JP2007186933A - Anti-fouling and corrosion protection device of structure contacting with seawater and anti-fouling and corrosion-proofing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anti-fouling and corrosion protection device of a structure contacting with seawater and capable of continuing the effect of anti-fouling and corrosion protection even if it is operated for a long period of time and continuing also the durability of the device for a long period of time and an anti-fouling and corrosion proofing method. <P>SOLUTION: In the anti-fouling and corrosion protection contacting with seawater and protecting ocean creatures from being adhered to the wall surface of the structure by supplying a current based on a power connection pattern intermittently repeating one cycle setting a predetermined voltage and an applied time in a titanium membrane formed on the wall surface of the structure contacting with seawater through an insulating membrane, a potential sensor measuring the surface potential of the titanium membrane is provided, and the power connection pattern is renewed in real time based on a voltage value obtained by the potential sensor. Further, the fine adjustment of the power connection pattern can be made in real time based on measurement data obtained by a water quality monitor of seawater, a temperature sensor, a flow velocity sensor and a picture monitor. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention prevents a sea creature from adhering to the structure by passing a direct current through a titanium film applied to a seawater intake channel or a wall of a structure in contact with seawater such as a hull, and a structure in the vicinity. The present invention relates to an antifouling and anticorrosion device and an antifouling and anticorrosion method for a structure in contact with seawater that performs anticorrosion of objects.

A typical example of a structure in contact with seawater is a water intake facility in a power generation facility installed near the coast in order to use seawater as cooling water, but the inner wall of the intake channel of this water intake facility has Kansashigokai and Barnacles. Other marine organisms such as shellfish are attached. If marine organisms adhere to the intake channel and block the channel, the introduction and discharge of cooling water will be hindered. Therefore, in order to prevent marine organisms from adhering to the intake channel, a conductive coating film is applied to the inner surface of the intake channel, and a direct current is passed through the conductive coating film to conduct hypochlorous acid (ClO ⁻ ) by an electrolysis reaction. An antifouling device has also been proposed in which ions are generated and marine organisms are prevented from adhering to the inner surface of the intake channel due to the ClO 2 ⁻ ions (Patent Document 1).

  In the electrochemical antifouling method using such an antifouling device, in order to maintain the effect over the long term, it is necessary to change according to the environment such as the distribution of potential setting time, and it is difficult to optimally distribute . In addition, if the conductive coating film is excessively oxidized, the electrical resistance value on the surface of the conductive coating film increases, resulting in a decrease in the electrochemical reaction rate, and the set potential is made uniform throughout the conductive coating film. In some cases, it may be difficult to apply the voltage to the. In addition, various problems to be solved have been pointed out, such as the surface of the conductive coating film having a reduced function as an electrode with the deterioration of the constituent materials.

  On the other hand, conventionally, the part that requires antifouling of the antifouling surface of the antifouling body is formed as a corrosion-resistant conductive base material, and the electronic control is characterized by constant current control of the conductive base material. A fungus antifouling method has been proposed (Patent Document 2).

JP-A-9-125341 JP 2004-116136 A

  In a structure that contacts seawater, for example, a power generation facility, there are many various devices and facilities made of corrosive materials such as various large and small pumps, various screens, ladders, and metal pipes in the intake channel. Since these various devices and facilities are affected by the corrosive action of seawater components, some anti-corrosion measures are required.

  In the conventional antibacterial antifouling method using the conventional anticorrosive conductive substrate, the anticorrosion of the electrode part is supported by using an anticorrosive metal material. No consideration has been given to the corrosion protection of sexual materials. Therefore, even when this conventional antibacterial antifouling method using a corrosion-resistant conductive base material is used, the various equipment and facilities are provided with paint thickening treatment, a dedicated anticorrosion power source and an anticorrosion anode. In addition, it is necessary to separately take anti-corrosion measures such as by installing a sacrificial anode, and equipment costs and maintenance costs are further required in addition to anti-fouling measures costs. In addition, when the conventional antibacterial antifouling method using the conventional anticorrosive conductive base material is used in a state where such a separate anticorrosion measure has not been taken, a metal structure other than the antifouling material is energized. A stray current flows through the objects (various devices and equipment), and further accelerates the corrosion of other metal structures.

  In addition, the degree of contamination of the surface of a structure in contact with seawater greatly depends on chemical and physical changes in seawater such as seawater quality, temperature, and flow velocity. Therefore, if the applied current and applied voltage of the antifouling device are not controlled in response to such chemical and physical changes in seawater, effective antifouling cannot be achieved, and economical operation cannot be performed. In some cases, premature wear of the electrode may be caused.

However, in the conventional antibacterial antifouling method using a corrosion-resistant conductive substrate, the corrosion-resistant conductive substrate has a constant value of 20 mA / m ² or more without considering the chemical and physical changes of the seawater. Current is flowing. Under these conditions, even if the antifouling property is realized, it is difficult to realize the above-described anticorrosion property at the same time.

  Further, regarding the point of antifouling, when the antifouling device is started to operate by the antifouling method applying the constant current, it is difficult to improve the antifouling effect at the beginning of energization. May adhere and fix, making subsequent peeling difficult.

  The present invention has been made in view of the above-described conventional problems, and the problem is that the antifouling effect can be maintained even when operated for a long period of time, and the durability of the apparatus is also in contact with seawater that is sustainable for a long period of time. An object of the present invention is to provide an antifouling and anticorrosion device and an antifouling and anticorrosion method.

  In order to solve the above problems, the present inventors have examined the cause of the conventional problem in detail, and have obtained the following knowledge.

  In the conventional device, the degree of performance degradation of the conductive base material used as an electrode was known in real time, and it did not have the function of updating the energization pattern accordingly, so that the performance of the conductive base material deteriorated to some extent over a long period of time after installation. In such a case, it is considered that the antifouling property is significantly lower than the practical level before the durability of the device is exhausted.

  The conventional apparatus does not have a function of updating the energization pattern according to the state of the conductive base material used as the electrode or the surrounding environment. As a result, performance was not demonstrated from the beginning of installation, or titanium reached a state of corrosion in a short period of time, and the antifouling properties were far below the practical level before the durability of the device was exhausted. .

Therefore, the surface potential of the conductive substrate is measured in real time, and the energization setting is kept within the range where the surface potential reaches the “antifouling effective voltage value” until the “antifouling effective time period” elapses. If the energization amount and the pattern are updated appropriately, the energization amount can be minimized, the running cost can be reduced, and a stable antifouling effect can be obtained. In addition, since only the minimum current necessary for antifouling is applied, the degree of increase in potential can be reduced, and energization can be performed for a long period of time in the antifouling effective voltage range (4 V or more and below the elution voltage value of titanium). It becomes possible. The current density that exhibits stable antifouling performance over a long period is about 0.05 A / m ^{2 to} 0.2 A / m ² , and it is desirable to perform polarity switching energization.

  Further, when the antifouling effective potential (titanium potential: 5 V or less) is maintained for a long time in the initial stage of operation, even if the current density is appropriate, the antifouling effect is not sufficiently exhibited. In such a state, if it is maintained for 4 to 5 weeks, many marine organisms will adhere to structures such as intake channels.

  Moreover, when the adhesion of marine organisms was examined, in the region where the potential of titanium exceeded 8-9V (corrosion region of titanium), titanium locally corroded and dissolved, and current concentrated on the corroded portion. It has been found that it is difficult to exert the antifouling effect on the entire surface of the membrane.

  In addition, many marine-adhering organisms bite into the structure surface, adhere via adhesive substances, or physically adhere to the titanium film surface. It became clear that organisms once attached could be detached. However, even if the organism on the surface of the titanium film is peeled off, if the attached organism grows in a large amount to the extent that the attached organism is firmly held on the surface other than the titanium film surface, peeling becomes difficult. Therefore, even if the energized organism does not grow in a large amount, for example, for about 3 months, the attached organism can be peeled off and removed by energization thereafter. Further, for example, when energization is performed in a cycle of 10 days operation / 10 days stop, it can be operated with almost no growth of attached organisms. In this case, the current amount can be halved as compared with the case of continuous operation.

  Further investigations on the attachment of marine organisms have confirmed that the degree of attachment of marine organisms varies with the temperature and flow velocity of seawater and is proportional to the number of living organisms.

  Marine organisms are most active when the seawater temperature is between 20 ° C. and 30 ° C., and their activity decreases at temperatures below 20 ° C. and above 30 ° C. The degree of attachment of marine life to the intake channel increases as the marine life becomes more active. Seawater temperatures rarely exceed 30 ° C, but exceeding 20 ° C often occurs in summer. When the actual applied current density required to maintain the antifouling property when the seawater temperature exceeds 20 ° C. and the actual applied current density at 20 ° C. or less are measured, the actual applied current density is 20 ° C. or less. In the case of, it was found that the temperature may be lower than that in the case of 20 ° C. or higher. Therefore, the seawater temperature is constantly monitored, and the applied current density is different between a predetermined temperature, for example, 20 ° C. or less and when it exceeds 20 ° C., or the current application is temporarily stopped. By doing so, the applied current amount for maintaining the antifouling property in an appropriate range can be set without excess or deficiency. When the total amount of applied current throughout the year was simulated in such a setting, the total amount of applied current throughout the year was greatly reduced compared to when the applied current amount was not adjusted due to changes in seawater temperature. It turned out to be possible. The ability to reduce the total amount of applied current means that the load on the conductive substrate can be reduced by that amount, thereby delaying the performance degradation of the conductive substrate. In addition to controlling the current density, in addition to controlling the “antifouling effective time”, the total applied current amount to maintain the antifouling property properly by adjusting the energization pattern such as energization / non-energization It is also possible to reduce.

  A similar relationship was confirmed for the flow rate of seawater. It was confirmed that marine organisms were more likely to adhere in the absence of flow, and that the higher the seawater flow rate, the less likely it was to adhere. Therefore, when the flow rate of seawater increases, the applied current density is reduced or the total applied current amount is reduced while maintaining the antifouling property in an appropriate range by reducing the “antifouling effective time”. In addition, the life of the conductive substrate can be extended.

  If a video monitor is installed in the vicinity of the conductive substrate and the system is configured so that the number of living organisms of marine organisms can be counted at all times, the applied current density and application time can be adjusted based on the image information. Can do. Thereby, the life of the conductive coating film conductive substrate can be extended while maintaining the antifouling property, similarly to the control by monitoring the seawater temperature and the flow rate of the seawater.

  Moreover, when the mechanism of the attachment of the marine organisms was observed, it was found that marine organisms such as mussels and barnacles adhered to the structure following the following process. That is, (1) First, organic substances such as proteins adhere to the surface of the structure, and (2) bacteria that metabolize the proteins grow and propagate. Subsequently, (3) a slime layer is formed, (4) algae adheres using this slime layer as a landing, and finally (5) marine organisms such as mussels and barnacles adhere.

  In this chained vegetation, when the attachment of marine organisms such as the last mussel is completed, peeling from those structures becomes difficult even if an antifouling current is passed, but the previous stage, i.e. slime or If an antifouling current is applied immediately at the stage where algae or a large organism child is attached, the algae-slime layer-bacteria layer can be easily detached.

The present invention has been made on the basis of the aforementioned findings.
That is, the antifouling and corrosion preventing apparatus for a structure in contact with seawater according to [Claim 1] of the present invention is connected to the titanium film provided on the wall surface of the structure in contact with seawater via an insulating film, and the titanium film. A DC power supply device, a polarity switching device that switches the polarity between the DC anode and cathode, a potential sensor that measures the surface potential of the titanium film, and an energization pattern that is updated based on the voltage value obtained by the potential sensor Control means for sending a control signal to the DC power supply device and the switching device.

  The antifouling and anticorrosion device for a structure in contact with seawater according to [Claim 2] of the present invention is the antifouling and anticorrosion device for a structure in contact with seawater according to [Claim 1], wherein the potential of the titanium film is It is characterized by being 4 V (vs SCE: saturated calomel electrode) or more during antifouling energization.

  The antifouling and anticorrosion device for structures in contact with seawater according to [Claim 3] of the present invention is the antifouling and anticorrosion device for structures in contact with seawater according to [Claim 2], wherein the potential of the titanium film is: An excess current is applied to the titanium film at the initial stage of energization than in the normal operation so as to exceed a necessary potential in a short period of time after installation of the apparatus.

  The antifouling and corrosion preventing apparatus for a structure in contact with seawater according to [Claim 4] of the present invention is the antifouling and corrosion preventing apparatus for a structure in contact with seawater according to [Claim 1], wherein the potential of the titanium film is The amount of current is controlled to be equal to or lower than the elution potential of titanium in seawater.

  The antifouling and anticorrosion device for structures in contact with seawater according to [Claim 5] of the present invention is the antifouling and anticorrosion device for structures in contact with seawater according to [Claim 1], in which the titanium film has a fixed period. It is characterized by repeating energization and non-energization.

  The antifouling and corrosion preventing apparatus for structures in contact with seawater according to [Claim 6] of the present invention is the antifouling apparatus for structures in contact with seawater according to any one of [Claim 1] to [Claim 5]. In the anticorrosion device, a water quality monitor connected to the control means is further provided in the seawater in the vicinity of the titanium membrane, and the control device updates the energization pattern based on the water quality value obtained from the water quality monitor, and the DC A program for sending a control signal to the power supply device and the polarity switching device is stored.

  The antifouling and anticorrosion device for a structure in contact with seawater according to [Claim 7] of the present invention is the antifouling and anticorrosion device for a structure in contact with seawater according to [Claim 6], wherein the water quality monitor is a platinum electrode. It has the structure which measures an electrode reactant density | concentration as said water quality value using a reference electrode.

  The antifouling and corrosion preventing apparatus for structures in contact with seawater according to [Claim 8] of the present invention is the antifouling and corrosion preventing apparatus for structures in contact with seawater according to [Claim 6], wherein the water quality monitor is the potential sensor. And a UV lamp capable of irradiating ultraviolet rays onto the titanium film, and measuring the transparency of seawater and the state of attachment of organisms as the water quality value.

  The antifouling and corrosion preventing apparatus for structures in contact with seawater according to [Claim 9] of the present invention is the antifouling apparatus for structures in contact with seawater according to any one of [Claim 1] to [Claim 8]. In the anticorrosion device, a temperature sensor connected to the control means is further provided in the seawater in the vicinity of the titanium film, and the control device updates the energization pattern based on the seawater temperature value obtained from the temperature sensor. A program for sending a control signal to the DC power supply device and the polarity switching device is stored.

  The antifouling and corrosion preventing apparatus for structures in contact with seawater according to [Claim 10] of the present invention is the antifouling apparatus for structures in contact with seawater according to any one of [Claim 1] to [Claim 9]. In the anticorrosion device, a flow rate sensor connected to the control means is further provided in the seawater in the vicinity of the titanium membrane, and the control device updates the energization pattern based on the flow rate value of the seawater obtained from the flow rate sensor. A program for sending a control signal to the DC power supply device and the polarity switching device is stored.

  The antifouling and anticorrosion apparatus for structures in contact with seawater according to [Claim 11] of the present invention is the antifouling apparatus for structures in contact with seawater according to any one of [Claim 1] to [Claim 10]. In the anticorrosion device, a video monitor connected to the control means is further provided in the seawater in the vicinity of the titanium film, and the control device updates the energization pattern based on the video information obtained from the video monitor, and the DC A program for sending a control signal to the power supply device and the polarity switching device is stored.

  According to [Claim 12] of the present invention, there is provided an antifouling and corrosion preventing apparatus for structures in contact with seawater, wherein the image information is applied to the titanium film in the antifouling and corrosion preventing apparatus for structures in contact with seawater according to [11]. It is characterized by the presence or absence of an organism.

  The antifouling and anticorrosion device for a structure in contact with seawater according to [Claim 13] of the present invention is the antifouling and anticorrosion device for a structure in contact with seawater according to [Claim 12], wherein the update of the energization pattern is as follows. When energization is confirmed on the titanium film from the video information, energization is started, and after energization is maintained for a certain period of time until the deposit on the titanium film is peeled off, the energization is stopped. It is characterized by that.

  The antifouling and corrosion preventing apparatus for a structure in contact with seawater according to [Claim 14] of the present invention is the antifouling apparatus for a structure in contact with seawater according to any one of [Claim 1] to [Claim 13]. In the anticorrosion device, the structure in contact with the seawater is a seawater intake channel.

  According to the fifteenth aspect of the present invention, energization is performed by intermittently repeating one cycle in which a predetermined current density and an application time thereof are set on a titanium film provided on a wall surface of a structure in contact with seawater via an insulating film. An antifouling and anticorrosion method for a structure in contact with seawater that prevents marine organisms from adhering to the wall surface of the structure by passing an electric current based on a pattern, the potential measuring the surface potential of the titanium film A sensor is provided, and the energization amount and the energization pattern are updated based on a voltage value obtained by the potential sensor.

  The antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 16] of the present invention is the antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 15], wherein the potential of the titanium film is It is characterized by being 4 V (vs SCE) or more during antifouling energization.

  The antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 17] of the present invention is the antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 16], in which the potential of the titanium film is An excess current is applied to the titanium film at the initial stage of energization than in the normal operation so as to exceed a necessary potential in a short period of time after installation of the apparatus.

  The antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 18] of the present invention is the antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 15], wherein the potential of the titanium film is The amount of current is controlled to be equal to or lower than the dissolution potential of titanium in seawater.

  According to [Claim 19] of the present invention, there is provided an antifouling and anticorrosion method for a structure in contact with seawater in the antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 15]. It is characterized by repeating energization and non-energization.

  The antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 20] of the present invention is the antifouling method for a structure in contact with seawater according to any one of [Claim 15] to [Claim 19]. In the anticorrosion method, a water quality monitor connected to the control means is further provided in seawater in the vicinity of the titanium film, and the energization pattern is updated based on a water quality value obtained from the water quality monitor.

  The antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 21] of the present invention is the antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 20], wherein the water quality monitor is a platinum electrode. The electrode reactant concentration is measured as the water quality value using a reference electrode.

  The antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 22] of the present invention is the antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 20], wherein the water quality monitor is connected to the potential sensor. And a UV lamp capable of irradiating ultraviolet rays onto the titanium film, and measuring the transparency of seawater and the state of biological adhesion as the water quality value.

  The antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 23] of the present invention is the antifouling method for a structure in contact with seawater according to any one of [Claim 15] to [Claim 22]. In the anticorrosion method, a temperature sensor connected to the control means is further provided in seawater in the vicinity of the titanium film, and the energization pattern is updated based on the seawater temperature value obtained from the temperature sensor.

  The antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 24] of the present invention is the antifouling method for a structure in contact with seawater according to any one of [Claim 15] to [Claim 23]. In the anticorrosion method, a flow rate sensor connected to the control means is further provided in the seawater in the vicinity of the titanium film, and the energization pattern is updated based on the flow rate value of the seawater obtained from the flow rate sensor.

  The antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 25] of the present invention is the antifouling method for a structure in contact with seawater according to any one of [Claim 15] to [Claim 24]. In the anticorrosion method, a video monitor connected to the control means is further provided in seawater in the vicinity of the titanium film, and the energization pattern is updated based on video information obtained from the video monitor.

  The antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 26] of the present invention is the antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 25], in which the titanium film is used as the video information. It is characterized by using the presence or absence of organisms attached to.

  According to [Claim 27] of the present invention, there is provided an antifouling and anticorrosion method for a structure in contact with seawater. In the antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 26], the energization pattern is updated. The energization is started when biological attachment is confirmed on the titanium film from the video information, and the energization is stopped for a certain period of time until the deposit on the titanium film is peeled off. It is characterized by being.

  The antifouling and anticorrosion method for a structure in contact with seawater according to [Claim 28] of the present invention is the antifouling method for a structure in contact with seawater according to any one of [Claim 15] to [Claim 27]. In the anticorrosion method, the structure in contact with the seawater is a seawater intake channel.

  According to the antifouling and anticorrosion device and antifouling anticorrosion device for a structure in contact with seawater according to the present invention, the antifouling and anticorrosion effect of the structure can always be maintained satisfactorily even when operated for a long period of time, and the durability of the device As a result, it is possible to achieve a long-term sustainability and a reduction in running cost.

  EMBODIMENT OF THE INVENTION Below, embodiment of the antifouling anticorrosion apparatus and antifouling anticorrosion method of the structure which touches the seawater concerning this invention is described based on drawing. Note that the embodiments described below are merely examples for suitably explaining the present invention, and do not limit the present invention.

  First, the basic antifouling and anticorrosion principle by the antifouling and corrosion preventing apparatus of the present invention will be described. As shown in FIG. 1, an insulating film 2 is formed on a concrete wall 1a of an intake channel 1, and a pair of conductive films (hereinafter referred to as titanium films) made of titanium which is a corrosive conductive material is formed on the insulating film 2. 3-1 and 3-2 are provided. A direct current is supplied from the power supply device 4 to the titanium films 3-1 and 3-2, and the polarity is switched by the polarity switching device 5 every predetermined time. The titanium films 3-1 and 3-2 are terms described with attention paid to the surface in contact with the seawater surface, and can actually be plate-shaped, foil-shaped, or a combination thereof.

  When the DC power supply device 4 is operated, current flows from the titanium film 3-1 (anode) on the inner wall on one side to the titanium film 3-2 (cathode) on the inner wall on the other side to prevent the attachment of marine organisms. . At this time, if a device such as a pump (not shown) is installed between the anode (titanium film 3-1) and the cathode (titanium film 3-2) and connected to the cathode side, both titanium When the film is charged, there is a part where current flows in and out of the devices along the current flow direction, and the metal corrodes at the current outflow portion. Since the potential of the electric current flowing into the devices is suppressed and the cathode is short-circuited, the devices can be protected from corrosion. Actually, since the titanium film performs a polarity switching operation, the current flowing into the titanium film is controlled to be short-circuited to both poles so that the potential of the devices is maintained at the anticorrosion potential.

  In the antifouling and anticorrosion apparatus of the present invention, various sensors are installed as described below with respect to the above basic configuration to maintain the antifouling and anticorrosive effect at a good level and reduce the running cost. .

  In the figure, reference numerals 6-1 and 6-2 are potential sensors, one potential sensor 6-1 is the surface potential of one titanium film 3-1, and the other potential sensor 6-2 is the other titanium film 3. -2 are elements for measuring the surface potential of -2. These potential sensors 6-1 and 6-2 are connected to the A / D converter 7 through lead wires. The measurement analog signals of the potential sensors 6-1 and 6-2 are converted into digital signals by the A / D converter 7 and input to the computer 8.

  The computer 8 maintains the antifouling effective time based on the time until the surface potential of the titanium films 3-1 and 3-2 reaches an effective voltage (for example, 4V) for antifouling or the differential value of the rising curve at that time. The total energization time for one time required for this is calculated, and the energization pattern for one cycle is updated (updated). Then, the computer 8 inputs a sequence for realizing the energization pattern to the sequencer 9 based on the updated energization pattern. The sequencer 9 to which the updated sequence is inputted sends a command signal to the DC power supply device 4 and the polarity switching device 5 based on the sequence, and realizes a necessary and sufficient energization pattern at that time.

  In the present invention, the surface potential of the titanium film is monitored in real time, and the energization pattern is optimized in real time based on the time until the surface potential reaches the “antifouling effective voltage” or the differential value of the rise. Update. Further, the current density is adjusted so that the surface potential does not exceed the dissolution potential of titanium. These controls are main. In the present invention, a more precise current pattern is updated in real time to adjust the amount of applied current without excess and deficiency, while always maintaining good antifouling properties, saving electrical energy and extending the life of the titanium film. Plan. Therefore, in addition to the potential sensors 6-1 and 6-2, a pair of platinum electrodes 10-1, 10-2 and reference electrodes 11-1, 11-2, a temperature sensor 12, a flow velocity sensor 13, and a video monitor 14 are provided. One or more of the above are provided in the vicinity of the titanium films 3-1 and 3-2 as necessary.

  Hereinafter, the antifouling and anticorrosion method using the various sensors in the antifouling and anticorrosion apparatus having the above configuration will be described as an example.

Example 1
The feature of this embodiment is that a stable oxide film is formed on the surfaces of the titanium films 3-1 and 3-2 at the latest during antifouling energization. It is important that this oxide film has a film quality and a film thickness that can apply a voltage suitable for antifouling to seawater, and is formed in advance on a titanium material before the titanium film is attached to the concrete wall 1a of the water channel 1. May be.

  Alternatively, an oxide film is not formed in advance on the titanium film at the time of installation, and the titanium film is applied in a short time by applying a potential exceeding the potential necessary for antifouling when the apparatus is energized for the first time. An oxide film may be formed on the substrate.

In a conventional antifouling device using a corrosive metal substrate as an electrode, a current amount of about 0.02 A / m ² is applied constantly. As shown in FIG. 2, under such a constant current application condition, the applied voltage is 5 V or less, but under this applied voltage condition, an oxide film is formed on the surface of the corrosion-resistant conductive substrate, and the surface potential of the conductive substrate. It takes about 4 to 5 weeks for the potential to reach a potential effective for antifouling (about 4V). During this period, the electrode surface potential is 4 V or less, and the antifouling effect is not improved (no antifouling property). The period of 4 or 5 weeks in a state without antifouling is a period sufficient for many marine organisms to adhere to and settle on the intake channel.

On the other hand, in this invention, the electric current of about 0.2-0.3 A / m < ² > is applied at the time of the first driving | operation start after apparatus installation. By energizing this high amount of current, the potential on the surface of the titanium oxide film exceeds 4 V in 3 and 4 days. After reaching this state, the applied current amount is shifted down to about 0.1 to 0.2 A / m ² . By introducing such an energization pattern in the initial stage, the antifouling action at the beginning of installation of the apparatus can be rapidly developed, and adhesion of marine organisms often occurring at the beginning of installation to the intake channel can be prevented.

  In addition, the potential gradually increases with long-term operation, and eventually reaches a potential at which a titanium dissolution (corrosion) reaction occurs. Since it is difficult to stably exhibit antifouling properties under conditions where titanium corrodes, an upper limit potential (about 8 V to 9 V) is set, and when the upper limit potential is reached, the current flow rate is temporarily reduced. By adopting such an energization method, it becomes possible to suppress the corrosion of titanium and to prolong the life of maintaining the antifouling property.

(Example 2)
In the present embodiment, the temperature sensor 12 is used to measure the seawater temperature, and the energization pattern is controlled according to the fluctuation of the seawater temperature. As described above, marine organisms are most active when the seawater temperature is between 20 ° C. and 30 ° C., and their activity decreases at temperatures below 20 ° C. and above 30 ° C. The degree of attachment of marine life to the intake channel increases as the marine life becomes more active. Seawater temperatures rarely exceed 30 ° C, but exceeding 20 ° C often occurs in summer. When the actual applied current density required to maintain the antifouling property when the seawater temperature exceeds 20 ° C. and the actual applied current density at 20 ° C. or less are measured, the actual applied current density is 20 ° C. or less. In this case, the temperature may be lower than that in the case of 20 ° C. or higher. In the computer 8, when the seawater temperature becomes 20 ° C. or higher, the applied current density to each of the titanium membranes 3-1, 3-2 is set to 0.2 A / m ^2. / M ² . Normally, it was fixedly set at 0.2 A / m ² throughout the year, so the total applied current can be significantly reduced annually, and the load on the titanium film is reduced by that reduced amount. Prolonging the life of the conductive substrate can be expected. The set value of the applied current density is an empirical value based on experimental data conducted throughout the year, and may be changed by collecting and analyzing a large amount of experimental data and actual measurement data by actual operation. There is.

(Example 3)
The relationship between the seawater temperature and the maintenance of antifouling properties was also confirmed for the flow rate of seawater. In this embodiment, the flow rate of seawater is measured using the flow rate sensor 13, and the energization pattern is changed based on the measured value. When the flow rate of seawater exceeds 1.4 m / sec, most marine organisms are difficult to attach, so the applied current density can be reduced to 0.1 A / m ² even in summer. The control of the applied current density by the change in the flow velocity of the seawater and the control of the applied current density by the change in the temperature are referred to each other, and a program is set so that the final determined value is performed by the computer 12.

  Thus, when the flow rate of seawater becomes faster, the total applied current amount is reduced while maintaining the antifouling property in an appropriate range by reducing the applied current density, and the titanium films 3-1, 3 -2 can be extended.

Example 4
In the present embodiment, the video monitor 14 is installed in the vicinity of the conductive base material, the surface state of the titanium films 3-1, 3-2 is constantly monitored, and the energization pattern is changed based on the state. . Video information from the video monitor 16 is sent to the computer 8 via the A / D converter 7, and the surface state of the titanium films 3-1 and 3-2 is digitized by an image processing program incorporated in the computer 8. Is done. As the surface state of the titanium films 3-1 and 3-2, the presence or absence of algae, slime, and large organism children attached to the titanium film surface is used. As shown in FIG. 3, energization is started when biological attachment is confirmed on the titanium films 3-1 and 3-2 from the image information of the surface states of the titanium films 3-1 and 3-2. After energization is maintained for a certain period until the deposits on the titanium films 3-1 and 3-2 are peeled off, the energization is stopped. With this energization pattern, the application of antifouling current is started immediately before the growth of marine organisms such as mussels, that is, at the stage where algae and small organisms adhere to the titanium films 3-1, 3-2. Therefore, the algae-slime layer-bacteria layer can be easily peeled off.

  By updating and maintaining the energization pattern that repeats the above-described operation-stop based on the video information, the total applied current amount can be greatly reduced while maintaining the antifouling property and the anticorrosion property. By providing the energization stop period, not only the total energization amount can be reduced, but also the load on the titanium film can be reduced, and the life of the titanium film can be extended. It is possible to extend the service life from about 1 year to 2 to 4 years. The operation / stop pattern may be programmed based on not only video information but also empirical information and test results.

(Example 5)
In the present embodiment, the water quality of the seawater is measured by a water quality monitor, and the energization pattern is changed based on the measured water quality value to maintain good antifouling performance and reduce the running cost. As the water quality monitor, as shown in FIG. 1, the electrode reactant concentration is measured as the water quality value using a pair of platinum electrodes 10-1 and 10-2 and reference standard electrodes 11-1 and 11-2. And

  The result of periodically monitoring the water quality with a water quality monitor composed of platinum electrodes 10-1, 10-2, etc. is reflected in the energization pattern to the titanium films 3-1, 3-2. More specifically, the potential of the platinum electrodes 10-1 and 10-2 provided in the vicinity of the titanium films 3-1 and 3-2 is periodically scanned, and from the integrated value of the amount of current flowing, The amount of the reactive substance (electrode reactant) contained is calculated and reflected in the energization amount to the titanium films 3-1, 3-2. The potentials of the platinum electrodes 10-1 and 10-2 are scanned, and the amount of the reactive substance in the seawater is estimated from the change in the integrated current value. FIG. 4 is a graph showing changes in measured values when water quality is normal and examples of changes in measured values when water quality deteriorates. As can be seen from the result of cyclic voltammetry (potential scanning) using the platinum electrode, the water quality can be determined from the relationship between the applied current density and the measured potential. From this measurement result, for example, when the integrated value of the current from −0.5 V to 1 V is larger than the normal state, it is understood that the water quality is deteriorated. Therefore, the amount of the reactive substance in the seawater can be calculated from the result of cyclic voltammetry. The current density applied to the titanium films 3-1 and 3-2 is feedback controlled according to the amount of the reactive substance. Specifically, if the reactive substance increases, the amount of current applied to the titanium films 3-1 and 3-2 is increased accordingly.

(Example 6)
A feature of the present embodiment is that the water quality monitor uses the titanium films 3-1, 3-2 and an ultraviolet lamp (light irradiation lamp) 15 capable of irradiating the titanium films 3-1, 3-2 with ultraviolet rays. Therefore, the transparency of seawater is measured as the water quality value.

  Titanium oxide absorbs ultraviolet rays, and an internal current easily flows. Therefore, when a constant current is applied to the titanium films 3-1 and 3-2 when the titanium films 3-1 and 3-2 are irradiated with ultraviolet rays from the light irradiation lamp 15, the potential sensors 6-1 and 6-6 are applied. The potential on the surfaces of the titanium films 3-1 and 3-2 measured at 2 is lowered. The degree of the potential decrease depends on the transparency of the seawater and the amount of organisms attached to the surface, and as a result, the transparency of the seawater and the state of the titanium film can be monitored. Furthermore, if it is used in combination with the video monitor 14, it is possible to easily confirm the state of attachment of organisms (because light is blocked) to the inner surface of the intake channel 1.

  As described above, the antifouling and anticorrosion device and antifouling anticorrosion device for structures in contact with seawater according to the present invention effectively prevent marine organisms from adhering to structures in contact with seawater such as seawater intake channels. In addition, the antifouling and anticorrosion effect can be satisfactorily maintained even when operated for a long period of time, and the durability of the apparatus can also be maintained for a long period of time, thereby reducing both maintenance costs and running costs. .

It is a figure which shows schematic structure of an example of the antifouling | corrosion anticorrosion apparatus of the structure which touches the seawater concerning this invention. FIG. 2 is a graph illustrating the first embodiment of the present invention, in which the probability of the electrode surface potential necessary for antifouling properties due to the consumption of applied power consumed for forming an oxide film on a titanium film is delayed. It is. It is a figure for demonstrating the 4th Example of this invention, and is a figure which shows the electricity supply pattern at the time of making attachment of a marine organism also possible by providing an electricity supply stop period intermittently. For explaining the fifth embodiment of the present invention, the result of measuring the amount of the reactive substance in the seawater by scanning the potential of the platinum electrode and changing the integrated value of the current amount is shown as a graph. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Seawater intake channel 1a Concrete wall of intake channel 2 Insulation film 3-1, 3-2 Titanium film 4 DC power supply device 5 Polarity switching device 6-1, 6-2 Potential sensor 7 A / D converter 8 Computer 9 Sequencer 10-1, 10-2 Platinum electrode 11-1, 11-2 Reference electrode 12 Temperature sensor 13 Flow rate sensor 14 Video monitor 15 Light irradiation lamp

Claims (28)

  A titanium film provided on a wall surface of a structure in contact with seawater via an insulating film, a DC power supply device connected to the titanium film, a polarity switching device for switching the polarity between a DC anode and a cathode, and the titanium film Seawater characterized by comprising: a potential sensor for measuring a surface potential; and a control means for updating a conduction pattern based on a voltage value obtained by the potential sensor and sending a control signal to the DC power supply device and the switching device. Antifouling and anticorrosion equipment for structures in contact   2. The antifouling and corrosion preventing apparatus for structures in contact with seawater according to claim 1, wherein the potential of the titanium film is 4 V (vs SCE: saturated calomel electrode) or more during antifouling energization.   The excess current from the normal operation is applied to the titanium film at an initial stage of energization so that the potential of the titanium film exceeds a necessary potential in a short period after installation of the apparatus. Antifouling and anticorrosion equipment for structures in contact with seawater.   The antifouling and anticorrosion device for structures in contact with seawater according to claim 1, wherein the amount of current is controlled so that the potential of the titanium membrane is equal to or less than the elution potential of titanium in seawater.   2. The antifouling and corrosion preventing apparatus for a structure in contact with seawater according to claim 1, wherein the titanium film is repeatedly energized and de-energized for a certain period.   A water quality monitor connected to the control means is further provided in the seawater in the vicinity of the titanium membrane, and the control device updates an energization pattern based on a water quality value obtained from the water quality monitor, and the DC power supply and polarity The program for sending a control signal to the switching device is stored, and the antifouling and anticorrosion device for a structure in contact with seawater according to any one of claims 1 to 5.   The antifouling and anticorrosion apparatus for a structure in contact with seawater according to claim 6, wherein the water quality monitor has a configuration in which an electrode reactant concentration is measured as the water quality value using a platinum electrode and a reference electrode.   The said water quality monitor has the structure which measures the transparency of seawater and the adhesion condition of a living organism | raw_food as said water quality value using the said potential sensor and the ultraviolet lamp which can irradiate a titanium film with an ultraviolet-ray. Antifouling and anticorrosion equipment for structures in contact with seawater.   A temperature sensor connected to the control means is further provided in the seawater in the vicinity of the titanium membrane, and the control device updates the energization pattern based on the seawater temperature value obtained from the temperature sensor, and the DC power supply device and The program for sending a control signal to the polarity switching device is stored, and the antifouling and corrosion preventing device for a structure in contact with seawater according to any one of claims 1 to 8.   A flow rate sensor connected to the control means is further provided in the seawater in the vicinity of the titanium membrane, and the control device updates the energization pattern based on the flow rate value of the seawater obtained from the flow rate sensor, and the DC power supply device A program for sending a control signal to the polarity switching device is stored, and the antifouling and anticorrosion device for structures in contact with seawater according to any one of claims 1 to 9.   A video monitor connected to the control means is further provided in the seawater in the vicinity of the titanium membrane, and the control device updates the energization pattern based on video information obtained from the video monitor, and the DC power supply and polarity The program for sending a control signal to the switching device is stored, and the antifouling and corrosion preventing device for a structure in contact with seawater according to any one of claims 1 to 10.   12. The antifouling and corrosion preventing apparatus for structures in contact with seawater according to claim 11, wherein the video information is presence or absence of organisms attached to the titanium film.   Update of the energization pattern starts energization when the biological information is confirmed on the titanium film from the video information, and after maintaining the energization for a certain period until the deposit on the titanium film is peeled off, The antifouling and anticorrosion device for a structure in contact with seawater according to claim 12, characterized in that energization is stopped.   14. The antifouling and corrosion preventing apparatus for structures in contact with seawater according to any one of claims 1 to 13, wherein the structure in contact with seawater is a seawater intake channel. A current is passed through a titanium film provided on the wall surface of a structure in contact with seawater via an insulating film, based on a conduction pattern that intermittently repeats one cycle in which a predetermined current density voltage and its application time are set. By the antifouling and anticorrosion method for the structure in contact with seawater that prevents marine organisms from attaching to the wall surface of the structure,
An antifouling and anticorrosion method for a structure in contact with seawater, comprising a potential sensor for measuring a surface potential of the titanium film, and updating the energization amount and energization pattern based on a voltage value obtained by the potential sensor.   The antifouling and anticorrosion method for a structure in contact with seawater according to claim 15, wherein the potential of the titanium film is 4 V (vs SCE) or more during antifouling energization.   The excess current from the normal operation is applied to the titanium film at the beginning of energization so that the potential of the titanium film exceeds a necessary potential in a short period of time after installation of the apparatus. Antifouling and anticorrosion methods for structures in contact with seawater.   The antifouling and anticorrosion method for a structure in contact with seawater according to claim 15, wherein the amount of current is controlled so that the potential of the titanium film is equal to or less than the dissolution potential of titanium in seawater.   The antifouling and anticorrosion method for a structure in contact with seawater according to claim 15, wherein the titanium film is repeatedly energized and de-energized for a certain period.   The water quality monitor connected to the control means is further provided in the seawater in the vicinity of the titanium membrane, and the energization pattern is updated based on a water quality value obtained from the water quality monitor. An antifouling and anticorrosion method for a structure in contact with seawater according to claim 1.   21. The antifouling and anticorrosion method for a structure in contact with seawater according to claim 20, wherein the water quality monitor is configured to measure an electrode reactant concentration as the water quality value using a platinum electrode and a reference electrode.   21. The structure according to claim 20, wherein the water quality monitor is configured to measure seawater transparency and biological attachment status as the water quality value using the potential sensor and an ultraviolet lamp capable of irradiating the titanium film with ultraviolet rays. Antifouling and anticorrosion methods for structures in contact with seawater.   The temperature sensor connected to the control means is further provided in the seawater in the vicinity of the titanium membrane, and the energization pattern is updated based on the seawater temperature value obtained from the temperature sensor. An antifouling and anticorrosion method for a structure in contact with seawater according to item 1.   The flow rate sensor connected to the control means is further provided in the seawater in the vicinity of the titanium membrane, and the energization pattern is updated based on the flow rate value of the seawater obtained from the flow rate sensor. An antifouling and anticorrosion method for a structure in contact with seawater according to claim 1.   The video pattern connected to the control means is further provided in the seawater in the vicinity of the titanium membrane, and the energization pattern is updated based on video information obtained from the video monitor. An antifouling and anticorrosion method for a structure in contact with seawater as described in the paragraph.   26. The antifouling and anticorrosion method for a structure in contact with seawater according to claim 25, wherein presence or absence of organisms attached to the titanium film is used as the video information.   After the energization pattern is updated, the energization is started when biological attachment is confirmed on the titanium film from the video information, and the energization is maintained for a certain period of time until the deposit on the titanium film is peeled off. 27. The method for preventing fouling and corrosion of a structure in contact with seawater according to claim 26, wherein energization is stopped.   The antifouling and anticorrosion method for a structure in contact with seawater according to any one of claims 15 to 27, wherein the structure in contact with seawater is a seawater intake channel.

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