US2434113A - Selective adsorption of lubricants - Google Patents

Description

Jan. 6, 1948. H. w. F. LORENZ 2,434,113

SELECTIVE ADSQRPTION OF LUBRICANTS Filed July 18, 1945 @umass AGENT INVENTOR hisATTORNEY Patented Jan. 6, 1948 UNITED STATES PATENT OFFICE] l SELECTIVE ADSORPTION F LUBRICANTS Henry W. F. Lorenz, Jersey City, `N. J.

Application July 18, 1945, Serial No. 605,658 l 15 Claims.

This invention relates to the selective adsorption of lubricants. More particularly the invention relates to the selective adsorption of an oiliness agent out of lubricating oils and the products obtained thereby.

When a good grade of lubricating oil is placed between two steel surfaces which are to b e lubricated a surface active substance hereinafter termed oiliness agent spreads as a film over the surface of the metal and is adsorbed in the pores of the metal as well as coating the surface. Depending upon the amount of' oiliness agent in the oil and nature of the oil, the film will have Vand on the surface of the metal.

different thicknesses with the result that the l thicker the film the lower will .be the surface friction within the bearing. The more polar the oil the better the oiliness film, the more complex the molecular structure, the greater the ionic charge of the molecule and the greater the polarity. Different metals have different abilities to` adsorb or build up a thicker film or greater amount of oiliness agent on the surfaceY and accordingly bearings made up of different types of metal alloys are in use in an effort to provide a good oiliness film and cut down the surface friction.

Lubricants made from of the complex molecular structure hydrocarbon oiliness agent which is quite resistant to decomposition by heat from friction in the bearings. For this reason PennsylvaniaJ grade lubricants have been favored principally upon their ability to maintain the original composition of the oill tion lubrication and this property of maintaining the oiliness film is responsible for their vuse as bearings rather than the friction bearing quality of the metals.

-I have also discovered that when an alloy made up of good oiliness agent adsorbingjmetals has adsorbedy an oiliness agent on the surface,

this oiliness agent may in turn be separated from the alloy by melting the alloy. The melting of the alloy contracts the metal and expels the oill Pennsylvania crudeY which are made up largely of saturated hydro# carbons, contain a comparatively large` amount.

iness agent that has been adsorbed in the pores The oiliness agent thus released may be separated from the molten metal by decantation, ltering or cen'- trifuging.

The complex molecular structure of oiliness agents prevents them from being separated from lubricating foils* by distillation, because they are easily decomposed at high temperatures. By adsorbing the oiliness agents on ,solid alloys which melt at comparatively low temperatures or below the decomposition temperatures of the oiliness agent, the oiliness agent may be separated selectively from the oil in its naturally occurring state.

The primary object of the present invention is to providea method of selectively separating oiliness agent from lubricating oils.

Another object of the invention is Vto provide a method Yof separating oiliness agent from -lubricating oils at temperatures at which the agent will not be decomposed or destroyed.

. A further object of the invention is to provide a method of separating oiliness agent from 1u'- bricants in increments While preservingk its adl vantageousrand film-forming properties.

`With thesevand other objects. in view, the inivention consists in the method of extracting oiliness agents from lubricantsA hereinafter Vdescribed and particularly defined inthe appended claims.

The various features of the invention are i1- lustrated in the. accompanying drawing, which is a diagrammatic flow sheet of an apparatus in which the preferred method of extracting oiliness lagent may be carried out. y i The oiliness agent may be extracted from a 4lubricating oil in a batch process orin a continuous process. In the drawing is lillustrated an apparatus in which the oiliness agent may be extracted continuously. The lubricatingoil is i drawn from a container l0 and flows into a mixer I2 through a line I4. Simultaneously a low melt- 'ing alloy which'rpreferably is in a molten or fculatedto provide suiiicient` temperature in the mixer l2 for meltingthe alloy while in contact 'with the oil. The mixer preferably is provided with a series of stirring blades 24 which are ro- 3 24 is such that when the alloy becomes melted it will be broken up into very fine particles While in contact with the oil. The mixture of nely pulverized metal and oil then flows by gravity through a valved line 26 into a mixing cooler 28.

4 able to remove the oiliness agent in increments by repeated treatments of the oil with the powdered metal.

After the oiliness agent has been adsorbed in the pores and on the surface of the ne grained In the cooler 28 the mixture of oil and molten metal in the cooling mixer 28, this metal is then metal is cooled While being stirred in order to separated from the oil by means of centrifugal break up the metal into a solid, finely granular force. To accomplish this the mixture of metal or pulverizei @materia/l, Contact with the oil. 'and oi'lgpasses through a valved 4line 30 into a By breaking up the-metal into the ne Lparticles centrifuge -32 where the oil passes through a the surface structure is porous and greatly exporous screen and is collected in a receiver 34. panded. This porous surface provides a means .From the receiver the oil is preferably returned by which a large amount of .oiliness y.agent may by .means of .a .pump through a line 3% back to be drawn into the pores and coated over the surthe storage tank 10. If desired, fresh oil may be face of the metal particles. .1.5 .continuouslyfintroduced into the storage tank l0 L Depending upon the type of `alloy metal ,a and oil partially exhausted of its adsorbent agent greater or a smaller amount of oilin'ess 'agent maybe 'drawn'off 'throughaline 38. The powdered may be adsorbed from the oil. Metals which `metal with the oiliness agent adsorbed thereon are desirable for the purpose of making alloys is removed from the centrifugal bowl by means which .are .lowamelting .and which :have a .large `of a .scoop 40 and passed through a line 42 or :adsorption capacity .are cop/per, zinc, lead, tin, other conveying `means to a mixing `'heater 44. antimony? silver .and aluminum. .Alloyscontain- The. mixing heater 44 has substantially the same in gthese metal@ cantb made 11p-Whig@ ywill .have construction as the heater l2, having a heating a melting point below 200 C. and which have .a jacket 46 which maybe heated 'by .Dowtherm .highadsorbing.apacityforoiliness agent. .C OP' 25 ol thellllPDSeDf mltngthealloy. 'Preierabll7 .,pei', cadmium' andfsilver.haveparticularly .high vthe `powdered alloy with foiliness agent therein adsor tiveA ,properties v-wlzlen .they are .alloyed .is stirred yby means Aof arstirrer '43 While being .with otherdoti! melting metals. I .do nct .nf heated Lto assist in eiecting a heat transfer to VCOlllFSe, nrle myself to .alloys of the abovequvCkly melt thev alloy. When the alloy melts .mentipnedmetals Others can be employed, of 30 the physical structure `of the metal shrinks to which the .following is onlya .partialilist; Vexpel 'the oil 'from itssur'face and `pores andthe Percent Percent ree-cent :Per-.Cent glfglttg.

:Bisnmtns f 125 Bismuth 5l). Lead 65.5

Bismum. 91.5

iismuth, .137

BismutlL 149 lintimony.12.50.. Gopperlall 233 'Lead L Cadmium so1deraird'seveal per cent of Antimony or Mercury.

Mercurylamalgamsffwith flead, or tin, or zinc, '.or..-cadmium, :or bismuth, or silver, etc.:

Lead, antmony af-Melting point 239 C- Lithium metal- Melting point 18.6 'CL lium metal?,,afghan-Melting `point '97 C. All@ their alloys, 'eta Some. Oiliness -a'gentS may ybe decomposed .at .temperatures :slightly lower than v200 C. but it .has lbeen round. te .be desirable. t9 choose. those Al111mCi'illls Whll will :Provide an @ill-1195s, agent thatis Lully :stab @ten-member@ 11p 110.290

in. Order- .tQ :p 1de @heiligen-,agent which.

anbe effstrely Vgilded with other .lubricants .ca be @the metal,- -a-Sinsletreatmentwith metal., A single. treatment .uff the 0 11 with "''llness agent in the oilI and therefore it is'preferoiliness ragent in the form of an Voily material is separated from the molten metal. This mixture of molten metal `amil oil then passes through a Valved .line 50 4into a centrifugal extractor 52. The oiliness agent vpasses through the `porous centrifugal Vbowl `and flows through a line 54 intor a receiver 56., The vmolten alloy is removed by means `of a scoop 58 and preferably is returned direct-ly -to the heater :l2 through `a :line 611./ .In .accordance with the iamount ofimolten Ynl .etal returned `through the linev -6'0 the famount .of meta-l introduced from the container J6 `will beA accurately Acontrolled.

The Dowtherm for; heating the metal inthe heaters, |22' and 4G fis Vpreferably :circulated :through .a tubularl heater 62 by means -zofsa hot however, that if a batch of oil is treated by continuously subjecting the oil to different bodies of powdered or finely granulated alloy much more oiliness agent is recovered in the first treatment than in the succeeding treatments. It is found desirable, therefore, that the oil should be recirculated into contact with the powdered alloy atleast five to six times to recover the maximum amount of an oiliness agent.

Depending upon the type of metal usedv as an adsorbing agent and the type of lubricant, it has been found that the ratio of alloy to oil may vary from one to twoparts by Weight of alloy to five to ten parts by weight of oil.

It has also been found that when eicient stirring apparatus is employed the alloy may be effectively melted and broken up into finely divided particles when the temperature of the alloy is not more than five to ten degrees above its melting point.

The oiliness agent which has been extracted from lubricating oil may be used Vas an additive or blending agent with other lubricants to build up an effective lm to reinforce lubricants being used. The oiliness agent may be added to lub-ricants that have been partially exhausted by use or it may be added to new lubricants in order to build up their oiliness properties.' It has been found that the addition of 0.5 to 2.0% by weight of the oiliness agent will provide a good and effective lubricant for most purposes. Furthermore oiliness agent may be extracted from lubricants that have the ability to stand a high temperature of friction heat without decomposition and such oiliness agent added to lubricants that ordinarily will not stand such temperatures will improve the lubricants in this respect. This oiliness agent may be used, therefore, in blending with oils which have poor oiliness characteristics but excellent viscosity characteristics, and thus build up new and effective lubricants.

Although the oiliness agent has been described as being extracted from oily paraflinic lubricants and particularly high molecular weight hydrocarbons, the invention is not limited to this purpose but may be utilized for extracting the oiliness agent from almost any typ-e of satisfactory lubricating oil.

It is to be understood that the oiliness agent which originally exists in the lubricating oil will, when extracted from the lubricating oil by the process of the present invention contain some of the lubricating oil. It is preferred to have some of the original lubricating oil associated with the oiliness agent to assist in separating the oiliness agent from the metallic adsorptive medium and to assist in blending the agent with other lubricating oil.

The preferred form of the invention having been thus described, what is claimed as new is:

1. A method of extracting oiliness agent from a lubricating oil containing an oiliness agent comprising: thoroughly wetting a solid metal having a melting point below 200 C. with a lubricating oil to impregnate and coat the surface of the metal with oil, separating unattached oil from the metal, melting the metal to set free the attached oiliness agent and recovering the oiliness agent by gravity separation.

2. The method defined in claim 1 in which the metal is a low melting alloy.

3. The method defined in claim 1 in which the lubricating oil is a high boiling, high molecular weight paraifine oil.

' 4. The method defined in claim 1 wherein the lubricant is subjected to repeat-ed treatments of the metal to extract oiliness agent in increments.

5 The method defined in claim 1 in which the metal is reduced to a finely granular solid form to condition it for contact with the oil to attach the oiliness agent thereto.

6. The method defined in claim 1 in which the metal is mixed with oil, the mixture heated to melt the metal, and the heated mixture Vigorously agitated to break up the metal into nely dispersed form while in contact with the oil, the metal then being solidified in contact with the oil while being agitated to increase the amount of oiliness agent attached to the metal.

7. The method defined in claim 1 in which the molten metal is separated from the oiliness agent and mixed while in a molten state with more oil, then agitated and cooled to reduce the metal to a solid, nely granular state for attaching oiliness agent thereto.

8. The method defined in claim 1 which is carried out as a continuous cyclic method in which oil is repeatedly re-treated by the metal.

9. The method dened in claim 1 in which a low melting alloy is mixed with the oil, the mixture heated to melt the alloy and the heated mixture vigorously agitated to break up the alloy into a finely dispersed form while in contact with the oil and solidifying the alloy in iine granular form incontact with the oil to increase the amount of oiliness agent attached to the alloy.

10. The method defined in claim 1 which is carried out as a continuous cyclic method in which the metal and oil are repeatedly .re-treated until 1,5 to 2.0% by weight of the oil has been removed as oiliness agent.

11. The method defined in claim 1 in which the weight of metal to the weight of oil is in the ratio of one part by Weight of metal to two to ten parts by weight of oil.

12. The method defined in claim 1 in which the gravity separation is a centrifugal force separation.

13. A method of extracting an oiliness agent from a hydrocarbon oil containing the same comprising: thoroughly wetting a finely divided solid metal substance having a melting point below the temperature of the beginning of decomposition of said hydrocarbon oil to impregnate and coat the surface of said finely divided solid metal with oiliness agent in the oil; separating the unattached oil from the solid metal particles; melting and agglomerating the metal particles to a liquid metal mass; recovering oiliness agent from said agglomerated solid metal mass by gravity separation; and cooling the metal to solidify the same ready for further use in the method.

14. A method of extracting oiliness agent from a hydrocarbon oil containing the same as set forth in claim 13 comprising: placing metal having a melting point below the temperature of the beginning of decomposition of said hydrocarbon oil and the hydrocarbon oil to be treated in an enclosed container and heating to a temperature suiicient to melt the metal; vigorously agitating the metal and oil during heating to break up the molten metal into finely divided liquid-particles in contact with the oil to increase the surface of metal exposed to the oil; cooling the oil and lquidimtal While simultaneously stirring to solidify the metal and toY adsorb tlneV oiliness agent on thel surface of the metal particles; arresting the stirring; separating unattachedoil from the solid metal particles; melting the metal particles to` agglomerate` them into a single mass to set free adsorbed oiliness agent; and recovering the oilirress agent separated from the metal by gravity' separation.

15". A complex highmolecular weight hydrocarbon oiliness agent extracted from a high molecular Weight hydrocarbon lubricating oil by adsorption on a low melting, porous'metal surface While cold and released from'the metal surface by melting the metal, said agent being capable of producing a thicker oil film on a surface to be lubricated than the lubricating oi'l from which it is extractedwill form, and said oiliness agent 8 havinga greater ionic chargeA on its molecule than the ionic charge of the molecule orV the lubricating oil' from which the agent is extracted.

' HENRY W. F. LORENZ.

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