JPS61268590A - Floating structure - Google Patents

Abstract

PURPOSE:To make a semi-submerged floating structure stable and to reduce the mooring force by providing the submerged body of the floating structure with fins so as to generate advancing force by tidal current force during mooring. CONSTITUTION:A semi-submerged floating structure 1 composed of a plurality of submerged bodies 2, columns 3 and a working platform 4 is provided at the upper or lower portion of the submerged bodies 2, 2a with fins 5, 5a. The fins 5, 5a are of the same dimension and disposed symmetrically with respect to the center line C of the floating structure 1. During mooring of the floating structure 1, the tidal current force W acts on the fins 5, 5a to generate lift L, which generates as components advancing force M and pushing/pulling force N. The pushing force N acting in the opposite directions toward both sides of the floating structure 1 makes the moored floating structure 1 stable. Furthermore, the advancing force M reduces the mooring force.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a floating structure that is moored at a predetermined position and is used for purposes such as offshore work platforms and the recovery of ocean energy such as uranium contained in seawater. Concerning the improvement of things.

[Prior art]

For example, a semi-sub-type offshore work platform or platform used when drilling for oil in the ocean has a column mounted on two parallel floating bodies (pontoons), and the upper end of the column is A superstructure is provided, and oil drilling equipment is provided within the superstructure.

For operations such as oil drilling, it is necessary to maintain the offshore workbench in a specified position.However, there are naturally strong winds and currents in the ocean, and this makes it easy for the offshore workbench to move, making it difficult to keep the offshore workbench in the specified position. Propulsion means such as thrusters are used to maintain this.

In addition, for another purpose of recovering uranium, etc. contained in seawater, it is necessary to suspend a container containing a uranium adsorbent between the floating bodies and flow seawater through the adsorbent. In this uranium recovery work as well, it is necessary to hold the floating structure in a predetermined position, and as mentioned above, propulsion means such as thrusters are used.

By the way, this means of propulsion needs to be operated at all times due to tidal currents, etc., but this requires a fairly large amount of power, and a place to mount the power generator and the means of propulsion driven by it is required. Is required.

When mooring a semi-sub-type offshore work platform, a single point mooring method is mainly used, but when wind and tidal forces act on the offshore work platform, the mooring force becomes considerably large.
The drawback was that it required a large mooring device to withstand it.

[Purpose of the invention]

The present invention relates to the above-mentioned offshore work platform or floating structure,
The purpose is to provide a floating structure that can be moored in a fixed position for a long period of time without power or with small power, such as when recovering uranium contained in seawater. It is.

Yet another object is to provide a floating structure with low mooring force and improved directional stability.

Yet another object is to provide a floating structure capable of generating forward force on the floating structure by recovering tidal current power.

[Summary of the invention]

In order to achieve the above object, the present invention is configured such that one or more pairs of fins are provided at the upper and/or lower part of a plurality of submerged bodies, and the fins generate forward force on the submerged bodies. It is a floating structure characterized by:

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a side view of the floating structure, and FIG. 2 is a bottom view thereof.

The floating structure 1 includes a plurality of submerged bodies 2, a plurality of columns 3 planted on top of the submerged bodies 2, a work table 4 fixed to the upper end of the columns 3, and an upper part of the submerged bodies 2. It is composed of one or more pairs of fins 5 planted at the bottom of the fin.

The fins 5 are important members in the floating structure according to the present invention, and are formed symmetrically on the left and right submerged bodies 2. The provided fins 5a are symmetrically formed with the same dimensions with respect to the center line C of the floating structure 1.

This floating structure 1 is moored in the ocean and is subjected to the action of tidal current force W. When this tidal current force W acts on the left and right pair of fins 5.5a, a lifting force is generated, and accordingly, the lifting force is The forward force M is the component force of R, and the submerged bodies 2, 2a
A push/pull force N is generated to push and pull, respectively.

The two pushing and pulling forces N on the two submerged bodies 2, 2a are in opposite directions and have the same magnitude, so they cancel each other out, and the two forward forces M are applied to each submerged body 2.2a. It will work.

The two forward forces M are in opposite directions to the tidal force W, and act as forces that move the floating structure 1 forward. These forward forces have the same value with respect to the center line C of the floating structure 1,
Since they are facing in the same direction, the generation of a moment that would destabilize the direction of the floating structure 1 is prevented.

Usually, the submerged bodies 2, 2a are entirely submerged in water to reduce or avoid the shaking of the floating structure 1, but in this sense, one or more pairs of fins 5'' are placed against the upper surface of the submerged bodies 2, 2a. As described above, the forward force M can be generated by these.

The size, shape, number and position of the fins 5.5a and 5' are determined by taking into consideration the floating structure l and the tidal currents in the sea area in which it is moored.

FIG. 3 shows an example of how to use the floating structure 1 according to the present invention, and shows a state in which the floating structure 1 is moored to a one-point mooring device 7 via a mooring rope 6 at the front part. ing. A recovery means 8 such as an adsorbent for recovering substances dissolved in seawater such as uranium is supported between the submerged bodies 2 and 2a.

This recovery means 8 is installed between the submerged bodies 2 and 2a, and is maintained in a predetermined state for a long period of time.

The tidal force W acts on the floating structure 1 due to the fins 5.5a provided on the lower or upper part of the submerged bodies 2, 2a, and further on the upper and lower parts.

A forward force M is generated by 5゛.

〔Effect of the invention〕

As described above, the floating structure according to the present invention includes: one or more pairs of fins are provided on the upper and/or lower parts of a plurality of submerged bodies, and the fins generate forward force on the submerged bodies. Since it is configured as follows, the following effects can be achieved.

(11) When the tidal force W acts on the fins 5.5a and 5' provided on the left and right submerged bodies 2 and 2a, the fins 5.
．． A forward force M is generated at 5a, 5°, and a moment is generated along with this forward force M, but this moment is canceled out by the left and right submerged bodies 2, 2a, so the direction of the floating structure l is stabilized. be able to.

(2) Although the tidal force W tries to sweep away the floating structure 1, the forward force M partially opposes this, so the mooring force can be reduced.

Therefore, unlike conventional floating structures, a propulsion device such as a thruster is not necessary, and even if a propulsion device is provided, a small power one is sufficient.

(3) Due to various advantages such as floating structures, the floating structure and its mooring device according to the present invention can be manufactured at a low cost, and it is stable in the ocean for a long period of time and under favorable conditions. , can be moored without power.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Figure 1 is a side view of a floating structure, Figure 2 is a bottom view of the same, and Figure 3 is an apparatus for recovering uranium etc. dissolved in seawater. 1 is a perspective view showing a situation in which the device according to the present invention is used. 1... Floating structure, 2, 2a... Submerged body, 3...
Column body, 4... Upper structure, 5.5a, 5°... Fin, 6... Mooring cable, 7... One-point mooring device, 8... Recovery means.

Claims (1)

[Claims] 1. A floating structure characterized in that one or more pairs of fins are provided at the upper and/or lower portions of a plurality of submerged bodies, and the fins are configured to generate forward force on the submerged bodies.