JP2016013511A - Mixing apparatus and mixing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mixing apparatus exhibiting excellent mixability and solubility.SOLUTION: A mixing apparatus is provided with an agitation vessel for storing solid content and a liquid, an agitation blade inside the agitation vessel, a drive member for rotating the agitation blade, and a power source which is connected to the drive member and applies a current on the drive member. The power source can change a direction of the current applied on the drive member. The drive member can change a rotation direction of the agitation blade by changing the direction of the applied current.

Description

  The present invention relates to a mixing apparatus and a mixing method.

  In the case of producing a solid and liquid mixture such as a polymer-containing varnish, a method of obtaining a mixture by stirring the solid and liquid, for example, resin, filler, solvent, etc. in a mixing apparatus is generally carried out (patent) Reference 1).

JP 2011-62581 A

  However, in the conventional stirring method, the solubility is insufficient, and the solid content may remain without being dissolved. An object of the present invention is to provide a mixing apparatus having excellent mixing properties (solubility).

  As a result of intensive studies, the present inventors have found that in the conventional stirring method, the above-described problem occurs due to constant convection. Therefore, the ship's screw propeller was used as a reference as a method of affecting the convection. The screw propeller of a ship can vary the pitch (angle) of the stirring blades provided on the propeller, and can vary the convection by adjusting the pitch angle according to the forward and backward movement of the ship. However, although the method of changing the pitch like a ship was examined, it was difficult to mount the pitch variable device on a small agitator compared to the ship.

  As a result of further investigations, the present inventors have found that the above-described problem occurs in the conventional stirring method due to the fact that the stirring direction is one direction. That is, if the solid content is a high specific gravity substance, it tends to settle to the bottom, and if it is a low specific gravity substance, it tends to float on the liquid surface, but if the stirring direction is one direction, the convection direction is only one direction, It has been found that the solubility is insufficient because the salt remains locally and is not sufficiently taken into the mixed solution. For example, in the case of a polymer-containing varnish (high specific gravity substance), the polymer precipitated at the bottom may be discharged as a dissolution residue in the extraction inspection.

  The present inventors have found that the solubility can be improved by an apparatus capable of changing the rotation direction of the stirring blade and the convection direction of the mixture without using a large-scale apparatus such as a pitch variator, and completed the present invention. did.

According to the present invention, the following mixing apparatus and the like are provided.
1. A stirred tank containing solids and liquid,
A stirring blade inside the stirring tank,
A mixing device comprising a driving member for rotating the stirring blade, and a power source connected to the driving member and applying a current to the driving member;
The power source can change the direction of current applied to the driving member,
The driving device is a mixing device that can change the direction of rotation of the stirring blade by changing the direction of the applied current.
2. 2. The mixing apparatus according to 1, wherein the stirring blade is provided so that a longitudinal axis of the stirring blade is substantially parallel to a liquid surface of the liquid when the solid content and the liquid are stored in the stirring tank. .
3. 3. The mixing apparatus according to 1 or 2, wherein, when the solid content and the liquid are stored in the stirring tank, the convection direction of the solid content and the liquid can be changed by changing the rotation direction of the stirring blade.
4). The mixing apparatus in any one of 1-3 whose specific gravity of the said solid content is 1.1-3.0.
5. The mixing apparatus in any one of 1-4 used in order to stir the photosensitive resin composition.
6). The solid content and liquid are stored in the stirring tank,
By applying a current from the power source to the driving member, the stirring blade in the stirring tank is rotated to mix the solid and the liquid while stirring,
A mixing method in which the solid component and the liquid are mixed while being stirred by changing the direction of the current applied to the driving member by the power source to change the rotation direction of the stirring blade.
7). 7. The mixing method according to 6, wherein a convection direction of the solid content and the liquid is changed by changing a rotation direction of the stirring blade.
8). The solid content and liquid are stored in the stirring tank,
A mixing method of mixing the solid content and the liquid while stirring by rotating a stirring blade in the stirring tank by applying a current from a power source to a driving member,
The mixing method in which the convection direction of the solid content and the liquid generated by the rotation of the stirring blade is a direction from the bottom surface of the stirring tank toward the liquid surface in the rotation center portion of the stirring blade.
9. 9. The mixing method according to 8, wherein the liquid level is higher than the lowermost part of the stirring blade and lower than the uppermost part of the stirring blade in a state where the stirring blade is stopped.

  ADVANTAGE OF THE INVENTION According to this invention, the mixing apparatus excellent in mixing property (solubility) can be provided.

It is the schematic which shows the mixing apparatus of this invention. It is the schematic which shows operation | movement of the mixing apparatus of this invention. It is the schematic at the time of mixing a low specific gravity material using the mixing apparatus of this invention. It is the schematic at the time of mixing a high specific gravity material using the mixing apparatus of this invention. It is the schematic at the time of stirring by reducing the preparation amount using the 2nd mixing method of this invention. It is the schematic at the time of stirring by reducing the preparation amount by the conventional mixing method.

The mixing device of the present invention is connected to a stirring tank that contains solid content and liquid, a stirring blade in the stirring tank, a driving member for rotating the stirring blade, and the driving member, and applies an electric current to the driving member. A power supply is provided.
The power source can change the direction of the current applied to the driving member, and the driving member can change the rotation direction of the stirring blade by changing the direction of the applied current.
Hereinafter, although the present invention is explained in detail using a drawing, the present invention is not limited to this.

A schematic diagram of the mixing apparatus of the present invention is shown in FIG.
The mixing apparatus 1 includes a stirring tank 10 that contains solids and liquid, a stirring blade 12 in the stirring tank 10, a stirring rod (shaft) 14 that transmits power to the stirring blade 12, and a drive for rotating the stirring blade 12. A member 20, a power source 30 that is connected to the driving member 20 and applies a current to the driving member 20, and a control panel 40 that controls the power source 30 are provided.
The stirring blade 12 is normally provided so that the axis in the longitudinal direction of the stirring blade 12 is substantially parallel to the liquid surface when the solid content and the liquid are stored in the stirring tank 10.

  The control panel 40 is for controlling the frequency and the direction of application of the power supply 30, but the control panel 40 may not be provided as long as the power supply 30 can control the rotation speed and the rotation direction. Further, for example, when the stirring blade 12 is directly connected to the driving member 20 or when the stirring blade 12 is driven by magnetism or the like, the stirring rod (shaft) 14 may not be provided.

  There is no restriction | limiting in particular as the stirring tank 10 and the stirring rod 14, A well-known thing can be used. The drive member 20 is not particularly limited as long as the rotation speed and the rotation direction can be changed. For example, a cyclo reducer (manufactured by Sumitomo Heavy Industries, Ltd.) can be used.

As the stirring blade 12, when the solid content and the liquid are stirred, in the rotation center portion of the stirring blade, the direction perpendicular to the rotation surface of the rotation blade, that is, the direction from the bottom surface of the stirring tank to the liquid surface, or the liquid A thing which can generate a convection in the direction which goes to a stirring tank bottom face from a surface, and can change the direction is used. With such a stirring blade, the convection direction can be varied (bidirectional).
As such a stirring blade, for example, a propeller blade and a paddle blade (paddle blade) can be used. The inclination angle of the wing is not particularly limited as long as axial convection can be generated, but is usually preferably 30 to 60 °, and more preferably 40 to 50 °.

  The power supply 30 is not particularly limited as long as the frequency and the direction of applied current are variable. For example, an inverter FREQROL-800 (manufactured by Mitsubishi Electric Corporation) can be used.

  The control panel 40 is not particularly limited as long as the frequency of the power supply 30 and the applied current direction are variable. For example, PLC (Programmable Logic Controller) and DCS (Distributed Control System) are mentioned. When the control panel 40 is used, commands to the drive member 20 can be integrated into commands from the control panel, which is preferable in terms of centralized management.

Next, operation | movement of the mixing apparatus 1 is demonstrated using FIG.
When the solid content and the liquid are mixed by the mixing device 1, the solid content and the liquid are accommodated in the stirring tank 10, and a current is applied to the driving member 20 by the power supply 30 to drive the stirring blade 12. As the stirring blade 12 rotates, convection occurs in the solid content and the liquid, and these are stirred and mixed. The solid content is not shown.

The convection direction of the solid content or the like can be changed depending on the rotation direction of the stirring blade 12. For example, when the shaft 14 and the stirring blade 12 are rotated in the direction of the arrow A (forward rotation), the solid content or the like rotates in the direction of the arrow B, that is, from the liquid surface to the bottom surface in the rotation center portion of the stirring blade 12. Convection in the direction from the bottom to the liquid surface at the circumference. Further, when the shaft 14 and the stirring blade 12 are rotated in the direction opposite to the arrow A (reverse rotation), the solid content and the like are directed in the direction opposite to the arrow B, that is, from the bottom surface to the liquid level in the rotation center portion of the stirring blade 12. Convection in a direction from the liquid surface to the bottom surface (not shown) on the rotation circumference.
Note that “forward rotation” refers to the direction of rotation of the stirring blade such that the solid content convects in the direction of arrow B, and “reverse rotation” is the opposite, ie, the solid content is opposite to arrow B. The direction of rotation of the stirring blade that convects in the direction of.

  The rotating direction of the stirring blade 12 can be appropriately changed by the power source 30 or the power source 30 controlled by the control panel 40. Therefore, sufficient stirring and mixing are possible by appropriately determining the convection direction according to the mixing conditions such as the specific gravity of the solid content.

Next, mixing when a low specific gravity material is used as a solid content and when a high specific gravity material is used will be described.
First, the case where a low specific gravity material is used will be described with reference to FIG.
When a low specific gravity material (white circle in the figure) is introduced into the stirring tank 10 in which the solvent has been introduced, the low specific gravity material floats on the liquid surface of the solvent due to the specific gravity difference. In this case, it is preferable to generate the convection in the direction B with the rotation of the stirring blade 12 as the positive rotation A. By this convection, the low specific gravity material floating on the liquid surface can be transported toward the bottom surface, and mixing can be performed efficiently. On the other hand, when the stirring blade 12 is rotated in the reverse direction, the low specific gravity material floating on the liquid surface remains on the liquid surface as a result of the convection rising from the rotation center of the stirring blade 12 and cannot be guided into the solution. There is a possibility that mixing cannot be performed sufficiently.

The case where a high specific gravity material is used will be described with reference to FIG.
When a high specific gravity material (black circle in the figure) is charged into the stirring tank 10 in which the solvent is charged, the high specific gravity material starts to settle to the bottom surface due to the difference in specific gravity, and all sinks to the bottom surface after a certain period of time. In this case, it is preferable that the stirring blade 12 is rotated in the reverse direction C to generate convection in the liquid surface direction D. By this convection, the high specific gravity material that sinks to the bottom surface can be transported in the liquid surface direction, and can be efficiently stirred and mixed. On the other hand, when the stirring blade 12 is rotated in the forward direction, the high specific gravity material that has settled to the bottom surface remains on the bottom surface as it is, and cannot be guided into the solution, and stirring and mixing may not be performed efficiently.

  Moreover, when both high specific gravity material and low specific gravity material are included, any material can fully be mixed by repeating forward rotation and reverse rotation suitably (not shown).

  The mixing apparatus of this invention can change freely the convection directions, such as solid content, by changing the stirring direction. Therefore, the convection direction can be appropriately selected and changed according to the specific gravity of the material, and mixing can be performed under optimum conditions. In addition, since the inside of the mixing vessel can be made more turbulent by repeatedly changing the convection direction, sufficient mixing is possible even when both high-density material and low-density material are included.

There is no restriction | limiting in particular in the material mixed with the apparatus of this invention.
Examples of the low specific gravity material include those having a specific gravity of 0.7 to 1.0. Examples of the high specific gravity material include those having a specific gravity of 1.1 to 3.0, and those having a specific gravity of 1.2 to 1.5 are often used.
These materials include inorganic fillers such as calcium carbonate, alumina, titanium oxide, mica, aluminum carbonate, aluminum hydroxide, magnesium silicate, aluminum silicate, silica, short glass fiber, aluminum borate whisker, and silicon carbide whisker. Is mentioned.
Examples of the solvent include NMP (N-methyl-2-pyrrolidone) and γ-butyrolactone.

Examples of the mixture (composition) to be produced include a polymer-containing varnish, a paint, a liquid abrasive, and an adhesive. The mixing apparatus of the present invention can be suitably used particularly when producing a polymer-containing varnish.
For example, when a polymer-containing varnish (photosensitive resin composition) is produced as a mixture, these are mixed using a solid material (specific gravity 2.1) or the like with respect to NMP (specific gravity 1.1) as a solvent.

Next, the mixing method of the present invention will be described.
In the first mixing method of the present invention, the solid content and the liquid are accommodated in the agitation tank, and the current is applied from the power source to the driving member, whereby the agitation blade in the agitation tank is rotated and the solid content and the liquid are collected. Mixing while stirring, changing the direction of the current applied to the drive member by the power supply, changing the rotation direction of the stirring blade to rotate, and mixing the solid and liquid while stirring.
The first mixing method can be performed using the above-described mixing apparatus of the present invention. The conditions of each apparatus etc. are the same as the above.

  The first mixing method of the present invention is characterized in that the convection direction is switched by switching the rotation direction of the stirring blade, and thereby sufficient agitation without generating a residue or the like is possible.

The rotation direction may be switched only once or a plurality of times. For example, it is performed once or twice. Moreover, each stirring time is 10 to 30 minutes, for example.
Although there is no restriction | limiting in particular in the rotational speed of a stirring blade, Usually, 100-200 rpm is preferable and 130-170 rpm is more preferable.

In the second mixing method of the present invention, the solid content and the liquid are accommodated in the stirring tank, and the stirring blade in the stirring tank is rotated (reversely rotated) by applying an electric current from the power source to the driving member. Mix minutes and liquid with stirring.
In this method, the convection direction of the solid and the liquid generated by the rotation of the stirring blade is a direction from the bottom surface of the stirring tank toward the liquid surface at the rotation center portion of the stirring blade.

  The difference between the second mixing method and the first mixing method is that reverse rotation is used, that is, only convection in the direction from the bottom surface of the stirring tank toward the liquid surface is used at the rotation center portion of the stirring blade. It is. Further, the power source is not limited to a variable applied current, and a known power source can be used. Other conditions are the same as those in the first mixing method.

According to the second mixing method, the raw material charge amount (minimum charge amount) can be reduced. As explained below, if the liquid level reaches the bottom of the stirring blade while the stirring blade is stopped, mixing can be performed even if the liquid level does not reach the top of the stirring blade. is there.
As shown in FIG. 5, in the second mixing method, the stirring blade 12 rotates in the reverse direction (direction C), so that convection in the upward direction D is generated at the center of rotation. As a result of solids and the like being supplied from the inside of the liquid in the liquid level direction by this convection, the liquid level rises. As the liquid level rises, convection is ensured, so that sufficient mixing is possible, and solid matter does not accumulate on the stirring blade 12.

  The height of the liquid level may be higher than the lowermost part of the stirring blade. For example, the height from the lower end of the stirring blade to the upper portion of the lower end of the stirring blade is preferably ¼ or more and preferably ½ or more.

In the conventional stirring method, since the mixing operation is performed only by convection in the bottom direction (forward rotation), the mixed liquid needs to reach the upper part of the stirring blade as described below.
In the case of convection in the bottom direction, since the mixed liquid is filled up to the top of the stirring blade and no flow is generated from the top of the stirring blade to the bottom, axial flow does not occur. (FIG. 6). In addition, when the material is charged, it accumulates on the upper part of the stirring blade, resulting in poor dissolution.

  In promoting batch process production, the production of small and high-mix products is on the rise due to market trends. Since the 2nd mixing method of this invention can reduce the minimum preparation amount of material, it is especially useful for small-quantity multi-product production.

  According to the mixing apparatus of the present invention, a mixed liquid such as a polymer-containing varnish can be efficiently produced.

DESCRIPTION OF SYMBOLS 1 Mixing apparatus 10 Agitation tank 12 Agitation blade 14 Agitation rod 20 Drive member 30 Power supply 40 Control panel A Rotation direction (forward rotation)
B Convection direction C Rotation direction (reverse rotation)
D Convection direction

Claims (9)

A stirred tank containing solids and liquid,
A stirring blade inside the stirring tank,
A mixing device comprising a driving member for rotating the stirring blade, and a power source connected to the driving member and applying a current to the driving member;
The power source can change the direction of current applied to the driving member,
The driving device is a mixing device that can change the direction of rotation of the stirring blade by changing the direction of the applied current.   The said stirring blade is provided so that the axis | shaft of the longitudinal direction of the said stirring blade may become substantially parallel to the liquid level of the said liquid, when solid content and a liquid are accommodated in the said stirring tank. Mixing equipment.   3. The mixing apparatus according to claim 1, wherein when the solid content and the liquid are stored in the stirring tank, the convection direction of the solid content and the liquid can be changed by changing a rotation direction of the stirring blade.   The mixing device according to any one of claims 1 to 3, wherein the solid has a specific gravity of 1.1 to 3.0.   The mixing device according to any one of claims 1 to 4, which is used for stirring the photosensitive resin composition. The solid content and liquid are stored in the stirring tank,
By applying a current from the power source to the driving member, the stirring blade in the stirring tank is rotated to mix the solid and the liquid while stirring,
A mixing method in which the solid component and the liquid are mixed while being stirred by changing the direction of the current applied to the driving member by the power source to change the rotation direction of the stirring blade.   The mixing method according to claim 6, wherein a convection direction of the solid content and the liquid is changed by changing a rotation direction of the stirring blade. The solid content and liquid are stored in the stirring tank,
A mixing method of mixing the solid content and the liquid while stirring by rotating a stirring blade in the stirring tank by applying a current from a power source to a driving member,
The mixing method in which the convection direction of the solid content and the liquid generated by the rotation of the stirring blade is a direction from the bottom surface of the stirring tank toward the liquid surface in the rotation center portion of the stirring blade.   The mixing method according to claim 8, wherein a height of the liquid surface is higher than a lowermost portion of the stirring blade and lower than an uppermost portion of the stirring blade in a state where the stirring blade is stopped.

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