Granular material storage tank and method for assembling the granular material storage tank

Abstract

To provide a granular material storage tank and a method for assembling the granular material storage tank, in which the diameter and length of the barrel of the tank body of the granular material storage tank can be easily adapted to the volume and the installation space of the granular material to be stored, material costs and processing costs can be significantly reduced, and the convenience in transporting from a processing factory to an installation place is high, and the assembly at the installation place can be easily performed.SOLUTION: A granular material storage tank 100 of the invention comprises a cylindrical tank body 10, wherein the tank body 10 is composed of one or more cylindrical bodies 30 arranged in the vertical direction, and the cylindrical bodies 30 are composed of one or more outer wall members 50 whose ends in the circumferential direction are connected to each other and are curved in a circular arc shape in the circumferential direction by elastic deformation.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention mainly relates to a granular storage tank for storing granular contents such as grains, and a method for assembling the granular storage tank.

Background Art

[0002] Conventionally, in factories and the like that process granules such as grains (including rice, wheat, corn, and beans) and various pellets, a granular storage tank for storing the granules has been used. The shape of the tank body generally has a circular cross-section (cylindrical tank) or a rectangular cross-section (square tank). The width (barrel diameter) and height (barrel length) of the tank body are set to correspond to the volume of the granules to be stored and the installation space.

[0003] As a cylindrical granular storage tank, there is known one in which a metal plate is processed into a cylindrical shape, and a plurality of these cylinders are connected in the vertical direction to form a tank body. Flanges are provided at the upper and lower ends of each cylinder, and a large number of opening holes are provided in the flanges. When connecting the cylinders in the vertical direction, the opening holes of the flanges of the cylinders arranged vertically are joined with bolts to form a tank body with the required barrel length.

[0004] However, the tank body configured by connecting a plurality of such cylinders has the following problems.

[0005] Since a plurality of cylinders are connected by flanges provided at the upper and lower ends, rigidity is required for the cylinders themselves. Also, to form a large cylinder with a metal plate, a metal plate with a thickness corresponding to its size is required. When forming the cylinder with a highly rigid metal plate in this way, processing is not easy, and it is difficult to make the cross-sectional shape of the cylinder a perfect circle. Since it is difficult to form the inner surface side of the flanges provided at the upper and lower ends of the cylinder into a perfect circle, steps and gaps are likely to occur at the connection part between the flanges, and the granular stored material may remain in the steps and gaps. If the granules are grains or the like, there is a risk of pests occurring in the residues. Generally, granular material storage tanks have large volumes, with a minimum of 1 cubic meter and it is not uncommon for them to be as large as 30 cubic meters. Consequently, the entire load from the cylindrical body itself and the contents is applied to the flanges and the cylindrical bodies supporting the flanges, and due to the distortion at the contact surface between the flanges, a large uneven load occurs. To withstand such a large uneven load, the steel material used for the cylindrical bodies needs to be sufficiently thick (at least 2 mm) even for small diameters for strength reasons, and it is not uncommon for larger diameters to have a thickness of 5 mm or more. Furthermore, in order to allow the contents of the tank body to descend without resistance, it is desirable that the inner surface of the tank body be free of any snagging steps. To achieve this, it is necessary to change the diameters of the upper and lower ends of each cylindrical body so that the diameter of the upper end of the lower cylindrical body is slightly larger than the diameter of the lower end of the upper cylindrical body, so that there is no snagging step at the joint between the upper and lower cylindrical bodies, and this is not an easy process to manufacture. As the thickness of the steel material used for the cylindrical body increases, the weight of the cylindrical body also increases. Furthermore, when transporting it from the processing plant to the installation site, it is necessary to transport either the large cylindrical body or the assembled tank body, which inevitably results in an extremely inefficient method of transportation, much like transporting air. Therefore, it lacks convenience when transporting from the processing plant to the installation site.

[0006] In configurations where metal cylindrical bodies are joined vertically using flanges, the above-mentioned challenges exist. Therefore, modular tanks have been proposed that consist of subdivided panels connected to form the tank body. For example, a rectangular modular storage tank formed from unit panels and reinforcing frames has been proposed.

[0007] However, the rectangular, prefabricated storage tank, formed from unit panels and reinforcing frames, has the following challenges:

[0008] In rectangular, prefabricated storage tanks, the pressure from the contents is distributed across the large surface area of ​​each unit panel, which can lead to the panel bulging. To prevent the bulging of the unit panels, measures such as increasing the thickness of the steel plates that make up the unit panels, adding reinforcement to the unit panels, or providing flanges with connecting holes on all four sides of the unit panels for connection are necessary to increase the rigidity of the tank housing itself in accordance with the volume and weight of the contents being stored. As a result, the weight of the unit panels increases, leading to higher material and processing costs, and ultimately reducing the productivity of the unit panels.

[0009] On the other hand, although not a storage tank for granular materials, a cylindrical, prefabricated storage tank has been proposed for use as a storage tank for liquids (see, for example, Patent Document 1).

[0010] The cylindrical storage tank disclosed in Patent Document 1 consists of arc-shaped metal outer wall elements that form a cylindrical body, and the tank body is constructed by combining multiple metal outer wall elements. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Japanese Patent Publication No. 2009-12849 [Overview of the Initiative] [Problems that the invention aims to solve]

[0012] However, the diameter and length of the tank body of a granular material storage tank need to be set to correspond to the volume of granular material to be stored and the installation space, but Patent Document 1 does not disclose how to change the diameter or length of the tank body.

[0013] In particular, since the metal outer wall elements are formed by plastically deforming them into an arc shape, changing the diameter of the tank body requires changing the radius of curvature of the metal outer wall elements, making it difficult to change the diameter of the tank body.

[0014] Furthermore, arc-shaped metal exterior wall elements must be manufactured by processing metal sheets into an arc shape. Therefore, it is assumed that arc-shaped metal exterior wall elements have a thickness that allows them to be processed into an arc shape.

[0015] As the thickness of the steel material used for the arc-shaped metal exterior wall elements increases, the weight of the metal exterior wall elements increases, leading to higher material and processing costs. Furthermore, it becomes less convenient when transporting multiple metal exterior wall elements from the processing plant to the installation site.

[0016] The present invention has been made in view of the above problems, and aims to provide a granular storage tank and a method for assembling a granular storage tank that can easily accommodate the volume of granular material to be stored and the installation space by adjusting the diameter and length of the tank body of the granular storage tank, while also significantly reducing material costs and processing costs, and furthermore, providing convenience for transportation from the processing plant to the installation site and facilitating assembly at the installation site. [Means for solving the problem]

[0017] The granular material storage tank of the present invention is A granular material storage tank having a cylindrical tank body, The tank body is It consists of one or more cylindrical bodies arranged in the vertical direction, The aforementioned cylindrical body is The exterior wall members are connected at their ends in the circumferential direction and consist of one or more exterior wall members that are curved in an arbitrary arc shape in the circumferential direction by elastic deformation.

[0018] The present invention relates to a method for assembling a granular storage tank, which comprises a cylindrical tank body. The tank body is composed of one or more cylindrical bodies, The one or more outer wall members constituting the cylindrical body are connectable at their ends in the circumferential direction of the tank body, and are capable of bending into any arc shape in the circumferential direction by elastic deformation. Elastically deform one or more of the outer wall members in the circumferential direction, connect the ends of the outer wall members to form a cylindrical body, and form the tank body with one or more of the cylindrical bodies. A cylindrical body assembling step; An upper connecting step of connecting an inverted conical hopper or a lower member having a circular planar shape on the upper surface and the lower part of the tank body by insertion; including.

Effect of the Invention

[0019] According to the granular material storage tank and the assembling method of the granular material storage tank of the present invention, the body diameter and body length of the tank body of the granular material storage tank can be easily adapted to the volume of the granular material to be stored and the installation space, and the material cost and processing cost can be significantly suppressed. Furthermore, when stacking lightweight flat outer wall members and transporting them from the processing factory to the installation location, the convenience is high, the transportation cost can be extremely low, and processing costs such as welding at the installation location are not required, and moreover, assembly and disassembly can be easily performed.

Brief Description of the Drawings

[0020] [Figure 1] [[ID=二十]]Fig. 1 is a perspective view of a granular material storage tank according to Embodiment 1 of the present invention. [Figure 2] Fig. 2 is a front view of the outer wall member. [Figure 3] Fig. 3 is a cross-sectional view taken along line A-A of Fig. 2. [Figure 4] [[ID=二十九]]Fig. 4 is a flowchart showing the assembling process of the granular material storage tank according to Embodiment 1 of the present invention. [Figure 5] Fig. 5 is a perspective view showing a state where the outer wall members are connected to assemble the first cylindrical body. [Figure 6] Fig. 6 is a plan sectional view of the connecting portion where the outer wall members are connected. [Figure 7] Fig. 7 is a perspective view showing a state where the first cylindrical body and the second cylindrical body are connected. [Figure 8]Figure 8 is an enlarged cross-sectional view showing the state in which the end of the lower opening of the first cylinder in Figure 7 is inserted into the inside of the upper opening of the second cylinder. [Figure 9] Figure 9 is an enlarged cross-sectional view showing the state in which the lower end of the side connecting portion of the upper cylindrical body and the upper end of the side connecting portion of the lower cylindrical body are connected by a fixing member. [Figure 10] Figure 10 is an enlarged front view, taken from direction B in Figure 9, showing the portion where the lower end of the side connecting portion of the upper cylindrical body and the upper end of the side connecting portion of the lower cylindrical body are connected by a fixing member. [Figure 11] Figure 11 is a perspective view showing the tank body with the upper lid and lower hopper attached. [Figure 12] Figure 12 is a front view of the outer wall member constituting the granular material storage tank according to Embodiment 2 of the present invention. [Figure 13] Figure 13 is a perspective view showing the state in which the upper lid is attached to the tank body of the granular material storage tank according to Embodiment 3. [Figure 14] Figure 14 is a cross-sectional view showing the inclination angle of the inclined surface of the upper lid and the angle of repose of the granular material stored in the granular material storage tank. [Figure 15] Figure 15 is a cross-sectional view showing the movement of the surface of granular material when granular material stored in a granular material storage tank is discharged. [Modes for carrying out the invention]

[0021] A granular material storage tank according to one embodiment of the present invention is a granular material storage tank having a cylindrical tank body, The tank body is It consists of one or more cylindrical bodies arranged in the vertical direction, The aforementioned cylindrical body is It is composed of one or more outer wall members, the ends of which are connected in the circumferential direction and which are curved in an arc shape in the circumferential direction by elastic deformation (first configuration).

[0022] According to the above configuration, the tank body is composed of one or more cylindrical bodies, and the cylindrical bodies are made up of one or more outer wall members, the ends of which are connected in the circumferential direction and which are curved in an arbitrary arc shape in the circumferential direction by elastic deformation. Therefore, the diameter and length of the tank body can be easily changed by changing the number of cylindrical bodies arranged vertically and the number of outer wall members that make up the cylindrical bodies. Furthermore, since the exterior wall components are made of thin, elastically deformable plates that can be curved in an arc, material and processing costs can be reduced, and they are highly convenient because they can be stacked and transported and stored from the processing plant to the installation site. Furthermore, because the exterior wall components are thin and lightweight, they are easy to move and can be easily assembled at the installation site.

[0023] In the first configuration described above, The tank body is equipped with a lower member connected to the lower part, The lower member is formed as an inverted cone-shaped hopper or as a member with a circular top surface, and is connected to the lower part of the tank body. The lower end of the tank body and the upper end of the lower member may be connected by being inserted into each other (second configuration).

[0024] According to the above configuration, the tank body is composed of one or more cylindrical bodies, and each cylindrical body is composed of one or more elastically deformable outer wall members. In addition, a lower member with a circular top surface is connected to the lower part of the tank body. As a result, even if the tank body is composed of multiple cylindrical sections at the top and bottom, the tank body will elastically deform due to the internal pressure caused by the granular material filling inside, so that its cross-sectional shape naturally becomes a perfect circle. In this way, the cross-sectional shape of the tank body is formed into a circular shape by elastically deforming the outer wall members, thus eliminating the need for the precise machining required to create a circular cross-section, which is the most difficult aspect of forming a cylindrical tank body.

[0025] In the first or second configuration described above, The aforementioned cylindrical body is It has an upper opening and a lower opening, When the tank body is composed of a plurality of cylindrical bodies arranged vertically, In a pair of vertically adjacent cylindrical bodies, the upper opening of the lower cylindrical body and the end of the lower opening of the upper cylindrical body may be connected in an inserted state (third configuration).

[0026] According to the above configuration, when the tank body is composed of multiple cylindrical bodies vertically, the ends of a pair of cylindrical bodies adjacent to each other in the vertical direction are connected by insertion. Therefore, the length of the tank body can be easily changed by changing the number of cylindrical bodies connected in the vertical direction. Furthermore, because the thickness of the exterior wall members is thin, when the upper and lower cylindrical bodies are inserted and connected, steps or gaps are less likely to occur at the connection point. As a result, granular material is less likely to remain, and the occurrence of pests in the remaining material can be suppressed. Furthermore, flange processing is not required to connect adjacent cylindrical bodies in the vertical direction, which can reduce processing costs.

[0027] In the third configuration described above, In a pair of cylindrical bodies connected vertically, the length of the inner circumference of the upper opening of the lower cylindrical body may be made longer than the length of the outer circumference of the lower opening of the upper cylindrical body, or the length of the outer circumference of the upper opening of the lower cylindrical body may be made shorter than the length of the inner circumference of the lower opening of the upper cylindrical body (fourth configuration).

[0028] According to the above configuration, by setting the length of the outer circumference of the lower opening of the upper cylinder and the length of the inner circumference of the upper opening of the lower cylinder, or the length of the inner circumference of the lower opening of the upper cylinder and the length of the outer circumference of the upper opening of the lower cylinder to a predetermined relationship, when the tank body is composed of multiple cylinders, the lower opening of the upper cylinder and the upper opening of the lower cylinder of a pair of vertically adjacent cylinders can be connected by insertion.

[0029] In the above configurations 1 to 4, The aforementioned exterior wall member is The outer wall body is formed of a thin plate that is elastically deformable so as to bend in any arc shape in the circumferential direction of the cylindrical body, The cylindrical body has side connecting portions arranged at both ends of the outer wall body in the circumferential direction, which connect the ends of the outer wall members together. It may have (the fifth configuration).

[0030] According to the above configuration, the exterior wall member is made of a thin plate that can be elastically deformed to curve in any arc shape, and side connecting parts are provided at both ends of the exterior wall body to connect the ends of the exterior wall members. By forming the main body of the exterior wall from a thin, elastically deformable sheet metal, it can be bent into any desired arc shape with minimal force by hand, without the need for molding equipment or tools, and at the same time, material and processing costs can be reduced. Furthermore, in the state before the exterior wall members are elastically deformed and curved, the exterior wall members themselves are flat, plate-like bodies. This allows for a thinner exterior wall member thickness, and they can be efficiently transported and stored by stacking them flat from the processing plant to the installation site, making them highly convenient.

[0031] In the fifth configuration described above, The configuration may further include a fixing member for fixing the side connecting portion provided on the outer wall member constituting one of the vertically adjacent cylindrical bodies to the side connecting portion provided on the outer wall member constituting the other cylindrical body (sixth configuration).

[0032] According to the above configuration, a pair of cylindrical bodies adjacent to each other in the vertical direction are fixed by a fixing member. Therefore, the strength of the granular material storage tank can be improved with a simple configuration. Furthermore, the reason why the tank's outer wall members can be made of materials significantly thinner than conventional materials without structural problems is that when the tank is filled with the contents that bear the greatest load, a load is applied from the inside in the direction of expanding the diameter of the cylinder. However, because it is a cylindrical body to begin with, its shape does not change beyond that point, and even if a strong tensile load is applied to the outer wall members, the tensile strength of the thin metal outer wall members is extremely high, so they can withstand it sufficiently. In addition, even with regard to vertical loads on the outer wall members, the thin metal outer wall members exhibit extremely high strength because they are cylindrical bodies, so they can withstand that as well.

[0033] A method for assembling a granular storage tank according to one embodiment of the present invention is a method for assembling a granular storage tank having a cylindrical tank body, The tank body is composed of one or more cylindrical bodies, The one or more outer wall members constituting the cylindrical body are connectable at their ends in the circumferential direction of the tank body, and are capable of bending in an arc shape in the circumferential direction by elastic deformation. A cylindrical assembly step in which one or more of the outer wall members are elastically deformed in the circumferential direction, the ends of the outer wall members are connected to form a cylindrical body, and the tank body is formed by one or more of the cylindrical bodies, A lower connection step involves connecting an inverted cone-shaped hopper, or a lower member with a circular top surface, to the lower part of the tank body by insertion, This includes (the seventh component).

[0034] According to the above configuration, the outer wall members constituting the cylindrical body are formed from thin, plate-like bodies that can be elastically deformed to curve in any desired arc shape, thus facilitating the transportation and deformation of the outer wall members at the installation site. Furthermore, since the tank body is composed of one or more cylindrical bodies, the granular material storage tank can be easily assembled at the installation site. Furthermore, by connecting either an inverted cone-shaped hopper or a lower member with a circular top surface to the bottom of the tank body, a tank body with a circular cross-section can be easily assembled.

[0035] [Embodiment 1] The granular storage tank 100 according to Embodiment 1 of the present invention will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and their descriptions will not be repeated. In order to make the explanation easier to understand, the drawings referred to below show the configuration in a simplified or schematic manner, and some components are omitted. Also, the dimensional ratios between components shown in each figure do not necessarily represent the actual dimensional ratios.

[0036] In the following diagram, arrow U indicates the upward direction of the granular material storage tank 100, and arrow D indicates the downward direction. Arrow I indicates the inner surface of the granular material storage tank 100, and arrow O indicates the outer surface. Arrow C indicates the circumferential direction of the granular material storage tank 100.

[0037] [Overall structure] First, the overall configuration of the granular storage tank 100 and an outline of each component will be described. Figure 1 is a perspective view of the granular storage tank 100 according to Embodiment 1 of the present invention. The granular storage tank 100 according to this embodiment is used as a tank for storing grain (for example, rice) in a factory that processes grain. The granular storage tank 100 comprises a tank body 10, an upper lid 12, and a lower hopper 14.

[0038] The tank body 10 is a cylindrical body with a circular cross-section, and a storage space for storing granular material is formed inside. In this embodiment, the tank body 10 is constructed by connecting two cylindrical bodies 30 (first cylindrical body 31, second cylindrical body 32) in the vertical direction.

[0039] The upper lid portion 12 is the part that closes the top of the tank body 10. The upper lid portion 12 has a circular planar shape. The upper lid portion 12 is provided with a granular material inlet 13. The granular material inlet 13 communicates with the storage space inside the tank body 10. For example, a chute pipe (not shown) from an elevator that transports grain is connected to the granular material inlet 13. The grain supplied from the chute pipe is fed into the tank body 10 through the granular material inlet 13.

[0040] The lower hopper 14 is a conical hopper and is the part that closes the lower part of the tank body 10. The lower hopper 14 is an example of the lower member of the present invention. The upper surface of the lower hopper 14 is formed in a circular shape. A granular material discharge port 15 is formed in the center of the lower surface of the lower hopper 14. The granular material discharge port 15 is in communication with the storage space inside the tank body 10. The granular material stored in the granular material storage tank 100 is discharged to the outside of the tank body 10 through the granular material discharge port 15 and transported, for example, to a grain processing device (not shown).

[0041] The granular material discharge port 15 can be opened and closed by a shutter plate 16 attached to its lower surface. The shutter plate 16 is configured to switch between an open state and a closed state of the granular material discharge port 15 by an actuator 17. The actuator 17 is, for example, an air cylinder operated by pneumatic pressure, and the actuator 17 is driven and controlled by a drive control unit (not shown).

[0042] In addition to a conical hopper, a lower base plate can be used as the lower component of the present invention. The lower base plate is a flat plate-shaped component with a circular planar shape. The lower base plate is configured to allow for the mechanical removal of granular material by providing a hatch on its bottom or side surface (not shown).

[0043] Here, as shown in Figures 1 and 5, each cylindrical body 30 (first cylindrical body 31, second cylindrical body 32) constituting the tank body 10 is composed of multiple outer wall members 50 that are easily elastically deformed and curved in an arc shape in the circumferential direction of the tank body 10. Furthermore, the multiple outer wall members 50 are connected to each other by side connecting portions 54 located at their ends in the circumferential direction. In this embodiment, each cylindrical body 30 is composed of multiple outer wall members 50 connected to each other.

[0044] As shown in Figures 3 and 5, the outer wall member 50 is made of a thin steel plate such that when held at both ends, the central part curves and sags under its own weight when it is flat. Therefore, as shown in Figure 5, the assembly worker can connect multiple outer wall members 50 in the circumferential direction of the tank body 10 by elastically deforming the flat outer wall member 50 by hand to make it curve. Note that the outer wall members that make up the cylindrical body do not have to be multiple. A single outer wall member may be curved into an arc shape and its ends connected to form a cylindrical body.

[0045] As shown in Figure 7, the first cylindrical body 31 and the second cylindrical body 32, which are formed by connecting multiple exterior wall members 50, are connected by inserting the lower end of the first cylindrical body 31 into the upper end of the second cylindrical body 32. Specifically, they are connected by inserting the lower end of the first cylindrical body 31 (the end on the lower opening 312 side) into the upper opening 321 of the second cylindrical body 32. For this reason, the dimensions of the openings of the first cylindrical body 31 and the second cylindrical body 32 are set to allow them to be inserted and connected.

[0046] In this embodiment, the lower end of the first cylindrical body 31 (the end on the lower opening 312 side) is inserted into the inside of the upper opening 321 of the second cylindrical body 32, which is positioned lower. However, the invention is not limited to this configuration. Inserting them in this manner has the effect of making the internal step of the tank body downward, which makes it difficult for contents to remain. However, the steel plate used for the outer wall member is extremely thin. For this reason, the lower end of the first cylindrical body 31 (the end on the lower opening 312 side) may be inserted (externally fitted) into the outside of the upper opening 321 of the second cylindrical body 32, which is positioned lower. In the present invention, "cylinders are inserted into each other and connected" means both the state in which the end of the upper cylindrical body is inserted into the inside of the opening of the lower cylindrical body, and the state in which the end of the upper cylindrical body is externally fitted into the outside of the opening of the lower cylindrical body.

[0047] As shown in Figure 11, the upper lid 12 and lower hopper 14, which are located at the top and bottom of the tank body 10, are attached after the tank body 10 is constructed by connecting the first cylindrical body 31 and the second cylindrical body 32. Specifically, the upper lid 12 is attached to cover the opening at the top of the tank body 10 (the upper opening 311 of the first cylindrical body 31), and the lower hopper 14 is connected to the opening at the bottom of the tank body 10 (the lower opening 322 of the second cylindrical body 32) by being inserted into it.

[0048] In this way, by elastically deforming the outer wall member 50 that constitutes the tank body 10, the cross-sectional shape of the tank body 10 is formed to be circular, thus eliminating the need for precise machining to create a circular cross-sectional shape, which is the most difficult part of forming a cylindrical tank body 10.

[0049] As shown in Figure 1, in this embodiment, the tank body 10 is composed of two cylindrical bodies 30, a first cylindrical body 31 and a second cylindrical body 32. However, the number of cylindrical bodies that make up the tank body is not limited. The tank body may be composed of one cylindrical body or three or more cylindrical bodies. By changing the number of cylindrical bodies, the length of the tank body can be easily changed. The number of cylindrical bodies to be connected can be set according to conditions such as the type of granular material to be stored inside, the amount to be stored, and the installation space.

[0050] Furthermore, in this embodiment, each cylindrical body is constructed by connecting four outer wall members 50, but the number of outer wall members constituting the cylindrical body is not limited. By changing the number of outer wall members, the diameter of the tank body can be easily changed. The number of outer wall members constituting the cylindrical body can be set according to conditions such as the type of granular material to be stored inside, the amount to be stored, and the installation space.

[0051] The following sections will provide a detailed explanation of each component that makes up the tank body 10 of the granular material storage tank 100, as well as a detailed explanation of the assembly process of the granular material storage tank 100.

[0052] [Exterior wall components] First, let's describe the exterior wall member 50. Figure 2 is a front view of the exterior wall member 50. Figure 3 is a cross-sectional view taken along line A-A in Figure 2. The exterior wall member 50 is a component that makes up each cylindrical body 30. As shown in Figure 2, the exterior wall member 50 has an exterior wall body 52, a side connecting portion 54, and a reinforcing member 56.

[0053] The outer wall body 52 and the side connecting portion 54 are formed integrally, and the outer wall body 52 is formed of a plate-like body that can be elastically deformed to curve in an arc shape in the circumferential direction of the cylindrical body 30. The material constituting the outer wall body 52 and the side connecting portion 54 can be made of a general metal material used for granular storage tanks (for example, stainless steel plate), but the thickness of the steel plate is made to be extremely thin compared to the steel material constituting conventional granular storage tanks. The thickness is preferably such that an assembly worker can elastically deform the outer wall body 52, which is a flat plate-like portion, by hand to curve it. For example, the thickness of the steel plate is preferably about 0.3 mm to 1.0 mm, and more preferably about 0.5 mm to 0.8 mm.

[0054] In this embodiment, rectangular members can be used as the steel plates constituting the outer wall body 52 and the side connecting portion 54, obtained by cutting standard-length stainless steel plates with a standardized width (length C in the circumferential direction) into predetermined lengths. By cutting standard-length stainless steel plates into predetermined lengths and bending both sides to form the outer wall body 52 and the side connecting portion 54, material costs and processing costs can be significantly reduced. The dimensions of the outer wall body 52 can be set considering conditions such as the diameter and length of the tank body 10, as well as the availability of stainless steel plates and the convenience of transporting and storing the outer wall members 50.

[0055] The side connecting portion 54 is a flange-shaped member positioned at both ends in the circumferential direction of the outer wall body 52. ​​The side connecting portion 54 is formed integrally with the outer wall body 52 by bending a steel plate. The side connecting portion 54 is provided to connect the ends of the outer wall members 50. A reinforcing member 56 is attached to the side connecting portion 54. The reinforcing member 56 is attached to the outer wall body 52, for example, by spot welding. As the reinforcing member 56, for example, a steel material with an L-shaped cross-section can be used (see Figure 3).

[0056] The reinforcing member 56 may be attached to the outer wall body 52 and the side connecting portion 54 by welding or the like, or it may be separate from the outer wall body 52 and the side connecting portion 54, and when the outer wall members 50 are connected to form a cylindrical body, it may be brought into contact with the outer wall body 52 and the side connecting portion 54 and fastened together with bolts and nuts. Note that the reinforcing member 56 is not limited to an angle (L-shaped steel material), and for example, a thick metal plate may be used.

[0057] According to this embodiment, by forming an L-shaped end on the outer wall member 50 to form a side connecting portion 54, covering it with a reinforcing material 56 for reinforcement, and connecting the ends to form a cylindrical body 30, the following effects are obtained.

[0058] Although the outer wall member 50 is made of a thin plate-like body, the load applied to the outer wall member 50 when the contents are filled is a tensile load. Since the outer wall member 50 has extremely high tensile strength, it has sufficient strength even though it is a thin member. On the other hand, bending stress is applied to the joints between the ends of the outer wall member 50, so the strength of the tank body 10 can be increased by attaching and fixing a reinforcing member 56 to that part.

[0059] In this embodiment, the spacing between the side connecting portions 54, which are located at both ends of the outer wall body 52, is set to be L1 at both the upper and lower ends. In other words, the side connecting portions 54 are arranged to be parallel to each other.

[0060] The side connecting portion 54 is positioned such that its upper end coincides with the upper end of the outer wall body 52, and its lower end is positioned a distance H1 above the lower end of the outer wall body 52. ​​The lower end of the side connecting portion 54 is positioned above the lower end of the outer wall body 52 to prevent it from interfering with other cylindrical bodies 30 when connecting multiple cylindrical bodies 30 (first cylindrical body 31, second cylindrical body 32) by insertion, as shown in Figures 7 and 8.

[0061] The outer wall body 52 has multiple upper connecting holes 57 and lower connecting holes 58 formed therein. The positions of the upper connecting holes 57 and lower connecting holes 58 are set so that when multiple cylindrical bodies 30 (first cylindrical body 31, second cylindrical body 32) are connected by insertion, the lower connecting hole 58 of the upper cylindrical body 30 (first cylindrical body 31) and the upper connecting hole 57 of the lower cylindrical body 30 (second cylindrical body 32) are aligned and can be fixed by fastening means such as bolts and nuts.

[0062] As shown in Figure 3, the side connecting portions 54 located at both ends of the outer wall body 52 each have multiple side connecting holes 59 arranged vertically. The reinforcing member 56 also has openings 561 at positions corresponding to the side connecting holes 59. The positions of the side connecting holes 59 are set so that when connecting the ends of the outer wall members 50, the positions of the side connecting holes 59 of one side connecting portion 54 and the side connecting holes 59 of the other side connecting portion 54 are aligned and fixed by fastening means such as bolts and nuts.

[0063] [Assembly Process] Next, the process of assembling the granular material storage tank 100 using the outer wall member 50 described above will be explained. Figure 4 is a flowchart showing the assembly process of the granular material storage tank 100 according to Embodiment 1 of the present invention.

[0064] As shown in Figure 4, the assembly process of the granular storage tank 100 according to this embodiment includes a cylindrical assembly process, an upper connection process, and a lower connection process.

[0065] In the cylindrical assembly process, multiple outer wall members 50 are elastically deformed in the circumferential direction, and the ends of the outer wall members 50 are connected to form a cylindrical body 30 (first cylindrical body 31, second cylindrical body 32), and the first cylindrical body 31 and the second cylindrical body 32 are connected to form the tank body 10 (see Figures 5 to 7).

[0066] In the lower connection process, the lower hopper 14, which has a circular top surface, is connected to the lower part of the tank body 10 by insertion (see Figure 11).

[0067] Furthermore, the construction may also include an upper connection process. For example, it may simply involve passing metal beams in a cross shape, or laying flat plates on top of the beams. Alternatively, the upper lid 12, which has a circular planar shape, and the upper part of the tank body 10 can be connected by insertion (see Figure 11). The following description will use an example where the upper lid 12 and the upper part of the tank body 10 are connected by insertion.

[0068] Note that the cylindrical assembly process, the upper connection process, and the lower connection process do not necessarily have to be performed in this order. For example, the order of the upper connection process and the lower connection process may be reversed.

[0069] Furthermore, it is not necessary to complete the tank body 10 before performing the upper and lower connection processes. For example, after assembling the uppermost cylindrical body 30 (first cylindrical body 31), the upper connection process may be performed by connecting the upper lid 12 to the top of the uppermost cylindrical body 30 (first cylindrical body 31) before connecting the next cylindrical body 30 (second cylindrical body 32).

[0070] Similarly, after assembling the lowest cylindrical body 30 (second cylindrical body 32), a lower connection step may be performed in which the lower hopper 14 is connected to the lower part of the lowest cylindrical body 30 (second cylindrical body 32) before connecting the already assembled cylindrical body 30 (first cylindrical body 31).

[0071] The following describes in detail the assembly process of the granular storage tank 100 and the configuration of each part of the granular storage tank 100.

[0072] [Cylinder assembly process] Figure 5 is a perspective view showing the assembly of the first cylindrical body 31 by connecting the exterior wall members 50. Figure 6 is a plan cross-sectional view of the connecting portion where the exterior wall members 50 are connected.

[0073] As shown in Figure 5, the first cylindrical body 31 is assembled by connecting four outer wall members 50 in the circumferential direction. Since the outer wall members 50 are made of thin steel plates, the assembler can connect multiple outer wall members 50 in the circumferential direction by elastically deforming the flat outer wall body 52 by hand. The four outer wall members 50 are connected by their side connecting parts 54 (and reinforcing members 56) located at their ends in the circumferential direction.

[0074] As shown in Figure 6, the side connecting portions 54 and reinforcing members 56 of the outer wall members 50, which are arranged adjacent to each other in the circumferential direction of the first cylindrical body 31, are fastened together with bolts 61 and nuts 62. At this time, a spacer 64 is interposed between the pair of side connecting portions 54 to be fastened. The spacer 64 has a length from the top to the bottom of the side connecting portion 54. By changing the thickness of the spacer 64, the lengths of the inner and outer circumferential surfaces of the upper opening 311 and lower opening 312 of the first cylindrical body 31 can be adjusted.

[0075] In this embodiment, the thickness of the spacer 64 is constant at the top and bottom. Therefore, the length of the inner circumferential surface at the upper opening 311 and the lower opening 312 of the first cylindrical body 31 is the same, and the length of the outer circumferential surface at the upper opening 311 and the lower opening 312 of the first cylindrical body 31 is also the same.

[0076] In this later step, when connecting the first cylindrical body 31 and the second cylindrical body 32 to form the tank body 10, the lower end of the first cylindrical body 31 (the end on the lower opening 312 side) is inserted into the upper opening 321 of the second cylindrical body 32 to connect them (see Figures 7 and 8). For this reason, the length of the outer circumferential surface of the lower opening 312 of the first cylindrical body 31 must be set to be less than or equal to the length of the inner circumferential surface of the upper opening 321 of the second cylindrical body 32.

[0077] In this embodiment, the thickness of the spacer 64 used when assembling the first cylindrical body 31 is changed, and the thickness of the spacer 64 used when assembling the second cylindrical body 32 is changed, so that the length of the outer circumferential surface of the lower opening 312 of the first cylindrical body 31 is less than or equal to the length of the inner circumferential surface of the upper opening 321 of the second cylindrical body 32.

[0078] In this embodiment, the outer wall member 50 is made of a thin steel plate. Therefore, the length that needs to be adjusted with the spacer 64 so that the lower end of the first cylindrical body 31 (the end on the lower opening 312 side) is inserted into the upper opening 321 of the second cylindrical body 32 is very small. For this reason, the thickness of the spacer 64 used when assembling the first cylindrical body 31 and the thickness of the spacer 64 used when assembling the second cylindrical body 32 may all be different, but for example, spacer 64 of the same thickness may be prepared and the length of the inner circumferential surface may be adjusted by changing the number of interposed spacer 64 to change the thickness.

[0079] Furthermore, when connecting the first cylindrical body 31 and the second cylindrical body 32 to form the tank body 10, it is also possible to connect them by inserting the upper end of the second cylindrical body 32 (the end on the upper opening 321 side) into the lower opening 312 of the first cylindrical body 31. In this case, the outer wall member 50 is used upside down so that the side connecting portion 54 of the lower second cylindrical body 32 does not interfere with the side connecting portion 54 of the upper first cylindrical body 31.

[0080] Figure 7 is a perspective view showing the first cylindrical body 31 and the second cylindrical body 32 connected together. As shown in Figure 7, the first cylindrical body 31 is assembled by connecting the side connecting parts 54 provided on each of the four outer wall members 50, thereby connecting the four outer wall members 50 in the circumferential direction.

[0081] In other words, the lower end of the first cylindrical body 31 (the end on the lower opening 312 side) is inserted into the upper opening 321 of the second cylindrical body 32 to assemble it.

[0082] Here, when assembling the second cylinder 32, the first cylinder 31, which was assembled earlier, may be lifted upwards, and the second cylinder 32 may be assembled below the first cylinder 31. In this case, by lowering the first cylinder 31 onto the assembled second cylinder 32, the first cylinder 31 and the second cylinder 32 can be connected, and the granular storage tank 100 can be assembled even without a large workspace.

[0083] Furthermore, as described above, when the first cylindrical body 31 and the second cylindrical body 32 are connected to form the tank body 10, the lower end of the first cylindrical body 31 (the end on the lower opening 312 side) is inserted into the upper opening 321 of the second cylindrical body 32 to connect them (see Figures 7 and 8). For this reason, the thickness of the spacer 64 used when assembling the second cylindrical body 32 is set so that the length of the outer circumferential surface of the lower opening 312 of the first cylindrical body 31 is less than or equal to the length of the inner circumferential surface of the upper opening 321 of the second cylindrical body 32.

[0084] As shown in Figure 7, the first cylindrical body 31 and the second cylindrical body 32 are connected by inserting the lower end of the first cylindrical body 31 (the end on the lower opening 312 side) into the upper opening 321 of the second cylindrical body 32, thereby forming the tank body 10.

[0085] Here, the connection between the first cylindrical body 31 and the second cylindrical body 32 will be described in more detail. Figure 8 is an enlarged cross-sectional view showing the end of the lower opening 312 of the first cylindrical body 31 in Figure 7 being inserted into the upper opening 321 of the second cylindrical body 32. Figure 9 is an enlarged cross-sectional view showing the lower end of the side connecting portion 54 of the first cylindrical body 31 and the upper end of the side connecting portion 54 of the second cylindrical body 32 being connected by a fixing member 70. Figure 10 is an enlarged front view showing the part where the lower end of the side connecting portion 54 of the first cylindrical body 31 and the upper end of the side connecting portion 54 of the second cylindrical body 32 are connected by the fixing member 70, viewed from direction B in Figure 9.

[0086] As shown in Figure 8, when connecting the first cylindrical body 31 and the second cylindrical body 32, the lower end of the first cylindrical body 31 (the end on the lower opening 312 side) is inserted into the upper opening 321 of the second cylindrical body 32.

[0087] After the lower end of the first cylindrical body 31 (the end on the lower opening 312 side) is inserted into the upper opening 321 of the second cylindrical body 32, the upper connecting hole 57 provided in the outer wall member 50 constituting the second cylindrical body 32 and the lower connecting hole 58 provided in the outer wall member 50 constituting the first cylindrical body 31 are fastened together with bolts 65 and nuts 66.

[0088] Then, as shown in Figures 9 and 10, the side connecting portion 54 (and reinforcing member 56) provided on the outer wall member 50 constituting the second cylindrical body 32 and the side connecting portion 54 (and reinforcing member 56) provided on the outer wall member 50 constituting the first cylindrical body 31 are fixed together with fixing members 70. Specifically, the side connecting portion 54 (and reinforcing member 56) on the second cylindrical body 32 side and the side connecting portion 54 (and reinforcing member 56) on the first cylindrical body 31 side are sandwiched between two fixing members 70, and then the side connecting hole 59 provided in the side connecting portion 54 on the second cylindrical body 32 side and the through hole 71 of the fixing member 70 are fastened together with bolts 73 and nuts 74, and the side connecting hole 59 provided in the side connecting portion 54 on the first cylindrical body 31 side and the through hole 71 of the fixing member 70 are fastened together with bolts 73 and nuts 74.

[0089] The portion where the lower end of the first cylindrical body 31 (the end on the lower opening 312 side) is inserted into the upper opening 321 of the second cylindrical body 32 is fastened with a bolt 65 and a nut 66 between an upper connecting hole 57 provided in the outer wall member 50 constituting the second cylindrical body 32 and a lower connecting hole 58 provided in the outer wall member 50 constituting the first cylindrical body 31. In addition, the side connecting portion 54 (and reinforcing member 56) provided in the outer wall member 50 constituting the second cylindrical body 32 and the side connecting portion 54 (and reinforcing member 56) provided in the outer wall member 50 constituting the first cylindrical body 31 are clamped together by a fixing member 70 straddling them and fastened with a bolt 73 and a nut 74.

[0090] Regarding the insertion of the cylindrical bodies 30 together, the bolts 61 and nuts 62 used to connect the exterior wall members 50 together may be temporarily tightened, and after inserting the cylindrical bodies 30 together, the bolts 65 and nuts 66 at the connection point between the cylindrical bodies 30 and the bolts 61 and nuts 6 at the connection point between the exterior wall members 50 may be fully tightened.

[0091] [Top connection process] Figure 11 is a perspective view showing the state in which the upper lid 12 and lower hopper 14 are attached to the tank body 10. As shown in Figure 11, the upper lid 12 has an upper lid main body 121 and an upper connecting part 123. The upper lid main body 121 has a circular planar shape. The upper connecting part 123 is the part that connects to the upper part of the tank body 10. The upper connecting part 123 is formed facing downward with respect to the peripheral edge of the upper lid main body 121. The shape of the upper connecting part 123 is circular in plan view. An upper lid connecting hole 125 is formed in the upper connecting part 123 at a position corresponding to the upper connecting hole 57 provided in the outer wall member 50 that constitutes the tank body 10.

[0092] The upper lid portion 12 is connected by inserting the upper connecting portion 123 into the upper opening of the tank body 10 (the upper opening 311 of the first cylindrical body 31). The length of the outer surface of the upper connecting portion 123 is set to a length that allows it to be inserted into the upper opening 311 of the first cylindrical body 31. After the upper connecting portion 123 is inserted, the upper lid portion 12 is attached to the tank body 10 using bolts and nuts.

[0093] [Lower connection process] As shown in Figure 11, the lower hopper 14 has a lower hopper body 141 and a lower connecting portion 143. The lower hopper body 141 has a circular planar shape. The lower connecting portion 143 is the part that connects to the lower part of the tank body 10. The lower connecting portion 143 is formed upward at the periphery of the lower hopper body 141. The lower connecting portion 143 has a lower hopper connecting hole 145 formed at a position corresponding to the lower connecting hole 58 provided in the outer wall member 50 that constitutes the tank body 10.

[0094] The lower hopper 14 is connected by inserting the end of the lower hopper 14 on the side of the lower opening (lower opening 322 of the second cylindrical body 32) of the tank body 10 into the inside of the lower connecting portion 143. The length of the inner circumference of the lower connecting portion 143 is set to allow the end of the second cylindrical body 32 on the side of the lower opening 322 to be inserted. After being inserted into the lower connecting portion 143, the lower hopper 14 is attached to the tank body 10 using bolts and nuts.

[0095] Furthermore, sealing may be performed as the final step of assembly. The assembly of the cylindrical granular storage tank 100 is completed by sealing the joints of the cylindrical body 30 and the joints of the lower hopper 14 with a sealing agent to prevent leakage of dust generated from the contents.

[0096] According to the granular storage tank 100 of this embodiment described above, the tank body is composed of one or more cylindrical bodies 30, and the cylindrical bodies 30 are connected at their ends in the circumferential direction and are composed of one or more outer wall members 50 that are curved in an arc shape in the circumferential direction by elastic deformation. Therefore, the diameter and length of the tank body 10 can be easily changed by changing the number of cylindrical bodies 30 arranged in the vertical direction and the number of outer wall members 50 that make up the cylindrical bodies 30. Furthermore, since the exterior wall member 50 is formed from a thin plate that can be elastically deformed to curve in an arc shape, material costs and processing costs can be reduced, and it is also highly convenient because it can be stacked and transported and stored from the processing plant to the installation site. Furthermore, because the exterior wall component 50 is thin and lightweight, it can be easily assembled at the installation site.

[0097] Since the exterior wall members 50 are formed from thin, plate-like bodies that can be deformed to curve, there is no difficulty in finishing them to curve according to the diameter of the body, and material and processing costs can be suppressed. Furthermore, the exterior wall members 50 can be unfolded and stacked almost flat to transport and store in a small volume from the processing plant to the installation site, so there is no waste like transporting air as in conventional tank transport, and assembly and disassembly can be done by simply operating connecting members such as bolts, making it highly convenient.

[0098] Because the outer wall members 50 are lightweight, assembly at the installation site is easy. Furthermore, the lowest end of the tank body 10, which is made up of multiple outer wall members 50, is combined with the upper end (lower connecting part 143) of the nearly circular conical lower hopper 14, or with a flat lower base plate (which is mechanically removed by providing a hatch on the bottom or side), so that they naturally become nearly circular. Also, the circularity of the body, which is made up of multiple layers, naturally becomes a perfect circle when the contents are filled in, so the most difficult part of manufacturing, which is to make it perfectly circular, is completely unnecessary.

[0099] Furthermore, according to the granular storage tank 100 and the assembly method of the granular storage tank according to this embodiment, the side connecting portion 54 arranged vertically on the side surface of the tank body 10 acts as a reinforcing rib, the connecting flange portion acts as a reinforcing rib, and the connection between the cylindrical bodies 30 is made by insertion, which makes it easy to achieve a perfect circle and is strong against load, as well as making the components lighter and simpler, and there are no gaps in the connecting portion of the cylindrical bodies 30 that could cause contents to remain or insects to breed.

[0100] The plate-like material constituting the outer wall member 50 is extremely thin, making it flexible. When extending the length of the cylindrical granular storage tank 100, the cylindrical bodies 30 can be connected by inserting them together. In the conventional method, when cylindrical bodies are joined with flanges, it is difficult to form a true cylinder, and the thickness of the steel plate constituting the outer wall must be increased to withstand the load and uneven load of the cylinder. However, in this embodiment, when cylindrical bodies 30 are connected by inserting them together, it is easy to form cylindrical bodies 30 with a true circular cross-section. This is equivalent to the outer wall member 50 being formed from a single arc-shaped plate, preventing uneven loads. In other words, just as an inflated balloon does not burst, the force is evenly distributed across the tank body 10 of the granular storage tank 100.

[0101] The side connecting portion 54 not only acts as a reinforcing rib, but its cylindrical shape naturally provides greater structural strength than a flat surface. Combined with this, sufficient rigidity can be obtained even if the steel plate constituting the outer wall member 50 is extremely thin.

[0102] The force exerted on the outside of the tank body 10 by the contents can mitigate the shear force caused by the load on the cylindrical bodies 30 acting at the connection points between them and the downward load caused by the contents, which also provides the convenience of requiring fewer fastening points at the connection points when assembling the tank body 10 of the granular storage tank 100.

[0103] Furthermore, the cylindrical granular storage tank 100, by adopting a cylindrical shape, is symmetrical from any angle when viewed from above, and there are no so-called "corners" where the contents can get trapped and remain. As a result, the stored grains are supplied to the next process in a first-in, first-out manner when the contents are removed, in the order they are put into the tank, and no grains remain as residue.

[0104] [Embodiment 2] Next, a granular material storage tank 100A according to Embodiment 2 will be described. Figure 12 is a front view of the outer wall member 150 that constitutes the granular material storage tank 100A according to Embodiment 2 of the present invention.

[0105] In Embodiment 1, the side connecting portions 54, which are located at both ends of the outer wall member 50, are arranged in parallel. By changing the thickness of the spacer 64 interposed between the side connecting portions 54 when assembling the cylindrical body 30, the lengths of the inner and outer circumferential surfaces of the upper opening 311 and lower opening 312 of the first cylindrical body 31 are adjusted.

[0106] Embodiment 2 differs from the granular storage tank 100 of Embodiment 1 in that the lengths of the inner and outer circumferential surfaces of the upper opening 311 and lower opening 312 of the first cylindrical body 31 are adjusted by making the side connecting portions 154, which are located at both ends of the outer wall member 150, non-parallel. The differences from the granular storage tank 100 of Embodiment 1 will be described below.

[0107] As shown in Figure 12, the side connecting portion 154 is a flange-shaped member positioned at both ends in the circumferential direction of the outer wall body 152. Similar to Embodiment 1, the side connecting portion 154 is formed integrally with the outer wall body 152 by bending a steel plate. The side connecting portion 154 is provided to connect the ends of the outer wall members 150. A reinforcing member 56 is attached to the side connecting portion 154. The reinforcing member 56 is attached to the outer wall body 152, for example, by spot welding. As the reinforcing member 56, for example, a steel material with an L-shaped cross-section can be used (see Figure 3).

[0108] The length of both ends of the exterior wall member 150 is formed such that the lower end L3 is slightly shorter than the upper end L2. Therefore, when the exterior wall member 150 is assembled into a cylindrical body, the diameter of the lower end is slightly smaller than the diameter of the upper end of the cylindrical body. As a result, even if the lower end of the cylindrical body stacked on top is inserted inside the upper end of the cylindrical body below, the bulge caused by the thickness of the exterior wall member can be compensated for.

[0109] In this way, by forming the side connecting portions 154 at both ends to be non-parallel and assigning a relative size relationship between the gap L2 at the upper end and the gap L3 at the lower end, the same effect as changing the thickness of the spacer 64 described in Embodiment 1 can be obtained.

[0110] In this embodiment, the exterior wall member 150 is made of a thin steel plate. Therefore, the relationship between the upper end spacing L2 and the lower end spacing L3 that needs to be provided in order to insert the lower end of the first cylindrical body 31 (the end on the lower opening 312 side) into the upper opening 321 of the second cylindrical body 32 is very small. For this reason, the relationship between the upper end spacing L2 and the lower end spacing L3 may be provided for all exterior wall members used in the assembly of the first cylindrical body 31 and the second cylindrical body 32, or it may be provided for only some of the exterior wall members.

[0111] In this embodiment, the lower L3 is formed to be slightly shorter than the upper L2. Therefore, when the outer wall member 150 is assembled into a cylindrical body, the diameter of the lower end of the cylindrical body is slightly smaller than the diameter of the upper end, resulting in a tapered shape. In this case, the lower end of the upper cylindrical body is inserted into the inside of the upper end of the lower cylindrical body to connect them. Alternatively, multiple cylindrical bodies can be connected by inserting the upper end of the lower cylindrical body into the inside of the lower end of the upper cylindrical body. In this case, when the outer wall member 150 is assembled into a cylindrical body, the diameter of the upper end of the cylindrical body must be slightly smaller than the diameter of the lower end, resulting in a tapered shape. To assemble the cylindrical body in this way, the outer wall member 150 of this embodiment can be used upside down. By using it upside down, the upper side (L3) becomes slightly shorter than the lower side (L2). By using the exterior wall member 150 upside down in this way, it becomes possible to connect the upper and lower cylindrical bodies using the same exterior wall member 150 in two ways: by inserting the lower end of the upper cylindrical body into the inside of the upper end of the lower cylindrical body, or by inserting the upper end of the lower cylindrical body into the inside of the lower end of the upper cylindrical body.

[0112] [Embodiment 3] Next, the granular material storage tank 100B according to Embodiment 3 will be described. Figure 13 is a perspective view showing the state in which the upper lid portion 12B is attached to the tank body 10 of the granular material storage tank 100B according to Embodiment 3. Embodiment 3 differs from Embodiment 1 in that the upper part of the tank body 10 is closed by the upper lid portion 12B which has a substantially frustoconical outer shape. The differences from the granular material storage tank 100 of Embodiment 1 will be described below.

[0113] As shown in Figure 13, the upper lid portion 12B has an upper lid main body 121B and an upper connecting portion 123. The upper lid main body 121B is formed by an inclined surface 122B having a predetermined inclination angle with respect to the horizontal plane. The upper lid main body 121B is formed in a circular shape in plan view. A granular material input opening 13B is provided in the center of the upper lid main body 121B. Therefore, the outer shape of the upper lid main body 121B is approximately a frustoconical shape.

[0114] The granular material inlet 13B also serves as a manhole, providing access for workers to perform maintenance inside the tank body 10. A flange 131B is formed around the granular material inlet 13B. For example, a chute pipe 19 from an elevator that transports granular PG is connected to the granular material inlet 13B and flange 131B (see Figure 14). The granular PG supplied from the chute pipe 19 is fed into the tank body 10 via the granular material inlet 13B.

[0115] Figure 14 is a cross-sectional view showing the inclination angle θ1 of the inclined surface 122B of the upper lid portion 12B and the angle of repose θ2 of the granular PG stored in the granular storage tank 100B. Figure 15 is a cross-sectional view showing the movement of the surface of the granular PG when the granular PG stored in the granular storage tank 100B is discharged. As shown in Figure 14, the granular PG supplied from the chute piping 19 is stored inside the tank body 10. In this case, the upper part of the granular PG accumulates in a mountain-like shape so that the angle of the inclined surface with respect to the horizontal plane has a predetermined inclination angle (angle of repose) θ2. The angle of repose θ2 varies depending on the type and size of the granular PG, but for example, if the granular PG is rice, the angle of repose θ2 is 33 to 34 degrees.

[0116] The angle θ1 of the inclined surface 122B of the upper lid portion 12B is set to correspond to the angle of repose θ2 of the granular PG. For example, it is preferable that the angle θ1 of the inclined surface 122B be set to be about 1 to 5 degrees greater than the angle of repose θ2 of the granular PG. For example, in this embodiment, since the angle of repose θ2 of the granular PG (rice) is 33 to 34 degrees, the inclination angle θ1 of the inclined surface 122B is set to 36 degrees.

[0117] In this case, as in Embodiment 1, when a flat upper lid 12 is provided on the top of the tank body 10, a space is created between the granular PG accumulated in a curved shape according to the angle of repose θ2 and the flat upper lid 12. Since granular PG cannot be accumulated in this space, the space is wasted, and the steel plate of the tank body 10 that forms the part where granular PG cannot be accumulated is also wasted. In addition, granular PG dust may accumulate in the part where granular PG cannot be accumulated, which may make it easier for pests to breed inside the tank body 10.

[0118] In contrast, as in this third embodiment, by setting the inclination angle θ1 of the inclined surface 122B of the upper lid portion 12B to an angle corresponding to the accumulation shape of the granular PG (angle of repose θ2), a space is less likely to form between the granular PG and the upper lid portion 12B, as shown in Figure 15. This reduces wasted space and also reduces wasted steel plates that make up the tank body 10.

[0119] Furthermore, in this embodiment 3, the inclination angle θ1 of the inclined surface 122B of the upper lid 12B is set to be slightly larger than the angle of repose θ2 of the granular PG. This creates an effect where, when the granular PG is removed, the granular PG moves while rubbing against the inner surface of the inclined surface 122B of the upper lid 12. Specifically, as shown in Figure 15, the surface S1 of the granular PG indicates that the granular PG has accumulated up to the top of the tank body 10. When the removal of granular PG from the lower hopper 14 of the tank body 10 begins in this state, the position of the surface of the granular PG gradually moves downward as S1, S2, S3, S4, etc., while maintaining the angle of repose θ2. In this case, at the point of contact between the inclined surface 122B of the upper lid 12B and the surface of the granular PG, the granular PG moves while rubbing against the inner surface of the inclined surface 122B. As a result, the granular PG moves while drawing in and removing dust from the inner surface of the inclined surface 122B, thus performing a cleaning function on the inner surface of the inclined surface 122B. Therefore, the accumulation of dust inside the tank body 10 can be suppressed, and the effect of making it difficult for pests to breed inside the tank body 10 is achieved.

[0120] [Differentiation] The granular material storage tank according to the present invention is not limited to the embodiment described above. For example, the shape and dimensions of the main body are not limited to the shape of this embodiment.

[0121] In this embodiment, the outer wall member 50 constituting the tank body 10 has a constant thickness, but is not limited to this. For example, the thickness of the outer wall body 52 of the outer wall member 50 constituting the lowest cylindrical body 30 may be thicker than the thickness of the outer wall body 52 of the outer wall members 50 constituting the other cylindrical bodies 30. In this case, the strength of the lowest cylindrical body 30, which is subjected to particularly large loads, can be improved, and the strength of the tank body 10 can be improved.

[0122] In this embodiment, the exterior wall body 52 and the side connecting portion 54 of the exterior wall member 50 are formed integrally by bending both ends of a steel plate, but the embodiment is not limited to this. For example, the exterior wall body and the side connecting portion may be made as separate parts, the side connecting portion may be formed from an angle (L-shaped steel material), and the side connecting portion may be attached to the end of the flat exterior wall body by means of spot welding or other means. In this case, depending on the required strength and other conditions, the reinforcing material 56 described in the embodiment may be omitted.

[0123] The exterior wall member 50 may be configured to incorporate other parts as needed. For example, it may be provided with a mounting section for a sensor to detect the presence or absence of contents.

[0124] Examples of upper components include the upper lid 12 and the upper lid 12B, and examples of lower components include the lower hopper 14 and the lower base plate; however, the structure, shape, material, etc., of these components are not particularly limited.

[0125] Although embodiments of the present invention have been described above, the embodiments described above are merely illustrative examples for carrying out the present invention. Therefore, the present invention is not limited to the embodiments described above, and it is possible to carry out the present invention by appropriately modifying the embodiments described above without departing from the spirit of the invention. [Explanation of Symbols]

[0126] 100 granular material storage tank 10 Tank body 30 Cylinder 31 First cylinder 32 Second cylinder 50 Exterior wall components

Claims

1. A granular material storage tank having a cylindrical tank body, The tank body is Each has an upper opening and a lower opening, and is composed of multiple cylindrical bodies arranged in the vertical direction. The aforementioned cylindrical body is It is composed of multiple outer wall members, each with its ends connected in the circumferential direction and curved in an arc shape in the circumferential direction by elastic deformation. In a pair of vertically adjacent cylindrical bodies, the upper opening of the lower cylindrical body and the end of the lower opening of the upper cylindrical body are connected by being inserted into each other. The aforementioned exterior wall member is The outer wall body is formed of a plate-like body that is elastically deformable so as to be curved in an arc shape in the circumferential direction of the cylindrical body, The cylindrical body has side connecting portions arranged at both ends of the outer wall body in the circumferential direction, which connect the ends of the outer wall members together. It has, The aforementioned side connecting portion is The ends of adjacent exterior wall members are connected so that adjacent exterior wall body parts do not overlap, and the side connecting parts are positioned at a predetermined distance from the upper or lower end of the cylindrical body so that when a pair of vertically adjacent cylindrical bodies are connected by insertion, the side connecting parts do not interfere with other cylindrical bodies. Granular material storage tank.

2. The tank body is equipped with a lower member connected to the lower part, The lower member is formed as an inverted cone-shaped hopper or as a member with a circular top surface, and is connected to the lower part of the tank body. The lower end of the tank body and the upper end of the lower member are connected by being inserted into each other. A granular material storage tank according to claim 1.

3. In a pair of cylindrical bodies connected vertically, the length of the inner circumference of the upper opening of the lower cylindrical body is made longer than the length of the outer circumference of the lower opening of the upper cylindrical body, or the length of the outer circumference of the upper opening of the lower cylindrical body is made shorter than the length of the inner circumference of the lower opening of the upper cylindrical body. A granular material storage tank according to claim 1.

4. The device further includes a fixing member for fixing the side connecting portion provided on the outer wall member constituting one of the vertically adjacent cylindrical bodies, and the side connecting portion provided on the outer wall member constituting the other cylindrical body. A granular material storage tank according to any one of claims 1 to 3.

5. A method for assembling a granular storage tank according to Claim 2, The tank body is composed of multiple cylindrical bodies, The multiple outer wall members constituting the cylindrical body are connectable at their ends in the circumferential direction of the tank body, and are also capable of bending in an arc shape in the circumferential direction by elastic deformation. A cylindrical assembly step in which multiple outer wall members are elastically deformed in the circumferential direction, the ends of the outer wall members are connected to form a cylindrical body, and the tank body is formed by multiple cylindrical bodies, A lower connection step involves connecting the inverted cone-shaped hopper, or the lower member having a circular top surface, to the lower part of the tank body by insertion, A method for assembling a granular storage tank containing [a specific material].

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