EP2172654B2 - Centrifugal pump assembly - Google Patents

Abstract

The aggregate has a suction inlet (4) provided on an inlet side of an impeller, and a pressure outlet (12) provided at an outlet side of the impeller. A vortex flow sensor and a guide element are arranged in a pipeline segment formed by the suction inlet and/or the pressure outlet. The guide element controls flow through the pipeline segment. The guide element is formed as a rib (22) inwardly protruding from an inner wall (26) of the pipeline segment. The rib extends in a flow direction (S) of a fluid along the inner wall.

Description

The invention relates to a centrifugal pump unit with the features specified in the preamble of claim 1.

Such centrifugal pump units are used for example as Heizungsumwölzpumpen. In many cases, such pumps are used in systems in which the flow through the lines is determined to be taken into account in the control and / or regulation of the system. This is the case, for example, in heating systems, in which the flow through the pump or an adjacent pipeline is determined. For this purpose, flow sensors are arranged in the pipelines.

US 5,129,264 shows a generic centrifugal pump, in which several pressure sensors are arranged in the discharge nozzle. By means of these pressure sensors, pressure values are detected which, given a known design of the pump, are suitable for detecting the flow on account of the pressure differences occurring at different points of the pump.

The from the document US 5,129,264 Features known in conjunction with each other are summarized in the preamble of the independent claim.

It is an object of the invention to simplify the arrangement of a pump unit and a flow sensor. This object is achieved by a centrifugal pump unit having the features specified in claim 1. Preferred embodiments will become apparent from the dependent claims, the following description and the figures.

The inventive centrifugal pump unit has in a known manner at least one impeller and an inlet side of the impeller located suction nozzle and an output side of the impeller located pressure nozzle. Suction nozzle and discharge nozzle end at their free ends facing away from the impeller in a known manner, preferably in a flange which allows connection to adjacent pipes.

According to the invention, a flow sensor is integrated into this centrifugal pump unit. The flow sensor is arranged in a line section of the centrifugal pump assembly. This may be a conduit section in the suction port or a conduit section in the discharge port. Alternatively, it is also possible that in each case a flow sensor is arranged both in the discharge nozzle and in the suction nozzle.

Since in the suction and discharge nozzles of a centrifugal pump unit turbulence in the flow arise, which are caused by the impeller, the flow measurement with known flow sensors in the areas of suction and discharge nozzles is not readily possible. Usually, a certain minimum distance between impeller and flow sensor must be maintained, which is not available in a pump unit of conventional design. For this reason, at least one guide element is provided according to the invention, which is arranged in the line section, in which the flow sensor is arranged. In this case, the guide element is suitable for influencing the flow prevailing in the line section. Thus, the guide element can influence the flow so that the measurement result of the flow sensor is not or only insignificantly influenced by the turbulence in the suction nozzle or discharge nozzle. The guide element is thus preferably designed so that it keeps disturbing turbulence of the flow sensor.

This is particularly advantageous since the flow sensor is a vortex flow sensor. In such a flow sensor, an obstruction is arranged in the flow, which causes turbulence in the flow, which are then detected by measurement by means of a pressure sensor. From the frequency of the vortex flow velocity can be determined. It should be understood that such a sensor would be severely affected by turbulence or turbulence in the flow in its measurement result. For this reason, the guide element according to the invention is provided which influences the flow in the line section in which the sensor is arranged in such a way that disturbing turbulences or turbulences which could falsify or impair the measurement result are kept away from the sensor.

The at least one guide element is therefore preferably suitable for calming the flow prevailing in the line section in which the flow sensor is arranged. Thus, especially in the area of a vortex flow sensor, ideally only such vortices are caused, which are caused by its obstruction, but not turbulences or turbulences which result from the operation of the impeller.

According to a possible embodiment, the at least one guide element is designed as a rib projecting inwards from the inner wall of the line section. Such a rib is particularly suitable for damping or suppressing rotating flows in the line section, since such a rib opposes such a flow. In the event that the line section of the suction and / or pressure port is curved, such a rib on the inner wall of the conduit section is preferably arranged on the outer side of the curvature, ie on the concavely curved inner wall or the inner wall with a larger radius of curvature.

Particularly preferably, the rib is designed such that it extends in the flow direction of a fluid to be conveyed along the inner wall of the line section. Thus, the flowing in the flow direction parallel to the longitudinal axis of the line section Strö determination is little influenced by the rib, rotating currents, however, provides the rib a significant resistance, so that such currents or turbulence in the line section are attenuated or suppressed. In this way, disturbances that affect the measurement result of the flow sensor are reduced.

In the case that the flow sensor is arranged in the suction nozzle, the rib preferably extends between the flow sensor and the impeller. In the event that a vortex flow sensor is provided, the rib preferably extends from its obstruction into a region of curvature of the suction nozzle. Such a rib may be integrally formed on the inner wall of the line section or used as a separate component in the line section. Thus, the rib may be formed as an insert or part of an insert, which is inserted into the line section, for example, the suction nozzle. Such an insert may preferably be formed of plastic.

Further, it is preferable that a sensor of the flow sensor is disposed in the rib. This applies in particular to the design of the sensor as a vortex flow sensor. In this case, the pressure sensor, which detects the turbulence caused by the obstruction, can be arranged in the rib. In this way, the flow resistance caused by the rib and the pressure sensor in the line section is minimized.

Preferably, the sensor has two pressure transducer surfaces and is arranged in the rib such that the two Druckaufnehmerflöchen are each connected to one side of the rib for pressurizing. In particular, a differential pressure between both sides of the rib can be detected by the sensor. The pressure transducer surfaces may be directly formed as a pressure-receiving membrane on or in the surfaces of the rib. Alternatively, it is also possible that in the surfaces of the rib only openings are formed, which are connected via channels with a more inwardly located or possibly outside of the line section sensor.

According to a further preferred embodiment, at least one recess for receiving the measuring sensor can be formed in the rib. This makes it possible to insert a sensor designed as a separate component in such a recess. Thus, rib and probe can be made separately, but used in the line section cooperate so that overall the flow resistance in the longitudinal direction of the line section is minimized. Particularly preferably, the measuring sensor is inserted from the outside through an opening in the line section, so that a free end of the measuring probe extends into the line section. In the previously described embodiment of the rib, the free end of the probe then extends into the recess in the rib. Such an arrangement makes it possible to exchange the sensor easily from the outside.

Instead of providing a sensor which projects into the interior of the line section or is arranged in the interior of the line section, the line section can also have outwardly leading openings or channels, which make it possible to arrange the sensor outside the line section and the flow path defined by this. In this way, the flow inside the line section is even less affected, and the mounting or accessibility of the flow sensor can be improved.

The rib arranged in the line section preferably has a rounded or triangular cross section transverse to the flow direction. Thus, a great stability in the circumferential direction of the line section is realized. The rounded configuration achieves an optimized flow guidance along the rib.

Alternatively or additionally, the at least one guide element may be formed as at least one profile plate projecting inwardly from the inner wall of the line section, which profile is oriented transversely to the flow direction of a fluid to be delivered. That is, such a profile plate opposes the flow along the longitudinal axis of the line section. Such a profile plate thus represents a certain flow resistance in the line section. Such a profile plate in the line section serves to prevent unwanted turbulences or turbulences in the flow direction from being able to propagate unhindered in the line section. The profile plate brakes or prevents propagation of turbulences, which emanate from the impeller and propagate in the longitudinal direction of the line section in this opposite to the flow direction.

In the event that additionally a rib is provided, as described above, the profile plate preferably extends transversely to the rib and more preferably symmetrically to the median plane of the rib. The hot, rib and profile plates intersect each other, with the rib penetrating the profile plate at its centerline.

It is preferred that the profile plate, starting from the inner wall of the conduit section, extends further inwardly into the conduit section than the rib. That is, in the radial direction, the profile plate protrudes from the inner wall of the line section over the upper edge of the rib.

Furthermore, it is preferred that the profile plate is inclined, starting from the inner wall in the flow direction of the fluid to be delivered. In this way, the flow resistance in the flow direction of the fluid is reduced by the line section which forms the profile plate. Preferably, this arrangement is in the case that the flow sensor is located in the suction nozzle. Turbulences, which are caused by the impeller, propagate in the suction nozzle counter to the flow direction in the longitudinal direction of the suction nozzle. In order to brake this propagation of turbulences against the flow direction, at least one profile plate described can be arranged in the suction nozzle. If the profile plate is inclined in the flow direction, the flow resistance is reduced in the flow direction, the propagation of the turbulence against the flow direction, however, opposes such profile plate. Facing the impeller, the profile plate thus forms a kind of pocket in which such turbulences are damped or braked.

The at least one profile plate is preferably arranged behind a measuring sensor of the sensor in the flow direction of the fluid to be delivered. This applies in particular to the arrangement of the sensor in the suction nozzle of the pump unit. This arrangement causes the profile plate does not affect the flow of the sensor through the fluid, since it is located only downstream of the sensor. On the other hand, the profile plate can thus brake the propagation of turbulence caused by the impeller against the flow direction, so that these turbulences do not reach the sensor or at least in a weakened form, so that the disturbances that would affect the measurement result of the sensor to be minimized.

It is particularly preferred to provide a plurality of profile plates, which are arranged spaced apart in the flow direction in the line section. In this way, an even greater attenuation of propagating in the line section turbulence or turbulence is achieved. The plurality of profile plates are preferably all inclined in the flow direction, wherein preferably all profile plates have the same angle of inclination to the inner wall of the line section. In this way, a particularly uniform flow guidance is achieved in the flow direction.

The flow sensor is preferably located at the end of the conduit portion spaced from the impeller, preferably with an obstruction of the flow sensor located at the end of the suction port spaced from the impeller. The obstruction may be formed, for example, in an insert which is inserted from the open end into the suction nozzle, so that the obstruction is located at the end of the suction. In this case, the insert may also extend in the manner described above beyond the axial end of the suction nozzle, so that it can enter into a subsequent pipeline. In this embodiment, it is also possible to arrange the obstruction even further outside the suction nozzle in the insert, so that it is located in a pipe adjacent to the suction pipe. In this way, a greater distance between the obstruction and the impeller can be achieved without having to increase the length of the Saugstutzens. Alternatively, it is also possible to form the obstruction integrally with the suction nozzle or to use the obstruction through an opening in the wall of the suction nozzle in the radial direction in the cross section of the suction nozzle. The obstruction preferably extends in the diameter direction through the entire cross section of the suction nozzle. Alternatively, it is also possible to form an obstruction so that it does not extend in the diameter direction over the entire cross section of the suction nozzle, d. H. in the diameter direction has a length which is less than the inner diameter of the suction nozzle at the position of the obstruction. The opening into which the obstruction is used, for example, be an existing opening for pressure detection, so that even in an existing centrifugal pump unit such obstruction can be used. Due to the position at the axial inlet end of the suction nozzle, the greatest possible distance between obstruction and impeller is achieved.

According to a particular embodiment, a tubular or tubular insert may be provided at the free end of the suction nozzle, which is inserted into the suction nozzle, so that it protrudes from the end into the suction nozzle. Moreover, the insert extends beyond the free end of the suction nozzle such that it can enter an adjacent pipe when the suction nozzle is connected to this pipe. In this way, the use of an optimized flow guidance in the transition or connection area of pipe performance and suction is achieved. The insert rests against the inner wall of the suction nozzle and adjacent pipeline. The insert is preferably elastic, so that it can compensate for a small offset between the pipe and suction. Incidentally, it bridges the flange or connecting region, so that edges or undercuts, at which swirling could occur, are avoided and thus a flow sensor placed in the inlet region of the suction nozzle can be flown as optimally as possible.

Fig. 1

einen Querschnitt durch ein Pumpengehäuse entlang der Mittelebene des Saugstutzens mit einer in dem Saugstut- zen angeordneten Rippe,

Fig. 2

eine Schnittansicht entsprechend der Ansicht in Fig. 1 mit einer in dem Saugstutzen angeordneten Rippe gemäß ei- ner zweiten Ausführungsform,

Fig. 3

einen Querschnitt durch ein Pumpengehäuse entlang der Mittelebene des Saugstutzens mit darin angeordneten Profil-Platten,

Fig.4

eine Schnittansicht entsprechend der Ansicht in Fig. 3, wobei zusätzlich zu den Profil-Platten eine Rippe in dem Saugstutzen angeordnet ist,

Fig. 5

eine Ansicht entsprechend von Fig. 1, wobei zusätzlich eine mögliche Anordnung eines Messelementes gezeigt ist,

Fig. 6

eine Schnittansicht eines Pumpengehäuses entlang der Mittelebene des Saugstutzens mit einer zweiten mögli- chen Anordnung eines Messelementes,

Fig. 7

eine Schnittansicht eines Pumpengehäuses entlang der Mittelebene des Saugstutzens mit einer zweiten Ausfüh- rungsform einer Obstruktion,

Fig. 8

eine Schnittansicht eines Pumpengehäuses entlang der Mittelebene des Saugstutzens mit einer dritten Ausfüh- rungsform einer Obstruktion und

Fig. 9

eine Schnittansicht eines Pumpengehäuses entlang der Mittelebene des Saugstutzens mit angrenzender Rohrlei- tung und einem in dem Verbindungsbereich eingesetzten Einsatz.

The invention will now be described by way of example with reference to the accompanying drawings. In these shows:

Fig. 1

a cross section through a pump housing along the center plane of the suction nozzle with a rib arranged in the Saugstut-,

Fig. 2

a sectional view corresponding to the view in Fig. 1 with a rib arranged in the suction nozzle according to a second embodiment,

Fig. 3

a cross section through a pump housing along the center plane of the suction with profiled plates arranged therein,

Figure 4

a sectional view corresponding to the view in Fig. 3 wherein, in addition to the profile plates, a rib is arranged in the suction nozzle,

Fig. 5

a view corresponding to Fig. 1 , wherein additionally a possible arrangement of a measuring element is shown,

Fig. 6

3 a sectional view of a pump housing along the center plane of the suction nozzle with a second possible arrangement of a measuring element,

Fig. 7

3 a sectional view of a pump housing along the mid-plane of the suction nozzle with a second embodiment of an obstruction,

Fig. 8

a sectional view of a pump housing along the mid-plane of the suction nozzle with a third embodiment of an obstruction and

Fig. 9

a sectional view of a pump housing along the center plane of the suction nozzle with adjacent pipeline and an insert used in the connection area.

With reference to the mentioned figures, preferred embodiments of the inventions will be explained below. The same reference numerals are used for identical components in the individual figures, and only the differences are explained in detail. Each of the figures shows in each case a sectional view through a pump housing 2 along the center plane of the suction nozzle 4. This center plane extends along the longitudinal axis of the suction nozzle 4, ie. H. the flow direction of a fluid to be delivered. The cross section also extends in the diameter direction through the receiving space 6 of the pump housing 2, in which a not shown impeller of the pump is arranged. At the suction nozzle 4 side facing away from the receiving space 6, a connecting flange 8 is formed for connecting a drive motor.

The suction nozzle 4 terminates at its end facing away from the receiving space 6 and thus the impeller axial end in a flange 10. Correspondingly terminates at the diametrically opposite side of the pump housing 2 of the discharge nozzle 12 in a flange fourteenth

According to the invention, a flow sensor is integrated in the pump housing 2, which as a vortex flow sensor, d. H. is formed as a flow sensor based on the Karman phenomenon of vortex shedding. This flow sensor has, as an essential element, an obstruction 16, which causes eddies in the flow, the frequency of which is detected by a pressure sensor. The frequency of the vortex is proportional to the flow velocity.

A first embodiment of such an obstruction 16 is in the FIGS. 1 to 6 shown. There, the obstruction is arranged at that axial end of the suction nozzle 4, which is facing away from the receiving space 6 and thus the impeller, ie close to or in the flange 10. The obstruction 16 is preferably triangular in cross section (not shown here) and extends in the diameter direction across the suction nozzle. 4

To evaluate the vortices caused by the obstruction 16, either a sensor 18 can be arranged so that it extends into the suction nozzle 4, as in Fig. 5 shown, or it may be a sensor outside the suction nozzle 4 are arranged. For such an arrangement, as in Fig. 6 shown, in the wall of the suction nozzle 4, a channel 20 or possibly a plurality of channels 20 are provided, which extend from the inside of the suction nozzle 4 to the outside and allow an array of sensors on the outside of the suction nozzle 4. In the FIGS. 1 to 4 and FIGS. 7-9, the probes are not shown, but it should be understood that a sensor 18 or channel 20 is also included in these embodiments as shown in FIGS FIGS. 5 or 6 shown manner is arranged.

The arrangement of the flow sensor and in particular the sensor 18 in the pump housing 2 is associated with the problem that the measurement result can be affected by turbulence caused by the rotating impeller in the receiving space 6. In order to minimize these disturbances, here the suction nozzle 4, guide elements are arranged in the line section in which the flow sensor is formed.

A first such guide element is in Fig. 1 shown. There is a rib 22 can be seen, which extends from the inner wall of the suction nozzle 4 radially inwardly. In this case, the rib 22 extends in the longitudinal direction of the suction nozzle 4 web-shaped on the inner wall of the suction nozzle 4 along. The rib is preferably rounded or triangular in cross-section, not shown here, so that it allows optimized flow guidance in the longitudinal direction of the suction nozzle 4 with sufficient stability. The rib 22 extends in the suction nozzle 4 into the curvature region, in which the suction nozzle 4 curves towards the receiving space 6. In the in Fig. 1 In the example shown, the rib 22 starts in the flow direction spaced behind the obstruction 16. In the embodiment according to Fig. 2 The rib 22 extends to the obstruction 16 zoom. The rib 22 causes in particular rotating flows or turbulences are damped in the interior of the suction nozzle 4, whereby the measurement result of the flow sensor is improved. Such turbulences can propagate from the impeller in the receiving space 6 counter to the flow direction S in the intake 4 to the flow sensor or its obstruction 16 out. The rib 22 minimizes such turbulence.

The FIGS. 3 and 4 show the arrangement of another possible guide element in the form of two profile plates 24. The profile plates 24 extend transversely to the flow direction S, starting from the inner wall of the suction nozzle 4 into the suction. Thus, the profile plates 24 extend in a direction transverse to the extending direction of FIG FIGS. 1 to 2 explained rib 22. In the embodiments shown here, two profile plates 24 are provided spaced apart in the flow direction S to each other. The profile plates 24 extend at an angle to the inner wall 26 of the suction nozzle 4. In this case, both profile plates 24 extend substantially at the same angle to the inner wall 26. The inclination of the profile plates 24 is selected so that they in the flow direction S are inclined, ie they move away from the inner wall 26 in the flow direction S farther and farther from the inner wall 26. The profile plates 24 serve to a progression of turbulence or turbulence against the flow direction S starting from the impeller, which in the receiving space 6 is arranged to prevent or damp, so that the flow in the region of the flow sensor, ie the obstruction 16 and the sensor 18 and the channel 20 is calmed and so the measurement result is not affected by turbulence caused by the impeller. Thus, the profile plates 24 are arranged in the flow direction between the sensor 18 and the channel 20 and the receiving space 6.

Fig. 4 shows a combination of the profile plates 24 with the above-described rib 22. Here, the rib 22 cuts the profile plates 24 normal to the surface of the profile plates 24. The profile plates 24 are preferably formed so that they to the median plane of the rib 22 are symmetrical. Starting from the inner wall 26, the profile plates 24 extend further into the interior of the suction nozzle 4 as the rib 22nd

If two profile plates 24 are shown in the example shown here, it should be understood that the invention is not limited to the arrangement of two such profile plates, it could also be just one profile plate 24 or more than two profile plates 24 are arranged. Also, it should be understood that the rib 22 in the embodiment according to Fig. 4 according to the embodiment in Fig. 2 could be trained.

As in Fig. 5 shown, the sensor 18 may be inserted from the outside through the wall of the suction nozzle 4 so that its free end 28 protrudes into the interior of the suction nozzle 4. At the free end of the sensor 28 there are pressure-receiving surfaces or pressure-receiving regions 30, via which the pressures or pressure changes caused by the vortices in the interior of the suction nozzle 4 are absorbed. In this case, pressure transducer surfaces are preferably formed on two opposite sides of the free end 28, so that the pressures on two sides of the probe 18 can be detected. The sensor 18 is arranged with its free end 28 in the rib 22 so that its two sides with their respective Druckaufnehmerflächen 30 each one of the sides of the rib 22 faces or are directed to one of the sides of the rib 22. In the rib 22, a corresponding receptacle for the free end of the pressure sensor 18 is formed, in which this preferably fits, so that the free end 28 of the probe 18 is located in the interior of the rib 22 and so the flow inside the suction 4 in Flow direction S affected as little as possible.

In Fig. 6 an alternative arrangement for a sensor is shown, with the sensor itself not shown. In the wall of the suction nozzle 4, a channel 20 or it can be formed a plurality of channels 20 which connect to a sensor located outside of the suction 4. It should be understood that in the embodiment according to Fig. 6 according to the FIGS. 1 to 5 also a rib 22 and / or profile plates 24 are arranged, which are not shown here for the sake of simplicity. In the case of the arrangement of a rib 22, the channel 20 may extend into the rib 22 and preferably be open to one or both side walls of the rib 22. Particularly preferably, two channels 20 are provided, each of which is open to a side wall of the rib 22. Outside the suction nozzle 4, the channels 20 are then in communication with pressure transducer surfaces of one or more sensors.

Based on FIGS. 7 to 9 Three further possible embodiments of an obstruction 16 are explained below.

In the embodiment according to Fig. 7 the obstruction 16 'is arranged similar to the obstruction 16 according to the FIGS. 1 to 6 but does not extend over the entire diameter of the suction nozzle 4, but projects from the inner wall 26 only by a length in the interior of the suction nozzle 4 in which is smaller than the inner diameter of the suction nozzle 4. The obstruction is preferably located in the peripheral area, in which a sensor is located. The remaining embodiment corresponds to the previous description. In particular, it should be understood that also in the embodiment according to Fig. 7 Guiding elements such as rib 22 and / or profile plates 24 are arranged, however, in Fig. 7 not shown. The same applies to the arrangement of the sensor 18 and the channel 20. This is also in the embodiment according to Fig. 7 provided, however, is in Fig. 7 Not shown.

In the embodiment according to Fig. 8 the obstruction is 16 "rod-shaped and extends in the diametrical direction completely through the suction port 4 from one side of the inner wall 26 to the opposite side of the inner wall 25. In cross-section, the obstruction 16" as well as the obstruction 16 and 16 'is preferably triangular. The obstruction 16 "is inserted from the outside through a hole 32 in the suction nozzle 4. The hole 32 extends in the flange 10 from the outer periphery rather into the interior of the suction nozzle 4. Such a hole can be provided with conventional pump units, for example, for a pressure sensor and also to accommodate an obstruction 16 "serve. The hole 32 allows for easy insertion and replacement of the obstruction 16 "from the outside In addition, conventional pumps having such a hole 32 can be provided with such an obstruction 16" later.

In the embodiment according to Fig. 9 the obstruction 16 "'is formed as part of an insert 34. The insert 34 is inserted from the open end into the suction nozzle 4 so that it extends beyond the end of the flange 10 to the outside and into a subsequent pipeline 36 which over The insert 34 is substantially tubular in shape and the obstruction 16 "'extends in a diametric direction from one side to the diametrically opposite side of the insert 34. The obstruction 16 is in cross section '' designed as described above with reference to the obstruction 16, 16 'and 16'. The peripheral wall of the insert 34 bridges the connection area between the flanges 10 and 38 and a gap, if any, between them. In this way, a better flow guidance in the transition between the pipe 36 and the suction nozzle 4 is achieved, since it does not come to turbulence in the area in which the flanges 10 and 38 abut each other. The peripheral wall of the insert 34 may be formed so that it comes smoothly against the inner peripheries of the suction nozzle 4 and the pipe 36 so that it forms no edges or the like there, at which it could come to turbulence of the flow. The edges are preferably aerodynamically optimized, ie rounded, for example. In addition, the peripheral walls of the insert 34 may preferably be formed elastically, so that a sealing contact with the inner circumference of the suction nozzle 4 and the pipe 36 is ensured, especially if there should be a slight offset between the suction 4 and pipe 36. Thus, even with such an offset a smooth flow path between the pipe 36 and suction 4 without larger edges and steps can be created.

With respect to the embodiments according to FIGS. 8 and 9 is to be understood that also in these guide elements such as the rib 22 and / or the profile plates 24, as described above, are provided, however, in FIGS. 8 and 9 have not been shown for the sake of simplicity. The arrangement of the probe is in these embodiments, as with reference to FIGS. 5 and 6 explained, provided. In the embodiment according to Fig. 9 it is also conceivable to arrange the obstruction 16 "in the insert 34 so that the obstruction 16"'is not situated in the suction line 4 but in the adjoining pipeline 36. In this way, an even greater distance between the obstruction 16 'and receiving space 6 and the impeller disposed therein are created.

The guide elements for influencing the flow are, as shown in the figures, conveniently arranged on the side of the inner wall 26 of the suction nozzle 4, which is concavely curved toward the receiving space 6 and has the larger radius of curvature. In this area, a more favorable influence on the flow and damping of undesired turbulence or turbulence can be achieved.

In the examples shown and described, the flow sensor is located in the suction nozzle 4. However, it could be arranged accordingly in the discharge nozzle 12, in which case a rib 22 and / or profile plates 24 are then arranged in the discharge nozzle 12 in a corresponding manner.

LIST OF REFERENCE NUMBERS

2 -

pump housing

4 -

suction

6 -

accommodation space

8th -

connecting flange

10 -

flange

12 -

pressure port

14 -

flange

16, 16 ', 16 ", 16"' -

obstruction

18 -

probe

20 -

channel

22 -

rib

24 -

Profile plate

26 -

inner wall

28 -

free end of the probe

30 -

Pressure receiving surfaces

32 -

hole

34 -

commitment

36 -

pipeline

38 -

counterflange

S -

flow direction

Claims (13)

1. A centrifugal pump assembly with at least one impeller, with a suction union (4) which is situated on the entry side of the impeller, and with a pressure union (12) which is situated on the exit side of the impeller,
   characterised in that
   a vortex flow sensor (16, 18, 20) and at least one guidance element (22, 24) are arranged in a conduit section which is formed by the suction union (4) and/or by the pressure union (12), said at least one guidance element (22, 24) being suitable for influencing the flow prevailing in the conduit section, in a manner such that disturbing turbulences which compromise the measurement result, are kept away from the sensor wherein the at least one guidance element is designed as a rib (22) projecting inwards from the inner wall (26) of the conduit section and/or one guidance element is designed as at least one profile plate (24) which projects inwards from the inner wall (26) of the conduit section and which is orientated transversely to the flow direction (S) of a fluid to be delivered.
2. A centrifugal pump assembly according to claim 1, characterised in that the at least one guidance element (22, 24) is suitable for calming the flow prevailing in the conduit section.
3. A centrifugal pump assembly according to claim 1 or 3, characterised in that the rib (22) extends in the flow direction (S) of a fluid to be delivered, along the inner wall (26) of the conduit section.
4. A centrifugal pump assembly according to one of the preceding claims, characterised in that a measurement probe (18) of the flow sensor is arranged in the rib (22).
5. A centrifugal pump assembly according to claim 4, characterised in that the measurement probe (18) comprises two pressure recording surfaces (30) and is arranged in the rib (22) in a manner such that the two pressure recording surfaces (30) are connected in each case to one side of the rib (22), for pressure impingement.
6. A centrifugal pump assembly according to claim 4 or 5, characterised in that at least one recess for receiving the measurement probe (18) is formed in the rib (22).
7. A centrifugal pump assembly according to one of the preceding claims and one of the claims 4 to 8, characterised in that the profile plate (24) extends transversely to the rib (22) and is designed preferably symmetrical to the middle plane of the rib (22).
8. A centrifugal pump assembly according to claim 7, characterised in that the profile plate (24), proceeding from the inner wall (26), extends further inwards into the conduit section, than the rib (22).
9. A centrifugal pump assembly according to one of the preceding claims, characterised in that the profile plate (24), proceeding from the inner wall (26), is inclined in the flow direction (S) of the fluid to be delivered.
10. A centrifugal pump assembly according to one of the preceding claims, characterised in that the at least one profile plate (24), in the flow direction (S) of the fluid to be delivered, is arranged behind a measurement probe (18, 20) of the sensor.
11. A centrifugal pump assembly according to one of the preceding claims, characterised in that several profile plates (24) are arranged distanced to one another in the flow direction (S).
12. A centrifugal pump assembly according to one of the preceding claims, characterised in that the flow sensor is arranged at the end of the conduit section which is distanced to the impeller, wherein preferably an obstruction (16, 16', 16", 16"') of the flow sensor is situated at the end of the suction union (4) which is distanced to the impeller.
13. A centrifugal pump assembly according to one of the preceding claims, characterised in that an insert (34) is provided at the free end of the suction union (4) in this suction union, said insert (34) extending beyond the free end of the suction union (4) in a manner such that it may enter into an adjacent pipe conduit (36), in order to effect an optimised leading of the flow in the connection region of the pipe conduit (36) and the suction union (4).

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