JPH0587307B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a centrifugal processing method and apparatus for pulverizing the medium by applying a high centrifugal force to the medium.

Furthermore, the present invention is applicable not only to pulverization but also to mixing, stirring, dispersion, and the like. Specifically, industrial ores and inorganic chemicals such as limestone, titanium oxide,
Can be used for crushing and mixing magnesium oxide, mica, calcium carbonate, magnetic iron oxide, ceramics, inks, paints, etc., and also for fuel-related mixing of water and coal, oil and coal, etc. I can do it.

Moreover, the present invention can be applied to either a wet type or a dry type.

[Conventional technology]

There have been various methods of pulverizing using media, but large-scale methods include ball mills and vibration mills, which involve placing media in a container and moving it to bring it into contact with the solid to be pulverized. It increases efficiency. In addition, there is also a method in which a stirrer is inserted into a stationary cylinder and rotated, and the media and the material to be crushed are placed in the space between the stirrers and the stirrer is moved batchwise or continuously.

[Problem to be solved by the invention]

However, in the case of these conventional ball mills, the mill rotation speed is about 20 to 40 rpm, and there is a limit in that the media moves under gravity. That is, in a horizontal ball mill, for example, although the container is rotated, the balls that rise as the container rotates only fall near the top, and their momentum is extremely small. On the other hand, in the stirring type, although the media moves violently, centrifugal force does not substantially act on the media.

Therefore, in this type of conventional method, when a highly concentrated slurry is used for pulverization, the media and the slurry flow in the same way, making it difficult to perform efficient and fine pulverization.

On the other hand, in recent years, mills that rotate at relatively high speeds have been developed, but since the media and the material to be processed flow in the same direction, there is a limit to the diameter of the fine powder that can be obtained.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and to provide a centrifugal processing method and apparatus thereof that can obtain ultrafine powder particles and have extremely high pulverization efficiency.

[Means to solve the problem]

The method of the present invention that solves the above problems is to provide a stirring shaft with a distance d that satisfies the condition of 0.50≦d/R≦0.95 in a hollow rotating body with an inner radius R, and to interpose a processing medium between the , while the object to be processed is present in the same space, the rotating body is rotated and the stirring shaft is rotated in a direction opposite to the rotating direction of the rotating body, so that the processing medium is subjected to a centrifugal force exceeding 1 G. It is characterized by being made to exercise with.

In addition, the apparatus of the present invention includes a hollow rotating body in which an inlet of a material to be processed is formed at one axial end and an outlet formed at the other axial end; a first rotational driving means for rotating the hollow rotating body; and a first rotation driving means for rotating the hollow rotating body so that the inner radius R of the hollow rotating body satisfies the condition of 0.5≦d/R≦0.95〓
a stirring shaft disposed with an angle d; a second rotational drive means for rotating the stirring shaft around the axis in a direction opposite to the rotational direction of the hollow rotating body; a processing medium, and the first rotary drive means and the second rotational drive means move the processing medium under a centrifugal force of more than 1 G.
The invention is characterized in that the rotary drive means of FIG.

[Effect]

That is, in the present invention, a hollow rotating body or the like serving as a container is rotated. This rotation itself is the same as in the case of a ball mill, etc., but whereas in the case of a conventional ball mill, the processing media was moved under gravity, in the present invention, the media is subjected to centrifugal force exceeding 1G. There is a clear difference in some respects, as the movement is caused by the action of

Furthermore, it is difficult to perform effective pulverization simply by rotating the hollow rotating body at high speed. Therefore, a stirring shaft is provided inside the hollow rotating body, and this stirring shaft is rotated at high speed in the opposite direction to the hollow rotating body. In this way, when the media is placed in a centrifugal force field and stirred by the stirring means with different rotational directions, the force applied to the media increases and uniform stirring is achieved. As a result, the contact area (per unit time) between the media increases, the collision force and shearing force increase, and it becomes possible to grind to ultra-fine powder, which has been difficult to achieve in the past.

In this case, the relationship between the inner radius R and the distance d of the hollow rotating body is 0.5≦d/R≦0.95. If the distance d is made small so that d/R<0.50, this is desirable in that the centrifugal force is made uniform and the crushing effect is made uniform, but the throughput becomes small. Further, when d/R>0.95, the stirring effect by the stirring shaft becomes small.

In this case, more effective stirring can be achieved by providing a protrusion on the stirring shaft, by providing a protrusion on the inner surface of the hollow rotating body, or by employing both means.

〔Example〕

Next, the present invention will be explained in more detail with reference to embodiments shown in the drawings.

1 is a hollow rotary body, 2 is a stirring shaft provided inside the body, and 3 is a stand for these. The rotating body 1 has its shaft portion 1a rotatably supported by an arm 4 integrated with a pedestal 3 via a bearing 5. The shaft portion 2a of the stirring shaft 2 is also rotatably supported by an arm 6 integrated with the pedestal 3 via a bearing 7.

The shaft portion 1a is connected to an inlet 9 for the object M to be processed via a rotary joint 8. In addition, a screen 1 is provided in the opening 1c of the upper plate 1b constituting the rotating body 1.
0 is provided and is connected to the outflow chamber 11 to be rotated. A part of the outflow chamber 11 has an outlet 1 for the crushed material M′.
2 is formed.

On the other hand, a V-pulley 13 is attached to the shaft portion 1a of the rotating body 1.
A first drive motor 14 is fixed to the frame 3, and a pulley belt 16 is wound around the V-pulleys 15 and 13 of the output shaft of the first drive motor 14. Further, a V-pulley 17 is fixed to the shaft portion 2a of the stirring shaft 2, and a second drive motor 18 is fixed to the frame 3, and a pulley belt 20 between the V-pulley 19 of the output shaft and the V-pulley 17 is fixed to the shaft portion 2a of the stirring shaft 2. It's wrapped around. Due to these, the rotating body 1 and the stirring shaft 2 rotate around their axes.

A large number of protrusions 21, 21, . . . are formed on the outer peripheral surface of the stirring shaft 2. Between the inner surface of the rotating body 1 and the outer surface of the stirring shaft 1, there is a material made of, for example, ceramic.
A media 22 is installed inside.

During the movement of such a processing device, the object to be processed M
is supplied from the inlet 9 to the above-mentioned space. In this state, the rotating body 1 and stirring shaft 2 are rotated. At this time, preferably the directions of rotation of both are reversed. The speed of the rotating body 1 is selected so that a centrifugal force of more than 1G, preferably about 10G to 200G, acts on the media 22. Along with these rotations, the media 22 moves together with the object to be processed, and in the course of its movement, it collides with the projections 21, the inner surface of the rotating body 1, and the outer surface of the stirring shaft 2, resulting in violent stirring motion. As a result, large compressive force, shearing force, etc. are applied to the material to be processed, and the material is pulverized.
The treated material is discharged from the outlet 12 of the outflow chamber 11 through the aperture 1c and the screen 10.

Incidentally, it is preferable that the difference between the inner radius R of the rotating body 1 and the outer radius r of the stirring shaft 2, d, is smaller because the centrifugal force acting on the media is made uniform and the crushing effect is made uniform. However, since the processing capacity becomes smaller, considering this point, the d/R ratio should be 0.50~
0.95 is preferred, particularly 0.80 to 0.95.

Furthermore, in the present invention, the object to be processed may be supplied together with a liquid, for example, in a slurry state, or may be supplied in a dry state. Furthermore, it may be a batch type or a continuous type. Moreover, it is natural that the present invention can be made into a horizontal type such as a horizontal ball mill due to its crushing principle.

The direction of rotation of the stirring shaft 2 can be the same as the direction of rotation, but in the present invention, in order to enhance the pulverizing effect, it is rotated particularly in the opposite direction at high speed. In order to rotate these, two types of drive motors are used in the above example, but it is also possible to drive them with one motor using appropriate shafts and gears. The term "first and second rotational driving means" as used in the present invention also includes the meaning of sharing the first and second rotational driving means.

On the other hand, as shown in FIG. 2, protrusions 23 may be formed on the inner surface of the rotating body 1 for stirring. The protrusions may be formed on both the rotating body 1 and the stirring shaft 2, but it is of course possible to form the protrusions on either one. For stirring, stirring blades 24, 25 as shown in FIGS. 3 and 4,
A disk blade 26 as shown in Fig. 5, a screw type blade 2 that also adds an axial transfer force as shown in Fig. 6.
7 etc. may also be used. Further, the overall shape is not limited to a cylindrical shape, but may be a bowl-shaped longitudinal section as shown in FIG. 7 or a substantially hexagonal longitudinal section as shown in FIG. 8.

The media may be made of ceramic, hard plastic, metal, etc., and may be spherical, rod-shaped, etc. as appropriate. The size may be appropriately selected depending on the processing purpose.

(Example) Grinding characteristics were investigated using the apparatus shown in FIG.
Cylinder with protrusions on the inside diameter 250mm, height 180mm
A rotating body with an inner disk opening diameter of 100 mm and a rotating shaft provided at the center of the bottom disk was rotated at a speed of 600 rpm.

The stirring shaft had a diameter of 210 mm and a height of 170 mm; it was used as it was fixed.

The apparatus was fed with a 50% slurry of 87% pure limestone with an average particle size of 42μ (maximum diameter 80μ) at a rate of 180/hr. At this time, the diameter of the grinding media used was
They are 1.0mm ceramic beads. The size of the obtained fine particles was 1.8 μm at maximum and 0.3 μm on average. According to conventionally used crushers such as ball mills, the maximum diameter is 3.0 to 40 μm, and the average
The fact that it is 0.8 μm indicates that this pulverizer exceeds the limits of conventional pulverizers such as ball mills.

〔Effect of the invention〕

As described above, according to the present invention, the stirring shaft is provided in the hollow rotating body under predetermined conditions, and the media is
Because it is placed in a centrifugal force field exceeding 1G,
It is possible to obtain fine powder with a diameter that could not be obtained conventionally, and the pulverization efficiency is significantly higher than that of the conventional method.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the device of the present invention, Fig. 2 is a cross-sectional view of another example of the rotating body, Figs. 3 to 6 are front views showing other examples of the stirring shaft, and Figs. FIG. 8 is a schematic diagram of another example of the device having a different overall shape. DESCRIPTION OF SYMBOLS 1... Hollow rotating body, 2... Stirring shaft, 14, 15... Rotation drive motor, 22... Media, M... Processing object.

Claims (1)

[Claims] 1. Inside the hollow rotating body with an inner radius R of 0.50≦d/R≦
A stirring shaft is provided with a distance d that satisfies the condition of 0.95, a processing medium is interposed in the space, and the object to be treated is present in the space, and the rotating body is rotated. A centrifugal processing method, characterized in that a shaft is rotated in a direction opposite to the rotational direction of the rotating body, and the processing medium is moved under a centrifugal force of more than 1 G. 2. A hollow rotary body having an inlet for a processed material formed at one axial end and an outlet formed at the other axial end, and a first rotary body for rotating the hollow rotary body around its axis a rotational driving means; and a period within the hollow rotating body that satisfies the condition that the inner radius R of the hollow rotating body is 0.50≦d/R≦0.95.
a stirring shaft disposed with an angle d; a second rotational drive means for rotating the stirring shaft around the axis in a direction opposite to the rotational direction of the hollow rotating body; a processing medium, and the first rotary drive means and the second rotational drive means move the processing medium under a centrifugal force of more than 1 G.
What is claimed is: 1. A centrifugal processing device characterized in that a rotational drive means is operated.