Atomization-multistage screening device and method for superfine metal powder

Abstract

The invention relates to a superfine metal powder atomizing-multi-stage screening device and method. The device comprises an atomizing chamber, a powder storage barrel and a multi-stage powder screening tower which are connected in sequence. The powder storage barrel is connected with the multi-stage powder screening tower through a powder feeding pipeline, and a valve is arranged on the powder feeding pipeline; the multi-stage powder screening tower comprises an ultrasonic screening device and a centrifugal screening device; the ultrasonic screener comprises a first-stage coarse screen and a second-stage ultrasonic vibrating screen, an ultrasonic transducer is mounted below the second-stage ultrasonic vibrating screen, and the ultrasonic transducer is connected with an ultrasonic generator; the centrifugal screening device comprises a spiral feeding assembly and a centrifugal screening assembly, and a centrifugal screen is arranged in the centrifugal screening assembly. Compared with the prior art, coarse powder and impurities are effectively removed through a multi-stage screening system, and uniformity and accuracy of powder size distribution are ensured. Various technologies such as atomization, pre-screening, ultrasonic vibration screening and centrifugal screening are integrated, automatic and continuous production of powder preparation is achieved, and the production efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of metal powder preparation and additive manufacturing, and in particular to an ultrafine metal powder atomization-multi-stage screening device and a method thereof. Background Art

[0002] Gas atomization powder preparation technology is an efficient and environmentally friendly method for powder production. It uses high-speed airflow to break up liquid metal into fine droplets, which are then cooled and solidified into powder. This technology is not only suitable for the preparation of single metal powders, but also for the synthesis of mixed metal powders. The powder prepared by gas atomization has the characteristics of high sphericity, good fluidity, and low oxygen content, providing an ideal raw material for selective laser melting (SLM) technology. Thanks to these excellent properties, gas atomized powders have been widely used in aerospace, automobile manufacturing, military industry, and medical industries, helping SLM technology to achieve rapid prototyping of high-density metal parts.

[0003] Ultrasonic sieving powder technology is an accurate powder grading method that uses ultrasonic vibration to improve the screening efficiency of fine powders. This technology effectively solves the problem of powder adhesion on the screen by introducing ultrasonic vibration during the screening process, improves the fluidity of the powder, and allows the powder to pass through the screen more evenly. Ultrasonic screening technology is particularly suitable for occasions that require high-precision screening, such as micron-diameter powders required for selective laser melting (SLM) technology.

[0004] In the field of additive manufacturing, the screening quality of powder has a decisive influence on the performance of the final printed parts. Existing screening technologies have many shortcomings when grading ultrafine metal powders, such as low screening efficiency, uneven particle size distribution, large powder loss, and poor equipment adaptability. Especially for additive manufacturing of multi-level microstructure materials, traditional screening methods are difficult to meet the requirements for precise control of powder particle size, resulting in unstable performance of printed parts. Ultrasonic screening technology is used in the area of ​​preparing 50-30μm diameter powders, but for ultrafine metal powders below 30μm, especially when the particle shape is irregular or easily affected by static electricity, there is no economical and efficient screening solution. Therefore, the development of an efficient, precise, and multi-level screening technology suitable for ultrafine powders has become the key to promoting the development of additive manufacturing technology.

[0005] Patent CN114273195A discloses a multi-stage screening device for metal powder, which includes a box, a feed port arranged at the upper end of the box, and a discharge port arranged at the lower end of the box, and also includes a screening unit arranged obliquely in the box, and a coarse material collection unit arranged on the side wall of the box and connected to the lowest end of the screening unit. However, it is limited to simple vibration screening, and cannot effectively remove coarse powder and impurities, and ensure the uniformity and accuracy of powder particle size distribution. Summary of the invention

[0006] The purpose of the present invention is to provide an ultrafine metal powder atomization-multi-stage screening device and method thereof in order to overcome the defects of the above-mentioned prior art, such as difficulty in accurately controlling the ultrafine powder particle size distribution and powder agglomeration. The device can complete the gas atomization and accurate fine screening of metal powder in the same system, ensuring that the prepared powder meets the high-precision additive manufacturing technology. At the same time, the whole device integrates a multi-stage screening unit, which can screen the atomized powder step by step to ensure the uniformity and accuracy of the powder particle size. The entire operation process realizes automated control, reduces manual intervention, and improves production efficiency and powder quality.

[0007] The present invention integrates atomization and multi-stage screening technology into one, and effectively removes coarse powder and agglomerated particles through three-stage screening of pre-screening, ultrasonic screening and centrifugal screening, thereby improving the uniformity and precision of powder particle size. Ultrasonic screening and centrifugal screening respectively solve the problems of powder adhesion and similar particle size, further reducing powder loss. The multi-stage screening unit ensures precise control of powder particle size, and the automated control system improves production efficiency and reduces human errors. The present invention is suitable for a variety of metal powders, has good versatility and adaptability, provides ideal raw materials for high-precision additive manufacturing technology, and has broad application prospects. It integrates high-speed airflow atomization and multi-stage screening technology for the efficient preparation of ultrafine metal powders. The integrated design and automated control system improve production efficiency.

[0008] The present invention provides an ultrafine metal powder atomization-multi-stage screening device, comprising: an atomization chamber, a powder storage barrel, and a multi-stage powder screening tower connected in sequence;

[0009] The powder storage barrel is connected to the multi-stage powder screening tower via a powder delivery pipeline, and a valve is provided on the powder delivery pipeline;

[0010] The multi-stage powder screening tower includes: an ultrasonic screener and a centrifugal screener; the ultrasonic screener includes: a first-stage coarse screen, a second-stage ultrasonic vibration screen, an ultrasonic transducer is installed below the second-stage ultrasonic vibration screen, the ultrasonic transducer is connected to an ultrasonic generator, the ultrasonic generator is used to generate a high-frequency electrical signal, and the ultrasonic transducer is used to convert the electrical signal into an ultrasonic wave; the centrifugal screener includes: a spiral feeding assembly and a centrifugal screening assembly, the centrifugal screening assembly is provided with a centrifugal screen, and the spiral feeding assembly includes a single screw for transporting powder to the centrifugal screening assembly.

[0011] Furthermore, the atomization chamber is connected to the powder storage barrel via a first flange.

[0012] Furthermore, the valve provided on the powder delivery pipeline between the powder storage barrel and the multi-stage powder screening tower is a butterfly valve.

[0013] Furthermore, a blower is provided on the powder delivery pipeline between the powder storage barrel and the multi-stage powder screening tower, which is used to transport the solidified metal powder along the powder delivery pipeline to the top of the multi-stage powder screening tower.

[0014] Furthermore, the ultrasonic sifter is provided with an induced draft fan for extracting gas from the ultrasonic sifter.

[0015] Furthermore, the first-stage coarse screen is connected to the ultrasonic screener through a spring.

[0016] Furthermore, the centrifugal screen is a horizontal cylindrical screen.

[0017] Furthermore, the centrifugal screening assembly is provided with a rotating main shaft, and the rotating main shaft drives the fixed blades to rotate at high speed.

[0018] Furthermore, the spiral feeding assembly and the centrifugal screening assembly are connected via a second flange.

[0019] The present invention also provides an ultrafine metal powder atomization-multi-stage screening method, comprising the following steps:

[0020] S1: Powder particle precipitation and collection in the atomization chamber: The metal powder cooled and solidified in the atomization chamber enters the powder storage barrel below; the valve below the powder storage barrel is opened, and the solidified metal powder is transported to the top of the multi-stage powder screening tower along the powder delivery pipeline under the action of the blower.

[0021] S2: First-stage metal powder pre-screening: When the powder reaches the top layer of the multi-stage powder screening tower, it falls onto the first-stage coarse screen and is vibrated and screened by an external motor to remove coarse metal powder. The powder that passes through the first-stage coarse screen continues to fall onto the second-stage ultrasonic vibration screen. An ultrasonic transducer is installed under the second-stage ultrasonic vibration screen, which is powered by an ultrasonic power supply and uses a high-frequency and small-amplitude mode to screen the fine-grained metal powder again.

[0022] S3: Centrifugal screening: Metal powders screened by ultrasonic vibration will agglomerate due to conductivity. For some powders with high viscosity or similar particle size, centrifugal screening can screen the powder more efficiently. After collecting the metal powder screened by the ultrasonic screener, the powder feeding speed is controlled by the spiral feeding assembly below, and the powder is transported to the centrifugal screening assembly equipped with a rotating spindle, driving the fixed blades to rotate at high speed. A horizontal cylindrical screen is installed inside, allowing the fine powder to pass through the horizontal cylindrical screen under the action of centrifugal force and be collected by the discharge port below.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] Through the multi-stage screening system, the present invention can screen the atomized metal powder step by step, effectively remove coarse powder and impurities, and ensure the uniformity and accuracy of the powder particle size distribution. This is crucial for high-precision additive manufacturing technology, which can improve the performance and stability of printed parts and reduce defects in the printing process. It can also effectively remove impurities and agglomerates in the powder, improve the purity and fluidity of the powder. This helps to improve the spreadability of subsequent powders. Finally, the present invention integrates multiple technologies such as atomization, pre-screening, ultrasonic vibration screening and centrifugal screening, and realizes the automation and continuous production of powder preparation, which greatly improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of an ultrafine metal powder atomization-multi-stage screening device;

[0026] Figure 2 The figure is a flow chart of the ultrafine metal powder atomization-multi-stage screening method.

[0027] Figure numerals: 1-atomizing chamber; 2-first flange; 3-powder storage barrel; 4-butterfly valve; 5-blower; 6-powder delivery pipeline; 7-spring; 8-induced draft fan; 9-first stage coarse screen; 10-ultrasonic generator; 11-ultrasonic transducer; 12-second flange; 13-single screw; 14-centrifugal screen; 15-powder collection bin. DETAILED DESCRIPTION

[0028] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms and other features not clearly described in this technical solution are all considered to be common technical features disclosed in the prior art.

[0029] Example 1

[0030] This embodiment provides an ultra-fine metal powder atomization-multi-stage screening device, such as Figure 1 As shown, it includes: an atomization chamber 1, a powder storage barrel 3, and a multi-stage powder screening tower connected in sequence;

[0031] The powder storage barrel 3 is connected to the multi-stage powder screening tower via a powder delivery pipeline 6, and a valve is provided on the powder delivery pipeline 6;

[0032] The multi-stage powder screening tower includes: an ultrasonic screener and a centrifugal screener; the ultrasonic screener includes: a first-stage coarse screen 9, a second-stage ultrasonic vibration screen, an ultrasonic transducer 11 is installed under the second-stage ultrasonic vibration screen, the ultrasonic transducer 11 is connected to an ultrasonic generator 10, the ultrasonic generator 10 is used to generate a high-frequency electrical signal, and the ultrasonic transducer 11 is used to convert the electrical signal into an ultrasonic wave; the centrifugal screener includes: a spiral feeding assembly, a centrifugal screening assembly, a centrifugal screen 14 is provided in the centrifugal screening assembly, and the spiral feeding assembly includes a single screw 13 for transporting powder to the centrifugal screening assembly.

[0033] In a specific implementation, the atomization chamber 1 is connected to the powder storage barrel 3 via a first flange 2 .

[0034] In a specific embodiment, the valve provided on the powder delivery pipeline 6 between the powder storage barrel 3 and the multi-stage powder screening tower is a butterfly valve 4 .

[0035] In a specific embodiment, a blower 5 is provided on the powder delivery pipeline 6 between the powder storage barrel 3 and the multi-stage powder screening tower, for transmitting the solidified metal powder along the powder delivery pipeline 6 to the top of the multi-stage powder screening tower.

[0036] In a specific embodiment, the ultrasonic sifter is provided with an induced draft fan 8 for extracting gas from the ultrasonic sifter.

[0037] In a specific embodiment, the first-stage coarse screen 9 is connected to the ultrasonic screener through a spring 7 .

[0038] In a specific embodiment, the centrifugal screen 14 is a horizontal cylindrical screen.

[0039] In a specific embodiment, a rotating main shaft is provided in the centrifugal screening assembly, and the rotating main shaft drives the fixed blades to rotate at high speed.

[0040] In a specific implementation, the spiral feeding assembly and the centrifugal screening assembly are connected via a second flange 12 .

[0041] This embodiment also provides a method for atomizing and screening ultrafine metal powders. Figure 2 As shown, the following steps are included:

[0042] S1: Powder particle precipitation and collection in the atomization chamber: The metal powder cooled and solidified in the atomization chamber 1 enters the powder storage barrel 3 below; the valve below the powder storage barrel 3 is opened, and the solidified metal powder is transported to the top of the multi-stage powder screening tower along the powder delivery pipe 6 under the action of the blower 5.

[0043] S2: First-stage metal powder pre-screening: When the powder reaches the top layer of the multi-stage powder screening tower, it falls onto the first-stage coarse screen 9, and is vibrated and screened by an external motor to remove coarse metal powder. The powder that passes through the first-stage coarse screen 9 continues to fall onto the second-stage ultrasonic vibration screen. An ultrasonic transducer 11 is installed under the second-stage ultrasonic vibration screen, which is powered by an ultrasonic power supply and uses a high-frequency and small-amplitude mode to screen the fine-grained metal powder again.

[0044] S3: Centrifugal screening: Metal powders screened by ultrasonic vibration will agglomerate due to conductivity. For some powders with high viscosity or similar particle size, centrifugal screening can screen the powder more efficiently. After collecting the metal powder screened by the ultrasonic screener, the powder feeding speed is controlled by the spiral feeding assembly below, and the powder is transported to the centrifugal screening assembly equipped with a rotating spindle, driving the fixed blades to rotate at high speed. A horizontal cylindrical screen is installed inside, allowing the fine powder to pass through the horizontal cylindrical screen under the action of centrifugal force and be collected by the discharge port below.

[0045] Components not described in detail in this embodiment are all existing components that can be purchased through public channels.

[0046] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. An ultrafine metal powder atomization-multi-stage screening device, characterized in that: It comprises: an atomization chamber (1), a powder storage barrel (3), and a multi-stage powder screening tower connected in sequence; The powder storage barrel (3) is connected to the multi-stage powder screening tower via a powder delivery pipeline (6), and a valve is provided on the powder delivery pipeline (6); The multi-stage powder screening tower comprises: an ultrasonic screener and a centrifugal screener; the ultrasonic screener comprises: a first-stage coarse screen (9) and a second-stage ultrasonic vibration screen, an ultrasonic transducer (11) is installed below the second-stage ultrasonic vibration screen, and the ultrasonic transducer (11) is connected to an ultrasonic generator (10); the centrifugal screener comprises: a screw feeding assembly and a centrifugal screening assembly, the centrifugal screening assembly is provided with a centrifugal screen (14), and the screw feeding assembly comprises a single screw (13) for transporting powder to the centrifugal screening assembly.

2. The ultrafine metal powder atomization-multi-stage screening device according to claim 1, characterized in that: The atomization chamber (1) is connected to the powder storage barrel (3) via a first flange (2).

3. The ultrafine metal powder atomization-multi-stage screening device according to claim 1, characterized in that: The valve provided on the powder delivery pipeline (6) between the powder storage barrel (3) and the multi-stage powder screening tower is a butterfly valve (4).

4. The ultrafine metal powder atomization-multi-stage screening device according to claim 1, characterized in that: A blower (5) is provided on the powder delivery pipeline (6) between the powder storage barrel (3) and the multi-stage powder screening tower, and is used to transport the solidified metal powder along the powder delivery pipeline (6) to the top of the multi-stage powder screening tower.

5. The ultrafine metal powder atomization-multi-stage screening device according to claim 1, characterized in that: The ultrasonic sifter is provided with an induced draft fan (8) for extracting gas from the ultrasonic sifter.

6. The ultrafine metal powder atomization-multi-stage screening device according to claim 1, characterized in that: The first-stage coarse screen (9) is connected to the ultrasonic screener via a spring (7).

7. The ultrafine metal powder atomization-multi-stage screening device according to claim 1, characterized in that: The centrifugal screen (14) is a horizontal cylindrical screen.

8. The ultrafine metal powder atomization-multi-stage screening device according to claim 1, characterized in that: The centrifugal screening assembly is provided with a rotating main shaft, and the rotating main shaft drives the fixed blades to rotate at high speed.

9. The ultrafine metal powder atomization-multi-stage screening device according to claim 1, characterized in that: The spiral feeding component and the centrifugal screening component are connected via a second flange (12).

10. An ultrafine metal powder atomization-multi-stage screening method according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1: Powder particle precipitation and collection in the atomization chamber: The metal powder cooled and solidified in the atomization chamber (1) enters the powder storage barrel (3) below; the valve below the powder storage barrel (3) is opened, and the solidified metal powder is transported to the top of the multi-stage powder screening tower along the powder delivery pipe (6) under the action of the blower (5); S2: First-stage metal powder pre-screening: When the powder reaches the top layer of the multi-stage powder screening tower, it falls onto the first-stage coarse screen (9), and is vibrated and screened by an external motor to remove coarse metal powder. The powder that has passed through the first-stage coarse screen (9) continues to fall onto the second-stage ultrasonic vibration screen. An ultrasonic transducer (11) is installed below the second-stage ultrasonic vibration screen, which is powered by an ultrasonic power supply and uses a high-frequency and small-amplitude mode to screen the fine metal powder again. S3: Centrifugal screening: After collecting the metal powder screened by the ultrasonic screener, the powder feeding speed is controlled by the spiral feeding assembly below, and the powder is transported to the centrifugal screening assembly equipped with a rotating spindle, driving the fixed blades to rotate at high speed. A horizontal cylindrical screen is installed inside, allowing the fine powder to pass through the horizontal cylindrical screen under the action of centrifugal force and be collected by the discharge port below.

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