JPH08299909A - Box type fluidized bed classifier - Google Patents

Abstract

PURPOSE: To provide a box type fluidized bed classifier which excels in classifying performance and is reduced in equipment size and also in wear and is maintained without requiring many times and labors. CONSTITUTION: This classifier is provided with a classifier body 11 having a required height and extending in the horizontal direction, a screen 12 vertically installed at an intermediate position of the classifier body 11 in the horizontal, direction and having a divided fluidized bed chamber 13 and a classifying and takeoff chamber 14 in the classifier body 11 and fine particle through holes 15 and coarse particle through holes 16 in the upper and the lower parts through respectively, an air introducing chamber 19 formed in the bottom part of the fluidized bed chamber 13 through a diffusing plate 17, a granular body feeding port 20 installed in the fluidized bed chamber 13, and a discharge port 23 formed in the upper part of the fluidized bed chamber 13. The classifying takeoff chamber 14 is provided with a fine particle takeoff port 28 so as to communicate with the fine particle through holes 15 of the screen 12, and a coarse particle takeoff port 29 so as to communicate with the coarse particle through holes 16 of the screen 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a box type fluidized bed type classifier.

[0002]

2. Description of the Related Art Generally, in an apparatus for producing cement or the like, a cement raw material such as cement clinker is preliminarily pulverized by a premill such as a vertical mill or a crusher,
The raw material of the preliminarily crushed powder is sent to a classifier to be classified into fine particles and coarse particles, and then the coarse particles are returned to the preliminary crusher for crushing and the fine particles are sent to a main crusher such as a ball mill. It is further pulverized in order to obtain the fine powder that becomes the product.

Conventionally, as a classifier used in such an apparatus, there is a sieve type classifier 1 as shown in FIG. 9, and the sieve type classifier 1 has a powder / granule introduction port 2 in the upper part. In the classifier body 3, a sieve 4 slanted in a downward gradient is provided in multiple stages (5 in FIG. 9) so that the mesh of the sieve 4 gradually becomes finer toward the lower stage.
A fine particle distribution chamber 5 which is disposed in the lowermost stage 4 and is inclined in the same direction as the sieve 4 and which is communicated with the fine particle distribution chamber 5 at the lower end of the fine particle distribution chamber 5. An outlet 6 is provided, a coarse-grained flow chamber 7 is formed on the side of the lower end of each of the sieves 4, and a coarse-grained outlet 8 that communicates with the coarse-grain flow chamber 7 is provided. A vibration generator 9 for vibrating the sieve 4 is provided.

In the sieve type classifier 1 described above, the granular material A preliminarily pulverized by the preliminary pulverizer (not shown) is introduced from the granular material inlet 2 and each sieve 4 is moved by the vibration generator 9. When vibrated, first, only the granular material A that cannot pass through the coarsest mesh 4 of the uppermost stage remains on the sieve 4, and those having a particle size smaller than that fall onto the lower sieve 4 and this action Is sequentially repeated in each sieve 4, and only the fine particles B are dropped from the lowermost sieve 4. The fine particles B dropped from the lowermost sieve 4 pass through the fine particle flow chamber 5 and the fine particle outlet 6 Is sent to a main crusher (not shown) and crushed. Further, the coarse particles C, which have moved toward the lower end side by vibration on the sieve 4 without dropping from the mesh of each sieve 4, drop into the coarse particle flow chamber 7 and are sent from the coarse particle outlet 8 to the preliminary crusher. It is pre-crushed again.

[0005]

However, in the case of the conventional sieve type classifier 1, when the powder particles A to be classified are highly abrasive such as cement clinker, each is vibrated by the vibration generator 9. Due to continuous collision between the sieve 4 and the granular material A, the respective sieves 4 are severely worn. Therefore, it is necessary to replace each sieve 4 frequently (about once every two months), and this replacement work is difficult. Therefore, the maintenance is troublesome, and the classification efficiency is poor because the classification work must be stopped at the time of maintenance. In addition, the classification by the sieve 4 is apt to cause clogging, resulting in poor classification efficiency and a large amount of powder. In order to process the granules A, there is a problem that the device becomes very large, and further, there is a problem that the vibration of the classifier body 3 by the vibration generating device 9 adversely affects other peripheral devices.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a box-type fluidized bed type classifier which is excellent in classifying performance, can be downsized, and has little wear and maintenance. It is a thing.

[0007]

A box-type fluidized bed classifier according to the present invention has a classifier body which has a required height and extends in the lateral direction, and is erected at an intermediate position in the lateral direction of the classifier body. Then, the inside of the classifier body is divided into a fluidized bed chamber and a classifying / unloading chamber, and a screen having fine particle passage holes in the upper portion and coarse particle passage holes in the lower portion, and a diffusion plate at the bottom of the fluidized bed chamber. Through the air introduction chamber, the powder and granular material supply port provided in the fluidized bed chamber, the exhaust port formed in the upper part of the fluidized bed chamber, and the classification and extraction so as to communicate with the fine particle passage hole of the screen. It is characterized in that it is provided with a fine particle outlet formed in the chamber and a coarse particle outlet formed in the classification and extraction chamber so as to communicate with the coarse particle passage hole of the screen.

The air diffusing plate is an inclined air diffusing plate that is formed in a downward slope from the installation position of the powder and granules toward the installation position of the screen.

Between the boundary between the fine particle outlet and the coarse particle outlet and the screen, there is provided a classification adjusting plate having a required vertical width and supported by a vertical drive device so that the vertical position can be adjusted. It is characterized by

The powdery or granular material supply port is characterized by being provided with an airtight supply device capable of maintaining the airtightness and quantitatively supplying the powdery or granular material.

The fine particle outlet and the coarse particle outlet are each equipped with an airtight discharge device capable of discharging a fixed amount while maintaining airtightness.

[0012]

According to the first means of the present invention, the powder or granular material supplied from the powder or granular material supply port to the fluidized bed chamber is ejected from the air introducing chamber through the diffuser plate substantially uniformly from the entire bottom surface. When fluidized by air, a fluidized bed having fine particles in the upper layer and coarse particles in the lower layer is formed.

The fine particles in the upper part of the fluidized bed pass through the fine particle passage holes formed in the upper part of the screen, flow into the fine particle outlet and are taken out to the outside, and the coarse particles in the lower part of the fluidized bed are diffused. Move to the screen side while flowing on the plate,
The coarse particles pass through the coarse particle passage hole formed in the lower part of the screen, flow into the coarse particle outlet, and are taken out.

At this time, a stable fluidized bed is formed in the fluidized bed chamber, and only the fine particles in the upper part of the fluidized bed are overflowed to the fine particle outlet to be separated, so that only the fine particles that have passed through the fine particle passage holes are formed. Can be accurately classified, and a large amount of powder and granules can be continuously classified, so that the apparatus can be downsized.

Further, in the second means, the diffuser plate is formed in a downward slope from the installation position of the granular material supply port toward the installation position of the screen, so that the diffusion plate is provided from the granular material supply port to the fluidized bed chamber. The supplied particles move well toward the screen side, and the formation of the fluidized bed becomes more stable.

Further, in the third means, since the particle size distribution is formed in the fluidized bed such that the particle size gradually increases from the upper side to the lower side, the boundary between the fine particle outlet and the coarse particle outlet is formed. By adjusting the vertical position of the classification adjusting plate provided between the section and the screen, it is possible to easily adjust the particle size of the fine particles and the coarse particles to be separated.

In the fourth means, an airtight supply device is provided at the powder and granular material supply port, and in the means of claim 5, the airtight discharge device is provided at the fine particle outlet and the coarse particle outlet, so that a fluidized bed is provided. It is possible to prevent the change of the external pressure from acting on the chamber, so that the fluidized bed is stabilized, and the classification with higher accuracy becomes possible.

[0018]

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

FIGS. 1 to 3 show an example of a box type fluidized bed classifier according to the first and fourth aspects of the present invention. The box type fluidized bed classifier 10 has a required height. Lateral direction (Fig. 1, Fig. 2
Classifier body 1 formed in a slender shape (in the left-right direction)
1, a screen 12 is disposed vertically at a lateral intermediate position of the classifier body 11, and the screen 12
Thus, the inside of the classifier body 11 is divided into a fluidized bed chamber 13 and a classifying / unloading chamber 14.

As shown in FIG. 3, the screen 12 has a fine grain passage hole 15 formed of a narrow slit formed in the upper portion thereof, and a coarse grain passage hole 16 formed of a wide slit formed in the lower portion thereof.

At the bottom of the fluidized bed chamber 13, a diffuser plate 17 made of a perforated plate, a mesh material, felt or the like is arranged. Below the diffuser plate 17, flowing air 18 is provided. An air introducing chamber 19 for introducing is formed.

At a position away from the screen of the fluidized bed chamber 13, there is provided a powdery or granular material supply port 20 which penetrates the upper part of the classifier body 11 and has its lower end extending to the upper side of the diffuser plate 17, A powder hopper 22 is connected to the upper part of the powder supply port 20 via an airtight supply device 21 including a rotary valve or the like that can supply the powder A in a fixed amount while maintaining airtightness.

Further, an exhaust port 23 is formed in the upper part of the fluidized bed chamber 13. The exhaust port 23 is connected to a fine powder collecting device 25 which is sucked by a suction fan 24, sucks the air in the fluidized bed chamber 13, and collects the fine powder contained in the exhaust. It has become so.

A boundary plate 27 having an upper end located at a boundary portion 26 between the fine particle passage hole 15 and the coarse particle passage hole 16 of the screen 12 and a downward slope at the other end is provided in the classification and extraction chamber 14. , The screen 12 above the boundary plate 27.
Fine particle outlet 28 adapted to communicate with the fine particle passage hole 15 of
And a coarse particle outlet 29 is formed below the boundary plate 27 so as to communicate with the coarse particle passage hole 16 of the screen 12.

The fine grain outlet 28 and the coarse grain outlet 2 are also provided.
At the lower end of 9, there are provided airtight discharge devices 30 and 31 composed of rotary valves or the like capable of quantitatively discharging fine particles B and coarse particles C while maintaining airtightness.

FIG. 4 shows another example of the screen 12, in which a fine particle passage hole 15a consisting of a small diameter hole is formed on the upper side, and a coarse particle passage hole 16a consisting of a large diameter hole is located on the lower side. FIG. 5 shows still another example, in which fine particle passage holes 15b made of a narrow mesh are formed on the upper side, and coarse particle passage made of a wide mesh is formed. The case where the hole 16b is formed on the lower side is shown.

The operation of the above embodiment will be described.

The granular material A preliminarily pulverized by a preliminary pulverizer (not shown) and temporarily stored in the granular material hopper 22 is
The powder is supplied to the fluidized bed chamber 13 through the airtight supply device 21 from the powder / granule supply port 20.

The granules A supplied to the fluidized bed chamber 13 are fluidized by the air 18 ejected from the air introduction chamber 19 through the diffuser plate 17 almost uniformly upward from the entire bottom surface, The upper layer is a fine particle B, and the lower layer is a coarse particle C.

The fine particles B in the upper part of the fluidized bed chamber 13 are the screen 1
The fine particles B flow into the fine particle outlet 28 through the fine particle passage hole 15 on the upper side of 2, and only the fine particles B are taken out through the airtight discharge device 30.

The coarse particles C in the fluidized bed chamber 13 move to the screen 12 side while flowing on the diffuser plate 17, pass through the coarse particle passage holes 16 on the lower side of the screen 12, and take out the coarse particles. It flows into 29 and is taken out through the airtight discharge device 31.

As described above, a stable fluidized bed is formed in the fluidized bed chamber 13, and only the fine particles B in the upper part of the fluidized bed are overflowed to the fine particle outlet 28 through the fine particle passage hole 15 and separated. , Fine particle outlet 2
It is possible to accurately classify only the fine particles B in No. 8 and to classify a large amount of the powdery particles A continuously, so that the apparatus can be downsized.

Further, since the powdery or granular material supply port 20 is provided with the airtight supply device 21 so that the powdery or granular material A is quantitatively supplied to the fluidized bed chamber 13 while maintaining the airtightness, A stable fluidized bed can be formed in the fluidized bed chamber 13 by preventing pressure fluctuations from reaching the fluidized bed chamber 13.

Further, a fine grain outlet 28 and a coarse grain outlet 29.
By providing the airtight discharge devices 30 and 31 to discharge the fine particles B and the coarse particles C, it is possible to prevent fluctuation of pressure on the discharge side from reaching the fluidized bed chamber 13, and
3 can form a stable fluidized bed.

FIG. 6 shows an embodiment of the invention of claim 2, in which the diffuser plate 17 shown in FIG. 1 descends from the installation position of the powder and granular material supply port 20 toward the installation position of the screen 12. The case where the inclined diffuser plate 32 is formed to have a gradient is shown.

According to the configuration shown in FIG. 6, the inclined diffuser plate 3
2, the powder A is supplied from the powder supply port 20 to the fluidized bed chamber 13 and moves well toward the screen 12 side, so that the fluidized bed is formed more stably. Like

FIG. 7 and FIG. 8 show an embodiment of the invention of claim 3, which is required in the vertical direction between the boundary plate 27 of the fine grain outlet 28 and the coarse grain outlet 29 and the screen 12. A classifying adjustment plate 33 having a width is arranged, and a vertical drive device 34 such as a cylinder for adjusting the vertical position of the classification adjusting plate 33 is arranged on the side of the classifier body 11. In the figure, 35 is a long hole formed in the classifier body 11 for vertical movement, and 36 is a seal plate for closing the long hole.

In the fluidized bed, the particle size distribution is formed so that the particle size gradually increases from the upper side to the lower side. Therefore, the vertical drive unit 34 of FIG. Boundary plate 27 of coarse grain outlet 29 and screen 1
By adjusting the vertical position of the classification adjusting plate 33 provided between the two, it is possible to easily adjust the particle size of the fine particles B and the coarse particles C to be separated.

[0039]

According to the present invention, a stable fluidized bed is formed in the fluidized bed chamber, and only the fine particles in the upper part of the fluidized bed are overflowed to the fine particle outlet through the fine particle passage holes to be separated. Only the fine particles can be accurately classified at the fine particle outlet, and a large amount of powder particles can be continuously classified, so that the apparatus can be downsized.

Furthermore, since a stable fluidized bed is formed and classification is performed, a large amount of powder and granules can be continuously and efficiently treated as compared with the conventional sieve type classifier, resulting in abrasion. Is less likely to occur and maintenance is easy.

By forming the diffuser plate in a downward slope from the installation position of the powder and granular material supply port toward the installation position of the screen, the powder and granular material supplied from the powder and granular material supply port to the fluidized bed chamber is screened. Since it will move well toward the side,
The formation of the fluidized bed can be further stabilized.

Since the fluidized bed has a particle size distribution in which the particle size gradually increases from the upper side to the lower side, it is provided between the screen and the boundary between the fine particle outlet and the coarse particle outlet. By adjusting the vertical position of the classification adjusting plate, the particle size of the fine particles and the coarse particles to be separated can be easily adjusted.

An airtight supply device may be provided at the powder or granular material supply port,
Further, since the airtight discharge device is provided at the fine particle outlet and the coarse particle outlet, it is possible to prevent the change of the external pressure from acting on the fluidized bed chamber, so that the fluidized bed is stable and further accurate. High classification is possible.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of the inventions of claims 1 and 4. FIG.

FIG. 2 is a view taken along the line II-II of FIG.

FIG. 3 is a view taken in the direction of arrows III-III in FIG. 1;

FIG. 4 is a front view showing another example of the screen.

FIG. 5 is a front view showing still another example of the screen.

FIG. 6 is a cut side view showing an embodiment of the invention of claim 2;

FIG. 7 is a cut side view showing an embodiment of the invention of claim 3;

FIG. 8 is a view on arrow VIII-VIII in FIG. 7.

FIG. 9 is a vertical cross-sectional view showing an example of a sieve type classifier used conventionally.

[Explanation of symbols]

 10 box type fluidized bed classifier 11 classifier main body 12 screen 13 fluidized bed chamber 14 classification take-out chamber 15 fine particle passage hole 15a fine particle passage hole 15b fine particle passage hole 16 coarse particle passage hole 16a coarse particle passage hole 16b coarse particle passage hole 17 Air diffuser plate 19 Air introduction chamber 20 Powder and granule supply port 21 Airtight supply device 26 Boundary portion 28 Fine particle outlet 29 Coarse particle outlet 30 Airtight exhaust device 31 Airtight exhaust device 32 Inclined air diffuser 33 Classification control plate A Powder and granular material

Claims (5)

[Claims] 1. A classifier body having a required height and extending in the lateral direction, and a standing bed at a lateral intermediate position of the classifier body, and a fluidized bed chamber and a classifying chamber inside the classifier body. A screen having fine particle passage holes in the upper portion and coarse particle passage holes in the lower portion, an air introduction chamber formed through a diffuser plate at the bottom of the fluidized bed chamber, and provided in the fluidized bed chamber. And granular material supply port,
An exhaust port formed in the upper part of the fluidized bed chamber, a fine particle outlet formed in the classifying and extracting chamber so as to communicate with the fine particle passing hole of the screen, and the classifying and taking chamber so as to communicate with the coarse particle passing hole of the screen. A box-type fluidized bed type classifier, characterized in that it has a coarse particle take-out port formed in. 2. The box type flow according to claim 1, wherein the air diffuser plate is an inclined air diffuser plate which is formed in a downward slope from the powder particle supply port installation position toward the screen installation position. Layer type classifier. 3. A classification adjusting plate, which is arranged with a required vertical width between the boundary between the fine particle outlet and the coarse particle outlet and the screen, and is supported by a vertical drive device so that the vertical position can be adjusted. The box type fluidized bed type classifier according to claim 1 or 2, further comprising: 4. The box-type fluidized bed according to claim 1, 2 or 3, wherein the powder / granule supply port is provided with an air-tight supply device capable of quantitatively supplying the powder / granulate while maintaining airtightness. Type classifier. 5. The box type flow according to claim 1, 2 or 3 or 4, characterized in that the fine particle outlet and the coarse particle outlet are provided with an airtight discharge device capable of discharging air in a fixed amount while maintaining airtightness. Layer type classifier.