JPS6043488B2 - Structures that prevent marine organisms from adhering to them - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to structures that have the effect of preventing the adhesion of adherent marine organisms such as barnacles and mussels, such as various types of equipment that use seawater, piping or intake pipes that allow seawater to pass through, or marine structures. This prevents adherent marine organisms from adhering to various structures immersed in seawater without contaminating the seawater.

If adherent organisms such as barnacles adhere to various structures immersed in seawater, they may cause problems such as corrosion of equipment and reduced flow rates.

Therefore, it is necessary to periodically peel off and remove such deposits, and if this work is to be done manually,
Regardless of the case where the adhesion area is small, in the case of structures of huge facilities such as power plants, there is a problem in that not only a great deal of labor is required, but also it is difficult to dispose of a large amount of biological remains. On the other hand, the method of killing sessile organisms by adding chemicals such as chlorine does not have the above problems, but this method mixes a large amount of chemicals into the seawater and causes marine pollution, so it is not the preferred method. I can't say that.

Another method is to apply antifouling paint, as is conventionally done on the bottom of ships, but this method is not the preferred method, as there is a risk that the heavy metals in the paint may leach into the seawater. do not have.

Therefore, the inventors decided to experiment with the relationship between the surface roughness of underwater structures and the adhesion of organisms, and mixed sand with a particle size of about 1-100 mm into the adhesive and glued it to the inner surface of a model tube (100-100 mm in diameter). By applying the coating, a coating layer is formed, and the above model pipe is attached via a branch valve of the cooling water intake pipe of the actually operating equipment (power plant), and seawater is passed through this to check the state of attached organisms. observed. Conventionally, by roughening the adhesion wall surface,
It is believed that the adhesion of living things is encouraged, and the above-mentioned sand coating layer makes the adhesion wall surface as rough as necessary, so the inventors believe that the above experiment confirms the conventional idea. I expected it.

However, according to the experimental results, although the roughness of the attached wall surface has become rougher due to the sand coating,
It turned out that it was actually difficult to adhere.

After considering the experimental results, we found that the formation of a sand coating layer makes it difficult for organisms to adhere to it.
It was found that this was not related to the roughness of the wall surface, but was due to the coating material of the coating layer, ie, sand. This invention has been made based on the above-mentioned viewpoint, and is based on the above-mentioned viewpoint.
The structure of the invention is that a sand coating layer is formed by adhering sand in a planar manner using an adhesive.

The above-mentioned sand is adhered to the surface of the underwater structure 1 in a layered manner to form a sand coating layer 3, as shown in FIGS. 1A and 2B.

To attach sand to a surface, you can apply sand mixed with adhesive, or the usual method for attaching sand to a surface is to first apply adhesive and then sprinkle sand. By means such as The sand 2 forming the coating layer 3 is
The sand 2 is bonded to each other, and the sand 2 and the structure 1 are bonded to each other. However, because the sand 2 particles themselves are uneven and there are gaps between the particles, some of them may not have sufficient adhesive strength, and may peel off due to seawater flow 6 etc. (Figure 1) reference). The reason why marine life does not adhere to the structure as described above is as follows. Figure 1A shows particles of approximately 1mm diameter on the surface of underwater structure 1. A coating layer 3 of the sand 2 is formed by adhering the sand 2 with an adhesive.
Approximately 0.2Tn in size on the surface of coating layer 3! 4 larvae of n, and about 1 Tm which has grown slightly! This shows a situation where IL young shellfish 5 is attached.

[First reason]

As mentioned above, the larva 4 is relatively small compared to the grain size of sand 2.
Or, considering the size of the young shellfish 5, each grain of sand 2 is
At most, it is attached to two grains of sand 2.

Meanwhile, the coating layer 3 is shaped. Since the sand 2 that forms is placed in the flow of seawater, as shown in the same figure, it may fall off due to lack of adhesion or decrease in adhesion (see symbol a), or may fall off due to dissolution of the sand surface (see symbol b). ), sand 2 is coated with coating layer J due to shedding due to abrasion of the sand surface (see code c), etc.
Since the sand 3 may peel off and fall off, it is thought that the larvae and young shellfish 5 fall off together with the sand 2. [Second reason] Also, as shown in Figure 2, barnacle 7 has a weight of about 5w.
It grows to about 1.5 m and attaches to several pieces of sand 2.

However, since the surface of the coating layer 3 has many uneven surfaces formed by the sand 2, the adhesion force is not as strong as that shown on the left, and it is considered that the coating layer 3 is likely to fall off due to the pressure of the seawater flow. [Third reason] Furthermore, no ecology in which barnacles adhere to sand surfaces has been observed, and it is thought that barnacles have a habit of not adhering to sand surfaces.

It is thought that the above three reasons act singly or in combination to make it difficult for adherent organisms such as barnacles to adhere to the coating layer 3.

Therefore, the present invention is applicable to structures immersed in seawater, such as various types of equipment using seawater, piping or intake pipes through which seawater passes, or marine structures that have barnacles and other structures on surfaces that come into contact with seawater. It has the effect of preventing the adhesion of sessile organisms such as , mussels, cracked mussels, and snails.

In addition, the sand coating layer used as a means to prevent such adhesion has no risk of contaminating seawater, so it has no effect on marine life, and in this respect it is much more effective than methods such as spraying chemicals or applying anti-pollution agents. It is an excellent product and has the effect that the material cost is extremely low.

[Brief explanation of drawings]

Fig. 1) The diagram and the outer figure, the figure 2, and the diagram of the diagram and the diagram are all indicated in the state of adhesion or dropping out of the sea. 1...Structure, 2...Sand, 3...
...Coating layer.

Claims (1)

[Scope of Claims] 1. A structure that has the effect of preventing the adhesion of sea creatures, in which a sand coating layer is formed by adhering sand in a planar manner with an adhesive on the surface of the underwater structure that comes into contact with seawater. 2. A structure having an effect of preventing adhesion of marine organisms according to claim 1, wherein the sand has an average particle size of about 0.3 to 1.5 mm.