JPS6136464B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a pulverizer, and specifically relates to a pulverizer that can pulverize particles of a material to be pulverized into fine particles on the order of microns or more than 10 microns. be.

A conventional pulverizer has a large number of rectangular recesses 1a along the generatrix of the outer surface as shown in FIGS. 1 and 2.
A cylindrical rotor 2 having an uneven surface in which rectangular convex portions 1b are arranged circumferentially is supported on a vertical rotating shaft 3, and a gap 4 is provided between the rotor 2 and the generating line of the inner surface. A stator 6 has an uneven surface in which a large number of triangular recesses 5a and triangular protrusions 5b are connected in the circumferential direction.
The material to be ground is supplied into a grinding chamber formed between the rotor 2 and the stator 6, and the particles of the material to be ground are ground by the high speed rotation of the rotor 2.

In this process of crushing the particles of the object to be crushed, the particles of the object to be crushed are supplied from the object supply port 8 provided in the bottom plate of the lower casing 7 connected to the lower end of the stator 6, and are rotated together with the rotor 2 at high speed. Due to the airflow generated by the stirring blades 9 fixed on the lower surface of the rotor bottom plate,
It is raised along the inverted conical inner surface of the lower casing 7, sent into the crushing chamber between the rotor 2 and the stator 6, and crushed by the impact of the convex portion 1b of the rotor 2 rotating at high speed. At the same time, velocity energy is applied by the rotational force of the rotor 2 to cause the particles to collide with the stator 6 and to be crushed, and to be ground between the convex portion 1b of the rotor 2 and the convex portion 5b of the stator 6 to be further finely crushed. The rotor is carried upward by the upward spiral airflow generated by the high-speed rotation of the rotor 2, and sent into the upper casing 10 connected to the upper end of the stator 6, which rotates at high speed together with the rotor 2. The product is discharged from a product discharge port 12 provided in the tangential direction of the upper casing 10 by centrifugal blades 11 fixed to the upper surface of the upper plate.

By the way, in the above-mentioned pulverizer, since the gap 4 between the rotor 2 and the stator 6 is generally 2 to 5 mm or more and wide, (a) the vortex generated in the recess 5a of the stator 6 is strength is weak.

(b) The probability of collision of particles of the object to be crushed with the rotor 2 is small.

(c) The impact force of the rotor 2 on the particles to be crushed is small.

There were other drawbacks.

In addition, in the crushing chamber between the rotor 2 and the stator 6, air passes through the recess 1a of the rotor 2, the gap 4, and the recess 5a of the stator 6, and the particles of the object to be crushed are They pass through the grinding chamber riding on the spiral airflow, but since the rotor 2 is rotating at high speed, almost no particles of the object to be ground pass through the recesses 1a of the rotor 2. Therefore, the particles to be crushed pass through two places: the gap 4 and the recess 5a of the stator 6. However, in the recess 5b of the stator 6, the third
As shown in the figure, the air flows from below to above while forming a vortex with high rotational speed. Among the particles of the material to be crushed that are caught up in this vortex, some collide with the wall surface of the recess 5a, are discharged from the recess 5a into the gap 4, are subjected to a strong impact action by the projection 1b of the rotor 2, and are fixed. Grinding progresses due to the grinding action of the child 6 with the convex portion 5b.

However, there is a drawback in that some of the particles to be crushed are not crushed as described above, but remain caught up in the vortex and exit from the crushing chamber through the upper end of the recess 5a.

In order to solve these drawbacks, a fine pulverizer was developed in which a classification ring 13 is integrally or removably provided on the inner circumferential surface of the upper end of the stator 6 to close the recess 5a, as shown in FIG. The pulverizer had the following drawbacks.

(a) Considering the difference in the concentration of the particles to be crushed in the vertical direction of the concave portion 5a of the stator 6, the concentration increases from the bottom to the top, and the concentration is lower toward the bottom.

(b) Therefore, in the lower part, there is little collision between the particles of the material to be crushed, and there is little crushing action.

The present invention improves the conventional pulverizer in order to eliminate such drawbacks, and repeats pulverization and classification for all particles of the material to be pulverized that pass through the pulverization chamber between the rotor and the stator. It is an object of the present invention to provide a pulverizer that can reliably and sufficiently perform pulverizing action to increase pulverizing efficiency and obtain pulverized products with a narrow particle size range of the order of microns or more than 10 microns.

The pulverizer according to the present invention will be explained below with reference to FIGS. 5 and 6. Since the same reference numerals in the figure as in FIGS. 1 and 2 indicate the same parts, the explanation thereof will be omitted.
The dimension of the gap 4 between the convex portion 1b of the rotor 2 and the convex portion 5b of the stator 6 is 1 mm or less. In this example, there are a plurality of horizontal annular grooves 15 in the vertical direction of the uneven surface of the outer surface of the rotor 2, with an appropriate gap and each having a bottom diameter smaller than the outer diameter of the recess 1a of the rotor 2. There are two. In the vertical direction of the uneven surface of the inner surface of the stator 6, a classification ring 16 whose inner diameter is smaller than the outer diameter of the concave portion 1a of the rotor 2 and larger than the diameter of the bottom of the annular groove 15 is installed in the gap between the annular grooves 15. A plurality of classification rings 16, three in this example, are removably provided. A labyrinth passage 17 is formed between the two. The classification ring 16 is removably fixed between the upper casing 10 and the divided stators 6a, 6b, 6c which are divided into three in the vertical direction as shown in the figure, by tightening the respective outer flanges.

Note that the centrifugal blades on the upper surface of the upper plate of the rotor 2 have been removed.

The pulverizer of the present invention configured as described above supplies particles of the pulverized material from the pulverized material supply port 8 provided in the bottom plate of the lower casing 7 connected to the lower end of the stator 6, and is integrated with the rotor 2. By the airflow generated by the stirring blades 9 rotating at high speed, the powder is raised along the inverted conical inner surface of the lower casing 7 and fed into the grinding chamber formed between the rotor 2 and the stator 6. ,
The particles to be crushed are crushed and classified multiple times in the crushing chamber.
In this example, the process is repeated three times and all of the products are finely pulverized, resulting in a finely pulverized product with a narrow particle size range of micron order or tens of microns, which is then sent into the upper casing 10 and placed in the tangential direction of the upper casing 10. It is discharged from the discharge port 12.

Now, details of the pulverizing action of the particles to be pulverized in the pulverizing chamber will be explained.

The particles of the object to be crushed that have entered the crushing chamber are crushed by the impact of the convex portion 1b of the rotor 2 rotating at high speed, and are given velocity energy by the rotational force of the rotor 2 and collide with the stator 6. The convex portion 1b of the rotor 2 and the convex portion 5b of the stator 6 are
It is further ground into fine particles.

In this crushing action, since the gap 4 between the convex part 1b of the rotor 2 and the convex part 5b of the stator 6 is as narrow as 1 mm or less, the strength of the vortex generated in the concave part 5a of the stator 6 is strong. The probability of collision of the particles of the object to be crushed with the rotor 2 is high, and the impact force of the collision of the particles of the object to be crushed by the rotor 2 with respect to the particles of the object to be crushed is large. Therefore, efficient grinding is performed.

The pulverized products thus pulverized are carried upward on the upward spiral airflow generated by the high-speed rotation of the rotor 2.
Since the gap 4 between the convex portion 5b of the rotor 2 and the convex portion 1b of the rotor 2 and the concave portion 1a of the rotor 2 are closed by the lower classifying ring 16, the ascending of the crushed products is prevented by the classifying ring 16. .

Therefore, the lower classification ring 16 for the particles to be crushed
As the residence time in the lower grinding zone becomes longer, the concentration of the particles to be ground becomes higher. As the residence time increases, the probability of receiving the crushing action increases accordingly, and a finer powder product can be obtained. Furthermore, when the concentration of the particles of the object to be crushed increases, the probability of collision between the particles of the object to be crushed increases, and the crushing action is promoted. Due to these two effects, the finely pulverized particles are reliably pulverized. The finely pulverized material rides on the airflow and rises to just below the classification ring 16.
Furthermore, it tries to rise through the labyrinth passage 17 between the classification ring 16 and the annular groove 15, but since the centrifugal force due to the rotation of the rotor 2 is acting directly under the classification ring 16, the Particles cannot pass through the labyrinth passage 17. Therefore, the pulverized product remains in the pulverization zone below the lower classification ring 16 for a long time and is sufficiently pulverized before it can pass through the labyrinth passage 17 together with air. The crushed products that have been classified by the classification ring 16, passed through the labyrinth passage 17, and entered the crushing zone between the middle classification ring 16 and the lower classification ring 16, stay there again for a long time in the middle stage. The particles are pulverized sufficiently to pass through the labyrinth passage 17 between the classification ring 16 and the annular groove 15. The crushed products are classified by the middle classification ring 16, pass through the labyrinth passage 17, and enter the crushing zone between the upper classification ring 16 and the middle classification ring 16, where they remain for a long time as before. It is sufficiently finely pulverized to pass through the labyrinth passage 17 between the upper classification ring 16 and the annular groove 15, is classified by the upper classification ring 16, passes through the labyrinth passage 17, and is sent into the upper casing 10.

In this way, the particles of the material to be crushed are
3 divided by middle and lower classification rings 16
Since pulverization and classification are repeated in the pulverization zone of the stage and the entire product is finely pulverized, what is sent into the upper casing 10 is a finely pulverized product with a narrow particle size range of micron order or tens of microns.

As detailed above, according to the pulverizer of the present invention,
All the particles of the material to be crushed passing through the crushing chamber between the rotor and the stator from the bottom to the top can be reliably and efficiently finely pulverized,
Since it is possible to easily obtain finely pulverized products with a narrow particle size range of micron order or tens of microns, it can be said to be an epoch-making device that can replace conventional pulverizers.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view of a conventional pulverizer, Figure 2 is a sectional view taken along the line - in Figure 1, and Figure 3 is a recess in the inner surface of the stator of the pulverizer in Figure 1. FIG. 4 is a partial perspective view showing the flow of air; FIG. 4 is a partial vertical perspective view showing a classification ring provided on the inner peripheral surface of the upper end of the stator in a conventional pulverizer; and FIG. 5 is a pulverizer according to the present invention. A vertical cross-sectional view of the machine, FIG. 6, is a cross-sectional view taken along the line -- in FIG. 1a... recess, 1b... protrusion, 2... rotor, 3... vertical rotating shaft, 4... gap, 5a... recess, 5b... protrusion,
6... Stator, 15... Annular groove, 16... Classifying ring,
17...Labyrinth passage.

Claims (1)

[Claims] 1 A rotor supported by a vertical rotating shaft and having a large number of rectangular concave portions and convex portions arranged circumferentially along the generatrix on the outer surface, and a rotor fitted with a gap between the rotor and the inner surface. In a vertical crusher that crushes a material to be crushed between a stator having a number of triangular concave portions and convex portions connected in the circumferential direction along the generatrix, the convex portions of the rotor and the convex portions of the stator are used. With a gap of 1 mm or less, a plurality of horizontal annular grooves having bottom diameters smaller than the outer diameter of the concave portion of the rotor are provided on the outer surface of the rotor at appropriate intervals in the vertical direction, and the stator is A plurality of classification rings having inner diameters smaller than the outer diameter of the concave portion of the rotor and larger than the diameter of the bottom of the annular groove are removably provided in the vertical direction on the inner surface of the rotor with a gap between the annular grooves; A pulverizer characterized in that a classification ring other than the classification ring is fitted into an annular groove to form a labyrinth passage between the two.