JP2017124354A - Powder reaction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a particulate product substantially nonexistent in undesired deterioration (except for an object), under high safety, by securing an inert atmosphere inside of a treatment container, in manufacture of the particulate product.SOLUTION: The prevent device is a powder reaction device for atomizing powder by rotating a treatment container 1 for storing the powder and a medium ball, and comprises a gas introduction flow passage 25 for introducing inert gas into the inside of the treatment container 1 and an exhaust flow passage 26 for discharging gas inside of the treatment container 1. In treatment for atomizing the powder, inert gas is introduced into the inside of the treatment container 1 via the gas introduction flow passage 25, and the inside of the treatment container 1 is constituted so as to be put in an inert gas atmosphere of atmospheric pressure by discharging the gas inside of the treatment container 1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a powder reaction apparatus that includes a guide vane inside and finely pulverizes powder by high-speed rotation of a processing vessel containing a medium ball and powder.

  A powder reaction apparatus has been developed in which a guide vane is provided inside and a powder is made into fine particles by high-speed rotation of a processing vessel containing a medium ball and powder (for example, Patent Documents 1 and 2).

  This type of powder reaction apparatus is called a convergence mill. As shown in FIG. 3, the convergence mill is a guide fixed in a space with a clearance 16 between the inner wall of the cylindrical processing vessel 1. Vane 3 is provided. When the powder 21 and the medium ball 23 are stored together in the processing container 1 and the processing container 1 is rotated at a high speed, the powder 21 that has passed through the clearance 16 adheres to the inner wall of the processing container 1 by centrifugal force. The powder layer 22 is formed, and the movement direction of the medium ball 23 and part of the powder 21 is changed by the guide vane 3, and the powder collides with the powder layer 22 on the wall toward the collision part 24 to make the powder fine particles. Turn into.

  In this convergence mill, fine powders (fine particles) having different particle sizes can be obtained by changing the rotation speed and processing time of the processing container 1.

  Converge mills that pulverize powder based on this principle or action can give the powder a large amount of kinetic energy given by the high-speed rotation of the processing vessel as collision energy in a concentrated and efficient manner. In addition, since there is little contact between the medium ball and the inner wall of the processing vessel, there is a large feature not found in other reactors, such as less generation of impurities due to wear.

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

  Here, when the MM method or the MA method is performed, since the fine particles being produced are activated, there is a chemical reaction (for example, an undesired oxidation reaction or nitridation reaction) that changes the product to an undesired (unintended) state. It needs to be virtually non-occurring. Therefore, it is necessary to enclose the inert gas in the processing container, or to make fine particles by making a high vacuum, and to perform the intake and exhaust control by providing an inert gas intake and exhaust system with an airtight structure inside the processing container, It is necessary to evacuate the inside of the processing container until a high vacuum is reached to make fine particles.

  Further, since the 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 larger and the amount of medium balls and powder stored in the processing container becomes large, so the amount of heat generated with the atomization increases. The pressure inside the processing container increases. For this reason, since the through-hole portion of the fixed shaft with respect to the processing container that rotates at a high speed is a shaft seal against rotation with the processing container that rotates at high speed, it becomes difficult to ensure the airtightness of the processing container. There was a problem.

JP 2004-823 JP 2004-130305 A JP2008-212025

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

  In order to solve the above-described problem, a first aspect of the present invention includes a processing container that is rotatable around a central axis, a fixed shaft that is inserted into the processing container along the central axis, and the fixed shaft. And a guide vane attached to the inside of the processing container, and a medium ball and a powder are accommodated in the processing container, and the powder is atomized by rotating the processing container An apparatus, further comprising: a gas introduction channel for introducing an inert gas into the processing container; and an exhaust channel for discharging the gas inside the processing container; During the process of making fine particles, the inert gas is introduced into the processing container through the gas introduction flow path, and the inside of the processing container is discharged to discharge the inside of the processing container. Normal pressure inert gas atmosphere and Is configured so that, characterized in that.

  According to a second aspect of the present invention, in the first aspect, the gas introduction channel and the exhaust channel are formed on the fixed shaft.

  According to a third aspect of the present invention, in the first or second aspect, an oxygen concentration meter is provided in an exhaust system including the exhaust passage.

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

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, an exhaust system and / or chimney is provided in an exhaust system including the exhaust passage.

  According to the present invention, in the production of a fine particle product, a powder that can secure an inert atmosphere inside the processing container and can produce a fine particle product that is substantially free from undesirable (unintended) alteration under high safety. A body reaction device can be provided.

The figure which shows the structure of the powder reaction apparatus by one Embodiment of this invention. Sectional drawing which shows the introduction flow path and discharge flow path of the inert gas, and the seal structure in the powder reaction apparatus shown in FIG. The figure for demonstrating the principle of a convergence mill.

  Hereinafter, a powder reaction apparatus 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 an inert gas into the reactor 15 having a processing container 1 for storing powder and making it into fine particles, and inside the processing container 1. And an exhaust system 14 for exhausting the gas inside the processing vessel 1.

<Reactor 15>
The reactor 15 includes a cylindrical processing container 1 whose opposite ends on the central axis are sealed, and one end of the opposite ends on the central axis of the processing container 1 that passes through one end of the processing container 1. A fixed shaft 2 disposed along the axis, and a guide vane 3 attached to the fixed shaft 2 via a support portion 4 with a clearance 16 between the inner wall of the processing container 1 and a clearance 16 are provided.

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

  In a portion (penetrating portion) through which the fixed shaft 2 of the processing container 1 passes, 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 airtight. A sealing portion 19 is provided for maintaining the above.

  The powder reaction apparatus according to the present embodiment can perform MA treatment using, for example, a plurality of materials. When manufacturing such a product such as an alloy using such a reaction, the powder reaction apparatus is highly safe. In order to recover the fine particle product which ensures the property and is substantially free from undesirable (unintended) alteration, it is preferable to carry out fine particle formation of the powder in an inert gas atmosphere.

  Therefore, the powder reactor according to the present embodiment is configured to be able to atomize powder in an inert gas atmosphere, and the structure and operation method will be described below.

  Prior to the start of the operation of the reactor 15, first, the inspection door 20 provided in the processing container 1 is opened, the medium ball 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 inert gas atmosphere. The structure of the penetrating portion of the fixed shaft 2 of the processing container 1 will be described later.

  Thereafter, when the processing container 1 is rotated, as shown in FIG. 3, the powder 21 that has passed through the clearance 16 adheres to the inner wall of the processing container 1 by centrifugal force to form a powder layer 22. Part of the powder 21 is changed in the direction of movement 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 unit 24 to pulverize the powder.

  The clearance 16 is set based on the medium ball diameter to be used. In addition, fine powders (fine particles) having different particle diameters can be obtained by changing the rotation speed of the processing container 1 and the processing time. In addition, since the powder is atomized and stirred and mixed in an inert gas atmosphere, an alloy or the like that is substantially free from unwanted (unintended) alteration can be produced under high safety by MA treatment.

<Structure of penetrating portion of fixed shaft 2 of processing container 1>
FIG. 2 is a partially enlarged view of the through portion of the fixed shaft 2 in the processing container 1, and shows the gas introduction flow path 25 and the 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.

  At the center of the fixed shaft 2, an exhaust passage that linearly penetrates from the inner end of the processing container 1 to the outer end of the processing container 1 and discharges the inert gas from the processing container 1 to the outside. 26 is arranged. On the other hand, on the outer peripheral side of the exhaust passage 26, gas introduction passages 25 for introducing an inert gas into the processing container 1 are arranged at several locations at appropriate intervals in the circumferential direction.

  Since both the gas introduction flow path 25 to the inert gas 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 exhausted. The connection part such as the piping of the flow path 26 does not need a rotary joint or the like, and the connection part has a simple structure.

  Note that, regarding the arrangement of the gas introduction flow path 25 and the exhaust flow path 26, contrary to the above, from the outer end of the processing container 1 to the inner end of the processing container 1 from the center of the fixed shaft 2. A gas introduction passage 25 is provided that penetrates in a straight line and introduces an inert gas from the outside to the inside of the processing vessel 1. The gas introduction passage 25 is provided at several locations on the outer circumference side of the gas introduction passage 25 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.

  The through-hole of the processing vessel 1 of the fixed shaft 2 is provided with a seal portion 19 on the inner side of the processing vessel 1 and a (rotating) bearing 6 on the outer side, and the seal portion provided on the inner side. The airtightness of the processing container 1 is maintained by 19.

  The inert gas is introduced into the processing vessel 1 from the inert gas supply system 13 at normal pressure or a positive pressure close thereto and / or at a predetermined flow rate, and the processing vessel 1 is always open to the atmosphere. It is connected to the. With such a configuration, the processing container 1 has a very large volume compared to the cross-sectional area of the gas introduction flow path 25 and is always open to the atmosphere, so that the inert gas is processed at a slightly higher positive pressure. Even if introduced into the container 1, the pressure of the inert gas immediately after being introduced into the processing container 1 becomes a normal pressure.

  Thus, since the pressure of the inert gas inside the processing vessel 1 is normal pressure, the differential pressure on both sides of the seal portion 19 is small, and the sealing performance against high pressure as used in a high-pressure processing vessel or the like is low. There is no need, and a sealing mechanism similar to that used in a normal atmospheric pressure processing container, for example, a sealing mechanism using a sealing material such as an oil seal is sufficient.

  In addition, predetermined values, such as the flow volume of the inert gas introduce | transduced into the interior space of the processing container 1, are set based on the result acquired by the preliminary test etc. in advance.

  Further, in order to prevent the inflow of outside air from the seal part 19 into the processing container 1 due to deterioration of the airtightness of the seal 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 depends on the flow resistance and suction force in the exhaust system 14, but by setting the pressure in the processing container 1 to the positive pressure side, the power consumption of the exhaust fan 10 can be reduced. There is a possibility that it can contribute to.

  In addition, when the temperature inside the processing container 1 is increased due to heat generated by the microparticulation and the pressure of the inert gas is about to increase, the exhaust system 14 is opened to the atmosphere. Due to the increase in the differential pressure with the environment, the gas discharge flow rate through the exhaust system 14 increases in conjunction with the increase in the gas pressure in the processing container 1. That is, in the configuration of the present embodiment, the gas pressure in the processing container 1 can be increased with a simple configuration without providing a complicated or advanced feedback control system that controls the pressure in the processing container 1 to be constant. It has the feature that it can be suppressed.

  Thus, with the configuration of the present embodiment, the gas pressure in the processing container 1 can be suppressed to the normal pressure range even when the temperature in the processing container 1 is about to rise due to heat generated by the atomization. The fact that the seal part 19 suffices with a normal hermetic 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 decompression flow meter 12, and continuously introduces an inert gas into the processing vessel 1 during operation of the apparatus. The inert gas supply source 7 is, for example, a gas cylinder of argon gas or nitrogen gas. The decompression flow meter 12 is provided in a pipe immediately before the connection portion of the processing container 1 and adjusts the gas pressure of the inert gas introduced into the processing container to a set pressure.

<Exhaust system>
In the exhaust system 14, the dust collector 9 and the exhaust fan 10 are arranged in this order, and the exhaust port of the exhaust fan 10 is always opened to the atmosphere so that the gas pressure in the processing container 1 during operation is maintained at normal pressure. It is.

  The dust collector 9 collects the powder or fine particles flowing out along with the inert gas discharged from the processing container 1 by a dust collector 9 disposed upstream of the exhaust fan 10. For example, the dust collector 9 having a bag filter is provided with the dust collector 9. Can be used.

  The exhaust fan 10 has a large flow resistance in the exhaust system 14 in the piping and the dust collector 9, and in particular, it is processed only by the pressure difference between the processing container 1 and the external environment due to the pressure increase in the processing container 1 due to heat generation during atomization processing. When the discharge flow rate that can maintain the gas pressure in the container 1 at normal pressure cannot be ensured, the discharge flow rate is forcibly ensured. Therefore, when the flow resistance in the piping 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 do or stop driving.

  Note that the flow rate of the exhaust gas is basically maintained at a normal pressure if the gas having a flow rate corresponding to the gas flow rate introduced into the process vessel 1 is discharged from the inert gas supply system 13. Therefore, by reducing the flow rate of gas introduced into the processing container 1, the discharge flow rate can also be reduced, and even when the exhaust fan 10 is operated, energy consumption can be reduced.

  Further, by increasing the length (height) of the exhaust port 27 of the exhaust fan 10 or by arranging a chimney at the exhaust port 27 to increase the suction force, the power consumption of the exhaust fan 10 is reduced. Can be made. Further, a chimney having an appropriate height may be disposed instead of the exhaust fan 10 according to the suction force required for the exhaust system 14. In particular, when the gas temperature in the processing container 1 rises due to heat generation due to the formation of fine particles, the suction force due to the chimney effect increases. Therefore, when the heat generation in the processing container 1 is large, the effect of the chimney arrangement is effective. The chimney is preferable because it is inexpensive and does not require maintenance costs such as power consumption.

  Further, after the atomization is completed, the flow rate of the introduced gas into the processing vessel 1 by the inert gas supply system 13 is increased, and the exhaust gas flow rate by the exhaust fan 10 is increased, so that the fine particles produced in the processing vessel 1 are increased. It can be forcibly recovered by the dust collector 9 by the exhaust gas.

  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, the inert gas in the processing container 1 is used when outside air flows into the processing container 1 due to leakage of the seal portion 19 or the like, or when a back flow occurs in the exhaust system 14. The abnormal atmosphere can be monitored.

  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. Note that the predetermined oxygen concentration for determining the occurrence of abnormality may be based on, for example, the explosion limit oxygen concentration of a treated raw material that does not cause a dust explosion.

DESCRIPTION OF SYMBOLS 1 Processing container 2 Fixed shaft 3 Guide vane 4 Support part 5 Rotating shaft 6 Bearing 7 Inert gas supply source 8 Oxygen concentration meter 9 Dust collector 10 Air exhauster 11 Filter 12 Decompression flow meter 13 Inert gas supply system 14 Exhaust system 15 Reactor 16 Clearance 17 Fixed shaft support portion 18a, b Bolt 19 Seal portion 20 Inspection door 21 Powder 22 Powder layer 23 Media ball 24 Collision portion 25 Gas introduction passage 26 Exhaust passage 27 Exhaust port

Claims (5)

A processing vessel rotatable around a central axis, a fixed shaft inserted into the processing vessel along the central axis, and a guide vane attached to the fixed shaft; and inside the processing vessel A powder reactor configured to store a medium ball and powder and to atomize the powder by rotating the processing container,
A gas introduction channel for introducing an inert gas into the processing vessel;
An exhaust passage for exhausting the gas inside the processing vessel, and
In the process of making the powder into fine particles, the inert gas is introduced into the processing container through the gas introduction flow path, and the gas in the processing container is discharged, whereby the processing is performed. A powder reactor configured so that the inside of a container is an atmosphere of an inert gas under normal pressure.   The powder reaction apparatus according to claim 1, wherein the gas introduction channel and the exhaust channel are formed on the fixed shaft.   The powder reaction apparatus according to claim 1 or 2, wherein an oxygen concentration meter is provided in an exhaust system including the exhaust passage.   The powder reaction apparatus 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 reaction apparatus according to any one of claims 1 to 4, wherein an exhaust system and / or chimney is provided in an exhaust system including the exhaust passage.

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