CORONA DISCHARGE OZONE GENERATOR WITH INSULATOR-COATED CONDUCTORS
Cross-Reference to Related Applications
This application relates to and claims priority benefits from U.S. Provisional Patent Application Serial Nos. 60/141,646 filed June 29, 1999 and 60/179,211 filed January 31, 2000, each of which is incorporated by reference herein in its entirety.
Field of the Invention
The present invention relates to a method and apparatus for generating ozone by corona discharge, and more particularly to a corona discharge ozone generator having an insulator-coated conductive core and wound conductor associated with the conductive core.
Background of the Invention
Ozone (03) , also known as "Activated Oxygen," is an unstable gas which easily degrades to oxygen gas in the presence of heat or water. The production of ozone can be required for several applications, such as the treatment of drinking water or the sterilization of goods. One of the major benefits of ozone is that it can kill microbes such as bacteria, germs, or viruses without the use of toxic materials. Ozone is used in over 200 cities and over 3,000 state-of-the-art municipal water- treatment systems around the world. In fact, in 1991, the Environmental Protection Agency designated activated oxygen as the most effective primary disinfectant available for drinking water.
Ozone is created commercially through the use of ultraviolet light or by a corona discharge apparatus.
Both of these processes are well known in the art. A corona discharge apparatus consists of two electrodes connected to opposing ends of an electrical transformer, and a dielectric material placed in between the electrodes. Oxygen-containing gas, such as pure oxygen gas (02) or air, is then passed between the electrodes, creating a corona discharge.
The corona discharge splits the natural oxygen molecule into separate, highly active atoms. Some of these atoms combine with the nearest oxygen molecule, thereby forming ozone. Once formed, ozone, which is also unstable, seeks equilibrium by reacting with other surrounding molecules.
As mentioned, a corona discharge apparatus consists of two electrodes that are electrically connected to a transformer. Among the most frequently used methods of connecting items electrically is through the use of copper wire. Not only is copper cheap and abundant, but it is a good conductor of electricity, has a high melting point, and does not creep at connections. Copper is naturally compatible with itself, but is not compatible with aluminum or silver wires. Since circuit boards often utilize copper, the most effective method of electrically connecting the electrodes to the circuit board, and hence the transformer, is to use copper wire.
With that said however, prior art corona discharge apparatuses have not used copper wire because ozone reacts with the exposed copper to create copper sulfate. Since the build-up of copper sulfate corrodes, and eventually destroys, the copper wire, corona discharge apparatuses have used either aluminum or silver wiring. Thus, there has been a long felt need for a corona discharge apparatus that produces ozone that facilitates the use of copper wiring.
Brief Summary of The Invention
The preferred embodiments of the present invention address these needs and other concerns . In the preferred embodiment of the present invention, both the conducting core and the wound conductor are made of copper.
Likewise, copper wire is used to attach the electrodes to the circuit board, and hence, the transformer. Both the conducting core and the wire attaching the conducting core to the transformer are insulated with a material impervious to ozone, such as polytetrafluoroethylene. Although the insulating material slightly lowers the strength at which the electric field passes between the electrodes, the insulating material does not prevent the electric field from passing between the electrodes and dielectric materials.
In return, the use of an insulator allows the copper to be soldered directly to the circuit board and prevents the build-up of copper sulfate, thereby reducing corrosion. Furthermore, the use of insulation increases the safety of the apparatus since a user can touch the corona cell without being shocked or burnt.
These and other features of the present invention are discussed in the following detailed description of the preferred embodiments of the present invention.
Brief Description of The Drawings
FIG. 1 is a schematic view of an embodiment of the present invention;
FIG. 2 is a lateral view of the corona cell illustrated in Fig. 1 ;
FIGS. 3 and 4 are alternate embodiments of the corona cell shown in Fig. 2.
Detailed Description Of Preferred Embodiment (s )
FIGS. 1-4 illustrate a corona discharge ozone generator according to the present invention. The corona discharge apparatus 10 of Fig. 1 includes a corona cell 12, a circuit board 14, an electrical transformer 16, and wiring 18 and 20 attaching the corona cell 12 to the circuit board 14. The wiring 18 and 20 is soldered to the circuit board 14. Energy entering from an outside source, such as a household electrical socket (not shown) is converted by the transformer 16 and passed through electrical connections 13 on the circuit board 14 for use by the corona discharge apparatus 10. In the preferred embodiment of the present invention, the electrical connections 13 are made of copper. The corona cell 12 has two electrodes, the conducting cell 22 and the wound conductor 24. In the preferred embodiment, the conducting cell 22 is a ten (10) gauge copper wire, while the wound conductor 24 is a twenty-two (22) gauge copper wire. The wound conductor 24 is simply an extension of wiring 20 and is wrapped around the conducting cell 22. These electrodes are separated by a dielectric material 26. During ozone production, an electric field (not shown) travels between conducting cell 22 and wound conductor 24, and through the dielectric material 26. Oxygen-containing gas, such as pure oxygen gas (0 ) or air, is then passed between the conducting cell 22 and the wound conductor 24, creating a corona discharge.
The corona discharge splits the diatomic oxygen gas molecule into separate, highly active atoms. Given the instability of each oxygen atom, it immediately seeks equilibrium by combining with another oxygen atom(s) . Some of these atoms combine with the nearest diatomic oxygen molecule, thereby forming ozone.
In order for ozone to be produced, the electric
field between the conducting cell 22 and the wound conductor 24 must "excite" an oxygen molecule. Thus, to provide the most efficient process for producing ozone, the process must bring as many oxygen molecules into contact with the corona discharge zone. As shown in FIG. 2, an embodiment of the present invention has a cylindrical conducting cell 22 enclosed by a similarly shaped dielectric material 26. The wound conductor 24 follows the contour of the conducting cell 22. An alternate embodiment of the present invention is shown in FIG. 3. In this embodiment, the conductor cell 22 has a polygonal cross section. As the wound conductor 24 loops around the conductor cell 22, air gaps 30 form in between the lateral sides 32 of the conductor cell 22 and the wound conductor 24. This configuration increases the amount of air that comes into contact with the corona discharge zone, thereby increasing the amount of ozone produced.
Another benefit of the present invention is the addition of an insulating material 34 around one of the electrodes. As illustrated in FIG. 4, the conducting core 22 and wiring 18 are surrounded by an insulating material 34 that is impervious to ozone, such as polytetrafluoroethylene. As mentioned above, the electrical connections 13 of the preferred embodiment are made of copper. Since copper is naturally compatible with itself, but is not compatible with aluminum or silver wires, it is beneficial to use copper for the wiring 18 and 20. In the preferred embodiment, the insulating material
34 is applied to the conducting core 22 and wiring 18 in a two step process. First a gel form of the insulating material 34, mainly polytetrafluoroethylene, is applied to fill in any air gaps around the conducting core 22 and wiring 18. Then a second layer, this time as a shrink
wrap, is applied over the first layer, substantially sealing the exposed copper of both the conducting core 22 and the wiring 18.
This insulating material 34 prevents the ozone from reacting with the copper surfaces to produce copper sulfate, which can corrode or destroy the copper surfaces. Furthermore, the production of ozone around the conducting core 22 results in the output of large amounts of heat. However, the use of the insulating material 34 prevents the escape of this heat into the surrounding environment. Since this corona discharge apparatus 10 may be used in homes, the insulating material 34 can prevent the user, be it an adult or child, from being burnt if he or she comes in contact with the corona cell 12.
Although the use of the insulating material may weaken the electric field that passes between the conducting core 22 and the wound conductor 24, the electric field remains sufficient for the production of ozone for sterilization. Furthermore, the use of a polygonal cross-sectioned conducting core 22, as described above, can increase the strength of the electric field enough to offset the loss caused by the insulating material 34. While particular elements, embodiments and applications of the present invention have been shown and described, it will be understood, of course, that the invention is not limited thereto since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. It is therefore contemplated by the appended claims to cover such modifications that incorporate those features coming within the scope of the invention.