Abstract:
The aerator air distribution manifold has a central plenum disposed at the lower end of a concentric rigid downpipe or duct, and a radial array of diffuser tubes extending from the plenum. Since the aerators are buoyant, the aeration tubes are deployed at a constant, uniform depth below the surface of the water at all times, regardless of the water level. All of the aerator manifolds receive their air supply from a remotely disposed air source. The air source may be based on shore, or may be based upon a ship or other floating vessel. A flexible air supply line or hose extends from the air supply to each of the buoyant aerators, the hose being supported by one or more rigid columns or poles anchored into the bottom of the body of water in which the aerators are placed.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to liquid aeration systems, and more particularly to an aerator air distribution manifold that has a plurality of radially disposed diffuser pipes or tubes extending from a central plenum. 
     2. Description of the Related Art 
     The contamination of various bodies of water by various means is an increasingly serious problem worldwide. The most widespread contaminants may be organic materials that enter the water system due to pollution from human habitation, either directly or indirectly, e.g., pollution from farms and the like. Such pollution can affect inland fresh water supplies (lakes and rivers), and can also be carried to the sea by inland rivers and waterways or by direct discharge of sewage and/or other pollutants into the sea. Organic material in the sewage of treatment plants is another example of such pollution, although contained for processing. The biochemical processes that occur in water due to such organic pollution are known to decrease the oxygen content of the water, thereby reducing or even destroying fish and other aquatic life in the contaminated body of water. Even if some fish remain in the polluted water, they are almost certainly unfit for human consumption, if caught. 
     It is generally considered that the most effective means of eliminating such pollutants in contaminated water is by bacteriological processing, wherein bacteria process the contaminants to break them down into harmless organic materials. However, such bacteria are aerobic, i.e., they require oxygen for their metabolism. This is well known in the sewage treatment field, where water is commonly treated by aeration after solids are removed by settling or other means. Such aeration is generally accomplished by mechanical means, e.g., pumping the water up for dispensing into the air from spray booms and nozzles, or by forcing air through underwater pipes for the air to bubble up through the water. Such mechanical systems are relatively costly to operate and require relatively high energy and manpower costs. Even if such systems were less costly to operate, a huge drawback is that they cannot be readily transported to a pollution site for operation at that site. Rather, the water must be transported to the location of the aeration system, a process that is clearly unworkable on a very large scale and/or over very long distances. 
     Another consideration is the frequent need to position the air diffuser(s) at a constant depth below the surface of the water in which the aerator is installed in order to simplify pressure regulation of the airflow. This is not a significant problem in settling ponds and the like, but can be a significant problem in bodies of water wherein the level changes from time to time, as in reservoirs with controlled outlets and bodies of water influenced by tidal action. 
     Thus, an aerator air distribution manifold solving the aforementioned problems is desired. 
     SUMMARY OF THE INVENTION 
     The aerator air distribution manifold is used on at least one buoyant aerator for aerating a body of water. The air distribution manifold of each of the aerators comprises a central plenum disposed at the lower end of a concentric rigid downpipe or duct, and a radial array of diffuser tubes extending from the plenum. As the aerators are buoyant, the aeration tubes are deployed at a constant, uniform depth below the surface of the water at all times, regardless of the water level. All of the manifolds receive their air supply from a remotely disposed air source. The air source may be based on shore, or may be based upon a ship or other floating vessel. A flexible air supply line or hose extends from the air supply to each of the buoyant aerators. The hose is supported by one or more rigid columns or poles anchored into the bottom of the body of water in which the aerators are placed. 
     A first embodiment of the buoyant aerator has a toroidal float and a plurality of legs extending down from the periphery of the float. The air distribution manifold comprises a radial array of aeration tubes or nozzles affixed at the lower end of a down tube, pipe, or duct disposed between the legs and below the float. A second embodiment of the buoyant aerator is anchored to a non-buoyant, sunken base that is permanently placed upon the floor of a body of water. A plurality of substantially vertical guide columns extends upward from the base. The toroidal float is installed and captured between the guide columns. The float is free to float up and down along the guide columns as the water level changes. The down tube or pipe depends through the center of the toroidal float, and moves up and down between the guide columns as the float moves up and down. The air distribution manifold and its plurality of radial diffuser pipes extend from the lower end of the down tube. 
     As the float remains atop the water in both aerator embodiments, the radial array of aeration tubes remains at a constant depth below the surface, so that the air supply remains at a constant pressure with no need for variance. A plurality of such buoyant aerators may be placed in a body of water, all of the aerators receiving their air supply from a single remotely located source. 
     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 
         FIG. 1  is a detailed environmental perspective view of an aerator air distribution manifold according to the present invention, shown installed on a buoyant aerator having a plurality of support legs immovably affixed and depending from a toroidal float. 
         FIG. 2  is an environmental, perspective view of the aerator air distribution manifold according to the present invention installed upon a different buoyant aerator having a plurality of parallel support columns anchored to the bottom of the body of water, the toroidal float, air delivery duct, and air distribution manifold being buoyantly supported between the columns. 
         FIG. 3  is an environmental, perspective view of an array of buoyant aerators of different types, each of the aerators being equipped with an aerator air distribution manifold according to the present invention, further illustrating a remotely disposed air supply based on shore. 
         FIG. 4  is an environmental, perspective view of an array of buoyant aerators of different types, each of the aerators being equipped with an aerator air distribution manifold according to the present invention, further illustrating an air supply based upon a floating vessel. 
     
    
    
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The aerator air distribution manifold is installed upon various embodiments of buoyant aerators with remote air supplies. Different means are provided for securing the aerators to the floor of the body of water in which they are installed and different air supply sources are provided, but all of the embodiments make use of the same air distribution manifold configuration. 
       FIG. 1  of the drawings provides a perspective view of a first buoyant aerator  10 . This aerator comprises a buoyant toroidal float  12  having a periphery  14  and a plurality of leg attachment points or fittings  16  installed thereon. Corresponding rigid support legs  18  extend from the fittings. Each leg has a support pad or foot  20  at the base thereof. Corresponding anchor cables or lines  22  extend from the leg attachment points  16 . The distal ends  24  of the cables  22  are anchored into the floor F of the body of water W to prevent the aerator  10  from drifting from its installed position. Each of the legs  18  has a fixed length, so that the support pads  20  remain clear of the floor F of the body of water W when the water depth is greater than the vertical lengths of the legs  18 . If the water depth becomes less than the vertical lengths of the legs  18 , e.g., due to tidal action, change in level in a reservoir, etc., the support pads  20  rest upon the floor F of the body of water W to support the aerator structure at a predetermined height above the floor F to preclude its contamination with mud or other bottom debris. 
     The aerator  10  has a single central air delivery column  26  extending substantially vertically through the center hole or passage of the toroidal float  12 . The upper end  28  of the column  26  is preferably immovably affixed to the float  12  by suitable braces or the like (not shown) where it passes through the center of the float  12 , and by additional similar but longer braces  30  extending from the lower portion or end  32  of the column to each of the support legs  18 . 
     An aeration outlet  34  is immovably affixed to the lower end  32  of the air delivery column  26 , and thus to the remaining structure of the aerator  10 . The aeration outlet  34  comprises a relatively flat or thin circular central plenum  36  and a plurality of radially disposed and perforated aeration tubes or nozzles  38  extending therefrom. A circular brace  40  is disposed concentrically about the aeration or diffuser tubes  38  and spaced outwardly from the plenum  36 , tying the tubes  38  together for greater security. Since the aeration outlet  34  is immovably affixed to the remaining structure of the aerator  10 , including its float  12 , it will be seen that the aeration tubes  38  remain at a constant fixed depth below the float  12 . Thus, as the float  12  rides upon the surface of the water (assuming adequate water depth so that the legs  18  are not resting upon the floor F of the body of water W), the aeration tubes  38  also remain at a constant fixed depth below the surface of the water. Since this depth is fixed, the water pressure or head at the depth of the aeration tubes is also fixed, thus requiring a constant air pressure from the air supply of either  FIG. 3  or  FIG. 4 . No adjustment of the air pressure is required for the aerator  10  once the pressure has been set. 
       FIG. 2  of the drawings provides a perspective view of another buoyant aerator, designated as aerator  110 . The aerator  110  includes many components that correspond to those like components of the buoyant aerator  10  illustrated in  FIG. 1  and described above. The aerator  110  has a buoyant toroidal float  112  having a periphery  114  and a plurality of leg attachment passages  116  installed thereon. Corresponding parallel rigid vertical guides  118  have lower ends  120   a  anchored or immovably affixed in a heavy base  120   b  of concrete or the like. The base of the aerator  110  rests immovably upon the floor F of the body of water W, as shown in  FIGS. 3 and 4 . This structure allows the float  112  to move vertically between the guides  118  as the water level changes, the leg attachment passages  116  sliding vertically along the guides  118 . Corresponding anchor cables or lines  122  extend from the leg attachment passages  116 . The distal ends  124  of the cables  22  are anchored into the floor F of the body of water W (shown in  FIGS. 3 and 4 ) to provide further security for the aerator  110 . 
     The aerator  110  has a single central air delivery column  126  extending substantially vertically through the center hole or passage of the toroidal float  112 . The upper end  128  of the column  126  is preferably immovably affixed to the float  112  by suitable conventional braces or the like (not shown) where it passes through the center of the float  112 . An aeration outlet  134  is immovably affixed to the lower end  132  of the air delivery column  126 , and thus to the remaining structure of the aerator  110 . The aeration outlet  134  comprises a relatively flat or thin circular central plenum  136  and a plurality of radially disposed and perforated aeration tubes or nozzles  138  extending therefrom. A circular brace  140  is disposed concentrically about the aeration or diffuser tubes  138  and spaced outwardly from the plenum  136 , tying the tubes  138  together for greater security. 
     In  FIG. 2 , the position of the float  112 , air delivery column  126 , and aeration outlet  134  is shown with the float positioned near the upper ends of the vertical guides  118  in solid lines, as would be the case with a relatively high water level. If the water level decreases, the float  112  with its attached air delivery column  126  and aeration outlet  134  will descend with the water level, thus lowering the float, column, and aerator outlet, as shown in broken lines in  FIG. 2 . Since the aeration outlet  134  is immovably affixed to the lower end  132  of the air delivery column  126  and the air delivery column  126  is immovably affixed to the float  112 , it will be seen that the aeration tubes  138  remain at a constant fixed depth below the float  112 . Thus, as the float  112  rides upon the surface of the water (assuming adequate water depth so that the aeration outlet  134  is not resting upon the anchor base  120   b ), the aeration tubes  138  also remain at a constant fixed depth below the surface of the water. Since this depth is fixed, the water pressure or head at the depth of the aeration tubes is also fixed, thus requiring a constant air pressure from the air supply of either  FIG. 3  or  FIG. 4 . No adjustment of the air pressure is required for the aerator  110  once the pressure has been set. 
       FIG. 3  of the drawings is a pictorial illustration of a buoyant aerator array, showing a plurality of different types of buoyant aerators receiving their air supplies from a single land-based source. The source of air for the buoyant aerators includes a compressor  210  driven by a suitable power source  212  (e.g., gasoline or diesel engine, electric motor, etc.). The compressor  210  delivers air to an air tank  214  to supply the offshore buoyant aerators. The compressor  210 , power source  212 , and air tank  214  are all installed and based upon the shore or land mass L, clear of the water W. Air is delivered to the various aerators by a separate flexible air delivery line  216  extending from the air tank  214  to each of the aerators, so that each aerator has its own air delivery line  216 . Each of the delivery lines  216  is supported above the surface S of the water W by one or more support columns  218 . Each of the support columns  218  is immovably affixed and anchored in the underlying land mass L or the floor F of the body of water W. 
       FIG. 4  of the drawings is a pictorial illustration of another buoyant aerator array, showing a plurality of different types or embodiments of buoyant aerators receiving their air supplies from a single floating vessel-based source. The source of air for the buoyant aerators includes a compressor  310  driven by a suitable power source  312  (e.g., gasoline or diesel engine, electric motor, etc.). The compressor  310  delivers air to an air tank  314  to supply the offshore buoyant aerators. The compressor  310 , power source  312 , and air tank  314  are all installed and based upon the floating vessel V in the water W. Air is delivered to the various aerators by a separate flexible air delivery line  316  extending from the air tank  314  to each of the aerators, so that each aerator has its own air delivery line  316 . Each of the delivery lines  316  is supported above the surface S of the water W by one or more support columns  318 . Each of the support columns  318  is immovably affixed and anchored in the floor F of the body of water W. 
     While each of  FIGS. 3 and 4  shows only three aerators, it will be seen that more aerators may be supplied by a single air source, depending upon the amount of air used by each aerator and the capacity of the air supply. 
     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.