Autonomous In-Water Marine Antifouling Apparatus, System and Method

Abstract

The present disclosure is addressed to apparatus, systems and methods for use in seawater environments for the in-water, ablation and removal of marine organisms, including marine microorganisms, that attach to the hull of ship. The marine antifouling system of the present disclosure employs one or more biofouling ablation vehicles to repeatedly traverse the hull of a ship below the water line to ablate marine organisms and microorganisms on a recurring basis. Each biofouling ablation vehicle may incorporate a rechargeable battery or may be connected to an external source of electrical power though a reinforced tether that enables the ablation of marine biofouling to be performed in an automated and recurring manner following pre-programmed and/or machine learning enabled paths that, collectively, cover the exposed surfaces of the hull of a ship below the water line.

We claim: 
     
         1 . An apparatus for the molecular dissociation and removal of marine organisms ( 21 ) attached to a surface on an antifouling coating ( 25 ) adhered to a hull ( 11 ) of a ship ( 9 ) in sea water ( 19 ), comprising:
 a plurality of active electrodes ( 55 ) confronting adjacency with marine organisms ( 21 ) attached to the surface of the antifouling coating ( 25 ) adhered to the hull ( 11 ) of a ship ( 9 );   one or more common electrodes ( 92 ) in electrical communication with the plurality of adjacent active electrodes ( 55 ) through surrounding sea water ( 19 ); and,   a power supply ( 42 ) incorporating a radiofrequency generator ( 95 ), a first active electrode lead ( 97 ) in series electrical communication between the radiofrequency generator ( 95 ) and each current limiting inductor ( 108 ) or current limiting circuitry incorporating inductors and capacitors and a second electrical lead ( 112 ) in electrical communication between each current limiting inductor ( 108 ) or current limiting circuitry incorporating inductors and capacitors and each active electrode within the plurality of active electrodes ( 55 );   wherein the apparatus generates a vapor layer ( 58 ) in the region of high electric field intensity ( 91 ) between the distal end face ( 71 ) of each active electrode ( 55 ) and the marine organisms ( 21 ) attached to the surface of the antifouling coating adhered to the hull of the ship.   
     
     
         2 . The apparatus of  claim 1 , wherein the active electrode ( 55 ) comprises tungsten or an alloy containing tungsten. 
     
     
         3 . The apparatus of  claim 1 , wherein the common electrode ( 92 ) comprises Hastelloy C-276 steel Type 316, Monel or Alloy 400, titanium or a titanium alloy. 
     
     
         4 . The apparatus of  claim 1 , wherein the radiofrequency generator ( 95 ) applies a voltage between each active electrode ( 55 ) and common electrode ( 92 ) having a frequency of 50 to 500 kHz. 
     
     
         5 . The apparatus of  claim 1 , wherein the radiofrequency generator ( 95 ) applies a voltage between each active electrode ( 55 ) and common electrode ( 92 ) of 200 to 2000 volts (peak to peak). 
     
     
         6 . The apparatus of  claim 1 , further comprising a removably attachable active electrode module ( 46 ), wherein the removably attachable active electrode module ( 46 ) houses the plurality of active electrodes ( 55 ) and the common electrode ( 92 ). 
     
     
         7 . The apparatus of  claim 6 , wherein the removable attachable active electrode module ( 46 ) is in electrical communication with an interconnection terminal array module ( 72 ). 
     
     
         8 . The apparatus of  claim 7 , further comprising one or more ablation module assemblies ( 102 ) which comprise two or more removably attachable active electrode modules ( 46 ). 
     
     
         9 . The apparatus of  claim 8 , further comprising an array of ablation module assemblies ( 103 ) which comprise two or more ablation module assemblies ( 102 ). 
     
     
         10 . The apparatus of  claim 9 , wherein the power supply ( 42 ) incorporates a multiplexer ( 110 ) to selectively apply power from the radiofrequency generator ( 95 ) to any one of the ablation module assemblies ( 102 ) within the array of ablation module assemblies ( 103 ). 
     
     
         11 . The apparatus of  claim 1 , wherein the total combined surface area of the common electrodes ( 92 ) in contact with sea water is substantially greater than the total combined surface area of all of the active electrodes ( 55 ) in contact with sea water. 
     
     
         12 . The apparatus of  claim 1 , wherein power supply ( 42 ) incorporates an independent feedback-controlled voltage source within power supply ( 42 ) that adjusts the applied voltage in correspondence to an electrical impedance in a circuit comprising a current path between each active electrode ( 55 ) and the common electrode ( 92 ). 
     
     
         13 . A system for the molecular dissociation and removal of marine organisms ( 21 ) attached to a surface on an antifouling coating ( 25 ) adhered to a hull ( 11 ) of a ship ( 9 ) in sea water ( 19 ), comprising:
 one or more biofouling ablation vehicles ( 12  or  212 ) comprising a power supply ( 42 ), a control and communication system ( 44 ), a back-up battery ( 41 ), a battery management system ( 45 ), four drive wheels ( 22 ) actuated by hub motors ( 28 ) that drive two or more traction belts ( 24 ) incorporating a plurality of permanent magnets ( 26 ), and a support frame ( 106 ) comprising an array of ablation module assemblies ( 103 ), wherein the array of ablation module assemblies ( 103 ) comprise two or more ablation module assemblies ( 102 ), wherein the ablation module assemblies ( 102 ) comprise two or more removably attachable active electrode modules ( 46 ), wherein the removably attachable active electrode modules ( 46 ) are removably attached to a corresponding interconnection terminal array module ( 72 );   a tether ( 8 ) supplying electrical power to each biofouling ablation vehicle ( 12  or  212 ) that also incorporates a fiber optic cable ( 254 ) for transmission of video signals from a plurality of digital image sensors ( 130  and  136 ) on a bottom facing surface ( 122 ) of the biofouling ablation vehicle ( 12  or  212 );   one or more biofouling ablation vehicle maintenance stations ( 13  or  213 ) incorporating a forced-convection heating unit ( 57 ) and a cleaning water pressurization and control unit ( 56 ) to heat an exterior of the biofouling ablation vehicle ( 12  or  212 ) and remove marine organisms from its surface; and,   a command and control center ( 6 ) located on ship ( 9 ) for receiving video signal transmissions from the plurality of digital image sensors ( 130  and  136 ) and for transmitting wireless communications to both the biofouling ablation vehicle ( 12  or  212 ) and the biofouling ablation vehicle maintenance station ( 13  or  213 ).   
     
     
         14 . The system of  claim 13 , wherein the biofouling ablation vehicle maintenance station ( 13  or  213 ) comprises a remotely operable door to allow the biofouling ablation vehicle ( 12  or  212 ) entrance into and exit from the biofouling ablation vehicle maintenance station ( 13  or  213 ), and
 wherein the remotely operable door ( 16 ) is closed during a period of forced air heating convection, wherein during the period of force air heating convection within the biofouling ablation vehicle maintenance station ( 13  or  213 ), the exterior of the biofouling ablation vehicle ( 12  or  212 ) is heated to at least 72° C. for the purpose of removing marine organisms from the exterior of the biofouling ablation vehicle ( 12  or  212 ). 
 
     
     
         15 . The system of  claim 13 , wherein the biofouling ablation vehicle ( 12  or  212 ) comprises a biofouling ablation vehicle enclosure ( 14  or  214 ), wherein the biofouling ablation vehicle enclosure ( 14  or  214 ) comprises a door ( 27 ) positioned a bottom surface of the biofouling ablation vehicle enclosure ( 14  or  214 ), wherein the door ( 27 ) provides access to a bottom surface of the support frame ( 106 ) to allow access to and replacement of the removably attachable active electrode modules ( 46 ). 
     
     
         16 . The system of  claim 15 , wherein the permanent magnets ( 26 ) are housed within a first traction belt and a second traction belt between slots ( 51 ) integrated within the first traction belt and the second traction belt, and
 wherein the door ( 27 ) comprises a width that is less than a width between inner edges of a first traction belt and a second traction belt to allow the door ( 27 ) to be opened without having to overcome attraction forces from the magnets ( 26 ) incorporated within the first traction belt and the second traction belt.   
     
     
         17 . The system of  claim 13 , wherein the tether ( 8 ) comprises a buoyancy filler ( 256 ) and is positioned at a front end ( 35 ) of a biofouling ablation vehicle enclosure ( 15 ) and is in electrical communication with an AC to DC converter ( 38 ), wherein the AC to DC converter ( 38 ) is in electrical communication with backup battery ( 41 ), battery management system ( 45 ), power supply ( 42 ) and control and communication system ( 44  or  244 ). 
     
     
         18 . The system of  claim 13 , wherein the biofouling ablation vehicle ( 12  or  212 ) comprises a biofouling ablation vehicle enclosure ( 14  or  214 ), wherein an air gap or an insulative material thickness of at least 0.25 inch is maintained between an inner surface of the biofouling ablation vehicle enclosure ( 14  or  214 ) and the battery ( 40 ), battery management system ( 45 ), power supply ( 42 ) and the control and communication system ( 44 ) of the biofouling ablation vehicle ( 12 ) to ensure that the battery ( 40 ), battery management system ( 45 ), power supply ( 42 ) and the control and communication system ( 44 ) are maintained at acceptably low temperatures to prevent thermal damage of the battery ( 40 ), battery management system ( 45 ), power supply ( 42 ) and the control and communication system ( 44 ) during forced air heating convection of the biofouling ablation vehicle ( 12  or  212 ). 
     
     
         19 . A method for the molecular dissociation and removal of marine organisms ( 21 ) attached to a surface on an antifouling coating ( 25 ) adhered to a hull ( 11 ) of a ship ( 9 ) in sea water ( 19 ), comprising the steps of:
 a) selecting a biofouling ablation vehicle ( 12  or  212 ) to be activated for use in repetitive molecular dissociation and removal of marine organisms ( 21 ) attached to a surface on the antifouling coating ( 25 ) adhered to the hull ( 11 ) of the ship ( 9 ) in sea water ( 19 );   b) charging back-up battery ( 41 ) and activating a control and communication system ( 44 );   c) entering topographical map data into the control and communication system ( 44 ) corresponding to a specific portion of the hull ( 11 ) of the ship ( 9 ) where molecular dissociation and removal of marine organisms ( 21 ) attached to a surface on the antifouling coating ( 25 ) adhered to the hull ( 11 ) of the ship ( 9 ) is being repetitively performed;   d) inserting a removably attachable active electrode module ( 46 ) into an interconnection terminal array module ( 72 ) incorporated in an ablation module assembly ( 102 ) within an array of ablation module assemblies ( 103 );   e) positioning the selected biofouling ablation vehicle ( 12  or  212 ) on the hull ( 11 ) of the ship ( 9 ) and attaching a reinforced power and communication tether ( 8 ) to the biofouling ablation vehicle ( 12  or  212 );   f) inputting a command to the control and communication system ( 44 ) that activates the biofouling ablation vehicle ( 12  or  212 ) to proceed to the biofouling ablation vehicle maintenance station ( 13  or  213 ) located on or adjacent to the hull ( 11 ) of the ship ( 9 );   g) setting timers for each ablation module assembly ( 102 ) to zero wherein timers are used for monitoring the activation time for each ablation module assembly ( 102 ) thereby determining when each ablation module assembly ( 102 ) has reached the pre-determined end of its useful life;   h) inputting a command to the biofouling ablation vehicle ( 12  or  212 ) that activates the biofouling ablation vehicle ( 12  or  212 ) to proceed to its pre-programmed starting location to commence the molecular dissociation and removal of marine organisms ( 21 ) attached to a surface on the antifouling coating ( 25 ) adhered to the hull ( 11 ) of a ship ( 9 ) along the entire sequence of pre-programmed path on hull of ship;   i) continuing to compare the activation time for each ablation module assembly ( 102 ) within the array of ablation module assemblies ( 103 ) with its predetermined maximum allowed activation time;   j) re-directing the application of power using the multiplexer ( 110 ) within the power supply ( 42 ) from an ablation module assembly ( 102 ) that has reached its maximum allowed activation time to the next available unused ablation module assembly ( 102 ) within the array of ablation module assemblies ( 103 );   k) continuing the molecular dissociation and removal of marine organisms ( 21 ) attached to a surface on the antifouling coating ( 25 ) adhered to the hull ( 11 ) of the ship ( 9 ) along the entire sequence of a pre-programmed path on the hull ( 11 ) of the ship ( 9 ) until all ablation module assemblies ( 102 ) have reached their predetermined maximum allowed activation time;   l) inputting a command to activate the biofouling ablation vehicle ( 12  or  212 ) to return to the biofouling ablation vehicle maintenance station ( 13  or  213 ) after all ablation module assemblies ( 102 ) have reached their predetermined maximum allowed activation time;   m) removing all removably attachable active electrode modules ( 46 ) from all ablation module assemblies ( 102 ) within the array of ablation module assemblies ( 103 ) whose activation times have reached their maximum allowed activation time and replace the removably attachable active electrode modules ( 46 ) with new unused removably attachable active electrode modules ( 46 ); and,   n) repeating steps (g) through (m) until the molecular dissociation and removal of marine organisms ( 21 ) attached to the surface on the antifouling coating ( 25 ) adhered to the hull ( 11 ) of the ship ( 9 ) along all pre-programmed paths have been completed.   
     
     
         20 . The method of  claim 19 , further comprising the steps of:
 illuminating the hull ( 11 ) of the ship ( 9 ) by light sources ( 132  and  138 );   acquiring optical images of the hull ( 11 ) of the ship ( 9 ) by a plurality of digital image sensors ( 130  and  136 ) attached to the biofouling ablation vehicle ( 12  or  212 );   transmitting video signals from the digital image sensors ( 130  and  136 ) through the tether ( 8 ) to a command and control center ( 6 ) through a fiber optic and/or data cable ( 254 );   acquiring optical images from the transmitted video signals to observe a level of marine organisms ( 21 ) attached to an antifouling coating ( 25 ) on the hull ( 11 ) of the ship ( 9 );   running an image-processing software to digitally determine an extent of completeness of removal of marine organisms ( 21 ) by the biofouling ablation vehicle ( 12  or  212 ); and,   adjusting a speed of advancement of the biofouling ablation vehicle ( 12  or  212 ) and/or a level of voltage, V 1  applied by a radiofrequency generator ( 95 ) to the ablation module assembly ( 102 ) based on the extent of completeness of removal of marine organisms ( 21 ) by the biofouling ablation vehicle ( 12  or  212 ) determined by the software to adjust a rate of molecular dissociation of the marine organisms ( 21 ) attached to the antifouling coating adhered to the hull ( 11 ) of the ship ( 9 ).