Microwave resonance detection device for polyolefin pipeline hot melting joint
Through the microwave resonance detection device, the interaction between point focus antenna and resonant cavity is used to solve the shortcomings of the thermal welding joint detection defects of polyolefin pipelines, and the rapid and accurate detection of multiple polyolefin pipelines is achieved, providing independent intellectual property rights Detection method.
Patent Information
- Application Number
- CN202420769858.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-15
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2034-04-15
AI Technical Summary
The prior art lacks independent intellectual property rights in detecting defects of thermal welding joints in polyolefin pipelines, especially for detection methods for non-high-density polyethylene HDPE pipelines such as glass fiber reinforced homopolypolypropylene PPH and random copolymer polypropylene PPR pipelines. Less, relying on foreign technology and equipment.
Using microwave resonance detection device, combined with point-focusing antenna and resonant cavity, through the interaction between the near-field focusing beam and the structure of the area to be measured, small changes are mapped to resonant parameters, and defect location and size are determined, and S parameters are displayed in real time using vector network analyzer. curve, realize the detection of inclusions and hole defects.
It realizes fast and accurate detection of the thermal welding joint of polyolefin pipelines, high detection depth and resolution, no need for contact with pipes, simple operation, suitable for on-site inspection, and is suitable for various types of polyolefin pipelines.
Smart Images
Figure CN222280516U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of pressure pipeline detection, and in particular relates to a microwave resonance detection device for a polyolefin pipeline hot-melt joint. Background Art
[0002] Polyolefin pipes have many excellent properties, such as corrosion resistance, strong toughness, crack resistance, easy connection, excellent scratch resistance, etc. They have become the best choice for urban gas transmission pipelines and chemical equipment pipelines. The safe service of the pipeline system is closely related to the quality of pipeline welding and the performance of the joints. Hot melt connection and electric fusion connection are the main connection methods for polymer pipelines, among which hot melt connection is more widely used and suitable for the connection of polyolefin pipelines of various types and specifications. Ultrasonic, ray, microwave and other technologies are used at home and abroad to conduct non-destructive testing of hot melt joints of high-density polyethylene HDPE pipelines, but there are few related reports on other types of polyolefin pipelines, such as glass fiber reinforced homopolymer polypropylene PPH pipelines used by chemical companies for corrosive liquid transportation, random copolymer polypropylene PPR pipelines for water supply, etc. The defects in hot melt joints mainly include inclusions, holes, cold welding, etc. China lacks core technologies with independent intellectual property rights in the detection of hot melt joint defects and relies on foreign technologies and equipment. Summary of the invention
[0003] In view of the problems existing in the background technology, the purpose of the utility model is to provide a microwave resonance detection device for polyolefin pipe hot-melt joints, which combines the characteristics of large action depth of the focusing antenna and high detection sensitivity of the resonant cavity, and maps the slight changes in the structure and size of the test area to the changes in the resonant parameters of the microwave resonant cavity through its interaction with the near-field focused beam, thereby determining the location and size of the defect.
[0004] The purpose of the utility model can be achieved through the following technical solutions: A microwave resonance detection device for a polyolefin pipe hot-melt joint, comprising a point-focusing antenna, a resonant cavity, a positioning and scanning seat and a vector network analyzer, wherein the resonant cavity is fixed on the positioning and scanning seat, and the resonant cavity comprises two coupling ports, wherein one coupling port is connected to one end of the point-focusing antenna, and the other coupling port is connected to the vector network analyzer, and the other end of the point-focusing antenna is used to abut against the pipe to be tested for detection.
[0005] Preferably, the point focusing antenna includes a conical horn, one end of which is a horn mouth, and a dielectric lens is arranged at the horn mouth; the other end of the conical horn is a feeding port, and the feeding port is connected to the coupling port of the resonant cavity through a rectangular waveguide.
[0006] Preferably, the conical horn is a pyramid horn, and the rectangular waveguide is directly connected to a feeding port of the pyramid horn.
[0007] Preferably, the conical horn is a conical horn, and the rectangular waveguide is connected to the feeding port of the conical horn through a rectangular-circular transition.
[0008] Preferably, the resonant cavity is rectangular or cylindrical in shape, the resonant frequency of the resonant cavity is 8-40 GHz, and the quality factor is ≥2000.
[0009] Preferably, the scanning direction of the positioning and scanning seat includes two directions along the circumference and axial direction of the pipeline to be measured. A laser locator is installed on the positioning and scanning seat, and the laser locator is used to record the coordinate position of the point focusing antenna in the circumference and axial directions of the pipeline to be measured.
[0010] Preferably, the coupling port of the resonant cavity is connected to the vector network analyzer via a microwave cable.
[0011] Compared with the prior art, the utility model has the following advantages:
[0012] 1. The microwave resonance detection device of the utility model can detect the pipeline hot-melt joint without contacting the polyolefin pipeline to be tested. The detection device is simple and easy to install and operate, and is suitable for on-site in-situ detection.
[0013] 2. The microwave resonance detection device of the utility model can resonate and amplify the signal reflected by the sample to be tested in the resonance cavity, thereby ensuring the depth and resolution of the detection at the same time and having high detection sensitivity.
[0014] 3. The utility model can realize accurate and rapid detection of inclusions and hole defects in polyolefin pipe hot-melt joints. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 This is a schematic diagram of a microwave resonance detection device for polyolefin pipe hot-melt joints of the utility model.
[0016] Figure 2 S parameter curves obtained for detecting normal HDPE pipe hot melt joints without defects and those with inclusion defects of different sizes.
[0017] Figure 3 S parameter curves obtained for detecting normal HDPE pipe hot melt joints without defects and those with holes of different sizes.
[0018] Figure 4 S parameter curves obtained for testing normal PPH pipe hot melt joints without defects and with holes of different sizes.
[0019] In the figure, 1. Vector network analyzer; 2. Positioning and scanning seat; 3. Resonant cavity; 4. Point focusing antenna; 5. Pipeline to be tested; 6. Microwave cable. DETAILED DESCRIPTION
[0020] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.
[0021] like Figure 1 As shown, this embodiment provides a microwave resonance detection device for hot-melt joints of polyolefin pipes, which can be applied to defect detection of polyolefin pipes such as HDPE, PPH, and PPR. The device includes a point-focusing antenna 4, a resonant cavity 3, a positioning and scanning seat 2, and a vector network analyzer 1. The resonant cavity 3 can be rectangular or cylindrical, and the resonant cavity 3 includes two coupling ports, one of which is connected to the point-focusing antenna 4 through a rectangular waveguide, and the other coupling port is connected to the vector network analyzer 1 through a microwave cable 6. The point-focusing antenna 4 includes a pyramidal horn, one end of the pyramidal horn is a horn mouth, and a dielectric lens is installed at the horn mouth; the other end is a feeding port. The feeding port is connected to the rectangular waveguide and thus connected to the resonant cavity 3. The resonant frequency of the resonant cavity 3 is between 8-40 GHz, and the quality factor is ≥2000. The scanning directions of the positioning and scanning seat 2 include the circumferential direction and the axial direction of the pipeline 5 to be tested. A laser locator is installed on the positioning and scanning seat 2. The laser locator is used to record the coordinate position of the point focusing antenna 4 in the circumferential direction (hereinafter referred to as the φ direction) and the axial direction (hereinafter referred to as the z direction) of the pipeline 5 to be tested.
[0022] It should be noted that, in other embodiments of the present invention, the pyramid horn may be replaced by a conical horn, and a rectangular-circular transition may be used to connect the rectangular waveguide and the feeding port of the conical horn.
[0023] The following is a comparison of the different results obtained by using the microwave resonance detection device of the present invention to detect HDPE pipe hot melt joints or PPH pipe hot melt joints that are usually defect-free and contain inclusion defects and hole defects of different sizes, so as to illustrate the use principle and effect of the microwave resonance detection device of the present invention. The specific operation is as follows:
[0024] 1. Place the positioning and scanning seat 2 loaded with the point-focusing antenna 4 and the resonant cavity 3 on the outer surface of the HDPE pipe to be tested, so that the lifting distance between the bell mouth of the point-focusing antenna 4 and the outer surface of the pipe is equal to the focus of the antenna; keep the lifting distance unchanged, and make the point-focusing antenna 4 perform two-dimensional scanning along the φ direction and the z direction, with a scanning speed of 20 mm per second; during the scanning process, the vector network analyzer 1 connected to the point-focusing antenna 4 and the resonant cavity 3 displays the S parameters in real time, and the laser locator displays the location of the defect, which is expressed in two-dimensional coordinates (φ, z). The test results of three different HDPE pipe hot-melt joints are shown in Figure 1. Figure 2 As shown. For the hot melt joint with 2 mm talcum powder particles, when the point focusing antenna 4 scans to the position where the defect is located, the peak value of the S parameter curve is increased compared with the normal non-defective hot melt joint; for the hot melt joint with 3 mm talcum powder particles, when the point focusing antenna 4 scans to the position where the defect is located, the peak value of the S parameter curve is larger than that of the hot melt joint with 2 mm talcum powder particles. Therefore, the microwave resonance detection method can detect the inclusion defects in the HDPE pipe hot melt joint, and can determine the location and relative size of the defects.
[0025] 2. Place the positioning and scanning seat 2 loaded with the point-focusing antenna 4 and the resonant cavity 3 on the outer surface of the HDPE pipe to be tested, so that the lifting distance between the bell mouth of the point-focusing antenna 4 and the outer surface of the pipe is equal to the focus of the antenna; keep the lifting distance unchanged, and make the point-focusing antenna 4 perform two-dimensional scanning along the φ direction and the z direction, with a scanning speed of 10 mm per second; during the scanning process, the vector network analyzer 1 connected to the point-focusing antenna 4 and the resonant cavity 3 displays the S parameters in real time, and the laser locator displays the location of the defect, expressed in two-dimensional coordinates (φ, z). The test results of three different HDPE pipe hot-melt joints are shown in Figure 2. Figure 3 As shown. For the hot melt joint with 1 mm hole, when the point focusing antenna 4 scans to the position where the defect is located, the peak value of the S parameter curve is reduced compared with the normal non-defective hot melt joint; for the hot melt joint with 2 mm hole, when the point focusing antenna 4 scans to the position where the defect is located, the peak value of the S parameter curve is smaller than that of the hot melt joint with 1 mm hole. Therefore, the microwave resonance detection method can detect the hole defect in the hot melt joint of HDPE pipe, and can determine the position and relative size of the defect.
[0026] 3. Place the positioning and scanning seat 2 loaded with the point focusing antenna 4 and the resonant cavity 3 on the outer surface of the PPH pipe to be tested, so that the lifting distance between the bell mouth of the point focusing antenna 4 and the outer surface of the pipe is equal to the focus of the antenna; keep the lifting distance unchanged, and make the point focusing antenna 4 perform two-dimensional scanning along the φ direction and the z direction, with a scanning speed of 15 mm per second; during the scanning process, the vector network analyzer 1 connected to the point focusing antenna 4 and the resonant cavity 3 displays the S parameters in real time, and the laser locator displays the location of the defect, which is expressed in two-dimensional coordinates (φ, z). The test results of three different PPH pipe hot-melt joints are shown in Figure 2. Figure 4As shown. For the hot melt joint with a 2 mm hole, when the point focusing antenna 4 scans to the position where the defect is located, the peak value of the S parameter curve is reduced compared with the normal non-defective hot melt joint; for the hot melt joint with a 3 mm hole, when the point focusing antenna 4 scans to the position where the defect is located, the peak value of the S parameter curve is smaller than that of the hot melt joint with a 2 mm hole. Therefore, the microwave resonance detection method can detect the hole defect in the PPH pipe hot melt joint, and can determine the position and relative size of the defect.
[0027] The microwave resonance detection device provided by the utility model can well detect defects of polyolefin pipeline hot-melt joints such as HDPE pipe hot-melt joints and PPH pipe hot-melt joints. It is easy to use and has accurate detection results. It has good practicality and strong applicability, and has good promotion and use value.
[0028] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.
Claims
1. A microwave resonance detection device for polyolefin pipe hot-melt joints, characterized in that: The invention comprises a point focusing antenna (4), a resonant cavity (3), a positioning and scanning seat (2) and a vector network analyzer (1), wherein the resonant cavity (3) is fixed on the positioning and scanning seat (2), the resonant cavity (3) comprises two coupling ports, one of which is connected to one end of the point focusing antenna (4), and the other is connected to the vector network analyzer (1), and the other end of the point focusing antenna (4) is used to abut against a pipeline to be tested (5) for detection.
2. The microwave resonance detection device for a polyolefin pipe hot-melt joint according to claim 1, characterized in that: The point focusing antenna (4) comprises a conical horn, one end of which is a horn mouth, and a dielectric lens is arranged at the horn mouth; the other end of which is a feeding port, and the feeding port is connected to the coupling port of the resonant cavity (3) through a rectangular waveguide.
3. The microwave resonance detection device for a polyolefin pipe hot-melt joint according to claim 2, characterized in that: The conical horn is a pyramid horn, and the rectangular waveguide is directly connected to the feeding port of the pyramid horn.
4. The microwave resonance detection device for a polyolefin pipe hot-melt joint according to claim 2, characterized in that: The conical horn is a conical horn, and the rectangular waveguide is connected to the feeding port of the conical horn through a rectangular-circular transition.
5. A microwave resonance detection device for a polyolefin pipe hot-melt joint according to claim 1, 2, 3 or 4, characterized in that: The shape of the resonant cavity (3) is rectangular or cylindrical, the resonant frequency of the resonant cavity (3) is 8-40 GHz, and the quality factor is ≥2000.
6. A microwave resonance detection device for a polyolefin pipe hot-melt joint according to claim 1, 2, 3 or 4, characterized in that: The scanning direction of the positioning and scanning seat (2) includes two directions: the circumferential direction and the axial direction of the pipeline (5) to be tested. A laser locator is installed on the positioning and scanning seat (2). The laser locator is used to record the coordinate position of the point focusing antenna (4) in the circumferential direction and the axial direction of the pipeline (5) to be tested.
7. A microwave resonance detection device for a polyolefin pipe hot-melt joint according to claim 1, 2, 3 or 4, characterized in that: The coupling port of the resonant cavity (3) is connected to the vector network analyzer (1) via a microwave cable (6).