Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02B—HYDRAULIC ENGINEERING
  • E02B15/00—Cleaning or keeping clear the surface of open water; Apparatus therefor
  • E02B15/04—Devices for cleaning or keeping clear the surface of open water from oil or like floating materials by separating or removing these materials
  • E02B15/046—Collection of oil using vessels, i.e. boats, barges
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02B—HYDRAULIC ENGINEERING
  • E02B15/00—Cleaning or keeping clear the surface of open water; Apparatus therefor
  • E02B15/04—Devices for cleaning or keeping clear the surface of open water from oil or like floating materials by separating or removing these materials
  • E02B15/10—Devices for removing the material from the surface
  • E02B15/103—Rotary drums
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
  • Y02A20/00—Water conservation; Efficient water supply; Efficient water use
  • Y02A20/20—Controlling water pollution; Waste water treatment
  • Y02A20/204—Keeping clear the surface of open water from oil spills

Definitions

• This invention relates to a vessel for removing patches of oil or other oleaginous substances from the surface of water or aqueous solutions, and has particular, though not exclusive application to the scavenging of large oil patches, which are commonly known as oil slicks, from the surface of the sea Background Art
• large oil patches which are commonly known as oil slicks
• Various methods have been proposed to deal with the serious pollution problems that arise when large quanti ⁇ ties of oil are lost from tankers or other vessels. The oil tends to float in large slicks at or adjacent the surface of the.sea.
• the present invention provides a vessel for removing oil (which herein includes other oleaginous substances) from a patch of oil at or adjacent the surface of a watery medium (which herein includes aqueous solutions and specific examples of which are se or estuary waters) including: a plurality of generally hollow cylindrical structures, each being mounted for rotation about its axis and each bearing at least one continuous oleophili or hydrophilic surface extending cireumferentially abou its axis, each of said structures being disposed for partial immersion in the watery medium so that upon rotation each portion of each oleophilic or hydrophilic surface passes periodically through a surface zone of t watery medium to accrete oil thereto, and the hollows o the cylindrical structures being sealed to provide buoy for the vessel; means for removing accreted oil from the oleophilic or hydrophilic surfaces; and means for collecting the oil thus removed.
• the vessel preferably comprises two such cylindrical structures that have their axes extending longitudinally of the vessel and defining respective sides of the
• the two hollow cylindrical structures are arranged to provide the required buoyancy for the vesse which in this respect may be likened to a twin-hulled catamaran.
• This last-mentioned vessel may be provided with a bow-shaped, apron acting as a bow for the vessel and shaped to direct oil to the outer sides of the cylindrical structures for collection thereby.
• the front of the vessel is provided with diverging vanes or the like aiding in directing the flow of the watery medium to the area between the two cylindrical structures as the vessel moves forward.
• the oil collecting means of the vessel preferably comprises a trough extending between the two cylindrical structures, the oil removal means being arranged to discharge the removed oil into the trough.
• the trough may have a sloping bottom with a chamber at ' •: the deeper end of the trough having an inlet from the lower part of the trough to collect water in the chamber, and with a .well at the shallower end of the trough arranged to receive liquid, i.e. primarily oil, spilled over from the shallower end. .
• the trough may additionally carry a keel depending therefrom to stabilize the vessel.
• Pig. 1 shows a plan view of a catamaran kind of vessel embodying the invention having inwardly, rotating cylindrical hulls;
• Fig. 2 shows a transverse section through the vessel of Fig. 1;
• Fig. 3 shows an axial section through the vesse demonstrating a preferred form of collecting trough
• Fig. 4 shows a transverse section through a similar vessel but adapted for outwardly rotating hulls
• Fig. 5 shows a simplified plan view of a catamaran vessel similar to Fig. 1 but having a modified bow section.
• the vessel 10 comprises two longitudinally-extending parallel hulls each comprised of a sealed, hollow cylindrical shell 12 and 14 closed at its ends and having projecting axial shafts 16 about which each shell is rotated.
• the shafts are mounted for rotation in transverse rigidly connected frames 18 and 20 which togethe with the shells form the essential buoyant structure of the vessel.
• the shells float partly immersed in the sea 1.
• the rear frame 20 of the vessel carries a prope
• the vessel 22 driven by an engine (not shown) and also carries a pa of rudders 24.
• the vessel is thus driven in the directi indicated by arrow 26.
• the front frame 18 may carry a pair of forwardly and divergingly projecting vanes or booms 28 having their inward ends secured in line with t respective cylindrical shells, to aid in directing the floating oil into the area between the hulls 12 and 14 a indicated by arrows 30 as the vessel moves forward. Suc an arrangement is applicable in cases where the oil is t be scavenged from the area between the hulls.
• the vanes 28 lie in the surface zone of the sea.
• the inward oil deflection provided by the vanes 28 is appropriate to the case where the cylindrical shells are rotated inwardly as seen in plan view, i.e. they rise out of the sea at their outer surfaces as seen in Fig. 2."
• the shells are rotated in opposite directions by means 32 coupled to the shafts 16 and driven by the main or an auxiliary engine.
• the shells have an oleo ⁇ philic surface.
• the shells may be of metal and carry an oleophilic plastics coating such as poly- ethylene or polypropylene.
• tests have indicated that a plain slightly rusty steel surface is sufficiently oleophilic.
• the shells illustrated have plain cylin ⁇ drical surfaces and a sufficient rate of accretion onto these surfaces has been achieved with light oils about which more is said below.
• the surface could be provided with projections such as rib ' s or teeth.
• the oil from the patch 2 between the shells accretes on the cylindrical surfaces as they enter the surface zone and is carried under the shells, being maintained there by hydrostatic pressure, then carried upwardly and inwardly for removal from the surfaces.
• the accreted oil is removed and discharged into a centrally-mounted trough 34.
• the trough is carried by longitudinal supports (not shown) mounted to the transverse .frames 18 and 20.
• the trough 34 is generally V-shaped and its edges are formed as or are fitted with doctor blades 36 and 38 extending along the upper and inner surfaces of the shells 18 and 20 respectively to scrape the accreted oil off the shells and direct it into the trough.
• Figs. 1 and 2 illustrate a trough of uniform cross-section in the rear end of which a pump 40 is mounted to pump the collected oil to some larger vessel through a pipe-line 42.
• the trough 34 may also serve to support a keel to stabilize the vessel as is shown in Fig. 4..
• FIG. 3 is a longitudinal, axial cross-section through th vessel fitted with the modified trough.
• the trough 50 provided with doctor blades, as before, is shaped to have a sloping bottom 52 that is deeper at the forward end of the vessel than aft.
• t shallow end of the trough leads to a well 54 in which i located the pump 40 for discharging the oil.
• the trough has a chamber 56 having an aperture 56 communi-cating with the lower part of the tr
• the chamber 56 also has an upper vent 59 together with depending outlet pipe 60. the upper end of which project into the chamber and which leads downwardly into the se for a sufficient distance to be below the level of the oil patch being scavenged.
• the modified trough serves to. separate the lig oil 3 from water 4. Quantities of water may enter the trough by being shipped over the sides, i.e. over the h or enter as spray in rough weather. It is desirable to separate and discharge such substantial amounts of wate before pumping from the trough.
• the upper end of t pipe should thus be sufficiently high to provide an adequate working head of the oil floating on the water the trough.
• the lighter oil spills over the shallow en of the trough into well 54 and is pumped out.
• the trou is provided with perforate lateral walls or baffles 62 impede large-scale motions of the liquid in the trough the event of heavy pitches of the vessel.
• FIG. 4 there is shown a transver cross-section in which the cylindrical shells 12 and 14 are rotated outwardly as seen in plan view, i.e. they enter the water at their outer surfaces.
• the oil could be
• each shell 12 and 14 leading to a well at the rear of the vessel but preferably it is collected as shown in an axially-extending trough 70 between the hulls which is shown as carrying a keel 72 to stabilize the vessel.
• the oil here is mainly collected from the surface zones outside the hulls and to remove it from rotating surfaces the framework supports two reflexed doctor blades 74 acting on the upper, inner surfaces of respective ones of the hulls.
• the reflexed doctor blades and rollers remove oil from the cylindrical surfaces and guide it for discharge into the t ough.
• the trough is provided with a pair of doctor blades 80 engaging rollers 76 to discharge oil clinging thereto into the trough.
• a roof section 82 extends between the reflexed doctor blades 74 to form therewith a complete roofing structure for the trough. This is of benefit in reducing the amount of water that is able to enter the trough. Consequently the oil/water separation measures proposed wLth reference to Fig. 3 may not be necessary.
• vanes 28 of Fig. 1 can be replaced by, for example, a detachable, shaped bow piece such as shown in Fig. 5.
• the vessel 90 in .Fig. 5 is similar to the vessel 10 of Fig. 1 and has the same support structure or frame ⁇ work (not shown for simplicity in Fig. 5) in which is rotatably supported two cylindrical shells 92 and 94 whose construction is similar to that of shells 12 and 14 of vessel 10 and thus will not be further described.
• Fig. 5 shows one major difference which lies in a bow structure 96 cooperating with the shells to guide oil to the outer sides of the vessel as it moves forward in the direction of arrow 98.
• the forward and rear end portions of the cylindrical structures are streamlined to assist motion through the water.
• the bow structure 96 for the vessel is in the 0 form of a bow-shaped apron.100 which is secured to the forward framework that supports the shells, i.e. the transverse structure 18 in Fig. 1 of the apron 98 > terminates in respective rearward portions 102 that longitudinally overlap the forward end portions of the 5 cylindrical structures 92 and 94 and are recurved so as to aid in directing oil onto the cylindrical side ⁇ - " sur aces as. the vessel moves forward as indicated by arrows 104.
• the cylindrical structures are coupled to means such as illustrated in Fig. 1 for driving the 0 structure in opposite directions with each portion of t continuous oleophilic surfaces periodically entering th surface zone of water on the outer sides of the vessel.
• the collecting trough arrangement can correspondin be changed to a form such as shown in Fig. 2.
• a twin-hull vessel of the kind described above may have the cylindrical shells of say 20 metres in 5 length and 3.5 metres in diameter.
• the accretion of oil to the cylindrical shell surface is achieved by use of oleophilic surfaces. It is found that when using oleophilic surfaces the accretion of the oil thereto takes place at the point where the moving surface enters the surface zone. It is, however possible to reverse this situation by using a hydrophilic surface, the accretion occurring as the surface leaves the surface zone.
• Hydrophilic surfaces which are wetted by water or aqueous solutions in preference to oil or other oleaginous substances are not readily realised but such a surface may be provided by means of covering the cylindrical surfaces of the hulls with natural fibres such as cotton in the form of a woven cloth; such a surface needs to be first wetted with water before being employed to scavenge oil.
• the technique may be of value with highly aqueous emulsions.
• the catamaran kind of vessel described is a purpose-designed craft for scavenging oil slicks. It combines into one structure, the oil accretion means and the hull of the vessel.
• the vessel has particular ability, in large bodies of water, such as the open sea, for disposing of large oil slicks through which the vessel can be driven in successive sweeps.
• the smooth shelled structuresdescribed aid propulsion and simplify the doctor blade arrangement required to remove the accreted oil. These structures are felt to be particularly suitable for lighter oils and while no absolute upper bound can be given, oils up to a viscosity of 2 0 SAE are particularly mentioned.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Environmental & Geological Engineering (AREA)
• Mechanical Engineering (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Removal Of Floating Material (AREA)
• Cleaning Or Clearing Of The Surface Of Open Water (AREA)
• Treatment Of Liquids With Adsorbents In General (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)

Applications Claiming Priority (4)

Publications (1)

Family

ID=26268125

Family Applications (1)

Country Status (4)

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Family Cites Families (6)

• 1979
  • 1979-07-02 NO NO792211A patent/NO792211L/no unknown
  • 1979-07-05 WO PCT/GB1979/000114 patent/WO1980000161A1/en unknown
  • 1979-07-05 IT IT24126/79A patent/IT1166895B/it active
• 1980
  • 1980-02-12 EP EP79900710A patent/EP0016065A1/en not_active Withdrawn

Non-Patent Citations (1)

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