JPS591742Y2 - Powder classification device - Google Patents

Description

[Detailed description of the invention] The present invention is a method of separating powder and granules into desired particle size ranges and in multiple stages by placing powder and granules in an air stream and applying centrifugal force and centripetal force at the same time. This invention relates to a multi-stage classification device.

Conventionally, there are various classification devices of this type that utilize wind power.For example, the classification device shown in Japanese Patent Publication No. 34-1284 generally separates the materials to be sorted (hereinafter simply referred to as materials) with airflow. The airflow is introduced into the classifier, and centrifugal force is applied by the classification impeller rotating within the classifier, while the airflow is discharged outside the machine via the inside of the classification impeller. The materials inside are separated and sorted into two stages, coarse powder and fine powder, by the difference in action between centrifugal force and centripetal force applied at the same time.

However, for example, there are three stages: coarse powder, medium powder, and fine powder.
Conventionally, there has been no apparatus that can continuously perform multi-stage classification.

Therefore, in the past, the method used was to collect the once-classified fine powder or coarse powder using a device that classifies them into fine powder and coarse powder, and then send them to another classifier for classification.

However, in these methods, the number of operation units overlaps, resulting in an increase in the size of the entire device, which necessitates an increase in invested capital and working capital.

On the other hand, making continuous multi-stage classification possible facilitates miniaturization of the entire device, allows continuous operation with just one setting adjustment, and greatly simplifies the unit of operation. It is noteworthy.

By the way, as a conventional example of such a multistage classifier, there is a centrifugal classifier disclosed in Japanese Patent Publication No. 49-6248, for example.

However, since this device does not have a rotating classification blade, a sufficient dispersion effect cannot be expected for materials that are in an agglomerated state or materials that are likely to agglomerate, such as fine powder, and material particles may not be made into single particles. It ends up circling around the classification room forever.

Therefore, when supplying the material, the concentration of the material must be lowered relative to the amount of air introduced to prevent agglomeration, and the amount of material supplied is limited and cannot be increased.

This means that even if the classification accuracy is good for a classification device and the quality of the product is good, the operating cost for the product is extremely high, which is a problem when used industrially.

In contrast, the present invention provides excellent multi-stage classification that satisfies both classification accuracy and throughput performance by using the classification apparatus described in JP-A-55-73376 and JP-A-55-79021. The purpose is to provide equipment.

Next, the configuration of the present invention will be explained using examples.

In Fig. 1, 1a is a first classifier, and 1b is a second classifier.These classifiers 1a and lb supply the material to the fine powder outlet of the first classifier 1a, and Further, the fine powder discharge port of the second classifier 1a is communicated with the windmill 18 via the collector 17.

Note that various types of collectors such as a cyclone collector and a bag filter can be used as the collector 17.

In addition, in this example, there are two classifiers, LA and LB, and the material is classified into three stages, but the number of classifiers is not limited and can be set to any number of stages. be.

Accordingly, the amount of air introduced into the classifier and the rotational speed of the classification impeller are adjusted and set to optimal conditions.

Note that 20 is a control valve for adjusting the air volume.

Next, FIG. 2 shows another embodiment, in which the first classifier 1a and the second classifier 1b are connected via a solid-gas separator 19. The separated material is supplied to the second classifier 1b, while the discharged gas is supplied to the control valve 20,
The air is exhausted through the windmill 18 or introduced into the second classifier 1b as an airflow source.

In addition, when the solid-gas separator 19 and the second classifier 1b are connected, various supply devices (not shown) are provided as necessary.

The second classifier 1b is configured with a collector 1 as in the previous embodiment.
It is connected to a wind turbine 18 via 7.

Next, the classifier used in the present invention will be explained with reference to FIGS. 3 and 4.

Reference numeral 1 denotes the main body of the classifier, and the upper part of the machine side includes a fine powder discharge port 4, a classification impeller 2 rotatably supported by a rotating shaft 3, and whose rotating outer peripheral surface forms an inverted conical shape, and the classification impeller 2. A ventilation member 7 is provided, which surrounds the classification impeller 2, has an appropriate distance from the classification impeller 2, and has an inlet 12 opening in the form of a slit toward the downstream side in the rotational direction of the classification impeller 2. An air chamber 8 is formed between the ventilation member 7 and the machine-side inner wall surface 13 of the main body 1, and a primary gas population 9 is disposed in communication with the air chamber 8.

Further, an inner interlayer space 1 of the ventilation member 7 is provided on the machine side of the main body 1.
A material supply port 6 communicating with the classification impeller 2 is disposed, and the opening of the supply port 6 is provided toward the downstream side in the rotational direction of the classification impeller 2.

The supply port 6 can be connected to a screw feeder (not shown), an ejector set supply device, and various other supply devices.

In this embodiment, the supply port 6 is provided on the machine side of the main body 1 and toward the downstream side in the rotational direction of the classification impeller 2, but the supply port 6 is provided with an opening facing the inner interlayer space 14 of the ventilation member 7. If so, the installation position is not limited to the machine side, for example, from above the main body 1 shown in the figure, or from above the main body 1.
The arrangement position and the opening direction are determined in consideration of the characteristics of the supply device, such as the supply device being arranged from the outer periphery toward the axial center.

In addition, in this embodiment, the ventilation member 7 is a flat blade-shaped member that maintains a constant gap and is tilted toward the lower side in the rotational direction of the classification impeller 2 as shown in the figure. Although the blade-like members are arranged and configured to overlap with each other, the blade-like members may be formed into a curved surface along a streamline, or the blade-like members may be formed with holes inclined in the rotation direction of the classification impeller 2. For example, it can also be applied to a punch plate.

The point is that the openings of the small holes are relatively uniform along the inner peripheral surface of the ventilation member 7 in a direction that is inclined toward the lower side in the rotational direction of the classification impeller 2 or in a direction close to the inner peripheral surface line of the ventilation member 7. It is sufficient if they are distributed and arranged.

Further, in this embodiment, the classification impeller 2 is structured such that its outer peripheral surface forms an inverted conical shape when rotating, and accordingly, the ventilation member 7 is also shaped to follow the classification impeller 2. The present invention can also be implemented using a combination of various shapes, such as using a classification impeller 2 of other shapes or providing the ventilation member 7 in a cylindrical shape.

Further, the air chamber 8 is partitioned by a partition wall 15, and the air chamber 8a,
8b, and in response to this, each has a primary gas population of 9.
a, 9 b, but the number is not particularly limited to two.

In contrast to the structure of the machine side upper part described above, there is a coarse powder discharge port 5 at the bottom for taking out the sorted coarse powder side particles to the outside of the machine, and a gas outlet for the purpose of wind sieving the material transferred to the coarse powder side. A secondary gas population 10 for introducing gas, and a wind sieve ring 11 which is disposed continuously with the ventilation member 7 and forms a wind sieve section are provided.

Incidentally, various airtight on-off valves such as the rotary valve 16 can be connected to the coarse powder outlet 5.

Further, the secondary gas populations 9a, 9b and the secondary gas population 10 are aligned with the rotation direction of the classification impeller 2, and the main body 1
The ventilation member 7 is opened in the tangential direction to the machine side.
The purpose is to make the flow of air passing through the air sieve ring 11 uniform and stable, but in the case of the present invention, the opening direction is not particularly limited.

With the above configuration, in the first classifier 1a, the incoming airflow i introduced from the primary gas populations 9a, 9b through the ventilation member 7 into the inner circumferential concave space 14 of the ventilation member 7 through the inflow port 12 is classified. When the impeller 2 rotates in the direction of the arrow in the figure, it collides with and merges with the swirling airflow that accompanies the rotation, and is sucked inside the classification impeller 2 while being given a swirling motion, and is exhausted to the outside of the machine from the fine powder discharge port 4.

Under these conditions, the material fed into the inner concave space 14 from the material supply port 6 by the supply device is swirled by the swirling airflow, stirred by the collision between the swirling airflow and the inflowing airflow i, and stirred by the merging. As a result, the particles are dispersed and made into single particles, and are simultaneously subjected to a centrifugal force F due to the rotation of the classification impeller 2 and a centripetal force K due to the airflow J toward the center of the classification impeller 2. By adjusting the rotational speed of the airflow j and the airflow velocity of the airflow j toward the center of the classification impeller 2 to predetermined values, a desired sorting action is imparted to the material particles, and the centripetal force is influenced by the sorting action. The fine particles having a large size are sucked into the center of the classification impeller 2 along with the airflow j, and are discharged from the fine powder outlet 4 to the outside of the machine.

On the other hand, the centrifugal force F is larger, and the coarse particles move to the outer periphery of the rotation and reach the inner circumferential wall of the ventilation member 7.

Here, the coarse particles are again introduced from the primary gas populations 9a and 9b in addition to the swirling airflow caused by the rotation of the classification impeller 2.
The dispersion effect of the incoming airflow i blown from the inflow port 12 provided in the ventilation member 7 along the inner peripheral surface of the ventilation member 7 is greatly enhanced, and after being rapidly dispersed, the outer peripheral portion of the classification impeller 2 , and sorting is performed again.

In other words, the inflowing airflow i passing through the inflow port 12 has an extremely high velocity, and is evenly blown in from the entire circumference.
Upon collision and merging with the swirling airflow caused by the rotation of the classification impeller 2, a significant agitation effect occurs, so that the material in the airflow is very efficiently dispersed and made into single particles, giving it a sorting effect.

After being subjected to such repeated selection effects,
Note that the fine particles adhering to and mixed with the coarse particles descend while swirling along the inner circumferential wall surface of the ventilation member 7 together with the coarse particles, but when passing through the air sieve ring 11, the secondary gas population 10 Under the wind sieving effect of the introduced wind sieve air stream e and the accompanying dispersion and sorting effects, the particles are separated from the coarse powder side particles, and transferred to the outer periphery of the classification impeller 2 along with the wind sieve air stream e, where the sorting effect occurs. After being given this, the powder passes through the classification impeller 2 and is discharged from the fine powder outlet 4 to the outside of the machine.

On the other hand, the coarse particles pass through the wind sieve ring 11, fall, and collect at the coarse powder discharge port 5, where they are discharged and collected outside the machine by the rotary valve 16.

The material thus supplied to the present classifier 1a is repeatedly subjected to dispersing action and sorting action, thereby providing many opportunities for classification for each particle.

In this way, the material is separated and collected into fine particles and coarse particles, and here the fine particles are carried out along with the airflow from the fine powder outlet 4 of the classifier 1a, and are carried out in the next step in the finer particle area. Second classifier 1 set to obtain the desired classified particle size
The material b is supplied into the second classifier 1b to be subjected to a classification action.

Then, the particles are again subjected to the same action in the first classifier 1a as described above, and after being sorted and separated into fine particles and coarse particles, the coarse particles are discharged outside the machine and captured. On the other hand, the particles on the fine powder side are discharged to the outside of the machine along with the airflow,
The air is transferred to, separated from, and collected by the airflow, and the airflow is exhausted into the atmosphere via the wind turbine 18.

In the embodiment shown in FIG.
9, and after being separated from gas, it is sent into the second classifier 1b.

The same effect as in the above-mentioned embodiment is provided, and the air is separated and collected, but by separating the fine powder particles and air by disposing the solid-gas separator 19, the air volume in the second classifier 1b is This allows easy operation from the adjustment aspect.

As described above, according to the present invention, it is possible to perform stable multi-stage classification continuously, obtain any multi-stage classified product, and each classifier can be installed in series on one line. The present invention has great effects, such as the miniaturization of the entire device including its power, the simplification of the unit of operation of the device, and the reduction of both equipment and operating costs, which are economically advantageous.

In addition, (by classifying the material to be sorted into multiple stages, it is possible to limit and accurately maintain the particle size distribution range of the sorted products separated at each stage, and the quality of the sorted products can be improved. become.

For example, in the first example, in a device that is equipped with two classifiers and one collector to classify into three stages, when this device is used to classify coarse powder, the coarse powder in the classifier in the Medium powder is obtained from the classifier, and fine powder is obtained from the third stage collector.

By appropriately adjusting and setting the second-stage classifier, if the coarse powder and fine powder obtained in the first-stage classifier and third-stage collector are to be used as products, both have intermediate particle sizes. Good quality particles with uniform particle size can be obtained.

In other words, in general, the first stage coarse powder contains intermediate particles similar to the second stage medium powder, and the second stage medium powder contains coarse powder particles similar to the first stage as well as the third stage. Similarly, in the fine powder particles of the third stage, intermediate particles similar to the medium powder of the second stage are mixed, albeit slightly.

However, if we look at the coarse powder in the first stage and the fine powder in the third stage, we can see that there are fine powder particles in the third stage in the coarse powder in the first stage, or coarse powder particles in the first stage in the fine powder in the third stage. The proportions of each of these components are extremely small, and both coarse and fine powders are of good quality and have no intermediate grains and have uniform particle sizes.

Further developing this point, we performed multi-stage classification using a device in which any number of classifiers were connected, and the amount collected at each stage was divided into 2, 4, 6.8, etc. 1, 3, 5, 7.9・
By performing operations such as making the collected amount of odd-numbered stages the product, or vice versa, it is possible to obtain high-quality multi-stage products with extremely uniform particle size in terms of the collected amount. A classified product can be obtained as a continuous operation.

As a second example, in a device in which two classifiers and a collector are connected, by appropriately adjusting and setting the second stage classifier, as in the above example, fine powder can be divided into coarse powder or fine powder. This reduces the amount of coarse powder mixed in with the
In particular, since a two-stage sorting action is imparted to fine powder particles, the mixing of coarse powder into fine powder can be significantly reduced.

Therefore, when trying to obtain only fine powder as a product, the first step is to set the first stage classifier to lower the recovery rate of coarse powder to some extent, but first improve the recovery rate of fine powder. Next, the fine particles sorted by the first-stage classifier are classified again, thereby completely separating and eliminating the coarse particles mixed in with the fine powder, and continuously producing high-quality fine powder products with even more uniform particle size. It can be obtained efficiently.

The operations detailed above can efficiently produce high-quality, multi-stage classified products in a continuous manner, and can also be applied to cases where the throughput is relatively large, or to classify materials that have traditionally been considered difficult to classify. It is effective because it can be expanded.

[Brief explanation of the drawing]

Fig. 1 is a flow sheet showing an outline of an embodiment of the present invention, Fig. 2 is a flow sheet showing an outline of another embodiment, Fig. 3 is a sectional view of main parts of a classifier, and Fig. 4 is a flow sheet showing an outline of another embodiment. AA' sectional view,
FIG. 5 is an enlarged view of part B in FIG. 4. In the figure: 1...Main body, 2...Classifying impeller, 4...Fine powder outlet, 5...Coarse powder outlet, 6... ...Raw material supply port, 7...
Ventilation member, 8...air chamber, 9...primary gas inlet, 12...inflow port, 13...machine side inner wall surface, 14... ...inner interlayer space, 19...
...It is a solid-gas separator.

Claims (2)

[Scope of utility model registration request] (1) A classification impeller 2 rotatably provided in the main body 1 having a fine powder discharge port 4, a coarse powder discharge port 5, and a supply port 6 for material to be sorted is rotated, and the separated fine powder particles are transferred to the classification impeller 2. The classifier is configured so that the fine powder particles are sucked into the inside of the 2, and the fine powder particles are discharged from the fine powder discharge port 4 and the coarse powder particles are discharged from the coarse powder discharge port 5, respectively. A ventilation member 7 having a large number of inlets 12 surrounding the classification impeller 2 and opening toward the downstream side in the rotational direction is disposed, and the ventilation member 7 allows air flow inside the machine side of the main body 1. An air chamber 8 is formed between the air chamber 8 and the wall surface 13, and a supply port is opened to communicate with the air chamber 8 and face the primary gas population 9 and the inner interlayer space 14 formed between the inner layers of the ventilation member 7. In addition to arranging a plurality of classifiers configured by respectively arranging the classifiers 1a, lb...
A particle classification device characterized in that the fine powder discharge port 4 and the supply port 6 of each of the... are successively connected. (2) The apparatus for classifying powder and granular material according to claim 1 of the registered utility model claim, characterized in that a solid-gas separator 19 is disposed between the fine powder discharge port 4 and the supply port 6. .