Closed type automatic powder feeding system for oxygen-free metal powder

Abstract

This invention discloses a closed-loop, oxygen-free, automatic powder supply system for metal powder, comprising: a powder storage unit configured to store metal powder under inert gas protection; an inert gas supply unit connected to the powder storage unit to establish and maintain an inert gas environment; a positive pressure conveying unit connected to the powder storage unit, using airflow to drive the powder to flow along the pipeline conveying path; an oxygen content and pressure monitoring unit connected to the powder storage unit to monitor oxygen concentration and pressure in real time and dynamically adjust the inert gas supply; and an electrical control unit connected to the powder storage unit, the inert gas supply unit, the positive pressure conveying unit, and the oxygen content and pressure monitoring unit. This invention achieves continuous powder supply without human intervention by dynamically maintaining the inert gas environment, ensuring the oxygen concentration of the powder remains at a safe threshold throughout the entire process from storage to conveying; and integrates intelligent control and multi-stage filtration to achieve unattended continuous powder supply, reducing manual intervention.

Description

Technical Field

[0001] This utility model relates to the field of metal powder technology, specifically to a closed-loop oxygen-free metal powder automatic powder supply system. Background Technology

[0002] In metal additive manufacturing, the oxygen content of the metal powder directly affects the mechanical properties of the formed parts. Traditional powder supply systems have the following drawbacks:

[0003] 1. Risk of powder oxidation: Open or semi-closed powder storage tanks are prone to contact with air during powder addition / transportation, which can lead to powder oxidation and deterioration.

[0004] 2. High dependence on manual operation: Frequent manual adjustment of gas pressure and clearing of pipe blockages are required, which can easily introduce operational errors and safety risks.

[0005] 3. Low conveying reliability: Gravity powder feeding is prone to pipe blockage due to differences in powder flowability, and is especially unsuitable for complex layouts.

[0006] 4. Poor compatibility with multiple devices: The existing system is difficult to achieve "one-to-many" toner supply, and the system needs to be shut down to change toner when switching devices, which is inefficient.

[0007] 5. Inadequate safety protection: The lack of real-time oxygen concentration and pressure monitoring may lead to powder leakage or pressure imbalance and cause an explosion.

[0008] To address the aforementioned issues, there is an urgent need for a fully enclosed, automated, multi-channel oxygen-free powder supply system. Utility Model Content

[0009] To address the shortcomings of existing technologies, this utility model provides a closed-loop automatic powder supply system for oxygen-free metal powder. By dynamically maintaining an inert gas environment, the oxygen concentration of the powder is kept at a safe threshold throughout the entire process from storage to transportation. It integrates intelligent control and multi-stage filtration to achieve unattended continuous powder supply and reduce manual intervention. It adopts positive pressure conveying and multi-channel closed-loop pipelines to solve the blockage problem and support "one-to-many" powder supply. Through oxygen content-pressure linkage regulation, it eliminates the risk of explosion and ensures operational safety.

[0010] To achieve the above objectives, this utility model provides the following technical solution:

[0011] A closed-loop automatic powder feeding system for oxygen-free metal powder includes:

[0012] A powder storage unit configured to store metal powder under inert gas protection;

[0013] An inert gas supply unit is connected to the powder storage unit to establish and maintain an inert gas environment;

[0014] A positive pressure conveying unit is connected to a powder storage unit and uses airflow to drive the powder to flow in the pipeline conveying path.

[0015] The oxygen content and pressure monitoring unit is connected to the powder storage unit to monitor the oxygen concentration and pressure in real time and dynamically adjust the inert gas supply.

[0016] The electrical control unit is connected to the powder storage unit, the inert gas supply unit, the positive pressure conveying unit, and the oxygen content pressure monitoring unit, respectively.

[0017] Furthermore, it also includes a multi-channel distribution module that connects to the electrical control unit, and the multi-channel distribution module connects to multiple metal additive manufacturing equipment simultaneously through independent closed-loop pipelines.

[0018] Furthermore, it also includes a first-stage filtration module and a second-stage filtration module arranged sequentially along the powder conveying pipeline; the first-stage filtration module is a cyclone separator used to separate large-diameter powder particles, and the second-stage filtration module is a circulating filter with a built-in sintered plastic plate filter element.

[0019] Furthermore, the powder storage unit is a sealed pressure vessel with a volume of ≥200L, and its outlet is connected to a powder discharge valve. The opening and closing of the powder discharge valve is triggered by the electrical control unit according to the powder supply request signal, and the opening action of the powder discharge valve is linked to the start and stop signal of the positive pressure conveying unit.

[0020] Furthermore, the inert gas supply unit includes a gas input pipeline and a gas output pipeline connected to a sealed pressure vessel; an inlet valve body is connected between the gas input pipeline and the sealed pressure vessel, an exhaust valve body is connected between the gas output pipeline and the sealed pressure vessel, and a gas purification and recovery unit is connected to the end of the gas output pipeline, the gas purification and recovery unit being connected to the inert gas supply unit.

[0021] Furthermore, the positive pressure conveying unit includes a pipe connected to the powder discharge valve of the sealed pressure vessel, and a blower connected to the pipe; the start and stop of the blower is triggered by the electrical control unit according to the powder supply request signal.

[0022] Furthermore, the oxygen content pressure monitoring system includes an oxygen content sensor and a pressure sensor connected to a sealed pressure vessel.

[0023] Furthermore, the oxygen content sensor is an electrochemical or laser oxygen analyzer.

[0024] This closed-loop automatic powder feeding system for oxygen-free metal powder has achieved the following beneficial effects:

[0025] 1. Full-process oxygen-free protection and quality assurance: Combining an inert gas supply unit and an oxygen content pressure monitoring unit, it ensures that the oxygen concentration of metal powder is maintained at a safe threshold throughout the entire process from storage and filtration to transportation, preventing oxidation and contamination, and significantly improving powder quality and additive manufacturing product performance.

[0026] 2. High-efficiency automation and production optimization: The electrical control unit coordinates the multi-channel distribution module, positive pressure conveying unit and linkage valve to achieve "one-to-many" powder supply, non-stop operation and on-demand conveying, which greatly improves production efficiency; the graded recycling structure of the filter reduces material waste and supports continuous operation.

[0027] 3. Enhanced safety and reliability: Real-time monitoring and dynamic adjustment mechanism for oxygen content and pressure, combined with gas purification and recovery, eliminates the risk of explosion and leakage, protects operator safety, ensures system stability, and reduces failure rate.

[0028] 4. Economic efficiency and environmental friendliness: Inert gas recovery and intelligent energy management reduce operating costs; closed-loop pipeline and filtration design reduce resource consumption and meet green manufacturing requirements.

[0029] In summary, this system solves the problems of oxidation, low efficiency, and safety risks in metal powder feeding, providing an efficient, safe, and reliable powder feeding solution for metal additive manufacturing. Attached Figure Description

[0030] Figure 1 The diagram shows the overall structure of a closed-loop oxygen-free metal powder automatic powder supply system.

[0031] Figure 2 The diagram shown is a partial structural schematic of a closed-loop automatic powder supply system for oxygen-free metal powder.

[0032] Figure 3 The diagram shows a partial structural schematic of a closed-loop automatic oxygen-free metal powder supply system.

[0033] In the diagram: 1. Powder storage unit; 2. Inert gas supply unit; 3. Positive pressure conveying unit; 4. Oxygen content and pressure monitoring unit; 5. Electrical control unit; 6. Multi-channel distribution module; 7. First-stage filtration module; 8. Second-stage filtration module; 101. Sealed pressure vessel; 102. Powder discharge valve; 201. Gas input pipeline; 202. Gas output pipeline; 203. Inlet valve body; 204. Exhaust valve body; 205. Gas purification and recovery unit; 301. Pipeline; 302. Blower; 401. Oxygen content sensor; 402. Pressure sensor; 501. Human-machine interface operation screen. Detailed Implementation

[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0035] See Figure 1-3 As shown, this utility model provides a technical solution: a closed-loop automatic powder feeding system for oxygen-free metal powder, comprising:

[0036] Powder storage unit 1 is configured to store metal powder under inert gas protection;

[0037] Inert gas supply unit 2 is connected to powder storage unit 1 to establish and maintain an inert gas environment;

[0038] The positive pressure conveying unit 3 is connected to the powder storage unit 1 and uses airflow to drive the powder to flow in the pipeline conveying path.

[0039] Oxygen content pressure monitoring unit 4 is connected to powder storage unit 1 to monitor oxygen concentration and pressure in real time and dynamically adjust the inert gas supply.

[0040] The electrical control unit 5 is connected to the powder storage unit 1, the inert gas supply unit 2, the positive pressure conveying unit 3, and the oxygen content pressure monitoring unit 4, respectively.

[0041] The integrated design of powder storage unit 1, inert gas supply unit 2, and oxygen content pressure monitoring unit 4 establishes and maintains an inert gas environment within the system. This ensures that the oxygen concentration of the metal powder remains within a safe threshold throughout the entire process from storage to transportation, preventing powder oxidation and deterioration, and improving powder quality and the performance of additive manufacturing products. The electrical control unit 5, as the core, coordinates the actions of each unit in real time, such as triggering powder supply or adjusting gas supply, enabling unattended operation and reducing human error. Simultaneously, the dynamic adjustment function of the oxygen content pressure monitoring unit 4 ensures stable system pressure, preventing powder leakage or explosion risks due to pressure imbalance and enhancing operator safety. The positive pressure conveying unit 3 uses airflow to drive powder flow, replacing traditional gravity conveying, avoiding powder blockage or interruption, achieving highly reliable continuous powder supply, and is suitable for long-distance or complex pipeline layouts.

[0042] See appendix Figure 1As shown, this closed-loop oxygen-free metal powder automatic powder supply system also includes a multi-channel distribution module 6 connected to the electrical control unit 5. The multi-channel distribution module 6 is simultaneously connected to multiple metal additive manufacturing equipment via independent closed-loop pipelines. It should be noted that each independent closed-loop pipeline is connected to a switching valve. The multi-channel distribution module 6 acts as a material distribution actuator, supplying powder to multiple metal additive manufacturing equipment through the electrical control unit 5, achieving a one-to-many powder supply mode, intelligent distribution, automatic channel switching according to equipment needs, optimizing resource utilization, continuous operation without downtime, reducing equipment waiting time, and significantly improving overall production efficiency.

[0043] This closed-loop, oxygen-free metal powder automatic powder feeding system also includes a first-stage filtration module 7 and a second-stage filtration module 8 arranged sequentially along the powder conveying pipeline. The first-stage filtration module 7 is a cyclone separator used to separate large-diameter powder particles, while the second-stage filtration module 8 is a circulating filter with a built-in sintered plastic filter element. The first-stage filtration module 7, with its cyclone separator structure, separates large-diameter powder particles in the initial stage of conveying, preventing pipeline blockage and equipment wear. The second-stage filtration module 8, with its circulating filter structure, captures fine particles in the later stage of conveying, ensuring uniform powder particle size and improving additive manufacturing precision. Both stages of filtration are completed automatically during the conveying process, avoiding downtime for cleaning and maintaining continuous system operation.

[0044] See appendix Figure 1-3 As shown, the powder storage unit 1 is a sealed pressure vessel 101 with a volume ≥200L. Its outlet is connected to a powder discharge valve 102. The opening and closing of the powder discharge valve 102 is triggered by the electrical control unit 5 based on a powder supply request signal, and the opening action of the powder discharge valve 102 is linked to the start / stop signal of the positive pressure conveying unit 3. The sealed pressure vessel 101 provides sufficient powder storage, reducing the need for frequent powder replenishment. The signal linkage design between the powder discharge valve 102 and the electrical control unit 5 ensures that the valve opens automatically only when a powder supply request is received, and the positive pressure conveying unit 5 starts simultaneously, preventing powder leakage or accumulation during non-powder supply periods. The signal linkage between the valve opening / closing and the positive pressure conveying unit 5 coordinates powder release and airflow delivery, preventing pipeline blockage or pressure fluctuations caused by timing errors, ensuring a smooth and efficient powder supply process, and further improving safety.

[0045] The inert gas supply unit 2 includes a gas inlet pipe 201 and a gas outlet pipe 202 connected to a sealed pressure vessel. An inlet valve body 203 connects the gas inlet pipe 201 to the sealed pressure vessel, and an exhaust valve body 204 connects the gas outlet pipe 202 to the sealed pressure vessel. A gas purification and recovery unit 205 is connected to the end of the gas outlet pipe 202, and the gas purification and recovery unit 205 is connected to the inert gas supply unit 2. The gas inlet pipe 201 and the gas outlet pipe 202 control the gas flow through the inlet valve body 203 and the exhaust valve body 204, achieving precise system pressure regulation and maintaining a stable inert environment. The structure of the gas purification and recovery unit 205 purifies and recycles the discharged gas, reducing inert gas consumption and lowering operating costs. It should be noted that the gas purification and recovery unit 205 can be any conventional gas purifier with gas purification functions. To further improve efficiency, a dust filter element is built into the gas purification and recovery unit 205.

[0046] The positive pressure conveying unit 3 includes a pipe 301 connected to the powder discharge valve 102 of the sealed pressure vessel, and a blower 302 connected to the pipe 301. The opening and closing of the blower 302 is triggered by the electrical control unit 5 based on the powder supply request signal. The blower 302 is automatically opened and closed by the electrical control unit 5 based on the powder supply request signal, and only starts the airflow to drive the powder when needed, avoiding energy consumption due to idling. The pipe structure, combined with the positive pressure airflow design, achieves efficient powder flow and is suitable for conveying paths of different distances and directions. The blower 302 is linked with the powder discharge valve 102 to ensure that the powder release is synchronized with the airflow, preventing powder from settling or clogging in the pipe.

[0047] The oxygen content and pressure monitoring system 4 includes an oxygen content sensor 401 and a pressure sensor 402 connected to the sealed pressure vessel. By designing the oxygen content sensor 401 and pressure sensor 402, the system monitors the oxygen concentration and system pressure in real time; dynamically adjusts the inert gas supply to ensure the oxygen concentration remains at a safe threshold, eliminating the risk of fire or explosion. It should be noted that when air needs to be replaced in the sealed pressure vessel 101, the powder supply signal is interrupted. Once the oxygen concentration in the sealed pressure vessel 101 is maintained at a safe threshold, the powder supply resumes. Simultaneously, the inert gas supply unit 2 stops working; that is, the inlet valve 203 and the exhaust valve 204 are closed simultaneously to prevent a small amount of powder from leaking through this path. Of course, a small amount of powder may leak through this path during inert gas replacement or maintenance. Therefore, a gas purification and recovery unit 205 is specifically provided. As mentioned above, to further improve efficiency, a dust filter element is built into the gas purification and recovery unit 205 to achieve dust recovery and prevent dust from affecting the normal operation of the internal structure of the inert gas supply unit 2.

[0048] The oxygen sensor 401 is an electrochemical or laser oxygen analyzer. The structure of the electrochemical or laser oxygen analyzer provides rapid and accurate oxygen content readings. Laser analyzers are particularly suitable for industrial environments and have strong anti-interference capabilities. This ensures that changes in oxygen content are detected instantly, and the inert gas supply unit 2 can be quickly adjusted to maintain a consistent low-oxygen or oxygen-free environment.

[0049] The electrical control unit 5 is equipped with a human-machine interface screen 501, which is used to set parameters such as oxygen content threshold, pressure threshold and powder supply signal.

[0050] The working process of this closed-loop automatic oxygen-free metal powder feeding system is as follows:

[0051] 1. System initialization and lazy environment setup

[0052] Step 1.1 Inert gas injection

[0053] The inert gas supply unit 2 injects nitrogen or argon into the sealed pressure vessel 101 through the gas input pipeline 201, while the exhaust valve body 204 opens to discharge residual air.

[0054] Step 1.2 Oxygen content monitoring and stabilization

[0055] The oxygen content sensor 401 monitors the oxygen concentration in the container in real time, and the electrical control unit 5 dynamically adjusts the intake valve body 203 and the exhaust valve body 204 until the oxygen concentration drops to a safe threshold. The pressure sensor 402 synchronously maintains the set positive pressure value.

[0056] 2. Powder supply request triggering and linkage start-up

[0057] Step 2.1 Receive powder supply signal

[0058] The electrical control unit 5 receives the powder supply request signal from the metal additive manufacturing equipment and distributes it to the target equipment channel through the multi-channel distribution module 6.

[0059] Step 2.2 Valve and blower linkage

[0060] Electrical control unit 5 synchronous triggering:

[0061] Open the powder discharge valve 102; start the blower 302 of the positive pressure conveying unit 3.

[0062] 3. Powder conveying and grading filtration

[0063] Step 3.1 Positive pressure airflow drive

[0064] Blower 302 generates airflow, which draws powder out of sealed pressure vessel 101 through pipe 301, forming an air-powder mixed flow.

[0065] Step 3.2 First-stage filtration

[0066] The mixed flow enters the cyclone separator, where centrifugal force separates large-diameter powder particles.

[0067] Step 3.3 Second-stage filtration

[0068] Airflow carries fine powder into a circulating filter, where a sintered plastic plate filter element captures the tiny particles. The powder is then transported by the airflow to the target additive manufacturing equipment.

[0069] 4. Powder supply termination and system standby

[0070] Step 4.1 Turn off the linkage unit

[0071] After the powder supply is completed, the electrical control unit 5 simultaneously closes the powder discharge valve 102 and the blower 302.

[0072] Step 4.2 Continuous Environmental Monitoring

[0073] The oxygen content pressure monitoring unit 4 continuously monitors the environment inside the container and dynamically adjusts the inert gas supply to maintain a low-oxygen or oxygen-free positive pressure state until the next powder supply request.

[0074] 5. Multi-device powder supply scheduling

[0075] If multiple devices need to be supplied simultaneously, the multi-channel distribution module 6 delivers powder to different devices in parallel through independent closed-loop pipelines according to the priority instructions of the electrical control unit 5.

Claims

1. A closed-loop automatic powder feeding system for oxygen-free metal powder, characterized in that, include: The powder storage unit (1) is configured to store metal powder under inert gas protection; An inert gas supply unit (2) is connected to a powder storage unit (1) to establish and maintain an inert gas environment; The positive pressure conveying unit (3) is connected to the powder storage unit (1) and uses airflow to drive the powder to flow in the pipeline conveying path; The oxygen content pressure monitoring unit (4) is connected to the powder storage unit (1) to monitor the oxygen concentration and pressure in real time and dynamically adjust the inert gas supply. The electrical control unit (5) is connected to the powder storage unit (1), the inert gas supply unit (2), the positive pressure conveying unit (3), and the oxygen content pressure monitoring unit (4), respectively.

2. The closed-loop oxygen-free metal powder automatic powder feeding system according to claim 1, characterized in that, It also includes a multi-channel distribution module (6) that is connected to the electrical control unit (5), and the multi-channel distribution module (6) is connected to multiple metal additive manufacturing equipment simultaneously through independent closed-loop pipelines.

3. The closed-loop automatic powder feeding system for oxygen-free metal powder according to claim 1 or 2, characterized in that, It also includes a first-stage filtration module (7) and a second-stage filtration module (8) arranged sequentially along the powder conveying pipeline; the first-stage filtration module (7) is a cyclone separator used to separate large-diameter powder particles, and the second-stage filtration module (8) is a circulating filter with a built-in sintered plastic plate filter element.

4. The closed-loop automatic powder feeding system for oxygen-free metal powder according to claim 1, characterized in that, The powder storage unit (1) is a sealed pressure vessel (101) with a volume ≥200L. Its outlet is connected to a powder discharge valve (102). The opening and closing of the powder discharge valve (102) is triggered by the electrical control unit (5) according to the powder supply request signal. The opening action of the powder discharge valve (102) is linked with the start and stop signal of the positive pressure conveying unit (3).

5. The closed-loop automatic powder feeding system for oxygen-free metal powder according to claim 4, characterized in that, The inert gas supply unit (2) includes a gas input pipeline (201) and a gas output pipeline (202) connected to a sealed pressure vessel; an inlet valve body (203) is connected between the gas input pipeline (201) and the sealed pressure vessel, an exhaust valve body (204) is connected between the gas output pipeline (202) and the sealed pressure vessel, and a gas purification and recovery unit (205) is connected to the end of the gas output pipeline (202), and the gas purification and recovery unit (205) is connected to the inert gas supply unit (2).

6. The closed-loop automatic powder feeding system for oxygen-free metal powder according to claim 4, characterized in that, The positive pressure conveying unit (3) includes a pipe (301) connected to the powder discharge valve (102) of the sealed pressure vessel, and a blower (302) connected to the pipe (301); the opening and closing of the blower (302) is triggered by the electrical control unit (5) according to the powder supply request signal.

7. The closed-loop oxygen-free metal powder automatic powder feeding system according to claim 4, characterized in that, The oxygen content pressure monitoring unit (4) includes an oxygen content sensor (401) and a pressure sensor (402) connected to a sealed pressure vessel.

8. The closed-loop oxygen-free metal powder automatic powder feeding system according to claim 7, characterized in that, The oxygen content sensor (401) is an electrochemical or laser oxygen analyzer.

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