JPH084112Y2 - Dry type fine pulverization and classification equipment - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry fine pulverization / classification device for continuously supplying a pulverizing material and collecting fine powder as a product.

[0002]

2. Description of the Related Art Conventionally, a dry fine pulverization and classification device for continuously supplying and pulverizing and classifying a dry crushed material has been provided as several types of devices and has been widely used in each industrial field. For example, as shown in FIG. 5, in a vertical roller mill, a table 102 that horizontally rotates at the bottom of a vertically oriented cylindrical casing 101 and a plurality of rollers 103 that are rotatably supported.
The crushed material is continuously supplied to the crushing part consisting of and, and the crushed product is crushed by pressing between them, and the crushed product is sent to the classifier 104 equipped on the upper part of the casing by being placed on the ascending airflow that is jetted from the bottom part. Perform classification. The classifier 104 is formed by a rotating rotor having a large number of blades radially, and the coarse powder is splashed to the outer peripheral side by the centrifugal force, and the fine powder is prevailed by the centripetal force due to the vortex of the air to move from the rotor center to the outside of the casing
As the discharge collection. In a horizontal ball mill that is widely used for crushing cement clinker, etc., the crushing medium (balls) and crushed material are stored and crushed in a horizontal cylindrical rotating casing, and the fine powder discharged from the end is classified by a cyclone. Collect the product. On the other hand, after crushing with a vertical mill
There are many conventional technologies that have improved the collection of fine powder of
For example, JP-A-1-120949 discloses a vertical crushing cylinder.
Rotate the rotary blades inside the
Milling by the grinding action between the
The ultra-fine powder that is removed increases the milling efficiency, and the high purity
The invention is aimed at obtaining the production granules of. That
In order for the powder to be after the maximum diameter in the required particle size range in the latter stage of the crusher
The first accelerating device that promotes the powder and the powder that has the minimum particle size or more
Connect the second accelerating device, and connect it to the last dust collector to
It is configured to separate. As a result, ultrafine particles
Crushing efficiency because the dust is guided from the powder cylinder and collected by the dust collector.
No deterioration of the product and no inclusion of ultrafine particles in the product
Sings.

Recently, however, the research and development of functional materials used in various fields have progressed remarkably, and the fine powders of various materials used as the raw materials have a smaller particle size than ever, and the width of the particle size distribution is narrow. Nowadays, various qualities are required, and the conventional fine crushing and classifying devices cannot meet this demand. The planetary ball mill was developed to solve this problem. The general structure of the planetary ball mill is that a plurality of mill pots that revolve upon the rotation of the spindle are evenly arranged around the spindle (symmetrically if there are two, and equidistant from the spindle if there are three or more). The mill pot itself also rotates about its own axis of rotation. Specifically, a typical example is such that a planetary gear is provided around the outer periphery of a mill pot that rotates together with the main shaft, and the sun gear that meshes with the planetary gear is separately rotated or stopped to rotate the pot while revolving. In the usual rolling ball mill, the balls of the grinding medium and the crushed material cause a cascade motion in one rolling cylinder, and the crushed particles are crushed and abraded by the gravitational fall to grind the crushed material. Ball mill revolves at high speed,
The centrifugal force due to the rotational movement and the Coriolis force work synergistically to improve the crushing speed, and fine powder having an excellent particle size distribution can be obtained in a short time. In particular, the crushing power by high-speed rotation is outstanding, and for example, it is possible to obtain fine powder having an average particle size of several microns by charging silica sand of several millimeters size and operating for only a few minutes. General of planetary ball mill
As a conventional technique showing such a configuration, Japanese Patent Publication No. 34-00.
7493 gazette was found and is now widely known
Who should be evaluated in terms of listing the basic requirements of the principle and configuration
It can be said that this is one of the line technology. A continuous planetary ball
A bag filter is connected to the discharge side pipe of the mill,
Is connected to a turbo blower, so use a bug filter
Collects pulverized powder discharged from the planetary ball mill
And only the separated air will escape from the blower
With a general planetary ball mill that is still used today
The configuration of the crushing device is disclosed.

[0004]

By the way, the planetary ball mill exerts such a strong crushing force to obtain fine powder that could not be obtained by the conventional crusher, but it has not been a problem in the past. New obstacles began to stand out. When the pulverized material rapidly becomes fine and becomes finer to about several μm, the powder surface is activated, and further the force from the pulverizing medium is applied to the pulverized pulverized material to agglomerate between the fine particles and the surface of the coarse powder. On the contrary, the reverse crushing action of coarsening appears. Once the fine powder has aggregated, it is not easy to loosen it (crush), and it can be seen that a very strong cohesive force acts. An example of determining the strength of the cohesive force will be described with reference to FIG. 6. Talc raw material (average X ₅₀ =
When 4.7 μm) was treated under two kinds of dispersion conditions, it was examined how much the particle size distribution of the product after dispersion was different depending on both conditions. The particle size distribution shown by the white circles in the figure shows a powder which was subjected to an ultrasonic bath (ultrasonic vibration) of 60 W for 30 seconds, and the average particle size was dispersed to 3.4 μm. In addition, the particle size distribution indicated by the black circles in the figure is 5 with an ultrasonic homogenizer of 300W.
It shows the powder when strongly wet-dispersed for a minute, and the average particle size is 2.3 μm, which is a large difference. The former dispersion condition (60 W ultrasonic bath) described here is a standard process applied when measuring the particle size by regularly sampling from fine powder during normal flow work, but as shown in the figure,
With the talc raw material used as this sample, there was a considerable difference in the particle size of the product depending on the dispersion conditions, and it remained uncrushed by the dispersion action of the 60 W ultrasonic bath.
It proves that the 00W ultrasonic homogenizer contains a large amount of agglomerated coarse powder that is barely crushed for a long time.

In a planetary ball mill that can rapidly obtain ultrafine powder, it is finely pulverized and then agglomerates, resulting in a state of apparently no change from coarse powder due to strong agglomeration force, which significantly impairs the excellent function of the planetary ball mill. It is a thing.
From experience, fine powder of the reverse crushing phenomenon that does not disintegrate unless it is dispersed by a 300 W ultrasonic homogenizer does not disperse even when kneading into synthetic resin and remains in a coarse state, so it is only valuable as a coarse powder. No evaluation is given as ultrafine powder.

In order to solve the above problems, an object of the present invention is to provide a device in which a crushing device for obtaining ultrafine powder and a classifying device for crushing a reverse crushing phenomenon to maintain excellent quality are combined.

[0007]

A dry pulverizing and classifying apparatus according to the present invention is provided with a plurality of units which are revolved by the rotation of a main shaft for dry pulverizing and each of which rotates about its own axis of rotation. The mill pot of the above is evenly arranged around the main shaft, and a dry continuous planetary ball mill for pulverizing the crushed material supplied from the supply unit that revolves into the mill pot is provided, and the outlet side of the planetary ball mill has its own Reverse crushing phenomenon
A rotor that rotates at high speed to disintegrate and disperse agglomerated coarse powder
Connecting the rotating rotor type classifier was vertically, coarse particle collection device on the outlet side of該分classifier, solving the above problems by comprising a combination of fine particle collection device and the blower including fines after the crushing dispersion did. In addition, specifically, it is desirable that the fine powder collecting device is formed by the fine powder collecting by the cyclone and the ultra fine powder collecting by the bag filter.

[0008]

1 is a flow chart showing the operating procedure of the device of the present invention. In FIG. 1, the crushed material is supplied together with air to a dry continuous planetary mill by a feeder and a blower and crushed. The ground product is pneumatically transported to a rotary rotor classifier where it is classified into coarse and fine powders. The coarse powder is recovered as a coarse powder product by the recovery device. The fine powder is further pneumatically transported to a collecting device such as a cyclone and a bag filter, where it is collected and collected as a fine powder product. Only clean air passes through the collector and is blown into the atmosphere by the blower. Although the classifier is limited to the rotary rotor type, this is a type of centrifugal force type wind classifier that rotates a special cylindrical or disk-shaped classification rotor at high speed. The classification particle size is determined by the balance between the centrifugal force of the swirling airflow and the centripetal force of the suction air, which is formed by rotating a cylindrical basket-type rotor in which a large number of blades are radially arranged and made of a strip plate. For the coarse particles, the centrifugal force overcomes the centripetal force and descends along the wall of the classification chamber.On the other hand, for the coarse particles, the centripetal force overcomes the centrifugal force and passes through the blades to the inside, where it is collected in the recovery device through the exhaust pipe. ing.

The rotary rotor type classifier itself is not a new technology, but the classifier 1 in the vertical roller mill shown in FIG.
As shown in FIG. 04, it has been conventionally used for the purpose of separating a crushed product into coarse powder and fine powder. However, when the rotary rotor type classifier is combined with the continuous planetary ball mill, a completely different action from the conventional one occurs. That is, as already mentioned, the fine powder continuously discharged from the planetary ball mill is too finely pulverized, so that the surface is activated and agglomerated, and it may be apparently ground into a coarse powder, but the classification rotor The agglomerated coarse particles directly collide and disperse with each other, or the agglomerated coarse particles collide with each other on an eddy flow or a turbulent flow in the rotor to disperse each other. Such dispersing action is a special action that can be seen only in the inflow powder from the planetary ball mill in which agglomerates of ultrafine powder are mixed, and it can be said that the rotary rotor type classification also has a powerful and highly efficient dispersing function. .

[0010]

2 is a vertical sectional front view showing an embodiment of the present invention. As shown in the figure, the basic structure of the dry continuous planetary ball mill 1 is the same as in the prior art, in which the main shaft 11 shifts the rotation of the motor 12 and receives the revolution of the mill pot 13 which is evenly arranged around a plurality of shafts. Spindle 1 rotated by motor 12
1, a sun gear 14 is provided around the mill pot 13 and meshes with a planetary gear 15 provided around the outer periphery of the mill pot 13 to operate the rotation of the mill pot 13. The mill pot revolves around the main shaft at high speed while centering on its own central axis. Also spins. The crushed material S is put into the hopper 17 of the screw feeder 16 and is put on the rotation of the screw to be supplied to the inside of the mill pot 13 through the supply pipe 18 from the supply side shaft hole bored in the shaft center of the main shaft 11 quantitatively. And is crushed by the motion of the crushing medium charged in the mill pot. The pulverized fine powder communicates with the rotary rotor type classifier 2 through the outlet-side shaft hole 19. The classifier 2 sucks fine powder from below the vertically-oriented cylindrical casing 21, is guided upward, and is attracted to the rotor 23 that rotates at high speed by the motor 22. Only the fine powder with superior centripetal force is classified and discharged. At this time, however, the apparent coarse powder that has been inversely ground and aggregated is crushed and returned to the fine powder. The fine powder is divided into a fine powder F1 recovered when passing through the cyclone 3 and an ultrafine powder F2 recovered when passing through the bag filter 4, to be a product. However, when there is no need for this separation, it is possible to collect all of the bag filters as a batch product. The coarse powder R collected by the classifier 2 is directly used as a coarse powder product. The blower 5 sucks the finally cleaned air flow and discharges it into the atmosphere.

FIG. 3 shows that the continuous planetary ball mill shown in FIG. 1 has a centrifugal force of 160 G (160 times the acceleration of gravity on the earth),
When the rotor diameter of the rotary rotor type classifier is φ150 mm, the rotor speed is 220 Hz, and the air volume is 1.36 m ³ / min, the obtained coarse powder product R, fine powder product F1 collected from the cyclone, and bag filter The collected ultrafine powder product F2 shows the particle size distribution of 60 W ultrasonic bath dispersion treatment for 30 seconds (white circle) and 300 W ultrasonic homogenizer dispersion treatment for 5 minutes (black circle). is there. From the right side of the figure, R1, F
Curves peculiar to each product of 1 and F2 are shown, and even if the white circle and the black circle overlap and different dispersion processing is performed, the difference is hardly recognized,
This tendency does not change even if the particle size is small, so it perfectly matches the purpose. For example, the average diameter X ₅₀ of the fine powder product F1 recovered from the cyclone is 0.9 under both dispersion conditions.
7 μm, the average diameter X ₅₀ of the fine powder product F2 collected from the bag filter is 0.76 μm and the average diameter X of the coarse powder product R.
₅₀ was 2.43 μm. 30 by 60W ultrasonic bath
Since the dispersion condition of wet dispersion for seconds is the general dispersion condition at the time of particle size measurement as described above, it can be evaluated that the fine powder product and the coarse powder product obtained from the bag filter and the cyclone shown in FIG. As another example, as shown in FIG. 4, coarse powder is fed back to a feeder to re-grind and only fine powder can be produced as a product. On the other hand, it is directly supported from the outlet of the planetary ball mill.
Particle size distribution of ground and crushed powder, rotor type
Grain size distribution of coarse powder and fine powder separated by classifier
Experimental data recorded by diameter (μm), accumulation, frequency
is there. Frequency is the difference between one screen above and the next.
Is the weight percentage of particles that remain between the particle sizes. This test
Powder from the exit of the planetary ball mill at
When classified with a Ta-type classifier, the ratio of coarse powder to fine powder is 1: 2.
5, but the desired particle size up to 2.63 μm
80% of recovered fine powder if fine powder of
Of 36% immediately after the planetary ball mill was discharged.
Cumulative value 43 calculated by simple calculation excluding the outflow to the coarse powder side
It was much smaller than%. This means that coarse powder and fine powder
Considering the above-mentioned recovery rate after classification,
Data type classifiers are the same as classifiers in other types of crushers.
The rotor classifier, which has a different name and a different name
Although entering call stay the same, but the fact is simply the charged powder fine
Agglomerated apparent coarseness rather than the function of separating into coarse powder and coarse powder.
To clarify that the main mission is to crush and disperse powder
Have proved.

[0012]

[Effects of the Invention] The dry fine crushing and classifying device of the present invention uses a dry continuous planetary ball mill with an excellent crushing ability, and in this case, avoid it when crushing the processed material to several μm or less or 1 μm or less. It is possible to eliminate the reverse crushing phenomenon that could not be done, and it was difficult to produce up to now and required large power.
It is possible to efficiently produce a powder of m or less. If this equipment is adopted in the field, it will be possible to easily obtain ultrafine powder that could not be obtained with conventional fine powder and classification equipment, so it is possible to create new materials in each industrial field, such as effective functional materials. , It is also possible to make immense contributions in various fields.

[Brief description of drawings]

FIG. 1 is a flowchart of the present invention.

FIG. 2 is a vertical sectional front view showing an embodiment of the present invention.

FIG. 3 is a table illustrating the effect of the embodiment of the present invention.

FIG. 4 is a flow chart of another embodiment of the present invention.

FIG. 5 is a vertical cross-sectional front view illustrating one of the conventional techniques.

FIG. 6 is a chart showing problems in another conventional technique.

[Explanation of symbols]

 1 Dry type continuous planetary ball mill 2 Rotation rotor type classifier 3 Cyclone 4 Bag filter 5 Blower 11 Spindle 12 Motor 13 Mill pot 14 Sun gear 15 Planetary gear 21 Casing 22 Motor 23 Rotor

Claims (2)

[Scope of utility model registration request] 1. A dry fine pulverization and classifying apparatus for pulverizing a pulverized material in a closed space by continuously supplying the pulverized material and classifying the pulverized material after pulverization to recover fine powder as a product. A plurality of mill pots, which are revolved by the rotation of the main shaft and rotate about their own rotation shafts, are evenly arranged around the main shaft, and the milling material is supplied from a supply unit that revolves into the mill pot. A continuous dry planetary ball mill for crushing the above-mentioned planetary ball mill to the outlet side of the planetary ball mill.
At high speed to disintegrate and disperse agglomerated coarse powder by the original reverse pulverization
Connecting the rotor to rotate and vertically rotating rotor type classifier
And, coarse particle collection device on the outlet side of該分classifier, after the crushing dispersion
The dry fine pulverization / classification device is characterized by combining a fine powder recovery device including the fine powder of 1. and a blower. 2. The dry fine pulverization and classification apparatus according to claim 1, wherein the fine powder collecting device is formed by collecting fine powder by a cyclone and collecting ultra fine powder by a bag filter.