JP2001321684A - Mechanical air flow type pulverizer and mechanical air for pulverizing method of solid raw material using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the autogeneous pulverization efficiency by the collision and friction of particles to each other in a pulverizer and to prevent the contamination of a pulverized product. SOLUTION: The mechanical air flow type pulverizer is provided with a hollow rotary body type casing around a prescribed axis line, two rotary members houses respectively in the casing, facing each other to have a space between their front faces in the axis line direction, supported to have a space between the outer peripheral parts and the inside wall surface of the casing and driven to rotate in the direction opposed to each other, a passing passage penetrating the rotary members from the front face to the rear face in the axis line direction, a solid raw material supply port provided at a part facing the rear surface of one of the rotary members and for supplying the solid raw material and air to the casing from the outside, and a pulverized product discharge port provided a part facing the rear face of another rotary member in the casing and for discharging the pulverized product and a gas in the casing to the outside, and the attended air flows generated around respective rotary members by the rotation of the two rotary members are led toward the directions opposed to each other in the space between the front faces of the rotary members by the rotation of the rotary members in the direction opposed to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to electronic materials such as toners and silicon wafers, printed circuit board materials such as polyimides, semiconductor materials, resins such as synthetic resins, rubbers such as synthetic rubbers, metal oxides, and sulfides. Products and carbonates, rocks, foods such as soybeans and wheat, raw materials for catalysts, coal,
The present invention relates to a mechanical airflow pulverizer for finely pulverizing charcoal or the like by a dry method and a mechanical airflow pulverization method of a solid raw material using the pulverizer.

[0002]

2. Description of the Related Art In recent years, the demand for producing particles of several microns or submicrons by pulverization has rapidly increased, and contamination (contamination due to entry of foreign substances) of pulverized products has become extremely disliked. However, in a conventional crusher using a medium, such as a ball mill, a stirring mill, a vibrating mill, and a centrifugal mill, it is not possible to avoid mixing of foreign substances due to contact between the medium and the solid particles. Even if not, even in a mill such as a disc mill or a pin mill in which solid particles are in contact with a pulverizing accelerating body constituting the mill, foreign matters cannot be avoided.

On the other hand, as a pulverization method in which no foreign matter is mixed, that is, there is no contamination of the pulverized product, collision and friction between solid particles to be pulverized are performed.
There is a method called an autogenous grinding method or a homogenous grinding method.

However, in order to perform autogenous pulverization in a dry system, it is necessary to generate an air flow, accelerate solid particles by the air flow, and perform pulverization by collision and friction between particles. The best known type of dry autogenous pulverization is to accelerate solid particles by a jet stream, and a pulverizer is called a jet mill and a pulverization method is called a jet mill pulverization.

However, in such a jet mill pulverization, there is a problem that an extremely large energy consumption is required in order to generate a high-speed jet stream. In a jet mill, a high-speed jet stream is ejected from a limited opening in the inner wall of the milling chamber, so the concentration of solid material particles accelerated by the jet stream is low, and the milling efficiency of the entire mill deteriorates. there were.

Further, there are problems such as the inevitable wear of the jet airflow generating nozzle and the inner wall of the crushing chamber, and the generation of noise caused by the high-speed jet airflow, and are more energy efficient and environmentally friendly. The development of a pulverizer and a pneumatic pulverizer has been desired.

[0007]

Therefore, the first problem to be solved in the pneumatic pulverization in which an air flow is generated in the pulverizing chamber to accelerate the solid raw material particles and autogenous pulverization is performed by collision and friction between the particles. The problem to be solved is to reduce the energy consumption required for generating the airflow.

A second problem to be solved is to increase the number of solid particles present in the grinding chamber, and thus increase the particle concentration in the grinding chamber, thereby increasing the chance of collision and friction between particles. It is.

[0009] A third problem to be solved is to make the relative speed of the solid particles which are going to collide and rub against each other in the grinding chamber as large as possible.
No matter how fast the airflow is, if the solid particles to be pulverized are not efficiently accelerated by the airflow, the pulverization efficiency will decrease.

A fourth problem to be solved is to suppress the abrasion effect of the solid raw material particles in the crushing chamber and to prevent foreign matter from being mixed into the crushed product, that is, to prevent contamination of the product. It is to be.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and accelerates solid raw material particles in directions facing each other by a mechanically generated opposing airflow, thereby generating solid particles due to collision and friction between the particles. It is an object of the present invention to provide a mechanical pneumatic pulverizer for efficiently performing pulverization to produce a pulverized product composed of several micron to submicron particles, and a method of mechanical pneumatic pulverization of a solid raw material using the pulverizer.

[0012]

In order to achieve the above object, a mechanical air flow type pulverizer according to the present invention comprises:
While forming a hollow rotating body around the predetermined axis,
A casing having a smooth inner wall surface, and the casings are respectively housed in the casing, and the front surfaces are opposed to each other with a gap in the axial direction, and the outer peripheral portions are respectively supported so as to leave a gap with respect to the inner wall surface of the casing. And
Two rotating members that are driven to rotate in opposite directions about the axis, and are formed on the two rotating members, respectively, and penetrate the rotating members in the axial direction from the front to the back of the rotating members. A passage, and a solid material supply port that is provided at a portion of the casing facing a back surface of one of the two rotating members and that supplies a solid material and a gas into the casing from outside,
A pulverized product discharge, which is provided at a portion of the casing facing the back of the other rotatable member of the two rotatable members and discharges pulverized products and gas formed from the solid raw material to the outside in the casing. An outlet, which is generated around the rotating members by the rotation of the two rotating members, respectively, the passage, near the front surface of the rotating member, and a gap between the rotating member and the casing. By rotating the two rotating members in opposite directions, the circulating airflow circulating through the vicinity of the back surface of the rotating member is directed in the opposite direction to the gap between the front surfaces of the rotating members. Features.

[0013] In such a mechanical air flow type pulverizer, by the rotation of the two rotating members, each of which is rotationally driven, the passing path, the vicinity of the front surface of the rotating member, and A circulating air flow circulating through a gap between the rotating member and the casing and near the back surface of the rotating member is generated, and a circulating air flow around the two rotating members is generated by the two rotating members. By rotating in the opposite direction, the rotating members are directed in opposite directions in the gap between the front surfaces of the rotating members, so that if the solid raw material is supplied together with the gas from the solid raw material supply port into the casing, the solid raw material is converted into two solid raw materials. Riding on the swirling airflow generated around the rotating members, they enter the gap between the front faces of the rotating members, and are accelerated in opposite directions in the gaps. Crushed by the impact and friction between it becomes pulverized product, the milling products further ride the throwing airflow is discharged together with the gas to the outside of the casing from the milling products outlet.

Therefore, according to the mechanical air flow type pulverizer of the present invention, a pulverized product consisting of several micron or submicron particles can be produced by performing autogenous pulverization by collision and friction between particles, and furthermore, in the opposite directions. By accelerating the solid raw materials in directions opposite to each other in the airflow, the collision and friction of the solid particles can be efficiently performed, so that the energy consumption required for generating the airflow can be reduced.

Further, according to the mechanical airflow type pulverizer of the present invention, the solid raw material is put on the airflows in opposite directions, and the solid raw material is conveyed to the pulverizing chamber formed by the gap between the front surfaces of the two rotating members. Thus, it is possible to increase the number of solid particles present in the grinding chamber, and thereby improve the particle concentration in the grinding chamber, thereby increasing the chance of collision and friction between particles.

Further, according to the mechanical air flow type pulverizer of the present invention, by accelerating the solid raw materials in directions opposite to each other in the pulverizing chamber, the relative velocity of the solid particles which are likely to collide with and rub against each other is extremely increased. Can be
Thereby, the pulverization efficiency can be increased.

Further, according to the mechanical air flow type pulverizer of the present invention, since neither a medium nor a pulverization accelerating body which comes into contact with the solid particles is used, and a jet jet is not used, the abrasion effect in the pulverization chamber due to the solid raw material particles is eliminated. And the contamination of the crushed product with foreign substances can be prevented, and the generation of contamination of the product can be effectively prevented.

Further, using the mechanical air flow type pulverizer of the present invention,
The method of mechanically pulverizing a solid raw material according to the present invention, wherein the solid raw material supplied together with the gas from the solid raw material supply port into the casing is generated around the rotary members by rotating the two rotary members. And accelerated in opposite directions in the gap between the front surfaces of the rotating members, and crushed by collision and friction between the solid raw materials due to the acceleration to obtain a crushed product. It is characterized in that it is discharged together with gas from the discharge port to the outside of the casing.

According to the mechanical air flow pulverizing method of the present invention, various effects of the mechanical air flow pulverizer of the present invention described above can be obtained.

Here, a preferred embodiment of the mechanical air flow type pulverizer of the present invention will be described. The maximum rotation diameter of one rotating member is set to Di1, the maximum rotation diameter of the other rotating member is set to Di2, and each rotation member is set to Di2. The minimum diameter of the casing inner wall surface that intersects when the rotation surface (the plane perpendicular to the axis) of the largest diameter such as the front surface of the member is expanded in the radial direction is Dc1 and Dc2, respectively, and the boss in the rotation surface of the rotation member is When the porosity of the passage for the removed part is p1 and p2, respectively, and the ratio of the boss diameter to the maximum rotation diameter is q1 and q2, respectively, the following equation can be satisfied. preferable.

(Equation 1)

Further, the maximum diameter of the inner wall surface of the casing is represented by Dc
And the axial width (thickness) of the portion where the passage is provided of the two rotating members whose front surfaces are opposed to each other
Assuming w1 and w2 and the distance between the front surfaces of the two rotating members (the thickness of the air gap) as Li, it is preferable to satisfy the following [Equation 2].

(Equation 2)

Hereinafter, of the two rotating members whose front surfaces are opposed to each other, the rotating member on the raw material supply side is referred to as a first rotating member and the rotating member on the product discharging side is referred to as a second rotating member. The space surrounded by the front surfaces of the first rotating member and the second rotating member and the inner wall surface of the casing is called a crushing chamber.

In this pulverizer, a part of the solid raw material particles supplied into the casing receives an interaction between the air flow from the raw material supply side to the product discharge side and the air flow generated by the rotation of the first rotating member, It is necessary to move to the grinding chamber through the passage of the first rotating member, move to the inner wall surface of the casing by the action of centrifugal force, and return to the raw material supply side again.

For this purpose, it is desirable that the total area in the rotation plane of the passage of the first rotating member is larger than the minimum sectional area of the gap between the first rotating member and the inner wall surface of the casing. Therefore, the maximum rotation diameter of the first rotating member is set to Di1, the minimum diameter of the inner wall surface of the casing that intersects when the first rotating member maximum diameter rotation surface is extended is set to Dc1, and a portion excluding the boss portion in the rotation member rotation surface is set. Let p1 be the opening ratio of the passageway, and q1 be the ratio of the boss diameter to the maximum rotation diameter,
It is desirable that the following [Equation 3] be satisfied. Note that p1
And q1 can be arbitrarily set as required.

(Equation 3)

Another part of the supplied solid raw material particles is generated by the rotation of the second rotary member after passing through the passage of the first rotary member due to the airflow from the raw material supply side to the product discharge side. Under the influence of the air flow, it must pass through the passage of the second rotating member, move to the inner wall surface side of the casing under the action of centrifugal force on the product discharge side, and perform a motion showing a locus of returning to the grinding chamber again. There is.

For this purpose, it is desirable that the total area of the passage of the second rotating member in the rotation plane be larger than the minimum sectional area of the gap between the second rotating member and the inner wall surface of the casing. Accordingly, the maximum rotation diameter of the second rotating member is set to Di2, the minimum diameter of the inner wall surface of the casing that intersects when the second rotating member maximum diameter rotation surface is expanded is set to Dc2, and the portion excluding the boss portion in the rotation member rotation surface is set. P2 and the ratio of the boss diameter to the maximum rotation diameter is q2,
It is desirable that the following [Equation 4] be satisfied. Note that p2
And q2 can be arbitrarily set as required.

(Equation 4)

When the above conditions are satisfied for the first rotating member, the second rotating member, and the casing, the movement of the solid raw material particles is as shown by the arrows and dotted lines in FIG. Here, reference numeral 1 in FIG.
Is a gas inlet, 3 is a supply unit casing, 4 is a first rotating member, 5 is a crushing chamber, 6 is a crushing chamber casing, 7 is a second rotating member, 8 is a classifying chamber described later, 9 is a classifying chamber casing, 10
Is a pulverized product discharge port, 11 is a gas outlet, C is the first rotating member 4, the second rotating member 7, and the supply unit casing 3, which is a member constituting the casing, the grinding chamber casing 6, the center of the classifying chamber casing 9. The axes are indicated. That is,
The movement of the solid raw material particles is caused by the opposing particle flows of those moving from the center to the outside near the front surface of the first rotating member 4 and those moving from the outside to the center near the front surface of the second rotating member 7 in the grinding chamber 5. Since the rotating directions of the first rotating member 4 and the second rotating member 7 are opposite to each other, the opposing particle flows around the axis in the plane of rotation are overlapped, and the collision and friction between the solid particles are caused. For self-generated grinding.

In order to generate a plurality of opposed airflows in the grinding chamber and efficiently perform autogenous grinding by collision and friction between the solid particles, a further space between the front surface of the first rotating member and the front surface of the second rotating member is required. It is preferable to set the distance appropriately.

Therefore, the maximum diameter of the inner wall surface of the casing is represented by Dc
The two rotating members whose front faces are opposed to each other, the width in the axial direction of the portion where the passage is provided, respectively w1 and
Assuming that w2 and the distance between the front surfaces of the two rotating members are Li, the volume of the airflow portion swirling around the axis near the front surface of the first rotating member in the grinding chamber with the rotation of the first rotating member is The volume of the airflow portion which is proportional to the rotation volume of one rotating member and turns around the axis near the front surface of the second rotating member in the grinding chamber with the rotation of the second rotating member is equal to the rotating volume of the second rotating member. Since it is proportional, it is desirable to determine the distance Li so that the following equation (5) holds. Where k
Is a proportionality constant determined by the shape of the rotating member, and 0.3
It is preferable to set the range of ≦ k ≦ 1.3.

(Equation 5)

If the conditions are set as described above, the volume of the pulverizing chamber substantially matches the volume of the opposing airflow portion, and the airflow portions come into efficient contact with each other. By the opposed airflow, particles can be accelerated more efficiently, and energy consumption can be reduced. Further, since the particle concentration in the pulverizing chamber can be increased, the efficiency of spontaneous pulverization due to collision and friction between particles can be further improved.

Further, in the crusher of the present invention, the relative speed of the particles near the first rotating member and the second rotating member in the crushing chamber can be changed by the rotating speed of the first rotating member and the second rotating member. The crushing speed, and thus the throughput and the target particle size of the crushed product, can be appropriately controlled by changing the rotation speed of the rotating member.

The effects of the particle concentration and the relative velocity of the particles in the grinding chamber on the collision and friction between the particles can be explained by Maxwell and Boltzmann's theory of gas molecule kinetics.

Now, the particles have the same size and the diameter D,
The average relative velocity of the two particles is Vr, and the number of particles in a unit volume is n. Assuming that the positions and movement directions of the particles are uniformly distributed, the number of times Z that one particle collides with another particle in a unit time is Z = πD · Vr · n. Further, assuming that the average velocity of the particles is V, according to the gas molecule kinetics, Vr = 2 ^1/2 · V.

Assuming that the porosity in the grinding chamber is e, the following holds: n = 6 (1-e) / (πD ³ ). Therefore, the total number of collisions per unit volume per unit time in the crushing chamber is given by Z · n = 36 · ^21/2 · V · (1-e) ² / (πD ⁴ ).

From the above, it can be seen that the number of times particles contact each other in the crushing chamber is proportional to the particle speed, and thus changes in proportion to the rotation speed of the rotating member and also in proportion to the square of the particle concentration. According to the mechanical air flow type pulverizer of the present invention, both can be controlled independently by controlling the rotation speed of the two rotating members and adjusting the distance between the two rotating members.

In crushing by collision and friction between particles accelerated by an air flow, the kinetic energy of the particles is used as crushing energy. Now, let the masses of two spherical particles moving on the same straight line be M1 and M2, and the velocities be V1 and V2. According to the law of conservation of mass, u = (M1 · V1 + M2 · V2) / (M1 + M2) according to the law of conservation of mass.

Accordingly, assuming that the difference between the kinetic energies before and after the collision is E, E = M1 · M2 · (V1−V2) ² / {2 · (M1 + M2)} is the energy that can be used for grinding the particles.

Considering the total number of collisions of the particles in the grinding chamber per unit time and unit volume, the total energy consumption per unit time and unit volume ΣE used for grinding by the collision of the particles is as follows: Equation 6].

(Equation 6)

Here, assuming that the density of the particles is ρ, M1 = M2
^{= ΠρD 3/6, V1 =} -V2 = because it is V,? En = by ^{6 · 2 1/2 · ρV 3 (} 1-e) 2 / D, the total energy available to the pulverized per unit time and unit volume Is found.

That is, it can be seen that the energy available for the pulverization of the solid raw material particles is proportional to the speed of the particles, and thus to the cube of the rotation speed of the rotating member, and changes in proportion to the square of the particle concentration. According to the mechanical air flow type pulverizer of the present invention, since the rotation speed and the particle concentration of the rotating member can be controlled independently, the energy available for pulverization can be freely changed, and a product having a target particle size can be easily generated. .

In the mechanical air flow type pulverizer of the present invention, the solid particles can be efficiently accelerated by the plurality of opposing air flows as described above, so that the rotating member and the casing hardly come into contact with the solid particles, and therefore, there is almost no contact in the pulverizing chamber. There is no abrasion, no foreign matter mixed into the pulverized product, and no risk of contamination.

The space on the product discharge side of the second rotating member is a space for separating particles smaller than the target particle size discharged as a product and particles coarser than the target particle size circulating again in the grinding chamber. Call. In the classification chamber, an axial method airflow from the raw material supply side to the product discharge side, a circulating airflow circulating through the second rotating member, and a swirling airflow circling around the axis with the rotation of the second rotating member. There are three types of airflow.

That is, in the classification chamber, the inertial classification of the particles in the flow field where the above three types of air flows exist is performed. Therefore, when the axial air velocity is increased, coarse particles enter the product and the average particle size of the pulverized product increases.
Also, when the rotation speed of the second rotating member is increased, the centrifugal force acting on the particles increases, and finer particles are included in the product, so that the average particle size of the pulverized product decreases. Furthermore, when the gap between the second rotating member and the casing inner wall surface is narrowed, the circulating airflow velocity increases and the average particle size of the pulverized product decreases, but when the passage resistance of the gap becomes too large, As the circulating air velocity decreases, the average particle size of the product increases.

As described above, by controlling the air flow in the classification chamber, the average particle size of the pulverized product can be adjusted. However, when the turbulence occurs in these airflows, the accuracy of the inertial force classification is reduced. Therefore, it is necessary to consider the shape of the airflow passages. In order to generate a stable circulating airflow without turbulence, the second rotating member is required. Rotation surface of the classification room side (rear)
It is desirable that the angle between the rotating surface and the inner wall surface of the casing radially outward is 40 degrees or more and less than 90 degrees, more preferably 45 degrees, as an angle on a section passing through the axis.

The same applies to the circulating airflow around the first rotating member. In order to suppress the turbulence of the airflow as much as possible, the rotating surface (back surface) of the first rotating member on the raw material supply side and the rotating surface of the rotating surface. An angle between the radially outer casing inner wall surface and an angle on a cross section passing through the axis is not less than 40 degrees and 90 degrees.
It is desirable that the angle be less than 45 degrees, more preferably 45 degrees.

[0046]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 2 shows a basic structure of a preferred embodiment of the mechanical air flow type pulverizer of the present invention. The pulverizer of this embodiment has a solid material supply port 1 like the one shown in FIG. Gas inlet 2, supply unit casing 3, first rotating member 4, crushing chamber 5, crushing chamber casing 6, second rotating member 7, classifying chamber 8, classifying chamber casing 9, crushed product outlet 10, and gas outlet 11 And a first rotating member supporting shaft 12 and a second rotating member supporting shaft 13. Here, the solid material supply port 1
The gas inlet 2 is formed by one passage, and the pulverized product outlet 10 and the gas outlet 11 are formed by one passage. The first rotating member supporting shaft 12 and the second rotating member supporting shaft 13 are rotatably supported so as to be aligned on the center axis C, and are independently driven by two driving means (not shown) to rotate around the axis C. Rotate in opposite directions to each other. In the embodiment shown in FIG. 2, the conical supply unit casing 3, the cylindrical pulverizing chamber casing 6, and the conical classifying chamber casing 9 are axially moved from the raw material supply side to the product discharge side in the axial direction. Although the casing is configured by combining two casing members, the casing may be configured by combining an elliptical or spherical casing member in addition to these shapes.

FIGS. 3A to 3E are front views illustrating the shapes of the first rotary member 4 and the second rotary member 7 as viewed from the front, and show the first rotary member 4 and the second rotary member. 7
Is formed into a wheel shape or a blade shape of a blower as in these examples, thereby forming passageways 4a and 7a penetrating from the front surface to the rear surface in the axial direction. Further, the first rotating member 4 and the second rotating member 7 may have a turbine blade shape that generates a propulsive force.

FIG. 4 shows another embodiment of the mechanical air flow type pulverizer according to the present invention. In this embodiment, in addition to the basic structure shown in FIG. 2, each casing part has a hollow having an outer wall and an inner wall. The cooling fluid flow path 14 is provided between the outer wall and the inner wall as a cooling fluid flow path 14. The cooling fluid supply port 1 is provided at different positions on the outer wall of the casing.
5 and a cooling fluid outlet 16 are mounted therethrough. According to this embodiment, the cooling fluid supply port 15
And the cooling fluid flow path 1 via the cooling fluid outlet 16
By circulating the cooling fluid in the casing 4, the casing can be cooled, and the softening and fusion of the particles due to the heat generated by the collision and friction between the particles in the crushing chamber 5 can be effectively prevented.

FIG. 5 shows still another embodiment of the mechanical air flow type pulverizer according to the present invention. Here, the diameter of the inner wall surface of the pulverizing chamber casing 6 is not constant in the axial direction, but is the maximum diameter and the minimum diameter. There is a diameter. In the example shown in FIG. 5, since the diameter of the central portion of the crushing chamber 5 is small, the flow of the particles circulating around the first rotating member 4 and the second rotating member 7 is stabilized.

By stabilizing the flow of particles circulating around the first rotating member 4 and the second rotating member 7, the first rotating member 4
Extreme intrusion of particles from the side to the second rotating member 7 side,
In order to prevent the particles from entering from the second rotating member 7 side to the first rotating member 4 side extremely, the center of each of the rotating members 4 and 7 is shown in FIG. It is effective to attach conical enlarged portions 17 and 18 for preventing straying as shown in FIG. In addition, in order to prevent getting lost,
The enlargement does not necessarily have to be conical, for example it may be trumpet tubular.

Further, in order to prevent the coarse particles from getting into the pulverized product in the classifying chamber 8, the second rotating member 7 is provided on the classifying chamber 8 side as shown in FIG. It is effective to mount the conical enlarged portion 19 of FIG. In order to prevent straying, the enlarged portion does not necessarily have to be conical, and may be, for example, a trumpet tube.

As for the shapes of the first rotating member 4 and the second rotating member 7, as shown in FIG. 3, it suffices that each of the first rotating member 4 and the second rotating member 7 have a passage in the rotating plane, and the rotating members need to have the same shape. There is no. In addition, the in-rotational aperture ratios of the passages of the rotating members can be set independently of each other, and need not be the same. The diameters of the rotating member bosses can also be set independently of each other, and need not be the same.

Further, the gas flow from the gas inflow side to the gas discharge side may be generated by blowing in from the inflow side, or may be generated by sucking out from the discharge side. It does not affect the generation of opposing air flow, the direction of particle movement, and the self-crushing due to collision and friction between particles. Then, the solid material supply port and the gas inlet may be provided separately, or the pulverized product discharge port and the gas discharge port may be provided separately.

FIGS. 7, 8 and 9 are front views showing a more specific embodiment of the mechanical air flow type pulverizer according to the present invention.
It is a plan view and a side view, in which a ring of a conical supply section casing 3, a cylindrical grinding chamber casing 6, and a conical classification chamber casing 9, which are three rotating body casing members separated from each other, is shown. The casing 20 is formed by inserting and connecting a packing material and the like, a crusher is mounted on a normal slide mechanism 21, and the casing 20 is divided at the supply section casing 3 and the supply section casing 3 is slid. By doing so, it is possible to easily set the conditions inside the mechanical air flow type pulverizer, such as changing the rotating members 4 and 7, changing the distance between the rotating members, and replacing the liner 22 that is detachably attached to the inner wall surface of the casing, and is thus replaceable. ing. Reference numerals 23 and 24 in FIG. 7 denote motors that separately and independently drive the first rotating member 4 and the second rotating member 7.

Further, although not shown, the present invention has a single solid raw material supply port for supplying a solid raw material and a gas inflow, and a single ground product discharge port for discharging a pulverized product and a gas. Embodiments in which a plurality of basic structures of a mechanical air flow type pulverizer are connected in series or in parallel are also included.

[0056]

Examples Examples of pulverizing solid particles using the mechanical air flow pulverizer and the mechanical air flow pulverizing method according to the present invention will be described below. In this example, a mechanical air flow type pulverizer having the following dimensions was used. In addition, the rotation directions of the first rotating member and the second rotating member were set to be opposite to each other, and the rotation speeds of the first rotating member and the second rotating member were made equal to each other.

Casing: Stainless steel hollow double structure, comprising a supply section casing (conical), a pulverizing chamber casing (cylindrical), and a classifying chamber casing (conical) Pulverizing chamber casing inner diameter: 260 mm First rotating member Rotation diameter: 250 mm Second rotation member rotation diameter: 250 mm First rotation member rotation width: 35 mm Second rotation member rotation width: 35 mm Opening ratio in the first rotation member rotation plane: 0.62 Second rotation member rotation plane opening Porosity: 0.62 Distance between rotating member front faces: 25 mm Solid material supply port diameter: 60 mm Crushed product discharge port diameter: 100 mm First rotating member supporting shaft diameter: 65 mm Second rotating member supporting shaft diameter: 65 mm

FIG. 10 shows that the rotation speed of the first rotating member and the second rotating member is changed so that the particle diameter is 0.6 mm to 1.2 mm.
4 shows the particle size distribution of the crushed product when crushed ferrite of mm. The gas flow rate from the solid raw material supply side to the product discharge side is 5 m ^{3 /} min, and the ferrite supply rate is 1 h / hour.
It was 5 kg. Assuming that the particle size at which the integrated weight ratio of the passing amount is 0.5 is defined as the average particle size, as can be seen from FIG. 10, a pulverized product having an average particle size of several microns to submicron can be produced. From this result, it was found that the average particle size of the pulverized product changes in inverse proportion to the third power of the rotation speed, and it is considered that the rotation speed of the rotating member is proportional to the movement speed of the particles. The inventive mechanical airflow grinding theory has been demonstrated.

FIG. 11 shows that the particle size is 0.6 mm to 1.2 mm.
4 shows the particle size distribution of the crushed product when pulverizing silicon carbide by changing the gas flow rate while setting both the rotation speeds of the first rotating member and the second rotating member to 6000 rpm. The supply amount of silicon carbide was 18 kg / hour. Silicon carbide is one of the extremely difficult-to-grind substances having a very abrasive property.
When the wear state of the crushing chamber after the continuous operation was examined, no trace of wear was found on the inner wall surface of the stainless steel casing, and the inner wall surfaces of the first rotating member and the second rotating member were slightly exposed to the outer peripheral edges. Abrasion was observed. FIG. 11 also shows that the mechanical air flow type pulverizer of the present invention can produce a pulverized product having an average particle size of several microns or less even for a substance that is difficult to pulverize, such as silicon carbide.

Finally, an example of a pulverization test performed for the purpose of recycling a raw material from a silicon wafer unsuitable for inspection will be described. In recent years, the production of silicon wafers has been increasing, but the amount of defective products has also been increasing at the same time, and there is a pressing need for recycling. Conventionally, although submicron particles can be produced to some extent by wet pulverization, the submicron classification by wet method has not been successfully performed, and the recycling efficiency has been extremely low. On the other hand, as a result of performing the mechanical air flow pulverization of the present invention using a material obtained by coarsely pulverizing the defective silicon wafer to 3 mm or less, a pulverized product having an average particle diameter of 0.79 μm was obtained. Also, considering that all the crushed product particles are 3 μm or less and that the dry sub-micron classification is relatively simple, the recycling efficiency of the silicon wafer manufacturing process can be considerably improved according to the present invention. It has been found.

[0061]

According to the mechanical air flow pulverizer of the present invention and the method of mechanical air flow pulverization of a solid raw material using the same, the rotating members whose front surfaces are opposed to each other are rotated in the opposite manner, so that the pulverizing chamber is rotated. Can generate a counter-current air flow, which can easily accelerate the solid raw material particles, so that the efficiency of autogenous pulverization due to collision and friction between particles can be increased, and the energy consumption for pulverization can be reduced. it can.

Therefore, the power consumption of the pulverization process, that is, the power consumption per unit processing amount is reduced, the production cost of the pulverized product can be reduced, and the product price is reduced. Can expand the possibilities of new product development.

In addition, the particle concentration in the grinding chamber can be increased, and effective collision and friction between the particles can be performed in the entire grinding chamber, and the particle kinetic energy can be efficiently converted into the grinding energy. It is possible to increase the throughput quickly and at the same time, it is possible to reduce the size of the crusher itself,
The production cost of the crusher can be reduced.

Further, the moving speed of the particles can be changed by changing the rotating speed of the rotating member, and the energy available for pulverization changes in proportion to the cube of the moving speed of the particles. The crushing alone can greatly change the average particle size of the crushed product, thereby greatly simplifying the operation of the crusher and reducing the operating cost.

In addition, since solid materials which can be pulverized by a wet method but difficult to pulverize by a dry method can be pulverized to several microns or sub-microns, it is possible to perform dry classification with higher classification accuracy than wet classification. In combination, a product recovery process can be constructed to improve the recovery of the milled product.

In addition, since there is almost no contamination of the pulverized product, fine particles such as toner and electronic materials of high quality can be produced by dry pulverization, which is one of the simplest unit operations. And lower product prices.

Finally, in order to improve the recycling rate for the construction of a recycling-oriented society, it is necessary to separate the constituent substances in the waste into individual substances. Since the present invention can be applied to raw materials, the applicable range of the present invention has been widely expanded in the field of material recycling.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a motion trajectory of solid particles in a pulverizer in one embodiment of a mechanical air flow type pulverizer of the present invention.

FIG. 2 is a cross-sectional view schematically showing a basic structure of one embodiment of a mechanical air flow type pulverizer of the present invention.

FIG. 3 is a front view showing various examples of the shape of a rotating member in the mechanical air flow type pulverizer of the present invention.

FIG. 4 is a cross-sectional view schematically showing a mechanical airflow type pulverizer having a double-structure casing for flowing a cooling fluid, which is another embodiment of the mechanical airflow type pulverizer of the present invention.

FIG. 5 schematically shows a mechanical air flow type pulverizer according to still another embodiment of the present invention, in which a pulverizing chamber casing of a double structure casing has a maximum diameter and a minimum diameter. It is sectional drawing.

FIGS. 6A and 6B are explanatory views schematically showing a first rotating member and a second rotating member to which conical enlarged portions for preventing particles from entering between rotating members are attached.
(A) shows a rotating member having a shape obtained by cutting one surface of an outer periphery, (b) shows a rotating member having a shape obtained by cutting both surfaces of an outer periphery, and (c) shows a method for preventing coarse particles from entering into a crushed product. It is explanatory drawing which shows the state which attached the conical enlarged part to the 2nd rotating member.

FIG. 7 is a front view showing a more specific embodiment of a mechanical air flow type pulverizer according to the present invention.

FIG. 8 is a plan view showing the mechanical air flow type pulverizer of the embodiment.

FIG. 9 is a side view showing the mechanical airflow type pulverizer of the embodiment.

FIG. 10 is an explanatory diagram showing a particle size distribution of a ferrite pulverized product pulverized by the mechanical air flow pulverizer of the present invention.

FIG. 11 is an explanatory diagram showing a particle size distribution of a silicon carbide pulverized product pulverized by the mechanical air flow pulverizer of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 solid material supply port 2 gas inlet 3 supply section casing 4 first rotating member 4a, 7a passage 5 crushing chamber 6 crushing chamber casing 7 second rotating member 8 classifying chamber 9 classifying chamber casing 10 crushed product outlet 11 gas flow Outlet 12 First rotating member support shaft 13 Second rotating member support shaft 14 Cooling fluid flow path 15 Cooling fluid supply port 16 Cooling fluid outlet 17, 18, 19 Conical enlarged portion 20 Casing 21 Slide mechanism 22 Liner 23 , 24 Motor C center axis

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[Procedure amendment]

[Submission date] May 19, 2000 (2005.1.
9)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Name of invention

[Correction method] Change

[Correction contents]

Patent application title: Mechanical air flow pulverizer and method of mechanical air flow pulverization of solid raw material using the pulverizer

Claims (7)

[Claims] A casing (3) having a hollow rotating body around a predetermined axis and having a smooth inner wall surface.
6, 9) are respectively accommodated in the casing, the front faces are opposed to each other with a gap in the axial direction, and the outer peripheral portions are respectively supported so as to leave a gap with respect to the inner wall surface of the casing. Two rotating members (4, 7) that are driven to rotate in opposite directions about an axis; formed on the two rotating members, respectively; A passage (4a, 7a) penetrating in the direction, and a portion of the casing facing a back surface of one of the two rotating members, and a solid material and a gas are externally supplied into the casing. A solid material supply port (1, 2) to be supplied, and a casing provided in a portion of the casing facing a back surface of the other rotating member of the two rotating members. A pulverized product outlet (10, 11) for discharging pulverized products and gas formed from the solid raw material to the outside,
The passageway, the vicinity of the front surface of the rotating member, a gap between the rotating member and the casing, the rotation path being generated around the rotating members by the rotation of the two rotating members, respectively, A circulating air flow circulating through the vicinity of the back surface of the member is directed in opposite directions in a gap between the front surfaces of the two rotating members by rotation of the two rotating members in opposite directions. , Mechanical air crusher. 2. The sum of the thicknesses of the opposing circulating airflows generated around the rotating members by the rotation of the two rotating members, respectively, on the front side of the rotating members, is the rotation of the rotating members. 2. The machine according to claim 1, wherein the thickness of the gap is equal to the thickness of the gap between the front surfaces of the members, and the thickness of the two rotating members in the axial direction is set with respect to the thickness of the gap. Air flow type crusher. 3. An angle of a radially outer portion of the rear surface of the casing with respect to the rear surface of at least one of the two rotating members in a cross section passing through the axis is 4 degrees.
The said part of the said casing is inclined so that it may become more than 0 degree and less than 90 degree, The said 1st aspect is characterized by the above-mentioned.
Or a mechanical air flow type pulverizer according to 2 above. 4. The cooling device according to claim 1, wherein the casing has a double structure having an outer wall and an inner wall, and a gap between the outer wall and the inner wall is a flow path of a cooling fluid. The mechanical airflow pulverizer according to any one of the above. 5. The apparatus according to claim 1, wherein the casing includes a plurality of casing members which are aligned in the axial direction and are separably coupled to each other in the axial direction.
A mechanical air flow type pulverizer according to any one of claims 1 to 4. 6. The mechanical air flow type pulverizer according to claim 1, wherein at least a part of an inner wall surface of the casing is formed of a replaceable liner. 7. A solid raw material supplied together with a gas into the casing from the solid raw material supply port by using the mechanical air flow type pulverizer according to any one of claims 1 to 6, by rotating the two rotating members. On the circling airflow generated around each of the rotating members, respectively, accelerated in opposite directions in a gap between the front surfaces of the rotating members,
Mechanical air flow pulverization method of the solid raw material, characterized in that the solid raw material is pulverized by collision and friction between the solid raw materials due to the acceleration to produce a pulverized product, and the pulverized product is discharged from the pulverized product discharge port together with gas to the outside of the casing. .