JP2663046B2 - Collision type air flow crusher and crushing method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impingement airflow pulverizer and a pulverization method using a giotto airflow (high-pressure gas), and more particularly, to a toner used in an image forming method by electrophotography. Also, the present invention relates to an impingement airflow pulverizer and a pulverization method for efficiently producing a colored resin powder for toner.

[Related Art] A collision-type airflow pulverizer using a jet airflow conveys a powdery raw material by a jet airflow, collides the powdery raw material with a collision member, and pulverizes the powdery raw material by the impact force.

The details will be described below with reference to FIGS. 8 and 9.

A collision member 6 is provided to face the outlet 4 of the acceleration tube 12 to which the compressed gas supply nozzle 3 is connected, and the high-pressure gas supplied to the acceleration tube 12 is supplied to supply the powder raw material that is communicated to the middle of the acceleration tube 12. The powder raw material 15 is sucked from the port 1 into the accelerating tube 12 and injected with the high-pressure gas to collide with the collision surface of the collision member 6 and to be pulverized by the impact. When the powder raw material 15 is used for pulverizing the powder raw material 15 to a desired particle size, the powder raw material supply port 1 and the discharge port 9 are used.
A classifier is placed in between to make a closed circuit.
And the coarse powder is supplied from the powder material supply port 1 to be pulverized, and the pulverized material is returned to the classifier through the discharge port 9 to be classified again. Of fine particles.

However, in the above-described conventional example, it is difficult to sufficiently disperse the powder raw material 15 sucked and introduced into the acceleration tube 12 in a high-pressure airflow. It separates into a thick stream and a pale stream.

Therefore, the powder flow hitting the opposing collision surface 17 becomes partial (local), the efficiency is reduced, and the processing capacity is reduced. Further, if the processing capacity is to be increased in such a state, the dust concentration is further increased partially, so that the efficiency is further reduced.
A fused material is generated on the surface, which is not preferable.

In addition, when the powder raw material 15 containing a large amount of coarse particles is sucked and introduced into the acceleration tube 12, the suction capacity of the powder raw material supply port 1 is reduced, and as a result, the processing capacity is reduced.

In order to increase the efficiency of crushing particles inside the acceleration tube 12,
Japanese Patent Publication No. 46-22778 proposes a pulverizing pipe provided with a high-pressure gas supply pipe for ejecting a secondary high-pressure gas before the acceleration pipe outlet 4. This is intended to promote collision inside the accelerating tube 12 and is a useful means for a pulverizer that performs pulverization only inside the accelerating tube 12. It is not a useful method in the impingement type air current pulverizer. This is because, if a secondary high-pressure gas is introduced to promote collision in the acceleration tube 12, the carrier airflow due to the high-pressure gas introduced from the compressed gas supply nozzle 3 is obstructed, and the powder flow ejected from the acceleration tube outlet 4 is disturbed. Speed is reduced. Therefore, the impact force colliding with the collision member 6 decreases,
The pulverization efficiency is undesirably reduced.

On the other hand, as shown in FIGS. 8 and 9, the collision surface of the collision member in such a conventional crusher is perpendicular or inclined (for example, 45 degrees) with respect to the direction of the high-pressure airflow (axial direction of the acceleration tube) on which the object to be crushed is placed. Ii) A flat plate has been used (see JP-A-57-50554 and JP-A-58-148453).

However, in the case of the collision surface 17 perpendicular to the axial direction of the acceleration tube 12 as shown in FIG. 8, the crushed material blown out from the acceleration tube outlet 4 and the crushed material reflected on the collision surface are close to the collision surface. The coexistence ratio is high, so that the concentration of the powder (the material to be crushed and the crushed material) near the collision surface becomes high, and the crushing efficiency is not good.

Furthermore, temporary collision at the collision surface is mainly performed, and it cannot be said that the secondary collision with the crushing chamber wall 8 is effectively used.
Furthermore, when pulverizing a thermoplastic resin, fusion and agglomerates are liable to be generated due to local heat generation at the time of collision, which makes stable operation of the apparatus difficult and causes reduction in pulverization ability. For this reason, it has been difficult to use the material to be crushed with a high concentration.

Further, in the crusher shown in FIG.
Although the powder concentration near the collision surface is lower than that of the pulverizer in FIG. 8 due to the inclination with respect to the axial direction 12, the collision force due to the high-pressure air flow is dispersed and lowers. Furthermore, it cannot be said that the secondary collision with the crushing chamber wall 8 is effectively used. For example, as shown in FIG. 9, when the collision surface has an angle of 45 ° with respect to the accelerating tube, the above-mentioned problems are small when pulverizing the thermoplastic resin. However, since the impact force used for the crushing at the time of collision is small and the crushing due to the secondary collision with the crushing chamber wall 8 is small, the crushing ability is
The crushing ability is reduced to 1/2 to 1 / 1.5 as compared with the crusher shown in FIG.

Therefore, a pulverizer and a pulverization method with good pulverization efficiency are expected.

On the other hand, a toner or a colored resin powder for a toner used in an image forming method by an electrophotographic method usually contains at least a binder resin and a colorant or a magnetic powder. The toner develops the electrostatic charge image formed on the latent image carrier, and the formed toner image is transferred to a transfer material such as plain paper or a plastic film, and is heated and fixed, a pressure roller is fixed, or a heat and pressure roller is used. The toner image on the transfer material is fixed to the transfer material by a fixing device such as a fixing unit. Therefore, the binder resin used for the toner has a property of being plastically deformed when heat and / or pressure is applied.

At present, the toner or the colored resin powder for the toner is prepared by melt-kneading a mixture containing at least a binder resin and a colorant or a magnetic powder (containing a third component, if necessary),
It is prepared by cooling the melt-kneaded product, pulverizing the cooled product, and classifying the pulverized product. Generally, the crushing of the cooled material is roughly crushed (or medium crushed) by a mechanical impact crusher, and then the coarsely crushed powder is finely crushed by an impinging airflow crusher using a jet stream. is there.

In such a case, in the conventional impingement airflow pulverizer and the pulverization method as shown in FIG. 9, if the processing capacity is to be further improved, the powder raw material supply port 1 provided in the acceleration tube 12 will have insufficient suction. Alternatively, a fusion product is generated on the collision surface 27, and stable production cannot be performed. Therefore, in order to more efficiently generate a toner or a colored resin powder for toner used in an image forming method by electrophotography, the above-described problems have been solved.
There is a need for an efficient impingement airflow pulverizer and pulverization method.

[Problems to be Solved by the Invention] In view of the above conventional problems, an object of the present invention is to efficiently pulverize an object to be crushed mainly composed of a thermoplastic resin such as a polyester resin or a styrene resin. An object of the present invention is to provide an impingement type air current pulverizer and a pulverization method for pulverization.

Further, the fusion of the crushed object and the crushed powder in the crushing chamber hardly occurs, and even when the processing amount of the crushed object is increased, the fusion of the crushed object and the crushed powder is suppressed,
An object of the present invention is to provide an impingement airflow pulverizer and a pulverization method with less generation of agglomerates and coarse particles, and in particular, an average particle diameter of 20 to 20.
An object of the present invention is to provide an impinging airflow pulverizer and a pulverization method capable of efficiently pulverizing resin particles having a size of 00 μm to an average particle size of 3 to 15 μm.

It is still another object of the present invention to provide a collision-type airflow pulverizer and a pulverization method capable of efficiently producing toner or toner colored resin particles used in a copying machine and a printer having a heating / pressing roller fixing unit.

[Means and Actions for Solving the Problems] According to the present invention, the powder raw material 15 ejected from the accelerating pipe 2 is caused to collide with the powder raw material 15 ejected from the accelerating pipe 2 downstream of the accelerating pipe 2 for transporting and accelerating the powder raw material 15 by high pressure gas. In a collision type air current pulverizer provided with a pulverizing chamber 5 in which a collision member 6 for pulverization is arranged opposite to an acceleration tube outlet 4, a plurality of powder material supply ports are provided in the acceleration tube 2. Providing a secondary air inlet between the supply port and the outlet of the accelerating tube, and as a collision-type airflow pulverizer having a cone shape with a vertex angle of 110 ° or more and less than 180 ° at the tip of the collision surface of the collision member There is in the point.

Also, a pulverizing method in which the powder raw material 15 is conveyed and accelerated by a high-pressure gas in the accelerating tube 2, discharged from the accelerating tube outlet 4 into the pulverizing chamber, and collided with the opposing collision member 6 to pulverize the powder raw material 15 into fine particles. In the above, the powder raw material is guided to the upstream of the accelerating tube 2 from the plurality of powder raw material supply ports, secondary air is introduced between the plurality of powder raw material supply ports and the acceleration pipe outlet, and The tip is apex 110
The pulverizing method is also characterized in that the powder raw material 15 is crushed by colliding with the colliding member 6 having a cone shape of not less than 180 ° and the crushed material is further subjected to secondary collision with the wall of the crushing chamber to be crushed. Is what you do.

According to the collision type airflow pulverizer of the present invention having the above-described configuration, the object to be pulverized can be efficiently pulverized to the order of several μm by utilizing the high-speed airflow. In particular, the object to be ground by the thermoplastic resin or the object to be ground mainly comprising the thermoplastic resin can be efficiently ground to the order of several μm.

Further, the present invention will be described in detail with reference to the accompanying drawings. First
FIG. 1 is a schematic cross-sectional view of an impinging airflow pulverizer of the present invention and an example of a flowchart of a pulverizing method in which a pulverizing step using the pulverizer and a classification step using a classifier are combined. The powder raw material 15 to be pulverized is obtained by dispersing the powder raw material from a plurality of powder raw material supply ports 1 provided upstream of the acceleration tube 2 shown in FIG. It is supplied to the acceleration tube 2. A compressed gas such as compressed air is introduced into the acceleration tube 2 from a compressed gas supply nozzle 3, and the powder material 15 supplied to the acceleration tube 2 is instantaneously accelerated to have a high speed. The powdery raw material 15 discharged from the acceleration pipe outlet 4 into the pulverizing chamber 5 at a high speed collides with the collision surface 7 of the collision member 6 and is pulverized. Further, in such a crusher, a secondary air inlet 11 is provided between the powder material supply port 1 of the acceleration tube 2 and the acceleration tube outlet 4, and the secondary air is introduced into the acceleration tube so that the powder material is removed. Improving the suction capability of the supply port 1 to disperse the crushed object in the acceleration tube, more uniformly eject the crushed object from the acceleration tube outlet 4, and efficiently collide with the collision surface 7 of the opposing collision member 6. Thereby, the pulverizability can be improved more than before. Here, the introduced secondary air contributes to break up and disperse the coagulation of the object to be crushed moving at high speed in the acceleration tube. In addition, there is an effect of accelerating the flow along the inner wall of the acceleration tube, which is a portion where the acceleration gas flow velocity distribution is slow in the acceleration tube.

FIG. 3 shows a cross-sectional view of a main part of the acceleration tube, which will be described in more detail. As a result of intensive studies on the method of introducing the introduced secondary air, the following conclusions were reached. That is, as for the position where the secondary air is introduced, in FIG. 3, the distance between the crushed material supply port 1 and the acceleration pipe outlet 4 is X, and the distance between the crushed material supply port 1 and the secondary air introduction port 11 is Y. Then,
Good results were obtained when X and Y satisfied 0.2 ≦ Y / X ≦ 0.9, more preferably 0.3 ≦ Y / X ≦ 0.8. Regarding the introduction angle of the secondary air inlet 11, assuming that the angle with respect to the axial direction of the acceleration tube in FIG. 3 is Ψ, 10Ψ ≦ ゜ ≦ 80 ゜, more preferably, 20 ゜ ≦ Ψ ≦ 80. When the conditions of ゜ were satisfied, good pulverization results were obtained. Regarding the flow rate of the introduced secondary air, the flow rate of the carrier gas by the high-pressure gas introduced from the compressed gas supply nozzle 3 is aN
m ³ / min, when the total air volume of the secondary air introduced from the secondary air inlet 11 is bNm ³ / min, a, b is more preferably 0.001 ≦ b / a ≦ 0.5, more preferably 0.01 ≦ b / a Good results were obtained when pulverization was performed under conditions satisfying ≦ 0.4. As the secondary air, either a compressed gas or a normal pressure gas may be used. It is very preferable to provide an air flow control device such as a valve at the secondary air inlet to adjust the air flow. The position in the circumferential direction of the accelerating tube at which the introduction port is provided may be appropriately set according to the raw material to be pulverized, the target particle diameter to be pulverized, and the like. FIG. 4 is a sectional view taken along the line BB in FIG. 3 in a case where eight secondary air inlets are provided in the circumferential direction of the accelerating tube as one embodiment.

In this case, the distribution of the secondary air to be introduced from eight locations is appropriately set. Further, the cross section of the acceleration tube is not limited to a perfect circle.

On the other hand, in the pulverizer shown in FIG.
Since it has a conical shape having an angle of not less than ゜ and less than 180 °, preferably about 160 °, the crushed material is dispersed substantially in the entire circumferential direction, causing secondary collision with the crushing chamber wall 8, Crushed. FIG. 2 is a view schematically showing a cross section taken along the line AA of the impingement type air current pulverizer shown in FIG. Is shown. From FIGS. 1 and 2, it can be seen that according to the impingement type air current pulverizer of the present invention, the secondary collision of the pulverized material on the pulverization chamber wall 8 is effectively utilized. Further, in the pulverizer of the present invention, as shown in FIG.
Is widely used in the secondary collision, the concentration of the (crushed) material in the vicinity of the collision surface 7 does not increase, so that the processing efficiency of the grinding can be improved, It is possible to favorably suppress fusion.

The pulverized material introduced into the pulverizing chamber 5 is pulverized by primary collision at the collision surface 7, and then pulverized by secondary collision at the pulverizing chamber wall 8. Before being transported to the discharge port 9, it is further crushed by tertiary (and quaternary) collision with the crushing chamber wall 8 and the side surface of the collision member 6. The pulverized material discharged from the discharge port 9 is classified into fine powder and coarse powder by a classifier such as a fixed wall type air classifier. The classified fine powder is taken out as a crushed product. The classified coarse powder is supplied to the powder material supply port 1 together with a newly-input crushed material.

6 and 7 are cross-sectional views in which two and four powder material supply ports are provided in the acceleration tube 2 (see CC in FIG. 1).
Part cross section) is shown. The cross section of the acceleration tube 2 is not limited to a circular shape.

On the other hand, the inner diameter of the acceleration tube outlet 4 usually has a diameter of 10 to 100 mm, and preferably has an inner diameter smaller than the diameter of the collision member 6.

The distance between the acceleration tube outlet 4 and the tip of the collision member 6 is preferably 0.3 to 3 times the diameter of the collision member 6. If it is less than 0.3 times, over-pulverization tends to occur, and if it exceeds 3 times,
The grinding efficiency tends to decrease.

The crushing chamber 5 of the impinging airflow crusher in the present invention is not limited to the box type shown in FIG.

The technical idea of the present invention is that the powder raw material 15 is injected into a carrier gas flow by the high-pressure gas introduced from the compressed gas supply nozzle 3, ejected from the acceleration tube outlet 4, and
In the collision-type air current pulverizer which crushes the powder material 15 by colliding the powder material 15 with the collision surface 7, the dispersion state of the powder material 15 in the acceleration tube 2 and the supply of the powder material under the powder material supply hopper tube 16 Mouth 1
Is based on the idea that the suction force may affect the crushing efficiency. That is, since the powder raw material 15 supplied from the accelerating tube 2 flows into the accelerating tube 2 in an agglomerated state, the dispersion in the accelerating tube 2 becomes insufficient. And the collision surface 7 cannot be used effectively. Further, in the case of coarse particles, the suction force of the powder material supply port 1 decreases, and the powder material 15
It was considered that the supply of the powder was insufficient and the grinding efficiency was reduced. This phenomenon becomes more conspicuous as the amount of pulverization increases.

Either a highly compressed gas or a normal pressure gas may be used as the secondary air. It is very preferable that an opening / closing device such as a valve is attached to each secondary air inlet 11 to control the amount of introduced air. The number of the secondary air inlets 11 to be attached at which position in the upper direction of the acceleration tube 2 may be appropriately set according to the powder raw material 15, the target particle diameter, and the like. FIG. 4 is a sectional view taken along line BB when eight secondary air inlets 11 are attached in the circumferential direction of the acceleration tube 2 as an example. In this case, what distribution of the secondary air is introduced from the eight locations may be set as appropriate.

As described above, according to the apparatus and method of the present invention, the powder material 15 is supplied from the plurality of powder material supply ports 1 to the acceleration tube 2.
The secondary air can be dispersed and supplied into the
In this way, the suction ability of the powder raw material 15 from the powder raw material supply port 1 is improved, the dispersion of the powder raw material 15 in the acceleration tube 2 becomes good, and the powder raw material 15 collides with the collision surface 17 efficiently, and the pulverization efficiency is improved. Is improved. That is, the processing capacity is improved as compared with the conventional pulverizer, and the particle size of the obtained product can be made smaller with the same processing capacity.

In the conventional example, in the state where the powder raw material 15 is agglomerated,
Since the particles collide with the particles 7, 27, a fused material is liable to be generated particularly when a powder mainly composed of a thermoplastic resin is used as a raw material. On the other hand, according to the present invention, the dispersed state collides with the collision surface 7, so that it is difficult to generate a fused material.

Further, in the conventional example, since the powder raw material 15 is agglomerated, excessive pulverization is likely to occur, and therefore, there is a problem that the particle size distribution of the obtained pulverized product is wide. On the contrary,
According to the present invention, excessive pulverization can be prevented, and a pulverized product having a sharp particle size distribution can be obtained.

Further, according to the present invention, the powder raw material 15 can be dispersed and supplied from the plurality of powder raw material supply ports 1 into the acceleration tube 2, and the secondary air is efficiently introduced, so that the powder raw material 15 can be efficiently supplied. The air suction capability at the supply port 1 is improved, and
The transfer capacity in the accelerating tube 2 is improved, and the pulverization processing amount can be increased as compared with the conventional case.

The effect of the apparatus and method of the present invention becomes more remarkable as the particle diameter becomes smaller.

[Examples] Hereinafter, the present invention will be described in detail based on examples and comparative examples.

Example 1 The above raw materials were mixed with a Henschel mixer to obtain a mixture. Next, mix this mixture with an extruder for about 180
After melt-kneading at a temperature of ℃, the mixture was cooled and solidified, and a cooled material of the melt-kneaded product was roughly pulverized into particles of 100 to 1000 μm with a hammer mill to obtain powder raw material 15. Then, pulverization was carried out with a pulverizer and a flow shown in FIGS. A fixed wall type air classifier was used as a classification means for classifying the pulverized powder into fine powder and coarse powder.

Here, in the collision type air flow pulverizer, the inner diameter of the outlet 4 of the acceleration tube 2 is 25 mm, and in FIG. 3 and FIG. Was satisfied, the collision member 6 had a columnar shape made of aluminum oxide ceramic having a diameter of 60 mm, and the tip of the collision surface 7 had a conical shape having an apex angle of 160 °. The center axis of the accelerating tube 2 and the tip of the collision member 6 coincided with each other. The closest distance from the accelerator tube exit 4 to the collision surface 7 is 60
mm, and the closest distance between the collision member 6 and the crushing chamber wall 8 is 18 mm.
mm.

Compressed air having a flow rate (a) of 6.4 Nm ³ / min (pressure 6.0 kg / cm ² ) was introduced from the compressed gas supply nozzle 3 of the impingement type air flow pulverizer, and powder was supplied at a rate of 45 kg / hour from the powder material supply port 1. Body material 1
5 supplied. The crushed powder material is transported to a classifier,
The fine powder was removed as a classified powder, and the coarse powder was again fed into the acceleration tube 2 together with the powder raw material 15 from the powder raw material supply port 1. As the secondary air, compressed air of 0.1 Nm ^{3 /} min (5.0 kg / cm ² ) from each of the eight locations F, G, H, I, J, K, L and M in FIG. 4 (b) Introduced As a result, pulverized powder having a volume average particle size of 7.5 μm (measured by a Coulter counter) as fine powder was collected at a rate of 45 kg / hour. Further, even after the continuous operation for 6 hours, no fused product was generated.

The particle size distribution of the toner can be measured by various methods. In the present embodiment, the measurement was performed using a Coulter counter.

In other words, the Coulter Counter TA is used as a measuring device.
-Type II (manufactured by Coulter, Inc.) is connected to an interface (manufactured by Nikkaki) that outputs the number distribution and volume distribution, and a CX-1 personal computer (manufactured by Canon). Prepare a% NaCl aqueous solution. As a measurement method, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the aqueous electrolytic solution, and 2 to 20 mg of a measurement sample is further added. The electrolyte solution in which the sample was suspended was subjected to a dispersion treatment for about 1 to 3 minutes with an ultrasonic disperser, and the Coulter Counter TA-II was used, and a 100-μm aperture was used as an aperture. The particle size distribution was measured and then the values according to this example were determined.

Example 2 The powder raw material used in Example 1 was prepared by changing the inner diameter of the outlet 4 of the acceleration tube.
25 mm, and in FIGS. 3 and 4, 6.4 Nm ³ / min (6 kgf / cm ² ) from the compressed gas supply nozzle 3 by using a conical impingement type air pulverizer in which the collision surface of the collision member has a cone angle of 120 ° Compressed air is introduced, and the secondary air is F, G, H, I, J,
Compressed air of 0.1 Nm ³ / min (5 kgf / cm ² ) is introduced from each of the eight locations K, L, and M, and 36 kg is fed from the powder material supply port 1 shown in FIG.
Powder material 15 was supplied at a rate of / hour. The pulverized powder raw material was conveyed to a classifier, the fine powder was removed as a classified powder, and the coarse powder was again fed into the acceleration tube 2 together with the powder raw material 15 from the powder raw material supply port 1.

As a result, pulverized powder having a volume average particle size of 7.5 μm (measured by a Coulter counter) was collected as fine powder at a rate of 36 kg / hour. Further, even after the continuous operation for 6 hours, no fused product was generated.

Example 3 The powder raw material used in Example 1 was prepared by changing the inner diameter of the outlet 4 of the acceleration tube.
25 mm, and in FIGS. 3 and 4, 6.4 Nm ³ / min (6 kgf / cm ² ) from the compressed gas supply nozzle 3 by using a conical impingement type air pulverizer in which the collision surface of the collision member has a cone angle of 120 ° Compressed air is introduced, and the secondary air is F, G, H, I, J,
Compressed air of 0.1 Nm ³ / min (5 kgf / cm ² ) was introduced from each of the eight locations K, L, and M, and 39.5 g of powder air was supplied from the powder material supply port 1 shown in FIG.
Powder raw material 15 was supplied at a rate of kg / hour. The pulverized powder raw material was conveyed to a classifier, the fine powder was removed as a classified powder, and the coarse powder was again fed into the acceleration tube 2 together with the powder raw material 15 from the powder raw material supply port 1.

As a result, pulverized powder having a volume average particle size of 7.5 μm (measured by a Coulter counter) as fine powder was collected at a rate of 39.5 kg / hour. Further, even after the continuous operation for 6 hours, no fused product was generated.

Comparative Example 1 The powder raw material used in Example 1 was pulverized by a conventional impingement airflow pulverizer shown in FIG. In the crusher, the collision surface 17 at the tip of the collision member 6 is a plane perpendicular to the axial direction of the acceleration tube 12, and the inside diameter of the acceleration tube outlet 4 is 25 mm.
6.4 Nm ³ / min from the compressed gas supply nozzle 3
(6 kgf / cm ² ) of compressed gas was supplied, and pulverization was performed by setting a classifier so that the fine powder (pulverized product) had a weight average particle size of 7.5 μm. The (crushed) material colliding with the collision surface 17 is
Since the light is reflected in the direction opposite to the discharge direction from the crushed material, the concentration of the (crushed) material in the vicinity of the collision surface becomes extremely high. Therefore, if the supply rate of the raw material to be pulverized exceeds 4.5 kg / hour, fusion and agglomerates may start to occur on the collision member, and the fusion may clog the pulverizing chamber and the classifier. Therefore, it was necessary to reduce the pulverization throughput to 4.5 kg per hour, which was the limit of the pulverization ability.

In addition, when pulverization is performed to obtain fine powder (pulverized product) having a weight average particle size of 11 μm, if the supply rate of the raw material to be pulverized exceeds 9 kg / hour, fusion and agglomeration on the collision member may occur. This began to occur and this was the limit of the grinding capacity.

Comparative Example 2 The powder raw material used in Example 1 was pulverized in the same manner as in Comparative Example 1 using a collision-type air-flow pulverizer shown in FIG. The crusher was the same as the crusher used in Comparative Example 1 except that the collision surface 27 at the tip of the collision member 6 was a flat surface inclined at 45 ° with respect to the axial direction of the acceleration tube 12. Is the same.

The (crushed) material that collided with the collision surface 27 was reflected in a direction away from the acceleration tube outlet 4 as compared with Comparative Example 1, so that no fusion or agglomeration occurred. However, when colliding, the impact force is weakened, so the crushing efficiency is poor, and the weight average particle size is 7.
Only about 4.5 kg per hour of a 5 μm fine powder (ground product) was obtained.

In the case of obtaining fine powder (pulverized product) having a weight average particle size of 11 μm, only about 9 kg was obtained per hour.

 Table 1 shows the results of the above Examples and Comparative Examples.

[Effects of the Invention] As described above, according to the collision-type airflow pulverizer and the pulverization method of the present invention, fusion and agglomeration during pulverization can be prevented, and stable operation of the apparatus can be achieved. Moreover, since the pulverized material strongly collides with the pulverizing chamber wall, the conventional pulverizing ability can be remarkably improved.

As described above, the pulverization efficiency can be improved, that is, productivity can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view of an impinging airflow pulverizer of the present invention and an example of a flowchart of a pulverizing method in which the pulverizer and a classifier are combined. FIG. 2 is a sectional view taken along the line AA of FIG. 1, showing the inside of the crushing chamber. FIG. 3 is a diagram showing a main part of the acceleration tube. FIG. 4 is a view showing an example of the arrangement of the secondary air inlet in the sectional view taken along the line BB of FIG. FIG. 5, FIG. 6, and FIG. 7 are views showing specific examples of the cross section taken along the line CC of FIG. FIG. 8 and FIG. 9 are a schematic cross-sectional view of a conventional collision-type airflow pulverizer and a flow chart of a pulverization method. DESCRIPTION OF SYMBOLS 1 ... Powder material supply port, 2, 12 ... Acceleration tube 3 ... Compressed gas supply nozzle 4, ... Acceleration tube outlet 5 ... Crushing chamber, 6 ... Collision member 7, 17, 27 ... Collision member Collision surface of 8: crushing chamber wall, 9: discharge port 11: secondary air supply port, 15: powder raw material

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuhide Goseki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-3-109951 (JP, A) JP-A 4-48942 (JP, A)

Claims (5)

(57) [Claims] A collision member for pulverizing the powder raw material ejected from the acceleration tube by a collision force is disposed downstream of the acceleration tube for transporting and accelerating the powder raw material by a high-pressure gas, facing the acceleration tube outlet. In a collision type air current pulverizer provided with a pulverizing chamber, a plurality of powder material supply ports are provided in the acceleration tube, and a secondary air inlet is provided between the plurality of powder material supply ports and an acceleration tube outlet, The tip of the collision surface of the collision member has an apex angle of 110
A collision-type airflow pulverizer having a cone shape of not less than ゜ and less than 180 ゜. 2. A case where a distance between a plurality of powder material supply ports provided in the acceleration tube and an outlet of the acceleration tube is X, and a distance between the plurality of powder material supply ports and a secondary air inlet is Y. , X and Y are 2. The impingement airflow pulverizer according to claim 1, wherein the following formula is satisfied. 3. An apparatus according to claim 1, wherein the angle of introduction of the secondary air inlet provided in the acceleration tube satisfies 10 ° ≦ Ψ ≦ 80 ° with respect to the axial direction of the acceleration tube. The impingement airflow crusher as described. 4. A powder material is conveyed and accelerated by a high-pressure gas in an acceleration tube provided in any one of the collision-type airflow pulverizers, discharged into the grinding chamber from an acceleration tube outlet, and opposed to each other. In the pulverization method of crushing the powder raw material into fine particles by colliding with a collision member, the powder raw material is guided from a plurality of powder raw material supply ports to an upstream of the acceleration tube, and the plurality of powder raw material supply ports and the acceleration pipe outlet are connected to each other. The powdered raw material collides with a collision member having a conical shape with an apex angle of 110 ° or more and less than 180 °, and pulverizes the powdered material. Crushing further by secondary collision with the crushing chamber wall. 5. An air flow rate of a high-pressure gas for conveying and accelerating a powdery raw material introduced into the acceleration tube is aNm ³ / min, and an air flow rate of a secondary air is bNm ^3.
/ min and a and b The pulverization is performed under a condition satisfying the following condition.
The pulverization method described.