JP4330930B2 - Dirt measuring device and water treatment method using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dirt measuring device and a water treatment method using the same. This dirt measuring apparatus and water treatment method are suitable for use in dirt measurement and water treatment in industrial process water systems such as papermaking and cooling water.
[0002]
[Prior art]
Water used in industrial activities, such as process water and cooling water, contains calcium and silicon, and as a result, scale deposits in pipes and heat exchangers. Become. In addition, a high-viscosity mass called slime produced by microorganisms present in water may adhere to the piping or the like. Dirt adhering to such piping will cause various troubles. For example, when the dirt on the piping in the papermaking process is peeled off and attached to the product, the quality of the product is significantly lowered. Further, in the cold water tower, if dirt in the cooling water adheres to the heat exchanger, the heat exchange efficiency is lowered. For this reason, it is necessary to measure the dirt adhering to the piping or the like, and to add an appropriate amount of a chemical such as a bactericide or a dispersant according to the measurement result.
[0003]
Conventionally, as a dirt measuring device for measuring the amount of dirt attached to such pipes and the like, a transparent water pipe, a light emitter that irradiates light to the water pipe, and a light pipe that irradiates and passes through the water pipe. A dirt measuring device including a light receiving body that receives light and generates an electrical signal corresponding to the intensity of the light is known (for example, Patent Documents 1 to 3).
[Patent Document 1]
JP-A-5-209725 [Patent Document 2]
Japanese Patent Laid-Open No. 9-236546 [Patent Document 3]
Japanese Patent Laid-Open No. 10-267843
In the dirt measuring device described in the above publication, since the light transmittance decreases as the water pipe becomes dirty and the intensity of the light to be measured decreases, the dirt can be detected by grasping the degree of the decrease in the intensity. Can be measured.
[0005]
That is, according to these dirt measuring devices, dirt can be directly measured by the change in the intensity of the electric signal. For this reason, the degree of contamination can be accurately measured to some extent.
[0006]
Furthermore, since these dirt measuring devices can measure the degree of dirt quickly and continuously, it is possible to cope with sudden changes in dirt.
[0007]
Moreover, if the water treatment agent control means for adding an appropriate amount of water treatment agent to the water treatment is driven based on the electrical signal generated from the light receiving part of these dirt measuring devices, the occurrence of dirt is effectively prevented. can do.
[0008]
[Problems to be solved by the invention]
However, since the conventional dirt measuring device uses a small light source such as a light bulb, an LED, a semiconductor laser, or a light guide of them, the light is irradiated only to a very narrow range of the water pipe. For this reason, the entire dirt is estimated only from the measurement result in the narrow range, and the measurement value is likely to vary, and the dirt measurement is likely to be inaccurate.
[0009]
The present invention has been made in view of the above-described conventional situation, and is a dirt measuring device capable of measuring the degree of dirt in an aqueous system quickly and continuously, with small variations in measurement values, and capable of accurate measurement. And providing a water treatment method using the same is a problem to be solved.
[0010]
[Means for Solving the Problems]
The dirt measuring device of the present invention includes a dirt measuring cell capable of transmitting light, a light emitter for irradiating the dirt measuring cell with light, and the light emitting body being irradiated to the measuring cell. In the dirt measuring apparatus, comprising: a light receiving body that receives transmitted light and generates an electrical signal corresponding to the intensity of the transmitted light; and a measurement unit that measures the intensity of the electrical signal. The light receiving body is a surface light receiving body that generates the electrical signal by receiving light on a surface.
[0011]
In the dirt measuring apparatus of the present invention, since the intensity change of the electric signal generated from the photoreceptor is continuously measured by the measuring unit, the degree of dirt can be measured quickly and continuously. In addition, since the light emitter is a surface light emitter capable of emitting light in a wide range of a surface, the dirt measuring cell is wider than a conventional dirt measuring device that emits light from a point light source. Light is irradiated. Further, since the light receiving body is a surface light receiving body that receives light in a wide range called a surface, the light transmitted through the wide range of the dirt measurement cell is received in a wide range and an electric signal is generated. For this reason, the measured value of dirt by this measuring device is an averaged value based on the light that is irradiated and transmitted over a wide range of the dirt measuring cell.
[0012]
Therefore, when the dirt is measured in the water system by the dirt measuring device of the present invention, the degree of dirt can be measured quickly and continuously, and the measurement value variation is small and accurate measurement is possible.
[0013]
The dirt measurement cell is made of a transparent member that can pass water, and the surface light emitter and the surface light receiver can be provided in close proximity or close to the outside of the dirt measurement cell. In this case, it is not necessary to put the surface light emitter and the surface light receiver in water, and therefore the surface light emitter and the surface light receiver can be easily arranged. As an example of this, for example, a part of the water system pipe to be measured is a transparent pipe, or a bypass pipe is provided in the pipe and the bypass pipe is made a transparent pipe. It is possible to use a method such as attaching a surface light emitter and a surface light receiver at a facing position, or forming a transparent tube with a cross-sectional donut shape, and affixing the surface light emitter and the surface light receiver at the positions where the surface light emitter and the surface light receiver face each other. it can.
[0014]
The material of the transparent member that can pass water is not particularly limited, and inorganic glass, acrylic resin, transparent vinyl chloride resin, polystyrene, polyethylene terephthalate, fluorine resin, or the like can be used. Since the fluororesin has excellent chemical resistance, it is suitable for use in an environment such as a strong acid or strong alkali.
[0015]
When the transparent member is a transparent tube, there is no particular limitation on the cross-sectional shape of the transparent tube, and for example, a rectangular or circular shape can be adopted. If the cross-sectional shape is rectangular, a planar light-emitting body or light-receiving body can be disposed very close to one side and the other side of the piping, which is preferable because the sensitivity of the dirt measuring device becomes higher. .
[0016]
As a surface light emitter that emits light from the entire surface, for example, an organic electric field (electroluminescence: EL) light emitter, an inorganic electric field (electroluminescence: EL) light emitter, and light emitting diodes can be assembled on the same plane to emit light on the surface. And the like. Further, grooves having a V-shaped cross section parallel to each other by a laser beam or the like are formed on the surface of the glass plate or the transparent resin plate, the light from the fluorescent lamp is irradiated from the direction parallel to these plates, and the incident light is irradiated to the groove It is also possible to use a material that is capable of surface emission by reflecting the light. Among these, an organic electric field (electroluminescence: EL) illuminant is thin and flexible, and can be used after being cut into a free size.
[0017]
The area of the light emitting surface of the surface light emitters is preferably in the range of 100mm ² ~100000mm ^2. If the area of the light emitting surface is less than 100 mm ² , the variation in measured values increases, making accurate measurement difficult. In addition, when the area of the light emitting surface exceeds 100,000 mm ² , the variation in the measurement value becomes small and accurate measurement can be performed, but the measurement cell becomes large and the manufacturing cost increases, and it is difficult to secure the installation location. Become. More preferably in the range of 150mm ² ~20000mm ^2.
[0018]
The luminance of the surface light emitter is preferably in the range of 50 mCd to 10000 mCd. If it is less than 50 mCd, the intensity of the signal emitted from the photoreceptor becomes weak and the measurement error increases. In addition, the surface light emitters exceeding 10,000 mCd are expensive, and the dirt measuring device is expensive.
[0019]
As the surface light receiver, any surface light receiver may be employed as long as it receives an electric signal by receiving light on a surface having a certain area. For example, a photocell, a photoreceptor using CdS, and the like can be given. A photovoltaic cell having a large light-receiving surface is commercially available at a low price. Although the area of the light receiving surface of the surface light-receiving body is appropriately determined, it is preferably in the range of 150mm ² ~100000mm ^2. If the area of the light receiving surface is less than 150 mm 2, the variation in the measured value becomes large, and accurate measurement becomes difficult. In addition, when the area of the light emitting surface exceeds 100,000 mm ² , the variation in the measurement value becomes small and accurate measurement can be performed, but the measurement cell becomes large and the manufacturing cost increases, and it is difficult to secure the installation location. Become. And more preferably in the range of 200mm ² ~20000mm ^2.
[0020]
Further, the ratio of the area of the light emitting surface of the surface light emitter to the area of the light receiving surface of the surface light receiver is not particularly limited, and may be appropriately determined according to the shape of the measurement cell. Furthermore, the distance between the surface light emitter and the surface light receiver can be determined as appropriate according to the turbidity of water flowing through the measurement cell, the required sensitivity, and the like.
[0021]
The water treatment method of the present invention is to measure water-based soil using the soil measuring device according to claim 1, and add a water treatment agent in an amount suitable for water treatment to the water based on the measurement result of the soil measuring device. Features.
[0022]
In the water treatment method of the present invention, an amount of water treatment agent suitable for water treatment is added to the water system based on the result of measuring the water system dirt by the dirt measuring apparatus according to claim 1. Specifically, for example, a water treatment agent is added by a combination of a chemical injection pump and its control device. For this reason, generation | occurrence | production of dirt can be prevented effectively. Examples of the water treatment agent include a microbicide for preventing slime generation, a corrosion inhibitor, a scale control agent, an antifoaming agent, and an antifouling agent.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, Example 1 and Comparative Example 1 that embody a dirt measuring device and a dirt measuring method of the present invention will be described with reference to FIGS.
[0024]
Example 1
As shown in FIG. 1, the dirt measuring apparatus of Example 1 includes a measurement cell 1 made of a colorless and transparent acrylic plate and having a container shape with a height of 20 cm, a width of 20 cm, and a depth of 10 cm. A partition plate 1d is suspended inside the measurement cell 1, and the capacity is divided into 1: 2. A total of eight adhesion test test pieces 4 made of SUS304 and having a rectangular shape of 3 cm × 5 cm are attached to the partition plate 1 d in two rows of four in parallel with the side walls 1 b and 1 c. A water supply pipe 1e having an inner diameter of 3 cm and a drain pipe 1f having an inner diameter of 3 cm are connected to the bottom plate 1a, one on each side of the partition plate 1d. As shown in FIG. 2, the water supply pipe 1 e is connected to the storage tank 6 via the circulation pump 5, and the drain pipe 1 f is connected to the storage tank 6. A white EL light emitter 2 (8 cm × 8 cm) of 5 mCd / cm ² is attached to the outer surface of the side wall 1b of the measuring cell 1. A photovoltaic cell 3 (5 cm × 7 cm, manufactured by SANYO Co., Ltd.) is attached to the outer surface of the side wall 1 c of the measuring cell 1 at a position facing the white EL light emitter 2. The photovoltaic cell 3 is connected to the voltmeter 20 through a lead wire.
[0025]
(Stain measurement test)
A dirt measurement test was performed using the dirt measuring apparatus of Example 1 configured as described above. That is, 1000 L of papermaking white water (pH = 6.7, Poip integrating sphere turbidity 50 ppm) is placed in the storage tank 6 shown in FIG. 2 and maintained at 35 ° C. by a temperature controller (not shown). Then, white paper water was pumped from the position near the bottom of the storage tank 6 by the circulation pump 5 and circulated at a flow rate of 2 L / min. Papermaking white water pumped up from the storage tank 6 passes from the circulation pump 5 through the water supply pipe 1e, enters the measurement cell 1, and comes into contact with the adhesion test test piece 4 so that the surface of the adhesion test test piece 4 is gradually contaminated. Adhere to. Then, it overflows the partition plate 1d and is stored in the storage tank 6 through the drain pipe 1f. Further, the white paper water stored in the storage tank 6 is circulated again by the circulation pump 5. In addition, in order to prevent the death of microorganisms during the test, 100 ml of a mixed solution containing 1000 ppm of yeast extract and 200 ppm of glucose was added every 12 hours. The results are shown in FIGS.
[0026]
As can be seen from FIG. 3, the increase in the amount of deposits on the test piece 4 for the soiled cloth adhesion test increased with the passage of time. On the other hand, the electromotive force of the photovoltaic panel 3 decreased with time. When the increase in the amount of deposits on the test piece 4 for dirt adhesion test was compared with the voltage drop of the electromotive force of the photovoltaic cell 3, it was found that a good correlation was shown as shown in FIG.
[0027]
(Comparative Example 1)
As shown in FIG. 5, in the dirt measuring apparatus of Comparative Example 1, the LED 7 as a light emitter is provided close to the outside of the side wall 1b, the phototransistor 8 as a light receiver faces the LED 7, and the side wall 1c. It is provided in the position outside. The diameter of the light emitting surface of the LED 7 is 3 mm (area = 7.1 mm ² ), and the diameter of the light receiving surface of the phototransistor 8 is 4 mm (area = 12.6 mm ² ). Other configurations are the same as those of the dirt measuring apparatus according to the first embodiment shown in FIG. 1, and the same components are denoted by the same reference numerals and detailed description thereof is omitted.
[0028]
Using the stain measuring apparatus of Comparative Example 1 configured as described above, stain measurement was performed under the same conditions as in Example 1. The results are shown in FIG.
[0029]
As can be seen from FIG. 6, the increase in the amount of deposits on the dirt adhesion test test piece 4 increases with time, whereas the output voltage of the phototransistor 8 fluctuates greatly. There was no correlation with the increased amount of deposits. The cause is considered as follows. That is, in this dirt measuring device, since the LED 7 which is a small light source having a diameter of 3 mm (area = 7.1 mm ² ) is used as the light emitter, the light emitted from the LED 7 only hits a very narrow range of the measuring cell 1. Absent. Further, since the small phototransistor 8 having a diameter of 4 mm (area = 12.6 mm ² ) is used as the photoreceptor, the dirt is measured in a very narrow range of the measuring cell 1. Then, when the dirt particles happen to adhere to this narrow range or the attached dirt particles peel off, the output voltage of the phototransistor 8 greatly fluctuates. For this reason, it is considered that the measurement values vary and it is difficult to measure dirt.
[0030]
(Example 2)
In Example 2, the dirt measuring apparatus used in Example 1 was applied to an actual water treatment system. That is, in this water treatment system, as shown in FIG. 7, a chemical tank 10 for storing a sodium hypochlorite solution (effective chlorine concentration 1.2%) is installed in the vicinity of the storage tank 6, and a chemical injection pump 11, the sodium hypochlorite solution can be added to the storage tank 6. The medicinal pump 11 is connected to the control device 12, and the control device 12 drives the medicinal pump 11 when the electromotive force of the photovoltaic panel 3 is below a certain threshold value, and puts the sodium hypochlorite solution into the storage tank 6. When the residual chlorine concentration becomes 0.3 mgCl / L (measured by JIS K0101 DPD colorimetric method) or more, the chemical injection pump 11 is stopped.
[0031]
Using the water treatment system configured as described above, papermaking white water was placed in the storage tank 6 and a soil measurement test was performed under the same conditions as in Example 1. The results are shown in FIG.
[0032]
As can be seen from FIG. 8, the increase in the amount of deposits on the soil adhesion test test piece 4 hardly increased over time, and it was found that contamination could be prevented. Moreover, the electromotive force of the photovoltaic cell 3 hardly changed, and had a correlation with the increase in the amount of deposits on the dirt adhesion test test piece 4. From these things, it turns out that according to this water treatment device, the occurrence of dirt can be prevented by feeding back the degree of dirt and controlling the medicine pump 5.
[0033]
(Example 3)
In Example 3, the dirt measuring device was applied to a water treatment system for open circulating cooling water (retained water amount: about 200 L) of a small chilled water tower. As shown in FIG. 9, the circuit for the open circulation type cooling water of this small chilled water tower passes through the heat exchanger 22 from the circulating water storage pit 20 a provided in the small chilled water tower 20 through the circulation pump 21 and is small. It is formed by a circuit that flows down between the water spray plates 20b of the cold water tower 20 and returns to the circulating water storage pit 20a again. A bypass pipe 23 is branched and connected in the middle of the pipe from the heat exchanger 22 to the small chilled water tower 20, and the other end of the bypass pipe 23 is connected to the circulating water storage pit 20a. A dirt measuring device 13 is provided in the middle of the bypass pipe 23.
[0034]
In the dirt measuring device 13, the area of the light emitting surface of the white EL light emitter is 150 mm ² , and the area of the light receiving surface of the photovoltaic cell 3 is 150 mm ² . Other configurations are the same as those of the dirt measuring apparatus according to the first embodiment shown in FIG. 1, and the same components are denoted by the same reference numerals and detailed description thereof is omitted.
[0035]
A chemical tank 19 for storing a cleaning agent (hydrazine 20%, sodium polyacrylate (molecular weight 10000) 5%, water 75%) is installed in the vicinity of the circulating water storage pit 20a. Thus, a cleaning agent can be added to the circulating water storage pit 20a. The medicinal pump 30 is connected to the control device 24. The control device 24 repeats the driving of the medicinal pump 30 for 10 minutes and the stop for 50 minutes when the electromotive force of the photovoltaic cell 3 becomes 110 mV or less. While the chemical injection pump 30 is operating, the cleaning agent is added in an amount of 3 ppm with respect to the circulating water per minute. And when the electromotive force of the photovoltaic cell 3 exceeds 110 mV again, it sets so that the drive of the chemical injection pump 30 may be stopped by the control apparatus 24. FIG.
[0036]
Using the water treatment system configured as described above, Yokkaichi Industrial Water was used as circulating water, and continuous operation was performed at a water temperature of 26 ° C. for 7 days (168 hours). As a result, as shown in FIG. 10, the electromotive force became 110 mV or less after about 40 hours from the start of operation, and the cleaning agent was added. Thereafter, due to the death and reduction of microorganisms, the soil disappeared and the electromotive force increased. When the circulation was further continued, dirt gradually adhered again, the electromotive force decreased again, and about 140 hours after the start of the circulation, a second cleaning agent was added. As a result, it was found that the electromotive force increased again and the dirt was removed. From the above, it was found that by using the dirt measuring device 13 of Example 3 and adding the cleaning agent while controlling it by the control device 24, it is possible to manage the water system continuously.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of a part of a dirt measuring apparatus according to a first embodiment.
FIG. 2 is a schematic perspective view of the dirt measuring apparatus according to the first embodiment.
3 is a graph showing a change with time of an increase in the amount of deposits on the dirt adhesion test test piece and a change with time of the electromotive force of the photovoltaic cell in Example 1. FIG.
4 is a graph showing the relationship between the increase in the amount of deposits on the dirt adhesion test test piece and the electromotive force of the photovoltaic panel in Example 1. FIG.
5 is a schematic perspective view of a part of the dirt measurement device of Comparative Example 1. FIG.
6 is a graph showing a change with time of an increase in the amount of deposits on a dirt adhesion test test piece and a change with time of an electromotive force of a phototransistor in Comparative Example 1;
FIG. 7 is a schematic diagram of a water treatment apparatus of Example 2.
8 is a graph showing a change with time of an increase in the amount of deposits on a dirt adhesion test test piece and a change with time of an electromotive force of a photovoltaic cell in Example 2. FIG.
FIG. 9 is a schematic diagram of a water treatment system according to a third embodiment.
10 is a graph showing a change with time of electromotive force of the photovoltaic cell in Example 3. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Cell 2 for dirt measurement, 7 ... Light emitter (2 ... White EL light emitter, 7 ... LED)
3, 8 ... Photoreceptor (3 ... Photocell, 8 ... Phototransistor)

Claims (5)

A dirt measuring cell capable of transmitting light; a light emitter for irradiating the dirt measuring cell with light; and receiving light transmitted through the measuring cell from the light emitter, In a dirt measuring apparatus comprising a photoreceptor that generates an electrical signal corresponding to the intensity of transmitted light, and a measuring unit that measures the intensity of the electrical signal,
The emitters What surface emitter der emitting at the surface, the area of the light-emitting surface is 150mm ² ~20000mm ^2, faces the photoreceptor der which the electrical signal is generated by said light receiving body for receiving a plane What, dirt measuring apparatus, wherein the area of the light receiving surface is 150mm ² ~100000mm ^2.   2. The dirt according to claim 1, wherein the dirt measuring cell is made of a transparent member capable of passing water, and the surface light emitter and the surface light receiving body are provided in close proximity or close to the outside of the dirt measuring cell. measuring device.   3. The dirt measuring apparatus according to claim 1, wherein the surface light emitter is an electroluminescent body.   4. The dirt measuring device according to claim 1, wherein the surface light receiver is a photocell.   A water treatment method comprising: measuring water-based soil using the soil measuring device according to claim 1; and adding an amount of a water treatment agent suitable for water treatment to the water based on a measurement result of the soil measuring device.

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