JP3153132B2 - Liquid particle detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a submerged particle detector for separating particles and bubbles in a liquid containing particles and bubbles and detecting the particle diameter and the number of particles and bubbles.

[0002]

2. Description of the Related Art An in-liquid particle detection device can measure minute particles contained in a sample liquid in real time, and can obtain measurement results with little individual difference. In addition, it is possible to measure a liquid having extremely high cleanliness, such as one particle per liter. And it is used for particle detection in many fields, for example, in the fields of electronics industry, precision machinery, medicine, food and the like.

[0003] These liquids may contain air bubbles, and there is a strong demand to measure and manage particles in the liquids containing air bubbles. Examples of the liquid containing bubbles include a stirred liquid, a liquid containing a surfactant, and a liquid that easily foams such as beer and carbonated beverages.

[0004]

However, in the conventional apparatus for detecting particles in liquid, since particles and bubbles cannot be distinguished, it is difficult to selectively count only particles in the sample liquid containing bubbles. It was possible. Therefore, it was not possible to control the particle concentration of the sample liquid in which particles and bubbles were mixed.

The present invention has been made in view of such problems of the prior art, and an object of the present invention is to distinguish between particles and bubbles in a sample liquid and to count them in a liquid. It is intended to provide a particle detection device.

[0006]

According to a first aspect of the present invention, there is provided a first and a second means for outputting a signal corresponding to a particle diameter of particles or bubbles existing in a sample liquid passing through a flow path. A second particle detecting unit, a liquid temperature changing unit disposed in a flow path between the first and second particle detecting units to cool or heat a sample liquid passing therethrough to a predetermined temperature, and a particle such as a particle or a bubble. a signal processing means for calculating the diameter and the particle number, the signal
Signal processing means for comparing the output signal of the first particle detection means with the output signal of the first particle detection means.
Comparing the output signals of the second particle detection means,
The peak value of the output signal of the particle detection means is equal to the second particle detection value.
When the peak value of the output signal of the means is substantially equal to the particle corresponding signal
A peak value comparison circuit that outputs
And a particle count display unit for counting and displaying the child correspondence signal .

According to a second aspect of the present invention, a sample liquid passing through a flow path is provided.
Outputs signals corresponding to the particle size of particles and bubbles existing in the body.
First and second particle detecting means for applying force;
The sample that is installed in the flow path between the two particle detection means and passes
Liquid temperature changing means for cooling or heating the liquid to a predetermined temperature
And signal processing means for calculating the particle size and number of particles and bubbles
A step, wherein the signal processing means comprises a first particle detecting means.
The output signal of the stage is compared with the output signal of the second particle detection means.
The peak value of the output signal of the first particle detecting means is
When the peak value of the output signal of the second particle detecting means is substantially equal to
And outputs a particle correspondence signal when the first
Peak value of output signal and output signal of the second particle detection means
To output a bubble response signal when there is a difference in the peak values
Value comparison circuit and the particle corresponding signal of this peak value comparison circuit.
A particle counting display unit for counting and displaying, and the peak value comparing circuit
From the bubble count display that counts and displays the air bubble corresponding signal
It becomes .

According to a third aspect of the present invention, there is provided the apparatus for detecting particles in liquid according to the first or second aspect , wherein the first particle detecting means includes:
The sample liquid is supplied between the first and second peak value comparing circuits.
The first particles only for the time required to pass between the two particle detecting means.
Even if a delay circuit for delaying the output signal of the
Good .

According to a fourth aspect of the present invention, there is provided the apparatus for detecting particles in liquid according to the first, second or third aspect, wherein
The particle detection means can be a light scattering type particle detector
You .

[0010]

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 shows a first embodiment of the present invention .
Diagram submerged particle detector in accordance with the embodiment, FIG. 2
FIG. 3 is a configuration diagram of a submerged particle detection device according to a second embodiment of the present invention , FIG. 3 is a characteristic diagram showing the solubility of air in water, and FIG. 4 is a graph showing the particle size and light scattering intensity of particles contained in the liquid. FIG. 5 is a characteristic diagram showing the relationship, and FIG. 5 is a configuration diagram of an example of the particle detection means.

As shown in FIG. 1, a first embodiment of the present invention is shown.
The liquid particle detection device 1 according to the embodiment includes a first light scattering type particle detector 2, a cooler 3 for cooling a passing sample liquid to a predetermined temperature, a second light scattering type particle detector 4, and a signal processing unit 5. And a flow control unit 6. Here, the first and second light scattering type particle detectors 2 and 4 are the same, detect scattered light emitted from particles or bubbles in the sample liquid when irradiating the sample liquid with light, and detect the intensity of the scattered light. To output an electric pulse signal having a wave height corresponding to. Note that, as is well known, the greater the particle size of the particles and bubbles, the higher the intensity of the scattered light emitted by the particles and bubbles.

The signal processing unit 5 compares the peak value A of the electric pulse output from the first light scattering type particle detector 2 with the peak value B of the electric pulse output from the second light scattering type particle detector 4. It comprises a pulse peak value comparison circuit 7, a particle count display section 8 for counting and displaying the number of particles, and a bubble count display section 9 for counting and displaying the number of bubbles.

The pulse peak value comparing circuit 7 compares the peak value A of the output pulse of the first light scattering type particle detector 2 with the peak value B of the output pulse of the second light scattering type particle detector 4, and compares them. When the peak values A and B are substantially equal (A ≒ B), a pulse corresponding to the particle is output, and the peak value A of the output pulse of the first light scattering type particle detector 2 is equal to that of the second light scattering type particle detector 4. If the peak value of the output pulse is larger than B (A> B), a bubble-corresponding pulse is output.

The flow rate control means 5 controls whether the sample liquid is the first liquid.
In order to connect the light scattering type particle detector 2, the cooler 2, and the second light scattering type particle detector 4, and to control the flow path 10 constituting the submerged particle detection device 1 to flow at a desired constant speed. Is provided. In addition, when the particle detection in the plant is performed by inserting the submerged particle detection device into a part of the flow path of the plant and the pressure of the sample liquid in the plant flow path is constant, the flow control means 5 is necessarily provided. No need.

Particle counting display 8 and bubble counting display 9
Counts the particle-corresponding pulse and the bubble-corresponding pulse output from the pulse crest value comparison circuit 7, and displays the counting result as the number of particles and the number of bubbles.

The apparatus for detecting particles in liquid 1 configured as described above
The operation of will be described. When a sample liquid containing particles or air bubbles is introduced into the particle-in-liquid detection device 1, when the sample liquid passes through the first light-scattering particle detector 2, the first light-scattering particle detector 2 And outputs an electric pulse corresponding to the particle size. The cooler 3 cools the sample liquid to a predetermined temperature. Then, the sample liquid cooled by the cooler 3 is
When passing through the light scattering type particle detector 4, the second light scattering type particle detector 4 outputs an electric pulse corresponding to the particle diameter of particles or bubbles contained in the sample liquid.

When the particles pass through the submerged particle detection device 1, the particles do not change in size even if they are cooled.
The peak values A and B of the electric pulses output by the first and second light scattering type particle detectors 2 and 4 do not change. Note that the first and second light scattering particle detectors 2 and 4 are kept for a time sufficiently longer than the time when the particles or bubbles pass from the first light scattering particle detector 2 to the second light scattering particle detector 4. If the particles or bubbles can be detected and the concentration or ratio of the particles or bubbles is stable over time, that is, if the concentration distribution of the particles or bubbles and the ratio of the particles or bubbles are substantially uniform, the first and second light beams are detected. There is no problem even if the timings of the electric pulses output by the scattering particle detectors 2 and 4 are shifted.

The electric pulse output from the first light scattering type particle detector 2 and the electric pulse output from the second light scattering type particle detector 4 are input to a pulse peak value comparison circuit 7. When the peak values A and B of these electric pulses are substantially the same (A ≒ B), the pulse peak value circuit 7 outputs a particle-corresponding pulse. Therefore, when the sample liquid has passed through the in-liquid particle detection device 1, the number of particles contained in the sample liquid is displayed on the particle count display unit 8.

On the other hand, when air bubbles pass through the liquid particle detection device 1, since the air bubbles are cooled and the particle diameter is reduced, the peak value A of the electric pulse output from the first light scattering type particle detector 2 is obtained. Is larger than the peak value B of the electric pulse output from the second light scattering type particle detector 4.

One of the reasons is that the solubility of a gas in a liquid (the amount of gas dissolved in the liquid) decreases as the temperature decreases. When a gas is present in a sample liquid, a part of the gas is dissolved in the liquid, and a part that cannot be dissolved in the liquid is a bubble, and the particle size of the bubble at this time depends on the solubility. FIG. 2 shows the case where air bubbles are present in water.

The second reason is that, as shown in FIG. 3, when particles or bubbles are irradiated with light, the light scattering intensity generated by the particles or bubbles depends on the particle size of the particles or bubbles. This is because the larger the value, the higher the light scattering intensity. In particular, when the particle size is small, the light scattering intensity is proportional to the sixth power of the particle size.

For example, when the bubble is the first light scattering type particle detector 2
Assuming that the initial temperature of the sample liquid is 40 ° C. when the sample liquid is cooled to 20 ° C. by the cooler 3, the solubility at 40 ° C. is 0.014,
Is 0.019. This means that the particle size of the bubbles at 40 ° C. is 1.1 times the particle size at 20 ° C. Further, assuming that the bubble diameter is about 0.2 to 0.3 μm, the light scattering intensity is 6
Since the light scattering intensity at 20 ° C. and the light scattering intensity at 40 ° C. are compared with each other, the latter is 1.8 times as large as the former.

In the case of bubbles, the peak value A of the electric pulse output from the first light scattering type particle detector 2 is larger than the peak value A of the electric pulse output from the second light scattering type particle detector 4. It is larger than the peak value B. In this case, the pulse peak value circuit 7
Outputs a bubble-corresponding pulse, so that the number of bubbles is displayed on the bubble count display section 9 when the bubbles pass through the liquid particle detection device 1.

FIG. 2 shows a second embodiment of the present invention.
In the liquid particle detection device 11 according to the embodiment, in the liquid particle detection device 1 according to claim 3, the sample liquid is the first light scattering type between the first light scattering type particle detector 2 and the pulse peak value comparison circuit 7. A delay circuit 12 is provided for delaying the output signal of the first light scattering type particle detector 2 by the time passing between the particle detector 2 and the second light scattering type particle detector 4.

When the concentration or ratio of the particles or bubbles of the sample liquid is low and the concentration distribution of the particles or bubbles and the ratio of the particles or bubbles are not uniform, the electric pulse output from the first light scattering type particle detector 2 is used. And the timing of the electric pulse output by the second light scattering type particle detector 4 becomes a problem.
Therefore, the electric pulse output from the first light scattering type particle detector 2 and the electric pulse output from the first light scattering type particle detector 2 are delayed by delaying the electric pulse output from the first light scattering type particle detector 2 by the delay circuit 12 described above. The electric pulse output from the heater 4 is simultaneously input to the pulse peak value comparison circuit 7.

The pulse peak value comparing circuit 7 includes a delay circuit 12
Is compared with the peak value B of the electric pulse output from the second light scattering type particle detector 4,
When the peak value A of the electric pulse output from the delay circuit 12 is substantially equal to the peak value B of the electric pulse output from the second light scattering type particle detector 4 (A ≒ B), a pulse corresponding to the particle is output, and the delay circuit is output. When the peak value A of the electric pulse output from 12 is greater than the peak value B of the electric pulse output from the second light scattering type particle detector 4 (A> B), a bubble-corresponding pulse is output.

The liquid particle detecting device 1 configured as described above
1 will be described. When a sample liquid containing particles or air bubbles is introduced into the particle-in-liquid detection device 1, when the sample liquid passes through the first light-scattering particle detector 2, the first light-scattering particle detector 2 And outputs an electric pulse corresponding to the particle size. The cooler 3 cools the sample liquid to a predetermined temperature. When the sample liquid cooled by the cooler 3 passes through the second light scattering type particle detector 4, the second light scattering type particle detector 4 corresponds to the particle diameter of particles or bubbles contained in the sample liquid. Output the generated electric pulse.

When the particles pass through the submerged particle detector 11, since the particles do not change in size even if they are cooled, the first and second light scattering type particle detectors 2 and 4 output the respective particles. The peak values A and B of the generated electric pulse do not change. However, since the timings of these electric pulses are shifted, the electric pulse output from the first light scattering type particle detector 2 is delayed by the above-described delay circuit 12, so that the first light scattering type particle detector 2 outputs And the electric pulse output from the second light scattering type particle detector 4 are input to the pulse peak value comparison circuit 7 at the same time.

When the peak values A and B of these electric pulses are substantially the same (A ≒ B), the pulse peak value circuit 7 outputs a particle-corresponding pulse. Therefore, when the sample liquid has passed through the in-liquid particle detection device 11, the number of particles contained in the sample liquid is displayed on the particle count display section 8.

When the air bubbles pass through the submerged particle detector 11, the peak value A of the electric pulse output from the first light scattering type particle detector 2 is higher than that of the second light scattering type particle detector. 4
Is larger than the peak value B of the output electric pulse. Then
Since the pulse crest value circuit 7 outputs a bubble-corresponding pulse, the number of bubbles is displayed on the bubble count display unit 9.

As described above, the scattered light emitted by the particles in the sample liquid does not change even when the temperature of the sample liquid decreases, whereas the scattered light emitted by the bubbles in the sample liquid decreases when the temperature of the sample liquid decreases. If the number of pulse corresponding to particles and the number of pulses corresponding to bubbles in the pulse peak value comparison circuit 7 are counted, particles and bubbles can be separately counted.

In the above-described embodiment, the temperature of the sample liquid is changed from a high temperature to a low temperature by using the cooler 2. Since it may be provided, a heater may be used instead of the cooler 2. However, in this case, when the peak value A of the electric pulse output from the first light scattering type particle detector 2 is smaller than the peak value B of the electric pulse output from the second light scattering type particle detector 4, the pulse The peak value comparison circuit 7 must output a bubble-corresponding pulse.

In the above embodiment, the light scattering particle detectors 2, 4 are used as the first and second particle detecting means.
However, since it is only necessary to use a particle detector that outputs an electrical signal corresponding to the size of the particles, another type of particle detector may be used.

For example, a so-called light-blocking type in which light is applied to a channel portion, and the particle size of the particles is measured by measuring the intensity of irradiation light reduced by the passage of particles through the channel portion. As shown in FIG. 5, the electrolyte solution 21 is passed through a pinhole 23 formed in a partition wall 22 made of an insulator. May be used.

[0036]

As described above, according to the first aspect of the present invention, only particles of the sample liquid containing bubbles and particles are measured.
You can display this value by counting .

According to the second aspect of the present invention, bubbles and particles are
Particles and bubbles of the mixed sample liquid are separately measured.
You can count and display these values .

According to the third aspect of the invention, particles of the sample liquid
Or the concentration and ratio of bubbles are low, and the concentration of particles or bubbles
If the distribution or the ratio of particles or bubbles is not uniform
Also, particles and bubbles in the sample liquid containing bubbles and particles
Can be counted separately to show these values.
I can .

According to the fourth aspect of the present invention, bubbles and particles are
Highly accurate detection of particles or bubbles in mixed sample liquids
Can be .

[0040]

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a submerged particle detection device according to a first embodiment of the present invention .

FIG. 2 is a configuration diagram of a submerged particle detection device according to a second embodiment of the present invention .

FIG. 3 is a characteristic diagram showing solubility of air in water.

FIG. 4 is a characteristic diagram showing a relationship between a particle size of particles contained in a liquid and a light scattering intensity.

FIG. 5 is a configuration diagram of an example of a particle detection unit.

[Explanation of symbols]

Reference numerals 1, 11: liquid particle detecting device, 2: first light scattering type particle detector (first particle detecting means), 3: cooler (liquid temperature changing means), 4: second light scattering type particle detector (Second particle detecting means), 5: signal processing unit (signal processing means), 6: flow rate control unit, 7: pulse peak value comparison circuit (peak value comparison circuit), 8: particle count display unit, 9: bubble Count display, 10
... a flow path, 12 ... a delay circuit.

Claims (4)

(57) [Claims] 1. First and second particle detecting means for outputting a signal corresponding to the particle diameter of particles or bubbles existing in a sample liquid passing through a flow path, and first and second particle detecting means comprising a fluid temperature changing means for cooling or heating the sample liquid to a predetermined temperature which is installed in the flow path passes between the signal processing means for calculating the particle size and particle number of such particles or bubbles, the signal
The processing means includes an output signal of the first particle detection means and the output signal of the first particle detection means.
The output signal of the second particle detecting means is compared, and the first particle is detected.
The peak value of the output signal of the child detecting means is
When the peak value of the output signal of the stage is approximately equal to the
Output peak value comparison circuit and particles of this peak value comparison circuit
A liquid particle detection device, comprising: a particle counting display unit that counts and displays a corresponding signal . 2. Particles present in a sample liquid passing through a flow path.
First and second signals that output signals corresponding to the particle size of particles and bubbles
Second particle detecting means, first and second particle detecting means
Set the sample liquid passing through the
Cooling or heating liquid temperature changing means and particles or bubbles
Signal processing means for calculating the particle size and the number of particles;
The processing means includes an output signal of the first particle detection means and the output signal of the first particle detection means.
The output signal of the second particle detecting means is compared, and the first particle is detected.
The peak value of the output signal of the child detecting means is
When the peak value of the output signal of the stage is approximately equal to the
And a peak value of an output signal of the first particle detecting means.
There is a difference in the peak value of the output signal of the second particle detection means
A peak value comparison circuit that outputs a bubble response signal when
Particles that count and display the particle corresponding signal of the peak value comparison circuit
The counting display unit and the signal corresponding to the bubble of the peak value comparing circuit are measured.
An apparatus for detecting particles in liquid, comprising a bubble counting and displaying section for counting and displaying . 3. The ratio between the first particle detecting means and the peak value.
The sample liquid is detected between the first and second particles during the comparison circuit.
The first particle detecting means is only used for the time passed between the means.
3. A device according to claim 1, further comprising a delay circuit for delaying the output signal.
The device for detecting particles in liquid according to the above. 4. The first and second particle detecting means,
4. The liquid particle detection device according to claim 1, which is a light scattering type particle detector .