JPH07132241A - Pulverizer - Google Patents

Abstract

PURPOSE:To pulverize powder to specified fine particle diameter and to improve the pulverizing efficiency by introducing the powdery by pressure or suction force from an accelerating pipe for feeding a material to be pulverized, dividing and collecting fine powder by the Coanda effect and pulverzing coarse powder by an impact member. CONSTITUTION:A material to be pulverized dispersed and sucked into an accelerating pipe 3 is completely dispersed by a high speed air current from an air nozzle 10, and carried and accelerated by the high speed air current in the accelerating pipe 3 to form a supersonic speed solid-gas mixed flow. By the Coanda effect, the relatively fine powder flows on the wall side, and the relatively coarse powder flows near the center. By using such a phenomenon, the fine powder and the coarse powder are separated from each other by a classifying edge 6 near the outlet of the accelerating pipe 3. The fine powder is discharged from a fine powder discharge port 7. The coarse powder is subjected to the similar action and hits against an impact member 4 to be finely pulverized. Then, the pulverized material is further pulverized by the secondary impact at the wall of a pulverizing chamber 5. Depending on the circumstances, it is subjected to the tertiary impact and further pulverized until it is conveyed to an outlet part 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine pulverizer using a jet stream (high pressure gas). The present invention also relates to a finely pulverizing device for efficiently producing a toner or a colored resin powder for a toner used in an image forming method by electrophotography.

[0002]

2. Description of the Related Art In general, a fine pulverizer using a jet stream is prepared by placing a crushing raw material on a jet stream to form a particle mixed stream and then injecting it from the outlet of an accelerating tube, and the particle mixed stream is forward of the outlet of the accelerating tube. The crushing material is made to collide with the collision surface of the collision member provided in the above, and the crushing raw material is finely pulverized by the impact force. The details will be described below based on the conventional fine pulverizer shown in FIG. In the conventional fine pulverizer, a collision member 84 is provided so as to face the outlet 83 of the accelerating pipe 82 to which the high-pressure gas supply nozzle 81 is connected, and the high-pressure gas supplied to the accelerating pipe 82 causes a flow to the middle of the accelerating pipe 82. The pulverized raw material is sucked into the accelerating pipe 82 from the pulverized raw material supply port 85, which is communicated from the direction, and is jetted together with the high-pressure gas to collide with the collision surface 88 of the collision member 84, and crushed by the impact. It is a thing.

[0003]

[Problems to be solved by the invention] However,
In the above-mentioned conventional example, since the pulverized raw material supply port 85 communicates with the middle of the accelerating pipe 82 and is provided at only one place, the pulverized raw material sucked and introduced into the accelerating pipe 82 is pulverized raw material supply port 85. Immediately after passing through, the high-pressure gas jetted by the high-pressure gas supply nozzle 81 disperses in the high-pressure gas stream while rapidly changing the flow path toward the accelerating pipe outlet 83, and is rapidly accelerated. In this state, relatively fine particles of the pulverized raw material pass through the high flow portion of the acceleration tube 82, so that the pulverized raw material is not sufficiently uniformly dispersed in the high-pressure air stream. Therefore, the pulverized raw material exits the accelerating tube 82 while being separated into a high pulverized raw material concentration flow and a low pulverized raw material flow, and the pulverized raw material collides with the opposing collision member 84 partially concentrating. ,
There is a problem of causing a decrease in processing capacity.

Further, in the above-mentioned conventional example, the crushed material crushed by the collision against the collision surface 88 of the collision member 84 collides against the inner wall of the crushing chamber 86 secondary (or tertiary) and is further finely pulverized. Since the crushing chamber 86 is box-shaped, there is a drawback that an efficient secondary collision is not performed and the fine crushing processing capability cannot be improved. Further, as shown in FIG. 8, the collision surface 88 of the collision member 84 in the conventional crusher is vertical to the direction of the particle-mixed air stream on which the crushing raw material is placed, that is, the axial direction of the acceleration tube 82. , This had the following drawbacks. That is,
When the collision surface 88 that is perpendicular to the axial direction of the acceleration tube 82 is provided, the pulverized raw material blown out from the outlet 83 of the acceleration tube 82 and the pulverized material reflected by the collision surface 88 form the collision surface 88. Since the ratio of coexistence in the vicinity increases and the concentration of the powder (grinding raw material and pulverized material) in the vicinity of the collision surface 88 increases, there is a problem that the pulverization efficiency deteriorates.

Various classifiers have been proposed as airflow classifiers to be connected to the collision type airflow crusher as described above, but a typical one is a dispersion separator (Japan) as shown in FIG. Pneumatic Industrial Co., Ltd.) is generally used. As an outline thereof, the pulverized material introduced from the pulverized material supply cylinder 91 together with the carrier air is introduced into a classification chamber 93 in which a sloping classification plate 94 having a high central portion is provided at the bottom, and the classification chamber 93 is provided. In 93, the pulverized product is swirled by the air flow introduced together with the pulverized product, and is centrifugally separated into fine powder and coarse powder through the classification louver 92,
The fine powder is discharged from a fine powder discharge chute 95 provided in the central portion of the classification plate 94, and the coarse powder is discharged from a coarse powder discharge port 96 provided on the outer peripheral portion of the classification plate 94.

However, such a conventional airflow classifier has the following problems. That is, as shown in FIG.
The pulverized material supply section to the classification chamber 93 of this type of airflow classifier is
It has a cyclone shape, and a guide tube 98 is provided upright at the center of the upper surface of the upper cover 97.
A supply cylinder 91 is connected to the outer peripheral surface of the upper part of the supply cylinder 91, and the crushed material supplied through the supply cylinder 91 is introduced in the tangential direction of the inner circumference of the guide cylinder 98. It is connected to come. Therefore, when the crushed material is supplied from the supply cylinder 91 into the guide cylinder 98, the crushed material falls while rotating along the inner peripheral surface of the guide cylinder 98. In this case, the pulverized material drops in a strip shape from the supply cylinder 91 along the inner peripheral surface of the guide cylinder 98, so that the distribution and concentration of the pulverized material flowing into the classification chamber 93 become uneven (guide to the classification chamber 93). The crushed material flows in only from a part of the inner peripheral surface of the cylinder 98), and there is a problem that the crushed material is poorly dispersed.

Further, when the treatment amount is large, agglomeration of the pulverized material is more likely to occur, and the dispersion is not sufficiently performed, so that there is a problem that highly accurate classification cannot be performed. Furthermore,
If there is a large amount of air to convey the crushed material, the classification chamber 93
Since the amount of air flowing into the chamber also increases, there is a problem that the velocity of the particles swirling in the classifying chamber 93 toward the center increases and the diameter of the separated particles increases. Therefore, as a method for reducing the size of the separated particles, air is extracted by controlling a damper with a cylinder 99 provided above the guide cylinder 98. In some cases, there is a problem in practical use that the pulverized material is lost as well. Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, to be provided with a high-precision airflow classifier section, and to be provided with a collision type airflow crusher section capable of efficiently crushing crushed raw materials. It is to provide a new fine crushing device.

[0008]

The above objects can be achieved by the present invention described below. That is, the present invention, the pulverized material introduced from the powder supply cylinder together with the carrier air, a classifier unit for separating fine powder and coarse powder, and an acceleration tube for accelerating the crushed raw material by high-pressure gas. A collision type air flow crushing having a crushing chamber provided with a collision member for crushing the powder ejected from the accelerating tube by a collision force, the collision member being provided in the crushing chamber facing the accelerating tube outlet. In a fine pulverizer equipped with a machine part, fine powder is divided and collected by the Coanda effect by pressure introduction or suction introduction of the powder from an accelerating pipe supplying the pulverization raw material, and coarse powder is pulverized by a collision member. It is a characteristic pulverizing device.

[0009]

The fine pulverizer of the present invention comprises a classifier section and a collision type air flow pulverizer section, and the discharge port of the coarse powder separated by the classifier section has a collision type air flow pulverizer section excellent in pulverization efficiency. It is connected to the crushing raw material supply port, and the crushing chamber of the collision type airflow crusher unit can be separated into fine powder and coarse powder, and the discharge port of the coarse powder supplies crushed material of the classifier unit. Since it is connected to the cylinder, it is possible to pulverize the pulverization raw material very efficiently and highly accurately as compared with the conventional fine pulverization device.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the accompanying drawings. FIG. 1 is a schematic cross-sectional view showing an embodiment of the fine crushing device of the present invention, FIG. 2 is a schematic cross-sectional view showing an embodiment of the collision type airflow pulverizer part of the present invention, and FIG. ,
4 is an enlarged view of the crushing chamber, FIG. 4 is a sectional view taken along the line AA ′ of FIG. 2, FIG. 5 is an enlarged sectional view taken along the line BB ′ of FIG. 2, and FIG. 2 is a sectional view taken along the line CC ′ of FIG. 2, and FIG. 7 is a sectional view taken along the line DD ′ of FIG. 2.

The fine crushing apparatus of the present invention is characterized by comprising a classifier section described below and a collision type air flow crusher section having a specific structure. First, the collision type airflow crusher section of the fine crushing apparatus of the present invention will be described with reference to FIG. As shown in FIG. 1, the collision type air flow crusher section of the device of the present invention has a crushing raw material supply port 1, a high pressure gas storage tank 2, an acceleration tube 3, a collision member 4, a crushing chamber 5, a classification edge 6, a fine powder discharge port 7, It is composed of a crushed material discharge port 8. Explaining the action of the high pressure gas in the collision type air flow pulverizer section, the high pressure gas first enters through the high pressure gas inlets 9 on the left and right sides of the high pressure gas storage tank 2, and after the pulsation such as pressure fluctuation is made uniform, the high pressure gas is pulverized. An air nozzle 10 provided at the center of the raw material supply port 1 flows into the acceleration pipe 3 (shown in FIG. 2). Since the accelerating tube 3 also has a divergent shape like the air nozzle 10, the high-pressure gas flowing into the accelerating tube 3 is accelerated to the supersonic region while expanding. In the process, the high pressure gas is decompressed, and the pressure of the gas at the exit of the accelerating tube 3 becomes substantially the same as the pressure in the crushing chamber 5.

Further, a classification edge 6 is provided between the accelerating pipe 3 and the collision member 4 in the crushing chamber 5 so that a relatively weak air flow on the side wall of the accelerating pipe 3 and a strong air flow at the center of the accelerating pipe 3 can be separated. . On the other hand, in the circular or elliptical crushing chamber 5, as shown in FIG.
As is clear from the sectional view taken along the line CC ′ of FIG. 2, when the gas in the crushing chamber 5 is sucked at the outlet portion 8, a suction flow is generated inside the crushing chamber 5. Then, due to the action of this suction flow, the surface of the collision member 4 is in a reduced pressure state. Then, due to the depressurizing action of the surface of the collision member 4 as described above, the jet flow emitted from the acceleration tube 3 is further accelerated and collides with the surface of the collision member 4. At this time, since the collision surface of the collision member 4 has a cone shape with an apex angle shown by θ in FIG. 3 in the range of 110 to 175 degrees, the jet flow colliding with the collision member 4 has a conical shape. Centered on the apex of the, the particles are radially diffused between the collision member 4 and the crushing chamber 5 wall. The diffused air flow is carried on the suction flow inside the crushing chamber 5 described above, and is formed in the exit portion 8 of the crushing chamber 5.
Be led to.

Next, the action of the crushed raw material supplied in the collision type air flow crusher section will be described. The pulverized raw material that is the object to be pulverized is supplied from above the pulverized raw material supply port 1. Then, the pulverized raw material supplied is the powder raw material supply port 1
It is sucked and discharged from the lower part of the to the acceleration tube 3. The principle of suction and discharge of the raw material at this time is based on the ejector effect by the expansion and decompression of the high-pressure gas in the accelerating tube. At this time, in the collision-type airflow crusher section of the collision-type airflow crusher of the present invention, in order to sufficiently disperse the pulverized raw material and suck it into the acceleration tube 3, the throat portion and the acceleration tube 3 of the acceleration tube 3 are drawn. 3 between the outlets of the crushing material 3 and the crushing raw material supply port 1 extending in the entire circumferential direction of the accelerating tube 3 as shown in FIG. Since the pulverized raw material supply port 1 composed of n ≧ 2) holes is provided (n = 4 in FIG. 5B), the pulverized raw material is sufficiently dispersed and accelerated by the high-pressure air stream. In contrast,
In the conventional collision type air flow crusher as shown in FIG. 8, the raw material supply port 85 to the accelerating pipe 82 is connected to the middle of the accelerating pipe 82 and is provided at only one place. The pulverized raw material introduced by suction is immediately after passing through the raw material supply port 85,
By the high-pressure airflow ejected from the high-pressure gas supply nozzle 81, the flow path is rapidly changed in the direction of the accelerating pipe outlet 83, while being dispersed in the high-pressure airflow and being rapidly accelerated,
The pulverized raw material was separated into a high-concentration flow and a low-concentration flow, and was sufficiently dispersed and not accelerated.

As shown in FIG. 1 or 2, the acceleration tube 3
The pulverized raw material that is dispersed and sucked inside is the raw material supply port 1
Is completely dispersed by the high-speed airflow radiated from the air nozzle 10 provided in the central part of the. Next, the pulverized raw material dispersed as described above is accelerated by riding on the high-speed air current flowing inside the accelerating tube 3, and becomes a supersonic solid-gas mixture flow. In this solid-gas mixture flow, the jet in the acceleration tube interferes with the side wall of the acceleration tube to reduce the pressure on the wall side, and the Coanda effect, which is a function of adhering to the wall and flowing, causes relatively fine powder to flow on the wall side and relatively coarse powder. Flows near the center. Utilizing such a phenomenon, the crushing raw material of the solid-gas mixture flow is separated into fine powder and coarse powder by the classification edge 6 near the outlet of the acceleration tube, and the fine powder is discharged through the fine powder discharge port 7.

Further, the coarse powder is subjected to the same action as the jet flow described above and collides with the collision member 4. The raw material coarse powder is finely pulverized by this collision. The pulverized material is then further pulverized by secondary collision on the wall of the pulverization chamber 5, and in some cases, the pulverized material is conveyed to the outlet section 8 of the pulverization chamber 5,
A tertiary (and quaternary) collision occurs between the wall of the crushing chamber 5 and the side surface of the collision member 4, and further crushing is performed. Particularly, in the collision type airflow crusher section of the device of the present invention, since the crushing chamber 5 has a circular or elliptical cross-sectional shape, the crushed material dispersed from the collision surface in substantially the entire circumferential direction is crushed. A secondary collision efficiently occurs with the wall of the chamber 5, and the crushing efficiency is further improved.

Further, the tip end portion of the collision surface of the collision member 4 of the collision type airflow crusher section of the device of the present invention has a cone shape having an apex angle in the range of 110 to 175 degrees as shown by θ in FIG. Because there is
For example, even when the powder raw material is a powder containing a resin or an adhesive material, problems such as fusion, agglomerates and coarse particles do not occur. Further, the collision type airflow pulverizer section of the device of the present invention can uniformly disperse the pulverized raw material in the high-speed airflow, and therefore, even when pulverizing the pulverized raw material containing the abrasive material, the inner wall of the acceleration tube 3 or The occurrence of local wear on the collision surface of the collision member 4 can be prevented, and more stable operation can be performed. Furthermore, in the crushing chamber 5, the classification edge 6
Since fine powder and coarse powder can be separated, it is possible to prevent the generation of fine particles due to over-pulverization, and it is possible to adjust the particle size to a predetermined size without causing fusion or aggregation.

Examples of the classifier used in the present invention include a DS type classifier manufactured by Nippon Pneumatic Mfg. Co., Ltd. and a micron separator manufactured by Hosokawa Micron. It is preferable to use the airflow classifier shown in FIG. 1 in order to improve the classification accuracy of fine powder and coarse powder. Next, the airflow classifier section which is another component will be described with reference to FIG.
In FIG. 1, 11 is a cylindrical main body casing, 12 is a lower casing, and a hopper 13 for discharging coarse powder is connected to the lower portion of 12. A classification chamber 14 is provided inside the main body casing 11.

The upper portion of the classifying chamber 14 is closed by an annular guide chamber 15 attached to the upper portion of the main body casing 11 and a conical (umbrella) upper cover 16 having a raised central portion. . A plurality of louvers 18 arranged in the circumferential direction is provided on a partition wall between the classification chamber 14 and the guide chamber 15, and the crushed material and the air sent from the supply cylinder 17 are fed into the guide chamber 15. The louvers 18 are swirled into the classification chamber 14 so as to flow into the classification chamber 14. Information room 1
The louver 18 and the air flowing in 5 are crushed.
It is necessary to distribute them evenly in order to accurately classify. Further, the flow path to reach the louver 18 needs to be shaped so that concentration due to centrifugal force does not easily occur. In the example of FIG. 1, the supply cylinder 17 is connected in the upward direction perpendicular to the horizontal plane of the classification chamber 14, but the invention is not limited to this.

In this way, in the airflow classifier section used in the apparatus of the present invention, since air and pulverized material are supplied to the classification chamber 14 via the louver 18, air is supplied when the air is supplied to the classification chamber 14. A significant improvement in dispersion is achieved with the milled material compared to conventional methods. The louver spacing can be adjusted arbitrarily.
Further, in the air flow classifier section used in the device of the present invention, the classification louvers 1 arranged in the lower part of the main body casing 11 in the circumferential direction as well.
9 is provided, and classification air for generating a swirling flow from the outside to the classification chamber 14 is taken in through the classification louver 19.

At the bottom of the classifying chamber 14, a conical (umbrella) classifying plate 20 having a raised central portion is provided, and a coarse powder discharge port 21 is formed on the outer periphery of the classifying plate 20. Further, a fine powder discharge chute 22 connected to a fine powder discharge port is provided at the center of the classifying plate 20.
Is provided, the lower end of the fine powder discharge chute 22 is bent into an L shape, and the bent end is located outside the side wall of the lower casing 12. Furthermore, fine powder discharge chute 2
Reference numeral 2 is connected to a suction fan (not shown) via a fine powder collecting means such as a cyclone or a dust collector, and the suction force is applied to the classification chamber 14 by the suction fan, so that the classification louver 19 is provided with a classification chamber. The swirling flow required for classification is caused by the suction air flowing into 14.

The air flow classifier section used in the apparatus of the present invention is
Due to the above-mentioned structure, when the pulverized material is supplied from the supply cylinder 17 to the guide chamber 15 together with the air, the air containing the pulverized material passes from the guide chamber 15 between the louvers 18 and is classified. It is flowed into the chamber 14 while being swirled while being dispersed with a uniform concentration. The pulverized material that has flowed into the classification chamber 14 while swirling is then converted into a suction air flow that is generated by a suction fan connected to the fine powder discharge chute 22 and that flows between the classification louvers 19 at the bottom of the classification chamber 14. Riding is further increased, and the centrifugal force that acts on each particle efficiently separates into coarse powder and fine powder. At this time, the classification room 14
The coarse powder swirling around the inner peripheral portion is discharged from the coarse powder discharge port 21 and then discharged from the lower hopper 13. Further, the fine powder that moves to the central portion along the upper inclined surface of the classification plate 20 is collected from the fine powder discharge chute 22 (23, 2).
It is discharged to 4).

In the air stream classifier section used in the apparatus of the present invention, all the air that flows into the classifying chamber 14 together with the pulverized material flows in a swirling flow, so that the air flowing in the classifying chamber 14 is directed toward the center of the particles. The speed becomes relatively smaller than the centrifugal force, and the separation particle size is small in the classifying chamber 14, and the fine powder having a very small particle size is discharged into the fine powder chute 2.
2 can be discharged. Moreover, since the pulverized material flows into the classification chamber 14 at a substantially uniform concentration, it is possible to obtain a fine powder having a fine distribution.

The fine crushing apparatus of the present invention comprises a collision type air flow crusher section and a classifier section as described above, which are connected as shown in FIG. That is, the coarse powder discharge port 21 of the classifier unit is connected to the crushed object supply port 1 of the collision type airflow crusher unit, and the crushed product discharge port 8 of the collision type airflow crusher unit is crushed by the airflow classifier unit. By connecting to the substance supply cylinder 17, the pulverized product efficiently pulverized by the collision type airflow pulverizer section is introduced into the airstream classifier section, and only fine powder having a very small particle size and a fine distribution is obtained. Recovered from the discharge chute 22,
The other coarse powders are reintroduced into the collision type airflow pulverizer section and pulverized again, and the pulverization is repeated until a fine powder having a very small particle size and a fine distribution is obtained.

The fine powder classified by the classifying edge 6 in the crushing chamber 5 is a fine powder discharge chute 2 through a route not shown.
It may be connected to No. 2 and collected at the same time as the pulverized fine powder from the fine powder discharge chute 22, or may be independently collected by the fine powder collecting means 23 'and 24'. In the collision-type airflow crushing apparatus of the present invention, the crushed raw material is introduced from the raw material introduction port 1 or 25 of FIG. 1 by an appropriate introduction means.

[0025]

As described above, in the collision type air flow crusher section of the fine crushing apparatus of the present invention, the material to be crushed is stronger because the raw material supply method to the accelerating tube is devised compared to the conventional one. It is dispersed, accelerated and introduced into the grinding chamber. Furthermore, since the back pressure in the crushing chamber is low, it is possible to cause the crushed object to collide with the collision member more quickly. Moreover, since fine powder and coarse powder can be separated in the crushing chamber, it is possible to prevent excessive crushing, and it is possible to crush to a predetermined fine particle size. As a result, it becomes possible to improve the pulverization efficiency.

Further, the collision type airflow crusher section of the collision type airflow crushing device of the present invention has a structure of the crushing chamber and a reduction in dust concentration due to strong dispersion of the material to be crushed. Fusing and wear of the chamber to be crushed are also greatly reduced compared to the conventional collision type air flow crusher, and stable operation can be achieved. Further, in the airflow classifier section of the collision type airflow pulverizing apparatus of the present invention, classification with a small separation particle size is performed in the classification chamber, and it is possible to obtain a fine powder having a very small particle size and a fine distribution. Therefore, the collision type airflow pulverizing apparatus of the present invention can efficiently pulverize the pulverizing raw material and can also accurately collect the pulverized fine powder.

[0027]

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a pulverizing apparatus of the present invention.

FIG. 2 is a schematic sectional view of a collision type crusher of the present invention.

FIG. 3 is an enlarged view of the crushing chamber in FIG.

4 is a cross-sectional view taken along the line AA ′ in FIG.

5 is an enlarged cross-sectional view (a) taken along line BB ′ in FIG. 2 and a modification (b) thereof.

6 is a sectional view taken along line CC ′ in FIG.

FIG. 7 is a sectional view taken along the line DD ′ in FIG.

FIG. 8 is a schematic cross-sectional view of a conventional collision type airflow crusher.

FIG. 9 is a schematic cross-sectional view of a conventional airflow classifier.

[0028]

[Explanation of symbols]

 1: Grinding raw material supply port 2: High pressure gas storage tank 3: Accelerator tube 4: Collision member 5: Grinding chamber 6: Classification edge 7: Fine powder discharge port 8: Ground material discharge port 9: High pressure gas inlet 10: Air nozzle 11: Classifier body casing 12: Lower classifier casing

13: Coarse powder discharge hopper 14: Classification chamber 15: Guide chamber 16: Upper cover 17: Supply cylinder 18: Louver 19: Classification louver 20: Classification plate 21: Coarse powder discharge port 22: Fine powder discharge chute 23, 23 ′: Fine powder collecting means 24, 24 ′: Fine powder collecting means 25: Ground material introduction port

Claims (1)

[Claims] 1. A classifier section in which a pulverized product introduced from a powder supply cylinder together with carrier air is separated into fine powder and coarse powder,
An accelerating tube for accelerating the crushed raw material by high pressure gas,
A collision-type airflow crusher having a crushing chamber equipped with a collision member for crushing the powder ejected from the accelerating tube by a collision force, the collision member being provided in the crushing chamber facing the accelerating tube outlet. In a fine pulverizing device equipped with a part, fine powder is divided and collected by a Coanda effect by introducing pressure or suction from an accelerating pipe supplying a pulverizing raw material, and coarse powder is pulverized by a collision member. Fine crushing equipment.