Cleaning and defect detection on a pipeline wall

Abstract

A device and a system comprising at least two devices for cleaning a pipeline wall or for detecting defects on the pipeline wall are disclosed. A method for cleaning a pipeline wall or for detecting defects on the pipeline wall is also disclosed. The method comprises the following method steps: applying (100) a preliminary pressure to a fluid, in a pressure chamber; applying (200) a pulsating pressure, adding to the preliminary pressure, to the fluid in the pressure chamber, by way of a pulse generator; and generating (300) a pulsating supersonic free jet from the fluid, by way of at least one relief nozzle fluidically connected to the pressure chamber; or comprising method steps corresponding to features of the device, the system or the cleaning unit. A computer program corresponding to the method, a data-carrier signal transferring the computer program, and a computer-readable medium comprising the implementational commands of the method are also disclosed.

Description

[0001] Cleaning and defect detection on a pipeline wall

[0002] Technical area

[0003] The invention relates to a device and a system with at least two devices for cleaning pipe walls or for detecting defects on the pipe wall.

[0004] The present invention also relates to a method for cleaning pipe walls or for detecting defects on the pipe wall.

[0005] Furthermore, the present invention relates to a computer program according to the method, a data carrier signal transmitting the computer program and a computer-readable medium comprising the instructions of the method for execution.

[0006] Background of the invention

[0007] Currently available are cleaning devices and inline inspection devices that are inserted into the pipeline for their respective functions. The problem with existing cleaning devices is that they cannot adequately remove all types of contaminants, such as wax. Inline inspection devices may not be able to perform maintenance tasks satisfactorily if the pipelines are contaminated.

[0008] Description of the invention

[0009] Based on this situation, it is an object of the present invention to improve previously known cleaning devices and inline inspection devices. In particular, the field of application of an inline inspection device and / or a cleaning device is to be expanded. The object of the invention is achieved by the features of the independent main claims. Advantageous embodiments are specified in the subclaims. To the extent technically feasible, the teachings of the subclaims can be combined arbitrarily with the teachings of the main and subclaims.

[0010] Accordingly, the object is achieved by a device for cleaning a pipeline wall. The device comprises: a pressure chamber configured to receive a fluid and apply a pre-pressure to the fluid; a pulse generator configured to apply a pulsating pressure, additive to the pre-pressure, to the fluid in the pressure chamber; and at least one expansion nozzle fluidically connected to the pressure chamber, configured to generate a pulsating supersonic free jet from the fluid.

[0011] Furthermore, the object is achieved by a system for cleaning pipeline walls and for detecting defects on a pipeline wall, comprising at least two devices arranged at a distance from one another according to at least one of the preceding claims; a receiving system configured to receive ultrasonic echoes emitted by the pipeline wall, excited by ultrasonic waves generated by the devices at a coupling frequency of the pipeline wall; and an evaluation system configured to generate a product of a plurality of ultrasonic echoes measured simultaneously, wherein the ultrasonic echoes are induced by the at least two spaced-apart devices.

[0012] Furthermore, the object is achieved by a cleaning device for cleaning a pipeline wall, comprising a device body with a Venturi nozzle and at least one device and / or at least one system.

[0013] Furthermore, the object is achieved by a method for pipe wall cleaning or for detecting defects on a pipe wall, comprising the following method steps: applying a pre-pressure to a fluid in a pressure chamber; applying a pulsating pressure, additive to the pre-pressure, to the fluid in the pressure chamber via a pulse generator; and generating a pulsating supersonic free jet from the fluid via at least one expansion nozzle fluidically connected to the pressure chamber.

[0014] The method preferably comprises method steps corresponding to features of the device, the system, or the cleaning device according to one of the modified embodiments described below.

[0015] It is preferred that the sequence of process steps can be varied, unless technically required in an explicit order. However, the aforementioned sequence of process steps is particularly preferred.

[0016] Furthermore, the object is achieved by a computer program comprising instructions which, when the computer program is executed by a computer, cause the computer to carry out a method according to the aforementioned claim.

[0017] In addition, the task is solved by a data carrier signal that transmits the previously described computer program.

[0018] Furthermore, the object is achieved by a computer-readable medium comprising instructions which, when executed by a computer, cause the computer to carry out a previously described method.

[0019] The basic idea of ​​the invention and individual aspects of the claimed subject matter are explained below, and preferred modified embodiments of the invention are further described below. Explanations, particularly regarding advantages and definitions of features, are essentially descriptive and preferred, but not limiting, examples. If an explanation is limiting, this will be expressly stated.

[0020] The basic idea of ​​the present invention is to generate pressure surges in the medium in the pipeline using ultrasound. This pressure surge serves, on the one hand, to detach dirt from very small defects in the pipeline and, on the other hand, to excite the pipeline wall to vibrate. These vibrations emit ultrasonic echoes, which in turn allow defects to be detected using the ultrasonic echoes. Simultaneous cleaning and defect detection have proven particularly advantageous for pipelines filled with media at low pressure. Such a pressure can be, for example and not limited to, between 10 bar or 10 * 10 A 5 Pa to 60 bar or 60 * 10 A 5 Pa, preferably about 40 bar or about 40 * 10 A5 Pa. Testing of metallic and non-metallic pipelines is conceivable. Alternatively, workpieces, e.g., sheet metal or (sub-)components, can also be inspected for defects or, in particular, cleaned specifically at the defects using the method / device according to the invention.

[0021] The combination of a pressure chamber and a pressure relief nozzle has proven particularly advantageous for generating the supersonic free jet. To achieve a critical pressure ratio for the supersonic free jet, gas is compressed both statically and pulsatingly in the pressure chamber.

[0022] The device according to the invention can be installed singly or multiple times on a cleaning device used for cleaning metallic and non-metallic pipelines. The device(s) is / are arranged on the cleaning device in such a way that a bypass flow is generated along the cleaning device in the pipeline. For example, the device(s) can be integrated as a module in the cleaning device / inspection device. The bypass flow serves to transport the dirt away. With multiple installations on the cleaning or inspection device, a product can be calculated from the received ultrasonic echo signals, which can be used to better localize a defect.

[0023] It has been found that cleaning of very small defects in the pipeline, such as pitting, is particularly possible. However, using state-of-the-art cleaning methods, pitting was very difficult to clean because the contamination was localized in the depressions of the pitting. Wax deposits can also be removed very easily. In particular, the wax deposits are made of soft wax, which usually smears cleaning tools so that they no longer clean. Encrusted wax that is stuck to the pipeline can also be loosened. Furthermore, black dust, i.e. fine dust that is in the pipe, can be easily removed.

[0024] According to a modified embodiment of the invention, the expansion nozzle is a Laval nozzle. A Laval nozzle is a nozzle in which the cross-section initially narrows and then widens, with the transition from one part to the other being continuous. The cross-sectional area is usually circular or elliptical at every point. Laval nozzles have a simple design and are therefore inexpensive to manufacture.

[0025] According to a modified embodiment of the invention, it is provided that the device is designed to generate the supersonic free jet with a pressure profile which has a pressure surge in the supersonic range in a first period and a pressure surge in the subsonic range in a second period.

[0026] This allows for efficient cleaning of the pipeline on the one hand and removal of dissolved dirt on the other.

[0027] According to a modified embodiment of the invention, the device is designed to generate the supersonic free jet with a core jet having a number of longitudinal and transverse modes of two to four each. This has been found to enable particularly efficient cleaning of the pipeline.

[0028] According to a modified embodiment of the invention, the device is designed to generate the supersonic free jet with a pressure profile in a range of a Mach number of 2.3 in the supersonic range and a Mach number of 0.5 in the subsonic range, in particular designed to generate the supersonic free jet with a pressure profile in a range of a Mach number of 1.6 in the supersonic range and a Mach number of 0.7 in the subsonic range. For these ranges, it has been found that particularly efficient and, at the same time, energy-saving cleaning and removal of the loosened dirt is possible. According to a modified embodiment of the invention, the expansion nozzle is arranged and designed such that a core jet of the supersonic free jet encloses an angle in a range of zero to twenty degrees with a surface normal of an inner surface of the pipeline wall.For an inclined arrangement of the relaxation nozzle, it has been found that dirt can be transported particularly effectively in front of the cleaning device if the device is installed on such a cleaning device.

[0029] According to a modified embodiment of the invention, the device is designed to generate, with the supersonic free jet, ultrasonic waves suitable for coupling into the pipeline wall, in particular, to generate, with the supersonic free jet, ultrasonic waves that induce a Lamb wave with at least one AO ​​and one S0 mode in the pipeline wall. This advantageously allows defects to be detected, e.g., based on received ultrasonic echoes, while simultaneously enabling cleaning of the pipeline.

[0030] According to a modified embodiment of the invention, a supersonic free jet generated by the expansion nozzle projects toward a discharge pipe connected to the Venturi nozzle. Dislodged dirt, which is loosened by the free jet, can thus be efficiently removed via the discharge pipe of the Venturi nozzle. Particularly if a chamber is formed between the cleaning and inspection device housing and the pipeline wall, the discharge pipe can be efficiently vacuumed via the suction flow generated in the Venturi nozzle.

[0031] According to a modified embodiment of the invention, the cleaning device comprises a chamber in the area of ​​the expansion nozzle, which is designed such that the chamber, together with a pipeline wall, encloses a jet outlet area of ​​the expansion nozzle. The chamber has the advantage that stirred-up dirt remains in a targeted area of ​​the pipeline or can be transported out of it. Furthermore, other areas surrounding the cleaning / inspection device can be used for other functions. Several independently installed inspection areas on the cleaning / inspection device are also conceivable, in which cleaning / detection of defects can be carried out independently of one another.

[0032] According to a modified embodiment of the invention, the expansion nozzle of the cleaning device is arranged and configured on the device housing in such a way that a core jet of the supersonic free jet is angled with respect to a surface normal of an inner pipe wall surface, and the core jet forms an acute angle with a longitudinal axis of the Venturi nozzle, which opens toward an outlet of the Venturi nozzle. This facilitates more effective removal of loosened dirt. Furthermore, a larger area of ​​the pipeline can be treated with the free jet in a given time interval.

[0033] According to a modified embodiment of the invention, the cleaning device housing and the Venturi nozzle are designed in such a way that a bypass flow is generated in the Venturi nozzle during operation of the expansion nozzle. This facilitates the targeted removal of dirt, which is, for example, sucked in from the intake pipe. The Venturi nozzle can be positioned anywhere relative to the body of the cleaning / inspection device, which advantageously allows a region in the pipeline to be defined to which the dirt is transported without impairing further cleaning work or defect detection in the pipeline.

[0034] According to a modified embodiment of the invention, it is provided that in the cleaning device the Venturi nozzle has an inlet on a first conically tapered section and an outlet on a second section, wherein the Venturi nozzle is arranged and designed such that it extends with its longitudinal axis along a pipeline longitudinal axis, and wherein the removal ear connects the first section to the second section.

[0035] According to a modified embodiment of the invention, the cleaning device comprises at least one device arranged at the outlet of the Venturi nozzle; or comprises at least one device arranged at the outlet of the Venturi nozzle and at least one device arranged at the inlet of the Venturi nozzle. The devices can, for example, operate at different ultrasonic frequencies and generate supersonic free jets with different properties. This advantageously allows different defects to be examined and detected. Furthermore, different types / sizes of dirt deposits can be cleaned efficiently and simultaneously.

[0036] According to a modified embodiment of the invention, the device is designed to change a geometry such that a frequency of generated ultrasonic waves is modulated. For example, the geometry can be changed by a rotating body on the ultrasonic wave-generating part of the device. This can advantageously improve the accuracy of detecting defects by the generated ultrasonic waves. Thus, the geometry of an ultrasound-generating part of the device is secretly changed, for example, to enable frequency modulation of the ultrasonic waves. Optionally, a bandpass filter can be used, with which the received signal of the ultrasonic echo can be transformed into multiple pulses.In a subsequent processing step of the data obtained from the ultrasound signal, the amplitude and arrival time of the signal can then be used to detect defects.

[0037] The ultrasonic wave-generating part of the device and the ultrasonic wave-receiving part of the device can be arranged separately from each other. In this case, the ultrasonic wave-receiving part can also be arranged outside the pipeline.

[0038] Short description of the drawings

[0039] The invention will be explained in more detail below with reference to preferred embodiments and the accompanying drawings. The wording "figure" is abbreviated to "Fig." The drawings show:

[0040] Figure 1 is a schematic view of a device according to a preferred embodiment of the invention;

[0041] Figure 2 is a schematic view of a cleaning device according to a first preferred embodiment of the invention;

[0042] Figure 3 is a schematic view of the cleaning device according to a second preferred embodiment of the invention; and

[0043] Figure 4 is a flowchart of a method according to an embodiment of the invention.

[0044] Detailed description of the implementation examples

[0045] The described embodiments are merely examples that can be modified and / or supplemented in a variety of ways within the scope of the claims. Each feature described for a specific embodiment can be used independently or in combination with other features in any other embodiment. Each feature described for an embodiment of a specific claim category can also be used correspondingly in an embodiment of a different claim category.

[0046] Figure 1 shows a schematic view of a device 1 according to a preferred embodiment of the invention. The device 1 is intended for cleaning a pipeline wall 2. The pipeline wall 2 may have defects in which dirt deposits are located. Cleaning is ensured by the device 1 according to the invention, particularly in the case of defects in the form of pitting.

[0047] The device 1 comprises a pressure chamber 3, a pulse generator (not shown), and a pressure relief nozzle 4 fluidically connected to the pressure chamber 3. The pressure chamber 3 is designed to contain a fluid and apply a pre-pressure to the fluid. The fluid can, for example, be taken from the environment of the device 1 and accommodated in the pressure chamber 3.

[0048] The pulse generator is designed to apply a pulsating pressure to the fluid in the pressure chamber 3, which is additive to the initial pressure. The at least one expansion nozzle 4 fluidically connected to the pressure chamber 3 is designed to generate a pulsating supersonic free jet from the fluid. The expansion nozzle 4 is a Laval nozzle.

[0049] In the present case, the Laval nozzle is oriented perpendicular to a surface normal N of the pipeline wall 2. However, the device 1, in particular its Laval nozzle, can also be oriented slightly inclined to the pipeline wall 2.

[0050] Figure 2 shows a schematic view of a cleaning device 20 according to a first preferred embodiment of the invention.

[0051] The cleaning device 20 is intended for cleaning a pipeline wall 2 and comprises a device body 21 with a Venturi nozzle 22 and a device 1 arranged on a discharge pipe 23 formed from two partial pipes. The partial pipes are each connected to a chamber 24 formed by the pipeline wall 2 and the device body 21 of the cleaning device 20.

[0052] The Venturi nozzle 22 has an inlet 25 at a first conically tapered section and an outlet 26 at a second section. The Venturi nozzle 22 is arranged and configured such that its longitudinal axis extends along a pipeline's longitudinal axis. The takeoff tube 23 connects the first section to the second section of the Venturi nozzle 22.

[0053] In the cleaning device 20, the expansion nozzle 4 is arranged such that a supersonic free jet generated by the expansion nozzle 4 protrudes toward a discharge pipe 23 connected to the Venturi nozzle 22. The expansion nozzle 4 is arranged and configured on the device housing 21 such that a core jet of the supersonic free jet (not shown) is angled relative to the surface normal N of an inner surface of the pipeline wall. Furthermore, the expansion nozzle 4 is designed and arranged such that the core jet forms an acute angle with a longitudinal axis (not shown) of the Venturi nozzle 22, which angle opens toward the outlet 25 of the Venturi nozzle 22.

[0054] Figure 3 shows a schematic view of a cleaning device 30 according to a second preferred embodiment of the invention. The cleaning device 30 is constructed similarly to the cleaning device 20. However, the cleaning device 30 has a system 10. It is suitable for cleaning pipeline walls and for detecting defects on a pipeline wall 2.

[0055] The system 10 comprises two devices 1 arranged at a distance from one another, as previously described, a receiving system 11, and an evaluation system (not shown). The receiving system 11 is configured to receive ultrasonic echoes emitted by the pipeline wall 2, excited by ultrasonic waves generated by the devices 1 at a coupling frequency of the pipeline wall 2. The evaluation system is configured to generate a product of several ultrasonic echoes measured simultaneously, wherein the ultrasonic echoes are induced by the two spaced-apart devices 1.

[0056] Figure 4 shows a flowchart of a method according to an embodiment of the invention. The method is intended for pipe wall cleaning and comprises the following steps:

[0057] According to a step with reference number "100," a pre-pressure is applied to a fluid in a pressure chamber 3. According to a step with reference number "200," a pulsating pressure, additive to the pre-pressure, is applied to the fluid in the pressure chamber 3 via a pulse generator. Finally, according to a step with reference number "300," a pulsating supersonic free jet is generated from the fluid via at least one expansion nozzle 4 fluidically connected to the pressure chamber 3. List of Reference Symbols

[0058] 1 device

[0059] 2 Pipe wall

[0060] 3 pressure chambers

[0061] 4 relaxation jets

[0062] 10 systems

[0063] 11 Reception system

[0064] 20 Cleaning device according to the first embodiment

[0065] 21 Device body

[0066] 22 Venturi nozzle

[0067] 23 Take-off pipe

[0068] 24 chambers

[0069] 25 Outlet

[0070] 26 Entrance

[0071] 30 Cleaning device according to the second embodiment

[0072] N surface normal

[0073] 100 Applying a pre-pressure to a fluid in a pressure chamber

[0074] 200 Applying a pulsating pressure to the fluid in the pressure chamber, which is additive to the pre-pressure, via a pulse generator

[0075] 300 Generating a pulsating supersonic free jet from the fluid, via at least one expansion nozzle fluidically connected to the pressure chamber

Claims

Patent claims 1. Device (1) for cleaning a pipeline wall (2), comprising a pressure chamber (3) designed to receive a fluid and for Applying a pre-pressure to the fluid; a pulse generator, designed to apply a pulsating pressure additive to the pre-pressure to the fluid in the pressure chamber (3); and at least one expansion nozzle (4) fluidically connected to the pressure chamber (3), designed to generate a pulsating supersonic free jet from the fluid.

2. Device (1) according to claim 1, designed to generate the supersonic free jet with a pressure profile which has a pressure surge in the supersonic range in a first period and a pressure surge in the subsonic range in a second period.

3. Device (1) according to at least one of claims 1 or 2, designed to generate the supersonic free jet with a core jet having a number of longitudinal and transverse modes of two to four each.

4. Device (1) according to at least one of the preceding claims, designed to generate the supersonic free jet with a pressure profile in a range of a Mach number of 2.3 in the supersonic range and a Mach number of 0.5 in the subsonic range, in particular designed to generate the supersonic free jet with a pressure profile in a range of a Mach number of 1.6 in the supersonic range and a Mach number of 0.7 in the subsonic range.

5. Device (1) according to at least one of the preceding claims, wherein the expansion nozzle (4) is arranged and designed such that a Core jet of the supersonic free jet with a surface normal (N) of a Pipe wall inner surface encloses an angle in a range of zero to twenty degrees.

6. Device (1) according to at least one of the preceding claims, designed to generate, with the supersonic free jet, ultrasonic waves suitable for coupling into the pipeline wall (2), in particular designed to generate, with the supersonic free jet, ultrasonic waves which induce a Lamb wave with at least one A0 and one S0 mode in the pipeline wall (2).

7. Device (1) according to at least one of the preceding claims, designed to change a geometry such that a frequency of generated ultrasonic waves is modulated.

8. A system (10) for cleaning pipeline walls and for detecting defects on a pipeline wall (2), comprising at least two devices (1) according to at least one of the preceding claims, arranged at a distance from one another; a receiving system (11) configured to receive ultrasonic echoes emitted by the pipeline wall (2) when excited by ultrasonic waves generated by the devices (1) at a coupling frequency of the pipeline wall (2); and an evaluation system configured to generate a product of a plurality of ultrasonic echoes measured simultaneously, the ultrasonic echoes being induced by the at least two devices (1) spaced apart from one another.

9. Cleaning device (20, 30) for cleaning a pipeline wall (2), comprising a device body (21) with a Venturi nozzle (22) and at least one device (1) according to at least one of the preceding claims and / or at least one system (10) according to the preceding claim.

10. Cleaning device (20, 30) according to the preceding claim, wherein the expansion nozzle (4) is arranged such that a supersonic free jet generated by the expansion nozzle (4) projects in the direction of a take-off pipe (23) connected to the Venturi nozzle (22).

11. Cleaning device (20, 30) according to the preceding claim, wherein the removal pipe (23) in the region of the expansion nozzle (4) has a Chamber (24) which is designed such that the chamber (24) together with a pipeline wall (3) encloses a jet outlet region of the expansion nozzle (4).

12. Cleaning device (20, 30) according to at least one of the preceding claims, wherein the expansion nozzle (4) is arranged and designed on the device housing (21) in such a way that a core jet of the supersonic free jet is angled with respect to a surface normal (N) of an inner surface of the pipeline wall and the core jet encloses an acute angle with a longitudinal axis of the Venturi nozzle (22), which is open to an outlet (25) of the Venturi nozzle (22).

13. Cleaning device (20, 30) according to at least one of the preceding claims, wherein the device housing (21) and the Venturi nozzle (22) are designed such that a bypass flow is generated in the Venturi nozzle (22) during operation of the expansion nozzle (4).

14. Cleaning device (20, 30) according to at least one of the preceding claims, comprising at least one arranged at the outlet (26) of the Venturi nozzle (22) Device (1); or comprising at least one device (1) arranged at the outlet (26) of the Venturi nozzle (22) and at least one device (1) arranged at the inlet (25) of the Venturi nozzle (22).

15. Method for cleaning the pipe wall or for detecting defects on the pipe wall (2), comprising the following method steps: Applying (100) a pre-pressure to a fluid in a pressure chamber (3); Applying (200) a pulsating pressure additive to the pre-pressure to the fluid in the pressure chamber (3) via a pulse generator; and Generating (300) a pulsating supersonic free jet from the fluid via at least one expansion nozzle (4) fluidically connected to the pressure chamber (3); or comprising method steps corresponding to features of the device (1), the system (10), or the cleaning device (20, 30) according to at least one of the preceding claims.

16. A computer program comprising instructions which, when executed by a computer, cause the computer to carry out a method according to the preceding claim.

17. A data carrier signal transmitting the computer program according to the preceding claim.

18. A computer-readable medium comprising instructions which, when executed by a computer, cause the computer to perform a method according to claim 15.

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