Eccentric Screw Pump And Use Of An Eccentric Screw Pump

Abstract

An eccentric screw pump for delivering fluid and/or granular media. The pump body of the eccentric screw pump includes an inlet region, a pump unit and an outlet region. A drive unit is assigned to the inlet region. The pump unit includes a rotor and a stator, wherein the rotor moves eccentrically in the stator. The inlet region constitutes the suction side and the outlet region constitutes the pressure side of the eccentric screw pump. A bypass connection with at least one safety valve is assigned to the eccentric screw pump in order to take up and return back-flowing medium between the pressure side and the suction side of the eccentric screw pump. The bypass connection and the safety valve may also be integrated into the pump body of the eccentric screw pump.

1 . An eccentric screw pump or delivering fluid and/or granular media with a pump body the pump body comprising an inlet region, a pump unit and an outlet region, wherein the pump unit is constituted by a rotor and a stator and wherein the rotor can be moved eccentrically in the stator, wherein the inlet region constitutes the suction side and the outlet region constitutes the pressure side of the eccentric screw pump and wherein a bypass connection with at least one safety valve is assigned to the eccentric screw pump in order to take up and return back-flowing medium between the pressure side and the suction side of the eccentric screw pump wherein the bypass connection and the safety valve are integrated into the pump body of the eccentric screw pump. 
     
     
         2 . The eccentric screw pump according to  claim 1 , wherein the bypass connection and the safety valve are integrated in the region of the pump unit into the pump body of the eccentric screw pump. 
     
     
         3 . The eccentric screw pump according to  claim 1 , wherein the stator is disposed in a casing tube and wherein an intermediate space is formed between the stator and the casing tube, which intermediate space is in fluidic connection with the respective internal spaces of the inlet region and the outlet region and constitutes the bypass connection. 
     
     
         4 . The eccentric screw pump according to  claim 1 , wherein the stator is disposed in a stator sleeve and wherein the stator sleeve lies with its inner circumference extensively over its surface area against the outer circumference of the stator and wherein at least one connection line parallel to the longitudinal axis of the eccentric screw pump is constituted between the stator and the stator sleeve, which connection line is in fluidic connection via first and second connections with the respective internal spaces of the inlet region and the outlet region and constitutes the bypass connection. 
     
     
         5 . The eccentric screw pump according to  claim 4 , wherein the at least one connection line is constituted in particular by a continuous recess in the external lateral surface of the stator parallel to the longitudinal axis of the eccentric screw pump, wherein the recess extends along a length of the stator, in particular along the entire length of the stator. 
     
     
         6 . The eccentric screw pump according to  claim 1 , wherein the rotor comprises a hollow space along its rotor longitudinal axis, which hollow space is in fluidic connection with respective internal spaces of the inlet region and outlet region and constitutes the bypass connection. 
     
     
         7 . The eccentric screw pump according to  claim 1 , wherein the stator comprises at least one return flow channel, which is constituted parallel to the longitudinal axis of the eccentric screw pump along the stator length, wherein the at least one return flow channel is in fluidic connection with the respective internal spaces of the inlet region and the outlet region and constitutes the bypass connection. 
     
     
         8 . The eccentric screw pump according to  claim 7 , wherein the return flow channel is constituted in a region between an inner thread pitch of the stator and the external lateral surface of the stator and wherein the return flow channel does not comprise any open connection to the inner thread pitch of the stator and/or to the external lateral surface of the stator. 
     
     
         9 . The eccentric screw pump according to  claim 7 , wherein the at least one return flow channel is cast in the stator. 
     
     
         10 . The eccentric screw pump according to  claim 7 , wherein the safety valve is disposed inside the return flow channel, in particular wherein the safety valve is disposed in a region between the inlet region and the pump unit. 
     
     
         11 . The eccentric screw pump according to  claim 7 , wherein the safety valve is integrated into the outlet region of the pump body and wherein an outlet opening of the safety valve emerges into the return flow channel via a first connection. 
     
     
         12 . The eccentric screw pump according to  claim 1 , wherein the safety valve is an overflow valve. 
     
     
         13 . A method of delivering fluid and/or granular media comprising the steps of:
 moving a rotor of a pump unit of a pump body of an eccentric screw pump eccentrically in a stator of the pump unit;   introducing a fluid and/or a granular media to an inlet region of the pump body, said inlet region constituting suction side;   pumping the fluid from the inlet region to an outlet region of the pump body, said outlet region constituting a pressure side;   taking of and returning an back-flowing medium from the pressure side to the suction side via a bypass connection with at least one safety valve;   said bypass connection and safety valve being integrated into the pump body.   
     
     
         14 . The method of delivering fluid and/or granular media of  claim 13 , said step of taking up and returning further comprising the step of moving the back-flowing medium from the pressure side to the suction side though a region of the pump body around the pump unit of the eccentric screw pump. 
     
     
         15 . The method of delivering fluid and/or granular media of  claim 13 , said step of taking up and returning further comprising the step of moving the back-flowing medium through an intermediate space between the stator and a casing tube, said stator being disposed in the casing tube. 
     
     
         16 . The method of delivering fluid and/or granular media of  claim 13 , said step of taking up and returning further comprising the step of moving the back-flowing medium in a direction parallel to the longitudinal axis of the eccentric screw pump through an intermediate space between the stator and a stator sleeve, said stator sleeve disposed with its inner circumference extensively over its surface area against the outer circumference of the stator and forming the intermediate space. 
     
     
         17 . The method of delivering fluid and/or granular media of  claim 13 , said step of taking up and returning further comprising the step of moving the back-flowing medium through a hollow portion of the rotor disposed along its rotor longitudinal axis. 
     
     
         18 . The method of delivering fluid and/or granular media of  claim 13 , said step of taking up and returning further comprising the step of moving the back-flowing medium through at least one return flow channel in the stator disposed parallel to the longitudinal axis of the eccentric screw pump along the stator length. 
     
     
         19 . The method of delivering fluid and/or granular media of  claim 18 , said step of taking up and returning further comprising the step of moving the back-flowing medium through said at least one return flow channel in a region between an inner thread pitch of the stator and the external lateral surface of the stator and without an open connection to the inner thread pitch of the stator and/or to the external lateral surface of the stator. 
     
     
         20 . The method of delivering fluid and/or granular media of  claim 18 , said step of taking up and returning further comprising the step of moving the back-flowing medium from the pressure side to the suction side through said safety valve before the back-flowing medium reaches the inlet region.