JP2007309052A - Device for preventing fouling of structure and method of preventing fouling - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for preventing fouling and a method of preventing fouling which prevent interference between a current used for preventing fouling and a cathodic protection current prevent the change of the surface state of an electric catalyst covered with an anode-forming member caused by the adhesion and deposit of minute quantities of iron ions, manganese ions or the like contained in the seawater, and can securely and easily prevent the adhesion of aquatic creatures in the sea. <P>SOLUTION: The device for preventing fouling is constituted of the anode-forming member, the electric catalyst, a conductive body, and a direct-current power supply. The anode-forming member is integrally provided on the surface of a component of the structure which is brought into contact with the seawater, through the medium of an insulator. The electric catalyst is constituted of a material which is coated on the surface of the anode-forming member, and is electrochemically active and stable. Then the conductive body is provided so that it is brought into contact with the seawater, and the direct-current power supply is provided with a positive electrode, a negative electrode, an automatic potential control part, and a switching circuit part. The anode-forming member and the positive electrode are electrically connected to each other, and potential between the conductive body and the negative electrode is controlled by the automatic potential control part. Then the energized time and the energization-stopping time of the direct-current power supply is arbitrarily set by the switching circuit part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an antifouling device for a structure, and more particularly to an antifouling device for preventing marine organisms from adhering to the surface of seawater in a structure in contact with seawater.

  In power plants that take seawater as cooling water, animals such as mussels, barnacles, hydro-insects, seaweeds, etc. are attached to the heat transfer tube inlet and outlet tube plates of heat exchangers that are in contact with seawater ( These organisms are collectively called marine organisms). These marine organisms block the tube end of the heat transfer tube to obstruct the passage of the cleaning sponge, or block the inner surface of the heat transfer tube. For this reason, power plants are often forced to stop operations for the removal of these marine organisms. In general, these marine organisms are more likely to adhere to seawater-resistant titanium tube sheets and heat transfer tubes than to copper alloy tube sheets and heat transfer tubes.

  In addition, the water chamber of the heat exchanger is made of a steel base, and its surface is provided with a rubber or resin lining for anticorrosion. The sea that has passed through the strainer net on this lining. The living organism's larvae settle and repeat growth and shedding. This causes the inner surface of the cooling heat transfer tube to be blocked.

  In order to combat these marine organisms and prevent adhesion (hereinafter referred to as antifouling), conventionally, chlorine and chlorine compounds have been introduced into environmental seawater, and antifouling paints containing pigments that produce toxic ions are applied. In addition, toxic ions such as chlorine and copper are generated by means such as seawater electrolysis.

  However, although these conventional methods exhibit an effective antifouling function, the amount and concentration cannot be easily managed in a large amount of seawater environment. Moreover, in order to expect a reliable antifouling effect, it tends to be an excessive chlorine concentration, and as a result, there is a high possibility of causing environmental pollution. Therefore, in recent years, such antifouling measures are in the direction of prohibition or suppression.

  Against this background, a number of researchers and engineers have recently developed pollution-free and non-toxic antifouling measures. For example, silicone-based antifouling paints are non-polluting and non-toxic and have a significant antifouling effect.

  However, silicone-based antifouling paints have a short antifouling effect due to contact with foreign matters such as shells, have high construction costs, and are easy and easy to apply to large-area objects and existing facilities. It has not been put into widespread practical use because it has disadvantages such as lack of means and further, when the flow of seawater is stopped, the antifouling effect is reduced.

  On the other hand, there is another antifouling method. That is, a film of an electrocatalyst mainly composed of a mixed crystal of platinum group metals or a mixture of oxides of these metals is formed on the surface of a titanium heat exchanger or the like in contact with water or seawater. Is an antifouling method that suppresses the deposition of scale due to underwater organisms and trace components in the sea by generating sufficient oxygen without substantially generating chlorine gas (see, for example, Patent Document 1). ).

On the other hand, in Patent Document 2, an electric catalyst is provided on the surface of a titanium tube plate of a heat exchanger without applying heat such as electric resistance heating, and the electric catalyst 3 and the titanium tube plate. Even if the lining etc. provided on the metal member is damaged for some reason by electrically insulating the heat exchanger structural member such as, corrosion of the metal member at the damaged part by adopting the cathodic protection method Can be prevented (see, for example, Patent Document 2).
Japanese Patent Publication No. 01-46595 JP 2000-119884 A

  In the case of titanium heat exchangers, the locations where titanium members are usually used are limited to heat transfer tubes and tube plates. The members such as the water discharge pipe that returns to the sea are made of steel. Since the steel water chamber, the water conduit, and the water discharge pipe are electrically connected to the titanium member, galvanic corrosion is caused when the steel water contact is made, and the steel is severely corroded. Therefore, a rubber or resin lining is applied to the surface of the steel material in contact with seawater to prevent corrosion.

  However, in the method described in Patent Document 1, an electric catalyst is formed on the surface of a titanium structural member in contact with water or seawater to act as an anode, so that the metal of the heat exchanger that is electrically connected to the titanium structural member. The member will also be loaded anodically. Accordingly, when the lining or the like is damaged for some reason, an outflow current is generated from the damaged portion, and the constituent metal members other than the titanium material may be corroded.

  In the unlikely event that the lining is damaged, a method of lowering the steel member to the anticorrosion potential of the steel material, that is, the cathodic protection method is adopted, and the titanium member that is electrically connected to the steel member is cathodic. There is a way to load.

  However, since the technique described in Patent Document 1 uses a titanium member as an anode, a steel water chamber, a water conduit, and a water discharge pipe that are connected to the titanium member are also anodically loaded. Cannot be adopted, and an outflow current is generated from the damaged portion, causing corrosion of the steel member.

  Furthermore, the method described in Patent Document 1 performs an electrical resistance heat treatment for several hours at 350 to 450 ° C. for the catalytic activity of the electrocatalyst. Therefore, there is a concern about damage to the structure due to the generated heat or thermal stress at that time, and the processing cost becomes enormous. Therefore, this method has not been widely put into practical use.

  On the other hand, the technology described in Patent Document 2 relates to an antifouling apparatus that generates oxygen on the seawater-side surface of a structure in contact with seawater and suppresses the formation of marine organisms on the seawater-side surface of the structure. An anode forming member provided on the sea water side surface of the structure in contact with seawater via an insulating adhesive, an electrochemically active and stable electrocatalyst coated on the anode forming member, and seawater It is provided with a conductor installed so as to be in contact with and a DC power source incorporating an automatic potential control unit. The positive electrode of this DC power source is connected to an anode forming member or an electrocatalyst, the negative electrode is connected to a conductor, and the potential between the positive electrode and the negative electrode is such that oxygen is generated while suppressing the generation of chlorine in seawater. Is set.

  According to the invention described in Patent Document 2, since the anode forming member previously coated with the electrocatalyst can be easily adhered to the seawater side surface of the structure at room temperature using an insulating adhesive, thermal stress, etc. There is no concern about damage to the structure. Moreover, since an insulating adhesive is present, for example, electrical insulation with a structure such as a titanium tube sheet is achieved, and even if a lining that protects a metal member that is electrically connected to the titanium tube sheet is damaged for some reason. Further, corrosion of the metal member at the damaged lining can be prevented.

  The antifouling device of Patent Document 2 having such characteristics uses a titanium heat transfer tube having excellent corrosion resistance, such as a titanium heat exchanger, and the cathodic protection method is not required for the heat transfer tube itself. This is a very effective method.

  However, the corrosion resistance of itself, such as an aluminum brass tube, is inferior, and there is a concern that the antifouling effect may be reduced in the case of a heat exchanger that must apply the cathodic protection method to the heat transfer tube itself. That is, since the cathodic protection current flowing into the aluminum brass tube and the antifouling current flowing into the conductor connected to the negative electrode of the antifouling device interfere with each other, the current control of the antifouling device, that is, the potential control Because it becomes difficult.

Explaining based on specific numerical examples, in the antifouling device, for the antifouling necessary for maintaining the potential of the anode forming member attached to the surface of the heat exchanger tube plate at, for example, 1.0 V to generate oxygen If the current density is 0.5 A / m ² , the area of the heat exchanger tube sheet of the 1000 MW class power plant is about 18 m ² , and the current required for antifouling is about 9 A.

  The cathode of the antifouling device is generally provided inside the water chamber, and in that case, the current flows from the tube plate surface to the cathode side, in other words, from the tube plate surface to the water chamber. Will flow.

  On the other hand, when the cathodic protection method is applied to an aluminum brass tube, the brass tube is used as a cathode and an anode is provided at an appropriate location inside the water chamber. In this case, the current value required for anticorrosion is about 6 to 7 times, about 60 A, and this current flows from the anode to the cathode aluminum brass tube, in other words, from the water chamber side to the tube plate surface. Will flow in the direction of the side.

  That is, the current flow by the antifouling device and the current flow by the cathodic protection method flow in opposite directions, with one current value being about 60A and the other current value being about 9A. When the currents of both flow in the sea water in the water in opposition to each other and interfere with each other, it is easy to control the cathodic protection current having a large current value. However, it is difficult to control the relatively small antifouling current, and as a result, the maintenance of the antifouling effect may be hindered.

  In addition, even when using a titanium heat transfer tube that does not need to apply the cathodic protection method to itself because of its excellent corrosion resistance, the cathodic protection method must be applied to water chambers and pipes that are electrically connected to the heat transfer tube. In such a case, a problem due to interference between the antifouling current and the cathodic protection current similar to the above may occur.

  Furthermore, when iron ions or manganese ions contained in trace amounts in seawater adhere to and deposit on the surface of the electrocatalyst coated on the anode forming member, the surface state of the catalyst changes, and the potential of the electrocatalyst itself − There is a concern that the relative relationship between currents breaks down, and a predetermined antifouling current cannot be obtained only by automatic constant potential control, which may hinder the maintenance of the antifouling effect.

  The present invention has been made to solve the above-described problems, and prevents interference between the antifouling current and the cathodic anticorrosive current, and the surface state of the electrocatalyst coated on the anode forming member is seawater. An object of the present invention is to provide an antifouling device and an antifouling method for preventing the adhesion of marine organisms reliably and easily by preventing changes in adhesion and deposition of iron ions and manganese ions contained in trace amounts And

  In order to solve the above-described problems, an antifouling device of the present invention is provided with an anode forming member provided integrally with an insulator on the surface of a structural member that contacts seawater of the structure, and the anode forming member An electrocatalyst composed of an electrochemically active and stable material coated on the surface of the substrate, a conductor placed in contact with seawater, a positive electrode, a negative electrode, an automatic potential controller, and a switch circuit unit. The anode forming member and the positive electrode are electrically connected, the conductor and the negative electrode are electrically connected, and the automatic potential control unit includes the positive electrode and the positive electrode. The potential between the negative electrode and the negative electrode is controlled, and the energization time and energization stop time of the DC power supply are arbitrarily set in the switch circuit unit.

  Further, in order to solve the above-described problem, the antifouling method of the present invention coats the surface of an anode forming member with an electrocatalyst composed of an electrochemically active and stable material, and the anode forming member The DC is provided on the surface of the structural member that contacts the seawater of the structure through an insulator, while the conductor is installed so as to contact the seawater, and includes a positive electrode, a negative electrode, an automatic potential control unit, and a switch circuit unit. The positive electrode of the power source is connected to the anode forming member or the electric catalyst, the negative electrode is connected to the conductor, and the potential difference between the positive electrode and the negative electrode is chlorinated in seawater by the automatic potential controller. Adjusting the potential to generate oxygen while suppressing the occurrence of oxygen, and arbitrarily setting the energization time and energization stop time between the positive electrode and the negative electrode by the DC power source by the switch circuit unit. It is a method for the butterflies.

  According to the antifouling apparatus and the antifouling method of the present invention, interference between the antifouling current and the cathodic anticorrosive current is prevented, and the surface state of the electrocatalyst coated on the anode forming member is contained in a small amount in seawater. We provide an economical antifouling device and antifouling method that can effectively prevent marine organisms from adhering to pollution-free, reliably and easily in order to prevent changes in adhesion and deposition of iron ions and manganese ions. Is possible.

  Preferred embodiments of the antifouling device of the present invention will be described below in detail with reference to the drawings. In addition, about the element common to each Example, the code | symbol same as Example 1 is attached | subjected, and detailed description after Example 2 is abbreviate | omitted.

  In FIG. 1, the block diagram of the antifouling apparatus 10 of Example 1 of this invention is shown. As shown in FIG. 1, the antifouling device 10 for a structure in contact with the seawater 15 generates oxygen on the surface of the titanium heat exchanger 1 in contact with the seawater 15 that is the antifouling target structure on the seawater 15 side. The antifouling device suppresses the formation of marine organisms on the surface of the heat exchanger 1 on the seawater 15 side.

  The heat exchanger 1 has a titanium tube sheet 1a and a plurality of titanium heat transfer tubes 1b supported by the titanium tube sheet 1a. As shown in FIG. 1, a water chamber 9 for taking in seawater is provided, and a rubber lining 11 is formed on the inner surface in contact with the seawater 15 side.

  An antifouling device 10 including an electrical catalyst 3, a titanium sheet 4, and an insulating sheet 5 is provided for the heat exchanger 1. The antifouling device 10 has the following configuration. That is, the insulating sheet 5 which is a sheet material having insulating properties and seawater resistance is attached to substantially the entire surface of the tube sheet 1a on the seawater 15 side via the insulating adhesive 6, and further, the insulating sheet On the upper surface of 5, a titanium sheet 4, which is a panel-like anode forming member having a thickness of 0.1 to 0.3 mm, is provided on substantially the entire surface with an insulating adhesive 6. As shown in FIG. 1, the insulating sheet 5 and the titanium sheet 4 have a plurality of openings corresponding to the tube diameters of the plurality of titanium heat transfer tubes 1 b.

  An electric catalyst 3 is provided on the upper surface side of the titanium sheet 4 in FIG. This electric catalyst 3 is coated on the surface of the titanium sheet 4 in advance by a catalyst coating treatment, and is heat-activated by performing heat treatment at 350 to 450 ° C. for several hours by electric resistance heating or the like. Provided as a chemically active and stable catalyst. Specifically, the material of the electrocatalyst 3 is preferably a single body, a mixed crystal body, or a composite body made of a platinum-based metal, a platinum-based metal oxide, or an oxide of cobalt or manganese.

  On the other hand, the conductor 8 protrudes from the lining 11 provided integrally on the surface of the water chamber 9 on the seawater 15 side toward the seawater 15 side. Similarly, the collation electrode 12 is provided so as to protrude toward the seawater 15 side.

  This antifouling device 10 is connected to a DC power supply 7 provided outside, and a positive electrode 7 a of the DC power supply 7 is electrically connected to the titanium sheet 4, while a negative electrode is connected to the conductor 8. Further, the verification electrode 7r is connected to the verification electrode 12. The DC power source 7 includes an automatic potential control unit 7c, and the potential of the energizing circuit formed between the positive electrode 7a and the negative electrode 7b generates oxygen while suppressing generation of chlorine in the seawater 15. Set to potential. Specifically, this potential is set to a value lower than the SCE reference potential 1.20 V, which is a potential at which chlorine is generated by seawater electrolysis, and higher than the oxygen generation potential 0.52 V in standard seawater.

  Further, the DC power supply 7 has a built-in switch circuit portion 7d, and the energization time and energization stop time between the positive electrode 7a and the negative electrode 7b can be arbitrarily set.

  The reference electrode 12 of the antifouling device 10 is for monitoring the potential of the titanium sheet 4, and the detected voltage by the reference electrode 12 is used as control data for the automatic potential control unit 7 c.

  Next, the operation of the antifouling device 10 of this embodiment will be described.

  The potential of the titanium sheet 4 (anode forming member) functioning as the anode, that is, the potential of the electric catalyst 3 is maintained in the range of 0.52 V to 1.20 V by the DC power source 7. By maintaining this potential, oxygen is generated from the surface of the electric catalyst 3 while suppressing generation of chlorine. This oxygen can effectively prevent the attachment of marine organisms.

  However, at this time, if iron ions or manganese ions contained in a trace amount in seawater adhere to and deposit on the surface of the electrocatalyst 3 covered with the anode forming member (titanium sheet) 4, the surface state of the electrocatalyst 3 Changes, and the relative relationship between the electric potential and current of the electric catalyst 3 itself is broken. Specifically, it is oxidized by the oxygen generated by the iron ions and manganese ions and adheres to the anode surface. Due to the adhesion of the oxide, even if the potential difference between the anode and the cathode is the same, the current density on the anode surface gradually decreases and the amount of oxygen generated decreases. As a result, the predetermined antifouling current cannot be obtained only by the automatic constant potential control by the automatic potential control unit 7c, which hinders the maintenance of the effect of the antifouling device.

  Therefore, in such a case, the switch circuit unit 7d sets the energization stop time between the positive electrode 7a and the negative electrode 7b, and the surface state of the electrocatalyst covered with the titanium sheet 4 serving as the anode forming member is very small in seawater. Prevents changes due to adhesion and deposition of contained iron ions and manganese ions.

FIG. 2 is an example schematically showing the relationship between the current density and the current ratio when the current density is operated at a normal current density of 0.5 A / m ² . In the initial stage of energization, the current is 0.5 A / m ² at the time of energization, but as described above, iron ions and manganese ions adhere to the electrode and the current density decreases. Therefore, after a predetermined energization time, a time for stopping the energization is provided, and then the energization is performed again, whereby each of the ions adhering to the electrode is washed away by the surrounding seawater, and again the first 0.5 A / m ² is restored.

  At this time, while setting the energization stop time by the switch circuit unit 7d within 60 minutes, the energization rate obtained by dividing the energization time by the operation time (that is, the time of one cycle represented by the energization stop time + the energization time) is 25. It is preferable to adjust to% or more.

The reason why it is preferable to adjust the energization rate to 25% or more will be described with reference to Table 1. Table 1 shows the result of immersing the antifouling device 10 having the configuration described in FIG. 1 for a period of time in the sea water after being partially simplified for the experiment.

  As shown in Table 1, the normal stop time was divided into 60 minutes and 30 minutes, and the experiment was carried out by varying the energization rate as a parameter to 50%, 33.3%, 25%, and 14.3%. As a result, marine organisms were not attached only when the energization rate was 25% or more regardless of the energization time, and when less than 25%, adhesion occurred. In the case of Comparative Example 1 in which a metal piece was simply immersed in seawater without providing the antifouling device 10, marine organisms were observed to adhere to the entire surface of the metal piece.

  With such a function, the antifouling device 10 prevents a decrease in the antifouling effect due to the influence of ions contained in a trace amount in seawater by providing an energization stop time.

  Next, a process for manufacturing the antifouling device 10 of this embodiment will be described.

  A panel-shaped titanium sheet 4 previously coated with the electrocatalyst 3 is bonded to the surface of the heat exchanger 1 on the seawater 15 side through an insulating adhesive 6, an insulating sheet 5, and another insulating adhesive 6. To do. Since this manufacturing process can be easily performed at room temperature, there is no fear of damage to the heat exchanger 1 due to thermal stress or the like, and since the insulating adhesive 6 and the insulating sheet 5 are interposed, titanium is used. Electrical insulation between the tube sheet 1a and the like and the panel-like titanium sheet 4 is achieved, and corrosion of the metal member that is electrically connected to the titanium tube sheet 1a can be prevented.

  Further, in the antifouling apparatus 10 of this embodiment, the constituent material of the electrocatalyst 3 is a single body, a mixed crystal body or a composite body made of platinum-based metal, platinum-based metal oxide, or cobalt or manganese oxide. Therefore, activation as an electrode is achieved and the amount of elution of the electrocatalyst 3 into the seawater 15 is minimized. With this configuration, the antifouling device 10 can realize stable oxygen generation for a long time.

  According to the implementation of the present inventors, the anode forming member is covered by adjusting the energization stop time to 60 minutes, the energization time of 20 minutes, and the energization rate of 25% by the switch circuit portion 7d as described above. In addition, since the surface state of the electrocatalyst can be prevented from changing due to adhesion and deposition of iron ions, manganese ions, and the like contained in trace amounts in seawater, the antifouling effect becomes even more remarkable.

  The insulating sheet 5 is an insulating material made of a sheet material of vinyl chloride or fiber reinforced plastic that has excellent seawater resistance and does not deteriorate. Since these materials are also excellent in workability, it is possible to easily process a plurality of holes corresponding to the tube diameter of the heat transfer tube 1b. In particular, the opening process after the titanium sheet 4 and the insulating sheet 5 are previously joined with the insulating adhesive 6 is easy.

  Moreover, as the insulating adhesive 6 used in the antifouling apparatus 10 of the present embodiment, a high-functional elastic adhesive mainly composed of a modified silicone polymer and an epoxy resin is preferable. Since the insulating adhesive 6 using such a material has a stable adhesive strength even at a temperature of 0 to 500 ° C., it can obtain a stable and durable adhesive strength, and the material itself has a high elasticity. As a result, the resistance against collisions of foreign matter and the like can be increased, and safety is also improved.

  The anode potential is a function of the current density on the anode surface. The higher the current density, the higher the potential, and the proportion of oxygen generated increases in proportion to this. That is, if the potential of the anode is kept closer to 1.20 V, an effective pollution control device that is pollution-free and environmentally friendly can be realized without generating chlorine and without killing marine organisms.

  However, if the current density of the anode is too high, the amount of the electrocatalyst 3 eluted into the sea increases, so the deterioration of the electrocatalyst 3 is accelerated and the antifouling current value becomes higher than necessary. Since the operating cost of the soiling apparatus 10 becomes high, it is not a good idea.

  Thus, the switch circuit unit 7d adjusts the energization stop time to 60 minutes, the energization time to 20 minutes, and the energization rate to 25%. Under such operating conditions, the elution amount of the electrocatalyst 3 can be minimized and the antifouling apparatus can be operated economically.

  In FIG. 3, the structure of the antifouling | stain-proof apparatus 20 of Example 2 of this invention is shown.

  As shown in FIG. 3, the antifouling device 20 of the present embodiment has substantially the same configuration as the antifouling device 10 of the first embodiment shown in FIG. In this configuration, the titanium sheet 4 is attached to the surface of the exchanger 1 on the seawater 15 side only through the insulating adhesive 6.

  If the insulating action by the insulating adhesive 6 is sufficient as in the antifouling device 20 of this embodiment, the titanium tube plate 1a and the like and the panel-like titanium sheet 4 can be provided without providing the insulating sheet 5. Since electrical insulation is achieved, corrosion of the metal member that is electrically connected to the titanium tube sheet 1a and the like can be prevented.

  Since this antifouling device 20 has a more simplified configuration than the antifouling device 10 of Example 1, it has the same antifouling performance while having the merit that the construction cost is suppressed low. .

  In FIG. 4, it is explanatory drawing which shows the structure of the antifouling apparatus 30 of Example 3 of this invention. As shown in FIG. 4, a heat exchanger 31 in which the antifouling device 30 of this embodiment is constructed includes a plurality of aluminum brass heat transfer tubes 31b and naval brass tubes that support the plurality of heat transfer tubes 31b. And a plate 31a.

  The heat transfer tube 31b made of aluminum brass is inferior in corrosion resistance to seawater compared to the titanium tube plate 1a and the heat transfer tube 1b of the heat exchanger 1 in which the antifouling device 20 of Example 1 is installed. Corrosion protection is provided. As this cathodic protection method, an external power source method or a sacrificial anode method can be applied.

  The antifouling device 30 of the present embodiment shown in FIG. 4 includes an external DC power supply device 35 and a cathodic protection electrode 36 as means for supplying a cathodic protection current. The antifouling device 30 shown in FIG. 4 shows an example using an external power supply system, in which a heat transfer tube 31b and a cathodic protection electrode 36 are connected via an external direct current power supply 35 for cathodic protection to prevent cathodic protection. A cathodic protection current is supplied from the edible electrode 36 to the heat transfer tube 31b. Note that a cathodic protection current may be supplied to the heat transfer tube 31b by a sacrificial anode method.

  According to the antifouling device 30 of the third embodiment, the heat transfer tube 31b is connected to the negative electrode 7b of the DC power source 7, and the inner peripheral surface of the heat transfer tube 31b is used as a cathode for seawater electrolysis. Current and cathodic protection current flow in the same direction. Therefore, since the interference between the antifouling current and the cathodic anticorrosion current can be reduced, the control of the antifouling current, that is, the potential can be more reliably and easily performed.

  Further, in the antifouling apparatus 30 of the present embodiment, as shown in FIG. 4, the reference electrode 12 is provided so as to protrude in the vicinity of the titanium sheet 4 that is an anode forming member, so that the potential of the titanium sheet 4 can be monitored with high accuracy. It is possible to more reliably control the potential.

  In FIG. 5, the antifouling apparatus 40 of Example 4 is shown. In the antifouling device 40, similarly to the antifouling device 30 of the third embodiment, the tube plate 31a and the heat transfer tube 31b are formed of naval brass and aluminum brass, respectively. In this configuration, the insulating sheet 5 is not provided and the titanium sheet is provided using the insulating action of the insulating adhesive 6.

  That is, the titanium sheet 4 is provided on the tube plate 31a without the insulating sheet 5 and only through the insulating adhesive 6 having sufficient insulation. The antifouling device 40 obtains the antifouling device 40 having a simpler structure while obtaining substantially the same antifouling effect as the antifouling device 30 shown in FIG. 3 due to sufficient insulation of the insulating adhesive 6. Therefore, the construction cost can be suppressed.

  In FIG. 6, the structure of the antifouling apparatus 50 of Example 5 is shown. This antifouling device 50 shows another configuration example of the position where the verification electrode 12 is provided.

  That is, the verification electrode 12 is provided inside the heat transfer tube 31b and is installed so as to protrude from the tube end of the heat transfer tube 31b to the seawater 15 side. In the case of such a configuration as the antifouling device 50, the reference electrode 12 can be disposed closer to the titanium sheet 4, that is, the anode forming member, so that the potential monitoring and control can be performed more accurately. Is possible.

  In FIG. 7, the structure of the antifouling apparatus 60 of Example 6 is shown. The antifouling device 60 uses not only the surface of the tube plate 31a but also the surface of the lining 11 provided on the wall of the water chamber 9 on the inflow side and the discharge side of the seawater 15 as an antifouling target site. A coated titanium sheet 4 is provided.

  As such a configuration, oxygen may be generated from the surface of the electrocatalyst 3 while suppressing generation of chlorine. In the case of the antifouling device 60 having the above-described configuration, the adhesive 16 that bonds the lining 11 and the titanium sheet 4 may not have insulating properties. The antifouling device 60 can be expected to have an effective antifouling effect not only on the surface of the tube plate 31 a but also on the surface of the lining 11.

  In addition, in the antifouling apparatus of each Example shown in FIG. 4 thru | or 7, although the example which used the naval brass as a material of the tube sheet 31a and used the aluminum brass as the material of the heat exchanger tube 31b was shown, it is a combination of materials. Is not limited to the above materials. For example, aluminum bronze may be used as the material of the tube plate 31a, and aluminum brass may be used as the material of the heat transfer tube 31b. In addition to this, Naval brass is used as the material of the tube plate 31a, Super stainless steel is used as the material of the heat transfer tube 31b, Aluminum bronze is used as the material of the tube plate 31a, Super stainless steel is used as the material of the heat transfer tube 31b, The material of the tube plate 31a and the heat transfer tube 31b may be super stainless steel.

  Further, for a heat exchanger in which the material is titanium, such as the tube plate 1a and the heat transfer tube 1b, as in the heat exchanger 1 of FIG. 1, the titanium itself is excellent in corrosion resistance. Although it is not necessary to apply the cathodic protection method to the heat tube, the cathodic protection method may be applied to other components of the heat exchanger connected to the tube plate and the heat transfer tube, for example, a water chamber or piping. Also in this case, since the antifouling current and the cathodic protection current may interfere with each other, it is possible to further ensure the anticorrosion of these components by applying the cathodic protection method.

  In FIG. 8, the structure of the antifouling apparatus 70 of Example 7 is shown. As shown in FIG. 8, this antifouling device 70 generates oxygen on the surface of the seawater 15 side using the lining 11 provided in the water chamber 9 on the inflow side and the discharge side of the seawater 15 as a structure to be antifouled. The antifouling device suppresses the formation of marine organisms on the surface of the water chamber 9.

  In the antifouling apparatus 70 of the present embodiment, a titanium sheet 4 (anode forming member) having a thickness of 0.1 to 0.3 mm is attached to the surface of the lining 11 on the seawater 15 side via an adhesive 16. . In the case of the antifouling device 70, the adhesive 16 does not need to have insulating properties. In addition, about the other structure in the antifouling apparatus 70, it is the same structure as the antifouling apparatus 20 of 1st Example shown in FIG.

  According to the antifouling apparatus 70 of the present embodiment, oxygen is generated from the surface of the electric catalyst 3 provided on the lining 11 that is an insulator while the generation of chlorine is suppressed. Therefore, even on the surface of the lining 11 that is an insulator on the seawater 15 side, it is possible to prevent adhesion of marine organisms. This antifouling device 70 shows a configuration for obtaining an antifouling effect on the water chamber 9 when the cathodic protection method is not applied.

  FIG. 9 shows the configuration of the antifouling device 80 of the eighth embodiment. As shown in FIG. 9, the antifouling apparatus 80 generates oxygen on the surface of the seawater 15 side in the cooling seawater intake concrete intake channel 81 that is a structure to be antifouled, thereby causing marine organisms to settle. It is to suppress.

  The antifouling device 80 has a structure in which the conductor 8 is formed as a reinforcing bar 82 (part of which is in contact with the seawater 15) of a cooling water intake concrete intake channel 81, and the other device configuration is shown in FIG. The configuration is the same as the antifouling device 70 shown.

  According to the antifouling apparatus 80 of the present embodiment, generation of chlorine is being suppressed from the surface of the electrical catalyst 3 provided on the surface of the seawater 15 side of the cooling water intake concrete intake 81 that is an insulator. Oxygen is generated. Accordingly, it is possible to prevent marine organisms from adhering to the surface of the seawater 15 side of the cooling water intake concrete intake 81.

  In the first to eighth embodiments described above, the titanium sheet 4 is provided not only on the lining 11 and the cooling water intake concrete intake channel 81 but also on various insulator parts such as resin members. be able to.

  Moreover, in the first to eighth embodiments described above, an example in which a member constituting a heat exchanger is applied as an antifouling object has been shown. However, the scope of the present invention is the above object. It is not limited and can be applied to structures used in contact with all kinds of seawater where interference between the antifouling current and the cathodic protection current becomes a problem. An excellent effect of antifouling can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram of the antifouling apparatus of Example 1 which concerns on this invention. The figure showing the time change of the current density of the anode which concerns on this invention. The block diagram of the antifouling apparatus of Example 2 which concerns on this invention. The block diagram of the pollution protection apparatus of Example 3 which concerns on this invention. The block diagram of the antifouling apparatus of Example 4 which concerns on this invention. The block diagram of the pollution protection apparatus of Example 5 which concerns on this invention. The block diagram of the pollution protection apparatus of Example 6 which concerns on this invention. The block diagram of the pollution protection apparatus of Example 7 which concerns on this invention. The block diagram of the pollution protection apparatus of Example 8 which concerns on this invention.

Explanation of symbols

1 Heat exchanger 1a Tube sheet (antifouling target part)
1b Heat transfer tube 3 Electrocatalyst 4 Titanium sheet 5 Insulating sheet 6 Insulating adhesive 7 External DC power source 7a Positive electrode 7b Negative electrode 7c Automatic potential control unit 7d Switch circuit unit 7r Reference electrode 8 Conductor 9 Water chamber 10 Antifouling device 11 Lining 12 collation electrode 15 seawater 16 adhesive 20 antifouling device 30 antifouling device 31a tube plate 32b heat transfer tube 35 external direct current power supply device 36 for cathodic protection anticorrosive electrode 40 antifouling device 50 antifouling device 60 antifouling device 70 antifouling Antifouling device 80 Antifouling device 81 Cooling seawater intake concrete intake 82 Reinforcing bar

Claims (11)

Constructed by an anode forming member provided integrally with an insulator on the surface of a structural member that contacts seawater of the structure, and an electrochemically active and stable material coated on the surface of the anode forming member And a positive electrode, a negative electrode, an automatic potential control unit, and a DC circuit including a switch circuit unit, and the anode forming member and the positive electrode. And electrically connecting the conductor and the negative electrode, controlling the potential between the positive electrode and the negative electrode by the automatic potential control unit, and at the switch circuit unit An antifouling device, wherein an energization time and an energization stop time of the DC power supply are arbitrarily set. The dyeing-proof device according to claim 1, wherein the insulator is made of a sheet material having seawater resistance. The dyeing-proof apparatus according to claim 1, wherein the insulator is formed of an insulating adhesive for fixing the anode forming member to the structure. 2. The antifouling apparatus according to claim 1, wherein a rubber-based or resin-based lining is applied to a surface of a structural member that contacts seawater of the structure. 2. The antifouling apparatus according to claim 1, wherein the structure is a concrete structure, and the conductor is a reinforcing bar for the concrete structure. 2. The antifouling apparatus according to claim 1, further comprising means for supplying a cathodic protection current to a component made of a metal material that contacts seawater among the components of the structure. The structure is a heat exchanger provided with a plurality of metal heat transfer tubes and a tube plate made of a metal material that supports the plurality of heat transfer tubes, and is electrically connected to the heat transfer tubes or the heat transfer tubes A means for supplying a cathodic protection current to a component that contacts the seawater formed is provided, and the inner surface of the heat transfer tube is used as an electrode for generating oxygen to prevent contamination. Antifouling device. The antifouling apparatus according to claim 7, wherein the structural member that contacts seawater of the structure is a tube plate of the heat exchanger. The structural member in contact with seawater of the structure is a wall body constituting a water chamber of a heat exchanger, a rubber or resin lining is applied to the inner surface of the wall body, and the anode forming member is provided on the lining. 8. The antifouling device according to claim 7, wherein the antifouling device is provided. An electrocatalyst composed of an electrochemically active and stable material is coated on the surface of the anode forming member, and this anode forming member is provided on the surface of the structural member in contact with seawater of the structure via an insulator. On the other hand, the conductor is installed so as to be in contact with seawater, and the positive electrode of the DC power source including the positive electrode, the negative electrode, the automatic potential control unit, and the switch circuit unit is connected to the anode forming member or the electric catalyst, The negative electrode is connected to the conductor, and the automatic potential control unit adjusts the potential difference between the positive electrode and the negative electrode to a potential for generating oxygen while suppressing generation of chlorine in seawater, and the switch circuit An antifouling method, wherein an energization time and an energization stop time between the positive electrode and the negative electrode by the DC power source are arbitrarily set by a unit. The antifouling method according to claim 10, wherein the energization stop time is set within 60 minutes by the switch circuit unit, and the energization rate obtained by dividing the energization time by the operation time is set to 25% or more.

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