Corrosion-resistant high-pressure steam pipeline and preparation method thereof

Abstract

The invention relates to the technical field of high-pressure steam pipelines, and provides a corrosion-resistant high-pressure steam pipeline and a preparation method thereof. The anti-corrosion high-pressure steam pipeline sequentially comprises a pipeline cavity, an anti-corrosion layer and a protection layer from inside to outside. The material of the anticorrosive layer is a powder coating, the material of the protective layer is a polyethylene tape, and the powder coating is prepared from the following raw materials in parts by weight: 70-80 parts of epoxy resin, 15-20 parts of a curing agent, 1-2 parts of a curing accelerator, 10-15 parts of filler, 1-4 parts of pigment, 0.5-1 part of a flatting agent, 1-2 parts of a defoaming agent and 1-1.5 parts of an antioxidant. The filler is prepared from the following raw materials: mica powder, polyvinylpyrrolidone and trifluoroacetamide; the mass ratio of the mica powder to the polyvinylpyrrolidone to the trifluoroacetamide is 20: 2: (0.5-2). By means of the technical scheme, the problem that in the prior art, a high-pressure steam pipeline is poor in corrosion resistance is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of high-pressure steam pipelines, and specifically, to a corrosion-resistant high-pressure steam pipeline and a preparation method thereof. Background Art

[0002] In modern industrial production, high-pressure steam, as an important energy carrier, is widely used in many fields such as electric power, chemical industry, petroleum, and pharmaceuticals. As a key component for transporting high-pressure steam, the performance of high-pressure steam pipelines is directly related to the safe, stable, and efficient operation of the entire industrial production system. During the actual use of high-pressure steam pipelines, the outer wall of the pipeline faces extremely complex and harsh environmental challenges. On the one hand, high-pressure steam pipelines are usually laid outdoors or inside industrial plants and are exposed to the atmospheric environment for a long time, and will be eroded by oxygen, moisture, acidic gases, and industrial pollutants in the air; on the other hand, some pipelines will pass through areas with different geological conditions, and factors such as moisture, pH value, and microorganisms in the soil will also cause corrosion to the outer wall of the pipeline, thereby reducing the strength and service life of the pipeline. Therefore, developing a high-pressure steam pipeline with excellent corrosion resistance has become an important issue to be solved in the current industrial field. Summary of the Invention

[0003] The present invention provides a corrosion-resistant high-pressure steam pipeline and a preparation method thereof, which solve the problem of poor corrosion resistance of high-pressure steam pipelines in related technologies.

[0004] The technical solution of the present invention is as follows: The present invention provides a corrosion-resistant high-pressure steam pipeline, which sequentially includes a pipeline cavity, an anti-corrosion layer, and a protective layer from the inside to the outside; the material of the anti-corrosion layer is powder coating, the material of the protective layer is polyethylene tape, and the powder coating includes raw materials with the following weight parts: 70-80 parts of epoxy resin, 15-20 parts of curing agent, 1-2 parts of curing accelerator, 10-15 parts of filler, 1-4 parts of pigment, 0.5-1 part of leveling agent, 1-2 parts of defoaming agent, and 1-1.5 parts of antioxidant; The raw materials of the filler include mica powder, polyvinylpyrrolidone, and trifluoroacetamide; the mass ratio of mica powder, polyvinylpyrrolidone, and trifluoroacetamide is 20:2:0.5-2.

[0005] As a further technical solution, the mass ratio of mica powder, polyvinylpyrrolidone, and trifluoroacetamide is 20:2:0.8-1.5.

[0006] In the present invention, by limiting the mass ratio of mica powder, polyvinylpyrrolidone, and trifluoroacetamide to 20:2:0.8-1.5, the corrosion resistance of the high-pressure steam pipeline is further improved.

[0007] As a further technical solution, the polyvinylpyrrolidone includes a first polyvinylpyrrolidone and a second polyvinylpyrrolidone; the weight-average molecular weight of the first polyvinylpyrrolidone is 3500; the weight-average molecular weight of the second polyvinylpyrrolidone is 32000.

[0008] In the present invention, by using polyvinylpyrrolidones with two different weight-average molecular weights, the compatibility between mica powder and the matrix is improved, and the adhesion of the powder coating on the outer wall of the pipeline is enhanced.

[0009] As a further technical solution, the mass ratio of the first polyvinylpyrrolidone to the second polyvinylpyrrolidone is 2:3 to 5.

[0010] In the present invention, by limiting the mass ratio of the first polyvinylpyrrolidone to the second polyvinylpyrrolidone to 2:3 to 5, the adhesion of the powder coating on the outer wall of the pipeline is further improved.

[0011] As a further technical solution, the preparation method of the filler includes the following steps: S1. Adding mica and polyvinylpyrrolidone into a solvent and mixing to obtain a mixed solution; S2. Adding trifluoroacetamide into the mixed solution, stirring and drying to obtain the filler.

[0012] As a further technical solution, the solvent is ethanol.

[0013] As a further technical solution, the temperature of the mixing is 40°C, and the time of the mixing is 1 to 3 h.

[0014] As a further technical solution, the temperature of the stirring is 40°C, and the time of the stirring is 1 to 3 h.

[0015] As a further technical solution, the preparation method of the powder coating includes the following steps: mixing each raw material component, and then obtaining the powder coating through heating, tablet pressing, and pulverization.

[0016] As a further technical solution, the epoxy resin is bisphenol A type epoxy resin.

[0017] In the present invention, bisphenol A type epoxy resin contains a large number of epoxy groups and hydroxyl groups, which can undergo cross-linking reactions with various curing agents to form a three-dimensional network structure, greatly improving the stability of the coating. When the coating faces a complex environment, it can maintain a stable structure and effectively resist the erosion of corrosive components.

[0018] Among them, the bisphenol A type epoxy resin can be, for example, one or more of E-51, E-12, E-44, and E-20, and preferably E-51 and E-12.

[0019] As a further technical solution, the curing agent includes one or both of phthalic anhydride and m-phenylenediamine.

[0020] As a further technical solution, the curing accelerator is 2-methylimidazole.

[0021] As a further technical solution, the leveling agent is polydimethylsiloxane.

[0022] As a further technical solution, the defoaming agent is an organosilicon defoaming agent.

[0023] As a further technical solution, the antioxidant includes one or both of antioxidant 1076 and antioxidant 1098.

[0024] As a further technical solution, the pigment includes one or both of titanium dioxide and zinc oxide.

[0025] The present invention also provides a method for preparing a corrosion-resistant high-pressure steam pipeline, comprising the following steps: S1. Heat the inner cavity of the pipeline and then spray a powder coating on the outer side to form an anti-corrosion layer; S2. Wrap a polyethylene tape around the outer side of the anti-corrosion layer to form a protective layer, obtaining a semi-finished high-pressure steam pipeline; S3. Heat and then cool the semi-finished high-pressure steam pipeline to obtain a corrosion-resistant high-pressure steam pipeline.

[0026] As a further technical solution, the thickness of the anti-corrosion layer is 500 μm.

[0027] As a further technical solution, the number of layers of the polyethylene tape wrapped is 3 layers.

[0028] The working principle and beneficial effects of the present invention are as follows: In the present invention, the high-pressure steam pipeline is composed of a pipeline inner cavity, an anti-corrosion layer, and a protective layer. The anti-corrosion layer is a powder coating, which can tightly adhere to the outer wall of the pipeline, forming a dense protective film to prevent corrosive substances from corroding the pipe wall. The protective layer is a polyethylene tape, which has good chemical stability and water resistance and can protect the anti-corrosion layer, extending the service life of the high-pressure steam pipeline. A filler composed of mica powder, polyvinylpyrrolidone, and trifluoroacetamide is added to the powder coating, improving the corrosion resistance of the powder coating and further enhancing the corrosion resistance of the high-pressure steam pipeline, solving the problem of poor corrosion resistance of the high-pressure steam pipeline. Specific embodiments

[0029] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0030] In the following examples and comparative examples: Polyethylene tape, thickness 0.5 mm; polydimethylsiloxane, model: DC200; silicone defoamer, model: AFE-7610; polyvinylpyrrolidone of type PVP K12, MW: 3500; polyvinylpyrrolidone of type PVP K25, MW: 32000.

[0031] Example 1 A method for preparing a corrosion-resistant high-pressure steam pipeline, comprising the following steps: S1. After heating the pipe cavity, spray powder coating on the outer side to form an anti-corrosion layer with a thickness of 500 μm; S2. Wrap 3 layers of polyethylene tape on the outer side of the anti-corrosion layer to form a protective layer, obtaining a semi-finished high-pressure steam pipeline; S3. Heat and cool the semi-finished high-pressure steam pipeline to obtain a corrosion-resistant high-pressure steam pipeline; Preparation method of the powder coating: Mix 70 parts of bisphenol A epoxy resin E-51, 15 parts of phthalic anhydride, 1 part of 2-methylimidazole, 10 parts of filler, 1 part of titanium dioxide, 0.5 part of polydimethylsiloxane, 1 part of silicone defoamer, and 1 part of antioxidant 1076 evenly, and then obtain the powder coating through heating, tablet pressing, and pulverization; Preparation method of the filler: S1. Add 40 g of mica and 4 g of polyvinylpyrrolidone PVP K12 to 300 mL of ethanol, heat to 40 °C, and stir for 1 h to obtain a mixed solution; S2. Add 1 g of trifluoroacetamide to the mixed solution and continue to stir at 40 °C for 3 h, and then obtain the filler through drying.

[0032] Example 2 A method for preparing a corrosion-resistant high-pressure steam pipeline, comprising the following steps: S1. After heating the pipe cavity, spray powder coating on the outer side to form an anti-corrosion layer with a thickness of 500 μm; S2. Wrap 3 layers of polyethylene tape on the outer side of the anti-corrosion layer to form a protective layer, obtaining a semi-finished high-pressure steam pipeline; S3. Heat and cool the semi-finished high-pressure steam pipeline to obtain a corrosion-resistant high-pressure steam pipeline; Preparation method of the powder coating: 80 parts of bisphenol A epoxy resin E-12, 20 parts of m-phenylenediamine, 2 parts of 2-methylimidazole, 15 parts of filler, 4 parts of zinc oxide, 1 part of polydimethylsiloxane, 2 parts of silicone defoamer, and 1.5 parts of antioxidant 1098 were mixed evenly and then obtained the powder coating through heating, tablet pressing, and pulverization; Preparation method of the filler: S1. 40 g of mica and 4 g of polyvinylpyrrolidone PVP K12 were added to 300 mL of ethanol, heated to 40 °C, and stirred for 3 h to obtain a mixed solution; S2. 1 g of trifluoroacetamide was added to the mixed solution and stirred at 40 °C for 1 h, and then the filler was obtained through drying.

[0033] Example 3 Compared with Example 2, the only difference in this example is that the addition amount of trifluoroacetamide is 4 g.

[0034] Example 4 Compared with Example 2, the only difference in this example is that the addition amount of trifluoroacetamide is 1.6 g.

[0035] Example 5 Compared with Example 2, the only difference in this example is that the addition amount of trifluoroacetamide is 3 g.

[0036] Example 6 Compared with Example 5, the only difference in this example is that polyvinylpyrrolidone PVP K12 is replaced with an equal amount of polyvinylpyrrolidone PVP K25.

[0037] Example 7 Compared with Example 5, the only difference in this example is that polyvinylpyrrolidone PVP K12 is replaced with an equal amount of a 1:1 mass ratio of polyvinylpyrrolidone PVP K12 and polyvinylpyrrolidone PVP K25.

[0038] Example 8 Compared with Example 7, the only difference in this example is that the mass ratio of polyvinylpyrrolidone PVP K12 and polyvinylpyrrolidone PVP K25 is 1:3.

[0039] Example 9 Compared with Example 7, the only difference in this example is that the mass ratio of polyvinylpyrrolidone PVP K12 and polyvinylpyrrolidone PVP K25 is 2:3.

[0040] Example 10 Compared with Example 7, the only difference in this example is that the mass ratio of polyvinylpyrrolidone PVP K12 and polyvinylpyrrolidone PVP K25 is 2:5.

[0041] Comparative Example 1 Compared with Example 1, the only difference in this comparative example is that the filler is mica powder.

[0042] Comparative Example 2 Compared with Example 1, the only difference in this comparative example is the preparation method of the filler: 40 g of mica and 4 g of polyvinylpyrrolidone PVP K12 were added to 300 mL of ethanol, heated to 40 °C and stirred for 1 h, and then dried to obtain the filler.

[0043] Comparative Example 3 Compared with Example 1, the only difference in this comparative example is the preparation method of the filler: 40 g of mica and 1 g of trifluoroacetamide were added to 300 mL of ethanol, heated to 40 °C and stirred for 1 h, and then dried to obtain the filler.

[0044] Experimental Example 1 The powder coatings prepared in Examples 1 to 5 and Comparative Examples 1 to 3 were tested for acid salt spray resistance according to the method in HG / T 2006-2022 "Thermosetting and Thermoplastic Powder Coatings". The substrate was a steel plate, the dry film thickness was 60 μm, and the time when the one-way corrosion at the scribed line was ≤ 4 mm and there was no abnormality at the non-scribed line was tested. The test results are shown in Table 1.

[0045] Table 1 Test results of salt spray resistance of powder coatings

[0046] As can be seen from Table 1, the acid salt spray resistance time of the powder coatings prepared in Examples 1 to 5 is longer than that of Comparative Examples 1 to 3, indicating that when the filler is composed of mica powder, polyvinylpyrrolidone, and trifluoroacetamide, and the mass ratio of mica powder, polyvinylpyrrolidone, and trifluoroacetamide is 20:2:0.5 to 2, the corrosion resistance of the powder coating can be improved.

[0047] Experimental Example 2 The powder coatings prepared in Examples 5 to 10 were tested for wet adhesion according to the method specified in HG / T 2006-2022 "Thermosetting and Thermoplastic Powder Coatings". The test results are shown in Table 2.

[0048] Table 2 Test results of adhesion of powder coatings

[0049] As can be seen from Table 2, the wet adhesion performance of the powder coatings prepared in Examples 9 to 10 is better than that of Examples 5 to 8, indicating that when polyvinylpyrrolidone is composed of polyvinylpyrrolidone PVP K12 and polyvinylpyrrolidone PVP K25 with a mass ratio of 2:3 to 5, the adhesion of the powder coating can be improved.

[0050] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A corrosion-resistant high-pressure steam pipeline, characterized in that: From inside to outside, it includes a pipeline cavity, an anti-corrosion layer, and a protective layer; the material of the anti-corrosion layer is powder coating, the material of the protective layer is polyethylene tape, and the powder coating includes the following raw materials in parts by weight: 70-80 parts of epoxy resin, 15-20 parts of curing agent, 1-2 parts of curing accelerator, 10-15 parts of filler, 1-4 parts of pigment, 0.5-1 parts of leveling agent, 1-2 parts of defoaming agent, and 1-1.5 parts of antioxidant; The raw materials of the filler include mica powder, polyvinyl pyrrolidone and trifluoroacetamide; the mass ratio of the mica powder, polyvinyl pyrrolidone and trifluoroacetamide is 20:2:0.5~2.

2. The corrosion-resistant high-pressure steam pipeline according to claim 1, characterized in that: The mass ratio of the mica powder, polyvinyl pyrrolidone and trifluoroacetamide is 20:2:0.8-1.

5.

3. The corrosion-resistant high-pressure steam pipeline according to claim 2, characterized in that: The polyvinyl pyrrolidone includes a first polyvinyl pyrrolidone and a second polyvinyl pyrrolidone; the weight average molecular weight of the first polyvinyl pyrrolidone is 3500; the weight average molecular weight of the second polyvinyl pyrrolidone is 32000.

4. The corrosion-resistant high-pressure steam pipeline according to claim 3, characterized in that: The mass ratio of the first polyvinyl pyrrolidone to the second polyvinyl pyrrolidone is 2:3-5.

5. The corrosion-resistant high-pressure steam pipeline according to claim 1, characterized in that: The preparation method of the filler comprises the following steps: S1, adding mica and polyvinyl pyrrolidone into a solvent and mixing to obtain a mixed solution; S2, adding trifluoroacetamide to the mixed solution, stirring, and drying to obtain a filler.

6. The corrosion-resistant high-pressure steam pipeline according to claim 1, characterized in that: The epoxy resin is bisphenol A type epoxy resin.

7. The corrosion-resistant high-pressure steam pipeline according to claim 1, characterized in that: The curing agent includes one or two of phthalic anhydride and meta-phenylenediamine.

8. The corrosion-resistant high-pressure steam pipeline according to claim 1, characterized in that: The antioxidant includes one or both of antioxidant 1076 and antioxidant 1098.

9. The corrosion-resistant high-pressure steam pipeline according to claim 1, characterized in that: The pigment includes one or both of titanium dioxide and zinc oxide.

10. The method for preparing a corrosion-resistant high-pressure steam pipeline according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. After heating the pipe cavity, spray powder coating on the outside to form an anti-corrosion layer; S2, wrapping a polyethylene tape around the outside of the anti-corrosion layer to form a protective layer, to obtain a semi-finished high-pressure steam pipeline; S3, heating and cooling the semi-finished high-pressure steam pipeline to obtain a corrosion-resistant high-pressure steam pipeline.

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