JPH0434464B2 - - 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 powder have the problem that separation performance deteriorates rapidly as the size increases. Be looked at. 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 returned to the factory and ground again, impairing the classification efficiency (arrow in Fig. 3). Especially in the cement industry,
This system has the disadvantage that the classification chamber must be made smaller, which reduces the amount of circulating air in the classification chamber, reduces the amount of grinding, and reduces the grinding 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. As a result, the object is achieved by providing a current plate on the classification blade to reduce the above b/a to 1/10 or less, and more preferably to reduce d/c to 1/10 or less, and the present invention 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 mounting 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 receive a larger centrifugal force than the fine particles, so they reach the side wall of the classification chamber 1 and settle along the side wall due to gravity, but the fine particles that do not reach the side wall are relatively coarse. The particles are separated by rotating classification vanes 4 and settle along the side walls in the same way as 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 attached radially to the classification blade mounting plate 3 are attached so that they protrude outward from the classification blade mounting plate 3, and the length b of the protruding portion is the width of the classification blade 4. (b/a) is set to less than 1/10 of a. Further, a current plate 5 is provided horizontally on the classification blade 4 (FIG. 2). The number of current plates 5 is not limited to one, and a plurality of plates may be provided. When there is only one rectifier plate 5, it is preferable to provide the rectifier plate approximately in the middle of the height of the classification blade 4. As a result, the airflow flows into the swirling region of the classification blades more horizontally than in the past, improving classification efficiency. However, in order to further improve this effect, the relationship d/c<1/10 is satisfied between the height c of the classification blade 4 and the distance d between the upper side of the classification blade and the upper wall 6 of the classification chamber. This is achieved by adjusting the height of the classification blade or the height of the upper wall 6 of the classification chamber so as to achieve this. The air separator of the present invention is a Sturtevant type,
Applicable to cyclone type air separators, etc. [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 also 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 the attachment of the classification blades in a conventional air separator. 1... Classifying chamber, 2... Dispersion plate, 3... Classifying blade mounting plate, 4... Classifying blade, 5... Rectifying plate, 6...
Upper wall of classification chamber, 7...input port, 8...shaft.

Claims (1)

[Claims] 1. In an air separator having a vertical axis rotatably supported at the center of the classification chamber, a dispersion plate, a classification blade mounting plate, and a classification blade that rotate integrally, the classification blade is When installing the classification blade on the blade mounting plate, the length of the part of the classification blade that protrudes outside the mounting plate must be 1/10 or less of the width of the classification blade, and a rectifier plate must be installed horizontally on the classification blade. An air separator featuring: 2. In an air separator having a vertical shaft rotatably supported at the center of the classification chamber, a dispersion plate, a classification blade mounting plate, and a classification blade that rotate integrally, the classification blade is attached to the classification blade mounting plate. The length of the part of the classification blade protruding outward from the mounting plate is 1/10 or less of the width of the classification blade, and a rectifying plate is provided horizontally on the classification blade, and the upper side of the classification blade is An air separator characterized in that the distance between the classification blade and the upper wall of the classification chamber is 1/10 or less of the height of the classification blade.