US2216680A - Process for treating refined oil - Google Patents

Description

Oct.v 1, 1940. B. H. THURMAN PROCESS FOR TREATING REFINEDOIL 2' sheets-sneer; 1

Filed March 5, 1938 @www Oct. l, 1940. B- H. THURM'AN 2,216,680

PRSCESS FOR TREATING REFIHED OIL v Filed lamb 5, 1958 2` Sheets-Sheet 2 ""llll/LI r11/lll l .Iz/af Patented Oct. i, 1940 t UNITED .STATI-:s

PATENT ori-ics 2,216,680 PROCESS FOR TREATING BEFINED OIL Nevada Application March 5,

9 Claims.

This invention relates to aprocess of treating refined animal and vegetableoils, and more particularly to a process of removing residual impurities from such oil after it has been treated with alkali and the resultant soap stock separated from the oil. y

In processes of refining animal and vegetable oils by an alkali treatment, the oil, after theresultant soap stock has been separated therefrom either by a settling or centrifugal separation step, contains small amounts lof residual alkali, soap and water. This rened oil has been treated by adding water, agitating to mix the 'water with the oil and then separating the water either by a gravity settling and decantation step or by centrifugal separation. Any water remaining in the oil was then conventionally removed by vacuum drying to vaporize the water from the oil.

The agitation of the water with the oil during the washing step, particularly in the presence of air, formed an emulsion which caused difculty in separating the water from the oil, especially where it was attempted to perform the separation centrifugally. Thus substantial retained in the oil after such gravity or centrifugal separation, which required vacuum drying eq'uipment' of large capacity and also resulted in leaving deleterious quantities of alkaliand soap in the dried oil. f

. In accordance with the present invention, the oil is washed in a closed system by introducing a stream ofv water into a stream of the oil tobe washed. Mixing is accomplished out 'of contact withjthe atmosphere and without mechanical' agitation. This washingoperation does not form the dilcultly separable emulsion above referred to, Vand substantially all of the water containing dissolved impurities can be removed from the oil by continuous centrifugal separation; The amount of water left. in the separated oil isv extremely small, and can be easily removed from the oilbyvacuumdrying equipment of- -relatively small capacity without leaving deleterious amounts of soap and alkali in the oil. p Y

Also, in thexcase of animal and vegetable o il which has been l,centrifugally separated from soapfstockafter alkali treatment of the oil, agitation of the mixture of oil and soap stock in the entrance of 'the centrifugal in the pesenceof air, and also the agitation duefto discharge'v of the'separa'ted oil as the lighter eiliuent from the centrifugal bowl in the presence of air,` frequently'causes considerable air to bey retained ,in theoil. The retainedvair` appears to be presamounts of water with dissolved impurities were- Benjamin H. Thurman, Bronxville, N. Y., assignor to Refining, Inc., Reno, Nev., a corporation of 1938, Serial No. 194,226

(Cl. 26o- 428) ent in a complex emulsion of oil, soap, water and air. This `emulsion will collect on'the surfaceof a quiescent body of oil that has been discharged from the refining centrifugal in the form of a jelly and appears to be primarily of the water-in-oil type, such that it is not dissolved by water. This complex emulsion is not, ,therefore, effectively washed from the oil by washing with waterl followed by centrifugal separation, but substantial amounts of soap and lo alkali are retained in the washed and separated oil.

In accordance with the present invention, it has been found possible to break-the complex emulsion referred to and render the soap and 15 alkali contained thereinreadily removable from the oil by a washing and separation operation. By introducing the oil discharged from the reiining centrifugal into a de-aerating chamber and retaining it in saidchamber fora substango tial length of time, the air can be removed from the complex emulsion above referred to. This can be accomplished by slowly agitatin'g the oil in open tanks so that the air is liberated into the atmosphere, taking care that the agitation is 25 not suilicient to beat air back into the oil, but it is'preferred to maintain the oil discharged from the refining centrifugal out of lcontact with the atmosphere, as it is' ordinarily at a temper-- ature between 100 F. and 160 at the time 30 of discharge. Particularly at the higher temperatures in this range, the oil tends to darken in contact with the atmosphere. It is preferred, therefore, to de-aerate the oil in a closed chamber under vacuum conditions. The vacuum 35 rapidly removes the air contained in the complexemulsion above referred to vand renders the impurities therein soluble in water so that it can be easily removed by a washing and centrifugal separation step. It'is, therefore, an object of the present infvention to washpreviously alkali rened oil by mixing a streamaof the same with a stream of water, out of contact with the air vand without'fmechanical agitation, and then continuously 45 separating the water containing dissolved imfpurities from the oil.

Another Vobject lof the invention, is to provide a process ofwa'shing refined animal and vege-` ltable oils in which the oil is mixed with water 50 without forming'a` diilcultly separable emulsion,

and 'the water containing dissolved impurities continuously separated from theoil. Another object of the invention is`to provide a lprocess gf. continuously washingreiined animal and vegetable oils so as to leave only small amounts of water containing dissolved impurities in the oil, thereby reducing the amount of drying of the oil subsequently necessary;

Another object of the invention is to provide a process of removing residual impurities from refined animal and vegetable oils inwhich the oil is subjected to a de-aerating treatment prior to washing and drying. .f

Still another object of the invention is to provide a -process of removing residual impurities from animal and vegetable oils centrifugally separated from soap stock in the refining process, in which air is removed from the separated oil prior to washing the same. I

A further'object of the invention is to provide an improved apparatus for washing refined oils, in which mechanical agitation is avoided.

A still further object of the invention is to provide an apparatus for de-aerating rened animal and vegetable oils, and then washing and drying the same. Other objects and advantages of the invention will appear in the following description of the process and the apparatus shown in the attached drawings, of which:

Figure l is a diagrammatic drawing of acomplete system for de-aerating, Washing'and drying; and

Figure 2 is a similar view of a modified deaerating apparatus.

Referring to the drawings, and more particularly to Figure l: I0 indicates a reiining centrifugal for separating soap stock from rei'lned oil following an alkali treatment thereof; II indicates in general a novel de-aeratlng system for removing the contained air from the separated oil; I2 indicates, in general,y a proportioning and iiow mixing device for mixing a stream of water with a stream of oil; I3 indicates a centrifugal separator for continuously separating the water containing dissolved impurities from the oil; I4 indicates a. vacuuml drying chamber for the oil separated from the water; and I5 indicates in t general a vacuum and condensing system forv maintaining a vacuum in the vacuum drying chamber I4 and the de-aerating apparatus I I.

A mixture of oil and soap stock from a refining operation, which may be a continuous relining operation, Vsuch as disclosed, for example, in the patents to Clayton et al. Nos. 1,100,274; 2,100,- 275, is introduced into the refining centrifugal I8 through a pipe I6. The soap stock is therein separated from refined oil and discharged as a heavy eiiiuent from the discharge member I1 into the receptacle I8. The refined oil is discharged as the lighter eiljiuent through a pipe I9, and is preferably delivered into a float tank 20 or similar device for preventing loss of vacuum in the de-aerating system hereinafter described. The float tank 20 may be provided with a vent 2l and contain a float 22 pivoted at 23 for closing a valve indicated diagrammatically at 24 when the oil in the iioat tank 28 reaches a predetermined lower level. When the level of the oil in the tank 20 is above this predetermined minilevelain thechambers i128 andan, as hereinafter described. The valve 32 is shown in its normally open position, when fluid pressure is not applied to the diaphragm chamber 34, while the valve 33 is shown in its closed position due to fluid pressure applied to its'diaphragm chamber 35.

The de-aerating chambers 28 and 23 may be identical in construction, and only one will be described in detail. Thus the chamber 28 is a closed chamber and is preferably provided with an agitator 36 having a shaft 31 extending through a packing gland 38 and rotated from any suitable source of power through a pulley 33. The chamber 28 is also preferably provided with a heating coil 48 through which any desired heating medium, such as steam or hot water, may be pass'ed to maintain a desired temperature in the chamber 28. The chamber 23 is also preferably provided with an external float chamber 4I positioned adjacent the lower portion thereof and connected thereto by a pipe 42 provided with a check valve 43 for preventing oil from owing into the float chamber from the lower portion of the de-aerating chamber, but permitting oil to ilow from the float chamber 4I into the deaerating chamber. 'I'he fioat` chamber 4I is also connected to'the upper portion of the de-aerating chamber through a pipe 44 and a plurality of pipes 45 connected to the de-aerating chamberat a plurality of levels and provided with manually operable valves 45. 'I'he level of oil reached in the de-aerating chamber 28 before oil ilows' into the oat chamber 4I can be determined by the vaves 46, as oil will notilow into the float chamber 4I until the oil level has reached the height of the lowest open valve 45 because of the check valve 43. A vent pipe 41 also connects the top of the de-aerating chamber 28 with the float chamber 4I to prevent trapping of air therein. 'I'he float chamber 4I contains a float 48, pivoted at 49 and arranged to operate a fluid control valve through a lever 5I slidably connected to a valve plunger 52 by a pin 53 and slot 54 in the plunger 52. The iioat 48 and valve 50 are utilized lto control the admission and withdrawal of oil from the de-aerating chambers 28. as will bev hereinafter described.

The de-aerating chamber 23 is likewise provided with a similar float chamber 4I connected to the chamber by a pipe 42' having a check valve 43' therein; a pipe 44 and a plurality of pipes 45' at different levels, each provided with a manually operable valve 46'; and by a vent pipe 41'. The float chamber contains a float 48' pivoted at 49 and operating a fluid control valve 50' through a lever 5I! slidably connected to a valve plunger 52 by a pin 53 and slot 54'. Interlocking means is provided between the fluid control valves 50 and 50'. This means may include a bell crank lever 55 pivoted at 55 and having one arm engaging a shoulder on the valve plunger 52 and the other arm plvotally connected to a link 51 also plvotally connected to one arm of abell crank lever 55' pivoted at 58' and having the other arm engaging a shoulder on the valve plunger 52. l

Oil is withdrawn alternately from the de-aerating chambers 28 and 28 through pipes 58 and 58 respectively. The pipe 58 is provided with a fluid pressure operated valve 58, having a diaphragm chamber 58 and a check valve 8i for preventing return flow of oil into the chamber 28. The valve 58 is shown' in its normally closed' position when no iiuid pressure is applied to diaphragm chamber 60. In similar manner.

the pipe 58 ;isY provided with .a fluid pressure 15 by opening a desired valve 45. During th'e filling operated valve 59 having a diaphragm chamber 66 and a check valve 6I for preventing return ilow of oil into the de-aerating chamber 29. The valve 59 is shown in its open position due to fluidpressure applied to the diaphragm chamber 66. The pipes 56 and 56' are connected at their ends remote from the de-aerating chambers to a common oil'withdrawal pipe 62 leading to a heating device 63 through which oil is drawn alternately from the de-aerating chambers 26 and 29 by the` proportioning pump 64 driven by a variable speed motor 65. The oats 46 and 46' may also be employed to open electrical contacts 66 and 66', respectively, which contacts may be connectedJ in parallel in the power supply cir cuit (notl shown) of the motor 65 so as to stop this motor when the floats are both in their lowermost position.

'I'he plunger 52 ofthe iluid control valve 56 may have a port 61 therethrough which, in the uppermost position of the plunger 52 registers with a pipe 66 connected to a source of uid pressure, for example, city water mains. In the lowermost position of the plunger 52, the port 61 registers with an exhaust pipe 69. The port 61 registers in both positions with a pipe 16 leading to the diaphragm chambers 34 and 66 such that the valves 32 and 59 are in their normal position as shown when the plunger 52 is in its lowermost position. When the plunger 52 is in its uppermost position, the pipe 16 is connected to the source of uid pressure, so that `iluid pressure is applied to the diaphragm chambers 34 and 66 to close valve 32 and open valve 'I'he plunger 52' of the/valve 50' is likewise provided with a port 61 which will connect the pipe 16 with a source of uid pressure through pipe 66 or release the pressure applied through the-pipe 16' by connecting 'it to an exhaust pipe 69'. The plunger 52 thereby applies uid pressure through! the pipe 16' to the diaphragm chambers 35 and 6I' to close valve 33 and open valve 59' when the plunger 52 is in its uppermost position and allows the valve 63 to be in its` normally open position and the valve 59' to be in its normally closed position when the plunger 52' is in its lowermost position.'

As stated before, av vacuum is preferably mailitained in the chambers 26 and 29, and these chambers may be connected by pipes 1I, 1l and 12 to a condenser 16 connected to a vacuum pump 14. The condenser 13 may be of the conventional jet type, into which water is introduced through the pipe 15 and from which wabers 28 and 29 may be empty, such that ,the floats 46 and 46' are in their lowermost position and the motor 65 is not driving the pump 64. The plunger 52 and 52' may be in the position shown or may be shifted thereto manually and all of the manually operable valves inA the pipes 26, 21, 56 and 56' may be' open. Oil will flow through the pipes -25 and 26 into'the chamber 26, asl there is a vacuum maintained therein bythevacuum and ycondensing system I5 above de' scribed." As valve 59 Ais closed, the oil willrise in the chamber 26 until the level of an open -va've 46 is reached.Vv The level reachedv in chamber`26' and, therefore, the time the oil is allowed to rein the chamber 26 can thus be controlled of chamber 26, oil does not ilow into the float chamber 4I, because of the check valve 43, until' it reaches the levelof an open valve 46, at which time oil flows into the iloat chamber 4I through the open valve 46. Oil owing into chamber 4| raises the float 46 to raise the plunger 52 connected thereto to apply fluid pressure' to the diaphragm chambers 34 and 60 of the valves 32 and 59, thus closing valve 32 to stop the flow of oil into the chamber 26 and opening valve 59 to permit oil to discharge through pipe 56 from chamber 26. Raising of the plunger 52 depresses plunger 52' of fluid control valve 5l', through the interlocking mechanism including bell cranks 55 and 55 andV link 51, to apply fluid pressure tor diaphragm chambers 65 and 6'6' so as to open valve 33 and close valve 59. Raising of thefloat 48 also starts the motor 65 by allowing con- .tacts 66 and 66 to close. The system will then continue to work automatically, oil will be withdrawn from chamber 26 while chamber 29 is being lled. When, the level in chamber 26 ap"- v proaches the bottom of the chamber, oil will flow from the iloat chamber 4I associated therewith into the chamber 26, thus allowing iloat 41 to fall. Itthis occurs before a level is reached in chamber 29 which causes oil to ilow into the float chamber 4I', the contacts 66 and'66 will be opened to stop motor 65 and withdrawal of oil until iioat 46 is raised. When oil ows into float chamber 4I', plunger 52' of fluid control valve 50v is raised and at the same time plunger 52 of iiuid control valve 56 is depressed by the interlpcking, mechanism. This causes valves .32'

and 5.9 to be opened and valves 23 and 59 to be closed and at the same time starts motor 65 so that oil is'withdrawn from chamber 29 as chamber 26 is lled. If it should happen that chamber 26 becomes iilled up to a level at which oilenters oat chamber 4I before chamber 29 is emptied, the iioats can be balanced so that they will not move until oil flows out of float chamber 4l' due to the emptying of chamber 29.

Thus one de-aerating chamber will always be emptied before oil is withdrawn from the other.

The above described operation will repeat in-A continuous withdrawal is effected, without interruption by stoppage of motor 65.

Agitation oi the oil in de-aeratingchambers 26 and 29 under vacuum conditions is eiective to `remove the air from the oil, thus effectively breaking the complex emulsion above described. Asl before stated, a similar result can also be accomplished by agitating the oil or'evenmerely allowing it to stand in an open tank. However; vacuum de-areating is preferred, Aand if desired,

a controlled lamount of moisture can also bex withdrawn'from the oil in the chambers 26 and 29, depending upon the time of treatment therein, the temperature of the oil and the-degree of vacu said complexemulsion.

Thus, a stream of de-aerated, and if desired at least partially dried, oil can bey continuously pumped from the d e-aerating system` through the pipe' 62 by'means of the'pump'64: Inorder to wash this oil, the `same is delivered to the mixI ,ing device 16 and a stream of wateralso delivered in order torfurther assist Ain breaking to the mixing device through the pipe 18 by means of a proportioning pump 80. The pump 80 may also be driven from the motor 85 through a variable speed device 8| and provision may be 5 made for bringing either or both of the oil and water to a desired mixing temperature by heating devices 63 and 82 respectively. These heating devices may include heating coils 83 through which any desired heating fluid, such as hot water, may be circulated. 'I'he preferable temperature of mixing will vary with different oils but will usually be between 100 and 160 F.

Satisfactory mixing has been accomplished by merely injecting the stream of water at right angles into the flowing stream of oil, but a somewhat better mixture can be obtained by the mixing device 18 diagrammatically disclosed. This device may include a tubular member 85 surrounding the extremity of the pipe 1| to form an annular conduit 8B through which an annular stream of oil flows. A hollow member 81 having a concave upper surface 88 and positioned in an enlarged tubular member 488 is arranged such that the water entering through the pipe 1| strikes the concave surface 88 and is projected outwardly as an annular film into the annular stream of oil flowing in the annular conduit 86. Eilicient mixing is thereby obtained,and the mixture may iiow downwardly through the annular conduit 80 formed between the member 81 and tubular member 88 and then be forcedinwardly through an annular orice 8| between the members 81 and 88 to further mix the same. 'Ihe resulting mixture then flows upwardly through the hollow member 81 and is discharged through a pipe 92. The detailed construction of this mixing device is disclosed in the copending application of Benjamin H. Thurman, Serial No. 190,673 filed February l5,` 1938, now Patent No. 2,142,062, dated December 27, 1938.

Additional heatmaybe imparted to the oil and water mixture in a heating device 83 which may be similar to the* heating devices 63 and 82 and include a` heating coil 83 positioned in a chamber 45 84. The mixture of oil and water is then delivered to the washing centrifugal |3 in which the wat'er containing dissolved impurities is separated from the oil and discharged as a heavy effluent through the conduit 84 into receptacle 85. The de-watered 50 4oil is discharged through a pipe 86 into a float tank 81, which may be entirely similar to the float tank 20, for preventing loss of vacuum in a vacuum drying chamber I4 into which the oil is delivered from the float chamber 81.

peratures for mixing water vwith the oil and for the separation of the water from oil for each oil being treated. In many operations, the tempei ature of the oil withdrawn from the chambers 00' 28 and 28 is sufllciently high that no additional h t need be added thereto before or after mixng with water such that the heating devices 63, 82 and 83 are unnecessary. However, in certain cases it may be desirable to increase the tempera- 05 ture of the oil or water or both before mixing,

' or the temperature of the mixture prior to centrifugal separation. 'I'he heating devices 63, 82 or 83 may be employed for this purpose. Ordinarily, the temperature of separation of the l0 water from the oil should be between 100 F. and 160 F., but no precise temperature applicable to every oil can be given, as the best temperature for separation will vary with the various oils.

The vacuum drying chamber Il comprises a 18 closed casing 88 connected to the vacuum system It has been found that there are Aoptimum tem- I5 by a pipe 88. The oil is drawn into the chamber I4 by the vacuum present therein, and may be distributed by a distributing member |00 so as to drop as a lm into the body of oil in the lower portion of the drying chamber i4. In order to maintain the desired temperature in the vacuum drying chamber |4, it may be providedwith a heating coil |0| through which any desired heating medium, such as steam or hot Water, can be circulated. The dried oil may be withdrawn from the vacuum chamber I4 by means of a pump |02 and sent to storage, or to conventional bleaching and deodorizing equipment.

lIn Figure 2 is shown a suitable apparatus for carrying out a modification of the de-aerating step. In this modiiication oil is delivered from the float tank 20, which corresponds to the similar tank 20 of Figure l, into a de-aerating chamber |03 by a pipe IDI. The de-aerating chamber may be similar in construction to the deaerating chambers 28 and 28 of Figure 1, but is arranged for the continuous flow of oil therethrough. This chamber may comprise a closed casing |04 connected to a-vacuum system, such as that shown in Figure 1, by the pipe 12, and may be provided with an agitator 36 and vheating coil 40. Oil is continuously withdrawn through the pipe |05 by a pump such as the pump 64 of Figure 1 and the oil subsequently washed and dried as discussed with reference to Figure 1. By maintaining the chamber |03 relatively full of oil and agitating the sameunder vacuum con ditions, substantially all of the air in the oil and any desired amount of water can be withdrawn from the oil so as to break the previously discussed complex emulsion. The time the oil is treated in the 'de-aerating chamber |03 of Fig` u're 2 or the chambers 28 and 28 will depend upon the type of oil being treated and the amount of air and complex emulsion present therein. Ordinarily this time will range between thirty minutes and one hour, but in some cases this time may be as low as ten minutes.

Thus, the process and apparatus of the present invention enable oil to be washed by admixing water therewith, out oi.' contact with the atmosphere and without mechanical agitation, such that the water containing dissolved impurities can be substantially completely centrifugally separated from the oil. Also, the oil discharged from the refining operation can be treated to remove air thezefrom, thereby rendering soluble in water, water-insoluble complex emulsions often found in such refined oils so that the washing operationmay be eihciently carried out. The oil is usually discharged from the rening operation at temperatures between 100 and 160l F., and such temperatures are ordinarily maintained in the system. The steam coils 40 provided therein are eective for this purpose. The stability of the complex emulsion above described will determine the length of time necessary to maintain a body of oil in the de-aerating chamber 28 or 28. In most cases, a period of from thirty minutes to one hour will be found suflicient, such that the chambers 28 or 28 should ordinarily be designed to hold atleast the amount of oil which is refined in the refining system during an hour's operation. By opening a selected valve 46 associated with each de-aerating chamber o1' Flgureg., the period during which oil is allowed to remain' in a de-aerating chamber can be madel less than that determined by the full capacity of the chamber..

While the precise de-aerating equipment disiov 'ating apparatus.-

2,216,eeo g closed is preferred, other types may, of course, be employed; for example the automatic valves 32, 33, -59 and 59 of Figure 1 may be directly controlled by the o'ats 48 or 48 or other level-responsive devices, thus eliminating the fluid pressure control. The system of valve'operation disclosed', however,l provides for greater flexibility in the positioning and construction of the de-aer- As before stated, open tanks may frequently be employed, but the employment of vacuum renders the operation more rapid, thus reducing the size of the necessary equipment, and also preventing contact-of the heated oil with the atmosphere.

There are disclosed the preferred embodiments of this invention, but it is to be understood that the details thereof may be varied within the, scopeof the following claims.

I claim as my invention:

1. The process of removing residual impurities from previously rened animal and vegetable oils, which comprises, continuously mixing an advancing stream of Water with an advancing stream of oil in a closed mixing zone, for a brief' period out of contact with the. .air and without substantial mechanical agitation producing a difcultly separable emulsion, advancing the mixture of water and oil continuously to a centrifugal. separator, and centrifugally separating the water containing dissolved impurities. from said oil.

2. The process of removing ties from alkali rened vegetable` and animal oil, which comprises, continuouslyI mixing an advancing stream of -said oil with an, advancing stream of water in a closed mixing zone without mechanical agitation, and separation water containing dissolved impurities from said oil.

3. The process' of removing residual impurities vfrom alkali refined animal and vegetable oil,

whichcomprises,continuouslysubjecting a bodyof said oil to vacuum treatment to remove air therefrom, and thereafter washing said oil with water by mixing a stream of oil with .a stream of water without substantial mechanical agitation producing a. diicultly separable emulsion and separating said water containing dissolved impurities I from said oil.A

residual impuroil, Without substantial mechanical agitation producing a difcultly separable emulsion, and separating said Water from said oil.

5. The process of removing residual impurities i from alkali refined vegetable and animal oils, which comprises, forming a body of said oil in a closed chamber, subjecting the upper surface of said body to subatmospheric pressure for a period of time between approximately thirty minutes and one hour, thereafter mixing said oil without substantial mechanical agitation producing a diilicultlyI separable emulsion, 'and separating said Water. from said oil.

6. The process of removing residual impurities from animal and vegetable oils discharged from a. refining operation, which comprises, continuously mixing an advancing stream of water'- with an advancing stream of oil in a closed. mixing zone out of contact with the air and Without mechanical agitation producing a diiicultly' separable emulsion, and centrifugally separating the water containing dissolved impurities from said on at a temperature-suiciently elevated to facilitate centrifugal separation.

7. The process of removing residual impurities from alkali refined vegetable and animal 011,.

which comprises, continuously mixing an advancing stream of said oil with an advancing stream of water in a closed mixing zone without mechanical agitation, and thereafter centrifugally separating water containing dissolved impurities from said oil.

8. The process of removing residual impurities from alkali refined vegetable and animal oil, which comprises, continuously mixing an advancing stream of said oil with an advancing stream of water in a closed mixing zone at a temperature between 100 and 160 F. and without mechanical agitation, and centrifugally separating said water containing dissolved impurities from said oil.

9. The process of removing residual impurities from alkali refined animal and vegetable oil, which comprises, subjecting a body of said oil to vacuum treatment to remove air therefrom, thereafter mixing said oil with water in a closed system out of contact with the air and without mechanical agitation, and centrifugally separatwater with ing said water containing dissolved impuritiesA "cnIFIcATE 'or comemos. "l A Pat-ent No.` 2 {21j6} 680. Y October 1 1914.0.

' 'Bmgwu'n n. manu.;

It 1 5 hereby certified that error appears 1h the printed A Spee-rimmed of the abovenumbered patent requiring correction ae follows: I age' 2, firstv eolmnn, line 51, for the paterprnumber "1,100,27h" read -2,1oo,27h; page 5, first co1mnn,'11ne 5'?, elsing 2, for "separat1on-V read 'searat1ng; and that the said Letters Patent should be read with this'correotion therein that the same may coniom to the record -of the-case inthe Patent Office.

Signed and sealed th1e5thv day 'of November, A.: -D..191|.0`.

Henry van' Arsdalef (Seal) ActingComunis stonerv of Patents.

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