JPH0116546Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a wind classifier, and more particularly to a mechanism for preventing powder from adhering to classification means such as a separator plate, a rectifier plate, a dispersion plate, and a classification blade of a wind classifier.

Conventional technology Conventionally, when classifying powder such as titanium white, magnesium hydroxide, electric furnace dust, kaolin, etc. using a wind classifier, the separator plate, rectifier plate, dispersion plate, and classification blade of the classifier were used. Powder adheres to the part of the classification means that comes into contact with the powder, affecting the shape and position of the classification means, resulting in a decline in classification performance, or in severe cases, part of the classifier becomes blocked, making classification impossible. A problem has arisen when this happens. In particular, the tip of the separation plate is required to have a sharp cutting edge, and adhesion of powder directly affects classification accuracy.

As a countermeasure, methods such as installing a shock absorber or the like in the classifier body to apply a shock, or heating the air flowing into the classifier to warm the powder have been taken, but these methods have not been sufficiently effective. . In addition, methods such as using materials such as Teflon for classifying means such as separation plates to which powders do not easily adhere have been taken, but these methods do not provide a fundamental solution, as problems arise due to wear in addition to adhesion. I can't say that.

The cause of powder adhesion is said to be cohesive force between particles or static electricity, but there is no established theory, and there are no effective measures to prevent adhesion.

For this reason, it has been said that it is impossible to classify highly adhesive powders using a wind classifier.
Chemical treatment or wet treatment methods are often used.

In recent years, research and development of new materials has become active, and there has been a strong demand for classification of highly adhesive powders using a wind classifier.

The inventor of this invention has conducted various studies on wind classifiers, and has found that the adhesion of powder is related to the wind speed, and that there is less adhesion in areas where the wind speed is low. It has been found that by covering the surface of the part that comes into contact with a thin layer of air, adhesion of powder can be prevented without affecting the classification performance.

Purpose The purpose of the present invention is to provide a wind classifier that can prevent powder from adhering to a classification means such as a separator plate without affecting classification performance.

Configuration In order to achieve the above object, the present invention includes an internal air passage and at least one air jet port in a classifying means for classifying powder carried by an air flow from a powder supply port. It is characterized by the fact that it is provided.

Hereinafter, embodiments will be described in detail based on drawings showing examples.

FIG. 1 is a side sectional view showing one embodiment of the wind classifier according to the present invention.

In the figure, powder raw material 4 is supplied into the classifier from a hopper 1 through a powder raw material supply port 3 by a powder supply device 2 such as a screw conveyor, and a high-speed air flow C is ejected from a tertiary air flow introduction port 5. Due to the bench lily effect (kirifuki effect), they are first gathered in a narrow area (range D). The powder particles in the powder raw material thus collected in a narrow area are given an inertial force by the high-speed airflow C, and flow in the direction of inertia (downward in the figure), and at the same time, from the primary airflow inlet 6. The powder is carried in the direction of the powder collection ports 8 and 9 by the airflow formed by the merging of the primary airflow A introduced by suction, the secondary airflow B and high-speed airflow C introduced by suction from the secondary airflow introduction port 7. . Since the above-mentioned inertial force differs depending on the particle size of the powder particles, the distribution of the powder particles in the airflow toward the powder particle collection ports 8 and 9 is as follows:
Fine particles with a small inertial force are located above, and coarse particles with a large inertial force are located below.

The first powder recovery port 8 and the second powder recovery port 9 are separated by a separation plate 10 that has a fulcrum on the downstream side of the airflow and is partially or entirely movable. Coarse particles are taken out from 8, and fine particles are taken out from a second powder collection port 9.

By appropriately selecting the shape of the separation plate 10 and the position of the tip, it is possible to perform a predetermined classification that corresponds to the properties of the powder raw material. However, when powder particles adhere to the separation plate 10, their shape and As described above, it is difficult to perform predetermined classification due to the influence on the position.

FIG. 2 is a cross-sectional view showing an example of a separating plate according to the present invention, and FIG. 3 is a perspective view thereof. The separation plate 10 is
It is attached to the main body of the classifier by a shaft (not shown) having an air introduction passage inside, which passes through the shaft hole 12 of the boss 11, and its position can be adjusted. The air introduction path of this shaft is an air inlet 1 that communicates from the shaft hole 12 of the boss 11 to the air passage 13.
Connects with 4.

Air sent from an air source device (not shown) to the air introduction path of the shaft passes through the air inlet 14 and enters the air passage 13 surrounded by the top plate 15, back plate 16, and side plate 17, and enters the separation plate 10. The air is ejected from an air outlet 18 provided at the tip, for example, the tip of the top plate 15.

In addition to the method described above, the air can be introduced into the air passage 13 by directly connecting a pipe, a hose, etc. to the side plate 17. Further, the air jet ports 18 are not limited to the illustrated slit shape, and the shape, position, number, air jet direction, etc. can be arbitrarily selected, and they can also be provided on the back plate 16.

The air ejected from the air outlet 18 passes through the powder recovery ports 8 and 9 while thinly covering the outer surfaces of the top plate 15 and the back plate 16, that is, the surface of the separation plate 10, along the air flow containing the powder particles. flows in the direction of The air layer covering the surface of the separator plate prevents the powder particles from coming into contact with the separator plate, thereby preventing powder from adhering to the separator plate, and also having the effect of preventing wear of the separator plate.

FIG. 4 is a side sectional view showing another embodiment of the wind classifier according to the present invention.

In the figure, the powder raw material to be classified enters the classification chamber 20 from the bottom of the figure along with the airflow, and is subjected to the action of centrifugal force due to the rotation of the classification rotor 21. Among the powder raw materials, the coarse powder is blown against the vessel wall and falls along the vessel wall, and the fine powder is separated from the coarse powder and passes through the upper discharge port 22.
It is discharged by air currents. Note that 23 indicates a shaft of the classification rotor 21, and 24 indicates a rotating portion of the shaft 23.

Similar to the separation plate described above, if powder adheres to the classification rotor 21, there is a risk that the operation cannot be continued due to deterioration of classification performance, generation of vibration, etc.

FIG. 5 is a perspective view showing an example of the classification rotor 21. The classification rotor 21 has a hollow structure with an air passage 25, and air jet ports 2 are provided at the tip and around the air passage 25.
It has 6. The shape, position, number, air jet direction, etc. of the air jet ports 26 can be selected as appropriate. The classification rotor 21 is attached to the shaft 23 through an air introduction passage (not shown) inside the shaft.
This is done so that the inside of the shaft and the air inlet 27 communicate with each other, but in addition, a pipe or a
It may also be connected directly with a hose or the like.

Air enters the air passage 25 from the air inlet 27 through the air inlet inside the shaft from an air source device (not shown) and is ejected from the air outlet 26, thinly covering the surface of the classification rotor 21 and causing powder to adhere to it. prevent.

Effects As described above, according to the present invention, it is possible to prevent powder from adhering to the classification means such as the separator plate, rectifier plate, and classification blade of the wind classifier, and the classification performance is maintained for a long period of time. Operational troubles can be prevented. Furthermore, it has great industrial effects, such as making it possible to classify powders that conventionally could not be applied using wind classifiers due to their high adhesion.

[Brief explanation of drawings]

Fig. 1 is a side sectional view showing one embodiment of the wind classifier according to the present invention, Fig. 2 is a sectional view showing an example of the separation plate of the wind classifier shown in Fig. 1, and Fig. 3 is the sectional view shown in Fig. 2. FIG. 4 is a side sectional view showing another embodiment of the wind classifier according to the present invention, and FIG. 5 is a perspective view showing an example of the classification rotor of the wind classifier shown in FIG. 4. It is. 3...Powder supply port, 10...Separation plate, 13,2
5... Air passage, 18, 26... Air outlet, 2
1... Classification rotor.

Claims (1)

[Claims for Utility Model Registration] Wind power classification which has a classifying means disposed in a flow path of powder supplied from a powder supply port and carried by an air flow, and which classifies the powder by the classifying means. The machine includes: an air passage provided inside the classification means; and an air outlet provided in the classification means and communicating with the air passage; Powder adhesion in a wind classifier, characterized in that an air layer is formed on the surface of the classification means by jetting out air and causing the jetted air to flow along the classification means using the airflow. Prevention mechanism.