Pig and Pig Disc for a Pig

Abstract

Pig for inspecting and/or cleaning pipelines which transport, in particular, oil, gas or water, wherein the pig has at least one flexible plastic element which is mounted on a pig element which is preferably embodied as a pig body, wherein the plastic element has, viewed from the pig element, at least one electromechanical transducer, extending in the longitudinal direction of the plastic element, for detecting and/or outputting a change in shape of the plastic element. Furthermore, the invention relates to a pig disc in the elastic side region of which there is at least one electromechanical transducer as a sensor for detecting changes in the free internal cross section of a pipeline.

Claims

1. A pig for inspecting and/or cleaning pipelines which transport, in particular, oil, gas or water, wherein the pig has at least one flexible plastic element which is mounted on a pig element which is preferably embodied as a pig body, wherein the plastic element has, viewed from the pig element, at least one electromechanical transducer, extending in the longitudinal direction of the plastic element, for detecting and/or outputting a change in shape of the plastic element.

2. The pig according to claim 1, wherein the plastic element connects the pig element to a further pig component.

3. The pig according to claim 1, wherein a multiplicity of transducers is arranged in and/or on the plastic element.

4. The pig according to claim 1, wherein the transducer is designed to generate a force transversely with respect to its longitudinal extent in order to change, in particular, a relative position of the pig element with respect to the pig component.

5. The pig according to claim 4, wherein the transducer is designed to amplify a force which can be applied to an inner wall of the pipeline by the pig.

6. The pig according to claim 1, wherein the transducer is embodied as a sensor.

7. The pig according to claim 1, wherein the plastic element is elastic, and the transducer is of flexible design such that it can correspondingly execute changes in the shape of the plastic element.

8. The pig according to claim 1, wherein the transducer has a dielectric which is enclosed by electrodes.

9. The pig according to claim 8, wherein the dielectric comprises an elastomer, in particular a polyurethane.

10. The pig according to claim 8, wherein the transducer is enclosed by a body made of polyurethane.

11. The pig according to claim 1, wherein the plastic element is predominantly embodied from polyurethane.

12. The pig according to claim 1, wherein a layer of the transducer is embodied at least partially on the basis of a soot-containing and/or barium-titanate-containing elastomer.

13. The pig according to claim 8, wherein an electrode of the transducer is embodied at least partly on the basis of a carbon nanotube-containing, graphite-containing, soot-containing or metal-powder-containing material.

14. The pig according to claim 1, wherein the transducer can be twisted in such a way that it is flexible in the axial direction and in the circumferential direction.

15. A pig disc for a pig which can be used in a pipeline and for detecting changes in the free internal cross section of the pipeline, comprising a disc body with an inner attachment region for securing the pig disc to a pig body and an external region which adjoins the attachment region further toward the outside with respect to a central axis and which can enter at least partially into contact with an inner side of the pipeline, wherein at least the elastic external region has at least one electromechanical transducer as a sensor for detecting the changes.

16. The pig disc according to claim 15, wherein the sensor is of flexible design such that it can correspondingly execute changes in the shape of the pig disc caused by the changes.

17. The pig disc according to claim 15, wherein the disc body has, viewed in the axial direction, at least two sensors which are spaced apart from one another.

18. The pig disc according to claim 15, wherein the disc body has, in the circumferential direction, a multiplicity of segments which are separated from one another.

19. The pig disc according to claim 18, wherein the disc body has at least one sensor per segment.

20. The pig disc according to claim 15, wherein the disc body has, in the radial direction, a multiplicity of sensors which are arranged at least partially one behind the other.

21. The pig disc according to claim 15, wherein the sensor has a dielectric which is enclosed by electrodes.

22. The pig disc according to claim 21, wherein the dielectric comprises an elastomer, in particular a polyurethane.

23. The pig disc according to claim 15, wherein the sensor is enclosed by a disc body made of polyurethane.

24. The pig disc according to claim 21, wherein the dielectric of the sensor has conductive or highly polarizing organic or inorganic filler materials, in particular barium titanate.

25. The pig disc according to claim 15, wherein an electrode of the sensor is embodied at least partially from at least one layer of a soot-containing elastomer.

26. The pig disc according to claim 15, wherein an electrode of the sensor is embodied at least partially from at least one layer of a carbon nanotube-containing, graphite-containing or metal-powder-containing material.

27. The pig disc according to claim 15, wherein the sensor can be twisted in such a way that it is flexible in the axial direction and in the circumferential direction.

28. The pig disc according to claim 15, comprising an edge protection.

29. The pig for detecting changes in the free internal cross section of a pipeline, comprising a pig disc according to claim 15.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Further advantages and details of the invention can be found in the following description of exemplary embodiments. The schematic illustrations in the figures are as follows:

[0047] FIG. 1 shows a subject matter according to the invention in a plan view,

[0048] FIG. 2 shows a view of a detail of a subject matter according to the invention according to FIG. 1,

[0049] FIG. 3 shows a further subject matter according to the invention,

[0050] FIG. 4 shows the subject matter according to FIG. 3 in a partial view in a pipeline,

[0051] FIG. 5 shows a further subject matter according to the invention in a front view, and

[0052] FIG. 6 shows the subject matter according to FIG. 5 in a partial side view.

DETAILED DESCRIPTION

[0053] Individual technical features of the exemplary embodiments described below can also be combined with exemplary embodiments described above and the features of the independent claims as well as any further claims to form subjects according to the invention. Where appropriate, identically functioning elements are provided with identical reference symbols.

[0054] A pig disc according to the invention is provided according to FIG. 1 with a disc body 1 which has an inner attachment region 2 with a central recess 3. Starting from a central axis 4 which protrudes perpendicularly from the plane of the drawing in FIG. 1 and can be seen, for example, in FIG. 4, there is further toward the outside an adjoining external region 5 which comprises a multiplicity of segments 6 (cf. FIG. 4).

[0055] In the exemplary embodiment according to FIG. 1, segments 6 which are similar to pieces of cake are present in the circumferential direction 16. Each segment 6 has two sensors 7 and 8 which are arranged one behind the other in the axial direction and which are enclosed by the polyurethane 9 of the external region 7. Both the sensor 7 and the sensor 8 comprise flexible electrodes 11 which enclose a dielectric 12 based on a polyurethane. In the case of a structural irregularity, the pig disc is deformed, as can be seen in the upper right-hand part of FIG. 2. As a result, the sensor 7 which is at the front in the direction of travel F (cf. FIG. 4) experiences extension which leads to an increase in its capacitance, while the rear sensor which is located in the direction of travel F experiences compression and an associated reduction in its capacitance. Correspondingly the capacitance C.sub.7>C.sub.7, and the capacitance C.sub.8<C.sub.8. The axial direction corresponds to, or is opposed to, the direction of travel F.

[0056] As a result of the measurement of the differences between the capacitances of the two sensors 7 and 8 it is possible to obtain a change value which is influenced by the temperature and is proportional to the change in shape. The latter can be calculated analytically to form a change in shape of the electrodes and correspondingly provide information about the deformation of the pig disc. Said change value can also alternatively be approximated by means of a database comparison and empirical values of a deformation of the pig disc which are stored in the database and in this respect also provide information about the deformation thereof.

[0057] A pig 20 according to the invention, provided with two pig discs which are equipped as gauging plates, can be found in FIG. 3. In said figure, pig discs 14 which are attached to a pig body 13 and which correspond to the pig discs described above are attached. The detection of the changes in capacitance is carried out within the at least in parts hollow pig body. Additionally or alternatively, parts of the electronics could at least partially also be arranged in the pig disc. Within the pig body there are also units for detecting the changes in capacitance of the sensors and associated memory units. The sensors are correspondingly connected via cable 10 to the measuring unit or detection unit. The stored values can then be fed to an evaluation unit after the run via corresponding interfaces or already partially or completely initially or finally evaluated in a corresponding evaluation unit within the pig body. The location of structural irregularities 16 on an inner side 17 of a pipeline 15 (cf. FIG. 4) can be determined by means of associated further sensors which detect the position of the pig in the x-y plane and in the z direction, that is to say in the axial direction along the longitudinal axis 4. Correspondingly, subsequent cleaning runs and inspection runs of pigs can be carried out in a more targeted fashion.

[0058] A further subject matter according to the invention according to FIGS. 5 and 6 has a multiplicity of elastic plastic elements 26 which produce a connection between a pig body 13 and further pig parts 27 in the form of sensing caps. Each plastic element 26 has on the inside two electromechanical transducers 7 and 8 which supply information about the curvature of the plastic element 26 and which can be evaluated by an associated evaluation electronics system.