JP6194455B1 - Powder surface modification equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder surface reforming apparatus capable of uniformly treating the surface of a powder, having a high recovery rate of a treated product, and capable of an efficient treatment. A cylindrical container 4 is supported so as to be rotatable or swingable, and is parallel to the rotation or swing center axis x of the container 4 at a position in the container 4 that is spaced from the inner wall of the container. A plurality of rod-like discharge electrodes 5 are arranged, and the discharge electrode 5 constitutes one or a plurality of electrode sets 10 that are kept at a distance capable of discharging between adjacent discharge electrodes 5 and 5, and the electrode set 10 When the powder is stirred by rotating or swinging the container 4, the stirred powder is in the plasma P formed between the discharge electrodes 5 and 5 constituting the electrode set 10. The surface of the powder is modified by the energy of the plasma. [Selection] Figure 1

Description

  The present invention relates to a powder surface modifying apparatus for modifying a powder surface by plasma.

A device disclosed in Patent Document 1 has been known as an apparatus for performing surface modification of powder using plasma.
As shown in FIG. 7, this conventional surface modification apparatus is opposed to the peripheral electrode 2 constituting the inner wall of the cylindrical container 1 with a predetermined gap between the peripheral electrode 2 in the container 1. A central electrode 3.
Then, when an AC high voltage is applied between the electrodes 2 and 3 while putting the powder into the container 1 and rotating the container 1, plasma is generated between the electrodes 2 and 3, and the plasma generates a powder. It is an apparatus in which the surface of the material is modified.

JP 2012-196669 A JP 2010-029831 A

  In the conventional surface modification apparatus, a strong electric field E is formed between the peripheral electrode 2 and the center electrode 3 as shown in FIG. Therefore, the powder charged between the electrodes 2 and 3 is always affected by the electric field E during the process, and the powder in the container 1 is easily charged and easily electrostatically aggregates. The powder that has become an agglomerate is not easily loosened even when the container 1 rotates, and is exposed to plasma as an agglomerate. Therefore, only the surface of the aggregate is modified, and the powder inside the aggregate is not modified. As a result, there is a problem that the modification of the powder as a whole is uneven and the powder having the desired surface characteristics cannot be obtained.

In addition, since the powder is always located in the strong electric field E as described above, it tends to have heat. If the powder aggregate generates heat, the surface melts and is integrated (blocked). Once blocked, it is no longer in powder form and will not be unraveled.
Further, in the conventional surface modification apparatus, since the container 1 constitutes the peripheral electrode 2, current flows through the inner wall of the container 1 and Joule heat is generated. Therefore, the powder in contact with the inner wall of the container 1 may be heated and melted and fixed to the inner wall.
In particular, since powder tends to collect in the lower portion of the container 1 due to gravity, sticking and blocking are likely to occur at this portion.

Once the material is blocked or fixed to the inner wall of the container 1, even if it is exposed to plasma, it does not become a modified target powder.
In addition, there is a problem that the powder that has been heated as it melts becomes denatured.
As described above, the conventional apparatus cannot uniformly modify the surface of the powder. In addition, there is a problem that the recovery rate of the target powder is poor due to the formation of aggregates and fixed matter and thermal alteration.
Furthermore, since it is necessary to remove fixed matter and aggregates from the container 1, there is a problem that it takes time to clean the container 1.
An object of the present invention is to provide a powder surface reforming apparatus that can uniformly treat the surface of a powder, has a high recovery rate of a processed product, and enables an efficient treatment.

The present invention provides a powder surface modification apparatus in which powder to be processed is placed in a cylindrical container, and the surface of the powder is modified by the energy of plasma formed in the container. Assumption.
The first invention, the container is supported rotatably or oscillating, in a position to keep a distance from the inner wall of the container a the container, parallel to the rotation or swing center axis of the container, and the circumference along the discharge electrodes of the plurality of bar is placed, the discharge electrodes, Rutotomoni rod-shaped metal electrode is formed is covered with a dielectric, between the discharge electrodes adjacent in the circumferential direction can be discharged One or a plurality of electrode sets maintained at a distance and a potential difference are configured, and each of the electrode sets is configured such that when the powder is stirred by rotating or swinging the container, the stirred powder is It is provided at a position that passes through the plasma formed between the discharge electrodes constituting the set.

  In addition, the said electrode group is a group which consists of a pair of discharge electrode by which the distance between adjacent discharge electrodes was maintained at the distance which can be discharged. And when one specific discharge electrode keeps the distance between the discharge electrodes on both sides to a distance that allows discharge, the specific discharge electrode constitutes an electrode set with each of the discharge electrodes on both sides. become.

  The second invention is characterized in that a stirring convex portion protruding toward the center is provided on the inner wall of the container.

  According to a third aspect of the present invention, a gas supply tube along the central axis is provided in the container between the discharge electrode and the central axis of rotation or swinging of the container. A plurality of injection ports are formed, and a plasma generation gas supply means is connected to one end in the longitudinal direction, and the plasma generation gas is injected from the injection ports.

  In a fourth aspect of the invention, the injection port is provided at a position corresponding to at least between adjacent discharge electrodes of the electrode set, and the plasma generating gas is injected from the injection port toward the adjacent discharge electrodes. It is characterized by being.

According to the first invention, since the powder to be processed is affected by a strong electric field only when it passes between the electrodes on which the plasma is formed, it is always present in the electric field as in the prior art. It is hard to be charged as compared with the powder, and the powder is difficult to electrostatically aggregate. Therefore, the powder falls in a state of being separated by the rotation of the container and is exposed to plasma in the process, so that the powder surface is uniformly modified.
Further, since the time for which the powder is subjected to the action of the electric field is short, the powder does not generate heat due to the electric field. Therefore, the surface is not melted and blocked by heat generation.
Furthermore, since no electrode is formed on the inner wall of the container, no Joule heat is generated on the inner wall. Therefore, the powder surface is not melted by the heat generation of the inner wall, the powder is not aggregated, the powder is not fixed to the container, and the powder is not thermally altered.
In particular, since the discharge electrode is formed by covering a metal electrode with a dielectric, uniform discharge can be generated over the entire length in the length direction of the discharge electrode.
Therefore, the powder can be uniformly modified with a good yield. Further, the burden of the container cleaning work is reduced, and the workability of the reforming process is improved.

According to the second invention, the rotating or swinging stirring convex portion can transport the powder in the container to a higher position. Since the powder is more likely to fall apart when dropped from a high position, the powder exposed to the plasma between the discharge electrodes during the dropping process is uniformly surface-modified.

  According to the third aspect of the invention, the stirring force by the spray force of the plasma generating gas is added to the stirring action by the gravity drop, so that the powder becomes more dispersed and dances in the container. Therefore, the powder is not aggregated and the surface can be more uniformly modified.

According to the fourth aspect of the invention, the plasma generating gas is injected in the direction intersecting the electric field formed between the adjacent electrodes, and the plasma generated by the discharge can be spread in the gas injection direction. Since the area where the plasma is generated can be increased in this way, the stirred powder is easily exposed to the plasma, and the processing time can be shortened.

It is sectional drawing of the container of 1st Embodiment of this invention. It is the schematic which showed the whole structure of 1st Embodiment. It is sectional drawing of 2nd Embodiment, Comprising: (a) is the state which has stopped the container, (b) has shown the state which the container is rotating. It is sectional drawing of the container of 3rd Embodiment. It is the elements on larger scale of FIG. It is sectional drawing of the container of 4th Embodiment. It is the schematic of the surface treatment apparatus of the conventional powder.

The powder surface reforming apparatus according to the first embodiment of the present invention has a glass cylindrical container body 4 as a container of the present invention as shown in FIG. A plurality of rod-shaped discharge electrodes 5 are arranged.
As shown in FIG. 2, the container body 4 includes a flange portion 4b formed integrally with the cylinder portion 4a in a cylinder portion 4a having both ends open, and the openings at both ends are closed by bottom plate members 6 and 7. It is peeling off.
Each discharge electrode 5 is composed of a dielectric pipe 8 made of ceramic or the like and a rod-like metal electrode 9 inserted therein, and is parallel to the rotation center axis x of the container body 4 to be described later. It is arranged at equal intervals along the circumference.

The high voltage side and the ground side of the high voltage power source 11 are alternately connected to the metal electrode 9 of the discharge electrode 5 arranged along the circumference (see FIG. 1). The high voltage power supply 11 is a power supply that outputs a high frequency high voltage of, for example, 1 [kHz] or higher. The output frequency of the high voltage power supply 11 is not particularly limited, but is preferably about 1 [kHz] to 110 [kHz] in consideration of stable discharge, heat generation, and the like.
Furthermore, in the first embodiment, all the discharge electrodes 5 arranged along the circumference keep the distance between themselves and the adjacent discharge electrodes 5 at a dischargeable distance, and together with the adjacent discharge electrodes 5, the present invention. The electrode set 10 is configured. That is, in the first embodiment, one discharge electrode 5 forms one electrode set 10 together with each of the adjacent discharge electrodes.

Therefore, when a high voltage is applied to the discharge electrode 5 with the high voltage power supply 11 turned on, the discharge is generated by the electric field E indicated by the broken arrow between the adjacent discharge electrodes 5 and 5 constituting the electrode set 10. The plasma area P shown in FIG. 1 is formed in a ring shape.
The reason why the metal electrode 9 is covered with the dielectric pipe 8 is to generate a uniform discharge over the entire length of the discharge electrode 5 by covering the metal electrode 9 with the dielectric. When a high voltage is applied with the metal electrode 9 exposed, a discharge may occur only from a specific point of the metal electrode 9.

As the material constituting the dielectric pipe 8, various dielectric materials having heat resistance and voltage resistance characteristics such as heat-resistant tempered glass, quartz glass, and resin can be used in addition to ceramic.
Moreover, the metal electrode 9 inserted in the said dielectric pipe 8 should just be rod-shaped, and cross-sectional shape and length are not specifically limited. The shape and length of the discharge electrode 5 may be selected so as to enable more uniform discharge over the entire length in the length direction.

  When powder to be processed is put into the container body 4 as described above and the container body 4 is rotated in the direction of arrow A in FIG. 1 while applying a voltage, the powder adheres to the inner wall of the container body 4. , Move with the inner wall surface. Then, when gravity overcomes the adhesion force of the powder to the inner wall surface, the powder falls downward. In this dropping process, the powder passes through the plasma area P between the discharge electrodes 5 and 5. The powder thus stirred by the rotation of the container body 4 passes through the plasma area P, and the surface is modified by the energy of the plasma.

Next, means for rotating the container body 4 and specific means for supplying a high voltage to the discharge electrode 5 will be described with reference to FIG.
FIG. 2 is a schematic view of the entire apparatus of the first embodiment as viewed from the side surface along the rotation center axis x of the container body 4. In FIG. 2, only the discharge electrodes 5 arranged along the circumference as shown in FIG. 1 are shown at the upper and lower ends of the container body 4, and the other discharge electrodes 5 are omitted.

As shown in FIG. 2, bottom plate members 6 and 7 are fixed to the flange portion 4 b of the container body 4. Support holes 6 a and 7 a for supporting the dielectric pipe 8 constituting the discharge electrode 5 are formed in the bottom plate members 6 and 7. The dielectric pipe 8 is passed between the bottom plate members 6 and 7 in parallel with the rotation center axis x of the container body 4, and both end sides thereof are inserted and fixed in the support holes 6a and 7a.
A conducting wire 12 connected to the metal electrode 9 in the dielectric pipe 8 is drawn out from one end of the dielectric pipe 8 to the outside.
Further, gas passages 6b and 7b penetrating in the thickness direction are formed in the center of the bottom plate members 6 and 7.
The bottom plate members 6 and 7 are members in which metal gear portions 6c and 7c are provided on the outer periphery of a resin disk, for example.

In addition, a metal rotation shaft 13 is fixed to one bottom plate member 6. The rotating shaft 13 includes a shaft portion 13a and a mounting portion 13b. The shaft portion 13a is rotatably supported by a metal bearing member 14 such as a bearing, and the mounting portion 13b is supported by a bolt or the like. It is fixed to. The center line of the rotation shaft 13 becomes the rotation center axis line x of the container body 4.
The bearing member 14 is connected to the high voltage side of the high voltage power supply 11. Since the bearing member 14 made of metal and the rotating shaft 13 are kept in an electrically conductive state, a high voltage is applied to the rotating shaft 13 by the high voltage power supply 11. Therefore, a high voltage can be applied to the discharge electrode 5 by connecting the conducting wire 12 drawn out from the dielectric pipe 8 to the attachment portion 13 b of the rotating shaft 13.

The bottom plate members 6 and 7 are supported from below by gears 15 and 16 meshing with the metal gear portions 6c and 7c constituting the outer periphery thereof. The gears 15 and 16 are connected by a single metal rotating shaft 17, and both ends of the rotating shaft 17 are rotatably supported by metal bearing members 18 and 19. One gear 15 meshes with a gear 20 that meshes with it, and an output shaft of a motor M is connected to the gear 20.
Therefore, when the motor M rotates, a rotational force is transmitted from the gear 20 to the gear 15, the rotating shaft 17, and the gear 16, and the gear portions 6c and 7c engaged with the gears 15 and 16 rotate. As a result, the container body 4 rotates with the discharge electrode 5.

  In the first embodiment, the ground side of the high voltage power supply 11 is connected to the bearing member 18. The bearing members 18 and 19, the gears 15 and 16, the rotating shaft 17, and the gear portions 6c and 7c formed of metal are kept in an electrically conductive state, so that all of them are kept at the ground potential. Therefore, the discharge electrode 5 can be kept at the ground potential by connecting the lead wire 12 drawn from the dielectric pipe 8 to the gear portion 6c.

  And in this 1st Embodiment, as shown in FIG. 1, among the discharge electrodes 5 provided circumferentially, those to which a high voltage is applied and those to be maintained at the ground potential are alternately arranged. I am doing so. Therefore, depending on the position of the discharge electrode 5, the conducting wire 12 connected to the metal electrode 9 is connected to the mounting portion 13 b or connected to the gear portion 6 c. FIG. 2 shows a state in which the conductive wire 12 of the discharge electrode 5 on the high voltage side is connected to the mounting portion 13b of the rotating shaft 13, but the conductive wire 12 (not shown) of the discharge electrode 5 on the ground side is connected to the gear portion 6c. It is connected.

Further, the rotary shaft 13 is formed with a gas passage 13c along the central axis. The gas passage 13c communicates with the gas passage 6b of the bottom plate member 6 when the attachment portion 13b is fixed to the bottom plate member 6. The gas passage 13c and 6b allows the gas for generating plasma to be supplied from the outside to the container body 4. I try to guide it inside.
On the other hand, the gas passage 7b formed in the bottom plate member 7 is a passage for discharging the gas in the container body 4 when the plasma generating gas is continuously supplied. The supply amount of the plasma generating gas is adjusted in accordance with the amount of gas exhausted from the gas passage 7b so that the pressure in the container body 4 is maintained at or near atmospheric pressure.

Further, an exhaust gas treatment container (not shown) can be connected to the gas passage 7b. The exhaust gas treatment container is provided with a filter formed of a sintered metal or the like that collects the powder discharged together with the gas, a decomposition device for decomposing toxic gas, and the like. This decomposition apparatus decomposes, for example, ozone and nitrogen oxide generated during plasma generation.
However, if the container main body 4 has good sealing properties and the concentration of the plasma generating gas inside can be kept constant, the plasma generating gas need not be continuously supplied. In that case, the exhaust gas passage 7b Is not necessary. Further, the exhaust gas treatment container is not essential.

In the surface reforming apparatus as described above, the high voltage power supply 11 is turned on by rotating the container body 4 filled with powder while supplying the plasma generating gas into the container body 4 from the gas passage 13c of the rotating shaft 13. Then, the powder stirred by the rotation of the container body 4 passes through the plasma area P shown in FIG.
In the first embodiment, unlike the conventional apparatus shown in FIG. 7, since the powder is not always subjected to the action of a strong electric field, electrostatic aggregation of the powder occurs or the powder generates heat. Does not melt.

Further, since the inner wall surface of the container body 4 does not generate heat due to Joule heat, it does not stick to the inner wall surface.
Furthermore, the powder is not altered by heat.
Therefore, compared with the conventional surface modification apparatus, uniform surface modification is possible and the recovery rate of the surface-modified powder is good.

The means for rotating the container body 4 and the means for applying a voltage to the discharge electrode 5 are not limited to those shown in FIG. 2, and various general means can be used. Moreover, you may make it rock | fluctuate instead of rotating the container main body 4. FIG. The powder inside may be agitated by rotating or swinging the container body 4.
In the first embodiment, the discharge electrode 5 fixed to the bottom plate members 6 and 7 and the container main body 4 rotate integrally. However, only the container main body 4 is not rotated without rotating the discharge electrode 5. The container body 4 and the discharge electrode 5 may be rotated separately. In that case, it is necessary to connect the bottom plate members 6 and 7 holding the discharge electrode 5 and the container body 4 so as to be relatively rotatable.

  Furthermore, in the first embodiment, one of the adjacent discharge electrodes 5 and 5 is connected to the high voltage side of the high voltage power supply 11 and the other is connected to the ground side, but one of them must be kept at the ground potential. There is no. The potentials of the adjacent discharge electrodes 5 and 5 only need to generate a potential difference capable of generating plasma between them. Therefore, any method of applying a voltage to each discharge electrode 5 may be used.

In the second embodiment shown in FIG. 3, the stirring convex portion 21 is provided on the inner wall of the container body 4, and other configurations are the same as those in the first embodiment. Therefore, the same reference numerals as those in FIG. 1 are used for the same components as those in the first embodiment, and FIGS. 1 and 2 are also referred to in the description of the second embodiment.
In FIG. 3, the metal electrode 9 is omitted, but the discharge electrode 5 includes a dielectric pipe 8 and a metal electrode 9. Although part of the reference numeral 10 is omitted, all the discharge electrodes 5 together with the adjacent discharge electrodes 5 constitute the electrode set 10 of the present invention.
The stirring convex portion 21 is a rod-shaped convex portion having a length in the axial direction of the container body 4 and is provided over almost the entire length of the container body 4. The stirring convex portion 21 may be formed integrally with the container body 4 or may be configured by adhering a rod-shaped separate member to the inner wall.

In the second embodiment, discharge electrodes 5 similar to those in the first embodiment are provided in the container body 4 along the circumference, and these are alternately connected to the high voltage side and the ground side of the high voltage power source 11. (Refer FIG. 1), the electrode set 10 is comprised along the perimeter. Therefore, when a high voltage is applied to the discharge electrode 5, the plasma area P shown in FIG. 3 is formed in a ring shape.
If the container body 4 is rotated in this state, the powder stirred by this rotation passes through the plasma area P and is surface-modified. And compared with the conventional apparatus shown in FIG. 7, the point which can implement | achieve a uniform surface modification process efficiently is the same as that of 1st Embodiment.

Further, in the second embodiment, as shown in FIG. 3B, the stirring convex portion 21 in which the powder accumulated downward due to gravity moves as the container body 4 rotates as shown in FIG. So that it is carried above the container body 4. The position where the powder is carried by the stirring convex portion 21 is higher than the position where the powder is separated from the inner wall of the container body 4 when the stirring convex portion 21 is not provided. Therefore, the powder falls from a higher position, breaks up, and passes through the plasma area P. By separating the powder, all powder surfaces are more uniformly modified.
Note that a plurality of the machine stirring convex portions 21 may be provided in order to better stir the powder.
Moreover, the stirring convex part 21 should just be what can agitate powder, and the shape may not be rod-shaped.

The third embodiment shown in FIG. 4 is an apparatus in which a gas supply tube 22 along the rotation center axis x is provided between the rotation center axis x of the container body 4 and the discharge electrode 5.
The gas supply cylinder 22 is a cylindrical member having an axial length substantially equal to that of the container body 4 and having one bottom surface closed, and a plurality of injection ports 22a are formed on the side surface.
The opening on the other bottom side of the gas supply cylinder 22 is closed by the bottom plate member 6 (see FIG. 2), and communicates with the outside by a gas passage 6b formed in the bottom plate member 6.
Other configurations are the same as those in the first embodiment. Therefore, FIGS. 1 and 2 are also referred to in the description of the third embodiment. In FIG. 4, reference numeral 10 is omitted. Even in the apparatus according to the third embodiment, the distance between the adjacent discharge electrodes 5 and 5 maintains a dischargeable distance. An electrode set 10 is configured.

Further, as shown in FIG. 4, a plurality of the injection ports 22a are formed on the side surface of the gas supply tube 22 along the circumference and also in the axial direction. The injection port 22a is provided at a position corresponding to between the discharge electrodes 5 and 5 arranged along the circumference so that the plasma generating gas is injected between the discharge electrodes 5 and 5.
Therefore, when plasma generating gas is supplied to the gas supply cylinder 22 from the gas passage 13c and the gas passage 6b formed in the rotating shaft 13, the plasma generating gas is supplied from the injection port 22a to the discharge electrodes 5,5. Injected between the five. The plasma generating gas injected from the injection port 22a is turned into plasma by the electric field formed between the discharge electrodes 5 and 5, and a plasma area P is formed.

If the container body 4 is rotated in the same manner as in the first embodiment in a state where the plasma area P is formed, the powder is stirred by this rotation, and the stirred powder falls into the plasma in the process of dropping. The surface is modified by passing through the area P.
In particular, in this third embodiment, the plasma generating gas injected from the injection port 22a causes the powder in the container to be scattered apart by the injection pressure. pass. That is, the powder is better agitated by the rotation of the container body 4 and the gas injection pressure, and more uniform surface modification can be achieved.

Moreover, in the third embodiment, the injection port 22a is provided between the adjacent discharge electrodes 5 and 5, so that it is generated between the discharge electrodes 5 and 5, as shown in FIG. The plasma is spread toward the inner wall of the container body 4 by the gas injection pressure. Since the plasma area P is thus widened, there is an advantage that the powder is easily exposed to plasma and the processing time can be shortened.
The plasma generating gas supplied into the container body 4 is discharged from the gas passage 7b of the bottom plate member 7 and processed in an exhaust gas processing container (not shown).

The fourth embodiment shown in FIG. 6 is an apparatus in which the discharge electrodes 5 are arranged not along the circumference but along only part of the circumference. Further, in the fourth embodiment, the container body 4 is not rotated, but is swung as indicated by arrows A and B to stir the powder, and the discharge electrode 5 is not swung, and the illustrated position is maintained. It is configured to keep.
In the fourth embodiment, the powder stirred by the swinging of the container body 4 hardly reaches the uppermost part of the container body 4. Thus, the discharge electrode 5 is omitted in the upper portion where no powder is present, and the discharge electrode 5 is arranged only in a portion where the abundance of the agitated powder is high so that a dischargeable electrode set 10 is configured. I have to. In other words, it is possible to save energy by omitting the discharge electrode 5 at a position where there is almost no powder and generating a plasma area P that does not contribute to surface modification.

Similarly to the above-described other embodiments, this fourth embodiment is also free from electrostatic agglomeration of powder, blocking, adhesion to the inner wall of the container, and thermal alteration, as compared with the conventional surface modification device of FIG. Uniform surface modification is possible.
In the fourth embodiment, the discharge electrode 5 is stationary and only the container body 4 is swung. However, the discharge electrode 5 may be swung integrally with the container body 4.

In the said 1st-3rd embodiment, the several discharge electrode 5 is arrange | positioned at equal intervals along the periphery, and the electrode group 10 which enabled discharge of the distance with the discharge electrode 5 which all the discharge electrodes 5 adjoin is comprised. And in 4th Embodiment, although the discharge electrode 5 is arrange | positioned along a part of periphery and the electrode group 10 is comprised, arrangement | positioning of the discharge electrode 5 is not limited to the said embodiment.
For example, the discharge electrodes 5 may be arranged along a square or a triangle, or the electrode sets 10 including the discharge electrodes 5 and 5 that maintain a dischargeable distance are arranged so as to maintain a distance that does not discharge. May be.

In the said 1st-4th embodiment, although the cylindrical container main body 4 is used, the shape of the container main body 4 is not restricted to a cylinder. As long as the powder can be stirred by rotation or swing, the container body 4 may be any shape such as a cylinder having a polygonal or semicircular cross-sectional shape.
Moreover, the discharge electrode 5 should just be provided in the position which can pass the stirred powder between the adjacent discharge electrodes 5 and 5 provided in the distance which can be discharged like the said embodiment. It is not limited to the arrangement along the inner wall of the container body 4.
Furthermore, the material of the member that comes into contact with the powder, such as the container body 4, the bottom plate members 6 and 7, and the gas supply cylinder 22, is not particularly limited as long as it is insulating.

In the devices of the first to fourth embodiments, the possibility of plasma generation in the electrode set 10 and the distance between the discharge electrode 5 and the inner wall of the container body 4 are not directly related. Therefore, the dischargeable electrode set 10 can be provided close to the center of the container body 4, and the distance between the discharge electrode 5 and the inner wall of the container body 4 can be increased. Thus, if the distance between the inner wall of the container body 4 and the discharge electrode 5 can be increased, the amount of powder that can be accommodated in the container body 4 without being in contact with the discharge electrode 5 can be increased. As a result, many powders can be modified at one time.
On the other hand, in the conventional apparatus shown in FIG. 7, the distance between the peripheral electrode 2 and the center electrode 3 is limited to the distance that can be discharged. Therefore, it is difficult to increase the capacity of the container 1, and there is a problem that the amount of powder that can be processed at one time cannot be increased.

  Furthermore, in the said 1st-4th embodiment, although the pressure in the container main body 4 is maintained at atmospheric pressure or its vicinity, it is not necessary to limit an internal pressure to atmospheric pressure or its vicinity. For example, the discharge can be facilitated by using a negative pressure. However, as the difference between the pressure in the container body 4 and the atmospheric pressure increases, a strict sealing mechanism, a pressure-resistant container, a decompression means, and the like are required, and there is a problem that the processing apparatus becomes larger. Therefore, if the reforming process can be performed while maintaining the interior of the container body 4 at or near atmospheric pressure, effects such as simplification of the apparatus can be obtained.

  The surface modification apparatus of the present invention is useful for surface modification treatment of various powders such as drugs and resin powders used as raw materials for industrial products.

4 Container Body 5 Discharge Electrode 8 Dielectric Pipe 9 (Constructing Discharge Electrode) Metal Electrode 10 (Constructing Discharge Electrode) Electrode Set 11 High Voltage Power Supply 13 Rotating Shaft 22 Gas Supply Tube 22a Injection Port P (Formed Plasma) ) Plasma area E Electric field x Rotation center axis

Claims (4)

A powder surface modification device in which a powder to be treated is placed in a cylindrical container, and the surface of the powder is modified by the energy of plasma formed in the container,
The container is supported to be rotatable or swingable ,
Within this a a keep a proper distance from the inner wall of the container and position the container, parallel to the rotation or swing center axis of the container, and along the circumference a plurality of rod-shaped discharge electrodes are placed,
The discharge electrodes are rod-shaped metal electrode with consists covered with a dielectric, an electrode assembly was maintained at dischargeable distance and potential difference between the discharge electrodes adjacent in the circumferential direction one or a plurality of configuration ,
When the powder is agitated by rotating or swinging the container, each of the electrode sets is in a plasma formed between the discharge electrodes constituting the electrode set. A powder surface modification device provided at a passing position.   The powder surface modification device according to claim 1, wherein the inner wall of the container is provided with a stirring convex portion protruding toward the center. In the vessel, a gas supply tube is provided along the central axis between the discharge electrode and the rotation or swing central axis of the vessel.
The gas supply cylinder has a plurality of injection ports formed on the outer wall thereof, and a plasma generation gas supply means is connected to one end in the longitudinal direction.
The powder surface modification apparatus according to claim 1 or 2, wherein the plasma generating gas is injected from the injection port.   The injection port is provided at a position corresponding to at least between adjacent discharge electrodes of the electrode set, and plasma generating gas is injected from the injection port toward the adjacent discharge electrodes. The powder surface modification apparatus as described.

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