Transportation switching device, transportation system, and transportation switching method

Abstract

To provide technology capable of realizing switching of a transportation route on which particulate matter is transported from one selected from multiple transportation sources to one selected from multiple transportation destinations, at low cost.SOLUTION: A transportation switching device switches a transportation route in a transportation system 1 of transporting particulate matter from a selected transportation source to a selected transportation destination. A transportation piping 30 forming the transportation route has: one spiral common pipe 31; multiple inflow side branched pipes 32a, 32b branched from the common pipe 31 and connected to one of the multiple transportation sources; multiple inflow side on-off valves 33a, 33b for switching the communication of the multiple inflow side branched pipes 32a, 32b with the common pipe 31; multiple outflow side branched pipes 34a, 34b branched from the common pipe 31 and connected to one of the multiple transportation destinations; and multiple outflow side on-off valved 35a, 35b for switching the communication of the multiple outflow side branched pipes 34a, 34b with the common pipe 31.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a transportation system that transports powder or granular materials (hereinafter referred to as "powder and granular materials") from one selected source among multiple sources to one selected destination among multiple destinations, and to a transportation switching device and transportation switching method that switch transportation routes connecting the multiple sources and the multiple destinations, as well as the transportation system. [Background technology]

[0002] Conventionally, in the manufacturing process of plastic products, raw materials are transported from one of a number of raw material tanks or the like storing various raw materials to a destination such as an injection molding machine while switching the transport route. Such a transport route switching device is disclosed in, for example, Patent Document 1 and Patent Document 2. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 09-086658 [Patent Document 2] Japanese Utility Model Application Publication No. 62-038221 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 relates to a piping switching device used when transporting various raw materials to a molding machine. The piping switching device of Patent Document 1 switches between a first transport pipe (2) and multiple second transport pipes (5) via a curved switching pipe (4). Specifically, one end of the switching pipe (4) is connected to the first transport pipe (2), and the other end of the switching pipe (4) is rotatable in the circumferential direction around the connection point with the first transport pipe (2). Furthermore, multiple second transport pipes (5) are arranged on a circumferential movement path described by the rotation of the other end of the switching pipe (4). Furthermore, the other end of the switching pipe (4) and the second transport pipe (5) are detachable using a connecting tube (6) and a biasing means (7) (paragraph 0006, Figure 1). Furthermore, by connecting two piping switching devices to each other on the side of their respective first transport pipes (2), a configuration is created in which raw materials are transported from multiple second transport pipes (5) to multiple second transport pipes (5), and various raw materials can also be transported from multiple raw material tanks (T) to multiple molding machines (M) (paragraph 0021, Figure 7-8).

[0005] Patent Document 2 relates to a switch used to distribute powder such as grains to multiple storage tanks. The main body (1) of the switch (A) in Patent Document 2 is horn-shaped and has a small-diameter opening (3) on one side that is narrowed and a large-diameter opening (5) on the other side that is concentrically arranged. A switch pipe (7) is rotatably housed within the main body (1). One end of the switch pipe (7) is provided with a receiving port (9) that matches the small-diameter opening (3), and the other end is provided with a disk (11) that can be loosely fitted into the large-diameter opening (5). An eccentric distribution port (15) that communicates with the receiving port (9) is provided at a portion of the circumference of the disk (11) (page 4, line 19 - page 6, line 2, Figures 1-2). The switching pipe (7) is rotatably operated in a desired circumferential direction by an operating shaft (49), thereby switching the connection mode of the eccentric distribution port (15) to the two switching ports (37, 39) (page 7, line 11 - page 8, line 9). When distributing powder into a plurality of storage tanks (73, 75), one end of a supply pipe (67) connected to a hopper (63) with a blower (65) at one end is screwed to one side of the switch (A), and one end of distribution pipes (69, 71) extending from the storage tanks (73, 75) is screwed to the switching ports (37, 39), thereby enabling distribution of powder by switching (page 9, line 9 - page 10, line 6, Figure 3).

[0006] However, the devices disclosed in Patent Documents 1 and 2 have a configuration in which the transport path is switched by moving part of the pipe that transports the powder and granular material, and therefore there is a risk that costs will increase in order to increase the accuracy of switching the transport path.

[0007] The present invention aims to provide an apparatus and method that can switch a transport route to transport powder or granular material from one selected from multiple sources to one selected from multiple destinations at low cost. [Means for solving the problem]

[0008] In order to solve the above problems, the first invention of the present application relates to a transportation system for transporting powder or granular material from a selected one of a plurality of transportation sources to a selected one of a plurality of transportation destinations, and relates to a transportation switching device that switches a transportation route connecting the multiple transportation sources and the multiple transportation destinations. The transportation switching device includes a transportation pipe that constitutes the transportation route. The transportation pipe has one common pipe, two outside air introduction valves, multiple inlet branch pipes, multiple inlet on-off valves, multiple outlet branch pipes, and multiple outlet on-off valves. The two outside air introduction valves are provided at both ends of the common pipe, and each allows the end of the common pipe to be open to outside air. The multiple inlet branch pipes branch from multiple positions spaced apart from each other on the common pipe, and each is connected to one of the multiple transportation sources. The multiple inlet on-off valves switch communication between each of the multiple inlet branch pipes and the common pipe. The plurality of outlet branch pipes branch off from the common pipe at a plurality of positions spaced apart from one another and are connected to one of the plurality of transport destinations, and the plurality of outlet on-off valves switch communication between each of the plurality of outlet branch pipes and the common pipe.

[0009] A second invention of the present application is the transportation switching device of the first invention, wherein the common pipe is formed in a spiral shape and supported by a support member.

[0010] The third invention of the present application is a transportation system having a transportation switching device of the first or second invention, the multiple transportation sources, the multiple transportation destinations, and an airflow generating means for generating an airflow within the transportation pipeline from the transportation sources to the transportation destinations.

[0011] A fourth invention of the present application is a transportation system according to the third invention, wherein each of the plurality of inlet-side opening / closing valves comprises a casing having an upstream end provided with an upstream opening to which the inlet-side branch pipe is directly or indirectly connected, and a downstream end provided with a downstream opening to which the common pipe is directly or indirectly connected; a valve body for opening and closing the upstream opening; and an air cylinder for moving the valve body back and forth in a direction perpendicular to the upstream opening, wherein when the valve body opens the upstream opening by actuation of the air cylinder, powder or granular material flows into the casing and flows out from the downstream opening, and when the valve body closes the upstream opening by actuation of the air cylinder, the flow of powder or granular material into the casing is stopped.

[0012] The fifth invention of the present application is a transportation system of the third invention, wherein each of the plurality of outlet-side opening / closing valves comprises a casing having an upstream end provided with an upstream opening to which the common pipe is directly or indirectly connected, and a downstream end provided with a downstream opening to which the outlet-side branch pipe is directly or indirectly connected, a valve body for opening and closing the upstream opening, and an air cylinder for moving the valve body back and forth in a direction perpendicular to the upstream opening, wherein when the valve body opens the upstream opening by driving the air cylinder, powder and granular material flows into the casing and flows out from the downstream opening, and when the valve body closes the upstream opening by driving the air cylinder, the flow of powder and granular material into the casing is stopped.

[0013] A sixth invention of the present application is a transportation system according to any one of the third to fifth inventions, wherein the airflow generating means generates an airflow within the transportation pipeline from the source to the destination by drawing in air from the selected one of the destinations.

[0014] A seventh invention of the present application relates to a transportation switching method for switching a transportation path connecting multiple transportation sources and multiple transportation destinations in a transportation process in which powder or granular material is transported from a selected one of multiple transportation sources to a selected one of multiple transportation destinations. The transportation piping constituting the transportation path includes a common pipe, two outside air introduction valves, multiple inlet branch pipes, multiple inlet on-off valves, multiple outlet branch pipes, and multiple outlet on-off valves. The two outside air introduction valves are provided at both ends of the common pipe, each opening the end of the common pipe to outside air. The multiple inlet branch pipes branch from multiple positions spaced apart from each other and are each connected to one of the multiple transportation sources. The multiple inlet on-off valves switch communication between each of the multiple inlet branch pipes and the common pipe. The multiple outlet branch pipes branch from multiple positions spaced apart from each other from the common pipe and are each connected to one of the multiple transportation destinations. The plurality of outlet-side on-off valves switch communication between each of the plurality of outlet-side branch pipes and the common pipe. The method also includes the steps of: (a) opening the inlet-side on-off valve to communicate the inlet-side branch pipe connected to the selected one transport source with the common pipe; (b) opening the outlet-side on-off valve to communicate the outlet-side branch pipe connected to the selected one transport destination with the common pipe; and (c) sucking air from the selected one transport destination, thereby transporting powder or granular material from the transport source to the transport destination. The step (a) is performed while switching the two outside air introduction valves, one of which is provided at one end of the common pipe downstream in the transport direction of the powder or granular material, from a closed state to an open state.

[0015] The eighth invention of the present application is a transport switching method according to the seventh invention, in which step a) is carried out by switching multiple times between a state in which the two outside air introduction valves are each closed and a state in which the outside air introduction valve provided at the downstream end of the common pipe, as viewed in the transport direction of the powder or granular material, is opened.

[0016] The ninth invention of the present application is a transport switching method according to the seventh or eighth invention, further comprising the step of: b) after step a), blocking communication between the inlet branch pipe connected to the selected one transport source and the common pipe by closing the inlet side opening / closing valve, and transporting the powder or granular material remaining in the transport pipe to the selected one transport destination by sucking air from the selected one transport destination, and step b) is performed with at least one of the two outside air intake valves open.

[0017] A tenth aspect of the present invention is the transportation switching method of the ninth aspect, wherein the step b) is first performed with the two outside air introduction valves both open.

[0018] An eleventh invention of the present application is a transportation switching method according to the tenth invention, in which step b) is performed by opening each of the two outside air introduction valves, and then switching multiple times between a state in which only the outside air introduction valve provided at the downstream end of the common pipe, as viewed in the transport direction of the powder or granular material, is opened, and a state in which only the outside air introduction valve provided at the upstream end of the common pipe, as viewed in the transport direction of the powder or granular material, is opened. [Effects of the Invention]

[0019] According to the first to eleventh inventions of the present application, it is possible to switch transport routes from multiple sources to multiple destinations at low cost using a simple structure. Furthermore, even if the powder or granular material overruns in the common pipe during transport, the powder or granular material can be returned by air introduced through the outside air inlet valve and transported to the destination.

[0020] In particular, according to the second aspect of the present invention, by forming the common pipe into a spiral shape, it is possible to reduce the space required for arranging the transportation piping including the common pipe.

[0021] In particular, according to the fourth aspect of the present invention, the inlet side on-off valve can be configured at low cost with a simple structure.

[0022] In particular, according to the fifth aspect of the present invention, the outlet side on-off valve can be configured at low cost with a simple structure.

[0023] In particular, according to the sixth aspect of the present invention, an airflow that flows from the transport source to the transport destination can be generated with a simple structure and at low cost.

[0024] In particular, according to the eighth invention of the present application, by repeating a process of transporting powder or granular material mainly from the source to the destination while closing two outside air introduction valves provided at both ends of the common pipe, and a process of returning the overrun of powder or granular material in the common pipe by opening the outside air introduction valve provided at the downstream end of both ends of the common pipe as seen in the transport direction of the powder or granular material in the common pipe, it is possible to transport the powder or granular material while suppressing the amount of powder or granular material remaining in the transport pipe.

[0025] In particular, according to the ninth, tenth, and eleventh inventions of the present application, when returning overrun powder or granular material in a common pipe, even if the powder or granular material returns too far upstream in the transport direction, the powder or granular material can be advanced downstream again and transported to the destination. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a diagram conceptually illustrating the configuration of a transportation system. [Figure 2] FIG. [Figure 3] FIG. 2 is a vertical cross-sectional view of an inlet-side on-off valve. [Figure 4] FIG. 2 is a vertical cross-sectional view of an outlet-side on-off valve. [Figure 5] FIG. 2 is a block diagram showing connections between a control unit and each unit. [Figure 6] 1 is a flowchart showing the flow of a powder / granular material transport process. [Figure 7] FIG. 1 is a schematic diagram for illustrating a powder / granular material transport process. [Figure 8] 1 is a time chart showing the flow of a powder / granular material transport process. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0028] <1. Transport system configuration> 1 is a conceptual diagram illustrating the configuration of a transportation system 1 according to one embodiment of the present invention. This transportation system 1 is a system that transports powder and granular materials, including, for example, resin pellets that are raw materials for resin molded products such as plastics, from a source to a destination. In particular, the transportation system 1 of this embodiment transports powder and granular materials from one selected from multiple sources to one selected from multiple destinations in a plastic product manufacturing process.

[0029] 1, the transportation system 1 of this embodiment includes a plurality of (two in this embodiment) first hoppers 10a, 10b that are the transportation source, a plurality of (two in this embodiment) second hoppers 20a, 20b that are the transportation destination, a transportation pipe 30, a plurality of (two in this embodiment) exhaust pipes 40a, 40b, a plurality of (two in this embodiment) blowers 50a, 50b, and a control unit 60. However, the number of first hoppers 10a, 10b and the number of second hoppers 20a, 20b included in the transportation system 1 may each be one, three or more.

[0030] The first hoppers 10a and 10b are containers that store powder and granular material before transportation. The first hoppers 10a and 10b are an example of a transportation source in the present invention. In this embodiment, different types of powder and granular material are stored in the two first hoppers 10a and 10b. For example, one of the first hoppers 10a stores resin pellets, which are the main raw material of resin molded products, and the other first hopper 10b stores crushed recycled material. However, in addition to these, the multiple first hoppers may store powder and granular material such as masterbatches or additives used as colorants for coloring resin molded products.

[0031] In this embodiment, the two first hoppers 10a, 10b have the same structure. Each of the first hoppers 10a, 10b has a substantially cylindrical sidewall 11, a funnel-shaped bottom 12 that gradually converges downward from the lower end of the sidewall 11, and a top plate 13 that covers the upper portion. A space for storing powdered or granular material is provided inside the first hoppers 10a, 10b. A first discharge port 14 is provided at the center of each bottom 12 for discharging powdered or granular material from the first hoppers 10a, 10b to the transport pipe 30. The first hoppers 10a, 10b may have other shapes. For example, the sidewall 11 may be a rectangular cylindrical shape. The multiple first hoppers included in the transport system 1 may have different structures.

[0032] Further, an on-off valve 16 and an on-off mechanism 17 connected to the on-off valve 16 are attached to each first discharge port 14. The on-off mechanism 17 operates an air cylinder in response to a command from the control unit 60 to move a valve element back and forth, thereby opening and closing the on-off valve 16. However, instead of the on-off valve 16 and the on-off mechanism 17, a manual valve that can be opened and closed manually may be attached to each first discharge port 14.

[0033] Above the first hoppers 10a, 10b, devices (upstream devices) that supply powdered or granular material to the first hoppers 10a, 10b are arranged. Each upstream device supplies a predetermined type of powdered or granular material to the first hoppers 10a, 10b. Therefore, the types of powdered or granular material supplied from the upstream devices above the two first hoppers 10a, 10b are different from each other. Each upstream device can replenish powdered or granular material in response to a replenishment request when the powdered or granular material in the first hoppers 10a, 10b becomes low. However, each upstream device may measure multiple types of powdered or granular material to achieve a predetermined mixing ratio and supply them to the first hoppers 10a, 10b. Furthermore, the first hoppers 10a, 10b do not necessarily have to be connected to the upstream devices. For example, an operator may manually add powdered or granular material to the first hoppers 10a, 10b.

[0034] The second hoppers 20a, 20b are containers that temporarily store powdered or granular material transported from the first hoppers 10a, 10b via the transport pipe 30. The second hoppers 20a, 20b are an example of a transport destination in the present invention. In this embodiment, the two second hoppers 20a, 20b have the same structure. Each of the second hoppers 20a, 20b has a substantially cylindrical side wall 21, a funnel-shaped bottom 22 that gradually converges downward from the lower end of the side wall 21, and a top plate 23 that covers the upper part. A space for temporarily storing powdered or granular material is provided inside the second hoppers 20a, 20b. The second hoppers 20a, 20b may have other shapes. For example, the side wall 21 may be a rectangular cylindrical shape. The multiple second hoppers included in the transport system 1 may have different structures.

[0035] Each side wall 21 is provided with an inlet 24 for receiving powdered or granular material. A second outlet 25 for discharging powdered or granular material from the second hoppers 20a, 20b is provided in the center of each bottom portion 22. Each top plate portion 23 is provided with an exhaust port 26 for sucking air out of the second hoppers 20a, 20b.

[0036] Each second discharge port 25 is provided with a discharge valve 27 that controls the opening and closing of the second discharge port 25. The discharge valve 27 may, for example, be a mechanism that operates an air cylinder to move a valve element back and forth in response to a command from the control unit 60. However, the discharge valve 27 does not have to be a mechanism that moves a valve element back and forth using an air cylinder or the like. For example, the discharge valve 27 may be a plate-shaped valve disposed at an appropriate distance from the end of the second discharge port 25, which automatically moves to close the second discharge port 25 when the blowers 50a, 50b are activated to reduce the pressure inside the second hoppers 20a, 20b. Instead of the discharge valve 27, each second discharge port 25 may be provided with a manual valve that can be manually opened and closed. A device (downstream device 29) that receives the powder and granular material discharged from each second discharge port 25 is disposed below the second hoppers 20a, 20b. The downstream device 29 may, for example, be an injection molding machine. When the second discharge port 25 is opened, the powder and granular material in the second hoppers 20a and 20b is discharged to the downstream device 29 through the second discharge port 25, respectively.

[0037] The transport pipe 30 connects the first hoppers 10a, 10b and the second hoppers 20a, 20b. The transport pipe 30 constitutes a transport path connecting the multiple (two in this embodiment) first hoppers 10a, 10b and the multiple (two in this embodiment) second hoppers 20a, 20b. As shown in FIG. 1 , the transport pipe 30 includes one common pipe 31, multiple (two in this embodiment) inlet branch pipes 32a, 32b, multiple (two in this embodiment) inlet on-off valves 33a, 33b, multiple (two in this embodiment) outlet branch pipes 34a, 34b, and multiple (two in this embodiment) outlet on-off valves 35a, 35b. The common pipe 31, the two inlet branch pipes 32a, 32b, and the two outlet branch pipes 34a, 34b are each made of, for example, a metal circular pipe.

[0038] The common pipe 31 is a pipe formed in a spiral shape. In this embodiment, by forming the common pipe 31 in a spiral shape, the space required for arranging the transport pipe 30 including the common pipe 31 can be reduced. In this embodiment, the common pipe 31, the two inlet-side on-off valves 33a and 33b, and the two outlet-side on-off valves 35a and 35b are supported by a support member 36. FIG. 2 is a perspective view of the support member 36. In FIG. 2, the common pipe 31, the two inlet-side on-off valves 33a and 33b, and the two outlet-side on-off valves 35a and 35b are respectively illustrated by dashed lines. The support member 36 is formed, for example, by an aluminum frame. However, the structure of the support member 36 is not limited thereto.

[0039] Hereinafter, the opening at the upstream end of the common pipe 31 as viewed in the powder / granular material transport direction td will be referred to as the "outside air inlet 310a." The opening at the downstream end of the common pipe 31 as viewed in the powder / granular material transport direction td will be referred to as the "outside air inlet 310b." The outside air inlet 310a is equipped with an outside air introduction valve 311a, an opening / closing mechanism 312a connected to the outside air introduction valve 311a, and a filter 313a. The opening / closing mechanism 312a operates an air cylinder in response to commands from the control unit 60 to move the valve element back and forth, thereby opening and closing the outside air introduction valve 311a. Opening the outside air introduction valve 311a allows outside air to be introduced into the common pipe 31 via the filter 313a. Instead of the outside air introduction valve 311a and the opening / closing mechanism 312a, a manual valve that can be opened and closed manually may be installed.

[0040] Additionally, the outside air inlet 310b is equipped with an outside air introduction valve 311b, an opening / closing mechanism 312b connected to the outside air introduction valve 311b, and a filter 313b. The opening / closing mechanism 312b opens and closes the outside air introduction valve 311b by operating an air cylinder to move the valve element back and forth in response to commands from the control unit 60. When the outside air introduction valve 311b is opened, outside air can be taken into the common pipe 31 via the filter 313b. However, instead of the outside air introduction valve 311b and the opening / closing mechanism 312b, a manual valve that can be opened and closed manually may be installed. As described above, the transportation pipe 30 of this embodiment has two outside air introduction valves 311a, 311b, which are provided at both ends of the common pipe 31 and allow the ends of the common pipe 31 to be open to the outside air.

[0041] 1, the two inlet branch pipes 32a and 32b are pipes that branch off from a plurality of (two, in this embodiment) positions P1 and P2 that are spaced apart from each other in the common pipe 31. One end of the inlet branch pipe 32a is connected to the first discharge outlet 14 of the first hopper 10a, which is one of the plurality of transport sources. The inlet branch pipe 32b is connected to the first discharge outlet 14 of the first hopper 10b, which is another of the plurality of transport sources, at one end.

[0042] Each of the inlet-side branch pipes 32a and 32b has an opening 320 near the first outlet 14. A transport source valve 321, an opening / closing mechanism 322 connected to the transport source valve 321, and a filter 323 are attached to the opening 320. The opening / closing mechanism 322 opens and closes the transport source valve 321 by operating an air cylinder in response to a command from the control unit 60 to move the valve element back and forth. When the transport source valve 321 is opened, outside air can be taken into the inside of the inlet-side branch pipes 32a and 32b via the filter 323. However, instead of the transport source valve 321 and the opening / closing mechanism 322, a manual valve that can be opened and closed manually may be attached.

[0043] The multiple (two in this embodiment) inlet-side on-off valves 33a, 33b are mechanisms that switch communication between each of the multiple (two in this embodiment) inlet-side branch pipes 32a, 32b and the common pipe 31. More specifically, the inlet-side on-off valve 33a switches communication between the inlet-side branch pipe 32a and the common pipe 31. The inlet-side on-off valve 33b switches communication between the inlet-side branch pipe 32b and the common pipe 31. FIG. 3 is a vertical cross-sectional view of each of the inlet-side on-off valves 33a, 33b. As shown in FIG. 3, the inlet-side on-off valves 33a, 33b each have a casing 331, a valve element 332, and an air cylinder 333.

[0044] The casing 331 is a hollow metal frame. A circular upstream opening 710 is provided at the upstream end 71 of the casing 331. The upstream opening 710 connects the interior space of the casing 331 to the exterior space. One end of an upstream connecting pipe 72, which is a circular pipe partially made of resin, is fitted and fixed into the upstream opening 710. The other end of the upstream connecting pipe 72 is connected to the ends of the inlet branch pipes 32a and 32b. That is, in this embodiment, the inlet branch pipes 32a and 32b are indirectly connected to the upstream opening 710 via the upstream connecting pipe 72. However, the inlet branch pipes 32a and 32b may also be directly connected to the upstream opening 710.

[0045] 3, one end of the upstream connecting pipe 72 protrudes slightly into the internal space of the casing 331. This prevents the powder from getting caught and staying near the upstream opening 710 when the powder flows from the upstream connecting pipe 72 into the internal space of the casing 331, as will be described later. However, one end of the upstream connecting pipe 72 does not have to protrude into the internal space of the casing 331.

[0046] A circular downstream opening 730 is provided at the downstream end 73 of the casing 331. The downstream opening 730 connects the internal space of the casing 331 with the external space. One end of a downstream connecting pipe 74, which is a circular pipe partially made of resin, is fitted and fixed into the downstream opening 730. The common pipe 31 is connected to the other end of the downstream connecting pipe 74. That is, in this embodiment, the common pipe 31 is indirectly connected to the downstream opening 730 via the downstream connecting pipe 74. However, the common pipe 31 may also be directly connected to the downstream opening 730.

[0047] The valve element 332 is a metal member that opens and closes the upstream opening 710. The valve element 332 includes a planar contact surface 81. The contact surface 81 is substantially parallel to the upstream opening 710, and the outer diameter of the contact surface 81 is larger than the outer diameter of the upstream opening 710. As a result, the upstream opening 710 is opened and closed when the contact surface 81 comes into contact with or separates from the end of the upstream connecting pipe 72 fixed to the upstream opening 710. As described above, the valve element 332 of this embodiment is made of metal. Therefore, even if the valve element 332 is pressed against the upstream connecting pipe 72 or the powder or granular material, damage and wear of the valve element 332 are suppressed. However, the valve element 332 may be made of resin.

[0048] The air cylinder 333 is a device that moves the valve disc 332 back and forth in a direction perpendicular to the upstream opening 710. The air cylinder 333 moves the valve disc 332 back and forth in the direction of a valve disc axis 810 that passes through the center of the upstream opening 710 and is perpendicular to the upstream opening 710. The air cylinder 333 has a main body 82, a displacement rod 83, and a support mechanism 84. The air cylinder 333 generates power that displaces the displacement rod 83 along the valve disc axis 810 by supplying air to and discharging air from a push-side internal space 821 located on the push side of the displacement rod 83 within the internal space of the main body 82 and pulling air from and supplying air to a pull-side internal space 822 located on the pull side of the displacement rod 83 within the internal space of the main body 82.

[0049] The main body 82 is fixed to the casing 331 by a support mechanism 84 including a bolt and nut structure. A valve element 332 is attached to the tip of the displacement rod 83. In response to commands from the control unit 60, the air cylinder 333 supplies air to and exhausts air from the push-side internal space 821, and exhausts air from and supplies air to the pull-side internal space 822, thereby displacing the displacement rod 83 and moving the valve element 332 back and forth along the direction of the valve element axis 810.

[0050] 3, the valve element 332 faces the upstream opening 710 in the direction of the valve element axis 810. As described above, the contact surface 81 is substantially parallel to the upstream opening 710, and the outer diameter of the contact surface 81 is larger than the outer diameter of the upstream opening 710. As a result, when the valve element 332 advances toward the upstream opening 710 by driving the air cylinder 333 and the contact surface 81 comes into contact with the end of the upstream connecting pipe 72, the upstream opening 710 is closed. As a result, even when the blowers 50a and 50b (described later) are driven to generate an airflow in the transport piping 30 from a selected one of the first hoppers 10a and 10b, which are the transport sources, to a selected one of the second hoppers 20a and 20b, which are the transport destinations, the inflow of powder and granular material into the casing 331 through the upstream opening 710 is stopped.

[0051] On the other hand, when the valve element 332 is retracted from the upstream opening 710 by the actuation of the air cylinder 333 and the contact surface 81 is separated from the end of the upstream connecting pipe 72, the upstream opening 710 is opened. As a result, when the blowers 50a, 50b (described later) are actuated to generate an airflow in the transport piping 30 from a selected one of the first hoppers 10a, 10b, which are the transport sources, to a selected one of the second hoppers 20a, 20b, which are the transport destinations, the powder or granular material flows into the casing 331 through the upstream opening 710 and flows out through the downstream opening 730. In this embodiment, the inlet-side on-off valves 33a, 33b can be configured at low cost with such a simple structure.

[0052] 1, the two outlet branch pipes 34a, 34b are pipes that branch off from multiple (two, in this embodiment) positions P3, P4 spaced apart from each other in the common pipe 31. Note that positions P3, P4 are located downstream of positions P1, P2 in the transport direction td of the powder or granular material in the common pipe 31. One end of the outlet branch pipe 34a is connected to the inlet 24 of the second hopper 20a, which is one of the multiple transport destinations. One end of the outlet branch pipe 34b is connected to the inlet 24 of the second hopper 20b, which is one of the multiple transport destinations.

[0053] The multiple (two in this embodiment) outlet-side on-off valves 35a, 35b are mechanisms that switch communication between each of the multiple (two in this embodiment) outlet-side branch pipes 34a, 34b and the common pipe 31. More specifically, the outlet-side on-off valve 35a switches communication between the outlet-side branch pipe 34a and the common pipe 31. The outlet-side on-off valve 35b switches communication between the outlet-side branch pipe 34b and the common pipe 31. FIG. 4 is a vertical cross-sectional view of each of the outlet-side on-off valves 35a, 35b. As shown in FIG. 4, the outlet-side on-off valves 35a, 35b each include a casing 351, a valve element 352, and an air cylinder 353. The outlet-side on-off valves 35a, 35b have the same configuration as the inlet-side on-off valves 33a, 33b.

[0054] The casing 351 is a hollow metal frame. A circular upstream opening 710 is provided at the upstream end 71 of the casing 351. The upstream opening 710 connects the interior space of the casing 351 with the exterior space. One end of an upstream connecting pipe 72, which is a circular pipe partially made of resin, is fitted and fixed into the upstream opening 710. The other end of the upstream connecting pipe 72 is connected to the common pipe 31. That is, in this embodiment, the upstream opening 710 is indirectly connected to the common pipe 31 via the upstream connecting pipe 72. However, the upstream opening 710 may also be directly connected to the common pipe 31.

[0055] 4, one end of the upstream connecting pipe 72 protrudes slightly into the internal space of the casing 351. This prevents the powder from getting caught and staying near the upstream opening 710 when the powder flows from the upstream connecting pipe 72 into the internal space of the casing 351, as will be described later. However, one end of the upstream connecting pipe 72 does not have to protrude into the internal space of the casing 351.

[0056] A circular downstream opening 730 is provided at the downstream end 73 of the casing 351. The downstream opening 730 connects the interior space of the casing 351 with the exterior space. One end of a downstream connecting pipe 74, which is a circular pipe partially made of resin, is fitted and fixed into the downstream opening 730. The other end of the downstream connecting pipe 74 is connected to the ends of the outlet branch pipes 34a and 34b. That is, in this embodiment, the outlet branch pipes 34a and 34b are indirectly connected to the downstream opening 730 via the downstream connecting pipe 74. However, the outlet branch pipes 34a and 34b may also be directly connected to the downstream opening 730.

[0057] The valve element 352 is a metal member that opens and closes the upstream opening 710. The valve element 352 includes a planar contact surface 81. The contact surface 81 is substantially parallel to the upstream opening 710, and the outer diameter of the contact surface 81 is larger than the outer diameter of the upstream opening 710. As a result, the upstream opening 710 is opened and closed when the contact surface 81 comes into contact with or separates from the end of the upstream connecting pipe 72 fixed to the upstream opening 710. As described above, the valve element 352 of this embodiment is made of metal. Therefore, even if the valve element 352 is pressed against the upstream connecting pipe 72 or the powder or granular material, damage and wear of the valve element 352 are suppressed. However, the valve element 352 may be made of resin.

[0058] The air cylinder 353 is a device that moves the valve disc 352 back and forth in a direction perpendicular to the upstream opening 710. The air cylinder 353 moves the valve disc 352 back and forth in the direction of a valve disc axis 810 that passes through the center of the upstream opening 710 and is perpendicular to the upstream opening 710. The air cylinder 353 has a main body 82, a displacement rod 83, and a support mechanism 84. The air cylinder 353 generates power that displaces the displacement rod 83 along the valve disc axis 810 by supplying air to and discharging air from a push-side internal space 821 located on the push side of the displacement rod 83 within the internal space of the main body 82 and pulling-side internal space 822 located on the pull side of the displacement rod 83 within the internal space of the main body 82.

[0059] The main body 82 is fixed to the casing 351 by a support mechanism 84 including a bolt and nut structure. A valve element 352 is attached to the tip of the displacement rod 83. In response to commands from the control unit 60, the air cylinder 353 supplies air to and exhausts air from the push-side internal space 821, and exhausts air from and supplies air to the pull-side internal space 822, thereby displacing the displacement rod 83 and causing the valve element 352 to reciprocate along the direction of the valve element axis 810.

[0060] 4, the valve element 352 faces the upstream opening 710 in the direction of the valve element axis 810. As described above, the contact surface 81 is substantially parallel to the upstream opening 710, and the outer diameter of the contact surface 81 is larger than the outer diameter of the upstream opening 710. As a result, when the valve element 352 advances toward the upstream opening 710 by driving the air cylinder 353 and the contact surface 81 comes into contact with the end of the upstream connecting pipe 72, the upstream opening 710 is closed. As a result, even when the blowers 50a and 50b (described later) are driven to generate an airflow in the transport piping 30 from a selected one of the first hoppers 10a and 10b, which are the transport sources, to a selected one of the second hoppers 20a and 20b, which are the transport destinations, the inflow of powder and granular material into the casing 351 through the upstream opening 710 is stopped.

[0061] On the other hand, when the valve element 352 is retracted from the upstream opening 710 by the actuation of the air cylinder 353 and the contact surface 81 is separated from the end of the upstream connecting pipe 72, the upstream opening 710 is opened. As a result, when the blowers 50a, 50b (described later) are actuated to generate an airflow in the transport piping 30 from a selected one of the first hoppers 10a, 10b, which are the transport sources, to a selected one of the second hoppers 20a, 20b, which are the transport destinations, the powder or granular material flows into the casing 351 through the upstream opening 710 and flows out through the downstream opening 730. In this embodiment, the outlet-side on-off valves 35a, 35b can be configured at low cost with such a simple structure.

[0062] The exhaust pipes 40a, 40b are pipes for sucking air out of the second hoppers 20a, 20b. The upstream end of the exhaust pipe 40a is connected to the exhaust port 26 of the second hopper 20a. The downstream end of the exhaust pipe 40a is connected to the blower 50a. The upstream end of the exhaust pipe 40b is connected to the exhaust port 26 of the second hopper 20b. The downstream end of the exhaust pipe 40b is connected to the blower 50b.

[0063] The blowers 50a, 50b are mechanisms that generate airflow for sucking and transporting powder and granular material. The blowers 50a, 50b are an example of the airflow generating means of the present invention. The blowers 50a, 50b generate airflow in the exhaust pipes 40a, 40b by rotating their impellers in response to a drive signal input from the control unit 60. In addition to a configuration in which a blower is connected individually to each of the second hoppers 20a, 20b, a single blower may be connected to each of the second hoppers 20a, 20b and used by switching between them as appropriate.

[0064] When the second hopper 20a is selected as the destination of the powdered or granular material from among the second hoppers 20a and 20b, the blower 50a connected to the second hopper 20a via the exhaust pipe 40a is driven. The air inside the second hopper 20a is then sucked into the exhaust pipe 40a and discharged to the outside through the blower 50a. This causes the air pressure inside the second hopper 20a to become negative, lower than the outside air pressure. This causes outside air to be drawn into the transport piping 30 from the opening 320 of the inlet branch pipe (one of the inlet branch pipe 32a and the inlet branch pipe 32b) connected to the first discharge port 14 of the first hopper 10a, 10b selected as the source of the powdered or granular material. As a result, an airflow is generated in the transport piping 30, flowing from the first hopper 10a, 10b selected as the source of the powdered or granular material toward the second hopper 20a, the destination of the powdered or granular material.

[0065] Furthermore, when the second hopper 20b is selected as the destination of the powdered or granular material, the blower 50b connected to the second hopper 20b via the exhaust pipe 40b is driven. The air inside the second hopper 20b is then sucked into the exhaust pipe 40b and discharged to the outside through the blower 50b. This causes the air pressure inside the second hopper 20b to become negative, lower than the outside air pressure. This causes outside air to be drawn into the transport piping 30 through the opening 320 of the inlet branch pipe (one of the inlet branch pipe 32a and the inlet branch pipe 32b) connected to the first discharge port 14 of the first hopper 10a, 10b selected as the source of the powdered or granular material. As a result, an airflow is generated in the transport piping 30, flowing from the first hopper 10a, 10b selected as the source of the powdered or granular material toward the second hopper 20b, which is the destination of the powdered or granular material. In this embodiment, with such a simple structure, it is possible to generate an air current that flows from the first hoppers 10a and 10b, which are the transport sources, to the second hoppers 20a and 20b, which are the transport destinations.

[0066] The exhaust ports 26 of the second hoppers 20a, 20b are each provided with a filter 28. The filter 28 prevents the powder from flowing into the exhaust pipes 40a, 40b while allowing air to pass through. The filter 28 is, for example, a punched metal plate having a plurality of through holes smaller than the powder.

[0067] In this embodiment, first, one of the first hoppers 10a, 10b is selected as the source of the powder or granular material, and one of the second hoppers 20a, 20b is selected as the destination of the powder or granular material. Then, an inlet-side valve (either the inlet-side valve 33a or the inlet-side valve 33b) located on the route from the selected source to the selected destination is opened, and an inlet-side valve (the other of the inlet-side valve 33a or the inlet-side valve 33b) not included in the route is closed. Then, an outlet-side valve (either the outlet-side valve 35a or the outlet-side valve 35b) located on the route from the selected source to the selected destination is opened, and an outlet-side valve (the other of the outlet-side valve 35a or the outlet-side valve 35b) not included in the route is closed. This allows a powder or granular material transport route from the selected source to the selected destination to be formed. That is, in this embodiment, the above-described structure constitutes a transportation switching device and transportation switching method that switch the transportation route connecting the first hoppers 10a, 10b, which are multiple transportation sources, and the second hoppers 20a, 20b, which are multiple transportation destinations. Also, in this embodiment, the above-described simple structure makes it possible to switch the transportation route from the first hoppers 10a, 10b, which are multiple transportation sources, to the second hoppers 20a, 20b, which are multiple transportation destinations, at low cost.

[0068] The control unit 60 is a control means that controls the operation of each unit of the transportation system 1. Figure 5 is a block diagram showing the connection between the control unit 60 and each unit in the transportation system 1. As shown in Figure 5, the control unit 60 is electrically connected to an opening / closing mechanism 17 connected to the opening / closing valve 16 attached to each first discharge port 14 of the first hoppers 10a, 10b, an opening / closing mechanism 322 connected to a transport source valve 321 attached to the opening 320 of the inlet branch pipes 32a, 32b, an opening / closing mechanism 312a connected to an outside air introduction valve 311a attached to an outside air inlet 310a at the upstream end of the common pipe 31, an opening / closing mechanism 312b connected to an outside air introduction valve 311b attached to an outside air inlet 310b at the downstream end of the common pipe 31, an air cylinder 333 provided in each of the inlet side opening / closing valves 33a, 33b, an air cylinder 353 provided in each of the outlet side opening / closing valves 35a, 35b, an exhaust valve 27 attached to each second discharge port 25 of the second hoppers 20a, 20b, and blowers 50a, 50b. The control unit 60 is configured by a computer having a processing unit 601 such as a CPU, a memory 602, and a storage device 603.

[0069] The control unit 60 controls the operation of each of the above-mentioned units based on a preset operation sequence S and parameters P stored in the storage device 603, as well as external input signals. This allows the transportation of powder and granular material to proceed in the transportation system 1. However, the on-off valve 16, the transportation source valve 321, the outside air introduction valve 311a, the outside air introduction valve 311b, the inlet-side on-off valves 33a and 33b, the outlet-side on-off valves 35a and 35b, the discharge valve 27, and the blowers 50a and 50b may be separated from the control unit 60 and manually operated by an operator.

[0070] <2. Operation of the transportation system> Next, the operation of the above-described transportation system 1 when transporting powder or granular material will be described. Fig. 6 is a flowchart showing the flow of the powder or granular material transportation process. Fig. 7 is a schematic diagram for illustratively explaining the powder or granular material transportation process. Fig. 8 is a time chart showing the flow of the powder or granular material transportation process.

[0071] As described above, in the transportation process using the transportation system 1 of this embodiment, powdered or granular material is transported from one selected from among multiple sources to one selected from among multiple destinations. Specifically, first, one of the first hoppers 10a, 10b is selected as the source of the powdered or granular material, and one of the second hoppers 20a, 20b is selected as the destination of the powdered or granular material. Below, as an example, a case will be described in which the first hopper 10b of the first hoppers 10a, 10b is selected as the source, and the second hopper 20b of the second hoppers 20a, 20b is selected as the destination.

[0072] When starting the transportation of powder or granular material, first, a drive signal is supplied from the control unit 60 to open the inlet-side on-off valve 33b located on the path from the selected first hopper 10b, which is the transportation source, to the selected second hopper 20b, which is the transportation destination, thereby communicating the inlet-side branch pipe 32b connected to the first hopper 10b with the common pipe 31, while closing the inlet-side on-off valve 33a, which is not included in the path. Also, a drive signal is supplied from the control unit 60 to open the outlet-side on-off valve 35b located on the path from the selected first hopper 10b, which is the transportation source, to the selected second hopper 20b, which is the transportation destination, thereby communicating the outlet-side branch pipe 34b connected to the second hopper 20b with the common pipe 31, while closing the outlet-side on-off valve 35a, which is not included in the path.

[0073] Next, the control unit 60 sends a drive signal to the on-off mechanism 17 attached to the first discharge outlet 14 of the selected first hopper 10b, thereby opening the on-off valve 16. The control unit 60 also sends a drive signal to the on-off mechanism 322 attached to the opening 320 of the inlet branch pipe 32b connected to the selected first hopper 10b, thereby opening the transport source valve 321. This creates a transport path for transporting the powder or granular material from the first hopper 10b through the transport piping 30, which is composed of the inlet branch pipe 32b, the inlet on-off valve 33b, the common pipe 31, the outlet on-off valve 35b, and the outlet branch pipe 34b, to the second hopper 20b. The control unit 60 also sends a drive signal to close the discharge valves 27 attached to the second discharge outlets 25 of the second hoppers 20a and 20b.

[0074] Furthermore, the outside air introduction valve 311a attached to the outside air inlet 310a at the upstream end of the common pipe 31 as viewed in the powder / granule transport direction td, and the outside air introduction valve 311b attached to the outside air inlet 310b at the downstream end of the common pipe 31 as viewed in the powder / granule transport direction td, are closed. Then, at time t0, the control unit 60 supplies a drive signal to drive the blower 50b connected to the second hopper 20b, the selected transport destination, via the exhaust pipe 40b (step S1). This causes air to be sucked from the second hopper 20b, lowering the air pressure within the second hopper 20b. This causes outside air to be drawn into the transport piping 30 through the opening 320 of the inlet-side branch pipe 32b, generating an airflow from the first discharge port 14 of the first hopper 10b toward the inlet 24 of the second hopper 20b. As a result, the powder or granular material in the first hopper 10b is transported to the second hopper 20b through the transport pipe 30. Hereinafter, this process of transporting the powder or granular material in the transport source to the transport destination will be referred to as "main transport."

[0075] As described above, the control unit 60 has preset therein an operation sequence S for operating each unit in the transport process. After starting the operation of the blower 50b, the control unit 60 monitors whether the first operation time t1 has elapsed since the start of operation (time t0). Then, when the first operation time t1 has elapsed, the control unit 60 supplies a drive signal to the opening / closing mechanism 312b attached to the outside air inlet 310b of the common pipe 31 to open the outside air introduction valve 311b (step S2). That is, in this embodiment, the transport is performed while switching from a state in which the two outside air introduction valves 311a, 311b at both ends of the common pipe 31 are closed to a state in which the outside air introduction valve 311b provided at the downstream end of the common pipe 31 in the transport direction td of the powder and granular material is opened.

[0076] When the powder or granular material in the first hopper 10b is transported to the second hopper 20b through the transport pipe 30, the powder or granular material in the common pipe 31 may overrun by passing through position P4 instead of proceeding from position P4 through the outlet-side on-off valve 35b to the outlet-side branch pipe 34b. However, in this embodiment, by opening the outside air introduction valve 311b, outside air can be taken into the common pipe 31 from the outside air introduction port 310b through the filter 313b. This generates an airflow in the common pipe 31 from the outside air introduction port 310b toward position P4. As a result, even if the powder or granular material overruns in the common pipe 31, the powder or granular material can be returned and transported from position P4 to the second hopper 20b via the outlet-side on-off valve 35b and the outlet-side branch pipe 34b.

[0077] The control unit 60 then monitors whether a second operation time t2 has elapsed since the start of operation (time t0). When the second operation time t2 has elapsed, the control unit 60 supplies a drive signal to the opening / closing mechanism 312b to close the outside air introduction valve 311b that was opened in step S2 (step S3). Similarly, the control unit 60 opens the outside air introduction valve 311b again when a third operation time t3 has elapsed since the start of operation (time t0), closes the outside air introduction valve 311b again when a fourth operation time t4 has elapsed since the start of operation, opens the outside air introduction valve 311b again when a fifth operation time t5 has elapsed since the start of operation, and closes the outside air introduction valve 311b again when a sixth operation time t6 has elapsed since the start of operation. That is, in this embodiment, the transport is carried out by repeatedly switching between a state in which the two outside air introduction valves 311a, 311b are each closed and a state in which the outside air introduction valve 311b, which is provided at the downstream end of the common pipe 31 as viewed in the transport direction td of the powder and granular material, is opened.

[0078] In this manner, in this transportation, the process of transporting powder and granular material mainly from the first hopper 10b to the second hopper 20b while closing the two outside air introduction valves 311a, 311b, and the process of opening the outside air introduction valve 311b to return the overrun of powder and granular material in the common pipe 31 are repeated, thereby making it possible to transport the powder and granular material while suppressing the amount of powder and granular material remaining in the transportation pipe 30. However, in this transportation, the number of times and the time for which the outside air introduction valve 311b is opened and closed again are not limited to these. Also, in this transportation, the two outside air introduction valves 311a, 311b may be kept closed all the time.

[0079] The control unit 60 then monitors whether a seventh operation time t7 has elapsed since the start of operation (time t0) (step S4). If the seventh operation time t7 has not elapsed, the main transport continues, repeatedly opening and closing the outside air introduction valve 311b. On the other hand, if the seventh operation time t7 has elapsed, the control unit 60 determines that the main transport is complete and a predetermined amount of powder and granular material has been discharged from the first hopper 10b. At this time, the control unit 60 sends a drive signal to the opening / closing mechanism 17 attached to the first discharge outlet 14 of the first hopper 10b to close the opening / closing valve 16. Furthermore, after a predetermined time has elapsed since the opening / closing valve 16 was closed, the control unit 60 sends a drive signal to the opening / closing mechanism 322 attached to the opening 320 of the inlet-side branch pipe 32b connected to the first hopper 10b to close the transport source valve 321. However, the control unit 60 may determine that the main transport is completed and a predetermined amount of powder or granular material has been discharged from the first hopper 10b based on a detection signal from a level sensor (not shown) separately provided in the first hopper 10b.

[0080] When a seventh operating time t7 has elapsed since the start of operation (time t0), the control unit 60 closes the inlet-side on-off valve 33b located on the path from the first hopper 10b to the second hopper 20b, thereby interrupting communication between the inlet-side branch pipe 32b connected to the first hopper 10b and the common pipe 31. Closing the inlet-side on-off valve 33b is performed after closing the on-off valve 16 and the transport source valve 321. The blower 50b is then driven to suck air from the second hopper 20b (step S5). Step S5 is first performed with the two outside air introduction valves 311a, 311b at both ends of the common pipe 31 open. This allows outside air to be drawn into the common pipe 31 through the filters 313a, 313b, generating airflows from the outside air introduction ports 310a, 310b toward position P4 within the common pipe 31. As a result, the powder or granular material remaining in the transport piping 30, including the common pipe 31, the outlet-side on-off valve 35b, and the outlet-side branch pipe 34b, can be transported to the second hopper 20b. Hereinafter, the process of transporting such powder or granular material remaining in the transport piping 30 to the destination will be referred to as "remaining transport."

[0081] Next, the control unit 60 monitors whether an eighth operation time t8 has elapsed since the start of operation (time t0). Then, when the eighth operation time t8 has elapsed, the control unit 60 closes only the outside air introduction valve 311a of the two outside air introduction valves 311a, 311b. Similarly, when a ninth operation time t9 has elapsed since the start of operation, the control unit 60 opens the outside air introduction valve 311a and closes the outside air introduction valve 311b. When a tenth operation time t10 has elapsed since the start of operation, the control unit 60 closes the outside air introduction valve 311a and opens the outside air introduction valve 311b. When an eleventh operation time t11 has elapsed since the start of operation, the control unit 60 opens the outside air introduction valve 311a and closes the outside air introduction valve 311b.

[0082] That is, in this embodiment, the remaining transport is performed by first opening the two outside air introduction valves 311a, 311b, and then switching multiple times between a state in which only the outside air introduction valve 311b provided at the downstream end of the common pipe 31 as seen in the transport direction td of the powder and granular material is opened, and a state in which only the outside air introduction valve 311a provided at the upstream end of the common pipe 31 as seen in the transport direction td of the powder and granular material is opened (step S6). That is, in this embodiment, the remaining transport is performed with at least one of the two outside air introduction valves 311a, 311b open.

[0083] In the above-described transport, when powder or granular material that has overrun within the common pipe 31 is returned, the powder or granular material may return too far and reach a position upstream of the common pipe 31 in the transport direction td of the powder or granular material, where it may remain. However, in this embodiment, the two outside air introduction valves 311a and 311b are first opened, and then the outside air introduction valve 311a and the outside air introduction valve 311b are alternately opened, thereby allowing outside air to be taken into the common pipe 31 through the outside air introduction ports 310a and 310b. This generates an airflow within the common pipe 31 that flows from the outside air introduction ports 310a and 310b toward position P4. As a result, the powder or granular material remaining in the common pipe 31 can be transported to the second hopper 20b via position P4.

[0084] That is, in this embodiment, even if the powder or granular material returns too far upstream in the transport direction td when the overrunning powder or granular material in the common pipe 31 is returned, the powder or granular material can be moved downstream again and transported to the destination. However, the number of times and the time for which the two outside air introduction valves 311a, 311b are switched between open and closed during the remaining transport are not limited to these. Furthermore, during the remaining transport, the two outside air introduction valves 311a, 311b may each be kept open all the time.

[0085] The control unit 60 then monitors whether a twelfth operation time t12 has elapsed since the start of operation (time t0) (step S7). If the twelfth operation time t12 has not elapsed, the remaining transport continues, and the two outside air introduction valves 311a, 311b are repeatedly opened and closed. On the other hand, once the twelfth operation time t12 has elapsed, the two outside air introduction valves 311a, 311b are finally opened again (step S8). After that, once a predetermined time has elapsed (a thirteenth operation time t13 has elapsed since the start of operation), the control unit 60 determines that the remaining transport is complete and that the powder and granular material remaining in the transport piping 30, including the common pipe 31, the outlet-side opening / closing valve 35b, and the outlet-side branch pipe 34b, has been transported to the second hopper 20b.

[0086] The control unit 60 also supplies a drive signal to stop the operation of the blowers 50a and 50b in the transport system 1 and close each valve. In this embodiment, the control unit 60 supplies a drive signal to stop the operation of the blower 50b and to switch the outside air introduction valves 311a and 311b and the outlet-side opening / closing valve 35b from an open state to a closed state. This completes the process of transporting powder or granular material from the first hopper 10b, which is the selected source, to the second hopper 20b, which is the selected destination, in the transport system 1. Thereafter, one of the multiple first hoppers is selected as the source of the powder or granular material, and one of the multiple second hoppers is selected as the destination of the powder or granular material. By similarly executing steps S1 to S8, multidirectional transport of powder or granular material in the transport system 1 can be achieved.

[0087] <3. Modifications> Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

[0088] In the above embodiment, the powder or granular material is transported by suction while creating a negative pressure at the destination. However, the powder or granular material transport method of the present invention may be such that the vicinity of the source is created with a positive pressure and the powder or granular material is pumped to the destination. In this case, for example, blowers 50a and 50b may be disposed near opening 320. Furthermore, the means for generating the airflow does not necessarily have to be a blower.

[0089] The transportation system 1 of the present invention may also be used to transport powders and granules other than resin pellets, which are materials for resin molded products, and recycled materials. For example, the transportation system may be used to transport powders and granules used in various fields, such as pharmaceuticals, chemical products, food, and building materials.

[0090] The detailed configuration of the transportation system may differ from that shown in the drawings of the present application. Furthermore, the elements appearing in the above-described embodiments and modifications may be combined as appropriate within the scope of not causing any contradiction. [Explanation of symbols]

[0091] 1. Transportation System 10a, 10b First hopper 20a, 20b Second hopper 30 Transportation piping 31 Common pipe 32a, 32b Inlet branch pipe 33a, 33b Inlet side opening / closing valve 34a, 34b Outlet branch pipe 35a, 35b Outlet side opening and closing valve 36 Support member 40a, 40b Exhaust pipe 50a, 50b blower 71 (Upstream end of inlet valve and outlet valve) 73 Downstream end (of inlet valve and outlet valve) 310a, 310b Outside air intake 311a, 311b Outside air intake valve 312a,312b Opening / closing mechanism 313a, 313b Filter 331 (Inlet side opening / closing valve) casing 332 (Inlet side opening and closing valve) valve body 333 Air cylinder (inlet side opening / closing valve) 351 (Outlet side opening and closing valve) Casing 352 (Outlet side opening and closing valve) valve body 353 Air cylinder (outlet side opening and closing valve) 710 (Inlet and outlet valves) Upstream opening 730 Downstream opening (of inlet and outlet valves) td (powder) transport direction

Claims

1. A transportation system for transporting powder or granular material from one selected from a plurality of transportation sources to one selected from a plurality of transportation destinations, comprising: a transportation switching device for switching a transportation route connecting the plurality of transportation sources and the plurality of transportation destinations, Transport piping that constitutes the transport route Including, The transportation pipe is One common pipe, two outside air introduction valves provided at both ends of the common pipe, each of which allows the end of the common pipe to be opened to outside air; a plurality of inlet-side branch pipes each branching from a plurality of positions spaced apart from one another in the common pipe and each connected to one of the plurality of transport sources; a plurality of inlet-side on-off valves that switch communication between each of the plurality of inlet-side branch pipes and the common pipe; a plurality of outlet branch pipes branching from a plurality of positions spaced apart from one another in the common pipe and each connected to one of the plurality of transport destinations; a plurality of outlet-side on-off valves that switch communication between each of the plurality of outlet-side branch pipes and the common pipe; A transportation switching device having:

2. The transportation switching device according to claim 1, The common pipe is formed in a spiral shape and supported by a support member.

3. The transportation switching device according to claim 1 or 2; the plurality of shipping origins; the plurality of shipping destinations; an airflow generating means for generating an airflow in the transport piping from the transport source to the transport destination; A transportation system having:

4. 4. The transportation system of claim 3, Each of the plurality of inlet side on-off valves is a casing having an upstream end provided with an upstream opening to which the inlet branch pipe is connected, and a downstream end provided with a downstream opening to which the common pipe is connected; a valve body that opens and closes the upstream opening; an air cylinder that moves the valve body back and forth in a direction perpendicular to the upstream opening; and When the valve body opens the upstream opening by driving the air cylinder, the powder flows into the casing and flows out from the downstream opening, When the valve body closes the upstream opening by driving the air cylinder, the flow of powder and granular material into the casing is stopped.

5. 4. The transportation system of claim 3, Each of the plurality of outlet side on-off valves is a casing having an upstream end provided with an upstream opening to which the common pipe is connected, and a downstream end provided with a downstream opening to which the outlet branch pipe is connected; a valve body that opens and closes the upstream opening; an air cylinder that moves the valve body back and forth in a direction perpendicular to the upstream opening; and When the valve body opens the upstream opening by driving the air cylinder, the powder flows into the casing and flows out from the downstream opening, When the valve body closes the upstream opening by driving the air cylinder, the flow of powder and granular material into the casing is stopped.

6. 6. A transportation system according to any one of claims 3 to 5, The airflow generating means generates an airflow in the transport piping that flows from the transport source to the transport destination by sucking air from the selected one of the transport destinations.

7. A transportation switching method for switching a transportation route connecting a plurality of transportation sources and a plurality of transportation destinations in a transportation process of transporting powder or granular material from a selected one of a plurality of transportation sources to a selected one of a plurality of transportation destinations, the method comprising: The transport piping constituting the transport route includes: One common pipe, two outside air introduction valves provided at both ends of the common pipe, each of which allows the end of the common pipe to be opened to outside air; a plurality of inlet-side branch pipes each branching from a plurality of positions spaced apart from one another in the common pipe and each connected to one of the plurality of transport sources; a plurality of inlet-side on-off valves that switch communication between each of the plurality of inlet-side branch pipes and the common pipe; a plurality of outlet branch pipes branching from a plurality of positions spaced apart from one another in the common pipe and each connected to one of the plurality of transport destinations; a plurality of outlet-side on-off valves that switch communication between each of the plurality of outlet-side branch pipes and the common pipe; and a) a step of communicating the inlet branch pipe connected to the selected one transport source with the common pipe by opening the inlet-side on-off valve, communicating the outlet branch pipe connected to the selected one transport destination with the common pipe by opening the outlet-side on-off valve, and sucking air from the selected one transport destination, thereby transporting powder or granular material from the transport source to the transport destination. and The step a) is a transportation switching method in which the two outside air introduction valves are switched from a closed state to an open state in which the outside air introduction valve provided at the downstream end of the common pipe, as viewed in the transport direction of the powder or granular material, is opened.

8. The transportation switching method according to claim 7, The step a) is a transport switching method in which the step a) is performed by switching multiple times between a state in which the two outside air introduction valves are closed and a state in which the outside air introduction valve provided at the downstream end of the common pipe, as viewed in the transport direction of the powder and granular material, is opened.

9. The transportation switching method according to claim 7 or 8, b) after step a), closing the inlet-side on-off valve to block communication between the inlet-side branch pipe connected to the selected one transport source and the common pipe, and sucking air from the selected one transport destination to transport the powder or granular material remaining in the transport pipeline to the selected one transport destination. and The transportation switching method, wherein the step b) is performed in a state where at least one of the two outside air introduction valves is open.

10. The transportation switching method according to claim 9, The transportation switching method, wherein the step b) is initially performed with the two outside air introduction valves both open.

11. The transportation switching method according to claim 10, The step b) is a transportation switching method in which, after opening each of the two outside air introduction valves, the step b) is performed by switching multiple times between a state in which only the outside air introduction valve provided at the downstream end of the common pipe, as viewed in the transport direction of the powder or granular material, is opened, and a state in which only the outside air introduction valve provided at the upstream end of the common pipe, as viewed in the transport direction of the powder or granular material, is opened.

Images