APPARATUS AND METHOD FOR CONTAINING AND RECOVERING FROM OIL SPILLS

Abstract

A novel holder/dispenser for film-form polyethylene sorbent is a serially linked chain of holders to deploy sorbent material having a high affinity for oil for rapid early containment of an expanding oil spill on open water. Following containment and cleanup of the spill, the extended sorbent film is readily reeled in for incineration or for recovery and reuse of oil therefrom.

Description

FIELD OF THE INVENTION

This invention relates to a holder/dispenser for film-form polyethylene sorbent. In another aspect, the invention relates to a system and method for deploying such sorbent materials against oil spills on open water to contain, collect and recover spilt oil.

In U.S. Pat. No. 5,451,325 (Herkenberg) the remarkably high weight/weight pickup affinity of polyethylene film for crude oil is described. That patent describes in particular the use of polyethylene film sheets or elongate helically wound belts for protecting shoreline water/land areas from approaching oil spills and for early assistance through delaying the spread of oil on water or onto land by deployment near the source of an oil spill or leak. U.S. Pat. No. 5,451,325 is hereby incorporated by reference for its teachings on the properties of polyethylene film as a sorbent for oil.

SUMMARY OF THE INVENTION

It is a principal objective of the present invention to provide a system for rapid deployment of such substrates to surround, contain and reduce the areal extent of an oil spill on open water and to recover a significant portion of the adsorbed oil for separation and re-use.

The system of the invention comprises at least one buoyant holder for a roll of film-form polyethylene substrate, the roll being attached to and wrapped around a hard, buoyant plastic core, such as engineered polypropylene. The holder has a front wall and a rear wall, an elongate rod member positioned inside the roll of sorbent, and means for fixing the sorbent roll to the inside of the rear wall so as to prevent longitudinal motion of the roll relative to the walls of the holder and rotational motion of the roll about the axis of the rod member, as sorbent film is pulled away from the roll in an axial direction.

The front wall of the buoyant holder includes a central aperture through which sorbent film may be pulled out of the holder in an axial (tansgential) direction, to form an elongate rope of helically twisted film. Means are provided for securing the core of the roll of film to the holder, which include attachment means extending perpendicularly from the outer surface of the rear wall of the holder, to tie or otherwise connect the front end of sorbent film which extends from the front wall of a second such holder. Similar end-to-end connections are made for subsequent adjacent pairs of holders, allowing for a sequential film dispensing operation.

It is a further objective of the present invention to provide a system for deploying a film-form polyethylene substrate to pick up subsurface oil which having been broken down with dispersants has formed contaminating masses of oil on or near the bed/floor of the body of water. A plurality of dispensers can be connected in series so that, in use, when the film of one roll has been fully extended and exhausted from the first holder, film will be deployed from the next holder in the series.

BRIEF DESCRIPTION OF THE DRAWINGS

In drawings which illustrate the invention:

FIG. 1 is a schematic side elevational view of a holder first embodiment of a substrate film holder, according to the invention, showing helically winding film extending from the holder in the direction of arrow A;

FIG. 2 is a front perspective view of the holder with mounted film of FIG. 1;

FIG. 3 is a vertically cross-sectional view through the long axis of the apparatus of FIG. 1;

FIG. 4 is a perspective view from above and to the rear of a second and currently preferred embodiment of a substrate film holder according to the invention;

FIG. 5 is a perspective view from below and to the front of the substrate film holder of FIG. 4;

FIG. 6 is a view of the film holder of FIG. 5 with the roll of substrate removed from the spindle;

FIG. 7 is a an underside view of the substrate film holder of FIG. 6;

FIG. 8 is a schematic illustration of the use of the invention in containing oil spilling from a vessel on open waters;

FIG. 9 is a schematic illustration of a vessel for deploying fresh sorbent and for picking up loaded sorbent for end processing; and

FIG. 10 is a schematic illustration of the use of a vertically extending, bottom-weighted sheet of OILSORB™ in removing submerged accumulations of oil.

This sequential dispensing operation is achieved by a short length of axially twisted film protruding through a central dispensing aperture in the front wall of the second holder/dispenser to a central position on the rear wall of the first holder. Similar end-to-end connections are made for subsequent adjacent pairs of holders.

DETAILED DESCRIPTION OF THE INVENTION

As fabricated, the OILCLING™ sorbent used in apparatus according to the invention is a double film of high-extension (HE) polyethylene film, the two sheets being laminated together along their corresponding outer edges. Each sheet of the laminated film includes a plurality of small pierces therethrough, so that in the process of adsorption, oil is admitted between the inner faces of the component films of the sorbent double sheet.

OILCLING™ sorbent material may be provided in 2,000 foot rolls having an overall diameter of 6 inches, with the film sorbent wrapped tightly about a hollow plastic central cylindrical core of diameter 2 inches and an end-to-end length of 10 ¼ inches. The tail edge of the sorbent roll has been firmly attached to the buoyant core by a strong adhesive, so that considerable tension would be required to pull the end of OILCLING free from the roll core once the full length has been played out in use.

(a) Holder/Dispenser for Sorbent

A particular advantageous feature of the holder-dispenser of my invention is that a number of dispensers, each containing an axially mounted roll of OILCLING™ sorbent (typically 2,000 feet in length) can be operatively connected in series with a number of dispensers.

FIGS. 1 to 3 show an earlier version of a single holder-dispenser 10A having a side wall 11A and parallel front and rear walls 12A and 13A, which include circular openings 14 and 15 respectively. The designation “A” simply distinguishes the first-deployed of a series of identical dispensers 10B, 10C, etc.

A single roll 16 of OILCLING is secured in holder-dispenser 10A by means of a rigid roll core tube 18 which is externally threaded at its rearmost end. The roll is positioned so that tube 18 is aligned with aperture 14 and can be held in place by twisting the tube tight against an internally threaded cap 20 which fits against the outside of dispenser wall 13A and over circular opening 15. A flange or washer 22 held firmly against the front of tube 18 by screw 22a prevents front-rear movement of the body of roll 16 in use.

FIGS. 4 to 7 show a currently preferred two-piece injection molded holder-dispenser 10B having a side wall 11B with merges along the top and bottom thereof with perpendicular top and bottom part-panels 11B₁ and 11B₂ which add structural support. In lieu of the rearwardly threaded roll core tube 18 and threaded cap 20 of holder-dispenser 10A, a spindle 18B with cruciform cross-sectional shape is provided with an integral circular retaining piece at the front end thereof which in use bears against the core of the substrate roll as best seen in FIG. 4.

In assembly, substrate roll 16 is slid on to spindle 18B and positioned within the walls 11B, 12B, and 13B. As with the dispenser of FIGS. 1 to 3, the currently preferred version of FIGS. 4 to 7 also includes a keyhole piece 24B. Keyhole piece 24B engages the rear end of spindle 18B by a stop-lock mechanism (not shown), operable so that a quarter-turn of the flat keyhole piece 24B pulls spindle 18B and the roll of sorbent carried thereon into stabilizing abutment against wall 13B of the holder, so that undesired rotation or axial translation of the roll are prevented.

To prepare a sorbent holder 10 for deployment, the outermost layer of the sorbent roll at the front of the holder is pulled at its perimeter forwardly and radially inwardly through opening 12, so that a loosely coiled rope section 19A of sorbent protrudes through front aperture 14. Pulling forwardly on rope section 17 in the direction of arrow A causes the OILCLING™ sorbent to unwind from the rear and deploy in the axial direction with very little resistance, as the tangential film-to-film frictional force is very small. The pulling force is generated when the holder floats in oil-covered water and the holder is drawn by a vessel in the direction B by virtue of the oil sorption into the free end 17 of the sorbent.

As best seen in FIGS. 1, 2 and 3, the operative connection between dispenser 10A and 10B is made by tying a front rope-end 19B of sorbent from holder/dispenser 10B through the keyhole piece 24 affixed to threaded cap 20 of holder/dispenser 10A.

(b) Deployment of Holders to Contain an Oil Spill

FIG. 8 schematically illustrates the use of the invention in containing an oil spill. A vessel 28 whose oil containers have been breached will produce an expanding oil spill. In FIG. 8, for a wind direction W, perimeters A, B, C, D, E and F illustrate the aerial expansion after one, two, four, six, eight and twelve hours respectively. As illustrated in FIG. 9, an oil pick-up boat 30 equipped with a plurality of dispensers 10A, 10B, 10C, etc. as described above proceeds at a distance around the outermost extent F of the oil spill, deploying cumulative lengths L1, L2, L3, etc. of sorbent to surround and contain the spill. When the lines of sorbent meet the perimeter of the expanding oil spill oil is picked up by the deployed sorbent.

As illustrated in FIG. 9, boat 30 can pick up oil-laden OILCLING™ sorbent at the front which can be compressed to extract and reclaim much of the oil or the loaded OILCLING can be cut into suitable pieces for incineration.

To the rear of boat 30, a line of fresh OILCLING is laid down and the boat maneuvers in a gently decreasing spiral, picking up the spent OILCLING and laying down fresh OILCLING in patterns of decreasing largest diameter, so that the oil is effectively hemmed in as it is being removed from the spill.

FIG. 8 also illustrates a helicopter 40 carrying out the same operation, deploying sequential containers 10′A, 10′B, 10′C, etc. about the spill.

(c) Capture and Pickup of Submerged Oil

In a number of recent oil spills, attempts to deal with the problem by breaking up the oil with surfactants have not only proved ineffective, but have been found to result in partially degraded oil sinking toward the bottom of the water. FIG. 10 schematically illustrates the method of my invention for dealing with oil spills of this kind with OILCLING™ sorbent by arranging a generally vertical “curtain” of sorbent 16 with an array of weights 50 attached by clips or otherwise to the bottom horizontal edge of the sorbent. This curtain extends laterally wider than the oil spill and is impinged on the spill by the slow motion of boats 32 and 34 which are synchronized in their motion forward to maintain the long dimension of the curtain perpendicular to the forward motion.

The laminated and pierced polyethylene films are of OILCLING pickup the oil and, once laden to maximum capacity with oil the sorbent 16 can be removed for incineration or recovery of the oil therefrom.

Claims

1. A rigid, buoyant holder/dispenser for a roll of film-form polyethylene substrate, comprising: a supply of film-form polyethylene substrate in the form of a roll attached to and wrapped around a hard, buoyant plastic core;a rigid, buoyant housing having a top wall, and a front and a rear wall integral with and extending downwardly and parallel from said top wall; means for securing the sorbent roll against an inside face of the rear wall to prevent longitudinal motion of the roll relative to the long axis of the holder,said front wall of the holder including a central aperture through which sorbent film may be pulled tangentially from the roll and out of the holder in an axial direction, thereby forming an elongate rope of helically twisted film substrate; andattachment means extending rearwardly from the housing for connection to the front end of a helically twisted film of sorbent extending from the front wall of a second holder/dispenser.

2. A holder/dispenser according to claim 1, wherein said means for preventing longitudinal and rotational motion of the roll of substrate comprises a rigid roll cord tube externally threaded at its rear most end; a central aperture through the rear wall of the holder-dispenser to receive at least part of the threaded portion of the roll cord tube;an internally threaded cap to receive said threading on the roll cord tube so that the tube may be secured in place by twisting the tube end tightly against said cap; anda flange or washer screwed tightly against the front end of the rigid roll cord tube.

3. A holder/dispenser according to claim 1, wherein said means for preventing longitudinal and rotational motion of the roll of substrate comprises: a spindle with cruciform cross-sectional shape having at the front end thereof an integral circular retaining piece to bear against the core of a substrate roll installed on the spindle; and,where said attachment means is in step-wise selective locking engagement with the rear end of the spindle and is operable on tightening to pull the spindle and the roll of sorbent carried thereon into stabilizing abutment against the rear wall of the holder.

4. A system for deploying sorbent materials to surround and contain oil spills on open water, comprising a plurality of holders/dispensers according to claim 1 serially connected by tying the first portion of film drawn through the front aperture of one holder/container according to claim 1 to the attachment member extending from the rear wall of a like frontwardly adjacent holder/dispenser.

5. Use of a system according to claim 3 to contain an oil spill, by providing a vessel equipped with a system of dispensers to lay down a ribbon film-sorbent circumscribing the oil spill or leak.