Abstract:
A method of and a device for separating oil from water, or a lighter fluid floating on a heavier fluid or denser fluid. The device includes floating arms in V-shape formation that gather the fluids into a collecting channel which device thickens the layer of the lighter fluid to separate the lighter fluid using a drain where a self-adjusting float sits above the heavier fluid and below the lighter fluid. The lighter fluid is gravity discharged through a conduit into container to be later pumped out from the container or directly pumped from the drain.

Description:
PRIORITY INFORMATION 
     The present invention claims priority from U.S. Provisional Application Ser. No. 61/429,506 filed, Jan. 4, 2011 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention is directed to the separation of two insoluble fluids of different specific gravities. In particular, the invention is directed to an apparatus and a method of separating fluids using gravity as an inexpensive cost effective solution. 
     2. Description of Related Art 
     Several types of systems have been developed for efficient separation of oil from water. These include booms and various types of skimmers such as belt skimmers, drum or barrel skimmers, tube skimmers, and suction skimmers such as those disclosed in U.S. Pat. No. 6,277,287. The separation systems vary and include the following: weir separators, gravity separators, coalescing separators and oleophilic such as those disclosed in U.S. Pat. No. 5,217,611. 
     Booms help concentrate oil into thicker surface layers so that other collection methods can be used more effectively. They come in many shapes and sizes, with various levels of effectiveness in different types of water conditions. U.S. Pat. No. 3,635,032 discloses two floating arms, which form a V-shape configuration however the arms are not connected to a bottomless opened channel. 
     Weir skimmers function as dams allowing the oil floating on top of the water to flow over the dam and be trapped in a well inside. Typically, the trapped oil and water can then be pumped out through a pile or hose. Typically, in weir skimming devices, the weir is buoyant to float beneath the level of the liquid causing the liquid to move over the weir and then only the top layer of the liquid including the lighter fluid passes over the weir. U.S. Pat. No. 7,357,860 discloses a floating weir, which utilizes an air-filled float having buoyancy such that the weir is at or above liquid level. U.S. Pat. No. 6,063,274 discloses a self-adjusting skimmer having a buoyant body maintaining an apparatus at water surface level. U.S. Pat. No. 7,767,085 discloses a skimmer with an internal float. While the inventor in U.S. Pat. No. 6,063,274 discloses a skimmer comprising a buoyant body. 
     Similar concepts are used for pool skimmers in order to remove debris from the water surface as disclosed in U.S. Pat. No. 4,746,424 and U.S. Pat. No. 5,143,605. 
     U.S. Pat. No. 7,807,051 teaches a flexible sleeve connected to a float. This patent further teaches using a round float and does not go into details of the float to use gravity to collect oil. Furthermore, this reference collects both oil and water, and fails to make the float from paraffin. 
     A key factor in the efficient use of gravity separators that utilize an outlet for discharge of the lighter fluid, is maintaining a certain height or level of the fluid to keep the interface between the two different fluids at a certain distance below the lighter fluid discharge outlet. An issue in using gravity separators in open waters is maintaining a sufficient level so that water level or heavier fluid does not rise above the discharge outlet for the oil or lighter fluid. There are several methods and apparatus that attempt to overcome the problem. U.S. Pat. No. 5,498,348 discloses a valve that controls flow of liquid into the vessel so as to maintain the separating apparatus near the surface of the body of liquid. U.S. Pat. No. 6,315,131 discloses a separate discharge port for heavier water in order to maintain fluid levels. 
     The present invention overcomes problems with prior art devices and methods by providing an efficient, cost effective, and uncomplicated device and a method for separating insoluble fluids such as separating oil from water in open waters. 
     BRIEF SUMMARY OF THE INVENTION 
     It is an objective of the present invention to provide an apparatus for separating two insoluble fluids of differing specific gravities where the apparatus is easy to operate and is able to operate in open waters. The invention envisions using a narrow, bottomless catchment used to thicken the lighter fluid on top of a heavier fluid to facilitate recovery of the lighter fluid. 
     It is also an objective of the present invention to provide a self-adjusting gravity separator for separating a mixture of two insoluble fluids, such as oil and water having different densities, collected through a narrowing cavity, a drain, and a discharge tube. 
     It is yet another objective of present invention to provide an apparatus that includes a drain that is made of a substance having a density lighter or nearly equal to the specific gravity of water or a heavier fluid thus allowing the drain to float slightly above the water surface or denser fluid. 
     It is yet another objective of the present invention to use the drain in conjunction with a narrowing catchment having a cavity, where the cavity acts as an oil consolidation system, which thickens the layer of oil at the water surface in a channel. In one embodiment of the channel, the channel contains a back wall that contains an opening. In another embodiment of the channel, its back wall has no opening. 
     Another objective of the present invention is to provide a self-adjusting drain attached to a catchment adjacent to the narrowing cavity allowing the drain to move in conjunction with the narrowing cavity thereby allowing oil or another water insoluble fluid, having a specific gravity less than water, to be discharged through the drain then collected into a nearby container either separate from a ship or integrated as part of a ship. The fluid can be collected in the container by any means, such as, but not limited to, siphoning, pumping, skimming, adhesion skimmers, draining, or combinations thereof. It is contemplated that a means for moving the fluid through the cavity can be implemented, by pushing or pulling the catchment with a naval vehicle, or moving the fluids through the catchment with machinery, or a combination of the two motions. The catchment can also be self-propelled. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of a first embodiment of a separating system. 
         FIG. 2  shows a side view of the separating system. 
         FIG. 3  is a top view of the separating system the self-adjusting drain in various titled positions of the present invention. 
         FIG. 4  is a cross-sectional view of  FIG. 3  at  4 - 4 . 
         FIG. 5  is a cross-sectional view of another separating system. 
         FIG. 6  is a close up view of the mechanics of the collected oil over water. 
         FIG. 7  is a top view of a variation of a drain. 
         FIG. 8  is a cross-sectional view of the drain shown in  FIG. 7  at section  7 - 7  and  FIG. 5 . 
         FIG. 9  is a side view showing a further variation of the drain. 
         FIGS. 10   a - 10   f  show cross-sectional variations of the float of the drain. 
         FIG. 11  shows a variation of another drain in cross-section. 
         FIG. 12  shows another variation of the drain in cross-section. 
         FIG. 13  shows another variation of the catchment in cross-section. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1 and 4  shows an oil collecting system  100  including a catchment  1 , a container  18 , a pump  20 , collecting conduit  19 , and an exit conduit  21 . As seen in  FIGS. 1 and 2 , the catchment  1  comprises a U-shaped channel  1   f  with a pair of arms  1   a  connected with hinges  1   b , see  FIG. 4 . The arms  1   a  contain a tapered edge  1   h  decreasing its height from the u-shaped channel  1   f  to a front portion of the arms  1   a . The arms  1   a  remain fixedly open to a cross brace  1   c  being connected between the arms  1   a . See  FIGS. 1 and 3 . As seen in  FIGS. 2 and 4 , the drain  30  is attached to the channel  1   f  using a u-shaped bracket  16  and fasteners  15 . The drain  30  includes a first conduit  3   a  and a second conduit  3   b  as shown in  FIG. 8 . The second conduit  3   b  is fixed to the first conduit  3   a  via any method known. The second conduit  3   b  then connects to a float  3   c , which is partially submerged in the water, preferably 51-99% of its volume. The second conduit  3   b  as seen in  FIGS. 4 ,  5 ,  8  and  9  is made from a flexible material so that the second conduit rises to the water level FD and below the oil FL collected. The rising of the second conduit  3   b  is caused by the float  3   c  thus placing the top surface of the float above the surface of the water FD. The float  3   c  contains an opening  3   e  so that oil FL passes therein due to gravity. According to  FIG. 8 , the oil FL will flow according to the direction  3   f  and be collected in the container  18  to be pumped out through the collecting conduit  19  via the pump  20  fixed on the container  18  and exiting through exit conduit  21 . 
     The invention contemplates using a method for collecting oil from water. When fluids FL, FD pass through the arms  1   a , the fluids FL, FD are gathered at the channel  1   f , the speed of the fluids changes due to the changing width of the cavity  1   g ,  FIG. 3 , formed between the arms  1   a . As the width of the cavity  1   g  decreases, the fluid speed increases. Since the channel  1   f  is opened at the bottom, the speeds of the fluids will increase less than as compared if the bottom was closed. The oil FL will increase in thickness and depress the level of the water as the water flows out the bottom of the channel  1   f . It is assumed, of course, that the fluids are not forced into the channel  1   f  at a rate so great that the water cannot pass out of the channel  1   f  before there is overflow or backup. Assuming no overflow or backup, the fluids can leave the channel  1   f  either at a rear end or through the open bottom of the channel  1   f.    
     As seen in  FIG. 6 , if the conditions are assumed with zero impedance of fluids escaping through the bottom of the channel  1   f , then assuming that the channel walls extends sufficiently far into the denser fluid, FD, there will be no increase in the speed of the denser fluid entering and an leaving through the bottom of the channel  1   f . At the same time, the lighter fluid FL, will collect in an ever thickening layer as it passes through the arms  1   a . The weight of this thickening layer of FL within the cavity  1   g  will depress level of fluid FD, within the channel to outside of the channel, essentially reaching an equilibrium point where the weight of the total fluid columns are equal inside and outside of the channel  1   f . In an ideal situation, the velocity of fluid FL would not increase because the depression of the fluid FD would provide an increased cross-section essentially equal to that of the entering fluid FL. 
     Also, depending upon the speed at which the fluids are introduced to the catchment, one could generate a wave or wave crest in one or both of the fluids as well as increased turbulence, which could affect flow rates and could result in dispersal of one fluid in the other, both of which would be counter productive. One skilled in the art will understand that to minimize waves one will adjust the speed of the catchment based on conditions of the fluids. 
     Whatever the actual shape of the channel and the bottom exit way, the goal is to force fluids into the channel and the cavity at a rate which will not cause an overflow or backup, and which will permit the denser fluid, FD, to escape out the bottom of the channel, minimizing to the extent possible, the increase in velocity of either fluid. 
     In an ideal case, as shown in  FIGS. 3 and 6 , the mechanics of the fluid can be explained by a side view of the fluids entering a hypothetical cavity  1   g  at velocity V entry , no surface wave, with no impedance to FD flowing out the bottom of the channel  1   f , no turbulence, and no wave or wave crest formation where:
         W entry =the width of the cavity as the fluids enter,   W exit =the width of the cavity as the fluids exit,   E 0 =base elevation of denser fluid, F D , in the environment and entering the cavity,   H FLentry =the depth (or height) of F L  on top of F D  as the fluids enter the cavity,   H FLexit =the depth (or height) of F L  on top of F D  as the fluids exit the cavity,   H FDdelta =the change in elevation of the surface of F D  as a consequence of the change in depth of F L ,   Ventry=velocity of fluids entering the cavity,   Vexit=velocity of fluids exiting the cavity,
 
Under the conditions shown in  FIG. 6 ,
 
 V entry= V exit,
 
and
 
 H   FLentry   ×W   entry   =H   FLexit   ×W   exit ,
 
or
 
 H   FLexit =( H   FLentry   ×W   entry )/ W   exit  
 
the depression of F D  below E 0  is
 
 H   FDdelta =( H   FLexit   −H   FLentry )×( S   FL   /S   FD )
 
where
   S FL =Specific Gravity of F L , and   S FD =Specific Gravity of F D .       

     So, a narrow, bottomless channel, in the absence excessive turbulence so that laminar flow can be maintained, can be used to increase the head (thickness or depth of the lighter, upper layer of fluid. If H FLexit  is thick enough, the fluid F L  can be removed by a variety of methods, such as siphoning, pumping, skimming or adhesion skimmers from the top out of a bottomless channel  1   f  attached to the narrow end of the cavity  1   g . These methods are well known. 
     F L  can also be removed by draining from the bottom in a passive mode. In this case, the drain is in the catchment and set to float or otherwise remain just at or above the level of F D  so that F L  can drain into a vessel attached to the drain. As shown in  FIG. 6 , box x represent the wings  1   a  of the catchment thus gathering fluids FD, FL. 
     The top of the drain should float on F D , in and at the bottom of F L , such that F L  can flow into the drain mixed with a minimum or no F D . To accomplish this goal, the top of the drain must be able to move up and down with the level of F D  and staying substantially parallel with the surface of the water FD especially during wave motion. Therefore the specific gravity of the moveable portion of the drain, S drain , must be less than S FD  and greater that S FL , or
 
 S   FL   &lt;S   drain   &lt;S   FD .
 
     This can be accomplished by any means, including, but not limited to the following: having the top of the second conduit  30   b ,  60   b  slide in and out of (or around) the first conduit  30   a ,  60   a  the drain, with or without an intermediate seal  50  between the two ( FIGS. 11 ,  12 ), or having the top of the drain connected to the bottom of the drain with a flexible sleeve  3   b , such as a cloth sleeve kept from collapsing by a coil of wire  3   d  or plastic or other material in the form of a large “slinky” toy ( FIGS. 5 and 8 ) or supported by rings  301  or other technique to prevent collapse or blockage, all so that top of the drain can move up and down to stay on top of FD and at the bottom of FD. Whether or not specifically set forth above, the bottom of the drain is attached to the collecting container  18  and the top of the drain can move up and down with the level of F D . 
     It is contemplated that the channel  1   f  and the arms  1   a  contain floating devices  5 ,  6  to keep them afloat the water FD as seen in  FIGS. 1 ,  2 , and  4 . The floating devices  5 ,  6  are attached to the channel  1   f  and the arms  1   a  in any fashion according to those skilled in the art. As seen in  FIG. 4 , a beam  1   d  connects across a top portion of the channel  1   f  so that a guide  1   e  projects therefrom into the drain  3 . The guide  1   e  extends so that it remains in the first conduit  3   a  and the second conduit  3   b  slides along the guide  1   e  thus limiting the freedom of motion of the second conduit  3   b  and the float  3   c  with respect to the top surface of the water FD and preventing the float  3   c  from flipping over. The guide  1   e  comprises a rod made from any material and can project from any part of the channel  1   f.    
     The second conduit  3   b  is made from any flexible material. One end of the second conduit  3   b  is connected to the first conduit  3   a  via any connecting means. The means will include tape, adhesive, fasteners, stitching, external rings, clamps, strings, ties, sleeves, or vulcanizing. The other end of the second conduit  3   b  is connected to the float  3   c  either partially covering the float  3   c  or wrapping the float  3   c  entirely. If the flexible material is wrapped around the float  3   c , a tie  4  will hold the wrap. It should be contemplated that the second conduit alternatively can be fixed to the float  3   c  by any known connecting means instead using a tie  4 , or using a combination of connecting means. 
       FIG. 9  shows an embodiment of the drain  300 . Here, the second conduit  3   b  is structurally supported using axially spaced rings  301  either located outside or inside the second conduit. The rings  301  are taped or retained using stitched cloth  302 . In the drain  3  shown in  FIG. 7 , a coil spring or slinky  3   d  is used to give structural support to the second conduit  3   b  and is connected to the second conduit  3   b  again by any connecting means. It will be preferable to keep the coil spring or slinky  3   d  inside the second conduit so that the second conduit does not collapse by the water. In the even that the coil spring or slinky  3   d  is outside, the connecting means should be strong to prevent the second conduit from collapsing. 
     In  FIGS. 4 ,  5 ,  7 ,  8 ,  10   a    11 , and  12 , the float  3   c  is shown as being a half of a torus in cross-section and submerged in water. Of course, the cross-section of the float can be varied to take other shapes such as a complete torus shape  300   a , a revolving triangular shape  300   b , a revolving square shape  300   c , a revolving trapezoidal shape  300   d , a revolving oval shape  300   e , or any other shape forming a closed wall with an axial opening extending through. 
       FIG. 5  shows an alternative collecting system  200  having no container  18 . Here, the pump  20  is directly connected to the drain  3  via a collecting conduit  22 , which is connected to a flexible sleeve  17 . The flexible sleeve  17  is then connected to the first conduit  3   a  via any connecting means. It should be distinguished that the drain in system  200  contains a structural support in the drain  3  for preventing the second conduit  3   b  from collapsing while the system  100 , shown in  FIG. 4 , the drain  30  has no structural support on the second conduit. The drains  40  and  60 , respectively shown in  FIGS. 11 and 12 , contains an external flange  51  in the second conduit  40   b  and the first conduit, respectively  60   a , while an internal flange  52  is in the first conduit  40   a  and the second conduit  60   b  respectively. These internal flanges  52  and external flanges  51  are utilized to keep the seal  50  between the first conduit and the second conduit. It is contemplated that the first conduit  40   a ,  60   a  and the second conduit  40   a ,  60   b , are made from flexible material or plastic or similar to the other conduits as shown in  FIGS. 4 ,  8 , and  9 . In all embodiments, the first conduit  3   a ,  40   a ,  60   a , can be made from flexible material or a rigid material. 
       FIGS. 1-5  shows the catchment  1  with a channel  1   f , which has a closed back wall. While the channel  1   f  has been show being u-shaped, the channel  1   f  can have any other channel shape such as being round, hexagonal, or with a different curve pattern. Further, while the channel  1   f  shown in  FIG. 1-5  is closed on its back, the channel  1   f  can be opened as implemented in catchment  10  in  FIG. 13 . Here, the channel  10   f  has a back opening  10   i  delimited by two cross braces  10   h  to give structural strength and allow the bracket  16  to be mounted on one of the two braces  10   h.    
     While the design requirement of the float is to keep the top surface of the float  3   c  above water or sandwiched between the oil and the water, the best material to use is a wax material such as paraffin. Wax generally has a specific gravity of 0.93-0.96 while paraffin is 0.95. Oil has a specific gravity of approximately 0.9. The other design consideration is to keep the float sunken in water such that 51%-99% of its volume is under water. Of course, the drain could be made of Styrofoam as a hollow tube properly bottom weighted with ballast to have a net specific gravity in the proper range of the fluids being separated. 
     While the drain  3  in  FIG. 8  has been shown to appear stationary, the drain  3  is to be moving with the catchment  1 . The drain  3  is not limited to be moving in direction d in open waters. The drain  3  can be utilized by itself in a stationery fashion. The system  100 ,  200  could be used with tugboats such that one pulls on the containment  1  in open waters or pushes on the containment  1 . Alternatively, the system can be integrated with a boat, ship, barge, or be self-propelled. For instance, the container  18  can be part of the boat, ship, or barge. It is contemplated that the sizes of the features can be varied to fit any condition. While the second conduit  3   b  is to be made of flexible material or cloth, there&#39;s no limited restriction as to the flexible material or cloth used. These materials can vary from latex, rubber, or synthetic fibers. Further, while water cannot be completely avoided in the container  18 , a separate pump can be implemented to the container  18  in case any water has been collected. The pump  20 , although being shown sitting on top of the container  18  in  FIG. 4 , the container can be in any location or be located in a tugboat, ship, barge, or any naval vessel. 
     It is contemplated that the term water is not be limited to salt water but can be fresh or brackish water, each with a higher specific gravity than oil. While the invention is contemplated to solve oil spills the invention can function on the oceans of Saturn moons or Jupiter moons where one could be dealing with the specific gravity of liquid methane or other organic compounds, and another substance.