JPS587555B2 - Oil spill prevention mechanism of oil embankment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oil spill prevention mechanism for an oil dike.

Oil dikes are installed around oil storage equipment such as tanks to prevent oil leakage due to destruction of tanks or oil pipes from flowing out of the oil storage area.

This oil embankment is equipped with a drainage outlet to drain rainwater from inside the embankment, and during normal times, the drain gate is always open to drain rainwater. In the event of an oil leak, the gate must be closed immediately.

However, it is extremely difficult to reliably close the drain gate in the event of an emergency such as an earthquake, and there have been many cases of oil leaking from the drain in the past.

In other words, this oil spill prevention method has many problems with the reliable operation of the gates, such as the number of gates to be operated, securing the operating power supply, corrosion of the gates, adhesion of shellfish, etc., and malfunctions due to earthquake motion. there were.

This invention was devised in view of the above-mentioned conventional problems.
This system uses the difference in specific gravity between water (or seawater) and oil to prevent leaked oil from flowing out of the drain, and does not require any mechanical operation in normal times or in the event of an accident. It is an object of the present invention to provide an oil spill prevention mechanism for an oil dike that can reliably prevent oil leakage without causing any hindrance to oil discharge.

The oil spill prevention mechanism of this invention utilizes the difference in specific gravity between water (or seawater) and oil, and its principle is as follows:
As shown in FIG. 1, when water W is put into one side of the U-shaped tube 1 and oil (specific gravity less than 1) 0 is put into the other side, a difference ΔH occurs between the oil level and the water level.

At this time, if the heights of the oil and water surfaces from the oil-water interface S are respectively HO tHW and the specific gravity of oil is α, then Hw - α
HO (1), and ΔH=HO−Hw=(1−α) HO′ (2).

That is, as shown in FIG. 2, in the straight pipe 2 containing oil O, the distances of the upper end 2a and lower end 2b of the straight pipe 2 from the water surface are ΔH in equation (2) and Hw in equation (1), respectively. If it is made larger than , the oil O in the straight pipe 2 will not flow out of the pipe.

It goes without saying that when the water is seawater, α in equations (1) and (2) is the specific gravity α' of oil relative to seawater.

Next, this invention will be explained with reference to an embodiment applying the above-mentioned principle. Reference numeral 3 is an oil dike provided around an oil storage facility 4 such as a tank, and 5 is an oil dike that drains rainwater, etc. inside the oil dike 3 into an oil storage area. This is a drain pipe that drains water to the outside.

This drain pipe 5 has a sufficient length and is disposed deep in the sea W1 or underwater W2, and its outlet end 5a is located at the oil-water interface S when the oil leakage from the oil storage facility 4 is at its maximum. It is positioned further down.

That is, as shown in Figures 3 to 6, Ho, Hw, and △H in the state where oil leakage is maximum are expressed as (1)
, (2), and the outlet end 5a
If it is located below the oil-water interface S, the leaked oil will not flow out from the drain pipe 5 into the sea W1 or the water W2 even when the oil leak is at its maximum.

Further, in normal times, the water surface in the drain pipe 5 is at the same level as the sea surface or the water surface, and rainwater caused by rainfall can be discharged without any problem.

In the first embodiment shown in FIG.
In the second embodiment shown in FIG.
Instead of installing the drain pipe 5 directly into the sea, a pit 6 is provided between the sea and the oil embankment 3, and the drain pipe 5 is provided inside the pit 6, and the seawater is guided through the guide hole 7 to drain the oil. This prevents water from flowing out, and has the advantage of simplifying piping work.

Next, FIGS. 5 and 6 show a third embodiment and a fourth embodiment of the present invention, both of which use freshwater such as drainage from the oil embankment and rainwater without using seawater. It is something.

In FIG. 5, a pit 6 is provided adjacent to the oil barrier 3, and a drain pipe 5 is disposed in the water W2 stored in the pit 6.

Further, a discharge hole 8 is provided in the upper part of the shaft 6.
It maintains a constant water level inside and drains rainwater during normal times.

The fourth embodiment shown in FIG.
A continuous overflow pipe 9 is provided.

The third and fourth embodiments are effective in cases where the height difference between the oil barrier 3 and the sea level is large and the sea level cannot be used, and all that is needed is to provide a pit etc. to store rainwater. Therefore, it can be applied to places that are not adjacent to the sea.

Note that a plurality of drain pipes 5 may be provided.

That is, it can be shared by multiple oil barriers.

Furthermore, although the case of an oil storage facility equipped with an oil dike has been described above, the spill prevention mechanism of the present invention can be effectively applied not only to this but also to other oil storage facilities that require oil spill prevention.

As mentioned above, according to this invention, oil leakage can be reliably prevented in the event of an emergency such as an earthquake without requiring conventional operations such as closing gates. etc. can be discharged without any hindrance.

Furthermore, since drainage pipes are used to prevent outflow, the equipment is relatively simple and can be installed relatively easily, whether new or existing.

[Brief explanation of drawings]

Figures 1 and 2 are explanatory diagrams showing the principle of the oil spill prevention mechanism according to the present invention, Figure 3 is a schematic sectional view showing the first embodiment of the invention, and Figure 4 is a diagram showing the introduction of seawater into the shaft. A schematic cross-sectional view showing a second embodiment of the system, and FIGS. 5 and 6 are a third embodiment and a fourth embodiment that utilize drainage. 1... U-shaped pipe, 2... Pipe, 2a... Upper end, 2b... Lower end, 3... Oil dike, 4... Oil storage equipment, 5... Drain pipe, 5a
... Outlet end, 6 ... Vertical hole, 7 ... Guide hole, 8 ... Discharge hole,
9...Overflow tube, 0...Oil, W1, W2...Seawater, water, S...Oil-water interface.

Claims (1)

[Claims] 1. Drainage pipes for draining water inside the oil barrier to outside the oil storage area in the oil dike installed around the mountain pass oil equipment to prevent oil leaking from the oil storage equipment from flowing out of the oil storage area in the event of an accident. The drain pipe is arranged so that its outlet end is located sufficiently deep in the sea or underwater, and the drain pipe is arranged so that the oil-water interface in the worst oil leakage state at the time of an accident is located above the outlet end within the drain pipe. An oil spill prevention mechanism for an oil dike characterized by having a long length.