JPH0434465B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to an air separator that can efficiently classify powder. [Prior Art] Air separators have been widely used in the cement industry, steel industry, chemical industry, etc. since ancient times as important equipment for improving the efficiency of the entire crushing plant. However, in recent years, the size of various equipment has increased, and this type of crushing department is no exception.
Therefore, the attached air separator is naturally required to be larger, but air separators based on the principle that centrifugal force in swirling airflow separates particles have the problem that separation performance deteriorates rapidly as they become larger. . In other words, in conventional air separators of this type, the position of the classification blade attached to the classification blade mounting plate protrudes greatly outward, and the relationship between the width a of the classification blade and the protrusion length b is b/a>0.5, and the position of the classification blade attached to the classification blade mounting plate is large. The relationship between the height c and the distance d between the upper side of the classification blade and the upper wall of the classification chamber is d/c>1 (third
figure). [Problem to be solved by the invention] For this reason, the airflow flowing into the rotating area of the classification blades cannot be made to flow horizontally to the classification blades. The particles were mixed into the coarse powder (returned powder) that was to be returned to the ground and ground again, impairing the classification efficiency (arrow in Fig. 3). Especially in the cement industry,
This method has the disadvantage that the size of the classification chamber must be made smaller, which reduces the amount of circulating air in the classification chamber, resulting in a reduction in the amount of pulverization and a reduction in the pulverization efficiency in terms of the Blaine value. SUMMARY OF THE INVENTION An object of the present invention is to provide an air separator which can eliminate the above-mentioned drawbacks, improve classification efficiency, and improve particle size structure particularly from the viewpoint of cement quality. [Means for Solving the Problems] In order to improve the classification efficiency, the present invention has made various studies on the relative position of the classification blade and the classification blade mounting plate so that the airflow flowing into the classification blade rotation area is as horizontal as possible. The results obtained show that the distance between the upper side of the classification blade and the upper wall of the classification chamber is 1/10 or less of the height of the classification blade, and that a rectifier plate is provided horizontally from the upper wall of the classification chamber toward the center. Thus, the object was achieved and the present invention was completed. The present invention will be explained using figures. FIG. 1 is a diagram showing the main part of the air separator, that is, the classification chamber. The rotation of the shaft 8 rotates the dispersion plate 2 and the classification blade attachment plate 3, and the powder to be classified that falls onto the dispersion plate 2 from the inlet 7 is dispersed by centrifugal force. At this time, the coarse particles are subjected to a larger centrifugal force than the fine particles, so they reach the side wall of the classification chamber and settle along the side wall due to gravity, but the fine particles that do not reach the side wall are relatively coarse particles. It is separated by the rotating classification blade 4 and settles along the side walls in the same way as the coarse particles. On the other hand, the fine particles from which the coarse particles have been separated ride the airflow and reach the upper part of the classification chamber, and the powder is thus classified. Here, the plurality of classification blades 4 mounted radially on the classification blade mounting plate 3 has a height c that is d/c< Make it 1/10. Further, a rectifying plate 5 is provided horizontally from the upper wall of the classification chamber toward the center (FIG. 2). The length of the current plate 5 is preferably such that the end of the classification blade on the center side is almost hidden. As a result, the airflow flows into the swirling region of the classification blades more horizontally than in the past, improving classification efficiency. The air separator of the present invention is suitably employed in cyclone type, stator bunt type, etc. air separators. Example Using a cyclone type air separator with a classification chamber diameter of 600 mm, cement was classified under the operating conditions shown in Table 1, and the obtained results are shown in the same table.

〔Effect of the invention〕

The present invention overcomes the deterioration in separation performance seen in recent large-sized air separators, improves classification efficiency, and improves the particle size structure that affects the quality of cement, etc. There are great economic benefits such as reduction in unit consumption, and the industrial benefits are extremely large.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the classification chamber of the air separator of the present invention, and FIG. 2 is a plan view showing the relative positions of the classification blades and the rectifying plate provided on the classification blade mounting plate. FIG. 3 is a sectional view of a classification vane attachment in a conventional air separator. DESCRIPTION OF SYMBOLS 1... Classifying chamber, 2... Dispersion plate, 3... Classifying blade mounting plate, 4... Classifying blade, 5... Rectifying plate, 6... Classifying chamber upper wall, 7... Input port, 8... Shaft.

Claims (1)

[Claims] 1. In an air separator having a dispersion plate, a classification blade mounting plate, and a classification blade that rotate integrally with a vertical shaft rotatably supported at the center of the classification chamber,
The air is characterized in that the distance between the upper side of the classification blade and the upper wall of the classification chamber is 1/10 or less of the height of the classification blade, and a rectifier plate is provided horizontally from the upper wall of the classification chamber toward the center. Separator.