EP2532833B1 - Conveying element for an eccentric screw pump and eccentric screw pump - Google Patents

Description

The invention relates to a conveying element for an eccentric screw pump. The conveying element is for example a stator or a rotor of the eccentric screw pump. Furthermore, the invention relates to an eccentric screw pump and a method for producing a conveyor element for an eccentric screw pump.

The technical field of the invention relates to the metering of viscous media, such as fluids or liquids, such as adhesives or sealants, paints, varnishes, solvents, suspensions, viscous raw materials, emulsions, pastes, food pastes, oils or fats.

In many industrial processes, but also in commerce and industry, such viscous media are conveyed and metered via progressing cavity pumps.

In the promotion and metering of viscous media, especially high-viscosity media, conventionally a high pressure level for the feed of the eccentric screw pump is usually necessary. This is achieved for example by pre-pressure pumps, pressure vessel systems, pressure accumulator or pressure and volume storage.

In start mode or in start-up mode, however, sometimes high pressure drops can occur. In addition, conventionally, a complex pressure control is necessary.

The DE 20 2009 002 823 U1 shows an eccentric screw pump for conveying viscous, highly viscous and abrasive media. In its longitudinal direction, the eccentric screw pump has at least one conical, helically wound, at least catchy red with a slope, with at least one eccentricity and at least one Cross-section which is rotatably arranged in a single or multi-start conical stator.

The EP2063125A1 , which is considered to be the closest prior art, discloses an eccentric screw pump having the features of the preamble of claim 1.

Accordingly, it is an object of the present invention to provide improved delivery of fluids through an eccentric screw pump.

The stated object is achieved by a conveyor element for an eccentric screw pump with the features of claim 1, by a progressive cavity pump having the features of claim 14 and by a method for producing a conveyor element for an eccentric screw pump having the features of claim 15.

Accordingly, a conveyor element for an eccentric screw pump for conveying a fluid is proposed, which has a first screw thread for providing a first delivery volume and a second screw thread for providing a second delivery volume, wherein the first delivery volume is greater than the second delivery volume.

Furthermore, an eccentric screw pump for conveying a fluid is proposed, which has a stator with N + 1 threads and an arranged in the stator rotor with N threads. The stator has a first female screw thread for providing a first delivery volume and a second female screw thread for providing a second delivery volume. The rotor has a first male screw thread for providing the first delivery volume and a second male screw thread for providing the second delivery volume. The first delivery volume is greater than the second delivery volume.

Further, the first inner screw thread and the second inner screw thread are formed as a one-piece part, and the first outer screw thread and the second outer screw thread are also formed as an integral part.

Furthermore, the first inner screw thread and the second inner screw thread are made of different materials, and that first outer screw thread and the second outer screw thread are also made of different materials.

The rotor and the stator can be brought into an operative connection for conveying the fluid out of a container. The eccentric screw pump is based in particular on the Moineau principle.

Furthermore, a method for producing a conveyor element for an eccentric screw pump for conveying a fluid is proposed, in which a first screw thread for providing a first delivery volume and a second screw thread for providing a second delivery volume are prepared such that the first delivery volume is greater than the second delivery volume is.

Furthermore, a container removal system with a container for receiving the fluid to be delivered and an eccentric screw pump as described above for removing the fluid to be delivered is proposed. The container removal system can be used, for example, for barrel removal or as a degassing system with vacuum technology.

In the present conveying element, the first screw thread can act as a booster for the second screw thread. Thus, the conveying element, in particular the second screw thread of the conveying element, supplied with sufficient material and form, so that cavitation states can occur in any portion of the dosing process. As a result, a very stable dosing process is provided according to the invention. Furthermore, the accuracy of the dosage is increased since parameter deviations at start and stop of the dosing process are reduced or avoided. Furthermore, feed systems can be simplified and the pressure level can be reduced by the conveyor element according to the invention. Next, the regulatory burden can be minimized or completely eliminated.

The conveying element according to the invention ensures high efficiency, in particular high metering stability, even under poor feed conditions.

Advantageous embodiments and developments of the invention will become apparent from the dependent claims and the description with reference to the drawings.

In one embodiment, the first delivery volume is 1.3 to 4 times greater than the second delivery volume. Preferably, the first delivery volume is 1.5 times to 3 times greater than the second delivery volume.

In a further embodiment, the conveying element as a catchy or mehrgängiger rotor of

Formed eccentric screw, wherein the first screw thread and the second screw thread are each formed as an external screw thread.

In a further embodiment, the conveying element is designed as a stator of the eccentric screw pump, wherein the first screw thread and the second screw thread are each formed as a multi-course internal screw thread.

In another embodiment, the eccentricities of the first and second screw threads are the same and the diameters of the first and second screw threads are different.

In a further embodiment, the ratio between the diameter of the first screw thread and the diameter of the second screw thread is in a range between 1.3 and 4, preferably between 1.5 and 3.

In another embodiment, the eccentricities of the first and second screw threads are the same and the pitches of the first and second screw threads are different.

In another embodiment, the ratio between the pitch of the first screw thread and the pitch of the second screw thread is in a range of 1.3 to 4, preferably 1.5 to 3.

In another embodiment, the eccentricities of the first and second screw threads are the same, the diameters of the first and second screw threads differ, and the pitches of the first and second screw threads are different.

ist, wobei d1 den Durchmesser des ersten Schraubengewindes, d2 den Durchmesser des zweiten Schraubengewindes, s1 die Steigung des ersten Schraubengewindes und s2 die Steigung des zweiten Schraubengewindes bezeichnen, wobei α in einem Bereich zwischen 1,3 bis 4, bevorzugt zwischen 1,5 bis 3, liegt.In a further embodiment $\frac{d1\cdot s1}{d2\cdot s2}>\alpha$

where d1 is the diameter of the first screw thread, d2 is the diameter of the second screw thread, s1 is the pitch of the first screw thread, and s2 is the pitch of the second screw thread, α being in a range of 1.3 to 4, preferably 1.5 to 3, lies.

In another embodiment, the first screw thread is Teflon and the second screw thread is an elastomer.

For example, the fluid or viscous medium has a viscosity of 0.1 to 10 ⁷ mPas, preferably from 10 ¹ to 10 ⁶ mPas, particularly preferably from 10 ³ to 10 ⁴ mPas.

Fig. 1

eine Ansicht eines Ausführungsbeispiels eines erfindungsgemäßen eingängigen Rotors;

Fig. 2

eine Ansicht eines Ausführungsbeispiels eines erfindungsgemäßen zweigängigen Stators;

Fig. 3

eine Ansicht eines Ausschnitts eines Ausführungsbeispiels einer erfindungsgemäßen Exzenterschneckenpumpe mit einem eingängigen Rotor nach Fig. 1 und mit einem zweigängigen Stator nach Fig. 2;

Fig. 4

eine Ansicht eines Ausführungsbeispiels eines erfindungsgemäßen zweigängigen Rotors;

Fig. 5

eine Ansicht eines Ausführungsbeispiels eines erfindungsgemäßen dreigängigen Stators;

Fig. 6

eine Ansicht eines Ausschnitts eines Ausführungsbeispiels einer erfindungsgemäßen Exzenterschneckenpumpe mit einem zweigängigen Rotor nach Fig. 4 und mit einem dreigängigen Stator nach Fig. 5; und

Fig. 7

ein schematisches Ablaufdiagramm eines Ausführungsbeispiels eines Verfahrens zum Herstellen eines Förderelements für eine Exzenterschneckenpumpe gemäß der Erfindung.

The invention will be explained in more detail with reference to the exemplary embodiments indicated in the schematic figures. Show it:

Fig. 1

a view of an embodiment of a catchy rotor according to the invention;

Fig. 2

a view of an embodiment of a double-flighted stator according to the invention;

Fig. 3

a view of a section of an embodiment of an eccentric screw according to the invention with a catchy rotor according to the invention Fig. 1 and with a two-speed stator behind Fig. 2 ;

Fig. 4

a view of an embodiment of a two-speed rotor according to the invention;

Fig. 5

a view of an embodiment of a three-speed stator according to the invention;

Fig. 6

a view of a section of an embodiment of an eccentric screw according to the invention with a two-speed rotor after Fig. 4 and with a three-speed stator after Fig. 5 ; and

Fig. 7

a schematic flow diagram of an embodiment of a method for producing a conveyor element for an eccentric screw pump according to the invention.

In all figures, the same or functionally identical means and devices - unless otherwise indicated - provided with the same reference numerals.

In Fig. 1 a view of an embodiment of a catchy rotor 1 according to the invention is shown.

The catchy rotor 1 is adapted to be in operative connection with a double-flighted stator Progressing cavity pump To dose and convey fluid (see Fig. 3 ).

In a first region B1, the rotor 1 has a first screw thread 2 for providing a first delivery volume v1. In a second region B2 adjoining the first region B1, the rotor 1 has a second screw thread 3 for providing a second delivery volume v2. The first delivery volume v1 is greater than the second delivery volume v2. For example, the first delivery volume v1 is 1.3 to 4 times greater than the second delivery volume v2. In particular, the first delivery volume v1 is 1.5 times to 3 times greater than the second delivery volume v2. The first screw thread 2 and the second screw thread 3 are each formed as an external screw thread.

The first screw thread 2 and the second screw thread 3 are formed as an integral part. However, it is also possible to produce the first screw thread 2 and the second screw thread 3 as two separate parts and to add in a subsequent joining process. In the embodiment of the Fig. 1 the eccentricities e1, e2 of the first and second screw threads 2, 3 are the same. Further, the diameters d1, d2 of the first and second screw threads 2, 3 are different. The slopes s1, s2 of the first and second screw threads 2, 3 are different. For example: e1 = e2, d1 = 1.5 * d2, s1 = 1.5 * s2, v1 = 2.25 * v2 (v = 4 * e * d * s).

Fig. 2 shows a sectional view of an embodiment of a double-flighted stator according to the invention 4. The double-flighted stator 4 may be connected to the rotor 1 of Fig. 1 be brought into an operative connection (see Fig. 3 ). The double-flighted stator 4 of the Fig. 2 has in a first area B1 a first screw thread 5 for providing the first delivery volume v1. In a second region B2, the stator 4 has a second screw thread 6 for providing the second Delivery volume v2. The first screw thread 5 and the second screw thread 6 are each formed as a double-threaded thread.

Next shows the Fig. 3 a view of a section of an embodiment of an eccentric screw pump 7 according to the invention with a catchy rotor 1 after Fig. 1 and a double-flighted stator 4 Fig. 2 , The double-flighted stator 4 is shown cut. In the first region B1 of the eccentric screw pump 7, the first outer screw thread 2 of the rotor 1 and the first inner screw thread 5 of the stator 4 are arranged. Accordingly, the second outer screw thread 3 of the rotor 1 and the second inner screw thread 6 of the stator 4 are arranged in the second region B2.

In Fig. 4 is a view of an embodiment of a double-flighted rotor 1 according to the invention shown.

The double-flighted rotor 1 is suitable for metering and delivering fluid in operative connection with a three-speed stator of an eccentric screw pump (see Fig. 6 ).

In a first region B1, the rotor 1 has a first screw thread 2 for providing a first delivery volume v1. In a second region B2 adjoining the first region B1, the rotor 1 has a second screw thread 3 for providing a second delivery volume v2. The first delivery volume v1 is greater than the second delivery volume v2. For example, the first delivery volume v1 is 1.3 to 4 times greater than the second delivery volume v2. In particular, the first delivery volume v1 is 1.5 times to 3 times greater than the second delivery volume v2. The first screw thread 2 and the second screw thread 3 are each formed as an external screw thread.

The first screw thread 2 and the second screw thread 3 are in particular formed as a one-piece part. However, it is also possible to manufacture the first screw thread 2 and the second screw thread 3 as two separate parts and to add them in a subsequent joining process. In the embodiment of the Fig. 4 the eccentricities e1, e2 of the first and second screw threads 2, 3 are the same. Further, the diameters d1, d2 of the first and second screw threads 2, 3 are different. The slopes s1, s2 of the first and second screw threads 2, 3 are different.

Fig. 5 shows a sectional view of an embodiment of a three-speed stator according to the invention 4. The three-speed stator 4 may be connected to the rotor 1 of Fig. 4 be brought into an operative connection (see Fig. 6 ). The three-speed stator 4 of FIG. 5 has in the first area B1 a first screw thread 5 for providing the first delivery volume v1. In the second region B2, the stator 4 has a second screw thread 6 for providing the second delivery volume v2. The first screw thread 5 and the second screw thread 6 are each formed as a three-start internal screw thread.

Next shows the Fig. 6 a view of a section of an embodiment of an eccentric screw pump 7 according to the invention with a two-speed rotor 1 after Fig. 4 and a three-speed stator 4 after Fig. 5 , In the first region B1 of the eccentric screw pump 7, the first outer screw thread 2 of the rotor 1 and the first inner screw thread 5 of the stator 4 are arranged. Accordingly, the second outer screw thread of the rotor 1 and the second inner screw thread 6 of the stator 4 are arranged in the second region B2.

In Fig. 7 is a schematic flow diagram of an embodiment of a method for producing a conveyor element for an eccentric screw pump shown.

In a step S1, a first screw thread for providing a first delivery volume is produced in a first region of the delivery element.

In a step S2, a second screw thread for providing a second delivery volume is produced in a second region of the delivery element, wherein the first delivery volume is greater than the second delivery volume.

Although the present invention has been described above with reference to the preferred embodiments, it is not limited thereto, but modified in many ways.

LIST OF REFERENCE NUMBERS

1

rotor

2

first screw thread

3

second screw thread

4

stator

5

first screw thread

6

second screw thread

7

Cavity Pump

B1

first area

B2

second area

S1

step

S2

step

Claims (9)

1. An eccentric spiral pump (7) for conveying a fluid, comprising:

   a stator (4) with N + 1 thread pitches, the stator (4) having a first inner thread (5) for providing a first conveyance volume (v1) and a second inner thread (6) for providing a second conveyance volume (v2), the second inner thread (6) being connected to the first inner thread (5) in a longitudinal direction,

   a rotor (1) having N thread pitches arranged in the stator (4), the rotor (1) having a first outer thread (2) for providing the first conveyance volume (v1) and a second outer thread (3) for providing the second conveyance volume (v2), the second outer thread (3) being connected to the first outer thread (2) in a longitudinal direction,

   wherein the first inner thread (5) and the second inner thread (6) are integrally formed,

   wherein the first outer thread (2) and the second outer thread (3) are integrally formed,

   characterized in

   that the first conveyance volume (v1) is larger than the second conveyance volume (v2), that the first inner thread (5) and the second inner thread (6) are made of different materials, and that the first outer thread (2) and the second outer thread (3) are made of different materials.
2. The eccentric spiral pump of claim 1,
   characterized in
   that the first conveyance volume (v1) is larger than the second conveyance volume (v2) by a factor of 1.3 to 4, preferably 1.5 to 3.
3. The eccentric spiral pump of claim 1 or 2,
   characterized in
   that the eccentricities of the first and second outer and inner threads (2, 5; 3, 6) are equal and the diameters of the first and second outer and inner threads (2, 5; 3, 6) are different.
4. The eccentric spiral pump of claim 3,
   characterized in
   that the ratio of the diameter of the first outer and inner threads (2, 5) to the diameter of the second outer and inner threads (3, 6) is in a range of 1.3 to 4, preferably 1.5 to 3.
5. The eccentric spiral pump of claim 1 or 2,
   characterized in
   that the eccentricities of the first and second outer and inner threads (2, 5; 3, 6) are equal and the pitches of the first and second outer and inner threads (2, 5; 3, 6) are different.
6. The eccentric spiral pump of claim 5,
   characterized in
   that the ratio of the pitch of the first outer and inner threads (2, 5) to the pitch of the second outer and inner threads (3, 6) is in a range of 1.3 to 4, preferably 1,5 to 3.
7. The eccentric spiral pump of any of claims 1 - 6,
   characterized in
   that the eccentricities of the first and second outer and inner threads (2, 5; 3, 6) are equal, the diameters of the first and second outer and inner threads (2, 5; 3, 6) are different, and the pitches of the first and second outer and inner threads (2, 5; 3, 6) are different
8. The eccentric spiral pump of any of claims 1 - 7,
   characterized in
   that $\frac{d1\cdot s1}{d2\cdot s2}>\alpha ,$

   

   wherein
   d1 indicates the diameter of the first outer thread (2), d2 indicates the diameter of the second thread (3, 6), s1 indicates the pitch of the first thread (2, 5), and s2 indicates the pitch of the second thread (3, 6), wherein α is in a range of 1.3 to 4, preferably 1.5 to 3.
9. The eccentric spiral pump of claim 1,
   characterized in
   that the first inner thread (5) is made of Teflon and the second inner thread (6) is made of an elastomer.

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