JP6283021B2 - Powder classification device and powder classification system - Google Patents

Description

  The present invention is a powder that classifies a raw material powder into a plurality of types of powder by separating the raw material powder conveyed in a mixed state with a gas according to the size or density (or specific gravity) of the powder. The present invention relates to a classification device and a powder classification system.

  Conventionally, various types of powder classifiers that mix and transport raw material powder having a particle size distribution into gas and classify it into multiple types of powder according to the size or density of the powder It has been known. For example, in a powder classification apparatus that classifies raw material powder into fine powder and coarse powder, so-called fine powder including, for example, powder having a particle size distribution on the order of microns is handled as raw material powder.

  In such a conventional powder classifier, a powder classifier that employs a rectangular channel cross section as a raw material powder channel is known (see, for example, Non-Patent Document 1). In the powder classifying device of Non-Patent Document 1, the raw material powder channel having a rectangular channel cross section is branched into a fine powder channel and a coarse powder channel, and each flow is divided by inertia force at this branch portion. The size of the powder flowing into the road is classified.

  In addition, a powder classifying apparatus that employs an annular channel cross section instead of a rectangular channel cross section as a raw material powder channel has been proposed (for example, see Non-Patent Document 2). In the powder classifying apparatus of Non-Patent Document 2, a uniform raw material powder airflow is formed along the axial direction in the raw material powder passage having an annular passage cross section, and the fine powder flow is passed through this raw material powder passage. Branching into a channel and a coarse powder channel, the size of the powder flowing into each channel is classified using the inertial force at this branching portion.

  In such a powder classification device of Non-Patent Document 2, the flow channel end (short-side end) that existed in the configuration of the rectangular flow channel cross section as in the device of Non-Patent Document 1 may be eliminated. And the classification accuracy can be improved.

"Improvement of the Classification Performance of a Rectangular Jet Virtual Impactor", Kuniaki Gotoh and Hiroaki Masuda, Aerosol Science and Technology 32: 221-232 (2000), 2000 American Association for Aerosol Research "Development of annular-type virtual impactor", Kuniaki Gotoh and Hiroaki Masuda, Powder Technology 118 (2001) 68-78

  In the powder classifiers such as Non-Patent Documents 1 and 2, a raw material powder channel having a rectangular channel cross section or an annular channel cross section is employed, and in order to perform classification using inertial force, The raw material powder is passed through this flow path at a high flow rate of, for example, about 70 m / s. On the other hand, in order to realize a highly accurate classification process, the flow uniformity in the flow path is important. Therefore, in the powder classifiers of Non-Patent Documents 1 and 2, since high accuracy is required for attaching each component constituting the device, it is difficult to reduce the device cost, and adjustment of the attachment position of each component There is a problem that it takes time and effort.

  Accordingly, an object of the present invention is to solve the above-described problem, and the raw material powder conveyed in a mixed state with a gas is divided into a plurality of types of powders according to the size or density (or specific gravity) of the powder. An object of the present invention is to provide a powder classification device and a powder classification system that can reduce the adjustment of the attachment of each part for obtaining the uniformity of the flow of the raw material powder.

  In order to achieve the above object, according to one aspect of the present invention, a powder classification for classifying a raw material powder supplied in a mixed state with a gas into a first powder and a second powder. In the apparatus, a curved member having a concave curved surface, a casing enclosing the curved member in a state where a gap is formed between edges of the curved member, and a raw material powder flow for supplying raw material powder to the curved surface A first powder that is formed between the road, the outer wall surface of the bending member, and the inner wall surface of the casing, communicates with a gap between the edge of the bending member and the inner wall surface of the casing, and is applied with a suction force And the flow of the raw material powder along the curved surface from the supply portion of the raw material powder on the curved surface toward the edge by supplying the raw material powder to the curved surface from the raw material powder flow channel From the flow of the raw material powder along the curved surface at the edge of the curved member, 1 powder is sucked into the 1st powder channel, and the 2nd powder is classified as the flow of the 2nd powder which goes outside the edge of a curved member in the direction which follows a curved surface. A classification device is provided.

  According to the present invention, in a powder classification apparatus for classifying raw material powder conveyed in a mixed state with gas into a plurality of types of powder according to the size or density (or specific gravity) of the powder, It is possible to reduce the mounting adjustment of each part in order to obtain a uniform flow.

1 is a flowchart of a powder classification system including a powder classification device according to a first embodiment of the present invention. External view of powder classification apparatus of Embodiment 1 Partial expanded sectional view of the powder classification apparatus of Embodiment 1 Schematic diagram of each flow in the powder classification apparatus of Embodiment 1 (during classification process) Schematic diagram of each flow in the powder classifier of Embodiment 1 (during recovery processing) Schematic diagram of each flow in the powder classifier of Modification 1 of Embodiment 1 (during classification processing) Schematic diagram of each flow in the powder classifying apparatus of Modification 2 of Embodiment 1 (during classification processing) Schematic diagram of each flow in the powder classification device of Modification 3 of Embodiment 1 (during classification processing) Schematic diagram of each flow in the powder classification apparatus of Embodiment 2 of the present invention (during classification processing) Front view of the curved surface of the second bending member in the powder classification device of the second embodiment Schematic diagram of each flow in the powder classifier of Embodiment 2 (during recovery processing) Schematic diagram of each flow in the powder classifier of Embodiment 3 of the present invention (during classification process) External view of powder classification apparatus according to Embodiment 4 of the present invention Partial expanded sectional view of the powder classification apparatus of Embodiment 5 of this invention AA line sectional view in the powder classifier of FIG. Partial expanded sectional view of the powder classification apparatus of Embodiment 6 of this invention Partial expanded sectional view of the powder classification apparatus of Embodiment 7 of this invention Partial expanded sectional view of the powder classification apparatus of Embodiment 8 of this invention Side view (partial cross-sectional view) of a bending member in a powder classifying apparatus according to Embodiment 9 of the present invention. BB arrow line view (top view) in the bending member of FIG. Partial expanded sectional view of the powder classification apparatus of Embodiment 10 of this invention Flow chart of powder classification system according to Embodiment 11 of the present invention Flow chart of powder classification system according to Embodiment 12 of the present invention. Flow chart of powder classification system according to modification of embodiment 12

  A powder classification device according to a first aspect of the present invention is a powder classification device that classifies raw material powder supplied in a mixed state with a gas into a first powder and a second powder. A bending member including a bending member in a state where a gap is formed between the bending member and the edge of the bending member, a raw material powder flow path for supplying raw material powder to the curved surface, and an outside of the bending member A first powder passage formed between the wall surface and the inner wall surface of the casing, communicating with a gap between the edge of the bending member and the inner wall surface of the casing, and having a suction force applied thereto, By supplying the raw material powder from the raw material powder flow path to the curved surface, the curved member forms a flow of the raw material powder along the curved surface from the supply portion of the raw material powder on the curved surface toward the edge. From the flow of the raw material powder along the curved surface, the first powder flows into the first powder flow path at the edge of While being sucked, the second powder is classified as a second powder flow toward the outer side than the end edge of the curved member in the direction along the curved surface, it is intended.

  In the powder classifying apparatus according to the second invention, in the first invention, the curved member has a bowl-shaped curved surface, and the raw material powder flow path supplies the raw material powder to the inner bottom center portion of the curved surface. First annular powder between the outer wall surface of the bending member and the inner wall surface of the casing so as to communicate with the annular gap between the annular edge of the bending member and the inner wall surface of the casing A flow path is formed, and the raw material powder is supplied from the raw material powder flow path to the inner bottom center portion of the curved surface, thereby radially extending along the curved surface extending from the inner bottom central portion of the curved surface to the annular edge. While the flow of the raw material powder is formed, the first powder is sucked into the first powder flow path from the flow of the raw material powder along the curved surface at the annular edge of the bending member, and Two powders are classified as a flow of second powder that goes outward from the edge of the bending member in a direction along the curved surface. A.

  In the powder classification apparatus according to the third invention, in the second invention, the raw material powder flow path is disposed so as to oppose the inner bottom central portion of the curved surface of the curved member, and is disposed at the inner bottom central portion of the curved surface. The raw material powder is supplied so as to form a flow of the raw material powder that faces the axis of the curved member.

  According to a fourth aspect of the present invention, there is provided the powder classification apparatus according to the third aspect, wherein the raw material powder supply port in the raw material powder flow path is disposed away from the curved surface of the bending member, A classification processing space integrated with the inner space of the curved surface is disposed between the mouth and the curved surface of the curved member. In the classification processing space, the classification processing space is located outside the annular edge of the curved member in the direction along the curved surface. A part of the flow of the second powder that is directed is attracted by the flow of the raw material powder that passes from the supply port of the raw material powder passage through the central part of the classification processing space and toward the central part of the curved surface. A flow toward the central portion of the curved surface is formed along with the flow of the powder.

  According to a fourth aspect of the present invention, there is provided the powder classifying device according to the fourth aspect, wherein the guide member has a curved surface that guides the flow of the second powder toward the outside from the annular end edge of the curved member in a direction along the curved surface. Further, a classification processing space is defined by the bending member and the guide member.

  According to a sixth aspect of the present invention, there is provided a powder classifying apparatus according to the fourth or fifth aspect of the present invention, wherein the flow of the second powder is obtained by using the discharge port for discharging the raw material powder and the flow of the raw material powder passing through. An ejector having an attracting port for attracting the portion to join the flow of the raw material powder is provided at the supply port of the raw material powder channel.

  In any one of the first to sixth inventions, the powder classifying device of the seventh invention comprises a second powder flow channel arranged to face the curved surface of the curved member, and the edge of the curved member The first powder is sucked into the first powder passage from the flow of the raw material powder along the curved surface, and the first powder is directed to the second powder passage. It is classified into a flow of powder and a flow of second powder.

  The powder classification apparatus according to an eighth aspect of the present invention is the powder classification device according to any one of the second to sixth aspects, further comprising a collision member disposed at an inner bottom center portion of the curved surface of the curved member, The raw material powder is supplied so as to form a flow of the raw material powder toward the inner bottom center portion of the curved surface and along the axis of the bending member, and the raw material powder supplied from the raw material powder channel When the flow collides with the collision member, a flow of the radial raw material powder is formed along the curved surface extending from the inner bottom center portion of the curved surface to the annular end edge.

  In the powder classifying device of the ninth invention, in the eighth invention, the collision member has a conical shape, and is arranged at the center portion of the inner bottom of the curved surface so that the top portion faces the raw material powder flow path. Is.

  According to a tenth aspect of the present invention, in the eighth or ninth aspect, the outer surface of the collision member is formed as a curved surface continuous with the curved surface of the curved member.

  According to an eleventh aspect of the present invention, in any one of the first to tenth inventions, the curved surface of the bending member is a hemispherical surface.

  According to a powder classification apparatus of a twelfth invention, in any one of the second to sixth inventions, the casing has an inclined surface that is inclined with respect to the axis of the bending member so as to face the bending surface of the bending member. The curved member includes a bowl-shaped curved surface to which raw material powder is supplied from the raw material powder flow path, and an annular cylindrical inner peripheral surface extending from an end of the curved surface, and an edge of the cylindrical inner peripheral surface Are classified so that the flow of the second powder from the edge of the bending member is directed toward the inclined surface of the casing.

  A powder classification system according to a thirteenth aspect includes the first and second powder classification apparatuses according to any one of the first to twelfth aspects, the first powder flow path of the first powder classification apparatus, A powder flow path connecting the raw material powder flow path of the second powder classifier.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
A main configuration of a powder classification system including the powder classification apparatus according to the first embodiment of the present invention will be described with reference to the flowchart shown in FIG.

  As shown in FIG. 1, a powder classification system 1 includes a quantitative feeder 2, a disperser 3, a powder classification device 4, a fine powder collecting bag filter 5, a coarse powder collecting bag filter 6, and a vacuum. A pump 7 and a clean air supply unit 8 are provided.

  In the powder classification system 1 according to the first exemplary embodiment, for example, a raw material powder containing a particle size distribution of 0.1 μm to several tens of μm is mixed with a gas (that is, a solid-gas mixed state). Convey and classify into fine powder (first powder: particle size of about 0.1 μm to 1 μm, for example) and coarse powder (second powder: particle size of over 1 μm, for example) and collect with powder classification device 4 System. Moreover, as gas mixed with raw material powder, ion gas, inert gas, etc. can be used other than air.

  Such raw material powders are used in various technical fields such as fine ceramics, metal materials, polymer materials, batteries / electronic materials, composite materials, pharmaceutical materials, food materials, etc., such as electronics, energy, medicine, and food. It is intended for powders containing inorganic and organic fines. The process of selectively taking out powder having specific specifications (size, density, etc.) from the raw material powder is the powder classification process of the present invention. Further, the process of removing foreign substances other than the powder having a specific specification contained in the raw material powder from the raw material powder is also included in the powder classification process of the present invention.

  The quantitative feeder 2 is a device that quantitatively supplies the raw material powder into the powder classification system 1. In the present embodiment, for example, a micro feeder is used.

  The disperser 3 includes an ejector, and pulverizes and disperses the raw material powder supplied by the quantitative feeder 2 through the ejector. The disperser 3 may be an apparatus having a function of crushing and dispersing the raw material powder as described above, and a configuration other than the ejector may be employed. Moreover, you may comprise with a some disperser and may arrange | position just before the powder classification apparatus 4 as needed.

  The powder classifier 4 is an apparatus that selectively classifies the raw material powder dispersed in the disperser 3 and conveyed in a mixed state with gas into fine powder and coarse powder. In the powder classification device 4, classification processing is performed on the raw material powder supplied into the device. In addition, a clean air supply unit 8 is connected to the powder classifier 4 so that clean air is supplied into the apparatus. Since the classification process is performed in a state where the raw material powder is surrounded by the flow of clean air supplied from the clean air supply unit 8, it is possible to suppress the raw material powder from adhering to the inner wall surface of the apparatus, and high classification accuracy. Can be obtained. The detailed configuration of the powder classifier 4 will be described later.

  The fine powder collecting bag filter 5 collects fine powder by filtering the powder airflow containing the fine powder classified by the powder classifying device 4. Similarly, the coarse powder collecting bag filter 6 collects the coarse powder by filtering the powder airflow containing the coarse powder classified by the powder classifier 4.

  As shown in FIG. 1, in the powder classification system 1, each of the above-described device configurations is connected by a pipe line (pipe for conveying raw material powder). The vacuum pump 7 is connected to the downstream end of the entire pipe line of the powder classification system 1. By sucking the inside of the pipe line, the inside of the pipe line is maintained at a negative pressure, and is caused by the air flow of the raw material powder. Transport is performed. In the first embodiment, the vacuum pump 7 that applies a suction force to the pipe line by sucking the pipe line of the powder classification system 1 is an example of a suction device (or a suction unit).

  Opening control valves 5a and 6a, flow meters 5b and 6b, and pressure gauges 5c and 6c are provided on the outlet pipes of the fine powder collecting bag filter 5 and the coarse powder collecting bag filter 6, respectively. . Further, the pipe of the clean air supply unit 8 is branched into three pipes as will be described later, and the opening control valves 8a, 8d, 8g, flow meters 8b, 8e, 8h, And pressure gauges 8c, 8f and 8i. The balance of each flow of clean air, fine powder, and coarse powder can be controlled by adjusting each opening degree control valve so that each flow meter and pressure gauge show appropriate values.

  Next, the configuration of the powder classifier 4 will be described with reference to the drawings. An external view (partially sectional view) of the powder classifier 4 is shown in FIG. In addition, in the external view of FIG. 2, only the main components among the components of the powder classifier 4 are shown. Is not shown.

  As shown in FIG. 2, the powder classification device 4 includes a first casing 11, a second casing 12, and a third casing 13 as three generally cylindrical casings. In a state where the lower portion of the second casing 12 is disposed in the first casing 11 and the lower portion of the third casing 13 is disposed in the second casing 12, the respective casings 11 to 13 are connected to each other by flange portions. ing.

  The first casing 11 includes a coarse powder discharge cylinder 14 which is a cylindrical member positioned on the lower side thereof, and a tapered cylinder 15 having a tapered wall (inclined wall) whose inner diameter is continuously enlarged from the coarse powder discharge cylinder 14. With. A raw material powder introduction pipe 10 is disposed inside the coarse powder discharge tube 14 to define a raw material powder flow path therein. The raw material powder introduction tube 10 is an introduction portion of the raw material powder conveyed from the quantitative feeder 2 and the disperser 3 via a pipe line. The raw material powder introduction tube 10 opens in the tapered cylinder 15. Then, the raw material powder is supplied into the tapered cylinder 15. A coarse powder discharge pipe (discharge port) 16 is connected in a circumferential (tangential) direction to the coarse powder discharge cylinder 14, and the inner wall surface of the coarse powder discharge cylinder 14 and the outer wall surface of the raw material powder introduction pipe 10 are connected. A coarse powder discharge channel having an annular channel cross section is formed therebetween. The coarse powder discharge pipe 16 is connected to the coarse powder collecting bag filter 6 through a pipe line.

  A second clean air introduction pipe 17 is connected to the upper portion of the first casing 11 in a circumferential (tangential) direction. A second clean air channel having an annular channel cross section is formed between the lower outer wall surface of the second casing 12 and the inner wall surface of the first casing 11. 2 Clean air is introduced into the clean air flow path. The second clean air introduction pipe 17 is a pipe line that communicates with one of the pipe lines from the clean air supply unit 8.

  A bending member 20 having a circumferential opening edge 21 (end edge) is arranged on the lower side of the second casing 12 on the lower side in the figure. Here, a partially enlarged sectional view around the bending member 20 in the powder classifying device 4 is shown in FIG. As shown in FIG. 3, in the powder classification device 4 of the first embodiment, the bending member 20 has a substantially hemispherical curved surface (concave curved surface) 22, and an open end that is the lower end of the curved surface. The edge 21 is surrounded by the lower part of the second casing 12. Note that the bending member 20 having such a shape can also be referred to as a bowl-shaped member. The opening edge 21 of the bending member 20 is a classification position (separation position) P for classifying (separating) the raw material powder into fine powder and coarse powder. As will be described later, in the powder classification device 4 of the first embodiment, the raw material powder is classified into fine powder and coarse powder at positions other than the opening edge 21 of the bending member 20 that is the classification position P. Classification processing is performed. A first fine powder channel having an annular channel cross section is formed between the lower inner wall surface of the second casing 12 and the outer wall surface 23 of the bending member 20. In addition, the curved surface 22 of the bending member 20 is spaced apart from the supply port 10a of the raw material powder flow channel, which is the upper end of the raw material powder introduction tube 10.

  A first clean air introduction pipe 18 is disposed inside the third casing 13, and the first clean air introduction pipe 18 communicates with a central portion of the inner bottom of the bending member 20, and the cleanliness inside the bending member 20 is clean. Supply air. The first clean air introduction pipe 18 is a pipe line that communicates with one of the pipe lines from the clean air supply unit 8. The third casing 13 communicates with the second casing 12 and has a second narrow passage having an annular channel cross section formed between the inner wall surface of the third casing 13 and the outer wall surface of the first clean air introduction pipe 18. The powder flow path is communicated with the first fine powder flow path. A fine powder discharge pipe 19 is connected to the upper part of the third casing 13 in the circumferential (tangential) direction. The fine powder discharge pipe 19 is connected to the fine powder collecting bag filter 5 through a pipe line.

  A third clean air introduction pipe 26 is connected to the upper portion of the second casing 12 in the circumferential (tangential) direction. A third clean air channel having an annular channel cross section is formed between the lower outer wall surface of the third casing 13 and the inner wall surface of the second casing 12. 3 Clean air is introduced into the clean air flow path. The third clean air introduction pipe 26 is a pipe line that communicates with one of the pipe lines from the clean air supply unit 8.

  A collision member 24 that collides with the flow of the raw material powder introduced from the raw material powder introduction tube 10 is disposed in the central portion of the inner bottom of the bending member 20. The collision member 24 has a conical shape (including a shape similar to the conical shape) with a top portion directed downward in the drawing, and an outer peripheral surface 24 a is formed as a concave curved surface, and the curved surface 22 of the curved member 20. The collision member 24 is arranged so as to be smoothly continuous. In addition, a gap is formed between the bottom surface 24b of the collision member 24 and the curved surface 22 of the bending member 20, and the clean air supplied from the first clean air introduction pipe 18 is curved through this gap (flow path). It is introduced into the member 20. Further, a rod-like support member 25 is disposed in the first clean air introduction pipe 18, and a collision member 24 is attached to the lower end of the support member 25. By adjusting the vertical position of the support member 25, the size of the gap between the collision member 24 and the bending member 20 can be adjusted.

  In the powder classifying apparatus 4, an integrated space surrounded (defined) by the bending member 20 and the tapered cylinder 15 is a classification processing space S in which classification processing for the raw material powder is mainly performed. In the classification treatment space S, no member that substantially partitions the space is disposed, and the classification treatment space S is formed as one integrated space.

  Here, the schematic diagram of each flow path structure, such as raw material powder and clean air in the powder classification apparatus 4, is shown in FIG.

  As shown in FIG. 4, a raw material powder passage 31 for supplying raw material powder is formed inside the raw material powder introduction tube 10. The raw material powder flow path 31 is a flow path for supplying the raw material powder from the lower side to the classification processing space S, and specifically, toward the collision member 24 disposed in the center portion of the inner bottom of the bending member 20. And a flow path for supplying the raw material powder so as to pass through the central portion of the classification processing space S.

  A first fine powder channel 32 having an annular channel cross section is formed between the outer wall surface 23 of the bending member 20 and the inner wall surface of the second casing 12. A second fine powder channel 33 having an annular channel cross section is formed between the outer wall surface of the first clean air introduction pipe 18 and the inner wall surface of the third casing 13. The classification processing space S communicates with the first fine powder flow path 32, the first fine powder flow path 32 communicates with the second fine powder flow path 33, and the second fine powder flow path 33 communicates with the fine powder discharge pipe 19. A continuous fine powder flow path is formed. Since the fine powder discharge pipe 19 is connected to the third casing 13 in the circumferential direction, suction through the fine powder discharge pipe 19 is performed by the vacuum pump 7, so that the second cross-section having the annular channel cross section is obtained. In the fine powder flow path 33, a fine powder swirl flow is formed.

  Between the inner wall surface of the coarse powder discharge cylinder 14 and the outer wall surface of the raw material powder introduction tube 10, a coarse powder channel 34 having an annular channel cross section is formed. The coarse powder channel 34 is a channel that communicates the classification processing space S and the coarse powder discharge pipe 16. Since the coarse powder discharge pipe 16 is connected to the coarse powder discharge cylinder 14 in the circumferential direction, suction through the coarse powder discharge pipe 16 is performed by the vacuum pump 7, so that the coarse powder having a circular channel cross section is obtained. In the powder channel 34, a swirling flow of coarse powder is formed.

  A second clean air channel 35 having an annular channel cross section is formed between the lower outer wall surface of the second casing 12 and the upper inner wall surface of the first casing 11. Since the second clean air introduction pipe 17 is connected to the first casing 11 in the circumferential direction, the supply of clean air through the second clean air introduction pipe 17 causes the second clean air flow path 35 to be supplied. Inside, a swirling flow of clean air is formed along the inner wall surface of the first casing 11. The direction of the clean air swirl flow in the second clean air flow path 35 is the same as the direction of the coarse powder swirl flow in the coarse powder flow path 34.

  A third clean air channel 37 having an annular channel cross section is formed between the lower outer wall surface of the third casing 13 and the upper inner wall surface of the second casing 12. Since the third clean air introduction pipe 26 is connected to the second casing 12 in the circumferential direction, the clean air is supplied through the third clean air introduction pipe 26, whereby the third clean air flow path 37. Inside, a swirling flow of clean air is formed along the inner wall surface of the second casing 12. The direction of the clean air swirl flow in the third clean air flow path 37 is the same as that of the clean air swirl flow in the second clean air flow path 35.

  Inside the first clean air introduction pipe 18, a first clean air flow path 36 communicating with the central portion of the inner bottom of the bending member 20 is formed. The first clean air channel 36 communicates with the classification processing space S through a gap formed between the curved surface 22 of the curved member 20 and the bottom surface 24b of the collision member 24.

  A method for classifying the raw material powder in the powder classifier 4 having such a flow path configuration will be described.

  First, in the powder classifying device 4, the vacuum pump 7 is started to operate, the suction force is applied to the fine powder discharge pipe 19, and the atmosphere in the apparatus 4 is sucked through the fine powder discharge pipe 19, whereby the raw material powder The supply of the raw material powder from the body channel 31 into the device 4 is started. In the classification process according to the first embodiment, the communication between the coarse powder discharge pipe 16 and the vacuum pump 7 is closed by a valve, and suction through the coarse powder discharge pipe 16 is not performed. During the classification process, clean air is not supplied from the clean air supply unit 8 into the apparatus 4.

  As shown in FIG. 4, in the powder classification device 4, the raw material powder introduced into the classification processing space S from the raw material powder flow path 31 forms an upward raw material powder flow F <b> 1 in the drawing. The flow F1 of the raw material powder passes through the central portion of the classification processing space S, and flows as a one-way flow (mainly a one-way flow) along the axis of the bending member 20 on the curved surface 22 of the bending member 20. It collides with the collision member 24 arranged at the inner bottom center portion. Thereafter, the flow direction of the raw material powder F1 is changed along the outer peripheral surface 24a of the collision member 24 which is a concave curved surface, and the flow of the raw material powder along the outer peripheral surface 24a of the collision member 24 is changed. F2 is formed. This raw material powder flow F <b> 2 is a radial flow that spreads from the center portion of the inner bottom of the curved surface 22 of the bending member 20 to the opening edge 21.

  Next, the radial flow F <b> 2 of the raw material powder becomes a flow F <b> 3 along the curved surface 22 of the bending member 20 while being gradually changed so that the flow direction is directed toward the opening edge 21. There are no opposing wall surfaces in the vicinity of the curved surface 22 of the bending member 20, and no enclosed flow path is formed. However, since the inner wall surface of the bending member 20 is curved, the direction of the flow F3 is curved. Limited by the surface 22, a flow F3 along the curved surface 22 is formed. In this way, the direction of the flow F3 is continuously limited by the curved surface 22, so that the raw material powder flow F3 is closer to the curved surface 22 in the vicinity of the opening edge 21 of the curved member 20. The width of the flow (distance from the inner wall surface) becomes thinner toward the opening edge 21 than the central portion of the inner bottom. As a result, in the vicinity of the opening edge 21 of the bending member 20, the raw material powder flow F <b> 4 having a predetermined speed necessary for the classification process is formed while being surely directed in the direction along the curved surface 22. In particular, the flow direction of the flow F2, F3 is continuously limited by the curved surface 22 which is the inner wall surface of the bending member 20 while the flow F2, F3 of the raw material powder spreads radially, so that the center portion of the inner bottom (flow) The closer to the opening edge 21 than to F2) (flows F3, F4), the thinner the raw material powder flows.

  When the raw material powder flow F4 reaches the opening edge 21 of the bending member 20 at the classification position P, the fine powder in the raw material powder is sucked into the first fine powder flow path 32 against the inertial force. (Fine powder flow F5). On the other hand, the coarse powder in the raw material powder has an inertial force that overcomes the suction force from the first fine powder flow path 32, so that it is outside the opening edge 21 in the direction along the curved surface 22 of the curved member 20 (lower in the figure). Side) (coarse powder flow F6). In this way, at the classification position P, the raw material powder flow F4 is branched into a fine powder flow F5 and a coarse powder flow F6 by inertia force, and the fine powder and coarse powder are classified into the raw powder. Is done.

  The fine powder flow F5 sucked into the first fine powder flow path 32 is guided to the second fine powder flow path 33, becomes a swirl flow in the second fine powder flow path 33, and becomes a fine powder discharge pipe. 19 is discharged to the outside of the powder classifier 4. The coarse powder flow F <b> 6 falls into the coarse powder discharge cylinder 14 along the tapered surface of the tapered cylinder 15, or adheres to the tapered surface of the tapered cylinder 15 and is captured. Part of the coarse powder flow F6 (flow F9) forms a vortex along the raw material powder flow F1 in the classification processing space S, and joins with the raw material powder flow F1 to bend again. Heading toward the center of the inner bottom of the member 20. Thereafter, the raw material powder flow F1 including the coarse powder flow F6 becomes flows F2, F3, and F5, and classification is performed again.

  In the powder classification apparatus 4 of the first embodiment, when continuous classification processing is performed on the raw material powder, for example, the supply amount Qp of the raw material powder is set to the same air volume as the suction amount Qf of the fine powder. Is done.

  When continuous classification processing is completed in the powder classification device 4, the coarse powder collected in the device 4 is collected (or washed). Here, the flow during the recovery process in the powder classifier 4 is shown in FIG.

  First, in the powder classifier 4, the supply of the raw material powder through the raw material powder channel 31 is stopped, the communication between the fine powder discharge pipe 19 and the vacuum pump 7 is closed by a valve, and the coarse powder discharge pipe 16 and the vacuum pump 7 are in communication with each other. In this state, the operation of the vacuum pump 7 is started and the atmosphere in the apparatus 4 is sucked through the coarse powder discharge pipe 16. At the same time, supply of clean air from the clean air supply unit 8 into the apparatus 4 is started.

  As shown in FIG. 5, the clean air supplied from the first clean air flow path 36 is classified through a gap formed between the curved surface 22 of the curved member 20 and the bottom surface 24 b of the collision member 24. S is introduced. As a result, a first clean air flow F <b> 7 is formed along the curved surface 22 of the bending member 20 toward the opening edge 21. The coarse powder collected by adhering to the curved surface 22 of the bending member 20 is removed from the curved surface 22 by the flow F7 of the first clean air.

  The clean air supplied from the second clean air flow path 35 forms a second clean air flow F <b> 8 along the tapered surface of the tapered cylinder 15. Further, the clean air supplied from the third clean air flow path 37 forms a third clean air flow F10 along the inner wall surface of the second casing 12 and the outer wall surface 23 of the bending member 20. The coarse powder adhering to the tapered surface of the tapered cylinder 15, the outer wall surface 23 of the bending member 20, and the inner wall surface of the second casing 12 is removed by the flows F8 and F10 of the second and third clean air.

  Furthermore, the first to third clean air flows F7, F8, and F10 merge to form a fourth clean air flow F11 along the tapered surface of the tapered cylinder 15. The flow F11 of the fourth clean air is guided to the coarse powder flow path 34 in the coarse powder discharge cylinder 14 while removing the coarse powder adhering to the tapered surface. Then, by the swirl flow formed in the coarse powder discharge cylinder 14, the coarse powder is discharged out of the apparatus 4 through the coarse powder discharge pipe 16 together with the coarse powder collected in the coarse powder discharge cylinder 14. Thereafter, these coarse powders are collected by the coarse powder collecting bag filter 6.

  When these recovery processes are performed, the total of the first clean air supply amount Q1, the second clean air supply amount Q2, and the third clean air supply amount Q3 is the same as the coarse powder suction amount Qr. The air volume balance is set so that

  Here, the mechanism of the classification process for the raw material powder in the powder classifying apparatus 4 of the first embodiment will be described. This mechanism is a mechanism that the inventors of the present application infer from the technical viewpoint of powder classification based on the configuration of the powder classification apparatus 4 of the first embodiment.

  In the classification process for the raw material powder in the first embodiment, the continuous inertial collision (impactor) using the curved surface 22 of the curved member 20 and the separation using the inertial force at the opening edge 21 of the curved member 20. It is thought that this is done.

  In the conventional inertial collision, the flow of the raw material powder is collided from the direction perpendicular to the flat plate (collision plate) to collect the coarse powder on the flat plate surface. On the other hand, the fine powder deviates from the collision position of the raw material powder without colliding with the flat plate along with the flow spreading along the surface of the flat plate. Thereby, the raw material powder is classified into coarse powder and fine powder. However, in such a conventional inertial collision, since a flat plate is used as the collision plate, there is only one collision opportunity between the flow of the raw material powder and the flat plate. Once the coarse powder collected on the flat plate may re-scatter from the surface of the flat plate, in such a case, since the collision opportunity is only once, the scattered coarse powder is mixed into the fine powder, A highly accurate classification process cannot be performed.

  On the other hand, in the inertial collision of the first embodiment, the curved member 20 is used as the collision plate instead of a flat plate. Since the collision surface is the curved surface 22, the flow direction of the raw material powder spreading from the inner bottom center portion (collision position) of the curved surface 22 is continuously limited by the curved surface 22. Thereby, the state in which the flow of the raw material powder collides with the curved surface 22 is continuously created. Therefore, the re-scattered coarse powder has a chance to collide with the curved surface 22 a plurality of times, and even if the scattering occurs, the coarse powder can be collected again by the curved surface 22, which is compared with the conventional inertial collision. Thus, highly accurate classification processing can be performed.

  Furthermore, in the classification process according to the first embodiment, separation is performed using the inertial force at the opening edge 21 of the bending member 20. The flow direction F2 of the raw material powder that spreads radially from the inner bottom center portion of the curved surface 22 is closer to the opening edge 21 than the inner bottom center portion (flow F2) because the flow direction is limited by the curved surface 22. The raw material powder flow (flows F3 and F4) becomes thinner. As a result, in the vicinity of the opening edge 21 of the bending member 20, the raw material powder flow F <b> 4 having a predetermined speed necessary for the classification process is formed while being surely directed in the direction along the curved surface 22. Thus, with respect to the raw material powder flow F4 oriented in a predetermined direction and having a predetermined velocity, the opening edge 21 is set as the classification position P, and the fine powder flow F5 and the coarse powder flow using inertial force. By separating into the flow F6, the fine powder and coarse powder are classified into the raw powder.

  As described above, in the first embodiment, the raw material powder is supplied from the raw material powder channel 31 to the inner bottom center portion of the curved surface 22 of the curved member 20, thereby continuously using the curved surface 22 of the curved member 20. The material powder is classified by at least two actions, i.e., an inertial impact (impactor) and separation using inertial force at the opening edge 21 of the bending member 20. Therefore, highly accurate classification processing can be performed. Moreover, even when the flow rate of the raw material powder is reduced, it is possible to obtain a classification accuracy equivalent to that of the conventional classification process.

  Further, in the classification processing space S, a large vortex is formed so that a part of the coarse powder flow F6 (flow F9) is directed to the raw material powder flow F1. Thereby, the classification process by at least two actions of continuous inertial collision (impactor) using the curved surface 22 of the bending member 20 and separation using inertial force at the opening edge 21 of the bending member 20 is repeated. Done. Therefore, since the classification process can be performed again on the coarse powder that could not be collected in one cycle classification process, the collection efficiency of the coarse powder separated from the raw material powder can be increased.

  According to the powder classifying device 4 of the first embodiment as described above, the raw material powder flow F1 supplied from the raw material powder channel 31 to the central portion of the inner bottom of the bending member 20 collides with the collision member 24. By doing so, it is possible to form radial raw material powder flows F3 and F4 along the curved surface 22 of the bending member 20 extending from the central portion of the inner bottom of the bending member 20 to the opening edge 21. That is, the flow direction F1 of the raw material powder toward the inner bottom center portion of the bending member 20 is largely changed (turned greatly) by the collision member 24 and the bending member 20, and the curved surface 22 of the bending member 20. Flows F3 and F4 are formed. And the classification process is performed into the fine powder and coarse powder with respect to raw material powder by making the opening edge 21 of the bending member 20 into the classification position P.

  Further, by being along the curved surface 22, the flow direction can be adjusted as a flow along the curved surface 22 at the classification position P, and the width of the flow can be reduced. A predetermined speed required for processing can be obtained. Therefore, at the classification position P, a reliable classification process can be performed on the raw material powder flow F4. In particular, since the width of the flow along the curved surface 22 can be reduced, the bending radius of the flow path toward the first fine powder flow path 32 at the classification position P can be reduced. Therefore, it becomes possible to reduce the particle diameter (that is, the cut diameter) of the fine powder separated from the raw material powder using the inertial force, and it is possible to realize classification processing with higher accuracy.

  As described above, in the powder classification device 4 of the first embodiment, it is not necessary to form a flow path surrounded by the opposing wall surfaces in the vicinity of the classification position P, and the curved member 20 opened to the classification processing space S is formed. Can be used to form the raw material powder flows F3 and F4 along the curved surface 22 for classification. Therefore, the labor for adjusting the flow path can be greatly reduced, the apparatus configuration can be simplified, and a powder classification apparatus that does not require high apparatus accuracy like the conventional apparatus can be provided.

  In the powder classifying device 4 of the first embodiment, the position of the bending member 20 can be adjusted with respect to the casing (the first casing 11, the second casing 12, and the third casing 13). For example, by adjusting the position of the bending member 20 with respect to the casing, the position of the classification position P with respect to the casing can be adjusted, and the particle diameter (cut diameter) to be classified can be adjusted. It is also possible to adjust the position of the raw material powder introduction tube 10 (the raw material powder channel 34) with respect to the bending member 20.

  Further, in the powder classifying device 4 of the first embodiment, the flow direction F1 of the raw material powder supplied from the raw material powder channel 31 is made to collide with the collision member 24, so that the direction of the flow is greatly changed. Specifically, the classification process is performed by forming the flows F3 and F4 along the curved surface 22 of the bending member 20. In such a configuration, for example, the classification process can be performed at a speed of the raw material powder flow F4 at the classification position P of about 20 m / s, and the classification process can be realized at a lower speed than in the conventional apparatus.

(Modification 1 of Embodiment 1)
The classification process in the powder classification apparatus 4 according to the first embodiment is not limited to the above case, and can take various other configurations. A classification process according to the first modification of the first embodiment will be described with reference to FIG.

  As shown in FIG. 6, in the classification process of the first modification, when the classification process is performed, the coarse powder discharge pipe 16 and the vacuum pump 7 are communicated, and the coarse powder is sucked and discharged through the coarse powder flow path 34. This is different from the classification process of the first embodiment described above.

  Specifically, when suction is performed through the coarse powder flow path 34, the coarse powder flow F6 branched at the classification position P is combined with the coarse powder flow F12 that is actively directed to the coarse powder flow path 34 by this suction. Become. The coarse powder collected by the coarse powder flow F12 is fed into the coarse powder discharge cylinder 14, and the coarse powder becomes a swirl flow in the coarse powder discharge cylinder 14, and is out of the apparatus 4 through the coarse powder discharge pipe 16. The coarse powder is collected by the coarse powder collecting bag filter 6. In the classification process of the first modification, for example, the air volume balance is set such that the sum of the fine powder suction amount Qf and the coarse powder suction amount Qr is the same as the raw material powder supply amount Qp. . The fine powder suction amount Qf is set to be larger than the coarse powder suction amount Qr.

  According to the classification process of the first modification, the coarse powder that has fallen from the classification treatment space S into the coarse powder flow path 34 is prevented from being caught in the flow in the classification treatment space S again. Can be discharged out of the device 4. Therefore, efficient classification processing can be realized.

(Modification 2 of Embodiment 1)
Next, the classification process according to the second modification of the first embodiment will be described with reference to FIG.

  As shown in FIG. 7, in the classification process of the second modification, when the classification process is performed, clean air is supplied from the second clean air flow path 35, and the tapered surface of the tapered cylinder 15 in the first casing 11. Is different from the classification process of the first modification of the first embodiment in that the second clean air flow F8 along the line is formed.

  In the classifying process of the second modification, for example, the coarse powder suction amount Qr = second clean air supply amount Q2, and the total of the raw material powder supply amount Qp and the second clean air supply amount Q2 is: The air volume balance is set to be the same as the sum of the fine powder suction amount Qf and the coarse powder suction amount Qr.

  In the classification process of the second modification example, since the second clean air flow F8 along the tapered surface of the tapered cylinder 15 in the first casing 11 is formed when the classification process is performed, the first casing Adhesion and accumulation of coarse powder on the 11 taper surface can be suppressed. Further, a part of the fine powder that could not be directed from the opening edge 21 of the bending member 20 at the classification position P to the first fine powder flow path 32 is included in the coarse powder flow F6. However, by setting the air volume balance as described above, the fine powder contained in the coarse powder flow F6 can be directed to the raw material powder flow F1 by the flow F9. Thereby, the classification process can be performed again, and the fine powder can be directed to the first fine powder flow path 32 through the flows F1 to F5. Therefore, the collection efficiency of the fine powder separated from the raw material powder can be increased, and an efficient classification process can be realized.

(Modification 3 of Embodiment 1)
Next, the classification process according to the third modification of the first embodiment will be described with reference to FIG.

  As shown in FIG. 8, in the classification process of the third modification, when the classification process is performed, clean air is supplied from the first clean air flow path 36 and the first along the curved surface 22 of the bending member 20. In the point which forms the flow F7 of clean air, it differs from the classification process of Embodiment 1. FIG.

  According to the classification process of Modification 3 as described above, since the first clean air flow F7 is formed along the curved surface 22 of the bending member 20, the raw material powder is applied to the curved surface 22 of the bending member 20. Adhesion is suppressed. In such a configuration, it is difficult to obtain the action due to the continuous inertial impact (impactor) using the curved surface 22 of the bending member 20 among the classification processes by at least two actions, but coarse powder is applied to the curved surface 22. Such a classification process can be adopted when there is a circumstance such as not wanting to adhere. Moreover, the raw material powder subjected to the classification treatment includes those that are easily collected by inertial collision and those that are difficult to be collected. For example, when performing a classification process on a raw material powder that is difficult to be collected by inertial collision, considering that it is difficult to obtain the effect of continuous inertial collision using the curved surface 22, Classification processing may be employed. Further, by forming the first clean air flow F7 along the curved surface 22 of the curved member 20, the raw material powder flow F4 along the curved surface 22 can be adjusted. Thereby, the classification efficiency using the inertia force in the classification position P can be improved.

  In addition, the apparatus structure which forms the flow F7 of the 1st clean air along the curved surface 22 of the bending member 20 is not restricted only about such a structure. For example, a form in which the curved member itself is formed of a porous member and clean air is supplied to the curved surface side of the curved member through the porous member may be employed. In this case, the region where the effect of inertial collision on the curved surface is desired (for example, the central region of the curved surface) is not a porous member, and other regions are formed by the porous member. Also good.

  Moreover, you may employ | adopt the structure which united the classification process concerning the above-mentioned modification 1 and modification 3. FIG. In the case of this configuration, while performing the classification process of separating the raw material powder into coarse powder and fine powder, while suppressing the coarse powder from adhering to the curved surface 22, the separated coarse powder is actively attracted by suction. It can be recovered.

  Moreover, you may employ | adopt the structure which match | combined the classification process concerning the above-mentioned modification 2 and modification 3. FIG. In the case of this configuration, since the raw powder adheres to and accumulates on the inner wall surface of the classification processing space S, the continuous processing is longer than the continuous processing time in the classification processing of the first embodiment and the first to third modifications. Realize time.

  In addition, you may employ | adopt the structure by the arbitrary combinations of the modifications 1-3.

(Embodiment 2)
Next, a powder classifying apparatus 104 according to the second exemplary embodiment of the present invention will be described with reference to the drawings. FIG. 9 shows a configuration in the vicinity of the classification processing space S in the powder classifying device 104. In addition, the same reference number is attached | subjected to the same structure as the structure of the powder classification apparatus 4 of above-mentioned Embodiment 1, and the description is abbreviate | omitted.

  As shown in FIG. 9, the powder classification apparatus 104 of the second embodiment is the above-described implementation in that a second bending member 40 (guide member) is additionally provided in the first casing 11. The powder classifying apparatus 4 of the first embodiment has a different configuration. Specifically, in the first casing 11, a first bending member 20 that opens downward in the figure, and a second bending member 40 that opens upward in the figure so as to face the first bending member 20. Is arranged.

  The second bending member 40 has, for example, a curved surface 42 having the same curvature and shape as the first bending member 20, but may have a curved surface having a different curvature or shape. As described above, the first bending member 20 and the second bending member 40 are arranged to face each other, whereby the classification processing space S is defined by the curved surfaces 22 and 42.

  The raw material powder introduction tube 10 is disposed so as to penetrate the center portion of the inner bottom of the second bending member 40. Here, a front view of the curved surface 42 of the second bending member 40 is shown in FIG. As shown in FIGS. 9 and 10, coarse powder drop openings 43 are formed in the second bending member 40 as a plurality of openings so as to surround the periphery of the raw material powder introduction tube 10. These coarse powder dropping ports 43 communicate the classification processing space S and the coarse powder flow path 34.

  As shown in FIG. 9, the annular opening end edge 41 of the second bending member 40 is disposed to face the annular opening end edge 21 of the first bending member 20 with a gap. The gap serves as an annular fine powder suction port 44 and communicates with the first fine powder flow path 32.

  In the powder classification apparatus 104 having such a configuration, the classification processing space S can be reliably defined by the first and second bending members 20 and 40. Therefore, as shown in FIG. 9, in the classification process, the coarse powder flow F6 can be guided to flow along the curved surface 42 of the second bending member 40, and a part of the coarse powder flow F6 is formed. A coarse powder flow F9 directed toward the raw material powder flow F1 can be stably formed. Therefore, in the classification processing space S, large vortex flows circulating with the flows F1 to F4, F6, and F9 can be stably formed, and stable classification processing can be realized.

  At the classification position P, the fine powder flow F5 branched from the raw material powder flow F4 passes through the annular fine powder suction port 44 and is sucked into the first fine powder flow path 32. The coarse powder separated from the raw material powder is carried by the coarse powder flow F6 along the curved surface 42 of the second bending member 40 and falls into the coarse powder flow path 34 through the coarse powder drop port 43. And recovered.

  Further, as shown in FIG. 11, when the coarse powder recovery process (or cleaning process) is performed in the powder classifier 104 having such a configuration, the first to third clean air flow paths 36, 35, By supplying clean air from 37, the coarse powder adhering to each wall surface can be removed and reliably recovered.

(Embodiment 3)
Next, the powder classification apparatus 204 concerning Embodiment 3 of this invention is demonstrated using drawing. FIG. 12 shows a configuration in the vicinity of the classification processing space S in the powder classification apparatus 204 of the third embodiment. In addition, the same reference number is attached | subjected to the same structure as the structure of the powder classification apparatus 4 of above-mentioned Embodiment 1, and the description is abbreviate | omitted.

  In the powder classification apparatus 204 of the third embodiment, the raw material powder introduction pipe 10 is eliminated (or closed), and the first clean air introduction pipe 18 is used as the raw material powder flow path 50 as described above. The configuration is different from that of the first embodiment. Only this different configuration will be described below. In addition, the same reference number is attached | subjected to the same structure as the structure of the powder classification apparatus 4 of above-mentioned Embodiment 1, and the description is abbreviate | omitted.

  As shown in FIG. 12, in the powder classifier 204, the raw material powder introduction pipe is not provided, and the raw material powder is the raw material powder corresponding to the first clean air introduction pipe 18 in the apparatus 4 of the first embodiment. Through the body introduction tube 218, it is supplied to the central portion of the inner bottom of the curved surface 22 of the bending member 20. The raw material powder flow F21 passing through the raw material powder introduction pipe 218 collides with the bottom surface 24b of the collision member 24 to become a raw material powder flow F22 that spreads radially.

  The radial raw material powder flow F <b> 22 becomes a flow along the curved surface 22 of the bending member 20 and travels toward the opening edge 21 of the bending member 20. At this time, coarse powder adheres to the curved surface 22 and is collected by the action of continuous inertial collision using the curved surface 22 of the curved member 20. Thereafter, when the raw material powder flow F22 reaches the opening edge 21 (classification position P) of the bending member 20, the fine powder in the raw material powder enters the first fine powder channel 32 against the inertial force. Aspirated (fine powder flow F23). On the other hand, the coarse powder in the raw material powder travels outward (downward in the figure) from the opening edge 21 in the direction along the curved surface 22 of the curved member 20 (coarse powder flow F24). As a result, at the classification position P, the raw material powder flow F22 is branched into a fine powder flow F23 and a coarse powder flow F24 by an inertia force, and the fine powder and the coarse powder are classified into the raw powder. Done.

  The fine powder flow F23 sucked into the first fine powder flow path 32 is guided to the second fine powder flow path 33, becomes a swirl flow in the second fine powder flow path 33, and becomes a fine powder discharge pipe. 19 is discharged to the outside of the powder classifier 4. The coarse powder flow F <b> 24 falls into the coarse powder discharge cylinder 14 along the tapered surface of the tapered cylinder 15, or adheres to the tapered surface of the tapered cylinder 15 and is captured.

  As described above, according to the powder classification device 204 of the third embodiment, the curved surface 22 of the bending member 20 can be used without using the raw material powder flow channel disposed so as to face the curved surface 22 of the bending member 20. By supplying the raw material powder to the center portion of the inner bottom and forming the radial raw material powder flow F22, the classification process by at least two actions described above can be realized.

  In the above description, the case where the raw material powder flow F21 passing through the raw material powder introduction pipe 218 collides with the bottom surface 24b of the collision member 24 to form a radially spreading raw material powder flow F22 is described. However, the shape of the bottom surface 24b of the collision member 24 is set to a shape that smoothly guides the flow of the raw material powder from the flow F21 to the flow F22 (for example, a shape like the outer peripheral surface 24a of the collision member 24). Also good.

(Embodiment 4)
Next, a powder classifying apparatus 304 according to the fourth embodiment of the present invention will be described with reference to the drawings. FIG. 13 shows an external view (partially sectional view) of the powder classifier 304 of the fourth embodiment. In addition, the same reference number is attached | subjected to the same structure as the structure of the powder classification apparatus 4 of above-mentioned Embodiment 1, and the description is abbreviate | omitted.

  As shown in FIG. 13, the powder classification device 304 of the fourth embodiment is curved such that the second casing 312 surrounds the bending member 20 from the outer surface side as compared with the powder classification device 4 of the first embodiment. It is different in that it is formed into a shape. Only this different configuration will be described below.

  As shown in FIG. 13, the second casing 312 is formed in a curved shape so as to surround the bending member 20 from the outer surface side, and the outer wall surface 23 of the bending member 20 and the inner wall surface (curved surface) of the second casing 312. The 1st fine powder flow path 332 is formed between. The first fine powder channel 332 is formed to have a constant channel width, for example.

  In addition, a second fine powder flow path 333 is formed between the inner wall surface of the third casing 313 and the outer wall surface of the first clean air introduction pipe 18, and a lower portion of the second fine powder flow path 333 is The first fine powder channel 332 has substantially the same channel width as the channel width. Further, the fine powder discharge pipe 19 provided in the third casing 313 is configured to be used also as a third clean air introduction pipe.

  In the powder classifier 304 having such a configuration, the third clean air introduction pipe can be used also as the fine powder discharge pipe 19, so that it is used for fine powder discharge during the classification process and is collected (or washed). Sometimes it can be used for clean air supply. Therefore, the apparatus configuration can be simplified. Moreover, since the flow path widths of the first fine powder flow path 332 and the second fine powder flow path 333 can be maintained at a substantially constant width, a stable flow of fine powder can be formed. Furthermore, since the channel widths of the first fine powder flow channel 332 and the second fine powder flow channel 333 are set to be constant and narrow as compared with the first embodiment, clean air is discharged during the recovery process (cleaning process). By introducing, the fine powder adhering to the channel wall surface can be effectively removed. Note that, from the viewpoint of manufacturing cost of the powder classifier 304, for example, the second casing 312 may be conical.

(Embodiment 5)
Next, a powder classifying apparatus 604 according to a fifth embodiment of the present invention will be described with reference to the drawings. FIG. 14 shows a partially enlarged cross-sectional view of the powder classifier 604 of the fifth embodiment. FIG. 15 is a cross-sectional view taken along line AA in the powder classifier 604 of FIG. In addition, the same reference number is attached | subjected to the same structure as the structure of the powder classification apparatus 4 of above-mentioned Embodiment 1, and the description is abbreviate | omitted.

  As shown in FIGS. 14 and 15, in the powder classification apparatus 604 of the fifth embodiment, a plurality of second clean air introduction pipes 617 are connected to the upper portion of the first casing 11 in the circumferential direction. . For example, the plurality of second clean air introduction pipes 617 may be provided at an interval (pitch) of 180 degrees in the circumferential direction of the first casing 11 (shown by a solid line in FIG. 15), or 45 degrees. They may be provided at intervals (indicated by a two-dot chain line in FIG. 15). In addition, the second clean air introduction pipes 617 are preferably connected in the same direction in the circumferential direction of the first casing 11.

  By providing the plurality of second clean air introduction pipes 617 in this way, a uniform swirling flow by clean air can be formed between the lower outer wall surface of the second casing 12 and the inner wall surface of the first casing 11. .

(Embodiment 6)
Next, a powder classifying apparatus 704 according to the sixth embodiment of the present invention will be described with reference to the drawings. FIG. 16 shows a partially enlarged cross-sectional view of the powder classifying apparatus 704 of the sixth embodiment. In addition, the same reference number is attached | subjected to the same structure as the structure of the powder classification apparatus 4 of above-mentioned Embodiment 1, and the description is abbreviate | omitted.

  As shown in FIG. 16, in the powder classification apparatus 704 of the sixth embodiment, the supply port 710a (raw material powder flow channel outlet: upper end in the drawing) of the raw material powder introduction pipe 710 is the center of the inner bottom of the bending member 20. It is arranged at a position closer to the part. Specifically, in FIG. 16, the supply port 710 a of the raw material powder introduction tube 710 is located in the inner space of the bending member 20.

  The raw material powder supplied from the supply port 710a of the raw material powder introduction tube 710 toward the central portion of the inner bottom of the bending member 20 proceeds in a direction substantially along the raw material powder introduction tube 710, but gradually spreads around. Try to disperse. In particular, as the distance from the supply port 710a of the raw material powder introduction tube 710 to the collision member 24 at the center of the inner bottom of the bending member 20 becomes longer, the amount of the raw material powder dispersed to the periphery also increases. In addition, the distance from the supply port 710a of the raw material powder introduction tube 710 to the collision member 24 also affects the supply speed of the raw material powder, and the supply speed of the raw material powder decreases as the distance increases.

  However, as in the sixth embodiment, by positioning the supply port 710a of the raw material powder introduction tube 710 in the inner space of the bending member 20, from the supply port 710a of the raw material powder introduction tube 710 to the collision member 24. The distance can be shortened. Therefore, it is possible to increase the amount of coarse powder collected by colliding with the curved surface 22 while suppressing the decrease in the supply speed of the raw material powder while reducing the amount of the raw material powder dispersed around. it can. That is, the effect of collecting coarse powder by the impactor can be enhanced. In order to obtain a higher impactor effect, the distance L from the supply port 710a of the raw material powder introduction tube 710 to the curved surface 22 of the bending member 20, and the diameter l of the supply port 710a of the raw material powder introduction tube 710 Is preferably set in a range of about L / l = 1 to 3. Further, by setting the raw material powder introduction tube 710 (raw material powder flow path) so that the position can be adjusted with respect to the bending member 20, the distance L can be easily adjusted, and the classified particle diameter (cut) Diameter) can be adjusted.

(Embodiment 7)
Next, a powder classifying apparatus 804 according to Embodiment 7 of the present invention will be described with reference to the drawings. FIG. 17 shows a partially enlarged cross-sectional view of the powder classifier 804 of the seventh embodiment. In addition, the same reference number is attached | subjected to the same structure as the structure of the powder classification apparatus 4 of above-mentioned Embodiment 1, and the description is abbreviate | omitted.

  As shown in FIG. 17, in the powder classifier 804 of the seventh embodiment, the central angle θ to the opening edge 821 of the bending member 820 is set to an angle smaller than 180 degrees. Thus, even when the central angle θ of the bending member 820 is set as an angle smaller than 180 degrees, as in the above-described embodiment, the action by the inertial collision and the action by the separation using the inertial force are performed. Classification processing using can be performed. The central angle θ up to the opening edge 821 of the bending member 820 is set according to the required action due to inertial collision and the action due to separation using inertial force. For example, by setting the central angle θ to an angle smaller than 180 degrees, the distance (the path of the raw material powder) of the curved surface 820 that can obtain the effect of continuous inertial collision is shortened, while the first at the classification position P. The ratio of the fine powder toward the fine powder flow path 32 tends to increase.

(Embodiment 8)
Next, a powder classifying apparatus 904 according to Embodiment 8 of the present invention will be described with reference to the drawings. FIG. 18 shows a partially enlarged cross-sectional view of the powder classifier 904 of the eighth embodiment. In addition, the same reference number is attached | subjected to the same structure as the structure of the powder classification apparatus 4 of above-mentioned Embodiment 1, and the description is abbreviate | omitted.

  As shown in FIG. 18, in the powder classifier 904 of the eighth embodiment, the bowl-shaped curved member 920 includes a substantially hemispherical curved surface 922 to which raw material powder is supplied from the raw material powder flow path. And an annular cylindrical inner peripheral surface 991 extending from the end of the curved surface 922. The annular cylindrical inner peripheral surface 991 is formed to extend downward from the end portion of the curved surface 922, and the annular lower end portion of the cylindrical inner peripheral surface 991 is an opening edge where the classification position P is 921.

  Further, the taper surface 15a of the taper cylinder 15 of the first casing 11 constituting the casing of the powder classifier 904 is with respect to the axis (center axis) of the bending member 920 so as to face the bending surface 922 of the bending member 920. The slope is inclined. The cylindrical inner peripheral surface 991 is formed to extend in a direction along the axis of the bending member 920, and extends in a direction toward the tapered surface 15a.

  According to such a configuration, the raw material powder flows F3 and F4 oriented in the direction along the curved surface 922 of the bending member 920 are more stably oriented on the cylindrical inner peripheral surface 991. Become. Therefore, the coarse powder flow F6 from the lower end of the cylindrical inner peripheral surface 991 (opening edge 921 of the bending member 920) is classified at the classification position P so as to go to the tapered surface 15a of the tapered cylinder 15. Therefore, the coarse powder flow F6 can collide with the tapered surface 15a, and the coarse powder can be collected by the tapered surface 15a.

(Embodiment 9)
Next, a powder classifying apparatus according to Embodiment 9 of the present invention will be described with reference to the drawings. FIG. 19 shows a side view (partially sectional view) of the bending member 1020 provided in the powder classification device of the ninth embodiment. Further, FIG. 20 shows a BB line arrow view (top view) of the bending member 1020 of FIG. In addition, the same reference number is attached | subjected to the same structure as the structure of the powder classification apparatus 4 of above-mentioned Embodiment 1, and the description is abbreviate | omitted.

  As shown in FIGS. 19 and 20, the curved surface 1022 of the bending member 1020 has a polyhedral structure constituted by a plurality of surfaces 1022a, 1022b, 1022c, and 1022d having different angles. It may be difficult to manufacture a curved member having a substantially hemispherical curved surface, and it may be difficult to manufacture a uniform angular distribution of the curved surface with respect to the central axis of the curved member. is there. In such a case, the curved member 1020 can be more easily manufactured by forming the curved surface as a polyhedral structure.

  In the polyhedral structure, it is preferable that substantial disturbance does not occur in the flow of the raw material powder at the connection positions of the surfaces at different angles (that is, the portions where the angles change). Thus, the polyhedral structure that does not cause substantial disturbance in the flow of the raw material powder at the connection position between the surfaces substantially constitutes the curved surface in the present invention, and is included in the scope of the present invention. . For example, as shown in FIGS. 19 and 20, a polyhedral structure (a configuration of four or more layers) constituted by four or more surfaces substantially constitutes a curved surface in the present invention.

(Embodiment 10)
Next, a powder classifying apparatus 1104 according to the tenth embodiment of the present invention will be described with reference to the drawings. FIG. 21 shows a partially enlarged cross-sectional view of the powder classifying apparatus 1104 of the tenth embodiment. In addition, the same reference number is attached | subjected to the same structure as the structure of the powder classification apparatus 4 of above-mentioned Embodiment 1, and the description is abbreviate | omitted.

  As shown in FIG. 21, in the powder classification apparatus 1104 of the tenth embodiment, an ejector 1111 connected to a supply port (raw material powder flow channel outlet) 1110a of the raw material powder introduction tube 1110 is provided. The ejector 1111 includes an induction port 1112 that attracts a part of the coarse powder flow F9 around the raw material powder introduction pipe 1110 to join the raw powder flow, and the coarse powder sucked through the induction port 1112. And a discharge port 1113 that joins and discharges the raw material powder supplied through the supply port 1110a of the raw material powder introduction tube 1110.

  By using the ejector 1111 in this way, a part of the coarse powder flow F9 is actively attracted into the ejector 1111 and the raw powder flow F1 in a state where the coarse powder is combined with the raw powder. Can be discharged. Therefore, it becomes easy to form the coarse powder flow F9 in the classification processing space S, and the same speed as the raw powder flow F1 can be given to the coarse powder attracted by the ejector 1111. Classification processing can be performed.

(Embodiment 11)
Next, the powder classification system 401 concerning Embodiment 11 of this invention is demonstrated. FIG. 22 is a schematic configuration diagram of a powder classification device in the powder classification system 401 of the eleventh embodiment. In FIG. 22, the illustration of the peripheral configuration of the powder classifier such as the quantitative feeder is omitted.

  As shown in FIG. 22, the powder classification system 401 includes two powder classification apparatuses 4A and 4B. As the powder classification devices 4A and 4B, a case where the device 4 of the first embodiment is applied will be described as an example, but devices of other embodiments may be applied.

  The two powder classifiers 4A and 4B are arranged in parallel to the common raw material powder supply line 451. Specifically, a common raw material powder line 451 is branched and connected in parallel to the two powder classifiers 4A and 4B, and the powder classifiers communicated on this branch line. Switching valves 452A and 452B for switching are provided. Further, a common fine powder collection line 453 is branched and connected in parallel to the two powder classifiers 4A and 4B, and switching for switching the powder classifier communicated on the branch line is performed. Valves 454A and 454B are provided. Further, clean air introduction lines 455A and 455B and coarse powder collection lines 456A and 456B are connected to the respective powder classifiers 4A and 4B.

  In such a powder classification system 401, for example, the switching valves 452A and 454A are opened, the switching valves 452B and 454B are closed, and classification is performed by the powder classification device 4A (the device on the left side in the drawing). Then, clean air is introduced by the powder classifier 4B (the apparatus on the right side in the figure) to perform the coarse powder recovery process (or cleaning process). Thereafter, when a predetermined time elapses, the switching valves 452A and 454A are closed and the switching valves 452B and 454B are opened. In this state, while performing classification processing with the powder classification device 4B, clean air is introduced with the powder classification device 4A, and coarse powder recovery processing (or cleaning processing) is performed.

  In this way, continuous classification processing can be performed in the powder classification system 401 by connecting the two powder classification apparatuses 4A and 4B in parallel and switching the classification processing and the recovery processing alternately. It becomes possible.

(Embodiment 12)
Next, a powder classification system 501 according to the twelfth embodiment of the present invention will be described. FIG. 23 is a schematic configuration diagram of a powder classification device in the powder classification system 501 of the twelfth embodiment. In FIG. 23, the peripheral configuration of the powder classifier such as a quantitative feeder is not shown.

  As shown in FIG. 23, the powder classification system 501 includes two powder classification apparatuses 4A and 4B. As the powder classification devices 4A and 4B, a case where the device 4 of the first embodiment is applied will be described as an example, but devices of other embodiments may be applied.

  The two powder classifiers 4A and 4B are arranged in series with respect to the raw material powder supply line 551. That is, the raw material powder supply line 551 is connected to the raw material powder introduction pipe 10A of the powder classification device 4A, and the fine powder discharge pipe 19A of the powder classification device 4A is introduced to the raw material powder of the powder classification device 4B. It is connected to the tube 10B. Further, the fine powder discharge pipe 19B of the powder classifier 4B is connected to a fine powder collection line 552. The coarse powder discharge pipes 16A and 16B of the powder classifiers 4A and 4B are connected to a common coarse powder collection line 553. Note that clean air introduction lines 554 and 555 are connected to the respective powder classifiers 4A and 4B.

  In such a powder classification system 501, classification processing is performed in the powder classification device 4A, and the fine powder separated from the raw material powder is supplied to the next powder classification device 4B to be powder classified. The fine powder can be separated by further classifying the fine powder in the apparatus 4B. Therefore, highly accurate classification processing can be realized. In particular, such a direct multi-stage classification process can be realized only by utilizing the feature of the apparatus of the present invention that the classification process can be realized at a low speed as compared with the conventional apparatus.

  Further, in the powder classification system 501 of FIG. 23, the coarse powder separated in each of the two powder classifiers 4A and 4B is returned to the raw material powder supply line 551 on the upstream side of the powder classifier 4A. May be. In such a structure, since the fine powder remaining in the coarse powder can be separated and recovered by re-classification, a high recovery rate can be realized.

  Further, like the powder classification system 561 according to the modification shown in FIG. 24, the coarse powder discharge pipe 16A of the powder classification apparatus 4A is connected to the raw material powder introduction pipe of the powder classification apparatus 4B via the coarse powder collection line 576. A configuration may be adopted in which the coarse powder discharge pipe 16B of the powder classification device 4B is connected to the raw material powder supply line 551 via the coarse powder collection line 577. Fine powder separated by the powder classifiers 4A and 4B is collected through fine powder collection lines 572 and 573. In such a configuration, the fine powder and the coarse powder are separated from the raw powder by the powder classification device 4A to collect the fine powder, and then the separated coarse powder is supplied to the powder classification device 4B. The fine powder remaining in the coarse powder can be separated and recovered. Furthermore, since the coarse powder separated by the powder classifying device 4B is returned to the raw material powder supply line 551 of the powder classifying device 4A and the classification process is performed again, a high recovery rate can be realized.

  Further, a dispersion mechanism (for example, an ejector) for dispersing the powder is provided between the powder classifiers 4A and 4B or between the first powder classifier and the second powder classifier. You may make it supply to a powder classifier in the state which disperse | distributed powder. By doing in this way, classification processing can be performed with high accuracy.

  In the above-described embodiment, the case where the bending member 20 is a bowl-shaped member having a hemispherical curved surface 22 has been described as an example. However, the present invention is not limited to such a case. The bending member only needs to have at least a concave curved surface, and may have a part of a spherical surface (fragment or partial spherical surface) as the curved surface. Moreover, the case where it has a part (fragment) of the internal peripheral surface of a cylinder as a curved surface may be sufficient. In addition, in a form in which a part of the inner peripheral surface of the cylinder, for example, the inner peripheral surface of the semi-cylinder is used as the curved surface, the channel outlet having a shape extending in the axial direction of the semi-cylinder (for example, a rectangular shape elongated in the axial direction). A raw material powder channel having a channel outlet shape) may be used. Alternatively, the outlets of the plurality of raw material powder channels may be arranged in the axial direction of the semi-cylinder.

  In addition, instead of the case where the flow of the raw material powder spreading radially (three-dimensionally) is formed from the central portion of the curved surface, a case where a flow spreading two-dimensionally may be formed, It may be the case where the flow of the raw material powder is formed only from one position along the curved surface in one direction along the curved surface. That is, in the present invention, the flow direction of the raw material powder is continuously changed using the curved surface to obtain an action by continuous inertial impact (impactor), and the raw material powder along the curved surface is obtained. Various configurations can be employed to create a body flow. Further, in the case where a curved surface having a size exceeding the hemispherical surface is used, the distance at which an action by continuous inertial impact (impactor) can be obtained can be increased. At the same time, the turning angle of the fine powder flow at the classification position P can be made larger, and the effect of separation using inertial force can be enhanced.

  Moreover, about the shape of the 1st-3rd casing 11,12,13, it demonstrated as an example and can use various other shapes. For example, the tapered surface of the tapered cylinder 15 in the first casing 11 may be curved so that the inner surface side is a concave surface.

  Moreover, although the collision member 24 provided in the center part of the inner bottom of the bending member 20 has a substantially conical shape and the outer peripheral surface 24a is formed as a concave curved surface as an example, such a configuration is described. Not only limited. The collision member 24 plays a role of assisting the flow of the raw material powder supplied to the central portion of the inner bottom of the bending member 20 to flow along the curved surface 22, and can take various other shapes. Further, a configuration in which the collision member 24 is not provided and the flow of the raw material powder directly collides with the inner bottom center portion of the curved surface 22 to form a flow along the curved surface 22 may be adopted. good.

  Further, the bending member and the raw material powder introduction tube may be relatively rotated with the central axis of the bending member (or the raw material powder introduction tube) as the rotation center. The relative rotation in this way reduces the influence of variations with respect to the central axis, such as the angle and curvature of the curved surface of the bending member, and the deviation of the flow of the raw material powder supplied from the raw material powder introduction pipe with respect to the central axis. be able to. In particular, it is preferable to perform the relative rotation at a low speed so slowly that the relative rotation does not affect the flow of the raw material powder along the curved surface.

  In each of the above-described embodiments, the curved member is disposed with the curved surface facing downward on the upper side of the raw material powder introduction pipe (raw material powder flow path), the fine powder is on the upper side, and the coarse powder is on the lower side. However, the present invention is not limited to such a configuration. For example, a configuration in which the vertical direction is inverted may be employed. That is, a configuration may be adopted in which the curved member is disposed on the lower side of the raw material powder flow path with the curved surface facing upward, and the fine powder is divided on the lower side and the coarse powder is divided on the upper side. Further, the arrangement relationship of each member is not limited to the vertical direction, and may be configured to be arranged in other directions.

  It is to be noted that, by appropriately combining any of the above-described various embodiments, the effects possessed by them can be produced.

  While the invention has been fully described in connection with preferred embodiments with reference to the accompanying drawings, various changes and modifications will be apparent to those skilled in the art. Such changes and modifications are to be understood as being included therein, so long as they do not depart from the scope of the present invention according to the appended claims.

DESCRIPTION OF SYMBOLS 1 Powder classification system 2 Fixed quantity feeder 3 Dispersing machine 4 Powder classification apparatus 5 Bag filter for fine powder collection 6 Bag filter for coarse powder collection 7 Vacuum pump 8 Clean air supply part 11 1st casing 12 2nd casing 13 3rd casing 20 Curved member 22 Curved surface 24 Collision member 31 Raw material powder flow path 32 First powder flow path 34 Coarse powder flow path P Classification position S Classification processing space

Claims (11)

In a powder classification apparatus for classifying raw material powder supplied in a mixed state with gas into a first powder and a second powder,
A curved member having a bowl-shaped curved surface;
A casing enclosing the curved member in a state of forming an annular gap between the annular edge of the curved member,
A raw material powder flow path for supplying the raw material powder to the curved surface;
An annular first powder that is formed between the outer wall surface of the bending member and the inner wall surface of the casing, communicates with an annular gap between the edge of the bending member and the inner wall surface of the casing, and is applied with a suction force. A body flow path,
The casing is a cylindrical inclined wall that has an inclined surface that is inclined with respect to the axis of the bending member so as to face the curved surface of the bending member and that extends on the opposite side of the first powder flow path with respect to the annular gap. With
The raw material powder flow path has a raw material powder supply port arranged so as to face the inner bottom center portion of the curved surface of the bending member,
Classification processing space in which the space surrounded by the inclined surface of the casing and the inner space of the curved surface are integrated between the supply port of the raw material powder channel, the inclined wall of the casing, and the curved surface of the bending member Is placed,
By supplying the raw material powder from the supply port of the raw material powder channel to the inner bottom center portion of the curved surface, the raw material powder along the curved surface from the inner bottom center portion of the curved surface toward the annular edge while forming a flow, in an annular edge of the curved member, from the flow of the raw material powder along the curved surface, the first powder is sucked into the first powder passage, the second powder, The second powder flowing along the inclined surface is classified as a flow of the second powder flowing along the inclined surface by going outward from the annular end edge of the bending member in the direction along the curved surface of the cylindrical inclined wall . Part of the powder flow is attracted by the flow of the raw material powder from the supply port of the raw material powder channel through the central part of the classification treatment space and toward the central part of the inner bottom of the curved surface. with the body of the flow Ru is flow towards the inner bottom center portion of the curved surface is formed, the powder classifying device.   A plurality of clean air introduction flow paths are connected in the circumferential direction to the casing,
  When clean air is introduced from each clean air introduction flow path, a clean air swirl flow is formed along the inclined surface of the cylindrical inclined wall, and a clean air swirl flow is formed. The powder classification apparatus according to claim 1, wherein classification of the first powder and the second powder is performed. A guide member having a curved surface that guides the flow of the second powder toward the outside from the annular end edge of the curved member in a direction along the curved surface;
The powder classification apparatus according to claim 1 or 2 , wherein a classification processing space is defined by the bending member and the guide member. An ejector having a discharge port for discharging the raw material powder and an induction port for attracting a part of the flow of the second powder and joining the flow of the raw material powder using the flow of the raw material powder passing therethrough The powder classification apparatus according to any one of claims 1 to 3 , which is provided at a supply port of the raw material powder flow path. A second powder flow path connected to the cylindrical inclined wall and disposed to face the curved surface of the bending member;
At the annular edge of the bending member, the first powder is sucked into the first powder flow path and the second powder flows into the second powder flow path from the flow of the raw material powder along the curved surface. The powder classification apparatus according to any one of claims 1 to 4, wherein the powder classification device is classified into a flow of the first powder and a flow of the second powder so as to be directed toward the surface. Further comprising a collision member disposed in the inner bottom central portion of the curved surface of the curved member;
The raw material powder flow path supplies the raw material powder so as to form a flow of the raw material powder along the center of the inner surface of the curved surface and along the axis of the curved member,
The flow of the raw material powder along the curved surface that spreads from the central portion of the inner bottom of the curved surface to the annular edge when the flow of the raw material powder supplied from the raw material powder channel collides with the collision member. The powder classification device according to any one of claims 1 to 4 , wherein: is formed. The powder classifier according to claim 6 , wherein the collision member has a conical shape and is disposed at a central portion of the inner bottom of the curved surface such that the top portion faces the raw material powder flow path. The powder classification device according to claim 6 or 7 , wherein the outer surface of the collision member is formed as a curved surface continuous with the curved surface of the curved member. The powder classification apparatus according to any one of claims 1 to 8 , wherein a curved surface of the bending member has a hemispherical shape. The bending member includes a bowl-shaped curved surface to which the raw material powder is supplied from the raw material powder flow path, and an annular cylindrical inner peripheral surface extending from the end of the curved surface, and the edge of the cylindrical inner peripheral surface is curved. as the edge of the member, the second powder flow from the end edge of the curved members are classified as toward the inclined surface of the cylindrical inclined walls of the casing, in any one of claims 1 9 The powder classifier described. The first and second powder classifiers according to any one of claims 1 to 10 ,
A powder classification system comprising: a first powder channel of a first powder classifier; and a powder channel that connects a raw material powder channel of a second powder classifier.

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