GB2235164A - Preventing liquid particularly oil spillage - Google Patents

Abstract

A method of preventing the escape of a liquid from large containers to avoid ecological disasters e.g. oil from ocean tankers or land based tanks comprises retaining the liquid by temporarily sealing vents 5, 7 by mechanically, manually, or electrically operated valves 14, 15. A magnetic breach mat may be used in conjunction with the method of holding back the liquid when a sea-going bulk liquid carrier is holed at 13. <IMAGE>

Description

mBE w OIL CURTAIN AND THE MEANS TO RETAIN A LIQUID IN A TANK OR VESSEL OR SHIP WHEN THE SAID CONTAINERS ARE DAMAGED AND/OR HOED.

DIatzI This invention concerns means for use in retaining liquids by means of vacuum to hold a liquid in a vessel when the vessel or container is damaged or holed.

This invention will hold a liquid in a container until such time as a repair can be carried out.

To take for example the problem of a large oil tanker which has run aground and has a large hole at the bottom of the ship. The oil slick and damage to the environment caused by this is so ecologically damaging to be unbelievable.

Also, to be taken into consideration is the cost of the loss of oil and the damage to the vessel which is usually a 'write off'. The same kind of disaster can happen when a land based tank is damaged. The objective of this innovative method is to prevent this type of disaster.

This can be done by simply closing the expansion pipes and/or air vents by means of manually operated valves and/or electrically operated valves, or valves of any kind and made of any materials. In a tanker for example, if the hole is below vater level, and if all entries into the particular tank or tanks are closed it would be impossible for the liquid to escape. The benefits from this invention would be immense.

A ship or sea going liquid containing tanker, when holed, more often than not also rips up the side and often has more than one hole in it. This then creates a further problem so it is proposed that an apparatus to be known as an "oil curtain" be brought into use. The problem being that the bottom pressure exerting upwards through the one hole or other punctures in the hull forces the liquid or oil which readily floats out through the top of the split in the vessel's side.

This can completely empty the vessel of its cargo even if the decks are sealed.

However, the cargo of oil does not came out of the vessel under much pressure as most of the force is pressing upwards towards the sealed deck and the oil, which of course readily floats, does not want to leave its container and in fact, only only does so from the top of the crack or split. This means that it can be easily kept in by simply lowering a magnetic curtain down the outside of the vessel until it reaches the level of the bottom of the vessel. Although it does not have to go below the vessel it is perhaps better if it hangs lower by a few feet.

It is proposed that the proposed oil curtain :- will be made of a durable material such as plastic or of any material deemed necessary for strength and durability so as to complete its task; will be magnetic in the necessary places as to make a seal where needed; will have runners fitted so as to run it down the side of the vessel; will be fitted to the vessel in any way, shape or form as to carry out its function; will have draw off tube connections at various points so as to allow the cargo to be transferred to another vessel - if this is situated on or near the water line, the bottom pressure will force te cargo out under ccntrol.

Furthermore, it would follow that if any land based tank or liquid container outlet or inlet were situated just below a water line, and if the vent pipes were sealed, in cases of damage, the liquid contained would not escape. If the outlets were not below the water line when the vents and expansion pipes were sealed the liquid would still stop but if this is was a volatile or poisonous liquid it would obviously be safer under water.

Xf a tank or container was holed and the air vent sealed concern may arise over thoughts that the container may collapse in on itself. However this only happens when syphonic action takes place - when the draw off is from the top of a container to an outlet below the bottom of the said container. If, as in most land based tanks the draw off is located in the bottom third of the tank (Fig 3) then the liquid will not leave the vessel if damage to the valve occured (Figs 3 & 4) and the air vent temporarily sealed.

The means to remove the oil or liquid fran a ship/tanker would be by means of a pump. A pipe would be placed through the hole in the vessel up to the top of the retained liquid. This would then be pumped out, with sea water automatically replacing it. This would then leave the vessel stable! The invention will now be further described by way of example only , with reference to the accompanying drawings in which: Figure 1 .

Shows a laden tanker with separate tanks. Two of these are holed (2 & 3) after having run aground. In these circumstances the oil or liquid would gush out of the hole (4), and air would rush in through the expansion or air vent (5 & 7).

The vessel would now become unstable and in danger of breaking up and losing the rest of its cargo in holds numbered 8,9,10 and 11, thus causing an enormous oil slick (12).

Figure 2 Shows a section of a ship/tanker which has been holed (13). The hole lies across holds 2 and 3 which have two air vents (5 & 7). These have now been closed by means of valves (14 & 15). It is now impossible for the bulk of the oil to escape and the ship/vessel is still stable.

Figure 3 Shows a tank situated on land. The tank (l) has a broken valve (6). Normally, the liquid would pour out of outlet (4). However, the valve (3) on expansion pipe (2) has been temporarily closed either by mechanical or manual or electrical means, and will therefore hold the liquid (5) in the container until a repair or a fire has been dealt with.

Figure 4 Shows the proposed oil curtain in place on the vessel (1). The proposed means of attachment is by magnetic strip shown by the dotted lines (2). The curtain will be inflated by the oil taking it away from any protruding plates. The proposed overhang at the base (3) will give swell relief and take the strain away from the weakest point of the magnets (3 & 4). The strongest point is at 5.

Figure 5 Shows the proposed oil curtain with the magnetic strip (1), the length of which gives it its strength. ~ The curtain (2) made of a strong resilient material with various draw off points (3). These may or may not be required.

Claims (10)

QAMS

1. A method of preventing the escape of a liquid from a large container such as a sea going tanker or a land based liquid containing tank.

2. A method as claimed in Claim 1 and preventing the escape of a liquid from a large container to effect repairs by means of holding back the liquid by sealing the open vents.

3. A method as claimed in Claims 1 and 2 of preventing an environmental disaster by the retention of liquids in large containers by means of sealing open vents temporarily by mechanical, manual or electrically operated valves.

4. A method substantially as herein before described with reference to and as illbstrated in Figures 1, 2 and 3 of the accompanying drawings.

5. A method as claimed in previous claims of isolating the liquid by means of creating a vacuum by sealing open vents on a vessel to prevent the said liquid escaping in the event of damage to a container.

6. A means of preventing a liquid cargo dispersing into the sea by means of using an oil curtain in conjunction with Claims 1,2,3,4,5.

7. An oil curtain as in Claim 6 being made of resilient material.

8. An oil curtain as claimed in Claims 6 and 7 which can be attached to the hull of a vessel/ship preferably by magnetism.

9. An oil curtain as in Claims 6, 7 and 8 substantially as hereinbefore described referring to drawings.

10. An oil curtain herein described and may or may not have compartments that could be filled with air to give it various shapes.