Nanopowder Manufacturing Method

Abstract

The present application relates to the technical field of nanopowder production, and more particularly, to a method for producing nanopowder. The present application discloses an apparatus for producing nanopowder, comprising an evaporator and an arc generator. The arc generator is drilled at the top of the evaporator, and an arc sheath gas passage is formed in the arc generator, with one end communicating with the inside of the evaporator and the other end communicating with the outside. When producing nanopowder using the apparatus, arc sheath gas is introduced into the apparatus and acts directly on the high-temperature core region of the arc, thereby improving the temperature gradient in the core region and directly reducing the concentration of vapor around the arc, thereby suppressing excessive collisions between atoms of the raw material and reducing the possibility of a rapid increase in the particle size of the nanoparticles. Under the assumption that the arc current is high and the yield is high, the nanopowder can be guaranteed to have a small particle size.

Description

Technical Field

[0001] This application relates to the technical field of nano-powder production, and more specifically, to a method for producing nano-powders.

Background Art

[0002] Nano-powders generally refer to particles with sizes between those of atoms, molecules, and macroscopic substances. Their sizes are larger than atomic clusters but smaller than ordinary fine powders. Currently, they are widely applied in fields such as improving the surface performance of workpieces such as coating and film coating, and realizing high-precision manufacturing. Generally, nano-powders are required to have an average particle size of 100 nm or less, a narrow particle size distribution, and a suitable spherical shape.

[0003] There are various methods for producing nano-powders. The direct current arc plasma method belongs to the gas evaporation method and is an ideal method for producing nano-powders. An arc generates high-energy plasma to heat and evaporate the raw material. Then, the vapor condenses and aggregates to form nano-particles. Nano-powders produced by the arc method have advantages such as high purity and good sphericity.

[0004] In order to improve the output of nano-powders, the industry usually uses a method of increasing the arc current and inputting high energy. When the arc current is increased, the raw material evaporates大量 in a short time, further increasing the concentration of the vapor. When the vapor becomes too saturated, the collision between the atoms of the raw material becomes intense, and the particle size of the nano-powder increases rapidly. When the arc current is decreased, nano-powders with a small particle size can be obtained, but the output of the nano-powders decreases. Therefore, how to obtain nano-powders with a small particle size on the premise of ensuring a high output is an urgent problem to be solved in the industry.

Summary of the Invention

[0006] In the first aspect, the present application provides a nanopowder manufacturing apparatus using the following technical means.

[0007] A nanopowder manufacturing apparatus comprising an evaporator, an arc generator, and a cooling and collection chamber, wherein a supply pipe is drilled in the evaporator, and a main sheath gas inlet and outlet are installed horizontally, the outlet communicating with the cooling and collection chamber, the arc generator is drilled in the top of the evaporator, a crucible is installed inside the evaporator, the arc generator is installed above the crucible, an arc sheath gas passage is formed in the arc generator, one end of the arc sheath gas passage communicates with the inside of the evaporator and the other end communicates with the outside.

[0008] According to the above technical means, a main sheath gas inlet is formed horizontally in the evaporator, and an arc sheath gas passage is formed in the arc generator. When the arc generator is started, the raw materials on the crucible evaporate at high temperature and become vapor. Sheath gas is introduced into the evaporator through the main sheath gas inlet and the arc sheath gas passage. The arc sheath gas directly acts on the high-temperature core region caused by the arc, improving the temperature gradient in the core region and directly reducing the concentration of vapor around the arc. This suppresses excessive collisions between atoms of the raw materials and reduces the possibility of a rapid increase in nanoparticle size. The main sheath gas assists the arc sheath gas in reducing the vapor concentration while blowing the formed nanoparticles into the cooling and collection chamber.

[0009] Based on the above, by combining the arc sheath gas and the main sheath gas, it is possible to obtain nanopowder with small particle size at a high arc current, thus overcoming the contradiction between high nanopowder production and small particle size.

[0010] Preferably, a plurality of auxiliary sheath gas inlets are further formed at the top of the evaporator.

[0011] According to the above technical means, by introducing auxiliary sheath gas into multiple auxiliary sheath gas inlets and combining the auxiliary sheath gas with the main sheath gas and arc sheath gas, the concentration of the raw material vapor is further reduced, thereby further reducing the possibility that the particle size of the nanopowder will be too large at high arc currents.

[0012] Preferably, an annular groove is formed at one end located inside the evaporator of the arc generator, and a strip-shaped passage is formed in the arc generator along its own length, with one end of the strip-shaped passage communicating with the outside and the other end communicating with the annular groove, and the annular groove and the strip-shaped passage together constitute an arc sheath gas passage.

[0013] According to the above technical means, the arc sheath gas enters the annular groove via a strip-shaped passage and then diffuses into the high-temperature core region formed by the arc via the annular groove. The annular groove guides the arc sheath gas to diffuse uniformly around the high-temperature core region, further reducing the possibility of excessive particle size due to excessive collisions between atoms of the raw materials.

[0014] Preferably, the nanopowder manufacturing apparatus further includes an intake assembly, the intake assembly including an intake ring installed inside an evaporator, an intake pipe whose exhaust end communicates with a cooling collection chamber, and a connecting pipe connecting the intake ring and the intake pipe, wherein the intake ring is located above the crucible, and a plurality of intake ports are provided on the inner ring of the intake ring, and two sealing frames are installed inside the intake pipe along the direction of airflow, with a sealing gate hinged to the side of the top of each sealing frame away from the connecting pipe, the sealing gates covering the openings of the sealing frames, a gas storage pipe communicating between the two sealing gates inside the intake pipe, a sealing plug slidably installed inside the gas storage pipe, a cylinder installed at the end of the gas storage pipe away from the intake pipe, the piston rod of the cylinder being drilled in the gas storage pipe and connected to the sealing plug.

[0015] According to the above technical means, the nanopowder formed by evaporation has a low cooling rate due to the high temperature in the arc's high-temperature core region, which allows the primary crystal grains to grow large and easily form large particles. The intake assembly, in combination with the main sheath gas, can accelerate the departure of the nanopowder from the arc's high-temperature core region and reduce particle growth of the nanopowder in the high-temperature core region.

[0016] In a second aspect, the present invention provides a method for producing nanopowder using the following technical means.

[0017] A nanopowder manufacturing method carried out in the nanopowder manufacturing apparatus, wherein the method is: Step S1 involves placing a metal solid in a crucible and replacing the air in the evaporator with an inert gas, Step S2 involves starting the power supply of the arc generator, adjusting the arc current to 200-500A so that the arc voltage is 40-120V, and adjusting the height of the arc generator, so that the metal solid evaporates into vapor due to the high temperature action of the arc. Step S3 includes introducing an arc sheath gas with a flow rate of 100-500 cc / min into the evaporator according to the magnitude of the arc current, introducing a main sheath gas with a flow rate of 500-1600 SLPM (standard liters per minute) into the evaporator to ensure that the average temperature inside the evaporator is 500-600 K, blowing vapor with the arc sheath gas and main sheath gas to diffuse it as nanopowder, mixing the nanopowder with the main sheath gas and sending it out of the evaporator through the outlet to obtain nanopowder with a particle size of 65-90 nm.

[0018] According to the above technical means, nanopowder is produced using the above nanopowder production apparatus, and in the production process, the arc sheath gas directly acts on the high-temperature core region caused by the arc, thereby directly reducing the concentration of vapor around the arc. This suppresses excessive collisions between atoms of the metal solid and reduces the possibility of a rapid increase in the particle size of nanoparticles.

[0019] Preferably, the arc current is 400 to 500 A.

[0020] Preferably, the arc voltage is 100 to 120V.

[0021] Preferably, the average temperature in the evaporation can is 550 to 600K.

[0022] Preferably, the arc sheath gas is obtained by mixing argon gas and hydrogen gas at a volume ratio of (8 to 10):1.

Advantages of the Invention

[0023] As described above, the present application has the following beneficial effects.

[0024] The nano powder manufacturing apparatus of the present application includes an arc sheath gas passage, a main sheath gas inlet, and an auxiliary sheath gas inlet. By introducing the arc sheath gas into the apparatus through the arc sheath gas passage and directly acting on the arc high-temperature core region, the concentration of vapor around the arc can be directly reduced, suppressing excessive collision between raw material atoms, reducing the possibility of a sharp increase in the particle size of the nano particles. By introducing the main sheath gas and the auxiliary sheath gas into the apparatus through the main sheath gas inlet and the auxiliary sheath gas inlet, the main sheath gas and the auxiliary sheath gas can be combined with the arc sheath gas to further reduce the concentration of the raw material vapor, while the formed nano powder can be blown into the cooling collection chamber. The combination of the three types of sheath gases enables the nano powder to have the advantages of high production yield and small particle size.

Brief Description of the Drawings

[0025] [Figure 1] It is a schematic configuration diagram of the nano powder manufacturing apparatus of the present application. [Figure 2] It is a schematic diagram of the internal structure of the arc generator according to Embodiment 1 of the present application. [Figure 3] It is a schematic diagram of the intake assembly according to Embodiment 2 of the present application. [Figure 4] It is an enlarged view of part A in FIG. 3. [Modes for carrying out the invention]

[0026] Currently, to improve the yield of nanopowder, the industry typically uses a method of increasing the arc current and inputting high energy. Increasing the arc current causes a large amount of raw material to evaporate in a short time, further increasing the vapor concentration. If the vapor becomes too saturated, collisions between atoms of the raw material become more intense, and the particle size of the nanopowder increases rapidly. Decreasing the arc current yields nanopowder with smaller particle sizes, but the yield of nanopowder decreases.

[0027] Based on the above circumstances, the applicant aims to find a method for producing small-particle nanopowder by thoroughly researching the manufacturing process and equipment for nanopowder, with the premise of improving yield. Initially, the applicant used a method in which a gas passage was installed in the container wall to introduce a cooling gas into the interior, lowering the average temperature of the evaporation chamber, expanding the temperature gradient, rapidly condensing the vapor, suppressing the vapor concentration, and compressing the particle size. While this has some effect, the effect of suppressing the vapor concentration is limited because the introduced gas avoids the high-temperature core region caused by the arc.

[0028] Based on this, the applicant has modified a nanopowder manufacturing apparatus to form an arc sheath gas passage in the arc generator. By introducing arc sheath gas into the apparatus through the arc sheath gas passage, the arc sheath gas directly acts on the high-temperature core region caused by the arc, directly reducing the concentration of vapor around the arc. This suppresses excessive collisions between raw material atoms and reduces the possibility of a rapid increase in nanoparticle size. Since the flow rate of the arc sheath gas can be adjusted and controlled according to the magnitude of the arc current, the nanopowder combines the advantages of high yield and small particle size.

[0029] Embodiment The present application will be explained in more detail below, with reference to Figures 1-4.

[0030] Embodiments of the present application disclose a nanopowder manufacturing apparatus.

[0031] Embodiment 1 As shown in Figure 1, the nanopowder manufacturing apparatus includes an evaporator 1, an arc generator 2, and a cooling collection chamber 3. The evaporator 1 is cylindrical in shape, with its axis horizontal and its ends cone-shaped. A supply pipe 4 is drilled into the evaporator 1. A main sheath gas inlet 6 is installed horizontally at one end of the evaporator 1, and an outlet 5 is installed horizontally at the other end. Four auxiliary sheath gas inlets 7 are further formed at the top of the evaporator 1 and are used in combination with the main sheath gas inlet 6. The evaporator 1 has a double-walled structure, with the inner layer filled with chilled water, forming a water-cooled intermediate layer 11 that protects the apparatus and reduces the possibility of the apparatus being damaged by high temperatures.

[0032] As shown in Figure 1, a crucible stand 8 is installed inside the evaporator 1, a crucible 9 is placed on the crucible stand 8, the crucible 9 holds the raw materials, and an auxiliary heating induction coil 10 is further installed on the outer wall to assist in heating, and as shown in Figures 1 and 2, an arc generator 2 is drilled into the top of the evaporator 1, one end of the arc generator 2 closer to the inside of the evaporator 1 extends to directly above the crucible 9, and an arc sheath gas passage 21 is formed in the arc generator 2, the arc sheath gas passage 21 is composed of an annular groove 212 and a strip-shaped passage 211, the annular groove 212 is formed at one end of the arc generator 2 located inside the evaporator 1, and the strip-shaped passage 211 is formed along the length of the arc generator 2, with one end communicating with the outside and the other end communicating with the annular groove 212. The arc generator 2 is further provided with a cooling water passage 22 to protect it. The cooling water passage 22 is installed along the length of the arc generator 2 and one end is open to the outside.

[0033] Embodiment 2 This embodiment differs from Embodiment 1 in the following respects. As shown in Figures 1, 3, and 4, the nanopowder manufacturing apparatus of this embodiment further includes an intake assembly 12, the intake assembly 12 includes an intake ring 13, the intake ring 13 is installed inside the evaporator 1 and located above the crucible 9, the nanopowder manufacturing apparatus further includes an intake pipe 14 whose exhaust end communicates with a cooling collection chamber 3, and a connecting pipe 15 that connects the intake ring 13 and the intake pipe 14, and five intake ports 16 are formed on the inner ring of the intake ring 13.

[0034] As shown in Figures 1, 3, and 4, two sealing frames 17 are installed inside the intake pipe 14 along the direction of airflow. A sealing gate 18 covering the opening of the sealing frame 17 is hinged to the side of the top of the sealing frame 17 away from the connecting pipe 15. A gas storage pipe 19 is connected between the two sealing gates 18 in the intake pipe 14. A sealing plug 20 is slidably installed inside the gas storage pipe 19. A cylinder 21 is installed at the end of the gas storage pipe 19 away from the intake pipe 14. The piston rod 22 of the cylinder 21 is drilled into the gas storage pipe 19 and fixedly connected to the sealing plug 20. A ventilation hole 23 is formed in the side wall of one end of the gas storage pipe 19 closest to the cylinder 21.

[0035] Example 1 The nanopowder manufacturing method carried out in the nanopowder manufacturing apparatus of Embodiment 1 is performed according to the following steps S1 to S3.

[0036] In S1, the nickel ingot raw material is placed in the crucible, the arc generator is adjusted to the specified height, the vacuum pump is started, and the pressure in the evaporator is set to 10 -4 The pressure is reduced to Pa(A), argon gas is introduced to restore the pressure to 0.06 MPa(A), and this process is repeated three times to ensure that the air in the evaporator is replaced with the inert gas, argon gas.

[0037] In S2, the arc generator's power supply is activated, an arc is generated between the arc generator and the raw material, the arc current is increased to 200A, and the height of the arc generator is adjusted so that the arc voltage is 40V. The nickel ingot, the main raw material, evaporates into steam due to the high temperature of the arc.

[0038] In step S3, sheath gas is introduced into the evaporator via the main sheath gas inlet, auxiliary sheath gas inlet, and arc sheath gas passage, and the arc sheath gas flow rate is adjusted according to the magnitude of the arc current. In this embodiment, the arc sheath gas flow rate is set to 100 cc / min. The flow rate of the main sheath gas is adjusted to 500 SLPM and the flow rate of the auxiliary sheath gas to 100 SLPM to ensure that the average temperature inside the evaporator is 500 K. Both the main sheath gas and the auxiliary sheath gas are pure argon gas, and the arc sheath gas is obtained by mixing argon gas and hydrogen gas in a volume ratio of 8:1. The metal vapor diffuses due to the arc sheath gas, reducing the concentration of vapor around the high-temperature arc core region. The blown-away metal vapor flows downward along the horizontal axis of the evaporator due to the blowing of the main sheath gas and auxiliary sheath gas, during which time the metal vapor gradually condenses to form nanometal powder, which enters the cooling collection chamber due to the action of the airflow.

[0039] Example 2 The nanopowder manufacturing method implemented in the nanopowder manufacturing apparatus of Embodiment 1 differs from Embodiment 1 in that the volume ratio of argon gas and hydrogen gas in the arc sheath gas is different, and in this embodiment, the volume ratio of argon gas to hydrogen gas is 10:1.

[0040] Example 3 The nanopowder manufacturing method implemented in the nanopowder manufacturing apparatus of Embodiment 1 differs from Embodiment 1 in that the volume ratio of argon gas to hydrogen gas in the arc sheath gas is different, and in this embodiment, the volume ratio of argon gas to hydrogen gas is 9:1.

[0041] Examples 4-5 The nanopowder manufacturing method implemented in the nanopowder manufacturing apparatus of Embodiment 1 differs from Embodiment 1 in that the arc current, arc voltage, arc sheath gas flow rate, main sheath gas flow rate, auxiliary sheath gas flow rate, and average temperature inside the evaporator are different, as specifically shown in Table 1 below.

[0042] [Table 1]

[0043] Example 6 The nanopowder manufacturing method, which differs from that of Example 4 in that it is carried out in the nanopowder manufacturing apparatus of Embodiment 2, is performed according to the following steps S1 to S3.

[0044] In S1, the nickel ingot raw material is placed in the crucible, the arc generator is adjusted to the specified height, the vacuum pump is started, and the pressure in the evaporator is set to 10 -4 The pressure is reduced to Pa(A), argon gas is introduced to restore the pressure to 0.06 MPa(A), and this process is repeated three times to ensure that the air in the evaporator is replaced with the inert gas, argon gas.

[0045] In S2, the arc generator's power supply is activated, an arc is generated between the arc generator and the raw material, the arc current is increased to 500A, and the height of the arc generator is adjusted so that the arc voltage is 120V. The nickel ingot, the main raw material, evaporates into steam due to the high temperature of the arc.

[0046] In S3, sheath gas is introduced into the evaporator via the main sheath gas inlet, auxiliary sheath gas inlet, and arc sheath gas passage, and the arc sheath gas flow rate is adjusted according to the magnitude of the arc current. In this embodiment, the arc sheath gas flow rate is set to 500 cc / min. The flow rate of the main sheath gas is adjusted to 1600 SLPM and the flow rate of the auxiliary sheath gas to 600 SLPM to ensure that the average temperature inside the evaporator is 600 K. Both the main sheath gas and the auxiliary sheath gas are pure argon gas, and the arc sheath gas is obtained by mixing argon gas and hydrogen gas in a volume ratio of 8:1. The metal vapor diffuses due to the arc sheath gas, reducing the concentration of vapor around the high-temperature arc core region. Some of the blown-away metal vapor flows downward along the horizontal axis of the evaporator due to the blowing of the main sheath gas and auxiliary sheath gas, during which time the metal vapor gradually condenses to form nanometal powder, which enters the cooling collection chamber due to the action of the airflow.

[0047] While the main sheath gas is being introduced, the intake assembly is activated, i.e., the cylinder is activated, which drives the sealing plug upward, creating negative pressure. A portion of the nanopowder around the intake ring (arc high-temperature core region) enters the intake ring through the intake port and then enters the intake pipe through the connecting pipe, which is located between the two sealing gates. When the cylinder is driven to move the sealing plug downward, the sealing gate closer to the connecting pipe closes, and the sealing gate further away from the connecting pipe opens. Due to the effect of air pressure, the nanopowder leaves the intake pipe through the sealing gate further away from the connecting pipe and enters the cooling collection chamber.

[0048] This embodiment is carried out in the nanopowder manufacturing apparatus of Embodiment 2, and by using an intake assembly, a main sheath gas, and an auxiliary sheath gas in combination, the nanopowder is accelerated to move away from the arc high-temperature core region and the particle growth of the nanopowder in the high-temperature core region is reduced.

[0049] Comparative Example Comparative Example 1 The nanopowder manufacturing method carried out in the nanopowder manufacturing apparatus of Embodiment 1 is similar to the operating steps of Example 5, but differs from Example 5 in that in step S3, only the main sheath gas and auxiliary sheath gas are introduced into the evaporator, and the arc sheath gas is not introduced.

[0050] Performance Test The yield of the nanopowder production methods in Examples 1-6 and Comparative Example 1, and the particle size of the nanopowder produced by these methods were detected and are specifically shown in Table 2 (Performance Tests) below.

[0051] [Table 2]

[0052] As can be seen from Table 2, the particle size of the nanopowder produced by the manufacturing method of the examples of this application is all less than 100 nm, thus meeting the requirements for use of nanopowder. Examples 4 and 5 have a much larger yield than Examples 1 and 3, and the particle size of the nanopowder is close to that of Examples 1 and 3. Examples 4 and 5 have a yield close to that of Comparative Example 1, but the particle size of the nanopowder produced in Examples 4 and 5 is much smaller than that of Comparative Example 1.

[0053] The reason for this is as follows: In the manufacturing process of Examples 4 and 5, the arc current is large, and the flow rate parameters of the arc sheath gas, main sheath gas, and auxiliary sheath gas are adjusted in combination to control the concentration of metal vapor, thereby reducing the concentration of metal vapor and suppressing excessive collisions of metal atoms. This prevents the particle size of the metal powder from becoming uncontrollably large, resulting in high yields and small particle size nanopowder. In contrast, in Comparative Example 1, no arc sheath gas is introduced, so the concentration of metal vapor is too high, causing excessive collisions of metal atoms and potentially leading to an even larger particle size of the nanopowder.

[0054] This invention enables the realization of different system functions by combining different sheath gas components and different sheath gas flow parameters, and can be adapted to the manufacturing needs of multiple types of nanopowder, including but not limited to nanocopper powder.

[0055] This specific embodiment is merely an explanatory description of the present application and does not limit it. A person skilled in the art may, after reading this specification, make modifications to this embodiment as necessary, without making any creative contribution, but such modifications will be protected under patent law as long as they are within the scope of the claims of this application. [Explanation of Symbols]

[0056] 1 Evaporator 2. Arc Generator 21 Arc Sheath Gas Passage 211 Strip-shaped passage 212 Annular groove 22 Cooling water passage 3. Cooling and Collection Room 4 Supply pipe 5 Outlet 6. Main sheath gas inlet 7. Auxiliary sheath gas inlet 8 Crucible stand 9 Crucible 10. Auxiliary heating induction coil 11 Water-cooled intermediate layer 12 Intake Assembly 13 Intake ring 14 Intake pipe 15 Communication pipe 16 Intake 17 Sealing Frame 18 Sealing Gate 19 Gas storage pipes 20 sealing plugs 21 Cylinders 22 Piston Rod 23 Ventilation holes

Claims

1. A method for producing nanopowder carried out in a nanopowder production apparatus, The nanopowder manufacturing apparatus includes an evaporator (1), an arc generator (2), and a cooling and collection chamber (3). The evaporator (1) has a supply pipe (4) drilled through it, and a main sheath gas inlet (6) and an outlet (5) are installed horizontally, the outlet (5) communicating with the cooling and collection chamber (3). The arc generator (2) is drilled at the top of the evaporator (1), a crucible (9) is installed inside the evaporator (1), the arc generator (2) is installed above the crucible (9), and an arc sheath gas passage (21) is formed in the arc generator (2), one end of which communicates with the inside of the evaporator (1), and the other end of which communicates with the outside. The nanopowder manufacturing apparatus further includes an intake assembly (12), the intake assembly (12) includes an intake ring (13) installed inside the evaporator (1), an intake pipe (14) whose exhaust end communicates with a cooling collection chamber (3), and a connecting pipe (15) connecting the intake ring (13) and the intake pipe (14), the intake ring (13) being located above the crucible (9), a plurality of intake ports (16) being installed on the inner ring of the intake ring (13), and two sealing frames (17) being installed inside the intake pipe (14) along the direction of airflow, each of the sealing A sealing gate (18) is hinged to the side of the top of the retaining frame (17) away from the connecting pipe (15), the sealing gate (18) covers the opening of the sealing frame (17), a gas storage pipe (19) is connected between the two sealing gates (18) within the intake pipe (14), a sealing plug (20) is slidably installed inside the gas storage pipe (19), a cylinder is installed at the end of the gas storage pipe (19) away from the intake pipe (14), the piston rod (22) of the cylinder is drilled into the gas storage pipe (19) and connected to the sealing plug (20), The aforementioned nanopowder production method is Step S1 involves placing a metal solid in a crucible (9) and replacing the air in the evaporator (1) with an inert gas. Step S2 involves starting the power supply of the arc generator (2), adjusting the arc current to 200-500A so that the arc voltage is 40-120V, and adjusting the height of the arc generator (2), so that the metal solid evaporates into vapor due to the high temperature action of the arc. Depending on the magnitude of the arc current, an arc sheath gas with a flow rate of 100 to 500 cc / min is introduced into the evaporator (1), and a main sheath gas with a flow rate of 500 to 1600 SLPM is introduced into the evaporator (1) to ensure that the average temperature inside the evaporator (1) is 500 to 600 K. Vapor is blown in with the arc sheath gas and the main sheath gas to diffuse it as nanopowder, the nanopowder is mixed with the main sheath gas and sent out of the evaporator (1) through the outlet (5) to obtain nanopowder with a particle size of 65 to 90 nm, and the cylinder is started while the main sheath gas is being introduced. A method for producing nanopowder, characterized by comprising step S3, where a cylinder is driven so that the sealing plug moves upward, creating negative pressure, and a portion of the nanopowder in the arc high-temperature core region around the intake ring enters the intake ring through the intake port and further enters the intake pipe through the connecting pipe, located between two sealing gates, and when the cylinder is driven so that the sealing plug moves downward, the sealing gate closer to the connecting pipe closes and the sealing gate further away from the connecting pipe opens, and due to the action of air pressure, the nanopowder leaves the intake pipe through the sealing gate further away from the connecting pipe and enters the cooling collection chamber.

2. The nanopowder manufacturing method according to claim 1, characterized in that an auxiliary sheath gas inlet (7) is further formed at the top of the evaporator (1).

3. The nanopowder manufacturing method according to claim 1, characterized in that an annular groove (212) is formed at one end located inside the evaporator (1) of the arc generator (2), a strip-shaped passage (211) is formed in the arc generator (2) along its own longitudinal direction, one end of the strip-shaped passage (211) is in communication with the outside and the other end is in communication with the annular groove (212), and the annular groove (212) and the strip-shaped passage (211) together constitute an arc sheath gas passage (21).

4. The method for producing nanopowder according to claim 1, characterized in that the arc current is 400 to 500 A.

5. The nanopowder manufacturing method according to claim 1, characterized in that the arc voltage is 100 to 120 V.

6. The nanopowder production method according to claim 1, characterized in that the average temperature inside the evaporator is 550 to 600 K.

7. The method for producing nanopowder according to claim 1, characterized in that the arc sheath gas is obtained by mixing argon gas and hydrogen gas in a volume ratio of (8 to 10):1.

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