JPH05345141A - Centrifugal fluidized grinding apparatus - Google Patents

Abstract

PURPOSE:To provide a centrifugal fluidized grinding apparatus capable of obtaining a fine powder of high purity reduced in contamination and aggregation and achieved in the extension of the life of the liner of its grinding chamber. CONSTITUTION:A freely rotatable rotary tray 6 having a tray surface 6a expanding in its diameter downwardly at the central part thereof and having a vertical cross section curved in a recessed shape and the outer peripheral ring 7 having an inner wall surface 7a contracted in its diameter upwardly and having a vertical cross section curved in a recessed shape and coaxially provided to the periphery of the rotary tray 6 to be stopped or reversed are provided. The common base plate 70 loaded with the rotary tray and the outer peripheral ring 7 is supported on a movable base plate 100 so as to be freely rotated around a vertical axis and a rotary drive means 90 is provided and the tilting means 130 of the movable base plate 100 connecting one end of the movable base plate 100 by a pin and moving the other end thereof up and down is provided.

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, inorganic or organic compounds, and more particularly, to a steel ball or 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 adapted to pulverize a raw material by centrifugally flowing a pulverizing medium such as.

[0002]

2. Description of the Related Art There are various types of crushing devices such as a tube mill and a vertical mill, but a steel plate or ceramics housed inside is installed by installing the rotating plate upward and rotating the rotating plate. Grinding media such as balls (hereinafter,
Called a ball. ) Is circulated to pulverize and grind the raw material, 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 pulverizing apparatus having a rotating dish and a fixed ring (peripheral ring) as follows. (Japanese Patent Application Nos. 60-265379 and 60-266)
867-266872, 61-99745, 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 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 plate surface of the rotary plate 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 plate 6 and the outer peripheral ring 7. Has been formed.

Reference numeral 8 is a casing that covers 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 is provided with a large number of slits or small holes 15 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, and an air introduction chamber 17 is formed between the side cover 16 and the outer surface of the casing 8 and the outer peripheral 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 dish 6 and the inner peripheral edge of the bottom portion 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 or granular material, and the pipeline 21 is arranged so that the powder or granular material 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 into the center of the top of the lid 28, and a bearing 29 pivotally supports the rotary cylinder 14. 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.

Then, the classifier 3 is attached to the lower end of the rotary cylinder 14.
0s are serially arranged. In this embodiment, the classifier 30 is erected on a pair of upper and lower rotating discs 31, 32, a first blade 33 sandwiched between the discs 31 and 32, and an edge of the disc 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) so as to rotate 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 content 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 and is returned to the crushing chamber 27 by the circulation fan effect of the second blade 34.

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 rotating dish 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 rotating plate 6. A "spiral movement" is performed, which is like twisting a rope by synthesis with movement, and the raw material is crushed in the meantime. Also,
From the air introducing pipe 18 to the air introducing 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 is subjected to 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 come out of 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. 5 as described above, the crushing chamber 2
Clearance is the fine powder in the crushed product crushed in 7.
It is conveyed to the classifier 30 together with the introduced gas, and is subjected to the classification action, and only the fine powder below the classification point is discharged out of the machine, and is collected by the collector to become a product. As described above, in the conventional centrifugal fluidized pulverizer, 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 contacting each other. As a result, the raw material introduced together with the balls can be efficiently pulverized, and ultrafine pulverized products with a low 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, resulting in contamination 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 expands downward, and the dish. The plate has a rotatable dish-shaped plate having a concave curved vertical cross section, and at least the upper part has an inner wall surface that decreases in diameter upward, and the vertical cross section of the inner wall is concavely curved. An outer peripheral ring that is coaxially provided around the rotary plate and is stationary or is driven to rotate in a direction opposite to the rotary plate, the plate surface of the rotary plate and the inner wall surface of the outer peripheral 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 the common platform on which the centrifugal fluidizing and pulverizing apparatus is mounted is a vertical shaft. The movable base is rotatably supported on the movable base, and the common base is provided with a rotation driving means. And configured to include the tilting means of the movable base block for vertically moving the pin junction by the other end to one end of the board.

[0015]

In the centrifugal fluidizing and crushing apparatus 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 dish surface of the rotary dish and the inner peripheral ring inner wall surface.
In addition, the balls and the raw material granules that circulate in a plane in the crushing chamber maintain a uniform centrifugal flow state in any cross section of the circumference, like a conventional centrifugal flow crusher with a vertical axis of rotation. However, since the amount of raw material in the crushing chamber on the descending side is larger than that in the crushing chamber on the ascending side, the forced motion due to the centrifugal force is weakened and the centrifugal flow crushing action 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, the contamination of the raw material powder with abrasion powder due to contamination is reduced. Moreover, when the agglomerated fine powder raw 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.

As described above, the centrifugal fluidizing and pulverizing apparatus of the present invention is inclined, and the centrifugal fluidizing and pulverizing action is more active on the ascending side of the pulverizing chamber than on the descending side. The inner liner of the outer ring wears quickly. To prevent such uneven wear, the common base is rotated at the required cycle.

[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 longitudinal sectional view of a centrifugal fluidizing and pulverizing apparatus, FIG. 2 is a longitudinal sectional view of main portions of the centrifugal fluidizing and pulverizing apparatus, and FIG. FIG. 4 is a correlation curve diagram with the amount of contaminants mixed in, and FIG. 4 is a correlation curve diagram with the average particle size of the product and the operating time.

In FIG. 1, the rotary disc 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 disc 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 finely or ultrafinely pulverized. A cap-shaped cylindrical tube 40 having a top plate 40 a is placed on the outer peripheral ring 7 and is connected to the outer peripheral ring 7. A partition plate 42 made of a horizontal disk 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 from the outside of the machine. Nozzle 6
0a is arranged to face the Venturi tube 46. Cylindrical tube 40
An exhaust 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 cylindrical protrusion 72 is provided on the lower surface of the common base 70, and the movable base 100 is rotatably rotatable via a thrust bearing 80 attached to the lower end of the common base 70. The gear 90 a mounted on the output shaft of the electric motor 90 fixed to the motor 100 and the gear 72 a mounted around the protrusion 72 are driven to rotate. A chain wheel transmission may be used instead of the gear. The one end of the movable base 100 is pin-joined to the fixed base 120 by a pin joint 110, and the other end of the movable base 100 is fixed to the fixed base 120 by a piston rod 130a of a hydraulic cylinder 130. The movable base 100 is joined by a pin joint 140 provided at the tip of the hydraulic cylinder 130, and the movable base 100 can take an arbitrary inclination angle θ by moving the piston rod 130a of the hydraulic cylinder 130 forward and backward. 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 revolution motion around the axis of the rotary plate 6. The rope is twisted in a spiral motion (centrifugal flow), and the ground material is ground or stripped in the meantime.
That is, when the rotating dish 6 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 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 onto the dish surface 6a is again moved toward the outer peripheral ring 7 along the dish surface 6a.

When the rotary plate 6 is rotated, the grinding medium revolves in the circumferential direction at a speed lower than the rotational speed of the rotary plate 6. Therefore, as described above, the crushing medium is the dish surface 6a.
In addition to the vertical circular movement S that circulates through the inner wall surface 7a and the revolving movement that rotates around the axis of the rotary plate 6, a spiral movement that twists the rope that combines these two movements ( 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 plate 6 in the circumferential direction. When the inner wall surface 7a is fixed, the crushing medium is The circumferential speed (revolution speed) and the combined speed of the crushing speed of the grinding 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 upper surface 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 grinding medium can be effectively used for the peeling action without consuming it unnecessarily. Further, when descending along the dish surface 6a, the grinding medium slides on the 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 balls 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 deviation of the material, when the balls on the ascending side and the raw material that are centrifugally flowing (spiral advancing motion) reach the descending side, they collide with many materials that are unevenly distributed on the descending side, and the conventional rule The conventional centrifugal flow motion is partially destroyed, and it is divided into the material that has the centrifugal flow type forced motion up to now and the material that has free motion 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 as in the conventional device, but the free motion is added to the forced motion. This free-moving material disturbs 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 balls and 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 attenuated accordingly, so that the centrifugal force acting on the material (ball and raw material) as a whole is weakened. As a result, surface peeling is slight and contamination is reduced. FIG. 3 shows the test results of the contamination amount M in the batch operation (batch operation). As a result of performing the test with a tilt angle θ = 15 °, whether the conventional type A and the tilt 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) and 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 the crushing a negative aspect of increasing the average particle diameter, but when it is inclined like the present invention, it descends. The material rushed to the side collides with many unevenly distributed materials and is crushed, so that the action of destroying the agglomerated state can be expected. 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 reduced and the average particle size was reduced.

Control of the ratio of the forced motion and the free motion in the tilt type device is performed by changing the tilt angle θ,
The tilt angle θ is set within the range of 5 ° to 30 °. The lower limit of 5 ° in the numerical limits 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 in the range of 10 ° to 20 °.

The apparatus of the present invention is a negative factor for crushing because the forced motion is somewhat suppressed, but it is most suitable especially when 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 a long time operation in batch operation, and in the case of continuous operation, reduce the input amount (processing amount kg / h) to obtain high purity. ， It is possible to obtain high-quality (ultrafine powder) products.

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 out of the machine unless it passes through the bag filter. Since it is not possible to do so, no coarse powder above the size of the mesh is mixed in 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 problem in driving.

The apparatus of the present invention is constructed as described above, the apparatus is inclined by the inclination angle θ, and the degree of centrifugal flow crushing action is different between the ascending side and the descending side of the crushing chamber, and the dish surface 6a of the rotary dish 6 is different. The inner wall surface 7a of the outer peripheral ring 7 is unevenly worn. Therefore, the common base 70 is rotated at an appropriate cycle, for example, about 1/8 to 1/4 about once every 2 hours to equalize the wear of the liner (the dish surface 6a and the inner wall surface 7a). In this way, the wear of the lining liner in the crushing chamber is leveled by a long-term operation, so that the life of the lining liner can be extended.

[0031]

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 grain size. Further, the wear of the lining liner in the crushing chamber is leveled, and the life can be extended.

[Brief description of drawings]

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

FIG. 2 is a longitudinal sectional view of a main part of a centrifugal fluidizing and crushing 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]

 1 Centrifugal Flow Grinding Device 2 Rotating Shaft 6 Rotating Plate 6a Dish Surface 7 Outer Ring 7a Inner Wall Surface 18 Air Introducing 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 Classifying chamber 48 Discharge pipe 50 Bag filter element 60 Compressed air supply pipe 60a Blow-out nozzle 70 Common bed 72 Protrusion 72a Gear 90 Motor 90a Gear 100 Movable bed 110 Pin joint 120 Fixed bed 130 Hydraulic cylinder 130a Piston rod 140 Pin joint A Conventional type B Inclined type M Contamination amount Dp Average particle size X Virtual surface θ Inclined angle

Claims (1)

[Claims] 1. A rotatable dish-shaped rotating dish having at least a central portion that has a dish surface that expands downward, and a longitudinal cross section of the dish surface that is concavely curved, and at least The upper part has an inner wall surface whose diameter decreases upward, and the vertical cross section of the inner wall surface is curved in a concave shape. An outer peripheral ring driven to rotate in a direction, and the plate surface of the rotary plate and the inner wall surface of the outer ring form a continuous smooth surface except for a minute gap between the rotary plate and the outer ring. A centrifugal fluidizing and pulverizing apparatus formed, wherein a common platform on which the centrifugal fluidizing and pulverizing apparatus is mounted is rotatably supported on a movable platform around a vertical axis, and a rotation driving means for the common platform is provided. 1 of the movable platform
A centrifugal fluidizing and pulverizing apparatus provided with a tilting means for the movable base plate, the ends of which are joined by pins and the other end of which is vertically moved.