JPH11333382A - Classifying method for granular body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve classifying performance by classifying about the particle diameter of a granular body and the spherical degree of the granular body using the difference of the coefficient of friction between the granular body and a slope in the case of classifying the metallic or non-metallic granular body by rotating a disk having a conical slope in a horizontal plain. SOLUTION: In the case of classifying the granular body by rotating the disk having conical slope in the horizontal plain, the friction force by the friction coefficient of the granular body sliding on the slope is generated in the direction reverse to the sliding direction and then, the change of the falling position of the granular body is selected large by setting the angle of the slope, the diameter of the disk, rotation speed of the disk or the like. When the particle diameter of the granular body is <=200 μm for example, the angle of the slope is setted to 10-30 deg. and the number of revolution of the disk is set to 30-62 rpm. Further and when the particle diameter of the granular body is >=200 μm, the angle of the slope is setted to 10-30 deg. and the number of revolution of the disk is setted to 15-120 rpm. The change of the falling position of the granular body to be classified is increased by this way.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for classifying metal or non-metallic powders and granules, and more particularly, to a method in which a disk having a slope inclined downward in a radial direction from a center of rotation is inclined in a horizontal plane. While rotating, near the top of the slope,
The present invention relates to a method for charging and classifying a metal or non-metal powder.

[0002]

2. Description of the Related Art Conventionally, when classifying metallic or non-metallic powder particles, the powder particles are dropped in a layered form, and when a wind is caused to flow through the falling layer, the drop position changes due to the difference in the way of receiving the wind depending on the particle diameter. The particle size of the granular material is classified by using the above method. Also,
The particle size of the granular material is classified by utilizing the fact that, when the granular material is put on the wind and the mixture passes through a bent portion of a pipeline, a flying position changes due to a difference in inertial force. In addition, a method of classifying fine particles and coarse particles by a difference in centrifugal force depending on the particle size using a cyclone has been adopted. In addition to these methods, a method of classifying the particle size according to the size of a mesh using a vibrating sieve is well known.

[0003]

However, in such a conventional classification method, the granules are merely divided into two types of particle sizes, and a zone containing a large amount of the granules having a certain particle size or more is divided into two zones. It is only divided into two zones containing a lot of particles smaller than the particle size.
And the former who uses the wind uses the wind,
How to get into the wind and the magnitude of the centrifugal force should be constant depending on the particle size, but it is easily affected by the instability of the wind flow,
Even with the same particle size, there is a difference in how to receive the wind and how to ride the wind,
There is a problem that the classification performance lacks stability. These facts can be applied to the classification of particles having a size of several hundred μm or more, for example, 300 μm or more, and particles having a particle size of 200 μm or less can hardly be classified by particle diameter.
For this reason, particles having a size of 200 μm or less are screened using a sieve or the like over a long period of time, or a conventional method having poor classification performance, particularly using a cyclone to perform shape classification. It is.

[0004] In the latter case using a vibrating sieve, clogging of the net and the like occur, and at present, the shape cannot be classified.

[0005] Further, with these methods, it is hardly possible to classify the degree of the spherical shape of the granular material. In addition, it is almost impossible to classify a zone containing a large amount of powder having a certain particle size.

The present invention has been made in order to solve the above-mentioned problem, and its object is to classify the particle size of the granular material into two types regardless of the size of the particle size, It is an object of the present invention to provide a method capable of classifying powders and granules falling within a certain particle size range and also classifying the degree of sphere of the powders and granules.

[0007]

Means for Solving the Problems To achieve the above object, a method for classifying a granular material according to the first aspect of the present invention is characterized in that when a metallic or non-metallic granular material slides on a slope, the slope is determined. Using the fact that the coefficient of friction between the powder and the granular material changes according to the diameter of the granular material when the surface roughness of the slope is the same, and also changes according to the degree of the spherical shape of the granular material, the rotation with the slope is also used. The present invention is characterized in that the drop position of the granular material is made flat by performing the process with a rotating disk, and the change is increased.

According to a second aspect of the present invention, there is provided a method for classifying a powder or a granule, wherein the metal or non-metal powder is slid on a slope, and the surface roughness of the slope is classified into a particle size. The height is determined so as to affect the degree of the spherical shape of the body, and the difference in the coefficient of friction between the slope and the granular material is greatly changed to be equal to or larger than the particle size to be classified.

According to a third aspect of the present invention, when the metal or non-metal powder slides on a slope, the frictional force due to the friction coefficient between the slope and the powder is reduced. Utilizing the fact that it occurs in the opposite direction of the slip direction,
Increase the change in the drop position of the granular material by setting one of the angles of the slope, the diameter of the disk, the number of rotations of the disk, or a combination of them, which changes the sliding direction depending on the particle size or spherical degree of the granular material. It is characterized by having done.

According to a fourth aspect of the present invention, there is provided a method for classifying a granular material, wherein when a metallic or non-metallic granular material slides on a slope, the frictional force due to the friction coefficient between the slope and the granular material is reduced. Utilizing the fact that it occurs in the opposite direction of the slip direction, the slip direction can be changed according to the particle size or spherical degree of the granular material, the slope angle, the disk diameter, the disk rotation speed, or any combination thereof. To set, the particle size of the powder is 200
When the pitch is equal to or less than μm, the angle of the inclined surface is set to 10 to 30 degrees, and the rotation speed of the disk is set to 30 to 60 rpm, so that the change in the drop position of the granular material is increased.

According to a fifth aspect of the present invention, there is provided a method for classifying a granular material, wherein when a metallic or non-metallic granular material slides on a slope, the frictional force due to the friction coefficient between the slope and the granular material is reduced. Utilizing the fact that it occurs in the opposite direction of the slip direction, the slip direction can be changed according to the particle size or spherical degree of the granular material, the slope angle, the disk diameter, the disk rotation speed, or any combination thereof. To set, the particle size of the powder is 200
When the diameter is equal to or more than μm, the angle of the slope is set to 10 to 30 degrees and the rotation speed of the disk is set to 10 to 120 rpm, so that the change in the drop position of the powder and granules is increased.

According to a sixth aspect of the present invention, when the metal or non-metal powder slides on a slope, the frictional force due to the friction coefficient between the slope and the powder is reduced. Utilizing the fact that it occurs in the opposite direction of the slip direction,
The angle of the slope, which changes its sliding direction depending on the particle size or spherical degree of the granular material, is gradually changed toward the outer periphery of the disk, so that the change in the drop position of the granular material is increased.

[0013] A method for classifying a powder or granular material according to the invention of claim 7
Is a metal or non-metal using a rotating disk with a slope
In the method of classifying the granular material of the
Select the diameter and the number of rotations of the disk, and select the particle size or
Using the coefficient of friction measured for each degree of spherical shape of the body,
The motion of the granular material from the initial position to the outer circumference is calculated as
Each time, calculate the drop position of the powder and the difference
Is set so that the particle size of the granular material and the granular material
Classify one or both of the degrees of sphere
It is characterized by that. gcosα (Fcosθ−μRcosε) / W = d
²X / dt² gcosα (F sin θ + μR sin ε) / W = d
²Y / dt² Here, g: acceleration of gravity α: inclination angle of the slope F: radial force applied to the granule particles along the slope θ: angle between the position of the granule particles and the fixed coordinate axis μ: slope and granules Coefficient of friction with the body R: Force applied perpendicular to the slope ε: Direction of the frictional force applied to the granular material particles and the fixed coordinate axis
Angle formed by the running surface W: Weight of granular material particles d²X / dt²  D²Y / dt²:acceleration

[0014]

Embodiments of the present invention will be described. FIG. 2 shows that the speed of the granular material at the lower end of the slope is calculated by the free fall motion from the falling position when sliding down the slope (FIG. 3) by changing the particle size of the granular material, and from the speed. Assuming that the potential energy at the initial position of the granular material slides on the slope in place of the kinetic energy, the rotational kinetic energy, and the energy lost by friction, the average friction coefficient of the granular material from the initial position to the lower end of the slope is calculated by the following equation. The result.

[0015]

(Equation 1)

A graph similar to that of FIG. 2 is obtained when the degree of sphere is changed at each nominal particle size of the powder. The lower the degree of sphere, the higher the friction coefficient.

As described above, the method of classifying one or both of the particle diameter and the spherical degree of the powder using the difference in the friction coefficient when the powder slides on the slope is as follows. It is possible in principle. However, when the particle size of the granular material becomes smaller on the slope of the fixed plate, the difference in the coefficient of friction is large, but the difference in the falling distance is small due to the difference in the area where the speed at the lower end of the slope is small. Actual classification is difficult.
For this reason, a method of changing the falling position on a two-dimensional plane has been considered. As shown in FIG. 4, there is also a method in which a flexible belt is moved to drop a granular material on a fixed position on the belt, and classification is performed based on a difference in a drop position from the belt. In this method, there is a problem that the belt shakes, and the angle of the slope always changes delicately, and there is a problem in stability of the falling position of the powder having the same particle diameter. For this reason, this method is used for classifying only particles having a poor degree of spherical shape, that is, particles that are carried with the belt on.

In the method according to the present invention, as shown in FIG. 1, the slope is made of a rigid body, the surface roughness thereof is limited to a certain range, and the disk is shaped so as to be rotatable. When the granular material is dropped to a fixed position on the rotating slope, the granular material moves on the slope according to the friction coefficient of the granular material and falls on the outer periphery of the disk. At this time, the peripheral speed of the disk increases as it goes to the outer periphery of the disk, so that the difference in the drop position due to the difference in the coefficient of friction appears more than when the constant speed of the belt or the like is used.

In FIG. 1, if the surface roughness of the slope is determined to be the particle size to be classified and the height to affect the degree of sphere of the granular material, the friction due to the difference in particle diameter or the degree of sphere is considered. The difference between the coefficients increases. Further, the difference between the drop positions appears, including that the peripheral speed of the disk increases as it goes to the outer periphery of the disk.

In FIG. 1, the frictional force due to the friction coefficient of the granular material sliding on the slope is generated in the direction opposite to the sliding direction, and the sliding direction is changed to the particle size or spherical shape of the granular material. If the data is collected by the degree, it is possible to select one of the angle of the slope, the diameter of the disk, the number of rotations of the disk, or a combination thereof to increase the change in the drop position of the granular material. When the particle size of the granular material is 200 μm or less, the angle of the slope is 10 to 30 degrees, and the rotation speed of the disk is 30 to 30 degrees.
If the rotation speed is 60 rpm, a change in the drop position of the powder or granule due to the difference between the particle diameter of the powder or the degree of sphere of the powder or granule can be increased.
When the particle size of the powder is 200 μm or more, the angle of the slope is 10 to 30 degrees, and the rotation speed of the disk is 15 to 120 rpm.
If m, the change in the drop position of the granular material due to the difference between the particle size of the granular material and the degree of the spherical shape of the granular material can be increased.

On the other hand, in FIG. 1, the frictional force due to the friction coefficient of the granular material sliding on the slope is generated in the direction opposite to the slip direction, and the angle of the slope is gradually increased toward the outer periphery of the disk. If the data is collected with the slip direction being the particle size or spherical degree of the granular material, the angle of the slope is gradually changed toward the outer periphery of the disk, and the change in the drop position of the granular material is increased. Can be selected.

From these results, as shown in FIG.
Angle, outer diameter of disk, number of rotation of disk and friction of powder
With the coefficient and the initial position of the granular material as variables,
The following equation was obtained by analyzing the movement.
Using this formula, the angle of the slope, the outer diameter of the disk, and the rotation of the disk
Select the number and for each particle size of the granular material or degree of spherical shape of the granular material
First drop the powder using the measured coefficient of friction
The movement of the powder from the initial position on the board to the outer circumference
Each time, calculate the drop position of the powder and the difference
Is set so that the particle size of the granular material and the granular material
Classify one or both of the degrees of sphere
It became possible to do. In this, the angle of the slope is
Instead of making it constant, change gradually as you go to the outer circumference of the disk
You can also. gcosα (Fcosθ−μRcosε) / W = d
²X / dt² gcosα (F sin θ + μR sin ε) / W = d
²Y / dt² Here, g: acceleration of gravity α: inclination angle of the slope F: radial force applied to the granule particles along the slope θ: angle between the position of the granule particles and the fixed coordinate axis μ: slope and granules Coefficient of friction with the body R: Force applied perpendicular to the slope ε: Direction of the frictional force applied to the granular material particles and the fixed coordinate axis
Angle formed by the running surface W: Weight of granular material particles d²X / dt²  D²Y / dt²:acceleration

[0023]

FIG. 5 shows an example of a test result and a result calculated from the above equation. FIG. 6 shows the weight distribution of 300, 100, and 50 μm dropped from each position on the outer shape of the rotating disk. The test conditions are as follows:
The outer diameter of the rotating disk was 300 mm. The degree of sphere of each particle in FIG. 6 was almost spherical, and the particles with poor degree of sphere fell at a position where the falling position was at an angle larger than these particles and deviated to the right of the graph in FIG. From these results,
When the particle size of the powder is 200 μm or less, 30 rpm or more, 6
It turned out that it is effective at 0 rpm or less. In addition, in a test in which the slope was separately changed, similar results were shown at an angle of 10 to 30 degrees. 10 rpm when the particle size of the powder is 200 μm or more
It was found to be effective at m or more and 120 rpm or less.
In addition, in a test in which the slope was separately changed, similar results were shown at an angle of 10 to 30 degrees.

The results in FIG. 5 show the slope angle, disk diameter,
Arbitrarily select the number of rotations of the disk, arbitrarily select the initial position on the disk using the friction coefficient measured for each particle size of the granular material or the degree of sphericalness of the granular material, and from that position to the outer periphery The motion of the granular material is integrated every minute time by the above formula, the falling position of the granular material is calculated, and it is shown that it is possible to set the difference so that the position is different. It is possible to classify one or both of the particle size and the degree of the spherical shape of the granular material.

[0025]

As is apparent from the above description, according to the present invention, the classification of the particle size of the granular material is not only divided into two types irrespective of the size of the particle size, but also classified into two types. In addition to classifying powders and granules that fall within the range, it is also possible to classify the degree of spheroids of the powders and granules, and it is also possible to classify fine powders and granules that had no method up to now. This has the effect of controlling the diameter and the degree of sphere within a certain range.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an embodiment of the present invention.

FIG. 2 is a graph showing actually measured values of a particle diameter and a friction coefficient used in the present invention.

FIG. 3 is a schematic view of the apparatus for measuring the coefficient of friction of FIG. 2;

FIG. 4 is a schematic view of a conventional method using a flexible belt.

FIG. 5 is a graph showing a drop position of a granular material according to a test result of an apparatus configured according to the present invention and a calculation result according to a calculation formula of the present invention.

FIG. 6 is a weight distribution graph showing test results on a device configured according to the present invention.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroaki Suzuki 3-1 Tonokawa, Toyokawa-shi, Aichi Pref.

Claims (7)

[Claims] 1. A method in which a metal or a non-metallic powder is charged and classified near a vertex of a slope while rotating a disk having a slope inclined downward in a radial direction from a center of rotation in a horizontal plane. A method for classifying one or both of the particle size of the granular material and the degree of the spherical shape of the granular material using a difference in friction coefficient between the granular material and the slope. Classification method. 2. The method of claim 1, wherein the friction between the granular material and the slope is changed by changing the surface roughness of the slope according to the particle size or the degree of sphere to be classified. A method for classifying powders and granules, wherein the difference between the coefficients is increased, and one or both of the particle size and the degree of sphere of the powders are classified. 3. A method in which a metal or a non-metal powder is charged and classified near a vertex of a slope while rotating a disk having a slope inclined downward in a radial direction from a center of rotation in a horizontal plane. By changing the angle of the slope, the diameter of the disk, one of the rotation speeds of the disk, or a combination thereof, by changing the direction of the frictional force of the granular material, or the magnitude thereof, A method for classifying a powder or a granule, comprising classifying one or both of the particle diameter of the body and the degree of the spherical shape of the granule. 4. The method for classifying a powdery or granular material according to claim 3, wherein when the particle size of the granularity is 200 μm or less, the angle of the slope is 10 to 30 degrees and the rotation speed of the disk is 30 to 60.
A method for classifying a powder or granule, wherein one or both of the particle size and the degree of spheroid of the granule are classified as rpm. 5. The method for classifying a granular material according to claim 3, wherein when the particle size of the granular material is 200 μm or more, the angle of the slope is 10 to 30 degrees, and the rotational speed of the disk is 10 to 12 degrees.
A method for classifying a powder or granule, wherein one or both of the particle size and the degree of spheroid of the powder and granule are classified at 0 rpm. 6. A method in which a disk having a slope inclined downward in a radial direction from a rotation center in a radial direction is rotated in a horizontal plane, and a metal or non-metal powder material is charged near the apex of the slope and classified. The angle of the slope is not fixed, but is gradually changed toward the outer periphery of the disk to change the direction of the frictional force of the granular material, or the magnitude thereof, to change the particle size of the granular material, A method for classifying a granular material, wherein one or both of the spherical degrees of the body are classified. 7. A slope inclined in a radial direction from the rotation center in a radial direction.
Rotating a disk with a sloping slope in a horizontal plane
Put metal or non-metallic powder near the top of the slope.
The angle of the slope, the disc
Select the diameter, the number of rotations of the disk, the particle size of the granular material or
Disk using friction coefficient measured for each degree of sphere of powder
The motion of the granular material from the initial position above to the outer periphery is expressed by the following equation.
Accumulates every minute time, calculates the drop position of the powder,
By setting so that there is a difference in position, the particle size of the granular material,
One or both of the degree of sphericalness of the powder
A method for classifying powders and granules, characterized by classifying the particles. gcosα (Fcosθ−μRcosε) / W = d
²X / dt² gcosα (F sin θ + μR sin ε) / W = d
²Y / dt² Here, g: acceleration of gravity α: inclination angle of the slope F: radial force applied to the granule particles along the slope θ: angle between the position of the granule particles and the fixed coordinate axis μ: slope and granules Coefficient of friction with the body R: Force applied perpendicular to the slope ε: Direction of the frictional force applied to the granular material particles and the fixed coordinate axis
Angle formed by the running surface W: Weight of granular material particles d²X / dt²  D²Y / dt²:acceleration