A magnetic flux leakage corrosion scanning apparatus and signal processing method

Abstract

The application discloses a kind of magnetic flux leakage corrosion scanning device and signal processing method, including detection unit and signal processing unit;The detection unit includes sequentially connected first detection unit, second detection unit and third detection unit;The detection unit includes motion module, magnetization module and detection module;The motion module structure of the first detection unit and third detection unit is identical, to realize the axial motion of device;The motion module of the second detection module is used to realize the axial and circumferential motion of device;The magnetization module is used to realize the local magnetization of detection pipeline;The detection module is used to detect the magnetic flux leakage signal of pipeline;The signal processing unit is used to store the signal collected by the detection module of detection unit.The device of the application can realize the detection of pipeline with a diameter greater than 89mm, realize circumferential motion without detaching the pipeline, and solve the problem of difficult equipment handling and complex detection process caused by large suction of permanent magnet excitation mode.

Description

Technical Field

[0001] This invention relates to the field of nondestructive testing technology, specifically to a magnetic flux leakage corrosion scanning device and a signal processing method. Background Technology

[0002] During long-term service, pipelines are prone to various corrosion defects caused by fluid erosion, chemical corrosion, and electrochemical corrosion. If these defects are not detected in time, they can lead to pipeline punctures and leaks, causing serious economic losses and safety accidents. Therefore, regular inspection and maintenance of pipelines are essential.

[0003] Magnetic flux leakage (MFL) testing, a common non-destructive testing (NDT) technique, is widely used for defect detection in ferromagnetic pipes. When a material is magnetized, the magnetic resistance at the defect increases, causing distortion of the magnetic field lines. Some of these lines leak to the material surface, creating a magnetic flux leakage field. This leakage field information can be picked up using a magnetically sensitive element, and the collected signals can be analyzed and processed to ultimately detect and evaluate the defect. The defect signal intensity obtained using MFL testing is related to the magnetization intensity; a higher magnetization intensity is often required to obtain a high signal-to-noise ratio MFL signal. Known scanners, such as "A Variable Diameter Pipe External Wall MFL Detection Device" (CN107632063A), are extremely difficult to remove from pipes due to the strong magnetism of their magnetized structures. External scanners typically only cover a partial fan-shaped area of ​​the pipe. To achieve full coverage detection, the external scanner needs to be repeatedly removed to change the corresponding scanning area. Therefore, traditional scanners are difficult to operate, involve a complex process, and are inefficient. As described in "A Box-type Automatic Scanner for Electromagnetic Ultrasonic Flaw Detection" (CN203941138U), the probe assembly of this type of scanner is difficult to disassemble separately. The lifting of the probe will change after the pipe diameter is changed, which will affect the stability of the probe's signal acquisition. In addition, the probe is also prone to wear during handling, and may even be bumped, causing damage to the probe assembly and destroying the internal structure of the probe.

[0004] Therefore, there is an urgent need to develop a pipe external leakage magnetic corrosion scanning device that is easy to handle, covers a wide range of pipe diameters, and allows for easy probe disassembly. Summary of the Invention

[0005] To address the above problems, this invention provides a magnetic flux leakage corrosion scanning device and a signal processing method.

[0006] The present invention adopts the following technical solution:

[0007] A magnetic flux leakage corrosion scanning device includes a detection unit and a signal processing unit. The detection unit comprises a first detection unit, a second detection unit, and a third detection unit connected sequentially by hinges. Each of the first, second, and third detection units includes a motion module, a magnetization module, and a detection module. The motion modules of the first and third detection units have identical structures and are used to achieve axial movement of the device. The motion module of the second detection unit is used to achieve axial and circumferential movement of the device. The magnetization module is used to achieve local magnetization of the detected pipeline. The detection module is used to detect the magnetic flux leakage signal of the pipeline. The signal processing unit is used to store the signals collected by the detection modules of the first, second, and third detection units.

[0008] Furthermore, the motion module of the first detection unit includes a first V-shaped wheel, which is fixed to the lower part of a first wheel frame, and the first wheel frame is connected to a first crossbeam.

[0009] Furthermore, the motion module of the second detection unit includes a second V-shaped wheel, which is fixed to the lower part of the second wheel frame, and the second wheel frame is connected to the second crossbeam;

[0010] It also includes a universal ball, which is fixed to the lower end of the boss; the boss is slidably connected to the slotted bracket and connected to the crossbeam through a tension spring, always maintaining contact with the cam; the cam is fixed to the second crossbeam through a connecting shaft and connected to the handle.

[0011] Furthermore, the boss is made of brass, which has good wear resistance.

[0012] Furthermore, the magnetization module includes an armature, a permanent magnet, and pole shoes; the armature, permanent magnet, and pole shoes are connected by a back plate.

[0013] Furthermore, the signal processing unit is placed in a signal box, which is fixed to the second detection unit by an L-shaped bracket.

[0014] Furthermore, the signal box is equipped with a data transmission antenna on its upper part, and a signal processing PCB board and a power supply are installed inside.

[0015] Furthermore, the detection module includes a probe, which is disposed within a probe housing.

[0016] Furthermore, the probe is composed of a Hall sensor array along an arc.

[0017] In another aspect, the present invention provides a signal processing method for a magnetic flux leakage corrosion scanning device, which, based on the above-mentioned magnetic flux leakage corrosion scanning device, includes the following steps:

[0018] S1. Ensure the magnetic flux leakage corrosion scanning device is fully fitted to the pipeline;

[0019] S2. Calibrate the device and set the sampling method and related parameters;

[0020] S4. To create a new sample, position the handle of the second detection unit in a vertical position, lift the universal ball under the action of the tension spring, and push the handle to make the device move forward at a constant speed.

[0021] S5. Suspend testing;

[0022] S6. Press the handle of the second detection unit to lift the second detection unit away, the V-shaped wheel will disengage from the pipe, and the universal ball will adhere to the pipe;

[0023] S7. Close the two side units together and push the handle to make the device move circumferentially along the pipe under the action of the universal ball until it reaches the detection angle.

[0024] S8. Continue testing, return the handle of the second testing unit to the vertical position, and push the handle to make the device move forward at a constant speed.

[0025] S9. Stop detection, open stored data, and display the specific location of the defect.

[0026] The beneficial effects of this invention are:

[0027] 1. Simplified operation, expanded application scope, and optimized data transmission make it well-suited for external corrosion detection of pipes with multiple diameters.

[0028] 2. The present invention designs a lifting mechanism mainly composed of universal ball bearings and cams, which realizes easy picking up of the device and at the same time realizes circumferential movement.

[0029] 3. The detection unit of the present invention adopts a modular design, which is divided into a motion module, a magnetization module and a detection module. It can be assembled and disassembled separately, reducing maintenance costs, especially reducing the replacement cost of the probe. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0031] Figure 1 This is a schematic diagram of the overall structure of the magnetic flux leakage corrosion scanning device of the present invention;

[0032] Figure 2 This is a side view schematic diagram of the magnetic flux leakage corrosion scanning device of the present invention inspecting an 89mm pipe;

[0033] Figure 3This is a side view of the detection plate (infinite diameter) of the magnetic flux leakage corrosion scanning device of the present invention;

[0034] Figure 4 This is a view of the second detection unit of the magnetic flux leakage corrosion scanning device of the present invention during detection;

[0035] Figure 5 This is a view of the second detection unit of the magnetic flux leakage corrosion scanning device of the present invention during circumferential movement;

[0036] Figure 6 This is a schematic diagram of the magnetization structure and magnetic circuit of the magnetic flux leakage corrosion scanning device of the present invention;

[0037] Figure 7 This is a schematic diagram of the detection module of the magnetic flux leakage corrosion scanning device of the present invention;

[0038] Figure 8 This is a schematic diagram of the signal box and signal processing unit of the present invention;

[0039] In the diagram: 1-First detection unit, 2-Second detection unit, 3-Third detection unit, 4-Hinge, 5-Signal box, 6-Encoder, 7-Pipe, 11-First V-wheel, 12-Second wheel frame, 13-Wheel cover, 14-Armature, 15-Permanent magnet, 16-Pole shoe, 17-Screw, 18-Probe box, 19-Back sheet, 22-Universal ball, 23-L-shaped bracket, 24-Bracket, 25-Boss, 26-Cam, 27-Tension spring, 28-Connecting shaft, 52-Antenna, 53-Probe, 101-First crossbeam, 201-Second crossbeam, 202-Handle, 502-Signal processing PCB board, 503-Power supply Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0041] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0042] like Figures 1 to 8 As shown, a magnetic flux leakage corrosion detection device is used to detect pipeline defects. The device includes a detection unit and a signal processing unit. The detection unit comprises a first detection unit 1, a second detection unit 2, and a third detection unit 3 connected sequentially by a hinge 4. Figure 2 and Figure 3As shown, by adjusting the opening angle of hinge 4, it is applicable to all pipes with a diameter greater than 89mm; the first detection unit 1, the second detection unit 2, and the third detection unit 3 each include a motion module, a magnetization module, and a detection module; an encoder 6 is provided on the first detection unit 1, and the sampling type can be set via PC, such as equal-time sampling or equal-distance sampling; the motion modules of the first detection unit 1 and the third detection unit 3 have the same structure, which is used to realize the axial movement of the device; the motion module of the first detection unit 1 includes a first V-shaped wheel 11, which is fixed to the lower part of the first wheel frame by a wheel cover 13, and the first wheel frame is connected to the first crossbeam 101; the V-shaped wheel can not only walk on the flat plate, but also rotate smoothly on the pipe. With the three sets of V-shaped wheels, the circumferential positioning of the device can be realized, ensuring that the detection device always moves in a straight line without deviation during the movement.

[0043] The motion module of the second detection module 2 is used to realize the axial and circumferential movement of the device. The motion module of the second detection unit includes a second V-shaped wheel, which is fixed to the lower part of the second wheel frame 12 and connected to the second crossbeam 201. It also includes a universal ball 22, which is fixed to the lower end of the boss 25. The boss 25 is made of brass and has good wear resistance. The boss 25 is slidably connected to the slotted bracket 24 and connected to the crossbeam 201 through the tension spring 27, always maintaining contact with the cam 26. The cam 26 is fixed to the second crossbeam 201 through the connecting shaft 28 and connected to the handle 202. When the handle 202 is in a horizontal position, the cam 26 applies force to the universal ball 22 through the boss 25, lifting the second detection unit away and reducing the interaction force between the permanent magnet 15 and the pipe 7. After the three detection units are closed, the first and third detection units on both sides are separated from the pipe 7, the interaction force between the device and the pipe is reduced, and the circumferential movement of the device is realized under the action of the motion module of the second detection unit.

[0044] The magnetization module is used to achieve local magnetization of the detection pipeline; the magnetization module includes an armature 14, a permanent magnet 15 and a pole shoe 16; the armature 14, the permanent magnet 15 and the pole shoe 16 are connected by a back plate 19; the permanent magnet of the magnetization module is located between the pole shoe and the armature, forming a closed magnetic circuit together with the pipeline.

[0045] The detection module is used to detect the magnetic leakage signal of the pipeline; the detection module includes a probe 53, which is set in a probe box 18. The probe box 18 is connected to the second crossbeam 201 by a screw 17, which is easy to disassemble; the probe 53 is composed of Hall sensors arranged in an arc array. The Hall sensors can collect the magnetic leakage signal and transmit it to the signal processing unit in the signal box 5 through a transmission line.

[0046] The signal processing unit is used to store the signals collected by the detection modules in the first detection unit 1, the second detection unit 2, and the third detection unit 3; the signal processing unit is placed in the signal box 5, and the signal box 5 is fixed to the second detection unit 2 by an L-shaped bracket 23; the upper part of the signal box 5 is provided with a data transmission antenna 52, and the inside is provided with a signal processing PCB board 502 and a power supply 503.

[0047] A signal processing method using the above-mentioned magnetic flux leakage corrosion scanning device includes the following steps:

[0048] S1. Ensure the magnetic flux leakage corrosion scanning device is fully fitted to the pipeline;

[0049] S2. Calibrate the device and set the sampling method and related parameters;

[0050] S4. To create a new sample, position the handle of the second detection unit in a vertical position, lift the universal ball under the action of the tension spring, and push the handle to make the device move forward at a constant speed.

[0051] S5. Suspend testing;

[0052] S6. Press the handle of the second detection unit to lift the second detection unit away, the V-shaped wheel will disengage from the pipe, and the universal ball will adhere to the pipe;

[0053] S7. Close the two side units together and push the handle to make the device move circumferentially along the pipe under the action of the universal ball until it reaches the detection angle.

[0054] S8. Continue testing, return the handle of the second testing unit to the vertical position, and push the handle to make the device move forward at a constant speed.

[0055] S9. Stop detection, open stored data, and display the specific location of the defect.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A magnetic flux leakage corrosion scanning device, characterized in that, The magnetic flux leakage corrosion scanning device includes a detection unit and a signal processing unit; The detection unit includes a first detection unit (1), a second detection unit (2) and a third detection unit (3) connected in sequence by a hinge (4); The first detection unit (1), the second detection unit (2), and the third detection unit (3) each include a motion module, a magnetization module, and a detection module; The motion module structures of the first detection unit (1) and the third detection unit (3) are the same, and are used to realize the axial movement of the device; the motion module of the second detection unit (2) is used to realize the axial and circumferential movement of the device; The magnetization module is used to achieve local magnetization of the detection pipeline; The detection module is used to detect the magnetic flux leakage signal of the pipeline; The signal processing unit is used to store the signals collected by the detection modules in the first detection unit (1), the second detection unit (2), and the third detection unit (3); The motion module of the second detection unit includes a second V-shaped wheel, which is fixed to the lower part of the second wheel frame (12), and the second wheel frame (12) is connected to the second crossbeam (201); It also includes a universal ball (22), which is fixed to the lower end of the boss (25); The boss (25) is slidably connected to the slotted bracket (24) and connected to the crossbeam (201) through the tension spring (27), and always maintains contact with the cam (26); The cam (26) is fixed to the second crossbeam (201) via a connecting shaft (28) and connected to the handle (202); The boss (25) is made of brass; The detection module includes a probe (53), which is disposed inside a probe box (18); The probe (53) is composed of a Hall sensor array along an arc.

2. The magnetic flux leakage corrosion scanning device according to claim 1, characterized in that, The motion module of the first detection unit (1) includes a first V-shaped wheel (11), which is fixed to the lower part of the first wheel frame and connected to the first crossbeam (101).

3. The magnetic flux leakage corrosion scanning device according to claim 1, characterized in that, The magnetization module includes an armature (14), a permanent magnet (15), and a pole shoe (16). The armature (14), permanent magnet (15) and pole shoe (16) are connected by a back piece (19).

4. The magnetic flux leakage corrosion scanning device according to claim 1, characterized in that, The signal processing unit is placed in the signal box (5), and the signal box (5) is fixed to the second detection unit (2) by an L-shaped bracket (23).

5. The magnetic flux leakage corrosion scanning device according to claim 4, characterized in that, The signal box (5) is equipped with a data transmission antenna (52) on the upper part and a signal processing PCB board (502) and a power supply (503) inside.

6. A signal processing method for a magnetic flux leakage corrosion scanning device, using the magnetic flux leakage corrosion scanning device according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Ensure the magnetic flux leakage corrosion scanning device is fully fitted to the pipeline; S2. Calibrate the device and set the sampling method and related parameters; S4. To create a new sample, position the handle of the second detection unit in a vertical position, lift the universal ball under the action of the tension spring, and push the handle to make the device move forward at a constant speed. S5. Suspend testing; S6. Press the handle of the second detection unit to lift the second detection unit away, the V-shaped wheel will disengage from the pipe, and the universal ball will adhere to the pipe; S7. Close the two units together and push the handle to make the device move along the circumference of the pipe under the action of the universal ball until it reaches the detection angle. S8. Continue testing, return the handle of the second testing unit to the vertical position, and push the handle to make the device move forward at a constant speed. S9. Stop detection, open stored data, and display the specific location of the defect.

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