JP6507424B2 - Salinity measurement method and salinity collection device - Google Patents

Description

  The present invention relates to a method for measuring salinity using electrophoresis and a salinity collection device.

  The steel materials that make up the turbine blades and rotors that make up the steam turbine are in an environment where drying and wetting are repeated in operations that involve rotation and stopping. There is a risk that seawater leaks and salt adheres to steel materials such as turbine blades for various reasons and stress corrosion cracking (SCC) of the steel occurs, so it is necessary to manage the salt density adhering to the steel surface .

Conventionally, a clean gauze is used to wipe the surface of the steel material, the salt adhered to the gauze is recovered in purified water, and the sample solution obtained is analyzed with a chromatograph method to determine the salt density on the surface of the steel (Smear method ). However, in order to analyze a trace amount of salt adhering to the steel surface, it is necessary to closely wipe a relatively large area of about 100 to 300 cm ^2, so the problem of how the worker wipes off the analysis results There is.

In addition, it is usually difficult to bring an apparatus for analyzing trace amounts of salt collected in the sample solution to the site, and the sample solution is sent to an analysis room far away from the site and another person is asked to perform the analysis. Is common. Therefore, it is not uncommon to take one to two weeks to obtain analysis results. Then, there is a problem that a delay occurs in the judgment of the risk of SCC. If the adhesion density of chloride ions exceeds the normal standard (for example, 10 mg / m ² ), the entire rotor is lifted out of the turbine casing and the turbine is washed with water, and if necessary, the rotor blades are removed from the rotor Although it is necessary to carry out a large-scale cleaning operation such as removal and hot water cleaning, the delay in the determination of the necessity hinders the resumption of operation of the steam turbine.

  Further, the blade root portion (blade root and blade groove; FIG. 4) connecting the turbine blade and the rotor most likely to be attached with salt is in a narrow place, so wiping is difficult and the portion There is a problem that it is also difficult to accurately grasp the wiping area because there is unevenness on the surface of the steel material that constitutes.

As a conventional method capable of eliminating the influence of the wiping method of the operator and the ambiguity of the wiping area, for example, it is conceivable to use the surface deposit measuring apparatus described in Patent Document 1, but it is relatively complicated at a narrow place. It is still difficult to apply to blade root parts with various uneven surfaces. Also, chloride ion (Cl ^-) To examine the concentration accurately, it is necessary to send the resulting sample solution for analysis chamber, it is also difficult to obtain a rapid measurements on site.

JP, 2013-185911, A

  The present invention has been made to solve the above-mentioned problems, and a method of measuring salinity capable of easily and quickly obtaining accurate adhesion density of chloride ions adhering to a conductive surface such as steel material, and a method of measuring the same. Provide a salt collector for use in

In order to solve the above-mentioned subject, the present invention provides the following means.
A first aspect of the present invention is a salt content measuring method for measuring the adhesion density of chloride ions attached to a conductive surface, wherein the chloride ion is placed in a state where a collector is placed on the measurement area of the conductive surface. And a step of transferring the conductive surface from the conductive surface to the collector by electrophoresis.

  According to the salinity measurement method of the first aspect, since the area of the collection body corresponding to the area of the measurement area can be arbitrarily and accurately adjusted, the measurement area of an arbitrary area corresponding to the narrow portion or the uneven surface is set. be able to. Thereby, the accurate adhesion density of chloride ions can be easily obtained. In addition, since the electrophoresis is completed in a few seconds to a few minutes, measurement results can be obtained quickly.

  A second aspect of the present invention is the method for measuring salinity according to the first aspect, characterized in that a precipitate of transferred chloride ions is generated in the collector.

  According to the salt content measuring method of the second aspect, the collector can be washed with purified water to wash away impurities other than the measurement object. Even after washing, the collected chloride ions are retained in the form of a precipitate in the collector. As a result, more accurate measurement results can be obtained.

  The third aspect of the present invention weighs the mass of the collecting body to which the precipitate adheres, and subtracts the weight of the collecting body determined in advance and subtracts the mass of the collecting body to determine the chloride content in the measurement area from the mass of the precipitate The method for measuring salinity according to the second aspect, further comprising the step of calculating the attachment density of the substance ions.

  According to the salinity measurement method of the third aspect, the precipitate can be weighed using a small electronic balance that is easy to bring to the site. The deposition density of chloride ions can be calculated in situ on the basis of the weighing results.

  A fourth aspect of the present invention is the salt content measuring method according to any one of the first to third aspects, wherein the collection body is a filter paper.

  According to the salinity measurement method of the fourth aspect, the area of the collector corresponding to the measurement region can be easily adjusted. In addition, it is possible to electrophorese at a low voltage, and chloride ions can be collected more reliably. Furthermore, the operation of generating the collected chloride ion precipitate is facilitated.

  According to a fifth aspect of the present invention, the filter paper containing purified water is brought into close contact with the conductive surface, an electrode is placed on the filter paper, and a voltage is applied between the conductive surface and the electrode. The method according to the fourth aspect is characterized in that the electrophoresis is performed.

  According to the salinity measurement method of the fifth aspect, electrophoresis can be performed at a relatively low voltage of about 1.5 to 9 V obtained by series connection of several dry batteries, and chloride ions can be conveniently collected. can do. Furthermore, the work is excellent because the work of generating the collected chloride ion precipitates can be performed immediately by removing the filter paper after electrophoresis.

  A sixth aspect of the present invention is the method for measuring salinity according to the second or third aspect, wherein the precipitate is silver chloride.

  According to the method of measuring the salinity of the sixth aspect, silver chloride is insoluble in water and is retained in a stable state by the collector, so the collector is washed with purified water to remove impurities other than silver chloride Even after this, silver chloride remains in the collector. As a result, more accurate measurement results can be obtained.

A seventh aspect of the present invention is the salt content measuring method according to any one of the first to sixth aspects, wherein an area of the measurement area is 0.5 to ⁵ cm ² .

  According to the salinity measurement method of the seventh aspect, the measurement region can be set on the narrow portion or the uneven surface. As a result, it is possible to easily calculate the local adhesion density of chloride ions which is difficult to measure by the conventional smear method.

  The eighth aspect of the present invention is characterized in that a dust guard means is interposed between the conductive surface and the collector, for preventing dust on the conductive surface from adhering to the collector. The salt content measuring method according to any one of the first to seventh aspects.

  According to the salt content measuring method of the eighth aspect, the dust such as rust or dust attached to the surface to be measured can be prevented from adhering to the collecting body, so that the dust can be prevented from affecting the measurement result.

  A ninth aspect of the present invention is a collector mounted on a conductive surface to be measured, which collects chloride ions, an electrode connected to the collector, a voltage between the electrode and the conductive surface And a voltage application means for applying a voltage.

  According to the salt collection device of the ninth aspect, the adhesion density of chloride ions can be measured simply and quickly. In addition, since the device configuration is simple, it can be easily carried.

According to the salinity measurement method of the present invention, the area of the collection body corresponding to the area of the measurement area can be arbitrarily and accurately adjusted, so that the measurement area of an arbitrary area according to the narrow portion or the uneven surface is set. Can. Thereby, accurate adhesion density of chloride ions can be easily obtained. In addition, since the electrophoresis is completed in a few seconds to a few minutes, measurement results can be obtained quickly.
According to the salinity collection device of the present invention, the adhesion density of chloride ions can be measured simply and quickly. In addition, since the device configuration is simple, it can be easily carried.

It is the schematic diagram which showed a mode that the adhesion density of the chloride ion of electroconductive surface S is measured in 1st embodiment of this invention. It is the schematic diagram which showed a mode that the adhesion density of the chloride ion of electroconductive surface S is measured in 2nd embodiment of this invention. It is the schematic diagram which showed a mode that the adhesion density of the chloride ion of electroconductive surface S is measured in 3rd embodiment of this invention. It is a cross-sectional schematic diagram which shows a mode that the blade root of the turbine blade fitted to the blade groove | channel of a rotor.

<< Salt collection device >>
FIG. 1: is an example (it calls the collection apparatus 10 hereafter) applicable to 1st embodiment of the salt measuring method concerning this invention. The collecting apparatus 10 is installed on the conductive surface S to be measured, and is between the collector 2 for collecting chloride ions, the electrode 2 connected to the collector 1, the electrode 2 and the conductive surface S. A voltage application means 3 for applying a voltage and an ammeter 4 are provided.

  The collector 1 for collecting chloride ions is not particularly limited as long as it is a member capable of holding chloride ions transferred by electrophoresis. For example, a fiber member such as filter paper, non-woven fabric, woven fabric, etc. It can be mentioned. Since these fiber members can hold moisture, it is preferable because a voltage can be easily applied when the chloride ions are electrophoresed. It is preferable that the chloride ion which is a measuring object does not adhere to the collection body 1 before use. Chloride ions can be removed by thoroughly washing with purified water (ion-exchanged water) prior to installation on the conductive surface S.

When using filter paper as the collection body 1, the thickness is not specifically limited, For example, about 5 micrometers-about 1000 micrometers are preferable.
When the thickness is 5 μm or more, preferably 100 μm or more, chloride ions can be prevented from passing through the collector 1 and reaching the electrode 2. If the thickness is 1000 μm or less, the voltage required for electrophoresis does not become too high, and electrophoresis can be performed with a voltage that can be obtained with several dry batteries. A filter paper suitable as the collection body 1 includes a known quantitative filter paper.

  The electrode 2 connected to the collection body 1 is not particularly limited as long as it is a conductive member capable of conducting to the collection body 1 a voltage required for electrophoresis supplied from the voltage application means 3, and known electrodes Is applicable. For example, a platinum electrode (platinum electrode) having corrosion resistance is preferred.

  The method of connecting the electrode 2 to the collection body 1 is not particularly limited as long as it is a connection method capable of conducting the current necessary for the electrophoresis supplied from the voltage application means 3 to the collection body 1. For example, a method of connecting so that the conductive surface of the electrode 2 is in close contact with at least a part, preferably all of the first surface (one surface) of the collection body 1 may be mentioned. According to this connection method, since the voltage can be applied almost equally to the entire surface of the collector 1, chloride ions transferred from the conductive surface S can be efficiently collected on the entire surface of the collector 1. Moreover, you may employ | adopt the method of connecting the electrode 2 only to the edge part of the collection body 1 as another connection method.

The voltage application means 3 is a means capable of applying a voltage necessary for causing chloride ions to electrophorese from the conductive surface S to the collector 1 between the collector 1 and the conductive surface S via the electrode 2. There is no particular limitation, and for example, a known DC power supply is preferable. As the DC power supply, for example, a dry cell battery which can be easily carried is suitable. The voltage applied by the voltage applying means 3 depends on, for example, the size of the collector 1 and the area of the measurement region R, but, for example, when a filter paper of 0.5 to 10 cm ² is used as the collector 1, 1.0 to 10 V, for example. A degree of voltage is preferred. When the voltage is in the above range, chloride ions can be sufficiently collected in a short time.

  In the collection device 10, the electrode 2 connected to the collection body 1 and the positive electrode of the voltage application means 3 are connected by a conducting wire, and the negative electrode of the voltage application means 3 and the conductive surface S are electrically connected. A conducting wire is drawn from the negative electrode of the voltage application means 3. In addition, a known ammeter 4 is provided in the middle of the conduction extracted from the negative electrode. The collection device 10 may have other configurations. An embodiment of a salinity measurement method using the collection device 10 will now be described.

Method of measuring salinity
First Embodiment
The first embodiment of the method for measuring salt content according to the present invention is a method for measuring the salt content of chloride ions (Cl ⁻ ) attached to a conductive surface, which is provided on the measurement area of the conductive surface. It has the process of making the said chloride ion transfer to the said collection body from the said electroconductive surface by electrophoresis in the state which mounted the collection body. The present embodiment may have a process of performing other processes other than the above process. Hereinafter, this will be specifically described with reference to FIG.

  The object to be measured is not particularly limited as long as it has the conductive surface S, and, for example, the surface of a steel material constituting a moving blade or a rotor of a steam turbine may be mentioned.

The measurement region R of the conductive surface S corresponds to a region where the collector 1 and the conductive surface S are in contact or a region where the collector 1 and the conductive surface S overlap when viewed from above. According to the present embodiment, the area of the measurement region R can be set to, for example, 0.5 to 5 cm ² . Therefore, it is possible to set as the measurement region R a region where there is unevenness such as the blade root of the moving blade or the blade groove of the rotor at the connection portion between the moving blade and the rotor. For example, when 1 cm ² of the collection body 1 is in close contact with the blade root, the area of the measurement region R is naturally 1 cm ² . In calculating the salinity density, it is important to accurately know the area of the measurement region R.

When the collecting body 1 is installed on the conductive surface S, it is preferable to bring the first surface (one side) of the collecting body 1 into close contact with the conductive surface S. For example, when filter paper is used as the collection body 1, purified water is included in the filter paper so as to be in close contact with the conductive surface S so that air bubbles are not sandwiched. By using filter paper as the collection body 1, the collection body 1 can be stuck along the unevenness of the conductive surface S.
The electrode 2 is installed on the second surface (other surface) of the installed collector 1. For example, in the case of using a platinum electrode plate (electrode foil) as the electrode 2, it is superimposed on the second surface of the filter paper and closely attached so that air bubbles are not sandwiched between the filter paper.

  The positive electrode of the voltage application means 3 is connected to the electrode 2, and the negative electrode is connected to the conductive surface S in the vicinity where the collector 1 is installed. When using voltage application means 3 with one or more 1.5 V dry batteries connected in series in a battery socket with a switch function, a copper wire drawn from the positive electrode of the battery is placed at the center or end of the platinum electrode plate The connection is made, and the copper wire drawn from the negative electrode of the battery is brought into contact with the conductive surface S in the vicinity of the measurement area R where the filter paper is installed. Thus, a switchable circuit is formed.

  By applying a voltage by the voltage application means 3, a current flows in the closed circuit formed by the installed collection device 10, and the chloride ions adhering to the conductive surface S are electrophoresed to form the collection body 1. Migrate to The fact that almost all of the chloride ions adhering to the conductive surface S are transferred to the collector 1 can be confirmed by the decrease in the current indicated by the ammeter 4. After this confirmation, the voltage application is stopped and the electrophoresis is finished. It is possible to prevent the chloride ion from reaching the electrode 2 by setting the open circuit immediately after confirming the current decrease except in the case where the thickness of the collection body 1 is extremely thin. When filter paper containing purified water is used as the collecting body 1, it is possible to sufficiently prevent chloride ions from passing through the filter paper and penetrating to the platinum electrode plate side when the thickness is, for example, 100 μm to 1000 μm.

  In the collector 1, it is preferable to generate a precipitate of transferred chloride ions. Since the precipitate tends to adhere to the collector 1, the chloride ions constituting the precipitate can be more reliably retained in the collector 1. The precipitate of chloride ion is preferably a substance insoluble or sparingly soluble in the solvent in which electrophoresis is to be performed, usually water.

  The type of the precipitate of the chloride ion is not particularly limited, and is preferably an ionic compound insoluble or poorly soluble in water. Silver chloride is mentioned as a suitable example. Silver chloride is particularly suitable for the method of measuring salinity according to the present embodiment because it is stable until weighed later, is easily produced, and is difficult to peel or detach from the filter paper.

As a method of generating a precipitate of chloride ions in the collector 1, for example, a method of causing the collector 1 to have a cation causing a precipitation reaction with a chloride ion can be mentioned. The cations may be supplied to the collector 1 after chloride ions are transferred to the collector 1, or even if the collector 1 is provided in advance before chloride ions are transferred to the collector 1. Good. Specifically, for example, a method in which the solution 5 containing the cation is dropped onto the collector 1, a method in which the cation is mixed in advance with the constituent material of the collector 1, and the like can be mentioned. By using, for example, silver ion (Ag ⁺ ) as the cation, silver chloride as the precipitate can be easily generated.

  When dropping the solution 5 containing the cation into the collecting body 1, it is preferable to drop the solution 5 with the surface where the collecting body 1 was in contact with the conductive surface S upward. In the collector 1, it is considered that there is a concentration gradient in which many chloride ions are distributed on the surface side in contact with the conductive surface S. Therefore, by dropping the solution 5 onto the surface from above, the generated precipitate is more reliably retained inside the collector 1.

The type of the solution 5 containing the cation is not particularly limited. For example, when using a solution containing silver ions, an aqueous solution of silver nitrate (AgNO ₃ ) which is easy to handle is preferable.
Although the density | concentration in particular of silver nitrate dripped is not limited, For example, 0.5-10 mass% concentration is preferable. Within the above concentration range, silver chloride can be sufficiently produced by the dropwise addition of a small amount, for example 0.2 to 10 ml / cm ² .
In place of the silver nitrate aqueous solution, for example, silver acetate (AgC ₂ H ₃ O ₂ ), silver sulfate (Ag ₂ SO ₄ ) or the like can be used in the same manner.

  While the nitrate ion and other impurities are washed away by a gentle method in which the precipitate of chloride ions generated in the collector 1 does not flow out, the precipitate is left in the collector 1. As a gentle washing method, for example, there is a method of rinsing out impurities by gently immersing the collector 1 in purified water. After washing, the collector 1 and the precipitate are dried to remove water and the like, whereby the precipitate containing chloride ions can be accurately quantified.

  By weighing the precipitate generated in the collector 1, the collected chloride ions can be quantified based on the mass ratio of the chloride ions that constitute the precipitate. Using a commercially available high-performance electronic balance, for example, an ultra-micro balance, it is possible to accurately measure as little as 0.1 to 5 μg of precipitate. Precipitates exceeding 5 μg may be similarly weighed using a conventional electronic balance.

  Specifically, first, the mass of the collection body 1 to which the precipitate adheres is weighed, and the mass of the precipitate is determined by subtracting the mass of the collection body 1 that has been weighed in advance. From the viewpoint of accurate weighing, it is preferable to weigh the collector and the precipitate in a dried state. The mass of the chloride ion can be determined by multiplying the determined mass of the precipitate by (atomic weight of chlorine / molecular weight of the precipitate). For example, if 10 μg of silver chloride was weighed as the precipitate, then (10 × (35.45 ÷ 143.32) = 2.48 μg is the mass of chloride ions collected.

Subsequently, the adhesion density of chloride ions in the measurement region R is calculated. Specifically, the mass of the collected chloride ions may be divided by the area of the measurement region R in which the collector 1 is in close contact with the conductive surface S. For example, the adhesion density of chloride ions is calculated as (mass of 2.48 μg of collected chloride ions) ÷ (area of 1 cm ^{2 of} filter paper) = 2.48 μg / cm ² = 24.8 mg / m ² it can.

  As described above, according to the salt content measuring method of the present embodiment, the accurate adhesion density of chloride ions can be measured simply and quickly for a narrow measurement area such as a blade root part suspected of having salt content attached. be able to.

Second Embodiment
In the second embodiment of the salt content measuring method according to the present invention, in the first embodiment, the collection body 1 is previously provided with the cation. Hereinafter, this will be specifically described with reference to FIG.

  In order to be in close contact with the measurement area R of the conductive surface S, a collection body 1 ′ provided with the cation in advance is installed. As the collection body 1 ', for example, a filter paper on which the cation is previously adsorbed is preferable. Specifically, for example, filter paper on which silver ions are adsorbed (so-called silver filter) can be mentioned. A commercially available silver membrane filter may be used, or a silver filter produced by a method of dropping a solution containing silver ions such as a silver nitrate aqueous solution onto filter paper and drying may be used.

Even in the case of using the collection device 10 provided with the collection body 1 ′, it is possible to carry out the salinity measurement method as in the first embodiment. That is, by electrophoresis, chloride ions are transferred to the silver filter containing water in advance, and a precipitation reaction of chloride ions and silver ions occurs in the silver filter. If necessary, the collector 1 ′ is washed with purified water to wash away unnecessary components (impurities) attached during electrophoresis, while leaving the produced silver chloride. After drying the silver filter, the silver chloride held in the collector 1 ′ is weighed, and the adhesion density of chloride ions is calculated based on the area of the measurement region R.
Also in the second embodiment, as in the first embodiment, accurate deposition density of chloride ions can be measured simply and quickly.

Third Embodiment
According to a third embodiment of the salt content measuring method of the present invention, in the first embodiment, the dust adhering to the conductive surface S adheres to the collector 1 between the conductive surface S and the collector 1 Means for preventing dust and dirt are interposed. Hereinafter, this will be specifically described with reference to FIG.

  When dust such as rust or dust adheres to the surface of the conductive surface S, it is not desirable to wipe them. This is because chloride ions may be removed together with dust during cleaning. On the other hand, if dust adheres to the collector 1, there is a risk that accurate weighing results can not be obtained when weighing chloride ion precipitates. Therefore, by installing the dust protection means 6 between the conductive surface S and the collecting body 1, the adhesion of the dust to the collecting body 1 is prevented.

  The dustproof means 6 is not particularly limited as long as it is a means that does not inhibit migration of chloride ions from the conductive surface S to the collector 1 by electrophoresis. For example, filter paper containing purified water is suitable. However, in order to prevent the filter paper as the dustproof means 6 from retaining the electrophoresed chloride ions, a thin filter paper is used.

The thickness of the filter paper as the dustproof means 6 is preferably, for example, 1 μm to less than 100 μm, more preferably 1 to less than 50 μm, and still more preferably 1 to less than 20 μm. If the thickness of the filter paper is thin, chloride ions can pass through the filter paper as the dust separating means 6 and reach the collector 1 during electrophoresis. As such a filter paper, so-called commercially available qualitative filter paper can be applied. Also, from the viewpoint of easy passage of chloride ions, it is preferable that the density of the filter paper be low.
When a filter paper is used as the collection body 1, a filter paper thicker than the filter paper of the dustproof means 6 is used to reliably collect chloride ions.

  As shown in FIG. 3, a method can be exemplified in which the dustproof means 6, the collector 1, and the electrode 2 are stacked in order and placed on the conductive surface S in close contact with each other. In this installation mode, it is preferable that the dust protection means 6 have a larger area than the collection body 1. Furthermore, it is preferable that the collector 1 and the electrode 2 have the same area. When electrophoresis is performed in this installation mode, chloride ions attached to the conductive surface S are migrated vertically upward to the electrode 2, that is, in the normal direction of the conductive surface S, so the area of the measurement region R is It can be said that the area is equal to that of the collector 1 and the electrode 2.

Even in the case of using the collection device 10 provided with the dustproof means 6, the method of measuring salinity can be performed as in the first embodiment. Chloride ions attached to the conductive surface S by electrophoresis pass through the dustproof means 6 and are collected by the collector 1. Thereafter, the collection body 1 is taken out of the dustproof means 6, and chloride ions transferred to the collection body 1 to which no dust is attached are quantified in the same manner as in the first embodiment. Calculate the adhesion density of chloride ions.
Also in the third embodiment, as in the first embodiment, accurate deposition density of chloride ions can be measured simply and quickly. Further, even when the dustproof means 6 is installed in the second embodiment, the salt content measuring method can be carried out as in the third embodiment.

  As mentioned above, although the embodiment of the salt measuring method and chloride ion measuring device of the present invention was described, the present invention is not limited to the above-mentioned embodiment, and can be suitably changed in the range which does not deviate from the meaning of the present invention It is possible to replace the components in the above-described embodiment with known components as appropriate.

  EXAMPLES The present invention will next be described in more detail by way of examples, which should not be construed as limiting the invention thereto.

Example 1
A 1 cm square filter paper, which had been moistened with purified water in advance, was adhered to the steel surface of the blade root portion of the turbine blade where it was suspected that seawater was attached. A 1 cm square platinum electrode was stacked on the filter paper and placed in close contact with the filter paper. The positive electrode of four 1.5 V dry batteries connected in series was connected to a platinum electrode via a copper wire, and the negative electrode was connected to the steel surface to form a circuit (FIG. 1 (a)).
Chloride ions were collected by the filter paper by causing chloride ions adhering to the surface of the steel material to electrophorese on the filter paper by flowing a current in a closed circuit. At this time, the current value was monitored by an ammeter installed in the circuit, and when the current was sufficiently lowered, the circuit was returned to the open circuit to finish the electrophoresis (FIG. 1 (b)).
The filter paper from which chloride ions were collected was removed from the surface of the steel material, and a small amount of silver nitrate solution was dropped from above with the surface of the filter paper in contact with the steel surface directed upward. Due to this dropping, a precipitation reaction of silver chloride (Cl ⁻ + Ag ⁺ → AgCl) occurred in the filter paper (FIG. 1 (c)).
Thereafter, the filter paper was washed with purified water for the purpose of washing out unnecessary components such as nitrate ion and sodium ion. Subsequently, the filter paper on which the precipitated silver chloride has been collected is dried, weighed with an ultramicrobalance (Model Sartorius, model MSA), and collected on the filter paper based on the weight of the filter paper before use. The mass of silver chloride was calculated. From the amount 0.4 [mu] g / cm ² of the collected silver chloride, found that adhesion density of the deposited have a chloride ion in the measurement region of the steel material surface is 0.1 [mu] g / cm ^2, i.e., 1 mg / ^{m 2} The
All the processing required for the above measurements could be carried out conveniently and quickly beside the turbine.

Example 2
The following procedure is carried out in the same manner as in Example 1, except that a water-absorbing silver filter (manufactured by Tech Jam Inc., manufactured by Agilent, manufactured by Thermo, etc.) in which silver ions are incorporated is used instead of filter paper. The salinity of the steel surface was measured.
A 1 cm square silver filter, which had been moistened with purified water in advance, was adhered to the steel surface of the blade root portion of the turbine blade where it was suspected that seawater was attached. A platinum electrode of 1 cm square was overlapped on this silver filter and placed in close contact with the silver filter. The positive electrode of four 1.5 V dry cells connected in series was connected to a platinum electrode via a copper wire, and the negative electrode was connected to the surface of a steel material to form a circuit (FIG. 2 (a)).
Chloride ions were collected by a silver filter by causing chloride ions attached to the surface of the steel material to electrophorese on a silver filter by flowing a current in a closed circuit. At this time, the current value was monitored by an ammeter installed in the circuit, and when the current was sufficiently lowered, the circuit was returned to the open circuit to complete the electrophoresis (FIG. 2 (b)).
The silver filter from which chloride ions were collected was removed from the steel surface. It was not necessary to use a silver nitrate solution as the chloride ions were precipitated by the precipitation reaction (Cl ⁻ + Ag ⁺ → AgCl) as soon as they migrated into the silver filter.
The silver filter was washed with purified water for the purpose of washing away unnecessary impurities such as dust. Subsequently, the silver filter on which the precipitated silver chloride is collected is dried, weighed with an ultramicrobalance (Model Sartorius, type MSA), and captured by the silver filter based on the weight of the silver filter before use. The mass of the collected chloride ion was calculated. All of the increased weight was considered to be derived from chloride ions, so it was found that the adhesion density of chloride ions adhering to the measurement area on the steel surface was 0.1 μg / cm ² , that is, 1 mg / m ² The
All the processing required for the above measurements could be carried out conveniently and quickly beside the turbine.

[Example 3]
Between filter paper (collection filter paper) used for the purpose of collecting chloride ions and steel material surface, filter paper thinner than collection filter paper and having low density (rust filter paper) was installed on steel material surface The salt content of the surface of the steel material was measured in the same manner as in Example 1 as follows.
A 1.5 cm square rust proof paper moistened with purified water was brought into contact with the surface of the steel material at the blade root portion of the turbine blade suspected of having seawater attached. A 1 cm square collection filter paper previously moistened with purified water was adhered onto this rustproof paper. A platinum electrode of 1 cm square and a 1 cm square of platinum electrode were stacked on the collection filter paper and placed in close contact with the collection filter paper. The positive electrode of four 1.5 V dry cells connected in series was connected to a platinum electrode via a copper wire, and the negative electrode was connected to the surface of a steel material to form a circuit (FIG. 3 (a)).
A chloride ion adhered to the surface of the steel material was electrophoresed on a collection filter by flowing a current in a closed circuit, and the chloride ion was collected by the collection filter. At this time, the current value was monitored by an ammeter installed in the circuit, and when the current was sufficiently lowered, the circuit was returned to the open circuit to finish the electrophoresis (FIG. 3 (b)).
The collection filter paper on which chloride ions were collected was removed from the rust-proof filter paper, and a small amount of silver nitrate solution was dropped from above with the surface of the collection filter paper in contact with the rust-proof filter facing upward. By this dropping, a precipitation reaction (Cl ⁻ + Ag ⁺ → AgCl) of silver chloride occurred in the collection filter (FIG. 3 (c)).
Thereafter, the collected filter paper was washed with purified water for the purpose of washing out impurities such as nitrate ion and sodium ion. Subsequently, the collected filter paper on which the precipitated silver chloride is collected is dried, weighed with an ultramicrobalance (MSA type, MSA type), and collected based on the weight of the collected filter paper before use. The mass of silver chloride collected on the filter paper was calculated. From the amount 0.4 [mu] g / cm ² of the collected silver chloride, found that adhesion density of the deposited have a chloride ion in the measurement region of the steel material surface is 0.1 [mu] g / cm ^2, i.e., 1 mg / ^{m 2} The
All the processing required for the above measurements could be carried out conveniently and quickly beside the turbine.

Comparative Example 1
A measuring area of about 200 cm ² of the steel surface of a turbine blade suspected of having salty water from seawater was wiped using 1 to 10 g of cotton gauze with purified water. At the time of wiping, workers wore salt-free rubber gloves.
The wiped gauze was immersed in 50 ml of purified water in a beaker and heated for 30 minutes at 100 ° C. using a heater with the lid covered to prevent evaporation. After cooling to room temperature, the gauze was removed, the gauze was squeezed, and the purified water brought out by the gauze was returned to the beaker. Next, the squeezed gauze was immersed in 50 ml of purified water in another beaker, and the heating, cooling and squeezing process was repeated twice more. This obtained the sample solution which dissolved the salt wiped off with gauze in a total of 150 ml purified water.
The sample solution was sent to a facility equipped with a chromatograph apparatus for analysis to request quantitative analysis of trace salts contained in the sample solution. From the analysis results notified about one week later, it was found that the adhesion density of chloride ions attached to the steel surface was about 0.5 to ² mg / m ² .

  In the comparative example 1, when selecting the area | region which wipes off, the blade-root site | part most suspected that salt content adhered was not able to be selected. Since the blade root portion has irregularities, it is difficult to estimate the wiping area accurately, and since it is a narrow portion, the wiping operation is difficult. Therefore, a relatively flat and wide area was selected and wiped. However, since the flat and wide area is a place where salinity is difficult to accumulate in view of the structural characteristics of the turbine blade, there is a concern that the measured value becomes lower than the narrowest place to be measured most.

As described above, according to the measurement methods of Examples 1 to 3, accurate deposition density of chloride ions can be obtained at the so-called on-site (local site) for the local portion of the blade root portion where it is suspected that salt content is attached. It was possible to measure simply and quickly. Based on this result, it was possible to accurately and promptly determine the necessity of a large-scale cleaning operation involving the disassembly of the turbine blade.
On the other hand, in the measurement method of Comparative Example 1, since the measurement results could not be obtained on site, it was not possible to immediately determine the necessity of a large-scale cleaning operation, and the turbine was stopped for about one week before resuming operation. I had to.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the respective configurations and the combinations thereof in the respective embodiments are merely examples, and addition of known configurations is possible without departing from the spirit of the present invention. , Omissions, substitutions, and other changes are possible. Furthermore, the present invention is not limited by the embodiments, and is limited only by the scope of the claims.

  The present invention can be widely used in the field of using steel materials such as turbines and ships.

DESCRIPTION OF SYMBOLS 1 ... collection body, 2 ... electrode, 3 ... voltage application means, 4 ... ammeter, 5 ... solution containing a cation, 6 ... refuse elimination means, S ... conductive surface, R .. measurement area, s1 ... steam turbine Blade root, s2 ... blade groove of steam turbine rotor

Claims (9)

A salinity measurement method for measuring the adhesion density of chloride ions attached to a conductive surface, comprising:
And a step of transferring the chloride ion from the conductive surface to the collector by electrophoresis in a state where the collector is placed on the measurement area of the conductive surface.   The method for measuring salinity according to claim 1, wherein a precipitate of transferred chloride ions is generated in the collector.   The mass of the collection body to which the precipitate is attached is weighed, and the adhesion density of chloride ions in the measurement area is calculated from the mass of the precipitate obtained by subtracting the mass of the collection body that has been weighed in advance. The method for measuring salinity according to claim 2, further comprising a step.   The method for measuring salinity according to any one of claims 1 to 3, wherein the collecting body is filter paper.   The filter paper containing purified water is brought into close contact with the conductive surface, an electrode is placed on the filter paper, and a voltage is applied between the conductive surface and the electrode to perform the electrophoresis. The method for measuring salinity according to claim 4, characterized in that.   The method for measuring salinity according to claim 2 or 3, wherein the precipitate is silver chloride. The area of the said measurement area | region is 0.5-5 cm < ² >, The salt content measuring method as described in any one of Claims 1-6 characterized by the above-mentioned.   8. A dustproof means is interposed between the conductive surface and the collecting body, for preventing dust on the conductive surface from adhering to the collecting body. Method of measuring salinity according to any one of the items. A collector placed on the conductive surface to be measured and collecting chloride ions;
An electrode connected to the collector;
Voltage applying means for applying a voltage between the electrode and the conductive surface;
A salinity collection device comprising:

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