US652611A - Combined diaphragm and electrode. - Google Patents

Description

No. 652,6". Patented June 26, |900'.4

' J. HARGREAVES. y

CDHIBINED DIAPHRAGM AND ELECTRODE.

(Application med Feb, 12, 189s.) (No Model.) 2 Sheath-Sheet 2.

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we mams persas co., Morell-mn, wAsHmumu, n. c.

UNITED STATES.

JAMES HARGREAVES, OF FARNVVORTI-I-IN-WIDNES, ENGLAND, ASSIGNOR THE GENERAL ELECTROLYTIC PARENT COMPANY, LIMITED, OF SAME PLACE.

COMBINED DIAPHRAGIVI AND ELECTRODE.

SPECIFICATION forming part of Letters Patent No. 652,61 1, dated June 26, 1900.

Application filed February 12, 1898. Serial No. 670,101. (No model.)

of salts by electrolyticlmeans, and particu-p larly to Van improved construction of and method of preparing a combined diaphragm and electrode for use in electrolytic cells.

In the accompanying drawings, Figure lis a section of a combined diaphragm andvelec! trode constructed according to my invention.

Fig. 2 is a part elevation and longitudinal section of a cell of the horizontal type embodying my improvements, Figj?) being a corresponding transverse section. Figs. 3 and 3b are respectively a vertical and a horizontal section, drawn to a larger scale, of the castmetal cap for the electrodes illustrated in Figs. 2 and 3. Fig. Lis an end elevation, and Fig. 5 a vertical section, respectively, of a vertical type of cell constructed according to my improved method... Figs. 4a andy ab are respectively a vertical and a horizontal section, drawn to larger scale, of the cast-metal cap for the electrodes illustrated in Figs.4 a and 5.

According to one part of my invention one side of the diaphragm is composed of a comparatively hard or dense material, the other side being formed of an' open, porous,` or spongy material. As the hard orV dense material offers high resistance to the current, iti4 is preferable to make it as thin as practicable.

With this object the said hard or dense ma-V terial may be attached. to the cathode, the said cathode being formed of wire-cloth.

' In constructing the' diaphragm-electrode the Wire-cloth a is tightly stretched upon a suitable frame and covered with a pasty, porous, or spongy substance b, such as clay or paper, adapted for temporarily performing a retentive function The hard or dense material c is then applied to the upper sur! `of soda to give good results. diaphragms are to be used in a horizontal poface of the porous or spongy substance or to the other side of the cloth, the clay or paper serving to allow the said hard or dense material to iill the meshes or openings in the cloth and to adhere firmly to the latter, but to preserve the side of the cathode which in Working is placed farthest from the anode from being coated with such material. If desired, perforated metal may be used for the cathode.

In preparing a combined electrode and `stratified diaphragm according to my improved method I do not confine myself to the use of any special materials for forming the hard or dense portion of the diaphragm; but Portland cement ywill in manyinstances be found well adapted tothe purpose. The cement is preferably made of such consistency that it may be applied in the form of a thin, but complete, coating with the aid of a brush or trowel; but it may be spread evenly in a powdered condition upon the porous or spongy substance or upon the cathode and fixed by passing a wet brush over it. After applying the said coating. of hard or dense material c a covering d of some material of a soft or porous nature-such as asbestos cloth,

the coating. In practice Ihave found a makterial composed of asbestos with lime indurated by saturation with a solution of silicate When the said sition, the covering of soft or porous material may be composed of loose asbestos pulp or some light amorphous precipitate, such as `silicate of magnesia.

In same cases I use the slag Wool, or the likeis caused to adhere to I aforesaid soft or porous materials, or any of v them, insuch quantity as to iill the space be- `tweenthediaphragm and the anode or anodes.

` In order to provide for the free escape of the' products of electrolysis from the surface of the cathode, I allow a deposit of 4metallic oXid to form upon the said cathode before using it, or I may deposit upon the surface of the said cathode a thin layer of somo soluble substance, which upon being dissolved or removed. will leave a narrow space between the material of the diaphragm and the wire- 'cloth 'forming the cathode. VrIhe deposited metallic oxid is reduced to metal by the current and produces a rough or spongy coating on the cathode, same rendering the action of the cathode more prompt and effective, the escape of hydrogen being facilitated, polarization reduced, anda larger area of the cath- 0de exposed for contact with the liquid.

The anodes e e may be placed in such al the charging-aperture g and is dissolved, as n required, by theelectrolyte h, the latter beingl allowed to rise slightly above the level of the anodes e c. In chargihg the cell with salt care must be taken not to disturb the electrolyte and to prevent the ingress of salt between the anodes and the diaphragm. Steam is injected into the cathode-compartment of the cell by way of the pipe 'L' for the purpose of heating the cell, the steam tending to assist in dissolving the salt. With` a View to avoiding leakage through the sidesl of the anode-compartment A at the places where .the anodes e e pass through them plates of suitable metal, such as type-metal, may be cast around the ends ofthe anodes,

the insides of the said plates being coated i with athick serving of pitch or similar matel'ltl'. l

In constructing a cell of the horizontal type the mode of procedure is as follows: A lead plate 7c, perforated for the reception of the ends of the anodes e e', is served with a coating ofl pitch, the side walls Z Z of the cell being formed against the coated side of the lead plate. The several anodes are placed in position, as shown in Figs. 2 and 3, with their ends protruding through the unpitched side of the lead plate, and a forming-board o r sand is so disposed between the plates as. to leave a space of the required dimensions between the pitched side of the lead plate and the board or sand. Into this space is run the cement which is to constitute the wallsof the cell', the sides and the ends being formed simultaneously. Havingthus constructed the upper or anode compartment A of the cell, the lower or cathode compartment B is formed by applying a tray m, which may be of cast metal, the diaphragm-electrode being inserted between the two compartments, which are then secured together by means of bolts n n. In the vertical type of cell, Figs. 4f and 5, the walls of the central or anode compartment may be formed in a similar manner. In this construction there are two cathode compartments B B,Y the anodes e e in the com-y partment A being disposed in the form of a gridLagainst which the salt rests. In arranging these anodes theslabs of carbon are each placed at an angle to the vertical, so that each slab overlaps the next adjacent slab, ingress'l of salt to the space between the anode and the diaphragm being thereby prevented. The extremities of the anodes e e are inclosed in caps 0 o. These caps are formed of lead or type-metal cast around such extremities, the

`=Inetal occupying a hole or holes previously drilled through the anodes and also covering their ends. By these means the metal which enters the holes forms rivets o2 owherelby the cap is held firmly in position. In cooling the metal has a tendency to shrink upon the carbon, and thereby becomes firmly attached thereto, at the same time forming a .good electrical connection between the car- 'bon and the cap.

The anodes e e in the horizontal. cell are connected up in seriesby means of the con- ;necting-barq, while the anodes e e are simiilarly connectedby the bar q,the positive wire lfrom` the source ofv electric energy being atitached to the terminals 1 The anodes,@ e l on each side of the vertical cell are connected jin series by bars q q, these barsbeing coupled gby means of the cross-bar s.

lof this cell are.. connected by bars q q andv .coupled by the cross-bar s. The bars s and fs are furnished with terminals, to which the positive wire is secured. In either construcgtion of cell the negative wire may be 'conlnected directly with the tray-m.

In operating with the aid` ofthe improved cell water is supplied to the anode-,compartment A, the salt, which may be in theform of Qcrystals, being then inserted through the feeding-omheen. This orificeis closed bya jcover f, furnished with an annular projec- 'tion f2, which dips into a water seal,- whereby the escape of chlorin isn prevented,A or lleakage of chlorin through defects in the joints 0f the compartment A may he` Obviated by producing a slight vacuum in such .the chlorin-outlet. During the progress of the Operation Steam is ejected by'way 0f the pipe 't' into the cathodefcompartment, the resulting product issuing by way of the pipej.

When treating salt solutions'` in a eell,vsu,ch as shown in Figs. 2 and 3, the strong brine. enters the anode-compartment by way of the pipe p', while the weakened brineand chloiin not required when treating. pure salt, the pipe p2 being, however, retained for permitting the escape of chlorin. When treating salt solutions in a cell of the vertical type, Figs, 4 and 5,` the inlet 'p' for strong brine is preferably at the Lower part of the vessel- The weakened or exhausted brine, together with the chlorin,` may be conveyed by way of the ,ing conducted thence to a suitable receiver or utilized directly from said vessel. It the salt liquor contains insoluble` matter in any .important quantity, the liquid is conducted itc a suitable saturating vessel for ehecting e The interme-V diate or alternating anodes e e on each sidev compartment by means of a., fan4 applied to.

areled away by the pipe p2.` The pipepv is pipe p2 to a separating vessel, the chlorin be-V IOO IIO

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the settlement of the insoluble impurities, and thereby intereepting their passage into the electrolytic cell.

The pipes employed for connecting the cells or vessels may be constructed of vulcanite or other suitable non-conducting material.

"What I claim as my invention, and desire lto secure by Letters Patent, is-

1. The herein-described method of preparing a combined diaphragm and electrode for use in electrolytic cells consisting in covering Wire-cloth or perforated plate With a thin layer of clay or equivalent material adapted temporarily to perform a retentive function and ultimately to be dissolved or washed aWay,t-hen applying a coating of Portland cement or equivalent hard or dense material JAMES HARGREAVES,

Witnesses:

JOHN M. I-IEANEY, WILLIAM TOULOUSEn

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