A porous tube for spheroidizing of powder coating and a system for preparing spheroidized powder coating

Abstract

The utility model relates to the field of powder coating preparation, especially a kind of porous pipe fitting for powder coating spheroidization and the system of preparation spheroidization powder coating.It has double-layer structure, including outer wall and inner wall, with cavity between the outer wall and inner wall;1 or more gas inlets that communicate the cavity are provided on the outer wall, and the gas inlet is respectively communicated with gas conveying mechanism, and the inner wall has porous structure, and the airflow from the gas inlet can pass through the cavity and enter the passageway of the powder coating along the porous structure of the inner wall;the feed end of the pipe fitting is communicated with the conveying mechanism of the powder coating;Heat exchange mechanism is provided on the pipe fitting.The porous pipe fitting can effectively prevent powder sticking wall and agglomeration phenomenon when processing spheroidization powder, improve production efficiency, and not only this, but also can benefit the uniform transmission of heat, benefit the rapid setting and collection of molten powder, and improve the spheroidization effect of powder coating.

Description

Technical Field

[0001] This utility model relates to the field of powder coating preparation, and in particular to a porous pipe for sphericalizing powder coatings and a system for preparing spherical powder coatings. Background Technology

[0002] Powder coatings are an environmentally friendly type of coating. Compared to solvent-based coatings, their zero-VOC production characteristics have enabled them to rapidly replace solvent-based coatings in large quantities under the trend of green chemistry. Due to their pure solid form, powder coatings have a material utilization rate of up to 99%, and they offer significant advantages over solvent-based coatings in terms of thick coating and mechanical properties, resulting in a promising market prospect. However, because conventional powder coating particles are mostly irregular in morphology, they suffer from defects such as unstable charge, poor flowability, poor compaction performance, and low particle layer packing density during electrostatic spraying.

[0003] Spheroidization technology is widely used in various particle processing methods. It involves melting irregular particles into spherical shapes at high temperatures. For example, spheroidizing lithium-ion battery cathode materials in new energy batteries increases compaction density, effectively improving energy density. In metal 3D printing, spheroidization increases the compaction density and flowability of the printing material, effectively enhancing the strength of the printed parts. Similar spheroidization technologies have emerged in powder coatings, effectively improving their flowability, coating density, powder storage performance, and coating corrosion resistance. In summary, spheroidized powder coatings possess numerous advantages and have broad application prospects in industrial production.

[0004] In the spheroidization process of powder coatings, powder particles often adhere to each other or to the coating wall after heating. Compared to the spheroidization of metals and ceramics, powder coatings, due to their lighter weight and higher viscosity after melting, are particularly prone to adhesion and clumping within the spheroidization equipment's pipes. This problem not only affects the spheroidization effect but also leads to low equipment production efficiency, powder waste, and unstable product quality. During mass production, repeated adhesion can reduce the pipe's inner diameter, ultimately causing equipment blockage. Current technologies use airflow to transport powder through heating pipes, but the adhesion of powder particles to the heating pipe surface is not considered, resulting in reduced equipment lifespan and powder waste.

[0005] Traditional heating pipe designs, when processing spherical powders, often fail to effectively prevent powder from sticking to the pipe walls due to their smooth surfaces or lack of anti-sticking measures. This not only leads to powder loss and uneven heat transfer, affecting equipment production efficiency, but also hinders the rapid shaping and collection of molten powder, all of which negatively impact the final spheroidization effect. Therefore, how to avoid powder sticking and improve the spheroidization effect is an urgent problem to be solved. Summary of the Invention

[0006] To address the technical problems existing in the prior art, this utility model provides a porous pipe fitting for spheroidizing powder coatings and a system for preparing spheroidized powder coatings. This porous pipe fitting effectively prevents powder from sticking to the walls and clumping during the processing of spheroidized powder, improving production efficiency. Furthermore, it facilitates uniform heat transfer, rapid shaping and collection of molten powder, and enhances the spheroidization effect of the powder coating.

[0007] The first aspect of this utility model is to provide a pipe fitting for sphericalizing powder coatings. The pipe fitting has a double-layer structure, including an outer wall and an inner wall, with a cavity between the outer wall and the inner wall. The pipe surrounding the inner wall serves as a passage for the powder coating. The outer wall is provided with one or more air inlets communicating with the cavity, each air inlet communicating with a gas delivery mechanism. The inner wall has a porous structure, allowing airflow from the air inlets to pass through the cavity and along the porous structure of the inner wall into the passage for the powder coating. The feed end of the pipe fitting is connected to the powder coating conveying mechanism; The pipe fitting is equipped with a heat exchange mechanism for heating or cooling the airflow and / or powder coating inside the pipe.

[0008] According to this utility model, preferably, both ends of the cavity are sealed by plates.

[0009] According to this utility model, preferably, the number of air inlets on the outer wall is 2-8; and / or, the air inlets are evenly distributed (e.g., evenly spirally distributed) along the axial and circumferential directions of the pipe; and / or, each air inlet is connected to a gas conveying mechanism, and as an example, preferably, each air inlet is connected to a compressed gas conveying mechanism.

[0010] According to this utility model, preferably, the width of the cavity between the outer wall and the inner wall is 10-50mm; preferably, the outer diameter of the pipe is 50-125mm and the inner diameter is 40-100mm.

[0011] According to this invention, the length of the pipe fitting can be adjusted according to the heating or cooling process.

[0012] According to this utility model, preferably, the pore size distributed on the inner wall is between 10 and 500 μm, and / or the average porosity of the inner wall is above 35%.

[0013] According to this utility model, preferably, the heat exchange mechanism is disposed on the outside of the pipe fitting or in part of the cavity.

[0014] According to this utility model, preferably, the heat exchange mechanism is selected from one or more combinations of electromagnetic heat exchange mechanism, resistance heating mechanism, water cooling mechanism, oil bath mechanism, air cooling mechanism, and gas heating mechanism.

[0015] According to this utility model, preferably, the heat exchange mechanism includes a heating mechanism and a cooling mechanism, wherein the heating mechanism and the cooling mechanism are arranged sequentially along the feeding direction of the powder coating.

[0016] According to this utility model, preferably, the outer wall and inner wall of the pipe fitting are each in one or more combinations of cylindrical or square shapes; and / or, the pipe fitting is made of metal.

[0017] A second aspect of this invention is to provide a system for preparing spherical powder coatings, comprising: The feeding device, the pipe fittings for sphericalizing powder coating, and the collecting device are connected sequentially in the feeding direction; Wherein, the pipe fitting for spheroidizing powder coating is the pipe fitting for spheroidizing powder coating described in the first aspect; It also includes a gas delivery mechanism, which is connected to the air inlet of the spherical tube of the powder coating.

[0018] According to this utility model, preferably, the feeding device is selected from one or more combinations of fluidized bed, venturi feeding device, and aerosol generator.

[0019] According to this utility model, preferably, the collecting device is selected from one or more combinations of filter bags, electrostatic collectors, and cyclone separators.

[0020] Compared with the prior art, the advantages of this utility model are: This porous tube fitting for sphericalizing powder coatings can effectively prevent powder from sticking to the wall and clumping when processing spherical powder. In addition, it can also facilitate the uniform transfer of heat, facilitate the rapid shaping and collection of molten powder, and improve the spherical effect of powder coatings.

[0021] More specifically, the beneficial effects of adopting this technical solution include: 1. Preventing Powder Adhesion to the Pipe Wall: The porous pipe design effectively prevents powder particles from contacting the pipe wall, thereby reducing powder coating loss and improving production efficiency. Powder particles can quickly pass through the heating pipe under the action of airflow, reducing the possibility of powder adhering to the pipe wall and avoiding equipment wear and maintenance costs caused by adhesion.

[0022] 2. Improved thermal efficiency: The porous structure increases the contact area between the powder and hot air, allowing heat to be transferred more evenly to the powder particles, thereby improving the thermal efficiency of the spheroidization process. Through uniform heating, the powder particles can transform into a spherical shape more quickly, thus improving production efficiency and saving energy.

[0023] 3. Improved Spheroidization Effect: By rationally controlling the airflow, heating / cooling methods, and the porous structure, powder particles can be uniformly heated within the heating tube, ensuring their transformation from irregular shapes to spherical particles. These particles then rapidly solidify in the cooling tube, improving spheroidization efficiency and quality. Spherical powder particles exhibit better flowability and bulk density, effectively enhancing the forming quality and processing performance of powder coatings.

[0024] 4. Reduced Powder Waste: The porous structure of the tubing effectively reduces powder coating waste, improving the overall efficiency of the equipment. Powder coating loss is minimal when passing through the heating tubes, thus enhancing the sustainability and economic benefits of the production process. Attached Figure Description

[0025] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein: Figure 1 This is a schematic diagram of one embodiment of the pipe fitting for sphericalization of powder coating according to this utility model; Figure 2 This is a schematic diagram of one embodiment of the pipe fitting for sphericalization of powder coating according to this utility model; Figure 3 This is a schematic diagram of one embodiment of the pipe fitting for sphericalization of powder coating according to this utility model; Figure 4 This is a schematic diagram of the system structure for preparing spherical powder coatings according to this utility model; In the figure, 1. the outer wall of the pipe used for spheroidizing powder coating, 2. the inner wall of the pipe used for spheroidizing powder coating, 3. the gas conveying mechanism, 4. the air inlet, 5. the heat exchange mechanism, 6. the feeding device, and 7. the collecting device. Detailed Implementation

[0026] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings. It should be noted that the following embodiments and accompanying drawings are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0027] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings.

[0028] like Figures 1-3 As shown, the first aspect of this utility model is to provide a pipe fitting for sphericalizing powder coatings. The pipe fitting has a double-layer structure, including an outer wall 1 and an inner wall 2, with a cavity between the outer wall 1 and the inner wall 2. The pipe surrounding the inner wall 2 serves as a passage for the powder coating. The outer wall 1 is provided with one or more air inlets 4 communicating with the cavity, each of the air inlets 4 being connected to a gas conveying mechanism 3. The inner wall 2 has a porous structure, allowing airflow from the air inlets 4 to pass through the cavity and enter the passage for the powder coating along the porous structure of the inner wall 2. The feed end of the pipe fitting is connected to the powder coating conveying mechanism. The pipe fitting is provided with a heat exchange mechanism 5 for heating or cooling the airflow and / or powder coating within the pipe. In use, the spherical powder coating enters the inner wall 2 of the pipe surrounding the spherical tube through the feed end of the tube used for powder coating spherification. At this time, the gas conveying mechanism 3 delivers airflow through the air inlet 4 into the cavity between the outer wall 1 and the inner wall 2. The airflow from the air inlet 4 passes through the cavity and enters the powder coating passage along the porous structure of the inner wall 2. Under the gas flow, an air wall is formed on the inner wall 2 of the tube on the passage side of the powder coating, which can prevent powder particles from contacting the tube wall, thus avoiding wall adhesion. This invention can efficiently process spherical powder coatings. Compressed gas enters the cavity through the air inlet 4 and permeates the porous structure of the inner wall of the tube. After being heated (cooled) by the porous tube, the compressed gas fully contacts the powder inside the tube, achieving sphericalization of the powder coating. This invention can prevent powder from sticking to the wall and clumping, and effectively improves the production efficiency of powder coating sphericalization.

[0029] To further analyze the technical effects of this utility model, and in conjunction with its specific structural design, the following analysis is provided: 1. The pipe fitting has a porous structure: This porous structure allows the powder particles to fully contact the airflow inside the pipe, while avoiding the adhesion of powder particles due to contact with the pipe wall.

[0030] 2. Unidirectional Airflow System: Compressed gas is introduced through the air inlet, creating a unidirectional airflow within the pipe (the passageway for powder coating). This ensures the airflow follows the pipe's direction, further preventing powder particles from flowing back and contacting the pipe wall. The unidirectional airflow design not only helps prevent powder from sticking to the wall but also increases the contact area between the powder and air, thus improving the spheroidizing effect. Precise temperature control of the spheroidizing process is achieved by controlling the temperature of the unidirectional airflow.

[0031] 3. The pipe fitting is equipped with a heat exchange mechanism 5 for heating or cooling the powder coating inside the pipe. The heat exchange mechanism 5 is a heating / cooling device. The heating device preferably uses electromagnetic induction heating, resistance heating, or other heating methods to transfer heat to the powder particles through the pipe fitting, causing them to melt and spherize during the heating process. Electromagnetic induction heating can heat the heating tube to the required temperature in a short time, effectively improving the efficiency of the spheroidizing process. Through rapid heating, the powder particles can quickly melt and begin to spherize, avoiding heat loss and uneven heating. The cooling device works similarly to the heating device. By reducing the airflow temperature through water / air-cooled copper pipes, the molten spheroidized powder can be cooled and shaped, preventing agglomeration between powder particles or between powder and the wall, effectively improving the product quality of the spheroidized powder. Preferably, the heat exchange mechanism is located on the outside of the pipe fitting or in part of the cavity.

[0032] According to this utility model, preferably, both ends of the cavity are sealed by plates.

[0033] According to this utility model, preferably, the number of air inlets 4 on the outer wall 1 is 2-8; and / or, the air inlets 4 are evenly distributed along the axial and circumferential directions of the pipe; and / or, each air inlet 4 is connected to a gas delivery mechanism 3. For example, preferably, each air inlet 4 is connected to a compressed gas delivery mechanism 3. For example, an air compressor is responsible for providing unidirectional airflow. Further, the heat exchange mechanism 5 achieves precise temperature control by heating / cooling the unidirectional airflow, thereby realizing the spheroidization and cooling of the powder.

[0034] According to this utility model, preferably, the width of the cavity between the outer wall and the inner wall is 10-50mm; preferably, the outer diameter of the pipe is 50-125mm and the inner diameter is 40-100mm.

[0035] According to this invention, preferably, the pore size distributed on the inner wall 2 is between 10 and 500 μm, and / or the average porosity of the inner wall is above 35%. This further facilitates the formation of the air wall, further helps prevent wall adhesion, and also further facilitates the uniform distribution of heat, thereby further improving the sphericity effect.

[0036] According to this utility model, preferably, the heat exchange mechanism 5 is disposed on the outside of the pipe fitting or in part of the cavity.

[0037] According to this utility model, preferably, the heat exchange mechanism 5 is selected from one or more combinations of electromagnetic heat exchange mechanism 5, resistance heating mechanism, water cooling mechanism, oil bath mechanism, air cooling mechanism, and gas heating mechanism.

[0038] Preferably, the pipe fitting is made of metal and can be electromagnetically heated.

[0039] According to this utility model, preferably, the heat exchange mechanism 5 includes a heating mechanism and a cooling mechanism, wherein the heating mechanism and the cooling mechanism are arranged sequentially along the feeding direction of the powder coating. The coating is first spherically shaped by heating, and then cooled to set its shape.

[0040] According to this utility model, preferably, the outer wall 1 and inner wall 2 of the pipe fitting are each in one or more combinations of cylindrical or square shapes; and / or, the material of the pipe fitting is metal.

[0041] like Figure 4 As shown, the system for preparing spherical powder coatings of this invention includes: The feeding device 6, the pipe for spheroidizing powder coating, and the collecting device 7 located below the feeding device 6 are connected in sequence according to the feeding direction; wherein, the pipe for spheroidizing powder coating is the pipe for spheroidizing powder coating described in the first aspect; it also includes a gas conveying mechanism 3, which is connected to the air inlet 4 of the pipe for spheroidizing powder coating.

[0042] The system of this utility model allows for the sphericalization of powder coatings using a porous tube fitting. This fitting can be configured with a heating mechanism and a cooling mechanism in sequence, combined with feeding from the feeding device 6, to directly sphericalize and cool the powder coating, and collect the powder in the collecting device 7.

[0043] According to this utility model, preferably, the feeding device 6 is selected from one or more combinations of fluidized bed, Venturi feed device 6, and aerosol generator.

[0044] According to this utility model, preferably, the collecting device is selected from one or more combinations of filter bags, electrostatic collectors, and cyclone separators.

[0045] The following examples further illustrate the usage and effects of this utility model.

[0046] Example 1 like Figure 1 As shown, a porous pipe fitting for spheroidizing powder coatings employs a porous structure. The fitting has an outer diameter of 50 mm and an inner diameter of 40 mm. The pores distributed on the inner wall of the fitting have a diameter of 50 μm, and the overall porosity of the inner wall is above 35%. There are four air inlets on the outer wall, with an air intake rate controlled at 6 m³ / h. A heating device is located on the outer side of the fitting's outer wall, heating the inside of the pipe to a maximum of 500°C via electromagnetic heating. The powder coating (particle size 20-45 μm) is conveyed into the pipe via airflow (i.e., the pipe surrounding the inner wall serves as the passageway for the powder coating), and comes into full contact with the hot airflow, rapidly melting and transforming into spherical particles.

[0047] Example 2 like Figure 2 As shown, a porous pipe fitting combined with a gas delivery mechanism is used to shape the powder coating through a cooling pipe. The pipe fitting has an outer diameter of 75mm, an inner wall side length of 50mm, and pores with a diameter of 50μm distributed on its inner wall; the inner wall porosity is 40%. There are 8 air inlets on the outer wall, with an air intake rate controlled at 8m³ / h. A copper pipe water-cooling system located on the outer wall of the pipe fitting cools the unidirectional airflow to 10℃, ensuring sufficient contact between the powder particles and the cold air for rapid cooling and shaping. The pipe fitting is square, and the four right-angled areas create a shielding effect, which, together with the unidirectional airflow, ensures that the powder does not contact the wall surface, concentrating in the central area of ​​the pipe and achieving spherical shaping.

[0048] Example 3 like Figure 3 As shown, in this embodiment, porous pipe fittings made of 310S stainless steel (a material with higher temperature resistance) are used. The pipe fitting has an outer diameter of 125mm and an inner diameter of 90mm, with pores of 30μm distributed on its inner wall; the inner wall porosity is 35%, and there are 8 air inlets on the outer wall, with an air intake controlled at 4m³ / h. An internal electromagnetic heating method is employed, which can directly raise the pipe temperature to 600℃. Powder coating is fed into the heating tube via a Venturi device, ensuring full contact between the airflow and the powder particles and heating them to a molten state, ultimately achieving spherical shaping. This embodiment offers a higher heating temperature and is suitable for high-temperature applications such as fluorocarbon coatings. g Powder coatings with specific formulations.

[0049] In summary, the porous tube fitting used for sphericalization of powder coatings can effectively prevent powder from sticking to the wall and clumping when processing spherical powder, thus improving production efficiency. Moreover, it can facilitate uniform heat transfer, rapid shaping and collection of molten powder, and improve the sphericalization effect of powder coatings. Furthermore, this utility model has a wide range of applications and high application value.

[0050] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present utility model, and these all fall within the protection scope of the present utility model.

[0051] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

[0052] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0053] When this specification uses the prefixes “known to those skilled in the art,” “prior art,” or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0054] The endpoints and any values ​​of the ranges disclosed in this application are not limited to the precise ranges or values; such ranges or values ​​should be understood to include values ​​close to them. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. In principle, various technical solutions can be combined with each other to obtain new technical solutions, which should also be considered as specifically disclosed herein.

[0055] In the context of this specification, except where expressly stated otherwise, any matters or issues not mentioned shall apply directly to those known in the art without any modification.

[0056] Furthermore, any implementation described herein can be freely combined with one or more other implementations described herein, and the resulting technical solutions or technical ideas shall be regarded as part of the original disclosure or original record of this utility model, and should not be regarded as new content not disclosed or anticipated herein, unless those skilled in the art believe that the combination is obviously unreasonable.

Claims

1. A porous tube for spheroidizing powder coatings, the porous tube having a double-layer structure including an outer wall and an inner wall, characterized in that, A cavity exists between the outer wall and the inner wall, and the pipe surrounding the inner wall serves as a passage for the powder coating. One or more air inlets are provided on the outer wall, which communicate with the cavity. Each air inlet is connected to a gas delivery mechanism. The inner wall has a porous structure, allowing airflow from the air inlets to pass through the cavity and enter the passage for the powder coating along the porous structure of the inner wall. The feed end of the porous tube is connected to the powder coating conveying mechanism; The porous pipe fitting is equipped with a heat exchange mechanism for heating or cooling the powder coating inside the pipe.

2. The porous pipe fitting according to claim 1, characterized in that: The two ends of the cavity are sealed by plates.

3. The porous pipe fitting according to claim 1, characterized in that: The number of air inlets on the outer wall is 2-8; and / or, The air inlets are evenly distributed along the axial and circumferential directions of the porous pipe.

4. The porous pipe fitting according to claim 1, characterized in that: The pores distributed on the inner wall have a diameter of 10 to 500 μm, and / or the average porosity of the inner wall is above 35%.

5. The porous pipe fitting according to claim 1, characterized in that: The heat exchange mechanism is located on the outside of the porous pipe or in part of the cavity.

6. The porous pipe fitting according to claim 1, characterized in that: The heat exchange mechanism is selected from one or more combinations of electromagnetic heat exchange mechanisms, resistance heating mechanisms, water cooling mechanisms, oil bath mechanisms, air cooling mechanisms, and gas heating mechanisms.

7. The porous pipe fitting according to claim 1, characterized in that: The heat exchange mechanism includes a heating mechanism and a cooling mechanism, wherein the heating mechanism and the cooling mechanism are arranged sequentially along the feeding direction of the powder coating.

8. The porous pipe fitting according to claim 1, characterized in that: The outer and inner walls of the porous pipe fitting are each in one or more combinations of cylindrical or square shapes; and / or, The porous pipe fitting is made of metal.

9. A system for preparing spherical powder coatings, comprising: The feeding device, the porous pipe fitting for sphericalizing powder coating, and the collecting device are connected sequentially in the feeding direction; The porous tube for spheroidizing powder coating is, as described in any one of claims 1-8, the porous tube for spheroidizing powder coating; It also includes a gas delivery mechanism, which is connected to the air inlet of the porous tube with spherical powder coating.

10. The system according to claim 9, characterized in that: The feeding device is selected from one or more combinations of fluidized bed, Venturi feeder, and aerosol generator; and / or The collection device is selected from one or more combinations of filter bags, electrostatic collectors, and cyclone separators.

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