JPS63139231A - Method for measuring fine particles in liquid - Google Patents

Abstract

PURPOSE:To measure solid fine particles while discriminating the same from air bubbles, by a method wherein intensive beam such as laser beam is converged to a liquid specimen, and the converged beam and a pressure wave due to ultrasonic vibration are simultaneously applied. CONSTITUTION:The laser beam emitted from a laser beam source 1 is converged by a converging lens 2 to be converged in a measuring cell 4 so as to become vertical to the flow of a specimen L having a definite flow speed. An ultrasonic vibrator 3 is arranged so as to be made vertical to the cell 4 and an ultrasonic wave is allowed to impinge against the specimen L so as to become vertical to the flow of said specimen L. When the specimen L passes through the cell 4 at the definite flow speed, the specimen L receives both of the converged laser beam and vibration due to the ultrasonic wave and, when solid fine particles and air bubbles are present, the laser beam passing through the cell 4 generates irregular reflection to be blocked by a beam stopper 6. This irregularly reflected laser beam is condensed to a photomultiplier tube 8 by a condensing lens 7 and divided into two kinds of the wave forms from the particles and the air bubbles to be sent to a signal processing circuit 9. The circuit 9 sorts the solid fine particles and the air bubbles and performs sorting at every particle size.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a method for managing ultra-fine water medicinal liquids by identifying solid particles present in such liquids as air bubbles. This is related to the method of measuring.

[Conventional technology]

Conventional methods for measuring fine particles in liquid include microscopy, light blocking method, light scattering method, and ultrasonic scattering method.

However, with the microscopy method, all of the solid particles placed on the paper are visually observed and measured, so the particles in the liquid cannot be measured instantaneously, making it impossible to determine whether or not the liquid contains air bubbles. There is. Also, with other methods, it was not possible to determine whether the measured object was solid particles or bubbles.

[Problem that the invention seeks to solve]

Therefore, the present invention attempts to measure while accurately distinguishing between fine particles and bubbles when all bubbles are present in the liquid.

[Ninth method to solve all problems]

The present invention aims to solve all of the above-mentioned problems in the conventional technology by converging a strong source sample liquid such as a laser using a light scattering method and simultaneously applying pressure waves by ultrasonic vibration to the convergence area. , a clear difference is created between the electric signal waveforms obtained from solid particles and air bubbles, and solid particles and air bubbles are distinguished and measured.

[For production]

Particles in a liquid completely scatter the irradiated light, and there is a correlation between the intensity of the scattered light and the particle size, so the particle size can be determined from the intensity of the scattered light. The scattered light is converted into an electrical signal using a photomultiplier tube, etc., and then measured. On the other hand, when pressure is applied within the measurement region, the volume of air bubbles contained in a liquid changes more greatly than that of solid particles, depending on the pressure distribution.

Therefore, the intensity of scattered light from the bubbles changes with the same period as the ultrasound period. Therefore, the electric signal corresponding to the intensity of the scattered light receives a modulated sound at the same frequency as the oscillation frequency of the ultrasonic wave.

This makes it possible to distinguish between solid particles and bubbles.

〔Example〕

An embodiment of the method of the present invention will be described with reference to FIGS. 1 and 2.

A measurement cell 4 made of glass, quartz, ruby, sapphire, etc. is prepared, and a sample liquid is allowed to flow in the entire lengthwise direction at a constant flow rate. Nine laser beams irradiated from a light source 1 are converged by a converging lens 2, become highly dense, and converged within a cell 4 perpendicular to the flow of the sample at a constant flow rate.

Further, an ultrasonic transducer 3 is arranged perpendicularly to the cell in contact with the cell, and ultrasonic waves are applied perpendicularly to the flow of the sample. When the sample passes through the cell at a constant flow rate, it will receive both focused laser light and vibrations caused by ultrasonic waves.If solid particles or air bubbles are present, the sample will pass through cell 4 and the laser light will emit light. Causes diffuse reflection. The laser light that has passed through the entire cell is
It is blocked by a beam stop 6. The scattered laser light that caused the diffused reflection is sent to the condenser lens 7 and then to the photomultiplier tube 8.
are collected in. The nine scattered lights collected by the photomultiplier tube have two types of waveforms A and A from particles and bubbles, as shown in Figure 2.
The signal is clearly divided into B and sent to the signal processing circuit 9. In the signal processing circuit 9, solid fine particles and bubbles are distinguished, and the particles are sorted by particle size.

Furthermore, by changing the material of the cell depending on the sample to be measured, any sample (for example, a highly corrosive sample) can be measured, and the laser beam can be replaced with other powerful light beams.

FIG. 6 is a principle diagram of a conventional method for measuring fine particles in a liquid using light scattering or ultrasonic scattering. A sample liquid Lt is flowed into the light transmittance measurement cell 4 in the direction of the arrow, and the sample liquid Lt is directed toward this liquid. A strong light beam or ultrasonic wave 1 is applied. Scattered light or scattered waves S are generated from fine particles in a liquid, and based on the intensity of this, the size and number of the fine particles can be determined, but since scattered waves are generated from both solid fine particles and air bubbles, it is not possible to distinguish between the two. It has its drawbacks. A method that compensates for this drawback is the light blocking method, and this principle is shown in Figure 4.
As in Fig. 3, the sample liquid L't- is poured into the measurement cell 4, and the light beam 1 is applied from a direction perpendicular to this to observe the shadow Ii of the fine particles G on the light receiving surface P, but no bubbles can be observed. It is something.

〔Effect of the invention〕

According to the method of the present invention, solid particles and bubbles can be extracted as waveforms showing clear differences, and along with advances in waveform processing technology, it is possible to simultaneously know the dimensions and quantities of solid particles and bubbles. This allows for much more precise liquid management than conventional methods.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the method according to the present invention; Fig. 2 shows the pulse waveforms of solid particles and bubbles obtained by the apparatus shown in Fig. 9; Fig. 6 shows the conventional light scattering method and ultrasonic FIG. 4 is a diagram showing the principle of the conventional light blocking method. 1...Re? - Source 2... Converging lens 3...
・Ultrasonic transducer 4...Measurement self-condensing lens 8...Photomultiplier tube 9...Signal processing circuit L...Sample liquid patent applicant Toyoko Kagaku Co., Ltd. Figure 1 Time limit Sample liquid tank diagram 3

Claims (1)

[Claims] A liquid is flowed at a constant speed, a light beam is focused and irradiated onto fine particles suspended in the liquid, the intensity of the scattered light from the fine particles is converted into an electrical signal, the particle size of the fine particles is measured, and the irradiated light is In a particle measurement method that counts the number of particles passing through, a pressure wave caused by ultrasonic vibration is also applied to the irradiation measurement area where the light beam is focused, and the volume of the bubbles existing in the measurement area is A method for measuring particles, characterized in that the electric signal wave based on the intensity of the scattered light is modulated with an ultrasonic frequency to distinguish between air bubbles and solid particles.