CA2081889C

CA2081889C - Self-cleaning vacuum head for recovering oil from beaches and the like

Info

Publication number: CA2081889C
Application number: CA002081889A
Authority: CA
Inventors: Allen Charles Francisco, Jr.
Original assignee: Ecosphere Guardian Systems Inc
Current assignee: Ecosphere Guardian Systems Inc
Priority date: 1990-05-04
Filing date: 1991-05-06
Publication date: 1998-06-09
Anticipated expiration: 2011-05-06
Also published as: DE69115508D1; DE69115508T2; GR3018536T3; WO1991017319A1; DK0597841T3; EP0597841A1; EP0597841B1; ES2085475T3; US5076919A; AU7869591A; ATE131561T1; CA2081889A1

Description

W~ 91/17319 2 ~ $ ~ P~/US91/03107 t)escri~tion SELF--CLEANING VACUUM HE~D FOR RECOVERING OIL
FROM B~AC~IES AND THE LIKE
Technical Field The invention is related to apparatus and techniques for ren~ovirlg con~ i n~nts, including fluid from particulate matter. More speciPically, tha invention is related to apparatus and techniques for recovering oil or other hazardous materials from beaches and the like.

Backaround o~ the Invention Large quantities o~ oil are presently transported ~rom oil producing nations to oil-consuming nations by various means, including large sea-going vessels. As the nu~ber and si~e of such vessels increa~es, the proba~ility of a large oil spill occurring, with its att~ndant, serious environmental consequences also increases. A number of such accidents have occurred which have resulted in contamination of beaches with possibly permanent environmental damage.
Substantial progress has been made in the recovery of oil ~pilled on large bodies of water.
Typically, the oil spill is ~u~unded by a ~loating boom to contain the spill. Conventional va~ inq and filtering equipment are then e~ployed to remove the oil from the circumscribed area, as the oil will continue to ~loat an the surface of the water as long as the ~ore volatile components of the oil have not evaporated. Such e~orts have proven e~fec~ive as long as the oil remalns at sea, the booms are quickly deployed, and the sea is not too rough.
~ecovering oil from beaches i5 substantially more di~icult than recovering oil ~rom the sea. The beach environment contains a large number of organisms which live on the beach, and below the surface of the -: , , ".
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W O 91/17319 2 ~ P~r/US91/03107 beach up ~o a depth of approximately one foot In contrast, the upper layer of the ocean is a relatively "dead" ecological environment. Therefore, oil spills which have washed up on beaches generally cause significantly greater ecological damage than oil spills which are contained at sea.
Unfortunately, no currently known technologies have been succ~ssful in recovering oil directly from beaches in an ecologically acceptable ~anner. Presently, the most effective method of cleaning oil cont~ ted beaches is to wash the spilled oil bac~ into the ocean so that the boom and vacuum method described above can be employ~d. This technique is only successful if the oil spill is fresh (i~ the volatiles have not evaporated).
If the oil has begun to evaporate, the beach deposit hoc ~~c a heavy sludge which can only be washed off with stea~ or extremely hot water at hi~h pressure. This combination destroys the beach and is injurious to the organisms which 1 ive on and under the beach.
Once substantial evaporation of the oil has occurred, the only current t~chniques which are at all succ~cs~ul in removing the oil involve removing the top layer of sand or gravel fro~ the bea~h with shovels, treating the sama and redepositing the sand/gravel back onto the beach. This proces~ completely destroys the ecological activity in the most ecologically active layer o~ the beach~ and is also an extremely expensive procedure. In addition, this technique is slow, allowing large c~; ents of contaminated beaches to exist for some time. As a result thereo~, water fowl, turtles, and other marine animals, etc., which inhabit the beach/ocean interface he,-_ ~ contaminated.
Various prior art devices have been described for treating contaminated beaches. The A ~ hihious ~ehicle disclosed in U.S. Patent No. 4,769,142, to Withnal, is propelled on the surface of the beach by large rollers which support an oil-absor~ent sponge on the perimeter 2 ~ PCT/US91/03107 thereof. As the rollers move along the surface of the beach, the sp~nge absorbs the oil. The oil is removed from the sponge by pinch rollers~ The roller sponge described by Withnal would only be ef~ecti~e at removing oil from the surface of the beach if the oil had not begun to evaporate. Further~ore, this device do~s nothing to treat the first ~oot or so of material under the beach surface which contains substantial numbers of living org~ n i ~ c .
In another design disclosed in U.S. Patent No.
4,492,00l, to Hedrenious, absorbent material i5 discharged throuyh a duct onto t~e beach. The oil is absorbed by the sorbent material for later withdrawal ~rom the surface such as by a vacuum. The Hedrenious device would also only be effective during the early stages of a beach cont~ tion be~ore the oil had begun to evaporate. In addition, this device would also fail to treat any p~rtion of the beach below the ; -~;ate top sur~ace thereof.
In addressing the problem of treating the entire vertical depth of the beach which may be contaminated, Wendt et al. disclose a cryogenic beach-cleAning device in U.S. Patent No. 4,157,016 which freezes the upper layer of the beach with a cryogenic fluid such as li~uid nitrogen.
A trackor-like device drives a shovel which scoops up and 2S breaks up the frozen beach surface for later reprocessing.
~his tP~hni qu2 would certainly destroy all of the org~ni: ~ in the treated layer and suffers from the processing costs which are presently encountered by the ~nual shoveling technique.
In view o~ the above, a need exists for a device which can ef~ectively remove oil deposi~ed on a beach, whether the oil has begun to evaporate or not, without substantially disturbing the physical structure of the beach or killing the org~ni~C which reside thereunder.

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WO91/17319 2 0 81 (~ 8 ~ PCT/US91/03107 summary of the Invention It is an object of ~he present invention to provide an apparatus which can separate a fluid such as oil from a particulate medium, such as a beach, without substantially disturbing the structure of the madium.
It is also an object of the invention to achieve the above object if the fluid has evaporated to a heavy sludge state.
It is yet another object of the invention to achieve the above twe objects while minimi2ing the ecological impact on organis~s residing in the medium.
The above objects, and other objects and advantages o~ the invention which will become apparent fro~ the descr ption which follows, are achieved by pro~iding a media treatment device and terh~ique which removes viscous fluid from particulate matter without substantially disturbing the structure of the particulate medium.
In its preferred embodiment, the invention includes two surfaces which ~ove with respect to one another. One of the surfaces has an elongated slot. The other surface has an elongated area of perforation which is positioned transverse to the elongated slot. The surfaces are ~oved with respect to one another such that the slot and area of perforation are at least partially coincident some of the ti~e, and wherein at some other time the slot and area o~ per~oration are not coincident, The dimensions o the slot and area of perforation are selected such that when the two are coincident, they define an intersection having a ~i dimension which is smaller than the smallest cross-sectional dimension of the particular ~atter which is expected to be encountered. A vacuum is drawn across the two sur~aces such that a fluid, for example, oil, and a particle such as a pebble from a beach are both drawn to the intersection. As the two surfaces move, the pebble tends to roll in the intersection while the oil is drawn -'~ . ' . ' ' '' ' ,' . - ' ,~ . ' ' .. .. ,~ : . .. , ~ . .

WO91/17319 2 ~ u'.~ PCT/US91/03107 therethrough by the vacuum. The remov~d oil is stored in a container. When the elonqated slot and elongated area of perforation are no longer coincident so as to form the intersection, the vacuum against the pebble is lost and the pe~ble drops back down onto the beach. In this manner, the beach becomes completely cleaned but the structure of the beach is not substantially altered.
The device may also be provided with a steam generator which directs a spray of steam or heated water forwardly of the de~ice to liquify an oil deposit which has evaporated into a heavy sludge so as to improve the e~ficacy of the device. The steam or warm water spray may be directed to penetrate below the ~each surface to loosen oil deposits for removal by the vacuum. The temperature of the water or steam may be regulated accordingly to preserve the org~n; r q which reside on or under the beach.
In addition, the device can be mounted on a vehicle which suspends the device above the beach and which moves the de~ice over the surface o~ the beach.
Brief DescriDtion of the Drawinqs Figure 1 is a s~h~ ~tic representation of an oil recovery system employing the device of the present invention.
25Figure 2 i a side elevational Yiew of a self-cl~; ng vacuum head employing the pre~ent invention.
Figure 3 is a ~ottom plan view of the vacuum head of Figure 2 shown with a flexible belt removed.
Figure 4 is a partial, exploded, iso~etric view of a vacuum plenum and rotating belt employed in one embo~i ~nt of th~ present invention.
Figure 5 is an enlarged, sectional bottom view illustrati~g the physical orientation of relatively moving first and second surfaces of the invention.
35Figures 5a-5c are schematic representations of the operation of one embodiment of the invention.

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Figure 6 is an alternate embodiment illustrating a second possible orientation of first and sec2nd surfaces o~ the invention.
Fiqure 7 is another alternate embodiment of the first and second surfaces.
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Be~t Mode for Carr~in~ out the Invention An cil spill clean-up syste~, in accoxdance with the principles of the invention, is generally indicated at re~erence numeral lO in Figure l. The s~stem includes a v~hicle 12 which propels and supports a self-cleaning vacuum head 14 and ~orwardly mounted steam jet mani~old 16 above a surface 17 (such as a beach).
The vehicle 12 also has a steam generation system 18 which powers the steam jet manifold 16, and a vacuum generation system 20 which draws oil or other hazardous waste collect~d by the sel~-cleaning vacuum head 14 through a conduit 22. The height o~ the vacuum head 14 and the steam jet manifold 16 above the sur~ace 17 are controlled from a cab section 24 of the vehicle by way of double-acting, hydraulic rams 26. The vehicle also has an engine 28 which drives a conventional hydraulic system (not shown) for operating the hydraulic ra~s and far operating continuous tracks 30 which propel the vehicle.
Other means such as high-floatation ~heels may be used to support and propel the vehicle. The self-cleaning ~acuum head 14 preferably has a width which is at least as wide as the path traversed by the tracks 30.
The system l0 described abo~e and shown in Figure 1 is well adapted for rapid deployment to remote areas for recovery of oil or other hazardous materials which have been deposited on beaches. As is described further hereinbelow, the salf~cleaning vacuum head 14 thoroughly removes oil or other undesirable materials from a particulate medium such as the beach 17 without substantially disturbing the physical structures of the medium. The steam qeneration system 18 can be adjusted by :

WO91/17319 2 0 ~ ,L) PCT/US91/03107 the operator of the vehicle 12 to control the pressure and temperature of the steam (or hot water) ejected through the manifold 16. The temperature should be sufficient to liquefy any oil deposits which have become viscous through evaporation while minimizing the destructive impact of the steam (or hot water) on the marine life on and under the surface of the beach 17. The pressure of the steam or water is adjusted so as to penetrate the beach to the deepest level of contamination.
The self-cle~ning vacuum head 14 has the unique ability to thoroughly clean individual particles on the sur~ace of the beach 17 without drawing the particles into the vacuum system 22. The self-cleaning vacuum head then redeposits the particles in relatively close proximity to their original location. Thus, the system does not undesirably alter the oriqinal structure of the beach in any substantial ~nnGr.
A~ be~t seen in Figures 2 through 4, th~ self-cl~ning vacuum head 14 include a cowling 34 (removed ~or clarity in Figures 3 and 4) which supports therein a vacuum plenum 36. The vacuum plenum is ~urrounded by a belt 38. The belt is rotatingly supported around the vacuum plenum on a pair of rollers 40, one of which is driven by a hydraulic motor 44. The vacuum plenum, rollers, hydraulic motor and cowling are all attached to frame members 45. The cowling 34 also has attached th~reto at the lower periphery thereof a slotted skirt 46 ~hich maintains a pressuxe di~ferential between vacuum plenum 36 and beach surface for a purpose which will become more fully apparent.
As best ~een in Figures 4 and S, the rotating belt 38 has therein a plurality of substantially parallel, elongated slots 50 which when supported by contact with a plate 52 on the vacuum plenum 36, form a first surface 54 for comtacting oil or other hazardous material, and/or the particulate matter on the beach 17. The plate 52 also has a plurality of elongated slots 56 (or a series of aligned , : ' ' WO91/17319 2 ~ ~ ~ 8 ~ ~ PCT/U~91/03107 ' apertures or perforations which approxi~ate elongated slots) disposed on the plate 52 so ~s to define a second surface 58 adjacent to the first surface 54.
The elongated slots 56 (or the series of aligned apertures or perforations) are disposed so as to de~ine a series of parallel axes which are transverse to the orientation of the elongated slots 50 in the first surface 54O The vacuum which is generated by the vacuum system 20 is co~municated to ~he vacuum plenum 36 through the eonduit 22. Thus, the locus of vacuum at the plane of contact between the beach 17 and the first sur~ace 54 appears at intersections 60 of the elongated slots 50 of the first surface 54 with the elongated slots 56 of the second surface 58. This locus of vacuum is constantly 15 changing as the belt 38 rotates on the rollers 40 around the vacuum plenum 36.
The dimensions of the slots 50 and 56 are selectad such that the maximum dimension of the intersections 60 is less than the ; ni cross-sectional ~ cion of particular matter expected to be encountered on the beach. Thus, individual particles are not drawn up into the vacuum plenum 36.
The self-cleaning ~eature of the vacuum head 14 is achieved by providing the elongated slots 50 with a predet~rmined length so that particles drawn up against the intersections 60 will be dropped therefrom when tha slots 50, 56 move into a non-intersecting position as best illustrated in the se~uence o~ Figures 5a th~ough 5c. As shown in schematic representation 5a, a particle 62 is drawn against the intersection of elongated 510ts 50 and 56 by th~ vacuum generated by the vacuum system 20. As the belt 38 moves to the left against the fixed plate 52, the particle 62 will move to a position shown in Figure 5b, and ultimately into a position as shown in Figure Sc 3S wherein the slots 50 and 56 are no longer coincident due to the ter~ination o~ the 510t 50, the transverse relationship between the slots 50 and 56 and the relative :: ' , . ':
... : . . : , . . -W091/17319 ~ PCT~USgl/03107 movement of the first and second surfaces S4, 58. Once the intersection of the slots 50 and 56 is lost, the particle 62 will drop back to the surface of the beach at a location relatively close to its original location.
The transverse orientation of the slots also achieves the surprising result of causing the particle 62 to roll within the intersection 60 along two substantially perpendicular axes, thus pro~oting full and complete separation of cont~ nts (such as oil) from the surface of the particle. A preferred transverse angle ~or the slots is approximately 60 degrees, as sho~n in Figure 5, although relative angles of up to 90 degrees, as shown in Figure 6, are ef~ective, particularly i~ the direction of relative movement of the first and second surfaces is lS transverse to the orientation of either of the slots. In addition, the ~lots 50 of the first surface 54 are preferably of varying length so that the vacuum is cut off at different times at various locations.
A preferred arrangement o~ the first and second surfaces is to have the ~irst surface 54, which will be in contact with the particulate medium as the moving surface.
However, as shown in an alternate ~- ho~i ~nt of the invention illustrated in Figure 7, the~ ~irst surface 64 can be fixed with respect to the cowling 34 of Figure 2, while the second surface 66 moves with respect to the cowling 34 and thus with respect to the first surface 64.
As al5Q shown in Figure 7, the e}ongated slots of the first surface may take the form o~ a single, spiral slot 68 of predetermined length while the second surface 66 has therein a plurality o~ radial slots 70 on a disk 71 which are rotated about an axis in the direction of arrow 72. A
particle trapped at the interseCtion of the spiral slot 68 and one of the .radial slots 70 will move along the path of the spiral slot 68 until the terminus 72 thereof is encountered. At this position, the particle will fall bac3c onto the beach after having been thoroughly cleaned before its redepositioh to the beach surface.

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WO91~17319 ~CT~S91/~3~7 Although the invention described above has been shown in the application o~ recovering oil spills from beaches, the self-cleaning vacuum head 14 has a variety of applications which will be readily apparent to a person of ordinary sXill in the art. Some of these applications include sorting two or more materials having substantially different ~i -n~ions. An important teaching to be followed in the practice o~ any such device is to maintain the m~Yi di -~cion of the intersection of the slots (or slot and elongated area o~ perforation) so as to be larger than the maximum anticipated cross-sectional dimension of one of the objects, and smaller than the ~Yi _ expected cross-sectional ~ ion of the rPr~;ning object or objects. The smaller of the two objects will be drawn into the vacuum plenum 36 while the larger objects will be le~t behind. There~ore, the i~ention is not to be limited ~o the applications or specific structures disclosed above but is to be detenmined in scope by the claims which follow.

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Claims

WHAT IS CLAIMED IS:

1. A media treatment device for removing fluid from particular matter including, a first surface for contacting the particulate matter, a second surface adjacent to the first surface, the second surface having an elongated area of perforation, moving means for moving the first and second surfaces, and vacuum means for establishing a pressure differential across the first and second surfaces, characterized in that:
the first surface has an elongated slot of predetermined length defining a slot axis and the elongated area of perforation in the second surface defining a perforation axis transverse to the slot axis, and wherein the first and second surfaces move with respect to one another from a first relative position to a second relative position, wherein at the first position the slot and the area of perforation are at least partially coincident, and wherein at the second position the slot and the area of perforation are not coincident so that the particulate matter is drawn against an intersection between the slot and the area of perforation while the same are coincident to remove the fluid from the particulate matter and so that the particulate matter is released from the first surface when the slot and the area of perforation are not coincident.

2. The device of claim 1 wherein the elongated area of perforation is also a slot.

3. The device of claim 1 wherein the elongated slot in the first surface is substantially spiral,and wherein the elongated area of perforation in the second surface is a slot directed substantially radially with respect to the spiral.

4. The device of claim 1 wherein the second surface is positioned between the first surface and the vacuum means.

5. The device of claim 4 wherein the second surface is fixed with respect to the vacuum means and wherein the first surface moves with respect to the vacuum means.

6. The device of claim 5 wherein the vacuum means includes a vacuum plenum, wherein the second surface is a plate attached to the vacuum plenum, and wherein the first surface is a flexible, endless belt surrounding the vacuum plenum and rotatively driven thereabout.

7. The device of claim 4 wherein the first surface is fixed with respect to the vacuum means and wherein the second surface moves with respect to the vacuum plenum.

8. The device of claim 7 wherein the vacuum means includes a vacuum plenum, wherein the first surface is a plate attached to the vacuum plenum, and wherein the second surface is a flexible, endless belt rotatively driven within the vacuum plenum.

9. The device of claim 1 wherein the elongated slot and the elongated area of perforation have a maximum dimension of intersection selected to be smaller than the smallest particulate dimension expected to be encountered in the media whereby particles drawn against the first surface tend to roll in the intersection so as to promote thorough separation of the fluid from the particles until the slot and the area of perforation are no longer coincident.

10. The device of claim 1, including a vehicle for carrying the device in a suspended manner over the media to be treated and steam jets mounted forwardly of the device to decrease the viscosity of the fluid to be removed from the particulate matter.

11. A vacuum pick up device for removing fluid from the particulate matter such as oil from a beach or the like including, a first surface for contacting the particulate matter, a second surface adjacent to the first surface, the second surface having an elongated area of perforation having a predetermined width, moving means for moving the first and second surfaces, and vacuum means for establishing a pressure differential across the first and second surfaces, characterized in that:
the first surface has an elongated slot of predetermined length and width defining a slot axis, an elongated area of perforation and a second surface defining a perforation axis transverse to the slot axis, the first and second surfaces are moved with respect to one another from a first relative position to a second relative position, wherein at the first position the slot and the area of perforation are at least partially coincident so as to form an intersection having a maximum dimension selected to be smaller than the smallest particulate dimension expected to be encountered in the media, and wherein at the second position the slot and the area of perforation are not coincident, whereby particles drawn against the first surface tend to roll in the intersection as the surfaces move with respect to one another so as to promote thorough separation of the fluid from the particles until the slot and the area of perforation are no longer coincident so as to release the particulate matter from the first surface.

12. The device of claim 11 wherein the elongated area of perforation is also a slot.

13. The device of claim 12 wherein the elongated slot in the first surface is substantially spiral, and wherein the elongated area of perforation in the second surface is a slot directed substantially radially with respect to the spiral.

14. The device of claim 11 wherein the second surface is positioned between the first surface and the vacuum means.

15. The device of claim 14 wherein the second surface is fixed with respect to the vacuum means and wherein the first surface moves with respect to the vacuum means.

16. The device of claim 15 wherein the vacuum means includes a vacuum plenum, wherein a second surface is a plate attached to the vacuum plenum, and wherein the first surface is a flexible, endless belt surrounding the vacuum plenum and rotatively driven thereabout.

17. The device of claim 14 wherein the first surface is fixed with respect to the vacuum means and wherein the second surface moves with respect to the vacuum plenum.

18. The device of claim 17 wherein the vacuum means includes a vacuum plenum, wherein the first surface is a plate attached to the vacuum plenum, and wherein the second surface is a flexible, endless belt rotatively driven within the vacuum plenum.

19. The device of claim 11, including a vehicle for carrying the device in a suspended manner over the media to be treated and steam jets mounted forwardly of the device to decrease the viscosity of the fluid to be removed from the particulate matter.