JP3093343B2 - Collision type air flow crusher and powder material crushing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impingement type air flow pulverizer using a jet air flow (high-pressure gas) and a method for pulverizing a powder material, and more particularly, to a toner or a toner used in an electrophotographic image forming method. The present invention relates to an impingement airflow pulverizer for efficiently producing a colored resin powder and a method of pulverizing a powder raw material.

[0002]

2. Description of the 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 material by the impact force.

The details will be described below with reference to FIG.

Acceleration tube 1 connected to compressed gas supply nozzle 2
A collision member 16 is provided opposite to the outlet 14 of the accelerating tube 3, and the flow of the high-pressure gas supplied to the accelerating tube 13 causes powder to flow into the inside of the accelerating tube 13 from the powder raw material supply port 1 connected to the middle of the accelerating tube 13. The body material 15 is sucked, injected together with a high-pressure gas to collide with the collision surface of the collision member 16, and is crushed by the impact. And, when used to pulverize the powder raw material 15 to a desired particle size,
A classifier is arranged between the powder material supply port 1 and the discharge port 9 to form a closed circuit, the powder material 15 is supplied to the classifier, the coarse powder is supplied from the powder material supply port 1, and pulverization is performed. Then, the pulverized material is returned to the classifier through the discharge port 9 and classified again, and the fine powder becomes a finely pulverized material having a desired particle size.

[0005] However, in the above conventional example, the acceleration tube 1
Since it is difficult to sufficiently disperse the powdered raw material 15 sucked into the inside 3 in a high-pressure air stream, the acceleration tube outlet 1
The powder stream ejected from 4 is separated into a stream having a high dust concentration and a stream having a small dust concentration.

Therefore, the powder flow hitting the opposing collision surface 17 becomes partial (local), and the efficiency is reduced.
Causes reduction in processing capacity. In addition, 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. Absent.

In addition, when the powder raw material 7 containing a large amount of coarse particles is sucked and introduced into the acceleration tube 13, 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 pulverization of particles inside the accelerating tube 13, a pulverizing tube provided with a high-pressure gas feed pipe for injecting a secondary high-pressure gas at a position before the accelerating tube outlet 14 is disclosed in Japanese Patent Publication No. Sho.
It has been proposed in JP-A-6-22778. This is intended to promote collision inside the acceleration tube 13 and is a useful means for a pulverizer that performs pulverization only inside the acceleration tube 13. It is not a useful method in the impingement type air current pulverizer. because,
If a secondary high-pressure gas is introduced to accelerate the collision in the accelerating tube 13, the carrier airflow due to the high-pressure gas introduced from the compressed gas supply nozzle 2 is obstructed, and the speed of the powder flow ejected from the accelerating tube outlet 14 is reduced. Will drop. Therefore, the impact force colliding with the collision member 16 decreases, and the crushing efficiency decreases, which is not preferable.

On the other hand, as shown in FIGS. 9 and 10, the collision surface of the collision member in such a conventional crusher is perpendicular or inclined (for example, in the direction of the high-pressure airflow on which the powder material is placed (axial direction of the acceleration tube)). 45 °) has been used (see JP-A-57-50554 and JP-A-58-143853).

However, in the case of the collision surface 17 perpendicular to the axial direction of the acceleration tube 13 as shown in FIG. 9, the powder material 15 blown out from the acceleration tube outlet 14 and the pulverized material reflected by the collision surface 17 collide. The ratio of coexistence near the surface 17 is high, so that the powder (powder raw material and pulverized material) near the collision surface 17
The concentration is high and the grinding efficiency is not good.

Further, the primary collision at the collision surface 17 is mainly performed, and it cannot be said that the secondary collision with the inner wall 8 of the crushing chamber 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. Therefore, it has been difficult to use the powder raw material at a high concentration.

In the crusher shown in FIG. 10, since the collision surface 27 is inclined with respect to the axial direction of the acceleration tube 13, the powder concentration near the collision surface 27 is smaller than that of the crusher shown in FIG. However, the collision force due to the high-pressure airflow is dispersed and decreases. Furthermore, it cannot be said that the secondary collision with the inner wall 8 of the crushing chamber is effectively used. For example, as shown in FIG. 10, when the angle of the collision surface 27 is 45 ° with respect to the acceleration tube,
There are few problems as described above when pulverizing a thermoplastic resin. However, since the impact force used for crushing at the time of collision is small and crushing due to secondary collision with the crushing chamber inner wall 8 is small, the crushing ability is 1 compared with the crusher of FIG.
The crushing ability falls to / 2 to 1 / 1.5.

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

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 by a fixing unit, a pressure roller, or a heating and pressing roller. 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, a toner or a colored resin powder for a toner is prepared by melt-kneading a mixture containing at least a binder resin and a colorant or a magnetic powder (and further containing a third component as necessary), and cooling the melt-kneaded product. Then, the cooled product is pulverized, and the pulverized product is classified. The crushing of the cooled product is generally performed by coarse pulverization (or medium pulverization) by a mechanical impact pulverizer, and then finely pulverized by a collision type air pulverizer using a jet stream. is there.

In such a case, in the conventional collision-type airflow pulverizer and the pulverization method as shown in FIG. 9, if the processing capacity is to be further improved, the powder material supply port 1 provided in the accelerating tube 13 has insufficient suction. Occurs, or a fusion product is generated on the collision surface 17, and stable production cannot be performed. Therefore, in order to more efficiently generate a toner or a colored resin powder for a toner used in an image forming method by an electrophotographic method, an efficient collision-type airflow pulverizer and a pulverization method that solve the above-mentioned problems are desired. I have.

[0017]

SUMMARY OF THE INVENTION An object of the present invention is to provide an efficient impingement type air current pulverizer and a method for pulverizing a powdery raw material in which the above problems are solved.

An object of the present invention is to provide an impinging airflow pulverizer for efficiently pulverizing a powder mainly composed of a thermoplastic resin and a method of pulverizing a powder raw material.

An object of the present invention is to provide an impinging airflow pulverizer for efficiently pulverizing a powder mainly composed of a thermoplastic resin and a method of pulverizing a powder raw material.

An object of the present invention is to provide an impingement airflow pulverizer capable of efficiently producing toner or colored resin particles for a toner used in a copier and a printer having a heating and pressing roller fixing means, and a method of pulverizing a powder material. Is to provide.

The object of the present invention is to provide an average particle size of 20 to 2000.
An object of the present invention is to provide an impingement airflow pulverizer capable of efficiently pulverizing resin particles having an average particle diameter of 3 to 15 μm and a method of pulverizing a powder raw material.

An object of the present invention is to provide a collision-type airflow pulverizer for efficiently pulverizing a powdery material by jetting powder from the outlet of the accelerating tube with good dispersion and preventing agglomeration of powder in the accelerating tube. Is to do.

An object of the present invention is to provide a collision type air flow capable of effectively performing a secondary collision in which the powder material injected from the outlet of the acceleration tube and colliding with the collision surface of the collision member further collides with the inner wall of the crushing chamber. An object of the present invention is to provide a pulverizer and a method for pulverizing a powder raw material.

[0024]

SUMMARY OF THE INVENTION The present invention is directed to an accelerating tube and a pulverizing chamber for conveying and accelerating a powder material by a high-pressure gas, and a pulverizing device for pulverizing the powder material ejected from the accelerating tube by an impact force. A collision-type airflow pulverizer provided with a collision member and provided in the pulverizing chamber with the collision member facing the outlet of the acceleration tube, wherein a plurality of powder material supply ports for supplying powder material to the acceleration tube are provided. Dispersing the powder material from the plurality of powder material supply ports and supplying the powder material into the acceleration tube, and introducing secondary air into the acceleration tube between the powder material supply port and the acceleration tube outlet. And a tilt angle () of the secondary air inlet with respect to the center axis of the acceleration tube satisfies 10 ° ≦ ψ ≦ 80 °, and the secondary air inlet is accelerated. The inclination angle (ρ) with respect to a cross section perpendicular to the central axis of the tube satisfies 10 ° ≦ ρ ≦ 80 °, and the collision Top collision surface tip portion of the wood angle 110
The present invention relates to a collision-type airflow pulverizer having a cone shape of not less than 180 ° and less than 180 °.

According to the present invention, there is provided a method of pulverizing a raw material, wherein the raw material is conveyed and accelerated by a high-pressure gas in an accelerating tube, and the raw material is ejected from an outlet of the accelerating tube into a pulverizing chamber, and collided with an opposing collision member. In the above, the powder raw material is dispersed from a plurality of powder raw material supply ports provided in the acceleration pipe and introduced into the acceleration pipe, and an acceleration provided between the powder raw material supply port of the acceleration pipe and the acceleration pipe outlet is provided. Secondary air is introduced into the accelerating tube from the tube secondary air inlet, and its introduction direction is set at an inclination angle (ψ) with respect to the central axis of the accelerating tube of 10 ° ≦ ψ ≦ 80 ° and perpendicular to the central axis of the accelerating tube. When the inclination angle (ρ) with respect to the cross section is set to 10 ° ≦ ρ ≦ 80 °, the powder raw material collides with the collision member having a cone shape having a vertex angle of 110 ° or more and less than 180 ° to pulverize the powder material, The ground material after collision is further collided with the inner wall of the grinding chamber to pulverize the powder material. To a method of grinding the powder material, characterized in that.

According to the collision type air current pulverizer and the method of pulverizing the powder raw material of the present invention, the powder as the raw material to be powdered can be efficiently pulverized to the order of several μm by utilizing the high-speed air flow.

In particular, a thermoplastic resin powder or a powder containing a thermoplastic resin as a main component can be efficiently pulverized to a size of several μm by utilizing a high-speed air flow.

Now, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic cross-sectional view of a collision type air current pulverizer of the present invention and a flow chart of a pulverization method combining a pulverization step using the pulverizer and a classification step using a classifier. The powder raw material 15 to be pulverized is supplied to the acceleration tube 3 from the powder raw material inlet 1 provided in the acceleration tube 3. Compressed gas such as compressed air is introduced into the acceleration tube 3 from the compressed gas supply nozzle 2, and the powder raw material 15 supplied to the acceleration tube 3 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.

According to the present invention, as shown in FIG. 2, which is a cross section taken along the line CC 'in FIG. A secondary air inlet 11 is provided between the powder material input port 1 and the acceleration tube outlet 4, and the secondary air is introduced into the acceleration tube 3 to disperse the powder in the acceleration tube 3. The powder is more uniformly ejected from the outlet 4 and efficiently collides with the opposing collision surface 7 of the collision member 6, so that the pulverization efficiency can be improved as compared with the related art.
The powder raw material 15 to be pulverized is dispersed and supplied to the acceleration pipe 3 from seven powder raw material supply ports 1 provided above the acceleration pipe 3 in FIG. A compressed gas such as compressed air is introduced from the compressed gas supply nozzle 2 into the accelerating tube 3, and the powder raw material 15
Is instantaneously accelerated to have a high speed. The powdery raw material 15 discharged from the acceleration pipe outlet 4 into the pulverizing chamber 51 at a high speed collides with the collision surface 7 of the collision member 6 and is pulverized. In such a crusher, a secondary air inlet 11 is provided between the powder raw material supply port 1 of the acceleration tube 3 and the acceleration tube outlet 4.
By introducing the secondary air into the acceleration tube 3, the suction capacity of the powder material supply port 1 is improved, and the powder material 1 in the acceleration tube 3 is improved.
5 are dispersed, the powder raw material 15 is more uniformly ejected from the acceleration tube outlet 4 and efficiently collided with the collision surface 7 of the opposing collision member 6, so that the pulverizability can be improved as compared with the related art. Here, the introduced secondary air contributes to break up and disperse the agglomeration of the powder raw material 15 moving at high speed in the acceleration tube 3. In addition, there is an effect of accelerating the flow along the inner wall of the acceleration tube, which is the portion where the acceleration gas flow velocity distribution is slow in the acceleration tube 3.

This will be described in more detail by showing enlarged side views of the acceleration tube in FIGS. As a result of intensive studies on the method of introducing the introduced secondary air, the following conclusions were reached.

That is, regarding the position of the introduction of the secondary air,
In FIG. 8, when the distance between the powder material inlet 1 and the acceleration tube outlet 4 is x, and the distance between the powder material inlet 1 and the secondary air inlet 11 is y, x and y are

[0032]

[Outside 3] When the condition was satisfied, good results were obtained.

Regarding the angle of introduction of the secondary air introduction port 11, assuming that the angle with respect to the axial direction of the acceleration tube is ψ (FIG. 5), ψ is 10 ° ≦ ψ ≦ 80 °, more preferably 20 °.
When the condition of ≤ψ≤80 ° is satisfied and the angle with respect to the cross-sectional direction perpendicular to the central axis of the accelerating tube is ρ (FIG. 6),
ρ is 10 ° ≦ ρ ≦ 80 °, more preferably 20 ° ≦ ρ ≦
When the condition of 80 ° was satisfied, good pulverization results were obtained.

Regarding the flow rate of the secondary air introduced, the flow rate of the carrier airflow by the high-pressure gas introduced from the compressed gas supply nozzle 2 is set to aNm ³ / min, and the secondary air introduced from the secondary air introduction port is set. When the total air volume of bNm ³ / min is

[0035]

[Outside 4] When pulverization was carried out under the conditions satisfying the above conditions, good results were obtained.

The technical idea of the present invention is to pulverize a powdery raw material by feeding a powdery raw material into a carrier airflow by a high-pressure gas introduced from a compressed gas supply nozzle, ejecting the raw material from an acceleration tube outlet, and colliding with an opposing collision member surface. In the collision type air current pulverizer, it is based on the idea that the dispersion state of the powder in the acceleration tube may affect the pulverization efficiency. That is, the powder raw material supplied from the accelerating tube flows into the accelerating tube in an agglomerated state, and thus the dispersion in the accelerating tube becomes insufficient. It was considered that the member surface could not be used effectively, and that the grinding efficiency was reduced. This phenomenon becomes more conspicuous as the amount of pulverization increases.

The present inventors have conceived of providing a plurality of powder material inlets and introducing secondary air to solve this problem. The present invention has been made based on the idea that the secondary air is introduced into the accelerating tube so as to disperse the powder raw material without disturbing the flow of the carrier air by the high-pressure gas. As the secondary air, either a highly compressed gas or a normal pressure gas may be used. It is very preferable to attach an opening / closing device such as a valve to the secondary air inlet to control the amount of introduced air.

The number of inlets to be installed at which position in the circumferential direction of the accelerating tube may be appropriately set according to the powder material, the target particle diameter, and the like. FIG. 6 shows an example in which eight secondary air inlets are attached in the circumferential direction of the acceleration tube as an example in FIG.
FIG. In this case, what distribution of the secondary air is introduced from the eight locations may be set as appropriate. The cross section of the accelerating tube is not limited to a circular shape.

The inner diameter of the acceleration tube outlet 4 is usually 10 to 100
mm and 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, excessive pulverization tends to occur, and 3
If it exceeds twice, the crushing efficiency tends to decrease.

On the other hand, in the crusher shown in FIG. 1, the collision surface 7 has a conical shape having an apex angle of 110 ° or more and less than 180 °, preferably near 160 °, so that the crushed material is substantially The particles are dispersed in the entire circumferential direction, cause secondary collision with the inner wall 8 of the grinding chamber, and are further ground. FIG. 8 is a diagram schematically showing a sectional view taken along the plane AA ′ of the collision-type airflow pulverizer shown in FIG. 1, and schematically shows a dispersion state of the pulverized material after collision at the collision surface 7. ing. From FIG. 8, it is found that in the airflow pulverizer of the present invention, the secondary collision of the pulverized material on the inner wall 8 of the pulverization chamber is effectively used. further,
In the crusher of the present invention, the crushed material is favorably diffused in the radial direction of the colliding member at the colliding surface 7 as shown in FIG. 1, so that the inner wall 8 of the crushing chamber is widely used for secondary collision. Therefore, 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, and the fusion of the (crushed) material on the collision surface 7 can be suppressed well. It is possible.

The powder raw material 15 introduced into the pulverizing chamber 5 is pulverized by primary collision at the collision surface 7 and then pulverized by secondary collision at the inner wall 8 of the pulverizing chamber. The crushed material is further crushed by tertiary (and quaternary) collision with the crushing chamber wall 8 and the side surface of the collision member 6 before being conveyed to the discharge port 9. 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 the newly supplied powder material 15.

As another example, FIG. 3 and FIG.
FIG. 1 is a cross-sectional view (cross-section taken along the line CC ′ in FIG. 1) in which one and four powder material supply ports 1 are provided. The cross section of the acceleration tube 3 is not limited to a circular shape.

The crushing chamber 5 of the impingement type air current crusher according to the present invention is not limited to the box type shown in FIG.

As described above, according to the apparatus and method of the present invention, the powder material in the acceleration tube is dispersed well, so that the powder material collides efficiently with the collision surface of the collision member, and the pulverization efficiency is improved. . That is, as compared with the conventional pulverizer, the processing capacity is improved, and the particle size of the obtained product can be made smaller with the same processing capacity.

Further, in the conventional example, since the powder raw material collides with the collision surface of the collision member in an agglomerated state, particularly when a powder mainly composed of a thermoplastic resin is used as the raw material, a fused material is easily generated. However, according to the present invention, the dispersed material collides with the collision surface of the collision member, so that a fusion product is not easily generated.

Further, in the conventional example, since the powder raw materials are agglomerated, excessive pulverization is liable to occur, and therefore, there is a problem that the particle size distribution of the obtained pulverized product is broad, but according to the present invention, In addition, over-pulverization can be prevented and a pulverized product having a sharp particle size distribution can be obtained.

Further, by efficiently introducing the secondary air, the ability of sucking air at the inlet of the powder raw material is improved, so that the capacity of conveying the powder raw material in the accelerating tube is improved, and the amount of the pulverization processing is reduced. It can be higher than before. The effect of the apparatus and method of the present invention becomes more remarkable as the particle diameter becomes smaller.

Further, in the conventional example, the powder raw material injected from the outlet of the acceleration tube and colliding with the collision surface of the collision member has a high proportion of the powder raw material injected from the outlet of the acceleration tube and has a high powder concentration. However, according to the present invention, the tip of the collision surface of the collision member has an apex angle of 110 ° or more and 1
Since the conical shape is less than 80 °, the pulverized material that has collided with the collision surface is reflected on the inner wall side of the pulverization chamber, so that the powder concentration does not increase or the pulverization efficiency is improved.

Further, the crushed material after colliding with the colliding surface is effectively subjected to secondary collision colliding with the inner wall of the crushing chamber, so that the crushing efficiency is further improved.

[0051]

【Example】

Example 1 100 parts by weight of a polyester resin (weight average molecular weight (M
w) = 50,000, Tg = 60 ° C. Phthalocyanine pigment 6 parts by weight Low molecular weight polyethylene 2 parts by weight Negative charge control agent 2 parts by weight (azo metal complex)

The above raw materials were mixed with a Henschel mixer to obtain a mixture. Next, the mixture is melted and kneaded at about 180 ° C. in an extruder, and then cooled and solidified.
The particles were coarsely pulverized into m particles. This coarsely pulverized product was used as a powder raw material 7 and pulverized by a pulverizer and a flow shown in FIGS. 1, 2, 5, 6, 7, and 8. As a classification means for classifying the pulverized powder into fine powder and coarse powder, a fixed wall type air classifier was used.

Here, in the impingement type air current pulverizer, the inner diameter of the outlet 4 of the acceleration tube 3 is 25 mm, and in FIGS. 5 and 6, x = 80 mm, y = 45 mm, ψ = 45 °, ρ = 40 ° The next air inlet 11 satisfies eight conditions in the circumferential direction, the collision member 6 is a columnar member made of aluminum oxide ceramic having a diameter of 60 mm, and the tip of the collision surface 7 has a vertex angle of 160 °. And a conical shape having The center axis of the accelerating tube 3 was coincident with the tip of the collision member 6. The closest distance from the acceleration tube outlet 4 to the collision surface 7 was 60 mm, and the closest distance between the collision member 6 and the inner wall 8 of the crushing chamber was 18 mm.

A flow rate of 6.4 Nm ³ / min (pressure 6.0 kg / cm ² ) from the compressed gas supply nozzle of the impingement type air flow pulverizer.
, And the powder raw material 15 was supplied at a rate of 48 kg / hour from the powder raw material supply port 1 shown in FIG. The pulverized powder material 15 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 3 together with the powder material 15 from the powder material supply port 1. As the secondary air, compressed air of 0.1 Nm ^{3 /} min (5.0 kg / cm ² ) was introduced from each of eight locations A, B, C, D, E, F, G and H in FIG.

[0055]

[Outside 5]

As a result, the fine powder had a volume average particle size of 7.5.
Pulverized powder of μm (measured by a Coulter counter) was collected at a rate of 48 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 this embodiment, the measurement was performed using a Coulter counter.

That is, a Coulter Counter TA-II type (manufactured by Coulter) was used as a measuring device, and an interface (manufactured by Nikkaki) for outputting the number distribution and volume distribution and a CX-1 personal computer (manufactured by Canon) were connected. The electrolyte is 1 grade using primary sodium chloride.
% NaCl aqueous solution is prepared. As a measuring method, a surfactant, preferably an alkylbenzene sulfonate, is used as a dispersant in 100 to 150 ml of the electrolytic aqueous solution.
Add 5 ml, and then add 2-20 mg of the measurement sample. The electrolytic 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 material used in Example 1 was mixed with
5 and FIG. 5 and FIG. 6, x = 80 mm, y = 45 mm, ψ = 45 °, ρ = 45 ° Secondary air inlet port: The condition of eight places in the circumferential direction is satisfied. The tip of the collision surface 7 had a conical shape having a vertex angle of 120 ° in a columnar shape made of an aluminum oxide ceramic having a diameter of 60 mm. The center axis of the accelerating tube 3 was coincident with the tip of the collision member 6. The closest distance from the acceleration tube outlet 4 to the collision surface 7 was 60 mm, and the closest distance between the collision member 6 and the inner wall 8 of the crushing chamber was 18 mm.

Compressed air of 6.4 Nm ³ / min (6 kgf / cm ² ) was introduced from the compressed gas supply nozzle of the impingement type air flow pulverizer, and the secondary air was A, B, C, D, and D in FIG.
0.1 Nm ³ / min from E, F, G and H
(5 kgf / cm ² ) of compressed air was introduced, and powder raw material 15 was supplied at a rate of 40 kg / hour from the powder raw material supply port 1 shown in FIG. The pulverized powder material 15 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 3 together with the powder material 15 from the powder material supply port 1.

As a result, the fine powder had a volume average particle size of 7.5.
Pulverized powder of μm (measured by a Coulter counter) was collected at a rate of 40 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 mixed with
5 and 6, x = 80 mm, y = 45 mm, ψ = 45 °, ρ = 45 ° secondary air inlet port. The condition of eight places in the circumferential direction is satisfied. Was made of an aluminum oxide-based ceramic having a diameter of 60 mm, and had a conical shape with the tip of the collision surface 7 having an apex angle of 120 °. The center axis of the accelerating tube 3 was coincident with the tip of the collision member 6. The closest distance from the acceleration tube outlet 4 to the collision surface 7 was 60 mm, and the closest distance between the collision member 6 and the inner wall 8 of the crushing chamber was 18 mm.

Compressed air of 6.4 Nm ³ / min (6 kgf / cm ² ) was introduced from the compressed gas supply nozzle of the impingement type air flow crusher, and the secondary air was A, B, C, D, and D in FIG.
0.1 Nm ³ / min from E, F, G and H
(5 kgf / cm ² ) of compressed air was introduced, and powder raw material 15 was supplied at a rate of 45 kg / hour from the powder raw material supply port 1 shown in FIG. The pulverized powder material 15 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 3 together with the powder material 15 from the powder material supply port 1.

As a result, the fine powder had a volume average particle size of 7.5.
Pulverized powder of μm (measured by a Coulter counter) was collected at a rate of 45 kg / hour. Further, even after the continuous operation for 6 hours, no fused product was generated.

Comparative Example 1 The pulverized raw material used in Example 1 was pulverized by a conventional collision type 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 14 is 25 mm. The accelerating tube 12 has a compressed gas supply nozzle 2
A compressed gas of Nm ³ / min (6 kgf / cm ² ) 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. Since the pulverized material colliding with the collision surface 17 is reflected in a direction opposite to the discharge direction from the accelerating tube, the concentration of the pulverized material and the powder raw material near the collision surface became extremely high. Therefore, if the supply rate of the powder raw material exceeds 4.5 kg / hour, fusion and agglomerates will start to occur on the collision surface 17 of the collision member 16, and the fusion may clog the grinding chamber or the classifier. Was. Therefore, it was necessary to reduce the pulverization throughput to 15 kg per hour, which was the limit of the pulverization ability.

When pulverization is performed so as to obtain a fine powder (pulverized product) having a weight average particle diameter of 11 μm, if the supply rate of the powder raw material exceeds 9 kg / hour, the powder material is crushed on the collision surface 17 of the collision member 16. , Agglomerates and aggregates began to form, which became the limit of the crushing ability.

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 current pulverizer shown in FIG. All the pulverizers are the same as the pulverizers used in Comparative Example 1, except that the collision surface 27 at the tip of the collision member 6 is a plane having an inclination of 45 ° with respect to the axial direction of the acceleration tube 12. It is.

The pulverized material colliding with the collision surface was reflected in a direction away from the acceleration tube outlet 14 as compared with Comparative Example 1, so that no fusion or agglomerate was generated on the collision surface 27 of the collision member 26. However, at the time of collision, the impact force was weakened, so that the pulverizing efficiency was poor, and only about 15 kg of fine powder (pulverized product) having a weight average particle size of 7.5 μm was obtained per hour.

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

Table 1 shows the results of Examples 1 to 3 and Comparative Examples 1 and 2 obtained as described above.

[0071]

[Table 1]

[0072]

As described above, according to the impingement type air current pulverizer and the method for pulverizing a powder raw material of the present invention, the accelerating tube, the pulverizing chamber and the accelerating tube for conveying and accelerating the powder raw material by the high-pressure gas are used. In a pulverizer equipped with a collision member for pulverizing a powder material to be spouted by a collision force, a plurality of powder material supply ports are provided in an acceleration tube so that the powder material is dispersed and supplied into the acceleration tube. In addition, the secondary air is spirally introduced to enhance the suction capability of the powder raw material, and the secondary air is jetted out of the accelerating tube with good dispersion, so that the crushed object collides with the collision surface of the collision member efficiently, so that the crushing efficiency is improved. .

Further, by setting the shape of the collision surface of the collision member to a specific cone shape, it is possible to prevent fusion and generation of agglomerates when the material to be pulverized is pulverized, thereby enabling stable operation of the apparatus. In addition, since the pulverized material strongly collides with the inner wall of the pulverization chamber, the conventional pulverization ability can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a collision type pulverizer of the present invention and an example of a flowchart of a pulverizing method of a powder raw material in which the pulverizer and a classifier are combined.

FIGS. 1 and 5 show one specific example of a powder material supply port.
5 is a cross-sectional view taken along the line CC ′.

FIGS. 1 and 5 show a specific example of a powder material supply port.
5 is a cross-sectional view taken along the line CC ′.

FIGS. 1 and 5 show a specific example of a powder material supply port.
5 is a cross-sectional view taken along the line CC ′.

FIG. 5 is a sectional view taken along the line AA ′ of FIG. 1 showing the grinding chamber.

FIG. 6 is a sectional view showing an acceleration tube of the collision type crusher of the present invention.

FIG. 7 is a sectional view showing an acceleration tube of the collision type crusher of the present invention.

FIG. 8 is a BB ′ of FIGS. 5 and 6 showing a secondary air supply port.
FIG.

FIG. 9 is a schematic cross-sectional view of a conventional collision type pulverizer and a flow chart of a pulverization method.

FIG. 10 is a schematic sectional view of a conventional collision type pulverizer and a flow chart of a pulverization method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Powder material supply port 2 Compressed gas supply nozzle 3 Acceleration pipe 4 Acceleration pipe outlet 5 Crushing chamber 6 Collision member 7 Collision surface 8 Crushing chamber inner wall 9 Discharge port 11 Secondary air supply port 13 Acceleration pipe 14 Acceleration pipe outlet 15 Powder Raw material 16 collision member 17 collision surface 26 collision member 27 collision surface

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuhide Goseki 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-3-109951 (JP, A) JP-A Heisei 4-150957 (JP, A) Japanese Utility Model 62-95749 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B02C 19/00 B02C 19/06

Claims (4)

(57) [Claims] An accelerating tube for conveying and accelerating a powder material by a high-pressure gas, a pulverizing chamber, and a collision member for pulverizing the powder material spouted from the accelerating tube by an impact force are provided. In a collision-type air-flow pulverizer provided in a pulverizing chamber opposite to an acceleration tube outlet, a powder raw material is supplied to the acceleration tube.
A plurality of powder material supply port for, the plurality of the powder material
Dispersed from the number of powder material supply ports and supplied into the acceleration tube
And, the pressurized-speed tube between the powder material supply port and the pressurized-speed tube outlet
An accelerating tube secondary air inlet for introducing secondary air therein is provided, and an inclination angle (ψ) of the secondary air inlet with respect to a center axis of the accelerating tube satisfies 10 ° ≦ ψ ≦ 80 °, The inclination angle (ρ) of the secondary air inlet with respect to the cross section perpendicular to the central axis of the acceleration tube satisfies 10 ° ≦ ρ ≦ 80 °, and the tip of the collision surface of the collision member has a vertex angle of 110 °.
A collision type air current pulverizer characterized by having a cone shape of not less than 180 ° and less than 180 °. 2. The distance between the powder material supply port provided in the acceleration tube and the acceleration tube outlet is x, and the distance between the powder material supply port and the acceleration tube secondary air introduction port provided in the acceleration tube is y. Then,
x and y are 2. The impingement airflow pulverizer according to claim 1, wherein the following formula is satisfied. 3. A method of pulverizing a raw material, wherein the raw material is conveyed and accelerated by a high-pressure gas in an accelerating tube, the raw material is ejected from an outlet of the accelerating tube into a pulverizing chamber, and collided with an opposing collision member. The powder material is dispersed from a plurality of powder material supply ports provided in the acceleration tube and introduced into the acceleration tube, and an acceleration tube provided between the powder material supply port and the acceleration tube outlet of the acceleration tube is provided. Secondary air is introduced into the acceleration tube from a secondary air inlet,
The introduction direction is such that the inclination angle (中心) with respect to the central axis of the acceleration tube is 10 ° ≦ ψ ≦ 80 °, and the inclination angle (ρ) with respect to a cross section perpendicular to the central axis of the acceleration tube is 10 ° ≦ ρ ≦ 80 °, The tip portion of the collision surface is crushed by crushing the powder material against a collision member having a cone shape with a vertex angle of 110 ° or more and less than 180 °,
A pulverizing method for a powdery raw material, wherein the pulverized material after the collision is further collided with the inner wall of the pulverizing chamber to pulverize the powdery raw material. 4. When the flow rate of a high-pressure gas for transporting and accelerating an object to be ground introduced into an acceleration pipe is aNm3 / min, and the flow rate of secondary air introduced into the acceleration pipe is bNm3 / min,
a and b The pulverization is performed under a condition satisfying the following condition.
A pulverization method for the powder raw material according to the above.