Connector and connecting method for basalt polyethylene composite pipe

Abstract

The application discloses a connecting piece and a connecting method based on basalt polyethylene composite pipes, relates to the field of pipelines, and comprises a fixing piece in a tubular structure and an induction heating structure. The fixing piece comprises, from outside to inside, a first polyethylene layer, a first metal layer and a second polyethylene layer. The two ends of the fixing piece are used for sleeving in the connecting ends of two basalt polyethylene composite pipes respectively, and the outer diameter of the fixing piece is greater than or equal to the inner diameters of the connecting ends of the two basalt polyethylene composite pipes. The induction heating structure is located outside the two basalt polyethylene composite pipes and is used for heating the first metal layer. After the structure is connected, the basalt polyethylene composite pipes have better strength, density and pressure resistance. Meanwhile, the inner walls of the basalt polyethylene composite pipes are kept smooth, and the flow area is not affected.

Description

Technical Field

[0001] This invention relates to the field of pipelines, and more specifically to connectors and connection methods based on basalt polyethylene composite pipes. Background Technology

[0002] Basalt fiber is a continuous fiber produced by melting basalt rock at 1450℃~1500℃ and then drawing it at high speed through a platinum-rhodium alloy spinneret. Basalt continuous fiber not only has high strength but also possesses a variety of excellent properties such as electrical insulation, corrosion resistance, and high-temperature resistance. Polyethylene composite pipes made from basalt fiber exhibit higher strength, chemical and thermal stability, acid and alkali resistance, UV resistance, and moisture absorption than metals and glass fibers.

[0003] However, the connection method of basalt fiber polyethylene composite pipes has become a problem for the industry. This is because basalt fiber polyethylene composite pipes contain basalt fiber layers, and the melting temperature of basalt fibers is 1450℃-1500℃, so butt welding cannot be used. Therefore, the existing connection methods for basalt fiber composite pipes are as follows:

[0004] The slotted joint method involves installing an annular slot at the end of the basalt fiber composite pipe. When connecting two pipes, two semi-circular connectors are fastened at the joint, and then bolted together. The semi-circular protrusions of the connectors engage with the slots in the pipes, thus achieving the connection. This method is prone to leakage at the semi-circular connector joints, failing to guarantee the pipe's seal. Furthermore, the basalt fiber composite pipe joints are more susceptible to leakage under external impact.

[0005] Hot-melt socket connection method: The pipe ends should be chamfered. Clean the pipe and fitting connection surfaces with a clean cotton cloth, and mark the insertion depth on the spigot end. Then, use a hot-melt socket connection tool to heat the outer surface of the spigot and the inner surface of the socket. After heating, immediately remove the heating tool and use uniform external force to insert the spigot to the marked depth on the socket, forming a uniform flange at the socket end. However, this type of socket fitting has limited pressure resistance and cannot be used in high-pressure pipelines. It loses the characteristics of basalt fiber polyethylene composite pipes, and the ends of basalt fiber polyethylene composite pipes cannot be sealed, causing secondary water pollution due to the basalt fiber.

[0006] Electrofusion connection: An electrofusion fitting is fitted onto the pipe and fitting itself. Heat generated by energizing a resistance wire embedded in the inner surface of the fitting melts the inner surface of the fitting and the outer surface of the pipe to which it rests, fusing them together. This method is difficult to achieve with precise welding in outdoor climates and windy conditions. High-quality joints require careful design of the fitting structure and precise control of input power and energizing time. The entire process demands high precision, is difficult to implement, and has low efficiency. Furthermore, the introduction of electrofusion fittings increases the connection cost, and the required dimensions of the connecting pipe sections must be the same as those for butt fusion. In addition, the oxide scale on the surfaces to be welded must be scraped off before welding, making the process cumbersome.

[0007] Flange connection: For flange (back-pressure loose flange) connection of Wuyan fiber polyethylene pipe, first, slip the flange (back-pressure loose flange) onto the end of the polyethylene flange connector (heel-shaped pipe end) to be connected, and then connect the plain end of the flange connector (heel-shaped pipe end) to the pipe according to the requirements of heat fusion or electrofusion connection. Because the inner and outer diameters of Wuyan fiber polyethylene pipe and metal pipe are not compatible, and their wall thicknesses are also different, a double-flange short pipe is required. Ensuring that the flange dimensions of the metal pipe and the Wuyan fiber polyethylene pipe are consistent is crucial to guarantee a proper and standardized flange connection, but this method is costly and difficult to implement.

[0008] In summary, existing basalt fiber polyethylene composite pipe connection methods have many problems, are difficult to implement, inefficient, costly, and have poor practicality. Summary of the Invention

[0009] One object of the present invention is to provide a connector based on basalt polyethylene composite pipe, which can quickly and firmly connect two basalt polyethylene composite pipes through a fastener, and is applicable to both high-pressure and low-pressure composite pipes, and has good strength and compressive strength.

[0010] Another objective of this invention is to provide a connection method based on basalt polyethylene composite pipes, which, when applied to the above-mentioned connection method for connectors, further improves the tightness of the connection while maintaining good strength and compressive strength.

[0011] Based on the first inventive objective, the technical solution of this application includes a tubular fastener and an induction heating structure. The fastener includes, from the outside to the inside, a first polyethylene layer, a first metal layer, and a second polyethylene layer. When connected, the two ends of the fastener are respectively fitted into the connecting ends of the two basalt polyethylene composite pipes, and the induction heating structure is located outside the two basalt polyethylene composite pipes.

[0012] Among them, the induction heating structure is an existing structure. Its basic working principle is to use alternating current to generate alternating magnetic field. The alternating magnetic field causes eddy currents inside the metal conductor, thereby causing the metal workpiece to heat up rapidly.

[0013] During the induction heating process, the first metal layer heats up, causing the first polyethylene layer to melt. The melted polyethylene layer expands and fills the gap between the composite tube and the fixing component until the polyethylene layers on the inner and outer surfaces of the composite tube also produce melt. The two melts fuse together and, after cooling and forming, the composite tube and the fixing component are tightly connected as one.

[0014] The heating direction of the induction heating structure is from the inside to the outside. Therefore, the first metal layer heats up first, followed by the basalt fiber layer of the composite tube. This ensures the fusion between the composite tube and the fastener, improving the connection efficiency.

[0015] Compared with existing connectors, the fasteners in this structure are located on the inner wall of the composite pipe. Due to the presence of a first metal layer, the thickness of the fasteners after melting is thinner, which reduces the resistance caused by the thickness of the fasteners at the connection point of the composite pipe and improves the compressive strength of the fasteners and the composite pipe at the connection point.

[0016] Existing structures typically have a thicker connection, which cannot keep the inner wall of the pipe smooth, thus affecting the flow area. If the existing structure has a thinner connection, it cannot be used in high-pressure composite pipes.

[0017] Therefore, under the action of the first metal layer, this structure can not only maintain the flow area without affecting the thickness, but also have good strength and pressure resistance at the connection, and is suitable for both high-pressure and low-pressure composite pipes.

[0018] Based on this, a heat insulation layer is provided between the first metal layer and the second polyethylene layer of the fastener. The heat insulation layer ensures that when the first metal layer is heated, it can only melt the first polyethylene layer and the polyethylene inside the composite pipe, ensuring that the inner wall of the basalt polyethylene composite pipe will not deform, further improving its compressive strength and ensuring that the inner wall of the pipe is smooth and does not affect the flow efficiency.

[0019] Furthermore, the fastener has an interface connector on its side, which includes a second metal layer and a third polyethylene layer fitted onto the second metal layer. When the two composite tubes are fitted onto both ends of the fastener, the interface connector is located between the openings of the two composite tubes. During heating, the second metal layer of the interface connector heats up, causing the third polyethylene layer and the polyethylene layer at the opening of the composite tube to melt and eventually fuse together. After cooling and molding, the opening of the composite tube is completely enclosed from the inside out, thereby improving the strength of the composite tube interface.

[0020] Existing connectors cannot effectively seal the pipe openings of composite pipes, resulting in the pipe openings being a location with poor strength and pressure resistance during use, making them prone to accidents. This structure effectively solves the above problems through interface connectors with a second metal layer.

[0021] Furthermore, preferably, the width of the second metal layer is less than or equal to the outer diameter of the two basalt-polyethylene composite pipes. The second metal layer, located within the two composite pipes, not only improves the strength and pressure resistance at the pipe openings but also does not affect normal use. Simultaneously, the width of the third polyethylene layer is greater than the outer diameter of the two basalt-polyethylene composite pipes. When the third polyethylene layer melts, it can fuse with the polyethylene layers of the composite pipes, completely encapsulating and connecting the pipe openings.

[0022] Furthermore, this structure also includes fixing rings for securing the outer surfaces of the two basalt-polyethylene composite pipes. Each fixing ring has an adjusting element for adjusting its inner diameter, and several metal connecting teeth are located on its inner side. The metal connecting teeth of the fixing ring generate heat, which melts the outer polyethylene layer of the composite pipe. Once the fixing element and the inner wall of the composite pipe are thermally fused together, the adjusting element is used to tighten the fixing ring, causing the metal connecting teeth to engage with the basalt fibers. This improves the safety and reliability of the pipeline and completely solves the safety hazards associated with traditional joint methods.

[0023] For another purpose of the invention, a method for connecting basalt-polyethylene composite pipes includes the following steps:

[0024] The two ends of the fastener are respectively fitted into the connecting ends of the two basalt polyethylene composite pipes;

[0025] After installing the fasteners and the basalt-polyethylene composite pipe, install several fixing rings on the outer wall of the connecting end of the basalt-polyethylene composite pipe.

[0026] The induction coil of the induction heating structure is wound around the outer wall of two basalt polyethylene composite pipes and several fixing rings. The first metal layer is heated, so that the first polyethylene layer of the fixing component melts with the inner polyethylene layer of the connection end of the basalt polyethylene composite pipe. The adjusting component is adjusted so that the metal connecting teeth are inserted into the basalt fiber layer of the basalt polyethylene composite pipe.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] This invention relates to a connector and connection method for basalt-polyethylene composite pipes. An induction coil causes the first metal layer of the fixing component to heat up, melting the first polyethylene layer and generating a melt. This melt expands and fills the gaps in the composite pipes until melt is also generated on the inner and outer surfaces of the composite pipes. The two melts fuse together, and after cooling and solidification, the fixing component is tightly connected to the two composite pipes as one unit. This structure not only allows for rapid connection and convenient construction, but also offers superior strength, density, and compressive strength compared to other connection structures and methods. Furthermore, it maintains a smooth inner wall of the pipe, without affecting the flow area.

[0029] Secondly, the pre-embedded first metal layer in the fastener reduces the thickness of the inner wall of the fastener, thereby reducing the resistance of the composite pipe to the thickness of the fastener and improving the compressive strength of the fastener.

[0030] Furthermore, a heat insulation layer is provided between the first metal layer and the second polyethylene layer, so that the heating temperature of the first metal layer can only melt the first polyethylene layer on the outside of the fastener and the polyethylene material on the inner wall of the composite pipe, ensuring that the inner wall of the basalt polyethylene composite pipe will not deform.

[0031] Meanwhile, the induction heat fusion method allows the metal connecting teeth to grip into the basalt fiber layer, improving the safety and reliability of the composite pipe and solving the safety hazards of traditional joint methods. Attached Figure Description

[0032] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0033] Figure 1 This is a schematic diagram of the fastener structure in Example 1;

[0034] Figure 2 This is a schematic diagram of the fixing structure with interface connectors in Embodiment 3;

[0035] Figure 3 This is a schematic diagram of the structure between the interface connector and the composite pipe in Example 3;

[0036] Figure 4 This is a schematic diagram of one structure of the fixing ring in Example 4;

[0037] Figure 5 This is a schematic diagram of another structure of the fixing ring in Example 4;

[0038] Figure 6 This is a schematic diagram of the structure after the first composite pipe, the second composite pipe and the fastener are connected in Example 5.

[0039] The attached diagram shows the markings and corresponding component names:

[0040] 1-Fixing component, 2-First polyethylene layer, 3-First metal layer, 4-Second polyethylene layer, 5-Insulation layer, 6-Second metal layer, 7-Third polyethylene layer, 8-First composite pipe, 81-First outer polyethylene layer, 82-First basalt fiber layer, 83-First inner polyethylene layer, 9-Second composite pipe, 91-Second outer polyethylene layer, 92-Second basalt fiber layer, 93-Second inner polyethylene layer, 10-Fixing ring, 11-Metal connecting teeth, 12-Induction coil. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0042] In the description of this invention, it should be understood that the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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 limiting the scope of protection of this invention.

[0043] Example 1

[0044] The connector includes a fixing member 1, which is a tubular structure, and an induction heating structure, wherein the fixing member 1 is as follows: Figure 1 As shown, from the outside to the inside, it includes a first polyethylene layer 2, a first metal layer 3, and a second polyethylene layer 4.

[0045] The two ends of the fastener 1 are respectively fitted into the connecting ends of the two basalt polyethylene composite pipes, and the outer diameter of the fastener 1 is greater than or equal to the inner diameter of the connecting ends of the two basalt polyethylene composite pipes. The effect is best when the outer diameter of the fastener 1 is equal to the inner diameter of the connecting ends of the two basalt polyethylene composite pipes. Because the polyethylene layer is elastic, the connection can be more securely fastened when the outer diameter of the fastener 1 is greater than the inner diameter of the connecting ends of the two basalt polyethylene composite pipes.

[0046] The induction heating structure includes an induction coil 12 and an induction heating controller. In use, the two ends of the fixing part 1 are respectively fitted into the connecting ends of the two basalt polyethylene composite pipes. Then, the induction coil 12 is wound around the two basalt polyethylene composite pipes at the point where it overlaps with the fixing part. The induction heating controller heats the first metal layer 3 to a temperature that can melt the polyethylene material.

[0047] When the first metal layer 3 is heated, the first polyethylene layer 2 melts, expands and fills the gap between the composite pipe and the fastener until the polyethylene layer on the inner surface of the composite pipe also produces melt. The two melts fuse together and, after cooling and molding, the composite pipe and the fastener are tightly connected as one.

[0048] Example 2

[0049] Based on Example 1, a heat insulation layer 5 is provided between the first metal layer 3 and the second polyethylene layer 4 of the fastener 1. When the first metal layer 3 heats up, the first polyethylene layer 2 melts while the second polyethylene layer 4 does not melt, ensuring that the inner wall of the composite pipe will not deform, thereby maintaining the smoothness of the inner wall of the pipe.

[0050] Example 3

[0051] like Figure 2 As shown, the side of the fastener 1 is provided with an interface connector, which includes a second metal layer 6 and a third polyethylene layer 7 fitted on the second metal layer 6.

[0052] In some embodiments, the fastener 1 is annular.

[0053] In some embodiments, the second metal layer 6 is connected to the first metal layer 3, and the third polyethylene layer 7 is connected to the first polyethylene layer 2.

[0054] When the induction heating structure heats up, the second metal layer 6 and the first metal layer 3 heat up, causing the third polyethylene layer 7 and the first polyethylene layer 2 to melt. The inner and outer polyethylene layers of the composite pipe also melt, and finally the composite pipe, the fixing component, and the pipe opening and interface connector between the two composite pipes are all connected as one.

[0055] In some embodiments, such as Figure 3 As shown, the width of the second metal layer 6 is less than or equal to the outer diameter of the two basalt polyethylene composite pipes. Preferably, the width of the second metal layer 6 is equal to the outer diameter of the two basalt polyethylene composite pipes. The width of the second metal layer 6 refers to the length in the direction perpendicular to the axis of the fixing member, that is, the second metal layer 6 is located inside the basalt polyethylene composite pipe.

[0056] In some embodiments, such as Figure 3 As shown, the width of the third polyethylene layer 7 is greater than the outer diameter of the two basalt polyethylene composite pipes. The width of the third polyethylene layer 7 refers to its length in the direction perpendicular to the axis of the fastener, that is, the third polyethylene layer 7 is located outside the two basalt polyethylene composite pipes.

[0057] Example 4

[0058] Based on the above embodiments, the connector also includes a fixing ring 10 for fixing to the outer side of the two basalt polyethylene composite pipes. The fixing ring 10 is provided with an adjusting member for adjusting the inner diameter of the fixing ring 10, and a plurality of metal connecting teeth 11 are provided on the inner side of the fixing ring 10.

[0059] In some embodiments, such as Figure 4 As shown, the fixing ring 10 is a retaining ring with two connecting ends. The adjusting component consists of several connecting holes and bolts respectively set on the two connecting ends. The inner diameter of the fixing ring is adjusted by connecting the adjusting bolts into different connecting holes. In use, after the fixing component is connected to the two composite pipes, the fixing ring is fixed at the position on the outside of the two composite pipes that coincides with the fixing component. The metal connecting teeth 11 are in contact with the polyethylene layer on the outside of the composite pipe. Then, the induction coil 12 is wound around the outer wall of the two basalt polyethylene composite pipes and the several fixing rings 10. After heating, the first metal component heats up and the metal connecting teeth 11 heats up. After the fixing component is connected to the composite pipe, the fixing ring is adjusted so that the metal connecting teeth 11 are inserted into the basalt fiber of the composite pipe.

[0060] In some embodiments, the fixing ring 10 is as follows: Figure 5 As shown, a metal sheet stamping method is used. The metal sheet is cut to the required length and outer diameter of the basalt-polyethylene composite pipe. The cut metal sheet is then placed into a stamping die for serpentine punching to obtain metal connecting teeth 11. The two ends of the metal sheet are then rolled and welded to obtain a retaining ring.

[0061] Example 5

[0062] Based on the above embodiments, the connection method for basalt-polyethylene composite pipes includes the following steps:

[0063] like Figure 6 As shown, the two basalt-polyethylene composite pipes are a first composite pipe 8 and a second composite pipe 9. The first composite pipe 8 includes a first outer polyethylene layer 81, a first basalt fiber layer 82, and a first inner polyethylene layer 83 from the outside to the inside. The second composite pipe 9 includes a second outer polyethylene layer 91, a second basalt fiber layer 92, and a second inner polyethylene layer 93 from the outside to the inside.

[0064] The two ends of the fastener 1 are respectively fitted into the connecting ends of the first composite pipe 8 and the second composite pipe 9. The first polyethylene layer 2 of the fastener 1 is in contact with the first inner polyethylene layer 83 and the second inner polyethylene layer 93. The third polyethylene layer 7 is in contact with the first outer polyethylene layer 81, the first basalt fiber layer 82 and the first inner polyethylene layer 83 at the pipe opening of the first composite pipe 8. The third polyethylene layer 7 is in contact with the second outer polyethylene layer 91, the second basalt fiber layer 92 and the second inner polyethylene layer 93 at the pipe opening of the second composite pipe 9.

[0065] Several fixing rings 10 are fitted on the outer walls of the first composite tube 8 and the second composite tube 9, and the metal connecting teeth 11 are in contact with the first outer polyethylene layer 81 and the second outer polyethylene layer 91.

[0066] The induction coil 12 of the induction heating structure is wound around the first composite tube 8, the second composite tube 9, and the fixing ring 10. The first metal layer 3, the first basalt fiber layer 82, the second basalt fiber layer 92, and the second metal layer 6 are heated to a temperature that can melt the polyethylene material by the induction heating controller.

[0067] The first metal layer 3 heats up first. After the first polyethylene layer 2 of the fastener is fused together with the first inner polyethylene layer 83 and the second inner polyethylene layer 93, the inner diameter of the fixing ring 10 is adjusted so that the metal connecting teeth 11 are inserted into the first basalt fiber layer 82 and the second basalt fiber layer 92.

[0068] Apply a protective layer of polyurea coating to the outside, and the connection construction is complete.

[0069] The terms "first," "second," and "third" used in this document are merely for clarity of description and are not intended to restrict any order or emphasize importance. Furthermore, the term "connection" used in this document, unless otherwise specified, can refer to a direct connection or an indirect connection via other components.

[0070] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A connector based on a basalt-polyethylene composite pipe, characterized in that, The device includes a tubular fastener (1) and an induction heating structure. The fastener (1) consists of a first polyethylene layer (2), a first metal layer (3), and a second polyethylene layer (4) from the outside to the inside. The two ends of the fastener (1) are respectively used to fit into the connecting ends of two basalt polyethylene composite pipes. The outer diameter of the fastener (1) is greater than or equal to the inner diameter of the connecting ends of the two basalt polyethylene composite pipes. The induction heating structure is located outside the two basalt polyethylene composite pipes and is used to heat the first metal layer (3) so that the first polyethylene layer (2) melts, expands and fills the gap between the basalt polyethylene composite pipe and the fastener (1) until the polyethylene layer on the inner surface of the basalt polyethylene composite pipe also produces a melt, and the two melts fuse together. A heat insulation layer (5) is provided between the first metal layer (3) and the second polyethylene layer (4) of the fastener (1). An interface connector is provided on the side of the fastener (1). The interface connector includes a second metal layer (6) and a third polyethylene layer (7) fitted on the second metal layer (6).

2. The connector based on basalt-polyethylene composite pipe according to claim 1, characterized in that, The fastener (1) is ring-shaped.

3. The connector based on basalt-polyethylene composite pipe according to claim 1, characterized in that, The width of the second metal layer (6) is less than or equal to the outer diameter of the two basalt polyethylene composite pipes.

4. The connector based on basalt-polyethylene composite pipe according to claim 1, characterized in that, The width of the third polyethylene layer (7) is greater than the outer diameter of the two basalt polyethylene composite pipes.

5. The connector based on basalt-polyethylene composite pipe according to claim 1, characterized in that, It also includes a fixing ring (10) for fixing to the outer side of two basalt polyethylene composite pipes. The fixing ring (10) is provided with an adjusting member for adjusting the inner diameter of the fixing ring (10). The inner side of the fixing ring (10) is provided with several metal connecting teeth (11).

6. A connection method based on basalt-polyethylene composite pipes, characterized in that, The connector comprising any one of claims 1-5 includes the following steps: The two ends of the fastener (1) are respectively fitted into the connecting ends of the two basalt polyethylene composite pipes; The induction coil (12) of the induction heating structure is wound around the outer wall of the two basalt polyethylene composite pipes to heat the first metal layer (3), so that the first polyethylene layer (2) of the fixing member (1) melts with the inner polyethylene layer of the connection end of the basalt polyethylene composite pipe.

7. The connection method based on basalt-polyethylene composite pipe according to claim 6, characterized in that, Also includes: After installing the fastener (1) and the basalt polyethylene composite pipe, install several fixing rings (10) on the outer wall of the connecting end of the basalt polyethylene composite pipe. The induction coil (12) of the induction heating structure is wound around the fixed ring (10) to heat the first metal layer (3).

8. The connection method based on basalt-polyethylene composite pipe according to claim 7, characterized in that, The induction coil (12) of the induction heating structure is wound around the fixed ring (10), so that the metal connecting teeth (11) come into contact with the outer wall of the basalt polyethylene composite pipe. After heating, the adjusting component is adjusted so that the metal connecting teeth (11) are inserted into the basalt fiber layer of the basalt polyethylene composite pipe.

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