JP2007268458A - Air stream type crusher - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air stream type crusher capable of recovering a fine powder without oxidation. <P>SOLUTION: In the air stream type crusher 1 in which a first rotation impeller 28 and a second rotation impeller 29 are rotated in a casing 3 to perform crushing and classification of a thrown material, a material throwing passage 16 for throwing the material to a swirl area R, a nitrogen introduction passage 20 for introducing nitrogen to the swirl area R and a nitrogen introduction passage 21 for introducing nitrogen to the front side of a classification area S are provided. The nitrogen discharged with the fine powder is recovered and the recovered nitrogen is returned to the nitrogen introduction passages 20, 21. <P>COPYRIGHT: (C)2008,JPO&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, a fine powder manufacturing apparatus has been used to pulverize various raw materials such as agricultural products and minerals into fine powder (see, for example, Patent Document 1). As shown in FIGS. 3 and 4, the fine powder production apparatus includes an airflow-type pulverizer 1, and the casing 3 of the airflow-type pulverizer 1 is constituted by an input side casing 4, a center casing 5, and a discharge side casing 6. In the casing 3, a first rotary blade 28 and a second rotary blade 29 are attached to a front end (left end in FIG. 3) of the shaft 10 penetrating the input side casing 4 so as to be separated from each other by a predetermined distance. Yes. The shaft 10 is rotatably supported by a frame 11 via a bearing and is configured to rotate by a motor 12.

A tapered wall 37 is formed inside the charging-side casing 4, the diameter of the tapered wall 37 gradually decreases rearward, and a space behind the first rotary blade 28 forms a swivel region R.
An input passage 15 is formed in the input side casing 4 in a direction perpendicular to the shaft 10. The lower end outlet of the input passage 15 opens to the tapered wall 37, and the raw material is supplied to the swirl region R from the input passage 15 and the outside air is introduced.

The center casing 5 has a cylindrical shape, and the space between the first rotary blade 28 and the second rotary blade 29 forms a grinding region C.
A tapered wall 38 is formed inside the discharge-side casing 6, the diameter of the taper wall 38 gradually decreases toward the front, and a discharge port 40 opens at the front end of the discharge-side casing 6.
The first rotary vane 28 and the second rotary vane 29 are provided with a plurality of blades 32, 33 radially around the bosses 30, 31. The first rotary vane 28 and the second rotary vane 29 are rotated by the rotation of the shaft 10 and rotate in the casing 3. It has a configuration in which a flow is generated. Note that the blades 32 of the first rotary blade 28 impart a swirl force to the airflow generated in the swirl region R and also impart 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 34 is formed at the tip of the blade 33 of the second rotary blade 29, and the inclined surface 34 faces the tapered wall 38 of the discharge-side casing 6. A space between the second rotary blade 29 and the discharge-side casing 6 and a space along the tapered wall 38 in front of the space constitute a classification region S.
A structure in which a suction fan 51 is connected to a discharge port 40 of the discharge-side casing 6 via a recovery pipe 44, and the suction fan 51 sucks and discharges fine powder pulverized by the airflow pulverizer 1 together with air. It has become. A gap 42 is formed between the discharge port 40 and the collection pipe 44, that is, in the front portion of the classification region S, and the outside air can be introduced from the gap 42 by the suction fan 51. The suction fan 51 is connected to a collection hopper 48 containing a bag filter via a transport pipe 45 and is configured to collect fine powder in the airflow sent from the suction fan 51.

The raw material charged into the airflow crusher 1 from the charging passage 15 enters the swirl region R, swirls along the airflow swirling in the swirl region R, and flows outward in the radial direction by centrifugal force. Further, the suction fan 51 sucks the air in the casing 3 toward the discharge port 40, and a differential pressure is generated between the swivel region R and the pulverization region C.
Due to this differential pressure and the forward thrust of the air flow generated by the first rotary blade 28, the raw material swirling in the swirl region R passes between the blades 32 of the first rotary blade 28 and enters the grinding region 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 29 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 29.

  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 29 having a lower pressure, and are sucked as fine powder by the suction fan 51 and discharged from the discharge port 40. The air in the casing 3 is discharged together with the recovery pipe 44. The fine powder discharged to the collection pipe 44 enters the suction fan 51, is transported to the collection hopper 48 through the transport pipe 45, is separated from the air by the bag filter of the collection hopper 48, and is collected as a fine powder product.

When the suction fan 51 sucks the fine powder and the air in the casing 3 from the discharge port 40, the outside air is introduced into the recovery pipe 44 from the gap 42, and the flow rates of the fine powder and air in the recovery pipe 44 become high. Since the fine powder flows through the collection tube 44 at a high speed, the fine powder is prevented from adhering to the collection tube 44.
Particles having a large particle diameter and a large mass return to the pulverization region C and are pulverized along with the backward flow of air generated in the outer periphery of the classification region S along the tapered wall 38.
JP 2005-177704 A

In the airflow pulverizer 1, outside air is introduced into the casing 3 together with the raw material from the charging passage 15, the raw material is pulverized in an air atmosphere, and the pulverized fine powder is introduced from the air and the gap 42 in the casing 3. It is transported from the airflow crusher 1 to the recovery hopper 48 together with the outside air. During this time, the raw materials and fine powder are exposed to the air. For this reason, when the raw material which is easy to oxidize is grind | pulverized by the airflow-type grinder 1, oxidation of a raw material and a fine powder becomes a problem. As the particle size of the fine powder becomes smaller, the surface area that comes into contact with air becomes larger, and the fine powder becomes more easily oxidized. Therefore, when the raw material which is easy to oxidize is pulverized by the airflow pulverizer 1, it is difficult to recover the fine powder without being oxidized.
The present invention solves the above problems, and an object of the present invention is to provide an airflow type pulverizer that can recover fine powder without oxidizing it.

  The present invention adopts the following configuration in order to solve the problem. The airflow type pulverizer according to the invention of claim 1 is provided with a first rotary blade and a second rotary blade spaced apart from each other by a predetermined distance in the casing, and a swirl region, a first rotary blade behind the first rotary blade in the casing. A crushing region is formed between the rotor blade and the second rotor blade, and a classification region is formed in front of the second rotor blade. A swirling airflow is generated by the rotation of the first rotor blade and the second rotor blade, and the swirl region is introduced. An airflow type pulverizer that performs pulverization and classification of raw materials and discharges the fine powder of the pulverized raw materials, and includes a raw material input unit that inputs the raw materials into the swirl region, and a swirl region that introduces an inert gas into the swirl region. And an active gas introduction section.

  Since the raw material charging unit and the swirl region inert gas introduction unit are respectively provided, it is possible to individually carry in the raw material and to introduce the inert gas into the swirl region. When the inert gas is introduced from the swirl region inert gas introduction part, the inside of the casing can be filled with the raw material and the inert gas, and the raw material can be pulverized into a fine powder in the casing under an inert gas atmosphere. Therefore, the raw material and fine powder are prevented from being exposed to the air and oxidized.

An airflow pulverizer according to a second aspect of the present invention is the airflow pulverizer according to the first aspect, wherein the inert gas discharged together with the fine powder of the pulverized raw material is recovered, and the swirl region is not restored. An inert gas recovery device for returning to the active gas introduction unit is provided.
The inert gas introduced into the casing is sucked into the collection tube by the suction fan together with the fine powder. If the inert gas sucked into the recovery pipe is recovered by the inert gas recovery device and returned to the swirl region inert gas introduction part, the consumption amount of the inert gas is suppressed and the operation efficiency is improved.

An airflow type pulverizer according to the invention of claim 3 is the airflow type pulverizer according to claim 1 or 2, wherein the classification region forward inert gas introduction section introduces an inert gas in front of the classification region. Is provided.
When the inert gas is introduced from the inert gas introduction part in front of the classification area to the front of the classification area, the introduced inert gas flows into the recovery pipe, the flow rate of the inert gas in the recovery pipe becomes high, and the fine powder also enters the recovery pipe. The fine powder is prevented from adhering in the collection tube. Further, it is possible to prevent the fine powder from being exposed to the air in the recovery tube and being oxidized.

An airflow type pulverizer according to a fourth aspect of the present invention is the airflow type pulverizer according to the third aspect, wherein the inert gas discharged together with the fine powder of the pulverized raw material is recovered and again in front of the classification region. An inert gas recovery device for returning to the inert gas introduction unit is provided.
By collecting the inert gas introduced from the inert gas introduction part at the front of the classification area and flowing into the recovery pipe and returning it to the inert gas introduction part at the front of the classification area, the consumption of the inert gas is suppressed and the operation efficiency is improved Is planned.

  Since it is an airflow type pulverizer as described above, it is possible to provide an airflow type pulverizer that can collect fine powder without oxidizing it.

The best mode for carrying out the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of an airflow type pulverizer according to the present invention, and FIG.
The basic configuration of the airflow crusher 1 is the same as that shown in FIG.
The casing 3 of the airflow type pulverizer 1 is composed of an input side casing 4, a center casing 5, and a discharge side casing 6. In the casing 3, the front end of the shaft 10 that penetrates the input side casing 4 (in FIG. 1). The first rotary blade 28 and the second rotary blade 29 are attached to the left end) separated from each other by a predetermined distance. The shaft 10 is rotatably supported by a frame 11 via a bearing and is configured to rotate by a motor 12.

A tapered wall 37 is formed inside the charging-side casing 4, the diameter of the tapered wall 37 gradually decreases rearward, and a space behind the first rotary blade 28 forms a swivel region R.
A raw material charging passage 16 as a raw material charging portion is formed in the charging side casing 4 perpendicularly to the shaft 10. The upper end inlet of the raw material input passage 16 is connected to the screw feeder 17, the lower end outlet of the raw material input passage 16 opens to the tapered wall 37, and the raw material is input to the swirl region R from the raw material input passage 16.

Aside from the raw material supply passage 16, a nitrogen introduction passage 20 is formed as a swirl region nitrogen introduction portion in the introduction side casing 4, and one end of the nitrogen introduction passage 20 opens as an outlet to the tapered wall 37, with respect to the shaft 10. Nitrogen is introduced into the swivel region R from a vertical direction.
In the present embodiment, nitrogen is used as the inert gas, but the present invention is not limited to this, and a rare gas (noble gas) such as helium or argon may be used as the inert gas, or pulverization. Carbon dioxide gas may be used depending on the raw material to be treated.

The nitrogen introduction passage 20 is connected to a nitrogen pipe 59 of a nitrogen recovery device, which will be described later, via an on-off valve 24. The outlet of the nitrogen introduction passage 20 and the outlet of the raw material introduction passage 16 are at different positions on the tapered wall 37.
The center casing 5 has a cylindrical shape, and the space between the first rotary blade 28 and the second rotary blade 29 forms a grinding region C.

A tapered wall 38 is formed inside the discharge-side casing 6, the diameter of the taper wall 38 gradually decreases toward the front, and a discharge port 40 opens at the front end of the discharge-side casing 6.
A rear end portion of the collection pipe 44 is connected to the discharge port 40. A gap 42 is formed in the front portion of the classification region S between the discharge port 40 and the rear end of the collection pipe 44.
A discharge side nitrogen introduction casing 7 is formed on the outer peripheral side of the discharge side casing 6. A ring-shaped passage 22 is formed between the discharge-side nitrogen introduction casing 7 and the discharge-side casing 6, and the ring-shaped passage 22 communicates with the gap 42. A nitrogen introduction passage 21 is formed in the discharge side nitrogen introduction casing 7, and the nitrogen introduction passage 21 is connected to a nitrogen pipe 59 through an on-off valve 25. The nitrogen introduction passage 21, the ring-shaped passage 22, and the gap 42 form a classification region front nitrogen introduction portion.

  The first rotor blade 28 and the second rotor blade 29 are provided with a plurality of blades 32, 33 radially around the bosses 30, 31. It has a configuration that occurs. The blade 32 of the first rotary blade 28A imparts a swirling force to the airflow generated in the swirl region R and also imparts 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 34 is formed at the tip of the blade 33 of the second rotary blade 29, and the inclined surface 34 faces the tapered wall 38 of the discharge-side casing 6. A space between the second rotary blade 29 and the discharge-side casing 6 and a space along the tapered wall 38 in front of the space constitute a classification region S.
A collection pipe 44 is connected to a collection hopper 48 containing a bag filter 49. A suction fan 51 is connected to the collection hopper 48, and the suction fan 51 sucks fine powder pulverized by the airflow type pulverizer 1 together with nitrogen into the bag filter 49, and the bag filter 49 extracts fine powder and nitrogen. It is the structure which isolate | separates. The collection hopper 48 is connected to a collection tank 55 via a rotary valve 53 and a collection valve 54, and is configured to collect the fine powder separated by the bag filter 49 in the collection tank 55.

  One end of a nitrogen pipe 59 is connected to the suction fan 51, and the nitrogen separated by the bag filter 49 is sucked by the suction fan 51 and discharged to the nitrogen pipe 59. The other end side of the nitrogen pipe 59 is connected to the nitrogen introduction passages 20 and 21. The nitrogen pipe 59 is provided with a cooler 60 that cools nitrogen discharged from the suction fan 51 to the nitrogen pipe 59. An exhaust pipe 61 branches from a nitrogen pipe 59 between the suction fan 51 and the suction fan 51. Further, a nitrogen supply device 62 is connected to the nitrogen pipe 59, and is configured so that nitrogen can be appropriately supplied from the nitrogen supply device 62 to the nitrogen pipe 59. The bag filter 49, the suction fan 51, the nitrogen pipe 59, and the cooler 60 constitute a nitrogen recovery device.

Next, the operation will be described.
The raw material is charged into the swirl region R from the raw material charging passage 16 by the screw feeder 17. By using the screw feeder 17, it is possible to suppress air from entering the swirl region R from the raw material charging passage 16 together with the raw material.
Nitrogen is supplied from the nitrogen supply device 62 to the nitrogen pipe 59 and the on-off valves 24 and 25 of the nitrogen introduction passages 20 and 21 are opened. When the on-off valve 24 is opened, nitrogen is introduced into the swirl region R through the nitrogen introduction passage 20. When the on-off valve 25 is opened, nitrogen is introduced to the front of the classification region S through the nitrogen introduction passage 21, the ring-shaped passage 22 and the gap 42.

Only the raw material introduced from the raw material introduction passage 16 and the nitrogen introduced from the nitrogen introduction passage 20 enter the casing 3, and the inside of the casing 3 becomes a nitrogen atmosphere.
Nitrogen introduced from the nitrogen introduction passage 20 swirls along the tapered wall 37 of the charging-side casing 4 and becomes a swirling airflow in the swirling region R. The raw material charged from the raw material charging passage 16 swirls together with the swirling airflow, and flows radially outward by centrifugal force. The suction fan 51 sucks nitrogen in the casing 3 toward the discharge port 40, and a differential pressure is generated between the swivel region R and the pulverization region C. Due to this differential pressure, nitrogen continuously flows from the nitrogen introduction passage 20 into the swirl region R.

  Due to the differential pressure between the swirl region R and the crushing region C and the forward thrust applied to the swirl airflow by the first rotary blade 28, the raw material swirling in the swirl region R is between the blades 32 of the first rotary blade 28. 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 29 blocks the raw material in the grinding | pulverization area | region C moving to a classification area | region. This blocking action is generated by a nitrogen airflow curtain formed on the surface of the second rotor blade 29.

  Among the raw materials pulverized in the pulverization region C, particles having a smaller particle diameter and smaller mass gather near the rotation center of the second rotary blade 29 having a lower pressure, and are sucked as fine powder by the suction fan 51 and are discharged from the discharge port 40. The nitrogen in the casing 3 is discharged together with the recovery pipe 44. The particles having a large particle diameter and a large mass do not accompany the nitrogen in the casing 3 sucked by the suction fan 51, and return to the rear generated in the outer peripheral portion of the classification region S along the tapered wall 38 of the discharge-side casing 6. It returns to the grinding | pulverization area | region C with an airflow, and is crushed.

When the suction fan 51 sucks the fine powder from the discharge port 40 into the collection pipe 44, the nitrogen introduced into the front portion of the classification region S flows into the collection pipe 44 through the gap 42. The nitrogen flowing into the recovery pipe 44 from the gap 42 increases the flow rate of the fine powder and nitrogen in the recovery pipe 44 and prevents the fine powder from adhering in the recovery pipe 44.
Fine powder and nitrogen discharged from the discharge port 40 to the collection pipe 44 by the suction fan 51 are sucked into the bag filter 49 of the collection hopper 48 together with nitrogen introduced from the gap 42, and the fine powder and nitrogen are separated in the bag filter 49. To be separated. The separated fine powder is recovered from the recovery hopper 48 to the recovery tank 55. The separated nitrogen is recovered from the bag filter 49 through the suction fan 51 to the nitrogen pipe 59. The nitrogen recovered in the nitrogen pipe 59 enters the cooler 60 and is cooled. Nitrogen cooled by the cooler 60 flows from the nitrogen pipe 59 to the nitrogen introduction passages 20 and 21.

When nitrogen cooled by the cooler 60 begins to flow into the nitrogen introduction passages 20 and 21, supply of nitrogen from the nitrogen supply device 62 to the nitrogen pipe 59 is stopped.
The raw material pulverization in the airflow pulverizer 1 is performed in the casing 3 under a nitrogen atmosphere, and the fine powder is transported from the airflow pulverizer 1 to the recovery hopper 48 along with the nitrogen in the recovery pipe 44. Since the inside of 44 is also in a nitrogen atmosphere, exposure of raw materials and fine powder to the air is prevented. Therefore, even when the raw material that is easily oxidized is pulverized, the fine powder is prevented from being oxidized and can be recovered without oxidizing the fine powder.

Further, since nitrogen is recovered from the suction fan 51 to the nitrogen pipe 59 and flows again into the nitrogen introduction passages 20 and 21, the consumption of nitrogen can be reduced and the operation efficiency is improved.
When the operation of the airflow crusher 1 is stopped, the on-off valves 24 and 25 of the nitrogen introduction passages 20 and 21 are closed a predetermined time before the stop. When the on-off valve 24 is closed, the introduction of nitrogen into the swirl region R is stopped, and the nitrogen sucked into the recovery pipe 44 from the casing 3 by the suction fan 51 is reduced. Further, when the on-off valve 25 is closed, the flow of nitrogen from the gap 42 into the recovery pipe 44 is stopped, and the nitrogen in the recovery pipe 44 becomes low speed.

  When the on-off valves 24 and 25 are closed and a predetermined time has elapsed, the rotation of the first rotary blade 28 and the second rotary blade 29 is stopped. When the rotation of the first rotary blade 28 and the second rotary blade 29 is slow, the classification ability in the classification region S is reduced, and particles having a large particle diameter 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 nitrogen sucked into the recovery pipe 44 from the casing 3 is reduced and the flow of nitrogen in the recovery pipe 44 is low, particles having a large particle size and a large mass are collected from the classification region S into the recovery pipe. 44 is prevented from being sucked or drawn in, and particles not sufficiently pulverized are also prevented from being mixed into the fine powder product.

It is sectional drawing of the airflow type grinder based on this invention. It is a block diagram of a fine powder manufacturing apparatus provided with the airflow type crusher which concerns on this invention. It is sectional drawing of the conventional airflow type grinder. It is a block diagram of the fine powder manufacturing apparatus provided with the conventional airflow type crusher.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Airflow type grinder 3 Casing 4 Input side casing 5 Center casing 6 Discharge side casing 7 Discharge side nitrogen introduction casing 10 Shaft 11 Frame 12 Motor 16 Raw material input passage 17 Screw feeder 20, 21 Nitrogen introduction passage 22 Ring-shaped passages 24, 25 On-off valve 28 First rotary blade 29 Second rotary blade 30, 31 Boss 32, 33 Blade 34 Inclined surface 37, 38 Tapered wall 40 Discharge port 42 Gap 44 Collection pipe 48 Collection hopper 49 Bag filter 51 Suction fan 53 Rotary valve 54 Collection Valve 55 Recovery tank 59 Nitrogen piping 60 Cooler 61 Exhaust piping 62 Nitrogen supply device R Swivel area C Grinding area S Classification area

Claims (4)

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. , A classification region is formed in front of the second rotor blade, a swirling airflow is generated by rotation of the first rotor blade and the second rotor blade, and the raw material put into the swirl region is crushed and classified, and the crushed raw material An airflow type crusher that discharges fine powder,
An airflow type pulverizer characterized by comprising a raw material charging unit for charging a raw material into a swirl region and a swirl region inert gas introducing unit for introducing an inert gas into the swirl region.   2. An airflow pulverization apparatus according to claim 1, further comprising an inert gas recovery device that recovers the inert gas discharged together with the fine powder of the pulverized raw material and returns it to the swirl region inert gas introduction unit. Machine.   The airflow type pulverizer according to claim 1 or 2, further comprising a classification region front inert gas introduction portion for introducing an inert gas in front of the classification region.   4. An air flow system according to claim 3, further comprising an inert gas recovery device that recovers the inert gas discharged together with the fine powder of the pulverized raw material and returns the inert gas to the inert gas introduction portion in front of the classification region. Crusher.

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