JP2014176835A - Classifier and pulverization classifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a classifier that can stably perform high-precision classification with such a constitution as to lead a mixture phase gas with not so large a proportion of a gas to a particulate matter to a dispersion chamber and a pulverization classifier using this classifier.SOLUTION: A classifier 100, which comprises a center core 3 and a separator core 4, having a powdery product outlet 7 at the center built after the other from above, in the interior of a cylindrical casing 2 having a pulverulent body supply port 1a to be supplied with an air stream and a pulverulent body material, and constitutes a dispersion chamber 5 surrounded by the upper inner wall of the cylindrical casing 2 and the center core 3 to disperse the pulverulent body material supplied with the air stream and a classification chamber 6 surrounded by the separator core 3, separator core 4, and the inner wall of the cylindrical casing 2 to centrifugally separate the pulverulent body material flowing out of the dispersion chamber 5 into fine powder and coarse powder, keeps the uppermost part of the dispersion chamber 5 equipped with a dispersion chamber commutator 60 that introduces an air stream separately from the primary air stream to generate a swirl air stream in the dispersion chamber 5.

Description

  The present invention relates to a classification device for selecting powder according to the size of particles, and a pulverization classification device using this classification device.

  Some manufacturing processes for toner used in an electrophotographic image forming apparatus include a classification process for classifying powder of toner material having a variation in particle diameter according to the particle diameter. As a classification device used in this classification step, as in Patent Documents 1 to 3, the powder is made to correspond to the particle diameter of the particles by causing a swirling airflow to act on the mixed phase gas and the mixed phase gas. There is known a classifying device that classifies the above.

  16 and 17 are explanatory views showing an example of a conventional classification device 100. FIG. FIG. 16 is an explanatory diagram of a cross section parallel to the vertical direction of the classification device 100. 17A is an explanatory diagram of a cross section taken along the line AA ′ in FIG. 16, and FIG. 17B is an explanatory diagram of a cross section taken along the line BB ′ in FIG. .

In the classification device 100, the dispersion chamber 5 is formed in the upper part of the cylindrical casing 2, the lower hopper 8 is formed in the lower part, and the classification chamber 6 is formed between the dispersion chamber 5 and the lower hopper 8. Connected to the dispersion chamber 5 is a powder material supply pipe 1 for supplying a primary air flow and raw material powder. Below the dispersion chamber 5, a cap-shaped center core 3 having a high center is attached so as to be fixed to the cylindrical casing 2, and between the outer periphery of the lower edge of the center core 3 and the inner wall of the cylindrical casing 2. An annular supply hole 3b through which the powder can pass is formed.
Below the center core 3, a cap-shaped separator core 4 having a high central portion is provided, and an annular coarse powder discharge hole 4 b is formed between the outer periphery of the lower edge of the separator core 4 and the inner wall of the cylindrical casing 2. In addition, a product powder discharge port 7 is formed at the center of the separator core 4. A space between the center core 3 and the separator core 4 is a classification chamber 6.

  As shown in FIG. 17A, the end of the powder material supply pipe 1 inside the dispersion chamber 5 is a supply port arranged along the inner peripheral surface of the cylindrical casing 2 in the dispersion chamber 5. . By supplying a high-pressure mixed phase gas from the powder material supply pipe 1 arranged in this way, as shown by an arrow C in FIGS. 16 and 17A, the primary swirling along the inner peripheral surface An air flow is formed.

A rectifier 9 provided with a secondary air inflow port through which a secondary air flow flows is disposed at a lower portion of a portion forming the classification chamber 6 of the cylindrical casing 2. As shown in FIG. 17B, the rectifier 9 has a configuration in which a plurality of louver plate portions 12 are arranged in an annular shape, and the secondary air inlet is configured by a slit between adjacent louver plate portions 12. Has been. The direction of the secondary air flow introduced from the slit is a direction in which the powder material descends while swirling in the classification chamber 6, and the powder material is dispersed by the secondary air flow, and , Accelerate the turning speed.
Moreover, a negative pressure is acting on the product powder discharge port 7, and an air flow to be sucked is formed. In such a classification chamber 6, it acts on each of coarse particles and product particles in a semi-free vortex formed by the secondary air flow flowing in from the slit and the air flow sucked by the product powder discharge port 7. Classification is performed by using different centrifugal forces.

Specifically, the powder delivered to the classification chamber 6 acts on the product powder discharge port 7 because the swirling airflow due to the secondary airflow acts on the powder, and the light particles with small particle size act on the product powder outlet 7 because the centrifugal force acting on the swirling airflow is small. It is sucked by the negative pressure and delivered to the next process as product powder as indicated by an arrow E4 in the figure.
On the other hand, the heavy particles having a large particle size have a large centrifugal force acting on the swirling airflow, so that the negative pressure acting on the product powder discharge port 7 cannot reach the product powder discharge port 7 but hits the upper surface of the separator core 4 and the shade thereof. And slides outward along the surface of the shape and reaches the lower hopper 8 from the coarse powder discharge hole 4b. The powder that has reached the lower hopper 8 is discharged as a coarse powder from the lower opening 11 as indicated by an arrow E5 in the figure.

  However, in the classifying apparatus 100 shown in FIGS. 16 and 17, as shown in FIG. 17A, the mixed gas obtained by mixing the airflow flowing into the dispersion chamber 5 with the powder is formed on the inner peripheral surface of the cylindrical casing 2. It only flows from one place. In such a configuration in which the airflow flows from only one location, the swirling speed of the multiphase gas in the dispersion chamber 5 is slow, and the multiphase gas having a slow swirling speed passes through the supply hole 3b and is secondary in the classification chamber 6. Even if the turning speed is accelerated by the air flow, the turning speed may be insufficient. If the swirl speed is insufficient, the difference in centrifugal force acting on the powder particles will be small, and coarse particles will be mixed into the product powder, and product powder particles will be mixed into the coarse powder. There was a decline.

  Patent Documents 1 to 3 describe a configuration in which a swirling airflow generating means for generating a swirling airflow in the dispersion chamber is arranged in the dispersion chamber (hereinafter referred to as “dispersion chamber swirling airflow generating means”) as in the rectifier 9. ing. This dispersion chamber swirling air flow generating means is configured to include a plurality of slit-shaped inlets in the circumferential direction through which airflow flows along the circumferential direction of the cylindrical inner peripheral surface of the dispersion chamber. By providing such a dispersion chamber swirling air flow generating means, the swirling speed of the mixed phase gas in the dispersion chamber 5 is increased, and the mixed phase gas passes through the supply hole 3b and is moved by the secondary air flow in the classification chamber 6. A sufficient turning speed when the turning speed is accelerated can be obtained. Thereby, the classification accuracy can be improved.

  However, in the classifying device described in Patent Document 1, the dispersion chamber swirling airflow generating means is provided at a position lower than the ceiling of the dispersion chamber. In such a configuration, a region where gas stays is formed in the space above the ceiling above the dispersion chamber swirling air flow generating means, and a part of the powder supplied to the dispersion chamber retains this gas. If it enters and stays in a space where it accumulates and accumulates to some extent, it may fall due to its own weight. When the powder falls at a certain accumulation timing, the amount of powder delivered from the dispersion chamber to the classification chamber varies, and stable classification cannot be performed.

  On the other hand, in the classifiers described in Patent Documents 2 and 3, the dispersion chamber swirling airflow generation means is arranged at the top of the dispersion chamber. Thus, a stable classification can be performed without forming a space where the powder stays between the ceiling of the dispersion chamber.

In order to form a stable swirling air flow in the dispersion chamber by the dispersion chamber swirling air flow generating means, a certain amount of flow is required as an air flow taken into the dispersion chamber from a plurality of locations on the cylindrical inner peripheral surface.
In the classifying devices described in Patent Documents 2 and 3, the air flow taken into the dispersion chamber by the dispersion chamber swirling air flow generating means from a plurality of locations on the cylindrical inner peripheral surface is a mixed phase in which powder and gas to be classified are mixed. It is a gas stream.
In the classifying apparatus described in Patent Documents 2 and 3, the pulverizing apparatus for supplying powder to the classifying apparatus is a jet mill type pulverizing apparatus, and this type of pulverizing apparatus collides a compressed gas with a raw material to be pulverized together with a collision member. It is the structure made to collide at high speed with respect to. Since the powder is collided by the compressed gas, the ratio of the gas to the powder is very large in the mixed phase gas containing the powder after pulverization. By introducing this mixed-phase gas into the dispersion chamber by the dispersion chamber swirl airflow generating means, an airflow having a flow rate sufficient to form a stable swirl airflow can be obtained.

On the other hand, a mechanical pulverizer that pulverizes an object to be pulverized by rotating a columnar rotor (rotor) in a cylindrical stator (fixed cylinder) is known as a pulverizer. Since mechanical pulverizers are more energy efficient than jet mill type pulverizers, they have recently been replaced by jet mill types.
However, in the mechanical pulverizer, the mixed phase gas containing the pulverized powder has a very small ratio of the gas to the powder as compared with the jet mill method. And even if such a mixed phase gas is guided into the dispersion chamber by the dispersion chamber swirl airflow generating means, there arises a problem that an airflow having a sufficient flow rate cannot be obtained to form a stable swirl airflow.

  Such a problem is not limited to the configuration in which the mixed phase gas obtained by the mechanical pulverizer is guided to the dispersion chamber, but the same problem occurs if the configuration is such that a mixed phase gas having a small ratio of gas to the powder is guided to the dispersion chamber. obtain.

  The present invention has been made in view of the above-described problems, and its object is to stably perform accurate classification with a configuration in which a mixed phase gas having a small ratio of gas to powder is guided to a dispersion chamber. It is to provide a classification device and a pulverization classification device using the classification device.

  In order to achieve the above object, the invention of claim 1 includes a center core and an opening at the center in a cylindrical casing having a powder material supply port through which a powder material is supplied together with an air current. A separator core, and a dispersion chamber which is surrounded by the upper inner wall of the casing and the center core and disperses the powder material supplied together with the air flow, and is surrounded by the inner walls of the center core, the separator core and the casing. In the classifying device that constitutes a classification chamber for centrifuging the powder material flowing from the dispersion chamber into fine powder and coarse powder, separately from the airflow flowing with the powder at the top of the dispersion chamber, A plurality of inlets are provided in the circumferential direction in which gas that does not contain powder from the outside flows along the circumferential direction of the cylindrical inner peripheral surface of the dispersion chamber, and the dispersion is achieved by gas flowing in from the inlet. Generates swirling airflow in the room Is characterized in further comprising a dispersing chamber whirling airflow generating means for.

In the present invention, the dispersion chamber swirl airflow generating means generates a swirl airflow by introducing a gas not containing powder from the outside, apart from the airflow flowing in with the powder. For this reason, even if it is the structure which guides the mixed phase gas with which the ratio of the gas with respect to powder is not large to a dispersion | distribution chamber, the stable swirl | vortex airflow can be formed.
Further, since such a dispersion chamber swirling airflow generating means is provided at the uppermost part of the dispersion chamber, it is possible to stably perform highly accurate classification similarly to the classification devices described in Patent Documents 2 and 3. .

  According to the present invention, there is an excellent effect that accurate classification can be stably performed with a configuration in which a mixed phase gas having a small ratio of gas to powder is guided to the dispersion chamber.

Explanatory drawing of the classification apparatus which concerns on embodiment. Explanatory drawing of the grinding | pulverization classification apparatus which concerns on embodiment. Expansion explanatory drawing of an injection nozzle. 1A is an explanatory diagram of a cross section parallel to the horizontal direction of a conventional classifier, FIG. 1A is an explanatory diagram of a cross section shown by the AA ′ cross section in FIG. 1, and FIG. 'The cross-sectional explanatory drawing shown in a cross section. Explanatory drawing of the difference in the flow of the airflow in the dispersion chamber depending on the presence or absence of the ultrafine powder discharge pipe, (a) is an explanatory view of a configuration not including the ultrafine powder discharge pipe, and (b) is a configuration including the ultrafine powder discharge pipe. Illustration. Explanatory drawing of the classification apparatus of Example 2. FIG. The expansion explanatory drawing of a part of the classification apparatus of Example 2, (a) is an expansion explanatory drawing of a center core, (b) is an enlarged explanatory drawing of a separator core. Explanatory drawing of the angle of the vertex of a center core. Explanatory drawing of the center core of Example 4. FIG. Explanatory drawing of the classification apparatus of Example 5, (a) is explanatory drawing of the whole classification apparatus, (b) is an expansion explanatory drawing of a separator core. Explanatory drawing of the grinding | pulverization classification apparatus of Example 6. FIG. Explanatory drawing of the grinding | pulverization classification apparatus of Example 7. FIG. Explanatory drawing of the grinding | pulverization classification apparatus of the prior art example 1. FIG. Explanatory drawing of the classification part of an elbow jet classifier. Explanatory drawing of the grinding | pulverization classification apparatus of the prior art example 2. FIG. Explanatory drawing about the cross section parallel to the perpendicular direction of the conventional classifier. Explanatory drawing about the cross section parallel to the horizontal direction of the conventional classifier, (a) is explanatory drawing about the cross section shown by the AA 'cross section in FIG. 16, (b) is BB in FIG. 'The cross-sectional explanatory drawing shown in a cross section. Explanatory drawing of the classification apparatus of the other example of the conventional swirling airflow classifier. Explanatory drawing of an example of the grinding | pulverization classification apparatus provided with the jet mill type grinding | pulverization apparatus.

Hereinafter, an embodiment of a classification device to which the present invention is applied will be described.
FIG. 2 is an explanatory view schematically showing a pulverizing and classifying device 200 including the classifying device 100 according to the present invention.
In the pulverizing and classifying apparatus 200, the toner material (arrow E1 in the figure) supplied by the raw material supply feeder 201 is pulverized by the pulverizing apparatus 202. The pulverized toner material is collected by the collection cyclone 203 (arrow E2 in the figure). Next, it is supplied to the classification supply injection nozzle 205 by the quantitative feeder 204, and is supplied to the classification device 100 by the classification supply injection nozzle 205 (arrow E3 in the figure).

The classification device 100 is a coarse powder classifier that classifies product powder containing product particles having a particle diameter to be a product and coarse powder composed of coarse particles having a particle diameter larger than that of the product powder. The product powder classified by the classification device 100 is collected by a product powder collecting cyclone 207 and delivered to the next process by the product powder supply feeder 208 (arrow E7 in the figure).
The coarse powder classified by the classification device 100 is returned to the pulverization device 202 by the coarse powder conveyance injection nozzle 206. In the pulverizing and classifying apparatus 200, closed-circuit pulverization is configured so that the pulverized powder is repeatedly pulverized and classified.

FIG. 3 is an enlarged explanatory view of an injection nozzle 500 that can be used for the classification supply injection nozzle 205 and the coarse powder transfer injection nozzle 206.
The injection nozzle 500 is supplied with compressed air (arrow F <b> 1 in the figure) having a high discharge speed from the nozzle unit 502 as the toner material (the finished product of the mechanical pulverizer) supplied to the hopper 501.
At this time, compressed air having a high discharge speed passes through a narrow flow path, so that the vicinity of the lower opening portion of the hopper 501 in which the nozzle portion 502 is disposed has a pressure caused by a Venturi effect that can be explained based on Bernoulli's theorem. Decreases. Due to this pressure drop, the toner in the hopper 501 is sucked and supplied to the next process.

  The pulverizing apparatus 202 shown in FIG. 2 has a cylindrical pulverizer, and a mechanical pulverizer having a cylindrical rotor disposed inside the stator so that the central axis thereof overlaps the stator and is rotatable about the central axis. Machine. On the outer peripheral surface of the rotor of this mechanical pulverizer, a large number of concaves and convexes parallel to the central axis are formed along the circumferential direction, and the inner peripheral surface of the stator is also parallel to the central axis. A large number of narrow irregularities are formed along the circumferential direction. Then, as the rotor rotates at high speed, the object to be crushed that passes through the gap between the inner peripheral surface of the stator and the outer peripheral surface of the rotor is pulverized.

FIG.1 and FIG.4 is explanatory drawing of the classification apparatus 100 of this embodiment with which the grinding | pulverization classification apparatus 200 is provided.
FIG. 1 is an explanatory diagram of a cross section parallel to the vertical direction of the classification device 100. 4A is an explanatory view of a cross section taken along the line AA ′ in FIG. 1, and FIG. 1B is an explanatory view of a cross section taken along the line BB ′ in FIG. .
The classification device 100 includes a cylindrical casing 2, a powder material supply pipe 1, a center core 3, a separator core 4, a rectifier 9, a product powder discharge pipe 10, and a lower opening 11.

  The cylindrical casing 2 forms a columnar space, and the columnar space is partitioned from above into a dispersion chamber 5, a classification chamber 6, and a lower hopper 8 that is a large-diameter powder passage chamber. The powder material supply pipe 1 guides the powder material together with the air current from the powder material supply port 1a at the tip thereof into the dispersion chamber 5, as indicated by an arrow E3 in the figure.

The shape of the cylindrical casing 2 is not particularly limited as long as it is a cylindrical shape, and can be appropriately selected according to the purpose. There is no restriction | limiting in particular as a structure of a cylindrical casing 2, a magnitude | size, and a material, According to the objective, it can select suitably.
At the upper end of the cylindrical casing 2, a powder material supply pipe 1 for supplying a mixed phase gas composed of gas and powder into the dispersion chamber 5 is disposed. The flow of air supplied together with the powder from the powder material supply pipe 1 is called a primary air flow.

The center core 3 is disposed below the dispersion chamber 5 and spatially partitions the dispersion chamber 5 and the classification chamber 6. The center core 3 has a high shade at the center, and a gap between the outermost portion of the shade and the inner wall of the cylindrical casing 2. The dispersion plate forms supply holes 3b which are classified powder supply holes through which the powder material can pass. The separator core 4 is a cap-shaped classification plate that is disposed below the classification chamber 6 to spatially partition the classification chamber 6 and the lower hopper 8 and has a high center. A coarse powder discharge hole 4b, which is a large-diameter powder discharge hole through which the powder material can pass, is formed by a gap between the outermost outer portion of the shade shape of the separator core 4 and the inner wall of the cylindrical casing 2.
Here, the shade shape is a side surface shape having a conical top surface, a certain thickness, a bottom surface having no conical shape, and a hollow shape on the bottom surface side.

The rectifier 9 is a classification chamber swirl air flow generating means that introduces gas from outside the columnar space in the cylindrical casing 2 and generates a swirl air flow in the classification chamber 6. The product powder discharge pipe 10 is a small-diameter powder discharge pipe that discharges the product powder, which is a small-diameter powder, together with the air current to the product powder discharge port 7 that is an opening formed in the center of the separator core 4. The lower opening 11 is a large-diameter powder outlet that does not reach the product powder outlet 7 but passes through the coarse powder outlet 4b and discharges the coarse powder flowing into the lower hopper 8 to the outside.
The product powder discharge port 7 is an inlet of the product powder discharge pipe 10, and the product powder discharge pipe 10 is connected to the product powder collection cyclone 207. By operating the product powder collection cyclone 207, the product powder discharge pipe 10 10, a negative pressure for sucking air in the classification chamber 6 is generated at the product powder discharge port 7.

The classifier 100 converts the powder supplied from the powder material supply pipe 1 into product powder discharged from the product powder discharge port 7 and coarse powder discharged from the lower opening 11 depending on the size of the particles. Select.
Furthermore, a dispersion chamber rectifier 60 which is a dispersion chamber swirling air flow generating means for generating a swirling air flow in the dispersion chamber 5 is provided at the top of the dispersion chamber 5. Dispersion chamber rectifier 60 has a slit shape in which a gas that does not include powder material from the outside flows in along the circumferential direction of the cylindrical inner peripheral surface of dispersion chamber 5 separately from the primary air flow that flows in with powder material. A plurality of inflow ports are provided in the circumferential direction. As gas flows in from the slit-shaped inlet, a swirling airflow is generated in the dispersion chamber 5 as indicated by an arrow C in the figure.

  As shown in FIG. 4A, the dispersion chamber rectifier 60 has a shape in which a plurality of dispersion chamber louver plates 120 are provided in an annular shape. The slit formed between the adjacent dispersion chamber louver plate portions 120 among the annular dispersion chamber louver plate portions 120 has an air flow (hereinafter referred to as powder) in the dispersion chamber 5 in order to generate a swirling air flow. (Referred to as “dispersion chamber secondary air flow”). An air flow is supplied from a dispersion chamber air supply means (not shown) to the dispersion chamber secondary air flow supply channel 60a formed outside the annular dispersion chamber louver plate portion 120. As a result, the dispersion chamber secondary air flow that has passed through the slit-shaped inlet formed by the dispersion chamber louver plate portion 120 is introduced into the dispersion chamber 5. As a result, a swirling airflow is formed in the dispersion chamber 5 to promote the dispersion of the powder material, and the swirling speed of the powder material supplied to the dispersion chamber 5 is accelerated.

A part of the cylindrical casing 2 forming the classification chamber 6 is a rectifier 9 in which a plurality of louver plate portions 12 are annularly provided on the outer periphery of the separator core 4 as shown in FIG. A slit formed between adjacent louver plate portions 12 among the louver plate portions 12 provided in an annular shape serves as a secondary air inflow port through which the secondary air flow flows. When an air flow is supplied from an air supply means (not shown) to a secondary air flow supply passage 9a formed outside the louver plate portion 12 provided in an annular shape, it passes through a slit formed by the louver plate portion 12. The secondary air flow is introduced into the classification chamber 6. The direction of the secondary air flow introduced from the slit is a direction in which the powder material descends while swirling in the classification chamber 6, and the powder material is dispersed by the secondary air flow, and , Accelerate the turning speed.
In the classification chamber 6, the powder material is efficiently centrifugally classified into coarse powder and fine powder by the quick swirling of the secondary air flow that has evenly flowed from the outer periphery of the rectifier 9, thereby improving the classification accuracy. Can do.

  The powder material supplied into the dispersion chamber 5 falls while swirling by the swirling airflow formed by the primary air flow and the dispersion chamber rectifier 60. When it reaches the position of the center core 3, it is transported along the upper surface of the center core 3 to the outer peripheral side of the center core 3, and is delivered to the classification chamber 6 from the supply hole 3b. The powder material delivered to the classification chamber 6 is subjected to a swirling airflow due to the secondary air flow, and the light particles having a small particle size have a small centrifugal force acting due to the swirling airflow, so that the negative pressure acting on the product powder discharge port 7 is reduced. Sucked by. On the other hand, the heavy particles having a large particle size have a large centrifugal force acting on the swirling airflow, so that the negative pressure acting on the product powder discharge port 7 cannot reach the product powder discharge port 7 but hits the upper surface of the separator core 4 and the shade thereof. Slides outward along the surface. And it reaches the lower hopper 8 from the coarse powder discharge hole 4b.

The fine powder sucked into the product powder discharge port 7 is delivered to the product powder collection cyclone 207 via the product powder discharge pipe 10 and then delivered to the next level process.
The coarse powder that has reached the lower hopper 8 is discharged from the circular lower opening 11 formed at the lowermost end of the lower hopper 8 and delivered to the crushing device 202.

  The classification principle in the classification device 100 is as follows. That is, in the classification chamber 6, the primary air flow and the dispersion chamber secondary air flow that flow in with the powder from the dispersion chamber 5, the secondary air flow that flows in from the outer peripheral side, and the product powder discharge port 7 are discharged to the outside. The air flow is activated. When the powder material is swirled semi-freely by these air flows, the centrifugal force and the centripetal force acting on the particles differ depending on the size (mass) of the particles in the powder material.

The classifier 100 of FIG. 1 generates a swirling air flow by a dispersion chamber rectifier 60, in addition to a primary air flow that flows in along with the powder material, and a gas that does not contain powder from the outside flows as a secondary air flow in the dispersion chamber. Let For this reason, even if it is the structure which guides the mixed phase gas with which the ratio of the gas with respect to powder material is not large to the dispersion | distribution chamber 5, the stable swirl | vortex airflow can be formed. In addition, since such a dispersion chamber rectifier 60 is provided at the top of the dispersion chamber 5, accurate classification can be performed stably.
As described above, the classifying device 100 is configured to guide the mixed phase gas, which does not have a large proportion of the gas to the powder material, to the dispersion chamber 5, and can perform accurate classification stably.

Here, a conventional pulverizing and classifying apparatus will be described.
FIG. 13 is an explanatory view schematically showing an example of a conventional pulverizing and classifying apparatus 200 (hereinafter referred to as “conventional example 1”).
In the pulverizing and classifying apparatus 200 shown in FIG. 13, the toner material (arrow G <b> 1 in the drawing) supplied by the raw material supply feeder 201 is pulverized by the pulverizing apparatus 202. The pulverized toner material is collected by a collection cyclone 203 (arrow G2 in the figure) and supplied to an elbow jet classifier 400 as a classifier by a quantitative feeder 204 (arrow G3 in the figure).

The elbow jet classifier 400 classifies the toner material into fine powder (arrow G4 in the figure), medium powder (arrow G5 in the figure), and coarse powder (arrow G6 in the figure) by the Coanda effect according to the size of the particles. Of the classified powder, the coarse powder returns to the pulverizer 202 via the coarse powder collecting cyclone 209 as indicated by an arrow G5 in the figure. In the pulverizing and classifying apparatus 200, the coarse powder classified by the elbow jet classifier 400 returns to the pulverizing apparatus 202, and the coarse powder is configured to be pulverized and classified so as to repeat the pulverization and classification.
As the elbow jet classifier 400 using the Coanda effect, an elbow jet classifier manufactured by Nippon Steel Industry Co., Ltd. can be used.

The basic principle of the elbow jet classifier is shown below.
In the elbow jet classifier, the movement of particles in the airflow is governed by the inertial force of each particle and the fluid resistance received from the airflow, and the flight trajectory of each particle varies depending on its particle size.

FIG. 14 is an explanatory diagram of a classifying portion of the elbow jet classifier 400.
An arrow G3 in FIG. 14 indicates the flow of raw materials such as toner materials supplied to the elbow jet classifier 400 by the quantitative feeder 204, and an arrow J in FIG. 14 indicates an air flow supplied for classification.
The raw material supplied to the elbow jet classifier 400 is accelerated by an unillustrated ejector section, and is ejected from the raw material supply nozzle 301 together with feed air, and the jet flow tends to flow along the Coanda block 302 due to the “Coanda effect”. .
“Coanda effect” means the property of a jet that flows along the wall when it is placed only on the side. Even when the outlet of the jet and the downstream wall are curved, it flows along the wall. Due to this effect, the feed air containing the raw material powder ejected from the raw material supply nozzle flows along the Coanda block.

At this time, each particle in the raw material is ejected into the classifier with different inertial forces depending on the particle diameter (mass), but fine particles have a small inertial force, so they are stalled by the fluid resistance and flowed together with the jet flow. Fly in the vicinity of 302 (arrow G4 in FIG. 14). On the other hand, since coarser particles have a large inertial force, classification is performed by flying farther (arrow G5 in FIG. 14 indicates medium powder and arrow G6 indicates the flow of coarse powder).
A classification edge 303 that can be set at an arbitrary position is provided on the airflow discharge side, and several classified products for each target particle size can be obtained at the same time (three divisions in the configuration shown in FIG. 14).

However, recent toners require higher quality for higher image quality, energy saving or higher speed, and require low temperature softening and a sharp distribution with small particle size. Therefore, conventional elbow jets have fine powder classification of 4 [μm] or less. There is a problem that the required quality is not satisfied because the accuracy is limited. In order to solve this problem, in recent years, a mechanical classifier that classifies by centrifugal force generated by a rotor rotating at high speed and centripetal force generated by suction of a blower passing through the rotor is known. As such mechanical classifiers, for example, TSP, TTSP, ATP classifiers manufactured by Hosokawa Micron, turbo scifiers manufactured by Nissin Engineering Co., Ltd., CFS-HD manufactured by Condachs, etc. are known.
By using such a mechanical classifier, it was possible to classify the fine powder with high accuracy and ensure the required quality.
On the other hand, a coarse powder classifier that can efficiently classify coarse powder with a mechanical pulverizer is required.

  FIG. 15 is an explanatory view schematically showing a second example (hereinafter, referred to as “conventional example 2”) of a conventional pulverizing and classifying apparatus 200 provided with a classifying apparatus 100 as a swirling airflow classifier. .

In the pulverizing and classifying apparatus 200 shown in FIG. 15, the toner material (arrow E <b> 1 in the drawing) supplied by the raw material supply feeder 201 is pulverized by the pulverizing apparatus 202. The pulverized toner material is collected by the collection cyclone 203 (arrow E2 in the figure) and supplied to the classification device 100 by the quantitative feeder 204 (arrow E3 in the figure).
The classification device 100 is a coarse powder classifier that classifies product powder containing product particles having a particle diameter to be a product and coarse powder composed of coarse particles having a particle diameter larger than that of the product powder. The product powder classified by the classification device 100 is collected by a product powder collecting cyclone 207 and delivered to the next process by a product powder supply feeder 208.
The classification device 100 of Conventional Example 2 is the classification device 100 described with reference to FIGS. 16 and 17.

FIG. 18 is an explanatory diagram of a classifying device 100 as another example of a conventional swirling air classifier.
The classification device 100 of FIG. 18 differs from the classification device 100 of FIG. 16 in that it includes a dispersion chamber rectifier 60 that generates a swirling airflow in the dispersion chamber 5. Moreover, the point which the ceiling of the dispersion | distribution chamber 5 is comprised with the cup-shaped upper cover 101 differs from the classification apparatus 100 of FIG.
The classifying apparatus 100 described with reference to FIGS. 16 and 17 has the same configuration as a DS classifier manufactured by Nippon Pneumatic Co., Ltd., and FIG. The configuration is the same as that of the Pneumatic DSX classifier.

  A classification device 100 shown in FIG. 18 includes a dispersion chamber 5, a classification chamber 6, and a lower hopper 8. The powder material supply pipe 1 for supplying the primary air flow and the powder material to the upper outer peripheral surface of the dispersion chamber 5 so that the primary air flow and the like flow along the cylindrical inner peripheral surface of the dispersion chamber 5. It is connected. A cap-shaped center core 3 having a high center is attached under the dispersion chamber 5, and an annular supply hole 3 b for supplying powder material to the classification chamber 6 is formed around the periphery of the center core 3. Has been.

A cap-shaped separator core 4 with a high center is attached under the classification chamber 6, and this separator core 4 is a member for guiding fine powder in the classification chamber 6 to the product powder discharge port 7. An annular coarse powder discharge hole 4 b for supplying coarse powder to the lower hopper 8 is formed around the periphery of the separator core 4.
Fine powder in the classification chamber 6 is discharged from the product powder discharge pipe 10 connected to the product powder discharge port 7 by the suction force of a blower (not shown).
Further, a part of the cylindrical casing 2 forming the classification chamber 6 is a rectifier 9 in which a plurality of louver plates are provided in an annular shape and a secondary air inlet is formed by a slit-like gap between the louver plates. ing. The secondary air flow from the rectifier 9 disperses the powder material and accelerates the turning speed.

  The classifying principle of the classifying apparatus 100 shown in FIG. 18 works on the coarse particles and fine particles in the powder material when the secondary air flow flowing in the classification chamber 6 causes the powder material to flow anti-freely on the swirl. This utilizes the fact that centrifugal force and centripetal force are different. Accordingly, it is desirable that the coarse particles and fine particles dispersed in the classification chamber 6 are quickly classified into coarse particles and fine particles without reaggregation.

The classifying apparatus 100 shown in FIGS. 16 and 17 also disperses the raw material by the swirling airflow in the dispersion chamber 5 and supplies the raw material to the classification chamber 6 from the annular supply hole 3b. Then, a high-speed swirling flow is formed by the secondary air flow supplied from the rectifier 9, and the coarse powder and the product powder are separated.
Moreover, the classification apparatus 100 shown in FIG. 18 is of a type in which the raw material is further dispersed by flowing a secondary air flow from the dispersion chamber rectifier 60 into the dispersion chamber 5.

In the classification device 100 shown in FIGS. 16 and 17, the swirl speed in the dispersion chamber 5 becomes insufficient, and the classification accuracy may be lowered.
On the other hand, in the classification device 100 shown in FIG. 18, the secondary air flow flowing from the dispersion chamber rectifier 60 can make the swirl speed in the dispersion chamber 5 sufficient, and can suppress the degradation of the classification accuracy. .
However, in the configuration shown in FIG. 18, the ceiling of the dispersion chamber 5 is constituted by the cup-type upper lid 101, and the dispersion chamber rectifier 60 is positioned lower than the ceiling of the dispersion chamber 5. In such a configuration, a region where gas stays is formed in the space between the ceiling above the dispersion chamber rectifier 60 and a part of the powder supplied to the dispersion chamber 5 stays in this gas. Enter the space and stay. And if it accumulates to some extent, it may fall by its own weight. As described above, when the powder falls at a certain accumulation timing, the amount of the powder delivered from the dispersion chamber 5 to the classification chamber 6 varies, and stable classification cannot be performed.

  On the other hand, in the classification device 100 of the present embodiment shown in FIG. 1, the secondary air flow flowing from the dispersion chamber rectifier 60 can make the swirl speed in the dispersion chamber 5 sufficient, It is possible to improve the dispersibility of the inflowing powder fluid and suppress the deterioration of the classification accuracy. Further, since the dispersion chamber rectifier 60 is disposed at the uppermost part of the dispersion chamber 5, it is possible to prevent the powder from collecting near the ceiling of the dispersion chamber 5, and the powder delivered from the dispersion chamber 5 to the classification chamber 6. The amount is stable and stable classification can be performed.

  As shown in FIGS. 16 and 18, the conventional classification device 100 includes an ultrafine powder discharge pipe 55 that discharges fine powder so as to extend from the center of the ceiling of the dispersion chamber 5 into the dispersion chamber 5. Prepare. In these configurations, a negative pressure is generated in the ultrafine powder discharge pipe 55 and the air in the dispersion chamber 5 is sucked, but is opened downward. As a result, the product powder or coarse powder having a particle size larger than the ultrafine powder is prevented from being sucked into the ultrafine powder discharge pipe 55 so as to oppose gravity, and only the ultrafine powder is to be discharged from the ultrafine powder discharge pipe 55. Is.

On the other hand, unlike the conventional classification apparatus 100, the classification apparatus 100 of FIG. 1 has a configuration in which the dispersion chamber 5 does not include the ultrafine powder discharge pipe 55. The ceiling part of the classification apparatus 100 of FIG. 1 is constituted by a flat plate-type upper lid 101, and the upper lid inner surface 101f of the upper lid 101, which is the upper surface of the dispersion chamber 5, is a flat surface without a member protruding downward.
By supplying the dispersion chamber secondary air flow by the dispersion chamber rectifier 60 with the upper surface of the dispersion chamber 5 being flat, a high-speed swirling flow is generated in the dispersion chamber 5.

The height (H1) of the dispersion chamber 5 of the classification device 100 of FIG. 1 is lower than the height (H2 and H3) of the dispersion chamber 5 of the conventional classification device 100, and the dispersion chamber 5 is narrow (the volume is small). ) Configuration.
When the flow rate of the air flow combining the primary air flow flowing in from the powder material supply pipe 1 and the dispersion chamber secondary air flow flowing in from the dispersion chamber rectifier 60 is constant, the smaller the dispersion chamber 5 is, the more the swirling air flow in the dispersion chamber 5 is. The turning speed of becomes faster. Thereby, dispersibility improves and a powder material moves to the classification chamber 6 quickly.

In the conventional classification device 100 shown in FIGS. 16 and 17, since the height (H2) of the dispersion chamber 5 is high, the swirl flow formed by the airflow flowing into the dispersion chamber 5 reaches the annular supply hole 3b. Stall. At this time, the powder material contained in the airflow may re-aggregate and be delivered to the classification chamber 6.
When the ultrafine powder discharge pipe 55 is opened with a slow swirling airflow, not only the ultrafine powder to be discharged but also the product powder is discharged from the ultrafine powder discharge pipe 55, and the classification point is changed to change the product powder discharge pipe 10 The recovery rate of the product powder discharged from the product will be reduced.

When the amount of gas with respect to the powder material in the mixed phase gas is large and the flow rate of the primary air flow is large as in the case of a jet mill type pulverizer as the pulverizer 202, the swirl airflow becomes faster and the ultrafine powder discharge pipe 55 It is also possible to discharge only ultrafine powder.
However, the pulverizing / classifying device 200 of the present embodiment uses a mechanical pulverizer as the pulverizing device 202 in order to improve energy efficiency, and the flow rate of the primary airflow cannot be increased. In such a configuration in which the flow rate of the primary airflow cannot be increased, it is difficult to discharge only the ultrafine powder with the ultrafine powder discharge pipe 55.

Further, in order to collect the powder material pulverized by the mechanical pulverizer 202 by the collection cyclone 203 and supply it to the classifier 100, a new supply method is adopted in this embodiment.
The reason for this is as follows.
That is, the static pressure inside the collection cyclone 203 for collecting the powder material pulverized by the mechanical pulverizer is very high (generally −20 [Kpa] to −35 [Kpa]). On the other hand, the in-machine static pressure of the classification system 100 of the classification system that flows in the secondary air flow from the rectifier 9 is low (−10 [Kpa] to −15 [Kpa]). Since the airflow flows from the lower static pressure to the higher one, the mixed phase gas in the collection cyclone 203 is supplied to the classification device 100 even if the collection cyclone 203 and the classification device 100 described above are directly connected. I can't. For this reason, it is necessary to adopt a new supply method.

Therefore, since the edge is cut once by the collection cyclone 203, the flow rate (Q) of the toner powder fluid (mixed phase) supplied to the inlet of the classification device 100 is as small as 1 to 3 [m ³ / h], most of which It is supplied via the classification supply injection nozzle 205.
Even a configuration using a mechanical pulverizer can be solved if the air supplied to the classifier can be increased by a pressurization method as in combination with a jet mill pulverizer. However, the compressed air needs to be 10 [m ³ / min] to 30 [m ³ / min] for supply, and the energy efficiency is greatly reduced.

When a secondary air flow of the outside air suction method is used for supply, the static pressure inside the classifier is greatly reduced (approaching atmospheric pressure at −10 [Kpa] or less), and the swirling speed in the dispersion chamber is increased. However, when the ultrafine powder discharge pipe 55 is used, the static pressure in the ultrafine powder discharge pipe 55 is high (−10 [Kpa] to −15 [Kpa]), so that the product area is exhausted and cannot be used.
The influence of the static pressure also extends to the classification chamber 6, and the static pressure of the classification chamber 6 is reduced in the same manner as the dispersion chamber 5. Therefore, the swirling speed is reduced by reducing the inflow of the secondary air flow from the rectifier 9 necessary for classification. When the static pressure in the classification chamber 6 is lowered, the static pressure in the product powder discharge pipe 10 with respect to the classification chamber 6 is increased, so that not only product powder but also coarse powder is mixed and classification accuracy is lowered.

  In addition, the classification device 100 shown in FIG. 18 has a lower dispersion chamber 5 than the classification device 100 shown in FIGS. 16 and 17, but the dispersion chamber 5 has a dispersion chamber rectifier to increase the swirl speed. Since 60 is disposed, the ultrafine powder discharge pipe 55 cannot be utilized. Further, since the upper lid 101 of the dispersion chamber 5 is curved, a part of the toner swirling due to the swirling airflow rises, and toner stays on the ceiling (upper surface) of the dispersion chamber 5 to increase the toner concentration in the dispersion chamber 5. This will reduce the dispersibility.

  On the other hand, the classification apparatus 100 shown in FIG. 1 is the classification apparatus shown in FIG. 18 until the dispersion chamber rectifier 60 is provided in the dispersion chamber 5 in order to supplement the flow rate of the powder fluid supplied from the powder material supply pipe 1. 100. However, the upper lid 101 has no curved portion, and its lower surface (the upper surface of the dispersion chamber 5) is a flat surface with no protruding members, and the height of the dispersion chamber (H1) is further minimized. Thereby, the speed of a swirl airflow can be made faster than the classification apparatus 100 shown in FIG. 18, and dispersibility can be improved.

The classifier 100 of FIG. 1 has a low dispersion chamber height (H1) and the dispersion chamber 5 is narrow, so that there is no stagnation of swirling airflow and high-speed swirling occurs, so that dispersibility is greatly improved.
Further, by eliminating the ultrafine powder discharge pipe 55, the powder material is all of the primary air flow supplied from the powder material supply pipe 1 and the dispersion chamber secondary air flow supplied from the dispersion chamber rectifier 60. It becomes possible to discharge from the product powder discharge port 7 provided in the classification chamber 6. Thereby, only coarse powder, especially coarse particles contained in the pulverized powder material can be efficiently sent to the lower hopper 8 and discharged from the lower opening 11. The coarse powder discharged from the lower opening 11 is returned to the pulverizer 202 again by the coarse powder injection nozzle 206 and finely pulverized.

FIG. 5 is an explanatory view of the difference in the flow of airflow in the dispersion chamber 5 depending on the presence or absence of the ultrafine powder discharge pipe 55, and FIG. 5A is an explanatory view of a configuration that does not include the ultrafine powder discharge pipe 55. (B) is an explanatory view of a configuration including an ultrafine powder discharge pipe 55.
In the classifying device 100 of FIG. 1, the volume of the dispersion chamber 5 is minimized so that a fast swirling airflow reaches the classification chamber 6 through the annular supply hole 3b. When the dispersion chamber 5 is narrowed as in the classifying apparatus 100 shown in FIG. 1 and an ultrafine powder discharge pipe 55 is further provided as shown in FIG. 5B, the dispersion chamber 5 is further separated by the ultrafine powder discharge pipe 55. Narrow. Thereby, if the flow rates of the primary air flow and the dispersion chamber secondary air flow are the same, the flow velocity of the swirling air flow may be further increased.

  However, since the height of the dispersion chamber 5 is low, the insertion ratio of the ultrafine powder discharge pipe 55 is increased, the distance between the ultrafine powder discharge pipe 55 and the center core 3 is short, and the ultrafine powder discharge pipe 55 is provided for the swirling airflow. It becomes an obstacle and the flow is disturbed. When the swirling airflow is disturbed as indicated by arrows C1 and C2 in FIG. 5B, the powder material swirling with the airflow enters the inside of the ultra fine powder discharge pipe 55. In order to prevent this entry, even if the valve of the ultrafine powder discharge pipe 55 is completely closed, the powder material enters up to the valve surface.

On the other hand, if it is the structure which does not provide the ultrafine powder discharge pipe | tube 55, since it can suppress that disorder arises in a swirl | vortex airflow as shown by the arrow C in Fig.5 (a), it is like the classification apparatus 100 shown in FIG. Moreover, it is best that the surface of the dispersion chamber 5 is a flat surface.
In the pulverizing and classifying apparatus 200 of the present embodiment, fine powder is classified by a mechanical classifier (not shown), and the classifying apparatus 100 is used as a coarse powder classifier. For this reason, it is not necessary to classify the ultrafine powder with the classifier 100.

If the ultrafine powder discharge pipe 55 is provided in the classification device 100 shown in FIG. 1, the necessary ultrafine powder (3 [μm]) cannot be classified, and the product powder is also discharged from the ultrafine powder discharge pipe 55. Therefore, the classifier 100 preferably has a configuration that does not include the ultrafine powder discharge pipe 55. Further, as described above, since the height of the dispersion chamber 5 is minimized, the classification device 100 does not include the ultrafine powder discharge pipe 55 from the viewpoint that the turbulent airflow is disturbed when the ultrafine powder discharge pipe 55 is present. Is preferred.
For classification of ultrafine powder in an area of 3 [μm] or less, a TSP classifier or TTSP classifier manufactured by Hosokawa Micron is preferable, and classification of ultrafine powder is performed using the classification apparatus 100 shown in FIG. 1 suitable for coarse powder classification. Is unnecessary. A part of the ultra fine powder in this region is considerably cut by the collection efficiency of the collection cyclone 203 that collects the powder material pulverized by the mechanical pulverizer 202.

The ultra fine powder separated from the product powder by a mechanical classifier (not shown) or the collection cyclone 203 can be reused as a raw material. Specifically, the prescription of resin, wax, carbon, charge control material, etc., which constitutes the toner, the addition ratio is determined according to the prescription ratio as a fine powder recycle product, and the toner raw material goes through the mixing, kneading, cooling and crushing processes Use as.
In the pulverizing and classifying apparatus 200 of the present embodiment, mixing of excess fine powder (ultra fine powder) and coarse powder can be suppressed with respect to the product powder having the target particle diameter. Moreover, the excessive fine powder which generate | occur | produces can be reused efficiently, and the efficiency of power consumption can be improved. By using such a pulverizing and classifying apparatus 200 in the pulverizing and classifying step in the dry toner manufacturing method, a toner having a sharp particle size distribution can be efficiently obtained.

The pulverizing and classifying apparatus 200 of the present embodiment uses a mechanical pulverizer as the pulverizing apparatus 202.
Examples of the mechanical pulverizer include those described in Patent Documents 6 to 10.
The mechanical pulverizer uses water-cooling of the rotating cylinder (rotor) and further increases the rotating speed of the rotating cylinder (circumferential speed 130 [m / s] → 160 [m / s] → 180 [m / s]. Is expanding). As a result, a fine pulverization region (11 [μm] → 9 [μm] → 6 [μm]), which has been able to be pulverized only by the jet mill method, is now possible. In this mechanical pulverization method, pulverization is repeated by the grinding force generated in the gap between the rotating cylinder and the uneven surface provided in parallel to the outer periphery thereof and the residence time passing through the gap. For this reason, since the pulverization efficiency is high and the generation amount of CO ₂ is suppressed, the replacement from the jet mill type pulverizer is progressing from the environmental aspect.

  The fine powder area pulverization with a mechanical pulverizer makes it difficult to obtain a sharp classification with a three-division classifier (elbow jet) that can simultaneously cut coarse powder and fine powder, which were the mainstream. Came. In other words, the dispersibility in the classifier decreased due to the decrease in bulk density due to atomization, and the desired particle size could not be secured. Therefore, when combined with a mechanical pulverizer, a single classifier has become necessary for both fine and coarse powders.

In order to classify the coarse powder contained in the toner having a low bulk density, the following three points are required.
First, a large amount of air is introduced at a high speed to reduce the dust concentration in the classifier.
Second, the toner dispersed in the classifier is quickly classified.
Third, the powder material can be processed in large quantities.
The classifying device according to the present invention is an airflow (swirl airflow) classifying device that can satisfy these three requirements.

  Since the mechanical pulverizer passes through a small gap parallel to the outer periphery of the rotating cylinder rotating at high speed and performs pulverization, it is temporarily collected by the collecting cyclone 203 shown in FIG. It is indispensable to perform classification by coarse powder classification (classifying apparatus 100) as the next step.

Here, a pulverizing and classifying apparatus including a conventional jet mill type pulverizing apparatus will be described.
FIG. 19 is an explanatory view of an example of a pulverizing and classifying apparatus 200 including a jet mill type jet mill pulverizing apparatus 222. In the pulverizing and classifying apparatus 200 shown in FIG. K1) The powder material is sent to the classification device 100 (arrow K2 in the figure). As the classification device 100, the one shown in FIGS. 16 and 17 or the one shown in FIG. 18 can be used. In this classification device 100, product powder containing product particles having a particle size to be a product (arrow K3 in the figure), coarse powder made of coarse particles having a particle diameter larger than the product powder (arrow K4 in the figure), and product powder Is classified into ultrafine powder (arrow K7 in the figure) made of ultrafine particles having a smaller particle diameter. The product powder classified by the classification device 100 is collected by a product powder collecting cyclone 207 and delivered to the next process by the product powder supply feeder 208 (arrow K6 in the figure).

The ultrafine powder classified by the classification device 100 is collected and reused as a raw material (arrow K8 in the figure). On the other hand, the coarse powder classified by the classifier 100 is transferred to the jet mill type pulverizer 222 (arrow K4 in the figure), pulverized by the jet mill type pulverizer 222, and transferred to the classifier 100 (FIG. Middle arrow K5).
In the case of a jet mill type pulverizer, since a large amount of compressed air generated by pulverization is processed and classified, as shown in FIG. 19, pulverization and classification can be performed simultaneously.

  On the other hand, in the pulverizing and classifying apparatus 200 shown in FIG. 2, since the pulverizing apparatus 202 is a mechanical pulverizer, it is essential to perform edge cutting with the collection cyclone 203.

  Hereinafter, specific examples in which pulverization classification is performed by the pulverization classification apparatus 200 including the classification apparatus 100 according to the present invention will be described. In addition, each Example shown below is an example and does not limit the application range of this invention. In addition, a multisizer manufactured by Coulter Counter was used for the particle size measurement in each example and each comparative example.

[Example 1]
A mixture of 80% by weight of polyester resin, 15% by weight of carbon black, and 5% by weight of WAX was melt kneaded with an extruder, cooled, solidified and crushed, and then manufactured by Hosokawa Micron. The toner raw material was obtained by coarse pulverization with an ACM pulverizer. The toner material was pulverized and classified using a pulverizing and classifying apparatus 200 shown in FIG.
As the pulverizing apparatus 202 for finely pulverizing the coarsely pulverized toner raw material, a turbo mill RS type manufactured by Mechanical Freund Turbo was used.
As the classification device 100, the classification device shown in FIG. 1 was used.

  When pulverization / classification was performed with the pulverization / classification apparatus 200 as described above, the following toner pulverization particle size was obtained by supplying raw materials of 150 [kg / hr]. That is, the weight average particle diameter is 6.5 [μm], the fine powder content of 4 [μm] or less is 54.0 [number%] in number average, and the coarse powder content of 12.7 [μm] or more is weight average. The toner pulverized particle size was 1.4 [wt%].

[Comparative Example 1]
Using the same kneaded product as in Example 1, pulverization classification was performed using the pulverization classification apparatus 200 shown in FIG. As the classification device 100, the conventional classification device 100 shown in FIGS. 16 and 17 was used.
When pulverization / classification was performed with the pulverization / classification apparatus 200 as described above, the following toner pulverization particle size was obtained by supplying the raw material of 130 [kg / hr]. That is, the weight average particle size is 6.6 [μm], the fine powder content of 4 [μm] or less is 65.0 [number%] in number average, and the coarse powder content of 12.7 [μm] or more is weight average. A toner particle size of 2.5% by weight was obtained.

[Comparative Example 2]
Using the same kneaded product as in Example 1, pulverization classification was performed using the pulverization classification apparatus 200 shown in FIG. As the classification device 100, the conventional classification device 100 shown in FIG. 18 was used.
When pulverization / classification was performed with the pulverization / classification apparatus 200 as described above, the following toner pulverization particle size was obtained by supplying raw materials of 140 [kg / hr]. That is, the weight average particle size is 6.6 [μm], the fine powder content is 4 [μm] or less, the number average is 63.0 [number%], and the coarse powder content is 12.7 [μm] or more. A toner particle size of 2.0% by weight was obtained.

In the classification device 100 shown in FIG. 1 used in Example 1, the swirling speed is increased and the dispersibility is improved at the same time as the stagnation of the dispersion chamber 5 is reduced. Further, since the superfine powder discharge pipe 55 is not provided in the dispersion chamber 5, all of the primary air flow supplied together with the powder material and the dispersion chamber secondary air flow supplied from the dispersion chamber rectifier 60 are classified. Since the whole amount is discharged from the product powder discharge port 7, the classification point is increased.
Further, in the classifying apparatus 100 shown in FIG. 1, since the lower surface of the upper lid 101 (the upper surface of the dispersion chamber 5) is flat, the swirling flow in the dispersion chamber 5 is not stagnated and is accurately dispersed. Therefore, classification accuracy is improved and a sharp distribution is obtained as compared with the conventional classification device 100 used in the comparative example.
The results of each example and each comparative example are shown in Table 1.

[Example 2]
The classifying apparatus 100 shown in FIG. 6 was used as the classifying apparatus 100 for the pulverizing and classifying apparatus 200 of Example 1. FIG. 6 is an explanatory diagram of the classification device 100 according to the second embodiment, FIG. 7A is an enlarged explanatory diagram of the center core 3 provided in the classification device 100 according to the second embodiment, and FIG. It is an expansion explanatory view of separator core 4 with which classification device 100 of Example 2 is provided.
The classification device 100 according to the second embodiment includes a through-hole 31 that is a dispersion chamber opening that communicates with the inside of the product powder discharge pipe 10 including the product powder discharge port 7 at the center of the center core 3 of the dispersion chamber 5.
As shown in FIG. 7A, when the diameter of the through hole 31 is D2, the opening area A2 is “A2 = (D2 / 2) ² × π”. Moreover, as shown in FIG.7 (b), when the diameter of the product powder discharge port 7 is set to D1, the opening area A1 will be "A1 = (D1 / 2) ² * (pi)".

In Example 2, the opening area A2 of the through hole 31 and the opening area A1 of the product powder discharge port 7 satisfy the following expression (1).
(A1 × 1/10) ≦ A2 ≦ (A1 × 1/3) (1)

As in Example 2, by providing the through-hole 31 leading to the product powder discharge port 7 of the separator core 4 of the classification chamber 6, a part of the fine powder dispersed in the dispersion chamber 5 is quickly sent to the product powder discharge pipe 10. It can be discharged. Then, a powder material that is not classified from the through hole 31 is sent to the classification chamber 6. With such a configuration, since the classifying chamber 6 and the classifying chamber 6 that generate a high-speed swirling air flow without any stagnation are classified twice, it is possible to perform multi-stage classification with one classifying device 100. Accuracy is improved.
The suction force from the through hole 31 is performed by the suction force in the product powder discharge pipe 10.

  The classification device 100 according to the second embodiment shown in FIG. 6 is similar to the classification device 100 of FIG. 1 in that the dispersion chamber 5 is made as narrow as possible, so that the swirling airflow in the dispersion chamber 5 is reduced as compared with the conventional classification device. Speed is greatly improved. As the speed of the swirling air flow increases, the inertial force acting on the particles increases, and smaller particles also swirl on the cylindrical wall side in the dispersion chamber 5 and reach the annular supply hole 3b. For this reason, the powder material collected at the center of the center core 3 is in a state of being rich in fine particles. In order to quickly collect and collect the collected fine particles on the product powder discharge pipe 10 side, a through-hole 31 to the center core 3 is opened, and the suction force due to the negative pressure in the product powder discharge pipe 10 is used to make the center core 3 Collect fine particles from the center of

Since the particle characteristics differ depending on the target particle diameter at the classification point of the fine particles, it is necessary to set the opening area A2 of the through hole 31 according to the particle characteristics. Thus, the classification point in the dispersion chamber 5 can be controlled by changing the setting of the opening area A2 of the through hole 31.
Thus, in Example 2, the function as a classification chamber is also added to the dispersion chamber 5 by utilizing the increase in the flow velocity of the swirling airflow in the dispersion chamber 5.

As a specific apparatus of Example 2, the opening area A2 of the through hole 31 was set to “A1 / 5” in the classification apparatus 100 shown in FIG.
When pulverization / classification was performed with the pulverization / classification apparatus 200 as described above, the following toner pulverization particle size was obtained by supplying raw materials of 150 [kg / hr]. In other words, the weight average particle size is 6.5 [μm], the fine powder content of 4 [μm] or less is 52.0. [Number%] on the number average, and the coarse powder content of 12.7 [μm] or higher is weight. An average toner particle size of 1.2 [% by weight] was obtained.

Example 3
In the classification device 100 of the present embodiment, the vertex angle (angle α1 in FIG. 8) of the isosceles triangle represented in the projection drawing of the center core projected from the side is 100 [°] or more and 160 [°. It is as follows. By changing the angle α1 of the apex of the center core 3, the speed of the swirling airflow in the dispersion chamber 5 can be adjusted according to the required quality of the toner. When combined with the two-stage classification described in the second embodiment, the classification accuracy is further increased. Will improve.

As a specific device of the third embodiment, in the classification device 100 shown in FIG. 6, the opening area A2 of the through hole 31 is set to “A1 / 5”, and the angle α1 shown in FIG. 8 is set to 150 [°]. did.
When pulverization / classification was performed with the pulverization / classification apparatus 200 as described above, the following toner pulverization particle size was obtained by supplying raw materials of 150 [kg / hr]. That is, the weight average particle size is 6.45 [μm], the fine powder content of 4 [μm] or less is 51.0 [number%] in number average, and the coarse powder content of 12.7 [μm] or more is weight average. A toner pulverized particle size of 1.0% by weight was obtained.

Example 4
As shown in FIG. 9, the pulverizing and classifying apparatus 200 according to the second embodiment includes a tubular member 32 protruding upward at the center of the center core 3, and the upper end of the tubular member 32 is connected to the through hole 31. It is the composition which becomes. The protruding amount L1 of the tubular member 32 is preferably in the range of 0 [mm] to 50 [mm]. By providing such a short tubular member 32, the tubular member 32 rises up the center core 3 in accordance with the particle diameter and particle characteristics, and in the unlikely event that coarse particles are mixed into the fine particles sucked from the through holes 31. By pushing out, the ingress of coarse powder can be cut. Thereby, the classification accuracy of the coarse powder at the time of two-stage classification is improved.

As a specific device of the fourth embodiment, in the classification device 100 shown in FIG. 6, the opening area A2 of the through hole 31 is set to “A1 / 5”, and the angle α1 shown in FIG. 8 is set to 150 [°]. Furthermore, the protruding amount of the tubular member 32 was set to 30 [mm].
When pulverization / classification was performed with the pulverization / classification apparatus 200 as described above, the following toner pulverization particle size was obtained by supplying raw materials of 150 [kg / hr]. That is, the weight average particle size is 6.45 [μm], the fine powder content of 4 [μm] or less is 50.0. [Number%] in number average, and the coarse powder content of 12.7 [μm] or more is weight. An average toner particle size of 0.9 [wt%] was obtained.

Example 5
The classification device 100 shown in FIG. 10 was used as the classification device 100 with respect to the pulverization classification device 200 of Example 1. FIG. 10A is an explanatory diagram of the classification device 100 of the fifth embodiment, and FIG. 10B is an enlarged explanatory diagram of the separator core 4 provided in the classification device 100 of the fifth embodiment.
In Example 5, the product powder discharge port 7 protrudes upward, and a plurality of pieces are arranged in the circumferential direction along the circular edge of the product powder discharge port 7, and guides the airflow flowing into the product powder discharge port 7. The guide vane 41 is provided. The protruding amount L2 of the guide blade 41 is preferably in the range of 0 [mm] to 100 [mm].

  By providing the guide blade 41 as in the fifth embodiment, it is possible to prevent the coarse powder from entering the product powder discharge port 7 due to the protrusion of the guide blade 41 even if the coarse powder rises up the separator core 4. Thereby, the jump of the coarse powder in the classification chamber 6 is further reduced, and the classification accuracy is improved.

As a specific device of the fifth embodiment, in the classification device 100 shown in FIG. 10, the opening area A2 of the through hole 31 is set to “A1 / 5”, and the angle α1 shown in FIG. 8 is set to 150 [°]. Then, the guide vane 41 shown in FIG. 10B was arranged with a protruding amount of 80 [mm].
When pulverization / classification was performed with the pulverization / classification apparatus 200 as described above, the following toner pulverization particle size was obtained by supplying raw materials of 150 [kg / hr]. That is, when the weight average particle size is 6.40 [μm], the fine powder content of 4 [μm] or less is 49. [number%] on the number average, and the coarse powder content of 12.7 [μm] or higher is 0 on the weight average. A toner pulverized particle size of 0.7% by weight was obtained.

Example 6
In Example 6, the pulverization / classification apparatus 200 shown in FIG. 11 was used. The configuration shown in FIG. 11 does not include the quantitative feeder 204 and the classification supply injection nozzle 205, and the configuration shown in FIG. 2 is that the powder material is supplied from the collection cyclone 203 directly to the classification device 100 by the injection feeder 211. And different.
By changing the supply mechanism for supplying the powder material to the classification device 100 to the injection feeder 211, the line configuration is simple and energy saving is achieved. Furthermore, dispersion of the powder material proceeds to the classification device 100 simultaneously with the conveyance by the injection feeder 211, and when used in combination with the classification device 100 of Example 5, the amount of coarse powder jumped in the classification chamber 6 is further reduced, and the classification accuracy is improved. improves.

As a specific apparatus of Example 6, the classification apparatus 100 shown in FIG. 10 was used for the pulverization classification apparatus 200 shown in FIG. Then, the opening area A2 of the through hole 31 is set to “A1 / 5”, the angle α1 shown in FIG. 8 is set to 150 [°], and the guide blade 41 shown in FIG. ].
Then, using the same kneaded product as in Example 1, the pulverized finished product was sent to the classification device 100 by the injection feeder 211 shown in FIG.
When pulverization / classification was performed with the pulverization / classification apparatus 200 as described above, the following toner pulverization particle size was obtained by supplying raw materials of 150 [kg / hr]. That is, when the weight average particle size is 6.40 [μm], the fine powder content of 4 [μm] or less is 49. [number%] on the number average, and the coarse powder content of 12.7 [μm] or higher is 0 on the weight average. A toner pulverized particle diameter of 6% by weight was obtained.

Example 7
In Example 7, the pulverizing and classifying apparatus 200 shown in FIG. 12 was used. The configuration shown in FIG. 12 is different from the configuration shown in FIG. 11 in that a double damper 212 for controlling the in-machine pressure and a secondary air adjustment nozzle 213 are provided after the collection cyclone 203.
As in Example 7, the double damper 212 and the secondary air adjustment nozzle 213 are arranged after the collection cyclone 203, and the feeder that supplies the classification device 100 is changed to the injection feeder 211, so No pulsation. Thereby, the jump of coarse powder in the classification chamber 6 is further reduced, and the classification accuracy is improved.

As a specific apparatus of Example 7, the classification apparatus 100 shown in FIG. 10 was used for the pulverization classification apparatus 200 shown in FIG. Then, the opening area A2 of the through hole 31 is set to “A1 / 5”, the angle α1 shown in FIG. 8 is set to 150 [°], and the guide blade 41 shown in FIG. ].
Then, using the same kneaded product as in Example 1, the pulverized ascending product was sent to the classification device 100 by the injection feeder 211 via the double damper 212 and the secondary air adjusting nozzle 213 shown in FIG.
When pulverization / classification was performed with the pulverization / classification apparatus 200 as described above, the following toner pulverization particle size was obtained by supplying raw materials of 150 [kg / hr]. That is, when the weight average particle size is 6.40 [μm], the fine powder content of 4 [μm] or less is 49. [number%] on the number average, and the coarse powder content of 12.7 [μm] or higher is 0 on the weight average. A toner pulverized particle size of 0.5% by weight was obtained.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
In a casing such as a cylindrical cylindrical casing 2 having a powder material supply port such as a powder material supply port 1a to which a powder material is supplied together with an air current, a center core such as a center core 3 in order from the top, and a center A dispersion core 5 having a separator core such as a separator core 4 having an opening such as a product powder discharge port 7 and the like, surrounded by an upper inner wall of the casing and a center core, and for dispersing the powder material supplied together with the air flow A classification device 100 that constitutes a dispersion chamber and a classification chamber such as a classification chamber 6 that is surrounded by the inner wall of the center core, the separator core, and the casing and that centrifuges the powder material flowing from the dispersion chamber into fine powder and coarse powder. In a classifier such as a gas, a gas not containing powder flows from the outside along the circumferential direction of the cylindrical inner peripheral surface of the dispersion chamber, in addition to the airflow flowing together with the powder, into the uppermost part of the dispersion chamber. The inlet A plurality in the circumferential direction, the gas from the inlet comprises a dispersion chamber whirling airflow generating means such as a dispersion chamber rectifier 60 to generate the whirling airflow in the dispersion chamber by flowing.
According to this, as described in the above-described embodiment, it is possible to stably perform accurate classification with a configuration in which the mixed phase gas that does not have a large proportion of gas to the powder material is guided to the dispersion chamber 5.
(Aspect B)
In aspect A, the upper surface of the dispersion chamber is planar.
According to this, as described in the above embodiment, it is possible to prevent stagnation in the swirling airflow in the dispersion chamber and to form a stable swirling airflow, so that more accurate classification can be performed stably. it can.
(Aspect C)
In the aspect A or B, the center portion of the center core is provided with a dispersion chamber opening such as a through hole 31 communicating with the inside of the opening.
According to this, as described in the second embodiment, since the classification is performed twice in the dispersion chamber where there is no stagnation and a high-speed swirling air flow is generated, and the classification chamber, multi-stage classification is performed with one classification device. And classification accuracy is improved.
(Aspect D)
In the aspect C, a tubular member such as the tubular member 32 protruding upward is provided at the center of the center core, and the upper end of the tubular member serves as the inlet of the dispersion chamber opening.
According to this, as described in the fourth embodiment, it is possible to cut the entry of the coarse powder into the dispersion chamber opening by the protruding amount of the tubular member, and the classification accuracy of the coarse powder during the two-stage classification is improved.
(Aspect E)
In any one of the aspects A to D, the angle of the apex angle of the isosceles triangle represented by the projection of the center core projected from the side, such as the angle α, is 100 [°] or more and 160 [°]. It is as follows.
According to this, as described in the third embodiment, by changing the angle, it is possible to adjust the speed of the swirling airflow in the dispersion chamber according to the required quality of the toner. When combined with the two-stage classification, the classification is further performed. Accuracy is improved.
(Aspect F)
In any one of the aspects A to E, a plurality of guides projecting upward from the opening and arranged circumferentially along the circular edge of the opening to guide the airflow flowing into the opening Guide vanes such as the vanes 41 are provided.
According to this, as described in the fifth embodiment, the coarse powder can be prevented from entering the opening due to the protrusion of the guide blade, and the jump of the coarse powder in the classification chamber is further reduced and the classification accuracy is improved. .
(Aspect G)
A pulverizing and classifying apparatus such as a pulverizing and classifying apparatus 200 provided with a pulverizing means such as a pulverizing apparatus 202 for pulverizing raw material of the powder to produce powder and a classifying means for selecting the powder obtained by the pulverizing means according to the size of the particles. In the apparatus, as a classification means, a classification device such as the classification device 100 according to any one of modes A to F is provided.
According to this, as described in the above embodiment, the toner after the pulverization classification process can ensure a sharp pulverization particle size distribution.
(Aspect H)
In the aspect G, the pulverizing means such as the pulverizing apparatus 202 is disposed so that the central axis overlaps with the fixed cylinder such as a cylindrical stator and the fixed cylinder inside the fixed cylinder, and is rotatable about the central axis. A mechanical crusher that crushes the material to be crushed that passes through the gap between the inner peripheral surface of the fixed cylinder and the outer peripheral surface of the rotor by rotating the rotor. is there.
According to this, as described in the above embodiment, energy saving in the pulverization process can be achieved by using the mechanical pulverizer. In addition, by using it in the pulverization classification process in the toner manufacturing method, excessive pulverization of the pulverization part is prevented in the toner pulverization classification process (fine pulverization + coarse powder closed circuit classification), and coarse particles generated by pulverization exceed the required quality Mixing in the product can be prevented. Furthermore, it is possible to realize a method for producing a toner for developing an electrostatic charge image, in which toner particles can be obtained stably and easily, and quality characteristics and production efficiency are also favorable.
(Aspect I)
In the aspect G or H, the powder as a pulverized product obtained by pulverization by the pulverization means is supplied from a collection cyclone such as the collection cyclone 203 to the classification device via the injection feeder 211 and fed to the classification device. The classified large powder such as coarse powder is returned to the pulverizing means and pulverized in a closed circuit.
According to this, as described in the sixth embodiment, the line configuration is simple and energy saving, and dispersion of the powder material proceeds to the classification device simultaneously with the conveyance by the injection feeder.
(Aspect J)
In the aspect I, a double damper such as a double damper 212 for controlling the in-machine pressure and a secondary air adjustment nozzle such as a secondary air adjustment nozzle 213 are provided between the collection cyclone and the injection feeder.
According to this, as described in the seventh embodiment, the pulsation after pulverization is eliminated, and the jump of coarse powder in the classification chamber of the classification device is further reduced, and the classification accuracy is improved.

DESCRIPTION OF SYMBOLS 1 Powder material supply pipe 1a Powder material supply port 2 Cylindrical casing 3 Center core 3b Supply hole 4 Separator core 4b Coarse powder discharge hole 5 Dispersion chamber 6 Classification chamber 7 Product powder discharge port 8 Lower hopper 9 Rectifier 9a Secondary air flow Supply flow path 10 Product powder discharge pipe 11 Lower opening 12 Louver plate section 31 Through hole 32 Tubular member 41 Guide vane 55 Ultra fine powder discharge pipe 60 Dispersion chamber rectifier 60a Dispersion chamber secondary air flow supply path 100 Classifier 101 Upper lid 101f Upper lid inner side surface 120 Dispersion chamber louver plate part 200 Crushing and classifying device 201 Raw material supply feeder 202 Crushing device 203 Collection cyclone 204 Fixed feeder 205 Classification supply injection nozzle 206 Coarse powder injection nozzle 207 Product powder collection cyclone 208 Product powder supply Feeder 209 Coarse powder collecting cyclone 211 Inji Injection feeder 212 Double damper 213 Secondary air adjustment nozzle 222 Jet mill crusher 301 Raw material supply nozzle 302 Coanda block 303 Classification edge 400 Elbow jet classification machine 500 Injection nozzle 501 Hopper 502 Nozzle section

Japanese Patent No. 2766790 JP 2009-189980 A Japanese Unexamined Patent Publication No. 2011-230048 JP 2006-055838 A Japanese Patent Laid-Open No. 04-372959 JP 2002-040702 A JP 2009-223066 A Japanese Patent No. 4065494 Japanese Patent No. 4545897 Japanese Patent No. 4646461

Claims (10)

In a cylindrical casing having a powder material supply port through which a powder material is supplied together with an air current,
Center core in order from the top,
A separator core having an opening in the center,
A dispersion chamber which is surrounded by the upper inner wall of the casing and the center core and disperses the powder material supplied together with the airflow;
In a classification device comprising: a classification chamber surrounded by the inner wall of the center core, the separator core and the casing and centrifuging powder material flowing from the dispersion chamber into fine powder and coarse powder;
In addition to the airflow that flows in along with the powder, an inflow port through which a gas that does not contain powder flows from the outside along the circumferential direction of the cylindrical inner peripheral surface of the dispersion chamber A classification device comprising a plurality of circumferentially arranged dispersion chamber swirling airflow generating means for generating a swirling airflow in the dispersion chamber when gas flows in from the inflow port. The classification device according to claim 1, wherein
A classifying apparatus, wherein an upper surface of the dispersion chamber is planar. The classification device according to claim 1 or 2,
A classifier comprising a dispersion chamber opening in communication with the inside of the opening at the center of the center core. The classification device according to claim 3,
A classifier comprising a tubular member protruding upward at the center of the center core, and an upper end of the tubular member serving as an inlet of the dispersion chamber opening. In the classification apparatus in any one of Claims 1 thru | or 4,
A classifying apparatus, wherein an apex angle of an isosceles triangle represented in a projected view of the center core projected from the side is 100 [°] or more and 160 [°] or less. In the classification apparatus in any one of Claims 1 thru | or 5,
A classification including a plurality of guide blades projecting upward from the opening and arranged circumferentially along a circular edge of the opening to guide the airflow flowing into the opening. apparatus. Pulverizing means for pulverizing the raw material of the powder to produce powder;
In a pulverizing and classifying apparatus provided with a classifying means for selecting the powder obtained by the pulverizing means according to the size of the particles,
A pulverizing and classifying apparatus comprising the classifying apparatus according to any one of claims 1 to 6 as the classifying means. The pulverizing and classifying apparatus according to claim 7,
The crushing means is
A cylindrical fixed cylinder;
A cylindrical rotor arranged inside the fixed cylinder so that a central axis overlaps the fixed cylinder and rotatable around the central axis;
A pulverizing and classifying device, wherein the pulverizing and classifying device is a mechanical pulverizer that pulverizes a material to be pulverized that passes through a gap between an inner peripheral surface of the fixed cylinder and an outer peripheral surface of the rotor as the rotor rotates. The pulverizing and classifying apparatus according to claim 7 or 8,
The powder as a pulverized product obtained by pulverization by the pulverization means is supplied from the collection cyclone to the classification device via the injection feeder,
A pulverizing and classifying device characterized in that closed-circuit pulverization is performed in which the large-diameter powder classified by the classifying device is returned to the pulverizing means and pulverized. The pulverizing and classifying apparatus according to claim 9,
A powder classifier comprising a double damper and a secondary air adjusting nozzle for controlling an in-machine pressure between the collection cyclone and the injection feeder.

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