Rotary valve

Abstract

To provide a technique capable of suppressing noise occurrence in a rotary valve used for transporting a powder flow.SOLUTION: A rotary valve 30 has: a casing 41; a rotor shaft 51 extending along an axis of rotation extending in an axial direction; and a rotor body 500 which rotates together with the rotor shaft 51 and housed in the casing 41. The rotor body 500 has a plurality of plate-like blades 53 extending radially around the axis of rotation. The casing 41 has a first inner surface 41a opposed to an axial end face of the rotor body 500 across a slight gap, and a second inner surface 41b opposed to tip faces of the blades 53 across a slight gap. Powder material is flaky, and a first inner surface 41a and a second inner surface 41b are roughened. The roughening suppresses noise generated as the powder material caught in the gaps moves in contact with the inner surfaces 41a, 41b.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a rotary valve. [Background technology]

[0002] Conventionally, when transporting powdery liquids, a rotary valve has been used as a device that is provided at the discharge outlet of a powdery liquid storage container and that can adjust the supply speed of the powdery liquid. A conventional rotary valve is disclosed in, for example, Patent Document 1.

[0003] As described in Patent Document 1, a typical rotary valve has a rotor with multiple blades extending radially between an upper inlet and a lower outlet. The rotor rotates around a horizontal axis, sending the powder liquid supplied from the upper inlet to the lower outlet. By controlling the number and speed of rotation of the rotor, the powder liquid can be discharged in the desired amount and at the desired supply rate.

[0004] In rotary valves, in order to prevent powdered fluid from leaking out when rotation is stopped, a small gap is provided between the tips of the rotor blades and the inner surface of the casing that houses the rotor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-161215 Summary of the Invention [Problem to be solved by the invention]

[0006] Depending on the size and type of powder, it may become trapped in this gap. If the powder gets caught in the gap and rotates with the rotor, friction occurs between the powder and the inner surface of the casing, which generates heat and can cause the powder to melt and form clumps, or can cause abnormal noise due to friction. In particular, crushed material from PET bottles becomes plate flakes, which are prone to rotating with the rotor if they get caught in the gap and can easily cause abnormal noise.

[0007] An object of the present invention is to provide a technique capable of suppressing the generation of abnormal noise in a rotary valve used for transporting powdery fluids. [Means for solving the problem]

[0008] In order to solve the above problems, the first invention of the present application is a rotary valve that supplies powder or granular material from above to below, comprising: a casing having a powder or granular material inlet at an upper part and a powder or granular material outlet at a lower part; a rotor shaft extending along an axial rotation axis; and a rotor body that rotates together with the rotor shaft and is housed inside the casing, wherein the rotor body is positioned below the powder or granular material inlet and above the powder or granular material outlet, and the rotor body has a plurality of plate-shaped blades that extend radially from the rotation axis, the casing has a first inner surface that faces the axial end face of the rotor body across a small gap, and a second inner surface that faces the tip faces of the blades across a small gap, the powder or granular material is in flake form, and the first inner surface and the second inner surface are roughened.

[0009] A second aspect of the present invention is the rotary valve of the first aspect, wherein the axial end faces of the rotor body and the tip faces of the blades are roughened.

[0010] The third invention of the present application is a rotary valve that supplies powder or granular material from above to below, comprising: a casing having a powder or granular material inlet at an upper part and a powder or granular material outlet at a lower part; a rotor shaft extending along an axial rotation axis; and a rotor body that rotates together with the rotor shaft and is housed inside the casing, wherein the rotor body is positioned below the powder or granular material inlet and above the powder or granular material outlet, and the rotor body has a plurality of plate-shaped blades that extend radially from the rotation axis, the casing has a first inner surface that faces the axial end face of the rotor body across a small gap, and a second inner surface that faces the tip faces of the blades across a small gap, the powder or granular material is in flake form, and the axial end face of the rotor body and the tip faces of the blades are roughened.

[0011] A fourth invention of the present application is a rotary valve according to any one of the first to third inventions, wherein the rotor body further has two circular side plates connected to both axial ends of the plurality of blades and perpendicular to the rotation axis, and the axial end faces of the rotor body are the outer surfaces of the side plates.

[0012] A fifth aspect of the present invention is the rotary valve of any one of the first to third aspects, wherein the surface roughening is performed by sandblasting with a sand diameter of 100 μm or more and 1 mm or less.

[0013] A sixth aspect of the present invention is the rotary valve of any one of the first to third aspects, wherein the powdered material is crushed material for PET bottles. [Effects of the Invention]

[0014] According to the first to sixth aspects of the present invention, it is possible to prevent flake-shaped powder particles from being caught between the rotor body and the inner surface of the casing and generating abnormal noise. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic diagram showing the configuration of a powder or granular material transport system according to a first embodiment. [Figure 2] FIG. 2 is a top view of the loader hopper according to the first embodiment. [Figure 3] FIG. 2 is a partial cross-sectional view of the loader hopper according to the first embodiment. [Figure 4] FIG. 2 is a partial cross-sectional view of the loader hopper according to the first embodiment. [Figure 5] FIG. 2 is a perspective view of a rotor of the loader hopper according to the first embodiment. [Figure 6] FIG. 10 is a perspective view of a rotor of a loader hopper according to another modified example. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0017] 1. First Embodiment <1-1. Configuration of powder and granular material transport system> FIG. 1 is a schematic diagram showing the configuration of a powder / granular material transport system 1 including a rotary valve 30 according to one embodiment of the present invention. This powder / granular material transport system 1 is a mechanism for supplying resin pellets stored in a storage tank 21 to a flexible container bag 9 as a supply destination via a loader hopper 24. In this embodiment, the powder / granular material to be transported is flake-shaped (plate-shaped) crushed PET material (hereinafter simply referred to as "crushed material") made by crushing PET bottles. However, the powder / granular material to be transported is not limited to this, and may be resin pellets, which are a plastic molding material, or other powder / granular material. Furthermore, the shape of the powder / granular material to be transported may be any shape, such as spherical, cylindrical, or plate-like.

[0018] As shown in FIG. 1, the powder transport system 1 includes a storage tank 21, a supply pipe 22, a supply blower 23, a loader hopper 24, a suction pipe 25, a suction blower 26, a dust collector 27, a rotary valve 30, and a control unit 10.

[0019] The storage tank 21 is a supply source of the material to be crushed. The storage tank 21 is a container that stores the material to be crushed inside. A discharge port 211 for discharging the material to be crushed is provided at the bottom end of the storage tank 21.

[0020] One end of the supply pipe 22 is connected to the discharge port 211 of the storage tank 21. The pulverized material stored in the storage tank 21 is supplied into the supply pipe 22 by gravity. The other end of the supply pipe 22 is connected to a supply port 241 provided at the top of the loader hopper 24.

[0021] A supply blower 23 is inserted into the supply pipe 22. The supply blower 23 is an airflow generating means that generates an airflow inside the supply pipe 22. When the supply blower 23 is driven, an airflow is generated that flows from one end of the supply pipe 22 to the other end. That is, when the supply blower 23 is driven, an airflow is generated inside the supply pipe 22 that flows from the discharge port 211 of the storage tank 21 toward the loader hopper 24. This transports the pulverized material from the storage tank 21 to the supply port 241 of the loader hopper 24.

[0022] The loader hopper 24 separates the pulverized material supplied to a supply port 241 provided at the top from the airflow and discharges the pulverized material from a discharge port 242. The loader hopper 24 has a separation section 81 and a stock section .

[0023] The separation section 81 has a cyclone structure and separates the pulverized material and gas supplied from the supply port 241. The pulverized material separated in the separation section 81 falls into the stock section 82 arranged below the separation section 81. The gas separated in the separation section 81 is discharged from the suction pipe 25.

[0024] The stock section 82 temporarily stores the pulverized material discharged from the separation section 81. A discharge port 242 for discharging the pulverized material is provided at the lower end of the stock section 82. The discharge port 242 is connected to the rotary valve 30.

[0025] The rotary valve 30 is a device that discharges powder and granular material supplied to an upper powder and granular material inlet 31 from a lower powder and granular material outlet 32 at a desired supply speed. The rotary valve 30 discharges the pulverized material stored in the stock section 82 from the loader hopper 24 while adjusting the discharge rate, and supplies it to the flexible container bag 9. The rotary valve 30 will be described in detail later.

[0026] The flexible container bag 9 is a flexible container bag of the transport destination. When the rotary valve 30 is driven, the pulverized material is supplied from the discharge port 242 of the loader hopper 24 to the flexible container bag 9 arranged below the loader hopper 24.

[0027] The destination of the powder and granular material in the powder and granular material transport system 1 is not limited to the flexible container bag 9. For example, the powder and granular material may be resin pellets, and the destination of the powder and granular material may be an injection molding machine that performs injection molding using the resin pellets as a material. The destination of the powder and granular material may also be another device, such as a drying device that performs a drying process on the powder and granular material, or a mixing device that mixes multiple types of powder and granular material.

[0028] One end of the suction pipe 25 is connected to an exhaust port 243 provided at the top of the loader hopper 24. A filter made of punched metal or wire mesh is provided at the exhaust port 243. This prevents the resin pellets stored inside the loader hopper 24 from getting mixed into the suction pipe 25. The other end of the suction pipe 25 is connected to a blower 26. A dust collector 27 is also inserted into the suction pipe 25.

[0029] The blower 26 is an airflow generating means that generates an airflow inside the suction pipe 25. When the blower 26 is driven, an airflow is generated that flows from one end of the suction pipe 25 to the other end. That is, when the blower 26 is driven, an airflow is generated inside the suction pipe 25 that flows from the exhaust port 243 of the loader hopper 24 toward the blower 26. The gas discharged from the inside of the loader hopper 24 to the suction pipe 25 through the exhaust port 243 has dust removed in the dust collector 27, and then is discharged to the outside via the blower 26.

[0030] On the other hand, when the gas inside the loader hopper 24 is exhausted from the exhaust port 243, the gas supplied into the loader hopper 24 from the supply pipe 22 flows through the exhaust port 243 to the suction pipe 25. This prevents the air pressure inside the loader hopper 24 from increasing due to the gas supplied into the loader hopper 24 from the supply pipe 22. The material to be pulverized may be transported from the storage tank 21 by the airflow caused by the suction of the blower 26 alone, and in this case the supply blower 23 may be used.

[0031] The dust collector 27 separates and collects dust contained in the gas discharged from the loader hopper 24 through the suction pipe 25. As the dust collector 27, for example, a so-called cyclone type dust collector is used.

[0032] The control unit 10 controls the operation of each part of the powder / granular material transport system 1. Specifically, the control unit 10 is electrically connected to the supply blower 23, the suction blower 26, and the rotary valve 30. The control unit 10 is configured by a computer having a processing unit such as a CPU and a memory. The control unit 10 may also be configured by an electronic circuit board. The control unit 10 controls the operation of each of the above parts based on a preset program or an input signal from an external source. This allows the powder / granular material transport process in the powder / granular material transport system 1 to proceed.

[0033] <1-2. Rotary valve configuration> Next, the detailed configuration of the rotary valve 30 will be described with reference to Figs. 2 to 5. The rotary valve 30 of this embodiment is a rotary valve having a so-called pocket-type rotor. Fig. 2 is a top view of the rotary valve 30. Fig. 3 is a cross-sectional view of the main casing 41 and rotor 50 of the rotary valve 30 taken along arrows A-A. Fig. 4 is a cross-sectional view of the main casing 41 and rotor 50 of the rotary valve 30 taken along arrows B-B. Fig. 5 is a perspective view of the rotor 50 of the rotary valve 30.

[0034] The rotary valve 30 has a casing 40, a rotor 50, a motor 61, and a power transmission unit 62. The casing 40 is a housing that houses the rotor 50, the motor 61, and the power transmission unit 62 inside.

[0035] 2 to 4, the casing 40 has a main casing 41, a first side casing 42, a second side casing 43, a motor casing 44, and a transmission casing 45. As shown in FIGS. 3 to 5, the rotor 50 has a rotor shaft 51, a core 52, a plurality of blades 53, and two side plates 54.

[0036] The rotor shaft 51 of the rotor 50 is a cylindrical portion. The rotor shaft 51 is arranged horizontally. The rotor shaft 51 is supported by bearings 510 so as to be rotatable about the central axis of the rotor shaft 51. The rotor 50 rotates together with the rotor shaft 51 about the central axis of the rotor shaft 51. Hereinafter, the central axis of the rotor shaft 51 will be referred to as the "rotation axis," and the direction in which the rotor shaft 51 extends will be referred to as the "axial direction."

[0037] The core 52 is a cylindrical portion surrounding the rotor shaft 51. Each of the plurality of blades 53 is a plate-shaped portion extending radially from the core 52 around the rotation axis. The space between two adjacent blades 53 serves as a storage space for storing the material to be crushed. In this embodiment, the rotor 50 has six blades 53, but the number of blades 53 possessed by the rotor 50 is not limited to six. Each of the two side plates 54 is a disk-shaped portion connected to both axial ends of the blade 53. Hereinafter, the core 52, the plurality of blades 53, and the two side plates 54 of the rotor 50, excluding the rotor shaft 51, will be referred to as the rotor main body 500.

[0038] The material to be crushed passes through the main casing 41. The main casing 41 houses a part of the rotor shaft 51 of the rotor 50 and the rotor body 500 inside. The main casing 41 has a powder inlet 31 that opens upward at its upper end. The main casing 41 also has a powder outlet 32 that opens downward at its lower end.

[0039] The main casing 41 has a pair of first side walls 411 that face the rotor body 500 in the axial direction, and a second side wall 412 that faces the rotor body 500 horizontally and in a direction perpendicular to the axial direction.

[0040] The first side wall 411 has a first inner surface 41a that faces, across a small gap, the axial end face of the rotor body 500. In this embodiment, the axial end face of the rotor body 500 is the outer surface of the side plate 54. That is, the first inner surface 41a faces, across a small gap, the outer surface of the side plate 54.

[0041] The second side wall 412 has a second inner surface 41b that faces the tip surfaces of the blades 53 with a small gap between them. That is, the second inner surface 41b of the second side wall 412 faces the rotation trajectory of the tip surfaces of the blades 53 and the outer edge of the side plate 54 with a small gap between them. Therefore, the second inner surface 41b is a curved surface that is a partially cut-out cylindrical shape.

[0042] The first side casing 42 accommodates a portion of the rotor shaft 51, including one end thereof, exposed from the main casing 41, and a bearing 510 that rotatably holds the rotor shaft 51. The second side casing 43 accommodates a portion of the other end of the rotor shaft 51, exposed from the main casing 41, and the bearing 510 that rotatably holds the rotor shaft 51. The other end of the rotor shaft 51 is disposed within the transmission casing 45.

[0043] The motor casing 44 accommodates the motor 61 therein. The transmission casing 45 accommodates the power transmission unit 62 therein.

[0044] The motor 61 is a source of rotational power for rotating the rotor 50. The motor 61 has an output shaft 610 arranged parallel to the rotor shaft 51 of the rotor 50. The main body of the motor 61 is housed inside the motor casing 44. The output shaft 610 protrudes from the motor casing 44, and the tip of the output shaft 610 is arranged inside the transmission casing 45.

[0045] The power transmission unit 62 is disposed inside the transmission casing 45. The power transmission unit 62 transmits rotational power from the output shaft 610 of the motor 61 to the rotor shaft 51 of the rotor 50. The power transmission unit 62 may be formed, for example, by sprockets fixed to each of the output shaft 610 and the rotor shaft 51, and a chain. Alternatively, the power transmission unit 62 may be formed, for example, by pulleys (wheels) fixed to each of the output shaft 610 and the rotor shaft 51, and a belt.

[0046] When pulverized material is introduced into the main casing 41 through the powder / granular material inlet 31, the pulverized material is stored in the space above the rotor body 500, and also in the storage spaces between adjacent blades 53 that face the powder / granular material inlet 31. When the motor 61 is driven, the power transmission unit 62 transmits rotational power from the output shaft 610 to the rotor shaft 51, causing the entire rotor 50 to rotate together with the rotor shaft 51. As a result, when a storage space containing pulverized material reaches a downward position, the pulverized material falls and is discharged from the powder / granular material outlet 32. On the other hand, when a storage space not containing pulverized material reaches an upward position, the pulverized material stored in the space above the rotor body 500 flows into the empty storage space. Then, as the rotor 50 rotates, when a storage space containing newly filled pulverized material reaches a downward position, the pulverized material falls and is discharged from the powder / granular material outlet 32.

[0047] With this configuration, the amount of pulverized material discharged from the powder / granular material outlet 32 can be adjusted appropriately by adjusting the rotation speed of the rotor 50.

[0048] When pulverized material is placed inside the main casing 41, the gap between the first inner surface 41a and the side plate 54 and the gap between the second inner surface 41b and the tip of the blade 53 are small enough that the pulverized material does not leak downward from these gaps and almost never falls from the lower powder / granular material outlet 32. However, there are cases where the pulverized material gets caught in these gaps.

[0049] For example, if the gap between the first inner surface 41a and the side plate 54 and the gap between the second inner surface 41b and the tip of the blade 53 are approximately 0.2 mm, and the thickness of the crushed material is approximately 0.2 mm, the crushed material will hardly leak downward, but it is quite possible that the crushed material will become trapped in these gaps. In such a case, unless special processing is performed on the rotor 50 or the main casing 41, the trapped crushed material will rotate together with the rotor 50, and friction between the crushed material and the first inner surface 41a and the second inner surface 41b may cause abnormal noise. This abnormal noise is particularly likely to occur when the crushed material is crushed PET bottles.

[0050] In this embodiment, the first inner surface 41a and the second inner surface 41b are roughened. This roughening is performed by sandblasting with a sand diameter of 100 μm or more and 1 mm or less. By roughening the first inner surface 41a and the second inner surface 41b, the contact area of the crushed material that rotates together with the rotor 50 when it moves while making contact with the first inner surface 41a and the second inner surface 41b can be reduced. This makes it possible to suppress the generation of abnormal noise. In particular, it has been confirmed that the generation of abnormal noise can be effectively suppressed when the crushed material is crushed PET bottles and the sandblasting sand diameter is 100 μm or more and 1 mm or less.

[0051] The roughening process is not limited to sandblasting, and may be other roughening processes such as knurling. Even if other roughening processes are used, it is possible to reduce the contact area between the pulverized material and the first inner surface 41a and the second inner surface 41b, and suppress the generation of abnormal noise.

[0052] <2. Modifications> Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

[0053] <2-1. First modified example> In the above embodiment, the first inner surface 41a and the second inner surface 41b of the main casing 41 are roughened, but the present invention is not limited to this. The first inner surface 41a and the second inner surface 41b may not be roughened, and only the tip surfaces of the plurality of blades 53 of the rotor 50 and the axial end surface of the rotor body 500 (the outer surface of the side plate 54 in the above embodiment) may be roughened.

[0054] In this case, the pulverized material is less likely to adhere to the tip surfaces of the blades 53 and the axial end surfaces of the rotor body 500, and is less likely to rotate together with the rotor 50. This makes it possible to suppress the generation of abnormal noise due to friction between the pulverized material and the first inner surface 41a and the second inner surface 41b.

[0055] <2-2. Second modified example> In the above embodiment, the first inner surface 41a and the second inner surface 41b of the main casing 41 are roughened, but the present invention is not limited to this. In addition to the first inner surface 41a and the second inner surface 41b, the tip surfaces of the plurality of blades 53 of the rotor 50 and the axial end surface of the rotor body 500 (the outer surface of the side plate 54 in the above embodiment) may also be roughened.

[0056] In this case, the pulverized material is less likely to adhere to the tip surfaces of the blades 53 and the axial end surfaces of the rotor body 500, making it less likely to rotate together with the rotor 50. Furthermore, even if the pulverized material rotates together with the rotor 50, the contact area of the pulverized material rotating together with the rotor 50 as it moves while in contact with the first inner surface 41a and the second inner surface 41b can be reduced, thereby further suppressing the generation of abnormal noise.

[0057] <2-3.Third modified example> FIG. 6 is a perspective view of a rotor 50A of a rotary valve according to a modified example. This rotor 50A is a so-called open-type rotor that does not have a side plate. In this rotor 50A, the axial end faces of the blades 53A are the axial end faces of the rotor body 500A. Therefore, the axial end faces of the blades 53A face the second inner surface 41b with a small gap between them. Therefore, when roughening the rotor body 500A, the tip surfaces and axial end faces of the blades 53A are roughened.

[0058] <2-4. Other variations> Furthermore, although the rotary valve in the above embodiment is used in a powder / granular material transport system, the present invention is not limited to this and can be applied to any other system as long as it is a rotary valve used in conjunction with a powder / granular material storage container.

[0059] Furthermore, the detailed shape of the rotary valve may differ from the shape shown in each drawing 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]

[0060] 1. Powder and granular material transport system 30 Rotary Valve 31 Powder inlet 32 Powder outlet 40 Casing 41 Main casing 41a First inner surface 41b Second inner surface 50 rotors 51 rotor shaft 52 cores 53 Feather 54 Side panel 61 Motor 62 Power transmission section 411 First side wall 412 Second side wall 500 rotor body

Claims

1. A rotary valve that supplies powder or granular material from above to below, a casing having a powder inlet at an upper portion and a powder outlet at a lower portion; a rotor shaft extending along an axially extending rotation axis; a rotor body that rotates together with the rotor shaft and is housed inside the casing; and the rotor body is disposed below the powder inlet and above the powder outlet; The rotor body includes: A plurality of plate-shaped blades extending radially from the rotation axis and The casing comprises: a first inner surface facing an axial end surface of the rotor body with a small gap therebetween; a second inner surface facing the tip surface of the blade with a small gap therebetween; and The powder or granule is in a flake form, The rotary valve, wherein the first inner surface and the second inner surface are roughened.

2. 2. The rotary valve of claim 1, a rotary valve, wherein the axial end surface of the rotor body and the tip surface of the blade are roughened;

3. A rotary valve that supplies powder or granular material from above to below, a casing having a powder inlet at an upper portion and a powder outlet at a lower portion; a rotor shaft extending along an axially extending rotation axis; a rotor body that rotates together with the rotor shaft and is housed inside the casing; and the rotor body is disposed below the powder inlet and above the powder outlet; The rotor body includes: A plurality of plate-shaped blades extending radially from the rotation axis and The casing comprises: a first inner surface facing an axial end surface of the rotor body with a small gap therebetween; a second inner surface facing the tip surface of the blade with a small gap therebetween; and The powder or granule is in a flake form, a rotary valve, wherein the axial end surface of the rotor body and the tip surface of the blade are roughened;

4. The rotary valve according to any one of claims 1 to 3, The rotor body includes: two side plates, each of which is a circular plate, connected to both ends of the blades in the axial direction and perpendicular to the rotation axis; and A rotary valve, wherein an axial end surface of the rotor body is an outer surface of the side plate.

5. The rotary valve according to any one of claims 1 to 3, The rotary valve, wherein the roughening process is sandblasting with a sand diameter of 100 μm or more and 1 mm or less.

6. The rotary valve according to any one of claims 1 to 3, A rotary valve, wherein the powder is crushed material from PET bottles.

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