Abstract:
Loosely packed electrically conductive material is retained within a tube of dielectric material. A sheath of electrically conductive material surrounds the tube. A pair of electrodes, adapted to be connected to a source of high voltage are electrically connected to the material and the sheath, respectively, to generate corona discharge between the material and the tube and between elements of the material to transform oxygen molecules in a gas passing through the material in the tube into ozone to produce an ozone enriched outflow of gas.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     The present application is a divisional application of an application entitled “Corona Discharge Ozone Generator”, filed on Jun. 9, 2003 and assigned Ser. No. 10/457,284, which application claims priority to a provisional application entitled “Ozone Generator”, filed on Jun. 11, 2002 and assigned Ser. No. 60/387,797 and describing an invention made by the present inventor. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     Ozone generators have been used for decades to convert molecules of oxygen present in the air to molecules of ozone to produce ozone enriched air. The ozone enriched air serves as a powerful oxidizer and is often used as a disinfectant. A particular widespread use of the ozone enriched air is that of entraining the air in water to destroy any bacteria (or other organic matter) present as a result of the oxidizing effect of the ozone. Such water purification may be for purposes of purifying drinking water or water used as a rinse in a dental office. Other uses include purification of the water in aquariums. These uses are of relatively low volumetric water flow rates. On a larger scale and which require more massive ozone generators other uses include purification of the water in swimming pools, spas and the like.  
         [0003]     Ozone generators are generally of two types. The first type utilizes ultra violet (UV) radiation to irradiate a flow of air. Some of the radiated oxygen molecules are transformed into ozone molecules to produce an ozone enriched flow of air. A second type uses corona discharge between two electrodes to convert oxygen molecules in air flowing therebetween into ozone molecules. This also produces an ozone enriched air flow.  
       SUMMARY OF THE INVENTION  
       [0004]     A corona discharge ozone generator includes a tube of a dielectric composition and contains loosely packed electrically conductive material to provide a passageway through which air to be ozonated is passed. A tape or sheet of electrically conductive composition is wrapped about the tube in general proximity with the material within the tube. An apertured plug is disposed at each end of the tube to loosely retain the electrically conductive material therebetween; the plugs may also support opposed ends of the tape or sheet or a component thereof. A first electrode is in contact with the material and a second electrode is in contact with the tape or sheet. The first and second electrodes are connected to a source of electrical power to provide a voltage across the electrodes of sufficient value to cause corona discharge to occur. By impressing a significant voltage across the electrically conductive material and the tape or sheet via the first and second electrodes associated with therewith, corona discharges will occur within the tube and across air spaces between particles of the material. The corona discharge occurring within the tube will transform oxygen molecules present in an air flow through the tube into ozone molecules and result in an ozone enriched outflow of air.  
         [0005]     It is therefore a primary object of the present invention to provide a corona discharge ozone generator.  
         [0006]     Another object of the present invention is to provide a scalable corona discharge ozone generator.  
         [0007]     Yet another object of the present invention is to provide an inexpensive corona discharge ozone generator.  
         [0008]     Still another object of the present invention is to provide a corona discharge ozone generator that may be flooded without short circuiting the electrical power supply.  
         [0009]     A further object of the present invention is to provide a corona discharge ozone generator which will not burn up upon intrusion of water into a tube for accommodating an air flow subjected to the corona discharge.  
         [0010]     A yet further object of the present invention is to provide a method for generating ozone by corona discharge.  
         [0011]     A still further object of the present invention is to provide a disposable corona discharge ozone generator.  
         [0012]     These and other objects in the present invention will become apparent to those skilled in the art as the description thereof proceeds.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     The present invention will be described with greater specificity and clarity with reference to the following drawings, in which:  
         [0014]      FIG. 1  illustrates a conventional prior art corona discharge ozone generator;  
         [0015]      FIG. 2  is a cross sectional view of a corona discharge ozone generator incorporating the present invention;  
         [0016]      FIG. 2A  representatively illustrates a power source for the corona discharge ozone generator; and  
         [0017]      FIG. 3  is a cross sectional view taken along lines  3 - 3 , as shown in  FIG. 2 .  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0018]     Referring to  FIG. 1 , there is shown a prior art ozone generator using corona discharge. An electrically conductive shell or tube  12  concentrically encloses an inner electrode assembly  14 . The assembly includes a glass tube  16  (like a test tube) having a closed end  18  and an open end  20 . The tube is filled with tightly packed electrically conductive elements  22 , which elements may be electrically conductive carbon powder, metal filings, etc. An electrode  24  is in electrical communication with elements  22 ; typically, the electrode may include an insulating sheath  26  external of elements  22 . An electrode  28  is in electrical communication with tube  12  and includes a sheath  30  of electrically insulting material. It is preferable that inner electrode assembly  14  be maintained concentrically within tube  12 . For this purpose, a plurality of spacers  32  may be employed. As the air flow through the ozone generator flows through annular space  34  intermediate tubes  12  and  16 , spacers  32  must be configured to have a minimal restriction upon such air flow. In operation, air flow enters one end of ozone generator  10 , as represented by arrow  36  and exits from the ozone generator, as represented by arrow  38 .  
         [0019]     As is well known, a high voltage is impressed upon electrodes  24  and  28  by a suitable power source (not shown). The resulting high potential between elements  22  and tube  12  will result in periodic corona discharges across annular space  34 . As air flows through the annular space, and is subjected to repeated corona discharges, some of the oxygen molecules in the air will be transformed into ozone molecules. Thereby, the air outflowing from ozone generator  10  will be ozone enriched.  
         [0020]     Certain problems exist with prior art ozone generators of the type shown in  FIG. 1 . These problems include a difficulty of maintaining a constant size annular space between the two electrodes. Without a constant air space, there will be localized arcing with resulting pitting and deterioration of tube  12 . The channeling of an air flow into and out of ozone generator  10  presents problems of insuring an even air flow through the annular space and tight manufacturing tolerances are necessary, which increases the costs of manufacture. The products resulting from corrosion will accumulate and must be periodically mechanically removed. Such removal requires disassembly and the attendant maintenance costs are significant. To minimize corrosion exacerbated by high humidity air passing through the ozone generator, an air drying apparatus may need to be used external of the ozone generator which further increases the costs and practical aspects.  
         [0021]     Referring jointly to  FIGS. 2, 2A  and  3 , an ozone generator  40  embodying the present invention will be described. Electrically conductive material  42 , such as metal machine chips, metal wool particles, shredded metal foil, metal foil balls, etc., are loosely packed within a tube  44  of dielectric material. A plug  46  of dielectric material extends into one end of tube  44  and includes a passageway  48  extending therethrough. A second plug  50  is secured in the other end of tube  44  and it also includes a passageway  52  extending therethrough. Material  42  is loosely packed between the two plugs to a degree of looseness sufficient to accommodate an air flow therethrough. It is to be understood that an apertured flange, wall, dam, cap or the like may be used in place of either or both of plugs  46 ,  50 . An electrode  54  extends through and is secured by plug  46  into electrical contact with material  42 . A sheath  56  encircles electrode  54  externally of plug  46 . An electrically conductive sheath  60  extends about tube  44  generally coincident with material  42  within the tube. The sheath may be an electrically conductive foil wrap, such as aluminum foil, or a wrapped length of electrically conducting tape. Alternatively, an electrically conductive coating may be applied about tube  44 . An electrode  62  is in electrical contact with sheath  60 ; the electrode may include an electrically insulating sheath  64  extending externally from plug  46 . A covering  66  of electrically insulating material extends about sheath  60 . This covering may be shrink type tubing, PVC type adhesive tape, etc. Electrodes  54 ,  62  are connected to conventional electrical conductors (also identified by reference numerals  54 ,  63 ), which in turn are connected to a source  67  of electrical power.  
         [0022]     In operation, a high voltage is impressed upon electrodes  54  and  62 . The resulting high potential will cause arcing in the air spaces adjacent material  42  in a generally random manner. A source of air flow enters ozone generator  40  through passageway  48  of plug  46 , as depicted by arrow  68 . The air flow in and about material  42  will be subjected to the electrical discharges occurring about the material within tube  44  and oxygen molecules will be transformed into ozone molecules. Ozone enriched air will exhaust through passageway  52  in plug  50 , as depicted by arrow  70 .  
         [0023]     It is to be understood that tube  40  is preferably cylindrical to minimize costs and permit simple manufacture of plugs  46 ,  50 . However, the tube may be oval, square, rectangular, etc. in cross section depending upon specific requirements attendant its use or for other reasons. Furthermore, it is preferable that material  42  be of non-corrosive material, such as stainless steel or aluminum to provide longevity despite being subjected to the corrosive effects of water or other liquids or gases.  
         [0024]     As is evident from the above description and illustrations in the drawings, ozone generator  40  differs from prior art ozone generators in that it employs a flow of air through a packing media serving the purpose of an electrode. This eliminates problems of uneven air (gas) flows and requirements for high tolerance components. Moreover, the corona discharge occurs by arcing between elements of material  42  and tube  44 , which tube is of dielectric material, such as a glass tube or a ceramic tube. As noted above, arcing may also occur through the air spaces between elements of material  42 .  
         [0025]     Ozone generator  40  is a very simple apparatus and relatively inexpensive to manufacture. The attendant low cost renders it particularly useful as a consumer product for use with spas, pools, aquariums and devices having a relatively small volume of water to be treated. In fact, ozone generator  40  is so inexpensive that replacement, instead of repair, would be more fiscally prudent.  
         [0026]     Because of the convoluted air flow through loosely packed material  42 , significant mixing of the ozone created with the air occurs such that the ozone enriched air discharged from the ozone generator is relatively homogenous.  
         [0027]     In any ozone generator, deposits of foreign materials conveyed by the inflowing air and corrosion will occur. Because of the arcing that occurs between elements of the loosely packed material, such deposits and corrosion may be burned away. Furthermore, by simply shaking or vibrating the ozone generator, the elements of material  42  will become rearranged and different surface areas will be exposed to arcing.  
         [0028]     It is to be noted that the inlet end of tube  44  may be packed with a desiccant to remove moisture from the inflowing air. This will reduce contamination of material  42  due to moisture and possible formation of nitric acid. Furthermore, inlet and outlet screens may be disposed intermediate the passageway of the respective plug and material  42  or at the other end of the plug (or at the inlet of tube  44 ) to prevent incursion of foreign matter.  
         [0029]     If the electrode represented by sheath  60  and electrode  62  is sealed against contact with water, shorting between electrode  62  and electrode  54  will not occur due the presence of water. Thus, the ozone generator is resistant to damage due to flooding and it can readily be used in environments where flooding is a potential problem.  
         [0030]     The simplicity of the components eliminates any constraint on size. That is, not one of the parts/components must be especially made of a specific configuration for a specific size of the ozone generator. Thus, it is easily scalable to accommodate any ozone generating requirement or air flow requirement.