Spiral steel pipe leakage defect detection device
By using a spiral steel pipe leakage defect detection device, which combines airbag sealing and photoelectric detection mechanism with rotary drive and radial and axial sensors, the problem of difficulty in determining the leakage location of spiral steel pipes is solved, and the leakage location is accurately located, which facilitates subsequent repair welding.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-03
- Publication Date
- 2026-04-10
AI Technical Summary
Existing methods for detecting leaks in spiral steel pipes can only detect overall leaks, but cannot pinpoint the specific location of the leak, which affects subsequent repair welding work.
A spiral steel pipe leakage defect detection device is adopted, including a water tank, a rotating support, an airbag sealing, a photoelectric detection mechanism, and a spiral steel pipe rotation drive mechanism. The leakage point is determined by detecting the position of air bubbles through inflation and rotation, combined with radial and axial photoelectric sensors.
It enables precise location of leaks in spiral steel pipes, facilitating subsequent repair welding.
Smart Images
Figure CN121829907A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of spiral steel pipe manufacturing technology, and in particular to a device for detecting leakage defects in spiral steel pipes. Background Technology
[0002] Spiral welded steel pipes are widely used in industries such as petroleum, chemical, water supply, and gas supply, serving as pipelines for transportation. The manufacturing process of spiral welded steel pipes uses strip steel coils as raw material. The strip steel is uncoiled, leveled, trimmed, planed, surface cleaned, and pre-bent. Then, it is rolled at room temperature in a forming machine through multiple rollers to form a circular tube blank with an open gap. This blank is then welded using an automatic double-wire double-sided submerged arc welding process to produce the finished spiral welded steel pipe. Because the raw material strip steel itself may have defects such as cracks, and the welding process inevitably introduces defects such as porosity and cracks, the finished spiral welded steel pipes must undergo leak detection. Existing water pressure testing methods can only detect whether there are leaks in the entire spiral welded steel pipe, but cannot determine the specific location of the leak. Spiral welded steel pipes are generally 12-18 meters long and can have a diameter of over 1 meter. The inability to pinpoint the exact location of the defect seriously affects subsequent repair welding work. Therefore, the industry urgently needs to solve this problem. Summary of the Invention
[0003] The purpose of this invention is to provide a spiral steel pipe leakage defect detection device, which can detect air leakage defects in spiral steel pipes and determine the specific location of the leak in real time, facilitating subsequent repair welding work.
[0004] To achieve the above objectives, the present invention adopts the following technical solution: A leak detection device for spiral steel pipes includes a base frame, a water tank, water, a rotating support, a tie rod, a right sealing cover, a left sealing cover, a right airbag, a left airbag, an air pipeline (first and second), a photoelectric detection mechanism, and a spiral steel pipe rotation drive mechanism. The water tank is mounted on the base frame, and the rotating support has two spaced-apart components, both positioned within the water tank. The right airbag is placed in the inner cavity of the right end of the spiral steel pipe, and the left airbag is placed in the inner cavity of the left end of the spiral steel pipe. The right and left airbags are connected by the first air pipeline. The right sealing cover is located on one side of the right end of the spiral steel pipe, serving to block the right airbag. The left sealing cover is located on the right side of the spiral steel pipe. The left end of the spiral steel pipe serves to block the left airbag. Two threaded rods at both ends are used to tighten and fix the right and left sealing caps. The left end of air line one passes through the hole on the left sealing cap and is connected to the air source through a quick-connect coupling. Air line two passes through the holes on the left airbag and the left sealing cap and is connected to the air source through a quick-connect coupling. The spiral steel pipe rotation drive mechanism is mounted on the base frame and is used to drive the spiral steel pipe to rotate. Pressurized gas is filled into the spiral steel pipe, and a photoelectric detection mechanism is used to detect and locate the leak point. The water in the tank vertically submerges the lower quarter of the spiral steel pipe.
[0005] The aforementioned spiral steel pipe leakage defect detection device includes a spiral steel pipe rotation drive mechanism comprising a three-jaw chuck assembly, a motor, a sliding seat, and a motor base. The motor base is mounted on a base frame, and the sliding seat is mounted on the motor base and can move left and right. Limiting blocks are provided at both ends of the motor base. The motor is fixedly mounted on the sliding seat, the three-jaw chuck assembly clamps the spiral steel pipe, and the motor drives the three-jaw chuck assembly to rotate through a drive shaft.
[0006] The aforementioned spiral steel pipe leakage defect detection device includes a photoelectric detection mechanism comprising a radial detection section and an axial detection section. Radial detection employs a through-beam photoelectric sensor, while axial detection employs a reflective photoelectric sensor. Photoelectric emitters for radial detection are mounted on a radial photoelectric emitting disk, each powered by a first lithium battery mounted on the disk. Photoelectric receivers for radial detection are mounted on a radial photoelectric receiving disk, each powered by a second lithium battery mounted on the disk. The emitter of the photoelectric receiver is connected to the indicator light control electrode mounted on the radial signal display screen. This control electrode is the base of transistor T1, and the collector of transistor T1 is connected to the power supply V+ via indicator light D and a second resistor R2. Thus, when the signal of the photoelectric receiver changes, the signal of indicator light D also changes accordingly. The photoelectric emitters and receivers for axial detection are mounted on the axial photoelectric tube strip 25. Similar to the radial photoelectric detection principle, when leakage bubbles are generated along the axial direction, the signal of the photoelectric receiver changes, and indicator light L... The signal will indicate the change; the radial photoelectric receiving disk and the second lithium battery are installed on the left sealing cover, the radial photoelectric transmitting disk and the first lithium battery are installed on the right sealing cover, the circuit tube is installed in the center of the left sealing cover, and an axial photoelectric tube is provided at the bottom of the water tank.
[0007] The aforementioned spiral steel pipe leakage defect detection device has a circular protrusion on the right and left sealing caps facing the spiral steel pipe, and the inner diameter of the circular protrusion corresponds to the outer diameter of the spiral steel pipe.
[0008] The aforementioned spiral steel pipe leakage defect detection device has both the right and left sealing caps suspended from the upper crossbeam by ropes.
[0009] The present invention has the following advantages: In this invention, a spiral steel pipe is hoisted and placed on a rotating support in a water tank. Airbags are used to seal both ends of the spiral steel pipe, and gas is injected into the inner cavity of the pipe. A three-jaw chuck assembly is used to clamp the spiral steel pipe, and a motor drives the pipe to rotate slowly. The lower quarter of the spiral steel pipe is immersed in water. Bubbles will emerge at defective locations. The location of the bubbles detected by the photoelectric detection mechanism is the defective area. This invention can accurately detect leaks in the spiral steel pipe. Attached Figure Description
[0010] Figure 1 This is a cross-sectional schematic diagram of the present invention; Figure 2 for Figure 1 Schematic diagram of the sectional view along the central AA direction; Figure 3 This is a schematic diagram of a rotating support structure; Figure 4 This is a schematic diagram of an axial phototube. Figure 5 The electrical schematic diagram for the detection and display section is shown below. The detection schematic diagram of the radial phototube is the same as that of the axial phototube. The circuit control principle of the indicator light D used for radial signal display or the indicator light L used for axial signal display is also the same. Figure 6 This is a schematic diagram of a radial signal display screen; Figure 7 This is a schematic diagram of an axial signal display screen.
[0011] The labels in the diagram represent: 1. Base frame, 1-1. Upper crossbeam, 2. Water tank, 3. Water, 4. Rotating support, 5. Spiral steel pipe, 6. Tie rod, 7. Right sealing cap, 8. Left sealing cap, 9. Right airbag, 10. Left airbag, 11. Radial photoelectric receiver, 12. Radial photoelectric transmitter, 13. First lithium battery, 14. Three-jaw chuck assembly, 15. Air pipe one, 16. Rope, 17. Air pipe two, 18. Circuit pipe, 19. Second lithium battery, 20. Drain pipe, 21. Inlet pipe, 22. Motor, 23. Sliding seat, 24. Motor base, 25. Axial photoelectric tube belt, 26. Radial signal display screen, 27. Axial signal display screen, R1-R3. Resistors, U1. Photoelectric transmitter, U2. Photoelectric receiver, D1-Dn. Radial signal indicator, L1-Ln. Axial signal indicator, T1. Transistor. Detailed Implementation
[0012] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0013] The spiral steel pipe leakage defect detection device of the present invention, such as Figure 1 and Figure 2As shown, a rectangular water tank 2 is set on a base frame 1. Two rotating supports 4 are located in the middle of the water tank 2. Rollers are installed on the rotating supports 4. The spiral steel pipe 5 is rotatably placed on the rotating supports 4. During leak detection, a right airbag 9 and a left airbag 10 are placed in the inner cavities of both ends of the spiral steel pipe 5, respectively. First, air is injected into the two airbags through air pipe 15 to seal the inner cavity of the steel pipe. Then, air is injected into the inner cavity of the spiral steel pipe 5 through air pipe 2 17. Air pipe 2 17 passes through the left airbag 10 and is sealed and fixed together with the left airbag 10. A right sealing cap 7 and a left sealing cap 8 are set on both ends of the spiral steel pipe 5, respectively, to block the two airbags and prevent them from overflowing. The right sealing cap 7 and the left sealing cap 8 are fixed together using a threaded pull rod 6. The tightness is adjusted by the thread. The spiral steel pipe 5 is immersed in the water in the water tank until one-quarter of it is submerged.
[0014] This invention uses a spiral steel pipe rotation drive mechanism to drive the spiral steel pipe 5 to rotate. The spiral steel pipe rotation drive mechanism includes a three-jaw chuck assembly 14, a motor 22, a sliding seat 23, and a motor base 24. The motor base 24 is mounted on the base frame 1. The sliding seat 23 is mounted on the motor base 24 and can move left and right. Limiting blocks are provided at both ends of the motor base 24. The motor 22 is fixedly mounted on the sliding seat 23. The three-jaw chuck assembly 14 clamps the spiral steel pipe 5. The motor 22 drives the three-jaw chuck assembly 14 to rotate through the drive shaft. The structure of the three-jaw chuck assembly 14 is similar to that of the three-jaw chuck structure used in ordinary lathes.
[0015] The photoelectric detection mechanism of this invention is used to accurately determine the leakage point of the spiral steel pipe 5. The photoelectric detection mechanism includes a radial detection section and an axial detection section. The radial detection section uses a through-beam photoelectric sensor. The emitting tubes of the photoelectric tubes are mounted on a transmitting disk, which is an insulating plastic plate, either disc-shaped or annular, and is installed on the left side of the right sealing cover 7, referred to as the radial photoelectric emitting disk 12. Photoelectric emitting tubes are evenly spaced on the transmitting disk, and the photoelectric emitting tubes are powered by lithium batteries 13. The lithium batteries require insulation measures to ensure power supply safety. The receiving tubes of each photoelectric tube are evenly spaced on an annular plastic plate, referred to as the radial photoelectric receiving disk 11. The receiving disk is fixed to the right side of the left sealing cover 8 of the spiral steel pipe 5 to receive signals from the emitting tubes of the photoelectric tubes. The photoelectric receiving tubes on the receiving disk correspond one-to-one with the photoelectric emitting tubes on the transmitting disk. The signals emitted by the photoelectric emitting tubes are received by the photoelectric receiving tubes on the receiving disk. If there is air leakage, bubbles rising from the water will affect the signal reception of the receiving tubes, showing an abnormal signal, which will then be displayed on the receiving tubes. Since the receiving tubes and transmitting tubes correspond one-to-one and are evenly distributed along the signal receiving disk, the radial location of the leak can be determined from the location of the receiving tube where the abnormal signal occurs.
[0016] Furthermore, since the receiving disk is located on the right side of the left sealing cover 8, it is not easily observed by the inspector. Therefore, this invention also includes a radial signal display screen 26, which can be placed anywhere that is easy to observe. It can be circular or in a coordinate form. The radial photoelectric sensor and the radial signal display screen are connected together by a signal line, which can pass through the line tube 18 for connection. A brush structure is provided at the connection point. Figure 6 As shown, one embodiment of the present invention is to set D1-Dn indicator lights on the radial signal display screen 26, with each indicator light corresponding to a receiving tube. The indicator lights D1-Dn on the radial signal display screen are spaced apart by 3-5cm. Thus, for a steel pipe with a diameter of 1m, only 12-20 indicator lights are needed on the radial signal display screen to clearly display the pipe.
[0017] Figure 5 The circuit diagram illustrates the principle of photoelectric detection and display. The first resistor R1 is the current-limiting resistor for the phototube emitter U1, and U2 is the phototube receiver. The emitter of the receiver is connected to the base of transistor T1 via the third resistor R3. The second resistor R2 is connected in series with the indicator light as the collector load. Thus, the signal changes from the receiver U2 are amplified by the transistor and displayed by the indicator light.
[0018] The axial detection section employs a reflective photoelectric sensor. The axial photoelectric tube assembly 25 is vertically positioned along the bottom of the water tank 3, directly opposite the axial centerline of the steel pipe. The photoelectric tubes are arranged in a line with intervals between them. The detection signal emitted by each photoelectric tube is reflected by the outer wall of the spiral steel pipe 5 and then received by the photoelectric receiving tube. If there is an air leak, the escaping air bubbles will affect the signal reception of the receiving tube, causing an abnormal signal, which will then appear on the receiving tube. Since the photoelectric receiving tubes are evenly distributed along the water tank 2, the axial location of the air leak can be determined from the location of the receiving tube where the abnormal signal occurs. Thus, by using the radial and axial photoelectric tube assemblies in conjunction, the accurate location of the air leak in the steel pipe can be determined.
[0019] Furthermore, since the axial photoelectric sensor is located at the bottom of the water tank, its signal changes are not easily observed. Therefore, similar to setting up a radial signal display screen, as... Figure 7 As shown, the present invention includes an axial signal display screen 27, which can be placed in a convenient location for observation. The axial photoelectric sensor and the axial signal display screen are connected together by a signal line, so that the signal change of the axial photoelectric receiving tube is synchronized with the signal change of the indicator light on the axial signal display screen, and the abnormal signal of air leakage is displayed in real time.
[0020] The axial signal display screen has indicator lights L1-Ln, which are arranged in a row with intervals. Each indicator light corresponds to a 12m long steel pipe. If a 1m long axial signal display screen is installed, and the indicator lights are set at intervals of 2-3cm, then 30-50 indicator lights are needed to clearly display the signal changes, making it convenient for operators to make an immediate judgment on the axial location of the leak.
[0021] Furthermore, both axial and radial photoelectric sensors come into contact with water during operation, therefore, they must be waterproofed and sealed. This invention uses polymethyl methacrylate (acrylic or plexiglass) to encapsulate the photoelectric sensor, which has high light transmittance, good impact resistance, and does not affect the propagation and display of photoelectric signals.
[0022] In this invention, during leak detection, the spiral steel pipe 5 is first hoisted and placed on the rotating support 4. Then, the right airbag 9 and the left airbag 10 are placed in the inner cavities at both ends of the spiral steel pipe 5, respectively. The right sealing cap 7 and the left sealing cap 8 are installed in place by the pull rod 6. Marking lines are set on both the right sealing cap 7 and the left sealing cap 8. Note that the two marking lines should be aligned. Then, the first air pipe 15 is connected to the air source through the quick-connect connector to inflate the two airbags to seal the inner cavity of the steel pipe. Then, the inner cavity of the spiral steel pipe 5 is inflated through the second air pipe 17. After inflation, the connecting pipes of the two air pipes are disconnected. Then, the sliding seat 23 is moved to the left, and the three-jaw chuck assembly 14 clamps the spiral steel pipe 5. The motor 22 is started, driving the spiral steel pipe 5 to rotate slowly. If there is a leak, bubbles will appear. The photoelectric detection mechanism can locate the position of the bubbles around the circumference of the spiral steel pipe.
[0023] A drain pipe 20 and an inlet pipe 21 are provided on the water tank 2 for filling and draining water in the experiment.
[0024] Before the leak detection operation, both the right sealing cover 7 and the left sealing cover 8 are suspended from the upper crossbeam 1-1 by ropes 16, which facilitates the handling of the right sealing cover 7 and the left sealing cover 8 during the operation.
Claims
1. A device for detecting leakage defects in spiral steel pipes, characterized in that: The system includes a base frame (1), a water tank (2), water (3), a rotating support (4), a tie rod (6), a right sealing cap (7), a left sealing cap (8), a right airbag (9), a left airbag (10), an air pipeline (15), an air pipeline (17), a photoelectric detection mechanism, and a spiral steel pipe rotation drive mechanism. The water tank (2) is installed on the base frame (1). The rotating support (4) has two spaced-apart units, both of which are located in the water tank (2). The right airbag (9) is placed in the inner cavity of the right end of the spiral steel pipe (5), and the left airbag (10) is placed in the inner cavity of the left end of the spiral steel pipe (5). The right airbag (9) and the left airbag (10) are connected by the air pipeline (15). The right sealing cap (7) is located on one side of the right end of the spiral steel pipe (5) and serves to block the right airbag (9). The left sealing cap (8) is located on the left side of the spiral steel pipe (5) and serves to block the left airbag (10). The right sealing cap (7) and the left sealing cap (8) are tightened and fixed by two threaded pull rods (6) at both ends. The left end of the first air pipe (15) passes through the hole on the left sealing cap (8) and is connected to the air source through a quick-connect connector. The second air pipe (17) passes through the holes on the left airbag (10) and the left sealing cap (8) and is connected to the air source through a quick-connect connector. The spiral steel pipe rotation drive mechanism is installed on the base frame (1) and is used to drive the spiral steel pipe (5) to rotate. Pressurized gas is filled into the spiral steel pipe. The leak point is detected and located by a photoelectric detection mechanism. The water (3) in the water tank (2) is submerged in the lower quarter of the spiral steel pipe (5) in the vertical direction.
2. The spiral steel pipe leakage defect detection device according to claim 1, characterized in that: The spiral steel pipe rotation drive mechanism includes a three-jaw chuck assembly (14), a motor (22), a sliding seat (23), and a motor base (24). The motor base (24) is mounted on the base frame (1), and the sliding seat (23) is mounted on the motor base (24) in a way that allows it to move left and right. Limiting blocks are provided at both ends of the motor base (24). The motor (22) is fixedly mounted on the sliding seat (23). The three-jaw chuck assembly (14) clamps the spiral steel pipe (5), and the motor (22) drives the three-jaw chuck assembly (14) to rotate through the drive shaft.
3. The spiral steel pipe leakage defect detection device according to claim 1, characterized in that: The photoelectric detection mechanism includes a radial detection section and an axial detection section. The radial detection uses a through-beam phototube sensor, and the axial detection uses a reflective phototube sensor. The photoelectric emitter for radial detection is mounted on a radial photoelectric emitter disk (12), and each photoelectric emitter is powered by a first lithium battery (13) mounted on the radial photoelectric emitter disk (12). The photoelectric receiver for radial detection is mounted on a radial photoelectric receiver disk (11), and each photoelectric receiver is powered by a second lithium battery (19) mounted on the radial photoelectric receiver disk (11). The emitter of the photoelectric receiver is connected to the indicator control electrode mounted on the radial signal display screen (26). The control electrode is the base of transistor T1, and the collector of transistor T1 is connected to the power supply V+ via indicator D and the second resistor R2. Thus, when the signal of the photoelectric receiver changes, the signal of indicator D also changes. The photoelectric emitter and the photoelectric receiver for axial detection are both mounted on the axial phototube strip 25. Similar to the radial photoelectric detection principle, when air bubbles are generated along the axial direction, the signal of the photoelectric receiver changes, and the indicator L... The signal will indicate the change; the radial photoelectric receiving disk (11) and the second lithium battery (19) are installed on the left sealing cover (8), the radial photoelectric transmitting disk (12) and the first lithium battery (13) are installed on the right sealing cover (7), the line tube (18) is installed in the center of the left sealing cover (8), and the axial photoelectric tube strip (25) is provided at the bottom of the water tank (2).
4. The spiral steel pipe leakage defect detection device according to claim 1, characterized in that: A circular protrusion is provided on the right sealing cap (7) and the left sealing cap (8) on the side facing the spiral steel pipe (5), and the inner diameter of the circular protrusion corresponds to the outer diameter of the spiral steel pipe (5).
5. A spiral steel pipe leakage defect detection device according to claim 1, characterized in that: Both the right sealing cap (7) and the left sealing cap (8) are suspended from the upper crossbeam (1-1) by ropes (16).