US2373733A - Steam cylinder lubricants - Google Patents

Description

Patented Apr. 17, 1945 STEAM CYLINDER LUBRICANTS Elmer Wade Adams, Hammond, and Frederick H. MacLaren,

Munster, Ind.,

asslgnors to Standard Oil Company, Chicago, 11]., a corporation of Indiana No Drawing. Application May 27, 1944, Serial No. 537,736

9 Claims. (Cl. 2522-53) This invention relates to lubricants for valves or other mechanical parts exposed to steam and more particularly to steam cylinder lubricants and the like.

The principal problem of lubricationof steam enginesis that of lubricating the internal parts where the greatest frictional losses and wear ocour. The problem which is peculiar to the steam engine lubrication and introduces factors seldom encountered elsewhere is due to the fact that lubrication must be accomplished on frictional surfaces in direct contact with or swept by steam. In direct contact with the steam are the working surfaces of the cylinder, the piston and piston ring, the valves for admitting and exhausting steam, and the connecting rod and valve rods. Steam varying in the properties it acquires when produced and in the properties it assumes during use sweeps in and out of the cylinder on each stroke of the piston and adds to the difficulty of securing good lubrication. These factors require that the steam cylinder be preferentially wetted with oil. rather than with the water re sulting from steam condensation and for this reason lubricants employed in steam cylinders must be capable of rapidly forming an invert emulsion with the steam. While the steam cylinder lubricant must be one which readily atomizes and mixes with the steam and leaves a tenacious film which resists subsequent displacement by water, the oil carried over with the steam must be a relatively viscous mineral oil, preferably a heavy steam refined lubricating oil and small amounts of a fatty material such as lard oil and a complex glycerlde phosphoric acid ester, for example lecithin. The phosphatidic material in the steam cylinder lubricant disclosed in our copen'din -application is a highly desirable constituent since it is a very effective invert emulsifier. It has been discovered, however, that under certain conditions steam cylinder oils in which the phosphatldic material is the sole agent for producing an invert emulsion performed unsatisfactorily due to the high detergency effect of the lecithin. This results in dry pistons and cylinder walls and reduces the effectiveness of the compounded oil as a lubricant. Furthermore, it has been found that under certain conditions this lubricant did not separate satisfactorily from the exhaust ste am.

It is therefore an object of the present invention to provide a steam cylinder lubricant which will readily form a stable invert emulsion and which at the same time does not possess too great detergency properties.

Another object of the present invention is to provide a steam cylinder lubricant which will readily form a stable invert emulsion and which will maintain a continuous resistant lubricating oil film on or between the metal surfaces to be lubricated.

Another object of the present invention is to provide a steam cylinder lubricant which will quickly atomize and mix with steam.

Still another object of the invention is to provide a steam cylinder lubricant which will separate satisfactorily from exhaust steam.

A still further object of the invention is toprovide a steam cylinder oil which is resistant to oxidation and to the formation of objectionable deposits.

Other objects and'advantages of the invention will become apparent from the following description thereof.

We have discovered that a steam cylinder oil capable of rapidly forming invert emulsions when mixed with steam, which is stable and which maintains a continuous resistant lubricating film is obtained by compounding a relatively viscous mineral oil with small amounts of a fatty material, preferably a fatty oil, a complex glyceride phosphoric acid ester and a residuum having a Furol viscosity at 210 F. of from about 150 secondsto about 950 seconds obtained from "a naphthenic crude petroleum oil or from a crude petroleum which is predominantly naphthenic.

The mineral oil constituent is preferably a viscousoil having a Saybolt Universal viscosity at 210- F. of from about seconds to about 300 seconds and preferably from about seconds to about 250 seconds. For example, the oil may I be a heavy steam refined Mid-continent lubricat- The fatty material or fatty oil such as taliow,

lard oil, animal fat, beta fat and the like can be employed in quantities ranging from about to about and preferably from about 7% to about 9% The complex glyceride phosphoric acid ester can be a phosphatide such as lecithin. cephalin and the like. While substantially chemically pure phosphatidic materials can be employed, commercial grades of phosphatides or commercial lecithin products known by the trade names of Lipoidol, Soyab, Colloidal HX and others are suitable. The phosphatidic material can be employed in amounts of from about 0.05% to about 1% and preferably from about .l% to about .5%.

The other constituent of the herein described steam cylinder lubricant which functions to form invert emulsions is a residuum petroleum oil having a furol viscosity at 210 F. of from about 750 seconds to about 950 seconds and preferably from about 850 seconds to about 900 seconds obtained from naphthenic petroleum oils or from petroleum oil which are predominantly naphthenic.

Residuums suitable for this purpose are those obtained from Smackover crude oil or crude oil having properties similar thereto. The residuum oil can be employed in quantities within the range of from about 1% to about 5% and preferably from about 2% to about 4%.

The following formulas are specific examples of compounded steam cylinder lubricants made in accordance with the present invention.

I II III Per cent Per cent Per cent Petroleum oil 87. 3 89. 4 1 98. 4 Fatty Gil (lard oil) 8. 5 8. 5 8. 5 Petroleum residuum 4. 0 2.0 2. 0 Ihosphatidc (lecithin) 0.2 0. l 0.1

1 M. c. oil S. U. v. at 210 F.l65 seconds.

1 M. C. steam refined oil-S. U. V. at 210 F.-200 seconds.

3 Pennsylvanias team refined oil-S. ll. V. at 210 F .-220 seconds. 4 Rcsiduum from Smsckover crude oil-mm] viscosity at 210 F.-

' 800-900 seconds.

' pered 50 cc. graduate and the contents thereof,

with the stopper removed, is heated for 45 minutes in a water bath maintained at a temperature of about 165 F. to 175 F.- The graduate is then removed from the water bath. stoppered and inverted three or four times, releasing the pressure each time. The graduate is then shaken vigorously and the time noted and recorded in seconds for a rigid emulsion to form. Oil compositions which fail to form a rigid emulsion with 91.5% M. C. steam refined oil (S U V at 210 F 8.5% lard oil.

asrarss 3 minutes of vigorous shaking are unsuitable as steam cylinder lubricants. The effect of naphthenic petroleum residuums in reducing the time for a rigid emulsion to form in'the above test is demonstrated by the following data:

Time (seconds) for rigid emulsion to form Oil composition 91.5% Pa. steam refined oil (8. U. V. at 210 F.220

seconds H 300 8.5% lard oil refined oil (8 8.5% lard oil. 0.57 lecithin 89.4 0 Pa. steam refined oil (S. U. V. at 210 45 2.0% Smackover residuum Ziurol iscositynt 2l0 F. 800-900 seconds) .516.

8.5% lard oil seconds) 8.5% lard oil. 0.5% lecithin 89.4% M. C. steam refined oil (S. U. V. at 210 F.200

seconds) 0.1% lecithin 2.0% Smackover res no 4.0% Smackover res uum (Iurol iscosity at 210 F.--

800-900 seconds) The above data show that the addition of the naphthenic petroleum residuum materially reduces the time to form rigid emulsions by the MacLaren test.

The effectiveness of steam cylinder lubricants made in accordance with the present invention is further demonstrated by the results obtained in numerous commercial installations.

Steam cylinder lubricants compounded in accordance with the present invention have been subjected to field service test in engines over long periods of time and in most cases under extremely adverse steam conditions. Closely observed tests were conducted on twenty-six engines including unifiow a well as Corliss, slide and piston valve types. These engines ranged in size from. 7"xl2" running at 300 R. P. M. to 20x40"x42" cross-compound running at about 103 R. P. M. with steam pressure ranging from pounds saturated steam to 230. pounds with 100 superheat. The results of these tests demonstrate that the herein described steam cylinder oils atomized more readily than conventional steam cylinder oils and permitted the use of higher viscosity oils resulting in lower oil feed rates. These tests further demonstrated that our improved steam cylinder oils separated satisfactorily from the ex- -haust steam and in sixteen cases of th twentyj therefore permitted longer operations without the necessity of shut-downs.

Since the steam cylinder oils of the present invention readily atomize with steam, it is possible to use more Viscous oils which accordingly permit lower oil feed rates. By a proper balance of the phosphatidic material and the naphthenic residuum, we have obtained a steam cylinder lubricant which, while readily emulsifying with steam, nevertheless separates from the exhaust steam without difiiculty so that the exhaust steam can 5. A steam cylinder oil as described in claim 4 in which the fatty oil is lard oil, the complex glyceride phosphoric acid ester is lecithin, and the residuum is a residuum obtained from a Smackover type crude oil.

6. A steam cylinder oil comprising a Pennsylvania steam refined mineral oil having a Saybolt Universal viscosity at 210 F. of about 220 seconds, 8 /2% lard oil, 0.1% of a phosphatidic material, and 2% of a residuum petroleum oil having a furol viscosity at 210 F. of about 800 to 900 seconds obtained from a crude petroleum vention except in so far as the same is defined by the following claims.

We claim: I 1. A steam cylinder oil comprising a hydrocarbon lubricating oil having a Saybolt Universal viscosity at 210 F. within the range of about 100 seconds to about 300 seconds,.from about to about 10% of a fatty oil, from about 1% to about 5% of a petroleum residuum having 'a furol viscosity at 210 F. of from about 750 seconds to about 950 seconds, obtained from a naphthenic type crude petroleum oil, and from about 0.05% to about 1% of a complex glyceride phosphoric acid ester.

oil of the Smackover type.

7 A steam cylinder oil comprising a steam refined Mid-contlnent mineral oil having a Saybolt Universal viscosity at 210 F. of from about 165 seconds to about 200 seconds, about 8%;% of lard oil, from about 0.1% to about 0.2% lecithin, and from about 2% to about-4% of a residuum petroleum oil having a furol viscosity at 210 F. of about 800-900 seconds obtained from a crude petroleum oil of the Smackover type.

8. In the lubrication ofcylinders of steam engines the improvement comprising commingling with the steam supplied to such cylinders a lubricant comprising a hydrocarbon oil having a Saybolt Universal viscosity at 210 F. of from about 100 seconds to about 300 seconds, from about 5% to about 10% of a fatty oil, from about 0.05% to about 1%.of a complex glyceride phosphoric acid ester, and from about 1% to about 5% of a residuum petroleum oil having a furol viscosity at 210 F. of from about 750 seconds to about 950 seconds obtained from a predominantly na heating oil having a Saybolt Universal viscosity at 210, F. of from about 100 seconds to about 300 seconds, from about7% to about 9%of a fatty oil, from about 0.1% to about 0.5% of a, complex glyceride phosphoric acid ester, and from about 2% to about 4% of a residuum petroleum oil having a furol viscosity at 210 F. of from about 800 seconds to about 900 seconds obtained from a predominantly naphthenicpetroleum oil.

thenic petroleum oil, whereby an invert emulsion which preferentially wets the surfaces of the cylinders is formed with the steam.

9. The lubrication of cylinders of steam engines as described in claim 8 in which the fatty oil is lard oil, the complex glyceride phosphoric acid ester is a phosphatide, and the petroleum residuum is a residuum obtained from a crude oil of the Smackover type.

ELMIER WADE ADAMS. FREDERICK H. MACLAREN.

CERTIFICATE OF CORRECTION Patent No. 2, 73,755. April 17 1915.

ELMER WADE ADAMS, ET AL.

It is hereby certified that error appears in the printed specification of the above nnmbered patent requiring correction as follows: Page 2, first column, line lfl, inthe table fourth column thereof, for "98.15." read -89.LL-; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 19th day of June, A. D. 1915.

Leslie Frazer (Seal) Acting Commissioner of Patents.