JPS59166605A - Apparatus for preparing ultra-fine particle - Google Patents

Abstract

PURPOSE:To efficiently prepare a uniform ultra-fine particle by discharging the generated ultra-fine particle from a melting chamber within a short time, by obliquely arranging an electrode member, a gas inflow pipe and a gas outflow pipe so as to form a predetermined angle with respect to the stock material of the melting chamber. CONSTITUTION:An electrode member 3, a gas inflow pipe 1 and a gas outflow pipe 2 are obliquely arranged in an angle range of about 40-80 deg. with respect to the stock material A such as an alloy received in the recessed part 11a of the crucible 11 in a melting chamber 13. Predetermined gas (hydrogen-containing gas or nitrogen-containing gas) is flowed from nozzle pipes 6, 7 and an auxiliary nozzle pipe 8 to generate an arc between the leading end of an electrode element 5 and the upper surface of the stock material A. The stock material A is melted and the atmospheric gas is activated by said arc while an ultra-fine particle is generated from the molten stock material A by the reaction of the molten stock material A and the inert gas. The discharged gas containing the ultra-fine particle is rapidly exhausted from the gas outflow pipe 2 and is not stayed in the melting chamber 13.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for producing ultrafine particles using an arc (including a plasma arc), and particularly relates to an improvement in the flow of atmospheric gas.

In recent years, the unique properties of ultrafine particles have attracted attention, and their future applications in a wide range of technical fields such as electronics and catalytic chemistry are expected.

Various types of ultrafine particle manufacturing equipment have been developed, but
One of them is one that uses an arc. Specifically, a long electrode member is installed vertically within the melting chamber, and a crucible is installed at the lower end of the melting chamber below the electrode. Then, hydrogen-containing gas or bed-containing gas flows downward from the top of the melting chamber, and this gas is further guided to a gas outlet pipe connected directly above, beside, or below the melting chamber. .

In the above-described conventional manufacturing apparatus, gas is blown downward from the top of the melting chamber, so that it collides with the molten raw material and the discharged gas containing ultrafine particles that are generated in large numbers, generating severe turbulence. For this reason, the ultrafine particles stay in the high-temperature melting chamber for a long time, and as a result, the ultrafine particles adhere to each other and grow, resulting in coarse grains.Also, the ultrafine particles adhere to various places in the furnace and cause sintering. This may cause problems such as .

The present invention has been made based on the above circumstances, and its purpose is to provide an apparatus that can efficiently produce ultrafine particles with a small particle size and uniformity by smoothing the flow of gas.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In the figure, reference numeral 1 denotes a gas inflow pipe whose outer periphery is water-cooled, and this gas inflow pipe 1 is installed at an angle of approximately 45°. A melting chamber 13 whose outer periphery is water-cooled is connected to the lower end of the gas inlet pipe 1 . A gas outlet pipe 2 whose outer periphery is water-cooled is connected to the melting chamber 13. Gas outflow pipe 2 is also approximately 45
°It is installed at an angle. Gas inflow pipe 1 and gas outflow pipe 2
As shown in FIG. 2, they are arranged at about 180 degrees opposite each other. Inside the gas inflow pipe 1 is a long electrode member 3.
is installed obliquely along the axis of the gas inflow pipe 1. The electrode member 3 is composed of a water-cooled copper tube 4 and an electrode element 5 fixed to the lower end thereof. water cooled steel pipe 4
is supported on the upper part of the gas inflow pipe 1. The electrode element 3 is surrounded by a double nozzle tube 6.7. The distance between the electrode member 3 and the first nozzle pipe 6 on the inside and the distance between the first nozzle pipe 6 and the second nozzle pipe 7 on the outside are relatively narrow.

An auxiliary nozzle pipe 8 is inserted through the side surface of the melting chamber 13 . As shown in FIG. 2, this auxiliary nozzle pipe 8 faces into the melting chamber 13 not in parallel with the electrode member 3 and the nozzle pipes 6 and 7, but intersects with it at a predetermined angle.
1 facing the wall. A flange 9 is fixed to the lower end of the melting chamber 13, and seven other flange 10 are connected to this seven flange 9.

A crucible 11 is supported on the flange 10.

A recess 11a is formed in the center of the crucible 11, and the raw material A is accommodated in the recess 11a. A case 12 is fixed to the lower surface of the flange 10, and the crucible 11 is cooled by cooling water flowing inside the case 12.

In the figure, 12a is an inlet portion of the cooling water, and 12b is an outlet portion.

In the above configuration, a metal, a metalloid, or a semiconductor can be used as the raw material A. and a first nozzle pipe 6. Second
A predetermined gas is blown onto the upper surface of the raw material A from the nozzle No. 7. Further, a predetermined gas flows from the upper part of the gas inflow pipe 1 toward the crucible 11 .

Furthermore, a predetermined gas also flows in from the auxiliary nozzle pipe 8.

The predetermined gas here is a hydrogen-containing gas or an element-containing gas. The gas flow rate is usually fastest inside the first nozzle pipe 6, then slowest inside the second nozzle pipe 7, and then slowest inside the ringing curtain 1, but each flow speed can be adjusted.

With the gas flowing as described above, an arc is generated between the tip of the electrode element 5 and the upper surface of the raw material A.

This arc causes the raw material A to be melted in the bath. Further, the above-mentioned atmospheric gas is activated by the arc, and ultrafine particles are generated from the bath molten raw material A due to the reaction between the molten raw material A and the activated gas.

The released gas containing ultrafine particles generated from the molten raw material A as described above is carried by the gas obliquely blown from the nozzle pipes 6 and 7 and the gas inflow pipe 1, and is promptly sent to the gas outflow pipe 2. . Therefore, after the ultrafine particles are generated, they are sent to the gas outlet pipe 2 within a short time without staying in the melting chamber 13, and the ultrafine particles adhere to each other and become coarse particles, or the inner surface of the melting chamber 13. Problems such as sintering can be resolved.

Furthermore, although some of the ultrafine particles may remain near the peripheral wall of the melting chamber 13, the gas discharged from the auxiliary nozzle pipe 8 flows along the peripheral wall of the melting chamber 13 as shown in FIG. Therefore, retention of ultrafine particles can be prevented.

Note that the present invention is not limited to the embodiments described above, and various embodiments are possible.

For example, the inclination angle of the gas inflow pipe and gas outflow pipe is 4
The angle is not limited to 5 degrees, but can be arbitrarily selected within the range of 40 to 80 degrees with respect to the horizontal plane. If the inclination angle of the gas inflow pipe and gas outflow pipe is less than 40°, the arc will become unstable9808
If it is more than that, the gas flow will not be smooth. moreover,%
The pole member may be configured to generate a plasma arc.

As explained above, according to the device of the present invention, the generated ultrafine particles can be quickly sent out of the furnace by improving the gas flow, and as a result, the ultrafine particles with small and uniform particle size can be efficiently sharpened. Can be built.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of the apparatus of the present invention, and FIG. 2 is a partially cutaway plan view. 1... Gas inflow pipe, 2... Gas outflow pipe, 3... End electrode member, 6, 7... Nozzle pipe, 8... ... Auxiliary nozzle pipe, 11 ... Crucible, 13 ... Melting chamber, A ... Raw material. Applicant Higashidoor Steel Co., Ltd. Agent Patent Attorney Watanabe Written amendment to promotion procedure (spontaneous) Showa RG Year 1 day of every month Director General of the Patent Office 1. Indication of the case 1989 Patent Application No. 39189 2. Title of the invention Particulate manufacturing device 3, relationship with the case of the person making the amendment Patent applicant 4, agent 151 Column 6 of “Detailed description of the invention” of the specification, content of amendment (1) Specification, page 6, item 19 In the fourth line of page 7, the statement ``For example, the gas inflow pipe...will no longer be smooth.'' will be corrected as follows. For example, the inclination angle of the gas inflow pipe and the gas outflow pipe is not limited to 5 degrees, but can be arbitrarily selected within the range of 40 to 80 degrees for the gas inflow pipe and the vertical line, respectively. If the inclination angle of the gas inlet pipe is less than 40°, the arc will be unstable; if the inclination angle is 9806 or more, the gas flow will not be smooth.In addition, if the inclination angle of the gas outlet pipe is less than 40°, the gas flow will be unstable. If the flow is not smooth and the value is 9806 or higher, the arc will become unstable.

Claims (1)

[Claims] Pure metals, metalloids, semiconductors, or alloys are heated and melted by arc in hydrogen or hydrogen-containing gases, or nitrogen or nitrogen-containing gases, and at the same time the hydrogen gas or nitrogen gas is activated. An apparatus for producing ultrafine particles by reacting an activated gas with a melt, which includes (a) a melting chamber equipped with a crucible for storing the melt at the bottom; and (b)
(c) a long electrode member installed obliquely with respect to a horizontal plane, the lower end of which is placed above the melt storage crucible; (c) the lower end of which is connected to the melting chamber and surrounds the electrode member; (e) a gas inflow pipe having two or more layers; (b) a gas outflow pipe whose lower end is connected to the melting chamber at a position substantially opposite to the gas inflow pipe and is installed obliquely with respect to a horizontal plane; An apparatus for producing ultrafine particles, comprising an auxiliary nozzle pipe that penetrates a side surface of the melting chamber, and allows generated ultrafine particles to smoothly flow out of the melting chamber.