Powder mixing device

Abstract

The utility model belongs to the field of additive manufacturing, especially, relate to a powder mixing device, this powder mixing device includes negative pressure suction equipment, pipeline and powder bucket group, powder bucket group at least includes first powder bucket and second powder bucket, negative pressure suction equipment is linked with first powder bucket and second powder bucket respectively through the pipeline intercommunication, the utility model provides a powder mixing device that safety degree is high, powder mixes more evenly and intelligent degree is higher.

Description

Technical Field

[0001] This utility model belongs to the field of additive manufacturing and relates to a powder mixing equipment, and more particularly to a powder mixing device. Background Technology

[0002] As metal additive manufacturing equipment matures, a certain amount of recycled powder is generated upon completion of the manufacturing process. To ensure consistent powder performance, the need for automated mixing of different batches of metal powder has emerged. Using argon as a protective gas for powder mixing reduces the probability of safety risks associated with traditional mixing methods and ensures thorough and uniform mixing of different batches of metal powder. Traditional metal powder mixing methods use air-based mixing. However, due to the conductivity of metal powder, this method can easily generate static electricity in a confined environment, potentially leading to dust explosions. Furthermore, the pursuit of uniform mixing in traditional methods results in powder oxidation upon heating, affecting the subsequent sintering performance of the metal powder. In addition, the lack of proper sealing in traditional equipment during mixing can lead to powder leakage, endangering the health of operators. Utility Model Content

[0003] In order to solve the above-mentioned technical problems in the background art, the present invention provides a powder mixing device with high safety, more uniform powder mixing and higher level of intelligence.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A powder mixing device, characterized in that: the powder mixing device includes a negative pressure suction device, a pipeline, and a powder barrel assembly; the powder barrel assembly includes at least a first powder barrel and a second powder barrel; the negative pressure suction device is connected to the first powder barrel and the second powder barrel respectively through the pipeline.

[0006] The aforementioned powder hopper assembly also includes valve bodies mounted on the powder hoppers, the number of which corresponds to the number of powder hoppers. Preferably, the valve bodies are butterfly valves, solenoid valves, electric ball valves, or proportional valves; the powder hoppers in the powder hopper assembly are connected to pipelines through the valve bodies.

[0007] The powder mixing device described above also includes an inert gas tank connected to the valve body; the inert gas tank is connected to a pipeline through the valve body.

[0008] The aforementioned negative pressure suction device is a vacuum pump.

[0009] The powder mixing device described above also includes a cyclone separator connected to a negative pressure suction device; the pipeline is connected to the cyclone separator; the powder mixing device also includes a negative pressure gauge and / or an oxygen content gauge installed on the cyclone separator.

[0010] The powder mixing device also includes a static mixing device connected to a cyclone separator.

[0011] The powder mixing device described above also includes a powder collecting device placed at the bottom of the static mixing device and connected to the static mixing device. Preferably, an on / off valve is provided between the static mixing device and the powder collecting device. The on / off valve is a solenoid valve, an electric ball valve, or a butterfly valve.

[0012] The powder mixing device also includes a vertical fixed frame parallel to the axial direction of the cyclone separator; the cyclone separator, static mixing equipment and / or powder collection equipment are connected to the vertical fixed frame.

[0013] The advantages of this utility model are:

[0014] This invention provides a powder mixing device, comprising a negative pressure suction device, a pipeline, and a powder barrel assembly. The powder barrel assembly includes at least a first powder barrel and a second powder barrel. The negative pressure suction device is connected to the first and second powder barrels respectively via the pipeline. This invention utilizes the negative pressure suction generated by the negative pressure suction device to extract powder from different powder barrels sequentially, alternately, or simultaneously. The powder collides with each other or with the inner wall of the pipeline, achieving powder mixing, and finally discharges the powder from the pipeline. During extraction, mixing, and even homogenization, minimal manual intervention is required, resulting in a higher degree of automation and operating efficiency. This invention employs a closed-loop system, ensuring complete system sealing and preventing powder leakage while meeting the requirement of uniform powder mixing. Furthermore, argon is used as a protective gas for the metal powder, and combined with oxygen meter detection, it significantly reduces the probability of metal powder oxidation and safety risks. Simultaneously, this invention uses a vacuum pump to drive the mixing of different batches of metal powder, ensuring orderly extraction of different batches while reducing worker workload. Moreover, this invention utilizes automated multi-step mixing of metal powder in pipelines, cyclone separators, and static mixers, achieving orderly mixing of different batches and ultimately ensuring uniform powder mixing. Attached Figure Description

[0015] Figure 1 This is a simplified structural diagram of the powder mixing device provided by this utility model;

[0016] Figure 2 This is a schematic diagram of the powder mixing device provided by this utility model;

[0017] Figure 3 This is a schematic diagram of a preferred structure of the powder mixing device provided by this utility model;

[0018] in:

[0019] 1-Powder collecting equipment; 2-Solenoid valve; 3-Vertical fixed frame; 4-Static mixing equipment; 5-Negative pressure gauge; 6-Cyclone separator; 7-Oxygen content gauge; 8-Vacuum pump; 9-Pipeline; 10-First powder hopper; 11-Second powder hopper; 12-Inert gas tank; 13-First butterfly valve; 14-Second butterfly valve. Detailed Implementation

[0020] See Figure 1 This invention provides a powder mixing device, including a negative pressure suction device, a pipe 9, and a powder barrel assembly. The powder barrel assembly includes at least a first powder barrel 10 and a second powder barrel 11 (exemplarily, multiple powder barrels can be used depending on the type of powder to be mixed). The negative pressure suction device is connected to the first powder barrel 10 and the second powder barrel 11 respectively through the pipe 9. In use, different powders are poured into different powder barrels, and then the negative pressure suction device is turned on. The negative pressure suction generated by the negative pressure suction device can extract powder from different powder barrels (such as the first powder barrel 10 and the second powder barrel 11) sequentially, alternately, or simultaneously. Since the powder is transported through the pipe 9, the extracted powder collides with each other or with the pipe 9, thus achieving powder mixing. Finally, the powder is discharged from the pipe 9. Obviously, this method requires less manual intervention when extracting, mixing, or even homogenizing, resulting in a higher degree of automation and higher operating efficiency. In some embodiments, the pipe 9 can be a spiral pipe, a coil pipe, or a straight pipe, which increases the running distance of the powder in the pipe 9 on the one hand, and also increases the probability of the powder colliding with the inner wall of the pipe 9 on the other hand, so as to achieve full mixing of the powder.

[0021] Taking the powder bucket assembly using two powder buckets (i.e., the first powder bucket 10 and the second powder bucket 11) and the pipe 9 being a spiral pipe as an example, the mixing scheme provided by this utility model is described as follows:

[0022] When powder is drawn from the powder bins in a sequential manner, for example, under the action of the negative pressure suction device, powder A is first drawn from the first powder bin 10 (powder A gathers at the negative pressure suction device after passing through the pipe 9), and then powder B is drawn from the second powder bin 11. Powder B runs in the spiral pipe 9 until it collides with powder A at the negative pressure suction device. Then, the mixture of powder A and powder B collides a second time with the inner wall of the pipe 9 to mix powder A and powder B evenly, and finally is discharged from the pipe 9 through the end of the negative pressure suction device.

[0023] When powder is drawn from the powder hopper in an alternating manner, for example, under the action of the negative pressure suction device, powder A is first drawn from the first powder hopper 10 at a preset time T1 (for example, the preset time T1 can be 10s, or shorter or longer, depending on the working conditions). Powder A gathers at the negative pressure suction device after passing through the pipe 9. Then, powder B is drawn from the second powder hopper 11 at a preset time T2 (for example, the preset time T2 can be the same as or different from the preset time T1, for example, it can be 8s, or shorter or longer, depending on the working conditions). Powder B runs in the spiral pipe 9 until it collides with powder A at the negative pressure suction device. Then, powder A is drawn from the first powder hopper 10 at a preset time T3. Powder A collides with powder A and powder B at the negative pressure suction device after passing through the pipe 9, forming a mixed state. Assuming the preset time for drawing powder from the powder container is the same each time, and the amount of powder drawn from different powder containers is also the same each time, then the weight ratio of powder A to powder B in the aforementioned method is 2:1. Therefore, this method can be used to add or adjust the proportions of different powders accordingly, ultimately achieving the mixing of multiple substances in different proportions.

[0024] When powder is drawn from different powder hoppers simultaneously, the powder hopper group used in this invention also includes valve bodies installed on the powder hoppers. The number of valve bodies corresponds to the number of powder hoppers. For example, the valve bodies are butterfly valves, solenoid valves, electric ball valves, or proportional valves. The powder hoppers in the powder hopper group are connected to the pipe 9 through the valve bodies. Taking the aforementioned conditions (using a first powder hopper 10 and a second powder hopper 11, and the pipe 9 is a spiral pipe) as an example, a first butterfly valve 13 is installed on the first powder hopper 10, and a second butterfly valve 14 is installed on the second powder hopper. The opening of the first butterfly valve 13 and the second butterfly valve 14 is adjusted according to the proportion of powder to be mixed. Under the action of the negative pressure suction device, powder A and powder B are drawn simultaneously. Powder A and powder B run in the pipe 9 and collide with the pipe 9. After running to the end of the negative pressure suction device, they collide with the end of the negative pressure suction device and / or the inner wall of the pipe 9, and finally the mixing of powder A and powder B is completed. That is, the mixing ratio is controlled by controlling the flow rate of the valve body. In some embodiments, the first butterfly valve 13 and the second butterfly valve 14 can be replaced with proportional valves, and the proportional valves can be directly adjusted to achieve the same mixing effect.

[0025] Powder is drawn and mixed using negative pressure suction, which can fulfill the mixing requirements of powders such as ceramic powders, plastic powders, or other materials. However, for metal powders, an oxygen-free or low-oxygen environment is essential to prevent powder oxidation. Therefore, the powder mixing device provided by this invention also includes an inert gas tank 12 connected to the valve body, such as... Figure 3As shown, the inert gas tank 12 is connected to the pipeline 9 via a valve body. For example, the inert gas tank 12 can be filled with inert gases such as helium and / or argon. On one hand, a negative pressure suction device is used to create a negative pressure suction force; on the other hand, the inert gas tank 12 cleans the pipeline 9 and / or the negative pressure suction device (i.e., gas washing, to prevent air from entering and oxidizing the metal powder), reducing the internal oxygen content until it meets the requirements for uniform mixing of the metal powder. Furthermore, the inert gas inside the inert gas tank 12 also acts as a transport carrier for powder A and powder B, enabling uniform mixing of different powders under low-oxygen or oxygen-free conditions.

[0026] For example, the negative pressure suction device can be a vacuum pump 8 or other equivalent device, the structure, working principle and working method of which are all prior art and will not be described in detail here.

[0027] The powders are initially mixed via pipeline 9. To further solidify the mixing effect, the powder mixing device provided in this invention also includes a cyclone separator 6 connected to a vacuum pump 8; pipeline 9 is connected to the cyclone separator 6. The cyclone separator 6 generates rotational motion through the tangential introduction of airflow, causing solid powders with significant inertial centrifugal force to separate towards the outer wall, thus separating powders from large particles. To monitor the oxygen content and negative pressure value before and during powder mixing in real time, the powder mixing device also includes a negative pressure gauge 5 and / or an oxygen content gauge 7 mounted on the cyclone separator 6. Furthermore, the powder mixing device provided in this invention also includes a static mixing device 4 placed at the bottom of the cyclone separator 6 or at its output end and connected to it. The cyclone separator 6 and the static mixing device 4 allow for multiple thorough mixing of different powders. To collect the homogenized powder mixture, this invention further includes a powder collecting device 1 located at the bottom of the static mixing device 4 and connected to it. Preferably, an on / off valve, such as a solenoid valve 2, an electric ball valve, or a butterfly valve, is provided between the static mixing device 4 and the powder collecting device 1. Exemplarily, the static mixing device 4 utilizes a mixing unit fixed inside a pipe to change the flow state of the powder within the pipe, achieving good dispersion and thorough mixing of different powders. This device can be authorized by publication number CN218964039U. The static mixing device 4 transfers the homogenized metal powder to the powder collecting device 1, which is used to store the homogenized metal powder and is a normally closed structure, such as a powder collecting hopper.

[0028] In addition, to ensure the stability of the powder mixing device provided by this utility model, a vertical fixing frame 3 parallel to the axial direction of the cyclone separator 6 is also included; the cyclone separator 6, the static mixing device 4 and / or the powder collecting device 1 are connected to the vertical fixing frame 3 to fix the entire device and prevent it from tipping over.

[0029] by Figure 3 Taking the structure shown as an example, the powder mixing device provided by this utility model includes four key steps in its specific operation: startup, gas washing, normal operation, and shutdown. Before startup, ensure that the system connection and sealing are intact; during gas washing, the solenoid valve 2 is in the open state, the first butterfly valve 13 and the second butterfly valve 14 are in the closed state, the inert gas tank 12 is opened, and after the inert gas tank 12 has been working for a period of time, the oxygen content in the pipeline 9 is measured by the oxygen content meter 7. When the content reaches the standard, the equipment operates normally. At this time, solenoid valve 2 is in the open state, vacuum pump 8 is turned on to draw negative pressure, first butterfly valve 13 is turned on to draw powder A from first powder tank 10. After a certain amount of powder A is drawn, first butterfly valve 13 is closed and second butterfly valve 14 is turned on to draw powder B from second powder tank 11, so that powder A and powder B are initially mixed in pipe 9. The mixed powder formed by powder A and powder B reaches cyclone separator 6, where it is further mixed and large metal powder particles are screened out. Then, it is thoroughly mixed evenly by static mixing equipment 4. After the powder is evenly mixed, it falls into powder collection equipment 1 to complete the powder mixing work. When stopping the machine, vacuum pump 8, first butterfly valve 13, second butterfly valve 14 and solenoid valve 2 and other electrical equipment are turned off.

[0030] For example, the working process of the powder mixing device provided by this utility model can be as follows:

[0031] 1) Construct the powder mixing device as described above;

[0032] 2) Activate the negative pressure suction device to create negative pressure within pipe 9, drawing powder from the powder hopper group sequentially, alternately, or simultaneously. The powder moves within pipe 9 and collides with it, mixing the powder to form a powder mixture. Preferably, the sequential method involves first drawing powder from the first powder hopper 10 and then from the second powder hopper 11. Preferably, the alternating method involves first drawing powder from the first powder hopper 10 at a preset time T1, then from the second powder hopper 11 at a preset time T2, then from the first powder hopper 10 at a preset time T3, and then from the second powder hopper 11 at a preset time T4, repeating this process. For example, the preset times T1, T2, T3, and T4 may be the same or different. Preferably, the simultaneous method involves first adjusting or controlling the opening Φ between the first powder hopper 10 and pipe 9. A And adjust or control the opening Φ between the second powder hopper 11 and the pipe 9. B According to Φ A and Φ B The powder is simultaneously drawn from both the first powder hopper 10 and the second powder hopper 11.

[0033] The powder mixing method further includes a process of purging the pipeline 9 and / or the negative pressure suction device with inert gas between step 1) and step 2); preferably, after the purging is completed, the powder is drawn from the powder bucket group in a sequential, alternating or simultaneous manner using inert gas as a carrier.

[0034] 3) The powder mixture obtained in step 2) is mixed again through a cyclone separator 6 and / or a static mixing device 4 to finally achieve powder homogenization.

Claims

1. A powder mixing device, characterized in that: The powder mixing device includes a negative pressure suction device, a pipe (9), and a powder bucket group; the powder bucket group includes at least a first powder bucket (10) and a second powder bucket (11); the negative pressure suction device is connected to the first powder bucket (10) and the second powder bucket (11) respectively through the pipe (9).

2. The powder mixing device according to claim 1, characterized in that: The powder bucket group also includes valve bodies installed on the powder buckets, the number of which corresponds to the number of powder buckets; the powder buckets in the powder bucket group are connected to the pipe (9) through the valve bodies.

3. The powder mixing device according to claim 2, characterized in that: The valve body is a butterfly valve, solenoid valve, electric ball valve, or proportional valve.

4. The powder mixing device according to claim 3, characterized in that: The powder mixing device also includes an inert gas tank (12) connected to the valve body; the inert gas tank (12) is connected to the pipeline (9) through the valve body.

5. The powder mixing device according to claim 4, characterized in that: The negative pressure suction device is a vacuum pump (8).

6. The powder mixing apparatus according to any one of claims 1-5, characterized in that: The powder mixing device also includes a cyclone separator (6) connected to a negative pressure suction device; the pipe (9) is connected to the cyclone separator (6).

7. The powder mixing device according to claim 6, characterized in that: The powder mixing device also includes a negative pressure gauge (5) and / or an oxygen content gauge (7) installed on the cyclone separator (6).

8. The powder mixing apparatus according to claim 7, characterized in that: The powder mixing device also includes a static mixing device (4) connected to the cyclone separator (6).

9. The powder mixing apparatus according to claim 8, characterized in that: The powder mixing device also includes a powder collecting device (1) connected to the static mixing device (4).

10. The powder mixing apparatus according to claim 9, characterized in that: An on / off valve is provided between the static mixing device (4) and the powder collection device (1), and the on / off valve is a solenoid valve, an electric ball valve or a butterfly valve.

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