JP2001293438A - Classifying machine and fine powder manufacturing system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a classifying machine with which the pulverization of classifying materials is averted, the classifying materials are adequately dispersed between classifying areas and in some cases, the lumps existing in some places are loosened and the classification may be executed in a distinct grain size range and a fine powder manufacturing system using the same. SOLUTION: The classifying machine has two impeller type classifying rotors which are supported on one side within one casing and may be driven by motors. The respective classifying rotors have cover disks closed at the first end in their axial direction and have mechanisms for taking out the fine granular materials or middle granular materials at the second end in their axial direction. At this time, the first ends of both of the classifying rotors are so arranged that the end faces are opposed to each other, by which fluid spaces are formed in the axial direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a classifier for classifying a granular material into a plurality of classified materials, and a fine powder production system using the same.

[0002]

2. Description of the Related Art Conventionally, as a classification means for classifying a crushed raw material into fine particles and coarse particles, a classification object is rotated by a cylindrical classification rotor which rotates around a central axis extending in a vertical direction. A vertical axis type in which classification air is flowed from the outside to the inside in the radial direction of the classification rotor into the classification space formed around the classification rotor, and the fine particles are transported into the classification rotor together with the classification air flow to be classified. The air-flow classifier is used.

In a conventional classifier of this type, the classifier rotor is housed in a casing having an opening on the upper surface, and a drive shaft for driving the classifier rotor and a member connecting the drive shaft to the classifier rotor are located above the classifier rotor. Are located in The objects to be classified are supplied from above the classification rotor, uniformly distributed over the entire circumference by a top wall closing the upper surface of the classification rotor, and supplied into the classification space. The fine particles conveyed into the classification rotor are deflected axially downward in the classification rotor, discharged from the classification rotor, and received by the fine particle discharge chamber. Further, the coarse particles in the classification space fall down due to gravity and are received by the coarse particle discharge chamber.

[0004] Further, in the case where a granular material is classified into at least three classified materials such as a fine granular material (fine powder), a medium granular material (medium powder), and a coarse granular material (coarse powder), the classification range is limited. In order to perform classification in which a plurality of so-called multi-stage classifications are performed so that each classified material is divided into a clear particle size range, usually, a plurality of individual classifiers are used.

[0005] These classifiers are connected to one another in a single process facility by means of a classifier conveying device, for example a pipe conduit. It is believed that this allows the classifieds to be sufficiently dispersed again in the classified air during transport from one classifier to another. This is also necessary as a prerequisite for completely classifying the classification in the next classification zone.

On the other hand, when a plurality of classification zones are combined in one classifier casing, as described above,
It is not possible to adopt a configuration in which the classification material is dispersed in the pipe. Therefore, as another means for dispersing the classification material between the two classification zones, a second classification below the first classification zone is performed.
In the transition to the classification area, it has been proposed that the transition area is formed in a hopper shape so that the classified material is rolled and loosened.

In another configuration, a blade or a disk for dispersing particulate matter is attached near the opening of the hopper so that a lump of granular matter is loosened. . In order to cope with wear caused by the collision of the granular material, a collision plate having a high abrasion resistance is attached to the inner wall surface of the casing.

[0008]

However, in the above-mentioned conventional structure, the classified material can be loosened and dispersed, but the particles of the granular material strongly adhere to the inner wall surface of the casing and adhere to it. The defect that a lump is reformed also arises. At this time, if the granular material to be classified is extremely fragile, and only the fine particles are not the desired classified material, that is, for example, when producing a toner, the granular material itself may not be crushed during the classification. Not desirable.

In view of the above problems, the present invention avoids the pulverization of the classified material, disperses the classified material appropriately between the classification regions, loosens the existing mass in some cases, and clarifies the mass. An object of the present invention is to provide a classifier capable of performing classification in a particle size range, and a fine powder production system using the classifier.

[0010]

In order to achieve the above object, the present invention provides a classifier for classifying pulverized powdery raw material, comprising a plurality of impeller-type classifying rotors coaxially in one casing. And the number of rotations of each classifying rotor can be set to be the same as or different from each other, and a plurality of classes corresponding to each classifying rotor can be simultaneously classified. Further, a minute flow space is formed in the axial direction between the ends of the classifying rotors facing each other.

Alternatively, there is provided a classifier for classifying pulverized powdery raw material, comprising two impeller-type classifier rotors supported on one side in one casing and driven by a motor. The classifying rotors each have one tangentially open classifying air supply, which is arranged at the level of each classifying rotor and has a stationary guide vane ring. The guide vane ring is arranged at a radial distance from the circumference of the classifying rotor, and further has a classifier supply unit, a classifier takeout mechanism, and a classifying area. Through the area,
In a classifier in which the classifier flows in the direction of the axial extension of the classifier rotor, each classifier rotor has a cover disc closed at its axial first end, and its axial second end. At the two ends, there is a mechanism for removing fine or medium particles, wherein both first ends of the classifying rotor are arranged such that their end faces face each other and form a flow space in the axial direction. It is characterized by doing.

Further, the powder raw material is a resin or a powder containing a resin. Alternatively, the powder raw material is a toner.

Further, a fine powder production system using the classifier is configured.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a classifier according to one embodiment of the present invention. FIG. 1A is an overall vertical sectional view, and FIG. 1B is an enlarged view of a flow space.

The classifier 1 shown in FIG. 1A comprises a casing which can be divided and which can be opened and turned via a hinge 2, and this casing is composed of an upper casing half 3
And a lower casing half 4 for accommodating classifying rotors 5 and 9, respectively. FIG. 3 shows a state in which the casing half is closed. The classifying rotor 5 has a drive shaft 7 in the upper casing half 3 and a bearing 6.
It is rotatably fitted within. The classification rotor 5 is driven by a drive motor 8, which is connected to the classification rotor 5 via a drive shaft 7.

Similarly, a lower casing half 4 which is symmetrically opposed to and coaxial with the upper casing half 3.
, The classifying rotor 9 has its drive shaft 10 rotatably fitted in the bearing 11. The driving of the classifying rotor 9 is performed by a drive motor 12.
2 is connected to the classifying rotor 9 via the drive shaft 10.

Each of the classifying rotors 5 and 9 is a classifying rotor whose one side is supported, and has a drive shaft 7 and a driving shaft 7, respectively.
0, fine-grain removal chambers 14 and 13, and bearing 6
And 11 are located on the same side. It also has closed cover disks 16 and 15 on opposite sides.

A short pipe 17 is arranged above the classifying rotor 5, through which granular material to be classified is loaded from one location in the circumferential range. An outlet short pipe 18 for coarse particles is arranged below the classification rotor 9.
The supply of the classification air is performed via the classification air supply units 19 and 20 which are open on both tangential sides on the circumference of the classification rotors 5 and 9.

The classifying rotors 5 and 9 are arranged coaxially and symmetrically facing each other in the classifier 1, and the respective cover disks 16 and 15 are spaced apart and are in planes parallel to each other. In this state, the classification rotors 5 and 9 rotate in the same direction. By adjusting the number of rotations of the classifying rotors 5 and 9 to be the same, it is possible to classify into fine particles and coarse particles. Further, by adjusting the number of revolutions of the classifying rotors 5 and 9 to be different, for example, fine particles can be obtained from the fine particle take-out chamber 14, medium particles can be obtained from the fine particle take-out chamber 13, and from the outlet short pipe 18, Coarse-grained substances can be respectively taken out.

The classifying rotors 5 and 9 may be configured to rotate in opposite directions. The structure of each classifying rotor and its surroundings is described in, for example, JP-A-11-21.
This is the same as that described in the embodiment in Japanese Patent No. 6425. Furthermore, the present invention is not limited to the configuration of the above-described embodiment, but includes a plurality of impeller-type classifying rotors coaxially in one casing, and each classifying rotor is set to have the same or different rotation speed. It is possible to adopt a configuration in which classification of a plurality of stages corresponding to each classification rotor can be performed at the same time. The shape of each of the plurality of classifying rotors, that is, for example, the length, the outer dimensions, the number and shape of the blades, may be the same or different.

As described above, there has not been a classifier having a rotary classifying blade, that is, a classifying rotor, which can simultaneously perform a plurality of stages of classification with one machine as in the present invention.
Further, there is a type which does not have a classification rotor and performs classification in a plurality of stages, but there has not been a classifier capable of performing a sharp classification including an effect of dispersing agglomerated powder. Therefore, the classifier of the present invention is optimal when classifying powder having a small particle size and a narrow particle size range of a product such as a toner or a powder coating.

By the way, a flow space is formed between the cover disks 16 and 15. This flow space is shown in FIG.
Part (b) is partially enlarged. This is a detailed view of a portion A surrounded by a dashed line in FIG. In FIG. 4B, g represents classified particles, which fall downward along the outer circumference of the classification rotors 5 and 9. At this time, due to the rotation of the classifying rotors 5 and 9 and the respective cover disks 16 and 15, as shown by the arrow B, the air in the flow space is brought near the walls of the rotating cover disks 16 and 15. It is extruded outward, where it pulls in the classified particles g and carries them into the flow space for dispersion.

FIG. 2 is a view showing an opening stage of the splittable casing by opening and turning. FIG. 11A shows a state where the opening is started, and FIG. 10B shows a state where the opening is completely completed. As shown in the figure, the classifier 1 here is
The casing half 3 and the casing half 4 can be pivoted at least 180 ° via the hinge 2 so as to be pivotable.

FIG. 3 is a view showing an opening stage of the splittable casing by sliding and opening and turning. FIG. 7A shows a closed state, FIG. 7B shows a state of opening by sliding, and FIG. 7C shows a state of opening by turning. As shown in FIG.
In the first embodiment, the casing half 3 and the casing half 4 can slide and open and rotate via the sliding portion s and the hinge 2.

Here, in the state of completely opening and turning,
The classifying rotor can be pulled up by simply removing it from the drive shaft and removed from the casing. Since the entire casing structure does not have an undercut portion, quick, easy and reliable cleaning is possible.

FIG. 4 is a diagram showing a classifier of a type in which a first classifying rotor is driven by a second classifying rotor via a coupling. FIG. 1A shows a closed state, and FIG. 1B shows a state where the opening is started by turning. In the classifier 1 shown in the figure, the upper classifying rotor 5 does not have a unique drive motor. The classifying rotor 5 is connected to the coupling 2 on the cover disks 16 and 15.
1 is connected to a classifying rotor 9 driven by a drive motor 12.

FIG. 5 is a diagram showing a classifier of a horizontal arrangement type. FIG. 1A shows a closed state, and FIG. 1B shows a state where the opening is started by turning. In this figure, a short pipe 17 for charging a classifier and an outlet short for removing a coarse substance are advantageous for operating the classifier 1 with the axial direction extending horizontally. The arrangement of the tube 18 is shown.

FIG. 6 is a view showing a charge distributor having a built-in body for distribution and dispersion of the classified material, and FIG.
1 is an overall longitudinal sectional view, and FIGS. 2B and 2C are explanatory views of a charge distributor. As shown in FIG. 2A, in the charge distributor 22 which is a portion surrounded by a solid line, a ring disk 24 is connected to the classifying rotor 5 so as to rotate coaxially inside a ring passage 23. I have.

As shown in FIG. 2B, the charge distributor 22 is provided with a step 25 in the wall of the casing. The blade elements 26 uniformly arranged along the circumference of the ring disk 24 are attached to the lower side of the ring disk 24. Further, as shown in FIG. 3C, an additional blade element 27 may be attached to the upper side of the rotating ring disk 24.

FIG. 7 is a graph showing a comparison of the particle size distribution of coarse powder (product) when the toner is classified by the classifier according to the present invention and the conventional classifier. Here, the horizontal axis indicates the particle size (unit: μm), and the vertical axis indicates the number-based frequency. The classifier according to the present invention is generally called a TTSP (tandem toner separator), and the diameter of the upper and lower classifier rotors is 200.
mm. Here, the rotation direction and the rotation speed of each classifying rotor are the same.

On the other hand, the conventional classifier uses a so-called TSP (toner separator), and a single classifier rotor having a diameter of 315 mm is used. The raw material for comparison is a polyester color toner (magenta) having an average diameter of 7.6 μm. The yields of the product coarse powder were 75.8% for TTSP and 75.8% for TSP, respectively.
This is almost the same condition as 5.2%.

Under the above conditions, TTSP and TSP
, The toner was classified into fine powder and coarse powder, and the particle size distribution of the coarse powder to be a product was compared. In the figure, a curve a by a solid line is a graph by TTSP, and a curve b by a chain line is a graph by TSP. As shown in the figure,
TTSP has a narrower particle size range than TSP, and has a sharper particle size distribution. Further, the processing capacity at this time is 180 k for TTSP.
g / h (dust concentration 0.16 kg / m ³ ), TSP 15
0 kg / h (dust concentration: 0.11 kg / m ³ )
TSP is higher than TSP.

FIG. 8 shows a coarse powder (product) when the toner is classified by the classifier according to the present invention and the conventional classifier.
4 is a graph showing a comparison of the fine powder bypass ratios contained in.
The fine powder bypass ratio is a ratio of fine powder mixed into coarse powder. Here, the horizontal axis represents the particle diameter (unit: μm) of the partial classification efficiency of 50%, and the vertical axis represents the bypass ratio. The 50% particle diameter of partial classification efficiency is a particle diameter in which what is on the fine powder side and what is on the coarse powder side by classification is basically fifty-fifty. The dust concentration here is 0.13 kg / m ³ for both TTSP and TSP under the same conditions. The raw material for comparison is a polyester color toner having an average diameter of 6.9 μm.

Under the above conditions, TTSP and TSP
, The toner was classified into fine powder and coarse powder, and the bypass ratio of fine powder contained in the coarse powder as a product was compared. In the figure, a solid line c is a graph based on TTSP, and a dashed line d is a graph based on TSP. As shown in the figure, the TTSP has a smaller bypass ratio as a whole as compared with the TSP, and good results are obtained.

As described above, the classifier TTSP according to the present invention has experimentally obtained the following results as compared with the conventional classifier TSP. That is, since the diameter of the classifying rotor is small, the centrifugal force on the classifying material acts strongly,
Thereby, the classification accuracy is high (the particle size distribution is sharp). Also, the longer the classifying rotor length, the longer the residence time of the raw material, so that the mixing ratio of the fine powder into the coarse powder is reduced. In addition, classification accuracy is high (sharpness of particle size distribution) by increasing dispersion force in the flow space.
Has become. As a result, the product (coarse powder) yield is improved. Further, with the high classification accuracy as described above, processing can be performed even at a high dust-containing concentration, and high processing performance is obtained.

That is, the classifier according to the present invention can obtain higher performance in terms of classification accuracy, product (coarse powder) yield, and processing capacity than conventional classifiers. Further, by adjusting the number of revolutions of the upper and lower classifying rotors, three types of powders, fine powder, medium powder, and coarse powder, can be obtained at the same time, which has an ideal structure as a toner classifier. Here, the target toner includes not only pulverized toner but also polymerized toner. Further, the present invention can be applied not only to the toner but also to a powder coating material, and furthermore, generally, a resin raw material, in particular, a thermoplastic resin raw material is a target range.

FIGS. 9 and 10 show a fine powder production system (toner production system) equipped with the classifier according to the present invention.
FIG. 3 is a block diagram of one embodiment of the present invention. These systems include a pulverizing means 31 for pulverizing the raw material and a classification means 32 for classifying the pulverized raw material to a particle size. Crushing means 31
A well-known air-flow type pulverizer or mechanical pulverizer is used. The classifier 32 is a classifier according to the present invention.

In the system shown in FIG. 9, the classification means 32 converts the raw material pulverized by the pulverization means 31 into a coarse powder having a particle size larger than a specified particle size, a medium powder (product) within the specified particle size, and a Particle size classification into fine powder of small particle size. The coarse powder is pulverized again by the pulverizing means 31 and supplied to the classifying means 32 again. The fine powder is collected and returned to the raw material mixing step. In the system of FIG. 10, the classification means 32 used is the same as that of FIG. 9, but here, the raw material pulverized by the pulverization means 31 is divided into coarse powder (product) within a specified particle size and smaller than the specified particle size. Particle size classification into fine powder of particle size. The fine powder is collected and returned to the raw material mixing step.

As the pulverizing means 31, in the case of an air-flow type pulverizer, a trade name of a counter jet mill (Hosokawa Micron Corp.), a supersonic jet mill (IDS type, PIJ type,
PJM type (Nippon Pneumatic Industries, Ltd.), cross jet mill (Kurimoto Iron Works, Ltd.) and the like can be used. For mechanical pulverizers, the brand names Inomaizer (Hosokawa Micron Corp.), Kryptron (Kawasaki Heavy Industries, Ltd.), Turbo Mill (Turbo Kogyo Co., Ltd.), Super Rotor (Nissin Engineering Co., Ltd.), Fine Mill ( Nippon Pneumatic Industries, Ltd.) can be used. Whichever pulverizer is used, good classification performance can be obtained for the pulverized raw material by the classifier according to the present invention as the classification means 32.

[0040]

As described above, according to the present invention,
A classifier capable of avoiding the pulverization of the classified material, dispersing the classified material appropriately between the classification regions, loosening any existing lump, and performing classification in a clear particle size range, and It is possible to provide a fine powder production system using the same.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a classifier according to an embodiment of the present invention.

FIG. 2 is a view showing an opening stage by opening pivoting of a splittable casing.

FIG. 3 is a diagram showing an opening stage by sliding and opening swing of a splittable casing.

FIG. 4 shows that the first classifying rotor is connected to the second classifying rotor via a coupling.
The figure which shows the classifier of the type driven by the classification rotor of FIG.

FIG. 5 is a view showing a classifier of a horizontal arrangement type.

FIG. 6 shows a charge distributor having a built-in body.

FIG. 7 is a graph showing a comparison of a coarse powder (product) particle size distribution.

FIG. 8 is a graph showing comparison of bypass ratio of fine powder contained in coarse powder (product).

FIG. 9 is a block diagram of an embodiment of a fine powder production system according to the present invention.

FIG. 10 is a block diagram of an embodiment of a fine powder production system according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Classifier 2 Hinge 3 Casing half 4 Casing half 5,9 Classifying rotor 6,11 Bearing 7,10 Drive shaft 8,12 Drive motor 13,14 Fine particle removal chamber 15,16 Cover disc 17 Short pipe 18 Short outlet pipe 19, 20 Classification air supply unit 21 Coupling 22 Charge distributor 23 Ring passage 24 Ring disk 25 Step 26 Blade element 27 Additional blade element 31 Crushing means 32 Classification means

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Georg Konetska Augsburg Hans-Lup-Weg 5 Germany (72) Inventor Yoshiyuki Inoue 67-3 Kamioba Hachiojincho, Minami-ku, Kyoto, Kyoto, Japan

Claims (6)

[Claims] 1. A classifier for classifying pulverized powder raw material, comprising a plurality of impeller-type classifier rotors coaxially in one casing, wherein each classifier rotor has the same or different rotation speed. A classifier capable of simultaneously setting a plurality of stages corresponding to the respective classifying rotors. 2. A classifier for classifying pulverized powdery raw material, comprising two impeller-type classifier rotors that are supported on one side in one casing and can be driven by a motor. The classifying rotors each have one tangential classifying air supply, which is arranged at the level of each classifying rotor and has a stationary guide vane ring, The guide vane ring is arranged at a radial distance from the circumference of the classifying rotor, and further includes a classifier supply unit, a classifier takeout mechanism,
A classifier having a classifier zone, through which the classifier flows in the direction of the axial extension of the classifier rotor, wherein each classifier rotor is closed at its first axial end. And at the second axial end thereof a mechanism for removing fine or medium particles, wherein both first ends of the classifying rotor have their end faces facing each other. A classifier which is arranged to face each other and forms a minute flow space in the axial direction. 3. The classifier according to claim 1, wherein a minute flow space is formed in an axial direction between ends of the classifying rotors facing each other. 4. The classifier according to claim 1, wherein the powder raw material is a resin or a powder containing a resin. 5. The classifier according to claim 1, wherein the powder material is a toner. 6. A fine powder production system using the classifier according to any one of claims 1 to 5.