Novel ultra-pure chemical conveying pipeline and preparation method

Abstract

The invention provides a novel ultra-pure chemical conveying pipeline. The novel ultra-pure chemical conveying pipeline comprises a metal outer pipe and a plastic inner pipe. The end of the plastic inner pipe extends out of the metal outer pipe in the axial direction of the metal outer pipe, an injection molding layer is fixedly connected to the outer wall, located on the outer side of the metal outer pipe, of the plastic inner pipe in the circumferential direction, and the end face, away from one side of the metal outer pipe, of the injection molding layer is flush with the end face of the plastic inner pipe. And no chamfered surface or rounded surface exists between the end face of the plastic inner pipe and the end face of the injection molding layer. The invention further provides a method for preparing the lining plastic pipe. The method comprises the following steps that the inner plastic pipe is sleeved with the outer metal pipe, the end face of the inner plastic pipe abuts against the bottom face of an injection mold, an injection molding area is formed between the injection mold and the outer wall of the inner plastic pipe, and an injection molding layer is formed after injection molding materials are injected into the injection molding area. Through the composite structure of the plastic inner pipe and the metal outer pipe, the high-strength characteristic of the metal pipeline is reserved, the excellent corrosion resistance of the plastic pipeline is exerted, and the plastic pipeline is particularly suitable for conveying high-purity chemicals.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical equipment, and specifically to a novel ultrapure chemical delivery pipeline. The plastic-lined pipe realizes residue-free, efficient and safe delivery of chemicals through a unique structural design, and is particularly suitable for chemical production environments with extremely high requirements for material purity.

[0002] The invention also relates to a method for preparing a novel ultrapure chemical delivery pipeline. Background Art

[0003] In high-tech fields such as semiconductors, biomedicine, and electronic materials, the purity of chemicals directly affects the quality and performance of the final product. When conveying high-purity chemicals, traditional metal pipelines are prone to chemical contamination due to factors such as metal surface roughness, oxide layer, and corrosion. To solve this problem, the industry usually uses plastic-lined pipes as conveying pipelines.

[0004] Existing plastic-lined pipes usually use a flanging process to form an outer edge that contacts the adjacent pipe fittings on the edge of the plastic pipe. The flanging process is specifically a stamping process that uses a mold to turn the hole edge or outer edge on the sheet material into a full edge. However, the outer flanging formed by the flanging process will form a chamfer between the inner wall of the plastic inner pipe and the end face of the plastic inner pipe. After the plastic-lined pipe is connected and fixed to the adjacent pipe fittings, a groove will be formed at the connection. Due to the frequent design defects at the connection, chemical residues will be caused, affecting the transportation efficiency and purity.

[0005] The patent with application number CN201810673204.X discloses an improved plastic-lined pipe, including a metal pipe and an inner plastic-lined pipe. Compared with the prior art, the plastic inner pipe of the plastic-lined pipe of the present invention is sealed and connected to the metal outer pipe through a rough surface and a sealing ring; adjacent plastic-lined pipes are sealed and connected through a straight pipe or a joint, and the adjacent plastic-lined pipes and connecting parts are further fastened by a clamp. The installation of the plastic-lined pipe is simple and easy, and the inner plastic pipe and the outer metal pipe and the adjacent plastic-lined pipes are tightly connected. The inner plastic-lined pipe is tightly connected to the outer metal pipe. When conveying a medium with a large temperature difference with the environment, the service life of the plastic-lined pipe is greatly improved, saving the production cost of the pharmaceutical factory and improving the production efficiency. It is easy to replace and flexible to assemble. Pharmaceutical manufacturers can adjust the length of the plastic-lined pipe and the materials of the metal pipe and the plastic pipe according to actual needs.

[0006] However, the above patented technology will also form grooves at the joints and cannot overcome the problem of chemical residues. Summary of the invention

[0007] The object of the present invention is to provide a novel ultrapure chemical delivery pipeline to solve the problems raised in the above background technology:

[0008] (1) How to effectively reduce the residual chemicals during the transportation process and improve the transportation efficiency and purity of chemicals by optimizing the design of the plastic-lined pipe structure.

[0009] The present invention also aims to provide a method for preparing a novel ultrapure chemical transport pipeline.

[0010] To achieve the above object, the present invention provides the following technical solutions:

[0011] A novel ultrapure chemical delivery pipeline comprises a metal outer tube and a plastic inner tube, wherein the plastic inner tube is sleeved inside the metal outer tube;

[0012] The end of the plastic inner tube extends outwardly of the metal outer tube along the axial direction of the metal outer tube, and the outer wall of the plastic inner tube outside the metal outer tube is fixedly connected with an injection molding layer along its circumferential direction, and the end surface of the injection molding layer away from the metal outer tube is flush with the end surface of the plastic inner tube;

[0013] In any cross section along the axial direction of the plastic inner tube, the inner wall of the plastic inner tube is perpendicular to the end surface of the plastic inner tube and the end surface of the injection molding layer.

[0014] Based on the above technical solution, the present invention can also be improved as follows.

[0015] Furthermore, a flange portion is provided at the end of the metal outer tube along its circumferential direction, and the injection molding layer is coated on the outside of the flange portion.

[0016] Furthermore, the metal outer tube includes a straight tube portion and at least one connecting tube portion, the straight tube portion is fixedly connected to the connecting tube portion, there is a gap between the inner wall of the connecting tube portion and the outer wall of the plastic inner tube, and the injection molding layer fills the gap between the connecting tube portion and the plastic inner tube.

[0017] Furthermore, a plurality of positioning holes are opened on the side wall of the connecting pipe part, and the injection molding layer fills up the spaces in the positioning holes.

[0018] After adopting such a structure, in any cross-section along the axial direction of the plastic inner tube, the inner wall of the plastic inner tube is perpendicular to the end face of the plastic inner tube and the end face of the injection molding layer, that is, there will be no chamfered surface or rounded surface between the end face of the plastic inner tube and the end face of the injection molding layer. Therefore, when adjacent new ultra-pure chemical transportation pipelines are butt-jointed, the purpose of seamless connection of the plastic inner tubes of the two can be achieved.

[0019] The beneficial effects of the novel ultrapure chemical delivery pipeline are:

[0020] (1) No-residue design: By optimizing the structural design of the connection, it is ensured that no chemicals remain inside the pipeline during the transportation process, thereby improving the purity of the chemicals.

[0021] (2) Efficient transportation: The smooth inner wall and the non-chamfered end face design reduce fluid resistance and improve transportation efficiency.

[0022] (3) Safe and reliable: The combined structure of metal outer tube and plastic inner tube not only ensures the strength of the pipeline, but also avoids the contamination of chemicals by metal, thus improving the safety of use.

[0023] (4) Easy to install and maintain: The flange connection design simplifies the installation process and facilitates subsequent inspection and maintenance work.

[0024] To achieve the above object, the present invention provides the following technical solutions:

[0025] A method for preparing the novel ultrapure chemical delivery pipeline described above comprises the following steps:

[0026] a) The plastic inner tube is sleeved inside the metal outer tube, and the end of the plastic inner tube extends outward from the metal outer tube along the axial direction of the metal outer tube;

[0027] b) placing the end of the plastic inner tube and the end of the metal outer tube together in an injection mold, with the end face of the plastic inner tube resting against the bottom face of the injection mold, forming an injection molding area between the injection mold and the outer wall of the plastic inner tube, and injecting injection plastic into the injection molding area to form an injection molding layer.

[0028] The method for preparing a novel ultrapure chemical delivery pipeline has the following beneficial effects:

[0029] (1) Perfect combination of high strength and corrosion resistance: The composite structure of plastic inner tube and metal outer tube not only retains the high strength characteristics of metal pipes, but also brings into play the excellent corrosion resistance of plastic pipes, which is particularly suitable for the transportation of high-purity chemicals.

[0030] (2) Excellent sealing performance: The injection molding layer tightly wraps the plastic inner tube and the metal outer tube, effectively preventing medium leakage and improving the safety of the pipeline system.

[0031] (3) Simple process and low cost: Compared with the traditional manufacturing process, the method of the present invention has clear steps, is easy to realize automated production, and reduces production costs.

[0032] (4) Broad application prospects: It can be widely used in industries such as chemical, pharmaceutical, semiconductor, etc. that require the transportation of high-purity chemicals, and has significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a front view of an embodiment of the novel ultrapure chemical delivery pipeline.

[0034] Figure 2 yes Figure 1 sectional view of .

[0035] Figure 3 yes Figure 2Enlarged view of part A.

[0036] Description of the numbers in the figure:

[0037] Metal outer tube 100; straight tube portion 110; connecting tube portion 120; positioning hole 121; flange portion 130; plastic inner tube 200; injection molding layer 300. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific implementation disclosed below.

[0039] The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementations.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0041] See also Figures 1 to 3 .

[0042] The novel ultrapure chemical delivery pipeline includes a metal outer pipe 100 and a plastic inner pipe 200 .

[0043] The metal outer tube 100 includes a straight tube portion 110 and two connecting tube portions 120. The two connecting tube portions 120 are respectively welded on both sides of the straight tube portion 110. The straight tube portion 110 and the connecting tube portions 120 are welded and fixed. The connecting tube portion 120 is in a trumpet shape. There is a gap between the inner wall of the connecting tube portion 120 and the outer wall of the plastic inner tube 200. The gap is tightly filled with the injection molding layer 300 to isolate the potential influence of the external environment on the plastic inner tube 200. The side wall of the connecting tube portion 120 is provided with a plurality of positioning holes 121 along its circumferential direction.

[0044] Flange portions 130 are respectively provided on both sides of the metal outer tube 100 , and the flange portions 130 are welded and fixed to the end surface of the connecting tube portion 120 away from the straight tube portion 110 .

[0045] The plastic inner tube 200 is sleeved in the metal outer tube 100, and the end of the plastic inner tube 200 extends out of the metal outer tube 100 and the flange portion 130 along the axial direction of the metal outer tube 100. The outer wall of the plastic inner tube 200 outside the metal outer tube 100 is fixed with an injection layer 300 along its circumferential direction. The end face of the injection layer 300 away from the metal outer tube 100 is flush with the end face of the plastic inner tube 200. The injection layer 300 is coated on the outside of the flange portion 130. The injection layer 300 fills the gap between the connecting tube portion 120 and the plastic inner tube 200, and the injection layer 300 fills the space of the positioning hole 121. The injection layer 300 not only enhances the strength of the connection between the plastic inner tube 200 and the metal outer tube 100, but also ensures that the end face of the injection layer 300 away from the metal outer tube 100 is flush with the end face of the plastic inner tube 200, forming a smooth transition and avoiding the accumulation of chemicals there.

[0046] In any cross section along the axial direction of the plastic inner tube 200 , the inner wall of the plastic inner tube 200 and the end surface of the plastic inner tube 200 and the end surface of the injection molding layer 300 are all in a vertical relationship.

[0047] In any cross section along the axis of the plastic inner tube 200, the inner wall of the plastic inner tube 200, the end face of the plastic inner tube 200 and the end face of the injection molding layer 300 all maintain a vertical relationship. This design ensures that when the pipelines are connected, the end faces of the plastic inner tubes 200 of two adjacent new ultra-pure chemical delivery pipelines can directly contact each other, and there is no chamfer or notch between the two, thereby completely eliminating the possibility of chemical residues.

[0048] The method for preparing the novel ultrapure chemical delivery pipeline as described above comprises the following steps:

[0049] a) Select corrosion-resistant plastic materials that meet the requirements of the conveying medium, such as polytetrafluoroethylene (PTFE), polyethylene (PE) or polypropylene (PP), and make a plastic inner tube 200 through extrusion, injection molding or other molding processes. Then, the plastic inner tube 200 is accurately inserted into the pre-prepared metal outer tube 100 to ensure that the two fit tightly but not too tight, and the end of the plastic inner tube 200 extends out of the metal outer tube 100 and the flange 130 along the axial direction of the metal outer tube 100.

[0050] b) Place the assembled plastic inner tube 200 and the metal outer tube 100 together in a special injection mold. Adjust the mold position so that the extended end surface of the plastic inner tube 200 accurately rests on the bottom surface of the injection mold, ensuring that the plastic layer can evenly cover and fit tightly between the metal outer tube 100 and the plastic inner tube 200 during injection molding. At this time, a closed injection molding area is formed between the injection mold and the outer wall of the plastic inner tube 200. Next, an injection plastic that has been pre-heated to a molten state, such as polyvinyl chloride (PVC), epoxy resin, etc., is injected into the injection molding area, and the injection plastic is filled in the injection molding area and solidified through high-pressure injection molding to form a solid injection molding layer 300. The injection molding layer 300 not only enhances the overall strength of the pipeline, but also further improves the corrosion resistance and sealing of the pipeline.

[0051] c) Post-processing and testing:

[0052] After the injection molding is completed, the new ultra-pure chemical delivery pipeline is taken out of the mold for necessary cooling, trimming and inspection. The inspection content includes but is not limited to the appearance quality, dimensional accuracy, sealing performance and corrosion resistance of the pipeline to ensure that the prepared plastic-lined pipeline meets the design requirements and industry standards.

[0053] The above is only one embodiment of the present invention. It should be pointed out that a person skilled in the art may make several modifications and improvements without departing from the principle of the present invention, and these should also be regarded as falling within the scope of protection of the present invention.

Claims

1. A novel ultrapure chemical delivery pipeline, comprising a metal outer tube (100) and a plastic inner tube (200), wherein the plastic inner tube (200) is sleeved inside the metal outer tube (100), and is characterized by: The end of the plastic inner tube (200) extends out of the metal outer tube (100) along the axial direction of the metal outer tube (100); the outer wall of the plastic inner tube (200) outside the metal outer tube (100) is fixedly connected with an injection molding layer (300) along its circumferential direction; and the end surface of the injection molding layer (300) on the side away from the metal outer tube (100) is flush with the end surface of the plastic inner tube (200); In any cross section along the axial direction of the plastic inner tube (200), the inner wall of the plastic inner tube (200) and the end surface of the plastic inner tube (200) and the end surface of the injection molding layer (300) are all in a vertical relationship.

2. The novel ultrapure chemical delivery pipeline according to claim 1 is characterized by: The end of the metal outer tube (100) is provided with a flange portion (130) along its circumferential direction, and the injection molding layer (300) is coated on the outside of the flange portion (130).

3. The novel ultrapure chemical delivery pipeline according to claim 1 is characterized by: The metal outer tube (100) comprises a straight tube portion (110) and at least one connecting tube portion (120); the straight tube portion (110) is fixedly connected to the connecting tube portion (120); a gap is provided between the inner wall of the connecting tube portion (120) and the outer wall of the plastic inner tube (200); and the injection molding layer (300) fills the gap between the connecting tube portion (120) and the plastic inner tube (200).

4. The novel ultrapure chemical delivery pipeline according to claim 1 is characterized by: A plurality of positioning holes (121) are formed on the side wall of the connecting pipe portion (120), and the injection molding layer (300) fills up the spaces in the positioning holes (121).

5. A method for preparing a novel ultrapure chemical delivery pipeline as claimed in any one of claims 1 to 4, comprising the following steps: a) the plastic inner tube (200) is sleeved inside the metal outer tube (100), and the end of the plastic inner tube (200) extends out of the metal outer tube (100) along the axial direction of the metal outer tube (100); b) placing the end of the plastic inner tube (200) and the end of the metal outer tube (100) together in an injection mold, with the end face of the plastic inner tube (200) resting against the bottom face of the injection mold, forming an injection molding area between the injection mold and the outer wall of the plastic inner tube (200), and injecting injection plastic into the injection molding area to form an injection molding layer (300).

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