JP6871087B2 - Dry crushing system - Google Patents

Description

The present invention relates to a dry crushing system using a media stirring type crusher, and more particularly to a dry crushing system that performs batch processing.

The crushing process using a media stirring type crusher is a process of pulverizing the powder or granular material by utilizing the shearing force or impact force generated between the crushed media to be agitated.
As the crushing medium, stainless steel, wear-resistant ceramics, or the like is used as a material, and spherical particles having a diameter of 3 to 15 mm are often used.

The crushing treatment method includes a continuous treatment method in which the processed material is continuously put into the crushing container and continuously discharged, and a treatment for a predetermined time after putting a predetermined amount of the processed material into the crushing container. There is a batch processing method.
In the continuous treatment, it is difficult to continuously perform a uniform crushing treatment because the amount of the processed material staying in the crushing chamber fluctuates. Therefore, the particle size after crushing spreads over a wide range and the particle size distribution is broad. It tends to be curved.
It is possible to obtain a product with higher uniformity by batch processing. That is, since it is easy to perform a uniform pulverization treatment on the entire processed material, the particle size after pulverization is concentrated in a relatively narrow range, and the particle size distribution becomes a sharp curve.

Patent Document 1 describes a dry media stirring type crusher that performs batch processing, and in order to perform highly uniform processing, the structure shall be such that the processed material does not accumulate at the supply port and discharge port of the processed material. Is required, and effective supply and discharge valves for this purpose are described.
In principle, the crushing process is performed with the rotating shaft positioned horizontally, but in order to remove the deposits in the crushing container, the rotating shaft is tilted once or twice during the crushing process for a short time. It is described as rotating as.

However, as the range of processed products to be pulverized has expanded, more difficult processed products have appeared. That is, when the same batch processing is repeatedly performed on the same processed material, the particle size distribution may not be constant but fluctuate, resulting in a broad curve.
It was found that many examples of processed products are found in plant-based processed products such as tea, Chinese herbs, and roasted coffee. Furthermore, it was clarified that the components such as water and oil slightly fluctuate in these treated products, and that the adhesiveness to the crushing container fluctuates due to this.

Further, when the same pulverization treatment is performed on metal powder or metal oxide, alloying (mechanical alloying treatment) or chemical reaction (mechanochemical treatment) is possible by repeating crushing and pressure welding. Even in this case, the particle size distribution may fluctuate.

Japanese Unexamined Patent Publication No. 2016-129866

An object of the present invention is a dry crushing system that performs batch processing, for processed products such as tea, Chinese herbs, roasted coffee beans, or processed products of metal powder or metal oxide, which are eaten by humans. The purpose is to provide an optimal grinding system.
That is, it is to provide a system that can obtain a sharp particle size distribution for a processed material having adhesiveness, and even if the component ratio such as moisture fluctuates while repeating the same batch processing many times. An object of the present invention is to provide a grinding system capable of always obtaining a sharp particle size distribution.

The present invention is a dry crushing system that performs batch processing, in which a media stirring type crusher including a stirring member that rotates with a rotating shaft inserted from one end wall inside a horizontal crushing container and the rotating shaft are combined. The media stirring type crusher has a setting function including a driving unit for driving and a control unit for controlling the rotation of the driving unit, and the control unit can input at least an alternation time in the rotation direction of the rotating shaft. A measurement function for grasping the operating state and an output function for instructing the driving unit to change the rotation direction of the rotating shaft based on the change time input by the setting function or the operating state grasped by the measurement function. It is characterized by having.

The measurement function measures the internal temperature of the crushing container, and when the measured value of the internal temperature measures an abnormal value, the drive unit is given priority over the change time to change the rotation direction of the rotation shaft. It is preferable to indicate.
Further, the measurement function measures the power in the drive unit, and when the measured value of the power measures an abnormal value, the drive unit is given priority over the change time to change the rotation direction of the rotation shaft. It is preferable to indicate.

The grinding system of the present invention can completely treat the entire processed product and leave no untreated portion, so that a sharp particle size distribution can be obtained. Then, even when the adhesiveness of the processed product changes, the same particle size distribution can always be obtained.
Further, by measuring the temperature and power, it is possible to grasp the characteristics of each processed material, and it is possible to perform the optimum processing for each.

It is a schematic block diagram which shows an example of the dry pulverization system of this invention. It is explanatory drawing for demonstrating adhesion in a crushing container. It is a schematic flow chart which shows the flow of processing in a control part.

The present inventors have conducted diligent research on the problem that the particle size distribution is not constant even when the same batch processing is repeatedly performed on the same processed material.
As a result, it was clarified that the adhesiveness changes due to a slight change in the components of the processed product, which causes the particle size distribution to change.

In order to solve this problem, as a result of repeated research on the behavior of the crushed media and the processed material using a crushed container made of transparent resin, it is necessary to understand the adhesion conditions when the processed material adheres to the wall surface of the container. Was made. In addition, it was possible to grasp the removal conditions when the processed material once adhered to the wall surface is removed from the wall surface.
Then, in the middle of one batch processing, it is possible to remove the processed material adhering to the wall surface from the wall surface by changing the rotation direction of the stirring member several times, and by repeating this operation. , It has become possible to always obtain a sharp particle size distribution.

The reason why a sharp particle size distribution can be obtained by changing the rotation direction of the stirring member is as follows.
a) Adhesive treated material adheres to a specific place in the crushing container and grows over time.
b) Since the portion that adheres and grows in the crushing container is not subjected to the crushing treatment thereafter, the treated product as a whole exhibits a broad particle size distribution.
c) By changing the rotation direction of the stirring member, it is possible to remove the processed material in the adhered / grown portion. Then, the removed processed product is immediately subjected to a pulverization treatment.
d) By changing the direction of rotation, the processed material adheres to a new specific place and grows, but as long as the change is repeated, there is no portion that continues to adhere for a long time.
e) Therefore, even if it is an adhesive treated product, it is possible to always perform a uniform pulverization treatment in the same manner as a treated product that does not adhere at all.

FIG. 1 is a schematic configuration diagram showing a dry pulverization system 10 which is an example of the present invention.
The dry crushing system 10 is a crushing system that performs batch processing dry crushing by a media stirring type crusher 20.
Wet pulverization is pulverization in a slurry state in which solids are suspended in a liquid, whereas dry pulverization is a pulverization process in which solid particles are pulverized in that state. Even when the solid particles contain a liquid such as adhering water, they are referred to as dry pulverization unless they are in a slurry state.

The media stirring type crusher 20 includes a stirring member 23 composed of a plurality of stirring rods in which a rotating shaft 22 is inserted from one side wall into a horizontal cylindrical crushing container 21 and rotates together with the rotating shaft 22. ..
A crushing medium and solid particles to be processed are put into the inside of the crushing container 21, and the stirring member 23 is rotated together with the rotating shaft 22 to stir the inside of the crushing container 21 for a predetermined time.
By this stirring, a shearing force or an impact force is generated between the pulverized media, and the processed product can be miniaturized.

The media stirring type crusher 20 is provided with a jacket 25 on the peripheral wall of the crushing container 21, and constitutes a cooling unit that cools the inside of the crushing container 21 by the flow of a cooling medium. This is to prevent the temperature of the processed material or the like from rising due to the consumed stirring power.
The cooling medium is introduced into the jacket 25 from the inlet line 91 and discharged from the outlet line 92.

In the dry crushing system 10 of the present invention, even if the processed material has adhesiveness, in order to avoid adhering to the wall surface for a long time, the rotation direction of the rotating shaft 22 is changed several times during one batch processing. It is characterized by taking turns driving.
The processed material adhering to the wall surface becomes a portion that is not subjected to the crushing treatment, and there is a high possibility that the processed material will be an untreated product until the end. However, when the rotation direction of the rotating shaft 22 is changed, the adhering processed material is removed from the wall surface, so that the processed material is subjected to the crushing treatment again, and as a result, the entire processed material is always uniformly crushed. In response, a sharp particle size distribution can be obtained.

In order to perform such processing, the dry crushing system 10 includes a drive unit 60 that drives the rotating shaft 22 and a control unit 50 that controls the rotation of the drive unit 60.
The drive unit 60 is a circuit that drives the electric motor 31 using the electric power from the primary side power supply 30, and the inside of the crushing container 21 can be set to the optimum stirring state according to the instruction of the control unit 50.
In order to change the rotation direction of the rotating shaft 22 and to freely select the number of rotations, the AC power from the temporary power supply 30 is once converted to DC by the rectifier, and then the AC is again suitable for stirring by the inverter. The configuration is preferable.

The control unit 50 has a setting function for the operator to input a set value such as a change time, a measurement function for grasping the operating state of the media stirring type crusher 20, and an output for instructing the drive unit 60 to change the rotation direction. It has a function.
The setting function is a function in which the operator sets a set value by the input signal 51.
For example, the processing time D1 for performing one batch processing and the shift time D2 for which the maximum value of the time for the rotation shaft 22 to rotate in the same direction can be input can be set as a set value.

The measurement function is a function of grasping the operating state of the media stirring type crusher 20.
That is, the total elapsed time M1 which is the processing time after starting the batch operation and the partial elapsed time M2 due to rotation in the same direction can be input as measured values.
Further, a temperature signal 55 for measuring and inputting the internal temperature of the crushing container 21 is provided, and a power signal 56 for measuring and inputting the power consumed by the drive unit 60 is provided.
For these measured values, the set value for each measured value can be set by the input signal 51.

The output function is a function of instructing the drive unit 60 to drive the rotating shaft 22.
That is, the operation signal 52 can be emitted to instruct the start and stop of the rotating shaft 22, and the alternation signal 53 can be emitted to instruct the alternation in the rotation direction.
The operation signal 52 is issued when the start button is pressed to start the operation, or when the total elapsed time M1 reaches the processing time D1 and the batch processing is completed.

The shift signal 53 is issued not only when the partial elapsed time M2 reaches the shift time D2 in the middle of processing, but also when an abnormal value is measured in the measured values such as temperature and power in the dry crushing system 10. Regardless of the value of the partial elapsed time M2, the control unit 50 can instruct the drive unit 60 to give priority to the change of the rotation direction of the rotation shaft 22.

For example, when the temperature inside the crushing container 21 is measured, the internal temperature rises due to the heat of stirring by driving the electric motor 31, but it becomes substantially constant in equilibrium with the amount of heat of cooling by the cooling medium.
When the processed material adheres to the inner wall of the crushing container 21, heat transfer to the cooling medium deteriorates and the temperature inside the crushing container 21 rises. Therefore, this is detected and the rotation direction is changed with respect to the drive unit 60. Can be instructed.

Further, the power consumption of the drive unit 60 when stirring the pulverized media and the processed material by the rotation of the stirring member 23 sharply increases at the start of driving of the electric motor 31 to show a maximum value, and then settles at a constant value. And the steady value will be continued. When the processed material adheres and accumulates on the inner wall of the crushing container 21 in this steady state, the power consumption increases or decreases, so that this fluctuation can be detected and the drive unit 60 can be instructed to change the rotation direction.

Next, the behavior of the crushed media and the processed material in the crushing container 21 will be described with reference to FIG. 2, and the adhesion of the processed material will be described.
FIG. 2 shows a circular view which is a schematic cross-sectional view of the inside of the media stirring type crusher 20 in the direction of the rotating shaft 22, and a longitudinal view which is a schematic cross-sectional view taken along the line AA of this figure.
By forming the crushing container 21 with a transparent resin and observing the behavior of the crushed medium and the processed material, it has become possible to grasp and solve the essence of the problem of the present invention.

The direction of rotation of the rotating shaft 22 is referred to as clockwise in the direction indicated by the arrow in the circular diagram and counterclockwise in the opposite direction. Then, the circumferential position of the crushing container 21 is indicated by the hands of the clock, and the uppermost part is called the 0 o'clock position, the right side is called the 3 o'clock position, the lowermost part is called the 6 o'clock position, the left side is called the 9 o'clock position, and the like. To do.
Further, in the longitudinal view, the portion through which the tip of the stirring member 23 passes is referred to as a passing position x, and the middle of the two passing positions x is referred to as an intermediate position y.

When the crushing container 21 is filled with the crushing media, the filling amount is set to be slightly higher than the axis of the rotating shaft 22. That is, the upper surface is set to have a height from 2:30 to 9:30.
Since the particle size of the processed material to be charged is usually smaller than that of the pulverized media, the position of the upper surface hardly changes even after the processed material is charged.

In the circular view, when the stirring member 23 rotates in the clockwise direction, the upper surface of the crushing medium and the processed material descends to the position of 3:00 to 3:30 on the right side and rises to the position of 3:00 to 3:30 on the left side from 10:00 to 10 It will be at the time of 30 minutes.
Then, as the rotation becomes faster, the crushed media and the processed material move from the left side to the right side in the upper space. The moving direction of the crushed media is relatively random, and as the rotation speed increases, the moving state gradually becomes more intense.

Thus, in the circular view, the crushed media scraped up on one side appears to be thrown into the other side.
Therefore, the left side in the clockwise direction is referred to as the scraping side, the right side is referred to as the throwing side, the right side in the counterclockwise direction is referred to as the scraping side, and the left side is referred to as the throwing side.

In the longitudinal view, the movement of the crushed media is different between the scraping side and the throwing side, and is different between the passing position x and the intermediate position y.
On the scraping side, the movement of the crushed media is clearly different between the passing position x and the intermediate position y, the movement is violent at the passing position x, and the movement is slow at the intermediate position y.
Further, on the throwing side, although there is a difference in movement between the passing position x and the intermediate position y, the difference is small and the movement is random as a whole.

Focusing on the movement of the processed material, on the scraping side, the processed material tends to move from the passing position x where the movement of the crushed media is intense to the intermediate position y where the movement is small, and tends to gather near the wall surface at the intermediate position y. There is. Then, with the passage of time, the processed material tends to adhere to the wall surface at the intermediate position y and gradually grow larger.
On the other hand, it was found that on the throwing side, since the crushed media moves as a whole, the processed material tends to move with it, and it does not adhere to either the passing position x or the intermediate position y.

Next, when the rotation direction of the rotating shaft 22 is changed while the processed material is adhered and grown on the scraping side, the rotation is counterclockwise, the right side is the scraping side, and the left side is the throwing side. ..
Then, on the left side, which was the throwing side, it was confirmed that the processed material adhering to the wall surface was gradually removed by the movement of the crushing media that was totally random.
At the same time, on the right side on the scraping side, it was confirmed that the processed material moved from the passing position x toward the intermediate position y, adhered to the wall surface, and gradually grew.

That is, on the scraping side, the processed material has an action of adhering and growing.
On the scraping side, the movement of the crushed media differs between the passing position x and the intermediate position y, and the processed material moves from the passing position x where the movement is intense to the intermediate position y where the movement is slow, and adheres and grows at the intermediate position y. is there.

On the other hand, on the throwing side, not only does the processed material not adhere, but it also has the effect of removing the adhered processed material.
Since the crushed media is randomly thrown, the movement near the wall surface is also random, and the processed material does not move or adhere to a specific place. Furthermore, the random movement can remove the processed material adhering to the wall surface.

Therefore, by changing the rotation direction of the stirring member 23, the deposits are removed on the wall surface on the throwing side.
That is, during the crushing process, adhesion always occurs on the crushing container, but it can be removed by replacing the stirring member 23.
Therefore, the processed product is processed uniformly as a whole, and can be a product having a sharp particle size distribution.

Next, an example of processing in the control unit 50 will be described with reference to FIG.
In step S01, before the start of operation, the operator sends an input signal 51 to the control unit 50 to input the operation conditions. For example, the processing time D1 in one batch processing and the shift time D2 as the maximum value at which the rotation shaft 22 can rotate in the same direction are input and set as set values.
Further, if necessary, a limit value or the like can be set as a set value with respect to the measured value such as the internal temperature of the crushing container.

In step S02, the measured values total elapsed time M1 and partial elapsed time M2 are initialized to 0 values, and in step S03, the start of the process of starting the media stirring type crusher 20 is awaited. It becomes a state.

In step S03, when the operator presses the start button, the process of step S04 is started, and in step S05, the measurement of the total elapsed time M1 and the partial elapsed time M2 is started.
Then, in step S06, the partial elapsed time M2 waits to reach the shift time D2, and in step S09, the total elapsed time M1 waits to reach the processing time D1.

When the partial elapsed time M2 reaches the change time D2 in step S06, the change in the rotation direction is instructed in step S10, the partial elapsed time M2 is once initialized in step S11, and then the partial elapsed time is again in step S12. Start measuring M2.
The abnormality 1 in step S07 is, for example, the case where the internal temperature of the crushing container 21 rises, and the abnormality 2 in step S08 is, for example, the case where the power consumption fluctuates.
Even in these abnormalities, steps S10 to S12 are executed in the same manner as in step S06. That is, when there is an abnormality, the rotation direction is changed with priority over the partial elapsed time M2.

Further, when the total elapsed time M1 reaches the processing time D1 in step S09, the rotation of the rotation shaft 22 is stopped in step S13 to end one batch processing.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and the design change to the extent that the gist of the present invention is not deviated is the present invention. include.
For example, a system capable of setting or changing the rotation speed may be provided so that the operation of changing the rotation speed of the stirring member 23 can be performed during the process.

10 Dry crushing system 20 Media stirring type crushing machine 21 Crushing container 22 Rotating shaft 23 Stirring member 30 Primary side power supply 50 Control unit 60 Drive unit

Claims (3)

A dry crushing system that performs batch processing
A media stirring type crusher including a stirring member that rotates with a rotating shaft inserted from one end wall inside a horizontal crushing container, a driving unit that drives the rotating shaft, and a control that controls the rotation of the driving unit. With a part,
The control unit has a setting function capable of inputting at least the change time in the rotation direction of the rotation shaft, a measurement function for grasping the operating state of the media stirring type crusher, and the change time or the change time input by the setting function. A dry crushing system characterized in that the drive unit is provided with an output function for instructing a change in the rotation direction of the rotation shaft based on the operation state grasped by the measurement function. When the measurement function measures the internal temperature of the crushing container and the measured value of the internal temperature measures an abnormal value, the drive unit is given priority over the change time to change the rotation direction of the rotation shaft. dry grinding system according to claim 1, wherein the instructing. When the measurement function measures the power in the drive unit and the measured value of the power measures an abnormal value, the measurement function instructs the drive unit to change the rotation direction of the rotation shaft in preference to the change time. The dry grinding system according to claim 1 or 2.

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