Powder fluidization box based on double independent fluidization units and fluidization method
By using a powder fluidization box with dual independent fluidization units and a fluidization method, the problem of color difference in spraying caused by the density difference of metal powder was solved, thereby improving powder uniformity and production efficiency, and reducing costs and manual intervention.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-19
- Publication Date
- 2026-04-14
AI Technical Summary
In existing powder fluidization boxes, the metal powder and resin components tend to accumulate in the cavity due to density differences, resulting in color differences on the surface of the profile during spraying, and frequent manual powder replenishment increases the complexity of the process.
The powder fluidization box adopts dual independent fluidization units, with separate fluidization boxes for recycled powder and new powder. It achieves precise powder supply through independent powder pumps and grouped spray guns, independently controls gas flow rate and fluidization parameters, and uses new powder to correct color differences.
It improves powder uniformity, reduces the rate of color difference defects in spraying, reduces manual intervention, increases production efficiency and the utilization rate of new powder, and reduces raw material costs.
Smart Images
Figure CN121852894A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of powder fluidization box technology, specifically to a powder fluidization box and fluidization method based on dual independent fluidization units. Background Technology
[0002] In vertical electrostatic powder coating of metal powder, the metal powder needs to be uniformly fluidized in a fluidization box to meet the core requirement of precise powder supply to the spray gun. A typical process flow is as follows: metal powder is pumped to the spray gun for coating; uncoated "recycled powder" is purified by cyclone separation and returned to the fluidization box to mix with new powder for repeated fluidization and recycling. The key to this process is maintaining powder uniformity to avoid color differences caused by uneven distribution of metallic pigments.
[0003] In existing technologies, to achieve powder recycling, a common approach is the "single large fluidizing box + manual powder replenishment" model: recycled powder and new powder are directly mixed and fluidized in the same box, relying on operators to periodically monitor and replenish new powder to mitigate color differences. This single-chamber structure allows for direct mixing and fluidization of recycled and new powder, with all spray guns drawing powder from this single chamber. While this process alleviates color differences through powder replenishment, it fails to address the core issue of secondary metal agglomeration after the recycled and new powder mixture. The metal powder portion and resin portion added to the metal powder separate from the resin matrix due to density differences, easily accumulating within the chamber to form localized enriched or depleted areas, leading to color differences on the profile surface during subsequent spraying. Even with a "small-volume semi-continuous powder replenishment" process, secondary agglomeration after mixing cannot be avoided, and frequent manual powder replenishment increases the complexity of the process. Therefore, we provide a powder fluidizing box and fluidization method based on dual independent fluidizing units. Summary of the Invention
[0004] The purpose of this invention is to provide a powder fluidization box and fluidization method based on dual independent fluidization units, in order to solve the problem mentioned in the background art that the metal powder and resin portions added to the metal powder in the existing powder fluidization box separate from the resin matrix due to density differences, and are prone to accumulating in the cavity to form local enrichment or depletion areas, resulting in color difference on the profile surface during subsequent spraying.
[0005] To achieve the above objectives, the present invention provides the following technical solution: a powder fluidization box based on dual independent fluidization units, comprising two gas inlet chambers arranged side by side; Also includes: The recycled powder fluidizing box and the new powder fluidizing box are welded and installed at the upper end of the two gas inlet chambers respectively, and the rear end of the recycled powder fluidizing box and the new powder fluidizing box is provided with a mounting base. Two powder pipe fixing brackets are provided above the recycled powder fluidizing box and the new powder fluidizing box. The four powder pipe fixing brackets and the mounting base are integrated into one structure. A spoiler is disposed inside the gas inlet chamber, with equal spacing between two adjacent spoilers; The powder extraction pipe is installed on the powder pipe fixing frame, and six powder extraction pipes are installed on each of the four powder pipe fixing frames. The spacing between two adjacent powder extraction pipes is equal, and the powder extraction pipe is connected to the spray gun.
[0006] Preferably, a powder tube back-blowing device is provided below the powder extraction tube. There are four powder tube back-blowing devices, and each of the four powder tube back-blowing devices has six back-blowing nozzles at its upper end. The six back-blowing nozzles correspond one-to-one with the six powder extraction tubes on the powder tube fixing frame.
[0007] Preferably, each of the two gas inlet chambers is provided with a fluidized compressed air inlet on its front end face, and the fluidized compressed air inlet is connected to the interior of the gas inlet chamber.
[0008] Preferably, a tube bundle plate is provided below the powder tube fixing frame, and the tube bundle plate is fixedly connected to six powder extraction tubes.
[0009] Preferably, the two gas inlet chambers are equipped with dense void partitions, through which compressed air is uniformly fluidized upwards to recover the powder in the fluidized bed and the new powder fluidized bed.
[0010] Preferably, the fluidized bed for recovering powder only receives metal powder recovered by cyclone separation, and the fluidized bed for new powder is continuously replenished with new metal powder.
[0011] Preferably, the recycled powder fluidizing box and the new powder fluidizing box are respectively connected to an independent powder pump and six spray guns on four powder pipe fixing brackets, and the two sets of spray guns are respectively connected to the independent powder pumps of the recycled powder fluidizing box and the new powder fluidizing box.
[0012] Preferably, the fluidization method for a powder fluidization box based on dual independent fluidization units includes the following steps: Step 1: Connect the front row of spray guns to the fluidized bed of recycled powder and the rear row of spray guns to the fluidized bed of new powder. Divide the multiple spray guns arranged in parallel into front row and rear row spray gun groups according to their front and rear positions. There are 24 spray guns in total, divided into 12 in the front and 12 in the back, and each is matched with two independent powder pumps. Step 2: The recycled powder pump is connected to the bottom of the recycled powder fluidization tank through a pipeline, and draws the fluidized recycled powder to the front spray gun group. The new powder pump is connected to the bottom of the new powder fluidization tank, and draws the uniform new powder to the rear spray gun group. Step 3: The front row of spray guns takes powder from the recycled powder fluidization box and is mainly responsible for basic spraying; the rear row of spray guns takes powder from the new powder fluidization box and uses the uniform new powder to cover up and correct any color differences that may exist in the front row, ultimately ensuring that the overall color of the profile surface is consistent. Step 4: The two sets of spray guns independently control the spraying parameters and adjust them precisely according to the profile position to achieve differentiated powder supply.
[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention solves the process problem of uneven metal distribution: by using dual independent fluidizing boxes for zoned fluidization with clear division of labor, the front zone centrally processes the recovered powder (allowing local metal agglomeration), while the rear zone uses fresh powder to ensure uniformity, thus avoiding secondary agglomeration caused by overall mixing from the source of the process.
[0014] 2. Independent control ensures greater precision and improves process reliability for color consistency: Two fluidization chambers independently adjust gas flow rate, powder quantity, and fluidization parameters, allowing for targeted optimization of the fluidization state of recycled powder (allowing slight agglomeration) and fresh powder (pursuing absolute uniformity), improving powder uniformity by 80%. While the front spray guns may pose a risk of localized color differences due to the use of powder from the front zone, the rear spray guns simultaneously apply uniform fresh powder, correcting for color differences in the front zone through spatial superposition effect, resulting in a consistent color on the final profile surface.
[0015] 3. The fluidized bed can operate stably with the addition of new powder, eliminating the need for frequent manual powder replenishment. This also improves the utilization rate of new powder and reduces the color difference defect rate by 90%. The economic benefits are significant: In terms of tangible value, taking a single production line as an example, before the upgrade, an average of 5 instances of color difference occurred per batch per week, requiring measures such as powder removal, color retesting, and (demolding) rework. The cost per instance is calculated at 1000 yuan. Based on an annual production period of 11 months, the annual cost savings are: 5 times / week × 4 weeks / month × 11 months / year × 1000 yuan / time = 235,000 yuan. Simultaneously, the overall powder utilization rate increases by approximately 20%, further reducing raw material costs. In terms of intangible value, reducing the frequency of color difference rework improves the first-pass yield and on-time order delivery rate, enhancing customer satisfaction and the company's market reputation.
[0016] 4. Strong process compatibility: The dual fluidization box can be maintained or replaced independently, and the modification difficulty is low. It is suitable for the process upgrade of existing spraying equipment and shortens the production line modification cycle. Attached Figure Description
[0017] Figure 1 This is a front view of the powder fluidization box structure based on dual independent fluidization units of the present invention; Figure 2 This is a top view of the powder fluidization box structure based on dual independent fluidization units of the present invention; Figure 3 This is a rear view of the powder fluidization box structure based on dual independent fluidization units according to the present invention. Figure 4 This is a bottom view of the powder fluidization box structure based on dual independent fluidization units according to the present invention; In the diagram: 1. Fluidized bed for recovering powder; 2. Fluidized bed for new powder; 3. Mounting base; 4. Powder pipe fixing bracket; 5. Powder extraction pipe; 6. Gas inlet chamber; 7. Fluidized compressed air inlet; 8. Bundle plate; 9. Baffle plate; 10. Powder pipe backflushing device; 11. Backflushing nozzle. Detailed Implementation
[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.
[0019] Please see Figure 1-4 The present invention provides an embodiment of a powder fluidization box based on dual independent fluidization units, including a gas inlet chamber 6, wherein there are two gas inlet chambers 6 arranged side by side; Also includes: The recycled powder fluidizing box 1 and the new powder fluidizing box 2 are respectively welded to the upper end of the two gas inlet chambers 6, and the rear end of the recycled powder fluidizing box 1 and the new powder fluidizing box 2 are provided with mounting bases 3. Two powder pipe fixing brackets 4 are provided above the recycled powder fluidizing box 1 and the new powder fluidizing box 2. The four powder pipe fixing brackets 4 and the mounting bases 3 are integrated into one structure. A spoiler 9 is installed inside the gas inlet chamber 6, and the spacing between two adjacent spoilers 9 is equal. The powder extraction pipe 5 is installed on the powder pipe fixing bracket 4, and there are six powder extraction pipes 5 on each of the four powder pipe fixing brackets 4. The spacing between two adjacent powder extraction pipes 5 is equal, and the powder extraction pipe 5 is connected to the spray gun.
[0020] Recycled Powder Fluidization Box 1: Only receives metal powder recovered by the cyclone separation system. It is uniformly fluidized through the bottom gas inlet chamber to maintain its loose state, focusing on the recycling of recycled powder. Fresh Powder Fluidization Box 2: Continuously replenishes fresh metal powder. It is uniformly fluidized through the bottom gas inlet chamber to ensure that the fresh powder is evenly dispersed and does not agglomerate. A "dual independent fluidization unit" structure is proposed. Two small fluidization boxes are used to process recycled powder and fresh powder respectively, realizing the physical isolation and independent fluidization of the two types of powder, avoiding uniformity problems caused by mixing. It is equipped with an "independent powder pump + grouped spray gun" powder supply logic. The front row of spray guns uses the powder from the front zone, and the rear row of spray guns uses the powder from the rear zone, realizing the precise and independent supply of recycled powder and fresh powder. The color difference of the front row is corrected by the spraying of fresh powder to ensure the overall color consistency and reduce the reliance on manual intervention. A "bottom gas supply chamber + dense void partition" fluidization system is designed to independently control the fluidization process and ensure the uniformity of powder in both boxes.
[0021] Please see Figure 2Below the powder extraction pipe 5, there are four powder pipe back-blowing devices 10. Each of the four back-blowing devices 10 has six back-blowing nozzles 11 at its upper end. Each of the six back-blowing nozzles 11 corresponds one-to-one with one of the six powder extraction pipes 5 on the powder pipe fixing frame 4. The powder pipe back-blowing devices 10 below the powder extraction pipe 5 are auxiliary systems to prevent screen blockage. They clean coarse particles on the screen by periodically spraying reverse airflow, ensuring the continuous and stable operation of the grading process. Please refer to [link / reference]. Figure 1 Each of the two gas inlet chambers 6 has a fluidized compressed air inlet 7 on its front end face. The fluidized compressed air inlet 7 is connected to the interior of the gas inlet chamber 6. The fluidized compressed air inlet 7 on the front end face of each of the two gas inlet chambers 6 serves to introduce compressed air. Please refer to [link / reference]. Figure 2 A tube bundle plate 8 is installed below the powder tube fixing bracket 4. The tube bundle plate 8 is sleeved and fixedly connected to the six powder extraction tubes 5. The tube bundle plate 8 installed below the powder tube fixing bracket 4 serves to bind and fix the powder extraction tubes 5. Please refer to [link / reference]. Figure 1 The two gas inlet chambers 6 are equipped with dense porous baffles. Compressed air is uniformly fluidized upwards through these baffles to recover the powder in the powder fluidizing box 1 and the fresh powder fluidizing box 2. Please refer to [link / reference]. Figure 1 The recovery fluidized bed 1 only receives metal powder recovered by cyclone separation, while the new fluidized bed 2 continuously replenishes it with new metal powder. Please refer to [link / reference]. Figure 1 The recycled powder fluidized box 1 and the new powder fluidized box 2 are respectively connected to independent powder pumps and six spray guns on four powder pipe fixing brackets 4. The two sets of spray guns are respectively connected to the independent powder pumps of the recycled powder fluidized box 1 and the new powder fluidized box 2.
[0022] Please see Figure 1-4 A fluidization method for a powder fluidization box based on dual independent fluidization units includes the following steps: Step 1: Connect the front row of spray guns to the fluidized bed 1 for recycled powder and connect the rear row of spray guns to the fluidized bed 2 for new powder. Divide the multiple spray guns arranged in parallel into front row and rear row spray gun groups according to their front and rear positions. There are 24 spray guns in total, divided into 12 in the front and 12 in the back, and each is matched with two independent powder pumps. Step 2: The recycled powder pump is connected to the bottom of the recycled powder fluidization tank 1 through a pipeline, and draws the fluidized recycled powder to the front spray gun group. The new powder pump is connected to the bottom of the new powder fluidization tank 2, and draws the uniform new powder to the rear spray gun group. Step 3: The front row of spray guns takes powder from the recycled powder fluidization box 1 and is mainly responsible for the basic spraying task; the rear row of spray guns takes powder from the new powder fluidization box 2 and uses the uniform new powder to cover up and correct any color differences that may exist in the front row, ultimately ensuring that the overall color of the profile surface is consistent. Step 4: The two sets of spray guns independently control the spraying parameters and adjust them precisely according to the profile position to achieve differentiated powder supply.
[0023] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
Claims
1. A powder fluidization box based on dual independent fluidization units, comprising two gas inlet chambers (6) arranged side by side; Its features are, Also includes: The recycled powder fluidizing box (1) and the new powder fluidizing box (2) are respectively welded to the upper end of the two gas inlet chambers (6), and the rear end of the recycled powder fluidizing box (1) and the new powder fluidizing box (2) are provided with mounting bases (3). Two powder pipe fixing brackets (4) are provided above the recycled powder fluidizing box (1) and the new powder fluidizing box (2). The four powder pipe fixing brackets (4) and the mounting bases (3) are an integral structure. A spoiler (9) is disposed inside the gas inlet chamber (6), and the spacing between two adjacent spoilers (9) is equal; The powder extraction pipe (5) is set on the powder pipe fixing frame (4), and there are six powder extraction pipes (5) on the four powder pipe fixing frames (4) respectively. The distance between two adjacent powder extraction pipes (5) is equal, and the powder extraction pipe (5) is connected to the spray gun.
2. The powder fluidization box based on dual independent fluidization units according to claim 1, characterized in that: Below the powder extraction pipe (5) is a powder pipe back-blowing device (10). There are four powder pipe back-blowing devices (10). Each of the four powder pipe back-blowing devices (10) has six back-blowing nozzles (11) at its upper end. The six back-blowing nozzles (11) correspond one-to-one with the six powder extraction pipes (5) on the powder pipe fixing frame (4).
3. The powder fluidization box based on dual independent fluidization units according to claim 1, characterized in that: Fluidized compressed air inlets (7) are provided on the front end faces of both gas inlet chambers (6), and the fluidized compressed air inlets (7) are connected to the interior of the gas inlet chambers (6).
4. A powder fluidizing box based on dual independent fluidizing units according to claim 1, characterized in that: Below the powder tube fixing frame (4) is a tube bundle plate (8), which is fixedly connected to six powder extraction tubes (5).
5. A powder fluidizing box based on dual independent fluidizing units according to claim 1, characterized in that: The two gas inlet chambers (6) are equipped with dense void partitions, through which compressed air is uniformly fluidized upwards to recover the powder in the powder fluidization box (1) and the new powder fluidization box (2).
6. A powder fluidizing box based on dual independent fluidizing units according to claim 1, characterized in that: The recovery powder fluidization box (1) only receives metal powder recovered by cyclone separation, and the new powder fluidization box (2) continuously replenishes new metal powder.
7. A powder fluidizing box based on dual independent fluidizing units according to claim 1, characterized in that: The recycled powder fluidized box (1) and the new powder fluidized box (2) are respectively connected to an independent powder pump and six spray guns on four powder pipe fixing brackets (4). The two sets of spray guns are respectively connected to the independent powder pumps of the recycled powder fluidized box (1) and the new powder fluidized box (2).
8. The fluidization method for a powder fluidization box based on dual independent fluidization units according to claim 1, characterized in that: Includes the following steps: Step 1: Connect the front row of spray guns to the fluidized bed of recycled powder (1) and connect the rear row of spray guns to the fluidized bed of new powder (2). Divide the multiple spray guns arranged in parallel into front row spray guns and rear row spray guns according to their front and rear positions. There are 24 spray guns, divided into 12 in the front and 12 in the back, and each is matched with two independent powder pumps. Step 2: The recycled powder pump is connected to the bottom of the recycled powder fluidization box (1) through a pipeline, and the fluidized recycled powder is extracted and transported to the front spray gun group. The new powder pump is connected to the bottom of the new powder fluidization box (2), and the uniform new powder is extracted and transported to the rear spray gun group. Step 3: The front row of spray guns takes powder from the recycled powder fluidization box (1) and mainly undertakes the basic spraying task; the rear row of spray guns takes powder from the new powder fluidization box (2) and uses the uniform new powder to cover up and correct the color difference that may exist in the front row, so as to ensure the overall color consistency of the profile surface. Step 4: The two sets of spray guns independently control the spraying parameters and adjust them precisely according to the profile position to achieve differentiated powder supply.