Abstract:
Air is mixed with water passing through a liquid feed line. An internal nozzle carried within the feed line includes an exit diameter smaller than the diameter of the feed line for creating a liquid stream for mixing with air from a vent line directed into a mixing chamber within the feed line. Through the force of the nozzle, the aerated water is focused into an exit channel having a flat entrance face and an exit bore diameter greater than that of the internal nozzle.

Description:
FIELD OF THE INVENTION 
   The subject invention pertains to the field of introducing a gas into a liquid, more particularly to the aeration of water. 
   BACKGROUND OF THE INVENTION 
   Bodies of water, such as lakes, ponds, canals, pools, and the like suffer from the growth of algae and other undesirable aquatic biota that lead to the depletion of oxygen and other elements required to sustain life therein. In nature, air is generally absorbed in a body of water through the agitation of surface waters resulting from waves and wind. Smaller bodies of water in stagnant areas often do not have this resource and as a result, the life forms living in such bodies of water often succumb to the absence of oxygen or relocate to other more oxygenated areas. 
   Apparatus for introducing a gas into a liquid is known in the art. Numerous inventors have proposed solutions to these problems. Many of these solutions utilize bubbling aeration pumps or require the use of a plurality of liquid pumps to aerate the water. As discussed more fully below, such systems are inefficient and subject to malfunction. 
   For example, U.S. Pat. No. 4,210,534 to Molvar discloses a system of mixing a gas with wastewater wherein the gas is injected, under pressure, into the water in a mixing chamber, where it is then discharged. This system requires a pump for the wastewater and an additional pump for pressurizing the air for injection. In addition, the air/wastewater mixture is exited through a tapered exit cylinder wherein the velocity of the mixture is increased. 
   U.S. Pat. No. 4,308,138 to Woltman describes a method wherein the water passes through a venturi thereby increasing water velocity and further passing through a barrel that acts as an exit chamber. Air is pulled under vacuum introduced into the water stream. The stream of water passes through the barrel; however, it does not come into contact with the sides of the barrel. The barrel then gradually opens where the air is further mixed with the water before it exists the system. This system does not create sufficient suction to saturate the water with air due to the taper nature of the entrance to the exit cylinder. A further drawback to this system is that cavitation does not occur in the exit cylinder. This is because the water/air mixture passing through the barrel does not substantially come into contact with the walls of the exit cylinder. 
   U.S. Pat No. 4,936,552 to Rothrock utilizes flowing water upstream of a reducing means to create a vacuum thereby pulling ambient air from the atmosphere and introducing it into the flowing wastewater stream. While this system is capable of partial aeration, it cannot attain oxygen levels sufficient to provide the desired results in a lake, pond, canal, pool or the like. 
   U.S. Pat. No. 6,398,194 to Tsai et al. discloses a water-pressure type aeration device utilizing a powerful water pump, which moves water through a distribution head to a plurality of cavitation housings. The plurality cavitation housings are further in fluid communication with surface air. Where water passes into the cavitation housings, it decreases the pressure therein and pulls a vacuum which, in turn, pulls air from the surface. The air is mixed with water wherein it is then expelled from the apparatus through a downward inclined guide element. All of the aforementioned aeration systems suffer from certain shortcomings, some more serious than others. For example, some require the use of more than one pump or moreover, require the use of more than one type of pump. Any of the deficiencies suffered by these devices can result in losses in efficiency and ultimately result in economic losses. Accordingly, the following disclosure describes improvements in the art of water aeration. 
   All documents and publications cited herein are incorporated by reference in their entirety, to the extent not inconsistent with the explicit teachings set forth herein. 
   BRIEF SUMMARY OF THE INVENTION 
   An apparatus and method for the introduction of a gas into a liquid includes a liquid supply, a liquid feed tube, a reducing means, a vent line, a mixing chamber, and an exit cylinder. 
   Liquid is supplied under pressure from the liquid supply through the liquid feed tube. As liquid passes through the liquid feed line it is passed through a reducing means where the velocity is increased. The exit of the reducing results in a high speed stream of water narrower than the diameter of the exit cylinder. The water passes through the mixing chamber and enters the exit cylinder. The entry of the water stream into the exit cylinder reduces the internal pressure of the mixing cylinder thereby creating a suction. The suction created results in a vacuum effect on the vent line whereby a gas is pulled through the vent tube (generally in communication with ambient air from the surface) and introduced to the water in the mixing chamber. The water/gas combination is passed through the exit chamber where the water stream is subjected to cavitation as the water/air mixture passes along the walls of the exit cylinder. As the system cavitates the gas is mixed with the liquid to the point where the liquid becomes saturated with the gas. The liquid gas mixture is exited from the exit cylinder where the remaining gas is released in the form of bubbles. 
   Accordingly, it is an object of the present invention to provide an improved apparatus for the introduction of gas into a liquid. 
   It is a further object of the present invention to provide an apparatus and method for the aeration of water. 
   It is a still further object of the present invention to provide an improved water aeration apparatus for lakes, ponds, canals, pools and the like. 
   Further objects and advantages of the present invention will become apparent by reference to the following detailed disclosure of the invention and appended drawings wherein like reference numbers refer to the same element, component, or feature. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a full, sectional view of the apparatus in accordance with the present invention. 
       FIG. 2  is a fragmentary perspective view of the apparatus in accordance with the present invention. 
       FIG. 3  is a perspective view of the internal nozzle in accordance with the present invention. 
   

   DETAILED DESCRIPTION OF EMBODIMENTS 
   Referring now to  FIG. 1 , an apparatus for the improved aeration of water is illustrated and generally designated by the reference numeral  10 . 
   The apparatus  10  can be utilized either above or below the surface of the liquid into which a gas is to be introduced. Typically, the apparatus is submerged to a depth at which a gas can be pulled under vacuum through the apparatus. A liquid supply  12 , generally a pump or a pressurized storage tank, supplies liquid under pressure through a liquid feed line  20 . As will come to the mind of those skilled in the art, the liquid supply  12  may include well known pump styles such as bellows, centrifugal, diaphragm, drum, flexible liner, flexible impeller, gear hand, impeller , immersible, peristaltic poston, progressing cavity, and rotary submersible. The liquid feed line enters into a first end  14  of the apparatus  10  and is connected to an internal nozzle  22  concentrically disposed in the mixing chamber  26  of the apparatus  10 . 
   The internal nozzle  22  generally comprises a reducing means  21  in fluid communication with the feed line  20  at a first end and a cylinder  23  at a second end. The internal nozzle  22  is generally concentrically disposed and terminates in the mixing chamber  26 . It is not necessary, however, that the internal nozzle  22  be concentrically disposed in the mixing chamber  26  as it may be disposed in any position in the mixing chamber  26 , so long as the liquid stream flowing from the internal nozzle  22  enters the exit channel  36  unobstructed. Any means to reduce the liquid feed line  20  to a point where the internal nozzle exit  34  has a diameter  40  smaller than the diameter  46  of the liquid feed line  20  will suffice (for example, a series of commercially available reducing adapters). 
   A vent line  24  is connected to and in fluid communication with the mixing chamber  26  at a point more medial of the apparatus  10 . The vent line  24  is in fluid communication with the mixing champer  26  at a first end and a gas supply  25 , generally ambient air at a second end. It is not necessary that the vent line  24  be in communication with ambient air as one or more gas supplies may also be connected to the vent line  24  so that a gas other than air can be introduced into the liquid. 
   The apparatus  10  has an exit cylinder  30  in fluid communication with the mixing chamber  26  at a second end. The exit cylinder  30  has an exit cylinder entrance face  28 , exit channel  36 , and an exit cylinder exit face  32 . The exit cylinder entrance face  28  and exit face  32  are both substantially perpendicular to the flow of liquid passing through the apparatus  10 . This is critical to achieve the desired suction for efficient operation and saturation of the liquid with the gas. 
   As liquid passes through the liquid feed line  20  and into the internal nozzle  22 , the velocity of the fluid flowing there through is increased. 
   As the liquid leaves the internal nozzle exit  34 , a stream of liquid  35  is created (not shown). The stream of liquid passes through the mixing chamber  26  and into the exit cylinder channel  36 . As the liquid passes through the mixing chamber  26 , the internal pressure of the mixing chamber  26 , is reduced resulting in a vacuum. This in turn creates a vacuum on vent tube  24 . The gas, generally ambient air, is pulled from the surface under the vacuum and into the mixing chamber  26 . Where it is intially introduced to the liquid. The liquid/gas mixture is then sent into the exit cylinder  30  wherein it is further mixed to the point of saturation. The exit channel  36  can extend distally past exit face  32  or proximally past the entrance face  28  of the exit chamber  30 . 
   As the gas/liquid mixture passes through the exit cylinder channel  36 , the mixture comes in contact with the walls of the exit cylinder channel  36  and is subjected to cavitation. This contact occurring between the liquid/gas mixture and the walls of the exit cylinder channel  36  is important to the efficient operation of the apparatus  10 . The liquid/gas mixture is then exited from the exit cylinder  30  into the surrounding body of liquid. Excess gas is released in the form of bubbles. 
   To provide a better understanding of a number of terms used in the specification and claims herein, the following definitions are provided. 
   The term cavitation, as used herein, is the creation and subsequent implosion of a gas bubble in a liquid low pressure. 
   The term gas, as used herein, is a form or state of matter in which a material assumes the shape of its container and expands to fill the container, thus having neither definite shape nor volume. Air is included in this definition. 
   The term liquid, as used herein, is a form of state of matter in which a material occupies a definite volume but has the ability to flow and assume the shape of its container. 
   The term pump, as used herein, is any apparatus that is capable of supplying a fluid under pressure. The term saturation, as used herein, is the point at which a liquid contains the maximum quantity of a gas that is possible at a given temperature. 
   Following are examples illustrating procedures for practicing the invention. These examples should be construed to include obvious variations and not limiting. 
   EXAMPLE 1 
   In a preferred embodiment, the distance  44  from the exit of the reduction means  34  to the exit cylinder entrance face  28  is greater than the diameter of the exit cylinder  42 . In addition, the length of the exit cylinder  30  is greater than the diameter  42  of the exit cylinder  30 . It is also desirable that the distance  50  from the inside of the exit channel  36  to the outer edge of the exit cylinder  30  be greater than the diameter  42  of the exit channel  36 . It is also important to note that the entrance face  28  of the exit cylinder  30  as well as the exit face  32  of the exit cylinder  30  should be substantially perpendicular to the flow of the liquid stream. 
   EXAMPLE 2 
   In an alternative embodiment, the vent line  24  can be connected to an alternative gas source  25 . Such an alternative gas source can include pressure pumps or other means whereby a gas is delivered under pressure or otherwise for introduction into the liquid. For example, when used in a pool or other body of water in which chlorination is desired, a chlorine gas supply can be connected in fluid communication with the vent line  24 . In the alternative, the chlorine gas supply can be directly connected in fluid communication with the mixing chamber  26  at an alternate entrance. Either embodiment allows for the improved mixture of chlorine gas with water. 
   EXAMPLE 3 
   In still another embodiment, the exit channel  36  extends either distally, past the exit face  32  of the exit cylinder  30  or proximally past the entrance face  28  of the exit cylinder  30 . 
   EXAMPLE 4 
   In a still further embodiment, the internal nozzle  22  is not concentrically disposed in the mixing chamber  26 . The internal nozzle  22  may be disposed in any position in the mixing chamber  26  provided the liquid stream passing therefrom enters the exit channel  36  unobstructed. 
   EXAMPLE 5 
   In a still further embodiment, the air entering the vent line  24  is filtered by a conventional filter prior to its introduction into the mixing chamber  26 . 
   In yet another embodiment, the vent line  24  is connected to a secondary line in communication with the ambient liquid source. While this embodiment does not allow for a gas/liquid mixture, it does operate as a highly efficient vacuum for pools and the like. As such, a filter or other means to collect debris may be inserted in communication with the secondary line to allow for the collection and removal of such debris. 
   Inasmuch as the preceding disclosure presents the best mode devised by the inventor for practicing the invention and is intended to enable one skilled in the pertinent art to carry it out, it is apparent that methods incorporating modifications and variations will be obvious to those skilled in the art. As such, it should not be construed to be limited thereby but should include such aforementioned obvious variations and be limited only by the spirit and scope of the following claims.