JPH04150985A - Structure and method for preventing fouling of organism in sea water - Google Patents

Abstract

PURPOSE:To eliminate the elution of a contaminant and to prevent the fouling of a marine organism to the surface of a body by constituting the title structure of a vibration film covering the surface comming into contact with seawater and a drive means finely vibrating the vibration film. CONSTITUTION:The surface of the cooling water taking-in port of a power plant designated as a body for preventing the fouling of an organism is coated with a vibration film 2 composed of a substance having rubbery elasticity. It is necessary to entirely coat the surface comming into contact with seawater 3 of the vibration film 2. There is a submerged speaker 4 as the drive means vibrating the vibration film 2 composed of a rubber elastomer but any one generating vibration waves in water may be used. As the vibration film, there is a rubber elastic member, a member wherein a film itself is vibrated by the application of an electric signal or one having a member vibrated by applying an electric signal to a rubber elastic part partially embedded therein. As the member wherein the film itself is vibrated, there is a vibration film composed of lead titanate zirconate (PZT) and this PZT generates bending vibration action by an electric signal generated by the flow of a current.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a structure and method for preventing marine organisms from adhering to, for example, a cooling water intake of a power plant. It goes without saying that the present invention can be used not only in seawater but also in freshwater such as rivers, lakes, and marshes, where living things are attached.

(Prior Art) It is well known that, for example, in a power plant, the surface of a cooling water intake submerged in the sea becomes contaminated by adhesion of sea creatures such as barnacles, oysters, mussels, and seaweeds.

Therefore, as a conventional method for preventing the adhesion of marine organisms in the sea, the use of certain toxic compounds, so-called antifouling agents, that kill or repel marine organisms, such as the antifouling paints applied to ships, etc. This combination prevents the adhesion of such organisms.

(Problem to be Solved by the Invention) However, the antifouling paints containing toxic or repellent compounds that have been conventionally used to prevent the adhesion of marine organisms cannot prevent the adhesion of marine organisms by the active ingredients eluted from the coating film. However, the problem is that it becomes a source of pollution, and at the same time, it has a so-called lifespan in which it no longer exhibits an antifouling effect after the active ingredients are eluted.

Furthermore, in recent years, it has become a problem that these antifouling agents accumulate in fish and shellfish through the natural food chain. , which may cause the above-mentioned pollution problem, and alternatives to these antifouling agents are currently being considered.

Incidentally, the staining of the surface of an object by marine organisms progresses as countless larvae of marine organisms floating or swimming in the sea come into contact with the surface of the object, secrete a special type of mucus, settle on the surface, and then grow.

In general, it is said that the larvae of these marine creatures have difficulty attaching to unstable surfaces, such as objects whose surfaces are covered with a cilia-like membrane, and the surface of the object to which they are trying to attach is constantly moving. It is said that it does not easily adhere to objects.

The inventors focused on this point and completed the present invention by discovering that an antifouling effect can be exerted by constantly vibrating the surface of an object at the time when larvae of marine organisms are about to land on the surface of the object.

The object of the present invention is to provide a structure and structure for preventing the adhesion of marine organisms to the surface of objects, in which no antifouling agent is eluted from the surface of the sea, etc., and which does not affect the marine ecosystem. The purpose is to provide a method.

(Means for Solving the Problems) The first feature of the present invention is to provide a vibrating membrane that covers at least the surface of an object that comes into contact with seawater or the like to prevent attachment of living things; It consists of a driving means that causes slight vibrations.

A second feature is that the surface of the member that prevents the attachment of living organisms that comes into contact with seawater or the like is slightly vibrated.

The above-mentioned vibrating membrane includes a rubber elastic member, a member that vibrates itself when an electric signal is applied, and a rubber elastic part in which a member that vibrates when an electric signal is applied is partially embedded.

In addition, this rubber elastic member has a rubber hardness of 80 or less and an elongation rate of 1.
00% or more.

For example, rubber materials such as natural rubber, butyl rubber, chloroprene rubber, butadiene rubber, styrene-butadiene rubber, nitrile-butadiene rubber, and isoprene rubber. Urethane resin materials are reaction products of isocyanates and resins such as polyols, polyamines, polythiols, and epoxy resins.

Epoxy resin material is a reaction product of elastic Epoquine resin and polyamine or polyamine with elastic molecular structure.

Single or polyorganosiloxane resin (silicone resin) materials using dimethyl, methylvinyl, phenyl, methylphenylvinyl, fluoro, or modified silicone rubber with other organic segments bonded. Combinations of other low viscosity resins (coumarone resin, xylene resin, silane coupling agent, silicone oil, etc.) can be used.

It is also possible to use a sponge-like material made by foaming the resin material.

Another example of a member that vibrates itself when an electric signal is applied is a vibrating membrane made of lead zirconate titanate (PZT), which causes a bending vibration effect when an electric current is passed through it. It is.

The energy source of the drive means that gives the micro-vibration is an underwater vibration wave that is generated by applying an electric signal to a vibrating membrane that vibrates when an electric signal is applied, or an underwater vibration wave that impacts the object to be antifouled. The above driving means has a frequency for vibrating the surface of the vibrating membrane ranging from IHz to 100
In KHz.

In other words, the vibration frequency generated by the impact of the underwater speaker PZT or hammer-shaped object that is the driving means is 1) 1
z to 100 KHz can be used, but 60 Hz to 5 KHz is more effective.

In addition, the generation of vibration waves to vibrate the surface of the vibrating membrane is
The driving means is continuous or pulsed, and the driving means is not limited to a fixed one, but may be a moving one. In other words, the method of generating this vibration wave may be a continuous constant frequency or any combination of two or more types of frequencies, or a pulsed constant frequency or any combination of two or more types of frequencies. Also good. The reason for generating a combination of frequencies or a pulse is to prevent interference caused by wave reflections.It is possible to generate a continuous constant frequency by adjusting the frequency and distance, but if the distance from the source to the object surface is It is necessary to fix it strictly, and in practice it is preferable to generate it in a pulsed manner.

Furthermore, as a method of preventing interference, a method of reciprocating the source at a constant speed is effective when performing antifouling over a wide range.

(Example) Next, an example of the present invention will be described with reference to the drawings.

In FIG. 1, the surface of a cooling water intake 1 of a power plant, which is illustrated as an object for preventing the attachment of living things, is covered with a vibrating membrane 2 made of a material having rubber elasticity. It is necessary that all surfaces of the vibrating membrane 2 that come into contact with the seawater 3 be coated.

By the way, the vibrating membrane 2 has a surface with rubber elasticity and a rubber hardness of 80 or less (Asker rubber hardness tester type 02) with an elongation rate of 1.
00% or more (Shimadzu Universal Tensile Tester) can be used.

The thickness of the rubber elastic body spanning the vibrating membrane is 0. 3rm■～1
0 dragon can be used, but it is preferable to select the optimum thickness depending on the hardness and elongation rate of the material used.

As a driving means for vibrating the vibrating membrane 2 made of a rubber elastic body,
In FIG. 1, an underwater speaker 4 is shown. As a method of applying vibration from the outside, any method that generates seismic waves underwater can be used in the present invention. Note that there is also a method of applying an impact to the object 1 to be antifouled, for example, with a hammer-shaped object.

Figure 2 shows another embodiment, in which the cooling water intake 1
The front surface of the vibrating membrane 21 is coated with a vibrating membrane 21 made of PZT, and an electric signal can be applied to this vibrating membrane.

FIG. 3 shows still another embodiment, in which a plate-shaped PZT5 is appropriately placed inside the vibrating body as a method of vibrating the vibrating membrane 22 itself, which is a rubber elastic body covering the surface of the cooling water intake port 1. The structure is such that the PZT is embedded at regular intervals and an electrical signal is applied to the PZT.

Next, an experimental example in which the present invention was tested and a comparative example will be explained.

Experimental Examples 1 to 5 Comparative Examples 1 to 2 300 x 100 x 2.3 steel plate with 500 micron anti-corrosion coating (Comparative Example 1), nitrile-butadiene rubber sheet (rubber hardness C2 type, 8
2. A plate with an elongation rate of 110% and a thickness of 3 fins) glued to a steel plate made in the same manner as Comparative Example 1 (Comparative Example 2). A nitrile-butadiene rubber sheet (rubber hardness C2 type 4).
0, elongation rate 300%, thickness 3 mm) was glued to a steel plate prepared in the same manner as in Comparative Example 1 (Experimental Example 1). ) and tolylene diisocyanate (terminal hydroxyl group) 850 parts and propylene oxide Trimethylolpropane-based triol, propylene oxide, and tolylene diisocyanate (terminated isocyanate) 3
50 parts of epoxy resin (epoxy equivalent: 1250) with 100 parts of epoxy resin having a main chain of polyether and 1.3 parts of bis( 5.2 parts of (aminomethyl) cyclohexane was mixed and applied to a steel plate coated with anti-corrosion coating to a thickness of 5 + nn (Experiment Example 3). 10% dimethyl silicone oil (100OC8) was added to room temperature curable silicone rubber TSE322. The mixture was applied to a steel plate with a special anti-corrosion coating to a thickness of 5 mm (
Experimental Example 4) Dimer acid polyester was added to a mixture of 1.3 parts of trimethylolpropane, a catalyst, and 334 parts of water, thoroughly mixed, 38.8 parts of tolylene diisocyanate was added, and the mixture was sufficiently foamed, and then an anticorrosive coating was applied. A steel plate coated to a thickness of 10+*m (Experiment Example 5) was fixed so as to be submerged in the sea, and 1 was used as a source of underwater vibration waves, and 1 was transmitted from a transmitter to an AZP board in front of an underwater speaker 2.100xlOOxO15. .10.50.100.500.100.5000.
100001 (input z pulse tone, distance 5
Vibration waves were continuously applied to the steel plate from a distance of 0 cm, and the surface condition after 12 months was observed.

Experimental Examples 6 to 9 Comparative Example 3 When applying each of the compositions of Experimental Examples 2 to 5, an AZP board measuring 20x20x0.5 was embedded near the center of the board so that an electrical signal could be input, and the experimental example was transmitted from a transmitter. 1-5
The surface condition after the 12 month submersion test was observed by inputting the same signal as above.

As shown in the attached table, by causing the surface of an elastic membrane to vibrate slightly in seawater according to the present invention, the surface vibrates slightly regardless of the type of source of vibration waves, thereby preventing the attachment of marine organisms to the surface of objects. is possible.

There is no transmitter for frequencies below IHz, and 100
Experiments have confirmed that the effect is low at frequencies above KHz because the elastic membrane cannot follow the frequency.

(Effects of the Invention) According to the present invention, the antifouling effect is achieved by utilizing physical surface vibration without containing any pollution-causing compounds, so the antifouling effect is non-polluting and long-lasting. It is effective.

[Brief explanation of drawings]

1 to 3 are cross-sectional views showing embodiments of the present invention, respectively. 1...Object to prevent attachment of living things, 2.21.22
...Vibration membrane, 4.Driving means (underwater speaker), 5.Driving means (PZT board) Above table

Claims (1)

[Claims] 1. A vibrating membrane that covers at least the surface of an object that comes into contact with seawater or the like to prevent attachment of living things, and a driving means for slightly vibrating the vibrating membrane. Structure to prevent biofouling in the sea. 2. A biological adhesion prevention structure, wherein the vibrating membrane according to claim 1 is a rubber elastic member. 3. A biofouling prevention structure, wherein the vibrating membrane according to claim 1 is a member that vibrates itself by applying an electric signal. 4. A biofouling prevention structure, wherein the rubber elastic member according to claim 2 is a structure in which a member that vibrates by applying an electric signal to the rubber elastic membrane is partially embedded. 5. The biofouling prevention structure according to claim 1, wherein the energy source of the driving means for generating microvibrations is an underwater vibration wave generated by applying an electric signal to a vibrating membrane that vibrates when an electric signal is applied. . 6. A biofouling prevention structure characterized in that the energy source of the driving means for applying micro-vibration according to claim 1 is an underwater vibration wave that applies an impact to an object. 7. The structure for preventing adhesion of marine organisms according to claim 1, wherein the driving means vibrates the surface of the vibrating membrane at a frequency of 1 Hz to 100 KHz. 8. The biological adhesion prevention structure according to claim 1, wherein the driving means generates a vibration wave for vibrating the surface of the vibrating membrane continuously or in a pulsed manner. 9. A biofouling prevention structure, wherein the driving means according to claim 1 is movable. 10. A method for preventing biological adhesion in the sea, which comprises slightly vibrating the surface of a member that comes into contact with seawater or the like to prevent biological adhesion.