US3085743A - Sludge discharging centrifugal separators - Google Patents

Description

April 16, 1963 P.$TE1NACKER ETAL 3,085,743

SLUDGE DISCHARGING CENTRIFUGAL SEPARATORS Filed Jan. 16. 1959 12 H r' 5.3L I80. 29 INVENTORS PETER STEINACKER v HEINRICH HEMFORT as 30 ATTORNEYS 3,085,743 Patented Apr. 16, 1963 3,085,743 SLUDGE DISCHARGING CENTRIFUGAL SEPARATORS Peter Steinacker and Heinrich Hemfort, Oelde, Westphalia, Germany, assignors to Westphalia Separator AG., Oelde, Westphalia, Germany, a German corporation Filed Jan. 16, 1959, Ser. No. 787,309 Claims priority, application Germany Feb. 11, 1954 Claims. (Cl. 233-) This invention relates to improvements in sludge discharging centrifugal separators, and is a continuation-inpart of copending US. application, Serial No. 433,708, filed June 1, 1954, now abandoned.

Centrifugal separators which have bowls from which accumulated sludge may be periodically discharged are known. These separators may have a centrifugal bowl with peripheral sludge discharge openings which may be opened and closed by an axially movable sleeve valve. The sleeve valve may be hydraulically operated in one or both directions.

For this purpose the bowl may have a bottom insert which forms the bottom surface of the bowl interior. This bottom insert has a lower surface positioned in spaced relationship to the upper surface of the bottom portion of the bowl casing. The sleeve valve has an inwardly extending flange or plate which is positioned in this space and divides the same into an upper opening chamber and a lower closing chamber. The control is effected by introducing a control liquid such as water into the opening chamber above the flange, or into the closure chamber below the flange. Due to the centrifugal force of the rotating bowl, the liquid acts under pressure in these chambers. There is, thus, produced in one of the two chambers an excess pressure which effects the downward or upward movement of the sleeve valve whereby the sludge discharge openings are exposed or closed.

Various embodiments of such control systems are known. In some embodiments both chambers are filled independently of each other with control liquid through channels or holes while in other embodiments, the chambers have a common feed channel.

In the case of centrifugal separators of the latter type, the opening chamber may have small discharge conduits at its outer periphery through which the control liquid may leave the chamber. In order to effect opening of the sleeve valve for the discharge of the sludge, more control liquid is introduced into the opening chamber than can be discharged through its peripheral conduits. As a result, the liquid builds up in the opening chamber and a centrifugal pressure head is formed which forces the inwardly extending flange and the sleeve valve downward and displaces the control liquid present in the closure chamber. After the sludge has been discharged, the control liquid introduced into the opening chamber is throttled or interrupted so that the same may discharge through the peripheral conduits. The control liquid at the same time is allowed to build up in the closure chamber so that the pressure of the centrifugal head in this chamber exceeds that in the opening chamber and the sleeve valve is moved upwardly to close the sludge discharge openings. In general, water is used as the control liquid.

In order to effect a dependable closure of the sleeve valve, a continuing small feed of water must be maintained after the refilling of the closure chamber particularly when centrifuging at high temperature in order to equalize any losses occurring by evaporation, leakage or the like. In this connection passage of the control water from the closure chamber into the opening chamber is permissible to a certain extent inasmuch as this water again discharges out of the peripheral conduits. If this continuous feed, however, exceeds the discharge rate through these conduits, the control water collects in the opening chamber and will force the sleeve valve downward and hold it in the open position. If, on the other hand, the continuous admission to the closure chamber is less than the amount lost by evaporation, etc., the amount of control water in the closure chamber will gradually decrease to below the amount required to maintain the sleeve valve closed.

A further disadvantage of conventional sludge discharge centrifugal separators is the fact that the opening of the sludge discharge outlets often takes place too slowly. This occurs because the mass in the closure chamber is somewhat inwardly displaced upon moving the sleeve valve to opened position, increasing the working surface area of said sleeve valve as it so moves. Further more, an increase in countcrpressure results in the closure chamber acting to retard the opening of said valve, necessitating additional filling of the opening chamber and an increase in the filling time. These actions delay rapid opening of conventional sludge discharge outlets. As a consequence, the rinsing liquid fed to the drum for removing the sludge may break through the cake of solids formed along the separator wall during sludge separation, thereby causing any advantageous pressure build-up to be lost. Under these conditions, the solids may be only partially expelled so that strong imbalances of the rotating drum may occur.

It is an object of the present invention, therefore, to overcome the above disadvantages of variations in rate of feed of the control liquid to the opening chamber and slowly opening sludge discharge outlets.

It is another object of the invention to provide a sludge discharge centrifugal separator construction wherein the closure chamber has a smaller radially extending working surface area and a correspondingly greater annular or longitudinally extending working surface area with respect to the axis of rotation of the separator.

It is a further object of the invention to provide a closure chamber construction whereby the opening and closing of the sludge discharge openings of a centrifugal separator may take place rapidly, particularly in moving the sleeve valve into opened position.

Other and further objects of the present invention will become apparent from a study of the within specification and accompanying drawing in which:

FIG. 1 shows an embodiment of a centrifuge in accordance with the invention, with the sleeve valve in the closed position, and

FIG. 2 shows the embodiment shown in FIG. 1 with the sleeve valve in the open position.

The centrifugal separator, in accordance with the invention, has a closure chamber developed as a storage chamber which will not force all of the material used for effecting the closing actuation therefrom even when the sleeve valve is in the open position. At least a predetermined portion of the mass which is flowable or deformable under centrifugal force is permanently contained in the closure chamber. This mass, for example, may consist of a liquid which does not evaporate even at increased temperature or a plastic or elastic mass.

The closure chamber should be outwardly sealed, but may he provided with an opening in its end portion a predetermined distance from the axis of rotation of the centrifuge through which the centrifugally deformable closure material may be introduced and from which the excess of this material over the predetermined amount desired may be discharged upon the first sludge removal.

Since at least a predetermined amount of the centrifugally deformable mass used for the closing actuation of the valve is substantially permanently positioned in the closure chamber and is merely deformed outwardly upon closing actuation and flattened out upon opening actuation, no feed channel is required into the closure chamber, and the closure chamber no longer need be in communication with the opening chamber.

The inwardly extending flange which is connected to the sleeve valve preferably extends to adjacent the hub of the centrifugal bowl so that the opening liquid may exert a force on a larger area than in previously known embodiments. The closure material, furthermore, acts in the open position of the sleeve valve on a larger area than in the closed position. Thus, this material will exert a larger force at the beginning of the upward movement of the valve where it is needed to overcome the starting friction.

When an elastic material as, for example, rubber is used as the closure material, a preliminary stressing of this material in the form it takes when the sleeve valve is closed may be effected so that the initial force exerted on the sleeve valve in its movement from the open to the closed position is further increased to overcome the starting friction which, as is well known, is greater than the sliding friction.

It has been found also in accordance with the present invention that by providing an increased distance, in a longitudinal direction with respect to the axis of rotation, between the flange connected to the lower portion of the sleeve valve and a portion of the bottom of the bowl casing, as by an annular extension in said bowl casing bottom, when the sleeve valve is in closed position the working surface area of the deformable mass in the closure chamber during rotation is only slightly increased radially inwardly upon movement of the sleeve valve to the opened position. Moreover, in accordance with the invention, the effective surface area on which the closing deformable mass may exert its force is considerably diminished in the peripheral portion of the closure chamber farthest from the axis of rotation, that is, where the force of said mass is greatest, upon moving the sleeve valve to opened position, while the remaining effective surface area as aforesaid is only slightly increased in a direction towards the axis because of such annular e'xtension. Consequently, upon movement of the sleeve valve into opened position, as when liquid is conducted to the opening chamber in conventional manner, the counteracting force of the deformable or flowable mass in the closure chamber is considerably less than that exerted in conventional separators, permitting speedy movement of the sleeve valve from closed to opened position. Conversely, it will be seen that upon dis-continuing liquid to the opening chamber, due to the centrifugal force acting on the deformable or flowablc mass, the sleeve valve will be forced toward the closed position enabling more and more of said mass to occupy the peripheral portion of the closure chamber, whereby said valve will be quickly and completely forced to closed position.

Constructions in accordance with the present invention, such as those above described, therefore, favorably provide for the etlicient and rapid opening and closing of the sludge discharge openings, utilizing the centrifugal force of the separator to advantage. Specifically, the cake of solids deposited in the drum during separation of the sludge from the accompanying liquid will be completely discharged from the drum under the pressure of the rinsing liquid, eliminating any possible imbalancing of the drum, since the sleeve valve is quickly moved into opened position. Conversely, the sleeve valve is quickly moved into closed position, since the deformable mass passes immediately into the space formed in the periph eral portion of the closure chamber, where the force of said mass is greatest, upon initial movement of the sleeve valve toward the closed position. Because of such great force the sleeve valve is caused to complete its movement to the closed position rapidly, without noticeable displacement of the deformable mass toward the peripheral portion of the closure chamber.

In the preferred embodiment of the invention, wherein a llowable mass is used in the closure chamber, one or more limiting exit tubes or channels connecting said closure chamber with the outside are provided whereby a given quantity of said mass will always be present in said chamber. These tubes project into said chamber a predetermined distance, or are positioned at a point in the chamber wall a given distance from the axis, so that a sufficient quantity of tlowable mass will always be present in said closure chamber.

Among the deformable or flowable mass materials which may be used in accordance with the invention are any flowable plastic and elastic materials, any deformable plastic and elastic materials, water, and water-based deformable or llowable materials, all of said materials being capable of deforming or flowing under centrifugal force and preferably being liquid.

The term llowable mass or flowable material as used in the appended claims is meant to embrace and include both flowable and deformable masses and materials of the type immediately hereinabove set forth.

It will be seen, therefore, that the present invention advantageously provides a closure chamber in centrifugal separators having a widened annular space portion into which the deformable or llowable mass may be directed during movement of the sleeve valve into opened position with only a slight increase in working surface area in a radially inward direction. Furthermore, the invention provides such a closure chamber having a varying volume peripheral portion in which the working surface area decreases during movement of the sleeve valve to opened position correspondingly decreasing the force of the flowable or deformable mass thereat, and increases during movement. of said valve to closed position correspondingly increasing the force of said mass thereat. Consequently, the closure chamber construction of the invention enables the sleeve valve to respond rapidly to open and close the sludge discharge openings, due to the immediate decrease in the force of the fiowable or deformable mass upon moving said sleeve valve to opened position and the immediate increase in the force of said mass upon moving said sleeve valve to closed position, respectively.

The invention may be further described in greater detail with reference to the embodiment shown in the accompanying drawings.

The centrifugal bowl'is composed of the lower casing part 1 and the upper casing part or cover part 2, which are connected to each other by means of the locking ring 3. The bowl is mounted for rotation with thespindle 28 in the conventional manner. The bowl casing is provided with peripheral sludge discharge openings orports 20. Asleeve valve 21 is axially movable within the bowl between a position shown in FIG. 1 of the drawing in which its upper edge contacts thegasket 22 and seals the discharge openings Ztl and a lower position shown in FIG. 2 of the drawing in which its upper edge is in spaced relationship to thegasket 22 opening thesludge discharge openings 20.

A bottom insert member 6 defines the lower surface of the bowl interior and is spaced from the bottom 5 of the bowl casing to define a free space therebetween. The distributor 4 which extends axially upward to the central portion of the bowl is formed as an integral portion of the bottom insert member 6. This distributor distributes material introduced into the centrifuge through the conduit 19 in the bowl through the conduit 23.

The bottom insert member 6 has an outer annular guide surface 8 which acts as a sliding guide for thesleeve valve 21.

A flange 10 is connected to the lower portion of thesleeve valve 21 as an integral part thereof and moves therewith. This flange 10 extends inwardly and divides the free space between the member 6 and bottom 5 into anupper opening chamber 12 and alower closure chamber 11. The inner end of the flange terminates as a guide surface 9, which slides in contact with the hub of the centrifugal drum.

Thelower closure chamber 11 is formed as an outwardly confined storage space which is dimensioned for maintaining at least a given quantity of deformable or fiowable material such as liquid, plastic or elastic material therein at any position of movement of thesleeve valve 21 and the flange 10.

A control liquid such as water may be introduced into theupper opening chamber 12 through the conduits 16 and 17. Liquid may be removed from this chamber by centrifugal action through theoutlet conduit 13 in thesleeve valve 21 and the port 14.

In operation, the centrifugal bowl is rotated with thespindle 28 in the conventional manner. The material to be treated is introduced through the inlet pipe 19 and passes through the distributor 4 and conduit 23 into the interior of the bowl which contains the conventional disc inserts 24. The lighter liquid passes inwardly over the disc insert and is discharged over the overflow lip 25. The heavier liquid is forced by the centrifugal force outwardly and passes upward and is discharged over the overflow lip 26. Solid materials or the like, designated as sludge, accumulate at the peripheral portion 7 of the bowl interior.

Before the separator is placed in operation, a closure liquid having a high boiling point or a plastic or elastic material is introduced into theclosure chamber 11 in amount at least suflicient to fill the chamber to thelevel 15 indicated in FIG. 1 of the drawing during the centrifuging with thesleeve valve 21 in the closed position. The deformable material is forced outwardly by the centrifugal action and forces the flange 10 and thesleeve valve 21 upward in the closed position.

in order to open the sludge discharge openings, water or similar control liquid is introduced through the pipe 16 and conduit 17 into the openingchamber 12. The amount of water introduced should exceed the amount which is forced out by the centrifugal action through theopening 13 and port 14. A centrifugal head of water thus builds up in the openingchamber 12. When this head builds up so that a pressure is formed which exceeds the pressure in theclosure chamber 11, the flange 10 andsleeve valve 21 are forced downwardly to the position indicated in FIG. 2 of the drawing. The centrifugal pressure within the bowl can then force the sludge out through the annular space between the upper edge of thevalve 21 and thegasket 22 and through thedischarge openings 20. When sludge discharge has been completed, the water passing through 16 is shut oil and the water passes out of thechamber 12 through theopening 13 and port 14. The pressure caused by the centrifugal force acting on the deformable or flowable mass in thechamber 11 then forces the flange 10 andsleeve valve 21 upwardly into the closed position and maintains the same in that position until water is again introduced into the openingchamber 12.

Any excess of the deformable closure material which has been introduced into theclosure chamber 11, as, for example, upon assembly thereof may discharge through theopening 18 or 180 upon the first opening actuation ofsleeve valve 21. When theclosure chamber 12 is filled with water, it is difficult to prevent small amounts of Water from leaking out along the guide surface 9. In order to seal theclosure chamber 11 from this leakage, asmall ring chamber 29 is provided below the guide surface 9. Any water leaking through the guide surface will therefore accumulate in this ring chamber. A drain conduit 27 is provided from the ring chamber through which the water may pass out.

As theclosure chamber 11 is formed as a storage space, and is closed off to prevent entrance of control liquid from the opening chamber, the deformable mass may remain as a substantially permanent part of the apparatus within the closure chamber without subsequent additions, etc. The opening and closing are completely actuated by passing the control liquid into the opening chamber and by allowing the same to flow out therefrom.

More specifically,closure chamber 11 is provided with a widenedannular space 30, which receives a substantial portion of the deformable or fiowable mass which is displaced from the peripheral portion ofchamber 11 upon movement ofsleeve valve 21 to opened position as shown in FIG. 2. A shift in the level of said mass from that indicated at 15 in H6. 1 to that indicated at 15:: in FIG. 2 therefore takes place. Because of the location of pro jectiontube 18 in the bottom surface of bowl casing S of FIG. 1, or channel tube 180 insleeve valve 21 communicating with port 14 of P16. 2, with respect to the desired level of deformable or flowable mass disposed inclosure chamber 11, said mass will not pass out of said chamber under centrifugal action except to the limit de fined bytube 18 or 18a.

Due to the considerably decreased working surface area in the peripheral portion ofclosure chamber 11 and the comparatively insignificant increased working surface area in theannular extension space 30, upon initial movement of thesleeve valve 21 toward opened position when liquid is passed to openingchamber 12, thesleeve valve 21 will quickly move to fully opened position as shown in FIG. 2. Conversely, due to the considerably increased working surface area in the peripheral portion ofclosure chamber 11 and the comparatively insignificant decreased working surface area in theannular extension space 30, upon initial movement of thesleeve valve 21 toward closed position when liquid is no longer passed to openingchamber 12, thesleeve valve 21 will quickly move to fully closed position as shown in FIG. 1.

In operation, during rotation the level of the flowablc material is shown radially outwardly atlevel 15, the flowable material occupying the peripheral portion of the closingchamber 11 when no control liquid is passed through conduits 16 and 17 to the openingchamber 12. The level of the flowable material is determined radiullyinwardly by the presence of tube 18:: which allows excess flowable material to pass off from closingchamber 11 throughtube 18a and port 14. It will be specifically noted that the peripheral bottom surface of flange 10 and the adjacent peripheral surface of the bottom 5 of the casing together define an area of flow-able material working surface radially inwardly to thelevel 15. As may be seen from FIG. 2, when control liquid passes through conduits 16 and 17 to openingchamber 12, centrifugal action of the control liquid dammed up within openingchamber 12 due to the comparatively small flow cross-section ofoutlet conduit 13 will downwardly urge theflange 18 so as to open the ports 2!] for discharge of collected sludge in the conventional manner. The level of the flowable macrial within the closingchamber 11 will therefore be radially inwardly displaced from thelevel 15 to the level 15a. This is due to the fact that the volume of the closingchamber 11 is decreased. At this time the peripheral bottom surface of flange 10 will engage the adjacent peripheral surface of the bottom 5 whereby the area of flowable material working surface will be decreased by an extent equal to the area of abutment between said peripheral bottom surface of flange 10 and adjacent peripheral surface of bottom 5. However, due to the increased axial dimensions of theannular extension space 30 with respect to the peripheral portion of closingchamber 11, the portion of Working surface increased by the radially inward displacement of the flowable material from thelevel 15 to the level will only insignificantly compensate for the loss of working surface due to the peripheral abutting engagement of the bottom surface of flange 10 and the corresponding surface of bottom 5 of the casing. Thus, the movement of flange 10 from closing position to opening position will decrease the volume of closingchamber 11, at the same time decreasing the effective flowable material working surface area within closing chamber l1. Accordingly, since a decreased Working surface area is involved, the flange 10 will immediately respond to control liquid passed to openingchamber 12 and rapidly and abruptly open the discharge ports for the effective discharge of sludge from the drum. On the other hand, upon cessation of the feeding of control liquid to openingchamber 12, as the flange 10 moves upwardly, an effective increase in flowable material worll'ing surface area becomes available due to the parting of the abutting portions of flange 10 and bottom 5 of the casing, whereby rapid and abrupt upward movement of the flange will occur so as to closeports 20 in the desired manner. Since the force of the flowable material is greater in the peripheral portion than in theannular space 30, the abrupt movement of the flange 10 will occur with even greater effectiveness.

While the specification and accompanying drawings have been set forth for the purpose of illustration, it will be understood that various changes and modifications may be made without departing from the spirit and scope of the invention which is to be limited only by the scope of the appended claims.

We claim:

1. In a centrifugal separator having a centrifugal bowl with peripheral sludge discharge openings and an axially movable sleeve valve, movable between a position opening and a position closing said sludge discharge openings, the improvement which comprises an insert member defining an end surface of the bowl interior and positioned to define a free space between it and the adjacent wall portion of the how], a flange connected to said sleeve valve for movement therewith extending inwardly within said free space dividing the same into an opening chamber and a closure chamber, means for introducing liquid into said opening chamber during centrifugal operation to move said sleeve valve to opening position and means for the removal of liquid from said opening chamber, said closure chamber containing flowable material therewithin and having means for sealing said closure chamber against the flow and overflow of said material therefrom into said opening chamber and for sealing said closure chamber against the complete outward flow of said material therefrom both at standstill and under centrifugal action whereby a given mass of a flowable closure material will be maintained therein both at standstill and during operation and in any position of movement of said sleeve valve for closing actuation of said sleeve valve, said closure chamber defining between the flange and the adjacent wall portion of the bowl an outwardly confined storage space having, when said sleeve valve is in closing position, a radially wide and axially narrow dimensioned peripheral zone completely occupied by said flowable material during centrifugal operation and a radially narrow and axially wide dimensioned annular zone inwardly with respect to said peripheral zone only partially occupied by said flowable material during centrifugal operation, whereas when said sleeve valve moves to opening position, both the radially wide and axially narrow dimensions of said peripheral zone substantially decrease and the flow-able material therein is forced therefrom into said annular Zone while the axially wide dimension of said annular zone only slightly decreases and the radially narrow dimension of said annular zone remains substantially constant.

2. Improvement according to claim 1 wherein said flowable material is a plastic material.

3. Improvement according to claim 1 wherein said flowable material is an elastic material.

4. Improvement according to claim 3 wherein said elastic material is rubber.

5. In a centrifugal separator having a centrifugal bowl with peripheral sludge discharge openings and an axially movable sleeve valve, movable between a position opening and a position closing said sludge discharge openings,

the improvement which comprises an insert member defining an end surface of the bowl interior and positioned to define a free space between it and the adjacent wall portion of the bowl, a flange connected to said sleeve valve for movement therewith extending inwardly within said free space dividing the same into an upper opening chamber and a lower closure chamber, said closure chami361 defining by means of said flange and the bowl an outwardly confined adjustable volume storage space dimensioned thereby for the maintaining of a predetermined quantity of flowable material therein undzr centrifugal action and at standstill in any position of movement of said sleeve valve and in turn said flange, said flange substantially completely sealing said closure chamber from flow communication with said opening chamber, an elastic flowable material positioned in said closure chamber and means for introducing liquid into said opening chamber during centrifugal operation to move said sleeve valve to opening position and means for the removal of liquid from said opening chamber, said adjustable volume storage space having, when said sleeve valve is in closing position, a radially wide and axially narrow dimensioned peripheral zone completely occupied by said flowable material during centrifugal operation and a radially narrow and axially wide dimensioned annular zone inwardly disposed with respect to said peripheral zone only partially occupied by said flowable material during centrifugal operation, whereas when said sleeve valve moves to opening position, both the radially wide and axially narrow dimensions of said peripheral zone substantially decrease and the flou /able material therein in forced therefrom into aid annular zone while the axially wide dimension of said annular zone only slightly decreases and the radially narrow dimension of said annular zone remains substantially constant.

6. In a centrifugal separator having a centrifugal bowl with peripheral sludge discharge openings and an axially movable sleeve valve, movable between a position opening and a position closing said sludge discharge openings, the improvement which comprises an insert member defining an end surface of the bowl interior and positioned to define a free space between it and the adjacent wall portion of the bowl, a flange connected to said sleeve valve for movement therewith extending inwardly within said free space dividing the same into an opening chamber and a closure chamber, said closure chamber defining by means of said flange and the bowl an outwardly confined storage space adjustable in volume in dependence upon the movement of said flange, containing a flowable material therewithin and being peripherally and annularly dimensioned thereby for permanently maintaining at least a predetermined amount of said flowable material therein under centrifugal action and at standstill in any position of movement of said sleeve valve and in turn said flange, said flange substantially completely sealing said closure chamber from flow communication with said opening chamber and defining with the bowl interior a closure chamber radially outward annular peripheral portion having a substantially decreased flowable material working surface area in opening position of movement of said flange with said sleeve valve and a substantially increased flowable material working surface area in closing position of movement of said flange, said flange further defining with said bowl interior a closure chamber radially inward annular axial portion having a slightly increased flowable material working surface area in opening position of movement of said flange with said sleeve valve and a slightly decreased flowable material working surface area in closing position of movement of said flange, and means for introducing liquid into and for the removal of liquid from said open chamber, whereby upon actuation of said sleeve valve to opened position by introducing liquid into said opening chamber, the working surface area of said flowable material against said flange at the peripheral portion of said closure chamber will substantially decrease and the working surface area of said flowable material against said flange at the annular portion of said closure chamber will only slightly increase, while upon actuation of said sleeve valve to closed position by the removal of liquid from said opening chamber, the working surface area of said material against said flange at said peripheral portion will substantially increase and the working surface area of said material against said flange at said annular portion will only slightly decrease, enabling said sleeve valve to move rapidly to both the opened and closed positions without increasing and decreasing the amount of flowable material within said closed chamber upon such actuation.

7. Improvement according to claim 1 wherein an opening communicating with the exterior of said separator is provided in the upwardly limiting wall of the closure chamber a predetermined radial distance from the periphery of said closure chamber and axially above a predetermined level of said flowable material in said closure chamber when said separator is at standstill, whereby complete outward fiow of said fiowable closure material will be prevented and a given mass of said material will be maintained therein in any said position of movement of said sleeve valve.

8. Improvement according to claim 1 wherein a tubular extension communicating with the exterior of said separator projects a predetermined distance into said closure chamber a predetermined distance from the periphery of said closure chamber and axially above a predetermined level of said fiowable material in said closure chamber when said separator is at standstill, whereby complete outward fiow of said fiowable closure material will be prevented and a given mass of said material will be maintained therein in any said position of movement of said sleeve valve.

9. Improvement according to claim 6 wherein an opening communicating with the exterior of said separator is provided in the upwardly limiting flange wall of the closure chamber a predetermined radial distance from the periphery of said closure chamber and axially above a predetermined level of said fiowable material in said closure chamber when said separator is at standstill, whereby complete outward flow of said fiowable closure material will be prevented and a given mass of said material will be maintained therein in any said position of movement of said sleeve valve.

10. Improvement according to claim 6 wherein a tubular extension communicating with the exterior of said separator projects a predetermined distance into said closure chamber a predetermined distance from the periphery of said closure chamber and axially above a predetermined level of said fiowable material in said closure chamber when said separator is at standstill, whereby complete outward flow 0t said flowable closure material will be prevented and a given mass of said material will be maintained therein in any said position of movement of said sleeve valve.

References Cited in the tile of this patent UNITED STATES PATENTS 878,591 Sonnenfeld et al. Apr. 18, 1905 957,347 Kennedy May 10, 1910 2,103,822 Perry Dec. 28, 1937 FOREIGN PATENTS 122,937 Sweden Oct. 5, 1948 616,442 Great Britain Jan. 21, 1949

Claims (1)

1. IN A CENTRIFUGAL SEPARATOR HAVING A CENTRIFUGAL BOWL WITH PERIPHERAL SLUDGE DISCHARGE OPENINGS AND AN AXIALLY MOVABLE SLEEVE VALVE, MOVABLE BETWEEN A POSITION OPENING AND A POSITION CLOSING SAID SLUDGE DISCHARGE OPENINGS, THE IMPROVEMENT WHICH COMPRISES AN INSERT MEMBER DEFINING AN END SURFACE OF THE BOWL INTERIOR AND POSITIONED TO DEFINE A FREE SPACE BETWEEN IT AND THE ADJACENT WALL PORTION OF THE BOWL, A FLANGE CONNECTED TO SAID SLEEVE VALVE FOR MOVEMENT THEREWITH EXTENDING INWARDLY WITHIN SAID FREE SPACE DIVIDING THE SAME INTO AN OPENING CHAMBER AND A CLOSURE CHAMBER, MEANS FOR INTRODUCING LIQUID INTO SAID OPENING CHAMBER DURING CENTRIFUGAL OPERATION TO MOVE SAID SLEEVE VALVE TO OPENING POSITION AND MEANS FOR THE REMOVAL OF LIQUID FROM SAID OPENING CHAMBER, SAID CLOSURE CHAMBER CONTAINING FLOWABLE MATERIAL THEREWITHIN AND HAVING MEANS FOR SEALING SAID CLOSURE CHAMBER AGAINST THE FLOW AND OVERFLOW OF SAID MATERIAL THEREFROM INTO SAID OPENING CHAMBER AND FOR SEALING SAID CLOSURE CHAMBER AGAINST THE COMPLETE OUTWARD FLOW OF SAID MATERIAL THEREFROM BOTH AT STANDSTILL AND UNDER CENTRIFUGAL ACTION WHEREBY A GIVEN MASS OF A FLOWABLE CLOSURE MATERIAL WILL BE MAINTAINED THEREIN BOTH AT STANDSTILL AND DURING OPERATION AND IN ANY POSITION OF MOVEMENT OF SAID SLEEVE VALVE FOR CLOSING ACTUATION OF SAID SLEEVE VALVE, SAID CLOSURE CHAMBER DEFINING BETWEEN THE FLANGE AND THE ADJACENT WALL PORTION OF THE BOWL AN OUTWARDLY CONFINED STORAGE SPACE HAVING, WHEN SAID SLEEVE VALVE IS IN CLOSING POSITION, A RADIALLY WIDE AND AXIALLY NARROW DIMENSIONED PERIPHERAL ZONE COMPLETELY OCCUPIED BY SAID FLOWABLE MATERIAL DURING CENTRIFUGAL OPERATION

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