JP2004081119A - Method for carrying out removal and antisticking of aquatic organism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an effective method and apparatus for carrying out antisticking and removal of aquatic organisms at a low cost without using any chemical. <P>SOLUTION: The method for carrying out antisticking and removal of these aquatic organisms comprises arranging electrodes in the neighborhood in which an object from which adhesion of the aquatic organisms is prevented or the aquatic organisms attached to the object is irradiated with shock wave and ultraviolet light generated accompanying pulse discharge and directly irradiating the aquatic organisms with the shock wave and ultraviolet light generated accompanying the discharge by generating the pulse discharge on electrodes. When carrying out pulse discharge, it is preferable that bubbles exist in water near electrodes and a reflecting body having a structure reflecting either one or both of the shock wave and the ultraviolet light generated by the pulse discharge is used. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention uses a pulse discharge in the water, a power plant intake channel or an aquarium intake facility, a ship bottom, a dike or seawall, a fish net such as a fish cage or a stationary net, and shellfish and algae attached to fishing gear such as a float. It relates to the prevention or removal of aquatic organisms such as bacteria.
[0002]
[Prior art]
Purple mussels and barnacles adhere to the intakes of power plants and waterfront plants, causing problems such as reduced intake flow rates, corrosion of condenser pipes, and reduced heat transfer performance. If it adheres to the bottom of the ship, the smooth bottom of the ship will have unevenness, which will not only increase friction and slow down the stern, but also reduce fuel consumption and increase the amount of exhaust gas. It leads to encouragement. For this reason, the shellfish are regularly removed by some method, but the cost of disposal of the removed shellfish and the generation of offensive odors from the dead bodies are serious problems.
[0003]
In addition, these organisms and seaweed attached to fixed nets and fish nets also block the mesh, increasing the fluid resistance due to the ocean current and increasing the load on the mooring facility.If the anchoring force of the anchor is not sufficient, the net will shift. Not only that, there is also a case where the inflow and outflow of seawater in the net is prevented, and the death of cultured fish or the like due to the lack of oxygen in the seawater in the net may cause a large loss.
[0004]
For this reason, these aquatic organisms such as barnacles, mussels, diatoms / seaweeds, oysters, ascidians, and hydroids have been conventionally subjected to anti-adhesion and removal measures. The methods of chlorine injection and organotin coating have been used most frequently, but the amount and use of the injection have been significantly regulated from the viewpoint of environmental protection, and various alternative methods have been attempted at present. As a method for numbing the larva during the attachment stage, chemicals (ClO ₂ , bromine, bromine compound, NaBr, ozone, hydrogen peroxide, surfactant, cupric chloride, electrolytic copper ions), base coating (copper oxide, copper) , Base materials (copper, cupronickel, copper beryllium alloy, special concrete), and other physical methods (ultrasonic, high frequency, laser, ultraviolet, infrared, microwave, heating, lack of oxygen) There are methods for preventing ferrous ions, such as ferrous ions, semiconductor photocatalysts, sound waves, magnetic fields, light, and repellents. As a method of removing living matter that has already adhered, there are a peeling operation by a robot or a diver, a high-speed flow, a physical peeling of a brush, a sponge ball, and the like.
[0005]
It has been proposed to install a DC pulse generator to prevent underwater organisms from invading through waterways installed at intakes and drains of hydropower plants and to prevent shellfish from adhering to the walls of the waterways. However, this caused an electric shock to aquatic organisms and shellfish, and was less effective. Also, in the same field, a method has been proposed in which an intermittent sound of 200 Hz or less is generated in water to induce growth inhibition and / or repellent behavior in aquatic organisms. Although arc discharge is used, the pulse voltage for this purpose is supplied to the sound generator, and is intended to control aquatic organisms using the action of sound waves that are well transmitted in water. Was.
However, there are still no definitive methods for many of the above-mentioned methods, such as those whose effects are ambiguous, the methods are very expensive, and those which harm other organisms. For this reason, a method of not attaching organisms without affecting the environment and a method of removing attached organisms have been desired.
[0006]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a method for preventing and removing aquatic organisms which is effective at overcoming the problems of the prior art and using a low cost without using chemicals.
[0007]
[Means for Solving the Problems]
The inventors have found that by performing pulse discharge in water to generate ultraviolet rays and shock waves and directly irradiating them to the target object, it is possible to prevent and remove the adhesion of shellfish and algae attached to the intake channel and fishing gear. Thus, the present invention has been completed. That is, the above object is achieved by the following configuration.
[0008]
(1) In water, an electrode is arranged in the vicinity of an object to be prevented from adhering to aquatic organisms or an aquatic organism attached to the object, which is directly irradiated with shock waves and ultraviolet rays generated by pulse discharge. A method for preventing and removing aquatic organisms, wherein a pulse discharge is generated at an electrode, and shock waves and ultraviolet rays generated by the discharge are directly applied to the aquatic organism.
(2) The method for preventing and removing aquatic organisms according to (1), wherein bubbles are present in water near the electrodes when the pulse discharge is performed.
(3) The method according to (1), wherein a structure is provided around the electrode to reflect shock waves and ultraviolet rays generated by the pulse discharge, and a reflector is provided to give directionality to the shock waves and ultraviolet rays. Prevention and removal of aquatic organisms.
[0009]
(4) For a target to which aquatic organisms should be prevented from adhering in water or an aquatic organism adhering to the target, a pulse discharge electrode arranged near the target, a power supply for generating pulse discharge, and a shock wave are generated. A control device for controlling a discharge voltage, a discharge energy, a discharge interval, a distance between electrodes, and the like of a pulse discharge, and a lead wire for connecting the electrode to the power source. Prevention and removal of aquatic organisms. apparatus.
[0010]
That is, the gist of the present invention is as shown below.
1) An adhesion prevention / removal method characterized by performing pulse discharge in water.
2) An adhesion prevention / removal method characterized by disposing an electrode near an aquatic organism and directly applying a shock wave generated by pulse discharge.
3) An adhesion prevention / removal method characterized by disposing an electrode in the vicinity of aquatic organisms and directly applying ultraviolet light generated by pulse discharge.
4) The method for preventing and removing adhesion according to 2), wherein unnecessary shock waves are absorbed by using bubbles.
5) A method for preventing and removing adhesion by underwater pulse discharge, comprising an underwater electrode having a structure that reflects shock waves and ultraviolet rays.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
The pulse power source used in the present invention is an electrostatic energy storage type using a capacitor, an induction energy storage type using a coil, a kinetic energy storage type using a steam turbine or a flywheel, a chemical energy storage type using an explosive, and the like. Although not particularly limited, it is more desirable to use an inductive energy storage type that is small and has good controllability.
In the present invention, in order to simultaneously generate shock waves and ultraviolet rays for aquatic organisms by pulse discharge, the discharge voltage is, for example, about 5 kV and the energy is about 1.3 kJ. Further, as the shock wave to be generated, when the irradiation target is a cell, it is destroyed at several MPa to 10 MPa, and when it is a shell, it is destroyed at several tens MPa to several 100 MPa. It is preferable to set the following conditions. Furthermore, the distance to make the electrode close to the aquatic organism varies depending on the type of the aquatic organism and the magnitude of the discharge voltage and the discharge energy. When the aquatic organism is a mussel, for example, 80 mm or less, preferably 40 mm or less. .
[0012]
Hereinafter, the present invention will be described in detail with reference to the drawings.
In all the drawings for describing the embodiments and the examples, components having the same functions are denoted by the same reference numerals.
[0013]
The pulse discharge device most suitable for preventing adhesion has, for example, a structure as shown in FIG. This apparatus comprises a computer 1, a pulse power supply 2, an underwater discharge electrode 3, and a high-voltage cable (electric cable) 4 for connecting each of them. The computer 1 controls a discharge voltage, a discharge energy, a discharge interval, a distance between electrodes, and the like.
[0014]
The underwater electrode 3 is immersed in the vicinity of a place where organisms are attached, and discharge is performed directly from the ship or from the quay or by attaching a float. Shock waves are generated by the discharge, and the attached organisms are crushed or peeled off together with the biological film that forms the basis of the organism attachment. For this reason, it becomes difficult for the organisms to adhere after the treatment, and an effect of preventing the adhesion appears. In addition, the ultraviolet rays generated simultaneously with the shock wave kill the microorganisms on the attached surface, so that the growth of the biological film is suppressed. This effect also increases the effect of preventing adhesion. In the present invention, the embodiment is not limited to a configuration in which the electrode 3 is directly arranged in water. Since the present invention is excellent in controllability, it is possible to perform a partial cleaning and an appropriate operation depending on a difference in aquatic organisms by changing a discharge voltage, a discharge energy, and the like.
[0015]
FIG. 2 shows an example in which the present invention is applied to the cleaning of a fish net. The computer 1 and the pulse power source 2 and the air diffuser compressor 5 shown in FIG. 1 are installed on the pier above the fish cage, and the underwater electrode 3 is immersed from the pier to the side of the net where the organisms are attached. The air diffuser 7 is attached to the fish side, and pulse discharge is performed while air is diffused using the air hose 8. The diffuser 7 may be of a fixed type. In this method, since the treatment can be performed only by immersing the underwater electrode 3 in water, new special equipment is not required. If the entire power supply unit is mounted on a trolley or ship, it can be easily moved and operated remotely. In addition, since it operates with low power, a power supply supplied from a fishing boat or the like is sufficient, and when it is used for a fixed net or the like, power can be supplied by a solar cell or wind power generation.
[0016]
In FIG. 2, bubbles are made to exist using a diffuser, but it is known that in the presence of bubbles 9, bubbles 9 absorb the energy of shock waves and ultraviolet rays in water. When useful organisms such as fish are bred inside a fish net, it is very difficult to diffuse air on the opposite side of the underwater electrode 3 when removing attached organisms and use the bubbles 9 as a protective barrier. It is valid. In addition, as shown in FIG. 3, by arranging the reflector 10 having a paraboloid or an ellipsoid behind the underwater electrode 3, it is possible to give directionality to the generated shock waves and ultraviolet rays, and to a necessary portion. The impact can be made efficiently. By processing the surface of the reflection plate 10 into a mirror surface such as by polishing, it is possible to efficiently irradiate ultraviolet rays as well as shock waves.
[0017]
【Example】
Hereinafter, the present invention will be described with reference to examples. However, the present invention is not limited to only these examples.
[0018]
(Example 1)
As shown in FIG. 4, a rock 11 to which barnacles were attached was collected from the shore, and a mussel mussel removal test according to the present invention was performed. A rock piece 11 (about 10 cm × 10 cm × 3 cm) to which artificial seawater 13 and a large number of mussels 14 having a body length of about 30 mm adhere are placed in a water tank 12 having an inner volume of 30 liters, and the distance from directly above the rock 11 is 40 mm and 80 mm. Alternatively, the electrode was changed to 160 mm, the stainless steel rod electrodes 3 of 6 mm were arranged to face each other, a discharge was performed at a discharge voltage of 5 kV and an output of 1.3 kJ, and a removal effect test of the mussel 14 was performed by changing the number of discharges. . The distance between the electrodes at that time is 2 mm. In this case, stainless steel SUS304 was used for the underwater electrode 3, but in an actual corrosive environment of seawater, a salt-resistant metal such as titanium or SUS329J1 is preferable.
[0019]
When the distance between the mussel 14 and the electrode 3 was 40 mm, the mussel 14 around the electrode 3 was completely dropped from the rock 11 by one discharge. Most of those that had fallen had severely broken outer shells. In many cases, the mussels of the fallen peripheral portion were partially damaged in the outer shell. After the second discharge, the peripheral mussel 14 was destroyed as the number of discharges increased, and only a part of the mussel 14 adhered to the edge of the rock 11 four times. When the distance from the electrode 3 was 80 mm, the effect was less than when the distance was 40 mm, and the number of times of complete destruction was 10 times, and when the distance was 80 mm, the number of times was 24 times. Since the shock wave attenuates as the distance from the discharge point increases, the effect seems to decrease with distance.
[0020]
【The invention's effect】
In the present invention, when a pulse discharge is performed in the vicinity of an object that prevents the attachment of aquatic organisms in water or aquatic organisms attached to the object, and strong ultraviolet rays and shock waves are generated by the pulse discharge in water, the shock wave is Aquatic organisms with a hard shell can be crushed because they reach several thousand atmospheres. In addition, since the intensity of ultraviolet light is much higher than the intensity of an ultraviolet lamp usually used for sterilization, it is possible to sterilize microorganisms attached to seawater containing many impurities. Since the present invention does not use chemicals as compared with the conventional methods for preventing and removing adhesion, there is no risk of chemically contaminating living organisms such as fish and shellfish which live in nature. When used in facilities for edible fish and shellfish such as fish nets and fixed nets, the freshness of the fish and shellfish is not reduced since there is no chemical contamination.
Since physical action such as ultraviolet rays and shock waves are used, resistant bacteria cannot be formed unlike chemical means, and there is no difference in the effect of preventing and removing adhesion even in regular work.
[0021]
When applied to fishing gear, work on land is not required. In the conventional onshore removal work, there are problems such as lifting fishing gear, removal work, and antifouling treatment after the removal work. This is advantageous in terms of cost. In addition, when lifting a fishing gear to which a large amount of organisms have adhered, it is not necessary to pay attention to breakage such as breakage of the net because the weight is larger than usual.
[0022]
In the removal of the organisms attached to the fish net and the fixed net, it is possible to remove the fish in the water while keeping it raised, and there is no fear that the fish will be killed or escaped by the fish. In addition, since the shock wave acts instantaneously even if the fishing gear is not fixed to the ground and is only suspended by the float, the dandruff generated by mechanical separation work such as divers and robots Does not matter).
[0023]
Ultraviolet rays generated by the discharge not only kills aquatic microorganisms but also kills microorganisms around the underwater electrodes, and is thus effective in preventing fish diseases in aquaculture. In addition, as an alternative to the underwater speaker used in a marine ranch or the like, it can be used as a sound source for fish and also serves to remove and prevent aquatic organisms.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view for explaining an embodiment of the principle of removing and preventing an organism from attaching according to the present invention.
FIG. 2 is a schematic explanatory view illustrating an embodiment of a method for removing and preventing an organism from attaching to a fish tool according to the present invention.
FIG. 3 is an explanatory view of an embodiment in which a reflector is provided on an underwater electrode according to the present invention.
FIG. 4 is a schematic explanatory view of a mussel mussel removal experiment according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Computer 2 Pulse power supply 3 Underwater electrode 4 High voltage cable 5 Compressor 6 Fishing net with aquatic organisms 7 Air diffuser 8 Air hose 10 Reflector 11 Rock 12 Water tank 13 Artificial seawater 14

Claims (4)

In the water, an electrode is arranged in the vicinity of the object to be prevented from attaching aquatic organisms or the aquatic organism attached to the object, where the shock waves and ultraviolet rays generated by the pulse discharge are directly irradiated, and the pulse is applied by the electrode. A method for preventing adhesion and removal of aquatic organisms, comprising generating a discharge and directly irradiating aquatic organisms with shock waves and ultraviolet rays generated by the discharge. The method for preventing and removing aquatic organisms according to claim 1, wherein bubbles are present in water near the electrodes when the pulse discharge is performed. The aquatic organism according to claim 1, wherein the electrode has a structure for reflecting a shock wave and an ultraviolet ray generated by the pulse discharge, and a reflector for giving a direction to the shock wave and the ultraviolet ray is provided around the electrode. Adhesion prevention and removal methods. A pulse discharge electrode, a power supply to generate pulse discharge, and a pulse discharge An apparatus for preventing and removing aquatic organisms, comprising: a control device for controlling a discharge voltage, a discharge energy, a discharge interval, a distance between electrodes, and the like, and a lead wire for connecting the electrode to the power supply.

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