DE102020131701A1 - Method for determining the extent of contamination within a drum of a separator and a separator - Google Patents

Abstract

A method for determining the extent of soiling within a drum (2) of a separator (1) with at least the following steps: A provision of a value for a maximum internal volume of the drum (2); B metrological determination of the currently available free drum volume of the drum (2);C comparing the values from steps A and B and determining the extent of contamination within the drum (2) and/or generating a control command; and a separator (1).

Description

The present invention relates to a method for determining the extent of contamination or adhesions within a drum of a separator, and a separator equipped accordingly.

When operating a disk centrifuge, deposits can form inside the drum. These deposits can occur both in the sludge chamber and in the plate pack. This is normal operation. The deposits can be unevenly distributed in the drum, which leads to vibrations that can be monitored by measurement.

However, they can also be distributed very evenly in the drum. The difficulty then is that the deposits cannot be easily recognized or detected from the outside. In order to see the amount of deposits in the drum, it has to be opened, which means a lot of work.

In both cases, the deposits reduce the free volume in the bowl, which can lead to the separation or clarification in the separator being less efficient, or to the need to shorten the emptying intervals to eject the separated solids or sludge phase. In connection with this invention, emptying is understood to mean the opening of outlet valves in the drum wall, so that parts of the drum contents (partial emptying) or the entire drum contents (complete emptying) can be ejected during operation of the separator, i.e. while the drum is rotating. Separators of this type are referred to as self-draining separators.

In the case of separators, the maintenance interval must be correspondingly short in order to remove buildup that cannot be removed by emptying (e.g. buildup in the plate stack). This manual cleaning is time-consuming and shortens the availability of the separator. It must therefore happen early enough so that the drum is not too heavily soiled. For safety reasons, the maintenance interval is chosen to be correspondingly short as a precaution, but this is unfavorable for economic reasons.

It is desirable if the interior of the drum can be easily checked for deposits continuously or at least regularly. This ensures the process engineering function of the separator, improves operational safety and increases availability.

Accumulations of deposits in the bowl can be dangerous for the operation of the centrifuge if the bowl is unbalanced as a result.

So far there is no monitoring of the free volume in the drum. Occasionally, centrifuges are able to detect a completely filled solids compartment. Thus, up to now, no early and needs-based measures can be taken to reduce the free drum volume due to deposits.

Up to now, it has not been possible to detect a dirty drum, including an at least partially dirty disk pack.

In the state of the art there are only measures such as additional emptying when vibrations of the drum occur or when the turbidity value of the clear phase (in the clarifier) increases.

Other methods provide for emptying intervals that are fixed and can be shortened at most, but not lengthened. The free drum volume is not monitored.

the EP2170520 discloses a system for optimizing the amount of displacement liquid in a separator. With this displacement liquid, the valuable phase is to be displaced from the drum before the sludge phase is emptied.

To do this, the displacement liquid must be heavier than the value phase, but lighter than the sludge phase. Even with a possibly imprecise - i.e. too large - emptying, a product loss of the value phase can be minimized, since this was pushed out of the drum.

The amount of displacement liquid, e.g., water, is adjusted based on its pressure. In detail, the volume flow of the water fed in is measured using a Venturi nozzle. The volume is calculated using pressure differences and the properties of the water, with the volume of the water not being determined directly.

Proceeding from the aforementioned problem, it is the object of the present invention to provide a method for determining the extent of contamination, which can be carried out without manual dismantling of the separator.

The present invention solves the aforementioned problem by a method having the features of claim 1 and in a structurally elegant manner by a separator having the features of claim 15.

1. A Bereitstellung eines Wertes für ein maximales Innenvolumen der Trommel; Dieser Wert kann das sogenannte technische Trommelinnenvolumen sein, welches einen theoretisch-berechneten konstruktiv-bedingten Wert darstellt. Alternativ kann der Wert auch nach einer Wartung einschließlich einer manuellen Reinigung des Trommelinnenraumes durch eine anschließende Befüllung als ein durch Messung festgestellter Referenzwert ermittelt werden.
2. B messtechnische Ermittlung des aktuell-vorhandenen freien Trommelvolumens der Trommel; Das aktuell-vorhandene freie Trommelvolumen stellt das Trommelvolumen nach einem oder mehreren Produktionszyklen dar, in welchen sich Ablagerungen innerhalb der Trommel angesammelt haben.
3. C Vergleich der Werte aus Schritt A und B und Ermittlung des Umfangs an Verschmutzungen innerhalb der Trommel und/oder Generierung eines Steuerbefehls.

A method according to the invention for determining the extent of contamination within a drum of a centrifugal separator comprises at least the following steps:

1. A providing a value for a maximum internal volume of the drum; This value can be the so-called technical inner drum volume, which represents a theoretically calculated value due to the design. Alternatively, the value can also be determined after maintenance, including manual cleaning of the interior of the drum, by subsequent filling as a reference value determined by measurement.
2. B metrological determination of the currently available free drum volume of the drum; The currently available free drum volume represents the drum volume after one or more production cycles in which deposits have accumulated inside the drum.
3. C Compare the values from steps A and B and determine the extent of contamination within the drum and/or generate a control command.

In step C, the soiling is then determined by comparing the values provided in steps A and B. The extent of the contamination can then be output to the user. Alternatively, a control command, e.g. stopping the separator or initiating intensive cleaning, can be generated to reduce the extent of contamination.

Determining the extent of the contamination can include both a specific value and only a comparison with a limit value for a maximum acceptable degree of contamination at which no measures need to be taken.

The aforesaid method allows an increase in the maintenance periods and the cycles of manual emptying of a centrifugal separator.

This increases the availability of the separator, since the drum only has to be opened and cleaned manually when the drum has a significant amount of deposits. A precautionary cleaning can be omitted.

If the amount of deposits in the drum and thus the reduced free volume is known, the emptying intervals can be adjusted dynamically, since e.g. the sludge chamber volume can be calculated according to the deposits.

If the emptying interval is mentioned here, manual emptying by opening the separator, a manually started function for automatic emptying or an automatically started emptying step is always meant. The emptying can also be understood as partial emptying or total emptying.

Fewer dumps also means reduced disposal costs for the solid and less loss of the displacement phase and, where appropriate, the value phase. Another way to reduce the deposits is to adjust the type of emptying. A single emptying is carried out as standard, but this can also be carried out twice or twice with rinsing water switched in between, depending on the degree of deposits. These measures also improve the reduction of deposits. This can also be adjusted accordingly by generating the aforementioned control command.

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

1. I. Bereitstellen eines selbst entleerenden Separators;
2. II. Befüllung der Trommel und Bestimmung des zur Befüllung der Trommel notwendigen Volumens einer Flüssigkeit, welches dem aktuell-vorhandenen freien Trommelvolumen der Trommel entspricht.

The metrological determination of the currently available free drum volume can preferably be carried out by the following steps:

1. I. Providing a self-emptying separator;
2. II. Filling of the drum and determination of the volume of liquid required to fill the drum, which corresponds to the currently available free drum volume of the drum.

Unlike a separator that has to be emptied manually, a self-emptying separator can still have deposits or adhesions in the drum interior, which reduces the maximum drum internal volume to a currently available free drum volume. The filling preferably takes place as a complete filling of the bowl up to a line at the product outlet for the heavy liquid phase. Thus, the complete drum as well as the parts belonging to the drum are rotatable and non-rotatably arranged in the drum volume of the supply and discharge system from the filling. This enables a comprehensive assessment of the extent of deposits or contamination.

The status of the filling of the drum can then advantageously be measured using a sensor of the separator. At least one or more pressure sensors and/or one or more limit switches, e.g. capacitive limit switches or conductivity limit switches, which detect when a filling level is reached by changing the conductivity, are preferably suitable for this purpose. Other limit switches are based on ultrasound. Since the speed of sound in water is significantly higher than in air, a change in medium can be detected at the position of the limit switch. Optical limit switches are also conceivable.

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

Before determining the free inner drum volume, an optional automatic cleaning sequence, e.g. CIP and/or SIP cleaning, can be initiated without dismantling the separator.

It is also advantageous, especially when using a pressure sensor, if the separator has a valve at the outlet of the liquid phase and downstream of the sensor in terms of flow, which is or is closed during the filling of the drum and which, when a filled state of the drum is detected drum is opened by the sensor.

The liquid introduced to fill the drum is preferably displacement water, with a first displacement water feed of the separator for filling the drum and a product feed of the separator opening into a common feed pipe. The feed pipe can be arranged parallel and in particular concentrically to the axis of rotation of the separator.

A control water inlet for actuating a solids emptying of the separator can also be provided.

The volume required for filling the drum is determined by a measuring device for determining an inflow volume and in particular by a flow meter.

This measuring device is preferably arranged in or on the displacement water inlet.

The control signal generated in step C is preferably used to initiate an output, e.g. of a warning, by an output unit. This can be a light signal (alarm lamp), a display output or an acoustic signal.

Alternatively or additionally, the control signal can take an immediate action on the operation of the separator, in particular triggering an emergency stop or an adjustment of the operating program, e.g. the cleaning sequence. It is also possible to adjust the duration or frequency of partial emptying of the drum.

As already explained, a value for a maximum internal volume of the drum can be provided by a reference measurement when the condition of the drum is known, in particular after manual emptying and/or maintenance.

Alternatively or additionally, a value for a maximum internal volume of the drum can be provided by providing a value for a technical drum volume as a value for the design-related maximum internal volume of the drum.

For reasons of redundancy, steps I and II of the aforementioned method can be repeated several times, but at least twice.

Also according to the invention is a separator which is preferably designed to carry out the method according to the invention.

This comprises a rotatable drum, a product feed, and a displacement water feed for introducing displacement water into the drum and preferably a control water feed for actuating a solids emptying of the drum.

The displacement water inlet is provided with a valve for the controlled introduction of displacement water into the drum. The displacement water supply has a measuring device for determining the supplied volume of displacement water until the drum is filled.

The separator has a control and/or evaluation unit which is equipped to control the valve arrangement as a function of the determined volume of water displaced.

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 until the sensor detects that the drum is completely full.

Further advantages, features and details of the invention result from the following description, in which an exemplary embodiment of the invention is explained in more detail with reference to the accompanying drawings. The person skilled in the art will expediently also consider the features disclosed in combination in the drawing, the description and the claims individually and combine them into further meaningful combinations. In particular, there are a variety of ways to do this

• 1 eine perspektivische Darstellung eines erfindungsgemäßen Separators;
• 2 eine Schnittansicht des erfindungsgemäßen Separators zur Ausführung des erfindungsgemäßen Verfahrens; und
• 3 eine schematische Darstellung des erfindungsgemäßen Verfahrensablaufs.

to modify and develop within the scope of the present invention. Show it:

• 1 a perspective view of a separator according to the invention;
• 2 a sectional view of the separator according to the invention for carrying out the method according to the invention; and
• 3 a schematic representation of the process flow according to the invention.

That in the 1 and 2 illustrated embodiment shows a separator 1 with a rotatably mounted drum 2, which has a technical drum volume. The technical bowl volume is a theoretical value, which results from the design-related specifications of the separator 1.

This technical drum volume is derived from the dimension of the inner volume 12 of the drum 2, as well as structures arranged in the inner volume 12, such as the dimension and the number of plates in a plate pack 3 and their distance from one another. Furthermore, the design of one or more inlet areas 4, distribution areas 5, separating plates 6, peeling chambers 7, peeling discs 8, discharge areas 9 and the like also influence the size of the technical drum volume.

The above list is by no means exhaustive. Thus, depending on the type of design, individual structures previously listed can also be omitted or replaced by other structures without the overall principle described below changing.

The free drum volume is thus a theoretically calculated value, without any dirt inside the drum 2 or any other type of deposits.

The separator 1 also has a product inlet 10 and a displacement water inlet 11 which open into a common inlet pipe 13 which in turn at least partially forms part of an inlet area 4 in the inner volume 12 of the drum 2 .

Furthermore, the separator 1 has a first outlet 14 for a light liquid phase, a second outlet 15 for a heavy liquid phase and a solids outlet 16 as part of a solids discharge system. The separator 1 is designed as a three-phase separator.

However, the following principle can also be applied to a two-phase separator, e.g. a clarification separator.

the inside 1 and 2 The separator 1 shown has a pressure sensor 23 and 24 at the first and at the second outlet 14 and 15 of the liquid phases. These pressure sensors 23 and 24 typically enable process monitoring during the separation of a light phase and a heavy phase, such as the cleaning of water in oil.

Within the scope of the present invention, however, it is also possible to determine a so-called control volume by means of the aforementioned sensors.

In addition, the separator 1 also has a control water inlet 22, which is provided for controlling the solids discharge or the solids emptying, e.g. by hydraulically-actuated linear displacement of a piston valve as part of a solids emptying system. A water inlet 28 of the separator 1 branches into the two aforementioned water inlets 11 and 22. As already mentioned, the inlets 11 and 22 can also be routed separately to the separator. There is therefore no restriction to the configuration mentioned.

The supply of the amount of displacement water in the first displacement water inlet 11 or in the second displacement water inlet 22 is controlled by a valve arrangement 29, in 2 concretely controlled by two valves 17 and 18. This can preferably be a matter of solenoid valves. Of course, the two valves 17 and 18 can also be combined in a multi-way valve, so that the valve arrangement 29 can also include just one valve.

The quantity and/or volume of displacement water supplied through the displacement water inlet 11 is determined by a corresponding measuring device 19, preferably by a flow meter. This can be arranged in particular in the displacement water inlet 11 .

The second outlet 15 for the heavy phase preferably also 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 the control and displacement water and the control of the valve 20 for the difficult phase.

The aim of measuring the flow rate of displacement water and the associated valve control is to determine a control volume, which defines the volume currently available in the drum.

A measured value from a so-called control measurement results in this control volume and can then be compared with a specification that is the real free volume (e.g. calculated from the geometry or determined in tests). The free drum volume (technical drum volume) depends on the machine type (size of the drum, number and spacing of the plates, etc.) and is stored in the machine control. The comparison is then significant for the degree of soiling of the drum.

The determination of this control volume requires several steps, as in 3 shown. In a first step 101, a product feed into the drum 2 is interrupted.

Then, in a second step 102, the drum is completely emptied. Emptying can take place, for example, through the solids discharge openings, which are then closed again.

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

The complete filling of the drum 2 can be determined in step 104 by the pressure sensor 24 in the outlet 15 of the heavy liquid phase. The additional valve 20 in said outlet 15 of the heavy liquid phase is closed when the drum is filled with displacement water, at least immediately before the highest filling level is reached. When the drum is completely filled, this pressure sensor 24 detects the presence of the heavy phase, in this case the displacement water. In the case of a clarification separator, the pressure sensor would be arranged in the outflow of the liquid phase.

If necessary, the drum volume can be measured several times in order to compensate for the errors in the measurement using statistical methods.

As an alternative to measuring the pressure, a large number of other sensors can also be used to detect a complete filling. A conductivity measurement is useful here, which can detect a change in the conductivity of the medium at a filling level and thus a filling status. So-called limit switches, which can also be based on different physical measuring principles, can also be used particularly preferably within the scope of the present invention. Known here are capacitive limit switches or also vibronic limit switches or the like.

It is also possible, if necessary, to use two different measurement methods, e.g. in series, in order to also compensate for the errors in the measurements.

Furthermore, the accuracy of the above measurements of the displacement water volume can be further improved by taking into account the temperature of the displacement water.

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

If the deviation of the currently measured free volume of the drum or the determined control volume exceeds a certain limit value that can be specified in the controller, the controller can either suggest necessary measures or automatically initiate appropriate steps. A comparison value can also be determined taking into account the theoretical technical drum volume, so that the degree of soiling can be better quantified for the user.

If the determined value of the control volume or a value derived from it exceeds a predetermined limit value, adjustments to the operation of the drum in the production cycle can be made.

Then, in a sixth step 106, the drum 2 is emptied of the displacement water. Specifically, the emptying takes place in 2 via the solids outlet 16 or if the separator is to be immediately filled with product again also via a diversion pipe 25 which opens out in the solids collection area 26 of a separator hood 27 .

Soiling can thus be detected by determining the difference between the technical drum volume and the control volume. Control volume or free drum volume are used synonymously in the context of the present application.

If this difference exceeds a specific value (warning value), the controller can react accordingly in a seventh step 107 and generate a control signal. The control signal can initiate an output, e.g., a warning, or take immediate action on the operation of the separator. Different levels of warning values are conceivable, at which messages or warnings are issued or even the machine is stopped.

These can be, for example: repeated emptying of the sludge phase, reduction of the feed volume and/or shutting down the centrifuge. This can prevent malfunctions of the separator, damage to the separator or insufficient centrifugal separation of the product.

Regular or irregular reference measurements result in a reference volume and can be carried out, for example, during maintenance (e.g. maintenance interval 4000 h) or at another point in time.

This reference measurement can also be compared or offset against the control volume, from which a degree of contamination and in particular a tendency towards the build-up of a degree of contamination over time can be derived. Furthermore, external influences such as temperature or product properties of the products to be processed can also be included when determining the free drum volume.

After maintenance, for example, it can be assumed that the separator drum has been completely cleaned. A measurement of the drum volume after maintenance (reference volume) can also be evaluated.

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

If this difference becomes negative, conclusions can be drawn about other errors. For example, a smaller number of built-in plates than planned. 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.

Combinations (mean value or similar) of the two measurements (technical drum volume minus control volume and reference volume minus control volume) are also conceivable.

It can therefore be said that the measurement allows both process engineering (contamination) and mechanical conclusions to be drawn.

Within the scope of the present invention, possible and preferred measuring devices for determining the quantity or the volume of the displacement water are preferably flow measuring devices.

• - Flügelradsensoren
• - Taumelscheiben-Durchflussmesser (Wasseruhr)
• - Induktive Durchflussmesser (IDM)
• - Massedurchflussmesser, wie Coriolis-Durchflussmesser (vorteilhaft, da diese von Lufteinschlüssen in der Flüssigkeit recht unabhängig messen), Wirbelstrom-Durchflussmesser (Messprinzip Kärmänsche Wirbelstraße) oder Vortex-Messung, sowie Kalorische-Durchflussmesser;
• - Durchflussmesser nach dem Schalllaufzeit-Differenzverfahren, oftmals als Ultraschall-Durchflussmesser bezeichnet

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

• - Vane sensors
• - Swashplate flow meter (water meter)
• - Inductive Flow Meters (IDM)
• - Mass flowmeters, such as Coriolis flowmeters (advantageous, since these measure quite independently of air inclusions in the liquid), eddy current flowmeters (measuring principle Karman vortex street) or vortex measurement, as well as caloric flowmeters;
• - Flow meters based on the sound transit time difference method, often referred to as ultrasonic flow meters

In the case of mass flow meters, for example, the volume can be calculated from the mass if the density of the measuring medium is known.

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

Alternatively, two identical separators can also be operated in parallel, which are controlled in such a way that only one determination of the degree of contamination is carried out in each case.

Of particular note in the present invention is the determination of the free drum volume of a separator between or during production. This increases the availability of the system, as there is no need for intermediate cleaning, which is unnecessary afterwards. This also reduces the cost of operation.

As an alternative to the embodiment described above, within the scope of the present invention, a volume measurement can be carried out using a separate vessel, the contents of which are then introduced into the separator until the drum is completely filled.

Either the vessel is filled with a defined volume or it is mechanically designed in such a way that exactly the required volume fits in when the drum is clean. Any residue in the vessel indicates that there are deposits in the drum that reduce the free volume.

Alternatively, the container has significantly more content than the separator bowl and the amount of residual liquid in the container is determined. This can be done as desired by allowing the tank to drain using a volume measurement (e.g. flow meter). Alternatively, the container can also stand on a weighing device (weighing cells) and its weight can be measured before and after emptying. Taking the temperature into account, the weight of the displacement water can be converted into a volume.

It is also conceivable to mount the separator on a permanently installed weighing device and to weigh it in the empty and full state. Taking the temperature into account, the weight of the displacement water can be converted into a volume.

Reference List

1

separator

2

drum

3

plate pack

4

inlet area

5

distribution area

6

cutting disc

7

peeling chamber

8th

paring disc

9

derivation area

10

product feed

11

first displacement water inlet

12

internal volume

13

inlet pipe

14

First drain

15

Second process

16

solids outlet

17

Valve

18

Valve

19

gauge

20

Valve

21

Control and/or evaluation unit

22

control water inlet

23

pressure sensor

24

pressure sensor

25

diversion pipe

26

solids collection area

27

separator hood

28

water inlet

29

valve assembly

101

first step (interruption)

102

second step (emptying)

103

third step (valve - displacement water - open)

104

fourth step (complete filling)

105

fifth step (comparison)

106

sixth step (emptying the displacement water)

107

seventh step (generation of a control signal)

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• EP 2170520 [0012]

Claims (15)

A method for determining the extent of contamination within a drum (2) of a separator (1) , characterized by the following steps: A providing a value for a maximum internal volume of the drum (2); B metrological determination of the currently available free drum volume of the drum (2); C Comparison of the values from steps A and B and determination of the extent of contamination within the drum (2) and/or generation of a control command. procedure after claim 1 , characterized in that the metrological determination of the currently available free drum volume takes place in the following steps: I. Providing a self-emptied separator (1); II. Filling of the drum (2) and determination of the volume of a liquid required to fill the drum (2), which corresponds to the currently available free drum volume of the drum (2). procedure after claim 2 , characterized in that the state of the filling of the drum (2) is measured using a sensor of the separator. Method according to one of the preceding claims, characterized in that the sensor is a pressure sensor (23, 24) and/or a limit switch, which is preferably located at the outlet of a liquid phase (14, 15), in particular at the outlet (15) of the heavier liquid phase, the Separator (1) is arranged. Method according to one of the preceding claims, characterized in that the liquid introduced to fill the drum is displacement water, with a displacement water inlet (11) of the separator (1) for filling the drum (2) and a product inlet (10) of the separator (1) open into a common inlet pipe (13). Method according to one of the preceding claims, characterized in that the volume required for filling the drum (2) is determined by a measuring device (19) for determining an inflow volume, in particular by a flow meter. Method according to one of the preceding claims, characterized in that the measuring device is arranged in or on the displacement water inlet (11). Method according to one of the preceding claims, characterized in that the generated control signal initiates an output at an output unit, preferably a warning, and/or takes immediate action on the operation of the separator, in particular initiates emptying and/or an emergency stop. Method according to one of the preceding claims, characterized in that a value for a maximum internal volume of the drum (2) is provided by a reference measurement when the condition of the drum is known, in particular after manual emptying and/or maintenance of the separator (1). . Method according to one of the preceding claims, characterized in that a value for a maximum internal volume of the drum (2) is provided by providing a value for a technical drum volume as a value for the design-related maximum internal volume of the drum (2). Method according to one of the preceding claims, characterized in that steps I and II are repeated at least twice. Method according to one of the preceding claims, characterized in that at least steps B and C, preferably the entire method, is carried out without dismantling the separator, in particular the drum. 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) with a valve (18) for the controlled introduction of displacement water into the drum (2) wherein the displacement water inlet (11) has a measuring device (19) for determining the supplied volume of displacement water until the drum (2) is filled. separator after Claim 13 characterized in that the separator has a sensor which detects the complete filling of the drum (2). separator after Claim 14 , characterized in that the separator (1) has a control and / or evaluation unit (21) which is equipped to evaluate the volume measurement of the measuring device (19) from the opening of the valve (18) to the detection of full constant filling of the drum (2) by the sensor.

Images