JP3530453B2 - Sampler for particle size distribution sample - 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 sampling, for example, a sample used for dry particle size distribution measurement, for example, a minute amount of a powder sample which is easily dissolved in a solvent.

[0002]

2. Description of the Related Art When a very small amount (for example, several mg) of a powder sample which is easily dissolved in a solvent is used to measure the particle size distribution, a dry type particle size distribution measuring apparatus as shown in FIG. 5 is generally used. In this figure, 51 is a laser light source for generating a laser beam L, and 52 is a beam expander. S is a sample body in which a powder sample (not shown) is attached to one surface of the optical plate 53, and the optical axis 5 is moved by the holder 54 with the powder sample side facing the laser beam incident side.
It is held in a posture perpendicular to 5. Further, 56 is a magnifying lens, and 57 is a photodetector.

By the way, when the particle size distribution of a very small amount of powder sample is measured by using the dry particle size distribution measuring apparatus having the above-mentioned structure,
The most important thing is to uniformly disperse the powder sample on one surface of the optical plate 53 without classifying it.

FIG. 6 shows a conventional sampling device for powder samples. The one shown in FIG. 6A is a powder spray type and has a cylindrical shape below a spray cylinder 62 having an orifice 61 at the center of the lower end. A collector 63 is extended, an optical plate 53 is horizontally provided below the collector 63, and a cylindrical partition wall 64 is erected on the upper surface of the optical plate 53 so as to surround the collector 63, and a powder sample 65 is accommodated therein. The other end of a U-shaped sample introduction tube 67, one end of which is inserted into the sample container 66, faces the orifice 61, and the high pressure air A is introduced from the introduction port 68 on the upper side of the spray cylinder 62, whereby the orifice is formed. The powder sample 65 is jetted from 61, and the powder sample 65 is attached in a dispersed state to the portion surrounded by the partition wall 64 of the optical plate 53. 69
Is the diffuser.

In the structure shown in FIG. 6B, a powder sample 65 is placed on a sample holder 71 having a concave shape, and an optical plate 53 is erected on the concave side of the sample holder 71. Then, the pulse-like high-speed air stream 72 is blown onto the powder sample 65 from above the sample holder 71 to attach the powder sample 65 to the surface of the optical plate 53 in a dispersed state.

[0006]

However, in the method shown in FIG. 6A, since the diffuser 69 is provided below the orifice 61, the optical plate 5 is not provided.
Although the surface of 3 is not likely to be damaged, there are the following problems. That is, the diameter of the powder sample 65 is 50
Particles of μm or more fall on the optical plate 53 and are sampled, but small particles of 1 μm or less in diameter are scattered to the outside of the partition wall 64 along with the air flow as shown by the arrow in the figure, and the powder sample 65 Optical plate 53 in a state in which the
Difficult to sample on.

Further, in the method shown in FIG. 1B, since the powder sample 65 is blown by the pulse airflow 72, there is a disadvantage that the surface of the optical plate 53 is easily scratched, and the powder sample 65 Among them, particles having a size of 1 μm or less are dissipated together with the air flow, and if the pulse of the pulsed high-speed air flow 72 is long, there is a problem that even large particles having a size of 100 μm or more are blown off.

The present invention has been made in view of the above matters, and an object thereof is to attach a powder sample to one surface of an optical plate in a uniformly dispersed state without classifying the powder sample. A sample sampling device for measuring particle size distribution (hereinafter, simply referred to as a sampling device) is provided.

[0009]

In order to achieve the above object, the sampling device of the present invention has a vacuum inside.
Airtight container and airtightly insert it from outside to inside.
Install the sample introduction tube and the sample introduction tube at the upper end.
Closed sample hopper and this sample hopper
A lid configured to form an air reservoir by
Nozzle provided at the lower end of the sample introduction tube and the way of the sample introduction tube
The cock provided inside and below the nozzle
The diffuser and the nozzle below the interior of the container.
A vacuum is drawn inside the container and the optical plate installed horizontally below.
Composed of a vacuum pump that produces a predetermined pressure reduction condition.
It is characterized (Claim 1).

In the above sampling apparatus, when the powder sample is once held in the sample hopper which is connected to the upper end of the sample introduction pipe inserted and connected to the upper part of the container and the inside of the container is in a predetermined reduced pressure state, By opening the cock and connecting the inside of the container with the sample hopper, the powder sample is sucked into the container, and the powder sample is sprayed onto the optical plate provided below the sample introduction tube. Therefore, the particle size is 1μ
Number 1 from micrometer such as m or submicron
It is possible to obtain a sample body suitable for use in dry particle size distribution measurement, which can be attached to an optical plate in a state of being dispersed even in a considerably large particle such as 00 μm in a very short time, and which is very easy to obtain. it can.

[0011] Then, specimen hopper is closed by a lid, so are as air reservoir is formed, when opening the cock, a certain amount of homogeneous powder sample on an optical plate by the air in the air reservoir Dispersed in. And since air is not newly supplied from the sample hopper side,
The powder sample once dispersed and attached to the surface of the optical plate is not disturbed again by the air flow.

Further, as described in claim 2 , when the sample introducing pipe is bent in a crank shape outside the container, the powder sample can be temporarily held in the sample introducing pipe.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. 1 to 3 show a first embodiment of the present invention.
FIG. FIG. 1 schematically shows the structure of a sampling device of the present invention. In this figure, reference numeral 1 denotes a cylindrical container, which is composed of, for example, a container upper member 2 and a container lower member 3 which can be combined and separated. A flange 4 is formed at the lower end of the opening of the container upper member 2 and the container lower member 3 is formed.
A flange 5 having the same diameter as that of the flange 4 is formed at the upper end of the opening, and by overlapping the flanges 4 and 5,
It is formed so that the inside can be sealed. This container 1
Has a mechanical strength such that it is not damaged or distorted even when the inside is evacuated to a decompressed state, and is formed of, for example, glass or an appropriate plastic, and the internal volume is, for example, 3 to 5
It is about L.

A sample introducing pipe 7 for introducing the powder sample 6 into the container 1 is airtightly inserted from the outside to the inside of the container upper member 2 in the upper part of the container 1.

A sample hopper 8 for temporarily holding the powder sample 6 is provided at the upper end of the sample introduction tube 7. The sample hopper 8 has an inverted conical shape, and a flange 9 is provided around the outer edge of the upper end portion. In addition, inside the sample hopper 8, an appropriate mesh (0.4 to 0.8 mm)
The filter 10 is provided. Further, 11 is a lid that is detachably attached to the sample hopper 8 and closes the opening in a hermetically closed state. A flange 12 having the same diameter as the flange 9 is provided around the outer edge of the lower end of the sample hopper. 8
And an air reservoir 13 is formed therein.

A nozzle 14 is provided at the lower end of the sample introducing pipe 7.
Further, a divergent collector 15 is provided so as to be continuous with the nozzle 14. And 1
Reference numeral 6 denotes a diffuser provided slightly below the nozzle 14, and although not shown in detail, it is held by the collector 15 by using an appropriate holding member. The diameter of the nozzle 14 is, for example, about 0.7 to 1 mm.

The sample introduction tube 7, the sample hopper 8, the lid 11, the collector 15 and the diffuser 16 are made of glass or plastic having appropriate strength. Also,
The inner diameter of the sample introduction tube 7 is, for example, about 2 to 3 mm.

Then, in the middle of the sample introducing pipe 7, more specifically, outside of the container 1, a cock 17 (hereinafter referred to as a first cock) for shutting off or communicating the inside of the container 1 and the sample hopper 8 side.
(Cook) is provided.

Below the inside of the container 1, more specifically, inside the container lower member 3, an optical device for collecting the powder sample 6 that is sucked and dropped into the container 1 through the sample introduction tube 7. Board 1
An optical plate holder 19 for holding 8 in a horizontal state is provided. The optical plate 18 is made of a material that does not absorb or block irradiation light such as laser light used in particle size distribution measurement, and is made of glass, for example.

Reference numeral 20 denotes an exhaust flow path for evacuating the interior of the container 1, one end of which is connected to, for example, the side surface of the container lower member 3, and the other end thereof is connected to a vacuum pump 21. A pressure gauge 22 and a cock 23 (hereinafter referred to as a second cock) are provided in the exhaust passage 20.

Next, an example of a method of forming a sample body used for dry particle size distribution measurement by using the sampling device having the above-mentioned structure will be described with reference to the timing chart shown in FIG. Now, it is assumed that the cocks 17 and 23 are closed and the vacuum pump 21 is stopped. In this state, the connection between the container upper member 2 and the container lower member 3 is released, and the optical plate 18 is set on the optical plate holder 19 in the container lower member 3,
The container upper member 2 and the container lower member 3 are joined together to make the container 1 in a hermetically sealed state. After this setting, the lid 11 is opened and a small amount (for example, about several mg) of the powder sample 6 is put into the sample hopper 8.

After the sample is charged, the lid 11 is attached to the sample hopper 8.
Vaseline is evenly applied to the joint surfaces of the flanges 9 and 12 before the covering. In this way, if vaseline is applied to the mating surfaces of the sample hopper 8 and the lid 11, the sample hopper 8
Airtight air reservoir 1 that is isolated from the outside air by the lid 11
3 can be formed. The charged powder sample 6 is filtered through the filter 10 in the sample hopper 8.

Then, the second cock 23 provided in the exhaust passage 20 is opened, the vacuum pump 21 is turned on, and suction of the air in the container 1 is started. When the inside of the container 1 is gradually decompressed and becomes a vacuum state of, for example, about −100 kPa, the second cock 23 is closed and the vacuum pump 21 is closed.
Turn off. After that, when the first cock 17 is opened and the inside of the container 1 is communicated with the sample hopper 8 side, the powder sample 6 on the atmospheric pressure side is strongly sucked into the container 1 side and descends in the sample introduction pipe 7. . At this time, when the air in the air reservoir 13 formed in the sample hopper 8 and the lid 11 enters the container 1, it is narrowed down by the nozzle 14 to become a high-speed air flow,
The aspirated powder sample 6 is transferred to the container 1 by this high-speed air flow.
It gushes into the interior and is diffused.

In this case, the powder sample 6 vigorously ejected from the nozzle 14 collides with the diffuser 16 and the agglomerates are finely crushed. Further, the diffuser 16 alleviates the powder sample 6 vigorously ejected from the nozzle 14 from directly colliding with the surface of the optical plate 18, so that the surface of the optical plate 18 may be damaged by the powder sample 6. To be prevented. Further, since the collector 15 is provided around the nozzle 14 and the diffuser 16, the powder sample 6 is prevented from spreading unnecessarily, and the powder sample 6 is located below the optical plate 18.
Drops and adheres on top in a uniformly dispersed state.

Since the powder sample 6 is sucked into the container 1 vigorously, the time period for which the first cock 17 is in the open state may be short, and the first cock 17 is immediately closed after being opened.

As described above, the powder sample 6 can be attached to the upper surface of the optical plate 18 in a uniformly dispersed state.

In the sampling device, the sample hopper 8 is closed by the lid 11 so that the air reservoir 13 is formed.
When 7 is opened, the powder sample 6 is uniformly dispersed on the optical plate 18 by a certain amount of air in the air reservoir 13. Since no new air is supplied from the sample hopper 8 side, the powder sample 6 once dispersed and attached to the surface of the optical plate 18 is not disturbed again by the air flow.

Further, since the sample hopper 8 is provided with the filter 10 having an appropriate mesh, the sample introduction pipe 7 is not clogged by the large-diameter particles in the powder sample 6.

A desired particle size distribution can be measured by setting the optical plate 18 to which the powder sample 6 is attached as described above as a sample body at the position of symbol S shown in FIG.

FIG. 3 shows the results (curve A in the figure) of a sample body formed by using the sampling apparatus of the present invention, measured by a dry type particle size distribution measuring apparatus, and the results obtained by the wet measurement (FIG. 3). The curve B) in the figure shows that there is almost no difference in the measurement results between the two.

In the above-mentioned embodiment, the sample introducing pipe 7 is linear, but as in the sampling device of the second embodiment shown in FIG.
May be bent in a crank shape outside the container 1. In such a structure, before the powder sample 6 is sucked, the powder sample 6 is attached to the bent portion 7a or 7b.
Can be temporarily stored.

In any of the above-mentioned embodiments, the lid 11 is not always necessary. When the lid 11 is not provided, the container 1 is brought into a predetermined vacuum state and then the first cock 17 is opened to open the sample. The powder sample 6 on the hopper 8 side is placed in the container 1
It is necessary to close the first cock 17 immediately after suctioning the first cock 17.

Further, a thin film may be provided at the connecting portion 8a between the sample hopper 8 and the sample introducing tube 7 to temporarily stop the powder sample 6 that has passed through the filter 10. The thickness (strength) of this film is set to such a degree that the container 1 is broken by the air flow when the first cock 17 is opened and vacuum suction is performed after the container 1 is brought into a predetermined vacuum state.

Although the container 1 is divided into two parts up and down in the above-mentioned embodiment, it is not limited to this. For example, the container 1 is integrally made of plastic having appropriate strength. Formed on the optical plate 18
There may be provided an opening for taking in and out and a door for airtightly opening and closing the opening.

The internal volume of the container 1 and the sample introduction tube 7
Needless to say, the inner diameter can be appropriately set depending on the size of the optical plate 18 and the amount of the powder sample 6 dispersed.

[0036]

As described above, according to the sampling device of the present invention, the powder sample can be attached to one surface of the optical plate in a uniformly dispersed state without being classified. . In particular, when the powder sample is easily dissolved in a solvent or is present in a very small amount, it can be adhered to the optical plate in a uniformly dispersed state, which can greatly contribute to the dry particle size distribution measurement.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing an example of the configuration of a sampling device of the present invention.

FIG. 2 is a timing chart for explaining the operation of the sampling device.

FIG. 3 is a diagram showing an example of a result of measuring a particle size distribution of a sample body formed by the sampling device.

FIG. 4 is a diagram schematically showing another example of the configuration of the sampling device of the present invention.

FIG. 5 is a diagram schematically showing a general configuration of a dry particle size distribution measuring device.

FIG. 6 is a diagram for explaining a conventional sampling device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Container, 6 ... Powder sample, 7 ... Sample introduction tube, 8 ... Sample hopper, 11 ... Lid, 13 ... Air reservoir, 14 ... Nozzle, 1
6 ... Diffuser, 17 ... Cock, 18 ... Optical plate.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Makoto Oishi 2 Higashi-cho, Kichijoin-miya, Minami-ku, Kyoto-shi, Kyoto Prefecture Horiba Manufacturing Co., Ltd. (72) Riki Tateiwa 2 Higashi-cho, Kichijoin-miya, Minami-ku, Kyoto, Kyoto HORIBA, Ltd. (56) Reference JP-A-11-337469 (JP, A) Actually developed 63-181854 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01N 15 / 00-15/14 G01N 1/00-1/34

Claims (2)

(57) [Claims] 1. A container which can be evacuated and is hermetically sealed.
Sample introduction tube inserted from outside to inside
And a sample hopper provided at the upper end of the sample introduction tube
And by closing this sample hopper,
A lid configured to be formed and a lower end of the sample introduction tube
The nozzle provided and the nozzle installed in the middle of the sample introduction tube
And a diffuser provided below the nozzle
And horizontally installed below the nozzle below the inside of the container.
Evacuated the optical plate and the inside of the container to reduce the pressure to the specified level.
Granularity characterized by consisting of a vacuum pump to bring into a state
Sampling device for samples for distribution measurement. 2. The sample introduction pipe is a crank outside the container.
The particle size distribution measurement according to claim 1, wherein the particle size distribution is bent into a shape.
Sample sampling device.