JPH05123079A - Underwater fence - Google Patents

Abstract

PURPOSE:To obtain an underwater fence capable of installing at long intervals and being excellent in economical efficiency and maintenance and useful for fish farm by forming a coating film of a metal of the group platinum on the surface of a corrosion resistant metal of the fence. CONSTITUTION:The objective underwater fence 1 obtained by forming a coating film containing one or more kinds of oxides of metal of the group platinum selected from platinum metals or ruthenium oxide, iridium oxide and rhodium oxide and capable of applying alternating current on the surface of a corrosion resistant metal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an undersea fence which is used as a fish farm or an ocean ranch by partitioning an entrance of a certain sea area, a harbor, an inlet, etc.

[0002]

2. Description of the Related Art It has long been practiced to provide a cage under the sea, hold a fish in the cage, and cultivate fish. The kettle used for such a purpose is made of a net or a fence having a small clearance so that the fish cannot escape.

However, this method is effective for purposes such as relatively small-scale fish farming, but it is almost impossible to use it for large-scale fish farming that divides the entire harbor or cove, and it resembles migratory fish. It could not be used for aquaculture that requires a large area such as large-scale fish culture.
In addition, when a boat is put in a living room, it is surrounded by a net, so that there is a problem that the entrance and exit of the boat is limited to a special place. In addition, since seaweeds and shellfish attach to the meshes of sacs, it is necessary to use materials that do not allow these marine organisms to adhere to the material of the sausage, but materials that do not adhere to marine organisms can be used by the human body. There are some things that are not preferable, and there is a limit to preventing marine life from attaching.

For this reason, the opening needs to have a certain size so that the seawater can sufficiently flow even if marine organisms adhere to it. However, if the size of the opening is large, small fish can be used. There was also the problem of escaping, or conversely, external enemies from the outside.

[0005]

[Problems to be Solved by the Invention] In order to trap fish in a certain sea area without depending on a net having a mesh or the like, it is stimulated by light such as laser light, sound waves, or electricity to confine it in a sea area. Is proposed. The method using laser light is said to be more effective in preventing invasion of external enemies than sound waves, and it has the effect that fish can be prevented from moving in a wide range by increasing the output. As with sound waves, the fish used to get used to the laser light, and eventually there was a problem that the fish could not be trapped within a certain range.

Therefore, it has been proposed to use an electrical stimulus that fishes do not become accustomed to, such as sound waves or laser light. In other words, it has become clear that if there is an electric field of a certain strength or higher in seawater, there will be no entry and exit at that point, and a method has been adopted in which an electric field is formed to replace the mesh. That is, instead of a mesh or a fence, a rod-shaped electrode is installed with a large gap so that the fish can pass through sufficiently, and a current of about 20 V is applied between the electrodes to electrically stimulate the fish. is there.

FIG. 1 shows an example of a method for preventing fish from entering and leaving in a certain sea area by energizing an undersea fence. A submarine fence 1 made of corrosion-resistant metal is installed at intervals in the sea, and a current is applied between adjacent submarine fences from a power supply line 2 to prevent fish from entering and exiting due to the electric field formed between the subsea fences. is there.

In this method, a steel material plated with copper or zinc is used, but when a current is applied between the undersea fences, electrolysis occurs in the case of direct current, and the anode side electrode is consumed. However, even in the case of alternating current, the positive and negative polarizations are repeated on the electrode surface, and the electrode is consumed. And from the metal of the electrode material, poisonous copper ions, zinc ions,
There is a problem that iron ions and the like are eluted, which is not preferable from the viewpoint of environmental protection, and that the electrodes need to be replaced regularly.

Further, there is a problem that a high voltage cannot be applied in order not to increase the consumption amount of the undersea fences. Therefore, it is necessary to reduce the interval between the undersea fences and install many undersea fences. .. As a result, similar to the nets, there were problems such as blocking the passage of ships along with economic efficiency.

The present invention has been made to solve the above problems, and an object thereof is to effectively realize an undersea fence by an electric field with a smaller number of electrodes.

[0011]

MEANS FOR SOLVING THE PROBLEMS The present invention provides a metal of the platinum group as an undersea fence for preventing fish from entering and exiting within a certain range by applying electric stimulation to fish by forming an electric field in seawater. Alternatively, a corrosion-resistant metal formed with a coating containing the oxide is used.

The submarine fence of the present invention can be energized with either direct current or alternating current, but in general it is necessary to convert commercial alternating current into direct current in order to obtain direct current, so the cost is low. From the aspect, it is preferable to apply an alternating current.

In order to form the electric field, it is sufficient that a very small electric current is flowing in the seawater, and the electric current is about several mA to several A / m ^{2 in the} portion of the undersea fence where the seawater is energized.

In order to energize the seawater, it is necessary to pass an electric charge from the undersea fence to the ions existing in the seawater, but normally, when the electric charge is passed, electrolysis occurs, and as a result, the ions in the seawater are generated as a gas. , The material that composes the undersea fence itself elutes. Since such a reaction also occurs when an alternating current is applied, it is necessary to use a corrosion-resistant metal material for the undersea fence.

Titanium is known as a metal having a high corrosion resistance in seawater. Titanium is stable in seawater during both anodic polarization and cathodic polarization, but its surface is passivated during anodic polarization. Moreover, since the passivated portion of the surface formed during anodic polarization is not necessarily reversible, it does not disappear during cathodic polarization, and the passivation gradually progresses even when an alternating current is applied, resulting in passivation. Due to the rectifying action of the film, the amount of current applied in one direction decreases, and the applied voltage also fluctuates. This phenomenon also appears for corrosion-resistant iron group elements or alloys thereof, although there are differences in the amount of consumption. As a method of preventing the passivation of titanium or the like during anodic polarization, it is effective to use a corrosion-resistant substrate such as platinum-plated titanium. As a result, it is possible to reduce the voltage, stabilize the applied current, and prevent the current from bending in one direction. However, since platinum plating deteriorates due to ripples and alternating currents and does not have sufficient durability, there is a problem not only when using alternating current but also when using direct current obtained by rectifying commercial alternating current.

Therefore, in the present invention, as a platinum group metal or metal oxide formed on a corrosion-resistant metal, a coating of a platinum group metal oxide selected from iridium, ruthenium, and rhodium is coated on a substrate such as titanium. It has been found that it can withstand high currents and is stable even when an alternating current is applied for a long time.

Furthermore, when an alternating current is applied to an undersea fence coated with an oxide of a metal of the platinum group selected from iridium, ruthenium and rhodium, there is an effect due to the capacity component of the coating itself, and the Because of the balance, electrolysis does not occur substantially and only electricity is applied.

That is, when alternating current is applied, anodic polarization and cathodic polarization are instantaneously repeated.
When electricity is applied to metals such as iron and nickel that form a conductor during anodic polarization, a passivation layer is formed on the surface during anodic polarization, and part of it is destroyed during cathodic polarization, and the passive layer is crossed over. Current flows. Then, during anodic polarization, the formation of a passive state layer is repeated, resulting in imbalance of current or fluctuation of voltage.

However, in the undersea fence having a coating containing an oxide of a metal of the platinum group of the present invention, current can be easily supplied even during anodic polarization, and no imbalance occurs during anodic polarization or cathodic polarization. Needless to say, further, in response to rapid repetition of positive and negative polarizations, the apparent current waveform is smoothed at a low voltage as if a smoothing circuit is provided, and no gas is generated. The present inventors call this phenomenon a phenomenon due to a capacitive component. For this reason, although the reason is unclear, electricity is being applied, and the hydrogen generated during negative polarization is consumed as a depolarizer during anodic polarization due to the extremely large catalytic activity of the coating components on the surface. It is understood that electrolysis is carried out in. Therefore, even if a considerably large voltage is applied, a large voltage is not applied to the subsea fence itself, so that stable energization can be performed for an extremely long period of time.

Therefore, the undersea fence of the present invention can be used stably because even if a voltage of 50 V or more is applied, the resistance of the surface is small and the undersea fence itself does not change due to a passivated state. Furthermore, since it becomes possible to apply a high voltage, it is possible to increase the interval between the subsea fences, reduce the number of installations, and reduce obstacles to the flow of seawater.

The undersea fence of the present invention uses a rod-shaped or plate-shaped member made of a metal or an alloy thereof having corrosion resistance in seawater such as titanium, or a member having a large surface area such as a mesh, expanded metal, or a perforated plate. be able to.

The platinum group metal or its oxide coating is
The surface of these base materials is subjected to treatment such as increasing the surface area by blasting or the like, followed by pickling and the like to activate the surface, and then a coating solution containing at least one platinum group metal salt is applied and dried. 40 in post air or oxidizing atmosphere
It is obtained by repeating the step of baking at 0 to 600 ° C. for 5 to 15 minutes until a coating having a desired thickness is obtained.

As the platinum group metal salt, ruthenium chloride, iridium chloride, rhodium chloride and the like are particularly preferable. By adding a solution of a salt of titanium or tin to the platinum group metal salt solution, a substrate is prepared. It is possible to form a strong coating on top. As these coating liquids,
Examples thereof include a mixed aqueous solution of titanium chloride with ruthenium chloride, iridium chloride, rhodium chloride and the like, a hydrochloric acid acidic alcohol solution with tin alkoxide and the like.

Corrosion-resistant substrates thus formed with a coating containing an oxide of a metal of the platinum group are installed at intervals as subsea fences, and a voltage is applied between adjacent subsea fences. The interval is 1 to 5 m, and a voltage of about 10 to 50 V can be applied.

It should be noted that there is no problem in setting the distance between the undersea fences to 1 m or less, but if the installation interval becomes short, the undersea fences and equipment for power supply required for installation at a fixed length will be provided. Many are required. If the interval is too large, the voltage to be applied becomes high, which is not practical, but the interval is preferably large to some extent in consideration of economical efficiency or influence of seawater flow on the seawater flow.

[0026]

The present invention provides a metal of the platinum group or its oxide as an undersea fence that gives an electric stimulus to a fish by forming an electric field in seawater to prevent the fish from entering or leaving a certain area. It uses a corrosion resistant metal that forms a coating containing, especially as an oxide of platinum group metal,
With a coating containing an oxide of a metal selected from ruthenium, iridium, or rhodium, it is possible to energize an alternating current, and it does not deteriorate even when a high voltage is applied. Can be large.

The present invention will be described in more detail below by showing Examples of the present invention.

[0028]

【Example】

Example 1 Two titanium rods having a diameter of 3 mm and a length of 1 m were prepared, the surface was blasted with # 70 grit to roughen the surface, and then pickled in 85 ° C. 25% sulfuric acid for 3 hours. It was

As titanium, ruthenium trichloride was added to an acidic solution of titanium trichloride containing 40 g / dm ³ in a molar ratio of 2:
Dissolve it to 1 and add hydrogen peroxide solution to oxidize it to make a reddish-brown coating liquid.
1 part of isopropyl alcohol for 10 parts by weight of coating solution
Added by weight.

This coating solution was applied to the titanium rod treated as described above, dried in air and then baked in air at 450 ° C. for 10 minutes. This operation was repeated 4 times to form a coating containing ruthenium oxide on titanium.

A titanium rod having a length of 1.2 m, a width of 6 m, and a depth of 1.2 m was attached to each of the wall surfaces of the titanium rod having the ruthenium oxide-containing coating so as to be divided into lateral walls of 3 m each. An alternating voltage of 10 V was applied to the titanium rod. The current density at the portion where the titanium rod was energized to seawater was 2 A / dm ² , and no generation of gas was observed from the undersea fence. This state was maintained for 3 months. There was no movement of fish across the undersea fence. When the state of the electrode after 3 months was examined, no decrease in coating was observed and mechanical strength was not abnormal at all.

[0032]

INDUSTRIAL APPLICABILITY The present invention provides a metal of the platinum group or its oxidation as an undersea fence for applying an electric stimulus to a fish by forming an electric field in seawater to prevent the fish from entering and leaving a certain area. It uses a corrosion-resistant metal that forms a coating containing a metal. Especially, as a platinum group metal oxide, a coating containing a metal oxide selected from ruthenium, iridium, or rhodium is used. Since it does not deteriorate even when a high voltage is applied, it is possible to increase the mutual distance between the subsea fences, reduce the number of installations, and have excellent economical efficiency and maintenance.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of installation of an undersea fence.

[Explanation of symbols]

 1 ... Submarine fence, 2 ... Power supply line

Claims (2)

[Claims] 1. A submerged fence for preventing fish from entering and leaving within a certain range by an electric field formed in seawater, characterized in that a surface of a corrosion resistant metal is coated with a platinum group metal or an oxide thereof. Undersea fence. 2. The undersea according to claim 1, wherein the coating contains an oxide of at least one platinum group metal selected from ruthenium oxide, iridium oxide, and rhodium oxide, and is capable of being energized with an alternating current. fence.