JPS59170315A - Preventer for adherence of organism to marine structure - Google Patents

Abstract

PURPOSE:To prevent the adherence of marine organisms to the legs of a marine structure by a method in which the sea water is circulated in the space between the legs and a cover and an inhibitor for preventing the adherence of organisms is added to the sea water as needed. CONSTITUTION:When a pump 6 is driven, the sea water in an annular space 18 between legs 1 and a cover 5 is sucked by a pump 6 through an intake pipe 13 and a suction pipe 14, and then jetted into the space 18 through a discharge pipe 16 and a jet water pipe 15. The sea water jetted moves upwards while swirling and is again sucked from the intake pipe 13 and circulated, and on the other hand, chlorine generated in an electrolytic tank is supplied from a fixed pipe 17 into the suction pipe 14 and mixed with the sea water circulating in the space 18 to prevent the adherence of marine organisms to the legs 1.

Description

[Detailed description of the invention] The present invention relates to a device for preventing biofouling on marine structures.

As offshore structures such as offshore plants and offshore work platforms.
Some are known to have multiple legs that penetrate the sea surface up and down. In this type of marine structure, a large amount of marine life such as barnacles scratches and attaches to the outer surface of the legs up to a certain depth from the sea surface, which increases the waterline area of the legs and prevents the effects of waves and currents. This causes various negative effects, such as making marine life easier to catch, so work boats are regularly used to scrape off marine life. However, the removal of marine organisms by such ships is generally difficult and dangerous, and the attachment of marine organisms has become a major problem in the maintenance of marine structures.

The purpose of this invention is 1. An object of the present invention is to provide a hanging device that effectively prevents the adhesion of marine organisms.

The device according to the present invention is removably attached to a marine structure equipped with legs that vertically penetrate the sea surface, with a gap formed on the outer surface of the leg so as to surround a predetermined range from above the sea surface to the p-plane force below. A cylindrical cover attached to the cover, a pump attached to the cover or the offshore structure, piping installed between the cover and the pump to circulate seawater in the space between the legs and the cover, and the offshore structure. 9. A biofouling prevention agent tank is provided, and piping is provided between this tank and the suction side of the pump.9. A biofouling prevention layer is provided on the outer surface of the cover.

As the biofouling prevention agent for the tank, one containing chlorine, one containing copper ions, or other biofouling prevention agent is used. It is well known that chlorine or copper ions inhibit the growth of marine organisms. In the case of chlorine, the tank can be used as an electrolytic cell, and the chlorine generated by electrolyzing a small amount of seawater can be used. In the case of copper ions, a separate copper ion generator is provided.

The biofouling prevention layer on the outer surface of the cover is formed of, for example, a sheet or paint having a biofouling prevention function.

According to this invention, seawater circulates in the space between the legs of the marine structure and the cover, and the biofouling preventive agent is mixed into this seawater as necessary, so that the outer surface of the legs and the inner surface of the cover are Adhesion of marine organisms can be prevented.

Since the biofouling inhibitor is recycled, it is only necessary to compensate for leakage loss during circulation from the tank, which is economical. Furthermore, since the biological adhesion prevention layer is provided on the outer surface of the cover, it is possible to suppress the adhesion of marine organisms to the outer surface of the cover without the need for an anti-adhesion layer. Since the cover is attached to the leg and can be attached and detached, even if marine life becomes attached to the cover, the cover can be easily removed from the leg and pulled onto a marine structure or ship. Removal work can be carried out.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a marine structure and a biofouling prevention device attached to it. Marine structures have multiple legs (1)
The legs (1) are fixed to the seabed (3) and penetrate the sea surface (4) up and down. ) protrudes upward.

The biological adhesion prevention device is removably attached to the outer surface of the leg (1) with a gap formed so as to surround a predetermined range from above the sea surface (4) to below the sea surface (4) of the leg (1). Seawater is circulated through a cylindrical cover (5), a pump (6) attached to the upper end of the outer surface of the cover (5), and an annular space (18) between the legs (1) and the cover (5). Cover for (
5) and the pump (6), and the workbench (2).
) installed on the electrolytic tank (biofouling prevention agent tank) (7
) and piping installed between the electrolytic tank (7) and the suction side of the river pump (6), details of the cover (5) are shown in Figures 2 to 4. ing.

The cover (5) has two semi-cylindrical bodies (8) with a hinge (9)
It is a semi-cylindrical body (
8) The free ends are connected and fixed to form a cylindrical shape with an open top and bottom. A plurality of brackets (10) are fixed to the upper end of the inner surface of the cover (5), and these brackets (10) are fixed to the outer surface of the leg (1) Q.
11) are connected and fixed to each other. In addition, the cover (
A vinyl chloride sheet is attached to the outer surface of 5), thereby forming a biofouling prevention layer (12).

The dimensions and mounting position of the cover (5) are such that even if the height of the sea surface (4) fluctuates, the legs (1) can be placed at a certain depth from the sea surface (4) where marine life may attach. It surrounds the outer surface and is determined such that the pump (6) is always located above sea level (4).

The piping between the cover (5) and the pump (6) is connected to the cover (5).
), a plurality of water intake pipes (13°) and a cover (5>
The end of each water intake pipe (13) located outside the pump (6)
), a suction pipe (14) is removably attached to the suction side of the cover (5) and connects them, a plurality of fountain pipes (15) are fixed to the lower end of the cover (5) so as to penetrate therethrough, and the cover ( The discharge pipe (16) is detachably attached to the end of each fountain pipe (15) located on the outside of the pump (5) and the discharge side of the pump (6) to connect them. The tip of the fountain pipe (15) located inside the cover (5) is
It faces counterclockwise in the tangential direction of the leg (1) when viewed from above so that the seawater spouted from here moves upward while swirling in the annular space (18) (see Figure 4). Also,
The tip of the water intake pipe (13) located inside the cover (5) is opposite to the spout pipe (15) when viewed from above so that it can easily suck in the seawater that has moved upward while swirling. and facing clockwise in the tangential direction of leg (1) (third
(see figure number 1).

The electrolytic cell (7) generates chlorine by electrolyzing a small amount of seawater taken in from the sea. And electrolytic tank (7)
The piping between the pump (6) and the workbench (2) and the legs (
1), one end of this pipe (17) is fixedly connected to the electrolytic cell (7), and the other end is connected to the suction pipe (14). It is detachably connected to the upper part of the. Although not shown, a valve is provided at an appropriate position on the fixed pipe (17).

Of the above biofouling prevention device, the electrolytic cell (7) and the fixed tube (17) are always fixed to the marine structure, and the other parts are fixed to the legs (1°) and fixed as follows, for example. It is attached to the pipe (17).

That is, first, prior to the installation work, the suction pipe (14) and the discharge pipe (16) are removed from the cover (5), the automatic ends of the semi-cylindrical body (8) are separated, and the cover (5) is opened. put. In addition, at this time, the pump (6) and the water intake pipe (1
3) and the fountain pipe (15) remain fixed to the cover (5).

Then, this cover (5) is placed around the leg (1), and the automatic ends of the semi-cylindrical body (8) are connected to each other to connect the cover (5).
) close. Next, the discharge pipe (1B) is attached to the discharge side of the fountain pipe (15) and the pump (6), and the suction pipe (14) is attached to the water pipe (13) # and the suction side of the pump (6). Finally, the bracket (10) of the cover (5) is fixed to the bracket (11) of the leg (1), and the suction pipe (14) is attached to the fixed pipe (17). When removing the cover (5) from the leg (1), the operation may be performed in the opposite manner. In this way, the connecting and disconnecting operations of each part can all be performed above the sea level, but the installation and removal procedures are not limited to those described above.

Once the cover (5), suction tube (14) and discharge tube (18) are in place, pump (6) is driven continuously to operate the anti-biofouling device. As a result, the seawater in the annular space (18) flows into the intake pipe (13).
The seawater is sucked into the pump (6) through the suction pipe (14), and this seawater is further pumped through the discharge pipe (16) and the fountain pipe (14).
5) into the annular space (18). Then, the seawater spouted into the annular space (18) moves upward while swirling, and is sucked in again from the water intake pipe (13-) and circulates infrequently. On the other hand, chlorine generated in the electrolytic cell (7) is supplied from the fixed pipe (17) to the suction pipe (14) and mixed into the seawater circulating in the annular space (18). Therefore, chlorine-containing seawater circulates in the annular space (18), and as this seawater comes into even contact with the outer surface of the leg (1) and the inner surface of the cover (5), the seawater against them Adhesion of living organisms is reliably prevented. Chlorine in the seawater circulating in the annular space (18) leaks little by little into this gate, but the concentration of chlorine in the seawater is reduced by the chlorine supplied from the electrolytic tank (7) to prevent the growth of marine organisms. The concentration is maintained at the level required to do so. In the case of chlorine, the concentration required to prevent the growth of marine organisms on it is extremely dilute, so there is no risk of corrosion of marine structures and biofouling prevention devices. Since chlorine is also recycled, it is only necessary to replenish the leakage loss from the electrolytic cell (7), which is economical. Also, be sure to replenish chlorine continuously in small amounts. Alternatively, it may be performed intermittently at predetermined intervals. Furthermore, since the outer surface of the cover (5) is provided with a biological adhesion prevention layer (12), there is little risk of marine organisms adhering to this surface. However, if marine organisms are attached to the cover (5),
5) is removed from the leg (1) and lifted onto a marine structure or ship, and after removing marine life, it is reattached to the leg (1).
It should be installed on. In this way, the marine structure can be removed with the cover (5) pulled up onto the marine structure or ship, making the work extremely easy. Furthermore, since the biological adhesion prevention II (12) suppresses the adhesion of marine organisms, even if removal work is necessary, the frequency of removal work becomes extremely low. In addition, replacement cover (5)
Separately prepare a cover (5) with marine life attached to it.
At the same time, remove this replacement cover (
5) may be attached to the leg (1).

In the above embodiment, the marine structure is equipped with legs fixed to the seabed, but it can also be constructed with legs that are not fixed to the seabed, such as a floating body below the sea surface and a work platform above the sea surface. It may also be a semi-submersible floating structure connected by legs.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of the invention, and FIG. 2 is a front view showing an embodiment of the invention.
FIGS. 3 and 4 are perspective views showing an enlarged cover portion of the biofouling prevention device shown in FIG. (1) Legs, (4) Sea surface, (5) Cover, (6) Pump, (7) Electrolytic tank (biofouling prevention agent tank), ( 12)...Biofouling prevention layer,
(13)... Water intake pipe, (14)... Suction pipe, (15
)...Fountain pipe, (16)...Discharge pipe, (18)...
- Annular space. Applicants for the above patents: Hitachi Zosen, Ltd., and 4 others Figure 2 Figure 1

Claims (1)

[Claims] In an ocean-going animal equipped with legs (1) that penetrate the sea surface (4) up and down, the legs (1) penetrate the sea surface (4) from above the sea surface (4).
A cylindrical cover (5) detachably attached to the outer surface of the leg (1) with a gap surrounding a predetermined area extending downward, and a pump (6) attached to the cover (5) or the marine structure. ) and the space (18) between the leg (1) and the cover (5)
Cover (5) and pump (6) to circulate seawater
The piping installed between them, the biofouling prevention agent tank (7) installed on the marine structure, and the tank (7) and pump (
6) piping provided between the suction side of the structure, and a biofouling prevention layer (12) is provided on the outer surface of the cover (5).