JP2553933B2 - Centrifugal fluid pulverizer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a crusher. More specifically, the present invention relates to a wet centrifugal fluidizing and pulverizing apparatus that is equipped with an outer peripheral ring and a rotary dish, and that pulverizes raw materials by centrifugally flowing a pulverizing medium such as steel balls or ceramic balls contained in the apparatus. is there.

[Prior Art] There are various types of crushing devices such as a tube mill and a rigid mill, but the steel balls or ceramics housed inside by arranging the rotary plate upward and rotating the rotary plate. Known is a rigid ball mill in which a grinding medium such as balls (hereinafter referred to as balls) is circulated to grind and grind raw materials.

In this type of rigid ball mill that has been used for a long time, there is a problem that the crushing and grinding actions are weak, or the energy input to the device is easily consumed in addition to the crushing and grinding actions, and the energy efficiency is low. there were.

Therefore, the present applicant has filed a patent application for a centrifugal fluidizing and pulverizing apparatus having a rotating dish and a fixed ring as described below (Japanese Patent Application No. 60-
265379,60-266867 to 266887,61-99745).

This rotating dish has a rotation axis oriented in the vertical direction, at least a central portion of which has a dish surface whose diameter expands downward, and a vertical cross section of the dish surface is concavely curved. It is like a dish.

The stationary ring has an inner wall surface with at least an upper portion having a diameter reduced upward, and has a shape in which a vertical cross section of the inner wall surface is curved in a concave shape. ing.

Further, in the centrifugal fluidizer, the plate surface of the rotary plate and the inner wall surface of the fixed ring are formed into a continuous smooth surface except for a minute gap between the rotary plate and the fixed ring.

[Problems to be Solved by the Invention] However, when the material to be crushed is finely ground, for example, ceramics such as silicon nitride or silicon carbide, magnetic materials, electronic materials, or fine powders as raw materials for pigments and paints To obtain submicron fine powder of about 0.5μ,
In the dry centrifugal fluidizing and pulverizing apparatus, it is very difficult to stably obtain submicron particles because extra processing such as crushing is required for agglomeration of pulverized fine powders.

Further, only the product having a large particle size distribution was obtained, and it was difficult to obtain a narrow particle size distribution centering on submicron particles.

[Means for Solving the Problems] In the device of the present invention, in order to solve the above problems and obtain a large number of submicron particles of these pulverized materials by effective pulverization, a wet pulverization system is adopted, and the rotation axis is vertical. A rotatable circular dish having a dish surface that faces toward the direction, at least a central portion of which has a diameter increasing downward, and a longitudinal cross section of the dish surface is concavely curved, A fixed ring that has an inner wall surface whose upper portion is reduced in diameter upward, and has a shape in which the vertical cross section of the inner wall surface is curved in a substantially concave shape, and is stationary around the rotary dish coaxially. In the centrifugal fluidizing and pulverizing device, the plate surface of the rotary plate and the inner wall surface of the fixed ring are formed into a continuous smooth surface except for a minute gap between the rotary plate and the fixed ring. There is a through hole near the bottom of the rotating dish, and the lower surface of the outer periphery of the rotating dish is crushed. Circulation vanes for transfer of solid-liquid two-phase fluid containing the powder is provided, and the structure provided with the container and an outlet of the solid-liquid two-phase fluid to the underside of the rotary disc.

[Operation] In the centrifugal fluidizing and grinding apparatus of the present invention, a fluid such as water is added to the material to be ground and the rotary dish is rotated around the vertical axis. Therefore, the fluid containing fine powder generated as the grinding progresses It moves to the inside of the container through the through hole provided near the bottom of the rotary plate, and then moves to the outer peripheral side of the container by the stirring action of the circulation blades laid on the lower surface of the outer peripheral part of the rotary plate, between the rotary plate and the fixed ring. To rise above the minute gap to form a circulating flow.

In this way, the material to be crushed in the apparatus becomes finer with the passage of time, and after a certain period of time, a product having the required powder particle size can be obtained.

Then, the rotation of the rotary dish is stopped, the fluid containing the fine powder is taken out from the discharge port of the container, and one batch operation is completed.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall vertical sectional view of an apparatus according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of an essential part showing another embodiment of the present invention.

In FIG. 1, reference numeral 1 is a fixed ring, 2 is a rotary plate, 3 is a rotary shaft, 4 is a bearing box, 5 is a shaft coupling, 6 is a variable speed electric motor,
7 is a casing, 8 is a chute for throwing the object to be crushed, 9 is a stand, 10 is a container, 11 is an outlet, 12 is a circulation blade, and 23 is a crushing chamber. The rotating tray 2 is a bearing box 4 fixed to a casing 7.
It is supported and suspended by an inner bearing, and is rotationally driven by a variable speed electric motor 6 fixed to the top of a casing 7.

On the other hand, through holes 2m with a diameter of about 8 mm are arranged at equal intervals around the circumference of the bottom of the rotating dish, and a circular ring-shaped minute of about 0.5 to 1 mm is provided between the outermost end of the rotating dish and the fixed ring. A gap 2n is provided.

A container 10 for storing the fluid dropped from the through hole 2a is fixedly provided on the lower side of the rotary dish, and an outlet 11 for the fluid is attached at one place on the circumference.

In addition, in the space between the rotary plate 2 and the container 10, the rotary plate 2
On the lower surface of the outer peripheral part of the circle at equal intervals, for example, 6
Up to 8 circulation blades 12 are attached, and they rotate in the space as the rotary plate 2 rotates.

Further, in another embodiment of the present invention shown in FIG.
The rotary disc 2 is supported from below by a bearing 4a of a bearing box 4 and is rotated by driving a rotary shaft 3.

Next, the configurations of the fixed ring 1 and the rotary plate 2 will be described in detail with reference to FIG.

The fixed ring 1 has a ring shape installed with the axial direction being the vertical direction, and the diameter in the middle of the height direction (hereinafter referred to as the middle part) 1b is the largest. In the fixed ring 1, a lower portion (hereinafter, referred to as a lower portion) 1c is slightly reduced in diameter from the middle portion 1b, and an upper portion (hereinafter, referred to as an upper portion) 1a is reduced in diameter from the middle portion. are doing. Therefore,
The inner wall surface 1A of the fixed ring 1 is slightly expanded in diameter from the lower portion 1c toward the middle portion 1b, the middle portion 1b is substantially vertical, and the middle portion 1b is located at the upper portion.
The diameter of the inner wall surface 1A is reduced toward 1a, and the vertical cross section of the inner wall surface 1A is curved in a substantially concave shape. The inner wall surface may be a straight line as shown in FIG. The middle part of the fixed ring 1
A flange 25 is projected on the outer peripheral surface of 1b, and the flange 25 is placed on a flange 26 projected on the outer circumference of the upper end of the container 10,
It is fixed by bolts 27.

The plate surface 2A of the rotary plate 2 has a shape in which the diameter increases downward in the central portion 2a, and the intermediate portion 2b continues to the central portion.
Is almost horizontal, and the outer peripheral portion continues to the intermediate portion 2b.
In 2c, the diameter is increased upward. This plate surface 2A
Is curved in a concave shape as a whole, and the inner wall surface 1A of the fixed ring 1 and the dish surface 2A form a continuous smooth surface except for a minute gap 2n between the fixed ring 1 and the rotary dish 2. are doing.

A pointed cap 30 is attached to the central portion of the rotary plate 2 and is fixed by a bolt 31. A shaft hole 32 is formed in the central portion of the rotary dish 2, and the upper end of the support block 34 is fitted in the shaft hole 32. The lower end of the bolt 31 is screwed into a piece 33 provided on the upper end of the support block 34.

Although not shown, liners are attached to the inner wall surface 1A of the fixed ring 1 and the dish surface 2A of the rotary dish 2, respectively.

The container 10 is provided with an inlet 35 for introducing a gas such as air,
Gas is introduced to cool the bearing box 4.

The crushing process of the crushing raw material by the wet centrifugal fluidizing crushing device configured as described above will be described below.

In the crushing chamber 20, a large number of crushing media composed of, for example, spherical balls are loaded in advance. First, a pulverized raw material prepared by mixing and stirring a liquid such as water at a fixed ratio is introduced into the apparatus from the introducing chute 8. The crushing raw material and the crushing medium are rotated along with the inner surface 1A of the stationary ring 1 and the plate surface.
A circular movement (arrow S) that circulates 2A and an orbital movement about the axis of the rotary plate 2 are combined to make a rope-like spiral movement (centrifugal flow), during which grinding material is ground or stripped. Take the money.

That is, when the rotary plate 2 is rotated, the grinding medium is moved in the outer peripheral direction by the centrifugal force, and the velocity energy crawls up the inner wall surface 1A of the fixed ring 1, and when the climbing force becomes smaller than gravity, the inner wall surface 1A. And falls on the plate surface 2A of the rotary plate 2. The grinding medium that has moved onto the dish surface 2A is again moved toward the fixed ring 1 along the dish surface 2A.

Further, when the rotary dish 2 is rotated, the grinding medium is removed from the rotary dish 2.
It revolves in the circumferential direction at a speed slower than the rotation speed of. Therefore, the crushing medium performs not only the circular motion S in the up-and-down direction which circulates the plate surface 2A and the inner wall surface 1A as described above, but also the revolution motion which rotates around the axis of the rotary plate 2. Performs a spiral movement (centrifugal flow) that twists the rope that synthesizes the movement.

In this way, the crushing medium makes a motion of climbing up the inner wall surface 1A while maintaining the movement of the rotary plate 2 in the circumferential direction. When the inner wall surface 1A is fixed, The combined speed of the directional speed (revolution speed) and the crushing speed of the grinding medium directly becomes the speed difference between the inner wall surface 1A and the grinding medium. Therefore, the speed difference between the crushing medium and the inner wall surface 1A becomes extremely large, and the grinding action by the action of the crushing medium when moving on the inner wall surface 1A becomes extremely strong.

Further, the pulverizing medium that has left the inner wall surface 1A and has landed on the dish surface 2A rolls down smoothly along the dish surface 2A, so that the inner wall surface 1A is moved by the motion of rolling down the dish surface 2A. It is possible to convert the potential energy obtained when running up to the kinetic energy in the radial direction, so that the energy once applied to the grinding medium can be effectively used for the peeling action without consuming it unnecessarily. . Furthermore, when descending along the dish surface 2A, the grinding medium slides on the dish surface 2A, so that grinding or peeling is performed even during this descending motion.

On the other hand, the solid-liquid two-phase fluid containing the fine powder pulverized in this way enters the container 10 from the pulverization chamber 20 through the through hole 2m, and is centrifuged by the action of the circulation vane 12 which swirls along with the rotation of the rotary plate. The force is applied, the minute gap 2n rises and the grinding chamber 20
Form a circulating flow back in. Therefore, the fluid is in the grinding chamber
Two circulation streams are formed: 20 circulation streams S and a circulation stream passing through the container 10. Therefore, as compared with the case where only the circulating flow in the crushing chamber 20 is used, the mixing of the fluid and the raw material fine powder is further promoted by the second circulating flow by the circulating blades, and the mixing is performed more uniformly. As a result, the crushing efficiency is improved. In addition, a product having a relatively narrow particle size distribution and a relatively narrow particle size distribution can be obtained.

Although the crushing progresses as described above, regarding the discharge of the material after the crushing is completed, the material is discharged from the discharge port 11 of the container 10 to complete one batch operation.

The weight ratio of the fluid such as water to the raw material is water: raw material = 2: 8.
From water to raw material = 8: 2, select appropriately considering the pulverizability of the raw material and the particle size of the final product.

A subsequent wet cyclone, a centrifugal classifier, or the like is used to classify particles in the fluid at the outlet.

[Effects of the Invention] As described above, in the wet centrifugal fluidizing and grinding apparatus of the present invention, a circulation flow through the container is formed separately from the circulation flow of the fluid in the rotary dish in the rotary dish. Therefore, the fluid and the fine powder are further mixed, and as a result, the mixing is uniform, so that the pulverization efficiency is improved and a product having a narrow particle size distribution is obtained.

[Brief description of drawings]

FIG. 1 is an overall vertical cross-sectional view of the apparatus of the embodiment, and FIG. 2 is a vertical cross-sectional view of an essential part showing another embodiment. 1 ... Stationary ring, 2 ... Rotating plate, 2m ... Through hole, 2n ... Minute gap, 1A ... Inner wall surface, 2A ... Plate surface, 3 ... Rotating shaft, 4 ... Bearing box, 8 ... … Injection chute, 9 …… Cradle, 10 …… Container, 11 …… Discharge port, 12 …… Circulating blade.

Claims (1)

(57) [Claims] 1. A rotation having a shape in which a rotation axis is oriented in a vertical direction, at least a central portion has a dish surface whose diameter is expanded downward, and a longitudinal cross section of the dish surface is curved in a concave shape. A freely rotatable circular dish and at least an upper portion having an inner wall surface whose diameter is reduced upward, and a vertical cross section of the inner wall surface is curved in a substantially concave shape, and is coaxial with the rotary dish. A stationary ring that is circumferentially provided and is stationary, and the plate surface of the rotary plate and the inner wall surface of the fixed ring have a continuous smooth surface except for a minute gap between the rotary plate and the fixed ring. The wet centrifugal fluidizing and pulverizing apparatus formed in the above, wherein a through hole is provided in the vicinity of the bottom of the rotary dish, and the solid-liquid two-phase fluid containing the powder of the material to be crushed is transferred to the lower surface of the outer periphery of the rotary dish. A circulation vane for use in the liquid is provided, and a container for the solid-liquid two-phase fluid and an outlet are provided below the rotary dish. Liquidity milling equipment.