Патент USA US2116509код для вставки
May 10, 1938. 2,1 16,509 F. G. coTTRELL ELECTRIC FILTRATION SYSTEM Filed oct. 2. 195s 2 Sheets-Smet 1 f/v ds/v Toe. Feeose/ag Gmane@ Carreaux YWfl 14 frog/v5.1 May 10, 1938. F. G. coTTRELL 2,1 16,509 ELECTRIC FILTRATION SYSTEM Filed Oct.' 2, 1953 2 Sheets-Sheet 2 2,116,509 Patented May> 10, ‘i938 i UNITED STATE S»VY PATENT ‘OFFICE - 2,116,509 ELECTRIC FILTRATION SYSTEM , Frederick Gardner Cottrell, washington, D. c., asdgnor to Petroleum Rectifying Company of California, Los Angeles, Calif., a corporation of California 'Application october 2, 193s, serial No. 691,806 ` 22 Claims. (c1. 2114-24) This invention relates to Aa method and appa ratus for removing foreign material from a liquid by the use of an electric field which is preferably of a unidirectional character. More particular 5 ly, the invention 'comprehends the application of cataphoretic principles in a novel manner. .'I'he~ problem of separating foreign material from a liquid phase has been long recognized. Attempts have been made to move such foreign material from the liquid by applicationl of a uni directional elect'ric field so that the foreign parti cles migrate toward one or the other of the elec trodes where they are deposited. However, it is seldom possible to remove al1 traces of this foreign material. For this'reason l’. have found it desir able to utilize aiilter material in conjunction with an electric field, and such a system is included among the objects of the present invention. Another feature of the invention is to maintain ' an electric field adjacent a filter surface so that comes desirable to remove this concentrated ma terial therefrom. \ - - By proper design of the system it becomes pos sible to maintain in the electric field foreign par ticles which are both positively and negatively ta charged, as will be hereinafter set forth, and one of the features of the present invention is to sub ject the incoming mixture to such a field whereby the oppositely charged particles not only tend to themselves neutralize and thus form` .larger 10 masses, but-also tend to contact the dispersed particles of the incoming mixture to unlte'there with in forming masses of larger size. One process with which the present invention finds particular utility is the electrical dehydra tion of petroleum emulsions. Such a conven tional dehydrating process includes the building up » of an velect-ric field, usually of alternating character and of hi-gh intensity, so as to coalesce dispersed water droplets of the petroleum emul 20 sion- into masses of sufficient size to gravitate 2o at least a portion of the foreign material is moved from the oil. The meeting of present commer away from this surface through cataphoretic Vac cial standards requires that such a dehydration tion, thus preventing accumulation' of a large system_ reduce the water content of the oil to at quantity of the foreign material on `the filter least 3%. In many instances, however, it is de itself. In this way it is possible to' eliminate 25 much of the frequent cleaning of a filter surface sirable to remove even a. greater proportion of the water, and it is in this capacity that the pres such as is necessary in existing processes where . ent invention can be utilized, the emulsion being in filtration alone is utilized for separating the first subjected to an alternating current field foreign material. ' and later subjected to a unidirectional field after Another feature of the present invention is to a certain amount of settling has taken place. move the mixture through a distributing mem The above and still `further features and ob ber, and to set up an electric field into .which the jects of the invention will be evident to those mixture moves, this field acting to stop or com skilled in the art from the following description. ` `pletely reverse the direction of movement of the Referring to the drawings: The field can l foreign material in the mixture. Fig. ll diagrammatically illustrates the simple be so designed as to return this foreign material form of treater capable of carrying out the proc to the distributing member from which it came. Another feature of the present invention re Fig. 2 illustrates the treating system in con-sides in the use of a movable member on which 40 junction with an electric dehydrator. 40 the a foreign material ' is deposited so that this Fig. 3 is an alternative form of combined treater member can be removed from the fluid either and dehydrator. ' continuously or intermittently so that a cleaning Figs. 4 and 5 are alternative forms of the treater thereof can be effected and so as to present new shownin Fig. l. Referring particularly to Fig. 1, I have ‘dia 45 surfaces to the fluid. 4 il It should not be understood, however, that it grammatically shown a tank I0 across which al is in all instances necessary to utilize an electric porous member Il extends to define-an intake chamber I2 to which the incoming mixture is field of sufficient intensity to cause foreign ma supplied through a pipe i3. This porous member terial to deposit on one or the other of the elec is preferably one having relatively good electrical 50 trodes. The invention also comprehends a proc 50 insulating properties `and is relatively coarse ess wherein the electric field maintains thefor eign material suspended therein while the liquid grained toprovide interstices which are of great er size than the dispersed particles of the in phase -can now therethrough, this forel-gn ma terial remaining in the field and increasing the . coming mixture. This mixture may thus move 55 through the porous member H and into a treat concentration therein until such time as it be 56 ess. ' , ' > 2 f 2,11e,5o9' _ v .I >ing space I5 without substantial yaccumulation Vstances return the foreign particlestowardA the . of the foreign material on the intake surface of " 'porous member ¿ this porous member. _So also. the'foreignV-ma terial is in _the form of a dispersed liquid, the provision of-intersticesin the porous-member II of larger size than the dispersed droplets -will emerged. y. The iield can be made suiiiciently in ' prevent any further subdivision 0f these drop-. lets as the mixture moves through this member. II from which -they- have tense to actually deposit the foreign material on the porous member II, allowing.v substantially pure liquid to move rlghtward and through the filter plate. 22. Any remaining foreign particles not separated by the electric field will ofcourse ` An electric iield is set up in the treating space ' be deposited on the filter plate 22. 10 I5 by any suitable means. »In the form shown One of the primary advantages accruing from _- the porous member-` Il supports an"interstitial electrode vI5 which extendsonly partially acrossthis member‘so that theend portions of this such a process is that the foreign- material is deposited‘upon' the porous member II as `dis tinguished from the ñlter plate 22 which would ’ porous member act to insulatethe'electrode from become quickly clogged by such a deposit. The ' It is~ possible to form this elect-rode pores of -the member- II `are relatively large and . by various means. Thus,- the porous surface of _v are not'easìly. Vclosedby a deposit of the foreignv _Y the member IIl can 'be sprayedvor. otherwise material, even if this foreign material is in the coated with a metallic substance to form the . _form of a solid substance. If the foreign mate interstitial electrode'V I6, care being. exercised not rial is- in the form of a liquid, at least a por to deposit suiiicient conducting material to'close tion of this liquid will come into contact with ` - the interstices of this porous'member. In other .the porous member Il or the electrode and may 15 the tank. _instancesit is possible to mount a metallic- screen move downward therealong by gravitational force or perforated plate along this. surface of the. po- __ if the liquid thus accumulated is of greater den rous member II, as diagrammatically shown in sity'than and will- move the continuous upward if of phase -less ofthe density».Y 25 Fig.. 1. In any event_-aconductor I`I supplies a potential to this electrode 'I6 and extends through ‘I‘he electrodes I6 and 25 do not form iields ' _a suitable» bushing I B and to one ‘terminal of a of uniform gradient thereadjaoent. Instead, the lgenerator I9 >»preferably _off the direct-current field is concentrated at sections along the me tallic members of the screen,-or adjacent the .30. »A iilter plate 22 extends- across the tank- VII! crests or minute edges of the electrodes. Thus. .and separates the treating space_I5-from a dis while some of the foreign material will' be de charge _chamber '2_3 communicating with a pipe posited on the porous member _II or the elec 24.» This ñlter plate is'pre'ferably formed of a trode I6, 'other of the- foreign particles will be i "filter material'having only very minute pores. 35_ -Usually it is desirable'to utilize a filter plate ‘ -which would in itself _ iiiter from the mixture subjected to a somewhat different action as they move >leftward against the rlghtward flowing. 35 stream of liquid.- When these particles come into some or all of the _foreign material of the mix thevicinity of one of the high field-intensity ture. The -material Aforming this iilter plate may portions of the iield adjacent the electrode I5, ^ , . vbe one having Agood electrical insulating proper- -` they appear> to come into electrical contact there 40 ties so as to' itself act as an insulated support with, thereby' receiving the charge of -the elec for an interstitial`- electrode 25 extending there- ' trode, -and are then repelled from the electrode along but spaced from th'e- tank III.> This inter -in the-direction of ilow of the mixture through stitial electrode may be formed in a manner sim-î the treating space I5.- Apparently, the ileld con ilar to the -electrode liso -` that the liquid of the ditions adjacent the electrode I5 control thisV ac 45 Amixture -can readily pass therethrough. A oo_n ductor 21 energizœ this electrode; and extends vthrough a bushing 28 andis also connected to ' the generator I9. "I'his generatorv may be of the. variable-voltage type whereby the potential be 40 tion. Thus the system may be» so designed and operated that" -some ofA the foreign particles reaching the most intense portions of the ileld are subsequently discharged from the vicinity of the electrode I6 rather than clinging thereto, tween the electrodes I 6 and 25 may be varied. these particles thus discharged of course moving If- desired, a variable. resistance.”l may be yin- f toward the electrode 25 which is ‘of opposite sign. serted in series with this generator to4 control this In fact, they move through _the treating space j potential. ‘ I5 at a velocity controlled both >by the electric In the' operatic-rn- of this form voi' vthe invention iield and the stream .of mixture, these particles v55 ~the mixture to be treated enters the intake cham thushaving a net velocity which is higher than ber I2 through the pipe I3, and the porous mexn-v ‘ the mixture. Some of these particles may come into contact with the electrode 25 and be there _ ber I I acts as a distributing means for discharg ing this mixture into thetreating space I5. In the .absence of any electric field in thistreating space, thismixture will move rightwardther'e-- on deposited. Other of these particles will be repelled from the electrode _25 after they have come into electrical contact therewith and have 60 across-lat -a uniform velocity and the> foreign thus received a chargewhich is opposite in sign material .will be deposited on the surface _of the _ to the charge which they possess when moving «ñlter plate~22_, the liquid'iiowing therethrough rlghtward. _ The net eil'ect is that the treating ~and being. withdrawn through the pipe 2l. 'If an electric _ileld is impressed between' the elec _ trodes I5 and 25'._"the.action on- the foreign_`par- ticles will depend-upon the inherent charge there space I5 contains particles of foreign material some of which are charged' positively and some of which are charged negatively.. There is a force tending to bring such oppositely charged on. a The neld canv vbe ,built up so as to either particles into contact‘with each other if they -increase ‘or retard the normal movement of these are suñiciently close. 'i‘he result is o_f course foreign particles as they are carried along with that such particles join together and the charges the liquid'. Usually I iind it preferable to utilize thereon are substantially neutralized. 'If the an -electric iield- which acts not only to retard `the forward Amovement of theseioreign'parti-j cles toward the iilter plate 22, but actually to -prevent such forward movement and in most in particles comprise liquid droplets they coalesce and thus tend to ldrop in the treating space Il. being possibly contacted during their downward movement by other charged particles of the 15 arranca foreign material moving between the electrodes. 8o also, the charged particles thus moving in the iield tend to come into contact with the. particles of foreign material newly introduced into the field, thus tending to facilitate separation thereof. 0n the other hand, the field will contain charged particles which move therein without becoming neutralized> and which particles will travel back and forth in the field. This is shown by the fact that the material in the treating ' Y ’ 3 I5 previously described, is shown as being placed immediately inside the porous member Il. A cen tral electrode il of relatively small sine extends therein. Any suitable means may be utilized for setting upa unidirectionalileldinthespacebe tween electrodes l2 and 53. In the form shown I have illustrated a transformer Il as su alternating current to the electrodes 5I andjl. and a vaculnntube or other reciifying device 'Il connected to the incoming line and delivering 10 unidirectional current vto the electrodes 52 and all of the foreign material is vdeposited on the 53. If desired a suitable choke and filter system electrodes. but in other instances a portion of _ may be used in conjunction with the rectifying this foreign material remains suspended in the device 'il so as to eliminate some or all of the treating spaœ so that eventually 'it is desirable ripples which would otherwise appear in the po 15 space Il increases in concentration as treatment . Thus, in some instances substantially to remove the concentrated material therefrom. This may be done intermittently. the material being moved through a pipe 3| communicating -'«\ :witha funnel I2 of the tank Il. In other in stances it is possible to continuously remove a small portion of the liquid in the treating space Il through the pipe ll. ` Referring to Fig. 2 Iv have illustrated a treat - ing apparatus similar to that shown in Fig. 1 as used in conjunction with an electric dehydrator tential delivered to these electrodes. , In this form of the invention the oil,v together with a minute amount of water carried therewith, moves through the porous member and’through the electrode i2 and into the electric ileld. This ßeld is preferably designed to move the dispemed particles of water toward the electrode fl so that ' this water can coalesce around this electrode and drop from the lower end thereof and into a funnel 12 which discharges above a distributor plate 13„ thus preventing direct return of this 3l. This dehydrator may be of conventional con water to the treating space 55 but delivering same struction including a tank 36 in which live and grounded electrodes Il and 3l are respectively to the ileld around the electrode 54. In other instances, however, it is possible to reverse the positioned to define a treating space 39. 'I'he in connections on the electrode so that the water 30 coming emulsion is delivered through a pipe Il - particles will‘be moiled toward the outer elec to a pump Il which forces it into the treating space I! where it is subjected to an electric ?eld trode 52, flowing therealong and into the funnel 12. In any event the dry oil is removed through set up by a `transformer I2 connected to supply a pipe 14 and delivered to a suitable storage. < ‘lines ß as shown. 'I'his ñeld acts to coalesce This form of the invention utilizes a ileld which 35 the ‘dispersed water particles of the incoming more intense adjacent the central electrode Il emulsion, and the coalesced masses settle in the is than adjacent the electrode 62, this ñeld being tank I5 and are withdrawn through a pipe M. thus of non-uniform intensity. Such an elec The 011 rises in the tank 3i and is withdrawn trode structure is often advantageous when cer through a pipe l5. 'I‘his oil is not, however, us tain types of mixtures are being treated, regard 40' ually in a pure state, but carries a small percent less of whether these mixtures comprise water age oi' water therewith. particles or solids suspended in an`oil phase. A treater similar to that shown in Fig. 1 is In Fig. 4 I have illustrated a Systemfwherein illustrated as being connected to the pipe 45 so at least a portion of the, foreign material is de - that this mixture oi' oil and water ilows there through as previously described. The pipe 3| - posited on a moving member and then withdrawn 45 oi' this treater preferably communicates with the from the treating space. A tank Il is illustrated, intake oi' the pump Il and includes a valve 46 one portion of the tank'comprising an intake controlling the flow therethrough. The pump Il chamber 8| bounded by a porous member I2 and a wall 83. The mixture may be delivered to this »0 thin can be used to draw the Awater or other mix intake chamber through al pipel » Il. and» flow ture from the treater and return this to the through the porous member and into a treating electric held of the dehydrator for further treat ment or disposal. The dry oil moves through the space l5. An electrode II similar to that pre pipe 2l of the treater to a suitable storage means. viously described is mounted on the porous mem 82. Similarly, a discharge chamber l1 is In this form of the invention I have illustrated ber formed in. the opposite end of the tank Il being 55 a motor-generator set I1 connected to the sup ply lines I3 and supplying the potential to the bounded by a ñlter plate 8l and a wall Il. This filter plate preferably mounts an electrode Il electrodes Il and 25. > In the form of the invention shown in Fig. 3, , similar to the electrode 25 previously described. v A roller 9| is ’shown as being rotatably' mounted both treaters are enclosed in a single tank 5D. . Here the incoming emulsion moves through a pipe below the filter plate 8l and a corresponding roller Il and through a nozzle'52 surrounding a rod 92 is positioned thereabove and outside -the tank electrode 5I maintained at ground potential. A 80. A movable member, preferably in the form of a continuous belt 53, extends ltherearound. live electrode in the form of a shield 54 is posi One of the rollers is suitably driven so that the tioned therearound, cooperating therewith in de lining a treating space 55 in which coalescence belt 93 moves upward adjacent the electrode Il. This belt means is preferably interstitial in char takes place. 'l‘he heavier constituent ofthe emul lion ß moved from the tank 50 through a pipe acter and may be formed of metallic screen as Il. while the substantially dry oil moves upward shown. In other instances this belt may' be of 0 into a chamber 5I defined between a dome 59 cloth, preferablyA formed of a material which is and a porous member lll. This material then water wettable- It is not, however. necessary 70 mom through the porous member and into a that this belt be formed of conducting material all instances, though if ever it is thus formed heating space Il wherein a unidirectional ileld in it will be clear that the belt can be in actual h prderably established. In this form an inter electrical contact with the electrode il, if de 5 stitial electrode I2. corresponding to the electrode sired. The beit would uien :n itself comprise an rs vil» 2,116,509 electrode. .. In other instances' the belt can .be spaced slightly therefrom as shown. In any event any electricl field is established in the- treatingv space 85 as by a battery or other source 9G. This 5 ñeld is of such a character as to move the foreign material oi the incoming mixture in a direction toward the belt 93 so that it comes into contact therewith and is moved upward as the belt rises. If the foreign-particles ofthe mixture are formed -of a sol-id material, as, for instance, carbon, this material will be> deposited en_the external sur-l face of the belt and can be removed therefrom , y - whereby the concentration of said suspended maf.` terial in said iield increases >as treatment pro-l gresses, the lines of forcein said field being sub- I stantially parallel to the direction of flow; ,and removing lsaid- suspended mattery from 'saldi-field; ' 3; A method. of ltreatingv aëmixturebf aY liquid> and a suspended materialfby the use ofl a'filter . » plate having interstic'es of smaller size than the particles oisaidsusp'ended: matter and by the use of a porous¿member having interstices of 10 larger size than said- particles„`which method in-cludes the steps iik-'continuously moving a stream by suitable means spaced above the tank 80 and , oi said mixture'throug-h said porous member and f ' shown as comprising a scraper 91 dischargingv The liquid phase of the mix-' ture moves through >the filter -plate 88 andv into; the discharge chamber 81 whence it is Withdrawn j through a pipe 99. In the -form of the invention shown in Fig. 4 20 the downward moving portion of the- belt 93 ‘isV shown as moving. through the chamber 81. l'If this is undesirable a form such as `shown in. Fig. 5 -15 into a hopper 98. may be utilized. Here the discharge chamberv is indicated by the numeral' lill and is` formedf by e an open-ended shell |02 closed. by a filter plate |03 similar to that previously described.'_j A` dis _ charge pipe |04 conducts the liquidtherefrom. This shell is positioned directly above the -lower 30 -toward said iiltergplate; establishing an electric field of unidirectional characterfin the-space »be-1' vtween lsaid porous member and lsaid filter'plate and oi'a character> to ca'taphoreti'cally move said ' particles in a direction toward said porous mem ber therebyfpreventing deposit oi said particles I ‘ on. said ñlter plate; .and vmoving said liquid »through said _filter plate fto remove any particles not removed -by `said electric’field. f ‘ fi. A methodk of treating a »mixture of a liquid and a suspended material >by 'the use of a porous ‘ member havingjinterstices of larger size than said suspended material, which method includes the steps of: flowing 'said' mixture continuously through saidporous. member; 'and establishing» , roller 9| and between the upward andjdownward~ an Aelectric field through which said mixture `moving portions of the belt 93. The entire tank movesvafter passing through said porous member, l30 80 may be filled with liquid'to a level indicated said electric >field acting to cataphoretically move> by the numeral Ililì.l Alsoin this form of -the'` the particles of ksaid suspended rmaterial in a invention a scraper |01 may beused for remov» *direction toward' said _porous member andlinto . -1 y ing any Imaterial carried-upward by the belt 93, contact therewith.v v 5. A method as'deiined in claim 4 in which said . this material sliding down a plate |08 and into a VhopperlliS. ' . Y It is sometimes possible to reverse the direc tion of flow through the forms shown in Figs. 4 and 5, discharging the pure liquid through the 40 pipe 8l and, if desired, reversing the position of the porous member and ñlter plate. Usually, VVhowever, this is not preferable in view of the fact ' that the incoming mixture must iiow through the belt means before moving into the central portion of the field. However, with a belt of inter stitial character, this system can often be used Li porous :member forms one electrode for establish ing said electric field thus bounding said i'leld. ' 6. A method of electrically treating a mixture to separate the constituents thereof, which meth od includes the steps of : establishing an alternat ing and a unidirectional electric ñeld; moving said mixture into the alternating-held; partially separating said constituents; moving. one of the constituents thus partially separated into said unidirectional field wherein vtheÍremainlng con 43 stituents are separated; and returning by'gravity' and> the -belt `»can thus act as a porous member ` one of said constituentsthus separz'atedl in said through »which the incoming mixture moves. unidirectional iield .to said alternating ileld. 7. In combination in‘an»electriclseparating de- With such a -ñow it is usually desirable to main 50 tain the unidirectional field ‘of such character as Yto return the foreign material to the belt 93 from which it is removed at a position outside the tank’ßll. In other instances a belt means may be pro vided adjacent the porous _member 82 as Well as ` the' filter plate 88, thus removing from the vicin - ity of the electrode 86 any foreign> matter which mightfotherwise deposit on this electrode' due to » the action of the, electric iield. to I claim as my invention: vice for treating a mixtureoi _’a‘liquid and a sus-~ pended material: , a’ v'illter plate; Y disposed adjacent a iorwarcf‘isurf ter plate; a second electrode-disposed in spaced relationship with `said first electrode and posi tioned on the same side oi' said illterfplate as said _ iirst electrode; means for movingthe `suspended particles in a direction awayirom said 'filter plate and -including' means for ' establishing a' po-,- tential ‘dliferencebetween saidelectrodes with _the potential so »maintained _that the electric‘ileld 60 1. A method'oi' treating a mixture of a liquid thus established betweenïsaid electrodes> acts to and a suspended material, which method includes move theV -suspended'particles to be; separated the steps of : forming a stream of said mixture away from said iilter> plate; means for continu-. ' ously flowing said mixture in said field toward said' moving in a given direction; setting up an elec tric field acting to move said suspended material filter plate; and means for withdrawing said liq in a direction opposite to said given direction and uid after it has passed through said illter plate; 8. In combination in an electric separating deat a velocity greater than the velocity of said vice for treating a mixture of a" liquid and a sus stream oi.' said mixture; and collecting said sus pended material: a filter plate providing an in pended material. . y2. A method of treating a mixture of a liquid terstitial surface of electrical conducting-mate -and a. suspended material, which method includes rial and forming a first electrode; a second elec# the steps of :' forming a. stream ol' said mixture trode disposed in spaced relationship with said iilter plate; means for setting up an electric iield moving in a given direction; setting up an elec tric ñeld acting to move said suspended material between said first and said second electrodes and -in a direction opposite to said given- direction acting to move the suspended particles to be- sep 65 i i 70 'Il 2,116,569 arated away from said filter plate; means for con tinuously flowing-said mixture in said field to ward said ñlter plate; and means for withdrawing said liquid after it has passed through said filter ‘ plate. 9. In combination in an electric separating de vice for treating a mixture of a liquid and a sus pended material: a porous member; a filter plate spaced from said porous member to define a space therebetween; means for flowing said mixture through said porous member and toward said ?ll ter plate: and means for establishing a unidirec tional electric ileld in said space to attract said suspended material and prevent deposition of the whole of said suspended material on said filter plate, said liquid moving through » said filter plate. ' ' 10. In combination in a treater for separating a mixture of a liquid and a suspended material: a 20 tank containing said mixture; a movable inter stltial member of lelectric conducting material and forming a first electrode, the surface of said interstitial member being movable from sub merged position in said mixture to a position 25 above said mixture; means for moving said inter stitial member to move said surface from said submerged position to said position above said mixture; a second electrode in front of said first electrode; means for establishing an electric field 30 between said electrodes tending to move said 'suspended material toward said first electrode of interstitial character; 'a filter means to the rear of said first electrode and receiving the liquid and any unseparated suspended matter passing through said interstitial member; and means for withdrawing said liquid’passing through said fil ter. - , 1_1. In combination in a treater for separating a mixture of a liquid and a suspended material: a tank containing said mixture; a movable in terstitiar member and providing a front portion and another portion spaced therefrom, both por tions being in said tank; a filter means between said portions of said movable interstitial member and receiving any liquid and unseparated sus material moving downward from the interiore! said cylindrical electrode; and means for estab llshing an electric field of alternating character in said emulsion zone and to which field said por tion of said material reaching the interior of said cylindrical electrode is delivered. 14. A method of treating an emulsion by the use of a cylindrical interstitial electrode, which method includes the steps of: setting up an elec tric field adjacent said cylindrical electrode mov ing a treated portion of said emulsion into the interior of said cylindrical electrode through' the interstices thereof ; establishing an electric‘ñeld of alternating character below said interstitial electrode; moving at least part of the treated por tion of said emulsionentering said ‘interstitial electrode downward from the interior thereof and into said field of alternating character; andl introducing additional emulsion to be treated into said ñeld of alternating character. 15. A method of separating the phases of an member, which method `includes the steps of: first passing said emulsion through one portion of said interstitial member whereby some of the tcrstitial member. - ' and removed from the emulsion; then moving the remaining emulsion through a illter with small pores to remove additional emulsion particles; moving said interstitial member to present fresh surfaces to said emulsion; and moving the liquid through another portion of said interstitial mem ber after it moves through said filter means. 16. In combination in an electric separating device: a vstationary filter means; an interstitial electrically-conducting member in the form of a continuous belt-like member having -one side in front of said stationary filter means. said sta tionary filter means being positioned between op- ` posite sides of said interstitial member; means for movably mounting said interstitial member; means flowing a liquid containing suspended par ticles toward said interstitial member and thus tending to continue on to said ñlter means; means for establishing an electric field of uni directional character above said field of alter liquid moving toward said interstitial means; and means for moving said interstitial member to present new deposit-receiving surfaces to said . ` ~ 17. A method of separating a suspended ma terial from a liquid by use of a filter member providing an interstitial electrically-conducting surface, which method includes the steps of: moving the liquid with its suspended material toward said interstitial electrically-conducting nating character and into which moves at least a part of said mixture for separation of the sus surface; establishing an electric field adjacent pended material therein, said unidirectional and said alternating fields being in open communica of sumcient intensity to charge and project at " tion whereby the suspended material in said uni directional fleld drops to said field of alternating character._ _ 13. In combination in an electric dehydrator: a tank containing a dry-oil zone in the upper end thereof. the emulsion to be treated being in a lower emulsion zone of said tank; an interstitial cylindrical electrode in said dry-oil zone and bounding an electric field; means for moving material inward through the interstices of said 75 cylindrical electrode, at least a portion of said 45 filter means, said means including electrode means cooperating with said interstitial mem ber and establishing an electric ileld in said electric field. '12. In combination in an electrical treating system for mixtures: means setting up an elec-_ tric field of alternating character; means for cir culating the mixture to be treated in said field; aa' particles of said emulsion are deposited thereon means for electrically depositing a portion of pended material moving through said front por said particles on said interstitial member, the re tion of said movablejinterstitlal'memb‘er; >means " maining liquid moving through said stationary for moving said liquid toward said front portion' of said movable interstitial member and thence through said filter means and said other portion in succession; and means for withdrawing the puri?ed liquid which passes through said filter means and said other portion of said movablefin 26 emulsion' by the use of a belt-like interstitial said interstitial electrically-conducting surface least a portion of the suspended material from said surface in a direction away from this sur face; and collecting the liquid after it movœ through said filter member. ' t 18. A method of removing suspended impuri ties from a. liquid by-the use of a ñlter and cataphoretic action, which includes the steps of: 70 flowing a stream of said liquid containingsaid suspended impurities toward one side of said filter so that said liquid ñows therethrough; set ting up a uni-directional field of sufficient intensi ty and proper polarity immediately adjacent said 75 2,116,509 side of said ßltery to cause cataphoretic move ment of at least a part of said suspended impuri ties in said liquid away from said illter in a di rection generally opposed to the direction of flow of said liquid through said ñlter. `19. A method of removing suspended 'impuri ties from oil by the use of a ñlter and catapho 21. A combination as deiined in claim 1i in which said filter means is between and spaced from said portions of said movable interstitial member. 22. In combination in a treater for separating suspended material from a liquid: a tank con taining a body of said liquid; an interstitial 20. A method as defined in claim 1 involving the use of >a iilter plate toward which said liquid member movable in said body of liquid and pro viding front and rear portions spaced from each other; a ñlter between said portions of said movable interstitial member and receiving any liquid and unseparated suspended material mov ing through said front portion of said movable interstitial member; means for moving the liquid containing suspended material toward said front portion of said movable interstitial member and thence through said iilter means; walls defin ing a discharge chamber between said portions of said movable interstitial member and receiv ilows and including the step of moving said liquid through such ñlter plate immediatelyv after sub ing the purified liquid issuing from said nlter; and means for`conducting said purified liquid retic action, which includes the steps of: flowing a stream of said oil containing said suspended 19 vimpurities toward one side oi' said filter so that said oil flows therethrough; setting up a uni directional ileld of suillcient intensity and proper v polarity in said stream flowing toward said filter to cause cataphoretic movement of at least a portion of said suspended impurities in a direction opposite to the direction of movementof said stream and away from said ñlter. - v jection to said electric'fleld and as it continues its from said discharge chamber. movement toward said älter plate whereby> said electric field moves said suspended material -in a g5 direction away i'rom said filter plate. FREDERICK GARDNER CO’ITREIL. CERTIFICATE 0F QORREGTION. Patent No. 2,116, 509. FREDERICK GÀRDNER'COTTRELL. ' It is hereby certified that error appears inf-the printed specification of the above numbered patent requir ing correction as follows: Page 5, second column, line 10, claim 1h., after the 4win/fd “e1ectrode". insert asemicolon; _and that the said Letters Patent/.should be read with this correction therein that the'same' may conform tothe record vof the case in the Patent Office. Signed and sealed this 28th day‘of‘June, A. D. 1958. Henry Van Arsdale , (Seal) `Acting Commissioner of- Patents. 2,116,509 side of said ßltery to cause cataphoretic move ment of at least a part of said suspended impuri ties in said liquid away from said illter in a di rection generally opposed to the direction of flow of said liquid through said ñlter. `19. A method of removing suspended 'impuri ties from oil by the use of a ñlter and catapho 21. A combination as deiined in claim 1i in which said filter means is between and spaced from said portions of said movable interstitial member. 22. In combination in a treater for separating suspended material from a liquid: a tank con taining a body of said liquid; an interstitial 20. A method as defined in claim 1 involving the use of >a iilter plate toward which said liquid member movable in said body of liquid and pro viding front and rear portions spaced from each other; a ñlter between said portions of said movable interstitial member and receiving any liquid and unseparated suspended material mov ing through said front portion of said movable interstitial member; means for moving the liquid containing suspended material toward said front portion of said movable interstitial member and thence through said iilter means; walls defin ing a discharge chamber between said portions of said movable interstitial member and receiv ilows and including the step of moving said liquid through such ñlter plate immediatelyv after sub ing the purified liquid issuing from said nlter; and means for`conducting said purified liquid retic action, which includes the steps of: flowing a stream of said oil containing said suspended 19 vimpurities toward one side oi' said filter so that said oil flows therethrough; setting up a uni directional ileld of suillcient intensity and proper v polarity in said stream flowing toward said filter to cause cataphoretic movement of at least a portion of said suspended impurities in a direction opposite to the direction of movementof said stream and away from said ñlter. - v jection to said electric'fleld and as it continues its from said discharge chamber. movement toward said älter plate whereby> said electric field moves said suspended material -in a g5 direction away i'rom said filter plate. FREDERICK GARDNER CO’ITREIL. CERTIFICATE 0F QORREGTION. Patent No. 2,116, 509. FREDERICK GÀRDNER'COTTRELL. ' It is hereby certified that error appears inf-the printed specification of the above numbered patent requir ing correction as follows: Page 5, second column, line 10, claim 1h., after the 4win/fd “e1ectrode". insert asemicolon; _and that the said Letters Patent/.should be read with this correction therein that the'same' may conform tothe record vof the case in the Patent Office. Signed and sealed this 28th day‘of‘June, A. D. 1958. Henry Van Arsdale , (Seal) `Acting Commissioner of- Patents.