US1368227A - Osmotic diaphragm - Google Patents

Description

E. A. SPERRY.

OSMOTIC DIAPHRAGM.

APPLICATION FILED DEc.26, 1918.

Patented Feb. 8, v19.21.

- To all fw hom it ymay concern UNITEDSTATES forties.

,nimm A. spenen or 'BnooKLYNi NEW Yoan,"AssieNoRro-ANAGNDA I-.mn- PRODUCTS COMPANY, oF New Yoan, N. Y.,-A conroauroiii or DELAWARE.'

osn'orrc manuellen. 1

Be it known that' I, Emana A, .SPERRY, a citizen of the United States of America, residing at 1505 Alb'ermarle road,` Brooklyn, in the county of Kings and lState of New York, have invented certain new and useful Improvements in Osmotic 41.3iaphragms,' of which the following is a specification. i

This .invention relates to lporous' diaphragms forv use in-biiiuid cells. Morespe-v ciiically it relates, not only, to such diaphragms per se, but to a method of making4 an apparatus forusngthe same,

such diaphragme are capable of vwivde'appli# cation l will, to avoidl surplusage, restrict the present disclosure Vprincipally to the application of the invention to apparatus .des

signed for use in the method of manufacturtrolysis. Such diaphragms. In carrying ontthis'process considerable diiiiculty has been experienced in obtaining diaphrag'rns possessingthe necessary mechanical strength,l durability-v and the proper degree 4or' porosity. Diaphragms consisting of paper, parchmentized or otherwise treated, have been triedas'haye also others consisting of cloth treated '1n Various ways.V Noneoi` these proved successi ful due to the fact thatthey not only lacked;`

' the desired mechanical strengthbut due also to the fact that the necessary osmotic,jper colating, or combined;characteristics Were.-

lacking In fact until the present diaphragm' was invented it was practically im possible to maintain a cell in uninterrupted"- operation for more than a few days. By employing the diaphragm hereinafter disclosed continuous operation .of many' 'weeks` has been attained. Y

One of the primary objects of the present?.

invention is to provide a durable diaphragm preferably osmotic having, the' proper qualities and possessing` greatl mechanical strength. l 1 z methodis vdisclosed in the application for vUnited States Letters Patent by Ralph M. HarringtonHMethodof'producf' ing lead salts, Serialv No. 193,415, filed Se ff tember 27, 1917. This method involves t e employment ofa biiinid electrolytc-cell in: which the ano'lyte and catholyte vare separati ed by a porous diaphragm orjs'eries of-sncli have shown an electrolytic celll comprising a specification@ Leiters ratent. vP5,1;elntm1- 1reb, 8, 1921, .ippiicationgmeginecnibrjzs, 19m/serial zee ,ai'sg lAnother object-is to `provide y a methodof .making 'andiisin'g-suchl diaphragms.- .A-further object-is to provide an electrode which 'supports-the latter -in such a manner fas to prevent riiptiir'e .thereof andshort-cir-- cuiting of the electrodes, and Which supports v .oneliof the electrodes. Further objects and advantages will appear -as 'hereinafter disclosed;

j vReferring .to .thedrawings trate what I now consider a'p'referred phy- 4sical embodiment oi' one-part of -my inven- 'Figurel is' a` somewhat diagrammatic sec-'i y y tional elevation of 'a hi'liiid ejlectrolytif,` cell. ing white lead, or other lead salts, by elec- Fig.- 2 is-anenlarged sectional elevation vof onev ofthe electrode compartments shown line' 4-4 of-.Fig 3.

the invention is V:which illus- 4 v Fig.'5 is a fragmentary sectional-detail of ,l

one'othe 'retaining bars employed.

Referring to Fig. 1, it'y will be seen-that .I

tank or container 1 in .which are mounted' a pliiralityof'spac'ed anodeplates 2 between which Vare located aplnrality of 'cathode compartments 3. Aj preferred form of such compartments vis illustrated lin Figs. '2, 3, and 4 `and may bev constructed.substantially as follows. 1 A plurality of clamping frames, l

vpreferably of woodor other insulating material, are provlded themain' frame 5 being Urslia'pediii i'ormv and provided with guide I grooves V7 fivhicli tliecathode 8 is adapted4 toentei. vTliegdiapliragins), Q are each 'clamped between the main frame and one or the other .ofthe side lframes 4:, 6. Thelattei` are closed frames 'and are ldetachably secu-red to the mainframe 'and toeach `other by means of bolts 10." In order tov prevent :leakage .of liquid, cloth or other stiipsof compressihle'material -11 may `he provided sure, of the catholyte and to prevent contact betweenthe diaphragms, the anode and cathode Which would give rise to a short cirlcuit. These bars may comprise-4 an inner core .of steel coated with a layer of hard rub- 1 ber or other insulating material. A.

The diaphragms preferably consist. of parchmentized cloth or fabric.` One method of makingl one of such diaphragms, especially adapted' for use in an electrolytic cell in the manufacture of white lead, isas follows. A piece of duck canvas of suitable I f size and preferably of comparatively line weave is first freed of grease and other impurities. This ymay be .accomplished by boiling it in a weak solution, say about one per cent. solution of sodium hydrate for about ten minutes. -The fabric may then be washed, boiled inl a weak solutionof hydrochloric or other acid for about ten minutes, t0 neutralize the caustic'solution, and then washed and dried. The fabric is now ready for parchmentizing -which may be accomplished as follows.

The fabric is subjected to a strongsulfuric acid bath, of say 1.750 specific gravity,

for a .lengthV of time depending on .the osmotic and impervious properties desired. The extent of the anastomosingof the `weave `may be variedof course `by changing the length of time of the bath or by otherwise varying the process. 4If it is desired to form It has been found in practice that osmotic diaphragme made in accordance with the method set forth above, swell when moist,

and tend to crack and tear `when allowed to 'become dry, causing tearing'of diaphragm away fromthe frames. It is, therefore, im-

portant that they be kept wet, moist or damp both before and after they are mounted on the frames. This may preferably be accomplished by keeping them in water until ready to be placed into the cells. When the diaphragms are in the cell the problem of preventing tearing and cracking/is more diiiicult. If it were possible to keep the upper edge of the diaphragms submerged or flush with the surface of either or both of the electrolytes, said diaphragms would never become dry. Itis, however, ractically impossible to do this. 4Isolve t e problem by predetermined level.

\ tive and that the invention can allowing theupper end of the diaphragms to project above the surface-of the electrolyte, as shown in Fig. 2 in which the dotted line represents the electrolyte level, and by providing means to prevent the exposed crunimmersed portion from becoming dry. This means may assume various forms, one form being illustrated-in Figs. 2 and 8.

The upper edge of eachdiaphragm is made sufficiently long to lap over the upper edge of the - corresponding side frame 4 or 6. A strip of cloth 14, vpreferably having` capillary or absorbent properties, is placed over each of said upper edges and may, if desirable, Vbe stitched or otherwise secured to the corresponding diaphragm. These strips 14 lshould be of sufiicient area to cover completely the unimmersed portions of the diaphragms. It willfbe obvious that if the vcloth V14 is kept wet or moist, so also will the unimmersed portions of the diaphragme. One

"method of keeping the said cloth 14 moist is by applyingglycerin to it. Another and preferable method is to allow the lower edge,

or edges, of said cloth to project into one or both of the electrolytes and thus convey liquidto the unimmersed portions of the vdiaphragms 9 by capillary attraction. The fabric so used should, of course, be treated to prevent deterioration in the electrolyte used.

Any suitable form of means may be employed to maintain the catholyte, e. the liquid in the cathode compartment, at its For reasons which Will be apparent on inspection of said p'rior application as well as the present application I prefer to employ the system shown somewhat diagrammatically in Fig. 3. The catholyte is continuously introduced into each cathode compartment by means of a long tube 20 which `extends `into and substantially to the bottom of said compartment. The'latter is provided-also with anV overflow pipe 22 which empties into a trough V `23 from which the catholyte is removed at .24.` Obviously the lliquid within thecompartment will never rise aboye the level of the overflow tube 22. i

In accordance with the provisions of the Vpatent statutes, I have herein described. the

principle of operation of my invention, together with the apparatus, which I now consider to are resent the best embodiment thereof, but

desire to have it understood that the apparatus shown is only illustrae carried out by othermeans. Also, while it is designed to luse the various features and elements in the combination and relations described, some of these may be altered and others omitted without interfering with the more `general results outlined, and the invention extends to such use.

Having described my invention, what I claim and desireI to secure by Letters `Patent is:

1. A porous diaphragm for use in a bifluid cell,L-sa1d diaphragm consisting of cloth parchmentized to a predetermined extent.I

A2. An osmotic diaphragm .for'use in an electrolytic cell, said diaphragm consisting of cloth parchmentized to a predetermined extent. y

3. j combination, a parchmentized dlai phragm for a biiiuid cell and means for preventingthe unimmersed portion of said diaphragm from becoming dry. f

4. An electrolytic cell comprising a parchmentizedv fibrous diaphragm and means forI automatically conve ing 'moisture to the unimmersed portion o Said diaphragm to prevent the latter from becoming dry.

5. An electrolytic cell comprising a parchmentized diaphragm and means for automatically conveying electrolyte to the unimmersed portion of said diaphragm to prevent the latter from becoming dry.

6. An electrolytic cell comprising a parchmentized diaphragm and capillary means for automatically conveying electrolyte to Athe unimmersed portion of said diaphragm to'prevent the latter from becoming dry.

7. An electrode compartment comprising a plurality of diaphragm-clamping frames and a plurality of retaining bars secured thereto across the open-space thereof.

8. An electrode compartment comprising a main frame, a plurality of diaphragmclamping frames, one for each side of said main frame and electrode-guide means on said main frame.

9. vAn electrode compartment comprising a main frame and side frames, a plurality of diaphragms eachclamped between said main frame anda corresponding side frame and a luralityof retaining-bars carried by 4each si e frame between the latter and the corresponding diaphragm.

l0. An electrode compartment comprising a main frame and side frames, a plurality of diaphragms each clamped between said main frame and a `corresponding side frame, electrode guide means on said mam frame, and

' a plurality of retaining bars carried by each side frame between the latter and the corresponding diaphragm.

11. An electrode compartment comprising a main frame, a plurality of diaphragm'- clamping frames, one for each side of said main frame, electrode-guide means on said main frame,l and a diaphragm` supporting strip at the top of the frame.

12. An electrode compartmentcomprising a main lframe, a plurality of diaphragmclamping frames, one for each side'of said main frame, electrode-guide means on said main` frame, and a diaphragm supporting v strip at the top of the frame on each side lsaid `diaphragm in stretched position, and

absorbent material covering the upper portion of said diaphragm.

I In testimony whereof I have aiiixed my signature.

vELMER A. sPERRY.

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