JP2790229B2 - Operation method of centrifugal fluidized crusher - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulverizing apparatus for finely pulverizing ceramics or inorganic or organic compounds, and more particularly, to a steel ball or a ceramic ball provided with a rotating plate and an outer ring and housed inside the apparatus. The present invention relates to an operation method of a centrifugal fluidized pulverizer in which raw materials are continuously pulverized by centrifugally flowing a pulverizing medium.

[0002]

2. Description of the Related Art There are various types of pulverizers such as a tube mill and a vertical mill. A rotating plate is placed upward and the rotating plate is rotated to store steel balls or ceramics contained therein. Grinding media such as balls
It is called a ball. ) Is generally known as a vertical ball mill in which raw materials are crushed and ground by circulating motion.

[0003] In this type of vertical ball mill which has been used for a long time, the crushing and grinding actions are weak, or the energy input to the apparatus is easily consumed in addition to the crushing and grinding actions, and the energy efficiency is low. There was a problem. Accordingly, the present applicant has filed a patent application for a centrifugal flow pulverizer having a rotating dish and a fixed ring (outer ring) as described below. (Japanese Patent Application Nos. 60-265379 and 60-266)
867-266872, 61-99745, 6
No. 1-207603).

FIG. 5 shows an example of such a centrifugal fluidized crusher. The rotating plate 6 has a conical dish surface 6a whose rotating shaft is oriented vertically and whose diameter increases downward. And the vertical cross section of the plate surface 6a extends from the center to the outer periphery.
It is a rotatable dish-shaped thing which has a concavely curved shape. The outer peripheral ring 7 has at least an inner wall surface whose upper part is reduced in diameter upward, the longitudinal cross section of the inner wall surface is concavely curved, and is provided coaxially with the rotating plate 6. It is stationary. The centrifugal fluidized crusher 1 is configured such that the plate surface 6a of the rotating plate 6 and the inner wall surface of the outer peripheral ring 7 have a continuous smooth surface except for a minute gap 19 between the rotating plate 6 and the outer peripheral ring 7. Is formed.

[0005] Reference numeral 8 denotes a casing that covers the main body of the pulverizer, and an outer peripheral ring 7 is attached to the inner surface of the casing 8 via a connecting member 9. Reference numeral 10 denotes a column base, which pivotally supports the rotating plate 6 via a bearing 11.
The rotating shaft 2 is connected to a driving device such as an electric motor via a reduction mechanism or the like. At the center of the ceiling of the casing 8, there is provided a feed pipe 12 for the raw material, and a duct 13 is provided so as to surround the feed pipe 12, and a rotary cylinder 14 is connected to the duct 13.

In the present embodiment, the outer ring 7 is lined with a liner, and is provided with a number of slits or small holes 15 so as to penetrate the wall surface. A side cover 16 is provided between the bottom 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, the casing 8 and the outer surface of the outer peripheral ring 7. Thus, air can be introduced from the air introduction pipe 18.
The upper end of the side cover 16 is sealed to the outer surface of the side of the outer peripheral ring 7.

On the other hand, a clearance 19 of 10 to 30% of the minimum ball diameter is provided between the outer peripheral edge of the rotating plate 6 and the inner peripheral edge of the bottom of the outer peripheral ring 7, and the bottom cover 20 is located below the clearance 19. It is provided 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 pipe 21 for extracting and transporting the powder, and the pipe 21 is arranged so that the powder can be returned to the input pipe 12. . Also,
A scraper 22 is fixed to the lower side of the outer peripheral edge of the rotating plate 6, and is configured to collect powder particles falling into the bottom cover 20 toward a connection portion of a pipe 21 for extraction.

[0010] The lid 2 is so covered as to cover 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 is pivotally supported by a bearing 29. The rotary cylinder 14 is connected to a driving device (not shown) by 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.

A classifier 3 is provided at the lower end of the rotary cylinder 14.
0 is continuously provided. 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. A second blade 34 and a third blade 35 vertically provided at an edge of the disk 32. Further, 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 rotates 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. It flows into the center between 32 and is extracted 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 returns to the crushing chamber 27 by the circulation fan effect of the second blade 34.

In the crushing device thus configured,
The raw material is charged into the crushing chamber 27 from the charging pipe 12. On the other hand, as the rotating plate 6 rotates, the grinding medium (steel ball or ceramic ball) 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 combines a movement with a movement, and the raw material is crushed during that time. Also,
From the air introduction pipe 18 to the air introduction chamber 17 and the bottom cover 2
The air introduced into the chamber 0 flows into the crushing chamber 27 through the clearance 19, the slit or the small hole 15, and reaches the classifier 30 with the powder generated by the crushing. The fines are returned to the crushing chamber 27 again, and the fines are sent to the collecting means via the rotary cylinder 14 and the duct 13.
Collected in the collector.

The particles that have escaped from the crushing chamber 27 through the slits or small holes 15 or the clearance 19 are returned into the crushing chamber 27 by the conduit 21 and the charging pipe 12.

[0013]

In the conventional centrifugal fluidized grinding apparatus shown in FIG. 5 as described above, zirconia, alumina, silicon carbide, silicon nitride, steel balls, etc. are used as grinding media, However, in an apparatus having a diameter of 400 to 500 mm, a ball having a diameter of 10 mm is usually used and the rotation speed of a rotating dish is generally set to 500 rpm. In order to obtain an ultra-fine pulverized product in which the required fineness of the product to be pulverized is severe, a batch operation that can lengthen the pulverization time rather than a continuous operation is adopted. Although the operation was performed, every time the batch operation was completed, setup time such as removal of products and supply of crushing material was required, and there were drawbacks such as low productivity. The method of the present invention solves these problems and provides a good pulverization method for efficiently producing a product having a desired product particle size even in continuous operation and improving productivity.

[0014]

In order to solve the above-mentioned problems and to carry out effective pulverization and continuously obtain required ultra-fine pulverized products, the method of operating the centrifugal fluidized pulverizer of the present invention is as follows. A rotating shaft center is oriented vertically, has a dish surface having a conical shape whose diameter increases downward, and a longitudinal section of the dish surface is concavely curved from a central portion to an outer peripheral portion . A rotatable dish-shaped rotating dish having a shape, and at least an upper portion having an inner wall surface whose diameter is reduced upward, and a longitudinal section of the inner wall surface is concavely curved, and is coaxial with the rotating dish. An outer peripheral ring that is provided around the rotating plate and is stationary, and the surface of the rotating plate and the inner wall surface of the outer peripheral ring are continuously smooth except for a minute gap between the rotating disk and the outer peripheral ring. In the continuous operation of the centrifugal fluidized crusher formed on the surface, the crushed raw material and 600rp grinding media for storing the turntable rotational speed with a diameter in the case where the average particle diameter is desired to obtain more product 5μm has a less diameter ball 3mm in
m and a medium diameter or large diameter ball with a diameter of 5 to 10 mm and a high speed operation with a rotating disk rotation speed of 600 rpm or more. If you want to obtain a product with a particle size of 1 to 3 μm, use a medium or large diameter ball with a diameter of 5 to 10 mm and operate the rotary dish at a high speed of 600 rpm or more. When a ball is used and the rotation speed of the rotating plate is set to a low speed of less than 600 rpm, and a product having an average particle size of less than 1 μm is desired, a medium or large diameter ball having a diameter of 5 to 10 mm is used. At a high speed of 600 rpm or more.

[0015]

According to the method of operating the centrifugal fluidized crusher of the present invention, the most suitable combination of the ball diameter of the crushing medium and the number of revolutions of the rotating plate is selected according to the desired average particle size of the product. By operation, the operation with the highest productivity for the required product particle size is performed.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below 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 fluidized crusher, FIG. 2 is a longitudinal sectional view of a main part of the centrifugal fluidized crusher, FIG. 3 is a correlation curve diagram of the amount of crushed powder and the average particle size of a product, and FIG. FIG.

In FIG. 1, the rotating plate 6 is connected to an output shaft of a speed reducer 25 via a rotating shaft 2 and a coupling 2a vertically provided below the center of the rotating plate 6, and a variable speed motor 26 is provided.
Is driven to rotate. On the other hand, small clearance 1
An outer peripheral ring 7 is disposed around the rotating plate 6 with a column 9 and a base 23 interposed therebetween, and a pulverizing chamber 27 which is a space formed by the rotating plate 6 and the outer peripheral ring 7 is formed by a conventional technique. As described above, the raw material is subjected to the centrifugal flow pulverizing action of the pulverizing medium and is pulverized or ultra-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 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.
2 is disposed so as to protrude and drop into a classifying chamber 47 formed below. Further, a venturi tube 46 is provided above the through hole 44, and a compressed air supply tube 60 for blowing compressed air to the inner surface of the bag filter element 50 is guided from outside the venturi tube above the venturi tube 46. Nozzle 6
Oa is disposed 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 motor 26, the speed reducer 25, and the column base 24 configured as described above are fixed to the upper surface of the common base 100.

The operation of the present invention configured as described above will be described. In the grinding chamber 27, for example, a large number of grinding media made of, for example, spherical balls are charged. First, a pulverized raw material is charged into the apparatus from a charging pipe (not shown). As the rotating plate 6 rotates, the raw material and the grinding medium are combined with a circular motion (arrow S) circulating between the inner wall surface 7a of the outer peripheral ring 7 and the plate surface 6a, and a revolving motion around the axis of the rotating plate 6. A spiral motion (centrifugal flow) is performed as if twisting a rope by, while grinding or stripping of the pulverized raw material is performed.
That is, when the rotating plate 6 is rotated, the crushing medium is moved in the outer peripheral direction by centrifugal force, and crawls up the inner wall surface 7a of the outer peripheral ring 7 by this velocity energy. It separates from the inner wall surface 7a and falls on the plate surface 6a of the rotating plate 6. The crushed 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 rotating plate 6 is rotated, the grinding medium revolves in the circumferential direction at a speed lower than the rotating speed of the rotating plate 6. Therefore, the grinding medium is applied to the dish surface 6a as described above.
In addition to the vertical circular movement S circulating through the inner wall surface 7a and the inner wall surface 7a, it also performs a revolving motion that rotates around the axis of the rotating plate 6, and performs a spiral traveling motion such as a twine that combines these two motions. Centrifugal flow).

As described above, the crushing medium moves up the inner wall surface 7a while maintaining the movement of the rotating plate 6 in the circumferential direction. When the inner wall surface 7a is fixed, the crushing medium is moved. Of the inner wall surface 7a as it is with the circumferential speed (revolution speed) and the speed at which the pulverizing medium rises.
And the speed 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 grinding medium that has landed on the upper surface smoothly rolls down along the plate surface 6a, the potential energy obtained when running up the inner wall surface 7a by the movement when rolling down the plate surface 6a is used in the radial direction. Since the kinetic energy can be converted into the kinetic energy, the energy once applied to the pulverizing medium can be effectively used for the peeling action without unnecessarily consuming the energy. Further, when descending along the plate surface 6a, the grinding medium slides on the plate surface 6a, so that grinding or peeling is performed even during this descending movement.

FIG. 3 shows a rotating plate having a diameter of 400 mm.
Of when the continuous operation was ball diameter and the rotary disc rotation speed parameters when carried out in a centrifugal fluidized pulverizer, showing the correlation between the product mean particle size Dp ₅₀ and the grinding amount Q, crushed material starting material 82μm Of fused silica. The grinding media used were single zirconia balls of 10 mm, 5 mm, and 3 mm, respectively. According to FIG. 3, it is 5mm balls and 10mm large grinding amount Q is a ball when 3mm ball when the rotational speed is in excess of 5μm products average particle size Dp ₅₀ in the low-speed operation of 500 rpm, the product average grain size finely reversed The more the ball becomes 3 mm, the smaller the grinding amount Q becomes. In high-speed operation with a rotation speed of 700 rpm, a total of 5
The grinding amount Q is higher than that of the low-speed operation at 00 rpm.
When the ball was a 10 mm ball, the result that the grinding amount Q was high was obtained. And almost the same result was obtained even if the crushing material changed.

From the above results, the product average particle size Dp ₅₀ is 5
In order to carry out continuous operation with a high pulverization amount Q in accordance with a value exceeding 3 μm, 3 to 5 μm, 1 to 3 μm, and less than 1 μm, 600 rpm
Operation at a low speed of less than 600 rpm
The operation at over rpm is defined as high-speed operation.
When the m and 3 mm balls are referred to as a large-diameter ball, a medium-diameter ball, and a small-diameter ball, respectively, as summarized in FIG.
_{If 50} = 5 μm or more, 3 mm ball or less 1 to 3 mm ball
Driving at a low speed with a 2 mm ball, Dp ₅₀ = 3 to 5 μm
High speed operation with a 10 mm ball, low speed operation with a 5 mm ball when Dp ₅₀ = 1 to 3 μm, or 5 to 10 m
high-speed operation at m ball, high grinding rate Q is obtained by a high-speed operation in 5~10mm balls to obtain Dp ₅₀ = 1 mm less than the micronized product.

Since the characteristic curve shown in FIG. 3 is slid up and down somewhat depending on the crushing material, a crushing material having a high crushing frequency and a crushing material having a small allowable width of a desired particle size are subjected to a test operation in advance. It is desirable to collect and organize data.

According to the continuous operation method of the present invention, the characteristics in the correlation between the amount of pulverization and the average particle size of the product in the centrifugal fluidized pulverizer are sufficiently grasped and the operation suitable for the characteristics is performed.
Efficient pulverization is performed, and the productivity of a product having a desired particle size is high.

[0026]

As described above, according to the operation method of the present invention, a grinding medium having an appropriate ball diameter is selected, and efficient operation is performed at an appropriate rotation speed. It can be obtained quickly and productivity can be improved.

[Brief description of the drawings]

FIG. 1 is an overall vertical cross-sectional view of a centrifugal fluidized crusher according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a main part of a centrifugal fluidized-pulverizing apparatus according to an embodiment of the present invention.

FIG. 3 is a correlation curve diagram of a pulverized amount and an average particle size of a product in a continuous operation according to an example of the present invention.

FIG. 4 is an explanatory diagram of an operation guideline of a continuous operation method according to an embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view of a main part of a conventional centrifugal flow pulverizer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Centrifugal fluid crushing apparatus 2 Rotating shaft 6 Rotating dish 6a Dish surface 7 Outer ring 7a Inner wall surface 18 Air introduction pipe 19 Clearance 27 Grinding chamber 40 Cylindrical pipe 40a Top plate 40b Cylindrical pipe 40c Cover 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 Blowing nozzle 100 Common base S Circular motion Dp ₅₀ Average particle size Q Pulverization amount

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B02C 17/00-17/20

Claims (1)

(57) [Claims] 1. A rotating shaft center is oriented in a vertical direction, and has a conical dish surface whose diameter increases downward, and
A rotatable dish-shaped rotating dish whose longitudinal section is concavely curved from a central portion to an outer peripheral portion , and at least an upper portion has an inner wall surface whose diameter is reduced upward. The longitudinal cross section of the shape is curved concavely, comprising a stationary outer peripheral ring is provided coaxially around the rotating dish, the dish surface of the rotating dish and the inner wall surface of the outer peripheral ring, Except for the minute gap between the rotating plate and the outer peripheral ring, in the continuous operation of the centrifugal fluidized pulverizer formed on a continuous smooth surface, the pulverizing medium stored together with the pulverized raw material in the centrifugal fluidized pulverizer, If you want to obtain a product with an average particle size of 5 μm or more, the diameter is 3
mm and a small diameter ball of 6 mm
If the operation is to be performed at a low speed of less than 00 rpm and a product with an average particle size of
A medium or large diameter ball with a diameter of 10 to 10 mm and a high speed operation with a rotating speed of 600 rpm or more are required.
A medium or large diameter ball of 10 mm and a high speed operation of a rotating plate with a rotation speed of 600 rpm or more, or a low speed operation of a medium diameter ball with a diameter of 5 mm and a rotation speed of less than 600 rpm, If you want to obtain a product with an average particle size of less than 1 μm,
A method for operating a centrifugal fluidized-pulverizer, in which a medium or large-diameter ball having a diameter of 10 to 10 mm is used and the rotation speed of a rotating plate is set to a high-speed operation of 600 rpm or more.