JP2918679B2 - Dry media mill - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a dry media mill for continuously and efficiently performing pulverization.

(Conventional technology) As a continuous type dry medium mill, there is a type in which a grinding ball is put into a container together with a material to be ground (hereinafter referred to as a raw material), and a stirring blade is rotated to perform stirring and pulverization. The air was discharged out of the machine together with the introduced air, and was collected by a classifier and a dust collector, or a cyclone.

(Problems to be Solved by the Invention) Dry media mills are generally inferior to wet media mills in terms of both throughput and product particle size in terms of grinding ability. this is,
One of the reasons is that the pulverized raw material powder adheres to the surface of the pulverized ball and serves as a buffer when the pulverized ball collides, thereby weakening the pulverizing effect. In addition, since these fine powders are firmly adhered to the crushed ball surface, they cannot be easily peeled off by the carrier air. As a result, sufficient pulverizing power cannot be imparted, the amount of raw material charged in the pulverizing chamber gradually increases, supply of new raw material is suppressed, and the pulverizing capacity is reduced.

However, the dry-type media mill has advantages such as less wear of the crushed balls and the elimination of the drying and crushing steps as compared with the wet-type media mill, and the use range can be expanded by solving the above problems.

SUMMARY OF THE INVENTION The present invention provides a dry-wet media mill that consumes less power, has excellent processing capacity, and can efficiently produce products having a small product particle size.

(Means for Solving the Problems) As a result of investigating and examining the above problems, it is desirable that the finely pulverized raw material powder be quickly discharged out of the machine. However, it is difficult to completely remove only the fine powder from the grinding chamber in which the raw materials of various stages are mixed, from the raw material of the pulverizing balls and the raw material to the raw material in the pulverizing process. This is because the same centrifugal force moves between the raw material and the crushed ball by the stirring blade,
Because they are pressed against the inner wall side of the container, unless the introduced air is considerably increased, they cannot be moved upward or fine powder can be separated therefrom. In addition, when the introduced air is excessively increased, there is also a problem that unmilled raw materials and crushed balls are discharged, or coarse powder is mixed into fine powder, thereby lowering product accuracy.

The present invention is to separate the raw material and the crushing ball together after moving them to a different place from the crushing chamber, and the configuration is such that the inside of the container is concentric with the stirring blade rotating along the inner surface of the container. The cylindrical member is disposed with an appropriate gap between the upper and lower surfaces of the container, an outlet having a diameter smaller than the inner diameter of the cylindrical member is provided on the upper surface of the container above the cylindrical member, and a raw material supply pipe and air are further provided in the cylindrical member. Introducing the introduction pipe,
The operation will be described below.

(Operation) The raw material supplied into the cylindrical member at the center of the container is fed into a pulverizing chamber outside the cylindrical member through a gap between the cylindrical member and the bottom surface of the container. Is finely pulverized. In addition, part of the air sent into the cylindrical member descends inside the cylindrical member together with the raw material, enters the pulverizing chamber along the container bottom surface, passes through the gap above the cylindrical member from the pulverizing chamber, and exits from the discharge port through the discharge port. And the remaining air reverses and rises above the cylindrical member and passes directly to the discharge port. The raw material and the crushed balls move as follows by the two air flows. That is, the raw material and the grinding balls in the grinding chamber are mainly pushed up by the rotational force of the cylindrical member and a part of the air, and are extruded from the gap above the cylindrical member. At this time, the raw material powder pulverized to a certain degree is discharged from the discharge port through the discharge port by the air, but the pulverized ball and the unpulverized coarse raw material which are strongly subjected to centrifugal force fall into the cylindrical member. Next, in the cylindrical member, the crushed balls collide with each other in the absence of fine powder, or the crushed ball collides with the inner surface of the cylindrical member, and the fine powder attached to the crushed ball surface is peeled off. It is transported outside the machine on the flowing air. Then, the crushed balls and the uncrushed coarse-grained raw material are sent again into the crushing chamber under the cylindrical member, and at this time, the raw material from the raw material supply pipe is also sent.

In this way, the finely pulverized raw material is discharged out of the apparatus without being kept in the pulverizing chamber for a long time, and the pulverized surface of the pulverized ball is renewed by peeling off the fine powder attached to the surface of the pulverized ball.

(Effects of the Invention) As described above, according to the present invention, the finely pulverized raw material powder can be quickly discharged to the outside of the machine without being kept in the pulverizing chamber for a long time. Things can be obtained. Further, power consumption can be reduced and wear of the crushed ball can be reduced. Further, the fine powder attached to the surface of the crushed ball can be removed to renew the crushed surface, and the crushing effect can be maintained and the crushing performance can be improved.

Example Next, an example will be described with reference to FIG. The base 1 has a driving device 4 including an electric motor 2 and a transmission 3 and a cylindrical container 5.
Is fixed, and a rotating shaft 4 a of the driving device 4 is provided at the center of the container 5. An umbrella-shaped support 6 is attached to the tip of the rotating shaft 4a, a plurality of support rods 7 are attached to the support 6, and the other end of the support rod 7 is joined to the inside of the cylindrical member 8, The cylindrical member 8 is held. A plurality of agitating blades 9 are arranged at equal intervals on the outer periphery of the cylindrical member 8 to form a pulverizing chamber 10 between the cylindrical member 8 and the container 5. The passage 11 is formed with an appropriate gap so that the raw material and the crushed balls circulate around the cylindrical member 8. Therefore, the inner surface 5a of the container 5 has a curved surface with no corners.

At the bottom of the container 5, an umbrella 12 for guiding the raw material to the outer periphery is provided.
In addition to the above, a blow port 13 for introducing air or an inert gas is provided below the umbrella-shaped body 12, and is connected to the blower 41 or the inert gas source 29. In addition, a discharge port 14 which is concentric with the container 5 and has a smaller diameter than the cylindrical member 8 is provided at the upper part of the container 5 and is connected to a classifier 31. An adjustable inner cylinder 15 is attached to the inlet of the discharge port 14, and is arranged so that its lower end protrudes slightly below the upper inner surface 5 a of the container 5.

A double pipe composed of a raw material supply pipe 16 and an air introduction pipe 18 is disposed at the discharge port 14 so as to penetrate the central part thereof, and is disposed such that an end of the pipe is located above the support 6. . A blower 39 is connected to the outer air introduction pipe 18, and a screw type supply pipe 27 is connected to the side of the inner raw material supply pipe 16,
The raw material supply pipe 16 is extended upward to communicate with a classifier 31, and a circulation path 17 for returning the coarse powder after classification and sorting into the container 5.
Is formed.

The classifier 31 has a classifying chamber 33 in which a classifying impeller 32 supported at an upper portion is disposed, a fine powder discharge port 34 that is discharged through the inside of the classifying impeller 32, and a lower small diameter provided below the classifying chamber 33. It comprises a conical annular portion 35 having an inclined surface, and a secondary air inlet 36 provided on the outer peripheral portion of the machine body below the conical annular portion 35. The coarse powder classified and sorted by the classifier 31 is returned into the container 5 through the circulation path 17, and the fine powder discharged from the fine powder discharge port 34 is collected by a bag filter 37. Note that a blower 38 is connected to the bag filter 37.

An air outlet 19 is provided in the upper part of the outer periphery of the container 5, and a blower
40 is connected to blow air toward the gap 11 above the cylindrical member 8.

A jacket 20 is provided around the outer periphery of the container 5, and a heating or coolant supply source 30 is connected to the jacket 20.

(Another Embodiment) Figs. 2 and 3 show another embodiment, in which a perforated plate 21 is attached to the bottom of the container 5, and an air chamber 22 is provided below the perforated plate.
The blower 41 is connected so that a fluidizing action is provided at the inner bottom portion of the cylindrical member 8. Further, a plurality of pin-shaped stirring members 23 are alternately arranged on the inner wall of the cylindrical member 8 and the outside of the air introduction pipe 16 so as to add both the stirring and the crushing action inside the cylindrical member 8. Like that.

The shape of the support rod 7 is circular, elliptical, square, flat,
Any of rhombic shapes may be used, but the flat plate may be inclined in the rotation direction side or the counter rotation direction side of the stirring blade 9 as shown in the figure to enhance the stirring effect on the raw material and the grinding balls.

A large number of small pieces 24 are attached to the peripheral wall of the discharge port 14, and as shown in FIG. 3, the small pieces 24 are inclined in the anti-rotation direction with respect to the circulating air flow e in the container 5 to form slit-shaped gaps 25. The gap 25 is placed on the air flow f to allow the pulverized raw material to pass therethrough, while the pulverized ball P is dropped into the cylindrical member 8 without passing through.

The coarse powder from the classifier 31 is returned to the hopper 28 of the feeder 27 via the rotary bubble 26. Further, the shape of the stirring blade 9 can be variously changed in design.
One example is shown in the figure. The flat plate 9a is inclined rearward in the rotation direction as shown in FIG.
The lower part of the flat plate 9a is rotated and tilted rearward with respect to the axial direction, or it is composed of a large number of pins 9c and small piece members as shown in (C), or the stirring blade 9d is formed as a cylindrical member as shown in (D). 8 may be integrally formed.

In addition, a gap may be provided between the stirring blade 9 and the cylindrical member 8, and a spacer may be attached between both members, or may be separately held by separate support rods 7 having different lengths.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the structure of the accompanying drawings by the entry.

[Brief description of the drawings]

1 is a cross-sectional view of a main part of this embodiment, FIG. 2 is a cross-sectional view of a main part of another embodiment, FIG. 3 is an enlarged cross-sectional view of a portion II in FIG. 2, and FIG. Example 9 is an example. In the figure, 5 ... container, 5a ... inner surface, 8 ... cylindrical member, 9 ... stirring blade, 11 ... gap, 12 ... umbrella, 13 ...
... Inlet, 14 ... Outlet, 15 ... Inner cylinder, 16 ... Raw material supply pipe, 17 ... Circulation path, 18 ... Air introduction pipe, 19 ... Air outlet, 20 ... Jacket, 22 ... ... air chamber, 23 ... stirring member, 24 ... small piece, 25 ... slit-shaped gap, 31 ... classifier.

Claims (11)

(57) [Claims] 1. A crusher of the type in which crushing balls are put into a container and a stirring blade is rotated, and a concentric cylindrical member 8 is provided inside a stirring blade 9 with an appropriate gap 11 on the upper and lower surfaces of the container 5.
A discharge port 14 having a diameter smaller than the inner diameter of the cylindrical member 8 is provided on the upper surface of the container 5 above the cylindrical member 8.
A dry medium mill characterized in that a raw material supply pipe 16 and an air introduction pipe 18 are provided therein. 2. The dry medium mill according to claim 1, wherein the stirring blades 9 are attached to an outer peripheral portion of the cylindrical member 8. 3. The dry-type medium mill according to claim 1, wherein a plurality of agitating members are mounted on an inner surface of the cylindrical member and an outer peripheral portion of the air introducing pipe. 4. The dry medium mill according to claim 1, wherein the raw material supply pipe 16 and the air introduction pipe 18 are constituted by double pipes, and the double pipe is disposed so as to penetrate from the upper portion to the center of the discharge port 14 from above. . 5. The dry-type medium mill according to claim 1, further comprising a cylinder 15 protruding below the inner surface 5a of the container 5 at an inlet of the discharge port 14. 6. A dry medium mill according to claim 1, wherein a number of small pieces are arranged on the peripheral wall of the inlet of the discharge port so as to be inclined in the counter-rotating direction of the stirring blade to form slit-shaped gaps. . 7. A circulation path 17 for feeding the recovered coarse powder in the classifier 31 into the container 5 by extending the upper end of the other end of the raw material supply pipe 16 and connecting to the classifier 31. 2. A dry media mill according to claim 1. 8. The dry media mill according to claim 1, wherein a perforated plate 21 is attached to the bottom of the container 5 and a blower 41 is connected below the perforated plate 21 to provide an air chamber 22. 9. A dry media mill according to claim 1, wherein an umbrella-shaped body having an air or inert gas inlet is disposed at the center of the bottom of the container. 10. The dry medium mill according to claim 1, further comprising an air outlet opening above the outer peripheral portion of the container toward the gap above the cylindrical member. 11. The dry medium mill according to claim 1, wherein a jacket 20 for heating or cooling is provided on an outer peripheral portion of the container 5.