JP2003161689A - Probe for detecting states of particles and aggregation monitoring apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a probe for detecting states of particles with a simple structure, which can easily carry out the calibration of a measuring system. <P>SOLUTION: The apparatus is provided with a first optical fiber (light emitting section) which emits laser from the edge into water to be tested, a second optical fiber (photo detecting section) which guides scattering light occurring because of collisions of the laser with the particles in the water to be tested from the edge into a detecting section, a table (support member) which supports both the optical fibers in such a condition that a laser projecting region and a photo receiving region of the scattering light cross each other and specifies a region for measuring the state of the particles in the water to be tested, and a fluid guiding opening which is formed in the table so that pure water or air for the calibration introduced from the outside is injected to an area including each edge of the optical fibers and the specified measurement region and so that the area is filled with the pure water or the air for the calibration. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to coagulated water containing flocs sampled from a coagulation process (test water).
The present invention relates to a particle state detection probe and an agglutination monitor device suitable for measuring the state of particles contained therein.

[0002]

[Related Background Art] For purification treatment (water quality improvement treatment) of tap water, industrial water, sewage and drainage, for example, an aggregating agent is added to the water to be treated to agglomerate suspended substances in the water to be treated. After that, flocculated flocs are solid-liquid separated by a method such as sedimentation separation, pressure floating separation, centrifugation, sand filtration, and membrane separation. However, the agglomeration state of suspended solids in flocculated treated water (sample water) that contains flocs depends on the water quality of the water to be treated (pH and concentration of suspended solids), as well as the amount of flocculant added in the flocculation process and its stirring. It cannot be denied that it will change depending on the conditions. By the way, if the coagulation treatment conditions are not set appropriately, it may adversely affect the subsequent solid-liquid separation treatment or may deteriorate the quality of treated water after solid-liquid separation.

Therefore, conventionally, the turbidity of the test water is measured from the intensity of scattered light generated by the test water when the test water is irradiated with light, and the agglomeration state of the suspended substance in the test water is measured based on this turbidity. Has been proposed to optimize the aggregating conditions in the aggregating treatment step in real time (Japanese Patent Publication No. 5-505026). However, in this case, since only the average scattered light intensity by the test water is measured, it is impossible to distinguish between the scattered light by the aggregates in the test water and the scattered light by the non-aggregates (suspended substances). There is.

Incidentally, the intensity of the scattered light is proportional to the number of particles of the suspended substance in the test water, and is 4 times the particle size.
~ Proportional to 6th power. Then, when the agglomeration of the suspended substance progresses in the aggregating treatment, the scattered light intensity gradually decreases as the number of particles in the test water decreases, but on the other hand, the agglomeration of the suspended substance increases the particle diameter, which causes ) The intensity of scattered light per unit increases. Therefore, in the above-mentioned measurement of the average scattered light intensity, since the scattered light due to the aggregate and the non-aggregate showing the change of the scattered light intensity as described above are mixed, the aggregated state There is a problem that you can not grasp properly.

[0005]

Therefore, the applicant of the present invention first irradiates a laser beam into the test water, and detects the scattered light generated by the collision of the laser beam with the particles in the test water in a minute measurement area. By doing so, an aggregation monitoring device was proposed in which each scattered light component due to an aggregate and an unaggregate is distinguished from each other and the state of particles in test water is accurately detected (Japanese Patent Application No. 2000-392442). In this device, a first optical fiber that guides laser light and emits from the end face thereof, and a second optical fiber that guides scattered light introduced from the end face to a photoelectric conversion element
By making each end face of the optical fiber close to each other and attaching it to the support member so that the central axes of the end faces of the respective optical fibers intersect, a probe with a minute measurement region set near the end face of the optical fiber is constructed. There is. Then, this probe is immersed in test water to detect the state of particles (the number of particles and the particle diameter) in the minute measurement region.

However, when the state of particles in the test water is detected using the above-mentioned probe, impurities contained in the test water gradually adhere to the end face of the fiber. Then, the intensity of the laser beam with which the test water is irradiated is reduced due to the contamination of the fiber end face, which causes a detection error. Moreover, the output intensity itself of the laser light may decrease due to the change over time of the light source (laser oscillator) that generates the laser light. Therefore,
In order to maintain the measurement reliability, maintenance such as cleaning dirt on the fiber end surface and calibrating the output of the laser oscillator is essential.

The present invention has been made in consideration of such circumstances, and an object thereof is to irradiate a laser beam into the test water and to scatter the scattered light generated by the collision of the laser beam with the particles in the test water. Regarding the particle state detection probe, especially for detecting the particle state with a simple configuration that can easily calibrate the measurement system against deterioration in detection accuracy due to changes in laser light output over time and dirt. It is to provide a probe and an agglutination monitor.

[0008]

In order to achieve the above-mentioned object, a particle state detecting probe according to the present invention comprises, for example, a first optical fiber which guides laser light and emits the laser light from its end face. A light projecting unit that irradiates light and scattered light that is provided in the vicinity of the light projecting unit and is generated by collision of the laser light with the particles in the test water are introduced from, for example, the end face thereof and guided to the photoelectric conversion unit. The light projecting unit (the optical fiber for projecting light) is in a state in which a light receiving unit formed of a second optical fiber, an irradiation region of the laser light by the light projecting unit, and a light receiving region of the scattered light by the light receiving unit intersect with each other. ) And a light receiving portion (optical fiber for receiving light) respectively to define the measurement region of the particle state in the test water, and fresh water for calibration provided from the support member and introduced from the outside or The air And a calibration environment setting means for ejecting the laser light emitting surface of the light section, the scattered light receiving surface of the light receiving section, and the area including the measurement area and filling the area with fresh water or air for calibration. Is characterized by.

[0009] Preferably, the calibration environment setting means introduces calibration fresh water or air that is pierced in the support member and is supplied from the outside, and the calibration environment setting means is provided from an ejection port provided in the vicinity of a measurement region defined by the support member. It is realized as a fluid introduction hole for jetting fresh water or air for calibration. At this time, a jet of fresh water or air for calibration is provided close to each end face of the first and second optical fibers, and each of the above-mentioned light is jetted by the fresh water or air for calibration jetted from the jet. It is also preferable to have a role of cleaning the end face of the fiber.

The agglutination monitor according to the present invention is constructed by using the above-mentioned particle state detecting probe, and comprises a laser beam emitting surface of the light projecting portion, a scattered light receiving surface of the light receiving portion, And in accordance with the detection output detected by using the particle state detection probe in a state in which the region including the measurement region is filled with fresh water or air for calibration,
For example, a measurement system calibrating unit is provided to calibrate the measurement system by correcting the intensity of the laser beam applied to the test water from the light projecting unit and / or the detection intensity of the scattered light received by the light receiving unit. Is characterized by.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a particle state detecting probe and an agglutination monitoring apparatus using the particle state detecting probe according to an embodiment of the present invention will be described with reference to the drawings. This agglutination monitor is, for example, by irradiating laser light into the test water that has been subjected to the agglutination treatment, by detecting the scattered light generated by the collision of the laser light to the particles in the test water, contained in the test water. Is configured to measure the state of the particles that are exposed. As schematically shown in FIG. 1, a particle state detection probe used in this agglutination monitor includes a first optical fiber 1 for irradiating a test water with laser light whose amplitude is modulated at a predetermined frequency. The second optical fiber 2 for receiving the scattered light generated by the collision of the laser light with the particles contained in the sample water is fixed to a predetermined pedestal (support member) 3 with its fiber end faces being close to each other. Have a structure.
Also, this probe is, for example, 10 to 20 mm as a whole.
It is made of medium size.

The optical fibers 1 and 2 each have a core diameter of about 0.1 mm, and are fixed to the pedestal 3 so that the central axes of the respective fiber end faces intersect at an angle of 90 °. To be done. And 0.2 to 0.4 mm at the portion where the central axes of the end faces of the optical fibers 1 and 2 intersect
A region S having a small diameter is irradiated with laser light, and the region S
It is configured to receive the scattered light generated in. The pedestal 3 also plays a role of blocking the arrival of extraneous light (natural light) entering from above the probe to the region S.

Suspended substances (microcolloid particles) in test water by an agglutination monitor using a probe having such a structure
The detection of the state of particles composed of flocs caused by agglomeration of the particles or the agglomeration thereof is performed by using the modulated laser light L output from the light emitting unit 10, for example, the laser light L amplitude-modulated at a predetermined frequency as shown in the processing concept of FIG. Irradiation into the test water through the first optical fiber 1 in the probe, and scattered light S generated when the laser light collides with particles contained in the test water is passed through the second optical fiber 2 in the probe. Detector 2
This is done by receiving light at 0.

The light emitting section 10 has, for example, a wavelength of 630n.
The laser oscillator 11 such as a laser diode that oscillates and outputs the laser beam L of m and the laser beam L that is oscillated and output by the laser oscillator 11 are 70 to 150 kHz (for example, 95 kHz).
Hz) and an amplitude modulator 12 such as a function generator that electrically performs amplitude modulation (AM modulation). Further, the detection unit 20 extracts only the above-mentioned amplitude-modulated frequency component from a photoelectric converter 21 such as a phototransistor that generates an electric signal according to the amount of received light (received light intensity) of the scattered light S and its photoelectric conversion output. A band pass filter (BPF) 22 for detecting the amplitude modulated frequency component signal F obtained by amplifying the output of the band pass filter 22 through an amplifier 23, and a detector 24 for obtaining an envelope component E thereof. It is equipped with.

The amplitude modulation of the laser light L plays a role of distinguishing from external light such as natural light mixed in the test water by modulating scattered light generated by irradiating the test water with the laser light L. ing. Therefore, by filtering the output of the photoelectric converter 21 through the bandpass filter 22, it is possible to extract only the scattered light component by the laser light L irradiated into the test water as the frequency component of the amplitude modulation. Become.

Considering the scattered light generated in the above-mentioned minute region S irradiated with the laser light L, the intensity of the scattered light generated by the minute colloid particles made of the suspended substance in this region S is equal to that of the minute colloid particles. It increases in proportion to the number of. The number of fine colloidal particles decreases as the flocculation progresses and flocs having a large particle size are generated. On the other hand, flocs are aggregates of fine colloidal particles, and thus the number increases as aggregation progresses, but the number is far smaller than that of fine colloidal particles. Therefore, it is extremely unlikely that the above-mentioned flocs are present in the minute area S described above, and rarely enters the minute area S. However, the frequency with which the flocs enter the minute region S increases as the number of flocs increases as the aggregation progresses.

Therefore, when the intensity of the scattered light in the minute area S is measured using the probe having the above-mentioned structure, FIG.
As the concept is shown in (c) to (c), as the number of fine colloid particles decreases and the number of flocs gradually increases due to the progress of the aggregation of suspended substances, the fine region S detected by the probe 8 is detected.
The intensity of the scattered light may temporarily increase due to the above-mentioned flocs, but it generally decreases. Therefore, except for the case where the scattered light intensity is temporarily increased due to the presence of flocs, focusing on the overall scattered light intensity,
The scattered light intensity at that time can be regarded as indicating the number of unaggregated colloidal particles.

The minimum value detection circuit 25 shown in FIG.
Based on such a viewpoint, by detecting the minimum value of the envelope component E of the signal F of the amplitude modulation frequency component obtained from the photoelectric conversion output corresponding to the intensity of the scattered light described above, The state of particles (the number of unaggregated colloidal particles) is obtained. Note that if attention is paid to the period in which the intensity of scattered light temporarily increases due to flocs, it becomes possible to determine the number of flocs generated by aggregation (the density of flocs in the test water), and the temporary scattered light intensity It is also possible to determine the particle size of flocs from the size.

Basically, as described above, the first optical fiber 1 for irradiating the laser beam and the second optical fiber 2 for receiving the scattered light are attached to the pedestal 3 which is a supporting member thereof. In the particle state detection probe, the feature of the present invention is that it supports optical fibers 1 and 2 as shown in the embodiment in FIG.
2, a pedestal (support member) 3 in which a minute region S is set to detect the state of particles in the test water at a position where the central axes of the respective end faces intersect, and a fresh water supply source (air supply source) 3 outside the pedestal 3
The fresh water (air) supplied from the optical fiber 1, 2
Is provided with a fluid introduction hole (calibration environment setting means) 5 that jets to each end face and a region C including the minute region S and fills the region C with fresh water (air).

The fluid introduction hole 5 is formed in the pedestal 3 and is provided with a jet port 6 for jetting fresh water (air) in close proximity to each end face of the optical fibers 1 and 2, and through a tube or the like. And is connected to the fresh water supply source (air supply source) 30. In particular, the jet port 6 provided at the tip of the pedestal 3 is set so as to jet fresh water (air) along each end face of the optical fibers 1 and 2, and the jet flow of the fresh water (air) causes light to be emitted. It also plays a role of removing dirt attached to the end faces of the fibers 1 and 2.

According to the probe having such a fluid introduction hole 5, the probe is immersed in the test water, and the scattered light is detected by irradiating the test light with the laser beam from the light emitting section 10. In the above, the fresh water supply source (air supply source) 30
When fresh water (air) supplied from the fluid through the fluid introduction hole 5 is ejected from the ejection port 6, the fresh water (air) pushes away the test water and includes each end face of the optical fibers 1 and 2 and the minute region S. A fresh water lump (air pool) is formed in the area C, and the area C is filled with fresh water (air). If the scattered light generated in the minute area S is detected in this state, the scattered light intensity indicates the state of fresh water (air) that is unrelated to the test water, so the measurement system is calibrated with this scattered light intensity. It can be used as an evaluation value for doing. Therefore, as shown in FIG. 3, the agglutination monitor device equipped with the above-mentioned probe synchronizes with the operation of the fresh water supply source (air supply source) 30 and the detection unit 20.
From the output (scattered light intensity) of Eq.

According to the agglomeration monitor thus constructed, the fresh water supply source 30 is actuated so as to collect fresh water lumps in the end faces of the optical fibers 1 and 2 at the probe tip and in the region C including the minute region S. By forming and operating the evaluation unit 31 in synchronization with the operation of the fresh water supply source 30, the light emitting unit 10 is output from the output (scattered light intensity) of the detection unit 20.
It is possible to evaluate the characteristics of the measurement system from the detection unit 20 to the detection unit 20. If, for example, the output intensity of the laser light in the light emitting unit 10 is adjusted or the light receiving sensitivity of the scattered light in the detection unit 20 is adjusted (corrected) according to the scattered light intensity obtained from the fresh water mass, the It is possible to simplify the measurement system and effectively calibrate it.

If the scattered light intensity obtained from the fresh water mass is much lower than the calibration reference value (scattered light intensity under normal conditions), for example, some kind of light is emitted to the light emitting section 10 that outputs laser light. If a failure occurs or the end faces of the optical fibers 1 and 2 are badly contaminated, laser light emission and / or
Alternatively, it can be determined that the scattered light is not normally received. Therefore, in such a case, the light emitting unit 10
If it is not possible to wipe off the dirt on the end surfaces of the optical fibers 1 and 2 even if the maintenance is performed or if the fresh water is ejected, cleaning of the end surfaces by another means may be prompted. For cleaning the end faces of the optical fibers 1 and 2 (cleaning of the probe), the probe may be pulled up from the sample water and a dedicated brush or the like may be used.

Thus, according to the agglomeration monitor using the probe for detecting the particle state constructed as described above, the characteristics of the measurement system from the light emitting section 10 to the light receiving section 20 can be easily calibrated. Moreover, at the time of this calibration, it is possible to clean each end surface of the optical fibers 1 and 2 by using clean water (air) ejected from the ejection port 6 to remove the dirt attached to the end surfaces. So while keeping the probe clean,
The measurement system can be easily calibrated, and the maintenance can be facilitated.

The present invention is not limited to the above embodiment. For example, while ejecting fresh water (air) from the ejection port 6 and forming a fresh water mass (air pool) in the region C at the tip of the probe and monitoring the scattered light intensity detected,
The cleanliness of the end faces of the optical fibers 1 and 2 may be determined. Then, when the scattered light intensity reaches the normal level or reaches a predetermined level, it may be determined that the cleaning (washing) is completed. Further, the scattered light intensity is detected in a state where the region C at the tip of the probe is filled with a fresh water lump in advance, and the detected scattered light intensity is a standard value in a state where the suspended substance contained in the test water is purified by aggregating treatment ( (Reference value). Then, this standard value may be used as a target value for determining the degree of cleaning of the coagulated treated water (test water).

Further, in the embodiment, the laser light amplitude-modulated at a predetermined frequency is used as the modulated laser light for detecting the state of the particles in the test water, but the laser light is phase-modulated or frequency-modulated. You may use it.
In this case, the phase modulation component or frequency modulation component may be detected from the photoelectric conversion output according to the intensity of scattered light to detect the state of particles in the test water. In addition, the present invention can be variously modified and implemented without departing from the scope of the invention.

[0027]

As described above, according to the present invention, there is provided the calibration environment setting means for filling the region including the minute region for detecting the state of the particles of the sample water formed near the tip of the probe with fresh water or air. Therefore, the measurement system can be easily calibrated. Further, by providing the role of cleaning the fiber end face with the fresh water or air jetted into the above-mentioned region, it is possible to reliably and reliably detect the state of the particles in the test water while removing the dirt attached to the fiber end face. Therefore, practically great effects such as easily improving the measurement accuracy can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing the concept of processing for detecting the state of particles in a flocculation-treated water (fluid test water) containing flocs by an agglutination monitoring apparatus using a particle state detection probe according to the present invention.

FIG. 2 shows the state of aggregation of suspended substances (microcolloid particles),
The figure which shows typically the mode of the change of the scattered light intensity in the minute area | region S.

FIG. 3 is a schematic configuration diagram of a particle state detection probe according to an embodiment of the present invention.

[Explanation of symbols]

1 First optical fiber (projector) 2 Second optical fiber (light receiving part) 3 pedestal (support member) 5 Fluid introduction hole (calibration environment setting means) 6 spouts 30 Fresh water supply source (air supply source)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masayuki Nagao             Toyohashi 1-1, Hibarigaoka, Tenhaku Town, Toyohashi City, Aichi Prefecture             Inside the University of Technology F-term (reference) 2G059 AA05 BB05 CC19 DD12 EE02                       FF07 FF08 GG01 GG02 GG06                       HH02 HH06 JJ17 KK01 LL01                       MM01 MM03 MM14 MM15 NN01                       NN07

Claims (6)

[Claims] 1. A particle state detection probe for irradiating laser light into test water and detecting scattered light generated by collision of the laser light with particles in the test water. A light projecting unit for irradiating, a light receiving unit provided near the light projecting unit for receiving the scattered light, an irradiation region of the laser light by the light projecting unit, and a light receiving region of the scattered light by the light receiving unit. And a support member that supports the light projecting unit and the light receiving unit in a state of intersecting each other to define the measurement region of the particle state in the test water, and fresh water for calibration that is provided to the support member and is introduced from the outside. Alternatively, a calibration environment setting means for ejecting air onto the laser light emitting surface of the light projecting portion, the scattered light receiving surface of the light receiving portion, and a region including the measurement region and filling the region with fresh water or air for calibration. Equipped with Particle state detection probe according to claim. 2. The light projecting unit is a first optical fiber that guides laser light emitted from a light source and emits it from an end face thereof, and the light receiving unit detects scattered light incident from the end face thereof. The particle state detection probe according to claim 1, comprising a second optical fiber for guiding to the particle. 3. The calibration environment setting means introduces fresh water or air for calibration that is pierced in the support member and is supplied from the outside, and the calibration environment setting means is provided from an ejection port provided in the vicinity of a measurement region defined by the support member. The particle state detection probe according to claim 1, comprising a fluid introduction hole for ejecting calibration fresh water or air. 4. The calibration fresh water or air jet outlet is provided close to each end face of the first and second optical fibers, and the calibration fresh water jetted from the jet outlet. 4. The particle state detection probe according to claim 3, which plays a role of cleaning the end faces of the respective optical fibers with air. 5. An agglutination monitor configured by using the particle state detection probe according to claim 1, wherein the laser light emitting surface of the light projecting portion and the scattered light of the light receiving portion. A measurement system calibrating means for calibrating the measurement system according to the detection output detected by using the particle state detection probe in a state where the light receiving surface and the area including the measurement area are filled with the calibration fresh water or air. An agglutination monitoring device comprising. 6. The measuring system calibrating means corrects the intensity of the laser beam applied to the test water from the light projecting unit and / or the detected intensity of the scattered light received by the light receiving unit. The agglutination monitor device according to item 5.