JPH10253542A - Method for evaluating adhesion of scale in piping - Google Patents

Abstract

PROBLEM TO BE SOLVED: To evaluate the adhesion state of scales and also, to evaluate the adhesion state of scales for every composition of compound in piping. SOLUTION: Particles in a liquid in a piping 2 is measured on the downstream side from a scale adhesion preventing means 3. The effectiveness of scale adhesion prevention is estimated on the basis of the measured results to perform evaluation. The equivalent amount of concentration of particles in flowing water in the piping 2 is measured, and the state of adhesion of scales in the piping 2 is evaluated from the equivalent amount of concentration. In addition, light is brought to strike particles in the flowing water in the piping 2 and absorbed by the particles, and the absorption intensity is measured from transmitted light or reflected light obtained by the absorption of light. The measured absorption intensity is assumed to be the equivalent amount of concentration of the particles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scale adhering to a pipe, and more particularly to a method for estimating and evaluating the state of adhering of a scale and evaluating a scale adhering preventing means.

[0002]

2. Description of the Related Art Tap water and various liquids flow in water pipes and pipes installed in plants. The liquid flowing through the pipe contains compounds of various components in a dissolved state or a fine particle state. The compound that dissolves in the liquid becomes a scale when deposited on the inner wall surface of the pipe. When the amount of deposition of the scale increases, the inside diameter of the pipe is reduced, and the flow rate and the flow rate of the liquid flowing in the pipe are reduced, possibly affecting the treatment of the plant. If the substance floating in the pipe is a particle having a diameter larger than that of the fine particles, the substance may adhere to the bottom of the pipe depending on the flow rate and the flow velocity.

Conventionally, various methods such as a mechanical method, an electrical method, and an electrochemical method have been known as methods for preventing scale from adhering to piping. In these scale adhesion prevention treatments, the compound in a dissolved state is made into fine particles in the pipe to prevent the scale from adhering to the inner wall of the pipe, or to remove particles having a larger diameter than the fine particles in the pipe. By doing so, adhesion of scale is prevented.

[0004]

In order to evaluate the effect of the scale adhesion preventing treatment, processing conditions are set in each scale adhesion prevention treatment, and after the adhesion prevention treatment is performed under the set conditions for several weeks or months, the piping is connected. It can be performed by disassembling and inspecting the attached state of the scale attached in the pipe. However, in order to disassemble the pipes, it is necessary to stop the apparatus in which the pipes are installed, and there is a problem that the connection work of the pipes has an effect on plant processing and that it takes time to disassemble and assemble the pipes.

Further, in order to set the conditions of the scale adhesion preventing treatment to the optimum conditions based on the evaluation results, it is necessary to repeat the above-mentioned condition setting and evaluation. It is not realistic to control the scale adhesion preventing process under the optimum condition in consideration of the work required for the evaluation and the process time until the optimum condition is obtained, and it is difficult to actually perform the process. For this reason, in the conventional scale adhesion prevention processing, it is not possible to set conditions based on effective evaluation, and the conditions are set by trial and error or empirical rules.

It is conceivable to insert a measuring probe into the pipe to check the adhesion of the scale in the pipe. However, it is difficult to dispose the measuring probe in the pipe without affecting the flow of the liquid. It is difficult, and there is also a problem that only the installation location of the device probe can be evaluated.

[0007] In addition, various components are usually contained in flowing water such as purified water, drainage water, or liquid in the manufacturing process, and the conditions for optimally performing the scale adhesion preventing treatment are also defined. It may vary depending on the composition. In addition, conditions for optimally performing the scale adhesion prevention process may differ depending on flow conditions such as temperature, flow velocity, and flow rate of flowing water.

[0008] In the conventional scale adhesion preventing treatment, a rapid evaluation of the adhesion prevention cannot be obtained. Therefore, even if the composition components, the flow conditions such as the temperature, the flow rate, and the flow rate change, the processing conditions are changed. It is performed under constant processing conditions. Therefore, in the conventional scale adhesion prevention processing, it is not possible to control the processing according to the flow of the fluid in the pipe,
Processing is not always performed under optimal conditions.

Therefore, the present invention solves the problems of the above-mentioned conventional method for evaluating the scale adhesion preventing treatment, enables quick evaluation of the scale adhesion state, and can be applied to the setting of scale adhesion preventing treatment conditions. It is a first object to provide a method for evaluating the adhesion of scale in a pipe, and
It is a second object of the present invention to provide a method for evaluating the adhesion of scale in a pipe, which can evaluate the state of adhesion of the scale for each composition of the compound in the pipe.

[0010]

According to the method for evaluating the adhesion of scale in a pipe according to the present invention, a substance contained in a fluid flowing in the pipe is optically measured, and a concentration equivalent of the measured substance is determined by this measurement. The state of adhesion of the scale in the pipe is estimated from the equivalent amount of the concentration, and the state of adhesion and the treatment for preventing adhesion are evaluated.

In the adhesion evaluation method of the present invention, the substance to be measured in the fluid in the pipe is fine particles and particles having a diameter larger than the fine particles. In the case where the chemical substance in a dissolved state is converted into fine particles to prevent the adhesion of the scale, the fine particles are measured to obtain an equivalent amount of the concentration. Can be evaluated as having a high effect. In addition, when performing scale adhesion evaluation by removing particles in the pipe, the particles are measured to determine the concentration equivalent amount, and the smaller the concentration equivalent amount of the particles, the smaller the degree of adhesion, the smaller the degree of adhesion, and the lower the adhesion prevention amount. It can be evaluated that the effect is high.

The first method for evaluating scale adhesion in a pipe according to the present invention measures fine particles in a liquid in a pipe downstream of scale adhesion preventing means, and based on the measurement result, the effect of scale adhesion prevention. This is a method of estimating and evaluating the concentration of fine particles in the flowing water in the pipe, and evaluating the adhesion state of the scale in the pipe from the concentration. In addition, the concentration equivalent of the fine particles is determined by measuring the absorption intensity from transmitted light or reflected light obtained by absorbing light by injecting light into the fine particles in flowing water in the pipe, and measuring the absorption intensity by the concentration equivalent of the concentration of the fine particles. And

According to the first method for evaluating the adhesion of scale in a pipe, the concentration of the fine particles in the liquid is measured by measuring the fine particles in the liquid in the pipe by the fine particle measuring means provided downstream of the means for preventing adhesion of scale. Measure the corresponding amount. The amount equivalent to the concentration of the fine particles in the liquid corresponds to the amount of the substance deposited in the dissolved state by the scale adhesion preventing means. When this concentration is large, the dissolved state that easily causes scale adhesion is small, indicating that there are many fine particle states that are unlikely to cause scale adhesion, indicating that the effect of preventing scale adhesion by the scale adhesion prevention means is high. Is shown. In addition, when the concentration equivalent amount is small, the dissolved state that easily causes scale adhesion is large, and the fine particle state that is unlikely to cause scale adhesion is small, indicating that the effect of preventing scale adhesion by the scale adhesion preventing means is low. It is shown that.

The concentration equivalent of the fine particles is determined by measuring the absorption intensity from transmitted light or reflected light obtained by irradiating light in the infrared region onto fine particles floating in flowing water in a pipe and absorbing the fine particles. The absorption intensity can be set to an amount equivalent to the concentration of the fine particles, and the absorption intensity makes it possible to evaluate the state of the scale adhesion by the scale adhesion preventing means and set the optimum conditions.

The fine particle concentration equivalent amount measuring means measures the absorption intensity for each wavelength in the measurement using light in the infrared region. According to this, the absorption intensity for each wavelength is measured for each composition of the fine particles. And the adhesion evaluation for each composition of the scale in the pipe can be performed.

This scale adhesion evaluation method utilizes the fact that the infrared spectrum is different depending on the composition of the fine particles. When the fine particles in the liquid are irradiated with light in the infrared region, the irradiated infrared region light Has absorption characteristics at characteristic different wavelengths, and utilizes the characteristic that the absorption intensity depends on the concentration of the fine particles. The value is measured.

Therefore, according to this scale adhesion evaluation method, the composition of the fine particles can be known from the characteristic absorption wavelength of the infrared spectrum, and the concentration of the fine particles can be determined from the absorption intensity at the characteristic wavelength of the fine particles. Can be requested.

In the measurement of absorption intensity, the concentration of fine particles in flowing water can be determined from the measured absorption intensity by using the relationship between the concentration of fine particles of a known composition and the absorption intensity of infrared region light.

In the second method of the present invention for evaluating the adhesion of scale in a pipe, particles which are deposited in the pipe and cause scale are measured downstream of the means for preventing scale adhesion, and based on the measurement results, This is a method of estimating and evaluating the effect of preventing the adhesion of scale, in which the equivalent amount of particles in flowing water in a pipe is measured, and the adhesion state of the scale in the pipe is evaluated from the equivalent amount of the concentration. In addition, the concentration equivalent of particles is measured by measuring the turbidity by irradiating light to fine particles in flowing water in a pipe, and this turbidity is regarded as the concentration equivalent of particles.

According to the second method for evaluating the adhesion of scale in a pipe, the particles in the liquid in the pipe are measured by the particle measuring means provided on the downstream side of the means for preventing adhesion of scale, and the concentration of the particles in the liquid is measured. Measure the corresponding amount. This measured amount is equivalent to the concentration of the particles after the particles have been removed by the scale adhesion preventing means. If this concentration equivalent amount is small, it indicates that the removal of the particles in the scale adhesion preventing means is sufficiently performed, and that the residual particles in the pipe are small,
This shows that the scale adhesion preventing means has a high effect of preventing the adhesion of scale. Further, when this concentration equivalent amount is large, it indicates that the removal of particles by the scale adhesion preventing means is insufficient, and that many particles remain in the pipe, and the scale by the scale adhesion prevention means This shows that the effect of preventing the adhesion of is low.

The turbidity of the particles is measured by measuring the absorbance or the scattering intensity by irradiating light to the particles floating in the flowing water in the pipe, and measuring the turbidity of the particles. The turbidity makes it possible to evaluate the state of scale adhesion by the scale adhesion preventing means and to set optimal conditions.

[0022]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic block diagram for explaining the method for evaluating the adhesion of scale in a pipe according to the present invention. In FIG. 1, a scale adhesion preventing means 3 is a device for preventing scale from adhering in the pipe 2, and deposits a compound dissolved in a liquid into fine particles to thereby prevent the scale from adhering to the pipe. What to prevent,
Alternatively, there is one that removes particles which are deposited in the pipe and cause scale, thereby preventing the scale from adhering to the pipe.

For example, when the liquid in the pipe 2 contains a compound which causes scale, the compound exists in the liquid in the form of fine particles or dissolved. The dissolved compound adheres to the inner wall surface of the pipe 2 to form a scale. On the other hand, the compound in the form of fine particles does not adhere to the inner wall surface of the pipe 2 and does not form scale. Further, when particles having a diameter larger than the fine particles are suspended in the pipe, the particles may be deposited on the bottom of the pipe depending on the flow rate or the flow velocity, and cause scale.

The scale adhesion evaluation method of the present invention can be applied to any scale adhesion prevention method. Therefore, the adhesion of scale can be prevented by precipitating the compound contained in the liquid in the pipe by the magnetic field treatment to form fine particles.

A scale adhesion preventing means 3 is provided for the pipe 2, and a measuring means 1 for measuring fine particles or particles in the liquid in the pipe 2 is provided downstream of the scale adhesion preventing means 3.

The scale adhesion preventing means 3 is, for example, applied with a DC magnetic field or an AC magnetic field as an application example of a method of depositing a compound dissolved in a liquid to prevent the adhesion of scale in a fine particle state. By
Precipitating microcrystals of the compound to be scaled, reducing the adhesion as fine particles in the liquid and increasing the fluidity,
It is difficult to adhere to the inner wall of the pipe. Examples of applying a method of removing particles suspended in the pipe and thereby preventing the scale from adhering to the pipe include, for example, a precipitation treatment and an agglomeration treatment, whereby the scale is removed from the liquid in the pipe. Removes causative particles and prevents scale adhesion.

The scale adhesion preventing means 3 is provided with means (not shown) for setting processing conditions.
By setting conditions based on the measurement result obtained by the measuring means 1, the evaluation according to the present invention can be applied.

In FIG. 1, the measuring means 1 can measure the amount of fine particles or particles contained in the liquid in the pipe by the absorption intensity or turbidity. When measuring the fine particles, the measuring means 1 can use the fact that the infrared spectrum is different depending on the composition of the fine particles. When the fine particles in the liquid are irradiated with light in the infrared region, the measurement is performed. Infrared light is absorbed at different characteristic wavelengths, and its absorption intensity is dependent on the concentration of the fine particles. A value corresponding to the concentration can be measured.

Therefore, according to the measuring means 1, the composition of the fine particles can be known from the characteristic absorption wavelength of the infrared spectrum, and the concentration equivalent of the fine particles is determined from the absorption intensity at the characteristic wavelength of the fine particles. be able to.

When measuring the particles, the measuring means 1 can measure the concentration equivalent of the remaining particles in the pipe as turbidity by absorbance or scattering intensity.

Referring to FIG. 2, a description will be given of a method of obtaining an optimum setting parameter by using the relationship between the absorbance of fine particles in the liquid or the turbidity of the particles and the setting parameter of the scale adhesion preventing means. FIG. 2A shows the relationship between the absorbance of the fine particles in the liquid and the set parameters.
(B) shows the relationship between the turbidity of the particles in the liquid and the set parameters. In FIG. 2A, when the setting parameter is increased (arrow A in the figure) or decreased (arrow B in the figure), if the optimum parameter value is within the fluctuation range of the setting parameter, the maximum or maximum is set. Absorbance C
Is obtained, and the parameter value at this time becomes the optimum parameter value. Therefore, the optimum parameter value can be obtained by obtaining the maximum or maximum absorbance while changing the parameter value.

In FIG. 2B, when the set parameter is increased (arrow a in the figure) or decreased (arrow b in the figure), when the optimum parameter value is within the fluctuation range of the set parameter, Obtains a minimum or minimum turbidity c, and the parameter value at this time is an optimal parameter value. Therefore, the optimum parameter value can be obtained by obtaining the minimum or minimum turbidity while changing the parameter value.

Next, the procedure for evaluating the scale adhesion and setting the parameter value of the scale adhesion preventing means will be described. The method using the absorbance of the infrared region light will be described with reference to the flowchart of FIG. This will be described with reference to a relationship diagram.

First, in the measuring means 1, a measurement wavelength for measuring the absorbance of the fine particles is set. The wavelength at which light is absorbed varies depending on the composition of the fine particles. Therefore, a wavelength at which good absorption is obtained for the composition of the compound contained in the liquid flowing in the pipe is determined in advance. Then, a wavelength corresponding to the compound that prevents the adhesion of the scale is selected from the determined wavelengths and set in the measuring means 1 (step S1).

The measuring means 1 measures the absorbance at the set measurement wavelength, and uses the measured value as an initial value (step S).
2) Perform zero calibration of absorbance using this initial value. S3 in FIG. 4 indicates this zero calibration (step S3).
3).

Next, an initial value is set for the setting parameter of the scale adhesion preventing means 3. S4 in FIG. 4 indicates the initial setting of this parameter (step S4). Measure the absorbance using the set parameter values. S5 in FIG. 4 indicates this absorbance (step S5).

Thereafter, the change in absorbance with respect to the change in the set parameter is measured, and the state of scale adhesion and the scale adhesion prevention processing can be evaluated based on the change in absorbance. For example, an increase in absorbance indicates an increase in fine particles in the liquid in the pipe, a decrease in scale adhesion and an increase in scale adhesion prevention treatment, and a decrease in absorbance indicates a decrease in fine particles in the liquid in the pipe. , The scale adhered, and the scale adhesion prevention treatment was reduced.

Further, by controlling the parameter values so that the absorbance becomes maximum or maximum, optimal control of the set parameters can be performed (step S).
6 to step S14).

For the control of the setting parameters, for example, after S5 shown in FIG. 4, the parameter values are increased. An arrow S6 in FIG. 4 indicates a change in absorbance due to the increase in the parameter value (step S6). At this time, it is determined whether or not the parameter value of the scale adhesion preventing means is within the allowable range, and the magnitude of the parameter value is limited so as to be within the allowable range (step S7). The absorbance at the increased parameter value is measured. S8 in FIG. 4 indicates this absorbance (step S8).

The scale adhesion is evaluated by determining whether or not the measured absorbance has increased (step S9).
4) Steps S6 to S9 are repeated until the absorbance no longer increases.

After the increase of the absorbance with the increase of the parameter value is stopped, the same operation is performed by decreasing the parameter value. An arrow S10 in FIG. 4 indicates a change in absorbance due to the decrease in the parameter value (step S1).
0). At this time, it is determined whether or not the parameter value of the scale adhesion preventing means is within an allowable range, and the magnitude of the parameter value is limited so as to be within the allowable range (step S11).
The absorbance at the decreased parameter value is measured (Step S12).

It is determined whether the measured absorbance has increased (step S13), and steps S10 to S13 are repeated until the absorbance does not increase.

By the above process, a parameter value at which the absorbance is maximum or maximum can be obtained, and the obtained parameter value becomes an optimum parameter value for preventing scale adhesion.

In this state, the process waits for a predetermined time, performs a scale adhesion preventing process, and after the predetermined time has elapsed (step S14), the processes of steps S6 to S14 are repeated again. This makes it possible to set an optimal parameter value corresponding to a change in conditions in the pipe.

The evaluation of the scale adhesion based on the turbidity of the particles obtained by the measurement of the absorbance is the same as the evaluation of the scale adhesion by measuring the absorbance of the fine particles described above. Description is omitted.

Also, in the case where the scale adhesion is evaluated by measuring the turbidity of the particles and the scattering intensity of light, the same evaluation is performed by replacing the absorbance with the scattering intensity in the above-described measurement of the absorbance of the fine particles. Since it can be performed, the description is omitted.

According to the embodiment of the present invention, it is possible to quickly evaluate the scale adhesion state and the effect of the scale adhesion prevention processing, and to apply the evaluation result to the parameter setting of the scale adhesion prevention means.

According to the embodiment of the present invention, when evaluating the scale adhesion by measuring the absorbance of the fine particles, the scale adhesion is evaluated for each composition by measuring the absorbance for each wavelength of light in the infrared region. be able to.

[0049]

As described above, according to the method for evaluating scale adhesion in a pipe according to the present invention, the scale adhesion state can be quickly evaluated, and the method can be applied to setting conditions for scale adhesion prevention processing. it can. In addition, the state of adhesion of the scale for each composition of the compound in the pipe can be evaluated.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram for explaining a method for evaluating the adhesion of scale in a pipe according to the present invention.

FIG. 2 is a diagram for explaining a method of setting an optimum parameter by adhesion evaluation according to the present invention.

FIG. 3 is a flowchart illustrating a procedure for evaluating scale adhesion and setting a parameter value of scale adhesion prevention means according to the present invention.

FIG. 4 is a diagram illustrating a relationship between a parameter value and an absorbance for explaining a procedure for evaluating a scale adhesion and setting a parameter value of a scale adhesion preventing unit according to the present invention.

[Explanation of symbols]

 1 measuring means 2 piping 3 scale adhesion prevention means

Claims (5)

[Claims] 1. A method for evaluating the adhesion of scale in a pipe, comprising measuring a concentration equivalent of fine particles in flowing water in the pipe, and evaluating an adhesion state of the scale in the pipe based on the concentration equivalent. 2. The amount of concentration of the fine particles is determined by measuring the absorption intensity from transmitted light or reflected light obtained by absorbing light by entering light into fine particles in flowing water in a pipe. 2. The method for evaluating adhesion of scale in a pipe according to claim 1, wherein the amount is equivalent to the concentration of fine particles. 3. The method according to claim 1, wherein the incident light is in an infrared region, and the absorption intensity for each wavelength is measured in the infrared region, and the absorption intensity for each wavelength is set as a concentration equivalent amount for each composition of the fine particles. The method for evaluating adhesion of scale in a pipe according to claim 2. 4. A method for evaluating adhesion of scale in a pipe, comprising measuring a concentration equivalent of particles in flowing water in the pipe and evaluating the adhesion state of the scale in the pipe from the concentration equivalent. 5. The method according to claim 4, wherein the turbidity of the flowing water in the pipe is measured by the absorbance or scattering intensity of light, and the turbidity is determined as the concentration equivalent of the particles. A method for evaluating the adhesion of scales in pipes as described.