US2401079A - Centrifugal deaerator - Google Patents

Description

y 1946- 1.. D. JONES ET AL CENTRIFUGAL DEAERATOR Original Filed July 4, 1942 m m. m N I Leo D. Jones John lSQI'eH. BY W M ATTORNEY Patented May 28, 1946 A UNlTED STATE CENTRIFUGAL DEAERATOR Leo D. Jones, Philadelphia, and John J. Serrell, Wynnewood, 'Pa., assignors to The Sharples Corporation, Philadelphia, Pa., a corporation of Delaware Original application July 4, 1942, Serial No. 449,830. Divided and this application July 19, 1943, Serial No. 495,262v

2 Claims. (Cl. 183-25) The present invention pertains to a centrifugal apparatus for deaerating liquids.- It will be described for purposes of illustration and convenience in relation to the lubricating system of an aviation engine, since that is the purpose for which it was originally conceived, although it has other applications.

' This application is a, division of'our prior application Serial Number 449,830, filed July 4, 1942'.

The lubricating system of an airplane engine consists of an oil storage tank, a conduit from the storagetank to the engine, a feed pump on In the preferred form of the invention, the

. centrifugal deaerator consists of a non-rotating or in the engine for pumping oil to the various I parts of the engine to lubricate it, a sump in the engine into which the oil drains from the various parts of the engine, a scavenge pump for pumping oil from the sump, a conduit from the scavenge pump to an oil cooler, an oil cooler and a conduit back to the oil storage tank. The system may include additional items such as a relief valve to by-pass oil around the cooler under certain conditions, a thermostatic valve for accomplishing this same purpose, and/or a centrifugal separator for purifying the oil after use, but the elements discussed above are the important ones, insofar as the background of the present invention is concerned.

The scavenge pump ordinarily has a displacement from two to three times as great as the oil feed rate of the feed pump in the case of radial engines, and in the case of in-line engines, there are usually two scavenge pumps, one at each end of the crankcase, each of these pumps having a displacement at least twice as great as that of the feed pump. This relationship of capacities between the scavenge pump or pumps and feed pump is necessary to insure the continuous removal of all of the oil which drains into the sump. A necessary incident to this relationship, however, is the fact that vapor from the crankcase is pumped by the scavenge pump or pumps together with the oil through the oil cooler and into the storage tank. The pumping ofthis vapor through the oil cooler increases the drop in pressure through the cooler and the load on the scavenge pump or pumps, and complicates the problem of cooling the oil.

In order to solve these and other problems, a centrifugal deaerator is provided which may be" interposed in the line of flow from the scavenge pump to the oil cooler.

tank around the interior surface of which the oil flows in a rotating motion during its passage from entrance to exit of the tank in a longitudinal direction. This tank is preferably provided with a valve controlling discharge or gas or vapor from a central portion of the tank, after removal of this gas or vapor under the influence of centrifugal force, and the opening and closing of this valve are controlled by the thickness of the layer of liquid passing along the interior wall of the deaerator. 'Thus, when the wall of liquid exceeds a predetermined thickness, the actuating mechanism moves the deaerator valve to a position preventing discharge of gas from the tank, and when this wall recedes again to a permissible thickness, the valve is again opened and discharge or gas resumed.

A better understanding of the details of the invention will be had by reference to the following description in the light of the attached drawing, in which,

Figure 1 is a cross sectional view through a preferred form of deaerating apparatus, and

Figure 2 is a plan view of the apparatus of Figure 1 with parts broken away to illustrate a valve detail.

Referring to the drawing by reference characters', the deaerator consists of a tank Iil provided with an interior surface II which is preferably circular, and which may be cylindrical or frustoconical .as shown. This tank is provided with an inlet connection i2 for injecting oil tangentially into the tank along the surface II in a direction having a longitudinal component toward the tangential outlet l3 which receives the oil.

after the gas has been separated bycentrifugal force due to rotating movement of the oil during passage along surface II from entrance to exit.

The tank In is provided with an end plate I 4,

which is removably mounted to permit access to the interior of the tank. This end plate is provided with a central opening to receive a housing l5 for a packing gland, this housing being secured to the end plate by bolts IS. A hollow'tube I1 is slidably mounted in a central bore of the housing IS, the upper end of this tube extending to a position within the tank I0, and this position being adjustable by longitudinal movement of the tube.

opening in the otherwise closed upper end of the tube H, and preventsfurther discharge of air so upper end of the tube l1, and the upper end of I the valve is urged downwardly and held in con-' tact .with the upper end'of the tube I! by the spring 22. The lower end of the spring 22 is se- "cured in position longitudinally with respect to the tube I! by the nut 23, which may be locked by nut 24, both of these nuts being threaded to the tube l'l. These nuts provide a method of securing the spring in position longitudinally, and also a method of altering the tension on the spring, as will be evident from inspection of the drawing. A stop pin 25 is secured to the tube ll adjacent the bottom of the valve 2 l, and this stop pin coacts with an abutting surface 25 of the lower end of the valve to secure the valve in open position under the influence of the spring 22 until accumulation of a predetermined thickness of an annular layer of liquid along the interior of the wall II, as will be evident from further discussion of details by which this result is accomplished. A plurality of wings 21 extend outwardly from the cylindrically extending portion of the outer surface of the valve 2!, and this valve is also provided with a cylindrically extending portion above the upper end of the tube H, in order to minimize leakage of oil into the tube I? by splashing. When the abutment 2B is in contact with the pin 25, an opening 28 in the upper, otherwise closed, end 29 of the valve 2! registers with an opening in the upper end of the tube l! to permit discharge of gas through these registerin openings and the tube ll. When the abutment 26 is moved in a counterclockwise direction-away from the pin 25, on the' other hand, these openings are brought out of registry with each other, with the result that the valve connection and possibility of discharge of gas through the tube I1 is closed, much, after the fashion of a talcum powder can.

In the operation of the above apparatus, the mixture of air and oil, which may be under pressure derived from the scavenge pump, enters through the tangential inlet pipe I2. The mixture flows around the inner wall ll of the tank l0, during its passage-from the inlet l2 to the outlet l3, and this rotating flow causes separation of air toward the center of the tank under the influence of centrifugal force. After being relieved of its air in this manner, the oil leaves the tank through the tangential outlet I 3. The air flows through the hole 28 and registering hol in the top of tube l1, and escapes from the apparatus through this tube. So long as the valve is maintained in open position by the action of the spring 22 in holding the abutment 26 against the pin 25, the air will discharge rapidly through the valve and tube IT. During this operation, the thickness of the body of oil rotating within the surface I l during its passage longitudinally along that surface will gradually increase until the inner surface of this layer strikes the wings 21 and causes these wings to move in a counterclockwise direction against the influence of the spring 22. This rotary movement of the wing 21 under the impelling effect of the rotation of the body of oil within the tank causes the opening 28 to be moved out of registrywlth the enacting 76 mixture around the wall of said chamber. means longa' this condition continues to prevail. As the operation continues after this condition is reached, the pressure in the central part of the tank In will increase, due to the fact that the released air cannot be discharged through the tube l1, and this increase in pressure will cause an increase in the amount of .oil discharged through tangential outlet I3, with the result that the-amount of discharge will ultimately exceed the amount of feed, and the inner surface of the stratum of oil within the surface II will again recede. When this happens, the spring 22 will again return the valve to open position, with the result that the air can again be discharged through tube. l1.

The above description of the operation of the centrifugal deaerating apparatus is somewhat idealized for the sake of simplicity of explanation. As a. matter of fact. in the actual operation of the apparatus, the valve may not be moved the eifect of wings 21 in moving it to closed position. As a matter of practical operation, however, the effect of the valve in permitting discharge of gas, but preventing discharge of liquid through tube l! by preventing accumulation of too deep a stratum of liquid within the tank is the same, regardless of whether the valve actuating mechanism effects actual successive closing and opening of the valve, or merely the attainment Of an equilibrium condition which builds up a pressure within the center of the tank sumcient to bring the rate of discharge of oil through conduit 13 to the approximate rate of feed thereof through the conduit l2.

Various modifications are possible within the scope of the invention, and we do not therefore wish to be limited except by the scope of the following claims.

We claim:

1. In a centrifugal machine for separating gas from liquid, the combination comprising, a centrlfugal separating chamber in the form of a stationary tank, means for feeding a mixture of liquid and gas to said chamber and rotating said mixture around the wall of said chamber, means for discharging liquid-from an outer portionof H said chamber continuously during normal operation of said machine, means for discharging separated gas from an inner portion of said chamber. a, valve controlling said discharge of gas, and a rotatable actuating member within said chamber adapted to receive motion by contact therewith of liquid rotating within said chamber upon accumulation of said liquid beyond a predeter mined annular thickness in sald'chamber, and means controlled by said actuating member for operating said valve, whereby'dlscharge of gas is permitted untilsaid liquid has attained such predetermined thickness and prevented when said liquid has attained such predetermined thickness. 7

2. In a centrifugal machine for separating gas from liquid, the combination comprising, a centrifugal separating chamber in the form of a stationary tank, means for feeding a mixture of liquid and gas to said chamber and rotating said outwardly from a central portion of said tank 10 I and designed to. be impacted by liquid rotating in said tank when said liquid exceeds a predetermined thickness in said tank, whereby discharge of gas is permitted until s'aid liquid has attained such predetermined thickness and prevented when said-liquid has attained such predetermined thickness.

LEO D. JONES. JOHN J. SERRELL.

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