Abstract:
A dredging system agitates the bottom sediment of a waterway to remove particles and oxygenate the water. The system diffuses air through a grid mounted on a waterway floor, raising particle clouds. The particle clouds are transported downstream by water currents while releasing dissolved oxygen throughout the water column. The method of particle removal and oxygenation is used in shallow depths, less than thirty-three feet (2 bars) with minimum favorable water currents of one-half to one knot. The grid is used for diffusion of air to alleviate hypoxic environments in depths less than sixty-six feet (5 bars).

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     REFERENCES CITED 
     The following are examples of prior art that were found to be relevant to this invention. 
     The USPTO parent classification 37 was found to be the most relevant to the invention. The patents are listed below in approximate order of importance. 
     The core of the invention appears to be a system that agitates the bottom sediment of a waterway using compressed air pumped through a grid placed on the bottom of the waterway, causing the particles of sediment to be suspended in the water column where they can be carried away by favorable currents. 
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
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                 Antill, Sr. 
               
               
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                 Taplin 
               
               
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                 Langejan 
               
               
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     Dak Steiert, Intelligent Patent Services, Palo Alto, Calif. 
     DESCRIPTION 
     Background of the Invention 
     The present invention is in the technical field of dredging. More particularly, the present invention is in the technical field of air-suspended particle removal by a sea floor-mounted grid. 
     Conventional air-suspended particle removal dredges, such as air-lift suction dredges, cutter-suction dredges with air injection, jet-lift dredges and air-lift dredges remove large quantities of material by creating a slurry and pumping the slurry into a hopper or onto a spoil area. The difficulties of these devices are their size and in their initial and operating expenses. The size and complexity of dredging machinery makes these methods of dredging out of reach of the general public. The expense of operating these dredges is beyond the reach of individuals and small businesses. 
     A second method of particle suspension, the water injection or agitation dredge, creates a particle slurry with water jets and allows currents to carry the slurry to another area. This dredging method is effective only so long as the induced particle slurry remains suspended in the water. Therefore, large amounts of water must be used to suspend the slurry, causing visual and ecological problems. 
     SUMMARY OF THE INVENTION 
     The sea floor-mounted air cloud dredge has a surface power source and instrumentation with a power connector running to an air compressor, storage tank and instrumentation, with a compressed air distribution line on which is installed air valves and gauges and an additive injection port. A tether line and current sensor conduit are fastened to the air distribution line which enters the water and runs to the air grid injection port entering the sea floor-mounted air grid. Attached to the air grid is a water current sensor and outrigger ballast struts. On the underside of the sea floor-mounted air grid are air nozzles for delivering compressed air to the target area. 
     The power source is a diesel engine or electric motor with sufficient power to operate the air compressor, producing a minimum 150 psig through a minimum 30 gallon storage tank according to signals from the current sensor. The air distribution line is of varying pipe size and length sufficient to deliver the required air from the air compressor through the valves and gauges installed on the air distribution line. The valves and gauges are sufficient to halt air flow, prevent backflow, and deliver air as measured psi. The additive injection port enables the addition of polymers and other additives to enhance air distribution efficiency. The tether line and current sensor conduit are attached to the air distribution line which enters the water and attaches to the air injection port allowing pressurized flow through the sea floor-mounted air grid. Air flow through the air grid commences when the current sensor signals the air compressor that minimum current speed is available. Fastened to the sea floor-mounted air grid are outrigger and ballast struts to offset flotation and to prevent grid burial. The air nozzles attached to the air grid are of sufficient size to deliver the compressed air a minimum of 6 inches below the nozzle openings. The nozzles are typically spaced 6 to 12 inches apart on the undersides of the sections of the air grid. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of an air cloud dredge of the present invention; 
         FIG. 2  is a top view of an air cloud dredge of the present invention 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the invention in more detail, in  FIG. 1  there is shown a sea floor-mounted air cloud dredge  10  having a surface power source and instrumentation  12  with a power connector  14  running to an air compressor, storage tank and instrumentation  16  with a compressed air distribution line  18  on which is installed air valve&#39;s and gauges  20  and an additive injection port  22 . A tether line and current sensor conduit  24  are fastened to the air distribution line  18  which enters the water and runs to the air grid injection port  26  entering the sea floor-mounted air grid  28 . Attached to the air grid  28  is a water current sensor  30  and outrigger ballast struts  32  and  34 . On the underside of the air grid  28  are air nozzles  36 ,  38 ,  40 ,  42 ,  44 , and  46 . 
     In further detail, still referring to the invention as shown in  FIG. 1 , the power source  12  is a diesel engine or electric motor with sufficient power to operate the air compressor  16 , producing a minimum 150 psig through a 30 gallon storage tank according to signals from the current sensor  30 . The air distribution line  18  is of varying pipe size and length sufficient to deliver the required air from the air compressor  16  through the valves and gauges  20  installed on the air distribution line  18 . The valves and gauges  20  are sufficient to halt air flow, prevent backflow, and deliver air as measured psi. The additive injection port  22  enables the addition of polymers and other additives to enhance air distribution efficiency. 
     In further detail, still referring to the invention as shown in  FIG. 1 , the tether line and current sensor conduit  24  are attached to the air distribution line  18  which enters the water and attaches to the air injection port  26  allowing pressurized flow through the sea floor-mounted air grid  28 . Air flow through the air grid commences when the current sensor  30  signals the air compressor  16  that minimum current speed is available. 
     In further detail, still referring to the invention as shown in  FIG. 1 , fastened to the sea floor-mounted air grid  28  are outrigger and ballast struts  32  and  34  to offset flotation and to prevent grid burial. The air nozzles  36 ,  38 ,  40 ,  42 ,  44 , and  46  attached to the air grid  28  are of sufficient size to deliver the compressed air a minimum of 6 inches below the nozzle openings. The nozzles  36 ,  38 ,  40 ,  42 ,  44 , and  46  are typically spaced 6 to 12 inches apart on the undersides of the sections of the air grid  28 . 
     The construction materials of the invention as shown in  FIG. 1  are that the sea floor-mounted air cloud dredge  10  may be made of various materials supplied by various manufacturers. The sections of the air grid  28  may be made of metal, HDPE, PVC, CPVC and other materials with a minimum 200 psi rating. The air distribution line  18  may be rigid and/or flexible with a minimum 250 psi rating. All other components of the sea floor-mounted air cloud dredge  10  exist as manufactured items and may be purchased according to the minimum requirements for the specific operation of the air cloud dredge  10 . Further, various components may be deleted from or added to the air cloud dredge  10  for specific operations. The additive injection port  22  may be deleted and the current sensor  28  may be substituted for a surface-mounted timer. 
     Referring now to  FIG. 2 , there is shown a sea floor-mounted air cloud dredge  50  having a surface power source and instrumentation  52  with a power connector  54  running to a surface air compressor, storage tank and instrumentation  56  with a compressed air distribution line  58  on which is installed air valves and gauges  60  and an additive injection port  62 . A tether line and current sensor conduit  64  are fastened to the air distribution line  58  which enters the water and runs to the air grid injection port  66  on the sea floor-mounted air grid section  86 . Attached to the air grid section  86  is a water current sensor  68 . 
     In further detail, still referring to  FIG. 2 , outrigger and ballast struts  70  and  72  are fastened to sections  78 ,  80 , and  82  of the sea floor-mounted air grid. Lifting devices  74  and  76  are fastened to the intersections of sections  80 ,  84 , and  86  and are spaced every 10 to 20 feet along the sea floor-mounted unit according to its size and weight. 
     The construction materials of the invention as shown in  FIG. 2  of the air cloud dredge  50  may be made of various materials supplied by various manufacturers. The sections  78 ,  80 ,  82 ,  84 , and  86  of the sea floor-mounted grid may be made of metal, HDPE, PVC, CPVC and other materials with a minimum 200 psi rating. The air distribution line  58  may be rigid and/or flexible with a minimum 250 psi rating. All other components of the air cloud dredge  50  exist as manufactured items and may be purchased according to the minimum requirements for the specific operation of the air cloud dredge  50 . Further, various components may be deleted from or added to the air cloud dredge  50  for specific operations. The additive injection port  62  may be deleted and the current sensor  68  may be substituted for a surface-mounted timer. 
     The advantages of the present invention include, without limitation, the position of its sea floor-mounted grid, its simplicity of design, its ease of fabrication and operation, and its low impact on the environment. The principles of design of the invention are position on the sea floor, air compression, particle suspension, and transport by natural or induced currents. All of the materials for the present invention may be easily purchased, and fabrication may be successful with a nominal skill set. The low environmental impact of the present invention is effected by its operation according to the availability of natural currents and its use of oxygen to cause particle suspension as well as to supply dissolved oxygen from the base of the water column. 
     In broad embodiment, the present invention is less impactive, easier to operate, more efficient, and less expensive than the typical dredges using cutter heads, air injection, suction piping, pressure pumping and spoil areas. It is a gentler process than typical dredging, allowing a less harmful impact on the environment. Further, the placement of its sea floor-mounted air grid allows maximum particle suspension as well as dissolved oxygen dispersal upward through the entire water column. 
     While the forgoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention as claimed