Stirring blade, stirring device and stirring method

Abstract

Provided are a stirring blade and the like capable of effectively applying a shear force to a fluid having a Reynolds number of 300 or more. The stirring blade (3) stirs a fluid (F) by rotating about a rotating shaft (30), the stirring blade (3) generates a flow of the fluid (F) having a Reynolds number of 300 or more, and in a 5% or more region of the flow, the ratio of a deformation velocity tensor to a velocity gradient tensor of the fluid, which is the sum of a deformation velocity tensor and a rotational velocity tensor, is 0.8 or more. The stirring blade (3) is provided with a plurality of plate-shaped members (311-314) capable of rotating at different positions in the radial direction perpendicular to the axial direction in which the rotating shaft (30) extends. The present invention is provided with two or more and five or less plate-shaped members (311-314) capable of rotating at two or more and five or less different radial positions.

Description

[0001] This application claims priority based on Japanese Patent Application No. 2024-155355, filed on September 9, 2024. The entire contents of that Japanese application are incorporated herein by reference. Technical Field

[0002] This invention relates to a stirring blade, etc. Background Technology

[0003] Patent document 1 discloses a stirring device having stirring blades that stir fluid contained in a longitudinally long stirring tank by rotating.

[0004] Patent Document 1: Japanese Patent Application Publication No. 11-276871

[0005] In such a stirring device, it is preferable to effectively apply shear force (deformation force) to the fluid in order to promote material movement. Conventionally, sufficient shear force has been applied to the fluid by extending the residence time of the fluid in the stirring tank, thus often resulting in a larger stirring tank length. In particular, it is difficult to effectively apply shear force to fluids with large inertial forces and Reynolds numbers above 300. Summary of the Invention

[0006] The present invention was made in view of the following situation, and its object is to provide a stirring blade or the like that can effectively apply shear force to fluids with a Reynolds number of 300 or higher.

[0007] To address the aforementioned issues, one embodiment of the present invention provides a stirring blade that stirs a fluid by rotating around a rotation axis. The stirring blade generates a fluid flow with a Reynolds number of 300 or higher, and in a region of 5% or more of this flow, the ratio of the deformation velocity tensor to the sum of the deformation velocity tensor and the rotational velocity tensor, i.e., the velocity gradient tensor of the fluid, is 0.8 or higher.

[0008] In this embodiment, for example, based on fluid analysis such as Computational Fluid Dynamics (CFD), when the object is limited to a flow region with a Reynolds number of 300 or higher, not only can the fluid be uniformly mixed, but also the ratio of deformation velocity tensor (0.8 or higher) and rotational velocity tensor (less than 0.2) that can efficiently apply shear force to the fluid to promote material movement are specifically identified. Furthermore, the proportion of regions or particles in the flow that should achieve these ratios (5% or higher) is determined, along with the structure or shape of the stirring blades that can achieve these values ​​with high probability. Thus, the specific structure or shape of the stirring blades that simultaneously achieves various values ​​can also be designed through simulations based on CFD, etc. Such stirring blades do not necessarily need to be complex; as shown in the following example, they can be constructed from a combination of simple plate-like components.

[0009] Another embodiment of the present invention is also a stirring blade. The stirring blade is a stirring blade that stirs a fluid by rotating about a rotation axis, wherein the stirring blade has two or more but less than five plate-shaped members that can rotate at two or more but less than five different positions in a radial direction perpendicular to the axis extending from the rotation axis, and the radial spacing between two radially adjacent plate-shaped members is 1.5 to 2.5 times the radial width of at least one of the plate-shaped members.

[0010] Another embodiment of the present invention is a stirring device. The device is a stirring device equipped with stirring blades that stir a fluid contained in a stirring tank by rotation, wherein the stirring blades generate a flow of fluid with a Reynolds number of 300 or more in the stirring tank, and in a region of more than 5% of the flow, the ratio of the deformation velocity tensor to the velocity gradient tensor of the fluid, which is the sum of the deformation velocity tensor and the rotational velocity tensor, is 0.8 or more.

[0011] Another embodiment of the present invention is a stirring method. The method is a stirring method for stirring a fluid contained in a stirring tank by rotating stirring blades, wherein the stirring blades generate a flow of fluid with a Reynolds number of 300 or more in the stirring tank, and in a region of more than 5% of the flow, the ratio of the deformation velocity tensor to the velocity gradient tensor of the fluid, which is the sum of the deformation velocity tensor and the rotational velocity tensor, is 0.8 or more.

[0012] Furthermore, any combination of the above-mentioned constituent elements or the conversion of these expressions into methods, apparatus, systems, recording media, computer programs, etc., are also included in this invention.

[0013] Invention Effects

[0014] According to the present invention, shear force can be applied efficiently to fluids with a Reynolds number of 300 or higher. Attached Figure Description

[0015] Figure 1 The structure of the stirring device according to the first embodiment is shown schematically.

[0016] Figure 2 The structure of the stirring device according to the second embodiment is shown schematically.

[0017] Figure 3 The structure of the stirring device according to the third embodiment is shown schematically.

[0018] Figure 4 This schematically illustrates a small stirring blade in a case where the stirring blade is composed of a combination of multiple small stirring blades.

[0019] Figure 5 An example of a CFD-based simulation of fluid F flow is shown.

[0020] Figure 6 An example of a CFD-based simulation of fluid F flow is shown.

[0021] Figure 7 This study schematically illustrates the number, size, and arrangement of one or more plate-shaped components in each stirring section that constitutes the stirring blade.

[0022] Figure 8 Showing about such Figure 7 The results of CFD-based simulations are shown in the representative study examples.

[0023] Figure 9 Schematic representation in Figure 7 In the preferred research example (a), the distribution of fluid particles in which the ratio of the observed or simulated deformation velocity tensor E is 0.8 or higher is an example.

[0024] Figure 10 Schematic representation in Figure 7 In the less preferred study example (b), the distribution of fluid particles in which the observed or simulated deformation velocity tensor E ratio is 0.8 or higher.

[0025] In the figure: 1-stirring device, 2-stirring tank, 3-stirring blade, 21-straight cylinder, 22-bottom, 30-rotating shaft, 31-stirring part, 311~314-plate-shaped parts. Detailed Implementation

[0026] Hereinafter, the embodiments for carrying out the present invention (hereinafter also referred to as embodiments) will be described in detail with reference to the accompanying drawings. In the following description and / or drawings, the same or equivalent constituent elements, components, and processes are labeled with the same symbols, and repeated descriptions are omitted. For ease of explanation, the proportions or shapes of the parts are appropriately set in the drawings, which are not intended to be limiting unless otherwise specified. The embodiments are examples and do not limit the scope of the present invention in any way. All features or combinations thereof presented in the embodiments are not necessarily essential features of the present invention. For convenience, the embodiments are presented after being broken down according to their functions and / or functional groups. However, a constituent element in an embodiment may actually be implemented by combining multiple constituent elements as separate entities, and multiple constituent elements in an embodiment may actually be implemented by a single constituent element as an integral entity. Furthermore, multiple embodiments or modifications may be disclosed in parallel, but any constituent elements of each embodiment and / or modification may be combined in any manner as long as they do not hinder each other's functions.

[0027] Figure 1 The structure of the stirring device 1 according to the first embodiment of the present invention is shown schematically. Figure 2 The structure of the stirring device 1 according to the second embodiment of the present invention is shown schematically. Figure 3 The structure of the stirring device 1 according to the third embodiment of the present invention is schematically shown. In these embodiments, the up-down direction (or longitudinal, height direction) in each figure is consistent with the vertical direction, and the left-right direction (or transverse, width direction) in each figure is consistent with the horizontal direction. Furthermore, the axial direction of the central axis of the stirring tank 2 and / or the rotation axis 30 of the stirring blade 3 described later is consistent with the up-down direction, i.e., the vertical direction, in each figure. Moreover, to clarify the diameter of the stirring tank 2 or the stirring blade 3, the left-right direction, i.e., the horizontal direction, is also referred to as the radial direction in each figure. In addition, the up-down direction, vertical direction, and axial direction in each figure may be different from each other. Similarly, the left-right direction, horizontal direction, and radial direction in each figure may be different from each other.

[0028] exist Figure 1 In the first embodiment, the stirring device 1 includes a stirring tank 2 containing a fluid F to be stirred, and stirring blades 3 for stirring the fluid F within the stirring tank 2 by rotation. The stirring tank 2 includes a cylindrical or tubular straight section 21 extending axially and a bottom 22 continuously disposed below the straight section 21. The capacity of the stirring tank 2 is arbitrary.

[0029] When viewed from above (axially), the inner circumferential wall or side wall of the cylindrical section 21 has a circular cross-section, and its diameter D represents the diameter of the stirring tank 2. Alternatively, the top-view cross-section of the cylindrical section 21 can also be any non-circular shape. In this case, the diameter D of the stirring tank 2 can be defined as the diameter of the inscribed circle of the cross-sectional shape of the cylindrical section 21, the diameter of the circumscribed circle of the cross-sectional shape, or the average or median of these diameters.

[0030] An opening for introducing fluid F into the mixing tank 2 is provided at the top of the cylindrical section 21. This opening is closed by a cover or the like during the stirring of fluid F by the stirring blades 3. Alternatively, fluid F can also be supplied into the mixing tank 2 from a supply port, such as a supply nozzle (not shown), which can be provided on the side wall of the cylindrical section 21.

[0031] The bottom 22 of the mixing tank 2 has a curved shape that protrudes downward from the lower end of the straight cylindrical portion 21. At the center of the bottom 22, the lowermost part of the mixing tank 2 is formed by the protruding end of the curved shape. In addition, the bottom 22 can be formed into an inverted cone shape or an inverted frustum shape with the diameter decreasing downward, or it can be formed into a plane with the axial direction as the normal direction.

[0032] At the bottom of the mixing tank 2, a discharge port (not shown) can be provided to discharge the stirred fluid F to the outside of the mixing device 1. This discharge port can be configured to be opened and closed by a valve or other discharge port opening and closing mechanism. For example, when the fluid F is added to and accumulated in the mixing tank 2, when the fluid F is stirred by the stirring blades 3, or when the concentration of the fluid F is homogenized, the discharge port is closed by a valve or other mechanism controlled to be in a closed state. Furthermore, when the stirred and homogenized fluid F is discharged as needed while being stirred by the stirring blades 3, the discharge port is opened by a valve or other mechanism controlled to be in an open state. In addition, the stirred fluid F can also be discharged from the opening with the cover at the top of the mixing tank 2 open. Furthermore, the stirred fluid F can also be discharged to the outside of the mixing tank 2 from a fluid discharge port such as a discharge nozzle that can be provided on the side of the straight section 21.

[0033] The horizontal boundary line between the generally cylindrical straight section 21 and the curved bottom 22 is also called the tangent TL. Furthermore, the vertical distance L between the lowest part of the stirring tank 2 (bottom 22) and the surface or liquid level LL of the fluid F within the stirring tank 2 is also called the liquid level height or reference height. In this embodiment, the axial liquid level height L of the fluid F is greater than the radial diameter D of the stirring tank 2. This longitudinally longer stirring tank 2 facilitates the formation of a flow of fluid F that circulates significantly in a generally vertical direction through the rotation of the stirring blades 3 and / or the circulation section 33 (described later). Figure 1(The arrows in the diagram illustrate this). Furthermore, when the bottom 22 is formed as a plane, the vertical distance L between the planar bottom 22 (base plate) and the liquid surface LL of the fluid F can be understood as the liquid surface height.

[0034] The stirring blade 3 is configured to rotate around a rotation axis 30 that is approximately aligned with the vertical central axis of the mixing tank 2. The stirring blade 3 is configured to rotate above the tangent TL, i.e., within the straight cylindrical portion 21 of the mixing tank 2. Although not shown in the figure, a rotation drive unit such as a motor that generates rotational power, or a rotational power conversion unit such as a gearbox or reducer that converts this rotational power into a desired rotational speed (or rotational velocity) or torque, may be provided above the rotation axis 30. A lower bearing (not shown) may be provided below the rotation axis 30. The rotational speed of the stirring blade 3 is arbitrary. Detailed structure of the stirring blade 3 will be described later.

[0035] Below the stirring blades 3 (specifically below the plate-shaped members 311-314 described later), preferably below the tangent TL, i.e., inside the bottom 22 of the mixing tank 2, a circulation section 33 is provided, capable of rotating around a rotation axis that is substantially aligned with the vertical central axis of the mixing tank 2. The circulation section 33 is separate from the stirring blades 3 and can rotate independently via a rotation axis (not shown) different from that of the stirring blades 3.

[0036] The circulation section 33 receives the flow from the upper part of the stirring blade 3 downwards and discharges it towards the outer periphery of the stirring tank 2. Thus, as schematically illustrated by the arrow, an upward flow of fluid F is formed along the inner periphery of the stirring tank 2. If this upward flow rises to near the liquid surface LL, it becomes a flow towards the inner periphery where the rotation shaft 30 is located, and then descends, supplying the upper part of the stirring blade 3. The fluid F, while descending, is stirred by the stirring blade 3 and then circulates extensively again within the stirring tank 2 through the circulation section 33. The circulation section 33, used to generate this circulating flow, can be, for example, composed of any discharge-type flow blade such as a paddle blade, turbine blade, or swept blade. The circulation section 33 can be integrally and continuously formed with the lower part of the plate-shaped components 311-314, described later.

[0037] exist Figure 2 In the second embodiment, instead of in Figure 1 In the first embodiment, a circulation unit 33 is used to generate a circulating flow within the stirring tank 2, and an external circulation mechanism 42, such as a pump, is provided outside the stirring tank 2 to circulate the fluid F. Figure 2 As indicated by the arrow, the fluid F is stirred by the stirring blades 3 as it descends and is then drawn out from the bottom 22 of the stirring tank 2. The fluid F is then lifted to the upper part of the straight section 21 of the stirring tank 2 by an external circulation mechanism 42 such as a pump, and is then reintroduced into the stirring tank 2 and supplied to the stirring blades 3 again.

[0038] exist Figure 3 In the third embodiment, without using Figure 1 The circulation section 33 in the first embodiment or Figure 2 In the second embodiment, the external circulation mechanism 42, etc., circulates the fluid F inside and outside the stirring tank 2, but in principle, the fluid F flows only once in a unidirectional direction from one end of the stirring tank 2, which is the longest dimension in the axial direction, to the other end. Figure 3 In this example, the stirring tank 2 is generally cylindrical or generally tubular in shape with an axial elongation. Preferably, the central axis of the stirring tank 2 coincides with the rotation axis 30 of the stirring blade 3.

[0039] A first fluid inlet 23, which in principle allows unidirectional flow of fluid F, is provided on the planar bottom 22 (i.e., bottom surface) of the mixing tank 2, and a second fluid inlet 25, which in principle allows unidirectional flow of fluid F, is provided on the planar top 24 (i.e., top surface) of the mixing tank 2. Figure 3 In the example, the first fluid port 23 serves as the fluid supply port, continuously supplying fluid F upwards; the second fluid port 25 serves as the fluid discharge port, continuously discharging fluid F upwards. This type of stirring tank 2 or stirring device 1, because it continuously supplies and discharges fluid F in a specific direction, can be called continuous.

[0040] Fluid F is agitated by stirring blades 3 as it enters the mixing tank 2 through the first fluid port 23 and exits through the second fluid port 25. Stirring blades 3, like the mixing tank 2, are elongated in the axial direction, having a height H that covers approximately all (e.g., more than 90%) of the total axial length (i.e., height) of the mixing tank 2. As described later, in this embodiment, the stirring blade 3 is constructed of a long, plate-like member extending axially, but it may also be composed of a plate-like member having a substantial height H that covers the entire height H of the stirring blade 3, or as... Figure 3 As schematically shown, the entire height H of the stirring blade 3 is covered by multiple plate-like components arranged axially, each having a height h significantly smaller than the height H. These plate-like components, regardless of their height and number, can rotate about a common axis of rotation 30.

[0041] Figure 4 It schematically shows when Figure 3 The stirring blade 3 of height H shown is composed of a plurality of smaller stirring blades 3 of height h (although not shown in the figure, substantially identical smaller stirring blades 3 are arranged axially above and / or below it). The following description of this smaller stirring blade 3 (hereinafter, for convenience, referred to as stirring blade 3) also applies. Figure 1 or Figure 2 The stirring blades 3 in the circulating stirring device 1 shown.

[0042] The stirring blade 3 is capable of extending axially with respect to the rotating shaft 30. Figure 4 Vertical radial direction (in the vertical direction) Figure 4 Multiple plate-shaped components 311-314, located at different radial positions in the left-right direction, rotate circumferentially (in a direction perpendicular to both the axial and radial directions) around a rotation axis 30. Each of the plate-shaped components 311-314 extends approximately parallel to each other along its axial direction. Figure 4 In the example, stirring sections 31, consisting of four plate-shaped components 311 to 314, are respectively provided on the left and right sides of the rotating shaft 30.

[0043] The number of stirring sections 31 is arbitrary, such as... Figure 4 As shown, there can be two, one, or more than three stirring units. To generate the most uniform possible flow of fluid F within the stirring tank 2, the multiple stirring units 31 are preferably arranged in a configuration viewed axially (…). Figure 4 The circumferential position (angle) symmetrical about the rotation axis 30 when viewed from above or below.

[0044] For example, in the case where two stirring sections 31 are provided, such as Figure 4 As shown, the two stirring sections 31 are preferably arranged in circumferential positions symmetrical about the rotation axis 30 (e.g., 0° position and 180° position). Furthermore, when four stirring sections 31 are provided, these four stirring sections 31 are preferably arranged in circumferential positions symmetrical about the rotation axis 30 (e.g., 0° position, 90° position, 180° position, 270° position). Thus, when an even number of stirring sections 31 are provided, as... Figure 4 As shown, it is preferably configured such that two opposing stirring sections 31 are linearly symmetrical about the rotation axis 30 in a plane containing the rotation axis 30.

[0045] The plurality of plate-shaped components 311 to 314 constituting each stirring section 31 are connected to each other by radially extending rod-shaped connecting components 32, and are able to rotate integrally about the rotation axis 30. The connecting components 32 are preferably as thin as possible so as not to obstruct the flow of fluid F mainly generated by the plate-shaped components 311 to 314.

[0046] The shape or size of each plate-shaped component 311 to 314 in each stirring section 31 is arbitrary, but it is preferable that the axial height h and the circumferential thickness are the same in all plate-shaped components 311 to 314. On the other hand, the radial widths w1 to w4 of each plate-shaped component 311 to 314 can be the same or different. Furthermore, the radial spacing g1 to g3 of each plate-shaped component 311 to 314 and / or the radial spacing g0 between the innermost first plate-shaped component 311 and the rotating shaft 30 (which is zero when the first plate-shaped component 311 extends directly from the rotating shaft 30) can be the same or different from each other. The three-dimensional dimensions, spacing, radial position, etc. of the plurality of plate-shaped components 311 to 314 in each stirring section 31 as described above are preferably adjusted or optimized according to fluid analysis such as computational fluid dynamics (CFD) to produce the desired flow described later.

[0047] In addition, such as Figure 3 As in the example, in Figure 4 When the small stirring blades 3 shown are arranged along the axial direction, the structures of the multiple small stirring blades 3 arranged at different axial positions can be substantially the same or different among all the small stirring blades 3. Furthermore, even when the three-dimensional dimensions, spacing, radial positions, etc., of the multiple plate-shaped members 311 to 314 constituting each stirring section 31 are substantially the same among all the small stirring blades 3, the radial positions of each stirring section 31 can be different, for example, between two adjacent small stirring blades 3 in the axial direction.

[0048] For example, suppose in such Figure 4 In a small stirring blade 3 having two stirring sections 31 as shown, each stirring section 31 is positioned at 0° and 180° when viewed axially. In this case, for example, in a small stirring blade 3 (not shown) located on the upper layer thereon, the two stirring sections 31 can be positioned at circumferential positions different from (or offset from) the 0° and 180° positions when viewed axially (e.g., 90° and 270°, 45° and 225°, 30° and 210°). This offset or offset of the rotational positions between the different small stirring blades 3 (e.g., 90°, 45°, 30°) can also be adjusted or optimized according to CFD or the like to produce the desired flow described later.

[0049] exist Figure 4In the process, the fluid F supplied from below (another small stirring blade 3 not shown or the first fluid port 23) is sheared or refined by the rotating small stirring blade 3 shown, and then further conveyed to above (another small stirring blade 3 not shown or the second fluid port 25). The flow of fluid F generated by the rotating stirring blade 3 can be simulated and modeled using fluid analysis based on CFD and other methods.

[0050] Figure 5 and Figure 6 An example of a CFD-based simulation of fluid F flow is shown. Figure 5 This is a diagram visualizing the velocity of fluid F using arrows (vectors) in a cross-section with the axial direction as the normal. In this simulation example, the three plate-shaped components 311–313 are radially ( Figure 5 Arranged in the vertical direction, and along the circumferential direction. Figure 5 The fluid (in the left direction) is driven by rotation, resulting in a rightward flow of fluid F. Fluid F flows from... Figure 5 The flow flows to the left into two gaps (hereinafter also referred to as slits) of the three plate-shaped components 311-313. At this time, the flow velocity is increased, so the arrows indicating the velocity locally become larger inside and / or at the outlet of each gap.

[0051] Figure 6 It will be with Figure 5 A diagram showing the vortices of fluid F generated by three identical plate-shaped components 311–313 (with the same height h and thickness t) visualized using arrows (as vector vorticity). It can be seen that large vortices are locally generated when fluid F flows through the two slits of the three plate-shaped components 311–313.

[0052] In this embodiment, CFD as described above was used to discover numerical parameters that enable the stirring blade 3 to efficiently stir or shear the fluid F when the object is limited to a flow region with a Reynolds number of 300 or higher. Furthermore, it was confirmed that the stirring blade 3 can be practically designed using CFD to meet these numerical parameters. In particular, it was confirmed that by adjusting… Figures 4-6 The various parameters shown (e.g., the height h, thickness t, width w1 to w4, and spacing g0 to g3 of each plate-shaped component) can actually be used to design stirring blades 3 that meet these numerical specifications.

[0053] Here, the density ρ (kg / m³) of fluid F is used. 3 The Reynolds number Re is defined according to the following formula: the rotational speed n (1 / s) of the stirring blade 3, the blade diameter d (m) of the stirring blade 3, and the viscosity μ (Pa·s) of the fluid F.

[0054] [Formula 1]

[0055]

[0056] Specifically, in this embodiment, in CFD, we focus on the velocity gradient tensor of the fluid F. Its constituent elements are the deformation velocity tensor E and the rotational velocity tensor Ω. The velocity gradient tensor of the fluid F. It is the sum of the deformation velocity tensor E and the rotational velocity tensor Ω (i.e., In the shearing or refining of fluid F, the deformation velocity tensor E, which controls the deformation of particles in fluid F, is crucial. Therefore, the velocity gradient tensor, which is the sum of the deformation velocity tensor E and the rotational velocity tensor Ω, is considered to be... In this context, it is important to increase the ratio of the deformation velocity tensor E (i.e., decrease the ratio of the rotational velocity tensor Ω).

[0057] In this embodiment, the ratio of this deformation velocity tensor E is defined by the following formula.

[0058] [Formula 2]

[0059]

[0060] This ratio is a value between 0 and 1; the larger the value (i.e., the closer it is to 1), the more dominant the deformation velocity tensor E becomes. In this embodiment, in CFD, the stirring blade 3 with the desired shear properties is achieved by focusing on fluid particles (or regions in the fluid F) with a ratio of 0.8 or higher.

[0061] Figure 7 Thirteen research examples (a) to (m) schematically illustrate the number, size, and arrangement of one or more plate-shaped components in each stirring section 31 constituting the stirring blade 3. In these figures, the vertical direction is radial, and a rotation axis 30 (not shown) exists below. Furthermore, the horizontal direction in these figures is the circumferential direction in which the stirring section 31 is driven to rotate. The black rectangles in each research example (a) to (m) schematically represent the plate-shaped components.

[0062] For example, in study example (a), the stirring section 31 moves from the inner circumferential side near the rotating shaft 30. Figure 7 Starting from the bottom of the axis of rotation, three plate-shaped members 311 to 313 are sequentially provided. Each plate-shaped member 311 to 313 has the same thickness t (e.g., 3 mm) and slightly different widths w1 to w3 (e.g., w2 < w1 < w3). Furthermore, of the two radial intervals g1 and g2 of the three plate-shaped members 311 to 313, the interval g1 (e.g., 9 mm to 11 mm) closer to the inner circumference of the axis of rotation 30 is greater than the interval g2 (e.g., 7 mm to 9 mm) on the outer circumference (i.e., g1 > g2).

[0063] Figure 8 Indicates about such Figure 7The CFD-based simulation results for representative examples are shown. In this simulation, the typical particle diameter of fluid F was set to 1 mm to 2 mm. On the horizontal axis, each example was categorized based on the number and configuration of slits. The stirring section 31 with slits "0" and... Figure 7 This corresponds to study example (b) which does not have a slit. The slit is the stirring section 31 "off the outer edge 1" (off the outer edge 1) and in Figure 7 The study example (e) corresponds to a slit that is biased towards the outer periphery. Additionally, although the illustration is omitted, in... Figure 7 The same results as in study (e) were obtained in study (f) where the slit is located on the inner circumferential side.

[0064] The slits are "uneven 2" (two unequally spaced) stirring section 31 and in Figure 7 The study example (a) corresponds to the configuration of the two slits with different intervals g1 and g2. Furthermore, although illustrations are omitted, the same research results as in study example (d) were obtained in study example (d) where the thickness t is smaller than that of study example (a) (for example, approximately half of the 3 mm in study example (a), i.e., approximately 1.5 mm). Moreover, although illustrations are omitted, the same research results as in study example (j) to (m) were obtained in study examples (j) to (m) where the two slits are configured differently from those in study example (a).

[0065] exist Figure 7 Although the stirring section 31 with slits "equally 2" (two equidistant slits) is not shown in the diagram, the widths g1 and g2 of the two slits in Study Example (a) are assumed to be equal. The stirring section 31 with slits "equally 3" (three equidistant slits) and... Figure 7 The study example (i) corresponds to the three slits arranged at substantially equal intervals. The stirring section 31 with "equal 4" (4 equidistant) slits corresponds to the... Figure 7 The study example (h) corresponds to the four slits arranged at substantially equal intervals. The stirring section 31 has "5 equidistant slits" (5 equidistant slits) and... Figure 7 The study example (g) corresponds to the five slits arranged at substantially equal intervals.

[0066] exist Figure 8 On the vertical axis, the proportion of fluid particles (or regions in the fluid F flow with a Reynolds number of 300 or higher) whose deformation velocity tensor E ratio is 0.8 or higher is shown among all particles contained in the flow of fluid F with a Reynolds number of 300 or higher (or regions in the fluid F flow with a deformation velocity tensor E ratio of 0.8 or higher). As mentioned above, fluid particles with a deformation velocity tensor E ratio of 0.8 or higher play a dominant role in the shearing or refining of fluid F; therefore, the higher this proportion, the higher the shearing or refining performance of the stirring section 31 or the stirring blade 3.

[0067] like Figure 8 As shown, in the research example (e) (and research example (f)) corresponding to "outer side 1", the research example (a) (and research examples (d), (j), (k), (l), (m)) corresponding to "inhomogeneous 2", the research example corresponding to "equal 2", the research example (i) corresponding to "equal 3", and the research example (h) corresponding to "equal 4", fluid particles with a ratio of 0.8 or more of 5% (0.05) or more of the fluid F with a Reynolds number of 300 or more can achieve this.

[0068] As described above, when the number of slits provided in the stirring section 31 is one or more but less than four, that is, when the number of plate-shaped members provided in the stirring section 31 is two or more but less than five, the proportion of fluid particles with a deformation velocity tensor E ratio of 0.8 or more can be increased, thus enabling the stirring blade 3 to achieve high shear performance. However, when the number of slits provided in the stirring section 31 is five or more, that is, when the number of plate-shaped members provided in the stirring section 31 is six or more, the width of each slit becomes narrower, thus preventing the effective flow of fluid F particles, and the deformation velocity tensor E ratio is not considered sufficiently increased.

[0069] Furthermore, in the research examples (a), (d), (e), (f), (h), (i), (j), (k), (l), and (m) above that obtained high shear performance, it was confirmed that: regarding radial ( Figure 7 The combination of two adjacent plate-shaped components in the vertical direction is such that the radial spacing is adjusted to be 1.5 to 2.5 times the radial width of at least one of the plate-shaped components. This is important for increasing the proportion of fluid particles with a deformation rate tensor E ratio of 0.8 or higher.

[0070] Furthermore, in the research examples (a), (d), (e), (f), (h), (i), (j), (k), (l), and (m) above that achieved high shear performance, it was confirmed that: each plate-shaped component exhibits high shear performance in the circumferential direction ( Figure 7 The thickness t in the left-right direction is adjusted to the radial direction of the stirring part 31 or the stirring blade 3. Figure 7 The total width (e.g., 30mm to 40mm) in the vertical direction is 2% to 10%, which is important for increasing the proportion of fluid particles with a deformation rate tensor E ratio of 0.8 or higher. Additionally, although figures are omitted, a larger value is taken when the thickness t exceeds this adjustment range. Figure 7 In the study example (c), fluid F loses energy as it passes through a circumferentially thick slit, so the proportion of fluid particles with a ratio of deformation velocity tensor E of 0.8 or higher is insufficient (less than 5%).

[0071] In the above research examples that achieved high shear performance, especially in research example (e) (and research example (f)) corresponding to "outer side 1", research example (a) (and research examples (d), (j), (k), (l), (m)) corresponding to "inhomogeneous 2" and research example (m) corresponding to "homogeneous 2", fluid particles with a ratio of deformation velocity tensor E of 0.8 or more were achieved in a significantly high proportion of 5.35% (0.0535) to 5.70% (0.0570) in the flow of fluid F with a Reynolds number of 300 or more.

[0072] Figure 9 Schematic representation in Figure 7 The preferred study example (a) shows the distribution of fluid particles with a deformation velocity tensor E ratio of 0.8 or higher, as observed or simulated. A single point in this figure represents a fluid particle with a deformation velocity tensor E ratio of 0.8 or higher. As mentioned above, the proportion of fluid particles with a deformation velocity tensor E ratio of 0.8 or higher in study example (a) is only slightly higher than 5% of the total, which is relatively small. Figure 9 In the example, the distribution of fluid particles with a ratio of deformation velocity tensor E greater than 0.8 appears to be significantly more than 5%, because this is due to the different axial directions ( Figure 9 Fluid particles observed in the region (perpendicular to the plane of the paper) overlap.

[0073] Figure 10 Schematic representation in Figure 7 In the less preferred study example (b), the distribution of fluid particles in which the observed or simulated deformation velocity tensor E ratio is 0.8 or higher is an example. Figure 9 Compared to the preferred research example (a), it can be seen that the number of fluid particles with a deformation velocity tensor E ratio of 0.8 or higher is significantly reduced. Thus, according to the preferred research example (a), the proportion of fluid particles with a deformation velocity tensor E ratio of 0.8 or higher in the flow of fluid F can be significantly increased, thereby significantly improving the stirring performance or shearing performance of the stirring section 31 or the stirring blade 3.

[0074] In the above examples, the flow region with a Reynolds number of 300 or higher was taken as the object, but the stirring blade 3 or stirring device 1 involved in the present invention can also be applied to the flow region with a Reynolds number of 1000 or higher.

[0075] The present invention has been described above according to embodiments. Various modifications exist in the combinations of constituent elements or processes in the exemplary embodiments, and such modifications are also included within the scope of the present invention, as will be apparent to those skilled in the art.

[0076] Furthermore, the configuration, function, and purpose of each device or method described in the embodiments can be implemented using hardware resources, software resources, or a combination of hardware and software resources. Hardware resources include, for example, processors, ROMs, RAMs, and various integrated circuits. Software resources include, for example, operating systems, application programs, and other programs.

Claims

1. An agitator blade that agitates a fluid by rotating around a rotation axis, wherein the agitator blade generates a flow of the fluid with a Reynolds number of 300 or more, and in 5% or more of a region in the flow, a ratio of a deformation rate tensor to a velocity gradient tensor of the fluid is 0.8 or more, the velocity gradient tensor being a sum of the deformation rate tensor and a rotation rate tensor.

2. The agitator blade according to claim 1, wherein the agitator blade generates a flow of the fluid with a Reynolds number of 1000 or more, and in 5% or more of a region in the flow, a ratio of the deformation rate tensor to the velocity gradient tensor is 0.8 or more.

3. The agitator blade according to claim 1, wherein the agitator blade generates a flow of the fluid with a Reynolds number of 300 or more, and in 5.35% to 5.70% of a region in the flow, a ratio of the deformation rate tensor to the velocity gradient tensor is 0.8 or more.

4. The agitator blade according to any one of claims 1 to 3, comprising a plurality of plate-like members rotatable at different positions in a radial direction perpendicular to an axial direction in which the rotation axis extends.

5. The agitator blade according to claim 4, comprising two or more and five or less of the plate-like members rotatable at different radial positions.

6. The agitator blade according to claim 4, wherein for a combination of two plate-like members adjacent in the radial direction, a spacing in the radial direction is 1.5 to 2.5 times a width in the radial direction of at least one of the plate-like members.

7. The agitator blade according to claim 4, wherein a thickness in a circumferential direction perpendicular to the axial and radial directions of each of the plate-like members is 2 to 10% of a total width of the agitator blade in the radial direction.

8. The agitator blade according to claim 4, comprising at least three of the plate-like members rotatable at different radial positions, wherein the spacing in the radial direction of the at least three plate-like members is larger as closer to an inner circumferential side of the rotation axis.

9. The agitator blade according to claim 4, wherein each of the plurality of plate-like members extends along the axial direction.

10. An agitator blade that agitates a fluid by rotating around a rotation axis, wherein the agitator blade comprises two or more and five or less of plate-like members rotatable at different positions in a radial direction perpendicular to an axial direction in which the rotation axis extends, and for a combination of two plate-like members adjacent in the radial direction, a spacing in the radial direction is 1.5 to 2.5 times a width in the radial direction of at least one of the plate-like members.

11. The agitator blade according to claim 10, wherein a circulation portion rotatable around the rotation axis is provided below the plate-like members.

12. An agitator device comprising an agitator blade that agitates a fluid accommodated in an agitator tank by rotating, wherein ​ ​ ​ ​ ​ ​ ​ ​ The stirring blade generates a flow of fluid in the stirring tank at a Reynolds number of 300 or more, in 5% or more of the regions in the flow, the ratio of a deformation velocity tensor to the sum of the deformation velocity tensor and a rotational velocity tensor in a velocity gradient tensor of the fluid is 0.8 or more.

13. A stirring method of stirring a fluid accommodated in a stirring tank by rotation of a stirring blade, wherein The stirring blade generates a flow of fluid in the stirring tank at a Reynolds number of 300 or more, in 5% or more of the regions in the flow, the ratio of a deformation velocity tensor to the sum of the deformation velocity tensor and a rotational velocity tensor in a velocity gradient tensor of the fluid is 0.8 or more.

Images