Powder supply hopper

Abstract

To provide a convenient feeding hopper by making a microporous layer hard to wear and easy to clean.SOLUTION: A powder feeding hopper includes a conical inner wall 3 for directly storing powder and a conical outer wall 5 surrounding the whole circumference of the conical inner wall 3, and an air filling chamber 9 for filling compressed air supplied through an air supply hole is formed between the conical inner wall 3 and the conical outer wall 5, and at least a part of the conical inner wall 3 is constituted of a microporous material for performing aeration to the powder P in the conical inner wall 3 by permeating compressed air supplied to the air filling chamber 9, the microporous material is composed of metal and has a plurality of through-holes penetrating in a layer thickness direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a hopper for storing and supplying powder, and more specifically, to a powder supply hopper (hereinafter simply referred to as a "supply hopper") that enables aeration to fluidize the stored powder. [Background technology]

[0002] Examples of supply hoppers include those described in Patent Document 1 and Patent Document 2. The aeration means of Patent Document 1 (hereinafter referred to as the "first prior art means") uses a microporous layer made of high-density resin, more specifically, polyethylene. The aeration means of Patent Document 2 (hereinafter referred to as the "second prior art means") also uses a microporous layer made of resin, similar to the above. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-261163 A [Patent Document 2] JP 2002-68369 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the resin microporous layer of the first prior art and the second prior art has room for improvement in terms of clogging with powder due to wear and enlargement of pores, and deterioration of the washability of the layer itself.

[0005] Therefore, one object of the present disclosure is to provide a supply hopper that is easy to use by making the microporous layer less susceptible to wear and easier to clean. [Means for solving the problem]

[0006] Books A powder supply hopper according to one embodiment of the present disclosure includes: a conical inner wall that directly contains the powder; a conical outer wall surrounding the entire circumference of the conical inner wall; Equipped with The space between the inner and outer conical walls is filled with compressed air supplied through an air supply hole. An air-filled chamber is formed to fill the At least a portion of the conical inner wall is permeable to the compressed air supplied to the air filled chamber. The cone is made of a microporous material for aerating the powder inside the cone. And, The microporous material is made of metal and has a plurality of through holes penetrating in the layer thickness direction. Have It is , The microporous material has a first surface that contacts the air-filled chamber and a second surface that does not contact the air-filled chamber. and a second surface of Each of the plurality of through holes has a hole diameter at the first surface that is larger than a hole diameter at the second surface. is set large, Powder supply hopper 。 Effect of the Invention

[0007] According to the above configuration, the microporous layer used in the supply hopper is resistant to wear and easy to clean, so that a user-friendly supply hopper can be provided. [Brief description of the drawings]

[0008] [Figure 1] FIG. [Diagram 2] FIG. 2 is an exploded perspective view of the hopper shown in FIG. [Diagram 3] 2 is a partially cut-away enlarged view of the conical inner wall 3b shown in FIG. [Figure 4] FIG. 2 is an enlarged cross-sectional view of a microporous material (laminated microporous layers). [Diagram 5] 1 is a flowchart showing a manufacturing process of a conical inner wall (hopper). [Figure 6]FIG. 2 is a diagram showing the manufacturing process of the conical inner wall (hopper). [Figure 7] FIG. 2 is a perspective view showing the structure and installation method of a working electrode. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention (hereinafter, appropriately referred to as "the present embodiment") will be described with reference to the drawings.

[0010] (General structure of the hopper) The main components of the supply hopper 1 shown in Figs. 1 and 2 are a conical inner wall 3 that directly accommodates the powder P, a conical outer wall 5 that surrounds the entire circumference of the conical inner wall 3, an upper hopper (upper flange) 7 that is disposed above the conical inner wall 3 and the conical outer wall 5 and is used as an inlet for the powder P, and an annular packing (gasket) 8 that is disposed between the conical inner wall 3 and the conical outer wall 5 and the upper hopper 7 and seals the gap therebetween. The conical inner wall 3 and the conical outer wall 5 and the upper hopper 7 are fixed by a fixing means such as a clamp (not shown). The conical inner wall 3 and the conical outer wall 5 are configured as a double structure as shown in Fig. 2. The supply hopper 1 is supported from below by a base 11 as shown in the figure, for example, so that the opening of the upper hopper 7 faces upward. The shape of the base 11 may be appropriately selected depending on the type of powder to be stored and supplied, the supply form, the condition of the supply destination, and the like. Examples of the powder P directly accommodated in the conical inner wall 3 include food powders such as wheat flour, various chemical powders, pharmaceutical powders, cosmetic powders such as makeup powder, and mixed powders of these. As long as it matches the application, there is no restriction on the particle size of the powder, and what is generally called granular material may be included as a type of powder in this embodiment. If necessary, a vibration device (not shown) can be provided on the base 11 to vibrate the supply hopper 1 and assisted in preventing bridging of the powder P. The supply hopper 1 may also be fixed so as to be suspended from a tank or the like arranged above.

[0011] (Conical outer wall structure) For convenience of explanation, the conical outer wall 5 will be described first. As shown in FIG. 1 and FIG. 2, the conical outer wall 5 has a horizontal ring-shaped flange 5a with a desired radius, a conical wall 5b with an open top and tapered toward the base 11 below over a desired length to the bottom 5c, and a cylindrical portion 5d with a desired radius that protrudes downward from the approximate center of the bottom 5c and communicates with the inside and outside of the conical wall 5b. Each part constituting the conical outer wall 5 can be formed, for example, by laser cutting, bending, and welding of a stainless steel plate or the like. The conical outer wall 5 may be formed of a metal plate other than a stainless steel plate or a synthetic resin. As a preferred example, the flange 5a has an annular recess 5aa that is thinner by a predetermined dimension (approximately the same dimension as the thickness of the flange 3a described later) via a step on the center side. The air supply nozzle 6 is used to supply compressed air A received from a compressed air supply device 101 to an air-filled chamber 9 described later.

[0012] (Structure of the inner wall of the cone) The conical inner wall 3 has a horizontal ring-shaped flange 3a, a conical wall 3b that is open at the top and tapers downward, and a cylindrical portion 3c that protrudes downward from the lower end of the conical wall 3b and communicates the inside and outside of the conical inner wall 3. The cylindrical inner wall 3 is formed in a shape that allows the entire wall to be inserted completely into the conical outer wall 5. When inserted, the conical inner wall 3 fits inside the conical outer wall 5, and the flange 3a fits into the annular recess 5aa of the flange 5a with little play. The flange 3a fits into the annular recess 5aa with little play and the cylindrical portion 3c is inserted into the cylindrical portion 5d, so that the conical inner wall 3 is stably installed inside the conical outer wall 5. If you want to reinforce this installation just to be sure, you can reinforcing and fix the flange 3a that fits into the annular recess 5aa to the flange 5a with a fixing member such as a screw (not shown).

[0013] (Material of the inner wall of the cone) The entire conical inner wall 3, except for the welded portion (described later), is made of a microporous material. The microporous material allows compressed air A supplied to the air-filled chamber 9, which is a space defined between the conical inner wall 3 and the conical outer wall 5 and is kept airtight by a packing 8 and an O-ring 10, to pass through under pressure (FIG. 3, the dashed arrow indicates passage), and the compressed air A eventually passes through the powder P in the conical inner wall 3, fluidizing it, thereby making it possible to prevent bridging of the powder P. The microporous material of this embodiment is not a synthetic resin such as polyethylene, but a laminate of several to 20 layers of metallic microporous layers (thin metal plates). The metallic microporous layer is adopted because it can eliminate problems such as wear and the generation of foreign matter that occur when a polyethylene inner wall is used.

[0014] In each microporous layer, as a preferred embodiment, micropores with a pore diameter of about 50 μm to 200 μm are formed penetrating in the thickness direction at intervals of, for example, about 1 mm to 10 mm depending on the pore diameter. Each of the microporous layers used in this embodiment has a thickness of, for example, about 25 μm to 100 μm, and is laminated in 13 layers while adjusting the pore diameter and pore position for the entire penetration for compressed air A. More specifically, an example of a microporous material is composed of three microporous layers with a thickness of 25 μm and ten microporous layers with a thickness of 100 μm superimposed on each other. In general, when providing micropores in each microporous layer, it is desirable to reduce the thickness of the microporous layer in order to reduce the pore diameter of the micropores. On the other hand, in order to form the conical inner wall 3, a certain plate thickness is required from the viewpoint of necessary mechanical strength and processability. For this reason, in this embodiment, the conical inner wall 3 is formed using a microporous material in which multiple microporous layers are superimposed.

[0015] A preferred example of the pore size of each micropore of the microporous layer will be described. As shown in FIG. 4, for example, the pore size of the through hole 3h1 of the microporous layer 3m1 closest to the powder P can be set to the smallest 70 μm, and the pore size of the through hole 3hn of the microporous layer 3mn (the 13th in this embodiment) farthest from the powder P can be set to the largest 200 μm. In addition, the pore sizes are set smaller or the same in the order of the adjacent holes from the microporous layer 3mn to the microporous layer 3m1. That is, the pore size of the through hole 3mh of the microporous layer 3m3 is set smaller than the pore size of the through hole 3mh of the microporous layer 3m4, and the pore size of the through hole 3mh of the microporous layer 3m3 is set to the same as the pore size of the through hole 3mh of the microporous layer 3m2.

[0016] In other words, the microporous material is configured so that the pore size of the micropores in the microporous layer arranged on the inside of the conical inner wall 3 (the side where the powder P is stored), i.e., the surface (second surface) that is not in contact with the air-filled chamber 9, is relatively small, and the pore size of the micropores in the microporous layer on the outside of the conical inner wall 3, i.e., the surface (first surface) that is in contact with the air-filled chamber 9, is relatively large. Between the micropores in the innermost microporous layer and the micropores in the outermost microporous layer in the conical inner wall 3, the pore size may be narrowed stepwise as illustrated in Fig. 4, or the pore size may be narrowed continuously. The pore size may be approximately constant between the first surface and the second surface.

[0017] The reason why the diameters of the micropores are set as described above is that the diameter of the through hole 3h1 closest to the powder P needs to be smaller than the particle size of the powder P, while the diameter of the farthest through hole 3hn is preferably larger to facilitate injection of the compressed air A. Note that combinations other than those described above may be used as long as they do not impede the flow of the compressed air A.

[0018] (Method of manufacturing the inner wall of the cone) A method for manufacturing the conical inner wall will be described with reference to Figs. 5 and 6. First, a sector-shaped ring piece 53 is prepared. For example, a number of fine through holes are formed by photoetching a thin metal plate of an appropriate thickness in a range corresponding to the sector-shaped ring piece 53, and a predetermined number of sheets (13 sheets in this embodiment) are stacked while aligning the through holes of each thin metal plate, and the thin plates are bonded to each other using a diffusion bonding technique to obtain a microporous material 51. Then, as shown in Fig. 6(a), a sector-shaped ring piece 53 is cut out from the microporous material 51 (step S1). The sector-shaped ring is a shape obtained by removing a sector with a small radius from a sector, and is a part that forms the conical inner wall 3. For example, the cutting out is performed by pressing for efficiency. Next, the sector-shaped ring piece 53 is rolled, for example, by a roll press, and the end 53a and the end 53b are butted against each other (step S3).

[0019] 6(b), end 53a and end 53b are butted against each other and welded to be fixed to each other (step S5), and flange 3a and cylindrical portion 3c, which were separately manufactured on conical inner wall 3, are welded to the upper and lower parts of conical inner wall 3, respectively (step S7). If there are any other necessary parts in addition to those mentioned above, they may be welded to conical inner wall 3 in this process.

[0020] At this stage, the general shape of the conical inner wall 3 is formed. For this reason, hereinafter, the component numbers of the sectorial ring piece 53 and the conical inner wall 3 are written together, such as "53(3)". Note that the welded area is a part that cannot be aerated due to metal melting, but it is small in area compared to the entire sectorial ring piece 53 (i.e., the conical inner wall 3), and is sufficiently covered by the compressed air A sprayed around it. For this reason, the entire conical inner wall 3 can be considered to be substantially made of a microporous material.

[0021] Next, as shown in FIG. 6(c), the inner wall of the cone inner wall 3 is electrolytically polished (step S9). Here, the working electrode 105 is placed in the cone inner wall 3 so as to face the inner wall of the cone inner wall 3 after the flange 3a and the cylindrical portion 3c have been welded and fixed, and the cone inner wall 3 and the working electrode 105 are immersed in the electrolytic polishing solution R. Then, when a direct current is applied with the cone inner wall 3 as the positive side and the working electrode 105 as the negative side, the part facing the working electrode 105 is dissolved to obtain a polishing effect. In other words, a polished surface of the inner wall of the cone inner wall 3 is obtained, and the smoothness of the exposed surface is improved. This improves the sliding of the contained powder P toward the cylindrical portion 3c. In other words, the effect of aeration is supplementarily enhanced to effectively prevent bridging of the powder P. Improving the slipperiness also reduces the load caused by collision and sliding with the powder P, which has the effect of making the inner wall (exposed surface) of the conical inner wall 3 less susceptible to wear. The geometric features of the working electrode 105 will be described later.

[0022] At the end of the manufacturing process, the conical inner wall 3 (together with the fixed flange 3a and cylindrical portion 3c) is removed from the electrolytic polishing solution R. This removal process includes, if necessary, a process of washing the removed conical inner wall 3 with a washing solution and then drying it (step S11). This completes the manufacture of the conical inner wall 3 (supply hopper 1).

[0023] (Working electrode shape) The configuration of the working electrode 105 used in the electrolytic polishing will be described with reference to Fig. 7. The working electrode 105 used in the polishing step is preferably a truncated cone electrode having an electrode surface disposed at a substantially fixed distance from the conical inner wall 3 as shown in the figure. Such a working electrode 105 can be formed, for example, from a metal plate such as a copper plate or a stainless steel plate through steps that are the same as or similar to the cutting step, rounding step, and forming step in the manufacture of the conical inner wall 3.

[0024] The truncated cone electrode 105 is arranged so that its center line substantially coincides with the center line Lc of the conical inner wall 3 shown in Fig. 7 (i.e., arranged concentrically). The truncated cone electrode 105 is arranged so that the distance D between its outer wall and the inner wall of the conical inner wall 3 is substantially constant in the circumferential direction (including an error due to play). Moreover, it is preferable that the generatrix Lt of the truncated cone electrode 105 is set to be equal to or longer than the generatrix Lw of the conical inner wall 3.

[0025] First, by making the distance D approximately constant in the circumferential direction, the working electrode 105 and the inner wall of the cone inner wall 3 face each other at approximately the same distance (under the same conditions) at any point on the inner wall of the cone inner wall 3. As a result, the entire surface of the inner wall of the cone inner wall 3 is polished more uniformly, and the smoothness is increased compared to a non-uniform surface. In addition, by setting the generatrix Lt to be the same as or longer than the generatrix Lw of the cone inner wall 3, the entire inner wall of the cone inner wall 3 can be opposed to the working electrode 105 without any omissions, and the entire inner wall can be polished without any omissions.

[0026] According to the above embodiment, the microporous layer is less susceptible to wear and easier to clean, making it possible to provide a supply hopper that is easy to use. In detail, if the inner wall of the cone is made of high-density polyethylene resin or the like, there is a concern that foreign matter may be mixed in due to wear, and the cleaning properties are also poor. Furthermore, if the inner wall of the cone is made of sintered wire mesh or the like, it is often unclear whether the powder that has entered the mesh of the wire mesh has been cleaned reliably. In response to these problems, in this embodiment, the inner wall of the cone is made of a microporous material, which can solve the above-mentioned inconveniences.

[0027] Furthermore, when electrolytic polishing is performed on the inner wall of the cone using a truncated cone electrode, the surface (exposed surface) of the inner wall of the cone is polished uniformly and smoothly over the entire surface, which makes it easier for the contained powder to slide toward the cylindrical section, thereby supplementing or enhancing the effect of aeration in a synergistic manner. As a result, powder bridges and the like can be effectively broken down, and clogging of the through holes caused by wear on the inner wall of the cone can be effectively prevented. In addition, cleaning is also easy. In other words, a supply hopper that is easy to use can be provided.

[0028] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. For example, the electrolytic polishing step may be omitted from the above-described manufacturing process depending on the application of the supply hopper 1. In addition, although the conical inner wall 3 is formed using a microporous material having multiple microporous layers in the above-described embodiment, the conical inner wall 3 may be formed using a single-layer microporous material as long as the mechanical strength and processability according to the application can be obtained. [Explanation of symbols]

[0029] 1: supply hopper, 3: conical inner wall, 3a: flange, 3b: conical wall, 3c: cylindrical portion, 3m1 to 3mn: microporous layer, 3h1 to 3hn: through hole, 5: conical outer wall, 5a: flange, 5aa: annular recess, 5b: conical wall, 5c: bottom, 5d: cylindrical portion, 6: air supply nozzle, 9: air filled chamber, 11: base, 51: microporous material, 53: sector ring piece, 101: compressed air supply device, 103: electrolytic polishing solution tank, 105: working electrode, A: compressed air, P: powder, R: electrolytic polishing solution

Claims

1. a conical inner wall that directly contains the powder; a conical outer wall surrounding the entire circumference of the conical inner wall; Equipped with The space between the inner and outer conical walls is filled with compressed air supplied through an air supply hole. An air-filled chamber is formed to fill the At least a portion of the conical inner wall is permeable to the compressed air supplied to the air filled chamber. The cone is made of a microporous material for aerating the powder inside the cone. And, The microporous material is made of metal and has a plurality of through holes penetrating in the layer thickness direction. It has The microporous material has a first surface that contacts the air-filled chamber and a second surface that does not contact the air-filled chamber. and a second surface of Each of the plurality of through holes has a hole diameter at the first surface that is larger than a hole diameter at the second surface. is set large, Hopper for powder supply.

2. The microporous material is configured to include a plurality of laminated microporous layers.

2. The powder feeding hopper of claim 1.

3. Each of the plurality of microporous layers is made of a metal sheet.

3. A powder feeding hopper according to claim 2.

4. The inner surface of the microporous material is a smooth electrolytically polished surface formed by electrolytic polishing. R, 2. The powder supply hopper according to claim 1.

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