Description ANTI-FOULING AND ELIMINATING SYSTEM AGAINST AQUATIC ORGANISMS Technical Field [1] The present invention relates to an anti-fouling and eliminating system against aquatic organisms, and more particularly, to an anti-fouling and eliminating system against aquatic organisms, which can prevent aquatic organisms from being attached to a marine structure and can eliminate the aquatic organisms themselves, thereby extending lifetime of the marine structure and facilitating a maintenance and repair work of the marine structure.

Background Art [2] In general, marine structures, such as ships, provide an ideal environment for attachment and inhabitation of aquatic organisms, and it is quite difficult to achieve anti-fouling and elimination of such aquatic organisms. Several anti-fouling means or methods have been conventionally employed, including use of copper ions and hypochlorite method. However, techniques for eliminating aquatic organisms in a ballast tank of a ship have not yet been developed.

[3] Specifically, the anti-fouling means or method using copper ions employs seawater electrolytic technique for formation of copper ions. Although copper ions are able to effectively chemically sterilize aquatic organisms attached to marine structure, they may undesirably accumulate in the human body by eating fish containing the toxic ions. Also, copper ions may result in seawater contamination. Since anti-fouling systems using copper ions require a large amount of copper metals, the maintenance and replacement cost disadvantageously increases.

[4] According to hydrocholite formation technique, chloride contained in seawater in a considerable amount is converted into hypochlorous acid by electrolysis to destroy aquatic organisms attached to a marine structure. However, the use of such hypochlorite formation technique has been strictly restricted because it makes a problem that even microorganisms useful to the ecosystem are extirpated.

[5] In the meanwhile, there is a serious problem that the marine ecosystem might be endangered due to migration of detrimental planktons, larvae or spawn of aquatic organisms through ballast water as a medium.

Disclosure of Invention Technical Solution [6] To solve the above problems, it is an objective of the present invention to provide an anti-fouling and eliminating system against aquatic organisms, which can prevent attachment of aquatic organisms to a marine structure, and can selectively eliminate the attached aquatic organisms, detrimental planktons, larvae or spawn.

[7] To achieve the object of the present invention, there is provided an anti-fouling and eliminating system against aquatic organisms comprising one or more anode and cathode terminals installed at a portion of a marine structure, and at least one pulse generator electrically connected to the anode and cathode terminals.

[8] Pulses generated from the pulse generator are direct-current (DC) pulses having an instantaneous potential difference (V) of 100 volts and sustaining for a period of 1 a nanosecond to 1 millisecond.

[9] The anode and cathode terminals are installed at a seawater inlet of the marine structure connected to a pipe line or ballast tank.

[10] The anode and cathode terminals may be installed on an internal wall of the pipe line for inducing seawater into the marine structure.

[11] Alternatively, the anode and cathode terminals may be installed in a river and supported by buoys in a floating state.

[12] Pulses generated from the pulse generator are alternating-current (AC) pulses having a potential difference Vb ranging from about 4 to 10 volts and a frequency ranging from about 3 kHz to 3 MHz.

[13] The anode and cathode terminals are installed at a surface of the marine structure contacting seawater.

[14] The anode terminals may be shared by an anode based on forcible current applying mechanism.

[15] The anode and cathode terminals are installed inside and outside a fish farm in parallel.

[16] Also, the anode and cathode terminals are installed on an internal wall of a seawater inlet pipe introduced to a land fish farm.

Description of Drawings [17] HG. 1 is a reference diagram illustrating a state of ions in a non electrolyte; [18] HG. 2 is a reference diagram illustrating a state of ions in an electrolyte; [19] HGS. 3A and 3B are graphs illustrating time-dependent changes in voltages applied to an electrolyte; [20] HG. 4 is a schematic cross-sectional view illustrating an embodiment in which the system of the present invention is installed at a seawater inlet of a marine structure; [21] HG. 5 is a cross-sectional view schematically illustrating an embodiment in which the system according to the present invention is installed at a pipe line of a marine structure; [22] HG. 6 is a cross-sectional view schematically illustrating an embodiment in which the system according to the present invention is installed at a pipe line provided in an entry of a river; [23] HG. 7 is a cross-sectional view schematically showing an embodiment in which the system according to the present invention is installed on a surface of a marine structure; [24] HG. 8 is a cross-sectional view schematically showing a modified embodiment in which the system according to the present invention is installed on a surface of a marine structure; [25] HG. 9 is a plan view schematically showing that the system according to the present invention is installed on a marine fish farm; and [26] HG. 10 is a plan view schematically showing that the system according to the present invention is installed on a land fish farm.

Best Mode [27] Hereinafter, the present invention will be described in detail with reference to the attached drawings.

[28] HG. 1 is a reference diagram illustrating a state of ions in a non electrolyte, and HG. 2 is a reference diagram illustrating a state of ions in an electrolyte. Referring to HG. 1, if an electromagnetic field is established in a nonelectrolyte 12, an arbitrary object 10 in the electromagnetic field is polarized. In this case, since there are no charges outside the object 10 in the electromagnetic field, negative (-) poles of the charges are directed toward an anode terminal 15, and positive (+) poles are directed toward a cathode terminal 17. The object 10 in the electromagnetic field usually migrates toward a strong electromagnetic field area, producing a pulling capacity. If an electromagnetic field is established within an electrolyte 22, polarized particles present within the highly movable electrolyte 22 are pulled toward the opposite polarity.

Referring to HG. 2, positive (+) poles of the object 20 are directed toward an anode terminal 25, and negative (-) poles are directed toward a cathode terminal 27. In other words, negative (-) polarities opposite to positive (+) polarities of the anode terminal 25 are formed in a direction from the outside of the object 20 to the anode terminal 25, and positive (+) polarities opposite to those of the cathode terminal 27 are formed in a direction of the cathode terminal 27. Accordingly, a transmembrane potential is generated between the inside and outside of the object 20. If the transmembrane potential exceeds 1 volt, pores are produced on a membrane of the object 20. for example, if an organism, instead of the object 20, is present within the electrolyte 22, cellular membranes of the organism can be disintegrated by a change in the polarity and an increase in the transmembrane potential.

[29] HGS. 3A and 3B are graphs illustrating time-dependent changes in voltages applied to an electrolyte. HG. 3A illustrates a change in voltages applied for disin- tegrating a cellular membrane of an organism. Here, pulses applied to the organism have an instantaneous potential difference V of 100 volts and are DC pulses sustaining a for a time t of 1 nanosecond to 1 millisecond. Such electromagnetic impact applying a methods can be advantageously employed to applications where tubular structures such as pipes or ducts are installed. Referring to HG. 3B, AC pulses having a potential difference V ranging from about 4 to 10 volts and a frequency ranging from about 3 b kHz to 3 MHz are applied to the organism in the electrolyte. Applying such AC pulses cannot disintegrate the cellular membranes of the organism, but can disturb the sensory system of the organism to be in an unstable state. This method can be applied to marine structures, such as anchoring ships, marine power plants or fishing nets in a fish farm, to prevent attachment of organisms to such marine structures.

[30] Anti-fouling and elimination of aquatic organisms will be described in sequence through embodiments using pulse generators of generating DC pulses shown in HGS.

3A and AC pulses shown in HG. 3B, and selectively generating DC pulses or AC pulses, respectively.

[31] HGS. 4 through 6 are cross-sectional views schematically illustrating marine structures having anti-fouling and eliminating system for aquatic organisms according to embodiments of the present invention, in which DC pulses shown in HG. 3A are used. HG. 4 is a schematic cross-sectional view illustrating an embodiment in which the system of the present invention is installed at a seawater inlet of a marine structure.

In more detail, an anode terminal 45 and a cathode terminal 47 are installed at a seawater inlet 43 of a marine structure 40 to disintegrate aquatic organisms induced into the seawater inlet 43 with seawater 32. In the illustrative embodiment, the seawater 32 is used as engine cooling water of the marine structure 40 or ballast water.

A pulse generator 49 installed in the marine structure 40, generates pulses having an instantaneous potential difference V high enough to disintegrate cellular membranes a of the aquatic organisms, as shown in HG. 3A. Accordingly, the aquatic fouling organisms and detrimental planktons, larvae or spawn contained in the seawater 32 induced to the marine structure 40 are disintegrated such that bores are created through the cellular membranes thereof. In the illustrative embodiment, an anode terminal 45 and a cathode terminal 47 installed at the seawater inlet 43, directly contact the seawater 32 acting as an electrolyte, and are electrically connected to a pulse generator 49. A seawater inlet 43 is connected to a pipe line 44 and/or a ballast tank (not shown).

Undefined reference numeral 31 denotes a seawater surface.

[32] HG. 5 is a cross-sectional view schematically illustrating an embodiment in which the system according to the present invention is installed at a pipe line of a marine structure, such as a power plant, oil prospecting rig or ballast tank. According to this embodiment, an anode terminal 55 and a cathode terminal 57 are installed on an internal wall of a pipe line 54 to disintegrate the aquatic organisms, detrimental planktons, larvae or spawn contained in the seawater 32 induced to the marine structure 40 when the seawater 32 used as cooling water or ballast water is induced to the marine structure. In the illustrative embodiment, like in the embodiment shown in HG. 4, pulses having a high instantaneous potential difference V are used, and an ex- a planation thereof will not be given. An anode terminal 55 and a cathode terminal 57, installed on the internal wall of the pipe line 54, directly contact the seawater 32 acting as an electrolyte, and are electrically connected to a pulse generator 59.

[33] HG. 6 is a cross-sectional view schematically illustrating an embodiment in which the system according to the present invention is installed at a pipe line provided in an entry to a river, in which an anode terminal 65 and a cathode terminal 67 are installed on a pipe line 64 disposed at a river bed 60. Buoys 63 having buoyancy are installed at the anode terminal 65 and the cathode terminal 67, so that the anode terminal 65 and the cathode terminal 67 are supported on the pipe line 64 in a floating state. Ac- cordingly, DC pulses shown in HG. 3A are generated by a pulse generator 69 installed on land to eliminate hazardous plankton contained in the river 62, which may have a deleterious effect on the ecosystem of the river, thereby preventing the green tide due to toxic plankton.

[34] HGS. 7 and 8 illustrate an anti-fouling and eliminating system for aquatic organisms according to the present invention, the system being adapted to generate AC pulses. HG. 7 is a cross-sectional view schematically showing an embodiment in which the system according to the present invention is installed on a surface of a marine structure. In the illustrative embodiment, an anode terminal 75 and a cathode terminal 77 are installed on a surface of a marine structure 70 contacting seawater 32 and are electrically connected to a pulse generator 79. As shown in the drawing, when the anode terminal 75 and the cathode terminal 77 are installed on the surface of the marine structure 70, the anode terminal 75 and the cathode terminal 77 are submerged in the seawater 32 underneath the seawater surface 31. In this case, disturbance is caused to the sensory system of aquatic organisms or plankton by generating the AC pulses shown in HG. 3B, potentials of which are continuously changed, thereby preventing the aquatic organisms or plankton from being attached to the surface of the marine structure 70.

[35] HG. 8 shows an embodiment similar to that shown in HG. 7, in which an anode terminal 85 and a cathode terminal 87 are installed on a surface of a marine structure 80 and submerged in seawater 32 underneath the seawater surface 31, and are electrically connected to a pulse generator. In the illustrative embodiment, the anode terminal 85 may be separately installed, or may be shared by an anode based on forcible current applying mechanism. A surface of the marine structure 80 may be used as the cathode terminal 87. Alternatively, a cathode may be separately provided.

[36] HGS. 9 and 10 show other embodiments of the anti-fouling and eliminating system according to the present invention, in which DC pulses or AC pulses are selectively generated for anti-fouling and eliminating purposes. In detail, HG. 9 is a plan view schematically showing that the system according to the present invention is installed on a marine fish farm. In the illustrative embodiment, a plurality of anode terminals 95 and 96 and a plurality of cathode terminals 97 and 98 are installed inside and outside a fish farm 90 in parallel. A pulse generator 99, which is connected to the anode terminals 95 and 96 and the cathode terminals 97 and 98, is adapted to selectively generate the DC pulses shown in HG. 3A or the AC pulses shown in HG. 3B. Thus, aquatic organisms can be prevented from being attached to a fishing net of the fish farm 90 or can eliminate plankton that is harmful to fish farming.

[37] HG. 10 is a plan view schematically showing that the system according to the present invention is installed on a land fish farm, where an anode terminal 105 and a cathode terminal 107 are installed on a seawater inlet pipe 104 introduced to a land fish farm 100. In the illustrative embodiment, like in the embodiment shown in HG. 9, DC pulses or AC pulses are selectively used to eliminate plankton that is harmful to fish farming, and ultimately prevent the red tide due to toxic plankton. In the il- lustrative embodiment, a pulse generator 109 is connected to the anode terminal 105 and the cathode terminal 107 using a separate support structure (not shown).

[38] The present invention is not intended to be limited to the embodiments described above, and many modifications alterations may be effected within the scope of the appended claims. For example, for the purpose of facilitating transmission of pulses, the anode and cathode terminals described in the illustrative embodiments may be panel-or rod-shaped.

Industrial Applicability [39] According to the present invention, cellular membranes of aquatic organisms or plankton induced into a marine structure can be disintegrated by applying pulses having a high instantaneous potential difference. Also, the aquatic organisms can be prevented from being attached to a marine structure by applying pulses with potentials continuously varying. Further, aquatic organisms can be selectively disintegrated by controlling pulse generation, rather than by using chemical methods, suggesting that the anti-fouling and elimination system for aquatic organisms can be implemented in an environmentally friendly manner. Also, since attachment of aquatic organisms to a marine structure, which may cause fouling, is prevented, the life of the marine structure can be extended. Since the anti-fouling and eliminating system for aquatic organisms is simplified, a repair and maintenance work thereof can be easily made.

Further, destruction of the marine ecosystem, resulting from regional, national or in- ternational migration of detrimental planktons, larvae or spawn of aquatic organisms present in a ballast tank, can be avoided.