JP2019167592A - Mixing device - Google Patents

Abstract

To provide a mixing device designed so as to catch valve action metal particles without reducing an exhaust efficiency to prevent the valve action metal particles from flowing into an exhaust duct.SOLUTION: A mixing device includes: a mixing part mixing valve action metal particles, binder resin and solvent capable of dissolving the binder resin together and generating first gas containing a part of the valve action metal particles and at least part of the solvent; a separation part separating the valve action metal particles from the first gas; an inside duct exhausting the first gas from the mixing part and guiding the gas to the separation part; and an exhaust duct exhausting second gas generated by separating the valve action metal particles from the first gas in the separation part to the outside of the separation part. The separation part includes: a container into which the first gas is guided; fluid stored so as to occupy part of the inside space of the container and having a specific gravity smaller than that of the valve action metal particles. The edge part of the inside duct on the separation part is disposed in the fluid.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a mixing device, and more particularly to a mixing device used when mixing raw materials of a porous sintered body used for an electrolytic capacitor.

  A porous sintered body used for an electrolytic capacitor is usually produced by pressure-molding and sintering a powdery raw material obtained by mixing valve action metal particles and a binder resin. Since the binder resin is uniformly mixed with the valve action metal particles, the binder resin is usually stored in a mixing container together with a solvent capable of dissolving the binder resin particles. Mixing is performed while removing the solvent. Thereby, a powdery raw material is obtained. For mixing the valve action metal particles and the binder resin, for example, a granulator as shown in Patent Document 1 is used.

JP-A-9-78101

  The solvent is vaporized by heating, for example, and is forcibly exhausted from the mixing container. Since the particle diameter of the valve action metal particles is very small, it easily rises into the mixing container due to the influence of the mixing process or exhaust. Therefore, a part of the valve action metal particles is discharged out of the container together with the solvent.

  The valve action metal particles that have flowed into the exhaust duct together with the gas containing the solvent accumulate in the exhaust duct. This is because valve action metal particles generally have a large specific gravity. For this reason, the exhaust efficiency tends to decrease.

  In Patent Document 1, a bag filter is installed between a mixing container and a discharge duct, and exhausting is performed while capturing valve action metal particles. However, such a filter is likely to be clogged, and the exhaust resistance is likely to increase. Therefore, the exhaust efficiency is lowered, and the mixing efficiency of the valve action metal particles and the binder is also lowered.

  The first aspect of the present invention comprises mixing valve action metal particles, a binder resin, and a solvent capable of dissolving the binder resin, and at least part of the valve action metal particles and at least a part of the solvent. A mixing unit that generates a first gas, a separation unit that separates the valve metal particles from the first gas, and an internal duct that discharges the first gas from the mixing unit and introduces the first gas into the separation unit. And a discharge duct for discharging the second gas generated by the separation of the valve metal particles from the first gas in the separation unit to the outside of the separation unit, the separation unit, A container into which the first gas is introduced; and a liquid that is accommodated so as to occupy a part of the internal space of the container and has a specific gravity smaller than that of the valve-acting metal particles. Part placed in the liquid It is directed to the mixing device.

  According to the present invention, it is possible to capture the valve metal particles without reducing the exhaust efficiency and suppress the inflow of the valve metal particles into the discharge duct.

It is sectional drawing which shows notionally the mixing apparatus which concerns on one Embodiment of this invention. It is a perspective view of the perforated panel concerning one embodiment of the present invention.

  In the present embodiment, a separation unit that removes the valve metal particles is disposed between the mixing container and the discharge duct. And the valve action metal particle which rose in the mixing container is once introduced into a separation part with the gas containing the solvent which should be discharged | emitted from a mixing container. In the separation unit, the valve metal particles are removed from the introduced gas, and the gas after the valve metal particles are removed is quickly discharged from the discharge duct to the outside. Thereby, inflow to the discharge duct of valve action metal particles can be controlled, maintaining the exhaust resistance in a mixing container small.

  That is, the mixing device according to the present embodiment mixes the valve action metal particles, the binder resin, and a solvent capable of dissolving the binder resin (hereinafter referred to as a first solvent), and the valve action metal particles. A separation unit that generates a first gas including a part and at least a part of the first solvent, a separation unit that separates the valve metal particles from the first gas, and a first gas that is discharged from the mixing unit for separation. And an exhaust duct for discharging the second gas generated by separating the working metal particles from the first gas in the separation part to the outside of the separation part.

  The mixing unit includes a first container that contains the valve action metal particles, the binder resin, and the first solvent. Each material is mixed in the first container. The first container is provided with a first outlet that communicates with the internal duct. The mixing unit may include a heater for vaporizing the first solvent by heating.

  The separation portion is a container (second container) into which the first gas is introduced via the internal duct, a liquid that is accommodated so as to occupy a part of the internal space of the second container, and has a smaller specific gravity than the valve action metal particles. . The second container is provided with an insertion port into which the internal duct is inserted, and a second discharge port that communicates the remaining portion (space S) of the internal space with the discharge duct.

  An end portion (hereinafter referred to as a first end portion) on the separation portion side of the internal duct is disposed in the liquid. Therefore, in the separation unit, the first gas is directly introduced into the liquid in the second container from the internal duct. Thereby, the valve action metal particle contained in 1st gas settles in the liquid with smaller specific gravity. On the other hand, the other components contained in the first gas become bubbles as they are and are discharged from the liquid into the space S of the second container. The gas (second gas) released into the space S is discharged to the outside through the discharge duct. That is, in the separation unit, the liquid contained in the second container (hereinafter sometimes referred to as a separation liquid) serves as a filter to separate the valve metal particles from the first gas. The space S of the second container may be decompressed. Thereby, the second gas is further easily released from the separation liquid into the space S.

  The first gas contains, for example, the vaporized first solvent, the atmosphere, and the like in addition to the valve action metal particles. The vaporized first solvent may be dissolved in the separation liquid. The second gas is a gas that remains after the valve action metal particles are removed from the first gas, and in some cases, a part of the components is dissolved in the separation liquid.

  In a preferred embodiment, the second container includes a perforated panel arranged in a direction along the liquid surface of the separation liquid. In this case, the second gas once hits the perforated panel, and then is gradually released into the space S through a plurality of holes (first holes) provided in the perforated panel. Thereby, the change of the internal pressure of the space S becomes small.

  The second container communicates with the internal duct. For this reason, the change in the internal pressure of the space S affects the suction force of the internal duct. For example, when large bubbles are released into the space S at a time, the internal pressure of the second container rapidly increases and the suction force of the internal duct decreases. This reaction causes the internal pressure of the space S to drop rapidly. Then, the suction | attraction force of an internal duct raises, the quantity of the valve action metal particle contained in the discharged | emitted 1st gas increases, and a yield may fall. By gradually releasing the second gas into the space S, a change in the internal pressure of the space S is suppressed, and as a result, fluctuations in the suction force of the internal duct can be suppressed.

  The perforated panel may be disposed in the separation liquid. At this time, the first end of the internal duct is disposed at a position closer to the bottom of the second container than the perforated panel. Since the second gas hits the perforated panel in the separation liquid, the bubbles are likely to become even smaller. The opening area per one of the plurality of first holes provided in the perforated panel is preferably smaller than the area of the opening at the first end of the internal duct.

  Hereinafter, a mixing apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view conceptually showing a mixing apparatus according to this embodiment. FIG. 2 is a perspective view of the perforated panel according to the present embodiment. In FIG. 1, the gas flow is indicated by arrows. In FIG. 2, only a part of the first holes is shown for convenience.

  The mixing apparatus 100 includes a mixing unit 10, a separation unit 20, an internal duct 30 that connects the mixing unit 10 and the separation unit 20, and a discharge duct 50 that is connected to the separation unit 20.

(Mixing part)
The mixing unit 10 includes a first container 11.
The first container 11 contains the valve action metal particles 41, the binder resin, and the first solvent. The first container 11 is provided with a first discharge port 11 a and an intake port 11 b that communicate with the internal duct 30.

  The first container 11 includes a mechanism for mixing the valve action metal particles 41, the binder resin, and the first solvent (hereinafter may be collectively referred to as a container 40). 11 to mix. The mechanism for mixing the contents 40 of the first container 11 is not particularly limited. For example, the first container 11 itself may be rotatable, or a stirring mechanism may be provided inside the first container 11. The first container 11 also includes a mechanism for vaporizing the first solvent. The mechanism for vaporizing the first solvent is not particularly limited, and may be heating or reduced pressure. When the first solvent is vaporized by heating, a heater (not shown) for heating the first container 11 is disposed. The heating temperature is not particularly limited, and may be set as appropriate in consideration of the boiling point of the first solvent, the decomposition temperature of the binder resin, and the like. When the contents 40 are mixed and the first solvent starts to vaporize, a first gas containing the valve action metal particles 41 and the vaporized first solvent is generated in the first container 11.

  Examples of the valve action metal particles 41 include titanium (Ti), tantalum (Ta), niobium (Nb), and the like. The valve action metal particles 41 may be an alloy made of two or more metals. The alloy includes, for example, a valve metal, silicon, vanadium, boron and the like. A compound containing a valve metal and a typical element such as nitrogen may be used. When the valve action metal particle 41 contains tantalum having a large specific gravity, the mixing apparatus 100 of the present embodiment is particularly useful.

  The valve action metal particles subjected to the mixing treatment are usually aggregated to form secondary particles. The average particle diameter D50 of the secondary particles of the valve action metal particles 41 is, for example, 0.01 μm to 0.5 μm. The secondary particles are pulverized by the mixing process to generate fine powder having an average particle diameter D50 of about 0.01 μm or less. Such fine powder is contained in the first gas. The average particle diameter D50 is a median diameter in a volume particle size distribution obtained by a laser diffraction type particle size distribution measuring apparatus.

  It does not specifically limit as binder resin, For example, an acrylic resin etc. are mentioned. The binder resin may be accommodated in the first container 11 after being dissolved in the first solvent in that the uniformity of mixing is further increased.

  The first solvent is not particularly limited as long as it can dissolve the binder resin, and may be appropriately selected according to the binder resin. Among these, a solvent having a low boiling point is preferable so that it can be easily vaporized. Examples of such a solvent include methanol, ethanol, methyl acetate, ethyl acetate, toluene and the like. You may use these individually or in combination of 2 or more types.

(Separation part)
The separation unit 20 includes a second container 24 into which the first gas is introduced via the internal duct 30, and a separation liquid 22 that is accommodated so as to occupy a part of the internal space of the second container 24. The specific gravity of the separation liquid 22 is smaller than the specific gravity of the valve action metal particles 41. The second container 24 is provided with an insertion port 24a into which the internal duct 30 is inserted, and a second discharge port 24b that allows the space S other than the separation liquid 22 in the internal space to communicate with the discharge duct 50. .

  The second container 24 includes a perforated panel 21. The main surface of the perforated panel 21 is disposed in the separation liquid 22 in a direction along the liquid surface 22 a of the separation liquid 22. However, the perforated panel 21 may be disposed such that only one main surface thereof is in contact with the liquid surface 22a, or may be disposed above the liquid surface 22a. The angle formed between the main surface of the perforated panel 21 and the liquid surface 22a is not particularly limited. The perforated panel 21 may be arranged so that the second gas is discharged into the space S through the plurality of first holes 21 a provided in the perforated panel 21.

  The first end 30 a of the internal duct 30 is inserted from the liquid level 22 a to a position closer to the bottom of the second container 24 than the perforated panel 21. In FIG. 1, the insertion port 24a is provided above the second container 24, and the first end 30a is inserted into the separation liquid 22 through the space S and the liquid surface 22a. It is not limited to this. The insertion port 24 a may be provided below the second container 24 and at a position where the first end 30 a is directly inserted into the separation liquid 22.

  When the first gas is introduced into the separation liquid 22 from the first end 30a, at least a part of the valve action metal particles 41 contained in the first gas has a specific gravity smaller than that of the valve action metal particles 41. Sedimentation in Thereby, the valve action metal particle 41 is isolate | separated from 1st gas. At this time, some of the components contained in the first gas can be dissolved in the separation liquid 22. The separated valve metal particles 41 may be collected and reused after the separation liquid 22 is removed as necessary.

  On the other hand, the second gas becomes bubbles in the separation liquid 22 and once hits the perforated panel 21. Thereafter, the bubbles pass through the plurality of first holes 21 a provided in the perforated panel 21 to become finer bubbles and are discharged into the space S. The second gas discharged into the space S is discharged from the discharge duct 50 to the outside.

  The separation liquid 22 is not particularly limited as long as it is a liquid under the usage environment. Examples of the separation liquid 22 include alcohols such as water, ethylene glycol (EG), polyethylene glycol (PEG), propylene glycol, diethylene glycol monobutyl ether, glycerin, 1-propanol, butanol, polyglycerin, and isopropyl alcohol (IPA). Amides such as formaldehyde, N-methylacetamide, N, N-dimethylformamide, N-methyl-2-pyrrolidone, esters such as methyl acetate and γ-butyrolactone (γBL), ketones such as methyl ethyl ketone, 1,4 -Ethers such as dioxane, sulfur-containing compounds such as dimethyl sulfoxide and sulfolane, and carbonate compounds such as propylene carbonate. Among these, water is preferable as the separation liquid 22 because it is easily available and can be easily removed from the recovered valve metal particles 41. When the first gas contains a water-soluble component, the component can be dissolved in water (separation liquid 22). Tantalum is generally a water-inhibiting metal, but there is no particular problem because the amount contained in the first gas is very small.

The perforated panel 21 is a plate-like member having a plurality of through holes (first holes 21a). The shape of the opening when the first hole 21a is viewed from the normal direction of the main surface of the perforated panel 21 is not particularly limited, and may be a circle, a rectangle, or other shapes. The size of the opening of the first hole 21a is not particularly limited. The area A1 per one opening of the first hole 21a is preferably smaller than the area A2 of the opening of the first end 30a in that the bubbles are likely to become finer. A1 / A2 is, for example, 1/2 to 1/10. Area A1 is, for ^example, 0.5cm ² ~10cm 2. The plurality of first holes 21 a are preferably arranged in the entire perforated panel 21.

  The main surface of the perforated panel 21 may be large enough to cover the entire surface of the liquid surface 22a. In this case, the perforated panel 21 may be provided with a second hole 21b for inserting the first end 30a of the internal duct 30. The material of the perforated panel 21 is not particularly limited, and may be made of resin or metal such as stainless steel.

(duct)
The first end 30 a of the internal duct 30 is inserted into the separation liquid 22 from the insertion port 24 a of the second container 24. The other end of the internal duct 30 communicates with the first discharge port 11 a of the first container 11. The first gas generated in the first container 11 is introduced into the second container 24 through the internal duct 30.
The discharge duct 50 communicates with the second discharge port 24b of the second container 24, and discharges the second gas released into the space S of the second container 24 to the outside.

The mechanism for flowing each gas is not particularly limited. For example, a vacuum pump may be connected to the discharge duct 50. In this case, the space S of the second container 24 is decompressed by the discharge duct 50 sucking the second gas. Accordingly, the internal duct 30 sucks the first gas in the first container 11, and the first gas is introduced into the second container 24. In this case, the suction amount of the second gas by the discharge duct 50 is not particularly limited, for example, 0.02 m ³ / sec ~0.1m ³ / sec.

  The mixing apparatus according to the present invention is used, for example, for mixing raw materials of a porous sintered body used as an anode body of an electrolytic capacitor.

DESCRIPTION OF SYMBOLS 100: Mixing apparatus 10: Mixing part 11: 1st container 11a: 1st discharge port 11b: Intake port 20: Separation part 21: Perforated panel 21a: 1st hole 21b: 2nd hole 22: Liquid for separation 22a: Liquid Surface 24: 2nd container 24a: Insertion port 24b: 2nd discharge port 30: Internal duct 30a: 1st edge part 40: Containment 41: Valve action metal particle 50: Exhaust duct

Claims (6)

A mixing unit that mixes valve-acting metal particles, a binder resin, and a solvent capable of dissolving the binder resin, and generates a first gas including at least part of the valve-acting metal particles and the solvent. When,
A separation unit for separating the valve metal particles from the first gas;
An internal duct for discharging the first gas from the mixing section and introducing it into the separation section;
A discharge duct for discharging the second gas generated by the separation of the valve metal particles from the first gas in the separation unit to the outside of the separation unit;
The separation unit includes a container into which the first gas is introduced, and a liquid that is accommodated so as to occupy a part of the internal space of the container and has a specific gravity smaller than that of the valve metal particles.
An end of the internal duct on the separation part side is a mixing device arranged in the liquid.   The mixing apparatus according to claim 1, wherein the container further includes a perforated panel arranged in a direction along the liquid level of the liquid. The perforated panel is disposed in the liquid;
The mixing device according to claim 2, wherein an end of the internal duct on the side of the separation unit is disposed at a position closer to the bottom of the container than the perforated panel.   4. The mixing device according to claim 2, wherein an opening area per one of the holes of the perforated panel is smaller than an opening area of an end portion of the internal duct on the separation part side.   The mixing device according to claim 1, wherein the mixing unit includes a heater that heats the solvent. The said valve action metal particle is a mixing apparatus as described in any one of Claims 1-5 containing a tantalum.

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