Hopper and powder supply device

Abstract

This technology provides a way to suppress flushing that occurs when materials are introduced into a hopper. [Solution] A receiving section 11c for receiving powder, and below the receiving section 11c A hopper 10 is provided, which has a feeding section 11d located at the top for sending the powder to a feeder 80, and a powder contact section 12 located between the receiving section 11c and the feeding section 11d that strikes the powder as it falls, wherein the powder contact section 12 is a cylindrical member communicating vertically, and has a first member 30 whose inner surface decreases in diameter as it goes downwards and to which the powder strikes, and a second member 20 located between the first member 30 and the feeding section 11d, which has a first convex portion (conical body 21) that decreases in diameter as it goes upwards, and to which the powder that has passed through the first member 30 strikes the surface of the first convex portion (conical body 21), and a first flow path (flange opening 23) is provided around the bottom surface of the first convex portion (conical body 21) for dropping the powder toward the feeding section 11d.

Description

Technical Field

[0001] The present invention relates to a hopper and a powder supply device.

Background Art

[0002] Devices that store powder in a hopper and supply the powder to the next process with a feeder are known. When gas is contained in the powder supplied to the hopper from the upstream cut gate, the fluidity of the powder increases rapidly, and flushing may occur. Flushing refers to a phenomenon in which the fluidity of the powder increases rapidly due to the inclusion of gas in the powder, and it flows like a low-viscosity fluid with a slight differential pressure or driving force. When flushing occurs, it becomes difficult to stop the flow of the powder. Therefore, various techniques have been proposed to prevent flushing (see, for example, Patent Document 1). Patent Document 1 discloses a configuration including a conical baffle plate and a barrier member fixed by stays at the bottom of a vibrating feeder (vibrating powder and granule discharging device), and a flow control plate at the lower part. This is designed to prevent flushing even when the distance between the bottom surface of the barrier member and the discharge port is larger than before.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When supplying a powder having high flushing properties, such as silica, using a hopper, the powder flowing into the hopper from the cut gate may not stop at the feeder provided below the hopper. In this case, there is a possibility that the supply amount of the powder cannot be controlled.

[0005] This invention has been made in view of such circumstances, and aims to enable control over the supply amount of powder even when powder with high flushing properties is introduced into a hopper. [Means for solving the problem]

[0006] The present invention provides the following technologies. 1. A receiving section for receiving powder, A feeding section located below the receiving section for sending the powder to the feeder, It has a powder contact portion located between the receiving portion and the feeding portion, which comes into contact with the powder as it falls, The powder contact portion is, A cylindrical member that is connected vertically, the first member having an inner surface that narrows in diameter towards the bottom and the powder contacts the inner surface, A second member is located between the first member and the feeding section, and has a first convex portion that decreases in diameter as it goes upward, with the surface of the first convex portion in contact with the powder that has passed through the first member, It has, A hopper is provided with a first flow path around the bottom surface of the first protrusion for dropping the powder toward the feeding section. 2. The hopper according to 1, wherein the tip of the first protrusion is inserted into the lower opening of the first member without contacting the first member. 3. The powder contact portion is, A third member is further provided between the receiving portion and the first member, having a second protrusion that decreases in diameter as it goes upwards. The hopper according to 1. or 2., wherein a second flow path for dropping the powder toward the first member is provided around the bottom surface of the second protrusion. 4. When S1 is the area of ​​the gap between the first member and the second member at the same height as the lower opening of the first member, and S2 is the area of ​​the second flow path at the same height as the bottom surface of the second protrusion, S1 / S2 × 100 (%) = 10% or more and 20% or less. The hopper described in 3. 5. The hopper according to any one of 1 to 4, wherein, when viewed from below, the bottom surface of the first protrusion of the second member covers the lower opening of the first member. 6. The hopper according to any one of 1 to 5, further comprising a fourth member which is a straight pipe located above the powder contact portion. 7. A hopper as described in any one of items 1 through 6, A feeder that receives powder from the hopper and supplies the powder to the outside, A mass measuring device that measures the mass change of the hopper and the feeder, and measures the mass of the powder supplied from the feeder to the next process, A powder supply device having the following features. [Effects of the Invention]

[0007] According to the present invention, by employing a hopper as described above, it is possible to suppress flushing when material is introduced into the hopper and realize a powder supply device that can supply powder stably. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing the general configuration of a powder supply device according to the first embodiment. [Figure 2] This is a schematic diagram showing the general configuration of a hopper according to the first embodiment. [Figure 3] This is a schematic diagram showing the general configuration of the second member according to the first embodiment. [Figure 4] This is a schematic diagram showing the general configuration of the first member according to the first embodiment. [Figure 5] This is a schematic diagram showing the general configuration of a hopper according to the second embodiment. [Figure 6] This is a schematic diagram showing the general configuration of the third member according to the second embodiment.

Mode for Carrying Out the Invention

[0009] <<First Embodiment>> <Outline of Powder Feeding Device 1> FIG. 1 is a schematic diagram showing a schematic configuration of the internal structure of the powder feeding device 1 of the present embodiment. FIG. 2 is a schematic diagram showing a schematic configuration of the internal structure of the hopper 10 and the feeder 80, and is an enlarged view of the region A in FIG. 1. FIG. 3 is a view showing the second member 20, where FIG. 3(a) is a perspective view and FIG. 3(b) is a longitudinal sectional view. FIG. 4 is a view showing the first member 30, where FIG. 4(a) is a perspective view and FIG. 4(b) is a longitudinal sectional view. In the drawings, the flow of the powder P is indicated by arrows.

[0010] The powder feeding device 1 of the present embodiment includes a mass measuring device 90, a feeder 80, and a hopper 10. On the upper side of the hopper 10, an air-driven cut gate 72 is provided as an example. By opening and closing the air-driven cut gate 72, a predetermined amount of powder P falls from the upstream of the air-driven cut gate 72 into the hopper 10. Note that a soft cylindrical member 17 (for example, a polyester bag) connects the air-driven cut gate 72 and the receiving portion 11c of the hopper 10 (the opening 55 at the upper part of the straight pipe 50 in the present embodiment) so that the air-driven cut gate 72 and the mass upstream thereof do not act on the mass measuring device 90.

[0011] Powder is an aggregate of fine solid particles, and granule is an aggregate of relatively coarse solid particles. There is no clear distinction between powder and granule, but generally, those with a particle size of 1 mm or less are regarded as powder, and those larger than that are regarded as granules. Hereinafter, unless otherwise specified, powder and granule will be referred to as "powder" for convenience of explanation. Also, as an example, the size of the powder in the present embodiment is about 0.01 μm to 500 μm.

[0012] The feeder 80 supplies the powder P stored in the hopper 10 to the next process in a set, constant mass. Examples of feeders 80 include a table feeder and a disc feeder. A table feeder is a type of rotary feeding machine in which a disc or scraping blade attached to the bottom of a cylindrical hopper rotates to cut out the powder P. A disc feeder is a device in which a supply disc with circumferential grooves cut into its upper surface rotates in a constant direction, dropping and accumulating the powder P onto the supply disc at a predetermined position, scraping the accumulated powder P into the grooves of the supply disc with a scraping plate, and cutting out the powder P while rotating.

[0013] The mass measuring device 90 determines the mass of the powder supplied from the feeder 80 to the next process by measuring the mass changes of the hopper 10 and the feeder 80, and the feeder 80 uses feedback control based on the results.

[0014] In this embodiment, the hopper 10 has a configuration (first member 30 and second member 20) that prevents flushing of the introduced powder, so that the feedback control by the feeder 80 can be performed properly. This will be explained in detail below.

[0015] <Hopper 10> The hopper 10 receives powder P from the receiving section 11c at the top of the hopper, stores a certain weight of powder P, and sends the powder P to the feeder 80 from the feeding section 11d at the bottom of the hopper. In this embodiment, as an example, the receiving section 11c is the opening 55 at the top of the straight pipe 50. In addition, the second member 20 is attached to the upper surface of the feeder 80 via a connecting member 19 having a communication hole 18, and the bottom surface (flange portion 22) of the second member 20 becomes the feeding section 11d at the bottom of the hopper.

[0016] The hopper 10 comprises a hopper body 11, a powder contact section 12 provided inside the hopper body 11, and a straight pipe 50 (fourth member) provided above the powder contact section 12. Specifically, the powder contact section 12 is provided between the receiving section 11c and the feeding section 11d. The powder contact section 12 consists of a first member 30 and a second member 20 arranged from top to bottom. It is preferable that the centers of the hopper body 11, the first member 30, the second member 20, and the straight pipe 50 coincide when viewed from above.

[0017] The hopper body 11 is a cylindrical member with a straight pipe 50 provided at the opening at its top. The hopper body 11 is not limited to the shape shown and can take various shapes. The hopper body 11 may be composed of multiple members (upper hopper body 11a and lower hopper body 11b), as described below, or it may be composed of a single member. Also, the hopper body 11 as a whole may have the same inner diameter, or it may have different inner diameters depending on its position in the vertical direction. The powder P introduced from upstream by opening and closing the air-driven cut gate 72 is received from the receiving section 11c and supplied to the inside of the hopper body 11 via the straight pipe 50. Inside the hopper body 11, it is preferable that the first member 30 and the second member 20, which are the powder contact section 12, are arranged vertically so that their centers coincide when viewed from above. The powder P passes through the straight pipe 50, the first member 30, and the second member 20 inside the hopper body 11, then through the feeding section 11d, and is supplied to the feeder 80.

[0018] The hopper body 11 has an upper hopper body 11a on the upper side and a lower hopper body 11b on the lower side. The flange portion 32 of the first member 30 is attached between the upper hopper body 11a and the lower hopper body 11b so as to be sandwiched in between. The second member 20 is attached to the bottom surface of the lower hopper body 11b so as to have the ring portion 25 of its flange portion 22 sandwiched between the lower hopper body 11b and the connecting member 19 at the bottom of the hopper.

[0019] <Straight pipe 50 (4th member)> The fourth component, the straight pipe 50, includes, for example, a straight pipe body 51 and an air vent section 52. The straight pipe body 51 is, for example, a circular stainless steel pipe with a circular cross-section. The opening 55 at the top of the straight pipe 50 functions as a receiving section 11c. The diameter of the straight pipe body 51 is, for example, 100 mm or more and 300 mm or less. The diameter of the straight pipe body 51 is 30% to 85% of the diameter of the hopper body 11 at the lower opening 54 of the straight pipe body 51, preferably 50% to 65%, and more preferably 55% to 60%. By setting the diameter of the straight pipe body 51 relative to the diameter of the hopper body 11 as described above, it is possible to prevent the powder P from diffusing or scattering and entraining air in the hopper body 11 when the powder P is introduced into the hopper body 11.

[0020] <First component 30> The first member 30 is located above the second member 20. In other words, it is positioned between the straight pipe 50 and the second member 20. The first member 30 is located between the receiving section 11c and the feeding section 11d, and is a cylindrical member that communicates vertically, with its inner surface becoming smaller in diameter towards the bottom, and the powder P coming into contact with this inner surface. The first member 30 is made of stainless steel, for example.

[0021] The first member 30 has a funnel body 31 in the shape of a so-called funnel, and a flange portion 32 extending outward in an annular shape from the upper end of the funnel body 31. The funnel body 31 is the part where the inner surface is tapered in diameter towards the bottom and the powder P comes into contact with this inner surface. Specifically, the funnel body 31 is shaped like an inverted cone with its lower end cut off, and has an upper opening 34 and a lower opening 33. A flow path is formed between the upper opening 34 and the lower opening 33 through which the powder P passes. The shape of the funnel body 31 is not limited to a cone; it may be shaped like an inverted polygonal pyramid with its lower end cut off. When the funnel body 31 is described as tapering in diameter towards the bottom, it means that the size of the inner shape is reduced. In the case of a cone, this means that the inner diameter becomes smaller. In the case of a polygonal pyramid, it means that the maximum width of the cross-sectional shape becomes smaller, and the length of each side also becomes smaller.

[0022] The flange portion 32 is sandwiched between the upper hopper body 11a and the lower hopper body 11b, and the first member 30 is fixed to the hopper body 11.

[0023] The distance between the first component 30 (funnel body 31) and the straight pipe 50 is, for example, 0 mm to 900 mm. By setting the distance between the first component 30 and the straight pipe 50 within the above range, air entrainment into the powder P can be minimized and the powder can be fed into the first component 30.

[0024] In the funnel body 31, the powder P that enters and falls through the upper opening 34 hits the inner surface, is collected towards the center due to the inclination of the inner surface, moves downward (i.e., towards the second member 20) through the lower opening 33, and is discharged. The inclination angle θ1 of the inner surface of the funnel body 31 with respect to the horizontal plane is, for example, 35° to 70°, and preferably 40° to 50°. By setting the inclination angle θ1 within the above range, the powder P can move smoothly downwards without getting stuck along the way. From another perspective, the inclination angle θ1 is greater than the angle of repose of the powder P. The angle of repose is the angle between the slope of the pile of powder formed when powder is dropped from a certain height and remains stable without spontaneously collapsing, and the horizontal plane. There are various measurement methods for measuring the angle of repose of powder P, including injection methods using a funnel and a disc-shaped receiving tray, discharge methods, and inclination methods, but this embodiment is based on the injection method. The angle of repose can be measured using, for example, a powder property evaluation device (such as the Powder Tester PT-X (manufactured by Hosokawa Micron Corporation) or the Multi Tester MT-1 (manufactured by Seishin Corporation)).

[0025] The inner diameter of the upper opening 34 is approximately the same as the inner diameter of the hopper body 11 at the point where the funnel body 31 is attached (the inner diameter of the lower part of the upper hopper body 11a and the inner diameter of the upper part of the lower hopper body 11b). When the inner diameter of the upper opening 34 is R31 and the inner diameter of the lower opening 33 is R32, the ratio R32 / R31 is, for example, 0.3 to 0.5. By setting the ratio R32 / R31 within the above range, the powder P can be collected in a certain area in the center of the hopper body 11, and the entrapment of air contained in the powder P can be reduced.

[0026] In this embodiment, the horizontal cross-section of the funnel body 31 is circular, but this is not the only option. For example, the cross-section may be polygonal or a shape combining straight and curved lines. In any case, a configuration is adopted that allows the powder P to move smoothly downwards.

[0027] <Second component 20> The second member 20 is located between the first member 30 and the feed section 11d. The second member 20 has a conical body 21, which is a first convex portion that decreases in diameter towards the top, and a flange portion 22. The powder P that has passed through the first member 30 strikes the surface of the conical body 21.

[0028] The conical body 21 is, for example, a cone. The conical body 21 may also be a polygonal pyramid, but considering the smooth movement of the powder P, a polygonal pyramid with a cross-section close to a circle (for example, octagonal or more) is preferred. The fact that the diameter of the conical body 21 decreases towards the top means that the outer shape of the conical body 21 decreases, and in the case of a cone, it means that the outer diameter becomes smaller. In the case of a polygon, it means that the maximum width of the cross-sectional shape becomes smaller, and the length of each side also decreases accordingly.

[0029] The conical body 21 does not have an opening. Therefore, the powder P cannot move directly below the conical body 21. Furthermore, the conical body 21 does not have a concave shape that would allow the powder P to remain.

[0030] The tip of the cone-shaped body 21 extends into the interior of the first member 30 through the lower opening 33 of the first member 30. At this time, the cone-shaped body 21 is not in contact with the first member 30 (more specifically, the funnel body 31). In other words, the lower opening 33 of the funnel body 31 is not closed by the second member 20, and the flow path for the powder P is ensured.

[0031] Furthermore, when viewed from below, the bottom surface of the conical body 21 (first protrusion) of the second member 20 covers the lower opening (lower opening 33) of the first member 30. In other words, the inner diameter of the lower opening 33 is smaller than the outer diameter of the bottom surface of the conical body 21 of the second member 20. With this configuration, powder P moving downward from the lower opening 33 does not fall directly into the flange opening 23 of the flange portion 22. This ensures that the conical body 21 can reliably perform its function as a baffle plate.

[0032] A first flow path is provided around the bottom surface of the cone-shaped body 21 for dropping the powder P towards the feeding section 11d.

[0033] Specifically, the bottom surface of the conical body 21 is provided with an annular flange portion 22 that extends outward. The flange portion 22 has an outermost ring portion 25 and a flange bridge portion 24 that connects the ring portion 25 and the cone portion body 21. For example, the flange bridge portion 24 is provided in a shape that connects to the cone portion body 21 at four points. The opening demarcated by the ring portion 25, the flange bridge portion 24 and the bottom surface of the cone portion body 21 is the flange opening 23. The flange opening 23 is connected to a feeder 80, and powder P is supplied to the feeder 80 by passing through the flange opening 23. In other words, the flange opening 23 functions as the first flow path.

[0034] The angle of inclination θ2 of the side surface 27 of the cone body 21 with respect to the horizontal plane is greater than the angle of repose of the powder P. The angle of inclination θ2 is, for example, 45° to 70°, and preferably 50° to 65°. The angle of repose of the powder P is 10° to 55° when the average particle size is 0.01 μm to 50 μm. If the angle of inclination θ2 is not constant, the angle of inclination θ2 is greater than the angle of repose of the powder P at any position and falls within the above range.

[0035] By making the inclination angle θ2 larger than the angle of repose of the powder P, the powder P is reliably moved downward without remaining on the side surface 27 of the cone body 21.

[0036] Examples of powder P include silica, crystalline zeolite, and calcium oxide. The average particle size of powder P is, for example, between 0.01 μm and 50 μm. The jet index of powder P is between 60 and 100. The jet index is an index proposed by RLCarr to quantitatively express the likelihood of a powder P flushing. The jet index is calculated as the sum of indices obtained from an empirically derived conversion table to measured values ​​of the flowability index, collapse angle, difference angle, and dispersion. The jet index (flowability index, collapse angle, difference angle, and dispersion) can be measured using, for example, a powder characterization device (such as the Powder Tester PT-X (manufactured by Hosokawa Micron Corporation) or the Multi Tester MT-1 (manufactured by Seishin Corporation)). The fluidity index is an evaluation index used to comprehensively and quantitatively represent the fluidity of a powder. It measures four values ​​of the powder: (1) angle of repose, (2) compressibility, (3) spatula angle, and (4) uniformity or cohesiveness. For each of these values, up to 25 indices, which have been empirically determined for many powders, are assigned points, and the index is expressed as the sum of these points. The collapse angle is the angle of inclination of the collapse surface formed by collapsing the powder deposit layer after measuring the angle of repose, by applying a certain impact force to a rectangular bat on which the measuring base is placed, using methods such as dropping a weight or an electromagnetic impactor. The difference angle is the difference between the angle of repose and the angle of collapse. Dispersion is a numerical representation of the property of powder particles in the gas phase to remain individually dispersed. Various evaluation methods exist depending on the purpose, including (1) expressing it as the flow velocity required to disperse the deposited powder particles in an airflow, and (2) expressing it as the percentage of particles that disperse when placed in an airflow of constant velocity. Powders with high dispersion generally have high dispersibility.

[0037] <Movement of powder P> The movement of powder P in the hopper 10 with the above configuration will be explained with reference to Figures 1 and 2. When the air-driven cut gate 72 opens and the powder P is fed into the hopper 10, it is fed from the straight pipe 50 into the hopper body 11. First, it passes through the upper opening 34 of the first member 30, and a portion of it hits the inclined surface of the funnel body 31 and changes direction toward the center. The remaining portion of the powder P hits the cone-shaped body 21 inserted into the first member 30 from the lower opening 33 and changes direction toward the outside. In this way, the powder P moves downward in the area between the upper opening 34 of the first member 30 and the cone-shaped body 21 at that position.

[0038] Furthermore, the powder P moves downward along the inclined surface of the cone body 21 and is fed into the feeder 80 through the flange opening 23 provided in the flange portion 22 of the second member 20. The powder P is then sent to the outside by the scraping blades 81 of the feeder 80.

[0039] In this way, the second member 20 and the first member 30 function as baffles, ensuring sufficient time for the powder P to fall. Furthermore, the area of ​​the powder passage, consisting of the reduced-diameter lower opening 33 of the first member 30 and the conical body 21 of the second member 20, becomes smaller relative to the area of ​​the upper opening 34 of the first member 30, thereby reducing the amount of air contained in the powder P. As a result, the occurrence of flushing can be suppressed. In addition, the powder supply device 1, which has a hopper 10 with a powder contact section 12 (first member 30 and second member 20), a feeder 80, and a mass measuring device 90, can suppress fluctuations in mass measurement associated with the stable fall of the powder P.

[0040] <<Second Embodiment>> The hopper 10 of the second embodiment will be described with reference to Figures 5 and 6. The description will focus on the parts that differ from the first embodiment, and similar components will be denoted by the same reference numerals and their descriptions will be omitted as appropriate. Figure 5 is a schematic diagram showing the general configuration of the hopper 10. Figure 6 is a diagram showing the configuration of the third member 40, where Figure 6(a) is a perspective view and Figure 6(b) is a longitudinal cross-sectional view.

[0041] In this embodiment, the difference from the first embodiment is that, in addition to the configuration of the first embodiment, a third member 40 is added as a powder contact portion 12, in addition to the first member 30 and the second member 20. The third member 40 is provided above the first member 30. That is, the third member 40 can be said to be provided between the straight pipe 50 and the first member 30. It is preferable that the centers of the third member 40 and the first member 30 coincide when viewed from above. The third member 40, not the first member 30, is positioned directly below the straight pipe 50.

[0042] The third member 40 has the same shape as the second member 20. Specifically, the third member 40 has a conical body 41 and a flange portion 42. The conical body 41 is a second convex portion that decreases in diameter towards the top, and is a cone or a polygonal pyramid, for example. The conical body 41 may have the exact same structure as the conical body 21 of the second member 20, or it may be a smaller size or have a different inclination. However, the conical body 41 of the third member 40 also decreases in diameter towards the top, similar to the conical body 21 of the second member 20, and the inclination angle θ3 of the side surface 47 of the conical body 41 with respect to the horizontal plane is greater than the angle of repose of the powder P. The inclination angle θ3 is, for example, 45° or more and 70° or less, and preferably 50° or more and 65° or less.

[0043] The distance from the lower end 53 (opening 54) of the straight pipe 50 to the tip of the cone body 41 is, for example, between -100 mm and +200 mm. When the distance is negative, it indicates that the tip of the cone body 41 has entered the lower end 53 (opening 54) of the straight pipe 50. However, even when the distance is negative, the cone body 41 and the straight pipe 50 are not in contact. Figure 5 shows a state where the distance is positive and the tip of the cone body 41 has not entered the lower end 53 (opening 54) of the straight pipe 50. Also, when the distance is negative, that is, when the tip of the cone body 41 has entered the lower end 53 (opening 54) of the straight pipe 50, the lower end 53 (opening 54) of the straight pipe 50 becomes narrower and the falling velocity of the powder P decreases. To ensure sufficient space for the powder P to pass through and to prevent the falling speed from decreasing too much, the ratio SB / SA of the area SA of the opening 54 to the cross-sectional area SB of the conical body 41 at the position of the opening 54 is preferably 0.5 or less, and more preferably 0.4 or less. Furthermore, from the viewpoint of ensuring that the powder P always hits the conical body 41 and preventing air from being drawn into the hopper 10 due to the diffusion and scattering of the powder P, the diameter of the bottom surface of the conical body 41 is preferably the same as or larger than the diameter of the lower end 53 (opening 54).

[0044] A second flow path is provided around the bottom surface of the conical body 41 for dropping the powder P toward the first member 30. Specifically, the bottom surface of the conical body 41 is provided with an annular flange portion 42 extending outward. The flange portion 42, like the flange portion 22 of the second member 20, has an outermost ring portion 45 and a flange bridge portion 44 connecting the ring portion 45 and the conical body 41. As an example, the flange bridge portion 44 is provided in a shape that is connected to the conical body 41 at four points. The opening demarcated by the ring portion 45, the flange bridge portion 44 and the bottom surface of the conical body 41 is the flange opening 43. The powder P moves through the flange opening 43 to the funnel body 31 of the first member 30. In other words, the flange opening 43 functions as the second flow path. Furthermore, the ring portion 45, together with the flange portion 32 of the first member 30, is sandwiched between the upper hopper body 11a and the lower hopper body 11b, thereby fixing the first member 30 and the third member 40 to the hopper body 11.

[0045] The second member 20, the first member 30, and the third member 40 have, as an example, the following relationship with respect to the flow path through which the powder P moves. When S1 is the area of ​​the gap between the first member 30 and the second member 20 at the same height as the lower opening (lower opening 33) of the first member 30, and S2 is the area of ​​the second flow path (i.e., flange opening 43) at the same height as the bottom surface of the second protrusion (conical body 41) of the third member, S1 / S2 = 10% or more and 20% or less.

[0046] Area S1 can also be described as the area of ​​the lower opening 33 of the first member 30 minus the cross-sectional area of ​​the conical body 21 of the second member 20 at that location. Area S2 can also be described as the sum of the areas of the flange openings 43.

[0047] The lower limit of S1 / S2 is preferably 12% or more, and more preferably 14% or more. The upper limit of S1 / S2 is preferably 18% or less, and more preferably 16% or less. By setting S1 / S2 to this numerical range, the flow path of powder P at the lower opening 33 of the first member 30 (i.e., the range in which powder P exists) can be made smaller than the flow path of powder P at the bottom surface of the third member 40 (i.e., the range in which powder P exists). As a result, powder P can be concentrated towards the bottom. In addition, since the third member 40 functions as a baffle plate, sufficient time can be secured for the powder P to accumulate, and the reduced flow path further reduces the amount of air contained in the powder P.

[0048] As described above, according to this embodiment, the first member 30, the second member 20, and the third member 40 function as baffles, ensuring sufficient time for the powder P to fall and reducing the amount of air contained in the powder P. As a result, the occurrence of flushing can be suppressed. The powder supply device 1, which has a hopper 10 having a powder contact portion 12 (first member 30, second member 20, and third member 40), a feeder 80, and a mass measuring device 90, can suppress fluctuations in mass measurement associated with the stable fall of the powder P.

[0049] <Summary of features and functions of Hopper 10 and Powder Feeding Device 1> The features of the hopper 10 and powder supply device 1 in the first and second embodiments will be briefly summarized below. 1. A receiving section 11c for receiving powder P, A feeding section 11d is located below the receiving section 11c and sends the powder P to the feeder 80, It has a powder contact portion 12 located between the receiving portion 11c and the feeding portion 11d, which the powder P strikes as it falls, The powder contact portion 12 is A cylindrical member that is connected vertically, the first member 30 having an inner surface that decreases in diameter as it goes downwards and the powder P comes into contact with the inner surface, A second member 20 is located between the first member 30 and the feeding section 11d, and has a first convex portion (conical body 21) that decreases in diameter as it goes upward, and the powder P that has passed through the first member 30 comes into contact with the surface of the first convex portion (conical body 21), It has, A hopper 10 is provided with a first flow path (flange opening 23) around the bottom surface of the first protrusion (conical body 21) for dropping the powder P toward the feeding section 11d. 2. The hopper 10 as described in 1, wherein the tip of the first protrusion (conical body 21) is inserted into the lower opening (lower opening 33) of the first member 30 without contacting the first member 30. 3. The powder contact portion 12 is Between the receiving portion 11c and the first member 30, there is further a third member 40 having a second convex portion (conical body 41) that decreases in diameter as it goes upward, The hopper 10 according to 1. or 2., wherein a second flow path (flange opening 43) for dropping the powder P toward the first member 30 is provided around the bottom surface of the second protrusion (conical body 41). 4. When S1 is the area of ​​the gap between the first member 30 and the second member 20 at the same height as the lower opening (lower opening 33) of the first member 30, and S2 is the area of ​​the second flow path (flange opening 43) at the same height as the bottom surface of the second protrusion (conical body 41), Hopper 10 as described in 3., where S1 / S2 × 100 (%) = 10% or more and 20% or less. 5. The hopper 10 according to 1. or 2., wherein, when viewed from below, the bottom surface of the first protrusion (conical body 21) of the second member 20 covers the lower opening (lower opening 33) of the first member 30. 6. The hopper 10 further has a fourth member (straight pipe 50) which is a straight pipe located above the powder contact portion 12. The hopper according to 1. or 2., wherein the fourth member (straight pipe 50) has its center coincide with that of the first member 30 when viewed from above. 7. Hopper 10 as described in 1. or 2., The hopper 10 receives the powder P, and the feeder 80 supplies the powder P to the outside. A mass measuring device 90 measures the mass change of the hopper 10 and the feeder 80, and measures the mass of the powder P supplied from the feeder 80 to the next process. A powder supply device 1 having the following features.

[0050] The embodiments of the present invention have been described above, but these are merely examples, and various other configurations can also be adopted. [Explanation of Symbols]

[0051] 1 Powder feeding device 10 hoppers 11 Hopper body 11c Receiving section 11d Feed section 12 Powder contact area 20 Second Member 21. Main body of the cone 22 Flange section 23 Flange opening 24 Flange bridge section 30 First Member 31 Funnel body 32 Flange section 33 Lower opening 34 Upper opening 40 Third Member 41. Main body of the cone 42 Flange section 43 Flange opening 50 straight pipe 80 Feeder 90 Mass measuring device

Claims

1. A receiving section for receiving powder, A feeding section located below the receiving section for sending the powder to the feeder, It has a powder contact portion located between the receiving portion and the feeding portion, which comes into contact with the powder as it falls, The powder contact portion is, A cylindrical member that is connected vertically, the first member having an inner surface that narrows in diameter towards the bottom and the powder contacts the inner surface, A second member is located between the first member and the feeding section, and has a first convex portion that decreases in diameter as it goes upward, with the powder that has passed through the first member striking the surface of the first convex portion. It has, A hopper is provided with a first flow path around the bottom surface of the first protrusion for dropping the powder toward the feeding section.

2. The hopper according to claim 1, wherein the tip of the first protrusion is inserted into the lower opening of the first member without contacting the first member.

3. The powder contact portion is, A third member is further provided between the receiving portion and the first member, having a second protrusion that decreases in diameter as it goes upwards. The hopper according to claim 1 or 2, wherein a second flow path for dropping the powder toward the first member is provided around the bottom surface of the second protrusion.

4. When S1 is the area of ​​the gap between the first member and the second member at the same height as the lower opening of the first member, and S2 is the area of ​​the second flow path at the same height as the bottom surface of the second protrusion, S1 / S2 × 100 (%) = 10% or more and 20% or less. The hopper according to claim 3.

5. The hopper according to claim 1 or 2, wherein, when viewed from below, the bottom surface of the first protrusion of the second member covers the lower opening of the first member.

6. The hopper according to claim 1 or 2, further comprising a fourth member which is a straight pipe located above the powder contact portion.

7. A hopper according to claim 1 or 2, A feeder that receives powder from the hopper and supplies the powder to the outside, A mass measuring device that measures the mass change of the hopper and the feeder, and measures the mass of the powder supplied from the feeder to the next process, A powder supply device having the following features.

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