JP4889345B2 - Operation method of airflow crusher - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air stream type crusher preventing a material from being jetted from a casing on starting of operation and preventing a particle not sufficiently crushed from bing mixed into a fine particle product on stopping of operation. <P>SOLUTION: In the air stream type crusher 1 in which a first rotation impeller 32 and a second rotation impeller 33 are rotated in a casing 10 to perform crushing and classification of the thrown material, a material throwing passage 21 for throwing the material to a swirl area R, an air introduction passage 26 for introducing air to the swirl area R, an air introduction passage 27 for introducing air to the front side of a classification area S, a ring-like passage 28 and a clearance 50, an opening/closing valve 29 of the air introduction passage 26 and an opening/closing valve 30 of the air introduction passage 27 are provided. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to an airflow pulverizer used for pulverizing various raw materials such as agricultural products and minerals, and an operating method of the airflow pulverizer.

  Conventionally, an airflow type pulverizer is used to pulverize various raw materials such as agricultural products and minerals (see, for example, Patent Document 1). As shown in FIG. 4, the casing 10 of the airflow type pulverizer 1 is composed of a charging side casing 11, a center casing 12, and a discharging side casing 13. A first rotary blade 32 and a second rotary blade 33 are attached to a front end (left end in the figure) of the shaft 17 that passes through the input side casing 11 in the casing 10 and spaced apart from each other by a predetermined distance. The shaft 17 is rotatably supported by a frame 18 via a bearing, and is configured to rotate by a motor (not shown).

As shown in FIGS. 4 and 5, the tapered wall 41 and the hanging wall 43 are formed inside the charging side casing 11, and the diameter of the tapered wall 41 gradually decreases toward the rear, and the hanging wall 43 becomes the tapered wall 41. It is perpendicular to the shaft 17 at the rear end. A space between the first rotary blade 32 and the hanging wall 43 forms a swirl region R.
A charging passage 22 is formed in the charging casing 11 in a direction perpendicular to the shaft 17. The upper end inlet of the charging passage 22 is connected to the hopper 23, and the lower end outlet opens to the tapered wall 41, so that the raw material is introduced into the swirl region R from the charging passage 22 and air is introduced.

The center casing 12 has a cylindrical shape, and the space between the first rotary blade 32 and the second rotary blade 33 forms a grinding region C.
A tapered wall 42 is formed inside the discharge-side casing 13, and the diameter of the taper wall 42 gradually decreases toward the front, and a discharge port 46 opens at the front end of the discharge-side casing 13. A suction fan (not shown) is connected to the discharge port 46 via a recovery pipe 47.

A gap 50 is formed in front of the classification area S, which will be described later, and between the discharge port 46 and the rear end of the collection pipe 47, and air is introduced into the collection pipe 47 from the gap 50. ing.
The first rotating blade 32 and the second rotating blade 33 are provided with a plurality of blades 36 and 38 radially around the bosses 34 and 35, and rotate by the rotation of the shaft 17, and the airflow swirling in the casing 10 is generated. It has a configuration that occurs. Note that the blades 36 of the first rotary blade 32 impart a swirl force to the airflow generated in the swirl region R and also a forward thrust to facilitate introduction of the raw material from the swirl region R to the pulverization region C. It has a possible shape.

An inclined surface 38 is formed at the tip of the blade 37 of the second rotary blade 33, and the inclined surface 38 faces the tapered wall 42 of the discharge-side casing 13. A space between the second rotary blade 33 and the discharge-side casing 13 and a space along the tapered wall 42 in front of the space form a classification region S.
The raw material charged into the swirl region R from the charging passage 22 swirls on the airflow swirling in the swirl region R, and flows radially outward by centrifugal force. Further, the suction fan sucks the air in the casing 10 toward the discharge port 46, and a differential pressure is generated between the swirl region R and the pulverization region C.

  The raw material swirling in the swirl region R enters between the blades 36 of the first rotating blade 32 and enters the pulverizing region C by this differential pressure and the forward thrust of the air flow generated by the first rotating blade 32. In the pulverization region C, the larger the particle diameter, the larger the centrifugal force acts, and the higher the peripheral speed gathers on the radially outer peripheral side, and the pulverization occurs mainly due to the grinding between the particles and also due to the collision between the particles. Is done. At this time, the second rotary blade 33 blocks the raw material in the pulverization region C from moving to the classification region S. This blocking action is generated by an airflow curtain formed on the surface of the second rotary blade 33.

Among the raw materials pulverized in the pulverization region C, particles having a smaller particle diameter and smaller mass gather in the vicinity of the rotation center of the second rotary blade 33 having a lower pressure, and are sucked by the suction fan as fine powder, and are discharged from the discharge port 46 to the casing. 10 is discharged together with the air in the recovery pipe 47. The fine powder discharged to the collection tube 47 is collected as a fine powder product by the subsequent collecting means.
When the suction fan sucks the fine powder and air from the discharge port 46, air is introduced into the recovery pipe 47 from the gap 50, and the flow rates of the fine powder and air in the recovery pipe 47 become high.
Since the fine powder flows together with air in the collection tube 47 at high speed, the fine powder is prevented from adhering in the collection tube 47.

Particles having a large particle size and a large mass do not accompany the air in the casing 10 sucked from the discharge port 46 by the suction fan, and are generated in the backward return airflow generated in the outer peripheral portion of the classification region S along the tapered wall 42. Accompanied by returning to the pulverization region C, pulverization is performed. The return airflow is generated by the rotation of the second rotary blade 33.
JP 2005-177704 A

In the airflow type pulverizer 1, the raw material is introduced into the swirl region R and the air is introduced from the supply passage 28, which causes the following problems.
When the operation of the airflow crusher 1 is started, the inside of the casing 10 is empty including the crushing region C. When the first rotary blade 32 and the second rotary blade 33 rotate in such a state, the return airflow from the classification region S to the pulverization region C becomes stronger than the airflow from the swirl region R to the pulverization region C. For this reason, air spouts out of the casing 10 from the charging passage 22, and the raw material is spouted together with the air. After a while after the operation of the airflow pulverizer 1 is started, the raw material enters the pulverization region C, and the airflow from the swirl region R to the pulverization region C becomes stronger than the return airflow from the classification region S to the pulverization region C. Then, the ejection of air and raw materials to the outside of the casing 10 stops.

When the operation of the airflow crusher 1 is stopped, the classification ability decreases as the rotation of the first rotary blade 32 and the second rotary blade 33 becomes slow, and particles having a large particle diameter and a large mass do not return to the pulverization region C. . In addition, the blocking action is reduced, and particles having a large particle size and a large mass move from the crushing region C to the classification region S.
Even if the classification ability is reduced, the suction fan sucks the air in the casing 10, and the air is introduced into the recovery pipe 47 from the gap 50. For this reason, particles having a large particle size and a large mass are easily drawn into the collection tube 47 from the classification region S, and particles that are not sufficiently pulverized are mixed in the fine powder product, which deteriorates the quality of the fine powder product. Resulting in.

The present invention solves the above-mentioned problems, and the object of the present invention is to prevent the raw material from being ejected from the casing at the start of operation, and particles that are not sufficiently pulverized at the time of the operation stop. to provide a method of operating to that gas-flow pulverizer prevented from being mixed in.

In order to solve the above-described problem, an airflow crusher operating method according to a first aspect of the present invention includes separating a first rotor blade and a second rotor blade from each other by a predetermined distance in a casing. A swirl region behind the first rotor blade in the casing, a grinding region between the first rotor blade and the second rotor blade, a classification region in front of the second rotor blade, An operation method of an airflow type pulverizer that generates a swirling airflow by rotation of a second rotary blade and pulverizes and classifies a raw material that is input to the swirl region, a raw material charging unit that charges the raw material to the swirl region, and a swirl region A swirl area intake section for introducing air and an on-off valve for controlling air introduced into the swirl area intake section are provided, and when the operation of the airflow type pulverizer is started, the on / off valve of the swirl area intake section is fully closed. Alternatively, start the airflow crusher after reducing the opening, and open the operation. And after a predetermined time has elapsed, to open the on-off valve of the swivel region intake unit.

According to the first aspect of the invention, when the operation of the airflow type pulverizer is started, the opening / closing valve of the swirl region intake section is fully closed or the opening degree is reduced, and the introduction of air into the swirl region is stopped or restricted. When the introduction of air to the swirl area is stopped or restricted, the air that can be ejected from the swirl area to the outside of the casing is reduced, and the raw material is prevented from being ejected from the swirl area to the outside of the casing together with the air.
After a predetermined time has passed since the operation of the airflow type pulverizer has been started and the raw material has entered the pulverization region, the opening / closing valve of the swirl region intake section is opened to introduce air into the swirl region. Since the raw material is contained in the grinding area, the airflow from the swirl area to the grinding area is stronger than the return airflow from the classification area to the grinding area, and no air is blown out of the casing from the swirl area. No eruption.

The airflow crusher operating method according to the second invention is characterized in that the first rotor blade and the second rotor blade are provided in the casing so as to be separated from each other by a predetermined distance, and swivel to the rear of the first rotor blade in the casing. A pulverization area is formed between the first rotor blade and the second rotor blade, and a classification area is formed in front of the second rotor blade, and a swirling airflow is generated by the rotation of the first rotor blade and the second rotor blade. A method of operating an airflow type pulverizer that performs pulverization and classification of raw materials input to a region, a raw material input unit that inputs the raw material to the swirl region, a swirl region intake unit that introduces air to the swirl region, and a swirl region intake And an on-off valve for controlling the air introduced into the section, and when stopping the operation of the airflow type pulverizer, after closing the on-off valve of the swirl region intake section and a predetermined time has elapsed, Stop rotating blades.

According to the second aspect of the invention, when the operation of the airflow type pulverizer is stopped, the opening / closing valve of the swirl region intake section is closed in advance and the introduction of air into the swirl region is stopped. When the introduction of air into the swirl area is stopped, the air sucked by the suction fan and flowing from the casing into the recovery pipe is also reduced. After the opening / closing valve of the swirl region intake section is closed and a predetermined time has elapsed, the rotation of the first rotary blade and the second rotary blade is stopped, and the operation of the airflow type pulverizer is stopped. The air sucked by the suction fan and flowing from the inside of the casing to the recovery pipe is reduced, and particles having a large particle size and a large mass are prevented from being sucked into the recovery pipe together with the air in the casing by the suction fan. Therefore, even if the classification ability is reduced, particles that are not sufficiently pulverized are prevented from being mixed into the fine powder product.
It should be noted that a predetermined time from when the opening / closing valve of the swirl region intake section is closed to when the rotation of the first rotor blade and the second rotor blade is stopped, and from the start of operation when starting the operation of the airflow type pulverizer, The predetermined time until the opening / closing valve of each part is opened is determined according to the capability of the airflow crusher, and may be the same or different.

Moreover, the operating method of the airflow type pulverizer according to the third invention is the operating method of the airflow type pulverizer according to the second invention, wherein the classification region front intake part for introducing air in front of the classification region, An opening / closing valve for controlling the air introduced into the classification area front intake section, and when the operation of the airflow type pulverizer is stopped, the opening / closing valve of the classification area front intake section is closed and a first time has passed. Stop the rotation of the rotor blade and the second rotor blade.

According to the third invention, when stopping the operation of the airflow type pulverizer, the opening / closing valve of the classification area front intake part is closed in advance, the air introduced into the recovery pipe is reduced, and the flow of air in the recovery pipe is reduced. deep. When the opening / closing valve of the classification area front intake portion is closed and a predetermined time has elapsed, the rotation of the first rotary blade and the second rotary blade is stopped, and the operation of the airflow type pulverizer is stopped. Even if the classification ability is reduced, the flow of air in the collection tube is slow, and particles with large particle size and mass are prevented from being drawn into the flow of air in the collection tube. Particles that are not treated are prevented from entering the fine powder product.

  It should be noted that a predetermined time from when the opening / closing valve of the classification area front intake section is closed to when the first rotor blade and the second rotor blade are stopped, and after the opening / closing valve of the swirl area intake section is closed, the first rotor blade and the second rotor blade The predetermined time until the rotation of the rotor blades is stopped and the predetermined time from the start of operation when the operation of the airflow type pulverizer is started until the opening / closing valve of the swirl region intake section is opened are respectively the capabilities of the airflow type pulverizer. And may be the same or different.

  Since the airflow pulverizer and the operation method of the airflow pulverizer are as described above, the raw material is prevented from being ejected from the casing at the start of operation, and the particles that are not sufficiently pulverized at the time of the operation stop are fine powder products. It is possible to provide an airflow pulverizer that can prevent mixing in and an operation method of the airflow pulverizer.

The best mode for carrying out the present invention will be described with reference to FIGS.
The basic configuration of the airflow crusher 1 is the same as that shown in FIG.
As shown in FIG. 1, the casing 10 of the airflow type pulverizer 1 is constituted by a charging side casing 11, a center casing 12 and a discharging side casing 13, and a shaft passing through the charging side casing 11 is provided in the casing 10. A first rotary blade 32 and a second rotary blade 33 are attached to a front end (a left end in the figure) of FIG. The shaft 17 is rotatably supported by a frame 18 via a bearing, and is configured to rotate by a motor (not shown).

As shown in FIGS. 1 and 2, a tapered wall 41 and a hanging wall 43 are formed inside the charging-side casing 11, and the diameter of the tapered wall 41 gradually decreases toward the rear, so that the hanging wall 43 is a tapered wall 41. It is perpendicular to the shaft 17 at the rear end. A space between the first rotary blade 32 and the hanging wall 43 forms a swirl region R.
A raw material input passage 21 is formed in the input side casing 11 as a raw material input portion. The raw material charging passage 21 is a passage communicating in the vertical direction and is formed perpendicular to the shaft 17. The upper end inlet of the raw material input passage 21 is connected to the screw feeder 24, the lower end outlet is opened in the tapered wall 41, and the raw material is input to the turning region R from a direction perpendicular to the shaft 17.

  Separately from the raw material introduction passage 21, an air introduction passage 26 is formed in the introduction casing 11 as a swirl region intake portion, and one end of the air introduction passage 26 opens as an outlet to a lower portion of the tapered wall 41, and is connected to the shaft 17. On the other hand, air is introduced into the swivel region R from a direction perpendicular thereto. An open / close valve 29 is provided in the air introduction passage 26. The outlet of the air introduction passage 26 and the outlet of the raw material introduction passage 21 are spaced apart from each other by 90 ° in the circumferential direction of the tapered wall 41.

The center casing 12 has a cylindrical shape, and the space between the first rotary blade 32 and the second rotary blade 33 forms a grinding region C.
A tapered wall 42 is formed inside the discharge-side casing 13, the diameter of the taper wall 42 gradually decreases toward the front, and a discharge port 46 opens at the front end of the discharge-side casing 13. A suction fan (not shown) is connected to the discharge port 46 via a recovery pipe 47. A gap 50 is formed in front of the classification region S and between the discharge port 46 and the rear end of the collection pipe 47.

  A discharge side air introduction casing 14 is formed on the outer peripheral side of the discharge side casing 13. A ring-shaped passage 28 is formed between the discharge-side air introduction casing 14 and the discharge-side casing 13, and the ring-shaped passage 28 communicates with the gap 50. An air introduction passage 27 is formed in the discharge side air introduction casing 14, and air is introduced to the front of the classification region S through the air introduction passage 27, the ring-shaped passage 28 and the gap 50. An open / close valve 30 is provided in the air introduction passage 27, and the air introduction passage 27, the ring-shaped passage 28, and the gap 50 form a classification region front intake portion.

The first rotating blade 32 and the second rotating blade 33 are provided with a plurality of blades 36 and 38 radially around the bosses 34 and 35, and rotate by the rotation of the shaft 17, and the airflow swirling in the casing 10 is generated. It has a configuration that occurs. Note that the blades 36 of the first rotary blade 32 impart a swirl force to the airflow generated in the swirl region R and also a forward thrust to facilitate introduction of the raw material from the swirl region R to the pulverization region C. It has a possible shape.
An inclined surface 38 is formed at the tip of the blade 37 of the second rotary blade 33, and the inclined surface 38 faces the tapered wall 42 of the discharge-side casing 13. A space between the second rotary blade 33 and the discharge-side casing 13 and a space along the tapered wall 42 in front of the space form a classification region S.

Next, the operation will be described.
When the operation of the airflow crusher 1 is started, first, the on-off valve 29 of the air introduction passage 26 is closed. The on-off valve 29 is closed, the first rotary blade 32 and the second rotary blade 33 are rotated, and the raw material is charged into the swirl region R from the raw material charging passage 21 by the screw feeder 24.
The on-off valve 29 of the air introduction passage 26 is closed, so that no air is introduced from the air introduction passage 26 into the swirl region R, and less air enters the swirl region R from the raw material input passage 21. For this reason, there is little air flowing in the casing 10, and even if the first rotary blade 32 and the second rotary blade 33 rotate, there is almost no air jetted out of the casing 10 from the swivel region R, and the raw material is outside the casing 10. It does not erupt.

When the operation of the airflow type pulverizer 1 is started and a predetermined time T1 has elapsed, the raw material enters the pulverization region C from the turning region R. When the raw material enters the pulverization region C, the open / close valve 29 of the air introduction passage 26 is opened, and air is introduced into the swirl region R.
The air introduced from the air introduction passage 26 swirls along the tapered wall 41 of the charging side casing 11 and becomes a swirling airflow in the swirling region R. The raw material charged from the raw material charging passage 21 swirls together with the swirling airflow, and flows radially outward by centrifugal force. In addition, the suction fan sucks the air in the casing 10 toward the discharge port 46, and a differential pressure is generated between the swivel region R and the pulverization region C. Due to this differential pressure, air is continuously introduced from the air introduction passage 26 into the swirl region R.

Since the outlet of the air introduction passage 26 opens at a lower portion of the taper wall 41, the air introduced from the air introduction passage 26 blows off the raw material accumulated below the swirl region R, and the blown raw material is combined with the swirling airflow. Turn to.
Due to the differential pressure between the swirl region R and the crushing region C and the forward thrust imparted to the swirl airflow by the first rotary blade 32, the raw material swirling in the swirl region R is between the blades 36 of the first rotary blade 32. Through to the grinding zone C. In the pulverization region C, the larger the particle diameter, the larger the centrifugal force acts, and the higher the peripheral speed gathers on the radially outer peripheral side, and the pulverization occurs mainly due to the grinding between the particles and also due to the collision between the particles. Is done. At this time, the 2nd rotary blade 33 blocks the raw material in the grinding | pulverization area | region C moving to a classification area | region. This blocking action is generated by an airflow curtain formed on the surface of the second rotary blade 33.

  Among the raw materials pulverized in the pulverization region C, particles having a smaller particle diameter and smaller mass gather in the vicinity of the rotation center of the second rotary blade 33 having a lower pressure, and are sucked as fine powder by a suction fan and are discharged from the discharge port 46 to the casing. 10 is discharged together with the air in the recovery pipe 47. The fine powder discharged to the collection tube 47 is collected as a pulverized product by the subsequent collection means. The particles having a large particle diameter and a large mass do not accompany the air in the casing 10 sucked by the suction fan, and are generated in the backward return airflow generated in the outer peripheral portion of the classification region S along the tapered wall 42 of the discharge-side casing 13. To return to the pulverization region C and pulverize.

  When a predetermined time T1 has elapsed since the start of the operation of the airflow crusher 1 and the on-off valve 29 of the air introduction passage 26 is opened, the raw material is already in the crushing region C, and the swirl region R is transferred to the crushing region C. The airflow is stronger than the return airflow from the classification area S to the grinding area C. Therefore, even if the on-off valve 29 is opened and air is introduced into the swirl region R, the introduced air is not ejected from the swirl region R to the outside of the casing 10, and the raw material is ejected from the swirl region R to the outside of the casing 10. Nor.

When the opening / closing valve 30 of the air introduction passage 27 is opened, when the suction fan sucks the fine powder from the discharge port 46, air passes through the air introduction passage 27, the ring-shaped passage 28 and the gap 50 from the front of the classification region S. It flows into the recovery pipe 47. The air flowing from the gap 50 increases the flow rates of the fine powder and air in the recovery pipe 47.
When stopping the operation of the airflow crusher 1, the on-off valve 29 of the air introduction passage 26 and the on-off valve 30 of the air introduction passage 27 are closed a predetermined time T2 before the stop. When the on-off valve 29 is closed, the introduction of air into the swivel region R is stopped, and the air sucked into the recovery pipe 47 from the casing 10 by the suction fan is reduced. When the on-off valve 30 is closed, there is no air flowing into the recovery pipe 47 from the gap 50, and the air flowing in the recovery pipe 47 becomes low speed.

  When the on-off valve 29 and the on-off valve 30 are closed and a predetermined time T2 has elapsed, the first rotary blade 32 and the second rotary blade 33 are stopped. When the rotation of the first rotary blade 32 and the second rotary blade 33 becomes slow, the classification ability in the classification region S is reduced. When the classification ability is lowered, particles having a large particle size and a large mass remain in the classification region S. Further, the blocking action is weakened, and particles having a large particle diameter and a large mass move from the crushing region C to the crushing region C.

However, since the air sucked into the collection pipe 47 from the casing 10 is reduced and the air flowing through the collection pipe 47 is low speed, particles having a large particle diameter and a large mass remaining in the classification region S are present. Further, suction or drawing into the collection tube 47 is prevented, and particles that are not sufficiently pulverized are prevented from being mixed into the fine powder product.
In the present embodiment, the air introduction passage 26 formed in the charging casing 11 is one place. However, the number of the air introduction passages 26 is not limited to one place, and can of course be formed in several places. It is. For example, as shown in the modification of FIG. 3, a plurality of air introduction passages 26 and raw material introduction passages 21 can be arranged at 90 ° intervals in the circumferential direction of the introduction side casing 11.

It is sectional drawing of the airflow type grinder based on this invention. It is an inner surface lineblock diagram of a loading side casing. It is an inner surface block diagram of the input side casing of the airflow type crusher which concerns on a modification. It is sectional drawing of the conventional airflow type grinder. It is an inner surface block diagram of the input side casing of the conventional airflow type crusher.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Airflow type grinder 10 Casing 11 Input side casing 12 Center casing 13 Discharge side casing 14 Discharge side air introduction casing 17 Shaft 18 Frame 21 Raw material input passage 24 Screw feeder 26, 27 Air introduction passage 28 Ring-shaped passage 29, 30 On-off valve 32 First rotary blade 33 Second rotary blade 34, 35 Boss 36, 37 Blade 38 Inclined surface 41, 42 Tapered wall 43 Vertical wall 43
46 Discharge port 47 Collection pipe 50 Clearance R Turning area C Grinding area S Classification area

Claims (3)

The first rotor blade and the second rotor blade are provided in the casing so as to be separated from each other by a predetermined distance, the swirl region is located behind the first rotor blade in the casing, and the pulverization region is between the first rotor blade and the second rotor blade. The operation of an air-flow type pulverizer that forms a classification area in front of the second rotary blade, generates a swirling airflow by the rotation of the first rotary blade and the second rotary blade, and crushes and classifies the raw material input to the swirl area A method,
A raw material input unit for introducing the raw material into the swirl region, a swirl region intake unit for introducing air into the swirl region, and an on-off valve for controlling the air introduced into the swirl region intake unit,
When starting the operation of the airflow type pulverizer, the opening / closing valve of the swirl region intake part is fully closed or the opening degree is reduced, and then the operation of the airflow type pulverizer is started. A method of operating an airflow type pulverizer characterized by opening an on-off valve of a swirl region intake section later. The first rotor blade and the second rotor blade are provided in the casing so as to be separated from each other by a predetermined distance, the swirl region is located behind the first rotor blade in the casing, and the pulverization region is between the first rotor blade and the second rotor blade. The operation of an air-flow type pulverizer that forms a classification area in front of the second rotary blade, generates a swirling airflow by the rotation of the first rotary blade and the second rotary blade, and crushes and classifies the raw material input to the swirl area A method,
A raw material input unit for introducing the raw material into the swirl region, a swirl region intake unit for introducing air into the swirl region, and an on-off valve for controlling the air introduced into the swirl region intake unit,
When stopping the operation of the airflow pulverizer, the airflow pulverization is characterized by stopping the rotation of the first rotor blade and the second rotor blade after a predetermined time has elapsed after closing the on-off valve of the swirl region intake section. How to operate the machine. A classification area front intake part that introduces air in front of the classification area; and an on-off valve that controls air introduced into the classification area front intake part,
When stopping the operation of the gas-flow pulverizer, claims, characterized by closing the on-off valve of the classifying region forward intake section after a predetermined time has elapsed, to stop the rotation of the first rotating blade and the second rotating blade 3. A method of operating the airflow type pulverizer according to 2 .

Images