STIRRING DEVICE AND STIRRING METHOD

Abstract

A stirring device 10 includes a stirring tank 12 that accommodates a fluid, a fluid blade 14 that is rotated to cause the fluid to flow in the stirring tank 12, and a shearing blade 16 that is provided between a bottom portion 22 of the stirring tank 12 and the fluid blade 14, is rotated to stir the fluid, and includes a blade portion 17 that extends from a shearing blade rotating shaft 46 to a side wall 12a of the stirring tank 12. At least a portion (lower end portion) of the fluid blade 14 is rotated between a tip portion of the blade portion 17 and the side wall 12a of the stirring tank 12. A normal direction of a stirring surface of the blade portion 17 is inclined with respect to both an axial direction of the shearing blade rotating shaft 46 and a rotation direction of the blade portion 17. The bottom portion 22 of the stirring tank 12 has a planar shape.

Description

Technical field

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

[0002] As a stirring device that stirs a fluid in a stirring tank, a stirring device including a fluid blade and a disc-shaped shearing blade (dispersing blade) is disclosed in PTL 1. The dispersing blade provided at a center position, which is in contact with a flow formed by the rotation of the fluid blade, effectively shears the fluid. Citation listPatent literature

[0003] [PTL 1] International Publication No. 2017 / 002905 Summary of the inventionTechnical problem

[0004] The dispersing blade disclosed in PTL 1 has a disc shape. Therefore, as a blade diameter is increased, load power increases, and it is difficult to maintain rotational balance. Therefore, the blade diameter of the dispersing blade disclosed in PTL 1 needs to be reduced. Specifically, as described in paragraph 0031 of PTL 1, the blade diameter of the dispersing blade is set between 10% and 30% of a tank diameter of the stirring tank. In this case, for example, when the viscosity of the fluid to be stirred by the stirring device increases, the blade diameter of the dispersing blade needs to be further reduced due to a performance issue, and there are concerns that the fluid is less likely to reach the dispersing blade with a small diameter.

[0005] The present invention has been made in view of these circumstances, and an object of the present invention is to provide a stirring device and the like which can effectively stir even a fluid having high viscosity or a fluid having high thixotropy. Solution to problem

[0006] In order to solve the above problems, according to one aspect of the present invention, there is provided a stirring device comprising: a stirring tank that accommodates a fluid; a fluid blade that is rotated to flow the fluid in the stirring tank; and a stirring blade that is provided between a bottom portion of the stirring tank and the fluid blade, is rotated to stir the fluid, and includes a blade portion that extends from a rotating shaft of the stirring blade to a side wall of the stirring tank.

[0007] In this aspect, the non-disk-shaped stirring blade including the blade portion extending from the rotary shaft to the side wall of the stirring tank is used. Therefore, unlike the disc-shaped dispersing blade disclosed in PTL 1, it is not necessary to reduce a blade diameter. As described above, the current generated by the fluid blade can easily reach the stirring blade, whose diameter can be increased compared to the prior art. Therefore, even a fluid with high viscosity is effectively stirred.

[0008] Another aspect of the present invention is a stirring method. The stirring method includes rotating a fluid blade to flow a fluid in a stirring vessel; and rotating a stirring blade, which is provided between a bottom portion of the stirring vessel and the fluid blade and includes a blade portion extending from a rotating shaft of the stirring blade to a side wall of the stirring vessel, at a higher speed than the fluid blade to stir the fluid.

[0009] Any combination of the components and configurations described above obtained by converting these expressions into methods, apparatuses, systems, recording media, computer programs, and the like is also included in the present invention. Advantageous effects of the invention

[0010] According to the present invention, even a fluid with high viscosity or a fluid with high thixotropy can be effectively stirred. Brief description of the drawings Fig. 1 is a vertical cross-sectional view showing a stirring device. Fig. 2 is a perspective view showing a shear blade as viewed from a substantially lateral surface. Fig. 3 is a top view or a bottom view showing the shear blade. Fig. 4 is a perspective view showing a shear blade rotating shaft. Description of embodiments

[0011] 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 the drawings, the same or equivalent components, elements, processes, and the like are denoted by the same reference numerals, and duplicate descriptions thereof will be omitted. The scales and shapes of each portion shown in the drawings are set for convenience in description and are not interpreted restrictively unless otherwise specified. The embodiment is illustrative and does not limit the scope of the present invention in any way. All features described in the embodiment and combinations thereof are not necessarily essential to the present invention.

[0012] Fig. Fig. 1 is a vertical cross-sectional view showing a stirring device 10 according to the embodiment of the present invention. In the present embodiment, it is assumed that the stirring device 10 is installed in a vertical direction, which is an up-down direction or a longitudinal direction in Fig. 1. The up-down direction, the longitudinal direction, and the vertical direction are used synonymously, and a left-right direction, a transverse direction, and a horizontal direction are used synonymously. Furthermore, the present invention is also applicable to a stirring device 10 that is not installed in the vertical direction. In this case, the vertical direction is different from the up-down direction and the longitudinal direction, and the horizontal direction is different from the left-right direction and the transverse direction. Further, each of rotating shafts of respective blades, such as a fluid blade rotating shaft 34 of a fluid blade 14, a shearing blade rotating shaft 46 of a shearing blade 16, and a gate blade rotating shaft 52 of a gate blade 18, is provided in the up-down direction, the longitudinal direction, and the vertical direction, which will be described below.Therefore, the up-down direction, the longitudinal direction, and the vertical direction are also referred to as an axial direction. Furthermore, the left-right direction, the transverse direction, and the horizontal direction are also referred to as a radial direction because they determine the diameters of a stirring vessel 12, the fluid blade 14, the shear blade 16, the gate blade 18, and the like.

[0013] The stirring device 10 includes the stirring tank 12 that accommodates a fluid to be stirred, and the fluid blade 14, the shearing blade 16, and the gate blade 18 as rotating blades that are rotatable about the rotating shafts 34, 46, and 52 in the axial direction in the stirring tank 12. The stirring tank 12 includes a cylindrical or tubular barrel portion 20 provided on a top surface and extending in the axial direction, a bottom portion 22 provided on a bottom surface so as to be continuous with the barrel portion 20, and a top portion 24 provided on the top surface so as to be continuous with the barrel portion 20. The bottom portion 22 of the stirring tank 12 in the present embodiment has a planar shape with the axial direction as a normal direction.When the bottom portion 22 is formed in a flat shape, there is an advantage in that the distance to the shearing blade 16 in the axial direction can be reduced, which will be described below. However, the present invention is applicable to the stirring tank 12 having the bottom portion 22 of any shape, such as a curved surface shape or an inverted conical shape as in PTL 1.

[0014] The flat bottom portion 22 of the agitation tank 12 is attachable to a flange portion 21 formed on a cylindrical side wall 12a of the agitation tank 12, or to the bottom portion or lowermost portion of the barrel portion 20 so as to protrude in the radial direction. That is, when the agitation tank 12 is assembled, the plate-shaped bottom portion 22 can be brought into contact with the flange portion 21 of the barrel portion 20 from the bottom side and can be fixed by a fastening tool such as a screw. In this case, the shearing blade 16, the shearing blade rotating shaft 46, a shearing blade driving unit 47, and the like described below can be attached to the bottom portion 22 in advance.Alternatively, the shearing blade 16, the shearing blade rotating shaft 46, the shearing blade driving unit 47, and the like may be attached to the bottom portion 22 after the bottom portion 22 is attached to the flange portion 21. When the bottom portion 22 of the agitation tank 12 is formed in the planar shape as described above, it is possible to improve the assemblability of the agitation tank 12 and the agitating device 10.

[0015] Similar to the bottom portion 22, the upper portion 24 of the agitation tank 12 in the present embodiment has a planar shape with the axial direction as the normal direction. The planar upper portion 24 of the agitation tank 12 is attachable to a flange portion 23 formed on the cylindrical side wall 12a of the agitation tank 12 or to the upper portion or uppermost portion of the barrel portion 20 so as to protrude in the radial direction. That is, when the agitation tank 12 is assembled, the plate-shaped upper portion 24 can be brought into contact with the flange portion 23 of the barrel portion 20 from the top and can be fastened by the fastening tool such as the screw. In this case, the fluid blade 14, the fluid blade rotating shaft 34, and a fluid blade driving unit (not shown) provided on the top in Fig. 1 is provided, the door leaf 18, the door leaf rotating shaft 52, a door leaf drive unit (not shown) which is mounted on the top in Fig. 1, and the like described below may be attached to the upper portion 24 in advance. Alternatively, the fluid blade 14, the fluid blade rotating shaft 34, the fluid blade driving unit, the door blade 18, the door blade rotating shaft 52, the door blade driving unit, and the like may be attached to the upper portion 24 after the upper portion 24 is attached to the flange portion 23.

[0016] An inner peripheral wall or the side wall 12a of the barrel portion 20 of the agitated tank 12 has a circular cross section in a plan view, and a diameter D thereof is hereinafter also referred to as a tank diameter D. Furthermore, the cross section of the barrel portion 20 and / or the agitated tank 12 in a plan view may have any non-circular shape. In this case, the tank diameter D of the agitated tank 12 may be an inscribed circle diameter of the cross-sectional shape, a circumscribed circle diameter of the cross-sectional shape, or an average or intermediate value of the diameters. At least a part of an upper portion of the barrel portion 20 is open so that the fluid to be agitated can be injected, and may be closed by a lid or the like during agitation of the fluid by the agitator 10.Furthermore, the fluid to be stirred may be supplied into the stirring tank 12 through a fluid supply port such as a supply nozzle provided on a side surface of the barrel portion 20.

[0017] The fluid blade 14, the shearing blade 16 and the gate blade 18 are individually driven to move in the vertical direction (the up-down direction in Fig. 1) are rotated about the rotating shafts. Furthermore, the fluid blade rotating shaft 34 of the fluid blade 14, the shear blade rotating shaft 46 of the shear blade 16 and the gate blade rotating shaft 52 of the gate blade 18 must be rotated in contrast to the Fig. 1, the fluid blades 14, 16, and 18 may not be provided on the same straight line, and their directions may be different from each other. The rotational directions and speeds of the fluid blade 14, the shear blade 16, and the gate blade 18 can be adjusted or controlled independently of each other, and are optimally adjusted or controlled taking into account various conditions, such as the capacity or shape of the agitated tank 12, the properties of the fluid in the agitated tank 12, and the speed or phase of a chemical reaction to be performed in the agitated tank 12.

[0018] Typically, the rotational speed of the shear blade 16, which is responsible for shearing or refining the fluid, fine particles in the fluid, agglomerates of the fluid, and the like, is higher than the rotational speed of the fluid blade 14 and / or the gate blade 18, which is responsible for the flow of the fluid. For example, while the typical rotational speed of the fluid blade 14 is 20 to 30 [rpm] in a case where the capacity of the agitated tank 12 is about 10 [rpm], it is preferable that the rotational speed of the shear blade 16 be about 1,200 [rpm]. Furthermore, while the typical rotation speed of the fluid blade 14 is 20 to 30 [rpm] in a case where the capacity of the stirring tank 12 is about 1,000 [rpm], it is preferable that the rotation speed of the shear blade 16 be about 600 to 900 [rpm]. As described above, it is preferable that the rotation speed of the shear blade 16 be at least 20 times the rotation speed of the fluid blade 14.Furthermore, a rotation speed of about 3,600 [rpm] is required to obtain the shearing performance equivalent to that of the large-diameter shearing blade 16 in the present embodiment with the small-diameter dispersing blade disclosed in PTL 1. According to the shearing blade 16 whose diameter can be increased as described below, the rotation speed is reduced to obtain the desired shearing performance or refining performance. Therefore, the low-power shearing blade drive unit 47 is used, which makes it possible to reduce the size or cost of the stirring device 10.

[0019] The fluid blade rotating shaft 34 of the fluid blade 14 is formed in a cylindrical shape or a tubular shape, and the gate blade rotating shaft 52 of the gate blade 18 is inserted into the fluid blade rotating shaft 34. The fluid blade rotating shaft 34 of the fluid blade 14 and the gate blade rotating shaft 52 of the gate blade 18 extend from the upper portion 24 of the agitation tank 12 to the interior of the agitation tank 12. The fluid blade rotating shaft 34 is driven to rotate by the fluid blade driving unit (not shown) mounted on the upper side in Fig. 1, and the door leaf rotating shaft 52 is driven to be rotated in the fluid leaf rotating shaft 34 by the door leaf driving unit (not shown) mounted on the top side in Fig. 1 is provided. It is preferable that the fluid blade drive unit and the door leaf drive unit are configured by different motors. However, it is preferable that the fluid blade drive unit and the door leaf drive unit are integrally configured as a drive unit including a plurality of motors.

[0020] The shearing blade rotating shaft 46 of the shearing blade 16 serving as the stirring blade extends from the bottom portion 22 of the stirring vessel 12 to the interior of the stirring vessel 12. The shearing blade rotating shaft 46 is driven by the shearing blade driving unit 47 mounted on the bottom in Fig. 1 is driven to rotate. A drive unit constituting the shear blade drive unit 47 and provided below the agitation tank 12 is different from a drive unit constituting the fluid blade drive unit and / or the gate blade drive unit and provided above the agitation tank 12.

[0021] The fluid blade 14 is rotated around the fluid blade rotating shaft 34 by the fluid blade drive unit to cause the fluid to flow in the agitation tank 12. The fluid blade 14 in the illustrated example is a pair of helical impeller blades formed in a spiral shape around the fluid blade rotating shaft 34 in the vertical direction. Furthermore, the shape of the fluid blade 14 is not limited to the spiral shape or the helical impeller blade shape, and it is preferable that the fluid blade 14 has a shape in which a portion near the bottom portion 22 is small in order to ensure sufficient space for installing the shear blade 16 (described below) in a region facing the bottom portion 22 of the agitation tank 12. Therefore, the helical impeller blade in the illustrated example is preferable to an anchor blade having a shape along the bottom portion 22.

[0022] Moreover, in the illustrated example, the helical impeller blade faces the bottom portion 22 at a location near the side wall 12a of the agitation tank 12. However, since the shearing blade 16 is installed in a central region of the agitation tank 12 in the radial direction (a region around a rotating shaft such as the shearing blade rotating shaft 46), the fluid blade 14 (helical impeller blade) and the shearing blade 16 (stirring blade) do not interfere with each other, which will be described below. In many cases, the fluid to be stirred settles, and a discharge port through which the stirred fluid is discharged is provided in the bottom portion 22 of the agitation tank 12. An excellent balance between the flow of the fluid by the fluid blade 14 and the shearing (stirring) by the shearing blade 16 is required.As in the example shown, the configuration in which the fluid blade 14 is rotated in an outer peripheral region of the bottom portion 22 and the shearing blade 16 is rotated in the central region of the bottom portion 22 is used, which makes it possible to improve the quality of the stirred fluid in the bottom portion 22. Moreover, since the fluid blade 14 is present only in the outer peripheral region of the bottom portion 22, it is possible to increase the diameter of the shearing blade 16 in the central region of the bottom portion 22.

[0023] When the fluid blade 14 is rotated integrally with the fluid blade rotating shaft 34 by the fluid blade drive unit, an induced current is formed in a downward direction along the side wall 12a of the barrel portion 20. The fluid carried by the induced current in the agitated tank 12 moves to the bottom portion 22, is guided from the outer peripheral region to the central region where the shearing blade 16 is present, and is efficiently sheared or agitated.

[0024] The fluid sheet 14 contains several (in the case of Fig. 1 shown example two) strip-shaped fluid sheet bodies 26 with a predetermined width and several (in the case of the Fig. 1) support rods 28 which are engaged with inner peripheral portions of upper and lower end portions of the respective fluid blade bodies 26. The plurality of fluid blade bodies 26 and the plurality of support rods 28 are in a state in which they are arranged as shown in Fig. 1 are combined, integrated with each other by welding or the like. Each support rod 28 is a rod-shaped member extending in the axial direction, and the upper and lower end portions of each fluid blade body 26 are engaged with the support rod 28 so as to be supported.

[0025] In the Fig. 1, in which two support rods 28 and two fluid blade bodies 26 are provided, an upper end portion of an upper blade 36 of a first fluid blade body 26 is engaged with an upper end portion of a first support rod 28, and a lower end portion of a lower blade 38 of a second fluid blade body 26 is engaged with a lower end portion of the first support rod 28. Similarly, an upper end portion of the upper blade 36 of the second fluid blade body 26 is engaged with an upper portion of a second support rod 28, and a lower end portion of the lower blade 38 of the first fluid blade body 26 is engaged with a lower portion of the second support rod 28. As described above, the fluid blade bodies 26 engaged with the upper portions and lower portions of the respective support rods 28 are different from each other.In other words, a plurality of different fluid blade bodies 26 are engaged with the respective support rods 28, and the respective fluid blade bodies 26 are engaged with a plurality of different support rods 28.

[0026] In addition, at an intermediate position between the Fig. 1, further (for example two) support rods 28 may be provided on the same circumference in a plan view. The two support rods 28 which are shown in Fig. 1, support or guide a central portion of each fluid sheet body 26 in the axial direction represented by O to maintain each fluid sheet body 26 in a desired spiral shape. The upper end of each support rod 28 is connected to the fluid sheet rotating shaft 34 in the vertical direction. When the fluid sheet rotating shaft 34 is driven to rotate by the fluid sheet driving unit (not shown), the fluid sheet 14, including the support rods 28 and the fluid sheet bodies 26 connected to each other, is integrally rotated to form the downward induced current.

[0027] The two fluid blade bodies 26, formed as a whole in a spiral strip shape, are formed to be point-symmetrical in a plan view with respect to the fluid blade rotating shaft 34. Each of the fluid blade bodies 26 is formed to rotate 180 degrees around the fluid blade rotating shaft 34 in a plan view. Therefore, as described above, the upper end portion of each of the fluid blade bodies 26 is engaged with one support rod 28, and the lower end portion of the fluid blade body 26 is engaged with the other support rod 28 at a position (a 180-degree rotated position) that is point-symmetrical to the one support rod 28 with respect to the fluid blade rotating shaft 34 in a plan view.

[0028] The gate blade 18, which serves as an auxiliary blade or an inner blade having a smaller diameter than the fluid blade 14, is installed on a central side or inner side of the fluid blade 14 in the radial direction. The gate blade 18 is driven by the gate blade drive unit to rotate around the gate blade rotating shaft 52 to flow the fluid in the agitated tank 12 in an aspect different from that of the fluid blade 14 inside the fluid blade 14. Moreover, the shearing blade 16 (described below) is installed below the gate blade 18. Therefore, the distance between the bottom portion 22 of the agitated tank 12 and the gate blade 18 (a lower member 48D described below) in the axial direction is larger than an installation space or an installation height of the shearing blade 16. In other words, a space below the gate blade 18 can be fully utilized by the shearing blade 16.

[0029] The door leaf 18 includes a door leaf body 48 having a rectangular frame shape and being line-symmetrical with respect to the rotating shaft (door leaf rotating shaft 52) ​​in the vertical direction, and the door leaf rotating shaft 52 in the axial direction, which is connected to an upper portion of the door leaf body 48 and driven to rotate by the door leaf drive unit (not shown). The door leaf body 48 has a frame structure in which an upper member 48U in the radial direction, a left member 48L in the axial direction, a right member 48R in the axial direction, and a lower member 48D in the radial direction, each of which is formed in a bar shape or a column shape, are integrated into a rectangular shape. The door leaf 18 is rotated in any direction and at any speed.Typically, however, the door leaf 18 is rotated in a direction opposite to the fluid blade 14 or is rotated at a different speed or a different number of rotations than the fluid blade 14 in the same direction as the fluid blade 14.

[0030] Since the fluid blade 14 and the gate blade 18 rotate in different directions and / or at different rotational speeds, there is a difference between a moving speed of the object to be stirred associated with the rotation of the fluid blade 14 and a moving speed of the object to be stirred associated with the rotation of the gate blade 18. Therefore, it is possible to suppress "co-rotation" in which the object to be stirred in the stirring tank 12 is rotated together with the fluid blade 14, and the object to be stirred flows efficiently in the stirring tank 12. Furthermore, the rotation direction and / or rotational speed of the gate blade 18 is appropriately adjusted, making it possible to generate a flow that causes the object to be stirred, which has been sheared by the shearing blade 16 below the gate blade 18, to flow upward.The induced current thus generated by the gate blade 18 to be directed upward in the central portion of the stirring tank 12 is changed by the fluid blade 14 into an induced current directed downward along the side wall 12a of the stirring tank 12 and is again directed toward the shearing blade 16. Since the current circulating between the fluid blade 14, the shearing blade 16, and the gate blade 18 is formed in this way, it is possible to efficiently stir the object to be stirred.

[0031] The shearing blade 16 as the stirring blade, provided between the bottom portion 22 of the stirring tank 12 and the fluid blade 14, is rotated by the shearing blade drive unit 47 around the shearing blade rotating shaft 46 to shear or stir the fluid in the stirring tank 12. The shearing blade 16 includes a pair of blade portions 17A and 17B (hereinafter collectively referred to as a blade portion 17) extending in the radial direction from the shearing blade rotating shaft 46 to the side wall 12a of the stirring tank 12.

[0032] The blade portion 17 is arranged in a central region closer to the central side or the inner side than the lower end portion of the fluid blade 14 rotated in the radial direction (left-right direction) in the outer peripheral region of the stirring vessel 12 or the bottom portion 22. Therefore, at least a portion (lower end portion) of the fluid blade 14 is sandwiched between a tip portion (a left end portion and a right end portion in Fig. 1) of the blade portion 17 and the side wall 12a of the agitation tank 12 without interfering with the blade portion 17. Moreover, the blade portion 17 is disposed between the upper gate leaf 18 and the bottom portion 22 of the lower agitation tank 12 in the axial direction (up-down direction). That is, the blade portion 17 is disposed in the central region facing the bottom portion 22 of the agitation tank 12. As described above, since the bottom portion 22 of the agitation tank 12 has a planar shape in the present embodiment, the shearing blade 16 including the blade portion 17 extending in the radial direction substantially parallel to the bottom portion 22 can be efficiently or compactly arranged in a substantially rectangular parallelepiped region surrounded by the upper gate blade 18, the fluid blade 14 (lower end portion) in the left-right direction, and the bottom portion 22 of the lower agitation tank 12.

[0033] Fig. Figure 2 is a perspective view showing the shear blade 16 as viewed from a substantially side surface, and Fig. 3 is a top view or a bottom view showing the shearing blade 16. The shearing blade 16 includes a cylindrical projection 161 in which the axial direction (up-down direction in Fig. 2) is a height direction, and the pair of blade portions 17A and 17B (blade portion 17) extending from the projection 161 in the radial direction (left-right direction in Fig. 2 and Fig. 3). A mounting hole 46A in the axial direction, into which the rotary shaft is inserted and mounted, is provided in a central portion of the projection 161 in the radial direction. As shown in Fig. 3, the mounting hole 46A is provided in a center of a recessed portion 46B having a substantially rectangular or square cross section. In a case where the recessed portion 46B is provided on a lower surface of the projection 161, a projecting portion 46C ( Fig. 4) that engages or fits with the recessed portion 46B is provided at the upper end portion of the shear blade rotating shaft 46, which has a substantially cylindrical shape. In a plan view, the cross-sectional shape of the protruding portion 46C is a substantially rectangular shape or a substantially square shape, and is a congruent shape with the cross-sectional shape of the recessed portion 46B, or a similar shape that is slightly smaller than the cross-sectional shape of the recessed portion 46B. Furthermore, in a plan view, at a center of the protruding portion 46C, an attachment hole 46D is provided that communicates with the attachment hole 46A of the projection 161.The shear blade rotating shaft 46 and the shear blade 16 (protrusion 161) are fixed by screws (not shown) fastened to the attachment hole 46A and the attachment hole 46D in a state where the protruding portion 46C in the upper portion of the shear blade rotating shaft 46 is inserted into the recessed portion 46B in the lower portion of the projection 161. Therefore, the shear blade rotating shaft 46 and the shear blade 16 can be rotated integrally.

[0034] The blade portion 17 is fixed to the projection 161, for example, by welding. Moreover, the blade portion 17 may be directly fixed to the shear blade rotating shaft 46 by welding or the like without using the projection 161. A normal direction of a stirring surface (face) of each of the plate-shaped blade portions 17A and 17B is oriented with respect to both the axial direction (the up-down direction in Fig. 2) the shear blade rotating shaft 46 and the rotation direction (a rotation direction around the shear blade rotating shaft 46) of each of the blade portions 17A and 17B are inclined. The stirring blade or the shear blade including the blade portion 17 is sometimes referred to as an inclined paddle blade. For example, it is preferable that an angle formed between the normal direction of the stirring surface of each of the blade portions 17A and 17B and the axial direction of the shear blade rotating shaft 46 is equal to or less than 15 degrees (an angle formed with respect to the rotation direction of each of the blade portions 17A and 17B is equal to or greater than 75 degrees). As a result, the stirring surface of each of the blade portions 17A and 17B is substantially parallel to the bottom portion 22 of the stirring tank 12 (the angle is equal to or less than 15 degrees). Therefore, the fluid resistance of the stirring surface during rotation is reduced.Therefore, it is possible to drive the blade portion 17 with a relatively low power even if the diameter of the blade portion 17 is increased, and it is possible to prevent an increase in the size or cost of the shear blade drive unit 47. Furthermore, since the blade portion 17 is inclined as described above, the blade portion 17 is less likely to idle even in a case where a fluid with high thixotropy or a fluid with low stirring ability is used. Therefore, shearing efficiency or refining efficiency is improved.

[0035] Since the shearing blade 16 or the blade portion 17 having a non-disk shape has a relatively small load capacity, it is possible to increase the blade diameter. Moreover, since the shearing blade 16 or the blade portion 17 is light in weight, it is easy to maintain a rotational balance. Therefore, the blade diameter of the blade portion 17 in an extension direction (the distance between a left end of the blade portion 17A and a right end of the blade portion 17B in the radial direction in Fig. 2 and Fig. 3) between 35% and 85% of the vessel diameter D of the agitated vessel 12, preferably between 45% and 75%, and more preferably between 50% and 70% of the vessel diameter D of the agitated vessel 12. Therefore, the shearing range can be larger than that of the disc-shaped agitating blade according to the prior art, and the shearing efficiency or the Refinement efficiency is improved.

[0036] Furthermore, in the disc-shaped agitating blade according to the prior art (for example, the dispersing blade disclosed in Patent Literature 1), the interior of the agitating vessel is divided into upper and lower portions by the disc portion, which significantly hinders the flow of the fluid. As a result, especially in a solution with high viscosity, liquid accumulation is likely to form on the underside of the disc portion. In contrast, according to the present embodiment, since the non-disc-shaped shearing blade 16 including the blade portion 17 extending from the shearing blade rotating shaft 46 to the side wall 12a of the agitating vessel 12 is used, the agitating vessel 12 is not divided into the upper and lower portions, unlike the disc-shaped agitating blade according to the prior art.Therefore, even if the blade diameter of the blade portion 17 of the shearing blade 16 is increased, the fluid flow is not significantly obstructed by the fluid blade 14 or the gate blade 18. As described above, the flow generated by the fluid blade 14 and the gate blade 18 can easily reach the shearing blade 16, whose diameter can be increased compared to the prior art. Therefore, even a fluid with high viscosity is effectively sheared or stirred.

[0037] As described above, the shearing blade 16 or the entire stirring device 10 according to the present embodiment is suitable for shearing or refining a fluid having a relatively high viscosity (a fluid with a viscosity of at least 1,000 cP or more, for example, a fluid with a viscosity of 10,000 cP or more). Any fluid (oil, paint, rubber, a polymer solution, a molten resin, or the like) containing fine particles of carbon black, silica, or the like is cited as an example of the high-viscosity fluid. The fine particles of carbon black or the like form agglomerates in the fluid and are efficiently refined and / or dispersed by the shearing blade 16 according to the present embodiment.

[0038] A width w ( Fig. 3) of the tip portion of the blade portion 17 in the rotation direction is preferably equal to or less than 5% of the vessel diameter D of the agitated vessel 12 in order to obtain suitable shearing performance or refining performance for the high-viscosity fluid. A distance h ( Fig. 1) between the blade portion 17 and the bottom portion 22 of the stirring vessel 12 is preferably equal to or smaller than 15% of the vessel diameter D of the stirring vessel 12 in order to obtain the desired stirring performance in the bottom portion 22 of the stirring vessel 12 in which the fluid to be stirred often settles and the discharge port through which the stirred fluid is discharged is often provided.

[0039] The present invention has been described above based on the embodiment. Combinations of the respective components and the respective processes in the embodiment as an example can be modified in various ways, and it will be apparent to those skilled in the art that the modifications are included within the scope of the present invention.

[0040] For example, the shape of the agitating blade according to the present invention is not limited to the shape of the shearing blade 16 shown in the embodiment. To achieve at least some of the effects of the present invention, the agitating blade provided between the bottom portion of the agitating tank and the fluid blade may have any non-disc shape, including one or more blade portions extending from the rotating shaft of the agitating blade to the side wall of the agitating tank.

[0041] Furthermore, the configuration, operation, and function of each device and method described in the embodiment may be implemented by hardware resources or software resources, or by cooperation between the hardware resources and the software resources. For example, a processor, a ROM, a RAM, and various integrated circuits may be used as the hardware resources. For example, programs such as an operating system and applications may be used as the software resources. Industrial applicability

[0042] The present invention relates to a stirring device and the like. List of reference symbols 10 Stirring device 12 mixing tanks 12a side wall 14 Fluid sheet 16 shaving blades 17 leaf section 18 Door leaf 20 ton section 21 Flange section 22 floor section 34 Fluid blade rotating shaft 46 Shear blade rotating shaft 47 Shear blade drive unit 52 Gate leaf rotating shaft QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2017 / 002905

[0003]

Claims

[1] Stirring device comprising: a stirred vessel that holds a fluid; a fluid blade that is rotated to allow the fluid to flow in the stirred tank; and a stirring blade provided between a bottom portion of the stirring vessel and the fluid blade, is rotated to stir the fluid, and a blade portion extending from a rotating shaft of the stirring blade to a side wall of the stirring vessel. [2] The stirring device according to claim 1, wherein at least a portion of the fluid blade is rotated between a tip portion of the blade portion and the side wall of the stirring vessel. [3] The stirring device according to claim 1 or 2, wherein a normal direction of a stirring surface of the blade portion is inclined with respect to both an axial direction of the rotary shaft and a rotation direction of the blade portion. [4] The stirring device according to claim 3, wherein an angle formed between the normal direction of the stirring surface of the blade portion and the axial direction is equal to or smaller than 15 degrees. [5] A stirring device according to claim 1 or 2, wherein a blade diameter of the blade portion in an extending direction is between 50% and 70% of a container diameter of the stirring container. [6] The stirring device according to claim 1 or 2, wherein a width of a tip portion of the blade portion is equal to or smaller than 5% of a container diameter of the stirring container. [7] The stirring device according to claim 1 or 2, wherein a distance between the blade portion and the bottom portion of the stirring vessel is equal to or less than 15% of a vessel diameter of the stirring vessel. [8] A stirring device according to claim 1 or 2, wherein the bottom portion of the stirring vessel has a flat shape. [9] A stirring device according to claim 8, wherein the flat bottom portion of the stirring vessel is attachable to a flange portion formed in a bottom portion of a cylindrical side wall of the stirring vessel. [10] A stirring device according to claim 1 or 2, wherein the rotary shaft of the stirring blade extends from the bottom portion of the stirring tank into the stirring tank. [11] The stirring device according to claim 1 or 2, wherein a rotary shaft of the fluid blade extends from an upper portion of the stirring tank into the stirring tank. [12] The stirring device according to claim 1 or 2, wherein a rotational speed of the stirring blade is higher than a rotational speed of the fluid blade. [13] The stirring device according to claim 1 or 2, wherein the rotating shaft of the stirring blade and a rotating shaft of the fluid blade are provided on the substantially same straight line. [14] Stirring process comprising: Rotating a fluid blade to cause a fluid to flow in a stirred vessel; and Rotating a stirring blade provided between a bottom portion of the stirring vessel and the fluid blade and including a blade portion extending from a rotating shaft of the stirring blade to a side wall of the stirring vessel at a higher speed than the fluid blade to stir the fluid.

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