KR100386896B1 - apparatus for producing fine powder from molten liquid by high-pressure spray - Google Patents

Abstract

The present invention provides an apparatus for producing metal powder from a molten metal that can be finer by a rotating disk while directly atomizing the molten liquid droplets to obtain a fine powder with a narrower particle size distribution, and can prevent agglomeration of scattered particulate droplets. to provide.

The production method taps the molten metal through the molten nozzle 9 of the tundish 1c onto the rotating disk 8 which is rotated by the high speed rotating means 2 and at the same time near the outlet of the molten nozzle 9. In the metal powder manufacturing method for producing fine powder by forming a fine droplet fine particles by injecting the gas to the rotary disk 8 side at a high pressure through the gas injection nozzle means (50, 52, 56) at least, The sprayed gas is heated and sprayed by the heating device 51 at a high temperature close to the melting point so as to maintain a liquid state that can be refined. After colliding with the rotating disk 8, the droplet fine particles scattered are rotated. The third rotating disk 63 which collides with the second rotating disk 61 at the outer side of the opposite side of 8) and rotates droplets scattered downward from the second rotating disk 61 at the outer circumference of the rotating disk 8. By colliding Prevent agglomeration of fine particles and enemy is characterized in that the further miniaturization.

Description

Apparatus for producing fine powder from molten metal {apparatus for producing fine powder from molten liquid by high-pressure spray}

The present invention relates to an apparatus for producing metal powder from molten metal. More particularly, the fine powder having a narrower particle size distribution can be obtained by further minimizing the molten liquid droplets by the rotating disk while directly atomizing the molten liquid droplets. The present invention relates to an apparatus for producing metal powder from a molten metal capable of preventing agglomeration of droplets.

Conventionally, when manufacturing metal powder from the molten metal, a high-speed fluid is continuously blown into the molten metal to be melted, and the atomization is performed by a water spray method or a gas spray method that atomizes the metal molten metal using the shearing force, and the centrifugal force of the high-speed rotating cup or disc. Centrifugal spraying is mainly used. In these methods, the raw metal was melted in advance to form a molten metal, and then powder was obtained by atomizing using a shear force of a high speed fluid and a centrifugal force of a high speed rotor. The same applies to ceramics.

However, in this case, the average particle diameter of the powder produced shows a direct correlation with the molten metal supply amount per unit time to the metal atomization means, and when the supply amount is large, the average particle size of the powder becomes large. The particle size becomes smaller. Therefore, in order to solve the problem that the particle size distribution is widened due to fluctuation of the tapping amount, and the overall yield is lowered, the present inventors, the tapping amount from the initial stage of manufacture of the metal (including ceramic) powder to the final stage of manufacture Provides a molten metal atomization device that makes the average particle size distribution nearly constant as possible, and also installs a melting furnace that can melt and continuously melt the material to improve productivity. It has been invented and filed with a molten metal atomization device as shown in Figure 1, to build a system that can be exchanged automatically if.

In Fig. 1, the atomization apparatus is largely comprised of four parts: the spray tank 1, the atomization means 2, the continuous tapping apparatus 3, and the powder collection bottle 4. The continuous tapping apparatus 3 is composed of a main melting furnace 1a, an auxiliary melting furnace 1b, and a tundish 1c, and each of the main melting furnaces 1a and the auxiliary melting furnace 1b has an outflow control means 5, 5a, 7a, 7b) are provided. The outflow control means 5, 5a, 7a, 7b includes, for example, a pneumatic cylinder 5 which allows the piston rod 5a to move up and down on each of the upper portions of the main melting furnace 1a and the auxiliary melting furnace 1b. It is installed and can be configured to adjust the respective tapping amount by controlling the stoppers 7a and 7b connected to the piston rod 5a. It also has a vacuum seal to prevent the inflow of external air. One conduction sensor (6a) is installed in the main melting furnace (1a), and a buzzer (not shown) is provided to automatically inform the re-injection melting time when there is no molten metal, and two conduction sensors are installed in the auxiliary melting furnace (1b). Is installed. One of the upper limit sensors 6b is installed for the purpose of controlling the upper limit line of the molten metal of the auxiliary melting furnace 1b, and when the upper limit sensor 6b is detected, the stopper 7a of the main melting furnace 1a is lowered. Supply of the molten metal from the melting furnace 1a to the auxiliary melting furnace 1b is interrupted. In addition, the lower limit sensor 6c is installed for the purpose of determining when the molten metal is supplied from the main melting furnace 1a, and is configured to lift the stopper 7a of the main melting furnace 1a upward to receive the molten metal upon detection.

Two conducting sensors are also provided in the tundish 1c to maintain the molten liquid level in a similar manner as described above. Accordingly, the upper limit sensor 6d blocks the supply of the molten metal from the auxiliary melting furnace 1b. The stopper 7b of the auxiliary melting furnace 1b is lowered, and the lower limit sensor 6e is configured to raise the stopper 7b of the auxiliary melting furnace 1b to start the melt supply.

In addition, the spray tank 1 becomes a working initial vacuum by the vacuum pump 21 of the vacuum system 20, and is filled with inert gas or reducing gas by the inert (reducible) gas supply device 30. As shown in FIG. In addition, when the oxygen sensing means 16 senses a large amount of oxygen, the vacuum system 20 causes the spray tank 1 to be vacuumed, and from the inert (reducing) gas supply device 30 to the inert gas or the like. Reducing gas is supplemented and filled.

The metal powder produced in this way starts to accumulate in the powder collection bottle 4 located under the disk. The collection bottle automatic exchange devices 12, 13, 14, and 15 are installed in the powder collection bottle 4 to automatically exchange the empty powder collection bottle 4 when the metal powder is collected by a certain height. The collection bottle automatic changer (12, 13, 14, 15) is, for example, a position sensor 6f, a flat valve 11, a guide chuck 12, a positioning means 13, and an air cylinder 14, 15. It is configured to include).

The invention thus constructed can achieve a narrow particle size distribution and increase productivity, but still does not further refine the powder, and furthermore does not prevent the aggregation of scattering droplet fine particles.

In addition, the atomization apparatus and method disclosed in U.S. Patent No. 5,855,642, using an electrode on one side while rotating the metal rod to generate an arc and melt it to spray the melt ejected in the centrifugal direction at high pressure to scatter fine particles and cool. The fine particles are further formed by injecting a gas at a high pressure into the particulate droplets scattered by centrifugal force while solidifying to form a powder or flowing a melt on a rotating disk to form a film.

However, in the US patent, when using a metal rod as an electrode, it is difficult to obtain a uniform arc, so that the particle size distribution of the fine particle droplets is wide, and further, the particle size distribution of the fine particle droplets that cannot be prevented can not be prevented. There is a problem of contamination, and in the case of using a rotating disk, the droplets scattered from the rotating disk have to be in a liquid state in order to further refine, and thus, the rotating disk needs to be maintained at a high melting temperature. There is a problem that it does not prevent aggregation.

The present invention is to solve the above-mentioned problems, to directly finer the molten liquid droplets and to finer by the rotating disk to obtain a finer powder of a narrower particle size distribution, to prevent the aggregation of scattered particulate droplets It is an object of the present invention to provide an apparatus for producing metal powder from molten metal.

1 is a schematic configuration diagram showing the configuration of a molten metal atomization device according to the present invention;

2A is a schematic configuration diagram showing the construction of a metal powder production apparatus from a molten metal according to the present invention;

Figure 2b is a partial cross-sectional view showing in detail the configuration of the high-pressure gas injection nozzle of Figure 2a,

Figure 2c is a partial cross-sectional view showing an example of the structure in which the gas injection nozzle is formed integrally with the molten nozzle;

Figure 2d is a partial cross-sectional view showing another example of the structure in which the gas injection nozzle is formed integrally with the molten nozzle;

2E is a plan view showing the shape and arrangement of the nozzle hole of the molten nozzle and the nozzle hole of the gas injection nozzle;

Figure 3a to Figure 3b is a schematic diagram showing the configuration of the molten metal atomization apparatus according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

1: spray tank 1a: main furnace

1b: secondary melting 1c: tundish

2: high speed rotation means 3: continuous tapping device

4: powder collecting bottle 5: pneumatic cylinder

5a: piston rod 6a: conduction sensor

6b, 6d: Upper limit sensor 6c, 6e: Lower limit sensor

6f: Position sensor 7a, 7b: stopper

8: rotating disk 9: molten nozzle

10: Material Inlet 11: Flat Valve

12: guide chuck 13: positioning means

14, 15: air cylinder 16: oxygen detection means

17: height sensing means 18: temperature sensing means

20: vacuum system 21: vacuum pump

30: inert gas reducing device 50: air spray nozzle

51: heating device 52, 56: gas injection nozzle ball

53: static pressure chamber 54: adapter

55: gas supply pipe 61: second rotary disk

62: second high speed rotating means 63: third rotating disk

64: third high speed rotation means

Metal powder production method from the molten metal related to the present invention for achieving the above object, the molten metal through the melt nozzle of the tundish on the rotating disk rotated by a high-speed rotating means and at the same time exit of the melt nozzle In the metal powder manufacturing method for producing fine powder by injecting the gas to the rotating disk side at high pressure through the gas injection nozzle means in the vicinity, at least the molten metal is maintained in a liquid state that can be refined at least The sprayed gas is heated and sprayed by the heating apparatus at a high temperature close to the melting point, and after colliding with the rotating disk, the flying droplet fine particles collide with the second rotating disk on the outer side of the rotating disk. Third rotation for rotating droplets scattered downward from the second rotating disk at the outer circumference of the rotating disk It is characterized by preventing colliding of droplet fine particles and further minimizing by colliding with the disk and scattering.

In addition, the present invention is a molten metal nozzle of the tundish for tapping the molten metal, a rotating disk which is installed at the position where the molten metal is dropped to form fine droplet fine particles, and rotated by a high-speed rotating means, and the molten metal In the metal powder manufacturing apparatus comprising a gas injection nozzle means for injecting the gas to the rotating disk side at a high pressure near the outlet of the nozzle, the high temperature close to the melting point to maintain the liquid state that the molten metal is refined A heating device for heating the sprayed gas, and colliding droplet fine particles scattered after colliding with the rotating disk to prevent collision and further refinement of the droplet fine particles scattered from the rotating disk. The second rotating disk provided outside the opposite side of the rotating disk, and the second time A third rotating disk installed on the outer periphery of the rotating disk to collide and scatter the droplets scattered downward from the disk, the rotating disk, the second rotating disk, the third rotating disk, a melt nozzle of the tundish, and a gas spray nozzle It provides a device for producing metal powder from the molten metal, characterized in that it comprises a means and a spray tank surrounding the space in the scattering range of the droplet fine particles from the third rotating disk, and maintained in an inert to reducing atmosphere.

The shape of the nozzle hole of the gas injection nozzle may be variously changed as a fine orifice hole, and the melt nozzle may also have a circular cross section as in the prior art. It is also possible to let them out.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2A to 2E show a metal powder production apparatus from the molten metal according to the present invention, and the same configuration as in FIG. 1 is as described above.

2A and 2B, a gas injection nozzle 50 is provided for enclosing the molten nozzle 9 and for injecting a high pressure gas from the periphery thereof. The gas injected from the gas injection nozzle 50 is preferably an inert or reducing gas so as not to contaminate the droplets. Furthermore, the injected gas is heated close to the melting point of the melt so that the temperature can keep the droplets in a liquid state. It is preferable to provide the heating apparatus 51 for making it.

In this way, by injecting gas into the droplets falling by the gas injection nozzle 50, the fine particles of finer particles collide with the rotating disk 8 at high speed.

The droplet fine particles colliding with the rotating disk 8 are further atomized and scattered by the rotating centrifugal force of the rotating disk 8 together with the collision force.

In addition, it is preferable that the constant pressure chamber 53 is formed as shown in FIGS. 2b to 2c so that the gas injected from the above-described gas injection nozzle 50 can be injected at a uniform pressure and flow rate from each nozzle hole. The shape or arrangement of the gas injection nozzle hole will vary depending on the shape or arrangement of the melt nozzle 9, but as an example, as shown in FIG. 2E, the melt nozzle 9 is circular or rectangular, The gas injection nozzle 50 is formed by the nozzle hole of. In this case, the gas supply pipe 55 is connected to the molten metal nozzle 9. In addition, when the static pressure chamber 53 is provided, it will be convenient for assembly or manufacturing to fix the gas supply pipe 55 via the adapter 54 for processing.

In FIG. 2C and FIG. 2D, gas injection nozzle holes 52 and 56 are integrally formed in the molten metal nozzle 9. The position and quantity of the gas injection nozzles 52 and 56 can be changed in various ways. In FIG. 2C, the gas injection nozzle holes 52 are formed toward the outlet of the molten nozzle 9, but in FIG. It is formed just before the exit of the nozzle (9).

In addition, the gas injected from the gas injection nozzle means (50, 52, 56) may be continuously injected, and is injected immediately before or immediately after falling from the molten nozzle (9) by the opening and closing means or reciprocating pressure means, the liquid It may be configured to inject gas every cycle in which the enemy is formed. In this case, it is also possible to adjust the rotation speed of the motor for a high pressure compressor to match discharge pulsation with the period.

3A and 3B show an apparatus for producing metal powder from a molten metal according to an embodiment of the present invention.

In FIG. 3A and FIG. 3B, the 2nd rotating disk 61 and the 3rd rotating disk 63 are installed in the outer periphery of the molten metal nozzle 9 and the rotating disk 8. As shown in FIG. The second rotating disk 61 is preferably fixed to the same support for supporting the rotating means of the rotating disk 8 and is fixed to the rotating means 62 in which the outer ring rotates and rotates together. It is preferable that the third rotating disc 63 is configured so as not to be an obstacle of the droplet fine particles scattered by being connected to the rotor of the rotating means 63 supported upwardly. A fluid turbine motor is considered as the rotation means 62 and 63. The fluid turbine motor is rotated by an inert gas or a reducing gas containing only a small amount of oxygen rather than air, while maintaining an inert atmosphere or a reducing atmosphere, It would be desirable to promote surface coagulation of the droplet microparticles being scattered and to prevent coagulation with each other.

By such a configuration, the droplet fine particles that collide and collide with the rotating disk 8 firstly collide with the second rotating disk 61 and the third rotating disk 63 to be scattered, thereby causing aggregation between the droplet fine particles. This can be prevented and further refined.

In particular, when the second rotary disc 61 and the third rotary disc 63 are installed together with the configuration of FIGS. 2A to 2D, the liquid state is dispersed by the gas injected and the gas heated to a high temperature. Since it can be maintained for a longer time, even when the centrifugal force is applied to the second rotating disk 61 and the third rotating disk 63, the already atomized droplets can be further atomized to form a very fine powder.

On the other hand, it is preferable that the constant pressure holding valve is installed to prevent the pressure in the spray tank 1 from rising by the gas injection nozzle means 50, 52, 56 being introduced at high speed and high pressure ( In the conventional configuration, since such a constant pressure holding valve is used for other purposes, it does not need to be employed separately in this case).

In the above embodiment, although the present invention is shown and described by applying the present invention to the configuration of FIGS. 1 to 2A, the shearing force and the centrifugal force on the rotating disk 8 by the high-speed rotating means in an inert or reducing atmosphere even in the configuration different from FIG. The present invention can be applied to the configuration of preparing the fine powder by atomizing and solidifying the molten metal is melted through the molten metal nozzle using, and may be changed in various ways depending on the shape, sphericity, distribution of particle size, etc. .

For example, the shape of the powder may be spherical powder, or the formation of a flat flaky powder may include a gas injection pressure, a rotational speed of the rotating disk 8 and a shape of an upper surface, a drop of droplets, and a gas injection. Is determined by the relationship between the relative position (collision position) and the rotating disk (8).

According to the configuration and operation of the metal powder manufacturing apparatus from the molten metal according to the embodiments of the present invention described above, the gas injection nozzle means (50, 52, 56), the second rotating disk 61 and the third rotating disk Providing (63) has the effect of preventing finer agglomeration and obtaining powders of various shapes as well as narrower particle size distribution.

Claims (4)

delete delete delete Rotating disk which is installed at the position where the molten metal nozzle 9 of the tundish 1c for tapping the molten metal and the molten metal which are dropped out to form fine droplet fine particles fall, and are rotated by the high speed rotation means 2 ( 8) and gas injection nozzle means (50, 52, 56) for injecting gas toward the rotary disk (8) at high pressure near the outlet of the molten nozzle (9). , The heating device 51 for heating the injected gas to a high temperature close to the melting point to maintain the liquid state in which the melted molten metal can be refined, and the droplet fine particles scattered from the rotating disk (8) to fine particles A second rotating disk 61 installed outside the opposite side of the rotating disk 8 so as to collide with the rotating disk 8 after colliding with the rotating disk 8 so as to prevent agglomeration of these particles and to make it more fine; And a third rotating disk 63 installed on the outer circumference of the rotating disk 8 so as to collide and scatter droplets scattered downward from the second rotating disk 61, the rotating disk 8 and the second. Droplet fine particles from the rotary disk 61, the third rotary disk 63, the melt nozzle 9 of the tundish 1c, the gas injection nozzle means 50, 52, 56 and the third rotary disk 63; Surrounds the space in the scattering range of the And a constant pressure chamber 53 for injecting gas at a uniform pressure and flow rate, wherein the gas injection nozzle means is immediately before falling from the molten nozzle 9. It is composed of a gas injection nozzle hole 56 formed by connecting the gas supply pipe 55 to the molten nozzle 9 so as to inject gas from an adjacent position in the outlet of the molten nozzle 9 at every cycle in which the droplets are formed. An apparatus for producing metal powder from molten metal.