Storage silo

Abstract

To provide a storage silo with a simple structure that can reliably prevent a hydrated material, such as hydrated sludge, from being consolidated or causing bridging, even if the hydrated material is stored in a storage tank.SOLUTION: A storage silo is provided with a storage tank 11 with a vertical cylindrical shape for storing a hydrated material. The lower part of the storage tank 11 is formed in a tapered shape of which a peripheral wall 12 gradually expands in diameter outward from the vertical direction toward its bottom surface 14.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a storage silo for storing wet material. [Background technology]

[0002] Conventionally, various types of silos are known for storing materials to be treated. Usually, when storing materials containing moisture, such as moisture-containing sludge (moisture content: about 85%), square tanks called hoppers are used because they are less likely to cause bridges and are easy to take out and supply. This is because it is easy to attach machines such as bridge breakers and to install screw conveyors at the bottom, making it easy to take out and supply moisture-containing sludge.

[0003] However, the hopper body has limitations in width, length (depth), and height. The reason for these limitations is that, in terms of width, if the width at which the bridge breaker is attached becomes too large, there is a strength problem that cannot accommodate that width, and in terms of length (depth), it is difficult for the bridge breaker to exceed a certain length due to its rotating mechanism. As for height, if the body becomes taller, wet sludge will adhere to the corners and the number of bridge breakers will increase proportionately, making it unrealistic, and also because of the angular shape, numerous reinforcements will be required to provide strength.

[0004] In this way, if the hopper body becomes large, it becomes impossible to add additional equipment from the manufacturing factory, and it must be procured locally, which results in huge manufacturing costs. Therefore, the size of the hopper body, which is a square tank, is 18 to 20 m 3 The front and rear were considered to be the limit, and when storing a large amount of wet sludge, multiple hoppers were required, which posed the problem of requiring a large amount of land area for their installation.

[0005] Therefore, the above-mentioned problems can be almost completely solved by adopting, for example, the cylindrical silo described in Patent Document 1, instead of the above-mentioned square tank. When storing objects with a dry surface in such a cylindrical silo, if the moisture content of the objects is approximately 10% or less, the objects themselves have no adhesion or viscosity and are fluid, so there is thought to be no particular problem with the storage. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2004-35250 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the cylindrical silo described in Patent Document 1, when storing wet sludge, the sludge has a tendency to stick to itself, is viscous, etc., and the following problem occurs when the height dimension is large: The pressure from the weight of the wet sludge from above in the silo compresses the wet sludge and squeezes out the water in the wet sludge, so there is a high possibility that the wet sludge will become consolidated.

[0008] In addition, pressure from above inside the silo exerts lateral pressure on the inner wall of the silo, and the lateral pressure on the inner wall increases the further down the silo goes. This causes the wet sludge to lose the force that tries to drop to the bottom, and sometimes a bridge is formed where the wet sludge completely solidifies above the bridge breaker at the bottom. This can also cause a situation where the wet sludge cannot be discharged by the screw conveyor below the bottom.

[0009] The present invention has been made in consideration of the problems associated with the conventional technology as described above, and aims to provide a storage silo that can reliably prevent the formation of compacted or bridging water-containing materials with a simple structure, even when storing water-containing materials such as water-containing sludge in a storage tank. [Means for solving the problem]

[0010] In order to achieve the above object, one aspect of the present invention is to provide a method for manufacturing a semiconductor device comprising the steps of: In a storage silo for storing wet material, The storage tank is provided with a vertical cylindrical shape for storing water-containing material, and the lower part of the storage tank is formed in a tapered shape in which the peripheral wall expands outward from the vertical direction toward the lower bottom surface portion, gradually increasing in diameter. Effect of the Invention

[0011] According to the storage silo of the present invention, even when a water-containing material such as water-containing sludge is stored in the storage tank, the simple structure can reliably prevent the water-containing material from becoming consolidate or bridging occurs. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is a vertical cross-sectional view showing the internal structure of a storage silo according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged view of part II in FIG. [Diagram 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 2 is an explanatory diagram showing the pressure applied to wet sludge stored in a storage silo according to an embodiment of the present invention. [Diagram 5] FIG. 2 is an enlarged vertical cross-sectional view showing a main part of the storage silo according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, a representative embodiment of the present invention will be described with reference to the drawings. The storage silo 10 according to this embodiment is for storing a water-containing material. Here, the water-containing material is, for example, water-containing sludge (water content: about 85%) generated in a sewage treatment plant or the like. Such water-containing sludge is temporarily stored in this storage silo 10 before being treated, for example, in a drying device.

[0014] The following description will be given of the water-containing material stored in the storage silo 10 using water-containing sludge (water content: about 85%) as an example, but the water-containing material is not necessarily limited to water-containing sludge. Water-containing materials include a wide variety of materials that contain a relatively large amount of water, such as food waste, leftover food, food scraps, sludge, livestock manure, etc., and they come in a wide variety of forms, such as granular, powdered, liquid, and lumpy, and the specific water content of each material is also diverse.

[0015] <About Storage Tank 11> 1, the storage tank 11, which constitutes the main part of the storage silo 10, is generally vertical and cylindrical, and is made of metal such as stainless steel or iron. The storage tank 11 is installed on the floor of the installation site with its axis vertical, using a stand 11a provided on its underside.

[0016] The storage tank 11 is basically a cylinder with the same cross-sectional area on the inside of the peripheral wall 12 from the top surface portion 13 downward, but the lower portion 11b is formed in a tapered shape in which the peripheral wall 12 gradually expands in diameter as it expands outward from the vertical direction toward the lower bottom surface portion 14. Here, the peripheral wall 12 of the tapered lower portion 11b is inclined downward at an angle of, for example, 1° to 5° from the vertical direction toward the outside. Therefore, the area of ​​the bottom surface portion 14, which is also approximately horizontal, is larger than that of the top surface portion 13, which is also approximately horizontal.

[0017] An inlet 15 for introducing wet sludge into the storage tank 11 is provided on the top surface 13 of the storage tank 11. The inlet 15 is normally closed by a lid. Note that a plurality of inlets 15 may be provided. Alternatively, the top surface 13 itself may be configured as an openable and closable lid, and wet sludge may be introduced with the top surface 13 open. Alternatively, a screw conveyor or the like may be connected to the peripheral wall 12 near the top surface 13 of the storage tank 11, allowing wet sludge to be introduced continuously.

[0018] Meanwhile, a discharge port 16 is provided in the bottom surface 14 of the storage tank 11, which extends radially in a substantially rectangular shape from an eccentric position that does not overlap with the bottom surface 44 of a rotor 40 described later. Discharge means 17 for discharging the wet sludge fed into the discharge port 16 to the outside is provided below the bottom surface 14 at a position communicating with the discharge port 16. As shown in Figures 2 and 3, the discharge means 17 is configured, for example, by inserting a screw 17b, which is rotated by power, into a narrow casing 17a disposed horizontally in the radial direction below the bottom surface 14.

[0019] The upper part of the front half of the casing 17a, including the starting end side of the screw 17b, is connected in communication with the discharge port 16. The discharge means 17 discharges the wet sludge that has fallen from the discharge port 16 to the outside from the terminal end side of the casing 17a by rotating the screw 17b. In Fig. 3, when the screw 17b is rotated, the wet sludge is transported to the right side in the figure and discharged. Although not shown, the discharge port 16 may be provided with an openable and closable shutter.

[0020] <About the rotating shaft 20> As shown in Fig. 1, a rotating shaft 20 extending from the bottom surface 14 along a vertical axis is disposed at the bottom inside the storage tank 11. The rotating shaft 20 is inserted into the interior from below the bottom surface 14 of the storage tank 11, airtightly penetrating the center of the bottom surface 14. A bearing 21 is provided below the bottom surface 14 to rotatably support the lower end of the rotating shaft 20. The rotating shaft 20 is driven to rotate by an electric motor (not shown) disposed below the bottom surface 14. A rotating blade 30 and a rotating body 40 are each integrally attached to the rotating shaft 20 inside the storage tank 11.

[0021] <About Rotor Blade 30> 3, the rotating blades 30 are rotatably supported by the rotating shaft 20 along the bottom surface 14 in the storage tank 11 and are configured to rotate synchronously with the rotation of the rotating shaft 20. The rotating blades 30 send the wet sludge on the bottom surface 14 to the discharge outlet 16 as they rotate.

[0022] The rotating blades 30 are provided so as to extend radially at equal intervals around the rotating shaft 20. Each rotating blade 30 is formed as a plate extending linearly with a constant width. Here, the rotating blades 30 are formed so as to be inclined obliquely in the width direction, and although not shown, they are actually inclined at a predetermined angle with respect to the bottom surface portion 14. More specifically, the rotating blades 30 are inclined upward from one side edge 31 that extends radially and faces the direction of rotation to the other side edge 32 (see FIG. 3). This allows the rotating blades 30 to actively scrape off the wet sludge that accumulates on the bottom surface portion 14.

[0023] Furthermore, a protruding piece 33 is provided at the tip of one side edge 31 of the rotary vane 30, protruding in the direction of rotation of the rotary vane 30 (arrow R in FIG. 3). The protruding piece 33 can efficiently scrape off wet sludge that accumulates in corners between the bottom portion 14 and the inner surface of the peripheral wall 12 (hereinafter referred to as the "inner wall"). The rotary vanes 30 in this embodiment are three in total, and are provided with a phase shift of 120 degrees with respect to the rotary shaft 20, but the number of rotary vanes 30 is not particularly limited, and may be, for example, two to four.

[0024] <About the rotating body 40> As shown in Fig. 1, the rotor 40 is supported integrally on the rotor blades 30 by the rotor shaft 20 in the storage tank 11 and is configured to rotate in synchronization with the rotor shaft 20 and the rotor blades 30. The rotor 40 pushes the surrounding wet sludge downward as it rotates.

[0025] Rotating body 40 is formed in a cone shape with rotating shaft 20 as its axis, and is provided on outer circumferential surface 41 with spiral ridges 42 that push wet sludge downward as it rotates. Rotating body 40 is configured such that as it rotates, ridges 42 scrape off wet sludge in contact with the periphery and push it downward to rotor blades 30. Rotating body 40 like this makes it possible to break down the consolidated state of the wet sludge stored in storage tank 11, particularly in the lower central interior.

[0026] The specific cross-sectional shape and dimensions of the helical ridge 42 are design matters that can be appropriately determined. The helical shape of the ridge 42 is also basically formed such that the length of the moving radius gradually increases from the apex 43 to the bottom surface 44, the moving radius angle is constant, and the direction of the rotation axis is also constant, but the rolling width does not necessarily have to be constant. As shown in Fig. 1, the rolling width of the ridge 42 may be formed so as to gradually increase from the apex 43 to the bottom surface 44.

[0027] <Function of Storage Silo 10> Next, the operation of the storage silo 10 according to this embodiment will be described. In Fig. 1, wet sludge is introduced into storage tank 11 through inlet 15 in top portion 13 and stored therein. At this time, if the amount of wet sludge to be introduced is large, it may be introduced with top portion 13 open.

[0028] The wet sludge stored in the storage silo 10 is more sticky or viscous than other storage objects, so if the height of the storage tank 11 is large, the pressure from the weight of the wet sludge from above in the storage tank 11 will compress the wet sludge, especially that accumulated at the bottom of the storage tank 11, and the water will be squeezed out and the sludge will become consolidated.

[0029] However, in the present storage silo 10, the peripheral wall 12 at the bottom of the storage tank 11 is tapered outward, and the cross-sectional area gradually increases. Therefore, as shown in Fig. 4, the wet sludge tends to spread outward due to pressure from above, and the lateral pressure becomes a downward pressure along the tapered slope, causing the wet sludge to lose its compacted state and be pushed downward. This makes it possible to prevent the wet material from sticking to the inner wall of the storage tank 11 and the formation of bridges.

[0030] The wet sludge accumulated on the bottom surface 14 of the storage tank 11 is sent to the discharge port 16 on the bottom surface 14 by the rotating blades 30 which rotate as the rotating shaft 20 is driven to rotate. Here, the rotating blades 30 extend radially from the rotating shaft 20 along the bottom surface 14, and can actively scrape off the wet sludge that has accumulated on the bottom surface 14. Therefore, even if some of the wet sludge becomes consolidated on the bottom surface 14 of the storage tank 11, the consolidated state of the wet sludge is actively broken, and the wet sludge can be reliably sent to the discharge port 16 and dropped down.

[0031] Moreover, a rotor 40 is also provided above the rotor impeller 30, and the rotor 40 protrudes in a conical shape along the center of the storage tank 11. The rotor 40 rotates in synchronization with the rotor impeller 30 as the rotary shaft 20 is driven to rotate. As a result, the rotor 40 can push the wet sludge in the lower center of the storage tank 11 toward the rotor impeller 30 by means of the spiral ridges 42 on its outer circumferential surface 41, and can reliably break down any consolidated state of the wet sludge.

[0032] The height of the apex 43 of the conical shape of the rotating blade 30 and the diameter (area) of the bottom surface 44 are design items that can be determined as appropriate, but it is particularly preferable to vary the diameter (area) of the bottom surface 44 according to the moisture content of the wet sludge. Specifically, for example, when the moisture content of the wet sludge is relatively hard, such as around 70%, by increasing the diameter (area) of the bottom surface 44 of the rotating blade 30, the wet sludge will tend to crumble overall even if it is in a consolidated state.

[0033] As described above, with this storage silo 10, the destruction of the consolidated state of the water-containing sludge due to the taper of the lower peripheral wall 12 of the storage tank 11, combined with the destruction of the consolidated state of the water-containing sludge due to the rotating body 40 in the center of the lower part, reliably prevents the formation of a consolidated state or bridges in the water-containing sludge within the storage tank 11, making it possible to steadily discharge the water-containing sludge.

[0034] In particular, as a special feature of the present storage silo 10, as shown in Figure 5, it is preferable to match the height H of the top end 43 of the rotor 40 to the height of the boundary 11c where the peripheral wall 12 of the storage tank 11 starts to slope from the top to the bottom. It is also preferable to configure the angle θ at which the peripheral wall 12 of the lower part of the storage tank 11 slopes outwardly to match the slope of the outer circumferential surface 41 of the rotor 40. With this configuration, it is possible to more reliably prevent the formation of a compacted state or bridges in the wet sludge in the storage tank 11.

[0035] [Configuration and Effects of the Present Invention] Although various embodiments of the present invention have been described above, the present invention is not limited to the above-described various embodiments. The present invention derived from the above-described various embodiments will be described below.

[0036] [1] First, the present invention relates to a storage silo 10 for storing a water-containing material, The storage tank 11 is vertically cylindrical and stores water-containing material. The lower part of the storage tank 11 has a peripheral wall 12 that is tapered so that the peripheral wall 12 expands outward from the vertical direction toward the lower bottom surface 14, gradually increasing in diameter.

[0037] In this storage silo 10, even if the water-containing sludge in the lower part of the storage tank 11 is compressed and put into a consolidated state due to the pressure of the water-containing sludge from above in the storage tank 11, the lower peripheral wall 12 is tapered outward and the cross-sectional area gradually increases. Therefore, the water-containing sludge tries to spread outward due to the pressure from above, and the lateral pressure becomes a downward pressure along the tapered slope, destroying the consolidated state of the water-containing sludge and pushing it downward. This makes it possible to prevent the water-containing material from sticking to the inner wall of the storage tank 11 and the formation of bridges.

[0038] [2] The present invention is also characterized in that the storage tank 11 is provided with a rotating blade 30 that is rotatably supported on the bottom portion 14 by a rotating shaft 20 aligned along a vertical axis, and that sends the water-containing material to a discharge outlet 16 at the bottom portion 14 as it rotates.

[0039] Such rotating blades 30 can actively scrape off the wet sludge that accumulates on the bottom surface 14. Therefore, even if some of the wet sludge becomes consolidated on the bottom surface 14 of the storage tank 11, the consolidated state of the wet sludge is actively broken, and the wet sludge can be reliably sent to the discharge port 16 and dropped down.

[0040] [3] The present invention is further characterized in that it comprises a rotor 40 which is supported within the storage tank 11 by the rotating shaft 20 so as to be rotatable integrally with the rotating blades 30, has a conical shape with the rotating shaft 20 as its axis, and has a spiral ridge 42 on its outer circumferential surface 41 which pushes the water-containing material downward as it rotates.

[0041] Such a rotor 40 rotates integrally on the rotor blades 30, and the spiral protrusions 42 on its outer surface 41 can push the wet sludge in the central interior below the storage tank 11 toward the rotor blades 30, ensuring that any compacted wet sludge can be broken down.

[0042] [4] The present invention is also characterized in that a discharge means 17 for discharging the water-containing material sent to the discharge outlet 16 to the outside is provided below the bottom portion 14 of the storage tank 11 at a position communicating with the discharge outlet 16. Such a discharge means 17 makes it possible to efficiently discharge the water-containing matter that has fallen from the discharge port 16 on the bottom portion 14 of the storage tank 11 to the outside.

[0043] [5] Furthermore, the present invention is characterized in that the height H of the top end 43 of the rotating body 40 is adjusted to the height of the boundary 11c where the peripheral wall 12 of the storage tank 11 begins to slope from the cylindrical shape from the top to the bottom, and the angle θ at which the peripheral wall 12 of the lower part of the storage tank 11 slopes outward is configured to match the slope of the outer peripheral surface 41 of the rotating body 40. The inventors have confirmed through experiments that such a configuration makes it possible to more reliably prevent the occurrence of a consolidation state or bridges in the water-containing sludge within the storage tank 11.

[0044] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention includes modifications and additions that do not deviate from the gist of the present invention. For example, the specific shapes of the storage tank 11, the rotor blades 30, the rotor 40, etc. of this embodiment are not limited to those shown in the drawings. [Industrial Applicability]

[0045] INDUSTRIAL APPLICABILITY The storage silo of the present invention is capable of storing various kinds of wet materials, and can be widely used, particularly as a storage silo capable of preventing the occurrence of compaction or bridging of wet materials. [Explanation of symbols]

[0046] 10…Storage silo 11…Storage tank 12...Peripheral wall 13...Top part 14…Bottom part 15...Inlet 16…Discharge port 17...Discharge means 17a…Casing 17b...Screw 20…Rotation axis 21...Bearing 30...Rotor blade 31...One side edge 32…Other side edge 33...Protruding piece 40...Rotating body 41...Outer surface 42...projection 43...apex 44…Bottom

Claims

1. In a storage silo for storing wet material, A storage silo is equipped with a vertical cylindrical storage tank for storing wet material, and the lower part of the storage tank is formed in a tapered shape in which the peripheral wall expands outward from the vertical direction toward the lower bottom portion, gradually increasing in diameter.

2. 2. The storage silo according to claim 1, characterized in that it is rotatably supported on the bottom portion by a rotating shaft along a vertical axis within the storage tank, and is provided with rotating blades that send water-containing material to a discharge outlet at the bottom portion as it rotates.

3. The storage silo according to claim 2, characterized in that it comprises a rotor that is supported within the storage tank so as to be rotatable integrally on the rotor blades by the rotor shaft, has a conical shape with the rotor shaft as its axis, and has a spiral ridge on its outer circumferential surface that pushes water-containing material downward as it rotates.

4. 4. The storage silo according to claim 3, further comprising a discharge means for discharging the water-containing material fed into the discharge outlet to the outside, the discharge means being provided below the bottom portion of the storage tank and in communication with the discharge outlet.

5. A storage silo as described in claim 4, characterized in that the height of the top end of the rotating body is adjusted to the height of the boundary between the peripheral wall of the storage tank and the lower part where the peripheral wall begins to slope from the cylindrical shape from the top, and the angle at which the peripheral wall of the lower part of the storage tank slopes outward is configured to match the slope of the outer circumferential surface of the rotating body.

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