JP2002320870A - Pulverization process and pulverization system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulverization process appropriately used for pulverizing a material to be pulverized which is liable to be affected by heat generated in the pulverization, and also to provide a pulverization system that is an embodiment of the process. SOLUTION: A mechanical pulverizer used in this pulverization process is provided with: a cylindrical rotor having many grooves each of which is formed on the outer peripheral surface of the rotor and has a prescribed shape; and a liner that is stationarily placed outside the rotor while interposing a prescribed space between the outer peripheral surface of the rotor and the inner peripheral surface of the liner, and has many grooves each of which is formed on the inner peripheral surface of the liner and has a prescribed shape; wherein a material to be pulverized is subjected to pulverization treatment in the space between the outer peripheral surface of the rotor and the inner peripheral surface of the liner. The pulverization method using the mechanical pulverizer involves adjusting the temperature of air for conveying the to-be-ground material, at the inlet of the mechanical pulverizer, at -10 deg.C or below, or preferably, at -10 to -40 deg.C. This pulverization system is an embodiment of the process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulverizing method and a pulverizing system using the same, and more particularly to a pulverizing method which can be suitably used for pulverizing an object to be pulverized which is affected by heat generated during pulverization. In particular, the present invention relates to a pulverization method capable of suppressing power required for pulverization, and a pulverization system using the method.

[0002]

2. Description of the Related Art For example, fine powders such as resin powder constituting toner used for developing an electrostatic latent image in a copying machine or the like are used for various purposes. This resin fine powder has a particle size of about 5 to 8 μm. In order to obtain a fine powder having such a fine particle size, a high-speed rotating mechanical pulverizer is generally used. In this high-speed rotating mechanical pulverizer, a large amount of heat is generated at the time of pulverization because a large shear force acts on the object to be pulverized.

[0003] Therefore, for example, when crushing an object to be crushed, such as the above-mentioned resin, which is softened by heat or further melted, it is necessary to use a raw material in order to avoid such an effect. The problem is that the total amount of heat generated is reduced by lowering the amount of resin supplied, and this also reduces the amount of heat generated, but by reducing the number of revolutions of the crusher, the crushing speed (production amount) must be reduced. was there. However, reducing the grinding speed directly leads to a reduction in the production volume, and must be avoided as much as possible.

[0004] In order to solve such a problem, there have been proposed several improvements such as a technique disclosed in Japanese Patent Application Laid-Open No. 7-313896. JP-A-7
The technology disclosed in Japanese Patent No. 313896 discloses a method of efficiently removing heat generated during pulverization and introducing a coarse powder resin into an atmosphere in which liquid carbon dioxide is injected in order to enable production of a fine resin powder. Then, the resin is mixed with dry ice solidified by spraying, and the mixture is pulverized to pulverize the resin.

That is, according to the technique disclosed in the above-mentioned Japanese Patent Application Laid-Open No. Hei 7-313896, a mixture of resin and solidified dry ice is supplied to a pulverizer to suppress a rise in the temperature of the resin during pulverization. Not only that, but also in the step of pulverizing the mixture, the dry ice serves as an auxiliary for pulverizing the resin, so that the pulverization efficiency is improved (however, this mechanism is not always clear).

[0006]

By the way, the method described in the above-mentioned publication, in which liquid carbon dioxide is always sprayed on the raw material during pulverization, is environmentally friendly in that a large amount of carbon dioxide to be finally removed is used. It should include new problems, such as problems or cost problems, and it cannot be denied that it is not necessarily a fundamental solution to the problem.

As a result of intensive research, the present inventor has found that, without using a new medium such as liquid carbon dioxide in the above technology, the present invention is suitable for pulverizing an object to be pulverized which is affected by heat generated during pulverization. A pulverization method that can be used, in particular, a pulverization method capable of suppressing the power required for pulverization, and a pulverization system using this method have been successfully developed, and the present application has been completed.

More specifically, the present invention solves the above-mentioned problems and solves the problem of the object to be pulverized which is affected by heat generated during pulverization, in other words, the processing temperature measured at the outlet of the pulverizer. It is an object of the present invention to provide a pulverization method which can be suitably used for pulverization of an object to be pulverized to which certain restrictions are imposed, and another object is to provide a pulverization system embodying the pulverization method. It is in the thing.

[0009]

In order to achieve the above object, a pulverizing method according to the present invention comprises: a cylindrical rotor having a plurality of grooves of a predetermined shape formed on an outer peripheral surface; A liner having a fixed number of grooves formed in an inner peripheral surface thereof, the liner being fixedly disposed at a predetermined interval from an outer peripheral surface of the rotor; In a pulverization method using a mechanical pulverizer for pulverizing an object to be pulverized with a peripheral surface, the temperature of the air to be pulverized at the entrance of the mechanical pulverizer is set to -10 ° C
It is characterized as follows.

Further, in the pulverizing method according to the present invention, the temperature of the air to be pulverized at the entrance of the mechanical pulverizer may be set to -40.
C. or higher. Furthermore, in the pulverization method according to the present invention, the temperature of the air to be pulverized at the entrance of the mechanical pulverizer is determined according to the regulated temperature when the processing temperature of the pulverized substance is regulated in advance. It is characterized by the following.

In the pulverizing method according to the present invention,
The pre-regulated processing temperature of the crushed object is a temperature measured at an outlet portion of the crushed object of the crusher. Further, at the time of the pulverizing treatment, a cool air at a predetermined temperature is supplied, and dehumidified air is used as the cool air.

On the other hand, a pulverizing system according to the present invention comprises a cylindrical rotor having a plurality of grooves of a predetermined shape formed on an outer peripheral surface thereof, and a predetermined distance from the outer peripheral surface of the rotor outside the rotor. And a liner in which a number of grooves of a predetermined shape are formed on the inner peripheral surface of the rotor, and the object to be ground is crushed between the outer peripheral surface of the rotor and the inner peripheral surface of the liner. A pulverizing system using a mechanical pulverizer for processing, characterized in that the pulverized material supply unit of the pulverizer is provided with a cool air device for supplying cool air at a predetermined temperature.

Further, the pulverizing system according to the present invention further comprises a classifier for classifying the pulverized product discharged from the pulverizer outlet in addition to the above-mentioned pulverizing system. Coarse powder larger than the desired particle size
A return path for supplying the powder to the crusher again is provided.

The material to be pulverized to be applied to the pulverization method according to the present invention or the material to be pulverized to be suitably applied to the pulverization system according to the present invention is the same as the above-mentioned toner raw material for a copying machine. Examples thereof include thermoplastic resins and various foods that tend to lose flavor when heated to a high temperature. However, it goes without saying that the present invention is not limited to these.

[0015]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a diagram showing a schematic configuration of a pulverizing system according to a first embodiment of the present invention. In the figure, 1
Reference numeral 0 denotes a cylindrical rotor having a large number of grooves of a predetermined shape formed on the outer peripheral surface thereof, and is disposed outside the rotor at a predetermined interval from the outer peripheral surface of the rotor. A mechanical pulverizer (hereinafter, referred to as a pulverizer) for pulverizing an object to be pulverized between an outer peripheral surface of the rotor and an inner peripheral surface of the liner; , Simply referred to as a crusher).

Reference numeral 12 denotes a cool air device for supplying dehumidified cold air to the crusher 10, reference numeral 14 denotes a raw material supply device for supplying the crusher 10 with a material to be crushed (hereinafter referred to as raw material),
Reference numeral 16 denotes a cyclone for recovering the raw material after the pulverization process from the pulverizer 10, reference numeral 18 denotes a bag filter for recovering fine raw material pulverized substances contained in exhaust gas from the cyclone 16, and reference numeral 20 denotes the entire system. Shows a blower that exhausts air. B indicates a valve.

Each of the above-described components is substantially the same as a single device as a single device. The feature of the pulverizing system according to the present embodiment is that, after combining these devices (components) as shown in FIG.
The point is that the temperature of the supply air to zero is controlled within a predetermined temperature range.

That is, according to the experiment of the present inventor, according to the pulverizer 10 having the above-described structure, a raw material which is affected by heat generated at the time of pulverization, for example, a raw material of a toner used in a copying machine or the like. When resin powder or tea leaves are powdered or buckwheat flour is made, the maximum processing capacity of the crushed product is limited by the temperature rise of the product.
For example, it has been found that the relationship is as shown in FIG.

Generally, if the amount of raw material supplied to the crusher 10 is increased in order to increase the processing capacity, that is, the production amount, the load on the crusher 10 is increased. In addition, the temperature at the time of finishing the obtained product also increases. This is not preferable because it leads to a decrease in crushing efficiency due to the softening of the raw material and a deterioration in quality due to a rise in temperature. Naturally, restrictions are set for each product.

On the other hand, as described above, the pulverizer 1
Although a method of cooling 0 itself has also been proposed, this method has limitations and significant improvement cannot be expected. Therefore, the present inventor has paid attention to the point that the temperature of the air supplied to the crusher 10 is reduced. FIG. 2 is a graph showing the relationship between the temperature of the air supplied to the crusher 10 and the maximum processing capacity at that time in this case.

Just from the results shown in the graph of FIG. 2, it is efficient to supply cold air at the lowest possible temperature when supplying raw materials during the pulverizing process using the pulverizer 10. In practice, however, it is not sufficient to simply supply low-temperature cold air. Hereinafter, this point will be supplementarily described based on experimental results by the present inventors.

As described above, the crusher 10
When the crushing process is performed by using the crusher, in addition to the operating energy of the crusher 10 itself, energy for producing and supplying the cold air and exhaust (blower) energy corresponding to the supplied air volume are required. FIG. 3 is a graph showing the values of the sum of these energies required for processing the material to be ground per unit weight at various cold air temperatures.

According to the graph of FIG. 3, it can be seen that the value of the above-mentioned total energy decreases as the temperature of the supplied cool air is reduced. From this, one conclusion can be drawn that the temperature of the cold air to be supplied is preferably −10 ° C. or less. However, the lower the temperature of the cold air, the more effective it is. This is a problem with the energy used.

As a result of examining this point, when the temperature of the cold air is greatly reduced to -40 ° C. or less, the required energy may be significantly increased as compared with the rate of increase of the energy up to that time. At the same time, it has been found that the use of cold air of −40 ° C. or less is not advisable because disadvantages come to the surface with respect to secondary factors such as the necessity of increasing the size of the cool air device itself. Was.

Based on these circumstances, the present inventor supplies cold air at a predetermined temperature to the above-described pulverizing method and a pulverizing system using the pulverizing method, that is, a pulverized material supply section of the pulverizer. This has led to the proposal of a pulverizing method characterized in that the pulverizing method is performed, and a pulverizing system including a cool air device for the pulverizing method.

Returning to FIG. 1, the operation of the pulverizing system according to this embodiment will be described. In the pulverizing system according to the present embodiment, air cooled to, for example, −20 ° C. is supplied from the cold air device 12 to a raw material supply port that supplies the raw material into the pulverizer 10, and the supply amount is reduced by the blower 20. The pulverization by the pulverizer 10 is performed in a state where substantially the same amount of air is exhausted.

The temperature rise of the raw material during the pulverizing process is monitored by a temperature sensor provided at the outlet of the pulverizer 10. Under this condition, the temperature reached by the raw material during the pulverizing process is naturally set in advance. It goes without saying that the temperature is lower than the predetermined temperature. In addition, this condition is also a condition under which the crusher 10 can be continuously operated for a relatively long time by supplying dehumidified cool air from the cool air device 12.

According to the above-described embodiment, the object to be pulverized that is affected by the heat generated during the pulverization, that is, the processing temperature at which the object to be pulverized can reach during the pulverization, is subject to a certain restriction. An effect is obtained that a pulverizing system that can be suitably used for pulverizing an object can be realized.

FIG. 4 is a diagram showing a schematic configuration of a pulverizing system according to another embodiment of the present invention. As is clear from the figure, the difference between the pulverizing system according to the present embodiment and the pulverizing system according to the embodiment shown in FIG. 1 is that the latter is an open system, whereas the former is an open system.
The pulverization system according to the present embodiment) is a closed system for handling raw materials.

That is, in the pulverizing system according to the embodiment shown in FIG. 4, by adding a classifier 22 to the configuration of the pulverizing system according to the embodiment shown in FIG. The intermediate product) is classified, and if it exceeds a predetermined particle size, it is returned to the pulverizer 10 and the pulverization process is performed again.

More specifically, the raw material initially supplied is pulverized by the pulverizer 10 while being supplied with cold air at a predetermined temperature, and the resulting intermediate product is separated by the cyclone 16, It is sent to the classifier 22. In the classifier 22, only those having a predetermined particle size or less are collected as products, while those having a predetermined particle size are returned to the pulverizer 10 (path indicated as coarse powder return in the figure). Again, the pulverizing process by the pulverizer 10 is performed.

In the pulverizing system according to the present embodiment, such processing is repeated to efficiently
The effect is obtained that it is possible to produce a powder raw material having a desired particle size. Here, when it is necessary to improve the production amount of the product to some extent, it is possible to achieve this object by lowering the temperature of the cool air supplied by the cool air device 12 as necessary.

Examples of the raw material to be subjected to the pulverization process applicable to the pulverization method according to the present invention include a resin as a raw material of the above-mentioned toner for a copying machine and various foods. In the case of the former, in recent years, corresponding to copiers that are becoming faster and faster, fixing and the like can be performed in a short time, so to say, a point suitable for crushing easily softening resin is used. Utilizes the fact that treatment at a low temperature does not impair the flavor and the like.

Each of the above embodiments is merely an example of the present invention, and the present invention is not limited to these embodiments, and may be modified or improved within the scope of the present invention. Needless to say, it is good.

[0036]

As described above in detail, according to the present invention, a pulverizing method which can be preferably used for pulverizing an object to be pulverized which is affected by heat generated during pulverization, and this pulverizing method have been embodied. This has a remarkable effect that a crushing system can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a pulverizing system according to a first embodiment of the present invention.

FIG. 2 is a graph showing the relationship between the temperature of cold air supplied to a crusher and the crushing capacity.

FIG. 3 is a graph showing a relationship between a temperature of cold air supplied to a crusher and a total power of a crushing system.

FIG. 4 is a diagram illustrating a schematic configuration of a pulverizing system according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Mechanical crusher 12 Cold air device 14 Raw material feeder 16 Cyclone 18 Bag filter 20 Blower 22 Classifier

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B02C 23/12 B02C 23/12 23/24 23/24 (72) Inventor Kazumi Ozawa Iruma County Univ., Saitama 5-3-1 Imachi Tsurugaoka Nisshin Flour Milling Co., Ltd. Production Technology Laboratory (72) Inventor Kenzo Kokubo 5-3-1 Tsurugaoka Oi-machi Iruma-gun, Saitama Prefecture Nisshin Flour Milling Co., Ltd. F term (reference) 4D063 FF14 FF21 FF37 GA03 GA10 GC01 GC12 GC16 GC29 GC32 GD01 GD22 GD24 4D065 AA07 BB01 BB11 EB07 EB14 EB20 ED01 ED15 ED21 ED32 ED35 EE01 EE18 EE19 4D067 EE12 EE12 EE12

Claims (7)

[Claims] 1. A cylindrical rotor having a plurality of grooves of a predetermined shape formed on an outer peripheral surface thereof, and fixedly disposed outside the rotor at a predetermined interval from the outer peripheral surface of the rotor. A liner having a plurality of grooves of a predetermined shape is formed on an inner peripheral surface thereof, and a mechanical crusher for crushing an object to be crushed between an outer peripheral surface of the rotor and an inner peripheral surface of the liner is used. In the pulverization method, the temperature of the air to be pulverized at the entrance of the mechanical pulverizer is set to −10 ° C. or less. 2. The pulverization method according to claim 1, wherein the temperature of the air to be pulverized at the entrance of the mechanical pulverizer is -40 ° C. or higher. 3. The temperature of the conveying air of the object to be ground at the entrance of the mechanical pulverizer is determined according to the regulated temperature when the processing temperature of the object to be ground is regulated in advance. The pulverization method according to claim 1 or 2, wherein 4. The pre-regulated processing temperature of the object to be crushed is a temperature measured at the outlet of the crushed object of the mechanical crusher.
Pulverization method described in 1. 5. The crushing process according to claim 1, wherein cool air of a predetermined temperature is supplied, and dehumidified air is used as the cool air. Pulverization method described in 1. 6. A cylindrical rotor having a plurality of grooves of a predetermined shape formed on an outer peripheral surface thereof, and fixedly disposed outside the rotor at a predetermined interval from the outer peripheral surface of the rotor. A liner having a plurality of grooves of a predetermined shape is formed on an inner peripheral surface thereof, and a mechanical crusher for crushing an object to be crushed between an outer peripheral surface of the rotor and an inner peripheral surface of the liner is used. A crushing system, comprising: a chiller for supplying a chilled air at a predetermined temperature to a crushed material supply unit of the crusher. 7. The pulverizing system according to claim 6, further comprising a classifier for classifying a pulverized product discharged from an outlet of the pulverizer, and a desired classifier classified by the classifier. A pulverizing system comprising a return path for supplying coarse powder having a particle size larger than the particle size to the pulverizer again.