JPH067698A - Centrifugal fluidization crusher - Google Patents

Abstract

PURPOSE:To provide a centrifugal fluidization crusher capable of obtaining a high-purity fine powder which is hardly contaminated or aggregated. CONSTITUTION:This centrifugal fluidization crusher is provided with a rotary disk 6 having a surface 6a with the diameter of the central part increased downward and with the longitudinal section concaved and a peripheral ring 7 having an inner wall surface 7a with the diameter decreased upward and with the longitudinal section concaved, provided coaxially around the disk 6, fixed or rotated in the backward direction. A means (fixed base 130, bevel gears 124 and 142, driving shaft 140, V pulley 160) for rotating a vertical shaft 110 having an engaging hole 110a is further furnished into which a spindle 100a projecting downward from a common base 100 on which the crusher is placed is inserted.

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 for pulverizing raw materials by centrifugally flowing a pulverizing medium such as.

[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 present applicant has applied for a patent for a centrifugal fluidizing and crushing device having a rotating dish and a fixed ring (peripheral ring) as described below. (Japanese Patent Application Nos. 60-265379 and 60-266)
867 to 266872, ibid. 61-99745, ibid. 6
1-207603).

FIG. 5 shows an embodiment of these centrifugal fluidizing and crushing devices. The rotating dish 6 has a rotating shaft centered in the vertical 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.

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, 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 ring 7 and the inner surface of the casing 8. An air introduction chamber 17 is formed between the side cover 16 and the outer surface of the casing 8 and the outer ring 7. The air can be introduced from the 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.

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 plate surface 6a, 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 flow crushing apparatus shown in FIG. 8 as described above, the crushing 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 put in together with the balls can be efficiently pulverized, and ultrafine pulverized products with a small degree of fineness can be efficiently produced. Increasing (mixing of wear members into products) has been an obstacle to obtaining high-quality products with high purity. In addition, centrifugal fluidization with a strong centrifugal force has a drawback that the fine powders produced are aggregated and the apparent average particle size of the fine powders becomes large.

[0014]

In order to solve the above-mentioned problems, the centrifugal fluidizing and crushing apparatus of the present invention has at least a central portion having a dish surface whose diameter is expanded downward, and the dish. A rotatable dish-shaped rotating dish whose surface has a concave curved longitudinal section, and at least an upper portion of which has an inner wall surface that reduces in diameter upward, and the inner wall surface has a vertically curved concave section. An outer peripheral ring that is provided around the rotary plate and is coaxial with the rotary plate and is stationary or rotationally driven in a direction opposite to the rotary plate, and the plate surface of the rotary plate and the inner wall surface of the outer ring. Is a centrifugal fluidizing and pulverizing apparatus formed on a continuous smooth surface except for a minute gap between the rotary dish and the outer peripheral ring, and a common table on which the centrifugal fluidizing and pulverizing apparatus is mounted and fixed. A vertical shaft provided with a support shaft projecting downward from the panel and having a fitting hole into which the support shaft is obliquely fitted with respect to the vertical direction. It was journaled, and a configuration with a rotary drive means for rotating 該鉛 straight axis vertical axis.

[0015]

In the centrifugal fluidizing and crushing device of the present invention, since the axis of rotation is inclined from the vertical direction, it vertically circulates and flows in the crushing chamber formed around the plate surface of the rotating dish and the inner peripheral ring inner wall surface.
Moreover, the balls and the raw material particles that circulate in a plane in the crushing chamber maintain a uniform centrifugal flow state in any cross section of the circumference, as in a conventional centrifugal flow crusher with a vertical axis of rotation. However, since there is more raw material in the crushing chamber on the descending side than the crushing chamber on the rising side, the forced motion due to the centrifugal force is weakened and the use in the centrifugal flow crushing chamber is suppressed.
As a result, the centrifugal action of moving the balls and the raw material powder along the wall surface while pressing it strongly against the wall face is reduced compared to the conventional one, and the peeling action of the wall face is reduced. Therefore, contamination of the raw material powder with abrasion powder due to contamination is reduced. In addition, when the agglomerated fine powder material moves to the crushing chamber on the descending side where many raw materials are densely packed, the regular forced flow seen in the conventional equipment is disturbed and collides with many of these raw materials to destroy the agglomerated state. As a result, the agglomeration is reduced and the fineness of the refined powder is reduced, resulting in a high quality product.

In the centrifugal fluidized crushing apparatus of the present invention, the center axis of the crushing chamber rotates at high speed, and at the same time the center axis itself precesses (gyro motion). The centrifugal fluidized grinding action is active, and uneven wear due to wear on the ascending side where the wear progresses quickly can be avoided.

[0017]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 to 4 relate to an embodiment of the present invention, FIG. 1 is an overall vertical sectional view of a centrifugal fluidizing and pulverizing apparatus, FIG. 2 is a longitudinal sectional view of a main portion of the centrifugal fluidizing and pulverizing apparatus, and FIG. FIG. 4 is a correlation curve diagram with the amount of contamination, and FIG. 4 is a correlation curve diagram with the average particle size of the product and the operation time.

In FIG. 1, the rotary plate 6 is connected to the output shaft of the speed reducer 25 via a rotary shaft 2 and a coupling 2a which are vertically provided below the center of the rotary plate 6, and a variable speed electric motor 26 is provided.
It is driven to rotate by. On the other hand, a small clearance 1
An outer peripheral ring 7 is disposed around the rotary plate 6 with a column base 24 and a pedestal 23 separated by 9, and in the crushing chamber 27 which is a space formed by the rotary plate 6 and the outer peripheral ring 7, the conventional technology is used. The raw material configured as described above is subjected to centrifugal fluidizing and pulverizing action by a pulverizing medium, and is pulverized or ultrafine pulverized. A cap-shaped cylindrical tube 40 having a top plate 40 a is placed on the upper part of the outer peripheral ring 7 and connected to the outer peripheral ring 7. A partition plate 42 made of a horizontal disc having a plurality of through holes 44 is fixedly provided in the middle of the cylindrical tube 40.
The bag filter element 50 is provided in the through hole 44 with the partition plate 4
It is arranged so as to project and hang down in a classification chamber 47 formed below 2. Further, a venturi pipe 46 is provided above the through hole 44, and a compressed air supply pipe 60 for blowing compressed air to the inner surface of the bag filter element 50 is guided from above the venturi pipe 46 and blown out. Nozzle 6
0a is arranged to face the Venturi tube 46. Cylindrical tube 40
A discharge pipe 48 for dust-containing gas is provided at the center of the top plate 40a. The variable speed electric motor 26, the speed reducer 25, and the column base 24 configured as described above are fixedly mounted on the upper surface of the common base 70.
A support shaft 100 a projects from the bottom surface of the movable base 100 at right angles to the movable base 100. Then, the fixed base 130 has a thrust bearing 134, a bush 132, and a bush 12.
The support shaft 100a is fitted into a fitting hole 110a provided obliquely in the axial direction of the vertical shaft 110 that is vertically supported via the shaft 2, and is prevented from rotating by the key 112. Vertical axis 110
The boss 120 on the outer circumference of the upper half is rotated around the vertical shaft center by the rotational drive of the drive shaft 140 and the V pulley 160 supported by the bearing 150 via the engagement of the bevel gear 124 and the bevel gear 142 together with the vertical shaft 110. It is driven to rotate. On the other hand, the support 20
0a is attached to the pantograph 200, and the annular slip ring 210 connected to the power wiring 220 is arranged on the extension of the axis Z of the vertical shaft 110 and is constantly in contact with the biasing force of the spring 200b. The connection wiring with the electric motor 26 ensures the power of the centrifugal fluidizing and pulverizing apparatus 1 that rotates during operation. The centrifugal fluidizing and pulverizing apparatus 1 of the present invention is capable of both intermittent operation (batch operation) and continuous operation, and has wide versatility.

The operation of the present invention configured as above will be described. In the crushing chamber 27, a large number of crushing media composed of, for example, spherical balls are loaded in advance. First, the crushed raw material is charged into the apparatus through a charging tube (not shown). A combination of a circular motion (arrow S) in which the crushing raw material and the crushing medium circulate between the inner wall surface 7a of the outer peripheral ring 7 and the plate surface 6a along with the rotation of the rotary plate 6 and the revolving motion around the axis of the rotary plate 6. A spiral movement (centrifugal flow) is carried out, which causes the rope to twist, and the ground material is ground or stripped in the meantime.
That is, when the rotating dish 6 is rotated, the crushing medium is moved in the outer peripheral direction by the centrifugal force, and the velocity energy crawls up the inner wall surface 7a of the outer peripheral ring 7, and when the creeping force becomes smaller than gravity, It separates from the inner wall surface 7a and falls on the dish surface 6a of the rotary dish 6. The grinding medium that has moved to the dish surface 6a is again moved toward the outer peripheral ring 7 along the dish surface 6a.

When the rotary dish 6 is rotated, the grinding medium revolves in the circumferential direction at a speed lower than the rotational speed of the rotary dish 6. Therefore, as described above, the crushing medium is the dish surface 6a.
In addition to the vertical circular motion S that circulates along the inner wall surface 7a and the orbital motion that rotates around the axis of the rotary plate 6, a spiral progressive motion that twists the rope combining these two motions ( Centrifugal flow).

As described above, the crushing medium performs the movement of climbing up the inner wall surface 7a while maintaining the movement of the rotary tray 6 in the circumferential direction. When the inner wall surface 7a is fixed, the crushing medium is The circumferential speed (revolution speed) and the composite speed of the crushing speed of the crushing medium are the same as the inner wall surface 7a.
And the speed difference of the grinding media. Therefore, the speed difference between the crushing medium and the inner wall surface 7a becomes extremely large, and the grinding action by the action of the crushing medium when moving on the inner wall surface 7a becomes extremely strong.

Further, the plate surface 6a is detached from the inner wall surface 7a.
Since the crushing medium that has landed on the top smoothly rolls down along the dish surface 6a, the potential energy obtained when running up the inner wall surface 7a in the radial direction is obtained by the motion of rolling down the dish surface 6a. Since it can be converted into kinetic energy to, the energy once applied to the pulverizing medium can be effectively used for the peeling action without consuming it unnecessarily. Furthermore, when descending along the dish surface 6a, the grinding medium slides on this dish surface 6a, so that grinding or peeling is performed even during this descending movement.

The behavior of the balls and the raw materials in the crushing chamber 27 described above is substantially uniform at any position on the circumference of the crushing chamber 27 in the conventional centrifugal flow crushing apparatus having the vertical axis of rotation. However, in the inclined type apparatus of the present invention in which the axis of rotation is not vertical, the behavior of each cross section of the circumference is not uniform. That is, as shown in FIG. 2, since the device is tilted by an inclination angle θ from the vertical, the raw material in the crushing chamber 27 is not evenly distributed around the circumference, and when the ball and the raw material are regarded as liquids. As shown by the virtual surface X, more balls and raw materials are unevenly distributed in the crushing chamber 27 on the descending side (right side in FIG. 2) than on the ascending side (left side in FIG. 2). Therefore, due to the bias of this material, when the above-mentioned balls on the ascending side and the raw material that have undergone centrifugal flow (spiral advancing motion) reach the descending side, they collide with many materials that are unevenly distributed on the descending side, and the conventional rules The partial centrifugal flow motion is destroyed, and it will be divided into materials that have been used for centrifugal flow type forced motion up to now and materials that will move freely after collision. afterwards,
Among the materials on the descending side, the material directed to the ascending side again performs the centrifugal flow type forced motion by the centrifugal force applied by the rotation of the rotary plate. As described above, in the device of the present invention, the forced motion is not uniform all around like the conventional device, but is a motion in which free motion is added to the forced motion. This free-moving material disturbs the regular forced motion (centrifugal flow motion) and slows down the forced motion.

On the other hand, as described above, the plate surface 6 of the rotary plate 6
When the balls and the raw materials flow on the inner wall surface 7a of the outer ring 7a or the outer ring 7, peeling occurs by sliding on the dish surface 6a and the inner wall surface 7a. At the same time, the surface of the ball itself is peeled off. These peeled fine particles are mixed in the product and become impurities to deteriorate the quality of the product. These phenomena are called contamination.

However, in the apparatus of the present invention, the apparatus is tilted and free movement is imparted on the descending side of the crushing chamber, and the forced movement is reduced by that amount, so that the centrifugal force acting on the material (ball and raw material) is weakened as a whole. As a result, surface peeling is slight and contamination is reduced. FIG. 6 shows the test results of the contamination amount M in the batch operation (batch operation). As a result of performing the test with the inclination angle θ = 15 °, whether the conventional type A and the inclined type B change linearly with the passage of time, In the inclined type, the contamination amount M is almost halved. In particular, in equipment that uses ceramic balls (such as zirconia) or liners, the surface layer of the ceramic thin film is harder and more wear-resistant than the interior, so peeling is limited to this surface layer. By doing so, it is possible to further reduce the contamination phenomenon.

Further, the finely pulverized fine powder is liable to agglomerate when it becomes about 5 μm or less, which gives a negative surface to the pulverization that the average particle diameter is increased, but when it is inclined like the present invention, it is lowered. It is expected that the material rushed to the side will collide with many unevenly distributed materials and be crushed to destroy the agglomerated state. Also in this case, as a result of the batch test, as shown in FIG. 4, in the inclined type, the degree of agglomeration was decreased, and the average particle size was decreased.

Control of the ratio of the forced motion to the free motion in the tilt type device is performed by changing the tilt angle θ of the fitting hole 110a of the vertical shaft 110, and the tilt angle θ is set in the range of 5 ° to 30 °. Therefore, several types of vertical shafts 110 having different inclination angles θ are prepared. The lower limit of 5 ° in the numerical limit is because there is almost no tilt effect below this, and on the contrary, when the maximum value exceeds 30 °, the forced motion (centrifugal flow motion) itself is obstructed and the originally intended crushing cannot be performed. It was found from various test results.
The desirable range of the inclination angle θ is 10 ° to 20 °.

The device of the present invention is a negative factor for crushing because the forced motion is somewhat suppressed, but it is most suitable for the case where a high-purity product that is resistant to contamination is required, and since agglomeration is small, it is high. If you want to obtain only a small amount of ultra-fine powder product with high purity, you can obtain it in batch operation for a long time, and in continuous operation, reduce the input amount (processing amount kg / h) to obtain a high purity seat. , High quality (ultra fine powder) products can be obtained.

Further, in the embodiment of the present invention, a bag filter element having a sieve mesh matching a desired product particle size is installed in the classification chamber in the upper part of the apparatus, and dust-containing gas is discharged to the outside of the machine unless it passes through the bag filter. Since it is not possible to prevent this, coarse powder above the sieve mesh will not be mixed into the product. Therefore, it is possible to prevent the coarse powder from being mixed into the product. In addition, since a compressed air supply pipe for backwashing is installed, it is possible to clean the sieve mesh of the bag filter that has been clogged during operation and to drop the coarse powder adhering to the outer surface of the bag filter for re-grinding. There is no obstacle to driving.

[0030]

As described above, the centrifugal fluidizing and crushing apparatus of the present invention can obtain a high-purity product with less contamination and fine powder with less aggregation of crushed refined powder. Therefore, it is possible to provide a high-quality finely pulverized product having a particularly small product particle size.

[Brief description of drawings]

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

FIG. 2 is a longitudinal sectional view of a main part of a centrifugal fluidizing and pulverizing apparatus showing an embodiment of the present invention.

FIG. 3 is a correlation curve diagram between the operating time and the amount of contamination mixed in the product in the centrifugal fluidizing and pulverizing apparatus.

FIG. 4 is a correlation curve diagram between an average particle size of a product and an operation time by a centrifugal fluidizing and pulverizing device.

FIG. 5 is a longitudinal sectional view of a main part of a conventional centrifugal fluidizing and pulverizing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Centrifugal fluid pulverizer 2 Rotating shaft 6 Rotating dish 6a Dish surface 7 Outer ring 7a Inner wall surface 18 Air inlet tube 19 Clearance 27 Grinding chamber 40 Cylindrical tube 40a Top plate 40b Cylindrical tube 40c Lid 40d Hinge 42 Partition plate 44 Through hole 46 Venturi pipe 47 Classification chamber 48 Discharge pipe 50 Bag filter element 60 Compressed air supply pipe 60a Blow-out nozzle 100 Movable base 100a Spindle 110 Vertical shaft 110a Fitting hole 112 Key 120 Boss 122 Bush 124 Bevel gear 130 Fixed base 132 Bush 134 Thrust bearing 140 Drive shaft 142 Bevel gear 150 Bearing 160 V pulley 200 Pantograph 200a Support 200b Spring 210 Slip ring 220 Power wiring A Conventional type B Inclined type M Contamination amount Dp Average particle size X Virtual surface θ Inclination Oblique angle Z vertical axis

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 direction, and the dish surface of the rotary plate and the inner wall surface of the outer peripheral ring form a continuous smooth surface except for a minute gap between the rotary plate and the outer peripheral ring. A centrifugal fluidizing and crushing device formed, wherein a supporting shaft projecting below a common platform on which the centrifugal fluidizing and crushing device is mounted and fixed is provided, and the supporting shaft is fitted obliquely to the vertical direction. Centrifugal flow pulverizing device bearing a vertical shaft having a fitting hole for rotating the vertical shaft and rotating the vertical shaft around a vertical axis. .