JPS6140465B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ball mill that stirs a mixture of solid particles and a liquid together with a large number of hard balls to pulverize the solid particles into ultrafine particles and disperse them in a colloidal form in the liquid.

Such a ball mill includes a cylindrical container (either cylindrical or polygonal) and disks or arms fixed at intervals on a rotating shaft extending in the longitudinal axis direction of the container. Inside is a large number of hard balls that perform a crushing action. The mixture of solid particles and liquid to be ground is pumped into the container. As the disk rotates, the mixture and the hard spheres are constantly stirred, the solid particles are pulverized into very fine particles, uniformly dispersed in the liquid to form a colloid, and transferred to the discharge side of the container. It is necessary to separate the hard spheres when draining the colloidal dispersion. Conventionally, this has been done by placing a screen on an extension of the container, or by placing a screen around the discharge side of the shaft and rotating it together with the shaft so that the material to be processed is discharged along the shaft. The screen was severely worn and easily clogged. In order to solve this problem, a separation device has been proposed that includes a rotating disk on the upstream side of the discharge port and a fixed ring that has an inner diameter smaller than the outer diameter of the disk and is installed close to the disk. In this separator, the treated liquid mixture flows through the gap between the outer periphery of the disk and the surface of the ring, through the inner diameter of the ring, and toward the outlet, where the hard balls are stopped. left in the container. This structure requires precise processing and assembly in order to maintain the accuracy of the gap between the rotating disk and the fixed ring. Furthermore, since the total passage area of the gap is limited, there is also the disadvantage that a high viscosity liquid has a large passage resistance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a ball mill equipped with the above-mentioned disk/ring type separating device, which can be processed and assembled with minimal need for precision processing.

Another object of the present invention is to provide a ball mill equipped with the above-mentioned disc/ring type separator that can change the passage area according to the viscosity of the material to be processed or the particle size of the material to be crushed.

According to the present invention, a ball mill of the above type is equipped with a separation or hard ball blocking disk provided with a large number of radial slits in a position close to the discharge port of the rotating shaft, and these slits are formed in the disk. It extends from the outer circumferential edge to near the inner circumferential edge, and its width is smaller than the dimension of the hard ball. A fixing ring is provided in close proximity to the discharge side surface of the separating disk, and this fixing ring forms a working chamber in which the disk rotates and accommodates the grinding hard balls. The inner diameter of the fixing ring, ie the diameter of the central hole, is smaller than the outer diameter of the separation disc. Therefore, the treated colloid liquid flows toward the discharge port only through the flow path regulated by the inner end of the slit and the inner peripheral edge of the ring. The hard balls are blocked on the inlet side of the slit and remain in the container. In such an arrangement, it is only necessary to make sure that the width of the slit is smaller than the dimensions of the hard ball, and the separating disk is fixed on the rotating shaft as close as possible to the ring. Furthermore, if the fixed ring is designed to be removable, it is possible to replace it with another ring with a different inner diameter to change the radial distance between the inner end of the slit and the inner circumferential edge of the ring, thereby changing the passage area. .

The present invention will now be described in more detail with reference to the accompanying drawings.

Referring to Figure 1, the ball mill has a cylindrical container 1.
The container has an inlet 2 at one end and an outlet 3 at the other end. A rotating shaft 4 protrudes into the container 1 through one end wall, and is rotated by a drive device (not shown).

At the end of the rotating shaft 4 located inside the container, a plurality of stirring disks 5 are arranged at intervals in the longitudinal axis direction.
is fixed.

A ring 6 is installed in the container adjacent to its outlet 3 and forms a working chamber 7. A large number of hard balls (not shown) are placed in the working chamber 7, and when the disk 5 is rotated within the working chamber, these hard balls are stirred and their outer surfaces rub against each other.

A disc 8 for separation, that is, for blocking hard balls, is fixed to the rotary shaft 4 at a position within the working chamber and close to the ring 6, and the surface of this disc 8 for separation is as close to the surface of the ring 6 as possible. I've brought it close.
The outer diameter of this separation disc 8 is the inner diameter of the ring 6,
That is, it is larger than the diameter of the central hole 9, and is in a state where the central hole 9 is closed. The separation disc 8 is the third
As best seen in the figure, it has a number of radial slits 10, each extending from at or near the outer periphery of the disc 8 to near the inner periphery;
Its width is smaller than the hard ball dimension, for example 0.5
It is in millimeters. The inner end of each slit 10 is
Preferably, as can be seen in FIGS. 1 and 2, it is curved radially outward from a point close to the axis of rotation 4 in the direction toward the ring 6. The purpose of this will be explained later.

In such a configuration, the mixture of solid particles and liquid to be ground is fed into the container 1 under pressure through the inlet 2, when the rotating shaft 4 rotates and its disk 5 stirs the hard balls. The mixture to be treated is pulverized and stirred by the hard balls being stirred, and the solid particles are pulverized into extremely fine particles and dispersed in a colloidal form in the liquid.

The colloidal dispersion and the hard spheres are thus moved under the supply pressure towards the outlet 3 while being stirred. The hard balls that hit the separation disk 8 cannot enter the slits 10 as described above, and are therefore forced outward in the radial direction, and only the colloidal dispersion liquid enters the slits 10 of the separation disk 8. At this time, as described above, while being guided radially outward by the curved inner end of the slit 10, the larger particles are subjected to the action of centrifugal force due to the rotation of the disk 8, Only the colloidal particles having a small particle size flow together with the liquid through a channel formed by the inner end of the slit and the inner peripheral edge of the ring 6 toward the outlet 3. However, slit 1
Even if the inner end of the 0 is not shaped as shown, hard balls can be prevented and a liquid containing sufficiently crushed particles can be obtained. Further, the shape of the slit 10 of the disc 8 can also be made as shown in FIG.

Preferably, the ring 6 is removable. This is because the radial dimension of the flow path regulated by the inner end of the slit and the inner peripheral edge of the ring can be changed by replacing the ring with a ring having a central hole of a different diameter. By doing so, the passage area of the flow path can be changed according to the viscosity of the object to be treated or the viscosity of the particles to be crushed. Note that the total passing area can also be changed by changing the width and number of slits.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view showing a ball mill equipped with a separating device of the present invention, FIG. 2 is a cross-sectional view of a separating disk of the separating device of the present invention, and FIG. The front view and FIG. 4 are cross-sectional views showing other examples of the separation disk. 1... Container, 2... Inlet, 3... Outlet, 4...
Rotating shaft, 5... Stirring disk, 6... Ring, 8...
...Separation disk, 9...Central hole, 10...Radial slit.

Claims (1)

[Claims] 1. Having an inlet near one end and an outlet near the other end,
a cylindrical container, the inlet of which is connected to a source for supplying the material to be treated under pressure; a shaft extending along the longitudinal axis of the container and rotatably supported; A ball mill that includes a plurality of disks fixed at intervals in the longitudinal direction, a drive device for rotating the shaft, and a large number of hard balls that perform a crushing action and that are housed in the container. Adjacent to the outlet is a septum ring defining a working chamber in which the disc rotates and communicating with the inlet, the septum ring having a central hole through which the shaft passes. , the circumferential surface of the central hole is separated from the outer circumferential surface of the shaft, and a hard ball blocking disk is fixed to the shaft at a position close to the surface of the partition ring facing the working chamber; The diameter of the hard ball blocking disc is greater than the diameter of the central hole of the septum ring, and the hard ball blocking disc includes a number of radial slits in this circle having a width smaller than the dimensions of the hard ball. A ball mill characterized in that the ball mill is provided so as to extend from the outer peripheral edge of the plate or from the vicinity of the outer peripheral edge to the vicinity of the inner peripheral edge. 2. In the ball mill according to claim 1, an inner end of each slit provided in the hard ball blocking disk is curved radially outward from a point close to the axis in a direction toward the partition ring. A ball mill characterized by: 3. In the ball mill according to claim 1, the partition ring is removable,
A ball mill characterized in that it can be replaced with another partition ring having a different central hole diameter.