Separator and method for determining the degree of contamination within the drum of the separator

Abstract

The present invention relates to a method for determining the degree of contamination inside the drum (2) of a separator (1), comprising at least the steps of A) providing a value for the maximum internal volume of the drum (2), B) determining by measurement the currently available free drum volume of the drum (2), and C) comparing the values ​​from steps A and B to determine the degree of contamination inside the drum (2) and / or generate control commands, wherein steps A to C are performed during rotational movement of the separator. The present invention also relates to a separator (1).

Description

Technical Field

[0001] The present invention relates to a method for determining the degree of contamination or accumulation within the drum of a separator, and a separator equipped accordingly.

Background Art

[0002] During the operation of a disk centrifuge, deposits may form inside the drum. These deposits are formed both in the sludge chamber and within the disk stack. This is a normal process. The deposits may be unevenly distributed within the drum, causing vibrations that can be monitored by measurement.

[0003] However, the deposits can be very evenly distributed within the drum. In that case, the deposits cannot be easily recognized or detected from the outside. To detect the amount of deposits within the drum, the drum has to be opened, which requires a great deal of effort.

[0004] In any case, the deposits reduce the free volume within the drum, causing inefficient separation or non-purification within the separator, or creating a need to shorten the discharge interval for removing the separated solid or sludge phase. In the context of the present invention, discharge means that while the separator is operating, i.e., while the drum is rotating, the discharge valve is opened and a portion of the drum contents (partial discharge) or all of the drum contents (total discharge) are discharged. This type of separator is called a self-discharging separator.

[0005] In the case of a separator, to remove accumulations that cannot be removed even when emptied (for example, accumulations within the disk stack), the maintenance intervals have to be shortened accordingly. This manual cleaning is time-consuming and reduces the usefulness of the separator. Therefore, it must be carried out at a sufficiently early stage so that the drum is not overly contaminated. For safety reasons, the maintenance interval is selected to be short as a preventive measure, but this is not desirable for economic reasons.

[0006] It is desirable if the interior of the drum can be checked continuously or at least regularly, simply due to deposits. This can guarantee the processing engineering function of the separator, improve the reliability of operation, and enhance the usefulness.

[0007] When deposits accumulate in the drum, if the drum becomes unbalanced, it is dangerous for the operation of the centrifuge.

[0008] So far, there has been no monitoring of the free volume within the drum. Occasionally, the centrifuge can detect a completely filled solid space. Therefore, when a reduction in the free drum volume due to deposits occurs, it is still not possible to take early and appropriate measures.

[0009] International Publication No. 2018 / 177711 discloses a method for determining the volume balance VAP = VKP + VF while operating the separator, which shifts when there are lumps, obstructions, or adhesions within the disk stack. This is done by flow measurement.

[0010] However, this International Publication No. 2018 / 177711 does not disclose how the free drum volume is determined, nor does it disclose a sensor suitable for this purpose to indicate a complete filling of the drum. Therefore, the determination of the free drum volume is not done here. Since there is no criterion when the drum is completely filled and thus the measurement must be stopped, the measurement of the flow rate at the inlet is not sufficient (page 7, last paragraph), and thus the measurement must be stopped.

[0011] German Published Patent Application No. 4204805 discloses a method for determining the free drum volume. For this purpose, the drum is stopped and the contents are drained into a measuring container. Further, German Published Patent Application No. 4204805 does not disclose the application of this method to a disk separator. The disk stack is used to increase the effective cleaning area. However, the determination of the volume with the drum at rest is falsified by the disks added to the drum because liquid in the form of droplets remains on the stationary disk stack. The amount of droplets remaining in the drum affects the accuracy of the determination of the free drum volume because the droplets are erroneously regarded as deposits within the volume balance. In this case, Vdeposit = Vsolid + Vdroplets. Also, since the amount of adhering liquid strongly depends on the degree of disk contamination, there is no reproducibility.

[0012] Furthermore, the present invention generally assumes a separator, which is usually called a self-draining separator. This means that emptying is performed under a high G value. The adhering solids are deposits within the drum and are not removed, for example, by a solid discharge section such as a nozzle.

[0013] International Publication No. 2009 / 010630 discloses only the determination and metering of the supplied displacement. There is a pressure sensor at the drum outlet, but the use of a sensor for determining the drum volume is not disclosed in this context.

[0014] The detection of a contaminated drum containing at least partially contaminated disk stacks was completely or at least not accurately possible.

[0015] In the prior art, when drum vibration occurs or the turbidity value of the cleaning phase increases (in the case of a cleaning device), only measures such as additional drainage are found.

[0016] In other methods, the interval for emptying is determined and can at most be shortened but not lengthened. The free drum volume is not monitored.

[0017] European Patent No. 2170520 discloses a system for optimizing the amount of replacement liquid in a separator. This replacement liquid is used to replace the useful phase from the drum before the sludge phase becomes empty.

[0018] For this purpose, the replacement liquid must be heavier than the useful phase but lighter than the sludge phase. Also, even when the discharge amount is inaccurate, i.e., too much, it can be replaced from the drum, minimizing the loss of the useful phase product.

[0019] The amount of the replacement liquid, for example water, is adjusted based on the same pressure. Specifically, the volumetric flow rate of the introduced water is measured here by a Venturi nozzle. Thus, although the amount of water is not directly determined, the amount is calculated based on the pressure difference and the properties of water. Summary of the Invention Problems to be Solved by the Invention

[0020] Based on the above problems, an object of the present invention is to provide a method for determining the degree of contamination that can be implemented without manually disassembling the separator. Means for Solving the Problems

[0021] The present invention solves the above object by a method having the features of claim 1 and in a constructively refined method, and by a separator having the features of claim 15.

[0022] The method of the present invention for determining the amount of contamination in the drum of a centrifuge includes at least the following steps. A step of providing a value for the maximum internal volume of the drum

[0023] This value is the so-called technical internal drum volume and represents a design-related value calculated theoretically. Alternatively, the value can also be determined as a reference value by measurement and then after maintenance including manual cleaning inside the drum by subsequent filling.

[0024] Step of determining the currently available free drum volume of drum B by measurement The currently available free drum volume represents the drum volume after one or more production cycles with deposits accumulated in the drum. C Compare the values of step A and step B, determine the degree of contamination in the drum, and generate a control command.

[0025] In step C, contamination is determined by comparing the values given in step A and step B. The amount of contamination is output to the user. Alternatively, the amount of contamination can be reduced by a control command, for example, a command to stop the separator or start intensive cleaning.

[0026] At the same time, in order to implement the method according to the invention for determining the amount of contamination, it is not necessary to stop the separator, but it is shown that it is carried out during operation, that is, with the drum rotating. The rotation of the drum is not interrupted. This applies to steps A to C of the present method, but it is desirable that it also applies to all other variations of the method described later.

[0027] In particular, considering German Published Gazette No. 4204805, it is not necessary to shut down and stop the separator. Therefore, the stop time and start-up time of the separator are completely eliminated. As already explained with respect to German Published Gazette No. 4204805, by measuring with a rotating system, when measuring the liquid discharged from a stationary drum, the drawback that an indefinite amount of residual liquid remains in the stationary drum can be avoided.

[0028] For the determination of the degree of contamination, there are both a comparison with a specific numerical value and a limit value of the maximum allowable degree of contamination for which no countermeasures need to be taken yet.

[0029] By the above method, the maintenance period and the cycle of manually emptying the centrifuge can be extended.

[0030] This increases the usefulness of the separator because the drum opening and manual cleaning must only be carried out when the drum shows a significant amount of deposits. Preliminary cleaning can be omitted.

[0031] If the amount of deposits in the drum, and thus the reduced free volume, is known, for example, the volume of the sludge chamber can be calculated according to the deposits, so that the emptying interval can be adjusted dynamically.

[0032] When referring to the emptying interval here, it means opening the separator and emptying it manually, manually activating the automatic emptying function, and the automatic emptying process. Emptying can be understood as partial emptying or complete emptying.

[0033] Also, less discharge means that the solid treatment cost is reduced and the loss of the replacement phase and the optional value phase is small. Another way to reduce deposits is to adjust the emptying method. The standard is one discharge, but depending on the degree of deposits, it is also possible to carry out it two or more times with the intervention of flushing water. These measures also improve the reduction of deposits. This can also be adjusted as appropriate by generating the above control commands.

[0034] A further advantageous configuration of the method according to the invention is the subject matter of the dependent claims.

[0035] Therefore, the measurement by determining the currently available free drum volume can preferably be carried out by the following steps. I. Providing a self-discharging separator; II. A step of filling a drum and determining the volume of liquid required to fill the drum, where the volume of the liquid corresponds to the free drum volume of the currently available drum.

[0036] Unlike a manually emptied separator, a self-draining separator can still have deposits or accumulations inside the drum, which reduce the maximum internal drum volume to the current free drum volume. Preferably, the drum is filled completely up to the line of the heavy liquid phase product outlet. Therefore, not only the entire drum but also the rotatable and non-rotatable parts of the supply and discharge systems belonging to the drum are covered by the filling. This allows for a sufficient assessment of the degree of deposits and contamination.

[0037] Subsequently, the filling state of the drum can advantageously be detected by measuring with a sensor of the separator. Preferably, at least one or more pressure sensors and / or one or more limit switches, for example, a capacitive limit switch or a conductivity limit switch that detects when the filling level is reached by changing conductivity, are suitable for this purpose. Other limit switches are based on ultrasonic waves. Since the speed of sound in water is much faster than in air, a change in the medium can be detected at the position of the limit switch. Optical level switches are also conceivable.

[0038] The pressure sensor or limit switch can preferably be arranged at the outlet of the liquid phase, in particular, at the outlet of the heavier liquid phase of the separator.

[0039] Before determining the free internal drum volume, an automatic cleaning procedure, for example, CIP and / or SIP cleaning, can optionally be started without disconnecting the separator.

[0040] Also, especially when using a pressure sensor, it is advantageous if the separator has a valve that is closed during the filling of the drum at the outlet of the liquid phase and downstream of the sensor with respect to the flow, and is opened by the sensor when the filling state of the drum is detected.

[0041] The liquid introduced to fill the drum is preferably replacement water, where the first replacement water inlet of the separator for filling the drum and the product inlet of the separator open into a common inlet pipe. The supply pipe can be arranged parallel, in particular concentric, to the axis of rotation of the separator.

[0042] A control water inlet for actuating the discharge of solids from the separator can also be provided. The determination of the volume required to fill the drum is carried out by a measuring device for determining the supply quantity, in particular by a flow meter. This measuring device is preferably installed in or at the replacement water inlet.

[0043] The control signals generated in step C are preferably output by an output unit and used, for example, to initiate a warning. These are optical signals (warning lamps), display outputs or acoustic signals.

[0044] Alternatively or in addition, the control signals can act directly on the operation of the separator and can in particular cause an emergency stop or an adjustment of the operating program (such as a cleaning sequence). It is also possible to adjust the time and frequency of emptying a part of the drum.

[0045] The provision of the value of the maximum internal volume of the drum can, as already explained, be achieved by reference measurements when the state of the drum is known, in particular after it has been emptied manually and / or after maintenance.

[0046] Alternatively or further, the provision of the value of the maximum internal volume of the drum can be achieved by providing, as the value of the maximum internal volume of the drum, the value of the technical drum volume by design.

[0047] Steps 1 and 2 of the above method can be repeated several times, but for reasons of redundancy can be repeated at least twice.

[0048] Also, according to the present invention, a separator configured to implement the method according to the present invention is desirable.

[0049] This consists of a rotatable drum, a product inlet, a replacement water inlet for introducing replacement water into the drum, and preferably a control water inlet for actuating the discharge of solids from the drum.

[0050] The replacement water inlet is equipped with a valve for controlling the introduction of replacement water into the drum. The replacement water inlet has a measuring device for determining the volume of replacement water to be supplied until the drum is full.

[0051] The separator has a control and / or evaluation unit equipped to control the valve device according to the determined volume of replacement water.

[0052] In particular, the control and / or evaluation unit is equipped to evaluate the volume measurement of the measuring device from the opening of the valve to the detection of the full filling of the drum can by the sensor.

Brief Description of the Drawings

[0053] Further advantages, features and details of the present invention will become apparent from the following description, in which exemplary embodiments of the present invention are described in more detail with reference to the accompanying drawings. Those skilled in the art will also conveniently consider examining the features disclosed in combination in the drawings, the specification and the claims, and forming useful further combinations by combining them. In particular, there are various ways in which these can be modified and further formed within the scope of the present invention.

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0054] The exemplary embodiments shown in FIGS. 1 and 2 show a separator 1 with a rotatably mounted drum 2, which has a technical drum volume. The technical drum volume is a theoretical value resulting from the design-related specifications of the separator 1.

[0055] This technical drum volume is determined by the dimensions of the internal volume 12 of the drum 2 and the dimensions of the upper structure arranged within the internal volume 12, such as the dimensions of the disk stack 3, the number of disks, and the distances between them. Furthermore, the size of the technical drum volume is influenced, inter alia, by the configuration of one or more inlet regions 4, distribution regions 5, shear plates 6, shear chambers 7, shear disks 8, discharge regions 9, etc.

[0056] The above list is by no means exhaustive. Depending on the configuration, the upper structure can be omitted or replaced with other upper structures without changing the overall principle described below.

[0057] Therefore, the free volume within the drum is a theoretically calculated value where there is no contamination or other types of deposits inside the drum 2.

[0058] The separator 1 also has a product inlet 10 and a replacement water inlet 11, which open into a common inlet pipe 13, which in turn at least partially forms part of the inlet region 4 within the internal volume 12 of the drum 2.

[0059] 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 the solids discharge system. Naturally, the separator 1 is configured as a three-phase separator. However, the following principles can also be applied to two-phase separators, for example, washing separators.

[0060] The separator 1 shown in FIGS. 1 and 2 has pressure sensors 23 and 24 at the first outlet 14 and the second outlet 15 of the liquid phase, respectively. These pressure sensors 23 and 24 typically enable process monitoring during the separation of purification of the light and heavy phases, for example, water contained in oil.

[0061] However, within the scope of the present invention, it is also possible to determine a so-called control volume using the aforementioned sensors.

[0062] Furthermore, the separator 1 has a control water inlet 22, which is provided, for example, to control solid discharge or emptying of solids by means of a hydraulic actuated linear displacement of a piston slide as part of a solid discharge system. Here, the water inlet 28 of the separator 1 branches into the two aforementioned water inlets 11 and 22. However, as already mentioned, the inlets 11 and 22 can also be guided separately towards the separator. Therefore, there are no restrictions on the above configuration.

[0063] The supply of the amount of replacement water to the first replacement water inlet 11 or to the second replacement water inlet 22 is controlled by the valve device 29 in FIG. 2, in particular by two valves 17, 18. These are preferably solenoid valves. Of course, the two valves 17 and 18 can also be combined into a multi-way valve, and as a result, the valve device 29 can also consist of only one valve.

[0064] The amount and / or volume of the replacement water supplied by the replacement water inlet 11 is determined by the corresponding measuring device 19, preferably by a flow meter. This can be arranged in particular at the replacement water inlet 11. The second outlet 15 for the heavy phase preferably also has a valve 20, which is preferably a solenoid valve.

[0065] The measured values determined by the measuring device 19, as well as the measured values of the pressure sensors 23, 24, are transmitted to the control and / or evaluation unit 21, and the control and / or evaluation unit 21 controls the valves 17, 18 for control and replacement, and the valve 20 for the heavy phase.

[0066] Measure the flow rate of the replacement water, and the purpose of the accompanying valve control is to determine the control volume that defines the currently available volume in the drum.

[0067] The measured values obtained by so-called control measurements become this control volume and can be compared with the specifications of the actual free volume (e.g., calculated from the shape or determined by testing). The free drum volume (technical drum volume) varies depending on the type of machine (size of the drum, number and spacing of disks, etc.) and is stored in the machine control system. Comparison of the drum contamination levels is important.

[0068] To determine this control volume, several steps are required as shown in Figure 3. In the first step 101, the supply of the product into the drum 2 is interrupted. Next, in the second step 102, the drum is emptied completely. Emptying is done, for example, through the solid discharge opening and then closed again.

[0069] Next, in step 103, the valve 18 is opened and replacement water is supplied 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.

[0070] The completion of the filling of the drum 2 is determined in step 104 by the pressure sensor 24 provided at the outlet 15 of the heavy liquid phase. The additional valve 20 at the outlet 15 of the heavy liquid phase is closed at least immediately before reaching the maximum filling state during the filling of the replacement water into the drum. When the drum is completely filled, this pressure sensor 24 detects the presence of the heavy phase, in this case the replacement water. In a cleaning device, the pressure sensor will be arranged at the liquid phase outlet.

[0071] Consequently, the drum volume can be measured several times in order to correct measurement errors using statistical methods. One or more of the above measurements are carried out during the operation of the separator, i.e. while the drum is rotating.

[0072] Instead of pressure measurement, complete filling can also be detected by means of a plurality of other sensors. Here, conductivity measurement is suitable, which detects the change in the conductivity of the medium depending on the filling level and thus the filling state. Particularly preferably, so-called limit switches are used within the scope of the invention, which are based on different physical measurement principles. Known in this context are capacitive limit switches or also inductive limit switches, for example.

[0073] Furthermore, it is also possible to optionally use two different measurement methods, for example continuous methods, in order to compensate for measurement errors.

[0074] Furthermore, the accuracy of the measurement of the volume of replacement water can be further improved by taking into account the temperature of the replacement water. In a fifth step 105, the control volume can be compared with the technical drum volume as the theoretical maximum value.

[0075] If the deviation of the currently measured free drum volume or the determined control volume exceeds a certain limit value that can be specified in the control system, the control system can suggest the necessary countermeasures or automatically initiate the corresponding steps. Furthermore, a comparison value can be determined taking into account the theoretical technical drum volume, as a result of which the degree of contamination can be better quantified for the user.

[0076] If the determined value of the control volume or a value derived therefrom exceeds the specified limit value, the operation of the drum in the production cycle can be adjusted.

[0077] Next, in the sixth step 106, the drum 2 is emptied of the replacement water. Specifically, in FIG. 2, emptying is done through the solid matter outlet 16, but when the separator is immediately refilled with the product, it is also emptied through the bypass pipe 25 opening into the solid matter collection area 26 of the separator hood 27.

[0078] Thus, contamination is detected by measuring the difference between the technical drum volume and the control volume. The control volume or free drum volume is used synonymously in this application.

[0079] If the difference between the technical drum volume and the control volume exceeds a certain value (warning value), the controller reacts accordingly in the seventh step 107 and generates a control signal. The control signal can initiate an output, such as an alarm, or take immediate action regarding the operation of the separator. Various levels of warning values are conceivable, where messages and warnings are issued or the machine is stopped.

[0080] These are, for example, repeatedly emptying the sludge phase, reducing the supply amount, and / or stopping the centrifuge. This can prevent malfunctions of the separator, damage to the separator, and insufficient centrifugation of the product.

[0081] The reference volume is obtained by periodic or non-periodic reference measurements, which can be measured, for example, during maintenance (such as a maintenance interval of 4000 hours) or at another time point.

[0082] Also, this reference measurement is compared or offset with the control volume, from which the degree of contamination, particularly the tendency for the degree of contamination to accumulate over time, is derived. Furthermore, the determination of the free drum volume can optionally include external influences such as the temperature of the product being processed and the characteristics of the product.

[0083] After maintenance, it is assumed that, for example, the separator drum is completely cleaned. The measured value of the drum volume (reference volume) after maintenance can also be evaluated. If the difference between the technical drum volume and the reference volume exceeds a certain value, for example, it can be concluded that the cleaning is insufficient.

[0084] If this difference is negative, other defects can also be inferred. For example, the number of installed disks is less than intended. In further operation of the separator, the difference between the reference volume and the control volume can also be used to determine the degree of contamination.

[0085] Combinations (average values or the like) of two measured values (the difference obtained by subtracting the control volume from the technical drum volume, and the difference obtained by subtracting the control volume from the reference volume) are also conceivable. Therefore, it can be said that both process-related (contamination) and mechanical conclusions can be drawn from this measurement. A possible and preferred measuring device for determining the replacement quantity or volume is preferably a flow meter in the context of the present invention.

[0086] A measuring device particularly suitable for determining the replacement quantity is an impeller sensor an inclined plate flow meter (water meter) an inductive flow meter (IDM) a Coriolis flow meter (advantageous because it can be measured regardless of the air entrainment in the liquid), a vortex flow meter (the measurement principle is the Karman vortex street) or vortex measurement, and further a mass flow meter such as a calorimetric flow meter, often a flow meter using the acoustic wave transit time difference method called an ultrasonic flow meter.

[0087] In the case of a mass flow meter, for example, if the density of the measured medium is known, the volume can be calculated from the mass.

[0088] When the separator is used in a continuous product processing process, the device according to the invention can comprise a separator and a buffer tank for collecting the volume in the product being processed during the determination of the impurity level or the free drum volume.

[0089] Alternatively, it is also possible to arrange two separators of the same configuration in parallel and control them so that the contamination level can be determined one by one at a time.

[0090] A specific feature of the present invention is the determination of the free drum volume of the separator during or between productions. This eliminates the need for subsequent unnecessary intermediate cleaning, thereby improving the availability of the factory. This also reduces the operating costs.

Explanation of reference signs

[0091] List of symbols 1 Separator 2 Drum 3 Disc stack 4 Inlet area 5 Distribution area 6 Shearing plate 7 Peeling chamber 8 Peeling disc 9 Discharge area 10 Product inlet 11 First replacement water inlet 12 Internal volume height 13 Inlet pipe 14 First outlet 15 Second outlet 16 Solid matter outlet 17 Valve 18 Valve 19 Measuring device 20 Valve 21 Control and / or evaluation unit 22 Control water inlet 23 Pressure sensor 24 Pressure sensor 25 Bypass pipe 26 Solid matter collection area 27 Separator hood 28 Water inlet 29 Valve device 101 First step (interruption) 102 Second step (drainage) 103 Third step (valve - replacement water - open) 104 Fourth step (filling completion) 105 Fifth step (comparison) 106 Sixth step (drainage of replacement water) 107 Seventh step (generation of control signal)

Claims

1. A method for determining the degree of contamination inside the drum (2) of a separator (1), comprising: A. providing a value relative to the maximum internal volume of the drum (2); B. determining by measurement the currently available free drum volume of the drum (2); C. comparing the values from steps A and B to determine the degree of contamination inside the drum (2) and / or generate a control command; Steps A to C are performed during the rotational operation of the separator.

2. The determination by measurement of the currently available free drum volume is performed by: I. providing a self-draining separator (1); II. filling the drum (2) and determining the volume of liquid required to fill the drum (2); The volume of liquid corresponds to the currently available free drum volume of the drum (2). The method according to claim 1.

3. The method according to claim 2, characterized in that the filling state of the drum (2) is detected by measurement using a sensor of the separator.

4. The sensor is preferably a pressure sensor (23, 24) and / or a limit switch arranged at the outlet (14, 15) of the liquid phase of the separator (1), in particular at the outlet (15) of the heavier liquid phase. The method according to claim 3.

5. The liquid introduced to fill the drum is replacement water. The replacement water inlet (11) of the separator (1) for filling the drum (2) and the product inlet (10) of the separator (1) open into a common inlet pipe (13). The method according to any one of claims 2 to 4.

6. The determination of the volume of liquid required to fill the drum (2) is performed by a measuring device (19) for determining the supply volume, in particular by a flow meter. The method according to any one of claims 2 to 5.

7. The measuring device is arranged at the replacement water inlet (11). The method according to claim 6.

8. The generated control command is output by an output unit, preferably to initiate a warning and / or take a direct action on the operation of the separator, in particular to empty it and / or initiate an emergency stop. The method according to any one of claims 1 to 7.

9. The provision of a value relative to the maximum internal volume of the drum (2) is performed by a reference measurement when the state of the drum is known, in particular after manual emptying and / or maintenance of the separator (1). The method according to any one of claims 1 to 8.

10. The method according to any one of claims 1 to 9, wherein the value provided for the maximum internal volume of the drum (2) is performed by providing a value of the technical drum volume as the value of the maximum internal volume regarding the constitution of the drum (2).

11. The method according to any one of claims 2 to 7, characterized in that steps I and II are repeated at least twice.

12. The method according to any one of claims 1 to 11, wherein at least steps B and C, more preferably all steps, are carried out without removing the separator, in particular the drum.

13. A separator for carrying out the method according to any one of claims 1 to 12, comprising a rotatable drum (2), a product inlet (10), and a replacement water inlet (11) provided with a valve (18) for introducing controlled replacement water into the drum (2), wherein this replacement water inlet (11) is provided with a measuring device (19) for determining the supply amount of replacement water until the drum (2) is filled, and the separator is provided with a control and / or evaluation unit (21), and the control and / or evaluation unit (21) is equipped to evaluate the volume measurement of the measuring device (19) from the opening of the valve (18) to the detection of the complete filling of the drum (2) by a sensor during the rotational movement of the separator.

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