WO1981000122A1

WO1981000122A1 - Method and device for collecting oil or the like

Info

Publication number: WO1981000122A1
Application number: PCT/SE1980/000188
Authority: WO
Inventors: O Wessman
Original assignee: Wessman Dev Ab Olle; O Wessman
Priority date: 1979-07-09
Filing date: 1980-07-09
Publication date: 1981-01-22
Also published as: EP0032147A1

Abstract

A method and a device for collecting oil or the like wherein in magnetic particles (1) are brought into contact with the oil (2). The oil can then be collected due to the fact that the magnetic particles mixed with oil are attracted by a magnetic field generated by a magnet device (4). The magnetic particles can be separated from the collected oil for re-use.

Description

METHOD AND DEVICE FOR COLLECTING OIL OR THE LIKE

The present invention relates to a method and a device for collecting oil . The invention relates, in particular, to collect¬ ing oil at sea and from beaches but can also be used for collecting other liquids.

The method hitherto used for taking care of oil spills usually involves surrounding the spilled oil with oil booms, after which the oil is pumped or otherwise collected in special containers. The possibilities of effectively taking care of the oil by carrying out these previously known methods are unsatisfactory to say the least of it. It is also known to "combat" oil discharge by supply¬ ing special chemical agents which act on the oil so that it loses its floating capacity or causes the oil to be decomposed or to be dispersed, which results in the oil sinking. These latter methods are very unsuitable because they destroy animal and plant life for a long time on the affected part of the bottom.

All these methods are so imperfect that the oil floating freely around often cannot be removed quickly and effectively in any satisfactory manner before it has spread over a wide area or before it reaches surrounding beaches .

When the oil. approaches or has reached a beach, the methods available for dealing with the oil are extremely primitive, for example by using spades, buckets, plastics bags, scrubbing brushes etc.

The present invention provides a method and a device which effectively permit the collection of oil both at sea and on land, which can be done without any negative effect on animal and plant life. This is brought about according to the present in-

OMPI vention in that the method and the device have the fea¬ tures given in patent claims 1 and 6.

By bringing magnetic particles into contact with the oil and then collecting the particles mixed with oil by attraction to a magnet device, the possibility is provided of effectively collecting the oil from the water or from the land. The magnetic particles are pre¬ ferably thrown against the oil at high speed, in which case they are able to penetrate into the oil so that they are completely mixed with oil which accompanies them when the particles are displaced, under the attrac¬ tion of a magnetic field, in the direction of the magnet device creating the magnetic field.

The particles preferably consist of iron powder, iron pellets or flakes of a magnetic material , the pel¬ lets possibly being porous, which facilitates the picking up of low viscous oil. Each individual magnetic particle can, in certain cases, convey an amount of oil the weight of which considerably exceeds the weight of the particle. The particles discharged on the oil therefore do not necessarily need to be recovered directly to render poss¬ ible renewed use but can be collected with the oil and conveyed to collecting tanks.

When it is a question of a large oil discharge, it may be necessary, for practical reasons, to recover the particles continuously and use these for continuous use in collecting oil. For this purpose, a separating device is used, to which the particles mixed with oil are con¬ veyed and in which device the particles are separated from the oil .

In cold weather, the majority of crude oils are viscous. In order to render it possible to pick up this viscous oil , the use of larger heated particles is pro¬ posed according to the invention. As a result of the fact that the kinetic energy in the particles is great, the particles are able to penetrate even into viscous and sticky oil. In this case, it is possible that lumps or chunks of viscous oil may be mixed with such large - amounts of magnetic particles that whole oil lumps or chunks can be attracted to a collecting magnetic field. By means of the present invention it is even poss¬ ible to collect oil which is below the surface of the water. The oil situated below the surface of the water is mixed with magnetic particles, which are then at- tracted by a magnetic field from a magnet device extend¬ ing down below the surface of the water. The collecting magnet device can then consist of a stationary magnet member producing a magnetic flux which travels continu¬ ously upwards for an upward conveying effect of the par- tides mixed with oil. The magnet member may then appro¬ priately be included in a disc or tongue extending down into the water, which eliminates the need for a movable conveyor belt to lift the oil out of the water.

By means of the present invention, it is also poss- ible to facilitate the collecting of leakage oil in direct connection with a leaking vessel . A continuous stream of magnetic particles is released down round the whole vessel. Floating oil collecting devices, working with a magnetic field attracting the magnetic particles should then be placed round the vessel at a suitable distance apart. In this manner substantially all the leakage oil can be acted upon by the oil collecting de¬ vices, that is to say the oil is conveyed towards the oil collecting devices which are placed so close together that the oil cannot escape being attracted by one such device .

Alternatively, the method according to the inven¬ tion can be utilized so that magnetic particles are con¬ tinuously supplied to the oil from a leaking vessel in such a quantity that the oil sinks close to the vessel. In this case, the oil can be lifted up out of the water later by means of separate magnetic lifting means.

A suitable device for carrying out the method accord ing to the invention comprises a feeder for feeding the magnetic particles to the oil and a magnet device for collecting the magnetic particles mixed with oil .

A particularly effective device is obtained when the feeding of the magnetic particles and the collecting of the particles mixed with oil is effected from a hover- craft, in which case the stream of air which is directed downwards to support the craft contains the magnetic particles which are to contact the oil. In its simplest embodiment, this craft does not need to be provided with any magnetic collecting device for the magnetic particles mixed with oil , but the collecting of the oil can advan¬ tageously be effected by using a conventional vessel pro¬ vided with magnet devices for collecting the oil.

It is naturally also possible to dispose the oil- -collecting magnet devices in the hovercraft, but because of the great oil -collecting capacity of the craft, its collecting tanks for the oil are quickly filled. This means that a hovercraft with complete equipment for col¬ lecting the magnetic particles mixed with oil and poss¬ ibly also a device for separating oil from these for re-use of the particles, is mainly only used for collect¬ ing limited amounts of oil and where the oil can be ex¬ pected to cause or constitute considerable risks to the environment, or when the oil must be removed quickly and effectively from the surface of the water or the land. Thus, the hovercraft completely equipped for oil collec¬ tion can be used on land, particularly on beaches con¬ taminated with oil .

The size of the hovercraft can vary from large ocean¬ going craft to smaller, possibly unmanned radio-controlled craft, or to even smaller types, which can be cable-con- trolled for use in connection with beaches. For the direct clearing of beaches, a craft can be used which in size and shape is reminiscent of a conventional air- -cushion lawn mower. Such a small craft preferably in- eludes only a particle feeder and a collecting magnet device. The oil collected can be conveyed via a conduit to a collecting tank where a separator for recovering the magnetic particles can also be placed. These separ¬ ated magnetic particles are then returned to the craft via a conduit.

Oil clearing of sandy beaches, which is very diffi¬ cult to carry out today, can be effected very quickly and effectively with an air-cushion craft according to the invention. The supporting stream of air from the craft exposes or swirls up any oil which is present, against which the magnetic particles are to be thrown. The particles are then attracted to the magnet device in the craft and are conveyed through conduits to the collecting tank. This small craft is also suitable for removing oil from cliffs. The cliff is exposed to a gentle blasting by the striking of the particles against it, and the oil adheres to the particles and is removed to the magnet device of the craft.

The hovercraft mentioned above may appropriately be equipped with at least one microcomputer for automa¬ tic regulation of the amount of particles thrown out depending on the oil flow from the magnetic collecting device, that is to say the microcomputer adjusts the amount and possibly the kind of particles thrown out so that an optimum flux^' is obtained from the magnetic col¬ lecting device.

Connected to the microcomputer there may also be a detecting device recording the viscosity of the oil (for selection of the kind of particle and to determine the amount of particles thrown out per unit of time). The viscosity detecting device can be directed down into the water during the displacement of the craft.

Apart from the viscosity detecting device, a device detecting the thickness of the layer of oil can also be connected to the computer, through which the speed and direction of the craft can be regulated automatically during its displacement over the bed. The computer can also control the magnetic collecting device and any separator which may be present so as to achieve an op- timum oil flow into the craft. A recording device detect¬ ing the amount of particles in the oil flow from the separator can be connected to the computer to control the particle feeder and/or to regulate the separator effect. If necessary, the flow of oil from the separator can be returned to the separator or to another separator to achieve an effective separation of magnetic particles from the oil .

The particle feeder may consist of a series of separate nozzles situated at the front end of the device - seen in its direction of travel - and which can be adapted only to permit the feed of magnetic particles when the distance from the bed is below a predetermined length. This is of particular importance when the device is used on land for collecting oil, which prevents par- tides from being discharged from the nozzles which are over deep holes and crevices. That is to say when the risk is too great that the magnetic field of the oil-col¬ lecting magnet device will not be able to attract the particles mixed with oil . The magnetic particles can be fed out directly into the supporting stream of air under a hovercraft or can be fed into separate air-flow passages through conduits leading into these by means of ejector action.

The invention will now be described with reference to examples of embodiment shown in which FIG 1 is a diagrammatic side view of a device illustrating the method of working of the invention over the surface of land or water; FIG 2 is a view similar to that in FIG 1 , but where the oil collection takes place under the surface of the water;

FIG 3 is a diagrammatic side view of an oil -collect¬ ing device situated on a conventional vessel ; FIG 4 is a diagrammatic side view showing a con¬ tinuous re-use of the magnetic particles when col¬ lecting oil ;

FIG 5 is a diagrammatic front view of a wrecked vessel , round which are connected collecting devices according to the invention;

FIG 6 is a diagrammatic side view illustrating an embodiment of the magnetic oil -coll ecting device, which can also be used under water; FIG 7 is a diagrammatic side view of another embodi¬ ment of the magnetic collecting device intended to work just above the surface of the land or water; FIG 8 is a section through a separator to illustrate the method of working of the separator when separat¬ ing magnetic particles from collected oil ; FIG 9 is a diagrammatic side view, partly in section, of a hovercraft provided with equipment for oil col¬ lection in accordance with the principles of the present invention;

FIG 10 is a diagrammatic side view, partly in section, of a smaller hovercraft, possibly radio-controlled or manually operated, and provided with oil-collect¬ ing equipment; and

FIG 11 is a block diagram illustrating the control of a hovercraft provided with equipment for collect¬ ing oil in accordance with the principles of the pre¬ sent invention. FIG 1 shows a surface 3 contaminated with oil 2. Above the oil 2 there is situated a feeder 5 for dis¬ charging magnetic particles 1 in the direction of the oil. The magnetic particles 1 can be blown of thrown in the direction of the oil at high speed and penetrate into the oil or possibly mix with an oil scum which has formed. A magnetic field generated by the magnet device 4 attracts the magnetic particles 1 mixed with oil , which are conveyed in the direction of the magnets and on to the collecting container,

FIG 2 illustrates the method of operation of the invention below the surface 3 of water, in which case the magnetic particles 1 are considerably heavier in comparison with the particles shown in FIG 1, and may be conveyed towards the oil 2 by means of a water jet from the feeder 5. Depending on the temperature of the water and the consistency of the oil , oil residues bro¬ ken loose and provided with particles are attracted by the magnet devices 4. FIG 3 shows how the magnetic particles 1 are thrown out towards floating oil 2 via feeders 5, after which the oil 2¹ mixed with particles is attracted by a magnet device 6 connected to a conventional vessel 7 which is moving in the direction of the arrow A. The magnet device 6 consists in this case of a disc or a tongue, possibly plough-shaped, in which stationary magnet members 4* are disposed along the whole length of the disc or tongue. The magnet members 4' are adapted to generate a magnetic field which travels continuously upwards and which at- tracts the particles 1 mixed with oil and causes these to be conveyed up to the vessel 7. The disc or tongue may appropriately be bent in the vessel 7, which means that the oil falls down into a collecting vessel or the like by the action of gravity. According to the present invention, it is also pro-

Θ posed that the magnetic particles should be separated from the collected oil and re-used.

FIG 4 shows diagrammatical ly this collection of oil mixed with magnetic particles and where the magnetic particles are separated and re-used. 1 designates the magnetic particles and 2 designates the oil which is to be collected. The magnetic particles mixed with oil are attracted by a magnetic field generated by the magnet device a, from which the particles are transferred to the oil collecting device b for further conveying to a separator c. From the separator c, the oil cleansed of magnetic particles 1 is conveyed to a container e. The magnetic particles 1 recovered are returned through the conduit f to the feeder 5. FIG 5 shows a vessel 8 which is leaking oil at the side of which there are anchored magnet devices and/or oil collectors 4 connected thereto. The oil 2 leading from the vessel 8 is mixed with such a large amount of magnetic particles 1 that the oil mixed with particles can be kept round the vessel. Oil -collecting devices connected to the magnet devices holding the oil in posi¬ tion can then be used to collect the oil which has leaked out. The magnet devices 4 can be placed so tightly round the vessel 8 that the magnetic particles in the oil cannot escape being attracted by the magnetic field of one of the magnet devices 4.

FIG 6 illustrates the working principle of a kind of separator 9 which can be used for separating the oil from the magnetic particles mixed with oil which have been collected.

The separator 9 is of the centrifugal type and con¬ sists of a conical vessel 11 of a material which trans¬ mits a magnetic flux, for example a ceramic material . The vessel 11 is rotated about a central axis 10 while oil and particles are fed into the vessel . Through suitable selection of the speed of rotation and the conicity of the vessel, the lighter oil can be caused to flow out over the edge of the vessel , which is illustrated by arrows 12, and the heavier magnetic particles, on which the force of gravity exerts a greater downwardly directed force than the centrifugal force which is acting on the particles, are conveyed downwards and leave through an opening in the bottom of the vessel 11, which is indi¬ cated by arrows 13. The discharged magnetic particles are transferred to a conveyor belt 14 by attraction from a stationary magnet 15 and are conveyed for re-use.

The separating effect in the separator 9 shown in FIG 6 can be further increased by the provision of sta¬ tionary magnet members placed round the periphery of the vessel 11, which is indicated at A. These magnet members can generate a magnetic flux which travels con¬ tinuously downwards and which "force conveys" the mag¬ netic particles downwards along the inner periphery of the vessel 11, in the direction of the conveyor belt 14. FIG 7 shows an embodiment of a collecting device for magnetic particles mixed with oil, which differs from the device 6 shown in FIG 1 in that a movable con¬ veyor belt 16, for example of plastics or rubber, is used to convey the oil 2 upwards. A stationary magnet 17 is placed behind the conveyor belt 16 to which the oil is attracted and conveyed for delivery to a vessel 18. This oil -collecting device can be used under water, like that shown in FIG 3.

FIG 8 shows an oil -collecting device, preferably intended for use over the surface 3 of land or water. This collecting device has several similarities to the separator shown in FIG 6 and comprises a cone 20, open downwards, of a material which transmits a magnetic flux and which is adapted to rotate round a central axis. The magnetic flux from magnets 19 disposed stationarily at- tracts the oil 2 mixed with particles and lifts it into the cone 20, and the centrifugal force conveys the col¬ lected oil downwards and out through peripheral outlets 21 disposed at the bottom of the cone 20. The oil -collecting device shown in FIG 8 can also, like the separator shown in FIG 6, be provided with stationary magnet members generating a magnetic flux travelling continuously upwards, which means that the collecting device does not need to rotate. A suction pipe is disposed centrally in the upper portion of the cone-shaped part 20 to convey collected oil further. This modification of the collecting device can also be used to advantage under water.

FIG 9 shows a hovercraft 2 intended to pick up oil in accordance with the principles of the present inven¬ tion. The hovercraft, which can travel quickly over large areas of water, is not hampered by obstacles in the water in the form of rocks, small islands etc, and can be used for the total clearing of oil discharge, that is to say the craft can also be driven up on contaminated beaches. Hovercraft are well suited for picking up certain kinds of oil , since the air-cushion supporting the craft also foams up oil, possibly mixed with water, while at the same time the magnetic particles in the form of a fine powder are fed into the supporting stream of air, and produce a "magnetic oil scum" which can easily be col¬ lected by the magnet devices placed round the lower pe¬ ripheral edge of the hovercraft. Apart from the oil-col¬ lecting equipment, the hovercraft shown in FIG 9 is of conventional type, where the magnetic particles 1 are discharged into the supporting stream of air and thrown in the direction of the oil 2, the particles mixed with oil being attracted by the magnet devices 23 placed pe¬ ripherally on the craft. Picking up oil in accordance with the principles of the invention can also be effected by means of smaller wheel-borne devices or smaller air-cushion craft, of which one is shown diagrammatically in FIG 10. Even if this smaller craft can be provided with tanks for the collected oil , it is generally practical to connect the craft to a suction line 24 for the collected oil and possibly to a conduit 25 for feeding the magnetic par¬ ticles to the craft. The craft can be equipped with an operating handle 27 or can be remote-controlled by wire or radio.

FIG 11 shows a block diagram of a regulating and control equipment for controlling a fully equipped hover¬ craft for example, that is to say a craft in which the magnetic particles are separated and re-used and where the collected oil is stored in tanks in the craft.

The central control unit 30 preferably comprises a computer which can be programmed and which can regulate all the functions of the craft.

Data from a device 31 recording the presence of oil and possibly the thickness of this is fed to the central control unit 30. Another device 32 feeds data concerning the viscosity of the oil to the central control unit 30 which acts on the feeder 33 via the device 34 for the selection of a suitable kind of particle, for discharging magnetic particles towards the oil. The effectiveness of the magnetic collector 35 is recorded continuously by the unit 30 which may also include a stationary magnet member generating a continuously travelling magnetic flux, constantly acted upon with regard to the strength and speed of travel of the magnetic flux to achieve a maximum entraining effect on the magnetic particles mixed with oil. Likewise, the device 36 records the oil flow to or from the separator A, and possibly the presence of particles in the oil flow from the separator through the device 37. 38 records the level in the collecting tanks

^' β υ ^t< f ?. in the craft. Finally there are devices 39 and 40, the purpose of which is to regulate the speed and direction of travel of the craft, via the central control unit 30. These devices are so coupled to the central control unit that when the device 31 records oil , the craft is braked and remains in place until the device 31 no longer records oil in this place, after which the craft is displaced slowly forwards or sideways until the device 31 again records the presence of oil on the bed. A "search program" can also be connected to the central control unit 30, which guides the craft over a predetermined area to search for oil , the search program being "frozen" and disconnected as soon as the presence of oil is recorded by the device 31. Depending on lee- way in the craft caused by wind or currents, informa¬ tion from navigation aids, such as radio beacons or the like, can also be conveyed to the.-central control unit. The invention is not restricted to the examples of embodiment shown, but modifications can be made within the scope of the patent claims given hereafter.

Claims

1. A method of collecting oil or the like, c h a r a c t e r i z e d in that magnetic particles are brought into contact with the oil , that the oil is then collected by the magnetic particles mixed with oil being attracted by a magnetic field generated by a mag¬ net device.

2. A method according to claim ^ c h r a c ¬ t e z e d in that the magnetic particles are thrown towards the oil at high speed.

3. A method according to claim 1 or 2, c h a r a c- t e r i z e d in that the magnetic particles mixed with oil and accumulated against the magnet device are con¬ veyed to a separator for the separation of oil from particles.

4. A method according to claim ^ c h a r a c ¬ t e r i z e d in that the magnetic particles are heated before being brought into contact with the oil.

5. A device for collecting oil or the like and for carrying out the method according to claim ^ c h a ¬ r a c t e r i z e d by a feeder (5) for feeding mag¬ netic particles (1) to the oil (2) and by a magnet de¬ vice (4; 6; 23) for collecting the magnetic particles

( 1 ) mixed with oil .

6. A device according to claim 5, c h a r a c ¬ t e r !^" z e d by a separator (9) for separating oil from the magnetic particles (1) collected.

7. A device according to claim 5 or 6, c h a r a c- t e r i z e d in that at least the magnet device (4; 6; 23) for collecting the magnetic particles mixed with oil is adapted to be sunk below the surface (3) of water.

8. A device according to claim 6, c h a r a c ¬ t e r i z e d in that the feeder (5) for feeding magne¬ tic particles, that the magnet device (4; 6; 23) generat- ing a magnetic flux for collecting the magnetic particles mixed with oil and that the separator (9) are all dis¬ posed on a hovercraft (22).

9. A device according to one or more of the claims 5 - 8, c h a r a c t e i z e d in that the operation of the feeder (5) for magnetic particles, the operation of the magnet device (4; 6; 23) for collecting magnetic particles mixed with oil, and possibly also the opera¬ tion of the separator (9) for separating oil from the ^• particles, are regulated by a central control unit (30) which at least detects the viscosity and thickness of oil. present, the oil flow to or from the separator and possibly the amount of particles in the oil flow from the separator.

10. A device according to claim 9, c h a r a c - t e r i z e d in that the central control unit (30) also records and regulates the speed and direction of travel of the craft depending, for example, on the thickness of a layer of oil and/or depending on the flow of oil to or from the separator.