Nondestructive testing device for defects of inner coating of pipeline

Abstract

The invention discloses a nondestructive testing device for defects of a coating in a pipeline, and relates to the technical field of fluorescence detection. The device comprises a light guide transparent pipe provided with an atomization nozzle, a disposable plug (with a plastic film), a pipe joint (integrated with an ultraviolet generation assembly) and a crawl type information receiving part (comprising three 120-degree wide-angle cameras, an extrusion roller, a driving motor and a centering supporting arm). During detection, firstly pumping a washing type fluorescent penetrant to uniformly spray an inner coating, breaking a membrane by high-pressure gas to clean residual liquid, and then washing with clear water to retain a fluorescent agent in a defect; and then the receiving part is inserted to crawl along the tube, the ultraviolet light uniformly illuminates the whole inner wall through the light guide tube, the camera captures 360-degree fluorescence images in real time, and the defect is judged through the contour brightness. The device is compact in structure, simple and convenient to operate, comprehensive and accurate in detection and suitable for nondestructive detection of coatings in various industrial pipelines.

Description

Technical Field

[0001] This invention relates to the field of fluorescence detection technology, specifically to a non-destructive testing device for defects in the inner coating of pipes. Background Technology

[0002] In existing technologies, non-destructive testing of coating defects inside pipes mainly relies on manual endoscopes combined with manual spraying of fluorescent penetrant. The process requires opening one end of the pipe, with a worker inserting a spray gun or brush to apply the penetrant to the inner wall. Due to the long length and narrow space of the pipe, even spraying is difficult, easily resulting in missed areas or build-up. Subsequent manual wiping or simple rinsing is then required, a very cumbersome process. During testing, only a handheld UV lamp can be used for localized irradiation, and the endoscope probe needs to be repeatedly advanced and rotated, making 360° continuous coverage difficult. Furthermore, the equipment is prone to eccentricity and jamming inside the pipe, hindering stable movement. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, the present invention provides the following technical solution: a non-destructive testing device for defects in the inner coating of a pipe, comprising an information receiving unit mounted on a support assembly, the information receiving unit being capable of crawling on the surface of a light-guiding transparent tube, multiple atomizing nozzles being evenly arranged on the circumferential surface of the light-guiding transparent tube, all of which are connected to the internal space of the light-guiding transparent tube, a plug head being fixed at one end of the light-guiding transparent tube in a manner that is easy to disassemble, and a plastic film being provided at the axial position of the plug head; a pipe joint being fixed at the other end of the light-guiding transparent tube in a manner that is easy to disassemble, the pipe joint being used to connect to the exhaust port of an air pump or the outlet of a liquid pump, an ultraviolet generating component being embedded inside the pipe joint, the end face of the ultraviolet generating component being fitted and aligned with the end face of the light-guiding transparent tube. Multiple ultraviolet lamp beads are disposed inside the ultraviolet generating component, the lamp beads focusing ultraviolet light onto the end face of the light-guiding transparent tube through a lamp cup; the information receiving unit includes a cylindrical carrier capable of axial movement on the surface of the light-guiding transparent tube, three wide-angle cameras being disposed on the circumferential surface of the cylindrical carrier, the three wide-angle cameras being distributed at 120° intervals on the cylindrical carrier.

[0004] Preferably, the information receiving unit further includes a square shell for fixing the cylindrical carrier. Two extrusion roller support plates are fixedly installed inside the square shell. Each extrusion roller support plate has two symmetrically formed support slider grooves, and a support slider is slidably installed in each support slider groove. Between the opposing surfaces of the two extrusion roller support plates, two extrusion rollers with parallel axes and rolling contact with the surface of the light guide tube are also provided. The two extrusion rollers are rotatably mounted on their respective support sliders via two drive shafts. The extrusion rollers are fixedly engaged with the drive shafts, and both ends of the drive shafts are rotatably engaged with the two support sliders. The support sliders can only slide within their support slider grooves and have no rotational freedom.

[0005] Preferably, an elastic rope fixing frame is fixed to the middle of the opposite sides of both extrusion roller support plates, and a collar bearing is rotatably fitted at both ends of each drive shaft. All collar bearings are elastically connected to the elastic rope fixing frame via elastic ropes. A cover is fixed to each extrusion roller support plate. The cover is used to fasten the collar bearing, elastic rope fixing frame, and elastic rope to the extrusion roller support plate. The cover also has a slot for allowing the drive shaft to move linearly, preventing obstruction of the drive shaft's movement.

[0006] Preferably, the square shell also has two drive motor sliding slots, and a drive motor is slidably installed in each of the two drive motor sliding slots. The output shafts of the two drive motors are coaxially and fixedly connected to the two drive shafts respectively. The housing of the drive motor slides linearly inside the drive motor sliding slot, and the housing of the drive motor and the drive motor sliding slot have no rotational degree of freedom.

[0007] Preferably, two paddle plates are also slidably installed on the square shell. The two paddle plates are located on the side of the square shell where the drive motor sliding groove is opened, and the two paddle plates are respectively fixed to the outer shell of the two drive motors.

[0008] Preferably, the support assembly includes an outer protective frame fixed to the square shell, the square shell being fixed to the inner side of the outer protective frame, and at least three centering support arms being movably mounted on the circumferential surface of the outer protective frame.

[0009] Preferably, each centering support arm includes two symmetrically arranged swing arms, one end of which is movably connected to the outer protective frame via a hinge, and the other end of which is rotatably mounted with a support roller.

[0010] Preferably, each centering support arm further includes two spring telescopic rods fixed to the outer protective frame. The actuating rods of the two spring telescopic rods are fixed to the synchronous beam rod. Both ends of the synchronous beam rod are fixed with pins. Each swing arm has a sliding guide rail, and the pins are slidably set in the sliding guide rail.

[0011] Compared with the prior art, the present invention has the following beneficial effects: (1) By uniformly setting multiple atomizing nozzles on the circumferential surface of the light-guiding transparent tube and connecting them with the internal space, and connecting the liquid pump with the pipe joint, the water-washable fluorescent penetrant can be uniformly atomized and sprayed onto the entire inner coating surface of the pipe, achieving full coverage and penetration treatment without dead angles. After the penetrant fully penetrates into the fine cracks or defects, high-pressure gas is injected by the air pump to break the plastic film and make the two ends conductive, thereby removing the residual penetrant in the pipe, avoiding the drawbacks of uneven manual spraying or excessive manual cleaning, greatly improving the detection sensitivity and reliability, especially suitable for accurate identification of inner coating defects in long-distance, closed industrial pipelines, significantly reducing the missed detection rate and false judgment rate, and providing reliable protection for the safe operation of the pipeline; (2) The information receiving unit adopts three wide-angle cameras evenly distributed at 120° on the cylindrical carrier, combined with the extrusion roller driven by two drive motors in the square shell and the elastic pull rope return mechanism, which can achieve stable axial crawling along the surface of the light-guiding transparent tube. At least three centering support arms on the outer protective frame ensure that the device automatically centers in the pipe without eccentric rolling through spring telescopic rods, synchronous beam rods and support rollers, avoiding jamming or shaking. The ultraviolet light emitted by the ultraviolet generating component is evenly transmitted to the entire pipe section through the light guide transparent tube, illuminating the inner coating, so that the residual fluorescent penetrant at the defect emits clear fluorescence, and the camera captures the image in real time at 360°, and directly judges the size and qualification of the defect by the shape and brightness of the fluorescent contour. It solves the problem that traditional probes cannot move stably and have many blind spots, and realizes full detection with one insertion; (3) The length of the light guide transparent tube of the present invention can be flexibly matched according to the pipe requirements. When inserting, the squeezing roller is manually separated by the paddle plate to facilitate pipe insertion. After releasing, the elastic pull rope automatically clamps; the centering support arm can be compressed and inserted by pressing the synchronous beam rod, and automatically springs open to fit the inner wall after releasing. It makes the equipment adaptable to different pipe diameters and lengths, and completes the entire process of spraying-cleaning-detection in one go. There is no need to disassemble and install the pipe or change tools multiple times, which significantly reduces the equipment cost and maintenance difficulty, while ensuring that the inner coating is not damaged during the detection process. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0013] Figure 2 This is a structural diagram of the supporting components of the present invention.

[0014] Figure 3 This is a diagram showing the installation location of the ultraviolet generating component of the present invention.

[0015] Figure 4 This is a structural diagram of the information receiving unit of the present invention.

[0016] Figure 5 This is a structural diagram of the extrusion roller of the present invention.

[0017] Figure 6This is a structural diagram of the sliding groove supporting the slider in this invention.

[0018] In the diagram: 101-Square shell; 102-Wide-angle camera; 103-Cylindrical carrier; 104-Paddle plate; 105-Drive motor sliding groove; 106-Drive motor; 107-Extrusion roller support plate; 108-Extrusion roller; 109-Cover; 110-Elastic pull rope fixing frame; 111-Elastic pull rope; 112-Drive shaft; 113-Collar bearing; 114-Support slider groove; 115-Support slider; 201-Light guide transparent tube; 202-Atomizing nozzle; 203-Plug head; 204-Plastic film; 205-Pipe connector; 206-UV generating component; 301-Outer protective frame; 302-Hinge; 303-Swing arm; 304-Synchronous beam rod; 305-Spring telescopic rod; 306-Sliding guide rail; 307-Support roller. Detailed Implementation

[0019] The following is in conjunction with the appendix Figures 1-6 The technical solution of the present invention will be further illustrated through specific embodiments.

[0020] This invention provides a non-destructive testing device for defects in the inner coating of a pipe, including an information receiving unit mounted on a support assembly. The information receiving unit can crawl on the surface of a light-guiding transparent tube 201. Multiple atomizing nozzles 202 are evenly arranged on the circumferential surface of the light-guiding transparent tube 201, and all atomizing nozzles 202 are connected to the internal space of the light-guiding transparent tube 201. A plug head 203 is fixed to one end of the light-guiding transparent tube 201 in a way that is easy to disassemble, and a plastic film 204 is provided at the axial position of the plug head 203. A pipe connector 205 is fixed to the other end of the light-guiding transparent tube 201 in a way that is easy to disassemble. The pipe connector 205 is used to connect to the exhaust port of an air pump or the outlet of a liquid pump. An ultraviolet generating component 206 is embedded inside the pipe connector 205, and the end face of the ultraviolet generating component 206 is fitted and aligned with the end face of the light-guiding transparent tube 201. The ultraviolet (UV) generating assembly 206 contains multiple UV lamp beads, which focus UV light onto the end face of the light guide tube 201 via lamp cups. The information receiving unit includes a cylindrical carrier 103 capable of axial movement on the surface of the light guide tube 201. Three wide-angle cameras 102 are mounted on the circumferential surface of the cylindrical carrier 103, distributed at 120° intervals. The information receiving unit also includes a square shell 101 for fixing the cylindrical carrier 103. Two extrusion roller support plates 107 are fixedly installed inside the square shell 101. Each extrusion roller support plate 107 has two symmetrically formed support slider grooves 114, and a support slider 115 is slidably installed in each support slider groove 114. Two extrusion rollers 108 with parallel axes and rolling contact with the surface of the light guide tube 201 are also provided between the opposing surfaces of the two extrusion roller support plates 107. The two extrusion rollers 108 are rotatably mounted on the corresponding two support sliders 115 via two drive shafts 112. The extrusion roller 108 is fixedly engaged with the drive shaft 112, and both ends of the drive shaft 112 are rotatably engaged with two support sliders 115. The support sliders 115 can only slide within the support slider groove 114 and have no rotational freedom. An elastic rope fixing frame 110 is fixed to the middle of the opposite sides of each of the two extrusion roller support plates 107. A collar bearing 113 is rotatably fitted onto both ends of each drive shaft 112, and all collar bearings 113 are elastically connected to the elastic rope fixing frame 110 via an elastic rope 111. A cover 109 is fixed to each extrusion roller support plate 107. The cover 109 is used to fasten the collar bearing 113, the elastic rope fixing frame 110, and the elastic rope 111 onto the extrusion roller support plate 107. The cover 109 also has a slot for allowing the drive shaft 112 to move linearly, preventing obstruction of the drive shaft 112's movement. The square shell 101 also has two drive motor sliding grooves 105, and a drive motor 106 is slidably installed in each of the two drive motor sliding grooves 105. The output shafts of the two drive motors 106 are coaxially and fixedly connected to the two drive shafts 112 respectively.The housing of the drive motor 106 slides linearly inside the drive motor sliding groove 105, and the housing of the drive motor 106 and the drive motor sliding groove 105 have no rotational freedom. Two paddle plates 104 are also slidably mounted on the square shell 101. The two paddle plates 104 are located on the side of the square shell 101 where the drive motor sliding groove 105 is opened, and the two paddle plates 104 are respectively fixed to the housings of the two drive motors 106.

[0021] The support assembly includes an outer protective frame 301 fixed to a square shell 101. The square shell 101 is fixed to the inner side of the outer protective frame 301. At least three centering support arms are movably mounted on the circumferential surface of the outer protective frame 301. Each centering support arm includes two symmetrically arranged swing arms 303. One end of the swing arm 303 is movably connected to the outer protective frame 301 via a hinge 302, and the other end of the swing arm 303 is rotatably mounted with a support roller 307. Each centering support arm also includes two spring telescopic rods 305 fixed to the outer protective frame 301. The actuating rods of the two spring telescopic rods 305 are fixed to a synchronous beam rod 304. Both ends of the synchronous beam rod 304 are fixed with pins. Each swing arm 303 has a sliding guide rail 306, and the pins are slidably disposed in the sliding guide rail 306.

[0022] First, fix the plug head 203 to one end of the light guide transparent tube 201. This plug head 203 needs to have a plastic film 204 on it. Both the plug head 203 and the plastic film 204 are disposable consumables; specifically, the plastic film 204 is a damaged part. Insert the light guide transparent tube 201 into the pipe whose inner coating needs to be tested. Control the insertion depth of the light guide transparent tube 201 according to the length of the pipe, ensuring the insertion depth is the same as the length of the pipe (the specific depth depends on the location requirements of the inner coating to be tested; this example tests the inner coating of the entire pipe). Then, install the pipe connector 205 at the other end of the light guide transparent tube 201. Next, connect the pipe connector 205 to the liquid pump and pump the water-washable fluorescent penetrant into the light guide transparent tube 201. Then, all the atomizing nozzles 202 on the light guide transparent tube 201 will spray the fluorescent penetrant onto the surface of the inner coating of the pipe, making the inner coating surface... After the fluorescent penetrant adheres to the surface, disconnect the connection between the pipe connector 205 and the liquid pump, and stop the liquid pump. Then connect the air pump to the pipe connector 205 and inject high-pressure gas into the pipe connector 205 through the air pump. This process will cause the residual fluorescent penetrant in the light guide transparent tube 201 to continue to be sprayed out through the atomizing nozzle 202. At the same time, due to the increase in pressure inside the light guide transparent tube 201, the plastic film 204 end cannot withstand the pressure and breaks. At this time, the two ends of the light guide transparent tube 201 are in a conductive state. At this time, the gas entering from the pipe connector 205 end will be sprayed out from the plastic film 204, and the residual fluorescent penetrant on the inner wall of the light guide transparent tube 201 will be removed in sequence. If the light guide tube 201 is short, the airflow inside the light guide tube 201 is less obstructed, and the internal pressure of the high-speed airflow inside the light guide tube 201 is low. This will cause the air outside the light guide tube 201 to enter the light guide tube 201 through the atomizing nozzle 202, thereby cleaning the residual fluorescent penetrant inside the atomizing nozzle 202. If the light guide tube 201 is long, the air pressure upstream will be greater (the resistance of the inner wall of the light guide tube 201 to airflow becomes greater, so the upstream gas pressure is greater than the downstream pressure). Under the action of pressure, the fluorescent penetrant is pushed out of the atomizing nozzle 202 by the gas, which also achieves the cleaning of the fluorescent penetrant.

[0023] The air pump is then removed, and a water pump is connected to pipe connector 205 to inject clean water into the pipe, thereby cleaning the coating on the inner wall of the pipe. For example, if one end of the pipe (the end in the same direction as the plug head 203) is blocked, the clean water entering through pipe connector 205 will be guided to the end of the pipe through the light guide tube 201, then pass through the plastic film 204, flow into the inside of the pipe, and finally flow out through the gap between the inner coating of the pipe and the outer surface of the light guide tube 201. It should be noted that the water-washable penetrant has the characteristic of being resistant to over-washing. This means that it can be washed away by water, but even if it is washed away for a little longer, the fluorescent agent that has already penetrated into the micro-cracks or defects will not be washed out, thus not affecting the detection effect. Therefore, if there are defects in the inner coating, fluorescent penetrant will still remain inside. After cleaning, remove the water pump and pipe connector 205. Finally, insert the support assembly with the information receiver into the pipe, and simultaneously insert the light guide transparent tube 201 through the two extrusion rollers 108 (by manually pushing the two paddle plates 104 away from each other, the two paddle plates 104 will drive the corresponding drive motor 106, drive shaft 112, and extrusion rollers 108 away from each other, thus increasing the distance between the two extrusion rollers 108 to facilitate the insertion of the light guide transparent tube 201. After insertion, release the paddle plates 104, and the elastic pull rope 111 will pull back the extrusion rollers 108 to keep them in contact with the surface of the light guide transparent tube 201). At the same time, press the three synchronous beam rods 304 to compress all the spring telescopic rods 305 to their limit positions so that all the centering support arms can extend into the pipe. Then release the synchronous beam rods 304, and under the elastic force of the spring telescopic rods 305, all the support rollers 307 will roll in contact with the inner coating of the pipe. Two drive motors 106 are started synchronously. The output shafts of the two drive motors 106 rotate in opposite directions but at the same speed. The drive motors 106 drive the corresponding pressing rollers 108 to rotate. The rotating pressing rollers 108 roll and crawl on the surface of the light-guiding transparent tube 201, thereby moving the entire information receiving unit along the light-guiding transparent tube 201. At this time, the ultraviolet (UV) generator 206 is activated, emitting UV light that enters the body of the light-guiding transparent tube 201, illuminating the entire inner coating of the tube (the irradiated UV light). If there are defects in the inner coating, the fluorescent penetrant within the defect will fluoresce due to UV irradiation. The three wide-angle cameras 102 will then observe whether fluorescence exists (the three wide-angle cameras 102 enable 360° comprehensive detection of the inner coating of the tube). Whether the defect is acceptable is judged by the outline shape and brightness of the fluorescence, directly reflecting the shape and size of the defect. After all the inner coatings of the tubes have been inspected, the drive motors 106 are controlled in reverse to remove the information receiving unit and support assembly from the tube, and then the light-guiding transparent tube 201 is pulled out.

Claims

1. A non-destructive testing device for defects in the inner coating of a pipeline, characterized in that: The light guide tube (201) includes an information receiving unit installed on a support assembly. The information receiving unit can crawl on the surface of the light guide tube (201). Multiple atomizing nozzles (202) are evenly arranged on the circumferential surface of the light guide tube (201). All atomizing nozzles (202) are connected to the internal space of the light guide tube (201). A plugging head (203) is fixed at one end of the light guide tube (201) in a way that is easy to disassemble. A plastic film (204) is provided at the axial position of the plugging head (203). The other end of the light guide transparent tube (201) is fixed with a pipe connector (205) in a way that is easy to disassemble. The pipe connector (205) is used to connect to the exhaust port of the air pump or the outlet of the liquid pump. An ultraviolet generating component (206) is embedded inside the pipe connector (205). The end face of the ultraviolet generating component (206) is fitted and aligned with the end face of the light guide transparent tube (201). The information receiving unit includes a cylindrical carrier (103) that can move axially on the surface of the light guide transparent tube (201). Three wide-angle cameras (102) are arranged on the circumferential surface of the cylindrical carrier (103), and the three wide-angle cameras (102) are distributed at 120° between each other on the cylindrical carrier (103).

2. The non-destructive testing device for defects in the inner coating of a pipeline according to claim 1, characterized in that: The information receiving unit also includes a square shell (101) for fixing the cylindrical carrier (103). Two extrusion roller support plates (107) are fixedly installed inside the square shell (101). Two support slider grooves (114) are symmetrically opened on each extrusion roller support plate (107). A support slider (115) is slidably installed in each support slider groove (114). Two extrusion rollers (108) with parallel axes and rolling cooperation with the surface of the light guide transparent tube (201) are also provided between the opposite surfaces of the two extrusion roller support plates (107). The two extrusion rollers (108) are rotatably installed on the corresponding two support sliders (115) through two drive shafts (112).

3. The non-destructive testing device for defects in the inner coating of a pipeline according to claim 2, characterized in that: The two extrusion roller support plates (107) are fixed with elastic rope fixing frames (110) in the middle of their opposite sides. Each drive shaft (112) is fitted with a collar bearing (113) at both ends. All collar bearings (113) are elastically connected to the elastic rope fixing frames (110) by elastic ropes (111).

4. The non-destructive testing device for defects in the inner coating of a pipeline according to claim 3, characterized in that: Two drive motor sliding slots (105) are also provided on the square shell (101). A drive motor (106) is slidably installed in each of the two drive motor sliding slots (105). The output shafts of the two drive motors (106) are coaxially and fixedly connected to the two drive shafts (112).

5. The non-destructive testing device for defects in the inner coating of a pipeline according to claim 4, characterized in that: Two paddle plates (104) are also slidably installed on the square shell (101). The two paddle plates (104) are located on the side of the square shell (101) where the drive motor sliding groove (105) is opened. The two paddle plates (104) are respectively fixed to the outer shell of the two drive motors (106).

6. The non-destructive testing device for defects in the inner coating of a pipeline according to claim 5, characterized in that: The support assembly includes an outer protective frame (301) fixed to the square shell (101), the square shell (101) being fixed to the inner side of the outer protective frame (301), and at least three centering support arms being movably mounted on the circumferential surface of the outer protective frame (301).

7. The non-destructive testing device for defects in the inner coating of a pipeline according to claim 6, characterized in that: Each centering support arm includes two symmetrically arranged swing arms (303). One end of the swing arm (303) is movably connected to the outer protective frame (301) via a hinge (302), and the other end of the swing arm (303) is rotatably mounted with a support roller (307).

8. The non-destructive testing device for defects in the inner coating of a pipeline according to claim 6, characterized in that: Each centering support arm also includes two spring telescopic rods (305) fixed on the outer protective frame (301). The actuating rods of the two spring telescopic rods (305) are fixed to the synchronous beam rod (304). Both ends of the synchronous beam rod (304) are fixed with pins. Each swing arm (303) has a sliding guide rail (306) with pins slidably set in the sliding guide rail (306).

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