WO2014094715A2

WO2014094715A2 - Multiple pump arrangement

Info

Publication number: WO2014094715A2
Application number: PCT/DE2013/000802
Authority: WO
Inventors: Helmuth Weber
Original assignee: Netzsch Pumpen & Systeme Gmbh
Priority date: 2012-12-19
Filing date: 2013-12-17
Publication date: 2014-06-26
Also published as: JP2016505756A; RU2015129345A; AU2013362364A1; BR112015012372A2; AU2013362364B2; US20150285245A1; WO2014094715A3; DE102012112618B3; JP6101363B2; KR101728260B1; WO2014094715A4; KR20150094772A; EP2935890A2; AR094087A1; CN104822942A

Abstract

The invention relates to an adaptive eccentric screw pump (2), which enables, if necessary, an increase of the output, the pressure and/or the simultaneous output of more than one output medium, and wherein the eccentric screw pump (2) has comparably low energy consumption and the production and maintenance expenditure thereof is kept low. For this purpose, according to the invention, the eccentric screw pump (2) is equipped with a modular output system, comprising at least two output modules (4, 6, 38, 40) comprising in each case one rotor (10) and one stator (8), wherein the output modules (4, 6, 38, 40) are coupled to one another and merely one actuation unit (14) is associated with the output system, and wherein the output system for an output medium has more than one inlet and/or outlet (18, 24) or at least one modular perfusion housing (12).

Description

description

Multiple pump

The invention relates to an eccentric screw pump.

Eccentric screw pumps are used in various fields, such as agriculture, the chemical industry, the food industry and papermaking. It belongs to the group of rotating positive displacement pumps and consists of a drive device essentially of a rotor and a stator. The helical rotor of the eccentric screw pump is characterized by a large pitch, large flight depth and small core diameter. The stator has a thread more relative to the rotor and has twice the pitch length of the rotor. Between the stator and the rotor, delivery chambers are thus formed, which move continuously from the inlet to the outlet side and in which the pumped medium can be transported.

The rotor of an eccentric screw pump usually consists of an abrasion-resistant material such as steel. By contrast, the stator is usually made of an elastic material such as rubber. However, stators are known from the prior art, which consist of a material or a composite material of metal and / or plastic.

The individual components of the eccentric screw pump are dimensioned and designed accordingly for the respective Förderaufgäbe. For example, the delivery rate and the achievable pressure are determined by the size and configuration of the stator and rotor. The drive device can thus be used play in two differently used eccentric screw pump designed and constructed the same. In particular, the eccentric screw pumps can achieve different delivery rates and pressures for the same number of revolutions of the rotors. If the requirements for the eccentric screw pump change because, for example, the delivery capacity has increased and the pump is no longer suitable for this purpose, then the progressing cavity pump can only be exchanged, since a conversion is generally too costly.

For example, US Pat. No. 2,483,370 discloses an eccentric screw pump with a plurality of cylinders, which are firmly integrated in a housing and in which a rotor gear is also arranged. It is considered advantageous that the pump only requires a single seal due to its design. The pump has only one outlet (exhaust port 29), which is why the pressure for all delivery modules can not be varied. The conveyor modules are subject to an eccentricity which must be compensated by the internal gear, with the result that the flow rate is limited and the pump is exposed to high wear. The pump has only one inlet (inlet port 28) for only one pumped medium and the modules can be exchanged in pairs only with a relatively high effort due to the compact design and the special drive configuration.

Also known is an eccentric screw pump with at least two pump stages connected in series (US Pat. No. 5,820,354). The volume flow from the second pump is smaller than the volume flow from the first pump. This design allows the compensation of the pumped liquid by cooling it with the help of a cooling unit (cooling system 55) which is arranged between the pump stages. Due to the cooling effect on the fluid reduces its volume and a smaller pump stage can be followed. The conveying direction and so that the inlet and outlet for the pumped medium of the pumping device can not be changed.

An eccentric screw pump with two pump sections (Pa, Pb), in which at least one inner pump rotor is enclosed by at least one outer pump rotor, wherein the pump sections (Pa, Pb) are driven at different rotational speeds of the rotors, is disclosed in WO 2009/038473 Al , The pump has an inlet (inlet flange 21) and an outlet (outlet flange 28) for conveying a fluid.

However, it would be desirable to provide a pump which can be easily and inexpensively adapted to the particular Förderaufgäbe. The pump should also be a simultaneous promotion of different products possible without the need for this purpose, several separate pumps or

Pumping devices are needed. Also, the stress of the conveyor-related components of the pump compared to a conventional eccentric screw pump should not increase significantly.

The known progressing cavity pumps or systems are but insufficiently suitable.

The invention is therefore an object of the invention to provide an eccentric screw pump, with the need to increase the flow, the pressure and / or the simultaneous delivery of more than one fluid is possible, the eccentric screw pump has a relatively low energy consumption during operation of the eccentric screw pump and their production and maintenance costs are kept low.

This object is achieved according to the invention by proposing an eccentric screw pump which is equipped with a modular conveyor system containing at least two each comprising a rotor and a stator comprising conveyor modules, wherein the conveyor modules are coupled together and the conveyor system is associated with only one drive device and wherein the conveyor system for a pumped medium has more than one input and / or output or at least one modular flow housing.

As a delivery module while the rotor-stator assembly is seen, with the help of the conveyed medium is transported. As a result of the eccentric screw pump according to the invention and the use of more than one delivery module, different products but also identical products from different sources can be conveyed simultaneously. In addition, the achievable pressure of the pump can be increased by a series connection of several conveyor modules. The conveyor modules are coupled to each other for this purpose, such that only a drive device is required for their drive.

The invention is based on the consideration that an adaptation to the respective Förderaufgäbe is particularly easy to implement by a modular conveyor system. The inputs and outputs for the pumped medium and the number of conveyor modules should be substantially expandable and combinable as desired. By means of a modular system made available in this way, the pump can be effectively matched to the requirements of the user.

This is achieved by at least two conveyor modules being coupled together. The conveyor modules each comprise a stator and a rotor, wherein the rotor is driven by only one drive device. For this purpose, the rotors are connected to one another in order to transmit the forces occurring during operation of the eccentric screw pump, in particular the torque forces generated by the drive device. Preferably, the conveyor modules in such a way with each other coupled, that between the respective rotors of the conveyor modules and a rotation angle-dependent pressure pulsation caused vibrations, a phase difference of 180 ° is achieved. Since the frequency of the vibrations is the same, due to the fact that only one drive system is used, so the vibrations are reduced to a minimum.

Preferably, the conveyor modules via suction pressure or flow housing are coupled together. This has the advantage that depending on Förderaufgäbe the eccentric screw pump can be mounted individually. The suction and pressure housings are provided with a connecting piece for connection to the delivery lines. Thus, a suction line can be connected to the suction housing and a pressure line to the pressure housing.

By a suitable combination and selection of the housing an adaptation or change of the eccentric screw pump in dependence on the respective Förderaufgäbe with a relatively low effort is possible. The conveyor modules can optionally be coupled together with a pressure, suction or flow-through housing, or finally provided with a pressure or suction housing. In addition, the conveyor modules can be designed differently, so that at the same rotational frequency of the rotors, the delivery rates of the conveyor modules are different. If different products are promoted, a certain mixing ratio can be set.

The rotors associated with the conveyor modules are preferably coupled to each other via a rigid connection within the housing, so that transmission of the forces acting on the rotor by the drive device is possible without play and loss. The rotors may be formed by any rigid or rigid connection known in the art be coupled, which is suitable depending on the application to transmit torques or torques and axial forces. As an example, let us look at material connections such as

Welded, glued or soldered joints or on non-positive and / or positive connections such as a screw, clamp or pin connections noted. Of course, the rotors can also be connected to each other by joints.

In a preferred embodiment, the rotors are releasably connected to each other. The assembly and disassembly of the conveyor modules is thereby simplified and improved. Thus, it is possible to convert the eccentric screw pump according to the invention according to a changed Förderaufgäbe.

In a further embodiment, it is proposed to form the rotor in one piece for at least two conveyor modules. Since there are no connection points, this design is particularly well suited for the promotion of, for example, abrasive and aggressive media. During assembly, the housings and stators are pushed over the one-piece rotor. As a delivery module, the stator is considered in this particular embodiment, even if the delivery module fulfills its function only after assembly, together with the respective rotor section.

The eccentric screw pump is preferably configured such that the axial force F acting in the direction of the drive device approaches zero or at least is reduced. This is achieved by the fact that each two conveyor modules, in the same speed and the same sense of rotation of the rotors, promote in opposite directions. For this purpose, the conveyor modules on opposite slopes. In an eccentric screw pump with, for example, two conveyor modules, one conveyor module has a left and the other conveyor module Right turn on. The axial forces which occur during operation of the eccentric screw pump in each case per delivery module act in opposite directions and cancel out almost completely when identical delivery modules are used. Under similar is, apart from the different pitch, to understand a particular embodiment and dimensioning of the conveying elements. The axial force resulting on the drive side then approaches zero, which is why cost-intensive bearing elements of the drive device, for example, which essentially comprise a drive component and a pump housing with connecting pieces, can be replaced by more cost-effective bearing elements. As a result, the total load of the drive device is significantly reduced.

Particularly preferred in the proposed eccentric screw pump, the conveyor modules are arranged in series. The torque transmission from the drive device to the rotors or to the rotor can be kept particularly simple. For example, it is also possible, as already proposed, to form the rotor in one piece. For all conveying elements of the eccentric screw pump only one rotor is thus required in this embodiment.

In a further preferred configuration, two adjacent conveyor modules are coupled to one another via a flow-through housing and configured for the same conveying directions. The slopes are identical for both conveyor modules, preferably, the conveyor modules have a left slope. The product is thus conveyed via the inlet connection of the pump housing into a first delivery module, through a flow-through housing and a second delivery module in one direction. Since each delivery module represents a pressure stage, the resulting pressure can be increased by connecting several delivery modules in series. Furthermore, it may be advantageous to couple two adjacent conveyor modules via a suction or pressure housing with each other, wherein the conveyor modules are configured for opposite conveying directions. The gradients are different for both conveyor modules. Thus, the eccentric screw pump may include a first conveyor module with a left slope and a second conveyor module with a right slope, both of which are coupled together via a pressure housing, so that the fluid is conveyed through the conveyor modules towards the pressure housing. In a second embodiment, the eccentric screw pump may comprise a first delivery module with a right pitch and a second delivery module with a left slope, both being connected via a suction housing, so that the delivery medium is sucked in by the delivery modules and conveyed in opposite directions.

In an advantageous embodiment, the eccentric screw pump comprises only two conveyor modules. Even if only two conveyor modules are used, the eccentric screw pump can be configured according to the respective requirements of the Förderaufgäbe and yet has a compact design.

For example, the eccentric screw pump can be configured to achieve twice the delivery capacity with the same simple speed and pressure, compared to a conventional progressive cavity pump, with the same speed and direction of rotation. For this purpose, a first conveyor module coupled to the drive device has a left-hand pitch and a second conveyor module connected in series has a right-hand pitch. Both conveyor modules are coupled together via a pressure housing. The second delivery module has a suction housing at its end opposite the pressure housing. As with a conventional eccentric screw pump, the pumped medium sucked in via a suction nozzle on the pump housing, but here additionally via a suction nozzle on the suction housing. The pumped liquid is thus promoted in the operating state of the pump coming from two sides to the pressure housing and exits via a pressure port on the pressure housing. In this way, different fluids can be supplied. The fluid or the media are merged, with a mixing ratio can be adjusted by a suitable choice of the conveyor modules.

However, it is also possible to configure the eccentric screw pump, which achieves twice the pressure with a simple delivery rate, as in the case of a conventional eccentric screw pump. The eccentric screw pump is equipped with two conveyor modules of the same pitch, preferably left-hand pitch. Both conveyor modules are coupled together via a flow housing. The second delivery module has a pressure housing at its end opposite the throughflow housing. In this variant, the fluid is sucked in via the suction port of the pump housing and conveyed via the first delivery module, the flow-through housing and the second delivery module to the pressure housing, which is provided with a discharge nozzle.

In a further variant, the eccentric screw pump comprises a total of four conveyor modules. This makes it possible, depending on the configuration, in comparison to a conventional eccentric screw pump, either four times the flow rate at the same pressure or twice the flow rate at double pressure can be achieved.

In order to achieve the fourfold delivery, two conveyor modules with different pitch are coupled to each other via a pressure housing, the two pairs of conveyor modules thus formed in turn are connected to each other via a suction housing coupled. At the opposite end of the drive device of the eccentric screw pump, a further suction housing is arranged. The pumped liquid can thus be conveyed via a total of three suction nozzles and two discharge nozzles. The conveyor modules preferably have the gradients left-right-left-right from the first to the fourth conveyor module.

In addition to the preferred embodiment of the eccentric screw pump equipped with a total of four conveyor modules, in which the pumping system comprises two suction and two pressure housing, in a further advantageous embodiment, the conveyor modules via a suction, two Durchströmungs- and a pressure housing are coupled together. In each case two conveyor modules with the same pitch are coupled via a flow-through housing, the two conveyor module pairs thus formed in turn via a pressure housing with each other. At the opposite end of the drive device of the eccentric screw pump, a suction housing is arranged. The conveyor modules preferably have the slopes left-left-right-right.

The eccentric screw pump preferably has mixing means coupled to the rotor in the coupling region of the conveyor modules. This makes it possible that the fluid or the media to be mixed during transport. This is particularly advantageous when two different products, for example when the one product via a first suction housing and the other product via a second suction housing, are introduced into the eccentric screw pump. For particularly effective mixing of the products, the means for mixing is located within the pressure housing and directly coupled to the rotor. A separate drive is therefore not required.

According to a preferred embodiment, the housing are formed substantially identical. In particular, suction and pressure housing identical and are defined only by the nature of their use. In contrast, the flow-through housing is preferably formed from a suction or pressure housing by the suction or discharge nozzle is provided with a closure means. For example, the closure means may be formed as a blind flange, which is fastened via a flange on the housing neck.

The advantages achieved by the invention are, in particular, that a delivery of different pumped media, in a certain predefined mixing ratio, can be realized with only one pumping system. The pumping system can be particularly easily adapted to the conveying tasks by the number and selection of the conveying modules and the coupling means. Due to the fact that the delivery rate and delivery speed of a progressive cavity pump are determined and influenced by various factors such as the geometry and pitch of the rotor and stator, the delivery rate can be set particularly easily with the aid of the modular pump structure. Through the use of delivery modules with different delivery rates, the mixing ratio of the pumped media can be influenced. In addition, a cost saving is possible. It can save energy and material costs, since the inventive modular design of the eccentric screw pump manages without coupling rods and joints and thus the number of moving parts in the fluid is kept comparatively low. The negative impact on the efficiency of the pump and its life frictional forces are thereby reduced. The conveyor modules can be arranged so that the axial forces cancel out almost completely. By reversing the direction of rotation of the rotor or the rotors, the conveying direction can be changed.

Another advantage is that only one sealing system on the suction side of the drive system is required and serviceable. For example, by using the eccentric screw pump according to the invention as a so-called submersible pump, with the same pipe diameter or drilling or bunghole, the flow rate can be doubled.

Embodiments of the present invention will be described by way of example with reference to the accompanying drawings, in which:

FIG. 1 shows an eccentric screw pump with two delivery modules, which are coupled to one another via a throughflow housing and a pressure housing is arranged, an eccentric screw pump with two m conveying modules in opposite directions, which are coupled together by means of a pressure housing and at the end of a suction housing, an eccentric screw pump with two conveying in opposite directions conveyor modules which are coupled together by means of a pressure housing and at the end of a suction housing is arranged with a compensating coupling to a drive device, an eccentric screw pump with a total of four conveyor modules, which via a suction and two pressure housing together are coupled and at the end of a suction housing is arranged, FIG. 5 shows an eccentric screw pump with a total of four delivery modules which are coupled to one another via a pressure and two flow-through housing and at the end of which a suction housing is arranged,

Figure 6 is a known from the prior art conveyor system, in which a total of four eccentric screw pumps are connected in parallel.

The device according to FIG. 1 shows an eccentric screw pump 2 with a first and a second delivery module 4, 6, each comprising a stator 8 and a rotor 10, which are coupled to one another via a flow-through housing 12. At the end of the eccentric screw pump 2 opposite a drive device 14, a pressure housing 16 with a pressure connection 18 is arranged on the second delivery module 6. Both conveyor modules 4,6 are of identical design and have a left-hander L on. The flow-through housing 12 is a

Pressure housing or a suction housing, which is provided with a closure means 20. The closure means 20 should be arranged close to the pressure housing in order to avoid dead space, which adversely affect the flow path and by the medium can settle.

The eccentric screw 2 is equipped with feet not shown here. The unused for the promotion nozzle of the flow housing 12 can be used advantageously as a stand or as a basis for the mounting of a stand.

The conveyor system composed essentially of the conveyor modules 4, 6 and the housings 12, 16 is coupled to the drive device 14, which encloses a pump housing 22 with a suction nozzle 24 and a drive component 26. summarizes. The power transmission to the rotor 10 of the first conveyor module 4 takes place by means of drive shafts 30 coupled via joints 28. Furthermore, the drive device 14 is provided with a seal 32 in order to prevent the conveying medium from escaping to the outside.

The rotors 10 of the conveyor modules 4, 6 are connected to one another via a rigid coupling 34. During operation of the eccentric screw 2, the fluid passes from a suction line, not shown here via the suction port 24 into the pump housing 22 and is conveyed by means of the conveyor modules 4,6 through the flow housing 12 through to the pressure housing 16, where it then via the discharge port 18 in a pressure line, not shown here is transported. The axial forces occurring counteract the conveying direction and are absorbed by a bearing provided for this purpose. Since the conveyor modules 4, 6 are connected in series in this embodiment, a double pressure is achieved compared with a conventional eccentric screw pump equipped with only one rotor-stator arrangement.

An eccentric screw pump 2 with two conveying modules 4, 6 coupled via a pressure housing 16 is shown in FIG. The first conveying module 4 has a left-hand pitch L and the second conveying module 6 has a right-hand pitch R. The rotors 10 are connected to each other via a rigid coupling 34. At the drive device 14 opposite end of the eccentric screw pump 2, a provided with a suction port 24 suction housing 36 is arranged. As in the case of the eccentric screw pump 2 shown in FIG. 1, the pump housing 22 has a further suction port 24.

Due to the different left-right slopes L, R of the conveyor modules 4, 6, the housing arranged at the end of the eccentric screw pump 2 acts as a suction housing 36. The pumped medium is thus transported via the two suction nozzle 24 into the pressure housing 16 and conveyed through the discharge port 18.

Despite the same direction of rotation of the rotors 10, which are driven by a common drive device 14, the pumped media are transported in opposite directions. As a result, the axial forces occurring during operation of the eccentric screw pump 2 and acting on the rotors 10 counteract, whereby the resultant force acting on the bearings of the drive device 14 approaches zero or is at least reduced. The coupling 34 for the rotors 10 should be designed so that they can absorb the tensile forces occurring. Advantageously, so that the drive shafts 30, joints 28 and bearing 32 are less stressed, resulting in less wear. Also, the components of the eccentric screw 2 can be dimensioned correspondingly cheaper. In the pressure housing 16, a means for mixing is arranged in the region of the coupling 34, which is coupled to the rotors and is designed as a stirring element 37. Since the conveyor modules 4, 6 are connected in parallel in this embodiment, a double delivery capacity is achieved compared with a conventional eccentric screw pump.

As an alternative embodiment, not shown here, using the example of FIG. 2, the rotor 10 may also be formed in one piece. Thus, a coupling 34 can be dispensed with. The rotor 10 has for this purpose two sections for the conveyor modules 4,6. A first section with a left slope L and a second section with a right slope R.

FIG. 3 shows an eccentric screw pump 2 as shown in FIG. 2, but with a different drive device 14. The drive device has a compensation coupling 33 for transmitting the torque to the rotors. Due to the compact Design of the drive device 14, the extended design of the eccentric screw pump 2, by the series-connected conveyor modules 4,6, are almost completely compensated.

4 shows an eccentric screw pump 2 with a total of four conveyor modules 4,6,38,40 shown, wherein two analogous to the embodiment in Figure 2 by means of pressure housing 16 coupled conveyor modules are coupled together via a suction housing 36, such that the conveyor modules 4, 6,38,40 of the conveyor system of the drive device 14, starting the slopes left-right-left-right. At the drive device 14 opposite end of the eccentric screw pump 2, a suction housing 36 is arranged with a suction nozzle 24. The rotors 10 are connected by rigid couplings 34. The fluid is conveyed over a total of three suction port 24 and two discharge ports 18. Since the four conveyor modules 4,6,38,40 are connected in parallel in this embodiment, a four times the capacity compared to a conventional eccentric screw pump is achieved. Due to the same number of conveyor modules

4,6,38,40 with a left and a right slope, the resultant force acting on the bearings of the drive device 14 approaches zero or is at least reduced.

A further alternative embodiment with a total of four conveyor modules 4, 6, 38, 40 is shown in FIG. In this embodiment, two each coupled via a flow housing 12 and connected in series conveyor module pairs, a first conveyor module pair 4,6 and a second conveyor module pair 38,40, coupled to each other by means of a pressure housing 16. The conveyor module pairs 4, 6 and 38, 40 connected in series have different pitches, so that the conveyor system comprises a total of conveyor modules 4, 6, 38, 40 with the slopes left-left-right-right. During operation of the eccentric screw 2, the pumped liquid is sucked by means of the suction nozzle 24 on the suction housing 36 and the pump housing 22 and transported away via only a discharge port 18. Since in this embodiment, two conveyor modules are connected in series and thus formed two conveyor module pairs represent a parallel circuit, a double compared to a conventional eccentric screw pump and a double pressure is achieved. Due to the same number of conveyor modules 4,6,38,40 with a left and a right slope, acting on the bearings of the drive device 14 resulting force goes to zero or is at least reduced.

FIG. 6 shows, for comparison, an arrangement known from the prior art with a plurality of identical eccentric screw pumps 42 of the same design. As can be seen by the dashed lines of flow of the pumped medium, the total of four progressing cavity pumps 42 are connected in parallel to achieve four times the capacity compared to a simple eccentric screw pump. Compared to the modular eccentric screw pump 2 according to the invention, the arrangement known from the prior art has, inter alia, a disadvantageously high energy requirement for operating the pump, high production and maintenance costs and a high space requirement.

Each of the four eccentric screw pumps 42 each comprise a drive device 14, a rotor-stator arrangement 44 and an end opposite to the drive device 14 arranged pressure housing 16, which is provided with a pressure port 18. The fluid is sucked through the suction port 24 on the pump housing 22 and conveyed in the direction of the pressure housing 16, from where it is transported via the discharge port 18 in pressure lines, not shown here. The device according to the invention is specifically geared to an eccentric screw pump 2, which can be used flexibly and can be saved with the costs and effort. Due to the particularly simple modular design, the eccentric screw 2, by the number and selection of suitable conveyor modules 4,6,38,40 and housing 16,36, the respective Förderaufgäbe be adjusted. All that is required is only one drive device 14, which above all keeps the energy and maintenance requirements comparatively low. Due to the mutual arrangement of conveyor modules with different gradients L, R, the axial forces acting on the bearings of the eccentric screw pump can also be reduced.

LIST OF REFERENCE NUMBERS

02 eccentric screw pump

04 First conveyor module

06 Second conveyor module

08 stator

10 rotor

12 flow housing

14 drive device

16 pressure housing

18 discharge nozzles

20 closure means

22 pump housings

24 suction nozzles

26 drive component

28 joints

30 drive shafts

32 seal

33 compensating coupling

34 clutch

36 suction housing

37 stirring element

38 Third funding module

40 Fourth delivery module

42 eccentric screw pump (prior art)

44 Rotor-stator arrangement (prior art)

Claims

claims

1. eccentric screw pump (2) with a modular conveyor system, comprising at least two respective rotor (10) and a stator (8) comprising conveyor modules (4,6,38,40), wherein the conveyor modules (4,6,38,40) coupled to each other and the conveyor system is assigned only a drive device (14) and wherein the conveyor system for a pumped medium more than one input and / or output (18,24) and at least one modular flow housing (12).

2. eccentric screw pump (2) according to claim 1, wherein the conveyor modules (4,6,38,40) in each case via a suction housing (36), pressure housing (16) or flow-through housing (12) are coupled together.

3. Eccentric screw pump (2) according to claim 1 or 2, wherein the rotors (10) of the conveyor modules (4,6,38,40) in the suction housing (36) or pressure housing (16) via a rigid connection (34) are coupled together ,

4. eccentric screw pump (2) according to claim 3, wherein the rotors (10) are detachably connected to each other.

5. Eccentric screw pump (2) according to claim 1 or 2, wherein the rotor (10) for the conveyor modules (4,6,38,40) is integrally formed.

6. eccentric screw pump (2) according to claim 1 to 5, wherein, by the selection and configuration of the conveyor modules (4,6,38,40), a certain mixing ratio of the pumped media is adjustable.

7. eccentric screw pump (2) according to claim 1 to 6, wherein the in the direction of the drive device (14) acting axial force goes to zero.

8. eccentric screw pump (2) according to claim 1 to 7, wherein the conveyor modules (4,6,38,40) are arranged in series.

9. Eccentric screw pump (2) according to claim 1 to 8, wherein two adjacent conveyor modules (4,6,38,40) via a suction housing (36) or pressure housing (16) coupled together and configured for opposite conveying directions.

10. Eccentric screw pump (2) according to claim 1 to 8, wherein two adjacent conveyor modules (4,6,38,40) via a flow-through housing (12) are coupled together and configured for the same flow directions.

11. Eccentric screw pump (2) according to claim 1 to 10, wherein the conveyor system comprises two conveyor modules (4,6,38,40).

12. Eccentric screw pump (2) according to claim 11, wherein the conveyor system comprises a pressure housing (16) and a suction housing (36).

13. Eccentric screw pump (2) according to claim 11, wherein the conveyor system comprises a pressure housing (16) and a flow-through housing (12).

14. eccentric screw pump (2) according to claim 1 to 10, wherein the conveyor system comprises four conveyor modules (4,6,38,40).

15. Eccentric screw pump (2) according to claim 14, wherein the conveyor system comprises two suction housing (36) and two pressure housing (16).

16. Eccentric screw pump (2) according to claim 14, wherein the conveyor system comprises a suction housing (36), two flow-through housing (12) and a pressure housing (16).

17. Eccentric screw pump (2) according to claim 1 to 16, wherein in the coupling region of the conveyor modules (4,6,38,40) with the rotor (10) coupled means for mixing (17) are arranged.

18. eccentric screw pump (2) according to claim 17, wherein the means for mixing in the pressure housing (16) are arranged.

19. Housing (12, 16, 36) for a conveyor system of an eccentric screw pump (2) according to one or more of claims 1 to 18.