Device for travelling within a pipeline

Abstract

The present invention relates to a device, in particular an inspection or cleaning pig, for travelling within a pipeline, the device comprising: a central element; at least one centring device, in particular arranged on the central element, for supporting the device against an inner wall of the pipeline, the centring device, as viewed in the direction of a longitudinal central axis of the central element, forming a surface extending around the longitudinal central axis in the radial direction, in particular outwardly from the central element; and at least one vibration generator for generating vibrations of the centring device.

Description

[0001] Device for locomotion in a pipeline

[0002] The invention relates to a device, in particular an inspection or cleaning pig, for movement in a pipeline.

[0003] Devices of the type mentioned above are regularly used for the inspection and / or cleaning of pipelines. For controlled movement of the device, it is necessary that the device be guided by a centering device on the inner wall of the pipeline. However, during movement, friction between the centering device and the inner pipe wall must be overcome. If the device slides along the inner pipe wall during movement, static friction must be overcome at the beginning of the movement, and sliding friction must be overcome during movement. This can lead to a stick-slip effect, for example, due to greater static than sliding friction. This stick-slip effect is undesirable, as it can lead to increased wear and material fatigue.Furthermore, the stick-slip effect can lead to irregularly high accelerations and speeds, as well as adverse vibration behavior of the device. In a device with a measuring unit, as is regularly the case with inspection devices, this impairs both the measurement itself and the quality of the measurement data. Additionally, the friction between the centering device and the pipeline can cause the device to become stuck, for example, in curved sections of the pipeline. The present invention therefore aims to create a device whose ability to move within a pipeline is improved. In particular, it should also enable improved measurement data acquisition.

[0004] According to the invention, this problem is solved by a device having the features of claim 1. Further advantageous embodiments of the invention can be found in the respective dependent claims and the following description.

[0005] The device according to the invention, in particular an inspection or cleaning pig, for movement in a pipeline comprises a central body and at least one centering device, in particular arranged on the central body, for supporting the device against an inner wall of the pipeline. Viewed in the direction of a longitudinal central axis of the central body, the centering device forms a surface extending radially around the longitudinal central axis, in particular away from the central body. The device also comprises at least one vibration generator for generating vibrations of the centering device.

[0006] When the device is arranged in the pipeline, the longitudinal axis of the central body coincides, at least substantially, with a longitudinal axis of the pipeline and, in particular, with a direction of movement of the device. The central body is specifically designed to be elongated along the longitudinal axis of the pipeline. A centering device, which, viewed in the direction of the longitudinal axis of the central body, forms a surface extending radially around the longitudinal axis, particularly away from the central body, can create a pressure difference between a section of the pipeline located upstream of the centering device and a section of the pipeline located downstream of the centering device. This pressure difference can at least partially drive the device. The design of the centering device thus facilitates the movement of the device.The centering device preferably extends radially away from the longitudinal center axis. Furthermore, the centering device is supported, in particular, entirely against the inner wall of the pipeline. This ensures that the area of ​​the centering device projected onto a plane perpendicular to the longitudinal center axis, and thus the driving force acting on the device when a fluid flows over this area within the pipeline, is sufficiently large. In particular, the area projected onto a plane perpendicular to the longitudinal center axis, at least substantially (i.e., including any tolerances necessary to allow movement of the device within the pipeline), has the shape, with respect to its circumference, of a circular cross-section of an interior space within the pipeline. The area can be closed or provided with a central recess.The centering device can be composed of several centering elements, arranged in a fan-like pattern. This allows the size of the area exposed to the flow of fluid within the centering device to be varied. The device can therefore be used, for example, with different fluid flow rates in the pipeline.

[0007] The vibration generator is connected to the centering device, particularly in a vibration-transmitting manner. Prior tests have shown that vibrations of the centering device reduce friction, especially both static and kinetic friction, between the centering device and the inner pipe wall, thereby facilitating the movement of the device. Furthermore, the static-kinetic effect is at least reduced or even eliminated, thus improving the running behavior of the device and any measurement data acquisition in devices with measuring instruments. A device that has become stuck in the pipe can also be set in motion again by reducing static friction.In existing devices, a vibration generator for generating vibrations of the centering direction can be easily retrofitted by, for example, arranging it on or in an existing centering device or central body, since no further modification of the device is required beyond the retrofit.

[0008] In an advantageous embodiment of the invention, the surface formed by the centering device is at least substantially closed. An at least substantially closed surface means a surface closed except for any recesses specifically provided, for example, for the optionally controllable fluid flow through the device. In particular, the at least substantially closed surface is a surface that is at least 50% closed when projected onto a plane perpendicular to the longitudinal central axis. If the centering device extends radially away from the central body, the at least substantially closed surface can be interrupted by the central body. The central body then forms the at least substantially closed surface. The centering device, in combination with the central body, then forms an at least substantially closed surface.This improves the propulsion of the device when fluid flows through the pipeline, and thus the movement of the device.

[0009] Preferably, the device has two centering devices arranged one behind the other in a direction of movement of the device, in particular wherein each centering device is assigned its own vibration generator. The guidance and running behavior of the device in the pipeline are thereby improved, especially when each centering device is assigned its own vibration generator. In particular, the two centering devices are arranged at two ends of the central body that point away from each other, viewed in the direction of the longitudinal center axis of the central body.Thus, viewed along the longitudinal center axis between the two centering devices, a space is created, in particular shielded by the centering devices, which serves to accommodate parts of the device, such as a vibration generator, a control unit, an energy storage device, a measuring device and / or similar components, especially on or in the central body. Preferably, the centering device is designed in the shape of a disc or collar.

[0010] A disc-shaped centering device is understood to be a flat centering device, comprising at least a substantial, i.e., also approximately fan-shaped, structure with several centering elements, arranged in a plane perpendicular to the longitudinal center axis of the device. A disc-shaped centering device allows for a particularly simple support of the device on the inner wall of the pipe in the radial direction. Both disc-shaped and collar-shaped centering devices can have a central recess for attachment to or around a central body.A collar-shaped centering device is understood to be a centering device that is formed as a surface transversely, but not necessarily perpendicularly, to the longitudinal center axis, and which, when viewed in a direction perpendicular to the longitudinal center axis, is inclined at least on one side lying in the direction of the longitudinal center axis, in particular on the side pointing in the direction of travel, and / or has a section on the inner pipe wall side running parallel to the longitudinal center axis. In the case of a centering device that, when viewed in a direction perpendicular to the longitudinal center axis, is inclined on at least one side lying in the direction of the longitudinal center axis, the inclination, when viewed in a direction perpendicular to the longitudinal center axis, is directed in the opposite direction to the direction of travel.An inclination directed against the direction of travel refers to an inclination where the angle between the inclined surface and the longitudinal center axis is smaller when opposed to the direction of travel than when parallel to it. An inclined centering device has a shape that is advantageous with regard to its flow characteristics. Furthermore, in collar-shaped centering devices, the size of the area used for guiding the centering device along the pipeline can be influenced particularly easily by dimensioning sections running parallel to the longitudinal center axis.

[0011] Advantageously, a part of the centering device used for guidance in the pipeline has an anisotropic coefficient of friction, wherein the coefficient of friction is lower, in particular, in the direction of movement of the device than against the direction of movement. The anisotropic coefficient of friction is preferably due to the shape of the centering device. In particular, the anisotropic coefficient of friction is based on a centering device that is inclined from the longitudinal center axis in the opposite direction of movement.

[0012] The centering device is designed to be elastically deformable or elastically mounted. Preferably, depending on the direction in which the device is moved, it can have different shapes or positions and thus differently sized edges or surfaces that interact with the inner wall of the pipe to guide the device, for example, due to different curvatures, bends, and / or angular positions of the centering device. However, the anisotropic coefficient of friction can also be achieved in other ways, such as through anisotropic surface properties of the guiding part of the centering device. This allows influence to be exerted on the direction in which the movement of the device is favored, or in which the device is driven by means of a vibration generator.In particular, the movement of the device is only favored in the direction of movement by the anisotropic coefficient of friction, or the device is only driven in the direction of movement by means of vibration generators, supplementing and especially alongside a reduction of friction.

[0013] In a preferred embodiment, the centering device is made of polyurethane. This makes the centering device particularly elastically deformable and allows it to develop the anisotropic coefficient of friction described in the previous paragraph due to its deformability. Furthermore, the centering device is thus comparatively wear-resistant.

[0014] In a further preferred embodiment of the invention, the vibration generator is arranged on or in the central body. This allows the existing installation space of the central body, which is particularly elongated along the longitudinal axis of the pipeline, to be used to accommodate the vibration generator. The device is thus designed to be particularly space-saving. Furthermore, the distance between the vibration generator and any control unit that may also be arranged on or in the central body is advantageously small.

[0015] Alternatively or additionally, the vibration generator is preferably located on or in the

[0016] A centering device is arranged. Since reducing friction between the centering device and the inner pipe wall depends on vibrations of the centering device, it is advantageous for the transmission of these vibrations that the distance between the vibration generator and the centering device is as small as possible, or ideally, that there is no distance at all. When directly attached to the centering device, the central body is not necessarily required for transmitting vibrations from the vibration generator to the centering device. Therefore, the central body is designed to be decoupled from the vibrations of the centering device. This can be advantageous, for example, for any electronic components of the device to prevent material fatigue.

[0017] Preferably, the vibration generator is designed as an unbalanced motor. Unbalanced motors are relatively inexpensive, lightweight, and small, so the weight and dimensions of the device are also advantageously low. Alternatively or additionally, the vibration generator can be designed, for example, as a piezoelectric actuator, electromagnetic exciter, flow-induced exciter, or a combination thereof. The essential requirement is that the vibration generator can produce vibrations of the centering device.

[0018] A vibration generator designed as an unbalanced motor preferably comprises an unbalanced body that is movable in a plane transverse to the direction of movement of the device, and in particular is rotatably mounted. In the case of a vibration generator designed as an unbalanced motor, the movement of the unbalanced body in a plane can generate vibrations of the centering device in that plane. In the case of a vibration generator designed alternatively or additionally as a piezoelectric actuator, electromagnetic exciter, flow-induced exciter, or by means of a combination thereof, this vibration generator also generates vibrations of the centering device in a plane transverse to the direction of movement of the device. Previous tests have shown that the friction between the centering device and the pipeline can be reduced by means of such a vibration generator, thereby facilitating the movement of the device.Furthermore, a vibration generator that produces vibrations transverse to its longitudinal axis can be arranged longitudinally in the particularly elongated central body and thus in a particularly space-saving and / or form-fitting manner.

[0019] In a preferred embodiment, the device comprises at least two vibration generators, each designed as an unbalance motor. One of the vibration generators has an unbalance body movable, and in particular rotatably mounted, in a first plane parallel to the direction of movement of the device, and the other vibration generator has an unbalance body movable, and in particular rotatably mounted, in a second plane parallel to the first plane. These vibration generators can be provided as an alternative or supplement to the vibration generator described in the previous section. In the case of vibration generators designed as unbalance motors, the movement of the respective unbalance body in the respective plane can generate vibrations of the centering device in that plane.In the case of vibration generators designed as piezoelectric actuators, electromagnetic exciters, flow-induced exciters, or a combination thereof, vibrations in the same planes can be generated by the vibration generators. Specifically, the first and second planes, viewed in one direction along the longitudinal axis of the central body, lie on opposite sides of the longitudinal axis. The planes preferably have the same distance from the longitudinal axis. Previous tests have shown that the friction between the centering device and the pipeline can also be reduced by means of such vibration generators, thereby facilitating the movement of the device.

[0020] In a further preferred embodiment of the invention, the device, as an alternative or supplement to the embodiments described in the previous two paragraphs, comprises at least two vibration generators, each designed as an unbalance motor. One of the two vibration generators has an unbalance body movable, in particular rotatably mounted, in a first plane parallel to the direction of movement of the device, and the other vibration generator has an unbalance body movable, in particular rotatably mounted, in a second plane perpendicular to the first plane. In the case of vibration generators designed as unbalance motors, vibrations of the centering device in the respective plane can be generated by the movement of the respective unbalance body in that plane.In the case of vibration generators designed as piezoelectric actuators, electromagnetic exciters, flow-induced exciters, or a combination thereof, vibrations of the centrifugal device can be generated, particularly in the same planes. Previous tests have shown, firstly, that the friction between the centering device and the pipeline can be reduced with such vibration generators, thereby facilitating the movement of the device. Secondly, it was surprisingly found that such a design also makes it possible to drive the device.

[0021] Further advantages and details of the invention will become apparent from the embodiments schematically depicted in the figures, which are described below. Where appropriate, equivalent elements of the invention are designated with the same reference numerals. The features of the embodiments can also be combined to form further embodiments, where appropriate. The figures show, schematically:

[0022] Fig. 1a shows a device according to the invention in perspective view,

[0023] Fig. 1b the device from Fig. 1 in direction lb from Fig. 1 ,

[0024] Fig. 2 shows another device according to the invention in a perspective view,

[0025] Fig. 3a shows another device according to the invention in perspective view,

[0026] Fig. 3b the device from Fig. 3a in direction 11 lb from Fig. 3a,

[0027] Fig. 4a shows another device according to the invention in perspective view,

[0028] Fig. 4b shows the device from Fig. 4a in the direction of IV-b from Fig. 4a, Fig. 5 shows another device according to the invention in a perspective view,

[0029] Fig. 6 shows another device according to the invention in perspective view,

[0030] Fig. 7 shows another device according to the invention in perspective view.

[0031] The embodiment of a device 2 for movement in a pipeline 9, shown in perspective view in Fig. 1a, has a central body 4. In this embodiment, a centering device 8 is arranged at each of the ends of the central body 4 that lie in the direction of a longitudinal center axis 6 of the central body 4. The device 2 can be supported against an inner wall 10 of the pipeline 9 by means of these centering devices 8 when the device 2 moves in the direction of movement 12. The centering devices 8 are each connected to the central body 4 by means of fastening elements 14, which are designed in particular as screw connections. Since the centering devices 8 each have a radial axis 16 (see Fig. 1a) when viewed in the direction of a longitudinal center axis 6, the device 2 can be supported against the inner wall 10 of the pipeline 9 when moving in the direction of movement 12.1 b) When fluid flows through the pipe 9, a pressure difference arises between a pipe section 18 located upstream of the centering devices 8 in the direction of the longitudinal axis 6 and a pipe section 20 located downstream of the centering devices 8 in the direction of the longitudinal axis 6. This pressure difference exerts a force on the device 2, thereby at least partially driving the device 2. Furthermore, the device 2 has a vibration generator 22 that generates vibrations in at least one of the centering devices 8, in particular in each of the centering devices 8. In this case, the vibration generator 22 is designed as a piezoelectric actuator, but it could also be designed, for example, as an unbalanced motor or similar device.Furthermore, the depicted vibration generator 22 is arranged within the central body 4, but can also be arranged on the central body 4. The vibration generator 22, designed here as a piezoelectric actuator, generates vibrations of the central body 4, and thus also of the centering devices 8, which are positively connected to it, in the form of ultrasonic vibrations. These vibrations of the centering devices 8 reduce friction between the respective centering device 8 and the inner wall 10 of the pipe, thereby facilitating the movement of the device 2. In particular, the device 2 is actively driven by the vibrations of the centering devices 8.

[0032] Figure 1b shows that the device 2 from Figure 1a has two centering devices 8 arranged one behind the other in the direction of travel 12, between which a space 24 is created. The vibration generator 22 is preferably arranged in this space 24, particularly without increasing the dimensions of the device 2 and especially protected by the centering devices 8. When the device 2 is arranged in the pipeline 9, the longitudinal center axis 6 of the central body 4 coincides, in particular as shown, with a longitudinal axis 11 of the pipeline 9. In this case, the centering devices 8 are collar-shaped. They have a planar design transverse to the longitudinal center axis 6, i.e., in the radial direction 16, in which at least one side lying in the direction of the longitudinal center axis 6, in this case the side 26 pointing in the direction of travel 12, is inclined.The side 26 pointing in the direction of movement 12 is inclined, in particular, opposite to the direction of movement 12, giving the centering devices 8 a shape that is advantageous with regard to their flow behavior. As an alternative to the collar-shaped design of the centering devices 8, they can be disc-shaped. However, a collar-shaped design of the centering devices 8 is advantageous in order to achieve an anisotropic coefficient of friction by means of the shape of the centering devices 8. Depending on whether the device 2 moves in or against the direction of movement 12, the centering devices 8 then have different shapes due to elastic deformation and thus differently sized surfaces that interact with the inner pipe wall 10 to guide the device 2.This facilitates the movement of the device 2 in only one direction along the longitudinal center axis 6, particularly in the direction of movement 12 and not against the direction of movement 12. To achieve elastic deformability of the centering device 8, it is preferably made of an elastically deformable material, in particular polyurethane. The centering device 8 is then also particularly wear-resistant.

[0033] Fig. 2 shows a further embodiment of a device 2 according to the invention, comprising a central body 4, which is elongated, in particular along the longitudinal center axis 6, and two centering devices 8 arranged on the central body 4. A vibration generator 22 is arranged on the central body 4 to generate vibrations in the centering devices 8, which are in particular elastic. The vibration generator 22, which in this case is designed as an unbalanced motor, is connected to the central body 4 via fastening means 14, in particular by frictional connection.

[0034] The further embodiment of a device 2 according to the invention shown in Fig. 3a also has a central body 4 and centering devices 8 arranged thereon. Several vibration generators 22, in this case designed as electromagnetic exciters, in particular electromagnets, are attached to each of the centering devices 8. The vibration generators 22 can be arranged in the centering device 8 alternatively or additionally. A connection between the vibration generators 22 and the respective centering device 8 can be made, for example, by an adhesive bond or similar. Vibrations, in particular a resonance, of the respective centering devices 8 are generated by means of the electromagnetic exciters, thereby achieving the aforementioned advantages with regard to friction reduction.For example, the electromagnets connected to the centering device 8 can be excited by means of an exciter, so that they and thus also the centering device 8 are set into forced oscillations.

[0035] In Fig. 3b, the device 2 from Fig. 3a is shown viewed in one direction along the longitudinal center axis. In this view, the centering device 8, projected onto a plane perpendicular to the longitudinal center axis 6, which in this case corresponds to the plane of consideration, forms a surface that is at least substantially, and in this case, in particular, completely, closed. The propulsion of the device 2 is thus improved when fluid flows through the pipe 9 and flows over this surface. The eight vibration generators 22 are arranged on the inclined side 26 of the centering device 8, which points in the direction of travel. They are also arranged uniformly around the longitudinal center axis 6, that is, with equal distances 28 between them in the circumferential direction.

[0036] Figures 4a and 4b show a further embodiment of a device 2 according to the invention, comprising a central body 4 and two centering devices 8 arranged thereon. A vibration generator 22 is not shown in this embodiment. The centering devices 8 each have at least one recess 30, and in particular a plurality of recesses 30, for fluid flow through the centering device 8. By dimensioning the recesses 30, the size of the area exposed to the fluid flow, and thus the propulsion of the device 2, can be influenced.

[0037] In a further embodiment of a device 2 according to the invention, shown in Fig. 5, a vibration generator 22 designed as an unbalanced motor is arranged within a central body 4, which is in particular tubular (shown transparently and with dashed lines). The vibration generator 22 can be arranged in an interior space 32 of the central body 4 or in a recess (not shown) of the central body 4 provided for receiving the vibration generator 22. It is essential that the vibration generator 22 is connected to the at least one centering device 8 in a way that transmits vibrations. In this case, an unbalanced element 34 of the vibration generator 22 is movably, in particular rotatably, mounted in a plane transverse to the direction of travel 12. Thus, friction-reducing vibrations of the centering devices 8 can also be generated in this plane.

[0038] Fig. 6 shows a further embodiment of a device 2 according to the invention with two vibration generators 22 arranged on the central body 4. One of the vibration generators 22 has an unbalanced body 34 movable in a first plane parallel to the direction of movement, in particular rotatably mounted. The other vibration generator 22 has an unbalanced body movable in a second plane parallel to the direction of movement of the device, in particular rotatably mounted, wherein the second plane is in particular arranged parallel to the first plane. This allows friction-reducing vibrations of the centering devices 8 to be generated in these planes, thereby improving the movement of the device 2.

[0039] Figure 7 shows a further embodiment of a device 2 according to the invention, comprising a central body 4 and at least one centering device 8. A first vibration generator 22, with an unbalanced body 34 movable in a first plane parallel to the direction of movement 12 of the device 2, and in particular rotatably mounted, is arranged on the central body 4. A second vibration generator 22, with an unbalanced body 34 movable in a second plane perpendicular to the first plane, and in particular rotatably mounted, is also arranged on the central body 4. Previous tests have shown that the aforementioned arrangement of vibration generators 22 designed as unbalanced motors reduces friction between the centering device 8 and the pipeline 9 (see Figure 1a) and actively drives the device 2. The movement of the device 2 is thus significantly improved.Such an arrangement of the vibration generators 22 is therefore particularly preferred. Furthermore, in devices 2 with any measuring devices, which are regularly used, for example, in inspections of pipelines 9, the acquisition of measurement data is also improved by the improved running behavior of the device 2.

[0040] If the vibration generators 22 in the devices 2 shown in Figures 2 and 5 to 7 are not designed as unbalance motors, but for example as piezoelectric actuators, electromagnetic exciters, flow-induced exciters, or combinations thereof, the respective vibration generators 22 preferably generate vibrations of the centering devices 8 in the same planes by means of an arrangement analogous to the illustrated unbalance motors. For this purpose, the vibration generators are arranged in such a way that excitation of the centering device 8 occurs in the aforementioned plane(s). In the case of vibration generators 22 designed as flow-induced exciters, a flow around or through the device 2 is particularly facilitated, through which vibration-inducing forces act between the fluid and the device 2.The device 2 has in particular flow elements around or flow elements through it, such as recesses, tunnels or the like.

[0041] The devices according to the invention each exhibit an improved ability to move within a pipeline, particularly with reduced friction. If the devices become stuck, they can be restarted. Furthermore, the devices can be actively driven by the aforementioned design features. Additionally, a reduction in the static friction effect results in smoother running and thus improved data acquisition.

Claims

Claims 1. Device, in particular an inspection or cleaning pig, for movement in a pipeline, comprising a central body, at least one centering device, in particular arranged on the central body, for supporting the device on an inner wall of the pipeline, wherein the centering device, viewed in the direction of a longitudinal central axis of the central body, forms a surface extending in a radial direction, in particular away from the central body, around the longitudinal central axis, and at least one vibration generator for generating vibrations of the centering device.

2. Device according to claim 1, characterized in that the surface formed by the centering device is at least substantially closed.

3. Device according to one of the preceding claims, characterized in that the device has two centering devices arranged one behind the other in a direction of movement of the device, in particular wherein each centering device is assigned its own vibration generator.

4. Device according to one of the preceding claims, characterized in that the centering device is designed in the shape of a disc or collar.

5. Device according to one of the preceding claims, characterized in that a part of the centering device serving for guidance in the pipeline has an anisotropic coefficient of friction, wherein the coefficient of friction is particularly lower in the direction of movement of the device than against the direction of movement.

6. Device according to one of the preceding claims, characterized in that the centering device is made of polyurethane.

7. Device according to one of the preceding claims, characterized in that the vibration generator is arranged on or in the central body.

8. Device according to one of the preceding claims, characterized in that the vibration generator is arranged on or in the centering device.

9. Device according to one of the preceding claims, characterized in that the vibration generator is designed as an unbalanced motor.

10. Device according to claim 9, characterized in that the vibration generator has an unbalanced body movable in a plane transverse to the direction of movement of the device, in particular a rotatable mounting.

11. Device according to claim 9 or 10, characterized in that the device has at least two vibration generators, one of which has an unbalanced body movable in a first plane parallel to the direction of movement of the device, in particular a rotatable one, and the other vibration generator has an unbalanced body movable in a second plane parallel to the first plane, in particular a rotatable one.

12. Device according to one of claims 9 to 11, characterized in that the device has at least two vibration generators, wherein one of the vibration generators has an unbalanced body movable in a first plane parallel to the direction of movement of the device, in particular rotatably mounted, and the other vibration generator has an unbalanced body movable in a second plane perpendicular to the first plane, in particular rotatably mounted.

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