CA1042363A - Cyclone centrifuge apparatus - Google Patents

Abstract

CYCLONE CENTRIFUGE APPARATUS
Abstract of the Disclosure:
Cyclone centrifuge apparatus of the stationary or rotating types having a new and improved means for admitting the feed thereto for reducing turbulence and cross-flow at the entry, decreasing the input pressure required for a given rate of feed throughout, and reducing the expenditure of hydraulic energy required for achieving a desired separa-tion or obtaining improved separation of the light and heavy phases of the feed for a given expenditure of hydraulic energy.

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Description

~04Z363 Background of the Invention:
The field of this invention is cyclone centrifuge apparatus.
In the past, it has been conventional for the feed having at least two components of different densities, to be fed tangentially or at an angle at the inlet to the sepa-rating chamber. See, for example, the Applicant's own U. S.
Patent No. 3,648,840, the art cited therein, and an article entitled "Fl~w Pattern and Pressure Drop in Cyclone Dust Collectors" by C. B. Shepherd and C. E. Lapple in "Industrial ~ and Engineering Chemistry", Vol. 32, No. 9, pages 1246-1248.- Additional art known to the Applicant likewise showingangular or tangential feed inlets include U. S. Patents Nos.

2,526,627; 2,560,069; 3,306,461; 3,285,422; 3,350,852; and ,507,397.
With such prior art, the inlet feed stream was ! ~ actually cutting across the main flow stream and generally,- the inlet pressure had to overcome the pressure at the outer periphery of the-separating chamber, which was the point at which the pressure is the greatest.
Summary of the Invention:
~ The present invention relates to new and improved cyclone centrifuges wherein the inlet feed stream is Lntro-duced into a static flow chamber upstream of a substantially - radially extending choke and then into a separating chamber, whereby the inlet stream may enter the static flow chamber at a reduced pressure as compared to that re~uired for the same flow when the feed is directly into the separating chamber through a choke, whereby the efficiency of the apparatus is increased.

~04Z363 Additionally, in the rotating cyclone centrifuge, the discharge of the separated phases is controlled to con-trol within limits the extent of the separation of the heavy phase from the light phase, and to increase the effectiveness of such separation.
Brief Description of the Drawings:
Fig. 1 is a sectional view of a stationary conical shaped cyclone centrifuge incorporating the structure of this invention;
~ 10 Fig. 2 is a sectional view taken on line 2-2 of ; Fig. l; -Fig. 3 is an isometric view of the choke assembly ` incorporated in the centrifuge apparatus of Fig. l;
Fig. 4 is a sectional view of a modified form of the invention wherein the centrifuge is substantially cylin-~7~ : drical and the choke assembly is modified so that it has a ,~
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plurality of vanes rather than the single vane of Figs. 1-3;

Fig. 5 is a sectional view taken on line 5-5 of - Fig. 4;

Fig. 6 is an isometric view illustrating the modi-fied choke assembly incorporated in the apparatus of Fig. 4;

Figs. 7 and 8 are two views, showing the inlet and ;~ the outlet portions, respectively, of a rotatable cyclone ~ centrifuge having the choke assembly of Fig. 6 therewith;
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Fig. 9 is a sectional view taken on line 9-9 of Fig. 8 and illustrating only the central flow control element ~ ` at the discharge end of the centrifuge apparatus of Figs. 7 - and 8;

Fig. 10 is an end view of the control element of Fig. 9, looklng at it from line 10-10 of Fig. 9~ and ~ .

1~)4~363 Fig. 11 is a sectional view taken on line 11-11 of Fig. 9 to show further details of such control element.
Description of the Preferred Embodiment:
In the drawings, the letter A designates generally a conical cyclone centrifuge having therewith the structure of the present invention. Broadly, the centrifuge apparatus A includes a body or h~using 10 having a separating chamber lOb, lOa formed therein. An inlet 12 to the separating chamber lOb, lOa is provided for the feeding of a liquid or fluid having components of different densities to be separated ~- into at least two phases. A first outlet 14 is also provided ~ from the separating chamber lOb, lOa for the lighter phase `~ which ïs separated from the feed fluid. A second outlet 16is provided from the separating chamber lOb, lOa for the discharge of the heavier phase of the material which is ~:,1. .
separated from the feed introduced at the inlet 12, as will be more fully explained. With the present invention, a choke assembly C is provided between the inlet 12 and the separatlng chamber lOb, lOa, as will be more fully explained, which assembly C provides for reduced turbulence and cross-flow at the entry of the feed fluid, a decrease in the input pressure required for a given rate of through-put of the feed fluid, either a reduced hydraulic energy expenditure for achieving tha de-sired separation into the several phases, or an improved separation for the same expenditure of hydrau-lic energy.
Considering the apparatus of Figs. 1-3 more in de-tail, the choke assembly C which i9 preferably used in the apparatus A includes a single helically disposed vane 20 which extends for slightly more than a full revolution or 104Z;~63 slightly more than 360 so that its substantially radially extending ends 20a and 20b overlap each other and are longi-tudinally spaced from each other a predetermined amount to provide a choke or orifice opening 21 therebetween.
As illustrated in Fig. 1, the first outlet 14 is provided by a vortex finder or outlet tube 25 which is threaded at 25a or is otherwise secured in a retainer cap or closure 26 mounted at the upper end of the housing 10 by any suitable means such as retaining bolts 27. The vortex finder 25 extends centrally within the housing 10 in its upper substantially cylindrical portion lOb. The vane 20 is welded or is otherwise affixed at its inner diameter 20c to the external surface of the tube 25. The outer periphery 20d of the vane 20 is welded or otherwise secured to a ring . ~i . . 28, or directly to the housing 10. The ring 28 is sealed or otherwise mounted within the housing 10 as illustrated in Figs. 1 and 2.
The choke assembly C is disposed below the substan- ' tially radial inlet 12 so that a static flow chamber 30 is 20 -~ formed in the housing 10 between the choke assembly C and the inlet 12. As can best be seen in ~ig. 2, the inlet 12 s disposed with its central axis in alignment with the longitudinal central axis of the housing 10 and the finder - tube 25 and it is disposed substantially radially with - respect to the circular cross-section of the static flow chamber 30.
In Fig. 3, a removable choke member 31 is illus-trated as mounted on the lower portion of the vane 20 so that the leading edge 31a thereof is substantially aligned with the substantially radially extending edge 20b of the "' vane 20. The choke element 31 may be releasably attached to the vane 20 by screws 32 or othèr suitable attaching means.
For purposes of illustration, the choke element 31 has been omitted from Figs. 1 and 2, but it will be understood that such choke element 31 may also be incorporated in the appara-tus as illustrated in Figs. 1 and 2. The choke element 31 merely provides for an adjustment in the size of the choke or orifice opening 21 between the overlapping ends of the vane 20 to provide for different operating conditions with ... . .
respect to the fluid feed and the desired separation thereof, ~; as will be well understood by those skilled in the art.

In the operation or use of the form of the invention illustrated in Figs. 1-3, the fluid which is introduced at .
- the inlet 12 may be a liquid or gas having solids therewith of different densities which are to be separated from each .
other, or a single solid which is to be separated from the liquid. It will be appreciated that various degrees of separation or classification may be effected, depending upon the flow conditions and other factors known to those skilled in the art.
With the present invention, the chamber 30 is es-~ - .
sentially a static flow area in which the fluid in the form of liquid or gas with the solids therewith, if present, is forced to pass through the choke or orifice opening 21. The fluid loses pressure and gains greatly in velocity as it passes across the choke 21 into the separation chamber therebelow, forming the conventional free votex within the cyclone. Turbulence is minimized because there is substan-tially no interference or cross-flow of the fluid as it passes from the choke into the separation chamber lOb, lOa, ~04Z363 which results from the fluid emerging from the chamber 30 through the choke 21 at substantially the same velocity and the same direction as the fluid flowing in the separation chamber lOb, lOa. The pressure drop across the orifice 21 increases from the outer diameter of the vane 20 to the inner diameter thereof. Thus, because the fluid in the chamber 30 is essentially static or at low velocity prior to passing through the choke 21, the inlet 12 may be disposed ^ substantially radially as shown in Fig. 2 or at any other ~ angle without creating turbulence or cutting across lines of flow of the fluid flowing in the free vortex within the separating chamber beyond the orifice 21.
The heavier phase of the fluid will be thrown to the outer peripheral area and is discharged at the second outlet 16 whlle the lighter phase is discharged through the vortex finder 25 and outlet 14. Because of the reduction in turbulence and the cross-flow which has been present in the prior art, a smaller amount of energy is required for intro-. :. :
ducing the inlet feed for a given throughput of the fluid than is required in the prior art. Alternatively, with the same energy input for the inlet feed, a greater throughput :, of the feed through the apparatus A and therefore a more ef-fective separation is accomplished.
Referring now to the form of the invention illus-trated in Figs. 4-6, the centrifuge apparatus A-l has a cylindrical housing 110 and a cylindrical inner bore in the separating chamber llOa throughout the full length thereof.
The inlet 112 is aligned substantially centrally along the ~ axis of the housing 110 so as to direct the inlet fluid to a `

- 30 modified choke assembly C-l. The inlet 112 is secured to '~

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~042363 the housing 110 by a plurality of bolts 127 or other suitable securing means which extend through an annular 1ange 126 which is preferably integral with the inlet tube 112.
The choke assembly C-l includes a pair of vanes 120, each of which has overlapping ends 120a and 120b.
Thus, each of the vanes 120 extends for a distance slightly ; greater than 180 so that there is an overlapping of the ends 120a and 120b, with a longitudinal space between such overlapping ends as best seen in Figs. 4 and 6. The space between the overlapping ends 120a and 120b provides a pair of diametrically disposed chokes 121 through which the ~ ~ incoming fluid must pass prior to entering the separating ; - ~ chamber l~Oa. A central cylindrical plug 125 is preferably provided with the vanes 120 and to which the inner edges - 120c are welded or are otherwise secured. In the event themodified choke assembly C-l is utilized in the arrangement of Figs. 1-3, the central plug 125 would preferably be a vortex finder corresponding to the tube 25 rather than being the solid plug 125. Also, in the event the inlet 112 is disposed radially rather than axially, the inlet would -preferably be at approximately the mid point at each of the - vanes 120 so as to be 90 from each of the orifices 121.
~ The outer peripheral edge 120d af each of the ; ~ vanes 120 is welded or is otherwise secùred to a mounting ;~ sleeve 128 which is suitably mounted in the housing or body 110 as best seen in Fig. 4. However, the outer peripheral edges 120d may be directly connected to the inside of the housing 110 so that the sleeve 128 is eliminated. The removable and adjustable choke element 31 shown in Fig. 3 of the drawings may be incorporated with each of the chokes 121 : ~042363 in the same manner as illustrated in Fig. 3, but for simpli-city of illustration, the choke element 31 hàs not been in-cluded with the vanes in the choke assembly C-l. Also, as ` previously noted, the choke assembly C-l may be utilized ; with the apparatus A and conversely, the choke assembly C
:;~ may be utilized with the apparatus A-l :: .
The discharge of the separated or classified components of the fluid occurs at the same end in the appara- ~:
tus A-1, which is opposite from the inlet end 112. Thus, the heavier phase is directed radially outwardly through one ~- or more discharge openings 116 in the housing or body 110 : while the lighter phase is discharged through a central opening 114 which may have a removable sleeve 114a therein which is suitably mounted and sealed.
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~ : The operation or use of the apparatus A-l is .
essentially heretofore described in connection with the apparatus A. A static flow chamber 130 is created between the inlet 112 and the choke assembly C-l so that the feed fluid develops a pressure area with substantially no velocity . ~ ~
: 20 : in the chamber 130 upstream of the chokes 121. The pressure drop across the chokes 121 is controlled by the size of the openings between the overlapping ends 120a and 120b and such size may be adjusted by an additional choke element such as : the.choke element 31, as previously explained. The pressure drop across each of such chokes 121 gradually increases in a -i ~ direction from the outer periphery of the vanes 120 towards . . . .
the inner diameter at the plug 125. The free vortex flow occurs within the separating chamber llOa so that the heavier phase i8 discharged through one or more discharge openings :
:' 116 while the lighter phase exits through the central opening 114.
In Figs. 7-11, a further modification of the appa-ratus of this invention is illustrated, wherein the apparatus is generally designated A-2. The apparatus A-2 has a body 210 which is mounted for rotation to create a rotating cyclone centrifuge, the details for the rotation of which are illustrated in U. S. Patent No. 3,648,840.
Thus, the housing 210 is connected to an inlet tube 212 by bolts 227 or other suitable securing means which extend through a flange-226 which is preferably integral . ~ .
~ with the tube 212. The upper end of the tube 212 is mounted :: :
in a suitable bearing 50 which is supported on a `fixed foundation for support 51, a portion of which is lllustrated in Figs. 7 and 8. The upper end of the inle* tube 212 extends into a seal-swivel 52 which is likewise secured to the plate 51 by bolts 52a having nuts 52b therewith, or any other suitable securing means. An inlet pipe 53 which does not rotate is mounted with the swivel 52 so that the fluid flows through the swivel 52 from the pipe 53 into the inlet tube 212 while the tube 212 is rotating relative to the fixed inlet pipe 53, the mounting of which may be identical to that illustrated in said U. S. Patent No. 3,648,8~0 and , .;
the details of which form no part of this invention.
- Power for rotating the apparatus A-2 is preferably - obtained by any suitable means such as drive belts which are - connected to a multiple belt pulley 55 which is connected to the external surface of the inlet tube 212.
It should al80 be noted that the housing 210 has a discharge control element 60 at its lower end which is _g_ ~ ,. , _ , _ ~04Z363 secured to the lower end of the body 210 by bolts 61 or other suitable connecting means. The details of the control element 60 will be described hereinafter,, but it is desirable to mount the lower end of such control element 60 in a lower - bearing 65 of any suitable construction which is supported on the support plate or foundation Sl.
The apparatus A-2 is illustrated with the choke assembly C-l which has been heretofo~e described in connec-tion with Figs. 4-6,' although as previously pointed out, the ~ ~ 10 choke assembly C of Figs. 1-3 may be substituted for the -~' assembly C-l in the housing 210. The choke assembly, whether . ~ . I
C or C-l is disposed so that all of the fluid inlet from the inlet tube 212 which enters a static flow chamber 230 must flow through the orifices 121 into the separating chamber - 210a in the housing or body 210.
~,~ The discharge control element 60 is formed with a pair of discharge openings or passages 216 so that the heav-ier phase which is separated in the separating chamber 210a ;~
discharges through such openings or passages 216 to a common central outlet which is preferably formed by a removable in-sert sleeve 66 mounted with suitable securing means such as ~ bolts 66a. In Fig. 9, the lower discharge end 216b is shown : as it exits from one of the passages 216, and in Fig. 9, the removable insert 66 is omitted so that the bore 60a of the - ~ control element 60 is more clearly seen than in Fig. 8, The insert sleeve 66 has a bore 66b through which the heavy phase flows to discharge. The inlet end 216a of each of the ~- openings 216 i8 disposed near the outer peripheral area of the separating chamber 210 near the lower end thereof.
Although the invention i8 illustrated with two such passages ~ . , . _ _ 216, more or less of such passages 216 may be provided.
A central opening 214`which is axially aligned with the central axis of the separating chamber 210a is provided in the control element 60 and it communicates with laterally extending openings 214a, which are preferably at 90 to the main opening 214. For controlling the amount of the lighter phase which is discharged through the first outlet opening 214 and its lateral openings 214a therewith, a removable and replaceable insert 70 is mounted in the . ~. , .
10 ~ opening 214 with suitable securing means such as bolts 70a.
-~ The size of the bore 70b contributes to the determination of the amount of the light phase of the separated fluid which passes out through the openings 214a.
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In the operation or use of the apparatus A-2, the fluid having the components to be separated is introduced through the fixed pipe 53 into the rotating inlet tube 212 - -so as to develop a pressure in the chamber 230 of relatively static fluid which flows through the orifices 121 in accor-dance with the pressure and pressure drop conditions created by such orifices 121 and the inlet pressure. The free vortex is developed together with the forced vortex due to - the rotation of the body 210. Because the discharge open-ings 214a are disposed laterally with respect to the opening 214, there is a pumping action created due to the rotational movement of the control member 60, thereby increasing the ,~
velocity and volume of the discharging lighter phase exiting through the openings 214a. It should be noted that although the openings 216a are shown as being at 90 to the inner face of member 60, such openings may be at an angle as small as 30 relative to such inner face of the member 60 and in a _'`', :' '`''' ' 11~4Z363 direction contrary to the fluid flow thereabove when it is desired to more than balance off the velocity head of the free vortex at the point of discharge of the heavy phase. It should be noted that the volume of the two openings 214a is ,, much greater than that of the duct or passage 214 so that the expelling action caused by the rotation of the control element 60 will always assure a vacuum at the point of exit, even at relatively high throughputs of the fluid. By reason of such construction, the control element 60 serves to bal-.
ance and compensate for the excess energy difference which would otherwise force a disproportionate part of the heavy phase from the apparatus in preference to the light phase.
Also, as noted above, the size of the opening 70b in the choke or orifice element 70 may be selected and varied if ,.
desired to regulate the amount of the discharge rate of the light phase compared to the discharge rate of the heavy phase.
Although the control assembly 60 is preferably used in conjunction with a choke assembly C or C-l, or a variation thereof, the control assembly may be used with other,inlet arrangements'for the separation or classifica-tion of the heavy and,the light phases of the fluid. It should also be pointed out that in some instances, the heavy phase which is discharged through the openings 216 is essen-tially all solids whereas the light phase which is discharged ,through the outlet 214 and 214a therewith is essentially all clear liquid.' In the case of liquid-liquid separation, the heavy phase will consist of the heavier liquid and the light . .
; phase will normally be the lightest liquid component of the liquid-liquid feed.

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~04Z363 The apparatus may also be used as a degasser for separating entrained gas from a liquid. The Fig. 4 form of the invention is, for example, suitable or use as a degas-ser by providing the size of the opening 114 small enough so that essentially only gas passes therethrough while the liquid discharges through the outlet 116. The Figs. 7 and 8 form of the invention may be similarly used.
The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape, and materials as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.

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Claims (12)

CLAIMS:

1. A cyclone centrifuge apparatus for separating or classifying at least two components of different densi-ties, comprising:
a housing having a separating chamber with an inlet, a first outlet and a second outlet;
a choke assembly disposed in said chamber downstream of said inlet for creating vortical flow in said separating chamber;
a static flow chamber section between said inlet and said choke assembly;
said choke assembly controlling substantially all flow of fluid from said inlet and said flow chamber to the portion of the chamber downstream from said choke assem-bly, whereby said fluid enters said separating chamber from a substantially static inlet feed, preventing the inlet fluid from cutting across the fluid flow in said separating chamber; and said choke assembly including:
a central vane support disposed in said housing and spaced radially therefrom to provide an annular area adjacent said static flow chamber;
helical vane means in said annular area and having an inner edge contacting said central vane support and an outer area contacting said housing to direct all fluid from said static flow chamber across said vane means before entering the rest of the housing; and said vane means having at least two terminal vane ends which are longitudinally spaced from each other, with a downstream vane end extending substantially radially, and an upstream vane end overlapping said downstream vane end for a dis-tance equal to approximately the radius of said central vane support and extending substantially parallel to said downstream end.

2. The apparatus set forth in Claim 1, wherein said helical vane means includes:
a single helical vane extending helically for slightly over 360° and disposed near said inlet and having said terminal ends thereof overlapping and longitudinally spaced from each other through which the fluid flows from said static flow chamber to the portion of said separating chamber downstream from said choke assembly.

3. The apparatus set forth in Claim 1, wherein said choke assembly also includes:
a choke element attached to one of said over-lapping ends and defining with the other overlapping end a predetermined orifice size for the choke.

4. The apparatus set forth in Claim 1, wherein:
said inlet is a tube disposed substantially radially with respect to said static flow chamber.

5. The apparatus set forth in Claim 1, wherein:
said inlet is a tube disposed substantially axially with respect to said static flow chamber.

6. The apparatus set forth in Claim 1, wherein said helical vane means includes:
a pair of helical vanes, each of which extends for slightly more than 180°; and each of said vanes having said terminal ends overlapping with and longitudinally spaced from the terminal ends on the other of said vanes, the extent of overlapping for each set of terminal ends being approximately equal to the radius of said central vane support, and the ends of each set being substantially parallel to each other for con-trolling the flow therethrough to develop free vortex flow of the fluid in the portion of said separating chamber down-stream from said choke assembly.

7. The apparatus set forth in Claim 1, including:
means for rotating said housing for imparting a forced vortex to the fluid flowing in the free vortex in said separating chamber.

8. The apparatus set forth in Claim 1, wherein said first and second outlets are both located at the oppo-site end of said chamber from said inlet, with the first outlet for the lighter-phase being at the central portion of the chamber, and with the second outlet for the heavier phase being at the outer peripheral area of the chamber.

9. The apparatus set forth in Claim 8, including:
means for rotating said housing for imparting a forced vortex to the fluid flowing in the free vortex in said separating chamber.

10. The apparatus set forth in claim 1, wherein:
said first outlet for the lighter phase is a tube disposed in the central portion of said choke assembly; and said second outlet for the heavier phase is disposed at the end of said chamber opposite from said inlet.

11. The apparatus set forth in claim 8, including:
a variable diameter opening at said first outlet for controlling the volume of fluid exiting as the lighter phase.

12. The apparatus set forth in claim 8, including:
means for rotating said housing;
means for directing the discharge of the heavier phase from said outer peripheral area to a central opening separate from said first outlet prior to discharge of said heavier phase from the apparatus; and means for directing the discharge of the lighter phase from said central portion at an angle to the central axis of said housing whereby a pumping action for increased separation is effected.