CN111380951A

CN111380951A - Nondestructive detection method and device in long-distance pressure pipeline

Info

Publication number: CN111380951A
Application number: CN202010270099.2A
Authority: CN
Inventors: 李培娟; 谢屹鹏; 程娜; 李红凌; 刘雅卿; 马玉茹; 付晓飞; 郑炘
Original assignee: Boiler & Pressure Vessel Safety Inspection Institute Of Henan Province
Current assignee: Boiler & Pressure Vessel Safety Inspection Institute Of Henan Province
Priority date: 2020-04-08
Filing date: 2020-04-08
Publication date: 2020-07-07
Anticipated expiration: 2040-04-08
Also published as: CN111380951B

Abstract

The invention discloses a nondestructive detection method and a device in a long-distance pressure pipeline, wherein a mechanism capable of being uniformly unfolded in the radial direction is arranged on the periphery of a frame of a main machine of a magnetic powder detector, the main machine of the magnetic powder detector is arranged in the pressure pipeline, the peripheral mechanism of the frame is uniformly unfolded to enable the main machine of the magnetic powder detector to be positioned at an axis position, the tail ends of at least one pair of magnetic yoke arms of the main machine of the magnetic powder detector are supported on the arc surface of the inner wall of the pressure pipeline, so that a local magnetic field is formed in a region between the pair of magnetic yoke arms, meanwhile, dry powder or wet powder in a pressure state is sprayed on the region between the magnetic yoke arms by controlling a magnetic powder nozzle, and the distribution shape of the magnetic powder in the region between the magnetic yoke arms is collected to judge the existence of surface defects and the shapes and the positions of the defects, the method has great significance for the inspection of the pressure pipeline of special equipment.

Description

Nondestructive detection method and device in long-distance pressure pipeline

Technical Field

The invention belongs to the field of nondestructive detection equipment for special equipment pressure pipelines, and particularly relates to a nondestructive detection technology in a long-distance pressure pipeline.

Background

Non-destructive testing of pressure lines not only occurs during the manufacturing process, but also during the application process. Non-destructive testing is an important quality control measure in the manufacturing process of pressure pipe components. The pressure pipeline is produced continuously in batch in the manufacturing process, and the nondestructive testing of the manufacturing process is carried out continuously on a production line. The conventional non-destructive inspection methods for inspecting such defects are: magnetic powder, liquid penetration, ultrasonic irradiation, and radiography. Pressure pipe components belong to high-quality forgings, and more than one inspection method is often required in manufacturing, because magnetic powder and liquid penetration can only inspect defects on the surface, and in order to detect various internal defects, an inspection method combining ultrasonic waves and ray irradiation with the magnetic powder or liquid is required. In the manufacturing process or the using process of the pressure pipeline element, the magnetic particle detection method is often adopted to detect the defects of the pressure pipeline on the outer surface, the magnetic particle detection method is most sensitive to the surface defects, but the detection sensitivity of the defects below the surface is rapidly reduced along with the increase of the buried depth, various internal defects of the pressure pipeline are detected by ultrasonic waves, and the two methods are combined for use. However, the pressure pipe element cannot effectively detect the integrity of the inner wall surface of the pipe in the production and manufacturing process.

The pressure pipeline is applied to a long-distance pipeline system formed by pipeline welding after a boiler, the pressure pipeline is generally required to be further detected, the detection at the moment is more focused on the condition that the surface of the pressure pipeline is damaged due to processing, such as welding seams, elbows and local damage, magnetic powder detection is commonly adopted for detecting the outer surface of the pressure pipeline on the boiler, the sensitivity is higher than that of ultrasonic or ray detection, the operation is simple and convenient, the result is reliable, the price is low, meanwhile, ultrasonic detection is matched, the ultrasonic detection is effectively applied to the detection of the inner wall of the pipeline, but the effective detection on the surface of the inner wall of the pipeline cannot be realized. At present, no method for monitoring the inner wall of the boiler pressure pipeline through magnetic powder exists.

In addition, nondestructive test of pipeline under pressure installation and nondestructive test of boiler after long-time operation need carry out the spot check to the pressure pipe fitting at the installation scene, and the less tortoise-like surface defect can appear because of heating temperature and heating time are improper on the pipeline under pressure inner wall surface of long-time operation, examines time measuring to the pipeline under pressure in the maintenance process, can have the problem that can't carry out effective detection to pipeline inner wall surface, and this also is the technical problem that can't carry out inner wall magnetic particle testing to shaping pipeline under pressure on the boiler at present.

Disclosure of Invention

The invention provides an internal nondestructive detection method and device capable of running in the inner wall of a pressure pipeline to effectively detect the integrity of the surface of the inner wall of the pressure pipeline, aiming at the problems that the existing pressure pipeline has incomplete nondestructive detection in the production, manufacturing and application processes and the defects that the existing nondestructive detection equipment cannot effectively detect the integrity of the surface of the inner wall of the pipeline.

The scheme adopted by the invention is as follows: a nondestructive detection method in a long-distance pressure pipeline is characterized in that a mechanism capable of being uniformly unfolded in the radial direction is arranged on the periphery of a rack of a main machine of a magnetic powder detector, the main machine of the magnetic powder detector is arranged in the pressure pipeline, the peripheral mechanism of the rack is uniformly unfolded to enable the main machine of the magnetic powder detector to be positioned at an axis position, the tail ends of at least one pair of magnetic yoke arms of the main machine of the magnetic powder detector are supported on the arc surface of the inner wall of the pressure pipeline, so that a local magnetic field is formed in the area between the pair of magnetic yoke arms, meanwhile, dry powder or wet powder in a pressure state is sprayed on the area between the magnetic yoke arms by controlling a magnetic powder nozzle, the distribution shape of the magnetic powder in the area between the magnetic yoke arms is collected to be used for judging the existence of surface defects of the inner wall of the pressure pipeline and the shape, the magnetic powder detector host is repeatedly or reversely pulled to detect another radian area in the pressure pipeline along the axial direction until the whole inner wall of the whole circular ring of the pressure pipeline is completely detected.

The method further comprises a power wheel and a guide wheel which are positioned on the outer side of the pressure pipeline and fixed through a support, two ends of the pull rope are fixedly connected into a ring shape through a fastener, the part of the pull rope positioned on the outer side of the pressure pipeline is respectively sleeved in grooves of the power wheel and the guide wheel, the control end of the controller is used for controlling the power wheel to rotate, and the power wheel and the axial movement nondestructive testing machine work alternately.

A nondestructive detection device in a long-distance pressure pipeline comprises an axial-movement nondestructive detector, a pull rope and a powder spraying mechanism, wherein the axial-movement nondestructive detector comprises a rack, a magnetic powder detector host, a camera and a detection lamp, the magnetic powder detector host is positioned at the central position of the rack, at least three hinged seats are uniformly distributed at two ends of the rack along the circumference respectively, each hinged seat is hinged with a root swing arm through a root pin shaft, the root swing arm is hinged with a tail swing arm through a middle pin shaft, an axial connecting rod is hinged between the corresponding tail swing arms at two sides through the tail pin shafts, a metal magnetic yoke is fixed at the center of the axial connecting rod, a coil wound on the outer side of the metal magnetic yoke is connected with a power output end of the magnetic powder detector host through a power line, and the magnetic; the axial tension springs are connected between the corresponding swing arms at two sides, and the crank arm tension springs are connected between the swing arms at each side and the corresponding tail swing arms at the outer sides, so that the tail swing arms at each side can be automatically unfolded, namely the axial connecting rods can carry the metal magnetic yokes to be unfolded outwards, so that the corresponding metal magnetic yokes are contacted with the inner wall of the pressure pipeline, and a local magnetic field is formed in the arc-shaped area of the inner wall of the pressure pipeline between the adjacent opposite metal magnetic yokes; the magnetic powder particle detector is also provided with a wind pressure system, wherein an outlet of the wind pressure machine is communicated with an inlet of a constant-pressure air pressure tank, an outlet of the air pressure tank is communicated with the upper part of a closed magnetic powder box through a wind pressure pipe, dry magnetic powder or wet magnetic powder is filled in the closed magnetic powder box, the bottom of the magnetic powder box is connected with a nozzle electromagnetic valve through a powder conveying pipeline, a control end of a controller is connected with a control end of the nozzle electromagnetic valve, a signal end of the controller is connected with a signal end of a main machine of the magnetic powder detector, and the nozzle electromagnetic valve and each metal magnetic; and a detection lamp and a camera are arranged on the frame or the magnetic powder detector host, and a signal wire of the camera is connected with an external system host.

Above device still is provided with clear powder mechanism, including exhaust column, powder extraction cover, the bar magnet body and bar magnet power cord, the terminal extension of root swing arm is fixed with the extension arm, and the end of extension arm is fixed with the powder extraction cover, and the bar magnet body is equipped with to the powder extraction cover endotheca, has the clearance between the bar magnet body and the exhaust hood, and the bar magnet body passes through the bar magnet power cord and is connected with external power source, and the exhaust column communicates inside the exhaust hood, and the exhaust column is drawn forth pipeline outside and is connected with the air exhauster, and the order of air exhauster control convulsions and the supply of bar magnet body is the power supply relation in turn.

A nondestructive detection device in a long-distance pressure pipeline comprises an axial-movement nondestructive detector, a pull rope and a powder spraying mechanism, wherein the axial-movement nondestructive detector comprises a rack, a magnetic powder detector host, a camera and a detection lamp, the magnetic powder detector host is positioned at the central position of the rack, at least three hinging seats are uniformly distributed at two ends of the rack along the circumference respectively, each hinging seat is hinged with a single swinging arm through an end pin shaft, the tail end of each single swinging arm is hinged with an axial roller through a pin shaft respectively, and an axial tension spring is connected between the single swinging arms corresponding to the two ends, so that each single swinging arm at the two ends can be uniformly and automatically unfolded and supported on the inner wall of the pressure pipeline; at least three groups of elastic magnetic yoke mechanisms are uniformly distributed on the circumference of the rack or the magnetic powder detector main machine, coils of the elastic magnetic yoke mechanisms are connected with the power output end of the magnetic powder detector main machine through power lines, and the magnetic polarities of the tail ends of at least one pair of adjacent elastic magnetic yoke mechanisms are opposite; after each elastic magnetic yoke mechanism is unfolded, the tail end magnetic pole of each elastic magnetic yoke mechanism can be supported on the inner side wall of the pressure pipeline, so that a local magnetic field is formed in the arc-shaped area of the inner wall of the pressure pipeline between the adjacent opposite elastic magnetic yoke mechanisms; the magnetic powder particle detector is also provided with a wind pressure system, wherein an outlet of the wind pressure machine is communicated with an inlet of a constant-pressure air pressure tank, an outlet of the air pressure tank is communicated with the upper part of a closed magnetic powder box through a wind pressure pipe, dry magnetic powder or wet magnetic powder is filled in the closed magnetic powder box, the bottom of the magnetic powder box is connected with a nozzle electromagnetic valve through a powder conveying pipeline, a control end of a controller is connected with a control end of the nozzle electromagnetic valve, a signal end of the controller is connected with a signal end of a main machine of the magnetic powder detector, and the nozzle electromagnetic valve and each metal magnetic; and a detection lamp and a camera are arranged on the frame or the magnetic powder detector host, and a signal wire of the camera is connected with an external system host.

Every group elasticity yoke mechanism includes fixed outer tube, slip yoke subassembly, core yoke power cord and thrust spring, and wherein the slip yoke subassembly includes magnetism-insulating shell, coil and yoke core from outside to inside in proper order, and the yoke core end stretches out outside magnetism-insulating shell, fixed outer tube and slip yoke subassembly suit are in the same place, are connected with thrust spring between fixed outer tube bottom and slip yoke subassembly bottom, and the coil passes through the core yoke power cord and is connected with the power output end of magnetic powder detection instrument host computer.

The end part of the rack is provided with a fixed seat, the end part of the rack is sleeved with a rotating seat, the rotating seat and the fixed seat are sleeved together and can rotate, and the rotating seat and the fixed seat are fixed together through a lock pin.

At least three groups of elastic pin assemblies are uniformly distributed on the circumference of the frame or the main machine of the magnetic powder detector, each group of elastic pin assembly comprises a fixed outer sleeve, an elastic pin and a thrust spring, the fixed outer sleeve and the elastic pin are sleeved together, and the thrust spring is connected between the bottom of the fixed outer sleeve and the bottom of the elastic pin; still be provided with clear powder mechanism, including exhaust column, powder extraction cover, bar magnet body and bar magnet power cord, the powder extraction cover is fixed the end of elastic pin is taken out powder cover endotheca and is equipped with the bar magnet body, has the clearance between bar magnet body and the exhaust cover, and the bar magnet body passes through the bar magnet power cord and is connected with external power source, and inside the exhaust column intercommunication in the exhaust cover, the exhaust column draws forth pipeline under pressure outward and is connected with the air exhauster, and the order of air exhauster control convulsions and bar magnet power supply is the power supply relation in turn.

The nondestructive detection device in the long-distance pressure pipeline according to the claim or the above, characterized in that a telescopic driving mechanism is arranged on the powder conveying pipeline, and comprises a fixed sliding sleeve, a guide sliding sleeve and a turning seat.

The tail end of the compressed air pipe is hermetically connected with a fixed sliding sleeve, the fixed sliding sleeve and the guide sliding sleeve are respectively fixed at the root part of the fixed outer sleeve, the powder conveying pipeline comprises a telescopic section and an elastic bending section which are connected together, the elastic bending section is communicated with the nozzle, the lower end of the telescopic section is sleeved in the fixed sliding sleeve, and the fixed sliding sleeve is internally provided with a telescopic gap at one end so that the telescopic end can slide in the telescopic gap; the outer side of the nozzle is fixed with a turnover seat, the outer side of the fixed outer sleeve is sleeved with a hoop, and the hoop and the turnover seat are hinged together through a rotating shaft.

The invention has the beneficial effects that: the magnetic powder nondestructive testing device is applied to nondestructive testing of the inner wall surface of the pressure pipeline, equipment enters the pressure pipeline, and the integrity degree of the inner wall surface of the pressure pipeline is tested through the magnetic powder, so that the nondestructive testing of the inner wall of the pipeline can be carried out in the manufacturing process of the pressure pipeline and in long-term application. The method has the characteristics of no damage, low cost, high detection speed, strong practicability of field detection, high defect detection rate and the like, and has great significance for the inspection of the pressure pipeline of the special equipment.

The invention also cleans the inner wall to facilitate the smooth magnetic powder detection and improve the detection precision.

Drawings

FIG. 1 is a schematic view of the nondestructive testing method in the pipeline of the present invention.

FIG. 2 is a block diagram of a control portion of the nondestructive testing apparatus of the invention.

Fig. 3 is a cleaning mechanism control block diagram.

Fig. 4 is a cleaning area push diagram.

Fig. 5 is a schematic structural diagram of a first example of the present invention.

Fig. 6 is a side view of the structure of fig. 5.

Fig. 7 is a schematic structural diagram of a second example of the present invention.

Fig. 8 is a side view of the structure of fig. 7.

Fig. 9 is a schematic structural view of a third example of the present invention.

Fig. 10 is an isolated schematic view of the resilient yoke mechanism of fig. 9.

Fig. 11 is a schematic cross-sectional structure of fig. 10.

Fig. 12 is a schematic view showing the installation relationship of the telescopic drive mechanism.

Fig. 13 is an enlarged view of a portion a of fig. 12.

Fig. 14 is a schematic diagram of the transformed state of fig. 13.

Fig. 15 is an enlarged partial sectional view of fig. 14.

Reference numbers in the figures: pressure pipeline 1, root pin shaft 11, middle pin shaft 12, end pin shaft 13, end pin shaft 14, axial movement nondestructive testing machine 2, pull rope 3, power wheel 4, guide wheel 5, powder spraying mechanism 6, powder cleaning mechanism 7, elastic magnetic yoke mechanism 8, power data line 9, machine frame 21, fixed seat 211, rotating seat 212, lock pin 213, magnetic powder detector host 22, camera 221, detection lamp 222, hinged seat 23, root swing arm 24, single swing arm 24a, axial roller 24b, end swing arm 25, axial connecting rod 26, metal magnetic yoke 27, axial tension spring 28, crank arm tension spring 29, compressed air pipe 61, nozzle 62, telescopic driving mechanism 63, fixed sliding sleeve 631, guide sliding sleeve 632, turnover seat 633, telescopic section 634, elastic bending section 635, clamp 636, rotating shaft 637, telescopic gap 638, exhaust pipe 71, extension arm 72, powder extracting cover 73, magnetic rod body 74, magnetic rod power line 75, fixed outer sleeve 81, a slide yoke assembly 82, a magnetism insulating housing 821, a coil 822, a yoke core 823, a core yoke power supply line 83, a thrust spring 84, and an elastic pin 85.

Detailed Description

Example 1: a nondestructive detection method applied to a pressure pipeline is characterized in that a mechanism capable of being uniformly spread in the radial direction is arranged on the periphery of a frame of a main machine of a magnetic powder detector, the main machine of the magnetic powder detector is placed in the pressure pipeline, and the mechanism on the periphery of the frame is uniformly spread to enable the main machine of the magnetic powder detector to be located at an axis position as shown in figure 1. The ends of a plurality of pairs (the number of yoke arms is preferably even) of yoke arms of the magnetic particle detector main unit are supported on the arc surface of the inner wall of the pressure pipe, so that a local magnetic field is formed in the region between the pair of yoke arms, as shown in fig. 4. Meanwhile, dry powder or wet powder in a pressurized state is sprayed in an area between the magnetic yoke arms by controlling the magnetic powder nozzle (generally used magnetic powder detection is wet magnetic powder detection adopted when the pressure pipeline stops operating), the distribution shape of the magnetic powder in the area between the magnetic yoke arms is collected and used for judging the existence of the surface defect of the inner wall of the pressure pipeline and the shape and position of the defect, and one end or two ends of a main machine of the magnetic powder detector are connected through a pull rope.

As shown in fig. 1, the device further comprises a power wheel 4 and a guide wheel 5 which are positioned outside the pressure pipeline and fixed through a support, two ends of the pull rope are fixedly connected into a ring shape through a fastener, the part of the pull rope positioned outside the pressure pipeline is respectively sleeved in grooves of the power wheel 4 and the guide wheel 5, a control end of the controller is used for controlling the power wheel to rotate, and the power wheel to rotate and the axial displacement nondestructive testing machine to work alternately. The control stay cord is used for enabling the magnetic powder detector main machine to enter from one end of the pressure pipeline and pull out from the other end of the pressure pipeline, detecting a radian area in the pressure pipeline along the axial direction, enabling the pair of magnet yokes to correspond to an undetected arc section after the magnetic powder detector main machine rotates for an angle, and repeatedly or reversely pulling the magnetic powder detector main machine to enable the magnetic powder detector main machine to detect another radian area in the pressure pipeline along the axial direction until the whole inner wall of the circular ring of the pressure pipeline is completely detected.

The method can be implemented by adopting a nondestructive detection device in the pipeline as shown in fig. 5 and 6, and the device mainly comprises mechanical components such as a shaft-moving nondestructive detector 2, a pull rope 3 and a powder spraying mechanism 6.

The power data line 9 and the pull rope 3 are fixed together in parallel, the pull rope 3 is used as a bearing carrier to drive the instrument to move in the pressure pipeline, the power data line 9 is connected with an external alternating current power supply or a direct current power supply, and for the condition that the pressure pipelines in some areas are relatively dispersed to cause difficulty in power utilization or cannot be supplied with power at all, a mode of arranging a storage battery in the pressure pipelines is adopted, and the direct current magnetic yoke is utilized, so that the magnetic field of the magnetic yoke can deeply penetrate into the surface of a workpiece, and the defect of the deeper layer of the pressure.

As shown in fig. 5, the axial-movement nondestructive inspection apparatus 2 mainly includes a frame 21, a magnetic particle detector main body 22, a camera 221, and a detection lamp 222. Wherein, magnetic powder detector host computer 22 is located the central point of frame 21 and puts, and the both ends of frame 21 have four articulated seats 23 along the circumference equipartition respectively, and each articulated seat 23 articulates through root round pin axle 11 has a root swing arm 24, and root swing arm 24 articulates last swing arm 25 through well round pin axle 12, and it has axial connecting rod 26 to articulate through last round pin axle 13 between the last swing arm 25 that both sides correspond. As shown in the figure, a metal yoke 27 is fixed at the center of the axial link 26, and a coil wound around the outside of each metal yoke 27 is connected to a power supply output terminal of the magnetic particle detector main unit 22 through a power supply line. The end magnetic polarities of any two adjacent metal yokes 27 are opposite as shown in fig. 6.

Further, an axial tension spring 28 is connected between the respective swing arms 24 on both sides, and a crank tension spring 29 is connected to the outer side between each swing arm 24 and the respective end swing arm 25. So that the end swing arms 25 on each side can be automatically unfolded, i.e. the axial links 26 can carry the metal yokes 27 to be unfolded outwards. The flared driving force can bring each metal yoke 27 into contact with the inner wall of the pressure pipe, thereby forming a local magnetic field as shown in fig. 4 in the arc-shaped region of the inner wall of the pressure pipe between adjacent opposite metal yokes 27.

The wind pressure system is arranged by matching with the scheme, the outlet of the wind pressure machine in fig. 2, 5 and 6 is communicated with the inlet of the constant pressure air tank, the outlet of the air pressure tank is communicated with the upper part of the closed magnetic powder box through a compressed air pipe 61, dry magnetic powder or wet magnetic powder is filled in the closed magnetic powder box, and the bottom of the magnetic powder box is connected with the nozzle electromagnetic valve through a powder conveying pipeline (the electromagnetic valve is connected on the output pipe of the nozzle 62). The control end of the controller is connected with the control end of the nozzle electromagnetic valve, the signal end of the controller is connected with the signal end of the magnetic particle detector main machine 22, and the nozzle electromagnetic valve and each metal magnetic yoke 27 are powered alternately. And a detection lamp and a camera are arranged on the frame 21 or the magnetic powder detector host 22, and a signal wire of the camera is connected with an external system host.

Example 2: the powder cleaning mechanism 7 is further arranged on the basis of the embodiment 1, as shown in fig. 7 and 8, the powder cleaning mechanism comprises an exhaust pipe 71, a powder extracting cover 73, a magnetic rod body 74 and a magnetic rod power line 75, an extension arm 72 is fixed at the tail end of the swing arm 24 in an extending mode, the powder extracting cover 73 is fixed at the tail end of the extension arm 72, the magnetic rod body 74 is sleeved in the powder extracting cover 73, a gap exists between the magnetic rod body 74 and the exhaust cover 73, the magnetic rod body 74 is connected with an external power source through the magnetic rod power line 75, the exhaust pipe 71 is communicated with the inside of the exhaust cover 73, the exhaust pipe 71 is led out of a pressure pipeline and is connected with an exhaust fan, and the exhaust fan controls the power supply sequence of the air extraction and the magnetic rod body 74 to.

Example 3: a nondestructive detection device in a long-distance pressure pipeline is shown in figure 9 and mainly comprises a shaft-moving nondestructive detector 2, a pull rope 3, a powder spraying mechanism 6 and the like. The axial movement nondestructive testing machine 2 in the mechanism mainly comprises a frame 21, a magnetic particle detector main machine 22, a camera 221 and a detection lamp 222.

As shown in fig. 9, the magnetic particle detector main unit 22 is located at the center of the frame 21, four hinge seats 23 are uniformly distributed at two ends of the frame 21 along the circumference, each hinge seat 23 is hinged with a single swing arm 24a through an end pin, and the tail end of each single swing arm 24a is hinged with an axial roller 24 through a pin. As can be seen from the figure, the axial tension spring 28 is connected between the single swing arms 24a corresponding to the two ends, so that each single swing arm 24a at the two ends can be uniformly and automatically unfolded and supported on the inner wall of the pressure pipeline, and can tightly attach to the inner wall of the pressure pipeline to axially travel.

Meanwhile, four groups of elastic magnetic yoke mechanisms 8 are uniformly distributed on the circumference of the rack 21 or the magnetic powder detector main machine 22. As shown in fig. 9, the coil of the elastic yoke mechanism 8 is connected to the power output end of the magnetic particle detector main unit 22 through a power line, and the magnetic polarities of the ends of any two adjacent groups of elastic yoke mechanisms 8 are opposite. After each elastic magnetic yoke mechanism 8 is unfolded, the tail end magnetic pole of each elastic magnetic yoke mechanism can be supported on the inner side wall of the pressure pipeline, so that a local magnetic field is formed in the arc-shaped area of the inner wall of the pressure pipeline between the adjacent elastic magnetic yoke mechanisms 8 with opposite polarities as shown in fig. 4.

The device of the present embodiment is also provided with a wind pressure system, but the wind pressure system is different from embodiment 1, in this embodiment, the outlet of the wind pressure machine of the wind pressure system is communicated with the inlet of the constant pressure air pressure tank, the outlet of the air pressure tank is communicated with the upper part of the closed magnetic powder box through the compressed air pipe 61, dry magnetic powder or wet magnetic powder is filled in the closed magnetic powder box, and the bottom of the magnetic powder box is connected with the nozzle electromagnetic valve through the powder conveying pipeline (the electromagnetic valve is connected on the output pipe of the nozzle 62). As shown in fig. 2, the control end of the controller is connected with the control end of the nozzle electromagnetic valve, the signal end of the controller is connected with the signal end of the magnetic particle detector main unit 22, and the nozzle electromagnetic valve and each metal yoke 27 are powered alternately; and a detection lamp and a camera are arranged on the frame 21 or the magnetic powder detector host 22, and a signal wire of the camera is connected with an external system host.

As shown in fig. 10 and 11, each set of elastic yoke mechanisms 8 includes a fixed outer sleeve 81, a sliding yoke assembly 82, a core yoke power supply line 83, and a thrust spring 84, respectively. The sliding magnetic yoke assembly 82 comprises a magnetism isolating shell 821, a coil 822 and a magnetic yoke core 823 from outside to inside in sequence, the tail end of the magnetic yoke core 823 extends out of the magnetism isolating shell 821, the fixed outer sleeve 81 is sleeved with the sliding magnetic yoke assembly 82, a thrust spring 84 is connected between the bottom of the fixed outer sleeve 81 and the bottom of the sliding magnetic yoke assembly 82, and the coil 822 is connected with the power output end of the magnetic powder detector main unit 22 through a core yoke power line 83.

In addition to the above configuration of the present embodiment, four sets of elastic pin assemblies are uniformly distributed on the circumference of the frame 21 or the magnetic particle detector main unit 22, and each set of elastic pin assembly includes a fixed outer sleeve 81, an elastic pin 85 and a thrust spring 84 as shown in fig. 9. The fixed outer sleeve 81 is sleeved with an elastic pin 85, and a thrust spring 84 is connected between the bottom of the fixed outer sleeve 81 and the bottom of the elastic pin 85. Still be provided with clear powder mechanism 7, including exhaust column 71, take out powder cover 73, bar magnet body 74 and bar magnet power cord 75, take out powder cover 73 and fix the end of elastic pin 85, take out powder cover 73 endotheca and be equipped with bar magnet body 74, there is the clearance between bar magnet body 74 and the exhaust hood 73, bar magnet body 74 passes through bar magnet power cord 75 and is connected with external power source, and exhaust column 71 communicates inside exhaust hood 73, and exhaust column 71 draws forth the pipeline of pressure and is connected with the air exhauster outward, and the order of air exhauster control convulsions and the power supply of bar magnet body 74 is the power supply relation in turn.

Example 4: in addition to embodiment 3, as shown in fig. 9, a fixed seat 211 is further provided at an end of the frame 21, a rotating seat 212 is sleeved on the end of the frame 21, and the rotating seat 212 and the fixed seat 211 are sleeved together to be rotatable, and are fixed together by a lock pin 213.

Example 5: on the basis of embodiment 3, a telescopic driving mechanism 63 is further disposed on the powder conveying pipeline, and the telescopic driving mechanism includes a fixed sliding sleeve 631, a guide sliding sleeve 632, and a turning seat 633. As shown in fig. 13-15, the end of the pneumatic tube 61 is sealingly connected to a fixed sliding sleeve 631, the fixed sliding sleeve 631 and the guiding sliding sleeve 633 are respectively fixed to the root of the fixed outer casing 81, the powder delivery pipe includes a flexible section 634 and a flexible curved section 635 connected together, wherein the flexible curved section 635 is in communication with the nozzle 62, the lower end of the flexible section 634 is sleeved in the fixed sliding sleeve 631, and the fixed sliding sleeve 631 has an end flexible gap 638 such that the flexible section 634 can slide in the flexible gap 638; the outside of nozzle is fixed with upset seat 633, again fixed outer tube 81 outside cover is equipped with clamp 636, and clamp 636 articulates together through pivot 637 between the upset seat 633.

Claims

1. A nondestructive detection method in a long-distance pressure pipeline is characterized in that a mechanism capable of being uniformly unfolded in the radial direction is arranged on the periphery of a machine frame of a main machine of a magnetic powder detector, the main machine of the magnetic powder detector is arranged in the pressure pipeline, the peripheral mechanism of the machine frame is uniformly unfolded to enable the main machine of the magnetic powder detector to be in an axis position, the tail ends of at least one pair of magnetic yoke arms of the main machine of the magnetic powder detector are supported on the arc surface of the inner wall of the pressure pipeline, so that a local magnetic field is formed in the area between the pair of magnetic yoke arms, meanwhile, dry powder or wet powder in a pressure state is sprayed on the area between the magnetic yoke arms by controlling a magnetic powder nozzle, the distribution shape of the magnetic powder in the area between the magnetic yoke arms is collected and used for judging the existence of surface defects and the shape and position of the defects on the inner wall of the pressure, the magnetic powder detector host is repeatedly or reversely pulled to detect another radian area in the pressure pipeline along the axial direction until the whole inner wall of the whole circular ring of the pressure pipeline is completely detected.

2. The nondestructive testing method for the inside of the long-distance pressure pipeline according to claim 1, further comprising a power wheel and a guide wheel which are positioned outside the pressure pipeline and fixed through a bracket, wherein two ends of the pull rope are fixedly connected into a ring shape through a fastener, the part of the pull rope positioned outside the pressure pipeline is respectively sleeved in grooves of the power wheel and the guide wheel, a control end of the controller is used for controlling the power wheel to rotate, and the power wheel to rotate and the axial movement nondestructive testing machine to work alternately.

3. A nondestructive detection device in a long-distance pressure pipeline comprises an axial-movement nondestructive detector (2), a pull rope (3) and a powder spraying mechanism (6), and is characterized in that the axial-movement nondestructive detector (2) comprises a rack (21), a magnetic powder detector main machine (22), a camera 221 and a detection lamp 222, the magnetic powder detector main machine (22) is located at the central position of the rack (21), at least three hinged seats (23) are uniformly distributed at two ends of the rack (21) along the circumference respectively, each hinged seat (23) is hinged with a root swing arm (24) through a root pin shaft, the root swing arm (24) is hinged with a tail swing arm (25) through a middle pin shaft, an axial connecting rod (26) is hinged between the tail swing arms (25) corresponding to two sides through the tail pin shaft, a metal magnetic yoke (27) is fixed at the center of the axial connecting rod (26), and a coil wound on the outer side of the metal magnetic yoke (27) is connected with a power output end, the end magnetic polarities of at least one pair of adjacent metal yokes (27) are opposite; an axial tension spring (28) is connected between the corresponding swing arms (24) at two sides, and a crank arm tension spring 29 is connected between the swing arm (24) at each side and the corresponding tail swing arm (25), so that the tail swing arms (25) at each side can be automatically unfolded, namely, the axial connecting rod (26) can carry the metal magnetic yoke (27) to be unfolded outwards, so that the corresponding metal magnetic yoke (27) is in contact with the inner wall of the pressure pipeline, and a local magnetic field is formed in the arc-shaped area of the inner wall of the pressure pipeline between the adjacent opposite metal magnetic yokes (27); the magnetic powder particle detector is also provided with a wind pressure system, wherein an outlet of the wind pressure machine is communicated with an inlet of a constant-pressure air pressure tank, an outlet of the air pressure tank is communicated with the upper part of a closed magnetic powder box through a wind compression pipe (61), dry magnetic powder or wet magnetic powder is filled in the closed magnetic powder box, the bottom of the magnetic powder box is connected with a nozzle electromagnetic valve through a powder conveying pipeline, a control end of a controller is connected with a control end of the nozzle electromagnetic valve, a signal end of the controller is connected with a signal end of a main machine (22) of the magnetic powder detector, and the nozzle electromagnetic valve and each metal magnetic yoke (27); and a detection lamp and a camera are arranged on the frame (21) or the magnetic powder detector host (22), and a signal wire of the camera is connected with an external system host.

4. The nondestructive detection device in the long-distance pressure pipeline according to claim 3 is further provided with a powder cleaning mechanism (7) which comprises an air exhaust pipe (71), a powder exhaust cover (73), a magnetic rod body (74) and a magnetic rod power line (75), wherein an extension arm (72) is fixed at the tail end of the swing arm (24) in an extending mode, the powder exhaust cover (73) is fixed at the tail end of the extension arm (72), the magnetic rod body (74) is sleeved in the powder exhaust cover (73), a gap exists between the magnetic rod body (74) and the air exhaust cover (73), the magnetic rod body (74) is connected with an external power supply through the magnetic rod power line (75), the air exhaust pipe (71) is communicated with the inside of the air exhaust cover (73), the air exhaust pipe (71) is led out of the pressure pipeline and connected with the air exhaust fan, and the air exhaust fan controls the power supply sequence of air exhaust and the magnetic rod body (74) to be in.

5. A nondestructive detection device in a long-distance pressure pipeline comprises an axial-movement nondestructive detector (2), a pull rope (3) and a powder spraying mechanism (6), and is characterized in that the axial-movement nondestructive detector (2) comprises a rack (21), a magnetic powder detector host (22), a camera 221 and a detection lamp 222, wherein the magnetic powder detector host (22) is located at the central position of the rack (21), at least three hinged seats (23) are uniformly distributed at two ends of the rack (21) along the circumference respectively, each hinged seat (23) is hinged with a single swing arm (24 a) through an end pin shaft, the tail end of each single swing arm (24 a) is hinged with an axial roller (24) through a pin shaft respectively, and an axial tension spring (28) is connected between the single swing arms (24 a) corresponding to the two ends, so that the single swing arms (24 a) at the two ends can be uniformly and automatically unfolded and supported on the inner wall of the pressure; at least three groups of elastic magnetic yoke mechanisms (8) are uniformly distributed on the circumference of the rack (21) or the magnetic powder detector main machine (22), coils of the elastic magnetic yoke mechanisms (8) are connected with a power output end of the magnetic powder detector main machine (22) through power lines, and the magnetic polarities of the tail ends of at least one pair of adjacent elastic magnetic yoke mechanisms (8) are opposite; after each elastic magnetic yoke mechanism (8) is unfolded, the tail end magnetic pole of each elastic magnetic yoke mechanism can be supported on the inner side wall of the pressure pipeline, so that a local magnetic field is formed in the arc-shaped area of the inner wall of the pressure pipeline between the adjacent opposite elastic magnetic yoke mechanisms (8); the magnetic powder particle detector is also provided with a wind pressure system, wherein an outlet of the wind pressure machine is communicated with an inlet of a constant-pressure air pressure tank, an outlet of the air pressure tank is communicated with the upper part of a closed magnetic powder box through a wind compression pipe (61), dry magnetic powder or wet magnetic powder is filled in the closed magnetic powder box, the bottom of the magnetic powder box is connected with a nozzle electromagnetic valve through a powder conveying pipeline, a control end of a controller is connected with a control end of the nozzle electromagnetic valve, a signal end of the controller is connected with a signal end of a main machine (22) of the magnetic powder detector, and the nozzle electromagnetic valve and each metal magnetic yoke (27); and a detection lamp and a camera are arranged on the frame (21) or the magnetic powder detector host (22), and a signal wire of the camera is connected with an external system host.

6. The long-distance pressure pipeline nondestructive detection device according to claim 5, wherein each set of elastic magnetic yoke mechanism (8) comprises a fixed outer sleeve (81), a sliding magnetic yoke assembly (82), a core yoke power line (83) and a thrust spring (84), wherein the sliding magnetic yoke assembly (82) comprises a magnetism isolating shell (821), a coil (822) and a magnetic yoke core body (823) from outside to inside in sequence, the tail end of the magnetic yoke core body (823) extends out of the magnetism isolating shell (821), the fixed outer sleeve (81) is sleeved with the sliding magnetic yoke assembly (82), the thrust spring (84) is connected between the bottom of the fixed outer sleeve (81) and the bottom of the sliding magnetic yoke assembly (82), and the coil (822) is connected with the power output end of the magnetic powder detector main unit (22) through the core yoke power line (83).

7. The nondestructive detection device in the long-distance pressure pipeline according to claim 5 is characterized in that a fixed seat (211) is arranged at the end of the frame (21), a rotating seat (212) is sleeved at the end of the frame (21), and the rotating seat (212) and the fixed seat (211) are sleeved together and can rotate and are fixed together through a lock pin (213).

8. The nondestructive detection device in the long-distance pressure pipeline according to claim 6 is characterized in that at least three groups of elastic pin assemblies are uniformly distributed on the circumference of the rack (21) or the magnetic particle detector main unit (22), each group of elastic pin assembly comprises a fixed outer sleeve (81), an elastic pin (85) and a thrust spring (84), the fixed outer sleeve (81) and the elastic pin (85) are sleeved together, and the thrust spring (84) is connected between the bottom of the fixed outer sleeve (81) and the bottom of the elastic pin (85); still be provided with clear powder mechanism (7), including exhaust column (71), powder extraction cover (73), the bar magnet body (74) and bar magnet power cord (75), powder extraction cover (73) is fixed the end of elastic pin (85), powder extraction cover (73) endotheca is equipped with the bar magnet body (74), there is the clearance between bar magnet body (74) and exhaust hood (73), the bar magnet body (74) are connected with external power source through bar magnet power cord (75), inside exhaust column (71) communicate in exhaust hood (73), outside pressure tube was drawn forth in exhaust column (71) is connected with the air exhauster, the order of exhaust fan control convulsions and bar magnet body (74) power supply is the power supply relation in turn.

9. The nondestructive detection device in the long-distance pressure pipeline according to claim 6 or 8 is characterized in that a telescopic driving mechanism (63) is arranged on the powder conveying pipeline and comprises a fixed sliding sleeve (631), a guide sliding sleeve (632) and a turnover seat (633).

10. The nondestructive detection device in the long-distance pressure pipeline according to claim 9, wherein the end of the air compressing pipe (61) is hermetically connected with a fixed sliding sleeve (631), the fixed sliding sleeve (631) and the guiding sliding sleeve (633) are respectively fixed at the root of the fixed outer casing (81), the powder conveying pipeline comprises a telescopic section (634) and an elastic bending section (635) which are connected together, wherein the elastic bending section (635) is communicated with the nozzle 62, the lower end of the telescopic section (634) is sleeved in the fixed sliding sleeve (631), and the fixed sliding sleeve (631) contains a telescopic gap (638) at one end so that the telescopic end (634) can slide in the telescopic gap (638); the outer side of the nozzle is fixed with a turning seat (633), a hoop (636) is sleeved on the outer side of the fixed outer sleeve (81), and the hoop (636) is hinged with the turning seat (633) through a rotating shaft (637).