US3648840A

US3648840A - Rotating cyclone centrifuge

Info

Publication number: US3648840A
Application number: US846886A
Authority: US
Inventors: Roy A Bobo
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-08-01
Filing date: 1969-08-01
Publication date: 1972-03-14
Anticipated expiration: 1989-03-14

Abstract

A rotating cyclone centrifuge wherein a forced fluid vortex from rotation of a cyclone is combined with a free fluid vortex from a pressure drop of the fluid for effecting improved separation or classification of various mixtures and suspensions.

Description

United States Patent Bobo 51 Mar. 14, 1972 [54] ROTATING CYCLONE CENTRIFUGE 2,996,187 8/1961 Payne ..209/211 72 Inventor: Roy A. Bobo, 6139 Bardley St., Houston, 31252:: 2x32; I 11258331, 77027 3,288,286 11/1966 Prins 6:61. ..209/144 x d: A 1,1969 We FOREIGN PATENTS OR APPLICATIONS l. N 6 App 84688 971,939 10/1965 Great Britain ..209/211 [52] U.S. Cl ..209/211, 55/400, 55/459, Primary ExaminerFra.nk W. Lutter 210/512 Assistant Examiner-Ralph J. Hill [51 Int. Cl. ..B04c /00 v Anorney-Prave1, Wilson & Matthews [58] Field of Search ..209/144, 21 1; 55/400, 459;

' 210/512; 233/27 [57] ABSTRACT [56] References Cited A rotating cyclone centrifuge wherein a forced fluid vortex from rotation of a cyclone 1s combmed w1th a free fluid vortex UNXTED STATES PATENTS from a pressure drop of the fluid for effecting improved separation or classification of various mixtures and suspen- 3,373,874 3/1968 Kompert ..55/459 X siom 3,025,965 3/1962 Bergman et al ..210/512 2,701,642 2/1955 Goodwin ..210/512 X Claims,7 Drawing Figures 359 /o& 220 I 35a 3% 551 r J/ A 4 22 l J /5a /5a a [a T f-lfb l 456 Z a l My /a l 1 l {1 5/ J s/ J PAIENTEUMAR 14 I972 SHEET 1 [IF 2 Roy A. .Bbo

INVEN TOR plume! WZIAW & MaMewA A TTORNE YS ROTATING CYCLONE CENTRIFUGE BACKGROUND OF THE INVENTION The field of this invention is cyclone separators and classiflers.

In the past, various cyclone types of separators have been utilized, and many efforts have been made to improve their effectiveness. For example, efforts have been made to improve conventional cyclone separators by adding internal impellers or vanes such as disclosed in US. Pat. Nos. 2,787,374; 2,996,187; 3,172,844; and 3,235,090. Although each of such patents purports to obtain an increased force or separating effeet above that obtained with a free vortex due to the conventional cyclone separation, none of the apparatus of such patents is capable of doing so. The solution to the problem of more effective separation with a cyclone separator has thus remained unsolved for the many years in which cyclone separators have been used, even though workers in the art have tried to solve the problem, as evidence by the unsuccessful attempts in such prior patents.

SUMMARY OF THE INVENTION This invention relates to a cyclone separator which has means therewith for rotating same while at the same time introducing fluid under pressure into the cyclone through an orifice or restriction, whereby the velocity imparted to the incoming fluid by the pressure drop through the orifice is added to the velocity of the fluid due to the rotation of the cyclone for obtaining an increased force or separating effect. With the present invention, large increases in centrifugal force are obtained in the section of the cyclone near its wall, and such increased centrifugal force is effective over a relatively long travel time for the fluid as it flows in the cyclone, for thereby obtaining improved separation and/or classification as compared to the prior art devices. Because of the effect of the rotation in combination with the effect of pressure transformation, a large rotating cyclone can actually be made more effective than a smaller size of a cyclone, thus resulting in a far greater throughput of fluid with equal or better classification than is possible with the smaller fixed cyclone. Not only is the present invention suitable for separating solids from liquids, but it also is suitable for separating of solids from gases, classification of solids in either solids-liquid mixtures or suspensions or solids-gaseous mixtures or suspensions, and even for separating liquids of different densities from each other.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view, partly in elevation and partly in section, illustrating the preferred form of the invention; and,

FIG. 2 is a horizontal sectional view taken on line 2-2 of FIG. 1, and such FIG. 2 shows the cut line l-l for FIG. 1;

FIG. 3 is an enlarged perspective view of one form of inlet orifice or choke used in the present invention;

FIG. 4 is a front elevation of the preferred form of the apparatus of this invention as shown in FIG. 1;

FIG. 5 is an enlarged detailed view of a portion of the apparatus of FIGS. 1 and 4, but showing an alternate form of the invention with respect to the inlet restriction;

FIG. 6 is a view taken on line 66 of FIG. 5 to further illustrate the modified form of the invention of FIG. 5; and

FIG. 7 is an isometric view of one removable orifice plate which is suitable for use in conjunction with the form ofthe invention shown in FIGS. 5 and 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawings, the letter A designates generally the rotating cyclone centrifuge of this invention. The apparatus A includes a cyclone housing H which is adapted to be mounted for rotation and which is connected to a fluid, which may be solids-liquid, solids-gases, or liquid-liquid mixtures or suspensions, is introduced into the rotating housing H in the same direction as the direction of rotation of the housing H and at a velocity which is equal to or greater than the velocity of rotation of the housing H. With the present invention, the free vortex of the fluid is formed in the cyclone housing H so that the inward radial motion of the fluid is obtained as in the conventional cyclone apparatus, but at the same time, the rotating housing H imparts a centrifugal force to the particles of the fluid to exert an outward radial force which tends to cause a separation of particles of different densities to a far greater extent than is possible with the conventional cyclone apparatus.

Considering the invention more in detail, the housing H is in the shape of a cone as illustrated in FIGS. 1 and 4, although it may be in the shape of a cylinder throughout its length. The lower end of the housing H is mounted in a pillow block bearing 10 or any other suitable bearing support which is secured to a fixed plate or support 11 by any suitable securing means such as bolts 12 (FIG. 4). The plate or support 11 may be a section of steel which is welded or is otherwise secured to substantially vertical frame members or wall sections 14 (FIG. 4).

The fluid feed inlet assembly F is composed of two principal sections, a rotatable section 15, and a fixed inlet section 16. The rotatable fluid inlet section 15 is rotatable with the housing H and it serves as the upper end of the housing H, as will be more evident hereinafter. In the preferred form of the invention, the rotatable fluid inlet section 15 is connected to the housing H by means of a plurality of capscrews 18 which extend through a radial flange 19 on the housing H and a similar flange 20 on the lower end of the rotatable inlet section 15. A gasket 21 is preferably disposed between

flanges

19 and 20 to prevent fluid leakage or escape therebetween.

The rotational section 15 has an intermediate cylindrical portion 22 which has an upper pillow block bearing 25 or other suitable bearing support mounted thereon for supporting the upper end of the housing H for rotation. The pillow block bearing corresponds essentially to the pillow block bearing 10, but it is mounted upon a separate upper plate 26 which is preferably mounted between the two vertical supports or wall members 14 (FIG. 4).

The intermediate cylindrical portion 22 of the rotatable fluid inlet section 15 has a sheave 30 connected thereto by a key 31 or other suitable connection. Such sheave 30 is adapted to be driven by a motor through conventional V-belts or other drive mechanism. The rotation of the sheave 30 imparts rotation to the housing H through the fluid inlet section 15 so that the housing H and the section 15 both rotate together in the preferred form of the invention.

The rotatable section 15 also has an upper cylindrical tube 22a extending upwardly from the intermediate cylindrical portion 22 so as to telescope or fit within the bore of the fixed fluid inlet section 16. A seal such as the stuffing box seal 35 (FIG. 1) is preferably employed for providing a fluidtight seal between the movable section 15 and the fixed section 16. A replaceable wear sleeve 22b is disposed externally of the tube 22a and is removably secured thereto by a plurality of lock or set screws 36 or other suitable securing means which extend through a lock ring 37 disposed near the lower end of the sleeve 22b. The screws 36 extend through the ring 37 and frictionally engage the external surface of the tube 220 so as to lock the sleeve 22b thereto.

The seal 35 may be formed in numerous ways, but as illustrated in FIG. 1, it includes an upper gland 35a, an intermediate gland 35b and a lower gland or ring 35c. A seal ring such as an O-ring 35d formed of rubber or other suitable material is disposed between the packing glands 35a and 35b and pressure is exerted thereon by a resilient member such as a spring 35c which is disposed within the chamber 16a defined by the lower section 16b and upper section 16c. The sections 16b and are removably secured together by any suitable means such as capscrews 40. A pipe 41 is threaded into the upper portion 16c and it is in communication with a source of the fluid which is to be separated or classified.

The fixed fluid feed inlet section 16 is secured to the plate 26 by means of a strap 42 or the like which fits around the portion 16b and which has plurality of retaining screws or bolts 43 extending therethrough into the plate 26 (FIG. 4). The bear ing 25 is connected to the plate 26 by any suitable means such as bolts or screws 44 which extend through side extensions 2511 on the bearing 25 and into the plate 26 (FIG. 4).

In addition to the seal ring 35d in the stuffing box seal 35, another seal ring 35f formed of rubber or similar resilient material is disposed between the metal ring 350 and the lower flange of the bottom portion 16b of the inlet section 16. Thus, when the lower fluid feed inlet section rotates relative to the upper fluid feed inlet section 16, the wear sleeve 22b rotates relative to the stuffing box seal 35 so that any wear which occurs by reason of such relative movement, occurs on the external surface of the wear sleeve 22b and the internal surfaces of the seal parts 35a, 35b, and 350. The seal ring 35d may also be subjected to some wear, but that wear is compensated automatically by the urging of the spring 35e, as previously noted. When sufficient wear occurs to justify a replacement of the seal 35d, and any of the other parts, the capscrews 40 may be removed and the assembly separated to replace the necessary parts.

The bore of the intermediate cylindrical portion 22 of the rotatable feed inlet section 15, and the bore of the tube 220 thereabove are in fluid communication with the inlet pipe 41 so as to receive the incoming fluid feed from whatever source is used. Such bore 22c is also in communication with one or more ports 15a which direct the incoming fluid feed to an inlet orifice, choke or restriction member 45 (FIG. 1, 2 and 3). Because the section 15 is rotating, the fluid in the bore 220 is thrown or pumped outwardly through the horizontal leg of each port 150 to the vertical leg thereof so as to develop a high velocity and pressure of the fluid as it moves to and through the restriction 45. Such inlet orifice or restriction member 45 may be formed in different ways, but as specifically illustrated in FIG. 3, such member 45 is in the form ofa cylinder having an open upper end 45a and a side opening or orifice 45b. The inlet section 15 is provided with a suitable enlarged hole 15b into which the upper portion of the inlet orifice 45 is adapted to be inserted, preferably with a resilient seal ring 46 thereabove (FIG. 1). The ring 46 is compressed into fluidtight sealing engagement so as to prevent leakage of the incoming fluid around the external part of the orifice 45. The inside surface 190 of the flange 19 of the housing H extends inwardly a sufficient amount to engage the closed bottom 450 of the orifice member 45 so as to firmly clamp same into position when the capscrews 18 are fully threaded into their secured position as shown in FIG. 1. The opening 45b is disposed so as to direct the discharge of the incoming fluid from the orifice member 45 tangentially to the inner cylindrical wall 50 at the upper end of the housing H and substantially horizontally. However, the opening 45b may be disposed at an angle to either side of a tangent to the wall 50 for changing the effective separation of components in a fluid. Also, instead of the fluid being discharged substantially horizontally, it may be discharged in a downward or axial direction to obtain the maximum separating effect. The fluid feed inlet section 15 preferably has openings 15c (FIG. 2) which are arranged for substantially tangential discharge from the openings 45b of the orifice members 45 as thus seen in FIG. 2. Such flow, due to the pressure drop or transformation of the fluid as it flows through the restriction 45, creates a free vortex within the housing H and results in a cyclone type of action. The size of the orifice opening 45b in each of the orifice members 45 determines the pressure drop which is obtained as the fluid flows from the inlet section 15 into the housing H and such pressure drop or pressure transformation of the incoming fluid feed is a factor in the ultimate separation or classification which occurs as the fluid moves downwardly within the housing H. As will be more fully explained hereinafter, the incoming fluid is at a velocity which is equal to or greater then the velocity of rotation of the housing H. The rotating housing H creates a forced fluid vortex which exists simultaneously with the free fluid vortex from the pressure transformation.

Although the preferred form of the invention includes at least two orifice members 45, it should be understood that the number of the orifice members may vary, so that there may be only a single orifice member 45, or there may be more than two of such members 45.

At the lower end of the housing H, the outlet for the underflow or the heavier density portion of the fluid is provided and it includes a variable diameter flexible outlet 51 which is a ring that is adapted to be compressed by a threaded ring or collar 52. The inside diameter 51a of the flexible ring 51 may thus be decreased by threading the metal ring 52 upwardly to compress the ring 51. Conversely, by unthreading the ring 52, the flexible member 51 may be relaxed and the diameter 51a may be increased. The outlet 51 of the housing H thus is varied to control the quality and the quantity of the underflow, as will be more evident hereinafter.

Various means other than the flexible member 51 may be employed to vary the size of the outlet for the underflow at the lower end of the housing H. For example, the ring 51 may be eliminated and variations in the outlet opening may be obtained with separately insertable and removable orifice rings 52 of different inside diameters.

The effluent or overflow from the housing H is discharged through a vortex finder 55. Such vortex finder 55 extends downwardly from the section 15 and is disposed in the central portion of the housing H near its upper end and it includes a bore 55a which is in communication with one or more outlet openings 15d in the rotatable fluid feed inlet section 15. The vortex finder 55 may be threaded into the section 15 as indicated at 551;, or it may be otherwise suitably affixed so that it is capable of receiving the lighter density portion of the fluid which moves radially inwardly in the cyclone housing H. Because ofthe rotation of the unit or section 15, the effluent is pumped or thrown outwardly from the upper end of the vortex finder 55 through each port 15d. Such pumping is due to the centrifugal force and a resultant partial vacuum created at the upper end of the vortex finder 55. Thus, the section 15 has two pumps, the inlet pump through ports 15a and the outlet pump through ports 15d.

The outlet openings 15d communicate with a circular flume 60 which is preferably disposed around the external surface of the rotatable section 15, but which is preferably secured to the walls or vertical members 14 so that it does not rotate with the section 15. Any effluent or overflow from the outlet openings 15d into the flume 60 is removed therefrom by any suitable means such as by drawing through an outlet tube 600 (FIG. 4) or by being pumped therefrom.

In the operation or use of the apparatus A of this invention, the fluid which is to be separated or classified is introduced from a suitable source through the pipe 41 and it then flows through the feed inlet assembly F to the inlet and to the housing H. The orifice 45 provides a restriction so as to create a pressure drop as the fluid feed flows from the feed inlet assembly F into the housing H. The housing H and the pans connected therewith are rotated, as previously explained, by any suitable power source (not shown) connected to the sheave 30 or any other driving means. The velocity of the incoming feed is equal or greater than the velocity of rotation of housing H, and preferably, the feed is directed tangentially to the inner wall 50 of the housing H. In some cases the feed may be directed tangentially and axially for separating effects but, preferably the feed is essentially tangential as illustrated in particular in FIG. 2 of the drawings.

In conventional cyclone apparatus, the centrifugal force is far greater in the inner portion of the cyclone vessel near the air core than at or near the periphery. However, with the present invention, the centrifugal force is increased in the area along the inner wall 50 of the housing H so as to obtain a far greater separating effect while at the same time obtaining the advantages of the free vortex which causes separation in the inner portion of the cyclone vessel. Thus, with the present invention, the incoming fluid feed is subjected to the effect of the rotation of the housing H to obtain the centrifugal force effeet on the feed, while at the same time the fluid is subjected to the pressure transformation so as to form a free vortex due to the flow of fluid as it flows downwardly in the housing H.

The present invention is suitable for separating or classifying solids from liquids or from gases and it is likewise suitable for separating liquids of different specific gravities from each other in a mixture or a suspension. The heavier density portion of the incoming feed, whether it be solids or liquids, is caused to move outwardly along the wall of the housing H and to thus move downwardly to the outlet opening 51 as the underflow or discharge. The lighter specific gravity material, whether it be liquids or gases, is directed to the inner portion of the cyclone housing H due to the free vortex effect, and it flows as the effluent or overflow through the vortex finder tube 55 and is discharged through the outlet openings of d into the flume 60.

Thus, with the present invention, a greater centrifugal force is obtained for the same rate of fluid feed throughput over the entire vessel cross section, as compared to the conventional cyclone separator. Additionally, large increases in the centrifugal force are obtained in the section of the housing H near the walls thereof so that such increase is effective over a longer travel as the fluid moves downwardly in the housing H to provide greatly improved classification as compared to prior cyclone separators.

When solids are being classified or separated from a liquid or gas, the tangential velocity of the fluid due to pressure is maintained sufficiently high to scour particles off the bowl walls and to convey them to the underflow.

A modified form of the fluid feed inlet restriction 145 is provided as illustrated in FIGS. 5-7. All of the parts of such illustration which are the same as shown in FIGS. 1-4 bear like numerals and letters. The inlet opening 115a in FIGS. 5 and 6 compares with the inlet opening 15a of FIG. 1, but it is modified so as to establish communication with laterally extending tangential ports 1150, in which are disposed orifice restriction members 145. The construction of the orifice restriction member 145 includes upstanding lips 145a which extend into suitable notches or grooves ll5e and 11% in the section 15 and flange 19, respectively, for retaining the restriction member 145 fixed into position during use. The size of the opening or restriction is varied by varying the width of the body portion 14512 of the member 145, as will be evident from FIG. 6. Thus, when the width of the body portion l45b is increased, the remaining portion of opening 1150 is reduced and thereby, the size of the restriction opening is reduced. Should the members 145 become worn during use because of the impingement of solid particles or other material thereon as they flow into the housing H from the feed inlet assembly F, such members 145 may be readily replaced by separating the housing H from the feed inlet assembly F in the same manner as described hereinabove in connection with FIG. 1.

Although the apparatus is illustrated with the vortex finder 55 at the upper end of the housing H, it should be understood that the vortex finder 55 may be at the lower end of the housing when the housing H is cylindrical throughout its full height. In such case, the heavier phase discharges at the outer portion of the lower end of the housing H, and the lighter phase also discharges downwardly through the substantially central portion of the lower end of the housing H. In other words, the invention is not limited to the discharge of the two components from the housing H in the specific directions described in detail above.

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.

lclaim:

1. A separator or classifier, comprising:

a rotatable unit, having an inlet near one end, a first outlet near the other end, and a second outlet near said one end,

said inlet, first and second outlets being connected to said rotatable unit and rotatable therewith;

means for introducing a fluid through said inlet for creating a free vortex of fluid having at least two components of different densities; and

means including said rotating unit for subjecting the fluid in the free vortex to a forced vortex at the same time to thereby create combined inward and outward radial separating forces on the components of the fluid.

2. The structure set forth in claim 1, including:

means for providing additional pumping in said rotating unit of the incoming fluid feed to develop a high velocity and pressure for the fluid feed; and

pump means in said rotating unit for pumping the lighter density effluent from the combined forced vortex and free vortex.

3. A separator or classifier, comprising:

a rotatable housing, having an inlet near one end, a first outlet near the other end, and a second outlet near said one end, said inlet, first and second outlets being connected to said rotatable housing and rotatable therewith;

means for mounting said housing for rotation;

a fluid feed inlet assembly for feeding fluid to said inlet of said housing in the direction of rotation of said housing and at a velocity which is at least equal to the velocity of rotation of said housing to create a free vortex of the fluid within the housing;

said second outlet comprising a vortex finder tube disposed substantially in the central portion of said housing for the discharge of the lighter portion of the feed as the effluent from said housing while the heavier portion discharges as the underflow through said first outlet; and

rotating means for rotating said housing while the fluid feed is entering said housing under pressure for adding the force of rotation of said housing to the fluid in the free vortex to thereby provide a forced vortex additive with the free vortex of the fluid.

v 4. The structure set forth in claim 3, wherein said fluid feed inlet assembly includes:

a rotatable section operably connected to said cyclone housing and rotatable therewith; and

a fixed section having a rotatable connection with said rotatable feed inlet section for permitting rotation of said rotatable section relative to said fixed feed inlet section.

5. The structure set forth in claim 4, including:

a first pump means in said rotatable section for creating a high fluid pressure due to the rotation of said rotatable section; and

a second pump means in said rotatable section operable by the rotation of said rotatable section for pumping the effluent from said vortex finder.

6. The structure set forth in claim 3, including:

means for causing the fluid feed into said housing to be at a velocity greater than the velocity at which said housing is being rotated by said rotating means.

7. The structure set forth in claim 3, wherein said inlet into said housing includes:

means for directing said fluid feed into said housing in substantially the same direction as the direction of rotation of said housing and at a velocity equal to or greater than the velocity of rotation of said housing.

8. The structure set forth in claim 3, including:

means for adjusting the size of said outlet opening for controlling the quantity and quality of the underflow discharge from said cyclone housing.

9. The structure set forth in claim 3, wherein said outlet from said housing includes:

a compressible resilient ring which is adapted to be compressed for reducing the size of the opening therethrough; and

a longitudinally adjustable compression element for applying a compressive force to said resilient ring for adjusting the size of the opening therethrough.

10. The structure set forth in claim 3, wherein:

said housing has an upper cylindrical portion and a lower conically shaped portion.

Claims

1. A separator or classifier, comprising: a rotable unit, having an inlet near one end, a first outlet near the other end, and a second outlet near said one end, said inlet, first and second outlets being connected to said rotatable unit and rotatable therewith; means for introducing a fluid through said inlet for creating a free vortex of fluid having at least two components of different densities; and means including said rotating unit for subjecting the fluid in the free vortex to a forced vortex at the same time to thereby create combined inward and outward radial separating forces on the components of the fluid.

2. The structure set forth in claim 1, including: means for providing additional pumping in said rotating unit of the incoming fluid feed to develop a high velocity and pressure for the fluid feed; and pump means in said rotating unit for pumping the lighter density effluent from the combined forced vortex and free vortex.

3. A separator or classifier, comprising: a rotatable housing, having an inlet near one end, a first outlet near the other end, and a second outlet near said one end, said inlet, first and second outlets being connected to said rotatable housing and rotatable therewith; means for mounting said housing for rotation; a fluid feed inlet assembly for feeding fluid to said inlet of said housing in the direction of rotation of said housing and at a velocity which is at least equal to the velocity of rotation of said housing to create a free vortex of the fluid within the housing; said second outlet comprising a vortex finder tube disposed substantially in the central portion of said housing for the discharge of the lighter portion of the feed as the effluent from said housing while the heavier portion discharges as the underflow through said first outlet; and rotating means for rotating said housing while the fluid feed is entering said housing under pressure for adding the force of rotation of said housing to the fluid in the free vortex to thereby provide a forced vortex additive with the free vortex of the fluid.

4. The structure set forth in claim 3, wherein said fluid feed inlet assembly includes: a rotatable section operably connected to said cyclone housing and rotatable therewith; and a fixed section having a rotatable connection with said rotatable feed inlet section for permitting rotation of said rotatable section relative to said fixed feed inlet section.

5. The structure set forth in claim 4, including: a first pump means in said rotatable section for creating a high fluid pressure due to the rotation of said rotatable section; and a second pump means in said rotatable section operable by the rotation of said rotatable section for pumping the effluent from said vortex finder.

6. The structure set forth in claim 3, including: means for causing the fluid feed into said housing to be at a velocity greater than the velocity at which said housing is being rotated by said rotating means.

7. The structure set forth in claim 3, wherein said inlet into said housing includes: means for directing said fluid feed into said housing in substantially the same direction as the direction of rotation of said housing and at a velocity equal to or greater than the velocity of rotation of said housing.

8. The structure set forth in claim 3, including: means for adjusting the size of said outlet opening for controlling the quantity and quality of the underflow discharge from said cyclone housing.

9. The structure set forth in claim 3, wherein said outlet from said housing includes: a compressible resilient ring which is adapted to be compressed for reducing the size of the opening therethrough; and a longitudinally adjustable compression element for applying a compressive force to said resilient ring for adjusting the size of the opening therethrough.

10. The structure set forth in claim 3, wherein: said housing has an upper cylindrical portion and a lower conically shaped portion.