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 hydrates.

Background Art

[0002] Conventionally, various silos for storing processed materials are known. Usually, when storing a hydrate such as water-containing sludge (water content: around 85%), a square tank that is unlikely to form a bridge and is easy to take out and supply, so-called a hopper, is used. This is because it is easy to attach a machine such as a bridge breaker, and it is easy to install a screw conveyor or the like at the bottom to take out and supply water-containing sludge or the like.

[0003] However, the hopper body has limitations in width, length (depth), and height. The reason for this limitation is that, regarding the width, if the mounting width of the bridge breaker becomes large, there are strength problems that cannot be accommodated. Regarding the length (depth), the bridge breaker has a rotating mechanism, so it is difficult to exceed a certain length. Regarding the height, if the body becomes high, water-containing sludge adheres to the corners, and at the same time, the number of bridge breakers increases proportionally, which is not practical. Also, because it is angular, a large number of reinforcements are required for strength.

[0004] Thus, when the hopper body becomes large, it becomes impossible to add facilities from the manufacturing factory, and it becomes necessary to procure locally, resulting in an enormous manufacturing cost. Therefore, the size of the hopper body, which is a square tank, is limited to around 18 - 20 m 3 front and back. When storing a large amount of water-containing sludge, a problem arises in that a plurality of hoppers are required, and a large floor area is also required for their installation.

[0005] Therefore, if a cylindrical silo, such as the one described in Patent Document 1, is adopted instead of the rectangular tank mentioned above, the aforementioned problems can be almost completely resolved. With such a cylindrical silo, when storing objects with a dry surface, if the moisture content of the objects is approximately 10% or less, the objects themselves do not adhere to each other and are fluid, so there are no particular problems with storage. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2004-35250 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, in the cylindrical silo described in Patent Document 1 mentioned above, when storing water-containing sludge, the following problems arise when the height dimension is large due to the adhesion or viscosity of the sludge. Specifically, the pressure from the weight of the water-containing sludge from above inside the silo compresses the water-containing sludge and squeezes out the water within it, making it highly likely that the water-containing sludge will become compacted.

[0008] Furthermore, the pressure from above within the silo creates lateral pressure on the inner wall, and this lateral pressure increases as you move towards the bottom. As a result, the force that would cause the water-containing sludge to fall downwards is lost, and bridging can occur above the bridge breaker at the bottom, where the water-containing sludge completely solidifies. Consequently, it may become impossible to discharge the water-containing sludge via the screw conveyor at the bottom.

[0009] This invention was made in view of the problems of the conventional technology described above, and aims to provide a storage silo that can reliably prevent the compaction or bridging of water-containing materials, such as water-containing sludge, with a simple structure, even when storing water-containing materials in the storage tank. [Means for solving the problem]

[0010] To achieve the aforementioned objectives, one aspect of the present invention is: In a storage silo for storing water-containing materials, The device is characterized by having a vertical cylindrical storage tank for storing water-containing materials, and the lower part of the storage tank being tapered, with the peripheral wall widening outward from the vertical towards the bottom surface and gradually increasing in diameter. [Effects of the Invention]

[0011] According to the storage silo of the present invention, even when storing water-containing materials such as water-containing sludge in a storage tank, it is possible to reliably prevent the compaction of water-containing materials or the occurrence of bridging with a simple configuration. [Brief explanation of the drawing]

[0012] [Figure 1] This is a longitudinal cross-sectional view showing the internal structure of a storage silo according to an embodiment of the present invention. [Figure 2] This is an enlarged view of section II in Figure 1. [Figure 3] This is a cross-sectional view taken along line III-III in Figure 1. [Figure 4] This is an explanatory diagram showing the pressure on water-containing sludge stored in a storage silo according to an embodiment of the present invention. [Figure 5] This is a vertical cross-sectional view showing an enlarged view of the main part of a storage silo according to an embodiment of the present invention. [Modes for carrying out the invention]

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

[0014] The hydrous substance stored in the storage silo 10 will be described below taking hydrous sludge (water content: around 85%) as an example. However, the hydrous substance is not necessarily limited to hydrous sludge. As long as the hydrous substance contains a relatively large amount of moisture, it covers a wide range, such as food waste, leftover meals, food residues, sludge, livestock manure, etc. Its form also corresponds to various types such as granular, powdery, liquid,块状, etc., and the specific moisture content of each is also diverse.

[0015] <Regarding the storage tank 11> As shown in FIG. 1, the storage tank 11 that forms the main part of the storage silo 10 is generally vertically cylindrical and is made of a metal material such as stainless steel or iron. The storage tank 11 is installed on the floor of the installation location in a posture where the axis is vertical by a pedestal 11a provided on its lower side.

[0016] Basically, the storage tank 11 has a uniform diameter from the upper surface portion 13 downward, where the cross-sectional area inside the peripheral wall 12 is the same. However, its lower part 11b is formed in a tapered shape where the peripheral wall 12 expands outward from the vertical direction toward the lower bottom surface portion 14 and gradually increases in diameter. Here, the peripheral wall 12 of the tapered lower part 11b is inclined, for example, 1° to 5° outward from the vertical direction downward. Therefore, the bottom surface portion 14, which is also substantially horizontal, has a larger area than the substantially horizontal upper surface portion 13.

[0017] An inlet 15 for injecting hydrous sludge into the storage tank 11 is provided on the upper surface portion 13 of the storage tank 11. The inlet 15 is usually closed by a lid. Note that a plurality of inlets 15 may be provided. Alternatively, the upper surface portion 13 itself may be configured as an openable / closable lid, and the hydrous sludge may be injected with the upper surface portion 13 opened. Or, a screw conveyor or the like may be connected to the peripheral wall portion 12 near the upper surface portion 13 of the storage tank 11 so that the hydrous sludge can be continuously injected.

[0018] On one side, the bottom surface portion 14 of the storage tank 11 is provided with a discharge port 16 that extends radially in a substantially rectangular shape from an eccentric position that does not overlap with the bottom surface 44 of the rotating body 40 to be described later. At a position below the bottom surface portion 14 and communicating with the discharge port 16, discharge means 17 for discharging the water-containing sludge fed into the discharge port 16 to the outside is provided. As shown in FIGS. 2 and 3, the discharge means 17 is configured by inserting a screw 17b that is rotationally driven by power into the inside of a narrow-width casing 17a that is horizontally disposed in the radial direction below the bottom surface portion 14, for example.

[0019] The upper half of the front side of the casing 17a including the start end side of the screw 17b is connected to the discharge port 16 in a communicating manner. The discharge means 17 discharges the water-containing sludge that has fallen from the discharge port 16 to the outside from the end side of the casing 17a by the rotational drive of the screw 17b. In FIG. 3, when the screw 17b is rotationally driven, the water-containing sludge is conveyed to the right side in the figure and discharged. Although not shown in the figure, the discharge port 16 may be provided with a shutter that can be opened and closed.

[0020] <Regarding the rotating shaft 20> As shown in FIG. 1, a rotating shaft 20 extending along the vertical axis is disposed below the storage tank 11 from the bottom surface portion 14. The rotating shaft 20 is inserted into the inside through the center of the bottom surface portion 14 in an airtight manner from below the bottom surface portion 14 of the storage tank 11. A bearing 21 for rotatably supporting the lower end side of the rotating shaft 20 is provided below the bottom surface portion 14. The rotating shaft 20 is rotationally driven by an electric motor (not shown) disposed below the bottom surface portion 14. A rotating blade 30 and a rotating body 40 are integrally attached to the rotating shaft 20 in the storage tank 11, respectively.

[0021] <Regarding the rotating blade 30> As shown in FIG. 3, the rotating blade 30 is rotatably supported on the bottom surface portion 14 in the storage tank 11 by the rotating shaft 20 and is configured to rotate synchronously with the rotational drive of the rotating shaft 20. The rotating blade 30 feeds the water-containing sludge on the bottom surface portion 14 to the discharge port 16 as it rotates.

[0022] The rotating blades 30 are arranged to extend radially at equal intervals around the rotation axis 20. Each rotating blade 30 is formed as a plate-like shape extending linearly with a constant width. The rotating blades 30 are formed to be inclined diagonally in the width direction, and although not shown in the illustration, they are actually inclined at a predetermined angle with respect to the bottom surface 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 Figure 3). As a result, the rotating blades 30 actively scrape off water-containing sludge that accumulates on the bottom surface 14.

[0023] Furthermore, a protruding piece 33 is provided at the tip of one side edge 31 of the rotating blade 30, projecting toward the direction of rotation of the rotating blade 30 (arrow R in Figure 3). The protruding piece 33 allows for efficient scraping of water-containing sludge that accumulates in the corners between the bottom surface 14 and the inner surface of the peripheral wall 12 (hereinafter referred to as the "inner wall"). In this embodiment, there are a total of three rotating blades 30, which are arranged with a phase difference of 120 degrees relative to the rotation axis 20. However, the number of rotating blades 30 is not particularly limited, and for example, 2 to 4 blades are suitable.

[0024] <Regarding the rotating body 40> As shown in Figure 1, the rotating body 40 is integrally supported on the rotating blades 30 by the rotating shaft 20 within the storage tank 11 and is configured to rotate in sync with the rotating shaft 20 and the rotating blades 30. As the rotating body 40 rotates, it pushes the surrounding water-containing sludge downwards.

[0025] The rotating body 40 is formed in a conical shape with the rotation axis 20 as its center, and its outer surface 41 is provided with spiral ridges 42 that push water-containing sludge downward as it rotates. The rotating body 40 is configured to push the water-containing sludge in contact with its surroundings towards the rotating blades 30 below by scraping it off with the ridges 42 as it rotates. With such a rotating body 40, it is possible to break up the compacted state of the water-containing sludge stored in the storage tank 11, especially in the lower central part.

[0026] The specific cross-sectional shape and dimensions of the spiral projection 42 are design matters that can be determined as appropriate. Furthermore, while the spiral shape of the projection 42 is basically formed with the length of the moving diameter gradually increasing from the top 43 to the bottom 44, the moving diameter angle remaining constant, and the direction of the pivot axis remaining constant, the winding width does not necessarily have to be constant. As shown in Figure 1, the winding width of the projection 42 may be formed to gradually widen from the top 43 to the bottom 44.

[0027] <Function of storage silo 10> Next, the operation of the storage silo 10 according to this embodiment will be described. In Figure 1, water-containing sludge is introduced into the storage tank 11 through the inlet 15 located on the top surface 13 and stored. If the amount of water-containing sludge to be introduced is large, it may be introduced with the top surface 13 open.

[0028] Because the water-containing sludge stored in the storage silo 10 is more adhesive or viscous than other stored materials, if the height dimension of the storage tank 11 is large, the pressure from the weight of the water-containing sludge from above in the storage tank 11 will compress the water-containing sludge, especially that accumulated at the bottom of the storage tank 11, resulting in a compacted state where the water is compressed.

[0029] However, in this storage silo 10, the lower peripheral wall 12 of the storage tank 11 is tapered and widens outward, and the cross-sectional area gradually increases. Therefore, as shown in Figure 4, the water-containing sludge tends to spread laterally due to the pressure from above, and the lateral pressure becomes a downward pressure along the slope of the taper, breaking down the compacted state of the water-containing sludge and pushing it downward. Consequently, it is possible to prevent the adhesion of water-containing material to the inner wall of the storage tank 11 and the formation of bridges.

[0030] The water-containing sludge accumulated on the bottom surface 14 of the storage tank 11 is sent to the discharge port 16 located on the bottom surface 14 by the rotating blades 30, which rotate in conjunction with the rotational drive of the rotating shaft 20. The rotating blades 30 extend radially from the rotating shaft 20 along the bottom surface 14, and can actively scrape off the water-containing sludge that accumulates on the bottom surface 14. Therefore, even if some of the water-containing sludge on the bottom surface 14 of the storage tank 11 becomes compacted, the compaction of the water-containing sludge is actively broken up, and it can be reliably sent to the discharge port 16 and dropped down.

[0031] Furthermore, a rotating body 40 is also provided above the rotating blades 30, and the rotating body 40 protrudes in a conical shape along the center of the storage tank 11. The rotating body 40 rotates in sync with the rotating blades 30 as the rotating shaft 20 is driven. As a result, the rotating body 40, with its spiral ridges 42 on its outer circumferential surface 41, pushes the water-containing sludge in the lower central part of the storage tank 11 towards the rotating blades 30, and if the water-containing sludge is compacted, it can be reliably broken up.

[0032] The height of the apex 43 and the diameter (area) of the base 44 of the conical shape of the rotating blade 30 are design items that can be determined as appropriate, but it is especially good to vary the diameter (area) of the base 44 according to the water content of the water-containing sludge. Specifically, for example, if the water-containing sludge is relatively hard with a water content of around 70%, increasing the diameter (area) of the base 44 of the rotating blade 30 makes it easier to break down the water-containing sludge even if it is in a compacted state.

[0033] As described above, with this storage silo 10, the combination of the disruption of the compacted state of water-containing sludge by the taper of the peripheral wall 12 at the bottom of the storage tank 11 and the disruption of the compacted state of water-containing sludge by the rotating body 40 in the lower center reliably prevents the formation of compacted state or bridging of water-containing sludge inside the storage tank 11, and enables stable discharge of water-containing sludge.

[0034] In particular, as a special feature of this storage silo 10, as shown in Figure 5, it is preferable to match the height H of the top 43 of the rotating body 40 to the height of the boundary 11c between the lower part of the peripheral wall 12 of the storage tank 11 and the lower part where the cylindrical shape from the top begins to slope. Furthermore, it is preferable to configure the angle θ at which the lower peripheral wall 12 of the storage tank 11 slopes outward to match the slope of the outer surface 41 of the rotating body 40. With such a configuration, it is possible to more reliably prevent the compaction of water-containing sludge or the occurrence of bridging within the storage tank 11.

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

[0036] [1] First, the present invention relates to a storage silo 10 for storing water-containing materials, The device is characterized by having a vertical cylindrical storage tank 11 for storing water-containing materials, and the lower part of the storage tank 11 is formed in a tapered shape in which the peripheral wall 12 widens outward from the vertical direction toward the bottom surface 14 below, gradually increasing in diameter.

[0037] With this type of storage silo 10, even if the water-containing sludge at the bottom of the storage tank 11 is compressed and consolidated by the pressure of the water-containing sludge from above, the lower peripheral wall 12 is tapered and widens outwards, so the cross-sectional area gradually increases. Therefore, the water-containing sludge tends to spread laterally due to the pressure from above, and the lateral pressure becomes a downward pressure along the slope of the taper, breaking the consolidated state of the water-containing sludge and pushing it downwards. Consequently, it is possible to prevent the adhesion of water-containing material to the inner wall of the storage tank 11 and the formation of bridges.

[0038] [2] The present invention is further characterized in that it comprises a rotating blade 30 which is rotatably supported on the bottom surface 14 by a rotating shaft 20 along a vertical axis within the storage tank 11, and which sends water-containing material to an outlet 16 located on the bottom surface 14 as it rotates.

[0039] These rotating blades 30 can actively scrape off the water-containing sludge that accumulates on the bottom surface 14. Therefore, even if some of the water-containing sludge becomes compacted on the bottom surface 14 of the storage tank 11, the compaction of the water-containing sludge is actively broken up, and it can be reliably sent and dropped into the discharge port 16.

[0040] [3] The present invention is also characterized by comprising a rotating body 40 which is supported within the storage tank 11 so as to be integrally rotatable on the rotating blade 30 by the rotating shaft 20, has a conical shape with the rotating shaft 20 as its axis, and has spiral ridges 42 on its outer surface 41 that push water-containing material downward as it rotates.

[0041] Such a rotating body 40 rotates integrally on the rotating blades 30, and the spiral ridges 42 on its outer circumferential surface 41 can push the water-containing sludge in the central lower part of the storage tank 11 towards the rotating blades 30, and if the water-containing sludge is compacted, it can be reliably broken up.

[0042] [4] The present invention is further characterized in that a discharge means 17 is provided below the bottom surface 14 of the storage tank 11 at a position communicating with the discharge port 16 for discharging water-containing material sent to the discharge port 16 to the outside. This discharge means 17 makes it possible to efficiently discharge water-containing material that has fallen from the discharge port 16 at the bottom 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 43 of the rotating body 40 is matched to the height of the boundary 11c between the lower part of the peripheral wall 12 of the storage tank 11 and the lower part where the cylindrical shape from the top begins to slope, and the angle θ at which the lower peripheral wall 12 of the storage tank 11 slopes outward is matched to the slope of the outer peripheral surface 41 of the rotating body 40. Experiments by the inventors have confirmed that this configuration makes it possible to more reliably prevent the compaction or bridging of water-containing sludge within the storage tank 11.

[0044] Although embodiments of the present invention have been described above with reference to the drawings, the specific configurations are not limited to these embodiments, and any changes or additions that do not depart from the spirit of the invention are also included in the present invention. For example, the specific shapes of the storage tank 11, the rotating blades 30, the rotating body 40, etc. in this embodiment are not limited to those shown. [Industrial applicability]

[0045] The storage silo of the present invention is capable of storing various types of water-containing materials, and in particular, can be widely used as a storage silo that can prevent the compaction or bridging of water-containing 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... Rotating blades 31...One side edge 32…Other side edge 33...Protruding piece 40…Rotational body 41...Outer surface 42...projection 43...apex 44...Bottom

Claims

1. In a storage silo for storing water-containing materials, A storage silo characterized by having a vertical cylindrical shape and a storage tank for storing water-containing materials, wherein the lower part of the storage tank is formed in a tapered shape, with the peripheral wall widening outward from the vertical direction towards the bottom surface and gradually increasing in diameter.

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

3. The storage silo according to claim 2, characterized in that it comprises a rotating body which is supported within the storage tank by the rotating shaft so as to be rotatable as an integral part on the rotating blades, has a conical shape with the rotating shaft as its axis, and has spiral ridges on its outer surface that push water-containing material downward as it rotates.

4. The storage silo according to claim 3, characterized in that a discharge means for discharging water-containing material sent to the discharge port to the outside is provided at a position below the bottom surface of the storage tank that communicates with the discharge port.

5. The storage silo according to claim 4, characterized in that the height of the top of the rotating body is matched to the height of the boundary between the lower part of the storage tank's peripheral wall and the lower part where the cylindrical shape from the top begins to slope, and the angle at which the lower peripheral wall of the storage tank slopes outward is set to match the slope of the outer surface of the rotating body.

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