JP6611183B2 - Bead mill - Google Patents

Description

  The present invention relates to a wet medium stirring mill (bead mill) used to pulverize and disperse a liquid object to be processed from micron to nano-sized fine particles in a wet process.

  Conventionally, from various liquids to pastes in the field of fine chemicals such as various inks, polymerization toners, paints, pigments, photosensitizers, liquid crystal color filters, electronic materials, carbon nanotubes, various plant cells, metal powders, inorganics, organics, etc. For the pulverization and dispersion of the raw material, a wet medium stirring mill (bead mill) using a rotating rotor or the like is used. In general, in a bead mill, a rotor is provided inside a stator, and a grinding chamber serving as a grinding chamber is formed between the rotor and the stator. In the grinding chamber, medium beads such as zirconia beads are supplied together with the liquid raw material. The medium beads supplied into the crushing chamber show a complicated movement with the rotor operation, and when the liquid raw material passes between the flowing medium beads, shearing stress, shearing force, etc. are applied to the raw material particles to be processed, and the raw material is pulverized. , Distributed. The material to be treated, which has been dispersed and finely pulverized, is separated from the medium by a bead separator, and the product in a slurry state is discharged from the product discharge port to the outside of the machine.

JP 2003-225579 A

  However, in such a bead mill, if the medium beads do not stay in the pulverization chamber and flow out, efficient pulverization and dispersion of the raw material cannot be performed. On the other hand, if the medium beads are clogged in a part of the crushing chamber, the raw material crushing process itself is hindered. For this reason, in the bead mill, it is required to retain an appropriate amount of medium beads in the pulverizing chamber without clogging the medium beads in a part of the pulverizing chamber, and an apparatus capable of satisfying such a request in a well-balanced manner has been required. .

  An object of the present invention is to provide a bead mill capable of supplying and retaining an appropriate amount of medium beads in a pulverizing chamber to perform efficient pulverization and dispersion treatment.

Bead mill of the present invention includes a stator having an inner peripheral surface of the cylindrical hole shaped inner space with no unevenness, attached to a rotating shaft, which is rotatably disposed within the interior space of said stator, no irregularities a single rotor cylindrical having an outer peripheral surface, is formed between the inner peripheral surface of the stator formed in a similar shape as the outer peripheral surface of the rotor to each other, the stator side and the inside thereof A crushing chamber having no unevenness on the rotor side, and while rotating the rotor, in the crushing chamber, the liquid processing object and the medium beads as raw materials are mixed and stirred, and the processing object is desired A wet bead mill for pulverizing the fine particles into a raw material supply pipe that opens to one end side in the axial direction of the internal space and supplies the workpiece to the pulverization chamber, and the other axial end of the internal space Provided on the side, A bead separator that separates a physical object and the medium bead, and a product that is disposed downstream of the bead separator and discharges the object to be processed separated from the medium bead to the outside of the stator by the bead separator. has a discharge pipe, the said stator, toward the other end from the one end, and an inner diameter enlarged in diameter, the rotor, the distance between the inner peripheral surface of the stator is substantially the same So that the outer diameter is increased from the one end side toward the other end side, and the rotor further increases the stirring force so that the medium beads are easily collected in the grinding chamber. Each of the axial end surface on the one end side positioned on the raw material supply side and the axial end surface on the other end side positioned on the raw material discharge side has a protruding portion protruding in the axial direction, and the protruding portion Is radially outward from the rotating shaft. Toward the outer side of the radius of the rotor, a plurality of portions are provided along the circumferential direction, and in the internal space, only the axial end surface of the rotor is provided with a protrusion, The stator does not have a protrusion on a surface facing the axial end surface of the rotor.

  In the present invention, by providing protrusions projecting in the axial direction on the end surface on the raw material supply side and the end surface on the raw material discharge side of the rotor, the medium beads are easily collected in the grinding chamber. For this reason, the medium beads remain in the crushing chamber, which is a crushing zone, and an efficient crushing process is possible.

Further, in the bead mill, the protruding portion, the direction from the rotational axis radially outward, more to place the outer position than half the radius of the rotor, without interfering with the rotation of the rotor, grinding Efficiency can be improved effectively.

The protrusion may be a trapezoidal blade protruding from the axial end face of the rotor or a pin attached to the axial end face of the rotor. In this case, both the protrusions disposed on the end surface on the one end side located on the raw material supply side of the rotor and the protrusions disposed on the end surface on the other end side located on the raw material discharge side of the rotor are both. It may be a pin. Further, the protrusion disposed on the end surface on the one end side positioned on the raw material supply side of the rotor is a trapezoidal blade, and is disposed on the end surface on the other end side positioned on the raw material discharge side of the rotor. The protrusion may be a pin.

Further, the inner diameter of the stator is increased from the one end side toward the other end side, and the outer diameter of the rotor is set at the one end side so that the distance from the inner peripheral surface of the stator is substantially the same. From this, the diameter may be increased toward the other end side , which makes it easier for the medium beads to gather in the pulverization chamber and improve the pulverization efficiency.

  According to the present invention, in the wet bead mill that stirs and pulverizes the medium beads and the liquid object to be processed in the pulverization chamber, the end surface on the raw material supply side and the end surface on the raw material discharge side of the rotor face each other in the axial direction. Therefore, the stirring force by the rotor is increased, the medium beads are easily collected in the grinding chamber, and a more efficient grinding process can be performed.

It is explanatory drawing which shows the structure of the bead mill which is one embodiment of this invention. (A) is explanatory drawing which shows the structure of the pin attached to the raw material discharge side of a rotor, (b) is explanatory drawing which shows the structure of the pin attached to the raw material supply side of a rotor. (A) is an end view on the raw material discharge side of the rotor, and (b) is an end view on the raw material supply side of the rotor. (A) is explanatory drawing which shows the structure of a stirring blade, (b) is an end elevation by the side of the raw material supply of a rotor at the time of using a stirring blade.

  Embodiments of the present invention will be described below. FIG. 1 is an explanatory diagram showing a configuration of a bead mill 1 according to an embodiment of the present invention. The bead mill 1 according to the present invention is a wet medium agitation mill. In the bead mill 1, a liquid raw material (liquid object to be treated: raw material slurry) and medium beads are mixed, and the mixture of both slurry is stirred. The liquid raw material in the bead mill is pulverized and dispersed into micron-order and nano-order fine particles by shear stress and shearing force caused by the medium beads. The dispersed and finely pulverized liquid raw material is separated from the medium beads by a bead separator and discharged from the product discharge port to the outside of the apparatus.

  As shown in FIG. 1, the bead mill 1 has a structure in which a rotor 2 is rotatably arranged in a stator composed of a front stator 3 and a rear stator 4. A front plate 5 is disposed on the front portion (left side in FIG. 1) of the front stator 3 so as to cover the opening of the front stator 3. The front plate 5 is fixed to the rear stator 4 by the stud bolt 6 together with the front stator 3.

  The rotor 2 is fixed to a rotating shaft 7 disposed in the center of the stator. A mechanical seal 8 is disposed on the outer periphery of the rotating shaft 7. The rotating shaft 7 extends in the horizontal direction, is rotatably supported by a bearing, and is rotationally driven by a motor (not shown). By supporting the rotating shaft 7 with a bearing, the shaft can be prevented from swinging and the sealing performance of the mechanical seal 8 can be improved. The rotor 2 is hollow, and a shaft end disk 9 is attached to the center of the front portion (left side in FIG. 1). The shaft end disk 9 is fixed to the tip end portion of the rotating shaft 7 with a bolt 11.

  An annular crushing chamber (crushing zone) 12 is formed between the rotor 2 and the front stator 3. The rotor 2 and the front stator 3 are provided concentrically, and the inner peripheral surface of the front stator 3 and the outer peripheral surface of the rotor 2 have a similar shape. In the bead mill 1, the distance between the outer peripheral surface of the rotor 2 and the inner peripheral surface of the front stator 3, that is, the difference between the outer diameter of the rotor 2 and the inner diameter of the front stator 3 is formed substantially the same. The inner peripheral surface of the front stator 3 has a maximum inner diameter at a portion facing the maximum diameter portion 2 a of the rotor 2. A portion of the rotor 2 that faces the inclined portion 2b is formed on an inclined surface. In the bead mill 1, the outer diameters of the rotor 2, the front stator 3, and the crushing chamber 12 are increased from the raw material supply side (right side in FIG. 1) toward the discharge side (same left side).

  On the right end side of the grinding chamber 12 in the figure, a raw material supply path 13 formed in the rear stator 4 is opened. The raw material supply path 13 passes through the raw material supply pipe 14 provided in the rear stator 4 and opens at the upper end of the apparatus. A bead separator 15 is provided on the left end side of the grinding chamber 12 in the figure. The bead separator 15 includes a screen 16 for separating the medium beads and the liquid raw material, and a product discharge pipe 17 through which the dispersed and finely pulverized liquid raw material is discharged. The liquid raw material subjected to the pulverization process in the pulverization chamber 12 is separated by the screen 16, and only the raw material pulverized to a desired size is discharged from the product discharge pipe 17 to the outside of the machine.

  In the crushing chamber 12, medium media (micro beads) are accommodated (not shown). As this medium, fine beads having a diameter of 1 to 0.1 mm made of a material such as a steel ball, ceramic, or glass are used. A necessary amount (for example, about 50 to 100% of the volume of the crushing chamber) of these beads is charged into the crushing chamber 12 from the bead loading port 18 provided on the front side of the front stator 3 before starting operation. . During operation of the apparatus, the bead inlet 18 is closed by the stator plug 19.

  Here, in the bead mill 1 according to the present invention, protrusions projecting in the axial direction (the extending direction of the rotating shaft 7) are provided on both end surfaces of the rotor 2 in the axial direction. That is, as the protrusion, a pin 21 is provided on the front side (left end side in FIG. 1) of the rotor 2, and a pin 22 is provided on the rear side (right end side in FIG. 1) of the rotor 2. 2A is an explanatory view showing the configuration of the pin 21, FIG. 2B is an explanatory view showing the configuration of the pin 22, FIG. 3A is an end view of the front side (raw material discharge side) of the rotor 2, and FIG. 2 is an end view of the rear side (raw material supply side) of FIG.

  As shown in FIGS. 2A and 2B, the pins 21 and 22 are cylindrical, and end surfaces on the raw material discharge side (hereinafter referred to as front end surfaces) 23 of the rotor 2, end surfaces on the raw material supply side (hereinafter referred to as “end surfaces”). (Referred to as the rear end face) 24 and fixed with bolts or the like. In the bead mill 1, as shown in FIG. 3A, a plurality of pins (eight here) are provided on the rotor front end face 23 equally along the circumferential direction. On the other hand, as shown in FIG. 3B, a plurality of pins 22 (eight here) are provided equally on the rotor rear end surface 24 along the circumferential direction.

  In this case, the pin 21 and the pin 22 are arranged at a position outside of about a half of the radius of the rotor 2 from the rotating shaft 7 toward the radially outer side. If the protrusions such as the pin 21 and the pin 22 exist over the entire length of the radius, they become a great resistance against the rotation of the rotor 2. For this reason, power loss occurs, and excessive power is required. If the power is the same, the rotation of the rotor 2 is slowed and the grinding efficiency is deteriorated. Therefore, in the bead mill 1, an outside of about a half of the radius is selected as an effective protrusion position that can improve the grinding efficiency without causing a heavy load, and the pin 21 and the pin 22 are arranged there. Protruding parts are arranged.

  Further, in the bead mill 1, the beads can be efficiently retained in the pulverization zone without hindering the rotation of the rotor 2 by using a pin as the protrusion. Further, the pin is excellent in workability when manufacturing the rotor 2, and the present invention can be applied to the bead mill without incurring a large cost increase.

  In such a bead mill 1, the liquid raw material (object to be processed) supplied from the raw material supply pipe 14 is mixed and stirred with the medium beads in the pulverization chamber 12 and pulverized. At that time, in the bead mill 1 according to the present invention, since the protrusions are provided on the front end surface 23 and the rear end surface 24 of the rotor 2, the stirring force is increased and the medium beads are easily collected in the crushing chamber 12. For this reason, the medium beads remain in the crushing chamber 12 which is a crushing zone, and an efficient crushing process is possible. In the experiments by the inventors, the pulverized particle size was able to be reduced in a short time compared to the conventional apparatus regardless of the viscosity of the raw slurry (the pulverized particle size of about 1/3 of the conventional one was obtained by the treatment for 20 minutes). Possible). Moreover, the final pulverization particle size could be made smaller than the conventional one (less than half of the conventional one after 40 minutes of treatment). [Beads: φ0.5 mm zirconia, raw material slurry: calcium carbonate (d50 = about 7 μm) + water]

It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.
For example, in the above-described embodiment, the example in which the present invention is applied to a bead mill having a configuration in which the rotor outer diameter is increased from the raw material supply side toward the discharge side has been shown. It is also possible to apply the present invention to a bead mill configured to reduce the diameter from the side toward the discharge side. Note that when the outer diameter of the rotor is increased from the raw material supply side to the discharge side, the medium beads tend to stay in the crushing chamber, and a more efficient wet crushing process is possible.

  In the above-described embodiment, the configuration in which eight pins 21 and eight pins 22 are arranged is shown. However, the number of protrusions is not limited to these, and is appropriately determined depending on the processing target, product specifications, device size, and the like. It can be changed. Furthermore, each protrusion part of the front-end surface 23 and the rear-end surface 24 of the rotor 2 may not be a pin but a trapezoidal protrusion (agitating blade) as shown in FIG. In that case, for example, as shown in FIG. 4B, one end surface is a pin, and the other end surface is a trapezoidal stirring blade 25 (four in this case) on the rear end surface 24 and a pin is disposed on the front end surface 23. May be a feather. In the experiments conducted by the inventors, a configuration in which pins are arranged on both the raw material supply side and the raw material discharge side has the highest processing efficiency, and this combination is more preferable.

  The processing target of the bead mill according to the present invention is not limited to the above-mentioned liquid raw materials, and specifically, suspension polymerization method toner, emulsion emulsion method toner, ink jet printer ink, optical disc organic photosensitive agent, and photocopier photosensitive drum organic. Photoconductor, ink pigment (offset ink, gravure ink, insulating ink, aquatic ink, oil-based ink, flexographic ink), ballpoint pen ink (water-based and oil-based), photocatalyst titanium oxide, film photosensitive agent, tantalum (capacitor raw material) , Foundation raw materials, lipstick / manicure pigments, UV-cutting titanium oxide and zinc oxide, paint raw material pigments, liquid crystal color filters, chocolate, barium titanate, PZT (for piezoelectric ceramics such as zirconate titanate), etc. Is also applicable.

DESCRIPTION OF SYMBOLS 1 Bead mill 2 Rotor 2a Maximum diameter part 2b Inclination part 3 Front stator 4 Rear stator 5 Front plate 7 Rotating shaft 8 Mechanical seal 12 Grinding chamber 14 Raw material supply pipe 16 Screen 17 Product discharge pipe 18 Bead insertion port 19 Stator plug 21 Pin 22 Pin

Claims (4)

A stator having a cylindrical hole-shaped internal space with an inner peripheral surface without unevenness ;
A cylindrical single rotor having an outer peripheral surface without unevenness, which is attached to a rotary shaft and rotatably arranged in the internal space of the stator;
Formed between the inner peripheral surface of the stator formed in a similar shape to each other and said outer peripheral surface of said rotor, and a grinding chamber without the stator side and the rotor side are both irregularities therein, the Prepared,
In the pulverization chamber, while rotating the rotor, a liquid bead to be processed and medium beads are mixed and stirred, and a wet bead mill for crushing the to-be-processed into desired fine particles,
A raw material supply pipe that opens to one end side in the axial direction of the internal space and supplies the workpiece to the grinding chamber;
A bead separator provided on the other axial end side of the internal space, for separating the object to be processed and the medium beads;
A product discharge pipe disposed downstream of the bead separator and discharging the workpiece separated from the medium beads by the bead separator to the outside of the stator;
The stator has an inner diameter that increases from the one end side toward the other end side,
The rotor, so that the distance between the inner peripheral surface of the stator is substantially the same, the direction from one end to the other end side, and its outer diameter is enlarged,
The rotor further increases the stirring force so that the medium beads are easily collected in the grinding chamber. The axial end surface on the one end side located on the raw material supply side and the other end side located on the raw material discharge side. Each of the axial end faces has a protrusion protruding in the axial direction,
A plurality of the protrusions are provided along the circumferential direction at positions outside the half of the radius of the rotor from the rotating shaft toward the radially outer side,
A bead mill characterized in that, in the internal space, a protrusion is provided only on the end surface in the axial direction of the rotor, and the stator does not have a protrusion on the surface facing the end surface in the axial direction of the rotor. The bead mill according to claim 1,
The bead mill, wherein the protrusion is a trapezoidal blade protruding from the axial end face of the rotor or a pin attached to the axial end face of the rotor. The bead mill according to claim 2,
Both the protrusions disposed on the end surface on the one end side located on the raw material supply side of the rotor and the protrusions disposed on the end surface on the other end side located on the raw material discharge side of the rotor are pins. A bead mill characterized by being. The bead mill according to claim 2,
The protrusion disposed on the end surface on the one end side located on the raw material supply side of the rotor is a trapezoidal blade, and the protrusion disposed on the end surface on the other end side located on the raw material discharge side of the rotor Bead mill characterized in that the part is a pin.

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