TWI629124B - Plasma device for manufacturing metallic powder and method for manufacturing metallic powder and metallic powder - Google Patents

Abstract

The present invention relates to a plasma device for producing a metal powder, comprising: a reaction container to which a metal material is supplied; and a plasma generated between the metal material in the reaction container and the metal material to evaporate to generate a metal vapor. a slurry torch; a carrier gas supply unit that supplies a carrier gas for transporting the metal vapor in the reaction container; and a cooling tube that cools the metal vapor transferred from the reaction container by the carrier gas to form a metal powder. In the plasma device for producing a metal powder, the cooling pipe is provided with the metal vapor and/or metal transferred from the reaction container by the carrier gas by cooling the periphery of the cooling pipe with a cooling fluid. a powder that does not directly contact the cooling fluid to indirectly cool the indirect cooling zone; and continues the indirect cooling zone to bring the cooling fluid into contact with the metal vapor and/or metal powder, and thereby directly Cooling directly cools the divided zone, and the aforementioned cooling pipe is in the longitudinal direction of the downstream side thereof In the above manner, the scraper disposed on the inner side of the cooling pipe is inclined by 10 to 80° in the horizontal direction, and the scraper attached to the inner wall of the cooling pipe is inserted from the downstream end of the cooling pipe in the longitudinal direction. In the aforementioned cooling tube.

Description

Plasma device for producing metal powder, method for producing metal powder, and metal powder

The present invention relates to a plasma device for producing a metal powder, and more particularly to a plasma device and a method for producing a metal powder comprising a tubular cooling tube in which molten metal evaporated and evaporated, thereby producing a metal powder.

In the production of an electronic component such as an electronic circuit or a wiring board, a resistor, a capacitor, or an IC package, a conductive metal powder is used to form a conductor film or an electrode. The properties or properties required for the metal powder as described above include fine powders having a small amount of impurities, an average particle diameter of about 0.01 to 10 μm, uniform particle shape or particle diameter, less aggregation, and dispersibility in the paste. Good, good crystallinity, etc.

In recent years, with the miniaturization of electronic components and wiring boards, the thinning or fine pitch of the conductor film or the electrode has been progressing. Therefore, a metal powder having a finer, spherical shape and high crystallinity is highly desired.

In one of the methods for producing the fine metal powder as described above, the plasma device for melting the metal vapor after the metal material is melted/evaporated in the reaction vessel by using the plasma, and the condensed metal powder is obtained It is known (refer to Patent Documents 1 and 2). In the plasma device, since the metal vapor is condensed in the gas phase, metal particles having less impurities, fineness, spherical shape, and high crystallinity can be produced.

Each of the plasma devices is provided with a long tubular cooling tube for performing a plurality of stages of cooling of the carrier gas containing the metal vapor. For example, Patent Document 1 includes: directly mixing the preheated heat in the carrier gas The first cooling unit that cools the gas, and the second cooling unit that cools by directly mixing the cooling gas at normal temperature.

Further, in the plasma device of Patent Document 2, the cooling fluid is circulated around the tubular body, whereby the fluid does not directly contact the carrier gas, and the indirect cooling partition region of the carrier gas is cooled. (first cooling unit); and then directly cooling the divided area (second cooling unit) by directly mixing the cooling fluid with the carrier gas to perform cooling.

In particular, in the latter case, the formation, growth, and crystallization of the core can be carried out stably, and a metal powder having a controlled particle size and particle size distribution can be obtained.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] US Patent Application Publication No. 2007/0221635

[Patent Document 2] Japanese Patent No. 3541939

However, in the plasma device described in these documents, when metal vapor is condensed in the cooling pipe, it is impossible to prevent a part of the metal vapor from adhering to the inner wall of the cooling pipe. The deposit gradually builds up, gradually obstructing the flow of the carrier gas in the cooling tube, and the problem of occluding the cooling tube may occur depending on the situation.

In particular, in the plasma device described in Patent Document 2, the deposit is more likely to adhere to the upstream side of the cooling pipe than the device of Patent Document 1 in which the cooling fluid mechanism is discharged over all the regions in the cooling pipe. The problem of the inner wall of the (first cooling unit side).

Conventionally, in order to remove the adherend as described above, it is necessary to periodically and/or irregularly stop the operation of the plasma device, and after the device is sufficiently cooled, the cooling tube is decomposed to remove the deposit in the tube.

However, these plasma devices also take a considerable amount of time after the generation of the plasma until the metal vapor can be stably formed. Therefore, in order to remove the deposit, in addition to the time required to decompose the cooling tube after stopping the plasma device and the time required for the actual deposit removal operation, it is necessary to consume the metal vapor after the operation of the device is restarted. The time required for the formation is a problem in terms of the production efficiency of the metal powder.

An object of the present invention is to solve the above problems and to provide a plasma device capable of easily removing adhering substances deposited/deposited on the inner wall of a cooling pipe in a plasma device for manufacturing a metal powder having a cooling pipe, and having a more efficient production efficiency. A method of producing a metal powder.

The plasma apparatus of the present invention includes: a reaction vessel to which a metal raw material is supplied; a plasma torch that generates a plasma between the metal raw material in the reaction vessel and evaporates the metal raw material to generate metal vapor; a carrier gas supply unit that supplies the carrier gas of the metal vapor in the reaction container; and a cooling tube that cools the metal vapor transferred from the reaction container by the carrier gas to form a metal powder, and the plasma for producing the metal powder The apparatus is characterized in that the cooling pipe is provided with cooling the periphery of the cooling pipe with a cooling fluid, so that the metal vapor and/or metal powder transferred from the reaction vessel by the carrier gas does not directly contact the metal vapor and/or metal powder. Cooling indirectly with fluid Cooling indirect cooling partitioning zone; and continuing the aforementioned indirect cooling partitioning zone to bring the cooling fluid into contact with the metal vapor and/or metal powder, and thereby directly cooling the cooled cooling zone, and The downstream side of the longitudinal direction is located above, and is disposed in the reaction container so as to be inclined by 10 to 80° with respect to the horizontal direction, and the scraper attached to the inner wall of the cooling pipe is removed by the length of the cooling pipe. The downstream end of the side direction is inserted into the aforementioned cooling pipe.

In the plasma device of the present invention, the cooling pipe is disposed in the reaction container so as to be inclined upward in the longitudinal direction so that the downstream side thereof is located above the horizontal direction, and the scraper attached to the inner wall of the cooling pipe is scraped off. The downstream end of the cooling pipe is inserted into the cooling pipe, so that the scraper can be reciprocated and/or driven in the cooling pipe, thereby removing the deposits without stopping the operation of the device, and can be easily performed. The recycling of the scraped deposits and the discharge of the metal powder can greatly improve the production efficiency of the metal powder.

[Formation of the Invention]

The present invention will be described below on the basis of specific embodiments, but the present invention is not limited thereto.

[First Embodiment]

In the first embodiment of the present invention, the transitional arc plasma apparatus according to the above-described Patent Document 2 is applied to the first embodiment of the present invention. The metal material is melted and evaporated in the inside of the reaction container 2, and the generated metal vapor is placed in the cooling pipe. 3 is internally cooled and condensed, thereby generating metal particles.

In the following description, the upstream side or the downstream side refers to the direction in the longitudinal direction of the cooling pipe 3 indicated by the arrow in FIG. 1 , and the upper or lower side refers to the vertical direction indicated by the arrow in FIG. 1 . Up and down direction.

Further, in the present invention, the metal material is not particularly limited as long as it is a conductive material containing a metal component of the target metal powder, and an alloy or a composite containing two or more metal components may be used in addition to the pure metal. Things, mixtures, compounds, etc. Examples of the metal component include silver, gold, cadmium, cobalt, copper, iron, nickel, palladium, platinum, rhodium, ruthenium, iridium, titanium, tungsten, zirconium, molybdenum, niobium and the like. Although it is not particularly limited, in terms of easiness of handling, it is preferable to use a metal material or an alloy material in the form of a granular or a block having a size of about several mm to several tens of mm.

Hereinafter, it is easy to understand that nickel powder is used as a metal powder and metal nickel is used as a metal material. However, the present invention is not limited thereto.

The metal nickel is prepared in advance in the reaction vessel 2 before the start of the operation of the apparatus, and is replenished from the feed port 9 at any time by the amount of reduction in the inside of the reaction vessel 2 in accordance with the amount of metal vapor formed after the start of the operation of the apparatus. Inside the reaction vessel 2. Therefore, the plasma device 1 of the present invention can continuously produce metal powder for a long period of time.

A plasma torch 4 is disposed above the reaction vessel 2, and a plasma generating gas is supplied to the plasma torch 4 through a supply pipe (not shown). In the plasma torch 4, the negative electrode 6 is used as a cathode, and a positive electrode (not shown) provided inside the plasma torch 4 is used as an anode. After the plasma 7 is generated, the anode is moved to the positive electrode 5, whereby the negative electrode 6 and the positive electrode 5 are used. A plasma 7 is generated between the reactor 7 and the heat of the plasma 7 to cause the reaction vessel At least a part of the metallic nickel in 2 is melted to form a molten metal 8 of nickel. Further, the plasma torch 4 evaporates a part of the melt 8 by the heat of the plasma 7, and generates nickel vapor (corresponding to the metal vapor of the present invention).

The carrier gas supply unit 10 supplies a carrier gas for transporting nickel vapor into the reaction container 2 . The carrier gas is not particularly limited as long as the metal powder to be produced is a noble metal, and an oxidizing gas such as air, oxygen or water vapor, an inert gas such as nitrogen or argon, or a mixed gas thereof can be used. In the case of oxidized nickel, copper or the like, it is preferred to use an inert gas. Unless otherwise stated, in the following description, nitrogen is used as the carrier gas.

Further, a reducing gas such as hydrogen, carbon monoxide, methane or ammonia, or an organic compound such as an alcohol or a carboxylic acid may be mixed in the carrier gas system as needed, and may be contained in order to improve/adjust the properties or characteristics of the metal powder. Oxygen, or other components such as phosphorus or sulfur. Further, the plasma generating gas used to generate the plasma also functions as a part of the carrier gas.

An introduction port 11 having a diameter smaller than the inner diameter of the cooling pipe 3 is provided between the reaction vessel 2 and the upstream end of the cooling pipe 3 (near the end on the upstream side of the cooling pipe shown in Fig. 1), and the reaction vessel 2 is The cooling pipes 3 are connected to each other through the inlet port 11. Therefore, the carrier gas system containing nickel vapor generated in the reaction vessel 2 is transferred to the cooling pipe 3 through the inlet port 11.

The cooling pipe 3 includes an indirect cooling partition IC that indirectly cools nickel vapor and/or nickel powder contained in the carrier gas, and a direct cooling partition that directly cools the nickel vapor and/or the nickel powder contained in the carrier gas. DC. Further, as will be described later, the cooling pipe 3 may be additionally provided with standby Use the division area AC.

In the indirect cooling partition IC, cooling or heating is performed around the cooling pipe 3 by using a cooling fluid or an external heater, and cooling is performed by controlling the temperature of the indirect cooling zone IC. As the fluid for cooling, the carrier gas or other gas may be used, and a liquid such as water, warm water, methanol, ethanol or a mixture thereof may be used. However, from the viewpoint of cooling efficiency and cost, it is preferred to use water or warm water in the cooling fluid to circulate around the cooling pipe 3 to cool the cooling pipe 3.

In the indirect cooling partition IC, the nickel vapor which is transferred to the carrier gas in the cooling pipe 3 while maintaining the high temperature is cooled by the radiation at a relatively gentle speed, and is subjected to a stable and uniform temperature control atmosphere. The formation, growth, and crystallization of the nucleus are performed to form a nickel powder having a uniform particle diameter in the carrier gas.

In the direct cooling partition DC, the nickel vapor and/or nickel powder transferred from the indirect cooling partition IC is discharged or mixed with a cooling fluid supplied from a cooling fluid supply unit (not shown). Perform direct cooling. Further, the cooling fluid used for directly cooling the divided region DC may be the same as the cooling fluid used in the indirect cooling partition IC, or may be different, but from the viewpoint of ease of processing or cost. It is preferable to use the same gas as the carrier gas (nitrogen in the following embodiment).

When a gas is used, a reducing gas or an organic compound, a component such as oxygen, phosphorus, or sulfur may be used in combination as needed in the same manner as the carrier gas. In addition, if the cooling fluid contains a liquid, the liquid system is sprayed In the state of being introduced into the cooling pipe 3.

Nickel vapor and nickel powder are mixed in the carrier gas in the indirect cooling partition IC, but the ratio of the downstream side nickel vapor is lower than that on the upstream side. Further, depending on the apparatus, nickel vapor and nickel powder may be mixed in the carrier gas in the direct cooling partition DC. However, as described above, it is preferable that the formation, growth, and crystallization of the nucleus are performed in the indirect cooling partition IC, and it is preferable that the carrier gas in the direct cooling partition DC does not contain nickel vapor.

In the operation of the plasma device 1, in the cooling pipe 3, a part of the nickel powder in the carrier gas or a precipitate derived from the nickel vapor gradually adheres to the inner wall of the cooling pipe 3, and is formed as an oxide or other compound as the case may be. And stacked. If the accumulation of the deposits due to the nickel vapor is further increased, the inner diameter of the cooling tube 3 may be narrowed, or the particle size or particle size distribution of the nickel powder may be removed in addition to the flow of the chaotic carrier gas. In addition to the adverse effects of the control, the inside of the cooling pipe 3 may be closed depending on the situation. In particular, on the upstream side of the cooling pipe 3 having the indirect cooling division area IC, it is found that the deposit tends to increase.

In the present invention, it is preferable that the downstream end of the cooling pipe 3 or the vicinity thereof is provided with an induction pipe that induces a direction in which the carrier gas for transporting the metal powder is directed in a direction different from the longitudinal direction of the cooling pipe 3 . .

The induction tube 13 in the first embodiment induces the carrier gas in a direction substantially perpendicular to the longitudinal direction of the cooling tube 3. The carrier gas induced by the induction tube 13 is transported to a trap (not shown), and is separated into metal powder and carrier gas in the trap to recover the metal powder. In addition, the carrier gas separated by the trap can also be configured to be loaded The body gas supply unit 10 is reused.

Here, an inducing gas ejecting portion that ejects a gas in the induction direction may be provided in the induction tube 13 or in the vicinity thereof. By inducing the gas, the transfer direction of the carrier gas can be smoothly performed. As the gas to be induced, the same gas as the carrier gas described above may be used.

The present invention has a scraper for removing an adhering matter adhering to the cooling pipe 3, and is characterized in that it is inserted into the downstream end of the cooling pipe.

As shown in Fig. 2, the scraper 20 of the first embodiment has a shape of a scraper head 22 for scraping off the deposit at one end of the rod-shaped shaft 21, and the entire length of the scraper 20 is cooled by specific cooling. The length of the tube 3 in the longitudinal direction is preferably long. In the scraper 20, the scraper head 22 is housed in the cooling pipe 3, and the shaft 21 is inserted into the insertion port 31 provided at the downstream end of the cooling pipe 3, and at least a part thereof is disposed outside the cooling pipe 3.

In a conventional plasma device equipped with a cooling tube, the trap is often disposed on the extension of the tubular cooling tube, and the scraper 20 of the above-described shape is not easy in itself, but preferably by providing the induction tube 13, A space can be formed on the extension of the cooling pipe 3, and the scraper 20 becomes easy to configure. However, if the device is not complicated, the scraper 20 may be disposed without the induction tube. In the present invention, the induction tube is not essential.

Since the shaft 21 is attached to the insertion port 3, the shaft 21 can freely reciprocate in the longitudinal direction of the cooling pipe 3, and the rotation of the shaft 21 about the axis of the shaft 21 is free.

Further, the maximum length of the radial direction of the scraper head 22 (the direction orthogonal to the axis 21) is set to be smaller than the minimum inner diameter in the cooling tube 3.

In the first embodiment configured as described above, when the deposit is periodically or irregularly removed, the shaft 21 outside the cooling pipe 3 is operated to reciprocate the shaft 21 in the longitudinal direction of the cooling pipe 3, and in the direction around the axis Rotate. The operation of the shaft 21 at this time may be performed by a human hand or by a driving mechanism such as a motor. Next, the scraper head 22 applies a physical force to the deposit on the inner wall of the cooling pipe 3, and the deposit can be effectively scraped off.

2(A) to (C) are detailed views of the scraper head 22 of the first embodiment, and Fig. 2(B) is a schematic view of an arrow viewed by line II-II of Fig. 2(A). Fig. 2(C) is a schematic view of an arrow viewed from line IIA-IIA' of Fig. 2(B).

As shown in the figure, the scraper head 22 has a first scraper head 22a, a second scraper head 22b, and a projecting claw 27, and each of the first scraper head 22a and the second scraper head 22b has a ring having three spokes. shape.

Further, each of the first scraper head 22a and the second scraper head 22b is provided with claw portions 23a and 23b having zigzag shapes having different tooth angles. Therefore, when the scraper head 22 is moved on the upstream side of the cooling pipe 3, the adhering matter of the inner wall of the cooling pipe 3 is roughly scraped off by the claw portion 23a of the first scraper head 22a, and then the second scraper is used. The claw portion 23b of the head 22a scrapes off the remaining deposit.

Further, the projecting claws 27 are provided at positions on the scraper head 22 opposed to the introduction port 11, so that the scraper head 22 can be rotated and/or reciprocated at the upstream end of the cooling pipe 3 as needed. This removes the adhering matter attached to the inlet port 11 and its surroundings.

The material of the scraper 20 is preferably heat-resistant, and is preferably formed of, for example, SUS or Inconel. In addition, the shaft 21 and the scraper head 22 may be integrally formed, or may be joined to different individuals. In addition, the shaft 21 If the scraper head 22 is integrally movable, it does not necessarily have to be fixed, and may be connected through, for example, a damper mechanism including an elastic body such as a spring.

When the deposit removal operation is not performed, for example, when the metal powder is produced, it is preferable that the scraper head 22 stands by on the downstream side of the cooling pipe 3.

The standby position of the scraper head 22 may be more downstream than the indirect cooling partition IC (first cooling unit) in which the growth of the metal powder is substantially completed, and is preferably in the vicinity of the downstream end. The standby position of the scraper head 22 is set to the downstream side after the direct cooling of the divided area DC, whereby the adhering matter can be suppressed from adhering to the scraper head 22, and in addition, the turbulent flow of the carrier gas by the scraper head 22 can be reduced. The risk of adversely affecting the particle size or particle size distribution of the metal powder.

In the first embodiment, the standby partition area AC is provided in the cooling pipe 3, and the scraper head 22 is placed in the standby division area AC when the work is not performed.

However, the standby division area AC is not necessarily provided, and it may be made to stand by in the direct cooling division area DC as will be described later. Further, when the scraper head 22 is formed of a material or a shape member to which the attached matter is less likely to adhere, or when the turbulent flow of the carrier gas is less likely to occur, the scraper head 22 may be placed on the upstream side.

The plasma device 1 of the present invention is characterized in that the cooling pipe 3 is inclined in a range of 10 to 80° with respect to the horizontal direction so that the downstream side thereof is located above.

In a conventional plasma device equipped with a cooling pipe, most of the cases are to provide a cooling pipe in a horizontal direction or a vertical direction, but if it is horizontal When the cooling pipe is installed, since the deposit scraped off by the scraper 20 is accumulated in the cooling pipe, it is necessary to newly provide a mechanism for recovering the accumulated deposit.

When the cooling pipe is installed in the vertical direction, the scraped deposit does not accumulate in the cooling pipe, but if it is a cooling pipe with the vertical direction facing downward (the downstream side of the cooling pipe is below), there will be scraping. The adhering matter is mixed into the metal powder as the target material to reduce the quality of the metal powder. Further, in the cooling pipe which is directed upward in the vertical direction (the downstream side of the cooling pipe is upward), the scraped deposits are returned to the reaction vessel, and the melt temperature is lowered or the impurity concentration is increased.

According to the present invention, the scraper 20 is provided, and the cooling pipe 3 is inclined in a range of 10 to 80° with respect to the horizontal direction, whereby the scraping by the scraper 20 can be performed without particularly resetting the recovery mechanism. The matter is concentrated on the upstream side of the cooling pipe 3. The preferred tilt angle is 20 to 70 degrees, and the preferred tilt angle is 30 to 60 degrees.

The cooling pipe 3 of the first embodiment shown in Fig. 1 is provided so as to be inclined by 45° with respect to the horizontal direction so that the downstream side thereof is located above.

The deposits scraped off by the scraper 20 are concentrated on the upstream side of the cooling duct 3 only by the reciprocating motion of the scraper 20 and the gravity, without any special recovery mechanism.

Further, in the first embodiment, since the reaction container 2 and the cooling pipe 3 communicate with each other through the introduction port 11 having a diameter smaller than the inner diameter of the cooling pipe 3, the concentrated deposits are less likely to be poured back into the reaction container 2. As described above, in the present invention, it is preferable that the upstream end of the cooling pipe 3 communicates with the reaction vessel 1 through the introduction port 11 having a diameter smaller than the inner diameter of the cooling pipe 3.

Further, in the first embodiment, the upstream side of the cooling pipe 3 is provided with an opening 32 for discharging the deposit to the outside of the cooling pipe 3. When the opening 32 is provided in the direct cooling partition DC having the cooling fluid supply unit (not shown), the configuration of the cooling fluid supply unit is complicated, and therefore it is preferable that the opening 32 is provided in the indirect cooling division area IC.

The opening 32 is provided with an opening/closing jaw 33 formed so as not to cause a step difference with the inner wall of the cooling pipe 3, and is opened only during the attachment removing operation. Thereby, in the production of a general metal powder, turbulence in the carrier gas can be suppressed as much as possible.

The connecting portion 34 is provided to surround the opening and closing jaws 33, and a recovery container 35 that can attach and detach the connecting portion 34 is attached. When the deposit removal operation is performed, the opening and closing jaws 33 are opened, and the adhering substances are discharged from the opening 32 to the outside of the cooling tube 3, and are collected by the recovery container 35.

[Second Embodiment]

In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will be omitted below.

In the second embodiment, the cooling pipe 103 of the plasma device 101 is provided so as to be inclined by 70° with respect to the horizontal direction so that the downstream side thereof is located above. Further, the opening and closing crucible 133 is a sliding door type that slides along the outer wall of the cooling pipe 103.

Fig. 3(B) is a schematic view of an arrow viewed from the line III-III of Fig. 3(A). As shown in the figure, in the second embodiment, the curved induction tube 113 and the downstream end surface of the cooling tube 103 are shown. By connecting, the conveyance direction of the carrier gas containing the metal powder is induced to be not in the longitudinal direction of the cooling pipe 103. The same direction.

4(A) to 6(E) are detailed views of the scraper head 122 of the second embodiment, and Fig. 4(B) is a schematic view of the arrow viewed from line IV-IV of Fig. 4(A), Figure 4 (C) is a schematic view of the arrow viewed from the line IVA-IVA' of Figure 4 (B), and Figure 4 (D) and Figure 4 (E) are the IVB-IVB of Figure 4 (B) 'The arrow diagram of the line.

As shown in Fig. 4(A), in the second embodiment, the handlebar 128 is provided in the vicinity of one end portion of the scraper 120 so that the operation of the shaft 121 by the human hand is easy.

Further, as shown in FIGS. 4(B) to 4(E), the scraper head 122 is composed of four spokes radially extending around the shaft 121 and two claw portions 125 having different projecting lengths. The shape of the annular claw portion 124 is 126, and the outer diameter of the scraper head 122 is formed to be slightly smaller than the inner diameter of the cooling pipe 103.

Further, as shown in Fig. 3(A), the downstream end of the cooling pipe 103 is provided with a shaft guide 140 for guiding the operation of the scraper 120 for reciprocating movement. In the present embodiment, the scraper 120 is inserted. In the insertion hole 131 of the shaft guide 140.

In the second embodiment, when the attached matter is removed, the handlebar 128 is operated by a human hand, and the scraper 120 is rotated and/or reciprocated.

Further, since the scraper head 122 has three kinds of claw portions, when the scraper head 122 moves toward the upstream side of the cooling pipe 103, the attached object is first scraped off by the most protruding first projecting claw 125, and then borrowed. The second projecting claws 126 and the annular claw portions 124 can scrape off the remaining deposits without missing, and the deposits can be efficiently removed with a small force.

[Third embodiment]

In the fifth embodiment and the sixth embodiment, the same components as those in the first to the second embodiments are denoted by the same reference numerals, and the description thereof will be omitted below.

In the third embodiment, the cooling pipe 203 of the plasma device 201 is disposed so as to be inclined by 20° with respect to the horizontal direction so that the downstream side thereof is located above. In the present embodiment, the induction tube 213 has a cross-sectional shape or a diameter substantially the same as that of the cooling pipe 203, and is continuously curved by the downstream end of the cooling pipe 203, thereby inducing the conveying direction of the carrier gas containing the metal powder to the cooling pipe. The longitudinal direction of 203 is a different direction.

In the present embodiment, the standby partition area AC is not provided, and the scraper head 222 stands by in the direct cooling divided area DC.

Further, in the present embodiment, since the inclination angle of the cooling pipe 203 is relatively gentle 20°, the introduction port is not provided between the reaction container 2 and the cooling pipe 203.

An opening/closing port 33 is provided upstream of the cooling pipe 203, and the unloading recovery container 235 is attached to the cooling pipe 203 without being transmitted through the connection portion so as to cover the opening and closing port 33. A partition plate 236 is provided inside the recovery container 235. When the opening/closing port 33 is opened, the carrier gas flowing into the recovery container 235 can prevent the deposit in the recovery container 235 from flowing back into the cooling pipe 203.

One end of the shaft 221 that is inserted into the shaft guide 140 is connected to the scraper drive unit 240, and the scraper drive unit 240 is provided with a drive mechanism that reciprocates in the longitudinal direction while the scraper 220 is rotated. Graphic).

Fig. 6(A) to Fig. 6(C) are detailed views of the scraper head 222 of the third embodiment, and Fig. 6(B) is an arrow viewed by line VI-VI of Fig. 6(A). Fig. 6(C) is a schematic view of an arrow viewed by the line VIA-VIA' of Fig. 6(B).

As shown in Fig. 6 (A) to (C), the scraper 220 in the third embodiment has a dome-shaped scraper head 222. As shown, the scraper head 222 is coupled to the annular claw portion 223 by four arcuate spokes extending near one end of the shaft 221.

[Other variants]

Various other modifications are included in the present invention.

For example, if the scraper head can remove the attached matter, the claw portion is not necessarily required, and the shape and the number of the scraper head or the claw portion are not limited.

If a water-cooling mechanism that circulates a fluid such as water is provided inside the scraper head or inside the shaft, deformation due to heat of the scraper can be suppressed.

The position or the number of the openings provided in the cooling pipe is not limited, and may be appropriately changed depending on the inclination of the cooling pipe or the shape of the scraper.

Further, the shape of the induction tube may be formed in a space in which the scraper is disposed on the extension of the cooling tube, and may be, for example, an S-shape, a crank shape, or a spiral shape in addition to the above examples.

1, 101, 201‧‧‧ plasma device

2‧‧‧Reaction container

3, 103, 203‧‧‧ cooling tube

4‧‧‧Electric torch

5‧‧‧ positive

6‧‧‧negative

7‧‧‧ Plasma

8‧‧‧ melt

9‧‧‧ Feed inlet

10‧‧‧Carrier Gas Supply Department

11‧‧‧Import

13, 113, 213‧‧‧ induction tube

20, 120, 220‧‧‧ scrapers

21, 121, 221‧‧

22, 22a, 22b, 122, 222‧‧‧ scraper head

23a, 23b, 223‧‧‧ claws

27, 125, 126‧‧ ‧ protruding claws

31‧‧‧ insertion port

32‧‧‧ openings

33, 133‧‧‧ Open and close

34‧‧‧Connecting Department

35, 235‧‧ ‧ recycling container

124‧‧‧Ringed claws

128‧‧‧handle

131‧‧‧Insert hole

140‧‧‧Axis guides

236‧‧ ‧ partition

240‧‧‧Scraper drive department

AC‧‧‧Standby area

DC‧‧‧Direct cooling zone

IC‧‧‧Indirect cooling zone

Fig. 1 is a view showing a plasma device according to a first embodiment.

Fig. 2 is a view showing the scraper of the first embodiment.

Fig. 3 is a view showing the plasma device of the second embodiment.

Fig. 4 is a view showing the scraper of the second embodiment.

Fig. 5 is a view showing a plasma device according to a third embodiment.

Fig. 6 is a view showing the scraper of the third embodiment.

Claims (21)

A plasma device for producing a metal powder, comprising: a reaction vessel which is supplied with a metal material; and a plasma torch which generates a plasma between the metal material in the reaction container and the metal material. The metal raw material is evaporated to generate a metal vapor; the carrier gas supply unit supplies a carrier gas for transporting the metal vapor to the reaction vessel; and a cooling pipe having a communication with the reaction vessel The upstream end and the downstream end of the end on the opposite side of the upstream end in the longitudinal direction, the metal vapor transferred from the reaction vessel by the carrier gas is transferred from the upstream end toward the downstream end Cooling and generating a metal powder; the plasma device for producing a metal powder is characterized in that a scraper that removes an adhering matter attached to an inner wall of the cooling pipe is inserted into the cooling pipe from the downstream end of the cooling pipe Inside. The plasma device for producing a metal powder according to the first aspect of the invention, wherein the cooling pipe has a first portion including the upstream end, and a first portion located closer to a downstream side of the longitudinal direction of the cooling pipe than the first portion and including the downstream end In the second portion, the first portion includes an opening for discharging the deposit to the outside of the cooling tube. The plasma device for producing a metal powder according to the first aspect of the invention, wherein the cooling pipe communicates with the reaction vessel through an inlet port having a diameter smaller than an inner diameter of the cooling pipe at the upstream end. For example, the plasma device for manufacturing metal powder according to item 1 of the patent application, The cooling pipe has a first portion including the upstream end, and a second portion located downstream of the first portion in the longitudinal direction of the cooling pipe and including the downstream end, and the cooling pipe is the second portion of the cooling pipe Part of the induction tube is provided to induce the carrier gas to a direction different from the longitudinal direction of the cooling tube. The plasma device for producing a metal powder according to the first aspect of the invention, wherein the cooling pipe has a first portion including the upstream end, and a downstream portion of the first portion that is closer to the longitudinal direction of the cooling pipe and includes the downstream end. In the second part, the first part further includes an indirect cooling zone, and indirectly cools the metal vapor and/or metal powder transferred from the reaction vessel by the carrier gas. The plasma device for producing a metal powder according to claim 5, wherein the second portion further comprises a direct cooling zone, and the metal vapor and/or metal powder transferred from the reaction vessel by the carrier gas is directly subjected to cool down. A method for producing a metal powder, which is characterized in that a metal powder is produced by using a plasma device for producing a metal powder as in the first aspect of the patent application. A method for producing a metal powder, comprising the steps of preparing a plasma device for producing a metal powder, and the step of producing a metal powder using the plasma device for producing a metal powder, wherein the step of the plasma device for producing a metal powder comprises: Providing a reaction vessel which is supplied with a metal raw material; Providing a plasma torch which generates a plasma between the metal material in the reaction vessel and the metal material to evaporate to form a metal vapor; and provides a carrier gas supply portion, the carrier gas supply portion is used a carrier gas for transporting the metal vapor is supplied into the reaction vessel; and a cooling pipe having an upstream end in communication with the reaction vessel and a downstream end of an end portion on the opposite side of the upstream end in a longitudinal direction thereof a first portion including the upstream end and a second portion including the downstream end and located on a downstream side of the first portion, and the metal vapor transferred from the reaction container by the carrier gas is directed from the upstream end to the downstream side The end transfer is cooled while cooling to form a metal powder; and a scraper is provided, wherein the scraper is inserted into the cooling tube from the downstream end of the cooling tube and the adhering matter attached to the inner wall of the cooling tube is removed; The step of producing the metal powder is performed in a state where the scraper is in a standby state of the second portion of the cooling pipe. . The method for producing a metal powder according to the eighth aspect of the invention, wherein the metal raw material contains at least one element selected from the group consisting of silver, gold, copper, nickel, and palladium. A method for producing a metal powder, comprising the steps of preparing a plasma device for producing a metal powder, and the step of producing a metal powder using the plasma device for producing a metal powder, wherein the metal powder is produced The step of using a plasma device comprises: providing a reaction vessel which is supplied with a metal material; and providing a plasma torch which generates a plasma between the metal material in the reaction vessel and the metal material Evaporating to form a metal vapor; providing a carrier gas supply unit that supplies a carrier gas for transporting the metal vapor to the reaction vessel; and providing a cooling tube having a communication with the reaction vessel The upstream end, the downstream end of the end portion on the opposite side of the upstream end in the longitudinal direction, the first portion including the upstream end, and the second portion including the downstream end and located on the downstream side of the first portion will The reaction vessel is cooled by the transfer of the metal vapor transferred by the carrier gas from the upstream end toward the downstream end to form a metal powder; and a scraper is provided, the scraper being inserted from the downstream end of the cooling tube Removing the deposit attached to the inner wall of the cooling tube in the cooling tube; characterized in that: the aforementioned cooling tube is more An opening provided in the first portion and discharging the deposit removed by the scraper to the outside of the cooling pipe, and a switchable opening and closing door provided in the opening, the step of manufacturing the metal powder is to close the aforementioned It is carried out in the state of opening and closing the door. A method for producing a metal powder according to claim 10, The middle recovery container can be attached to and detached from the opening of the cooling pipe, and the recovery container collects the deposit discharged to the outside of the cooling pipe. The method for producing a metal powder according to claim 11, wherein the recovery container is attached so as to cover the opening. The method for producing a metal powder according to claim 10, further comprising the step of recovering the aforementioned metal powder prepared by a trap. The method for producing a metal powder according to claim 10, wherein the first portion of the cooling tube includes an indirect cooling region, and the metal vapor and/or metal powder transferred from the reaction vessel by the carrier gas is indirectly performed. Cooling, the opening is provided in the indirect cooling region. The method for producing a metal powder according to claim 14, wherein in the indirect cooling region, water or warm water is used to cool the cooling flow system around the cooling pipe. A method for producing a metal powder, comprising: a reaction vessel, a plasma torch, a carrier gas supply unit, and a cooling pipe having an upstream end and a downstream end; and a scraping in which the downstream end of the cooling pipe is inserted into the cooling pipe a plasma device for producing a metal powder; supplying a metal material to the reaction container; forming a plasma between the metal material supplied to the reaction container and the plasma torch, evaporating the metal material to form a metal vapor; Supplying carrier gas into the reaction vessel and transferring the aforementioned metal vapor to the aforementioned cooling tube; The molten metal is transferred from the upstream end of the cooling pipe to the downstream end and cooled to form a metal powder. The method for producing a metal powder is characterized in that the cooling pipe has a first portion including the upstream end, and includes the foregoing a second portion of the downstream end located on the downstream side of the first portion, wherein the method for producing the metal powder includes a step of removing the adhering matter adhering to the inner wall of the first portion of the cooling tube by the scraper; And a step of causing the scraper to generate metal powder in a state in which the second portion of the cooling tube is in standby. A method for producing a metal powder, comprising: a reaction vessel, a plasma torch, a carrier gas supply unit, and a cooling pipe having an upstream end and a downstream end; and a scraping in which the downstream end of the cooling pipe is inserted into the cooling pipe a plasma device for producing a metal powder; supplying a metal material to the reaction container; forming a plasma between the metal material supplied to the reaction container and the plasma torch, evaporating the metal material to form a metal vapor; The carrier gas is supplied to the reaction vessel, and the metal vapor is transferred to the cooling pipe; and the metal vapor transferred is transferred from the upstream end of the cooling pipe to the downstream end to be cooled, thereby generating metal powder, and the metal powder is produced. The cooling pipe has a first portion including the upstream end, and a second portion including the downstream end and located downstream of the first portion. a part of the opening of the first portion of the cooling pipe and an opening and closing door that is openable and closable in the opening, the method for producing the metal powder comprising: adhering to the inner wall of the cooling pipe by the scraper The deposit is removed, and the removed adherend is discharged from the opening to the outside of the cooling pipe; and the step of generating the metal powder in a state where the opening and closing door is closed. The method for producing a metal powder according to any one of the preceding claims, wherein the scraper comprises a rod-shaped shaft and a scraper head provided at one end of the shaft, the aforementioned The scraper head is disposed inside the cooling pipe, and the other end of the shaft extends to the outside of the cooling pipe via an insertion port provided at the downstream end of the cooling pipe. The method for producing a metal powder according to any one of the preceding claims, wherein the cooling pipe is inclined such that a downstream end of the cooling pipe is located above an upstream end of the cooling pipe. And disposed in the aforementioned reaction vessel. The method for producing a metal powder according to any one of claims 7, 8, 10, 16, or 17, wherein the carrier gas contains at least one of an organic compound, phosphorus or sulfur. A metal powder produced by the method for producing a metal powder according to any one of claims 7, 8, 10, 16, and 17.