JPH1028890A - Vertical roller mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the revolving force in a mill and to enhance classifying accuracy in a vertical roll mill grinding coal, cement, and the like. SOLUTION: Matter 1 to be ground falls on the table 8 rotated within a mill from a supply pipe 2 to be moved to the lower part of a roller 7 by centrifugal force to become ground matter 4 and this ground matter 4 is fed to a separator 5 by hot air supplied from a plurality of blow-up blocks obliquely attached to the inner wall of the mill and a primary classifying block 9 to be classified into a fine powder and a coarse powder and the fine powder is supplied to a finely ground matter outlet while the coarse powder again falls on the table 8 to be again ground. By arranging hot air guide fins 11 to the rear surface of the primary classifying block 9 so as to continue to the extension lines of the blow-up blocks 10, revolving force is increased and primary classification is accelerated and the amt. of the coarse particles reaching the separator 5 is reduced and classifying capacity is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical roller mill for pulverizing coal, cement raw material and the like.

[0002]

2. Description of the Related Art FIG. 5 is a longitudinal sectional view of a conventional vertical roller mill, FIG. 6 is a view taken along a line CC in FIG. 5, and FIG. 7 is a view taken along a line DD in FIG. In these figures, 1 is a material to be crushed such as a raw material of coal or cement, 2 is a supply pipe for a material to be crushed, 3 is a crushed material outlet pipe, 4 is crushed material, 5 is a separator, 6 is hot air, 7 is A roller 8, a table, and a primary classification block 9 are provided at three locations in the circumferential direction as shown in FIG. Reference numeral 10 denotes a blow-up block provided at a lower portion of the primary classification block 10.

[0003] In the vertical roller mill having the above-described configuration, the material 1 to be crushed, such as coal or cement raw material, is carried onto the table 8 through the material supply pipe 2. The object 1 to be crushed carried on the table 8 is moved to the lower part of the roller 7 by the centrifugal force of the rotating table 8 and crushed.

[0004] The pulverized material 4 is classified by the blowing and blowing of hot air 6 for drying and conveying supplied through a blow-up block 10 and a primary classifying block 9 attached to the inner wall of a roller mill at the outer edge of the table 8, and is conveyed by air flow. enter. By the rotation of the separator 5, the powder is further classified into fine powder and coarse powder, the fine powder is conveyed to the pulverized material outlet pipe 3, the coarse powder again falls on the table 8, and is re-pulverized as described above.

[0005]

In the above-mentioned conventional vertical roller mill, the object 1 to be ground is a rotating table 8.
Is moved under the roller 7 by the centrifugal force, and the pulverized material 4 is conveyed to the separator 5 by the hot air 6. However, the following primary classification is performed until the pulverized material 1 reaches the separator 5. Done.

[0006] (1) Primary classification at the airflow blow-up portion at the outer edge of the table 8, and (2) Fine particles in the material 1 when the material 1 falls from the material supply pipe 2 onto the table 8. Classification by the air current is performed.
(2) If the classification effect is increased in the portion, the separator 5
It is possible to reduce the amount of coarse particles mixed into the pulverized material after passing.

As described above, according to the present invention, in a conventional vertical roller mill, the classifying effect in the above-mentioned parts (1) and (2) is enhanced to reduce the amount of coarse particles reaching the separator, whereby the separator It is an object of the present invention to provide a vertical roller mill having improved classification performance.

[0008]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a table rotating around a vertical drive shaft inside a mill body, and a plurality of rollers pressed and rotated on the upper surface of the table to crush the material to be crushed. Having a primary classification block and a primary classification block for drying the crushed material from the lower part of the mill main body and guiding hot air for conveyance into the mill main body, provided near the inner wall of the mill main body facing the outer edge of the table. A vertical roller mill having a blow-up block provided at a lower portion, wherein a hot air guide fin is provided on a lower surface of the primary classification block so as to be continuous with the blow-up block.

According to the present invention, the hot air is first blown from the lower part of the mill body to the blow-up block by the above means. The blow-up block, for example, is attached to the inner wall of the mill body at regular intervals and at an angle of about 45 °, and is further guided to the primary classification block from the blow-up block. Since the hot air guide fins are continuously provided in a protruding manner, the blowing direction of the hot air is continuously guided, shaped, and blown upward with the rotation of the table taken into account. The swirling effect of the swirling flow in the crushing chamber) is enhanced.

As described above, the primary classification of the pulverized material moving from the table top to the separator is accelerated by the increase of the swirling flow effect. In addition, an air swept effect can be appropriately exerted on the object to be crushed held in the crushing table. As described above, the primary classifying effect inside the mill (pulverizing chamber) is most effective in the swirling flow.

[0011]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a vertical roller mill according to an embodiment of the present invention,
2 is a view taken along the line AA in FIG. 1, FIG. 3 is a view taken along the line BB in FIG. 1, and FIG. 4 is an enlarged view of the primary classification block.

In these figures, reference numerals 1 to 10 correspond to those in FIG.
Since the members have the same functions as those of the related art described above, they will be described by quoting them as they are, and detailed descriptions thereof will be omitted. Hereinafter, the characteristic portions of the present invention will be described in detail.

In these figures, the primary classifying blocks 9 are provided at three places in the figures, and fins 11 for guiding hot air are attached to the lower surface of each block 9 by protruding continuously on an extension of the blow-up block 10. The blow-up block 10 is attached at a plurality of angles of 40 to 55 ° so as to guide hot air in a direction opposite to the rotation direction of the table 8, and the hot air guide fins 11 are attached as shown in FIG. On its extension.

The height of the hot air guide fins 11 is set to a size in the range of about 30 to 50% of the height of the blow-up block 10. Air Swept (Air Swept)
(Swept) action is so large that the crushed material 1 held on the table 8 is blown off, so that the carbon layer becomes uneven. Also 20%
The effect decreases when:

As described above, the fins 11 for guiding the hot air to the primary classification block 9 have an angle range of 40 to 45 ° and are provided in a height range of 30 to 50% of the height of the blow-up block 10, so that the hot air 6, the rotation of the table 8 is taken into account, and the turning force inside the mill (crushing chamber) increases. Due to the increase in the swirling flow effect, the primary classification of the pulverized material 4 moving from the table 8 to the separator 5 is accelerated, and the pulverized material 1 held in the pulverization table 8 can exert an appropriate air swept effect.

[0016]

As described above, the present invention has a table rotating around an axis inside a mill main body and a plurality of rollers pressed against the table upper surface to guide hot air for drying and conveying. In the vertical roller mill having the primary classification block and the blow-up block, the configuration is such that the fins for guiding hot air are arranged continuously on the lower surface of the primary classification block and the blow-up block.

By increasing the swirling force of the hot air inside the mill (pulverizing chamber), the primary classification effect of the fine powder contained in the pulverized material and the material to be pulverized is increased, and the coarse particles reaching the separator can be reduced.

Therefore, the classification performance of the separator is also improved, and a pulverized product having a uniform particle size can be obtained.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a vertical roller mill according to an embodiment of the present invention.

FIG. 2 is a view taken in the direction of arrows AA in FIG.

FIG. 3 is a view taken in the direction of arrows BB in FIG. 1;

FIG. 4 is an enlarged view of a primary classification block in the vertical roller mill according to one embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of a conventional vertical roller mill.

FIG. 6 is a view as viewed in the direction of arrows CC in FIG. 5;

FIG. 7 is a view as seen in the direction of the arrow DD in FIG. 5;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 crushed material 2 crushed material supply pipe 3 crushed material outlet pipe 4 crushed material 5 separator 6 hot air 7 roller 8 table 9 primary classification block 10 blow-up block 11 hot air guide fin

Claims (1)

[Claims] 1. A table which rotates around a vertical drive shaft inside a mill body, and a plurality of rollers which are pressed and rotated on the upper surface of the table and crush the object to be crushed, and face an outer edge of the table. A vertical classifying block provided near the inner wall of the mill body, and having a primary classification block for guiding hot air for drying and conveying hot air from the lower portion of the mill body into the mill body, and a blow-up block provided at a lower portion of the block. A vertical roller mill, wherein a hot air guide fin is provided on a lower surface of the primary classification block continuously to the blow-up block.