JP2013059722A - Medium stirring type dispersing machine and method for washing medium stirring type dispersing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medium stirring type dispersing machine in which the deterioration in treatment efficiency is suppressed during dispersing machine operation.SOLUTION: The medium stirring type dispersing machine includes: a dispersion vessel 10 having a liquid inlet 16 for introducing a liquid to be treated and a liquid outlet 20 for discharging the treated liquid after treatment; a stirring means arranged in the dispersion vessel 10; a screen 14 arranged in the dispersion vessel 10, which covers the liquid outlet 20; and a backwashing means for jetting a fluid toward the inner surface of the screen 14 from a rotation nozzle provided in the screen 14 from the side of the liquid outlet 20 during dispersion treatment.

Description

  The present invention relates to a medium agitating disperser and a method for cleaning a medium agitating disperser.

  A medium agitation type disperser (media disperser) is a container (dispersion chamber) equipped with a stirring mechanism that rotates around a rotation axis, a liquid to be treated containing a dispersion medium and dispersoid particles, and a hard and spherical shape. This is a wet type dispersion apparatus that agitates a dispersion medium (media, beads, etc.) and reduces dispersoid particles in the liquid to be treated by collision or shearing of the dispersion medium, and is widely used.

  In order to separate the dispersion medium filled in the stirring mechanism in the container and the treatment liquid from the liquid outlet of such a medium agitation type disperser, a gap smaller than that of the dispersion medium is provided, and the treatment liquid is discharged from the liquid outlet. There are known a gap type that screens and a screen type that includes a screen having a finer opening than the dispersion medium and discharges the processing liquid from the liquid outlet. The screen type has a larger filtration area and generally has a higher processing capacity than the gap type.

  It has been studied to remove the clogging of the screen in such a screen-type medium stirring type disperser. For example, Patent Literature 1 includes an ultrasonic probe on the liquid outlet side of a screen covering the liquid outlet and a pressure sensor on the dispersion chamber side, detects an increase in pressure on the dispersion chamber side, and operates the ultrasonic probe. A method for removing screen clogging is described.

  Further, in Patent Document 2, when a plurality of different substances are dispersed using a medium agitating pulverizer, the cleaning work when switching from one substance to another substance is performed efficiently. In addition, when cleaning is performed after the equipment is stopped and the residual liquid inside is drained, a plurality of cleaning nozzles are provided so as to face the screen covering the liquid outlet, and the cleaning liquid is supplied from the cleaning nozzles to the inside of the dispersion chamber. A method for cleaning the inside of a disperser without spraying the screen and removing the dispersion medium without losing the dispersion medium is described.

JP-A-8-252472 JP 2000-354780 A

  The objective of this invention is providing the washing | cleaning method of the medium stirring type disperser and medium stirring type disperser by which the fall of the processing efficiency during a disperser operation is suppressed.

  The invention according to claim 1 is a dispersion container having a liquid inlet for introducing a treatment liquid containing a dispersion medium and dispersoid particles, and a liquid outlet for discharging a treatment liquid after the treatment liquid is dispersed by the dispersion medium. A stirring means provided inside the dispersion container, a screen provided inside the dispersion container and covering the liquid outlet, and a rotating nozzle provided inside the screen from the liquid outlet side during the dispersion treatment And a backwashing means for jetting fluid toward the inner surface of the screen.

  The invention according to claim 2 is the medium agitating type disperser according to claim 1, wherein the backwashing means jets the treated processing liquid in a reverse flow from the liquid outlet side toward the inner surface of the screen. .

  According to a third aspect of the present invention, there is provided a dispersion container having a liquid inlet for introducing a treatment liquid containing a dispersion medium and dispersoid particles, and a liquid outlet for discharging the treatment liquid after the treatment liquid is dispersed by the dispersion medium. The screen from the liquid outlet side during the dispersion treatment by a medium stirring type disperser having stirring means provided inside the dispersion container and a screen provided inside the dispersion container and covering the liquid outlet This is a cleaning method for a medium agitating type disperser in which a fluid is ejected from a rotary nozzle provided in the interior of the screen toward the inner surface of the screen.

  According to a fourth aspect of the present invention, there is provided the cleaning method for a medium agitating disperser according to the third aspect, wherein the treated liquid is jetted in a reverse flow from the liquid outlet side toward the inner surface of the screen.

  According to the first aspect of the invention, compared to the case where there is no backwashing means for injecting liquid or gas from the rotary nozzle provided in the screen to the inner surface of the screen during the dispersion process. Thus, there is provided a medium stirring type disperser in which a decrease in processing efficiency during operation of the disperser is suppressed.

  According to the second aspect of the present invention, the medium agitation type disperser in which the solid content ratio of the recovered processing liquid is stabilized as compared with the case where the backwashing means does not inject the processing liquid after processing in reverse flow. Is provided.

  According to the invention according to claim 3, during the dispersion process, compared to a case where liquid or gas is not injected from the rotary nozzle provided in the inside of the screen from the liquid outlet side toward the inner surface of the screen, the dispersion machine is in operation. Provided is a method for cleaning a medium agitating disperser that suppresses a decrease in processing efficiency.

  According to the invention which concerns on Claim 4, compared with the case where the processing liquid after a process is made to flow backward and is not injected, the washing | cleaning method of the medium stirring type disperser with which the solid content ratio of the collect | recovered processing liquid is stabilized is provided. .

It is a schematic block diagram which shows an example of the medium stirring type disperser which concerns on embodiment of this invention. It is a schematic block diagram which shows an example of the screen part in the medium stirring type disperser which concerns on embodiment of this invention. It is AA sectional drawing in FIG. It is a schematic block diagram which shows an example of the conventional medium stirring type disperser used by the comparative example.

  Embodiments of the present invention will be described below. This embodiment is an example for carrying out the present invention, and the present invention is not limited to this embodiment.

  A schematic configuration of an example of a medium agitating disperser according to an embodiment of the present invention is shown in FIG. 1, and the configuration will be described. The medium agitating disperser 1 includes a dispersion container having a liquid inlet 16 for introducing a liquid to be treated containing a dispersion medium and dispersoid particles, and a liquid outlet 20 for discharging the treatment liquid after the dispersion of the liquid to be treated by the dispersion medium. 10, a stirring device 12 as a stirring means provided inside the dispersion container 10, and a screen 14 provided inside the dispersion container 10 and covering the liquid outlet 20. In FIG. 2, an example of the part of the screen 14 in the medium stirring type dispersion machine 1 is shown. The medium agitating type disperser 1 is one that communicates with the backwashing fluid inlet 22 inside the screen 14 as backwashing means for jetting fluid from the liquid outlet 20 side toward the inner surface of the screen 14 during dispersion processing. The rotating nozzle 24 having the above-described injection port 28 is provided.

  1, the liquid inlet 16 is provided in the upper part of the dispersion container 10, and the liquid outlet 20 is provided in the lower part of the dispersion container 10 and is covered with the screen 14. In the upper part of the dispersion container 10, a dispersion medium inlet 18 for introducing the dispersion medium is provided. The inside of the dispersion container 10 is a dispersion chamber 26, and the stirring device 12 has a stirring member such as a stirring blade and a stirring shaft, for example, and the stirring blade and the like are centered around the rotation shaft by a driving means such as a motor (not shown). It is rotated. The screen 14 is installed near the center of the lower part of the dispersion container 10 so as to cover the liquid outlet 20. As shown in FIG. 2, a rotary nozzle 24 having one or more injection ports 28 is provided in the vicinity of the center of the inside of the screen 14, and the injection port 28 is a backwash fluid inlet provided at the lower part of the dispersion container 10. The rotary nozzle 24 is rotated around the rotary shaft by a driving means such as a motor (not shown). The backwash fluid inlet 22 is connected to the backwash fluid pipe 34 by connecting means such as a joint 30.

  As shown in the AA sectional view of FIG. 2 in FIG. 3, the injection port 28 of the rotary nozzle 24 is, for example, a cylindrical shape or a slit shape protruding in the tangential direction of the outer peripheral portion of the main body portion of the rotary nozzle 24. It has a structure such as.

  The cleaning method of the medium stirring type disperser and the operation of the medium stirring type disperser 1 according to the present embodiment will be described.

  A dispersion medium such as beads is introduced into the dispersion chamber 26 from the dispersion medium inlet 18. While rotating a stirring member such as a stirring blade of the stirring device 12 by driving means such as a motor (not shown), a liquid to be treated containing a dispersion medium such as water and dispersoid particles such as a pigment is transferred from the liquid inlet 16 to the dispersion chamber 26. Introduced with a pump. The introduced liquid to be treated is dispersed by receiving a frictional force between dispersion media stirred by a stirring blade or the like, and is discharged from the liquid outlet 20 through the screen 14 as a processing liquid. The dispersoid particles contained in the liquid to be treated are pulverized into fine particles by receiving frictional force between the dispersion media. During this time, the liquid to be treated receives a stirring action, and the pulverized dispersoid particles are mixed in the dispersion medium to be in a dispersed state. The screen 14 functions to separate the processing liquid and the dispersion medium at the outlet of the dispersion container 10. In this way, the dispersion process is performed (dispersion process).

  In such a continuous medium agitating type disperser, the screen provided for separating the treated liquid after dispersion and the dispersion medium may become clogged as the operation time elapses. In particular, when the dispersion treatment is continuously performed for a long time, the dispersion medium, fragments thereof, or dispersoid particles in an undispersed state are collected on the screen, and the throughput is reduced by reducing the opening area of the screen. In some cases, a predetermined dispersion condition cannot be maintained. In order to avoid such a situation, the regular disassembly and cleaning is usually performed. However, the discontinuation time of the disperser becomes longer and the processing efficiency may be reduced by performing the periodic disassembly and cleaning. In the medium agitation disperser 1 according to the present embodiment, a reduction in processing efficiency during operation of the disperser is suppressed by providing a mechanism that cleans the screen 14 during continuous operation and removes clogging. As a result, stable continuous operation for a long time is performed, and the frequency of periodic equipment stoppage, disassembly and cleaning, etc. is reduced.

  During the dispersion process, a backwashing fluid such as a liquid is supplied from the backwashing fluid inlet 22 to the rotary nozzle 24 by a pump or the like, and the fluid is jetted from one or more jetting ports 28 toward the inner surface of the screen 14. Backwash. At this time, the rotating nozzle 24 is rotated by driving means such as a motor (not shown). Thereby, the screen 14 is washed during continuous operation, and the clogging of the screen 14 is removed. In this specification, “backwashing during dispersion processing” means not only the case of performing backwashing while performing the dispersion treatment, but also the discontinuation of the disperser by stopping the supply of the liquid to be treated. Including the case of backwashing.

  Further, by using the rotating nozzle 24 that rotates inside the screen 14, it is not necessary to install a plurality of nozzles in the rotating direction, and the clogging of the screen 14 is removed with a relatively small flow rate of fluid.

  The main body of the rotary nozzle 24 is, for example, a cylinder such as a cylinder and is made of metal, resin, or the like. The shape of the ejection port 28 is not particularly limited as long as the fluid is ejected toward the inner surface of the screen 14. The shape of the injection port 28 is not limited to the cylindrical or slit-like structure protruding in the tangential direction of the outer peripheral portion of the main body of the rotary nozzle 24 as in the example of FIG. It may be a circular or slit-shaped opening provided on the surface. By adopting a structure that protrudes with respect to the tangential direction of the outer peripheral portion of the main body of the rotary nozzle 24 as in the example of FIG. The effect is enhanced, and a driving force for rotating the rotary nozzle 24 is also obtained. The number of the injection ports 28 should just be one or more. What is necessary is just to determine suitably the number, arrangement position, shape, injection flow rate, etc. of the injection port 28 so that it can inject as uniformly as possible to the inner surface of the screen 14.

  Examples of the backwash fluid include liquids such as water and organic solvents such as alcohol, gases such as air and inert gas, and the like. When gas is used as the backwashing fluid, bubbles may be mixed into the treatment liquid, or dispersion efficiency may be reduced due to the mixed bubbles, and therefore it is preferable to use a liquid as the backwashing fluid. When using a liquid, it is preferable to use the same dispersion medium as the liquid to be treated. When using gas, you may provide a deaeration means.

  In the present embodiment, it is preferable to use the treated liquid after the treatment as a backwash fluid. By using the treatment liquid for removing clogging, the solid content ratio of the collected treatment liquid is stabilized. In addition, contamination of foreign matter in the collected processing liquid is suppressed. For example, the treated processing liquid is stored in a processing liquid tank or the like, and is backflowed by a pump or the like, and the processing liquid is supplied as a backflow fluid from the backwashing fluid inlet 22 to the rotating nozzle 24, and from the injection port 28 to the screen. What is necessary is just to inject toward 14 inner surfaces.

  The screen 14 has, for example, a cylindrical shape such as a cylinder and is made of metal, resin, ceramic, or the like. What is necessary is just to determine suitably the diameter of the opening part of a screen, etc. according to the objective dispersion | distribution.

  The dispersion medium is not particularly limited as long as it has an effect of pulverizing the dispersoid particles, and examples thereof include beads and media. The material, shape, size, and the like of the dispersion medium may be appropriately determined according to the intended dispersion.

  Examples of the dispersoid particles include pigments, cosmetics, semiconductor abrasives, magnetic recording materials, battery materials, dyes, and the like.

  Examples of the dispersion medium include water and organic solvents such as alcohol.

  Examples of the stirring member include a stirring blade, a rotor, and a disk. The rotor includes a pin rotor shape in which an uneven portion is provided on the outer peripheral portion. The disk also includes a porous disk having a plurality of holes drilled in the main body, and a star disk having irregularities on the outer periphery of the disk.

  The medium stirring type disperser and the method for cleaning the medium stirring type disperser according to the present embodiment include, for example, various materials such as an electrostatic charge image developing toner material, various ink materials, a liquid crystal display material, and a cosmetic material. Used for manufacturing.

  Hereinafter, although an example and a comparative example are given and the present invention is explained more concretely in detail, the present invention is not limited to the following examples.

<Example 1>
(Preparation of black pigment dispersion)
The following materials were weighed into a stainless steel container with a bottom valve, and stirred until the pigment powder was taken into the liquid to prepare a liquid to be treated.
Carbon black (Cabot Corporation, R330) 20 parts by weight Surfactant (Kao Corporation, Emar 0) 2 parts by weight Ion-exchanged water 78 parts by weight

  Subsequently, the dispersion process was performed using the continuous medium stirring type disperser (with a rotating nozzle type backwashing mechanism) shown in FIG. 1 and FIG. The dispersion treatment was performed by a pass method in which the liquid to be treated was continuously sent from the bottom valve to the disperser with a tube pump, and the liquid that passed through the disperser was continuously collected into another container. The flow rate of the liquid to be treated was 1 kg / min. During the dispersion treatment, the stainless steel container containing the liquid to be treated was gently stirred, and cooling water of 15 ° C. was passed through the jacket of the disperser to suppress heat generation as much as possible. In the dispersion chamber, zirconia beads having a diameter of 0.3 mm were introduced as a dispersion medium, and the filling rate with respect to the volume of the dispersion chamber was 80%. The peripheral speed of the stirring blade in the dispersion chamber was set to 12 m / sec. As the screen, a screen having an opening diameter of 50 mm (cylindrical shape having an inner diameter of 44 mm and a height of 60 mm) was used. The backwashing mechanism rotated the rotating nozzle at a rotation speed of 30 rpm, and used 1.0 kg of processing liquid as backwashing fluid for every 20 kg processing. As the rotary nozzle, one in which five injection ports (inner diameter: 3.0 mm) protruding in the tangential direction of the outer peripheral portion of the cylindrical main body portion were arranged at intervals of 10 mm in the axial direction of the main body portion was used.

  As a result of dispersion treatment of 200 kg of the liquid to be treated under the above conditions, there was almost no increase in pressure in the disperser, and stable operation could be completed during 3 hours of operation. Further, when the volume average particle diameter of the pigment was measured by Microtrack UPA manufactured by Nikkiso Co., Ltd., it showed a sufficient dispersibility from 150 nm to 160 nm stably from the initial stage to the final stage of the dispersion, and the solids of the collected processing liquid The fraction was also stable with almost no change from 21.5 mass% to 22.5 mass% from the initial stage to the final stage.

<Example 2>
Dispersion treatment was performed using ion-exchanged water as the backwash fluid and other conditions set to the same conditions as in Example 1.

  As a result of dispersion treatment of 200 kg of the liquid to be treated under the above conditions, there was almost no increase in pressure in the disperser, and stable operation could be completed during 3 hours of operation. Further, the volume average particle diameter of the pigment showed a sufficient dispersibility from 150 nm to 160 nm stably from the beginning to the end of dispersion. However, the solid content ratio of the recovered treatment liquid was slightly unstable at 18.3% by mass or more and 21.4% by mass or less.

<Example 3>
Air was used as the backwash fluid, and the other conditions were set to the same conditions as in Example 1 to perform the dispersion treatment.

  As a result of dispersion treatment of 200 kg of the liquid to be treated under the above conditions, there was almost no increase in pressure in the disperser, and stable operation could be completed during 3 hours of operation. Further, the volume average particle diameter of the pigment shows a sufficient dispersibility of 150 nm to 160 nm stably from the initial stage to the final stage of dispersion, and the solid content ratio of the recovered treatment liquid is 21.6 masses from the initial stage to the final stage. % To 22.4% by mass and stable with almost no change. However, since bubbles were mixed in the processing liquid, there was a problem that bubbles overflowed from the recovered liquid.

<Comparative Example 1>
Dispersion treatment was performed in the same manner as in Example 1 except that the conventional continuous medium stirring type disperser (without backwashing mechanism) shown in FIG. 4 was used. 4 includes a dispersion container 50, a stirring device 52, a screen 54, a liquid inlet 56, a dispersion medium inlet 58, and a liquid outlet 60.

  At the stage where 80 kg of the liquid to be treated was dispersed, an increase in pressure in the disperser was confirmed, and a rapid decrease in the treatment flow rate was confirmed, making it impossible to continue further operation. After that, the disperser was disassembled and washed, and the dispersion process was resumed. However, the same condition occurred even at the stage where 150 kg was dispersed, and the dispersion of 200 kg of the liquid to be treated was completed in the same manner. The volume average particle diameter of the pigment is stable from 150 nm to 160 nm stably from the initial stage to the final stage of dispersion, and the solid content ratio of the recovered treatment liquid is also 21.7% by mass or higher from the initial stage to the final stage. It was stable with almost no change to 22.4% by mass or less. However, the dispersion treatment time of 200 kg of the liquid to be treated exceeded about 8 hours including the decomposition cleaning time as compared with Example 1, and the treatment efficiency was lowered.

<Comparative example 2>
The rotating nozzle was not rotated, and other conditions were set to the same conditions as in Example 1 to perform dispersion processing.

  Under the above conditions, 200 kg of the liquid to be treated was dispersed, and as a result, the treatment time was 6 hours, and a reduction in treatment efficiency was confirmed. The volume average particle diameter of the pigment was stable and sufficient from 150 nm to 160 nm from the beginning to the end of dispersion. The solid content ratio of the recovered treatment liquid was stable with almost no change from 21.5 mass% to 22.6 mass% from the initial stage to the final stage.

  As described above, in Examples 1 to 3, the dispersion is performed as compared with Comparative Examples 1 and 2 by ejecting the fluid from the liquid outlet side toward the inner surface of the screen from the liquid outlet side during the dispersion process. Reduction in processing efficiency during machine operation was suppressed.

  1,3 Medium stirring type disperser, 10,50 Dispersion vessel, 12,52 Stirring device, 14,54 Screen, 16,56 Liquid inlet, 18,58 Dispersing medium inlet, 20,60 Liquid outlet, 22 For backwashing Fluid inlet, 24 rotary nozzle, 26 dispersion chamber, 28 injection port, 30 joint, 34 Backwash fluid piping.

Claims (4)

A dispersion container having a liquid inlet for introducing the liquid to be treated containing the dispersion medium and the dispersoid particles, and a liquid outlet for discharging the treatment liquid after the dispersion of the liquid to be treated by the dispersion medium;
Stirring means provided inside the dispersion vessel;
A screen provided inside the dispersion vessel and covering the liquid outlet;
Backwashing means for injecting fluid from the liquid outlet side to the inner surface of the screen from the liquid outlet side during the dispersion treatment;
A medium stirring type disperser characterized by comprising:   The medium agitation type disperser according to claim 1, wherein the backwashing means reversely injects the treated liquid from the liquid outlet side toward the inner surface of the screen.   A dispersion container having a liquid inlet for introducing a liquid to be treated containing a dispersion medium and dispersoid particles, and a liquid outlet for discharging a treatment liquid after the dispersion of the liquid to be treated by the dispersion medium is provided inside the dispersion container. A rotating nozzle provided in the screen from the liquid outlet side during the dispersion process by the medium stirring type disperser having the stirring means and the screen provided inside the dispersion container and covering the liquid outlet. A cleaning method for a medium agitating type disperser, wherein a fluid is jetted toward an inner surface of the screen.   The method for cleaning a medium agitating disperser according to claim 3, wherein the processing liquid after processing is jetted while flowing backward from the liquid outlet side toward the inner surface of the screen.

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