JPH078822A - Pulverizer - Google Patents

Abstract

PURPOSE:To alternatively pass a material to be pulverized through the agitating bar side and the rotating shaft side to eliminate the retention of flow and to obtain the uniform pulverizing effect by arranging partition plates for conducting the flow of the material to be pulverized to either of or both of the inner wall of a pulverizing chamber and the rotating shaft of an agitating bar. CONSTITUTION:Plural hollow disc-like partition plates 1 are arranged from the inner wall of a pulverizing chamber 3 toward a rotating shaft 5 and sealed and held by O-rings 9 and collars 8, and also the collars 8 are fixed to a pulverizing vessel 7 by plural tap bolts 10, 11. On the other hand, plural disc-like partition plates 2 and agitating bars 6 each are fixed to the rotating shaft 5 at the appropriate intervals in the diametral direction. And the material to be pulverized is fed into the pulverizing chamber 3 by a liquid transfer pump 12 and uniformly moved with the passage restricted by the partition plates 1, 2. That is, the material to be pulverized is alternatively passed through the tip side of the agitating bars 6 where the peripheral velocity is large and the pulverizing capacity is high and the rotating shaft 5 side where the peripheral velocity is small and the pulverizing capacity is low to obtain the uniform pulverizing effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a medium stirring type crusher.

[0002]

2. Description of the Related Art The crushing operation is a basic operation for controlling the properties of powder to a property according to the purpose of use, and is a technique essential for the recent development of new materials such as fine ceramics.

[0003] Due to such industrial needs, a higher performance crusher is required. At present, as one of the crushers industrially used, there is a medium stirring type crusher as shown in FIG. This is to fill a grinding chamber with a grinding medium such as steel balls, ceramics balls or plastic balls and a material to be ground, and stir it with a stirring rod 6 fixed to a rotating shaft 5 to grind the grinding chamber. The material is crushed by passing it once or more.

[0004]

In many cases, it is required that the material to be ground has a uniform particle size. In the conventional medium agitation type pulverizer, the peripheral speed of the stirring rod is smaller than the tip of the stirring rod in the vicinity of the rotation axis in the center of the pulverization chamber, and thus the pulverizing ability is low. In other words, since the crushing capacity depends on the position in the crushing chamber,
An object to be ground having a uniform particle size cannot be obtained.

On the side surface and the bottom of the crushing chamber, the movement of the crushing medium is suppressed and the crushing ability is low, which also causes the object to be crushed having a uniform particle size to be not obtained.

Under such circumstances, the shape and arrangement of the stirring rod are improved, and even if a means for forcibly circulating and moving the grinding medium and the object to be ground in the grinding chamber is taken, the upper and lower parts of the inner wall of the grinding chamber and In the low part, the crushed product cannot be circulated uniformly and remains, and the so-called dead zone cannot be eliminated, so that a crushed product having a uniform particle size cannot be obtained.

For example, even if a circulating mechanism is provided for allowing the material to be ground to pass through the grinding chamber a plurality of times, the material to be ground must always pass through a location having a small grinding capacity as described above, and the ground material has a uniform particle size. I can't get anything.

Further, if the rotation shaft is thickened and the length of the stirring rod is shortened to reduce the difference in peripheral speed between the tip of the effective stirring portion and the center of rotation, it is possible to reduce the unevenness of the pulverization. The chamber cross-sectional area becomes small, resulting in a decrease in processing capacity, and as a result, it becomes necessary to upsize the apparatus.

An object of the present invention is to provide a crusher that solves the above problems of the conventional crusher.

[0010]

According to the present invention, in order to solve the above-mentioned problems, in a device of a system in which an object to be ground is passed through a grinding chamber of a medium stirring type grinding machine one or more times, A partition plate for guiding the flow of the object to be ground is provided on either or both of the rotating shaft and the inner wall of the grinding chamber.

[0011]

In the crusher provided by the present invention, a partition plate is provided on either or both of the rotary shaft at the center of the crushing chamber and the inner wall of the crushing chamber to guide the object to be crushed and make uniform the crushing chamber. By ensuring the flow, retention is eliminated, and the crushing effect does not vary depending on the location in the crushing chamber, and the crushing effect is made uniform, so that the crushed particle diameter of the object to be crushed becomes uniform.

[0012]

EXAMPLES Examples of the present invention are shown below. FIG. 1 is a conceptual diagram showing the structure of an embodiment of the present invention. In the figure, the hollow disk-shaped partition plate 1 provided from the inner wall of the crushing chamber 3 in the direction of the rotation axis is sealed and held by an O-ring 9 and a collar 8, and the latter is fixed to the crushing container 7 by pressing bolts 10 and 11. To be done. A disk-shaped partition plate 2 and a stirring rod 6 are fixed to the rotary shaft 5 in the radial direction with appropriate intervals. Each of the stirring rods 6 has an angle with each other and is attached so as to rotate around the rotating shaft 5.

In this embodiment, the collar 8 has an inner diameter of 500.
mm, the substantial volume of the crushing chamber 3 was about 120 liters, and the inner diameter of the hollow disk-shaped partition plate 1 was 120 mm. The outer diameter of the disk-shaped partition plate 2 attached to the rotary shaft 5 is 440 m.
and the stirring shaft 6 having a diameter of 25 mm was attached to the rotating shaft 5 having a diameter of 60 mm so as to have a length of 170 mm in the radial direction to form a crusher.

The object to be crushed is fed into the crushing chamber 3 by the liquid feed pump 12. In the crushing chamber 3, the rotary shaft 5, the hollow disk-shaped partition plate 1 fixed to the rotary shaft 5, and the stirring rod 6 are rotated. The crushing medium and the object to be crushed move in a uniform manner as indicated by an arrow A, with the flow path being restricted by the hollow disk-shaped partition plate 1 and the disk-shaped partition plate 2 fixed to the rotating shaft 5.

That is, in the crushing chamber 3, the object to be crushed is guided so as to alternately pass through the tip side of the stirring rod 6 having a high peripheral speed and a high crushing capacity and the rotating shaft 5 side having a low peripheral speed and a low crushing capacity. As a result, a uniform crushing effect was obtained.

The crusher according to the present invention has a simple structure as described above, and the hollow disk-shaped partition plate 1 together with the collar 8 can be easily attached / detached to / from the crushing chamber 3 by the holding bolt 10. In addition, it has the feature that the maintenance of the device is easy.

When the pre-burned Mn-Zn ferrite powder was pulverized as the object to be pulverized by using the pulverizer of the present invention, the particle size of the object to be pulverized was measured by the Microtrack method and compared with the conventional method. It shows in Table 1. The average BET particle size of the pulverized product before pulverization is 0.83 μm.

The symbols D ₁₀ , D ₅₀ and D ₉₀ in Table 1 are
They represent cumulative 10% particle size (volume basis), cumulative 50% particle size (volume basis) and cumulative 90% particle size (volume basis), respectively, and D ₅₀ represents an average particle size.

[0019]

[Table 1]

As shown in the table, the condition under which the average particle diameters D ₅₀ are almost the same (grinding time) is 1.2 Hr according to the present invention, which is a short time as compared with 1.7 Hr of the conventional method. Moreover, the D ₉₀ is 3.49 μm in the present invention and 4.01 in the conventional method.
This shows that a more uniform particle size distribution, which is smaller than μm and has a small amount of coarse powder, can be obtained in a short time according to the present invention.

[0021]

As described above, according to the present invention, the object to be crushed is alternately passed through the tip side of the stirring rod having a high crushing ability and the rotating shaft side having a low peripheral speed and a low crushing ability. Since the flow was prevented from accumulating, crushed particles having a uniform particle size were obtained.

[Brief description of drawings]

FIG. 1 is an explanatory view showing the concept of the structure of a crusher made according to the present invention.

FIG. 2 is an explanatory view showing the concept of the structure of a crusher according to the related art.

[Explanation of symbols]

 1 Hollow disk-shaped partition plate (of the grinding chamber) 2 (Rotating shaft side) Disk-shaped partition plate 3 Grinding chamber 5 Rotating shaft 6 Stirring bar 7 Grinding container 8 Color 9 O-ring 10 Holding bolt 11 Holding bolt 12 Pump 13 Sludge Arrow indicating the direction 14 Arrow indicating the direction of sludge A Arrow indicating the flow of the crushed material

Claims (1)

[Claims] 1. A medium stirring type crusher comprising a crushing chamber for storing an object to be crushed and a crushing medium, and a stirring rod rotating shaft provided with a stirring rod provided in the crushing chamber. Either or both of the stirring rod rotary shafts,
A crusher comprising a partition plate for guiding the flow of the crushed object.