US3075693A - Centrifuge filtration - Google Patents

Description

Jan. 29, 1963 R. L. DEGA 3,075,693

CENTRIFUGE FILTRATION Filed May `11, 1959 2 sheetssheet 1 IN VEN TOR.

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B m Z United States Patent @nice 3,075,693 Patented Jan. 29, 1963 3,675,693 CENTRHUGE FHJTRATEN Robert L. Dega, Utica, Mich., assigner to General Motors Corporation, Detroit, Mich., a corporation of Delaware Fiied May 11, 1959, Ser. No. 812,354 1 Claim. (Cl. 233-2) This invention relates to centrifuges for the treatment of uids and more particularly to centrifuges in which a filtration aspect is employed to enhance the effectiveness of fluid purification.

In the clarification of fluids containing high proportions of solids, it is often desirable to combine a filtration feature even though the solids tend to load or clog a centrifuge employed in the process, this clogging necessitating frequent dismantling and cleaning of the apparatus.

An object of the present invention is to provide an improved centrifuge in which a fiuid being clarified may be subjected to a filtering action. Another object of the invention is to provide a centrifuge in which a filtering element is incorporated to aid in the clarification and in which the filtering element is continuously relieved of contaminate simultaneous with the centrifugal action.

A feature of the invention is a hollow rotor having partitions dividing the interior into three chambers, vanes being located in at least one of the chambers to promote centrifugal action and consequent iiuid iiow into the other two chambers and bafiie means in one of the latter to aid in guiding a portion of the flow along one side of a filtering element.

These and other important features of the invention will now be described in detail in the specification and then pointed out more particularly in the appended claim.

In the drawings:

FIGURE 1 is a sectional View taken along the line 1 1 in FGURE 3 and showing a centrifuge in which the present invention is embodied, a portion of the casing for the power source being shown;

FIGURE 2 is an enlarged sectional view of a portion of the rotor shown in FIGURE l; and

FiGURE 3 is a sectional view looking in the direction of the arrows 3-3 in FlGURE 1 and taken at various llevels better to describe the construction.

The centrifuge disclosed is shown to comprise a lsupport casing as generally indicated at 10. This support constitutes a shell with a top platform 12 to which a cylindrical casing 14 is attached with its axis vertical. Within the casing 14 is mounted a casting 20 defining two flow passages 22 and 24. A pipe connection 26 extends loutwardly through the casing 14 and is joined to the casting 20 to cooperate with passage 22 in forming a flow inlet passage. A pipe connection 28 is similarly associated with the passage 24 to form an outlet passage. This connection also extends outwardly through the Wall of the casing 14.

The support encloses an electric motor, not shown in the drawings, but which motor is arranged to drive a vertical shaft 30. A suitable coupling 32 is joined to the upper end of the shaft 3i) and the upper end of the coupling is fixed to the end of a hollow shaft 34 which is journaled in a partition 36 separating the two passages 22 and 24. Openings 38 through opposite walls of the shaft 34 give communication between the interior of that shaft and the passage 22. The upper portion of the casting 20 is bored to receive a ball bearing arrangement 40 and a suitable sealing unit 42. The ball bearing and sealing arrangement cooperate in forming a leakproof journal of a downwardly extending sleeve or hollow shaft 44. The shaft 44 is open at its bottom end and surrounds the shaft 34 to define a discharge passage communicating with the outlet passage 24. The upper end of the sleeve 44 bears a ange 46 which bears down upon the inner race of the ball bearing 40 and which is fixed to the main casing 48 of a rotor by means of screws such as screw 50. A gasket 52 is interposed between the casing 48 and the Isleeve iiange to insure that no leakage occurs from the rotor. The casing 48 is centrally apertured as at 54 to form a continuing or registering passage with the discharge passage afforded by the shaft 44 around the shaft 34. The casing 48 of the rotor is located above an opening 54 formed in the casing 14 and the periphery of the casing 48 extends outwardly and is of greater diameter than the diameter of the opening 54. The top of the casing 48 is closed by means of a cover member 56 which bears a sealing gasket 58 and is held in position by means of a split ring 60 and screws such as screw 62. The split ring is so made as to tend to expand to a diameter greater than that of the cover member 56 and enter a groove 64 formed in the inner wall surface of the casing 48. A shoulder 66 is formed in the casing 48 determinng the exact location of the cover member within the casing. An opening 68 is formed in the cover member 56 in alignment with kthe shafts 34 and 44. Coaxial with this opening is a Calibrating ring 70 which is interposed between the cover `member 56 and an outlet ring 72 which is fixed to the cover member by screws such as the screw 74.

An annular trough 76 is mounted around the casing 14 and the annular outer wall of the trough is joined by means of an annular wall member 78 to a stiffening ring 80 which surrounds the upper end of the casing 48 but is spaced therefrom. A circular cover 81 is formed with a rolled edge 82 for detachable joinder to the upper marginal portion of the annular wall member 78.

The rotor cover member 56 is integrally provided with eight spaced and radially extending ribs 84. Each of these has one end terminating at the edge of the opening 68 and its other end conforming with or abutting the inner wall of the casing 48.

Partitions are formed in the rotor Within the casing 48. These partitions comprise a cuplike element 86 comprising two cylindrical walls 88 and 90 which are joined by an annular ring 92 and a bottom wall 93. The cupe like element cooperates with an inner coverr96 in defining a centrifugal chamber 98. The bottom wall 93 is apertured for connection of the chamber 98 with the upper end of the shaft 34. The cuplike element 86 is spaced from the rotor casing 48 to define a liquid chamber 96 as well as an annular passage 97 the inlet to which is divided in effect by lsixteen arcuate dirt passages and eight relatively restricted ports C as will further appear. The inner cover 96 contacts the ribs 84 to coact with the cover member 56 in defining eight radial dirt chambers 99 which connect the annular passage 97 to the outlet 68. These chambers 99 are shallow when considered in the direction of the rotor axis as may lbe seen in FIG- URE l.

Eight radial vanes 100 are located in vertical planes within the centrifugal chamber 98, the inner-edges of these vanes terminating at the junctions with the shaft 34 and their outer edges being welded to the walls 88 and 90.

A cylindrical lining 102 is arranged within the liquid chamber 96 beneath the level of the cylindrical wall 88. Eight varies 104 extend from the lining 102 and close to annular filter means 106 and four small varies 110 traverse the annular passage 97. Additional vanes 112, four in number, radially divide the liquid chamber 96 and extend from the annular filter means 106 to the lower end of the shaft 44. The vanes 110 lie in the same planes as do four of the vanes 100 and four of the ribs 84.

Thev vanes-112 lie in-the same planes as the other four vanesll);

The llter means 106 comprises laminated paper impregnated with a thermoset resin, this paper being sandwieliedfbetween two cylinders of perforated thin metal; Batlle meanscomprising eight imperforate plate members Hilaire arranged in series around theperiphery ofthe liquid chamber 96'. Each plate member has its verticaland opposed edges in'contact with the lining 102 andlthe adjacentplate members. An intermediate portion of veach plate member is constrained between the inne'f'edge of-a vane 104 and the llter means 106. The lower edgeflofeach plate-member 120 terminates at a level-121 short`l of the bottom Wall of the rotor.

Eight arcuate-openings 122 are formed in the partition orringl92-to connectthe'centrifuge chamber 98`with the liquid` chamber! 96 outside the balile means or plates 120; Each-opening lzzstraddles a vane 1th) and a Vane 1042 The baftlerrieanstherefor separate the peripheral zoneof the-liquidfchamber into `u'p-llow passages BA alternating with pai'rsofdown-flow passages A. The up-flow passages-Bleachcommunicates by means of a small triangular orilice C with the annular passage 97 leading lto thedirt-chambers-'98. Eachy orifice C is-partially defined by thellower peripheral edge of the cylindrical wall 8S; The inner portions ofl the rotorare lirmlyheldin their posit-ions *byl means of eight bolts 124 which extend through'the'inner coverY 96 andthe bottom wall-93 and are=threaded into the maincasing 48;

In operation of the device and assuming that the rotor is-'beingrotated by means oftheshaftll, contaminated liquidi's-pumped by way of'y the inner chamber 22 through theportsSS/intothe hollow shaft 34; This iluidllows upwardly'into the centrifugal chamber 98 where the eight radial vanes 100' impartr'otation-and enhance outward owo the/fluid. Solid matter willbe separated from the fluid 1aga-inst-thelin'ner' surfaces of the cylindrical walls 90 'and- 88 asthe liquid progresses to the extreme allowableld-iam'eters determined by the partitions. The liquid, thus partially claried,` then isV directedY downwardly through thelarcua-te openings122 into the passages A outside the baille plates 120. In those passages, it is subjectedto the maximum\ centrifugal force While being positively driven;- Furtherv separation of the fluid constituentstakes/place inV these passages 'with the primary or" lighter liquid ilowing downwardly and the secondary-lliquido'rcontaminate-is forced outwardly against the inner wall ofthe lining 102,-and then upwardly through the elongated arcuate? ports-D. The-lighter liquid does notlnormally'ow upwardly through the port D because of: a= dirtY build-up explained below; It flows downward throughbthe high centrifugal lieldY and beneath the edges 121 ofthe-battle platesf120 into the upwardly directed passagesB. In-thesepassages, the lighter liquid ilows through the filter means 166 whichprovides the proper degree of filtration-1 desired and within reasonable' liow rates. The pressureforcing; the lighter liquid through the filter means is created bythe differential radius lof inlet and discharge inherent in the centrifugeV construction., The filtering action under the high centrifugal field provides an eifective-and continual cleaning of the iltersurface preventingundue accumulation-of impurities thereon. This is accomplished beeauseextremely line particles will agglomerate and are more'easily passed upwardly to join the discharge from the arcuate ports D as the centrigual force acts on the continually incoming flow. This agglomerate is forced against the walls of the baille means but progresses upwardly to the triangular and restricted discharge ports C where there isa maximum build-up of centrifugal force. Once a dirt build-up in the annular passage 97 and the radial passages 99 is established, small additions of dirt within the rotor periphery will cause an equal amount of dirt or liquid to be discharged over the lip of the Calibrating ring 70. Dirt discharged over the top of the ring 72 is ultimately collected in the trough 76 and may be periodically or continuously removed as will be understood.

Fluid clarified by centrifugal action and also by the filtering action passes from the llltering -means 166 and while guided by the four vanes 112 in theliquid passage 96 is forced downwardly through the shaft 44 to the outlet passage 24 for discharge.

I claim;

A centrifuge including a hollow rotor mounted for rotation on a vertical axis, hollow shafts coaxial with said rotor and extending downwardly from the latter for admitting and discharging huid, the upper end of said rotor having an upwardly directed central outlet for discharging solids, partitions in said rotor dividing the interior thereof into a vaned centrifugal chamber and two other chambers all coaxialwith said rotor, said'centrifugal chamber being interposed between said two other chambers and connected to one of said shafts for receiving untreated fluid from the latter, one of the said two other chambers being connected to said rotor outlet for receiving and conducting solids to the latter and being shallow in the direction of the-rotor axis, the other of said two chambers being a liquid chamber surrounding said' one of said shafts, main large discharge openings arranged in a circula series in said partitions adjacent the periphery of said rotor and connecting said centrifugal chamber with the said liquid chamber, a series of other smaller discharge openings in said rotor located radially outside said main openings and adjacent the rotor periphery and arranged to connect said other two chambers, annular iilter means located radially inwardly of said series of main openings and dividing the interior of said liquid chamber, baille means surrounding said annular lter means and arranged to direct the ow of solids from said series of main discharge openings from said liquid chamber and upwardly to said `shallow chamber by way of said series of other smaller discharge openings and also to direct the flow of liquid downwardly and then into contact with the exterior of said filter means, and said liquid chamber being connected to the other of said shafts for discharging claried fluid from -within said filter means downwardly from said rotor.

References Cited in the lile of this patent UNlTED STATES PATENTS 1,750,364 Schmucking Mar. 11, 1930 2,710,718 Denman lune 14, 1955 3,022,937 Dega Feb. 27, 1962 FOREIGN PATENTS 336,865 Great Britain Oct. 23, 1930 439,816 Italy Sept. 28, 1948 584,538 Great Britain Ian. 16, 1947 s' kan

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