JPS5822274B2 - Classifier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a classification device for separating classified raw materials into fine powder and coarse powder.

Generally, in the crushing department of cement manufacturing plants, a closed circuit system using a combination of an old tube mill and an air separator has been established.

In this crushing department, a large amount of electric power is used during the cement manufacturing process, and various improvements have been made to improve crushing efficiency, classification efficiency, etc. in order to reduce this consumption.

Among these, increasing the amount of air passing through the mill is one of the effective means.

Conventionally, the amount of air passed through the mill was only the necessary limit to prevent blowing from the mill, but by actively flowing several times the amount of air (hereinafter referred to as air sweep reinforcement), the cooling effect of the cement is increased and the cement is superimposed. This has the effect of preventing pulverization and preventing powder from adhering to small-diameter balls, resulting in improved pulverization efficiency and reduction in required power for pulverization.

However, in this case, the rate at which coarse powder is mixed into the exhaust gas increases, and a new mill exhaust classifier is required.

External cyclones, circulating fans, distributed air separators, and so-called cyclone-type air separators, which have been widely used in the cement industry, are used to classify powder that is not air swept, and mill exhaust classifiers must be considered separately.

It is conceivable to use an ordinary cyclone as this classifier.

Traditionally, cyclones have been used for dust collection, but they are also used for classification when very sharp precision is not required.

However, the classified particle size is determined in the range of approximately 1 to 20 μm depending on the size of the cyclone, so if the classified particle size needs to be adjusted over a wide range, or if the powder concentration exceeds 0.1 kg/m3, dispersion It is not appropriate to use a cyclone as a classifier when processing powder with a high dust content concentration because the classification accuracy is lowered due to insufficient cyclones.

In particular, when used as a mill exhaust classifier after strengthening the air sweep in the crushing department in the cement manufacturing process mentioned above, a large amount of fine powder that can be used as cement products is mixed into the coarse powder, and this is used as return powder in the mill. Returning it inward and re-grinding it is inefficient and uneconomical, and the effect of strengthening the air sweep mentioned above is also halved.

The first purpose of this invention is to eliminate the drawbacks of the above-mentioned cyclone, and to make it possible to sharply classify powder with high dust content concentration, which has an increased air volume after Air Swept reinforcement. It is also possible to classify raw materials simultaneously or individually, and conventionally it is possible to classify raw materials simultaneously or separately.

The object of the present invention is to provide a new classification device suitable for mass processing, which can replace the so-called cyclone air separator widely used in the industry.

The details will be explained below based on the drawings.

In FIGS. 1 and 2, 1 has an approximately cylindrical upper portion.

1a, the lower part of which is a substantially conical hopper 1b, and air and raw material 2 are provided in the tangential direction of the cylindrical portion of the casing 10.

The rotating vertical shaft 4 is provided to pass through approximately the center inside the casing 1, and the lower part of the rotating vertical shaft 4 has a cylindrical shape 1a of 1° in the casing.
A hollow rotary plate 5, which serves both dispersion and classification, is located almost at the boundary between the section and the conical hopper section 1b, and is mounted via spokes 5a, and as shown in the partially enlarged view of FIG. A substantially conical hole of the casing 1 is located adjacent to the hollow portion of the plate 5.

A fine powder discharge pipe 3 is provided passing through the inside of the collar 1b.

Guide vanes 7 for guiding air and raw materials to the classification chamber 6 are provided with multiple membranes on the entire circumference at equal intervals inside the casing 1 concentrically with the rotating vertical shaft 4. The angle can be adjusted freely.

9 and 10 are a secondary air intake port and a tertiary air intake port, respectively, and the secondary air intake port 9 is provided in the tangential direction of the cylindrical portion 1a of the casing 1 at a position approximately symmetrical to the air and raw material population 2, The tertiary air intake port 10 is attached to the conical hopper 1b portion of the casing 1.

In the figure, reference numeral 11 is an insertion damper attached to the fine powder discharge pipe 3, which performs a squeezing action to adjust the classification point or improve the classification accuracy.

12 is a pocket. Next, the operating state of the classification apparatus having the above configuration will be explained.

The rotating vertical shaft 4 and the rotary plate 5 mounted on the rotating vertical shaft 4 rotate together as a unit by driving a driving device (not shown).

On the other hand, the classified raw material is supplied with air at an appropriate speed from the air and raw material port 2 provided in the tangential direction of the cylindrical part of the casing 1, and is directed in a vortex by guide vanes 7 set at an appropriate angle. Flows into classification room 6.

If the amount of raw material relative to the air (hereinafter referred to as powder concentration) becomes too large and the amount of air is insufficient, the secondary air intake port 9
By supplementing with air and adjusting the powder concentration to an appropriate level, raw materials can be fed smoothly.

The rotating airflow of the raw material flowing into the classification chamber 6 in a vortex is strengthened by the rotating plate 5, and the raw material is simultaneously subjected to two contradictory forces: outward centrifugal force and radially inward air resistance. become.

If the particle size at which these two forces are balanced is called the classification point, then particles below the classification point, that is, fine powder, have greater inward air resistance than outward centrifugal force (so that they ride the air flow and move toward the center). The fine powder is moved, fed into the fine powder discharge pipe 3, and collected by a separately provided collector (not shown).

On the other hand, coarse powder having a particle size larger than the classification point is subjected to centrifugal force greater than the inward air resistance, and as it flows along the inside of the guide vane 7, it falls into the conical hopper of the casing 1, and some of the coarse powder also falls. reaches the pocket 12 from where it quickly falls directly into the conical hopper of the casing 1.

In the hopper, coarse powder is collected from the coarse powder outlet 13, but by introducing air through the tertiary air intake port 10,
It is possible to improve classification accuracy by dispersing fine powder that has adhered to coarse powder and mixed into the hopper, sending it upward, and re-classifying it.

FIG. 3 shows another embodiment of the invention.

That is, the classification apparatus shown in FIGS. 1 and 2 has a plurality of eddy current adjustment pieces 14 attached to the rotary plate 5, a partition plate 15 attached to the eddy current adjustment piece 14, and the classification chamber 6 divided into a plurality of chambers. This is what is shown.

Although this classification apparatus has the same classification principle as the classification apparatus shown in FIGS. 1 and 2, it is a larger classification apparatus and is suitable for processing a large amount of classified raw materials.

In other words, inside the classification chamber 6, the air containing powder flows from the outer periphery to the center in a vortex, but as the device becomes larger, it is difficult to generate the theoretically ideal vortex, and the number of rotations and the feeding of raw materials become more difficult. Even if the amount, particle size distribution, etc. are considered, turbulence occurs in the vortex flow, making accurate classification impossible.

The eddy current adjustment piece 14 and the partition plate 15 eliminate the above-mentioned drawbacks.

Even in large equipment, sharp classification is possible without causing turbulence in the vortex flow.

A plurality of these eddy current adjustment pieces 14 may be installed at equal intervals in the radial direction on the rotary plate 5, depending on the size of the classification device, the rotation speed of the rotary plate 5, etc., considering the desired classification point. The further the points are placed on the outside of the plate 5 in the radial direction, the finer the classification points can be.

Further, as shown in FIGS. 4 to 6, it is also possible to mount the eddy current adjustment piece 14 on the rotary plate 5 at any desired position and angle, and to set the desired classification point by adjusting this position and angle.

The partition plate 15 divides the classification chamber 6 horizontally into a plurality of chambers, which improves the classification accuracy by reducing the influence of displacement fluctuations in the vertical velocity of the vortex.

The number of chambers may be appropriately determined based on the size of the classification chamber 6, taking into account the classification point and classification accuracy.

By attaching this partition plate 15, it is easy to set up a classifier that can sufficiently accommodate restrictions such as the installation location and area of the classification device 2, and the size of the entire classification device can be reduced relative to the throughput of classified raw materials. Even if it is not excessively thick, sufficient classification accuracy can be obtained and it is economical.

Figure 7 shows a fine powder discharge pipe 3 located approximately in the center of the top of the casing 1.
' is provided to further increase the throughput of the classifier shown in FIG.

That is, the classification chamber 6 is enlarged in the vertical direction, and the vortex flow adjustment piece 1 is
4 and the partition plate 150, sufficient classification accuracy can be obtained without excessively increasing the overall size of the classifier, and as described above, a large amount of classified raw materials can be processed. If the fine powder discharge pipe 8 is made too thick, there will be a limit to the size of the fine powder discharge pipe 8, which will cause problems in the discharge of fine powder.

For this reason, in this classification device, the classification chamber 6 is partitioned by a shielding plate 19, so that fine powder with an appropriate concentration of powder can be discharged from the upper and lower directions of the fine powder discharge pipes 3 and 4, respectively.

Incidentally, it is preferable that the shielding plate 19 is provided with a gently sloped surface 19a in order to prevent the accumulation of fine powder after classification.

Here, in FIG. 7, shielding plates 19 are shown above and below the classification chamber 6.
Although each classification chamber 6 is equally provided with eddy current adjustment pieces 14 and partition plates 15, it goes without saying that the present invention is not limited thereto.

That is, the vortex adjustment piece 14 and the partition plate 15 may be set at different positions, angles, and numbers in the upper and lower classification chambers 6, or the vortex adjustment piece 14 and the partition plate 1 may be set in one classification chamber 6.
By not providing 5 at all, it is also possible to discharge fine powder having different classification points from the upper and lower two directions of the fine powder discharge pipes 3 and 3'.

Next, the classification apparatus shown in FIGS. 8 to 10 will be explained.

These classifiers have the same classification principle as the classifiers shown in FIGS. 2, 3, and 7, but by newly providing a raw material 16 at the top of the casing 1, they can be used other than the air sweep system described above. It is also possible to classify raw materials alone or a combination of these raw materials.

That is, in FIGS. 8 to 10, a raw material 16 is provided at the top of the casing 1, and rotates integrally with the rotating vertical shaft 4 and rotating plate 5 at a position where the raw material falls from the raw material inlet 16. A dispersion plate 17 is provided as shown in FIG.

Reference numeral 18 denotes a collision plate, and the raw material that has fallen onto the dispersion plate 17 collides with this collision plate 18, the direction is changed, and the raw material is sent from the entire circumference to the classification chamber 6.

That is, the raw material inputted from the raw material inlet 16 is dispersed by the rotation of the distribution plate 17, the direction is changed by the collision plate 18, and the raw material is sent from the entire circumference to the classification chamber 6, where it is separated from the air and the raw material from the raw material population 2. join with.

The principle of classification of the combined raw materials is the same as the classification apparatus shown above.

Further, the functions of the eddy current adjusting piece 14 and the partition plate 15 shown in FIGS. 9 and 10, and the function of discharging fine powder from the upper and lower directions shown in FIG. 10 are also the same.

As explained above, the classification device of the present invention is particularly useful in the cement manufacturing process, in which the mill exhaust gas with a high dust concentration, which has an increased air volume after strengthening the air sweep, together with the powder from the mill discharge from the crushing section, can be classified into one classifier. can be done simultaneously with the device.

It is capable of classifying thermal, air-swept-based raw materials alone, or ordinary raw materials that are not air-swept, and has a wider range of applications than the so-called cyclone air separator conventionally used in the cement industry.

Furthermore, it goes without saying that the classification apparatus of the present invention is not limited to the above-mentioned classification of cement.

That is, this classification device has a wide classification chamber 6, and by the action of the vortex adjustment piece 14 and the partition plate 150, it is possible to perform sharp classification, efficiently process a large amount of raw materials, and feed the raw materials.

amount, angle adjustment of the guide vanes 7, rotation speed of the rotating shaft 4, installation of the vortex adjustment piece 14 and partition plate 15, secondary air intake port 9
．． The amount of air from the tertiary air intake 10, and furthermore the damper 1
The classification point can be adjusted by the graining action, etc. of No. 1, and by the synergistic effect of an appropriate combination of these classification point operation conditions, it can be applied as a classification device capable of classifying over a wide range of tens of micrometers to several thousand micrometers.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show each embodiment of the classification device according to the present invention.
The figure is a cross-sectional view, Figures 2 and 3 are longitudinal cross-sectional views, Figures 4 to 6 are examples of mounting the vortex adjustment piece, Figures 7 to 10 are longitudinal cross-sectional views, and Figure 11 is a vertical cross-sectional view. 2, 3, 7.8 and 9.10 respectively show partially enlarged views of the fine powder discharge pipe close to the hollow part of the rotary plate. In the diagram: 1...Casing, 2...Air and raw material inlet, 3...Fine powder discharge pipe, 4...
...Rotating vertical shaft, 5...Rotating plate, 6...
Classification chamber, 7... Guide vane, 14... Vortex current adjustment piece, 15... Partition plate, 16... Raw material inlet, 17... - Dispersion plate, 18... Collision plate, 19... Shielding plate.

Claims (1)

[Scope of Claims] 1. A casing with a substantially cylindrical upper part and a substantially conical hopper in the lower part, an air and raw material inlet provided in the tangential direction of the cylindrical part of the casing, and a casing for guiding the air and raw materials to a classification chamber. It is equipped with a guide vane, a rotating vertical shaft installed approximately at the center within the cylindrical portion of the casing, and a rotating plate mounted on the rotating vertical shaft, and the fine powder discharge pipe is connected to the lower part of the rotating plate or both of the lower part of the rotating plate and the top of the casing. A classification device characterized by being attached to. 2. The classification device according to claim 1, wherein a plurality of eddy current adjusting pieces are attached to the rotary plate. 3. The classification according to claim 2, wherein a partition plate is attached to the eddy current adjustment piece to divide the classification chamber into a plurality of chambers. Device. 4 A casing with a substantially cylindrical upper part and a substantially conical hopper in the lower part, an air and raw material inlet provided in the tangential direction of the cylindrical part of the casing, and an air and raw material inlet for guiding the air and raw material to the classification chamber (with the guide vanes and the Casing: a rotating vertical shaft installed approximately at the center of the cylindrical part, a rotary plate mounted on the rotating vertical shaft, a raw material inlet attached to the top of the casing, and a rotating plate attached at a position where the raw material falls from the raw material inlet. A classification device characterized in that a fine powder discharge pipe is attached to the lower part of the rotary plate or to both the lower part of the rotary plate and the top of the casing. 5. A vortex adjustment piece with one end fixed to the rotary plate and the other end fixed to the dispersion plate. 6. The classification device according to claim 4, which is provided with a plurality of 6. The classification device according to claim 4, in which a partition plate is attached to the eddy current adjustment piece, and the classification chamber constituted between the dispersion plate and the rotary plate is divided into a plurality of chambers. Classifier according to item 5.