Pipeline magnetic flux leakage internal detector probe with magnetic conductive device

Abstract

The utility model discloses a pipeline magnetic flux leakage internal detector probe with a magnetic conductive device, which relates to the technical field of pipeline internal detection and comprises a probe shell, the magnetic conductive device, a detection sensor and a probe circuit board, the probe circuit board is mounted in the probe shell, the detection sensor is mounted on the probe circuit board, and the magnetic conductive device is mounted in the probe shell. The magnetic conduction device is installed in the probe shell, a leakage magnetic field of a pipeline can be conducted to the position near the detection sensor through the magnetic conduction device, the leakage magnetic field is conducted through the magnetic conduction device, and the problem that the detection sensor cannot pick up the leakage magnetic field near the surface of the pipe wall is solved. The adverse effect caused by the lift-off effect of the detection sensor is reduced, so that a leakage magnetic field generated by defects near the detection sensor and a leakage magnetic field conducted by the magnetic conductive device are mutually superposed, the signal intensity of the leakage magnetic field near the detection sensor is increased, and the sensitivity of the detector probe is improved; and the defect detection capability of the detector in the pipeline can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of in-pipe detection, in particular to a magnetic flux leakage in-pipe detector probe with a magnetic conduction device. Background Art

[0002] During the operation of pipelines, various defects will occur due to corrosion, geological movement, mechanical damage, self-defects, etc. These defects will have an adverse impact on the safe operation of pipelines. It is of great significance to detect and track pipeline defects. Usually, in-pipe detectors are used to detect pipeline defects, and among them, in-pipe detectors using magnetic flux leakage detection technology are the most widely used.

[0003] The basic principle of magnetic flux leakage detection technology is: magnetize the pipeline through an excitation device to make the pipe wall in a stable magnetization state. Most of the formed magnetic field is confined inside the pipe wall, and a part of the magnetic field leaks to the outside of the pipe wall to form a magnetic flux leakage field. At the normal pipe wall, the magnetic flux leakage field basically remains constant. At the location where there are defects in the pipeline, the magnetic field confined inside the pipe wall will leak to the outside of the pipe wall near the pipeline defects, resulting in a change in the intensity of the magnetic flux leakage field outside the pipe wall. The detection of pipeline defects is realized by measuring the intensity of the magnetic flux leakage field and analyzing the change law of the magnetic flux leakage field.

[0004] The magnetic flux leakage field at the pipeline defect has a certain distribution law. One of the laws is that the closer the position is to the pipe wall surface, the more obvious the change in the intensity of the magnetic flux leakage field. Away from the pipeline surface, the change in the intensity of the magnetic flux leakage field will gradually weaken with the increase of the distance. The smaller the defect, the faster the weakening speed of the intensity change. The distance between the above measurement position and the pipe wall is the lift-off value, and the phenomenon that the change intensity of the magnetic flux leakage field weakens with the increase of the lift-off value is the lift-off effect of the magnetic flux leakage field.

[0005] The more obvious the actual picked-up change in the magnetic flux leakage field is, the more beneficial it is to the identification and analysis of pipeline defects. Combining the above lift-off effect of the magnetic flux leakage field, this means that reducing the lift-off value of the detector probe and making the sensitive area of the detection sensor as close to the pipe wall surface as possible can pick up a more obvious magnetic flux leakage field, which is then beneficial to improving the detection ability of pipeline defects.

[0006] However, in order to ensure that the detector probe has sufficient mechanical strength and wear resistance, the probe housing needs to have a certain thickness. At the same time, the packaging housing of the detection sensor also has a certain thickness, and the lift-off value cannot be directly reduced. Taking the commonly used HAL815 Hall sensor in the existing in-pipe detector probe as an example, the lift-off value between the sensitive area of the sensor and the pipe wall surface is about 3 to 4 mm. At this lift-off value, as Figures 1-2 shown, for conventional corrosion defects of pipelines, there is a certain attenuation in the picked-up magnetic flux leakage field. For small defects such as pinholes and crack-like defects, the picked-up magnetic flux leakage field is relatively weak, and the above small defects cannot be effectively detected. Content of the Utility Model

[0007] The utility model aims to at least solve the problems existing in the prior art that the lift-off value of the probe of the in-pipe detector cannot be directly reduced, affected by the lift-off effect, for conventional corrosion defects of the pipeline, there is a certain attenuation of the detected leakage magnetic field, and for small defects such as pinholes and crack-like defects, the detected leakage magnetic field is weak and the above small defects cannot be effectively detected.

[0008] The present solution provides a magnetic flux leakage in-pipe detector probe with a magnetic conduction device, which is achieved by the following specific technical means: including a probe housing, a magnetic conduction device, a detection sensor, and a probe circuit board. The probe circuit board is fixed inside the probe housing, and at the same time, the detection sensor is fixedly installed on the probe circuit board. The magnetic conduction device is fixedly installed inside the upper part of the probe housing and is located near the detection sensor. One end of the magnetic conduction device is close to the inner wall of the pipeline to be detected, and the other end is close to the detection sensor. The leakage magnetic field of the pipeline is conducted to the vicinity of the detection sensor through the magnetic conduction device.

[0009] As a preferred technical solution, holes are opened on the probe housing. One end of the magnetic conduction device passes through the holes on the probe housing and contacts the inner wall of the pipeline. Through the contact between the magnetic conduction device and the inner wall of the pipeline, the magnetic conduction device can conduct as much leakage magnetic field at the defective part of the pipeline as possible to the vicinity of the detection sensor, increasing the amplitude and intensity change of the leakage magnetic field signal that the detection sensor can pick up.

[0010] As a preferred technical solution, it further includes multiple groups of probe wear-resistant bodies fixedly installed on the probe housing. The probe housing contacts the pipe wall surface through the probe wear-resistant bodies. The material of the probe wear-resistant bodies is ceramic, carbide, nitride, or wear-resistant steel. One group of the probe wear-resistant bodies is a probe wear-resistant body with holes, and one end of the magnetic conduction device can pass through the holes on the probe wear-resistant body and contact the inner wall of the pipeline.

[0011] As a preferred technical solution, the magnetic conduction device is made of soft magnetic materials such as ferrite, silicon steel, and permalloy.

[0012] As a preferred technical solution, the surface of the probe housing is sprayed or welded with wear-resistant materials. By spraying or welding wear-resistant materials on the surface of the probe housing, the wear resistance of the probe housing can be increased, the wear of the probe housing by dirt in the pipeline can be alleviated, and the service life of the probe can be improved.

[0013] As a preferred technical solution, the detection sensor is connected to the probe circuit board by means of surface mounting, through-hole assembly, or lead connection.

[0014] As a preferred technical solution, the probe circuit board and the detection sensor are sealed in the probe housing by potting glue. By using potting glue to seal the probe circuit board and the detection sensor, the durability and service life of the probe can be improved.

[0015] As a preferred technical solution, the detection sensor is a magnetic sensor or an electromagnetic sensor.

[0016] Adopting the above structure enables this solution to have the following beneficial effects:

[0017] 1. Through the magnetic conduction device, the leakage magnetic field on the pipe wall surface and at the pipe defect can be conducted to the vicinity of the detection sensor, increasing the amplitude and intensity change of the leakage magnetic field signal that the detection sensor can pick up. It solves the problem that for the existing in-pipe detector probe of pipelines, due to the inability to directly reduce the lift-off value, under the influence of the lift-off effect, for conventional corrosion defects of pipelines, the picked-up leakage magnetic field signal attenuates. At the same time, it also solves the problem that for the existing in-pipe detector probe of pipelines, due to the inability to directly reduce the lift-off value, under the influence of the lift-off effect, for small defects such as pinholes and crack-like defects, the picked-up leakage magnetic field signal is weak and cannot effectively detect the above small defects.

[0018] 2. By using the probe wear-resistant body, the wear resistance of the probe housing is improved, which can effectively protect the probe shell and the sensor inside the probe shell, and improve the service life of the probe. By opening holes in the probe wear-resistant body, one end of the magnetic conduction device can pass through the holes in the probe wear-resistant body to contact the inner wall of the pipe. Through the contact between the magnetic conduction device and the inner wall of the pipe, the magnetic conduction device can conduct as much leakage magnetic field at the pipe defect to the vicinity of the detection sensor as possible, increasing the amplitude and intensity change of the leakage magnetic field signal that the detection sensor can pick up.

[0019] 3. By using potting glue to seal the probe circuit board and the detection sensor in the probe housing, the contact between the probe circuit board and the detection sensor and the external environment can be isolated, increasing the anti-corrosion, anti-fouling and anti-short-circuit capabilities, and also helping to improve the overall mechanical strength of the probe, improving the durability and service life of the probe.

[0020] 4. By using different types of magnetic sensors or electromagnetic sensors, pipelines with different diameters and wall thicknesses can be detected under different magnetization intensities, which helps to obtain pipeline detection data more comprehensively and accurately, and helps to obtain more detailed and accurate detection results. Description of the Drawings

[0021] The drawings are used to provide a further understanding of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation to the present invention. In the drawings:

[0022] Figure 1 is a schematic diagram of the existing in-pipe detector probe detecting conventional corrosion defects;

[0023] Figure 2 is a schematic diagram of the existing in-pipe detector probe detecting small defects;

[0024] Figure 3 is a schematic diagram of the probe of the embodiment of the present application detecting small defects;

[0025] Figure 4 is a top view schematic diagram of the probe of the embodiment of the present application.

[0026] Among them, 01 is the probe housing; 02 is the probe circuit board; 03 is the probe wear-resistant body; 04 is the detection sensor; 05 is the sensitive area of the detection sensor; 06 is the pipe wall; 07 is the conventional corrosion defect of the pipeline; 08 is the leakage magnetic field of the conventional corrosion defect of the pipeline; 09 is the sensor lift-off value; 10 is the excitation magnetic field; 11 is the small defect of the pipeline; 12 is the leakage magnetic field of the small defect of the pipeline; 13 is the magnetic conduction device; 14 is the leakage magnetic field of the small defect of the pipeline under the action of the magnetic conduction device; 15 is the probe wear-resistant body with holes. Specific embodiments

[0027] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments; based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0028] Please refer to Figure 3 , the magnetic flux leakage in-pipe detector probe with a magnetic conduction device includes a probe housing 01, a probe circuit board 02, a probe wear-resistant body 03, a detection sensor 04, a magnetic conduction device 13 and a probe wear-resistant body 15 with holes.

[0029] In the embodiment, the probe housing 01 is installed on the in-pipe detector. The probe housing 01 is made of stainless steel and is manufactured by machining. There are 4 probe wear-resistant bodies 03 in total, which are cylindrical ceramic cylinders. The top edge is chamfered. The probe wear-resistant bodies 03 are embedded in the corresponding hole positions on the probe housing 01 and are fixed by an adhesive;

[0030] There is 1 probe wear-resistant body 15 with holes in total, which is a rounded rectangular ceramic sheet. The top edge is chamfered. The probe wear-resistant body 15 with holes is processed with holes for the magnetic conduction device 13 fixed in the probe housing 01 to pass through. The probe wear-resistant body 15 with holes is embedded in the corresponding installation position on the probe housing 01 and is also fixed by an adhesive;

[0031] The surface of the probe housing 01 is spray-welded or sprayed with wear-resistant material;

[0032] There are 5 groups of magnetic conduction devices 13, which are made of silicon steel. One end of the magnetic conduction device 13 is closely attached to the detection sensor 04, and the other end passes through the hole on the probe wear-resistant body 15 with holes;

[0033] The detection sensor 04 is a HAL815 Hall effect magnetic sensor, with a total of 5 pieces, and is installed on the fixed probe circuit board 02 in the probe housing 01 by means of through-hole assembly and welding;

[0034] The probe circuit board 02, the detection sensor 04 and the magnetic conduction device 13 are combined and installed at the corresponding positions in the probe housing 01, and the remaining space in the probe housing 01 is potted with an oxygen resin-based potting adhesive.

[0035] Refer to Figure 4 , the top view schematic diagram of the pipeline magnetic flux leakage internal detector probe with a magnetic conduction device in the embodiment. In the figure, the probe housing 01, the probe wear-resistant body 03, the magnetic conduction device 13 and the probe wear-resistant body 15 with holes can be seen.

[0036] The working principle and process of the embodiment are as follows:

[0037] The pipeline magnetic flux leakage internal detector probe with a magnetic conduction device runs forward closely along the inner surface of the pipeline wall 06 under the drive of the operation of the pipeline internal detector in the embodiment. During the running process, the probe housing 01 contacts the pipeline wall 06 through the probe wear-resistant body 03 to prevent the probe housing 01 from being worn. The probe wear-resistant body 15 with holes installed on the probe housing 01 protects the detection sensor 04 and the magnetic conduction device 13 installed in the probe housing 01 to prevent the detection sensor 04 from being damaged and the magnetic conduction device 13 from being excessively worn;

[0038] When the pipeline magnetic flux leakage internal detector probe of the embodiment runs to the position of the pipeline conventional corrosion defect 07 on the pipeline wall 06, under the action of the excitation magnetic field 10 of the pipeline internal detector, a magnetic flux leakage field will be generated at the pipeline defect. The magnetic conduction device 13 has a conduction and convergence effect on the magnetic flux leakage field 08 of the pipeline conventional corrosion defect. The magnetic flux leakage field is conducted to the position near the detection sensor 04 through the magnetic conduction device 13, so that the magnetic flux leakage field generated by the defect itself at the sensitive area 05 of the detection sensor and the magnetic flux leakage field conducted by the magnetic conduction device 13 are superimposed on each other, enabling the detection sensor 04 to pick up the magnetic flux leakage field 08 signal of the pipeline conventional corrosion defect with a more significant intensity change and improving the detection ability of the detection sensor 04 for the pipeline conventional corrosion defect 07.

[0039] When the magnetic flux leakage internal detector probe of the pipeline with a magnetic conduction device in the embodiment runs to a small pipeline defect 11 such as a pinhole or a crack-like defect on the pipeline wall 06, under the action of the excitation magnetic field 10 of the pipeline internal detector, a magnetic flux leakage field 12 of the small pipeline defect will be generated at the pipeline defect. The magnetic flux leakage signal generated by the small defect itself is weak, and the magnetic flux leakage decays significantly as the sensor lift-off value 09 increases. It is very difficult to be directly picked up by the detection sensor 04 with a certain lift-off value. The detection sensor 04 cannot pick up the magnetic flux leakage signal generated by the defect itself. In this solution, since the magnetic conduction device 13 has a conduction and convergence effect on the magnetic flux leakage field at the defect, the magnetic conduction device 13 can converge and conduct the weak magnetic flux leakage signal at small defects such as pinholes or crack-like defects to the vicinity of the sensitive area 05 of the detection sensor, so that the detection sensor 04 can pick up the magnetic flux leakage field 14 signal of the small pipeline defect under the action of the magnetic conduction device, thereby realizing the detection of small defects such as pinholes or crack-like defects.

[0040] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A magnetic flux leakage internal detector probe for pipelines with a magnetic conduction device, comprising a probe housing (01), characterized in that: A detection sensor (04), a probe circuit board (02) and a magnetic conduction device (13) are installed in the probe housing (01). The detection sensor (04) is installed on the probe circuit board (02). The magnetic conduction device (13) is installed near the detection sensor (04). One end of the magnetic conduction device (13) is close to the pipe wall (06) to be detected, and the other end is close to the detection sensor (04). The leakage magnetic field of the pipeline is conducted to the vicinity of the detection sensor (04) through the magnetic conduction device (13).

2. The magnetic flux leakage internal detector probe for pipeline with a magnetic conduction device (13) according to claim 1, characterized in that: At least one set of the multiple groups of probe housings (01) is provided with holes, and one end of the magnetic conduction device (13) can pass through the holes on the probe housing (01) to contact the pipe wall (06).

3. The magnetic flux leakage internal detector probe for pipelines with a magnetic conduction device according to claim 2, characterized in that: It further includes a probe wear-resistant body (03). The probe wear-resistant body (03) is installed on the probe housing (01). The probe housing (01) contacts the surface of the pipe wall (06) through the probe wear-resistant body (03). The material of the probe wear-resistant body (03) is ceramic, carbide, nitride or wear-resistant steel. At least one set of the multiple groups of probe wear-resistant bodies (03) is provided with holes, and one end of the magnetic conduction device (13) can pass through the holes on the probe wear-resistant body (03) to contact the pipe wall (06).

4. The magnetic flux leakage internal detector probe for pipelines with a magnetic conduction device according to claim 1, characterized in that: The magnetic conduction device (13) is made of ferrite, silicon steel or permalloy soft magnetic material.

5. The magnetic flux leakage internal detector probe for pipeline with a magnetic conduction device according to claim 1, characterized in that: The surface of the probe housing (01) is sprayed or welded with wear-resistant material.

6. The magnetic flux leakage internal detector probe for pipeline with a magnetic conduction device according to claim 1, characterized in that: The detection sensor (04) is connected to the probe circuit board (02) by means of surface mounting, through-hole assembly or lead connection.

7. A magnetic flux leakage internal detector probe for a pipeline with a magnetic conduction device according to claim 1, characterized in that: The probe circuit board (02), the detection sensor (04) and the magnetic conduction device (13) are sealed in the probe housing (01) by potting glue.

8. The magnetic flux leakage internal detector probe for pipeline with a magnetic conduction device according to claim 1, characterized in that: The detection sensor (04) is a magnetic sensor or an electromagnetic sensor.

Images