Abstract:
A method and apparatus for turbulently exposing water flowing through a water system to a plurality of electrodes of an ion generator and having a self-contained tank through which water flows is provided with an inlet pipe that directs water flow between the electrodes. A tank cover serves as a non-electrical conducting head for the plurality of electrodes that extend downwardly from the underside of the cover. The electrodes are functionally configured to maximize water flow between them. Following the flow of water between the electrodes, a double vortex of water flow is created along one wall of the tank. A sight glass allows for visualization of the container contents, and in particular electrode wastage or wear, during operation.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to methods and devices used with water systems. More particularly, it relates to an improved method and apparatus for exposing water, flowing through a water system, to an ion generator whereby ions are fed into the water flow to prevent fouling of the water system by algae, nuisance invertebrates, microorganisms, and inorganic salts. This invention also specifically relates to an improvement of the inventors&#39; method and apparatus disclosed and claimed in U.S. Pat. No. 6,350,385. 
     BACKGROUND OF THE INVENTION 
     It has long been known that algae, nuisance invertebrates, microorganisms, and inorganic salts may foul water systems and lead to very significant water system inefficiencies. These inefficiencies result in increased energy consumption and increased maintenance demands that, in turn, increase overall operational and maintenance costs by several orders of magnitude. Ion generators have been employed in previous attempts to control algae, nuisance invertebrates, and microorganisms. Such ion generators are based on well-known principles of electrochemical reactions, one of which is referred to as electrolysis. 
     Electrolysis is an electrochemical process by which electrical energy is used to promote chemical reactions that occur on the surface of functionally cooperating electrodes. One electrode, called the anode, involves the oxidation process where chemical species lose electrons. A second electrode, called the cathode, involves the reduction process where electrons are gained. In water, for example, oxygen is generated at the anode and hydrogen is generated at the cathode. The generation of hydrogen and oxygen in fresh water by the process of electrolysis will be weak due to the low electrical conductivity of the water. The oxygen generated aids in the prevention of the deposit of inorganic salts on the electrodes. The function of an ion generator is also to produce metal ions, typically copper ions or silver ions. Metal ion production is accomplished by use of an electrically charged metal anode that comprises atoms of the metal ions that are to be generated. It is the purpose of the ion generator to feed the metal ions out of the generator before they can be deposited on a cathode. The metal ions and oxygen, both of which are produced by the ion generator, are feed into the water stream of the water system to prevent fouling of the system by algae, nuisance invertebrates, microorganisms, and inorganic salts. As previously mentioned, one such system was devised by these inventors and is the subject of U.S. Pat. No. 6,350,385 issued to Holt, et al. 
     The toxicity of copper and silver to aquatic organisms is well established although the exact mechanism is not well defined. In general, these heavy metals must be in an ionic form in order for them to be toxic to invertebrates, microorganisms and algae. The eradication of microorganisms is attributed to positively charged ions that are both surface active and microbiocidal. These ions attach themselves to the negatively charged bacterial cell wall of the microorganism and destroy cell wall permeability. This action, coupled with protein denaturation, induces cell lysis and eventual death. One advantage to the use of metal ionization is that eradication efficacy is wholly unaffected by water temperature. Chlorine, a commonly used antifouling chemical, is somewhat temperature dependent. Furthermore, the metal ions actually kill the microorganisms, and other microorganism promoting bacteria and protozoa, rather than merely suppress them, as in the case of chlorine. This minimizes the possibility of later recolonization. Other advantages of metal ionization compared to other eradication techniques include relatively low cost, straightforward installation, easy maintenance, and the presence of residual disinfectant throughout the system. 
     A copper or silver ion generator is, by way of specific example, an effective method for controlling legionella which is likely to be present in most water systems. Legionella is predominantly present in water cooling systems in microbial biofilms which become attached to surfaces submerged in the aquatic environment. These biofilms are typically found on the surfaces of pipes and stagnant areas of the water cooling system. Many components of most any man-made water system can be considered to be an amplifier for the organism (i.e., the organism can find a niche where it can grow to higher levels, or be amplified) or a disseminator of the organism. Examples of man-made amplifiers include cooling towers and evaporative condensers, humidifiers, potable water heaters and holding tanks, and conduits containing stagnant water. Showerheads, faucet aerators, and whirlpool baths may serve as amplifiers as well as disseminators. Human infection from exposure to legionella, or legionosis, can result in a pneumonia illness that is commonly referred to as Legionnaire&#39;s disease, namesake of the famous 1976 outbreak in Philadelphia. Since that outbreak, about 1,400 cases are officially reported to the Center for Disease Control annually. 
     Other bacteria and protozoa can also colonize water cooling system surfaces and some have been shown to promote legionella replication. Amoebae and other ciliated protozoa are natural hosts for legionella. Legionella multiply intracellularly within amoebae trophozoites.  Legionella pneumophila  is known to infect five different genera of amoebae, most notably  Hartmanella vermiformis  and Acanthamoeba. Legionella can also multiply within the ciliated protozoa, Tetrahymena. Bacterial species that appear to provide legionella with growth-promoting factors include Pseudomonas, Acinetobactor, Flavobacterium, and Alcaligenes. Copper and silver ions are an effective method of control for each of these bacteria and protozoa. The controlled release of copper or silver ions has also been known to serve as an effective attachment and growth control for such marine organisms as algae, mussels, oysters and barnacles. Such ions can eliminate and control algae, for example, by inhibiting photosynthesis which leads to its demise. 
     In the experience of these inventors, users of present metal ion generators in industrial cooling water systems have reported problems such as bridging which leads to electrical shorting, electrical conductivity stratification which results in uneven electrode erosion, and plating of metal on the cathode. Bridging occurs because of the necessity of placing the anode and cathode in close proximity to one another in fresh water systems. One way of dealing with this problem is to periodically reverse polarity of the electrodes. Uneven electrode erosion due to electrical conductivity stratification occurs for the reason that nonuniform water flow occurs between electrodes. In present designs, the velocity of the water that flows between the electrodes is not generally constant over the electrode face. This leads to stratification of inorganic materials in the water that, in turn, produces electrical conductivity stratification. Finally, plating of the metal anode material on the cathode, as previously mentioned, completely defeats the purpose of the ion generator in the present application. When plating occurs, the metal ions are deposited on the cathode rather than being introduced into flow stream that is to be treated. In the experience of these inventors, each of these problems is related to water flow and to electrode spacing, which is required to be very close in fresh water systems. The spacing of the electrodes in close proximity to each other in fresh water systems is required if power system expectations are to be within reason, on the order of a few hundred watts. The system simply will not be economical if maximum power requirements exceed several kilowatts. 
     SUMMARY OF THE INVENTION 
     It is, therefore, a principal object of this invention to provide an improved method and apparatus for exposing the water flow within a water system to an ion generation device wherein water velocity is increased between the electrodes of the ion generator. It is another object of this invention to provide such an improved method and apparatus where a water inlet is provided to create a high velocity flow within the system, which flow is directed between the ion generating electrodes. It is yet another object to provide such an improved method and apparatus where a double vortex flow is created following water flow from between the electrodes. It is yet another object to provide such an improved method and apparatus which avoids “dead zones,” or areas where water velocities in the vicinity of the ion generator electrodes are low. It is still another object to provide such a method and apparatus in which a non-electrical conducting head is used to mount the electrodes of the ion generator and where a plurality of cooperatively alternating anodes and cathodes may be used. It is another object of the present invention to provide such an improved method and apparatus in which polarity of the electrodes is periodically reversed. It is yet another object of the present invention to provide such an improved method and apparatus in which a discharge valve is provided to control the system water level within the ion generator thereby maintaining a minimum vertical velocity within the system. It is still another object to provide a self-cleaning elliptical or conical base to the flow tank. It is yet another object to provide such an improved method and apparatus wherein a sight glass is utilized to allow for visual inspection of anode wastage. It is still another object to provide such an improved method and apparatus wherein performance is optimized while manufacturing costs are not increased significantly. 
     The present invention has obtained these objects. It overcomes problems and disadvantages of prior systems by providing an improved method and apparatus in which water flowing through a water system is vigorously and turbulently exposed to a plurality of electrodes of an ion generator whereby ions that are generated are fed into the water flow to prevent fouling of the water system by algae, nuisance invertebrates, microorganisms, and inorganic salts. The present invention accomplishes this by providing an ion generator having a self-contained tank through which the water flows. The generally cylindrical containment tank includes an inlet pipe at the uppermost portion of the tank. An elliptical tank base includes an outlet pipe in combination with a tank clean out device at the lowermost portion of the tank. A tank cover is provided which serves as the non-electrical conducting head for a plurality of electrodes that extend downwardly and generally parallel to one another from the underside of the cover. When the tank cover is in place in its normal operating position, the electrodes are suspended from the tank cover within the containment tank. The inlet pipe is functionally configured to introduce water directly between the electrodes. The electrodes are functionally configured, both in size and placement, to maximize water flow between them, thereby creating a double vortex flow following water flow between the electrodes. Circuitry is provided to allow for periodic reversal of polarity of the electrodes. A sight glass is provided within the containment tank to allow for visualization and monitoring of the container contents, and in particular anode wastage or wear, during operation. The foregoing and other features of the improved method and apparatus of the present invention will be apparent from the detailed description that follows. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front elevational view of the improved water system fouling control apparatus constructed in accordance with the present invention. 
     FIG. 2 is a top plan view of the improved water system fouling control apparatus shown in FIG.  1 . 
     FIG. 3 is a partially sectioned front elevational view of the improved water system fouling control apparatus shown in FIG.  1  and taken along line  3 — 3  of FIG.  2 . 
     FIG. 4 is a front, top and right side perspective view of the improved water system fouling control apparatus shown in FIG.  3 . 
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings in detail, wherein like numerals represent like elements throughout, FIG. 1 illustrates a preferred embodiment of a device that utilizes the improved method and apparatus of the present invention. 
     An ion generator apparatus, generally identified  10 , includes a containment tank  12  that is generally cylindrical in physical configuration. The containment tank  12  includes an upper tank portion  14  and a lower tank portion  16  and is constructed of stainless steel in the preferred embodiment, although the material is not a limitation of this invention. The tank  12  also includes an upper tank portion aperture  15  and, situated about the perimeter of the upper tank portion aperture  15 , an upper tank flange  18 . The containment tank  12  is supported about its outer perimeter by a plurality of support legs  44 , each support leg  44  being attached to the tank  12 . Each leg  44  also includes a support foot  46  that rests upon a generally horizontal surface  88 . As shown in FIGS. 2 and 4, three such legs  44  are illustrated. It is to be understood that more legs  44  could be utilized if such was desired or required, the number of such legs  44  not being a functional limitation of the present invention. 
     Attachable to the upper tank flange  18  is a tank cover or lid  20 . The lid  20  includes a lid perimeter  22 , a top lid surface  24  and a lid underside surface  26 . In the preferred embodiment, the lid  20  is constructed of a special polymar plastic material which provides strength, durability and electrical nonconductivity. The significance of this electrical nonconductive, or electrical insulating, feature will become apparent later in this detailed description. The lid  20  is attachable to the upper tank portion  14  by means of a plurality of fasteners  86 , such as bolts, which are installed about the lid perimeter  22  and through the upper tank flange  18 . See FIGS. 2 and 3. Here again, the number of such fasteners  86  is not a functional limitation of the present invention. The number of fasteners  86  may be varied without deviating from the scope of this invention. The important feature of the fasteners  86  is that they prevent the lid  20  from coming away from the tank  12  and that they prevent rotation of the lid  20  about the tank  12 . 
     Sealingly attached to the lower tank portion  16  is an elliptical head  34 . The lowermost portion of the head  34  includes a centrally located bottom aperture  38 . Attached to the aperture  38  is a bottom flange  40 . Attached to the bottom flange  40  is an elbow  48  which includes a first flanged end  92 , a discharge sampling valve  94 , and a second end  96 . Attached to the second end  96  is a ball valve  97 , an inline flow meter  98  and a discharge pipe  99  through which tank discharge flow  8  is accomplished. The flow meter  98  may be wired to control inlet flow. 
     Attached to the underside  26  of the lid  20  are a number of functionally cooperating electrodes  50 ,  60 . As shown in the preferred embodiment, one anode  50  and one cathode  60  is provided. It is to be understood that the number of such electrodes  50 ,  60  is not a functional limitation of the present invention. Other combinations could be provided, such as two anodes and two cathodes, and so on, without deviating from the scope of the present invention. As shown, the anode  50  and the cathode  60  are each fabricated in the shape of a rectangular prism. In the preferred embodiment, the anode  50  is made of silver as is the cathode  60 . Again, the material from which each of the electrodes  50 ,  60  is made is not a limitation of the present invention, other than that the materials used must be functionally conducive to the process of electrolysis. The use of like material for the electrodes  50 ,  60  allows an electronic polarity reverser (not shown) to be used which reduces the rate of oxide buildup on the silver anode  50  which, in turn, reduces the time between scheduled anode cleanings. 
     The anode  50  includes a top anode portion  52 , a central anode portion  54 , a bottom anode portion  58 , and a pair of anode faces  56 , the anode faces  56  being generally parallel to one another and providing the greatest surface area of the anode  50 . Similarly, the cathode  60  includes a top cathode portion  62 , a central cathode portion  64 , a bottom cathode portion  68 , and a pair of cathode faces  66 . The anode  50  is attached to the lid underside  26  by means of a plurality of anode fasteners  102 . See FIG.  2 . Similarly, the cathode  60  is attached to the lid underside  26  by means of a plurality of cathode fasteners  104 . At the bottom portion  58  of the anode  50  and the bottom portion  68  of the cathode  60  is a stabilizing element  90 . The stabilizing element  90  is functionally adapted to maintain the electrodes  50 ,  60  in substantially parallel planar relationship. In this parallel planar relation, the plane defined by each electrode  50 ,  60  is substantially parallel to the axis of the inlet pipe  30 . See FIGS. 2 and 3. As shown, one of the anode fasteners  102  is attached to a positive electrical lead  112  through which an electrical current may flow. Similarly, one of the cathode fasteners  104  is attached to the cathode  60  and is also attached to a negative, or grounding, lead  114 . An electrical potential or voltage may be applied across the anode lead  112  and the cathode lead  114  and, therefore, across the anode  50  and across the cathode  60 . In the preferred embodiment, a power supply on the order of several hundred watts may be applied to achieve the electrochemical process of electrolysis across the electrodes  50 ,  60 . 
     The upper tank portion  14  also includes an inlet pipe  30  that provides a continuum with the interior  80  of the containment tank  12 . As shown, the flow path  2  through the inlet pipe  30  is generally perpendicular to the axis of the tank interior  80 . The tank  12 , the elliptical head  34  and the inlet pipe  30  are functionally cooperative to allow water flow  2  through the inlet  30 , into the tank interior  80  in a whirlpool-like or double vortex flow  4 , and out the bottom aperture  38  of the head  34  in a discharge flow  6 . See FIGS. 2 and 3. The significance of this flow pattern will become apparent later in this detailed description. The containment tank  12  also includes a sight glass aperture (not shown) defined within the wall  13  of the tank  12 . Attached to the aperture is a sight glass flange  82  and a sight glass  84 . The purpose of the sight glass  84  is to provide visual access to the tank interior  80 . 
     In application, water flow  2  is initiated to the interior  80  of the tank  12  by means of an inlet pipe  30 . In this fashion, water enters the tank interior  80  and is directed to forcibly flow between the electrodes  50 ,  60 . Upon exiting the area between the electrodes  50 ,  60 , the water follows the annular wall surface  13  in a whirlpool-like or turbulent double vortex-type fashion. That is, the water flow is effectively “split” at that portion of the wall surface  13  immediately opposite the inlet and continues in two opposite directions back around the electrodes  50 ,  60  and along the wall surface  13 . This double vortex turbulence facilitates the electrolysis process and the migration of silver ions away from the anode  50  and away from the cathode  60  before the ions have a chance to attach themselves to the cathode  60  thus defeating the purpose of ionic water treatment. The flow  4  continues about the electrodes  50 ,  60  until the water flow  6  discharges through the head aperture  38 , the water being properly ionized at this point. The elliptical head  34  and the aperture  38  defined in it serves a “self-cleaning” function by discharging suspended solids contained within the flow stream  6 . The water ionization at this point of discharge serves to control algae, nuisance invertebrates, microorganisms and inorganic salts lurking in other parts of the water system within which the ion generator assembly  10  of the present invention is incorporated. As the eletrolysis process continues, the electronic polarity reverser (not shown) cycles at reversing rates from 0.1 second to 1,000 minutes depending on rates of reversal deemed appropriate for a specific site operation. Gradually, the anode  50  effectively becomes used up as ions are given up to the water flow  4 . The sight glass  84  allows the user to view the containment tank interior  80  to determine if anode wastage has occurred to the point that the anode  50  must be replaced. Replacement of the anode  50  is easily accomplished by removal of the tank lid  20 , detachment of the anode lead  112 , withdrawal of the anode fasteners  102 , insertion of a new anode  50 , replacement of the anode fasteners  102 , reattachment of the anode lead  112  and reseating of the lid  20 . 
     From the foregoing description of the illustrative embodiment of the invention set forth herein, it will be apparent that there has been provided an improved method and apparatus for exposing the water flow within a water system to an ion generation device wherein water velocity is increased between the electrodes of the ion generator; where a perpendicular inlet is provided to create a high velocity vortex flow within the system in the vicinity of the ion generator electrodes and which avoids “dead zones,” or areas where water velocities in the vicinity of the ion generator electrodes are low; where a non-electrical conducting head is used to mount the electrodes of the ion generator and where a plurality of cooperatively alternating anodes and cathodes may be used; where a discharge valve is provided to control the system water level within the ion generator thereby maintaining a minimum vertical velocity within the system; where a self-cleaning elliptical or conical base to the flow tank is provided; and where a sight glass is utilized to allow for visual inspection of anode wastage.