US2952329A

US2952329A - Device for de-aerating liquids

Info

Publication number: US2952329A
Application number: US692506A
Authority: US
Inventors: Richard G Cunningham; Donald E Dahlberg
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-10-25
Filing date: 1957-10-25
Publication date: 1960-09-13
Anticipated expiration: 1977-09-13

Description

Sept. 13, 1960 R. G. CUNNINGHAM ETAL 2,952,329

DEVICE FOR DE-AERATING LIQUIDS Filed Oct. 25,1957 2 Sheets-Sheet 2 N VEN TORS 14/70 2017460 A. DIV/ 48526 BY nited States Patent 055cc Patented Sept. 13, 1960 DEVICE FOR DE-AERATING LIQUIDS Richard G. Cunningham and Donald E. Dahlberg, Edwardsville, IlL, assignors to the United States. of America as represented by the Secretary of the Air Force.

Filed Oct. 25, 1957, Ser. No. 692,506

Claims. (Cl. 183--2-.5)

The present invention relates generally to devices for de-aerating liquids, such as lubricating oil, and, as illustrated herein, relates more particularly to a device wherein pressurized, aerated oil is utilized to energize a fluid motor which in turn is operatively connected to a centrifugal device which removes entrapped gases from the oil.

The present invention is concerned with the removal of entrapped gases from fluid such as lubricating oil to permit immediate re-use of the oil. Aerated oil is unstable, and after aeration has reached a relatively high level, the oil will froth and hence will not be in suitable condition for use as a lubricant. Foaming or frothing presents further difiiculties since the entrained air displaces oil in the pressure pump and consequently reduces the flow of oil to the engine at. lower altitudes but as the barometric pressure decreases the flow rate will at first decline and then fail completely as higher altitudes are encountered. I

The present invention has as one of its objects the provision of a self-energized device which is effective to remove entrapped gas from the liquid and wherein the gasfree liquid is returned for re-use in the lubrication system. To this. end, one feature of the invention resides in a device for separating gases from liquids having a liquid operated motor and a member forming the rotor of a,

centrifuge having an oil passage. into the outlet passage. of the rotor and also means for conducting separated gases away from the oil passage. The illustrated embodiment of the invention provides means which are effective to remove the air from the oil and for conducting the. freed gas away from the oil contained within annular passage in the centrifuge and conducting said freed gases to permit escape of the freed gases to the atmosphere.

The present device provides an effective construction, of relatively high efiiciency wherein large quantities of oilrnay be de-aerated by a unit of small size and weight.

Another object of the invention is to improve generally upon the construction and operation of devices for. deaerating liquids such as lubricating oil.

With the above and other objects and features in view, the invention will now be described with particular reference to the accompanying drawings which illustrate a preferred embodiment thereof and in which:

Fig. 1 is a schematic showing of a lubricating system of which the present invention forms a part;

Fig. 2 is a view in section of the device for de-aerating oil; and

Fig. 3 is a sectional view of an air pressure control valve.

Referring now to. the drawings, particularly Fig. 1, it will be noted that this figure illustrates schematically the various components which go to make up; a lubricating and de-aerating system. De-aerated oil, or substantially gas-free oil, is stored in a tank having a conduit 12 leading to an eduetor 14 and through a second conduit 16 to a pressure pump 18. The pressure pump 18 supplies lubricating oil under pressure through a conduit 20 to the lubricating system (not shown) of an engine 22.

The engine 22 is schematically shown in Fig. l and repreeating oil to the lubricating system of an internal combustion engine wherein the oil drains to a. suitable dry sump. As the oil collects in the sump, it is removed therefrom by a scavenging pump 24 through a conduit 26 to a cooler 28. The volumetric capacity of. the scavenging, pump 24 is substantially in excess of the capacity of the. pressure pump 18. The aerated cooled oil passes from the cooler 28 to a spring loaded by-pass valve 30, which is. so arranged that a portion of the aerated oil is fed directly to a fluid motor 32 which is coupled with a centrifuge 34 and a valve 30 also feeds aerated oil to by-pass the fluid motor 32 through a conduit 33 directly to the. centrifuge 34.

De-aerated oil flows. from the outlet end of the centrifuge 34 through a conduit 35 and back to the eduetor 14.. Thus, de-aerated oil under pressure. is fed through the conduit 16 to the pump 18 and then through the conduit 20 to the lubricating system of the engine 22.. Thegas or air contained in the oil originally was removed by the centrifuge 34 and, as will later become apparent, is, collected and passes through a. conduit 42 wherein flow of the separated gas is controlled by an air pressure regulating valve 40. As illustrated, the valve 40- is controlled. or regulated by a pressure sensing line 44 which is connected to the oil outlet conduit 35. The separated air under normal conditions of operation is returned to the oil storage tank 10 to avoid loss of oil droplets which may be. carried over. The inlet 16 to the pressure pump 18. is pressurized above local ambient pressure by the. scavenging pump 24. The eduetor 14 serves to pump into the closed loop to replace oil consumed by the. engine and to replace any oil carried from the centrifuge 34 by. the air vent line 46. The tank 10 is primarily a source of make-up oil.

As shown best in Fig. 2, the aerated oil which has been. used to energize: the liquid operated motor 32 enters the centrifuge34 through a passage 52 and mixes with aerated oil flowing through the by-pass conduit 33 and into the by-pass 50 to the angular aligned passage 52 to the cylindrical rotor 54 of the centrifuge 34- which is supported by bearings 56 located at each end of the cylindrical rotor 54 as will later be described.

A hollow shaft 57 is attached to the head plate or cover 58 of the rotor 54. A casing 60 is attached to the head 58 of the rotor 54 and surrounds the sleeve 57 just referred to above.. The other end of the rotor 54 is pro-- vided with an end cover 62 towhich the other end of the casing 60 is secured. The end cover 62 is supported on the right hand end bearing 56 which in turn is mounted. on another stationary sleeve 66.

The entrance passage 52 through which aerated oil passes form the motor 32 and into the centrifuge is provided with a short drive shaft which transmits torque to the. rotor 54. The head plate 58 of the cylindrical rotor is provided with an opening 72 which receives. one end connector 70 and is keyed thereto. Aerated oil passes. from alined radial openings 74, 76 in.- the sleeve 57 and the plate 58 and is guided toward the. other end of the rotor 54. by suitable guide vanes 80.

The aerated oil passes axially along the inner wall of the rotor 54 until it strikes a stationary circular plate 82 air is caused to escape through the tube 94 since the air pressure within the casing space 98 is less than the air pressure within the rotor 54. For a particular rotor speed and oil flow rate into the rotor, the oil level A or film thickness is maintained as the result of the relation of the periphery of the stationary circular plate 82 to the inner surface of the rotor 54 and by the air pressure within the rotor 54 which is controlled by the rate of How of freed air through the tube 42. If the air pressure in the outer shell becomes too high the thickness of the oil film in the rotor will be reduced and poor separation of oil and air will result. On the other hand, if air pressure in the outer shell is too low, the rotor 54 will tend to fill with oil and reduced separation of oil and air will result.

The centrifuge head 53 is provided with shoulder 98 within which the outer end of the casing 92 is supported by the head 53. This casing 92 surrounds the entire centrifuge and supports the outlet shaft 66 at the exit end of the centrifuge. Air that has been separated from the oil is collected within the central chamber of the rotor and is forced therefrom through a pipe 94 which has been provided with a central hole or opening 96. The pipe 94 is supported by and passes through the wall of the rotor 60 and leads to an annular space 98 between the walls of the enclosing casing 92 and the outer wall of the rotor casing 60. At the lower side of the casing 92 there are provided several openings 102 which communicate with an exhaust chamber 106 which is connected to the exit conduit 42 and through which the air and oil will escape to prevent internal flooding of the casing.

Referring now to Fig. 3, there is shown an air pressure control valve 40 into which the air enters from the centrifuge into the lower portion 108 of the valve through an opening 110. At the bottom of the valve there is provided an air exhaust opening 112 above which there is mounted a guide for the stem 114 of the valve 40. The valve 40 is provided with a valve seat 116 into which a conical portion 118 may be seated and which is effective to regulate the proper flow of air. The valve 40 is provided with a rod 120 which is connected with a plate 122 at the top of the valve. The upper rim of the plate 122 supports a bellows 124, the other end of which is secured to a plate 126 located in the upper portion of the valve 40.

The bellows 124 is normally urged to fully extended position by a compression spring 132 interposed between a lower plate 134 and the upper end plate 122 of the bellows 124. Lower plate 134 has a clearance hole 138 therein for allowing reciprocation of rod 120 therethrough and also to allow the air pressure which escapes by conical portion 118 to act on the interior of the bellows 124. When the back pressure of the .de-aerated oil through the conduits 44 is suflicient to move the valve 118 toward closing position, passage of air entering the valve 40 from the conduit 42 is reduced and subsequently stopped when the conical valve 118 is seated in the opening in the plate 116, The conical valve 118 may be moved toward open position either by building up air pressure within the bellows 124 or by a decrease in the back pressure of the oil in

conduits

35 and 44. Thus pressure is maintained within the centrifuge 34 at a sub stantially constant level.

Having thus described our invention what we claim as new and desire to secure to Letters Patent of the United States is:

t We claim:

1. A device for separating gases from liquids having in combination, an enclosing casing having inlet and outlet passages, a liquid operated motor powered by aerated liquid under pressure, a hollow rotor within said casing driven by said motor and having passages from the interior of said hollow rotor communicating with said in-' let passage, said rotor having axial guide vanes for guiding flow of said aerated liquid, a tubular member extending through said rotor in a direction generally perpendicular to the axis of rotation of said rotor, an opening in said member remote from the rotor wall through which gases separated from said liquid may be trans mitted between said rotor and said casing, means forming an exit passage in said casing for said separated gases, and means for conducting said gas-free liquid to said outlet passage.

2. A device for separating gases from liquids having in combination, an enclosing casing having inlet and outlet passages, a liquid driven motor powered by aerated liquid, a hollow rotor driven by said motor and located within said enclosing casing, means for directing said aerated liquid from said motor to the interior of said rotor, axial guide vanes on the interior of said rotor to direct deaerated liquid toward a rotor outlet passage, means for conducting gases freed from said aerated liquid to the space between said rotor and the enclosing casing and through the outlet passages in said enclosing casing, and means for delivering said gas-free liquids to said rotor outlet passage.

3. A device for separating gases from aerated liquids having in combination, an enclosing casing having inlet and outlet passages, a liquid operated motor, a hollow rotor operated by said motor and mounted within said enclosing casing, axially oriented internal guide vanes in said rotor to direct flow of aerated liquid received in said hollow rotor, said vanes falling short of one end of the rotor, and means in said rotor effective to direct the passage of said deaerated liquid away from said rotor and into said outlet passage.

4. A device for separating gases from aerated liquids having in combination, an aerated liquid operated motor, an enclosing casing including an end wall having an outlet passage therein, a cover member for the other end of said casing having an inlet passage therein for permitting passage of aerated liquid from said motor, a hollow rotor supported within said casing and having radial passages leading to the inner surface of the wall of the rotor into which said liquid is received from said inlet passage, a tubular member extending through the wall of said rotor and enclosed within said outer casing, stationary means forming a passage for said deaerated liquid, an annular sleeve mounted in said end wall for supporting said stationary means and for conducting deaerated liquid from said last-mentioned passage out of said casing.

5. A device for separating gases from liquids, an enclosing casing having an inlet passage for aerated liquid and separate outlet passages for gas-free liquid and the separated gases, a valve means connected to said outlet passages, a pressure responsive member in said valve means, said valve means having a first chamber connected to said outlet passage for gas-free liquid an a second chamber connected to said outlet passage for separated gases, said first and second mentioned chambers being separated from each other by said pressure responsive member, means for biasing said pressure responsive member, an outlet from said second chamber for the passage of separated gas therefrom, a valve member for controlling passage of gas from said second chamber, and means connecting said valve member and said pressure responsive means to vary the position of said valve member to maintain a predetermined pressure diiferential between the liquid pressure and the gas pressure in said outlet passages of said casing.

References Cited in the file of this patent UNITED STATES PATENTS 2,006,244 Kopsa June 25, 1944 2,441,631 Hills May 18, 1948 2,575,568 Topanelian Nov. 20, 1951 2,575,923 McMahan et al. Nov. 20, 1951 2,664,170 Walker et al. vDec. 29, 1953