Stirring device

Abstract

To provide a stirring device and a stirring blade that can effectively miniaturize fluid and particles in fluid with ultrasonic waves.SOLUTION: A stirring device 1 comprises: a stirring tank 2 that stores fluid; a stirring blade 3 that stirs fluid in the stirring tank 2 by rotating; and an ultrasonic wave oscillating part 4, arranged close to the stirring blade 3 in the stirring tank 2, which oscillates ultrasonic waves. In a cross section which is perpendicular to a rotating shaft 31 of the stirring blade 3, a closest approach distance (G) between the stirring blade 3 and the ultrasonic wave oscillating part 4 is equal to 3% of a tank diameter D of the stirring tank 2 or less. The fluid includes carbon black and has viscosity of 100 cp or higher. The ultrasonic wave oscillating part 4 is mounted on a side wall of the stirring tank 2 and is extended along a shaft direction which is parallel to the rotating shaft 31 of the stirring blade 3. The ultrasonic wave oscillating part 4 is arranged close to the stirring blade 3, at an inner periphery side close to the rotating shaft 31 of the stirring blade 3.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an agitation device and the like.

Background Art

[0002] Patent Document 1 discloses an agitation device including an agitation blade that agitates a fluid in an agitation tank by rotation and an ultrasonic oscillation unit that oscillates ultrasonic waves in the agitation tank. The fluid in the agitation tank mixed by the agitation blade is effectively miniaturized by the ultrasonic oscillation unit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the agitation device of Patent Document 1, the flow of the fluid generated by the agitation blade is guided to the ultrasonic oscillation unit. However, for example, when the viscosity of the fluid increases, the flow generated by the agitation blade may attenuate, and there is a risk that the fluid will hardly reach the ultrasonic oscillation unit. Also, the ultrasonic waves oscillated by the ultrasonic oscillation unit may be likely to attenuate in, for example, a high-viscosity fluid.

[0005] The present invention has been made in view of such a situation, and an object thereof is to provide an agitation device or the like that can effectively miniaturize a fluid or particles in the fluid by ultrasonic waves.

Means for Solving the Problems

[0006] To solve the above problems, an agitator according to one aspect of the present invention comprises an agitator tank for containing a fluid, an agitator blade for agitating the fluid in the agitator tank by rotation, and an ultrasonic emitting unit positioned close to the agitator blade in the agitator tank for emitting ultrasonic waves.

[0007] In this embodiment, since the ultrasonic oscillator is positioned close to the stirring blades in the stirring tank, the fluid and particles in the fluid can be effectively miniaturized by ultrasound.

[0008] Another aspect of the present invention is an agitator blade. This agitator blade is used to agitate a fluid in a stirring tank by rotation, and has a shape that does not come into contact with an ultrasonic emitting unit that emits ultrasonic waves in the stirring tank, but is rotatable in the vicinity thereof.

[0009] Furthermore, any combination of the above components, as well as methods, apparatus, systems, recording media, computer programs, etc., derived from these representations, are also included in the present invention. [Effects of the Invention]

[0010] According to the present invention, fluids and particles within a fluid can be effectively miniaturized using ultrasound. [Brief explanation of the drawing]

[0011] [Figure 1] This is a longitudinal cross-sectional view of the stirring device. [Figure 2] A schematic cross-section of the stirring tank viewed from above is shown. [Figure 3] A first modified example of the stirring blade and ultrasonic oscillator is shown. [Figure 4] A second modified example of the stirring blade and ultrasonic oscillator is shown. [Figure 5] A third modified example of the stirring blade and ultrasonic oscillator is shown. [Figure 6] A fourth modified example of the stirring blade and ultrasonic oscillator is shown. [Modes for carrying out the invention]

[0012] The following describes in detail embodiments (hereinafter also referred to as "models") for carrying out the present invention, with reference to the drawings. In the description and / or drawings, identical or equivalent components, members, processes, etc., are denoted by the same reference numerals, and redundant descriptions are omitted. The scale and shape of each part shown in the drawings are set for convenience to simplify the description and are not to be interpreted restrictively unless otherwise specified. The embodiments are illustrative and do not limit the scope of the present invention in any way. Not all features or combinations thereof described in the embodiments are necessarily essential to the present invention.

[0013] Figure 1 is a longitudinal cross-sectional view of a stirring device 1 according to an embodiment of the present invention. In this embodiment, the stirring device 1 is installed in the vertical direction, which is the up-and-down direction or vertical direction in Figure 1, and the up-and-down direction, vertical direction, and vertical direction are used synonymously, as are the left-and-right direction, side-by-side direction, and horizontal direction. The present invention is also applicable to a stirring device 1 that is not installed in the vertical direction, in which case the up-and-down direction, vertical direction and vertical direction are different, and the left-and-right direction, side-by-side direction and horizontal direction are different. Furthermore, as will be described later, the rotation axis 31 of the stirring blade 3 is provided in the up-and-down direction, vertical direction, and vertical direction, so the up-and-down direction, vertical direction, and vertical direction are also called axial directions. In addition, the left-and-right direction, side-by-side direction, and horizontal direction determine the diameter of the stirring tank 2 and the stirring blade 3, so the left-and-right direction, side-by-side direction, and horizontal direction are also called radial directions.

[0014] The agitator 1 comprises an agitator 2 for containing the fluid to be agitated and an agitator blade 3 for agitating the fluid in the agitator 2 by rotation. The agitator 2 comprises a cylindrical straight body 21 located above and extending axially, and a bottom 22 located below and continuous with the straight body 21. The inner circumferential wall or side wall of the straight body 21 has a circular cross-section when viewed from above, and its diameter D is hereinafter also referred to as the tank diameter D of the agitator 2. The cross-section of the straight body 21 and / or the agitator 2 when viewed from above may be any non-circular shape. In this case, the tank diameter D of the agitator 2 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 of these. At least a portion of the upper part of the straight body 21 is open to allow the fluid to be agitated to be introduced, and can be closed with a lid or the like while the fluid is being agitated by the agitator blade 3. The fluid to be stirred may be supplied into the stirring tank 2 from a fluid supply port, such as a supply nozzle, provided on the side of the straight body section 21.

[0015] The bottom 22 of the stirring tank 2 is formed in a curved shape that bulges downward from the lower end of the straight body 21. The center of the bottom 22 is formed by the curved bulge, which gives way to the lowest part of the stirring tank 2. The lowest part of the stirring tank 2 may be provided with an outlet that allows the fluid inside the stirring tank 2 to be discharged to the stirring device 1. This outlet is configured to be openable and closable by an outlet opening / closing mechanism such as a valve. When the fluid to be stirred is introduced into the stirring tank 2 and held there, or when the fluid before discharge is stirred by the stirring blades 3 to equalize the concentration, a valve controlled to a closed state closes the outlet. When the fluid to be discharged after the concentration has been equalized is stirred by the stirring blades 3 and then discharged, a valve controlled to an open state opens the outlet. The fluid after stirring may be discharged from an opening in the upper part of the stirring tank 2, such as when the lid is open. Alternatively, the fluid after stirring may be discharged to the outside of the stirring tank 2 from a fluid outlet such as a discharge nozzle provided on the side of the straight body 21.

[0016] The horizontal boundary line between the cylindrical straight body portion 21 and the curved bottom portion 22 is also called the tangent line TL. Hereinafter, the vertical distance between the tangent line TL and the surface or liquid level LL of the fluid in the stirring tank 2 is also referred to as the reference height. Also, the vertical distance between the lowest part of the stirring tank 2 (bottom portion 22) and the liquid level LL of the fluid in the stirring tank 2 is also called the liquid height.

[0017] The flat stirring blade 3 with the normal direction being the direction perpendicular to the plane of FIG. 1 is rotatably provided around the vertical rotation axis 31 that substantially coincides with the vertical central axis of the stirring tank 2. Above the rotation axis 31, a rotation drive unit such as a motor that generates rotational power and a rotation power conversion unit such as a transmission or a reduction gear that converts the rotational power into a desired rotational speed (or rotational velocity) and torque are provided. Note that a plurality of stirring blades 3 may be provided on the rotation axis 31 as necessary. The stirring blade 3 in FIG. 1 is larger than the small stirring blade 3 in FIG. 3 described later, and is suitable for stirring with a Reynolds number or a stirring Reynolds number of 100 or more.

[0018] The stirring blade 3 is rotationally driven in different modes by a motor and / or a transmission connected to the rotation axis 31 so as to mainly generate significantly different stirring powers Pv [kW / m per unit volume in two main phases. The first phase is the stirring phase in a state where the discharge port (not shown) at the lowest part of the stirring tank 2 (bottom portion 22) is closed, and the stirring blade 3 is rotationally driven at a relatively high speed so as to generate a relatively large Pv. In this stirring phase, the concentration of the fluid in the stirring tank 2 that has been effectively stirred, pulverized, refined, and mixed by the relatively large stirring power is homogenized before the subsequent discharge phase. The second phase is the discharge phase in a state where the discharge port (not shown) at the lowest part of the stirring tank 2 (bottom portion 22) is opened, and the stirring blade 3 is rotationally driven at a relatively low speed so as to generate a relatively small Pv. In this discharge phase, while effectively maintaining the concentration homogenized in the previous stirring phase by the relatively small stirring power, the fluid with a desired concentration is discharged through the discharge port.

[0019] ​According to the stirring device 1 as described above, stirring in the stirring tank 2 and discharging to the outside of the stirring tank 2 can be performed for any fluid (liquid) through two consecutive phases, namely the stirring phase and the discharging phase. However, the stirring device 1 in which the ultrasonic oscillation unit 4 described below is provided together with the stirring blade 3 is preferably applied to, for example, a high-viscosity fluid having a viscosity of 100 cP or more. Examples of such a high-viscosity fluid include any fluid (oil, varnish, rubber, polymer solution, molten resin, etc.) containing fine particles such as carbon black.

[0020] The stirring by the stirring blade 3 is microscopically performed by the vortices generated by the rotating stirring blade 3. The size of the vortices that a general stirring blade 3 can generate is typically from several microns to several tens of microns, and even for a stirring blade 3 with high stirring performance such as a dispersing type, it is about several hundred nanometers. In contrast, for example, the typical diameter of carbon black is about 20 - 50 nm. Therefore, the stirring blade 3 alone cannot refine and / or disperse the aggregates of nanoparticles with a small diameter such as carbon black. On the other hand, the ultrasonic waves oscillated by the ultrasonic oscillation unit 4 generate vortices with a size of several nanometers to several tens of nanometers or less, so that aggregates of fine particles such as carbon black can be easily refined and / or dispersed. Also, since fine particles such as carbon black are extremely likely to aggregate, fine particles such as carbon black are mixed with a high-viscosity fluid having a viscosity of 100 cP or more during stirring so that the fine particles refined and / or dispersed by ultrasonic waves or the like do not re-aggregate. Furthermore, since the total surface area of the fine particles increases due to the refinement and / or dispersion of the fine particle aggregates by ultrasonic waves or the like, the viscosity of the fluid becomes even higher by stirring.

[0021] The ultrasonic emitting unit 4, such as an ultrasonic transducer or ultrasonic oscillator that emits ultrasonic waves, is positioned close to the stirring blade 3 within the stirring tank 2. As mentioned above, since the flat plate-shaped stirring blade 3 rotates around the axial rotation axis 31, the radial distance between the stirring blade 3 and the ultrasonic emitting unit 4 fluctuates. Here, "the ultrasonic emitting unit 4 is positioned close to the stirring blade 3" means that in the state shown in Figure 1, when the rotating stirring blade 3 is closest to the ultrasonic emitting unit 4 in the radial direction, the stirring blade 3 and the ultrasonic emitting unit 4 are in close proximity with a radial gap G between them. In other words, the stirring blade 3 has a shape that allows it to rotate in the vicinity of the ultrasonic emitting unit 4 that emits ultrasonic waves within the stirring tank 2 without coming into contact with it.

[0022] Figure 2 schematically shows a top view cross-section perpendicular to the rotation axis 31 of the stirring blade 3. In this example, the stirring blade 3 rotates counterclockwise around the rotation axis 31. The ultrasonic oscillator 4 is attached to the side wall or inner circumferential wall of the stirring tank 2 (straight body section 21) by a mounting member 41. The ultrasonic oscillator 4, positioned to face or nearly face the stirring blade 3 which rotates counterclockwise, emits ultrasonic waves toward the stirring blade 3 and / or gap G which rotate in its vicinity. In this way, the ultrasonic oscillator 4 effectively applies ultrasonic waves to the fluid being stirred by the stirring blade 3. The ultrasonic waves emitted by the ultrasonic oscillator 4 may be in the counter-rotation direction opposite to the rotation direction of the stirring blade 3 (counterclockwise in the example of Figure 2) (clockwise in the example of Figure 2), or in the radial direction connecting the ultrasonic oscillator 4 and the rotation axis 31 of the stirring blade 3 (left-right direction in the example of Figure 2), or may include components in both the counter-rotation direction and the radial direction. In particular, since the ultrasonic waves emitted radially by the ultrasonic oscillator 4 are directly applied to the gap G with the stirring blade 3, this, combined with the strong shear force applied to the fluid in this small gap G, makes it possible to atomize the fluid extremely effectively.

[0023] The gap G, which is the closest radial distance between the stirring blade 3 and the ultrasonic oscillator 4, should preferably be as small as possible from two main viewpoints: generating a strong shear force between the stirring blade 3 and the ultrasonic oscillator 4, and preventing concentrated or localized application of ultrasound by the adjacent ultrasonic oscillator 4. Specifically, studies on various high-viscosity fluids with a viscosity of 100 cP or more, including carbon black, revealed that if the closest distance (gap G) between the stirring blade 3 and the ultrasonic oscillator 4 is 3% or less of the tank diameter D of the stirring tank 2 (G ≤ 0.03 × D), practically sufficient stirring and / or micronization can be achieved. Generally, the higher the viscosity of the fluid, the more difficult stirring and / or micronization becomes, so the above condition (G ≤ 0.03 × D) is also effective for low-viscosity fluids. Of course, this condition can be relaxed to make the gap G larger (however, 3% or less of the tank diameter D is preferable).

[0024] When the viscosity of the fluid being stirred increases, the flow generated by the impeller tends to attenuate, and if the impeller and the ultrasonic oscillator are separated, as in Patent Document 1, the fluid has difficulty reaching the ultrasonic oscillator. In addition, the ultrasonic waves emitted by the ultrasonic oscillator also tend to attenuate in high-viscosity fluids. In this embodiment, since the ultrasonic oscillator 4 is positioned close to the impeller 3 in the stirring tank 2, the rotation of the impeller 3 can directly guide the high-viscosity fluid to the ultrasonic oscillator 4. In particular, the ultrasonic oscillator 4 directly applies ultrasonic waves to the high-viscosity fluid guided into the gap G where a strong shear force acts, making it extremely effective to atomize the high-viscosity fluid and particles in the fluid.

[0025] As shown in Figure 2, one or more baffles 5 are arranged along the side wall of the stirring tank 2. Also, as shown in Figure 1, each baffle 5 extends axially over approximately the entire reference height between the liquid level LL and the tangent line TL. The baffles 5, also called baffles, are provided to prevent the fluid from rotating along with the impeller 3 due to inertia. When the fluid, which has been rotated circumferentially by the impeller 3, hits the baffles 5, an axial flow is generated, and the fluid is effectively stirred by the rotating impeller 3 without rotating along with it.

[0026] The baffles 5 are typically arranged at approximately equal intervals along the circumferential direction of the stirring tank 2. In the example shown in Figure 2, one of the eight baffles 5, which were arranged at approximately 45-degree intervals along the inner circumferential wall of the stirring tank 2, is replaced by an ultrasonic oscillator 4. In this case, the interval between the ultrasonic oscillator 4 and a circumferentially adjacent baffle 5 (approximately 45 degrees) is approximately equal to the interval between adjacent baffles 5 (45 degrees). Alternatively, the existing eight baffles 5 may be left as they are, and the ultrasonic oscillator 4 may be additionally installed at a circumferential position of the stirring tank 2 where no baffles 5 are present. Furthermore, multiple ultrasonic oscillators 4 may be provided. In this case, similar to the multiple baffles 5, it is preferable that the multiple ultrasonic oscillators 4 be arranged symmetrically along the circumferential direction of the stirring tank 2.

[0027] As shown in Figure 1, the ultrasonic oscillator 4 extends axially over approximately the entire reference height between the liquid level LL and the tangent line TL. In Figure 1, the ultrasonic oscillator 4 is schematically shown as a single long member in the axial direction, but the ultrasonic oscillator 4 may also be constructed by arranging multiple ultrasonic transducers, each emitting ultrasonic waves, in the axial direction. In the example in Figure 1, the ultrasonic oscillator 4 extending axially is in close proximity to the stirring blade 3 on the inner circumference side near the rotation axis 31 of the stirring blade 3. In other words, in the state shown in Figure 1, when the rotating stirring blade 3 is closest to the ultrasonic oscillator 4 in the radial direction, the axial edge on the inner circumference side of the ultrasonic oscillator 4 and the axial edge on the outer circumference side of the stirring blade 3 are approximately parallel to each other and face each other with a radial gap G in between. In this way, a small gap G is formed over almost the entire reference height of the stirring blade 3 in the straight body section 21 of the stirring tank 2 (the axial length excluding the portion below the tangent line TL (however, the stirring blade 3 may extend below the tangent line TL)), where strong shear force and ultrasonic waves from the ultrasonic wave emitting unit 4 are concentrated. As a result, the fluid and particles in the fluid can be stirred and / or atomized very effectively.

[0028] Figure 3 shows a first modified example of the stirring blade 3 and ultrasonic oscillator 4. In the description of the modified example, components similar to those in Figure 1 and / or Figure 2 are denoted by the same reference numerals, and redundant explanations are omitted. The flat stirring blade 3, whose normal direction is perpendicular to the plane of the paper in Figure 3, is rotatably mounted around a vertical rotation axis 31 that substantially coincides with the vertical central axis of the stirring tank 2. This anchor-shaped or U-shaped stirring blade 3 is also called an anchor blade and is suitable for stirring with a Reynolds number or stirring Reynolds number of less than 100. Other stirring blades 3 suitable for stirring with a similar Reynolds number include ribbon blades or helical ribbon blades.

[0029] The ultrasonic emitting unit 4, such as an ultrasonic transducer or ultrasonic oscillator that emits ultrasonic waves, is positioned close to the stirring blade 3 in the stirring tank 2. Here, "the ultrasonic emitting unit 4 is positioned close to the stirring blade 3" means that in the state shown in Figure 3, when the rotating stirring blade 3 is closest to the ultrasonic emitting unit 4 in the radial direction, the stirring blade 3 and the ultrasonic emitting unit 4 are in close proximity with a radial gap G between them. In other words, the stirring blade 3 has a shape that allows it to rotate in the vicinity of the ultrasonic emitting unit 4 that emits ultrasonic waves in the stirring tank 2 without coming into contact with it. As with the other examples mentioned above, it is preferable to make the gap G, which is the closest radial distance between the stirring blade 3 and the ultrasonic emitting unit 4, as small as possible from two main viewpoints: the generation of strong shear force between the stirring blade 3 and the ultrasonic emitting unit 4, and the concentrated or localized application of ultrasonic waves by the adjacent ultrasonic emitting unit 4. Specifically, for high-viscosity fluids containing carbon black or the like with a viscosity of 100 cP or more, it is preferable to set the closest approach distance (gap G) between the stirring blade 3 and the ultrasonic oscillator 4 to 3% or less of the tank diameter D of the stirring tank 2 (G ≤ 0.03 × D).

[0030] The ultrasonic oscillator 4 extends axially over approximately the entire reference height between the liquid surface LL and the tangent line TL. In the example shown in Figure 3, the ultrasonic oscillator 4, which extends axially, is in close proximity to the stirring blade 3 on its outer circumference, farther from the rotation axis 31 of the stirring blade 3. In other words, in the state shown in Figure 3, when the rotating stirring blade 3 is closest to the ultrasonic oscillator 4 in the radial direction, the axial edge on the outer circumference of the ultrasonic oscillator 4 and the axial edge on the inner circumference of the stirring blade 3 are approximately parallel to each other and face each other with a radial gap G. In this way, a small gap G is formed over approximately the entire reference height of the stirring blade 3 in the straight body section 21 of the stirring tank 2 (the axial length excluding the portion below the tangent line TL), to which strong shear force and ultrasonic waves from the ultrasonic oscillator 4 are concentrated, thus enabling extremely effective stirring and / or micronization of the fluid and particles in the fluid.

[0031] Figure 4 shows a second modified example of the stirring blades 3 and ultrasonic oscillator 4. The multiple (four) flat stirring blades 3 in the upper, lower, left, and right directions, whose normal direction is perpendicular to the plane of the paper in Figure 4, are integrally rotatable around a vertical rotation axis 31 that substantially coincides with the vertical central axis of the stirring tank 2. In the axial gap between the upper and lower stirring blades 3 on the left side of Figure 4, the mounting member 41 of the ultrasonic oscillator 4 extends radially inward or penetrates through the axial gap. The ultrasonic oscillator 4, attached to the inner end of the mounting member 41, extends upward and downward along the axial direction and is positioned close to the upper and lower stirring blades 3. As shown in Patent Document 2, the normal direction of one or more stirring blades 3 may be inclined with respect to the direction perpendicular to the plane of the paper in Figure 4. Furthermore, one or more stirring blades 3 are not limited to a planar shape, but may also be curved, such as a helical shape (spiral shape) as shown in Patent Document 2.

[0032] Here, "the ultrasonic oscillator 4 is positioned close to the stirring blade 3" means that in the state shown in Figure 4, where the rotating stirring blade 3 is closest to the ultrasonic oscillator 4 in the radial direction, the stirring blade 3 and the ultrasonic oscillator 4 are in close proximity with a radial gap G. In other words, the stirring blade 3 has a shape that allows it to rotate in the vicinity of the ultrasonic oscillator 4, which emits ultrasonic waves in the stirring tank 2, without coming into contact with it. As with the other examples mentioned above, it is preferable to make the gap G, which is the closest radial distance between the stirring blade 3 and the ultrasonic oscillator 4, as small as possible from two main viewpoints: the generation of strong shear force between the stirring blade 3 and the ultrasonic oscillator 4, and the concentrated or localized application of ultrasonic waves by the adjacent ultrasonic oscillator 4. Specifically, for high-viscosity fluids containing carbon black or the like with a viscosity of 100 cP or more, it is preferable to make the closest distance (gap G) between the stirring blade 3 and the ultrasonic oscillator 4 3% or less of the tank diameter D of the stirring tank 2 (G ≤ 0.03 × D).

[0033] In the example shown in Figure 4, the ultrasonic oscillator 4, which extends vertically along the axial direction, is in close proximity to the two upper and lower stirring blades 3 on the outer circumference side, farther from the rotation axis 31 of the stirring blades 3. In other words, in the state shown in Figure 4, when the rotating stirring blades 3 are closest to the ultrasonic oscillator 4 in the radial direction, the axial edge on the outer circumference side of the ultrasonic oscillator 4 and the axial edges on the inner circumference side of the two upper and lower stirring blades 3 are approximately parallel to each other and face each other with a radial gap G in between. In this way, a small gap G is formed around the two upper and lower stirring blades 3, to which a strong shear force and ultrasonic waves from the ultrasonic oscillator 4 are concentrated, making it possible to stir and / or refine the fluid and particles in the fluid very effectively. In particular, because fluid flow occurs between the axial gap between the two upper and lower stirring blades 3 (the space through which the mounting member 41 passes) and between the upper and lower gaps G, the substantial amount of fluid and particles in the fluid that are dispersed and / or refined in each upper and lower gap G can be increased.

[0034] Figure 5 shows a third modified example of the stirring blade 3 and the ultrasonic oscillator 4. The stirring blade 3 in Figure 5 is the stirring blade 3 in Figure 1 with an additional pair of outer peripheral blades 32 that wrap around to the outer circumference of the ultrasonic oscillator 4. The outer peripheral blades 32 extend from the lower part of the main body of the stirring blade 3 outward at the bottom 22 of the stirring tank 2 and pass below the ultrasonic oscillator 4. Subsequently, the outer peripheral blades 32 extend upward along the side wall of the straight section 21 of the stirring tank 2 and are positioned close to the ultrasonic oscillator 4 from the outer circumference. As a result, the ultrasonic oscillator 4 is sandwiched from both radial sides by the outer peripheral blades 32 on the outer circumference and the main body of the stirring blade 3 on the inner circumference.

[0035] In the state shown in Figure 5, where the rotating impeller 3 (including the outer blade 32) is closest to the ultrasonic oscillator 4 in the radial direction, a small gap G is formed between the ultrasonic oscillator 4 and the impeller 3 on both radial sides of the ultrasonic oscillator 4. As with the other examples described above, it is preferable to make the gap G, which is the closest radial distance between the impeller 3 and the ultrasonic oscillator 4, as small as possible from two main viewpoints: generating a strong shear force between the impeller 3 and the ultrasonic oscillator 4, and concentrating or localizing the application of ultrasound by adjacent ultrasonic oscillator 4. Specifically, for high-viscosity fluids containing carbon black or the like with a viscosity of 100 cP or more, it is preferable to make the closest distance (gap G) between the impeller 3 and the ultrasonic oscillator 4 3% or less of the diameter D of the stirring tank 2 (G ≤ 0.03 × D).

[0036] In the example shown in Figure 5, the ultrasonic oscillator 4, which extends along the axial direction, is close to the body of the stirring blade 3 on the inner circumference side near the rotation axis 31 of the stirring blade 3, and close to the outer blade 32 of the stirring blade 3 on the outer circumference side farther from the rotation axis 31. In other words, in the state shown in Figure 5, when the rotating stirring blade 3 is closest to the ultrasonic oscillator 4 in the radial direction, the axial edge on the inner circumference side of the ultrasonic oscillator 4 and the axial edge on the outer circumference side of the body of the stirring blade 3 are substantially parallel to each other and face each other with a radial gap G, and the axial edge on the outer circumference side of the ultrasonic oscillator 4 and the axial edge on the inner circumference side of the outer blade 32 of the stirring blade 3 are substantially parallel to each other and face each other with a radial gap G. In this way, a small gap G is formed on both radial sides of the ultrasonic oscillator 4, to which a strong shear force and ultrasonic waves from the ultrasonic oscillator 4 are concentrated, so that the fluid and particles in the fluid can be stirred and / or atomized very effectively.

[0037] Figure 6 shows a fourth modified example of the stirring blade 3 and the ultrasonic oscillator 4. The stirring blade 3 in Figure 6 is the stirring blade 3 in Figure 4 with an additional pair of inner circumferential blades 33 that extend axially on the inner circumference side of the ultrasonic oscillator 4. The inner circumferential blades 33 are positioned close to the ultrasonic oscillator 4 from the inner circumference side. As a result, the ultrasonic oscillator 4 is sandwiched from both radial sides by the main body of the stirring blade 3 on the outer circumference side and the inner circumferential blades 33 on the inner circumference side.

[0038] In the state shown in Figure 6, where the rotating impeller 3 (including the inner impeller 33) is closest to the ultrasonic oscillator 4 in the radial direction, a small gap G is formed between the ultrasonic oscillator 4 and the impeller 3 on both radial sides of the ultrasonic oscillator 4. As with the other examples described above, it is preferable to make the gap G, which is the closest radial distance between the impeller 3 and the ultrasonic oscillator 4, as small as possible from two main viewpoints: generating a strong shear force between the impeller 3 and the ultrasonic oscillator 4, and concentrating or localizing the application of ultrasound by adjacent ultrasonic oscillator 4. Specifically, for high-viscosity fluids containing carbon black or the like with a viscosity of 100 cP or more, it is preferable to make the closest distance (gap G) between the impeller 3 and the ultrasonic oscillator 4 3% or less of the diameter D of the stirring tank 2 (G ≤ 0.03 × D).

[0039] In the example shown in Figure 6, the ultrasonic oscillator 4, which extends along the axial direction, is close to the inner blade 33 of the stirring blade 3 on the inner circumference side near the rotation axis 31 of the stirring blade 3, and close to the main body of the stirring blade 3 on the outer circumference side farther from the rotation axis 31. In other words, in the state shown in Figure 6, when the rotating stirring blade 3 is closest to the ultrasonic oscillator 4 in the radial direction, the axial edge on the inner circumference side of the ultrasonic oscillator 4 and the axial edge on the outer circumference side of the inner blade 33 of the stirring blade 3 are substantially parallel to each other and face each other with a radial gap G, and the axial edge on the outer circumference side of the ultrasonic oscillator 4 and the axial edge on the inner circumference side of the main body of the stirring blade 3 are substantially parallel to each other and face each other with a radial gap G. In this way, a small gap G is formed on both radial sides of the ultrasonic oscillator 4, to which a strong shear force and ultrasonic waves from the ultrasonic oscillator 4 are concentrated, so that the fluid and particles in the fluid can be stirred and / or atomized very effectively.

[0040] The present invention has been described above based on embodiments. Various modifications are possible for each component and each combination of 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] The configuration, operation, and function of each device and method described in the embodiments can be realized by hardware resources or software resources, or by the cooperation of hardware resources and software resources. Hardware resources include, for example, processors, ROMs, RAMs, and various integrated circuits. Software resources include, for example, operating systems and application programs. [Explanation of Symbols]

[0042] 1. Agitator, 2. Agitator tank, 3. Agitator blade, 4. Ultrasonic oscillator, 5. Baffle, 21. Straight body, 22. Bottom, 31. Rotating shaft, 32. Outer blade, 33. Inner blade, 41. Mounting member.

Claims

1. A stirring tank for containing the fluid, A stirring blade that stirs the fluid in the stirring tank by rotation, An ultrasonic oscillator unit, positioned in close proximity to the stirring blade within the stirring tank, emits ultrasonic waves, Equipped with, The edges of the ultrasonic oscillator and the edge of the stirring blade, both extending along an axial direction parallel to the rotation axis of the stirring blade, face each other through a radial gap in the stirring tank that is perpendicular to the axial direction. A stirring device in which, in a cross section perpendicular to the rotation axis where the ultrasonic oscillating unit and the stirring blade face each other through the gap, the closest radial distance between the stirring blade and the ultrasonic oscillating unit is 3% or less of the diameter of the stirring tank.

2. The stirring blade comprises an axially extending portion that extends along the axial direction, The ultrasonic oscillation unit includes an axially extending portion that extends along the axial direction, The axially extended portion of the ultrasonic oscillator and the axially extended portion of the stirring blade face each other with the gap between them. The aforementioned closest approach distance is achieved over an axial range in which the axially extended portion of the ultrasonic oscillator and the axially extended portion of the stirring blade face each other. The stirring device according to claim 1.

3. The stirring device according to claim 1 or 2, wherein the gap is formed over the entire height of the stirring blade in the straight section of the stirring tank.

4. The stirring device according to claim 1 or 2, wherein the viscosity of the fluid is 100 cP or more.

5. The stirring apparatus according to claim 1 or 2, wherein the fluid contains carbon black.

6. The stirring device according to claim 1 or 2, wherein the ultrasonic oscillating unit is attached to the side wall of the stirring tank.

7. The stirring blade comprises an inner circumferential blade that rotates on the inner side of the ultrasonic oscillator in the stirring tank, The stirring device according to claim 1 or 2, wherein the inner edge of the ultrasonic oscillating unit faces the outer edge of the inner blade.

8. The stirring blade comprises an outer peripheral blade that rotates on the outer peripheral side of the ultrasonic oscillator in the stirring tank, The stirring device according to claim 1 or 2, wherein the outer peripheral edge of the ultrasonic oscillating unit faces the inner peripheral edge of the outer peripheral blade.

9. The stirring blade comprises an inner blade that rotates on the inner side of the ultrasonic oscillating unit in the stirring tank, and an outer blade that rotates on the outer side of the ultrasonic oscillating unit in the stirring tank, The inner edge of the ultrasonic oscillator faces the outer edge of the inner circumferential blade. The outer edge of the ultrasonic oscillator faces the inner edge of the outer wing. The stirring device according to claim 1 or 2.

10. The stirring device according to claim 1 or 2, wherein the ultrasonic oscillating unit emits ultrasonic waves in a direction opposite to the rotation direction of the stirring blade.

11. The stirring apparatus according to claim 1 or 2, wherein the ultrasonic oscillating unit emits ultrasonic waves in the radial direction connecting the ultrasonic oscillating unit and the rotation axis of the stirring blade.

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