WO2016132565A1

WO2016132565A1 - Electrolysis system

Info

Publication number: WO2016132565A1
Application number: PCT/JP2015/057942
Authority: WO
Inventors: 勇作那須; 達也松村; 水谷　洋; 中村　謙治; 宏幸高波
Original assignee: 三菱重工環境・化学エンジニアリング株式会社
Priority date: 2015-02-17
Filing date: 2015-03-17
Publication date: 2016-08-25
Also published as: MY188112A; CN106061904B; KR20160124177A; JP2016150298A; KR101910262B1; JP6344857B2; TWI564436B; TW201631221A; CN106061904A; SA516371888B1

Abstract

Provided is an electrolysis system (1) having: an electrolysis device (2), which has an electrolysis vessel (6), wherein a positive electrode and a negative electrode are accommodated for the electrodes, and which is for electrolysis of a fluid to be processed; a regulating tank (3) for temporarily retaining the fluid to be processed that is processed by the electrolysis device (2); a recycling line (10) for returning part of a retained fluid (R) that includes microparticles and a deposited substance wherein microparticles have been deposited and that has been retained in the regulating tank (3) to the electrolysis vessel (6); and a prevention means (18) for preventing sedimentation of the deposited substance in the regulating tank (3).

Description

Electrolysis system

The present invention relates to an electrolysis system including an electrolyzer that electrolyzes a liquid to be treated such as seawater.
This application claims priority in Japanese Patent Application No. 2015-028499 for which it applied on February 17, 2015, and uses the content here.

Conventionally, in thermal power plants, nuclear power plants, seawater desalination plants, chemical plants, etc. that use a large amount of seawater, the algae and shellfish that are in contact with seawater such as intakes, piping, condensers, and various coolers Adherence breeding has become an issue.
In order to solve this problem, an electrolysis system that generates sodium hypochlorite (chlorine, sodium hypochlorite) by electrolyzing natural seawater has been proposed. This system suppresses the adhesion of marine organisms by injecting an electrolytic solution containing sodium hypochlorite into a water inlet (see, for example, Patent Document 1). In general, in this system, scale is generated due to scale components such as magnesium ions in seawater.

Patent Document 1 describes an apparatus that supplies air into a liquid to be treated in order to prevent scale from adhering to an electrode of an electrolysis apparatus during electrolysis. This apparatus improves the electrode cleaning effect by increasing the flow velocity on the electrode surface and making it turbulent by blowing air into the liquid to be treated.

Japanese Patent No. 4932529

However, in a system that circulates the liquid to be treated discharged from the electrolyzer to the adjustment tank (circulation tank), the scale is placed at the bottom of the electrolytic tank (electrode surface) for electrolysis and the adjustment tank for temporarily storing the liquid to be treated. There is a problem of precipitation.
The removal of the precipitated scale requires a large-scale work such as an acid cleaning work, which increases the running cost of the electrolytic system.

An object of the present invention is to provide an electrolysis system capable of preventing a deposited substance (scale) from being precipitated at the bottom of a regulating tank.

According to the first aspect of the present invention, an electrolysis system includes an electrolyzer that contains an anode and a cathode as electrodes, and electrolyzes a liquid to be treated, and a treatment to be treated by the electrolysis device. An adjustment tank for temporarily storing the liquid, a recycle line for returning a part of the stored liquid, which is stored in the adjustment tank and contains the fine particles and the precipitated substance formed by precipitation of the fine particles, to the electrolytic cell, and in the adjustment tank And a preventive means for preventing precipitation of the precipitated substance.

According to such a structure, it can prevent that a deposit substance precipitates in the bottom part of an adjustment tank by a prevention means.
In addition, when the stored liquid is returned to the electrolytic cell, the fine particles contained in the stored liquid are desorbed along with the deposited substances generated on the electrode surface. Thereby, accumulation of the deposited substance on the electrode surface can be prevented. That is, the fine particles contained in the stored liquid returned to the electrolytic cell function as seed crystals, so that it is possible to suppress the growth of the deposited substance on the electrode surface.
In addition, precipitates such as calcium carbonate and magnesium hydroxide that precipitate due to the increase in pH of the liquid to be treated with electrolysis are separated from the electrode surface on the surface of fine particles (seed crystals) that float in the liquid. By precipitating, it is possible to prevent deposition of the depositing substance on the cathode surface.

In the electrolysis system, the prevention means may include a discharge pipe for discharging a liquid to the adjustment tank.

According to such a configuration, the liquid stored in the adjustment tank is agitated by injecting the liquid through the discharge pipe. Thereby, the effect which prevents that a deposit substance precipitates in the bottom part of an adjustment tank can be raised.

In the electrolysis system, the discharge pipe may be discharged in a direction in which a swirling flow is generated in the stored liquid stored in the adjustment tank.

According to such a configuration, the precipitation substance contained in the stored liquid can be stably stirred, so that the effect of preventing the precipitation substance from being precipitated at the bottom of the adjustment tank can be improved.

In the electrolysis system, the prevention means supplies air to a wall member that extends in the vertical direction of the adjustment tank and divides the inside of the adjustment tank into an ascending part and a descending part, and a lower part of the ascending part And an air stirrer having an air supply unit.

According to such a configuration, the agitation / dispersion effect of the stored liquid can be obtained by the aeration power of air. Thereby, the effect which prevents that a deposit substance precipitates in the bottom part of an adjustment tank can be raised.

In the electrolysis system, the prevention means may be a mechanical stirring device that mechanically stirs the stored liquid in the adjustment tank.

According to such a configuration, the stored liquid is forcibly stirred. Thereby, the effect which prevents that a deposit substance precipitates in the bottom part of an adjustment tank can be raised.

In the above electrolysis system, the anode may be coated with titanium with a coating material containing iridium oxide.

According to such a configuration, even when the anode is formed by coating titanium with a coating material containing iridium oxide, which easily adheres to manganese scale during electrolysis, the growth of deposited substances on the electrode surface is suppressed. can do.

In the electrolysis system, an injection line for supplying a part of the electrolytic solution from the recycling line to a predetermined place, a seawater supply line for supplying seawater to the adjustment tank, and a part of the seawater in the seawater supply line are injected. You may have a branch line which branches to a line.

According to such a configuration, the flow rate of the injection line can be increased by injecting seawater through the branch line. Thereby, even when the distance of the injection line is long and the precipitated substance is likely to precipitate, deposition of the precipitated substance due to a decrease in the flow rate of the injection line can be prevented.

According to the present invention, it is possible to prevent the deposited substance from being precipitated at the bottom of the adjustment tank.

It is a mimetic diagram showing an outline of an electrolysis system of a first embodiment of the present invention. It is a longitudinal section showing an outline of an electrolytic cell which constitutes an electrolysis device of a first embodiment of the present invention. It is the schematic diagram seen from the upper direction of the adjustment tank of 1st embodiment of this invention. It is a schematic diagram which shows the outline | summary of the electrolysis system of 2nd embodiment of this invention. It is a schematic diagram which shows the outline | summary of the electrolysis system of 3rd embodiment of this invention. It is a schematic diagram which shows the outline | summary of the electrolysis system of 4th embodiment of this invention. It is a perspective view of the adjustment tank of the electrolysis system of a fifth embodiment of the present invention.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram showing an outline of an electrolysis system 1 according to the present embodiment. The electrolytic system 1 of the present embodiment is a system that generates an electrolytic solution E containing sodium hypochlorite (chlorine, sodium hypochlorite) by electrolyzing a liquid to be treated such as seawater W.

The electrolysis system 1 of the present embodiment cools a plant such as a thermal power plant, a nuclear power plant, a seawater desalination plant, a chemical plant, and an iron manufacturing plant via an injection line 13 with an electrolyte E containing sodium hypochlorite. Supply to a predetermined place such as piping of equipment, nitrogen treatment tank in which wastewater containing nitrogen is stored.

The electrolysis system 1 includes a seawater supply pump 5 that introduces seawater W necessary for electrolysis, an adjustment tank 3 that temporarily stores an electrolytic solution E (seawater W) that has been treated by the electrolysis apparatus 2, an electrolysis apparatus 2, An annular recycle line 10 that circulates the electrolytic solution E, and an injection line 13 that injects the electrolytic solution E that circulates through the recycle line 10 into, for example, piping of a plant.
The recycling line 10 includes a first recycling line 11 and a second recycling line 12.

The adjustment tank 3 is a bottomed cylindrical tank that stores the electrolyte E circulating in the system and the seawater W supplied from the seawater supply pump 5. The adjustment tank 3 has a fan (not shown) that supplies air to the gas phase of the adjustment tank 3. The shape of the adjustment tank 3 is not limited to the bottomed cylindrical shape, and may be a rectangular parallelepiped shape.

The electrolyzer 2 is an apparatus that electrolyzes the seawater W in the middle of the recycle line 10. The electrolysis device 2 includes an electrolytic cell 6 and a DC power supply device 7 (rectifier). The electrolysis apparatus 2 is an apparatus that generates sodium hypochlorite by electrolyzing seawater W.
As shown in FIG. 2, the electrolytic cell 6 includes an electrode support box 26, a terminal plate 28, and a plurality of electrodes 30. The electrolytic cell 6 contains an anode A and a cathode K as electrodes 30. The electrolytic cell 6 has an inlet 15 for introducing the electrolytic solution E into the electrolytic cell 6 and an outlet 16 for discharging the electrolytic solution E from the electrolytic cell 6.

The terminal plate 28 has a role of supplying a current from the outside of the electrolytic cell 6 to the electrode 30 supported in the electrode support box 26. One terminal board 28 is disposed at each end of the electrode support box 26.
The electrode 30 has a plate shape, and a plurality of electrodes 30 are fixedly supported on the support bar 26a of the electrode support box 26 in an arrayed state. In the present embodiment, three types of electrodes 30, a bipolar electrode plate 31, an anode plate 32, and a cathode plate 33 are used as the electrode 30.

The bipolar electrode plate 31 has a structure in which a titanium substrate as an electrode substrate is divided into two, one of which is an anode A and the other is a cathode K. That is, the bipolar electrode plate 31 has a half region at one end side as an anode A whose surface is coated with a coating material containing iridium oxide (iridium oxide-based coating material), and a half region at the other end side. Is a cathode K whose surface is not coated with the above-mentioned iridium oxide-based coating material.

The anode plate 32 has a structure in which the entire surface of the titanium substrate is coated with an iridium oxide-based coating material. The entire anode plate 32 functions as the anode A during electrolysis. As the cathode plate 33, a titanium substrate on which no coating is applied is employed. The entire cathode plate 33 functions as a cathode K during electrolysis.

Here, the arrangement structure of the three types of electrodes 30 in the electrode support box 26 will be described. The bipolar electrode plate 31, the anode plate 32, and the cathode plate 33 are each fixedly supported by a support bar 26a in the electrode support box 26.
As shown in FIG. 2, among the electrodes 30, the plurality of bipolar electrode plates 31 are arranged with the anode A facing the liquid inlet side and the cathode K facing the liquid outlet side. The plurality of bipolar electrode plates 31 are arranged so that the extending direction of the bipolar electrode plates 31 is along the flow direction of the seawater W. The plurality of bipolar electrode plates 31 constitutes the electrode group M by being arranged in series at intervals in the flow direction of the seawater W. A plurality of electrode groups M are provided at intervals so as to be parallel to each other. The plurality of electrode groups M are provided in parallel with each other.

The DC power supply device 7 is a device that supplies a current for electrolysis of seawater W. As the DC power supply device 7, for example, a configuration including a DC power supply and a constant current control circuit can be employed. The DC power source is a power source that outputs DC power, and may be configured to rectify and output AC power output from the AC power source to DC, for example.

The seawater supply pump 5 and the adjustment tank 3 are connected by a seawater supply line 4. The seawater supply line 4 may be provided with a strainer for preventing entry of foreign substances that hinder electrolysis.
The adjustment tank 3 and the inlet 15 of the electrolytic cell 6 are connected by a first recycle line 11. That is, a part of the electrolytic solution E (reserved liquid R) in the adjustment tank 3 is introduced into the electrolytic tank 6 through the first recycling line 11. An injection pump 17 is provided on the first recycle line 11. The injection pump 17 is a pump that supplies the circulating electrolyte solution E to the adjustment tank 3 and transfers the electrolyte solution E to the injection line 13.

The second recycling line 12 is a line that connects the outlet 16 of the electrolytic cell 6 and the adjustment tank 3. That is, the electrolytic solution E generated in the electrolysis apparatus 2 is introduced into the adjustment tank 3 through the second recycle line 12.
An injection nozzle (not shown) is provided at the downstream end of the injection line 13. By providing the injection nozzle, sodium hypochlorite produced by the electrolysis apparatus 2 can be efficiently diffused into the plant piping.

A discharge pipe 18 that discharges the electrolytic solution E into the adjustment tank 3 is provided at a connection portion between the second recycling line 12 and the adjustment tank 3 of the present embodiment. In other words, the electrolytic solution E circulated through the recycle line 10 and supplied to the adjustment tank 3 is discharged to the stored liquid R stored in the adjustment tank 3 via the discharge pipe 18.
The discharge pipe 18 is a tubular member and is disposed so as to generate a swirling flow in the stored liquid R in the adjustment tank 3. As shown in FIG. 3, the discharge pipe 18 is oriented so that the electrolyte E discharged from above is discharged along the outer peripheral surface 3 a of the adjustment tank 3. In other words, the discharge pipe 18 is arranged (tangentially) so that the extending direction of the discharge pipe 18 is along the tangential direction of the outer peripheral surface 3 a of the adjustment tank 3.

Next, the operation of the electrolysis system 1 of the present embodiment will be described.
First, seawater W is introduced into the adjustment tank 3 through the seawater supply line 4. Seawater W is introduced into the first recycling line 11, the electrolytic cell 6, and the second recycling line 12, and circulates. In this step, the seawater W is returned to the electrolytic cell 6 via the first recycle line 11. Thereby, the electrode 30 (the cathode K and the anode A) in the electrolytic cell 6 is immersed in the seawater W.
Further, the electrolytic solution E circulated from the second recycling line 12 is discharged to the stored liquid R in the adjustment tank 3 through the discharge pipe 18.

Electrolysis is performed on the seawater W as a current flows through the seawater W between the electrodes 30.
That is, in the anode A, as shown in the following formula (1), electrons e are taken from chloride ions in the seawater W, oxidation occurs, and chlorine is generated.
2Cl ⁻ → Cl ₂ + 2e ⁻ (1)
On the other hand, at the cathode K, as shown in the following formula (2), electrons are given to the water in the seawater W to cause reduction, and hydroxide ions and hydrogen gas are generated.
2H ₂ O + 2e ⁻ → 2OH ⁻ + H ₂ (2)

Further, as shown in the following formula (3), the hydroxide ions generated at the cathode K react with sodium ions in the seawater W to generate sodium hydroxide.
2Na ⁺ + 2OH ⁻ → 2NaOH (3)

Furthermore, as shown in the formula (4), sodium hydroxide and chlorine react to produce hypochlorous acid, sodium chloride, and water.
Cl ₂ + 2NaOH → NaClO + NaCl + H ₂ O (4)
Thus, based on the electrolysis of the seawater W, sodium hypochlorite having an inhibitory effect on the adhesion of marine products is generated.
The concentration of sodium hypochlorite is preferably 500 to 5,000 ppm because the chloride ion concentration of seawater W is increased to 30,000 to 40,000 mg / l.

Here, in general, the electrolyte solution E returned to the seawater W or the electrolytic cell 6 includes scale components (fine particles that precipitate scales, scale lumps, fine particles that function as seed crystals that precipitate scales), for example, magnesium ions (Mg ²⁺ ), calcium ions (Ca ²⁺ ), manganese ions (Mn ²⁺ ), and silicic acid ([SiO _X (OH) _4-2X ] _n ).

In general, the anode A coated with the iridium oxide-based coating material is attached with a manganese scale, which is a deposit due to manganese ions contained in the seawater W during electrolysis. As the manganese scale adheres, the anode A is consumed, and the catalytic activity on the surface of the electrode 30 is reduced, so that the chlorine generation efficiency is reduced. A scale caused by magnesium or calcium contained in the seawater W adheres to the cathode K, and the consumption of the electrode 30 also proceeds by the scale.

In the electrolysis system 1 of the present embodiment, the electrolyte E circulating from the second recycle line 12 generates a swirling flow in the stored liquid R through the discharge pipe 18. Thereby, precipitation of the scale contained in the electrolyte solution E and the stored solution R is prevented. That is, the discharge pipe 18 functions as a prevention means for preventing sedimentation of scale.

In the electrolysis system 1 of the present embodiment, the scale components and scales contained in the electrolyte solution E are desorbed along with the scale generated on the electrode 30 surface. That is, the scale fine particles contained in the electrolyte solution E that has flowed in function as seed crystals and desorb the scale on the electrode 30 surface. Thereby, accumulation of scale on the surface of the electrode 30 is suppressed.

Further, the pH (hydrogen ion index) of the electrolytic solution E increases with electrolysis and becomes highly alkaline, so that the scale component is deposited as a scale such as calcium hydroxide or magnesium hydroxide.
In the electrolysis system 1 of this embodiment, the scale in which the scale such as calcium carbonate and magnesium hydroxide is separated from the electrode 30 and floats in the liquid by returning the electrolytic solution E containing the scale component to the electrolytic cell 6. Precipitates on the surface of the component. Thereby, precipitation of the scale on the cathode K surface can be prevented.

The electrolyzed seawater W flows out from the outlet 16 of the electrolytic cell 6 together with hydrogen gas as the electrolytic solution E, and is stored in the adjustment tank 3 through the second recycle line 12. In the adjustment tank 3, hydrogen gas generated by the electrolytic reaction accumulates on the gas phase side. Hydrogen gas is exhausted after being diluted to below the explosion limit by air supplied to the gas phase.
The stored liquid R including the electrolytic solution E stored in the adjustment tank 3 is introduced into the injection line 13 by the injection pump 17 and then injected into a predetermined place such as a piping of the cooling facility. That is, the electrolytic solution E containing sodium hypochlorite is injected into a predetermined place through the injection line 13 by operating the injection pump 17 pump.

According to the embodiment, by injecting the electrolytic solution E containing sodium hypochlorite into a predetermined place such as a piping of a cooling facility through the injection line 13, it is possible to effectively suppress the attachment of marine organisms. Can do.
Moreover, the nitrogen component contained in the nitrogen containing waste_water | drain discharged | emitted from a plant via the injection line 13 can be removed. That is, the nitrogen component contained in the waste water can be removed by injecting the electrolytic solution E containing sodium hypochlorite into the nitrogen treatment tank in which the nitrogen-containing waste water is stored.

Further, as the electrolytic solution E is discharged to the adjustment tank 3 through the discharge pipe 18, a swirling flow is generated in the stored liquid R in the adjustment tank 3. Thereby, it can prevent that a scale settles in the bottom part of the adjustment tank 3. FIG. That is, the scale continues to float in the stored liquid R by the swirling flow. Thereby, it becomes difficult for a scale to collect in the bottom part of the adjustment tank 3, the load of scale removal construction is reduced, and maintainability can be improved.

In addition, when the stored liquid R is returned to the electrolytic cell 6, the scale component contained in the stored liquid R is detached along with the scale generated on the surface of the electrode 30. Thereby, accumulation of scale on the surface of the electrode 30 can be prevented. That is, the scale fine particles contained in the storage liquid R returned to the electrolytic cell 6 function as seed crystals, so that electrode deterioration can be moderated.
Further, by preventing the accumulation of scale on the surface of the electrode 30, an increase in electrolytic voltage (deterioration of power consumption) can be suppressed.
Moreover, the spark by the short circuit of electrodes 30 can be prevented and safety can be improved.

In addition, the surface of the scale fine particles (seed crystals) floating in the liquid away from the electrode 30 surface, such as calcium carbonate and magnesium hydroxide, which are precipitated when the pH of the electrolytic solution E increases with electrolysis By precipitating at, it is possible to prevent the scale from being deposited on the cathode surface.

Further, even in the anode A formed by coating titanium with a coating material containing iridium oxide that easily adheres manganese scale during electrolysis, scale growth on the surface of the electrode 30 can be suppressed. .

Further, it is possible to prevent electrode degradation caused by oxidation of pollutants (NH ₃ , COD, etc.) contained in the seawater W by sodium hypochlorite and oxidation of the pollutants by the electrode 30 (anode A). Can do.

In addition, in the said embodiment, although it was set as the structure by which the electrolyte solution E is discharged by the discharge pipe 18, it does not restrict to this. For example, the seawater W supplied via the seawater supply pump 5 may be discharged by the discharge pipe 18. That is, it is only necessary that a swirl flow can be generated in the stored liquid R stored in the adjustment tank 3.

(Second embodiment)
Hereinafter, the electrolysis system 1B of 2nd embodiment of this invention is demonstrated based on drawing. In the present embodiment, differences from the first embodiment described above will be mainly described, and description of similar parts will be omitted.
As shown in FIG. 4, in the adjustment tank 3 of the electrolysis system 1B of this embodiment, mechanical agitation that mechanically agitates the stored liquid R in the adjustment tank 3 as an alternative to the discharge pipe 18 of the first embodiment. A device 20 is provided. The mechanical stirrer 20 is a prevention means for preventing sedimentation of scale, like the discharge pipe 18.

The mechanical stirring device 20 includes a motor 21 having an output shaft and a screw 22 provided on the output shaft of the motor 21.
By operating the mechanical stirring device 20, the stored liquid R stored in the adjustment tank 3 is forcibly stirred. In other words, scale components (fine particles) and scales contained in the electrolytic solution E stored in the adjustment tank 3 are not precipitated by riding on the flow formed by the mechanical stirring device 20.

According to the above embodiment, by using the mechanical stirring device 20, the stored liquid R stored in the adjustment tank 3 is forcibly stirred. Thereby, it can prevent that a scale settles in the bottom part of the adjustment tank 3. FIG.

(Third embodiment)
Hereinafter, an electrolytic system 1C according to a third embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 5, the adjustment tank 3 of the electrolysis system 1C of the present embodiment is provided with a pneumatic stirring device 34 as an alternative to the discharge pipe 18 of the first embodiment. The pneumatic stirrer 34 includes a wall member 36 positioned in the adjustment tank 3 and an air supply unit 35 that supplies air to the stored liquid R.

The wall member 36 is a plate-like member that extends in the vertical direction of the adjustment tank 3 and divides the inside of the adjustment tank 3. The wall member 36 is sized such that a predetermined gap is generated between the lower end of the wall member 36 and the bottom of the adjustment tank 3 and between the upper end of the wall member 36 and the liquid level of the stored liquid R.
The air supply unit 35 is a device that supplies air to the lower part of one space partitioned by the wall member 36. The air supply unit 35 includes a blower (not shown) that pressurizes air to form pressurized air, and a nozzle 37 that supplies the pressurized air to the storage liquid R.

The nozzle 37 is in the stored liquid R and supplies air to the lower part of one space partitioned by the wall member 36. When pressurized air is supplied through the nozzle 37, one space becomes a rising portion 38 where the air rises from the bottom. The pressurized air rises and escapes from the top. Therefore, there is almost no air in the other space (the descending portion 39). The stored liquid R in the adjustment tank 3 circulates between the ascending part 38 and the descending part 39 due to the difference in density of the stored liquid R between the ascending part 38 and the descending part 39.

According to the above embodiment, the agitation / dispersion effect of the stored liquid R can be obtained by the aeration power of air.
In addition, by using air and increasing the dissolved oxygen (Dissolved Oxygen, DO) concentration, the reaction promotes the oxidation of manganese ions and silicic acid to manganese dioxide (MnO ₂ ) and silicon dioxide (SiO ₂ ). It is possible to prevent the component from depositing on the surface of the electrode 30 (anode A).

In addition, aeration with air is performed to increase the dissolved carbon dioxide (CO ₃ ²⁺ ) concentration in the electrolytic solution E (for example, pH 8.5), promote the reaction in which calcium ions are precipitated as calcium carbonate, and the scale component is the electrode 30 ( Scale deposition on the cathode K) surface can be prevented.

(Fourth embodiment)
Hereinafter, the electrolysis system 1D of 4th embodiment of this invention is demonstrated based on drawing.
As shown in FIG. 6, between the seawater supply line 4 and the injection line 13 of the electrolysis system 1 </ b> D of this embodiment, the seawater W supplied by the seawater supply pump 5 is directly introduced into the injection line 13. A branch line 41 (backup line) is provided. That is, the electrolysis system 1 of this embodiment can branch directly to the injection line 13 without sending the seawater W flowing through the seawater supply line 4 to the adjustment tank 3.
On the branch line 41, a seawater branch flow rate adjustment valve 42 for adjusting the flow rate of the seawater W flowing through the branch line 41 is provided.

According to the above embodiment, by injecting the seawater W through the branch line 41, the flow rate of the injection line 13 can be increased. Thereby, even when the distance of the injection line 13 is long and the pH of the electrolytic solution changes and the scale is likely to precipitate, the deposition of the scale can be suppressed. That is, scale accumulation due to a decrease in the flow rate of the injection line 13 can be prevented.
The flow rate of the seawater W injected through the branch line 41 can be adjusted as appropriate by operating the seawater branch flow rate adjustment valve 42.

(Fifth embodiment)
Hereinafter, an electrolysis system according to a fifth embodiment of the present invention will be described with reference to the drawings. In the present embodiment, differences from the first embodiment described above will be mainly described, and description of similar parts will be omitted.
As shown in FIG. 7, a columnar structure 24 having a columnar shape extending in the vertical direction is disposed in the center portion viewed from above the adjustment tank 3 of the present embodiment. The columnar structure 24 is disposed so as to be substantially coaxial with the central axis of the bottomed cylindrical adjustment tank 3. It is formed near the center of the swirling flow of the stored liquid R formed by the discharge pipe 18.

According to the said embodiment, it can suppress that a scale lump is formed in the center part of the bottom part 3b of the adjustment tank 3. FIG.
In the electrolysis system of the present embodiment, the columnar structure 24 is installed in order to suppress the formation of a scale lump at the center of the bottom 3b of the adjustment tank 3, but this is not a limitation. For example, an upward convex protrusion may be formed at the center of the bottom 3b of the adjustment tank 3 to suppress the formation of the scale lump.
The shape of the columnar structure 24 is not limited to a cylindrical shape, and may be a prismatic shape. Moreover, it is not necessary to be solid, and a cylindrical shape having a hollow portion inside may be used.

As described above, the embodiments of the present invention have been described in detail with reference to the drawings, but additions, omissions, substitutions, and other modifications can be made without departing from the spirit of the present invention. Further, the present invention is not limited by the embodiments, and is limited only by the scope of the claims.

1, 1B, 1C, 1D Electrolysis system 2 Electrolysis device 3 Adjustment tank 3a Outer peripheral surface 3b Bottom 4 Seawater supply line 5 Seawater supply pump 6 Electrolysis tank 7 DC power supply device 10 Recycle line 11 First recycle line 12 Second recycle line 13 Injection Line 15 Inlet 16 Outlet 17 Infusion pump 18 Discharge pipe (prevention means)
20 Mechanical stirring device (prevention means)
22 Screw 24 Columnar structure 26 Electrode support box 30 Electrode 31 Bipolar electrode plate 32 Anode plate 33 Cathode plate 34 Pneumatic stirrer (prevention means)
35 Air supply part 36 Wall member 37 Nozzle 38 Ascending part 39 Lowering part 41 Branch line 42 Seawater branch flow rate adjusting valve A Anode E Electrolyte K Cathode M Electrode group R Storage liquid W Seawater

Claims

An electrolyzer having an electrolytic cell containing an anode and a cathode as electrodes, and electrolyzing a liquid to be treated;
A regulating tank for temporarily storing the liquid to be treated treated by the electrolyzer;
A recycle line that returns to the electrolytic cell a part of the stored liquid that is stored in the adjustment tank and contains fine particles and a deposited substance formed by the precipitation of the fine particles,
An electrolysis system comprising: means for preventing precipitation of the deposited substance in the adjustment tank.
2. The electrolysis system according to claim 1, wherein the prevention means includes a discharge pipe for discharging liquid to the adjustment tank.
The electrolysis system according to claim 2, wherein the discharge pipe is discharged in a direction in which a swirling flow is generated in the stored liquid stored in the adjustment tank.
The prevention means includes a wall member that extends in the vertical direction of the adjustment tank and divides the inside of the adjustment tank into an ascending part and a descending part, an air supply part that supplies air to the lower part of the ascending part, The electrolysis system according to claim 1, wherein the electrolysis system is a pneumatic stirrer.
2. The electrolysis system according to claim 1, wherein the preventing means is a mechanical stirring device that mechanically stirs the stored liquid in the adjustment tank.
The electrolytic system according to any one of claims 1 to 5, wherein the anode is formed by coating a coating material containing iridium oxide with titanium.
An injection line for supplying a part of the electrolytic solution from the recycling line to a predetermined place;
A seawater supply line for supplying seawater to the adjustment tank;
The electrolysis system according to any one of claims 1 to 6, further comprising a branch line that branches a part of seawater of the seawater supply line to the injection line.