JPH02285238A - Laser diffraction type particle size distribution measuring apparatus - Google Patents

Abstract

PURPOSE:To enable measurement of a particle size distribution even for powder with a high coagulating force and adhesion strength by building up a passage with which a sample is circulated and passed through a flow cell of a non- adhering material while a passage means for a sample is made up a pressure liquid feeding means. CONSTITUTION:A flowcell 4 through which a sample is passed is irradiated with a laser light and a diffraction light generated is measured to determine a particle size distribution in the sample. Then, a passage with which the sample is circulated and passed through the flowcell 4 is made of a non-adhering material such as teflon tube 34 while a sample passing means is composed of a pressure feeding means, for example, a piston pump 331. This eliminates coagulation and adhering of the sample within the passage and as the sample passing means is composed of a pressure liquid feeding means not of a squeeze pump, there is neither coagulation nor adhesion of the sample in the pump.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a laser diffraction type particle size distribution measuring device for use in measuring the particle size distribution of sample particles that have particularly strong agglomeration and adhesion.

(B) Prior art Overall configuration diagram of a conventional laser diffraction particle size distribution measuring device t-
It is shown in Figure 3.

1 is a sample container that contains the entire suspension, 2 is an ultrasonic bath, and 3
is a circulation pump that circulates the suspension, 3 is a circulation flow path, 4 is a flow 7 μ, 5 is a companion semiconductor laser that irradiates the suspension with Frose/I/4 circle, 6 is a collimator,
7 is a condensing lens for condensing diffracted light, 8 is a detector for forming a diffraction image, 9 is an ultrasonic transducer for transmitting ultrasonic waves to an ultrasonic bus, 10 is an oscillator, 11 is a starter, 12 1 is a slit, 13 is a scattering element for detecting a scattering source, and 14 is a combeater.

In the above configuration, in order to measure the particle size distribution, the suspension s2 is first suspended in the container 1 by ultrasonic imaging. Then, pump 3 pumps the suspension S from container 1 to container 7.
a-Cell 4→Circulate within container 1. When the semiconductor laser 5 Q7C1-- is irradiated with laser light at /L/4 during circulation, the laser light is refracted by particles in the suspension S. When the first fold yti-condensing lens 7 focuses the light, a ring-shaped diffraction image is obtained behind the particle group, and the diameter and intensity distribution of this diffraction source ring are correlated with the particle size distribution, and the particle size distribution is measured. can. Incidentally, the analysis of the diffraction image pattern having the correlation t with the particle size distribution is performed by the combination 14.

Problems to be Solved by the Invention In the above-mentioned conventional apparatus, a squeeze bonder is used for the circulation bonder 3, and a silicone tube or a bitonch blower is not used for the circulation flow path 3.

Therefore, when measuring powders with strong cohesive force or adhesive force, the sample passes through a pump and a cheap tube. I couldn't use it at all and had to resort to the sieve method. In this method, the particle size distribution is measured by stacking 7/I/I with different mesh sizes in several stages and checking which 7/I/I collects particles in the nth position.

However, this method requires time kl! management was not easy.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to solve the above problems and to enable even powders with strong cohesive force to be measured by a laser diffraction particle size distribution analyzer.

In order to solve the above-mentioned problems, the present invention irradiates a flow cell through which a sample is passed with a laser beam and measures the diffracted light generated thereby. - A laser diffraction particle size distribution measuring device for measurement, characterized in that the flow path for circulating the sample through the flowsay is formed of a non-adhesive material, and the sample circulation means is constituted by a pumping liquid means. shall be.

Here, the non-adhesive material is, for example, a Teflon tip, and the pressure feeding means is a piston bond.

(e) Function In the present invention, since the flow channel through which the sample flows is formed of a non-adhesive material, the sample does not coagulate and adhere to the flow channel, and the tx sample flow means is not a squeeze pump, but a pumping liquid. Since the sample is configured by means, - the sample does not aggregate or adhere to the inside of the bonder.

(f) Example Embodiments of the present invention will be described based on the drawings.

FIG. 1 is an overall schematic diagram of the device according to the present invention, and is a conventional device (
Items that are the same as those in Figure 3) are given the same numbers.

That is, l is the sample container containing the suspension, and f over 2 fl
wave bath, 4 is a semiconductor laser for irradiating the suspension in the 70-ce&, 51j flose/l/4 with a laser source, 6
is a collimator, 7 is a clay condenser lens that collects diffracted light, 8 is a detection surface that forms a diffraction image, 9 is an ultrasonic transducer that transmits ultrasonic waves to an ultrasonic bus, 10 is an oscillator, and 11 12 is a slit, 13 is a scattering source receiving element for detecting a side scattering source, and 14 is a combeater.

33.34Fi is a characteristic part of the present invention, and 33 is a sample distribution means, and 34 is a secondary circulation channel formed of a Teflon tube.

It is composed of an I-rich sample distribution means 33, a funnel-shaped pump tank 332, and a piston pump 331, and the piston bonder 331 is connected to the cap 334 via a packing 333t.
32.

The cap 334 is provided with a ninth hole into which the circulation flow path 34 is inserted, in addition to the diameter that connects the piston bond 331'kW.
ing.

Further, a circulation flow path 34 is connected to the lower part of the pump tank 332 via a check valve 335.

In addition, the operation of the piston pump 331 is as follows:
Controlled by

Next, the present invention will be explained in detail.

First, a sample is dispersed within the container 1 by ultrasonic vibration.

Then, when the piston bonder 331 is activated and the pressure in the bonder tank 332 is tMJ, the sample flows in the direction of the arrow. At this time, the sample passes through 701c/94i, so the particle size distribution is measured using the same method as in the conventional device.

Once the measurement is completed, the same measurement can be performed many times by repeating depressurization and pressurization by the piston pump 331.

Note that even if the pressure inside the pump tank 332 is reduced by the piston pump 331, the sample will not flow back because a check valve 335 is provided at the bottom of the cypress.

FIG. 2 shows an example of the effectiveness of the present invention in the above operation.

This fL was obtained by using Teflon powder as a sample, and Figure 2 (a) shows the grain size obtained when experimenting with a conventional device. The distribution curve (in FIG. 2) is the particle size distribution curve when experimented with the apparatus of the present invention. The vertical axis in the figure is the cumulative particle amount (volume%
), the horizontal axis shows the particle diameter (μ).

As is clear from FIG. 2, according to the present invention, when the same sample is measured several times, the same results can be obtained. This means that even if the number of measurements is increased, the sample will not aggregate or adhere to the bonder or flow path.

(g) Effects According to the present invention, it is possible to measure particle size distributions with strong agglomeration and adhesive force.

Particles and ethyl methyl ketone dispersed in strong acid solutions such as concentrated sulfuric acid, concentrated hydrochloric acid, and concentrated nitric acid, and strong alkaline solutions.
silicone, such as toene, tetrahtomifuran, etc.
Baitonchi Tamefu.

It can also be applied to particle size distribution measurements of particles dispersed in organic solvents that dissolve

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2(a). (b) is the particle size distribution curve when the particle size distribution of Teflon powder was measured using the conventional device and the device of the present invention, No. 31! It is a conventional diagram. 33...Sample distribution means 34...Teflon chip (conventional moat carrier) First bacteria Figure 2

Claims (1)

[Claims] 1. Irradiating a flow cell through which a sample flows with a laser beam,
In a laser diffraction particle size distribution measuring device that measures the particle size distribution in a sample by measuring the diffracted light generated from the laser diffraction, a flow path for circulating the sample through the flow cell is formed of a non-adhesive material, and a flow path for the sample is 1. A laser diffraction particle size distribution measuring device, characterized in that the means comprises a pumping liquid means.