Abstract:
The oil spill recovery vessel is configured particularly for operations in relatively shallow water. The vessel is of catamaran configuration, with a large number of slowly rotating discs installed on a lateral rotary axle at the bow of the vessel. A wiper bears against each of the two surfaces of each disc, with oil residue running along the wipers being collected in a holding tank or tanks on the vessel. The oil may be pumped to other storage vessels or containers. The lateral axle on which the discs are installed is free to rise upward in the event that the discs contact a solid object or a shallow bottom. Thus, the discs are of relatively large diameter to provide relatively greater surface area across the surface of the water than is the case with vessels operating with smaller diameter discs.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/370,413, filed Aug. 3, 2010. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates generally to vessels and equipment configured for environmental cleanup work, and particularly to an oil spill recovery vessel that provides a seagoing vessel configured for recovering crude oil or the like from the surface of a body of water. 
         [0004]    2. Description of the Related Art 
         [0005]    The development of technology permitting the drilling of oil and natural gas wells beneath the surface of the sea has greatly expanded the field of energy recovery. While the recovery of such oil and natural gas deposits has served to expand and continue the availability of energy produced by such deposits, this technology is not without its potential problems. 
         [0006]    When an oil well blowout or spill occurs on land, it is generally relatively easy to contain the spill and recapture the otherwise lost oil. Environmental damage is generally kept to a minimum. However, when an oil spill occurs at sea, the potential for environmental damage is considerably greater due to the freely flowing crude oil that spreads to a wide area on the surface from its source at the sea floor. Moreover, winds, currents, and tidal flow can carry such surface oil over a large expanse of the surface, eventually carrying it to broad expanses of the shoreline, perhaps extending for several hundred miles. The associated damage to wildlife, seafood sources, and other environmental concerns may be correspondingly huge. 
         [0007]    As a result, a number of different vessels and devices have been developed in the past for recapturing waterborne oil from such oil spills. This equipment may function by means of a few different principles, e.g., floating barriers intended to keep the surface oil from spreading, materials for absorbing the oil, and machinery operated from moving vessels that are driven through the oil to recover or collect the oil on the surface. 
         [0008]    A number of such oil recovery vessels have been developed in the past, with most having one or more large rotating drums to collect the oil on the surface(s) of the drum(s), whereupon it is removed by a wiper(s) for storage in tanks on the vessel or pumped to another storage facility. Others have been developed with discs rather than drums, with the greater surface area of the discs providing greater recovery efficiency. However, generally speaking such oil recovery vessels are configured for operation in relatively deep water. Unrecovered oil is still free to drift to shallower areas closer in to shore, where the oil poses its greatest threat. 
         [0009]    Thus, an oil spill recovery vessel solving the aforementioned problems is desired. 
       SUMMARY OF THE INVENTION 
       [0010]    The oil spill recovery vessel has a shallow draft and is configured particularly for oil recovery missions in relatively shallow water, although it may be used in deeper water as well. The vessel has a catamaran-type hull with a closed pilothouse or cabin to protect the operators from chemical vapors arising from an oil slick on the water surface. 
         [0011]    A large number of rotating oil recovery discs are disposed upon a lateral axle at the bow of the vessel. Wipers bear against the two opposed surfaces of each disc to remove the oil from the discs. The oil runs from the wipers to be collected in holding tanks on the vessel, where it may be transferred to other vessels or containers, as desired. 
         [0012]    The vessel may be powered by a pair of motors, e.g., short shaft outboard motors or the like, or may be powered by inboard engines. The rotation of the discs may be powered by various means. The lateral axle with which the discs rotate floats freely to allow the discs to rise in the event that they contact a solid object or shallow bottom. This allows the discs to be of relatively large diameter, thereby providing greater surface area across the water surface to gather more oil than would be the case with smaller diameter discs. The discs rotate at a relatively slow speed in order to avoid the pickup of water with the oil residue. 
         [0013]    These and other features of the present invention will become readily apparent upon further review of the following specification and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is an environmental, perspective view of an oil spill recovery vessel according to the present invention, showing its general operation. 
           [0015]      FIG. 2  is a right side elevation view of the vessel of  FIG. 1 , showing various details thereof. 
           [0016]      FIG. 3  is a top plan view of the vessel of  FIG. 1 , showing further details. 
           [0017]      FIG. 4  is a top plan view of the holding tank layout of the vessel of  FIG. 1 , showing baffling and other details. 
           [0018]      FIG. 5  is a right side elevation view of the oil recovery disc assembly of an oil spill recovery vessel according to the present invention, showing the articulation of the disc assembly upon contacting a shallow area. 
           [0019]      FIG. 6  is a partial side elevation view in section of the bow of the vessel of  FIG. 1  and its oil recovery discs, showing the installation of the wipers and their communication with the holding tank. 
           [0020]      FIG. 7  is a detailed end elevation view in section of a single wiper assembly for an oil spill recovery vessel according to the present invention, showing various details thereof. 
       
    
    
       [0021]    Similar reference characters denote corresponding features consistently throughout the attached drawings. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0022]    The oil spill recovery vessel is particularly adapted for the recovery of crude oil (or other liquids floating on the surface of a body of water) from the surface of a shallow body of water. The oil recovery mechanism articulates to rise when encountering a shallow obstruction, thereby allowing the vessel to function in shallower water than conventional oil recovery vessels. 
         [0023]      FIGS. 1 through 3  provide environmental perspective, right side elevation, and top plan views, respectively, of the oil spill recovery vessel  10 . The vessel  10  has a catamaran-type hull  12 , i.e., having port and starboard hull units  12   a  and  12   b , and a deck  14  spanning the two hull units. The hull  12  has a forward end  16  defining a laterally disposed oil recovery bay  18 , and an opposite aft end  20  where the propulsion unit(s) is/are situated. 
         [0024]    The oil recovery assembly articulates on laterally spaced first and second axle support arms  22   a  and  22   b . Each arm  22   a ,  22   b  has a rearwardly disposed attachment end  24   a ,  24   b  pivotally attached to the hull  12  (or deck  14 ) by an axle support arm pivot  26   a ,  26   b . The opposite, forwardly disposed axle support ends  28   a  and  28   b  of the arms  22   a ,  22   b  have a selectively rotating axle  30  (best seen in  FIGS. 2 ,  5 , and  6 ) extending laterally between the arms  22   a ,  22   b . The axle  30  spans the lateral width of the oil recovery bay  18 . 
         [0025]    A series of laterally spaced apart oil recovery discs  32  are immovably affixed to the axle  30  so that the discs  32  rotate with rotation of the axle  30 . The discs  32  are each formed of an oleophilic material, e.g., polypropylene, high-density polyethylene, or other oleophilic polymer. Oil is known to adhere to such materials, while water does not readily adhere to such plastic materials. Any material having such properties may be used for the manufacture of the discs  32 . Each of the discs  32  has two mutually opposed surfaces, thus significantly increasing the surface contact area of the oil recovery unit in comparison to drum type units. 
         [0026]    A laterally and pivotally disposed wiper axle  34  is located rearwardly of the oil recovery bay  18 , as shown most clearly in  FIG. 6  of the drawings. A plurality of wiper assemblies  36  extend forwardly from the wiper axle  34 . The rearward end of each of the wiper assemblies  36  is immovably affixed (e.g., welded, bolted, etc.) to the wiper axle  34  to pivot in unison therewith. The top plan view of  FIG. 3  clearly shows that the axle support arms  22   a  and  22   b  are significantly longer than the wiper assemblies  36 , and the wiper axle  34  (shown in  FIG. 6 ) is located correspondingly farther forward than the two axle support pivots  26   a ,  26   b . The forward end  38  of each wiper assembly  36  rides on a spacer  40 . One such spacer  40  is positioned between each of the oil recovery discs  32 , and an additional spacer  40  is disposed adjacent each of the outermost discs. 
         [0027]      FIG. 7  provides an end elevation view in section of an exemplary wiper assembly  36  disposed between two adjacent oil recovery discs  32 . Each wiper assembly  36  includes upper and lower clamps  42   a  and  42   b  that grip wiper elements  44  therebetween. A conventional bolt and nut assembly  46  or other suitable fastener is used to secure the two clamps  42   a ,  42   b  together. (The head of the bolt is behind the spacer  40 , in the orientation of the  FIG. 7  view.) Each of the clamps  42   a ,  42   b  preferably forms a shallow trough, with the wiper elements  44  angled laterally upward to bear against the surface of the adjacent oil recovery disc  32 . In this manner, oil wiped from the surface of the disc  32  runs downward into the trough of the upper clamp  42   a , and then rearward for collection as described further below. 
         [0028]    The wiper elements  44  are preferably formed of a slightly flexible plastic material, e.g., Nylon or the like. Nylon may also have an oleophilic property, as in the case of the polymers used to form the oil recovery discs  32 . However, the wiper assemblies  36  slope downwardly and rearwardly toward their attachment points to the wiper axle  34 , as shown in  FIG. 6 . When the oil accumulated by the wiper elements  44  reaches sufficient mass and volume, it will run downwardly and rearwardly from the wiper assemblies  36  to an oil recovery tray  48  (best shown in  FIG. 1 ), running from the rear of the feed tray through a forwardly disposed opening  50  into the holding or storage tank(s)  52 , best shown in  FIG. 4 . The holding or storage tank(s)  52  preferably include at least a few longitudinally disposed baffles  54  therein to reduce instability in roll of the vessel  10  due to lateral slosh of the relatively low viscosity recovered crude oil. 
         [0029]    It will be understood that it is necessary to provide some form of power to rotate the axle  30  of the oil recovery discs  32 , and thus the discs  32  themselves, in order for them to pick up any oil film floating atop the surface of the water. The rotary power for the oil recovery discs  32  may use any practicable principle, e.g., mechanical, hydraulic, electric, pneumatic, etc. In the exemplary system described herein, a conventional internal combustion engine is used to drive a conventional hydraulic pump, with the housing  55  of the engine and pump assembly being shown in  FIGS. 1 through 3 . The hydraulic pump supplies hydraulic fluid under pressure to a hydraulically driven oil recovery disc motor  56 , which, in turn, drives the oil recovery discs  32  by means of the axle  30 . 
         [0030]    It is desired that the oil recovery discs  32  rotate at a relatively slow speed for optimum efficiency in oil recovery. Accordingly, the pump and/or motor  56  have one or more conventional rotational speed reducing means or low speed drives (e.g., gearboxes, chain drives, etc.) to reduce the rotational speed of the oil recovery discs  32  to the desired speed. It has been found that movement of the disc surface through the film of oil on the surface of the water at a rate of about one foot per second (more or less) is about optimum. A slower rate results in less oil recovery per unit of time, while a much faster rate will entrain water on the discs  32 , resulting in the undesired water then being transferred into the holding or storage tank(s)  52  along with the desired recovered oil. With an exemplary disc diameter of about seven feet, a rotational speed on the order of 2.7 revolutions per minute will drive the rims  58  of the oil recovery discs  32  at the desired one foot per second travel speed through the surface of the water. However, it will be understood that faster or slower rates of travel of the disc rims  58  through the water may be desirable under various circumstances, e.g., the viscosity and/or other properties of the oil or other liquid being recovered, the specific material of which the discs  32  are formed, and perhaps other considerations. 
         [0031]    The propulsion system for the exemplary vessel  10  of the present disclosure is a separate system from the power plant provided to operate the oil recovery discs  32 . In the exemplary vessel  10 , first and second outboard motors  60   a  and  60   b  are provided at the stern  20  of the vessel  10 . These motors  60   a ,  60   b  are preferably relatively powerful outboards, and are equipped with relatively short shafts (as shown in  FIG. 2  of the drawings) to facilitate operation of the vessel  10  in shallow waters, e.g., close in to the shoreline. Alternatively, other propulsive units may be provided, e.g., inboard diesel or spark ignition engines, etc., if desired. 
         [0032]    It will be recognized that the operating environment of the oil spill recovery vessel  10  subjects the personnel on board to the evaporative byproducts of the spilled material. It has been found that prolonged breathing of such byproducts (crude oil vapors and fumes, etc.) can result in various respiration problems or difficulties for many people. Accordingly, the oil spill recovery vessel  10  is provided with an enclosed pilothouse  62  on the deck  14 . Fresh, uncontaminated air may be supplied to the pilothouse  62  by means of a conventional environmental control system  64  (e.g., air conditioner and/or heat pump with, suitable air filtration, etc.) communicating with the interior of the pilothouse. 
         [0033]    The oil spill recovery vessel  10  is suitable for the recovery of surface spills of oil and/or other liquids on virtually any body of water where operation of the vessel  10  is appropriate. However, the vessel  10  is particularly well adapted for operation in relatively shallow waters, as noted further above. The two catamaran flotation hulls  12   a  and  12   b  of the vessel  10  are relatively high in volume for the weight of the vessel, thus providing relatively shallow draft. Moreover, the oil recovery discs  32 , or more specifically the arms  22   a ,  22   b  supporting the axle  30  of the discs  32 , pivot or articulate upwardly and downwardly. This allows the discs  32  to rise in the event that they contact a solid object, such as the underlying shallow seabed or bottom B, as shown in broken lines in  FIG. 5 . 
         [0034]    As the oil spill recovery vessel  10  operates, the spilled oil on the surface of the water is picked up by the oleophilic recovery discs  32  and carried upwardly and rearwardly around the discs  32 , where it encounters the wiper assemblies  36 . Additional efficiency may be provided by the installation of sweep boards  66   a  and  66   b  extending forwardly and laterally outward to each side of the oil recovery bay  18  in order to guide a lateral swath of surface oil wider than the beam of the vessel  10  into the recovery discs  32 . Oil adhering to the surfaces of the discs  32  is wiped from the discs by the wiper elements  44 , the oil then running downwardly and rearwardly in the troughs of the wiper assemblies  36  onto the oil recovery tray  48  and into the holding or storage tank(s)  52 . The vessel  10  is capable of recovering reasonably large volumes of oil from the surface of the water, depending upon conditions (thickness of the oil film, roughness of the water surface, etc.). It is anticipated that under certain circumstances the holding or storage tank(s)  52  may be filled in perhaps five hours of operation of the vessel  10 . Accordingly, one or more lightering (transfer) pump(s)  68  may be provided for the transfer of the accumulated oil to larger vessels, and thence to on-shore storage, disposal, and/or processing/refining facilities, thereby allowing the oil spill recovery vessel  10  to continue the oil spill recovery operation with maximum efficiency. 
         [0035]    It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.