Patent Abstract:
Circulation and aeration systems for ponds, lakes, sounds, treatment basins, and other bodies of water. In one set of embodiments, water is pumped in a downward direction to circulate ambient oxygen from the atmosphere and produced by plant photosynthesis to deeper strata. In other embodiments, water is circulated within predetermined depth strata. Each system preferably includes a wind turbine, a drive shaft, and an impeller array. Some systems include conduits for conveying and mixing water from and to selected depth strata, or configured as an open impeller-mixing apparatus. Alternative embodiments include systems which incorporate electrical power generation by the wind turbine, solar power generation and use hybrid wind-solar apparatus, and combinations of land-based and in-water based apparatus. A pneumatic pump diffuser and a control flow centered orifice diffuser line are employed in some embodiments.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application No. 61/284,450 filed on Dec. 18, 2009, the entirety of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Field of the Invention 
     This invention relates to the field of aeration and circulation systems for ponds, lakes, sounds, treatment basins and other bodies of water; and especially to the field of aeration and circulation systems for bodies of water which experience periods of thermal-density stratification and oxygen depletion. 
     2. Discussion 
     Deep dimictic lakes typically exhibit a well mixed surface layer (epilimnion), a mid-depth where temperature decreases rapidly with increasing depth (metalimnion), and a uniformly cold deep layer (hypolimnion). Oxygen is supplied to the surface of the body of water from the atmosphere. Oxygen is also produced by photosynthesis within the body of water. When light penetration is limited, oxygen production by photosynthesis only occurs in upper strata. In more shallow water bodies such as, for example, lakes, estuaries, sounds and treatment basins that exhibit very high oxygen demand over the bottom, a weak or intermittent thermal stratification can occur and can result in oxygen depletion in deeper strata. The deep strata oxygen consumption rate and oxygen demands at the sediment/water interface can exceed the oxygen replenishment rate from the atmosphere and photosynthetic production near the surface. 
     The loss of dissolved oxygen from waters at various depths can have serious water quality consequences including:
         Loss of desirable habitat for fish and other aerobic aquatic organisms;   Accumulation of nutrients and anaerobic respiration products such as iron, manganese, hydrogen sulfide, phosphorus, ammonia and other constituents; and   Increased eutrophication and degradation of resource quality for recreation, habitat, and water supply.       

     The thermal density stratification and oxygen depletion is characterized by an index: relative thermal resistance to mixing (RTRM). Intervention may be required to increase and enhance circulation and aeration to improve and maintain water quality. 
     SUMMARY 
     Briefly stated, an apparatus for circulating water in a body of water employs a wind turbine. A shaft is driven by the turbine. At least one impeller is coupled to the shaft for rotation therewith. A buoyancy module is disposed adjacent the shaft to maintain the shaft in an upright vertical orientation when a substantial portion of the shaft and the at least one impeller is submerged in the body of water. Exposure of the wind turbine to environmental wind and disposition of the impeller in the body of water causes the impeller to rotate to thereby circulate water to and from selected depths. 
     The apparatus can be configured to produce a mixing or blending of a depth strata, a downdraft circulation, or an updraft circulation within the body of water. In one embodiment, the apparatus includes a conduit. The impeller unit, or plurality of impellers, is disposed in the conduit and produces either a downdraft or an updraft pumping within the conduit. For some embodiments, the apparatus produces both a downdraft and an updraft pumping. 
     The apparatus may also comprise a conduit chamber with an intake port and an output port. At least one impeller is disposed in the conduit chamber and operable to circulate water from the intake port to the output port for depth-selective circulation of any vertical depth strata range. 
     The apparatus may also comprise a plurality of impellers spaced along the shaft. The apparatus can be configured to produce a downdraft circulation path, an updraft circulation path or a combination of downdraft and updraft circulation paths. 
     The apparatus may employ a wind turbine, which comprises either a direct drive vertical axis wind turbine or a horizontal axis wind turbine which rotatably couples with the shaft. The apparatus in one embodiment comprises a pumping chamber. At least one impeller is disposed within the pumping chamber. A direct drive compressor is coupled to the wind turbine to produce compressed air. An alternator stator is coupled to the wind turbine to generate electricity in some embodiments. In addition, a battery bank, a controller and a motor is drivably couplable to the shaft wherein the electricity from the alternator stator is employed to power the motor. 
     A solar voltaic array may be employed. A battery bank in communication with the array and a motor powered by the battery bank drives the shaft or a compressor may be employed. In some embodiments, the wind turbine is a vertical axis wind turbine and a horizontal axis wind turbine is integrated with the vertical axis wind turbine. The vertical axis wind turbine is coupled to the shaft for pumping circulation and to produce compressed air for diffusion into the water. 
     For some embodiments, a surface flotation platform mooring system employs an anchor system. At least one pulley is connected to the flotation platform. A cable connects the anchor, extends around the pulley and connects with a weight. The vertical spacing between the anchor and the flotation platform varies according to the depth of the water. 
     The apparatus may also be anchored by a plurality of pilings mounted to the bottom of the body of water in a fixed, upright position. The apparatus further has a platform disposed about the shaft. Tubes extend from the underside of the platform and are telescopically connected with the pilings so that the position of the wind turbine relative to the surface of the water is substantially constant regardless of the change in depth of the water. For bodies of water in which the water level does not significantly fluctuate, it is preferred that the apparatus be anchored by a heavy weight and a submerged buoyancy system to maintain the upright vertical position. 
     A wind turbine apparatus or photovoltaic array and battery bank system may also be employed to compress air. The compressed air is supplied via a conduit to an aeration diffuser heads disposed below the surface of the water. In some embodiments, the compressor is powered by a solar array which is installed on the land. A plurality of aeration heads is employed to distribute compressed air and circulate and oxygenate the water below the surface of the water. The aeration heads have openings, flow-controlling orifices, which are dimensioned to maintain pressure throughout the compressed air supply conduit regardless of distance or depth of diffuser, to ensure equal airflow to all diffuser elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a body of water and its surrounding environment, partly in diagram form, further illustrating three embodiments of a wind turbine circulator/aerator installed in the body of water; 
         FIG. 2A  is a schematic view, partly in diagram form, of a body of water and its surrounding environment further illustrating depth profiles of temperature, RTRM and dissolved oxygen for epilimnion, metalimnion, and hypolimnion layers of the body of water and  FIGS. 2B-2E  are four embodiments of a wind turbine circulator/aerator as installed and operational in connection with the depth profile for a deep lake-type body of water; 
         FIG. 3  is a schematic view, partly in diagram form, of a body of water and its surrounding environment further illustrating depth profiles of temperature, RTRM and dissolved oxygen for depth layers of the body of water together with three embodiments of a wind circulator/aerator as installed and operating with the depth profile for a shallow lake-type body of water; 
         FIG. 4  is a perspective elevational view of a wind turbine circulator; 
         FIG. 5A  is an elevational schematic view, partly in diagram form, illustrating a submerged buoy erect piling mooring system for a wind turbine circulator and further illustrating a submerged buoyancy installation approach; 
         FIG. 5B  is an elevational schematic view, partly in diagram form, illustrating another embodiment for a wind turbine circulator which also includes a solar voltaic array and associated equipment and further illustrating a submerged buoyancy installation approach; 
         FIG. 5C  is an elevational schematic view, partly in diagram form, illustrating another embodiment for a wind turbine circulator and a wind powered electrical generator apparatus; 
         FIG. 6A  is a schematic view, partly in diagram form, illustrating the effects of the wind which creates a cylindrical circulation pattern at the surface which can be observed by Langmuir streaks in the body of water, together with an installed wind turbine circulator which transmits wind-induced circulation energy deeper into the water body; 
         FIG. 6B  is a schematic view, partly in diagram form, of another embodiment of a wind turbine circulator employing impellers for both updraft and downdraft pumping and mixing of selected depth strata; 
         FIG. 6C  is a schematic view, partly in diagram form, further illustrating another embodiment of a wind turbine circulator to pump circulated aerated water downward through a conduit and blending into a deep, cold hypolimnion layer; 
         FIG. 6D  is a schematic view, partly in diagram form, of another embodiment of a wind turbine circulator employing multiple impeller elements which can be deployed in any combination of updraft or downdraft direction; 
         FIGS. 7A ,  7 B and  7 C are schematic elevational views of three submerged buoyancy modules with wind turbine circulators, partly in diagram form, as installed in a body of water, with or without a conduit chamber for vertical conveyance of pumped water; 
         FIGS. 8A ,  8 B,  8 C,  8 D and  8 E and are elevational installed views, partly in schematic and partly in diagram form, illustrating various embodiments of a wind turbine circulator/aerator as installed in a body of water with combinations of wind and solar powered shaft circulation and diffused aeration by produced compressed air; 
         FIG. 9  is a schematic diagram of a wind turbine circulator illustrating possible propeller/impeller system configurations with respect to pitch, rotation and angle which can be employed in the various wind turbine circulators and circulator/aerators to accomplish updraft or downdraft pumping and horizontal mixing and circulation; 
         FIGS. 9A and 9B  are each a schematic diagram of a single propeller/impeller; 
         FIGS. 9C-9F  are two cooperative propellers/impellers sharing various pitches and rotations; 
         FIG. 12A  is an elevational schematic view, partly in diagram form, of a representative wind-solar circulator/aerator as mounted on pipe pilings; 
         FIG. 12B  is an elevational schematic view, partly in diagram form, of a hybrid wind-solar circulator/aerator as installed in a body of water to aerate and circulate several depth strata simultaneously; 
         FIG. 12C  is an elevational schematic view, partly in diagram form, of a hybrid wind-solar circulator/aerator as installed in a body of water and further illustrating a telescopic mount to accommodate fluctuating water levels; 
         FIG. 13  is an elevational installation view, partly in schematic and partly in diagram form, illustrating a solar powered circulator as installed in a water body; 
         FIG. 14A  is a side elevational view and an associated cross-sectional view, partly in schematic and partly in diagram form, illustrating a pneumatic diffuser which is employed in conjunction with the wind turbine circulator and aerator; 
         FIGS. 15A-15F  illustrate various applications for employing a pneumatic diffuser; 
         FIG. 16  is a schematic view of a diffuser and diffusing system which may be employed in conjunction with various circulators and aerators; 
         FIG. 17  is a schematic view illustrating a flow restricting size control of the amount of air delivered to a diffuser limit of  FIG. 16 ; 
         FIG. 18  is a chart illustrating how flow restricting orifices control the amount of air delivered to the diffuser units of  FIG. 16  and various representative line pressures; and 
         FIG. 19  is a schematic view, partly in diagram form, illustrating a body of water and its surrounding environment and a hybrid wind solar power generator which is land based for a solar power system for three aeration and circulation techniques. 
     
    
    
     DETAILED DESCRIPTION 
     With reference to the drawings wherein like numerals represent like parts throughout the several figures, a wind turbine circulator is designated generally by the numeral  10  in  FIG. 4 . The wind turbine circulator  10  is self-powered and functions to circulate water in bodies of water so as to achieve mixing between selected depth layers. 
     As described herein, various types of circulators and circulator/aerators can be deployed for enhancing the water quality for bodies of water, such as reservoirs and lakes. Wind turbine circulators and wind turbine circulator/aerators are specifically adapted and installed to provide several functions, such as mixing and circulation of a specified depth range to create an aerobic layer bounded by functional thermoclines above and below the layer; downward expansion of the epilimnic mixed layer and associated downward transport of oxygen; and the downward transport of oxygenated water to the deep hypolimnic strata to offset demand. The circulators and circulator/aerators preferably do not require auxiliary power, but are powered by wind and solar energy and a combination of wind powered drives and solar panel produced energy. 
     In a body of water to which the wind turbine circulators and circulator/aerators of the present disclosure have particular applicability, the body of water receives oxygen from the atmosphere as well as oxygen available at some depths from photosynthesis. As schematically illustrated in  FIG. 1 , there is a potential source of nutrients, anaerobic respiration products and other bottom generated contaminants which are introduced from the bottom into the body of water when dissolved oxygen is depleted. For most applications which benefit from enhanced circulation or aeration of deep or shallow water bodies, it is preferred to enhance circulation in a downward direction or within a specified depth strata while maintaining a stratified condition. The latter is preferred in order to minimize the adverse impact of up-welling nutrients, and anaerobic respiration products, such as iron and manganese, and other bottom generated contaminants. 
     The heavy black arrows in  FIGS. 1-3  and  19  represent general induced water flow direction. 
     Wind turbine circulator  10  illustrated in  FIG. 4  is highly efficient and is self-powered from the surrounding environmental forces. A support tube  20  connects an impeller unit  22  and extends through a buoyancy module  24  to upwardly support a wind turbine  30 . Upon installation, the turbine  30  is rotatable about a vertical axis and is positioned above the surface of the body of water. The turbine  30  includes a plurality of wind sails  32  which are generally equidistantly mounted by a pair of axially (vertically) spaced mounting brackets  34  extending from a central hub  36 . 
     There is a variety of specific wind turbine engines which are suitable to spin the shaft, including a three wing design, Savonius “scoop-type” design, Giromill, Darrieus, Helical, Lenz Wing and turbines such as those used for roof ventilation. Alternatively, the turbine could be a horizontal turbine, like a windmill, using a 90° gearbox to turn the vertical shaft. A shaft  40  is connected to the wind turbine for rotation about a vertical axis. The shaft  40  extends through the support tube to fixedly couple with the impeller unit  22  to rotatably drive the impeller unit  22 . The impeller unit  22  includes a plurality of impeller prop blades  42 . The impeller unit is housed within a protective cage formed by a pair of spaced plates  44  and axial struts  46 . 
     Upon proper installation, the wind turbine circulator  10  is installed upright in the body of water so that the wind turbine  30  is positioned above the surface of the water, and the impeller unit  22  is positioned at a selected depth to provide for circulation of the water. The wind turbine circulator is stabilized by the buoyancy module  24 . The module  24  stabilizes the wind turbine circulator in an upright relatively stable position wherein the impeller unit  22  is positioned at a generally direct location below the surface of the water to generate the desired water circulation. 
     As schematically illustrated in  FIGS. 1 and 2 , various wind turbine circulators are designated as  10 A,  10 B,  10 C and  10 D. Circulator  10 A includes an elongated shaft  40 A which mounts and rotatably drives a pair of axially spaced impeller units  21  and  23 . The impeller units are configured and mounted for providing concurrently a downward directional circulation and an upward circulation. It should be appreciated that as the wind turbines rotate due to the environmental wind currents above the surface of the water, the impellers also rotate due to the fixed rotational relationships between the impeller units  21 ,  23 ,  25  and  27  and the wind turbine. 
     Wind turbine circulator  10 B includes a single impeller unit  21  which essentially provides for a downward circulation. For the wind turbine circulator  10 B illustrated in  FIG. 2 , the length of the shaft  40 B is longer and the impeller  21  is configured to provide a downward direction to circulate the water and transport ambient dissolved oxygen from more shallow aerobic strata to deeper depths. 
     Wind turbine circulator  10 C includes a cylindrical chamber  60  which is mounted to the support post and includes an upper intake port  62  and a lower output port  64 . The impeller unit  21  is housed within the chamber  60  and functions to provide a downward circulation through the lower output port  64 , as best illustrated in  FIGS. 1 and 2 . Wind turbine circulator  10 C is employed to provide downward transport of oxygenated water to the deep hypolimnetic strata to offset the demand. 
     For the wind turbine circulator  10 D illustrated in  FIG. 2 , a multiplicity of impeller units  21 ,  23 ,  25  and  27  are employed. Impeller unit  21  provides a downward circulation. Impeller units  25  and  27  cooperate to provide intermediate downward and upward circulations. Impeller unit  23  provides an upward circulation to mix in circulating water. 
     A preferred application of the wind turbine circulators  10 A,  10 B,  10 C and  10 D may be appreciated by reference to  FIG. 2 . Wind turbine circulator  10 A is employed to provide mixing circulation at a specified depth range to create an aerobic layer bounded by the upper and lower functional thermoclines. Wind turbine circulator  10 B provides a downward expansion of the epilimnetic surface layer and associated downward transport of dissolved oxygen. 
     The wind turbine circulators  10 A,  10 B and  10 C can also be employed, as best illustrated in  FIG. 3 , in shallow lakes and other water bodies which exhibit intermittent stratification and/or a very high demand for dissolved oxygen. It will be appreciated that in this type of water body, the oxygen consumption in deeper strata and oxygen demands at the sediment water interface can exceed the oxygen replenishment rate from the atmosphere and photosynthetic production near the surface. Consequently, wind turbine circulator  10 A can be employed to provide a mixing circulation at a specified depth to increase oxygen delivery to the bottom. Turbine  10 C is employed to produce a downward transport of oxygenated water to the bottom waters to offset the high sediment oxygen demand. 
     A wind turbine circulator and/or wind turbine circulator aerator may be subject to significant damage from wave action across the body of water, especially during major storms. Consequently, for some embodiments, it is required that the structures be sufficiently anchored and adapted to alleviate the adverse effects of wave action. As illustrated in  FIG. 5A , the wind produces a representative wave height h and a wave length λ across the body of water. 
     Wind turbine circulator  100  employs a submerged buoyancy piling and mooring system  110 , as illustrated in  FIG. 5A . The buoyancy module  124  is sufficiently submerged below the surface of the water so that it will not be exposed to significant wave-induced oscillations. A pair of impeller units  121 ,  123  produces a cooperative downward and upward circulation below a platform  112 . The platform is anchored at the bottom of the body of water. The anchoring may be provided by vertical pipes  114  secured to an anchor base  116  as illustrated or by a cable/chain mooring-type system. Alternatively, the anchoring connection can be provided by ropes, cables, chains and other solid connectors. 
     A tubular support post  118  extends from the impeller module through the water surface where it mounts the wind turbine  130 . A rotatable drive shaft  140  is housed in the pipe  130 . The wind turbine rotates the shaft  140  which directly drives the impellers. The buoyancy module  124  which is mounted below the surface of the water maintains the pipe  130  and the shaft  140  in a substantially erect vertical position. The anchor weight of the anchor base  116  has a ballast counterweight that is significantly greater than the buoyancy of the buoyancy module  124 . For wind turbine circulator  100 , the module  124  principally functions to maintain the vertical position of the surface structures. 
     Alternatively, a hybrid solar wind powered circulator  100 B illustrated in  FIG. 5B  employs a solar/photovoltaic array and associated equipment disposed in a housing module  104  (schematically shown). The apparatus includes a charge controller  105 , a load controller  106  and a battery system  107 . The battery system drives a DC or, if inverted, an AC, motor  108  or compressor system. The motor rotates the shaft to provide both air lifting and pumping as well as aeration of the impeller units during calm intervals. 
     Another embodiment in the form of a hybrid wind generator powered apparatus  100 C is illustrated in  FIG. 5C . This embodiment includes an alternator stator assembly  109  which generates electricity. A charge controller  105 , load controller  106  and battery system  107  drives a DC motor compressor  150  to again provide airlifting, pumping or aeration of the apparatus during calm intervals when the wind is not sufficient to otherwise rotate the impellers and provide sufficient aeration. 
     Wind across the body of water also does produce circulation and mixing in the form of horizontal cylindrical water columns. These columns result in observed Langmuir streaks on the surface, as illustrated in  FIGS. 6A-6C . As illustrated, the convergence of these columns produce divergent upwelling currents and convergent downwelling currents. A wind turbine circulator  200  employs a plurality of impeller elements  221 , which may have either a clockwise or counterclockwise pumping direction, to capture the wind energy and transmit it vertically down into the water to extend the depth of the wind induced mixing. 
     As best illustrated in  FIG. 6B , wind turbine  200 B employs impeller units  221  and  223  configured to provide opposing clockwise rotations so that a blended layer or circulated layer is formed. In addition, only downward impellers (not illustrated) may be located to provide downward mixing for conditions wherein the bottom surface serves as a barrier to the downward circulation. 
     The wind turbine circulator  200 C illustrated in  FIG. 6C  employs a conduit  260  with a lower, nozzle-like peripheral outlet  264  which is restricted. The circulated water in the conduit is pumped or downwardly forced from a relatively shallow depth through the conduit  260  to mix and be forced through outlet  264  into the deep cold hypolymnium. A Venturi-type eduction of the outflow induces blending with deep water. 
     The wind turbine circulator  200 D illustrated in  FIG. 6D  employs multiple impeller units  221 ,  223 ,  225  and  227  to achieve the desired mixing and layering. 
     The vertical axis wind turbine circulator for a submerged buoyancy module may be configured in a number of circulation configurations with respect to the water level was illustrated in  FIGS. 7A-7C . Wind turbine circulator  110  employs a pair of impeller units  121 A,  123 A which provide concurrent upward and downward pumping or circulation. The circulator is anchored to a base  116 A at the bottom of the water body. 
     Wind turbine circulator  110 B employs a cylindrical chamber  160 B which surrounds the impeller units  121 A,  123 A and has an upper and a lower inlet port  161 B,  163 B, respectively, and an intermediate outlet port  164 B. The impellers are configured concurrently to provide a downward and an upward circulation. 
     Wind turbine circulator  110 C employs a single impeller  121 C which provides a downward circulation path within a chamber  160 C. An upper inlet port  162 C is provided so that the circulator pumps water downwardly into a lower depth for release through outlet port  164 C to provide circulation. 
     A series of schematic representations illustrating how the capabilities of a circulator  300  may be enhanced by various wind and solar dependent modules for conditions wherein the wind is greater than five miles per hour and the sun is greater than five hours direct is illustrated in  FIGS. 8A-8E . The circulator configurations are illustrated in relation to water level w. A compressor  350  may be added to provide, for example, 3-4.5 CFM at 30 PSI. In addition, a windmill  370  may be added to provide additional power so that, for example, 6-9 CFM may be produced. In addition, it is possible to provide a supplement of solar direct drive  380  for any of the various configurations. 
     The propellers for the impeller systems for circulator  300  (and other circulators) can be selectively configured to provide various circulation qualities as required for a given application. This is best illustrated by the charts of  FIG. 9 . The propeller pitch, e.g., the displacement that the propeller makes in a 360° rotation about the shaft, can be selected to provide for desired torque and vertical axis wind turbine windspeed (VAWTRPM). The rotation of the propeller can be clockwise (CW) or counterclockwise (CCW) rotation. The angle of the propeller (P) can be varied and fixed to focus on more horizontal mixing or more vertical mixing and pumping. Naturally, with multiple propellers, various combinations can be employed to accomplish the desired horizontal and vertical functions. 
     Another problem that is encountered upon installation of wind turbine circulators in water bodies is that the water bodies themselves may experience significant water level fluctuations (Δw). The water level fluctuations may be compensated by the schematic illustration of  FIG. 10 . An anchor  402  is fixedly positioned at the bottom of the body of water. Connecting pulleys  404  are mounted to a flotation platform  406  positioned at the surface of the water  406 . A wind turbine circulator  400  is mounted to the flotation platform. A cable  408  connects at one end with the anchor  402  and extends around a pulley  404  at opposed sides of the flotation platform  406 . A counterweight  410  is placed on the other end of the cable. Multiple pulleys  404 , cables  408  and counterweights  410  are preferably employed. 
     Consequently, as the level of the water changes from w to w′, as illustrated in  FIG. 10 , the pulley system and counterweights function to maintain the proper position of the wind turbine circulator  400  relative to the upper surface of the water. 
     With reference to  FIG. 11 , wind turbine circulator/aerator  500  employs a direct drive air compressor  550  on the drive shaft  540 . The circulator/aerator thus not only circulates the water, but provides for a diffused aeration enhancement through the drive of the wind turbine  530 . In addition, the circulator  500  employs a photo voltaic array of solar panels  502  which generate power. A controller  504  and battery pack  506  are employed to power a motor  508 . The motor  508  connects to the shaft  540  for driving the shaft and the compressor  550  to provide diffused air enhancement of the wind turbine when the wind velocity is relatively low or insufficient to provide suitable circulation and aeration. 
     Alternatively, any of the foregoing described wind solar circulation/aerators can be mounted onto pipe piling installations  570  as illustrated in  FIG. 12A . Pipes  572  are anchored into the bottom of the water body and extend upwardly. A platform  574  includes downwardly extending parallel tubes  576  which are slidably received over the pipes  572 . The tubes  576  telescopically change position as indicated by the arrow A to accommodate the depth changes in surface of the water w. In addition, the pipe/tube assembly provides a very efficient way of removing and installing the circulator or circulator/aerator installations when required for seasonal purposes. 
     With respect to the anchoring system illustrated in  FIG. 12B , the platform  584  is the top of a cylindrical chamber  586 . The platform  584  is mounted below a tandem impeller unit  521 ,  523  and above a third impeller unit  525 . Impeller unit  525  is disposed in the chamber  586  which has an input port  587  and an output port  589 . Aerated water is preferably forced downwardly out of the output port  589  at the lower portion of the circulator/aerator unit. The chamber may rest on the bottom of the body of water or may be anchored to the bottom. 
     As best illustrated in  FIG. 12C , the platform  594  may also be disposed below the buoyancy module  524 . A pair of telescopically received chambers  596 ,  598  houses a dual impeller unit  522  which forces the water downwardly. The relative position of the lower chamber  598  vis-à-vis the upper chamber  596  which houses the impellers varies is indicated by arrow C. An input port  597  at the upper portion below the platform  594  provides the input opening so that the water is forced to circulate downwardly through chambers  596 ,  598  and out of the bottom at the outlet port  599 . The compressor  550  also provides for oxygenation of the water which is typically warmer as it is circulated through the output port  599  into the generally cooler water level. 
     As additionally illustrated in  FIG. 13 , the power for water circulator  600  may also be solely provided by a solar array  602 . The solar array  602  provides power for a motor disposed in housing  604 . The motor drives the shaft  640 . In the illustrated embodiment, impeller units  621  and  623  are disposed below a platform  650  which is anchored to the bottom floor of the body of water. The buoyancy module  624  functions to keep the circulator in a generally upright orientation. 
     A pneumatic impeller diffuser  700  can be driven by compressed air to induce a circulation current and solute phase oxygen input from diffused air, as best illustrated in  FIGS. 14 and 14A . A housing  710  has a pair of bearings  712 ,  714  for mounting about a central rotatable shaft  740  having a communication channel  742 . The housing  710  forms a chamber  730  with an inlet  732  and an outlet  734 . Inner pump rotor  750  rotatable in the chamber  730  has reciprocating vanes  752 ,  754 ,  756 ,  758  which utilizes the expansion of compressed air to rotate the shaft and impeller. Release of exhausted air is jetted directionally to enhance impeller spin. 
     The air flows in the path as indicated by the arrows through the channel  742  to the impellers  720  and radially from the impellers for exit through ports  722 ,  724  in the impellers. As the drive shaft  740  rotates, the air is forced axially and then radially from the impellers into the water as the impellers also rotate. As further illustrated, the pneumatic diffuser  700  can be deployed for rotation in any direction and is easily coupled to the wind driven shaft of the wind turbine circulator. 
     The pneumatic diffuser  700  can be employed in a number of ways, as best illustrated in  FIGS. 15A-15F . In  FIG. 15B , the diffuser is employed in a pump chamber  760  for pumping while dissolving gas and aerating. In  FIG. 15D , the diffuser  700  is inverted in the pump chamber  760 . 
     As illustrated in  FIG. 15C , a pair of diffusers are employed in a mixing chamber  765  for circulating while dissolving the gas. Either directional rotation may be employed. The diffuser is deployed at the inside of the mixing chamber  765  for downward pumping while dissolving gas, namely, oxygenation contactors. In  FIG. 15E , the diffuser  700  is directionally employed as a means of propulsion inside a generally horizontally disposed housing  780 . As further illustrated in  FIG. 15F , the diffuser  700  may be employed inside an aeration chamber  770  using high pressure/low volume to enhance efficiency of diffused aeration using low pressure/high volume blowers  772 . 
     As illustrated in  FIGS. 16 and 17 , compressed air can be delivered in equal proportions to a plurality of diffuser elements  810  regardless of distance from compressed air source or water depth and pressure. A flow restricting orifice  830  controls the air volume to each diffuser assembly  810 . The flow limiting orifice  830  maintains pressure throughout the main feed line  820  so that diffusers can operate with an even airflow in terms of CFM distribution regardless of the pipe length and depth. By controlling airflow in this manner, the entire length of the feed line from the compressor is maintained at a pressure that feeds an equal amount of airflow to each diffuser, regardless of the depth/pressure of distance from the compressor as illustrated in  FIG. 19 . The diffuser heads may be configured for various internal flow paths as schematically illustrated for heads  812  and  814  in  FIG. 19 . The multi-diffuser approaches can be deployed with any of the described apparatus and methods that are driven by a diffuser and air-lift pumping, for example, hypolimnetic aerator units, layer aeration units, and design depth circulators. 
     As indicated by the graphical representations  FIG. 18 , the orifice diameters may be dimensioned to maintain a substantially constant air pressure. It should be noted that the flow restricting orifice sizes are dimensioned so that the amount of air delivered to each diffuser element under pressure is substantially equalized. The orifice sizes are selected based on the total CFM and the required line pressure. 
     It should be appreciated that a hybrid wind solar panel generator  900  can essentially also be land based. Generator  900  drives an air compressor diffuser for diffused air circulation for hypolimnetic aeration, circulation, or layer aeration schematically illustrated in  FIG. 19 .

Technology Classification (CPC): 5