Discharge Methods Utilizing Plate Electrodes
Patent #577,636--February 23, 1897
Andreoli, Emile. Apparatus for Producing Ozone.
This patent describes an apparatus for the commercial production of ozone which consists of a box formed by a series of seven metallic electrodes separated by dielectrics. Oxygen passed between these electrodes is ozonized by electrical discharge between the electrodes. The goal of the invention is to maximize ozone production by maximizing the surface of the electrodes and thereby maximizing the area of the glow discharge. The invention also minimizes the temperature of operation by contacting air or oxygen only briefly with the discharge.
Patent #955,818--April 19, 1910
Lohman, Anthony. Ozonizer.
This patent outlines an ozone generator which consists of flat aluminum plate electrodes separated by dielectric plates. The plates are connected to terminals of an alternating current circuit, and a discharge results between the two plates resulting in conversion of oxygen to ozone in the space between the plates.
figure 3: Diagram of Apparatus Detailed in US Patent #577,636
Patent #2,404,778--July 30, 1946
Allison, Donald K. Apparatus for Producing Ozone.
This patent is for a process which involves drawing air through a filter using a compressor. The air is compressed and then passed through a refrigerating unit or a heat exchanger where heat generated during compression as well as a large percentage of the water in the air are removed. The water is drained off through a drain valve. The dehydrated compressed air then passes through a valve to an air motor which drives a propeller within the ozonizing chamber of the apparatus. Inside the ozonizing chamber are sets of plate electrodes separated by dielectric material and connected to a high voltage transformer. The electrodes are cooled by a refrigerant such as water which circulates through a refrigerant supply pipe/refrigerant return pipe system within the arrangement. The air produced by the air motor is sent into the ozonizing chamber, is circulated by the propeller, and exits the chamber through a discharge line. Electrical discharges between the plate electrodes ozonizes the compressed air within the chamber.
Patent #3,623,970--November 30, 1971
Haas, Georg. Compact Ozonizer for Water Lines.
This patent describes a household ozonizer which kills bacteria and removes unpleasant tastes and odors from tap water. The apparatus involves using an electrolytic cell to produce oxygen which then passes to an ozonizer. The produced ozone is then injected into water to be treated. The oxygen produced by the electrolytic cell is sent through a moisture remover before being sent to the ozonizer which consists of plate electrodes connected to a high voltage source.
Patent #3,654,126--April 4, 1972
McNabney, Ralph, et al. Fluidized Bed Ozone Generator.
This patent discusses an ozone generator consisting of two or more parallel plate electrodes which are covered by dielectric plates made of glass. These dielectric plates function to distribute the electrical discharge uniformly in order to avoid sparking and current surges in the ozone generator. Each electrode is connected via lead wires to the secondary of a high voltage transformer. The primary is connected to a low voltage source of AC potential. A series of grounded electrodes, which are flat electrically conductive metallic electrodes, is spaced from the parallel plate electrodes. These grounded electrodes are hollow and water is circulated through them for cooling purposes. Oxygen or an oxygen-bearing gas is fed into the generator via a gas inlet at a pressure of about 1.6 atmospheres and enters the spaces between the electrodes. A fluidizable dielectric material such as sand, glass powder, or a powdered highly insulating plastic is contained within the spaces between the electrodes. As the oxygen gas flows through at proper rates, a fluidized dielectric bed is formed in the spaces between the electrodes. After the fluidized dielectric bed is established, a voltage is supplied to the electrodes to produce an electrical field between the electrodes. A silent electrical discharge is formed in the gaps between the electrodes, and oxygen gas streaming through these spaces is converted to ozone. The ozone-containing gas exits through an outlet and enters a separator.
Patent #3,801,791--April 2, 1974
Schaefer, Richard J. Ozone Generator.
This invention is an ozone generator which is made up of several pairs of plate electrodes inside a casing made of a moisture-resistant, ozone-resistant material such as silicone rubber. The use of silicone rubber reduces arcing between the electrodes and increases the lifetime of the ozone generator. The electrodes are metallic, and a pair of low-stress glass plates made of a glass other than borosilicate (Pyrex) are adhered by a moisture-resistant, ozone-resistant bonding material such as silicone rubber to the faces of the electrodes. The electrodes are positioned with the glass plates facing each other, and spacers hold the plates apart forming a chamber
through which oxygen or air may pass. A transformer is used to supply AC to the electrodes producing an electrical field which ozonizes the air between the electrodes.
Patent #3,872,313--March 18, 1975
Emigh, Willard F., et al. Ozone Generator.
This patent is a design for a plate discharge ozone generator. The ozonizer uses two groups of interleaved, relatively small reactor plates mounted inside a rectangular enclosure. The reactor plates are coated with a ceramic to form a dielectric and to prevent corrosion. Internal channels are included in the design of the reactor plates to allow a coolant to circulate inside. The enclosure in which the plates are mounted is created with two paired inlets and outlets. One of the inlet/outlet pairs allows oxygen or air to enter into the enclosure, and the corresponding outlet directs the oxygen/air/ozone mixture out of the ozonizer. The other inlet/outlet pair allows a refrigerant to circulate through the reactor plates.
Patent #3,973,133--August 3, 1976
Emigh, Willard F., et al. Ozone Generator.
This patent details an ozone generator which consists of two groups of spaced plate electrodes. The entire outer surfaces of the plates are coated with ceramic which serves as a dielectric. Channels carrying a refrigerant such as Freon run through the interior of the electrodes. This invention eliminates the use of dielectric posts used to space the plate electrodes apart. The dielectric plates are simply mounted with a small space between them. Dielectric posts used as spacers provide paths by which charges can "creep" between the plates. A "creep" distance is defined in the patent as "the distance through which electric charges from one plate can creep toward and onto the next adjacent plate when the two plates are at different potentials." This creeping of charges between the plates stresses the ceramic coatings on the plates, the coatings eventually break down, and a massive arc-over occurs between the plates. This invention claims to increase the safety and the lifetime of the ozone generator by eliminating dielectric spacers between the plate electrodes.
Patent #3,984,697--October 5, 1976
Lowther, Frank E. Corona Generator.
This patent outlines an ozone generator which consists of flat plate electrodes in parallel arrangement with fired-on coatings of porcelain enamel which serve as dielectrics. The electrodes are connected to an AC voltage source of sufficient voltage to generate a corona discharge, and an oxygen-containing gas passed between the electrodes is converted to ozone by the discharge. The apparatus produces large quantities of ozone at voltages of about 6 kV. The device is air-cooled. When the dielectric constant of the porcelain enamel coating and the thickness of the coating are at optimal values, ozone production is maximized.
Patent #4,034,229--July 5, 1977
Grosen, Walter, et al. Ozone Generating Apparatus.
This patent is for an ozone generator which utilizes a corona discharge between plate-like electrodes arranged in a stack. The first electrode has a dielectric plate evenly spaced from both it’s surfaces. A second electrode spaced from the dielectric plate is fluid cooled. A discharge in the space between the first electrode and the dielectric and in the space between the second electrode and the dielectric converts oxygen to ozone.
Patent #4,152,603--May 1, 1979
Imris, Pavel. Device for the Production of Ozone.
This patent describes an ozone generating apparatus which consists of three parallel evenly spaced plate-shaped electrodes. The ozonizer consists of an electrically non-conductive housing made of PVC, glass, or some other dielectric with grooves in which the electrodes fit. A grounded electrode is connected to a high-voltage transformer which is connected to an alternating-current source. Three bipolar electrodes are placed parallel to and evenly spaced from the grounded electrode. The bipolar electrodes also have spaces between them. A discharge tube is placed parallel to, spaced from, and above the third bipolar electrode. A corona discharge is formed between the electrodes, and ozone is produced from oxygen or an oxygen-containing gas within the apparatus.
Patent #4,320,301--March 16, 1982
Kogelschatz, Ulrich. Device for the Production of Ozone.
This patent is for an electric-discharge ozone-producing apparatus that uses plate or tubular type electrodes. As described in the patent, the ozonator consists of two flat plate or tubular electrodes that are mounted inside a case. The side of the outer electrode which faces the inner electrode is coated with a dielectric material. On top of the nonconductive layer facing the inner electrode are mounted several electrically conducting plates. The purpose of this design is to reduce the power consumption and increase the ozone production efficiency. To this extent, the electrically conductive plates that are mounted on top of the insulating plates are designed to form separate discharge islands. Of note is that this ozonizer is designed to work with ultra high purity oxygen.
Patent #4,545,960--October 8, 1985
Erz, Gerhard J., et al. Fluid Treatment System and Ozone Generator Therefor.
This patent is both a design for an air fed ozone generator and a means of using the ozone generator to purify fluids. The ozonizer uses a discharge method for the production of ozone by means of flat plate electrodes. The electrodes are housed inside an assembly such that the entire surface of the electrode is exposed to air circulating through channels. Furthermore, the electrodes are designed to prevent electrical discharge arcing and to prevent electrode degrading due to discharge arcing. The circulating pump of the generator is placed so as to accomplish the drawing of air into the reaction chamber and the mixing of air with a fluid to be treated by means of a delivery pipe that is connected to the upstream suction side of the fluid circulation pump.
Patent #4,606,892--August 19, 1986
Bachhofer, Bruno, et al. Ozone Generator of Stack-Type Design, Employing Round Plate- Electrodes.
This patent is a design for a water cooled ozone generator that uses stack type round plate high voltage electrodes. The purpose behind the design was to simplify the ozone generator without increasing its size and to improve the quantity of ozone that can be generated in a given amount of time. The plate electrodes of the generator are braced counter to one another by means of two pressure plates that are located exterior of the region defined by the stacked pairs of water cooled outer electrodes. Pairs of glass plates are located in between paired outer electrodes and a counter electrode is located inside each pair of glass plates. In this manner, two discharge spaces are formed for the production of ozone from oxygen.
Patent #4,650,648--March 17, 1987
Beer, Hans-Rudolf, et al. Ozone Generator with a Ceramic-Based Dielectric.
This patent is a design for a plate electrode ozone generator that uses a ceramic-based dielectric. The dielectric between the two electrodes of discharge ozone generators is used to increase the power density between the electrodes and thereby increase the ability of the generator to convert oxygen to ozone. While the use of a ceramic as a dielectric is not a new concept, the nature of the ceramic that is used to provide the dielectric in this generator type is claimed to provide an improvement over generic ceramic dielectrics. The ceramic is composed of dielectric powders of different grain size that are bound together by an artificial resin. In ordinary ceramic dielectrics, there is a continuous breakdown of the ceramic due to the stresses created by the discharge. While breakdown of the fine ceramic particles also occurs with the ceramic coating used by this device, the coarser particles are more difficult to dislodge and this limits the degree to which breakdown of the finer particles can occur over a given period of time.
Patent #4,666,679--May 19, 1987
Masuda, Senichi, et al. Ceramic Ozonizer.
In this patent, the ozonizer consists of ceramic plates on which are mounted flat metallic plate-like electrodes which are attached to a high frequency high voltage source. A corona discharge between the two electrodes, which forms when high voltage (3kV) is applied, converts oxygen in the space between the electrodes to ozone. The ceramic plates on which the electrodes are mounted serve as dielectrics. A third ceramic plate is mounted on one of the plates which supports an electrode and forms a space through which cooling fluid is passed.
Patent #4,816,229--March 28, 1989
Jensen, Craig J., et al. Ozone Aparatus.
This patent is for an ozone generator consisting of two metallic plate electrodes separated from each other by a space in which oxygen is converted to ozone by electric discharge between the electrodes. On the surface of the first electrode and in contact with the ozonizing chamber is an insulating ceramic plate. A high voltage is applied to the plate electrodes, and the resulting discharge results in the conversion of oxygen to ozone which is removed from the apparatus through an outlet. The ozone generator is equipped with a means of water-cooling the electrodes to prevent overheating. The invention features a method of removing moisture from air because in many applications, the dewpoint must be below 27 °F which means that the air must be only 1-2% humidity at 70 °F in order to produce significant yields of ozone. The air to be ozonized enters a drying apparatus consisting of a large capacity dryer followed by a small capacity dryer before it enters the ozonizing chamber. The drying apparatus is equipped with a complex moisture-sensing component which measures the moisture content of the air after it passes through each stage of the drying process.
Patent #4,818,498--April 4, 1989
Bachhofer, Bruno, et al. Ozone Generator Employing Plate-Shaped High Voltage Electrodes.
This patent is a design for a high voltage ozone generator of stack plate design similar to the design described in patent 4,606,892. In contrast to patent 4,606,892 which describes the outer electrodes as being "round plate-shaped" electrodes, patent 4,818,498 does not specify the planar geometry of the cooling electrodes other than to describe them as being "plate-shaped." Both of these patents originate from the same inventor and were filed on the same date with later patent having a more in depth discus about a flaw in the design and a possible solution. This problem originates from the vibration of the glass plate dielectrics that lie between the outer and inner electrodes which causes frequent breaking or cracking of the glass plates. This problem is solved by applying a layer of silica oil in between the outer electrodes and the dielectric so as to cause them to adhere to the outer electrodes and not vibrate at their natural frequency.
Patent #4,882,129--November 21, 1989
Andrews, Dana, et al. Ozone Generator Cell.
This patent is for a rectangular cell discharge ozone generator. The base of the rectangular ozone generator is formed by two thermally conductive water cooled solid metallic plates. In between the rectangular plates that form the base is a thin ceramic sheet that forms the dielectric material. In between the dielectric is a perforated electrically conductive metal sheet that includes a contact area. The electrically conductive inner sheet forms the discharge electrode and the perforations of the of the sheet are in a honeycomb pattern. The design
provides for a simplified cell type water cooled ozone generator that is designed to produce either an ozone/oxygen or ozone/air mixture.
Patent #5,370,846--December 6, 1994
Yokomi, Tetsasuke, et al. Apparatus and Method for Generating High Concentration Ozone.
This patent describes both a method and a technique for generating ozone by silent electric discharge. The device presented in the patent uses externally cooled electric discharge plates as the ozonizer. Essentially, the technique presented in this patent involves the mixing together of two ultra high purity gasses to influence ozone production. According to the patent, the best ozone production results occur when ultra high purity oxygen is approximately 90% of the total gas going to the ozonizer and an auxiliary gas (Ar, CO, N2,...etc.) constitutes the remaining gas volume. It is claimed by the authors of this patent that the technique presented by this patent solves the problem of decreased ozone conversion efficiency when ultra high purity oxygen is used.
Patent #577,636--February 23, 1897
Andreoli, Emile. Apparatus for Producing Ozone.
This patent describes an apparatus for the commercial production of ozone which consists of a box formed by a series of seven metallic electrodes separated by dielectrics. Oxygen passed between these electrodes is ozonized by electrical discharge between the electrodes. The goal of the invention is to maximize ozone production by maximizing the surface of the electrodes and thereby maximizing the area of the glow discharge. The invention also minimizes the temperature of operation by contacting air or oxygen only briefly with the discharge.
Patent #955,818--April 19, 1910
Lohman, Anthony. Ozonizer.
This patent outlines an ozone generator which consists of flat aluminum plate electrodes separated by dielectric plates. The plates are connected to terminals of an alternating current circuit, and a discharge results between the two plates resulting in conversion of oxygen to ozone in the space between the plates.
figure 3: Diagram of Apparatus Detailed in US Patent #577,636
Patent #2,404,778--July 30, 1946
Allison, Donald K. Apparatus for Producing Ozone.
This patent is for a process which involves drawing air through a filter using a compressor. The air is compressed and then passed through a refrigerating unit or a heat exchanger where heat generated during compression as well as a large percentage of the water in the air are removed. The water is drained off through a drain valve. The dehydrated compressed air then passes through a valve to an air motor which drives a propeller within the ozonizing chamber of the apparatus. Inside the ozonizing chamber are sets of plate electrodes separated by dielectric material and connected to a high voltage transformer. The electrodes are cooled by a refrigerant such as water which circulates through a refrigerant supply pipe/refrigerant return pipe system within the arrangement. The air produced by the air motor is sent into the ozonizing chamber, is circulated by the propeller, and exits the chamber through a discharge line. Electrical discharges between the plate electrodes ozonizes the compressed air within the chamber.
Patent #3,623,970--November 30, 1971
Haas, Georg. Compact Ozonizer for Water Lines.
This patent describes a household ozonizer which kills bacteria and removes unpleasant tastes and odors from tap water. The apparatus involves using an electrolytic cell to produce oxygen which then passes to an ozonizer. The produced ozone is then injected into water to be treated. The oxygen produced by the electrolytic cell is sent through a moisture remover before being sent to the ozonizer which consists of plate electrodes connected to a high voltage source.
Patent #3,654,126--April 4, 1972
McNabney, Ralph, et al. Fluidized Bed Ozone Generator.
This patent discusses an ozone generator consisting of two or more parallel plate electrodes which are covered by dielectric plates made of glass. These dielectric plates function to distribute the electrical discharge uniformly in order to avoid sparking and current surges in the ozone generator. Each electrode is connected via lead wires to the secondary of a high voltage transformer. The primary is connected to a low voltage source of AC potential. A series of grounded electrodes, which are flat electrically conductive metallic electrodes, is spaced from the parallel plate electrodes. These grounded electrodes are hollow and water is circulated through them for cooling purposes. Oxygen or an oxygen-bearing gas is fed into the generator via a gas inlet at a pressure of about 1.6 atmospheres and enters the spaces between the electrodes. A fluidizable dielectric material such as sand, glass powder, or a powdered highly insulating plastic is contained within the spaces between the electrodes. As the oxygen gas flows through at proper rates, a fluidized dielectric bed is formed in the spaces between the electrodes. After the fluidized dielectric bed is established, a voltage is supplied to the electrodes to produce an electrical field between the electrodes. A silent electrical discharge is formed in the gaps between the electrodes, and oxygen gas streaming through these spaces is converted to ozone. The ozone-containing gas exits through an outlet and enters a separator.
Patent #3,801,791--April 2, 1974
Schaefer, Richard J. Ozone Generator.
This invention is an ozone generator which is made up of several pairs of plate electrodes inside a casing made of a moisture-resistant, ozone-resistant material such as silicone rubber. The use of silicone rubber reduces arcing between the electrodes and increases the lifetime of the ozone generator. The electrodes are metallic, and a pair of low-stress glass plates made of a glass other than borosilicate (Pyrex) are adhered by a moisture-resistant, ozone-resistant bonding material such as silicone rubber to the faces of the electrodes. The electrodes are positioned with the glass plates facing each other, and spacers hold the plates apart forming a chamber through which oxygen or air may pass. A transformer is used to supply AC to the electrodes producing an electrical field which ozonizes the air between the electrodes.
Patent #3,872,313--March 18, 1975
Emigh, Willard F., et al. Ozone Generator.
This patent is a design for a plate discharge ozone generator. The ozonizer uses two groups of interleaved, relatively small reactor plates mounted inside a rectangular enclosure. The reactor plates are coated with a ceramic to form a dielectric and to prevent corrosion. Internal channels are included in the design of the reactor plates to allow a coolant to circulate inside. The enclosure in which the plates are mounted is created with two paired inlets and outlets. One of the inlet/outlet pairs allows oxygen or air to enter into the enclosure, and the corresponding outlet directs the oxygen/air/ozone mixture out of the ozonizer. The other inlet/outlet pair allows a refrigerant to circulate through the reactor plates.
Patent #3,973,133--August 3, 1976
Emigh, Willard F., et al. Ozone Generator.
This patent details an ozone generator which consists of two groups of spaced plate electrodes. The entire outer surfaces of the plates are coated with ceramic which serves as a dielectric. Channels carrying a refrigerant such as Freon run through the interior of the electrodes. This invention eliminates the use of dielectric posts used to space the plate electrodes apart. The dielectric plates are simply mounted with a small space between them. Dielectric posts used as spacers provide paths by which charges can "creep" between the plates. A "creep" distance is defined in the patent as "the distance through which electric charges from one plate can creep toward and onto the next adjacent plate when the two plates are at different potentials." This creeping of charges between the plates stresses the ceramic coatings on the plates, the coatings eventually break down, and a massive arc-over occurs between the plates. This invention claims to increase the safety and the lifetime of the ozone generator by eliminating dielectric spacers between the plate electrodes.
Patent #3,984,697--October 5, 1976
Lowther, Frank E. Corona Generator.
This patent outlines an ozone generator which consists of flat plate electrodes in parallel arrangement with fired-on coatings of porcelain enamel which serve as dielectrics. The electrodes are connected to an AC voltage source of sufficient voltage to generate a corona discharge, and an oxygen-containing gas passed between the electrodes is converted to ozone by the discharge. The apparatus produces large quantities of ozone at voltages of about 6 kV. The device is air-cooled. When the dielectric constant of the porcelain enamel coating and the thickness of the coating are at optimal values, ozone production is maximized.
Patent #4,034,229--July 5, 1977
Grosen, Walter, et al. Ozone Generating Apparatus.
This patent is for an ozone generator which utilizes a corona discharge between plate-like electrodes arranged in a stack. The first electrode has a dielectric plate evenly spaced from both it’s surfaces. A second electrode spaced from the dielectric plate is fluid cooled. A discharge in the space between the first electrode and the dielectric and in the space between the second electrode and the dielectric converts oxygen to ozone.
Patent #4,152,603--May 1, 1979
Imris, Pavel. Device for the Production of Ozone.
This patent describes an ozone generating apparatus which consists of three parallel evenly spaced plate-shaped electrodes. The ozonizer consists of an electrically non-conductive housing made of PVC, glass, or some other dielectric with grooves in which the electrodes fit. A grounded electrode is connected to a high-voltage transformer which is connected to an alternating-current source. Three bipolar electrodes are placed parallel to and evenly spaced from the grounded electrode. The bipolar electrodes also have spaces between them. A discharge tube is placed parallel to, spaced from, and above the third bipolar electrode. A corona discharge is formed between the electrodes, and ozone is produced from oxygen or an oxygen-containing gas within the apparatus.
Patent #4,320,301--March 16, 1982
Kogelschatz, Ulrich. Device for the Production of Ozone.
This patent is for an electric-discharge ozone-producing apparatus that uses plate or tubular type electrodes. As described in the patent, the ozonator consists of two flat plate or tubular electrodes that are mounted inside a case. The side of the outer electrode which faces the inner electrode is coated with a dielectric material. On top of the nonconductive layer facing the inner electrode are mounted several electrically conducting plates. The purpose of this design is to reduce the power consumption and increase the ozone production efficiency. To this extent, the electrically conductive plates that are mounted on top of the insulating plates are designed to form separate discharge islands. Of note is that this ozonizer is designed to work with ultra high purity oxygen.
Patent #4,545,960--October 8, 1985
Erz, Gerhard J., et al. Fluid Treatment System and Ozone Generator Therefor.
This patent is both a design for an air fed ozone generator and a means of using the ozone generator to purify fluids. The ozonizer uses a discharge method for the production of ozone by means of flat plate electrodes. The electrodes are housed inside an assembly such that the entire surface of the electrode is exposed to air circulating through channels. Furthermore, the electrodes are designed to prevent electrical discharge arcing and to prevent electrode degrading due to discharge arcing. The circulating pump of the generator is placed so as to accomplish the drawing of air into the reaction chamber and the mixing of air with a fluid to be treated by means of a delivery pipe that is connected to the upstream suction side of the fluid circulation pump.
Patent #4,606,892--August 19, 1986
Bachhofer, Bruno, et al. Ozone Generator of Stack-Type Design, Employing Round Plate- Electrodes.
This patent is a design for a water cooled ozone generator that uses stack type round plate high voltage electrodes. The purpose behind the design was to simplify the ozone generator without increasing its size and to improve the quantity of ozone that can be generated in a given amount of time. The plate electrodes of the generator are braced counter to one another by means of two pressure plates that are located exterior of the region defined by the stacked pairs of water cooled outer electrodes. Pairs of glass plates are located in between paired outer electrodes and a counter electrode is located inside each pair of glass plates. In this manner, two discharge spaces are formed for the production of ozone from oxygen.
Patent #4,650,648--March 17, 1987
Beer, Hans-Rudolf, et al. Ozone Generator with a Ceramic-Based Dielectric.
This patent is a design for a plate electrode ozone generator that uses a ceramic-based dielectric. The dielectric between the two electrodes of discharge ozone generators is used to increase the power density between the electrodes and thereby increase the ability of the generator to convert oxygen to ozone. While the use of a ceramic as a dielectric is not a new concept, the nature of the ceramic that is used to provide the dielectric in this generator type is claimed to provide an improvement over generic ceramic dielectrics. The ceramic is composed of dielectric powders of different grain size that are bound together by an artificial resin. In ordinary ceramic dielectrics, there is a continuous breakdown of the ceramic due to the stresses created by the discharge. While breakdown of the fine ceramic particles also occurs with the ceramic coating used by this device, the coarser particles are more difficult to dislodge and this limits the degree to which breakdown of the finer particles can occur over a given period of time.
Patent #4,666,679--May 19, 1987
Masuda, Senichi, et al. Ceramic Ozonizer.
In this patent, the ozonizer consists of ceramic plates on which are mounted flat metallic plate-like electrodes which are attached to a high frequency high voltage source. A corona discharge between the two electrodes, which forms when high voltage (3kV) is applied, converts oxygen in the space between the electrodes to ozone. The ceramic plates on which the electrodes are mounted serve as dielectrics. A third ceramic plate is mounted on one of the plates which supports an electrode and forms a space through which cooling fluid is passed.
Patent #4,816,229--March 28, 1989
Jensen, Craig J., et al. Ozone Aparatus.
This patent is for an ozone generator consisting of two metallic plate electrodes separated from each other by a space in which oxygen is converted to ozone by electric discharge between the electrodes. On the surface of the first electrode and in contact with the ozonizing chamber is an insulating ceramic plate. A high voltage is applied to the plate electrodes, and the resulting discharge results in the conversion of oxygen to ozone which is removed from the apparatus through an outlet. The ozone generator is equipped with a means of water-cooling the electrodes to prevent overheating. The invention features a method of removing moisture from air because in many applications, the dewpoint must be below 27 °F which means that the air must be only 1-2% humidity at 70 °F in order to produce significant yields of ozone. The air to be ozonized enters a drying apparatus consisting of a large capacity dryer followed by a small capacity dryer before it enters the ozonizing chamber. The drying apparatus is equipped with a complex moisture-sensing component which measures the moisture content of the air after it passes through each stage of the drying process.
Patent #4,818,498--April 4, 1989
Bachhofer, Bruno, et al. Ozone Generator Employing Plate-Shaped High Voltage Electrodes.
This patent is a design for a high voltage ozone generator of stack plate design similar to the design described in patent 4,606,892. In contrast to patent 4,606,892 which describes the outer electrodes as being "round plate-shaped" electrodes, patent 4,818,498 does not specify the planar geometry of the cooling electrodes other than to describe them as being "plate-shaped." Both of these patents originate from the same inventor and were filed on the same date with later patent having a more in depth discus about a flaw in the design and a possible solution. This problem originates from the vibration of the glass plate dielectrics that lie between the outer and inner electrodes which causes frequent breaking or cracking of the glass plates. This problem is solved by applying a layer of silica oil in between the outer electrodes and the dielectric so as to cause them to adhere to the outer electrodes and not vibrate at their natural frequency.
Patent #4,882,129--November 21, 1989
Andrews, Dana, et al. Ozone Generator Cell.
This patent is for a rectangular cell discharge ozone generator. The base of the rectangular ozone generator is formed by two thermally conductive water cooled solid metallic plates. In between the rectangular plates that form the base is a thin ceramic sheet that forms the dielectric material. In between the dielectric is a perforated electrically conductive metal sheet that includes a contact area. The electrically conductive inner sheet forms the discharge electrode and the perforations of the of the sheet are in a honeycomb pattern. The design provides for a simplified cell type water cooled ozone generator that is designed to produce either an ozone/oxygen or ozone/air mixture.
Patent #5,370,846--December 6, 1994
Yokomi, Tetsasuke, et al. Apparatus and Method for Generating High Concentration Ozone.
This patent describes both a method and a technique for generating ozone by silent electric discharge. The device presented in the patent uses externally cooled electric discharge plates as the ozonizer. Essentially, the technique presented in this patent involves the mixing together of two ultra high purity gasses to influence ozone production. According to the patent, the best ozone production results occur when ultra high purity oxygen is approximately 90% of the total gas going to the ozonizer and an auxiliary gas (Ar, CO, N2,...etc.) constitutes the remaining gas volume. It is claimed by the authors of this patent that the technique presented by this patent solves the problem of decreased ozone conversion efficiency when ultra high purity oxygen is used.