Fiberglass dielectric barrier ionization discharge device

A bipolar ionization device in which fiberglass is used as the dielectric. In one embodiment, a fiberglass board is used, with the anode on one side of the board and the cathode on the other side of the board. A number of flat boards can be stacked, with spacing between them to allow air flow to scavenge ions, with stanchions providing both mounting and electrical connections to the ionization devices. In another embodiment, a fiberglass tube is used, with the cathode inside the tube and the anode outside the tube.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to air purifiers, and more specifically to bipolar ionization devices for use in heating, ventilation and cooling (HVAC) systems to reduce the number of air particulates and break down chemical compounds that cause odors.

2. Description of the Related Art

Indoor air environments frequently include suspended particulates, such as dust, dander, soot and smoke particles, pollen, mold, bacteria, and viruses. Indoor gases are also present, being released from building materials, home furnishings and nondurable goods. In office environments, the greater user of machines, such as photocopying equipment and the like, is especially problematic, as this equipment may emit volatile organic compounds.

These particulates can degrade the quality of the air, making it less pleasant and even dangerous to occupants of the space. Modern construction techniques that promote energy efficiency, such as insulating walls, ceilings, doors and windows, and wrapping buildings with air intrusion barriers, have created spaces that are so airtight that the buildings are unable to release the off-gas toxic elements.

In ordinary heating, ventilation and cooling (HVAC) systems, air is drawn through a filter, which is intended to trap particulates in the filter. However, traditional filters are only effective for large particles of at least 10 microns in size. While high efficiency particle air (HEPA) filters are more effective, they also have disadvantages, as they may quickly become clogged, requiring frequent changing to avoid overburdening the HVAC equipment. Because of the presence of contaminants in the air and the general inability of physical filters to remove the same, a condition known as “sick building syndrome” has developed. Various building codes designed to mitigate this syndrome have been introduced; for example, the American Society of Heating, Refrigeration & Air Conditioning Engineers (ASHRAE) recommends a minimum of 8.4 air exchanges in a 24-hour period (a 35% turnover rate). While commercial and industrial facilities generally meet that minimum level, their air quality may remain inferior. Furthermore, there are many houses that do not even meet such minimum levels. While greater turnover rates would increase the interior air quality, they would also reduce the buildings' energy efficiencies.

An alternative method to filtering involves the use of ionization generated from non-thermal plasma technology to remove contaminants from air. Ionization occurs where an atom or group of atoms loses or gains one or more electrons. An electrically neutral atom or molecule will have an equal number of electrons and protons. If an electron bound to an atom or molecule absorbs enough energy from an external source, it may exceed the ionization potential and allow the electron to escape its atomic orbital. When this occurs, the electron is lost, and an ion with a positive electrical charge, a cation, is produced. Electrons that are lost become free electrons. When a free electron later collides with an atom, it may be captured within an orbital. The gain of an electron by an atom or molecule creates an ion with a negative electrical charge, an anion.

The ionization of air, e.g., air in the Earth's atmosphere, results in the ionization of the air's constituent molecules, primarily oxygen and nitrogen. While the nitrogen in air is more plentiful than oxygen, oxygen is more reactive. Thus, oxygen has a lower ionization potential than nitrogen, allowing for oxygen cations to be formed with greater ease than nitrogen cations, and oxygen has a higher electro-negativity than nitrogen, allowing for oxygen anions to be formed with greater ease than nitrogen anions.

Ionization is known to break down organic chemicals into the basic molecular constituents of water, carbon dioxide, and related metal oxides. Thus, ionization has potential for cleaning indoor air, by eliminating chemical pollutants and their associated odors from the enclosed environment. Ionization also contributes to the reduction of particulate matter, by imparting a charge to those particles: the charge causes the smaller particles to agglomerate, or clump together, forming larger particles that then drop out of the air or become caught in a filter system.

Studies indicate that an overbalance of positive to negative ions (cations) may impair human health in a number of ways, such as by stimulating increased production of the neurohormone serotonin, which may lead to exhaustion, anxiety and depression. Positive ions are frequently found in offices where VDUs (visual display units) are used. Negative ions (anions) have a calming effect. Thus, a machine that cleans indoor air should seek to introduce negative ions into the airstream.

Various commercial products have been made including machines that incorporate bipolar ionization devices. The ionization of air may also produce ozone, O3, whose levels should be kept below standard limits. Therefore, there is demand for a system which provides a sufficient level of ionization to effectively address the contaminants in an airstream, and in which the levels of ozone can be controlled.

Under the circumstances, it would be highly desirable to use ionization technology for air treatment, and indeed there are many suppliers of bipolar ionization devices that are stand-alone devices used in specified locations, or centralized installations which are integrated into a building HVAC system. These devices are used in a way so that air circulated into and recirculated within the building can pass over the bipolar emitting devices. This can accomplish the goal of improving air quality, without mandating greater air exchange rates. Thus, an additional benefit of ionization treatment of indoor air is that it contributes to the efficiency of HVAC operations.

Commercially available bipolar ionization devices generally apply glass tubes as dielectrics. However, glass tubes are relatively fragile, encountering numerous mechanical failures during shipping, due to mishandling, and due to stress-related failures at higher ambient temperatures. In addition, the shape and arrangement of the glass tubes can in some instances impede the air flow, thus harming efficiency. Therefore, there is a need in the art for an improved, efficient bipolar ionization device with low manufacturing costs and a reduced mechanical failure rate. In addition, there is a need in the art for a bipolar ionization device with an aerodynamic shape that provides for more efficient air flow, allowing greater scavenging of ions and simplifying installation in a wider range of HVAC systems or stand-alone devices.

BRIEF SUMMARY OF THE INVENTION

The present invention discloses a bipolar ionization device for use with heating, ventilation and cooling (HVAC) systems and stand-alone devices, and providing low manufacturing costs, a reduced mechanical failure rate, and high efficiency.

In one embodiment, the bipolar ionization device includes a flat fiberglass-reinforced epoxy laminate board that serves as the dielectric. A thin layer of solid copper foil is laminated to one side of the board, forming a copper-clad laminate that serves as a cathode of the bipolar ionization device. The second side of the board is provided with an anode fabricated from a tightly woven metallic mesh or grid. The fiberglass board is much more durable than ionization devices using a glass dielectric, and can be produced at a low cost and high efficiency. In addition, the flat design simplifies the placement of the devices in a broad range of locations, with improved ion scavenging that allows further efficiencies.

In a second embodiment, the bipolar ionization device is designed around a fiberglass-reinforced epoxy laminate tube. Provided inside the tube is a metal cathode, which can be solid metal, or a mesh or perforated metal. Outside the tube, a metallic mesh or grid anode is provided. While this embodiment would not offer the improved ion scavenging that the flat design can offer, it would still be advantageous in terms of its mechanical strength, high efficiency, and low manufacturing cost. In addition, the tubular design would allow a retrofit of existing ionization systems that currently employ glass tube ionization devices.

Both the flat fiberglass board design and the fiberglass tube design are adapted for mechanical and electrical connectivity to an AC power supply. In the second embodiment of the fiberglass tube, the conducting terminal includes a power input terminal extending from the bottom surface of the end cap for providing current to the cathode via a current distributor. A stainless steel clip or wire from a second terminal of the power supply can be coupled to the anode to complete the circuit.

In the first embodiment in which the ionization device is designed on a flat fiberglass board, a preferred embodiment provides for a number of the ionization devices to be mounted on a set of three stanchions affixed to a terminal box. With each board forming a roughly rectangular shape, one narrow end of the boards will be supported by a first and second stanchion, with the other narrow end of the boards being supported by the third stanchion. In a preferred embodiment, the boards are notched to accommodate the mounting via the three stanchions. In another preferred embodiment, in addition to providing structural support for mounting, the first and second stanchion provide high voltage alternating current for the ionization devices, with the currents referred to in this application as HV+ and HV−. In yet another preferred embodiment, the third stanchion is designed to allow for easy mounting and dismounting of each board.

To facilitate understanding of the invention, identical reference numerals have been used, when appropriate, to designate the same or similar elements that are common to the figures. Further, unless stated otherwise, the drawings shown and discussed in the figures are not drawn to scale, but are shown for illustrative purposes only.

DETAILED DESCRIPTION OF THE INVENTION

One embodiment of the present invention is a ionization device for removing impurities, such as dust, pollen, mold, compounds producing noxious odors, among other undesirable particles from the air, that manifest themselves, illustratively, in ventilation systems of buildings, although such environment is not considered as being limiting.

Among the improvements in the tube of the present invention is the improvement in overall structural integrity.

Both the flat fiberglass board ionization device and the fiberglass tube ionization device provide for an anode and cathode which increase the ion output of the ionization tube. The mesh or grid used to form the anode is fabricated with a tightly woven mesh, which allows for more contact points to produce ions.

In addition to other benefits, the embodiment of the flat fiberglass ionization device results in a reduction in the resistance to airflow, allowing for a more efficient HVAC system.

Reference will now be made in detail to implementations of the invention, examples of which are illustrated in the accompanying drawings.

FIGS. 1-3illustrate an embodiment of an ionization device100in which a flat fiberglass-reinforced epoxy laminate board110serves as the dielectric. The fiberglass-reinforced epoxy laminate board110is preferably rated a FR-4 grade, a popular laminate grade that provides a good strength-to-weight ratio, providing electrical insulation with considerable mechanical strength. However, other materials that provide structural integrity, durability, and efficient operational performance can be substituted.

AsFIG. 1illustrates, the board110has a length120and width130that far exceed the thickness140. The board110thus has a top and bottom and four very short sides. The top, of length120and width130, is designated as anode115, and the bottom, also of length120and width130, is designated as cathode310. Ionization device100can be constructed on boards of a variety of shapes and sizes, including not only a rectangular shape, as shown, but also a square shape, a circular shape, elliptical shape, etc. The assignee of the rights to this invention intends to commercialize embodiments of ionization device100in a number of rectangular and circular shapes, and reserves the rights to other shapes. In a preferred rectangular embodiment, the length, width and thickness of board110is 17.5″×5.5″0.125″. However, this should not be considered limiting, as a wide variety of sizes and shapes are possible.

FIGS. 1 and 2illustrate the anode side115of the board110, withFIG. 1representing the assembled anode andFIG. 2representing an earlier stage of the anode before final assembly.FIG. 3illustrates the cathode310of the board110.

In an embodiment such as shown inFIG. 4, one or more ionization devices100can be mounted on first stanchion420, second stanchion430, and third stanchion440. To accommodate such an embodiment, and referring back toFIG. 2, board110includes concave notches240and250on one end of the board, and a single concave notch260on the other end of the board. First stanchion420is engaged by notch250of board110, second stanchion430is engaged by notch240of board110, and third stanchion440is engaged by notch260of board110.

FIG. 3presents a preferred embodiment in which cathode310is provided with a solid copper face320that covers most of the area of the bottom of board110. A border330of width340that is free from the solid copper face320surrounds the perimeter of cathode310. In a preferred embodiment, the solid copper face320has a thickness of approximately 1 ounce weight of copper per square foot, being approximately 1.34 mils or 34 micrometers, representing approximately 1 ounce of copper per square foot. In a preferred embodiment, width340is 0.5″. For corrosion resistance, solid copper face320is preferably provided with tinning. In an alternative embodiment, cathode310can be provided with a conductive material other than copper. In other alternative embodiments, cathode310can use a mesh or perforated metal in lieu of the solid face320shown.

With reference toFIG. 2, anode115of board110is provided with a tracing210of copper, preferably provided with tinning. Tracing210has width215and roughly follows the perimeter of the top of board110, inside of a border220with width225. In a preferred embodiment, the width225of border220is 0.5″, and the width215of tracing210is 0.25″. Anode115is also provided with a plurality of attachment dots280that are also copper, preferably provided with tinning. In a preferred embodiment, attachment dots280are 0.25″ in diameter. In a preferred embodiment, the copper of tracing210and attachment dots280have a thickness of approximately 1 ounce weight of copper per square foot.

The board110can be purchased from a manufacturer with copper already applied to both sides, and the copper can then be removed from unwanted areas by various subtractive methods leaving only the desired copper traces. Alternatively, the board110can be produced using an additive method where traces are adding to the bare substrate by electroplating methods.

In one embodiment, screen150, shown inFIG. 1, is tacked down to attachment dots280, as well as being tacked down to tracing210, as shown with small attachment dots285. The number and spacing of attachment dots280and285as shown is not intended to be limiting. Screen150is preferably aluminum or stainless steel, and is die cut to match the exact size and shape of tracing210. Screen150is provided with a plurality of interstitial spaces or perforations of approximately 180 to 290 openings per square inch. In one embodiment, the anode includes approximately 225 openings per square inch. With screen150tacked down and thus being in close contact to the dielectric, the ionization device yields a high ion output and a relatively low ozone production.

Ion and ozone outputs are affected by the thickness of the dielectric and the spacing of the screen150from the dielectric; by adjusting these two variables, ion and ozone outputs can be tailored to suit the application. Thus in another embodiment, not shown, conductive spacers are provided between tracing210and screen150, and between attachment dots280and screen150. In a preferred embodiment, the conductive spacers will add 7 mil spacing.

With reference toFIGS. 2 and 3, one preferred embodiment is that first stanchion420and second stanchion430not only provide structural support for board110, but also provide for the supply of HV+ and HV− alternating current to the ionization device100. Voltage for the anode115of the board110is supplied by the second stanchion430, at the intersection270between notch240and the second stanchion430. Voltage for the cathode310of the board110is supplied by the first stanchion420, at the intersection350between notch250and the first stanchion420.

Ionization device100is powered by a high voltage alternating current (ac). In a preferred embodiment, ionization devices100will be powered by 2000-3,000 volts ac, which can be supplied by a power transformer that raises a branch circuit from 120 or 220 volts ac up to 3,000 volts ac. Cathode310thus experiences one polarity from first stanchion420while anode115experiences the opposite polarity from second stanchion430. This leads to opposite charges to build-up on each side of the dielectric barrier, with the resultant electric field generating discharges in the form of plasma filamentary and surface dielectric barrier discharges (DBD).

As air flows over the ionization device100and the molecules in the air interact with the generated plasma, electrons are transferred between molecules, generating both positive and negative ions that propagate quickly, thus ionizing the air. Ionization of the air helps clean the air by breaking down organic chemicals and removing their associated odors, as well as reducing the levels of particulate matter through agglomeration.

In this preferred embodiment, the first and second stanchions provide HV+ and HV− voltage to the side of the board110indicated by width140. In a preferred embodiment, on cathode310, border330is interrupted at the intersection350of notch250and first stanchion420. Instead, solid copper face320extends to the edge of cathode310and over the edge, onto the side of the board110indicated by width140, making contact with the HV+ terminal of the power supply through the conductor of first stanchion420. Similarly, on the anode115, border220is interrupted at the intersection270of notch240and second stanchion430. Instead, trace210extends to the edge of anode115and over the edge, onto the side of the board110indicated by width140, making contact with the HV− terminal of the power supply through the conductor of second stanchion430.

FIG. 4illustrates an ionization system400in which a plurality of ionization devices100are mounted horizontally, with the anode (top) surface facing up and the cathode (bottom) surface facing down. In a preferred embodiment, ionization devices100are spaced 0.7″ from the top of a lower board to the bottom of an upper board. Ionization devices100are notched as discussed earlier, and fit into mounting and power stanchions420,430and440. The stanchions, in turn, are mounted to a baseplate on enclosure410, in which enclosure410may incorporate a power transformer and monitoring electronics (not shown). Ionization system400could be placed, for example, in an HVAC duct, providing ionized particles into the airstream.

FIG. 5is a perspective detail of first stanchion420, with first stanchion430being identical. Stanchions420and430comprise a plurality of modular insulators510surrounding a central conductor (not shown), which also provides structural support. Modular insulators510are provided with bore hole520to accommodate the central conductor. In a preferred embodiment, central conductor520is a #304 stainless steel threaded rod.

FIG. 6is a detail of a single modular insulator510. Each is roughly cylindrical, with radius615and height620. At the top of modular insulator510, a portion of the circumference is cut away to a depth630, with depth630being slightly larger than the thickness140of board110. The cut away circumference leaves a surface635above which is a convex v-shaped notch645that provides support for concave notches240and250of board110. At the top of modular insulator510is a convex hemisphere650, with the bottom of modular insulator510having a corresponding concave hemisphere (not shown). A bore hole640is supplied so that modular insulator510can be slipped over central conductor520. A plurality of modular insulators510can thus be stacked one of top of the other, with central conductor520preventing lateral movement of the modular insulators510, and the mating of the convex hemisphere650and concave hemisphere preventing rotational movement of the stacked modular insulators510.

A stanchion has a minimum of two modular insulators510, to retain a single board110, but by varying the height of central conductor520and the number of modular insulators510, a stanchion can be built to support any of a plurality of boards110. The threaded rod that forms the central conductor and structural support is cut to the appropriate length, depending on the number of modular insulators510. For five modular insulators, the rod would be approximately 80 mm long. It is envisioned that up to ten modular insulators can be accommodated. The Insulator510is Noryl plastic or equivalent. At the base of the stack of modular insulators, the threaded rod penetrates the baseplate on the enclosure. At the top of the stack of modular insulators, washers and nuts are used to retain top modular insulator510in place vertically.

FIG. 7is a perspective detail of third stanchion440which provides board110with structural support but does not provide it with any voltage. A plurality of rotating clips710rotates around a pivot720. Another stainless steel threaded rod is used to provide structural support for the third stanchion, though it does not serve a dual function as a power conductor. The top of each rotating clip710has a concave notch730provides space for board110.FIG. 8is a top view of third stanchion440, and shows that within concave notch730is a cam740. Cam740corresponds to the concave notch260of board110. Third stanchion440has a minimum of two rotating clips710, to retain a single board110, but by varying the number of rotating clips710, a stanchion can be built to support any of a plurality of boards110. At the base of the stack of rotating clips710, the threaded rod penetrates the baseplate on the enclosure. At the top of the stack of rotating clips, washers and nuts are used to retain top rotating clip710in place vertically.

With reference toFIG. 4, the lowest board110is slid into place with reference to the lowest convex notch645of stanchions420and430and gently pressed into place. The corresponding rotating clip710of stanchion440is then rotated so that cam740will enter into notch260of board110, pushing board forward approximately 0.1″ against convex notches645of stanchions420and430to compress board110into central conductor520and lock board110into place. The process is repeated for additional ionization devices100desired to be mounted in system400.

FIG. 9and detailFIG. 9show yet another embodiment of the present invention, being a bipolar ionization tube900. The bipolar ionization tube900includes a fiberglass tube910, an end cap950, a conducting terminal960, a cathode920, an anode930, a seal cap970, and at least one sealant for securing the end cap950and seal cap970to the fiberglass tube910.

The fiberglass tube910has an elongated cylindrical shape, with a wall of substantially uniform cross-section, forming an interior surface and an exterior surface. The fiberglass tube910has a first end and a second end. In a preferred embodiment, fiberglass tube910is preferably rated FR-4 grade. In one embodiment the outer diameter of the fiberglass tube can be approximately 0.75 to 1.625 inches, and is preferably about 1.375 inches. The thickness of the fiberglass wall forming the tube910is preferably 0.125 inches to 0.140 inches. In a preferred embodiment, the overall length of the fiberglass tube is 7 inches to 21 inches, although such lengths are not considered limiting. A person of ordinary skill in the art will appreciate that the dimensions of the fiberglass tube910are associated with the desired overall ion output and are not considered as limiting. The edge at the first end of the fiberglass tube910is seated into the end cap950, while the edge at the second end of the fiberglass tube910is seated into the seal cap970. End cap950and seal cap970are formed of an insulating material, such as vinyl.

Arranged against the inner wall of the fiberglass tube910is the cathode920. Preferably, the cathode920is formed from solid aluminum alloy and is cylindrical in shape. In a preferred embodiment, the alloy is 1100 H0 series. Although the cathode920is described as being fabricated from aluminum, a person of ordinary skill in the art will appreciate that other conductive metals or metal alloys can be utilized to form the cathode920, such as stainless steel and the like, and in lieu of a solid form, a mesh or perforated form can be used. A thin film of metal can also be created through a version of deposition, such as sputtering, chemical vapor deposition (CVD), etc.

The cathode920is sized to cover the interior surface of the fiberglass tube910, to about ¼″-½″ from the edge of the first and second ends of the fiberglass tube910, allowing enough space at the edges of the fiberglass tube910so that the edge of the first end of fiberglass tube910may properly fit into the end cap950and that the edge of the second end of fiberglass tube910may properly fit into seal cap970. In a preferred embodiment, the cathode920has a thickness of approximately 0.010 inches.

The anode930is arranged on the outer wall of fiberglass tube910. The anode930is cylindrical in shape and fabricated from a stainless steel mesh, which covers the exterior surface of the fiberglass tube910. Preferably, the anode930is approximately the same or slightly larger that the length of the cathode920. Although the anode930is described as being fabricated from stainless steel, a person of ordinary skill in the art will appreciate that other conductive metals or metal alloys can be utilized to form the cathode920, such as aluminum and the like.

In a preferred embodiment, the anode930has a thickness of approximately 0.14 inches, and225openings per square inch. Alternatively, the anode930can have a thickness in the range of 0.01 to 0.015 inches, and 180 to 290 openings (i.e., perforations) per square inch.

The anode930is electrically connected to a high voltage alternating current power supply with an electrical conductor (not shown), such as a stainless steel clip, wire, or other well-known electrical conductor. In one embodiment, a stainless steel clip extends from the HV+ lead of the high voltage power supply and is positioned to securely contact the outer surface area of the anode930.

The conducting terminal960includes a power input terminal962, a current distributor940with two tines980, fastener966and anti-rotation tab965for securing the current distributor940to the power input terminal962, and fastener964for securing the assembled conducting terminal960to end cap950.

The power input terminal962is made of a conductive metal, such as #304 stainless steel. The power input terminal962extends through a bore formed through the floor of the end cap950. The power input terminal962is mechanically and electrically connected to the current distributor940. In one embodiment, the bottom portion of the current distributor940includes a smooth bore sized to receive a threaded end of the power input terminal962. Fastener966for securing current distributor940to power input terminal962can be a nut, though different methods of fastening may be used, such as welding or screws in various configurations. Likewise, fastener964for securing the assembled conducting terminal960to end cap950can be a nut, though different methods of fastening may be used.

The power input terminal962extends a sufficient length from the external surface of the bottom portion of the end cap950to allow for connection to the separate high voltage alternating current power supply. The external end of the power input terminal962can be a threaded, as illustratively shown, although such terminal connector is not considered as limiting. For example, the power input terminal962can be of a plug-in or stab-on type connector, amongst other well-known connectors.

The current distributor940is shaped as a U-shaped tuning fork with two tines980that extend outward to contact cathode920. Current distributor940is fabricated from a conductive metal, such as stainless steel, aluminum, copper, among other conductive metals or metal alloys.

Similarly to the flat fiberglass board ionization device100, the bipolar ionization tube900can be installed, for example, in a heating, ventilation and cooling (HVAC) duct. During operation, the bipolar ionization tube900is connected to a suitable power source, such as a high voltage AC power supply. One polarity is supplied to current distributor940and is distributed to the cathode920by the current distributor940through its tines980. The opposite polarity is provided to anode930, such as by a conductive wire or clip provided between the anode and the power source. As described earlier, this leads to opposite charges to build up on each side of the dielectric barrier.

As air flows over the ionization device and the molecules in the air interact with the generated plasma, electrons are transferred between molecules generating both positive and negative ions that propagate quickly; thus ionizing the air. Ionization of the air helps clean the air by breaking down organic chemicals and removing their associated odors, as well as reducing the levels of particulate matter.

It is noted that the design of the anode and cathode, which includes the metals used for fabrication, as well as the increase in the number of perforations per square inch of the stainless steel anode mesh, are specifically directed towards increasing the ionization output in the surrounding air over the prior art. Likewise, the type of dielectric and its thickness, and the spacing between the dielectric and the anode are important in optimizing the ionization output. Advantageously, energy costs to operate the ionization tube900of the present invention can be reduced as compared to the tubes of the prior art, since the enhancements to the anode and cathode increase the overall ion production of the tube900.

Referring toFIG. 10, a method1000for fabricating the flat board ionization device100of the present invention is illustratively shown in the flow chart. The method1000starts at1005and proceeds to step1010, where the fiberglass board110is provided, having a top surface, a bottom surface, and at least one side.

At step1015, fiberglass board110is provided with first notch250, second notch240, and third notch260, to facilitate mounting of fiberglass board110, as well as to provide high voltage alternating current to the anode and cathode via electrical connections at240and250.

At step1020, either subtractive or additive methods are used to create copper cathode310on the bottom of fiberglass board110, except for a partial border around the perimeter of the bottom of fiberglass board110. At first notch250, the border is omitted and the copper continues to the edge of fiberglass board110and over the edge, covering part of the intersection of first notch250with the side of fiberglass board110.

In step1025, either subtractive or additive methods are used to create copper trace210on the top of fiberglass board110inside of a partial border220around the perimeter of the top of fiberglass board110. At second notch240, the border220is omitted and the copper trace210continues to the edge of fiberglass board110and over the edge, covering part of the intersection of second notch240with the side of fiberglass board110.

In step1027, copper cathode310is provided with tinning, with heavy tinning where the copper continues over the edge at first notch250. In addition, copper trace210is provided with tinning, with heavy tinning where the copper continues over the edge at second notch240.

At step1030, screen150is tack soldered to attachment dots280and to copper trace210at small attachment dots285, completing construction of anode115of the top of fiberglass board110.

The method1000then proceeds to step1030, where the method ends and any testing of the assembled ionization tube is provided.

Referring toFIG. 11, a method1100for fabricating the bipolar ionization tube900of the present invention is illustratively shown in the flow chart. The method1100starts at1105and proceeds to step1110, where the fiberglass tube910is provided.

At step1115, solid aluminum alloy cathode920is inserted into the interior of the fiberglass tube910. The cathode920is positioned such that the upper and lower edges of the cathode920are about ¼″-½″ from the edge of the first and second ends of the fiberglass tube910. As previously discussed for the apparatus, other conductive metals or metal alloys can be utilized to form the cathode920, such as stainless steel and the like, and in lieu of a solid form, a mesh or perforated form can be used. A thin film of metal can also be created through a version of deposition, such as sputtering, chemical vapor deposition (CVD), etc.

At step1120, conducting terminal960is assembled and installed on end cap950.

In step1125, a layer of sealant is applied to the circumference around the bottom of the inside of end cap950. Depending on the type of sealant, the sealant can be allowed to partially cure prior to proceeding to step1130.

At step1130, the first end of fiberglass tube910is slid over the conducting terminal960and slid downwards towards the end cap950until the peripheral edge of the tube910is firmly seated at the bottom of the inside of end cap950. The tines980of the current distributor940make contact with cathode920.

At step1135, the cylindrical stainless steel mesh anode930is slid over the second end of the fiberglass tube910. The upper and lower edges of the anode930are aligned to coincide with the respective upper and lower edges of the cathode920.

In step1140, a layer of sealant is applied to the circumference around the bottom of the inside of seal cap970. Depending on the type of sealant, the sealant can be allowed to partially cure prior to proceeding to step1145.

At step1145the peripheral edge of the second end of fiberglass tube910is firmly seated at the bottom of the inside of seal cap970.

The method1100then proceeds to step1150, where the method ends and any additional curing of the sealants and testing of the assembled ionization tube is provided.

A person of ordinary skill in the art will appreciate that the specific order of the steps of method1100is not considered limiting.

Although an exemplary description of the invention has been set forth above to enable those of ordinary skill in the art to make and use the invention, that description should not be construed to limit the invention, and various modifications and variations may be made to the description without departing from the scope of the invention, as will be understood by those with ordinary skill in the art, and the scope thereof is determined by the claims that follow.