JPH03221158A - Vertical mill - Google Patents

Abstract

PURPOSE:To freely control the particle distribution of a ground product by connecting an upper raw material charging port to a dispersion chamber having the first raw material grinding means and allowing a lower raw material charging port to communicate with the second raw material grinding means provided to the lower part in a casing. CONSTITUTION:A dispersing chamber 12 having the first raw material grinding means consisting of a bumper plate 5, the crushing part 8 on a rotor side and the grinding part 9 on a casing side is provided to the upper part in a casing 1. An upper raw material charging port 7 is connected to the dispersing chamber 12 and the dispersing chamber 12 is allowed to communicate with a classifying chamber 11. The second raw material grinding means 22 composed of a roller mill provided to the lower part in the casing 1 is allowed to communicate with a lower raw material charging port 24 and also allowed to communicate with the classifying chamber 11 by an air stream passage 23. As a result, the particle size distribution of a ground product can be freely controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a vertical mill used for pulverizing and classifying raw materials for cement and the like.

Conventional technology In a vertical mill that crushes limestone, coal, etc., the crushed material is transported to the upper part of the casing with airflow by a crushing means installed at the bottom of the casing, and is divided into desired particle size or powder by a classification means. It is classified according to the degree.

On the other hand, the coarse powder is returned to the crushing means and crushed.

Problems to be Solved by the Invention In conventional vertical mills, when grinding a multi-component system such as cement raw material grinding, the pulverizability of each component differs, so the particle size distribution in the pulverized product differs for each component. It becomes something like that.

Further, even if there is no difference in pulverizability, it is very difficult to make only a specific component finer or coarser.

The purpose of this invention is to make it possible to freely adjust the particle size distribution in a pulverized product in view of the above-mentioned early autumn.

Means for Solving the Problems This invention provides a first
A dispersion chamber having a raw material crushing means; an upper raw material input port connected to the dispersion chamber; a classification chamber communicating with the dispersion chamber; a second raw material crushing means provided at a lower portion in the casing; a lower raw material input port that communicates with the raw material crushing means; an airflow passage that communicates the second raw material crushing means with the classification chamber;
The purpose is to achieve the above objective by providing the following.

After driving the working rotor and the second raw material crushing means, when a material with poor classification properties is supplied to the second raw material crushing means from the lower raw material input port, the raw material is crushed and flows into the airflow passage. is carried by the rising air current to the classification room, where it is air classified.

On the other hand, when a raw material with good pulverization properties is introduced into the dispersion chamber from the upper raw material input port, the raw material is crushed by the first raw material crushing means, falls into the classification chamber while being crushed, and is classified there.

Embodiments An embodiment of the present invention will be described with reference to the accompanying drawings, in which the same reference numerals have the same names and functions.

Classifying blade 3 fixed to rotor shaft 13 inside casing l
A 1-inch rotor 2 is installed, and a classification chamber 1 is installed around the outer periphery of the classification blade 3.
1 will be provided.

The classification chamber 11 communicates with the upper raw material input lower via the dispersion chamber 12, and the input a7 is connected to the wind Ji adjustment section 4 with damper D.

The dispersion chamber 12 includes a cylindrical collision plate 5, and first raw material crushing means consisting of a rotor side crushing section 8 and a casing m crushing section 9 provided inside the collision plate 5, respectively.

As shown in the second (2I), a plurality of pins 8 are provided on the upper surface 2a of the rotor 2 of the rotor side part 8 at intervals on a circle A, and the inner surface of the casing of the casing side crushing part 9 9a, a plurality of pins 9 are provided at intervals on a circle B concentric with the circle A.

In short, the pins 8 and 9 only need to be arranged so that the pin mill is III, so they can be changed as necessary. For example, as shown in FIG. , 8b, 8C and pin 9b, 9C1
Lines Arl - Ar5, Brl - Br passing through the center point O of concentric circles Al - A3 and B l - B3 at the position 9d
They may be arranged respectively on g.

A hopper 1O is provided at the bottom of the rotor 2 and is spaced apart from the casing 1, and a roller mill 22, which is a second raw material crushing means and includes a roller 20 and a table 21, is provided directly below the hopper 1O. .

The roller mill 22 communicates with the classification chamber 11 via an airflow passage 23. Furthermore, a lower raw material inlet 24 for supplying raw materials to the roller mill 22 is provided on the side of the casing 1 .

Next, the operation of this embodiment will be explained.

When the rotor shaft 13 is rotated to rotate the classification blades 3 to form a forced vortex, these vortices are discharged from the fine powder discharge duct 6 through the space between the classification blades 3 while swirling within the classification chamber 11 . In this state, when raw material SB, such as IJI, a raw material that has good crushability or is desired to be particularly coarse, is inputted from the upper raw material input lower, the raw material SB is transferred to the dispersion chamber 12.
to fall.

The raw material SB is mainly pulverized by the pin mill in the dispersion chamber 12, a part of which is pulverized 1 by hitting the collision plate 5, changes its traveling direction, and falls into the classification chamber 11. In the classification chamber 11, the fine powder sb and the coarse powder Sc are classified by the balanced action of the centrifugal force and the drag force of the air.

The classified fine powder sb, for example, particles having a particle size of 50 μm or less, rides on the upward airflow, passes through the opening of the rotor 2, is sucked into the fine powder exhaust duct 6, and is collected by an air filter (not shown).

Further, the coarse particles Sc are sent to the hopper 1 while rotating inside the classification chamber 11.
0 onto a roller mill 22 where it is pulverized.

Next, when a raw material SA, for example, a raw material that is poorly pulverized or is particularly desired to be pulverized, is inputted from the lower raw material input port 24, the raw material SA falls onto the roller mill 22 and is pulverized there. After being crushed into a fine powder state, the fine powder Sa rides on the rising airflow flowing through the airflow passage 23 and enters the classification chamber 1.
1, where the fine powder Se and coarse powder Sd are classified by the balanced action of centrifugal force and air drag. This classified fine powder Se, for example, particles with a particle size of 5 μm or less, rides on the upward airflow, passes through the opening of the rotor 2, is sucked into the duct 6, and is collected by an air filter (not shown).

Further, the coarse particles Sd are sent to the hopper 10 while rotating inside the classification chamber 12.
From there, it is discharged onto the roller mill 22, where it is crushed again and classified in the same manner as described above.

The embodiment of the present invention is not limited to the above. For example, instead of forming the pin integrally on the upper surface 2a of the rotor 2, as shown in FIG. A pin mill desk 14 is provided, pins 8a and 8b are provided on the desk 14, and the desk 14 is connected to the rotor shaft 13.
The rotor 2 and the pin mill disk 14 may be rotated independently by fixing the rotor 2 to the rotating shaft 15 loosely fitted with the rotor 2. In this way, the rotation speed of the pin mill disk 14 can be adjusted independently of the rotation speed of the rotor 2. Therefore, by increasing the rotation speed of the pin mill disk 14, which is less likely to be crushed, the crushing ability of the first raw material crushing means can be further enhanced.

Further, instead of forming the pin mill disk 14 horizontally, it may be formed into a mountain-like shape that is inclined downwardly toward the outside, as shown in FIG.

Although this inclination angle θ is appropriately changed as necessary, for example, 30 degrees is adopted.

In this case, compared to the horizontal pin mill desk 14, the area where the pins are disposed becomes larger and the raw material also falls more easily.

Therefore, since many pins 8a to 8f can be provided, the crushing ability can be further improved.

Further, as shown in FIG. 6, a small classification blade 31 is provided between the pin mill desk 30 and the upper surface 2a of the rotor, and
A large classification blade 3 may be provided on the outer periphery of the large classification blade 3 , a small classification chamber 32 may be formed outside the small classification blade 31 , and a large classification chamber 11 may be formed outside the large classification blade 3 .

And raw material SB that has good pulverizability or is desired to be particularly coarse.
is supplied from the upper raw material input lower to the dispersion chamber 12, where,
After being crushed and dispersed, the raw material is dropped into a classification chamber 32 for air classification.

Then, the fine powder sb passes through the small diameter classification blade 31 and the opening of the pin mill desk 30 and is collected in the air filter through the fine powder exhaust duct 6, and the coarse powder Sc falls from the hopper 10 onto the roller mill 22 and is crushed there. . Note that the air volume is adjusted by the damper D of the air volume adjustment section 4 so that the raw material SB is accurately conveyed to the small classification chamber 32 from the upper raw material input lower.

When raw material SA that has poor pulverizability or that is particularly desired to be made fine is dropped from the lower raw material input port 24 onto the roller mill 22,
Therefore, the raw material SA is finely pulverized, and the fine powder Sa
The large classification chamber 11 rides on the airflow rising inside the airflow passage 23.
The fish are transported to Japan, where they are classified. Then, the fine powder Se passes through the large classification blade 3, the opening of the rotor 2, and the opening of the pin mill desk 31, is sucked into the fine powder exhaust duct 6, and is collected by the air filter.

In this embodiment, the separated particle size in the small classification chamber is coarser than that in the large classification chamber, so that the particle size of the raw material supplied from the upper raw material input port can be easily coarsened.

Effects of the Invention Since the vertical mill according to the present invention is configured as described above, when a raw material that has good classification properties or is desired to be coarsened is introduced into the dispersion chamber through the upper raw material input port, the raw material is The raw material is crushed and dispersed by the raw material crushing means, and falls into a classification chamber in a state that is easy to classify, where it is air classified. On the other hand, if raw materials that have poor classification properties or that are desired to be made into fine powder are fed to the second crushing means through the lower raw material input port,
The raw material is pulverized into a fine powder, and the fine powder enters the classification chamber on the airflow flowing through the airflow passage and is air classified.

Since classification is performed in this manner, the particle size distribution in the pulverized product can be freely adjusted, and it is also possible to make only specific components particularly fine or coarse.

Using the conventional vertical mill and the vertical mill of the present invention, the 88 μm residue of each component of cement raw materials (limestone and silica stone) was
% or less was conducted.

As a result, in the conventional example, when the component with the worst crushability, that is, silica stone, was reduced to 10% with an 88 μm residue, the particle size of other components (limestone, etc.) became finer than necessary, resulting in a total of 4.0%. ), but in the present invention, the particle size of each component is uniform (1
Note that the power consumption rate of the present invention is IF!
- OKwn/l, that of the conventional example (21,0Ken/l
), it was found that the power consumption was lower than that of the

[Brief explanation of drawings]

The first section is a longitudinal sectional view showing an embodiment of the present invention, and the second section is a longitudinal cross-sectional view showing an embodiment of the present invention.
3 is a cross-sectional view showing another embodiment, and the figure corresponding to the second section, and FIGS. 4, 5, and 6 show respective embodiments. It is a longitudinal cross-sectional view. 1... Casing 7... Upper M raw material inlet 11... Classification chamber 12... Dispersion chamber 14... Pin mill desk 22... ...-Roller mill 23 ... Air flow passage 24 ... Lower M raw material input port

Claims (8)

[Claims] (1) A dispersion chamber provided in the upper part of the casing and having a first raw material crushing means; an upper raw material input port connected to the dispersion chamber; a classification chamber communicating with the dispersion chamber; a lower part of the casing; a second raw material crushing means provided in;
A vertical mill comprising: a lower raw material input port that communicates with the raw material crushing means; an airflow passage that communicates the second raw material crushing means with the classification chamber; (2) The vertical mill according to claim 1, wherein the classification chamber is formed outside the rotor with classification vanes. (3) The vertical mill according to claim 1, wherein the classification chamber consists of a large classification chamber formed on the outside of the large classification blade and a small classification chamber formed on the outside of the small classification blade. (4) Claim 1, 2, or 3, wherein the first raw material crushing means is a pin mill comprising pins protruding from the inner surface of the casing and the upper surface of the rotor, respectively, which face each other. vertical mill (5) The first raw material crushing means is a pin mill comprising pins protruding from the inner surface of the casing and the pin mill desk, which face each other.
Or the vertical mill described in 3. (6) The vertical mill according to claim 5, wherein the pin mill desk is provided independently from the rotor. (7) The vertical mill according to claim 5 or 6, wherein the pin mill desk is formed in a mountain shape. (8) Claims 1, 2, 3, 4, 5, and 6, wherein the second raw material crushing means is a roller mill.
, or the vertical mill according to No. 7