JPH06104208B2 - Method and apparatus for fine pulverization by continuous dry mixed-flow tank mill - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method and an apparatus for finely pulverizing raw material particles into ultrafine particles of a micron order or less by a continuous dry mixing tank mill.

BACKGROUND ART Fine pulverization of powder is performed by applying a force such as compression, shear, or impact to particles or a particle layer to pulverize it to several microns or less. The pulverizers are roller mills, ball mills, jet mills, and media. Stirring mills and the like are known.

Further, a jet mill, a ball mill, a medium agitation mill, or the like is used to obtain ultrafine particles of a miloquan order or less.

However, in impact methods such as jet mill, there is a limit to the crushing limit particle size, and in media stirring mills and ball mills,
Since balls or the like are used as the crushing medium, it may cause pollution or cause a reverse crushing phenomenon near the critical particle size.

Therefore, there is a limit to finely pulverize the powder only by impact, and it is desirable to use no pulverizing medium to avoid contamination.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention As described above, there is a limit to finely pulverize powder by mechanically applying only impact, and it is difficult to perform ultrafine pulverization on the order of microns or less.

The present invention provides a method and an apparatus for ultrafine pulverization by effective frictional force between raw material particles without using mechanical impact or a pulverization medium.

Means for Solving the Problems In order to achieve the above object, the fine pulverization method of the present invention is a crushing part formed by providing an inner cylinder in the upper half of an outer cylinder, and an inverted conical cylinder provided in the lower half. The raw material supply part of the body is provided, the gap between the raw material supply part and the outer cylinder is air-sealed, and while the air is blown downward from above the crushing part, the raw material supply part is rotated to swirl up the raw material particles to mix in the crushing part. The raw material is finely pulverized by fluidizing and surface pulverization by direct sliding friction between the raw material particles, and only ultrafine particles are sucked and collected outside through a classifier provided in the upper part of the inner cylinder.

In addition, a continuous dry mixing tank mill for ultra-fine pulverization of raw materials has a plurality of baffle plates arranged vertically at equal intervals on the inner peripheral surface of the upper half of the outer cylinder, and is capped and rotated on the outer cylinder. An inner cylinder of a size that substantially abuts the entire length of the tip of the baffle is hung vertically on a lid having a type classifier and a collection hole, and a plurality of baffle plates partitioned by the baffle are provided between the outer and inner cylinders. The crushing part is formed, and the bottom plate of the outer cylinder is penetrated by the raw material supply section, which is a reverse cone-shaped cylindrical body in the lower half of the outer cylinder and has a plurality of drive plates arranged vertically at equal intervals on the inner peripheral surface. The outer end of the outer cylinder and the bottom of the outer cylinder are made to pass through the outer cylinder and the inner cylinder so that the tip end of the material supply device provided outside is supported by the rotating shaft and is driven by the motor. It is installed so that air can be sent in from the upper part of the cylinder surface.

The raw material charged in the raw material supply part of the continuous dry mixed flow mill is
When the raw material supply unit rotates, it rises up to enter the crushing unit, where it is mixed and flowed by the air blown downward from above the crushing unit. It is possible to efficiently produce ultrafine particles of the order or less.

Embodiment An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a mixed flow tank mill (1) according to an embodiment of the present invention. This mixed flow tank mill is provided with a crushing section (2) along the inner peripheral surface of the upper half of the outer cylinder (4) and a raw material supply section (3) in the lower half.

As shown in FIG. 1 and FIG. 2 (a), the crushing section (2) has a plurality of cylinders (2-1) (four are shown in the drawing).
The baffle plates (2-2) consisting of the ridges are arranged vertically at equal intervals, and the baffle group is fitted into the upper half of the outer cylinder (4) so that the baffle plate substantially abuts the entire length of the tip of the baffle plate. A plurality of crushing chambers are formed by combining an inner cylinder (6) suspended from a lid (5).

Further, the raw material supply part (3) has a drive plate (3-2) consisting of a plurality of (four in the drawing are shown) ridges on the inner peripheral surface of the inverted conical cylinder (3-1) at equal intervals. In the vertical direction, the cylinder bottom portion of the raw material supply section (3) is attached to the upper end of the rotary shaft (7) penetrating the bottom plate of the outer cylinder (4) so as to be rotatable.

In addition, the space (3-3) formed between the outer periphery of the upper edge of the inverted conical cylindrical body (3-1) and the outer cylinder (4) is made as small as possible,
In addition, it is desirable to attach Teflon to the outer periphery of the raw material supply unit side. The upper part of the outer cylinder (4) penetrates through the tip part (8) of the raw material feeding device to be desired in the inner cylinder (6) so that the raw material can be charged into the raw material supply part (3).

A motor (9-1) is mounted on the central upper surface of the lid (5), and a rotary classifier (9) is provided at the tip of a motor shaft (9-2) vertically hung downward. Then, a collection hole (5-1) is provided on the upper peripheral surface of the rotary classifier (9). This lid (5) is a required space (1) between it and the crushing section (2).
0) is formed and is crowned to the outer cylinder (4), an air hole (11) is provided in the space (10), and the introduced air descends in the crushing section (2). To do. Also, the outer cylinder (4)
The bottom plate is provided with an annular air passage (12-1) having a large number of small air holes, and the air holes (1
The air introduced from 2) is ejected from the air hole of the air passage (12-1) and rises in the void (3-3) to form an air seal in the void portion.

FIG. 3 shows a specific example of an apparatus for continuously finely pulverizing powder using the above mixed flow mill (1).

A motor (13) is connected to the rotating shaft (7) of the mixed-flow tank mill (1) so as to rotate the raw material supply part (3), and the collection hole (5-1) of the lid (5) is provided. Is joined to one end of a pipe (15) connecting the bag filter (14). Also,
The air holes (11) and (12) are connected to the roots blower (16) by a pipe (17). (18) in the figure is an exhaust blower,
(19) is an operation panel for the motor (13). Then, the raw material stored in the hopper attached to the raw material feeding device (20) can be continuously charged into the raw material supply section (3).

Now, the raw material feeding device (20) is started to load the raw material into the raw material supply section (3), the motor (13) is started to rotate the raw material supply section (3), and the roots blower (16) Then, the blower (18) is started, and the air blown from the air hole (12) rises from the gap (3-3) to form an air seal, and the fine powder particles descending from the crushing section (2) go to the lower part of the outer cylinder. The air blown from the air holes (11) swirls in the space (10) and descends inside the crushing unit, exits from the lower end of the crushing unit and then rises and rotates inside the inner cylinder (6) to prevent falling. Air in the mixing tank mill (1) is sucked and exhausted through the type classifier (9), the pipe (15), the bag filter (14) and the blower (18). Then, the raw material of the raw material supply section (3) rises along the peripheral wall due to the action of centrifugal force due to the rotation, and swirls and rises even after being separated from the upper edge to reach each crushing chamber of the crushing section (2),
Here, the raw material particles are gradually brought into pressure contact with each other as they approach the baffle plate (2-2), and eventually stay.

The moving velocity of the particles in this retention zone becomes extremely small, and the surface is crushed by direct sliding friction between the particles without causing volume crushing.

The finely pulverized particles are lowered by the downward air blown from the air holes (11). Then, the raw material supply unit (3)
Above the above, the finely pulverized particles are attracted by the exhaust gas sucked by the blower (18) to rise in the inner cylinder (6) and pass through the rotary classifier (9) and the pipe (15) to the bag filter ( It is stored in 14).

On the other hand, particles that have not been finely pulverized are separated by the rotary classifier (9), fall without being sucked into the exhaust gas, and are accommodated in the raw material supply unit (3). Done.

The classifier for classifying the fine particles after crushing to separate only the ultrafine particles has been described with respect to the case where a rotary classifier is used, but the classifier is not limited to this rotary type, and other types such as an air flow classifier are also used. Formats are available.

EFFECTS OF THE INVENTION The present invention uses a continuous dry mixing tank mill having a crushing part in the upper part and a raw material supply part in the lower part to finely pulverize raw material particles by surface pulverization by direct sliding friction. It can be pulverized into ultrafine particles of the order or less.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a continuous dry mixed flow mill according to an embodiment of the present invention, FIG. 2 (a) is a lateral sectional view taken along the line AA in FIG. 1, and FIG. 2 (b) is FIG. 1B-B. FIG. 3 is an explanatory view showing an example of an apparatus for carrying out the pulverizing method of the present invention. 1 ... Mixed-flow tank mill 2 ... Crushing part 2-1 ... Cylinder, 2-2 ... Baffle plate 3 ... Raw material supply part 3-1 ... Inverted conical cylinder 3-2 ... Drive plate 4 …… Outer cylinder 5 …… Lid body, 5-1 …… Collection hole 6 …… Inner cylinder, 7 …… Rotating shaft 8 …… Tip, 9 …… Rotary classifier 10 …… Space, 11, 12… … Air holes 13 …… Motor, 14 …… Bag filter 16 …… Roots blower, 18 …… Blower 19 …… Operation panel, 20 …… Raw material feeding device

Claims (2)

[Claims] 1. A raw material supply part of an inverted conical cylindrical body provided in the lower half part is provided for a crushing part formed by providing an inner cylinder in the upper half part of the outer cylinder. The air gap is air-sealed, and while the air is blown downward from above the crushing part, the raw material supply part is rotated to swirl up the raw material particles to mix and flow them in the crushing part, and the raw material is finely divided by surface sliding by direct sliding friction between the raw material particles. A fine pulverization method using a continuous dry mixing tank mill, which comprises pulverizing, and sucking only ultrafine particles to the outside through a classifier provided on the upper part of the inner cylinder to collect. 2. A lid body having a plurality of baffle plates vertically arranged at equal intervals on an inner peripheral surface of an upper half portion of an outer cylinder, capped on the outer cylinder, having a rotary classifier and a collection hole, An inner cylinder of a size that substantially abuts the entire length of the front end of the baffle plate is hung vertically to form a plurality of crushing parts partitioned by the baffle plate between the outer and inner cylinders, and the lower half part of the outer cylinder is formed. A raw material supply section, which is an inverted conical tubular body and has a plurality of drive plates vertically arranged at equal intervals on its inner peripheral surface, is rotatably supported by a rotary shaft that penetrates the bottom plate of the outer cylinder and driven by a motor. The outer end and the inner end of the raw material supply device are provided on the outer cylinder and the inner cylinder so that they are desired on the raw material supply section. Dry mixing tank mill.