US1620052A - Electrolytic apparatus and electrode therefor - Google Patents

Description

March 8,1927.

W. G. ALLAN ELECTROLYTIC APPARATUS AND ELECTRODE THEREFOR Filed se i. 13, 1924 N QN ATTORNEYS.

. eration, stre' Patented Mar. 8, 1927..

UNITED STATES 1,620,052 PATENT OFFICE.

wmmn animals, or 'roaonro, oirr'aaro, cAnanA, ASSIGNOR, BY MESNE Assisi:-

- Mum's, T0 rAnLEY'e. cnaa x.

nnnornonyrrcnrrnna'rns AND ELECTRODE 'rnnnnroa.

Application filed September 13, 1924. Serial No. 737.518.

ments, hydrogen and oxygen in gaseous form, and to electrodes adapted to'be used in the same. F

It has been found that by means of the present invention the efliciency of the deviceis materially and substantially increased when the cell is operated at the same rate of gas production, or gaining a very much increased gas production with an efficiency which is equal to or betterthan that secured with cells, electrodes and diaphragms constructed according to prior apparatus.

The cost of manufacture of the apparatus of the present invention is less than those of thee-known type or, what is conversely true, it'is possible to'obtain a greatly increased output of gas from a cell of a certain size costing a certain amount than is possible with existing devices.

The invention is capable of being adapted to, or embodied in, any type of electrolytic cell, and when so used will increase the elliciency, or the rate of output, or both, according to the conditions under which the cell is operated.

The invention may be applied to a single cell or to a plurality of cells formed in one unitary structure, or otherwise, and is adaptable to either the filter-press, or the pot type of cell, or to a form of cell having the characteristics of either or both of them.

The objects of the invention are To improve, simplify and render more cilicient, electrolytic apparatus in general, and more particularly to improve such devices as used for the electrolytic production of oxygen and hydrogen gases by the decomposition of an aqueous electrolyte containing an acid or an alkali in solution.

A further object is to produce a cell in which the cross sectional area of the current path through the electrolyte is greatly increased without increasing the dimensions of the cell casing, or electrolyte containing vessels, and without sacrificing any of the essential features oi the device, such as purity of the products, efiiciency of opof current, quantity of output, etc;

.l. turtlier GlljfiCi? is to reduce the length of the current path through the electrolyte and diaphragm for a given unit of area of the electrode elements, and at the same time provide greater freedom for the rapid escape of evolved gases out of, and away from, the elctfolyzing zone, thus reducing both ionic and concentration polarizations to a minimum. r

A further object is to maintain, in an apparatus of the character described, the correct balance between the volt-drop across the electrodes; the current density per unit area of the actual electrolyzing surfaces of the electrodes; the current density per unit of ,cross sectional area of the current path through the electrolyte and through the diaphragm, and the temperature attained by the electrolyteat any given current.

A further object is to provide means for the passage through the apparatus of a relatively large current with a low voltage whereby the volume of gas produced will be great compared to the. electrical energy ex pended and with relatively small thermal capacity of the liquid electrolyte and the metallic cell casing.

A further object is to produce a device of the character described, which will be cheap to manufacture, strong and rugged of structure, which will not easily get out of order, which will be easy to repair, which may be assembledin units of'any length, which will have large active electrode surface relatively to the cross sectional area of the cell casing, and which will give a much greater output of gas than other devices of the same size and with the same consumption of electrical energy.

These and further objects will more fully appear in the following specification and ac- 9b companying drawings considered together or separately.

One embodiment of the invention is illus trated in the accompanying drawings, in

which like parts in all of the several figures are designated by similar characters of ref erence, and in whicl1-- Fig. 1 is a horizontal sectional view of a single cell unit comprisin a casing, a pair of unipolar electrodes, and a permeable dia phragm separating the electrodes, and sep arating the cell into an anode chamber and a cathode chamber, the section being talten on the line l-l of Fig.2.

lllli Fig. 2 is.a longitudinal section taken on the line 22 of Fig. 1.

Fig. 3 is a detail view of a form of bot tom or top support for the diaphragm.

Fig. 4 is a side elevation of the same.

Fig. 5 is 'a diagram, on a smaller scale, showing the inside of a cell and looking in the direction of the eurrent path.

Fig. 6 is a horizontal section illustrating a form of bipolar electrode constructedin accordance with the invention, and i Fig. 7 is a section showing a further modification.

For the purposes of this application, the invention is shown as applied to an electrolytic cell of the type shown in my Patent No. 1,464,840 datedAugust 14, 1923, but it is to be understood that this is merely an illustration of the principles of the invention and that the same is not limited to cells of the illustrated type.

In the embodiment of the invention illustrated, 1 and 2 designate a pair of opposed cooperating, annular cell casing members between the outwardly projecting flanges 3,

of which is secured a diaphragm frame member 4 which latter is electrically insulated from the cell casing or frame by gasket elements 5, 5 which may be of any suitable material.

Wall plates 6 and 7 form enclosing end walls and thus produce 'a cell adapted to contain a liquid electrolyte. The wall plates are mechanically connected to, but electrically insulated from, the cell easing members 1 and 2 by means of gaskets similar to 5 5.

' Spacing and thermal insulating members 10 are preferably placed between the flanges 3, 3 and the plates 6, 7. Saidmembers are disposed along the top, bottom and vertical sides of the cell, and the whole is secured together as by means of insulated bolts 11, as shown.

The diaphragm supporting member 4 is in the form of a rectangular frame having a rectangular opening therein, and the opening is coveredor closed by means of a porous diaphragm 12 which divides the cell into an anode chamber 13 and a cathode chamber'ld.

Welded or otherwise suitably secured to the end plate 6 is an electrode ganode) element 15, of a foraminous high y electrical conductive material. The electrode element is folded to plicated or sinuous form and in the drawings is shown as of woven wire cloth. Similarly secured to and carried by the end plate 7 is a more or less duplicate electrode (cathode) element 16. The elements 15 and 16 are so arranged that the plieations extend vertically thereof.

It will be seen that the anode and cathode elements are so disposed with respect to .each other that the plications or sinuosities of the one are staggered relatively to those of the other whereby the sinuosities of one are intruded into those of the other but are spaced apart with approximately the same distance between the opposed faces of all" parts of the elements, except possibly at the point where thecrest of one corrugation is opposite the valley of the other. Those portions of the electrodes which are closest together will define the length of the current path from anode to cathode through the cell.

The diaphragm 14 is disposed between the electrodes as shown whereby the-former is maintained in sinuous form and in proximity to, or, if desired, in close contact with the electrodes except in the valleys in proximity to the plates 6 and 7 where a slight space 17 between the diaphragm and one electrode may be formed.

In the drawings the electrode elements are shown as secured respectivel to the plates 6 and 7 by spot welding and the surplus fused metal at the spots will projectinto the spaces 17. The diaphragm will hug the apices of the plications opposite the spots, and the said spaces will revent the material of the diaphragm damaged by the fused metal, and the spaces will also permit of the escape of gases formed therein.

The side edges of the diaphragm are secured, as by bolting, to the diaphragm frame 4. In addition the top and bottom edges may rest against shelves 18 and be bolted to flanges 19 to maintain those portions of the diaphragm not in the space between the electrodes, in the sinuous position.

Each cell chamber 13 and 14 is provided with means, such for example, as a tube 20, for supplying the chamber with electrolyte, and with a tube or tubes 2O by means of which the gaseous products may be removed therefrom.

The operation of the embodiment of the invention illustrated is obvious.

Figs. 1 and 2 illustrate a single cell having a unipolar anode and a unipolar cathode, but it is to be understood that bi-polar electrodes may be constructed according to the invention by securing a sinuous anode to one side of a supporting plate and a sinuous cathode to the opposite side thereof. Such a construction is illustrated in Fig. 6, in which 21 designates an anode, 22 a cathode and 23 the supporting plate which latter should be of solid. construction and of the same configuration and area as the end plates of the cell structure, and will act as a separating wall between the cells.

A series of such bipolar electrodes together with a unipolar electrodg, as shown in Figs. 1 and 2 at each end 0 the series. and with diaphragms between each pair of electrodes, may be assembled in a unitary structure to form a group of cells yielding rom being teaaoaa above described.

By providing a pair of sinuous or plicated electrode elements, together with a plicated separating diaphragm, the cross sectional areas of the current path between the electrodes and through the diaphragm may be increased to practically any degree desired by increasing the number of the plications and reducing the spaces between them, or by increasing the distance between the apex and base of each plication. or both.

In the embodiment of the invention illustrated, the current carrying area, or cross section of the current path, is about twice that of a cell having plane surfaced elec trodes separated by a plane surfaced diaphra gm. By folding the electrodes and diaphragm closer in order to increase their number within the same superficial area, or by increasing the depth of the plications and that of the cell between the end plates 6 and 7, or both, the crosssecti on of current path between the electrodes may be increased indefinitely.

It will be seen that, in the embodiment of the invention illustrated, each electrode member is composed of a single layer of wire mesh material and that each member may be close to, or even in contact with, the diaphragm. By this means the current path through the saturated, porous diaphragm and between the electrodes will be the shortest distance possible, the diaphragm and electrodes will ofl'er mutual support, and the evolved gases will have the shortest possible distance to travel to get out of and away from the electrolyzing zone, or the zoneof greatest electrical stress. This construction permits of better distribution of the material comprising the electrodes whereby the latter aremore effective and yield ahigher efficiency, or gas output, for a cell of given dimensions and cost. 1

While 'a single layer of wire mesh is, in some situations, desirable as an electrode element, it is to be understood that foraminous sheet metal may beemployed, and that electrode elements composed of laminated fo raminous material, such as that shown in my atent above indentified, may be utilized to orm the plicated electrodes if desired.

Theplications may, if desired or convenient, be of any shape other than that of the zig-zag form illustrated, provided that the distance between the folds will not permit of short-circuiting.

It is to be understood that, while the cell illustrated in the drawings, is of rectangular orm, the invention may be applied to apparatus in which the containing vessel or casing is of any other configuration.

In accordance with the provisions of the patent statutes the principle of the invention has been described, together with the apparatus which is now considered to represent the best embodiment thereot, but it is desired to have it understood that the ap paratus shown is merely illustrative, and that the invention may be carried out in other ways.

The invention having been described, what is claimed as new and desired to be secured by Letters Patent, is as follows:

1. Electrolytic apparatus, comprising an anode and a cathode immersed in an aqueous electrolyte and spaced apart, a diaphragm pervious to the electrolyte and disposed between the electrodes, the saidelectrodes and diaphragm being so constructed and arranged that the area of the current path through the diaphragm will be greater than the greatest projected area of the diaphragm. I

2. An electrolytic cell, comprising an anode member and a cathode member immersed in a liquid electrolyte, a plate-like member at each end of the cell and forming opposite terminals, a portion at least of each terminal being wetted by the electrolyte, the anode and cathode members being so constructed and arranged'that the current path between them is greater in area that the cross section of the electrolyte.

3. An electrolytic cell, comprising an anode member, and a cathode member immersed in a liquid electrolyte and spaced apart, a diaphragm pervious to the electrolyte disposed between the electrodes, a plate-like member at each end of the cell and forming respectively a positive and a negative terminal, a portion at least of each terminal being wetted by the electrolyte, the anode and cathode members being so constructed and arranged that the area of the current ath through the diaphragm is greater than the greatest projected area of either of the electrodes or the diaphragm.

4. An electrolytic cell, comprising a to raminous anode member and a foraminous cathode member immersed in a liquid electrolyte and spaced apart, a diaphragm pervious to the electrolyte disposed between the electrodes and separating the cell into two chambers, a plate-like'member at each end of the cell and forming respectively a positive anda negative terminal, a portion at least of each terminal being wetted by the electrolyte, the anode and cathode members being so constructed and arranged that the cross sectional area of the current path through the electrolyte between the electrodes is greater than the cross section of the electrolyte in the chambers.

5. An electrolytic cell, comprising a Woven llli either the electrode or diaphragm.

6. Electrolytic apparatus, comprising a chamber having a pair of electrode members therein and immersed in an electrolyte, said members being spaced one from the other, a diaphragm pervious to the electrolyte and confined in the space between the members,

the face area of each electrode member. and. of the diaphragm being greater than thecross section of the chamber relatively to the direction of the path of the current from its inlet to its outlet.

7. Electrolytic apparatus, comprising a chamber having a pair of foraminous elec-' trode members therein and immersed in an electrolyte, said member being spaced one from the other, a dia hragm pervious to the electrolyte and con ned in the space between the members, the face area of each electrode member and of the diaphragm being eater than the cross section of the charm er relatively to the direction of the path of the current from its inlet to its outlet. b a

8. Electrolytic apparatus, comprising a chamber having a pair of electrode members therein and immersed in an electrolyte, each of said members being formed of a single sheet of woven wire, said members being spaced one from the other, a diaphragm pervious to the electrolyte and confined in the space between the members, the face area of each electrode member and of the diaphragm being greater than the cross section of the chamber relatively to the direction of the path of the current from its inlet to its outlet.

' 9. Electrolytic apparatus, comprising a cell adapted to contain a liquid electrolyte, a pair of co-operating electrodes immersed in the electrolyte and separated one from the other, the opposed surfaces of the electrodes being in substantially equi-distant relations, each of said opposed electrode surfaces being greater than the greatest projected area of an electrode.

10. Electrolytic apparatus, comprising a chamber having a pair of electrodes therein and immersed in an electrolyte, each electrode having a protruding portion and a re ceding portion, the protruding portion of each electrode being intruded into the receding portion of the other electrode, and a porous diaphragm separating the elec trodes. I

11. Electrolytic apparatus, comprising a chamber having a pair of electrodes therein and immersed in an electrolyte, each elece trode having a protruding portion and a receding portion, the protruding portion of each electrode being intruded into the receding portion of the other electrode.

12. Electrolytic' apparatus, comprising a chamber having a pair of electrodes therein andimmersed in an electrolyte, each electrode having a protruding portion and a receding portion, the protruding portion of each electrode being intruded into the receding portion of the other electrode, and a porous diaphragm in contact with and separating the electrodes.

13. Electrolytic apparatus, comprising a chamber having a pair of electrodes therein and immersed in an electrolyte, each electrode having a protruding portion and a receding portion, the protrudlng portion of each electrode being intruded into the receding portion of the other electrode, and a porous diaphragm separatin the electrodes, said diaphragm following the contour of the electrodes.

14. Electrolytic apparatus, comprising a chamber having a pair of electrodes therein and immersed in an electrolyte, each electrode having 'a protruding portion and a receding portion, the protruding portion ofeach electrode being intruded into the re ceding dportion of the other electrode, a porous iaphragm separating the electrodes, means for mtroducingan-electrolyte into the chamber at each side of the diaphragm, and

means for removing anodic products from the chamber at one side of the diaphragm and for removing cathodic products from the chamber at the opposite side, of the diaphragm.

15. Electrolytic apparatus, comprising a cell consisting of two chambers, said chambers being separated by means of a porous dia hragm, an electrode ineach chamber, said electrodes being of licated form, each electrode being in electrical contact with a wall of the chamber, said walls being in parallel relation to each other, the apices of each electrode being spaced from its wall and in a common plane, the apices of one electrode being intruded into the valleys of the other electrode, there being a sinuous space between the electrodes, said diaphragm lying the current path through the electrolyte to-- ward the cathode wall, said cathode member extending across the cell in the direc tion of the current path through the electrolyte toward the anode wall.

17. A cell containing a liquid electrolyte,

comprising terminal walls in parallel relation to each other, an anode member carried by and in electrical contact with one wall, a cathode member carried by and in electrical contact with the other wall, said members being separated bya diaphragm pervious to the electrolyte and dividing the cell into an anode compartment and a cathode compartment, said anode member extending across the cell in the direction ofthe current path through the electrolyte toward the cathode wall, said diaphragm and electrode members, as a Whole, dividing the chamber in the direction transverse the direction of the current path through the electrolyte.

18. An electrolytic cell comprising a casing adapted to contain an electrolyte, parallelly arranged electrodes of'opposed polarity supported within the casing and spaced apart so as to define a sinuous path, and a pervious diaphragm separating the electrodes and lying within said path.

19. An electrolytic cell comprising a pair of opposed electrode supports, arallel electrodes carried thereby having e ective WOl'l ing surfaces greater than their projected area, and a diaphragm located'parallel to and between the electrode faces and dividing the cell into anode and cathode compartments. I

20. lln an electrolytic cell, the combination with a casing comprising electrode supports, of similar anode and cathode structures carried by said supports, the efiective working surfaces of sald structures being greater than the projected area thereof and being opposed, and a diaphragm separating said opposed surfaces.

21. An electrolytic cell comprising cell frames forming an enclosure for an electro-- lyte, porous electrodes of opposite polarities carriedparallel to each other on the frames, the active surfaces of said electrodes being opposed and spaced apart defining thereby of the other, and a diaphragm separating said electrodes.

.23. In combination in an electrolytic cell, a cell casing having parallel walls, a pair of electrodes of plicated form spaced apart within the casing and in contact with separate walls of the latter, the plications of one electrode coinciding with those of the other, and a diaphragm separating the electrodes and dividing the cell into two chambers.

24. A cooperating pair of electrodes adapted to be used in separate cell chambers, each electrode intruding into the space occupied by the cooperating electrode.

25. A cooperating pair of electrodes adapted to be used in separate cell chambers, each electrode intruding into the space occupied by the cooperating electrode, the means for separating the chambers being disposed between the electrodes and followin the contour of the electrodes.

lhis specification signed this tenth day of September, 1924:.

u i 1 LI f G. l 1 AN.

Images