Nonmetal pipeline with thermal insulation performance and manufacturing method thereof

Abstract

The invention discloses a non-metal pipeline with heat preservation performance and a manufacturing method thereof. The non-metal pipeline comprises a non-metal pipe body, a heat preservation layer and a polyethylene outer protection pipe, wherein the non-metal pipe body is sequentially and coaxially sleeved with the heat preservation layer and the polyethylene outer protection pipe. The non-metal pipe body is further sleeved with a plurality of supports, and the other free ends of the supports abut against the polyethylene outer protection pipe. The thermal insulation layer is prepared by foaming and curing a thermal insulation material; the thermal insulation material comprises a component A and a component B, the component A comprises the following components in percentage by mass: 1%-5% of ethylenediamine polyether, 0.5%-2.5% of triethanolamine trifluorotrichloroethane silicone oil, 5%-10% of B-trichloroethyl phosphate and the balance of I type fire-retardant polyether; the component B is prepared from polyphenyl polyisocyanate; the mass ratio of the component A to the component B is 1: (1-1.05). The non-metal pipeline has a good heat preservation effect.

Description

Technical Field

[0001] This invention belongs to the field of non-metallic pipe insulation engineering technology, and relates to a non-metallic pipe with insulation properties and its manufacturing method. Background Technology

[0002] Non-metallic pipelines, thanks to continuous advancements in manufacturing and installation technologies, have demonstrated broad application potential across various fields. Particularly in energy and chemical industries, municipal construction, and our daily lives, non-metallic pipelines are gradually replacing some metal pipelines due to their unique advantages. However, when non-metallic pipelines are applied in specific scenarios such as oilfield gathering and transportation, insulation becomes crucial for improving their transport efficiency.

[0003] Currently, insulation methods for non-metallic pipelines mainly draw on the insulation technologies used for metallic pipelines. These include on-site wrapping with composite silicates, rock wool, microporous calcium silicate, etc., and on-site foaming with polyurethane foam. While these methods meet the insulation needs of non-metallic pipelines to some extent, they also reveal some problems. Because the single-piece length of non-metallic pipelines is usually much longer than that of metallic pipelines, and they are often transported in coils, traditional metal shell insulation or on-site foaming methods face challenges in practical applications. In particular, while on-site bundling of the insulated shell has lower raw material costs, it incurs high on-site labor costs, and the insulation effect is difficult to sustain. Due to the significant difference in elastic load-bearing capacity between the insulated shell and the non-metallic pipeline body, the insulation layer often cracks and fails after a period of operation, thus affecting the pipeline's insulation performance and service life.

[0004] To address these issues, the industry has begun exploring new insulation methods. Among them, the "hollow" type PE anti-corrosion insulation pipe is an innovative solution. This pipe's end face is designed with multiple hollow sections symmetrically distributed relative to a central hollow section. This design not only enhances the pipe's rigidity but also provides internal and external corrosion protection and insulation. More importantly, the "hollow" type PE anti-corrosion insulation pipe is formed in one piece with the pipe body, simplifying the manufacturing process and reducing costs. However, this type of pipe also has certain limitations, currently primarily suitable for pipeline transportation projects in medium- and low-pressure areas and non-high-altitude cold regions. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a non-metallic pipe with thermal insulation properties and its manufacturing method, thereby solving the technical problem of poor thermal insulation effect of non-metallic pipes in the prior art.

[0006] This invention is achieved through the following technical solution: A non-metallic pipe with thermal insulation properties includes a non-metallic pipe body, and a thermal insulation layer and a polyethylene outer protective pipe that are coaxially sleeved on the outside of the non-metallic pipe body in sequence; a plurality of supports are also sleeved on the outside of the non-metallic pipe body, and the other free end of the plurality of supports abuts against the polyethylene outer protective pipe. The insulation layer is obtained by foaming and curing the insulation material. The thermal insulation material comprises component A and component B; By weight percentage, component A comprises 1% to 5% ethylenediamine polyether, 0.5% to 2.5% triethanolamine trifluorotrichloroethane silicone oil, and 5% to 10% β-trichloroethyl phosphate, with the balance being type I flame-retardant polyether; Component B includes polyphenyl polyisocyanate; When used, the mass ratio of component A to component B is 1:(1~1.05).

[0007] Preferably, the bracket includes a support ring and a plurality of support members spaced apart circumferentially along the support ring.

[0008] Preferably, the inner diameter of the support ring is the same as the outer diameter of the non-metallic pipe body; the height of the support member along the radial direction of the support ring is the same as the thickness of the insulation layer.

[0009] Preferably, 4 to 10 support members are evenly spaced along the circumference of the support ring.

[0010] Preferably, a support is provided at intervals of 0.5 to 2 m on the outside of the non-metallic tube body.

[0011] The above-mentioned method for manufacturing a non-metallic pipe with thermal insulation properties includes the following steps: S1: Several supports are sleeved along the axial direction of the non-metallic pipe body, and then the non-metallic pipe body with the supports is inserted into the polyethylene outer protective pipe, so that the free ends of the several supports abut against the polyethylene outer protective pipe, thereby fixing the non-metallic pipe body and the polyethylene outer protective pipe. The outer wall of the non-metallic pipe body and the inner wall of the polyethylene outer protective pipe form a heat insulation cavity. S2: The insulation material is injected into the insulation layer cavity, foamed, and then cured to obtain the non-metallic pipe with insulation properties.

[0012] Preferably, during the foaming process, the foaming temperature is 18~30℃, the insulation time is 38~40 s, and the fiber time is 206~210 s.

[0013] Preferably, during the curing process, the free throw density is monitored to be 33~35 kg / m³. 3 .

[0014] Preferably, during the ripening process, the ripening time at room temperature is 2-4 hours.

[0015] Preferably, in step S1, before installing several supports along the axial direction of the non-metallic tube body, the surface of the non-metallic tube body is cleaned, and the cleaning process specifically involves washing the surface of the non-metallic tube body with water.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: This invention discloses a non-metallic pipe with thermal insulation properties. The insulation layer in this pipe is obtained by foaming and curing the insulation material of this invention, which has high-efficiency thermal insulation performance, effectively reducing heat transfer and thus reducing energy loss. During the foaming and curing process, the insulation material can form a uniform foam structure, avoiding the generation of thermal bridging effect and improving insulation efficiency. The insulation material of this invention includes component A and component B in a mass ratio of 1:(1~1.05). By mass percentage, component A includes 1%~5% ethylenediamine polyether, 0.5%~2.5% triethanolamine trifluorotrichloroethane silicone oil, and 5%~10%... B-trichloroethyl phosphate, with the balance being type I flame-retardant polyether; component B includes polyphenyl polyisocyanate, with type I flame-retardant polyether as the main base material, providing excellent thermal insulation performance, which is a core requirement for thermal insulation materials; ethylenediamine polyether, as a chain extender and crosslinking agent, can enhance the strength and toughness of polyurethane foam. The improvement in strength and toughness helps maintain the integrity of the insulation layer and reduces the decline in thermal insulation performance caused by external forces; the presence of triethanolamine trifluorotrichloroethane silicone oil can improve the lubricity and fluidity of the material, making the foam more uniform during formation. The uniform foam structure helps reduce the thermal bridging effect and improve the thermal insulation efficiency; B-trichloroethyl phosphate, as a flame retardant, can further improve the flame retardant performance of the material. At the same time, it can also improve the weather resistance and cold resistance of the material, enabling the thermal insulation material to maintain stable thermal insulation performance under extreme climatic conditions; polyphenyl polyisocyanate is one of the main reactants of polyurethane foam, reacting with the polyether in component A to form a stable polyurethane structure. This structure has excellent thermal insulation performance and sound insulation effect, and can effectively reduce heat transfer. The synergistic effect of components A and B in this invention gives the material excellent thermal insulation performance, effectively reducing energy loss. The material maintains stable insulation performance even under extreme climatic conditions, demonstrating strong adaptability. This invention employs a one-step method for foaming and insulating non-metallic pipes with polyurethane foam. By adjusting the formulation ratio between polymeric ethers and polyphenyl polyisocyanates in the insulation raw materials, the thermal conductivity of the insulation material is reduced, the temperature during the foaming process is controlled, and the insulation efficiency of non-metallic pipes is improved.

[0017] In addition, several supports are installed on the outside of the non-metallic pipe to ensure the coaxiality of the non-metallic pipe body, the insulation layer, and the polyethylene outer protective pipe. The supports ensure a tight fit and uniform support between the non-metallic pipe body, the insulation layer, and the polyethylene outer protective pipe, preventing a decrease in insulation performance due to pipe deformation. The support's abutment effect makes the entire pipe structure more stable, able to withstand certain external pressures and impacts, ensuring normal operation of the pipeline in complex environments. The polyethylene outer protective pipe has good wear resistance and corrosion resistance, effectively protecting the insulation layer from external environmental erosion and extending the pipeline's service life. The polyethylene material... The material exhibits good resistance to ultraviolet radiation, preventing material aging and embrittlement caused by UV exposure, thus maintaining stable insulation performance. The polyethylene outer protective pipe is tightly bonded to the insulation layer, forming a good sealing structure that effectively prevents the penetration of external factors such as moisture and air, further improving the insulation effect. The insulation layer on the outside of the non-metallic pipe body and the polyethylene outer protective pipe together constitute a multi-layer protective structure, which can effectively reduce heat loss and improve the insulation performance of the pipeline. This pipeline structure is suitable for various occasions requiring high-efficiency insulation, such as heating, cooling, and oil transportation pipeline projects, and can meet the insulation needs of different environments.

[0018] Furthermore, the support includes a support ring and a plurality of support members spaced circumferentially along the support ring; the inner diameter of the support ring is the same as the outer diameter of the non-metallic pipe body; the height of the support members along the radial direction of the support ring is the same as the thickness of the insulation layer. Firstly, the inner diameter of the support ring being the same as the outer diameter of the non-metallic pipe body ensures that the support can fit tightly against the non-metallic pipe body, avoiding heat loss due to gaps. The support members being spaced circumferentially along the support ring and having a height consistent with the thickness of the insulation layer provides uniform support force, allowing the insulation layer to withstand heat... The support structure is designed to prevent deformation under external forces, thus maintaining its thermal insulation performance. Secondly, the support components prevent the insulation layer from forming a continuous heat conduction path in the radial direction, reducing thermal bridging and further improving insulation efficiency. The synergistic effect of the support rings and components enhances the stability of the entire pipe structure, making the pipe less prone to deformation or damage under external forces, thereby ensuring the integrity and effectiveness of the insulation layer. The support structure is simple to design; installation simply requires fitting the support rings onto the non-metallic pipe body and ensuring a tight fit between the support components and the insulation layer, eliminating the need for complex procedures.

[0019] Furthermore, a support is installed at intervals of 0.5 to 2 meters on the exterior of the non-metallic pipe body. By installing a support at regular intervals on the exterior of the non-metallic pipe body, the pipe can be divided into multiple independent support sections. This segmented support method can effectively distribute the external load on the pipe and prevent the pipe from sagging or deforming due to long-distance lack of support. The installation of supports increases the rigidity of the pipe, enabling it to better maintain its shape and stability when subjected to external forces. This increased rigidity helps reduce pipe vibration and noise, and improves the service life of the pipe.

[0020] This invention also discloses a method for manufacturing a non-metallic pipe with thermal insulation properties. First, several supports are fitted along the axial direction of the non-metallic pipe body. Then, the non-metallic pipe body with the supports is inserted into a polyethylene outer protective pipe, so that the free ends of the supports abut against the polyethylene outer protective pipe, thereby fixing the non-metallic pipe body and the polyethylene outer protective pipe. A thermal insulation cavity is formed between the outer wall of the non-metallic pipe body and the inner wall of the polyethylene outer protective pipe. Then, the above-mentioned thermal insulation material is injected into the thermal insulation cavity, foamed, and then cured to obtain the non-metallic pipe with thermal insulation properties. This method forms a thermal insulation layer on the outer layer of the non-metallic pipe in one step, which is simple and efficient, has a stable and reliable structure, excellent thermal insulation performance, and is easy to control.

[0021] Furthermore, during the foaming process, the foaming temperature is 18~30℃, the insulation time is 38~40 s, and the fiber time is 206~210 s. Firstly, the foaming temperature range of 18~30℃ is conducive to the rapid reaction of the foaming agent and the formation of stable foam. This temperature range is neither too high, which would cause the foam to break or react too violently, nor too low, which would cause the foaming agent to react slowly or the foam to be unstable. The precise control of the insulation time and fiber time ensures that the foaming agent and the material are fully mixed and react to form a stable and uniform foam structure. The length of the insulation time directly affects the degree of dispersion and reaction of the foaming agent in the material, while the fiber time determines the stability of the foam and its morphology before curing. By optimizing the foaming temperature and time parameters, a foam layer with moderate density and uniform pore distribution can be obtained. This foam layer has better thermal insulation performance, can effectively reduce heat transfer, and improve the insulation efficiency of the pipeline. The stable foam structure can form a tight sealing layer to prevent the penetration of external factors such as moisture and air, further improving the insulation performance and durability of the pipeline.

[0022] Furthermore, during the curing process, the free throw density was monitored to be 33~35 kg / m³. 3Free-throw density is one of the important indicators for evaluating the thermal insulation performance of foam materials. Controlling the free-throw density within the range of 33~35 kg / m³ ensures that the foam material has a suitable pore structure and density distribution, thus providing excellent thermal insulation performance. Suitable density helps reduce the material's thermal conductivity, decrease heat transfer, and improve the insulation efficiency of pipelines. During the curing process, controlling the free-throw density allows the foam material to maintain a certain degree of flexibility while possessing a certain strength. This strength helps improve the overall structural stability of the pipeline and prevents deformation or damage caused by external forces. Suitable density also improves the durability of the foam material, enabling it to maintain good thermal insulation performance and structural stability during long-term use.

[0023] Furthermore, during the curing process, the curing time at room temperature is 2-4 hours. This curing time ensures that the polyurethane adhesive fully reacts within the pipe insulation layer. This thorough reaction helps form a stable chemical structure, improving the overall performance of the insulation layer. During curing, the polyurethane adhesive gradually hardens, enhancing the adhesion between the adhesive and the pipe body and the polyethylene outer sheath. This enhanced adhesion helps improve the overall structural stability and durability of the pipe. A fully cured insulation layer exhibits better thermal insulation performance, effectively reducing heat transfer and improving the pipe's insulation efficiency.

[0024] Furthermore, in step S1, before installing several supports along the axial direction of the non-metallic pipe body, the surface of the non-metallic pipe body is cleaned. Specifically, the cleaning process involves cleaning the surface of the non-metallic pipe body with ethanol and water. A clean surface can reduce the possibility of air bubbles being generated when the insulation material fills the insulation layer cavity, improve the uniformity and density of the insulation layer, and a clean, uncontaminated interface helps to ensure a tight bond between the insulation material and the pipe body, reducing the channels for heat transfer and thus improving the insulation performance. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a cross-sectional view of a non-metallic pipe with thermal insulation properties according to the present invention. Figure 2 This is a schematic diagram of the structure of a non-metallic pipe support with thermal insulation properties according to the present invention; Figure 3This is a schematic diagram illustrating the fixing of a non-metallic pipe with thermal insulation properties during the filling of thermal insulation material, as described in this invention. Figure 4 This is a schematic flowchart of a method for preparing a non-metallic pipe with thermal insulation properties according to the present invention.

[0027] The components are: 1. Non-metallic pipe body, 2. Insulation layer, 3. Polyethylene outer protective pipe, 4. Bracket, 41. Support ring, 42. Support component, 5. Support block, 6. Fixing component. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0030] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0031] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present 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, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0032] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0033] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0034] The present invention will now be described in further detail with reference to the accompanying drawings: Example 1 This invention discloses a thermal insulation material comprising component A and component B; by mass percentage, component A comprises type I flame-retardant polyether, 1%~5% ethylenediamine polyether, 0.5%~2.5% triethanolamine trifluorotrichloroethane silicone oil, and β-trichloroethyl phosphate; component B comprises polyphenyl polyisocyanate. When used, the mass ratio of component A to component B is 1:1.

[0035] The raw materials mentioned above should meet the following indicators, as detailed in Table 1: Table 1 Technical requirements for the thermal insulation material in this invention

[0036] Example 2 like Figure 1 As shown, the present invention also discloses a non-metallic pipe with thermal insulation properties, including a non-metallic pipe body 1, and a thermal insulation layer 2 and a polyethylene outer protective pipe 3 sequentially and coaxially sleeved on the outside of the non-metallic pipe body 1; the thermal insulation layer 2 is obtained by foaming and curing the thermal insulation material as described in claim 1; a plurality of supports 4 are also sleeved on the outside of the non-metallic pipe body 1, and the other free end of the plurality of supports 4 abuts against the polyethylene outer protective pipe 3.

[0037] like Figure 2 As shown, the bracket 4 includes a support ring 41 and a plurality of support members 42 spaced apart circumferentially along the support ring 41; the inner diameter of the support ring 41 is the same as the outer diameter of the non-metallic tube body 1; the height of the support member 42 along the radial direction of the support ring 41 is the same as the thickness of the insulation layer 2.

[0038] In a preferred embodiment, 4 to 10 support members 42 are evenly spaced along the circumference of the support ring 41. Simultaneously, a bracket 4 is provided at intervals of 0.5 to 2 meters on the exterior of the non-metallic tube body 1.

[0039] Example 3 The above-mentioned method for manufacturing a non-metallic pipe with thermal insulation properties includes the following steps: S1: Several supports 4 are sleeved along the axial direction of the non-metallic tube body 1, and then the non-metallic tube body 1 with the supports 4 is inserted into the polyethylene outer protective tube 3, so that the free ends of the several supports 4 abut against the polyethylene outer protective tube 3, thereby completing the fixation of the non-metallic tube body 1 and the polyethylene outer protective tube 3. The outer wall of the non-metallic tube body 1 and the inner wall of the polyethylene outer protective tube 3 form a heat insulation cavity. S2: The thermal insulation material described in claim 1 is injected into the thermal insulation layer cavity, foamed, and then cured to obtain the non-metallic pipe with thermal insulation properties.

[0040] In the preferred embodiment, during the foaming process, the foaming temperature is 18~30℃, the soaking time is 38~40 s, and the fiber time is 206~210 s. During the curing process, the free-throw density is monitored to be 33~35 kg / m³. 3 During the ripening process, the ripening time is 2-4 hours at room temperature.

[0041] In addition, in step S1, before installing several supports 4 along the axial direction of the non-metallic tube body 1, the surface of the non-metallic tube body 1 is cleaned. The cleaning process specifically involves cleaning the surface of the non-metallic tube body 1 with ethanol and water.

[0042] Example 4 To further explain the manufacturing process of the insulated pipe in this invention, the following embodiments are provided. Specifically, a high-efficiency, energy-saving foamed insulation construction method for pipelines is disclosed. This method is implemented at an ambient temperature of 0~30℃ and is applicable to pipe diameters ranging from DN15 to DN600. The main process flow is as follows: 1. Pipe surface pretreatment: First, clean the pipe surface to remove oil and other impurities to improve the adhesion between the insulation material and the pipe; 2. Install the insulation outer sheath support: Install the steel support for the rigid HDPE polyethylene outer sheath, which also serves as the insulation layer, i.e., the support 4 in this invention, within the annular space between the non-metallic pipe body 1 and the polyethylene outer sheath 3. This ensures that the polyethylene outer sheath 3 is stably installed outside the non-metallic pipe body 1, ensuring the stability of the pipeline and preventing excessive eccentricity during insulation foaming. The structure of the support 4 is shown below. Figure 2 The length of the support legs, i.e., the height of the support member 42, is consistent with the thickness of the designed insulation layer 2. The number of support legs is determined by the pipe diameter; the larger the pipe diameter, the larger the support legs, ensuring the stability of the outer protective pipe installation. The support is fixed to the outside of the non-metallic pipe in a segmented installation manner, with one support every 1m.

[0043] 3. Install the polyethylene outer sheath: Select HDPE polyethylene outer sheath pipes of different diameters according to the designed insulation layer thickness. After determining the pipe installation position, use a pipe conveying machine to insert the non-metallic pipe body 1 into the polyethylene outer sheath pipe 3. Insert the bundled support core pipe into the HDPE outer sheath pipe on the V-groove until the exposed parts at both ends of the core pipe are 15cm or 20cm. The polyethylene outer sheath has a certain thickness and contains antioxidants, UV stabilizers, and carbon black, etc., and is black or yellow in color. Its functions are to protect the polyurethane insulation layer from mechanical damage and to provide corrosion and water resistance. Then, install a ring of support blocks 5 around the polyethylene outer sheath pipe and fix the support blocks 5 with fasteners 6 to ensure that the outer sheath frame is in the air. See the specific structure below. Figure 3 The fixing element 6 here can be iron wire, and the support block 5 can be a steel support block with a size of 10cm*5cm*5cm.

[0044] 4. Install the foaming machine: Seal the ends of the composite non-metallic pipe with the clamps (internal expansion or external clamps) that match the diameter of the pipe and the thickness of the insulation layer, and lock (tighten) them; After the pipe is installed and the ends are sealed, open the pouring hole in the middle of the HDPE outer protective pipe, and insert the pouring nozzle of the mixing head of the special high-pressure foaming machine into the pouring hole.

[0045] 5. Polyurethane Casting and Insulation Foaming: Rigid polyurethane foam is injected into the cavity between the steel pipe and the outer protective layer using a high-pressure foaming machine. The required amount of insulation material is calculated based on the insulation layer thickness and pipe diameter. The mixing ratio of the two materials in the high-pressure foaming machine is adjusted to 1:1. The equipment flow rate is measured, and the casting time (feed rate / flow rate) is set. The foaming agent is injected into the gap between the pipe and the outer protective shell for individual foaming. During the foaming process, the foaming temperature and time are carefully controlled to ensure uniform foaming without bubbles or voids. The material temperature is controlled within the range of 18~30℃. Real-time monitoring shows the foaming time is 38 seconds, the fiber time is 206 seconds, and the free-throw density is 33~35 kg / m³. 3 between.

[0046] The foaming time includes the incubation time and the fiber time. The incubation time refers to the time required for the foamed material to begin foaming and reach a stable state. During this time, the foaming agent should be fully activated and evenly distributed in the material. The fiber time refers to the time it takes for the foamed material to continue expanding and forming a stable structure. During this time, the foaming process should be ensured to proceed smoothly to avoid the formation of excessively large bubbles or voids.

[0047] Free-throw density is one of the important indicators for evaluating the quality of foamed materials. It can be controlled by adjusting parameters such as the amount of foaming agent, foaming temperature, and time. During the foaming process, the density change of the material should be monitored in real time and adjusted as needed.

[0048] After the process is completed, the performance of the insulation layer is tested. The main technical indicators of the rigid polyurethane foam are shown in Table 2: Table 2 Main Technical Indicators of Rigid Polyurethane Foam

[0049] 6. Seal the pouring holes: After all foaming work is completed, seal the last foaming opening to ensure the integrity and airtightness of the insulation layer; 7. Curing: After construction, wait for the insulation layer to cure, which takes approximately 3 hours. During curing, the insulation pipe must not be shaken, as this may cause the insulation layer to become eccentric or uneven. 8. Quality Inspection: During the foaming process, the thickness of the foam layer is measured in real time using a measuring instrument to ensure that the width of the joint of the insulation layer is not greater than 5mm; the allowable deviation for rigid insulation materials is +10mm; the polyurethane lining should be flat and smooth, with uniform color, firmly bonded to the substrate surface, without blistering, and the number of bubbles per square meter with a diameter not exceeding 5mm should be less than 3, and there should be no delamination, incomplete curing, or polyurethane leakage; After the above steps, the foam insulation construction is completed. A comprehensive inspection and testing of the pipeline is then conducted to ensure it meets quality standards before it can be put into use. The oxygen index of the insulation layer should be ≥27, and the density should be 40~70 kg / m³. 3 The water repellency rate is 98%, the thermal conductivity is 0.013~0.03kcal / mhoC, and the structure of the molded polyurethane insulation pipe is shown in Figure 5.

[0050] Example 5 To further explain the technical solution of the present invention, the following embodiments are provided: Non-metallic pipeline: A DN65 non-metallic water medium pipeline with a length of 3 km. After insulation treatment using the method described in this invention, its performance was tested, and the test results are shown in Table 3. Table 3. Test results of relevant performance of the insulation pipe in this embodiment.

[0051] This invention provides a highly efficient and energy-saving method for manufacturing non-metallic pipelines, improving the insulation efficiency of non-metallic pipelines. On-site polyurethane foam foaming typically employs a pipe-in-pipe or one-step molding process, requiring only on-site patching. The insulation layer thickness of crude oil pipelines is generally about 20-80mm, meeting the 30mm thickness requirement of oil fields. This process has low raw material costs and a long service life, but it requires high-level construction techniques and is prone to insulation layer misalignment during current construction. This invention, based on the original polyurethane foaming method, adjusts the polyurethane foam parameters, invents a support component, and simultaneously adjusts the control parameters during the foaming process, introducing a new non-metallic pipeline foaming method. This solves the problems of large workload and high labor costs associated with traditional pipe shell insulation for non-metallic pipelines, as well as the problem of insulation layer detachment and failure due to the large difference in load-bearing capacity between the traditional pipe shell insulation and the non-metallic pipeline body. It also solves the problem of high energy loss in non-metallic pipeline insulation.

[0052] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. 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 non-metallic pipe with thermal insulation properties, characterized in that, It includes a non-metallic pipe body (1), and a heat insulation layer (2) and a polyethylene outer protective pipe (3) that are coaxially sleeved on the outside of the non-metallic pipe body (1); the outside of the non-metallic pipe body (1) is also sleeved with a number of supports (4), and the other free end of the supports (4) abuts against the polyethylene outer protective pipe (3). The insulation layer (2) is obtained by foaming and curing the insulation material; The thermal insulation material comprises component A and component B; By weight percentage, component A comprises 1% to 5% ethylenediamine polyether, 0.5% to 2.5% triethanolamine trifluorotrichloroethane silicone oil, and 5% to 10% β-trichloroethyl phosphate, with the balance being type I flame-retardant polyether; Component B includes polyphenyl polyisocyanate; When used, the mass ratio of component A to component B is 1:(1~1.05).

2. A non-metallic pipe with thermal insulation properties according to claim 1, characterized in that, The bracket (4) includes a support ring (41) and a plurality of support members (42) arranged circumferentially along the support ring (41).

3. A non-metallic pipe with thermal insulation properties according to claim 2, characterized in that, The inner diameter of the support ring (41) is consistent with the outer diameter of the non-metallic tube body (1); the height of the support member (42) along the radial direction of the support ring (41) is consistent with the thickness of the insulation layer (2).

4. A non-metallic pipe with thermal insulation properties according to claim 2, characterized in that, Four to ten support members (42) are evenly spaced along the circumference of the support ring (41).

5. A non-metallic pipe with thermal insulation properties according to claim 2, characterized in that, A bracket (4) is provided at intervals of 0.5 to 2 m on the outside of the non-metallic tube body (1).

6. A method for manufacturing a non-metallic pipe with thermal insulation properties as described in claims 1-5, characterized in that, Includes the following steps: S1: Several supports (4) are sleeved along the axial direction of the non-metallic tube body (1), and then the non-metallic tube body (1) with the supports (4) is inserted into the polyethylene outer protective tube (3), so that the free ends of the several supports (4) abut against the polyethylene outer protective tube (3), thereby completing the fixation of the non-metallic tube body (1) and the polyethylene outer protective tube (3). The outer wall of the non-metallic tube body (1) and the inner wall of the polyethylene outer protective tube (3) form a heat insulation cavity. S2: The insulation material is injected into the insulation layer cavity, foamed, and then cured to obtain the non-metallic pipe with insulation properties.

7. A method for manufacturing a non-metallic pipe with thermal insulation properties according to claim 6, characterized in that, During the foaming process, the foaming temperature is 18~30℃, the insulation time is 38~40 s, and the fiber time is 206~210 s.

8. A method for manufacturing a non-metallic pipe with thermal insulation properties according to claim 6, characterized in that, During the curing process, the free throw density was monitored to be 33~35 kg / m³. 3 .

9. A method for manufacturing a non-metallic pipe with thermal insulation properties according to claim 6, characterized in that, During the curing process, the curing time is 2-4 hours at room temperature.

10. A method for manufacturing a non-metallic pipe with thermal insulation properties according to claim 6, characterized in that, In step S1, before installing several supports (4) along the axial direction of the non-metallic tube body (1), the surface of the non-metallic tube body (1) is cleaned. The cleaning process specifically involves washing the surface of the non-metallic tube body (1) with water.

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