EP2386767A2 - Helico-axial pump, rotor for same, method for hydrodynamic bearing of a rotor of a helicon-axial pump and a hybrid pump with a rotor for a helico-axial pump - Google Patents

Abstract

The helico-axial pump (1) comprises a partial rotor (21) and a rotor which is arranged in pump housing (6) around a longitudinal axis (A) in a rotating manner. The partial rotor comprises a compression level (K) having a helico-axial propeller (3) and a stator (4) for compression of multiphase mixture (M). A hydrodynamic stabilization bush (70) is arranged with a stabilization surface (700), where a stabilization gap (8) is formed for the stabilization surface. Independent claims are also included for the following: (1) a hybrid pump with a rotor; and (2) a method for hydrodynamic support of a rotor.

Description

The invention relates to a helico-axial pump for conveying multiphase mixtures, a rotor for a helico-axial pump, a hybrid pump with a helico-axial pump and a method for mounting a rotor in a helico-axial pump according to the preamble of the independent claims 1 , 10, 13 and 14.

In the promotion of multiphase mixtures, such as crude oil, which in addition to petroleum also contains natural gas and often also water and solid fractions such as sand, there is the problem that with increasing proportion of gas in the multiphase mixture, the efficiency of the pumping devices used decreases. For example, at low gas densities, the use of pumping devices with radial impellers is already no longer possible or no longer economical even at a volumetric gas / liquid ratio of greater than 0.04 to 0.06. In conventional conveyor systems, therefore, the gaseous phase of the multiphase mixtures is first separated from the liquid at a higher gas content and the two phases are then conveyed separately under different delivery conditions. Such a separation of the liquid and gaseous phase of the multiphase mixtures is dependent on the specific conditions of use at the site of promotion and not always possible or economical. Special pump or compression devices have therefore been developed in order to reduce the volumetric gas / liquid ratio of the multiphase mixtures to be delivered to such an extent that subsequently a conventional pumping device can be used for further delivery, for example a positive displacement pump, a rotary pump or a jet pump.

Such pumping or compression device for multi-phase mixtures with increased gas content, for example, already from the GB-A-1 561 454 , of the EP 0 486 877 or the US 5,961,282 known.

For example, the hybrid pump is according to US 5,961,282 a system for compressing a multiphase mixture, which may comprise, in addition to a liquid phase in particular a significant proportion of gas. The pump in this case comprises a multi-stage axial flow pump for reducing the relative gas content, ie the axial flow pump serves to increase the density of the multiphase mixture, so that it can finally be pumped from a lower level to a higher level by another conventional centrifugal pump, for example from the bottom of the Marine on an oil platform, a ship or a land-based facility.

As already mentioned, the helico-axial pump acting as a compressor comprises a rotor having a plurality of compression stages, in practice for example up to sixteen or more stages, such that the multiphase mixture progressively increases from a relatively low density with a high relative volume fraction of gas is compressible to a highly compressed multiphase mixture having such a high density that the highly compressed mixture can be further conveyed by a usual feed pump.

A known compression stage K 'of a rotor 2' of a helico-axial pump 1 'is shown schematically in FIG Fig. 1a and Fig. 1b shown for clarity in Fig. 1b a section II of a section according to Fig. 1a is shown parallel to the longitudinal axis A '.

Each compression stage K 'comprises a rotating impeller 3' with screw 31 ', the rotating impeller 3' resembling a short Archimedean screw, and a stator 4 'adjoining it, which consists of a plurality of static, ie non-rotating blades 41' , Impeller 3 'and stator 4' are in such a way with respect to a common pump shaft 5 ', mounted that the impeller 3' is set in the operating state of the pump shaft 5 'in rotation, while the stator 4' from the rotational movement of the pump shaft 5 ' is decoupled and therefore not rotated with respect to the impeller 3 '. The pump shaft 5 'extends along a longitudinal axis A'. The plurality of compression stages K 'are arranged in series in a substantially tubular pump housing 6' in series.

The rotating screw 31 'conveys the multi-phase mixture M' in the direction of the arrow, for example, from a in Fig. 1a and Fig. 1b not shown preceding compression stage K 'in the stator 4', whereby in the stator 4 'kinetic energy is converted into pressure energy, which leads to the compression of the multiphase mixture M'.

In order to obtain a sufficiently high compression of the multiphase mixture M ', in practice, as already mentioned, a larger number of, for example, up to sixteen or more compression stages K', each consisting of an impeller 3 'and a stator 4' in Series are provided, which inevitably leads to a considerable length of the helico-axial pump 1 '.

The decisive disadvantage of such long rotors 2 'formed from a plurality of compression stages K' is that they are very difficult to control in terms of vibration. These long rotors 2 'form in the interior of the tubular pump housing 6' namely a vibratory system, which in particular can form different transverse vibration modes that can be so intense that the Pump can not be operated at a given number of revolutions or in a certain revolution field. In addition, the efficiency of the pump 1 'can be reduced and in the worst case, even damage to the pump 1' are to be feared when the rotor 2 ', for example, begins to vibrate so strong and uncontrolled that parts of the rotor 2', such as the wheels 3 'come into contact with the pump housing, for example, by the oscillatory motion. The type and intensity of the vibrations of the rotor 2 'depends not only on the specific geometry but also on the operating state of the pump 1', the multiphase mixture M 'to be pumped, the rotational speed of the pump 1' and other known parameters, some of which are not exactly known so that it is hardly possible to get to grips with the problems with the harmful vibrations of the rotor 2 'solely by adapting the geometrical relationships of known pumps 1' or by using new materials.

There is a clear desire for pumps with an ever higher number of compression stages, so that multi-phase mixtures with ever higher gas content always better, that can be compressed to ever higher pressures, so that the thus compressed multiphase more reliable and still greater pressure or Height differences can be pumped further.

The object of the invention is therefore to propose a helico-axial pump for promoting multi-phase mixtures, in which the harmful vibrations of the rotor are largely avoided and the vibrations of the rotor are reduced or damped to a predeterminable degree, so that on the one hand an improved run of Rotor can be achieved in the operating state and the pump on the other hand can be operated at speeds or in order to a rotating field in which the from the state The art known Helico-axial pumps can not be operated due to the above-described harmful vibrations of the rotor. In addition, the new pump should be able to be equipped alternatively or simultaneously with more compression levels than is possible with the previously known in the prior art pumps, in which limits the length of the pump and thus the maximum number of compression stages by the vibrations of the rotor in the operating state is.

The objects of the invention which solve this object are characterized by the features of the independent claims of the respective category.

The dependent claims relate to particularly advantageous embodiments of the invention.

The invention thus relates to a helico-axial pump for conveying a multiphase mixture, which helico-axial pump comprises a rotor rotatably mounted in a pump housing about a longitudinal axis with a first part rotor and a second part rotor, wherein the first part rotor and the second part rotor for compression of Multiphase mixture comprises a compression stage with a helico-axial impeller and a stator. According to the invention, a hydrodynamic stabilizing bushing with a stabilizing surface is provided between the first part rotor and the second part rotor and configured such that a stabilizing gap is formed in front of the stabilizing surface, so that a hydrodynamic stabilizing layer of a stabilizing medium can be formed in the stabilizing gap in the operating state.

It is therefore essential for the invention that a hydrodynamic stabilizing bush is provided with a stabilizing surface in the pump housing, so that a stabilizing gap is formed in front of the stabilizing surface, in which stabilizing gap a hydrodynamic stabilizing layer is formed in the operating state of the pump.

The present invention thus decisively improves the rotor dynamics because the damping and stiffness of the oscillatory rotor system is decisively increased by the stabilization layer.

The harmful vibrations of the rotor are largely avoided by the formation of the stabilizing layer in the stabilizing gap in front of the stabilizing surface of the stabilizing bushing and are reduced or damped at least to a predeterminable tolerable measure, so that the pump can be operated even at a speed or in a certain revolution field where this is no longer possible without the use of the stabilizing layer according to the invention. In addition, possibly even a higher efficiency of the pump and a smoother improved running of the rotor can be achieved in the operating state. This ultimately leads, of course, not only to save energy for the operation of the pump, but also the maintenance intervals can be extended, whereby the associated costs can be drastically reduced and at the same time the life of the pump is significantly increased.

Another particular advantage is that the invention makes it possible for the first time to design pumps with a much higher number of compression stages than was previously possible. So far, the possible number of compression stages alone was limited by the massively increasing with increasing number of compression stages oscillations of the rotor. By means of the invention, the rotor can be reliably stabilized practically on any length.

In the case of a helico-axial pump according to the invention, the stabilizing layer in the stabilizing gap in front of the stabilizing surface of the hydrodynamic stabilizing bushing is quasi-automatic, so that in a simple embodiment, which is of particular importance in practice, except for a suitable adjustment of the size or form the stabilizing gap or the stabilizing bushing and / or their stabilizing surface no further structural measures must be made.

If the geometry of the stabilizing gap in a helico-axial pump according to the invention is set according to the requirements, a pressure difference between the multiphase mixture, which is located in the first part rotor and that which is in the second part rotor, develops in the operating state above the stabilizing gap such that a predeterminable flow of multiphase mixture from the second sub-rotor on the stabilizing gap back to the first sub rotor automatically adjusts, which automatically forms a stabilizing layer for stabilizing or damping the harmful vibrations of the rotor.

In this case, the degree, ie the strength of the damping depending on technical requirements or specifications in a novel helico-axial pump in a simple manner adaptable. This can be done, for example, by a suitable choice of geometry, for example the geometric shape or width of the stabilizing gap.

An inventive helico-axial pump is particularly preferably designed in the form of a so-called back-to-back arrangement. Under a back-to-back arrangement, the expert understands an arrangement of two pump rotors in series, which forms such a pump with two pressure levels. The medium to be pumped is fed via a suction opening of the pump of the first pressure stage, wherein the medium passes through the first pressure stage in a first axial direction, wherein the pressure of the medium to be pumped is increased to a first intermediate pressure. From the first pressure stage, the medium is then supplied via a channel system of the second pressure stage such that the medium passes through the second pressure stage in a second axial direction, which is opposite to the first axial direction of the first pressure stage. In the second pressure level is the Medium then brought to the desired final pressure and removed via a pressure port for further use of the pump.

Essential for the back-to-back arrangement of the pumps known from the prior art, which are not all helico-axial pumps, is that the flow direction of the medium in the first pressure stage is opposite to the direction of flow in the second pressure stage. In the known pumps, the back-to-back arrangement serves exclusively to compensate for the enormous thrust forces acting in the axial direction on the bearings of the pump shaft, at least partially, and thus to relieve the bearings. The enormous axial thrust forces are due to the fact that in these known from the prior art pumps very high pressures are generated with very large components in the axial direction. Vibration of the pump rotor play a very minor role here, because the rotors themselves usually have no large axial extent and / or consist of only one compression stage and / or between the first pressure stage and the second pressure stage an additional mechanical bearing, for example Ball bearing is provided, which additionally stores the pump rotor in the middle mechanically.

Since in helico-axial pumps, the axial pressure components are rather small compared to other conventional pumps, the thrust forces which act in the axial direction on the bearings of the helico-axial pump play no decisive role here. Therefore, a back-to-back arrangement for helico-axial pump has never been considered, because in helico-axial pumps, the known advantage of the back-to-back arrangement can not actually be exploited.

The essential realization of the invention is therefore that the back-to-back arrangement can be used successfully in the case of helico-axial pumps, if between the first part rotor and the second part rotor a stabilizing bush according to the invention is provided, so that due to the pressure gradient between the first part rotor and the second part rotor in the stabilizing gap can form a stabilizing layer of the stabilizing medium, which is particularly preferably the multiphase mixture itself to be pumped, so that damped by the stabilizing layer, the vibrations of the rotor to a specifiable, innocuous measure.

In a particularly preferred embodiment, the first part rotor and the second part rotor are thus provided in a back-to-back arrangement in the pump housing such that the multiphase mixture can be fed via a suction opening to a first input compression stage of the first part rotor and via a first output compression stage from the first part rotor in a first cross-channel is discharged again. From the first cross-channel, the multiphase mixture can then be fed to a second input compression stage of the second sub-rotor and can be discharged again via a second output compression stage from the second sub-rotor via a second cross-channel and a pressure opening from the helico-axial pump. In this case, the first output compression stage and the second output compression stage are each arranged adjacent to the stabilization bushing.

As will be explained in more detail later in the drawings, the stabilizing bush is configured and arranged on the rotor such that the stabilizing gap is formed between the stabilizing bushing and the pump housing. At the same time or alternatively, however, the stabilizing bushing can be designed and arranged on the rotor such that the stabilizing gap is formed between the stabilizing bushing and the rotor.

In an embodiment which is likewise important for practice, a hydrodynamic stabilizing element having a stabilizing surface is additionally provided and configured in such a way that in front of the stabilizing surface of the stabilizing surface Stabilizing gap is formed so that in operation a hydrodynamic stabilizing layer of the stabilizing medium in the stabilizing gap can be formed, wherein the additional stabilizing element is preferably a cover ring which surrounds the helico-axial impeller in the circumferential direction, so that the stabilizing gap between the cover ring and the pump housing is formed , In this case, such a cover ring may be provided on all helico-axial impellers of a rotor, or only on selected individual impellers, whereby the production of the rotor, of course, becomes much less expensive and cost-effective.

In another important embodiment of the present invention, the additional stabilizing element is provided in the form of a stabilizing sleeve between two adjacent compression stages on the rotor. Whereby a stabilizing sleeve can be provided between all adjacent compression stages of a rotor, whereby a particularly good damping of the vibrations of the rotor can be achieved, especially at very high loads, or only between individual selected pairs of compression stages, whereby the production of the rotor, of course, significantly less consuming and cost-effective.

The stabilizing sleeve can be designed and arranged on the rotor such that the stabilizing gap is formed between the stabilizing sleeve and the pump housing, and / or the stabilizing sleeve can also be designed and arranged on the rotor such that the stabilizing gap is formed between the stabilizing sleeve and the rotor , In particular, both variants can be realized on one and the same rotor, whereby in certain cases a particularly high smoothness and particularly good damping of the rotor vibrations can be achieved.

If the geometry of the stabilizing gap of the additional hydrodynamic stabilizing element in a helico-axial pump according to the invention is set according to the requirements, a pressure difference between the multiphase mixture which is at a higher pressure level and that which is at a lower pressure level is formed in the operating state above the stabilizing gap is such that a predeterminable flow of multiphase mixture automatically adjusts itself via the stabilizing gap from the higher pressure level back to the lower pressure level, whereby a stabilizing layer for additional stabilization or damping of the damaging vibrations of the rotor automatically forms.

However, additional measures can be taken to form the hydrodynamic stabilizing layer, in particular if the oscillations occurring are very strong or if the damping depends on certain operating parameters, such as the load under which the pump is operated, or depending on the RPM should be set.

Thus, it is particularly preferable to use an already more highly compressed multiphase mixture taken from a compression stage in which the multiphase mixture is already more compressed than it is compressed in the stage in which it is used for the formation of the stabilization layer. Alternatively or at the same time, however, a multiphase mixture compressed in the same compression stage may be used to form the hydrodynamic stabilization layer, which is still the case for example with reference to FIG Fig. 4 will be explained in detail. For this purpose, for example, be provided in or on the pump housing special channels or lines that connect a supply port for supplying the multiphase mixture in the stabilizing gap with the pressure output of a predetermined compression stage.

It is understood that the stabilizing medium for forming the stabilizing layer in special cases can also be provided by other external sources, for example by a pressure accumulator or by a pump, the medium for forming the stabilizing layer under a predetermined, in particular a controllable and / or controllable pressure for introduction into the stabilizing gap provides. Also, the stabilizing medium need not necessarily be the multiphase mixture to be pumped to form the stabilizing layer, but may also be another stabilizing medium, e.g. an oil, water or other liquid or gaseous stabilizing medium or fluid.

Furthermore, it is possible, for example, for the pressure of the multiphase mixture introduced into the stabilizing gap to be controlled and / or regulated by means of a valve known per se. It is also possible, for example, to supply the multiphase mixture simultaneously or alternatively from different compression stages to the stabilizing gap, whereby likewise the pressure in the stabilizing gap and thus the degree of damping or stiffness of the oscillating rotor can be set in a very simple manner and very flexibly to different requirements and changing operating conditions is customizable.

As will be explained later by way of example with reference to the drawings of particularly preferred embodiments, the stabilizing gap on the additional stabilizing element and of course on the stabilizing sleeve, for example between the stabilizing surface and the pump housing are formed and / or between the stabilizing surface and the rotor can be provided ,

In this case, in a particularly preferred embodiment of the present invention, a feed channel may be provided which is designed and arranged such that a multiphase mixture which is under a prescribable pressure and hence a prescribable amount of multiphase mixture through the feed channel to the stabilizing gap for forming the hydrodynamic stabilizing layer in the stabilizing gap can be fed, wherein the feed channel is preferably provided in a split ring.

Thus, the stabilizing element may for example be designed as a stator with a feed channel, wherein the feed channel is formed and arranged on the stator, that for the formation of the hydrodynamic stabilizing layer in the stabilizing gap under a predeterminable pressure a predetermined amount of a stabilizing medium, in particular to multi-phase mixture through the feed channel Stabilizing gap can be fed.

In a further embodiment variant, the feed channel can be arranged and formed on the pump housing in such a way that a predeterminable amount of stabilizing medium, in particular a multiphase mixture, can be fed to the stabilizing gap through the feed channel to form the hydrodynamic stabilizing layer in the stabilizing gap.

Or else a feed channel is arranged and formed on the rotor such that a predeterminable amount of stabilizing medium, in particular a multiphase mixture, can be supplied to the stabilizing gap through the feed channel for forming the hydrodynamic stabilizing layer in the stabilizing gap.

As already mentioned, in the case of a helico-axial pump according to the invention, the stabilization medium, in particular the multiphase mixture, can be particularly preferably fed to the feed channel from a compression stage be fed, at which a higher pressure level prevails, than at the compression stages, where it is supplied as a stabilizing medium. Alternatively or simultaneously, however, a multiphase mixture compressed in the same compression stage can also be used to form the hydrodynamic stabilization layer.

The invention further relates to a rotor for arrangement in a pump housing of a helico-axial pump for conveying a multiphase mixture. In this case, the rotor rotatably mounted about a longitudinal axis comprises a first part rotor and a second part rotor, and the first part rotor and the second part rotor for compression of the multiphase mixture comprises a compression stage with a helico-axial impeller and a stator. According to the invention, a hydrodynamic stabilizing bushing with a stabilizing surface is provided between the first part rotor and the second part rotor and configured so that a stabilizing gap can be formed in front of the stabilizing surface, so that a hydrodynamic stabilizing layer can be formed from a stabilizing medium in the stabilizing gap in the operating state.

In a specific embodiment, an additional hydrodynamic stabilizing element may be provided with a stabilizing surface in the form of a cover ring, which surrounds the helico-axial impeller in the circumferential direction, so that the stabilizing gap between the cover ring and a pump housing of the helico-axial pump can be formed. Alternatively or simultaneously, however, the hydrodynamic stabilizing element can also be a stabilizing sleeve, which is provided, for example, between two adjacent compression stages, so that the stabilizing gap is formed between the stabilizing sleeve and the pump housing.

In particular, a feed channel may be provided which is designed and arranged such that a predeterminable amount of stabilizing medium, in particular a multiphase mixture, can be fed to the stabilizing gap through the feed channel to form the hydrodynamic stabilizing layer in the stabilizing gap.

The invention further relates to a hybrid pump with a rotor according to the invention for a helico-axial pump he present invention for the promotion of a multi-phase mixture.

Finally, the invention also relates to a method for hydrodynamic mounting of a rotor according to the invention in a helico-axial pump or in a hybrid pump according to the present invention, wherein in a pump housing, the rotor is rotatably supported about a longitudinal axis, and the rotor for compression of the multiphase mixture, a compression stage comprising a helico-axial impeller and a stator. According to the invention, a hydrodynamic stabilizing bushing with a stabilizing surface is provided and configured in the pump housing in such a way that a stabilizing gap is formed in front of the stabilizing surface, so that in operation a hydrodynamic stabilizing layer is formed from a stabilizing medium in the stabilizing gap for the hydrodynamic bearing of the rotor.

Fig. 1 a

eine Kompressionsstufe einer aus dem Stand der Technik bekannten helico-axialen Pumpe;

Fig. 1 b

eine Pumpe gemäss Fig. 1a teilweise im Schnitt;

Fig. 2

ein Ausführungsbeispiel einer erfindungsgemässen helicoaxialen Pumpe in Back-to-Back Anordnung;

Fig. 3

eine Detaildarstellung der Back-to-Back Anordnung gemäss Fig. 2 im Betriebszustand;

Fig. 4

ein Ausführungsbeispiel mit einem zusätzlichen hydrodynamischen Stabilisierungselement in Form eines Deckrings;

Fig. 5a

ein Ausführungsbeispiel der Fig. 4 mit zusätzlicher Einspritzung am Deckring;

Fig. 5b

das Ausführungsbeispiel der Fig. 5a mit Einspritzung unter höherem Druck;

Fig. 6a

ein drittes Ausführungsbeispiel gemäss Fig. 4 mit Einspritzung am Stator;

Fig. 6b

ein anderes Ausführungsbeispiel gemäss Fig. 6a ohne Deckring am helico-axialen Laufrad;

Fig. 6c

ein weiteres Ausführungsbeispiel gemäss Fig. 6b mit Einspritzung aus dem Rotor;

Fig. 7a

ein viertes Ausführungsbeispiel gemäss Fig. 4 mit Stabilisierungshülse und Einspritzung;

Fig. 7b

ein anderes Ausführungsbeispiel gemäss Fig. 7a ohne Deckring am helico-axialen Laufrad.

In the following the invention will be explained in more detail with reference to the drawing. In a schematic representation:

Fig. 1 a

a compression stage of a known from the prior art helico-axial pump;

Fig. 1 b

a pump according to Fig. 1a partly in section;

Fig. 2

An embodiment of an inventive helicoaxial pump in back-to-back arrangement;

Fig. 3

a detailed representation of the back-to-back arrangement according to Fig. 2 in the operating condition;

Fig. 4

an embodiment with an additional hydrodynamic stabilizing element in the form of a cover ring;

Fig. 5a

an embodiment of the Fig. 4 with additional injection on the cover ring;

Fig. 5b

the embodiment of Fig. 5a with injection under higher pressure;

Fig. 6a

a third embodiment according to Fig. 4 with injection at the stator;

Fig. 6b

another embodiment according to Fig. 6a without cover ring on helico-axial impeller;

Fig. 6c

a further embodiment according to Fig. 6b with injection from the rotor;

Fig. 7a

a fourth embodiment according to Fig. 4 with stabilization sleeve and injection;

Fig. 7b

another embodiment according to Fig. 7a without cover ring on the helico-axial impeller.

The basis of the Fig. 1a and Fig. 1b The prior art described above has already been described in detail, so that here is a further discussion of Fig. 1a and Fig. 1b unnecessary.

It should be noted that to better distinguish the invention from the prior art in the drawings, those reference numerals relating to features or embodiments of the prior art are provided with a single quote, while reference numerals to features according to the invention Embodiments do not wear an apostrophe.

Based on Fig. 2 a first embodiment of an inventive helico-axial pump in back-to-back arrangement will be explained schematically.

The helico-axial pump 1 for conveying a multi-phase mixture M according to Fig. 2 comprises a rotatably mounted in a pump housing 6 about a longitudinal axis A rotor 2 with a first part rotor 21 and a second part rotor 22. The rotor 2 is driven by a drive 1000, which is for example an electric motor 1000. The first sub-rotor 21 and the second sub-rotor 22 for compression of the multiphase M each comprise a plurality of compression stages K with a helico-axial impeller 3 and a stator 4. According to the present invention, a hydrodynamic stabilizing bushing 70 having a stabilizing surface 700 between the first sub rotor 21 and the second part rotor 22, a stabilizing gap 8 is formed in front of the stabilizing surface 700, so that a hydrodynamic stabilizing layer S can be formed from a stabilizing medium in the stabilizing gap 8 in the operating state of the pump 1.

The Fig. 3 shows a detailed representation of the back-to-back arrangement according to Fig. 2 in the operating state of the helico-axial pump 1. As can be clearly seen, the first part rotor 21 and the second part rotor 22 are arranged in a back-to-back arrangement on a common pump shaft 5 in the pump housing 6. The first part rotor 21 and the second part rotor 22 are separated from each other by the stabilizing bushing 70. The multiphase mixture M is fed via a suction opening 101, a first annular space R1 and a second annular space R2 of a first input compression stage K1 E of the first part rotor 21 and a first output compression stage K1 A from the first part rotor 21 in a first cross channel KR1 from the first part rotor 21 again dissipated. Coming from the first cross channel KR1, the multiphase mixture M then becomes a second annular space R3 of a second

Input compression stage K2E of the second sub-rotor 22 is supplied and discharged via a second output compression stage K2A from the second sub-rotor 22 via a second cross channel KR2, a fourth annular space R4 and a pressure port 102 from the helico-axial pump for further use again. In order to obtain a maximum pressure difference .DELTA.P over the stabilizing bushing 70 and thus to ensure the formation of an optimal stabilizing layer S in the stabilizing gap 8, the first output compression stage K1A and the second output compression stage K2A are each arranged adjacent to the stabilizing bushing 70.

In the example of Fig. 3 the stabilizing bushing 70 is designed and arranged on the rotor 2 such that the stabilizing gap 8 is formed between the stabilizing bushing 70 and the pump housing 6. As later still completely analogous on the basis of Fig. 6a to 7b be explained in more detail, the stabilizing sleeve 70 may alternatively or even simultaneously configured and arranged on the rotor 2, that the Stabilizing gap 8 between the stabilizing sleeve 70 and the rotor 2 is formed.

Based on Fig. 4a , which shows a section with two adjacent compression stages K of a rotor 2 according to the invention in a schematic representation, an embodiment with an additional hydrodynamic stabilizing element in the form of a cover ring will be briefly discussed.

The rotor 2 of the helico-axial pump 1 is rotatably mounted in the pump housing 6 about a longitudinal axis A. The rotor 2 comprises the compression stages K with a helico-axial impeller 3 and a stator 4 for compressing the multiphase mixture M in a manner known per se.

According to the present invention, in addition to the in Fig. 4a stabilizing book 70 not shown, a hydrodynamic stabilizing element 7, 71 provided with a stabilizing surface 700 in the pump housing 6 and configured such that a stabilizing gap 8 is formed in front of the stabilizing surface 700, so that in the operating state here a hydrodynamic stabilizing layer S from the multiphase M in the Stabilizing gap 8 is formed.

In the present example the Fig. 4 is the additional stabilizing element 7, a cover ring 71 which surrounds the helico-axial impeller 3 in the circumferential direction, so that the stabilizing gap 8 between the cover ring 71 and the pump housing 6 can be formed.

For reasons of clarity, only one or two compression stages K are shown in each of the following figures. Although it is possible in principle that a helico-axial pump 1 according to the invention comprises only a single compression stage K, a helico-axial pump 1 according to the invention, ie the first part rotor 21 and the second part rotor 22 in practice a plurality of compression stages K. include, for example up to sixteen compression stages K or even significantly more compression stages K, which are preferably arranged one behind the other in series along the longitudinal axis A, so that sufficient total compression of the multiphase mixture M can be produced in a manner known per se and then the multiphase mixture M thus compressed, for example can be promoted with a downstream pressure pump to a higher level and / or over long distances for further processing.

In the embodiment according to Fig. 4 we formed the stabilizing layer S from the stabilizing medium M in the stabilizing gap 8, characterized in that the multiphase mixture M, as shown symbolically by the double arrow M, according to presentation from the left of the representation according left compression stage K is fed and compressed by this in a conventional manner, which of course with a corresponding pressure increase is accompanied, which also establishes itself as a pressure difference .DELTA.P on the helico-axial impeller 3 compression stage K.

Due to the pressure difference .DELTA.P, as indicated by the small curved arrows M, multiphase mixture M is pressed into the stabilizing gap 8 from the illustration to the right on the right, whereby the hydrodynamic stabilizing layer S between the stabilizing surface 700 of the cover ring 7 and the pump housing 6 is formed automatically the wings of the rotor 2 and the sub-rotors 21, 22 are damped and the run of the rotor 2 is stabilized.

It is understood that in a rotor 2 of the present invention, the cover ring 71 may be formed either on all helico-axial wheels 3 of the rotor, or only on certain selected helico-axial wheels 3. Otherwise, depending on the application or ever according to the special requirements of the cover ring 71 completely cover a helico-axial impeller 3 or a certain predetermined range of the circumference of the helico-axial impeller third

Based on Fig. 5a is a second embodiment according to Fig. 4 shown schematically, which differs from that of the Fig. 4 differs in that an injection of the stabilizing medium M is provided on the cover ring 71 of the helico-axial impeller 3. Here additionally stabilizing medium M is introduced through the feed channel 400, 402 in the stabilizing gap 8 to form the stabilizing layer S. It goes without saying that here, too, as in the discussion of the Fig. 4 described, will set a pressure difference .DELTA.P over the helico-axial impeller 3 in the operating state, whereby the stabilizing layer S is already partially formed. By using the injection of stabilizing medium M under increased pressure through the feed channel 400, 402, however, an even better stabilizing layer S can be built up in the stabilizing gap 8, so that even very long rotors 2 or very heavily loaded rotor 2 are still sufficiently damped and safely stored can be.

In principle, an additional injection of stabilizing medium can also take place in the stabilizing gap S of the stabilizing bushing 70.

The embodiment of Fig. 5b differs from that of the Fig. 5a only in that the injection of the stabilizing medium M on the cover ring 71 of the helico-axial impeller 3 is carried out under a significantly higher pressure than in the example of Fig. 5a , This can be clearly seen from the fact that the stabilizing medium M at Fig. 5b according to the representation both to the left, ie in the direction of a compression stage K with a lower pressure level as well as to the right, ie also in the direction of a compression stage with a higher pressure level from the stabilizing gap 8 is pressed out.

In contrast, in the example of Fig. 5a the pressure with which the stabilizing medium M is introduced through the feed channel 400, 402 into the stabilizing gap 8 to form the stabilizing layer S. will be much smaller than in Fig. 3a , This is clear from the fact that the stabilizing medium M at Fig. 3 can occur from the right, ie from a compression stage with a higher pressure level in the stabilizing gap 8 according to the representation.

The stabilizing medium M can be provided by an external pressure accumulator or an external pump as already described; however, is preferably provided by another compression stage K having a higher pressure level.

Based on the schematic Fig. 6a is a third embodiment according to Fig. 4 shown with an injection of the stabilizing medium on the stator 4. Here, a feed channel 400, 401 in the form of a bore is provided on the stator 4, for example on a blade of the stator 4, or else a separate feed channel 400, 401 may be provided which, as in FIG Fig. 6a represented by the pump housing 6 extends to the stabilizing gap 8, so that between the rotor 2 and the stabilizing surface 700 of the stator 4 designed as a stabilizing element 73, a stabilizing layer S according to the invention from stabilizing medium M, which in the specific example of Fig. 6a Multi-phase mixture M from another compression stage is, can be formed.

In Fig. 6b is another embodiment according to Fig. 6a represented, which differs from that of Fig. 6a only differs in that the helico-axial impeller 3 no cover ring 71 is provided. Such a simplified construction can be used successfully, for example, whenever the stabilization of the rotor 2 by the stabilization layer S on the stator 4 is already sufficient.

Fig. 6c shows a further variant of the embodiment according to Fig. 6b , Here, the supply of the stabilizing medium M does not take place via a feed channel 400, 401 through the pump housing 6, but the injection of the stabilizing medium M takes place through a feed channel 400, 403, which is formed in the rotor 2. For this purpose, the rotor 2 may, for example, have a hollow rotor shaft or suitable channels or lines may be formed in the rotor shaft through which the stabilizing medium M, for example multi-phase mixture M, can be supplied from a compression stage K with a higher pressure level.

The Fig. 7a on the other hand shows a fourth, different embodiment according to Fig. 4 in which between two adjacent compression stages K, an additional stabilizing sleeve 72 is provided, wherein injection of the stabilizing medium M in the stabilizing gap 8 by a guided through the pump housing 6 feed channel 400, 402 takes place. Such an arrangement is particularly suitable when a very high stability or damping of the rotor 2 has to be achieved. In this case, the injection into the stabilizing gap 8 can in principle also be analogous to Fig. 6c take place through the rotor shaft of the rotor 2. Moreover, it is as schematic in Fig. 7b shown of course also possible that can be dispensed with all or different helico-axial wheels 3 on the bezel.

It is of course also possible in special cases that alternatively or in addition to the stabilizing sleeve 72 between each two adjacent compression stages K, a stabilizing sleeve 72 may be provided within a compression stage K between the helico-axial impeller 3 and the stator 4. The skilled person immediately understands that not at each or not between each pair of compression stages K, a stabilizing sleeve 72 must be provided.

It is understood that all embodiments of the invention described above are to be understood as exemplary only or by way of example, and the invention particularly, but not exclusively, includes all suitable combinations of the described embodiments.

Claims (15)

Helico-axial pump for conveying a multiphase mixture (M), which helico-axial pump has a rotor (2) rotatably mounted in a pump housing (6) about a longitudinal axis (A) with a first part rotor (21) and a second part rotor (22) comprising, wherein the first part rotor (21) and the second part rotor (22) for compression of the multiphase mixture (M) a compression stage (K, K1 E, K1 A, K2E, K2A) with a helico-axial impeller (3) and a stator (4), characterized in that a hydrodynamic stabilizing bush (70) with a stabilizing surface (700) between the first part rotor (21) and the second part rotor (22) is provided and configured such that a stabilizing gap is provided in front of the stabilizing surface (700) (8) is formed, so that in the operating state, a hydrodynamic stabilizing layer (S) from a stabilizing medium in the stabilizing gap (8) can be formed. Helico-axial pump according to claim 1, wherein the first part rotor (21) and the second part rotor (22) are provided in a back-to-back arrangement in the pump housing (6) such that the multi-phase mixture (M) via a suction opening (101 ) of a first input compression stage (K1 E) of the first part rotor (21) can be fed and via a first output compression stage (K1 A) from the first part rotor (21) in a first cross channel (KR1) is again dissipated, and the multi-phase mixture (M) the first cross-channel (KR1) of a second input compression stage (K2E) of the second sub-rotor (22) can be fed and via a second output compression stage (K2A) from the second sub-rotor (22) via a second cross-channel (KR2) and a pressure port (102) from the Helico-axial pump is again dischargeable, wherein the first output compression stage (K1 A) and the second output compression stage (K2A) are each arranged adjacent to the stabilizing bushing (70). Helico-axial pump according to one of claims 1 or 2, wherein the stabilizing bush (70) is designed and arranged on the rotor (2) such that the stabilizing gap (8) is formed between the stabilizing bush (70) and the pump housing (6). and / or wherein the stabilizing bushing (70) is designed and arranged on the rotor (2) such that the stabilizing gap (8) is formed between the stabilizing bushing (70) and the rotor (2). Helico-axial pump according to one of the preceding claims, wherein a hydrodynamic stabilizing element (7, 71, 72, 73) with a stabilizing surface (700) is provided and configured in such a way that the stabilizing gap (8) is formed in front of the stabilizing surface (700). so that in the operating state, a hydrodynamic stabilizing layer (S) from the stabilizing medium in the stabilizing gap (8) can be formed. Helico-axial pump according to claim 4, wherein the hydrodynamic stabilizing element (7, 71, 72, 73) is a cover ring (71) which encloses the helico-axial impeller (3) in the circumferential direction, so that the stabilizing gap (8) between the hydrodynamic stabilizing element (7, 71, 72, 73) is a stabilizing sleeve (72), so that the stabilizing gap (8) between the stabilizing sleeve (72) and the pump housing (6) is formed. Helico-axial pump according to one of the preceding claims, wherein a feed channel (400, 401, 402, 403) is provided, which is designed and arranged such that for forming the hydrodynamic stabilizing layer (S) in the stabilizing gap (8) to a predeterminable amount of Stabilization medium (M), in particular multi-phase mixture (M) through the feed channel (400, 401, 402, 403) the stabilizing gap (8) can be fed, wherein the feed channel (400, 401, 402, 403) is preferably provided in a split ring (9). Helico-axial pump according to one of claims 4 to 6, wherein the stabilizing element (7, 71, 72, 73) of the stator (4) with a feed channel (401) which is formed and arranged on the stator (4) that for the formation of the hydrodynamic stabilization layer (S) in the stabilizing gap (8), a predeterminable amount of stabilizing medium (M) can be supplied to the stabilizing gap (8) through the feed channel (401). Helico-axial pump according to one of the preceding claims, wherein on the pump housing, a feed channel (402) is arranged and formed such that for forming the hydrodynamic stabilizing layer (S) in the stabilizing gap (8) a predetermined amount of stabilizing medium (M) through the feed channel ( 402) can be fed to the stabilizing gap (8). Helico-axial pump according to one of the preceding claims, wherein on the rotor (2) a feed channel (403) is arranged and formed such that for forming the hydrodynamic stabilizing layer (S) in the stabilizing gap (8) a predetermined amount of stabilizing medium (M) the feed channel (403) the stabilizing gap (8) can be fed. Helico-axial pump according to one of claims 6 to 9, wherein the feed channel (400, 401, 402, 403), the stabilizing medium (M) from a compression stage (K) is supplied, at which there is a higher pressure level. A rotor for mounting in a pump housing (6) of a helico-axial pump (1) according to any one of claims 1 to 10 for conveying a multiphase mixture (M), which is rotatable about a longitudinal axis (A) storable rotor (2) comprises a first part rotor (21) and a second part rotor (22), and the first part rotor (21) and the second part rotor (22) for compression of the multiphase mixture (M) a compression stage (K, K1 E, K1A , K2E, K2A) with a helico-axial impeller (3) and a stator (4), characterized in that a hydrodynamic stabilizing bushing (70) with a stabilizing surface (700) between the first part rotor (21) and the second part rotor (22) is provided and configured such that a stabilizing gap (8) can be formed in front of the stabilizing surface (700), so that a hydrodynamic stabilizing layer (S) of a stabilizing medium in the stabilizing gap (8) can be formed in the operating state. Rotor according to claim 11, wherein a hydrodynamic stabilizing element (7, 71, 72, 73) is provided with a stabilizing surface (700) in the form of a cover ring (71), which surrounds the helico-axial impeller (3) in the circumferential direction, so that the Stabilization gap (8) between the cover ring (71) and a pump housing (6) of the helico-axial pump (1) can be formed, and / or wherein the hydrodynamic stabilizing element (7, 71, 72, 73) is a stabilizing sleeve (72), such that the stabilizing gap (8) is formed between the stabilizing sleeve (72) and the pump housing (6). Rotor according to one of claims 11 or 12, wherein a feed channel (400, 401, 402, 403) is provided, which is designed and arranged such that for forming the hydrodynamic stabilization layer (S) in the stabilizing gap (8) a presettable amount of stabilizer medium (M), in particular multiphase mixture (M) through the feed channel (400, 401, 402, 403) to the stabilizing gap (8) can be fed. Hybrid pump with a rotor according to one of claims 11 to 13 for a helico-axial pump (1) according to one of claims 1 to 10 for conveying a multiphase mixture (M). Method for the hydrodynamic mounting of a rotor (2) according to one of claims 11 to 13 in a helico-axial pump (1) according to one of claims 1 to 10 or in a hybrid pump according to claim 14, wherein in a pump housing (6) the rotor ( 2) is mounted rotatably about a longitudinal axis (A), and the rotor (2) for compressing the multiphase mixture (M) comprises a compression stage (K) with a helico-axial impeller (3) and a stator (4), characterized that a hydrodynamic stabilizing sleeve (70) having a stabilizing surface (700) is provided such in the pump housing (6) and configured such that prior to stabilization surface (700) is formed a stabilizing gap (8), so that in the operating state a hydrodynamic stabilization layer (S) from a stabilizing medium (M) in the stabilizing gap (8) for hydrodynamic bearing of the rotor (2) is formed.

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