JP2739750B2 - Vertical crusher - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The vertical mill according to the present invention relates to a vertical mill in which various ceramics and inorganic chemicals are finely pulverized in cooperation with a rotary table and a pulverizing roller. The present invention relates to a vertical pulverizer provided with a classification function for producing a product having a particle size distribution in which the proportion of coarse powder having a diameter larger than the diameter is reduced.

[0002]

2. Description of the Related Art As one type of crusher for finely pulverizing raw materials such as limestone, slag, and cement raw material into powder, FIG.
As shown in FIG. 1, a vertical pulverizer 1 having a rotary table and a pulverizing roller is widely used. This kind of crusher is
A disk-shaped rotary table 3A, which is driven by the speed reducer 2 by the constant speed motor 2K and is rotated at a low speed at the lower portion of the cylindrical casing 15, is pressed against a portion equally dividing the outer peripheral portion of the upper surface in the circumferential direction by hydraulic pressure or the like. And a plurality of crushing rollers 4 that are driven and rotated.

The crushing roller 4 has a rotating shaft 6
The arm 5 is pivotally supported by an arm 5 and is connected to a piston rod 10 of a hydraulic cylinder 9 via an arm 7. By operating the hydraulic cylinder 9, the grinding roller 4 is pressed onto the rotary table 3 </ b> A. To give the grinding pressure to the raw material. 3B is a dam ring provided on the outer peripheral edge of the rotary table 3A for adjusting the layer pressure of the raw material, 14 is an annular space passage for gas blowing around the rotary table 3A, 14A is a gas supply path, and 13 is a rotary shaft 13a via a stay 13b. A rotary separator for classifying the raw material pulverized by the blades 13c attached thereto, 16 is an outlet for taking out the product together with the gas, and 17 is a raw material input chute.

In such a vertical pulverizer, the raw material supplied to the center of the rotary table by the raw material charging chute 17 receives the centrifugal force in the table radial direction by the rotation of the rotary table 3A and slides on the rotary table 3A. When a force in the rotating direction is received by the rotating table 3A,
A slides with A and makes a rotation somewhat slower than the rotation speed of the turntable 3A. The above two forces, that is, the force in the radial direction and the force in the rotational direction are synthesized, and the raw material is
A moves to the outer periphery of the turntable 3A in a spiral locus on A. Since a roller is pressed against this outer peripheral portion and rotated, the raw material describing the spiral enters the crushing roller 4 and the rotary table 3A from a direction forming an angle with the roller axis direction and is caught. Rarely crushed.

On the other hand, a gas such as air or hot air is guided to the base of the casing 15 by a duct.
This gas blows up from the annular space 14 between the outer peripheral surface of the turntable 3A and the inner peripheral surface of the casing,
The pulverized fine powder rises inside the casing 15 together with the gas, and the blades 13c of the separator 13 located at the upper part
, A product having a predetermined particle size is discharged from the outlet 16 together with the gas and sent to the next step.

[0006]

When a raw material is pulverized by a conventional vertical pulverizer incorporating a rotary separator 13, for example, a vertical pulverizer as shown in FIG. The particle size distribution of the product obtained has the characteristic curves shown by solid lines in FIG. 5 (ie, curve A and curve B). However, depending on the type of product, it may be desirable to obtain a product having a particle size distribution in the state of curve C in FIG.
In addition, only those having a particle size distribution slightly shifted to the left from the curve B as they are can be obtained, and the desired curves A and C cannot be obtained. In another rotary separator 20 having rotating vanes 24 inside a fixed guide vane 22 as shown in FIG. 7, the rotation speed of the rotor 26 for controlling the classifying point can be changed although the guide vane 22 has a rectifying effect. Even if it is performed, the content ratio of only coarse powder larger than the average particle diameter Dm cannot be reduced.

[0007]

To solve the above-mentioned problems, it is possible to obtain a product having a particle size distribution in which the content ratio of only coarse powder having an average particle size or less is reduced while maintaining the particle size distribution of fine particles having an average particle size or less. Therefore, in the vertical pulverizer of the present invention, a plurality of rotatable pulverizing rollers are arranged on the outer peripheral upper surface of a rotatable table rotatable around a vertical axis, and the raw material supplied to the center of the rotatable table is rotated. In a vertical pulverizer that pulverizes between the upper surface and the peripheral surface of a pulverizing roller, classifying blades that have a vertical surface at the top of the pulverizer and that expand in diameter in the vertical or upward direction are arrayed in a plurality of equal circles. A rotary separator that is rotatably driven coaxially with the center of the rotary table, and a plurality of inclined paddles that extend radially at the lower end of the rotary shaft of the rotary separator and are arranged at equal circumferential intervals. rotating Jo inclined vanes To retreat from above the downwardly relative direction
Crusher high pre separators circumferentially provided by inclined so that
It was configured to be installed in the middle part .

[0008]

In the present invention, the fine powder of the raw material pulverized by the rotary table and the pulverizing roller is transported upward by the ascending airflow introduced into the annular space passage, and travels to the rotary separator but before flowing into the rotary separator. At the same time, it is pre-classified by the classifying action of the inclined blades of the sub-rotor, which rotates coaxially and integrally with the rotary separator in the direction that generates thrust downward in the shape of an inclined paddle, and is introduced into the rotary separator in a state where only coarse powder is cut. You. Therefore, the particle size distribution of the product obtained after passing through the rotary separator and discharging the pulverizer is smaller than the conventional product only in the coarse powder ratio.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 5 relate to an embodiment of the present invention.
1 is an overall vertical cross-sectional view of the vertical mill, FIG. 2 is an enlarged vertical cross-sectional view of a main part of the vertical mill, FIG. 3 is a plan view taken along line XX of FIG. 2, and FIG. FIG. 5 is a vertical sectional view as viewed from Y, and FIG. In the figure, a rotary table 3A which is driven to rotate around a vertical axis via an electric motor 2K and a speed reducer 2 at the lower part of a vertical pulverizer 1 and which is disposed on the outer periphery of the rotary table 3A and rotates following the rotary table 3A. And a plurality of pulverizing rollers 4 are provided. On the upper part of the vertical crusher 1, a raw material charging chute 17 vertically suspended is fixedly provided.
A rotary separator 13 composed of classifying blades 13c arranged at equal circumferences via a rotary shaft 13a and a stay 13b is provided on the outer periphery of the rotary separator 13 so that the rotary separator 13 can be driven to rotate at an arbitrary rotation speed by a drive device (not shown). It has become. The classifying blade 13c has a vertical surface and is attached so that its diameter increases as its longitudinal direction moves upward.

A pre-separator 30 as shown in FIGS. 2 to 4 is fixed to the lower end of the rotary shaft 13a of the rotary separator 13, and is driven to rotate integrally with the rotary separator 13. The pre-separator 30 has two inner and outer cylindrical tubes 30a,
A plurality of plate-like inclined blades 30c are arranged radially in the radial direction at a constant circumferential pitch between the inclined blades 30c.
The inclination direction of 0c is inclined so that the lower part is retracted from the upper part with respect to the rotation direction. The inclination angle θ is selected in the range of 20 ° to 60 ° depending on the type of the raw material, and the inclination angle θ most suitable for the properties of the raw material and suitable for cutting coarse particles or coarse powder is selected. The clearance between the outer peripheral surface of the pre-separator 30 and the inner peripheral surface of the casing 15 is about 10 to 30 mm. The vertical crusher 1 of the present invention has a structure in which the lower end of the rotating shaft 13a of the separator 13 of the conventional vertical crusher is extended and the pre-separator 30 is provided. Since they are the same, the description is omitted.

The operation of the vertical pulverizer 1 of the present invention having the above-described structure will be described. The raw material put on the rotary table 3A is pulverized between the rotary table 3A and the pulverizing roller 4, becomes fine powder, overflows the dam ring 3B, and is blown up into an ascending airflow passing through the annular space passage 14. It becomes dust-containing gas and goes upward. In the upper part of the pulverizer, the rotary separator 13 and the pre-separator 30 rotate coaxially, and the dust-containing gas first passes through the pre-separator 30. At this time, the coarse powder having a relatively large particle size in the dust-containing gas is knocked down by the inclined blades 30c of the pre-separator 30 and returned to the rotary table 3A, while the dust-containing gas that has passed passes through the rotary separator 13. Rotary separator 13
In the pre-separator 30, the dust-containing gas containing only the fine powder from which the coarse powder in the dust-containing gas has been cut is previously classified into the classification blade 13c.
The coarse powder in the fine powder is excluded and cannot pass through, and the dust-containing gas containing the fine powder is discharged through the outlet 16.
Is transported out of the machine and collected by a subsequent collector to become a product. As described above, in the vertical classifier 1 of the present invention, the pre-separator 30 performs two-stage classification in which the pre-separator 30 performs primary classification (or preliminary classification) and the rotary separator 13 performs secondary classification (or main classification). The pre-separator 30 is set at a classification point larger than the classification point of the rotary separator 13 which is the secondary classification, and the particle size distribution of the product obtained by the classification is a characteristic curve composed of the curves A and C in FIG. Is obtained. That is, in FIG. 5, the product having a particle size distribution part classification efficiency in the average particle diameter Dm or more particle size D ₁ (%) is dropped from Pb (%) of that of the conventional product to Pc (%) is obtained. Since the average particle size of this product is lower than that of the conventional product, the average particle size is actually not the average particle size Dm of the conventional product but somewhat lower than Dm.

The classifying point of the pre-separator 30 must be larger than that of the rotary separator 13 and the number of rotations is the same.
This can be achieved by setting the pitch of the inclined blades 30c of the pre-separator 30 to be larger than the pitch of the classification blades 13c by making the pitch smaller than the number of c.

[0013]

As described above, in the vertical pulverizer of the present invention, the pre-separator is provided, and the coarse powder having a relatively large particle size contained in the dust-containing gas is separated before the classification of the rotary separator. Since it is cut and then classified, a product having a coarse powder content larger than the average particle size compared to conventional products can be obtained, and it is possible to meet customer requirements.

[Brief description of the drawings]

FIG. 1 is an overall vertical sectional view of a vertical crusher showing an embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional view of a main part of a vertical pulverizer showing an embodiment of the present invention.

FIG. 3 is a plan view taken along line XX of FIG. 2;

FIG. 4 is a vertical sectional view taken along line YY of FIG. 3;

FIG. 5 is a particle size distribution characteristic curve diagram of a conventional product and a product according to the present invention.

FIG. 6 is an overall vertical sectional view of a conventional vertical crusher.

FIG. 7 is a longitudinal sectional view of a conventional classifier.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vertical grinder 3A Rotary table 4 Grinding roller 13 Rotary separator 13a Rotating shaft 13b Stay 13c Classification blade 15 Casing 17 Material input chute 30 Preseparator 30a Cylindrical tube 30b Cylindrical tube 30c Inclined blade θ Incline angle

Claims (1)

(57) [Claims] A plurality of rotatable crushing rollers are disposed on an outer peripheral upper surface of a rotary table rotatable about a vertical axis. In a vertical pulverizer that pulverizes between the pulverizers, classifying blades having a vertical surface at the top of the pulverizer and expanding in diameter in the vertical or upward direction are arranged in a plurality of equal circles around the center of the rotary table. A rotary separator rotatably driven coaxially is arranged, and a plurality of inclined paddle-shaped inclined blades extending radially in the radial direction at the lower end of the rotating shaft of the rotary separator and arranged in equal parts in the circumferential direction are arranged in the rotational direction. On the other hand, the lower part is inclined so that
A vertical crusher in which a pre-separator that is sloping around is arranged in the middle of the crusher height .