Separator

Abstract

The present invention relates to a separator, in particular a self-draining 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, the drum being provided with a disc stack (6) and comprising a separation chamber (10) with a solids discharge opening (9), the separator comprising a discharge mechanism having a piston valve (8) configured for intermittently opening and closing the solids discharge opening (9), the discharge mechanism being provided with a control device comprising a chamber for a fluid and a valve arrangement having at least one valve (14) in communication with the chamber for actuating the piston valve (8). The product P to be clarified as a fluid is fed into the chamber from a distributor (5) or a separation chamber (10) of the centrifugal drum (1) via a feed channel (12) in the drum, and the valve (14) is formed as a centrifugal valve which closes by centrifugal force against a spring force at the operating speed of the centrifugal drum (1) and opens by this spring force at a speed slower than the operating speed of the centrifugal drum (1), or the valve (14) is formed as an electromagnetically controllable valve.

Description

[Technical field]

[0001] The present invention relates to a self-draining separator according to the preamble of claim 1. [Background technology]

[0002] In addition to one or more discharges for one or more liquid phases, the self-draining separator as defined herein has a fluid-driven, in particular liquid-driven, piston valve that is alternately movable between an open position and a closed position, whereby the piston valve discontinuously opens a solids discharge opening in the drum wall for a certain time (open position) and closes said solids discharge opening again (closed position). In the open position, the solids phase is discharged from the centrifuge drum. This is not the case in the closed position.

[0003] In such discharge mechanisms with a piston valve, the closing liquid used is injected into a closing chamber, usually below the piston valve. The geometry of this closing chamber is selected in such a way that the liquid pressure caused by the rotation of the closing liquid and acting on the piston valve is greater than the liquid pressure of the product being clarified in the separation chamber above the piston valve. This pressure difference causes the piston valve to rise during operation and close the discharge opening in the drum or close the discharge opening again after the solids have been discharged.

[0004] A corresponding valve arrangement, such as one or more piston valves in fluid connection with the closing chamber, allows the closing liquid to be discharged from the closing chamber during solids discharge, so that the liquid escapes below the piston valve, reducing the pressure acting on the piston valve in the closing chamber, so that the liquid pressure exerted on the piston valve by the product on the piston valve moves the piston valve downwards, which in turn releases or opens the discharge opening in the drum.

[0005] German Patent No. 31 17 807 describes a separator with such an ejection mechanism. A separator is known from GB 614 501 in which the discharge openings are provided with centrifugal valves which close the respective openings at operating speed and open them at low drum speed to allow the flow of washing liquid. A disadvantage of this arrangement is the tolerances of the spring elements of the individual centrifugal valves. As a result, it is not possible to achieve a perfectly synchronized opening of all the discharge openings required for the discharge of solids. Unsynchronized opening of the discharge openings leads to undesirable drum imbalance during discharge.

[0006] German Patent 196 18 249 also discloses an embodiment in which the drum is equipped with one or more centrifugal valves which close the respective discharge openings at the operating speed and open the respective emptying openings at a very slow speed so that the residual liquid can be discharged from the drum. However, the valves are not used to empty the solid phase but to discharge the residual liquid from the drum at a very slow speed. Even in this configuration, the valves distributed around the periphery are not synchronized and are unsuitable for discharging the solids at a slightly reduced speed.

[0007] A targeted reduction in the drum speed before discharge is known from DE 10 2017 112 553 A1, where the reduction in the drum speed serves to reduce wear on the drum or to protect the product being discharged. Summary of the Invention [Problem to be solved by the invention]

[0008] Although prior art exhaust devices have proven themselves in practice, they are relatively complex to build. The problem to be solved is to reduce this problem. [Means for solving the problem]

[0009] The invention achieves this object by means of the subject matter of claim 1.

[0010] According to claim 1, a separator, preferably a self-draining separator, is provided for centrifuging a free-flowing product P into at least one liquid phase and at least one solid phase, comprising a rotatable centrifugal drum with a vertical axis of rotation, which comprises a separation chamber with a disc stack, which separation chamber comprises a solids discharge opening and a discharge mechanism with a piston valve designed to open and close the solids discharge opening, the discharge mechanism being provided with a control device comprising a chamber for a fluid and a valve device having at least one valve communicating with the chamber and for actuating the piston valve, the product to be clarified as a fluid being fed to the chamber via a feed channel from a distributor of the centrifugal drum or from the separation chamber.

[0011] Advantageously, this approach eliminates the need for a hydraulic system to supply a separate fluid to the rotating system, which makes the separator design and operation simpler and more cost effective.

[0012] It is advantageous and simple if the valve is designed as a centrifugal valve which closes by centrifugal force against a spring force at the operating speed of the centrifugal drum and opens by this spring force at speeds of the centrifugal drum which are lower than the operating speed, or if the valve is designed as an electromagnetically controllable valve.

[0013] Valves that function advantageously without auxiliary energy and without control pulses from an external control system can be created and used if the valve is designed as a centrifugal valve, but it is practical and simple to design the valve as an electromagnetically controllable valve.

[0014] It is particularly preferred that the chamber is configured as a closed chamber and that the piston valve can be raised to the closed position by introducing fluid into the closed chamber and lowered to the open position by discharging fluid from the closed chamber.

[0015] In this way, it is advantageously no longer necessary to provide and / or store separate closing and opening fluids and a corresponding hydraulic system for supplying it to the rotating system.

[0016] According to a preferred variant of the invention, it is provided that the supply channel forms a connecting channel between the distribution channel and the closed chamber, in this way the connection between the separation chamber of the distributor or a downstream separator and the closed chamber is realized in a simple manner.

[0017] According to a further development of the invention, it is provided that a collar-shaped baffle plate protrudes into the distribution channel, which simply ensures that the product entering the separator after the solids discharge process fills the closed chamber first, so that the separation process can be continued quickly.

[0018] According to a further particularly preferred embodiment option of the present invention, it is provided that the baffle plate is designed in such a way that after the closed chamber is filled with product P and the piston valve is in the closed position, the product P is diverted from the separation chamber or distributor into the feed channel to the closed chamber before it further flows into the centrifuge drum. This simple design measure ensures a fast continuation of the separation process after the solids have been discharged.

[0019] According to a further particularly preferred embodiment option of the present invention, a valve is provided to allow the fluid to escape from the closed chamber and close the solids discharge opening, which results in a structurally simple option for controlling the solids discharge of the separator, which can be manufactured with low manufacturing efforts.

[0020] According to a further particularly preferred embodiment option of the present invention, it is provided that the flow conditions in the feed channel into the closed chamber and / or in the outlet from the closed chamber are adjusted by means of nozzles or orifices, in this way the amount of discharged solids can be easily adjusted from the point of view of design and manufacturing technology.

[0021] An advantageous method can be carried out using the separator according to the invention. Thus, a method for carrying out a solids discharge in a centrifuge into at least one solid phase and at least one liquid phase of a freely flowing product P produced using the separator according to the invention comprises at least the following method steps: Providing a self-draining separator according to one of the related claims and providing a free-flowing product or suspension to be treated; Introducing the product into the centrifugal drum rotating at an operating speed, where a portion of the product from the separation chamber or distribution channel enters the closed chamber via the feed channel, so that the piston valve is lifted and the solid discharge opening is closed; conducting the separation process until the solids collection chamber in the centrifuge drum is at least partially filled with solids; the solid phase is discharged from the centrifuge drum by slowing down the rotation speed of the centrifuge drum and opening the valve, thereby allowing the product to escape from the closed chamber under the piston valve, lowering the piston valve to an open position and clearing the solid discharge opening; Increasing the speed of the centrifugal drum to an operating speed, which closes the valve and causes the piston valve to be lifted by the product flowing into the closed chamber, thus blocking the solids discharge opening.

[0022] Further advantageous configurations of the invention can be found in the other dependent claims. [Brief description of the drawings]

[0023] In the following, the invention will be explained in more detail by means of an exemplary embodiment and with reference to the drawings, to which the invention is not limited but which can also be realized in other ways according to the text or in other equivalent ways. [Figure 1] FIG. 2 is a full cross-sectional view showing a separator according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] In the following description of the drawings, exemplary embodiments of the separator are described, the individual features of which can also be combined with exemplary embodiments not shown, in each case as advantageous configurations of the objects set out in each or several of the main and dependent claims.

[0025] The separator has a rotatable centrifugal drum 1, which, as shown in FIG. 1, has a vertical axis of rotation D. The centrifugal drum 1 is rotated by a drive motor M, which in this case acts directly on the drive spindle S of the centrifugal drum 1. The drive spindle S is rotatably mounted on a mechanical frame G, which carries the centrifugal drum 1 arranged at the free end of the drive spindle S. Alternatively, other drive systems are also possible, for example an indirect drive of the centrifugal drum 1, whereby the drive motor acts on the drive spindle of the centrifugal drum 1 via a belt drive. Drive systems acting directly on the drum and driving the drum without a spindle are also possible.

[0026] The centrifugal drum 1 can have a single and / or double conical shape (bottom and / or top and especially the inside). It can have a lower drum part 2 and an upper drum part 3. These drum parts 2, 3 can be connected to each other in various ways, for example by means of a locking ring 4. The centrifugal drum 1 also has a product feed pipe 7.

[0027] The separator is designed for continuous operation, not just batchwise operation. The centrifugal drum 1 is formed with a distributor 5 having at least one distribution channel 51 for supplying the product from the product feed pipe 7 to the separation chamber 10. The product is transferred to a rotating system in the distributor 5.

[0028] The centrifugal drum 1 also comprises a separation chamber 10 where the actual centrifugation takes place. It is equipped with a disc stack 6 of separating discs, and radially outwards there is a solids collection chamber 13 where the solid phase S or the free-flowing product P separated from the suspension during the separation and / or clarification process is collected.

[0029] The centrifugal drum 1 has at least one liquid outlet for the liquid phase L. The centrifugal drum can also have two or more liquid outlets. The liquid outlet is configured here as a paring disc 16. The liquid outlet can also be realized in other ways.

[0030] 1 shows an example of a so-called clarification separator, which is configured to clarify a product P that is treated in a centrifugal field or to separate a solid phase S and a liquid phase L from the product P. The separator can also be configured as a so-called separation separator, in which two liquid phases and a solid phase are separated from each other.

[0031] The discharge mechanism is used to discharge the solid phase S and has a piston valve 8 which opens and closes solid discharge openings 9. The solid discharge openings 9 may be distributed around the circumference within the area of ​​the maximum diameter of the centrifugal drum 1. The piston valve is here vertically movable.

[0032] The ejection mechanism also includes a control associated with the piston valve 8 for controlling its opening and closing operation.

[0033] The left half of the centrifuge in FIG. 1 shows the piston valve 8 in a lowered, open position, and the right half of the centrifuge shows the piston valve 8 in a raised, closed position. The control device may have or be connected to a control unit, not shown here, where a higher-level control unit of the centrifuge may also be used as this control unit.

[0034] Here, the control device also comprises a closing chamber 11 for a fluid, which is designed so that the closing movement of the piston valve 8 can be initiated by the introduction of a fluid and that the closed position of the piston valve 8 can be maintained during rotation at the operating speed for the centrifugal process.

[0035] Fluid is exhausted from the closed chamber 11 by a valve arrangement which comprises one or more valves 14 connected to the closed chamber 11 .

[0036] The fluid used in the separator according to the invention is the product P to be purified, which is filled into the centrifugal drum 1 via a feed pipe 7 and can be fed into the closed chamber 11 from the distributor 5 or from the separation chamber 10 .

[0037] To achieve this, at least one connecting channel in the form of a feed channel 12 is formed between the separation chamber 10 or distributor 5 of the centrifugal drum 1 and the closing chamber 11. For lifting the piston valve 8 - i.e. for closing the solids discharge opening 9 - the connecting channel 12 is used as a feed channel for filling the closing chamber. Two or more connecting channels can also be provided, for example distributed around the circumference.

[0038] When the free-flowing product P to be processed enters the distributor 5 and is fed into the centrifugal drum 1 rotating at the operating speed, according to Fig. 1 the product passes from within the distributor 5 directly through the feed channel 12 into the closed chamber 11, and the rotation of the centrifugal drum 1 causes an increase in pressure in the closed chamber, which in turn causes the piston valve 8 to rise and close the solids discharge opening 9 of the centrifugal drum 1. The separation process can be continued in a known manner until the solids collection chamber 13 in the centrifugal drum 1 is at least partially or completely filled with solids S.

[0039] A valve arrangement having at least one valve 14 is used to empty the solids collection chamber 13 .

[0040] According to an advantageous, but not essential, variant, the valve 14 can be advantageously designed as a centrifugal valve, which closes at the operating speed of the centrifugal drum 1 by centrifugal force against a spring force and opens at speeds of the centrifugal drum 1 slower than the operating speed by a spring force - which is greater than the centrifugal force acting on the valve 14.

[0041] When the speed of the centrifuge drum 1 is now reduced during operation with the control device to a value at which the valve 14 opens, the fluid for closing the solids discharge opening 9 escapes from the rotating system below the piston valve 8 through the drain channel 17 and the valve 14. This causes the piston valve 8 to drop to its open position, freeing the solids discharge opening 9 so that the solid phase S can escape from the centrifuge drum 1.

[0042] Thereafter, the speed of the centrifugal drum 1 is increased again, which closes the valve 14 due to the increased centrifugal force and causes the product P to flow back into the closed chamber 11. This lifts the piston valve 8 back to its closed position and closes the solids discharge opening 9. The time during which the speed is decelerated and lowered, and the time during which the speed is subsequently increased, are determined and initiated by the aforementioned control unit, which also includes the motor control required for speed control.

[0043] During such a solids discharge process, if the product supply pipe 7 remains open, the product P will constantly flow into the open closed chamber 11. Because the centrifugal valve is open, the closing pressure in the closed chamber cannot increase and the piston valve will lift up fully.

[0044] The volume of fluid remaining in the closed chamber 11 depends on the selected cross sections of the supply channel 12 and the drain channel 17 of the closed chamber 11. By appropriately determining these cross sections and the duration of the discharge, it can be achieved that not the entire volume of solids is discharged from the centrifugal drum 1, but only a part of it. The flow conditions in the supply channel 12, in the closed chamber 11 and / or in the drain channel 17 from the closed chamber 11 in the direction of the at least one valve 14 can be adjusted and optimized using nozzles or orifices according to the respective requirements.

[0045] As mentioned above, as soon as the centrifugal drum 1 is accelerated again after the solids discharge process and the valve 14 closes, the product flowing into the closing chamber 11 also causes the piston valve 8 to rise again and closes the solids discharge opening 9.

[0046] If the product supply pipe 7 does not remain open during the solids discharge process but is instead closed, the product P will not flow further into the closed chamber 11, so that the closed chamber 11 becomes completely empty and the descending piston valve 8 fully opens the solids discharge opening 9. The solids discharge opening 9 can only close again when the speed of the centrifugal drum 1 increases again and the product supply pipe 7 is opened, allowing fluid to enter the closed chamber 11.

[0047] In order to ensure that the product P entering the centrifugal drum 1 flows directly from the separation chamber 10 or from the distributor 5 into the feed channel 12 and into the closed chamber 11, a collar-shaped deflector 15 can be optionally provided which protrudes into the distribution channel 51. It extends in the part parallel to the main extension direction of the distribution channel 51 of the distributor in which the feed channel 12 is located.

[0048] The deflector 15 is preferably arranged and designed in such a way that, when the closed chamber 11 is filled and the solids discharge opening 9 is closed by the closing action of the piston valve 8 which is initiated thereby, the product P from the separation chamber 10 or the distributor 5 is immediately redirected during or after discharge into the feed channel 12 to the closed chamber 11 before further product flows further into the centrifugal drum 1.

[0049] Alternatively, as mentioned above, the valve 14 can be configured in a different way, for example as a valve functioning according to a different operating principle, such as a solenoid valve that can be opened and closed by a control pulse. This control pulse is sent, for example by radio, to the rotating system and then to a receiver (not shown) on the solenoid valve. The electrical energy required for this can be transferred to the rotating drum, for example by a system that functions on the induction principle. However, an energy storage device, such as a battery, can also be provided in the drum. [Explanation of symbols]

[0050] Code list 1 Centrifugal drum 2 Lower drum section 3 Upper drum section 4 Locking Ring 5 distributor 51 Distribution Channels 6 Disc Stack 7 Product supply pipe 8 Piston Valve 9 Solids discharge opening 10 Separation room 11 Closed room 12 Supply Channels 13 Solids Collection Chamber 14 Valve 15 Baffle plate 16 Pairing Disk 17 Drainage Channel D Rotational Axis S solid L liquid phase P product M Drive motor S Drive spindle G Machine Frame

Claims

1. A separator for centrifuging a free-flowing product (P) into at least one liquid phase (L) and at least one solid phase (S), in particular a self-draining separator, comprising a rotatable centrifugal drum (1) with a vertical axis of rotation (D), the centrifugal drum (1) preferably comprising a separation chamber (10) in which a disc stack (6) is arranged, the separation chamber (10) comprising a solids discharge opening (9) and a discharge mechanism comprising a piston valve (8) adapted to open and close the solids discharge opening (9) discontinuously, the discharge mechanism being provided with a control device comprising a chamber for a fluid and a valve device having at least one valve (14) communicating with the chamber and for actuating the piston valve (8), a. The product (P) to be clarified as a fluid is fed from the distributor (5) or separation chamber (10) of the centrifugal drum (1) to the chamber through a feed channel (12) in the drum; b. A self-draining separator, wherein the valve (14) is designed as a centrifugal valve that closes by centrifugal force against a spring force at the operating speed of the centrifugal drum (1) and opens by this spring force at a speed slower than the operating speed of the centrifugal drum (1), or the valve (14) is configured as an electromagnetically controllable valve.

2. 2. A self-draining separator according to claim 1, wherein the chamber is configured as a closed chamber (11), and the piston valve (8) can be raised to a closed position by introducing a fluid into the closed chamber (11) and can be lowered to an open position by draining the fluid from the closed chamber (11).

3. 3. A self-draining separator according to claim 2, wherein the supply channel (12) is configured as a connecting channel between the distribution channel (51) of the distributor (5) and the closed chamber (11).

4. 4. A self-draining separator according to claim 3, characterized in that a deflection device projects into the distributor channel (51), the deflection device being preferably configured as a collar-shaped baffle plate (15).

5. 5. A self-draining separator according to any one of claims 2 to 4, wherein the valve (14) is arranged to allow fluid to escape from the closed chamber (11) and open the solids discharge opening (9).

6. 5. A self-draining separator according to any one of claims 1 to 4, wherein the valve (14) is configured as a centrifugal valve.

7. 7. A self-draining separator according to claim 6, wherein the valve (14) configured as a centrifugal valve closes by centrifugal force against a spring force at the operating speed of the centrifugal drum (1) and opens by this spring force at speeds lower than the operating speed of the centrifugal drum (1).

8. 5. A self-draining separator according to any one of claims 1 to 4, wherein the valve (14) is configured as an electromagnetically controllable valve.

9. 5. A self-draining separator according to any one of claims 2 to 4, wherein the flow conditions in the supply channel (12) into the closed chamber (11) and / or in the outlet from the closed chamber (11) are regulated by nozzles or orifices.

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