JP2526862Y2 - Light diffraction, scattering type particle size distribution analyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a light diffraction and scattering type particle size distribution measuring device.

[Conventional technology]

FIG. 4 shows the main parts of a conventional light diffraction and scattering type particle size distribution measuring apparatus, in which 1 is a laser beam emitted from a laser device (not shown) and 2 'is a circulating pump (not shown). The sample liquid is continuously supplied from an ultrasonic dispersing bath (not shown), and a rectangular cylindrical sample cell having an outer space and an internal space 2a 'having a rectangular cross section and a sample cell 2' A lens 4 for condensing the transmitted light and light scattered (diffracted) by the fine particles in the sample liquid in the sample cell is a detector 4 for detecting light from the condensing lens 3, for example, a silicon photodiode.

Thus, in the above particle size distribution measuring device, when the sample cell 2 'is irradiated with the laser beam 1 while the sample liquid is continuously supplied to the internal space 2a' of the sample cell 2 ',
A part of the laser light 1 irradiates the microparticles in the sample liquid in the sample cell 2 ′ to become scattered (diffraction) light 5, which reaches the detector 4 via the condenser lens 3.

[Problems to be solved by the invention]

However, in the particle size distribution measuring apparatus having the above configuration, as shown in FIGS. 5A and 5B, the angle φ ₁ formed between the scattered light 5 scattered by the fine particles 6 and the outer surface 2b ′ of the sample cell. When it is large, that is, when the scattering angle θ ₁ from the microparticles 6 is small (for example, when the dispersion is water, θ ₁ <about
(50 °), the scattered light 5 passes through the sample cell 2 ′
When the angle φ ₂ between the scattered light 5 ′ and the outer surface 2 b ′ of the sample cell is small, that is, when the scattering angle θ ₂ from the microparticles 6 is large (similarly, when the dispersion liquid is water, θ ₁ ≧ (About 50 °), the scattered light 5 ′ is totally reflected by the outer surface 2 b ′ of the sample cell, does not pass through the outer surface 2 b ′ of the sample cell, and the detector 4 cannot receive the scattered light 5 ′. In general, as the particle diameter decreases, the scattering angle θ increases, so it is difficult to measure the particle size of particles having a small particle size using a conventional light diffraction and scattering type particle size distribution analyzer. It was impossible.

The present invention has been made in consideration of the above-mentioned matters, and the purpose is to measure the particle size of particles having a small particle size with high accuracy by relatively simple improvement, and to measure the particle size distribution over a wide range. It is an object of the present invention to provide a light diffraction and scattering type particle size distribution measuring apparatus which enables the measurement.

[Means for solving the problem]

In order to achieve the above object, a light diffraction / scattering type particle size distribution measuring apparatus according to the invention described in claim (1) of the present application provides a sample cell having an outer space and an inner space having a rectangular cross section. A liquid containing fine particles flowing in the internal space is irradiated with coherent light, and the particle distribution is measured by monitoring the intensity pattern of the diffraction and the scattered light diffracted and scattered by the fine particles with a photodetector. In a light diffraction and scattering type particle size distribution measuring device, a mirror surface for reflecting scattered light due to particles having a small particle diameter is formed on a part of the outer surface on the light emission side of the sample cell, and the light detector has a particle diameter. A first photodetector that monitors the intensity pattern of the scattered light by the large particles, and a small particle having a small particle diameter reflected by the mirror surface and taken out from a surface other than the outer surface on the light emission side. By detecting the scattered light has a second feature in that constituted by an optical detector for monitoring the intensity pattern of the light scattered by small particles with a particle size that.

Further, the invention described in claim (2) of the present application is characterized in that a part of the outer surface on the light emission side of the sample cell is chamfered and a mirror surface is formed there.

[Action]

According to the above-described characteristic configuration, a mirror surface that reflects scattered light due to particles having a small particle diameter is formed on a part of the outer surface on the light emission side of the sample cell, so that scattered light due to particles having a small particle diameter can be formed at an arbitrary angle. Scattered light that could not be transmitted through the sample cell because the angle between the scattered light and the outer surface of the sample cell was small in the past can be extracted from the surface other than the outer surface on the light exit side of the sample cell, and the particle diameter can be reduced. It is possible to measure the particle size distribution of particles having a small particle size to particles having a large particle size over a wide range.

Further, it is possible to take out scattered light due to particles having a small particle diameter from a surface other than the outer surface on the light emission side, and to use a photodetector to monitor the intensity pattern of the scattered light due to the particles having a large particle diameter. A photodetector detects light scattered by particles having a small particle diameter reflected by the mirror surface and taken out from a surface other than the outer surface on the light emission side, and monitors an intensity pattern of the light scattered by the particles having a small particle diameter. Since the second photodetector is configured, the second photodetector can be provided with a degree of freedom in installing the second photodetector in opposition to a surface other than the outer surface on the light emission side. It is advantageous.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 (A), 1 (B) and 2 show an embodiment of the present invention. In FIG. 1 (A), reference numeral 7 denotes a laser device for generating a laser beam 1, and 8 denotes a laser beam as appropriate. The expanding beam expander 2 is connected to an ultrasonic dispersion bus (not shown) via a pipe 9 and a sample cell to which a sample liquid is continuously supplied by a circulating pump (not shown). The detector is a detector that detects light transmitted through the cell 2 and includes, for example, a silicon photodiode.

Then, a part of the outer surface 2b on the light emission side of the sample cell 2 is chamfered, and a mirror surface 10 for reflecting the scattered light 5 'due to the particles having a small particle diameter is formed thereon. A first photodetector 4 for monitoring the intensity pattern of the scattered light 5 due to the large particles, and a mirror surface 10 which reflects off a part of the outer surface 2b on the light emitting side and reflects light from a surface other than the outer surface 2b on the light emitting side. The scattered light 5 'due to the extracted small particles is detected, and the scattered light 5' due to the small particles is detected.
And a second photodetector 4 'for monitoring the intensity pattern.

In other words, the major difference between this embodiment and the conventional example is that
As shown in FIG. 1 (B) and FIG. 2, there is a difference between the sample cells, and as shown in FIG. 1 (B) and FIG. The point is that the mirror surface 10 is formed.

Here, the structure and operation of the sample cell 2 will be described with reference to FIG. 2 as well. The sample cell 2 is formed of a material such as glass having excellent light transmittance (for example, quartz, BK-7 glass, etc.). The outer shape of the light transmitting portion and the internal space 2a are formed in a square cross section. And the mirror surface 10
It is preferable that a part of the outer surface 2b of the sample cell is chamfered, and a material such as aluminum or silver is directly vapor-deposited thereon.

As described above, the mirror surface 10 is formed on a part of the outer surface 2b of the sample cell, and the scattered light 5 'due to the particles having a large scattering angle and the small particle diameter is reflected by the mirror surface 10, for example, as shown in FIG. As shown in FIG.
Is taken out of the sample cell 2 and detected by the second detector 4 '. Particles having a small scattering angle and a large particle diameter transmitted from the sample cell outer surface 2b where the mirror surface 10 is not provided are provided. The scattered light 5 is detected by providing the first detector 4 separately.

Further, the chamfer angle formed on a part of the sample cell outer surface 2b is set as shown in FIG. 3 (A), and the second detector 4 'is opposed to the light incident side outer surface 2d of the sample cell 2. By forming a mirror surface 10 after chamfering a part of the sample cell outer surface 2b at an arbitrary angle in this manner,
Scattered light 5 'due to particles having a small particle diameter can be extracted from a surface other than the sample cell outer surface 2b.

In the above embodiment, a part of the outer surface 2b of the sample cell was chamfered and the mirror surface 10 was formed thereon. However, as shown in FIG. 3 (B), the mirror surface 11 was formed without chamfering.
The scattered light 5 'due to particles having a small particle diameter may be detected by the second detector 4' provided opposite to the sample cell side surface 2c.

The size of the mirror surfaces 10 and 11 and the setting of the angle of the chamfer described in each of the above embodiments differ depending on the material and size of the sample cell, the refractive index of the dispersion liquid, and the like. May be selected as appropriate.

Further, the chamfered portion is not limited to a flat surface as in the above embodiment, but may be a curved surface.

[Effect of the invention]

As described above, according to the invention described in claim (1) of the present application, a simple device such as forming a mirror surface on a part of the outer surface on the light emitting side in the rectangular outer shape of the sample cell is provided. Thereby, scattered light due to particles having a small particle diameter, which was conventionally totally reflected on the outer surface on the light emission side, can be taken out of the sample cell from a surface other than the outer surface on the light emission side, and moreover, outside the sample cell. At the transmission position, a first photodetector that monitors the intensity pattern of the scattered light due to the particles having a large particle diameter is provided, and at the reflection position by the mirror surface outside the sample cell, the scattered light due to the particles having a small particle diameter is provided. Since the second photodetector that monitors the intensity pattern of the particles is installed, it is possible to measure not only the scattered light due to the particles having a large particle diameter but also the scattered light due to the particles having a small particle diameter. It can be measured particle size distribution of large particles having a particle size over a wide range from the particles.

In general, on the outer surface on the light emission side, the boundary between the transmission region through which scattered light due to particles having a small particle diameter passes and the total reflection region where total reflection is performed is determined by the shape of the outer surface on the light emission side, the density of a sample, and the like. However, according to the invention described in claim (1) of the present application, irrespective of the fluctuation of the boundary, the scattered light due to the particles having a small particle diameter moves out of the sample cell from a surface other than the outer surface on the light emission side. A mirror surface is formed on a part of the outer surface on the light emission side so as to be taken out.

Therefore, according to the invention described in claim (1) of the present application, the measurement range of the particle size distribution can be expanded, and scattered light due to particles having a small particle diameter can be extracted from a surface other than the outer surface on the light emission side. In addition, the second photodetector can be provided with a degree of freedom when it is installed at a reflection position outside the sample cell, which is advantageous in terms of making the apparatus compact. That is, the installation position of the second photodetector can be freely changed when the apparatus is downsized. For example, as shown in FIG. 3B, the reflection position outside the sample cell can be set on the side of the sample cell.

Also, in the invention described in claim (2) of the present application, the installation position of the second photodetector can be freely changed.
The chamfer angle formed on a part of the light emitting side outer surface of the sample cell is set, for example, as shown in FIG. 3 (A), and the second photodetector is opposed to the light incident side outer surface of the sample cell. By setting the chamfer angle as shown in FIG. 2, for example, scattered light due to particles having a small particle diameter can be taken out of the sample cell from the side surface of the sample cell.

[Brief description of the drawings]

1 (A), 1 (B) and 2 show an embodiment of the present invention, and FIG. 1 (A) is a block diagram showing a main part of a light diffraction / scattering type particle size distribution measuring apparatus. FIG. 2 (B) is an overall perspective view showing the sample cell, and FIG. 2 is a view for explaining its operation. 3 (A) and 3 (B) show another embodiment of the present invention, and are diagrams for explaining the operation of the sample cell. FIG. 4 and FIG. 5 are diagrams for explaining the prior art. 2 ... sample cell, 2b ... outer surface of sample cell on light emission side, 4
... A first detector for monitoring the intensity pattern of the scattered light due to the particles having a large particle diameter; 4 ′ a second detector for monitoring the intensity pattern of the scattered light due to the particles having a small particle diameter; Light scattered by large diameter particles, 5 '...
… Light scattered by particles with a small particle diameter, 6 …… fine particles,
10,11 ... Mirror surface.

Claims (2)

(57) [Scope of request for utility model registration] 1. A liquid containing fine particles flowing through an internal space of a sample cell having an outer space and an internal space having a rectangular cross section is irradiated with coherent light, and diffracted and scattered by the fine particles. Diffraction, light diffraction to measure the particle distribution by monitoring the intensity pattern of the scattered light with a photodetector, in the scattering particle size distribution measurement device,
A mirror surface for reflecting scattered light due to particles having a small particle diameter is formed on a part of the outer surface on the light emission side of the sample cell, and the photodetector monitors an intensity pattern of scattered light due to the particles having a large particle diameter. A first photodetector that detects scattered light due to particles having a small particle diameter reflected by the mirror surface and extracted from a surface other than the outer surface on the light emission side, and detects the scattered light due to the particles having a small particle diameter. A light diffraction and scattering type particle size distribution measuring device comprising a second photodetector for monitoring a pattern. 2. A light diffraction and scattering type particle size distribution measuring apparatus according to claim 1, wherein a part of the outer surface on the light emitting side of the sample cell is chamfered and a mirror surface is formed there.