US3928167A - Improvements in methods of producing electrolytic anode assemblies - Google Patents

Abstract

Methods are provided of producing electrolytic diaphragm cells are provided comprising a plurality of vertical substantially flat and hollow anodes formed, as regards at least one of their two substantially parallel faces, by a sheet of a film-forming metal, said anodes being secured to the base of the cell by means of extended portions which pass through the base, characterized in that the extended portions comprise a core made of a metal which is a good electrical conductor, which core is covered by a sheath made of a film-forming metal, a good electrical contact being ensured between the sheath and the core.

Description

Umted States Patent 1 1111 3,928,167

Buoy et al. Dec. 23, 1975 IMPROVEMENTS IN METHODS OF [56] References Cited PRODUCING ELECTROLYTIC ANODE UNITED STATES PATENTS ASSEMBLIES 1,955,728 4/1934 Allen et al. 29/441 [75] Inventors: Pierre Buoy, Enghien-les-Bains; 2,092,353 9/ 1937 29/508 D i l Masure, La Madeleine; Paul 1;; 92/3/7404:

c a an E2322 rgggiz f igxg g 3,591,483 7/1971 Loftfield et al. 204/252 9 9 3 Levallois-Perret, all of France Primary Examiner R. L Andrews [73] Assignee: Rhone-Progil, Paris, France 22 Filed: May 15, 1974 [57] ABSTRACT Methods are provided of producing electrolytic dia [21] Appl 470167' phragm cells are provided comprising a plurality of Related US. A li ati D t vertical substantially flat and hollow anodes formed, [62] Division of S No 316 515 D e c 19 1972 as regards at least one of their two substantially parallel faces, by a sheet of a film-formin metal, said and b d h b f h g 1] b f 30 Forei A 5 ti D ta 0 es emg secure tot e aseo t ece ymeanso 1 D 23 1 ca on lonty a 46296 extended portions which pass through the base, charec. rance acterized in the extended portions comprise a core made of a metal which is a good electrical con- 8 204/286 ductor, which core is covered by a sheath made of a [58] Fie'ld 290 R film-forming metal, a good electrical contact being en- 204/286 sured between-the :sheath and the core.

2 Claims, 4 Drawing Figures IIII/IIIIIIIA US. Patent Dec. 23, 1975 Sheet10f2 3,928,167

U.S. Patent Dec. 23, 1975 Sheet 2 of2 3,928,167

IMPROVEMENTS IN METHODS OF PRODUCING ELECTROLYTIC ANODE ASSEMBLIES This application is a division of our copending application, Ser. No. 316,515, filed Dec. 19, 1972.

, BACKGROUND OF THE INVENTION .The present invention relates to electrolytic diaphragm cells provided with flat and hollow-metal anodes which are formed, at least as regards one of their two parallel faces, by an apertured sheet or a lattice made of titanium or a metal or alloy having similar anodic properties. The anodes are also provided with extended portions for the inputof electric current and for fixing the anodes to the bases of the cells.

The advantages are known of using titanium or metals or alloys having similar properties instead of graphite anodes in electrolytic cells, with such anodes being covered with a conducting metal which is not attacked by the electrolytic solutions. In particular, French Pat, No. 1600249 describes constructions in which such metal anodes are extended by metal portions for secur-. ing them to the base of the cells, and for the input of the electrical current. 1

It is an object of the present invention to provid processes of producing electrolytic diaphragm cells having improved anodes.

It is also an object of the present invention to provide electrolytic diaphragm cells having anodes which permit a more favorable distribution of electrical current.

These and other objects will be apparent to those skilledin the art from the present description, taken in conjunction with the. appended drawings, in which:

' FIG. 1 is an elevational view of an anode of the invention.

FIG. 2 is an elevational view of the lower part of the anode of FIG. 1 having an extended portion fastened to the base of a cell.

FIG. 3 is aneelevational view of anotheranode extended portion fastened to the base of a cell.

FIG. 4 is an elevational view of the lower part of an anode extended portion fastened to the base of the cell,

with the electrical connection to the core portion.

GENERAL DESCRIPTION OF THE INVENTION The improved constructionsnow described of the present inventionuse extended portions comprising a core made of a material which is a good electrical concluctor, thecore being covered with a sheath of titanium or other film-forming metal or alloy having similar anodic properties, so that a perfect electrical connection is ensured between the'sheat'h and the core.

and can be welded to the faces of the anodes in such a way thatthe most favourable distributionof the electrical current is ensured at that point. i

In practice, depending on the dimensions of the an odes and their electrical characteristics, one or more of such extended portions is used per anode, the use of a single extended portion enjoying 'the advantage, however, that it is notsubjeeted to forces due to expansion of the elements of the anode. Extended portions of this nature are preferably made'from jointly drawn members which are cylindrical in shape. It is easy to see that such a cylindrical shape permits various machining operations for ensuring a current feed to the extended portions. V i

A first way in which electrical current can be supplied comprises exposing the conducting core of the extended portion at its lower end which passes through the base of the cell. This permits securing to the core in various known manners the current supply leads. It also provides for a screw-thread on the sheath where it passes through the base, and securing thereto by weld ing above the screw-th'read'a washer of the same or a similar metal, and thus to'tighten the extended portions to the cell base. Also provided is sealing by means of a sealing gasket, which is preferably toric or toroidal, interposed between the washer and the base. The current supplyleads can be securedto the base of the cell and, if the base is metal, they can then act as a general current input for the anodes.

Another way in which the electrical current can be supplied to the extended portions of the anode in the case'where the base of the cell is of metal, comprises gripping the conducting core of the extended'portions of the anode, which is bared or exposed where it passes through the'base of the cell, by the metal of which the base itself is made. This gripping effect can be achieved by simply making the core have a force or frictional fit in the base. However, it is preferably achieved by shrink-fitting, by establishing before assembly a sufficient temperature difference between the base and the extended portions of the anode, for example, by immersing the latter in liquid nitrogen before fitting. Upon expansion where returning to atmospheric or elevated temperature, alight fit is possible. Dismantling, if required, can be effected by various means which can be used in combination, and which can include 1 screw extractors, (2) by providing the various anchorages required, (3) conical machining of the core of the extended portions, (4) passages provided in the core so that a cooling fluid can be circulated therein, and (5) means for heating'the base. In this second way of feeding the electrode with current, it is obvious that sealing can be effected in a similar manner to that described above, by squashing, when the anodes are assembled, a sealing gasket comprising a suitable elastomer, precisely by the amount required, between a washer secured to the extended portions and the base of the cell. Also, this may be accomplished by clamping the joint after assembly-againstthe base by means of a washer which isscrewed on to "the sheath of the extended portions. Itis also possible to effect sealing by welding on by means of their edges thin pieces of titanium or other film-forming metal, replacing the washers used' hereinbefore, for protectin the base of the cell with titanium. A third Way in which the current sup lyean beprovided, comprises using a conducting" metal for making the base of the cell and making a connection between the base and the extended portions by means of resilient contacts arranged in an annular spacefprov'lded between the conducting core of the extended portions, which core is bared Where it passes through the base,

and the aperture through which it passes through the.

base, sealing being effected in the same manner as hereinbefore, by means of sealing gaskets.

SPECIFIC DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described by way of example hereinafter with reference to the accompanying drawings.

FIG. 1 shows an elevational view of an anode according to the invention comprising two expanded or apertured sheets 1 of titanium or other film-forming metal, such as tantalum, tungsten, zurconium, etc. These are welded along their vertical axes to the titanium sheath of a cylindrical jointly-drawn member 2 comprising copper and titanium. The titanium sheets 1 may be in the form of a lattice. Threaded on to and welded to the lower part of the member 2 is a washer 3 comprising titanium or other film-forming metal, which, by way of the toric sealing gasket 4, provides for sealing with respect to the polyester base 5 of the electrolytic cell. The titanium sheath of the part of the member 2 which is located below the washer 3 is screw-threaded so that the anode can be tightened to the baseof the cell by means of a nut 6. The copper core 7 of the lower end of the member 2 is bared or exposed and carries a sleeve 8 connected by a bunch 9 of copper wires to the electric current supply rod 10. The vertical edges of the titanium sheets 1 are connected by welding by means of members which are also made of expanded titanium sheets.

FIG. 2 shows an elevational view of the lower part of an anode according to the invention having its extended portion which is gripped in the base of the cell, the anode itself being made as described hereinbefore with reference to FIG. 1. The extended portion 11 is a cylindrical jointly drawn member comprising copper and titanium. The copper core of the lower part of the copper-titanium member is exposed at 12 over a height corresponding to the thickness of the base of the cell, the base being preferably made of cast aluminium and indicated by reference 13. A passage 14 in the copper core permits the temperature of the member to be reduced by circulating liquid nitrogen therein, so that assembly and dismantling can be effected by shrink-fitting as described hereinabove, the machining tolerances of the copper core and the bore of the corresponding hole in the base of the cell being gauged in consequence.

Protection from corrosion is effected in the following manner: the base 13 of the cell is covered by a titanium sheet 15 in which are provided circular apertures coaxial with the electrode extended portions. The edge of the apertures is relieved at 16; a washer-shaped member 17 provided with a relieved edge 18 and made from a titanium sheet of the same thickness as the titanium sheet 15 is welded at 19 to the sheath 20 of the member 11, and the edges 16 and 18 are welded at 21. The welding can be ground off before dismantling the anode.

FIG. 3 also shows another mode of gripping an anode extended portion of an anode of the invention in the base of the cell. This Figure again shows the cylindrical copper-titanium member 1 l, the sheath 20 of the member 11, the copper core exposed at 12 at the lower end of the member 11, and the cooling passage 14. In this construction, the base 13 of the cell is covered with a titanium sheet 22 provided with circular apertures through which the extended portions pass. Welded to the sheath 20 is a titanium washer 23 for sealing to the base by means of a toric seal 24 which is crushed or flattened during assembly.

FIG. 4 shows an elevational view of the lower part of an anode extended portion, and the means for electrical connection between the core of the extended portion and the metal base of the cell. This Figure shows the copper-titanium jointly drawn member 25 covered with a sheath 26, a washer 27 welded to the sheath 26, and a toric seal 28. The lower bared end 29 of the member 25 is here provided with an electrolyte leakage purge hole 30, and terminated by a screw-thread. The copper base 31 of the cell has apertures through which pass the exposed ends of the jointly-drawn members, and is protected by a titanium sheet 32 having apertures with turned-down edges, corresponding to the apertures in the base 31. The diameter of the apertures in the base is such that an annular space is provided, for positioning rings with multiple resilient contact means 33 for making an electrical connection between the extended portions and the base of the cell which serves in this construction as a general current input. The electrode extended portion is secured by clamping by means of a nut 34 which is screwed on to the screwthreaded end of the core.

In the foregoing embodiments, it is to be understood that where a titanium component is referred to, it may be substituted with a corresponding component fashioned of another film-forming metal or alloy thereof.

The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed.

What is claimed is:

l. A method of providing a replaceable anode assembly in an electrolytic diaphragm cell, said cell comprising a plurality of vertical substantially flat and hollow anodes formed, as regards at least one of their two substantially parallel faces, by a sheet of a film-forming metal, said anodes being secured to the base of the cell by means of extended portions which pass through the base, said extended portions comprising a core made of a metal which is a good electrical conductor, which core is covered by a sheath made of a film-forming metal, a good electrical contact being ensured between the sheath and the core, said base of the cell being of an electroconductive metal, which base is protected by a sheet of film-forming metal, said core of said extended portions is exposed where it passes through the base of said cell, characterized in that sealing between said anode and said base is effected by welding cup-shaped washers of film-forming metal affixed to said extended portions of said anodes and having a raised edge, to the film-forming metal sheet which protects the base of the cell, whereby said film-forming metal sheet which has a raised edge corresponding to the raised edge of said cup-shaped washers is welded at the raised edges of said cup-shaped washers to effect a seal.

2. A method in accordance to claim 1, whereby the core of said extended portions of said anode where it passes through the base of said cell is gripped by the metal of said base by shrink-fitting by temperature difference.

Claims (2)

1. A METHOD OF PROVIDING A REPLACEABLE ANODE ASSEMBLY IN AN ELECTROLYTIC DIAPHRAGM CELL, SAID CELL COMPRISING A PLURALITY OF VERTICAL SUBSTANTIALLY FLAT AND HOLLOW ANODES FORMED, AS REGARDS AT LEAST ONE OF THEIR TWO SUBSTANTIALLY PARALLEL FACES, BY A SHEET OF A FILM-FORMING NETAL, SAID ANODES BEING SECURED TO THE BASE OF THE CELL BY MEANS OF EXTENDED PORTIONS WHICH PASS THROUGH THE BASE, SAID EXTENDED PORTIONS COMPRISING A CORE MADE OF A METAL WHICH IS A GOOD ELECTRICAL CONDUCTOR, WHICH CORE IS COVERED BY A SHEATH MADE OF A FILM-FORMING METAL, A GOOD ELECTRICAL CONTACT BEING ENSURED BETWEEN THE SHEATH AND THE CORE, SAID BASE OF THE CELL BEING OF AN ELECTROCONDUCTIVE METAL, WHICH BASE IS PROTECTED BY A SHEET OF FILM-FORMING METAL, SAID CORE OF SAID EXTENDED PORTIONS IS EXPOSED WHERE IT PASSES THROUGH THE BASE OF SAID CELL, CHARACTERIZED IN THAT SEALING BETWEEN SAID ANODE AND SAID BASE IS EFFECTED BY WELD-

2. A method in accordance to claim 1, whereby the core of said extended portions of said anode where it passes through the base of said cell is gripped by the metal of said base by shrink-fitting by temperature difference.

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