Apparatus and method for preparing a porous heat transfer coating on the surface of a metal tube

Abstract

This invention relates to an apparatus and method for preparing a porous heat transfer coating on the surface of a metal tube, comprising: a guide rail; a material storage mechanism through which the metal tube passes; a coating mechanism; a shaping wheel that contacts and compresses the material into a thin film; an illumination mechanism that irradiates the material; a laser device that melts the material onto the surface of the metal tube; a clamping rod that penetrates and supports the metal tube outwards; and a moving device that pulls the clamping rod to move. The moving device is movably mounted on the guide rail. The coating mechanism wraps the thin film around the shaping wheel. The material storage mechanism, the shaping wheel, and the laser device are sequentially arranged on the guide rail along the direction of movement of the metal tube. The illumination mechanism is spaced between the material storage mechanism, the shaping wheel, and the laser device. This invention solves the problem in existing solutions where the porous heat transfer coating thickness is inconsistent, making it impossible to form a complex porous structure and affecting heat exchange efficiency.

Description

Technical Field

[0001] This invention relates to the field of porous heat transfer tube technology, and in particular to an apparatus and method for preparing a porous heat transfer coating on the surface of a metal tube. Background Technology

[0002] The porous heat transfer coating on the heat transfer porous tube is prepared by first applying an adhesive to the surface of the metal tube, then spraying metal powder onto the adhesive, and after the adhesive dries, using a laser to melt the metal powder onto the surface of the metal tube to form a porous heat transfer coating.

[0003] This preparation method results in uneven metal powder spraying, leading to inconsistent thickness of the porous heat transfer coating and affecting heat exchange efficiency. Furthermore, the limited adhesion thickness of the adhesive to the metal powder prevents the formation of a complex porous structure, thus impacting heat exchange efficiency.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide an apparatus and method for preparing a porous heat transfer coating on the surface of a metal tube, so as to solve the problem that the thickness of the porous heat transfer coating is inconsistent in the prior art, which makes it impossible to form a porous structure with complex structure and affects the heat exchange efficiency.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] A porous heat transfer coating is prepared on the surface of a metal tube;

[0008] Includes: a guide rail; a material storage mechanism through which a metal tube passes; a film coating mechanism; a shaping wheel that contacts the film and extrudes the material; a light irradiation mechanism that irradiates the material; a laser device that melts the material onto the surface of the metal tube; a clamping rod that penetrates and supports the metal tube outwards; and a moving device that pulls the clamping rod to move.

[0009] The moving device is movably mounted on the guide rail; the film coating mechanism wraps the film around the shaping wheel; the material storage mechanism, the shaping wheel, and the laser device are sequentially arranged on the guide rail along the moving direction of the metal tube; the illumination mechanism is spaced between the material storage mechanism, the shaping wheel, and the laser device.

[0010] A further technical solution is that the material storage mechanism includes: a material storage cylinder, a covering cylinder connected to the material storage cylinder, and a scraper surrounding the metal tube; the metal tube passes through the covering cylinder; the scraper is located at the outlet of the covering cylinder and expands or contracts.

[0011] A further technical solution is that the coating mechanism includes: a feeding wheel, a receiving wheel, and a pressing wheel arranged opposite to each other; a first protrusion and a first concave portion are formed on the opposite pressing wheel; a second protrusion is formed on the receiving wheel; the two ends of the film are respectively wrapped around the feeding wheel and the receiving wheel; the film passes through the opposite pressing wheel and is then wrapped around the shaping wheel; the first protrusion is embedded in the first concave portion and hot-pressed to form the film; the second protrusion pushes the film outward to the forming position for tensioning.

[0012] A further technical solution is that the apparatus for preparing a porous heat transfer coating on the surface of a metal tube also includes:

[0013] An adjusting bracket and an air blowing device disposed on the adjusting bracket; the shaping wheels are relatively movably disposed on the adjusting bracket; a metal tube passes between the shaping wheels; the air blowing end of the air blowing device faces the film on the shaping wheel and is distributed along the moving direction of the film.

[0014] A further technical solution is that the clamping rod includes: a main rod passing through the metal tube, a guide rod slidably disposed on the main rod, and an outer support member hinged to the guide rod; when the guide rod moves along the main rod, the outer support member supports the metal tube outward; when the guide rod moves in the opposite direction along the main rod, the outer support member disengages from the metal tube.

[0015] A further technical solution is that the moving device includes a moving base plate, rollers rotatably mounted on the moving base plate, a moving plate movably mounted on the moving base plate, a lead screw rotatably mounted on the moving base plate, and grippers mounted on the moving plate; wherein, the rollers roll along the guide rail; the moving plate is threadedly connected to the lead screw; the rotation of the lead screw drives the moving plate to move along the moving base plate, and the moving plate drives the grippers to pull the clamping rod.

[0016] A method for preparing a porous heat transfer coating on the surface of a metal tube includes the following steps:

[0017] Clamping steps: The clamping rod passes through and supports the metal tube outward; the moving plate moves to the clamping rod, and the jaws pull one end of the clamping rod.

[0018] Moving steps: The base plate moves along the guide rail at a certain speed, and drives the metal tube to approach the discharge port of the storage mechanism, the shaping wheel, the illumination mechanism and the laser device in sequence;

[0019] Covering process: The material is mixed in the storage cylinder, the metal tube passes through the covering cylinder, and the material covers the outer surface of the metal tube; the scraper expands or contracts to control the thickness of the material coverage;

[0020] Forming steps: The film passes between the pressing rollers, and after being hot-pressed and formed, it is wound around the shaping rollers; the metal tube passes between the shaping rollers to complete the shaping of the material; the blowing device transfers heat to the film, causing the film to shrink; the blowing device blows the film away from the material, and the take-up roller collects the film;

[0021] Cladding steps: The light-irradiation mechanism irradiates the material to solidify it; the laser device acts on the material with a certain power.

[0022] A further technical solution is that the materials include: a binder, a first metal powder, and a second metal powder; the ratio of the first metal powder to the second metal powder is 7:3; the binder is 10-15 parts; and the first metal powder plus the second metal powder is 20-105 parts.

[0023] A further technical solution is that the melting temperature of the first metal powder is less than the temperature at which the laser device acts on the material; the melting temperature of the second metal powder is greater than the temperature at which the laser device acts on the material; the diameter of the second metal powder is greater than the diameter of the first metal powder; and the first metal powder comprises several metal particles with different diameters.

[0024] Compared with the prior art, the beneficial technical effects of the present invention are as follows: (1) The metal tube passes through the discharge port of the storage mechanism, and the material is covered on the outer surface of the metal tube; the film coating mechanism wraps the film around the shaping wheel, and when the shaping wheel squeezes the material, it avoids the material from sticking to the shaping wheel; after the material is laser clad, a porous layer is formed on the outer surface of the metal tube. The material is mixed with metal powder and binder, and the distribution of metal powder can be controlled, thereby controlling the path of the pores in the porous layer to improve the heat dissipation capacity of the porous layer on the metal tube; the material coverage thickness is controlled by the discharge port of the storage mechanism, the material coverage is ensured by rolling the material with the shaping wheel, and the material is clad by the laser device; in order to avoid the material from sticking to the shaping wheel, the film is wrapped around the shaping wheel, and the film is recycled after the shaping wheel completes the rolling of the material.

[0025] (2) The blowing device at the film entry position blows out cold air, which is used to cool and harden the film. The film is heated and formed when it passes through the pressing roller. The film needs to be cooled and then wound on the shaping roller. The blowing device at the position between the shaping rollers near the film exit direction blows out hot air, which heats the film. After the heated film leaves the shaping roller near the film exit direction, the heated film wrinkles. The blowing device at the film exit position blows out cold air, which cools and hardens the wrinkled film. Under the action of the cold air, the wrinkled film detaches from the material and is wound on the receiving roller for recycling.

[0026] (3) The metal tubes are pulled together by a pull rod. The moving device pulls a group of metal tubes for preparation, and the next group of metal tubes is moved by the pull rod, thereby realizing the rapid preparation of metal tubes. One end of the pull rod hooks the clamping rod inside a group of metal tubes, and the other end of the pull rod hooks the clamping rod inside the next group of metal tubes. The gripper can pull the metal tube by clamping the pull rod. When a group of metal tubes is prepared, the pull rod on the group of metal tubes and the group of metal tubes are removed, the moving device moves and resets, and the gripper clamps the pull rod on the next group of metal tubes again, thereby preparing the next group of metal tubes, thus realizing the continuous preparation of metal tubes and improving production efficiency.

[0027] (4) A hot medium flows inside the metal tube, while a cold medium flows outside. The cold medium flows into the channels, and the increased number of channels allows for a greater influx of cold medium, improving heat exchange efficiency. The heat from the hot medium is transferred to the cold medium within the channels, generating bubbles. As the bubble diameter gradually increases, it flows out along the channels. The longer channel length and uneven inner surface increase the surface area of ​​the channels, increasing the number of bubbles generated. The longer channel length also increases the time the bubbles spend flowing within the channels, increasing the heat absorbed by the bubbles and improving heat exchange efficiency. Furthermore, the uneven inner surface of the channels prevents the bubbles from flowing smoothly along the channels, further increasing the time they spend flowing within the channels and increasing the heat absorbed by the bubbles again, further improving heat exchange efficiency. Attached Figure Description

[0028] Figure 1 A schematic diagram of the apparatus for preparing a porous heat transfer coating on the surface of a metal tube according to an embodiment of the present invention is shown.

[0029] Figure 2 It shows Figure 1 Enlarged structural diagram at point A in the middle.

[0030] Figure 3 A schematic diagram of the scraper component according to an embodiment of the present invention is shown.

[0031] Figure 4 A schematic diagram of the coating mechanism and shaping wheel according to an embodiment of the present invention is shown.

[0032] The attached diagram is labeled as follows: 1. Guide rail; 2. Material storage mechanism; 21. Material storage cylinder; 22. Covering cylinder; 221. Outlet cylinder; 222. Cutting slit; 223. Cylinder cover; 23. Scraper; 24. Cylinder plate; 25. Electric push rod; 3. Film coating mechanism; 31. Feeding wheel; 32. Receiving wheel; 33. Pressing wheel; 34. First protrusion; 35. First concave part; 36. Second protrusion; 4. Shaping wheel; 41. Adjusting bracket; 42. Air blowing device; 5. Illumination mechanism; 6. Laser device; 7. Clamping rod; 71. Main rod; 711. Rod plate; 72. Guide rod; 73. External support; 74. Ring sleeve; 8. Moving device; 81. Moving base plate; 82. Roller; 83. Moving plate; 84. Lead screw; 85. Clamping claw. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the device proposed by this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of this invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, only for the purpose of conveniently and clearly illustrating the embodiments of this invention. Please refer to the accompanying drawings to make the objectives, features, and advantages of this invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and objectives achieved by this invention, should still fall within the scope of the technical content disclosed in this invention.

[0034] First embodiment:

[0035] Figure 1 A schematic diagram of the apparatus for preparing a porous heat transfer coating on the surface of a metal tube according to an embodiment of the present invention is shown. Figure 2 It shows Figure 1 Enlarged structural diagram at point A in the middle. Figure 3 A schematic diagram of the scraper component according to an embodiment of the present invention is shown. Figure 4 A schematic diagram of the coating mechanism and shaping wheel according to an embodiment of the present invention is shown. (In conjunction with...) Figures 1-4 As shown, this invention discloses an apparatus for preparing a porous heat transfer coating on the surface of a metal tube.

[0036] The apparatus for preparing a porous heat transfer coating on the surface of a metal tube includes: a moving device 8, a guide rail 1, a material storage mechanism 2, a coating mechanism 3, a shaping wheel that contacts the film and extrudes the material 4, a light irradiation mechanism that irradiates the material 5, a laser device that melts the material onto the surface of the metal tube 6, and a clamping rod that penetrates through and supports the metal tube outwards 7.

[0037] The guide rail 1 is arranged in a left-right direction. Along the direction of movement of the metal tube, a material storage mechanism 2, a shaping wheel 4, and a laser device 6 are arranged sequentially from left to right on the guide rail 1. For example, multiple light-illuminating mechanisms 5 are arranged. These mechanisms are spaced apart between the material storage mechanism 2, the shaping wheel 4, and the laser device 6. A moving device 8 is movably mounted on the guide rail 1. The moving device 8 is located at one end of the metal tube and clamps one end of a clamping rod 7. The moving device 8 drives the metal tube to move to the right along the guide rail 1.

[0038] The metal tube passes through the discharge port of the material storage mechanism 2, and the material is coated on the outer surface of the metal tube. The film coating mechanism 3 wraps the film around the shaping roller 4. When the shaping roller 4 extrudes and shapes the material, it prevents the material from sticking to the shaping roller 4.

[0039] After laser cladding, a porous layer is formed on the outer surface of the metal tube. The material is a mixture of metal powder and binder. The distribution of the metal powder can be controlled, thereby controlling the path of the pores in the porous layer to improve the heat dissipation capacity of the porous layer on the metal tube.

[0040] The material coverage thickness is controlled by the discharge port of the storage mechanism 2. The material is rolled by the shaping roller 4 to ensure uniform material coverage. The material is then clad by the laser device 6. To prevent the material from sticking to the shaping roller 4, the film is wound around the shaping roller 4. After the shaping roller 4 completes the rolling of the material, the film is then recycled.

[0041] The light-irradiation mechanism 5 is spaced between the material storage mechanism 2, the shaping wheel 4 and the laser device 6. The material does not solidify rapidly, but solidifies slowly before and after the shaping wheel 4 rolls, ensuring smooth film release.

[0042] The material storage mechanism 2 includes: a material storage cylinder 21, a covering cylinder 22 connected to the material storage cylinder 21, and a scraper 23 arranged around the metal tube. The metal tube passes through the covering cylinder 22. The scraper 23 is located at the outlet of the covering cylinder 22 and expands or contracts.

[0043] The lower end of the storage cylinder 21 is connected to the upper end of the covering cylinder 22. A cylinder plate 24 is slidably disposed inside the storage cylinder 21, and the cylinder plate 24 is in contact with the inner surface of the storage cylinder 21. An electric push rod 25 is disposed at the upper end of the storage cylinder 21. The cylinder plate 24 is connected to the drive end of the electric push rod 25. The storage cylinder 21 contains the mixed material. The electric push rod 25 pushes the cylinder plate 24 downward, and the cylinder plate 24 squeezes the material downward, so that the material enters the covering cylinder 22 from the storage cylinder 21.

[0044] The scraper 23 includes an outlet cylinder 221 located at the outlet of the covering cylinder 22, through which a metal tube passes. Cutouts 222 are formed at both ends of the outlet cylinder 221, and the cutouts 222 at both ends are staggered.

[0045] The scraper 23 also includes caps 223 at both ends of the outlet cylinder 221, which are threaded together. When the caps 223 are rotated, they move closer together and squeeze the outlet cylinder 221. The spacing of the cuts 222 is reduced, and the diameter of the outlet cylinder 221 decreases. When the metal tube passes through the outlet cylinder 221, the outlet cylinder 221 can accurately control the thickness of the material on the metal tube.

[0046] The coating mechanism 3 includes a feeding roller 31, a receiving roller 32, and a pressing roller 33 disposed opposite to each other. A first protrusion 34 and a first recess 35 are formed on the opposite pressing roller 33. A second protrusion 36 is formed on the receiving roller 32. The two ends of the film are respectively wound around the feeding roller 31 and the receiving roller 32.

[0047] A groove is formed around the shaping wheel 4, which is positioned opposite to the metal tube passing through the groove between them. If the film is directly wound onto the shaping wheel 4, wrinkles and stacking will form within the groove, affecting the surface quality of the material when the shaping wheel 4 compresses it. To ensure that the film shape fits the groove of the shaping wheel 4 when wound, the film needs to be shaped.

[0048] The pressing roller 33 is heated by an induction coil, and its temperature is measured by a sensor. The temperature of the pressing roller 33 is controlled by controlling the power of the induction coil. After the film passes through the pressing roller 33, it is wound around the shaping roller 4. The first protrusion 34 is embedded in the first concave portion 35 and the film is hot-pressed to form a shape. The formed film can fit into the groove of the shaping roller 4.

[0049] When recycling the film, the film is wrinkled. To ensure the uniformity of the stretching at each position of the film, the second protrusion 36 pushes the film forming position outward to tighten it, thus avoiding stretching of the film during the recycling process.

[0050] The apparatus for preparing a porous heat transfer coating on the surface of a metal tube also includes:

[0051] An adjusting bracket 41 and an air blowing device 42 mounted on the adjusting bracket 41 are included. The shaping wheels 4 are movably mounted on the adjusting bracket 41. By adjusting the position of the shaping wheels 4 on the adjusting bracket 41, the shaping wheels 4 can be moved closer to or further apart. When the shaping wheels 4 are closer together, the material thickness on the metal tube gradually decreases. When the shaping wheels 4 are further apart, the material thickness on the metal tube gradually increases.

[0052] The metal tube passes through the shaping rollers 4. There are multiple sets of shaping rollers 4 arranged opposite each other. The multiple sets of shaping rollers 4 repeatedly roll the material to strictly control the thickness of the material and ensure that the thickness distribution of the material is uniform.

[0053] There are multiple sets of air blowing devices 42. The air blowing devices 42 are located at the film insertion position, the position between the shaping rollers 4 near the film removal direction, and the film removal position. The air blowing end of the air blowing device 42 faces the film on the shaping rollers 4, and the air blowing devices 42 are distributed along the film movement direction.

[0054] The air blowing device 42, located at the film insertion position, blows out cold air, which is used to cool and harden the film. The film is heated and formed when it passes through the pressing roller 33, and the film needs to be cooled before being wound onto the shaping roller 4.

[0055] The air blowing device 42 located between the shaping rollers 4 and near the film removal direction blows out hot air. The hot air heats the film. After the heated film moves out of the shaping rollers 4 near the film removal direction, the heated film wrinkles. The air blowing device 42 at the film removal position blows out cold air. The cold air cools and hardens the wrinkled film. Under the action of the cold air, the wrinkled film detaches from the material and is wrapped around the receiving roller 32 for recycling.

[0056] The clamping rod 7 includes: a main rod 71 that passes through a metal tube in the left-right direction, a guide rod 72 that is slidably disposed on the main rod 71, and an outer support member 73 that is hinged to the guide rod 72.

[0057] For example, there are multiple sets of guide rods 72. The number of outer support members 73 corresponds to the number of guide rods 72. The guide rods 72 are arranged in a left-right direction and are distributed at intervals around the main rod 71. Adjacent guide rods 72 are interconnected. A rod groove is formed in the left-right direction on the outer surface of the main rod 71, and the guide rods 72 are placed in the rod groove and slide along the rod groove. The outer support members 73 are distributed around the inner surface of the metal tube.

[0058] A rod plate 711 is arranged side by side on the main rod 71, and the rod plate 711 is perpendicular to the main rod 71. When the guide rod 72 moves closer to the rod plate 711, the outer support member 73 contacts the rod plate 711. The guide rod 72 continues to move, pushing the outer support member 73 to swing outward along the rod plate 711. The outer support member 73 contacts the inner surface of the metal tube and forms outward support for the metal tube.

[0059] The main rod 71 is threaded with a ring 74. By rotating the ring 74, the position of the ring 74 on the main rod 71 is moved. The ring 74 restricts the outer support member 73 by abutting against the guide rod 72, so that the outer support member 73 can continuously support the metal tube outward.

[0060] When the guide rod 72 moves along the main rod 71, the outer support member 73 supports the metal tube outward. When the guide rod 72 moves in the opposite direction along the main rod 71, the outer support member 73 disengages from the metal tube.

[0061] The moving device 8 includes a moving base plate 81, rollers 82 rotatably mounted on the moving base plate 81, a moving plate 83 movably mounted on the moving base plate 81, a lead screw 84 rotatably mounted on the moving base plate 81, and grippers 85 mounted on the moving plate 83.

[0062] The movable base plate 81 is also equipped with a first motor and a second motor. The first motor drives the roller 82 to roll along the guide rail 1. The lower end of the movable plate 83 is threadedly connected to a lead screw 84, which is driven to rotate by the second motor.

[0063] For example, the gripper 85 is a pneumatic gripper. The second motor drives the lead screw 84 to rotate, causing the moving plate 83 to move along the moving base plate 81. The moving plate 83 drives the gripper 85 to clamp one end of the clamping rod 7. The first motor drives the roller 82 to roll along the guide rail 1, causing the moving device 8, the clamping rod 7 and the metal tube to move along the guide rail 1, so that the metal tube sequentially undergoes the following processes: the material storage mechanism 2 coats the surface of the metal tube with material, the light-irradiating mechanism 5 irradiates the solidified material, the shaping wheel 4 rolls and shapes the material on the metal tube, the light-irradiating mechanism 5 irradiates the solidified material and the laser device 6 melts the material onto the surface of the metal tube.

[0064] The metal tubes are moved together by a pull rod. The moving device 8 pulls one set of metal tubes for preparation, and the pull rod moves the next set of metal tubes, thus achieving rapid metal tube preparation. One end of the pull rod hooks onto the clamping rod 7 inside the first set of metal tubes, and the other end hooks onto the clamping rod 7 inside the next set of metal tubes. The gripper 85 pulls the metal tubes by holding the pull rod. After one set of metal tubes is prepared, the pull rod and the set of metal tubes are removed, the moving device 8 moves back to its original position, and the gripper 85 re-clamps the pull rod of the next set of metal tubes, thus preparing the next set of metal tubes. This achieves continuous metal tube preparation and improves production efficiency.

[0065] Second embodiment:

[0066] A method for preparing a porous heat transfer coating on the surface of a metal tube includes the following steps:

[0067] Clamping steps: Before covering the surface of the metal tube with material, first insert clamping rod 7 through and support the metal tube outward.

[0068] The main rod 71 passes through the metal tube in the left and right direction and pushes the guide rod 72 towards the rod plate 711. After the outer support 73 contacts the rod plate 711, the outer support 73 swings outward to support the metal tube under the action of the guide rod 72, and the rotating ring 74 holds the guide rod 72 in place.

[0069] The clamping rod 7 and the metal pipe are hoisted and moved close to the moving device 8. The first motor drives the roller 82 to roll along the guide rail 1, which in turn moves the moving base plate 81 closer to the metal pipe. The second motor drives the lead screw 84 to rotate, which in turn moves the moving plate 83. The moving plate 83 drives the gripper 85 to clamp the pull rod on the clamping rod 7.

[0070] Moving steps: The base plate 81 moves along the guide rail 1 at a certain speed, and drives the metal tube to approach the discharge port of the storage mechanism 2, the shaping wheel 4, the illumination mechanism 5 and the laser device 6 in sequence.

[0071] The first motor drives the roller 82 to roll along the guide rail 1, which in turn moves the movable base plate 81. The movable base plate 81 then drives the metal tube to go through the following processes in sequence: the material storage mechanism 2 coats the material on the surface of the metal tube; the light irradiation mechanism 5 irradiates the solidified material; the shaping wheel 4 rolls and shapes the material on the metal tube; the light irradiation mechanism 5 irradiates the solidified material; and the laser device 6 melts the material onto the surface of the metal tube.

[0072] Covering process: The material is mixed in the storage cylinder 21. The moving device 8 drives the metal tube to move through the covering cylinder 22, and the material covers the outer surface of the metal tube. The scraper 23 expands or contracts to control the thickness of the material coverage.

[0073] Tighten the caps 223 together, bring them closer together, and squeeze the outlet cylinder 221. The cut 222 is squeezed and contracted, the diameter of the outlet cylinder 221 decreases, and the thickness of the material decreases.

[0074] Loosen the caps 223 from each other, so that the caps 223 no longer compress the outlet cylinder 221, the slit 222 expands, the diameter of the outlet cylinder 221 increases, and the thickness of the material increases.

[0075] Forming steps: The film is fed onto the feeding roller 31, and the pressing roller 33 is heated by an induction coil. The film passes between the pressing rollers 33, and the first protrusion 34 and the first concave part 35 heat-press the film to form it. An air blowing device 42 located at the film's entry position blows cold air to cool and shape the film, which is then wrapped around the shaping roller 4. A metal tube passes between the shaping rollers 4, completing the material's shaping. Hot air blown by the air blowing device 42 near the film's exit direction between the shaping rollers 4 acts on the film, causing it to shrink and wrinkle. Cold air blown by the air blowing device 42 at the film's exit position cools and hardens the wrinkled film. Under the action of the cold air, the wrinkled film detaches from the material, and the air blowing device 42 blows the film away from the material. The receiving roller 32 collects the film.

[0076] Cladding Steps: The light-irradiation mechanism 5 irradiates the material to solidify it. The light-irradiation mechanism 5, positioned between the material storage mechanism 2 and the shaping wheel 4, initially solidifies the material. The light-irradiation mechanism 5, positioned between adjacent shaping wheels 4, gradually solidifies the material. The light-irradiation mechanism 5, positioned between the shaping wheel 4 and the laser device 6, completely solidifies the material.

[0077] The light-irradiation mechanism 5 is spaced between the material storage mechanism 2, the shaping wheel 4 and the laser device 6. The material does not solidify rapidly, but solidifies slowly before and after the shaping wheel 4 rolls, ensuring smooth film release.

[0078] The laser device 6 acts on the material with a certain power. The laser emitted by the laser device 6 melts and coats the material on the metal tube under the action of a protective gas. For example, the protective gas is an inert gas.

[0079] After the metal tube is clad, a set of metal tube upper pull rods and a set of metal tubes are removed, the moving device 8 moves and resets, and the gripper 85 re-grips the next set of metal tube upper pull rods.

[0080] The materials include: binder, first metal powder, and second metal powder. The ratio of first metal powder to second metal powder is 7:3. The binder is 10-15 parts, and the total amount of first metal powder + second metal powder is 20-105 parts. The first metal powder and second metal powder are mixed first, and then the binder is added and mixed.

[0081] The first metal powder melting temperature is less than the temperature at which the laser device 6 acts on the material. The second metal powder melting temperature is greater than the temperature at which the laser device 6 acts on the material.

[0082] The melting temperature of the second metal powder is higher than that of the first metal powder, meaning that when the first metal powder melts, the second metal powder does not. After the first metal powder melts, it fills the spaces between the second metal powders and adheres to them, forming porous channels in the porous heat transfer coating. Because the second metal powder does not melt, and the first metal powder melts and adheres to or fills the spaces between them, the porous heat transfer coating easily forms porous channels, increasing the number of channels.

[0083] The diameter of the second metal powder is greater than that of the first metal powder. The larger diameter of the second metal powder results in a longer outer perimeter, and the length of the channel formed when the first metal powder melts and adheres to the second metal powder is also longer.

[0084] The first metal powder comprises several metal particles of different diameters. The amount of these particles adhering to different locations in the second metal powder after melting varies, resulting in an uneven structure on the surface of the final channel. Larger diameter metal particles form raised structures on the inner surface of the channel, while smaller diameter metal particles form recessed structures.

[0085] A hot medium flows inside a metal tube, while a cold medium flows outside. The cold medium flows into the channels; the increased number of channels allows for a larger influx of cold medium, improving heat exchange efficiency. Heat from the hot medium is transferred to the cold medium within the channels, generating bubbles. As the bubble diameter gradually increases, it flows out along the channels. The long length of the channels and their uneven inner surfaces increase the surface area, thus increasing the number of bubbles. The longer channel length also increases the time the bubbles spend flowing within them, leading to increased heat absorption and further improved heat exchange efficiency. Furthermore, the uneven inner surfaces prevent the bubbles from flowing smoothly, further increasing their flow time and heat absorption, thus further enhancing heat exchange efficiency.

[0086] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0087] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An apparatus for preparing a porous heat transfer coating on the surface of a metal tube, characterized in that, include: Guide rail (1); Material storage mechanism (2), a metal tube passes through the discharge port of the material storage mechanism (2); Coating mechanism (3); The shaping wheel (4) contacts the film and squeezes the material; Illumination mechanism (5) irradiates the material; The laser device (6) melts the material onto the surface of the metal tube; The clamping rod (7) passes through and supports the metal tube outwards; The moving device (8) pulls the clamping rod (7) to move; The moving device (8) is movably mounted on the guide rail (1); the film coating mechanism (3) wraps the film around the shaping wheel (4); the material storage mechanism (2), the shaping wheel (4) and the laser device (6) are sequentially arranged on the guide rail (1) along the moving direction of the metal tube; the illumination mechanism (5) is spaced between the material storage mechanism (2), the shaping wheel (4) and the laser device (6). The material storage mechanism (2) includes: a material storage cylinder (21), a covering cylinder (22) connected to the material storage cylinder (21), and a scraper (23) arranged around the metal tube; the metal tube passes through the covering cylinder (22); the scraper (23) is arranged at the outlet of the covering cylinder (22) and expands or contracts; The apparatus for preparing a porous heat transfer coating on the surface of a metal tube also includes: Adjusting bracket (41) and air blowing device (42) disposed on the adjusting bracket (41); the shaping wheel (4) is relatively movably disposed on the adjusting bracket (41); the metal tube passes through the shaping wheel (4); the air blowing end of the air blowing device (42) faces the film on the shaping wheel (4) and is distributed along the moving direction of the film.

2. The apparatus for preparing a porous heat transfer coating on the surface of a metal tube as described in claim 1, characterized in that, The film coating mechanism (3) includes: a feeding wheel (31), a receiving wheel (32), and a pressing wheel (33) arranged opposite to each other; a first protrusion (34) and a first recess (35) are formed on the opposite pressing wheel (33); a second protrusion (36) is formed on the receiving wheel (32); the two ends of the film are respectively wrapped around the feeding wheel (31) and the receiving wheel (32); the film passes through the opposite pressing wheel (33) and is then wrapped around the shaping wheel (4); the first protrusion (34) is embedded in the first recess (35) to heat-press the film into shape; the second protrusion (36) pushes the film outward to the forming position to tighten it.

3. The apparatus for preparing a porous heat transfer coating on the surface of a metal tube as described in claim 1, characterized in that, The clamping rod (7) includes: a main rod (71) that passes through the metal tube, a guide rod (72) that is slidably disposed on the main rod (71), and an outer support member (73) that is hinged to the guide rod (72); when the guide rod (72) moves along the main rod (71), the outer support member (73) supports the metal tube outward; when the guide rod (72) moves in the opposite direction along the main rod (71), the outer support member (73) disengages from the metal tube.

4. The apparatus for preparing a porous heat transfer coating on the surface of a metal tube as described in claim 1, characterized in that, The moving device (8) includes a moving base plate (81), a roller (82) rotatably mounted on the moving base plate (81), a moving plate (83) movably mounted on the moving base plate (81), a lead screw (84) rotatably mounted on the moving base plate (81), and a gripper (85) mounted on the moving plate (83); wherein, the roller (82) rolls along the guide rail (1); the moving plate (83) is threadedly connected to the lead screw (84); the lead screw (84) rotates to drive the moving plate (83) to move along the moving base plate (81), and the moving plate (83) drives the gripper (85) to pull the clamping rod (7).

5. A method for preparing a porous heat transfer coating on the surface of a metal tube, using the apparatus for preparing a porous heat transfer coating on the surface of a metal tube as described in any one of claims 1-4, characterized in that, Includes the following steps: Clamping steps: The clamping rod (7) passes through and supports the metal tube outward; the moving plate (83) moves to the clamping rod (7), and the jaws (85) pull one end of the clamping rod (7); Moving steps: The base plate (81) moves along the guide rail (1) at a certain speed, and drives the metal tube to approach the discharge port, shaping wheel (4), illumination mechanism (5) and laser device (6) of the storage mechanism (2) in sequence. Covering step: The material is mixed in the storage cylinder (21), the metal tube passes through the covering cylinder (22), and the material covers the outer surface of the metal tube; the scraper (23) expands or contracts to control the thickness of the material covering; Forming steps: The film passes between the pressing rollers (33), and after being hot-pressed and formed, it is wrapped around the shaping roller (4); the metal tube passes between the shaping rollers (4) to complete the shaping of the material; the blowing device (42) transfers heat to the film, and the film shrinks; the blowing device (42) blows the film away from the material, and the receiving roller (32) collects the film. The cladding process involves: the light irradiation mechanism (5) irradiating the material to solidify it; and the laser device (6) applying a certain power to the material.

6. The method for preparing a porous heat transfer coating on the surface of a metal tube as described in claim 5, characterized in that, Materials include: Adhesive, first metal powder, and second metal powder; First metal powder: Second metal powder = 7:3; The adhesive is 10-15 parts; The first metal powder plus the second metal powder is 20-105 parts.

7. The method for preparing a porous heat transfer coating on the surface of a metal tube as described in claim 6, characterized in that, The melting temperature of the first metal powder is less than the temperature of the laser device (6) acting on the material; the melting temperature of the second metal powder is greater than the temperature of the laser device (6) acting on the material; the diameter of the second metal powder is greater than the diameter of the first metal powder; the first metal powder includes several metal particles with different diameters.

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