US3893922A

US3893922A - Cylindrical cyclone centrifuges

Info

Publication number: US3893922A
Application number: US315233A
Authority: US
Inventors: Roy A Bobo
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-12-14
Filing date: 1972-12-14
Publication date: 1975-07-08
Anticipated expiration: 1992-07-08
Also published as: BR7306113D0

Abstract

Cylindrical cyclone centrifuges wherein the heavy phase outlet is controlled so as to obtain efficient separation of the heavy phase from the light phase in a feed such as oil well drilling mud having such components and so as to inhibit undesirable plugging of the outlet for the heavy phase.

Description

United States Patent [191 Bobo [.451 July 8,1975

[ CYLINDRICAL CYCLONE CENTRIFUGES [76] Inventor: Roy A. Bobo, 2000 N. Loop West,

Suite 215, Houston, Tex. 77018 [22] Filed: Dec. 14, 1972 [21] Appl. No.: 315,233

[52] US. Cl. 209/211; 210/512 M [51] Int. Cl. B04c 3/06 [58] Field of Search 209/144, 211; 210/512 R, 210/512 M; 138/42 [56] References Cited UNITED STATES PATENTS 1,711,270 4/1929 Litle 138/42 1,915,867 6/1933 Penick 138/42 2,634,741 4/1953 Fontein 209/211 X 2,653,801 9/1953 Fontein et al.... 259/4 2,671,560 3/1954 Fontein et al.... 209/211 2,743,815 5/1956 Goodwin 209/211 2,776,053 1/1957 Krebs 209/211 2,843,265 7/1958 Rakowsky 209/211 X 3,277,926 10/1966 Skardal 209/211 X 3,306,357 2/1967 Cullen et a1. 138/42 X FOREIGN PATENTS OR APPLICATIONS 990,229 9/1951 France 209/21 1 Primary ExaminerFrank W. Lutter Assistant Examiner-Ralph J. Hill Attorney, Agent, or F irmPravel & Wilson [5 7] ABSTRACT Cylindrical cyclone centrifuges wherein the heavy phase outlet is controlled so as to obtain efficient separation of the heavy phase from the light phase in a feed such as oil well drilling mud having such components and so as to inhibit undesirable plugging of the outlet for the heavy phase.

6 Claims, 8 Drawing Figures CYLINDRICAL CYCLONE CENTRIFUGES BACKGROUND OF THE INVENTION The field of this invention is cyclone centrifuges.

In the past, cyclone centrifuges have been formed with a conical body and a cylindrical body. Although the cylindrical centrifuges have some definite advantages over conical centrifuges, such as better separation of the heavy phase solid particles from the light phase solid particles, less turbulence, and more orderly flow therethrough, the cylindrical centrifuges have had relatively limited use because the solids have tended to plug the outlet opening.

SUMMARY OF THE INVENTION The present invention relates to cylindrical cyclone centrifuges having means for separating heavy phase solid particles from light phase solid particles in a fluid flowing through the centrifuge, wherein the size of the discharge outlet for the heavy phase is great enough for the discharge of the heavy phase in fluid from the centrifuge without plugging the outlet, and wherein more effective separation is accomplished than with comparable conical centrifuges.

The invention specifically includes a cluster of cylindrical separators connected to a common heavy phase control means, whereby the heavy phase discharge is regulated by a single adjustable choke.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a cylindrical centrifuge of the type preferably used in the apparatus of this invention;

FIG. 2 is an elevation of the centrifuge of FIG. 1, showing further details thereof;

FIG. 3 is an elevation of a vortex regulating device which is connected to the heavy phase discharge outlet of the cyclone centrifuge of FIGS. 1 and 2;

FIG. 3A is a side view of the vortex regulating device of FIG. 3;

FIG. 4 is a view, partly in section and partly in elevation, showing a modified form of the heavy phase discharge control unit which may be used in place of that illustrated in FIG. 3 at the heavy phase outlet of the cyclone centrifuge of FIGS. I and 2;

FIG. 5 is another form of a heavy phase control unit which may be used in place of the devices of FIGS. 3 and 4 for controlling the pressure drop and the discharge of the heavy phase discharge from the cyclone centrifuge of FIGS. 1 and 2;

FIG. 6 is a horizontal sectional view, illustrating a plurality of cylindrical cyclone centrifuges, each of which may be identical to the centrifuge of FIGS. 1 and 2, and the section line being taken on lines 6--6 of FIG. 2 for each of the centrifuges, and with each of the centrifuges being connected to a common control unit for controlling the heavy phase discharge from the centrifuges; and

FIG. 7 is a sectional view taken on line 77 illustrating further details of one form of the heavy phase discharge control unit connected to the plurality of centrifuges.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, the letter C designates generally a cylindrical cyclone centrifuge which is adapted to receive a fluid such as drilling mud in liquid form having therewith solid particles which are to be separated into a light phase and a heavy phase by a cyclone flow through the centrifuge C. The present invention includes a heavy phase control means H-1, H-2, or H-3 for creating a predetermined pressure drop in the fluid discharging with the heavy phase solid particles so that the discharge outlet from the centrifuge C may be large enough to inhibit plugging thereof with the solid particles, while at the same time avoiding interference with the cyclone separation in the centrifuge C. In one embodiment of the invention, a plurality of centrifuges C (FIGS. 6 and 7) are mounted in a cluster, with the discharge of the heavy phase solid particles connected to a common control unit I-I-4.

The cyclone centrifuge C of FIGS. 1 and 2 includes a cylindrical tank 10 which has a closed upper end 11. An inlet pipe 12 is connected near the upper end of the tank 10 for introducing mud or other liquid with the solid particles to be separated tangentially so as to initiate the cyclone flow of the fluid through the tank 10.

The lower end of the tank 10 is closed as indicated by a bottom 14, except for a light phase outlet tube 15 in such bottom 14. As will be well understood, because of the cyclone action in the tank 10, the heavier solid particles move towards the outer vertical wall of the tank 10 and the lighter solid particles remain towards the center portion of the fluid as it moves in its cyclone path within the tank 10 so that when the fluid discharges at the lower end of the tank 10, the fluid portion at the center part of the tank 10 exits through the tube 15 and is largely lightweight particles, and in some cases substantially all liquid with very little of the solid particles. The solid particles on the other hand are discharged through a discharge outlet 18 which is welded or otherwise secured to the vertical wall of the cylindrical tank 10 so that it is in communication with the fluid internally of the tank 10 for the discharge of the heavy phase solid particles and liquid therewith.

Because of the unidirectional flow throughout the centrifuge C, there is a much better separation of the solid particles than with the cone cyclone centrifuges. There is also less turbulence and a more orderly flow of the fluid as it flows through the centrifuge C.

The size of the opening 18 is very important. If it is so small that the solid particles accumulate and plug it, the centrifuge will become inoperative after relatively short periods of time. On the other hand, if the opening in the pipe 18 is excessive, the cyclone separation within the centrifuge C is interfered with because too much of the solid particles exit through the discharge opening with the heavy phase. It has been found that such problem can be solved by the connection of a heavy phase control unit or means such as the unit I-I-1 with the discharge outlet 18.

The control unit H-l has an inlet tube 20 which is connected to the heavy phase discharge outlet 18 as indicated by the dash dot line in the drawings. The inlet tube 20 is welded or is otherwise mounted with a vortex regulating chamber 21 which has a discharge tube 22 at its central portion opposite the inlet 20. A free vortex is created within the chamber 21 in the known manner so that the fluid and solid particles discharging from the discharge tube 22 are essentially confined in a narrow ring in the outer portion of the tube 22, and with the central core of the vortex being formed by air which rushes in as a result of the vacuum created by the cyclone. Thus, the tube 22 acts as a choke or orifice.

Normally, approximately one velocity head will be expended in creating the free vortex in the chamber 21, but on the other hand, the pressure drop resulting from the discharge through the outlet tube 22 which serves as an orifice will be extremely high, considerably more so than the one velocity head. Therefore, the restricted discharge of the fluid from the heavy phase outlet 18 through the unit I-I-1 creates a pressure drop ofa predetermined amount so that the cyclone separation in the separator centrifuge C is not disturbed or interfered will but at the same time the discharge tube 18 and all tubes such as 20 and 22 are large enough so that the danger of plugging or closing them with the solid heavy phase particles is inhibited and usually prevented.

In FIG. 4 another form of control unit I-I-2 is illustrated, wherein a conduit 25 preferably connected directly to the discharge outlet 18 and having a diameter substantially the same size as the outlet 18, is formed with a series of sharp bends or angles. Such angles or bends create a back pressure and thus a predetermined pressure drop so that the size of the orifice 18 is large enough to prevent plugging thereof while at the same time the pressure of the fluid in the cyclone centrifuge C is not disturbed so that effective separation of the solids takes place.

In FIG. 5, a modified control unit H-3 is illustrated and it has a conduit which is adapted to be considerably connected to the discharge outlet 18. The size of the opening in the conduit 30 at the point of connection to the discharge outlet 18 is preferably the same or greater, and such conduit 30 is provided with a series of enlargements 31 with the conduit 30 being formed therebetween and at the outlet or discharge end. The enlargements 31 in conjunction with the conduits 30 of the smaller size therebetween, create a back pressure so that a predetermined pressure drop is provided for the discharging heavy phase solids and the liquid therewith so that the separation in the centrifuge C is not adversely affected and the plugging of the discharge outlet 18 is prevented or inhibited.

Although the size of the opening in the discharge outlet 18 for the heavy phase solids and the liquid therewith may vary depending upon operating conditions, for the guidance of those skilled in the art, the following is exemplary of the range of sizes which would be satisfactory under normal operating conditions for a drilling mud separation wherein it is desired to separate substantially all of the solid particles with the heavy phase discharge.

It has been found that for ordinary cylindrical centrifuges which do not have a control unit such as H-l through H-5 therewith. the maximum size of the open ing in the outlet 18 for effective separation of the heavy phase is not more than about 0.1 inch. With the present invention, using one of the control units H-l through H-3, the opening in the outlet 18 may be at least double the opening size without such a control unit under the same operating conditions. With the cluster arrange ment using the control unit H-4, the orifice opening 53a preferably is within the range of from about 0.35 to about 1.5 inches, and each outlet 18 may be any convenient size within such range. Thus, the opening in outlet 18 is greatly increased as compared to the prior art, and such increased size effectively eliminates plugging of the outlet 18 or discharge of the heavy phase solids. It also results in an extremely dry discharge of such heavy phase solids so that most of the liquid goes out through the pipe 15. It should be understood that the invention should not be limited to the foregoing sizes or size range because such sizes depend on a number of variable factors such as the pressure, fluid flow rate through the centrifuge and the density of the solids in the liquid. However, the foregoing range does emphasize the advantages of the present invention and particularly, the ability to use a larger outlet than heretofore was used so as to inhibit or prevent plugging thereof while still getting effective separation.

In FIG. 6, a cluster or assembly of cyclone centrifuges C, each of which is preferably identical to that illustrated in FIGS. 1 and 2, are shown connected to a common control unit H-4. The sectional view for each of the cylindrical centrifuges C in the cluster of FIG. 6 is taken along lines 66 of FIG. 2.

The control unit H4 is preferably formed with a body having a closed upper end 51 and an open lower end 52 which is adapted to receive a replaceable orifice member 53. The orifice or choke 53 is preferably held in position in the body 50 by a removable snap ring 54 mounted in an annular groove 50a in the known manner. The orifice or choke 53 has an opening 530 through which all of the heavy phase discharge from the cylindrical centrifuges C passes. The opening in such choke 53a is preferably at least as large as the inside diameter or opening in each of the heavy phase discharge outlets 18 with each centrifuge C.

It is to be noted that each of the discharge outlets 18 is threaded or is otherwise secured in a suitable opening in the side wall of the body 50. The other end of each outlet tube 18 for each cylinder 10 is welded or is otherwise secured to the cylinder 10.

By having all of the centrifuges C in the luster to FIG. 6 connected with a common control unit I-I-4, the back pressure or pressure drop of the heavy phase discharge may be controlled for all of such centrifuges C by the single choke 53 so that there is an adequate size for the discharge outlets 18 to prevent plugging thereof with the heavy phase solids and at the same time, efficient separation occurs in the cyclone centrifuges C.

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.

I claim:

1. Cyclone centrifuge apparatus, comprising:

a cylindrical separator tank having an upper inlet and a lower outlet, and a cylindrical vertical tank wall, which is entirely cylindrical, between said inlet and said outlet;

means for directing a feed fluid having solid particles of various weights therewith from said inlet in a direction to create a cyclone flow of such fluid within said tank to effect a separation of the solid particles into a heavy phase near said wall of said tank and a light phase towards the center of said tank;

said tank having a closed lower end with said lower outlet for the discharge of the light phase from said tank;

a heavy phase fluid outlet in the wall of said tank near its lower end for the discharge of the heavy phase of the solid particles; and

heavy phase control means connected to said heavy heavy fluid outlet only and having a plurality of means therewith for creating substantially equal successive pressure drops in the fluid discharging for thereby creating a predetermined pressure drop in the fluid discharging with said heavy phase with an adequate size for said outlet to inhibit plugging thereof with solid particles in said heavy phase while the same time avoiding an excessive pressure drop which would interfere with the cyclone separation in said cylindrical separator tank.

2. The centrifuge set forth in claim 1, wherein said means for creating said substantially equal successive pressure drops in said heavy phase control means includes:

a tubular conduit having a single passage therethrough with a series of sharp turns in said passage terminating in an exit for the fluid with said heavy phase.

3. The centrifuge set forth in claim 1, wherein said heavy phase control means includes:

a tubular conduit having a series of longitudinally spaced enlargements with passages therebetween, with each passage having substantially the same cross-sectional area as the other passages, and an outlet from which the fluid with the heavy phase discharges.

4. Cyclone centrifuge apparatus, comprising:

a plurality of cylindrical cyclone centrifuges;

each of said centrifuges having a cylindrical tank with an upper inlet and a lower outlet, and with a cylindrical vertical tank wall which is entirely cylindrical between said inlet and said outlet, means for directing a feed fluid having solid particles of various sizes therewith from each said inlet in a direction to create a cyclone flow of such fluid within said tank to effect a separation of the solid particles into a heavy phase near said wall of said tank and a light phase towards the center of said tank; a light phase outlet opening in the bottom of the tank, and a heavy phase outlet in the wall near the bottom; and

a single heavy phase control unit connected to the heavy phase outlet from each of said centrifuges by a flow line which is at least as large as said outlet and which has means for creating a predetermined pressure drop in the fluid discharging with said heavy phase from each centrifuge with an adequate size for each of said heavy phase outlets to inhibit plugging thereof while at the same time avoiding an excessive pressure drop which would interfere with the cyclone separation in each of said centrifuges.

5. The apparatus set forth in claim 4, wherein:

said control unit has a single outlet with a choke therein through which all of the heavy phase solids from said centrifuges are discharged.

6. The apparatus set forth in claim 5, wherein:

said choke is adjustable for adjusting the amount of said predetermined pressure drop in the heavy phase discharge from said centrifuges.

l l l

Claims

1. CYCLONE CENTRIFUGE APPARATUS, COMPRISING: A CYLINDRICAL SEPARATOR TANK HAVING AN UPPER INLET AND A LOWER OUTLET, AND A CYLINDRICAL VERTICAL TANK WALL, WHICH IS ENTIRELY CYLINDRICAL BETWEEN SAID INLET AND SAID OUTLET, MEANS FOR DIRECTING A FEED FLUID HAVING SOLID PARTICLES OF VARIOUS WEIGHT THEREWITH FROM SAID INLET IN A DIRECTION TO CREATE A CYLONE FLOW OF SUCH FLUID WITHIN SAID TANK TO EFFECT A SEPARATION OF THE SOLID PARTICLES INTO A HEAVY PHASE NEAR SAID WALL OF SAID TANK AND A LIGHT PHASE TOWARDS THE CENTER OF SAID TANK, SAID TANK HAVING A CLOSER LOWER END WITH SAID LOWER OUTLET FOR THE DISCHARGE OF THE LIGHT PHASE FROM SAID TANK, A HEAVY PHASE FLUID OUTLET IN THE WALL OF SAID TANK NEAR ITS LOWER END FOR THE DISCHARGE OF THE HEAVY PHASE OF THE SOLID PARTICLES, AND HEAVY PHASE CONTROL MEANS CONNECTED TO SAID HEAVY HEAVY FLUID OUTLET ONLY AND HAVING A PLURALITY OF MEANS THEREWITH FOR CREATING SUBSTANTIALLY EQUAL SUCCESSIVE PREASURE DROPS IN THE FLUID DISCHARGING FOR THEREBY CREATING A PREDETERMINED PRESSURE DROP IN THE FLUID DISCHARGING WITH SAID HEAVY PHASE WITH AN ADEQUATE SIZE FOR SAID OUTLET TO INHABIT PLUGGING THEREOF WITH SOLID PARTICLES IN SAID HEAVY PHASE WHILE THE SAME TIME AVOIDING AN EXESSIVE PRESSURE DROP WHICH WOULD INTERFERE WITH THE CYCLONE SEPARATION IN SAID CYLINDRICAL SEPARATOR TANK.

2. The centrifuge set forth in claim 1, wherein said means for creating said substantially equal successive pressure drops in said heavy phase control means includes: a tubular conduit having a single passage therethrough with a series of sharp turns in said passage terminating in an exit for the fluid with said heavy phase.

3. The centrifuge set forth in claim 1, wherein said heavy phase control means includes: a tubular conduit having a series of longitudinally spaced enlargements with passages therebetween, with each passage having substantially the same cross-sectional area as the other passages, and an outlet from which the fluid with the heavy phase discharges.

4. Cyclone centrifuge apparatus, comprising: a plurality of cylindrical cyclone centrifuges; each of said centrifuges having a cylindrical tank with an uppeR inlet and a lower outlet, and with a cylindrical vertical tank wall which is entirely cylindrical between said inlet and said outlet, means for directing a feed fluid having solid particles of various sizes therewith from each said inlet in a direction to create a cyclone flow of such fluid within said tank to effect a separation of the solid particles into a heavy phase near said wall of said tank and a light phase towards the center of said tank; a light phase outlet opening in the bottom of the tank, and a heavy phase outlet in the wall near the bottom; and a single heavy phase control unit connected to the heavy phase outlet from each of said centrifuges by a flow line which is at least as large as said outlet and which has means for creating a predetermined pressure drop in the fluid discharging with said heavy phase from each centrifuge with an adequate size for each of said heavy phase outlets to inhibit plugging thereof while at the same time avoiding an excessive pressure drop which would interfere with the cyclone separation in each of said centrifuges.

5. The apparatus set forth in claim 4, wherein: said control unit has a single outlet with a choke therein through which all of the heavy phase solids from said centrifuges are discharged.

6. The apparatus set forth in claim 5, wherein: said choke is adjustable for adjusting the amount of said predetermined pressure drop in the heavy phase discharge from said centrifuges.