Patent Publication Number: US-2023149864-A1

Title: Venturi Aspirator THM/VOC Removal System

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 63/278,546, filed Nov. 12, 2021, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention is directed to an improved post-treatment aeration system to reduce trihalomethanes (THMs) and other volatile organic compounds (VOCs) in potable water systems. 
     Description of Related Art 
     High levels of THMs and VOCs that are present in chlorinated potable water systems need to be reduced to conform to government regulations. Traditional “air stripping” methods currently in use require additional equipment and substantial energy use. Examples of such equipment are “counter-current packed columns”, air diffusers, and spray aerators. Although these methods are somewhat effective, a need exists for a system that is lower in initial capital cost, lower in installation cost, lower in maintenance cost, and lower in energy use. 
     It is therefore an object of the present invention to provide an effective post-treatment aeration system to reduce trihalomethanes (THMs) and volatile organic compounds (VOCs) in potable water systems that has lower total life cycle cost than customary systems. 
     It is a further object of the present invention to provide a sub-system that can be added to existing trihalomethane (THM) &amp; volatile organic compound (VOC) reducing systems to provide greater overall efficiency. 
     SUMMARY OF THE INVENTION 
     In one non-limiting embodiment, the present invention includes a venturi type aspirator with an upstream pump. The primary flow of water is from a storage tank, through the pump, through the venturi aspirator where it assimilates air (or oxygen), and is then returned to the storage tank. The inlet and outlet connection to the water tank may be at the same elevation or different elevations, as best suits the specific application. Air (or oxygen) is introduced into the primary water flow stream through venturi action in the aspirator. An optional check valve is provided to prevent backflow in the event of pump failure. An optional filter is provided to decontaminate the incoming air (or oxygen). An auxiliary conduit connection is provided to allow introducing sanitizing fluid (gas or liquid) via the venturi aspirator intake port. 
     In another non-limiting embodiment, the present invention includes a venturi type aspirator with an upstream pump, and downstream static mixer. The primary flow of water is from a storage tank, through the pump, the venturi aspirator, the static mixer, and then returned to the storage tank. The inlet and outlet connection/conduits to the water tank may be at the same elevation or different elevations, as best suits the specific application. Air (or oxygen) is introduced into the primary water flow stream through venturi action in the aspirator. The gas bubbles at this point are relatively large and present a relatively small surface area with the water. As the gas and water mixture passes through the static mixer the bubbles are dispersed and become relatively small, presenting a much larger total surface area to the water, thereby enhancing trihalomethane (THM) and volatile organic compound (VOC) removal. An optional check valve is provided to prevent backflow in the event of pump failure. An optional filter is provided to decontaminate the incoming air. An auxiliary conduit connection is provided to allow introducing sanitizing fluid via the venturi aspirator intake port. 
     A further non-limiting embodiment uses an extension on the inlet conduit to collect the inlet flow from a specific locations \in the storage tank, and/or an extension on the outlet conduit to discharge the outlet flow to a specific location in the storage tank. In yet a further non-limiting embodiment, an extension with multiple ports can be on the exit conduit to more widely distribute the discharge mixture over a larger area of the storage tank. 
     In certain non-limiting embodiments, the present invention uses extended piping to allow water to be drawn from, and returned to, the storage tank without the need to penetrate the tank walls. This is especially desirable in retrofit applications where the storage tank may be in use, and filled with water, during the installation process. 
     In a further non-limiting embodiment, the pump, venturi aspirator and static mixer are inside the storage tank on a platform supported by the storage tank walls, ceiling, or other fixed structure. In another non-limiting embodiment, the pump, venturi aspirator and static mixer are inside the storage tank, atop a platform which floats on the water. 
     In some non-limiting embodiments, the present invention uses flexible, or hinged, inlet and/or outlet conduit attached to the floating platform, which automatically maintains a constant depth of submersion of the inlet and/or outlet regardless of water level inside the tank. The inlet and outlet may be at the same depth relative to the water surface, or may be at different depths relative to the water surface, as best suits the specific application. 
     Another non-limiting embodiment uses an automatic air release valve to reduce the amount of excess air introduced into the storage tank. 
     In certain non-limiting embodiments, the present invention uses a single pump, multiple venturi aspirators, multiple static mixers, and several valves to select an input from different locations on the storage tank and/or select an output to different locations on the storage tank. The specific venturi aspirators and static mixers are selected using either manually operated or automated in-line valves. 
     Another non-limiting embodiment, the present invention uses a single pump, single venturi aspirator, single static mixer, and several valves to select an input from different locations on the storage tank and/or select an output to different locations on the storage tank. The specific venturi aspirators and static mixers are selected using either manually operated or automated in-line valves. 
     In another non-limiting embodiment, the venturi aspirator, with or without a static mixer, is installed in a conventional spray nozzle system between the pump and spray nozzle to augment the trihalomethane (THM) and volatile organic compound (VOC) reduction provided by the spray nozzle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1 A  is a plan view of the present invention with the venturi aspirator shown in section view. In all FIGS. the tank walls are considered to be transparent to more clearly show the apparatus inside the tank as well as outside the tank. 
         FIG.  1 B  is a front elevation view of the present invention with the venturi aspirator shown in section view. 
         FIG.  1 C  is a side elevation view of the present invention with the venturi aspirator shown in section view. 
         FIG.  2 A  is a plan view of the present invention with the venturi aspirator and a static mixer shown in section view. 
         FIG.  2 B  is a front elevation view of the present invention with the venturi aspirator and static mixer shown in section view. 
         FIG.  2 C  is a side elevation view of the present invention with the venturi aspirator and static mixer shown in section view. 
         FIG.  3    is a plan view of the present invention with an extension on the inlet conduit to collect the inlet flow from a specific locations \in the storage tank, and/or an extension on the outlet conduit to discharge the outlet flow to a specific location in the storage tank. 
         FIG.  4    is a plan view of the present invention with an extension with multiple ports on the exit conduit to more widely distribute the discharge mixture over a larger area of the storage tank. 
         FIG.  5 A  is a plan view of the present invention with extended piping to allow water to be drawn from, and returned to, the storage tank without the need to penetrate the tank walls. 
         FIG.  5 B  is a front elevation view of the present invention with extended piping to allow water to be drawn from, and returned to, the storage tank without the need to penetrate the tank walls. 
         FIG.  5 C  is a side elevation view of the present invention with extended piping to allow water to be drawn from, and returned to, the storage tank without the need to penetrate the tank walls. 
         FIG.  6 A  is a plan view of the present invention with the pump, venturi aspirator and static mixer inside the storage tank, on a platform supported by the storage tank walls, ceiling, or other fixed structure. 
         FIG.  6 B  is a front elevation view of the present invention with the pump, venturi aspirator and static mixer inside the storage tank, on a platform supported by the storage tank walls, ceiling, or other fixed structure. 
         FIG.  6 C  is a side elevation view of the present invention with the pump, venturi aspirator and static mixer inside the storage tank, on a platform supported by the storage tank walls, ceiling, or other fixed structure. 
         FIG.  7 A  is a plan view of the present invention with the pump, venturi aspirator and static mixer inside the storage tank, atop a suitable device floating on the water. 
         FIG.  7 B  is a front elevation view of the present invention with the pump, venturi aspirator and static mixer inside the storage tank, atop a suitable device floating on the water. 
         FIG.  7 C  is a side elevation view of the present invention with the pump, venturi aspirator and static mixer inside the storage tank, atop a suitable device floating on the water. 
         FIG.  8    is a front elevation view of the present invention that uses flexible inlet and flexible outlet conduit attached to a floating apparatus which automatically maintains a constant depth of submersion of the inlet and outlet regardless of water level inside the tank. 
         FIG.  9    is a front elevation view of the present invention that uses an automatic air release valve to reduce the amount of air introduced into the storage tank. 
         FIG.  10    is a front elevation view of the present invention that uses a single pump, two venturi aspirators, two static mixers, and four valves to select an input from either of two different locations on the storage tank and/or select an output to either of two different locations on the storage tank. In this view the water level in the tank is low. 
         FIG.  11    is a front elevation view of the present invention that uses a single pump, two venturi aspirators, two static mixers, and four valves to select an input from either of two different locations on the storage tank and/or select an output to either of two different locations on the storage tank. In this view the water level in the tank is high. 
         FIG.  12    is a front elevation view of the present invention that uses a single pump, single venturi aspirator, single static mixer, and four valves to select an input from either of two different locations on the storage tank and/or select an output to either of two different locations on the storage tank. In this view the water level in the tank is low. 
         FIG.  13    is a front elevation view of the present invention that uses a single pump, single venturi aspirator, single static mixer, and four valves to select an input from either of two different locations on the storage tank and/or select an output to either of two different locations on the storage tank. In this view the water level in the tank is high. 
         FIG.  14 A  is side section view of a typical spray aerator system currently in use for trihalomethane (THM) and volatile organic compound (VOC) reduction. 
         FIG.  14 B  is side section view of a spray aerator system for trihalomethane (THM) and volatile organic compound (VOC) reduction with the addition of the venturi aspirator and static mixer of the present invention added to augment trihalomethane (THM) and volatile organic compound reduction. 
     
    
    
     DESCRIPTION OF THE INVENTION 
     For purposes of the following detailed description, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. Moreover, other than in any operating examples, or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term “about”. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. 
     Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard variation found in their respective testing measurements. 
     Also, it should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of “1 to 10” is intended to include all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value of equal to or less than 10. 
     Further, the terms “upper,” “lower,” “right,” “left,” “vertical,” “horizontal,” “top,” “bottom,” “lateral,” “longitudinal,” and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume alternative variations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the specification, are simply exemplary embodiments of the invention. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting. 
     In this application, the use of the singular includes the plural and plural encompasses singular, unless specifically stated otherwise. In addition, in this application, the use of “or” means “and/or” unless specifically stated otherwise, even though “and/or” may be explicitly used in certain instances. 
     Referring to  FIGS.  1 A,  1 B and  1 C , the THM and VOC reduction components are shown mounted alongside of a potable water storage tank  20  containing water  96  containing THMs and/or VOCs. The direction of water flow is from the storage tank  20 , through connecting inlet conduit  30 , through a pump  40 , through a venturi aspirator  50 , and then returns to the storage tank through an outlet conduit  70 . Pump  40  may be operated by any common power source such as an electric motor or gasoline engine. The power source is not shown for clarity. Air is drawn into the venturi aspirator  50  from the surrounding atmosphere through air inlet port  88 . The air passes through filter  84  which prevents particulate matter from entering the system. The filtered air then passes through check valve  82  which prevents reverse water flow out of the venturi inlet port  80  when the pump is not operating or operating at degraded performance. The return flow includes air mixed with the water  96  resulting in a discharge including relatively large air bubbles  92 . As shown, both the inlet conduit  30  and outlet conduit  70  of the system are below the water surface  90 . While it is essential that the inlet be below the water surface  90 , the outlet conduit  70  can be at any level, including above the water surface  90 . The storage tank  20  also includes an inlet port  22  connecting the tank to a source of water to be treated and an outlet port  24  to supply treated water as necessary. 
     Referring to  FIGS.  2 A,  2 B and  2 C , the THM and VOC reduction system of  FIGS.  1 A,  1 B and  1 C  is modified to include a static mixer  60 . The THM and VOC reduction components are shown mounted alongside of a potable water storage tank  20  containing water  96  containing THMs and/or VOCs. The direction of water flow is from the storage tank  20 , through connecting conduit  30 , through a pump  40 , through a venturi aspirator  50 , through a static mixer  60 , and then returns to the storage tank through conduit  70 . Pump  40  may be operated by any common power source such as an electric motor or gasoline engine. The power source is not shown for clarity. Air is drawn into the venturi from the surrounding atmosphere through air inlet port  88 . The air passes through filter  84  which prevents particulate matter from entering the system. The filtered air then passes through check valve  82  which prevents reverse water flow out of the venturi inlet port  80  when the pump is not operating or operating at degraded performance. By using static mixer  60  the air bubbles  94  mixed with the water  96  are much smaller and present a larger surface area which enhances THM and VOC reduction. As shown, both the inlet conduit  30  and outlet conduit  70  of the system are below the water surface  90 . While it is essential that the inlet conduit  30  be below the water surface  90 , the outlet conduit  70  can be at any level, including above the water surface  90 . The storage tank  20  also includes an inlet port  22  connecting the tank to a source of water to be treated and an outlet port  24  to supply treated water as necessary. 
     Referring to  FIG.  3   , the system of  FIGS.  2 A,  2 B and  2 C  is modified to include inlet conduit extension  32  connected to inlet conduit  30 , and outlet conduit extension  79  connected to outlet conduit  70 , to allow collecting the inlet flow and discharging the outlet flow to specific locations in the storage tank  20 . 
     Referring to  FIG.  4   , the system of  FIGS.  2 A,  2 B and  2 C  is modified to include a perforated conduit extension  72  connected to outlet conduit  70  to allow discharging and dispersing the outlet flow bubbles  94  over a larger area of the storage tank  20 . Air bubbles  94  are not shown for clarity. 
     Referring to  FIGS.  5 A,  5 B, and  5 C , the system of  FIGS.  2 A,  2 B and  2 C  is modified to route the inlet conduit  30  and outlet conduit  70  over the storage tank  20  sidewall without the need to penetrate the sidewall of the storage tank  20 . 
     Referring to  FIGS.  6 A,  6 B, and  6 C , the system of  FIGS.  2 A,  2 B and  2 C  is installed inside the storage tank  20  mounted on support  74 , support  76  and platform  72 . The platform  72  is fastened to the storage tank  20  using suitable and common methods such as welding or bolting, which are not shown for clarity. The platform  72  and supports  74  and  76  are typically made of steel but may be any suitable material. 
     Referring to  FIGS.  7 A,  7 B and  7 C , the system of  FIGS.  2 A,  2 B and  2 C  is installed inside the storage tank  20  mounted atop a suitable platform  78  floating on the surface  90  of the water  96  using supports  74  and  76 . It is appreciated that the platform  78  acts as a flotation device and can be of any suitable design that will support the weight of the components and flexible inlet conduit  30  and outlet conduit  70 . The purpose of the flotation platform  78  is to maintain a fixed relationship between the water surface  90  and depth of the inlet and outlets of the flexible conduits  30  and  70 . 
     It should be understood that it may be desirable to use only one floating flexible conduit and one fixed conduit not connected to the flotation platform  78  as best suits the specific application. 
     The floating platform  78  may be wood, hollow metal, hollow plastic or other suitable material. The supports  74  and  76  may be wood, metal, plastic or other suitable material affixed using suitable and common methods, which are not shown for clarity. 
     Referring to  FIG.  8   , the THM and VOC reduction components of the system of  FIGS.  2 A,  2 B and  2 C  are installed outside the storage tank  20 . The inlet conduit  30  and outlet conduit  70  are connected to flexible conduits  240  and  250  respectively through the tank  20  wall. Flexible conduits  240  and  250  are attached to a suitable platform  270  floating on the water via supports  272  and  274  respectively. The floating platform  270  may be wood, hollow metal, hollow plastic or other suitable material. The supports  272  and  274  may be wood, metal, plastic or other suitable material affixed using suitable and common methods, which are not shown for clarity. 
     Referring to  FIG.  9   , a further non-limiting embodiment of the present invention modifies the system of  FIGS.  2 A,  2 B and  2 C  by adding an automatic air release valve  280  to reduce the amount of air introduced into the storage tank  20 . 
     Referring to  FIG.  10   , in a further non-limiting embodiment a single pump  40  operates two separate venturi aspirators  50  and  52  with their associated static diffusers  60  and  62 . Flow through the system is controlled by valves  180 ,  190 ,  200 , and  210 . These valves are preferably power actuated, such as solenoid operated, pneumatically actuated, or the like, but may be manually operated as well, and may be either of the full open/full closed type or throttling type. In this view the water  96  level in the tank  20  is low and the lower inlet conduit  110  and lower outlet conduit  130  are active. 
       FIG.  10    shows valves of the full open/full closed type. Specifically valves  180  and  200  are fully open, and valves  190  and  210  are fully closed. Flow through the system begins at the inlet conduit  110  attached to the tank  20 , passes through valve  180 , through conduit  120 , through pump  40 , through conduit  150 , through valve  200 , through aspirator  50  where it assimilates air, through static mixer  60 , and returns to the storage tank via outlet conduit  130 , discharging the water  96  containing small air bubbles  94 . Because valves  190  and  210  are fully closed, there is no flow through valve  210 , conduit  160 , venturi aspirator  52 , static mixer  62 , and conduit  170 . 
     Referring to  FIG.  11   , a single pump  40  operates two separate venturi aspirators  50  and  52  with their associated static mixers  60  and  62 . Flow through the system is controlled by valves  180 ,  190 ,  200 , and  210 . These valves are preferably power actuated, such as solenoid operated, pneumatically actuated, or the like, but may be manually operated as well, and may be either of the full open/full closed type or throttling type. In this view the water  96  level in the tank  20  is high and the upper inlet conduit  140  and outlet conduit  170  are active. 
       FIG.  11    shows valves of the full open/full closed type. Specifically valves  180  and  200  are fully closed, and valves  190  and  210  are fully open. Flow through the system begins at the inlet of conduit  140  attached to the tank wall  20 , passes through valve  190 , through conduit  120 , through pump  40 , through conduit  150 , through valve  210 , through conduit  160 , through venturi aspirator  52  where it assimilates air, through static mixer  62 , and returns to the storage tank  20  via outlet conduit  170 , discharging the water containing small air bubbles  94 . Because valves  180  and  200  are fully closed, there is no flow through valve  180  through valve  200 , venturi aspirator  50 , static mixer  60 , and conduit  130 . 
     While this embodiment of the present invention describes flow through either inlet conduit  110  and outlet conduit  130  only, or inlet conduit  140  and outlet conduit  170  only, it should be understood that other combinations of valve positions may be used to provide different flow paths to suit the application. 
     Likewise, it should be understood that the valves  180 ,  190 ,  200 , and  210  may be of the throttling type, allowing partial flow through any of the alternate flow paths. 
     Referring to  FIG.  12   , in another non-limiting embodiment a single pump  40  operates a single venturi aspirator  50  and a single static mixer  60 . Flow through the system is controlled by valves  180 ,  190 ,  212 , and  214 . These valves are preferably power actuated, such as solenoid operated, pneumatically actuated, or the like, but may be manually operated as well, and may be either of the full open/full closed type or throttling type. In this view the water  96  level in the tank is low and the lower inlet conduit  110  and outlet conduit  130  are active. 
       FIG.  12    shows valves of the full open/full closed type. Specifically valves  180  and  212  are fully open, and valves  190  and  214  are fully closed. Flow through the system begins at the inlet conduit  110  attached to the tank  20 , passes through valve  180 , through conduit  120 , through pump  40 , through conduit  150 , through venturi aspirator  50  where it assimilates air, through static mixer  60 , through conduit  170 , through valve  212 , and returns to the storage tank  20  via outlet conduit  130 , discharging the water containing small air bubbles  94 . Because valves  190  and  214  are fully closed, there is no flow through inlet conduit  140  and outlet conduit  172 . 
     Referring to  FIG.  13   , a single pump  40  operates a single venturi aspirator  50  and a single static mixer  60 . Flow through the system is controlled by valves  180 ,  190 ,  212 , and  214 . These valves are preferably power actuated, such as solenoid operated, pneumatically actuated, or the like, but may be manually operated as well, and may be either of the full open/full closed type or throttling type. In this view the water  96  level in the tank is high and the upper inlet conduit  140  and outlet conduit  172  are active. 
       FIG.  13    shows valves of the full open/full closed type. Specifically valves  190  and  214  are fully open, and valves  180  and  212  are fully closed. In this view the water  96  level in the tank  20  is high and the upper inlet conduit  140  and outlet conduit  172  are active. 
     Flow through the system begins at the inlet conduit  140  attached to the tank  20 , passes through valve  190 , through conduit  120 , through pump  40 , through conduit  150 , through venturi aspirator  50  where it assimilates air, through static mixer  60 , through conduit  170 , through valve  214 , and returns to the storage tank via conduit  172 , discharging the water  96  containing small air bubbles  94 . Because valves  180  and  212  are fully closed, there is no flow through inlet conduit  110  and outlet conduit  130 . 
     While this embodiment of the present invention describes flow through either inlet conduit  110  and outlet conduit  130  only, or inlet conduit  140  and outlet conduit  172  only, it should be understood that other combinations of valve positions may be used to provide different flow paths to suit the application. 
     Likewise, it should be understood that the valves  180 ,  190 ,  200 , and  210  may be of the throttling type, allowing partial flow through any of the different flow paths. 
       FIG.  14 A  is front section view of a typical “spray aerator” system currently in use for trihalomethane (THM) and volatile organic compound (VOC) reduction. Flow is through inlet conduit  290 , through pump  40 , through outlet conduit  300 , and through spray nozzle  310  where the water is separated into small droplets and assimilates air, thereby reducing trihalomethane (THM) and volatile organic compound (VOC) levels somewhat before returning to the main body of water  96 . 
       FIG.  14 B  shows a front section view of a further non-limiting embodiment of the present invention, with the addition of a venturi aspirator  50  and static mixer  60  added to augment trihalomethane (THM) and volatile organic compound (VOC) reduction. This modification uses the existing pump and requires virtually no additional power to operate, while substantially improving the effectiveness of the system. 
     Flow is through inlet conduit  290 , through pump  40 , through the venturi aspirator  50 , through the static mixer  60 , through outlet conduit  300 , and through spray nozzle  310  where the water is separated into small droplets and assimilates additional air, further reducing trihalomethane (THM) and volatile organic compound (VOC) levels before returning to the main body of water  96 . 
     Whereas particular embodiments of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention.