Eccentric Screw Pump And Method For Adapting The Operating State Of An Eccentric Screw Pump

Abstract

The invention pertains to an eccentric screw pump with a stator-rotor system, which includes a rotor with a rotor screw and a stator with an internal thread. The stator has a support element and an elastomer part, wherein the support element encloses the elastomer part sectionally over its entire circumference. The stator-rotor system has a mechanism for adjusting the stator, which is coupled to at least one sensor for determining actual operating parameters of the stator-rotor system by means of a control unit that activates the adjusting mechanism with consideration of the actual operating parameters determined with the aid of at least one sensor.

1 . An eccentric screw pump with a stator-rotor system comprising a rotor with a rotor screw and a stator with an internal thread, wherein the stator comprises a support element and an elastomer part, and wherein the support element encloses the elastomer part at least sectionally over its entire circumference, characterized in that the stator-rotor system features an adjusting mechanism for adjusting the stator which is coupled to at least one sensor for determining actual operating parameters of the stator-rotor system with control unit that can activate the adjusting mechanism with consideration of the actual operating parameters determined with the aid of at least one sensor. 
     
     
         2 . The eccentric screw pump according to  claim 1 , wherein the adjusting mechanism comprises two adjusting elements that are arranged on the stator-rotor system and variable with respect to their distance from one another, wherein a mechanical coupling and/or connection exists between the adjusting elements of the adjusting mechanism and the stator such that a change in the cross section and the length of the elastomer part of the stator can be realized by changing the relative distance between the two adjusting elements. 
     
     
         3 . The eccentric screw pump according to  claim 2 , wherein the first adjusting element is arranged stationary on the stator-rotor system and the other, second adjusting element is arranged positionally variable on the stator-rotor system. 
     
     
         4 . The eccentric screw pump according to  claim 3 , wherein the positionally variable second adjusting element can be repositioned by means of an actuator that is activated by the control unit in order to change its distance from the stationary first adjusting element. 
     
     
         5 . The eccentric screw pump according to  claim 1 , wherein at least one first sensor is arranged on the eccentric screw pump and/or wherein at least one second sensor is arranged on the elastomer part of the stator and/or wherein at least one third sensor is arranged on the adjusting mechanism. 
     
     
         6 . The eccentric screw pump according to  claim 5 , wherein the first sensor is designed for measuring the pressure, rotational speed, temperature and/or volumetric flow rate of the eccentric screw pump and/or wherein the second sensor is designed for measuring the prestress and/or reaction forces of the elastomer material of the elastomer part and/or wherein the third sensor is designed for measuring the position of the positionally variable second adjusting element and/or for measuring the distance between the stationary first adjusting element and the positionally variable second adjusting element. 
     
     
         7 . A method for adapting the operating state of an eccentric screw pump with a stator-rotor system, wherein the stator-rotor system comprises a rotor, a stator and an adjusting mechanism for adjusting the stator, wherein the stator comprises an elastomer part and a support element, and wherein the method comprises the following steps:
 a. establishing an actual operating state of the eccentric screw pump by respectively determining at least one actual physical operating parameter concerning the eccentric screw pump and/or at least one actual physical operating parameter concerning the elastomer part and/or at least one actual physical operating parameter concerning the adjusting mechanism with the aid of suitable sensors;   b. comparing the at least one actual operating parameter with known nominal operating parameters;   c. activating the adjusting mechanism if the measured actual operating parameters deviate from the nominal operating parameters in order to adjust the stator,   d. wherein the adjustment of the new operating state is monitored by controlling at least one actual physical operating parameter.   
     
     
         8 . The method according to  claim 7 , wherein an adjustment travel of the adjusting mechanism is calculated if the measured actual operating parameters deviate from the nominal operating parameters, and wherein the adjusting mechanism is activated accordingly and the calculated adjustment travel is carried out in order to adjust an ideal operating point (iBP) of the stator. 
     
     
         9 . The method according to  claim 7 , wherein the adaptation of the operating state in response to a deviation between the measured actual operating parameters and the nominal operating parameters is realized by adjusting an ideal operating point (iBP) by means of an incremental approximation. 
     
     
         10 . The method according to  claim 9 , wherein the adjusting mechanism is transferred into an at least largely closed position, in which the prestress in the stator-rotor system is increased, and wherein the ideal operating point (iBP), at which the eccentric screw pump performs with maximum efficiency, is subsequently adjusted by opening the adjusting mechanism in a controlled fashion. 
     
     
         11 . The method according to  claim 7 , wherein the actual operating parameters of the eccentric screw pump are after the adjustment of the adjusting mechanism established anew and compared with the nominal operating parameters once a defined time period has elapsed. 
     
     
         12 . The method according to  claim 11 , wherein the adjusting mechanism is activated anew if the actual operating parameters deviate from the nominal operating parameters. 
     
     
         13 . The method according to  claim 11 , wherein the adjusted operating state of the eccentric screw pump is checked anew after a defined time period (Δt 3 ) if the deviation between the actual operating parameters and the nominal operating parameters was sufficiently reduced. 
     
     
         14 . The method according to  claim 7 , wherein the actual operating parameters of the eccentric screw pump are established anew and compared with the nominal operating parameters after a defined time period (Δt 1 ) if the actual operating parameters do not deviate from the nominal operating parameters. 
     
     
         15 . The method according to  claim 7 , wherein the pressure, rotational speed, temperature and/or volumetric flow rate of the eccentric screw pump and/or the prestress between the rotor and the stator and/or reaction forces of the elastomer material of the elastomer part and/or the position of at least one adjusting element of the adjusting mechanism and/or the distance between two adjusting elements of the adjusting mechanism are respectively determined with the aid of suitable sensors. 
     
     
         16 . The method according to  claim 7 , wherein the adjustment of the adjusting mechanism is realized by increasing or decreasing the distance between two adjusting elements of the adjusting mechanism, and wherein the cross section and the length of the coupled elastomer part of the stator-rotor system are changed due to the distance change between the two adjusting elements. 
     
     
         17 . The method according to  claim 7 , wherein the determined deviation only triggers an activation of the adjusting mechanism if the determined deviation lies outside a defined tolerance range.