JP2005030766A - Stuck stain measuring instrument and stuck stain measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stuck stain measuring instrument capable of rapidly measuring the amount of the stain stuck to a piping to obtain an accurate measured value and properly performing the automatic control of water treatment, and a stuck stain measuring method using it. <P>SOLUTION: A light emitting element 2 and a light detecting element 3 are attached to the outer surface of a measuring cell 1 made from a transparent acrylic resin pipe in mutually opposed relationship. A supply pipe 4 is connected to the lower end of the measuring cell 1 and also connected to a white water storage tank through a flow channel changeover four-way valve 5 and a supply pump 6. The flow channel changeover four-way valve 5 is controlled by a control device 9 and made possible not only to supply water into the measuring cell 1 but also to drain the water in the measuring cell 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an attached dirt measuring device and an attached dirt measuring method, and is suitable for use in measuring the amount of attached dirt on piping in an industrial process water system such as a papermaking process or cooling water.
[0002]
[Prior art]
Numerous microorganisms, organic substances, and inorganic substances are floating in the water used for industrial activities such as process water and cooling water, and sticky slime is formed on the pipes and the like due to these floating. In addition, calcium and silicon contained in the water flowing through the pipe adhere to the pipe, resulting in scale. Such adhering dirt on the piping and the like causes various troubles. For example, in a paper mill, when the adhering dirt such as piping is peeled off and floats in white water and adheres to the final product, the quality of the product is significantly deteriorated. Moreover, the adhering contamination of the heat exchanger in the cold water tower causes a decrease in heat exchange efficiency. For this reason, it is necessary to measure the amount of adhering dirt on pipes and the like and to add an appropriate amount of a water treatment agent such as a microbicide, a scale control agent or a cleaning agent according to the measurement result.
[0003]
Conventionally, as an attached dirt measuring device for measuring the amount of attached dirt, a transparent water pipe, a light emitter that irradiates light to the water pipe, and light transmitted from the light emitter to the water pipe are received, An adhesion dirt measuring device provided with a photoreceptor which generates an electric signal according to the intensity of 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 adhering dirt measuring device described in the above publication, the greater the amount of adhering dirt on the water pipe, the smaller the light transmittance, and the weaker the intensity of the light measured, so by grasping the intensity of the light, The amount of adhered dirt can be measured.
[0005]
That is, according to these attached dirt measuring devices, the amount of attached dirt can be directly measured by the change in the intensity of the electric signal. For this reason, it is possible to accurately measure the amount of adhered dirt.
[0006]
Furthermore, since these attached dirt measuring devices can measure the amount of attached dirt quickly, it is possible to cope with a sudden change in the amount of attached dirt.
[0007]
In addition, if the water treatment agent control means for adding an appropriate amount of water treatment agent to water treatment is driven based on the electrical signal generated from the photoreceptor of these adhesion stain measuring devices, the occurrence of adhesion stain is effective. Can be prevented.
[0008]
[Problems to be solved by the invention]
However, in the conventional adhesion dirt measuring device, when the water flowing through the transparent water pipe is water with high turbidity such as white water, or when the water is darkly colored such as waste water in a dyeing factory In such a case, the light emitted from the light emitter is absorbed not only by the dirt adhered to the water pipe, but also by the water flowing through the water pipe. For this reason, there was a problem that the amount of adhered dirt could not be measured accurately, and the addition of the water treatment agent was not properly performed.
[0009]
The present invention has been made in view of the above-mentioned conventional situation, and can measure the amount of attached dirt quickly, the measured value is accurate, and the automatic control of water treatment can be appropriately performed. Providing a measuring device and a method for measuring attached dirt is an issue to be solved.
[0010]
[Means for Solving the Problems]
The adhesion dirt measuring device of the present invention includes a measurement cell capable of transmitting light, a light emitter that irradiates light to the measurement cell, and light that is transmitted from the light emitter to the measurement cell. In the attached dirt measuring device comprising a light receiving body that receives an electric signal and generates an electric signal in accordance with the intensity of the transmitted light, and a measuring unit that measures the intensity of the electric signal, water is contained in the measuring cell. Or a multi-way valve for allowing the water in the measurement cell to drain by stopping the inflow of water into the measurement cell.
[0011]
In the adhered dirt measuring apparatus of the present invention, water to be measured is caused to flow in the dirt measurement cell, and the dirt adhered to the dirt measurement cell with time elapses and becomes an adherent such as scale or slime. When the light emitted from the light emitter passes through the measurement cell, a part of the light is absorbed by the adhered dirt in the measurement cell, and the light intensity is reduced. The light whose intensity is weakened in this way is irradiated onto the photoreceptor, and an electrical signal corresponding to the intensity of the light is generated. By measuring the intensity of the electrical signal at the measuring unit, the amount of attached dirt is quickly measured. be able to. Furthermore, in the adhesion dirt measuring device of the present invention, it is possible to flow water into the measurement cell, or to stop the inflow of water into the measurement cell and drain the water in the measurement cell. Since the multi-way valve for this is provided, light can be irradiated from the light emitter without water in the measurement cell. For this reason, even if the turbidity of the water to be measured is large or colored, the amount of dirt adhering in the measurement cell can be measured without being affected by the turbidity. The amount of dirt can be measured more accurately.
[0012]
Therefore, according to the adhesion dirt measuring device of the present invention, the amount of adhesion dirt on pipes and the like can be measured quickly, the measured value is accurate, and automatic control of water treatment can be appropriately performed.
[0013]
The measurement cell used in the present invention is made of a transparent member capable of passing water, and the light emitter and the light receiver can be provided in close proximity or close to the outside of the measurement cell. If it is like this, since it is not necessary to put a light-emitting body and a light-receiving body in water, a light-emitting body and a light-receiving body can be arrange | positioned easily. 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 technique such as attaching the light emitter and the light receiver at the facing positions, or forming the transparent tube in a donut shape in cross section, and attaching the light emitter and the surface light receiver at the positions facing the inside and the outside.
[0014]
The material of the measurement cell capable of transmitting light 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]
Moreover, when making a measurement cell into a transparent tube, there is no limitation in particular about the cross-sectional shape of a transparent tube, For example, things, such as a rectangle and a circle, are employable. If the cross-sectional shape is rectangular, a planar light-emitting body or light-receiving body can be arranged very close to one side and the other side of the pipe, which is preferable because the sensitivity of the attached dirt measuring device is higher. is there.
[0016]
There is no particular limitation on the light emitter used in the adhesion dirt measuring apparatus of the present invention, but a point light source such as a light bulb, LED, semiconductor laser, or those obtained by guiding them with an optical fiber, or an organic electric field (electroluminescence: EL) light emission. Body, inorganic electric field (electroluminescence: EL) illuminant, assembly in which light emitting diodes are assembled on the same plane to enable light emission on the surface, glass plate or transparent resin plate surface parallel to each other with laser light etc. A surface light source such as one that forms a V-shaped groove to illuminate the fluorescent light from a direction parallel to these plates and reflects the incident light through the groove to enable surface emission. You can also
[0017]
In addition, there is no particular limitation on the photoreceptor used in the adhesion contamination measuring apparatus of the present invention, but to some extent, such as a point photoreceptor that receives light in a small area such as a phototransistor and generates an electrical signal, a photovoltaic cell, CdS, or the like. A surface light receiver that generates an electrical signal by receiving light on a surface having a large area can be employed.
[0018]
In the adhesion dirt measuring device of the present invention, it is preferable that a control device for automatically switching the multi-way valve is provided. In this case, since the multi-way valve can be automatically controlled by the control device, the measurement of the amount of adhered dirt can be automated. In addition, it is also possible to monitor the measurement result of the amount of adhered dirt thus automated at a remote place through the Internet. If this is the case, it becomes possible to remotely monitor and operate the water treatment system using this attached dirt measuring device, and it is possible to prevent troubles in the water treatment system and to operate the water treatment system. The labor cost for can be greatly reduced.
[0019]
In the method for measuring attached dirt according to the present invention, water is allowed to flow inside a measurement cell capable of transmitting light, the light is irradiated to the measurement cell, and the intensity of the light transmitted through the measurement cell is measured. In the attached dirt measurement method for obtaining the attached dirt amount, the measurement of the intensity of the light transmitted through the measurement cell is performed in a state where the inside of the measurement cell is temporarily free of water. To do.
[0020]
In the method for measuring adhered dirt according to the present invention, when measuring the amount of adhered dirt, the inside of the measurement cell is temporarily made free of water, so that the illuminant has no water in the measurement cell. Can be irradiated with light. For this reason, it is possible to measure the amount of dirt adhered to the measurement cell without being affected by the turbidity or coloring of water. For this reason, even if the turbidity of the water to be measured is large or colored, it is possible to measure the amount of adhering dirt on the measurement cell without being affected by it. Can be performed more accurately.
[0021]
There is no particular limitation on the means for temporarily leaving the inside of the measurement cell free of water. For example, after passing water through the measurement cell for a certain period of time, the water supply is stopped and It can be performed by repeating a series of steps of draining water and performing measurement after the water in the measurement cell is drained. In this case, the repetition of water flow and drainage can be easily performed by using, for example, a multi-way valve.
[0022]
What is necessary is just to determine suitably the water flow time in the case of repeating water flow and drainage according to the property of the water which flows into the inside of the cell for a measurement. In addition, drain the water in the measurement cell to make it temporarily free of water, measure the intensity of the light that has passed through the measurement cell, and restart the water flow to the measurement cell. A certain non-water-passing time may be appropriately determined in consideration of the degree of attached dirt amount and the device for measuring the intensity of light. Furthermore, the measurement frequency of the attached dirt may be determined as appropriate depending on the increasing rate of the attached dirt amount, etc., but is usually 1 to 12 times / day. Further, the water flow rate into the measurement cell differs depending on the quality of the water to be passed and the amount of adhered dirt, and cannot be determined uniformly, but is usually in the range of 0.1 to 1.0 m / sec. It is preferable that If the water flow rate is faster than this range, the adhered dirt that has grown to a certain extent is peeled off, and the measurement of the amount of adhered dirt becomes inaccurate. Also, if the water flow rate is lower than this range, a stagnant portion will be generated in the measurement cell, which may promote the generation of scale and slime, or in some cases an anaerobic atmosphere, which is preferable unlike an actual water environment. There may not be.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, Examples 1 and 2 and Comparative Examples 1 and 2 embodying the adhesion dirt measuring device of the present invention will be described with reference to FIGS.
[0024]
(Example 1)
As shown in FIGS. 1 and 2, the attached dirt measuring device of Example 1 is provided with a measuring cell 1 made up of a colorless and transparent acrylic tube, and light is emitted outside the measuring cell 1. A transmitted light linear sensor “Z4LA” (made by OMRON Corporation) composed of the body 2 and the light receiving body 3 is attached. A supply pipe 4 is connected to the lower end of the measurement cell 1, and the supply pipe 4 is connected to a white water storage tank (not shown) via a flow path switching four-way valve 5 and a supply pump 6. The flow path switching four-way valve 5 supplies the water supplied from the supply pump 6 to the measurement cell 1 as shown in FIG. 1, or the water supplied from the supply pump 6 as shown in FIG. Is supplied to the bypass pipe 10 to stop the supply of white water to the measurement cell 1, and the supply pipe 4 is connected to the drain pipe 11 to drain the water in the measurement cell 1. . A drain pipe 7 is connected to the upper end of the measuring cell 1, and the other end of the drain pipe 7 is connected to a drain tank 8. Inside the drainage tank 8, an adhesion test test piece 12 made of SUS304 having a rectangular shape of 3 cm × 5 cm is fixed so as to come into contact with the drainage.
[0025]
The photoreceptor 3 and the flow path switching four-way valve 5 are connected to the control device 9. The control device 9 incorporates a program for controlling the flow path switching four-way valve 5 according to the flowchart shown in FIG. With this program, at the start of control, as shown in FIG. 1, the flow path switching four-way valve 5 is brought into a state of passing white water to the measurement cell 1 (hereinafter referred to as “A state”). When 3540 seconds have elapsed since the start of control, the flow path switching four-way valve 5 is driven, and the white water in the measurement cell 1 is caused to flow into the drainage tank 8 through the drain pipe 11 as shown in FIG. It becomes an empty state (hereinafter referred to as “B state”). Further, after 3598 seconds from the start, the intensity of the electric signal from the photoreceptor 3 is measured by the control device 9, and when 3600 seconds have elapsed, the flow path switching four-way valve 5 is driven again to the A state, and the elapsed time returns to zero. It is. Thus, the flow path switching four-way valve 5 is controlled by the control device 9 so that the A state and the B state are repeated.
[0026]
<Adhesion dirt measurement test>
Using the adhered dirt measuring apparatus of Example 1 configured as described above, white water (pH = 6.7, Poip integral sphere turbidity 50 ppm, 35 ° C.) by the supply pump 6 shown in FIGS. Was supplied at a flow rate of 2 L / min, and an adhesion dirt measurement test was conducted.
[0027]
(Comparative Example 1)
In Comparative Example 1, the same adhesion dirt measuring device as that in Example 1 was used. However, in the adhesion dirt measurement test, the flow path switching four-way valve 5 remains in the B state (the state shown in FIG. 2), and the intensity of the electrical signal from the photoreceptor 3 is measured while the measurement cell 1 is filled with white water. Measurement was performed by the control device 9.
[0028]
<Evaluation>
In Example 1, as shown in FIG. 4, the amount of dirt on the test piece 12 for adhesion test increases with time, whereas the electric signal intensity from the photoreceptor 3 decreases with time. It was found that the amount of dirt and the electric signal intensity showed a good correlation. From this, it was found that the amount of adhered dirt can be measured quickly even with white water that is difficult to transmit light, and the measured value is accurate.
[0029]
On the other hand, in Comparative Example 1, as shown in FIG. 5, the intensity of the electric signal from the photoreceptor 3 does not change much even though the amount of adhered dirt of the adhesion test test piece 12 increases with time. It was impossible to measure the amount of adhered dirt. The reason is that in Comparative Example 1, the amount of adhering dirt was measured in a state in which white water was put in the measurement cell 1, so that it was considered that the result was strongly influenced by the decrease in transmittance due to the turbidity of white water. It is done.
[0030]
(Example 2)
In Example 2, the attached dirt measuring device used in Example 1 was applied to a white water treatment system in an actual neutral papermaking factory. As shown in FIG. 6, the neutral paper mill is equipped with a paper machine 14 for paper making. White paper flowing down below the paper machine 14 (the amount of white water retained in the paper making process is 450 tons, temperature). There is a white water pit 15 under the wire for collecting the whip integral sphere turbidity of 200 ppm or more, which cannot be measured because fine fibers are present in white water at 45 ° C, pH 7.1. A white water discharge pipe 16 for discharging the collected white water is connected to the wire white water pit 15, and the other end of the white water discharge pipe 16 is connected to a white water silo 17 for storing white water. White water in the white water silo 17 is supplied to the mixing chest 22, the machine chest 23, and the seed box 24 from the white water supply pipe 17a.
[0031]
A bypass pipe 18 is branched and connected in the middle of the white water discharge pipe 16, and the other end of the bypass pipe 18 is connected to the supply pump 6 of the attached dirt measuring device 30. A chemical liquid supply pipe 19 is branched and connected to the white water discharge pipe 16 at a position closer to the white water silo 17 than a branch point of the bypass pipe 18. The other end of the chemical liquid supply pipe 19 is connected to the chemical liquid via the chemical injection pump 20. It is connected to the tank 21. The chemical tank 21 stores a 20 wt% aqueous slurry of bromochlorodimethylhydantoin. The chemical injection pump 20 is connected to the control device 9 and is controlled by the value (α) of the light transmittance (L _n ) / light transmittance (L ₀ ) at the beginning of operation of the _nth measurement. That is, if α is 0.9 or more, the drug injection pump 20 is driven every 30 minutes for 30 minutes, and if α is 0.85 or more and less than 0.9, the drug injection pump 20 is 30 every 6 hours. If the α is less than 0.85, a program is incorporated in the control device 9 such that the medicine pump 20 is driven for 30 minutes every 4 hours. In addition, 24 kg of bromochlorodimethylhydantoin is supplied by driving the chemical injection pump 20 for 30 minutes.
[0032]
Using the water treatment system configured as described above, an adhesion dirt measurement test was performed under the same conditions as in Example 1.
[0033]
(Comparative Example 2)
In Comparative Example 2, the dosing pump 20 was always driven for 30 minutes every 8 hours without using the attached dirt measuring device. Other conditions are the same as in the second embodiment.
[0034]
<Evaluation>
In Example 2, as shown in FIG. 7, the α value decreased around the 4th day and around the 19th to 20th days from the start of operation of the water treatment system. And based on the fall of the (alpha) value, the drive frequency of the chemical injection pump 20 increased, and (alpha) value rose after that. As a result, the water treatment system could be operated for 25 days without any trouble, and during that time, the neutral paper produced in the papermaking factory did not have any spots causing quality problems.
[0035]
On the other hand, in Comparative Example 2, as shown in FIG. 8, the α value continued to decrease with the passage of time from the start of operation of the water treatment system. On the 16th day from the start of operation, the neutral paper produced at the papermaking factory had spots causing quality problems, which forced the operation to stop. For this reason, the paper machine 14 (see FIG. 6) was subjected to alkali cleaning.
[0036]
From the above, according to this water treatment apparatus, automatic control of water treatment could be appropriately performed, and stable operation and cost saving could be achieved.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a water supply state (A state) to a measurement cell in Example 1. FIG.
FIG. 2 is a schematic diagram showing a drainage state (B state) from a measurement cell in Example 1. FIG.
FIG. 3 is a flowchart of control of the flow path switching four-way valve 5;
FIG. 4 is a graph showing a temporal change in the amount of adhered dirt and a temporal change in electric signal intensity from the photoreceptor in Example 1.
FIG. 5 is a graph showing a temporal change in the amount of adhered dirt and a temporal change in electric signal intensity from the photoreceptor in Comparative Example 1;
6 is a schematic diagram of a water treatment system used in Example 2. FIG.
7 is a graph showing the change over time in the number of additions of the aqueous bromochlorodimethylhydantoin slurry and the change over time in the α value in Example 2. FIG.
8 is a graph showing the change over time in the number of additions of the aqueous bromochlorodimethylhydantoin slurry and the change over time in the α value in Comparative Example 2. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Measurement cell 2 ... Luminescent body 3 ... Photoreceptor 10, 11 ... Bypass part (10 ... Bypass pipe, 11 ... Drain pipe)
7 ... Drain pipe 5 ... Multi-way valve (Flow path switching four-way valve)
9 ... Measurement unit (control device)

Claims (3)

A measurement cell capable of transmitting light; a light emitter that irradiates light to the measurement cell; and a light that is transmitted from the light emitter to the measurement cell. In an attached dirt measuring device comprising a photoreceptor that generates an electrical signal corresponding to the strength, and a measuring unit that measures the strength of the electrical signal,
A multi-way valve is provided to allow water to flow into the measurement cell or to stop the inflow of water into the measurement cell and drain the water in the measurement cell. An adhesion dirt measuring device characterized by comprising: 2. The adhesion dirt measuring device according to claim 1, further comprising a control device for automatically switching the multi-way valve. Adhesion to determine the amount of adhered dirt by flowing water into a measurement cell capable of transmitting light, irradiating the measurement cell with light, and measuring the intensity of the light transmitted through the measurement cell In the dirt measurement method,
The method for measuring adhered dirt, wherein the measurement of the intensity of light transmitted through the measurement cell is performed with the inside of the measurement cell temporarily in the absence of water.

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