US1505104A - Electrochemical process of treating liquids - Google Patents

Description

Aug. 19 1924.

F. N. MOERK ELECTROCHEMICAL PROCESS OF TREATING LIQUIDS Filed March 23 1923 4 Sheets-Sheet 1 N wM M m g w m m aw M MN u w. a m I- a mm W mm m QN Aug. 19, 1924. 1,505,104

F. N. MOERK ELECTROCHEMICAL PR OCESS OF TREATING LIQUIDS Filed March 23 1923 4 Sheets-Sheet 2 I INVENTOR. I 1 /k M m Q 5i ATTORNEY.

Aug. 19 1924. r 1,505,104

F. N. MOERK ELECTROCHEMICAL PROCESS OF TREATING LIQUIDS Filed March 23 1923 4 Sheets-Sheet 3 mwm 151 A TTORNEY.

Aug. 19 1924. 1,505,104

F. N. MOERK ELECTROCHEMICAL PROCESS OF TREATING LIQUIDS Filed March 23 1923 4 Sheets-Sheet 4 21 lb 25 QIL 1 N VEN TOR. 7

7 ml. kw By M4525" 1 k ATTORNEY.

and other treatment tion prior to electrical treatment 0 time of admixture of the suspended solids and semi-solids 50 particularly when Patented Aug. 19, 1924.

PATENT OFFICE.

FRANK N. MOEBK, OF PHILADELPHIA, PENNSYLVANIA- ELECTROCHEMIGAL PROCESS OF TREATING LIQUIDS.

Application filed March 23, 1923. Serial No. 627,036.

T 0 all whom it may concern:

Be it known that I, FRANK N. MonnK, a citizen of the United States, residin in the city and county of Philadelphia, tate of 5 Pennsylvania, have invented new and useful Improvements in Electrochemical Processes of Treating Liquids, of which the following is a specification.

My invention relates to electro-chemical of liquids, such as industrial and potable waters, sewage, factory waste, eflluents from slaughter houses, tanneries and the like, for the purpose of effecting therein desired chemical or physical 15 changes, or both.

In accordance with one of the aspects of my invention, the liqixiid is subjected to electrical treatment in t e presence of suitable reagent added thereto and efi'ectin formaprecipitate or floeculent by reaction with contents of the liquid, the mixture of the reagent and liquid being effected under conditions whereby there elapses between the of reagent with liquid and the inception of the electrical treatment a period of time suited for and effecting complete diifusion of reagent throughout the liquid and sufiicing to effect 30 substantially complete reaction, the mixture being maintained in motion with a velocity which, particularl or preferably adjacent the point of efilux rom the mixing chamber, is sutliciently high to prevent sedimentation and fiocculent, and ensurin that they will pass with the liquid to the electrolyzing apparatus, whereby sedimentation may be effected after electrical treatment.

precipitate or In case the material added to the liquid to be treated is for the purposeof increasing ion concentration, whether or not reaction occurs, the maintenance of the mixture in motion for the suitable period of time is of importance to effect complete and uniform mixture and diffusion, and thereby prevent Stratification and non-uniformity while the li uid is undergoin electrical treatment.

urther in aocor anoe with my invention, the reagent is of a type which is a subdivided solid readily or sparingly soluble in water or other liquid with which it is to be supplied to the liquid to be treated, the reagent is mixed with suitable liquid under conditions efiecting a period of retention or time factor prior to introduction into the liquid to be treated sufiicient to effect eom lete or substantially complete or the desired de ree of solution, the reagent and liquid pre erably being at the same time maintained in motion with a velocity sufficiently high to revent settling or sedimentation of the solid reagent or any other solids present.

Further in accordance with my invention, the reagent, either in the form of a solution or subdivided solid, may, without the aforesaid retention eriod for effecting solution of the reagent, eintroduoed into the liquid upon contents of which it is to react, the reagent and liquid being retained in mixture with each other for a period of time sufficient to permit complete or substantially complete reaction while continuousl in movement at a velocity which, preferab y or particularly adjacent the point of etliux, is sufficiently high to prevent sedimentation of the precipitate or flooculent formed by the reaction,

the liquid with the fiocculent or precipitate suspended therein being thereafter retained quiescent or at reduced velocity suitable for sedimentation purposes.

My invention resides in paratus of the character scribed.

For an illustration of some of various modes of practicing my invention, and for an illustration of some of the forms my apparatus may take, reference may be had to the accompanying drawings, in wh ch:

Fig. 1 1., a vertical sectional view, some parts in elevation, of apparatus embody ng my invention and utilizable for practicing my method.

Fig. 2 is a top plan view of part of the ap aratus illustrated in Fig. 1.

ig. 3 is a diagram, parts shown in plan, of a system for the practice of my invention.

Fig. 4 is a fragmentary diagrammatic view of a circuit arrangement utilizable in the electrolyzing apparatus.

Fig. 5 is a vertical sectional view, some parts in elevation, of apparatus embody ng my invention and utilizable for practic ng my method without recourse to electrical treatment.

'Fig. 6 is a vertical sectional view, parts in elevation, of a water softening system involving features of my invention.

hereinafter de- Fig. 7 is a vertical sectional yiew, and Fig. 8 a top plan view, of a modified form of mixing apparatus.

Referring to Fig. 1, there may be utilized in accordance with my invention mixing a paratus or a mixing chamber M in which e operation of mixing involves a substantial period of retention or efiecting com lete diflusion and inter-mixture, and w ich, when there are solids or semi-solids in the raw liquid or produced therein by reaction, efl'ects movement of the mixture at such velocity that the solids and semi-solids are prevented from sedimentizing or settling out and are maintained in suspension in the liquid as it flows from the chamber M. The liquid is delivered from the chamber M to electrical a paratus E for electrol zing or otherwise e ectrically treating liquid in turn delivering the treated liquid to any suitable destination as a stream or, as indicated, to a receptacle s, which may be a sedimentation basin or tank, from which the etlluent is discharged to stream or to any suitable or desired destination if the liquid is to be retained or further operated upon.

In Fig. 5 the apparatus for effecting electrical treatment is omitted, and the apparatus or chamber M may discharge to stream or other suitable destination, or, as indicated, to a receptacle S,'which may be a sedimentation basin or chamber, from which the eflluent is discharged to a stream, or to any other suitable destination if the liquid is to e reserved or further operated upon.

11 Fig. 6, apparatus for efi'ecting electrical treatment is omitted; a series of mixing apparatus is employed for efiectin them a reaction or efl'ect of suita l le character, with suitable retention period and motion to prevent sedimentation, the eflluent being delivered to the next mixing apparatus of the series, wherein a further or difi'erent reaction or eii'ect is produced, with suitable retention period and motion to prevent sedimentation, the ultimate efliuent from the last mixin apparatus of the series being delivene ly to stream, or,

a sedimentation basin or tan S.

In both Figs. 1, 5 and 6, when the material or reagent to be added to the li uid is supplied in the ivided or tus D, which, for

dissolving chamber or a paratus, and which is preferably emplo ed? particularly when the operation of e ecting solution or suspension of the material or reagent involves r best efl'ect an appreciable period of time. t

For one example of the structure of the dissolving ap aratus in accordance with my invention, re erence may be had to Fig. 1, wherein 1 is a horizontal trough, shown in as indicated,

through vertical section, longitudinally of which extends the shaft 2, rotated by an suitable means, and to which is secured t e helical conveyer structure 3, which advances the solid material or rea ent in subdivided or powdered form, to tfie c ute 4, delivering into the conduit 8 dis osed in conveying chamber 5 into which is delivered tangentiall by the ipe 6, controlled by valve 7, the liquid with which the solid material or reagent is to be mixed or in which it is to be dissolved. Ordinarily, this liquid is water, and may be water or sewa e for some of the rocesses hereinafter escribed. The liqui accordingly takes a circular path the chamber 5, and the mixture of material or reagent with liquid overflows the upper edge of the conduit 8- which discharges into the trough 9. As indicated, the apparatus comprising the members 1 to 8 inclusive may be duplicated for simultaneous or alternate use.

e mixture of material or reagent with liquid flows downwardly from the trough 9 through the down-take chamber or conduit 10 into the conical bottom portion 11 of the uptake chamber or tank 12, delivering into the weir box 13 having the weirs 14 provided with through which the solution overflows into chambers 16, from which the solution is distributed through suitable pipes, hereinafter referred to.

Delivering tangentially into the conical bottom structure 11 is a pipe 17, controlled by valve 18, delivering suitable liquid, for

by pipe 6, for adding at suitable rate additional liquid for effecting suitable de e of saturation of the solution eventua ly delivered to the compartments 16.

The conical bottom chamber 11 is rcvided with a draw-oil outlet 19, contro led by valve 20, for emptying the chamber 12 when desired.

he liquid in passing downwardly throu h the chamber 10 and u wardly through t a chamber 12 efi'ects so ution or suspension of the added solid material or reagent, the li uid artaking in the chambers 11 and 12 oi s. w irling or helical movement which increases the length of path traversed and the time of retention wit in the dissolving apparatus. The time of retention or time actor is of importance in efl'ectin suitable or desired degree of saturation 0 solution, and may be, in case there is fed through the passage 4 finely divided or powdered quickime or'hydrated lime for sewage treatment as hereinafter descri as much as ten or welve minutes, for example, and is preferably of the order of four or five minutes.

The introduction tangentially of liquid the pipe 17 serves to effect such whirling or vortex action as to prevent same character delivered lodgment or settling of any solids or semisolids which may exist or be produced in the liquid passing through the apparatus.

Dissolving apparatus as above described makes possible economical application of a dry or solid reagent, whose rate of introduction may be varied by varving the speed of rotation of the shaft 2. The operation of mixing material or reagent with liquid is continuous and effects a retention period or time factor requisite for producing suspensions or solutions of desired densities or saturations without waste of added material or reagent. The velocity of flow is such, particularly where direction of flow changes, as to prevent collection or sedimentation of solids or semi-solids. The counter-current flow, as provided by the inner and outer chambers 10 and 12, effects increase in the length of path of flow, and conserves space by effecting smaller over-all dimensions of the apparatus. B provision of a plurality of discharge cham ers, as 16, the liquid containing the added material or reagent in suspension or solution may be divided into any suitable number of streams, which may be distributed to separate and distinct points of application.

The mixing apparatus M comprises a cylindrical or otherwise suitably shaped tank or chamber 21 having the tapered or conical bottom chamber 22. The li uid to be treated, as water, sewage-or the lite, is introduced through the pipe 23 terminating at 24 within the chamber 21 adjacent its upper end in position to effect tangential delivery, the pressure upon the liquid delivered by the pipe 23 being sufficient to induce a whirling or vortical movement, as indicated by the line 25, downwardly through the chamber 21 into the conical chamber 22.

The velocity of the liquid is preferably high enough to prevent any solids or semisolids in or produced within the liquid from collecting upon or adjacent the side Walls of the chambers 21 and 22. The velocity in the chamber 22 increases because of its decrease in diameter, and preferably to such extent that at or adjacent the inlet 26 of the discharge pipe or conduit 27 it attains its maximum. The material or reagent in suspension or solution in liquid is delivered through the pipe 28, controlled by valve 29, adjacent the outlet 24 of the conduit 23, whereby the two liquids come immediately into contact or mixture with each other as they enter the chamber 21. The liquid delivered through the pipe 28 may be that delivered from a compartment 16 of the apparatus D through a pipe 30, controlled by valve 31.

Or otherwise previously prepared suspension or solution of material or reagent in liquid may be delivered from the tank '1 through the pipe 32, controlled by valve 33,

to the pi e 28.

Throug a ipe connection 34, controlled by valve 35, t e pipe 28 connects with the pipe 23 external to the chamber 21, whereby the liquid containing material or reagent 1n suspension or solution may be delivered into liquid to be treated in advance of its discharge into the chamber 21. Or with both valves 29 and 35 open, the added material may be introduced both into the pipe 23 and adjacent its outlet 24.

hen the liquid passing downwardly through the chamber 21 and outwardly through the pipe 27 contains or has formed or produced therein solid or semi-solid material, the latter is prevented from collecting in either of the chambers 21 or 22, and the velocity adjacent the inlet 26 of the pipe 27 is of such magnitude as to cause all 0 the solids or semi-solids to be carried off with the liquid through pipe 27.

The length of the path of the fluid in the chambers 21 and 22 and its velocity is such that there is effected a suitable time factor or retention period which, when calcium hydroxide is utilized, as, for example, in the hereinafter described process of treating sewage, may be, for example, as much as ten or twelve minutes, and is preferabl of the order of five minutes, and may be 0 the order of two minutes for maximum rate of flow.

This retention period or time factor ensures sufficient or substantially complete diffusion of the added material or reagent throughout the liquid to he treated, and the structure affords sufficient time for substantial completion or desired degree of completion of reaction between the added material and contents of the liquid to be treated.

Mixing apparatus of the character described is continuous as to its operation; effects uniform mixture of the added material or reagent with the entire volume of liquid to be treated, and effects economy in the amount of reagent utilized for a given purposegprevents sedimentation: and effects increased velocity of flow at or adjacent the discharge to prevent sedimentation. \Vhen the reaction produces a coagulant or flocculent, substantially none of it collects or remains in the mixing apparatus, but is carried off with the liquid and is available in its entirety for subsequent use, as in the sedimentation basin. By location of the discharge at the bottom of the mixing chamber, the apparatus operates as a grease trap. causing separation of the lighter materials, such as grease, scum, froth, etc., which rises to the top where it may be removed.

The discharge pipe 27 delivers to the electrolyzing apparatus E, which may be of any type or character suitable to the process involved.

with As indicated in Figs. 1 and 4, it may comprise a plurality of banks or roups of electrodes connected in series with each other, each group or bank com risin positive electrodes p and negative e ectro es n, between which may be disposed movable agitating or paddle members a. Direct current is supplied by any suitable source, as, for exam ple, a dynamo-electric generator whose armature is G, connected in circuit with the electrdc banks and, if suitable or desirable, with the variable resistance r. The field winding f of the generator receives current from any suitable source, as from the current supply conductors s, the field excitation bein controllable by the variable resistance 1". he source a may be the armature G itself, in which case the generator-is self-exciting. However, separate excitation, as indicated, may be employed.

Electrolyzing apparatus .of the foregoing character is disclosed in. Letters Patent No. 1,139,778, to Landreth, for utilization in a process an improvement upon which is one of the feature of the present invention.

As indicated in Fig. 1, the electrodes are disposed within a chamber 37, receiving the liquid from the pipe 27 which passes in succession between the electrodes of the successive banks of groups and is discharged through the outlet pipe 38, which may deliver to a stream, or, as indicated, to a sedimentation basin or chamber S, from which the eflluent is discharged at 39 to a stream or to other destination when the treated li uid is to be further operated upon.

en the aforesaid dissolving apparatus D is employed, there may be rovided a ipe 40, controlled by valve 41, dialivering 50m one of the compartments 16 of the apparatus D into the pipe 27 beyond the mixing apparatus M and in advance of the electrolyzmg apparatus E, whether or not the mixing apparatus M be employed. For adding material or reagent to the liquid in the settling tank or basin S, when suitable or desirable, as, for example, in accordance with the aforesaid Landreth process, there is provided a pipe 42, connecting through pipe 30 with a compartment '16 of the apparatus D, and delivering, under control of the valve 43, into the settling tank or basin S.

The'basin or tank S may have, is indicated, a conical bottom 44, in which collects the solids and semi-solids, preci itate and flocculent, which may be drawn 0 from time to time throu h the sludge draw-ofi' controlled by the valve 46,

e arrangement of apparatus in accord- Figs. 1 and 3 may be, and prefw is, suchthat the liquid flows from apparatus D to the mixing apparatus M by gravity, and flows by vity from the apparatus M to and through the electrol zer apparatus E to the sedimentation tank S,

whose outlet 39 is at a sufliciently low level allow esca e of the efiiuent by gravit In Fig. 3 t e arran ement is in princip e the same as that of ig. 1, except that a plurality of electrolyzers E is served by the same apparatus D and M and delivered to the same or individual settling basins or chambers S.

In accordance with my invention, sewage or the like, containing bacteria and oxidizable organic matter, and putrescible or putrescent solids or semi-solids may be treated in general in accordance with the Landreth process of the aforesaid Letters Patent No. 1,139,778, as modified or improved by the efi'ect of the mixing apparatus, or the mixing apparatus in conjunction with the dissolving apparatus.

Suitable reagent, as calcium oxide or guicklime, or hydrated lime or calcium hyroxide, in subdivided or powdered solid form or other suitable hydroxide or caustic, is fed into the dissolving apparatus D, Fig. 1, where it comes into contact with water supplied through either or both pipes 6 and pipe 17, or in lieu of water, there may be introduced through "any one or more of these pipes sewage, preferabl strained, a part of that to be treated. There is accordin ly effected a solution of hydroxide, preferably calcium hydroxide, during aretention period eifecting a time factor for procurin the beneficial efi'ects hereinbefore describe The calcium or other hydroxide solution is delivered into the mixing a paratus M, where the mixture is retained or a eriod effecting complete difi'usion and su stantially complete reaction, as hereinbefore described. The calcium hydroxide reacts with contents of the sewage to produce a flocculent precipitate or coagu ant consisting mainly of calcium carbonate, the precipitate and the solids and semi-solids contained in the sludge being prevented, however, from sedimentation, as hereinbefore described. The sewage, which has so been preliminarily treated by effecting chemical reaction of the added calcium hydroxide with contents of the sewage, is delivered to the electrolyzing a paratus in such state that it contains, a r the aforesaid reaction, free, as distinguished from combined, alkali. In its passage through the electrolyzing apparatus the free alkali (hydroxide) assists in the production of nascent oxygen by electrolysis, the free alkali being preferably present in ipliantity suflicient to prevent attack u on t e positive electrodes of iron or the like, and to ensure free alkali in the effluent, in accordance with said Landreth process.

The solids and semi-solids, as well as the bacteria and organic matter in solution, are oxidized and rendered harmless and nontrescent, and the mixture is then delivered 'rectly to stream or to the sedimentation agent-dissolvin basin S, where the solids, sludge and coagulant settle into the bottom 44, from which they are drawn off from time to time through the sludge draw-off 45' and the clarified liquid, as the effluent, is ischar ed through the outlet 39 to stream or to ot er suitable destination.

Reagent may be also delivered through the pipe 40 to the pipe 27 and through the pipe 42 to the sedimentation basin S, in accordance with said Landreth process.

By utilization of the mixing apparatus M as described, the reaction between the calcium hydroxide and contents of the sewage is well under wa or substantially complete before the liqui reaches the electrolyzer E, and the precipitate resulting from the reaction flows through the electrolyzer E substantially unchanged, the velocity through the electrolyzer being sufficient to prevent substantial sedimentation therein.

By utilization of my mixing operation, or such operation in conjunction with the reoperation, both involving retention peri s, it is found that the amount of lime or other reagent necessary to effect suitable electrical and subse uent treatment of the sewage is materially ecreased.

For example, where heretofore the sewage before entrance into the electrolyzer has had add-ed thereto calcium hydroxide in the proportion of about 150 parts per million, by my method the amount of calcium hydroxide may be reduced to about 75 parts per million, or a saving of approximately one-half. This saving is in part due to the fact that because of the period of retention in the mixing apparatus M the mixture or diffusion of the reagent with or through the sewage is so complete and uniform that there is little or no Stratification within the electrolyzer E, such stratification having been the cause of too small amounts of free alkali locally or in certain regions in the electrolyzing apparatus, resulting in insufiicient treatment and in some cases attack upon electrodes in localized regions. The effects of such stratification have necessitated the use of greater amounts of reagent to ensure that in all parts of the apparatus there should be at least the minimum amount of free alkali essential to the process.

Furthermore, by recourse to the preliminary operation efi'ected by the mixing apparatus t e coagulant, flocculent or precipitate, as well as any contained solids or semisolids, is thoroughly mixed and diffused throughout the mass of the sewage, whereby upon reaching the settling tank or basin there does not occur Stratification within the tank or basin, with the result that its operation is more complete and efiicient. and it is not necessary, as in some cases of prior practice, to utilize a portion of the sedimentation basin or tank structure for overcoming stratification or non-uniformity of distribution of the reagents or flocculent or coagulant.

The velocity maintained in the mixing apparatus is also of advantage in preventing sedimentation, as described, with the result that not only the formed flocculent or precipitate is carried along to the electrolyzer, but sedimentation or settling of the putrescent or putrescible solids or semi-solids of the sewage is also prevented, all being transferred to the electrolyzing apparatus, where the are rendered non-putrescent.

y preference, the time factor or retention period of the mixing operation in advance of the electrical treatment is several times the retention period or time factor of the traverse of the electrolyzing apparatus by the sewage. For example, the time elapsing frominception to completion of the electrical treatment may be of the order of one or two minutes, while the period of retention of the sewage in the mixing apparatus is of the order of four or five minutes, though it may be less or greater. By preference, the retention period in the dissolving apparatus D is of the order of four or five minutes, when a solution of calcium hydroxide is to be effected, though it may be less or greater.

Where it is desirable to subject the sewage to hypochlorite treatment, sodium chloride may be fed to the dissolving apparatus D to effect its solution and then delivered into the mixing apparatus M; or a sodium chloride solution may be delivered from the tank T into the ap aratus M; or sodium chloride in powdere form may be delivered into the apparatus M through the conduit 36. By the action of the mixing apparatus, the sodium chloride is thoroughl and uniformly diffused throu hout t e continu ously passing stream 0 sewage, preventing stratification within the electrolyzing apparatus E, wherein, in the presence of carbon or other non-attackable electrodes, especiall positive electrodes, hypochlorite is pro need for germicidal and other action upon the sewage, which after treatment is delivered to the sedimentation basin S as in the previously described process, or directly to stream.

The beneficial effects of the retention period and prevention of sedimentation of my mixing operation, or the same in combination with the operation of the dissolving apparatus, may be utilized in processes which do not invlove electrical treatment.

For example, in Fig. 5 the mixing apparatus M discharges to the sedimentation basin or tank S, without utilization of electigicall treating apparatus, such as E of or example, water, destined for municivents stratification in the pal su ply purposes, may be treated with alum, For clarifying the water in advance of filtration or in advance of use without filtration.

Powdered or finely divided alum may be fed into the apparatus D, where it. comes into contact with Water, either previously treated or a portion of the raw water to be treated. The alum solution is then fed to M, as through either pipe 28 or 34, or both. r an alum solution may be delivered from the tank T to the apparatus M, in which case the dissolving apparatus D ma be dispensed with.

n the apparatus M alum reacts with the carbonates or bicarbonates contained 'in the raw water to produce a coagulant or flocculent precipitate of aluminum hydroxide whic together with other finely divided solids in suspension in the raw water and causing turbidity, due to the velocity maintained in the apparatus M, is prevented from sedimentation therein, the water with its contained flocculent and suspended solids and semi-solids being delivered into the sedimentation tank or basin S, where the flocculent settles and sedimentizes or carries down with it the finel divided solids and matter in the liquid, tliereby clarifying it. The clarified liquid is discharged throu h the outlet 39 either directly to point of uti ization or, and generally, t0 a filter. The sludge or sediment is drawn oil' from time to time through the sludge outlet 45. By the sedimentation eflected as described, the capacity of and load'lgpon the filtering apparatus is reduced. ere again the operation of the mixing apparatus is such as to thoroughly and completely diffuse the alum throughout the raw water, and the time of retention is such as to effect complete or substantially complete reaction within the mixing ap aratus, before delivery to the settling basin. Furthermore, the complete diffusion or distribution of the fiocculent and solids throughout the water in advance to the sedimentation tank presettling basin, with the result that there need not be provided therein or in connection therewith the usual structure for overcoming stratification or non-uniform distribution of the suspended flocculent and solids.

the apparatus The benefits of either or both of my mix ing and dissolving operations may be availed of also in processes or systems forsoftening water.

As indicated in Fi 6, a caustic such as quicklime orhydrating lime in subdivided or powdered form is delivered to the dissolving apparatus-D to eflect a solution of calcium hydroxide, which is delivered into the mixing apparatus M, to which is delivered also throug the pipe 23 the water to be softened. The calcium hydroxide reacts with. the com- 'wi be understood that bined and half-combined carbonic acid, as bicarbonates, in the water, producing a precipitare of calcium carbonate. This reaction efl'ects removal or reduction of the soealled temporary hardness, and the liquid so treated, with the preci itate in suspension therein, and which has n prevented from settling in the apparatus M, is delivered to the second mixing apparatus M, where it again partakes of the vortical movement with admixture of a solution of sodium carbonate or soda ash which may be produced in the second dissolving apparatus D to which is fed finely divided or powdered soda ash. In the apparatus M the sodium carbonate or soda ash reacts with such salts, as calcium sulphate of calcium carbonate in addition to that efl'ected in the first mixing apparatus M. The precipitates are prevented from sedimentizing, and are ke t in suspension in the treated water, whic is. their delivered to a sedimentation basin or tank S, where clarification and sedimentation takes place, the sediment being drawn oil from time to time through the draw-oil 45, and the clarified water drawn ofl' through the outlet 39,"to a filter, and thence to its destination of use, or directly thereto without filtering, when suitable or desirable.

In Figs. 7 and 8 is shown a modified form of mixing ap aratus comprising the mixing tank or cham r M, having the upstandi conical bottom 47, between whose base an the wall of the chamber M is the inlet port 24 forming the discharge of the pipe 23, which delivers the se age or other liquid to be treated tangentiall as indicated in Fig 8, into the space between the conical bottom 47 and the side wall of the chamber M. The liquid containing insuspension or solution the added material or reagent is delivered by the pipe 28, whose discharge outlet is adjacent the aforesaid outlet 24. The liquid accordingly pal-takes of a vortical movement u wardly through the chamber M, and is discharged ta entiall through the discharge outlet 26 of t e disc r conduit 27*, delivering as before to an e ectrolyzer or other electrical treating apparatus,

or directly to a sedimentation basin or tank S. In this case again the mode o'f-operation is in general that of the above de scribed apparatus M, suitable time factor or retention period being provided, with velocities of flow preventin sedimentation.-

W'h-ile separation o the precipitate or solids and (or) semi-solids from the liquid may be effected b sedimentation and is generally or referab y eifected by sedimentation, it other well known methods of separation ma be resorted to in lieu of sedimentation, as, or example, filtration, centrifugal action and the like. In the forms ofmy invention involving electrical treatment the presence of precipitate in the liquid during electrical treatment is of advantage both from the aspect of facilitating clarification or separation by sedimentation or filtration, and from the aspect, particularly when the liquid is to be discharged directly to stream, of avoidin need for precipitate collection or draw oli in the mixing chamber, or, in general, in advance of or during electrical treatment.

What I claim is:

1. The method of treating liquid, as sewage, water, etc., which comprises introducing into the liquid a rea ent producing with a content of the liqui a precipitate, thereafter electrical] treating the liquid in the presence of said precipitate, and thereafter clarifying said liquid by sedimentation.

2. The method of treating liquid, as sewage, water, etc., which comprises introducing into the liquid a material increasing the ion concentration thereof, maintaining said liquid and the added material in motion for a retention period to effect difi'usion of the added material in said liquid to prevent Stratification in its subsequent treatment, and thereafter electrically treating the li uid.

3. The method of treating liquid, as sewage, water, etc., which comprises continuously passing liquid between electrodes between which current is passing for electrical treatment of the liquid, continuously adding to the liquid prior to its electrical treatment a material increasing its ion concentration, and maintaining said liquid and the added material in motion for a retention period prior to electrical treatment greater than the period of electrical treatment.

4. The method of treating liquid, as sewage, water, etc., which comprises adding to the li uid a material reacting with a content o the liquid to produce a precipitate, maintaining the liquid and the added material in motion for a retention period efl'ecting approximately complete reaction, and thereafter electrically treating the liquid with said precipitate in suspension therein.

5. The method of treating liquid, as sewage, water, etc., which comprises adding to the liquid a material reacting with a content of the li uid to produce a preci itate, maintaining the liquid and the adde material in motion for a retention period effecting approximately complete reaction, thereafter electrically treating the liquid with said precipitate in suspension therein, and thereafter subjecting the liquid to sedimentation.

6. The method of treating liquid, as sewage, water, etc., which com rises adding to the liquid an excess of material reacting with a content of the liquid to produce a preci itate, maintaining the liquid and the ad ded material in motion for a retention period efi'ecting approximately complete reaction, and thereafter passing electric current through said liquid in the presence of the excess of said added material and in the presence of said precipitate.

7. The method of treating liquid, as sewage, water, etc., which comprises adding to the liquid an excess of material reacting with a content of the li uid to produce a precipitate, maintaining t e liquid and the added material in motion for a retention period efi'ectin approximately complete reaction, therea ter assing electric current through said liqui in the presence of the excess of said added material and in the presence of said precipitate. and thereafter subjecting the treated liquid to sedimentation.

8. The method of treating liquid, as sewage, water, etc., which comprises adding to the liquid a material reacting with a content thereof to produce a recipitate, maintaining the liquid and ad ed material in whirling movement to maintain the precipitate in suspension, and thereafter passing electric current through said liquid in the presence of said precipitate in suspension.

9. The method of treating liquid, as sewage, water, etc., which comprises adding to the liquid a material reacting with a content thereof to produce a recipitate, maintaining the liquid and adc ed material in whirling movement to maintain the precipitate in suspension, thereafter passing electric current through said liquid in the presence of said precipitate in suspension, and thereafter subjecting the treated liquid to sedimentation.

10. The method of treating liquid, as sewage Water, etc., which comprises continuously passing the liquid between electrodes for passage of current therethrough, adding to the liquid in advance of the electrical treatment a material reacting with a content of the li uid to roduce a precipitate, maintaining t e liquid, added material and precipitate in whirling movement for a retention period for effecting approximately complete reaction, maintalning the precipitate in suspension during said retention period, and passing it while continuing in suspension in said liquid between said electrodes.

11. The method of treating liquid, as sewage, water, etc., which comprises continuously passing the liquid between electrodes for passage of current therethrough, adding to the liquid in advance of the electrical treatment a material reacting with a content of the liquid to roduce a precipitate, maintaining the liquid, added material and precipitate in whirling movement for a retention period for effecting approximatel complete reaction, maintaining the precipitate in suspension during said retention period, passing it while continuin in suspension in said liquid between sai electrodes,

and thereafter subjecting the treated liquid to sedimentation.

12. The method of treating liquid, as sewage, water, etc., which comprises adding to the liquid free alkali reacting with a content thereof'to produce a flocculent preci itate, intermixing the added material and iquid for a retention period efiecting substantially complete reaction, and thereafter passin electric current through the liquid with sai precipitate in suspension.

the excess of free alkali and in than said retention period.

13. The method of treating liquid as sewage, water, etc., which comprises adding to the liquid free alkali reacting with a content thereof to produce a flocculent precipitate, intermixing the added material and liquid for a retention period effecting substantially complete reaction, thereafter passing electric current through the liquid with said precipitate in suspension, and thereafter sedimentizing the treated liquid by said flocculent precipitate.

14. The method of treating liquid, as sewage, water, etc., which comprises adding to the liquid free alkali reacting with a content thereof to produce a flocculent recipitate, maintainin the liquid and ad ed material in motion for a retention period efi'ect' ing approximately complete reaction and maintaining the precipitate in suspension, and thereafter assing electric current through the liquid with said precipitate in suspension therein.

15. The method of treating liquid, as sewage, water, etc., which comprises adding to the liquid an excess of free alkali reacting with a content thereof to produce a precipitate, maintaining the precipitate in suspension in said li aid, and thereafter passing current throug the liquid in the resence of the excess of free alkali and in t e presence of the preci itate in sus ension.

16. The metho of treating iquid, as sewage, water, etc., which comprises adding to the liquid an excess of free alkali reacting with a content thereof to produce a precipitate, maintaining the preci itate in suspenw sion in said 11 uid, thereafter passing current through t e liquid in the resence of e presence of the precipitate in suspension, and thereafter sedimentizing the treated liquid.

17 The method of treating liquid, as sew age, water, etc., which comprises adding to the liquid free alkali reacting with a content thereof for producin a flocculent recipitate, maintaining thediquid and added material in motion for a retention period effecting approximately complete reaction and maintaining the precipitate in suspension, and thereafter passin electric current through the liquid with said precipitate in suspension therein for a period shorter 18. The method of treating liquid, as sewa e, water, etc., which comprises adding free through the liquid with the precipitate in suspension therein and in the presence of the excess alkali an electric current of such strength and inthe presence of positive electrodes of iron for effecting oxidation without substantial consumption of said electrodes. 1

19. The method of treating liquid, as sewage, water, etc., which comprises adding free alkali to the liquid inexcess for reacting with a content 0 the liquid to produce a recipitate, maintaining said liquid, adde alkali and precipitate in motion for a retention period c plete reaction and maintaining the precipitate in suspension, and thereafter passing through the liquid with the precipitate in suspension therein and in the presence of excess alkali an electric current for effecting oxidation, the addition of said alkali being in quantity sufiicient to ensure free alkali 1n the li uid after said electrical treatment.

20. he method of treating liquid, as sewa water, etc., which comprises adding free a ali to the liquid in excess for reacting with a content of the liquid to produce a precipitate, maintaining said liquid, added alkali and recipitate in motion for a retention perio efiecting approximately complete reaction and maintaining the precipitate in suspension, thereafter passing through the liquid with the precip ate in suspension therein and in the presence of excess alkali an electric current for efiecting oxidation, the addition of said alkali being in uantity suflicient to ensure free alkali in the iquid after said electrical treatment, and thereafter efl'ectin sedimentation of the treated liquid by said precipitate in the presence of the free alkali.

21. The method of treating liquid, as sewage, water, etc., which comprises continuousl adding to a continuously flowing liquid material in solid form to effect a solution thereof, maintaining said li uid in motion for a retention period for e ecting approximately complete solution of said material, thereafter adding the solution to the liquid to be treated, maintaining the liquid and the added solution in motion for a retention period elfecting approximately complete intermixture, and thereafter subjecting the mixture to further treatment.

22. The method of treating liquid, as sewage, water, etc., which comprises continuously adding to a continuously flowing liquid material in solid form to efiect a soluecting approximately com-v tion thereof, maintaining said liquid in motion for a retention period for effecting approximately complete solution of said material, thereafter adding the solution-to the liquid to be treated, maintaining the liquid and the added solution in motion for a retention period efl'ecting approximately complete intermixture, and thereafter passing current through the liquid.-

23. The method of treating liquid, as sewage, water, etc., which comprises continuously adding to a continuously flowing liquid material in solid form to effect a solution thereof, maintaining said liquid in motion for a retention period for effecting approximately complete solution of said material, thereafter adding the solution to the liquid to be treated, maintaining the liquid and the added solution in motion for a retention period effecting approximately complete intermixture, thereafter passing current through the liquid, and thereafter subjecting said liquid to sedimentation.

24. The method of treating liquid, as sewage, water, etc., which comprises continuously adding to a continuously flowing liquid material in solid form to effect a. solution thereof, maintaining said liquid in motion for a retention period for effecting approximately complete solution of said material, thereafter continuously adding the solution to a continuously flowing stream of the liquid to be treated, the solution reacting with a content of the liquid to be treated to produce a precipitate, maintaining the liquid to be treated and the added solution in motion for a retention period for eifecting ap proximately complete reaction, and there after delivering the liquid with the precipitate continuing in suspension therein to a region in which it is quiescent for effecting sedimentation.

25. The method of treating liquid, as sewage, water, etc., which comprises continuously adding quicklime or hydrated lime in divided solid form into a continuously flowin liquid to effect solution thereof, maintainin said liquid and the added material in motion for a retention period efl'ecting an approximately saturated solution of calcium hydroxide, continuously delivering the hydroxide solution into a continuously flowing stream of the liquid to be treated, the calcium hydroxide reacting with a content of the liquid to produce a precipitate, maintaining the liquid to be treated and the added hydroxide solution in motion for a retention period efiecting ap roximately complete reaction. and therea ter passing electric current through the liquid with said precipitate continuing in suspensiontherein.

26. The method of treating liquid, as sewage, water, etc., which comprises continuously adding uicklime or hydrated lime in divided solid form into a continuously flowing liquid to elfect solution thereof, maintaining said liquid and the added material in motion for a retention period efl'ectin approximately saturated solution of ca cium hydroxide, continuously delivering the hydroxide solution into a continuously flow-' ing stream of the liquid to be treated, the calcium hydroxide reacting with a content of the liquid to produce a precipitate, maintaining the liquid to be treated and the added hydroxide solution in motion for a retention period effecting approximately complete reaction, thereafter passing electric current through the liquid with said pre cipitate continuing in suspension therein, and thereafter subjecting the treated liquid to sedimentation.

27. The method of treating liquid, as sewage, water, etc., which comprises continuously adding to a continuously flowing stream of liquid a chloride, as sodium chloride or uivalent, soluble therein, maintaining the iquid and the added chloride in motion for a retention period effecting approximately complete solution of the chloride, and continuously passing the liquid and chloride in solution therein between electrodes between which current is passed for producing hypochlorite.

28. The method of treating liquid, as sewage, water, etc., which comprises continuously adding, to a continuously flowin stream of the liquid to be treated a materia reacting with a content thereof to produce a precipitate, maintaining the liquid and added material in motion for a retention period effecting approximately complete re action, and continuously drawing oil the liquid with the precipitate in suspension therein to a region of quiescence for effecting sedimentation.

29. The method of treating liquid, as sewage, Water, etc., which comprises continuously adding a reagent in subdivided solid form into a continuously flowing stream of liquid for effecting solution of the reagent, maintaining the liquid and reagent in motion for a retention period effecting approximately complete solution, continuously delivering the solution into a continuously flowin stream of the liquid to be treated, the hquid having a content reacting with the reagent to roduce a preci itate, maintaining the liquid to be treate and the reagent in motion for a retention period effecting approximately complete reaction and maintaining the precipitate in suspension, and continuously drawing off the liquid with the precipitate 1n suspension therein to a region of quiescence for effecting sedimentation.

30. The method of softening water, which comprises continuously adding a caustic to a. continuously flowing stream of the water to be treated, the caustic reacting with a content of the water to produce a precipitate, maintaining the water and reagent in motion for a retention period efiectlng approximately complete reaction, continuously drawin ofl the water with the precipitate continuing in suspension therein, thereafter adding to the water a suitable reagent, as sodium carbonate or equivalent, reacting with a content of the water to produce a second precipitate, maintaining the water with the contained precipitate and second reagent in motion for a retention period effecting approximately complete reaction, and continuously drawing off the water with both precipitates continuing in suspension to a region of quiescence for effecting sedimentation.

31. Liquid treating apparatus comprising an electrolyzer, a mixing tank, means for delivering the liquid to be treated into said tank, a draw-ofi' delivering from said tank to said electrolvzer, means for delivering a material into the liquid to be treated, and means for impartin to the li uid in said tank a circuitous pat between t e inlet and said draw-off for effecting a suitable period of retention.

32. Liquid treating apparatus comprising an electrolyzer, a mixing tank, means for delivering the liquid to be treated into said tank, a draw-off delivering from said tank to said electrolyzer, means for delivering a material into the liquid to be treated, and means for imparting to the liquid in said tank a circuitous path terminating adjacent said draw-off in a formation effecting high velocity, whereby the liquid is retained in said tank for suitable period and carries to said draw-ofl matter in suspension therein.

33. Liquid treating apparatus comprising dissolving apparatus, means for delivering liquid thereto, means for delivering thereto a material to be brought into solution. the length of the path of the liquid within said apparatus being such as to effect a period of retention, a mixing tank, means for delivering the liquid to be treated into said tank, an electrolyzer, a draw-off from said tank delivering to said electrolyzer, means for delivering a solution from said first named apparatus into the liquid to be treated, and means for imparting to the liquid in said tank a circuitous path between the inlet and said draw-0E for effecting a suitable period of retention.

34. Apparatus for treating liquid comprising a mixing tank, means for delivering the liquid to be treated into said tank, a sedimentation structure, a draw-0E delivering from said mixing tank to said sedimentation structure, means for delivering a material into the liquid to be treated, and means for impartin to the li uid in said tank a circuitous pat between t e inlet and said draw-ofl' for eifecting a suitable period of retention.

35. Liquid treating apparatus comprising dissolving apparatus, means for delivering liquid thereto. means for delivering thereto a material to be brought into solution, the length of the path of the liquid within said apparatus being such as to effect a period of retention, a mixing tank, means for delivering the liquid-to be treated into said tank, and means for delivering the solution from said dissolving apparatus into the liquid to be treated, a draw-off delivering from said tank. and means for impartinlg1 to the liquid in said tank a circuitous pat between the inlet and said draw-off for effecting a suitable period of retention.

36. Liquid treating apparatus comprising dissolving apparatus, means for delivering liquid thereto, means for delivering thereto a material to be brought into solution, the length of the path of the liquid within said apparatus being such as to effect a period of retention, a mixin tank, means for delivering the liquid to e treated into said tank. means for delivering the solution from said dissolving apparatus into the liquid to be treated. a sedimentation structure, a drawofi' delivering from said tank to said sedimentation structure, and means for imparting to the liquid in said tank a circuitous path between the inlet and said draw-off for effecting a suitable period of retention.

37. Liquid treating apparatus comprising a plurality of mixing tanks, means for de livering the liquid to be treated into one of said tanks, a draw-off delivering from said one of said tanks to another of said tanks. a draw-ofi' delivering from said other of said tanks, means for introducing materials into the liquid to be treated in advance of and subsequent to said first named drained, and means for imparting to the liquid in each of said tanks a circuitous ath between the inlet and draw-off for efi'ectmg in each of said tanks a suitable period of retention.

" 38. Liquid treating apparatus com rising a plurailt of mixing tanks, means or delivering t e liquid to be treated into one of said tanks, a draw-oil delivering from said one of said tanks to another of said tanks. a sedimentation structure, a draw-0E delivering from said other of said tanks to said sedimentation structure, means for introducin materials into the liquid to be treated in advance of and subsequent to said first named draw-01f, and means for imparting to the liquid in each of said tanks a circuitous path between the inlet and draw-oil. for effecting in each of said tanks 0. suitable period of retention.

-89. Mixing structure comprising a tank,

liquid inlet and draw-0B disposed remotely from each other, means for imparting to the liquid in passa e from the inlet to said draw-off a whir ing movement, and means for effecting an increased velocity of the liquid adjacent its entry to said draw-0E.

40. Mixing structure comprising a tank,

means for delivering liquid into said tank tangentially to impart a whirl thereto, a draw-ofi' disposed remotely from said inlet, whereby the travel of the liquid through its circuitous ath to the draw-01f effects a suitable period of retention.

41. Mixing structure comprising a tank, means for delivering liquid into said tank tengentially to impart a whirl thereto, and a draw-oil disposed remotely from said inlet, whereby the travel of the liquid through its circuitous path to the draw-ofi' effects a suitable period of retention, said tank converging toward said draw-ofl for effecting increase of velocity of the liquid as it approaches said draw-off.

42. Dissolving apparatus comprising a tank, means for deliverin liquid and ma terial to be dissolved therein into said tank, means for effecting delivery upwardly in said tank, a weir b'ox communicating with said tank, and a liquid draw-01f communicating with said weir box.

43. Dissolving a paratus comprising a tank, means for de ivering liquid and material to be dissolved therein into said tank, means for efi'ectin delivery upwardly in said tank, a plura ity of compartments, a weir for each of said compartments over which liquid is delivered from said tank, and independent liquid draw-ofls communicating wlth said compartments.

44. Dissolving apparatus comprising a tank, a down-take conduit within said tank spaced from the bottom thereoflmeans for elivering liquid into said tank adjacent its bottom, and means delivering liquid and material to be dissolved into said down-take conduit. I

45. Dissolvin apparatus comprising a tank, a down-ta e conduit within said tank spaced from the bottom thereof, said tank having a tapering bottom, means delivering liquid through said tapering bottom tangentially, and means for delivering into said down-take conduit liquid and material to be dissolved therein.

46. Dissolving apparatus comprising a tank, a down-take conduit'within said tank spaced from the bottom thereof, said tank having a tapering bottom, means delivering liquid through said tapering bottom tangentially, means for delivering into said downtake conduit liquid and material to be dissolved therein, a compartment adjacent the upper end of said tank, a weir over which liquid flows from said tank into said compartment, and means for drawing ofi' liquid from said compartment.

47. The method of treating liquid, as sewage, water, etc., which-comprises com tinuously adding to a continuously fiowin stream of the liquid to betreated a materia reacting with a content thereof to produce a precipitate, maintaining the liquid and added material in motion for a retention period effecting approximately complete reaction, continuously drawing oif the liquid with the precipitate in suspension therein, and thereafter separating the precipitate and liquid from each other.

48; The method of treating liquid, as

sewage, water, etc., which comprises eontinuousl introducing into continuously flowing iquid to be treated a material reacting with a. content of said liquid to produce a recipitate, maintaining the liquid and ad ed material in motion for a retention period efi'ecting approximately complete reaction, continuously drawing oil the liquid with said recipitate in sus ension therein, and electrically treating said liquid while said precipitate is in suspension therein.

In testimony whereof I have hereunto affixed my signature this 15th day of March, 1923.

FRANK N. MOERK.

" Certificate of Correction.

It is herob certified that. in Letters Patent No. 1,505,104, granted August. 19, 1924, upont e application of Frank N. Moerk, of Philadelphia, Pennsylvania, for an improvement in Electrochemical Processes of Treating Liquids, errors appear in phe printed specification requiring correction as follows: Page-Th2, line 56, after the word whlch strike out the comma; page 4, line 30, for the word of mad orsame page, line 53, for the word is read as; page 6, line 82, after the word su phate insert a-comma and the words in solution in flu water, again in'oducing a precipitate and that the said Letters l atent should be read with this correction therein that the same may conform to the record of the case in the Patent Signed and sealed this 28th day of October, A. D. 1924.

[sun] KARL FENNING,

, Act ing Omwuanbmr of Pattern.

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