Patent Publication Number: US-2023144514-A1

Title: Water and wastewater conditioning apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Patent Application No. PCT/US2021/041613, filed on Jul. 14, 2021, which claims the benefit of the filing date of 
     Provisional U.S. Patent Application No. 63/051,519, filed on Jul. 14, 2020, which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     Wastewater is used water that includes foreign substances such as food scraps, oils, chemicals, human waste, and storm runoff. Treatment and conditioning of wastewater is beneficial to the environment and for health. The goal of treatment is to remove suspended solids and unwanted impurities in the wastewater. Aeration is an important component for the treatment of wastewater, as oxygen is need for the bacteria that help with biodegradation of the wastewater. This supplied oxygen is used by the bacteria to break down the organic matter in the wastewater. It is beneficial to have methods of moving or pumping wastewater that also increase the amount of oxygen in the wastewater. 
     Thus, there is a need for improvement in this field. 
     SUMMARY 
     Certain embodiments include a fluid conditioning apparatus as well as fluid treatment systems. In one form, the fluid conditioning apparatus is a hydro turbulator system. The hydro turbulator system may include a volute including a length and a first duct and a second duct. The first duct and the second duct may be configured to allow fluid to enter and exit the volute, depending on whether the hydro turbulator system is operating in an up flow or down flow configuration. In the up flow configuration, the first duct acts as an inlet while the second duct acts as an outlet. In the down flow configuration, the first duct acts as an outlet while the second duct acts as an inlet. 
     An impeller system may be positioned within the volute. The impeller system may include a drive impeller and a first agitation impeller that in some embodiments are positioned in series along a fluid flow path extending through the volute between the first duct and the second duct. In some embodiments, the impeller system may include a second agitation impeller that is positioned in series with the drive impeller and the first agitation impeller along the fluid flow path. 
     One or more motors may be operationally connected to the impeller system, and the motor may be capable of rotating the drive impeller and the first agitation impeller upon operation of the motor. Rotation of the drive impeller and the first agitation impeller may create successive zones of high pressure and low pressure to agitate and condition fluid that enters the volute. In some instances, the motor may be axially aligned with the drive impeller and with the first agitation impeller. 
     A ratio of the diameter of the drive impeller to a hydraulic diameter of the fluid flow path at the drive impeller is greater than a ratio of the diameter of the first agitation impeller to a hydraulic diameter of the fluid flow path at the first agitation impeller. The drive impeller differs from the first agitation impeller by diameter, blade pitch, and/or number of blades. 
     In some embodiments, the impeller system may include an impeller driveshaft that is operationally attached to the drive impeller and the first agitation impeller so that rotation of the impeller driveshaft rotates the drive impeller and the first agitation impeller. A motor shaft may be attached to the motor and be rotatable upon operation of the motor. A coupling may be used to connect the motor shaft to the impeller drive shaft so that rotation of the motor shaft causes rotation of the impeller drive shaft. A motor mounting assembly may be coupled to an end of the volute and may support the motor. The motor mounting assembly may provide access to the coupling connecting the motor shaft to the impeller driveshaft. 
     In some embodiments, the hydro turbulator system may include a casing that surrounds at a least a portion of the volute. The volute may be slidable within the casing. An internal support base can be positioned within the casing, and the volute can be supported within the casing by the internal support base. 
     In some embodiments, when the impeller system is configured in up flow configuration, fluid entering the hydro turbulator system may be lifted over a dike, a bank, or a flume while also off-gassing volatile chemicals and adding dissolved oxygen to the fluid. The hydro turbulator system may be capable of transferring high quantities of fluid at low horsepower. 
     In some embodiments, the hydro turbulator system may include a ring positioned within the volute near the position of the drive impeller. The ring may have a ring diameter that is smaller than the diameter of the walls of the volute, and the ring defines the hydraulic diameter of the fluid at the drive impeller. In another form, the hydro turbulator system may be used in a fluid treatment system that includes a source fluid tank that can be filled with a source fluid to be treated. The hydro turbulator system may be in fluid communication with the source fluid tank. The hydro turbulator system used for the fluid treatment system may be similar to the hydro turbulator system already described above. For example, the hydro turbulator system may include a volute that has a top duct and a bottom duct that are configured to allow fluid to enter and exit the volute. An impeller system including a first impeller and a second impeller may be positioned within the volute. Rotation of the first impeller and the second impeller is configured to create successive zones of high pressure and low pressure to agitate and condition the fluid within the volute. In some embodiments, the first impeller and the second impeller may be axially aligned. Further, in some embodiments, the impeller system may include a third impeller axially aligned with the first impeller and the second impeller. 
     A gas capture tank may also be in fluid communication with the hydro turbulator system to receive fluid discharged from the hydro turbulator system. The gas capture tank may include treatment media configured to remove unwanted chemicals from the fluid discharged from the hydro turbulator system. In some embodiments, the fluid treatment system may also include a gas discharge blower attached to the gas capture tank. The gas discharge blower may remove off gassed volatile chemicals from the gas capture tank. 
     In some embodiments, the hydro turbulator system may be arranged in a dry configuration in which the hydro turbulator system is positioned exterior to the source fluid tank and the gas capture tank. In other embodiments, the hydro turbulator system may be arranged in a submerged or semi-submerged configuration in which the hydro turbulator may be at least partially submerged in the source fluid of the source fluid tank. 
     When in the semi-submerged configuration, a debris guard may surround the bottom duct of the hydro turbulator system. The debris guard can be configured to prevent large particles from entering the hydro turbulator system. In some instances, the hydro turbulator system can be supported within the source fluid tank by the debris guard. 
     Additionally, in the dry configuration, the agitation propellers of the hydro turbulator system  100  may be positioned at a location that has less head pressure in the static configuration when compared to the head pressure on the drive impeller in the static configuration. This arrangement further encourages the creation of cavitation by the agitation propellers to increase mixing and agitation of the fluid passing through the hydro turbulator system  100 . In some embodiments, the head pressure at the agitation propellers is decreased by positioning the agitation propellers closer to the fluid level than the drive propeller. 
     In another form, the fluid treatment system comprising includes a fluid treatment tank filled with a fluid to be treated and a hydro turbulator system as described above. A discharge extension extending from either the top duct of the hydro turbulator system or the bottom duct of the hydro turbulator system. Fluid conditioned within the hydro turbulator system may be discharged into the fluid treatment tank from the discharge extension. 
     A suction extension pipe may extend from either the top duct or the bottom duct, whichever is the duct from which the discharge extension does not extend from. At least a portion of the suction extension pipe may be arranged to be substantially parallel to the discharge extension. The suction extension pipe may be configured to provide suction to pull fluid into the hydro turbulator system. In some embodiments, at least one debris pipe extends from the suction extension pipe. The debris pipe may prevent large particles within the fluid from entering the suction extension pipe. 
     Fixed treatment media can be positioned between at least a portion of the discharge extension and a portion of the suction extension pipe. Typically, the fixed treatment media may be positioned between the portions of the discharge extension and the suction extension pipe that are substantially parallel to each other. Fluid discharged from the discharge extension is pulled by the suction extension pipe so that the discharged fluid flows through the fixed treatment media. 
     The hydro turbulator system may be operated in either an up flow configuration (e.g., against the force of gravity) or in a down flow configuration (e.g., with the direction of gravity). When the hydro turbulator system is operated in the up flow configuration, the top duct is fluidly connected to the discharge extension and the bottom duct is fluidly connected to the suction extension pipe. In the down flow configuration, the top duct is fluidly connected to the suction extension pipe and the top duct is fluidly connected to the discharge pipe. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1 A  is a front elevation view of a hydro turbulator system with an impeller system operating in down flow. 
         FIG.  1 B  is a front elevation view of the hydro turbulator system of  FIG.  1 A  with the impeller system operating in up flow. 
         FIG.  2    is a cutaway view of the hydro turbulator system of  FIGS.  1 A and  1 B . 
         FIG.  3    is a diagrammatic view of a dry installation of the hydro turbulator system of  FIG.  1 B  with a source fluid tank. 
         FIG.  4    is a diagrammatic view of the hydro turbulator system of  FIG.  1 B  with the source fluid tank of  FIG.  3    and a gas capture tank. 
         FIG.  5    is a diagrammatic view of the system of  FIG.  4    with an extended discharge pipe from the hydro turbulator system. 
         FIG.  6    is a diagrammatic view of the hydro turbulator system of  FIG.  1 B  installed in a semi-submersible arrangement in a source treatment tank. 
         FIG.  7    is a diagrammatic view of the semi-submersible arrangement shown in  FIG.  6    with a gas capture tank. 
         FIG.  8    is an embodiment of a hydro turbulator system installed within a casing. 
         FIG.  9    is a diagrammatic view of the hydro turbulator system of  FIG.  8    semi-submersed in a treatment tank including fixed treatment media. 
         FIG.  10    is a diagrammatic view of the hydro turbulator system of  FIG.  1 B  semi-submersed in a source treatment tank and including a turbulator discharge extension. 
         FIG.  11    is a top view of a round source treatment tank with the hydro turbulator system of  FIG.  10   . 
         FIG.  12    is an elevation side view of the hydro turbulator system of  FIG.  1 B  providing crossflow to treatment media in a rectangular treatment tank. 
         FIG.  13    is a top view of the hydro turbulator system and treatment tank of  FIG.  12   . 
         FIG.  14    is a cross-sectional elevation end view of the hydro turbulator system and treatment tank of  FIG.  12   . 
         FIG.  15    is a cross-sectional elevation end view of the hydro turbulator system and treatment tank of  FIG.  12   . 
         FIG.  16 A  is a diagrammatic view of the impeller system from the hydro turbulator system of  FIG.  1 B  including a ring within the volute. 
         FIG.  16 B  is a diagrammatic view of the impeller system of  FIG.  16 A  with various defined diameters. 
     
    
    
     DESCRIPTION OF THE SELECTED EMBODIMENTS 
     For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the invention as described herein are contemplated as would normally occur to one skilled in the art to which the invention relates. One embodiment of the invention is shown in great detail, although it will be apparent to those skilled in the relevant art that some features that are not relevant to the present invention may not be shown for the sake of clarity. 
     In some embodiments, a hydro turbulator system features a single impeller or multiple impellers/propellers. Fluid entering a volute of the hydro turbulator system encounters a drive impeller that produces high flow with low head. Additional impellers may be used to add flow and shear forces producing super cavitation from multiple low and high pressure areas that aggressively agitate the fluid and induce the formation of small and micro bubbles. These bubbles may off gas carbon dioxide (CO 2 ), volatile organic compounds (VOCs), hydrogen sulfide (H 2 S), and microbubbles with oxygen to aerate the fluid and raise dissolved oxygen levels. 
     Typically, the hydro turbulator system is operated in a vertical configuration that can be run in either down flow (e.g., in the direction of the force of gravity) or up flow (e.g., against the force of gravity). The hydro turbulator system may be semi-submersibly installed inside a tank with a flooded inlet and/or outlet, either with or without piping. Alternatively, the hydro turbulator system may be mounted dry, outside a tank with flooded inlet and gravity or piped outlet connections from the tank. 
       FIGS.  1 A and  1 B  each illustrate a hydro turbulator system  100  arranged in a different operating configuration.  FIG.  1 A  shows the hydro turbulator system  100  in a down flow configuration, while  FIG.  1 B  shows the hydro turbulator system in an up flow configuration. The hydro turbulator system  100  includes a housing that forms a volute  104 . The volute  104  spans between a top plate  106  and a mounting base  108  that supports the volute  104 . A top duct  112  and a bottom duct  116  are defined through the volute  104 , allowing fluid to either enter or exit the volute depending on the configuration in which the hydro turbulator system  100  is operating. The top duct  112  is positioned nearer to the top plate  106  while the bottom duct  116  is positioned nearer to the mounting base  108 . An impeller system  120  is positioned within the volute  104  and may include one or more impellers. The impeller system  120  is in fluid communication with the top duct  112  and the bottom duct  116 . 
     A motor  140  is attached to one end of the volute  104 . In the embodiment shown, the motor  140  is attached to the top plate  106  by a motor mounting assembly  145 . The motor  140  may include a motor shaft  142  that attaches to an impeller driveshaft  128  of the impeller system  120  at a coupling  132 . A water slinger may be positioned where the driveshaft  128  extends through the top plate  106  to prevent fluid escape through the opening in the top plate  128  through which the driveshaft  128  extends. The motor mounting assembly  145  may provide access to the coupling  132  connecting the motor shaft  142  and impeller driveshaft  128 . In some embodiments, the motor  140  may be a 1 horsepower, 1800 rpm, severe duty motor. The motor  140  may use a traditional power source and/or may be configured to operate using a sustainable power source, such as solar power. 
     As shown,  FIG.  1 A  illustrates the hydro turbulator system  100  in a down flow configuration. In the down flow configuration, the top duct  112  acts as an inlet for receiving the fluid to be treated. The bottom duct  116  acts as an outlet for the fluid being treated. The impeller system  120  pulls fluid from the top duct  112  and discharges the fluid through the bottom duct  116 .  FIG.  1 B  illustrates the hydro turbulator system  100  in an up flow configuration. In the up flow configuration, the top duct  112  acts as an outlet for the hydro turbulator system  100  and the bottom duct  116  acts as an inlet for the hydro turbulator system  100 . The impeller system  120  pulls water from the bottom duct  116  and pushes water out of the top duct  112 . Whether in the down flow or the up flow configuration, the duct  112 ,  116  acting as the outlet may be positioned above fluid level, just below fluid level or one meter or more (e.g., four feet or more) below fluid level as required to support different applications of the hydro turbulator system  100 . 
     A cross-sectional view of the hydro turbulator system  100  is shown in  FIG.  2   , so that the impeller system  120  may be seen in greater detail. The impeller system  120  includes a top bearing  121  and a bottom bearing  122 . A total of three impellers are positioned between the top bearing  121  and the bottom bearing  122  as shown in  FIG.  2   . A top impeller  124  acts as a drive impeller when the hydro turbulator system  100  is in down flow and acts as a final agitation impeller when the hydro turbulator system  100  is in up flow. A middle impeller  125  serves as a first agitation impeller for both the down flow and the up flow configurations. A bottom impeller  126  acts as a final agitation impeller when the hydro turbulator system  100  is in down flow and acts as a drive impeller when the hydro turbulator system  100  is in up flow. The impeller system  120  also includes an impeller driveshaft  128  which, as already described above, is operatively connected to the motor shaft  142  of motor  140  at a coupling  132 . 
     An impeller system  120  that includes multiple impellers produces high flow at low head and low horsepower for transferring, mixing, and aerating a source fluid while off gassing CO 2 , VOCs, H 2 S, and chlorine in water and wastewater to improve treatment performance. Flow within the hydro turbulator system  100  may be up to four times more fluid than a typical, high flow, low head centrifugal pump. Further, in some instances, the hydro turbulator system  100  may provide a minimum of 2 to 3 feet of piped lift. 
     In some embodiments, the top impeller may be mounted in a hyper turbulation position. When the hydro turbulator system  100  is operated in the up flow configuration and the top duct  112  is positioned to discharge fluid to a dry location, above the surface level of a source fluid, the top impeller operates in a flow lift area, creating hyper turbulation. Hyper turbulation significantly increases dissolved oxygen and produces a great amount of micro and small bubbles, as well as increasing aeration and off gassing of CO 2 , VOCs, H 2 S, chlorine, and other unstable water contaminants. 
     Although the impeller system  120  is shown with a total of three impellers in  FIG.  2   , in other embodiments, more or fewer impellers may be included as desired. As an example, the impeller system  120  may include only two impellers so that there is a drive impeller and a single agitation impeller. In another example, the impeller system  120  may include four impellers and include an additional agitation impeller. In a further example, the hydro turbulator system  100  may only include a single impeller, and the hydro turbulator system  100  is used to transfer and mix anaerobic wastewater without aeration to increase denitrification. 
     A dry installation of the hydro turbulator system  100  used for source fluid conditioning is illustrated in  FIG.  3   . The dry installation allows the hydro turbulator system  100  to be positioned outside of the fluid tank and to circulate and add oxygen to the fluid for the treatment process. A source fluid tank  200  holds a source fluid  205  to be treated in the hydro turbulator system  100 . As an example, the source fluid may be source raw water that is to be preconditioned by the hydro turbulator system  100 . The source fluid tank  200  includes a source tank cover  210  that covers the source fluid tank  200 . An air vent  212  may be positioned on the source tank cover  210  to allow air to escape from the source fluid tank  200 . A level control  215  is positioned within the source fluid tank  200  and is capable of metering the incoming source fluid to maintain a desired operating level within the source fluid tank  200 . 
     The source fluid tank  200  includes a source tank inlet  220  which receives source fluid to be held within the source fluid tank  200 . The source fluid tank  200  also includes a source tank outlet  225  which is in fluid communication with the bottom duct  116  of the hydro turbulator system  100 . A tank turbulator valve  230  is positioned at the interface between the source tank outlet  225  and the bottom duct  116  to allow a user to control when source fluid from the source fluid tank  200  is provided to the hydro turbulator system  100 . In some embodiments, the tank turbulator valve  230  may be an isolation valve, such as a gate valve. The aeration and off gassing of the source fluid performed by the hydro turbulator system  100  allows the source fluid to be transferred for further treatment or for other uses. 
     In the embodiment shown in  FIG.  3   , the hydro turbulator system  100  is arranged in the up flow configuration so that the bottom duct  116  acts as the inlet for the hydro turbulator system, and the top duct  112  acts as the outlet. As shown, the hydro turbulator system  100  may also include a mounting base extension  150  that may be used to adjust the height of the hydro turbulator system  100  so that the bottom duct  116  can align with the source tank outlet  225 . The mounting base extension  150  may include a mounting base adapter  152  that provides support for the mounting base  108  and base legs  154  extending from the mounting base adapter  152 . In some embodiments, discharge from the top duct  112  may be directed to a tank for treatment or to a pond, lagoon, wetland, drainage ditch, or other suitable location. 
       FIG.  4    shows a diagram of a dry installation of the hydro turbulator system  100  for source fluid preconditioning with the hydro turbulator system  100  discharging into a gas capture tank. The dry installation gas capture system shown in  FIG.  4   , includes the setup of the source fluid tank  200  and the hydro turbulator system  100  that is shown in  FIG.  3    and also includes a gas capture tank  300 . 
     The gas capture tank  300  includes a gas capture tank cover  310  that encloses the gas capture tank  300 . A gas capture tank inlet  320  allows fluid that has been processed in the hydro turbulator system  100  to be introduced into the gas capture tank  300 . A gas capture tank outlet  325  allows fluid within the gas capture tank  300  to be expelled from the gas capture tank  300  to a wetland, for reinjection, for reuse, or for any other desired purpose. 
     As shown in  FIG.  4   , a discharge extension spool  340  may be used to connect the top duct  112  of the hydro turbulator system  100  to the gas capture tank inlet  320 . The discharge extension spool  340  may include an extension inlet  342  that is in fluid communication with the top duct  112 . An isolation valve  330 , such as a gate valve, may be positioned between the extension inlet  342  and the top duct  112  to allow fluid flow between the extension inlet  342  and the top duct  112  to be controlled. The discharge extension spool  340  may also include an extension outlet  344  that is in fluid communication with the gas capture tank inlet  320 . In some embodiments, the discharge extension spool  340  may not be necessary, and the gas capture tank inlet  320  may be directly connected to the top duct  112  of the hydro turbulator system  100 . 
     The gas capture tank  300  is filled with treatment media  305  that is capable of recovering the off gas VOCs that is released from the fluid that has been treated by the hydro turbulator system  100 . A gas capture tank level control  315  may be included in the gas capture tank  300  to measure the level of the treatment media  305  and the fluid introduced from the hydro turbulator system. An induced ambient air inlet  312  is positioned in the top portion of the gas capture tank  300 , near the gas capture tank cover  310 . The induced ambient air inlet  312  allows ambient air to enter the gas capture tank  300  above the level of the treatment media  305 . 
     The gas capture tank  300  includes a media support grate  350  as a base for supporting the treatment media  305 . The media support grate  350  may be supported by vertical supports  352 . Additionally, the media support grate  350  may be configured to allow the preconditioned fluid that is filtered through the treatment media  305  to pass through the media support grate  350 . After passing through the media support grate  350 , the preconditioned fluid may be discharged from the gas capture tank  300  through the gas capture tank outlet  325 . 
     The gas capture tank  300  also includes a gas discharge system  360  that is coupled to the gas capture tank cover  310 . The gas discharge system  360  includes a gas discharge inlet  362  that is in fluid communication with the gas capture tank  300  through the gas capture tank cover  310 . The discharged gas enters the gas discharge inlet  362  and is passed to a gas discharge blower  364  that pumps the discharge gas through a gas discharge outlet  366  to a neutralization system if there are VOCs that need to be captured or to another suitable location. 
     In a raw water system, the gas capture tank  300  may be used for both aeration and off gassing of CO 2 , H 2 S, VOCs, and other gases. The microbubbles of rich oxygen raw water travel through the gas capture media and may be discharged through the gas capture tank outlet  325  at the bottom of the tank. 
       FIG.  5    shows an alternative embodiment of a dry installation of the hydro turbulator system  100 . In this embodiment, the gas capture tank inlet  320  includes a gas capture tank downcomer pipe  322  that extends downward, through the treatment media  305  and through the media support grate  350 . The fluid from the source fluid tank  200  flows through the downcomer pipe  322  and is discharged below the media support grate  350  and out flows through the bottom space of the gas capture tank  300  to flow up through the treatment media  305  and then through the gas capture tank outlet  325 , such as by gravity flow. 
     The additional length of provided by the downcomer pipe  322  further agitates the fluid discharged from the hydro turbulator system  100 . The gas capture tank outlet  325  is moved from a position near the bottom of the gas capture tank  300  to a position that is closer to the top of the gas capture tank  300 . In some embodiments, the position of the gas capture tank outlet  325  may be above the level of the wastewater and the treatment media  305 . 
     In an alternative embodiment, shown in  FIG.  6   , the hydro turbulator system  100  may be operated in a semi-submersible condition. In this embodiment, the hydro turbulator system is positioned at least partially within a source treatment tank  400  and a portion of the hydro turbulator system  100  is below the fluid level in the source treatment tank  400 . The source treatment tank  400  holds a source fluid  405  that has a source fluid level  406  and is covered by a tank cover  410  with an air vent  412  defined through the tank cover  410 . A level control  415  is positioned within the source treatment tank  400  to monitor the operating level of the source fluid  405  within the source treatment tank  400 . A source fluid inlet  420  receives source fluid that is held within the source treatment tank  400 . 
     In the embodiment shown in  FIG.  6   , the hydro turbulator system  100  operates in the up flow configuration, so that the bottom duct  116  of the hydro turbulator system  100  operates as an inlet for the hydro turbulator system  100 . The bottom duct  116  is surrounded by a debris guard  455  that prevents large organic or inorganic materials from entering the hydro turbulator system  100 . The debris guard  455  also acts as a support for the hydro turbulator system  100 , as the mounting base  108  of the hydro turbulator system  100  rests on the debris guard  455 . In some embodiments, the debris guard  455  may be integral to the hydro turbulator system  100 . 
     A source treatment tank outlet extension  440  includes a hydro turbulator interface  442  that is in fluid communication with the top duct  112 , which acts as an outlet when the hydro turbulator system  100  is in the up flow configuration. The source treatment tank outlet extension  440  also includes a tank outlet  444  that extends externally of the source treatment tank  400 . In this embodiment, the top duct  112  of the hydro turbulator system and the tank outlet extension  440  are positioned above the source fluid level  406 . 
       FIG.  7    illustrates the semi-submersible hydro turbulator system  100  shown in  FIG.  6    used with the gas capture tank  300  shown in  FIG.  5   . As shown, the source treatment tank outlet extension  440  may be connected to a source treatment tank outlet extension  470  that is in fluid communication with the discharge extension spool  340 . The discharge extension spool  340  connects to the gas capture tank inlet  320  and to the gas capture tank downcomer pipe  322  that extends through the treatment media  305 . This allows the hydro turbulator system  100  to be removed and then reinstalled without disturbing the treatment media  305 . 
     An alternative embodiment of the hydro turbulator system  100  is shown in  FIG.  8   . In this embodiment, the hydro turbulator system  100  includes a casing  160  that surrounds the volute  104 . An internal support base  162  is positioned within the casing  160  and rests on the mounting base  108  of the hydro turbulator system  100 . The volute  104  is capable of sliding within the interior of the casing  160  to be inserted into or removed from the casing  160  as desired. When positioned within the casing  160 , the volute is seated on the internal support base  162 . The casing may include an open intake, allowing fluid to enter the volute  104 . 
     In  FIG.  9   , the hydro turbulator system  100  including a casing  160  as illustrated in  FIG.  8    is shown in use within a tank including fixed treatment media. The wastewater treatment tank  500  is filled with wastewater  505  and with a layer of fixed treatment media  508 . The wastewater  505  has a wastewater level  506  within the wastewater treatment tank  500 . A level control  515  may be positioned within the wastewater treatment tank  500  to measure and control the level of the wastewater  505 . A wastewater tank cover  510  covers the wastewater treatment tank  500  and an air vent  512  allows air and gases within the wastewater treatment tank  500  to be expelled through the wastewater tank cover  510 . A wastewater tank inlet  520  allows wastewater to enter the wastewater treatment tank  500  and a wastewater tank outlet  525  provides an outlet for the wastewater in the wastewater treatment tank  500 . As shown in  FIG.  9   , the bottom of the wastewater tank outlet  525  may be aligned with the wastewater level  506 . 
     The hydro turbulator system  100  is partially submerged in the wastewater  505  and the fixed treatment media  508  within the wastewater treatment tank  500 . The hydro turbulator system  100  is supported on a debris guard  455  positioned within the wastewater treatment tank  500  and below the level of the fixed treatment media  508 . The bottom duct  116  of the hydro turbulator system  100  acts as an inlet for the hydro turbulator system  100  and is surrounded by the debris guard  455 . The hydro turbulator system discharges from the top duct  112 , which is connected to a discharge extension spool  540  that will mix the upper level of the wastewater treatment tank  500  over the fixed treatment media  508 . The casing  160  of the hydro turbulator system  100  runs through the fixed treatment media  508 , allowing the volute  104  to be removed and reinstalled from the casing  160  without disturbing the treatment media  508 . 
     Another embodiment of a semi-submersible hydro turbulator system  100  is shown in  FIG.  10   . Similar to the embodiment shown in  FIG.  6   , the hydro turbulator system  100  is positioned at least partially within a source treatment tank  400 . The source treatment tank  400  holds a source fluid  405  that has a fluid level  406  and is covered by a tank cover  410  with an air vent  412  defined through the tank cover  410 . A level control  415  is positioned within the source treatment tank  400  to monitor the operating level of the source fluid  405  within the source treatment tank  400 . A source fluid inlet  420  receives source fluid that is held within the source treatment tank  400 . 
     A source treatment tank outlet  444  allows wastewater to be discharged by the source treatment tank  400 . As shown, the source treatment tank outlet  444  is not directly connected to the hydro turbulator system  100 . Additionally, the source fluid level  406  corresponds with the position of the source treatment tank outlet  444 , so that the fluid level is above the bottom of the opening formed by the source treatment tank outlet  444 , but below the top of the opening of the source treatment tank outlet  444 . 
     In this embodiment, the hydro turbulator system  100  includes a turbulator discharge extension  170  that is coupled to the top duct  112  of the hydro turbulator system  100 . The turbulator discharge extension  170  includes one or more discharge ports  172  from which fluid from the hydro turbulator system  100  may be discharged to further agitate and circulate the source fluid  405 . In some embodiments, the source fluid  405  may also include a treatment media that is circulated by the hydro turbulator system  100  to improve performance. 
     The fluid level  406  of the source fluid  105  may be maintained at a level that is higher than the bottom edge of the source treatment tank outlet  444  to allow source fluid  405  to exit the source treatment tank  400 . In some instances, the source fluid  405  in the source treatment tank  400  may be processed in a batch operation, where a single batch of source fluid  405  enters the source treatment tank  400  and is conditioned before being drained from the source treatment tank  400  before new source fluid  405  is introduced. In other instances, the source fluid  405  may be processed in a continuous operation where source fluid  405  is constantly being introduced into the source treatment tank  400 , conditioned by the hydro turbulator system  100  and then drained while additional source fluid  405  is added to the source treatment tank  400 . The operation of the hydro turbulator system  100  on the source fluid  405  depends on the control of the flow through the source fluid inlet  420  and the source treatment tank outlet  444 . 
     A top view of the embodiment of the hydro turbulator system  100  and the source treatment tank  400  from  FIG.  10    is shown in  FIG.  11   . As illustrated, the hydro turbulator system  100  sits near the center of the source treatment tank  400 . The hydro turbulator system  100  is surrounded by wastewater held in the source treatment tank  400 . A treatment media, such as a moving bed biofilm reactor (MBBR), floats in the tank surrounding the hydro turbulator system  100 . Discharge from the hydro turbulator system  100  is expelled from the discharge ports  172  located in the discharge extension  170  to help circulate the treatment media in the source fluid  405  in a circular pattern around the tank while also adding aeration and microbubbles that mixes the treatment media to improve treatment. 
     An elevation side view of an alternative embodiment including the hydro turbulator system  100  installed in a rectangular treatment tank  600  is illustrated in  FIG.  12   . Wastewater  605  is held within the treatment tank  600  to the height of a wastewater level  606 . A level control  615  (see  FIG.  13   ) may be used to monitor and control the wastewater level  606 . The rectangular treatment tank  600  includes a treatment tank inlet  620  for allowing wastewater to enter the treatment tank  600  and a treatment tank outlet  625  for allowing wastewater to be discharged from the treatment tank  600 . Fixed treatment media  608 , such as a membrane bioreactor (MBR), is positioned within the treatment tank  600  and supported by a treatment media support  609 . The treatment tank  600  may also include an overflow valve  632  to allow excess wastewater  605  to be removed from the treatment tank  600  when the wastewater level  606  gets too high. 
     A suction pipe increaser  182  is attached to the bottom duct  116 , acting as inlet, of the hydro turbulator system  100 . A suction extension pipe  180  is connected to the suction pipe increaser  182  and extends between the hydro turbulator system  100  and debris guard apparatus  655  positioned within the treatment tank  600 . This piping system creates flow through the fixed treatment media  608  using discharge flow to push through the fixed treatment media  608  and suction to pull wastewater through the fixed treatment media  608 . 
       FIG.  13    is a top view of treatment tank  600  illustrated in  FIG.  12   . As shown, the hydro turbulator system  100  is positioned near a corner of the treatment tank  600 . The discharge extension  170  extends along on wall of the treatment tank  600 . The suction extension pipe  180  initially extends along another wall of the treatment tank, perpendicular to the discharge extension  170 . The suction extension pipe  180  then makes an approximately 90 degree turn to follow the wall of the treatment tank  60  opposite to the wall along which the discharge extension  170  extends so that the a portion of the suction extension pipe  180  is parallel to the discharge extension  170 . Fluid is discharged from the discharge extension  170  so that it flows through the fixed treatment media and to the suction extension pipe  180 . One or more debris guard pipes  656  of the debris guard apparatus  655  extend from the suction extension pipe  180 . 
       FIG.  14    shows a cross-sectional elevation view of the rectangular treatment tank  600  shown in  FIG.  12   . This view shows the end of the rectangular treatment tank  600  that includes the hydro turbulator system  100 . Since the hydro turbulator system  100  is operating in up flow, the top duct  112  acts as an outlet for the hydro turbulator system  100 . As shown, the discharge extension  170  extends from the top duct  112  of the hydro turbulator system  100  near or above the wastewater level  606  in the treatment tank  600 . One or more discharge pipe downcomers  171  extend vertically from the discharge extension toward the bottom of the treatment tank  600 . A series of discharge ports  172  are positioned on the discharge pipe downcomers  171  and are in fluid communication with the discharge extension  170 . Fluid from the discharge extension  170  is expelled from the discharge ports  172 , allowing fluid that has been processed through the hydro turbulator system to be recirculated in the treatment tank  600 . 
       FIG.  15    is a cross-sectional elevation view of the opposite end of the rectangular treatment tank  600  than the end shown in  FIG.  14    is illustrated in  FIG.  15   . This view shows the end of the rectangular treatment tank  600  (see  FIG.  12   ) that includes the debris guard apparatus  655 . As shown, the suction extension pipe  180  extends near the bottom surface of the treatment tank  600  and debris guard pipes  656  of the debris guard apparatus  655  extend vertically from the suction extension pipe  180 . The debris guard pipes  656  prevent large pieces of debris from being suctioned into the suction extension pipe  180  and being returned into the hydro turbulator system  100 . 
     An exemplary impeller system  120  and section of volute  104  suitable for any of the embodiments disclosed herein is shown in  FIG.  16 A . This system includes drive impeller  126  and one or more agitations impellers  124  and/or  125 . As shown, a ring  190  may be installed within the volute  104  near the position of the drive impeller  126  to decrease the hydraulic diameter near the drive impeller  126 . This allows for efficient flow of fluid through the hydro turbulator system  100 . In contrast to the drive impeller  126 , there is no ring  190  near the first agitation impeller  124  and/or the second agitation impeller  125  so that there is a greater space between the blade ends of the first agitation impeller  124  and the second agitation impeller  125  and the walls of the volute  104  than between the blade ends of the drive impeller  126  and the ring  190 . This open space between the top impeller  124  and the middle impeller  125  and the walls of the volute  104  allows for greater agitation (e.g., vortex flow radially outward of the impeller blades) of the fluid proximate the impellers  124 ,  125 . 
     As illustrated in  FIG.  16 B , a fluid flow path through the impeller system and volute may have a constant or varying hydraulic diameter along portions of its length. At some portions, the hydraulic diameter may be equal to a volute wall diameter  192  that spans the walls of the volute  104 . In other portions, the hydraulic diameter may be equal to a ring diameter  193  that is defined between surfaces of a ring  190  that is inserted within the volute  104  near the drive impeller  126 . In such instances, because the ring  190  is inserted within the volute  104 , the hydraulic diameter at the ring (e.g., the ring diameter  193 ) may be less than the hydraulic diameter of the volute (e.g., the volute diameter  192 ). 
     In addition to the one or more hydraulic diameters along the length of the fluid flow path through the impeller system and volute, each of the impellers  124 ,  125 ,  126  has a diameter defined by the span of the blades of the impeller  124 ,  125 ,  126 . The first impeller  124  defines a first agitation impeller diameter  194 . The second agitation impeller  125  defines a second impeller diameter  195 . And, the drive impeller  126  defines a drive impeller diameter  196 . In some embodiments, each of the impeller diameters  194 ,  195 ,  196  may be equal. However, in other embodiments, the impeller diameters  194 ,  195 ,  196  may be varied so that each impeller diameter is different or so that two of the impeller diameters are the same and one of the impeller diameters is varied. 
     Preferably, the drive impeller diameter  196  is slightly less than, but almost equal to the hydraulic diameter of the fluid flow path at the location of the drive impeller (e.g., the ring diameter  193 ). In some embodiments, the ratio of the drive impeller diameter  196  to the hydraulic diameter is greater than 90% and preferably greater than 95%. Also preferably, the ratio of the first agitation impeller diameter  194  to the hydraulic diameter of the fluid flow path at the location of the first agitation impeller and/or the ratio of the second agitation impeller diameter  125  to the hydraulic diameter of the fluid flow path at the location of the second agitation impeller is/are less than the ratio of the drive impeller diameter  196  to the hydraulic diameter of the fluid flow path at the location of the drive impeller. In one example, the ratio of the first agitation impeller diameter  194  to the hydraulic diameter at the location of the first agitation impeller and/or the ratio of the second agitation impeller diameter  125  to the hydraulic diameter at the location of the second agitation impeller are each less than 90% and preferably less than 80%. For example, the first and/or second agitation impellers may have a diameter of about 150 mm and the hydraulic diameter at those locations may be about 200 mm, for a ratio of about 75%. Additionally or alternatively, the drive impeller may have a diameter of about 150 mm and the hydraulic diameter at the location of the drive impeller may be about 160 mm for a ratio of about 94%. 
     In some embodiments, the hydro turbulator system  100  may not include a ring  190 . Instead, the drive impeller  126  may be bigger than the first agitation impeller  124  and/or the second agitation impeller  125  so that the ratio of the drive impeller diameter  196  to the hydraulic diameter is greater than that of the agitation impeller(s). In some examples, the ratio of the drive impeller diameter  196  to the hydraulic diameter wall may be at least 90%, 90% to 95%, or, in some instances, greater than 95%. In other embodiments, instead of using a ring  190 , the hydraulic diameter may be decreased near the drive impeller  126  by a reduced volute wall diameter  192  at the location of the drive impeller  126  than at the first agitation impeller  124  and/or the second agitation impeller  125 . In these embodiments, the hydraulic diameter may remain equal to the volute wall diameter  192  throughout the length of the volute, but the volute wall diameter  192  varies. 
     In some embodiments, one or more of impellers  124 ,  125 , and/or  126  may have blades with a different pitch angle than blades of another one of impellers  124 ,  125 , and/or  126 . As an example, the pitch of the drive impeller  126  may be greater than the pitch of the first agitation impeller  124  and/or the second agitation impeller  125 . For example, the drive impeller  126  may have a lower pitch angle than that of the first agitation impeller  124  and/or the second agitation impeller  125 . Advantageously, such an arrangement can reduce the static fluid pressure in a portion of the fluid flow path between the drive impeller and the one or more agitation impellers to a point below the vapor pressure of the fluid, so as to induce cavitation (e.g., boiling) in the reduced-pressure region. 
     Alternatively, the drive impeller may have a greater pitch angle than the first and/or second agitations impellers so as to, for example, provide back-pressure on the drive impeller and/or induce more cavitation downstream of the one or more agitation impellers. As explained above, the agitation impeller(s) preferably cause cavitation which can promote the off-gas of volatile chemicals from the liquid. 
     One or more of impellers  124 ,  125 , and/or  126  may differ from another one of impellers  124 ,  125 , and/or  126  in terms of diameter, material, blade chord length, rake, cupping, type of pitch (true vs. progressive) and/or number of blades. 
       FIG.  16 A  and  FIG.  16 B  and the accompanying description are suitable for a hydro turbulator system  100  in the up flow configuration and/or in the down flow configuration. 
     Although embodiments described above may include an enclosed treatment tank, the hydro turbulator system  100  may also be operated in an open body of water such as a pond, lake, or a lagoon. The hydro turbulator system  100  may float on the surface of the water or be mounted in a fixed position within the body of water. In a lagoon wastewater system, the hydro turbulator system may provide cell to cell transfer. 
     As already described, for example in  FIGS.  3 - 7   , in some embodiments, the hydro turbulator system  100  may operate as a once-through system. In one example the hydro turbulator system  100  may act as a dissolved oxygen return. The hydro turbulator system  100  floats or is permanently installed near the leaving effluent location in a lagoon treatment system. The hydro turbulator system  100  is operated in the up flow configuration and transfers dissolved oxygen rich effluent from the final stage of the treatment system to a piped discharge area near the location of the incoming wastewater for treatment. The hydro turbulator system  100  can transfer, mix, aerate and increase the dissolved oxygen level to improve the treatment process and increase wastewater contact time and travel velocity in the lagoon treatment system. 
     In another once-through application, the hydro turbulator system  100  operates to provide off gas and aeration for source fluid and/or rain water. The hydro turbulator system  100  may be operated in hyper turbulation mode and applied for groundwater or surface water remediation for contaminated water or for raw water pretreatment in a potable water treatment plant. The hydro turbulator system  100  off gases CO 2 , VOCs, and H 2 S while mixing and generating oxygen rich micro bubbles for aeration. The hydro turbulator system  100  may transfer and discharge conditioned water into a holding tank that may or may not include filtering media to help strip CO 2 , VOCs, and H 2 S for capture and air treatment of the off gas. 
     In another application, one or more hydro turbulator systems  100  may be installed in a floating assembly and moved over a pond, lake, or lagoon with high levels of sludge or biological growth that has caused the water and or wastewater in the pond, lake, or lagoon to become anaerobic. The hydro turbulator systems  100  may be semi-submersed and configured in either an up flow configuration horizontally and/or straight down to blast, mix, and aerate the water or sludge to increase biological treatment performance. 
     The hydro turbulator system  100  may also be used in recirculation applications, as shown, for example, in  FIGS.  10 - 15   . In one embodiment, the hydro turbulator system  100  may be installed in a round or rectangular, in ground or above ground, metal, composite, or concrete tank. The recirculating system may be used for treatment and the hydro turbulator system  100  may work with and complement the treatment media that is used in the treatment process. The inlet of the hydro turbulator system  100  is connected to the debris guard and acts in suction to draw in the source fluid. The outlet of the hydro turbulator system  100  may include piping and multiple piped outlets to mix the source fluid while providing aeration and increased dissolved oxygen for improved treatment performance. 
     For above ground tanks, the hydro turbulator system  100  may be applied dry and external, but close coupled to the tank. The hydro turbulator system may alternatively be configured in up flow and mounted inside the treatment tank for discharge to mix and/or aerate the floating treatment media, such as MBBR. A circular tank with a centrally located debris guard and one or more hydro turbulator systems  100  with discharge piping and nozzles configured may be used to promote a circular flow for mixing the aerated discharge, supplying increased dissolved oxygen to improve treatment efficiency. 
     In some embodiments, multiple hydro turbulator systems  100  may be used within a large rectangular tank and partitions and/or separation screens may be used to increase the travel distance for improved treatment performance. 
     The tanks used for recirculation may include fixed media, MBR, or flowing sheet media to treat the source fluid or wastewater processed in the tank. The media may benefit from the push and pull of the aerated flow of the fluid within the tank and through the media. The hydro turbulator system  100  provides piped and submerged suction that pulls from one side of the media and provides discharge outflow flowing directly into the media, aerating the treatment microbes in the media. The suction and discharge flows may be arranged in crossflow, horizontal through the media; down flow, flowing downward through the media with microbubbles; or in up flow, flowing upward through the media with bubbles. 
     In some embodiments, where source fluid or wastewater to be treated is heavily contaminated, two or more hydro turbulator system  100  may be piped in series with a transfer tank between the hydro turbulator systems  100 . A speed and level control system may be used to maintain the flow through entire system at about 600 gallons per minute. 
     The following numbered clauses set out specific embodiments that may be useful in understanding the present invention: 
     1. A hydro turbulator system comprising: 
     a volute including a length, wherein said volute includes a first duct and a second duct, and wherein one of said first duct and said second duct are configured to allow fluid to enter the volute and the other is configured to allow fluid to exit the volute; 
     an impeller system positioned within the volute wherein said impeller system includes a drive impeller having a diameter and a first agitation impeller having a diameter; 
     wherein said drive impeller and said first agitation impeller are positioned in series along a fluid flow path extending through the volute between the first duct and the second duct, and wherein rotation of said drive impeller and said first agitation impeller create successive zones of high pressure and low pressure along a length of the fluid flow path; 
     one or more motors operationally connected to said impeller system, wherein operation of the one or more motors is configured to rotate the drive impeller and the first agitation impeller; and 
     i. wherein a ratio of the diameter of the drive impeller to a hydraulic diameter of the fluid flow path at the drive impeller is greater than a ratio of the diameter of the first agitation impeller to a hydraulic diameter of the fluid flow path at the first agitation impeller, or 
     ii. wherein the drive impeller differs from the first agitation impeller by diameter, blade pitch, and/or number of blades. 
     2. The hydro turbulator system of clause 1, further comprising: 
     a ring positioned within the volute around the drive impeller; and wherein said ring defines the hydraulic diameter at the drive impeller. 
     3. The hydro turbulator system of any preceding clause, further comprising: 
     a debris guard surrounding the bottom duct of the hydro turbulator system, wherein said debris guard is configured to prevent large particles from entering said hydro turbulator system. 
     4. The hydro turbulator system of any preceding clause, wherein said impeller system may be operated in an up flow configuration in which said first duct is a bottom duct which acts as an inlet and said second duct is a top duct which acts as an outlet for said volute; and 
     wherein said impeller system may be operated in a down flow configuration in which the bottom duct acts as an outlet and said top duct acts as an inlet for said volute. 
     5. The hydro turbulator system of any preceding clause, wherein when the impeller system is configured in up flow configuration, fluid entering the hydro turbulator system may be lifted over a dike, a bank, or a flume while also off-gassing volatile chemicals and adding dissolved oxygen to the fluid.
 
6. The hydro turbulator system of any preceding clause, further comprising:
 
     a driveshaft operationally attached to said drive impeller and said first agitation impeller so that rotation of said driveshaft rotates said drive impeller and said first agitation impeller; 
     a motor shaft attached to said motor and rotatable upon operation of the said motor; and 
     a coupling connecting said motor shaft to said drive shaft so that rotation of said motor shaft causes rotation of said drive shaft. 
     7. The hydro turbulator system of clause 6, further comprising: 
     a motor mounting assembly coupled to an end of said volute, wherein said motor is supported by said motor mounting assembly; and 
     wherein said motor mounting assembly provides access to said coupling connecting said motor shaft to said driveshaft. 
     8. The hydro turbulator system of any preceding clause, further comprising: 
     a casing, wherein said casing surrounds at a least a portion of said volute; and wherein said volute is slidable within said casing. 
     9. The hydro turbulator system of clause 8, further comprising: 
     an internal support base positioned within said casing; and 
     wherein said volute is supported within the casing by said internal support base. 
     10. The hydro turbulator system of claim 1, wherein said impeller system includes a second agitation impeller, and wherein said second agitation impeller is positioned in series with said drive impeller and said first agitation impeller along the fluid flow path.
 
11. A fluid treatment system comprising:
 
     a source fluid tank including a source fluid to be treated; 
     a hydro turbulator system in fluid communication with said source fluid tank, wherein said hydro turbulator system includes:
         a volute, wherein said volute includes a top duct and a bottom duct, and wherein said top duct and said bottom duct are configured to allow fluid to enter and exit the volute;   an impeller system positioned within the volute wherein said impeller system includes a first impeller and a second impeller;   wherein rotation of said first impeller and said second impeller is configured to create successive zones of high pressure and low pressure within the volute; and       

     a gas capture tank in fluid communication with said hydro turbulator system to receive fluid discharged from said hydro turbulator system, and wherein the gas capture tank includes treatment media configured to remove unwanted chemicals from the fluid discharged from said hydro turbulator system. 
     12. The fluid treatment system of clause 11, further comprising: 
     a gas discharge blower attached to said gas capture tank; 
     wherein said gas discharge blower removes off gassed volatile chemicals from said gas capture tank. 
     13. The fluid treatment system of any one of clause 11 or 12, wherein said first impeller and said second impeller are axially aligned.
 
14. The fluid treatment system of any one of clauses 11-13, wherein the hydro turbulator system is positioned exterior to said source fluid tank and said gas capture tank.
 
15. The fluid treatment system of any one of clauses 11-14, wherein the hydro turbulator system is at least partially submerged in the source fluid of said source fluid tank.
 
16. The fluid treatment system of clause 15, further comprising:
 
     a debris guard surrounding the bottom duct of the hydro turbulator system, wherein said debris guard is configured to prevent large particles from entering said hydro turbulator system. 
     17. A fluid treatment system comprising: 
     a fluid treatment tank including a fluid to be treated; 
     a hydro turbulator system at least partially submerged in the fluid within said fluid treatment tank, wherein said hydro turbulator system includes:
         a volute, wherein said volute includes a top duct and a bottom duct, and wherein said top duct and said bottom duct are configured to allow fluid to enter and exit the volute;   an impeller system positioned within the volute wherein said impeller system includes a first impeller and a second impeller;   wherein rotation of said first impeller and said second impeller is configured to create successive zones of high pressure and low pressure within the volute;       

     a discharge extension extending from one of said top duct and said bottom duct of said hydro turbulator system, wherein fluid within said hydro turbulator system is discharged into said fluid treatment tank from said discharge extension; 
     a suction extension pipe extending from one of said top duct and said bottom duct of said hydro turbulator system, wherein at least a portion of said suction extension pipe is substantially parallel to said discharge extension; and wherein said suction extension pipe is configured to provide suction to pull fluid into said hydro turbulator system; 
     fixed treatment media positioned between at least a portion of said discharge extension and a portion of said suction extension pipe; and 
     wherein fluid discharged from said discharge extension is pulled by said suction extension pipe so that the discharged fluid flows through said fixed treatment media. 
     18. The fluid treatment system of clause 17, further comprising: 
     at least one debris pipe extending from said suction extension pipe, wherein said debris pipe prevents large particles within the fluid from entering the suction extension pipe. 
     19. The fluid treatment system of any one of clause 17 or 18, 
     wherein the hydro turbulator system may be operated in an up flow configuration in which said top duct is fluidly connected to said discharge extension and said bottom duct is fluidly connected to said suction extension pipe; and 
     wherein the hydro turbulator system may be operated in a down flow configuration in which said top duct is fluidly connected to said suction extension pipe and said top duct is fluidly connected to said discharge extension. 
     20. The fluid treatment system of any one of clauses 17-19, wherein said first impeller and said second impeller are axially aligned. 
     While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.