JPS6059018B2 - Centrifuge and how to operate it - Google Patents

Description

[Detailed description of the invention] The present invention relates to a centrifuge and a method of operating the same.

Centrifugal separators or centrifuges are well known for a variety of uses, and are devices for separating liquid mixtures into relatively high and relatively concentrated specific gravities, and in one particular application, Some systems separate solids continuously and by centrifugal force from a slurry with a high content of , and the solids are pumped to the site where they are used. For example, a slurry of coal and water is dehydrated at the discharge end of a transfer vibrate line and removed as relatively water-free coal. Mine backfill material (Minebach)
It is also well known to transport waste minerals hydraulically to provide fillmateri.

However, current separators do not have the ability to process such slurries and produce a useful discharge or discharge in sufficient quantities to provide backfilling in a practical manner; To date, no mining system has been found that dewaters mineral slurry. The advantages of providing a backfilling material with a desired concentration are described in detail in Japanese Patent Laid-Open Publication No. 13057/1983 filed by the present applicant.
This disclosure is incorporated herein by reference to facilitate an understanding of the present invention. As is well known, scrap minerals are obtained from processed ores and are generally 600 micron to submicron particles, which can be advantageously utilized for backfilling.

Among the various types of separators currently in use, screen-type centrifuges are inadequate for dewatering scrap mineral slurry because they are not designed to handle fine particles. In order to obtain a significant amount of dehydrated scrap ore in the mine,
The higher the solids content of the slurry, the more practical it is, and conventional high solids content slurries typically have a solids content of 50-65% by weight. Solids contents in this range are too high for separation in Tesk bowl or self-discharge centrifuges. In order to dewater the brown ore slurry underground, it is necessary to use a centrifuge to move it within the mine passageway. Therefore, large machines such as solid bowl type or conveyor type centrifuges cannot be used. For similar reasons, it is difficult to use many conventional centrifuges in parallel or in sequence in underground mines. The centrifuge according to the invention overcomes the above-mentioned drawbacks of conventional centrifuges and has a size that allows it to be placed in and moved within existing passageways in a mine, and A centrifuge is provided which is capable of discharging dewatered dross at a rate capable of providing the required amount of backfill material for mining.

In particular, the separation bowl is shaped to form a certain amount of solids (hereinafter referred to by the term beach zone) such that the rate of material release from the input slurry is such that the beach zone is formed. The solids discharge rate from the centrifuge is controlled to be equal to, or, as desired, approximately equal to the solids separation rate of the centrifuge. It is therefore an object of the present invention to provide a new and improved centrifuge that continuously discharges material with a high solids content in relation to the solids content of the input slurry.

Another object of the invention is to provide a centrifuge with a bowl shaped to provide continuous and controlled discharge of material.

Another object of the invention is to separate the separation and discharge functions of the centrifuge and operate the centrifuge to create a beach zone of material within the centrifuge.

Yet another object of the invention is to ensure that the rate at which solid particles of the slurry are deposited within a zone of the centrifuge is equal to, or approximately equal to, as desired, the rate at which such particles are ejected from the centrifuge. The purpose is to operate a centrifuge. Another object of the invention is to operate a centrifuge with variable discharge rate and continuous discharge of material consisting mainly of solid particles.

Another object of the invention is to have any one of a selectable bowl shape to provide a uniform flow or movement of the deposited solid particles through the zone separating the separation and discharge sections of the centrifuge. Our goal is to provide centrifuges.

A centrifuge according to the present invention includes a housing, a long shaft rotatably supported by the housing and rotating about its longitudinal central axis, and a long shaft rotatably supported by the shaft and relative to the shaft. axially positionable,
a pair of bowl members defining a centrifugal chamber having a periphery spaced radially outwardly from the central axis; a solid being entrained in the centrifuging chamber by a fluid medium in at least one of the bowl members; passage means for supplying a slurry of particles and continuously discharging effluent from said centrifugation chamber; and rotating said shaft, thereby converting the slurry supplied to said centrifugation chamber into a solids component and an effluent component. an axial rotation means carried by at least one of said members such that peripheral portions of said bowl members successively engage each other to deposit said solids component in said centrifugation chamber; and at least one axial position such that the peripheral portions are axially spaced apart from each other such that the accumulated solids component can be discharged from the centrifugation chamber during a period of time. and means for selectively axially displacing at least one of the bowl members, the bowl member having an interior portion such that the volume of the solids component thus deposited remains substantially constant during the period of time. Some are characterized by having a shape.

The method of operating the centrifuge according to the present invention is such that the bowl members are continuously engaged with each other in a state in which peripheral portions of the bowl members radially outward of the central axis are continuously engaged with each other. During an initial period of time during rotation, a portion of the slurry that is continuously flowed into the interior of the bowl member is separated into a solids component consisting primarily of solid particulate solids, where the solids increases radially relative to the central axis over the initial period until the solid material extends from within the engaged periphery of the bowl member to a radially outwardly adjacent portion of the shaft. wherein the portion of the solid material adjacent to the shaft axially surrounds the entire length of the shaft within the bowl member and extends axially to a radial percentage that is substantially less than a maximum radial percentage of the solid material. defines a flow path extending in the direction;
over the initial period, separating a portion of the incoming slurry into an effluent component consisting primarily of the fluid medium;
A portion of the effluent component is discharged from one axial end of the flow path to the exterior of the bowl member such that the periphery of the bowl member is aligned with respect to the central axis for a subsequent period of time. While the bowl members continue to rotate in an axially spaced manner, incremental solids components are added to the solids to maintain a substantially uniform radial proportion of the solids over the duration. a portion of the additional slurry that is continuously flowed into the interior of the bowl member at a rate that simultaneously separates a portion of the additional slurry into a solids component and an effluent component while discharging a portion of the solids to the exterior of the bowl member. , and therewith, continuously discharging a portion of said effluent component of an additional slurry from one axial end of said channel for said duration. It is characterized by this.

Hereinafter, the present invention will be described in detail with reference to the drawings.

Rotating bowl centrifuges, such as the one shown in FIG. 1, are well known and include a housing 10 that is rigidly formed.

The housing 10 has vertically aligned bearings 12, 12 at its upper and lower portions and rotatably supports a shaft 14 about the housing 10 vertical rotation axis XX. Shaft 14 includes a controllable motor (not shown)
Accordingly, it is rotationally driven as described herein. The motor is equipped with a drive belt 16 which can cooperate with a pulley 18 which is rigidly fixed to a shaft 14 projecting from the top of the housing 10. The shaft 14 has a vertically extending central passage 20 therein, the upper end of which is open and which cooperates with the feed tube 22. , the materials are fed into a slurry which is then separated in a centrifuge. A separation chamber or bowl 24 disposed within the housing 10 includes an upper bowl member 24a.
and a lower bowl member 24b, each having a shaft 1
The lower bowl member 24b of the bowl is formed with an acceleration chamber 26 which extends laterally and outwardly from the inner lower end of the central passageway 20. It communicates with a downwardly extending outlet 28. The upper bowl member 24a has a central annulus chamber 30 at the top that surrounds the top of the shaft 14 within the bowl member 24. The bowl 24 has circumferentially spaced outlets 32 extending above and outwardly from and in communication with the central annulus chamber 30 . A material discharge gap 34 is formed between the outer circumferential ends of the upper bowl member 24a and the lower bowl member 24b, as will be described below.The centrifugal action of the centrifugal mixture is introduced through the feed tube 22 and then , central passage 20, exit 2
8. Enter the bowl 24 through the acceleration chamber 26.

In this bowl 24 the mixture is separated, the heavier part (solids) being discharged through the discharge gap 34 and the lower part being discharged through the outlet 32. For the purposes of the invention, the feed tube, drive means, bearings,
The construction of the shaft, acceleration chamber, outlet and housing may be well known and therefore no detailed description will be necessary. A preferred embodiment of the acceleration chamber 26 has a structure as disclosed in Japanese Unexamined Patent Publication No. 53-130574. Accordingly, the disclosures of the above-mentioned applications are hereby incorporated by reference for the purpose of describing the preferred embodiments of the present invention. The upper bowl member 24a includes a generally circular disc-shaped portion 36 which is connected to the central annular chamber 3.
0 and extends outwardly and downwardly from the portion of the upper bowl member 24a that forms the upper bowl member 24a.

A molded ring-shaped member 38 is suitably removably attached to the lower end of the conical disc-shaped portion 36. or,
The ring-shaped member 38 has an inner surface which, together with the inner surface of the conical disc-shaped portion 36, provides a smooth continuous internal curve of the bowl and which extends in a plane transverse to the vertical axis of the shaft 14 (FIG. 2). ) has a lower edge 40 (see FIG. 2). Lower bowl member 24b also has a generally conical lower disk portion 42 that extends outwardly and upwardly from the portion of lower bowl member 24b that defines acceleration chamber 26. A molded ring member 44 is movably supported at its outer end by a lower disc portion 42 for controlled back and forth movement relative to the ring member 38. The ring member 44 has an inner surface which, together with the inner surface of the lower disc portion 42, provides a smooth continuous interior curve of the bowl, and has an upper edge 46 extending in a plane extending parallel to the lower edge 40. ing. The ring member 44 has mechanisms 48 provided at appropriate distances in the circumferential direction.
, the ring-shaped member 38 is appropriately and selectively moved toward or away from the ring-shaped member 38. Only one of them is illustrated in FIG. A particular mechanism 48 for controlling the movement of the ring member 44 is disclosed in Japanese Patent Application Laid-open No. 53-11.
305m, the contents of which are incorporated herein by reference. In this specification, the term 1 radial direction is used with respect to the rotation axis XX, and the term 0 axis direction is used with respect to the rotation axis XX or an axis parallel thereto, and the term 0 is used above and below. etc. are used for convenience in the description related to FIG. Each mechanism 48 has a seal adapter 50 suitably rigidly secured to the radially outer portion of the lower disk portion 42 .

Preferably, the seal adapter 50 is a ring member common to all of the mechanisms 48 and includes a suitable number of integral guide pins 52. The guide pins 52 are uniformly circumferentially spaced and their centers are coaxial with axis X--X over a constant circumference. The piston assembly 54 is supported for relative axial movement by guide pins 52 each having a suitable spring 56. The spring 56 is disposed between the seal adapter 50 and the piston assembly 54 and biases the piston assembly 54 outwardly from the seal adapter 50. Each piston assembly 54 is suitably securely secured to the lower portion of the ring member 44 such that axial movement of the piston assembly 54 causes a corresponding axial movement of the ring member 44 within the restricted range of movement of the ring member 44. has been done. Piston assembly 54 has an inwardly extending circumferentially continuous flange portion 58 . The flange portion 58 overlies the radially continuous outer peripheral portion of the seal adapter 50 and forms a chamber 60 therebetween. This chamber 60 extends circumferentially around the lower disk portion 42 . Hollow annular flexible control member 62
is disposed within the chamber 60 and has a shape that allows it to be inserted tightly into the chamber. A suitable number of tubular supply passageways 64 are in fluid communication with the interior of the control member 62 and radially inwardly and downwardly of the chamber 60 through the seal adapter 50 along the exterior surface of the lower bowl member 24b. and is aligned with the open end of a supply passage 65 which extends through the lower portion of the lower bowl member 24b and extends from the exterior of the shaft 14 toward the center thereof, such that the supply passage extends coaxially downwardly within the shaft 14. and is mated to a suitable airflow control device 66 mounted on the lower end of the shaft.
This airflow control device 66 includes a controllable supply passage 68 . Although any suitable fluid may be utilized to pressurize chamber 60, pressurized air is preferred for reasons such as availability, controllability, and minimal inertial effects. For these reasons,
Air is included as the working fluid for control member 62 in this embodiment. Control device 66 may be of any suitable type capable of controlling air as described herein. Appropriate fittings, known in the art, may be used between these parts of the air supply system. A suitable circumferentially continuous flexible seal 70 is used to prevent material within bowl 24 from entering chamber 60 during movement of ring member 44 above seal adapter 50; One end is secured between the seal adapter 50 and the lower disk portion 42, and the other end is secured between the top of the piston assembly 54 and the bottom surface of the ring member 44. A suitable exhaust hole 63 is provided in the piston assembly 54 communicating with the atmosphere, either in the chamber 60 or in the flexible seal 70.
Appropriately prevents the air pressure below from increasing. Although the principles of the invention can be used to make various types of centrifuges,
The preferred embodiment illustrated is designed for use in the dewatering of scrap metal, etc., as is commonly used in backfilling performed in mining operations. Accordingly, the present invention will be described in relation to such quartzite. The main object of the present invention is to continuously discharge waste minerals from the centrifuge of the present invention. In order to perform such continuous discharge from the input scrap mineral slurry, the rotating bowl 24 of the centrifuge is used.
There is a need to create a relatively impermeable beach zone within the area, as discussed below. Such a beach zone, as described above, involves loading the slurry into the centrifuge and moving the centrifuge below its normal operating speed with the discharge gap 34 between the lower edge 40 and the upper edge 46 of the outer bowl periphery closed. is also slow, typically 400 to 600r. p. This is achieved by rotating by m. The spring 56 is the release gap 3
The ring member 44 is inserted into the ring-shaped member 38 so that the ring member 4 is normally open.
biased away from The discharge gap 34 is closed and maintained by controllably admitting pressurized air from a source through the supply passages 68, 65, 64 into the interior of the control member 62. With the ring member 44 attached,
A suitable supply pressure of pressurized air causes the control member 62 to expand within the chamber 60, thereby causing the piston assembly 54 to move into positive engagement with either the upper edge 46 or the lower edge 40. Such air is supplied at a pressure to overcome the bias of the spring 56 and provide the necessary contact pressure between the lower and upper edges 40, 46 of the chamber 60 surrounding the control member 62.
The air inside is discharged into the atmosphere through the exhaust hole 63 by the expansion of the control member 62. When the discharge gap 34 is closed, the solids of the input and rotating slurry are separated by centrifugal force and collected at the radially outermost end of the interior of the bowl 24. The liquid portion of the slurry is discharged through the outlet 32 and then in a suitable manner, e.g. via a channel (not shown).
The collected liquid is then disposed of by discharging it into a tank and pumping the collected liquid to the desired location. This liquid fraction is preferably transported to the surface to form a subsequent slurry. The loading of the slurry and the rotation of the centrifuge are such that the formation of solid particles results in a constant depth and concentration radially inward from the discharge gap 34 such that the discharge gap 34 can be opened without discharging the deposited solids. It continues until it has. Such accumulated solids occupy a large portion of the bowl 24;
A generally cylindrical shaped interface 74 is defined radially outwardly spaced from the shaft 14 . This interface 74 becomes the inner surface of the beach zone. By operating the centrifuge in this manner, the beach zone interface 74 is located radially outward of the acceleration chamber, and furthermore, the interface 74 of the beach zone is located at a position radially outward of the acceleration chamber, and furthermore, the interface 74 of the beach zone is located approximately perpendicularly between the inner surfaces of the conical disk portion 38 and the lower disk portion 42. Extending. To continuously discharge such deposited solids, the discharge gap 34 is opened to the desired width and the operating speed of the centrifuge is increased to such a speed that the deposited solids begin to discharge through the discharge gap 3''4. .

The speed at which such release begins is hereinafter referred to as the critical speed. This speed is 100 to 300 rpm higher than the speed used to create the beach zone. The discharge gap 34 is opened by reducing the air pressure in the control member 62 by appropriate operation of the airflow control device 66. The critical speed is not necessarily the operating speed of the centrifuge. In order to continuously release the accumulated solids from the slurry containing a large amount of solids, the flow rate is 1,400 to 2,500 rpm. p. A centrifugal speed of m is sufficient. At such operating speeds, three distinct zones of action are created within the bowl 24 (see FIG. 6). One of them is a separation zone 76 that extends annularly around the shaft 14 and forms a flow path for the slurry.
Effluent is discharged through 2. Another is a beach zone extending from the separation zone 76 to the discharge zone and having an interface 74, and yet another is between and adjacent each face of the lower and upper edges 40 and 46 with a radius a discharge zone extending in the direction. As the incoming slurry enters the separation zone 76, its solid particles move in the radial direction of the separation zone 76 relative to the general direction of the fluid due to their high relative density compared to the transport medium liquid. and is deposited in the radial innermost part of the beach zone. The beach zone acts as a collection chamber for such accumulated solids and isolates the discharge zone from the separation zone. This allows the separation process to be accomplished independently of the solids release. Since the separation and discharge are isolated, the centrifuge can be operated in conjunction with the separation process requirements provided the required solids discharge takes place. This discharge zone is thus adjustable in the present invention to provide the solids discharge required for the desired separation process. By operating the centrifuge in conjunction with the separation process requirements, the smallest solid particles are deposited in the beach zone and clean water is discharged through the outlet 32, thus removing all of the solids content of the slurry. Used for release. As will be discussed below, there are a number of interrelated factors that contribute to solids deposition; was found to be practical. Since the centrifuge is operated in conjunction with the separation process, the rate at which solid particles are deposited in the beach zone determines the rate at which the deposited solids must be discharged.

The discharge gap 34 therefore needs to be of a shape that releases the sediment at a predetermined rate, ie, a rate equal to the rate at which solids are deposited in the beach zone. Releasing sediment at a rate higher than the rate at which solids are deposited will remove the beach zone within a period of time. If the ejection rate is lower than the deposition rate, the beach zone interface 74 shifts (radially) in the direction of the shaft 14 and the separation zone 76
The volume of the separation zone is reduced and this reduction causes more solids to be included in the effluent due to the faster water flow through the separation zone caused by the reduction in the volume of the separation zone.
The centrifuge of the present invention allows for some radial movement of interface 74 without adversely affecting the operation of the centrifuge. The distance that the separation zone 76 and beach zone interface, ie, the interface 74, can be radially moved is defined by the radius of the interface 74, hereinafter referred to as the plowout radius.

With this plowout radius, the beach zone cannot be maintained. This is because the volume of deposited solids is not sufficient to provide the hydrostatic pressure applied to the beach zone. The radius of the interface 74, hereinafter referred to as the scour radius, also defines the distance over which said interface 74 travels in the radial direction. Below this washout radius, the deposited solids at the beach zone interface enter the separation zone, and all of this deposited solids mix with the water and are discharged through the outlet 32. Alternatively, some solid particles of the injected slurry may be discharged through the outlet 32 without being deposited in the beach zone. The plowout radius is greater than the scour radius, so the interface 74 can be safely shifted radially between a radius slightly smaller than the prow radius and a radius slightly larger than the scour radius. The rate of solids deposition in centrifuges of the disclosed type depends on a variety of factors.

The main factors include the speed of the centrifuge, the characteristics of the solids content of the slurry when subjected to centrifugal force, the characteristics of the slurry as it enters the centrifuge, and the solids content of the slurry. be. Although the speed of the centrifuge can be controlled, other factors vary substantially with various backfill operations. Therefore, it is difficult to control the solids deposition rate. For a given backfill operation, where the kombu ore is produced in a uniform manner and the amount of transport water and transport system are known for a particular location, the rate of solids deposition can be broadly controlled. However, because vibrator systems and locations vary, predetermining solids deposition rates is impractical except at specific mining locations. Thus, in the present invention, the balance required for continuous operation is achieved by controlling the rate at which accumulated solids are released. Release rate is determined by various factors. The main ones are the centrifuge speed, the size and shape of the discharge opening (discharge gap), the characteristics of the discharged material, and the manner in which the sediment flows through the beach zone. An important aspect of the present invention is to provide a bowl 24 with an internal surface shaped to control the flow of sediment through the beach zone so that discharge occurs at a constant rate. Since the fluid resistance of deposited solid particles depends on the fluid properties of the material, the hydrostatic and centrifugal forces exerted on the beach zone, the shape of the bowl is a function of the specific material in the beach zone and the operating conditions of the centrifuge. Related selection. Furthermore, the shape of the bowl is determined by the control functions provided to the bowl 24.

Therefore, the initial slope of the inner surface of the bowl 24 radially outward at the interface 74 is such that the rate of solids deposition matches the rate at which the deposit moves outwardly from the shaft 14 in that initial region. selected. The final slope of the interior surface of the bowl 24 determines the rate of deposit discharge and the manner in which the deposit flows into the discharge gap 34. Bowl 24 between initial and final slope
The slope at the intermediate or transitional part of the inner surface of the tube accepts material from the initial slope and is controlled to provide as much material as is needed at the discharge section. As a result, the internal geometry of the bowl 24 for a given material and centrifuge operation provides a given resistance to material flow, providing uniform and controlled mass transfer through the beach zone. The terms ``uniform flow'' and ``controlled flow'' do not mean moving deposited particles in a precise pattern or manner within the beach zone, but do mean that individual particles move quite differently. 3, the inner surface of the bowl 24 has various slopes.Bowl 2
The slope of 4 is the axis of rotation X- which provides a higher resistance to the flow of the material as the centrifugal force acting on the material increases.
It increases in relation to the increase in radius from X. Such a shape provides optimum flow resistance for the entire radius of the beach zone of the bowl 24, effectively mirroring the inner surfaces of the upper and lower bowl members 24a, 24b. As shown, the inner surface of the lower bowl member 24b expands radially at an angle θ1 at the radially inner surface adjacent the acceleration chamber 26 and then radially expands at the radially outer portion adjacent the discharge gap 34. It is enlarged at an angle of θ2. The intermediate surface portion of the lower bowl member 24b expands radially between its innermost and outermost portions along a curved path, so that each successively larger bowl of the surface of the lower bowl member 24b , each increasing angle in the radial direction is such that the internal shape of the bowl 24 forms a concave surface. As the surface angle increases in the radial direction of the bowl with a gradually increasing radius, the flow resistance for each of the material elements of the beach zone gradually increases as each material particle of the beach zone flows radially outward. ．． do. This compensates for the increase in centrifugal force for solids loads at such increasing radii and establishes and maintains uniform movement of solid particles through the beach zone. The angle of the bowl surface shape with respect to the radial direction is internal! There is no need for a continuous increase in the outward direction.

For example, the surface shape in Figure 4 consists of a plurality of adjacent straight parts, each of which has a radius of θ4,
5, forming an angle of θ6. Other examples are also available in which the bowl radius increases gradually and the surface profile angle increases gradually. In a centrifuge used for dewatering a mortar slurry, angles of 0 and 13112 degrees are preferred.

However, this angle θ1 can be changed within a certain range depending on the conditions when designing the centrifuge. Changing the angle 01 changes the particle flow velocity within the beach zone. Angle 01 is therefore selected to provide uniform flow at the largest cross section of discharge gap 34. For such centrifuges, an angle θ2 of 45 degrees has been proven to be fully satisfactory.

However, the angle θ2 can also be changed if necessary. This is an angle of 0
1 or may be changed independently. In short, it is sufficient that the flow of the solid particles is uniform and that the cross section of the release gap 34 is maximum. Another important aspect of the dimensions of the bowl is the height to depth ratio h/d of the separation chamber, as shown in the left half of bowl 14 in FIG.

Generally, if this ratio is small, the beach zone will be more stable than if it is large. For example, if the ratio is large, i.e., h is large and d is small, the beach zone becomes unstable and relatively small changes in the centrifuge, such as bowl rotation speed, feed concentration, feed rate, etc., prevent uniform beach flow. It will be done. This is done, for example, in such a way that it promotes a tendency for the beach flow velocity to increase towards the axial center of the beach zone. Critically, such disruption of uniform flow results in non-uniform percolation of the effluent.
cOlatiOn) occurs, destroying the uniformity of the interface 74 and causing beach plow-out as described above. Or it will collapse. The optimal h/d ratio is highly dependent on other parameters of the system. In particular, it depends on the physical properties of the substances to be separated. For centrifuges used to process solid content concentrated slurries of kombu ore, the optimum value is between 0.75 and 1. In particular, a range of 0.9 to 1.2 is preferable. The configured bowl 24 shape, in conjunction with the input slurry and operating speed, provides the necessary balance between the discharge gap 3 and the continuous operation.
This can be obtained by changing the width of 4. Therefore, after the beach zone has been established and the operating speed has been established, the control member 62 is depressurized by discharging compressed air to the outside by means of the airflow control device 66. The width of the discharge gap 34 is adjustable through axial movement of the ring member 44 by varying the air pressure within the control member 62. Therefore, the ejection gap 34 is kept constant in width such that the deposition rate and the ejection rate are the same. If the operating parameters change during centrifuge operation,
The discharge gap 34 can be varied by applying pressure to or removing pressure from the control member 62 to maintain the same velocity. Operating parameters include slurry feed rate or slurry solids content. For example, if the feed rate suddenly drops below the operating level, less solids will be deposited at the beach interface 74. Further, to maintain this interface 74 within an acceptable radial distance, the ejection rate is reduced by increasing the inflatable seal pressure and reducing the width of the ejection gap 34. Conversely, if the release rate needs to be increased, the sealing pressure is reduced. This widens the discharge gap 34. The function of control member 62 is to move ring member 44 through piston assembly 54, and therefore control member 62 and chamber 60 may be of any shape to effectuate such operation. Although a continuous circumferential discharge gap 34 is preferred as described above, other shapes may be used if desired.

Another discharge gap is illustrated in FIG. The ring member 44 is provided with a separate integrally or rigidly fixed member, which is an upwardly projecting angular block member 15 which is adjacent to the aforementioned discharge gap. radially outwardly, and the block members 15 are uniformly shaped and uniformly circumferentially spaced, defining slots 17 of uniform width and height between the blocks; Sediments are released through the
In such a structure, the cross-sectional area of the ejection opening is reduced and therefore the amount of emitted substance is also reduced. Such a low release rate is
Desirable if the solids content of the inlet slurry is not particularly high. In this variant, the circumference of the slot 17 is approximately the same as the circumference of the individual block members 15. Housing 1
0 is a circular inner wall member 21 that is spaced apart from each other in the radial direction.
It is equipped with 21.

The material from the centrifuge is used in this double annular inner wall member 21, 2.
1 and in any suitable manner one or more suitable lowermost outlets 23 (that is, internal wall members 2
(which communicates with the ring between 1 and 2). The radially outermost wall member 21 forms, in conjunction with the wall of the housing 10, an annular chamber 25 and receives discharged water from the outlet 32. The annular chamber 25 has one or more outlets 33 to effect drainage in the desired manner. Ring-shaped member 38
The ring member 44 is worn away by the emitted substances. Therefore, they are becoming replaceable. If necessary, these ring members can be formed in suitable locations to allow their replacement. Additionally, suitable intake means 27 are provided to add cement to the material discharged from the centrifuge to provide a material such as that described in Japanese Patent Application No. 53-13057. Since the centrifuge described above has a rotating element, such rotating element rotates coaxially about the axis X--X. Also, such rotating elements are arranged radially to prevent unbalanced rotational forces from being generated within the centrifuge. Thus, the present invention provides a centrifuge and method of operating the same. A centrifuge zone is isolated from its discharge zone and solid particles are continuously removed from the continuous flow of input slurry. Accordingly, centrifuges are designed taking into account the physical conditions for centrifuging such particles. This isolation is achieved by retaining and controlling the continuous movement of deposited particles over a period of time through a zone, called the beach zone, between the separation and release zones. Note that this control is
The forces on the deposited particles are applied in such a way that their movement through the emission zone is not adversely affected. Hydrostatic pressure on the interface between the separation zone and the beach zone moves sediment particles through the beach zone.

The beach zone is constructed to withstand the pressure gradient between the interface and the discharge zone as described above. Furthermore, the hydrostatic pressure of the water content of the input slurry is high enough to allow a critical amount of water to percolate through the beach zone. This results in the above-described flow of deposited particles. The flow of sediment material in the beach zone is controlled by the internal surface geometry of the separation bowl of the centrifuge. This shape can be changed while retaining its control function. The present invention
Also, by significantly varying the solids particle content in weight percent of the input slurry, approximately the same concentration of material can be delivered. In the case of a waste mineral slurry, its solid particle content is between 30 and 7% by volume and is processed to give approximately the same emitted material. The centrifuge of the present invention is flexible in relation to the variable operating parameters of the centrifuge. This flexibility is achieved by providing a positionable interface in radial position and material release that can be varied over a wide range. Therefore, for a given discharge aperture, the operating parameters can be varied by performing a radial movement of the interface. Conversely, for a given radial position of the interface, changes in the operating parameters can be achieved by changing the cross-section of the ejection aperture. If the radial position of the interface and the cross-sectional opening of the discharge gap are effected by the same parameters of the centrifuge, then in the centrifuge of the invention the interface moves radially or the discharge gap cross-sectionally , and its continuity adapts to all changes in such parameters. Although a preferred embodiment and certain variations of the invention have been described, various modifications are possible within the spirit of the invention.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a centrifuge constructed according to the principles of the present invention, FIG. 2 is an enlarged cross-sectional view of the outer periphery of the rotating part of the centrifuge shown in FIG. 1, and FIG. is an enlarged view of the internal shape of the centrifuge bowl of FIG. 1; FIG. 4 is a schematic view similar to FIG. 3 of another internal configuration of the centrifuge bowl according to another embodiment of the invention; 5 is a perspective view of an alternative configuration of the ring member of the discharge section of the centrifuge shown in FIG. 1, and FIG. 6 is a schematic representation of the various zones within the bowl of the separator shown in FIG. It is. 10...Housing, 14...Shaft,
20...Central passage, 22...Feed pipe, 24...
...bowl, 26...acceleration chamber, 28...
...Exit, 30...Central ring chamber, 3
2... Outlet, 24a... Upper bowl member, 2
4b...Lower bowl member, 36...Conical disc-shaped part, 38...Ring-shaped member, 40...
...Lower edge, 46...Upper edge, 50...
Seal adapter, 54... Zeston assembly, 6
0... Chamber, 62... Control member, 66... Air flow control device, 68... Supply passage, 70... Flexible seal, 76 ...Separation zone.

Claims (1)

Claims: 1. (a) an extended shaft rotatable about its central longitudinal axis; and (b) rotatably carried by and axially positionable with respect to the shaft. (c) a pair of bowl members defining a centrifugation chamber; a method for operating a centrifuge having means for continuously rotating the bowl members with peripheral portions of the bowl members radially outward of the central axis continuously engaging each other; During the initial period during which the slurry is continuously flowed into the interior of the bowl member, the portion of the slurry that is continuously flowed into the interior of the bowl member is separated into a solids component consisting primarily of solid particulate solids, where the solids are increasing radially relative to the central axis over the initial period until the solid material extends from within the engaged periphery of the member to a radially outwardly adjacent portion of the shaft; a portion of the solid material adjacent to the shaft member that axially surrounds the entire length of the shaft within the shaft member and extends axially to a radial percentage that is substantially less than a maximum radial percentage of the solid material; It defines the road, and along with that,
over the initial period, separating a portion of the incoming slurry into an effluent component consisting primarily of the fluid medium;
A portion of the effluent component is discharged from one axial end of the flow path to the exterior of the bowl member such that the periphery of the bowl member is aligned with respect to the central axis for a subsequent period of time. While continuing rotation of the bowl members in an axially spaced condition, incremental solids components are added to the solids to maintain a substantially uniform radial proportion of the solids over the duration. at a speed that simultaneously separates a portion of the additional slurry that is continuously flowed into the interior of the bowl member into a solids component and an effluent component, while discharging a portion of the solids to the exterior of the bowl member and concomitantly , continuously discharging a portion of said effluent component of additional slurry from one axial end of said flow path for said duration. . 2. A method according to claim 1, characterized in that the discharge of the solids is continuous. 3. A method according to claim 1, characterized in that the discharge of the solids takes place through the radially outermost end of the bowl member. 4. A method as claimed in claim 1, characterized in that the discharge of solids takes place at the radially outermost edge of the continuous periphery of the bowl member. 5. The method of claim 1, wherein the flow of deposited solid particles through the outermost end of the bowl member is uniform. 6. The method of claim 1, wherein the release rate is variable. 7. A method according to claim 4, characterized in that the discharge of the solids takes place in a variable section at the outermost end of the bowl member. 8. A method according to claim 3, characterized in that during said solids deposition, solids of previously deposited particles flow towards said outermost end at a controlled rate. 9. The method of claim 8, wherein the continuous flow slows down with increasing radial distance from the axis. 10 The position of the interface between the deposited particles and the flow path is
2. A method as claimed in claim 1, characterized in that during the centrifugal deposition period the velocity is moved in a radial direction in order to keep the velocity constant. 11 a housing; an elongated shaft rotatably supported by the housing and rotating about its central longitudinal axis; and an elongated shaft rotatably carried by the shaft and axially positionable with respect to the shaft. a pair of bowl members defining a centrifugation chamber and having a peripheral portion spaced radially outwardly from the central axis; passage means for supplying a slurry of solid particles and continuously discharging effluent from said centrifugation chamber; and rotating said shaft, thereby dividing the slurry supplied to said centrifugation chamber into solids and effluent components. and an axial direction carried by at least one of said members such that peripheral portions of said bowl members successively engage each other to deposit said solids component in said centrifugation chamber. and at least one axial position such that the peripheral portions are axially spaced apart from each other such that the deposited solids components can be discharged from the centrifugation chamber during a period of time. and means for selectively axially moving at least one of said bowl members, said bowl member having an internal configuration such that said volume of said deposited solids component remains substantially constant during said period of time. A centrifuge comprising: 12. Claim 12, characterized in that the internal shape of the bowl members is curved, each forming a gradually increasing bowl radius, the radius increasing with the central radial axis of the bowl member. The centrifuge according to item 11. 13. The internal shape of the bowl member is comprised of a plurality of continuous straight sections, the straight sections forming an angle with respect to the central radial axis of the bowl member, and the radius of the bowl gradually increasing. Claim 11:
The centrifuge described in section. 14. The centrifuge according to claim 11, wherein the bowl member has an upper bowl member and a lower bowl member, the shapes of which are mirror images.