JP6011155B2 - Circulation type media stirring mill - Google Patents

Description

  The present invention relates to a circulation type media stirring mill. Specifically, the present invention relates to a configuration of a dispersion media separation mechanism provided in a circulation type media stirring mill used for pulverizing or dispersing particles into fine particles.

  The circulation type media agitation mill is an apparatus that can agglomerate agglomerates such as pigments and primary particles in a large amount to a desired particle diameter by the collision force and shearing force of the dispersion medium. This circulation type media stirring mill is used to continuously pulverize or disperse raw materials such as pigments, ceramics, and metal particles in a slurry into fine particles.

  In the circulation type media agitating mill, as a mechanism for separating the slurry in which the pigment or the like is dispersed and the dispersion medium, a pair of disks fixed at a predetermined interval and an impeller composed of a blade for connecting both disks are provided. A mechanism having a separator coaxially with a shaft is known (Patent Document 1). In this mechanism, by rotating the separator together with the shaft, the dispersion medium that has entered between the disks is blown outward in the radial direction of the rotating shaft, while the slurry is discharged through a discharge path provided in the shaft center.

  In addition, by providing a centrifuge for centrifuging the dispersion medium from the slurry in the middle of the flow path from supplying the undispersed slurry to discharging the dispersed slurry, the slurry and the dispersion medium are A mechanism for separation has been proposed (Patent Document 2).

International Publication No. 96/39251 JP 2002-306940 A

  In the separation mechanism disclosed in Patent Document 1, the slurry and the dispersion medium are well separated, but a shaft for discharging the slurry from the mill is formed in the shaft center of the rotating shaft, so that the shaft bearing is sealed. A mechanical seal is required. And the liquid mixture of a slurry and a dispersion medium contacts a mechanical seal. Since there is a gap in the sliding part of the mechanical seal, the solid matter in the slurry enters the gap of this sliding part and bites in, or the solid matter precipitates on the sliding part due to frictional heat, resulting in a sealing effect There was a problem of damage.

  In the separation mechanism of Patent Document 2, since there is a gap between the impeller of the centrifugal separator and the rotor wall located on the discharge opening side of the impeller, the dispersion medium enters the gap, and the discharge opening is left as it is. In some cases, the slurry is transported together with the slurry and discharged. Therefore, there has been a problem that the slurry and the dispersion medium are not sufficiently separated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a circulation type media agitating mill that can satisfactorily separate the object to be treated and the dispersion medium and is excellent in reliability.

As a result of intensive studies to solve the above problems, the present inventors have obtained the following knowledge.
(1) As a separator for a dispersion medium, a separator having a pair of disks arranged side by side with a predetermined interval and an impeller composed of a blade for connecting both disks is used. By providing a plurality of blades above the disk to be arranged, the dispersion medium that has wrapped around the top of the disk can be discharged by the flow formed by the plurality of blades. Thereby, it is possible to prevent the dispersion medium from being discharged out of the mill together with the raw slurry.
(2) By forming a through hole in the upper disk, the raw material slurry can be passed around the shaft instead of in the shaft and discharged out of the mill by overflow. As a result, contact between the bearing portion of the shaft and the raw slurry can be avoided, and the shaft need not be sealed with a mechanical seal.
The present invention has been completed based on the above findings.

The circulation type media agitating mill of the present invention has a supply port and a discharge port for a processing object, a mill main body in which the processing object and a dispersion medium are accommodated, and a shaft that is rotatably inserted into the discharge port. And a separator fixed to the shaft, the separator being spaced apart in the axial direction of the shaft with respect to the first disk and the first disk fixed to the shaft at a position near the discharge port A through-hole having a second disk arranged and a plurality of first blades connecting the first disk and the second disk, the first disk penetrating through the first disk in a thickness direction; If, have a said first second blade to cause a flow of radially outward during provided on a surface of the outlet side of the disk and the first disk and the mill body, of the outlet A recess for accommodating at least the second blade is formed in an inner wall of the mill body of the enclosure, and a lower end portion of an inner peripheral wall portion constituting the recess is located above the first disk, and A surface of the peripheral wall portion that faces the shaft is located on the outer peripheral side with respect to the through hole .

  A plurality of the second blades may be arranged at regular intervals along the circumferential direction of the first disk.

  The concave portion may be a ring-shaped concave groove surrounding the discharge port.

  It is good also as a structure where the outer peripheral wall part of the said ditch | groove is formed higher than the inner peripheral wall part of the said ditch | groove.

  The distance between the second blade and the inner wall surface of the recess may be 0.1 mm or more and 5 mm or less.

The circulation type media agitation mill of the present invention includes a separator in which a first disk and a second disk are connected by a plurality of first blades, and the processing object separated from the dispersion medium by the rotation of the first blade. Is made to flow into the discharge port through the through hole provided in the first disk, and discharged to the outside of the mill body. Further, the second blade is formed on the surface of the first disk on the discharge port side, thereby preventing the dispersion medium from entering the gap between the first disk and the inner wall of the mill body from the outside of the separator.
As described above, only the object to be processed can be allowed to flow out of the discharge port provided with the shaft bearing portion without sealing the shaft bearing portion with the mechanical seal. Therefore, it is possible to satisfactorily separate the object to be processed and the dispersion medium, suppress the occurrence of a problem of the shaft bearing portion due to the dispersion medium, and obtain excellent reliability.

The figure which shows the circulation type media stirring mill which concerns on embodiment. The top view of the 1st disk. The perspective view which looked at the 1st disk from the upper surface side. The bottom view of the 1st disk. The perspective view seen from the lower surface side of the 1st disk. Sectional drawing which expands and shows the principal part of a circulation type media stirring mill.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. This embodiment is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified.
In the present embodiment, the X axis and the Y axis are set along the horizontal plane, and the Z axis is set upward along the vertical direction.

FIG. 1 is a view showing a circulation type media stirring mill according to the present embodiment.
As shown in FIG. 1, the circulation type media agitation mill 100 is connected to a raw material tank 101 in which raw material slurry (object to be processed) is stored and a pump 102 to form a raw material slurry circulation cycle.
The raw material slurry used in the present embodiment is a liquid in which granular or powdery pulverized objects are dispersed in a dispersion medium (water, organic solvent, etc.). The dispersion media used in the circulation type media stirring mill 100 is a granular material having a predetermined hardness, such as zirconia beads, glass beads, titania beads, metal beads.

  The circulation type media stirring mill 100 includes a cylindrical mill body 4 filled with a dispersion medium, pins 5 and a separator 17 disposed inside the mill body 4, and a shaft provided on a top wall portion of the mill body 4. A sealing device 16 and a shaft 15 supported by the shaft sealing device 16 and connected to the separator 17 and the pin 5 are provided.

  The mill body 4 is a vertical container, and is provided in a cylindrical portion 4a, a disk-shaped bottom wall portion 4b that closes a lower opening of the cylindrical portion 4a, and an upper opening of the cylindrical portion 4a. And a disk-shaped top wall portion 4c that is attached onto the liner 9 and closes the upper opening of the cylindrical portion 4a.

  The bottom wall portion 4 b is provided with a supply port 3 formed through the bottom wall portion 4 b and connected to the output end of the pump 102. An opening 4d through which the shaft 15 is inserted is provided at the center of the top wall 4c. The liner 9 provided inside the top wall 4c is a ring-shaped member having an opening through which the shaft 15 is inserted.

  The shaft seal device 16 includes a flow path forming portion 18 placed on the top wall portion 4 c of the mill body 4 and a bearing member 19 provided on the upper surface of the flow path forming portion 18. The flow path forming portion 18 has an internal flow path 16a having an L shape in a side sectional view that opens to the bottom surface and side surfaces, and the opening on the bottom surface is connected to the opening 4d of the top wall portion 4c. The opening on the side surface of the flow path forming unit 18 is connected to the input end of the raw material tank 101. In the present embodiment, a flow path formed by the opening of the liner 9, the opening of the top wall 4 c, and the internal flow path 16 a is the discharge port 12.

  The bearing member 19 is provided on the extension of the vertical hole in the internal flow path 16 a, supports the shaft 15 in an upright posture, and seals the shaft 15 with a ring-shaped seal member 13 surrounding the shaft 15. The lower end side of the shaft 15 inserted through the bearing member 19 extends into the mill body 4 through the vertical hole portion of the internal flow path 16a. On the other hand, a pulley 15 a is provided on the upper end side of the shaft 15. A driving belt 28 that transmits the driving force of the driving unit 14 such as a motor is hung on the pulley 15a. Although it does not specifically limit as the sealing member 13, For example, a gland packing etc. can be used.

Inside the mill body 4, a separator 17 and a pin 5 are attached to the shaft 15 in order from the discharge port 12 side.
The separator 17 is a centrifugal separation mechanism provided in the mill body 4, and a disc-shaped first disk 8 attached to a portion of the shaft 15 located near the lower surface of the liner 9 and a coaxial position below the first disk 8. And a plurality of first blades 7 for connecting the first disk 8 and the second disk 6 to each other. The shaft 15 passes through the center of the first disk 8 and the second disk 6, and the plurality of first blades 7 are arranged around the shaft 15 at regular intervals.

  Here, FIG. 2 is a top view of the first disk 8. FIG. 3 is a perspective view of the first disk 8 as seen from the upper surface side. FIG. 4 is a bottom view of the first disk 8. FIG. 5 is a perspective view seen from the lower surface side of the first disk 8. FIG. 6 is an enlarged cross-sectional view of a main part of the circulation type media stirring mill.

  As shown in FIGS. 2 and 3, the first disk 8 includes a disk-shaped disk base 8a, and a plurality (24 in the figure) of second blades 21 formed to protrude upward from the upper surface of the disk base 8a. Have.

  The second blades 21 are arranged at regular intervals along the circumferential direction of the first disk 8. Each of the second blades 21 is a plate-like member having a sharp corner, and is arranged in a posture to stand vertically on the disk base 8a. The second blades 21 are arranged such that their main plate surfaces are inclined with respect to the radial direction of the first disk 8, and a flow in the disk radial direction is generated by the rotation of the first disk 8. The angle between the main plate surface of the second blade 21 and the disk radial direction is not particularly limited. For example, it is 1 ° to 90 °, preferably 20 ° to 80 °, more preferably 30 ° to 50 ° in the horizontal plane. can do.

  The height (the length in the Z direction) of the second blade 21 may be adjusted as appropriate within a range in which a necessary flow can be formed on the upper surface of the first disk 8. For example, when the diameter of the first disk 8 is not less than 100 mm and not more than 130 mm, it is preferably not less than 10 mm and not more than 20 mm, more preferably not less than 13 mm and not more than 17 mm.

In the center of the disk substrate 8a, a rounded square disk fixing hole 22 is formed. Further, a frame 8b for reinforcing the fixing portion is formed along the periphery of the disk fixing hole 22.
Round hole bolt fixing holes 23 are formed at positions corresponding to the four sides of the disk fixing hole 22. At positions corresponding to the four corners of the disk fixing hole 22, elongated through holes 10 having a length corresponding to the interval between adjacent bolt fixing holes 23 are formed.

  The number and size of the through-holes 10 may be appropriately adjusted so that the raw material slurry can be smoothly fed to the discharge port 12. If the through-hole 10 is too small, the time required for one cycle becomes long, and if the through-hole 10 is too large, the strength of the first disk 8 itself becomes weak. And the number should be set. One or more through holes 10 may be provided.

  As shown in FIGS. 4 and 5, a plurality of long-hole-shaped engaging recesses 25 are formed on the lower surface of the first disk 8 (the surface on the second disk 6 side). The engaging recess 25 is a portion where one end of the first blade 7 that connects the first disk 8 and the second disk 6 is inserted and fixed. The engaging recesses 25 are formed at regular intervals along the circumferential direction of the first disk 8. In the case of this embodiment, 24 engagement recesses 25 are formed, and the separator 17 includes the same number (24) of the first blades 7 and the second blades 21. In the present embodiment, the number of the first blades 7 and the number of the second blades 21 is the same (24), but the number may not be the same.

  The engaging recess 25 is arranged so that its length direction is oblique to the radial direction of the first disk 8. That is, the main plate surface of the first blade 7 fixed to the engaging recess 25 is disposed so as to be inclined with respect to the radial direction of the first disk 8. The angle between the engagement recess 25 and the disk radial direction is not particularly limited. For example, the angle is 1 ° to 90 °, preferably 20 ° to 80 °, more preferably 30 ° to 50 ° in the horizontal plane. it can.

  The second disk 6 has substantially the same configuration as the first disk 8 except that the second disk 21 and the through hole 10 are not provided. That is, the disk fixing hole is formed in the center of the disk-shaped disk base, and the bolt fixing hole is formed around the disk fixing hole. On the upper surface of the second disk 6, a plurality of engaging recesses that are paired with the engaging recesses 25 shown in FIG. 4 are formed. The lower end portion of the first blade 7 is inserted and fixed in the plurality of engaging recesses. The second disk may be provided with a through hole similar to the first disk to the extent that the strength is not impaired.

  A plurality of pins 5 arranged at regular intervals along the axial direction of the shaft 15 are provided at a portion of the shaft 15 on the tip side of the second disk 6. The shape, mounting orientation, arrangement, etc. of the plurality of pins 5 are not particularly limited. For example, the pins 5 are rod-like or plate-like members, and the shafts such that their longitudinal directions are perpendicular to the axial direction of the shaft 15. 15 is fixed.

The liner 9 is provided at a position facing the upper surface of the first disk 8. In the case of this embodiment, the liner 9 has a concave groove (concave part) 32 for accommodating the second blade 21 on the first disk 8. ing. As shown in FIG. 6, the concave groove 32 includes an inner peripheral wall portion 9 a facing the inner end surface of the second blade 21, a top wall portion 9 b facing the upper surface of the second blade 21, and an outer end surface of the second blade 21. And an outer peripheral wall portion 9c facing each other.
In the case of the present embodiment, the height of the outer peripheral wall portion 9c is greater than the height of the inner peripheral wall portion 9a in the concave groove 32, and the second blade 21 and the height of the outer peripheral wall portion 9c are within the height range. Both of the first disks 8 are arranged.

  A gap 11 having a predetermined width is formed between the first disk 8 and the wall surface of the groove 32. The gap 11 may be formed around the second blade 21 so as to have a width of 0.1 mm or more and 5 mm or less, preferably 0.1 mm or more and 2 mm or less. By setting the gap 11 to the above value, the first disk 8 is prevented from coming into contact with the liner 9 during rotation and the dispersion medium is bitten, and the dispersion medium enters the discharge port 12 from the gap 11. Can be prevented.

  In the slurry circulation system including the circulation type media stirring mill 100 having the above configuration, the raw material slurry stored in the raw material tank 101 is conveyed by the pump 102 and supplied to the bottom surface of the circulation type media stirring mill 100. It is introduced into the mill body 4 from the mouth 3. In the mill main body 4, the separator 17 and the pin 5 are rotationally driven together with the shaft 15 by the driving force of the driving unit 14, and the dispersion medium accommodated in the mill main body 4 is agitated.

  The raw material slurry introduced into the mill body 4 is sequentially moved upward by the pressure of the raw material slurry continuously supplied from the pump 102 while being stirred together with the dispersion medium by the pins 5. The raw material slurry that has reached the separator 17 enters the region between the separator 17 and the inner wall portion of the mill body 4, and further enters the separator 17 through the gap between the adjacent first blades 7. That is, it enters from the side of the separator 17 to the inside. In addition, when the through-hole is formed in the plate | board surface of the 2nd disc 6, raw material slurry enters into the inside from the side of the separator 17, and the downward | lower direction.

  Inside the separator 17, a plurality of first blades 7 rotating together with the separator 17 form a flow from the shaft 15 toward the outside in the radial direction. Due to this flow, the dispersion medium having a high specific gravity is moved outward in the radial direction of the separator 17, so that the mixture of the raw material slurry and the dispersion medium is converted into the raw material slurry and the dispersion medium while moving upward in the separator 17. To be separated.

  Then, the raw material slurry separated from the dispersion medium is discharged to the discharge port 12 through the through hole 10 of the first disk 8. The raw material slurry that has entered the discharge port 12 rises in the vertical hole portion of the internal flow path 16 a, reaches the horizontal hole portion of the internal flow path 16 a, overflows, and is poured into the raw material tank 101 again. Thereafter, the circulation of the raw material slurry is repeated, so that the pulverization target object contained in the raw material slurry proceeds. As a result, a dispersion of particles having a desired particle diameter can be prepared.

  As shown in FIG. 6, the raw material slurry in the separator 17 flows into the discharge port 12 through the through hole 10 provided in the vicinity of the shaft 15 of the first disk 8. However, the flow path leading from the inside of the mill body 4 to the discharge port 12 is not limited to the flow path passing from the inside of the separator 17 through the through hole 10 but also from the outside of the separator 17 to the gap 11 passing through the concave groove (recess) of the liner 9. Can also be a flow path.

  In the region outside the separator 17 leading to the gap 11, the raw slurry and the dispersion medium exist, and the width of the gap 11 is larger than that of the dispersion medium so that the dispersion medium does not bite when the first disk 8 rotates. Is also formed large. Therefore, if no countermeasure is taken, the dispersion medium outside the separator 17 may enter the discharge port 12 through the gap 11. Then, the dispersion medium is mixed into the raw material tank 101 and the slurry obtained after the dispersion treatment is mixed. There is a possibility that the quality may deteriorate or the reliability of the shaft seal portion may be lowered due to the dispersion medium biting into the seal member 13.

  Therefore, in the circulation type media stirring mill 100 of the present embodiment, a plurality of second blades 21 are erected on the upper surface of the first disk 8. By providing the plurality of second blades 21, when the first disk 8 is rotated, a flow f toward the radially outer side of the first disk 8 is formed as shown in FIG. This flow f is a raw material slurry, or a mixed phase flow made up of raw material slurry and dispersion media, flows out from the edge of the first disk 8 and collides with the outer peripheral wall 9c of the liner 9, and after the collision, the outer periphery It moves downward along the wall 9c and flows out from the gap 11 into the mill body 4.

The flow f as described above is formed by the rotation of the second blade 21, thereby preventing the dispersion medium from entering the gap 11 from the mill body 4. Thereby, since mixing of the dispersion | distribution media to the discharge port 12 can be decreased very much, the separation efficiency of a dispersion | distribution media and raw material slurry can be improved. Moreover, since the inflow of the dispersion medium into the discharge port 12 is extremely reduced, the contact between the seal member 13 and the dispersion medium is reduced, and the occurrence of problems in the seal member 13 can be suppressed, and excellent reliability can be obtained. it can.
In addition, it is also preferable from the viewpoint of improving the reliability of the shaft seal device that the contact between the raw material slurry and the bearing member 19 is suppressed by appropriately adjusting the speed of the overflow.

  In the case of this embodiment, the outer peripheral wall portion 9c of the concave groove 32 that accommodates the second blade 21 is formed higher than the inner peripheral wall portion 9a, and the inlet portion of the gap 11 on the mill body 4 side is Since the disc 8 is formed between the side end face of the disc 8 and the outer peripheral wall portion 9c, the dispersive medium is less likely to enter the gap 11 from the mill body 4.

  In addition, since the inner peripheral wall portion 9a of the concave groove 32 is provided, when the raw slurry or the dispersion medium that has flowed into the concave groove 32 from the gap 11 is repelled to the discharge port 12 side by the second blade 21, Inflow to the discharge port 12 is inhibited by the inner peripheral wall portion 9a. Therefore, the dispersion medium that has flowed out from the gap 11 into the concave groove 32 is easily discharged to the mill body 4 side.

  Further, in the circulation type media agitating mill 100 of the present embodiment, after the raw material slurry flows out from the mill body 4 to the internal flow path 16a, the raw material slurry overflows in the side hole portion of the internal flow path 16a and is discharged to the raw material tank 101. . Therefore, by appropriately adjusting the flow rate of the raw material slurry into the mill body 4, the contact of the raw material slurry with the bearing member 19 provided on the ceiling portion of the internal flow path 16 a is reduced. A high liquid sealing function is not required. Therefore, it is possible to reduce the cost by using a gland packing or the like instead of an expensive mechanical seal as the seal member 13.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
In the circulation type media agitating mill 100 of the above embodiment, 58 volume% of 0.1 mm zirconia beads are filled in the mill body 4 and the fine metal powder having an average particle diameter of 50 μm to 60 μm is filled with propylene glycol monomethyl ether from the raw material tank 101. The raw material slurry to which acetate was added was supplied from the supply port 3. The motor rotating speed of the drive unit 14 was operated at 1650 rpm, and the raw slurry was circulated and pulverized.

  When the average particle size reached the target value, the mill was stopped to obtain a product slurry. When the obtained product slurry was applied to a mesh, no mixing of dispersion media was confirmed. That is, it was confirmed that the dispersion medium and the slurry can be satisfactorily separated by using the circulation type media stirring mill of this embodiment.

  DESCRIPTION OF SYMBOLS 3 ... Supply port, 4 ... Mill main body, 6 ... 2nd disk, 7 ... 1st blade, 8 ... 1st disk, 9a ... Inner peripheral wall part, 9c ... Outer peripheral wall part, 10 ... Through-hole, 12 ... Discharge port, DESCRIPTION OF SYMBOLS 15 ... Shaft, 17 ... Separator, 21 ... 2nd braid | blade, 32 ... Concave groove (concave part), 100 ... Circulation type media stirring mill

Claims (5)

A mill main body having a supply port and a discharge port for the processing object, in which the processing object and the dispersion medium are accommodated, a shaft rotatably inserted into the discharge port, and the mill main body fixed to the shaft And a separator housed in
The separator includes a first disk fixed to the shaft at a position in the vicinity of the discharge port, a second disk spaced apart from the first disk in the axial direction of the shaft, the first disk, A plurality of first blades connecting the second disk;
The first disk is provided in a through-hole penetrating the first disk in a thickness direction and a surface of the first disk on the discharge port side, and is radially outside between the first disk and the mill body. A second blade for generating a flow toward the
The mill body has a liner provided at a position facing the upper surface of the first disk,
The liner has an opening part through which the shaft is inserted and constitutes a part of the discharge port,
A concave portion for accommodating at least the second blade is formed at a position facing the upper surface of the first disk in the liner .
The lower end portion of the inner peripheral wall portion constituting the recess is located above the first disk,
The circulation type media agitation mill, wherein a surface of the opening facing the shaft is positioned on the outer peripheral side of the through hole.   The circulation type media stirring mill according to claim 1, wherein a plurality of the second blades are arranged at regular intervals along a circumferential direction of the first disk.   The circulation type media stirring mill according to claim 1 or 2, wherein the concave portion is a ring-shaped concave groove surrounding the discharge port.   The circulation type media stirring mill according to claim 3, wherein an outer peripheral wall portion of the concave groove is formed higher than an inner peripheral wall portion of the concave groove.   The circulation type media stirring mill according to any one of claims 1 to 4, wherein an interval between the second blade and the inner wall surface of the recess is 0.1 mm or more and 5 mm or less.

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