US3863694A

US3863694A - Deployable system for containing oil spills

Info

Publication number: US3863694A
Application number: US291255A
Authority: US
Inventors: Edwin N Fisher
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-09-22
Filing date: 1972-09-22
Publication date: 1975-02-04
Anticipated expiration: 1992-02-04
Also published as: CA985919A

Abstract

A system is described for containing oil spills or leaks from small oil storage tanks. The system comprises a diaphragm of polyvinyl chloride, synthetic rubber or the like, formed in a circular pattern of radius approximately equal to the radius of the storage tank plus its height. The circular diaphragm is placed under the tank and centered with respect thereto. The edge of the diaphragm is pleated and fastened to a tension ring which surrounds the upper part of the tank and is held in place by friction or other suitable means. When a leak occurs, the tension ring releases and slides down the tank as the diaphragm fills with the oil escaping from the tank. In the event of tank failure, the diaphragm is capable of containing the entire contents of the tank in its fully deployed position. A constraint dike may be used, although its use is entirely optional, not to structurally reinforce the diaphragm since such reinforcement is not needed, but rather to protect the tank and undeployed diaphragm from mechanical damage.

Description

United States Patent 191 Fisher 14 1 Feb. 4, 1975 1 DEPLOYABLE SYSTEM FOR CONTAINING OIL SPILLS {76] Inventor: Edwin N. Fisher, 7632 Wandering Dr.. Anchorage, Alaska 99502 22 Filed: Sept. 22, 1972 21 Appl. No; 291,255

[52] US. Cl. 150/1, 150/52 R [51] Int. Cl 865d 65/02 [58] Field of Search 150/1. 52 R; 5/96; 16/57; 92/153, 169

[56] References Cited UNITED STATES PATENTS 2,035,384 3/1936 Hinchliff 150/52 R 2,115,654 4/1938 Swofford..... 150/52 R 2,440,569 4/1948 Baldwin 150/52 R 2,610,757 9/1952 lrvine 150/52 R 2,685,318 8/1954 Merkle 150/52 R Primary ExaminerWilliam 1. Price Assistant ExaminerR. E. Hart Attorney, Agent, or FirmBerman, Bishoff & Platt [57] ABSTRACT A system is described for containing oil spills or leaks from small oil storage tanks. The system comprises a diaphragm of polyvinyl chloride, synthetic rubber or the like, formed in a circular pattern of radius approximately equal to the radius of the storage tank plus its height. The circular diaphragm is placed under the tank and centered with respect thereto. The edge of the diaphragm is pleated and fastened to a tension ring which surrounds the upper part of the tank and is held in place by friction or other suitable means. When a leak occurs, the tension ring releases and slides down the tank as the diaphragm fills with the oil escaping from the tank. In the event of tank failure, the diaphragm is capable of containing the entire contents of the tank in its fully deployed position. A constraint dike may be used, although its use is entirely optional, not to structurally reinforce the diaphragm since such reinforcement is not needed, but rather to protect the tank and undeployed diaphragm from mechanical damage.

9 Claims, 13 Drawing Figures FIG. 2.

Pmmiu w 4W5 3.863 .694

PATENIED FEB 4 I975 SHEU 3 OF 3 DEPLOYABLE SYSTEM FOR CONTAINING OIL SPILLS This invention relates generally to containment systems for oil spills and more specifically relates to a system including a deployable diaphragm for containing oil spills and leaks from small oil storage tanks, i.e., those having a capacity of under 500 barrels. The system described, however, can be applied to any storage tank or the like for containing leaks or spillage of the contents thereof. Where quantities of heating and diesel oil are stored in above ground oil storage tanks, a serious problem, from both an ecological and economic standpoint, has been the leakage of oil onto the terrain surrounding the tank, either by reason of tank failure or tank overflow during the filling process.

The conventional approach to the oil spill containment problem has been to use a dike system which surrounds the storage apparatus and which is impervious to the passage of oil therethrough. In such systems, however, subsequent to a spill, cleanup problems of major proportion exist. The disposal of the salvaged oil normally requires that it be burned which results in serious air pollution. In addition, of course, the seepage of the oil into the terrain surrounding the storage means creates a serious problem of soil and water pollution. Further, the conventional dike system does not have the capability of capturing the spillage from small leaks, which might go undetected for periods of many months and possibly years.

Another approach in the past has been to provide a fully lined dike system. but this approach also suffers from serious disadvantages. For example, in regions of substantial rainfall, such dike systems filled with water, making them totally ineffective for their intended purpose. If valving is provided to remove the accumulated rain water, it requires continual attendance and is subject to freezing and mechanical breakdown, as well as other causes of failure. Accumulation of snow and ice also substantially reduce the capacity of the dike. Further, the liner itself must be protected from mechanical damage and this is usually accomplished by placing a layer of sand over the liner. Such a protective measure, obviously, makes useful salvage of spilled oil virtually impossible due to the contamination of the oil by the sand.

Accordingly, it is a principal object of the present invention to provide a new and improved oil spill containment system which eliminates the above-described disadvantages of the systems presently in use.

A further object of the invention is to provide an oil spill containment system which is particularly useful with small oil storage tanks, i.e., those having a capacity of under 500 barrels.

Another object of the present invention is to provide an oil spill containment system which is capable of salvaging the spilled oil for future use.

Still another object of the present invention is to provide an oil spill containment system which salvages the oil from a spill with no attendant air, water or soil pollution.

Yet another object of the invention is to provide an oil spill containment system which has a capability of capturing the oil spilled from small leaks.

Still another object of the present invention is to provide an oil spill containment system in which the system itself provides an automatic indication that a leak has occurred.

Another object of the present invention is to provide an oil containment system which can perform effectively even when the terrain surrounding the oil storage means is covered by substantial accumulation of ice or snow and in regions of heavy rainfall.

Briefly, the oil containment system of the present invention comprises a deployable diaphragm formed of a suitable plastic, synthetic rubber or other like material formed in a circular pattern and having a radius approximately equal to the radius plus the height of the storage tank. This disk of material is placed under the tank and centered with respect thereto. The edge of the material is pleated and fastened to a tension ring which surrounds the tank and is held in place by friction or other suitable means, such as counterweights, near the top of the tank. When a leak occurs, the tension ring releases and commences to slide down the tank and the diaphragm commences deployment as it fills with escaping oil. The deployment of the diaphragm, which can be seen from many miles, particularly from the air, serves as a visual indication that a leak has occurred and in the fully deployed condition, the diaphragm is capable of containing the entire contents of the oil storage tank. A pervious constraint dike may be used with the oil spill containment system of the present invention. Thus, when the diaphragm is in its fully deployed condition, the constraint dike is sealed and no contamination of soil, water, or fuel results. However, the constraint dike is not necessary nor is it provided to add strength to the diaphragm. It may simply be used to protect the tank and the undeployed diaphragm from mechanical damage caused by vehicles and the like. Thus, the use of the deployable diaphragm oil containment system of the present invention prevents soil, water and air pollution; substantial financial loss due to unrecoverable fuel oil; and personal hardship resulting from the failure of a bulk oil storage tank.

Other objects, advantages and features of the invention will become apparent through a consideration of the following detailed description thereof taken in conjunction with the drawings, in which:

FIG. I is a top plan view of the oil containment system installed on a conventional oil storage tank with the constraint dike optionally shown;

FIG. 2 is a front elevation of the oil containment system of the present invention, as shown in FIG. 1, with half the constraint dike removed for clarity;

FIG. 3 is a partial longitudinal sectional view taken on the line 3-3 in FIG. 2, looking in the direction of the arrows;

FIG. 4 is a front elevation showing the conventional storage tank with the exoskeleton for guiding the ten sion ring as the diaphragm is deployed, in place;

FIG. 5 is a front elevation of the storage tank of FIG. 4, with the oil containment system in place and the diaphragm partially deployed;

FIG. 6 is a front elevational of the oil storage tank of FIG. 5, showing the diaphragm fully deployed;

FIG. 7 is a top plan view of the storage tank shown in FIG. 6, with the diaphragm fully deployed;

FIG. 8 is a front elevation of the storage tank of FIG. 5, showing the fully deployed diaphragm under conditions where ice surrounds the storage tank;

FIG. 9 is a front elevation of the storage tank shown in FIG. 5, with the diaphragm fully deployed but wherein a snow drift has filed up against the side of the storage tank;

FIG. is a partial transverse section taken on the line 10-10 of FIG. 2, and looking in the direction of the arrows;

FIG. 11 is a partial sectional view, similar to FIG. 3, but including additional means for preventing the entrance of rain or snow into the deployable diaphragm;

FIG. 12 is a crosssectional detail showing the use of one possible through diaphragm penetration for removing oil from the storage tank; and

FIG. 13 illustrates a variation in the through diaphragm penetration shown in FIG. 12.

Referring now to FIGS. 1, 2, 3 and 10, there is illustrated the deployable containment system of the pres ent invention. Deployable diaphragm 10, which is formed as a circular piece of material, such as polyvinyl chloride or synthetic rubber of radius approximately equal to the radius plus the height of oil storage tank 21, is pleated, as indicated by reference numeral 11, and suspended from tension ring 12 by rings 13 and hooks 23 which engage eyelets 22 in the outer periphcry of the deployable diaphragm. lnterposed between diaphragm 10 and the outer surface of oil storage tank 20 is an exoskeleton comprising ribs 19 extending at an angle to the longitudinal axis of the barrel and structurally supported by upper and lower rings 20. The structure and function of the exoskeleton will be described in more detail hereinbelow in connection with FIGS. 4, 5 and 6.

During installation of the diaphragm l0 and tension ring 12, the tension ring is rotated about the longitudinal axis of storage tank 21 to draw the diaphragm material snugly against the outer surface of the tank and thus prevent its free movement in high winds or other turbulent conditions. The diaphragm 10, in addition to the above-described twisting caused by the tension ring during installation, may be further restrained in its installed or undeployed position by use ofa spring-loaded or bungee gasket 18. More than one such gasket may be employed, as desired, and evenly spaced in the direction of the longitudinal axis of the tank.

Through diaphragm penetration 17 is provided which allows the user of the storage tank 21 to remove the stored fluid therefrom. This detail will be more fully explained below in connection with FIG. 12. Surrounding the oil tank 21 at a distance equal to the radius of the diaphragm in its fully deployed position, may be constraint dike 15 comprising sand bags 16 or the like. However, it should be realized that the constraining walls of the dike 15 may be made of any readily available material such as grave] or water filled oil drums placed directly on the natural ground cover, since in the operation of the oil containment system of the present invention, it is not necessary that the dike be impervious. Moreover, as pointed out hereinabove, the dike 15 is not provided for structural reinforcement, but rather simply to protect against mechanical damage. Thus, in areas where there is little likelihood of mechanical damage or fire exposure, constraining dike 15 may be totally eliminated.

Tank roof 14 may be optionally provided, no part of the present invention.

Referring now to FIG. 4, the exoskeleton which is installed against the sides of the tank 21 is shown comprising ribs 19 and structural supporting rings 20 formed of thin walled metallic or other suitable tubing.

but forms Similar material may be used for the construction of tension ring 12.

As indicated in FIG. 5, when a leak occurs, diaphragm 10 commences to deploy and fill with the escaping oil or other fluid. Tension ring 12 rotates as it drops down the sides of the tank. This rotation is beneficial for two reasons: First, it keeps tension ring 12 from dropping too rapidly; and secondly, it reduces the probability of the tension ring's binding against the tank. The angle of rods 19 of the exoskeleton are chosen so as to assist in the rotation of the tension ring 12. The rotation of the tension ring occurs because, as described above, the ring is rotated about the vertical axis of storage tank 21 during installation of the diaphragm 10 in its initial or undeployed position.

As illustrated in FIGS. 5 and 6, as diaphragm 10 deploys and finally reaches the fully deployed position shown in FIG. 6, bungee gasket 18 migrates toward tension ring 12 and, in certain instances, may even travel over tension ring 12 and on to the tank itself. However, it has been found that in no instance has the bungee gasket hampered the development of the diaphragm.

FIGS. 8 and 9 show respectively, typical instances of full deployment of diaphragm 10 in situations where the terrain surrounding storage tank 21 is covered with ice and where a snow drift has piled up on one side of the tank. As can be seen, ice and snow have absolutely no effect on the ability of the diaphragm to function. Diaphragm 10 deploys in precisely the same manner, as illustrated in FIGS. 5 and 6, except that the diaphragm settles over the top of the ice or snow. It has been found that diaphragm 10 may deploy normally over accumulated snow drifts of a height equal to at least one-third that of tank 21.

FIGS. 12 and 13 illustrate respectively a straightthrough diaphragm penetration 17 for removing oil from the interior of tank 21 and through diaphragm penetration 28 which extends through and under the ground surrounding tank 21. In FIG. 12 the penetration consists of sleeve 24 of the same material as diaphragm 10 and held in place by clamps 25. Similarly, in FIG. 13 the diaphragm penetration is effected by sleeve 26 formed of the same material as diaphragm 10 and held in place by clamps 27. When diaphragm 10 becomes fully deployed, it would simply settle over the pipe or valve in the same manner as described above with re spect to the ice and snow drift situation of FIGS. 8 and 9, respectively.

Referring now to FIG. 11, there is shown protective flashing 29 to prevent the entrance of rain and snow into the interior of diaphragm 10. Flashing 29 may be formed of the same material as diaphragm 10 and is held in place by strap 30 extending around the circumference of tank 21 and bungee gasket 18. Upon deployment of diaphragm 10, tension ring 12 slides from under flashing 29.

In certain applications of the present invention, it may be desirable to install a water condensate drain valve in the bottom of the diaphragm 10. However, this may be accomplished with standard off-the-shelf hardware which is presently used for so-called pillow fuel tanks. The same valve could be used to withdraw oil from the deployed diaphragm 10 in the event of a spill.

Installation of diaphragm 10 under the tank simply requires a resilient bed such as sand. The tank may rest directly on the diaphragm, assuming it has no sharp projections. or may be elevated slightly, using a grating to provide drainage for condensed water.

After the diaphragm has become fully deployed, as shown in FIGS. 6 and 7, it may be emptied, using the conventional valve, described above, and quickly and readily restored to its initial position. Moreover. the deployed diaphragm 10 may serve for an extended period of time as an emergency fuel tank.

There has thus been described a new and improved deployable containment system for oil spills which is economically and ecologically sound, which is of simple construction and which is readily installed. Moreover, as explained above, the deployment of the diaphragm provides a ready indication that a leak has occurred, so that proper corrective measures may be taken.

While specific embodiments of the present invention have been shown and described, it should be realized that variations therein will be readily apparent to those skilled in the art and it is. therefore, intended to be lim' ited only by the claims, as set forth hereinbelow.

I claim:

1. A deployable containment system for containing spills from a storage container, comprising:

a. a deployable substantially planar diaphragm formed of relatively flexible material and having a radial dimension substantially equal to the radial dimension plus the height of said container so that said diaphragm is capable of containing substantially the entire contents of said container;

b. said diaphragm disposed beneath said container and suspended from and extending substantially to the upper edge of said container; and

c. means for suspending said diaphragm from the upper edge of said container and holding said diaphragm substantially tightly against the outer surface of said container in the initially installed undeployed condition; so that any leak or spill of the contents ofsaid storage container will be contained within said diaphragm and said diaphragm will deploy downwardly and expose the surface of said container as it becomes filled with said contents.

2. The deployment containment system set forth in claim 1, wherein said means for suspending Comprises a tension ring positioned near the upper edge of said storage container and means for attaching one edge of said diaphragm to said tension ring.

3. The deployable containment system set forth in claim 1, wherein said storage container is substantially cylindrical in shape and said diaphragm is circular. having a radius substantially equal to the cross-sectional radius plus the height of said cylinder.

4. The deployable containment system set forth in claim 2, wherein said diaphragm is pleated and tightly held against the outer surface of said cylinder in the initially installed undeployed condition, so that said tension ring rotates as said diaphragm deploys.

5. The deployable containment system set forth in claim 2, wherein there is further provided an exoskeleton disposed between said diaphragm and said container for guiding said tension ring during the deployment of said diaphragm.

6. The deployable containment system set forth in claim 5, whrein said exoskeleton comprises a plurality of ribs disposed at an angle with respect to the longitudinal axis of said cylinder.

7. The deployable containment system set forth in claim 2, wherein said diaphragm is centered with re spect to the lower surface of said container. and the outer edge of said diaphragm is attached to said tension ring.

8. The deployable containment system set forth in claim 2, further including means for supporting said diaphragm in the undeployed condition.

9. The deployable containment system set forth in claim 8, wherein said means for supporting comprises at least one gasket disposed between said tension ring and the lower surface of said container.

l i i 1

Claims

1. A deployable containment system for containing spills from a storage container, comprising: a. a deployable substantially planar diaphragm formed of relatively flexible material and having a radial dimension substantially equal to the radial dimension plus the height of said container so that said diaphragm is capable of containing substantially the entire contents of said container; b. said diaphragm disposed beneath said container and suspended from and extending substantially to the upper edge of said container; and c. means for suspending said diaphragm from the upper edge of said container and holding said diaphragm substantially tightly against the outer surface of said container in the initially installed undeployed condition; so that any leak or spill of the contents of said storage container will be contained within said diaphragm and said diaphragm will deploy downwardly and expose the surface of said container as it becomes filled with said contents.

3. The deployable containment system set forth in claim 1, wherein said storage container is substantially cylindrical in shape and said diaphragm is circular, having a radius substantially equal to the cross-sectional radius plus the height of said cylinder.

7. The deployable containment system set forth in claim 2, wherein said diaphragm is centered with respect to the lower surface of said container, and the outer edge of said diaphragm is attached to said tension ring.