US3061181A

US3061181A - Centrifuges

Info

Publication number: US3061181A
Application number: US776971A
Authority: US
Inventors: Fred P Gooch
Original assignee: Sharples Corp
Current assignee: Sharples Corp
Priority date: 1958-11-28
Filing date: 1958-11-28
Publication date: 1962-10-30
Anticipated expiration: 1979-10-30
Also published as: GB892702A

Description

Oct. 3o; 1962 F. P. GOOCH 3,061,181

CENTRIFUGES Filed Nov. 28, 1958 4 Sheets-Sheet 1 J :a :ln-F1115 sa Hg' l Il I| l|. -4 l|i |39 34 g i| '40 |58 |45 ,4| A 35 l 1 l E E i; --31 am l l l J l; q Ev la INVENTOR. FRED P. GOOCH A@ G #MK ATTORNEY Oct. 30, 1962 F. P. GoocH 3,061,181

CENTRIFUGES Filed No'v. 28, 1958 4 sheets-sheet 2 f v WW l INVENTOR. FRED P. GOOOH ATTORNEY Oct. 30, 1962 F. P. GoocH CENTRIFUGES Filed NOV. 28, 1958 4 Sheets-Sheet 3 INVENTOR. FRED P. GOOCH 'Y/wbwayim ATTORNEY United States Patent Olce i, 3,051,181 Patented Oct. 30, 1962 3,061,181 CENTRIFUGES Fred P. Gooch, Pine Ridge, Pa., assignor to The Sharples Corporation, a corporation of Delaware Filed Nov. 28, 1958, Ser. No. 776,971 8 Claims. (Cl. 233-7) This invention pertains generally to centrifugal separators, and particularly to centrifugal separators of the solids-discharge type. The invention pertains more particularly to solids-discharge type centrifuges that employ a plow or conveyor for the movement axially within the centrifuging zone of separated solids in effecting the discharge of the same from the rotor.

Centrifuges of the above-mentioned type having wide variation in structural detail are well-known in the art, but insofar as I am aware, all suffer from one or Ymore major limitations.

For instance, it is frequently desired to effect centrifugal separation of solids from a mixture containing a substance or substances of relatively high vapor pressure, e.g. a liquid solvent or diluent or product of relatively low boiling point. To attempt to conduct such a separation by centrifuging at atmospheric pressure would result in undue volatilization of the liquid, an undesirable eventuality for several reasons, among which are interference with eiicient separation of solids, loss of liquid by vaporization, and/ or escape of toxic and/ or `disagreeable vapors. Avoidance of the latter is of course highly desirable in any type of separation quite apart from relative volatility.

Sealing of a centrifuge to permit operation under elevated pressure and/or to prevent the escape of vapors is a Well-known expedient, but in view of structural limitations inherent in prior art solids-discharge centrifuges of the type in question, such sealing heretofore has been very difficult to satisfactorily accomplish. An outstanding feature of the invention resides in a novel structure, combination and larrangement of parts resulting in a highly effective and eiiicient sealing ideally meeting the requirements of continuous centrifugal separation, including such separation under relatively high elevated pressure conditions.

Another shortcoming in prior art solids-discharge centrifuges of the type in question is the absence of compactness and of design versatility to the extent essential to smooth running and avoidance of undue vibration, particularly at relatively high speeds. Another outstanding feature of the invention resides in a novel combination and arrangement of parts whereby smoother running at relatively high speeds is afforded, and undue vibration avoided.`

Another shortcoming in prior -art solids-discharge centrifuges of the type in question stems from the manner in which the influent is fed to the machine, and the eftluents withdrawn therefrom. Another outstanding feature of the invention resides in structure providing improvement in this respect.

Additional features of the invention will become apparent to persons skilled in the art as the specification proceeds, particularly in connection with the accompanying drawings in which:

FIGURE 1 is an elevation, partly in section, of =a centrifugal machine embodying the invention;

FIGUREI 2 is 'anV elevation, partly in section and shown broken, of the upper portion of the centrifugal machine of FIGURE l, and generally indicated on FIGURE 1 by the letter A;

FIGURE 3 is an elevation, largely 1in section and shown broken, of the upper central portion of the centrifugal machine of FIGURE 1, and generally indicated on FIG- URE 1 by the letter B;

FIGURE 4 is an elevation, partly in section and shown broken, of the portion of the centrifugal machine of IGURE 1 generally indicated on FIGURE l by the letter and FIGURE 5 is a broken sectional elevation of structure for the discharge of liquid from the centrifugal machine of FIGURE 1.

Referring now more particularly to FIGURE l, at is shown a centrifugal machine having an outer shell or framework 11 comprised of top 12, upper side portion 13, lower side portion 14, bottom 15, and base 16. Shell or framework 1-1 may be supported in any desired manner, eg. by brackets 17 engaging supports 18.

Within outer shell or other framework 11 is inner shell 20 comprised of upper portion Z1, liquid eluent receiving portion 22, and lower portion 23, shell 20 being so connected together and so disposed with respect to bottom 15, base 16 and casing Z4, the latter extending downwardly from rotary mechanism support mounted on top 12, as to provide a generally vapor-tight chamber 26 capable of being pressurized to lany desired elevated pressure.

Portions 21, '22 and 23 of `shell 210 may be secured together by any desired means, such as by screws or bolts, the assemblage being mounted on` and within shell 11 as indicated at 27, a sliding ifit lat 281, sealed by gasket 29, being provided to `allow for differential expansion and contraction between shells 11 and 210 below points of mounting 27. If desired, provision also may be made to allow for differential expansion and contr-action above the points of mounting 27, such as at the connection 31 between portion 21 of shell 2G and casing 24. Thus connection 31 may be in the form of a laterally and longitudinally slidable seal, such as to be hereinafter more particularly described.

The rotating mechanism of the invention is comprised generally of rotor 312, gear box 3131, drive shaft assembly 34 and pulley 35, said rotating mechanism being mounted and supported as a unit on or by rotary mechanism support 25. It is to be particularly noted that gear box 313 is connected directly to rotor y312, that drive shaft assembly 34 is directly connected to gear box 3131, that support 25 is positioned about drive shaft assembly 34 adjacent gear box 33, and that pulley or other driving connection 35 is connected to drive shaft assembly 34 adjacent to support 25, but on the opposite side thereof from gear box 33.

Gear box 3-3 may be of conventional or other design and as shown includes a sun gear 36 to be held stationary from the exterior. This is accomplished by connecting sun gear 316 to shaft 37 extending axially through dr-ivev shaft assembly 341, and .securing shaft 37 from rotation by aiixing it to bracket 38 attached to support 25.

Support 25, an embodiment of which will be hereinafter more particularly described, is exible in character so as to permit both pivotal and lateral movement to allow the rotating mechanism to accommodate its motion during rotation to the requirements of rotation about an axis passing through the center of mass, which requirements, in the case of unbalance, cause the rotating mechanism to rotate eccentrically, as is well-known.

Although as the result of careful balancing during` manufacture, the latter axis is virtually coincident with the geometric axis of the rotating mechanism, a certain amount of unbalance almost unavoidably creeps in during use, due to, e.g. (l) unequal wear on parts, (2) slight change in positionV of parts upon reassembly after disassembly for cleaning or repair purposes, and/or more importantly, (3) any unequal distribution of separated solids in the rotor during operation. The afforded freedom of movement of the rotating mechanism laterally and pivotally adequately provides to a highly practicable degree the required iiexibility necessary to the modified, ie. eccentric, rotary motion during unbalance. Ideally and preferably, the support 25 is not only flexible, but also resilient so as to embody a restoring or centering force urging the geometrical `axis of the rotating mechanism into a position coincident with the center line, or in other words, the position of the axis of rotation under perfectly balanced conditions.

Theoretically speaking, it is unnecessary to provide any support or restraining mechanism at the lower end of the rotating mechanism, that is, at its bottom. From a practical point of view, however, it is found to be highly preferable to provide mechanism at the bottom of the rotating mechanism limiting the degree of its free movement for starting and stopping purposes, this not being required during actual operation. Such mechanism limiting movement may take any shape, form or design, e.g. that of a drag, or of an annular bumper. The purpose is to restrict, and/ or absorb the energy of, any undue vibration or whipping which may occur during acceleration or deceleration of the rotating mechanism upon starting .and "stopping, In the drawings, an annular bumper is illustrated at 41 surrounding and spaced annularly and radially from lower end 42 of rotor 32.

5 Having described the basic features of the invention, detailed description will now be made of an embodiment thereof by way of illustration.

Referring now to FIGURE 2, a flexible and resilient support 25, as mounted on top 12 about drive shaft assembly 34, is illustrated in detail, the shaft assembly represented by numeral 34 and comprised of sleeve 34a surrounding and secured to shaft 34b being vertically supported for rotation in support 25 as shown, thrust bearings 43 and roller bearing 44 being provided between rotary shaft assembly 34 and non-rotating member 45 of support 25. Ca'p 46 which serves as a pulley for engagement by a belt is attached to shaft assembly 34 as illustrated at 48.

Member 45 is supported on top 12 through the medium of spaced annular rings 51 and 52 secured to circumferential rib 53 on member 45, outwardly projecting rings 51 and 52 overlapping annular member 54 secured to top 12, said member 54 projecting inwardly into the space between rings 51 and 52, with circumferentially spaced

resilient members

55 and 56 interposed between member 54 and each of rings 51 and 52, as shown.

Resilient members 55, as illustrated, are cylindrical and of rubber or other similar resilient plastic, whereas resilient members 56, as illustrated, are comprised of a plurality of circular frustoconical shaped pieces of metal, such as of spring steel, preferably arranged with bases opposed somewhat as illustrated for greater flexibility. Resilient members 56 also serve for vibration damping purposes by absorption of energy due to friction between the individual pieces of metal during flexing. Either or equivalent types of resilient members may be used alone or in combination, e.g. circumferentially in alternate relation, such as illustrated, which contemplates an even number of each, for example, 6 of each on each side of member 54 arranged alternately and evenly spaced circumferentially.

` Upon referring to FIGURE 3, it will be seen that the lower end of drive shaft 34 is secured to the upper face of gear box 33, e.g. as shown .at 61, and that sun gear 36 is connected to shaft 37 through an internally splined collar 62 which engages corresponding splines ori the ends of shafts 37 and `63, the latter being integral with sun gear 36, and journaled as shown.

The interior of gear box 33 is conventional in construction .and arrangement, its purpose being to provide relative rotational movement between rotor 32 and solids plow 64 disposed therein (see FIGURE 4).

Casing 65 of gear box 33 is shown connected to rotor 32 about their respective peripheries, lower face 66 of gear box 33 being secured to end plate 67 of rotor 32 as illustrated at 68, plate 67 in turn being secured against the end of rotor 32 by ring` nut 69 which threadedly engages rotor 32.

Output shaft 71 of gear box 33, on the other hand, is connected to solids plow or scroll 64, end 72 of shaft 71 (see FIGURE 4) being splined exteriorly for engagement of corresponding interior splines in annular-shaped member 73 which is connected to plow 64 as shown at 74.

Returning to gear box 33 (FIGURE 3), conventional construction provides for two planetary gear cages 75 and '76.

The planetary gears 77 of cage 75 mesh with sun gear 36 as well as with internal gear 78 on peripheral member 79 of gear box 33.

The planetary gears 81 of cage 76, on the other hand, mesh with sun gear 82 which is connected to gear cage 75 for rotation therewith as shown at S3, and also mesh with internal gear 84 on peripheral member 79.

Gear cage 76 is connected to output shaft 71 which in turn is connected to plow 64 as previously described.

The arrangement of gears in such as to provide a difference in speed of rotation between rotor 32 and plow `64, and, in the case illustrated in FIGURE 3, output shaft 71 and plow 64 rotate at a slightly slower speed than gear case 65 and rotor 32, the purpose and function of which will be hereinafter described.

I The centrifuging zone of the rotating mechanism is illustrated in FIGURE 4. As previously described, rotor 32 and plow 64 rotate at different speeds so as to provide a differential in rotation between the two parts.

Plow 64 may be of any desired design, conventional or otherwise, and as shown is comprised of a tubular base or central portion 86 upon which is mounted a screw 87 having a helical shape over one portion 88 and a spiral shape over another portion S9. The outer edge of helical portion 88 conforms to the interior shape of rotor 32 and is disposed closely thereto, and the outer edge of spiral portion 89 conforms to the interior shape of a member 91 arranged at the solids discharge end of rotor 32, and is disposed closely thereto.

At 92 is shown a solids discharge outlet, of which there may be any desired number spaced circumferentially, and at 93 is shown a liquid discharge outlet, of which also liele may be any desired number spaced circumferenia y.

Liquid discharge outlet 93 may be of any desired design, shape and construction. As shown it is comprised of nozzle holder 94 (see FIGURE 5) fitted in the peripheral wall of rotor 32 in a manner to project outwardly therefrom, and it is held in position by any suitable means, e.g. as shown. Nozzle holder 94 has an inner channel 95 communicating with the interior of rotor 32, and a discharge nozzle 96 of extremely hard abrasive-resistant material, e.g. Carborundum, carried and secured in position in communication with channel 9S by bushing 97. Nozzle 96 is preferably pointed so as to discharge in a direction opposite to the direction of rotation of rotor 32 sto as to recover power by jet action.

Liquid effluent before reaching liquid discharge outlets 93 must flow over the radially inner edge of annular dam 98 (see FIGURE 4) secured in position at the liquid effluent end of rotor 32 by any suitable means, e.g. as shown.

An essential to the discharge of drained solids from rotor 32 is that the inner circumferential edge of darn 98 must be at a greater radial distance from the axis of rotation than the radially outermost inner edge of solids discharge outlets 92, this being in accordance with the wellknown principle of operation of solid-discharge centrifuges of the general type under consideration, whereby the separated solids are brought closer to the axis of rotation than the level of `liquid from which the solids are separated, before dischargeof the solids from the zone of centrifugation. Thus before the discharge of solids, the solids are first removed from the liquid by being brought closer to the axis of rotation, and thereafter liquid drained or removed from the solids, the latter separated liquid 5, flowing back to the main body thereof. Solids are thus not only separated from liquid but also drained of liquid prior to the discharge of solids from the zone of centrifugation.

Dam 98 is shown removable and therefore interchangeable, thus making the depth of Iliquid in rotor 32 subject to adjustment by the use of` dams of different inner radii, having in mind, however, what has been said above with respect to the relative radial distances of Ysolid discharge outlet 92 and the inner edge of dam 98 from the axis of rotation.

The mounting of plow 64 for rotation Within rotor 32 is subject to wide variation in engineering design. As shown ybearings 1011 and 102 are provided at one end between extension 103 on lower face 66 of gear box 33 and output shaft 71, and bearing 104 at the other end between tubular base 86 of plow 64 and member 105 affixed to rotor 32.

Seals have been illustrated for the prevention of leakage to and from the various bearings to avoid contamination, and to and from the atmosphere for vapor or pressure sealing, but since their function and operation are so well known, in the interest of brevity, detailed description thereof will not be made.

, The interior 106 of base '16, which as shown is completely enclosed, and which also may be placed under pressure, serves, together with whatever receiver may be connected thereto underneath, as a receiving chamber for solids discharged through outlets 92.

Annular 4bumper -41 is mounted on a two-piece circularsupport 107 which in turn is supported by circumferentially -spaced ribs 108. Bumper 41 is comprised of a tixed back or outer annular portion 109, and an inner movable member 110 between which is interposed a rubber ring 111. Member 110 is shown provided with an interior ring '112 which conveniently is of graphite for friction reducing purposes. The radial spacing between ring 112 and lower end 42 of rotor 32 is conveniently between 3;/32 and 'l/s", e.g. 1/16".

Feed pipe 113 enters interior 166 of base 16 through opening 114, shown sealed or tight, then proceeds downward as shown at 115, and eventually upward as shown at 116, making a U-turn not shown, and is connected to centrifuge inlet pipe 117, the latter discharging into feed chamber 118. The feed slurry flows from chamber 118 through nozzles 119, of which there may be any desired number spaced circumferentia-lly, into the space between plow or 4scroll base 86 and the inner periphery of rotor 32, which space comprises the centrifuging zone.

The solids are thrown outwardly by centrifugal force, deposit on the inner periphery of rotor 32, and due to the differential in speed of rotation of rotor 32 and plow 64 and the shape of its screw 87, the solids are plowed toward solid outlets `92, from which they are discharged into interior 106, and drop down through base '16 into a receiver, not shown, attached to the bottom of base 16, preferably with a vapor tight seal for pressurizing purposes.

The difference in speeds of rotation of rotor 32 and plow 64 is usually made relatively small, e.g. between l() and 100 revolutions per minute, and, for any given speed of rotation of rotor 32, e.g. 2000 r.p.m., is determined by the relative sizes of gears in gear box 33.

At times it may be desirable to rinse the solids, particularly after being lifted radially inwardly out of the layer of liquid, such as with water. For such purpose rinse liquid inlet pipe 121 is provided which -leads to pipe 122. Pipe A122 surrounds and is spaced from pipe 117, and has an outlet 123 leading to chamber 124 having nozzles z125, of` which there may be any desired number spaced circumferentially. Nozzles 125 discharge into the centrifuging zone, preferably ata point where the solids have been moved radially inwardly out of the layer of liquid. Rinse liquid drains from the solids into the layer of liquid in the rotor, and is discharged along therewith over dam 98 and through liquid discharge outlets 93 into '6 liquid effluent receiving portion 22 of shell 20, from which the liquid eluent may be removed by any desired means, not shown.

In view of the new combination and arrangement of parts including support 25 and the position of the other elements with respect thereto and to each other, the rotating mechanism accommodates its motion readily and smoothly to the requirements of rotation about an axis passing through the center of mass, whether the position of the later is stable or unstable, i,e. whether conditions of unbalance are temporary or permanent, or constant or variable.

Resilient members

55 and 56 serve excellent-ly for affording both pivotal and lateral movement, neither of which in view of the new structural combination and arrangement of parts need be large. Thus the pivotal movement rarely need by hardly more than a few degrees, e.g. between 1/2 and 2, and the lateral movement rarely hardly more than 1/10", e.g. between M50 and 1/L00 from center during the eccentric rotation to meet the requirements of unbalance.

To complete the description of an embodiment of the invention which incorporates vapor sealing and/ or pressure sealing, reference will now be made to connection 31 between portion 21 of shell 20 and casing 24 which connection is in the form of a laterally slidable seal to permit lateral and pivotal movement of support 25 without interference by shell 20.

Portion 21 is provided at its top with an annular member 127 having an annular recess 128 closed by an annular ring 129 and in which is slidably disposed annular flange 13) of member 131 which slidably engages the bottom of casing 24. 'By the use of sealing gaskets at the various points indicated, e.g. at 132, a vapor-tight joint is made permitting not only relative lateral movement with ilexibility between portion 21 and casing 24 to accommodate lateral and pivotal movement of support 25, but relative longitudinal movement as well to allow for unequal expansion and contraction of shell or framework 11 and shell 20 above points of mounting 27.

The foregoing particular description has been made in connection with the use of -shell or framework 11 and shell 20` in order to demonstrate the ease with which the centrifugal machine of the invention may be made vapor and/ or pressure tight. It is to be understood, however, that the invention is not so limited, for it may be employed with or without aV surrounding vapor and/or pressure tight enclosure, as will be obvious.

Also the foregoing particular description has been made in connection with the use of a belt drive for driving the rotating mechanism, it being understood that any other means for imparting rotary motion to the rotating mechanism may be employed, e.g. gearing, or a direct drive.

When employing a belt drive, it is frequentlyV preferred to offset the belt pull or thrust With an equal, or substantially equal, and opposite pul'l or thrust imparted by any suitable means permitting free flexing of support 25. An arrangement highly suitable for the purpose is illustrated in FIGURE l wherein motor support is hinged at 136 to member 137 secured to portion 13 of shell 11. Turnbuckle 138 connects end 139 of support 135 to upturned extension 140 on bracket 38, e.g. as shown. By virtue of a right-hand thread on one end and a left-hand thread on the other end of turnbuckle 138, the turning thereof varies the distance between pulley 141 on motor 142 and pulley 35 for adjustment of the tension on or tightness of belt 143. By virtue of the construction including the ball and socket joints and the hinged arrangement at 136, support 25 is permitted to freely flex without disturbing the tension on belt 143, or the driving of the rotating mechanism, support 135 permitting the free flexing of support 25.

From the foregoing particular description it will be seen that, as compared to a solids-discharge centrifuge operating on a horizontal axis with two fixed bearings, such as disclosed in my U.S. Patent 2,703,676, the advantages of this invention include a structure and cornbination of parts permitting (1) ease of encasement for operation under high pressure; (2) the use of a single relatively small diameter seal for sealing such encasement; (3) the location of the seal at the end opposite and above the solids-discharge end, thus freeing the seal from the possibility of contamination; (4) the flexible mounting of the rotary mechanism resulting in smoother running at high speeds; (5) the placement of the gear box between the rotor and a single top support, making possible among other things the use of smaller diameter drive shaft and bearings, for the output shaft of the gear box does not pass through the drive shaft attached to the gear box and its associated bearing or bearings; (6) the placement of the gear box adjacent the rotor which in turn allows the output shaft of the gear box to be short and larger in diameter eliminating torsional vibration; (7) the discharge of solids in a manner whereby they fall by gravity into a receptacle, thus avoiding their buildup at the solids-discharge end of the rotor; (8) the use of a shorter feed tube to reduce the chance of the feed tube rubbing the rotor as the rotating mechanism passes through its resonant frequency or frequencies; and (9) the placement of the solid and liquid discharges with respect to each other so that possible leakage of one to the other is avoided.

Having particularly described the invention, it is to be understood that this is by way of illustration, and that changes, omissions, additions, substitutions and/or other modifications may be made without departing from the spirit thereof. Accordingly it is intended that the patent shall cover, by suitable expression in the claims, the various features of patentable novelty that reside in the invention.

I claim:

l. A centrifugal machine comprising a frame, a drive shaft, means for mounting said drive shaft on said frame in upright position at a single locus, said means providing for both lateral and pivotal movement of said drive shaft at said locus, a gear box having a casing, said casing supported on said drive shaft and extending downwardly therefrom, a rotor supported on said casing and extending downwardly therefrom, means for rotating said drive shaft, said drive shaft, said casing and said rotor being connected together for movement including rotation as a unitary structure, a plow rotatably mounted within said rotor, gearing within said casing, said gearing geared to the interior of said casing, said plow connected to said gearing for rotation by said gearing, means for controlling rotation of said gearing relative to said casing for effecting relative rotation between said plow and said rotor upon rotation of said drive shaft, means for feeding a mixture of liquid and solids into said rotor, means for discharging separated liquid from said rotor, and means for discharging separated solids from said rotor.

2. The centrifugal machine of claim l wherein the firstmentioned means surrounds the drive shaft and resiliently mounts the drive shaft on the frame.

3. The centrifugal machine of claim 1 which includes means positioned at the lower end of the rotor for limiting pivotal movement of the unitary structure.

4. A centrifugal machine comprising a frame, a drive shaft, means surrounding said drive shaft for resiliently mounting said drive shaft on said frame in upright position at a single locus, said means providing for both lateral and pivotal movement of said drive shaft at said locus, a gear box having a casing, said casing supported on said drive shaft and extending downwardly therefrom, a rotor supported on said casing and extending downwardly therefrom, means positioned on the opposite side of said first-mentioned means from said gear box for rotating said drive shaft, said drive shaft, said casing and said rotor being connected together for movement including rotation as a unitary structure, means positioned at the lower end of said rotor for limiting pivotal movement of said unitary structure, a plow rotatably mounted within said rotor, gearing within said casing, said gearing geared to the interior of said casing, said plow connected to said gearing for rotation by said gearing, means for controlling rotation of said gearing relative to said casing for effecting relative rotation between said plow and said rotor upon rotation of said drive shaft, means for feeding a mixture of liquid and solids into said rotor, means for discharging separated liquid from said rotor, and means for discharging separated solids from said rotor.

5. A centrifugal machine comprising a frame, a drive shaft, means surrounding said drive shaft for resiliently mounting said drive shaft on said frame in upright position at a single locus, said means providing for both lateral and pivotal movement of said drive shaft at said locus, a gear box having a casing, said casing supported on said drive shaft and extending downwardly therefrom, a rotor supported on said casing and extending downwardly therefrom, means positioned on the opposite side of said first-mentioned means from said gear box for rotating said drive shaft, means for mounting said last-mentioned means to follow pivotal and lateral movement of said drive shaft, said drive shaft, said casing and said rotor being connected together for movement including rotation as a unitary structure, means positioned at the lower end of said rotor for limiting pivotal movement of said unitary structure, a plow rotatably mounted -within said rotor, gearing within said casing, said gearing geared to the interior of said casing, said plow connected to said gearing for rotation by said gearing, means for controlling rotation of said gearing relative to said casing for effecting relative rotation between said plow and said rotor upon rotation of said drive shaft, means for feeding a mixture of liquid and solids into said rotor, means for discharging separated liquid from said rotor, and means for discharging separated solids from said rotor.

6. The centrifugal machine of claim 5 having a vapor tight enclosure for the rotor.

7. The centrifugal machine of claim 5 having means for rinsing solids with liquid in the rotor after initial separation of said solids from liquid in said rotor.

8. A centrifugal machine comprising an upright drive shaft, a gear box having a casing, said casing supported on said drive shaft and extending downwardly therefrom, a rotor supported on said casing and extending downwardly therefrom, said drive shaft, said casing and said rotor being connected together as a unitary structure, means for mounting said unitary structure for rotation and for lateral and pivotal movement solely at a locus positioned above said gear box and about said drive shaft, means for rotating said unitary structure, a plow rotatably mounted within said rotor, gearing within said casing operatively connected to said casing, said plow operatively connected to said gearing, means for controlling rotation of said -gearing within said casing for effecting relative rotation between said plow and said rotor upon rotation of said unitary structure, means for feeding a mixture of liquid and solids into said rotor, means for discharging separated liquid from said rotor, and means for discharging separated solids from said rotor.

References Cited in the file of this patent UNITED STATES PATENTS 706,088 McCornack Aug. 5, 1902 2,616,620 Zimmerman Nov. 4, 1952 2,625,321 Glasson Ian. '13, 1953 2,703,676 Gooch Mar. 8, 1955 2,862,658 Dahlgren Dec. 2, 1958 k2,867,378 Harlow Jan. 6, 1959 FOREIGN PATENTS 1,002,689 Germany Feb. 14, 1957 1,020,930 Germany Dec. l2, 1957