JPS6052502A - Apparatus for producing fine particle - Google Patents

Abstract

PURPOSE:To produce continuously fine particles in large amt. by rotating a rotating body under non-contact state at a high speed in a vessel and spraying the molten material supplied into the vessel by centrifugal force. CONSTITUTION:A prescribed voltage is impressed from a floating control circuit 4 to a solenoid 3 for floating so that the solenoid 3 generates a floating magnetic field. On the other hand, the pulse voltage of a prescribed number of pulses is impressed to a coil 5 for rotation from a rotation control circuit 6 so that the respective coils 5B, 5D generate respectively two phases rotary magnetic fields. The body 2 floats and rotates at a high speed. The molten metal in a molten metal tank 7 is ejected via a tube 8 from the nozzle port 8A thereof toward the receiving surface 2A of the body 2. The molten metal is diffused like a thin film toward the radial direction by the centrifugal force of the body 2 and is sprayed in the form of fine metallic particles from a releasing end edge 2B toward the radial direction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fine particle manufacturing apparatus suitable for manufacturing metal fine particles, ceramic fine particles, plastic fine particles, etc. (hereinafter referred to as "metal fine particles").

Recently, metal particles have been used in capacitor electrodes, conductive rubber materials,
Across various industrial fields as catalysts, magnetic tapes, etc.
That use is expected.

Various types of metal particle manufacturing equipment have been proposed for use in these processes, including evaporation methods, ultrasonic pulverization methods, and electrical discharge precipitation methods. It has been put into practical use.

That is, in the evaporation method, a crucible tube is placed in a vacuum container equipped with an evacuation system and an inert gas, a high-frequency induction coil is installed around the crucible, and a fine powder collection chamber is placed above the vacuum container. The metal gold in the crucible is evaporated by high-frequency heating in an inert gas atmosphere, and as it collides with the inert gas in the tube container, it is gradually cooled down and floated to the fine powder collection chamber in the form of smoke. The particles adhering to the fine powder collection guide wall are collected as fine metal particles.

However, the metal fine particle manufacturing device using the evaporation method described above,
Since the metal in the crucible is evaporated by high-frequency heating, the method that produces a large amount of fine metal particles has the disadvantage of poor productivity. Furthermore, since the process is manufactured under vacuum conditions while introducing an inert gas, there is a drawback in that it is very difficult to recover fine powder during continuous operation.

The present invention has been made in view of the drawbacks of the prior art described above.
It is an object of the present invention to provide a fine particle manufacturing apparatus capable of continuously manufacturing a large amount of fine particles of metal, plastic, etc. having a uniform particle size.

In order to achieve the above object, the present invention provides a container made of a magnetically permeable material, a flotation solenoid provided on the outside of the bottom of the container, and a rotating solenoid provided on the outside of the peripheral wall of the container. a coil, 8t''L made of a magnetic material, levitated into the container by the levitation solenoid and rotated at high speed by the rotational coil;
By supplying the molten material to the rotating body, which is suspended at high speed, the centrifugal force of the rotating body causes the molten material to become fine particles toward the inner wall of the container. The reason is that it is configured to spray.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on examples shown in the drawings, taking as an example the case of producing metal fine particles.

In the drawings, reference numeral 1 denotes a container made of a magnetically permeable material placed on a base or the like, and the container 1 has a conical shape with a bottom that expands upward. 2 is the trap length f'l2f in container 1
c A rotating body made of magnetic material. The rotating body 2 has a plate-shaped or disk-shaped cross section as shown in Figure @1, and its inner periphery has two concave receiving surfaces, and its edges ifI
The discharge edge 2B has a knife-like shape that expands slightly upward, and the discharge edge 2B has a large number of V-shaped grooves carved therein as required.

Reference numeral 3 denotes a flotation solenoid disposed outside the bottom of the container 1, and the solenoid 3 is constructed by winding a coil 3B around the outer periphery of a soft iron core 3A. Reference numeral 4 denotes a levitation control circuit for supplying a predetermined voltage to the coil 3B of the solenoid 3 to control the levitation of the rotating body 2. By supplying a predetermined DC voltage from the control circuit 4 to the solenoid 3, a levitation magnetic field is generated. The magnetic field has the function of transmitting through the container 1 and levitating the rotating body 2.

5A, 5B, 5C, and 5D are arranged on the outside of the peripheral wall of the container 1.
For example, the coils 5 are rotating coils such as air coils (collectively referred to as "rotating coils 5"), and the coils 5 include coils 5A, 5C, and 5B.

5D are connected in series. Reference numeral 6 denotes a rotation control circuit that controls the rotation of the rotating body 2 by outputting pulse voltages having a phase difference of 90 degrees, for example, to the rotation coil 5, and the rotation control circuit 6 supplies coils 5A, 5C, and 5B.
, 5D and 5D, a rotating magnetic field is generated in the same manner as an induction motor or a synchronous motor by supplying two-phase pulse voltages with different phases such as -90° or 00 and +90°, and the rotating body 2 is moved to a predetermined position. It can rotate at high speeds.

Further, 7 is a molten metal tank placed above the container 1, for example, for storing molten metal, and the metal tank 7 has a function of melting the metal by means such as high frequency heating and storing the metal. 8 is a nozzle port 8 whose one end is connected to the molten metal tank 7 and whose other end is opened above the rotating body 2 in the container 1.
(5) A tube for supplying molten gold maple, and the tube 8 is composed of, for example, a thermal tube having a heat insulating effect.
The molten metal in the molten metal tank 7 can be continuously discharged or ejected little by little toward the two receiving surfaces of the rotating body 2.

Reference numeral 9 denotes a tube for recovering metal particles, one end of which opens into the bottom of the container 1, and the other end connected to a recovery tank 10 to recover metal particles that have fallen to the bottom of the container 1. It looks like this.

Further, reference numeral 11 denotes an annular coolant outflow pipe disposed at the upper end of the opening side of the container 1, and a large number of streams are provided at the inner lower part of the outflow pipe 11 so that all of the coolant flows out toward the inner wall of the container 1. Exit] IA, 11A,.

...is having a puncture. 12 is a liquid tank, 13 is a tube for cooling liquid distribution, and one end of the tube 13 is connected to the liquid tank 12.
The other end is connected to the coolant outflow pipe 11.

The present invention is constructed as described above, and its operation will be described next.

First, the rotating body 2 is heated in advance to a predetermined temperature so that the molten metal does not receive thermal shock when it comes into contact with the rotating body 2.

Next, a predetermined voltage is applied from the levitation control circuit 4 to the levitation solenoid 3 to cause the solenoid 3 to generate a levitation magnetic field. On the other hand, a predetermined number of pulse voltages are applied from the rotation control circuit 6 to the rotating coil 5 to generate a two-phase rotating magnetic field in each of the coils 5A, 5C, 5B, and 5D.

Next, the rotating body 2 is placed in the container 1 containing the heated rotating body 2 heated as described above, and the rotating body 2 is levitated into the container 1 by the levitation magnetic field and rotated by the rotating magnetic field. At this time, in order to increase the centrifugal force exerted by the rotating body 2, the rotating body 2 is rotated at a high speed, for example, at 10,000 to 500,000 rpm.

Furthermore, the molten metal stored in the molten metal tank 7 is discharged or ejected from the nozzle port 8A7) through the tube 8 toward the receiving surface 2A of the rotating body 2.

As a result, due to the centrifugal force of the rotating body 2, the molten metal is diffused into a thin film in the radial direction between the two receiving surfaces, and is sprayed in the radial direction as fine metal particles from the discharge edge 2B. At this time, since the coolant in the liquid tank 12 is to flow out in small quantities toward the inner wall of the container 1 from the outlet 11A of the annular coolant outflow pipe 11 via the tube 13, the rotation is performed as described above. The metal fine particles sprayed from the body 2 come into contact with the cooling liquid flowing down on the inner wall of the container 1, form a cooling field, and flow down to the bottom of the container 1 together with the cooling liquid. Then, the metal particles in the container 1 are collected together with the cooling liquid into the collection tank 10 via the tube 9. Thereafter, the metal fine particles are transferred together with the cooling liquid in the recovery tank 10 to a drying tank, and the cooling liquid is evaporated, thereby obtaining dry metal fine particles.

Thus, by continuously supplying molten metal to the rotating body 2 while rotating the rotating body 2 at high speed, metal fine particles can be continuously produced. Further, by appropriately controlling the rotational speed of the rotating body 2, controlling the supply amount of molten metal, etc., the particle size distribution can be controlled, and extremely homogeneous metal fine particles can be obtained. Furthermore, since the rotating body 2 is floated and rotated in a non-contact state within the container 1, it is not subjected to any resistance force other than air resistance, and extremely high-speed rotation can be obtained. Fine particles can be produced.

In addition, in the above-mentioned embodiment, the cooling liquid was used as a means for cooling the metal particles, but the cooling liquid may be used as necessary, and the cooling liquid may be sprayed from the rotating body 2,
Coolant may be unnecessary if the aircraft is exposed to air during flight to provide a cooling field. On the other hand, an inert gas can be used instead of air as the atmosphere in which the rotating body 2 exists, and it is preferable to use an inert gas when producing fine particles of combustible metal such as aluminum at one time. In addition, in order to stably rotate the posture of the rotating body 2, it is better to use an air core coil as the coil 5, but depending on the desired rotation accuracy and balance accuracy, it is not limited to an air core coil, and a magnetic material may be used. A solenoid coil having a core may also be used. Furthermore, the molten material is not limited to molten metal, and other materials that are solid at room temperature, such as ceramics, resin materials, and plastic materials, may also be used.
9) In short, it only needs to be able to produce fine particles in a molten state. Furthermore, in order to prevent the rotating body 2 from being cooled and to keep it warm continuously, a heating source may be disposed above the container 1 to continuously heat the rotating body 2, for example.

The apparatus for producing fine particles according to the present invention is as described in detail above, and the rotating body is rotated at high speed in a non-contact state in a container, and the supplied molten material fL'fc is sprayed using centrifugal force. , configured to be able to produce atomized particles'
Fine particles can be produced continuously and in large quantities from fc. In addition, by rotating the rotating body at high speed and discharging the molten material from the nozzle opening in a spraying manner toward the rotating body, thinning of the film is further promoted. This provides effects such as being able to produce ultrafine particles.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing a fine particle manufacturing apparatus according to the present invention, and FIG. 2 is a plan view of FIG. 1. DESCRIPTION OF SYMBOLS 1... Container, 2... Rotating body, 3... Levitation solenoid, (10) 4... Levitation control circuit, 5... Rotating coil, 6...
・Rotation control circuit, 7... Molten metal tank, 8.9.13・
...Tube, 10... Recovery tank, 11... Coolant outflow pipe, 12... Liquid tank. (11)

Claims (1)

[Claims] A container made of a magnetically permeable material, a solenoid for levitation provided on the outside of the bottom of the container, a coil for rotation provided on the outside of the peripheral wall of the container, and a field made of a magnetic material. a rotating body for atomizing the molten material, which is floated in the container by a solenoid and rotated at high speed by the rotating coil. A fine particle manufacturing apparatus configured to supply a material and spray the material as fine particles toward the inner wall of the container by the centrifugal force of the rotating body.