JP2007055568A - Low-frequency current type ship bottom anti-fouling system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-frequency current type ship bottom anti-fouling system capable of effectively preventing attachment of attached organisms such as crustacean such as barnacle and shellfish, and seaweeds to a ship bottom by using the low-frequency current. <P>SOLUTION: A plurality of electrodes are arranged underwater on an outboard shell, and the supply current is converted into the low-frequency current. The low-frequency current is conducted between the electrodes with water around the ship periphery as a conductor to realize the attachment preventive effect of attached organisms. In particular, the current is conducted simultaneously, cyclically or at random from one selected anodic electrode to a plurality of cathodic electrodes, and the direction and the intensity of the low-frequency current underwater are controlled to enhance the attachment preventive effect. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a low-frequency current-type ship bottom antifouling system for preventing crustaceans such as barnacles and shellfish attached to the ship bottom, and algae such as algae using a low-frequency current.

  In general, it is known that there are many species of organisms that grow in contact with water and structures that come into contact with water in marine and seawater. And especially in seawater, this marine-adherent organism is a big problem. Among the adherent organisms, large adherent organisms such as barnacles and shellfish adhere to the surface of seawater contact structures such as ships and breakwaters, causing various troubles. For example, if the adherent organisms adhere to the bottom of a ship in a ship, the resistance of water when the ship moves forward increases, resulting in an unfavorable situation such as poor fuel consumption.

  Usually, shellfish such as barnacles, shellfish, and algae are likely to adhere to the bottom of a ship in the ocean, and as a countermeasure against the drop in speed of the ship, a bottom paint containing poison is applied to the bottom of the ship. The active ingredient in the paint gradually dissolves and the anti-adhesion effect does not last forever. Therefore, it is necessary to frequently set up a ship, scrape the attached organism, and repaint the ship bottom. On the other hand, poisons in ship bottom paints are one of the causes of marine pollution, and there is a tendency that toxicity is gradually regulated, and the present situation is that shipowners are struggling with antifouling countermeasures.

Therefore, since the work of removing organisms attached to the bottom of the ship is troublesome, a method or apparatus for preventing the attached organisms such as barnacles from adhering to the bottom of the vessel has been considered.
JP-A-5-170176 JP 2002-317282 A Japanese Patent Laid-Open No. 2004-27500 JP 2004-339882 A

  Among these, (1) a method of preventing the generation of seaweed and shellfish with the hypochloric acid generated by enveloping the ship's bottom plate with an insulating sheet and electrolyzing the seawater, ▼ Forming an electrocoating layer composed mainly of calcium carbonate and magnesium hydroxide by applying direct current power between the cathode coated with corrosion-resistant metal on the surface of the seawater contact structure and the anode placed against it. Either by dissolving and removing this with a reverse current or by (3) electrolyzing seawater to generate hydroxy ions from the surface of the antifouling plate to prevent the attachment of marine organisms. Anti-fouling measures are being taken to prevent the generation of seaweed and shellfish by the action of things.

  However, the above-mentioned patent documents and the like are in a method and apparatus for preventing growth of barnacles, shellfish, and the like attached to a ship bottom using an electrolyte generated by electrolysis of seawater. A large amount of electric power is consumed in order to use the decomposition product generated by this electrolysis. For this reason, in a situation where power from the land cannot be used, a large-capacity battery is required and a large-scale device is required. If the apparatus is large, the installation cost becomes high, and it is difficult to install on a ship physically and economically. Thus, small ships still have to rely on toxic ship paints.

  In addition, the method of generating an electrolyte by electrolysis of seawater requires a specific electrode to generate a toxic electrolyte. And this electrode has the disadvantage that it is very worn and must be replaced frequently. Moreover, many electrolytes generated by electrolysis are highly toxic and there is a concern of marine pollution. In particular, seawater always flows and moves, whether in the bay or the ocean, so the toxic electrolyte moves in a wave and is used for the purpose of preventing the growth of the original adherent organisms. Other environmental pollution is inevitable.

  Here, the present invention has been devised in view of such circumstances to solve the problem. In the first place, barnacles are hermaphroditic in the case of typical barnacles of adherent organisms, and cross-fertilization occurs between adjacent solids. It hatches from nauplius from eggs, passes through metanoprius, and becomes cypris larvae with bivalve shells. Cypris larvae scour the surface of the adhesion with the antennae while in the sea, and when it is good, immediately release the adhering substance from the cement gland at the base of the first antennae, peel off at the same time as adhesion, and transform into a young barnacle. Once attached, the number is increasing due to creatures that do not move. If the adherent surface is unsuitable, it is said that it will survive without transformation for a period of time until a good place is encountered.

  In the present invention, a low frequency current is caused to flow in the vicinity of the bottom of the ship, thereby setting an environment that is particularly disliked by barnacle larvae and controlling the barnacles not to approach the bottom of the ship. And by arranging a plurality of electrodes in the sea water on the outer wall of the ship so that the low-frequency current can be passed through the entire bottom of the ship, the low-frequency current is controlled to further enhance the effect of preventing the attachment of barnacles and the like. There is. The present invention is not a method of consuming a large amount of power as in the prior art by forcing a low frequency as a current to forcibly generate a highly toxic electrolysate. A simple low-frequency current-type ship bottom antifouling system that is optimal for small vessels that can be used for a long time without using a large-capacity battery.

Means for Solving the Invention

  That is, according to the present invention, as shown in the claims, a plurality of electrodes are arranged in the sea water on the outer wall of the ship, the current power source is converted into a low frequency current, and the light and sea water around the ship is used as a conductor. A low-frequency current type bottom antifouling system characterized by passing a low-frequency current from an electrode to a negative electrode. Furthermore, in a plurality of electrodes, a current is passed simultaneously or intermittently from a selected positive electrode to a plurality of remaining negative electrodes. A current is cyclically applied to the negative electrode. Furthermore, a current is randomly applied from one anode to a plurality of cathodes. Thus, the low-frequency current type ship bottom antifouling system is characterized in that a low-frequency current is supplied to and controlled in seawater in the vicinity of the ship bottom. In addition, since the present invention does not compulsorily obtain an electrolyzed product generated by energization, there is no limitation on the material selection of the electrode, and therefore, a stainless steel electrode that is resistant to electrolysis can be selected as the electrode. It is in the frequency current type ship bottom antifouling system.

  In the configuration as described above, the plurality of electrodes referred to in the present invention means that the number of electrodes is increased according to the size of the ship, that is, the area of the ship bottom, with at least a pair of positive and negative electrodes as a minimum. It shows that. In the case of covering this energization over a wide range, the number of electrodes is adjusted according to the combination of the number of electrodes arranged on the outer wall of the ship and the amount of electricity to be energized. From the results of the field test, it is sufficient to place, for example, about 50 × 10 mm disk-shaped electrodes every 5 to 10 feet in the sea water on the outside of the ship. Moreover, since it is not necessary to generate a toxic substance by forced electrolysis from the electrode of the present invention, it is not necessary to select an electrode made of a specific material. For example, an electrode made of a material resistant to electrolysis such as stainless steel can be selected. The shape of the electrode is not particularly limited, and examples thereof include a disk shape, a rectangle, a triangle, a sphere, and a streamline shape. Then, if the electrode interferes with traveling while the ship is traveling, it is sufficient to lift the electrode into the ship and place the electrode in seawater on the outer wall of the ship when anchored.

The low frequency current referred to in the present invention is a direct current having a frequency of 10,000 cycles or less per second, which is obtained by converting a power source current into a direct current low frequency. As a low-frequency current that is energized in seawater, it is usually sufficient to construct a low-frequency current layer of 10 to 50 volts, 0.1 to 5.0 amperes.

  In the present invention, the current control means (1) from one selected positive electrode to a plurality of remaining negative electrodes at the same time or by setting the order of the plurality of negative electrodes, This means that the negative electrode is set at random and has a means for flowing current. (2) In addition to the above conditions, it means having a means for flowing current by setting the current to flow continuously or intermittently. Furthermore, (3) the position of the positive electrode does not need to be fixed, one of the plurality of electrodes is selected as the positive electrode, and the remaining electrode is used as the negative electrode, that is, in the sea water on the outer wall of the ship. The entire bottom of the ship can be uniformly covered with a low-frequency current. This means having a means for flowing current by selecting the order of the positive electrodes or randomly. These include (4) means for flowing current by changing the amount of low-frequency current.

  By controlling the current flow in the seawater by combining the above-mentioned conditions, a directional current can be passed over the entire bottom of the ship. By controlling the flow of current in seawater, for example, by flowing a current locally, it is possible to further enhance the effect of preventing adherent organisms such as barnacles. That is, by setting this condition and passing a low-frequency current to the bottom of the ship, creating an environment that is particularly disliked by barnacle larvae, so that crustaceans such as barnacles and shellfish, algae adherent organisms do not approach the ship bottom, It can prevent adhesion and propagation. In addition, the use of low-frequency currents is environmentally friendly and consumes very little power, and can be used without being charged even during long-term mooring without using a large-capacity battery.

Hereinafter, the present invention will be described more specifically based on embodiments described in the drawings.
Here, FIG. 1 is a front conceptual view showing an example of an embodiment of the present invention provided on a ship, and FIG. 2 is a side conceptual view showing an example of an embodiment of the present invention provided on a ship.
In the figure, the low-frequency current type antifouling system is a system that uses the low-frequency current flowing in seawater to prevent crustaceans such as barnacles, shellfish, and algae from adhering to the bottom A, and allows low-frequency current to flow. A plurality of electrodes 1.2.3.4.5. And a low frequency current generator C that changes the power source B to a low frequency current, and a current controller D that controls the current.

  Hereinafter, the present invention will be described more specifically based on embodiments described in the drawings. Here, A in FIG. 1 is the bottom of a 25-foot ship floating in seawater. B is a power source unit made of solar or battery, etc., and the DC power received from the power source unit B is converted into a low frequency current by the C low frequency generation unit, and is supplied to the electrodes 1 to 5 via the D current control unit. Low frequency current was distributed. The five electrodes used at this time were a disc-shaped stainless steel plate with a diameter of 30 mm and a thickness of 10 mm, one in the center of the bow, one on each of the left and right sides of the ship, and one on each of the left and right sides of the stern. And placed in the sea water on the outer wall of the ship.

  The current control unit D has a simple keyboard and display screen, and is provided with necessary operation knobs such as a switch for adjusting the amount of current and voltage, and further selecting the positive electrode and adjusting the power distribution order to the negative electrode. Yes. And it has the function to control so that the whole ship bottom is covered with the low frequency current by shifting the distribution time of the low frequency current from the current control unit D and the order of the distribution. The current control unit D is connected to a low frequency generation unit C from 12 volts or 24 volts. The low-frequency current received from the low-frequency generator C is preferably in the range of 0.5 to 1.0 ampere, which is disliked by adherent organisms such as barnacle larvae floating in the sea. And the intensity | strength is selected and controlled by the generation | occurrence | production state of an adhering organism.

  As an example of power distribution control, in the case of the above-described ship in which five electrodes are arranged in seawater on the outer wall of the ship, in the current control unit D, the electrode 1 at the bow portion is selected as the positive electrode and the remaining electrodes 2-5 Was set as a negative electrode, and the same output current was simultaneously supplied from the positive electrode (electrode 1) to the remaining four negative electrodes (electrodes 2 to 5). As a result, it was confirmed that a low-frequency current flows through the entire bottom of the ship, but a stronger current flows on the side of the negative electrodes 2 and 3 than on the negative electrodes 4 and 5.

  As a next example, in the current control unit D, the left stern electrode 5 is selected as the positive electrode, the remaining electrodes 1 to 4 are set as negative electrodes, and the remaining four negative electrodes (electrodes) from the positive electrode (electrode 5) 1 to 4), current was circulated in the order of 1, 2, 3 and 4.

  As another example, in the current control unit D, the electrodes 1 to 5 were sequentially selected as positive electrodes, and current was repeatedly distributed to the remaining negative electrodes. As a result, the entire ship bottom could be covered with the low frequency current. Of course, the distribution of electric power with periodic changes in the amount of electric power has also brought about the effect of keeping the attached organisms away from the ship bottom.

  Furthermore, it was possible to arbitrarily distribute the current locally to a specific negative electrode or to distribute the current after a certain interval by operating the terminal at the current control unit D. As a result of current measurement in the seawater, it was confirmed that the low-frequency current covered the entire bottom of the ship without being affected by the wave of seawater that was rough around the ship.

  The purpose of the present invention is not to kill adherent organisms with toxic substances generated by electrolysis. The purpose is to create an environment in which the attached organisms dislike by flowing a low-frequency current through the seawater so that the attached organisms do not approach the ship bottom and attach. As a result of field experiments, it was confirmed that other shellfish and algae hardly adhere to the bottom of the ship where barnacles do not adhere.

The invention's effect

  As is apparent from the above description, according to the low-frequency current type antifouling system of the present invention, barnacle larvae are brought close to the bottom of the ship using low-frequency currents that shellfish such as barnacles, particularly barnacle larvae dislike. There is to not let it. As a result, crustaceans such as barnacles, shellfish, and algae can be prevented from adhering and breeding. In addition, it is possible to further enhance the adhesion preventing effect by arranging a plurality of electrodes for passing a low frequency current on the outside of the ship bottom and covering the entire ship bottom with a curtain of the low frequency current.

  Since the present invention is not a conventional system aimed at toxic effects such as chlorine-based gas generated by electrolysis, it is not necessary to select a special electrode, and it is economical to select an electrode that is resistant to electrolysis. . In addition, since the present invention employs a low-frequency current flowing between the electrodes, it is less susceptible to tides and seawater flow like toxic substances generated by electrolysis, so it is efficient without wasteful power consumption. is there. In this way, the problems that had been greatly affected in the past could be solved at once.

  Combined with these effects, the power consumption for generating low frequencies is extremely small, and the entire device is also small and can be used on small ships moored for a long time. In the case of a large ship, it is of course possible to have an effect by installing a large number of electrodes. In the case of a large ship, the low-frequency current system of the present invention can be divided into a plurality of parts by dividing it into a bow and a stern. By installing, the adhesion preventing effect can be further enhanced.

  1 is a conceptual front view 1 illustrating an example of an embodiment of the present invention.   It is side surface conceptual diagram 2 which shows an example of the embodiment of this invention.

Explanation of symbols

A ... Bottom of ship B ... Power supply part C ... Low frequency current generation part D ... Current distribution part 1 ... Electrode 1
2 ... Electrode 2
3 ... Electrode 3
4 ... Electrode 4
5 ... Electrode 5

Claims (3)

  A plurality of electrodes are placed in the water on the outer wall of the ship, and the current source is converted into a low-frequency current so that the water around the ship is energized from one positive electrode selected as a conductor to the negative electrode. Low frequency current type ship bottom antifouling system.   To control the direction and strength of the low-frequency current in water by simultaneously or cyclically or randomly energizing the remaining negative electrodes from the selected positive electrode in a plurality of electrodes. The low frequency current type ship bottom antifouling system according to claim 1, characterized in that:   3. The low frequency current type ship bottom antifouling system according to claim 1, wherein the electrode is made of stainless metal.

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