Rotational viscometer and fluid transport device

Abstract

A rotary viscometer 8 comprises: a measurement rotor 20 that contacts a fluid, the viscosity of which is to be detected; a rotating shaft 22 connected to the measurement rotor 20; a drive part 24 that rotates the measurement rotor 20 via the rotating shaft 22; a measurement part 26 that measures the viscosity of the fluid on the basis of a torque generated in accordance with rotation of the measurement rotor 20; a housing 18 for accommodating at least the measurement rotor 20, the rotating shaft 22, and the drive part 24; and a window part 28 provided in the housing 18 so that the rotating shaft 22 is observable from the outside.

Description

[Technical Field]

[0001] The present disclosure relates to a rotational viscometer and a fluid transfer device. [Background technology]

[0002] For example, in the field of manufacturing lithium ion secondary batteries and the like, a coating technique is known in which an electrode slurry containing an electrode active material is applied to the surface of a substrate such as a metal foil to form an electrode active material layer on the surface of the substrate. In such coating techniques, the viscosity of the electrode slurry is generally measured using a viscometer. A known example of such a viscometer is a rotational in-line viscometer (see, for example, Patent Document 1). A typical rotational viscometer rotates a measuring rotor submerged in a fluid whose viscosity is to be detected at a predetermined speed, and detects the viscosity of the fluid from the torque generated at that time. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-264789 Summary of the Invention [Problem to be solved by the invention]

[0004] The electrode active material in the electrode slurry tends to agglomerate. The agglomerates that form in the electrode slurry can interfere with the rotation of the measuring rotor to the extent that the specified rotation speed cannot be maintained. Viscosity measured when the rotation of the measuring rotor is impeded can be detected as an abnormal value. However, when managing the viscosity of a fluid using a conventional rotational viscometer, it is difficult for the manager to immediately determine whether the abnormal value is due to abnormal rotation of the measuring rotor or a change in the viscosity of the fluid.

[0005] The present disclosure has been made in light of these circumstances, and its purpose is to provide a technique for simplifying the management of fluid viscosity. [Means for solving the problem]

[0006] One aspect of the present disclosure is a rotational viscometer including a measurement rotor that contacts a fluid whose viscosity is to be detected, a rotating shaft connected to the measurement rotor, a drive unit that rotates the measurement rotor via the rotating shaft, a measurement unit that measures the viscosity of the fluid based on torque generated in response to the rotation of the measurement rotor, a housing that houses at least the measurement rotor, the rotating shaft, and the drive unit, and a window provided in the housing that allows the rotating shaft to be observed from outside.

[0007] Another aspect of the present disclosure is a fluid transporting device including a piping section through which a fluid whose viscosity is to be detected flows, and the rotational viscometer of the above aspect installed in the piping section.

[0008] Any combination of the above components, and conversion of the expression of the present disclosure into a method, device, system, etc., are also valid aspects of the present disclosure. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to simplify the management of fluid viscosity. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of a fluid transporting device according to an embodiment; [Figure 2] FIG. 1 is a perspective view of a rotational viscometer. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present disclosure will be described below with reference to preferred embodiments and drawings. The embodiments are illustrative and do not limit the present disclosure, and all features and combinations thereof described in the embodiments are not necessarily essential to the present disclosure. The same or equivalent components, parts, and processes shown in each drawing are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate. The scale and shape of each part shown in each drawing are set for convenience to facilitate explanation and should not be interpreted as limiting unless otherwise specified. Furthermore, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not indicate any order or importance, but are intended to distinguish one configuration from another. Furthermore, some components that are not important for explaining the embodiments are omitted from each drawing.

[0012] FIG. 1 is a schematic diagram of a fluid transporting device 1 according to an embodiment. The fluid transporting device 1 includes a tank 2, a piping section 4, a pump 6, and a rotational viscometer 8. The tank 2 stores a fluid whose viscosity is to be detected. In this embodiment, the fluid is an electrode slurry of a secondary battery. The electrode slurry is, for example, a mixture of a positive electrode active material or a negative electrode active material and a solvent. In the case of a typical lithium-ion secondary battery, the positive electrode active material is lithium cobalt oxide, lithium iron phosphate, or the like. The negative electrode active material is graphite, or the like.

[0013] The piping section 4 is connected to the tank 2. The fluid stored in the tank 2 flows through the piping section 4 and is transported to equipment for the next process (not shown), such as a coating device. The piping section 4 of this embodiment has a first pipe 10, a second pipe 12, and a third pipe 14. One end of the first pipe 10 is connected to the tank 2, and the other end is connected to a joint 16. One end of the second pipe 12 is connected to the joint 16, and the other end is connected to equipment for the next process. One end of the third pipe 14 is connected to the joint 16, and the other end is connected to the tank 2.

[0014] A pump 6 is installed in the first pipe 10. The pump 6 flows a fluid from the tank 2 into the pipe section 4. The pump 6 can be configured as a known pump such as a diaphragm pump. A rotational viscometer 8 is installed in the third pipe 14. The rotational viscometer 8 measures the viscosity of the fluid flowing through the third pipe 14 and sends the measurement result to a control device (not shown). Therefore, the rotational viscometer 8 of this embodiment is an inline type installed in the pipe section 4 through which the fluid flows. The rotational viscometer 8 may also be installed in the tank 2, etc. A fluid manager (a user of the rotational viscometer 8) can understand the viscosity of the fluid via the control device. The structure of the rotational viscometer 8 will be described in detail later.

[0015] The fluid stored in the tank 2 is sent to a joint 16 via a first pipe 10 by driving a pump 6. A portion of the fluid that reaches the joint 16 is sent to the equipment for the next process via a second pipe 12. Another portion of the fluid that reaches the joint 16 is returned to the tank 2 via a third pipe 14. The viscosity of the fluid is measured while passing through the third pipe 14. For example, most of the fluid is sent to the equipment for the next process via the second pipe 12, and a small amount of the fluid is sent to a rotational viscometer 8 via the third pipe 14 for viscosity measurement.

[0016] Next, the structure of the rotational viscometer 8 will be described in detail. Fig. 2 is a perspective view of the rotational viscometer 8. In Fig. 2, a portion of the housing 18 is cut away to show the internal structure of the rotational viscometer 8. The rotational viscometer 8 includes the housing 18, a measurement rotor 20, a rotating shaft 22, a drive unit 24, a measurement unit 26, a window unit 28, and a cover member 30.

[0017] The housing 18 has a lower housing 18a, an intermediate housing 18b, and an upper housing 18c. Although a cylindrical housing 18 is illustrated in FIG. 2, the shape of the housing 18 is not particularly limited. The housing 18 houses at least the measurement rotor 20, the rotation shaft 22, and the drive unit 24. In this embodiment, the measurement unit 26 is also housed in the housing 18. Note that the measurement unit 26 may be disposed outside the housing 18. The lower housing 18a is connected to the third pipe 14. The intermediate housing 18b connects the lower housing 18a and the upper housing 18c.

[0018] The lower housing 18a accommodates the measurement rotor 20 and one end of the rotating shaft 22. The lower housing 18a also has a fluid inlet 32 ​​and a fluid outlet 34 that communicate between the inside and outside of the housing 18. The fluid inlet 32 ​​is connected to the upstream side of the third pipe 14. The fluid outlet 34 is connected to the downstream side of the third pipe 14. The fluid flowing through the third pipe 14 flows into the lower housing 18a from the fluid inlet 32. The fluid in the lower housing 18a flows out into the third pipe 14 from the fluid outlet 34. This allows the measurement rotor 20 to come into contact with the fluid that has flowed into the lower housing 18a. For example, the measurement rotor 20 is immersed in the fluid filled in the lower housing 18a.

[0019] One end of the rotating shaft 22 is connected to the measurement rotor 20. The other end extends from the lower housing 18a through the middle housing 18b into the upper housing 18c. The measurement rotor 20 can rotate in conjunction with the rotation of the rotating shaft 22. The connection between the lower housing 18a and the middle housing 18b is sealed to prevent fluid in the lower housing 18a from flowing into the middle housing 18b.

[0020] The upper housing 18c accommodates the other end of the rotating shaft 22, the drive unit 24, and the measurement unit 26. The other end of the rotating shaft 22 is connected to the output shaft of the drive unit 24. The drive unit 24 rotates the measurement rotor 20 via the rotating shaft 22. The drive unit 24 can be configured with a known motor or the like. In this embodiment, the rotating shaft 22 has a coupling 36 between one end and the other end for transmitting the torque of the drive unit 24 to the measurement rotor 20. The coupling 36 is disposed within the upper housing 18c. As an example, the coupling 36 is configured as a so-called magnetic coupling and includes a drive magnet 38 and a driven magnet 40. The drive magnet 38 is fixed to the other end of the rotating shaft 22 (the drive unit 24 side), and the driven magnet 40 is fixed to one end of the rotating shaft 22 (the measurement rotor 20 side).

[0021] When a load equal to or less than the maximum torque transmittable by the coupling 36 acts on the measurement rotor 20 side of the rotating shaft 22, the drive magnet 38 and the driven magnet 40 rotate synchronously while substantially maintaining their relative positions in the rotational direction. This allows the torque of the drive unit 24 to be transmitted to the measurement rotor 20 via the rotating shaft 22, causing the measurement rotor 20 to rotate. On the other hand, if agglomerates or other impurities in the fluid impede the rotation of the measurement rotor 20, causing a load exceeding the maximum torque transmittable by the coupling 36 to act on the measurement rotor 20 side of the rotating shaft 22, the driven magnet 40 will no longer be able to follow the rotation of the drive magnet 38, and the connection between the drive magnet 38 and the driven magnet 40 will be severed. This prevents excessive load from being applied to the drive unit 24. The coupling 36 may be omitted, or two or more may be provided.

[0022] The measurement unit 26 measures the viscosity of the fluid based on the torque generated in response to the rotation of the measuring rotor 20. An example of the measurement unit 26 includes a torque sensor 42 and a viscosity calculation unit 44. The torque sensor 42 is connected to the drive unit 24 and detects the torque generated in the drive unit 24 when the measuring rotor 20 is rotated. The torque sensor 42 can be configured as a known sensor using a differential transformer or the like. The torque sensor 42 sends the detection result to the viscosity calculation unit 44.

[0023] The viscosity calculation unit 44 is realized as hardware by elements and circuits such as a computer CPU and memory, and as software by a computer program, etc. Those skilled in the art will understand that the viscosity calculation unit 44 can be realized in various forms by combining hardware and software. For example, the viscosity calculation unit 44 pre-stores a conversion table that associates torque with fluid viscosity. The viscosity calculation unit 44 also drives the drive unit 24 to rotate the measuring rotor 20 at a predetermined rotational speed. Based on the conversion table, the viscosity calculation unit 44 calculates the viscosity of the fluid from the torque detected by the torque sensor 42 when the measuring rotor 20 is rotating at the predetermined rotational speed. The viscosity calculation unit 44 sends the calculated viscosity to the control device.

[0024] As an example, the control device stores a viscosity threshold value in advance, and if the viscosity value calculated by the viscosity calculation unit 44 exceeds the threshold value, i.e., if the viscosity value is an abnormal value, the control device notifies the viscosity manager.

[0025] The housing 18 is provided with a window 28 so that the rotating shaft 22 can be observed from the outside. In this embodiment, the window 28 is provided in the upper housing 18c so that the coupling 36 of the rotating shaft 22 can be observed. Furthermore, the window 28 is provided so that the driven magnet 40 of the coupling 36, which is directly connected to the measurement rotor 20 side of the rotating shaft 22, can be observed. As an example, the window 28 is formed as a through-hole provided in the upper housing 18c. A fluid manager can understand the rotational state of the measurement rotor 20 by observing the rotational state (e.g., rotational speed, number of rotations, etc.) of the rotating shaft 22, more specifically, the rotational state of the coupling 36, through the window 28.

[0026] For example, when an abnormal viscosity value is measured, by observing the rotation state of the rotating shaft 22 through the window 28, it is possible to immediately determine whether the abnormal value is caused by abnormal rotation of the measurement rotor 20. Known methods such as optical methods and visual observation can be used to observe the rotation state. A sensor for detecting the rotation state of the rotating shaft 22 may be installed in the window 28. An example of a sensor for detecting the rotation state is a tachometer such as a non-contact laser measurement tachometer.

[0027] A lid member 30 is removably fitted into the window portion 28. By removing the lid member 30 from the window portion 28, a fluid manager can observe the state of the rotating shaft 22 (in this embodiment, the driven magnet 40) through the window portion 28. By covering the window portion 28 with the lid member 30 when not observing the rotating shaft 22, it is possible to prevent slurry powder and other foreign matter in the atmosphere from entering the housing 18 through the window portion 28. The material constituting the lid member 30 is not particularly limited, but a material with lower thermal conductivity than metal, such as resin, is preferable. This prevents the lid member 30 from becoming too hot even when the drive unit 24 generates heat. This improves safety and ease of operation when the manager removes the lid member 30.

[0028] As described above, the rotational viscometer 8 according to this embodiment includes the measurement rotor 20 that comes into contact with the fluid whose viscosity is to be detected, the rotating shaft 22 connected to the measurement rotor 20, the drive unit 24 that rotates the measurement rotor 20 via the rotating shaft 22, the measurement unit 26 that measures the viscosity of the fluid based on the torque generated in response to the rotation of the measurement rotor 20, the housing 18 that houses at least the measurement rotor 20, the rotating shaft 22, and the drive unit 24, and the window 28 provided in the housing 18 so that the rotating shaft 22 (the driven magnet 40 in this embodiment) can be observed from the outside.

[0029] This makes it easier to narrow down the cause of an abnormal viscosity measurement compared to conventional viscometers that do not have a window 28 and cannot observe the inside of the housing 18. This simplifies fluid viscosity management and improves fluid productivity. It also increases the reliability of the measurement values ​​of the rotational viscometer 8. Furthermore, it reduces the effort and time required to identify the cause of an abnormal value, thereby improving the productivity of products (electrode plates and batteries in this embodiment) manufactured using the fluid.

[0030] Furthermore, the rotational viscometer 8 of this embodiment is provided with a cover member 30 that is removably fitted into the window portion 28. Therefore, the window portion 28 can be kept covered when the rotating shaft 22 is not being observed. This reduces the risk of dust or the like entering the inside of the housing 18 and causing a breakdown of the rotational viscometer 8.

[0031] Furthermore, the rotational viscometer 8 of this embodiment is an in-line type that is installed in the piping section 4 (the third piping 14 in this embodiment) through which the fluid flows. This makes it possible to further increase the productivity of the fluid, and in turn the productivity of products manufactured using the fluid.

[0032] In this embodiment, the fluid whose viscosity is detected by the rotational viscometer 8 is electrode slurry for a secondary battery. Electrode slurry has a relatively high viscosity and is prone to forming agglomerates. This can easily impede the rotation of the measurement rotor 20. Therefore, when the fluid is electrode slurry, the rotational viscometer 8 according to this embodiment can more effectively simplify viscosity management. Note that the rotational viscometer 8 can also be used to measure the viscosity of fluids other than electrode slurry.

[0033] The embodiments of the present disclosure have been described in detail above. The above-described embodiments merely illustrate specific examples of implementing the present disclosure. The content of the embodiments does not limit the technical scope of the present disclosure, and many design modifications, such as changing, adding, or deleting components, are possible within the scope of the concept of the present disclosure defined in the claims. A new embodiment with design modifications will combine the effects of the combined embodiments and modifications. In the above-described embodiments, the content that allows such design modifications is emphasized by using notations such as "in this embodiment" or "in this embodiment," but design modifications are also permitted even in content without such notation. Any combination of the components included in each embodiment is also valid as an aspect of the present disclosure. Hatching on cross sections in the drawings does not limit the material of the hatched object.

[0034] The embodiments may be specified by the following items. [Item 1] a measuring rotor (20) that contacts a fluid whose viscosity is to be detected; a rotating shaft (22) connected to the measuring rotor (20); a drive unit (24) that rotates the measurement rotor (20) via a rotation shaft (22); a measuring unit (26) that measures the viscosity of the fluid based on the torque generated in response to the rotation of the measuring rotor (20); a housing (18) that accommodates at least a measurement rotor (20), a rotating shaft (22), and a drive unit (24); a window portion (28) provided in the housing (18) so that the rotating shaft (22) can be observed from the outside; Rotational viscometer (8). [Item 2] A cover member (30) is provided which is detachably fitted into the window portion (28). Item 1. A rotational viscometer (8) according to item 1. [Item 3] It is an in-line type that is installed in a piping section (4) through which a fluid flows. A rotational viscometer (8) according to item 1 or 2. [Item 4] The fluid is a secondary battery electrode slurry. A rotational viscometer (8) according to any one of items 1 to 3. [Item 5] The rotating shaft (22) has a coupling (36) for transmitting the torque of the drive unit (24) to the measuring rotor (20); The window (28) is provided to allow observation of the coupling (36). 5. A rotational viscometer (8) according to any one of items 1 to 4. [Item 6] a sensor installed in the window portion (28) for detecting the rotation state of the rotating shaft (22); 6. A rotational viscometer (8) according to any one of items 1 to 5. [Item 7] a piping section (4) through which a fluid whose viscosity is to be detected flows; and a rotational viscometer (8) according to any one of items 1 to 6, which is installed in the piping section (4). Fluid transport device (1). [Industrial Applicability]

[0035] The present disclosure can be used in rotational viscometers and fluid transport devices. [Explanation of symbols]

[0036] 1 fluid transport device, 2 tank, 4 piping section, 8 rotational viscometer, 18 housing, 20 measuring rotor, 22 rotating shaft, 24 drive section, 26 measuring section, 28 window section, 30 cover member

Claims

1. a measuring rotor that comes into contact with a fluid whose viscosity is to be detected; a rotating shaft coupled to the measurement rotor; a drive unit that rotates the measurement rotor via the rotation shaft; a measuring unit that measures the viscosity of the fluid based on a torque generated in response to rotation of the measuring rotor; a housing that accommodates at least the measurement rotor, the rotation shaft, and the drive unit; a window portion provided in the housing so that the rotation shaft can be observed from the outside, Rotational viscometer.

2. A cover member is provided which is removably fitted into the window portion.

2. The rotational viscometer according to claim 1.

3. An inline type that is installed in a piping section through which the fluid flows, 3. The rotational viscometer according to claim 1 or 2.

4. The fluid is an electrode slurry of a secondary battery.

4. The rotational viscometer according to claim 1.

5. the rotating shaft has a coupling for transmitting the torque of the drive unit to the measuring rotor; The window portion is provided so that the coupling can be observed.

5. The rotational viscometer according to claim 1.

6. a sensor installed in the window portion to detect the rotation state of the rotary shaft; 6. A rotational viscometer according to claim 1.

7. a piping section through which a fluid whose viscosity is to be detected flows; and the rotational viscometer according to any one of claims 1 to 6, which is installed in the piping section. Fluid transport device.

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