JPWO2010074051A1 - Particle classification apparatus, classification system equipped with the same, and particle classification method - Google Patents

Abstract

A particle classification device capable of classifying particles efficiently and easily with high accuracy while minimizing stress on the particles without requiring complicated devices and complicated maintenance and management. A classification system and a particle classification method used are provided. It is an apparatus for classifying particles from the dispersion in the dispersion holding part, and has a connection channel to the dispersion holding part, a cone part, a straight body part and a discharge channel continuously in this order from the bottom side, This is a particle classifier that classifies particles by generating a circulating flow in the straight body part from the connection flow path to the discharge flow path.

Description

The present invention relates to a particle classification device, a classification system including the particle classification device, and a particle classification method. More specifically, the present invention relates to an apparatus for classifying particles from a dispersion such as a solid-liquid mixture, a classification system including the apparatus, and a method for classifying particles from a dispersion using the apparatus.

In fields such as chemical processes that handle solid-liquid mixtures, solid-liquid separation technology that separates dispersoids (particles) and dispersion media (liquid components) from dispersions such as solid-liquid mixtures is particularly important. Conventionally, techniques for classifying particles from a dispersion have been studied. As conventional particle classification technology, wet classification is mainly used. For example, a method using gravity (sediment classification), a method using centrifugal force (centrifugation), or a combination of these methods. The technology by is used.

Specifically, as a conventional particle classification method, for example, an inverted conical end plate portion is formed continuously from the opening edge on the lower end side of an upright cylindrical portion, and the axial direction of the inner wall is perpendicular to the bottom portion of the end plate portion. There is disclosed a wet classifier using sedimentation by weight, which has a structure in which an inlet for a certain processing liquid is provided and an outlet is provided on the upper end side of the cylindrical portion (see, for example, Patent Document 1). ). A conceptual diagram of this classifier is shown in FIG. 2, and as shown in FIG. 2, the processing liquid is kept flowing in one direction (upward) at a constant flow rate in the classifier, thereby forming a layer for each particle diameter in the cylindrical portion. After forming the structure, it is a method of extracting each particle size layer by slightly increasing the flow rate of the treatment liquid.

Regarding solid-liquid separation technology, there is a sedimentation separation apparatus called thickener as an apparatus used for the production of suspended solids concentrated and purified water. A conceptual diagram of this apparatus is shown in FIG. 3. In this apparatus, the larger the natural sedimentation speed of particles, the more settled toward the near side with respect to the flow direction of the dispersion. A connecting flow path having at least two flow paths, an introduction flow path for guiding the dispersion to the separation section and a discharge flow path for returning the dispersion liquid into the dispersion holding section; a separation section; and a discharge flow There is disclosed a sedimentation separation device having a structure in which a separation portion has a portion having a larger cross-sectional area than a connection portion with a connection channel (for example, refer to Patent Document 2). This separation device does not require complicated operation, power of pumps, etc. and large equipment costs, can be easily installed in an existing reaction tank, etc., and is efficient without being limited by the discharge amount of the dispersion medium. This is a very useful technique in the field of handling solid-liquid mixtures.

Japanese Patent No. 33822752 (Japanese Patent Laid-Open No. 8-332407) JP 2005-205396 A

As described above, a wet classifier as shown in FIG. 2 has been developed as a conventional particle classification method. However, with such a classifying device, the particle concentration becomes infinitely high, so it is difficult to classify with high accuracy. That is, when extracting particles in each layer when the particle concentration becomes high to some extent, it is necessary to extract particles without disturbing the liquid flow rate and flow direction of the classification layer, but this extraction operation is very difficult and the accuracy is high. A lot of skill is required to perform the extraction operation well. As for the solid-liquid separation technique, there is a thickener (sedimentation separation device) as shown in FIG. 3, but since a large sedimentation tank and a large site are required, classification with high accuracy cannot be performed easily. Although the separation apparatus disclosed in Patent Document 2 is extremely useful in the field of handling a solid-liquid mixture as described above, it is particularly suitable for particle classification among solid-liquid separation operations. There was room for ingenuity.

The present invention has been made in view of the above-mentioned present situation, and it is possible to classify particles efficiently and easily with high accuracy while minimizing stress on the particles without requiring complicated equipment and complicated maintenance management. It is an object of the present invention to provide a particle classification device, a classification system using the device, and a particle classification method.

The inventors of the present invention have studied various types of particle classifiers, and in the particle sedimentation type apparatus having the connecting channel, the classifying unit, and the discharging channel to the dispersion holding unit in this order from the bottom side, the connecting channel is provided. When the dispersion liquid inflow channel for guiding the dispersion liquid to the classification part and the dispersion liquid outflow path for the dispersion liquid to return to the dispersion liquid holding part are formed, it is caused by the particle concentration difference of the dispersion liquid. First, attention was paid to the fact that a circulating flow is generated, and that the dispersion medium can be efficiently and easily discharged from the solid-liquid mixture in the dispersion holding section without requiring a complicated operation. In such an apparatus, the classifying unit is composed of a cone part and a straight body part, and is located outside and above the dispersion liquid holding part. If it is set to be generated in the part, almost all of the particles in the dispersion holding part can be subjected to the classification operation without requiring complicated operation, and the particle concentration in the cone part and the straight body part can be increased. It was found that classification can be performed with very high accuracy. In addition, it has been found that the use of such a device can minimize the stress on the particles, and thus can be suitably applied to classification of particles having poor mechanical strength such as microcapsules, hollow particles, and aggregated particles. I came up with the idea that the problem could be solved wonderfully. Further, the present inventors have found that a classification system and a classification method using such a particle classification device are useful for various processes in the chemical industry, and have reached the present invention.

That is, the present invention is an apparatus for classifying particles from a dispersion in a dispersion holding section, and the particle classification apparatus includes a connection flow path, a cone section, a straight body section, and a discharge flow path to the dispersion holding section. The particles are continuously classified in this order from the bottom side, and the particles are classified by generating a circulating flow in the straight body part from the connection flow path to the discharge flow path. A dispersion inflow channel for guiding the dispersion to the cone part and a dispersion outflow channel for returning the dispersion to the dispersion holding part, and part or all of the connection channel is The classifying unit composed of the cone part and the straight body part is immersed from the upper part of the dispersion holding part into the dispersion in the dispersion holding part, and is located outside the dispersion holding part and above the dispersion holding part. This is a particle classifier.

The present invention is also a classification system including the particle classification apparatus.
The present invention is also a particle classification method in which particles are classified from a dispersion using the particle classification apparatus.
The present invention is also a particle obtained by the above particle classification method.
The present invention is described in detail below.

The particle classifier of the present invention is a particle sedimentation type classifier having a connection channel, a cone part, a straight body part, and a discharge channel to the dispersion holding part in this order from the bottom side. In addition, the part comprised from a cone part and a straight body part is called "classification part."
The dispersion holding unit to install the particle classifier is not particularly limited as long as it contains a dispersion containing a dispersion medium and a dispersoid, and the shape thereof is not particularly limited. Any of the holding | maintenance part (for example, reaction tank etc.) of a type | mold may be sufficient. In the dispersion holding section, the dispersoid is preferably dispersed in the dispersion medium, and a stirring device or the like may be installed.
In addition, when installing a stirring apparatus, the stirring power should just be a thing of the grade which prevents sedimentation of the particle | grains in a dispersion liquid holding part, and a dispersion liquid becomes uniform. In other words, it is preferable to perform stirring with a force that does not cause stress on the particles.

As the installation position of the particle classifier in the dispersion holding part, a part or all of the connection flow path is immersed in the dispersion in the dispersion holding part from the upper part of the dispersion holding part, and the classification part holds the dispersion. It is appropriate to set the position so as to be located outside the part and above the dispersion holding part. When the classification part is present outside the dispersion holding part, a sufficient stirring space for preventing particle sedimentation can be secured in the dispersion holding part. Further, for example, in a sealed holding section, it is preferable to insert the connecting flow path from the nozzle or the like above the holding section and immerse it in the dispersion.
In addition, when the liquid surface is disturbed by stirring or the like in the dispersion holding part, there is a possibility that a large amount of bubbles may be mixed in the classification part due to the influence, so the connection flow path is sufficiently immersed in the dispersion. It is preferable.

The connection flow path is composed of a dispersion inflow path for guiding the dispersion to the cone part and a dispersion outflow path for returning the dispersion to the dispersion holding part. In other words, it is appropriate to be composed of at least two flow paths. Thereby, the dispersion liquid in the dispersion liquid holding part circulates, and almost all particles can flow into the classification part at least once and undergo the classification operation, so that the classification accuracy can be improved.

The dispersion inflow channel is a channel that prioritizes guiding the dispersion in the dispersion holding unit to the classification unit. The number of the dispersion liquid inflow channels can be from one to a plurality, and preferably one. Moreover, the connection position to the classification | category part of a dispersion liquid inflow channel will not be specifically limited if it is a cone part.
The dispersion liquid outflow channel is a channel that prioritizes leading the dispersion in the classification unit to the dispersion holding unit. The number of the dispersion outflow channels can be from 1 to a plurality, more preferably 1. In addition, the connection position of the dispersion liquid outflow channel to the classification part is preferably a position where the dispersoid does not accumulate in the classification part, for example, connected to the lowest part of the cone part (the apex part of the cone). It is preferable to do.
In the connection flow path, in order to generate a stable circulating flow in the straight body portion, the ratio (b) of the horizontal cross-sectional area (b) of the dispersion outflow flow path and the horizontal cross-sectional area (a) of the dispersion inflow flow path / A) is preferably set to be 0.2-20. More preferably, it is 0.3-10.
The horizontal cross-sectional area (b) of the dispersion outflow channel does not include the horizontal cross-sectional area (a) of the dispersion inflow channel. For example, as will be described later, in a connection channel having a double pipe structure having a dispersion inflow channel in a dispersion outflow channel, the outer tube including the horizontal cross-sectional area of the inner tube (dispersion inflow channel) The value obtained by subtracting the horizontal cross-sectional area (a) of the dispersion inflow channel from the horizontal cross-sectional area is defined as the horizontal cross-sectional area (b) of the dispersion outflow channel.

The connection channel is also particularly preferably a so-called multi-tube structure having a dispersion inflow channel in the dispersion outflow channel. Thereby, it becomes possible to generate the circulating flow due to the density difference (particle concentration difference) of the dispersion more smoothly in the straight body portion. From the viewpoint of design, it is particularly preferable that the connection flow path is composed of a double pipe having a dispersion inflow path and a dispersion outflow path. FIG. 4 shows a cross-sectional view of an example of a form constituted by the double pipe as viewed from the cone part side. As illustrated in FIG. 4, the connection flow path constituted by the double pipes may be connected to the cone part at the center of the lower part of the cone part, or connected at the end of the lower part of the cone part. You may do. Further, the cross section of the double tube may be circular or rectangular. Among these, from the viewpoint of design, it is preferable to use a double pipe that is connected to the cone part at the center of the lower part of the cone part and has a circular cross section.

In such a multi-tube connection channel, the length of the dispersion inflow channel is preferably equal to or longer than the length of the dispersion outflow channel. That is, at both ends of the dispersion holding unit side and the classification unit side, it is preferable that the length of the dispersion inflow channel is equal to or longer than the length of the dispersion outflow channel. It can be generated stably. More preferably, the ratio (h / H) between the protruding length (h) of the dispersion inflow channel and the cone portion length (H) is set to 0 to 1.0, and more preferably 0 to 0. 0.5. In particular, as shown in FIG. 5, the dispersion liquid outflow channel is positioned at the lowermost part and the central part of the cone part and has a structure that does not protrude from the cone part. It is preferable to have a structure protruding from the connecting portion between the outflow channel and the cone portion.

In the above particle classifier, the classifying unit is composed of a cone part and a straight body part, and is preferably connected to the connection flow path at the low end of the cone part. In addition, although it connects with a straight body part in the upper part of a cone part, specifically, it connects with a straight body part in the part which the internal diameter of the cone part expanded most.
The cone portion is not particularly limited as long as the horizontal cross-sectional area has a shape that gradually expands toward the straight body portion, and examples thereof include a cone shape or a pyramid shape. Further, when the vertical is 0 °, a shape having an inclination angle (θ) of 10 ° to 60 ° is preferable. By setting the tilt angle to 60 ° or less, dispersoids (particles) are prevented from being deposited, and by setting the tilt angle to 10 ° or more, it becomes practical from the viewpoints of design and work. More preferably, the angle is 15 ° to 45 °.
In addition, it is preferable that the cone portion allows the dispersoid to flow quickly inside, and it is preferable that the inner wall surface is smooth.

The straight body portion is connected to an upper portion of a portion where the inner diameter of the cone portion is the largest (portion having the largest horizontal sectional area of the cone portion). The shape of such a straight body portion is not particularly limited, and examples thereof include a cylindrical body whose cross section is a triangle, a square, a rectangle, a polygon or the like.
The horizontal diameter of the straight body part (horizontal diameter when the horizontal cross-sectional area is converted into a circle, c) is the sedimentation rate of the dispersoid (particles), the discharge rate of the dispersion liquid from the discharge channel, the separation flow rate, the safety factor For example, the horizontal diameter (c) of the straight body portion and the total horizontal cross-sectional area of the connecting flow path (the horizontal cross-sectional area a of the dispersion liquid inflow path + the horizontal of the dispersion outflow path) It is preferable to set the ratio (c / (a + b)) to the cross-sectional area b) to be 10 or more.

The length (height) of the straight body portion is preferably set according to the dispersion concentration in order to form a particle concentration gradient in the circulating flow region as will be described later. For example, it is preferable to set the ratio (L / c) of the vertical length (L) in the straight body part and the horizontal diameter (c) of the straight body part to be 1-10. More preferably, it is 1-5.
When the apparatus size is changed, the ratio (L / c) is preferably changed as appropriate in accordance with the change of the ratio (c / (a + b)). For example, when c / (a + b) is constant without being changed, L / c is also not changed, and when c / (a + b) is increased, L / c is also increased, and c / (a + b ) Decreases, it is preferable to decrease L / c.

In the present invention, in order to stably generate the circulating flow in the straight body portion, the ratio (b) of the horizontal cross-sectional area (b) of the dispersion outflow passage and the horizontal cross-sectional area (a) of the dispersion inflow passage (b) / A), the ratio (h / H) of the protruding length (h) of the dispersion inflow channel and the cone portion length (H), and the vertical length (L) of the straight barrel portion and the straight barrel portion It is preferable to determine the size and the like of each part so that the three ratios of the ratio (L / c) to the horizontal diameter (c) all satisfy the respective preferable ranges described above. That is, in the particle classifier of the present invention, b / a, h / H, and L / c are preferably 0.2 to 20, 0 to 1.0, and 1 to 10, respectively. . More preferably, it is 0.3 to 10, 0 to 0.5, and 1 to 5, respectively.

It is also preferable that the straight body portion is not provided with anything that may impede liquid flow, such as an inclined plate or forced stirring mechanism for forcing the particles to settle. If such a forced mechanism is present in the straight body part, there is a possibility that a circulating flow in the straight body part is not sufficiently generated, and there is a possibility that the classification of the particles is not performed smoothly. More preferably, the inside of the straight body is a complete hollow body. In addition, when it does not have a forced mechanism, since it is not necessary to specifically limit the shape of a straight body part, such a form is preferable also from a design viewpoint.

Further, the shape of the upper portion of the straight body portion (the shape of the top plate) is not particularly limited, but a cone shape is particularly preferable. That is, it is preferable to have a structure in which the horizontal cross-sectional area gradually decreases toward the upper part, and the discharge flow path is connected to a portion where the horizontal cross-sectional area is reduced most (the apex portion of the cone). Is preferred.
Thus, by making the upper part of the straight barrel part into a cone shape, it is possible to further prevent a reduction in classification efficiency due to particle retention, it is possible to increase the size of the particle classification device, and the particle diameter to be classified Larger particles can be prevented from entering.

In the particle classification apparatus, the discharge flow channel is a flow channel for discharging the dispersion liquid containing the particles classified by the classification unit. This discharge channel is also suitable as a transfer channel to the next process, and the size, shape, and the like are not particularly limited, and may be determined in consideration of the convenience of the next process.
The connection position of the discharge flow path to the straight body portion may be a position where particles classified in a classification region described later can be discharged. For example, it is preferable to install on the side surface or upper part of the straight body part.
Several examples of connection of the discharge flow path to the straight body portion are shown in FIG. FIG. 6A is a view showing a form in which the upper body shape (top plate shape) of the straight body portion is a vertical plate, and a discharge channel is connected to the center portion thereof, and FIG. It is a figure which shows the form which connected the discharge flow path to the side surface of this, and (c) is the shape where the upper part shape of the straight body part is a cone shape, and connected the discharge flow path to the vertex part of the cone. FIG. In these figures, the flow of the dispersion and the particles are indicated by arrows (black).

In the particle classifier, the dispersion first flows into the classification section through the dispersion inflow channel, and then flows out from the classification section through the discharge channel and the dispersion outflow channel in the connection channel. flowing dispersion flow rate (mm / min) of the _{V in} flowing into the classification zone through the liquid inlet passage, the flow rate of the dispersion flowing out of the discharge flow path (mm / min) _{V Aout,} from a dispersion outflow channel Assuming that the flow rate (mm / min) of the dispersion is V _Bout , these are expressed by the following formula (1);
V _in = V _Aout + V _Bout (1)
Will satisfy the relationship.
In addition, when there are many fine particle fractions (fine particles) in the dispersion liquid flowing into the classification unit, V _Bout decreases and the circulation flow in the straight body increases. On the other hand, when there are few fine particles (fine particles) in the dispersion flowing into the classification part, V _Bout tends to increase, and the circulation flow in the straight body part tends to decrease.

The particle classifier is also preferably in a form having a particle collecting section for collecting particles from the dispersion discharged from the discharge flow path, and a pump connected to the particle collecting section. This makes it possible to collect only the particles classified from the dispersion (classified particles) and transfer the remaining dispersion to the next step.
The particle collecting part is not particularly limited as long as it has a filter opening that can sufficiently collect particles in a particle size range to be classified. In addition, since the shape of the particle collection part may be appropriately selected according to the nature and shape of the particles to be classified, the stress at the time of collecting the particles and the stress at the time of taking out the collected particles are minimized. It is possible to further reduce the stress on the particles.

It is preferable that the particle classifier further has a circulation channel for returning the dispersion liquid from the particle collecting section to the dispersion holding section via the pump. Thereby, since a dispersion medium can be repeatedly guided to a classification part and classification operation can be performed, drainage can be reduced and the amount of dispersion liquid in the system can be kept constant. In addition, a sealed path can be formed, dispersion of the dispersion can be prevented, and control of gas concentration such as oxygen concentration is facilitated.
The pump is not particularly limited as long as the flow rate is stable. For example, a rotary pump such as a gear pump, a vane pump, or a screw pump is preferable. Even a reciprocating pump such as a piston pump, a plunger pump, or a diaphragm pump can be used without any problem if it has little pulsation.

The particle classifier of the present invention also classifies particles by generating a circulating flow in the straight body part from the connection flow path to the discharge flow path.
In the particle classifier, when the dispersion liquid flows from the dispersion liquid holding part into the straight body part through the dispersion inflow channel and the cone part, the straight body part includes a circulation flow region in which the dispersion liquid circulates, and the dispersion liquid. Thus, the particles are divided into two layers, ie, a classification region where particles are classified. The circulation region is the flow of the dispersion liquid that has entered from the dispersion inflow channel gradually spreads through the cone part along the path with the classification area in the straight body part as the apex, and the cone part along the straight body wall surface. Is a region where a circulation flow from the dispersion liquid outflow passage to the dispersion tank is formed, and the classification region is a discharge passage provided from the upper part of the circulation reflux region in the straight body portion to the upper portion of the straight body portion. It is an area that leads to.

In general, when the dispersoid is solid particles, it is known that the sedimentation state is largely divided into three types depending on the particle concentration. In other words, when the particle concentration is very dilute, spontaneous sedimentation occurs in which individual particles settle independently, and in the intermediate concentration region where the particles are thicker, the particles interact with each other. When sedimentation occurs and the concentration range becomes high enough that the particles come into contact with each other, compression sedimentation occurs in which the particle layer undergoes compression. In addition, the sedimentation speed | velocity | rate of particle | grains becomes slow in order of natural sedimentation, interference sedimentation, and compression sedimentation.
As shown in FIG. 7, the sedimentation state of the dispersion is greatly different between natural sedimentation and interference sedimentation. In the interference sedimentation, particles having a small particle diameter and particles having a large particle diameter are simultaneously settled. Therefore, as shown in FIG. 7A, a particle dispersion layer (part indicated by black) and a supernatant liquid (part indicated by white) Are clearly separated. On the other hand, in natural sedimentation, since the sedimentation along the Stokes sedimentation equation (precipitation corresponding to the sedimentation velocity for each particle diameter) is shown, the interface between the particle dispersion layer and the supernatant liquid is shown in FIG. It becomes unclear.

In the straight body portion, the particle concentration gradually decreases from the bottom of the cone portion to the classification region of the straight body portion, and the particle concentration in the classification region is a natural sedimentation region (region having a particle velocity that matches the Stokes sedimentation velocity). ) Particle concentration. As a result, the particle diameter (cut point) classified in the classification region becomes one point, and the classified particles are discharged from the discharge channel. In addition, interference sedimentation occurs in the circulation flow region, and a particle concentration distribution (particle concentration gradient) is formed in the interference sedimentation concentration region (circulation flow region). These states are conceptually shown. 8A and 8B. FIG. 8B shows a state in which the inside of the straight body portion is divided into a circulation flow region (interference sedimentation region) 15 and a classification region (natural sedimentation region) 14, and the discharge flow path 8 is in contact with the classification region 14.

The reason why the particle concentration distribution is formed in the interference sedimentation region (circulation flow region) is considered to be due to the difference between sedimentation in a stationary medium and sedimentation in a fluid medium.
If the ascending flow rate of the dispersion in the classification region is a rate that matches the sedimentation rate of the particles (natural sedimentation rate), the interference sedimentation rate is slower than the natural sedimentation rate, so the ascending flow rate of the dispersion in the circulating flow region is classified. It is estimated that the dispersion flow rate is higher than the rising speed of the dispersion in the region. Therefore, theoretically, it is thought that there is almost no sedimentation phenomenon of particles in the circulating flow region, but it is assumed that sedimentation in a fluidized medium exhibits a sedimentation phenomenon different from sedimentation in a stationary medium as follows. Therefore, it is considered that a particle concentration gradient is formed in the circulating flow region, and a sedimentation phenomenon of particles according to the particle diameter occurs.
As shown in FIG. 9A, in a stationary medium, it is considered that the sedimentation speed (the sedimentation direction is the arrow direction) is the same regardless of the particle diameter due to the interference between the particles. On the other hand, as shown in FIG. 9B, in the fluid medium, there is interference between the particles, but since the liquid flow force 13 is applied and the movement of the individual particles is not synchronized, the interparticle interference force is weakened and the flow vector is reduced. And the settling vector together, it is thought that the settling velocity according to the particle size may be generated.

For this reason, it is considered that a particle concentration gradient is generated in the circulating flow region, and it is understood that the classification requires the formation of an upward flow that matches the natural sedimentation rate of the particles.
The classified particle diameter (cut point) can be freely set by appropriately changing the ascending flow rate in the classification region (that is, the discharge speed from the discharge flow path) according to the natural sedimentation speed of the particles. From the viewpoint of productivity and the like, it is preferable to sequentially set the classified particle diameter (cut point) from the lower particle concentration in the discharged liquid, that is, from the fine particle side. It is also possible to set the classified particle diameter (cut point) from the coarse particle side.

Here, the particle size distribution of particles when classification particle size is set from the fine particle side will be described with reference to FIG.
FIG. 10 is a diagram conceptually showing the existence ratio for each particle diameter of the particles, but the existence ratio of the unclassified particles (unclassified product) is the sum of C, E, and D. Among these, C is an abundance ratio of fine particles (fine particles, fine particles), and D is an abundance ratio of coarse particles (coarse particles, coarse particles).
The proportion of particles obtained by classifying the unclassified product (C + E + D) from the fine particle side, that is, the particles obtained by cutting the fine product C (fine product) is the sum of D and E.
When this coarse particle side (D + E) is then classified on the coarse particle side, coarse particles (coarse product) D are cut, and (sharp) particles with a narrow particle size distribution ((fine particle cut + coarse particle cut)) ) Will be obtained.

In order to efficiently form a particle concentration gradient in the circulating flow region, it is preferable to use a dispersion having a particle concentration region in which interference sedimentation can be obtained. Specifically, a preferable concentration may be set according to the specific gravity of the particles. For example, it is preferable to use a dispersion having a particle concentration of 5 to 40% by mass with respect to 100% by mass of the dispersion. As a result, a particle concentration gradient is generated in the circulating flow region, and the particles are classified in the classification region. Also, industrially, it is preferable to perform classification with such interference sedimentation concentration in consideration of productivity and environmental aspects (reduction of wastewater). More preferably, it is 10-30 mass%. The particle concentration here means the particle concentration in the dispersion holding section.
In the lower part of the classification part (for example, the lower part of the circulating flow area of the cone part or the straight body part, etc.), the density of the dispersion increases due to the particle concentration being higher than the dispersion in the dispersion holding part, and the specific gravity difference Thus, the particles return to the dispersion holding part through the dispersion outflow channel, so that the particle concentration in the classification part does not increase more than necessary.

The ascending flow velocity V in the classification region of the dispersion is equal to the discharge speed of the dispersion from the discharge flow path, and the natural sedimentation speed U of the particles is expressed by the following Stokes equation (2);

(Wherein, U is, the .d _p representing the natural settling rate of the particles, the .Ro _p representing the diameter of the particles (spherical particles), the .Ro representing the density of the particles, .g representing the density of the dispersion medium Represents the acceleration of gravity, and μ represents the viscosity of the dispersion medium.
In addition, the sedimentation velocity of the particles in the circulating flow region, that is, the interference sedimentation velocity of the particles is, for example, the diameter of the dispersion liquid having the same concentration as that of the dispersion liquid in the dispersion liquid holding portion without being affected by the tube wall such as a graduated cylinder. It can be obtained by a method of measuring the distance (the distance at which the separation interface descends) that settles in a certain time after being placed in a transparent cylindrical tube having In interference sedimentation, the particle dispersion layer and the supernatant layer produce a clear interface, so measurement is easy, but the interference sedimentation speed varies depending on the particle concentration, so it can be adjusted to the concentration of the dispersion in the dispersion holding part. is important.
In the present invention, the range of the sedimentation rate of the particles to be classified is preferably 0.01 to 50 mm / min, and more preferably 0.02 to 35 mm / min.

As described above, the particle classification device of the present invention has a circulation flow region and a classification region formed in the straight body part, a particle concentration gradient is formed in the circulation flow region, and a particle concentration in the classification region. Is characterized by the fact that it is the particle concentration in the natural sedimentation region and that the particle size (cut point) classified in the classification region is one point, thereby minimizing the stress on the particles. It is possible to sufficiently exhibit the function and effect of the present invention that makes it possible to classify particles efficiently, simply, and with high accuracy.

The dispersion used in the particle classifier is not particularly limited, and examples thereof include a solid-liquid mixture in which particles are dispersed in a liquid, and may further include a gas. The particles become dispersoid and the liquid component becomes a dispersion medium.
The dispersoid (particles) may be any dispersoid that has a sedimentation rate in the dispersion under the working conditions, for example, metal particles such as gold, silver, nickel, platinum, and tin; silicone, silica, alumina, zirconia Inorganic oxide particles such as titania; resin particles (acrylic, styrene, epoxy, polyester, polyolefin, fluorine, amino resin, etc.), microcapsules, hollow particles, flat particles, agglomerated particles, flakes It is preferable to use organic particles such as particle-like particles.
The size of the dispersoid, that is, the size of the particles to be classified, is preferably a size that is not easily affected by the disturbance of the fluid. For example, the particle diameter is 1 to 500 (μm). preferable. More preferably, it is 5-300 (micrometer).
The dispersion medium is not particularly limited as long as it is lower than the density of the dispersoid and is a liquid that precipitates the dispersoid under the working conditions.

In the particle classification apparatus of the present invention, even particles having poor mechanical strength such as microcapsules, hollow particles, and aggregated particles can be classified without destroying the particles. In the particle classifying apparatus of the present invention, the effect of the present invention can be more fully exhibited especially when particles having a particle strength (particle compressive strength) of 10 MPa or less are classified. In general, particles with a particle compression strength of 10 MPa or less are soft and inferior in mechanical strength. Therefore, with conventional classification methods and classification devices, stress on the particles (friction due to mesh, collision due to pumping, centrifugal force, etc.) No. 2 used in the examples described later, or problems such as the destruction of particles due to friction with the apparatus wall surface, etc. The capsule 1 or the like has a large degree of deformation, and there arises a problem that particles having a diameter larger than the opening diameter of the mesh easily pass through, and classification cannot be performed suitably. However, in the classification device of the present invention, even if the particle compressive strength is 10 MPa or less, the particle is hardly stressed and the deformation of the particle is not related, so that it is possible to perform good classification. . In the present invention, it is more preferable to classify particles having a particle compressive strength of 9 MPa or less, and more preferably to classify particles of 8 MPa or less.

The said particle compressive strength can be calculated | required with the following measuring method, for example.
<Measurement of particle strength>
A drop of the particles diluted with water is dropped on the preparation and dried at 50 ° C. for 5 minutes. This measurement sample is set in a micro-compression tester (product name: MCT-W500, manufactured by Shimadzu Corporation), one independent particle is selected on the slide, the compressive strength is measured, and the obtained measured value is the particle strength. (Particle compressive strength). The measurement conditions are as follows: test force: 9.8 mN, load speed: 0.446 mN / sec, holding time: 0 sec, and indenter diameter: 100 μm.

In the separation apparatus, the operating pressure and temperature are not particularly limited. For example, the pressure can be widely applied from reduced pressure to high pressure, and the temperature can be applied widely from low temperature to high temperature. In addition, if the operating temperature has a temperature difference from the external temperature, such as high temperature, heat convection may occur in the classification section and the classification efficiency may not be sufficient, so in this case, heat insulation measures such as heat insulation materials and steam traces It is preferable to improve the classification efficiency.

In the present invention, as a classification system provided with the particle classification device, a system using a classification method, a manufacturing method, a purification method, or the like having a step of classifying particles continuously or intermittently from the dispersion in the dispersion holding unit. For example, it is useful for a process that requires classification in an industrial production process or the like. Thus, a classification system including the particle classification apparatus of the present invention is also one aspect of the present invention. In addition, a particle classification method for classifying particles from a dispersion using the particle classification apparatus is also one aspect of the present invention. Furthermore, the particles obtained by this particle classification method are also one aspect of the present invention.

Next, the operation method in the preferable form of the particle classification apparatus of this invention and the internal state in the particle classification apparatus in that case are demonstrated using FIG.1, FIG.8-1 and FIG.8-2. In addition, this invention is not limited only to the form of these figures.
1 and 8-1, a double pipe is used as the connection flow path (3 and 4), and the particle collection unit 9, the pump 10 and the circulation flow path 11 are continuously connected to the discharge flow path 8. It is a schematic diagram of the particle classifier which has.
First, a dispersion medium is charged into the dispersion liquid holding unit 1 and the pump 10 is operated to start classification operation in a state where the system is filled with the dispersion medium. After the dispersion liquid holding unit 1 is filled with the dispersion medium, the operation of the pump 10 is once stopped, and the dispersion liquid (particles) or the dispersion liquid containing the same is put into the dispersion liquid holding part 1, and a predetermined liquid as necessary. Further, a dispersion liquid or a dispersion medium is added so as to obtain a particle concentration. Thereafter, the mixture is uniformly adjusted with the agitator 2 as necessary. Furthermore, the pump 10 is restarted while continuing the stirring in the dispersion liquid holding unit 1 as necessary, and the rising speed V of the dispersion liquid in the straight body section 6 (= the discharge speed of the dispersion liquid from the discharge flow path 8). ) Is adjusted to a predetermined speed that is appropriately set based on the Stokes sedimentation speed of the classified particles.
During the operation, it is preferable to add a dispersion medium in the dispersion liquid holding unit 1 so that a part of the connection channel (3 and 4) is immersed in the dispersion liquid.

During the operation, the particles 12 move along the dispersion outflow passage 4 as shown in FIG. 8A in the straight body 6, in which rough classification is performed, and small particles rise. A particle concentration gradient is formed. Then, the circulating flow region 15 and the classification region 14 are formed with time, and classification is started.
Sampling the particles discharged from the discharge flow path 8 to check whether a predetermined classification is performed. If a deviation of the classified particle diameter is confirmed, the discharge flow rate is adjusted and the appropriate classified particle diameter (cut point) ).

The particle classification apparatus of the present invention has the above-described configuration, and efficiently and easily performs the particle classification with high accuracy while minimizing the stress on the particles without requiring complicated apparatuses and complicated maintenance management. Can be suitably classified even for particles with inferior mechanical strength such as microcapsules, hollow particles, and agglomerated particles, and is extremely useful for classifying various particles. It is. In addition, a classification system and a classification method using such a particle classifier can be suitably used for biological reaction processes in addition to processes in various chemical industries.

It is a conceptual diagram which shows an example of the preferable form of the continuous reaction apparatus using the suitable particle classification apparatus of this invention. It is a conceptual diagram of the wet classifier using the sedimentation by the weight of patent document 1. It is a conceptual diagram which shows the sedimentation separator called a thickener. In the suitable particle classification apparatus of this invention, it is sectional drawing which looked at the connection flow path comprised with a double pipe from the cone part side. It is the conceptual diagram which illustrated the form which used the double pipe | tube as a connection flow path in the suitable particle classification apparatus of this invention. In the suitable particle classification apparatus of this invention, it is the conceptual diagram which illustrated the connection position to the straight body part of a discharge flow path. It is a conceptual diagram which shows the difference of the sedimentation state of natural sedimentation and interference sedimentation. It is a conceptual diagram which shows an example of the form which performs classification operation using the suitable particle classification apparatus of this invention. It is the figure which expanded the predetermined part of FIGS. It is a conceptual diagram which shows the difference in the motion of the particle | grains in a stationary medium and a fluid medium. It is the figure which showed notionally the existence ratio for every particle diameter of particle | grains.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.
In the following examples and comparative examples, the classification device No. 1-No. As 9, one having the structure shown in FIG. 1 was used. Classifier No. The following is a reference for the device specifications of 1. Classifier No. 2-No. 9 is a classification device No. 9; 1 except that b / a, h / H, and L / c were set to the values shown in Table 1. The same specifications as in No. 1 were used.
The classification device No. 10 is a structure in which the connecting flow path is a single tube (that is, the structure having only the dispersion liquid outflow path 4 without the dispersion liquid inflow path 3 in FIG. 1. Therefore, b / a and h / H Classifier No. except that L / c is set to the value shown in Table 1. The same specifications as in No. 1 were used.
Moreover, in Comparative Examples 9-13-2, classification operation was performed by the conventional wet classification method as a general classification method. Specifically, after a slurry having a predetermined concentration is prepared using a stirrer 2 in a container equipped with a slurry extraction nozzle at the lower part of the dispersion holding unit 1 and mixed uniformly, a standard sieve (for testing) is used from the nozzle. The slurry was put on a sieve standard, JIS Z8801-1: 2000), and classification was performed with a hand sieve. The opening (μm) of this standard sieve is as shown in Table 4-2.

<Classifier No. 1>
Capacity of dispersion holding unit 1: 10L
Stirrer 2: HEIDON three-one motor connection channel 3 with paddle blades 3 and 4: horizontal cross-sectional area a = 0.785 cm ² of dispersion inflow channel 3, horizontal cross-sectional area b = 1.413 cm of dispersion outflow channel 4 ² , (b / a = 1.8)
Cone 5: Height H = 7 cm, protrusion length h = 1.4 cm of the dispersion inflow channel 3 (h / H = 0.2)
Straight body part 6: straight warp c = 9.28 cm, height L = 13 cm (L / c = 1.4)
Classification part 7: cone part 5 + straight body part 6
Discharge flow path 8: PTFE tube classification particle collecting part 9 with an inner diameter of 10 mm 9: Advantech filter (nominal 1 μm)
Pump 10: Variable flow rate fixed-volume liquid feed pump (manufactured by MASTER FLEX)
Circulation channel 11: PTFE tube having an inner diameter of 10 mm

In Examples and Comparative Examples, particles (No. 1 to No. 4) having the forms shown in Table 2 were used. Further, Example 1-2, Example 2-2, Example 2-3, Example 3-2, Example 4-2, Comparative Example 8-2, Comparative Example 8-3, Comparative Example 11-2, In Comparative Example 12-2 and Comparative Example 13-2, Example 1-1, Example 2-1, Example 2-2, Example 3-1, and Example 4-1 were used as particles for classification, respectively. Coarse particles (coarse particles) obtained after classification in Comparative Example 8-1, Comparative Example 8-2, Comparative Example 11-1, Comparative Example 12-1, and Comparative Example 13-1 were used.

In Table 2, the particle compressive strength (MPa) was measured based on the particle strength measurement test described above.
Among the particles listed in Table 2, No. 1 and no. The particles No. 4 are particles having a large degree of deformation. For example, even when mesh classification is performed, particles larger than the pore diameter of the mesh are easily slipped through, so that classification accuracy cannot be obtained. No. 2 and no. Since the particles of 3 hardly deform, classification is possible if clogging and efficiency in mesh classification are ignored.
In addition, since the mechanical strength of particles with low compressive strength is not sufficient, there is a possibility that the particles may be broken due to centrifugal force, contact with a scraper, stress due to pumping, etc., and good classified particles cannot be obtained. is there. Particles having a particle compressive strength of 10 MPa or less are particularly effective in the classification device of the present invention.

In Examples and Comparative Examples, using the above classification device and particles, classification operation was performed as follows, and particle analysis was performed.
<Classification operation>
The dispersion holding unit 1 was charged with deionized water, and the pump 10 was operated to fill the system with deionized water. Once the operation of the pump 10 is stopped, a water-containing slurry having a particle concentration of 80% by mass is added to the dispersion holding unit 1, and water-containing slurry and deionized water are added so as to obtain a predetermined particle concentration. Adjusted to mix. Further, the pump 10 is restarted while stirring in the dispersion holding unit 1 at normal temperature and normal pressure, and the rising speed V of the dispersion in the straight body 6 (= dispersion of the dispersion from the discharge passage 8). The pump flow rate was adjusted so that the discharge speed was a predetermined speed. The end point of the classification was the time when the concentration of particles discharged to the discharge flow path 8 became extremely thin, or the time when discharged particles disappeared.

<Particle analysis>
The particle size distribution and average particle size of the feedstock particles, the sampling particles in the middle of classification, and the obtained classified particles were measured using a precision particle size distribution measuring device Coulter Multisizer 3 manufactured by Beckman Coulter.
In addition, the particle recovery rate in the target particle size range (unit: mass%) from the ratio of [(particle amount of target particle size in the obtained classified particles) / (particle amount of target particle size in the feedstock particles)]. Asked. In addition, (particle amount of the target particle diameter in the obtained classified particles) is a value determined from (particle mass before classification (A)) × (ratio of target particle range determined by particle size distribution measurement). ,
(Particle size of the target particle size in the feedstock particles) is a value determined from (particle weight after classification (B)) × (ratio of target particle range determined by particle size distribution measurement).
Furthermore, the presence or absence of deformation and breakage of the classified particles was confirmed using a digital optical microscope microscope manufactured by Keyence Corporation.

Examples 1-1 to 4-2
Experiments were conducted by combining the classifier shown in Table 3 and the particles shown in Table 3 with the configuration of the classifier shown in FIG. A series of conditions and results are shown in Table 3.
In all the examples, immediately after the start of the classification operation, it is confirmed that the dispersion liquid flows into the straight body part 6 from both the dispersion liquid holding part 1 through both the dispersion liquid inflow path 3 and the dispersion liquid outflow path 4. It was. Thereafter, the dispersion gradually rises up the straight body portion 6, and a layer of classified particles (classification region) is formed in the vicinity of the connection portion with the discharge flow path 8, and a layer mainly composed of convection of particles below ( The formation of the circulation region) was confirmed. Further, at this time, it was confirmed that the dispersion liquid returned to the dispersion liquid holding unit 1 through the dispersion liquid outflow passage 4, and the circulation flow was stably generated visually in the straight body portion 6.

Comparative Examples 1 to 13-2
Experiments were performed by combining the classifiers shown in Tables 4-1 and 4-2 and the particles shown in Tables 4-1 and 4-2. A series of conditions and results are shown in Tables 4-1 and 4-2.

Comparative Example 1
In the middle of classification, particles were deposited on the cone part 5 and the supply of the dispersion became unstable, and good classification could not be performed. At this time, the circulating flow was not stably generated (visual confirmation).

Comparative Example 2
During the classification, particles were deposited on the cone 5 and the operation became unstable. At this time, the circulating flow was not stably generated (visual confirmation).
As a result, particles having a particle size of 31 μm or less were as high as 15%, and classification was not possible. In addition, the recovery rate was as low as 61%.

Comparative Example 3
Although the classification operation could be continued for a longer time than in Comparative Example 1, eventually the particles were deposited on the cone part 5 and the supply of the dispersion became unstable, and good classification could not be performed. At this time, the circulating flow was not stably generated (visual confirmation).

Comparative Example 4
The dispersion liquid inflow channel 3 is long and reaches the inside of the straight body 6, and the dispersion flow supplied from the dispersion liquid inflow channel 3 disturbs the flow in the circulation region and the classification region of the straight body 6, and is sufficiently A classifying effect could not be obtained. At this time, the circulating flow was not stably generated (visual confirmation).
The particles flowing out from the discharge channel 8 contained particles of 31 μm or more, and the recovery rate was as low as 57%.

Comparative Example 5
Although the classification operation could be continued for a longer time than in Comparative Example 1, eventually the particles were deposited on the cone part 5 and the supply of the dispersion became unstable, and good classification could not be performed. At this time, the circulating flow was not stably generated (visual confirmation).
Since the dispersion liquid inflow channel 3 is short and does not reach the cone portion 5, the classification device No. This is considered to be because the single tube supply state similar to that in FIG.

Comparative Example 6
The straight body portion 6 was short, and the entire straight body portion 6 became a circulation region, and classification region formation was not recognized. At this time, the circulating flow was not stably generated (visual confirmation).
For this reason, 8% of particles having a size of 5 μm or less were contained, and almost no classification was possible. Moreover, the yield was as low as 51%.

Comparative Example 7
Since the straight body portion 6 is extremely long, the dispersion rising speed and the sedimentation speed of the classification setting particles are not balanced, and good classification conditions cannot be obtained. At this time, the circulating flow was not stably generated (visual confirmation).
For this reason, the particle size of 5 μm or less was a relatively low value of 5%, but the recovery rate was as low as 66%.

Comparative Examples 8-1 to 8-3
Classification device No. 1 of Comparative Example 1 The ten discharge channels 8 were changed to a variable type that can be inserted from the upper part of the straight body 6. In addition, four classified particle collecting portions 9 were installed in parallel, and a pulp was installed at a branch portion of each discharge channel 8.
The classification is started under the same conditions as in Comparative Example 1, and when the particles stay in a strip shape in the upper part of the straight body part 6, the tube of the discharge channel 8 is inserted from the upper part of the straight body part 6, and each particle The valve was switched for each layer, and particles were collected in the particle collecting unit 9. At this time, the circulating flow was not stably generated (visual confirmation).
As a result, classified particles having an average particle diameter of 5.8 μm, 6.5 μm, and 9.2 μm were obtained, but the yield was very low and the same operation was performed several times. %. This recovery rate cannot be used as a mass production type classification device.

Comparative Example 9
Particle No. 1 was adjusted with deionized water to a particle concentration of 20% by mass and uniformly dispersed. Using a standard sieve having a mesh size of 32 μm, the fine particle side cut of this dispersion was classified. Immediately, particles were deposited on the sieve, and good classification was not possible.

Comparative Example 10
The procedure was the same as in Comparative Example 9 except that a 45 μm standard sieve was used. However, the particles immediately deposited on the sieve and could not be classified well.

Comparative Example 11-1
Particle No. 1 was adjusted to a particle concentration of 2% by mass with deionized water and uniformly dispersed, and the fine particle side cut of this dispersion was classified using a standard sieve having an opening of 32 μm.
When the particle size distribution of the particles remaining on the sieve was measured, many particles having a particle size of 32 μm or less remained in one operation. Therefore, the particles on the sieve were adjusted again to the same concentration, uniformly dispersed, and classified.
Although the operation was repeated twice, 6% of the particles having a particle size of 32 μm or less remained. Moreover, when the particle diameter of the particle | grains which passed the sieve was measured, many particles of 32 micrometers or more were contained. This is presumably because the microcapsule particles having a hollow interior easily deformed and passed through a 32 μm mesh.
Further, the classified particles were observed with a microscope, and broken microcapsule particles were observed.

Comparative Example 11-2
The particles on the sieve classified in Comparative Example 11-1 were adjusted to a particle concentration of 2% by mass with deionized water and dispersed uniformly, and then the fine particle side cut of this dispersion was performed using a standard sieve having an opening of 45 μm. The classification operation was performed.
As in Comparative Example 11-1, when the particles remaining on the sieve were redispersed and classified twice, a very small amount of particles remained on the sieve. As a result of measuring the particle size distribution of the particles that passed through the sieve, the particle size distribution was almost the same as that before classification, and 23% of particles having a size of 45 μm or more were present.
As a result of observing the classified particles with a microscope, many broken microcapsule particles were observed.

Comparative Example 12-1
Use particles No. 4 and the same operation as Comparative Example 11-1 was performed except that a mesh sieve having an opening of 25 μm was used, and the fine particle side cut classification operation was performed. The classification operation was performed twice in the same manner as in Comparative Example 11-1, but 4.9% of the particles having a particle size of 25 μm or less remained. This is probably because the particles were easily deformed and passed through a 25 μm mesh sieve. Further, the classified particles were observed with a microscope. As a result, partially missing particles and deformed particles were observed.

Comparative Example 12-2
Except using the particle | grains on the sieve of Comparative Example 12-1, and using a 38 micromesh sieve, the same operation as Comparative Example 11-2 was performed, and the coarse particle side cut classification operation was performed. Similar to Comparative Example 11-2, classification was performed twice, but a small amount of particles remained on the sieve. As a result of measuring the particle size distribution of the particles that passed through the sieve, there was no significant change from the particle size distribution before classification. 18% of the particles were present above 38 μm. When the classified particles were observed with a microscope, partially broken particles and deformed particles were observed.

Comparative Example 13-1
Use particles No. 3 except that a mesh sieve with an opening of 50 μm was used and the particle concentration was 10% by mass, the same operation as in Comparative Example 11-1 was performed, and the fine particle side cut was performed. . Unlike Comparative Example 11-1, the classification operation was performed once. The amount of particles of 50 μm or less was 1%, and relatively good classification was possible. However, since clogging on the sieve occurred, classification took time and the classification efficiency was poor. When the classified particles were observed with a microscope, no breakage or deformation of the particles was observed.

Comparative Example 13-2
Except for using the particles on the sieve of Comparative Example 13-1, using a 300 μmesh sieve, and setting the particle concentration to 10% by mass, the same operation as in Comparative Example 11-2 was performed, and the coarse particle side Cut classification was performed. Unlike Comparative Example 11-2, the classification operation was performed once. A large amount of particles remained on the sieve. As a result of measuring the particle size distribution of the particles that passed through the sieve, classification was performed, and the particles were hardly present at 2% above 300 μm. As a result of confirming the particles on the sieve with a microscope, there were many particles of 300 μm or less. As a result of observing the particles passing through the sieve and the particles remaining on the sieve with a microscope, no breakage or deformation of the particles was observed. Similar to Comparative Example 13-1, classification takes time and is inefficient.

From Table 3, Table 4-1, and Table 4-2, the following can be understood.
Classification device No. used in Examples 1-1 to 4-2. 1 to 3, from Table 1, the ratio (b / a) of the horizontal cross-sectional area (b) of the dispersion outflow channel to the horizontal cross-sectional area (a) of the dispersion inflow channel, the dispersion inflow The ratio (h / H) of the projecting length (h) of the road to the cone part length (H), and the ratio of the vertical length (L) in the straight body part to the horizontal diameter (c) of the straight body part (L / c) is within the above-described preferred ranges (that is, 0.2 to 20, 0 to 1.0, and 1 to 10, respectively). On the other hand, the classification device No. used in Comparative Examples 2 to 7 was used. Nos. 4 to 9 are shown in Table 1. In 4-5, b / a is no. In 6 to 7, h / H is No. In Nos. 8 to 9, the classifier No. only when L / c does not satisfy this preferred range. 1 to 3.
Comparing the results of the classification operation under such a difference, in Examples 1-1 to 3-2, a circulating flow is stably generated in the straight body portion, and the particle classification can be performed efficiently with high accuracy. In contrast to Comparative Examples 2 to 7, the circulation flow did not occur stably, and classification could not be continued or classification could be continued, but the recovery rate was remarkably low. It was. From this result, in order to classify particles with a high recovery rate and high efficiency, it is necessary to stably generate a circulating flow in the straight body, and for this purpose, b / a, h / H and L / It can be seen that c is preferably in the range of 0.2 to 20, 0 to 1.0 and 1 to 10, respectively.

Classification device No. used in Comparative Example 1 10 is different from the classifying apparatus of the present invention in that the connection flow path is composed of a single pipe, but in this case also, no circulating flow was generated and classification could not be performed. In Comparative Examples 8-1 to 8-3, the classification device No. It is an example using a device in which the discharge channel and the particle collecting part of 10 are changed, and during operation, the particles stayed in a strip shape in the straight body part, but the recovery rate of the particles is very low, It is not at a level that can be industrially implemented. Therefore, it can be seen that a good classification operation can be realized by configuring the connection channel with at least two of the dispersion inflow channel and the dispersion outflow channel.

Comparative Examples 9 to 13-2 are examples in which classification operation was performed by a conventional wet classification method, but the classification operation could not be performed continuously, and in Comparative Examples 11-1 and 11-2 The microcapsules were deformed and broken. On the other hand, in Examples 1-1 and 1-2 using the same particles, deformation and breakage were not confirmed. In Comparative Examples 12-1 and 12-2, deformation and breakage were observed in the particles, whereas in Examples 4-1 and 4-2 using the same particles, deformation and breakage were not confirmed. . Moreover, in Comparative Examples 13-1 and 13-2, time was required for classification, and the classification efficiency was extremely low. Therefore, it can be seen that by using the classification device of the present invention, the stress on the particles can be minimized, and even particles having poor mechanical strength can be classified efficiently, simply, and with high accuracy.

1: Dispersion holding part 2: Stirrer 3: Dispersion inflow channel 4: Dispersion outflow channel 5: Conical part 6: Straight body part 7: Classification part (cone part 5 and straight body part 6)
8: Discharge flow path 9: Particle collection unit 10: Pump 11: Circulation flow path 12: Particle (dispersoid)
13: Force of liquid flow of dispersion 14: Natural sedimentation region (classification region)
15: Interference sedimentation region (circulation flow region)
16: Dispersion flow direction a: Horizontal cross-sectional area b of dispersion inflow channel 3 Horizontal cross-sectional area of dispersion outflow channel 4 (provided that b does not include a)
c: Horizontal diameter h of the straight body part 6: Protruding length H of the dispersion inflow channel 3: Vertical length L of the cone part 5: Vertical length V of the straight body part 6: Dispersion liquid in the straight body part 6 Rising rate C (FIG. 10): Presence ratio E of fine particles (FIG. 10): Presence ratio of fine and coarse cut products D (FIG. 10): Presence ratio of coarse particles Arrow (black): Flow of particles or dispersion direction

Claims (6)

An apparatus for classifying particles from the dispersion in the dispersion holding section,
The particle classifier has a connection channel to the dispersion holding part, a cone part, a straight body part, and a discharge channel continuously from the bottom side in this order, and the dispersion liquid flows from the connection channel to the discharge channel. By classifying the particles by generating a circulating flow in the straight body part,
The connection channel includes a dispersion inflow channel for guiding the dispersion to the cone portion and a dispersion outflow channel for returning the dispersion to the dispersion holding unit. Part or all is immersed in the dispersion in the dispersion holding part from the upper part of the dispersion holding part,
The particle classification device, wherein the classification unit including the cone portion and the straight body unit is located outside the dispersion holding unit and above the dispersion holding unit. 2. The particle classifier further includes a particle collecting unit that collects particles from the dispersion discharged from the discharge channel, and a pump connected to the particle collecting unit. The particle classifier described in 1. The particle classification device according to claim 2, further comprising a circulation channel for returning the dispersion from the particle collection unit to the dispersion holding unit via the pump. A classification system comprising the particle classification device according to claim 1. A particle classification method comprising classifying particles from a dispersion using the particle classifier according to claim 1. A particle obtained by the particle classification method according to claim 5.

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