Separator

Abstract

The invention relates to a separator, in particular a self-emptying separator, for the centrifugal separation of a free-flowing product P into at least one liquid phase (L) and at least one solid phase (S), the separator comprising a rotatable centrifugal drum (1) having a vertical axis of rotation D, the drum comprising a separation chamber (10) in which a disc stack (6) is preferably provided and comprising solid discharge openings (9), and the separator comprising an emptying mechanism having a piston valve (8), which is designed to intermittently open and close the solid emptying openings (9), wherein a control arrangement for the emptying mechanism is provided which comprises a chamber for a fluid and a valve arrangement having at least one valve (14) that is in communication with the chamber in order to operate the piston valve (8), wherein: a. as the fluid, the product P to be clarified can be fed from a distributor (5) or the separation chamber (10) of the centrifugal drum (1) via a supply channel (12) in the drum to the chamber; and b. the valve (14) is in the form of a centrifugal force valve, which closes against a spring force by centrifugal force at the operating speed of the centrifugal drum (1) and is opened by this spring force at a lower speed of the centrifugal drum (1) than the operating speed, or the valve (14) is in the form of an electromagnetically actuable valve.

Description

[0001] separator

[0002] The present invention relates to a self-emptying separator according to the preamble of claim 1.

[0003] Self-draining separators as defined in this document have, in addition to one or more outlets for one or more liquid phases, a draining mechanism 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 intermittently opens solids discharge openings in the drum wall for a certain period of time (open position) and closes them again (closed position). In the open position, a solid phase is drained from the centrifuge drum. This is not the case in the closed position.

[0004] In such emptying mechanisms with a piston valve, the sealing fluid used is injected into a closing chamber – usually located below the piston valve. The geometry of this closing chamber is selected so that the fluid pressure created by the rotation of the sealing fluid and acting on the piston valve is greater than the fluid pressure of the product to be clarified in the separation chamber above the piston valve. This pressure difference causes the piston valve to rise during operation and close the discharge openings in the drum, or close them again after solids have been discharged.

[0005] Through a suitable valve arrangement, such as one or more piston valves in fluid communication with the closing chamber, the closing fluid can be drained from the closing chamber during solids emptying, allowing the fluid below the piston valve to escape. This reduces the pressure acting on the piston valve in the closing chamber. The fluid pressure exerted by the product above the piston valve pushes the piston valve downward. This releases or opens the discharge openings in the drum.

[0006] DE 31 17 807 C1 describes a separator with such a discharge mechanism. GB 614 501 discloses a separator in which each discharge opening is equipped with a centrifugal valve. This valve closes the respective opening at operating speed and opens the respective opening at low drum speeds, allowing a cleaning fluid to flow through. The disadvantage of this design lies in the tolerance of the spring elements of the individual centrifugal valves. This makes it impossible to open all discharge openings absolutely synchronously—as would be required for solids discharge. A non-synchronous opening of the discharge openings would lead to undesirable drum imbalance during discharge.

[0007] A design is also known from DE 196 18 249 in which the drum is equipped with one or more centrifugal valves, which close the respective discharge opening at operating speed and open the respective discharge opening at a very low speed, allowing residual liquid to drain from the drum. However, the valves are not used to drain a solid phase, but rather to drain residual liquid from the drum at a very low speed. In this design, the valves distributed around the circumference are also not synchronized, making them unsuitable for discharging solids at only slightly reduced speeds.

[0008] The targeted reduction of the drum speed before emptying is known from DE 10 2017 112 553. In this case, a reduction in the drum speed serves to reduce wear on the drum and to protect the product being discharged.

[0009] State-of-the-art drainage systems have proven effective in practice, but they involve relatively high design complexity. The challenge to be addressed is to mitigate this problem.

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

[0011] According to claim 1, a separator, preferably a self-emptying separator for the centrifugal separation of a flowable product P into at least one liquid phase and at least one solid phase, is provided, wherein the separator has a rotatable centrifugal drum with a vertical axis of rotation, which has a separation chamber with a plate pack comprising solids discharge openings and an emptying mechanism with a piston slide that is designed to close and open the solids emptying openings, wherein a control arrangement for the emptying mechanism is provided, which has a chamber for a fluid and a valve arrangement with at least one valve that is connected to the chamber to actuate the piston slide, wherein the product to be clarified can be fed as the fluid from a distributor or the separation chamber of the centrifugal drum via an inlet channel of the chamber.

[0012] This advantageously eliminates the need to provide a hydraulic system to feed a separate fluid into the rotating system. This simplifies the design and operation of the separator and makes it more cost-effective.

[0013] It is advantageous and simple if the valve is designed as a centrifugal valve which closes at the operating speed of the centrifugal drum by centrifugal force against a spring force and is opened by this spring force at a lower speed of the centrifugal drum than the operating speed or if the valve is designed as an electromagnetically controllable valve.

[0014] If the valve is designed as a centrifugal valve, a valve is created and used that advantageously operates without auxiliary power and without control pulses from an external controller. However, it is also practical and simple if the valve is designed as an electromagnetically controlled valve.

[0015] Particularly preferably, it can be provided that the chamber is designed as a closing chamber and that by introducing liquid into the closing chamber the piston slide can be raised into a closed position and that it can be lowered into an open position by draining the fluid from the closing chamber.

[0016] In this way, it is advantageously no longer necessary to provide and / or store a separate closing and opening fluid and to provide a corresponding hydraulic system to feed it into the rotating system.

[0017] According to a preferred variant of the invention, the inlet channel forms a connecting channel between a distributor channel and the closing chamber. This easily establishes a connection between the distributor or the separator's downstream separation chamber and the closing chamber.

[0018] According to a further development of the invention, a collar-like deflector plate protrudes into the distribution channel. This ensures, in a simple design, that after a solids discharge process, the product flowing into the separator first fills the closing chamber, allowing the separation process to continue smoothly.

[0019] According to another particularly preferred embodiment of the invention, the deflection plate is designed to ensure that the product P is diverted from the separation chamber or the distributor into the inlet channel to the closing chamber before it flows further into the centrifuge drum after the closing chamber is filled with product P and the piston slide is thus in its closed position. This simple design measure ensures that the separation process can be continued quickly after solids have been emptied.

[0020] According to another particularly preferred embodiment of the invention, the valve is designed to allow the fluid to escape from the closing chamber to close the solids discharge openings. This provides a structurally simple and low-cost way of controlling the separator's solids discharge.

[0021] According to another particularly preferred embodiment of the invention, the flow conditions in the inlet channel into the closing chamber and / or in the outlet from the closing chamber are adjusted by nozzles or orifices. This allows the amount of solids discharged to be easily adjusted with a simple design and easy manufacturing process.

[0022] Advantageous processes can be implemented with the separator according to the invention. Thus, a method for performing solids emptying during centrifugal separation of a flowable product P into at least one solid phase and at least one liquid phase using a separator according to the invention is provided, wherein the method can comprise at least the following process steps: - Providing a self-emptying separator according to one of the claims related thereto and providing a flowable product or a flowable suspension to be processed;

[0023] - then introducing product into the centrifugal drum rotating at operating speed, whereby a part of the product from the separation chamber or the distribution channel passes via the inlet channel into the closing chamber, so that the piston slide is raised and the solids discharge openings are closed;

[0024] - then carry out the separation process until the solids collection chamber in the centrifugal drum is at least partially filled with solids;

[0025] - then reducing the speed of the centrifugal drum, which causes the valve to open, whereby the product escapes from the closing chamber under the piston valve, so that the piston valve is lowered into its open position and the solids discharge openings are released, so that the solid phase is emptied from the centrifugal drum; and

[0026] - then increasing the speed of the centrifugal drum to operating speed, which closes the valve and lifts the piston slide by the product flowing into the closing chamber, closing the solids discharge openings.

[0027] Further advantageous embodiments of the invention can be found in the remaining subclaims.

[0028] The invention is described in more detail below using an exemplary embodiment with reference to the drawing. The invention is not limited to this exemplary embodiment, but can also be implemented in other ways, either literally or in other equivalent ways. It shows:

[0029] Figure 1: a full section of a separator according to the invention;

[0030] The following description of the figures describes an embodiment of a separator. The individual features of this embodiment can also be combined with embodiments not shown and are also suitable as advantageous refinements of the subject matter described in one or more of the main and subclaims. The separator has a rotatable centrifugal drum 1, which, as shown in Fig. 1, can have a vertical axis of rotation D. The centrifugal drum 1 is rotated by a drive motor M, which here acts directly on a drive spindle S of the centrifugal drum 1. The drive spindle S is rotatably mounted in a machine frame G. It carries the centrifugal drum 1, which is placed on a free end of the drive spindle S.Alternatively, other drive systems are also feasible, for example, an indirect drive of the centrifugal drum 1, wherein a drive motor acts on the drive spindle of the centrifugal drum 1 via a belt drive. A drive system that acts directly on the drum and drives it without a spindle is also feasible.

[0031] The centrifugal drum 1 can be designed with a single cone and / or, as in this case, a double cone (bottom and / or top, and especially inside). The centrifugal drum 1 can have a drum bottom section 2 and a drum top section 3. These drum sections 2, 3 can be connected to each other in various ways, for example with a locking ring 4. The centrifugal drum 1 also has a product inlet pipe 7.

[0032] The separator is designed for continuous operation, not just batch operation.

[0033] A distributor 5 with at least one distribution channel 51 for supplying product from the product inlet pipe 5 into a separation chamber 10 is formed in the centrifugal drum 1. In the distributor 5, the product is transferred into the rotating system.

[0034] The centrifugal drum 1 further comprises a separation chamber 10, in which the actual centrifugal separation takes place. This chamber comprises a disc stack 6 of separation discs. It further comprises, radially outwardly, a solids collection chamber 13, in which the solid phase S separated from the suspension or the flowable product P collects during the separation and / or clarification process.

[0035] The centrifugal drum 1 has at least one liquid discharge for a liquid phase L. The centrifugal drum can also have more than one liquid discharge. The liquid discharge is designed here as a paring disc 16. The liquid discharge can also be implemented in another way. Fig. 1 shows, as an example, a so-called clarification separator, which is intended to clarify a product P to be processed in the centrifugal field or to separate a solid phase S and a liquid phase L from it. The separator can also be designed as a so-called separation separator, in which two liquid phases and one solid phase are separated from one another.

[0036] A discharge mechanism is used to drain the solid phase S. It has a piston valve 8 for opening and closing solid discharge openings 9. The solid discharge openings 9 can be circumferentially distributed in the area of ​​the largest diameter of the centrifugal drum 1. The piston valve is vertically movable here.

[0037] The emptying mechanism further comprises a control arrangement associated with the piston slide 8 for controlling its opening and closing movements.

[0038] The left half of the centrifuge in Fig. 1 shows the piston slide 8 in a lowered opening position, while in the right half of the centrifuge the piston slide 8 is shown in a raised closing position.

[0039] The control arrangement may include or be connected to a control unit not shown here. A higher-level control system of the centrifuge may also be used as this control unit.

[0040] The control arrangement here further comprises a closing chamber 11 for fluid.

[0041] This closing chamber 11 is designed such that the closing movement of the piston slide 8 can be initiated by introducing fluid and such that a closed position of the piston slide 8 can be maintained during rotation at an operating speed for centrifugal processing.

[0042] The fluid can be drained from the closing chamber 11 by means of a valve arrangement which can comprise one or more valves 14 which are connected to the closing chamber 11. In the separators according to the invention, the product P to be clarified serves as the fluid, which is filled into the centrifuge drum 1 via the inlet pipe 7 and can be led from the distributor 5 or the separation chamber 10 into the closing chamber 11.

[0043] To achieve this, at least one connecting channel in the form of an inlet channel 12 can be provided between a separation chamber 10 of the centrifugal drum 1 or the distributor 5 and the closing chamber 11. To raise the piston valve 8—that is, to close the solids discharge openings 9—the connecting channel 12 is used as an inlet channel for filling the closing chamber. Two or more connecting channels can also be provided, for example, distributed around the circumference.

[0044] As soon as the flowable product P to be processed centrifugally is fed into the centrifugal drum 1 rotating at operating speed upon entry into the distributor 5, it passes - according to Fig.1 - already in the distributor 5 from there through the inlet channel 12 directly into the closing chamber 11, builds up pressure in the closing chamber due to the rotation of the centrifugal drum 1, thereby lifting the piston slide 8 and closing the solids discharge openings 9 of the centrifugal drum 1. The separation process can now be continued in a known manner until the solids collection chamber 13 in the centrifugal drum 1 has been filled in part or entirely with solids S.

[0045] In order to be able to empty the solids collection chamber 13, the valve arrangement with at least one valve 14 is used.

[0046] According to an advantageous - but not mandatory - variant, the valve 14 can advantageously be designed as a centrifugal valve which closes at the operating speed of the centrifugal drum 1 by centrifugal force against a spring force and is opened at a lower speed of the centrifugal drum 1 than the operating speed by this spring force - which is then greater than the centrifugal force acting on the valve 14.

[0047] If, during operation, the speed of the centrifugal drum 1 is reduced using the control device to a value at which the valve 14 opens, the fluid used to close the solids discharge openings 9 escapes from the rotating system below the piston valve 8 through a drain channel 17 and the valve 14. As a result, the piston valve 8 lowers into its open position and releases the solids discharge openings 9, allowing the solid phase S to escape from the centrifugal drum 1.

[0048] If the speed of the centrifugal drum 1 is subsequently increased again, the valve 14 closes due to the increased centrifugal force, and the product P flows again into the closing chamber 11. This causes the piston slide 8 to rise back into its closed position and close the solids discharge openings 9.

[0049] The timing of the engine speed reduction and the engine speed reduction, as well as the timing of the subsequent engine speed increase and the engine speed increase, can be determined and initiated by the control unit mentioned above. The control unit also contains the engine control required for engine speed control.

[0050] If the product inlet 7 remains open during such a solids discharge process, product P continuously flows into the open closing chamber 11. Since the centrifugal valve is open, the closing pressure in the closing chamber cannot build up to such an extent that the piston slide is completely raised.

[0051] The fluid volume remaining in the closing chamber 11 depends on the selected cross-sections of the inlet channel 12 and the outlet channel 17 of the closing chamber 11. By appropriately determining these cross-sections and the duration of the emptying, it is possible to ensure that not the entire volume of solids is emptied from the centrifuge drum 1, but only a portion. The flow conditions in the inlet channel 12, into the closing chamber 11, and / or in the outlet channel 17 from the closing chamber 11 toward the at least one valve 14 can be adjusted and optimized using nozzles or orifices depending on the respective requirements.

[0052] As soon as the centrifugal drum 1 is accelerated again after a solids discharge process and the valve 14 closes as described, the piston slide 8 is also raised again by the product flowing into the closing chamber 11 and closes the solids discharge openings 9.

[0053] If the product inlet 7 is closed instead of kept open during a solids discharge process, product P no longer flows into the closing chamber 11, so that the chamber is completely emptied and the descending piston valve 8 completely opens the solids discharge openings 9. The solids discharge openings 9 can only be closed again when the speed of the centrifugal drum 1 is increased again and the product inlet 7 is opened, allowing fluid to enter the closing chamber 11.

[0054] To ensure that the product P flowing into the centrifugal drum 1 from the separation chamber 10 or the distributor 5 flows directly into the inlet channel 12 to the closing chamber 11, a collar-like deflector plate 15 can optionally be provided, which projects into the distributor channel 51. This deflector plate can extend in sections parallel to the main extension direction of the distributor channel 51 of the distributor, in which the inlet channel 12 begins.

[0055] The deflection plate 15 is preferably arranged and designed in such a way that it is ensured that the product P from the separation chamber 10 or the distributor 5 is immediately diverted during or after emptying into the inlet channel 12 to the closing chamber 11, before further product - when the closing chamber 11 is filled accordingly and the solids discharge openings 9 are closed by a closing movement of the piston slide 8 initiated thereby - flows further into the centrifugal drum 1.

[0056] Alternatively to the above-discussed valve 14 may also be designed in a different way, such as a valve that operates according to a different principle, such as a solenoid valve that can be opened and closed by control pulses. This control pulse could, for example, be transmitted wirelessly into the rotating system to a receiver on the solenoid valve (not shown). The electrical energy required for this can, for example, be transmitted to the rotating drum by means of a system that operates according to the inductive principle. Likewise, an energy storage device, such as a battery, can also be provided in the drum. Reference numerals

[0057] 1 Centrifugal drum 2 Drum base

[0058] 3 Drum top 4 Locking ring

[0059] 5 distributor 51 distribution channel

[0060] 6 Plate package 7 Product inlet

[0061] 8 Piston valve 9 Solids discharge opening

[0062] 10 Separation chamber 11 Closing chamber 12 Inlet channel 13 Solids collection chamber 14 Valve 15 Baffle plate 16 Paring disc

[0063] 17 Drain channel

[0064] D Rotary axis S Solid L Liquid phase P Product M Drive motor S Drive spindle G Machine frame

Claims

Claims: Separator, in particular a self-emptying separator, for centrifugal separation of a free-flowing product P into at least one liquid phase (L) and at least one solid phase (S), comprising a rotatable centrifugal drum (1) with a vertical axis of rotation D, comprising a separation chamber (10) in which preferably a disc pack (6) is provided, and comprising solid discharge openings (9) and a discharge mechanism with a piston valve (8) designed to open and close the solid discharge openings (9) discontinuously, wherein a control arrangement for the discharge mechanism is provided, comprising a chamber for a fluid and a valve arrangement with at least one valve (14) connected to the chamber to actuate the piston valve (8), characterized in that a.a. the fluid containing the product P to be clarified can be supplied to the chamber from a distributor (5) or the separation chamber (10) of the centrifugal drum (1) via an inlet channel (12) in the drum, b. wherein the valve (14) is designed as a centrifugal valve which, at the operating speed of the centrifugal drum (1), closes against a spring force by centrifugal force and, at a lower speed of the centrifugal drum (1) than the operating speed, is opened by this spring force, or wherein the valve (14) is designed as an electromagnetically controlled valve. Self-emptying separator according to claim 1, characterized in that the chamber is designed as a closing chamber (11) and that, by introducing fluid into the closing chamber (11), the piston slide (8) can be raised into a closed position and, by draining the fluid from the closing chamber (11), it can be lowered into an open position.Self-emptying separator according to claim 1 or 2, characterized in that the inlet channel (12) is designed as a connecting channel between a distribution channel (51) of the distributor (5) and the closing chamber (11).

4. Self-emptying separator according to claim 3, characterized in that a deflecting device projects into the distribution channel (51), which is preferably designed as a collar-like deflecting plate (15).

5. Self-emptying separator according to one of the preceding claims, characterized in that the valve (14) is provided to allow the fluid to escape from the closing chamber (11) to open the solid discharge openings (9).

6. Self-emptying separator according to one of the preceding claims, characterized in that the valve (14) is designed as a centrifugal valve.

7. Self-emptying separator according to one of the preceding claims, characterized in that the valve (14), which is designed as a centrifugal valve, closes against a spring force by centrifugal force at the operating speed of the centrifugal drum (1) and is opened by this spring force at a lower speed of the centrifugal drum (1) than the operating speed.

8. Self-emptying separator according to one of claims 1 to 5, characterized in that the valve (14) is designed as an electromagnetically controllable valve.

9. Self-emptying separator according to one of the preceding claims, characterized in that the flow conditions in the inlet channel (12) into the closing chamber (11) and / or in the outlet from the closing chamber (11) are adjusted by nozzles or orifices.

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