US2862659A - Centrifugal separator - Google Patents

Description

Dec. 2, 195s AgNYRoP CENTRIFUGAL SEPARATOR Filed May '51,1956 -f :JMW AAG@ NY/Po'P -un... .N u A n... v

United States at 2,862,659 Patented Dec. 2, 1958 2,862,659 CENTRIFUGAL SEPARTOR Aage Nyrop, Heilerup, Denmark Application May 31, 1956, Serial. No. S18-8,493 4 Claims. (C1. 23o- 20) The present invention relates to improvements in centrifugal separators designed to separate sludge from liquids and discharge such sludge through slots aty the periphery v of the centrifugal bowl. The invention relates more particularly to a device for feeding and purifying an actuating liquid used to effect the closing and opening of such slots by means of an annular member. The term sludge as used herein is to be considered as designating not only impurities in liquids, but any materials including a large proportion of solids of higher specific gravity. than the liquids in which they are suspended.

The improved separator is of the type of centrifugal separators in which the centrifugal bowl is mounted for rotation on a vertical axis to effect continuous discharge of liquid efliuents and provided withperipherially placed sludge discharge openings for the evacuation of suspended solid material concentrated and collected within the bowl. A suitable shaped sealing piston for controlling the sludge discharge through said openings is mounted for axial reciprocation within the bowl. Said piston is actuated for intermittent displacement partly by pressure of the treated liquid in the bowl and partly by means of an actuating liquid, influencedby centrifugal force, and introduced into a spaced below the said piston through channels from a chamber with annular grooves in the body of the bowl. The actuating liquid is introduced into one of the grooves to cause the closing of the bowl slots, and introduced into the other groove to cause the opening of a valve, as later described.

The actuating liquid introduced'into said space below the piston is checked by means-of hydrostatic meansl 1ncluding avalve device with the result that theactuating liquid is either retained or discharged, thereby causing displacement ofthe said piston to either close ory open the sludge discharging openings in the'bowl.

Frequently the actuating liquid is discharged from the separator as waste. In some cases water is used as' the actuating liquid, but in cases where water is scarce, or it is found advantageous to use other liquids such as oil or'apart of the liquid discharged from the separator, it is important that-such liquids be cleanand unpolluted. In some cases it is desirable to repeatedlyuse the same actuating liquid but during thecycle of passing through the bowl andback to the reentering meansthe'liquidbe/ comes polluted. Such a p'ollutionwill result in difliculties with the control'ofthe valves and Withthedisplacement ofthe piston. A constant purication of' the" actuating liquid is*` consequently important.

Themain obiectofl the invention is to' provide av centrifugal separator ofthe type mention'edf with special means forV conveying 'the actuating liquid tolthe separator and purifying this liquid before it'isfp'ut" to! usel as: the actuating liquid; The: improved' centrifugab separator hasfor this purpose'an annularreservoiradapted to receive 'the actuating liquid audretain itfor puricationun dertheraction of centrifugal-force. Further, the-separator has means toconduct'this liquidit'o' the reservoit and sta-- bilize its level therein. It also has means to4 selectively conduct the liquid from said reservoir to'either of the said annular grooves: Y

Further features of the invention will be apparent from the following detailedV description in connection with., the accompanying drawing, in which Fig. l-is acentral"axial-sectional View' of a separator bowl provided with a reservoir and feeding devices according to the invention;

Fig. 2 is a detail sectional View similar to a portion of Fig. l, of a modified form of the invention, andl showing a special combined device for both feeding the liquid to the reservoir and selectively conductingvthe puried liquid in the reservoir to the annular grooves;

Fig. 3 is a detail horizontal sectional View of thel feeding device in Fig. 2 taken on the line III-#Ill in Fig. 2, and

Fig. 4 is an enlarged detail section showing the ejectn ing valve means.

Referring more in detail tothe drawing, the separator bowl is divided into two coaxial-parts, namely, a lower' part 1 and an upper part 2, which'parts in known manner are interconnected by means of a threadedring or flange 3 integral with part 2 or byan equivalent connection'.

' The separator bowl isrnounted on a shaft 4- that may be rotated at a high speed inra known manner by meansy of transmission members not shown in the drawing. The

separator is providedv with a feeding tube 5 for feeding the material to be separated into the centrifugal bowl. In the latterl is a distribution tube 6l forfthe distribution of the material to the interi-or of the bowl. The distributing tube 6 carries a'suitable stack of discs 8. The bowl is further provided with-a skimming plate 9 by which itis possible tol separate two liquid components of different gravitiesanda sludge component. The two liquid components may be discharged through discharge openings liti and 11 into receptacles-12 and 1.3 respectively, or through known impeller devices, not included in the drawing; The sludge collected'inv space 7 may be discharged:

through discharge openings or slots 14 in the circumferential wall of the bowl.

These openings 14am-sealed or' unsealedby means of an annular piston 15"mo.unted for reciprocal movement within anannular groovein the lowerV part of the bowl. They piston 15'has a'llange- 17 projecting into a space which', by means'of the! flange, is divided into two cornmunicating chambers 18'and'19above and below said flange respectively. In` closed-bowl slot' condition the piston 15 isheldv in" sealing position by being pressed against a gasket 16 in the'upper part 2`of= the bowl by means of an actuatingv liquid' inllencedl by centrifugal force andlintroduced in the'spaces or chambers 18` and 19; ThefpistonlS is displaced to open the/slots 14' partly by pressure of'thefliquid treated in the bowl andpartly by means of anactuating liquid retained in thev spaceV 18 when'the liquidfin' the space 19 is ejected'by opening one or more ejecting'valvemeans 20 to permit of the escape' of the liquid'through channels' 21'and 22. The Valve member or device 20, which cany be of any suitable type, is'held in closed position by4 means of 'centrifugal force; The lower part 1 of the bowl has initsbody an annular chamber 23 divided 'by aninwardly projecting flange into two grooves 24'an'd25. The lower' groove 24is`conl nected by a channel 26' with the spaces 18"and"19"a'ndv serves to receive actuating liquid for the displacement' off the pistonlS" to its closed' orV sealing position. The upperl groove 25'is connected by`a'chan'nel 27 with" a space at the'valve means20 This chanr1e1'27 serves to-conductv anfactuatingliquid to the valve meansfor its displacementto open position, thereby permittingl of the discharge of the actuating liquid from-thesspace 19 and resulting' in the simultaneous displacementof` voir 28, which is coaxial with and communica-tes" withv the chamber 23fand hence itsgroovesf2-4vand25-.- Thisv much larger chamber or reservoir 28 isfadapted t'ofrey ceive and'hcld the actuating liquid for its purification by the action of centrifugal force. The impurities will deposit at the circumferential wall of the reservoir 28 and are removed whenever necessary. It is advantageous to provide inwardly extending ribs or Wings 28a in the outer Zone of the reservoir 28 to bring the liquid to the same speed of rotation as the bowl. Because of centrifugal action the actuating liquid conveyed to the spaces 18, 19 and 2li will be in a pure condition. The actuating liquid is conveyed to the reservoir 28 by means of an upright tubular member 29 provided at its top with a laterally turned end forming a paring or skimming device 29a. The member 29 is rotatably'mounted in the separator frame 36 and can be turned round its vertical axis by means of a handle 30 iixed to it and moving in a slot in the frame. Thus it is possible to place the skimming member 29a in a predetermined position so that the level of the liquid in the reservoir may be kept constant. The liquid is conveyed to the reservoir under a suitable pressure and when the surface of the liquid in the reservoir reaches the skimming member 29a, the feed will be i checked by the hydrostatic counter pressure generated in the skimming member when touching the liquid. In this manner it is possible automatically to maintain a predetermined level of the liquid in the reservoir 28.

The actuating liquid is conveyed from the reservoir 28 to the annular grooves 24 and 25 by means of a conveying device. This device is mounted for vertical movement in the separator frame 36 and consists of a vertical spindle 31 with a paring or skimming device at its upper end disposed in the reservoir. The spindle is mounted to reciprocate and the skimming and feeding device comprises a tubular element 33 fixed between its ends to the top of the spindle and having an open inlet end 32 and an upwardly turned discharge end 33 terminating in an open outwardly directed extremity 34. The inlet end extends radially outward and the upright discharge end 34 is of such height that by vertically adjusting the spindle the extremity 34 may be positioned to direct the liquid into either of the grooves 24 or 25. During the rotation of the bowl the skimming end 32 will skim the liquid from the surface of the body of liquid in the reservoir and convey it either to the groove 24 or to the groove 25. When the outlet 34 is placed to feed into thegroove 24, the actuating liquid will from this groove be conveyed through the lchannel 26 to the spaces 18, 19 and consequently force the piston to its bowl closing position. When the outlet 34 is moved to feed into groove 25, the actuating liquid will from this groove be conveyed through the channel 27 to a space at the Valve member and force this valve member into open position with the result, that the actuating liquid in the space 19 below the flange 17 will be discharged from the passage 22. The hydrostatic pressure of the treated liquid in the interior 7 of the bowl and in the liquid4 in the space 18 above the iiange 17 will force the piston 15 downward and thereby open the sludge discharge slots 14. The device with the member 31, 32, 33 and 34 may be moved to action either mechanically or manually as by means of a handle 35, which is jointed to the spindle 31 and is able to turn around an axis 37 in the separator A frame 36. The handle 35 can be locked in a known manner.

To simplify the construction the liquid feed to the reservoir and the selective discharge of liquid from the latter to the grooves may be combined as shown in Figs. 2 and 3. In such a construction the spindle has a bore 38 in its upper part, which can guide liquid from an inlet 3'9 to the skimming element 29a. The means for conducting liquid from the reservoir to the grooves may -be mounted on one side of the member 29a as seen in Fig. 3. The annular grooves 24 and 25 are coaxial with the reservoir 28 and their dams have such'a diameter that a surplus of liquid from the grooves 24 and 25 will stream back to the reservoir 28, thereby avoiding loss of liquid. With a special construction the groove 25 may be provided with 4 overow tubes 41 by which the level of the liquid in the groove is checked.

To collect the actuating liquid, which is discharged from the space 19 through the valve means 29, the centrifugal bowl is surrounded with a receptacle 42 carried lby the frame 36. The receptacle 42 has a discharge tube 43, which in certain cases may be connected with the feed pipe or member 29 through a suitable pumping means so that the discharged actuating liquid may be conveyed back to the reservoir 28. Surrounding the receptacle 42 there is a wall 44 to form a compartment 45 to collect the sludge which is discharged from the interior "l ofthe centrifugal vbowl through the slots 14. in the space between the wall of the receptacle 42 and the exterior of the centrifugal bowl there are arranged annular rib-like members 46 to prevent sludge from entering the receptacle 42.

The feeding tube 6 is provided with a thermometer 47 to show the temperature of the liquid supplied through a tube 48 to the feed tube 6. A iiow control meter 5i) may be in the feed tube 48.

The part of the separator forming the receptacles 12 and 13 is hingedly connected with the frame by a hinge 49.

i declare that what I claim is:

l. In a centrifugal separator, the combination of a centrifugal bowl mounted for rotation on a vertical axis to etfect continuous discharge of liquid etuents and provided with peripheral sludge discharge openings for suspended solid material collected within the bowl, a sealing piston for controlling the sludge discharge through said openings and mounted for axial reciprocation within the bowl, said piston being actuated to intermittent displacement partly by pressure of the treated liquid and partly by means of an actuating liquid influenced by centrifugal force land conducted by means of ya channel from an annular groove in the body of the ybowl to a space below said piston, said space being connected with a discharge arrangement for the actuating liquid, this discharge ar-.

rangement comprising a valve means and hydrostatic means for displacement of the valve means to an open position to permit the discharge of the a-ctuating liquid and the simultaneous resulting movement of said piston to its open sludge-discharging position, said hydrostatic means in the body of the said bowl comprising a second annular groove for intermittent reception of actuating liquid and communicating with said valve means, an annular reservoir adapted to receive and hold the actuating liquid for purification by centrifugal force, means to conduct actuating liquid to said reservoir and means to conduct actuating liquid from said reservoir to either of said annular grooves to cause the actions described.

2. In the structure of a centrifugal separator as described in claim l in which said annular grooves in the body of the bowl have means to conduct surplus of actuating liquid back to said reservoir.

3. In the structure of a centrifugal separator as described in claim 1 in which said means to conduct actuating liquid from said reservoir to said annular grooves comprises a reciprocating device which can conduct the actuating liquid alternately from said reservoir to either of said grooves to effect opening or closing the sludge discharge openings in the bowl.

4. In the structure of a centrifugal separator as described in claim 1 in which said means for conducting actuating liquid to said reservoir includes an adjustable device capable of adjusting the surface level of the actuating liquid in the reservoir to a predetermined level.

References Cited in the file of this patent UNITED STATES PATENTS 2,091,329 Nyrop Aug. 31, 1937 2,551,041 Nielsen May 1, 1951 2,578,484 Nyrop Dec. 11, 1951

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