JP5159102B2 - Vertical media stirring mill - Google Patents

Description

  The present invention relates to a media stirring mill. The media agitation mill of the present invention is particularly suitable for use for pulverizing or dispersing raw materials such as inks, paints, pigments, ceramics, metals, inorganics, ferrites, toners, glass, and paper coating colors into fine particles. However, the present invention is not limited to this.

Various media agitation mills equipped with a centrifugal separation medium, that is, a centrifugal separator have been developed. For example, in Japanese Patent No. 3703148 (Patent Document 1), a dispersion agitation member and a centrifugal separator are attached to one axis. A mill is disclosed.
By the way, some raw materials change in quality during processing. In such a case, the dispersion force must be reduced. The dispersion force is generally reduced by reducing the rotational speed of the stirring member. However, when the rotational speed of the stirring member is reduced in this way, the above-described mill of Patent Document 1 uses a centrifugal separator as one axis. Since the rotation speed of the centrifugal separator is also reduced, the centrifugal force is reduced, the separation ability is extremely reduced, and there is a problem that the grinding medium flows out.

As a mill for solving such a problem, there is a media stirring mill disclosed in JP-A-2006-212488 (Patent Document 2). In this media stirring mill, the stirring member and the centrifugal separator can be driven separately, and the dispersion force and separation ability can be controlled separately, but the dispersion force is weakened and the separation ability is strengthened. Then, the centrifugal force of the centrifugal separator may affect the dispersion force.
As described above, various media agitation mills equipped with a centrifugal separator have been developed. However, there is a problem in that it is difficult to balance the dispersion force and the separation ability, which is not efficient.
Japanese Patent No. 3703148 JP 2006-212488 A

  Then, an object of this invention is to provide the media stirring mill which can obtain a required dispersion force and separation capability efficiently.

The above object is achieved by the media stirring mill according to the present invention having the following configurations (1) to (6).
(1) Cylindrical crushing tank having a raw material inlet channel on the upper end side, a stirring member rotatably arranged on the lower end side in the crushing tank, and centrifugal separation arranged rotatably on the upper end side in the crushing tank Type media separating member, a first drive shaft extending from the stirring member in a direction opposite to the media separating member and extending to the outside of the grinding tank, and extending from the media separating member to the opposite side of the stirring member and extending to the outside of the grinding tank A second drive shaft, a pulverization medium housed in the pulverization tank, and an inner peripheral wall of the pulverization tank, and extends from an upper end side in the pulverization tank to a lower end side in the pulverization tank; end, a turning member located above the vertical center of the agitating member, pulverized main and raw material oriented circumferentially outwardly by rotation of the stirring member And a stirring member and a media separation member that are spaced apart in the axial direction so as to reduce mutual interference. A vertical media agitating mill characterized in that the second drive shaft is formed of a hollow shaft, and the inside of the hollow shaft communicates with the internal space of the media separating member to form a raw material outlet path. .
(2) The media stirring mill according to (1), wherein the media separating member is an impeller.
(3) The above (1) or (1), wherein S / d is 0.3 or more, where S is the distance between the stirring member and the media separating member and d is the diameter of the stirring member. A vertical media stirring mill according to 2).
(4) The media agitation mill according to any one of (1) to (3) above, wherein the total volume of the pulverization media is 60% or less of the volume of the pulverization tank.
(5) The vertical media stirring mill according to any one of (1) to (4), wherein the stirring member can be driven at a rotational speed in the range of 5 to 40 m / s.
(6) The rod according to any one of (1) to (5), further including a rod-like member that fixes the base of the conversion member and has an upper end protruding from the upper wall surface of the crushing tank. Mold media stirring mill.

In the media agitation mill of the present invention, as described above, the agitation member and the centrifugal media separation member are arranged at a sufficient interval in the pulverization tank, so that the agitation member and the centrifugal media separation member are Each of them can exhibit its own performance without interference (or as small as possible).
In addition, by arranging the stirring member and the centrifugal media separating member at an interval, the grinding media inside the grinding tank is subject to rotational force and centrifugal force, and is likely to be vortexed. By providing a member, a radially inward flow was created in the slurry and media to allow rotational and axial flow.
As described above, the flow of the pulverization media is as if it were a mixer, and the pulverization media contact each other while moving, so that the raw materials are efficiently pulverized and dispersed.
Further, the media agitating mill of the present invention, even if the rotational speed of the agitating member is reduced, the centrifugal force of the media separating member does not affect the dispersion force so much. It is suitable for use as a raw material that may be lost.
Further, since the stirring member and the centrifugal media separating member are arranged at an interval, the space in which the grinding media can move is increased and the degree of freedom is increased. Therefore, even if the rotational speed of the stirring member is increased, the grinding media can be increased. It is possible to drive without the pack phenomenon. When the rotation speed of the stirring member is increased, the flow of the grinding media and the raw slurry becomes faster, the circulation flow is larger, and the feed slurry is larger than the supply (discharge) amount to the mill. Becomes smaller.
As described above, in the media agitating mill according to the present invention, conditions can be widely changed, and so-called mild dispersion is possible at a low peripheral speed operation of the mill with extremely small grinding media (microbeads), while high peripheral speed and high efficiency operation is possible. Is possible. Further, since the centrifugal media separating member can exert a large centrifugal force due to its small size and high speed, it has a large separating ability and there is no outflow of the grinding media.

Hereinafter, a media stirring mill according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the following description, a saddle type mill will be described, but the mill of the present invention may of course be a horizontal type.
FIG. 1 shows a media agitating mill 10 according to an embodiment of the present invention. The media agitating mill 10 includes a cylindrical vessel 12 having a closed lower end, and an end plate fixed to the upper end of the vessel 12. 14 and a crushing tank 20 having a raw material inlet passage 16 provided in the end plate 14. The inside of this crushing tank 20 is a sealed crushing chamber B. A frame 18 is fixed to the lower portion of the vessel 12. The slurry-like raw material is introduced into the pulverizing chamber B of the pulverizing tank 20 through the raw material inlet passage 16.

  A stirring member 22 is rotatably disposed in the lower part of the grinding chamber B of the grinding tank 20. The agitating member 22 includes a hub portion 22a disposed at the center, an arm 22b extending in a cross shape from the hub portion 22a, and an agitating member main portion 22c substantially in the shape of gear teeth supported at the outer peripheral tip of the arm 22b. Is integrated. The space between the arms 22b is a plurality of grinding media circulation openings 22d. A rotation drive shaft 24 is fixed to the hub portion 22a. The rotary drive shaft 24 extends through the end plate 14 and the frame 18 in the axial direction, and its end is connected to a drive source via a well-known drive mechanism (not shown), and is indicated by an arrow in the figure. It is rotationally driven in the direction. The rotary drive shaft 24 is provided with a shaft seal 25 (mechanical seal or the like). As is well known in the media agitation mill, a bead-like grinding medium 30 (shown extremely enlarged in the figure) is accommodated in the grinding chamber B. The pulverization medium 30 may have a diameter of 0.02 to 2 mm.

  Centrifugal type for separating the media 30 dispersed in the slurry-like raw material from the raw material, which is disposed in the upper part of the grinding chamber B of the grinding tank 20 at an axial distance from the stirring member. A media separation member 32 is provided. The media separating member 32 is of a centrifugal impeller type and is preferably arranged coaxially with the stirring member, but the axis may be shifted. A hollow rotary drive shaft 34 is fixed to the media separating member 32. The drive shaft 34 extends upward through the end plate 14, and its end is connected to a drive source via a well-known drive mechanism (not shown) and is driven to rotate in the direction indicated by the arrow in the figure. . The rotary drive shaft 34 is provided with a shaft seal 36 (mechanical seal or the like). The hollow portion of the drive shaft 34 communicates with the internal space of the media separating member 32 to form a raw material outlet path 38.

  A flow diverting member 40 (only one is shown in FIG. 1) is arranged above the vicinity of the inner peripheral wall in the crushing chamber B of the crushing tank 20. The flow converting member 40 is in the shape of a current plate, and has the effect of converting the flow of the raw slurry and the grinding media 30 directed outward in the circumferential direction by the rotation of the stirring member into the radially inward direction. Eggplant. When the rotational speed of the stirring member 22 is increased by the action of the flow changing member 40, the pulverized media 30 is prevented from sticking to the inner peripheral wall of the vessel 12 due to centrifugal force. As for this flow change member 40, it is desirable to arrange | position at least 1 in the crushing chamber B, Usually, it is one to two. It is preferable that the lower end of the flow conversion member 40 is substantially above the upper end of the stirring member 22, and the upper end thereof extends to the vicinity of the end plate 14. As shown in FIG. 2, the horizontal cross-sectional shape of the flow diverting member 40 is preferably a tapered shape whose thickness becomes thinner as it approaches the inner peripheral wall of the vessel 12.

A rod-shaped member 42 whose upper end protrudes outside the grinding tank 20 is attached to the base of the flow switching member 40 so that the angle and height position of the flow switching member 40 can be adjusted from the outside of the grinding tank 20. It is preferable to keep it.
Further, the media separating member 32 has a plurality of blade members 44 arranged at equal intervals in the circumferential direction (coaxial to the rotation drive shaft 34) between the hub portion 32a and the closing plate 32b (FIG. 3A). )reference). The blade members 44 may be arranged in a completely radial manner as shown in FIG. 3A, or may be arranged in an inclined manner as shown in FIG. 3B. Alternatively, the blade member 44 may have a quadrangular shape whose cross section gradually becomes narrower inward as shown in FIG.

When the distance between the stirring member 22 and the media separating member 32 is S, and the diameter of the stirring member is d, S / d is preferably 0.3 or more, particularly 0.3 to 0.6. . When the value of S / d is less than 0.3, the degree of interference between the stirring member and the media separating member is not preferable.
The total volume of the grinding media 30 is preferably 60% or less, particularly 30 to 50% of the volume of the grinding tank 20 (grinding chamber B). When the total volume of the grinding media 30 exceeds 60% of the volume of the grinding tank 20 (grinding chamber B), the degree of freedom of the grinding media 30 is lost and the control of the grinding media 30 becomes difficult. Further, it is desirable that the height position of the media separating member 32 is higher than the horizontal height when the grinding media 30 is charged into the grinding tank 20 (grinding chamber B). If the input horizontal height of the grinding media exceeds the height of the media separating member, the ability to separate the grinding media by the media separating member is lowered.
In the media stirring mill of the present invention, the stirring member 22 can be driven at a rotational speed in the range of 5 to 40 m / s, and the media separating member 32 is driven at a rotational speed in the range of 10 to 20 m / s. Is possible.

  In operation, the stirring member 22 is driven to rotate while introducing the raw material, which is a slurry containing particles to be crushed, from the raw material inlet passage 16. The slurry introduced into the crushing chamber B is moved in the direction of the stirring member 22 on the slurry already formed in the crushing chamber B and the rotating flow f of the medium 30 and stirred. The rotational flow f of the slurry and the medium 30 is generated by converting the radially outward flow formed by the stirring member 22 radially inward by the action of the conversion member 40. Due to the rotational flow f of the pulverizing media, the pulverized particles in the slurry are pulverized or dispersed in the pulverizing chamber B. At this time, since the stirring member 22 is sufficiently separated from the media separating member 32, the interference of the media separating member 32 is extremely small. In the upper part of the crushing chamber B, the slurry and the medium are rotated by the media separating member 32. By this rotational motion, the medium having a large specific gravity is biased radially outward and separated from the slurry. In this case, among the particles to be pulverized, particles that are not sufficiently pulverized and have a large particle size behave similarly to the media. On the other hand, the slurry containing particles that have been sufficiently pulverized and have a reduced mass enters the internal space of the media separating member 32 and is discharged to the outside of the media agitating mill via the raw material outlet passage 38 inside the rotating shaft 34. This configuration makes it possible to achieve pulverization with a narrow particle size distribution width.

It is sectional drawing which shows the media stirring mill by the embodiment of this invention. It is a figure explaining the arrangement | positioning state of a stirring member and a flow change member. (A), (B), (C) is sectional drawing which shows the example of the blade member of the media separation member currently used for the media stirring mill shown in FIG. 1, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Media stirring mill 12 Vessel 14 End plate 16 Raw material inlet path 18 Frame 20 Grinding tank 22 Agitation member 22a Hub part 22b Arm 22c Agitation member main part 22d Opening for grinding media circulation 24 Rotation drive shaft 25 Shaft seal 30 Grinding media 32 Media separation Member 32a Hub portion 32b Closure plate 34 Hollow drive shaft 36 Shaft seal 38 Material outlet path 40 Flow diverting member 44 Blade member

Claims (6)

Cylindrical pulverization tank having a raw material inlet channel on the upper end side, a stirring member rotatably disposed at the lower end side in the pulverization tank, and centrifugal media separation disposed rotatably at the upper end side in the pulverization tank A first drive shaft extending from the stirring member in the opposite direction to the media separating member and extending to the outside of the grinding tank; a second drive extending from the media separating member to the opposite side of the stirring member and extending to the outside of the grinding tank The shaft, the grinding media housed in the grinding tank, and the inner peripheral wall of the grinding tank are arranged in the vicinity of the inner peripheral wall of the grinding tank, and extend from the upper end side in the grinding tank to the lower end side in the grinding tank. , vertical center than a conversion member on the upper side, raw materials and the grinding media oriented circumferentially outwardly by rotation of the stirring member of the agitation member A diverter that changes the flow radially inward, wherein the agitating member and the media separating member are spaced apart in the axial direction so as to reduce mutual interference; A vertical media agitation mill characterized in that a drive shaft is formed of a hollow shaft, and the inside of the hollow shaft communicates with the internal space of the media separating member to form a raw material outlet path. Vertical media 攪拌mill according to claim 1, wherein the media separating member is characterized in that the impeller. The spacing between the agitating member and the media-separating member and S, when the diameter of the stirring member is d, vertical according to claim 1 or 2 S / d is equal to or less than 0.3 Mold media stirring mill. The vertical media stirring mill according to any one of claims 1 to 3, wherein the total volume of the grinding media is 60% or less of the volume of the grinding tank. 5. The vertical media stirring mill according to claim 1, wherein the stirring member can be driven at a rotational speed in a range of 5 to 40 m / s. Furthermore, it has a rod-shaped member which fixed the base part of the said conversion member, and made the upper end protruded from the upper wall surface of the said crushing tank, The bowl-shaped media stirring mill in any one of Claims 1-5 characterized by the above-mentioned.

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