JP2524211B2 - Seawater AC device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a device for exchanging seawater in the harbor, a fishing port, and the like with the open sea.

[Conventional technology]

Among such seawater AC devices, there are those that use tidal currents and waves as those that do not use power such as electric power.
A structure is installed at the boundary between the open sea and the harbor to change the direction of seawater flow, promote wave breaking, and increase the amount of open seawater introduced.

[Problems to be Solved by the Invention]

In this way, the method of installing structures at the boundary between the open sea and the harbor is subject to topographical restrictions, and especially in closed bays, the exchange of seawater is limited to only the mouth of the bay, making it difficult to achieve sufficient seawater exchange. As a result, oxygen-free water mass is generated in the bottom layer of the bay in the summer, and when it rises due to the wind, it causes blue tide and may damage the ecosystem in the bay.

The object of the present invention is to solve the inconvenience of the above-mentioned conventional example, and to freely perform seawater exchange in an arbitrary wide range not limited to the mouth of a bay, and also a simple structure using a breakwater which is an external facility of a port. To provide a device.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention has a caisson having two communicating air chambers in the upper part, one air chamber is located on the open sea side, and the other air chamber is located inside the port. Let's set it on the sea floor,
An opening for seawater intake is formed below the air chamber on the outside sea side, and the ends of the water pipes that communicate with the open sea and the inside of the port are opened below the air chamber inside the port, and check pipes are connected to these pipe ends. The gist is that a valve is provided.

[Action]

According to the present invention, when seawater flows into the caisson from the opening when the wave rises, the pressure in the air chamber changes, whereby the seawater inside the caisson inside the port is pushed to the outside sea, and when the wave descends, the seawater inside the port Is taken into the caisson inside the port. Even when the water level inside the harbor is higher than that on the open sea side due to the difference in tide level, the seawater inside the harbor is taken into the caisson inside the harbor and the seawater inside the caisson inside the harbor is discharged to the open sea.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a vertical front view showing an embodiment of the seawater AC device of the present invention, in which 1 denotes a caisson, the inside of which is divided by a partition wall 2 into a chamber 3 and a chamber 4, Air chambers 3a, 4a communicating with each other were formed in the upper portions of 3,4.

One chamber 3 is located on the open sea side, and the other chamber 4 is located inside the harbor, and the room 3 is provided with an opening 5 for the entry and exit of seawater from the open sea, and the chamber 4 is for intake with one end open to the harbor. Check valve 7a that opens the other end of the water pipe 6 and opens only to the chamber 4 side at this pipe end
In addition to the above, the other end of the water supply water pipe 8 having one end open to the open sea is opened, and a check valve 7b that opens only on the open sea side is provided at this pipe end.

As the structure of the check valves 7a and 7b, as shown in FIG. 2, a large number of valves are provided in the cross section of the pipe that are lightweight and have a small lift amount so that they can operate even if the flow velocity in the pipe is low. It is preferable to use a multi-valve type that is also provided, and the ball valve 10 that is covered with rubber or the like so as to function even when dust or the like in the seabed layer is caught.

Reference numeral 9 in the figure indicates a filling sand for weight increase for wave and earthquake resistance.

 Next, the operation will be described.

When the waves rise and the waves of the open sea rush to the caisson 1, seawater flows into the chamber 3 through the opening 5 and the water level in the chamber 3 rises. As a result, the volume in the air chamber 3a decreases, the pressure applied there is transmitted to the air chamber 4a, the internal pressure in the air chamber 4a increases, and the water surface of the chamber 4 is pressurized.

As a result, the water pipe 8 for water supply that is open in the chamber 4
The check valve 7b is pushed open and the seawater in the chamber 4 is discharged to the open sea through the water pipe 8 for reverse water.

Next, when the wave descends, the water level in the chamber 3 drops and the internal pressure in the air chamber 4a drops, so the check valve 7a of the water intake pipe 6 opens and seawater inside the port enters the chamber 4. Incorporated.

In this way, as the waves rise and fall, the seawater inside the port is taken into the caisson 1 by the wave energy, and this seawater is then drained to the open sea side.

Further, when the water level inside the port is higher than that on the open sea side due to the tide level, the valve 7a is pushed open due to the tide level difference, and seawater inside the port flows into the chamber 4 through the water intake pipe 6 for intake. Then, when the water level in the chamber 4 rises, the valve 7b is pushed open by the water pressure, and the seawater in the port in the chamber 4 is discharged to the open sea through the water pipe 8 for water supply.

In this way, seawater in the bay is taken into the caisson 1 due to the tide difference and then drained to the open sea.

 Here, the amount of seawater exchange is estimated by calculation.

If the wave height is 1 m, the water level in the air chamber (3a) is ± 0.5 m, and the pressure in the upper and lower air chambers is 0.05 atmospheric pressure rise and fall (volume 19/20 to 21/20) Water pipes (6) (8) φ300 m / m l = 200 m Δh = 0.5m (head difference), f ′ = 20 (inlet, bend, valve loss) f = 0.027 f = 17.8 V = 0.113m / s Q = 8.0 × 10 ⁻³ m ³ / s (690m ³ / (day) is the flow rate per pipe.

Next, the use example of the present invention will be explained with reference to FIG. 3. The water intake side pipe end of the water intake pipe 6 is made to face the bottom layer of the seabed in the bay, and the drainage side pipe end of the water supply water pipe 8 is provided. Face near the surface of the open sea.

Due to this, in the eutrophied bay, the surface water becomes hot and low density in summer, so it is difficult to mix seawater up and down, and oxygen-free water mass is generated in the bottom layer of the seabed, especially in the depression, causing blue water. Although it causes the tide, the oxygen-free water mass in the depression of the seabed can be discharged to the open sea, preventing the occurrence of the blue tide disaster. Also, by discharging the discharged water near the surface of the open sea,
There is little risk of aeration and adverse effects on the open sea ecosystem.

As another example of use, as shown in FIG. 4, by reversing the valve opening directions of the check valves 7a and 7b shown in FIG. 1, the seawater of the open sea can be taken into the bay. It is also possible to introduce deep-sea nutrient-rich seawater into the bay and utilize it for the cultivation of marine resources.

〔The invention's effect〕

As described above, the seawater exchange device of the present invention can move seawater between any two points in the open sea and the bay by utilizing the difference in water level between the open sea and the bay caused by the difference in waves and tidal level, and the installation place is restricted. It has a wide range of uses, such as the prevention of blue tide.

Moreover, the structure is simple and can be used as a wave-dissipating structure.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing one embodiment of a seawater AC device of the present invention, FIG. 2 is a plan view of a check valve, FIG. 3 is an explanatory view showing a usage example, and FIG. 4 is another usage example. FIG. 1 ... Caisson, 2 ... Partition wall 3,4 ... Chamber, 3a, 4a ... Air chamber 5 ... Opening, 6,8 ... Water pipe 7a, 7b ... Check valve, 9 ... Filling sand 10 ... Ball valve

Claims (1)

(57) [Claims] 1. A caisson having two communicating air chambers at the top is installed on the seabed with one air chamber on the open sea side and the other air chamber inside the harbor, and below the open air chamber on the open sea side. A feature is that an opening for seawater intake is formed, the end of the water pipe that communicates with the open sea and the inside of the port is opened below the air chamber inside the port, and a check valve is provided at the pipe end of these water pipes. Seawater AC device.