Abstract:
A system for recovering oil spilled on a body of water includes a buoyant containment boom of sufficient length to surround at least a portion of the spilled oil, the boom having a plurality of outer pipe sections, each outer pipe section being longitudinally perforated along one side that may be positioned against the spilled oil, a plurality of spaced-apart support members positioned within the outer pipe, and an inner pipe that is longitudinally perforated along one side, generally coextensive with the outer pipe, and rotatably positioned within said support members so that the perforations in the inner pipe sections may be positioned at a desired height within the outer pipe sections. The system also includes at least first and second suction pumps, the first pump acting to draw a water and oil mixture into the outer pipe, and the second pump acting to draw a mixture having a high percentage of oil into said inner pipe. Water is extracted from the mixture and the oil is stored.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to equipment for removing one layer of liquid floating on top of second layer of liquid, such as an oil or petroleum slick floating on a bodies of water, such as rivers, lakes, harbors, and even the open sea. More particularly, the invention relates to oil spill clean-up equipment which utilizes a floating barrier that is used to both surround the spill, or a portion of it, and remove oil from the spill at the surrounded edges thereof. 
     2. Description of the Prior Art 
     The Industrial Revolution, which began around 1750, created an almost insatiable demand for energy. In 1776, the same year that the American colonists declared independence from Great Britain, a Scottish engineer named James Watt designed an improved steam engine having a separate condenser, thereby eliminating the need to periodically cool the engine&#39;s cylinder. Though first used to drive mine pumps, Watt&#39;s steam engines soon found use in textile factories. From that time until the beginning of the twentieth century, the Industrial Revolution was powered primarily by steam engines fueled with coal. Around 1870, the internal combustion engine was developed. Lighter, more compact and more efficient than the steam engine, the internal combustion engine gradually displaced the steam engine which, in developed countries, had virtually disappeared from industrial use by 1960. Turbine engines came into wide use in the late 1950s as powerplants for both aircraft and electric generators. During World War II, the need for synthetic polymers to replace scarce naturally-occurring polymers such as natural rubber and silk spawned the rapid development of the petrochemical industry. At the beginning of the twenty-first century, the world is continuing to squander its petroleum reserves, from which most liquid fuels and most synthetic polymers are derived. 
     The profligate use of petroleum products is not without costs. There is increasing evidence that the global warming is largely attributable to the combustion of fossil fuels. In addition, the exploitation of petroleum reserves, which first requires exploration and drilling; later requires pumping, transportation, and refining of the crude; and finally requires transportation and marketing of the refined products, exacts its own environmental damage. The most serious environmental damage is almost certainly caused by the leakage of crude petroleum from tanker ships with damaged hulls and from broken pipes on offshore oil wells into the ocean. Super tanker ships capable of transporting several hundred thousand tons of crude petroleum are in widespread use and pose a serious threat to ocean environments. Leakage from broken pipes which transport crude petroleum across ecologically fragile regions on land can also create environmental havoc. 
     As the density of petroleum products is about eighty percent that of water, crude petroleum and petroleum products float on water. In the absence of an emulsifying agent, petroleum products are generally not miscible with water. These physical properties make possible the near complete recovery of petroleum products spilled onto bodies of water if the spill is rapidly contained, storms do not widely disperse the oil slick, and the spill occurs far enough from shore that it is not washed up on beaches before containment is effected. Without question, the more rapidly an oil spill can be contained, the greater the likelihood that the cleanup effort will be effective and environmental damage will be minimized. Thus, the speed with which an oil recovery system can be deployed is at least as important as its effectiveness in skimming the spilled oil from the body of water. 
     Much equipment has been developed for recovering layers of petroleum products floating on water. One such apparatus is disclosed in U.S. Pat. No. 3,221,884 to Jacques Muller. The apparatus includes a pair of parallel buoyant pipes, the first of which has inlets which admit water and oil mixture from an oil spill into the pipe, which conducts the mixture to suction pump on a ship, the second pipe having outlets to discharge water from which oil has been removed. The buoyant pipes are interconnected by a series of spaced-apart spacer bars, which support a third pipe used to provide ballast for the pair of buoyant pipes to that the inlets of the first buoyant pipe are positioned at a level that will admit primarily oil from the oil spill. 
     A floatable collar for confining oil spills is disclosed by U.S. Pat. No. 3,369,664 to Paul C. Dahan. The collar comprises an inflatable tube having a weighted skirt attached thereto below the inflatable tube and bulwark made semirigid by inflatable means located above the inflatable tube. 
     The oil slick confinement apparatus disclosed in U.S. Pat. No. 3,565,254 to John P. Latimer includes a vertically-oriented dam attached to a buoyancy member. A awning member, which extends the length of the dam, includes a floating lower edge which rides lightly on the spill side of the dam. The awning member also includes a air suction pipe which maintains pressure between the dam and awning at less than atmospheric. A floating oil collection pipe beneath the awning, which also extends the length of the dam, has inlets through which oil can be suctioned from the spill and transported to a ship or barge for collection. 
     Another apparatus for gathering a floating layer of oil from a body of water is disclosed by U.S. Pat. No. 3,584,462 to Phillip S. Gadd. An impermeable barrier is suspended within screened enclosure of U-shaped cross section. One embodiment of the apparatus employs a barrier suspended along both edges to form a trough through which oil might be transported to a collection location. 
     Another buoyant oil confinement boom is disclosed by U.S. Pat. No. 3,666,098 to Charles Garland, et al. The boom, which is primarily a floating pipe having perforations to receive oil from a spill, includes a suction pump coupled to one end thereof, and a skirt that is dependingly attached to the pipe so that it extends over the perforations without blocking them. 
     Yet another oil control boom is disclosed by U.S. Pat. No. 4,752,393 to Frank Meyers. This boom has walls which define an elongated hollow flotation chamber. Apertures in the walls of the chamber, admit oil, water, or a mixture of both into the chamber, from whence it is removed by a pump for removal of the oil. 
     An oil containment boom and skimmer is disclosed by U.S. Pat. No. 5,160,432 to Peter Gattuso. A first longitudinally extending tubular member is placed adjacent to the oil spill area. It includes an inner open area and inlets for receiving oil and water. A second longitudinally extending tubular member is placed parallel to the first member. A passageway with a lip connects the members and is placed slightly above sea level for skimming the upper layer of oil. 
     An oil spill containment and recovery system is disclosed by U.S. Pat. No. 5,533,832 to Howard Dugger. The system includes multiple containment float/recovery trough sections for collecting spilled petroleum from the water&#39;s surface. The water and petroleum mixture is transferred from the collection trough by a pump to a separation tank. 
     SUMMARY OF THE INVENTION 
     The present invention provides an oil recovery system that includes a floating containment boom having an adjustable height internal oil skimmer for improved oil skimming efficiency. The boom is preferably of sufficient length to surround the spill, or a least a portion thereof. The boom includes an outer pipe that is longitudinally perforated on one side that is placed against a spill. The outer pipe is equipped with flotation devices, the buoyancy of at least one of which is adjustable. The adjustable buoyancy allows the boom to be floated at an optimum level. The boom also includes an inner pipe that is also longitudinally perforated on a single side, the inner pipe being generally coextensive with the outer pipe and rotatably positioned in support members within the outer pipe. Both the outer and inner pipe may be assembled from shorter sections joinable with couplings. The flotation devices may be incorporated into the couplings. 
     For a preferred embodiment of the invention, the outer and inner pipes are non-concentrically positioned with respect to one another, with inner pipe supports immovably positioned within the outer pipe. The supports position the inner pipe near the upper inner surface of the outer pipe and permit the inner pipe to be rotated so that the level of the perforations in the inner pipe may be adjusted within the chamber of the outer pipe. A minimum of two suction pumps are employed in conjunction with the boom: a first pump to draw a water and oil mixture into the outer pipe; a second pump to draw primarily oil into the inner pipe. The water and oil mixture removed from the outer pipe by the first pump is returned to the spill area. Oil mixed with some water withdrawn from the inner pipe by the second pump is sent to a separator located on a ship, barge or the shore. Oil is stored for subsequent use and the clean water separated therefrom is returned to a unpolluted area of the body of water. 
     In order to accurately adjust the level of the perforations on the inner pipe, the end thereof is equipped with an external circumferential straight-cut gear. A bell rotatable about the end of the outer pipe incorporates an internal circumferential straight-cut gear that meshes with the external gear on the inner pipe. As the bell is rotated about the outer pipe, the inner pipe also rotates. The bell may be equipped with stops to arrest its revolution about the outer pipe, thereby setting the inner pipe at a desired rotational position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a aerial view of the oil recovery system of the present invention, being deployed in combination with the ship in the foreground; 
     FIG. 2 is a side-elevational view of a portion of an oil containment boom section of the oil recovery system of the present invention; 
     FIG. 3 is a side-elevational cross-sectional view of the oil containment boom of FIG. 2, taken through the axis thereof and with the inner pipe section thereof removed; 
     FIG. 4 is a side-elevational view of a perforated inner pipe section of the oil containment boom; 
     FIG. 5 is a side-elevational cross-sectional view of the perforated inner pipe section of FIG. 4; 
     FIG. 6 is a side-elevational cross-sectional view of an assembled oil containment boom, which includes the outer perforated pipe of FIG. 3 with an inner perforated pipe installed therein; 
     FIG. 7 is a cross-sectional view of a first embodiment oil containment boom of FIG. 2, taken through section line  7 — 7  of FIG. 2; 
     FIG. 8 is an elevational view of the right end of the oil containment boom of FIG. 2 showing a first embodiment rotational adjustment mechanism; 
     FIG. 9 is an end elevational view of the oil containment boom after having been fitted with an adjustable flotation device; 
     FIG. 10 is a cross-sectional view of a second embodiment oil containment boom having a combined support and height adjustment device; 
     FIG. 11 is a cross-sectional view of a T-connector attachable to an end of the oil containment boom; 
     FIG. 12 is a cross-sectional view of a quad cross connector attachable between sections of the oil containment boom; and 
     FIG. 13 is a cross-sectional view of a boom section separator coupling; 
     FIG. 14 is a schematic diagram of the boom, the pumps and the oil/water separator at locations A or D and C; and 
     FIG. 15 is a side elevational view of a pair of mating grommets used to anchor a cable to the oil containment boom. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The oil recovery system of the present invention will now be described with reference to the accompanying drawing figures. It is to be understood that the drawings are not necessarily drawn to scale, but are merely intended to be illustrative of the system, its function and use. 
     Referring now to FIG. 1, the oil recovery system  100  includes a floating oil containment boom  101  that is used to surround at least a part of a floating oil slick  102 . For proper operation of the system  100 , suction pumps and a water-oil separator are required. These items may be located on a ship  103 , a barge  104 , on a derrick (not shown) or on the shore (also not shown). In this particular drawing figure, the boom  101  is divided into three sections AB, BC, and CD, each of which is capable of drawing oil from the slick  102 . At locations A and D, oil is being recovered on the ship  103  from the boom sections AB and CD, respectively; at location C, oil is being recovered on the barge  104  from boom section BC. 
     Still referring to FIG. 1, it will be noted that the ship  103  has stored thereon multiple straight containment boom sections  105 , which are preferably fabricated from a tough, lightweight plastic material, such as acrylonitrile butadiene styrene (ABS) or poly vinyl chloride (PVC). As the plastic material is somewhat flexible, the boom sections may be flexed slightly to form a curved structure so that the oil slick  102  may be surrounded by the boom  101 . As the boom must act as a barrier against further spread of the oil slick  102 , 
     Referring now to FIG. 2, this exterior view of the oil containment boom  100  shows the outer pipe section  201 , which has a plurality of apertures  202  along one side thereof, each aperture  202  communicating between the exterior of the pipe section  201  and the interior thereof. It will also be noted that each section  201  has an expanded end portion  203  which serves both as a coupling and as an enclosure for a first embodiment of an inner pipe rotational adjust mechanism (shown in later drawing figures). 
     Referring now to FIG. 3, this cross-sectional view of an outer pipe section  201  shows a pair of supports  301 , in which an inner pipe (not yet shown) is rotatably supported. Also visible in this drawing figure is an internal ring gear  302  rotatable within the expanded end portion  203 , said ring gear having straight-cut teeth  303 . The axis of the internal ring gear  302  is coaxial with the axis of the outer pipe section  201 , and is caged between two positioning rings  304 A and  304 B, both of which are affixed to the interior surface of the expanded end portion  203 . The outer pipe section  201  may also be equipped with an inspection window  305 , which permits water and oil levels within the pipe to be viewed. Boom adjustments may then be made in accordance with the observed levels. 
     Referring now to FIG. 4, a portion of an inner pipe section  401  is sized for rotatable positioning within supports  301 . The inner pipe section  401  also has a plurality of perforations  402  along one side thereof. Inner pipe section  401  is equipped with an external ring gear  403  that is permanently affixed to the exterior surface of inner pipe section  401 . The axis of the external ring gear  403  is coaxial with the axis of the inner pipe section  401 . The external ring gear  403  has straight-cut teeth  404 , which engage the straight-cut teeth  303  of internal ring gear  302 . It will be noted that each inner pipe section  401  has an expanded end portion  405 , which serves as a coupling between adjacent inner pipe sections  401 . FIG. 5 shows a cross-sectional view of the same portion of the inner pipe section  401 . 
     Referring now to FIG. 6, this cross-sectional view of the fully assembled oil containment boom section  600  shows both the inner pipe section  401 , the outer pipe section  201 , the supports  301  in which the inner pipe section  401  is rotatably positioned, the rotatable internal ring gear  302 , the teeth  303  of which are meshed with the teeth  404  of external ring gear  403 . 
     Referring now to FIG. 7, the structure of the support permits a water and oil mixture to flow through the outer pipe section  201 , while still providing caged support for the inner pipe section  401 . An aperture  202  within the outer pipe section  201  is visible in this view, as is an aperture  402  within the inner pipe section  401 . 
     Referring now to FIG. 8, both the expanded end portion  203  of an outer pipe section  201  and an inner pipe section  401  are clearly visible, as are the internal ring gear  301  that is rotatably mounted within the expanded end portion  203 , and the external ring gear  403  that is secured to the outer surface of the inner pipe section  401 . It will be noted that teeth  303  on the internal ring gear engage teeth  404  of the external ring gear  403 . Thus, when the internal ring gear  301  is rotated, it will cause the inner pipe section  401  to rotate. An adjustment cover  405  is held in place to the expanded end portion  203  by a pair of screws  406 . The cover has at least one peg  407  that fits within indentations  408  on the internal ring gear  301 . The indentations  408  may be used to rotate the internal ring gear  301  with a pointed object (not shown). When the cover  405  is installed, the adjusted position of the internal ring gear  301  will be retained. 
     Referring now to FIG. 9, an adjustable flotation device  901  has been fitted to the expanded end portion  203  of an outer pipe section  201 . The flotation device  901  has a pair of buoyancy chambers  902 A and  902 B. The buoyancy of chamber  902 A is adjustable, while that of  902 B is invariable. It will be noted that chamber  902 A is equipped with upper and lower valves ( 903 U and  903 L, respectively), by means of which the buoyancy of the chamber  902 A may be adjusted by either admitting or expelling fluid therefrom. The two buoyancy chambers  902 A and  902 B are interconnected by a hinged bracket consisting of a first half  904 A and a second half  904 B, which are interconnected by a hinge  905 . Buoyancy chamber  902 A is attached to bracket half  904 A at point E, while chamber  902 B is attached to bracket half  904 B at point F. Each bracket half  904 A and  904 B has an extension  906 A and  906 B, respectively. Using bolts  907 , the extensions  906 A and  906 B may be securely clamped to retain a cable  908 A, which ties together all of the interconnected pipe sections  201 . The cable  908 A is used to tie all of the pipe sections  201  together so that wave action and currents will not cause them to break. The bracket  904 A/ 904 B is fitted with a pair of locator pins  909 A and  909 B, while the outer pipe is fitted with a pair of locator holes  910 A and  910 B at each bracket mounting position. It should be obvious that the size of the chambers  902 A and  902 B should be sized for proper buoyancy. Their distance from the boom can also be increased to enhance stability in choppy water. It will be noted that the hinge  905  has an aperture through which a second cable  908 B may be inserted. To avoid wear on the cable, a pair of mating, threaded, slotted-barrel grommets  1501 / 1504  shown in FIG. 15, may be used as a buffer. The cable  908 B not only assists in tying together all of the pipe sections  201  together so that wave action and currents will not cause them to break, but it may also serve as the attachment point for an attachable flotation device  913 , which may extend the length of the boom. Bracket  904 A/ 904 B also has a slot  911 , within which a pressurized air hose  912  may be secured. Pressurized air carried by hose  912  may be used tor power pumps located at a distance from the ship  103 . Flotation device  913  may be a shaped block of foam material and may be attached to the cable  908 B with clips or other similar attachment means. 
     Referring now to FIG. 10, a second embodiment of the oil containment boom  1000  incorporates both support and height adjustment of the inner pipe section  1001  in a single support/height-adjustment device  1002 . A threaded shaft  1003 , having a socket  1004  at one end thereof for engaging a wrench, is anchored within a pair of diametrically opposed apertures  1005 U and  1005 L in the walls of the outer pipe section  1006 . The threaded shaft  1003  passes through a female threaded collar  1007  that is rigidly affixed with a pair of diametrically opposed apertures  1008 U and  1008 L in the walls of the inner pipe section  1002 . As the shaft  1003  is rotated, the height of the threaded collar  1007  within the outer pipe section  1006  changes. It will be noted that for this second embodiment oil containment boom, the inner pipe section is perforated on both sides thereof, with the perforations  1009  being formed in the top half of the inner pipe section  1002 . As the height of the inner pipe section is adjusted without rotating it, perforations may be placed on both sides of the inner pipe section  1002 . A locknut  1010  serves to both seal the upper aperture  1005 U in the outer pipe section  1006  and to lock the threaded shaft  1003  at a set position. It will be noted that the outer pipe section  1006  is perforated on only one side thereof. That side of the boom  1000  is placed against the oil slick  1002 . 
     Referring now to FIG. 11, a female T-connector  1100  is employed at boom end locations A and D. The T-connector includes a main body  1101  having three female sockets  1102 A,  1102 B and  1102 C, a 90-degree elbow  1103 , a stub nipple section  1104  coupled to the elbow  1103 , a flexible coupler  1105  coupled to both the stub nipple section  1104  and an inner exit pipe  1106 . The exit pipe  1106  passes through a male plug  1107 , which is used to cap one of female connector socket  1102 B of the T-connector main body  1101 . The flexible coupler  1105  permits the inner pipe sections  401  coupled to the elbow  1102  to be rotated or raised and lowered (depending on which support and height adjustment mechanisms are utilized). Also coupled to the main body  1101  is an outer exit pipe  1108 , to which a first pump (See FIG. 14) is attachable. A water and oil mixture is withdrawn from the outer pipe section  201  that is coupled to female connection socket  1102 A along path  1109 , passing through the outer exit pipe  1108  that is coupled to female connection socket  1102 C, then through the first pump, after which it is returned to the oil spill area  102 . A primarily oil mixture containing some water and following path  1110 , is withdrawn from inner pipe sections  401  through the elbow  1103 , through the stub nipple  1104 , through the flexible coupler  1105 , through the inner exit pipe  1106 , through a second suction pump, following which it is sent to a separator (see FIG.  14 ). 
     Referring now to FIG. 12, a quad cross connector  1200  is attachable between boom sections where a pumping station is to be established. For example, in FIG. 1, a quad cross connector  1200  would be positioned at location C in the boom  101 . At location B, there is a block between two adjoining boom sections. Thus from location B, flow is bidirectional: toward locations A and C. The quad cross connector  1200  includes a main body  1201  having four female connection sockets  1202 A,  1202 B,  1202 C and  1202 D, a 90-degree elbow  1103 , a stub nipple section  1104  coupled to the elbow  1103 , a flexible coupler  1105  coupled to both the stub nipple section  1104  and an inner exit pipe  1106 . The exit pipe  1106  passes through a male plug  1107 , which is used to cap one female socket  1202 B of the T-connector main body  1201 . The flexible coupler  1105  permits the inner pipe sections  401  coupled to the elbow  1103  to be rotated or raised and lowered (depending on which support and height adjustment mechanisms are utilized). Outer pipe section  201  are inserted within female connector sockets  1202 A and  1202 C. A plug  1203  blocks the path through female connector socket  1202 C and also provides a mounting socket for a new run of inner pipe sections  401 . A water and oil mixture is withdrawn from the outer pipe section  201  that is coupled to female connection socket  1202 A along path  1108 , passes through the outer exit pipe  1107  that is coupled to female connection socket  1202 D, then through the first pump (see FIG.  14 ), after which it is returned to the oil spill area  102 . A primarily oil mixture containing some water and following path  1109 , is withdrawn from the inner pipe sections  401  through the elbow  1103 , through the stub nipple  1104 , through the flexible coupler  1105 , through the inner exit pipe  1106 , through a second suction pump, following which it is sent to a separator (see FIG.  14 ). 
     Referring now to FIG. 13, a boom section separator  1301  is shown coupled to two oil containment boom sections  600 A and  600 B, each of which comprises an outer pipe section  201  and an inner pipe section  401 . Arrows  1303 A and  1303 B indicate the relative flow directions in each boom section of a water and oil mixture drawn from the oil spill. Arrows  1304 A and  1304 B indicate the relative flow directions of a primarily oil mixture in inner pipe sections  401 . It will be noted that the boom section separator  1301  includes a pair of opposed sockets  1301 A and  1301 B, each of which is sized to receive an outer pipe section  201 . It also includes a pair of opposed sockets  1302 A and  1302 B, each of which is sized to receive an inner pipe section  401 . In the boom arrangement of FIG. 1, a boom section separator  1301  would be used at location B. 
     Referring now to schematic diagram of FIG. 14, plumbing connections, pump locations and fluid flows are shown for the sake of clarification. A first type suction pump  1401  is coupled to a stub pipe  1107  at both locations C and D. Each stub pipe provides a connection to the interior of a run of the outer pipe sections  201 . Thus, each first type suction pump  1401  draws a mixture of water and oil from the outer pipe sections  201 , which are continually being refilled through apertures  202 . Through pipe connections  1402 , the water and oil mixture is returned to the oil spill area  102 . The boom separator  1401  (at location B) would be the start of the run of boom sections that are emptied at location C. The connection arrangement at location A would be identical to that at D. However, the boom separator  1401  (at location B) would be the start of the run of boom sections that are emptied at location A. 
     Still referring to FIG. 14, a second type suction pump is connected to each of inner exit pipe  1105 , and the flow through  1404 A and  1404 B, respectively, directed to a separator  1405 . The inner pipe sections are being continually refilled from the water and oil mixture in the outer pipe sections  201  through perforations  402 . Oil from the separator is removed through pipe  206  and stored, while water taken from the mixture through pipe  1407  is sent to open (unpolluted) water outside the spill area. It should be mentioned that because location C and D will be typically far removed from one another, a separate separator  1405  will be required at each location. The drawing merely depicts the flow diagram. As shown in FIG. 1, the separator  1405  may be an integral part of the spill clean-up ship  103 . 
     Referring now to FIG. 15, the cable  908 B may be protected against abrasion by the pivot aperture of hinge  905  with a pair of mating threaded, slotted-barrel grommets  1501  and  1504 . The first grommet  1501  is configured with male threads  1502  and a slot  1503 , which slips over the cable  908 B. The second grommet  1504  is configured with female threads  1505  and a slot  1506  which slips over the cable. The male end adjuster is similar to the slotted barrel end adjusters used on bicycle and motorcycle brake levers. When the slots are unaligned with respect to each other, the cable is secured within the mated grommets, which may be tightened against opposite sides of bracket hinge  905 . 
     Although only several embodiments of the invention has been heretofore described, it will be obvious to those having ordinary skill in the art that changes and modifications may be made thereto without departing from the scope and the spirit of the invention as hereinafter claimed.