JPH06238197A - Cyclone device - Google Patents

Abstract

PURPOSE:To easily change a classification point of coarse powder and fine powder, in a cyclone device used for a classification device, etc., of powder. CONSTITUTION:There are provided a space forming block 38 confronted to make a sharp conical top part face toward the inside of a drum cylinder from the lower side against a circular opening 381 at the bottom end of the drum cylinder 33 and forming an annular space between them; and a lifting mechanism for adjustment of a space opening enabling to shift the position of the space forming block in the up-and-down direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for selecting powder having a particle size distribution according to the particle size, and more specifically, to separate coarse powder and fine powder in the powder for dust collection or classification. The present invention relates to a cyclone device used for collecting coarse powder, more specifically, a classifying device or a dust collecting device.

[0002]

BACKGROUND OF THE INVENTION Recently, as a useful inorganic filler for the purpose of improving or improving the functions such as abrasion resistance and abrasion resistance of products, or as an agent itself as a chemical carrier, In the field of handling powders of inorganic substances such as ceramics and organic substances, such as the field where products are independently produced, etc., not only the selection of material type is required due to the demands for high precision technology and high quality products. It is becoming very important to study the physical and chemical properties of the selected material from various perspectives.

Among these, the particle size is 1 μm or less μm
In the field of handling powders of a level or lower, for example, the size of the surface area of the powder often has a great influence both physically and chemically on the technical problem to be achieved, One of those directly related to this is the particle size and particle size distribution of the materials used. For example 1
When using a powder distributed in the range of 100 μm,
It is common in various fields that there is a large difference in the expected effect when powders having a distribution of 5 μm are used.

The importance of such a problem is well known in the technical field of handling fine powders, and therefore, for the purpose of adjusting the particle size distribution of powders used in various fields. In the past, various classifying devices have been proposed. For example, a rotary rotor classifier that classifies coarse powder and fine powder by the action of a forced centrifugal force using a rotating rotor and the action of an inward air flow that opposes this centrifugal force,
Cyclone type classifiers and the like utilizing the principle of cyclone tower have been proposed. It is known that the latter of these, the cyclone type classifier, has the advantages that the structure is simple, there are no moving parts such as the rotating rotor, and the burden of maintenance and inspection is small.

FIG. 4 shows an outline of the construction of a conventional example of this cyclone type classifying apparatus. In the figure, reference numeral 1 denotes a powder feeder, which stores the powder to be classified and is continuously fed by a feeder screw 2. Then, the powder is supplied to the powder transfer pipe 3. Pressurized air is sent from the valve 4 to the powder conveying pipe 3, and the supplied powder is blown into the powder introducing portion 6 of the cyclone tower 5.

The cyclone tower 5 has an upright cylindrical shape and is composed of an upper straight tube portion 5a and a lower inverted frustoconical portion 5b, the lower end of which opens into a coarse powder recovery box 7. Further, from the ceiling of the cyclone tower 5, a primary air take-out cylinder 9 for taking out fine powder is hung down to a position of a certain height inside the tower, and its lower end is opened, so that a negative pressure is applied inside the tower. Has been. Reference numeral 10 is a filter connected to the outside of the primary air extraction cylinder 9 for collecting fine powder, and is connected to a suction pump 13 through an air flow meter 11 and an opening / closing valve 12.

The above cyclone apparatus is also generally used as a dust collector for collecting as much dust as possible from a gas containing dust and reducing the amount of dust in the air discharged to the atmosphere. Widely used.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to improve a conventional classifying device and dust collecting device using the cyclone device as described above.

For example, in a cyclone type classifier, a vortex flow is generated in the cyclone tower by blowing air containing powder, and the magnitude of the centrifugal force given to the powder in this vortex flow and Due to the balance of the upward suction force acting on the center of the vortex from the primary air take-out tube 9, the coarse powder having a large particle size is further subjected to the action of the centrifugal force of the former and gradually moves downward while staying in the vortex. The powder moves to the coarse powder recovery box 7 at the lower end, and the fine powder is more greatly affected by the suction force of the latter, and is recovered by the filter 10 from the primary air extraction cylinder 9 at the upper part. Therefore, the coarse powder and the fine powder are selected accordingly.

By the way, one of the factors that determines the limit (so-called separated particle size or separated size) for separating coarse powder and fine powder in a cyclone is the size ratio (ratio of the length of each part) of the cyclone tower, In addition, the blowing wind speed is generally mentioned as another factor. Therefore, in order to change the separated particle size, it is necessary to replace the cyclone tower itself, or it can be done by changing the operating conditions that change the blowing air velocity and suction force, but the former is practically impossible. However, in the latter case as well, since it is actually difficult to greatly adjust the separated particle size by changing the wind speed and the like, there has been no example of adopting such a system as a classifying device.

Further, even when it is used as a dust collector, it cannot be easily dealt with even if the use conditions are changed and the collection particle size needs to be changed. Will need to be changed.

The present invention improves the present state of the art and provides a new proposal for the problems that cannot be solved by the prior art. One of the objects is to provide a conventional cyclone device. A device that can relatively easily change the separation particle size of fine powder and coarse powder that could not be realized,
Particularly, it is to provide a cyclone device which has a simple structure and is easy to perform maintenance and inspection, and therefore has a low so-called classification cost.

Another object of the present invention is to propose a classifying device equipped with such a cyclone device.

[0014]

For the above-mentioned purpose, the present inventors have found that the upper straight tube portion and the lower reverse tube which is continuous downward from this straight tube portion and whose diameter gradually decreases toward the lowermost end. A cyclone tower having a barrel formed of a truncated cone portion, and a powder introduction guide portion of the cyclone tower provided so as to blow the air flow containing the dispersed powder along the inner peripheral wall from the vicinity of the upper end of the straight cylinder portion, It is connected to the circular opening at the bottom of the barrel of the cyclone tower in order to recover coarse powder with a large particle size that settles on the vortex formed by the blown air flow swirling along the inner wall of the barrel. Coarse powder collecting means, and a fine powder collecting means that hangs a fixed length from the central position of the upper part of the barrel of the cyclone tower into the straight cylindrical part and has a lower end opened, and exerts a weak negative pressure on the central part of the vortex flow from above. In the cyclone device, A block for forming a gap and a block for forming a gap that forms an annular gap between them so as to face the circular opening of the conical sharp top from the lower side toward the inside of the barrel. A cyclone device was completed, which was provided with a vertical movement mechanism for adjusting the opening degree of the gap, which was capable of being vertically displaced.

According to the cyclone device of the present invention having the above structure, it is possible to provide a classifying device which can easily change the classification point by using the cyclone device.

The structure of the present invention is adopted based on the fact that the effects described in the following embodiments are experimentally confirmed.

In the present invention, an appropriate means for collecting the powder (coarse powder) that has passed through the gap, such as a conventional coarse powder recovery box, may be provided outside the gap forming block. It is preferable, however, that instead of providing such a box, one end of a pipe for directly carrying the coarse powder to another device may be connected. When a coarse powder recovery box is provided, for example, a configuration is provided in which the box that stores the powder that has passed through the gap and that can be opened as needed is provided around the block in a circumferential shape. It can be illustrated.

In the present invention, the conical gap opening adjustment block is vertically moved by, for example, a screw mechanism or a hydraulic mechanism with respect to the circular opening at the lower end of the inverted frustoconical shape forming the lower part of the barrel. It is preferable to adjust the distance between the lower circular opening and the block (the distance between them) is proportional to the size of the vertical movement due to the shape and size of the block. Given. The relationship between the size of the gap between the circular opening at the bottom of the barrel and the block and the size of the separated particles varies depending on the size ratio of the cyclone device and the blowing wind speed, etc., so the adjustment range can be determined by design or experimentally. . In addition, it is desirable that the size of the gap between the circular opening and the block be uniform in the circumferential direction. The apex angle of the conical block is not particularly limited, but is generally 40 to 90 °, preferably 6
The shape is preferably 0 to 90 °, particularly about 90 °.

The circular opening at the lower end of the barrel does not have to be directly connected to the coarse powder recovery box, and it suffices if another suitable sealing mechanism is provided.

INDUSTRIAL APPLICABILITY The present invention can be sufficiently applied to a cyclone tower having a dimensional ratio designed according to the conventional air volume and dust content.

The size of the gap is not particularly limited, but is generally 1 mm to 20 mm, preferably 3 mm.
mm to 6 mm is sufficient.

In the above construction, the type of cyclone tower is not particularly limited, and it can be applied to any type of cyclone device.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the embodiments shown in the drawings.

In this embodiment, the cyclone tower 31 shown in FIG. 1 is applied to the cyclone device explained in FIG. 4, and in the embodiment explained in this figure, only this cyclone tower 31 is used. The other parts are omitted.

In this figure, reference numeral 31 is a cyclone tower having an upright cylindrical barrel, which is composed of an upper straight tube portion 32 and an inverted frustoconical portion 33 which is continuous substantially downward from this. In addition, an arc-shaped guide wall surface 33 whose radius gradually increases outward from the wall surface of the straight cylindrical portion is provided in a certain range of the upper end portion of the straight cylindrical portion 32 over substantially one circumference, and forms the powder introduction portion 34. is doing. This powder introduction part 3
4 is the same as the conventional cyclone tower.

Reference numeral 35 denotes a coarse powder recovery box connected so that the circular opening 331 at the lower end of the inverted truncated cone-shaped portion 33 of the barrel is exposed, and 36 is hung from the center of the top surface of the cyclone tower into the barrel for a certain length. It is a fine powder extraction cylinder, and a constant negative pressure is applied from the outside in order to take out the fine powder, as in FIG.

In addition to the above-mentioned structure, in this embodiment, a circular opening 351 (up to this embodiment) opened toward the upper part of the coarse powder recovery box 35 connected to the lower end of the inverted truncated cone 33. Then, a conical block 38 is provided so as to face the circular opening 331 at the lower end of the inverted truncated cone portion 33), and the block 38 is vertically movable by a vertical movement mechanism (not shown). Thus, the gap between the circular opening 351 and the circular opening 351 can be freely adjusted.

That is, by vertically moving the block 38, the circular opening 351 (331) connecting the inverted frustoconical portion 33 and the coarse powder recovery box 35 and the annular clearance between the blocks 38 are adjusted to be wide or narrow. To be done.

In order to confirm the classification performance of the cyclone type classifying apparatus having the above constitution, a classifying test was conducted using a cyclone type classifying apparatus constructed so as to have the following dimensional relationship.

Structure of Cyclone Tower Diameter of the straight tube portion 32 of the cyclone tower ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 72 mm φ Same vertical dimension ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 150 mm Opening at the lower end of the inverted truncated cone 33 of the cyclone tower The vertical dimension of the inverted frusto-conical shaped portion 33 of the same diameter of 40 mmφ: 180 mm The maximum diameter of the powder introduction portion 34: The vertical dimension of the same of 37 mmφ・ ・ ・ ・ ・ ・ ・ ・ 17 mm Diameter of the fine powder extraction cylinder 36 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 40 mm Same drooping length: S = ・ ・ ・ ・ ・ ・・ ・ ・ 100mm Diameter of conical block 38 ・ ・ ・ ・ ・ ・ ・ ・ 40mm Same apex angle ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 90 ° Classification test 1 Powder included body blow velocity (powder transfer pipe) of the air flow 43.0m / s blown powder (fly ash) · · · · (D _{p 11μm, ρ p = 2.2g / cc} ) a powder blowing amount ............. 180 g / hr (3 g / min) or more tests, inverted truncated cone shape of the cyclone tower Part 3
3 to the lower end circular opening 331 of the conical block 3
Table 1 and FIG. 2 below show the test results obtained by moving 8 up and down to change the gap h (3 to 6 mm).

[0031]

[Table 1]

This test shows the partial separation efficiency of the blown powder when the gap is changed. The particle size at 50% of the partial separation efficiency was used as the classification point. This partial separation efficiency is
It shows how much more than the particle size is mixed for each particle size, and is generally used for obtaining classification points such as air classification.

From FIG. 2, it can be seen that the classification point becomes smaller as the gap between the conical block 38 and the lower circular end opening 331 of the inverted truncated cone portion 33 becomes larger.

Table 2 and FIG. 3 below show the results when the blowing air velocity was increased for the same cyclone.

[0035]

[Table 2]

From the results of these classification tests, it became clear that the cyclone device of the present invention can exhibit an excellent effect of changing the classification point which has not been found in the past.

The present invention is not limited to the apparatus of the above embodiment, and it goes without saying that the dimensions of each part can be changed.

[0038]

As described above, according to the cyclone device of the present invention, it is possible to change the classification point, which has been extremely difficult to realize with the conventional cyclone device, with a simple mechanism.

Further, by using such a cyclone device, there is an effect that it is possible to provide a cyclone type classifying device having high classification accuracy and capable of changing a classifying point, and moreover, because of its simple structure and easy maintenance and inspection. Therefore, there is an effect that a cyclone device with low equipment and operation costs can be provided.

Furthermore, the present invention has an effect that it can be suitably used for a dust collector.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the outline of the configuration of a cyclone column portion of an embodiment of a cyclone type classifying device according to the present invention.

FIG. 2 shows partial separation efficiency in the case of classification according to the same Example 1.

FIG. 3 shows the partial separation efficiency of Example 1 when the blowing air velocity is 33 m / s.

FIG. 4 is a diagram showing a general configuration outline of a cyclone type classifying apparatus to which the present invention is applied.

[Explanation of symbols]

1: Powder feeder, 2: Feeder screw, 3:
Powder transfer pipe, 4: Valve, 5: Cyclone tower, 6: Powder introduction part, 7: Coarse powder recovery box, 9: Primary air extraction cylinder, 10: Filter, 11: Air flow meter, 12: Open / close valve, 13 : Suction pump, 31: Cyclone tower, 32: Straight tube part, 33: Inverted frustoconical part, 34: Powder introduction part, 3
5: Coarse powder recovery box, 36: Fine powder extraction cylinder, 37: Standing wall, 38: Conical block.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hideto Yoshida 981-206 Otani, Takayacho, Higashihiroshima City, Hiroshima Prefecture (72) Inventor Yukiyoshi Yamada 3-6-18 Hachiman, Kawashima-cho, Hiki-gun, Saitama Prefecture (72) Inventor Fuyuki 2-23-16 Midorigaoka, Oi-cho, Iruma-gun, Saitama Prefecture

Claims (2)

[Claims] 1. A cyclone tower having an upper straight tube portion and a barrel tube formed of a lower inverted frustoconical portion which is continuous downward from the straight tube portion and whose diameter gradually decreases toward the lowermost end, and a dispersed powder. Formed by the powder introduction guide part of the cyclone tower, which is provided so as to blow the contained airflow from the vicinity of the upper end of the straight cylinder along the inner peripheral wall, and the blown airflow swirls along the inner peripheral wall of the barrel. The coarse powder recovery means connected to the circular opening at the lower end of the cylinder of the cyclone tower to recover the coarse powder having a large particle size that settles on the vortex flow, and the straight cylinder from the central position of the upper cylinder of the cyclone tower. In a cyclone device having a fine powder collecting means that acts on the center of the vortex by a weak negative pressure from above in a central part of the vortex flow, a lower end of the circular opening at the lower end of the barrel Conical towards the inside of the barrel A block for gap formation that opposes the sharp apex to face each other and forms an annular gap between them, and a vertical movement mechanism for gap opening adjustment that allows the block for gap formation to be vertically displaced. A cyclone device characterized by having and. 2. A cyclone type classifying device comprising the cyclone device according to claim 1.