JPS5828158B2 - Ballast tank naino - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a part of a tanker's storage tank for crude oil, etc. as a dedicated ballast tank, and stores crude oil in a group of envelope-shaped oil storage bags that are kept floating in the water inside the full tank at all times. There is a device for storing oil, etc. in a ballast tank to prevent ocean pollution due to oily ballast water and to reduce the reduction in the loading capacity of a tanker due to installation of a dedicated ballast tank.

Conventionally, this type of pollution prevention device is a box-shaped device with surfaces parallel to the walls, placed at predetermined intervals around the four circumferences of an oil/ballast tank, and on the top and bottom walls, and is impermeable to seawater and crude oil. a screen body made of a flexible web material; and a plurality of perforated ears attached to the screen body at positions that engage a number of mounting brackets installed on the inner surface of the dual-purpose tank. There is a contamination prevention screen for the dual-purpose tank.

However, in this type of equipment, when draining the oil inside the screen, a part of the top of the screen is removed from the mounting bracket, so a flexible screen wall that collapses from the top is required. , there is a risk that the pipe member opening connected to the suction pipe at the bottom of the screen may be blocked and oil discharge may be hindered.

In addition, the box-shaped pollution prevention screen, which is floating on the water surface of the tank and fixed by numerous mounting brackets on the surrounding walls, is susceptible to oil displacement within the screen caused by the heeling of the ship during voyage in rough weather. The stress other than the buoyancy force applied to the screen is
We cannot avoid adding more.

The present invention obstructs oil discharge as described above, and
This eliminates stress other than buoyancy and requires the screen material to be stronger, making it easier and more economical.
It is an attempt to achieve the original purpose.

Next, one embodiment of the present invention will be described based on FIGS. 1 to 4.

The storage device for oil, etc. in a ballast tank of the present invention is such that only the lower part thereof is connected to the bottom of the ballast tank 1 with an anchor rope 8, and the ballast water 11 in the tank is always full.
A plurality of watertight, flexible envelope-shaped oil storage bags 9 made of nylon cloth or the like coated with rubber on both sides are held in the ballast tank 2 while floating inside and protected by water.
Crude oil, etc., is poured into the tank, and the oil is drained and stored.

In addition, the upper part of the oil storage bag 9 is connected to the oil supply/drainage port 5 with each float by a communication path 6, and the connection path 6 is also connected to the oil supply/drainage port on the deck via a flexible oil supply/drainage pipe 7. Connected to the oil pump.

When a tanker loads crude oil 10, etc. into a ballast tank, as shown in Figure 4C, the oil supply and drain pipes are connected to a watertight, flexible, envelope-shaped oil storage bag 9 floating in a deflated state in the ballast water 11. 7. Crude oil 10 and the like are sequentially injected through the communication channel 6 and the oil supply/drainage port 5 by the oil pump on the deck, as shown in Figure 4, a.

In this case, the required pump pressure of the lubrication pump is a relatively small extra pressure equivalent to the difference in specific gravity between the ballast water 11 and crude oil 10, etc., which is necessary to eliminate the water pressure applied to the deflated oil storage bag 9. Become.

Also, as the oil storage bag 9 is filled with oil, the ballast tank 2'
Allow excess water inside to overflow.

The bottom of the oil storage bag 9 into which the crude oil 10 has been press-fitted is fixed to the tank bottom only with the anchor rope 8, and is constantly maintained floating in the water inside the full ballast tank Z, so it is protected against stormy weather. Regardless of the inclination of the ship during the voyage, the ballast water 11 is not displaced, and therefore the force applied to the oil storage bag 9 can be limited to a stress equivalent to the buoyancy of the crude oil 10 and the oil storage bag 9.

In addition, during the cargo voyage of the Kushika, as shown in Figure 2.3.4 a, in addition to the center tank 1 storing crude oil 10, etc., the separate ballast tank 7, which was used as the side tank 2, becomes contaminated with oil. By storing crude oil 10, etc. in 9 groups of oil storage bags held in water filled with water, it is possible to reduce the reduction in the loading capacity of crude oil 10, etc. due to installation of a separate ballast tank 7 of a tanker.

When unloading crude oil 10, etc. in ballast tank r from a tanker, the condition shown in Figure 4 a (this ballast tank 7
The crude oil 10, etc. in the oil storage bag 9 held in the water of The oil is pumped up one by one using the drain pump on the deck.

In this case, as the oil 10 in the oil storage bag 9 is pumped up, as the oil in the oil storage bag 9 is drained, the oil storage bag 9 collapses sequentially and orderly from the bottom to the top, as shown in FIG. is naturally collected at the upper part of the oil storage bag 9 by the surrounding water pressure.

The lower part of the oil storage bag 9 (the crude oil 10 that has been collected at the upper part without remaining and is subjected to water pressure is - the oil supply/drainage port 5, the communication passage 6,
Through the oil supply and drain pipe 7, the oil storage bag 9 is opened with the help of water pressure.
Oil can be drained smoothly and easily without the flexible wall blocking the oil supply/drain port 5.

The required pressure of the oil drain pump is reduced by the amount of water pressure around it.

Further, unloading of crude oil 10 etc. from the oil storage bag 9 in the ballast tank 2' is carried out while injecting into the ballast tank 2' an amount of ballast water 11 corresponding to the amount of unloaded crude oil 10 etc.

When the tanker is voyaging with no cargo, as shown in Figure 4C, the oil storage bag 9 in the ballast tank Z is in a deflated state, floating in the ballast water 11 in the tank, which is full to the ballast tank 2.
Since the crude oil 10 and the like are separated from the ballast water 11, there is no risk of oil spillage in the ballast water 11.
The ballast tank 2' incorporates the oil storage bag 9 without compromising its original mission.

The present invention can be carried out as described above, so a part of a conventional tanker's crude oil etc. loading tank is used as a ballast tank, crude oil etc. is stored in an oil storage bag floating in the water inside the full tank, and oil spill ballast is carried out. It goes without saying that measures will be taken to prevent marine pollution caused by water (water) and to reduce the reduction in tanker loading capacity by installing dedicated ballast tanks.

Further, according to the present invention, the force applied to the oil storage bag is only a small stress equivalent to the buoyancy of the oil and the oil storage bag, and the requirement for flexibility is not so great, making selection of the oil storage bag material easier and more economical.

Furthermore, when draining oil, the crude oil in the oil storage bag is sequentially moved from the bottom to the top without the need for extra work such as removing some fittings, by borrowing the power of surrounding water pressure. The oil can be collected in an orderly manner without leaving any residual oil, and can be drained smoothly and easily.

[Brief explanation of drawings]

Figure 1 is a tank plan layout of a large ocean-going tanker;
The figure is a plan view of the side tank (separate ballast tank), Figure 3 is a cross-sectional view of the tanker, and Figure 4 is a vertical cross-sectional view of the separate ballast tank. , during unloading, and C indicates the state during unloaded voyage. Code explanation, 1...Center tank, 2...
...Sight tank, τ...Separate ballast tank, 3...Clean water tank, 4
... Slop tank, 5 ... Oil fill and drain port with float, 6 ... Connection path, γ ...
Flexible oil supply and drainage pipe, 8...Anchor rope, 9...Watertight flexible envelope-shaped oil storage bag, 10
...Crude oil, 11...Ballast water.

Claims (1)

[Claims] 1 The lower part of each ballast tank is connected to the bottom f of the ballast tank, and the upper part of the tank is connected with a connecting channel equipped with a flexible oil supply and drainage pipe that connects the oil supply and drainage port equipped with a float, so that the ballast tank is constantly floating in the water and is surrounded by water. An oil storage device in a tanker's ballast tank, which can store oil by pouring it into a plurality of watertight, flexible, envelope-shaped oil storage bags that are protected and held in the ballast tank.