EP2538085A2 - Pump assembly and method - Google Patents

Abstract

The pump arrangement has a pump device (1), particularly with a centrifugal pump, where the pump device has a housing (5) with an intake opening (2), an impeller housing (3) and an outflow opening (4), a drive shaft (8) and an impeller (6) that is fixed at the drive shaft and is arranged in the impeller housing. A diagonal unit (16) is provided for determining the operating condition of the pump device and is connected with an ultrasonic transmitting- or receiving device (14) arranged nearby the intake opening or the outflow opening of the pump device. An independent claim is included for a method for determining the operating condition of a pump arrangement.

Description

The invention relates to a pump arrangement with a pumping device, in particular with a centrifugal pump, wherein the pumping device comprises a housing comprising at least one suction opening, an impeller housing part and an outflow opening, a drive shaft arranged at least partially in the housing and displaceable in a rotary movement about a rotation axis and at least one in the Impeller housing part arranged and fixed to the drive shaft impeller has.

The invention further relates to a method for determining the operating state of such a pump arrangement.

Such a pump arrangement is for example from the DE 10 2005 023 269 A1 known. An ultrasonic flow sensor mounted on the outer wall of the tube monitors the flow present during operation of the centrifugal pump. This happens because an ultrasonic signal is sent into the flowing liquid, reflected there and collected again in the sensor. A measured value formed from the signal provides information about the flow velocity. Since the flow in the pipe is influenced not only by possible blockages at the injector nozzle, but also by changes in the entire delivery area of the centrifugal pump, the flow sensor also detects disturbances elsewhere, for example in the intake area. Via a sensor cable, the flow sensor transmits the respective operating state to a display device, which in its display function A similar design is like a traffic light: Constant green light indicates perfect operation, yellow flashing light indicates a partial blockage and constant red light warns in the event of a malfunction, which may have been caused mainly by a blockage.

During operation of a generic pump arrangement, in particular on the surface of the impeller of the pump device, in particular a centrifugal pump, wear, in particular the so-called cavitation, can occur. Parts of the impeller can be deformed by the high mechanical stresses in microscopic parts. After some time, larger particles may break out of the surface, greatly reducing the efficiency of the pump.

The object of the invention is to investigate the operating state, in particular the state of wear of internal components, in particular of the impeller, without opening the pump device in order to avoid costly downtimes of the system concerned. Furthermore, a method for determining the operating state of a pump arrangement is to be created.

The object is achieved by a diagnostic unit for determining the operating state of the pumping device, wherein the diagnostic unit is connected to a near the suction port or the discharge opening of the pumping device arranged ultrasonic transmitting / receiving device.

The pump assembly thus has, in addition to the pumping device, also a diagnostic unit and an ultrasonic transmitting / receiving device. The ultrasonic transmitting / receiving device arranged near the outlet or outflow opening of the pump device can be arranged in or on the impeller housing part or in or on a component connected to the impeller housing part.

According to an embodiment of the invention, the ultrasonic transmitting / receiving device is arranged facing the impeller. This can be the Easily check points that are usually affected by signs of wear.

In a further embodiment, the ultrasonic transmitting / receiving device is arranged in or on the impeller housing part of the pumping device. By such an arrangement, the signs of wear, especially on the impeller, can be determined very well.

According to an embodiment of the invention, a voltage applied to the pumping device side of the ultrasonic transmitting / receiving device is adapted to the design of the pumping device. As a result, the ultrasonic transmitting / receiving device is located optimally on the pumping device, so that possible impurities for the ultrasonic pulses are avoided.

According to an alternative embodiment, the ultrasonic transmitting / receiving device can be inserted or screwed into an adapter part adapted to the respective design of the pump device.

So that the ultrasonic transmitting / receiving device can always be placed at the same location of the pumping device, according to the invention projections are provided on the impeller housing part of the pumping device, between which the ultrasonic transmitting / receiving device can be positioned. As a result, accurate series of examinations, even by different people, feasible.

In an alternative embodiment of the invention, a pocket is formed in the pumping device, into which the ultrasonic transmitting / receiving device can be inserted. This makes it possible to produce the ultrasonic transmitting / receiving device in one embodiment or to dispense with the adapter part.

In a further embodiment, the ultrasound transmitting / receiving device is arranged in a positive and / or non-positive fit in the pocket, whereby the handling of the diagnostic unit is further simplified.

According to an alternative embodiment, the impeller housing part has an opening into which the ultrasonic transmitting / receiving device is inserted, such that the ultrasound transmitting / receiving device is wettable by the pumped with the pumping medium. This allows a more accurate measurement. The ultrasonic waves impinge directly on the impeller and the blades arranged thereon and are also reflected directly to the media-contacting ultrasonic transmitting / receiving device without having to penetrate the impeller housing part or without reflections on the edges of the impeller housing part arising from the diagnostic unit have to be deducted again.

In this embodiment, the ultrasonic transceiver according to the invention comprises a socket into which a plug of an electrical line or a radio transmission device can be inserted in order to connect the ultrasonic transceiver to the diagnostic unit.

According to a further embodiment of the invention, a radio transmission device is integrated into the ultrasonic transmitting / receiving device, whereby the handling of the diagnostic unit is further simplified.

It has proved to be expedient if the ultrasonic transmitting / receiving device has a substantially radial extension with respect to the axis of rotation.

An advantageous embodiment with best examination results is achieved in that the ultrasonic transmitting / receiving device according to the invention comprises a plurality of probes or at least one phased array probe.

In order to obtain the lowest possible disturbing effects, the material of the pumping device has a low density, which corresponds to the density of polymers, usually from 1.1 to 2.2 g / cm ³ , and / or the material of the pumping device is a homogeneous material ,

It is advantageous if operational changes in geometry can be determined by the diagnostic unit.

It is also advantageous if quantitative and / or qualitative operational changes in geometry can be determined by the diagnostic unit.

In a preferred embodiment, the geometry changes detectable by the diagnostic unit include the wear state of the pumping device and / or a blockage occurring on the impeller and / or the proportion of solids in the conveyed fluid and / or cavitation areas and / or blockages in front of and / or on the impeller.

As a result, conclusions can be drawn as to whether or when an exchange of individual parts of the pump arrangement is necessary or may become necessary.

A method according to the invention for determining the operating state of a pump arrangement provides that the pumping device is operated at a defined rotational speed, with the ultrasonic transmitting / receiving device transmitting and receiving ultrasonic signals, the electrical signals from the ultrasonic transmitting / receiving device to the diagnostic unit on the basis of received ultrasonic signals are forwarded and information about the operating state of the pumping device is output.

Operating the pumping device at a defined or constant speed facilitates further processing of the signals in the diagnostic unit. In variable-speed operated pumping devices, it is provided to further process the signals by means of an order analysis.

It is advantageous to store pump type, type of impeller, number of blades and / or characteristic curves in a memory of the diagnostic unit.

In a further advantageous embodiment of the method, the electrical signals are triggered automatically and determines the direction of rotation and the speed of the impeller, so that the surface of a blade arranged on the impeller is hit at least once in each revolution.

Another advantageous method step is to combine the triggered signals associated with a blade.

By means of the speed information, each ultrasonic pulse can be assigned to an azimuth related to an arbitrarily selected radial axis. The radial extent of the phased array includes the radial assignment. Assuming that during some revolutions of the wear of the impeller does not change much, with a sufficiently short pulse duration already a sampling frequency below the rotational frequency is sufficient to scan the impeller. In contrast, with a sampling frequency which is a multiple of the rotational frequency, the impeller can be sampled in real time.

With high-resolution and sufficiently accurate signals from the blades or with the aid of a unique mark, such as a balancing mark, depression, increase, type designation, material designation or the like, be closed on the impeller via a frequency analysis on the number of blades, rotational frequency and direction of rotation.

In a further embodiment of the method, the combined signals are compared with the data stored in the memory.

Another advantageous method step is that the diagnostic unit determines operational geometry changes.

Another advantageous method step is that the diagnostic unit determines quantitative and / or qualitative operational changes in geometry.

In a particularly advantageous embodiment of the method, the diagnostic unit determines the state of wear of the pumping device and / or a blockage occurring on the impeller and / or the proportion of solids in the conveyed fluid and / or Kavitationsbereiche and / or Verockerungen before and / or on the impeller.

As a result, it can be determined whether the impeller or the pumping device must be replaced immediately or how long the components can still be operated in the system.

In a further embodiment of the method, it is provided that an optical representation of the rotor state is carried out by the diagnostic unit.

In a preferred embodiment of the method is carried out by the diagnostic unit, an optical representation of the state of the impeller in a three-dimensional representation, which results, advantageously, an exact damage pattern of the impeller.

Fig. 1

eine Pumpenanordnung für ein strömungsführendes System mit einer Pumpvorrichtung und einer an einem Laufradgehäuseteil der Pumpvorrichtung positionierten Ultraschall-Sende-/Empfangsvorrichtung sowie einer daran angeschlossenen Diagnoseeinheit, die

Fig. 1a

eine Ausführungsform der Ultraschall-Sende-/Empfangsvorrichtung, die

Fig. 2

eine Pumpenanordnung gemäß Fig.1 mit einer mittels Vorsprüngen an einem Laufradgehäuseteil der Pumpvorrichtung positionierten Ultraschall-Sende-/Empfangsvorrichtung, die

Fig. 3

eine Pumpenanordnung gemäß Fig.1 mit einer in einer Tasche angeordneten Ultraschall-Sende/Empfangsvorrichtung, die

Fig. 4

eine Pumpenanordnung gemäß Fig.1 mit einer speziellen Ausführungsform der Ultraschall-Sende/Empfangsvorrichtung, die

Fig. 5

eine Pumpenanordnung gemäß Fig.1 mit einer weiteren Ausführungsform der Ultraschall-Sende/Empfangsvorrichtung, die

Fig. 6

eine Pumpenanordnung gemäß Fig.1 mit einer in einer Öffnung der zum Innenraum des Laufradgehäuseteils angeordneten Ultraschall-Sende/Empfangsvorrichtung, die

Fig. 7

eine schematische Darstellung der Anordnung der Ultraschall-Sende-/Empfangsvorrichtung zum Laufrad in der Pumpvorrichtung gemäß Fig. 3, die

Fig. 8

eine Momentaufnahme eines gemäß der Anordnung aus Fig. 7 erzeugten Signals und die

Fig. 9

einen gemäß der Anordnung aus Fig. 7 erzeugten Signalverlauf, eines Punktes der Ultraschall-Sende-/Empfangsvorrichtung.

Embodiments of the invention are illustrated in the drawings and will be described in more detail below. It shows the

Fig. 1

a pump assembly for a flow-carrying system having a pumping device and an ultrasonic transmitting / receiving device positioned on an impeller housing part of the pumping device and a diagnostic unit connected thereto

Fig. 1a

an embodiment of the ultrasonic transmitting / receiving apparatus, the

Fig. 2

a pump assembly according to Fig.1 with an ultrasonic transmitting / receiving device positioned by means of projections on an impeller housing part of the pumping device, the

Fig. 3

a pump assembly according to Fig.1 with an ultrasonic transmitting / receiving device arranged in a pocket, the

Fig. 4

a pump assembly according to Fig.1 with a specific embodiment of the ultrasonic transmitting / receiving device, the

Fig. 5

a pump assembly according to Fig.1 with a further embodiment of the ultrasonic transmitting / receiving device, the

Fig. 6

a pump assembly according to Fig.1 with an in an opening of the interior of the impeller housing part arranged ultrasonic transmitting / receiving device, the

Fig. 7

a schematic representation of the arrangement of the ultrasonic transmitting / receiving device to the impeller in the pumping device according to Fig. 3 , the

Fig. 8

a snapshot of one according to the arrangement Fig. 7 generated signal and the

Fig. 9

one according to the arrangement Fig. 7 generated waveform, a point of the ultrasonic transmitting / receiving device.

In Fig. 1 a pump assembly for a flow-carrying system is shown with a pumping device 1 in the form of a centrifugal pump, wherein the pumping device 1 comprises at least one with a suction port 2, an impeller housing part 3 and an outflow opening 4 having housing 5, wherein with the pumping device 1 a within the flow System is affected medium. The promotion of the medium takes place with an impeller 6, which is fixed to a first shaft end 7 of a drive shaft 8. At the suction opening 2 side facing the impeller 6, a plurality of blades 9 are formed, which are connected to a cover plate 10. To drive the drive shaft 8, a motor, not shown, with a first shaft end 7 opposite the second shaft end 11 of the drive shaft 8 is connected in a known manner.

Via a pipe 12 belonging to the flow-guiding system, the medium enters the pump device 1 through the suction opening 2 arranged in a rotation axis A and is accelerated by the rotating impeller 6. By the action of the centrifugal force, the medium flows from the rotation axis A radially outward into the impeller housing part 3 and from there via the outflow opening 4 into a pipe 13 of the flow-carrying system. On the side facing away from the intake 2 side of the impeller housing part 3 and the drive shaft 8 side facing a simplified ultrasonic transmitting / receiving device 14 is brought into abutment over one, one or more conductors or wires having electrical line 15 with a diagnostic unit 16 connected or connectable.

Advantageously, an applied to the pumping device 1 side of the ultrasonic transmitting / receiving device 14 is adapted to the design of the impeller housing part 3. It is also within the scope of the invention to design one or more locations suitable for the examination on the impeller housing part 3 in such a way that a flat or polished surface is formed, against which the ultrasound transceiver 14 is positioned. Alternatively, as in Fig. 1a represented, adapted to the respective design adapter part 17 are used, in which the ultrasonic transmitting / receiving device 14 is inserted or screwed.

At the in Fig. 2 1, projections 18 are provided on the impeller housing part 3 of the pumping device 1, between which the ultrasonic transmitting / receiving device 14 connected to the diagnostic unit 16 via the electrical line 15 can be positioned on the pumping device 1. In a particularly favorable embodiment of the projections 18, two projections are sufficient. These may have a recess adapted to the side surface or side surfaces, depending on whether the ultrasound transceiver 14 is round or quadrangular, for example, so that a projection 18 is a side surface of a round ultrasonic transceiver 14 or two side surfaces a quadrangular ultrasonic transceiver 14 at least partially surrounds. Other suitable shapes for the projections 18 are also within the scope of the invention.

The Fig. 3 shows a pump assembly, in which the pumping device 1, an impeller 6 without the in the Fig. 1 has shown cover plate. In the suction opening 2 facing side of the impeller housing part 3, a pocket 19 is formed, in which the connected via the electrical line 15 to the diagnostic unit 16 ultrasonic transmitting / receiving device 14 is used. The sound cone emitted from the ultrasonic transmitting / receiving device 14 is defined by the boundary lines a and b.

While in the FIGS. 1 to 3 the suction openings 2 are arranged substantially coaxially to the axis of rotation A and the outflow openings 4 are arranged radially or essentially perpendicular to the axis of rotation A, are in Fig. 4 and 5 both the suction openings 2 and the outflow openings 4 are arranged radially or substantially perpendicular to the axis of rotation A of the pump device 1. On the side facing away from the drive shaft 8, a pocket 19 is formed in the impeller housing part 3, in which the ultrasonic transmitting / receiving device 14 is arranged positively and / or non-positively. For example, the ultrasonic transceiver 14 may be secured in the pocket 19 by adhesive. Other suitable means for non-detachable connection of the ultrasonic transmitting / receiving device 14 with the impeller housing part 3, for example by a press fit, are also provided. A permanent arrangement of the ultrasonic transmitting / receiving device 14 in the pocket 19 can also be realized via a screw connection. The ultrasonic transmitting / receiving device 14 has a socket 20, in which a plug 21 of the electrical line 15 can be inserted in order to connect the ultrasonic transmitting / receiving device 14 with the diagnostic unit 16. In Fig. 4 The ultrasonic transmitting / receiving device 14 transmits its ultrasonic waves substantially obliquely to the drive shaft 8 in order to detect a specific point of the impeller 6.

Out Fig. 5 It can be seen that the ultrasonic transmitting / receiving device 14 is arranged substantially coaxially with the axis of rotation A, to detect the impeller 6 at another location or from another angle. According to the invention, it is provided that the connection of diagnostic unit 16 and ultrasound transceiver 14 takes place via an insertable into the socket 20 radio transmission device 22.

The fact that the radio transmission device is integrated in the ultrasonic transmitting / receiving device 14 is also within the scope of the invention.

The Fig. 6 shows a pumping device 1 in the embodiment of a tubular casing pump, in which the ultrasonic transmitting / receiving device 14 is arranged in a formed on the impeller housing part 3 swirl cup 23 and is directly in communication with the interior of the impeller housing part 3. The swirl cup 23 has an opening 24 into which the ultrasound transceiver 14 is inserted. The ultrasound transmitting / receiving device 14 is wettable by the pumped with the pumping device 1 medium. Due to the absence of a reflection generating wall, a more accurate measurement is possible. The ultrasonic waves impinge directly on the impeller 6 and the blades 9 arranged thereon and are likewise reflected directly to the ultrasonic transmitting / receiving device 14, without having to penetrate the impeller housing part 3 or without reflections occurring at the edges of the impeller housing part 3, which must be removed from the diagnostic unit 16 again.

The Fig. 7 shows by way of example that the ultrasonic transmitting / receiving device 14 with respect to the axis of rotation A preferably has a substantially radial extent in order to be able to detect the relevant points, that is, the most heavily stressed points on the impeller 6 with its blades 9. To explain the operation, the individual blades are provided with the reference numerals 9a to 9g.

Fig. 8 shows a snapshot of a signal generated by at least two probes of the ultrasonic transmitting / receiving device 14, as shown in the Fig. 6 shown arrangement of the blades 9a and 9g on impeller 6 and the ultrasonic transmitting / receiving device 14 is generated. In this case, pulse 9a 'correlates with blade 9a and pulse 9g' with blade 9g.

The FIG. 9 shows the generated by a probe of the ultrasonic transmitting / receiving device 14 waveform at the rotating, in Fig. 6 The height of the individual pulses depends on the distance between the blades 9a to 9g, which are of equal height without wear, to the ultrasonic transmitting / receiving device 14. The smaller the distance of the blade from the ultrasonic transmitting / receiving device 14, the higher the pulse height and the lower the wear. Different pulse heights indicate a different wear of the individual blades 9a to 9g. Also is off Fig. 9 It can be seen that the distance between the pulse signals 9d and 9e is slightly less than the distance between the other pulses. This indicates an irregularity in the impeller 6 out.

If the ultrasound transceiver 14 comprises a plurality of probes or at least one so-called phased array probe, the diagnostic unit 16 can quantitatively and / or qualitatively determine operational geometry changes, in particular the state of wear of the pump device 1 and / or a blockage occurring on the impeller 6 and / or the proportion of solids in the pumped fluid and / or Kavitationsbereiche and / or Verockerungen before and / or on the impeller without the pumping device 1 must be dismantled or removed from the flow-leading system and expensive downtime incurred.

The emitted sound pulses are partially reflected by the inner wall of the housing 5, more precisely by the impeller housing part 3, partly the sound pulses reach the impeller 6 via the conveyed medium and are transmitted to the test heads or the at least one phased array test head of the ultrasound transmitter. / Receiving device 14 reflected. In this case, the pulse repetition frequency is chosen so that each area of the surface of the rotating impeller 6 is hit at least once by the one or more emitted sound pulses at each revolution. The emitted pulse frequency is in this case many times higher than the rotational frequency of a point on or on the impeller 6 or the blades 9 and 9a to 9g connected to the impeller. The corresponding signals are further processed in the diagnostic unit 16 and used for generating a three-dimensional image on a monitor integrated in the diagnostic unit 16.

By a suitable evaluation, for example phase shift or Doppler effect, the direction of rotation and the speed can be determined.

The best results can be achieved if the material of the pumping device 1 has a different but not too different density from the pumped medium, which is the case for most polymers with densities of usually 1.1 to 2.2 g / cm ³ , and if the material is a homogeneous material.

LIST OF REFERENCE NUMBERS

1

pumping device

2

suction

3

Impeller housing part

4

outflow

5

casing

6

Wheel

7

first wave end

8th

drive shaft

9

shovel

10

cover disc

11

second shaft end

12

pipeline

13

pipeline

14

Ultrasonic transmitting / receiving device

15

electrical line

16

diagnostic unit

17

adapter part

18

head Start

19

bag

20

Rifle

21

plug

22

Radio transmission device

23

swirl cup

24

opening

A

axis of rotation

a

boundary line

b

boundary line

Claims (27)

Pump arrangement with a pumping device (1), in particular with a centrifugal pump, wherein the pumping device (1) comprises a housing (5) comprising at least one suction opening (2), an impeller housing part (3) and an outflow opening (4), one at least partially in the housing (5) arranged and about a rotational axis (A) in a rotational movement displaceable drive shaft (8) and at least one in the impeller housing part (3) arranged and on the drive shaft (8) fixed impeller (6),
marked by
a diagnostic unit (16) for determining the operating state of the pump device (1), the diagnostic unit (16) having an ultrasonic transmitting / receiving device (14) arranged near the suction opening (2) or the outflow opening (4) of the pump device (1) connected is. Pump arrangement according to claim 1, characterized in that the ultrasonic transmitting / receiving device (14) facing the impeller (6) is arranged. Pump arrangement according to claim 1 or 2, characterized in that the ultrasonic transmitting / receiving device (14) in or on the impeller housing part (3) of the pumping device (1) is arranged. Pump arrangement according to one of claims 1, 2 or 3, characterized in that on the pumping device (1) adjacent side of the ultrasonic transmitting / receiving device (14) is adapted to the design of the pumping device (1). Pump arrangement according to one of claims 1 to 4, characterized in that the ultrasonic transmitting / receiving device (14) in an adapted to the respective design of the pump device (1) adapter part (17) can be inserted or screwed. Pump arrangement according to one of claims 1 to 5, characterized in that on the impeller housing part (3) of the pumping device (1) projections (18) are provided, between which the ultrasonic transmitting / receiving device (14) can be positioned. Pump arrangement according to one of claims 1 to 6, characterized in that in the pumping device (1) a pocket (19) is formed, in which the ultrasonic transmitting / receiving device (14) can be inserted. Pump arrangement according to claim 7, characterized in that the ultrasonic transmitting / receiving device (14) is arranged positively and / or non-positively in the pocket (19). Pump arrangement according to claim 1, 2 or 3, characterized in that the impeller housing part (3) has an opening (24) into which the ultrasonic transmitting / receiving device (14) is inserted, such that the ultrasonic transmitting / receiving device (14) is wettable by the pumped with the pumping device (1) medium. Pump arrangement according to one of claims 1 to 9, characterized in that the ultrasonic transmitting / receiving device (14) has a socket (20) into which a plug (21) of an electrical line (15) or a radio transmission device (22) can be inserted is to connect the ultrasonic transmitting / receiving device (14) with the diagnostic unit (16). Pump arrangement according to one of claims 1 to 9, characterized in that a radio transmission device (22) in the ultrasonic transmitting / receiving device (14) is integrated. Pump arrangement according to one of claims 1 to 11, characterized in that the ultrasonic transmitting / receiving device (14) with respect to the axis of rotation (A) has a substantially radial extent. Pump arrangement according to one of claims 1 to 12, characterized in that the ultrasonic transmitting / receiving device (14) comprises a plurality of probes or at least one phased array probe. Pump arrangement according to one of claims 1 to 13, characterized in that the material of the pumping device (1) has a low density or is a homogeneous material. Pump arrangement according to one of claims 1 to 14, characterized in that by the diagnostic unit (16) operational geometry changes can be determined. Pump arrangement according to claim 15, characterized in that by the diagnostic unit (16) operational geometry changes can be determined quantitatively and / or qualitatively. Pump arrangement according to one of claims 15 or 16, characterized in that the detectable by the diagnostic unit (16) geometry changes the state of wear of the pumping device (1) and / or on the impeller (6) occurring blockage and / or the proportion of solids in the pumped fluid and / or cavitation areas and / or cavities before and / or on the impeller (6). Method for determining the operating state of a pump arrangement according to one of Claims 1 to 11, having the following steps: Operating the pumping device (1) at a defined speed, Transmitting and receiving ultrasonic signals with the ultrasonic transceiver (14), Forwarding electrical signals from the ultrasound transceiver (14) to the diagnostic unit (16) based on the received ultrasound signals, Outputting information about the operating state of the pumping device (1). A method according to claim 18, characterized in that the pump type, type of impeller, number of blades and / or characteristics are stored in a memory of the diagnostic unit (16). A method according to claim 18 or 19, characterized in that the electrical signals are triggered automatically and the direction of rotation and the rotational speed of the impeller (6) are determined. A method according to claim 20, characterized in that the triggered, a blade (9a to 9g) associated signals are combined. A method according to claim 21, characterized in that the combined signals are compared with the data stored in the memory. Method according to one of claims 18 to 22, characterized in that the diagnostic unit (16) determines operational geometry changes. A method according to claim 23, characterized in that the diagnostic unit (16) determines quantitative and / or qualitative operational changes in geometry. Method according to one of claims 23 or 24, characterized in that the diagnostic unit (16) the state of wear of the pumping device (1) and / or on the impeller (6) occurring blockage and / or the proportion of solids in the conveyed fluid and / or Kavitationsbereiche and / or Verockerungen before and / or on the impeller (6) determined. Method according to one of claims 18 to 25, characterized in that by the diagnostic unit (16) an optical representation of the operating state takes place. A method according to claim 26, characterized in that the optical representation of the operating state takes place in a three-dimensional representation.

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