Abstract:
A gas injector that is coupled to the pump strainer basket housing drain port of a pump-circulated system is disclosed. The gas injector that may be installed in a way that is less invasive than currently used gas injection systems to pre-existing plumbing of a pump system and that allows for more efficient gas absorption in water than currently used gas injection systems. The gas injector may be used with all currently existing pump systems.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This non-provisional application claims priority to U.S. Provisional Application No. 60/781,023 filed on Mar. 10, 2006 in the name of the Applicants of the present invention. This non-provisional application also claims priority to U.S. Provisional Application No. 60/792,272 filed on Apr. 14, 2006 in the name of the Applicants of the present invention. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to pool water pH control systems and, more specifically, to a gas injector that allows for the improved injection of gas into pump-circulated water. 
     BACKGROUND OF THE INVENTION 
     For any pump-circulated water, it is important to maintain proper pH levels to prevent the growth of bacteria and other pathogens, and to ensure that the water is not toxic or corrosive to any items, animals or persons coming into contact with the water. 
     One example of pump-circulated water is swimming pool water. Pool water pH is a measure of its total acid-alkalinity balance, i.e. the relative proportion of acids and alkalis in the water. If water is too acidic, it will cause corrosion of metal equipment and can cause skin irritation. If the water is too alkaline, it can cause scaling on the pool surface and can cloud the water. Furthermore, high acidity and high alkalinity may alter the effectiveness of the chlorine in the water. 
     Muriatic acid or sodium bisulfate are often used to lower the pool water pH. However, the use of acid proves to be inconvenient because people are prohibited from using the pool until the acid has been given a chance to mix with the pool water. Gas injectors allow for better absorption of gas (e.g. CO 2 ), which in turn helps to control the pool water pH. If these gas injectors are used to control the pool water pH, there is no longer a need for the use of acid. 
     Currently, gas is used in some large public pools to control pool water pH. However, in order to do this, the original plumbing must be cut. Once the original piping is cut, a union is placed on but sides of the cut piping and a new section defining a port is welded into place. The port usually has a ⅛ inch barb fitting that couples to tubing leading to a gas cylinder. Typically these modifications are done at the water inlet to the pump strainer basket housing, at the water outlet from the pump, and/or at the water outlet from the filter. To cut the existing piping at these points is very invasive to the original plumbing and oftentimes leads to leaks. These leaks then cause a pool owner to expend more time and money on maintenance of the pump system. 
     Therefore, a need exists for a gas injector that may be installed in a way that is less invasive than currently used systems. A further need exists for a gas injector that allows for more efficient gas absorption in water. Preferably, the gas injector is coupled to the pump strainer basket housing drain port. Further preferably, the gas injector may be used with all currently existing pump systems. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a gas injector that may be installed in a way that is less invasive than currently used gas injection systems to the pre-existing plumbing of a pump system. 
     It is another object of the present invention to provide a gas injector that allows for more efficient gas absorption in water than currently used gas injection systems. 
     It is still another object of the present invention to provide a gas injector that is coupled to the pump strainer basket housing drain port. 
     It is still another object of the present invention to provide a gas injector that may be used universally with all currently existing pump systems. 
     BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In accordance with one embodiment of the present invention, a gas injector system is disclosed. The gas injector comprises a hollow body, a connector coupled to a proximal end of the hollow body, a valve chamber coupled to a distal end of the connector and housed within the hollow body, a backflow prevention valve housed within the valve chamber, and a sintered diffusion insert coupled to a distal end of the backflow prevention valve. 
     In accordance with another embodiment of the present invention, a gas injector is disclosed. The gas injector comprises a hollow body having a threaded distal end and a flange coupled proximate the threaded distal end, the distal end being approximately 0.35 inches long, ¼ NPT, and having a width that tapers from approximately 0.525 inch to approximately 0.5 inch; a connector coupled to a proximal end of the hollow body, the connector having a threaded distal end for engaging a threaded aperture defined by a proximal end of the hollow body; a valve chamber coupled to a distal end of the connector and housed within the hollow body; an umbrella valve housed within the valve chamber; and a sintered diffusion insert coupled to a distal end of the umbrella valve, wherein the sintered diffusion insert has a diameter of approximately 0.25 inch and wherein a distal end of the sintered diffusion insert protrudes out of the threaded distal end of the hollow body by approximately 0.35 inch. 
     In accordance with another embodiment of the present invention, a method for injecting gas into pump circulated-water is disclosed. The method comprises the steps of: providing a gas injector comprising: a hollow body; a connector coupled to a proximal end of the hollow body; a valve chamber coupled to a distal end of the connector and housed within the hollow body; a backflow prevention valve housed within the valve chamber; and a sintered diffusion insert coupled to a distal end of the backflow prevention valve; coupling a proximal end of the connector to a gas delivery mechanism and coupling a distal end of the hollow body of the gas injector to a pump strainer basket housing drain port; releasing gas from the gas delivery mechanism and through the gas injector; diffusing the gas by passing it through the sintered diffusion insert; blending the diffused gas with water that enters into the pump strainer basket housing; passing the diffused gas and water through a pump impellar and into a filter; and passing the diffused gas and water out of the filter. 
     The foregoing and other objects, features, and advantages of the invention will be apparent from the following, more particular, description of the preferred embodiments of the invention, as illustrated in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram of a gas injection system of the present invention shown coupled to a standard delivery mechanism. 
         FIG. 2  is a perspective view of a gas injector of the system of  FIG. 1 . 
         FIG. 3  is an exploded perspective view of the gas injector of  FIG. 2 . 
         FIG. 4  is a side cross-sectional view of the gas injector of  FIG. 2 . 
         FIG. 5  is a cross-sectional view of  FIG. 4 , taken along lines  5 - 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The novel features believed characteristic of the invention are set forth in the appended claims. The invention will best be understood by reference to the following detailed description of illustrated embodiments when read in conjunction with the accompanying drawings, wherein like reference numerals and symbols represent like elements. 
       FIGS. 1-5  show a system  10  using the gas injector  12  of the present invention. The gas injector  12  comprises a hollow body  20 , a connector  14 , a backflow prevention valve  17  within a valve chamber  16 , and a sintered diffusion insert  18 . 
     Referring to  FIG. 1 , the system  10  is shown used with a prior art gas delivery mechanism  11 . The prior art gas delivery mechanism  11  typically comprises a gas cylinder  28 , a pressure regulator  30 , a timer  32 , a solenoid valve  34 , and delivery tubing. The system  10  of the present invention comprises the gas injector  12 , a pump strainer basket housing  40 , a pump impeller  42 , a pump motor  44 , and a filter  48 . Piping or tubing is used for the gas inlet  36  to the pump strainer basket housing  40 , the water inlet  38  to the pump strainer basket housing  40 , the water outlet  46  from the pump impellar  42 , and the water outlet  50  from the filter  48 . 
     Referring now to  FIGS. 2-5 , the gas injector  12  has a hollow body  20  that may be made of acrylic, plastic, metal, or any other suitable rigid material. Although the hollow body  20  is shown as being substantially cylindrical, it should be clearly understood that substantial benefit may be derived from the hollow body  20  being square, rectangular, or triangular. It is preferable that the hollow body  20  has an outer surface  52  that has at least two flat sides  54  that will allow a person to use his/her hand or a wrench to rotate the hollow body  20  when attaching it to pump strainer basket housing  40 . It should also be understood that substantial benefit may nevertheless be derived from a completely smooth outer surface  52 . 
     The hollow body  20  preferably has a proximal end  56  that defines a threaded aperture  58  and has a threaded distal end  24 . The threaded distal end  24  helps to facilitate male-to-female engagement of the gas injector  12  to the pump strainer basket housing  40 . It is also preferable, though not required, that the hollow body  20  also have a flange  22  proximate the threaded distal end  24 . In order to fit most commercially available pumps, it is preferred that the threaded distal end  24  be approximately 0.35 inches long, ¼ NPT (National Pipe Thread), and have a width that tapers from approximately 0.525 inch to approximately 0.5 inch. It is also preferred that the flange  22  have a diameter of approximately 0.688 inch and a width of approximately 0.1 inch. It should be clearly understood that while these dimensions are preferred for universal installation capability, substantial benefit may be derived from the threaded distal end  24  and flange  22  having different dimensions and/or from there being no flange  22  at all. 
     An O-ring  26  may also be used to help seal the connection of the threaded distal end  24  to the pump strainer basket housing  40 . The O-ring  26  is preferably dimensioned to be coupled about the threaded distal end  24  proximate the flange  22  to help prevent air leaks at the suction side of the pump. 
     The connector  14  preferably has a threaded distal end  66  dimensioned to engage the threaded aperture  58  defined by the proximal end  56  of the hollow body  20 . While it is preferred that the threaded distal end  66  of the connector  14  and the threaded aperture  58  of the proximal end  56  of the hollow body  20  be ¼ NTP, it should be clearly understood that substantial benefit may be derived from a different size thread. The connector  14  also preferably has a quick-connect proximal end  64 . The quick-connect proximal end  64  is preferably a smooth slip-connect fitting for high-pressure hose. It should also be clearly understood that the quick-connect proximal end  64  could also be a barbed flange-type connection. While it is preferred that the quick-connect proximal end  64  be dimensioned to connect to 5/32 inch tubing, it should be clearly understood that any other size tubing may be used as long as the tubing is the same size as (or only slightly larger than) the aperture inside the pressure regulator  30 . 
     A valve chamber  16  is coupled to a distal end  66  of the connector  14  and is housed within the hollow body  20 . And a backflow prevention valve  17  is housed within the valve chamber  16 . When gas flow stops, the backflow prevention valve  17  keeps water from returning to the pressure regulator  30  and the gas cylinder  28  and causing damage. The backflow prevention valve  17  is preferably an umbrella valve, but it should be clearly understood that substantial benefit may still be derived from the use of a duck-bill type valve, a ball-type valve, a piston-type check valve, or any other suitable valve or backflow prevention device. It is also preferred that the backflow prevention valve  17  be made of rubber, plastic or some other suitable material that is both pliable and waterproof. 
     The sintered diffusion insert  18  has a quick-connect proximal end  60  that is coupled to a distal end  62  of the backflow prevention valve  17 . In order to universally fill all available pumps, it is preferred that the sintered diffusion insert  18  has a diameter of approximately 0.25 inch and that a distal end  70  of the sintered diffusion insert  18  protrudes out of the threaded distal end  24  of the hollow body  20  by approximately 0.35 inch. However, it should be clearly understood that substantial benefit may be derived from the sintered diffusion insert  18  having different dimensions. And while the sintered diffusion insert  18  is shown as being substantially cylindrical, it should be clearly understood that substantial benefit may be derived from the sintered diffusion insert  18  being square, hexagonal, or rectangular or any other shape. Preferably, the sintered diffusion insert  18  is made of ceramic, sand, bonded glass bead, or any other suitable porous material. 
     Statement of Operation 
     When using a typical gas delivery mechanism  11 , the solenoid valve  34  is attached to an open outlet port in the gas pressure regulator  30 . The gas pressure regulator  30  is then attached to a gas cylinder  28 . While it is preferred that the gas cylinder be filled with CO 2 , it should be clearly understood that substantial benefit may be derived from the use of chlorine gas or any other gas that helps to control pH levels. Further preferably, the minimum cylinder capacity is 20 lbs; however, any size cylinder  28  may be used. Gas deliver pressure at the pressure regulator  30  is preferably set at approximately 30 psi, but it may be anywhere in between 20 psi and 40 psi. Gas flow may also be regulated by a volume regulator (not shown) or needle valve (not shown). The power supply wiring from the solenoid valve  34  to the timer  32 . The solenoid valve  34  may be either AC or DC as determined by the timer. Also, it is preferable that the solenoid valve  34  be configured as normally “closed,” however, it may be configured normally at “open.” Gas delivery tubing is then used to connect the solenoid valve  34  to the gas injector  12 . 
     The circulation pump drain plug is removed and the gas injector  12  is preferably installed in the pump strainer housing drain port located at the bottom of the pump strainer basket housing  40 . This is the preferred injection site because it facilitates rapid gas saturation while mixing with the water passing through the pump strainer basket housing  40 . Also, this injection site is non-intrusive and offers ease of installation as compared to rerouting or disturbing existing plumbing. Gas injection at this site is efficient and cost-effective. 
     As CO 2  passes through the sintered diffusion insert  18 , it is reduced to very tiny bubbles. Since these tiny bubbles are injected in the bottom of the pump strainer basket housing  40 , they want to rise upon entering the water. The water inlet  38  to the pump strainer basket housing  40  is located in the top of the pump strainer basket housing  40  and the water naturally wants to drop upon entering the pump strainer basket housing  40 . The pump impeller  42  inlet is located in the middle of the pump strainer basket housing  40 . The net result is the collision of the tiny bubbles and the water in the pump strainer basket housing  40  before they are rapidly pulled into the pump impeller  42 . This process improves CO 2  absorption. 
     As the water and the tiny bubbles of CO 2  are pulled through the pump impeller  42  they are blended together. This blending process also improves the CO 2  absorption. 
     The Diffusion Bell concept is a diffusion/absorption concept used by aquarists in the maintenance of aquariums. It states that air trapped in the top of a bell placed at the bottom of an aquarium will eventually be absorbed by the water. A swimming pool filter works in the same manner. While the pump is running, there is constant pressure on the inside of the filter  48 . In the present invention, any CO 2  that is unabsorbed in the diffusion or blending steps will be caught at the top of the filter  48  and will eventually be absorbed by the water. 
     A timer  32  may be used to open the solenoid valve  34  during the normal operating schedule of the water circulation pump so as to deliver sufficient gas volume to reduce pH to the desired range. The preferred solenoid valve  34  operation controller is a programmable timer. However, solenoid valve  34  operation may be controlled by a manual on/off switch or a computer controlled pH sensor. 
     While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.