CN116457104A

CN116457104A - Method for determining the extent of contaminants in a rotor of a separator and separator

Info

Publication number: CN116457104A
Application number: CN202180077749.4A
Authority: CN
Inventors: F·蒂普肯珀; M·伦特鲁普; P·科隆法斯; U·里希特
Original assignee: GEA Westfalia Separator Group GmbH
Current assignee: GEA Westfalia Separator Group GmbH
Priority date: 2020-11-30
Filing date: 2021-11-24
Publication date: 2023-07-18
Also published as: KR20230109643A; JP2023550810A; EP4251328A1; DE102020131701A1; WO2022112304A1

Abstract

The invention relates to a method for determining the range of contaminants in a bowl (2) of a separator (1), comprising at least the following steps: a provides a value of the maximum internal volume of the drum (2); b determining the currently existing free drum volume of the drum (2) by means of a measurement technique; c comparing the values of step A and step B and determining the extent of contaminants in the rotor (2) and/or generating control commands, wherein the method with steps A to C is carried out during the rotational operation of the separator, and the invention relates to a separator (1).

Description

Method for determining the extent of contaminants in a rotor of a separator and separator

Technical Field

The invention relates to a method for determining the extent of contaminants or attachments in a rotor of a separator, and a correspondingly equipped separator.

Background

During operation of the disk centrifuge, deposits form in the interior space of the bowl. These deposits can be produced both in the slurry space and in the disk stack. This is a normal process. Deposits may be unevenly distributed in the drum, which results in vibrations, which can be monitored by measuring techniques.

They may be very evenly distributed in the drum. It is difficult to easily identify or detect the deposit from the outside. In order to identify the amount of sediment in the drum, the drum must be opened, which means a great outlay.

In both cases, the free volume within the bowl is reduced by the sediment, which may result in less efficient separation or clarification in the separator, or require a reduced drain interval for draining the separated solid or sludge phase. Emptying is understood in the context of the present invention as opening a discharge valve in the drum wall so that part of the drum contents (partial emptying) or all of the drum contents (complete emptying) can be discharged when the separator is in operation, i.e. when the drum is rotating. This type of separator is known as a self-draining separator.

In separators, the maintenance intervals must be correspondingly short in order to remove attachments (e.g. attachments in a disk stack) that cannot be removed by evacuation. Such manual cleaning is expensive and shortens the usability of the separator. It must therefore pass so early that it does not contaminate the drum too strongly. For safety reasons, the maintenance time intervals are selected correspondingly short, which is disadvantageous for economic reasons.

It is desirable that the interior space of the drum can be inspected for deposits continuously or at least periodically in a simple manner. The process function of the separator can thereby be ensured, the operational safety can be improved and the usability can be increased.

When this thus results in an imbalance of the bowl, the attachment of sediment in the bowl can become dangerous for the operation of the centrifuge.

There has heretofore been no monitoring of free volume within the bowl. Occasionally the centrifugal separator is able to detect a completely filled solid space. Thus, no early and desirable measures have been implemented to date in reducing the free drum volume by deposition.

WO2018/177711A1 discloses a method for operating a separator with a determined volume balance vap=vkp+vf, which separator moves if there is caking, clogging or sticking in the disc stack. This is done by flow measurement.

However, there is no disclosure in this document of how the free volume of the drum can be determined. The determination of the free volume of the drum is not carried out here, since a suitable sensor for this is also not disclosed, which sensor indicates a complete filling of the drum. The measurement of the inlet flow is inadequate (page 7, last paragraph) because there is no standard as to when the drum is completely filled and thus the measurement is ended.

DE4204805A1 discloses a method for determining the free volume of a rotor. For this purpose, the drum is stopped and the contents are discharged into the measuring vessel. The document also does not disclose the use of this method in a disc separator. Disc sets are used to increase the effective clear area. However, errors in determining the volume by the additional discs in the drum when the drum is stationary can occur because liquid in the form of droplets remains on the stationary disc pack. The volume of the droplets remaining in the drum affects the accuracy of determining the free drum volume, as the droplets are erroneously considered as deposits in the equilibrium. In this case V _{Deposit material} ＝V _{Solid body} +V _{Liquid drop} . The amount of adhering liquid is also not repeatable, which is largely dependent on the contamination level of the disc.

Furthermore, the present invention relates to a separator, commonly referred to as a self-emptier. This means that the evacuation takes place at a high G number. The attached solids are deposits in the bowl that are not directed out through a solids discharge, such as a nozzle.

WO2009/010630A1 discloses only the determination and metering of the volume of replacement water delivered. Although there is a pressure sensor in the outlet of the bowl, there is no disclosure in this regard of using a sensor to determine bowl volume.

Detection of a contaminated drum (including at least partially contaminated disc sets) has heretofore been completely impossible or at least inaccurate.

In the prior art, only measures exist, such as additional emptying when vibration of the drum occurs or when the turbidity value of the clarified phase increases (during clarification).

Other methods provide for a drain time interval that is fixedly predefined and can be shortened to a maximum but not lengthened. The free drum volume is not monitored.

EP2170520 discloses a system for optimizing the amount of displacement liquid in a separator. This displacement liquid is used to displace the value phase from the bowl prior to emptying the sludge phase.

For this purpose, the displacement liquid must be heavier than the value phase, but lighter than the sludge phase. Even when the draining is possible inaccurately, that is to say too much, the loss of product of the valuable phase can be minimized, since the valuable phase is indeed displaced from the drum.

The amount of displacement liquid (e.g., water) is adjusted based on its pressure. In detail, the volume flow of the introduced water is measured here by means of a venturi nozzle. Thus, the volume is calculated by the pressure difference and the characteristics of the water, wherein the volume of the water is not directly determined.

Disclosure of Invention

Starting from the above, the object of the present invention is to provide a method for determining the range of pollutants, which can be carried out without manually dismantling the separator.

The invention solves the above-mentioned object by a method having the features of claim 1 and by a separator having the features of claim 15 in a structurally aesthetically pleasing manner.

The method according to the invention for determining the extent of contaminants in a bowl of a centrifuge comprises at least the following steps:

a provides a value of the maximum internal volume of the bowl;

the value may be a so-called technical drum internal volume, which is a theoretical calculated structurally induced value. Alternatively, the value may also be determined as a reference value determined by measurement by a subsequent filling after maintenance comprising manually cleaning the inner space of the drum.

B determining the currently existing free drum volume of the drum by a measurement technique;

the free drum volume currently present represents the drum volume after one or more production cycles in which deposits have accumulated within the drum.

C compares the values of steps a and B and determines the extent of contaminants within the drum and/or generates control commands.

The contaminants are then determined in step C by comparing the values provided in steps a and B. The range of contaminants may then be output to the user. Alternatively, control instructions may be generated, such as stopping the separator or starting a hard clean, to reduce the range of contaminants.

This also shows that the separator does not have to be stopped in order to carry out the method according to the invention for determining the range of contaminants, but rather that this is done in continuous operation, i.e. while the drum is rotating. No interruption of the rotation of the drum is provided. This relates to steps a to C of the method, but preferably also to all other variants of the method described below. In particular in view of DE4204805A1, the separator does not have to be shut down in a stopped state. The closing time and the starting time of the separator are thus completely eliminated. As already explained in consideration of DE4204805A1, the disadvantage of any undefined amount of residual liquid remaining in the stationary drum when measuring the liquid flowing out of the drum is avoided when measuring in a rotating system.

The determination of the range of contaminants may include a specific value or a comparison with only the limit value of the range of maximum acceptable contaminants at which no measures need to be taken.

The above method allows for extending the maintenance cycle and manual drain cycle of the centrifuge.

The usability of the separator thus becomes higher, because the opening of the bowl and the manual cleaning must be performed only when the bowl has a significant amount of deposits. Preventive cleaning can be eliminated.

If the amount of sediment in the bowl and thus the reduced free volume is known, the discharge time interval can be dynamically adjusted, since the slurry space volume can be calculated from the sediment, for example.

If reference is made herein to an emptying time interval, this always refers to a manual emptying by opening the separator, a manually initiated function for automatic emptying itself or an automatically initiated step for emptying. Evacuation can also be understood as partial evacuation or complete evacuation.

Less emptying also means reduced removal costs for solids and less loss of the displaced phase and, if necessary, the valuable phase. Another possibility to reduce the deposit consists in adjusting the way of evacuation. The single evacuation is carried out according to the standard, but this can also be carried out doubly corresponding to the degree of sedimentation or doubly with flushing water connected between them. These measures likewise improve the reduction of deposits. This can also be adjusted accordingly by generating the control instructions described above.

Further advantageous embodiments of the method according to the invention are the subject matter of the dependent claims.

The determination of the currently existing free-drum volume measurement technique is therefore preferably carried out by the following steps:

I. providing a self-draining separator;

filling the bowl and determining the volume of liquid required to fill the bowl, which corresponds to the currently existing free bowl volume of the bowl.

Unlike manually emptied separators, self-emptying separators may also have deposits or attachments in the bowl interior that reduce the maximum bowl interior volume to the currently existing free bowl volume. The filling is preferably carried out as a complete filling of the drum up to the line at the product outlet of the heavy liquid phase. Thus, the entire drum and the parts of the input and output system belonging to the drum that are rotatable and non-rotatably arranged in the drum volume are detected filled (or filled). This allows a comprehensive assessment of the extent of the deposit or contaminant.

The filling state of the bowl can then advantageously be detected by means of a sensor of the separator by means of a measuring technique. For this purpose, at least one or more pressure sensors and/or one or more limit switches, for example capacitive limit switches or electrically conductive limit switches, are preferably required, which detect the fill level achieved by a change in the electrical conductivity. Other limit switches are based on ultrasound. Since the sound velocity in water is significantly higher than in air, a medium change can be detected at the position of the limit switch. Optical limit switches are also conceivable.

The pressure sensor or limit switch may preferably be arranged at the outlet of the liquid phase of the separator, in particular at the outlet of the heavy liquid phase.

An automated cleaning sequence, such as CIP and/or SIP cleaning, may also optionally be initiated without disassembly of the separator prior to determination of the free-bowl interior volume.

Furthermore, it is advantageous, in particular for the application of a pressure sensor, for the separator to have a valve at the outlet of the liquid phase and arranged downstream of the sensor in terms of flow, which valve is closed during filling of the rotor and which valve is opened when a filled state of the rotor is detected by the sensor.

The liquid introduced for filling the rotor is preferably displacement water, wherein the first displacement water inlet of the separator for filling the rotor and the product inlet of the separator open into a common inlet pipe. The inlet pipe may be arranged parallel to the rotational axis of the separator and in particular concentrically.

Furthermore, a control water inlet for manipulating the solids discharge of the separator may be provided.

The determination of the volume required for filling the drum is carried out by a measuring device for determining the intake volume and in particular by a flow measuring device.

The measuring device is preferably arranged in or on the replacement water inlet.

The control signal generated in step C is preferably used to initiate an output, e.g. a warning prompt, via the output unit. Here, an optical signal (warning light), a display output or an acoustic signal may be involved.

Alternatively or additionally, the control signal may take a direct action on the operation of the separator, in particular triggering an emergency stop or an adjustment of an operating program, for example a cleaning sequence. The duration or frequency of partial emptying of the bowl may also be adjusted.

As already explained, the value of the maximum internal volume of the drum is provided by reference measurements in case the state of the drum is known, in particular after manual emptying and/or maintenance.

Alternatively or additionally, the value for the maximum internal volume of the drum may be provided by providing the value for the drum volume of the technology as the value for the maximum internal volume of the drum caused by the structure.

Steps I and II of the above method may be repeated multiple times, however at least twice, for redundancy reasons.

Furthermore, according to the invention, a separator is provided, which is preferably designed to carry out the method according to the invention.

The separator includes a rotatable bowl, a product inlet, a displacement water inlet for introducing displacement water into the bowl, and preferably a control water inlet for manipulating solids of the bowl for emptying.

The displaced water inlet is provided with a valve for the controlled introduction of displaced water into the bowl. The displacement water inlet has a measuring device for determining the volume of displacement water delivered up to the filling drum.

The separator has a control and/or evaluation unit which is provided for controlling the valve device as a function of the determined displacement water volume.

In particular, the control and/or evaluation unit is equipped for evaluating the volume measurement of the measuring device from the opening of the valve until the complete filling of the drum is detected by the sensor.

Drawings

Additional advantages, features and details of the invention will be set forth in the description which follows, in which embodiments of the invention are described in detail with the aid of the accompanying drawings. Those skilled in the art will also suitably consider the features disclosed in combination in the drawings, the description and the claims individually and understand them as other combinations of interest. In particular, there are a number of possibilities to change and further improve these within the scope of the invention. The drawings show:

FIG. 1 shows a perspective view of a separator according to the invention;

FIG. 2 shows a cross-sectional view of a separator according to the invention for carrying out the method according to the invention; and

fig. 3 shows a schematic diagram of a process flow according to the invention.

Detailed Description

The embodiment shown in fig. 1 and 2 shows a separator 1 with a rotatably mounted rotor 2 having a technical rotor volume. The technical drum volume is a theoretical value derived from a predetermined value of the separator 1, which is determined by the design.

The technical drum volume is determined by the size of the inner volume 12 of the drum 2 and the structure arranged in the inner volume 12, such as the disk size and number of disk groups 3 and the distance from each other. In addition, the design of one or more of the entry zone 4, distribution zone 5, cutting discs 6, skimming chambers 7, skimming plates 8, discharge zone 9, etc. is also included in the size of the drum volume in technology.

The above list is by no means decisive. Depending on the design, it is therefore also possible to dispense with individual structures listed above or to replace them with other structures, without changing the general principle described below.

Thus, the free drum volume is a theoretically calculated value without any contaminants or other types of deposits within the drum 2.

The separator 1 furthermore has a product inlet 10 and a displacement water inlet 11, which open into a common inlet pipe 13, which itself at least partially forms part of the inlet region 4 in the interior 12 of the rotor 2.

Furthermore, the separator 1 has a first outlet 14 for the light liquid phase, a second outlet 15 for the heavy liquid phase and a solids outlet 16 as part of a solids evacuation system. It can be seen that the separator 1 is configured as a three-phase separator.

However, the following principles may also be applied to a two-phase separator, such as a clarifier separator.

The separator 1 shown in fig. 1 and 2 has pressure sensors 23 and 24 on the first and second outlets 14 and 15, respectively, of the liquid phase. These pressure sensors 23 and 24 typically enable process monitoring during separation of the light and heavy phases (e.g. cleaning of water in the oil).

However, within the scope of the invention, it is also possible to determine a so-called control volume by means of the above-described sensor.

The separator 1 furthermore has a control water inlet 22 which is provided for controlling the solids discharge or solids discharge, for example by hydraulically operated linear displacement of a piston slide which is part of the solids discharge system. The water inlet 28 of the separator 1 branches off here into the two aforementioned water inlets 11 and 22. As already mentioned, the inlets 11 and 22 may also be directed separately to the separator. There is therefore no limitation on the design.

The delivery of the displaced water quantity in the first displaced water inlet 11 or the second displaced water inlet 22 is controlled by a valve arrangement 29, in particular by two valves 17 and 18 in fig. 2. In this case, it may preferably be a solenoid valve. Of course, the two valves 17 and 18 can also be combined in one multi-way valve, so that the valve means 29 can also comprise only one valve.

The amount of displacement water delivered through the displacement water inlet 11 and/or the volume of displacement water delivered is determined by a corresponding measuring device 19, preferably a flow measuring device. The measuring device may in particular be arranged in the replacement water inlet 11.

The second outlet 15 for the heavy phase preferably likewise has a valve 20, preferably a solenoid valve.

The measured values determined by the measuring device 19, as well as the measured values of the pressure sensors 23 or 24, can be transmitted to a control and/or evaluation unit 21, which then controls the valves 17 and 18 for controlling and displacing water and the valve 20 for the heavy phase.

The purpose of measuring the flow of displaced water and the valve control associated therewith is to determine a control volume that defines the volume available in the drum.

The measured value results in the control volume from a so-called control measurement and can then be compared with a defined value of the actual free volume (calculated from geometry or determined experimentally, for example). The free drum volume (technically drum volume) depends on the machine type (drum size, number and spacing of disks, etc.) and is stored in the machine control. This comparison is then important for the contamination level of the drum.

As shown in fig. 3, this determination of control volume requires multiple steps. In a first step 101, the product entry into the drum 2 is interrupted.

The bowl is then completely emptied in a second step 102. The evacuation can take place, for example, via a solids discharge opening, which is then closed again.

Then, in step 103, the valve 18 is opened and the replacement water is fed into the drum 2 through the replacement water inlet 11. The volume of the introduced replacement water is measured by the measuring device 19 until the drum is completely filled.

The complete filling of the bowl 2 may be determined in step 104 by means of the pressure sensor 24 in the outlet 15 for the heavy liquid phase. The additional valve 20 in the outlet 15 for the heavy liquid phase is closed at least immediately before the highest filling state is reached when the drum is filled with replacement water. In the case of a completely filled drum, the pressure sensor 24 detects the presence of a heavy phase, in this case of replacement water. In a clarification separator, the pressure sensor is arranged in the outlet of the liquid phase.

The drum volume can be measured as many times as necessary in order to compensate for the measured errors by statistical methods. The above-mentioned measurement or one of the measurements is performed during continuous operation of the separator, i.e. while the bowl is rotating.

Instead of a pressure measurement, a complete filling can also be detected by a plurality of other sensors. A conductivity measurement is provided which can detect a change in the conductivity of the medium at the filling level and thus the filling state. Particularly preferably, a so-called limit switch can also be used within the scope of the invention, which limit switch can also be based on different physical measurement principles. Capacitive limit switches, vibration limit switches or the like are known here.

It is also possible to use two different measuring methods, for example in series, if necessary, in order to compensate for the measured errors as well.

Further, the above-described measurement accuracy of the volume of the replacement water can be further improved by taking into consideration the temperature of the replacement water.

In a fifth step 105, the control volume can be compared with the technical drum volume as theoretical maximum.

If the currently measured free volume of the drum or the deviation of the determined control volume exceeds a certain limit value (which can be predefined in the control device), the control device can suggest the necessary measures or can also automatically initiate the corresponding steps. The comparison value can also be determined taking into account the theoretical technical drum volume, whereby the degree (or extent) of contamination can be quantified better for the user.

If the determined value of the control volume or a value derived therefrom exceeds a predefined limit value, an adjustment of the operation of the drum in the production cycle can be performed.

The emptying of the bowl 2 and the replacement water then takes place in a sixth step 106. In particular, in fig. 2, through the solids outlet 16 or, when the separator is to be filled immediately with product, also through a bypass line 25 which opens into the solids collection area 26 of the separator hood 27.

Thus, contaminant detection can be achieved by determining the difference in the technical drum volume and the control volume.

Control volume or free drum volume is used synonymously in the context of this application.

If the difference exceeds a specific value (warning value), the control device may react accordingly and generate a control signal in a seventh step 107. The control signal may initiate an output such as a warning or take immediate action on the operation of the separator. Different levels of warning values are conceivable, wherein a report or warning is output or even the machine is stopped.

These may be, for example: repeatedly emptying the sludge phase, reducing the amount of intake and/or switching off the centrifuge. Thereby, failure of the separator, damage of the separator, or insufficient centrifugal separation of the product can be prevented.

The regular or irregular reference measurement yields the reference volume and may be performed, for example, at maintenance (e.g., maintenance time interval 4000 h) or at other times.

The reference measurement can also be compared or calculated with the control volume, from which the contamination level can be deduced, and in particular the time profile for establishing the contamination level. Furthermore, external influences, such as the temperature of the individual products to be processed or the product properties, can be combined if necessary in determining the free drum volume.

For example, after maintenance, it may be assumed that the bowl of the separator has been completely cleaned. The measurement of the drum volume (reference volume) after maintenance can likewise be evaluated.

If the difference between the technical drum volume and the reference volume exceeds a certain value, insufficient cleaning can be inferred, for example.

If the difference is negative, other faults can be inferred therefrom. For example, the number of discs loaded is less than preset. In further operation of the separator, the difference between the reference volume and the control volume may also be used to determine the range of contaminants.

A combination (average or similar) of the two measurements (technically drum volume minus control volume and reference volume minus control volume) is also contemplated.

It can therefore be said that the measurement allows technical (pollution) and mechanical conclusions.

Possible and preferred measuring means for determining the amount or volume of displaced water are preferably flow measuring means within the scope of the invention.

Suitable measuring devices, in particular for determining the volume of displaced water, are

Impeller sensor

Sloping cam plate flowmeter (Water meter)

-inductive flowmeter (IDM)

Mass flow meters, such as coriolis flow meters (which are advantageous because they measure air inclusions in liquids quite independently), vortex flow meters (the measurement principle is cage vortex street), or vortex measurements, as well as thermal flow meters;

flow meters according to the sonic propagation time difference method, commonly referred to as ultrasonic flow meters.

For mass flowmeters, for example, the volume can be calculated back from the mass of the measured medium at a known density.

If the separator is used during continuous processing of the product, the device according to the invention may comprise a separator and a buffer tank which acquires the volume of the product to be processed during the determination of the degree of contamination or the free volume of the drum.

Alternatively, two separators of identical construction can also be operated side by side in parallel, which are controlled in such a way that only the determination of the extent of the contaminants is always carried out in each case.

The invention is to emphasize the determination of the free drum volume of a separator, in particular between or during production. This increases the usability of the device, since unnecessary intermediate cleaning is not necessary afterwards. This also reduces the costs for operation.

Reference numerals

1. Separator

2. Rotary drum

3. Disk set

4. Entering the area

5. Distribution area

6. Cutting disc

7. Skimming chamber

8. Skimming plate

9. Lead-out area

10. Product inlet

11. First replacement water inlet

12. Internal volume

13. Access tube

14. A first outlet

15. A second outlet

16. Solid outlet

17. Valve

18. Valve

19. Measuring device

20. Valve

21. Control and/or evaluation unit

22. Controlling water inlet

23. Sensor for detecting a position of a body

24. Sensor for detecting a position of a body

25. Bypass pipe

26. Solid collection area

27. Separator cover

28. Water inlet

29. Valve device

101. First step (interrupt)

102. Second step (evacuation)

103. Third step (valve opening-water replacement)

104. Fourth step (complete evacuation)

105. Fifth step (comparison)

106. Sixth step (draining the displaced water)

107. Seventh step (generating control signal)

Claims

1. Method for determining the extent of contaminants in a bowl (2) of a separator (1), characterized in that the method comprises at least the steps of:

a provides a value of the maximum internal volume of the drum (2);

b determining the currently existing free drum volume of the drum (2) by means of a measurement technique;

c comparing the values of step A and step B and determining the extent of contamination within the drum (2) and/or generating control commands,

wherein the method with steps a to C is carried out during the rotational operation of the separator.

2. The method according to claim 1, characterized in that the determination of the measurement technology of the currently existing free drum volume is performed by the following steps:

I. providing a self-emptying separator (1);

filling the drum (2) and determining the volume of liquid required for filling the drum (2), which corresponds to the currently existing free drum volume of the drum (2).

3. Method according to claim 2, characterized in that the filling state of the bowl (2) is detected by means of a sensor of the separator by means of a measuring technique.

4. Method according to any of the preceding claims, characterized in that the sensor is a pressure sensor (23, 24) and/or a limit switch, which is preferably arranged at the outlet of the liquid phase (14, 15) of the separator (1), in particular at the outlet (15) of the heavy liquid phase.

5. Method according to any of the preceding claims, characterized in that the liquid introduced for filling the drum is displacement water, wherein the displacement water inlet (11) of the separator (1) for filling the drum (2) and the product inlet (10) of the separator (1) lead into one common inlet pipe (13).

6. Method according to any of the preceding claims, characterized in that the determination of the volume required for filling the drum (2) is performed by a measuring device (19) for determining the intake volume, in particular by a flow measuring device.

7. Method according to any of the preceding claims, characterized in that the measuring device is arranged in or on the displacement water inlet (11).

8. Method according to any of the preceding claims, characterized in that the generated control signal initiates an output, preferably a warning, on an output unit and/or takes a direct action on the operation of the separator, in particular starts emptying and/or emergency stops.

9. Method according to any of the preceding claims, characterized in that the value of the maximum internal volume of the bowl (2) is provided by reference to a measurement in case of a known state of the bowl, in particular after manual emptying and/or maintenance of the separator (1).

10. A method according to any of the preceding claims, characterized in that the value for the maximum internal volume of the drum (2) is provided by providing the value for the drum volume of the technology as the value for the maximum internal volume of the drum (2) caused by the structure.

11. The method according to any of the preceding claims, wherein steps I and II are repeated at least twice.

12. Method according to any of the preceding claims, characterized in that at least the steps B and C, preferably the whole method, are carried out without dismantling the separator, in particular the bowl.

13. Separator, in particular for carrying out the method according to one of the preceding claims, comprising a rotatable drum (2), a product inlet (10) and a displacement water inlet (11) for the controlled introduction of displacement water into the drum (2) by means of a valve (18), wherein the displacement water inlet (11) has a measuring device (19) for determining the volume of displacement water fed up to the drum (2), wherein the separator has a sensor for detecting a complete filling of the drum (2), characterized in that the separator (1) has a control and/or evaluation unit (21) which is equipped for evaluating a volume measurement of the measuring device (19) from the opening of the valve (18) until the complete filling of the drum (2) is detected by the sensor during a rotational operation of the separator.