JP3185451B2 - Powder feeder for particle size distribution measurement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder supply apparatus used when a dry powder is dispersed in air to measure a particle size distribution by a so-called dry method.

[0002]

2. Description of the Related Art In a laser diffraction / scattering type particle size distribution measuring apparatus, generally, a powder to be measured is dispersed in a medium, and a diffraction / scattering method is obtained by irradiating the dispersed powder with a laser beam. The intensity distribution of the scattered light is measured, and the particle size distribution of the powder is obtained from the measurement result by calculation based on the Fraunhofer diffraction theory or Mie's scattering theory.

When such a laser diffraction / scattering type particle size distribution measuring device is used to measure the particle size distribution of a powder that is dissolved in a liquid, as is often seen in, for example, the pharmaceutical and food fields, a medium is used. Since a liquid cannot be used as a medium, usually, air is used as a medium, the powder to be measured is in an aerosol state, and a laser beam is irradiated to measure the intensity distribution of diffraction / scattered light.

[0004] As a powder supply apparatus in such a dry type particle size distribution measurement, there is a conventional apparatus using a rotating disk which can be rotated around a vertical axis. A conventional powder supply device using this rotating disk puts the powder on a smooth surface on the upper surface of the rotating disk, and rotates the rotating disk to a predetermined position where, for example, a powder suction device is placed. Transfer or supply, or cut a single ring-shaped groove around the rotation axis on the upper surface of the rotating disk, fill the groove with powder, and rotate the powder in the groove similarly. The fixed amount is supplied to a predetermined position by the rotation of the disk.

[0005]

Among the above-mentioned conventional powder supply apparatuses, the one in which the powder is placed on a smooth disk surface and transported and supplied, the scraping plate is brought into contact with the upper surface of the rotating disk. Even if it is arranged to scrape off excess powder, it is difficult to continuously supply a constant amount of powder.

On the other hand, in the case where a ring-shaped groove is cut on the upper surface of a disk, a fixed amount of powder can be easily supplied by combination with a scraping plate. However, since there are various sizes of powder particles, large particles whose diameter is close to the size of the cross section of the groove are not uniformly filled in the groove, and conversely, particles having an extremely small diameter are In such a case, it is difficult to fill the groove, and there is a problem that, with respect to the size of the groove, powder having a diameter outside the predetermined range can be supplied only with a lack of quantitativeness.

The present invention has been made in view of such circumstances, and can be easily adapted to various powders having different particle sizes by an extremely simple operation.
It is an object of the present invention to provide a powder supply device capable of supplying a constant amount of the powder.

[0008]

A structure for achieving the above object will be described with reference to FIG. 1 which is an embodiment drawing. The powder supply device of the present invention rotates around a vertical axis. On the upper surface of a given rotating disk 1, a plurality of grooves 2 having different widths and depths about a rotation axis thereof are provided.
a, 2b, and each groove 2 of the rotating disk 1
a powder feeder (for example, a hopper) 3 for selectively filling the powder into the a and 2b, and a powder suction means (for example, a suction pipe) 4 for sucking the powder in the groove and transferring it to a predetermined position. It is characterized by having.

[0009]

In use, a groove to be filled with the powder by the powder supply device 3 is selected according to the size of the powder particles to be supplied. In other words, if the powder particles are fine, select a groove with a small width and depth to fill the powder, and if the powder particles are large, select a groove with these dimensions that are irregular to transfer the powder. Fill. By selectively sucking and transferring the powder in the groove filled with the powder by the powder suction means 4 in this manner, the quantitativeness of the powder can be ensured.

[0010]

1 is an external perspective view of an embodiment of the present invention, and FIG. 2 is a plan view (A) and a front vertical sectional view (B) of the rotary disk 1 thereof.

The rotating disk 1 is fixed to a vertical shaft 1a passing through the center thereof, and the vertical shaft 1a is rotated about its axis by a driving device 1b mainly composed of a motor in a direction indicated by an arrow in FIG. Is given.

On the upper surface of the rotating disk 1, a plurality of, for example, two ring-shaped grooves 2 are arranged concentrically about the rotation axis thereof.
a and 2b are engraved, and these grooves 2a and 2b are
As shown in FIG. 5, the width and the depth are different from each other, and the width and the depth of the inner groove 2a are all smaller than the width and the depth of the outer groove 2b.

A funnel-shaped hopper 3 is provided adjacent to the rotating disk 1.
The hopper 3 is supported by a stand 5. The stand 5 includes a slider 52 that can move up and down along a vertical axis 51, and a horizontal axis 53 that can slide in a horizontal through hole formed in the slider 52, and one end of the horizontal axis 53. The hopper 3 is attached, and thus the position of the hopper 3 can be adjusted horizontally and vertically with respect to the rotating disk 1.

A stand 5 is provided adjacent to the rotating disk 1.
A stand 6 having a vertical shaft 61, a slider 62 and a horizontal shaft 63 is provided in the same structure as that described above, and the end of the horizontal shaft 63 of the stand 6 communicates with a pressure reducing port of an ejector (not shown). The suction pipe 4 is fixed with the suction port at the tip thereof directed vertically downward. With this configuration, the position of the suction port of the suction tube 4 can be adjusted in the horizontal direction and the vertical direction with respect to the rotating disk 1.

Above each of the grooves 2a and 2b of the rotating disk 1, a scraping plate 7 is disposed so as to straddle both of them and at a height almost in contact with the upper surface of the rotating disk 1.
A collection container 8 is disposed below the outer periphery of the disk 1 at the position where the scraping plate 7 is disposed.

When the above embodiment of the present invention is used, if the powder particles to be supplied are relatively large, the outer groove 2b
If it is smaller, the inner groove 2a is selected. That is, when the particle diameter is large, the hopper 3 and the suction pipe 4
The stands 5 and 6 are adjusted so that the suction port is located directly above the groove 2b, and when the particle diameter is small, they are also positioned directly in the groove 2a.

After selecting either of the grooves 2a or 2b in this way, the rotating disk 1 is rotated,
Suction is started by the suction pipe 4 while the powder inside the hopper 3 is dropped and supplied. As a result, the powder supplied to the groove 2a or 2b passes through the position where the scraping plate 7 is disposed, so that the powder other than the inside of the groove is scraped off and falls into the collection container 8, and falls into the groove. The remaining powder reaches the position of the suction pipe 4 and is sucked and transferred to the particle size distribution measuring device.

According to the above embodiment of the present invention, the rotating disk 1
If the rotation speed is constant, simply adjust the stands 5 and 6 and select a groove suitable for the particle size of the powder, and a fixed amount of powder will be supplied to the particle size distribution measuring device for a fixed time. Will be done.

The number of grooves provided on the upper surface of the rotating disk 1 is not limited to two, but may be any plural number, and the cross-sectional shape of each groove is, for example, as shown in FIG. Various shapes such as rectangles, triangles, and semicircles can be adopted, and each groove is provided with a wall protruding from the surface of the disk 1 as shown in FIG. May be formed.

Furthermore, each groove is not necessarily completely ring-shaped, but may be partially interrupted.

[0021]

As described above, according to the present invention,
A plurality of grooves having different widths and depths are formed on the upper surface of the rotating disk around the rotation axis, and powder can be selectively supplied to each of the grooves by a powder supply device. In addition, since it has a structure in which the powder suction means for sucking the powder in the groove and transferring the powder to a predetermined position is provided, a groove corresponding to the size of the powder particles to be supplied is selected. By doing so, it has become possible to easily adapt to various powders having different particle diameters and to constantly supply these powders.

[Brief description of the drawings]

FIG. 1 is an external perspective view of an embodiment of the present invention.

FIG. 2 is a plan view (A) and a front central longitudinal sectional view (B) of the rotating disk 1;

FIG. 3 is an explanatory diagram of an example of a cross-sectional shape of a groove formed on a rotating disk according to the present invention.

FIG. 4 is an explanatory view of another configuration example of a groove similarly formed on the rotating disk of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotating disk 1a Vertical axis 1b Drive device 2a, 2b Groove 3 Hopper 4 Suction tube 5, 6 Stand 7 Scraping plate

Claims (1)

(57) [Claims] 1. A device for dispersing a powder to be measured in air and quantitatively supplying it to a measuring unit of a laser diffraction / scattering type particle size distribution measuring device, wherein rotation is applied around a vertical axis. And a rotating disk having a plurality of grooves having different widths and depths about the rotation axis formed on the upper surface thereof, and powder is selectively applied to each groove of the rotating disk. A powder supply device for particle size distribution measurement, comprising: a powder supply device to be filled; and a powder suction means for sucking powder in a groove and transferring the powder to a predetermined position.