JP2015117410A - Device and method for removing salt content from metallic member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a method for removing salt content from a metallic member, in each of which the salt content to be generated in a space part (narrow part) of the metallic member or the like is removed.SOLUTION: The device for removing salt content from the metallic member includes: a chlorine collecting member 12 which is stuck to the salt content-stuck metallic member 11 and is kept in a wet state; an electrode film 13 which is press-abutted over the entire surface of the chlorine collecting member 12 on the front surface side; and a DC power supply part 14 to the negative electrode side of which the metallic member 11 is connected and to the positive electrode side of which the electrode film 13 is connected. The power is supplied to the metallic member from the DC power supply part 14 for a predetermined time so that chlorine compounds (such as NaCl) intruded into a fine space (or the narrow part) 21 of the metallic member 11 is electrolyzed and a chlorine ion (Cl) is moved to the side of the chlorine collecting member 12 and kept in the chlorine collecting member 12.

Description

  The present invention relates to a desalting apparatus and method for a metal member that removes salt generated in a gap (narrow portion) such as a blade root of a turbine rotor of a turbine facility or a metal member of a blade groove.

Conventionally, in thermal power generation facilities and the like, boiler steam generated in a boiler is cooled and condensed by a condenser and circulated and used as boiler water (pure water). Here, a cooling pipe for cooling the boiler steam is provided in the condenser, and seawater for cooling flows through the cooling pipe, but when a crack or the like occurs in the cooling pipe, seawater leaks from there. Then, it is mixed in the condensed boiler condensate, and salt is mixed in the boiler condensate to corrode various pipes and the like (for example, see Patent Document 1).
Due to this seawater leakage, when reducing the temperature of high-pressure steam, the water supplied from the condenser is supplied as it is from the temperature-reducing sprayer into the main steam pipe, so that steam containing seawater is supplied to the turbine side. Will be.

  As a result, when operating for a long period of time, salinity, etc. due to seawater leakage enters corrosive substances such as chloride ions into the gaps of the turbine rotor, etc., and corrosion cracks occur in the blade roots and blade grooves. Is concerned.

  For this reason, since it is necessary to remove the corrosive substances that have entered the blade root and blade groove and return them to a healthy state, conventionally, after removing the turbine blades and removing the turbine blades, the corrosive substances are removed. ing.

JP 2001-141596 A

  However, since it is necessary to disassemble the turbine, remove the turbine blades, remove the corrosive substance, and then reassemble the turbine, there is a problem that costs and time are required, resulting in a large loss.

Further, in the cleaning of gaps (narrow parts) such as blade roots and blade grooves of the turbine rotor, there are the following problems.
1) In order to remove salt, it is necessary to dissolve and remove it using an aqueous cleaning solution. However, the cracks in the gaps are narrow and the cleaning solution is difficult to penetrate due to air entrapment. difficult.
2) Therefore, it is necessary to disassemble the turbine rotor, sink each disassembled member in a water tank, etc., and wash the water several times. ) Is concentrated to, for example, about 100 to 1000 ppm, and there is a problem that it is not possible to perform water washing easily in a short time and at low cost.

  Therefore, the advent of a technique that can efficiently remove the salt content in the gap (narrow part) without disassembling the turbine is desired.

  This invention makes it a subject to provide the desalination apparatus and method of a metal member which removes the salt content which generate | occur | produces in clearance gap parts (narrow part), such as a metal member, in view of the said problem.

  The first invention of the present invention for solving the above-mentioned problem is a wet chlorine collecting member adhered to a metal member to which salt is attached, and the surface side of the chlorine collecting member. An electrode film that is pressed against the negative electrode side, and a DC power supply unit that connects the electrode film to the positive electrode side and energizes the negative electrode side. The metal member desalinating apparatus is characterized in that the invading chlorine compound is electrolyzed and held in the chlorine collecting member while being moved to the chlorine collecting member side as chlorine ions.

  According to the present invention, salt can be removed by electrolyzing salt to form chlorine ions and attracting them to the electrode film side on the anode side, thereby collecting the chlorine ions in a wet chlorine collector.

  According to a second invention, in the first invention, the moist chlorine collecting member contains an aqueous silver solution (an aqueous solution of silver acetate or silver hydroxide), and the migrated chlorine ions are immobilized as silver chloride. The present invention provides a desalting apparatus for metal members.

  According to the present invention, salt can be removed by reacting chlorine ions and silver ions to form silver chloride, and collecting the silver chloride by the wet chlorine collector.

  According to a third invention, in the first or second invention, the chlorine collecting member is any one of desalted gauze, non-woven fabric, filter paper, dust-free cloth, or absorbent cotton. Located in the salt device.

  According to the present invention, by using gauze, non-woven fabric, etc., salt can be removed by reliably collecting chlorine ions in a wet chlorine collecting part.

  4th invention sticks the chlorine collection member of a wet state with respect to the metal member to which the salt content has adhered, Then, it presses using the electrode film on the surface side of the said chlorine collection member, The said metal member Is connected to a DC power source with the electrode film as the positive electrode side, and then energized for a predetermined time to electrolyze the chlorine compound that has entered the gaps in the metal member, and the chlorine ions as chlorine ions The metal member is desalted by holding the inside of the chlorine collecting member while being moved toward the collecting member.

  According to the present invention, salt can be removed by electrolyzing salt to form chlorine ions and attracting them to the electrode film side on the anode side, thereby collecting the chlorine ions in a wet chlorine collector.

  According to a fifth aspect of the present invention, there is provided the method for desalinating a metal member according to the fourth aspect of the invention, wherein the chlorine collecting member in a wet state contains an aqueous silver solution and the moved chlorine ions are immobilized as silver chloride. It is in.

  According to the present invention, salt can be removed by reacting chlorine ions and silver ions to form silver chloride, and collecting the silver chloride by the wet chlorine collector.

  According to a sixth invention, in the fourth or fifth invention, the chlorine collecting member is any one of desalted gauze, non-woven fabric, filter paper, dust-free cloth or absorbent cotton. In the salt method.

  According to the present invention, by using gauze, non-woven fabric, etc., salt can be removed by reliably collecting chlorine ions in a wet chlorine collecting part.

  According to the present invention, the salt attached to the metal material is electrolyzed to form chlorine ions, which are attracted to the electrode film side on the anode side, and are collected by collecting the chlorine ions in a wet chlorine collecting part. Can salt.

FIG. 1 is a configuration diagram of a metal member desalting apparatus according to a first embodiment. FIG. 2 is a configuration diagram of a chlorine collecting member and an electrode film that perform desalting according to the first embodiment. FIG. 3 is a conceptual diagram illustrating a state in which chlorine ions (Cl ⁻ ) are attracted to the chlorine collecting member side from the gap between the metal members according to the first embodiment. FIG. 4 is a conceptual diagram illustrating a state in which chlorine ions (Cl ⁻ ) are attracted to the chlorine collecting member side from the gap between the metal members according to the second embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by this Example, Moreover, when there exists multiple Example, what comprises combining each Example is also included.

FIG. 1 is a schematic diagram of a metal member desalting apparatus according to a first embodiment.
As shown in FIG. 1, the metal member desalting apparatus according to the present embodiment includes a wet chlorine collecting member 12 attached to a metal member 11 to which salt is attached, and a chlorine collecting device. An electrode film 13 that is pressed over the entire surface of the member 12, and a direct current power supply unit 14 that is connected to the metal member 11 on the negative electrode side and the electrode film 13 on the positive electrode side and energizes is provided. . Then, the DC power supply unit 14 is energized for a predetermined period of time to electrolyze chlorine compounds (NaCl, etc.) that have entered the fine gaps (or narrow portions) 21 of the metal member 11 and capture chlorine as chlorine ions (Cl ⁻ ). It is held in the chlorine collecting member 12 while being moved to the collecting member 12 side.

  Here, examples of the chlorine collecting member include desalted gauze, non-woven fabric, filter paper, dust-free cloth, or absorbent cotton, and any member can be used as long as it is moist and contains moisture. Can do. These have been desalted in advance.

Therefore, the chlorine collecting member 12 is moistened with moisture, attached in this state to the metal member 11, and then pressed by the electrode film 13 so as to press the entire chlorine collecting member 12.
The addition of water to the chlorine collecting member 12 may be sprayed by a spray means before being pressed by the electrode film 13.
Thereafter, a part of the metal member 11 is connected to the negative electrode side of the DC power supply unit 14, and a part of the electrode film 13 is connected to the positive electrode side of the DC power supply unit 14.
After the connection is completed, a direct current is applied for a predetermined time.
This energization time is about 1 to 10 minutes.

The applied voltage of the DC power supply unit 14 is appropriately selected according to the processing area of the metal member 11, but may be about 1.5 to 40V.
The electrode film 13 is preferably a flat plate of a stainless steel member, a copper member, or a silver member. The thickness of the electrode film 13 may be about 10 to 100 μm.
For example, the gauze or the like of the chlorine collecting member 12 for collecting and collecting chlorine ions has an uneven surface of the treatment surface and the gauze itself, and can be attached so as to stick to the uneven surface of the gauze surface by using the thin electrode film 13. As a result, the current is spread evenly, and the removal efficiency of chlorine ions is increased.

FIG. 2 is a configuration diagram of a chlorine collecting member and an electrode film that perform desalting according to the first embodiment. In FIG. 2, gauze is used as the chlorine collecting member 12, and chlorine ions (Cl ⁻ ) are attracted to the electrode film 13 side from a gap (not shown) of the metal member 11, and the attracted chlorine Ions are collected with gauze.

FIG. 3 is a conceptual diagram illustrating a state in which chlorine ions (Cl ⁻ ) are attracted to the chlorine collecting member 12 side from the gap between the metal members according to the first embodiment. That is, as shown in FIG. 3, when gauze, which is a wet chlorine collecting member 12, is pressed against the surface of the metal member 11, the water 15 penetrates into the gap (narrow part) 21 and enters the deep part of the gap 21. The concentrated chlorine compound (for example, NaCl, β-Fe ₂ (OH) ₃ Cl) is reached, and the chlorine compound is dissociated into chlorine ions.

Then, chlorine ions (Cl ⁻ ) are drawn into the anode (+) side electrode film 13 side by electrolysis, and as a result, move from the surface of the metal member 11 and the gap 21 into the chlorine collecting member 12 and sucked here. Will be collected. Moreover, the chlorine ion in the rust 16 adhering to the surface is collected similarly.

  Here, in this embodiment, this salt removal operation may be performed a plurality of times by replacing the chlorine collecting member 12 with a new one in accordance with the amount of adhering salt.

As a result, salt removal can be performed regardless of the size and shape of the metal member.
Therefore, a conventional cleaning process that requires a large amount of pure water for cleaning is unnecessary (for example, an immersion tank for immersing the turbine rotor, a large cleaning apparatus for jet cleaning, or the like is not required). And in this invention, since the pure water which only makes the chlorine collection member 12 wet is used, in the salt removal process of the salt from the metal member 11, the usage-amount of pure water will be reduced significantly.

Here, conventionally, in the case where salt attached to a metal member is subjected to a water precipitation treatment (soaked in a dipping bath), if the initial amount of chloride ions attached is 100 mg / m ² , a single dipping treatment is performed. Then, since the concentration is reduced only by about 1/10, when the amount of salt is not caused by stress corrosion cracking (for example, 0.5 m / m ² or less), the cleaning process by immersion is performed at least about 3 to 5 times. A large amount of pure water was required to replace the pure water.
On the other hand, in the present invention, the use of pure water only requires the chlorine collecting member 12 to be in a wet state. Note that the surface may be washed away with pure water after the salt removal treatment, but the amount used is insignificant. In addition, when washed with water, drying treatment is performed to prevent generation of rust.

  Here, examples of the metal member to which salt is attached include a boiler casing, a valve, a rotor, a blade, a blade groove (blade root), and the like in which a minute gap (narrow portion) exists in the metal member. However, the present invention is not limited to this.

  Therefore, in a boiler facility, for example, even when a seawater leak of cooling water used in a condenser occurs, a salt removal treatment can be performed by using a small amount of washing water.

FIG. 4 is a conceptual diagram showing a state in which chlorine ions (Cl ⁻ ) are attracted to the chlorine collecting member 12 side from the gap 21 of the metal member 11 according to the second embodiment. In addition, the same code | symbol is attached | subjected to the member which overlaps with the structure of the desalination apparatus of the metal member which concerns on Example 1, and the description is abbreviate | omitted.
In the present embodiment, in the first embodiment, the chlorine collecting member 12 further contains an aqueous silver solution (an aqueous solution of silver acetate or silver hydroxide).
Then, the chloride ions dissociated and moved by electrolysis are immobilized as silver chloride.

Here, as the silver aqueous solution, for example, an aqueous solution of silver acetate (AgC ₂ H ₃ O ₂ ), silver hydroxide (AgOH), or the like can be used.
By impregnating this silver aqueous solution into the chlorine collecting member 12, the migrated chlorine ion reacts with Ag ⁺ (black circle in the figure) to produce Ag ⁺ + Cl ⁻ → AgCl (silver chloride: black triangle in the figure). And is fixed in the chlorine collecting member 12.

11 Metal Member 12 Chlorine Collection Member 13 Electrode Film 14 DC Power Supply 16 Rust 21 Gap (or Narrow)

Claims (6)

A wet chlorine collecting member that is attached to a metal member to which salt is attached,
An electrode film pressed against the surface side of the chlorine collecting member;
A direct-current power supply unit that connects the metal member to the negative electrode side and connects the electrode film to the positive electrode side to energize, and
It is characterized in that it is energized for a predetermined time to electrolyze the chlorine compound that has entered the gap between the metal members and is held in the chlorine collecting member while being moved to the chlorine collecting member side as chlorine ions. Demineralizer for metal parts. In claim 1,
The chlorine collecting member in a wet state contains an aqueous silver solution (an aqueous solution of silver acetate or silver hydroxide),
An apparatus for desalinating a metal member, wherein the moved chlorine ions are fixed as silver chloride. In claim 1 or 2,
The desalination apparatus for metal members, wherein the chlorine collecting member is any one of desalted gauze, non-woven fabric, filter paper, dust-free cloth, or absorbent cotton. A wet chlorine collecting member is attached to a metal member to which salt is attached,
Then, press using the electrode film on the surface side of the chlorine collecting member,
By connecting the metal member as the negative electrode side and connecting the electrode film as the positive electrode side to a direct current power source, and energizing for a predetermined time,
A method for desalinating a metal member, comprising electrolyzing a chlorine compound that has entered a gap between the metal members and moving the chlorine compounds as chlorine ions to the chlorine collecting member side while holding the chlorine compounds in the chlorine collecting member. In claim 4,
Including a silver aqueous solution in the chlorine collecting member in a wet state,
A method for desalinating a metal member, wherein the moved chlorine ions are fixed as silver chloride. In claim 4 or 5,
The method for desalinating a metal member, wherein the chlorine collecting member is any one of desalted gauze, non-woven fabric, filter paper, dust-free cloth, or absorbent cotton.

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