JPS6319384Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a biofouling prevention device for marine structures.

2. Description of the Related Art Offshore structures such as offshore plants and offshore work platforms that are equipped with a plurality of legs that vertically penetrate the sea surface are known. 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. Because of various harmful effects such as increased susceptibility to marine life, 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 to provide a device that can effectively prevent the adhesion of marine organisms.

This idea is based on a marine structure equipped with legs that penetrate the sea surface up and down, with a plurality of layers attached to the outer surface of the legs in a watertight manner to surround a predetermined range from above the sea surface to below the sea surface. It is equipped with a cylindrical sheet and a tearing cord which is inserted between each sheet so as to pass vertically through the sheet and whose lower end is fixed.

According to this invention, a plurality of cylindrical sheets are attached to the outer surface of the leg in a layered manner so as to surround a predetermined area in a watertight manner, so that seawater comes into contact with the outer surface of the outermost layer of the sheets. However, since it does not come into contact with the outer surface of the leg, living things are forced to adhere to the outer surface of the outermost sheet, but it is possible to prevent living things from adhering to the outer surface of the leg. A tear rope with a fixed lower end is inserted between each sheet so as to pass through it vertically.
Among the tear ropes, for example, when the upper end of the tear rope corresponding to the outermost sheet is pulled, the outermost sheet is torn in the longitudinal direction, so that this sheet can be easily separated from the leg. In this way, the deposits attached to the outer surface of the outermost sheet can be easily removed together with the sheet, so if the above-mentioned sheet separation operation is performed periodically at regular intervals, the attachment of organisms can be prevented. This can be kept within a range that does not cause any adverse effects on the maintenance of offshore structures.

Embodiments of this invention will be described below with reference to the drawings.

FIG. 1 shows a marine structure and a biofouling prevention device attached to it. The offshore structure is composed of a plurality of legs 1 and a work platform 2 supported horizontally on the upper ends of these legs.The legs 1 are made of steel cylindrical pipes and are fixed to the seabed 3, and also extend above and below the sea surface 4. It penetrates and protrudes above sea level 4.

The biological adhesion prevention device includes a plurality of cylindrical sheets 5 attached to the outer surface of the leg 1 in layers, and a tearing cord 6 for sheet removal.

The sheet 5 is cylindrical with an open top and bottom,
Made of rubber sheet. Further, the material of the sheet 5 may be a vinyl chloride sheet having a function of preventing biological adhesion. The length and mounting position of the sheet 5 are determined so that even if the height of the sea surface 4 fluctuates, the range where marine organisms may adhere, that is, the range from above the sea surface 3 to almost the bottom of the sea floor 3 below the sea surface 3, is determined. It is decided to surround it. Further, the diameter of the sheet 5 is determined so as to make close contact with the outer surface of the leg 1 by utilizing the elasticity of the rubber. And each sheet 5 is
Each sheet 5 is attached with adhesive to ensure watertightness.

As shown in FIG. 2, the tear rope 6 is a steel wire that is inserted around the leg 1 at regular intervals so as to vertically penetrate between the sheets 5, and its lower end is near the lower end of each sheet 5. It is connected and fixed by a bracket 7, and its upper end extends to the height of the workbench 2.
Furthermore, a notch 8 is provided at the upper end of each sheet 5 at a portion through which a tearing cord 6 passes, in order to make the sheet 5 easier to tear.

Since the outer surface of the leg 1 is kept watertight, no living organisms can attach thereto. On the other hand, living things adhere to the outer surface of the outermost sheet 5. When the amount of biofouling reaches an undesirable level, it is necessary to remove it together with the sheet 5 by separating it from the legs 1.

Assume that the outermost sheet 5 is now separated.
When the upper end of the tearing cord 6 inserted between the outermost sheet 5 and the sheet 5 one layer inside is pulled on the workbench 2, the outermost layer sheet 5 is cut into a notch 8 at its upper edge.
It is torn downward from the part of the body. Then, this sheet 5 may be peeled off and separated from the leg 1. When peeling off this sheet 5, care must be taken so that the adhesion of other sheets 5 does not come off. In order to perform this peeling operation easily and quickly, the adhesive strength of each sheet 5 is adjusted from the outermost sheet 5 to the innermost sheet 5.
You may weaken them in this order.

If it is necessary to separate the sheets 5, for example every two years, the number of sheets 5 may be about five. This is because the service life of this type of offshore structure is usually 10 years.

By periodically separating the sheets 5 in this manner, the marine structure can be maintained in substantially the same condition as when it was newly built over its lifetime with regard to the attachment of living organisms.

In the above embodiment, the offshore structure is equipped with legs fixed to the seabed, but it is also possible to construct a structure with legs that are not fixed to the seabed, such as a floating structure below the sea surface and a work platform above the sea surface. It may be a semi-submersible floating type connected by legs, or it may be a towed type.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a front view, and Fig. 2 is an enlarged perspective view of the sheet portion of the biofouling prevention device shown in Fig. 1. 1...leg, 4...sea surface, 5...sheet, 6...
Tearing cord.

Claims (1)

[Claims for Utility Model Registration] In a marine structure equipped with legs 1 that vertically penetrate the sea surface 4, a layer is provided on the outer surface of the legs 1 so as to surround a predetermined range from above the sea surface 4 to below the sea surface 4. A plurality of cylindrical sheets 5 attached in a watertight manner, and each sheet 5
A biological adhesion prevention device comprising tearing ropes 6 inserted between the tearing ropes so as to pass vertically through the tearing ropes and having lower ends fixed.