Processing method of composite finned tube

Abstract

The invention discloses a machining method of a composite finned tube. The machining method comprises the following steps that firstly, a base tube and an aluminum tube are prepared; secondly, the base pipe penetrates into the aluminum pipe; thirdly, the base pipe and the aluminum pipe are composited for the first time in an extrusion mode, the first composite pipe is drawn again through a drawing machine tool, the aluminum pipe and the base pipe are completely composited, and a composite pipe is formed; fourthly, a spiral groove is formed in the composite pipe; fifthly, the aluminum strip with the rectangular section is wound through tension and embedded into the spiral groove in the outer surface of the composite pipe through a mechanical method; and sixthly, redundant aluminum fins at the two ends of the product are removed through a puller. The method relates to the technical field of finned tube machining. Compared with an existing product of the same specification, it can be guaranteed that the thickness of the base pipe is not reduced, meanwhile, the aluminum pipe compounded on the base pipe can effectively protect the base pipe against oxidation and rusting, the purpose of prolonging the service life is achieved, and meanwhile the heat exchange efficiency is increased by 22%-36% compared with an existing product in the aspect of the using function.

Description

Technical Field

[0001] The invention relates to the technical field of fin tube processing, in particular to a processing method of a composite fin tube. Background Art

[0002] In order to meet the requirements of cooling medium of air cooler, there are various types of fin tubes. The commonly used fin tube types in the prior art are as follows: L-type fin tube, LL-type fin tube, KL-type fin tube, DR-type fin tube, G-type fin tube and H-type fin tube, etc.

[0003] However, the production process of DR finned tubes is to first mechanically combine the aluminum outer sleeve and the base tube to extrude aluminum fins. Rolling emulsified oil is required in the production process, and the finished product must be cleaned with sodium hydroxide solution to remove grease from the surface, which will result in the discharge of wastewater and cause certain pollution. Secondly, the production process of DR finned tubes is to put an aluminum outer sleeve with a certain thickness on the base tube and extrude it with three sets of blades to achieve a certain fin height. The production process uses about 1 kg of aluminum per meter, which consumes a lot of aluminum resources, and the products produced are not cost-effective.

[0004] The production process of G-type finned tubes is to directly open a spiral groove with a depth of about 0.3 on the outer surface of the base tube, and then embed the aluminum strip into the spiral groove. The production process determines that the base tube must be damaged. At the same time, the gap between the fins embedded in the spiral groove is directly in contact with the external air without the aluminum sleeve protection layer, which poses a risk of rust and corrosion.

[0005] To this end, the present invention provides a method for processing a composite fin tube to solve the above problems. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a method for processing a composite fin tube to solve the above problems.

[0007] To achieve the above purpose, the present invention is implemented by the following technical scheme: a processing method of a composite fin tube, the steps are as follows:

[0008] The first step is to prepare the base tube and the aluminum tube;

[0009] The second step is to insert the base tube into the aluminum tube;

[0010] The third step is to compound the base tube and the aluminum tube for the first time by extrusion, and then use a stretching machine to draw the first composite tube again, so that the aluminum tube and the base tube are completely compounded to form a composite tube;

[0011] The fourth step is to open a spiral groove on the composite pipe;

[0012] In the fifth step, the aluminum strip of rectangular cross section is wound with tension and mechanically embedded into the spiral groove on the outer surface of the composite tube;

[0013] Step 6: Use a pulling machine to remove the excess aluminum fins at both ends of the product until the base tube is exposed;

[0014] The seventh step is to use a stapler or a fixing ring to perform head sealing to form a composite inlaid fin tube.

[0015] Preferably, the outer diameter of the base tube is 19-38 mm, the outer diameter of the aluminum tube differs from that of the base tube by 3 mm, and the wall thickness of the aluminum tube is 1 mm.

[0016] Preferably, the extrusion between the base tube and the aluminum tube is performed by extruding the aluminum tube onto the surface of the base tube through three sets of rollers of the composite machine tool, so that a thin bottom layer is formed outside the base tube to wrap the base tube.

[0017] Preferably, the depth of the spiral groove is 0.3-0.4 mm.

[0018] Preferably, the outer diameter of the composite tube differs from that of the base tube by +1.6 mm, and the tolerance is ±0.1 mm.

[0019] Preferably, the aluminum strip has a width of 8 mm to 18 mm.

[0020] Preferably, the embedding spacing of the aluminum strip is 2mm-5mm.

[0021] Beneficial Effects

[0022] The present invention provides a method for processing a composite fin tube. Compared with the prior art, the method has the following beneficial effects:

[0023] (1) Compared with existing products of the same specification, the processing method of the composite finned tube can ensure that the thickness of the base tube will not be reduced. At the same time, the composite aluminum tube on the base tube can effectively protect the base tube from oxidation and rust, so as to achieve the purpose of increasing the service life. At the same time, compared with existing products, the heat exchange efficiency is increased by 22%-36% in terms of use function.

[0024] (2) The processing method of the composite finned tube does not require the surface of the finished composite inlaid finned tube to be cleaned, and wastewater will not be discharged. At the same time, the amount of aluminum used in the production process will be reduced, saving aluminum resources. Secondly, the production process is to open a spiral groove on the outer surface of the composite base tube, that is, the surface of the alloy aluminum tube, which will not damage the surface of the base tube. At the same time, the outer surface of the base tube is protected by the alloy aluminum tube and will not rust or corrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a flow chart of the present invention.

[0026] Figure 2 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Embodiment 1:

[0029] See also Figure 1 , a processing method of a composite fin tube, the steps are as follows:

[0030] The first step is to prepare the base tube and the aluminum tube;

[0031] In more detail, the outer diameter of the base tube is 19-38 mm, the difference between the outer diameter of the aluminum tube and the outer diameter of the base tube is 3 mm, and the wall thickness of the aluminum tube is 1 mm;

[0032] In this embodiment, the base pipe is cut into a finished product length by a cutting device;

[0033] The second step is to insert the base tube into the aluminum tube;

[0034] More specifically, in this embodiment, the model of the aluminum tube is 6063 alloy aluminum tube;

[0035] The third step is to compound the base tube and the aluminum tube for the first time by extrusion, and then use a stretching machine to draw the first composite tube again, so that the aluminum tube and the base tube are completely compounded to form a composite tube;

[0036] More specifically, the extrusion between the base tube and the aluminum tube involves extruding the aluminum tube onto the surface of the base tube through three sets of rollers on the compound machine tool, forming a thin bottom layer outside the base tube to wrap the base tube;

[0037] In more detail, the outer diameter of the composite tube differs from the outer diameter of the base tube by +1.6mm, and the tolerance is ±0.1mm;

[0038] The fourth step is to open a spiral groove on the composite pipe;

[0039] In more detail, the depth of the spiral groove is 0.3-0.4 mm to ensure that the fin is inserted into the groove and firmly connected in the groove, and the selection temperature of the fin in this embodiment refers to the temperature at the interface between the base tube and the fin under the highest normal working conditions, the maximum allowable use temperature is equivalent to the fin selection temperature, and the maximum allowable use temperature of the composite embedded fin tube is greater than 400°C;

[0040] In the fifth step, the aluminum strip of rectangular cross section is wound with tension and mechanically embedded into the spiral groove on the outer surface of the composite tube;

[0041] More specifically, the width of the aluminum strip is 8mm-18mm;

[0042] In more detail, the embedding spacing of the aluminum strip is 2mm-5mm;

[0043] Step 6: Use a pulling machine to remove the excess aluminum fins at both ends of the product until the base tube is exposed;

[0044] Step 7: Use a stapler or a fixing ring to perform head sealing to form a composite inlaid fin tube;

[0045] In summary, the outer diameter 19-38 base tube is inserted into the 6063 alloy aluminum tube [base tube outer diameter + 3mm] (aluminum tube outer diameter) × 1mm (aluminum tube wall thickness), and the base tube and the aluminum tube are first compounded by extrusion using a compound machine, and then the first composite tube is drawn again by a stretching machine, so that the aluminum tube and the base tube are completely compounded, and the outer diameter of the composite tube is controlled to the outer diameter of the base tube + 1.6mm (tolerance ± 0.1mm), and the rectangular cross-section aluminum strip (aluminum strip width 8mm-18mm) is wound with tension and mechanically embedded in the spiral groove on the outer surface of the composite tube, with an embedding spacing of 2mm-5mm, and then the excess aluminum fins at both ends of the product are removed by a head pulling machine to expose the base tube, and finally a stapler or a fixing ring is used for head sealing to form a composite inlaid fin tube;

[0046] In the production process of this embodiment, the spiral grooves are formed on the outer surface of the composite base tube, i.e., the surface of the alloy aluminum tube, which will not damage the surface of the base tube. At the same time, the outer surface of the base tube is protected by the alloy aluminum tube and will not be rusted or corroded.

[0047] Embodiment 2:

[0048] See also Figure 2 This embodiment provides a technical solution based on the first embodiment: in this embodiment, the diameter of the base tube is 25×2.5 mm, the model of the aluminum tube is 6063 alloy aluminum tube, and the outer diameter of the aluminum tube is 28 mm (base tube outer diameter + 3 mm) 1 mm (aluminum tube wall thickness);

[0049] In this embodiment, a 25×2.5 base tube is inserted into a 6063 alloy aluminum tube of 28 mm (outer diameter of the aluminum tube)×1 mm (wall thickness of the aluminum tube), the base tube and the aluminum tube are extruded and composited by a composite machine, and the composite tube is drawn again by a drawing machine, and the outer diameter of the composite tube is controlled to 26.6 mm. A rectangular cross-section aluminum strip (bandwidth 16.2 mm) is wound with tension and mechanically embedded in the spiral groove on the outer surface of the composite tube, with an embedding spacing of 2.3 mm±0.1 mm, and then the excess aluminum fins at both ends of the product are removed by a head pulling machine to expose the base tube, and finally a stapler or a fixing ring is used to perform head sealing to form a composite inlaid fin tube;

[0050] In summary, compared with existing products of the same specifications, the advantages of DR-type finned tubes and G-type finned tubes can be integrated, and the thickness of the base tube will not be reduced. At the same time, the composite aluminum tube on the base tube can effectively protect the base tube from oxidation and rust, so as to achieve the purpose of increasing the service life. At the same time, the heat exchange efficiency is increased by 22%-36% compared with existing products in terms of use function.

[0051] The composite inlaid fin tube does not need to be cleaned on the surface, and there will be no wastewater discharge. At the same time, the heat transfer coefficient is better than that of DR-type fin tubes and G-type fin tubes. At the same time, the operating temperature is greater than 400°C. With the lowest aluminum content, the base tube can be protected from rust and corrosion caused by the external environment.

[0052] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0053] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0054] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for processing a composite fin tube, characterized in that: Here are the steps: The first step is to prepare the base tube and the aluminum tube; The second step is to insert the base tube into the aluminum tube; The third step is to compound the base tube and the aluminum tube for the first time by extrusion, and then use a stretching machine to draw the first composite tube again, so that the aluminum tube and the base tube are completely compounded to form a composite tube; The fourth step is to open a spiral groove on the composite pipe; In the fifth step, the aluminum strip of rectangular cross section is wound with tension and mechanically embedded into the spiral groove on the outer surface of the composite tube; Step 6: Use a pulling machine to remove the excess aluminum fins at both ends of the product until the base tube is exposed; The seventh step is to use a stapler or a fixing ring to perform head sealing to form a composite inlaid fin tube.

2. The method for processing a composite fin tube according to claim 1, characterized in that: The outer diameter of the base tube is 19-38 mm, the outer diameter of the aluminum tube differs from that of the base tube by 3 mm, and the wall thickness of the aluminum tube is 1 mm.

3. The method for processing a composite fin tube according to claim 1, characterized in that: The extrusion between the base tube and the aluminum tube is performed by extruding the aluminum tube onto the surface of the base tube through three sets of rollers of the composite machine tool, so that a thin bottom layer is formed outside the base tube to wrap the base tube.

4. The method for processing a composite fin tube according to claim 1, characterized in that: The depth of the spiral groove is 0.3-0.4 mm.

5. The method for processing a composite fin tube according to claim 1, characterized in that: The outer diameter of the composite tube differs from that of the base tube by +1.6 mm, and the tolerance is ±0.1 mm.

6. The method for processing a composite fin tube according to claim 1, characterized in that: The width of the aluminum strip is 8mm-18mm.

7. The method for processing a composite fin tube according to claim 1, characterized in that: The embedding spacing of the aluminum strip is 2mm-5mm.

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