JP6709623B2 - Powder reactor - Google Patents

Description

The present invention relates to a powder reactor in which a guide vane is provided inside and a processing container containing a medium ball and powder is rotated at a high speed to convert the powder into fine particles.

A powder reaction apparatus has been developed which has a guide vane inside and rotates a processing container containing a medium ball and powder at high speed to make the powder into fine particles (for example, Patent Documents 1 and 2).

This type of powder reactor is called a converge mill, and as shown in FIG. 3, the converge reactor is a guide fixed to a space with a clearance 16 between the inner wall of the cylindrical processing container 1 and the inside. It has a vane 3. Then, when the powder 21 and the medium balls 23 are housed together in the processing container 1 and the processing container 1 is rotated at high speed, the powder 21 passing through the clearance 16 is attached to the inner wall of the processing container 1 by centrifugal force. To form the powder layer 22, and the medium balls 23 and a part of the powder 21 are changed in direction of movement by the guide vanes 3 and collide with the powder layer 22 on the wall toward the collision portion 24 to form fine particles of the powder. Turn into.

In this converge mill, fine powder (fine particles) having different particle sizes can be obtained by changing the number of rotations of the processing container 1 and the processing time.

The Converge Mill, which atomizes the powder by such a principle or action, can apply the large kinetic energy of the medium ball given by the high-speed rotation of the processing container to the powder in a concentrated and efficient manner as collision energy. In addition, since the contact between the medium ball and the inner wall of the processing container is small, the generation of impurities due to abrasion is small, which is a major feature not found in other reactors.

For this reason, the Converge Mill not only produces fine particles, but also various reactions such as mixed dispersion of the same or different materials (powder) (for example, mechanical milling method (MM method) or mechanical alloying method (MA)). It is expected to be applied to))).

Here, when the MM method or the MA method is performed, since the fine particles during production are activated, a chemical reaction (for example, an undesired oxidation reaction or nitriding reaction) that undesirably changes the quality of the product (unintended purpose) occurs. It needs to be virtually non-existent. Therefore, it is necessary to enclose an inert gas in the processing container or to make it into a fine particle by high vacuum, and to control the intake and exhaust by providing an intake and exhaust system of the inert gas with an airtight structure inside the processing container, It is necessary to evacuate the inside of the processing container until it becomes a high vacuum and atomize it.

Also, since fine powder is handled, it is necessary to keep the oxygen concentration inside the container low in order to eliminate the risk of dust explosion.

However, in order to industrially manufacture alloys and the like, the processing container becomes large, and the amount of the media balls and powders stored in the processing container also becomes large, so the amount of heat generated due to atomization increases. The pressure inside the processing container becomes high. Therefore, since the airtight sealing mechanism, in particular, the penetrating portion of the fixed shaft with respect to the processing container rotating at high speed is a shaft sealing seal against rotation with the processing container rotating at high speed, it becomes difficult to ensure the airtightness of the processing container. There was a problem.

JP 2004-823A Japanese Patent Laid-Open No. 2004-130305 Japanese Patent Laid-Open No. 2008-212025

The present invention has been made in view of the above problems of the prior art, and in the production of a fine particle product, an inert atmosphere inside the processing container is ensured, and under high safety, it is undesired (not intended). It is an object of the present invention to provide a powder reaction apparatus capable of producing a fine particle product that is substantially free from alteration.

In order to solve the above-mentioned problems, a first aspect of the present invention relates to a processing container rotatable around a central axis, a fixed shaft inserted into the inside of the processing container along the central axis, and the fixed shaft. And a guide vane attached to the processing container, the medium ball and the powder are stored inside the processing container, and the powder reaction is configured to atomize the powder by rotating the processing container. The apparatus further comprises a gas introduction flow path for introducing an inert gas into the processing container, and an exhaust flow path for discharging gas inside the processing container, wherein the powder is During the process of making into fine particles, while introducing the inert gas into the inside of the processing container through the gas introduction flow path, by discharging the gas inside the processing container, the inside of the processing container It is characterized in that the atmosphere is an inert gas atmosphere at normal pressure.

A second aspect of the present invention is characterized in that, in the first aspect, the gas introduction passage and the exhaust passage are formed in the fixed shaft.

A third aspect of the present invention is characterized in that, in the first or second aspect, an oxygen concentration meter is provided in an exhaust system including the exhaust passage.

A fourth aspect of the present invention is characterized in that, in any of the first to third aspects, a dust collector is provided in an exhaust system including the exhaust passage.

A fifth aspect of the present invention is characterized in that, in any of the first to fourth aspects, an exhaust system including the exhaust flow passage is provided with an exhaust fan and/or a chimney.

According to the present invention, in the production of a fine particle product, a powder capable of producing a fine particle product substantially free of undesired (unintended purpose) alterations while ensuring an inert atmosphere inside the processing container under high safety. A body reaction device can be provided.

The figure which shows the structure of the powder reactor by one Embodiment of this invention. FIG. 3 is a cross-sectional view showing an inert gas introduction flow path and an exhaust flow path, and a seal structure in the powder reactor shown in FIG. 1. The figure for demonstrating the principle of a converge mill.

Hereinafter, a powder reactor according to an embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the powder reactor according to the present embodiment supplies a reactor 15 having a processing container 1 for accommodating powder and atomizing the powder, and an inert gas into the processing container 1. An inert gas supply system 13 and an exhaust system 14 for exhausting the gas inside the processing container 1 are provided.

<Reactor 15>
The reactor 15 has a cylindrical processing container 1 in which opposite ends on the central axis are closed, and the center of the processing container 1 penetrates through one end of opposite ends on the central axis of the processing container 1. A fixed shaft 2 arranged along the axis, and a guide vane 3 attached to the fixed shaft 2 via a support portion 4 with a clearance 16 from the inner wall of the processing container 1 are provided.

The fixed shaft 2 is supported and fixed by a fixed shaft support portion 17 arranged outside the processing container 1, and a portion arranged inside the processing container 1 supports the guide vane 3 via the support portion 4. .. The processing container 1 is rotated at high speed by a rotating shaft 5 via a power transmission mechanism (not shown) such as a pulley mechanism by an electric motor or the like (not shown) arranged outside.

A bearing 6 for smooth sliding between the fixed shaft 2 and the processing container 1 rotating at high speed, and an atmosphere in the processing container 1 are hermetically sealed in a portion (penetration part) where the fixed shaft 2 of the processing container 1 penetrates. A seal portion 19 for maintaining the above is provided.

The powder reactor according to the present embodiment can perform MA treatment using, for example, a plurality of materials, and when using such a reaction to manufacture a product such as an alloy, high safety is achieved. In order to secure the property and to collect a fine particle product substantially free of undesired (unintended) alteration, it is preferable to make the fine particles of the powder in an atmosphere of an inert gas.

Therefore, the powder reactor according to the present embodiment is configured so that the powder can be made into fine particles in an inert gas atmosphere, and the structure and operating method thereof will be described below.

Prior to starting the operation of the reactor 15, first, the inspection door 20 provided in the processing container 1 is opened, the medium balls and the raw material powder are stored, and the inspection door 20 is closed.

Next, an inert gas such as nitrogen gas or argon gas is introduced into the processing container 1 by the inert gas supply system 13 to make the inside of the processing container 1 an atmosphere of the inert gas. The structure of the penetrating portion of the fixed shaft 2 of the processing container 1 will be described later.

After that, when the processing container 1 is rotated, as shown in FIG. 3, the powder 21 that has passed through the clearance 16 is attached to the inner wall of the processing container 1 by a centrifugal force to form a powder layer 22, and the medium ball 23. A part of the powder 21 has its movement direction changed by the guide vanes 3, and collides with the powder layer 22 on the inner wall of the rotating processing container 1 toward the collision portion 24 to pulverize the powder.

The clearance 16 is set based on the diameter of the medium ball used. Further, by changing the rotation speed of the processing container 1 and the processing time, it is possible to obtain fine powder (fine particles) having different particle diameters. Further, since the powder is made into fine particles and stirred and mixed in an inert gas atmosphere, it is possible to produce an alloy or the like which is substantially free from undesired (unintended purpose) alteration by MA treatment with high safety.

<Structure of Penetration Portion of Fixed Shaft 2 of Processing Container 1>
FIG. 2 is a partially enlarged view of a penetrating portion of the fixed shaft 2 in the processing container 1, which shows a gas introduction flow path 25 and an exhaust flow path 26 of the inert gas in the processing container 1, and the fixed shaft 2 of the processing container 1. It is sectional drawing which shows the structure of a penetration part.

An exhaust passage for linearly penetrating the center of the fixed shaft 2 from the inner end of the processing container 1 to the outer end of the processing container 1 to discharge the inert gas from the inside of the processing container 1 to the outside. 26 are provided. On the other hand, on the outer peripheral side of the exhaust flow passage 26, gas introduction flow passages 25 for introducing the inert gas into the processing container 1 are arranged at several positions in the circumferential direction at appropriate intervals.

Since both the gas introduction flow path 25 for the inert gas into the processing container 1 and the exhaust flow path 26 from the processing container 1 are formed inside the fixed shaft 2 that does not rotate, the gas introduction flow path 25 and the exhaust gas are discharged. A connecting portion such as a pipe of the flow path 26 does not require a rotary joint or the like, and has a simple structure for hermetically sealing the connecting portion.

Regarding the arrangement of the gas introduction flow path 25 and the exhaust flow path 26, conversely to the above, from the outer end of the processing container 1 to the inner end of the processing container 1, at the center of the fixed shaft 2. A gas introduction flow path 25 for linearly penetrating the inert gas from the outside to the inside of the processing container 1 is provided, and is provided on the outer peripheral side of the gas introduction flow path 25 at several positions at appropriate intervals in the circumferential direction. An exhaust passage 26 for discharging the inert gas from the inside of the processing container 1 to the outside may be provided.

As for the penetrating portion of the fixed shaft 2 of the processing container 1, a seal portion 19 is arranged on the inner side of the processing container 1 and a (rotating) bearing 6 is arranged on the outer side thereof, and the seal portion is arranged on the inner side. The airtightness of the processing container 1 is maintained by 19.

The inert gas is introduced from the inert gas supply system 13 into the processing container 1 at a normal pressure or a positive pressure close to it and/or a predetermined flow rate, and the processing container 1 is an exhaust system 14 which is always open to the atmosphere. It is connected to the. With such a configuration, the processing container 1 has a very large volume as compared with the flow passage cross-sectional area of the gas introduction flow passage 25, and is always open to the atmosphere, so that the inert gas is processed at a slightly high positive pressure. Even if it is introduced into the container 1, the pressure of the inert gas as soon as it is introduced into the processing container 1 becomes normal pressure.

As described above, since the pressure of the inert gas inside the processing container 1 is normal pressure, the differential pressure between the both sides of the seal portion 19 is small, and the sealing property against high pressure such as when used in a high-pressure processing container is low. It is not necessary and a sealing mechanism similar to that used in a normal atmospheric pressure treatment container, for example, a sealing mechanism using a sealing material such as an oil seal is sufficient.

The predetermined value such as the flow rate of the inert gas introduced into the internal space of the processing container 1 is set based on the result obtained in advance by a preliminary test or the like.

Further, in order to prevent the outside air from flowing into the processing container 1 from the sealing part 19 due to the deterioration of the airtightness of the sealing part 19, it is preferable that the gas pressure in the processing container 1 is a normal pressure on the positive pressure side. Further, the gas pressure in the processing container 1 also depends on the flow resistance and the suction force in the exhaust system 14. Therefore, by setting the pressure in the processing container 1 to the positive pressure side, the power consumption of the exhaust fan 10 and the like are reduced. May contribute to.

When the temperature inside the processing container 1 rises due to the heat generated by the atomization and the pressure of the inert gas is about to rise, the exhaust system 14 is open to the atmosphere. Due to the increase in the differential pressure from the environment, the flow rate of gas discharged by the exhaust system 14 increases in conjunction with the increase in the gas pressure in the processing container 1 is suppressed. That is, in the configuration of the present embodiment, the gas pressure in the processing container 1 can be increased by a simple configuration without providing a complicated or advanced feedback control system that constantly controls the pressure in the processing container 1. It has the feature that it can be suppressed.

As described above, with the configuration of the present embodiment, the gas pressure in the processing container 1 can be suppressed within the normal pressure range even when the temperature in the processing container 1 is about to rise due to the heat generated by atomization. The sealing portion 19 needing a normal airtight seal is the same as when there is no internal heat generation.

<Inert gas supply system>
The inert gas supply system 13 includes an inert gas supply source 7 and a reduced pressure flow meter 12, and continuously introduces the inert gas into the processing container 1 during the operation of the apparatus. The inert gas supply source 7 is, for example, a gas cylinder of argon gas or nitrogen gas. The depressurization flow meter 12 is provided in a pipe immediately before the connecting portion of the processing container 1 or the like, and adjusts the gas pressure of the inert gas introduced into the processing container to a set pressure.

<Exhaust system>
The exhaust system 14 has the dust collector 9 and the exhaust fan 10 arranged in this order, and the exhaust port of the exhaust fan 10 is always open to the atmosphere to maintain the gas pressure in the processing container 1 during operation at normal pressure. Is.

The dust collector 9 collects the powder or fine particles that flow out together with the inert gas discharged from the processing container 1 by the dust collector 9 arranged upstream of the air exhauster 10. For example, the dust collector 9 equipped with a bag filter is used. Can be used.

The air blower 10 has a large flow resistance in the piping of the exhaust system 14 and in the dust collector 9, and in particular, the pressure increase in the processing container 1 due to the heat generation during the atomization processing causes only the differential pressure between the processing container 1 and the external environment. When the discharge flow rate that can maintain the gas pressure in the container 1 at the normal pressure cannot be secured, it is arranged to forcibly secure the discharge flow rate. Therefore, when the flow resistance in the pipes and the dust collector 9 in the exhaust system 14 is small and the gas pressure in the processing container 1 can be maintained at normal pressure due to the differential pressure between the processing container 1 and the external environment, the exhaust fan 10 is omitted. You can turn on or stop the operation.

The flow rate of the exhaust gas is basically maintained at a normal pressure in the processing container 1 by discharging the gas at a flow rate corresponding to the gas flow rate introduced into the processing container 1 from the inert gas supply system 13. Therefore, the discharge flow rate can be reduced by reducing the flow rate of the gas introduced into the processing container 1, and the energy consumption can be small even when the blower 10 is operated.

Further, the length (height) of the exhaust port 27 of the exhaust fan 10 is increased, or a chimney is provided at the exhaust port 27 to increase the suction power, thereby reducing the power consumption of the exhaust fan 10. Can be made Further, depending on the suction force required for the exhaust system 14, a chimney having an appropriate height may be provided instead of the exhaust fan 10. In particular, when the gas temperature in the processing container 1 rises due to heat generation due to atomization, the suction force due to the chimney effect increases, so when the heat generation in the processing container 1 is large, the effect of the chimney arrangement is effective. It is preferable that the chimney is improved because it is inexpensive and maintenance costs such as power consumption are unnecessary.

After the atomization, the flow rate of the introduced gas into the processing container 1 by the inert gas supply system 13 is increased and the flow rate of the exhaust gas from the exhaust fan 10 is increased to remove the fine particles produced in the processing container 1. The exhaust gas can be forcibly recovered by the dust collector 9.

The exhaust system 14 is further provided with an oxygen concentration meter 8 upstream of the dust collector 9. A filter 11 is provided on the upstream side of the oxygen concentration meter 8. By providing the oxygen concentration meter 8 in this manner, when the outside air flows into the processing container 1 due to a leak of the seal portion 19 or a backflow occurs in the exhaust system 14, an inert gas in the processing container 1 is generated. Can be monitored for abnormalities in the atmosphere.

When the oxygen concentration detected by the oxygen concentration meter 8 reaches a predetermined concentration, the operation can be stopped and other necessary measures can be taken. The predetermined oxygen concentration for determining the occurrence of an abnormality may be based on, for example, the explosion limit oxygen concentration of the processing raw material that does not cause dust explosion.

1 Processing Container 2 Fixed Shaft 3 Guide Vane 4 Supporting Part 5 Rotating Shaft 6 Bearing 7 Inert Gas Supply Source 8 Oxygen Concentration Meter 9 Dust Collector 10 Exhaust Fan 11 Filter 12 Reduced Flow Meter 13 Inert Gas Supply System 14 Exhaust System 15 Reactor 16 clearance 17 fixed shaft support 18a, b bolt 19 seal 20 inspection door 21 powder 22 powder layer 23 medium ball 24 collision part 25 gas introduction flow path 26 exhaust flow path 27 exhaust port

Claims (5)

A processing container rotatable around a central axis, a fixed shaft inserted through the inside of the processing container along the central axis, and a guide vane attached to the fixed shaft, and inside the processing container. A powder reaction apparatus which is configured to store a medium ball and powder and to atomize the powder by rotating the processing container,
A gas introduction flow path for introducing an inert gas into the inside of the processing container,
Further comprising an exhaust flow path for exhausting gas inside the processing container,
During the process of making the powder into fine particles, while introducing the inert gas into the inside of the processing container through the gas introduction flow path, and discharging the gas inside the processing container, the processing A powder reaction apparatus configured so that the inside of the container is in an atmosphere of an inert gas at normal pressure. The powder reaction device according to claim 1, wherein the gas introduction flow path and the exhaust flow path are formed on the fixed shaft. The powder reactor according to claim 1, wherein an oxygen concentration meter is provided in an exhaust system including the exhaust flow path. The powder reactor according to any one of claims 1 to 3, wherein a dust collector is provided in an exhaust system including the exhaust passage. The powder reactor according to claim 1, wherein an exhaust system and/or a chimney is provided in an exhaust system including the exhaust passage.

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