Pulsed eddy current detection unit and device for sle type linear quench heat exchanger
By using a pulsed eddy current detection unit at the outer jacket tube of the SLE type linear quench heat exchanger, the detection problem caused by the small gap between the jacket tubes was solved, and rapid and accurate detection of defects in the inner tube was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- GUANGDONG INST OF SPECIAL EQUIP INSPECTION
- Filing Date
- 2025-04-03
- Publication Date
- 2026-05-29
AI Technical Summary
In the existing technology, the jacket tube spacing of the SLE type linear quench heat exchanger is too small, making it difficult to detect defects in the inner tubes by X-ray.
The pulsed eddy current detection unit includes a first housing, a probe, a connecting rod, and a control system. Multiple housings are connected in series via the connecting rod. Pulsed eddy current technology is used to identify pipe deformation or weld defects, and corrosion thinning and overheating deformation of the inner pipe are detected directly at the outer jacket.
It enables rapid qualitative scanning of the inner tube, effectively detects defects in the inner tube in confined spaces, overcomes the detection problem of excessively small gaps between jacketed tubes, and improves detection sensitivity and accuracy.
Smart Images
Figure CN224303629U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of pulsed eddy current nondestructive testing technology, and in particular to a pulsed eddy current testing unit and device for an SLE type linear quench heat exchanger. Background Technology
[0002] Linear quench heat exchangers are key equipment in modern petrochemical ethylene production plants. They can rapidly cool high-temperature cracked gas (around 800°C) to below 550°C, reducing the loss of olefin products. They can also recover high-grade heat energy for secondary use to reduce energy consumption. They have advantages such as improving ethylene recovery efficiency and are the waste heat recovery method for most ethylene production plants in China.
[0003] The service status of the SLE type linear quench heat exchanger is related to the normal operation of the ethylene cracking unit. In the existing technology, when the SLE type linear quench heat exchanger is shut down and cleaned, the user often uses digital radiography to check whether the inner tube is overheated and deformed. Although digital radiography can detect weld defects in the inner tube of the jacket, the spacing between the jacket tubes of the linear quench heat exchanger is extremely small, and due to spatial limitations, it is difficult to carry out radiography. Utility Model Content
[0004] The purpose of this utility model is to solve at least one of the technical problems existing in the prior art. To this end, this utility model proposes a pulse eddy current detection unit and device for SLE type linear quench heat exchanger, which can directly detect defects in the inner tube of the outer jacket tube of the SLE type linear quench heat exchanger, effectively overcoming the problem that the detection is difficult to implement due to the small distance between the jacket tubes.
[0005] According to an embodiment of the first aspect of this utility model, the SLE type linear quench heat exchanger pulse eddy current detection unit includes a first housing with a detachable end cover for convenient maintenance and repair of the interior of the first housing; a second housing disposed on the first housing; at least one connecting rod, with at least one connecting rod provided on two opposite end faces of the first housing, the connecting rod extending away from the first housing, and the connecting rod for connecting two adjacent first housings; a probe disposed on the end cover and located in the first housing, the probe for scanning the inner tube of the jacket; and a control system connected to the probe, the control system for data acquisition and analysis.
[0006] The pulse eddy current detection unit for the SLE-type linear quench heat exchanger according to the present invention has at least the following beneficial effects: multiple first shells are connected in series by connecting rods to adapt to the detection requirements of heat exchanger tube bundles of different diameters. Pulse eddy current technology is used to identify tube deformation or weld defects. It can not only perform in-service inspection of the inner tubes of the SLE-type linear quench heat exchanger, but also quickly and qualitatively scan for local corrosion, overheating deformation and mechanical damage of the inner tubes. The detection device can directly detect defects such as corrosion thinning and overheating deformation of the inner tubes at the outer jacket tube of the SLE-type linear quench heat exchanger, thereby effectively overcoming the problem that the detection is difficult to implement due to the small spacing between the jacket tubes.
[0007] According to some embodiments of the present invention, the probe includes an excitation coil and two receiving coils. The excitation coil and the two receiving coils are both located in a first housing. The two receiving coils are both located within the range limited by the excitation coil. The excitation coil is connected to the control system through a signal excitation line, and the receiving coils are connected to the control system through a signal receiving line.
[0008] According to some embodiments of this utility model, the excitation coil is elliptical and the receiving coil is circular.
[0009] According to some embodiments of this utility model, the first shell is made of high-temperature resistant reinforced rubber shell of tetrafluoroethylene-ethylene copolymer.
[0010] According to some embodiments of the present invention, the extension direction of the connecting rod is perpendicular to the connection surface between the connecting rod and the first housing.
[0011] According to some embodiments of this utility model, the maximum height ratio of the excitation coil to the receiving coil is 5:8.
[0012] According to some embodiments of this utility model, the frame of the excitation coil is an elliptical iron-based amorphous alloy.
[0013] According to some embodiments of this utility model, the major axis length of the excitation coil ranges from 90mm to 115mm, and the minor axis length of the excitation coil ranges from 40mm to 50mm.
[0014] According to some embodiments of this utility model, the center-to-center distance between the two receiving coils is 30mm to 50mm.
[0015] According to the second aspect of the present invention, the SLE type linear quench heat exchanger pulse eddy current detection device employs an SLE type linear quench heat exchanger pulse eddy current detection unit, which includes multiple SLE type linear quench heat exchanger pulse eddy current detection units connected sequentially along the circumference of the jacket tube. Two adjacent SLE type linear quench heat exchanger pulse eddy current detection units are connected by two adjacent connecting rods, and the multiple SLE type linear quench heat exchanger pulse eddy current detection units cover half the circumference of the jacket tube.
[0016] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description
[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments;
[0018] Figure 1 This is a front view of an SLE type linear quench heat exchanger.
[0019] Figure 2 This is a side view of an SLE type linear quench heat exchanger.
[0020] Figure 3 This is a schematic diagram of the pulse eddy current detection unit of the SLE type linear quench heat exchanger according to an embodiment of the present invention;
[0021] Figure 4 for Figure 3 Top view in the middle;
[0022] Figure 5 for Figure 2 A schematic diagram of the structure of the excitation coil inside the first housing.
[0023] Figure 6 This is a schematic diagram of the structure of the pulse eddy current detection device for the SLE type linear quench heat exchanger according to an embodiment of the present invention.
[0024] Figure label:
[0025] First shell 100;
[0026] Second housing 200, through hole 210;
[0027] Connecting rod 300;
[0028] Probe 400, excitation coil 410, signal excitation line 411, frame 412, receiving coil 420, signal receiving line 421;
[0029] Control system 500;
[0030] Jacketed tube 10, inner jacket tube 11, outer jacket tube 12. Detailed Implementation
[0031] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0032] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If the description mentions "first" or "second," it is merely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or the sequential relationship between indicated technical features.
[0033] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.
[0034] refer to Figures 1 to 6 This embodiment discloses a pulse eddy current detection unit for an SLE type linear quench heat exchanger.
[0035] like Figures 1 to 6 As shown, the SLE type linear quench heat exchanger pulse eddy current detection unit includes a first housing 100, on which a detachable end cover is provided for convenient maintenance and repair of the interior of the first housing 100; a second housing 200, which is disposed on the first housing 100; at least one connecting rod 300, which is provided at least at one location on two opposite end faces of the first housing 100, and extends in a direction away from the first housing 100, for connecting two adjacent first housings 100; a probe 400, which is disposed on the end cover and located in the first housing 100, for scanning the jacket tube; and a control system 500, which is connected to the probe 400 and is used for data acquisition and analysis.
[0036] It should be noted that, typically, when the SLE type linear quench heat exchanger is in a shutdown and descaling state, the user usually uses a high-definition endoscope to insert into the inner tube for observation to further explore whether there is overheating deformation. However, due to the presence of coking material inside the inner tube, endoscopic observation has significant limitations. Digital radiographic testing is a proven method for detecting defects in the weld seams of jacketed pipes, such as... Figure 1 and Figure 2 As shown in the schematic diagram of the SLE type linear quench heat exchanger, unlike the normally independently set jacketed tubes 10, the spacing between each jacketed tube 10 in the linear quench heat exchanger is generally only 250mm. Therefore, due to the limited space, it is difficult to carry out X-ray inspection.
[0037] like Figure 3 and Figure 4 In the illustrated embodiment, the rear end of the first housing 100 is provided with a detachable end cap, and the front end is provided with a second housing 200. Two connecting rods 300 are respectively provided at the left and right ends of the first housing 100, and the end of the connecting rod 300 away from the first housing 100 is provided with a connecting hole. The probe 400 is located inside the first housing 100 and can be connected to an external control system 500. Thus, multiple first housings 100 are connected in series by the connecting rods 300 to meet the inspection requirements of heat exchanger tube bundles of different diameters. The pulsed eddy current technology is used to identify tube deformation or weld defects. This not only enables in-service inspection of the inner tubes of the SLE type linear quench heat exchanger, but also allows for rapid qualitative scanning of local corrosion, overheating deformation, and mechanical damage of the inner tubes. This allows the inspection device to directly detect defects such as corrosion thinning and overheating deformation of the inner tubes at the outer jacket tube 10 of the SLE type linear quench heat exchanger, thereby effectively overcoming the problem that the small spacing between the jacket tubes 10 makes inspection difficult.
[0038] Specifically, the first shell 100, the second shell 200, and the connecting rod 300 are 3D printed integrated structures.
[0039] Specifically, the connecting holes on the connecting rod 300 are arranged along the length of the connecting rod 300 to ensure that the coaxiality and spacing controllability of the multiple first housings 100 when connected in series.
[0040] Furthermore, considering both spatial adaptability and detection accuracy, the side of the first housing 100 closest to the jacket tube adopts an arc shape design. Specifically, since the spacing between the jacket tubes 10 of the SLE-type linear quench heat exchanger is extremely small, the arc structure can closely fit the outer wall contour of the inner tube, ensuring that the probe 400 maintains the optimal detection distance with the tube surface being measured, and avoiding attenuation of the eddy current signal due to excessive gap. At the same time, the radius of curvature of the arc surface is usually matched with the outer diameter of the inner tube, and the mechanical guiding action keeps the first housing 100 stable when rotating or moving axially, reducing the interference of shaking on the scanning results.
[0041] In some specific embodiments of this utility model, the probe 400 includes an excitation coil 410 and two receiving coils 420. The excitation coil 410 and the two receiving coils 420 are both located in the first housing 100. The two receiving coils 420 are both located within the range limited by the excitation coil 410. The excitation coil 410 is connected to the control system 500 through a signal excitation line 411, and the receiving coils 420 are connected to the control system 500 through a signal receiving line 421.
[0042] like Figure 5 and Figure 6 As shown, the first housing 100 is equipped with an elliptical racetrack-shaped probe 400. The probe 400 is composed of an excitation coil 410 and two receiving coils 420. The excitation coil 410 is connected to a signal excitation line 411, and the receiving coils 420 are connected to a signal receiving line 421. The signal excitation line 411 and the signal receiving line 421 are connected to the ports of each detection device and the control system 500 through a through hole 210 provided at the top of the second housing 200.
[0043] In some specific embodiments of this invention, the excitation coil 410 is elliptical, and the receiving coil 420 is circular. The elliptical design of the excitation coil 410 generates a more directional electromagnetic field, causing eddy currents to preferentially distribute along a specific direction within the tube wall, thereby improving the detection sensitivity for defects with specific orientations. The circular design of the receiving coil 420 allows for the uniform reception of attenuated eddy current signals from different directions, ensuring comprehensive detection. By analyzing the correlation between the directional excitation of the excitation coil 410 and the omnidirectional response of the receiving coil 420, the control system 500 can more accurately identify the geometric features of defects and distinguish between different types of damage modes, thereby effectively improving the stability of the pulsed eddy current structure and the sensitivity of defect detection.
[0044] In some specific embodiments of this utility model, the first housing 100 is made of high-temperature resistant reinforced rubber made of tetrafluoroethylene-ethylene copolymer. It should be noted that the high-temperature resistant reinforced rubber material of tetrafluoroethylene-ethylene copolymer has excellent heat resistance, insulation, and mechanical toughness, and can maintain stable performance in high-temperature environments, preventing the housing from softening or deforming due to prolonged contact with the high-temperature pipe wall. Simultaneously, this material has excellent electrical insulation, effectively isolating electromagnetic interference between the excitation coil 410 and the receiving coil 420, ensuring the purity of the detection signal.
[0045] In some specific embodiments of this utility model, the extension direction of the connecting rod 300 is perpendicular to the connection surface between the connecting rod 300 and the first housing 100, so as to ensure that multiple first housings 100 can maintain coaxiality and straightness when assembled in series, avoid misalignment of the probe 400 or detection blind zone caused by angular deviation, and the rigid structure of the connecting rod 300 can withstand axial pushing and pulling forces, so that the detection unit can move stably in the narrow space between tubes.
[0046] In some specific embodiments of this utility model, the maximum height ratio of the excitation coil 410 to the receiving coil 420 is 5:8.
[0047] In some specific embodiments of this utility model, based on its unique electromagnetic properties and mechanical performance advantages, the frame 412 of the excitation coil 410 is an elliptical iron-based amorphous alloy. The iron-based amorphous alloy has extremely high permeability and extremely low coercivity, enabling efficient conduction and focusing of the transient pulse magnetic field generated by the excitation coil 410, significantly improving magnetic field strength and directional control. Furthermore, its elliptical structure can further optimize the magnetic field distribution, allowing eddy currents to form a directional enhancement effect in the tube wall, which is beneficial for detecting axial or circumferential linear defects.
[0048] In some specific embodiments of this utility model, the major axis length of the excitation coil 410 ranges from 90mm to 115mm, and the minor axis length of the excitation coil 410 ranges from 40mm to 50mm.
[0049] In some specific embodiments of this utility model, the center-to-center distance between the two receiving coils 420 is 30mm to 50mm.
[0050] refer to Figure 6 This embodiment discloses an SLE type linear quench heat exchanger pulse eddy current detection device, which includes multiple SLE type linear quench heat exchanger pulse eddy current detection units connected sequentially along the circumference of the jacket tube. Two adjacent SLE type linear quench heat exchanger pulse eddy current detection units are connected by two adjacent connecting rods 300. The multiple SLE type linear quench heat exchanger pulse eddy current detection units cover half the circumference of the jacket tube.
[0051] Specifically, such as Figure 6As shown, during assembly, two adjacent SLE type linear quench heat exchanger pulse eddy current detection units are assembled and fixed by adding hexagonal connecting bolts through the through hole 210 on the outside of the connecting rod 300. Each first housing 100 is equipped with an elliptical racetrack-shaped probe 400. The probe 400 is fixed to the inside of the end cover by heat fusion connection for easy maintenance and repair. The probe 400 includes an excitation coil 410 and a receiving coil 420. The excitation coil 410 is connected to a signal excitation line 411, and the receiving coil 420 is connected to a signal receiving line 421. The signal excitation line 411 and the signal receiving line 421 are led out through four through holes 210 provided on the second housing 200. The excitation line input end of the first SLE-type linear quench heat exchanger pulse eddy current detection unit is connected to the excitation signal output port of the control system 500, and the receiving line output end of the last SLE-type linear quench heat exchanger pulse eddy current detection unit returns to the data acquisition port of the control system 500, forming a closed detection loop. The signal excitation line 411 output end of each SLE-type linear quench heat exchanger pulse eddy current detection unit is connected to the signal excitation line 411 input end of the adjacent SLE-type linear quench heat exchanger pulse eddy current detection unit, and the receiving line is connected in the same way, thus forming a series link to ensure that all SLE-type linear quench heat exchanger pulse eddy current detection units are synchronously driven by the same control system 500.
[0052] The application of this SLE-type linear quench heat exchanger pulse eddy current detection device will be illustrated below through a specific embodiment.
[0053] The first housing 100 is rectangular in shape, with a detachable end cap at its rear end. Both ends of the end cap have threaded holes for fixed connection with the first housing 100. The first housing 100, connected to the end cap, forms an arc shape matching the jacketed tube. A second housing 200, integrally formed by 3D printing, is located at the front end of the first housing 100. The second housing 200 has four through holes 210 for leading wires. Connecting rods 300 integrally formed by 3D printing are installed at both ends of the first housing 100. The end of the connecting rod 300 away from the first housing 100 has a threaded hole. Adjacent first housings 100 are fixedly connected by hexagonal bolts via the connecting rods 300. An elliptical racetrack-shaped probe 400 is installed inside the first housing 100. The probe 400 consists of an excitation coil 410 and two receiving coils 420. The excitation coil 410 is connected to a signal excitation line 411, and the receiving coils 420 are connected to a signal receiving line 421. The signal excitation line 411 and the signal receiving line 421 are connected to the pulse eddy current detection units of each SLE type linear quench heat exchanger and the port of the control system 500 through through holes 210 provided in the second housing 200. Through experimental verification, the recommended major axis length of the elliptical iron-based amorphous alloy skeleton 412 in the excitation coil 410 is 90mm to 115mm, and the minor axis length is 40mm to 50mm. The recommended maximum height ratio of the excitation coil 410 to the receiving coil 420 is 5:8. The receiving coil 420 should preferably adopt a cylindrical skeleton 412 structure, and the spacing between the center points is recommended to be 30mm-50mm.
[0054] A pulse eddy current testing instrument of model NCHGPEC-01 was selected as the control system 500. Five SLE-type linear quench heat exchanger pulse eddy current testing units were assembled in series. During use, the outer jacket tube 10 of the SLE-type linear quench heat exchanger was partially disassembled to determine the sampling range. Then, the SLE-type linear quench heat exchanger pulse eddy current testing device was placed over half of the outer jacket tube 10. The inner tube was quickly scanned by moving it up and down or rotating it circumferentially. It is important to note that the step speed of the testing device should be controlled at 300 mm / s. After completing one half-circle scan, the other half of the outer jacket tube 10 of the SLE-type linear quench heat exchanger was then scanned.
[0055] Because the pulse eddy current detection unit for the SLE-type linear quench heat exchanger is small in size, it is not affected by the small spacing between the jacketed tubes 10 during testing. It allows for tube-by-tube inspection of the inner tubes, enabling a rapid, one-time scan of large-area corrosion thinning and overheating depressions in the inner tubes of the SLE-type linear quench heat exchanger. Furthermore, the five-unit array imaging effectively improves detection sensitivity, offering advantages such as high sensitivity, small size and weight, easy installation and portability, no need for coupling agent, and environmental friendliness.
[0056] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.
Claims
1. A pulsed eddy current detection unit for an SLE-type linear quench heat exchanger, characterized in that, include: A first housing (100) is provided with a detachable end cap, which is used to facilitate maintenance and repair inside the first housing (100); A second housing (200) is disposed on the first housing (100); At least one connecting rod (300) is provided at least at one location on two opposite end faces of the first housing (100), the connecting rod (300) extends in a direction away from the first housing (100), and the connecting rod (300) is used to connect two adjacent first housings (100); The probe (400) is disposed on the end cap and is located in the first housing (100). The probe (400) is used to scan the jacket tube (10). A control system (500) is connected to the probe (400) and is used for data acquisition and analysis.
2. The SLE-type linear quench heat exchanger pulse eddy current detection unit according to claim 1, characterized in that, The probe (400) includes an excitation coil (410) and two receiving coils (420). The excitation coil (410) and the two receiving coils (420) are both located in the first housing (100). The two receiving coils (420) are both located within the range limited by the excitation coil (410). The excitation coil (410) is connected to the control system (500) via a signal excitation line (411), and the receiving coils (420) are connected to the control system (500) via a signal receiving line (421).
3. The SLE-type linear quench heat exchanger pulse eddy current detection unit according to claim 2, characterized in that, The excitation coil (410) is elliptical, and the receiving coil (420) is circular.
4. The pulse eddy current detection unit for the SLE type linear quench heat exchanger according to claim 3, characterized in that, The first housing (100) is made of high-temperature resistant reinforced rubber shell of tetrafluoroethylene-ethylene copolymer.
5. The SLE-type linear quench heat exchanger pulse eddy current detection unit according to claim 2, characterized in that, The extension direction of the connecting rod (300) is perpendicular to the connection surface between the connecting rod (300) and the first housing (100).
6. The SLE-type linear quench heat exchanger pulse eddy current detection unit according to claim 5, characterized in that, The maximum height ratio of the excitation coil (410) to the receiving coil (420) is 5:
8.
7. The SLE-type linear quench heat exchanger pulse eddy current detection unit according to claim 2, characterized in that, The frame (412) of the excitation coil (410) is an elliptical iron-based amorphous alloy.
8. The SLE-type linear quench heat exchanger pulse eddy current detection unit according to claim 2, characterized in that, The major axis length of the excitation coil (410) ranges from 90 mm to 115 mm, and the minor axis length of the excitation coil (410) ranges from 40 mm to 50 mm.
9. The SLE-type linear quench heat exchanger pulse eddy current detection unit according to claim 2, characterized in that, The center-to-center distance between the two receiving coils (420) is 30 mm to 50 mm.
10. A pulse eddy current detection device for an SLE-type linear quench heat exchanger, employing the pulse eddy current detection unit for an SLE-type linear quench heat exchanger as described in any one of claims 1 to 9, characterized in that, The system includes multiple SLE-type linear quench heat exchanger pulse eddy current detection units connected sequentially along the circumference of the jacket tube (10). Two adjacent SLE-type linear quench heat exchanger pulse eddy current detection units are connected by two adjacent connecting rods (300). The multiple SLE-type linear quench heat exchanger pulse eddy current detection units cover half the circumference of the jacket tube (10).