SEPARATOR

Description

[0001] The invention relates to a self-emptying separator for the centrifugal separation of a suspension S into at least one light liquid phase LP, one heavy solid phase SP and one medium-heavy intermediate phase IP, which has a centrifugal drum rotatable about a rotational axis D according to the preamble of claim 1 and a method according to claim 17.

[0002] In addition to one or more continuous outlets for one or more liquid phases, generic discontinuous self-draining separators have a drain system with a piston valve that can be moved alternately into an open and a closed position by a fluid, particularly with liquid as the fluid. The piston valve opens (open position) and closes (closed position) one or more solids discharge openings in the drum wall. In the open position, a solid phase is ejected from the centrifuge drum and thus removed from the drum. In the closed position, the solids discharge openings are closed, preventing this from happening.

[0003] To ensure precise operation of such a drum emptying system with a piston valve, it can have a fluid supply and discharge system to control the movement of the piston valve into the closed and open positions. This in turn can be equipped with one or more valves. The valve(s) serve to fill a control chamber on the piston valve with fluid - a liquid or a gas - and it serves to drain fluid from a chamber on the piston valve for the emptying of solids, so that the piston valve can move to another position. For example, in a separator with a vertical axis of rotation, fluid can escape below a piston valve so that the product in the drum pushes the piston valve vertically downwards after the fluid has been drained.The valve for filling the control chamber is also called the control water valve, while the valve for emptying the control chamber is also called the piston valve due to its preferred design.

[0004] DE 26 09 663 discloses a separator with a drum in which the separated heavy phase (concentrate) is directly discharged from the solids chamber via individual piston valves distributed around the circumference. The piston valves are controlled, i.e., closed or opened, via a common ring valve.

[0005] During the centrifugal processing of a product in three phases, an incoming suspension is separated in the drum into a lighter or less dense liquid phase, a medium-heavy or medium-dense intermediate phase that is usually still flowable, and a heavier (possibly also still flowable) or denser solid phase.

[0006] According to the state of the art, the intermediate phase is discharged, for example, via another continuous liquid discharge device, such as a paring disc or similar device. Alternatively, the intermediate phase can be discharged together with the solids during emptying.

[0007] EP 2 348 894 B2, for example, discloses a separator with a drum in which the light phase is removed via a gripper or a peeling disc, the heavier solid phase via a piston valve, and the intermediate phase via a separating disc and another gripper or a peeling disc. However, the intermediate phase is continuously removed. If necessary, the intermediate phase discharge is recirculated into the inlet.

[0008] A key problem with state-of-the-art solutions is that the intermediate phase is only discharged continuously and often cannot be discharged without loss or with minimal loss. "Loss-free" in this context means that the discharged intermediate phase contains no portion of the light and / or heavy phase. "Low-loss" in this context means that the discharged intermediate phase contains only a small portion of the light and / or heavy phase.

[0009] US 10 6554 0050 B discloses a generic prior art! A self-emptying centrifugal drum is also known from DE 36 44 098 A1. The object of the invention is to advantageously implement a discharge of the intermediate phase with as little loss as possible.

[0010] The invention achieves this object by the subject matter of claim 1.

[0011] According to claim 1, a self-emptying separator is provided for the centrifugal separation of a suspension S into at least one light liquid phase LP, one heavy solid phase SP and one medium-heavy intermediate phase IP, which has at least the following: a) a centrifugal drum rotatable about a rotational axis, into which the suspension S to be processed can be introduced, b) at least one liquid discharge for the light liquid phase LP, c) at least one or more discontinuously acting solid discharge opening(s) for the heavy solid phase SP, to which at least one first controllable discharge device is assigned, with which the at least one or more solid discharge opening(s) can be discontinuously opened and closed again, and d) at least one or more discontinuously acting discharge opening(s) for the intermediate phase IP, to which at least one second controllable discharge device is assigned, with which the at least one or more discharge opening(s) for the intermediate phase IP can be discontinuously opened and closed again, e) wherein the second discharge device is controllable independently of the first discharge device,so that the discharge of the intermediate phase IP can take place independently of the discharge of the solid phase SP.

[0012] Thus, the second discharge device can be controlled independently of the first discharge device, so that the discharge of the intermediate phase IP is decoupled from the discharge of the solid phase SP. With the two independently controllable or "operating" discharge devices, it is advantageously possible to discharge the solid phase and the intermediate phase only at the exact time and to the exact extent required for centrifugal separation. In this way, one or more sensors can be used in advance to determine from the behavior of the drum when and for how long each phase should be discharged. This measurement is saved. Then, during operation, the appropriate time and duration for discharging the respective phase can be determined by comparing these measurements. All of this can be controlled by a control device. In particular, the intermediate phase can also be defined in this way and separated without loss or even completely.discharged with low loss through the second discharge device.

[0013] According to claim 1, it is further provided in terms of construction that nozzle-like pipes are placed on or in the discharge openings for the intermediate phase IP, the length of which is designed such that they extend radially up to a radius R3 into a layer of the intermediate phase IP which is radially formed in the centrifugal drum during rotation of the centrifugal drum, so that the discharge of the intermediate phase IP from the centrifugal drum takes place on the radius R3.

[0014] It should be noted that the light phase is the least dense phase, the medium-heavy phase is a phase with a relatively higher density, and the heavy phase is a phase with an even higher density.

[0015] According to a first preferred embodiment of the invention, the first discharge device has at least one fluidically, in particular hydraulically, or electrically (in particular electromechanically or electromagnetically) controllable, mechanically acting opening and closing means with which the at least one or more solids discharge opening(s) can be opened and closed, and the second discharge device has at least one fluidically, in particular hydraulically, or electrically controllable, mechanically acting opening and closing means with which the at least one or more discharge opening(s) for the intermediate phase IP can be opened and closed.

[0016] This design can be implemented in a variety of ways, which are explained below using examples.

[0017] Thus, according to a preferred embodiment of the invention, it can advantageously be provided that the mechanically acting opening and closing means of the first discharge device is a piston slide arranged in or on the outside of the centrifugal drum, in particular a hydraulically controllable piston slide, which can be moved into different positions in order to open the one or more solid discharge openings in an open position or to close them in a closed position.

[0018] However, in another preferred embodiment of the invention, it can also be advantageously provided that the mechanically acting opening and closing means of the first discharge device has at least one or more electrically or fluidically controllable valves, in particular piston valves, which are assigned to the respective solids discharge opening(s) in order to open them or to close them in a closed position.

[0019] It can further be provided that the mechanically acting opening and closing means of the second discharge device is a piston slide which is arranged on the outside of the centrifugal drum and is in particular hydraulically controllable and which can be moved into different positions in order to open the one or more discharge openings for the intermediate phase IP in an open position or to close them in a closed position, or it can be provided that the mechanically acting opening and closing means of the second discharge device has at least one or more electrically or fluidically controllable valves, in particular piston valves, which are assigned to the respective discharge opening(s) for the intermediate phase IP in order to open them or to close them in a closed position.

[0020] The following variants are particularly preferred because they are structurally simple to implement and can be operated simply and with low losses during operation: According to a preferred embodiment, the mechanically acting opening and closing means of the first discharge device is a piston slide valve arranged in the centrifugal drum, in particular a hydraulically controllable piston slide valve, and the mechanically acting opening and closing means of the second discharge device is a further piston slide valve arranged on the outside of the centrifugal drum, in particular a hydraulically controllable piston slide valve.

[0021] According to another preferred embodiment, the mechanically acting opening and closing means of the first discharge device is a piston slide arranged in the centrifugal drum, in particular a hydraulically controllable piston valve, and the mechanically acting opening and closing means of the second discharge device is at least one controllable piston valve which is assigned to the respective discharge openings for the intermediate phase IP in order to open them or to close them in a closed position.

[0022] According to a third preferred embodiment, the mechanically acting opening and closing means of the first discharge device has controllable piston valves which are assigned to the respective solids discharge openings in order to open them or to close them in a closed position, and the mechanically acting opening and closing means of the second discharge device has controllable piston valves which are assigned to the respective discharge openings for the intermediate phase IP in order to open them or to close them in a closed position.

[0023] Further advantageous designs and combinations of a piston slide and piston valves are conceivable.

[0024] The radius R3 is intended to be smaller than a radius R2, where the solid discharge openings are located, but larger than a radius R1, where the liquid phase LP is discharged. This advantageously results in a defined discharge of each phase, largely eliminating mixing with the other phases.

[0025] In a further embodiment of the invention, a paring disc can be assigned to the liquid discharge. However, the liquid discharge can also be implemented in other ways.

[0026] In a further embodiment of the invention, the discharged solid phase SP is expelled through the at least one solid discharge opening into a first annular space serving as a solids catcher. The first annular space is arranged in a hood-like housing and has a nozzle arranged radially on the first annular space for connecting a hose or line for further removal of the solid phase SP. This allows the solid phase SP to be removed in a structurally simple manner and thus advantageously independently of the intermediate phase IP.

[0027] In a further embodiment of the invention, the discharged intermediate phase IP passes through the at least one discharge opening into a further annular space arranged in the hood-like housing and having a nozzle arranged radially on the further annular space for connecting a hose or line for further discharge of the intermediate phase IP. This allows the intermediate phase IP to be discharged in a structurally simple manner and thus advantageously independently of the solid phase SP.

[0028] The problem is also solved by the method according to claim 17.

[0029] Further advantageous embodiments of the invention can be found in the remaining subclaims.

[0030] The invention is described in more detail below using exemplary embodiments with reference to the drawing.

[0031] It shows: Figures 1 - 3 each show sectional views of different variants of separators, each with a centrifugal drum and with components of an emptying mechanism of the centrifugal drum for a solid phase and for an intermediate phase.

[0032] The following description of the figures describes three embodiments.

[0033] Terms such as "top", "bottom", "right", "left", "outside" or "inside" refer to the respective position shown in the figures.

[0034] Fig. 1 shows a first separator with a rotatable centrifugal drum 1. The centrifugal drum 1 can have a vertical axis of rotation D. The centrifugal drum 1 can be enclosed by a hood-like housing 2 that does not move during operation of the centrifuge, i.e., is stationary. Other components such as a rotary drive or a control device are not shown.

[0035] The centrifugal drum 1 can preferably be designed to be single-conical and / or, as here, double-conical (bottom and / or top and especially inside). This shape promotes the collection of the separated solid phase in a defined area of ​​the drum. The centrifugal drum 1 is preferably designed for continuous operation, in which a continuously flowing suspension S is continuously centrifugally processed and separated into a light liquid phase LP, a medium-heavy intermediate phase IP, and a heavy solid phase SP. The centrifugal drum 1 can have a lower drum section 3 and an upper drum section 4. These drum sections 3, 4 can each be conical on the outside and / or inside and can be connected to one another in various ways, for example with a locking ring 5.

[0036] An inlet pipe 8 serves to supply a suspension S to be processed into the centrifugal drum 1.

[0037] The inlet pipe 8 can be designed as a stationary element that does not rotate during operation, as shown here. However, it can also be designed to rotate. Here, it extends concentrically to the rotational axis D into the centrifuge drum 1. Furthermore, it extends through the housing 2 above the centrifuge drum 1.

[0038] A distributor 6 for feeding the product into the drum and a disc stack 7 of separating discs can be arranged in the centrifugal drum 1. The separating discs 7 can be arranged on a distributor shaft of the distributor 6.

[0039] After Fig. 1 bis 3 In a preferred - but not mandatory - embodiment, the inlet pipe 8 projects from above into the centrifuge drum 1. However, it can also extend from below into the centrifuge drum 1 (not shown).

[0040] The centrifugal drum 1 has a liquid discharge 9 through which the light liquid phase LP can be discharged from the drum 1. The liquid discharge 9 is implemented here by a paring disc 11. However, it can be designed in a different way.

[0041] The liquid discharge 9 opens internally into an annular space 9', which in turn can open into a radial nozzle 9" provided for connecting a hose or a line for discharging the liquid phase LP.

[0042] The light liquid phase LP, which flows radially inward from the disc pack 7, flows into a paring disc chamber 10, which rotates with the centrifugal drum 1. A paring disc 11 is arranged in the paring disc chamber 10. This paring disc 11 is non-rotatable in the paring disc chamber 10, i.e., is arranged stationary. By the paring disc 11 – also referred to as a gripper – which operates as a centripetal pump, the liquid phase LP is diverted from the centrifugal field forming in the operating centrifugal drum 1 over a radius R1 and guided or directed out of the centrifugal drum 1 via the liquid discharge 9, the annular space 9', and the nozzle 9". The discharge of the liquid phase LP thus takes place continuously.

[0043] For discharging a heavy solid phase SP, a fluidically and / or electrically - here fluidically - controllable and mechanically acting opening and closing means is provided, which here is designed as an - inner - piston slide 12 arranged in the centrifugal drum 1.

[0044] The inner piston valve 12 is provided for opening and closing at least one solids discharge opening 13. Preferably, several of the solids discharge openings 13 can be circumferentially distributed in the region of the largest diameter—on a radius R2—of the centrifugal drum 1. The discharged solid phase SP passes through the solids discharge openings 13 into a first solids trap-like annular space 14, which is arranged in the housing 2 and can have a nozzle 14' arranged radially on the first annular space 14 for connecting a hose or a line for further removal of the solid phase SP.

[0045] For discharging the solid phase SP, a first discharge device 15 is provided, which comprises a mechanically acting opening and closing means that can be fluidly actuated by actuators to carry out opening and closing movements.

[0046] For this purpose, the first discharge device 15 can comprise an injection chamber 16 for opening fluid and an injection chamber 17 for closing fluid, to which a fluid, in particular water, for activating the opening and closing movements of the inner piston slide 12 can be supplied via an opening fluid supply 18 and a closing fluid supply 19, in which a first opening fluid valve V1 and a first closing fluid valve V2 are arranged.

[0047] The closing process of the solids discharge openings 13, i.e., in this case, a lifting of the inner piston valve 12, can be accomplished by closing fluid, which is injected into a chamber below the inner piston valve 12. The closing fluid is metered via the closing fluid valve V2. The chamber is connected to piston valves 20, which are arranged in the wall of the centrifugal drum 1 in such a way that they can be closed by the centrifugal force prevailing in the centrifugal drum 1 when in operation.

[0048] The opening process of the solids discharge openings 13, i.e., the lowering of the inner piston slide 12, is carried out by opening fluid, which opens the piston valves 20, which in turn allows the closing fluid to escape from the chamber below the inner piston slide 12. For this purpose, a small amount of opening fluid is briefly fed through a supply line via an opening fluid injection chamber 16 into connecting lines in the drum base 3. The opening fluid ensures the buildup of all-round fluid pressure, which moves a closing piston against the centrifugal force in a radial direction toward the rotational axis D, thus opening the piston valve 20 of the centrifugal drum 1.

[0049] The opening fluid is dosed via the opening fluid valve V1.

[0050] Through the opened piston valves 20, the closing fluid escapes into a second annular space 21, which is arranged in the housing 2 and can have a nozzle 21' arranged radially on the second annular space 21 for connecting a hose or a line for further discharge of the fluid.

[0051] To discharge an intermediate phase IP, a further electrically or fluidically controlled and mechanically acting opening and closing device is provided. This is Fig. 1 as an outer and thus second piston slide 22 arranged on the outside of the centrifugal drum 1.

[0052] This can advantageously be designed as shown below. However, it can also be implemented differently.

[0053] The outer, second piston slide 22 is arranged below the centrifuge drum 1 on its outer side. The piston slide 22 is intended to close or open the discharge openings 25 so that the intermediate phase IP can be discharged from the discharge openings 25. For this purpose, the piston slide 22 is movable in the axial direction. The piston slide 22 is movably guided in a support ring 22'. To enable the piston slide 22 to move in the axial direction, the support ring 22' has lines 27, 28, and possibly an overflow bore 32, which can be supplied with opening or closing fluid as required, which will be described in more detail below.

[0054] The intermediate phase IP can be discharged through nozzle-like pipes 23, which are mounted in bores in the inner piston valve 12 distributed around the circumference and whose length is adjusted so that it extends into the layer of the intermediate phase IP that forms during rotation of the centrifugal drum 1, which is characterized here by a radius R3. Via corresponding, axially extending bores 24 in a wall of the drum base 3, the intermediate phase IP reaches at least one, preferably several, discharge openings 25 distributed around the circumference of the centrifugal drum 1, which can be closed or opened by the outer piston valve 22.

[0055] The radius R3 is smaller than a larger radius R2 on which the inlets of the heavy solids discharge openings 13 are arranged, but larger than the radius R1 on which the light liquid phase LP is discharged by the paring disc 11.

[0056] For discharging the intermediate phase IP, a discontinuously operating second discharge device 26 is provided, which comprises the mechanical opening and closing means, which can be fluidically actuated by actuators to carry out opening and closing movements.

[0057] For this purpose, the second discharge device 26 comprises an injection line 27 for opening fluid and an injection line 28 for closing fluid, to which fluid, in particular water, for activating the opening and closing movements can be supplied via an opening fluid supply 29 and a closing fluid supply 30, in which a second opening fluid valve V3 and a second closing fluid valve V4 are arranged.

[0058] Several piston valves 31 are provided, each of which serves or is used for a controlled discharge of the fluid used to carry out the opening and closing movements of the outer piston slide 22.

[0059] The closing process, i.e. the lifting of the outer piston slide 22, is carried out here by a closing fluid that is sprayed into a chamber in the support ring 22' below the outer piston slide 22. The closing fluid is metered via a second closing fluid valve V4. The chamber in the support ring 22' of the outer piston slide 22 optionally has the overflow bore 32 so that the maximum fill quantity of this chamber (and thus the maximum closing force of the outer piston slide 22) can be defined. The chamber is connected to the piston valves 31, which are arranged in a wall of the outer piston slide 22, which rotates with the centrifuge drum 1, in such a way that they are closed by the centrifugal force prevailing in the centrifuge drum 1 when it is in operation.

[0060] The opening process, i.e., the lowering of the outer piston slide 22, is effected by an opening fluid that opens the piston valves 31, which in turn allows the closing fluid beneath the outer piston slide 22 to escape from the chamber. The opening fluid is metered via a corresponding second opening fluid valve V3. A third annular space 33 is assigned to the discharge openings 25 in the wall of the centrifuge drum 1 for the intermediate phase IP, so that the intermediate phase IP is discharged separately. The third annular space 33 can have a nozzle 33' arranged radially on the third annular space 33 for connecting a hose or a line for further discharge of the intermediate phase IP.

[0061] The closing fluid escapes through the piston valves 31 into a fourth annular space 34, which is arranged in the housing 2 and can have a nozzle 34' arranged radially on the fourth annular space 34 for connecting a hose or a line for further discharge of the fluid.

[0062] It is after Fig. 1 - here by the second piston valve 22 - it is advantageously possible to discharge the intermediate phase IP from the centrifuge drum 1 in a defined manner and with very low losses. The separate, second discharge device 26, which can be controlled independently of the first discharge device 15, advantageously completely decouples the discharge of the intermediate phase IP by the outer piston valve 22 from the discharge of the solid phase SP by the inner piston valve 12. As a result, the intermediate phase IP can be discharged from the centrifuge drum 1 independently of the solid phase SP.

[0063] The actuation of the inner piston slide 12 and the actuation of the outer piston slide 22 can be controlled independently of each other by a control unit (not shown here). The control unit can also be a central control unit for controlling the separator, which, in addition to controlling the two piston slides 12, 22, is also intended for other control and / or regulation tasks of the centrifuge.

[0064] In Fig. 2 Another separator is shown. The basic structure is largely the same as the separator of the Fig. 1 . The following mainly describes deviations and / or additions to the design variant of the Fig. 1 described.

[0065] The discharge of the solid phase SP takes place after Fig. 2 as in the version according to Fig. 1 with an internal piston slide 12. A first opening fluid valve V5 is provided to supply opening fluid and a first closing fluid valve V6 is provided to supply closing fluid.

[0066] In contrast to the design variant of the centrifuge according to Fig. 1 shows the design variant of the centrifuge Fig. 2 but no outer piston slide 22.

[0067] The discharge of the intermediate phase IP takes place according to the design variant of the Fig. 2 First, again, through nozzle-like pipes 23, which are mounted in initially radially extending bores in the inner piston slide 12, which merge into or correspond with axial bores 24 in the drum base 3, and whose length is adjusted so that they extend into the layer of the intermediate phase IP that forms upon rotation of the centrifugal drum 1, here characterized by a radius R3. The radius R3 is smaller than the radius R2, on which the solids discharge openings 13 are arranged, but larger than the radius R1, on which the liquid phase LP is discharged by the paring disc 11.

[0068] For discharging the intermediate phase IP, a discontinuously controllable, second discharge device 26 is provided with a mechanically acting opening and closing means, which in this case has a plurality of piston valves 35. Via the corresponding, axially extending bores 24 in a wall of the drum base 3, the intermediate phase IP reaches several discharge openings 25 distributed around the circumference of the centrifuge drum 1, each of which can be closed or opened by one of the piston valves 35. The piston valves 35 can be arranged in the wall of the drum base 3 of the centrifuge drum 1 such that the discharge openings 25 are closed by centrifugal force during operation. However, they can be opened by hydraulic control with a control fluid.

[0069] The second discharge device 26 further comprises an opening fluid supply 36, via which control fluid can be supplied to the piston valves 35. The control fluid can open the piston valves 35 when the intermediate phase IP is to be discharged from the centrifuge drum 1. The opening time of the piston valves 35 can be adjusted via the supply duration of the supplied opening fluid. The opening fluid is metered via a corresponding opening fluid valve V7.

[0070] The discharge openings 25 for the intermediate phase IP open into a second annular space 37, so that both the solid phase SP and the intermediate phase IP can be discharged separately. The annular space 37 is arranged in the housing 2 and can have a nozzle 37' arranged radially on this annular space 37 for connecting a hose or a line for further discharge of the intermediate phase IP.

[0071] Even after Fig. 2 it is possible - here by means of the hydraulically controlled piston valves 35 - to discharge the intermediate phase IP from the centrifugal drum 1 in a defined manner and with very little loss.

[0072] Thanks to the second discharge device 26, which is also separate here and can be controlled independently of the first discharge device 15, the discharge of the intermediate phase IP via the piston valves 35 can advantageously be completely decoupled from the discharge of the solid phase SP via the inner piston slide 12. This allows the intermediate phase IP to be discharged from the centrifuge drum 1 independently of the solid phase SP.

[0073] The actuation of the inner piston slide 12 and the actuation of the controllable piston valves 35 can be controlled independently of each other by a control unit (not shown here). The control unit can also be a central centrifuge control unit, which, in addition to controlling the inner piston slide and the piston valves 35, is also intended for other control and regulation tasks of the centrifuge.

[0074] In Fig. 3 A third centrifugal separator is shown. The basic design is largely the same as the separator of the Fig. 1 and 2 . The following mainly describes deviations and / or additions to the design variant of the Fig. 1 and 2 described.

[0075] In contrast to the design variant of the centrifuge according to Fig. 1 or 2 shows the design variant of the centrifuge Fig. 3 neither an inner piston slide 12 nor an outer piston slide 22.

[0076] In the version of the centrifuge according to Fig. 3 the intermediate phase IP is controlled by at least one, preferably several piston valves 35, which are distributed around the circumference of the centrifugal drum 1 - as already described for the embodiment according to Fig. 2 described - derived from the centrifugal drum 1. The piston valves 35 here are the opening and closing means of the discontinuously operating, second discharge device 26, which serves to discharge the intermediate phase IP from the centrifugal drum 1.

[0077] Likewise, the solid phase SP is also Fig. 3 by at least one, preferably several piston valves 38, which are distributed around the circumference of the centrifugal drum 1, from the centrifugal drum 1. The piston valves 38 here are the opening and closing means of the discontinuously operating, first discharge device 15, which serves to discharge the solid phase SP from the centrifugal drum 1.

[0078] Via the nozzle-like pipes 23 and corresponding axially extending bores 24 in a wall of the drum base 3 or via bores 40 in the wall of the drum base 3 of the centrifugal drum 1, both the solid phase SP and the intermediate phase IP reach the respective piston valves 35, 38, which are mounted at different heights (relative to a bottom of the centrifugal drum 1 or the drum base 3) in the outer wall of the drum base 3 of the centrifugal drum 1. The radius R3, on which the inlet opening of the pipe 23 for discharging the intermediate phase IP is arranged, is smaller than the radius R2, on which the solid discharge openings 13 are arranged, but larger than the radius R1, on which the liquid phase LP is discharged by the paring disc 11.

[0079] The first discharge device 15 comprises an opening fluid supply 39 for fluidically actuating the respective piston valve 38, via which control fluid can be supplied to the respective piston valve 38. The control fluid can open the respective piston valve 38 when the solid phase SP is to be discharged from the centrifuge drum 1.

[0080] The second discharge device 26 also includes an opening fluid supply 36 for fluidic actuation of the respective piston valve 35, via which control fluid can be supplied to the respective piston valve 35. The control fluid can open the respective piston valve 35 when the intermediate phase IP is to be discharged from the centrifuge drum 1.

[0081] The opening time of the respective piston valves 35, 38 can be adjusted by the duration of the control fluid supplied. The piston valves 35, 38 are each arranged in the wall of the drum base 3 of the centrifugal drum 1 in such a way that they are closed by centrifugal force.

[0082] The opening fluid for the piston valves 35, 38 is metered via corresponding opening fluid valves V8, V9, which are each inserted into opening fluid supplies 17, 18.

[0083] The separate, second discharge device 26, which can be controlled independently of the first discharge device 15, enables the discharge of the intermediate phase IP by the piston valves 35 from the discharge of the solid phase SP by the piston valves 38. As a result, the intermediate phase IP can be discharged from the centrifuge drum 1 independently of the solid phase SP.

[0084] The discharge openings 13, 25 arranged at different heights in the wall of the drum base 3 for the intermediate phase IP and for the solid phase SP, respectively, are assigned annular spaces 37, 14, so that both the solid phase SP and the intermediate phase IP can be discharged separately. Each annular space 37, 14 has a nozzle 37', 14' arranged radially on the respective annular space 37, 14. The respective nozzle 37', 14' is intended for connecting a hose or line for further discharge of the respective phase.

[0085] The valves V1 to V9 of the various embodiments are preferably designed as controllable valves, in particular as electrically controllable valves, which can be connected to the control device. Bezugszeichen

[0086] 1 Centrifugal drum 2 Housing 3 Lower drum section 4 Upper drum section 5 Locking ring 6 Distributor 7 Disc pack 8 Inlet pipe 9 Liquid discharge 9 Annular space 9 Connection piece 10 Peeling disc chamber 11 Peeling disc 12 Inner piston slide 13 Solids discharge opening 14 First annular space 14 Connection piece 15 First discharge device 16 Injection chamber 17 Injection chamber 18 Opening fluid supply 19 Closing fluid supply 20 Piston valve 21 Second annular space 21 Connection piece 22 Outer piston slide 22 Support ring 23 Pipe 24 Bore 25 Discharge opening 26 Second discharge device 27 Injection line 28 Injection line 29 Opening fluid supply 30 Closing fluid supply 31Piston valve 32Overflow bore 33Third annulus 33'Connector 34Fourth annulus 34'Connector 35Piston valve 36Opening fluid supply 37Second annulus 37'Connector 38Piston valve 39Opening fluid supplies 40Bore DRotation axis SSuspension LPLiquid phase SPSolid phase IPIntermediate phase R1Radius R2Radius R3Radius V1, V5First opening fluid valve V2, V6First closing fluid valve V3Second opening fluid valve V4Second closing fluid valve V7Opening fluid valve V8Opening fluid valve V9Opening fluid valve

Claims

1. Self-draining separator for centrifugally separating a suspension S into at least a light liquid phase LP, a heavy solid phase SP, and a moderately heavy intermediate phase IP, comprising at least the following: a) a centrifuging drum (1) which is rotatable about a rotational axis D, into which the suspension S to be processed can be introduced, b) at least one liquid discharge (9) for the light liquid phase, c) at least one or more discontinuously acting solid matter discharge opening(s) (13) for the heavy solid phase SP, to which at least one first actuatable discharge device (15) is assigned, by means of which the at least one or more solid matter discharge opening(s) (13) can be opened discontinuously and closed again, and d) at least one or more discontinuously acting discharge opening(s) (25) for the intermediate phase IP, to which at least one second actuatable discharge device (26) is assigned, by means of which the at least one or more discharge opening(s) (25) for the intermediate phase IP can be opened discontinuously and closed again, wherein the second discontinuously acting discharge device (26) can be actuated independently of the first discontinuously acting discharge device (15), so that the discharge of the intermediate phase IP can take place temporally independently of the discharge of the solid phase SP, characterized in that e) nozzle-like tubes (23) are placed in or at the discharge openings (25) for the intermediate phase IP, the length of which tubes is such that they extend radially up to a radius R3 into a layer of the intermediate phase IP forming radially in the centrifuging drum (1) during rotation thereof, so that the discharge of the intermediate phase IP from the centrifuging drum (1) takes place on this radius R3.

2. Self-draining separator according to claim 1, characterized in that - the first discharge device (15) comprises at least one fluidically, in particular hydraulically, and / or electrically actuatable as well as mechanically acting opening and closing means, with which the at least one or more solid matter discharge opening(s) (13) can be opened and closed, and - the second discharge device (26) comprises at least one fluidically, in particular hydraulically, and / or electrically actuatable and mechanically acting opening and closing means, with which the at least one or more discharge opening(s) (25) for the intermediate phase IP can be opened and closed.

3. Self-draining separator according to claim 2, characterized in that the mechanically acting opening and closing means of the first discharge device (15) is a piston slide valve (12) which is arranged in or on the outside of the centrifuging drum (1) and, in particular, can be hydraulically actuated and can be moved into different positions in order to open the one or more solid matter discharge openings (13) in an open position or to close them in a closed position.

4. Self-draining separator according to one of the preceding claims, characterized in that the mechanically acting opening and closing means of the first discharge device (15) has at least one or more electrically or fluidically actuatable valves, in particular piston valves (38), which are assigned to the respective solid matter discharge opening or openings (13) in order to open them or to close them in a closed position.

5. Self-draining separator according to one of the preceding claims, characterized in that the mechanically acting opening and closing means of the second discharge device (26) is a piston slide valve (22) which is arranged on the outside of the centrifuging drum (1) and, in particular, can be hydraulically actuated and can be moved into different positions in order to open the one or more discharge openings (25) for the intermediate phase IP in an open position or to close them in a closed position.

6. Self-draining separator according to one of the preceding claims, characterized in that the mechanically acting opening and closing means of the second discharge device (26) has at least one or more electrically or fluidically actuatable valves, in particular piston valves (35), which are assigned to the respective discharge opening or openings (25) for the intermediate phase in order to open them or to close them in a closed position.

7. Self-draining separator according to one of the preceding claims 2 to 6, characterized in that the mechanically acting opening and closing means of the first discharge device is a piston slide valve (12) arranged in the centrifuging drum (1) and in particular hydraulically actuatable, and in that the mechanically acting opening and closing means of the second discharge device (26) is a further and in particular hydraulically actuatable piston slide valve (22) arranged on the outside of the centrifuging drum (1).

8. Self-draining separator according to one of the preceding claims 2 to 6, characterized in that the mechanically acting opening and closing means of the first discharge device is a piston valve (12) arranged in the centrifuging drum (1) and in particular hydraulically actuatable, and in that the mechanically acting opening and closing means of the second discharge device (26) has hydraulically or electrically actuatable piston valves (35), which are assigned to the respective discharge openings for the intermediate phase IP in order to open them or to close them in a closed position.

9. Self-draining separator according to one of the preceding claims 2 to 6, characterized in that the mechanically acting opening and closing means of the first discharge device has hydraulically or electrically actuatable piston valves (38) which are assigned to the respective solid matter discharge openings in order to open them or to close them in a closed position, and in that the mechanically acting opening and closing means of the second discharge device (26) has further hydraulically or electrically actuatable piston valves (35) which are assigned to the respective discharge openings for the intermediate phase IP in order to open them or to close them in a closed position.

10. Self-draining separator according to one of the preceding claims, characterized in that the nozzle-like tubes (23) are distributed on the circumference of a lower drum part (3).

11. Self-draining separator according to one of the preceding claims 1 to 8, characterized in that the nozzle-like tubes (23) are distributed on the circumference of the inner piston slide valve (12).

12. Self-draining separator according to one of the preceding claims, characterized in that the radius R3 is smaller than a radius R2 on which the solid matter discharge openings (13) are arranged, but larger than a radius R1 on which the liquid phase LP is discharged.

13. Self-draining separator according to one of the preceding claims, characterized in that a peeling disc (11) is assigned to the liquid discharge (9).

14. Self-draining separator according to one of the preceding claims, characterized in that the suspension S to be processed can be introduced into the centrifuging drum (1) through an inlet pipe (8) and a distributor (6).

15. Self-draining separator according to one of the preceding claims, characterized in that the discharged solid phase SP passes through the at least one solid matter discharge opening (13) into a first annular space (14), which is arranged in a hood-like housing (2) and has a nozzle (14') arranged radially on the first annular space (14) for connection of a hose or a line for further discharge of the solid phase SP.

16. Self-draining separator according to one of the preceding claims, characterized in that the discharged intermediate phase IP passes through the at least one discharge opening (25) into a further annular space (33, 37) which is arranged in the hood-like housing (2) and has a nozzle (33', 37') arranged radially on the further annular space (33, 37) for connection of a hose or a line for further discharge of the intermediate phase IP.

17. Method for operating a self-draining separator according to one of the preceding claims, characterized by following method steps: a) providing the self-draining separator in operation and a suspension S, b) introducing the suspension S into a centrifugal field of a centrifuging drum (1) of the separator through an inlet pipe (8) and a distributor (6), c) discharging at least one liquid phase LP by the liquid discharge (9), d) discontinuously discharging a solid phase SP through at least one solid matter discharge opening (13), to which a first discharge device (15) is assigned, by means of which the at least one solid matter discharge opening (13) can be opened and closed discontinuously, e) discontinuously discharging an intermediate phase IP through the at least one discharge opening (25) for the intermediate phase IP, to which the second discharge device (26) is assigned, with which the at least one discharge opening (25) for the intermediate phase IP can be opened and closed discontinuously, f) wherein the second discharge device (26) can be actuated and is actuated independently of the first discharge device (15), so that the discharge of the intermediate phase IP can be decoupled from the discharge of the solid phase SP.

18. Method according to claim 17, characterized in that the method steps b) to f) run in parallel in time.

19. Method according to claim 17 or 18, characterized in that the method steps d) and e) run periodically or aperiodically.

20. Method according to one of claims 17 to 19, characterized in that the method steps d) and e) have a different period duration.