JPH02119981A - Classifier for particulate matter - Google Patents

Abstract

PURPOSE:To precisely classify particulate matter into the oversize and undersize respectively having a fixed particle diameter by hanging a rotational vertical cylinder basket-shaped classification chamber with many classifying blades provided on its periphery in a housing while leaving a space between the inner surface of the housing and the blade. CONSTITUTION:The powder crushed by a crusher is charged onto a diffusion disk 106 through a crushed raw material feed chute 113. The powder on the disk 106 is moved to the periphery of the disk 106 by the centrifugal force caused by the rotation of the disk, and driven out into the diffusion space from the periphery. The powder is then sent to a collision plate 112 provided to a ceiling plate 105, diffused uniformly on the collision plate surface by the centrifugal force caused by the rotation of the collision plate 112 and the gravity of the powder, moved downward, and dropped. The classifying air current passes through the powder diffusion zone, entrains the particles having smaller than the specified diameter, passes through the space between the classifying blade 108 provided at the outlet of the classification chamber, and is discharged to the outside of the chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a classifier for classifying coarse powder and fine powder from a pulverized product such as cement or cement raw material.

More specifically, the present invention relates to a classifier that accurately classifies powder and granules into upper and lower portions of a constant diameter.

rPrior Art 1 The conventional technology will be explained by taking as an example a starch band classifier that has been conventionally used for classifying cement raw materials or cement powder.

As shown in Fig. 5, the starch band type classifier consists of a housing I, which has a cone connected to the lower end of a cylindrical body with a sealed upper part, and a housing I that is installed coaxially with the housing I and has an upper part. An inner cylinder 2 has a shutter door 3 attached to the middle part of a cone part connected to the lower end of an open cylindrical body, and an inner cylinder 2 that freely passes through the center of the ceiling of the housing 1 and hangs down. A disk-shaped distribution disk 6 mounted on the lower end of the rotating shaft 4, and a peripheral edge connected by a support metal fitting 7 so as to be rotatable in synchrony with the distribution disk 6? ! A sorting blade mounting board 9 on which several sorting blades 8 are installed, and a fan blade 11 provided between the ceiling of the housing and the upper end of the inner cylinder and mounted on the rotating shaft.
And, an air volume control valve consisting of a plurality of baffle plates installed at the upper end of the inner cylinder so as to be able to move forward and backward through the housing wall l! 2.

The air flow inside the classifier generates a swirling upward flow 16 in the inner cylinder 2 and a swirling downward flow 17 in the housing l by the rotation of the main blade 11 in conjunction with the rotation of the rotating shaft 4, and these are passed through the shutter 3. It is circulated through

Powder pulverized by a pulverizer (not shown) is fed into a feeding chute 13 that is suspended on the same axis as the rotating shaft.

As shown in FIG. 5, the charged raw material powder falls from the chute 13 onto the dispersion plate 6 which is being rotated by the drive device 18, moves on the dispersion plate 6 by centrifugal force, and is then moved onto the dispersion plate 6 by the centrifugal force.
is thrown horizontally from the periphery toward the inner cylinder wall. The thrown out powder is dispersed in the swirling upward flow 16 that blows up through the shutter 3, and coarse powder with a large particle size falls downward under the force of gravity and is discharged from the coarse particle discharge port 14. Ru. Powder with an intermediate particle size moves upward on the swirling upward flow 16 at a slow speed, so it collides with the sorting blade 8, is thrown onto the inner cylinder wall, and falls downward due to gravity. The particles are discharged from the machine together with the coarse particles through the discharge chute 14 provided therein.

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

The fine powder that passes through the sorting blades 8 and rises with the airflow due to this swirling downward flow is separated from the airflow by centrifugal force. The airflow is circulated into the inner cylinder through the shutters, and the fine powder is removed from the discharge chute located at the lower end of the housing l.
5, the product is discharged outside the machine.

[Problem to be Solved by the Invention 1] In the conventional device, as shown in FIG.
The powder concentration in this space increases and the dispersion of the powder is inhibited, and fine powder with a particle size below the particle size to be classified gets mixed into the coarse powder, or the fine powder is not separated and cannot ride the swirling upward flow 16 and becomes coarse powder. The particles are separated, and a so-called fine powder straying phenomenon occurs. As a countermeasure for this, if the in-cylinder air speed is increased more than necessary, a part of the coarse powder larger than the particle size to be classified will pass through the sorting blade 8 and be collected together with the fine powder, a so-called coarse powder straying phenomenon. As a result, the classification efficiency deteriorates, and the repeated power consumption of the crushing system increases, which is a main factor in increasing the power consumption of the crushing system.5 The present invention relates to improvements in such a classifier. By solving the above problems, we have developed a classifier that has improved classification efficiency and is easy to operate.

In other words, as a result of our studies for the above purpose, we have developed a wind-powered system that forms an upward airflow in a housing that has a cone connected to the lower end of an upright cylindrical body with a sealed top end, and uses this airflow to classify powder. In a powder classifier, the powder charged into the classifier is dispersed in the space, and the dispersed powder is classified into fine powder with a predetermined particle size and coarse powder with a particle size larger than the predetermined particle size.This classification has high classification efficiency. This led to the development of a machine.

The present invention aims to provide such a classifier.

[Means for Solving the Problems] The present invention has the following features: 1) A vertical shaft is suspended in the classifier, and a panel for mounting an annular sorting blade is mounted on the end of the rotating shaft.

2) The sorting vane is attached by installing a disc-shaped dispersion disc on the upper part of the disc for dispersing the powder input into the classifier.

3) An annular ceiling plate supported by the dispersion plate and a support fitting is provided above the dispersion plate, and two stages of classification chambers are provided between the ceiling plate and the sorting blade attachment plate.

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

5) Ii'ii The classification room exit, that is, the periphery of the ceiling plate and the mounting of the sorting blades are equipped with a plurality of sorting blades, each of which can be set at any angle around the vertical axis, between the outer periphery of the panel. Provide at least one stage.

6) A cylindrical raw material powder inputting chute having a discharge end on the dispersion plate and passing through the ceiling plate is provided on one axis of the rotary shaft described in iii.

[Effect 1 The operation of the present invention will be explained based on embodiments shown in the drawings.

FIG. 1 is a longitudinal sectional view of the classifier of the present invention, and FIG. 4 is a view taken along the line A-A in FIG. The liquid is fed onto the distribution board 106 via the.

The powder on the dispersing disk 106 moves toward the periphery of the dispersing disk 106 due to the centrifugal force accompanying the rotation of the dispersing disk 10
It is thrown from the outer periphery of 6 into the dispersion space. The thrown powder reaches the collision plate installed on the ceiling plate, which is connected to the dispersion plate via the support metal fittings, and is uniformly re-reproduced on the collision plate surface by the centrifugal force caused by the rotation of this collision plate and the gravity of the powder. It moves downward while being dispersed. The powder that has reached the lower end of the collision plate falls in a diagonally downward trajectory due to the centrifugal force caused by the rotation of the collision plate and the gravity of the powder particles.

On the other hand, the airflow for 1st classification is sucked by a fan installed inside or outside the 1st classifier, and the swirling vane attached at the bottom of the classification chamber is introduced into the classification chamber through the opening of the panel, and passes through the powder dispersion zone. At this time, particles with a predetermined particle size or less are passed through the separation blades installed at the exit of the classification chamber and discharged outside. At this time, among the particles entrained in the airflow for one classification, particles with relatively large diameters move at a slow speed (
As a result, it collides with the swirling vane, returns to the classification chamber, falls downward under its own weight, and is discharged to the outside of the classification chamber along with the powder that was not entrained in the airflow for the first classification.

The airflow discharged outside the classification chamber is separated into fine powder by a separation section installed outside the classifier body or inside the classifier.
The airflow is returned to the classification chamber and the fine powder is discharged outside the classifier as a product.

The size of the classification chamber, the number of sorting blades to be installed, the width of the blades, and the number of stages are appropriately determined depending on the following: 1, the type of powder to be classified, 1, the size and load condition of the classifier, etc.

Each of the sorting blades can rotate around a vertical axis. For installation of 0 blades, the angle is as follows. For installation of 1 sorting blade, if the end of one blade faces upstream with respect to the direction of rotation with the radius line of the board as the starting point. The separated particle size is small.

In addition, as for the shape of the sorting blade, a root-like one is preferable, but as long as it achieves the above-mentioned effect, there are no limitations regarding the shape and mounting method. The distance between the dispersion plate and the collision plate and the size of the collision plate should be such that the powder does not fall directly downward (there are no particular limitations). It's not a thing.

[Embodiment 1] Fig. 1 is a longitudinal cross-sectional view of a classifier which is a conventional classifier modified in accordance with the gist of the present invention.

An outer cylinder lot with a diameter of 4.88 m with a cone connected to a cylindrical lower part with a sealed upper part, and a cylindrical lower part installed on the same axis as this outer cylinder 101 and connected to an open upper part. An inner cylinder 102 with a diameter of 4.20 m with a shutter 103 attached to the middle part of the cone part, and a disc-shaped cylinder mounted on a rotating shaft 104 penetrating the center of the ceiling of the outer cylinder 101 and hanging down. a supporting metal fitting 107 that supports the dispersion plate 106 and the ceiling plate 105 so as to be rotatable in synchronization with the dispersion plate 106 and the dispersion plate 106; Collision 1112 and 1 installed
The disk-shaped sorting blades mounted on the shaft end of the rotating shaft 104 are attached to the plate 109, and the ceiling plate 105 and the sorting blades are attached to the plate 1.
A sorting blade 108 is installed between the main blade 108 and the main blade Ill, which is installed at the tip of the metal fitting 110, and the main blade made of a cylindrical or steel frame that rises from the ceiling plate 105.
The outer cylinder 101 has an opening in the ceiling and a chute 113 that hangs down around the rotating shaft so as to form a space on both sides.

Raw material powder 3 pulverized in a raw material mill (not shown)
5T/h is fed into the classifier through the chute 113. The input raw material powder falls onto a dispersion disk 106 in the classification chamber mounted on a rotating shaft 104. The raw material powder on the dispersion disk moves on the dispersion disk 106 due to the centrifugal force caused by the rotation of the rotation shaft. It is thrown toward the collision plate 112 from the periphery. The raw material powder that has reached the collision 1112 is uniformly dispersed on the collision plate surface as the collision plate rotates, and is dispersed in a thin film diagonally downward from the lower end of the collision plate. Fine particles with a predetermined particle size or less are entrained in the swirling airflow for classification that is introduced into the dispersion chamber via the shutters, and when passing between the sorting blades installed at the exit of the first classification chamber, this airflow Among the particles that are entrained in the machine, relatively large particles move at a slower speed, so they collide with the swirling vanes that are rotating with the rotation of the main shaft, are returned to the classification chamber, and fall downward due to their own weight. However, the fine powder that has passed through the classification chamber together with the airflow for one classification, which is discharged to the outside of the classification room together with the powder that is not entrained in the airflow for classification, is separated between the outer cylinder lot and the inner cylinder 102 by the rotation of the main blade txt. The fine powder is separated by centrifugal force and discharged as a product from the discharge chute 114 to the outside of the classifier.

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

The main specifications of the classification device 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 Collision plate installation diameter and width: 2.45m Sorting blade width and length : 200mm x 400
m Sorting blades installed: Number of blades = 60 Sorting blades installed: Angle 2 Sorting blades installed: Classify crushed cement clinker powder with the particle size distribution shown in Table 1 using a classifier at an angle of 15 degrees or more on the upstream side with the board as a reference. The result is shown in the distribution ratio curve as shown in Fig. 6. 0 songs as shown in A! IB shows the classification results before modification as a comparative example.

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

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

A classification chamber equipped with sorting blades 108 is attached to the rotating shaft 4, and a dispersion plate 106 is provided. - Airflow from a fan (not shown) passes through this classification chamber and collects fine powder in a 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 l in Figure 1
13 is fed from the side of the classifier as shown in Figure 4. 22
You may change it to

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

Table 1 [Effects of the Invention] By using the apparatus of the present invention, the dispersion of powder in the classifier became better, and as a result, the following excellent effects were confirmed.

Since the contact space between the powder dispersed in the classifier and the air stream for classification becomes wider, the speed of the air stream passing through the dispersed powder becomes slower. Therefore, fewer coarse particles are transported into the classification chamber! Since the phenomenon of coarse particles straying into the 15 products is reduced, the classification efficiency is reduced by -ha and the quality of the product is improved, and the suction air volume of the 1-class airflow fan that circulates inside the 1-class classifier can be reduced.

Adjustment of the powderiness of the product is easy, as it is only necessary to change the rotation speed of the classifier or the flow rate of the classification air flow, and it can be done by remote control, resulting in labor savings.

Furthermore, since the classification efficiency is improved, the classification load can be increased compared to conventional classifiers.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a classifier according to an embodiment of the present invention, FIG. 2 is a view taken along the line A-A in FIG. 1, and FIGS. 3 and 4 are schematic longitudinal cross-sectional views of other embodiments. Figure 5 is a vertical cross-sectional view of a conventional classifier;
The figure is a distribution curve showing the effect of the present invention. lot...outer cylinder 102...-inner cylinder 103...
...Armor door 104-...Rotary shaft 105...
Ceiling plate 106--Dispersion plate 108--Selection blade tti,--Main blade 112--Collision Fi
113...Chute 114.115-...Discharge chute

Claims (1)

[Scope of Claims] 1. A wind-powered powder granulator that forms an upward airflow in a housing formed by connecting a cone to the lower end of an upright cylindrical body with a sealed top, and classifies the powder using the airflow. In a body classifier, an upright cylindrical cage-shaped classification chamber is rotatably suspended in a housing with a gap between the inner surface of the housing and the inner surface of the housing. A classification device comprising a sorting blade and a disc-shaped dispersion plate disposed in the upper part of the chamber, forming an air circulation passageway for receiving the rising airflow and guiding it to the gap through the sorting blade. 2. The classification device according to claim 1, wherein each of the plurality of sorting blades is rotatable at an arbitrary angle around an axis parallel to the cylindrical axis. 3. The classification device according to claim 1 or 2, wherein the sorting blade is divided into a plurality of stages in the axial direction of the cylinder.