Stirring device and stirring method

Abstract

This stirring device 10 comprises: a stirring tank 12 that accommodates a fluid; a fluidizing blade 14 that causes the fluid to flow within the stirring tank 12 by rotating; and a shearing blade 16 that is provided between a bottom part 22 of the stirring tank 12 and the fluidizing blade 14, the shearing blade 16 stirring the fluid by rotating, and the shearing blade 16 being provided with a blade part 17 extending from a shearing blade rotating shaft 46 toward a side wall 12a of the stirring tank 12. At least a part (lower end part) of the fluidizing blade 14 rotates between a distal-end section of the blade part 17 and the side wall 12a of the stirring tank 12. The direction normal to the stirring surface of the blade part 17 is inclined with respect to both the axial direction of the shear blade rotating shaft 46 and the rotation direction of the blade part 17. The bottom part 22 of the stirring tank is a flat surface.

Description

Stirring device and stirring method

[0001] The present invention relates to a stirring device and the like.

[0002] Patent Document 1 discloses an agitation device for agitating a fluid in a mixing vessel, which includes a fluidizer and a disc-shaped shearing blade (dispersion blade). The dispersion blade, which is located at the center and in contact with the flow formed by the rotation of the fluidizer, effectively shears the fluid.

[0003] International Publication No. 2017 / 002905

[0004] Because the dispersing impeller in Patent Document 1 is disk-shaped, increasing the impeller diameter increases the load power and makes it difficult to maintain rotational balance. For this reason, the impeller diameter of the dispersing impeller in Patent Document 1 must be small. Specifically, as described in paragraph 0031 of Patent Document 1, the impeller diameter of the dispersing impeller is set to between 10% and 30% of the diameter of the mixing vessel. In this case, for example, if the viscosity of the fluid to be stirred by the mixing device increases, the impeller diameter of the dispersing impeller must be made smaller due to power issues, and there is a risk that the fluid will have difficulty reaching the small-diameter dispersing impeller.

[0005] The present invention has been made in view of the above circumstances, and has an object to provide a stirring device etc. that can effectively stir even highly viscous fluids or highly thixotropic fluids.

[0006] In order to solve the above problems, one embodiment of the stirring device of the present invention comprises a stirring tank that contains a fluid, a fluidizer that rotates to cause the fluid to flow within the stirring tank, and a stirring blade that is located between the bottom of the stirring tank and the fluidizer and stirs the fluid by rotating, and that has a blade portion that extends from its rotation axis toward the side wall of the stirring tank.

[0007] In this embodiment, by using a non-disk-shaped agitating impeller having blade portions extending from the rotation shaft toward the side wall of the agitation vessel, it is not necessary to reduce the blade diameter as in the disk-shaped dispersing impeller of Patent Document 1. The flow generated by the flow impeller can more easily reach the agitating impeller, which can be made larger in diameter than conventional ones, so even highly viscous fluids can be effectively agitated.

[0008] Another aspect of the present invention is a stirring method, which includes rotating a fluid impeller to cause a fluid to flow in a stirred tank, and rotating an impeller that is provided between the bottom of the stirred tank and the fluid impeller and has blades extending from its rotation axis toward a side wall of the stirred tank at a speed higher than that of the fluid impeller to stir the fluid.

[0009] Any combination of the above components and any conversion of these expressions into methods, devices, systems, recording media, computer programs, etc. are also encompassed by the present invention.

[0010] According to the present invention, even highly viscous fluids or highly thixotropic fluids can be effectively stirred.

[0011] It is a longitudinal cross-sectional view of the stirring device. It is a perspective view of a shear blade as seen from a schematic side. It is a top view or a bottom view of the shear blade. It is a perspective view of a shear blade rotation shaft.

[0012] Hereinafter, a mode for carrying out the present invention (hereinafter also referred to as an embodiment) will be described in detail with reference to the drawings. In the description and / or drawings, identical or equivalent components, members, processes, etc. will be assigned the same reference numerals, and redundant description will be omitted. The scale and shape of each part shown in the drawings are set for convenience to simplify the description, and should not be interpreted as limiting unless otherwise specified. The embodiment is an example and does not limit the scope of the present invention in any way. All features and combinations thereof described in the embodiment are not necessarily essential to the present invention.

[0013] FIG. 1 is a longitudinal cross-sectional view of an agitator 10 according to an embodiment of the present invention. In this embodiment, the agitator 10 is installed vertically, i.e., vertically or vertically in FIG. 1 . The terms "vertical," "vertical," and "vertical" are used interchangeably, and the terms "left-right," "lateral," and "horizontal" are also used interchangeably. The present invention is also applicable to an agitator 10 that is not installed vertically. In such cases, the terms "vertical," "vertical," and "vertical" are different from the vertical direction, and the terms "left-right," "lateral," and "horizontal" are different from the horizontal direction. Furthermore, as described below, the vertical, vertical, and vertical directions are also referred to as axial directions because the rotation axes of the blades, such as the flow impeller rotation shaft 34 of the flow impeller 14, the shear impeller rotation shaft 46 of the shear impeller 16, and the gate impeller rotation shaft 52 of the gate impeller 18, are provided in the vertical, vertical, and vertical directions. Furthermore, the left-right, horizontal, and horizontal directions are also referred to as radial directions because the left-right, horizontal, and horizontal directions determine the diameters of the agitator vessel 12, the flow impeller 14, the shear impeller 16, the gate impeller 18, etc.

[0014] The stirring device 10 includes a stirring tank 12 containing a fluid to be stirred, and rotors rotatable within the stirring tank 12 around axial rotation axes 34, 46, and 52, including a flow impeller 14, a shear impeller 16, and a gate impeller 18. The stirring tank 12 includes a cylindrical or tubular body portion 20 disposed at the top and extending in the axial direction, a bottom portion 22 disposed below and continuous with the body portion 20, and a top portion 24 disposed above and continuous with the body portion 20. In this embodiment, the bottom portion 22 of the stirring tank 12 is planar, with the axial direction as the normal direction. As will be described later, forming the bottom portion 22 planar has the advantage of reducing the axial distance from the shear impeller 16. However, the present invention is applicable to stirring tanks 12 having bottom portions 22 of any shape, such as curved surfaces or an inverted cone shape as described in Patent Document 1.

[0015] The planar bottom 22 of the stirring tank 12 can be attached to a flange 21 formed to protrude radially from the bottom or lowest portion of the cylindrical sidewall 12a or the body portion 20 of the stirring tank 12. That is, when assembling the stirring tank 12, the flat bottom 22 is brought into contact with the flange 21 of the body portion 20 from below and fixed with fasteners such as screws. In this case, the shear blades 16, shear blade rotation shaft 46, shear blade drive unit 47, etc., described below, may be attached to the bottom 22 in advance, or the shear blades 16, shear blade rotation shaft 46, shear blade drive unit 47, etc. may be attached to the bottom 22 after the bottom 22 is attached to the flange portion 21. In this way, forming the bottom 22 of the stirring tank 12 planar improves the assembly ease of the stirring tank 12 and the stirring device 10.

[0016] Like the bottom 22, the top 24 of the stirring tank 12 in this embodiment is flat, with the axial direction as the normal direction. The flat top 24 of the stirring tank 12 can be attached to a flange 23 formed to protrude radially from the cylindrical side wall 12a or the top or uppermost part of the straight body portion 20 of the stirring tank 12. That is, when assembling the stirring tank 12, the flat top 24 is brought into contact with the flange 23 of the straight body portion 20 from above and fixed with fasteners such as screws. In this case, the flow vane 14, the flow vane rotation shaft 34, the flow vane drive unit (not shown) provided at the top of FIG. 1, the gate vane 18, the gate vane rotation shaft 52, the gate vane drive unit (not shown) provided at the top of FIG. 1, and the like, which will be described later, may be attached to the top 24 in advance, or the flow vane 14, the flow vane rotation shaft 34, the flow vane drive unit, the gate vane 18, the gate vane rotation shaft 52, the gate vane drive unit, and the like may be attached to the top 24 after the top 24 is attached to the flange portion 23.

[0017] The inner peripheral wall or side wall 12a of the barrel portion 20 of the stirring tank 12 has a circular cross section in a top view, and its diameter D is hereinafter also referred to as the vessel diameter D. The cross section of the barrel portion 20 and / or the stirring tank 12 in a top view may be any non-circular shape. In this case, the vessel diameter D of the stirring tank 12 may be the diameter of the inscribed circle of the cross-sectional shape, the diameter of the circumscribed circle of the cross-sectional shape, or the average or intermediate value thereof. At least a portion of the upper part of the barrel portion 20 is open so that the fluid to be stirred can be introduced, and the opening can be closed with a lid or the like during stirring of the fluid by the stirring device 10. The fluid to be stirred may be supplied into the stirring tank 12 from a fluid supply port, such as a supply nozzle, provided on the side of the barrel portion 20.

[0018] The fluidizer 14, shear blade 16, and gate blade 18 are individually driven to rotate about their respective vertical rotation axes (the up-down direction in FIG. 1 ) by drive units such as motors and reducers provided outside the mixing vessel 12. The fluidizer rotation axis 34 of the fluidizer 14, the shear blade rotation axis 46 of the shear blade 16, and the gate blade rotation axis 52 of the gate blade 18 do not have to be aligned on the same line as in the example shown in FIG. 1 , and may rotate in different directions. The rotation directions and rotation speeds of the fluidizer 14, shear blade 16, and gate blade 18 can be set or controlled independently of one another, and are optimally set or controlled taking into account various conditions, such as the capacity and shape of the mixing vessel 12, the properties of the fluid in the mixing vessel 12, and the rate and phase of the chemical reaction to be initiated in the mixing vessel 12.

[0019] Typically, the rotational speed of the shear impeller 16, which is responsible for shearing and refining the fluid itself, fine particles in the fluid, and aggregates thereof, is greater than the rotational speed of the fluidizer 14 and / or gate impeller 18, which are responsible for fluid flow. For example, when the capacity of the agitator 12 is approximately 10 L, the typical rotational speed of the fluidizer 14 is 20-30 rpm, whereas the rotational speed of the shear impeller 16 is preferably approximately 1,200 rpm. Furthermore, when the capacity of the agitator 12 is approximately 1,000 L, the typical rotational speed of the fluidizer 14 is 20-30 rpm, whereas the rotational speed of the shear impeller 16 is preferably 600-900 rpm. Thus, the rotational speed of the shear impeller 16 is preferably at least 20 times the rotational speed of the fluidizer 14. In order to obtain shearing performance equivalent to that of the large-diameter shear blade 16 in this embodiment using the small-diameter dispersing blade in Patent Document 1, a rotational speed of approximately 3,600 rpm is required. As will be described later, with the shear blade 16 that can be made larger in diameter, the rotational speed required to obtain the desired shearing performance or micronization performance is reduced, so that the agitator 10 can be made smaller or less expensive by employing a low-power shear blade drive unit 47.

[0020] The fluidizer rotation shaft 34 of the fluidizer 14 is formed in a cylindrical or tubular shape, and the gate blade rotation shaft 52 of the gate blade 18 passes through it. The fluidizer rotation shaft 34 of the fluidizer 14 and the gate blade rotation shaft 52 of the gate blade 18 extend from the top 24 of the agitation tank 12 into the agitation tank 12. The fluidizer rotation shaft 34 is rotationally driven by a fluidizer drive unit (not shown) provided above in Figure 1, and the gate blade rotation shaft 52 is rotationally driven inside the fluidizer rotation shaft 34 by a gate blade drive unit (not shown) provided above in Figure 1. The fluidizer drive unit and the gate blade drive unit are preferably configured by different motors, but are preferably configured integrally as a single drive unit including the multiple motors.

[0021] A shear blade rotation shaft 46 of the shear blade 16 serving as an agitator blade extends from the bottom 22 of the agitator tank 12 into the agitator tank 12. The shear blade rotation shaft 46 is driven to rotate by a shear blade drive unit 47 provided at the bottom of Fig. 1. The drive unit below the agitator tank 12 that constitutes the shear blade drive unit 47 is different from the drive units above the agitator tank 12 that constitute the flow blade drive unit and / or gate blade drive unit described above.

[0022] The fluidizer 14 rotates around the fluidizer rotation shaft 34 by a fluidizer drive unit, causing the fluid to flow within the stirred tank 12. The fluidizer 14 in the illustrated example is a pair of ribbon blades formed in a spiral shape around the fluidizer rotation shaft 34 in the vertical direction. Note that the shape of the fluidizer 14 is not limited to a spiral or ribbon shape, but it is preferable that the shape of the fluidizer 14 has as little of a portion adjacent to the bottom 22 as possible in order to ensure sufficient space for installing the shear blades 16 (described later) in the area facing the bottom 22 of the stirred tank 12. For this reason, the ribbon blades in the illustrated example are preferable to anchor blades shaped to fit the bottom 22.

[0023] In the illustrated example, the ribbon impeller faces the bottom 22 at a location close to the sidewall 12a of the agitation vessel 12. However, as described below, the shear impeller 16 is installed in the radially central region of the agitation vessel 12 (the region centered on the rotation axis, such as the shear impeller rotation axis 46), so the flow impeller 14 (ribbon impeller) and the shear impeller 16 (agitation impeller) do not interfere with each other. The bottom 22 of the agitation vessel 12 often has an outlet through which the fluid to be stirred settles and the agitated fluid is discharged. Therefore, a careful balance is required between the flow caused by the flow impeller 14 and the shear (agitation) caused by the shear impeller 16. As shown in the illustrated example, the flow impeller 14 rotates in the outer peripheral region of the bottom 22, and the shear impeller 16 rotates in the central region of the bottom 22, thereby improving the quality of the agitated fluid at the bottom 22. Furthermore, because the flow impeller 14 is present only in the outer peripheral region of the bottom 22, the shear impeller 16 can be made larger in diameter in the central region of the bottom 22.

[0024] When the fluidizer 14 rotates integrally with the fluidizer rotating shaft 34 by the fluidizer drive unit, an induced flow is formed that flows downward along the side wall 12a of the straight body portion 20. The fluid in the mixing vessel 12 that is carried by this induced flow moves to the bottom 22 and is led from the outer peripheral region to the central region where the shear blades 16 are located, where it is efficiently sheared or stirred.

[0025] The flow vane 14 comprises a plurality of band-shaped flow vane bodies 26 (two in the example of FIG. 1 ) each having a predetermined width, and a plurality of support rods 28 (two in the example of FIG. 1 ) that engage with the inner periphery of each flow vane body 26 at its upper and lower ends. The plurality of flow vane bodies 26 and the plurality of support rods 28 are combined as shown and integrated by welding or the like. Each support rod 28 is a rod-shaped member extending in the axial direction, and the upper and lower ends of each flow vane body 26 are engaged with and supported.

[0026] 1 , in which two support rods 28 and two flow vane bodies 26 are provided, the first support rod 28 is engaged above with the upper end of the upper wing 36 of the first flow vane body 26, and below with the lower end of the lower wing 38 of the second flow vane body 26. Similarly, the second support rod 28 is engaged above with the upper end of the upper wing 36 of the second flow vane body 26, and below with the lower end of the lower wing 38 of the first flow vane body 26. In this way, the flow vane bodies 26 engaged above and below each support rod 28 are different from each other. In other words, each support rod 28 is engaged with a plurality of different flow vane bodies 26, and each flow vane body 26 is engaged with a plurality of different support rods 28.

[0027] 1 , other (e.g., two) support rods 28 may be provided at intermediate positions on the same circumference as the two support rods 28 shown in Fig. 1 . These two support rods 28 provided at the front and rear of the paper surface of Fig. 1 support or guide the axial center portion of each flow vane body 26, indicated by O, from the inside, thereby maintaining each flow vane body 26 in the desired spiral shape. The upper end of each support rod 28 is connected to a flow vane rotation shaft 34 extending vertically. When a flow vane drive unit (not shown) drives and rotates the flow vane rotation shaft 34, the flow vanes 14, consisting of the support rods 28 and flow vane bodies 26 connected to each other, rotate together, and the aforementioned downward induced flow is formed.

[0028] The two flow vane bodies 26, which are formed in a spiral belt shape as a whole, are formed point-symmetrically about the flow vane rotation axis 34 in top view. Each flow vane body 26 is formed so as to rotate 180 degrees about the flow vane rotation axis 34 in top view. Therefore, as described above, the upper end of each flow vane body 26 engages with one support rod 28, and the lower end of each flow vane body 26 engages with the other support rod 28 that is located in a position point-symmetrical to one support rod 28 (a 180-degree rotational position) about the flow vane rotation axis 34 in top view.

[0029] A gate vane 18, which serves as an auxiliary vane or inner vane and has a smaller diameter than the fluidizer vane 14, is installed radially toward the center or inside of the fluidizer vane 14. The gate vane 18 is driven to rotate around a gate vane rotation shaft 52 by a gate vane drive unit, and causes the fluid to flow inside the fluidizer vane 14 in a manner different from that of the fluidizer vane 14 within the agitation tank 12. Note that, because a shear vane 16 (described later) is installed below the gate vane 18, the axial distance between the bottom 22 of the agitation tank 12 and the gate vane 18 (lower member 48D (described later)) is greater than the installation space or installation height of the shear vane 16. In other words, the space below the gate vane 18 can be utilized to the fullest extent by the shear vane 16.

[0030] The gate blade 18 includes a gate blade main body 48 in the shape of a rectangular frame that is line-symmetrical about a vertical rotation axis (gate blade rotation axis 52), and an axial gate blade rotation axis 52 that is connected to the upper part of the gate blade main body 48 and is rotationally driven by a gate blade drive unit (not shown). The gate blade main body 48 has a frame structure in which a radial upper member 48U, an axial left member 48L, an axial right member 48R, and a radial lower member 48D, each of which is formed in a rod or column shape, are integrated into a rectangular shape. The rotation direction and rotation speed of the gate blade 18 are arbitrary, but typically the gate blade 18 rotates in the opposite direction to the flow blade 14, or in the same direction as the flow blade 14 at a different speed or rotational speed.

[0031] Rotating the fluidizer 14 and the gate blade 18 in different directions and / or at different speeds creates a difference between the speed at which the material moves as the fluidizer 14 rotates and the speed at which the material moves as the gate blade 18 rotates. This prevents the material in the stirred tank 12 from rotating together with the fluidizer 14, thereby efficiently moving the material within the stirred tank 12. Furthermore, by appropriately setting the rotation direction and / or rotation speed of the gate blade 18, a flow can be generated that moves the material sheared by the shear blade 16 below the gate blade 18 upward. The induced flow generated by the gate blade 18 and flowing upward through the center of the stirred tank 12 is then transformed by the fluidizer 14 into an induced flow flowing downward along the sidewall 12a of the stirred tank 12, and then directed back toward the shear blade 16. A circulating flow is thus formed between the fluidizer 14, the shear blade 16, and the gate blade 18, allowing the material to be efficiently stirred.

[0032] The shear blade 16, which serves as an agitator blade and is provided between the bottom 22 of the agitator vessel 12 and the fluidizer blade 14, is rotated around the shear blade rotation shaft 46 by a shear blade drive unit 47 to shear or agitate the fluid in the agitator vessel 12. The shear blade 16 has a pair of blade portions 17A, 17B (hereinafter also collectively referred to as blade portions 17) that extend radially from the shear blade rotation shaft 46 toward the side wall 12a of the agitator vessel 12.

[0033] In the radial direction (left-right direction), the blade portion 17 is disposed in a central region closer to or inside the center than the lower end of the fluidizer blade 14, which rotates around the outer periphery of the stirred tank 12 or the bottom 22. Therefore, at least a portion (lower end) of the fluidizer blade 14 rotates between the tip of the blade portion 17 (the left end and right end in FIG. 1 ) and the side wall 12a of the stirred tank 12 without interfering with the blade portion 17. In addition, in the axial direction (up-down direction), the blade portion 17 is disposed between the upper gate blade 18 and the lower bottom 22 of the stirred tank 12. That is, the blade portion 17 is disposed in a central region facing the bottom 22 of the stirred tank 12. As mentioned above, since the bottom 22 of the stirring tank 12 in this embodiment is flat, the shear blades 16 having blade portions 17 extending radially approximately parallel to it can be efficiently or compactly arranged in an approximately rectangular parallelepiped area surrounded by the upper gate blades 18, the left-right flow blades 14 (lower ends), and the bottom 22 of the stirring tank 12 below.

[0034] FIG. 2 is a schematic side perspective view of the shear blade 16, and FIG. 3 is a top view or bottom view of the shear blade 16. The shear blade 16 includes a cylindrical boss 161 whose height direction is the axial direction (the up-down direction in FIG. 2 ) and a pair of wing portions 17A and 17B (wing portions 17) extending radially from the boss 161 (the left-right direction in FIGS. 2 and 3 ). An axial mounting hole 46A is provided in the radial center of the boss 161, into which the shear blade rotation shaft 46 is inserted for mounting. As shown in FIG. 3 , the mounting hole 46A is provided in the center of a recess 46B having a substantially rectangular or substantially square cross section. When the recess 46B is provided on the lower surface of the boss 161, a protrusion 46C ( FIG. 4 ) that engages or fits with the recess 46B is provided on the upper end of the substantially cylindrical shear blade rotation shaft 46. In top view, the cross-sectional shape of the convex portion 46C is substantially rectangular or substantially square, and is the same as or slightly smaller than the cross-sectional shape of the concave portion 46B. Furthermore, in top view, a mounting hole 46D communicating with the mounting hole 46A of the boss 161 is provided in the center of the convex portion 46C. With the convex portion 46C at the top of the shear blade rotation shaft 46 inserted into the concave portion 46B at the bottom of the boss 161, the shear blade rotation shaft 46 and the shear blade 16 (boss 161) are fixed by screws (not shown) fastened to the mounting holes 46A and 46D. Therefore, the shear blade rotation shaft 46 and the shear blade 16 can rotate integrally.

[0035] The blade 17 is fixed to the boss 161 by welding, for example. The blade 17 may also be fixed directly to the shear blade rotation shaft 46 by welding, without using the boss 161. The normal direction of the stirring surface (surface) of each flat blade 17A, 17B is inclined with respect to both the axial direction of the shear blade rotation shaft 46 (the vertical direction in FIG. 2 ) and the rotation direction of each blade 17A, 17B (the direction of rotation around the shear blade rotation shaft 46). A stirring blade or shear blade equipped with such a blade 17 is sometimes called an inclined paddle blade. For example, it is preferable that the angle between the normal direction of the stirring surface of each blade 17A, 17B and the axial direction of the shear blade rotation shaft 46 is 15 degrees or less (the angle between the normal direction and the rotation direction of each blade 17A, 17B and the axial direction of the shear blade rotation shaft 46 is 75 degrees or more). As a result, the agitation surfaces of the blades 17A and 17B become substantially parallel to the bottom 22 of the agitation tank 12 (forming an angle of 15 degrees or less), thereby reducing the resistance that the agitation surfaces receive from the fluid during rotation. Therefore, even if the blades 17 are made larger in diameter, they can be driven with relatively low power, preventing the shear blade drive unit 47 from becoming larger and becoming more expensive. In addition, by inclining the blades 17 as described above, the blades 17 are less likely to spin idle even with fluids that are highly thixotropic or have low spinnability, thereby improving shearing efficiency or micro-pulverization efficiency.

[0036] The non-disk-shaped shear blades 16 or blade portions 17 have a relatively small load power, allowing for a large blade diameter. Furthermore, their light weight facilitates rotational balance. Therefore, the blade diameter in the extension direction of the blade portions 17 (the radial distance between the left end of blade portion 17A and the right end of blade portion 17B in FIGS. 2 and 3 ) can be between 35% and 85% of the diameter D of the stirred tank 12, preferably between 45% and 75%, and more preferably between 50% and 70% of the diameter D of the stirred tank 12. This allows for a larger shear area than conventional disk-shaped stirring blades, improving shear efficiency and pulverization efficiency.

[0037] Furthermore, conventional disk-shaped impellers (e.g., the Disper impeller of Patent Document 1) divide the interior of the agitation vessel into upper and lower sections due to the disk portion, significantly impeding fluid flow. This tends to cause liquid pooling below the disk portion, particularly with highly viscous solutions. In contrast, according to the present embodiment, by utilizing a non-disk-shaped shear impeller 16 having a blade portion 17 extending from the shear impeller rotation shaft 46 toward the sidewall 12a of the agitation vessel 12, the interior of the agitation vessel 12 is not divided into upper and lower sections as with conventional disk-shaped impellers. Therefore, even if the blade diameter of the blade portion 17 of the shear impeller 16 is increased, the fluid flow generated by the flow impeller 14 and gate impeller 18 is not significantly impeded. Thus, the shear impeller 16, which can be made larger than conventional impellers, is more easily reached by the flow generated by the flow impeller 14 and gate impeller 18, effectively shearing or agitating even highly viscous fluids.

[0038] As described above, the shear blade 16 or the entire agitation device 10 of this embodiment is suitable for shearing and atomizing relatively high-viscosity fluids (fluids with a viscosity of at least 1,000 cP or more, e.g., 10,000 cP or more). Examples of such high-viscosity fluids include any fluid containing fine particles such as carbon black or silica (oil, varnish, rubber, polymer solution, molten resin, etc.). Fine particles such as carbon black tend to form agglomerates in the fluid, but are efficiently atomized and / or dispersed by the shear blade 16 of this embodiment.

[0039] In order to obtain suitable shearing or atomization performance for such high-viscosity fluids, the width w (FIG. 3) of the tip of the blade portion 17 in the rotation direction is preferably 5% or less of the diameter D of the stirred tank 12. Furthermore, in order to obtain the desired mixing performance at the bottom 22 of the stirred tank 12, where the fluid to be stirred settles and where an outlet for discharging the stirred fluid is often provided, the distance h (FIG. 1) between the blade portion 17 and the bottom 22 of the stirred tank 12 is preferably 15% or less of the diameter D of the stirred tank 12.

[0040] The present invention has been described above based on the embodiments. Various modifications are possible to the combinations of the components and processes in the exemplary embodiments, and it will be obvious to those skilled in the art that such modifications are included within the scope of the present invention.

[0041] For example, the shape of the agitating blade of the present invention is not limited to the shape of the shear blade 16 exemplified in the embodiment. In order to obtain at least part of the effects of the present invention, the agitating blade provided between the bottom of the agitating vessel and the fluidizing blade may be a non-disk shape having one or more blade portions extending from its rotation axis toward the side wall of the agitating vessel.

[0042] The configuration, operation, and function of each device and method described in the embodiments can be realized by hardware resources, software resources, or a combination of hardware and software resources. Examples of hardware resources include processors, ROM, RAM, and various integrated circuits. Examples of software resources include operating systems, applications, and other programs.

[0043] The present invention relates to a stirring device and the like.

[0044] 10 Stirring device, 12 Stirring tank, 12a Side wall, 14 Flow impeller, 16 Shear impeller, 17 Blade portion, 18 Gate impeller, 20 Straight body portion, 21 Flange portion, 22 Bottom portion, 34 Flow impeller rotating shaft, 46 Shear impeller rotating shaft, 47 Shear impeller driving portion, 52 Gate impeller rotating shaft.

Claims

1. A mixing vessel for containing a fluid; A fluidizer that rotates to cause the fluid to flow in the mixing tank; an agitating blade provided between the bottom of the agitating tank and the fluidizing blade, which agitates the fluid by rotation, the agitating blade having a flat blade portion extending from its rotation axis toward a side wall of the agitating tank; Equipped with The normal direction of the stirring surface of the flat blade portion is inclined with respect to both the axial direction of the rotating shaft and the rotation direction of the blade portion, The blade diameter in the extension direction of the flat blade portion is between 50% and 70% of the vessel diameter of the stirring vessel. Mixing device.

2. The stirring device according to claim 1 , wherein at least a portion of the flow impeller rotates between a tip of the impeller and a side wall of the stirring tank.

3. The stirring blade has a boss, The flat wing portion extends radially from the boss, An axial mounting hole into which the rotating shaft is inserted is provided at the radial center of the boss, The mounting hole is provided in a recess having a rectangular or square cross section. The stirring device according to claim 1 or 2.

4. 4. The stirring device according to claim 3, wherein an angle between a normal direction of the stirring surface of the blade portion and the axial direction is 15 degrees or less.

5. The stirring device according to claim 1 or 2, wherein the viscosity of the fluid is at least 1,000 cP or more.

6. 3. The stirring device according to claim 1, wherein a width of the tip of the blade portion is 5% or less of a diameter of the stirring tank.

7. 3. The stirring device according to claim 1, wherein a distance between the blade portion and a bottom of the stirring vessel is 15% or less of a diameter of the stirring vessel.

8. The bottom of the stirring tank is flat, The flat wing portion extends parallel to the bottom portion. The stirring device according to claim 1 or 2.

9. 9. The stirring device according to claim 8, wherein the planar bottom of the stirring vessel is attachable to a flange portion formed at the bottom of a cylindrical side wall of the stirring vessel.

10. 3. The stirring device according to claim 1, wherein the rotation axis of the stirring blade extends from a bottom of the stirring tank into the stirring tank.

11. 3. The stirring device according to claim 1, wherein the rotation axis of the fluidizing blade extends from a top of the stirring vessel into the stirring vessel.

12. The stirring device according to claim 1 or 2, wherein a rotation speed of the stirring blade is greater than a rotation speed of the flow blade.

13. 3. The stirring device according to claim 1, wherein the rotation axis of said stirring blade and the rotation axis of said flow blade are arranged on substantially the same straight line.

14. Rotating the fluid impeller to cause the fluid to flow in the mixing tank; agitating the fluid by rotating an agitating blade provided between the bottom of the agitating tank and the fluidizer and having a flat blade portion extending from its rotation axis toward a side wall of the agitating tank at a higher speed than the fluidizer; A stirring method comprising: The normal direction of the stirring surface of the flat blade portion is inclined with respect to both the axial direction of the rotating shaft and the rotation direction of the blade portion, The blade diameter in the extension direction of the flat blade portion is between 50% and 70% of the vessel diameter of the stirring vessel. Stirring method.