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United States 'Patent l1113,616,442

- Inventors Wayne S. Cheng; Peter R- Johnston, both of Neenah, Wis. [56] References Cited Appl. No. 884,28 1 1 UNITED STATES PATENTS Filed Dec. 11, 1969 2,273,798 2/1942 Heise et a1...... 204/82 Patented Oct. 26, 1971 3,462,351 9/1969 Grangaavd 204/83 Assignee Kimerberly-Clark Corporation 3,506,560 4/1970 Grangaavd 204/263 Neenah, Wis. 3,507,769 4/ 1970 Grangaavd ...... 204/265 Primary Examiner—F. C. Edmundson Atrorneys- Daniel J. Hanlon, Jr. and Raymond J. Miller

[54] ELECTROCHEMICAL HAVING GAS ABSTRACT: An electrochemical device particularly includ DIFFUSION ing an electrolytic cell adapted for peroxide production. The 8 Claims, 6 Drawing Figs. device has a unitized insert electrode structure for mounting [52] in an outer retaining casing. The unitized insert [1.5. CI ...... 204/257, electrode structure is adapted to provide a dual cell arrange 204/83, 204/263, 204/265 [51] ment including planar each of which has a separate Int. Cl...... 301k 3/00, cooperating and semipermeable diaphragm. The flow C0lb 15/00 [50] path of electrolyte in each cell is into an anode chamber, Fleld at Search ...... 204/257, through the semipermeable diaphragm to the 258, 263, 265 chamber over the cathode surface and out of the cell. PATENTEUncrzsusn 3,616,442 SHEEI 1 BF 4

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FIG. 3,616,442 1 2 HAVING GAS DIFFUSION semipermeable 10 form one cell of the. unitized in: ELECTRODE sert electrode structure, the electrode structure being; ar BACKGROUND OF THE INVENTION ranged for convenient mounting within the casing. 2. Referringagain to FIG. 2, it will be noted that longitudinally 1. Field of the Invention extending sidewalls 3 are provided with vertically. extending, This invention‘ relates to electrochemical devices adapted ribs 12 which engage the insert’ electrode structure andpro: for peroxide production. More speci?cally, this invention re vide spacings between the ribs for electrolyte flow‘along the lates to an arrangement of components of‘an electrolyte cell semipermeable diaphragm and anodeface. The insert elec or cells in a unitized ‘structure adapted for insertion in a- casing trode structure at the comers is spaced also by corner protru capable of retaining electrolyte. Still more speci?cally, the in sions l3, and the insert electrode structure mounts on a, vention relates to an electrolyte cell. structure for peroxide horizontally extending. ledge means 14 of the casing portion. production in which electrolyte ?ow is substantially As, shown most ‘clearly in FIG. 2, each casing portion is also unidirectional. ‘ provided with a lower semicircular aperture designated at 15 2. The Prior- Art with Relation to the Invention and, in the assembled condition, such semicircular portions The construction of electrochemical devices in thenature form the inlet for electrolyte. To provide for convenient flow of electrolytic cells tends to be complicated due toa number of electrolyte to the interior of the casing and between the ribs. of factors. Such include the necessity for provision offvarious 12, the. frames 6 are cut out at 16, theelectrolyte?ow path afé inlets and outlets governing electrolyte movement, and ar forded by this arrangement being clearly shown in FIG. 6. rangements for electrode replacements. Additionally, in‘ cells The‘frames 6 have cut out window areas 17 whichextend for peroxide production provision must be made for the in vertically with spacer bars 18, border an internal-peripheral troduction to the cells of oxygen-containing gasesand for ex seat,‘ are‘ closed‘by the air porous cathode, and permit the. pulsion of exhaust gases. These requirements,plus considera passageof'electrolyte to the cathode seated‘in the, frames. The tions of adequate electrical connections to the , not rims 19. of the frames communicate with longitudinnlly ex," only tend to complicate the structure but make the upkeep; tending ledges 20 and the opposed'ledges 20,0f-the two frames relatively costly since electrode life is usually distinctly as well as the rims are sealedtogether in the assembled condif limited. tion of the frames. We have found that a unitized electrode structuremay be As shown most clearly in FIG. 4‘, thebars 16 may include‘ conveniently provided for insertion in a casing adapted for slots 21 which extend through the barsand communieatead electrolyte retention, and that such insert maybe quickly and: 30. jacent ?uid flow channels to inhibit against’ deadv spots‘. in they easily replaced when the electrodes have approached‘the end ?ow. Such‘ slots 21 are not necessary but aidoperation. Each of their useful life. We have also found‘ that such insert elec frame 6 carries at its upper extremity a protuberance 22 and trode structure may, in a preferred embodiment of. the inven tion, include a' pair of planar cathodes which de?ne between each protuberance is cut out in substantially a. semicircle, to provide for the receipt of an inlet pipe 24. in the- assembled them an air chamber for the supply of oxygen to the cells. 35 Also in the operation of the electrochemical device of this condition (FIG. 4) of the two frames 6. Additionally, bosses invention electrolyte ?ow in a cell inthe production of perox 25; on each ofthe two frames are provided to serve as precise ide is unidirectional and from the anode through a semiperme spacer components in the ?tting together of the frames 6. As able diaphragm over the cathode face to an outlet. most clearly shown in FIG. 3, the two frame portions 6 together constitute a framework which is retained. as a unitary 40. BRIEF DESCRIPTION OF THE DRAWINGS structure by a vertically extending line of adhesive 27. AdheL sive 27 joins the frames 6 along the vertically extending rims FIG. 1 is a diagrammatic view illustrating electrolyte flow l9of the two frames. ‘I ‘ paths in an electrochemical device in general accordance with The cathodes 7 are held in position on the frames 6 by the invention; suitably water resistant adhesive 28. Additionally, the com FIG. 2 is a fragmentary view illustrating the. arrangement of 45 posite of the plastic screen, the anode and the semipermeable component parts for an electrochemical device in accordance diaphragm are retained on each frame 6 by a vertically ex with the invention; tending strip of adhesive 30. FIG. 3 is an enlarged elevational view partially in section il The casing 2 in its end wall 4 and at the upper area of such lustrating a unitized insert electrode structure; and end wall is provided with an opening de?ned by the semicircu FIGS. 4-6 inclusive are fragmentary views illustrating struc tural arrangements useful in devices such as those illustrated lar cutouts 31 (FIG. 2). In the assembled condition the cutouts in FIG. 1. 31 cooperate to provide the outlet opening of the device. Referring now to FIG. I, the parts therein which generally PREFERRED EMBODIMENTS OF THE INVENTION correspond to those of the speci?c structural arrangement of 55 FIGS. 2-6 inclusive have been assigned the same numeral but Referring first to FIGS. 2-4 inclusive, the numeral 1 in FIG. primed. Additionally, solid arrows indicate the general nature 2 generally designates the electrochemical device which, in of the electrolyte flow path while dashed lines, including this instance, has a pair of electrochemical cells. The device 1 headed arrows, indicate inlet oxygen (air) flow. More specifi includes a casing generally indicated by the numeral 2 and cally, the electrolyte enters at l5‘, passes upwardly through having complementary parts which include rectangular lon 60 the anode indicated by the plus sign. The semipermeable gitudinally extending walls 3 and opposed end walls 4. The nu diaphragm and the plastic mesh contact on exposed isurfece of meral 5 (FIG. 3) generally designates the unitized insert elec the cathode 7'. Air is introduced through the pipe 24' to the trode structure which is mounted within the casing. Insert air chamber between the two cathodes 7', and the air passes electrode structure 5 is comprised of a pair of frames 6 (FIG. through the cathodes to contact the flowing electrolyte. 2) each of which is adapted to seat and retain one platelike 65 In a further modi?cation of the invention as illustrated in rectangular gas diffusion cathode 7. Suitably, such cathode is FIG. 5, dual inlet pipes 24' may be provided. Such dual pipes of porous carbon composition. Also, each frame 6 on the side serve the same purpose as the single pipe but provide for the of the frame remote from the cathode supports nickel wire establishment of electrolyte in the device assembled. mesh electrolyte permeable anode 8. Additionally, each frame In ‘the drawing (FIG. I) the inlet pipe 24' and the cathodes 6 between the anode and the cathode on the side of the frame 70 have been indicated to be negatively charged while both remote from the cathode is provided with a plastic, liquid have been indicated to be positively charged, This, permeable supporting mesh 9. A semipermeable membrane designation has been used as a matter of convenience to avoid 10 is in contact with the anode and supported between the complication of the drawings with unnecessary wiring. anode and the plastic mesh 9. As may be more clearly seen The oxygen in known manner reacts with water of the in from FIG. 3, each cathode 7 and a cooperating anode 8 and 75 . ?owing alkaline electrolyte and, under the in?uence of electri 3,616,442 3 4 cal energy supplied to the cathode, reacts to provide hydroxyl and perhydroxyl . The electrolyte commonly for this pur the casing has a lower inlet opening for the passage of liquid pose has a pH of at least 10, and a peroxide content of up to electrolyte to said anode, said permeable diaphragm and about 10 grams per liter of flowing can be obtained at across a face of said gas diffusion cathode, and said unitized relatively low power costs. The perhydroxyl is contained insert electrode structure has an air inlet to said air chamber within the outflowing electrolyte stream at 31'. It is to be for continuous flow of air to said gas diffusion cathode, said noted that, in the description of the speci?c structural ar casing being open upwardly for movement of liquid and gas rangement as well as in the FIG. 1 description concerned outwardly of said device. primarily with electrolyte flow, the air chamber between the 3. An electrochemical device according to claim 2 in which the unitized insert electrode structure has a pair of planar planar carbon electrodes is maintained substantially free of 10 electrolyte even though the electrolyte level be that indicated cathodes and the framework has a pair of frames, one support by the “A." Thus, in effect, the cathodes seal the windows of ing each cathode on opposite sides of the said air chamber, the frames which mount the electrode structures and each said frame also supporting on an outer side thereof an cooperate to provide a single framework adapted as the insert anode for cooperation with an adjacent cathode, and a for the electrolytic device. semipermeable diaphragm between each cathode-anode ar 15 As many apparently widely di?’erent embodiments of this rangement and supported on the outer side of a said frame. invention may be made without departing from the spirit and 4. An electrochemical device according to claim 1 in which scope thereof, it is to be understood that I do not limit myself . the framework of the unitized insert electrode structure in to the speci?c embodiments thereof except as de?ned in the cludes a frame having an internal seat and the cathode is appended claims. planar and received ?xedly on said seat. We claim: 20 5. An electrochemical device according to claim 1 in which 1. An electrochemical device including an electrolytic cell the device includes a pair of electrolytic cells each having a comprising an electrically nonconductive casing having a planar cathode, an anode and a semipermeable membrane, spacing for retention of electrolyte; a unitized insert electrode and the framework includes a pair of similar frames, each of said frames retaining the components of a cell and the frames structure within said spacing and including: a framework 25 de?ning an air chamber which is communicable with said being‘ united to de?ne the air chamber between the cells. electrolyte spacing through an opening of the framework, a 6. An electrochemical device according to claim 5 in which gas diffusion cathode supported by said framework closing the the air chamber has a pair of air inlets. said opening and adapted to inhibit liquid flow to said air 7. An electrochemical device according to claim 1 in which chamber from said spacing, an anode supported by said 30 the casing has vertically extending ribs de?ning vertically ex framework and fronting on said electrolyte spacing, a tending channels for electrolyte flow and unitized insert elec semipermeable diaphragm also supported by said framework trode structure abuts said ribs, and said ribs have cutouts com between said anode and cathode; and said unitized insert elec municating adjacent vertically extending channels. trode structure resting within the electrolyte spacing in close 8. An electrochemical device according to claim I in which engagement with the said casing and being separable 35 the casing has a lower inlet opening for electrolyte passage therefrom as a unit. and the framework is cutout adjacent said passage to accom 2. An electrochemical device according to claim 1 in which modate said electrolyte I.flottr arpun‘d the framework.

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