JPH0466134A - Vertical type crusher - Google Patents

Abstract

PURPOSE:To make small the mixing ratio of fine powder in a raw material and carry out the safe operation continuously for a long time by providing a guide cone of almost reverse truncated conical trapezoid shape for introducing dust containing gas right under a rotating separator. CONSTITUTION:A rotating table 3 and a plurality of crushing rollers 4 rotating following the rotation of the table 3 disposed on the table 3 are disposed in casings 1a and 1b.A rotating shaft 13 disposed in the vertical direction and a rotating separator 12 supported by the rotating shaft 1 and provided with rotating vanes 15 of a almost L-shaped horizontal shape disposed in the ring shape and radial shape surrounding the rotating shaft 1 are disposed on the upper sections of said casings.A guide cone 20 of almost reverse truncated conical trapezoid shape for introducing dust containing gas is fixed right under said separator 12 through a stay 22 disposed in tension from the inner faces of the casings almost horizontally. As a result, the mixing ratio of fine powder in a raw material is made small, and the stable operation continuing for a long time can be carried out.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides the following advantages:
This relates to a vertical crusher that crushes cement raw materials, coal, chemicals, etc.

[Prior art] Vertical crushers equipped with a rotary table and crushing rollers are widely used as a type of crusher for pulverizing powdered materials such as cement raw materials and coal-1 chemicals into fine powder. This type of crusher has a disc-shaped rotary table that rotates at low speed driven by a motor with a reducer in the lower part of a cylindrical casing, and a part that divides the outer periphery of the upper surface equally in the circumferential direction, which is pressed by hydraulic pressure etc. It is equipped with a plurality of crushing rollers that are driven and rotated.

For example, in FIG. 3, which shows a conventional vertical crusher, the crusher, designated as a whole by reference numeral 1, is visually formed as a single tower body consisting of a mill casing 1a and a separator casing 1b, and an electric motor is installed at the base of the crusher. A rotary table 3 rotated by a motor 2 and a speed reducer 17 is arranged. A plurality of conical crushing rollers 4 are arranged to rotate in sliding contact with the rotary table 3, and the crushing rollers 4 are rotatably supported on a support arm 5. The support arm 5 is fixed to a support shaft 6 rotatably supported on the crusher side. One end of a rotating arm 7 is further fixed to this support shaft 6, and this rotating arm 7 extends downward through the side of a casing 8 surrounding the rotating table 3, and faces the lower space of the crusher. There is. The lower end of this rotary arm 7 is connected to a rod 10 of a pressure cylinder 9 whose lower end is rotatably supported on the base of the crusher 1.
It is rotatably supported on the tip of the shaft.

The fluid as a raw material supplied to the center of the rotary table 3 through a supply pipe (not shown) is caught between the driven roller 4 and the rotary table 3 by rotation of the table, and is pulverized. On the other hand, hot air is guided into the casing 8 by a duct (not shown), and this hot air blows up from the annular space 14 between the outer peripheral surface of the rotary table 3 and the inner peripheral surface of the casing 8. The fine powder rises inside the crusher 1 while being dried, and is discharged from the discharge pipe 16 as a mixture with hot air and sent to the next process.

Note that some of the coarse particles also rise within the crusher 1, but are classified by the rotary blades 15 of the upper separator 12 and returned onto the rotary table 3.

One type of separator that is widely used is a rotary separator, in which a rotating shaft 13 is provided in the classification section, and a plurality of rotating blades 15 are fixed to the rotating shaft 13 at equal pitches. It is rotated along with the shaft at an arbitrary rotation speed.

[Problems to be Solved by the Invention] In the vertical crusher configured as described above, the pulverized raw material supplied onto the rotary table is crushed by the rotary table and the crushing rollers, overflows the rotary table, and is crushed into the annular space. Approximately 20m/s to 50m/ blown up from 14
The airflow passing through the annular space 14 is blown upward by the high-speed airflow of s and heads toward the rotary separator, but the cross-sectional area of the airflow that has passed through the annular space 14 is expanded to approximately the circular area of the inner diameter of the casing, and as a result, the flow velocity rapidly decreases. Powder (arrow A in the diagram) rising on the airflow toward the separator shown in Figure 4,
Coarse particles and powder that stall and fall onto the rotating table (
It is divided into two parts (arrow B shown in the figure).

However, products with a particularly small particle size distribution, such as 1 to 5
In the case of grinding conditions that require μm or submicron particles, the particle size of the powder (8 particles) returned to the rotary table is also smaller than in the case of grinding conditions that yield a normal pulverized product (for example, an average particle size of 10 to 30 μm). As a result, the proportion of fine powder present on the rotary table increases, and the vibration value (half amplitude of the vibration waveform) generated during the operation of the crusher increases (which hinders stable operation). Therefore, it is necessary to direct most of the fine powder that has overflowed the rotary table toward the separator, and to prevent the fine powder from returning to the rotary table on the way to the separator.

[Means for Solving the Problems] Therefore, in the vertical crusher of the present invention, a rotary table is provided in the casing, and a plurality of rotary tables arranged on the rotary table are rotated in accordance with the rotation of the rotary table. a crushing roller, and a rotating shaft installed vertically in the upper part of the casing, and abbreviations supported by the rotating shaft and arranged annularly and radially around the rotating shaft. In a vertical crusher equipped with a rotary separator equipped with rotary blades having a horizontal cross-sectional shape, a guide cone having a substantially inverted truncated conical shape for guiding dust-containing gas is provided directly under the rotary separator in the casing. It has a structure in which it is fixed via a stay that extends approximately horizontally from the inner surface.

[Function] In the vertical crusher of the present invention, a guide cone having a substantially truncated cone shape for guiding dust-containing gas is fixed directly below the rotary separator by a stay projecting horizontally from the casing. Therefore, the airflow passing through the annular space can flow annularly toward the separator without causing a significant decrease in flow velocity, so that most of the fine powder after pulverization is subjected to the classification action of the separator and is transferred onto the rotary table on the way. Since turning is prevented, the rate of contamination of fine powder of raw materials on the rotary table is reduced. Therefore, even in operations where grinding conditions are severe and a large amount of fine powder is required, vibrations can be kept to a relatively small level.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

1 and 2 show embodiments of the present invention, FIG. 1 is an enlarged vertical sectional view of the main part, FIG. 2 shows various embodiments of the guide cone, and FIG. 2(a) is a reverse sectional view. Fig. 2(b) shows a truncated cone with cylinders connected above and below, and Fig. 2(C) shows a truncated cone with cylinders connected only below the truncated cone. show.

In the figure, 1 is a crusher, 3 is a rotary table, and 4 is a crushing roller. Among other symbols, those having the same symbols as those of the conventional vertical crusher explained in FIG. 4 will not be described. As shown in the figure, a guide cone 20 having a substantially truncated conical shape is placed on the center line of the vertical crusher directly below the separator 12.
is fixed by a plate-shaped stay 22 that projects approximately horizontally from the inner surface of the circumferential plurality of casings 1a.

This guide cone 20 is shown in FIG. 2 (aL Fbl).

(Guide cones 20a, 20b shown in cl.
.

20c can be used instead.

Note that the above-mentioned stay 22 may be made of a steel pipe such as SGP instead of a steel plate.

Next, the operation of the vertical crusher configured as above will be explained. After starting the electric motor 2 and rotating the rotary table 3 and the separator 12, the raw material is dropped and supplied to approximately the center of the rotary table 3 via a raw material supply chute (not shown), and this raw material is transferred to the rotating rotary table 3. The centrifugal force causes the rotary table 3 to move toward the outer periphery of the rotary table 3 in a spiral trajectory. A crushing roller 4 rotates on the outer periphery of the rotary table 3, and most of the moved raw material is caught between the crushing roller 4 and the rotary table 3, and is crushed by compression, impact, and shearing action into fine powder. Become. This fine powder, coarse particles that overflow the rotary table without being bitten by the crushing roller 4, and intermediate particles that have been crushed but have not reached the final product fineness fall into the annular space 14, but at this time, Since the hot air sent through the duct by the hot air generator blows up into the annular space 14, these fine powders, intermediate particles, and coarse particles rise inside the crusher together with the hot air. Even after passing through the annular space 14,
The guide cone 20 installed directly below the separator maintains the cross-sectional area of the hot air in an annular shape that is narrower than the conventional circular shape, so the drop in flow velocity of the hot air is relatively small, allowing coarse particles and intermediate particles that require a large amount of energy to float. However, fine powder with a smaller particle size rises and heads toward the rotating blade 15 of the separator 12, and after being classified, the fine powder passes through the rotating blade 15 and is discharged into the discharge pipe 16.
It is discharged from the air and collected through a hawker, etc. Further, the fine powder that has not passed through the separator 12 and the rotary blades 15 is knocked down by the rotary blades 15, falls onto the rotary table 3, and is returned to the rotary table 3, where the pulverization and classification are repeated again.

As mentioned above, conventional vertical crushers produce not only coarse particles and intermediate particles (the final product, fine powder, is also produced by the separator 12).
may fall onto rotary table 3 on the way to
Therefore, the present invention can prevent the inconvenience of frequent occurrence of vibrations when the proportion of fine powder in the raw material is high, which is often observed in operations under severe grinding conditions to obtain fine powder with a small particle size.

That is, in the present invention, a zone is provided directly below the separator in which the cross-sectional area of the air flow is reduced to maintain a certain flow velocity, so that the fine powder is directed toward the separator as much as possible. However, if the reduction is too extreme, coarse particles and intermediate particles that should be immediately returned to the rotary table among the particles that overflow from the rotary table will also be lifted up to the separator, which is uneconomical. The reduction must be appropriately selected; for example, the annular area at the height of the guide cone may be selected to be 30 to 60% of the total circular cross-sectional area.

[Effects of the Invention] As described above, in the vertical crusher of the present invention, the guide cone is provided directly below the separator, so there is almost no stalling during the rise of fine powder to the separator, and a short path to the rotary table is achieved. Since [return] is prevented, the mixing ratio of fine powder in the raw material is relatively small, making it difficult for large vibrations to occur, especially during grinding operations where the product fineness is small, ensuring long-term continuous stable operation, resulting in increased production efficiency. This also improves maintainability.

[Brief explanation of drawings]

1 and 2 show embodiments of the present invention, FIG. 1 is an enlarged vertical sectional view of the main part of a vertical crusher, FIG. 2 shows various embodiments of the guide cone, and FIG. Fig. 2 (b) shows a cylinder connected to the upper and lower sides of the inverted truncated cone, and Fig. 2 (C) shows only the lower part of the inverted truncated cone. Shows connected cylinders. 3 and 4 show conventional embodiments, FIG. 3 is an overall longitudinal sectional view of a vertical crusher, and FIG. 4 is an enlarged longitudinal sectional view of a main part to explain the movement of particles. 1... Vertical crusher, 3... Rotating table, 4... Grinding roller, 12... Separator, 13... Separator Rotating axis, 14
......Annular space part, 15...Rotating blade of separator, 20, 2
0a, 20b, 20c--Guide cone, 22...Stay

Claims (1)

[Claims] (1) It has a rotary table in the casing and a plurality of crushing rollers that are rotated as a result of the rotation of the rotary table placed on the rotary table, and the upper part of the casing has a vertical direction A vertical separator equipped with a rotating shaft installed in the rotary shaft and a rotary separator supported by the rotating shaft and having rotating blades having a substantially L-shaped horizontal cross section and arranged annularly and radially around the rotating shaft. The type crusher is characterized in that a guide cone having a substantially inverted truncated cone shape for guiding dust-containing gas is fixed directly below the rotary separator via a stay extending substantially horizontally from the inner surface of the casing. Vertical crusher.