JPH078821A - Centrifugal fluidized pulverizer - Google Patents

Abstract

PURPOSE:To provide a centrifugal fluidized pulverizer where high pulverizing efficiency is obtained in superfine pulverization by grinding and products of high quality having little contamination due to the abrasion of the pulverizing surface are obtained. CONSTITUTION:In a centrifugal fluidized pulverizer 1A where a raw material is fed together with balls to give the material superfine pulverization into a freely rotatable recessed rotating bowl 6 and an outer peripheral ring 7 whose inner wall surface is curved in a recess and which is circumferentially and coaxially installed with the rotating bowl 6, abrasion resistant liners 6a, 7a are stuck on the surface of the rotating bowl 6 and the inner wall surface of the outer peripheral ring 7 through elastic bodies 6b, 7b in the shape of a curved plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crushing device for finely crushing ceramics or an inorganic or organic compound, and more specifically, to a steel ball or a ceramics ball equipped with a rotating dish and an outer peripheral ring and housed inside the device. The present invention relates to a centrifugal fluidizing and pulverizing apparatus which pulverizes or grinds a raw material by centrifugally flowing a pulverizing medium such as a pulverizing medium. The present invention relates to a centrifugal fluidizing and grinding apparatus intended to reduce contamination caused by wear.

[0002]

2. Description of the Related Art There are various types of crushing devices such as tube mills and vertical mills, but the steel balls or ceramics housed inside are installed by placing the rotary plate upward and rotating the rotary plate. Grinding media such as balls (hereinafter,
Called a ball. ) Is circulated to pulverize and grind raw materials, which is commonly known as a vertical ball mill.

In this type of vertical ball mill that has been used for a long time, 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 was a problem. Therefore, the applicant of the present invention has filed a patent application for a centrifugal fluidizing and pulverizing device having a rotating dish and a fixed ring (peripheral ring) as described below (Japanese Patent Application Nos.
67-266872, 61-99745, 61.
-207603).

FIG. 4 shows an embodiment of these centrifugal fluidizing and crushing devices. The rotating dish 6 has a rotating shaft centered in the longitudinal direction, and at least a central portion of the dish surface expands downward. And has a shape in which the longitudinal cross section of the dish surface is curved in a concave shape and is rotatable. The outer peripheral ring 7 has an inner wall surface in which at least the upper part is reduced in diameter upward,
The inner wall surface has a shape in which a vertical cross section is curved in a concave shape, and is coaxially provided around the rotary plate 6 and is stationary. In the centrifugal fluidizing and crushing device 1, the dish surface of the rotary dish 6 and the inner wall surface of the outer peripheral ring 7 form a continuous smooth surface except for the minute gap 19 between the rotary dish 6 and the outer peripheral ring 7. Has been formed. A liner 6 a is attached to the surface of the rotary dish 6.

Reference numeral 8 is a casing for covering the main body of the crusher, and the outer peripheral ring 7 is attached to the inner surface of the casing 8 via a connecting member 9. Reference numeral 10 is a column base, which pivotally supports the rotating dish 6 via a bearing 11.
The rotating shaft 2 is connected to a prime mover such as an electric motor via a reduction mechanism. At the center of the ceiling of the casing 8, a raw material feeding pipe 12 is installed, and a duct 13 is provided so as to surround the feeding pipe 12, and a rotary cylinder 14 is connected to the duct 13.

In this embodiment, the outer peripheral ring 7 is lined with a liner 7a, and a large number of slits or small holes 15 are formed so as to penetrate the wall surface thereof. A side cover 16 is provided between the bottom of the outer surface of the outer peripheral ring 7 and the inner surface of the casing 8.
Is provided around the side cover 16 and the casing 8.
An air introduction chamber 17 is defined between the outer peripheral ring 7 and the outer surface of the outer peripheral ring 7, and air can be introduced from an air introduction pipe 18. The upper end of the side cover 16 is sealed to the outer side surface of the outer peripheral ring 7. The liner 7a, like the liner 6a,
As shown in FIG. 5, it is attached to the outer peripheral ring 7 by an epoxy adhesive 7x.

On the other hand, there is a clearance 19 of 10 to 30% of the minimum ball diameter between the outer peripheral edge of the rotary plate 6 and the inner peripheral edge of the bottom of the outer peripheral ring 7, and the bottom cover 20 is below this clearance 19. It is installed so as to cover the side. In this embodiment, air can be introduced into the bottom cover 20 by forming a through hole in the side cover 16 or connecting an air introduction pipe. The bottom cover 20 and the air introduction chamber 17 are connected to a pipeline 21 for extracting and transporting the powder and granules, and the pipeline 21 is arranged so that the powder and the granules can be returned to the charging pipe 12. . Also,
A scraper 22 is fixedly provided on the lower side of the outer peripheral edge of the rotary dish 6, and is configured to collect the powder particles falling in the bottom cover 20 toward the connecting portion of the pipe line 21 for extraction.

The lid 2 covers the upper surface of the casing 8.
8 are provided. The rotary cylinder 14 is inserted in the center of the top of the lid 28, and is rotatably supported by a bearing 29. The rotary cylinder 14 is connected to a drive device (not shown) by an appropriate power transmission means such as a pulley 29a and a belt 29b. The upper end of the rotary cylinder 14 and the lower end of the duct 13 are rotatably connected by a connecting mechanism.

At the lower end of the rotary cylinder 14, the classifier 3 is attached.
0s are serially arranged. In this embodiment, the classifier 30 is erected on a pair of upper and lower rotating disks 31, 32, a first blade 33 sandwiched between the edges of the disks 31, 32, and an edge of the disk 31. The second blade 34 and the third blade 35 are provided vertically on the edge of the disc 32. A stirring blade 36 is provided so as to surround the classifier 30. The blade 36 is connected to the discs 31 and 32 via a stay (not shown), and is rotated together with the classifier 30.

In the classifier 30, the air containing the pulverized material is classified by the first blade 33 after the particles are dispersed by the third blade 35 and the stirring blade 36, and the fine powder is divided into the disc 31, It flows into the center between 32 and is withdrawn to the rotary cylinder 14. On the other hand, the coarse powder classified by the first blade 33 flows along the inner surface of the lid 28 by the circulation fan effect of the second blade 34 and is returned to the crushing chamber 27.

In the crushing device configured as described above,
The raw material is charged into the crushing chamber 27 through the charging pipe 12. On the other hand, as the rotary disc 6 rotates, the grinding medium (steel balls or ceramic balls) circulates in the grinding chamber 27 between the outer peripheral ring 7 and the rotary plate 6 and revolves around the axis of the rotary plate 6. A "spiral motion" is performed, which is like a rope by the combination with motion, and the raw material is crushed in the meantime. Also,
From the air introduction pipe 18 to the air introduction chamber 17 and the bottom cover 2
The air introduced into 0 passes through the clearance 19, the slits or the small holes 15 into the crushing chamber 27, reaches the classifier 30 with the powder generated by the crushing, undergoes the classifying action, and undergoes the coarse powder. The fine particles are returned to the crushing chamber 27 again, and the fine particles are sent to the collecting means via the rotary cylinder 14 and the duct 13.
It is collected by a collector.

Further, the particles that have exited from the crushing chamber 27 through the slits or small holes 15 or the clearance 19 are returned to the crushing chamber 27 by the conduit 21 and the charging pipe 12.

[0013]

In the conventional centrifugal fluidized grinding apparatus shown in FIG. 4 as described above, the grinding chamber 2
Clearance of fine powder in the crushed product crushed in 7
It is conveyed to the classifier 30 along with the introduced gas, and is subjected to the classifying action, and only the fine powder below the classifying point is discharged out of the machine and is collected by the collector to become a product. As described above, in the conventional centrifugal fluidizing and pulverizing device, the central axis of the device, including the central axis of the rotating dish, is vertical, and the high speed rotation of the rotating dish causes the balls in the device to receive a strong centrifugal force and to be strong against the outer ring. While being rolled, it rolls or slides on the outer peripheral wall surface, and the frictional force due to the speed difference also acts on each ball that contacts each other. As a result, the raw material introduced together with the balls can be efficiently pulverized, and ultra-fine pulverized products with a small degree of fineness can be efficiently produced, but on the other hand, the wear of the balls, the outer peripheral ring, and the liner liner of the rotary dish is large and the contamination is large. Increasing (mixing of wear members into products) was an obstacle to obtaining high-quality products with high purity. Also, in a centrifugal fluidizing and crushing device, a large centrifugal force is applied to the ball by high-speed rotation, so the ball often collides with the lining liner, and when it collides, the repulsive force after the ball comes into contact with the liner is too strong. Centrifugal force is not converted into attrition force effective for fine pulverization, but it is changed into impact force in many cases, and there is a problem that the pulverization effect of ultrafine pulverized products is diminished.

[0014]

SUMMARY OF THE INVENTION In order to solve these problems and to provide a centrifugal fluidized crushing apparatus with less contamination and further improved ultrafine grinding by grinding, the present invention provides: , At least a central portion having a dish surface that expands downward, and a rotatable dish-shaped rotating dish having a shape in which the longitudinal cross section of the dish surface is concavely curved; Has an inner wall surface that decreases in diameter, and the longitudinal cross section of the inner wall surface is curved in a concave shape. The inner wall surface is provided coaxially with the rotary plate and is stationary or driven to rotate in a direction opposite to the rotary plate. A centrifuge having an outer peripheral ring that is formed, and the dish surface of the rotating dish and the inner wall surface of the outer ring are formed into a continuous smooth surface except for a minute gap between the rotating dish and the outer ring. A fluidized crushing device, which is a curved plate on the surface of the rotating dish and the inner wall surface of the outer peripheral ring. It has a structure that affixed to liner for wear by an elastic body is interposed.

[0015]

In the centrifugal fluidizing and crushing apparatus of the present invention, the inner liner is not directly attached to the outer peripheral ring or the surface of the rotary plate, but the sheet-like elastic body is interposed and then the inner liner is attached. When a collision occurs, the elastic body is deformed, and the deformed state changes following the movement of the ball rolling or sliding along the lining liner surface. Therefore, the ratio of the energy of the impact force lost during a collision to the centrifugal force applied to the ball decreases, and the ratio of the attrition force generated during the subsequent movement along the liner surface increases accordingly. However, the pulverization efficiency of the ultrafine pulverization is improved, and the contamination caused by the peeling or falling of the ball or liner surface caused by the impact is reduced.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 to 3 relate to an embodiment of the present invention,
FIG. 1 is an overall vertical cross-sectional view of the centrifugal fluidizing and pulverizing apparatus, FIG. 2 is an enlarged vertical sectional view of a main part of the centrifugal fluidizing and pulverizing apparatus, and FIG. 3 is an explanatory view of the behavior of the liner liner at the time of ball contact. The structure of the centrifugal fluidizing and pulverizing apparatus 1A of the present invention has substantially the same structure as that shown in FIG. 4. Explaining different points, as shown in FIG. 2, a curved surface is formed between the rotary plate 6 and the liner 6a. The sheet-like elastic body 6b is interposed, and the outer peripheral ring 7 and the liner 7a are lined.
Similarly, a curved plate-shaped elastic body 7b is also interposed between and. The elastic bodies 6b and 7b are made of soft rubber or sponge-like resin, and are bonded to the rotating dish 6 and the outer peripheral ring 7 of the main body with an adhesive, and the elastic bodies 6b and 7b and the liner 6a and 7a are pressure bonded. To join. In the embodiment of FIG. 1, the inner liners 6a and 7a are alumina liners having a thickness of 3 mm, and the elastic bodies 6b and 7b are nitrile rubber molded products having a thickness of 2 mm. In addition to the pre-molded rubber product, a liquid material may be poured into the inner surface of the inner liners 6a and 7a by using an appropriate frame. In the embodiment of FIG. 1, the elastic bodies 6b and 7b are attached to almost the entire surface of the rotary dish 6 and the outer peripheral ring 7, but they may be selectively attached to a part of the crushing surface.

In the centrifugal fluidizing and crushing apparatus 1A of the present invention in which the liner is attached with the elastic body interposed as described above,
As shown in FIG. 3, when the ball B collides with the lining liner 7a, the elastic body 7b elastically deforms to sink the lining liner 7a, and the impact repulsion force is reduced.
From the state of (a) to the state of FIG. 3 (b), the ball B
Is moved up along the surface of the liner 7a, the deformation of the elastic body 7b is released and the original state is restored. Therefore, a part of the impact force is converted into the grinding energy of the ball B (or the ball group containing the raw material powder) rolling or sliding on the liner surface, and the impact is larger than that of the conventional structure in which the lining liner is fixed to the main body. Since the force is reduced and the attrition force is increased, the pulverizing effect of the ultrafine pulverization which depends on the attrition force as in the device of the present invention is further improved. According to the test results, an improvement in crushing capacity of about 15 to 20% is observed as compared with the conventional one. In addition, as a result of the peeling and detachment of the ball and liner surface caused by the impact being reduced, contamination is reduced.

In order to confirm the above effect, the test machine CF
A wear confirmation test was performed using 1000 (rotor diameter 1000 mm). The test method is to put only 140kg of alumina balls (sphere diameter 15mm) in the above test machine.
After running for 20 hours at 60 rpm, the machine was stopped and the maximum wear depth of the liner surface was measured. The results are shown in Table 1.

[0019]

[Table 1]

As can be seen from this result, liner wear is drastically reduced due to the cushioning effect of the elastic body, and a significant reduction in contamination can be expected.

[0021]

As described above, in the apparatus of the present invention, since the liner is attached to the main body via the cushion material, the pulverization efficiency of ultrafine pulverization is increased and the surface of the ball or liner is removed. Since the resulting contamination is reduced, a high-quality product with high purity can be obtained.

[Brief description of drawings]

FIG. 1 is an overall vertical cross-sectional view of a centrifugal fluidizing and crushing apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged vertical cross-sectional view of a main part of a centrifugal fluidizing and pulverizing apparatus according to an embodiment of the present invention.

FIG. 3 is an explanatory view of the behavior of the liner liner at the time of ball contact in the centrifugal fluidizing mill according to the embodiment of the present invention.

FIG. 4 is an overall vertical cross-sectional view of a conventional centrifugal fluidizing and grinding apparatus.

FIG. 5 is an explanatory diagram of how to install a liner liner in a conventional centrifugal fluidized pulverizer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Centrifugal fluid pulverizer 1A Centrifugal fluid pulverizer 2 Rotating shaft 6 Rotating dish 6a Inner liner 6b Elastic body 7 Outer ring 7a Inner liner 7b Elastic body 7x Epoxy adhesive 18 Air introduction pipe 19 Clearance 27 Grinding chamber 30

Claims (1)

[Claims] 1. A rotatable dish-shaped rotating dish having at least a central portion having a dish surface that expands downward, and a longitudinal cross section of the dish surface curved concavely, and at least The upper part has an inner wall surface whose diameter decreases upward, and the longitudinal cross section of the inner wall surface is curved in a concave shape. The inner wall surface is coaxial with the rotary plate and is stationary or reverse to the rotary plate. An outer peripheral ring that is driven to rotate in a predetermined direction, and the dish surface of the rotary dish and the inner wall surface of the outer peripheral ring form a continuous smooth surface except for a minute gap between the rotary dish and the outer peripheral ring. A centrifugal fluidizing and pulverizing apparatus in which a wear resistant liner is attached to the surface of the rotary dish and the inner wall surface of the outer peripheral ring with a curved plate-like elastic body interposed therebetween.