JP2015205247A - Particulate material manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress adherence of a thermally treated product onto an inner wall surface of a discharge container which is caused by arc discharge and make it possible to continuously manufacture the thermally treated product.SOLUTION: There is provided particulate material manufacturing apparatus comprising: a discharge container 10 in which a plurality of discharge electrodes 14 are two-dimensionally or three-dimensionally arranged; and an AC power source 18 which applies alternating current having a phase difference to the discharge electrodes 14 to generate arc discharge between the discharge electrodes 14. The apparatus has: material supply means (20) for supplying a particulate material (32) to an arc discharge generating part 16 by the discharge electrodes 14 together with inert gas; shield gas forming means (24) for forming a shield gas flow 26 of inert gas flowing so as to surround an inert gas flow (22) containing a thermally treated product caused by arc discharge, in which the shield gas flow flows from the arc discharge generating part 16 toward an outflow port 12 of the discharge container 10; and recovery means (30) of the thermally treated product caused by arc discharge which flowed out from the discharge container 10 together with inert gas.

Description

  The present invention relates to a fine particle material production apparatus, and more particularly, to a fine particle material production apparatus suitable for use in producing a nanoparticle material.

  Lithium ion secondary batteries are expected to be used as power sources for hybrid vehicles and electric vehicles because of their high energy density, but they are still not satisfactory. Therefore, in recent years, it has been studied that the negative electrode is made of a silicon material instead of a carbon material. In particular, silicon-based nanomaterials are attracting attention as negative electrode materials for next-generation lithium ion secondary batteries because they have high capacity and little deterioration due to repeated charge / discharge cycles.

  As a method for producing a nanoparticle material, as shown in FIG. 1, a phase difference from a power supply device 3 is applied to a plurality of electrode rods 2 that are arranged point-symmetrically and abut each other at an interval as shown in FIG. A voltage is applied to generate a multi-arc M in the reaction furnace 1, and a gaseous or powdery raw material containing silicon and carbon is introduced into the multi-gas by a raw material supply pipe 4 incorporated in a carrier gas supply pipe 5. It is described that the material is continuously supplied to the center of the arc M, and the raw materials are sequentially pyrolyzed and synthesized into a silicon carbide powder by the multi-arc M. The formed fine powder of silicon carbide sequentially descends downward, is cooled while passing through the cooling device 6 connected to the lower side of the reaction furnace 1, and is taken out by the discharge device 7. In the figure, 8 is a pump for evacuating the inside of the reaction furnace 1, and 9 is a cyclone for separating and extracting raw materials that have not been put into the multi-arc M.

  In Patent Documents 2 and 3, in a helium atmosphere introduced into a discharge vessel, a multiphase alternating current having a phase difference is applied to three or more discharge electrodes arranged two-dimensionally or three-dimensionally, An arc discharge is generated, the carbon raw material or the composite carbon raw material is evaporated using the plasma region formed by the arc discharge, and the whole amount of the evaporated material is condensed in the plasma region and attached as soot on the inner wall of the discharge vessel. It is described.

Japanese Patent Application Laid-Open No. 7-187639 JP 2005-343784 A JP 2012-184128 A

  However, in the technique described in Patent Document 1, a heat treatment product adheres to the wall surface of the cooling device 6 connected to the lower side of the reaction furnace 1, and in some cases, the cooling device 6 is blocked and cannot be taken out to the outside. It had the problem that.

  On the other hand, in the techniques described in Patent Documents 2 and 3, it is necessary to recover the heat treatment product from the soot adhering to the inner surface of the discharge vessel after the discharge is completed, and it is impossible to continuously manufacture the heat treatment product. .

  The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide a fine particle material manufacturing apparatus capable of continuously generating a fine particle material including a nanoparticle material.

  According to the present invention, an arc discharge is generated between a discharge vessel in which a plurality of discharge electrodes are arranged two-dimensionally or three-dimensionally inside and an alternating current having a phase difference is applied to each of the discharge electrodes. An apparatus for producing a particulate material provided with an AC power source, comprising: a raw material supply means for supplying a raw material of fine particles together with an inert gas to an arc discharge generating portion by the discharge electrode; and an outlet of the discharge vessel from the arc discharge generating portion. Shield gas forming means for forming a shield gas flow of the inert gas flowing so as to surround the inert gas flow containing the heat treatment product by the arc discharge flowing toward the arc, and the arc discharge flowing out from the discharge vessel together with the inert gas The above-mentioned problem is solved by having a heat treatment product recovery means.

  Here, the flow rate of the shield gas flow of the inert gas can be made slower than the flow rate of the inert gas flow containing the heat treatment product by the arc discharge.

  Further, an inert gas circulation means for circulating an inert gas flowing out from the heat treatment product recovery means by the arc discharge to the raw material supply means and / or shield gas formation means can be provided.

  Further, the inert gas can be a rare gas.

  Further, the discharge vessel may be provided with a means for recovering unheated raw material that has not been heat-treated by the arc discharge.

  In the present invention, a gas flow is generated around the gas containing the raw material heat-treated by the arc plasma in the arc discharge generation portion, and the gas acts as a shield. With such a shielding gas, it is possible to suppress the adhesion of the heat treatment product to the inner wall surface of the discharge vessel and continuously produce the heat treatment product such as a particulate material.

Sectional drawing which shows the structure of the manufacturing apparatus proposed by patent document 1 Sectional drawing which shows the structure of 1st Embodiment of this invention. Sectional drawing which similarly shows the structure of 2nd Embodiment

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by the content described in the following embodiment and an Example. In addition, the constituent elements in the embodiments and examples described below include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in the so-called equivalent range. Furthermore, the constituent elements disclosed in the embodiments and examples described below may be appropriately combined or may be appropriately selected and used.

  In the first embodiment of the present invention, as shown in FIG. 2, three or more discharge electrodes 14 apply a three-dimensionally arranged discharge vessel 10 and alternating current having a phase difference to each of the discharge electrodes 14. A nanomaterial manufacturing apparatus having an AC power source 18 for generating an arc discharge between the discharge electrodes 14, wherein a raw material of fine particles is used as a rare gas in an arc discharge generation part (arc plasma field) 16 by the discharge electrode 14. A raw material supply nozzle (raw material supply means) 20 to be supplied together with a product gas flow 22 including a heat treatment product by arc discharge flowing from the arc discharge generation unit 16 toward the outlet 12 above the discharge vessel 10 is surrounded. A shielding gas supply nozzle (shielding gas forming means) 24 for forming a shielding gas flow 26 of the rare gas flowing in the same manner; A product collection filter (recovery means) 30 for collecting the heat treatment product by the spark discharge and a rare gas flowing out from the product collection filter 30 to the shield gas supply nozzle 24 and / or the raw material supply nozzle 20 A circulation pump (rare gas circulation means) 40 for circulation and an unheat treated raw material collector (collection means) for collecting the unheat treated raw material 32 falling from the arc discharge generator 16 without being heat treated by the arc discharge. 34 is provided.

  The shield gas supply nozzle 24 can be, for example, an L-shaped nozzle having a tip arranged upward.

  The raw material heated in the arc plasma field formed in the arc discharge generator 16 is sublimated and moves upward together with the product gas flow 22, and is cooled in the middle to become fine particles.

Here, the flow velocity V ₂ of the shielding gas flow 26 of the rare gas is a slower flow rate than the flow velocity V ₁ of the product gas stream 22 containing the heat treatment product. When fluids of similar density have a speed difference, the fluid on the slow flow side is entangled with the fluid on the fast flow side. Therefore, diffusion of the gas containing the raw material heated by the arc plasma (16) can be suppressed, and adhesion of the heat treatment product to the inner wall surface of the discharge vessel 10 can be reliably suppressed.

Since the flow velocity V ₂ of the shield gas flow 26 can be estimated if the flow rate of the shield gas and the diameter of the shield gas supply nozzle 24 are determined, the flow velocity V ₂ of the shield gas flow 26 is always generated by numerical simulation or the like. The flow rate of the shield gas can be controlled to be slower than the flow velocity V ₁ of the product gas flow 22.

  Examples of the rare gas include helium, neon, argon, krypton, xenon, and radon, but an inert gas other than the rare gas can also be used.

  The discharge electrode 14 can be made of carbon or tungsten, for example. Since the tungsten electrode needs to be cooled, the carbon electrode is preferable.

  When the commercial three-phase alternating current is used as the alternating current power source 18, the number of the discharge electrodes 14 can be set to, for example, 3, 6, 12 because the power source can be easily configured from the phase difference. .

  Further, the number of stages of the discharge electrode 14 is not limited to the two stages of the embodiment, and may be one stage or three or more stages.

  The number of the raw material supply nozzles 20 can be a multiple of 3, for example, or a multiple of 2, according to the number of discharge electrodes 14.

  In the present embodiment, since the circulation pump 40 is provided to circulate the rare gas, the rare gas can be reused and waste is reduced. Note that, for example, the raw material may be blown into the raw material supply nozzle 20 with a normal noble gas instead of the regenerative noble gas.

  In the above-described embodiment, the shield gas supply nozzle 24 is an L-shaped nozzle with the tip disposed upward, but the straight tubular nozzle is disposed obliquely upward as in the second embodiment shown in FIG. It is also possible to do.

The above embodiment is suitable for, for example, manufacturing silicon fine particles from silicon or mixing silicon and silicon dioxide SiO ₂ to manufacture silicon oxide SiO _x (0 <x <2). The manufacturing object of the invention is not limited to this, and is applicable to both the case where the raw material and the product are made into fine particles with the same substance and the case where the product is a reaction product of the raw material. The raw material is not limited to silicon, and any inorganic material can be manufactured.

DESCRIPTION OF SYMBOLS 10 ... Discharge container 12 ... Outlet 14 ... Discharge electrode 16 ... Arc discharge generation part 18 ... AC power supply 20 ... Raw material supply nozzle 22 ... Product gas flow 24 ... Shield gas supply nozzle 26 ... Shield gas flow 30 ... Product collection Filter 32 ... Unheated raw material 34 ... Unheated raw material collector 40 ... Circulation pump

Claims (5)

A plurality of discharge electrodes are provided with a discharge vessel disposed two-dimensionally or three-dimensionally therein, and an AC power source for applying an alternating current having a phase difference to the discharge electrodes to generate an arc discharge between the discharge electrodes. A fine particle material manufacturing apparatus,
A raw material supply means for supplying a raw material of fine particles together with an inert gas to an arc discharge generation part by the discharge electrode;
Shielding gas forming means for forming a shielding gas flow of an inert gas flowing so as to surround an inert gas flow including a heat treatment product by the arc discharge, flowing from the arc discharge generation portion toward the outlet of the discharge vessel; ,
Means for recovering the heat treatment product by arc discharge flowing out of the discharge vessel together with the inert gas;
An apparatus for producing a fine particle material, comprising:   2. The fine particle material manufacturing apparatus according to claim 1, wherein the flow rate of the shield gas flow of the inert gas is slower than the flow rate of the inert gas flow containing the heat treatment product by the arc discharge.   3. An inert gas circulation means for circulating an inert gas flowing out from the heat treatment product recovery means by the arc discharge to the raw material supply means and / or shield gas formation means. Fine particle material manufacturing equipment.   The fine particle material manufacturing apparatus according to claim 1, wherein the inert gas is a rare gas.   The fine particle material manufacturing apparatus according to any one of claims 1 to 4, wherein the discharge vessel includes a means for collecting an unheated raw material that has not been heat-treated by the arc discharge.