US1376495A - Electrolytic cell - Google Patents

Description

J. M. WILLIAMS.

ELECTROLYTIC CELL.

APPLICATION men SEPT-5, 1916. RENEWED JULY 22, 1920.

Patented May 3, 1921.

[A/V/VTO/fi John M. U117 hams.

WITNESSES:

A TORNEY.

UNITED STATES PATNT OFFICE.

ELECTROLYTIC CELL.

Specification of Letters Patent.

Patented May 3, 1921.

Application filed September 5, 1916, Serial No. 118,323. Renewed July 22, 1920. Serial No. 398,284.

To all whom it may concern:

Be it known that I, JOHN M. WILLIAMS, a citizen of the United States, residing at Guthrie, county of Logan, State of Oklahoma,have invented a certain new and useful Electrolytic Cell, of which the following is a specification.

This invention is an electrolytic cell, and the object of the invention is to construct a cell in a simple and economical manner, and yet one which will operate with exceptional efficiency.

The electrolytic cell of the present invention is particularly adapted for electrolyzing common salt, for the production of chlorin and caustic soda, but its field of utility is not restricted thereto.

Among the features of the invention, though not exclusive, are the following: an improved electrolytic cell wherein a horizontal barrier or diaphragm is positioned intermediate the anode and the cathode, and above the latter, whereby the formation of the cathion or catholyte is facilitated and its removal from the cell simplified and expedited; an electrolytic cellwherein the diaphragm or barrier, preferably composed of asbestos, is supported from below, the support consisting, preferably, of wire gauze, or a perforated metal cathode, or the combiuation of both, thereby permitting of the employment of a relatively thin and light diaphragm, whereby the catholyte readily percolates therethrough as well as reduclng the cost of the construction; an improved electrolytic cell embodying a horizontal diaphragm, preferably composed of sheet as best'os, and which is covered by a layer of finely divided material, such as sand or ground glass, whereby the diaphragm is protected-from undue attack by the anolyte, thereby greatly enhancing the durabihty of the diaphragm; an improved electrolytlc cell wherein the cathode forms the bottom of such cell, in combination with a diaphragm superlmposed thereon, which (haphragm, in addition to lts normal function as a cell element, serves as a gasket to produce a liquid-tight joint between the bottom and sides of the cell; an improved electrolytic cell wherein the electrolyte exerts a uniform pressure upon the entire surface of the diaphragm, whereby the percolation of the catholyte therethrough is uniform throughout the whole area of the diaphragm, thus dispensing with the commonly employed agents for producing a balancing, or partially balancing, effect; and a cell wherein the cathode is preferably not immersed in the catholyte, the catholyte solutlon produced passing through a diaphragm, and away from the active zone of" formation, immediately after its formaion.

Features of the invention, other than those described, as well as the advantages thereof, will be apparent from the following description, read in conjunction with the accompanying drawing. In the accompanying drawing, I have illustrated one practical embodiment of the present invention, but the construction shown therein is to be understood as illustrative, only, and not as defining the limits of the invention.

Figure l is a central section through a cell embodying the present invention and Fig. 2 is a transverse section taken on the line 12 of Fig. 1.

Referring to said drawings, A, designates the walls of the cell, which are preferably formed of cement, although they might be made from any other suitable material which would not be readily affected by chemical action within the cell. The cell is preferably rectangular in shape and around the exterior thereof is a binding member B,

preferably in the form of an angle-iron, one flange of which is embedded in the walls A, and the other of which projects laterally from the surface of the walls, as shown in Figs. 1 and 2.

The laterally extending flange of the angle-iron B is provided with spaced bolt holes through which bolts C are adapted to be passed for the purpose of clamping a perforated plate D in face-abutting relation with the lower edges of the side walls for the purpose of forming the bottom of the cell.

The plate D is composed of metal, preferably iron, and constitutes the negative elec trode, i. a, the cathode, of the cell. It may be either in the form of a rigid perforated plate, as shown, or in any other suitably perforated form. In the embodiment shown,

the cathode D is in the form of a metal slabs 6, preferably of graphite, which are:

bolted together to form a substantially integral structure by bolts 6. Between each two adjacent slabs e, is a spacing member 6 of the same material, so that the slabs are spaced apart, as'shown in Fig. 2, for the purpose of providing maximum superficial area, for exposure to the electrolyte. Moreover'each of the slabs e is provided with saw-cuts or slots 6 for the purpose of further increasing the exposed surface of the slabs. I

The anode E is supported within the cell by off-sets 6?, formed at the opposite ends of each slab and near the upper edge thereof. When the slabs are secured together by the bolts e, the off-sets form continuous surfaces which cooperate-with ledges a, formed on the inner surfaces of the said walls A, as shown in. Fig. 1, and the anode is thus suspended within the cell, above the cathode and free from contact with the latter. Current is supplied to the anode in any suitable manner, such for example, by the metal plate E, which is secured to the anode by one of the bolts 6 and extends above the top of the cell to form the anode terminal.

' Between the anode E and the cathode D, is interposed a horizontal barrier or diaphragm F, preferably of asbestos. In the preferred embodiment of the invention, the asbestos is in the form of a relatively thin sheet, which is superimposed upon the cathode, and is of such size as to overlap the lower edges of the side walls. Being more or less yielding in its nature, it thus serves, when clamped between the cathode and loweredges of said side walls, as agasket. Such construction maintains the diaphragm in a flattened condition, and also makes the cell economical to manufacture in this particular, as no additional packing is required. When the cell is utilized in the oroduction of chlorin, sufficient electrolyte i is introduced within the cell to submerge the greater portion of the anode, and the electrolyte is, when the cell is used for the production of chlorin, a solution of common salt. This solution may be fed into the cell through an inlet pipe 9 in initially charging the cell or, in subsequently recharging the same.

The electric current is fed to the positive terminal plate E and is led from the negative terminal a. When the electrolyte is decomposed, the chlorin constitutes the anolyte or anion and accumulates at the anode,

the diaphragm and comes into contact with the cathode, it immediately flows through the perforations therein and drops free from the cathode. The caustic soda, thus freed from the cell, may be disposed of in any suitable manner; for example, it may fall into a catch basin I positioned beneath the cell and provided with a valved draw-oil i.

It will be manifest that the descent of the catholyte is accelerated by the impelling electrical force of the cathode, by the force of gravity, and, in addition to these forces, by the hydrostatic pressure of the electrolyte G. Moreover, the liquids are prevented from mixing by their difference in specific gravity; the electrolyte being about 1.18 spe cific gravity, and the catholyte, caustic soda solution, about 1.27. As the diaphragm F is preferably made relatively thin, the re moval of the catholyte is astonishingly 1 rapid.

Stratification is thus not necessarily essential in the present cell, as it is in the prior art cells, and, moreover, the hydrostatic pressure of the electrolyte is uniform throughout the entire area of the diaphragm. Hence the percolation or passage of the catholyte through all portions of the diaphragm is equal and uniform. This dispenses with the employment of any element or agent to produce a balancing or partially balancing effect, as has commonly been necessary, particularly in vertical cells, or those wherein the diaphragm was placed vertically instead of horizontally as in the present cell.

A pipe 7 is shown as leading into the interior of the cell, and through this pipe a gaseous pressure, such as air, may be introduced into the cell for the purpose of expediting the removal of the products thereof; that is to say, for forcing the chlorin, accompanied by any other gas or gases of decomposition, out through the pipe 71 and, also, the catholyte through the cathode I) into catch basin I.

In the preferred embodiment of this invention, as described, the cell is extremely rapid in its operations. Moreover, because of the close proximity of the anode to the cathode, the cell is of exceptionally low resistance, thereby permitting the employment of a current of minimum voltage or electromotive force, with attendant economy of operation. The supporting of the asbestos diaphragm F from beneath, by the cathode D, makes it possible to employ a diaphragm of minimum thickness, thereby increasing the rapidity of operation of the cell, and the fact that the catholyte is freed from the cathode, almost immediately after its formation, minimizes chemical action of the catholyte upon the cathode, there being no catholyte liquid body constantly in contact with the cathode, as in most prior art cells, and particularly in those wherein the cathode i arranged vertically instead of horizontally.

It will be manifest from the foregoing description that the invention is not restricted to all of the details of construction enumerated, as various slight changes might be made from time to time in adapting the invention to its various environments, and to the decomposition of various electrolytes;

for example, the sand or protective layer J,

while distinctly advantageous, is not always essential; the catholyte need not fall through the atmosphere into the catch basin I as shown, but might fall into a closed chamber, with which a suction device is connected for the purpose of expediting the flow of the catholyte. Furthermore, the diaphragm F need not necessarily be superimposed in face-abutting relation with cathode D, as it might be supported in any other suitable manner. In some cases, the catholyte may be allowed to flow into an inert atmosphere, such as hydrogen, whereby chemical action of the air on the catholyte is precluded.

The operations hereinbefore described constitute a novel method, and I reserve the ri ht to file a divisional application therefor.

aving thus fully described the invention, what I claim as new, and desire to secure by Letters Patent, is:

1. .An electrolytic cell embodying a substantially horizontal perforate bottom forming the cathode of the cell and side walls provided with supporting shoulders on the interior thereof, an anode positioned within the cell and embodying a plurality of slabs positioned entirely within the cell and individually supported on the shoulders of the side walls, whereby the slabs are supported to the exclusion of apertures in the side walls of the cell, in combination with an asbestos diaphragm superimposed on the cathode and intermediate said cathode and anode so that, when an electric current is passed through the cell, the catholyte is caused to pass through the asbestos diaphragm.

2. An electrolytic cell embodying side walls provided with supporting shoulders and a substantially horizontal perforate bot tom, said bottom forming the cathode of the cell, an anode supported interiorly of the cell and by the said shoulders of the walls there of, an asbestos diaphragm superimposed upon the cathode and intermediate said cathode and the anode, attaching members partly embedded in the exterior surfaces of the side walls of the cell, and means cooperating with said attaching members and the cathode of the cell for holding the latter securely in position.

3. An electrolytic cell embodying side walls composed of cement and a perforate metallic member forming the bottom of the cell and constituting the cathode thereof, an anode positioned interiorly of the cell and composed of a plurality of comb-like members secured together, and a substantially horizontally disposed diaphragm positioned intermediate the anode and cathode whereby, when an electric current is passed through the cell, the catholyte passes through said diaphragm.

4. An electrolytic cell having a bottom in the form of a perforate metallic cathode and having side walls provided with interior shoulders, an anode positioned interiorly of the cell and embodying a plurality of parallel spaced graphite slabs provided at their tops with off-sets, whereby they are individually supported on the shoulders of the side walls to the exclusion of apertures in the side walls of the cell, and an asbestos diaphragm positionedintermediate the cathode and the anode.

5. An electrolytic cell embodying an anode, a cathode, a diaphragm, formed from material pervious to the catholyte, positioned horizontally between the anode and the cathode, whereby, when an electric current is passed through the cell, the passage of the catholyte through the diaphragm is facilitated by the force of gravity and the hydrostatic pressure of the electrolyte, and means for introducing a gaseous material under pressure into the cell, whereby the gaseous products resulting from the electrolysis may be forced out of the cell.

6. An electrolytic cell embodying side walls provided with supporting shoulders adjacent the upper edges thereof, a substantially horizontal perforate bottom forming the cathode of the cell, and an asbestos diaphragm superimposed on said cathode, in combination with an anode positioned within the cell and provided with shoulders cooperating with the shoulders of the side walls for freely suspending the anode within the cell, and above the asbestos diaphragm, and a cover resting upon the top of the anode for the purpose of holding the same tightly to its seat on the shoulders of the walls and simultaneously closing the top of the cell, whereby, when the cover is removed, the anode is free to be lifted unobstructedly from the cell.

In testimony whereof I have signed my name to this specification.

JOHN M. WILLIAMS

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