above description, together with the vari upper end of said finger means has at least two corners, ous alternatives mentioned, it will be apparent that and said transition region means comprises at least two many alternatives are included within the scope of the twistable tab means, at the junction of said two corners invention and the following claims are to be interpreted with said border means, for being held in sealed, twisted broadly to include all such equivalence. What is claimed is: 35 position against said sealing section and between said cell top and cathode structure. 1. A non-adherent, glove-like diaphragm structure 9. The diaphragm structure of claim 8 wherein: for use in an electrolysis cell of the type having an (a) said finger means includes two planar sheets anolyte, a catholyte, a grate-like cathode structure with joined by two vertical, linear side seals along oppo a plurality of vertical openings and an upper edge, a cell 40 base supporting said cathode structure from below, a site sides thereof; and (b) each of said transition regions includes a lateral plurality of vertical anode risers attached to said cell linear seal means, at an angle to one of said side base, a plurality of anodes attached to said anode risers seals, for being twisted into a twisted position lying and passing upwardly into openings in said cathode partially against said sealing section. structure and a cell top for closing the top of the cell, 45 10. The diaphragm structure of claims 4, 6, or 7 said diaphragm structure comprising the following wherein said seals are heat seals. parts: 11. The diaphragm structure of claim 1 wherein said (a) a plurality of interconnected finger means, having diaphragm finger means is a cation exchange membrane an open upper end, a closed lower end and a middle and is comprised of a cation exchange resin material section connecting said upper and lower ends, for 50 having carboxylic acid moieties as the predominant ion passing over and downwardly through said grate exchange group. like cathode structure and loosely around and 12. The diaphragm structure of claim 1 wherein said under said anodes so as to separate said anodes diaphragm is a cation exchange membrane comprised of from said cathode structure, said finger means hav a cation exchange resin material having sulfonamide ing portions defining at least one opening in the 55 moieties as the ion exchange group. lower end thereof through which said anode risers 13. The diaphragm structure of claim 1 wherein said can sealingly pass; and diaphragm is a cation exchange membrane comprised of (b) border means, sealingly attached to said upper end a cation exchange resin material having sulfonic acid of said finger means, for passing between said cell moieties. top and said upper edge of said cathode structure 60 14. A method of assembling a diaphragm electrolysis so as to separate said upper edge of said cathode cell of the type having a cell base, a cell top, a grate-like from said anodes and said anolyte. cathode structure having a plurality of vertical cathode 2. The diaphragm structure of claim 1 wherein said fingers, a plurality of vertical anodes rising through said finger means consists essentially of cation exchange cathode structure, a plurality of flanged anodes posts membrane sheet material. 65 connecting said anodes to said cell base, said anode 3. The diaphragm structure of claim 2 wherein said posts passing into holes in said base, and a diaphragm border means consists essentially of cation exchange between said cathode structure and said anodes, which membrane sheet material. method comprises the steps of: 9 10 4,229,277 (a) fabricating a non-adherent diaphragm structure structure so as to complete the separation of said having holes therein for said anode posts; cathode structure from said anodes and cell base. (b) placing an insulating seal on said cell base; 15. The method of claim 14 further comprising the (c) placing said grate-like cathode structure on said step of: seal and insulatingly fastening said cell base to said 5 sealing said diaphragm structure to said cathode cathode structure; structure along a planar surface. (d) loosely inserting a non-adherent diaphragm struc 16. The method of claim 14 further comprising the ture into openings in said grate-like cathode struc step of: ture; . reinforcing the portions of said diaphragm structure (e) aligning the holes in the diaphragm structure with 10 surrounding said holes therein with additional dia the holes in the cell base; phragm material. (f) placing said anodes between said vertical cathode 17. The method of claim 14 further comprising the fingers; step of reinforcing said portions of said diaphragm (g) inserting said anode posts through the aligned structure surrounding said holes therein with inert ma holes of said diaphragm and into said holes of said 15 cell base; terial. (h) tightening said anode posts to simultaneously 18. The method of claim 14 wherein said diaphragm secure said anodes and press said flange against the is made of synthetic cation exchange membrane sheet portions of said diaphragm structure surrounding material. said holes of said diaphragm structure against said 20 19. The method of claim 18 wherein the cation ex cell base; change material is comprised of a fluorinated copo (i) placing a sealing means between said cathode lymer having as the ion exchange group a carboxyl structure and cell top; (j) folding portions of said diaphragm structure into group ending in either an acid an ester or a salt. 20. The method of claim 18 wherein the cation ex said sealing means; and 25 change material is comprised of a copolymer of a sul- (k) compressing a border portion of said diaphragm fonated perfluorovinyl ether and tetrafluoroethylene. structure between said cell top and said cathode * * * * * 30 35 40 45 50 55 60 65