JP2697015B2 - Granule classifier - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a classifier for classifying coarse powder and fine powder from granules such as cement or cement raw materials. More particularly, the present invention relates to a classifier that classifies powder and granules with high and low accuracy with a certain particle size.

[Conventional technology]

The prior art will be described using a starter band type classifier conventionally used for classifying cement raw materials or cement clinker powder and the like.

As shown in FIG. 5, the starter band classifier has a housing 1 in which a cone portion is connected to a lower end portion of a cylindrical body having a closed upper portion, a housing 1 provided on the same axis as the housing 1, and An inner cylinder 2 having a rounding door 3 attached to an intermediate portion of a cone portion connected to a lower end portion of a cylindrical cylinder having an open upper portion;
A disk-shaped dispersing plate 6 mounted on the lower end of a rotating shaft 4 that is rotatably penetrated through the center of the ceiling portion of the housing 1.
And a bearing 7 so that it can rotate in synchronization with the dispersion plate 6.
And a fan blade 11 provided between the ceiling of the housing and the upper end of the inner cylinder, and mounted on the rotary shaft.
And an air flow control valve 12 composed of a plurality of baffles installed at the upper end of the inner cylinder so as to be able to move back and forth through the housing wall 1.

The air flow in the classifier generates a swirling upward flow 16 in the inner cylinder 2 and a swirling downward flow 17 in the housing 1 due to the rotation of the main blade 11 accompanying the rotation of the rotating shaft 4.
Is circulated through.

The powder pulverized by a pulverizer (not shown) is supplied to a charging chute 13 hanging on the same axis as the rotating shaft.
As shown in FIG. 5, the input raw material powder falls from the chute 13 onto the dispersion plate 6 being rotated by the driving device 18 and moves on the dispersion plate 6 by centrifugal force to move around the periphery of the dispersion plate 6. It is thrown more horizontally toward the inner cylinder wall. The thrown powder is dispersed in the swirling upward flow 16 which blows up through the armor door 3, and the coarse powder having a large particle diameter falls downward by gravity and is discharged from the coarse particle discharge port 14. You. The powder of the intermediate particle diameter moves slowly upward on the swirling upward flow 16 and collides with the sorting blade 8, is thrown out to the inner cylinder wall, falls downward by gravity, and is provided at the lower end of the inner cylinder 2. The discharged chute 14 is discharged outside the machine together with the coarse particles.

A swirling downward flow 17 is generated in the space between the housing 1 and the inner cylinder 2 by the fan blades 11.

Fine powder that rises with the airflow through the sorting blades 8 due to the swirling downward flow is separated from the airflow by centrifugal force. The air flow is circulated through the inner door into the inner cylinder, and the fine powder is discharged from the discharge chute provided at the lower end of the housing 1.
Released as a product outside the aircraft from 15.

[Problems to be solved by the invention]

In the conventional apparatus, as shown in FIG.
Since the raw material powder is dispersed in the narrow space between the vertical wall and the fine powder having a particle size equal to or less than the particle size to be classified because the powder concentration in this space is increased and the dispersion of the powder is inhibited, or The fine powder is not separated but separated as a coarse powder without riding on the swirling upward flow 16, and a so-called fine powder stray phenomenon occurs. Countermeasures When the in-cylinder wind speed is increased unnecessarily, a part of coarse powder having a particle size larger than the particle size to be classified passes through the sorting blade 8 and is collected together with the fine powder. As a result, the classification efficiency is deteriorated and the amount of repetition to the pulverization system is increased, which is a main factor for increasing the power unit of the pulverization system.

The present invention relates to the improvement of such a classifier, and has developed a classifier with good operability that solves the above-mentioned problems and has improved classification efficiency. In other words, as a result of the study for the above purpose, an ascending airflow is formed in a housing in which a cone portion is connected to a lower end of an upright cylindrical cylinder having a closed top end, and a wind type in which powder is classified by this airflow. In a granular material classifier, the powder introduced into the classifier is dispersed in a space, and the dispersed powder is classified into a fine powder having a particle size smaller than a predetermined particle size and a coarse powder having a particle size larger than the particle size. Machine was developed.

The present invention seeks to provide such a classifier.

[Means for solving the problem]

According to the present invention, 1) a vertical shaft is hung in a classifier, and an annular selection blade mounting plate is mounted on the end of the rotating shaft.

2) A disk-shaped dispersion plate for dispersing the powder put into the classifier is mounted on the upper portion of the selection blade mounting plate.

3) An annular ceiling plate supported by the dispersion plate and a bearing is provided on the upper portion of the dispersion plate, and a classifying chamber is defined between the ceiling plate and the sorting blade mounting plate.

4) Attach a collision plate to the ceiling plate at a position where the powder dispersed by the dispersion plate collides.

5) A plurality of sorting blades, each blade of which can be set at an arbitrary angle around a vertical axis, at least one stage, between the outlet of the classifying chamber, that is, the periphery of the ceiling plate and the outer periphery of the sorting blade mounting board. Provide.

6) A cylindrical raw material powder input chute having a discharge end on the dispersion board and penetrating through the ceiling plate is provided on the same axis as the rotating shaft.

That is, according to the present invention, a main blade for circulating gas is provided at an upper portion of an outer cylinder of an upright double cylinder having an inner cylinder and an outer cylinder having a coaxial core, and an air flow descending in the outer cylinder is provided at a lower portion of the inner cylinder. In a wind-type powder and particle classifier that forms an updraft in the inner cylinder by providing an armoring door that introduces the air into the inner cylinder, and disperses and classifies the powder in the updraft, a large number of sorting blades A cylindrical cage-like classifying chamber arranged on the circumference is rotatably installed inside the inner cylinder with a gap from the inner surface of the inner cylinder,
The rising air flow enters the classifying chamber from below, forms a path that flows out of the classifying chamber through the sorting blades, and a disc-shaped dispersion plate that suspends the powdery particles in the air flow is suspended above the classifying chamber. This is a classifier for a powdery or granular material characterized by the following. In this device, it is preferable that each of the plurality of sorting blades is rotatable at an arbitrary angle around an axis parallel to the cylindrical axis, and that the selecting blade is divided into a plurality of stages in the cylindrical axis direction. It is suitable.

[Action]

 The operation of the present invention will be described based on an embodiment shown in the drawings.

FIG. 1 is a longitudinal sectional view of a classifier of the present invention, and FIG.
It is an AA arrow line view of the figure. The powder pulverized by a pulverizer (not shown) is supplied to a dispersion board 106 via a powder material supply chute 113. The powder on the dispersing plate 106 moves toward the periphery of the dispersing plate 106 due to the centrifugal force caused by the rotation of the dispersing plate 106, and is thrown from the outer periphery of the dispersing plate 106 into the dispersion space.
The thrown powder reaches a collision plate provided on a ceiling plate connected via a dispersion plate and a bearing, and is uniformly re-distributed to the collision plate surface by the centrifugal force due to the rotation of the collision plate and the gravity of the powder. It moves downward while being dispersed. The powder that has reached the lower end of the impingement plate falls along a trajectory diagonally downward due to the centrifugal force associated with the rotation of the impingement plate and the gravity of the powder particles.

On the other hand, the airflow for classification is sucked by a fan installed inside or outside the classifier and introduced into the classification chamber through the opening of the swirl vane mounting plate at the bottom of the classification chamber, and passes through the dispersion zone of the powder. Then, particles having a particle size equal to or smaller than a predetermined particle size are discharged to the outside of the classifying chamber through a separation blade provided at the outlet of the classifying chamber. At this time, among the particles entrained in the air stream for classification, the particles having a relatively large particle diameter collide with the swirling vanes because of their slow moving speed, are returned to the classification chamber, and fall downward by their own weight, and fall for the classification. Is discharged out of the classification room together with the powder not entrained in the airflow of the air.

The airflow discharged outside the classification room is separated into the airflow and the fine powder in a separation section provided outside the classifier or inside the classification device, the airflow is returned to the classification room again, and the fine powder is discharged as a product outside the classification room. Is done.

The size of the classifying chamber, the number of sorting blades to be mounted, the blade width, and the number of stages are appropriately determined according to the type of powder to be classified, the size of the classifier, the load condition, and the like.

Each of the sorting blades can rotate around a vertical axis. Regarding the mounting angle of the blade, if the end of the blade is directed upstream with respect to the rotation direction from the radius line of the selection blade mounting board, the separation particle size becomes small (product fineness decreases), and the downstream side , The separation particle size increases due to the fan effect.

Further, the shape of the sorting blade is preferably a plate shape, but the shape and the mounting method are not limited as long as the above function is achieved.

The size of the dispersing plate 106 in the dispersing chamber may be such that centrifugal force is applied to the dropped powder, and the distance between the dispersing plate and the impingement plate and the size of the impinging plate may cause the powder to fall directly downward. It does not need to be particularly limited.

〔Example〕

FIG. 1 is a longitudinal sectional view of a classifier obtained by modifying a conventional classifier in accordance with the gist of the present invention.

A cylinder 101 having a diameter of 4.88 m and a cone connected to the lower part of a cylindrical shape whose upper part is sealed, and a cone which is installed on the same axis as the outer cylinder 101 and is connected to the lower part of the cylindrical part whose upper part is open Inner cylinder with a diameter of 4.20 m with an armoring door 103 at the middle of the section
102, a disk-shaped dispersion plate 106 mounted on a rotating shaft 104 suspended through the center of the ceiling of the outer cylinder 101, and a dispersion plate 10
6, a support metal fitting 107 for supporting the dispersion plate 106 and the ceiling plate 105 so as to be rotatable in synchronization with 6, a collision plate 112 attached to the ceiling plate 105 at a distance from the periphery of the dispersion plate 106, and ,
A disc-shaped sorting blade mounting board 109 mounted on the shaft end of the rotating shaft 104, a sorting blade 108 installed between the ceiling plate 105 and the sorting blade mounting board 109, and rising from the ceiling plate 105. A main blade 111 attached to the tip of a main blade mounting bracket 110 made of a tubular or steel frame, an opening in the ceiling of the outer cylinder 101, and a space defined around the rotation shaft. It is constituted by a hanging chute 113.

Raw material powder pulverized in a raw material mill not shown
35T / h is injected into the classifier by the chute 113. The input raw material powder falls onto a dispersion board 106 in a classification chamber mounted on a rotating shaft 104. The raw material powder on the dispersing plate moves on the dispersing plate 106 due to the centrifugal force caused by the rotation of the rotating shaft, and is thrown from the peripheral edge toward the collision plate 112. The raw material powder that has reached the collision plate 112 is uniformly dispersed on the surface of the collision plate with the rotation of the collision plate, and is dispersed in a thin film obliquely downward from the lower end of the collision plate. The fine particles having a particle size equal to or less than a predetermined particle size are entrained in a swirling airflow for classification introduced into the dispersion chamber via an armor door, and when passing through the sorting blades installed at the outlet of the classification chamber, the airflow is reduced. Of the particles entrained by the main particles, the relatively large particles have a slower moving speed, so they collide with the rotating wings rotating with the rotation of the main shaft, return to the classification chamber, and fall downward by their own weight. Then, the powder is discharged out of the classification room together with the powder not entrained in the classification air flow. The fine powder that has passed through the classification chamber together with the airflow for classification is guided to the space between the outer periphery 101 and the inner cylinder 102 by the rotation of the main blade 111, and the fine powder is separated by centrifugal force, and the product is discharged from the discharge chute 114. And discharged outside the classifier.

On the other hand, the coarse powder that does not ride on the swirling upward flow falls downward due to its gravity and is discharged out of the classifier through a discharge chute provided at the lower end of the inner cylinder.

 The main specifications of the classifier are as follows.

Classifier outer cylinder diameter: 4.88m Classifier inner cylinder diameter: 4.20m Classification room ceiling plate diameter: 3.30m Dispersion plate diameter: 2.38m Impact plate installation diameter and width: 2.45m Sorting blade width and length: 200mm x 400mm Sorting blade Number of sheets to be mounted: 60 sheets Sorting blade mounting angle: Using a classification device of 15 degrees or more upstream with respect to the screening blade mounting board, the classification result of the cement clinker pulverized powder having the particle size distribution shown in Table 1 is shown in a distribution rate curve. This is as shown by curve A in FIG. Curve B shows the classification result before remodeling as a comparative example.

From the above results, it is clear that the distribution ratio curve becomes sharper after the modification and the classification efficiency is improved.

FIG. 3 shows an example in which the classification mechanism of the present invention is applied to a fan-external classification device called a cyclone separator.

A classifying chamber having sorting blades 108 is attached to the rotating shaft 4, and a dispersion board 106 is provided. The airflow from a fan (not shown) passes through the classification chamber and the fine powder is collected by the cyclone 121.

FIG. 4 shows an example in which the classification mechanism of the present invention is applied to a side charge type classifier. Raw material supply chute 11 in FIG.
3 may be changed to the supply device 122 from the classification side as shown in FIG.

As described above, the present invention is applicable to any type of classifier.

[Effects of the Invention] As a result of using the apparatus of the present invention to improve the dispersion of powder in the classifier, it was confirmed that the following excellent effects were obtained.

Since the contact space between the powder dispersed in the classifier and the airflow for classification is increased, the speed of the airflow passing through the dispersed powder is reduced. Therefore, the amount of coarse particles transported into the classification chamber is reduced, and the phenomenon that coarse particles are lost in the product is reduced,
The classification efficiency is increased, and the quality of the product is improved. Furthermore, the amount of suction air from the classification airflow fan circulating in the classification machine can be reduced.

The fineness of the product can be adjusted simply by changing the number of revolutions of the classifier or the flow rate of the classifying air flow, and it is easy, can be performed by remote control, and labor can be saved.

Further, since the classification efficiency is improved, the classification load can be increased as compared with a conventional classifier.

[Brief description of the drawings]

1 is a longitudinal sectional view of a classifier according to an embodiment of the present invention, FIG. 2 is a view taken along the line AA of FIG. 1, FIG. 3 is a schematic longitudinal sectional view of another embodiment of FIG. FIG. 5 is a longitudinal sectional view of a conventional classifier, and FIG.
The figure is a distribution curve showing the effect of the present invention. 101 ... outer cylinder, 102 ... inner cylinder 103 ... armor door, 104 ... rotating shaft 105 ... ceiling plate, 106 ... dispersion plate 108 ... sorting blades, 111 ... main blades 112 ... collision plate, 113 …… Chute 114,115 …… Discharge chute

Claims (3)

(57) [Claims] An airflow descending in the outer cylinder at a lower portion of the inner cylinder, wherein a main blade for circulating gas is provided at an upper portion of the outer cylinder of an upright double cylinder having an inner cylinder and an outer cylinder having a coaxial center. In a wind-type powder and particle classifier that forms an updraft in the inner cylinder by providing an armoring door that introduces the air into the inner cylinder, and disperses and classifies the powder in the updraft, a large number of sorting blades A cylindrical cage-shaped classifying chamber disposed on the circumference is rotatably installed in the inner cylinder with a gap between the inner surface of the inner cylinder and the ascending airflow enters the classifying chamber from below, passes through the sorting blades, and is outside the classifying chamber. A classifier for classifying powders and granules, wherein a disc-shaped dispersion plate for suspending powders and granules in an air flow is suspended above the classifying chamber. 2. The classification device according to claim 1, wherein each of the plurality of sorting blades is rotatable at an arbitrary angle about an axis parallel to the cylindrical axis. 3. The classification device according to claim 1, wherein the sorting blade is divided into a plurality of stages in the cylindrical axis direction.