JP6890291B2 - Fine particle manufacturing equipment and manufacturing method - Google Patents

Description

The present invention relates to a fine particle manufacturing apparatus and a fine particle manufacturing method used, for example, as a coating material for an electrode material of a lithium ion battery or a film material for food packaging, or an ink raw material used for wiring of electronic devices. is there.

In recent years, nanometer-order fine particles have been studied for application to various devices. For example, nickel metal fine particles are currently used in ceramic capacitors, and the use of fine particles having a particle size of 200 nanometers or less and good dispersibility is being studied for next-generation ceramic capacitors.

_{Further, fine particles of silicon monoxide (SiO x} : x = 1 to 1.6) having a lower oxygen content than silicon dioxide are utilized as an antireflection film for an optical lens or a vapor deposition material for a gas barrier film for food packaging. There is. Recently, it is expected to be applied to negative electrode materials of lithium ion secondary batteries.

As a general method for producing these nanometer-order fine particles, a bulk material as a raw material is introduced together with beads such as ceramic or zirconia, and the material is made into fine particles by mechanical pulverization, or the material is melted and There are a method of evaporating and injecting into air or water to obtain fine particles, or a method of chemically obtaining fine particles such as electrolysis or reduction. Among them, the method of producing fine particles in the gas phase using thermal plasma (about 10000 ° C.) such as high-frequency plasma or arc plasma has few impurities (contamination) and excellent dispersibility of the produced fine particles. It is very useful from the viewpoint that it is easy to synthesize composite fine particles made of the above kinds of materials (see, for example, Patent Document 1).

FIG. 4 shows a schematic cross-sectional view of a fine particle manufacturing apparatus using the thermal plasma of Conventional Example 1.
The powder generator 101 is a hollow body, and is roughly divided into a fine mist introduction section 201, a fine mist storage section 202, and a reaction section 203. The fine mist introduction section 201 is provided on the lower side of the powder generator 101 toward the fine mist storage section 202, and a tubular reaction section 203 continues above the fine mist storage section 202. The upper end of the reaction unit 203 is connected to the suction machine 206 via the duct 208, the powder collecting unit 204, and the duct 207. The powder collecting unit 204 has a built-in filter member for separating fine particles and gas, for example, a bug filter 205. The suction machine 206 sucks the inside of the powder generator 101 through the duct 207, the bag filter 205 in the powder collecting unit 204, and the duct 208, and discharges the gas that has passed through the bag filter 205 to the outside. It is provided in. The reaction unit 203 has a group of electrodes 210, and these electrodes 210 convert a three-phase alternating current supplied from a commercial power source into a polyphase alternating current via a plurality of single-phase transformers. It is connected to each of the secondary terminals of each phase of the device 211 in a one-to-one relationship. Further, the tip portions of the electrodes 210 are positioned evenly at a distance around the axis of the reaction portion 203, and are arranged so that the phase differences between the adjacent tip portions are equal to each other, and are arranged between the electrodes 210. The plasma 212 is formed. By passing the fine mist through the plasma 212, the particles are made into fine particles and can be collected by the bug filter 205 of the powder collecting unit 204.

Further, in the conventional example 2, when the particles are made into fine particles using the thermal plasma, the gas is supplied to the tail flame of the thermal plasma to quench the particles, so that fine particles having a uniform particle size can be formed.

Japanese Unexamined Patent Publication No. 2004-263257 Japanese Unexamined Patent Publication No. 2006-247446

In the conventional fine particle manufacturing apparatus described above (see Patent Document 1), the plasma area can be expanded by increasing the distance between the electrodes, and a large amount of fine particles can be generated. On the other hand, when the area of the plasma becomes large, the outer peripheral portion can be cooled, but the central portion can be cooled by simply flowing the cooling gas in the flow direction of the plasma as in the conventional fine particle manufacturing method (see Patent Document 2) described above. Can not. Therefore, fine particles with insufficient cooling are generated, and the variation in particle size becomes large.
An object of the present invention is to provide a fine particle manufacturing apparatus and a fine particle manufacturing method capable of controlling the particle size even with a large-area plasma in consideration of the above-mentioned conventional problems.

In order to achieve the above object, the fine particle production apparatus according to one aspect of the present invention may be used.
With a vacuum chamber
A material supply device connected to one end side of the vacuum chamber to supply material particles into the vacuum chamber from a material supply port,
A plurality of electrodes arranged in the middle portion of the vacuum chamber to generate plasma in the vacuum chamber,
The material supply device is connected to the other end of the vacuum chamber and has a collection unit for collecting fine particles discharged from the discharge port of the vacuum chamber, and the plasma generated in the vacuum chamber is used. An apparatus for producing the fine particles from the supplied particles of the material.
The material supply port is provided below the center position of the plurality of electrodes in the vertical direction.
The material supply device has a gas supply pipe for supplying gas for controlling the flow of particles of the material and the fine particles from the lower side in the vertical direction to the upper side in the vertical direction from the material supply port.
As the particles of the material pass through the region of the plasma, they evaporate or vaporize to give the material gas.
Oite between the electrode and the discharge port for jetting angle vertically upward direction, 75 ° or 150 ° to der Li Kui cooling gas portion collides with the central portion of the plasma is lower or less A plurality of stages of gas introduction ports having a gas introduction port for cooling the central gas, which is at least one stage of gas introduction port for introducing the cooling gas that flows and cools the material gas that has flowed out of the center of the plasma, is described. Provided near the electrode
In the plurality of stages of gas inlets, the ejection angle is 15 ° or more and 90 ° or less and the cooling gas is different from the central gas cooling gas inlet having the ejection angle. A gas introduction port for cooling the side gas, which is another gas introduction port for introducing the cooling gas that flows diagonally upward and cools the material gas that has escaped from the side surface of the plasma, is provided.
In the multi-stage gas introduction port, the cooling gas for cooling the material gas whose ejection angle is 75 ° or more and 150 ° or less and has escaped from the center of the plasma with respect to the vertically upward direction is introduced. The cooling for cooling the material gas whose ejection angle is 15 ° or more and 90 ° or less and has escaped from the side surface of the plasma from the gas introduction port for cooling the central gas. the side gas inlet for the gas cooling of introducing gas, that is installed on a side close to the electrode.
In order to achieve the above object, the method for producing fine particles according to another aspect of the present invention is:
Thermal plasma is generated in the vacuum chamber by applying a voltage to a plurality of electrodes installed in the middle part of the vacuum chamber.
The particles of the material supplied into the vacuum chamber from the material supply port provided on the lower side in the vertical direction from the center positions of the plurality of electrodes are from the lower side in the vertical direction to the vertical direction from the material supply port. As it passes through the region of the thermal plasma by a gas that controls the flow of particles of the material upwards , it evaporates or vaporizes into the material gas.
Further, in between the electrode and the vacuum chamber of the outlet, of the gas inlet of the plurality of stages that are provided in the vicinity of the electrode, with respect to the vertical upward direction is ejected angle at 75 ° or 150 ° or less A part of the cooling gas introduced from the gas inlet for cooling the central gas, which is at least one stage of the gas inlet, collides with the central portion of the plasma, and a part of the cooling gas flows downward to the center of the thermal plasma. It is sprayed on the material gas at the moment when it comes out of the area of the part,
The ejection angle is vertically upward, which is different from the central gas cooling gas inlet which is installed closer to the electrode and has the ejection angle from the central gas cooling gas inlet. The cooling gas introduced from the gas inlet for cooling the side gas, which is 15 ° or more and 90 ° or less, flows diagonally upward and is sprayed on the material gas at the moment when it escapes from the side region of the thermal plasma. al is, the material gas to generate a sudden Refrigerated microparticles.

According to the above aspect of the present invention, a material in which gas is introduced from a gas inlet having an ejection angle of 75 ° or more and 150 ° or less with respect to the flow direction of plasma for cooling at least the central portion of plasma and evaporated by plasma. By cooling, the entire surface can be uniformly cooled even with a large area of plasma. Therefore, it is possible to provide a fine particle production apparatus and a fine particle production method capable of producing a large amount of particles having a uniform size and producing high quality fine particles at low cost.

Schematic longitudinal sectional view of the fine particle manufacturing apparatus of the first embodiment of the present invention. Schematic longitudinal sectional view around the plasma of the fine particle manufacturing apparatus of the first embodiment of the present invention. Process flow according to the first embodiment of the present invention Schematic longitudinal sectional view of the fine particle manufacturing apparatus of Conventional Example 1.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First Embodiment)
FIG. 1 shows a schematic vertical cross-sectional view of the fine particle manufacturing apparatus according to the first embodiment. FIG. 2 shows a schematic vertical cross-sectional view around the plasma of the fine particle manufacturing apparatus according to the first embodiment. FIG. 3 shows the process flow in the first embodiment. As an example, an example of producing nanometer-order fine particles of silicon will be described with reference to FIGS. 1 to 3.

The fine particle production apparatus according to the first embodiment includes at least a reaction chamber 1 as an example of a vacuum chamber, a material supply apparatus 10, and electrodes for generating plasma, for example, a plurality of electrodes 4 and the generated fine particles 32. It is configured to include a fine particle collecting unit 3 as an example of a collecting unit to be collected.

The material supply device 10 is arranged below the bottom of the reaction chamber 1 and supplies the material particles 30 upward into the reaction chamber 1.

The fine particle collection unit 3 is arranged so as to be connected to the discharge port 17 at the upper end of the reaction chamber 1, is exhausted by the pump 22 through the pipe 20, and collects the fine particles 32 generated in the reaction chamber 1. The plurality of electrodes 4 are arranged on the side portion of the central portion of the reaction chamber 1 at predetermined intervals so that the tips protrude inside, and heat plasma 31 is generated in the reaction chamber 1 to generate heat. Fine particles 32 are produced from the material particles 30 supplied from the material supply device 10 by the plasma 31.

N (n is an integer of 2 or more) AC power supplies 5 that supply powers having different phases to the plurality of electrodes 4, specifically, the first AC power supply 5-1 and the second AC power supply 5-1. The power supply 5-2, the third AC power supply 5-3, ..., The nth AC power supply 5-n are connected, and for example, six 60 Hz AC voltages with the phases shifted by 60 ° are applied from the AC power supply 5. Can be applied to each of the electrodes 4 of. Each electrode 4 is independently movable in the radial direction with respect to the center of the reaction chamber 1 by an electrode driving device 4a composed of a motor or the like.

More specifically, in the first embodiment, the fine particle manufacturing apparatus controls the material supply pipe 11 connecting the material supply apparatus 10 and the reaction chamber 1, the charged material particles 30, and the flow of the generated fine particles. A gas supply pipe 14 for supplying gas is provided in the reaction chamber 1.

The material supply device 10 is connected to the reaction chamber 1 by the material supply pipe 11, and supplies the material particles 30 from the material supply device 10 into the reaction chamber 1 from the bottom side of the reaction chamber 1. The material supply pipe 11 extends vertically upward from the bottom to the vicinity of the central portion of the material supply device 10 and is erected. A plurality of lower gas supply pipes 14 are arranged from the bottom of the material supply device 10 along the longitudinal direction (in other words, along the vertical direction) of the material supply pipe 11 in the vicinity of the material supply pipe 11, and are arranged in the vicinity of the material supply pipe 11. Gas can be supplied from the lower side in the vertical direction to the upper side in the vertical direction.

As shown in FIG. 2, upper first and second gas supply pipes 15 and 16 are provided as examples of gas introduction ports above the portion where plasma 31 is generated around the plurality of electrodes 4.

The upper first gas supply pipe 15 installed on the electrode side sends gas from the periphery of the side surface of the plasma 31 toward the center at a first angle α1 of 15 ° or more and 90 ° or less with respect to the vertically upward direction. It is possible to supply. When the first angle α1 is smaller than 15 °, the gas does not sufficiently hit the side surface of the plasma 31 and flows vertically upward. Further, when the first angle α1 is larger than 90 °, the gas hits the lower part of the plasma 31 particle formation interface, so that the cooling becomes insufficient.

Further, the upper second gas supply pipe 16 installed on the discharge port 17 side is centered at a second angle α2 of 75 ° or more and 150 ° or less with respect to the vertically upward direction from the periphery of the upper part of the plasma 31. It is possible to supply gas to the target. When the second angle α2 is smaller than 75 °, the gas flow in the vertically upward direction becomes large, and the gas flow in the vertical downward direction from the upper part of the plasma 31 toward the center of the plasma 31 becomes small. Further, when the second angle α2 is larger than 150 °, the distance to the central portion of the plasma 31 becomes large, so that the gas does not reach the central portion of the plasma 31 and the cooling becomes insufficient.

Hereinafter, the manufacturing operation of the fine particle manufacturing apparatus will be described along with the process flow of FIG.
(Step S1) Material installation and evacuation are performed.
First, the material particles 30 are installed in the material supply device 10, and the inside of the reaction chamber 1, the fine particle recovery unit 3, and the material supply device 10 are exhausted by the pump 22 to, for example, several tens of Pa. Reduce the effects of atmospheric oxygen.

(Step S2) Gas introduction and pressure adjustment are performed.
Next, gas is supplied from the plurality of gas supply devices 27 to the material supply device 10, the lower gas supply pipe 14, and the upper first and second gas supply pipes 15 and 16 via the flow rate regulator 26, respectively. Is supplied while adjusting the flow rate, and is supplied into the reaction chamber 1 from those devices or tubes 10, 14, 15, 16. The gas supplied into the reaction chamber 1 is adjusted to a predetermined pressure by the pressure adjusting valve 21 attached to the front stage of the pump 22. Further, although not shown, it is possible to allow gas to flow inside the plurality of electrodes 4.

In the first embodiment of the first embodiment, in order to produce fine particles of silicon as an example, gas is introduced into the reaction chamber 1 from the gas supply device 27 via three gas supply pipes 14, 15 and 16. As an example, argon is supplied, and the inside of the reaction chamber 1 is maintained at a pressure near the atmospheric pressure in an inert gas atmosphere of argon, and the following fine particle production step is performed. In order to promote the reduction of the material, hydrogen gas and a trace amount of carbonized gas are introduced into the reaction chamber 1 from the gas supply device 27 via the gas supply pipes 14, 15, 16 and the electrode 4 as another example of the gas. It may be mixed and introduced.

(Step S3) Discharge is started.
Here, before explaining the discharge start operation, the electrode 4 for generating the thermal plasma 31 is made of a carbon material as an example, and the tip thereof is in the reaction chamber 1 in the lateral direction (for example, 0 to 30 ° upward with respect to the horizontal direction). Six electrodes 4 are radially arranged on the circumferential wall of the reaction chamber 1 at intervals of 60 ° around the central axis of the reaction chamber 1 in a protruding state. In order to reduce the evaporation of the electrode material, water cooling and cooling gas, which are not specifically shown, are allowed to flow inside each electrode 4 to cool the electrodes.

In the first embodiment, the six electrodes 4 are arranged radially, but if the number of electrodes is a multiple of 6, the number of electrodes is increased or not only arranged in the same plane, but also in two stages. Alternatively, the electrodes may be arranged in multiple stages such as three stages (in other words, at different positions along the longitudinal direction (that is, the axial direction) of the reaction chamber 1). By arranging the electrodes 4 in multiple stages, the thermal plasma 31 which is a heat source for evaporating the material can be further expanded in the vertical direction, which is advantageous for generating a large amount of fine particles. Further, although a carbon material is used as an example of the material of the electrode 4, an electrode composed of a refractory metal such as tungsten or tantalum may be used.

In the discharge start operation in step S3, as shown in FIG. 1, when the thermal plasma 31 is ignited, two arbitrary electrodes 4 are moved to the center side of the reaction chamber 1 by the electrode driving device 4a, and then an alternating current is generated. A voltage is applied from the AC power source 5 to each of the two electrodes 4.

Next, after the thermal plasma 31 is ignited, the electrodes 4 are arranged in the radial direction (direction toward the outside from the center position of the radially arranged electrodes 4) while adjusting the current applied to the electrodes 4 to be constant. It is moved by the electrode driving device 4a and kept away from the center position of the electrode 4 until the tip of the electrode 4 reaches a predetermined position. As a result, for example, the area of the thermal plasma at about 10000 ° C. becomes large, and the processing amount can be increased. As an example, each electrode driving device 4a uses the input electric power to rotate the ball screw in the forward and reverse directions by a motor to advance and retreat the electrode 4 connected to the nut member screwed to the ball screw in the axial direction.

At that time, if the distance between the opposing electrodes 4 is smaller than 50 mm, the discharge area is small, so that the processing amount is not sufficient, and if it is larger than 500 mm, the discharge cannot be maintained between the opposing electrodes 4. Therefore, the distance between the opposing electrodes is preferably 50 mm or more and 500 mm or less.

(Step S4) Material supply is started.
Then, the supply of the material particles 30 is started together with the gas.
As an example, the material particles 30 which are the raw materials of the fine particles 32 are made of silicon powder having a size of about 16 microns and installed in the material supply device 10. In the first embodiment, 16 micron particles were used, but if the particle size is larger than 1 micron and 100 microns or less, depending on the conditions of the thermal plasma 31, the particles are vaporized by the thermal plasma 31 and nanometered. It is possible to produce micron particles 32 on the order of meters. If the material particles 30 having a particle size larger than 100 microns are used, the material particles 30 cannot be completely evaporated, and the resulting fine particles 32 may become large. As the material supply device 10, as an example, a local flow type powder supply device can be used. In this local flow type powder supply device, the supply amount of the material particles 30 is controlled by the flow rate of the carrier gas and the rotation speed of the device into which the material particles 30 are introduced, and the material particles 30 which are powder materials are distributed at a constant ratio. Can be sent to the material supply pipe 11. As another example of the material supply device 10, a surface copying type powder feeder that controls the distance between the surface of the powder material and the nozzle using a laser or the like, or a hopper or the like is used to supply a fixed amount of the powder material to the groove. There is a quantitative powder feeder that sucks in. Any type of powder material supply device may be used, but it is used properly depending on the amount of powder material to be supplied.

(Step S5) Fine particles are formed.
Then, as shown in FIG. 1, the material particles 30 are sent from the material supply device 10 together with the gas to the material supply pipe 11, and are introduced together with the gas from the material supply port 12 at the upper end of the material supply pipe 11 into the reaction chamber 1. To. Around the material supply pipe 11, a plurality of lower gas supply pipes 14 for sending the material particles 30 or the fine particles 32 generated by the thermal plasma 31 in a certain direction (upward in the vertical direction) are provided, and the lower side is provided. Atmospheric gas is supplied from the gas supply pipe 14 of the above in the fixed direction (upward in the vertical direction). The material supply pipe 11 and the material supply port 12 are installed below the center positions of the plurality of electrodes 4 in the vertical direction. The lower gas supply pipe 14 is installed below the upper end of the material supply port 12 in the vertical direction. In particular, the upper end of the material supply port 12 is arranged so as to be located below the region of the thermal plasma 31. Further, the material particles 30 introduced together with the gas into the reaction chamber 1 evaporate or vaporize (hereinafter, typically referred to as "evaporation") when passing through the region of the thermal plasma 31, and the material particles. 30 is gasified.

The material gas formed by evaporating the material particles 30 rises in the reaction chamber 1 and exits from the region of the thermal plasma 31 due to the updraft due to the heat of the thermal plasma 31 or the gas flow from the gas supply pipe 14 or the electrode 4. Then, at the moment when the material gas exits the region, the material gas is rapidly cooled by the sprayed gas, and spherical fine particles 32 are generated. In the first embodiment, since the gas flows diagonally upward from the upper first gas supply pipe 15 on the side surface of the thermal plasma 31, the cooling rate of the material gas released from the side surface of the thermal plasma 31 can be further increased. .. Further, a cooling gas is flowed from the upper second gas supply pipe 16 toward the center perpendicular to the vertically upward direction on the upper part of the thermal plasma 31, and the cooling gas collides with the central portion of the thermal plasma 31. A part of the material gas flows downward, and the cooling rate of the material gas released from the central portion of the thermal plasma 31 can be further increased. The ejection angle of the gas flowing from the upper second gas supply pipe 16 may collide at the central portion and a part of the gas may flow downward, and the ejection angle (that is, the second angle α2) is 75 ° or more and 150 °. It is possible. By the cooling gas from the gas supply pipes 15 and 16 on the upper side, the material gas that has escaped from the region of the thermal plasma 31 can be uniformly cooled even in the thermal plasma 31 having a large area, and the particle size can be controlled with high accuracy.

Further, various cases may be considered depending on the area of the thermal plasma 31, the gas flow rate of the lower gas supply pipe 14, or the gas flow that changes due to the addition of the inner chamber or the like, but it is desirable that the upper first gas supply pipe 15 is used. By increasing the flow velocity of the gas ejected from the upper second gas supply pipe 16, the cooling gas from the upper second gas supply pipe 16 can easily reach the central part of the thermal plasma 31, and the cooling effect can be further improved. It gets higher. The gas flow rate can be controlled by the gas flow rate or the shape, size, number, etc. of the gas supply pipe openings.

Further, the installation positions of the first and second gas supply pipes 15 and 16 on the upper side may vary depending on the area of the thermal plasma 31 and the gas flow rate of the gas supply pipe 14, or the gas flow that changes due to the addition of the inner chamber or the like. Can be considered.

Further, by regularly changing the flow velocity of the gas supplied from the plurality of gas supply ports of the gas supply pipe 16 in the circumferential direction for each gas supply port by the flow rate regulator 26, the gas collision position and the position to flow downward perpendicularly to the gas collision position are obtained. Can be changed regularly, and the cooling effect can be further enhanced.

Further, the area of the cooling surface of the plasma 31 in which the fine particles 32 are generated is increased by deforming the upper part of the plasma 31 in a wavy shape due to the downward flow of the gas introduced from the gas supply port of the gas supply pipe 16. It becomes larger than the area of the cooling surface of the plasma of the above, and the amount of fine particles 32 produced can be increased.

Further, in general, in the plasma 31 at the place where the material particles 30 are supplied, the heat of the plasma is taken away by the evaporation of the material particles 30, so that the temperature of the plasma at the place where the material particles 30 are evaporated drops. Conventionally, when the material particles 30 are continuously charged into a continuous discharge such as a general inductively coupled plasma (ICP) torch, the temperature of the plasma drops due to the evaporation of the material particles 30, and the material particles 30 are completely discharged. There is also a problem that the particle size distribution is deteriorated because relatively large fine particles are generated because the plasma cannot be evaporated. Further, in order to produce fine particles 32 having a desired particle size or to improve the particle size distribution of the produced fine particles 32, there is no choice but to limit the input amount of the material particles 30, and the processing amount is reduced. There were also challenges.

On the other hand, the plasma 31 generated by the plurality of electrodes 4 used in the first embodiment has a plurality of electrodes of an AC power source 5 capable of supplying electric power having different phases, for example, 60 Hz power having a phase shift of 60 °. It is used as the power source of 4. Therefore, the discharge is in the form of a pulse, and a high-temperature thermal plasma 31 can always be generated.

(Step S6) The discharge is stopped and the fine particles are collected.
Next, as shown in FIG. 1, the fine particles 32 generated by the plasma 31 are recovered by the fine particle recovery unit 3 by the flow of gas from the gas supply pipes 14, 15 and 16. Although not shown, a cyclone capable of classifying an arbitrary fine particle diameter or larger and a bug filter capable of collecting desired fine particles are attached to the fine particle collecting unit 3. Since the bug filter for collecting fine particles circulates a high-temperature gas, a filter using silica fiber having high heat resistance can be used as an example. In addition, when the recovered fine particles are taken out to the atmosphere, there is a risk of ignition, so they are left in an atmosphere containing about 1% of the atmosphere (gas containing oxygen) for several hours, undergoing slow oxidation treatment, and then placed in the atmosphere. Take it out. As a result, the surface of the silicon fine particles is oxidized, for example, by about 1 to 2 nanometers, and can be safely taken out. By these above-mentioned processes, silicon fine particles of, for example, 10 to 300 nanometers can be recovered from the bag filter.

In the first embodiment, a method for producing nanometer-order fine particles of silicon (Si) has been described, but a metal such as nickel (Ni), silver (Ag) or copper (Cu), or glass (SiO ₂ ) , Silicon nitride (SiN), or _{an inorganic material such as alumina (Al 2} O ₃ ) may be used as a material for producing fine particles to generate fine particles. Further, by reacting with the gas introduced into the reaction chamber 1, for example, using a silicon material, silicon monoxide (SiO _x : x = 1 to 1.6) and silicon nitride (SiN _x : x = 0.1). ~ 1.3), or _{fine particles of silicon carbide (SiC x} ) may be produced. Furthermore, it can also be used to generate a composite material composed of a plurality of materials having a silicon core on the inside and being covered with alumina, silicon carbide, or the like on the outside.

According to the first embodiment, at least a gas having an ejection angle of 75 ° or more and 150 ° or less (that is, a second angle α2) with respect to the flow direction of the plasma 31 for cooling the central portion of the plasma 31. By introducing gas from the second gas supply pipe 16 in the example of the introduction port and cooling the material evaporated by the plasma 31, the entire surface of the plasma 31 having a large area can be uniformly cooled. Therefore, it is possible to provide a fine particle production apparatus and a fine particle production method capable of producing a large amount of fine particles 32 having a uniform size and producing high quality fine particles 32 at low cost.

Further, according to the first embodiment, a gas having an ejection angle (that is, a first angle α1) of 15 ° or more and 90 ° or less with respect to the flow direction of the plasma 31 for cooling the outer peripheral portion of the plasma 31. By introducing gas from the first gas supply pipe 15 of the example of the introduction port and cooling the material evaporated by the plasma 31, the gas sufficiently hits the side surface of the plasma 31 and the plasma 31 can be cooled efficiently and sufficiently.

Further, according to the first embodiment, since the AC power source 5 can be connected to each of the plurality of electrodes 4 to generate the plasma 31, the thermal plasma 31 that evaporates the material particles 30 is compared with other methods. The area of the plasma can be increased and a large amount of material can be processed.

The present invention is not limited to the first embodiment, and can be implemented in various other embodiments. For example, the shape of each of the gas supply pipes 15 and 16 or the number of supply ports may be various shapes or the number of ports. For example, by changing the inner diameter by adding an inner chamber in the reaction chamber 1, the flow velocity of the gas or plasma 31 can be changed, and the cooling gas can efficiently reach the plasma 31.

By appropriately combining any of the various embodiments or modifications, the effects of each can be achieved. Further, it is possible to combine embodiments or examples, or to combine embodiments and examples, and it is also possible to combine features in different embodiments or examples.

The fine particle manufacturing apparatus and fine particle manufacturing method according to the above aspect of the present invention can efficiently process a large amount of material by suppressing exhaust heat from plasma, increase the amount of fine particles produced, and produce at low cost. can do. Therefore, the present invention is useful as a fine particle manufacturing apparatus and a fine particle manufacturing method used in a device for which mass production is required, such as a lithium ion secondary battery or a ceramic capacitor.

1 Reaction chamber 3 Fine particle recovery unit 4 Electrode 5 AC power supply 5-1, 5-2, 5-3, ..., 5-n 1st, 2nd, 3rd, ..., nth AC power supply 10 Material Supply device 11 Material supply pipe 12 Material supply port 14 Lower gas supply pipe 15 Upper first gas supply pipe 16 Upper second gas supply pipe 17 Outlet 20 Pipe 21 Pressure adjustment valve 22 Circulation pump 26 Flow regulator 27 Gas supply device 30 Material particles 31 Plasma 32 Fine particles α1 First angle α2 Second angle

Claims (9)

With a vacuum chamber
A material supply device connected to one end side of the vacuum chamber to supply material particles into the vacuum chamber from a material supply port,
A plurality of electrodes arranged in the middle portion of the vacuum chamber to generate plasma in the vacuum chamber,
The material supply device is connected to the other end of the vacuum chamber and has a collection unit for collecting fine particles discharged from the discharge port of the vacuum chamber, and the plasma generated in the vacuum chamber is used. An apparatus for producing the fine particles from the supplied particles of the material.
The material supply port is provided below the center position of the plurality of electrodes in the vertical direction.
The material supply device has a gas supply pipe for supplying gas for controlling the flow of particles of the material and the fine particles from the lower side in the vertical direction to the upper side in the vertical direction from the material supply port.
As the particles of the material pass through the region of the plasma, they evaporate or vaporize to give the material gas.
Oite between the electrode and the discharge port for jetting angle vertically upward direction, 75 ° or 150 ° to der Li Kui cooling gas portion collides with the central portion of the plasma is lower or less A plurality of stages of gas introduction ports having a gas introduction port for cooling the central gas, which is at least one stage of gas introduction port for introducing the cooling gas that flows and cools the material gas that has flowed out of the center of the plasma, is described. Provided near the electrode
In the plurality of stages of gas inlets, the ejection angle is 15 ° or more and 90 ° or less and the cooling gas is different from the central gas cooling gas inlet having the ejection angle. A gas introduction port for cooling the side gas, which is another gas introduction port for introducing the cooling gas that flows diagonally upward and cools the material gas that has escaped from the side surface of the plasma, is provided.
In the multi-stage gas introduction port, the cooling gas for cooling the material gas whose ejection angle is 75 ° or more and 150 ° or less and has escaped from the center of the plasma with respect to the vertically upward direction is introduced. The cooling for cooling the material gas whose ejection angle is 15 ° or more and 90 ° or less and has escaped from the side surface of the plasma from the gas introduction port for cooling the central gas. the side gas inlet for the gas cooling of introducing gas, that are placed closer to the electrode, particulate manufacturing equipment. The more the flow rate of the gas introduced from the gas inlet for the side gas cooling of a plurality of stages of the gas inlet, the high flow rate of gas introduced from the center gas inlet for gas cooling, in claim 1 The fine particle production apparatus according to the above. The fine particle production according to claim 1 or 2 , further comprising a plurality of gas introduction ports for cooling the central gas and a flow rate regulator for regularly changing the flow rate of the gas introduced from each location. apparatus. The fine particle manufacturing apparatus according to any one of claims 1 to 3 , wherein the upper part of the plasma is deformed in a wavy shape due to a downward flow of gas introduced from the gas inlet for cooling the central gas. .. The electrode according to any one of claims 1 to 4 , wherein the electrode for generating plasma is a plurality of electrodes arranged in the vacuum chamber and having a tip protruding into the vacuum chamber to generate the plasma. Fine particle production equipment. Further equipped with an AC power supply connected to each of the plurality of electrodes and supplying power having a different phase, respectively.
The fine particle manufacturing apparatus according to any one of claims 1 to 5 , wherein electric power having a different phase is supplied from the AC power source to each of the plurality of electrodes to generate the plasma to generate the plasma. .. The fine particle manufacturing apparatus according to any one of claims 1 to 6 , wherein in the plurality of electrodes, the distance between the opposing electrodes is 50 mm or more and 500 mm or less. Thermal plasma is generated in the vacuum chamber by applying a voltage to a plurality of electrodes installed in the middle part of the vacuum chamber.
The particles of the material supplied into the vacuum chamber from the material supply port provided on the lower side in the vertical direction from the center positions of the plurality of electrodes are from the lower side in the vertical direction to the vertical direction from the material supply port. As it passes through the region of the thermal plasma by a gas that controls the flow of particles of the material upwards , it evaporates or vaporizes into the material gas.
Further, in between the electrode and the vacuum chamber of the outlet, of the gas inlet of the plurality of stages that are provided in the vicinity of the electrode, with respect to the vertical upward direction is ejected angle at 75 ° or 150 ° or less A part of the cooling gas introduced from the gas inlet for cooling the central gas, which is at least one stage of the gas inlet, collides with the central portion of the plasma, and a part of the cooling gas flows downward to the center of the thermal plasma. It is sprayed on the material gas at the moment when it comes out of the area of the part,
With respect to the vertical upward direction, the ejection angle is different from the central gas cooling gas inlet, which is installed closer to the electrode and has the ejection angle from the central gas cooling gas inlet. The cooling gas introduced from the gas inlet for cooling the side gas, which is 15 ° or more and 90 ° or less, flows diagonally upward and is sprayed on the material gas at the moment when it escapes from the side region of the thermal plasma. al is, the material gas is cooled rapidly to produce a fine, particle production method. The eighth aspect of the present invention, wherein when the thermal plasma is generated, the thermal plasma is a plasma in which electric powers having different phases are supplied from an AC power source to a plurality of electrodes as the electrodes and discharged in a pulsed manner. The fine particle production method according to the above.

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