CA1131170A - Diaphragm cell - Google Patents
Diaphragm cellInfo
- Publication number
- CA1131170A CA1131170A CA086,271A CA86271A CA1131170A CA 1131170 A CA1131170 A CA 1131170A CA 86271 A CA86271 A CA 86271A CA 1131170 A CA1131170 A CA 1131170A
- Authority
- CA
- Canada
- Prior art keywords
- cell
- anodes
- anode
- hollow
- backplate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
- C25B9/70—Assemblies comprising two or more cells
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
- Electrodes For Compound Or Non-Metal Manufacture (AREA)
Abstract
ABSTRACT
A novel bipolar diaphragm cell is disclosed which is constructed of a plurality of cell units. Each cell unit has a plurality of finger-like, dimensionally-stable anodes extending in one direction from a support wall and a plurality of finger-like cathodes extending in the opposite direction from the support wall.
When the cell units of the cell are assembled, the cathodes of one cell unit lie between the anodes of the adjacent cell unit to form a single cell.
A novel bipolar diaphragm cell is disclosed which is constructed of a plurality of cell units. Each cell unit has a plurality of finger-like, dimensionally-stable anodes extending in one direction from a support wall and a plurality of finger-like cathodes extending in the opposite direction from the support wall.
When the cell units of the cell are assembled, the cathodes of one cell unit lie between the anodes of the adjacent cell unit to form a single cell.
Description
1~311~0 The invention is concerned w;lth an electrolytic cell of the type which includcs a succession of ver-t;cal electrocles in which dimensionally-stable anodes alternate with cathodes carrying a diaphragm; in particular, it is concerned with the arrangement of the anodes and cathodes on a supporl wall ancl to means for securing the electrodes to the support wall.
A variety of types of electrolytic cells employing a bipolar electrode assembly and a permeable diaphragm have been known in the past. The present trend in this type of cell i~ to provide within a single cell housing a plurality of individual cell units ut;lizing bipolar electrode ~13~l17(:~
structures. In such an electrode structure, the anodes o one cell are posi-tioned in a back-to-back relationship with the cathodes of the adjacent cell and electrical contact is maintained between the two. The supporting wall for the anodes and cathodes in the back-to-back relationship functions also to physically separate the cells within the over-all cell housing.
The present invention provides an improved bipolar diaphragm cell of the described type. The present invention provides a diaphragm cell which is particularly light in weight and easy to assemble and disassemble.
The present invention furthermore provides a diaphragm cell having improved electrical connection between the cathode and anode.
Herein the term "cell unit" is used to describe the back-to-back bipolar assembly of the anodes of one cell with the cathode of the adjacent cell. Each cell thus is made up of cathodes from one cell unit interleaved and spaced from anodes of the next adjacent cell unit. The cathodes character-istically have elongated hollow portions which are interleaved or interposition-ed with and spaced from the anodes of the next adjacent cell unit. The cathodes are constructed of metal wire screening or the like perforated sheeting and are covered with a permeable diaphragm, for example, asbestos. The metal wire screening may be of any suitable metal, for example, steel or, alternat-ively, nickel or chromium or other metal sufficiently resistant to corrosion under the conditions prevailing in the catholyte during electrolysis.
The finger-like anode elements may be provided by a single sheet or wall-like element or may comprise a pair of laterally-spaced vertical walls and which are open along the outer end of the elements. The anodes are constructed of any suitable chlorine-resistant metal such as titanium having an electroconductive surface of a platinum group metal or the oxide of a platinum group metal. The term "single cell" is used to describe the cell formed by the finger-like anodes of one cell unit which are interleaved with the finger-like cathodes of the adjacent cell unit.
Another important component of the cell unit is the supporting wall or backplate. As shown in the specific embodiments hereinafter described, the backplate may serve one or more purposes including that of (1) the prime structural element for supporting the plurality of anodes and cathodes which B
11311~
make up the cell unit, (2) the principal structure which divides the entire electrolytic cell (electrolyzer) into its connponent cells and 13) the conductorby which the current flows from cell to cell. For the backplate to perform such functions it should be of appropriate construction and materials. One especially useful type of electroconductive backplate has its anodic side (or surface) of titanium and its cathodic surface of steel. These surfaces are each resistant enough to the respective cell environments to which they are exposed during cell operation to provide for long backplate life.
The present invention will be further illustrated by way of the accompanying drawings in which:
Fig. 1 shows a perspective view of the bipolar cell of the present invention with portions of the cell housing broken away.
Fig. 2 shows an enlarged portion of the electrodes taken along the line II-II in Fig. 1.
Figs. 3 - 12 illustrate alternate means for mounting the electrodes to the support wall of the present inventionO
Figs. 13-15 is another preferred embodiment of the present invention.
The bipolar diaphragm cell 10, one embodiment of which is shown in Fig. 1, is constructed of a plurality of cell units such as cell units 11, 12, 13, and 14 which form single cells 18, 19 and 20. The end cell unit 11 provides a cathode half cell and the end cell unit 14 provides an anodic half cell. The intermediate cell units 12 and 13 are bipolar providing an anodic surface in the direction of cell unit 11 and a cathodic surface in the direction of cell unit 14.
The bipolar cell 10 may be provided with only one intermediate cell unit such as cell unit 12. Alternatively, the cell unit 10 may include two or more intermediate cell units, as desired. The intermediate cell units may be identically constructed.
,,~ .
"~,. ":
The cell unit 13, for example, has a frame 21 including a backplate 22, which serves as a partition between single cells 19 and 20, and peripheral walls 23, 24, 25, and 26. The frame 21 may be constructed of iron or steel. How-ever, the anodic side of the backplate 22 and the inner sur-faces of walls 23, 24, 25, and 26 should have a suitable protective coating, such as of rubber, in order to prevent corrosion. Alternatively, the frame 21 may be of titanium plate or titanium clad steel plate. The peripheral walls, such as wall 24, each includes a pair of flanges 27 and 28 that allow for bolting the cell unit 13 to similar flanges on the adjacent cell units 12 and 14. Of course, the bolts are suitably insulated from the cell units and sealing gas-kets are provided between the meeting surfaces of the adja-cent flanges. Thus, the container for the single cell 19 is provided by the backplate 22 of cell unit 13, the peripheral walls 23, 24, 25, and 26 and the backplate 22 of cell unit 12.
The backplate 22 has at least one opening 34 which allows brine to flow from one cell compartment to the next thereby providing an equal level of brine in each single cell. The backplate 22 further includes openings 33 for mounting of the cathode 16 and anode 17 thereon as herein-after described. The upper portion of backplate 22 provides means for removing the cathodic gas product, for example, hydrogen, from the cell such means including a chamber 37 de-fined by wall 38 and the upper peripheral wall 25. The wall 38 has an opening 39 for passage of hydrogen formed in the hereinafter-described cathodic zone in the cell into chamber ' .
37. The hydrogen gas is removed from chamber 37 through pipe 41. A pipe 42 in the upper peripheral wall 25 is pro-vided for removal of the anodic gas product, for example, chlorine gas which is formed in the anodic zone of the cell.
A pipe 43 is provided in upper peripheral wall 25 for passage of brine into the single cell. The cell products such as caustic soda are removed from the cathodic zone of the cell through pipe 44 in the wall 24.
The cathode 16, as shown in FIGS. 1 and 2, includes a hack screen 47 spaced from plate 22 and finger-like cathode elements 46 which extend perpendicularly from the back screen 47. The finger-like cathode elements are preferably wedge shaped as shown in FIGS. 1 and 2, thus facilitating achieve-ment of a near zero gap between the anode and cathode fingers.
However, the side walls could be parallel with each other.
The cathode fingers 46 and the back screen 47 may be con-structed of material conventionally used in diaphragm cell cathodes for example, the type of screen disclosed in U.S. Patent No. 3,337,443. Cathode finger 46 includes side walls 45 and 50 which are joined at their outermost ends and at their upper and lower edges thus forming a chamber 70 enclosed except for the end which opens into the chamber 75 defined by the backplate 22 and the back screen 47. The chamber 70 and 75 together comprise the cathodic zone of the single cell 20. The cathode fingers 46 and the backscreen 47 are elec-trically interconnected to the backplate 22 and the anode 17.
The screen of the cathode fingers 46 and backscreen 47 is covered with a permeable diaphragm suitably of non-woven 7~) asbestos fabric. Alternatively, the permeable diaphragm may be a permionic membrane. The permeable diaphragm pre-vents undue mixing of the catholyte and anolyte and allows for the collection of anodic and cathodic gases. The cham-bers 70 and 75 communicate with the cathodic gas collection chamber 37 through the opening 39 in wall 38.
The cathode fingers 46 each have a plurality of horizontal bars 48 including laterally extending flanges 49 for supporting the screen forming the cathode fingers and for conducting electrical current to the cathodes. The bars 48 may be constructed of the same type of material as used in backplate 22, for example, iron or steel.
The anodes 17 (FIGS. 1 and 2) are finger-shaped and extend outwardly from the backplate 22. Anode 17 includes a pair of laterally-spaced walls 61 and 62 and a rear wall 63. The walls 61 and 62 may be solid plate or may be of a foraminous or louvered sheet material. Anode 17 has a hori-zontal bar 64 with laterally-extending ~langes 66 for support of the walls 61 and 62. The walls 61 and 62 preferably are disposed so that their outer surfaces are at an angle which is complementary to the angle provided between the pair of adja-cent cathode fingers 46. Thus, when the electrodes are in position of operation shown in FIG. 2, a uniform space is provided between the anodic and cathodic surfaces. The anode 17 including walls 61, 62, and 63 as well as the horizontal bar 64 and flanges 66 and 67 may be constructed of any suit-able anodically-resistant material, preferably titanium. The outer surfaces of solid walls 61 and 62 should be coated with a suitable anodically-resistant electroconductive surface such as a platinum group metal or the oxide of a platinum group metal. If the walls 61 and 62 are foraminous sheets, then the outer and/or inner surfaces may be coated with such metal or metal oxide.
The cathode 16 and anode 17 are mounted on back-plate 22 by electrode support means 52 (FIG. 2). The elec-trode support means 52 includes a block 53 which extends through opening 33 in backplate 22 and is secured therein such as by welding. The block 53 may be constructed of iron rod and has an opening 54 therethrough for reception of screw 56. The screw 56 is threadedly engaged in opening 57 in the corresponding horizontal bar 48 of cathode finger 46. The screw 56 holds the backscreen 47 and the cathode finger 46 snugly against a shoulder 58 of block 53. The opening 54 in block 53 has an enlarged portion 59 of sufficient size to permit the head of the screw 56 to be disposed therewithin.
The rear wall 63 of anode 17 has an opening 68 through which screw 69 extends for threaded engagement in the enlarged por-tion 59 of opening 54 in the block 53. The outer end of anode 17 is open providing access to screw 69 for mounting and dismounting of anode 17. The screw 69 holds the anode 17 securely against block 53 and backplate 22. The screw 69 should be of an anodically-resistant material such as titanium.
Sealing gasket 71 may be provided between the anode 17 and the back plate 22, thereby preventing any anolyte from reaching the block 53 which, if it were to happen, might result in corrosion. A seal 73 should be provided between screw 69 and the backwall 63, thereby preventing leakage of anolyte through opening 68 and into contact with the block 53.
The end cell unit 14 is constructed identical to cell unit 13 except that cell unit 14 does not include a cathode. In other words, the only electrodes mounted on cell unit 14 are anodes. The anodes may extend through the back-plate and be welded or bolted to a copper bus bar.
Cell unit 11 is constructed of a backplate 77 which may be bolted to cell unit 12. Cell unit 11 has a cathode 78 including a backscreen 79 and finger-like cathodes 80. Cath-ode 78 may be mounted on plate 77 in a manner identical to the mounting of cathode 16 on backplate 22 of cell unit 13.
The cell units 11, 12, 13, and 14 are bolted to-gether, forming single cells 18, 19, and 20, and the bolts are suitably insulated to prevent shorting between cell units. Alternatively, the cell units may be secured together by tie rods in a manner conventionally used in filter press type cells. The single cells 18, 19, and 20 are electrically connected in series. During a typical operation, brine is continuously added to each of the single cells through the corresponding pipe 43. The openings 34 between single cells permit equalization of the brine level in each single cell.
The openings 34 further prevent any one of the single cells from going dry, for example, due to a stoppage in pipe 43.
The brine is electrolized in the single cell with anodic products, such as chlorine gas being formed in the anodic zone and cathodic products, such as hydrogen gas and caustic soda being formed in the cathodic zone. The diaphragm 11311~
prevents back migration of the cathodic products into the anodic zone.
Further preferred embodiments of electrode support means are shown in FIGS. 3-12. The bipolar cell units 12A-12I are constructed substantially like cell unit 12 except for the electrode design and electrode support means.
The electrode support means 52A(FIG. 3) includes an elongatedbar or current gatherer 81 which is typical of the current gatherer used in cell units 12A through 12H. The current gatherer is welded to the cathode finger 46A and has openings tnot shown) through which cathodic products formed in fingers 46A may pass to the chamber 75A.A metal block 82 is secured to bar 81 such as by welding. The metal block 82 extends through an opening 83 in backscreen 47A and is se-cured to backplate 22A by screw 84. The screw 84 extends through opening 87 in backplate 22A and is threadedly engaged in opening 88 in block 82. Preferably, the head 89 of screw 84 is countersunk into backplate 22A thereby providing a flat surface against which anode 16A may be mounted. The elec-trode support means 52A further includes a screw 91 which se-cures the anode 16A to backplate 22A. The head 92 of screw 91 is preferably welded to backplate 22A. The screw 91 extends through an opening 9 3 in backplate 22A and an open-ing 94 in the rear wall 63A of anode 17A. The nut 96is tightened down on screw 91 and draws anode 17A snugly and securely against backplate 22A. A seal 97 may be provided between anode 17A and backplate 22A, thereby preventing any leakage between the cathodic compartment and the anodic ~13~1~0 compartment. A seal 90, such as a Thred Seal (Trademark of Parker Seal Company), is provided between nut 96 and wall 63A.
; The bipolar cell unit 12B (FIG. 5) includes an anode 17B, a backplate 22B, and a cathode 16s. The electrode support means 52B includes an elongated bar 101 which is se-cured to cathode finger 46B, for example, by welding. Open-ings, not shown, are provided in bar 101 through which cathodic products may pass. A rod 102 which is threaded at one end is secured to bar 101, such as by welding. The rod 102 extends through opening 103 in backplate 22B. A nut 104 is threadedly engaged with rod 102, thereby securing cathode 16B in place. Preferably, a seal 106 such as a Thred Seal (Trademark of Parker Seal Company) is provided between nut 104 and backplate 22B. The seal 106 prevents leakage through backplate 22B. The rear wall 63B of anode 16B in this embodi-ment is a double wall including wall portions 107 and 108.
The wall portion 107 may be of steel but the wall portion 108 must be of an anodically-resistant material such as titanium.
The wall portion 107 has an opening 109 through which rod 102 , .
extends. A nut 111 secures wall portion 107 to the backplate 22B. The side walls 61B and 62B extend over wall portion 107 and are welded thereto. A screw 112 extends through opening 113 in wall portion 108. The screw 112 may be threadedly en-gaged in a suitable opening in rod 102. Alternatively, the screw 112 may be off set from rod 102, threadedly engaged in a suitable opening in wall portion 107, or screw 112 may be threadedly engaged in a nut disposed on the side of wall por-tion 107 toward backplate 22B. The screw 112 thereby secures 113~
wall portion or cover 108 to wall portion 107. A seal 114 is disposed between wall portion 108 and wall portion 107 and prevents anolyte from contacting wall portion 107. A
further seal 116 is disposed between anode 16B and the back-plate 22B.
The bipolar cell unit 12C (FIG. 6) includes an anode 17C, cathode 16C, and backplate 22C~ The anodes 17C and cathodes 16C are secured to the backplate 22C by the elec-trode support means 52C. The electrode support means 52C
includes an elongated bar 121 which is welded to the finger cathode 46C. Bar 121 has openings therein for passage of cathodic products. A rod 122 is secured to bar 121 and ex-tends through an opening 123 in backplate 22C. The electrode support means 52C further includes a nut 124 which is threadedly engaged with rod 122. The nut 124 serves to hold the cathode 16C in spaced relationship to the backplate 22C.
A nut 125 is threadedly engaged with rod 122 thereby securing cathode 16C to the backplate 22C. A seal 126 may be located between nut 125 and backplate 22C. The anode 17C includes side walls 61C, 62C, and rear wall 63C. The rear wall 63C
includes an opening 128 through which extends a screw 129.
Screw 129 is threadedly engaged in rod 122 and secures the anode 17C to the backplate 22C. The screw 129 draws rear surface 127 of wall 63C into electrical contact with rod 122 and nut 125. Seals 131 and 132 are provided to prevent leak-age of anolyte into contact with steel parts such as rod 122 and backplate 22C.
1~311~70 ; The cell unit(12D FIG. 7) includes an anode 17D, cathode 16D, and a backplate 22D. The electrode support means 52D in this embodiment comprises an elongated bar 141 which is welded to the cathode finger 46D, the electrode support means 52D further includes the connecting block 142 which is attached to bar 141 such as by welding. The block 142 ex-tends through an opening 143 in backplate 22D. The anode 17D
J
is secured in place by screw 144 which extends through open-ing 146 in rear wall 43D and is threadedly engaged in opening 147 in block 142. The block 142, if desired, may be welded to the backplate 22D.
The electrode support means 52E of bipolar cell unit 12E (FIG. 8) includes an elongated bar or current gath-erer 151 which is welded to the cathode finger 46E. The electrode support means 52E further includes a rod 152 which is welded to the bar 151 and extends through an opening 153 in backplate 22E. A nut 154 is threadedly engaged with rod 152 thereby holding cathode 16E in place. A seal 156 may be provided between nut 154 and the backplate 22E. The rod 152 extends through an opening 157 in the rear wall 63E of anode 17E. A threaded cap 158 is threadedly engaged with rod 152 thereby holding anode 17E in place. A seal 159 is provided between cap 158 and the rear wall 63E. A seal 160 is pro-vided between the anode 17E and the backplate 22E.
The electrode support means 52F of bipolar cell unit 12F (FIG. 9) includes an elongated bar 171 which is welded to the fingered cathode 46F, a block 172 which is welded to bar 171 is threaded so that the nut 173 may be tightened against the rear screen 47F. The block 172 has a portion 174 of reduced diameter which extends through the opening 176 in the backplate 22F. The block 172 has a shoulder 177 which abuts against the backplate 22F thereby holding the backscreen 47F at a point spaced from backplate 22F. The screw 178 secures anode 17F to the backplate 22F. The screw 178 extends through opening 179 in rear wall 63F and is threadedly engaged in opening 181 in the block 172. The screw 178 holds the meeting surfaces of wall 63F and block 172 in electrical contact with one another. A seal 182 is provided between the head of screw 17B and wall 63F and a seal 183 is provided between anode 17F and backplate 22F.
The seals 182 and 183 may be of EPDM rubber (ASTM designa-tion) which has excellent resistance to corrosion and remains resilient even after extended periods of cell operation at high temperatures.
The bipolar cell unit 12G (FIG. 10) has an elec-trode support means 52G including a current gatherer 191 which is welded to the cathode finger 46G. A threaded rod 192 is welded to the current gatherer 191. A nut 193 is threadedly engaged with rod 192 and securely holds the back-screen 47G against the fingered electrode 46G. A nut 194 is threadedly engaged with rod 192 and holds the cathode 16G at a point spaced from the backplate 22G. The rod 192 extends through opening 196 in the backplate 22G. The anode 17G in this instance includes only one side wall comprised of a plate of titanium or a titanium group metal having an electrocon-ductive surface on both sides thereof. The side wall 61G, ~3~7(~
when the cell is operating, is disposed eq~ clistant between a pair of fingered cathodes (not shown) of the adjacent cel] unit. The anode 17G further includes a rear wall 63G which is welded to side wall 61G. The rear wall 63G has an opening 197 through which a screw 198 extends for threaded engagement in an opening 199 in the rod 192. The screw 198 securely holds the anode 17G
in place against the backplate 22G.
In the embodiment illustrated in Figure 10, the anode component ; of the cell unit is in the form of a thin anodically-resistant vertically disposed sheet or plate having substantially parallel flat surfaces of appropriate electro-conductive material upon which anolyte products of electrolysis (e. g., chlorine) form When assembled in the electrolytic cell, each thin anode plate (of which there are a plurality in each cell unit) is interleaved between, but spaced laterally of opposed cathode fingers of adjacent cathodes extending outwardly from the adjacent cell unit. The vertical edge of the sheet-like anode termi-nates parallel to and spaced from the backplate of the adjacent cell unit.
The cell unit 12H (Fig. 11) includes an electrode support means 52H having a current gatherer 211 which is welded to the finger cathode 46H.
The current gatherer 211 may be a discontinuous bar, thus permitting cathodic products to pass from the finger to the space between the screen 47H and plate 22H. A threaded rod 212 is welded to the current gatherer 211. A nut 213 is threadedly engaged with rod 212 for purposes of holding the backscreen 47H securely against the fingered electrode 46H. The electrode support 52H
further includes a nut 214 for controlling the extent to which the threaded rod 212 extends through the opening 216 in the backplate 22H. Ribs 223 are pro-vided for spacing screen 47H from plate 22H. The ribs 223 may be of steel and are welded to plate 22H. The screen 47H is slightly flexible, thus permitting adjustment of rod 212 with respect to backplate 22H. The anode assembly 17H in this embodiment carries a narrow anode member 217, including a pair of side walls 61H and 62H which are welded to the rear wall 63H. A screw 219 extends through opening 221 in rear wall 63H and is threaded engaged in the opening 222 in rod 212. The screw 219 securely r etains the anode 17 H against the B
113~17(9 backplate 22B and maintains excellent electrical contact between the meeting surfaces of wall 63H and rod 212.
The cell unit 12J(FIG. 12) includes cathodes 16I
and anodes 17I which are mounted on a backplate 22I such as by electrode support means 52I. The cathodes 16I may be con-structèd substantially like cathodes 16 shown in FIGS. 1 and
A variety of types of electrolytic cells employing a bipolar electrode assembly and a permeable diaphragm have been known in the past. The present trend in this type of cell i~ to provide within a single cell housing a plurality of individual cell units ut;lizing bipolar electrode ~13~l17(:~
structures. In such an electrode structure, the anodes o one cell are posi-tioned in a back-to-back relationship with the cathodes of the adjacent cell and electrical contact is maintained between the two. The supporting wall for the anodes and cathodes in the back-to-back relationship functions also to physically separate the cells within the over-all cell housing.
The present invention provides an improved bipolar diaphragm cell of the described type. The present invention provides a diaphragm cell which is particularly light in weight and easy to assemble and disassemble.
The present invention furthermore provides a diaphragm cell having improved electrical connection between the cathode and anode.
Herein the term "cell unit" is used to describe the back-to-back bipolar assembly of the anodes of one cell with the cathode of the adjacent cell. Each cell thus is made up of cathodes from one cell unit interleaved and spaced from anodes of the next adjacent cell unit. The cathodes character-istically have elongated hollow portions which are interleaved or interposition-ed with and spaced from the anodes of the next adjacent cell unit. The cathodes are constructed of metal wire screening or the like perforated sheeting and are covered with a permeable diaphragm, for example, asbestos. The metal wire screening may be of any suitable metal, for example, steel or, alternat-ively, nickel or chromium or other metal sufficiently resistant to corrosion under the conditions prevailing in the catholyte during electrolysis.
The finger-like anode elements may be provided by a single sheet or wall-like element or may comprise a pair of laterally-spaced vertical walls and which are open along the outer end of the elements. The anodes are constructed of any suitable chlorine-resistant metal such as titanium having an electroconductive surface of a platinum group metal or the oxide of a platinum group metal. The term "single cell" is used to describe the cell formed by the finger-like anodes of one cell unit which are interleaved with the finger-like cathodes of the adjacent cell unit.
Another important component of the cell unit is the supporting wall or backplate. As shown in the specific embodiments hereinafter described, the backplate may serve one or more purposes including that of (1) the prime structural element for supporting the plurality of anodes and cathodes which B
11311~
make up the cell unit, (2) the principal structure which divides the entire electrolytic cell (electrolyzer) into its connponent cells and 13) the conductorby which the current flows from cell to cell. For the backplate to perform such functions it should be of appropriate construction and materials. One especially useful type of electroconductive backplate has its anodic side (or surface) of titanium and its cathodic surface of steel. These surfaces are each resistant enough to the respective cell environments to which they are exposed during cell operation to provide for long backplate life.
The present invention will be further illustrated by way of the accompanying drawings in which:
Fig. 1 shows a perspective view of the bipolar cell of the present invention with portions of the cell housing broken away.
Fig. 2 shows an enlarged portion of the electrodes taken along the line II-II in Fig. 1.
Figs. 3 - 12 illustrate alternate means for mounting the electrodes to the support wall of the present inventionO
Figs. 13-15 is another preferred embodiment of the present invention.
The bipolar diaphragm cell 10, one embodiment of which is shown in Fig. 1, is constructed of a plurality of cell units such as cell units 11, 12, 13, and 14 which form single cells 18, 19 and 20. The end cell unit 11 provides a cathode half cell and the end cell unit 14 provides an anodic half cell. The intermediate cell units 12 and 13 are bipolar providing an anodic surface in the direction of cell unit 11 and a cathodic surface in the direction of cell unit 14.
The bipolar cell 10 may be provided with only one intermediate cell unit such as cell unit 12. Alternatively, the cell unit 10 may include two or more intermediate cell units, as desired. The intermediate cell units may be identically constructed.
,,~ .
"~,. ":
The cell unit 13, for example, has a frame 21 including a backplate 22, which serves as a partition between single cells 19 and 20, and peripheral walls 23, 24, 25, and 26. The frame 21 may be constructed of iron or steel. How-ever, the anodic side of the backplate 22 and the inner sur-faces of walls 23, 24, 25, and 26 should have a suitable protective coating, such as of rubber, in order to prevent corrosion. Alternatively, the frame 21 may be of titanium plate or titanium clad steel plate. The peripheral walls, such as wall 24, each includes a pair of flanges 27 and 28 that allow for bolting the cell unit 13 to similar flanges on the adjacent cell units 12 and 14. Of course, the bolts are suitably insulated from the cell units and sealing gas-kets are provided between the meeting surfaces of the adja-cent flanges. Thus, the container for the single cell 19 is provided by the backplate 22 of cell unit 13, the peripheral walls 23, 24, 25, and 26 and the backplate 22 of cell unit 12.
The backplate 22 has at least one opening 34 which allows brine to flow from one cell compartment to the next thereby providing an equal level of brine in each single cell. The backplate 22 further includes openings 33 for mounting of the cathode 16 and anode 17 thereon as herein-after described. The upper portion of backplate 22 provides means for removing the cathodic gas product, for example, hydrogen, from the cell such means including a chamber 37 de-fined by wall 38 and the upper peripheral wall 25. The wall 38 has an opening 39 for passage of hydrogen formed in the hereinafter-described cathodic zone in the cell into chamber ' .
37. The hydrogen gas is removed from chamber 37 through pipe 41. A pipe 42 in the upper peripheral wall 25 is pro-vided for removal of the anodic gas product, for example, chlorine gas which is formed in the anodic zone of the cell.
A pipe 43 is provided in upper peripheral wall 25 for passage of brine into the single cell. The cell products such as caustic soda are removed from the cathodic zone of the cell through pipe 44 in the wall 24.
The cathode 16, as shown in FIGS. 1 and 2, includes a hack screen 47 spaced from plate 22 and finger-like cathode elements 46 which extend perpendicularly from the back screen 47. The finger-like cathode elements are preferably wedge shaped as shown in FIGS. 1 and 2, thus facilitating achieve-ment of a near zero gap between the anode and cathode fingers.
However, the side walls could be parallel with each other.
The cathode fingers 46 and the back screen 47 may be con-structed of material conventionally used in diaphragm cell cathodes for example, the type of screen disclosed in U.S. Patent No. 3,337,443. Cathode finger 46 includes side walls 45 and 50 which are joined at their outermost ends and at their upper and lower edges thus forming a chamber 70 enclosed except for the end which opens into the chamber 75 defined by the backplate 22 and the back screen 47. The chamber 70 and 75 together comprise the cathodic zone of the single cell 20. The cathode fingers 46 and the backscreen 47 are elec-trically interconnected to the backplate 22 and the anode 17.
The screen of the cathode fingers 46 and backscreen 47 is covered with a permeable diaphragm suitably of non-woven 7~) asbestos fabric. Alternatively, the permeable diaphragm may be a permionic membrane. The permeable diaphragm pre-vents undue mixing of the catholyte and anolyte and allows for the collection of anodic and cathodic gases. The cham-bers 70 and 75 communicate with the cathodic gas collection chamber 37 through the opening 39 in wall 38.
The cathode fingers 46 each have a plurality of horizontal bars 48 including laterally extending flanges 49 for supporting the screen forming the cathode fingers and for conducting electrical current to the cathodes. The bars 48 may be constructed of the same type of material as used in backplate 22, for example, iron or steel.
The anodes 17 (FIGS. 1 and 2) are finger-shaped and extend outwardly from the backplate 22. Anode 17 includes a pair of laterally-spaced walls 61 and 62 and a rear wall 63. The walls 61 and 62 may be solid plate or may be of a foraminous or louvered sheet material. Anode 17 has a hori-zontal bar 64 with laterally-extending ~langes 66 for support of the walls 61 and 62. The walls 61 and 62 preferably are disposed so that their outer surfaces are at an angle which is complementary to the angle provided between the pair of adja-cent cathode fingers 46. Thus, when the electrodes are in position of operation shown in FIG. 2, a uniform space is provided between the anodic and cathodic surfaces. The anode 17 including walls 61, 62, and 63 as well as the horizontal bar 64 and flanges 66 and 67 may be constructed of any suit-able anodically-resistant material, preferably titanium. The outer surfaces of solid walls 61 and 62 should be coated with a suitable anodically-resistant electroconductive surface such as a platinum group metal or the oxide of a platinum group metal. If the walls 61 and 62 are foraminous sheets, then the outer and/or inner surfaces may be coated with such metal or metal oxide.
The cathode 16 and anode 17 are mounted on back-plate 22 by electrode support means 52 (FIG. 2). The elec-trode support means 52 includes a block 53 which extends through opening 33 in backplate 22 and is secured therein such as by welding. The block 53 may be constructed of iron rod and has an opening 54 therethrough for reception of screw 56. The screw 56 is threadedly engaged in opening 57 in the corresponding horizontal bar 48 of cathode finger 46. The screw 56 holds the backscreen 47 and the cathode finger 46 snugly against a shoulder 58 of block 53. The opening 54 in block 53 has an enlarged portion 59 of sufficient size to permit the head of the screw 56 to be disposed therewithin.
The rear wall 63 of anode 17 has an opening 68 through which screw 69 extends for threaded engagement in the enlarged por-tion 59 of opening 54 in the block 53. The outer end of anode 17 is open providing access to screw 69 for mounting and dismounting of anode 17. The screw 69 holds the anode 17 securely against block 53 and backplate 22. The screw 69 should be of an anodically-resistant material such as titanium.
Sealing gasket 71 may be provided between the anode 17 and the back plate 22, thereby preventing any anolyte from reaching the block 53 which, if it were to happen, might result in corrosion. A seal 73 should be provided between screw 69 and the backwall 63, thereby preventing leakage of anolyte through opening 68 and into contact with the block 53.
The end cell unit 14 is constructed identical to cell unit 13 except that cell unit 14 does not include a cathode. In other words, the only electrodes mounted on cell unit 14 are anodes. The anodes may extend through the back-plate and be welded or bolted to a copper bus bar.
Cell unit 11 is constructed of a backplate 77 which may be bolted to cell unit 12. Cell unit 11 has a cathode 78 including a backscreen 79 and finger-like cathodes 80. Cath-ode 78 may be mounted on plate 77 in a manner identical to the mounting of cathode 16 on backplate 22 of cell unit 13.
The cell units 11, 12, 13, and 14 are bolted to-gether, forming single cells 18, 19, and 20, and the bolts are suitably insulated to prevent shorting between cell units. Alternatively, the cell units may be secured together by tie rods in a manner conventionally used in filter press type cells. The single cells 18, 19, and 20 are electrically connected in series. During a typical operation, brine is continuously added to each of the single cells through the corresponding pipe 43. The openings 34 between single cells permit equalization of the brine level in each single cell.
The openings 34 further prevent any one of the single cells from going dry, for example, due to a stoppage in pipe 43.
The brine is electrolized in the single cell with anodic products, such as chlorine gas being formed in the anodic zone and cathodic products, such as hydrogen gas and caustic soda being formed in the cathodic zone. The diaphragm 11311~
prevents back migration of the cathodic products into the anodic zone.
Further preferred embodiments of electrode support means are shown in FIGS. 3-12. The bipolar cell units 12A-12I are constructed substantially like cell unit 12 except for the electrode design and electrode support means.
The electrode support means 52A(FIG. 3) includes an elongatedbar or current gatherer 81 which is typical of the current gatherer used in cell units 12A through 12H. The current gatherer is welded to the cathode finger 46A and has openings tnot shown) through which cathodic products formed in fingers 46A may pass to the chamber 75A.A metal block 82 is secured to bar 81 such as by welding. The metal block 82 extends through an opening 83 in backscreen 47A and is se-cured to backplate 22A by screw 84. The screw 84 extends through opening 87 in backplate 22A and is threadedly engaged in opening 88 in block 82. Preferably, the head 89 of screw 84 is countersunk into backplate 22A thereby providing a flat surface against which anode 16A may be mounted. The elec-trode support means 52A further includes a screw 91 which se-cures the anode 16A to backplate 22A. The head 92 of screw 91 is preferably welded to backplate 22A. The screw 91 extends through an opening 9 3 in backplate 22A and an open-ing 94 in the rear wall 63A of anode 17A. The nut 96is tightened down on screw 91 and draws anode 17A snugly and securely against backplate 22A. A seal 97 may be provided between anode 17A and backplate 22A, thereby preventing any leakage between the cathodic compartment and the anodic ~13~1~0 compartment. A seal 90, such as a Thred Seal (Trademark of Parker Seal Company), is provided between nut 96 and wall 63A.
; The bipolar cell unit 12B (FIG. 5) includes an anode 17B, a backplate 22B, and a cathode 16s. The electrode support means 52B includes an elongated bar 101 which is se-cured to cathode finger 46B, for example, by welding. Open-ings, not shown, are provided in bar 101 through which cathodic products may pass. A rod 102 which is threaded at one end is secured to bar 101, such as by welding. The rod 102 extends through opening 103 in backplate 22B. A nut 104 is threadedly engaged with rod 102, thereby securing cathode 16B in place. Preferably, a seal 106 such as a Thred Seal (Trademark of Parker Seal Company) is provided between nut 104 and backplate 22B. The seal 106 prevents leakage through backplate 22B. The rear wall 63B of anode 16B in this embodi-ment is a double wall including wall portions 107 and 108.
The wall portion 107 may be of steel but the wall portion 108 must be of an anodically-resistant material such as titanium.
The wall portion 107 has an opening 109 through which rod 102 , .
extends. A nut 111 secures wall portion 107 to the backplate 22B. The side walls 61B and 62B extend over wall portion 107 and are welded thereto. A screw 112 extends through opening 113 in wall portion 108. The screw 112 may be threadedly en-gaged in a suitable opening in rod 102. Alternatively, the screw 112 may be off set from rod 102, threadedly engaged in a suitable opening in wall portion 107, or screw 112 may be threadedly engaged in a nut disposed on the side of wall por-tion 107 toward backplate 22B. The screw 112 thereby secures 113~
wall portion or cover 108 to wall portion 107. A seal 114 is disposed between wall portion 108 and wall portion 107 and prevents anolyte from contacting wall portion 107. A
further seal 116 is disposed between anode 16B and the back-plate 22B.
The bipolar cell unit 12C (FIG. 6) includes an anode 17C, cathode 16C, and backplate 22C~ The anodes 17C and cathodes 16C are secured to the backplate 22C by the elec-trode support means 52C. The electrode support means 52C
includes an elongated bar 121 which is welded to the finger cathode 46C. Bar 121 has openings therein for passage of cathodic products. A rod 122 is secured to bar 121 and ex-tends through an opening 123 in backplate 22C. The electrode support means 52C further includes a nut 124 which is threadedly engaged with rod 122. The nut 124 serves to hold the cathode 16C in spaced relationship to the backplate 22C.
A nut 125 is threadedly engaged with rod 122 thereby securing cathode 16C to the backplate 22C. A seal 126 may be located between nut 125 and backplate 22C. The anode 17C includes side walls 61C, 62C, and rear wall 63C. The rear wall 63C
includes an opening 128 through which extends a screw 129.
Screw 129 is threadedly engaged in rod 122 and secures the anode 17C to the backplate 22C. The screw 129 draws rear surface 127 of wall 63C into electrical contact with rod 122 and nut 125. Seals 131 and 132 are provided to prevent leak-age of anolyte into contact with steel parts such as rod 122 and backplate 22C.
1~311~70 ; The cell unit(12D FIG. 7) includes an anode 17D, cathode 16D, and a backplate 22D. The electrode support means 52D in this embodiment comprises an elongated bar 141 which is welded to the cathode finger 46D, the electrode support means 52D further includes the connecting block 142 which is attached to bar 141 such as by welding. The block 142 ex-tends through an opening 143 in backplate 22D. The anode 17D
J
is secured in place by screw 144 which extends through open-ing 146 in rear wall 43D and is threadedly engaged in opening 147 in block 142. The block 142, if desired, may be welded to the backplate 22D.
The electrode support means 52E of bipolar cell unit 12E (FIG. 8) includes an elongated bar or current gath-erer 151 which is welded to the cathode finger 46E. The electrode support means 52E further includes a rod 152 which is welded to the bar 151 and extends through an opening 153 in backplate 22E. A nut 154 is threadedly engaged with rod 152 thereby holding cathode 16E in place. A seal 156 may be provided between nut 154 and the backplate 22E. The rod 152 extends through an opening 157 in the rear wall 63E of anode 17E. A threaded cap 158 is threadedly engaged with rod 152 thereby holding anode 17E in place. A seal 159 is provided between cap 158 and the rear wall 63E. A seal 160 is pro-vided between the anode 17E and the backplate 22E.
The electrode support means 52F of bipolar cell unit 12F (FIG. 9) includes an elongated bar 171 which is welded to the fingered cathode 46F, a block 172 which is welded to bar 171 is threaded so that the nut 173 may be tightened against the rear screen 47F. The block 172 has a portion 174 of reduced diameter which extends through the opening 176 in the backplate 22F. The block 172 has a shoulder 177 which abuts against the backplate 22F thereby holding the backscreen 47F at a point spaced from backplate 22F. The screw 178 secures anode 17F to the backplate 22F. The screw 178 extends through opening 179 in rear wall 63F and is threadedly engaged in opening 181 in the block 172. The screw 178 holds the meeting surfaces of wall 63F and block 172 in electrical contact with one another. A seal 182 is provided between the head of screw 17B and wall 63F and a seal 183 is provided between anode 17F and backplate 22F.
The seals 182 and 183 may be of EPDM rubber (ASTM designa-tion) which has excellent resistance to corrosion and remains resilient even after extended periods of cell operation at high temperatures.
The bipolar cell unit 12G (FIG. 10) has an elec-trode support means 52G including a current gatherer 191 which is welded to the cathode finger 46G. A threaded rod 192 is welded to the current gatherer 191. A nut 193 is threadedly engaged with rod 192 and securely holds the back-screen 47G against the fingered electrode 46G. A nut 194 is threadedly engaged with rod 192 and holds the cathode 16G at a point spaced from the backplate 22G. The rod 192 extends through opening 196 in the backplate 22G. The anode 17G in this instance includes only one side wall comprised of a plate of titanium or a titanium group metal having an electrocon-ductive surface on both sides thereof. The side wall 61G, ~3~7(~
when the cell is operating, is disposed eq~ clistant between a pair of fingered cathodes (not shown) of the adjacent cel] unit. The anode 17G further includes a rear wall 63G which is welded to side wall 61G. The rear wall 63G has an opening 197 through which a screw 198 extends for threaded engagement in an opening 199 in the rod 192. The screw 198 securely holds the anode 17G
in place against the backplate 22G.
In the embodiment illustrated in Figure 10, the anode component ; of the cell unit is in the form of a thin anodically-resistant vertically disposed sheet or plate having substantially parallel flat surfaces of appropriate electro-conductive material upon which anolyte products of electrolysis (e. g., chlorine) form When assembled in the electrolytic cell, each thin anode plate (of which there are a plurality in each cell unit) is interleaved between, but spaced laterally of opposed cathode fingers of adjacent cathodes extending outwardly from the adjacent cell unit. The vertical edge of the sheet-like anode termi-nates parallel to and spaced from the backplate of the adjacent cell unit.
The cell unit 12H (Fig. 11) includes an electrode support means 52H having a current gatherer 211 which is welded to the finger cathode 46H.
The current gatherer 211 may be a discontinuous bar, thus permitting cathodic products to pass from the finger to the space between the screen 47H and plate 22H. A threaded rod 212 is welded to the current gatherer 211. A nut 213 is threadedly engaged with rod 212 for purposes of holding the backscreen 47H securely against the fingered electrode 46H. The electrode support 52H
further includes a nut 214 for controlling the extent to which the threaded rod 212 extends through the opening 216 in the backplate 22H. Ribs 223 are pro-vided for spacing screen 47H from plate 22H. The ribs 223 may be of steel and are welded to plate 22H. The screen 47H is slightly flexible, thus permitting adjustment of rod 212 with respect to backplate 22H. The anode assembly 17H in this embodiment carries a narrow anode member 217, including a pair of side walls 61H and 62H which are welded to the rear wall 63H. A screw 219 extends through opening 221 in rear wall 63H and is threaded engaged in the opening 222 in rod 212. The screw 219 securely r etains the anode 17 H against the B
113~17(9 backplate 22B and maintains excellent electrical contact between the meeting surfaces of wall 63H and rod 212.
The cell unit 12J(FIG. 12) includes cathodes 16I
and anodes 17I which are mounted on a backplate 22I such as by electrode support means 52I. The cathodes 16I may be con-structèd substantially like cathodes 16 shown in FIGS. 1 and
2. However, in this instance the rear portions 225 and 226 of side walls 45I and 50I are flared thereby providing fin-gers 46I with a wider base for resting against back screen 47I and permitting flexing of cathode 16I during adjustment of the block 228 with respect to backplate 22I.
The electrode support means 52I includes a current gatherer 227 which is an elongated bar having openings therein through which cathode products may pass. The current gath-erer 227is welded to side walls 45I and 50I of cathode 16I.
The electrode support means 52I further includes a threaded rod 228 which is welded to the current gatherer 227 and ex-tends through opening 229 in backscreen 47I and opening 230 in backplate 22I.A nut 233is threadedly engaged with rod 228 and retains cathode finger 46I securely against back-screen 47I. Nut 234is threadedly engaged with rod 228 and holds the cathode 16I, including backscreen 47I and finger 46I, securely against backplate 22I. A screw 236, preferably of titanium metal, extends through opening 237 in rear wall 631 of anode 17I and is threadedly engaged in opening 235 in rod 228.A titanium thread seal washer 238is provided be-tween screw 236 and backplate 22I.A rubber gasket 239is provided between anode 17I and backplate 22I. A plurality of 17(:~
of spacer bars Z41 are provided between backscreen 47I and backplate 22I.
The bars 241 hold the cathode l71 spaced from the backplate 22I and may be constructed of any material which is corrosion resistant in a cathode environ-ment, for example, steel or copper. The ring nut 234 adjusts the distance rod 228 extends through plate 221, thus assuring proper contact between the surfaces of wall 63I and rod 228. Furthermore, use of ring nut 234 permits use of a smaller screw 236 than would otherwise be necessaryO The rear wall 63T may be a continuous wall the full length of the anode 17I or may be comprised of a plurality of discontinuous wall portions, for example, one such wall portion being provided for each electrode support means. Alternative-ly, all of the anodes l7I for a cell unit could be mounted on a single rear wall631. Furthermore, wall 22I could serve as the rear wall of anodes 171 in whichcase wall 221 may be a titanium clad steel plate and the walls 61T
and 62T may be welded thereto.
Furthermore, wall 22I could serve as the rear wall of anodes 171 in which case wall (backplate) 22I may ideally be a titanium clad steel plate and anode walls 611 and 621 may be welded thereto. Wall 22I thus is provided on its anodic face with a titanium surface ~an electroconductive material chem-ically resistant to the anolyte environment) and on its cathodic side with an iron surface (an electroconductive material resistant to the catholyte environ-ment). Although, because of availability, cost and structural strength, backplates of titanium clad steel are specially preferred, backplates may have surfaces of other materials meeting certain electrical and corrosion resistant standards.
The anodes 17I each include side walls 6lr and 62T which may be secured such as by welding to a rear wall 63I. The side walls 611 and 621 of anode 17I are diverging rather than converging. In other words, the space between walls 61T and 62I is less adjacent rear wall 63T than it is at the edge opposite rear wall 631. The side walls 61T and 621 may have stiffening rods 242, if desired. The stiffening rods 242 may be welded to the outer sides of walls 61I and 62I. In this embodiment, the cathode finger 46I
lies between the side walls 61I and 621 of anode l7r of the next adjacent cell unit. For further strengthening providing improved electrode ~, -16--, ,i 1~3~
spacing, the side wall 61I of one anode finger 17I may be secured at the forward edge thereof to the side wall 62I of the next adjacent anode finger, such as by connector 243.
The connector 243 in this instance includes a screw 244 which extends through an opening in wall 62I and is thread-edly engaged in nut 245. The nut 245is secured to side wall 61I such as by welding. The connector 243 alternatively may be a metal clip.
Cell lOJ, shown in FIGS. 13-15,is a further em-bodiment of the present invention. Cell lOJ is constructed similar to cell 10 of FIG. 1. Cell lOJ has a cell container or frame 21J which, if desired, may be identical to frame 21 shown in FIG. 1. Cell lOJ further includes a plurality of wedge-shaped cathodes 16J and anodes 17J which are mounted on backplate 22J by an electrode support means 52J. In this embodiment, the thin edge 255 of wedge-shaped electrodes lies in a horizontal plate or, in other words, the thin edge of the electrodes extends perpendicular to the vertical backplate 22J. The cathode 16J has a pair of side walls 45J and 50J, a bottom wall 252, and an outer end wall 253. The walls 45J, 50J, 252, and 253 may be constructed of screen. The walls 45J and 50J, as shown in FIG. 14, converge upwardly. If de-sired, baffles 254 (FIG. 13) may be provided in cathode 16J
to force product gases from the cathode wedges into the space between the back screen 47J and the backplate 22J. The anode 17J includes a pair of side walls 61J and 62J which are pref-erably constructed of foraminous plates. The anode 17J fur-ther includes a backplate 63J. The electrode support means 1~31170 52J, shown in detail in FIG. 15, is comprised of a current gathering bar 256 which is secured to walls 45J and 50J adja-cent the open end of cathode 16J, for example, by welding.
The electrode support means 52J further includes a rod 257 which is secured to bar 256 and extends through openings in the backplate 22J and rear wall 63J of anode 17J. A nut 258 is threadedly engaged with rod 257, thereby securing anode 17J and cathode 16J to the backplate 22J.
The anodes 17 through 17J have generally been described as being constructed of a titanium group metal with the walls 61 - 61J and 62 - 62J being solid plates and the titanium plates being platinized on the side adjacent the cathode fingers 47 - 47J. The anodes 17 - 17J may alterna-tively have side walls constructed of a pervious, anodically-resistant plate, for example, of rod material, screen, ex-panded metal mesh, perforated plate, or louvered plate. The pervious plate may be of titanium metal. Preferably, the pervious titanium plate has en electroconductive surface, for example, of platinum, only on the side remote from the cathode fingers. By so doing, the titanium metal forms a non-conductive titanium oxide coating adjacent the diaphragm and gas evolution during cell operation takes place on the back side of the side walls, thus substantially reducing gas blinding and turbulence in the diaphragm. Furthermore, the side of the cathode back screen and cathode fingers toward the anode may be electrically insulated such as with a rubber coating. By so doing, the cathodic gas products would be produced on tbe back side of the cathode which would further 1131~
reduce gas blinding and back migration of caustic soda. This arrangement would provide a highly-efficient cell, particularly if the porosity of the diaphragm is slightly increased and the cell is operated at a high brine flow rate and a high current density such as in excess of 150, preferably in excess of 200, amperes per square foot of cathode surface, as defined by length and breadth measurements of the cathode.
The cell of the present invention, especially when using wedge-shaped foraminous anodes and cathodes, operates in a very efficient manner when the anode-to-cathode gap is near zero, for example, generally less than 1/2 inch, typi-cally, 1/8 to 1/4 inch and, preferably, the anode is directly against the diaphragm.
Although the present invention has been described with reference to specific details of particular embodiments thereof, it is not intended thereby to limit the scope of the invention except insofar as the specific details are recited in the appended claims. For example, one skilled in the art may replace the non-woven asbestos fabric with a permionic membrane.
The electrode support means 52I includes a current gatherer 227 which is an elongated bar having openings therein through which cathode products may pass. The current gath-erer 227is welded to side walls 45I and 50I of cathode 16I.
The electrode support means 52I further includes a threaded rod 228 which is welded to the current gatherer 227 and ex-tends through opening 229 in backscreen 47I and opening 230 in backplate 22I.A nut 233is threadedly engaged with rod 228 and retains cathode finger 46I securely against back-screen 47I. Nut 234is threadedly engaged with rod 228 and holds the cathode 16I, including backscreen 47I and finger 46I, securely against backplate 22I. A screw 236, preferably of titanium metal, extends through opening 237 in rear wall 631 of anode 17I and is threadedly engaged in opening 235 in rod 228.A titanium thread seal washer 238is provided be-tween screw 236 and backplate 22I.A rubber gasket 239is provided between anode 17I and backplate 22I. A plurality of 17(:~
of spacer bars Z41 are provided between backscreen 47I and backplate 22I.
The bars 241 hold the cathode l71 spaced from the backplate 22I and may be constructed of any material which is corrosion resistant in a cathode environ-ment, for example, steel or copper. The ring nut 234 adjusts the distance rod 228 extends through plate 221, thus assuring proper contact between the surfaces of wall 63I and rod 228. Furthermore, use of ring nut 234 permits use of a smaller screw 236 than would otherwise be necessaryO The rear wall 63T may be a continuous wall the full length of the anode 17I or may be comprised of a plurality of discontinuous wall portions, for example, one such wall portion being provided for each electrode support means. Alternative-ly, all of the anodes l7I for a cell unit could be mounted on a single rear wall631. Furthermore, wall 22I could serve as the rear wall of anodes 171 in whichcase wall 221 may be a titanium clad steel plate and the walls 61T
and 62T may be welded thereto.
Furthermore, wall 22I could serve as the rear wall of anodes 171 in which case wall (backplate) 22I may ideally be a titanium clad steel plate and anode walls 611 and 621 may be welded thereto. Wall 22I thus is provided on its anodic face with a titanium surface ~an electroconductive material chem-ically resistant to the anolyte environment) and on its cathodic side with an iron surface (an electroconductive material resistant to the catholyte environ-ment). Although, because of availability, cost and structural strength, backplates of titanium clad steel are specially preferred, backplates may have surfaces of other materials meeting certain electrical and corrosion resistant standards.
The anodes 17I each include side walls 6lr and 62T which may be secured such as by welding to a rear wall 63I. The side walls 611 and 621 of anode 17I are diverging rather than converging. In other words, the space between walls 61T and 62I is less adjacent rear wall 63T than it is at the edge opposite rear wall 631. The side walls 61T and 621 may have stiffening rods 242, if desired. The stiffening rods 242 may be welded to the outer sides of walls 61I and 62I. In this embodiment, the cathode finger 46I
lies between the side walls 61I and 621 of anode l7r of the next adjacent cell unit. For further strengthening providing improved electrode ~, -16--, ,i 1~3~
spacing, the side wall 61I of one anode finger 17I may be secured at the forward edge thereof to the side wall 62I of the next adjacent anode finger, such as by connector 243.
The connector 243 in this instance includes a screw 244 which extends through an opening in wall 62I and is thread-edly engaged in nut 245. The nut 245is secured to side wall 61I such as by welding. The connector 243 alternatively may be a metal clip.
Cell lOJ, shown in FIGS. 13-15,is a further em-bodiment of the present invention. Cell lOJ is constructed similar to cell 10 of FIG. 1. Cell lOJ has a cell container or frame 21J which, if desired, may be identical to frame 21 shown in FIG. 1. Cell lOJ further includes a plurality of wedge-shaped cathodes 16J and anodes 17J which are mounted on backplate 22J by an electrode support means 52J. In this embodiment, the thin edge 255 of wedge-shaped electrodes lies in a horizontal plate or, in other words, the thin edge of the electrodes extends perpendicular to the vertical backplate 22J. The cathode 16J has a pair of side walls 45J and 50J, a bottom wall 252, and an outer end wall 253. The walls 45J, 50J, 252, and 253 may be constructed of screen. The walls 45J and 50J, as shown in FIG. 14, converge upwardly. If de-sired, baffles 254 (FIG. 13) may be provided in cathode 16J
to force product gases from the cathode wedges into the space between the back screen 47J and the backplate 22J. The anode 17J includes a pair of side walls 61J and 62J which are pref-erably constructed of foraminous plates. The anode 17J fur-ther includes a backplate 63J. The electrode support means 1~31170 52J, shown in detail in FIG. 15, is comprised of a current gathering bar 256 which is secured to walls 45J and 50J adja-cent the open end of cathode 16J, for example, by welding.
The electrode support means 52J further includes a rod 257 which is secured to bar 256 and extends through openings in the backplate 22J and rear wall 63J of anode 17J. A nut 258 is threadedly engaged with rod 257, thereby securing anode 17J and cathode 16J to the backplate 22J.
The anodes 17 through 17J have generally been described as being constructed of a titanium group metal with the walls 61 - 61J and 62 - 62J being solid plates and the titanium plates being platinized on the side adjacent the cathode fingers 47 - 47J. The anodes 17 - 17J may alterna-tively have side walls constructed of a pervious, anodically-resistant plate, for example, of rod material, screen, ex-panded metal mesh, perforated plate, or louvered plate. The pervious plate may be of titanium metal. Preferably, the pervious titanium plate has en electroconductive surface, for example, of platinum, only on the side remote from the cathode fingers. By so doing, the titanium metal forms a non-conductive titanium oxide coating adjacent the diaphragm and gas evolution during cell operation takes place on the back side of the side walls, thus substantially reducing gas blinding and turbulence in the diaphragm. Furthermore, the side of the cathode back screen and cathode fingers toward the anode may be electrically insulated such as with a rubber coating. By so doing, the cathodic gas products would be produced on tbe back side of the cathode which would further 1131~
reduce gas blinding and back migration of caustic soda. This arrangement would provide a highly-efficient cell, particularly if the porosity of the diaphragm is slightly increased and the cell is operated at a high brine flow rate and a high current density such as in excess of 150, preferably in excess of 200, amperes per square foot of cathode surface, as defined by length and breadth measurements of the cathode.
The cell of the present invention, especially when using wedge-shaped foraminous anodes and cathodes, operates in a very efficient manner when the anode-to-cathode gap is near zero, for example, generally less than 1/2 inch, typi-cally, 1/8 to 1/4 inch and, preferably, the anode is directly against the diaphragm.
Although the present invention has been described with reference to specific details of particular embodiments thereof, it is not intended thereby to limit the scope of the invention except insofar as the specific details are recited in the appended claims. For example, one skilled in the art may replace the non-woven asbestos fabric with a permionic membrane.
Claims (42)
1. An improved bipolar diaphragm-type cell for the electrolytic production of chlorine and caustic soda by decomposition of an alkali-halide brine, which cell includes a plurality of single cells connected in series, said single cells including anode means, metal screen cathode means, and diaphragm means covering said cathode, said diaphragm means dividing the single cell into an anodic compartment and a cathodic compartment, said single cells being comprised of a pair of adjacent cell units, said cell units comprising an electrode support plate which serves as a partition between a pair of adjacent single cells, said support plate providing a pair of faces, a plurality of elongated hollow, finger-like cathodes, with vertically disposed surfaces which serve as the cathode means for one member of said pair of adjacent single cells extending outwardly from one face of said support plate, a plurality of elongated finger-like hollow anodes having a pair of spaced vertically disposed walls of a chlorine resistant metal with an anodically-resistant electroconductive surface extending outwardly from the other face of said support plate which serve as the anode means for the other member of said pair of adjacent single cells, means for securing the base of said finger-like cathodes and the base of said finger-like anodes to said electrode support plate in an aligned arrangement whereby an electrical charge is capable of traveling through the support plate between cathodes and anodes mounted on the opposed faces of the same support plate and means electrical-ly connecting the anodes and cathodes through the support plate of the cell unit.
2. The cell defined in claim 1 wherein said anode and cathode arrangement is such that an electrical charge is capable of travelling in a straight line from the base of an anode to the base of a cathode mounted on the same support plate.
3. The cell defined in claim 1 wherein said finger-like cathodes and said finger-like anodes are hollow and wedge-shaped, the thin edges of said wedge-shaped anodes and cathodes are spaced from and parallel with said electrode support plate, and wherein the angle formed by said anode wedge of one cell unit is complementary with the angle formed between a pair of cathode wedges of the adjacent cell unit whereby the vertically disposed surfaces of said anode wedge are parallel with the opposing vertical-ly disposed surfaces of said cathode wedges.
4. The cell defined in claim 1 wherein said anodes have foraminous side walls and wherein the space between the vertically disposed faces of said anodes and said cathodes of a single cell is less than 1/2 inch.
5. The cell of claim 4 wherein said space is between 1/8 and 1/4 inch.
6. The cell of claim 4 wherein the anode is in contact with said diaphragm.
7. The cell of claim 4 wherein the sides of said anodes and cathodes adjacent said diaphragm are electrically non-conductive and wherein the sides of said anodes and cathodes remote from said diaphragm are electrically conductive.
8. The cell defined in claim 1 wherein an electrode securing means is provided for electrically interconnecting said one finger-like cathode and said one finger-like anode said electrode securing means com-prising current gathering means, electrically connected to said cathode, and means for electrically connecting said anode to said current gathering means.
9. The cell defined in claim 8 wherein screw means are provided for connecting said anode to said current gathering means.
10. The cell defined in claim 9 wherein the edge of said finger-like anode remote from the base of said anode has defined therein an opening providing access to said screw means for mounting and removal of said one pair of electrodes.
11. The cell defined in claim 10 wherein current gathering means comprises bar means attached to said cathode and wherein said means for electrically connecting said anode to said current gathering means comprises an electroconductive block one surface of which contacts said bar means and another surface of which contacts the base of one of said finger-like anodes.
12. The cell defined in claim 11 wherein screw means extend through the base of said anode, support said anode with respect to said electrode support plate, and hold the base of said anode in electrical contact with said block.
13. The cell defined in claim 12 wherein said block extends beyond the edge of the electrode support plate on the side adjacent the anode, wherein a seal is disposed between the base of the anode and the electrode support means and wherein said screw means compresses said seal, thereby providing a fluid tight seal between the anode side and the cathode side of said electrode support plate.
14. The cell defined in claim 1 wherein said finger-like cathode and said finger-like anodes are hollow and wedge shaped and wherein the thin edges of said wedge-shaped anodes and cathodes are perpendicular to said electrode support plate.
15. The cell of claim 14 wherein said cell includes a backscreen disposed between said cathodes and said electrode support plate, said back-screen being in spaced relationship with said support plate, thereby defining a gas collection zone therebetween, and wherein said wedge-shaped cathodes have upwardly-converging side walls and baffle means disposed between said side walls for urging cathode product gases from said wedges into said gas collection zone.
16. The cell of claim 1 wherein the pair of spaced walls of said anodes have stiffening means.
17. A diaphragm-type electrolytic cell for the production of chlorine and caustic soda by electrolyzing alkali halide brine which cell includes a housing containing a plurality of single cells connected electrical-ly in series within the housing, a plurality of said single cells including:
a pair of spaced backplates within the housing which physically separate such single cell from other adjacent cells within the housing; cathode means comprising a plurality of elongated hollow cathodic finger mem-bers extending outwardly from one of said backplates toward the other backplate of the pair; anode means comprising a plurality of hollow anode elements extending outwardly from the said other backplate toward the first backplate and intermeshing with said cathode members; and diaphragm means covering said cathodes divid-ing the single cell into an anodic and cathodic compartment; said hollow anode elements comprising a pair of spaced walls of chlorine resistant metal having an anodically-resistant electroconductive surface, each such wall having an outer surface facing the opposed cathodic surface of the adjacent cathodic finger members with which the anode intermeshes; and means for passing current through each of said backplates to electrodes which extend outwardly from the face thereof into an adjacent cell.
a pair of spaced backplates within the housing which physically separate such single cell from other adjacent cells within the housing; cathode means comprising a plurality of elongated hollow cathodic finger mem-bers extending outwardly from one of said backplates toward the other backplate of the pair; anode means comprising a plurality of hollow anode elements extending outwardly from the said other backplate toward the first backplate and intermeshing with said cathode members; and diaphragm means covering said cathodes divid-ing the single cell into an anodic and cathodic compartment; said hollow anode elements comprising a pair of spaced walls of chlorine resistant metal having an anodically-resistant electroconductive surface, each such wall having an outer surface facing the opposed cathodic surface of the adjacent cathodic finger members with which the anode intermeshes; and means for passing current through each of said backplates to electrodes which extend outwardly from the face thereof into an adjacent cell.
18. The cell of claim 17 wherein the walls are pervious.
19. The cell of claim 17 wherein the walls are of expanded anodically-resistant metal mesh having an electroconductive surface.
20. The cell of Claim 17 wherein the outer surfaces of said anodic walls are at an angle complementary to the angle provided between the pair of adjacent cathodic finger members into which the walls intermesh.
21. The cell of Claim 2 0 wherein the anode elements and cathode members are wedge-shaped.
22. The cell of claim 20 wherein the space between the surfaces of the anodic walls and the opposed cathodic elements is less than 1/2 inch.
23. A bipolar diaphragm cell for producing chlorine and caustic soda by electrolyzing alkali halide brine which cell includes a cell housing containing at least one intermediate cell, said intermediate cell comprising a pair of a substantially parallel spaced backplates vertically disposed within the cell housing partitioning the cell from other cells within the housing;
cathode means comprising finger-like elements electrically connected to and extending outwardly from a first backplate of the pair toward the other backplate and primarily being disposed in a vertical plane perpendicular to said backplate; diaphragm means covering said cathodes dividing the inter-mediate cell into anodic and a cathodic compartment; anode means compris-ing hollow anodic elements extending outwardly from said second backplate toward the first backplate and intermeshing with cathode finger-like elements extending from the first backplate, said anodic elements including a pair of laterally-spaced vertical walls of a chlorine resistant metal having an anodical-ly-resistant electroconductive surface disposed between and spaced from the opposed surfaces of adjacent cathode fingers, said hollow interior of the anode elements being in liquid communication with and being part of the anodic compartment; and means for passing current through each backplate of said pair from the electrodes mounted on one face of the backplate to electrodes mounted on the other face thereof.
cathode means comprising finger-like elements electrically connected to and extending outwardly from a first backplate of the pair toward the other backplate and primarily being disposed in a vertical plane perpendicular to said backplate; diaphragm means covering said cathodes dividing the inter-mediate cell into anodic and a cathodic compartment; anode means compris-ing hollow anodic elements extending outwardly from said second backplate toward the first backplate and intermeshing with cathode finger-like elements extending from the first backplate, said anodic elements including a pair of laterally-spaced vertical walls of a chlorine resistant metal having an anodical-ly-resistant electroconductive surface disposed between and spaced from the opposed surfaces of adjacent cathode fingers, said hollow interior of the anode elements being in liquid communication with and being part of the anodic compartment; and means for passing current through each backplate of said pair from the electrodes mounted on one face of the backplate to electrodes mounted on the other face thereof.
24. The cell of claim 23 wherein the walls are of a pervious metal plate.
25. The cell of claim 24 wherein the pervious plate is expanded metal mesh.
26. In the production of chlorine and caustic soda by electrolysis of an alkali halide brine in a diaphragm cell which includes anodes, finger-like cathodes and diaphragm means, the improvement which comprises conducting said brine electrolysis and producing chlorine and caustic soda utilizing hollow anodes having a pair of spaced walls of chlorine resistant metal with an electroconductive surface of a platinum group metal or oxide of a platinum group metal wherein said surfaces are disposed between and face opposed cathodic surfaces of an adjacent pair of the finger-like cathodes and the hollow space between the anode walls contains brine and is in liquid communication with brine within the cell.
27. A method of operating a bipolar electrolyzer having a plurality of individual bipolar units in back-to-back bipolar configuration, with a peripheral wall around each individual bipolar unit; an anolyte chamber and a catholyte chamber in each individual bipolar unit, the anolyte chamber and catholyte chamber of an individual bipolar unit being separated from each other by a backplate having a surface of a ferrous metal on the catholyte side and titanium on the anolyte side; a plurality of hollow, wedge-shaped, inward and upward louvered, valve metal anodes in said anolyte chamber, said valve metal anodes having an electrically conductive surface thereon; valve metal conductors between the base of said valve metal anode wedges and the titanium surface of said backplate; the bases of said hollow, wedge-shaped, inward and upward louvered, valve metal anodes being held securely against said valve metal conductors; a plurality of hollow, wedge-shaped, metal cathodes in said catholyte chamber; said hollow, wedge-shaped metal cathodes being spaced from and electrically connected to the ferrous metal surface of said backplate; the hollow, wedge-shaped, valve metal anodes of one bipolar unit and the hollow, wedge-shaped cathodes of the next adjacent bipolar unit being interleaved between and uniformly spaced from each other and forming a single electrolytic cell therebetween; and a diaphragm therebetween dividing said single electrolytic cell into an anolyte chamber and a catholyte chamber; which method comprises feeding sodium chloride brine into each of the individual electrolytic cells;
passing an electrical current through the electrolyzer from the cathodes of one cell through the backplate to the anodes of the next adjacent cell in the electrolyzer; evolving chlorine in the anolyte chamber; collecting the evolved chlorine within the hollow, wedge-shaped anodes between the inward and upward louvered metal walls thereof, thereby imparting an up-ward circulatory motion to anolyte liquid within the hollow, wedge-shaped anodes; recovering said chlorine at the top of said anolyte chamber;
evolving hydrogen and caustic soda in said catholyte chamber; recovering said hydrogen at the top of said catholyte chamber; and recovering catholyte liquor from said catholyte chamber.
passing an electrical current through the electrolyzer from the cathodes of one cell through the backplate to the anodes of the next adjacent cell in the electrolyzer; evolving chlorine in the anolyte chamber; collecting the evolved chlorine within the hollow, wedge-shaped anodes between the inward and upward louvered metal walls thereof, thereby imparting an up-ward circulatory motion to anolyte liquid within the hollow, wedge-shaped anodes; recovering said chlorine at the top of said anolyte chamber;
evolving hydrogen and caustic soda in said catholyte chamber; recovering said hydrogen at the top of said catholyte chamber; and recovering catholyte liquor from said catholyte chamber.
28. The method of operating a bipolar electrolyzer of Claim 27 wherein said hollow, wedge-shaped, inward and upward louvered, valve metal anodes have an electrically conductive surface only on the interior surfaces thereof and wherein chlorine is evolved only within the hollow, wedge-shaped anodes.
29. The method of operating a bipolar electrolyzer of Claim 27 comprising passing the electrical current from a cathode of one cell through an electrode support means which extends through an opening in the backplate, to an anode mounting means of the next adjacent cell of the electrolyzer, and from the anode mounting means to an anode mounted thereon.
30. The method of operating a bipolar electrolyzer of Claim 27 comprising collecting the evolved hydrogen gas in a chamber in the upper portion of the bipolar unit and recovering catholyte liquor from a separate chamber in the lower portion of the bipolar unit.
31. A method of operating a bipolar electrolyzer having a plurality of individual bipolar units in back-to-back bipolar configuration, with a peripheral wall around each individual bipolar unit; an anolyte cham-ber and a catholyte chamber in each individual bipolar unit, the anolyte chamber and catholyte chamber of an individual bipolar unit being separated from each other by a backplate having a surface of a ferrous metal on the catholyte side and titanium on the anolyte side; a plurality of hollow, wedge-shaped, inward and upward louvered, titanium anodes in said anolyte chamber, said titanium anodes having an electrically conductive surface only on the interior surfaces thereof; titanium conductors between the base of said hollow, wedge-shaped, titanium anodes and the titanium surface of said backplate; the bases of said hollow, wedge-shaped, inward and up-ward louvered, titanium anodes being held securely against said titanium conductors; a plurality of hollow, wedge-shaped, metal cathodes in said catholyte chamber; said hollow, wedge-shaped metal cathodes being spaced from and electrically connected to the ferrous metal surface of said back-plate; the hollow, wedge-shaped, titanium anodes of one bipolar unit and the hollow, wedge-shaped cathodes of the next adjacent bipolar unit being interleaved between and uniformly spaced from each other and forming a single electrolytic cell therebetween; and a diaphragm therebetween dividing said single electrolytic cell into an anolyte chamber and a catholyte chamber; which method comprises feeding sodium chloride brine into each of said individual electrolytic cells; passing an electrical current through said electrolyzer from the cathodes of one cell through the back-plate to the anodes of the next adjacent cell in the electrolyzer; evolving and collecting chlorine within the hollow, wedge-shaped anodes between the inward and upward louvered walls thereof, thereby imparting an upward circu-latory motion to anolyte liquor within the anode wedges; recovering said chlorine at the top of the anolyte chamber; evolving hydrogen and caustic soda in the catholyte chamber; recovering said hydrogen at the top of the catholyte chamber; and recovering catholyte liquor from the catholyte chamber.
32. The method of operating a bipolar electrolyzer of Claim 31 comprising passing the electrical current from a cathode of one cell through an electrode support means which extends through an opening in the backplate, to an anode mounting means in the next adjacent cell, and from the anode mounting means to an anode mounted thereon.
33. The method of operating a bipolar electrolyzer of Claim 31 comprising collecting the evolved hydrogen gas in a chamber in the upper portion of the bipolar unit and recovering catholyte liquor from a separate chamber in the lower portion of the bipolar unit.
34. A method of operating a bipolar electrolyzer having a plurality of individual bipolar units in back-to-back bipolar configuration, with a peripheral wall around each individual bipolar unit; an anolyte chamber and a catholyte chamber in each individual bipolar unit, the anolyte chamber and catholyte chamber of an individual bipolar unit being separated from each other by a backplate having a surface of a ferrous metal on the catholyte side and titanium on the anolyte side; a plurality of hollow, wedge-shaped, inward and upward louvered, valve metal anodes in said anolyte chamber, said valve metal anodes having an electrically conductive surface only on the interior surfaces thereof; valve metal conductors between the base of said hollow, wedge-shaped, valve metal anodes, and the valve metal surface of said backplate; the bases of said hollow, wedge-shaped, inward and upward louvered, valve metal anodes being held securely against said valve metal conductors; a plurality of hollow, wedge-shaped, metal cathodes in said catholyte chamber; said hollow, wedge-shaped, metal cathodes being spaced from and electrically connected to the ferrous metal surface of said backplate; the hollow, wedge-shaped, valve metal anodes of one bipolar unit and the hollow, wedge-shaped cathodes of the next adjacent bipolar unit being interleaved between and uniformly spaced from each other and forming a single electrolytic cell therebetween; and a diaphragm therebetween dividing said single electrolytic cell into an anolyte chamber and a catholyte chamber;
which method comprises feeding sodium chloride brine into each of said individual electrolytic cells; passing an electrical current through said electrolyzer from the cathode of one cell through an electrode support means which extends through an opening in the backplate, to an anode mounting means, in the next adjacent cell, and from the anode mounting means to an anode mounted thereon; evolving and collecting chlorine within the hollow, wedge-shaped, valve metal anodes between the inward and upward louvered walls there-of, thereby imparting an upward circulatory motion to the anolyte liquor within the hollow, wedge-shaped anodes; recovering said chlorine at the top of said anolyte chamber; evolving hydrogen and caustic soda in said catholyte chamber; collecting the evolved hydrogen gas in a chamber in the upper por-tion of the bipolar unit and recovering the hydrogen gas therefrom; and re-covering catholyte liquor from a separate chamber in the lower portion of the bipolar unit.
which method comprises feeding sodium chloride brine into each of said individual electrolytic cells; passing an electrical current through said electrolyzer from the cathode of one cell through an electrode support means which extends through an opening in the backplate, to an anode mounting means, in the next adjacent cell, and from the anode mounting means to an anode mounted thereon; evolving and collecting chlorine within the hollow, wedge-shaped, valve metal anodes between the inward and upward louvered walls there-of, thereby imparting an upward circulatory motion to the anolyte liquor within the hollow, wedge-shaped anodes; recovering said chlorine at the top of said anolyte chamber; evolving hydrogen and caustic soda in said catholyte chamber; collecting the evolved hydrogen gas in a chamber in the upper por-tion of the bipolar unit and recovering the hydrogen gas therefrom; and re-covering catholyte liquor from a separate chamber in the lower portion of the bipolar unit.
35. A method of operating a bipolar electrolyzer having a plurality of individual bipolar units in back-to-back bipolar configuration, with a peripheral wall around each individual bipolar unit; an anolyte chamber and a catholyte chamber in each individual bipolar unit, the anolyte chamber and catholyte chamber of an individual bipolar unit being separated from each other by a backplate having a surface of a ferrous metal on the catholyte side and titanium on the anolyte side; said bipolar unit having a chamber for the collection of gases in the upper portion thereof, in communication with the catholyte side of the backplate, and a separate chamber for the collection of liquid in the lower portion thereof in communication with the catholyte side of the backplate; a plurality of hollow, wedge-shaped, inward and upward louvered, titanium anodes in said anolyte chamber, said titanium anodes having an electrically conductive surface only on the interior surfaces thereof; internally threaded titanium conductors between the base of said titanium anode wedges and the titanium surface of said backplate; the bases of said hollow, inward and upward louvered, titanium anode wedges being held securely against said titanium conductors by a threaded, titanium screw; a plurality of hollow, wedge-shaped, ferrous metal cathodes in said catholyte chamber; said hollow, wedge-shaped ferrous metal cathodes being spaced from and electrically connected to the ferrous metal surface of said backplate; the hollow, wedge-shaped, titanium anodes of one bipolar unit and the hollow, wedge-shaped cathodes of the next adjacent bipolar unit being interleaved between and uniformly spaced from each other and forming a single electrolytic cell there-between; and an asbestos diaphragm on said hollow, wedge-shaped cathodes dividing said single electrolytic cell into an anolyte chamber and a catholyte chamber; which method comprises continuously feeding sodium chloride brine into each of said individual electrolytic cells; passing an electrical current through said electrolyzer from the cathode of one cell through an electrode support means which extends through an opening in the backplate, to an anode mounting means, and from the anode mounting means to an anode of the next adjacent cell in the electrolyzer; evolving and collecting chlorine within the hollow, wedge-shaped, anodes between the inward and upward louvered walls thereof, thereby imparting an upward circulatory motion to anolyte liquor within the hollow, wedge-shaped anodes;
recovering said chlorine at the top of said anolyte chamber; evolving hydrogen and caustic soda in said catholyte chamber; collecting the evolved hydrogen gas in the chamber in the upper portion of the bipolar unit;
continuously recovering chlorine from said chamber, and recovering catholyte liquor from the separate chamber in the lower portion of the bipolar unit.
recovering said chlorine at the top of said anolyte chamber; evolving hydrogen and caustic soda in said catholyte chamber; collecting the evolved hydrogen gas in the chamber in the upper portion of the bipolar unit;
continuously recovering chlorine from said chamber, and recovering catholyte liquor from the separate chamber in the lower portion of the bipolar unit.
36. A method of operating a bipolar electrolyzer having a plurality of individual bipolar diaphragm cells electrically and mechanically in series, each of said individual cells having a first backplate with a ferrous surface and a second backplate with a titanium clad surface whereby the ferrous surface is in back-to-back bipolar configuration with a titanium surface of the next adjacent cell in the electrolyzer and the titanium surface is in back-to-back bipolar configuration with a ferrous surface of the prior adjacent cell in the electrolyzer; said individual bipolar diaphragm cell being divided into an anolyte chamber and a catholyte chamber by a diaphragm; a plurality of hollow titanium anodes in said anolyte chamber, each of said anodes being formed of a pair of spaced, vertically disposed foraminous walls, said titanium anodes having an electroconductive surface only on the interior surfaces thereof; valve metal conductors between the base of said hollow titanium anodes and the titanium surface of said backplate; the bases of said hollow titanium anodes being held securely against said conductors by bolt means passing from said anodes through said conductors and backplate to bases of cathodes of the next adjacent cell in the electrolyzer; a plurality of hollow metal cathodes in said catholyte chamber; said hollow metal cathodes being spaced from and electrically connected to the ferrous metal surface of said backplate; the hollow titanium anodes and the hollow cathodes being interleaved between and uniformly spaced from each other and forming a single electrolytic cell therebetween; which method comprises feeding sodium chloride brine into each of said individual electrolytic cells; passing an electrical current through said electrolyzer from the second back-plate of one cell through the anodes of said cell to the cathodes of said cell to the first backplate of said cell and from the said first backplate to the anodes of the next adjacent cell in the electrolyzer; evolving chlorine on the interior surfaces of said anodes and collecting said chlorine within the hollow anodes between the walls thereof and the titanium backplate; recovering said chlorine at the top of the anolyte chamber; evolving hydrogen and caustic soda in the catholyte chamber; recovering said hydrogen at the top of the catholyte chamber; and recovering catholyte liquor including said caustic soda from the catholyte chamber.
37. An electrolytic cell having at least two cell units, each unit comprising a valve metal anode coated with a con-ducting electrocatalytic material, and a ferrous metal cathode each of which is formed with a series of fingers, the anode fingers nesting with the cathode fingers so that there is a substantially uniform spacing between the anode and cathode surfaces, the cathode surfaces being in the form of a screen means for supplying an electrolyte to the unit, means for passing an electrolytic current through the electrolyte from the anode to the cathode, and means for discharging anodic products and cathodic products from the cell unit, the cathode of one unit cell being separated from the anode of the adjacent unit cell by a continuous bimetallic separating partition of ferrous metal on the cathode side and valve metal on the anode side, the cathode fingers being connected to the ferrous metal side and the anode fingers being connected to the valve metal side of said partition.
38. A cell according to claim 37, in which the cathode is provided with a diaphragm cover.
39. A cell according to claim 38, in which the cathode fingers have an openwork structure.
40. A cell according to claim 37, in which the cathodes are made of steel and the valve metal anodes are made of titanium.
41. An electrode assembly comprising a two-sided base plate formed as a lamination of a layer of titanium and a layer of iron intimately joined together and a number of parallel titanium and iron electrode plates projecting outwardly from opposite sides of said base plate at essentially right angles, said titanium electrode plates being coated with conduct-ing material, said electrode plates being formed of the same metal material as the side of said base plate from which said electrode plates project, so that each titanium anode projects from the titanium side of the base plate and each iron cathode projects from the iron side of said base plate.
42. An electrode assembly comprising a two-sided base plate formed as a lamination of a layer of titanium and a layer of iron intimately joined together and a number of parallel electrode plates projecting outwardly from opposite sides of said base plate at essentially right angles, said electrode plates being formed of iron and of titanium coated with conductive material, said electrode plates being formed of the same metal material as the side of said base plate from which said electrode plates project, so that each titanium anode projects from the titanium side of the base plate and each iron cathode projects from the iron side of said base plate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA140,624A CA1131584A (en) | 1969-06-24 | 1972-04-26 | Diaphragm cell |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US83608269A | 1969-06-24 | 1969-06-24 | |
| US836,082 | 1969-06-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1131170A true CA1131170A (en) | 1982-09-07 |
Family
ID=25271193
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA086,271A Expired CA1131170A (en) | 1969-06-24 | 1970-06-23 | Diaphragm cell |
Country Status (12)
| Country | Link |
|---|---|
| JP (1) | JPS4840560B1 (en) |
| BE (1) | BE752380A (en) |
| BR (1) | BR7019912D0 (en) |
| CA (1) | CA1131170A (en) |
| DE (1) | DE2030610B2 (en) |
| ES (1) | ES381063A1 (en) |
| FR (1) | FR2051216A5 (en) |
| GB (1) | GB1321109A (en) |
| NL (1) | NL164097C (en) |
| NO (1) | NO137946C (en) |
| SE (1) | SE370025B (en) |
| ZA (1) | ZA703723B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE793045A (en) * | 1971-12-21 | 1973-06-20 | Rhone Progil | BIPOLAR ELECTRODES |
| JPS5647267B2 (en) * | 1973-03-13 | 1981-11-09 | ||
| US3876517A (en) * | 1973-07-20 | 1975-04-08 | Ppg Industries Inc | Reduction of crevice corrosion in bipolar chlorine diaphragm cells by locating the cathode screen at the crevice and maintaining the titanium within the crevice anodic |
| US4013525A (en) | 1973-09-24 | 1977-03-22 | Imperial Chemical Industries Limited | Electrolytic cells |
| IT1049943B (en) * | 1975-11-28 | 1981-02-10 | Oronzio De Nora Impianti | ELECTROLYSIS CELL WITH VERTICAL ANODES AND CATHODES AND METHOD OF OPERATION |
| EP2459775B1 (en) * | 2009-07-28 | 2018-09-05 | Alcoa USA Corp. | Composition for making wettable cathode in aluminum smelting |
| DE102014204142B4 (en) | 2014-03-06 | 2016-05-25 | Hans-Jürgen Dörfer | Process for the preparation of aqueous chlorine dioxide solutions and use of an apparatus for carrying out the process |
-
1970
- 1970-06-02 ZA ZA703723A patent/ZA703723B/en unknown
- 1970-06-12 SE SE08226/70A patent/SE370025B/xx unknown
- 1970-06-22 DE DE19702030610 patent/DE2030610B2/en not_active Ceased
- 1970-06-23 FR FR7023151A patent/FR2051216A5/fr not_active Expired
- 1970-06-23 BE BE752380D patent/BE752380A/en not_active IP Right Cessation
- 1970-06-23 CA CA086,271A patent/CA1131170A/en not_active Expired
- 1970-06-23 GB GB3030170A patent/GB1321109A/en not_active Expired
- 1970-06-23 ES ES381063A patent/ES381063A1/en not_active Expired
- 1970-06-23 NO NO2429/70A patent/NO137946C/en unknown
- 1970-06-23 NL NL7009176.A patent/NL164097C/en not_active IP Right Cessation
- 1970-06-24 JP JP45055089A patent/JPS4840560B1/ja active Pending
- 1970-06-24 BR BR219912/70A patent/BR7019912D0/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| GB1321109A (en) | 1973-06-20 |
| FR2051216A5 (en) | 1971-04-02 |
| NL164097C (en) | 1980-11-17 |
| DE2030610B2 (en) | 1976-06-24 |
| JPS4840560B1 (en) | 1973-12-01 |
| BE752380A (en) | 1970-12-23 |
| DE2030610A1 (en) | 1971-01-14 |
| SE370025B (en) | 1974-09-30 |
| ES381063A1 (en) | 1972-11-01 |
| NL7009176A (en) | 1970-12-29 |
| NO137946C (en) | 1978-05-24 |
| NL164097B (en) | 1980-06-16 |
| ZA703723B (en) | 1972-01-26 |
| BR7019912D0 (en) | 1973-04-17 |
| NO137946B (en) | 1978-02-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| FI71356C (en) | ELEKTRODSTRUKTUR FOER ANVAENDNING I ELEKTROLYTISK CELL | |
| US4643818A (en) | Multi-cell electrolyzer | |
| US4013525A (en) | Electrolytic cells | |
| US4217199A (en) | Electrolytic cell | |
| CA1107685A (en) | Diaphragm cell | |
| US3910827A (en) | Diaphragm cell | |
| US3930981A (en) | Bipolar electrolysis cells with perforate metal anodes and baffles to deflect anodic gases away from the interelectrodic gap | |
| US3755105A (en) | Vacuum electrical contacts for use in electrolytic cells | |
| US4402810A (en) | Bipolarly connected electrolytic cells of the filter press type | |
| CA1095855A (en) | Electrolytic cell having membrane enclosed anodes | |
| GB1529737A (en) | Diaphragm cell having uniform and minimum spacing between anodes and cathodes | |
| CA1131170A (en) | Diaphragm cell | |
| US3976550A (en) | Horizontal, planar, bipolar diaphragm cells | |
| US3856651A (en) | Apparatus for producing uniform anolyte heads in the individual cells of a bipolar electrolyzer | |
| CA1040135A (en) | Electrolytic diaphragm cell | |
| US4032423A (en) | Method of assembling a bipolar electrolyzer | |
| US4096054A (en) | Riserless flexible electrode assembly | |
| CA1154718A (en) | Electrode for monopolar filter press cells | |
| US4851099A (en) | Electrolytic cell | |
| US4236989A (en) | Electrolytic cell | |
| US3975255A (en) | Inter-electrode spacing in diaphragm cells | |
| CA1131584A (en) | Diaphragm cell | |
| CA1048966A (en) | Electrode assembly for an electrolytic cell | |
| CA2225410C (en) | Diaphragm element for an electrolytic filter press assembly | |
| PL148626B1 (en) | Electrolyzer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |