JPH043251Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an in-liquid particulate measurement device that detects and measures particulates in a liquid.

[Conventional technology]

Conventional in-liquid particle measuring devices are classified into light blocking methods, light scattering methods, dynamic light scattering methods, electrical resistance methods, acoustic methods, etc. based on the particle detection principle.

Except for the particle measuring device based on the acoustic method, in the particle measuring device based on other measurement principles, the particle detection section detects air bubbles present in the liquid.
Difficult to distinguish from solid particles to be detected;
So-called false counting occurs in which air bubbles are counted as particles, and a decrease in measurement accuracy is unavoidable. Volatile organic solvents, hydrogen peroxide, ammonia water, etc.
When measuring particles in liquid samples that tend to generate bubbles,
The occurrence of false counting was a particularly important problem.

It should be noted that with regard to a device based on the acoustic method, it is possible to obtain a certain degree of knowledge about the material composition of particles due to its detection principle, and therefore it is possible to distinguish between air bubbles and solid particles.

So far, as a countermeasure for such bubbles,
For example, there is a vacuum degassing method in which a liquid sample is degassed under reduced pressure before measurement.

FIG. 3 shows a conventional example in which a vacuum degassing method is applied to a light blocking method or light scattering method, and a batch sampling method for measuring in-liquid particles.

Reference numeral 1 denotes a pressurized tank in which a container 3 containing a liquid sample 2 is installed. 4 is a pressurizing pump that produces pressurized air, and 5 is a pressurizing pipe that sends pressurized air into the pressurizing tank 1 in order to forcefully feed the liquid sample 2 to a particle detection section 7, which will be described later. Reference numeral 6 denotes an introduction pipe constituting an inflow channel system guided from inside the pressurized tank 1 into the detection section 7. A three-way valve 30 and a pressure reducing pump 31 are added to the pressurizing pipe 5. Before measurement, the vacuum pump 31 is operated to reduce the pressure of the liquid sample 2 to promote the generation of bubbles in advance and remove air molecules and bubbles dissolved in the liquid sample 2.

Various configurations of the detection unit 7 are known based on the particle detection principle. For example, if it is a light scattering method,
Roughly, it consists of an irradiation system that irradiates the sample with light, a channel system through which the sample passes, and a light receiving system that guides scattered light generated by fine particles to a light receiving element.

Pulse signals corresponding to fine particles from the detection section 7 are processed by an amplifier 8 and a multi-channel classifier 9, and a particle count value for each particle size classification is displayed on a display 10. Reference numeral 11 denotes a discharge pipe that constitutes a discharge flow path system led out from the detection section 7. Reference numerals 13 and 14 indicate valves, and by operating these valves 13 and 14, the liquid sample 2 can be introduced into the detection section 7, the liquid sample 2 can be stored in the measuring cylinder 15 to obtain the measurement volume, or the liquid sample 2 can be discharged. do.

Note that 16 is a pressure gauge that indicates the pressure inside the pressurized tank 1, and 17 is a regulator.

In addition to the reduced pressure degassing method, methods of heating and degassing a liquid sample and subjecting the liquid sample to ultrasonic waves have been used to prevent the generation of bubbles.

However, all of the three methods described above are effective in removing air molecules dissolved in a liquid sample, and therefore can be used as a countermeasure against bubbles composed of air molecules, but they tend to vaporize and form bubbles with vapor. It is not a measure against bubbles for volatile liquid samples. In addition, all of the three methods described above require large and complicated equipment. Furthermore, before measurement, for the liquid sample,
Since some kind of processing or manipulation was required, there was a risk that the number of particles to be measured in the liquid sample would change.

[Purpose of invention]

The purpose of the present invention is to promote the disappearance of existing bubbles in a liquid sample in a particulate detection unit, and to further prevent the generation of new bubbles, thereby preventing the occurrence of false counting.

Another object of the present invention is to facilitate flow rate adjustment even for low viscosity liquid samples.

[Means for solving problems]

In order to achieve the above object, in the present invention, a resin tube 12 with a small inner diameter is interposed in the discharge channel system through which the liquid sample passes.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an embodiment in which the present invention is applied to a light blocking type or light scattering type and batch sampling type in-liquid particle measuring device.

Reference numeral 1 denotes a pressurized tank in which a container 3 containing a liquid sample 2 is installed. 4 is a pressurizing pump that produces pressurized air, and 5 is a pressurizing pipe that sends pressurized air into the pressurizing tank 1 in order to forcefully send the liquid sample 2 to a particle detection section 7, which will be described later. Reference numeral 6 denotes an introduction pipe constituting an inflow channel system guided from inside the pressurized tank 1 into the detection section 7.

Pulse signals corresponding to fine particles from the detection section 7 are processed by an amplifier 8 and a multi-channel classifier 9, and a particle count value for each particle size classification is displayed on a display 10. Reference numeral 11 denotes a discharge pipe that constitutes a discharge flow path system led out from the detection section 7. 12 is the discharge pipe 1
It is a resin tube with a narrow inner diameter that is connected to the inside of the tube. Reference numerals 13 and 14 indicate valves, and by operating the valves 13 and 14, a liquid sample is introduced into the detection section 6, the measured volume is determined by storing it in the measuring cylinder 15, or the liquid sample is discharged.

Next, we will discuss the effect.

The liquid sample 2 is led from the pressurized tank 1 through the introduction pipe 6 to the detection section 7, where fine particles are detected, and the measurement results are displayed on the display 10. After that, the liquid sample 2 is transferred to the discharge pipe 11
However, due to the presence of the resin tube 12 with a small inner diameter, the resistance of the pipe line to the flow of the liquid sample becomes large. Therefore, liquid sample 2
When the liquid passes through the resin tube 12 having a small inner diameter, a pressure loss occurs. Due to this pressure loss, the pressure of the liquid sample 2 in the detection section 7 can be kept high.

FIG. 2 shows another embodiment in which the present invention is applied to an on-line sampling system for measuring particles in liquid. In the above embodiment, a case was explained in which a graduated cylinder was used to measure the liquid volume, but in this embodiment, a flow meter 18 is used.
Furthermore, instead of the pressurized tank 1 used as a means for sending out the liquid sample 2 in the above embodiment, in this embodiment, the pressure in the high pressure system piping 19 is used to detect the liquid sample 2 flowing inside the system piping 19. It is sent to Department 7.

In addition, in FIG. 2, the resin tube 12 with a narrow inner diameter is placed after the flowmeter, which increases the liquid pressure inside the flowmeter and makes the flow rate measurement less susceptible to errors caused by air bubbles.

[Effect of idea]

As explained above, according to the present invention, since a resin tube with a narrow inner diameter is interposed in a part of the discharge channel system, the pressure of the liquid inside the detection section increases, the boiling point of the liquid sample increases, and the gas Due to the increased solubility in the liquid, gas bubbles already present in the liquid sample disappear or new generation is prevented. This effect is effective for both bubbles made of air molecules and bubbles made of vapor of a liquid sample. Therefore, the effect of improving the problem of false counting due to air bubbles can be obtained with a very simple configuration, and it becomes possible to improve measurement accuracy.

Furthermore, since the present invention can obtain the above effects without performing any operations on the liquid sample before measurement, there is no possibility that the number of particles to be measured in the liquid sample will change due to the implementation of the present invention. .

In addition, since a resin tube with a narrow inner diameter is used as a means for increasing the resistance of the conduit, the magnitude of pressure loss can be adjusted by changing the length of this resin tube.
The present invention can be easily applied to various liquid samples with different boiling points under optimal conditions.

Furthermore, since a resin tube with a small inner diameter is used and is highly flexible, even if the resin tube is quite long, it can be easily incorporated into the device by bending it.

Furthermore, if polytetrafluoroethylene is used as the resin material, chemical resistance will be greatly improved.

Furthermore, in conventional liquid particle measuring devices, it was not easy to adjust the flow rate of liquid samples by adjusting the delivery pressure for low-viscosity liquid samples, but in the liquid particle measuring device to which the present invention is applied, Therefore, even for a low-viscosity liquid sample, the flow rate of the liquid sample can be easily adjusted by adjusting the delivery pressure.

Further, in the embodiment shown in FIG. 2, since the resin tube with a small inner diameter is placed after the flowmeter, the liquid pressure inside the flowmeter increases, and the flow measurement is less susceptible to errors caused by air bubbles.

As described above, according to the present invention, the problem of false counting due to the generation of bubbles can be solved despite the extremely simple configuration, and in addition, many effects can be obtained as described above.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 is a block diagram showing another embodiment.
FIG. 3 shows an example of a conventional particle measuring device. 2...Liquid sample, 7...Detection section, 11...Discharge pipe (discharge channel system), 12...Resin tube with narrow inner diameter.

Claims (1)

[Scope of utility model registration request] A discharge channel system 11 through which the liquid sample 2 is drawn out from the detection unit 7 that detects particulates in the liquid sample 2.
A resin tube 12 with a narrow inner diameter is interposed in the tube,
A particulate measuring device characterized in that the presence of this resin tube 12 increases the liquid pressure within the detection section 7.