JP2741801B2 - Powder divided sampling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for dividing and collecting powder, and more particularly, to measuring a particle size distribution of powder, from a total amount of powder to a small amount of powder sample required for measurement. The present invention relates to an apparatus that separates and collects only a sample.

[0002]

2. Description of the Related Art When manufacturing chemicals, molding materials and other various powders, the particle size distribution and other properties of the obtained powders are sometimes measured. In this case, the amount of the powder sample required for the measurement is a small amount compared to the total amount of the manufactured powder. Therefore, it is necessary to divide and collect only a small amount of powder sample required for measurement from a large amount of powder.

In any part of the whole powder, if the powder sample has the same properties, it is only necessary to take out the powder sample from an appropriate position on the whole powder. However, in practice, the properties of the first manufactured powder and the last manufactured powder may be different. In addition, while the powder is being transported or stored, the particle size distribution of the powder may be biased depending on the location due to the influence of vibration or the like.

[0004] Therefore, it is necessary to uniformly collect the powder from each part of the entire powder and to make the obtained powder sample accurately represent the properties of the entire powder. Dividing and collecting a powder sample in this manner is also called shrinkage, and various methods and apparatuses have been developed. For example, if powder is dropped and supplied to the container partitioned at the center so that the powder is distributed to the left and right of the container with the upper part of the partition as the center, the powder accumulated on the left and right of the partition is evenly distributed. It is divided into two. By repeating such division many times, it is possible to take out only a required amount of powder for measurement, and the taken-out powder is representative of the properties of the whole powder. This is usually called a sorting method.

Further, a flat dish-shaped container is divided into six by radial partitions, and powder is dropped and supplied to the upper portion of the container while rotating the divided containers. The particles are equally divided and accumulated, and the powder in one section may be used as a measurement sample. Such a device is called a rotary divider or the like. As an even better reduction method, Japanese Patent Application Laid-Open No. 59-90639 discloses a rotating body rotating about a predetermined axis and a sample formed on the rotating body and to be reduced. Disclosure is given of a decomposer each having an aperture for selectively passing according to a ratio. In this prior art, the reduction ratio can be continuously changed by changing the drop position of the sample on the turntable in the radial direction.

[0006]

However, the above-described conventional methods and apparatus for dividing and collecting powder each take a long time, and in particular, separate and collect a very small amount of a measurement sample from a large amount of powder. When it is necessary to do so, there is a problem that it takes a lot of time. In the case of the above-mentioned sorting method, if the powder is dropped quickly and in large quantities and is to be distributed to the left and right, the amount of powder on the right and left tends to vary, so the powder is dropped and supplied little by little and carefully distributed to the left and right. It requires a long working time and requires skill in the work. Also, for example, 600
In the case where 10 g of a measurement sample is to be divided and collected from g powder, the above-described sorting method requires only one operation to divide the powder into half, so that a total of six operations must be repeated.

[0007] In the above-mentioned rotary divider, work can be performed more efficiently than in the above-mentioned sorting method.
When the division ratio is increased, for example, when the division into 1/60 is performed for 0 g, it takes much time and effort. this is,
The number of divided sections of the divided container is only about 6 as described above, and increasing the number of divided sections to 60 is extremely difficult in manufacturing, and also increases the variation among divided sections. It is. In addition, if the number of rotations of the rotary divider is increased, the powder can be divided even if the amount of powder falling per unit time is increased. The body jumps out and the amount of powder in each divided section also varies. As described above, when it is attempted to divide a large ratio quickly with a rotary divider, it is difficult to divide the powder evenly, so that the divided and sampled measurement sample can accurately represent the properties of the entire powder. Measurement accuracy is reduced. Further, in a divided container having a large number of divided sections, taking out the powder is troublesome, and cleaning the divided container to which the powder adheres after the operation is very troublesome.

Further, in the conventional divided sampling method, the powder is dropped and supplied above a large-area container provided with a partition, so that the powder scatters around, or scatters in the air. There is a concern that it will adversely affect the surrounding environment and workers. It also takes up space for installation and operation of the device. In particular, when the number of divided sections is increased by the rotary divider, the area of the divided container becomes very large, so that the apparatus becomes large and a large installation space is required. It is possible to enclose the entire device or the working space with a partition wall to prevent the powder from scattering to the outside, but it is difficult to isolate the entire device such as the above-mentioned divided container with a large area. , Costly.

In the above-mentioned prior art disclosed in Japanese Patent Application Laid-Open No. 59-90639, there is a limit to the reduction ratio that is naturally possible because the sample supply device is moved on a graduated support rod to determine the reduction ratio. Furthermore, it cannot be denied that an example of the operation for determining the reduction ratio is complicated. In addition, for the unnecessary sample after the reduction,
Although a fall is prevented by providing a wall or the like, there is a problem that this measure limits the amount of a sample that can be subjected to one reduction operation.

[0010] Therefore, an object of the present invention is to provide a method for accurately and quickly dividing and collecting only a very small amount of a measurement sample from a large amount of powder, and a small-sized apparatus for preventing powder from scattering around. It is to provide a divided sampling device.

[0011]

According to a first aspect of the present invention, there is provided a powder dividing and sampling apparatus according to the present invention, comprising a cylinder installed with an axial line extending vertically, and an axial line inside a cylindrical body. Means for continuously supplying and dropping the powder at a position deviated from the center portion including the inside of the cylindrical body, a portion rotating around the axis of the cylindrical body and traversing the falling path of the powder. A rotating body having a powder passage portion, a powder collecting pipe provided below the rotating body, one end of which opens directly below a powder falling path and the other end of which opens outside the cylindrical body; A powder recovery path for recovering the powder shaken off from the upper surface of the body.

The cylindrical body is installed so as to surround the entire area where the operation from dropping and supplying the powder to collecting the sample to be measured and collecting the remaining powder is performed. As the cylindrical body, a cylindrical one is used from the viewpoint of installation of a rotating body described later and manufacturing problems. In the upper part where the powder is supplied and dropped, the upper surface may be open as long as it surrounds the periphery of the powder falling path at a height that does not cause the powder to scatter, If the lid is covered except for the portion through which the powder passes, scattering of the powder can be more reliably prevented.

The means for continuously supplying and dropping the powder may be the same as the various kinds of drop supplying means employed in the ordinary powder processing apparatus, such as by allowing the powder to fall naturally from a funnel-shaped hopper or by a vibration feeder. Or from the end of a screw feeder or conveyor. However, the discharge port of the powder from the powder drop supply means needs to be opened below the upper end of the cylindrical body. The smaller the distance between the discharge port of the powder and the rotating body, the less the possibility of the powder being scattered. It is preferable that the powder falling supply means itself is provided with a hermetically sealed structure for preventing the powder from scattering. It is preferable that the powder is allowed to fall only in a range that is slightly smaller than the opening area of the powder collecting tube described below. For this purpose, the diameter of the discharge port of the powder drop supply means may be set to be substantially the same as the diameter of the powder collection tube.
The amount of powder dropped and supplied per unit time can be changed by changing the diameter of the discharge port of the hopper or adjusting the operation speed of the vibration feeder or the like.

The rotator is installed below the powder supply means, and rotates in a plane crossing the path from which the powder falls. The rotating body may rotate in a horizontal plane or in a plane inclined to some extent. That is, it is sufficient that the rotating body is provided in such a manner as to block the falling of the powder. Rotary driving means such as a motor is connected to the rotating body. The rotation driving means may be installed either below or above the rotating body, but at a position where it does not hinder the falling or collection of the powder, and the falling powder does not enter the gap of the rotating mechanism. It is preferable to provide such a structure.

The number of rotations of the rotating body must be higher than the number of rotations at which powder placed on the rotating body is easily shaken off by centrifugal force or the like accompanying rotation of the rotating body. The specific value of the number of revolutions varies depending on the processing conditions such as the diameter of the rotating body and the falling flow rate of the powder.

The rotating body usually has a disk shape.
Polygons other than a disk and other plate shapes may be used. It is preferable that a sufficient gap is provided between the rotating body and the inner wall of the cylindrical body so that the powder placed on the rotating body can drop downward from the outer periphery of the rotating body. The rotating body may be a flat plate-shaped one, or may be a hat-shaped or conical-shaped one inclined so as to become lower toward the outer peripheral side.
As described above, when the rotating body is inclined toward the outer periphery, the powder placed on the rotating body is liable to slip, which is preferable because the powder does not remain on the rotating body.

The rotating body is provided with a powder passage portion by cutting out a part of the rotating body or making a through hole.
The powder passage section is provided at a position where it passes above the powder collection tube when the rotating body rotates. The shape of the powder passage section is fan-shaped with the rotating body cut out at a certain angle in the circumferential direction, but the manufacturing process is easy and the division ratio can be set easily. Other holes may be used. The powder passage section may be provided only at one place, but may be provided at a plurality of places.

By appropriately designing the area of the powder passage portion, particularly the opening angle of the notch or the width in the circumferential direction,
The division ratio of the powder can be arbitrarily set. If the opening angle and width of the powder passage section are changeable,
The division ratio of the powder can be freely changed according to the application. For example, in order to change the opening angle of the powder-passing portion forming a fan shape, two semi-circular plates can be combined so as to be rotatable around the center, and if the amount of superposition of the semi-circular plates is adjusted, the semi-circular plates can be changed. The fan-shaped gap formed between the end sides, that is, the opening angle of the powder passage portion can be freely adjusted. In addition, a slidable auxiliary shielding plate is attached so as to cover the powder passage portion, and the area of the powder passage portion can be changed by adjusting the position of the auxiliary shielding plate.

A powder collecting tube is provided below the rotating body. The powder collecting tube is opened just below the powder falling path. The opening area of the powder collecting tube may be set to such an extent that the powder to be divided and collected can pass smoothly. It is preferable that the upper end of the powder collecting tube is close to the rotating body so as not to contact the lower surface. The lower end of the powder collection tube is disposed inside or outside the cylindrical body so as to open above a collection container that stores the collected powder.

In the cylindrical body, below the opening of the powder collecting tube, there is provided a powder collecting passage for collecting the powder dropped to a place other than the powder collecting tube. Since the powder falls downward from the outer periphery of the rotating body or the powder passage, if a partition is provided below the opening of the powder collecting pipe to close the cylinder, the partition can collect the powder. Become part of the road. The powder recovery path is preferably inclined toward a certain direction so that the powder naturally falls or slides down and is collected collectively at a certain place. The lower end of the powder recovery path is extended to the outside of the cylindrical body via a recovery pipe or the like, and is recovered from above the powder recovery container.

The powder dividing and sampling apparatus according to the present invention is:
As described above, in addition to removing a small amount of powder for particle size distribution measurement from a large amount of powder, and other divided sampling of measurement samples for measuring various properties of powder other than particle size distribution,
The present invention can also be used for various applications that require a uniform proportion of powder from a large amount of powder.

[0022]

When the powder is continuously dropped above the rotator while the rotator is rotated, while the powder passage portion of the rotator is passing through the powder falling path, The powder enters the powder collection tube that opens below the rotating body. However, as long as the portion of the rotating body other than the powder passage portion is passing through the powder falling path, the falling of the powder is blocked by the rotating body,
No powder enters the powder collection tube. The powder blocked by the rotating body is placed on the rotating body, but is blown to the outer peripheral side by centrifugal force due to the rotation of the rotating body, and falls down from the outer edge of the rotating body, or the powder passage portion is When it is at a position other than above the body sampling tube, it falls down from the powder passage section. The powder dropped from the rotating body is recovered through a powder recovery path.

In this way, of the powder continuously supplied and dropped, only the powder that falls while the powder passage portion of the rotating body passes right above the powder collection pipe is crushed and collected. After entering the tube, the other powder will be collected in the powder collection path. Therefore, in one rotation of the rotating body, only the amount of powder divided according to the ratio of the time when the powder passage portion passes directly above the powder collection tube to the other time is the powder collection tube. Will be taken out. If the rotation of the rotating body is repeated, the amount of powder divided at a fixed ratio is taken out to the powder collecting tube at each rotation, so that the powder is supplied until the required amount of powder is taken out. The rotation of the rotating body may be performed.

That is, with the divided sampling device according to the present invention, the powder can be divided and collected at a ratio corresponding to the ratio of the width or the opening angle of the powder passage portion occupying the circumference of the rotating body. Therefore, even if only a small amount of powder is extracted from a large amount of powder and the division ratio is very large, it is only necessary to change the size of the powder passage portion of the rotating body, and the processing is performed regardless of the division ratio. Time is constant. Therefore, as in the conventional sorting method and the rotary divider, as the division ratio increases, the trouble of increasing the number of repetitions of the division operation or producing a specially divided container is not required.

The powder continuously supplied and dropped is divided at a fixed ratio every rotation of the rotating body, and only a part of the powder is collected. In the same way, the powder is taken out one by one in any part up to the last part, and a sample can be evenly collected from the whole powder. In addition, since only a relatively small rotating body is rotated, the rotating body can be rotated at a much higher speed as compared with the divided container in the conventional rotary divider. As a result, the number of divided samplings can be increased by reducing the amount of the powder to be decomposed and collected in one rotation, and the influence of the local deviation of the properties of the powder can be extremely reduced.

[0026]

Next, an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the overall structure of the device. The powder P is contained in a funnel-shaped hopper 10. The discharge port 12 at the lower end of the hopper 10 is disposed inside the upper end of the cylindrical body 20 at a position from the center of the cylindrical body 20 to the outside. The cylindrical body 20 is installed upright on the upper surface of the base 70. It is preferable that the cylindrical body 20 and other structural portions that may come into contact with the powder P are made of a material such as stainless steel or ceramics that does not easily rust or adversely affect the powder P. Although the upper surface of the cylindrical body 20 is open, a lid that covers the entire upper surface of the cylindrical body 20 except for the discharge port 12 of the hopper 10 can be attached.

Inside the cylindrical body 20, below the outlet 12 of the hopper 10, a substantially disk-shaped rotating body 30 is provided. The rotating body 30 is formed with a powder passing portion 32 in which a part of the outer periphery is cut out in a fan shape. A rotating shaft 42 extending from a motor 40 mounted inside the base 70 is connected to the center of the rotating body 30 so that the rotating body 30 rotates in a horizontal plane.

An upper end of the powder collecting pipe 50 is opened below the rotating body 30 and directly below the discharge port 12 of the hopper 10. The diameter of the powder collection tube 50 is
Are set to the same degree as the diameter of the discharge port 12. The powder collecting tube 50 extends downward, penetrates through the cylindrical body 20, and has a lower end opened above the base 70 outside the cylindrical body 20. A powder collecting container 52 is arranged on the base 70,
The powder falling from the powder collecting tube 50 is received.

Below the upper end of the powder collection tube 50, an inclined partition wall 62 that partitions the inside of the cylindrical body 20 is provided. The inclined partition wall 62 is inclined such that the mounting position side of the powder sampling tube 50 is high and the opposite side is low. The rotating body 30 described above.
Is extended downward through the inclined partition wall 62. A cylindrical cover 68 through which the rotating shaft 42 is inserted is attached to the upper center of the inclined partition 62 to prevent powder from entering the gap between the rotating shaft 42 and the inclined partition 62. It is preferable that the height of the cover 68 be higher than the position where the powder dropped from the rotating body 30 may fly. Near the lowest point of the inclined partition wall 62, the upper end of the recovery pipe 64 is connected and opened.
The collection pipe 64 extends below the inclined partition 62 to the outside of the cylindrical body 20, and a lower end of the collection pipe 64 opens above a collection container 66 installed on the base 70.

FIGS. 2 and 3 show a detailed structure of the rotating body 30. FIG. The rotating body 30 is composed of two substantially semicircular semi-circles 34 and 36, and a mounting screw 44 is inserted into the center in a state where both semi-circles 34 and 36 are partially overlapped. Is screwed and fixed to the upper end of the rotating shaft 42. The semicircular plate 36 which is overlaid on the head of the mounting screw 44
, And between the lower semi-circular plate 34 and the upper end surface of the rotary shaft 42. Mounting screw 4
If the semi-circles 34 and 36 are separately rotated while the 4 is slightly loosened, a notch-shaped gap, ie, a powder passage portion 32, that forms a sector between the semi-circles 34 and 36 is formed. . By changing the rotation position of the semi-circles 34, 36, the opening angle θ of the powder passage section 32 can be freely adjusted in the range of 0 ° to 180 °. After setting the opening angle θ to a suitable value, if the mounting screws 44 are tightened, the semicircles 34 and 36 are fixed to the rotating shaft 42.

The operation of the divided sampling device having the above structure will be described. The powder P is continuously dropped from the discharge port 12 of the hopper 10, and the rotating body 30 is rotated at a constant rotation speed. The powder P that has fallen onto the rotating body 30 passes through the powder passage 32 and enters the lower powder sampling tube 50 while the powder passage 32 is passing through. The powder P that has entered the powder collection tube 50 is stored in a collection container 52 from the lower end of the powder collection tube 50. Powder P ₁ accumulated in the collection container 52 is like measuring sample of interest. When a portion of the rotating body 30 other than the powder passage section 32 is in the path of falling of the powder P, the powder P accumulates on the rotating body 30. Since the rotating body 30 is rotating, a centrifugal force is applied to the powder P, and the powder P is blown to the outer periphery of the rotating body 30 and falls downward. In addition, the powder P that has slid in the circumferential direction on the rotating body 30 may fall from the powder passing unit 50 after the powder passing unit 50 has passed directly above the powder collection tube 50. .
In this way, the powder P that has fallen to a position other than the pulverizing and collecting tube 50 falls or slides downward in the space surrounded by the inner wall of the cylindrical body 20 and the inclined partition 62, and is recovered into the inclined partition 62. Falling into tube 64. The powder P ₀ that has fallen into the collection pipe 64 is collected in the collection container 66.

The above operation is repeated each time the rotating body 30 makes one rotation, and a predetermined amount of powder P
Is dropped and supplied, a certain percentage of the powder P ₁
Accumulates in the collection container 52, and the remaining powder P ₀ is collected in the collection container 6.
6, and the divided sampling of the powder is completed. In the above operation, the proportion of the powder P ₁ which is divided taken to the powder of the total amount is determined by the notch angle of the powder passage portion 32 in the rotating body 30 theta. That is, the rotating body 30
The powder P enters the powder collecting tube 50 only during the angle θ during which the powder P rotates 360 °, so that the division ratio of the powder P ₁ is θ / 3
60 °. For example, if it is desired to divide by six, it is sufficient to set θ = 60 °.

Next, the powder divided sampling apparatus according to the present invention was divided and collected by a conventional method, and the performance was compared. As an embodiment of the present invention, a divided sampling device having a structure shown in FIGS.
At 0 rpm, the opening angle of the powder passage section 32 was set to θ = 60 °. As Comparative Example 1, the above-described sorting method was used.
As Comparative Example 2, a rotation divider divided into six sections was used, and the rotation speed was set to 36 rpm.

The time required for obtaining 10 g of a sample for measurement from 600 g of the powder, that is, the time required for collecting the powder by dividing it by 1/60 was measured.

[0035]

[Table 1]

From the results of the above test, it can be seen that in the embodiment of the present invention, the processing can be performed in a much shorter time than in the conventional method. Next, the accuracy of the divided sampling was measured. Three kinds of powders A to C having different particle size distributions are prepared, the same powder is decomposed and sampled three times, and the particle size distribution of the powder sample divided and sampled each time is measured. The standard deviation of the particle size ratio was calculated.

[0037]

[Table 2]

From the results of the above test, it can be seen that in Examples of the present invention, the variation in the measured particle size distribution is very small as compared with the conventional method. This means that in the apparatus of the present invention, the powder to be used as a sample can always be divided and collected from the entire powder. Next,
The amount of dust generated during the work can be reduced by 5
It was rated on a scale. The higher the evaluation point, the more dust is generated.

[0039]

[Table 3]

From the results of the above test, it can be seen that in the embodiment of the present invention, the generation of dust is smaller than that of the conventional method, and there is no fear of polluting the environment or adversely affecting workers. .

[0041]

According to the apparatus for dividing and collecting powder according to the present invention described above, a very simple operation of rotating a rotating body having a powder passage portion can be used to remove a large amount of powder. Only a small amount of powder can be uniformly collected from the entire powder, and can be accurately and quickly divided and collected.

Moreover, no skill or technique is required for the work,
The outer shape and installation area of the device can be small, and there is little fear that dust will be generated during work. In particular, unlike a conventional rotary divider, there is no need to rotate a large divided container, and only a small rotating body needs to be rotated, so that the structure of the entire apparatus is simplified and mechanical strength is not so required. The manufacturing cost of the device can be reduced.

[Brief description of the drawings]

FIG. 1 is a structural view of an entire apparatus showing an embodiment of the present invention.

FIG. 2 is a plan view of a rotating body.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Hopper 20 Cylindrical body 30 Rotating body 32 Powder passage part 40 Motor 50 Powder collection pipe 62 Inclined partition (powder recovery path) 64 Recovery pipe (powder recovery path)

Claims (4)

(57) [Claims] 1. A cylinder provided with an axis centered vertically, and means for continuously supplying and dropping powder to a position outside a center portion including the axis inside the cylinder, Inside the cylindrical body, a rotating body that rotates around the axis of the cylindrical body and has a powder passage portion at a portion that traverses the powder falling path, and one end provided below the rotating body and having one end of the powder. A powder collecting pipe that opens directly below the falling path and has the other end open to the outside of the cylindrical body; and a powder collecting path that collects the powder shaken off from the upper surface of the rotating body by the action of centrifugal force. A powder dividing and collecting apparatus characterized by the above-mentioned. 2. A powder passage section keeps a rotating body constant in a circumferential direction.
2. The powder according to claim 1, wherein said powder has a sector shape cut out by an angle.
Split sampling device. 3. The rotating body is formed by stacking plate bodies.
3. The powder dividing and sampling apparatus according to claim 1 or 2. 4. A powder divided collection device according to any of claims 1 to 3 in which the rotating body is composed of a superposition of the semicircular plate members.