Abstract:
A contaminant recovery system for recovering contaminant in a contaminated area. The contaminant recovery system includes (i) a buffer configured to heat wax and thereby create molten wax, and (ii) a sprayer configured to spray the molten wax onto the contaminant within the contaminated area. The system further includes (i) a first line configured to deliver the molten wax from the buffer to the sprayer, and (ii) a second line configured to return the molten wax from the sprayer to the buffer in response to the sprayer being deactivated. The second line is separate from the first line.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure describes techniques and systems for contaminant recovery. 
       BACKGROUND 
       [0002]    Contaminant recovery is the process of recovering a contaminant that has spilled onto water or land. For example, contaminant recovery is typically required in cases of a marine oil spill, in which oil is released into a body of water—e.g, the ocean, coastal waters, lakes, reservoirs, or streams. Oil spills can occur due to releases of crude oil from tankers, offshore platforms, drilling rigs and wells, as well as spills of refined petroleum products (such as gasoline, diesel) and their by-products, and heavier fuels used by large ships such as bunker fuel, or the spill of any oily refuse or waste oil. 
         [0003]    Contaminant recovery can also include removal of a contaminant from a container—e.g., a storage drum. For example, chemical storage companies typically store waste oil in storage drums, and such storage drums generally have a pre-determined lifetime associated with safe storage of waste oil. Once a storage drum is no longer fit to store waste oil, the waste oil is typically transferred into a newer storage drum and any residual waste oil remaining within the storage drum typically needs to be recovered for safe disposal of the storage drum. 
       SUMMARY 
       [0004]    In general, in one aspect, this specification describes a contaminant recovery system. The contaminant recovery system includes a buffer configured to heat wax and thereby create molten wax, and a sprayer configured to spray the molten wax onto the contaminant within the contaminated area. The contaminant recovery system further includes a first line a second line, each coupled between the buffer and the sprayer. The first line is configured to deliver the molten wax from the buffer to the sprayer, and the second line is configured to return the molten wax from the sprayer to the buffer in response to the sprayer being deactivated. The second line is separate from the first line. 
         [0005]    Implementations can include one or more of the following features. The contaminated area can be located on a surface of water, and the sprayer can include a plurality of spray nozzles configured to spray the molten wax onto the surface of the water. A first spray nozzle of the plurality of spray nozzles can be directed to spray the molten wax towards the surface of the water from above the surface of the water. A second spray nozzle of the plurality of spray nozzles can be directed to spray the molten wax towards the surface of the water from below the surface of the water. The first spray nozzle can be positioned substantially opposite to the second spray nozzle. 
         [0006]    The molten wax can solidify on the surface of the water and encapsulate the contaminant in the contaminated area, and the contaminant recovery system can further include a collector configured to collect the solidified wax containing the contaminant therein from the surface of the water. The contaminant recovery system can further include a collector and/or a separator. The separator can be configured to separate the contaminant from the solidified wax. The storage can be configured to store the contaminant removed from the solidified wax. 
         [0007]    The contaminated area can be located on a surface of land, and the sprayer can include a spray nozzle configured to spray the molten wax onto the surface of the land. The contaminant recovery system can be hand-held. The sprayer can comprise a wand. The wand can have an adjustable length to permit an operator to direct the molten wax over a large portion of the contaminated area while the operator substantially remains at a same location. The contaminant recovery system can be implemented on a vessel. The vessel can comprise one or more of a yacht, a pontoon boat, a vehicle, or a trailer. The contaminated area can be located on an inner wall of a storage drum, and the sprayer can include a spray nozzle configured to spray the molten wax onto a surface of the inner wall of the storage drum. 
         [0008]    In general, in another aspect, this specification describes a method for recovering contaminant in a contaminated area. The method includes using a buffer to heat wax and thereby create molten wax; and using a sprayer to spray the molten wax onto the contaminant within the contaminated area. The molten wax is delivered from the buffer to the sprayer over a first line coupled between the buffer and the sprayer. In response to the sprayer being deactivated, the molten wax is returned from the sprayer to the buffer over a second line coupled between the buffer and the sprayer, in which the second line is separate from the first line. 
         [0009]    The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description and drawings, and from the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a block diagram of an example contaminant recovery system. 
           [0011]      FIG. 2A  illustrates one implementation of a sprayer for use with a contaminant recovery system. 
           [0012]      FIG. 2B  illustrates an example positioning of spray nozzles along the sprayer of  FIG. 2A . 
           [0013]      FIG. 2C  illustrates one implementation of a system to support the sprayer shown in  FIG. 2A . 
           [0014]      FIG. 2D  illustrates another implementation of a sprayer for use with a contaminant recovery system. 
           [0015]      FIG. 3  is a block diagram of a hand-held contaminant recovery system including a sprayer. 
           [0016]      FIG. 4A  illustrates one implementation of the sprayer in  FIG. 3 . 
           [0017]      FIG. 4B  illustrates another implementation of the sprayer in  FIG. 3 . 
           [0018]      FIG. 5  illustrates an example method for recovering a contaminant. 
           [0019]      FIG. 6  is a block diagram of a vessel including a contaminant recovery system. 
       
    
    
       [0020]    Like reference symbols in the various drawings indicate like elements. 
       DETAILED DESCRIPTION 
       [0021]      FIG. 1  illustrates one implementation of a contaminant recovery system  100 . The contaminant recovery system  100  includes a buffer  102 , a sprayer  104 , a collector  106 , a separator  108 , and a storage  110 . In one implementation, the contaminant recovery system  100  implements use of a wax to collect a contaminant. In such an implementation, the buffer  102  heats (and melts) the wax and pumps the molten wax to the sprayer  104 . The sprayer  104 , in turn, sprays the molten wax onto a contaminated area. As the sprayed wax cools and solidifies, the wax encapsulates the contaminant within the contaminated area. The collector  106  collects the solidified wax containing the contaminant, and provides the collected wax to the separator  108 . A take-up system as described in U.S. Patent Application Publication No. 2009/0057217, which is incorporated herein by reference in its entirety, can be used to collect solidified wax. The separator  108  separates the contaminant from the collected wax, and stores the contaminant within the storage  110 . In one implementation, the separator  108  also returns the wax (having the contaminant removed therefrom) back to the buffer  102  for subsequent reuse. 
         [0022]    In one implementation, the sprayer  104  includes both (i) a main line (first line) that provides molten wax to one or more spray nozzles of the sprayer  104 , and (ii) a return line (second line) that returns the molten wax to the buffer  102  for reuse—e.g., in the event that the spray nozzle(s) are closed (or shut off). In one implementation, the main line is separate from the return line. Unlike conventional sprayers that typically do not have a return line, any molten wax that remains in the main line during a time that the spray nozzles are closed can be returned back to the buffer  102 . Accordingly, the molten wax does not have an opportunity to solidify within the main line and potentially clog the main line. In one implementation, the sprayer  104  includes one or more sensors (not shown) which can detect contaminate located on the surface of the water and automatically activate spray of wax from a given spray nozzle. 
         [0023]    The contaminant recovery system  100  can further optionally include a radiator  112 . The radiator  112  provides coolant to the buffer  102  as well as any other components of the contaminant recovery system  100  (e.g., the collector  106 , the separator  108 , and so on) to aid in cooling such components during use of the contaminant recovery system  100  on land or on water. 
         [0024]      FIG. 2A  illustrates one implementation of a sprayer  200  for use in recovering a contaminant located on the surface of water. The sprayer  200  includes (i) a main line  202  that receives molten wax from a buffer  208 , and (ii) a plurality of spray nozzles  204  to spray the molten wax towards the surface of the water. The plurality of spray nozzles  204  can be arranged in rows, in which each row is staggered relative to an adjacent row as shown in  FIG. 2B . In general, the plurality of spray nozzles can be positioned in a different manner to provide sufficient coverage of wax onto the surface of the water. 
         [0025]    Referring back to  FIG. 2A , each spray nozzle located above the surface of the water has a corresponding spray nozzle substantially located opposite to the spray nozzle underneath the surface of the water. The oppositely positioned spray nozzles (i.e., upper spray nozzle and lower spray nozzle) are positioned such that at least a portion of a spray area of the upper spray nozzle overlaps at least a portion of a spray area of the lower spray nozzle. Such positioning of spray nozzles aids in improving the encapsulation (or sandwiching) of a contaminant within the sprayed wax as the wax solidifies. 
         [0026]    In order to prevent the main line  202  from being clogged with solidified wax in the event that the spray nozzles  204  are shut off, in one implementation, the sprayer  200  further includes return lines  206  to return the molten wax in the main line  202  back to the buffer  208 . The main line  202  and/or the return lines  206  can be heated to maintain a molten state of the wax. In one implementation, only the portions of the main line  202  and the return line  206  located underneath the surface of the water are heated, while the portions of the main line  202  and the return line  206  located above the surface of the water are not heated. 
         [0027]    The sprayer  200  can be either rigidly fixed or loosely coupled to the buffer  208 . Referring to  FIG. 2C , in one implementation, the sprayer  200  is coupled to one or more buoys  210  so that the spray nozzles of the sprayer  200  can substantially maintain a fixed distance relative to the surface of the water. In this implementation, the sprayer  200  can be coupled to the buffer  208  via a flexible, heated hot melt high pressure hose. The flexible, high pressure hose permits the sprayer  200  to float on the surface of the water separately from a vessel that contains the remaining components of the contaminant recovery system. 
         [0028]      FIG. 2D  illustrates one implementation of a sprayer  212  for use in recovering a contaminant located on the surface of land. The sprayer  212  includes (i) a main line  214  that receives molten wax from a buffer  220 , and (ii) a plurality of spray nozzles  216  to spray the molten wax towards the surface of the land. The sprayer nozzles  216  can be positioned in one or more rows, in which each row is staggered relative to an adjacent row. In general, the spray nozzles  216  can be positioned in any manner to provide a sufficient spray area to cover a contaminated area. In one implementation, the sprayer  212  further includes a return line  218  to return the molten wax in the main line  214  back to the buffer  220 . The main line  214  and/or the return lines  216  can be heated to maintain a molten state of the wax. 
         [0029]      FIG. 3  illustrates one implementation of a hand-held contaminant recovery system  300 . The contaminant recovery system  300  includes a buffer  302  and a sprayer  304 . In one implementation, the contaminant recovery system  300  implements use of a wax to collect a contaminant. In such an implementation, the buffer  302  heats (and melts) the wax and pumps the molten wax to the sprayer  304 . The sprayer  304 , in turn, can be manually positioned or aimed to spray the molten wax onto a contaminated area. As the sprayed wax solidifies, the wax encapsulates contaminate within the wax, and the wax (containing the contaminant) can be recovered using any conventional techniques. In one implementation, the sprayer  304  is coupled to the buffer  302  via a flexible, heated high pressure hose. 
         [0030]      FIG. 4A  illustrates one implementation of a sprayer  400  that can be used with a hand-held contaminant recovery system (e.g., hand-held contaminant recovery system  300 ) to disperse molten wax onto a contaminated area. The sprayer  400  can be manually held by an operator, and includes one or more spray nozzles  410  that can be aimed by the operator towards a contaminated area. In one implementation, a flexible, heated hose  402  delivers molten wax to the sprayer  400 . The flexible, heated hose  402  can be removably detachable from a fitting  404  located on the sprayer  400 . In one implementation, the sprayer  400  further includes a fitting  408  to which a return line  406  can be attached. The return line  406  permits molten wax within the flexible hose  402  to return to a buffer (e.g., buffer  302 ) in the event that the sprayer  400  is not activated. 
         [0031]      FIG. 4B  illustrates one implementation of a sprayer  412  that can be used with a hand-held contaminant recovery system (e.g., hand-held contaminant recovery system  300 ) to disperse molten wax onto a contaminated area. In one implementation, the sprayer  412  is a heated wand available from Ocean Cleaning Consultant, Inc. of Oakland, Calif. The sprayer  412  can be manually held by an operator to disperse molten wax onto a contaminated area. In one implementation, the sprayer  412  includes a plurality of spray nozzles  414  to disperse molten wax over a relatively large area. In one implementation, the sprayer  412  further includes a handle  420  to permit an operator to more easily direct the spray of the molten wax towards a desired direction. The sprayer  412  can also have a length that is adjustable to permit an operator to direct spray at areas that may be unreachable with a hand-held sprayer such as sprayer  400  of  FIG. 4A . In one implementation, the adjustable length of the sprayer  412  permits an operator to direct the molten wax over a large portion of a contaminated area while the operator substantially remains at a same location. 
         [0032]    In one implementation, a flexible, heated hose  416  delivers molten wax to the sprayer  412 . The flexible, heated hose  416  can be removably detachable from a fitting  416  located on the sprayer  412 . In one implementation, the sprayer  412  further includes a fitting  418  to which a return line  418  can be attached. The return line  418  permits molten wax within the flexible hose  416  to return to a buffer (e.g., buffer  302 ) in the event that the sprayer  412  is not activated. 
         [0033]    A hand-held contamination recovery system (e.g., hand-held contamination recovery system  300 ) is particularly useful in removing contaminant from large storage drums. Sprayers such as sprayer  400  and sprayer  412  permit molten wax to be sprayed along an inner surface of a storage drum. In some cases, storage drums are deeply embedded into the earth and require exhumation for proper disposal. In most cases, the inner walls of such storage drums typically experience corrosion and, therefore, may be in a weakened state—thus, making removal of storage drums from the earth a difficult process. By spraying the inner walls of a storage drum with molten wax, as the wax solidifies the wax not only encapsulates any contaminant that may be deposited on the inner walls, the solidifying wax also adds structural stiffness to the inner walls to permit the storage drum to be removed wholly from the earth without breaking up into pieces. Additionally, the solidified wax prevents small, corrosive chippings from falling away from the inner walls of the storage drum as the storage drum is transported for disposal. 
         [0034]      FIG. 5  illustrates a method  500  for recovering a contaminant in accordance with one implementation. Wax is heated (step  502 ). In one implementation, wax is heated using a buffer (e.g., buffer  102 ). In one implementation, the buffer comprises a hot melt unit to heat wax into a liquid form. The molten wax is sprayed onto a contaminated area (step  504 ). A sprayer (e.g., sprayer  104 ) can be used to spray the molten wax. In general, molten wax can be sprayed onto a contaminated area located on water or land. As the wax cools and solidifies, the wax encapsulates contaminant within the wax. The sprayed wax is collected (step  508 ). In one implementation, a collector (e.g., collector  106 ) can be implemented to collect the wax having the contaminant encapsulated therein. Alternatively, the wax can be collected by hand, suction hose, or by other recovery means. The contaminant is separated from the wax (step  508 ). In one implementation, a separator (e.g., separator  108 ) is implemented to separate the contaminant from the wax. Thereafter, the wax can be provided to the buffer for re-melt and reapplication onto the contaminated area. 
         [0035]      FIG. 6  illustrates one implementation of a vessel  600  including a contaminant recovery system  602 . The contaminant recovery system  602  can be a contaminant recovery system as described above (e.g., contaminant recovery system  100 ). In general, the vessel  600  can be a land-based vessel and/or a water-based vessel. The vessel  600  can be any vessel as described in U.S. Patent Application Publication No. 2009/0057217—e.g., a catamaran, a vehicle, a lightweight pontoon craft, and so on. Additionally, the vessel  600  can be a towable trailer that can be disconnected from a tow vehicle. 
         [0036]    Various implementations for recovering contaminant using a contaminant recovery system have been described. Nevertheless, various modifications may be made to the implementations. For example, though the techniques described above refer to use of wax to recover a contaminant, the techniques are applicable to other types of elements or materials that can be sprayed to encapsulate a contaminant. Accordingly, many modifications may be made without departing from the scope of the following claims.