JP3165628B2 - Horizontal wet mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horizontal wet continuous pulverizer of an ultra-fine pulverizer.

[0002]

2. Description of the Related Art FIG. 3 is a longitudinal sectional view showing an example of a conventional horizontal wet mill. Raw material (1) and water (2) are introduced into the mill through an inlet (3) at one end. Ball for grinding (1
4) is stirred by a stirring blade (5) attached to the outer surface of the rotating inner cylinder (4). The raw material is a grinding ball (14)
, While being pulverized, moves downstream in the mill, passes through the openings (9) of the discharge screen (8), and is discharged to the outside through the discharge port (10) as a product (11). The stirring blade (6) on the inner surface of the outer cylinder is mounted to prevent the grinding ball (14) from rotating together with the raw material charged into the mill.

In the case of a slurry having a low viscosity, the slurry is discharged only by the difference in the slurry head, so that the slurry flows out while forming a gradient such as a slurry level code (13).

[0004]

The conventional horizontal wet mill has the following problems to be solved.

1) When pulverizing a slurry having a low viscosity,
Looking at the slurry level in the axial direction of the mill, FIG.
As shown in 3), the material input port side is high and the discharge side is low. This is because the mixing of the raw material (1) and water (2) is still insufficient and the viscosity is high on the raw material input side, but the mixing of the raw material (1) and water (2) becomes better as the pulverization progresses, Is due to the decline. The vicinity of the discharge screen (8) has already been pulverized and mixed, has a considerably low viscosity, and is discharged from the discharge port only by the difference of the slurry head. Also, in the case of raw materials that are difficult to mix, there is a risk of separation when the raw materials and water are charged at once, and the difference in the slurry level between the vicinity of the inlet and the discharge side is further increased. In such a slurry level state, the residence time cannot be taken as planned, and a large amount of play balls are generated, so that ultrafine grinding is very difficult, the target particle size is not reached, and the grinding efficiency is reduced. Therefore, it is necessary to take measures such as increasing the number of revolutions and the ball filling rate, which causes the power to be abnormally increased.

2) Since most of the downstream grinding balls (14) are at a higher level than the slurry level (13),
The pulverizing balls (14) are hit by each other, which is a factor of promoting the wear of the balls.

[0007] 3) When the number of play balls increases as described above, it becomes impossible to remove the crushing heat to the outside by the water-cooled jacket via the slurry, and the inside of the mill becomes hot, and the quality of the crushed product changes. Or it does not reach the planned particle size.

4) When pulverizing raw materials which are difficult to mix and disperse due to a large difference in specific gravity from water or poor hydrophilicity,
If the entire amount of the raw material and water is charged at the same position, mixing in the longitudinal direction inside the mill becomes poor. Then, only water is discharged to the outside, and the raw material remains in the mill, which makes it impossible to pulverize and causes excessive power.

[0009]

In order to solve the above-mentioned conventional problems, the present inventor has set forth a substantially horizontal outer cylinder having a plurality of stirring blades mounted on the inner surface, and a plurality of outer cylinders coaxial with the outer cylinder. An inner cylinder equipped with an agitating blade is provided, a grinding ball is accommodated in an annular cross-sectional space between the outer cylinder and the inner cylinder, and the inner cylinder is rotated to supply the one end of the annular cross-sectional space. Means for supplying liquid to the annular cross-sectional space from the tip of a stirring blade mounted on the inner cylinder in a horizontal wet mill in which the raw material to be pulverized and continuously discharged through a discharge screen provided at the other end portion And a horizontal wet mill characterized in that the opening amount of the discharge screen is formed so that the lower part is smaller than the upper part.

The present invention is constructed as described above, and is provided with a means for supplying a liquid from the tip of the stirring blade mounted on the inner cylinder to the annular cross-sectional space. Mixing becomes slow. Therefore, the pulverization and dispersion of the raw material can be performed sufficiently and reliably.

In the present invention, the opening of the discharge screen is formed so that the opening is narrower in the lower part than in the upper part. Therefore, the lower part of the discharge screen has a large resistance and the slurry is hardly discharged. As a result, the slurry level is increased, so that the crushing performance is improved and the number of play balls is reduced, so that the abrasion of the balls due to the blank hit and the poor heat dissipation are suppressed.

[0012]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, and FIG. 2 is a transverse sectional view taken along the line II-II of FIG.

[0013] The raw material (1) is charged into the inside of the mill from the charging port (3). The charged raw material (1) enters a gap of a grinding ball (14) stirred by a stirring blade (5) attached to an outer surface of a rotating inner cylinder (4). Here, dilution water (2) is supplied from the tip of the stirring blade (5) through the water pipe (12). Since the dilution water (2) is supplied from all of the stirring blades (5), pulverization and mixing gradually and accurately proceed. The raw material (1) and water (2) are slurried while being pulverized and mixed, and move to the downstream of the mill. That is, in the present embodiment, mixing and pulverization are sufficiently performed by gradually adding water to make the mixing gentle.

As shown in FIG. 2, the opening of the discharge screen (8) is A = 7 mm in the upper half (9A) (the opening in which the crushing ball (14) does not come out), and the lower half (9a) is a = 3mm
Thus, the opening amount is formed so that the lower part is smaller than the upper part. Conventionally, the slurry passes through the opening (9) of the discharge screen (8) without any resistance and passes through the discharge port (10) to the outside, but in the present embodiment, the lower half opening (9a) is narrow. (3 mm), the resistance to the slurry increases, making it difficult to discharge. If it becomes difficult to discharge, the slurry level (13) will increase, and if it rises to the position of the conventional wide (7mm) aperture (9A), it will be normal discharge,
It is discharged as a product (11) through the discharge port (10). That is, in the present embodiment, in order to prevent the slurry from being discharged due to the difference in the head of the slurry even when the viscosity decreases, the opening (9) in the lower half of the discharge screen (8) is used.
a) is narrowed to provide a resistance so as not to be easily discharged outside, and to increase the slurry level. As the slurry level increases, the pulverization efficiency (pulverization particle size, pulverization power, etc.) improves. Here, FIG. 4 is a diagram showing the relationship between the screen opening and the slurry level. Comparing the conventional case where all 7 mm is used and the case where 3 mm is used, 3 mm is about 20%.
It can be seen that the slurry level increases.

[0015]

According to the present invention, the following effects can be obtained by the stepwise addition and mixing of the liquid and the maintenance of a high level of the slurry.

1) Significant improvement in pulverizing performance The pulverizing power can be reduced, and the properties of the pulverized product can be eliminated. Further, since the liquid is added stepwise, it is suitable for a raw material that is difficult to mix.

2) Improvement of Cooling Efficiency Since most of the grinding balls are in the liquid, removal of the grinding heat is easy.

3) Improving the life of the crushing ball Since the blank hitting phenomenon of the crushing ball is reduced, the wear of the ball is reduced and the internal crack is hardly generated.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II of FIG.

FIG. 3 is a longitudinal sectional view showing an example of a conventional horizontal wet mill.

FIG. 4 is a diagram showing a relationship between a screen opening and a slurry level.

[Explanation of symbols]

 (1) Raw material (2) Water (3) Input port (4) Inner cylinder (5), (6) Stirrer blade (7) Outer cylinder (8) Discharge screen (9), (9A), (9a) Opening (10) Outlet (11) Product (12) Water pipe (13) Slurry level (14) Ball for grinding

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B02C 17/00-17/24 B01F ^7/ 00-7/32

Claims (1)

(57) [Claims] 1. A substantially horizontal outer cylinder having a plurality of stirring blades mounted on an inner surface thereof, and an inner cylinder having a plurality of stirring blades mounted on an outer surface coaxial with the outer cylinder. The inner ball is rotated while accommodating the crushing ball in the annular cross section space, and the raw material supplied to one end of the annular cross section space is crushed to continuously pass through the discharge screen provided at the other end. In a horizontal wet mill that discharges liquid, a means for supplying liquid from the tip of the stirring blade attached to the inner cylinder to the annular cross-sectional space is provided, and the opening amount of the discharge screen is smaller at the lower part than at the upper part. A horizontal wet mill formed as described above.