US2878995A - Centrifuge for liquids - Google Patents

Description

March 24, 1959 R. LQDEGA 2,878,995

' CENTRIFUGE FOR LIQUIDS Filed Aug. 24, 1953 2 Sheets-Sheet -l INVENTOR fioZar/QC". .5: a

ATTORNEY March 24, 1959 R. DEGA CENTRIFUGE FOR LIQUIDS 2 Sheets-Sheet 2 Filed Aug. 24, 1953 INVENTOR @0562? :96 BY 6 1; ATTORNEY United States Patent Ofiice 2,878,995 Patented Mar. 24, 1959 eraltMotors Corporation; Detroit, Mich.,.a .crporation;

vofDelaware Application August-24,1953; Serial-No; 376 014- 6 Claims. (Cl. 233-27) This invention relates to centrifuges and more particularly to centrifugal separators especially suitable for removing-solid particles or fine solid matter from oil or other liquids.

Difli'cultieshave heretofore been encounteredin removing dirt particles from oil in that filtering units used. for that purpose have become clogged andnot'reliable especially after long and uninterrupted periods of use. Centrifugal separators have been tried in. attempts to.

overcome the difliculties but turbulence in the fluidflow has heretofore resulted in considerable dirt or solid matter remaining suspended in the oil even after extensive treatment.

A primary object of the present invention is to provide. an improved centrifuge for removing impurities from liquids.

Another object is to provide a centrifuge in which impurities are definitely removed from a fluid and their return to contaminate that fluid is prevented.

Still another object is to provide a centrifuge which is' capable of eflicient operation for an extended periodof time and which is suitable for treatment of large amounts of liquid.

Another object is to provide a centrifuge which retains foreign matter as it is separated from a liquid and which centrifuge, while inoperative, may readily be disassembled for periodic removal of the retained foreign matter.

To these ends a feature of the invention pertains to a bowl mounted in trunnions and having an interior wall surface with a discharge opening therein, the surface preferably but not necessarily having, an angularity of from 25 to-35 degrees with the axis of the trunnions.

along theaxis of a centrifugein which the present invention is embodied, a portion of a power source being shown; and

Figure 2 is a sectional view taken along the line 2-2 ofFigure l.

The centrifuge includes a support or stationary cylindrical casing 10 which is provided with an annular ring 12 welded to one end and a larger annular ring 14 welded to and within the other end. A cover or end wall 16 is placed with its margin in fluid tight relation with the ring 12 and it is held in position by means of four suitably mounted bolts 18, each of these boltsbeing pivoted on a pin 20 supported between cars 22 which project from the ring 12. A ring 24 is threaded to the free end of each bolt 18 and this ring is provided with 2. a shoulder 25 adapted to bear against a notchedportion 26' protruding radially from the margin of the cover 16. The interior side of. the cover orend .wall16. isribbed as at 28jand the. centraliportion of the cover 16 is apertured at. 30' and. providedswith a bushing 32. in which: the trunnion K l-is journaled. The trunnion..3.4.isflanged at 36 and is attached by means of bolts 38.to a centrifuge bowl generally indicated at 40.

The bowl 40 is made. in two main parts'42 and44 which constitute not only the, bowl but apbulbous fluid flow separator 45 located therein and interposed between the trunnions. These parts areplaced in abutting relation at 46 and held togetherby means of a bolt 48 passing along the axis of the bulbousseparator 45. Two'flanged inserts 50 and 52 are utilized against which the nut and head respectively of the bolt 48- are adapted to bear. A

tube 54 is concentrically arranged with respect to the bolt 48 and acts as a reinforcing member or spacing means for the two sections 42. and44.

The part 44 of the bowl is formed with an annular flange 56 on the substantially cylindrical exterior of which is formed a groove for retaining an annular ring.

58. of sealing material. A radial; shoulder 60 is formed on the section 44 and bolted, to the shoulder by means of bolts 62"is a flanged member, 64 which forms a tron,-

nion for the. bowl. 40. In, orderifor the member 64 to perform its function it.is journaled within an. annular or passage 76 formed,- in. the, cover 70. The. end of the trunnion'64" is splined to the shaft, 80 of a motor 82- which is'supported on a flangev 34 joined to the cover 70byrneansof multiple ribs 86..

The section 42 of the bowl 40 bears twelve radial and internal ribs each of which, is in alignment with one of twelve corresponding radial ribs 102 in the section 44'. It will be noted that the trunnion. 34 and the trunnion 64'havefapertures at 104"and 1060f curved contour andalso that the ends of the ribs 100 and. 102 nearest the bowl axis terminate just short of these apertures. In this manner the main passage leadingthrough the centrifuge is divided alongits length and within the bowl 40 into an. annular arrangement or series of twelve smaller passages.

The ribs or vanes 100. are integral with: the bowl sec-- tion 42 and alsowitht one portion 110. of the bulbous fluid flow separator 45. The-vanes 102aare integral with the section 44 of the bowl 40 and also with a curved portion 114" which functions as a part of the bulbous separator 45.

A" single annular series of slots or first annular narrow slot arrangement is formed in the wall of the section 42 of the bowl and it will be noted that the interior surface of the wall, as it extends awayfrom the trunnion 34 to. and away from the slots. 120, is imperforate' and h'as an angularity of about 30 degreeswith the axis of the trunnions. Asfurther clarified hereinafter, this angle may be broadly varied within the purview of this inventiombut a minimum of 25 degrees to a maximum'of' 35 degrees is the preferred range.

The vanes 100 and 102' lie in planes passingthrough the trunnions 34 and 64. and the passages defined by the vanes are smoothly contoured as may be seen from Figure 1. A second annular series or arrangement ofopenings or slots 122 are. formed in the section 42 at smaller flow passages partially defined by the vanes 10.!) r

and 102 extend smoothly by the openings 120 and 122 with no abrupt changes in their dimensions which would interfere with the optimum laminar flow of the fluid. The curved portion 114'is recessed at 124 to receive an annular lip 126 of the portion 110.

An annular dirt housing 130 is attached to the bowl 40 by means of bolts 132 and this dirt housing is made in one piece with three annular portions 134, 136, and 138 which are snugly in engagement with the exterior of the bowl 40. The portion 136 is in the form of an annular and radial web with an inner edge engaging and closely conforming with the bowl 40 between the slots 120 and the slots 122. The portion 138 is in the form of an inturned flange which is adapted to contact the sealing ring 58 in fluid-tight relation. The annular web 136 divides the annular dirt housing 130 into two annular series of dirt compartments 140 and 142. Compartments 140 are separated by radial partitions 144 and compartments 142 are separated by radial partitions 146 in such a way that one compartment 140 of one series is in communication with one arcuate slot 120 and each compartment 142 of the other series is in communication with one arcuate slot 122.

It will be understood that the casing is non-rotatably mounted on a suitable support not shown. A vent port member 150 is provided at the bottom of the casing 10 to take care of any leakage which may pass by the bearing surfaces of the trunnions.

In operation, a supply of oil or other liquid to be cleaned is led by a suitable conduit to the aperture 30 and is forced in the direction of the arrows shown in Figure 1 and out from the trunnion 64 and the passage 76. During this operation, of course, the bowl 40 together with the housing 130 is rapidly rotated by the motor 82.

As the bowl 40 rotates, the fluid is caused to rotate because of the vanes 100 and 102. Centrifugal force selectively acts on the heavier particles of dirt and causes them to follow the outer surfaces defining the passages or channels leading through the bowl. The wall surface leading up to a dirt discharge slot 120 may form an angle with the axis of the trunnions or bowl which maybe varied considerably. Tests have shown, however, that if the wall surface leading to a slot or on both sides of a slot is at an angle with the axis of the trunnions and falls within the range of 25 to 35 degrees, such construction is preferable for optimum results in carrying out the present invention. When an angle within this range is employed, dirt is cleanly separated by effective action of centrifugal force and is concentrated at the wall surface preparatory to being picked off or removed from the laminar stream by the slots 120. If the angle is reduced unduly, the flow of fluid tends to carry the dirt particles with it or hold them on the wall subject to the action of the fluid turbulence which reintroduces the dirt into the fluid stream. If the angle is unduly increased, less dirt will be removed from the oil by the slot in some situations and in many cases it would be necessary substantially to increase the diameter and therefore the size of the unit.

It will be appreciated that in initially operating the centrifuge, compartments 140 and 142 immediately will fill with relativity quiescent fluid. This fluid will grad- -'ually be forced out and inwardly through the slots 120' and 122 into the general flow stream by dirt particles entering those slots and gradually filling the compartments. Dirt once entering the compartments 140 will not again enter the fluid stream as it is definitely trapped. If there were more than one localized area of entry for dirt for a given compartment 140 along the direction of the bowl axis then dirt could and would reenter the fluid stream because of the ensuing turbulence.

Compartments 140 are made larger than the compartments,142 as they receive most of the suspended matter or dirt. v

Any fine solid or foreign matter which may escape the slots 120 is caught by the slots 122 and positively trapped in the compartments 142 in which solids may accumulate and the cleaned fluid is then forced out through the trunnion 64 and passage 76 for use.

After a protracted period of use, the dirt housing 130 may be removed for cleaning. This may easily be done by removing the cover 16 and its conduit connection, removing the bolts 132 and pulling the housing out in the axial direction and free of the bowl 40. The cleaned housing may be easily reinstalled and no disturbance of the dynamic balance is necessary. A new housing may quickly be substituted when time is of the essence and this also may be done without disturbing balance.

From the above it may be seen that a device for efliciently removing foreign matter from large quantities of fluids, and from liquids in particular, has been provided and this device is simple and may easily and quickly be cleaned even though operating conditions may be adverse.

Having described my invention what I claim as new and desire to secure by Letters Patent of the United States is:

l. A centrifuge comprising a bowl mounted on hollow trunnions with a fluid flow separator interposed between the said trunnions, the wall of said bowl having a smoothly contoured inner surface, spaced vanes lying in planes passing through said trunnions and joining the said wall of said bowl to said separator, a housing encircling said bowl to form a compartment adjacent to the exterior of the latter and mounted for rotation therewith, an opening leading through said wall to said compartment, a portion of said wall extending away from one trunnion to said opening being imperforate and the inner surface of said wall portion having an angularity of from 25 to 35 degrees with the axis of the trunnions.

2. A centrifuge comprising a bowl mounted on trunnions with a bulbous smoothly contoured fluid flow separator interposed between the said trunnions and supported in spaced relation to the wall of said bowl, a housing with an imperforate exterior wall and fixed to said bowl and forming a compartment adjacent to the exterior of said bowl, an opening leading through said wall to said compartment, the facing surfaces of said wall and said separator defining the space between the latter adjacent said opening being characterized by smoothness of contour conducive to laminar How, and

" that portion of said wall immediately approaching said opening being imperforate and having an inner surface with an angularity of at least 25 degrees with the axis of the trunnions.

3. A centrifuge comprising a bowl mounted on two hollow trunnions with a bulbous fluid flow separator interposed between the said trunnions, radial vanes lying in planes passing through said trunnions and supporting said separator in spaced relation with the wall of said bowl to form a smoothly contoured main flow passage leading from one trunnion to the other, said passage being divided into smaller passages by said vanes but having no abrupt variations in dimensions inimical to laminar flow, a portion of the interior surface of said wall being tapered with an angularity of from 25 to '35 degrees with the axis of the trunnions, said wall portion being imperforate except for a first narrow and annular slot arrangement adapted for discharge of solid particles from the bowl, a second narrow and annular slot arrangement at the widest portion of the bowl in- "terior, housing means encircling said bowl and forming two annular series of compartments rotatable therewith, each of said slot arrangements communicating with one of said series of compartments, the compartments communicating with the first slot arrangement being larger than the compartments communicating with the second slotarrangement, said housing means being axially removable from said bowl, a stationary casing enclosing said bowl and housing and providing end Walls to serve as supports in which said trunnions are journaled, one of said end walls being removable, and means for rotating said bowl and housing means through one of said trunminus.

4. A centrifuge comprising a bowl mounted on trunnions, a bulbous and partially conical flow separator interposed between said trunnions, radial vanes connecting said separator to said bowl and cooperating with the latter to define smoothly contoured flow passages extending in path leading from one of said trunnions to the other, a detachable housing fixed to the bowl to rotate therewith and having chambers defined by an imperforate outer wall, at least one annular series of arcuate slots leading through the Wall of said bowl to said chambers, and said housing being removable from one end of said bowl.

5. A centrifuge comprising a bowl with a smoothly contoured inner wall, said bowl being mounted on trunnions with a bulbous fluid flow separator interposed between the said trunm'ons, radial vanes joined to the said separator and supporting the latter in spaced relation to the said wall of said bowl to form smooth walled passages divided by said radial vanes but conducive to laminar flow in a path leading through said trunnions, a housing removably attached to said bowl and forming a compartment adjacent to the exterior of said bowl, an opening leading from one of said passages through said wall to said compartment, that portion of said Wall extending away from one of said trunnions to said opening being imperforate and having an inner fluid contacting surface with an angularity of at least 25 degrees with the axis of the trunnions, and means for driving said bowl through one of said trunnions.

6. A centrifuge comprising a bowl mounted for rotation on its axis and supported on two trunnions, a bulbous fluid flow separator interposed between the said trunnions, radial vanes lying in planes extending through said trunnions and joining said bowl and separator, the inner surface of said bowl and the outer surface of said separator being smoothly contoured and cooperating with said vanes to define passages conducive to laminar flow from one of said trunnions to the other, a housing joined to and encircling said bowl to cooperate with the latter in defining compartments for receiving impurities, means for detachably securing said housing to said bowl to facilitate cleaning, the wall of said bowl having at least one opening leading from each of said passages to one of said compartment, inner surface portions of said bowl at opposite sides of said opening being imperforate and substantially coplanar to such an extent as to be capable of maintaining said laminar flow during separation of said impurities, and means for driving said bowl and housing through one of said trunnons and about said axis.

References Cited in the file of this patent UNITED STATES PATENTS 669,732 Ohlsson Mar. 12, 1901 2,126,864 Bath Aug. 16, 1938 2,519,971 LeClair Aug. 22, 1950 2,688,437 Monnet u Sept. 7, 1954

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