JPH11255187A - Soaked structure and contamination preventing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the adhesion and growth of aquatic organisms on and around a transparent wall and prevent the contamination of a desired surface over a long period by arranging a photocatalyst layer on the surface of the transparent wall. SOLUTION: In a soaked structure (structure) X such as petroleum drilling plant, marine observation tower, harbor facility or the like, support bases (b) are fixed to the sea bottom B by anchors (a), and vertical structural members (c) are raised on the support base (b) extending from the sea bottom to the atmosphere above a water level WL. A deck (d) is provided on the vertical structural materials (c), and a light converging part 1 is arranged on the upper end of each vertical structural material (c) near the deck (d). An orienting duct 2 for guiding the light taken by the light converting part 1 downward is laid in the inner part of each vertical structural material (c), and a light branching means 3 for branching the light and changing the light distributing direction of the light is provided in the middle of the orienting duct 2. Transparent walls 4 for monitoring and inspection are arranged in a plurality of positions on the outer surface of the vertical structural material (c), and a photocatalyst layer 5 is arranged on the outer surface of each transparent wall 4 to prevent the adhesion and growth of aquatic organisms.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-immersed structure and an antifouling method therefor, and more particularly to a photocatalytic reaction near a transparent wall of the structure to enhance the antifouling effect.

[0002]

2. Description of the Related Art As a ship or a marine structure, which is used in a water-immersed state, a steel material is coated and a component material is selected for corrosion prevention and measures.

[0003] When a submerged structure is provided with a transparent wall (such as a transparent viewing window) for underwater inspection monitoring and sightseeing,
If aquatic organisms such as algae adhere to the immersed surface, the transparency is impaired, so that it is necessary to periodically clean the outer surface.

[0004] As an antifouling method for components, for example, an organotin-based paint is applied to the surface of a steel material, and the toxic effect of the organotin-based paint is used to prevent marine organisms from adhering to the surface. Hindering techniques are employed.

[0005]

However, although heavy metals such as organotins are effective as antifouling agents, they are highly toxic to living organisms and have characteristics that are difficult to decompose spontaneously. It becomes a major factor of environmental pollution such as accumulation in sediment. On the other hand, the antifouling agent cannot be applied to the transparent wall, and if marine organisms such as barnacles or algae adhere to the surface of the transparent wall, they gradually grow over time. The cleaning work for securing the cleanliness of the wall is enormous.

[0006] The present invention has been made in view of the above circumstances, and achieves the following objects. To prevent aquatic organisms from adhering and growing, and to antifoul the desired surface. Reduce the effort to maintain cleanliness. Reduce energy for maintenance. Prevent marine environmental pollution.

[0007]

Means for Solving the Problems At least a part of the structure is arranged in a submerged state or in the vicinity of the water surface. The submerged state or the water surface in a marine structure, a port facility, a floating buoy, a ship, etc. fixed to the sea floor. In the antifouling technology in the vicinity, sunlight or natural light is taken in from the condensing part in the atmosphere, such as the deck of a structure that is located above the water surface, and the taken light is put below the structure. The light is guided by the light distribution duct, and the light is radiated through the transparent wall on the outer surface of the structure by the light distribution from the middle or the lower end of the light distribution duct, and the light is previously carried on the immersed surface of the transparent wall. by causing a photocatalytic reaction on the photocatalyst layer formed of TiO ₂ or the like had been killing aquatic organisms in the vicinity of the photocatalytic layer, the aim of prevention or decomposition accelerator breeding, in the vicinity of the surface of the transparent wall proof The performing techniques are employed. A convex lens or a concave mirror is used as the condensing portion, and a light distribution duct is a combination of a reflecting mirror, a conduit having a mirror-finished inner surface, a transparent resin plate, a transparent rod, or the like. A half mirror, a prism, or the like is used as means for splitting the light beam from the light distribution duct.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of an antifouling technique according to the present invention will be described below with reference to FIGS. FIG. 1 shows a first embodiment of an antifouling technique (water-immersed structure and its antifouling method) according to the present invention, and FIG. 2 shows an example of a structure when the water-immersed structure is a marine structure. , FIG.
3 shows a main part of the marine structure in FIG. 2.

A submerged structure (structure) X is an oil drilling plant, an underwater observatory tower, a port facility, or the like. A support b is fixed to a seabed B by an anchor a.
On the support b, the vertical structural material c is disposed in an upright state from the sea floor to the atmosphere above the water surface WL,
A deck d is provided in an upper portion of the vertical structural material c where the atmosphere becomes an atmosphere.

In the example shown in FIG. 2, a condensing unit 1 for taking in sunlight is disposed at the upper end of the vertical structural member c near the deck d.
And a light distribution duct 2 for guiding the received light rays downward is laid, and the light rays are branched in the middle of the light distribution duct 2 to change the light distribution direction (transmission) of the light rays, for example, horizontally. An optical branching means 3 for converting the direction is provided. Further, transparent walls 4 for monitoring and inspecting the state of the underwater or vertical structural material c while penetrating the wall of the vertical structural material c are disposed at, for example, a plurality of locations on the outer surface of the vertical structural material c. At the same time, a photocatalyst layer 5 for causing a photocatalytic reaction is disposed on the outer surface of the transparent wall 4.

In the example of FIG. 2, a convex lens or a concave mirror is used for the light collecting section 1, and a protective cover 1a for obtaining weather resistance and airtightness is mounted on the upper side thereof.

The upper part of the light distribution duct 2 has a condensing part 1.
And is arranged inside the vertical structural member c so as to be isolated from the surrounding environment, and directs sunlight or other natural light (light rays) taken in by the condensing section 1 downward to, for example, the sea floor B. One having a function of forming an optical transmission path for guiding is applied. The light distribution duct 2 has, for example, a hollow structure and a combination of a reflection mirror, a mirror whose inner surface is mirror-finished by a conduit having a rectangular cross section, or a transparent resin plate of acrylic or the like. , A transparent rod, a bundle of optical fibers, and the like are used.

The required number of the light branching means 3 are distributed in the middle of the light transmission path in the light distribution duct 2, and the light branched (distributed) from the light distribution duct 2 is converted outward in the horizontal direction. It is guided to the transparent wall 4 (or inward if necessary), and a half mirror, a prism, or the like is used. The position of the light branching means 3 is set to, for example, a position across a water surface WL serving as a draft line, a desired height position, a lower end position of the light distribution duct 2, and the like.

The transparent wall 4 is disposed on the outer surface of the immersed structure X (contact surface with seawater: immersed surface) so as to be exposed to seawater, and a photocatalyst layer 5 is disposed on the outer surface. In addition, when the light distribution duct 2 is hollow, the light distribution duct 2 has pressure resistance.

The photocatalyst layer 5 has a photocatalyst made of TiO ₂ or the like preliminarily supported on the water-immersed surface of the transparent wall 4. For example, TiO ₂ particles are coated so as not to impair the light transmittance. It is attached to a thin film or the like, and is formed on the inner surface of the transparent wall 4 as necessary.

With the water-immersed structure X having such a structure,
As shown in FIG. 1, when sunlight (or natural light) is obtained, the solar light (or natural light) is collected from, for example, a wide range from the light collecting unit 1 and collected, and the collected light is distributed to the light distribution duct 2. And the light is distributed in the horizontal direction by the light branching means 3 in the middle of the light distribution duct 2,
A light beam is applied to the photocatalyst layer 5 from the inside via the transparent wall 4.

When the photocatalyst layer 5 is irradiated with light, a photocatalytic reaction occurs in the photocatalyst layer 5 and adheres, floats or swims in the formation area of the photocatalyst layer 5 or in the vicinity thereof based on the strong oxidizing power at that time. The aquatic organisms that are killed or their reproduction and growth are significantly inhibited, and the adhesion of new pollutants (aquatic organisms and organic matter) is inhibited. In addition, under conditions where a sufficient amount of light (especially ultraviolet light) can be obtained, the action of decomposing the dead carcasses and fouling substances (organic substances) of attached aquatic organisms and reducing the size of the molecules occurs.
Antifouling of the transparent wall 4 and its vicinity is performed.

[Other Embodiments] The present invention also includes the following techniques. a) The present invention is applied to a structure in which only the vicinity of the light condensing unit 1 is arranged in the atmosphere. b) The present invention is applied to a structure in which the transparent wall 4 of the structure has an air atmosphere above the water surface WL. c) The light collecting section 1 is arranged on the entire surface of the deck d or a space above the deck d. d) Applying or using ultraviolet irradiation by an ultraviolet lamp to promote the occurrence of a photocatalytic reaction. e) From the end of the light distribution duct 2 such as the lower end, the light beam is transmitted to the transparent wall 4.
Apply technology to irradiate.

[0019]

According to the water-immersed structure and the antifouling method of the present invention, the following effects can be obtained. (1) By disposing a photocatalyst layer on the surface of the transparent wall,
It is possible to prevent aquatic organisms from adhering to and growing on the transparent wall and the vicinity thereof, and to prevent soiling of a desired surface. (2) Using a photocatalytic reaction to suppress the contamination of the transparent wall and decompose and remove the contaminants can reduce the labor for maintaining cleanliness. In addition, the photocatalytic reaction can be caused semipermanently, and the antifouling effect can be maintained for a long time. (3) By using sunlight or natural light, energy consumption during maintenance can be significantly reduced. (4) Since no antifouling agent is applied and no emission is released during antifouling, marine environmental pollution can be prevented. (5) The present invention is applicable to a structure that is at least partially in a state of being immersed in water or disposed near the water surface, and can perform surface antifouling of a wide range of marine structures and ships.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an application state of an antifouling technology according to the present invention to a marine structure in a first embodiment.

FIG. 2 is a front sectional view showing a structural example of the marine structure in FIG.

FIG. 3 is a front sectional view of a main part of the marine structure in FIG. 2;

[Explanation of symbols]

 X Water-immersed structure (structure) a Anchor b Support c Vertical structure d Deck WL Water surface B Seabed 1 Condenser 1a Protective cover 2 Light distribution duct 3 Light branching means 4 Transparent wall 5 Photocatalytic layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // C02F 1/32 C02F 1/32

Claims (6)

[Claims] At least a part of a structure (X) that is arranged in a state of being immersed in water or in the vicinity of a water surface, and is arranged in a portion of the structure that is in an air atmosphere to collect sunlight or natural light. A light distribution duct (2) connected to the light condensing part for guiding the light rays taken in downward, and a light beam distributed from the light distribution duct is irradiated outward to be carried on the surface; A water-immersed structure comprising a photocatalytic layer (5) and a transparent wall (4) for causing a photocatalytic reaction. 2. A light splitting means (3) for splitting a light beam and distributing the light to a transparent wall (4) in the middle of the light distribution duct (2). Submerged structure. 3. The submerged structure according to claim 1, wherein the submerged structure (X) is a marine structure fixed to the sea floor. 4. The water-immersed structure according to claim 1, wherein the water-immersed structure (X) is a floating structure floating on the water surface. 5. A method for antifouling a surface of a structure (X) which is at least partially immersed in water or located in the vicinity of a water surface, wherein the light condensing part (1) is exposed to the atmosphere of the structure. ), The solar light or natural light is taken in, the light is guided by the light distribution duct (2) below the structure, and the light is irradiated from the light distribution duct to the transparent wall (4) on the outer surface of the structure to form a transparent wall. An antifouling method for a water-immersed structure, comprising performing a photocatalytic reaction on a photocatalyst layer (5) carried on the surface to perform antifouling near the surface of the transparent wall. 6. The water according to claim 5, wherein the light distribution duct guides the light downward, and splits the light in the middle of the light distribution duct to distribute the light to the transparent wall. Antifouling method for pickled structures.