KR20170096638A - Eccentric screw pump with automatic adjustment system, and adjustment method - Google Patents

Abstract

The present invention relates to an eccentric screw pump including a rotor with a rotor screw and a stator / rotor system including a stator with a female thread. The stator includes a strut member and an elastomeric portion, the strut member completely surrounding the elastomeric portion in some areas. According to the present invention, the stator / rotor system includes an adjustment mechanism for adjusting the stator. The adjustment mechanism is connected via one open loop controller to one or more sensors for detection of actual operating parameters of the stator / rotor system and / or the eccentric screw pump, and the actuation of the adjustment mechanism is determined by the actual operation Can be executed through the open loop controller taking into account the parameters. The present invention also relates to a method for adapting the operating state of an eccentric screw pump.

Description

Eccentric screw pump with automatic adjustment system, and adjustment method

The present invention relates to an eccentric screw pump according to the features of the preamble claims 1 and 7 and to a method for adapting the operating state of the eccentric screw pump.

The present invention relates to an eccentric screw pump for the transport of liquid and / or granular media.

Eccentric screw pumps are pumps for the transport of a multitude of media, such as mud, liquor, crude oil and grease, especially viscous, high viscosity and abrasive media. In this case, the driven spiral rotor moves in rolling contact with the stator. The stator is a housing including a spirally-coiled inner side. In this case, the rotor performs its eccentric rotational motion around the stator axis with its own figure axis. The external screw, i. E. The stator has the form of a double-start thread, for example, whereas the rotor screw is just a sinbgle-start thread. The rotor is typically constructed of a high abrasion resistant material, such as steel. Conversely, the stator is made of an elastic material, such as rubber. Through the special formation of the rotor and the stator, sealed hollows are formed between the rotor and the stator, which transfer the medium while being moved axially during rotation of the rotor. In this case, the volumes of the hollow portions are constant, whereby the conveying medium is not squeezed. If the dimensional design is suitable, not only the fluid but also the solid can also be transported by the eccentric screw pumps.

The rotor is adjacent to the inner wall of the stator, which is formed through the elastic material in a pressurized manner, so as to enable the delivery space to be formed and to transport each medium with as little backwash as possible. Due to the movement of the rotor, which is typically a metal in the interior of the stator, which is typically made of rubber or similar material, a certain wear or tear of the stator occurs. The contact pressure between the rotor and the stator is reduced through wear, and in particular the contact between the stator and the rotor can not be maintained along a continuous spiral contact line, thereby reducing the performance of the eccentric screw pump. This applies especially to eccentric screw pumps which must overcome high suction heights or high backpressure. For this reason, the stator must be replaced and replaced at regular intervals.

Sensors are used to determine the stator's replacement time, e.g., to detect wear of the stator in accordance with physical parameters. DE 10157143 A1 describes a device for indicating maintenance intervals or remaining operating periods of eccentric screw pumps. The sensors detect wear-related operating parameters that are detected by the sensor unit. The sensor unit determines the expected values of the operating periods or operating periods until the expiration of the next maintenance, or the exchange of the specific parts, in accordance with the above parameters.

DE 202005008989 discloses an eccentric screw pump which monitors the operability and wear of the stator, in which case the stator is provided with a stator having one or more A measurement transducer is assigned.

Additional possibilities of sensor based monitoring of the stator state are described, for example, in documents JP 2011112041 A, JP 2010281280 A, JP 2009235976 A and JP 20101104 A.

In addition, to make the stator relatively longer available, readjustable stators are also known. DE 3433269 A1 describes a stator casing comprising tensioning devices in the form of tension bolts, which are distributed over the entire axial length of the stator casing. This causes an obvious increase in weight of the stator / rotor system. In addition, for readjustment, all tensioning devices must be individually tightened again.

EP 0292594 A1 discloses a stator casing provided with longitudinal slots for eccentric screw pumps, the stator casing having only a tensioning device for pressure regeneration at the time of worn of the stator only in its own pressure region . The tension is partially distributed over the length of the stator casing through suitable reinforcing ribs.

DE 4312123 A1 describes a stator casing comprising a plurality of slots extending in the longitudinal direction to simplify readjustment. The slots are terminated immediately before the end of the suction side end of the stator and are freely terminated only at the pressure side end in order to allow the reconditioning to be carried out more suitably in the region of the pressure side end of the stator.

DE 4403979 A1 discloses a reconfigurable stator for eccentric screw pumps, which comprises successive longitudinal slots and longitudinal slots which terminate slightly in front of the intake side end of the stator. Preferably each one longitudinal slot is followed by one continuous slot.

It is an object of the present invention to achieve a simple and rapid adaptation of the stator / rotor system to operating conditions.

This problem is solved by a stator / rotor system comprising the features of claims 1 and 7 and a method for adapting the operating state of the stator / rotor system. Further preferred embodiments are described through dependent claims.

The present invention relates to an eccentric screw pump including a stator / rotor system. The stator / rotor system includes a rotor with a rotor screw and a stator. According to one preferred embodiment, the stator / rotor system includes a rotor with a single row threaded rotor screw and a stator with a double row threaded female threaded portion. The stator comprises at least two members and includes a strut member and an elastomeric portion. According to one embodiment of the present invention, the elastomeric portion of the stator is disposed within the stator casing and generally does not include a fixed connection to the stator casing. Instead of a stator casing, a fabric part, or a lattice structure that at least partially surrounds the elastomeric part, may also be used as the stiffening member. In other words, the stiffening member or stator casing and the elastomeric portion are generally formed as discrete components. The stiffening member or stator casing completely surrounds the elastomeric portion at least in some areas. In particular, the stiffening member or stator casing surrounds most of the elastomeric portion so that only the free outer end regions of the elastomeric portion are more projected than the stiffening member or stator casing and are not surrounded by the stiffening member or stator casing.

In particular, the stator is a stator system such as that described in DE 102005042559 A1. On the basis of the absence of a fixed connection between the elastomeric portion and the stiffening member or stator casing, the axial deformation of the elastomeric portion is possible. During deformation, the volume of the stator remains the same. Thus, the axial deformation of the elastomeric portion results in a cross-sectional variation of the oblong hole of the elastomeric portion into which the rotor is guided. Thus, in addition to compensating the wear of the stator, the pre-tensioning between the stator and the rotor, i.e., the pressing force, can be varied, i.e., the reconditioning or adjustment of the stator can be achieved by varying the pre-tensioning between the stator of the eccentric screw pump and its rotor And may also be used to adapt to operating conditions.

The stator / rotor system of the eccentric screw pump includes an adjustment mechanism for variable and readjustment of the pre-tensioning of the stator. Depending on the respective operating conditions of the eccentric screw pump, another pretensioning of the stator / rotor system is required. Pretensioning is determined, for example, by the viscosity of the product being conveyed, the product mixture, and the like. The operating condition is determined in particular by several operating parameters such as pressure, rotational speed, torque and / or additional operating parameters. The adjustment mechanism is connected to the closed-loop control system and is operated and controlled through the closed-loop control system. In particular, the closed loop control system includes at least one sensor for detection of actual operating parameters of the stator / rotor system and / or the eccentric screw pump, and an open-loop controller for adjustment of the adjustment mechanism. In other words, the adjustment mechanism is connected via the open loop controller to one or more sensors for detection of actual operating parameters of the stator / rotor system and / or the eccentric screw pump. The actuation of the adjustment mechanism is performed through the open loop controller, taking into account the actual operating parameters detected by the one or more sensors.

The closed loop control mechanism according to the present invention establishes a correlation between the various physical operating parameters of the stator / rotor system and the pre-tensioning between the stator and the rotor, or the state of wear of the stator. For example, a correlation is established between physical operating parameters such as pressure, torque, flow rate, rotational speed and / or viscosity and the state of wear of the stator or pretensioning between the stator and the rotor. The most direct parameter to combine the correlations together is the tensile state in the elastomeric material. The tension can be measured directly through a suitable sensor device in the elastomeric material or can be determined indirectly through the repulsion of the elastomer to another part and can be determined, for example, for the stator wall, Through the repulsive force of the elastomer or through the repulsive force of the elastomer to one end face of the end faces of the elastomeric portion, for example by means of two shells, closure for engaging the stiffening member or stator casing ), And the like.

Closed loop control algorithms according to the present invention enable the correlation to be set from, for example, pressure, torque, flow rate, rotational speed and pre-tensioning present in the elastomer, and thus to be suitable for adjusting the optimum operating point A corresponding adjustment position for adjustment of the adjustment mechanism is determined. After the automated adjustment of the adjustment mechanism, the physical operating parameters of the eccentric screw pump are again measured, from which it is determined whether an optimum operating condition is achieved. If the measured operating parameters do not correspond to the desired set-up parameters, the adjustment path is again calculated and the adjustment mechanism is adjusted accordingly.

According to one preferred embodiment of the present invention, the actual control parameter is a tension state predominantly present in the elastomer, such tension state being measured, for example, in an indirect form, and may include additional operating parameters such as, for example, the rotational speed of the eccentric screw pump To provide an adjustment path (x) and / or an adjustment direction to incrementally approach the desired setpoint.

Preferably, the adjustment of the calculated adjustment path (x) and / or the adjustment direction is performed with an incremental approach. In particular, a gradual approach to optimal adjustment of the adjustment mechanism is performed. If the deviation between the set value and the actual value is out of the specified tolerance range, the adjustment mechanism is adjusted by the predetermined offset value. The closed loop control algorithm according to the present invention determines the direction of the adjustment based on the comparison between the set value and the actual value and the data stored inside the closed loop control algorithm, and the magnitude of the adjustment corresponds to a predetermined cut-off value. In this way, an incremental approach to the desired setpoint is performed, in particular, only if the measured deviation between the setpoint and the actual value is within the specified tolerance range.

According to one preferred embodiment, the adjusting mechanism comprises two adjusting members which are arranged on the stator / rotor system and in which the spacing between them can be varied. In the first operating position, the two adjusting members have a first spacing distance between them, and in the second operating position, the two adjusting members have a second spacing distance between them, and the first spacing distance is not equal to the second spacing distance. The cross-section and length of the elastomeric portion of the stator in the second operating position are varied relative to the cross-section and length of the elastomeric portion in the first operating position.

Preferably, there is a mechanical coupling and / or connection between the adjusting mechanism and the stator, and in particular the mechanical coupling and / or connection is between the adjusting mechanism and the elastomeric part of the stator. By varying the relative spacing between the two adjustment members of the adjustment mechanism, variations in the cross-section and length of the elastomeric portion of the stator are realized.

Preferably, one of the adjusting members is disposed in a fixed manner on the stator / rotor system and the other adjusting member is disposed in a position-variable manner on the stator / rotor system. In particular, the first adjusting member is disposed in a fixed manner on the stiffening member or the stator casing, and the second adjusting member is disposed in a position-variable manner on the elastomer portion of the stator. According to one preferred embodiment, the first adjusting member is arranged in a fixed manner on the flange on the free end of the stator member or the stator casing, and the second position variable adjusting member is arranged on the free end of the elastomer portion of the stator.

According to one embodiment of the present invention, through the open loop controller, realization of the repositioning of the second position variable adjustment member and thus realization of the variation of the relative distance between the second position variable adjustment member and the first fixed type adjustment member Actuator is activated. The adjustment of the relative spacing between the two adjustment members can be performed in different types and schemes. Actuators include, for example, wedge members, wedge rings, mechanisms including spindle adjustment, cylinder assist mechanisms, and the like.

According to one embodiment of the present invention, one or more first sensors capable of detecting specific physical parameters of the stator / rotor system may be disposed on the stationary component of the eccentric screw pump, which is assigned to the stator / rotor system. Alternatively, or in addition, one or more second sensors may be disposed on the stator / rotor system, particularly on the elastomeric portion of the stator. Alternatively, or in addition, one or more third sensors may be disposed on the adjustment mechanism.

For example, the at least one first sensor is configured to measure pressure, rotational speed, torque, temperature and / or volumetric flow rate of the eccentric screw pump, while at least one second sensor is configured to measure pre- Directly or indirectly. The second sensor may be, for example, a piezoelectric element, a load cell or a dielectric elastomer. The second sensor may also be formed in a manner that results in a repulsive force of the elastomeric material being measurable, while at least one third sensor is adapted to measure the position of the second positionable adjustment member and / Or to measure the relative spacing distance between the first fixed type adjusting member and the second position variable adjusting member.

The present invention also relates to a method for adapting the operating state of an eccentric screw pump including the stator / rotor system described above.

First, the actual operating state of the eccentric screw pump is inquired. In this case, one or more physical actual operating parameters associated with the eccentric screw pump and / or one or more physical actual operating parameters relating to the elastomeric portion of the stator / rotor system, and / or one or more physical actual operating parameters Is measured with a sensor. The actual operating parameters detected by the sensor are then known or compared to the desired set operating parameters. The comparison is performed in particular according to the data stored in the open loop controller. During the comparison, if a deviation between the actual operating parameters and the set operating parameters is detected, the actuation of the adjusting mechanism for adjusting the stator is performed. In this case, the adjustment of the new operating state is monitored by checking one or more physical actual operating parameters.

According to a first preferred embodiment, when a deviation between measured actual operating parameters and set operating parameters is detected, the necessary adjustment of the adjustment path of the adjustment mechanism is calculated, the adjustment mechanism is operated correspondingly, The calculated adjustment path is adjusted, leading to readjustment or adjustment of the stator, in particular to variations in the cross-section and length of the elastomeric portion of the stator.

According to one alternative embodiment, the operating condition is adjusted through an incremental approach to the ideal operating point. In this case, the following functional principle becomes the basis of the closed loop control principle or the closed loop control algorithm. In other words, the volume flow rate is assigned to the first rotational speed of the eccentric screw pump. Particularly in this case, in the case where the volume efficiency is 100%, the volume flow rate may be a volume which is exactly transferred from the suction side to the pressure side of the eccentric screw pump corresponding to the rotational speed through the individual transfer members (transfer chambers).

Now, the optimum adjustment of the operating point of the eccentric screw pump is performed as follows. In short, observing the volumetric flow rate over a certain adjustment range under conditions where the rotational speed is constant, at least a substantially constant point over the relatively longer range of the volumetric flow rate is ascertained. However, the drive torque required for this is not constant. If the pre-tensioning is extinguished, the torque decreases through the relatively lower friction loss due to the reduced pretensioning. The efficiency of the eccentric screw pump increases because the backflow does not occur at all or only slightly occurs in the range where the volumetric flow rate does not vary. The efficiency of the eccentric screw pump decreases only when the reduced pre-tensioning reaches an operating point where backflow occurs more and more. The point of maximum efficiency can be expressed explicitly as follows. In short, the ideal operating point of the pump is exactly when there is just that much pretensioning between the rotor and the stator, so that backflow does not occur at all or only to a minor degree. In other words, the ideal operating point is the point at which pretensioning is created to produce the required backpressure in the rotor / stator system as little backwash as possible of the medium directly.

The functionality is used for a closed loop control algorithm, and in particular an incremental approach is performed to adjust the ideal operating state. In accordance with one embodiment of the present invention, the closed loop control algorithm preferably utilizes the measurement principle described below. In short, first, specific operating parameters of the eccentric screw pump are detected. For example, measurements of pressure, rotational speed, torque (motor current) or other operating parameters are performed using suitable sensors. For example, the volume flow rate can also be detected by a volumetric flow meter, a measurement diaphragm, and the like.

The adjustment mechanism now moves to an at least substantially closed position, e.g., where the two adjustment members are maximally approaching each other. As a result, the rubber of the elastomeric portion is compressed, thereby increasing pre-tensioning in the stator / rotor system and thereby countercurrent flow is minimized.

After ensuring that the area of sufficient compression is adjusted, the adjustment mechanism is reopened in a slow and controlled manner. In this case, the volumetric flow rate remains largely constant until initially reaching a certain point. At certain points, the volumetric flow rate drops because the back flow in the stator / rotor system increases. The ideal operating point is located just before the drop point. The ideal operating point can be seen as a specific area where the eccentric screw pump exhibits its highest efficiency.

Preferably, the adjustment of pretensioning is carried out independently through the adjustment system within the rotor / stator system at the determined time intervals. Thus, active adjustment or adaptation to varying operating conditions of the pump can be ensured.

Alternatively, the pretensioning of the rotor / stator system is increased until the maximum volume flow rate is reached, according to the measured operating parameters and the incremental adjustment procedure. When the peak value of the volumetric flow rate is reached, the pretensioning is increased by the adjustment increment of the predetermined number of times again. This ensures that the iBP (ideal operating point) is exceeded. The iBP is then determined and adjusted through incremental dissipation of pretensioning. This procedure is repeated at defined time intervals. Thereby, a response is made to the varying operating conditions.

According to one preferred embodiment, following the adjustment of the adjustment mechanism, after a defined time interval, a comparison is made between the actual operating state of the eccentric screw pump and the set operating parameters. In this case, the success of the adjustment is controlled. Also, if there is a deviation between the actual operating parameters of the eccentric screw pump and the set operating parameters, especially if deviations deviating from the specified tolerance range are present, the re-activation and adjustment of the adjustment mechanism is performed. If the deviation between the actual operating parameters and the set operating parameters can be sufficiently reduced through the adjustment of the adjusting mechanism and hence the readjustment or adjustment of the stator, no further adjustment is performed. Instead, the adjusted operating condition of the eccentric screw pump is again checked via the sensor measurements described above after a defined additional time interval.

Conversely, if during the primary query of the actual operating state of the eccentric screw pump a deviation between the actual operating parameters and the set operating parameters is not detected, in particular if deviations deviating from the determined tolerance range are not detected, Subsequently, the actual operating state material of the eccentric screw pump is performed through measurement of the actual operating parameters, and a comparison of the set operating parameters and the actual operating parameters is performed. Through regular queries at defined time intervals, the stator / rotor system is continuously monitored during ongoing operation. Accordingly, deviations from a desired operating state can be realigned and adapted in real time during ongoing operation.

According to one embodiment of the present invention, the pressure, rotational speed, torque, temperature and / or volumetric flow rate of the eccentric screw pump are detected by the sensor. Alternatively, or additionally, the repulsive force of the elastomeric material of the elastomeric portion and / or pretensioning between the rotor and the stator is measured. Further, the position of at least one adjusting member of the adjusting mechanism and / or the relative separation distance between the two adjusting members of the adjusting mechanism can be detected by the sensor.

According to an embodiment of the present invention, in which the adjustment mechanism includes two adjustment members with variable spacing between them, adjustment of the adjustment mechanism is performed by enlarging or reducing the relative spacing between the two adjustment members. The variation in the spacing between the two adjusting members causes a variation in the cross-section and length of the connected elastomeric portion of the stator / rotor system. In this case, the closed-loop control mechanism calculates the set spacing between the two adjusting elements based on the physical parameters detected by the sensors of the stator / rotor system, and in particular calculates the adjusting path of the second position variable adjusting element. The adjustment mechanism is then operated and the calculated position of the second position variable adjustment member is adjusted, and in particular as a result of which the calculated spacing distance between the two adjustment members is adjusted. After an additional time interval, the physical operating parameters are again detected. If the deviation from the desired actual value is reduced, this represents the new operating state of the eccentric screw pump. With further reconditioning or adjustment, the new operating state of the eccentric screw pump can be continuously approached to the desired optimum operating state. If the deviation from the desired actual value is not reduced, further adjustment of the adjustment mechanism is performed. In other words, the present invention relates to a stator / rotor system for an eccentric screw pump and to closed-loop control of the system. The present invention particularly relates to an automatic closed loop control system for variable pretensioning between a stator and a rotor of an eccentric screw pump, that is to say, between a soft part (elastomeric part) and a relatively harder part (a stiffening member or so- . A further advantage is that the eccentric screw pump can be operated at an optimum operating point at any time, which achieves a clear increase in the energy efficiency of the stator / rotor system.

The automatic closed loop control of pretensioning leads to automatic wear compensation in particular, so that the stator can be used for a relatively long time. Through predetermined procedures during switch-on and / or off, breakaway torque can be reduced through adjustment of the stator.

In addition, pretensioning between the stator and the rotor with an automatic closed loop control system can preferably be adapted to the viscosity of the conveyed medium.

The methods herein may, alternatively or additionally, include one or more features and / or characteristics of the apparatus described above. Likewise, the apparatus of the present disclosure may alternatively or additionally include individual or plural features and / or characteristics of the described method.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention and the advantages thereof will be described in more detail in accordance with the accompanying drawings. The proportions of the sizes of the individual elements in the drawings do not always correspond to the actual size ratios because some of the shapes are simplified and the other shapes are shown enlarged relative to other elements for a relatively more clear illustration .
1 is a schematic partial view showing a known stator / rotor system (prior art);
2 is a schematic partial view showing a first embodiment of a stator / rotor system according to the present invention including an adjustment mechanism;
3 is a flow diagram schematically illustrating a closed-loop control mechanism for adjusting a stator / rotor system.
4 is a graph showing the ideal operating point along the adjustment path of the adjustment mechanism.

The same reference numerals are used for the same or functioning elements of the present invention. Also, for clarity, only those figures that are required for the description of each figure are shown in separate figures. The illustrated embodiments are merely illustrative of how the device according to the invention or the method according to the invention can be formed and do not represent a critical limitation.

In Figure 1 a schematic partial view of a known stator / rotor system 1 for an eccentric screw pump is shown. The system 1 comprises a one-row helical rotor (not shown), which is generally metallic, and a stator 3, with double-row threads. During operation of the eccentric screw pump, the rotor performs an eccentric rotational motion about its stator longitudinal axis X3 with its own axis of rotation. The stator 3 includes an elastomeric portion 4 and a stator casing 5 and there is no fixed connection between the elastomeric portion 4 and the stator casing 5. [

Figure 2 shows a schematic partial view of a first embodiment of a stator / rotor system 10 according to the invention, including an adjusting mechanism 12 for re-adjusting or adjusting the stator 3. [ The adjustment mechanism 12 includes a first fixed type adjustment member 13 and a second position variable adjustment member 14. The variation in the spacing between the two adjusting members 13 and 14 is dependent on the deformation of the elastomer and consequently the variation of the cross-section and / or length of the elastomeric portion 4 of the stator 3, (4) of the elastomeric portion (4). In particular the flange 23 on the stator casing 5 is used as a fixed type adjusting member 13 and the actuating member 24 disposed on the free end 8 of the elastomeric portion 4 is connected to the position adjustable member 14 ).

The adjustment mechanism 12 is connected to the closed loop control system 30 and is operated and controlled through this closed loop control system. The closed loop control system 30 includes an open loop controller 32 and one or more sensors 35 for measuring the physical operating parameters of the stator / rotor system 10 or the eccentric screw pump. More specifically, the at least one first sensor 36 is provided on the eccentric screw pump for measurement of pump pressure, rotational speed, temperature and / or volumetric flow rate. Further, one or more second sensors 37, for example, for detecting pre-tensioning between the rotor and the stator 3, or the repulsive force of the elastomeric material, may be disposed on the elastomeric portion 4. One or more third sensors 38 for detecting the position of the positionable adjustment member 14 or the relative spacing distance between the fixed adjustment member 13 and the positionable adjustment member 14 may be adjusted by the adjustment mechanism 12, Lt; / RTI > The data detected by the sensor is sent to the open loop controller 32, which compares the data to the set operating parameters and if there is a deviation between the measured actual operating parameters and the set operating parameters In turn activates the corresponding adjustment of the adjustment system 12 and in particular activates the adjustment in which the relative spacing between the fixed adjustment member 13 and the positionable adjustment member 14 varies, The length and / or the length of the elastomeric portion 4 of the stator 3 is caused to vary.

3, there is schematically shown the construction of a closed-loop control mechanism for adjusting the stator / rotor system 10 according to Fig. The closed-loop control mechanism according to the present invention is characterized by various physical operating parameters of the stator / rotor system 10 or of the eccentric screw pump and of the worn state of the stator 3 or of the stator 3 between the rotor 3 and the eccentric screw pump, Correlation between sharpening is established. For example, a correlation is established between physical operating parameters such as pressure, flow rate, rotational speed and / or viscosity, wear state of the stator 3 or pretensioning between the stator 3 and the rotor. The most direct parameter to combine the correlations together is the tensile state in the elastomeric material. The tension may be measured directly through a suitable sensor device 37 in the elastomeric material or may be measured directly on the end face of another part, such as the stator wall, especially the stator casing 5, or the elastomeric part 4, The closure members of the stator casing 5, the rotor of the stator / rotor system 10, and the like.

Alternatively, and / or additionally, on the eccentric screw pump, measurable parameters such as pump pressure, rotational speed at which the eccentric screw pump is operated, temperature, volumetric flow rate of the transported medium, etc. can be considered.

By means of a closed loop control algorithm according to the invention, an adjustment mechanism 12, in which the correlation is set, for example, from pressure, flow rate, rotational speed and required pre-tensioning, and is therefore adapted to adjust the optimum operating point, Lt; / RTI > is determined. In particular the sensors 38 for detecting the actual state of the adjustment system, in particular the position of the positionable adjustment member 14, or the relative spacing distance between the fixed adjustment member 13 and the positionable adjustment member 14, and / Sensors 38 may be provided that monitor the adjustment of the desired set position during adjustment of the position of the adjustment member 14. [

The operating parameters detected by the sensor provide information on the operating state of the eccentric screw pump. The operating parameters are compared with the defined operating parameters stored in the characteristic map, e.g., in the open loop controller 32, or in the diagram, via the open loop controller 32 (compare Fig. 2). If there is no deviation between the actual operating parameters and the set operating parameters, the reaction of the system is not performed. Instead, the actual operating parameters are measured and compared again after the time interval? T1 so that periodic monitoring or checking of the operating state of the eccentric screw pump or stator / rotor system 10 is performed.

On the contrary, if there is a deviation between the actual operating parameters and the set operating parameters, the open loop controller 32 determines the necessary adjustment of the adjustment mechanism 12 according to the stored characteristic map or stored plot, Activate the adjustment mechanism. After the automatic adjustment of the adjustment mechanism 12, the physical operating parameters of the eccentric screw pump or stator / rotor system 10 are again measured after the additional time interval At2, from which an optimal operating state is achieved, or Whether it is maintained or not. If the measured operating parameters do not correspond to the desired setting parameters, the adjustment path is again calculated via the open loop controller 32 and the adjustment mechanism 12 is readjusted accordingly. Particularly, an incremental adjustment via a closed loop control algorithm as described in connection with FIG. 4 below is performed.

Although the desired optimum operating conditions of the eccentric screw pump have been achieved through adjustment, in order to achieve the optimum deformation of the elastomer during the ongoing operation and consequently the optimum operating condition of the eccentric screw pump, (Δt3), a continuous monitoring through periodic detection of the operating parameters and the re-adjustment of the adjustment mechanism according to the case are carried out.

In Fig. 4, the adjustment of the ideal operating point according to the adjustment path n of the adjustment mechanism is shown. A specific volume flow rate (Q) is assigned to the specific rotational speed of the eccentric screw pump. In particular, when the volumetric efficiency is 100%, the volume flow rate Q may be a volume that is accurately transferred from the suction side to the pressure side of the eccentric screw pump corresponding to the rotational speed through the individual transfer members (transfer chambers).

Now, the optimal adjustment of the ideal operating point (iBP) of the eccentric screw pump is performed as follows. In short, observing the volume flow rate Q over a specific adjustment path n of the adjustment mechanism at a constant rotational speed condition, it is confirmed that the volume flow rate Q is almost constant over the relatively longer adjustment path n . However, the required torque (not shown in the graph of Fig. 4) is not constant. If the adjustment elements of the adjustment mechanism are adjusted accordingly and / or the pre-tensioning is extinguished by the new positioning, the torque decreases through the relatively lower friction loss due to the relatively lower pre-tensioning. In a generally large adjustment range where the variation of the volumetric flow rate Q is not at least largely carried out, the efficiency of the eccentric screw pump increases because still no backwash occurs or only minor. The efficiency of the eccentric screw pump decreases only when the back flow reaches an increasingly higher operating point. The point of highest efficiency is the ideal operating point (iBP) and can be expressed explicitly as follows. In other words, the ideal operating point (iBP) of the eccentric screw pump is precisely the same as that of the adjustment path n of the adjustment mechanism in which pre-tensioning is present between the rotor and the stator such that no backwash occurs at all, Lt; / RTI > In other words, the ideal operating point (iBP) is the point at which pretensioning is generated as necessary to produce the required backpressure without backflow of the medium directly within the rotor / stator system.

The functionality is used for a new closed loop control algorithm, and in particular an incremental approach to the ideal operating state (iBP) is performed. In accordance with one embodiment of the present invention, the closed loop control algorithm uses the following measurement principle.

1. Detection of operating parameters of the eccentric screw pump, such as pressure, rotational speed, torque (motor current), and occasional detection of volumetric flow rate (Q), under conditions where the measurement is carried out for example in a volumetric flowmeter, .

2. Adjustment of the rotor / stator system via the adjustment mechanism: the adjustment is completed at first. The rubber of the elastomeric portion is compressed so that the backwash is zero, or almost zero. Particularly as the compression increases, the volumetric flow rate Q decreases because the chamber volume of the pump chambers of the eccentric screw pump becomes smaller.

3. If a point in the region of sufficient compression is guaranteed, adjustment is resumed. In this case, the volumetric flow rate Q is kept constant until initially reaching a certain point. At this point, the volumetric flow rate Q drops because the back flow in the stator / rotor system increases. The ideal operating point (iBP) is located just before the drop point. The region of sufficient compression can be determined, for example, according to the measured values for the volumetric flow rate (Q). The volume flow Q increases when the adjustment mechanism is closed. If the volumetric flow rate is no longer fluctuating, or if the volumetric flow rate Q is slightly lower, the maximum value is exceeded.

4. The adjustment according to item 3 is carried out independently within the rotor / stator system at the determined time intervals, thereby ensuring active adjustment or adaptation to the variable operating conditions of the pump.

The present invention has been described with reference to the preferred embodiments. It will be apparent, however, to one skilled in the art, that the present invention may be modified or modified without departing from the scope of the appended claims.

1: stator / rotor system
3:
4: elastomer part
5: Stator casing
8: free end
10: Stator / rotor system
12: Adjustment mechanism
13: first fixed type adjusting member
14: second position variable member
23: Flange
24:
30: closed loop control system
32: Open Loop Controller
35: Sensor
36: first sensor
37: Second sensor
38: Third sensor
Δt: time interval
iBP: ideal operating point
n: Adjustment path
Q: Volumetric flow rate
X: vertical axis

Claims (17)

A stator / rotor system (10) comprising a stator (3) including a rotor with a rotor screw and a female threaded portion, the stator (3) comprising a strut member (5) and an elastomeric portion , Characterized in that the strut member (5) completely surrounds the elastomeric part (4) in at least part of its area,
The stator / rotor system 10 includes an adjustment mechanism 12 for adjusting the stator 3 and the adjustment mechanism is connected to the stator / rotor system 10 via the open loop controller 32, And / or at least one sensor (35) for detection of actual operating parameters of said eccentric screw pump, wherein the actuation of said adjustment mechanism (12) is dependent on the actual operating parameters detected by said one or more sensors (35) Loop controller (32), taking into account the forces exerted by the eccentric screw. The stator / rotor system (10) according to claim 1, wherein the adjustment mechanism (12) comprises two adjustment members (13, 14) arranged on the stator / rotor system (10) There is a mechanical coupling and / or connection between the adjusting members 13 and 14 of the stator 12 and the stator 3 so that by the variation of the relative spacing between the two adjusting members 13 and 14 A variation in cross-section and length of the elastomeric portion (4) of the stator can be caused. The stator / rotor system (10) according to claim 2, wherein the one first side adjustment member (13) is arranged on the stator / rotor system (10) in a fixed manner and the second side adjustment member (14) Wherein the eccentric screw pump is disposed in a position-variable manner on the eccentric screw pump. 4. An apparatus according to claim 3, characterized in that the second position-variable adjusting member (14) is arranged to move through an actuator actuated through the open-loop controller (32) for a variation in the spacing distance relative to the first fixed- An eccentric screw pump that can be repositioned. 5. The stator according to any one of the preceding claims, wherein at least one first sensor (36) is disposed on the eccentric screw pump and / or one or more second sensors (37) Wherein at least one third sensor (38) is disposed on the elastomeric portion (4) and / or at least one third sensor (38) is disposed on the adjustment mechanism (12). 6. The method of claim 5, wherein the first sensor (36) is configured to measure pressure, rotational speed, temperature, and / or volumetric flow rate of the eccentric screw pump, and / or the second sensor (37) And / or the third sensor 38 is configured to measure the position of the second positionable adjustment member 14 and / or to measure the position of the second positionable adjustment member 14, and / Or the spacing distance between the first fixed type adjusting member (13) and the second position variable adjusting member (14). A method for adapting an operating condition of an eccentric screw pump comprising a stator / rotor system (10), the stator / rotor system (10) comprising a rotor, a stator (3) Mechanism (12), wherein the stator comprises an elastomeric portion (4) and a strut member (5)
The method comprises the following method steps:
a. Sensor based detection of one or more physical actual operating parameters associated with the eccentric screw pump and / or sensor based detection of one or more physical actual operating parameters associated with the elastomeric portion (4) and / The method comprising: querying the actual operating state of the eccentric screw pump through sensor-based detection of one or more physical actual operating parameters associated therewith;
b. A method for comparing one or more actual operating parameters with known set operating parameters;
c. Causing the actuation of the adjustment mechanism (12) to adjust the stator (3) to be performed when a deviation between the measured actual operating parameters and the set operating parameters is detected; ≪ / RTI &
d. Wherein the adjustment of the new operating condition is monitored by checking one or more physical actual operating parameters. 8. The method according to claim 7, wherein calculation of an adjustment path (n) of the adjustment mechanism (12) is performed when a deviation between the measured actual operating parameters and the setting operation parameters is detected, ) Is actuated correspondingly to adjust the ideal operating point (iBP) of the stator (3), and the calculated adjustment path (n) is adjusted. 8. The method of claim 7, wherein adaptation of the operating state is performed through adjustment of an ideal operating point (iBP) by an incremental approach when a deviation between the measured actual operating parameters and the set operating parameters is detected, A method of adapting the operating state of an eccentric screw pump. 10. The method according to claim 9, wherein the adjustment mechanism (12) is moved to an at least substantially closed position by increased pre-tensioning in the stator / rotor system (10), then the adjustment mechanism (12) Wherein the eccentric screw pump is adjusted to an ideal operating point (iBP) that exhibits its highest efficiency through opening the eccentric screw pump. 11. A method according to any one of claims 7 to 10, characterized in that, following the adjustment of the adjustment mechanism (12), after a defined time interval (? T2), of the material of the actual operating parameters of the eccentric screw pump Wherein a comparison with the parameters is performed. 12. The method according to claim 11, wherein re-operation of the adjustment mechanism (12) is performed when there is a deviation between the actual operating parameters and the set operating parameters. 12. The method of claim 11, wherein when the deviation between the actual operating parameters and the set operating parameters is sufficiently reduced, the adjusted operating condition of the eccentric screw pump is checked again after a defined time interval (t3) Adaptation method of operating state of screw pump. 12. A method as claimed in any one of claims 7 to 11, characterized in that, after a defined time interval (? T1) when there is no deviation between the actual operating parameters and the set operating parameters, Wherein a comparison of the material of the operating parameters with the set operating parameters is performed. 15. A method according to any one of claims 7 to 14, characterized in that the pressure, rotational speed, temperature and / or volumetric flow rate of the eccentric screw pump is detected by the sensor and / or pretensioning between the rotor and the stator (3) Sensor and / or the reaction force of the elastomeric material of the elastomeric part 4 is detected by a sensor and / or the position of at least one of the adjustment elements 13, 14 of the adjustment mechanism 12 is , And / or the spacing distance between the two adjustment members (13, 14) of the adjustment mechanism (12) is measured by a sensor. 16. An adjustment mechanism according to any one of claims 7 to 15, wherein adjustment of the adjustment mechanism (12) is performed by enlarging or reducing a separation distance between two adjustment members (13, 14) of the adjustment mechanism (12) Wherein variation of the cross-section and length of the connected elastomeric part (4) of the stator / rotor system (10) is carried out through spaced-apart variation between the two adjustment elements (13, 14). 17. A method as claimed in any one of claims 7 to 16, wherein the detected deviation comprises an operating condition adaptation of the eccentric screw pump, which triggers the actuation of the adjusting mechanism only when the detected deviation deviates from a predetermined tolerance range Way.

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