This invention relates broadly to air cleaning devices that remove airborne contaminants of many types, including, viruses, bacteria, mycotoxin, fungi, spores, allergen particles, odiferous molecules, Volatile Organic Compounds, and other Toxic Industrial Chemicals. More specifically, the invention relates to a device that utilizes electromagnetic energy to generate hydroxyl radicals on the surface of semiconductor material, thereby facilitating the removal of airborne contaminants.
There is a critical need to improve the air quality of inhabited areas by eliminating suspended contaminants. Sale of consumer air purifiers have risen dramatically worldwide since Sep. 11, 2001, because of civilian concern for epidemic pathogens (Avian Virus, SARS, Influenza), and their bio-engineered military grade counterparts (Plague, Smallpox).
Currently popular residential air purifiers electrostatically attract contaminant particles to an accumulation plate that has a negative electrical charge. The process of creating ions with an electrostatic field naturally creates a small air movement. Marketers have seized on this silent air movement feature to promote a quiet, but marginally effective product. Periodically, the accumulation plates become covered with highly concentrated contamination and must be discarded or cleaned, presenting a new consumer health risk. Despite their popularity and claims for low energy consumption, such units aren't particularly effective air purifiers according to published reports from consumer product testing laboratories.
Most suspended contaminants have a natural electrostatic charge present on them. Large macromolecules generally have a natural positive charge. For example, tobacco smoke particles, odors and many allergens tend to be positively charged, which helps keep these large particles suspended in air. Small microorganism particles typically have a negative charge on them. Bacteria and their fragments are negatively charged due to their cell wall chemistry. Gram negative bacteria contain negatively charged —COO* groups associated with proteins and lipopolysaccharides in their cell walls. Gram-negative bacterial endotoxins (pyrogens) are also negatively charged as are viruses and most colloids.1 The ability to place or alter an electrostatic charge on a suspended particle is directly related to its total surface area and its total mass. It is more difficult to alter or increase the natural electrostatic charge on a small contaminant particle than on a large particle.
1 Argonide Corp Nanocerm under Table 3 Filtration Mechanisms.
Consumer air purifiers tend to use the natural positive charge that large particles and molecules possess to attract them to a negatively charged collector plate. This negative collector generally minimizes the production of ozone by the devices, the concentration of which is regulated by governmental agencies because of its oxidizing toxicity to human lung material as well as to pathogens. Such consumer devices are inherently less effective at removing smaller bacteria and viruses, which are inherently negatively charged.
Electrostatic technology itself is fundamentally sound, and a mainstay of industrial effluent abatement. Very large, expensive, constantly maintained industrial systems are in use worldwide at industrial plants. These industrial systems generally use positively charged collector plates. They first increase the electronegativity of the generally large effluent particles by strong field ionization, then migrate the particles to large, parallel, positively charged collector plates. Byproduct ozone generated in the process is exhausted to the environment.
The present invention uses hydroxyl radicals from a photocatalytic reaction to molecularly dismantle pathogens and other contaminants suspended in a breathable airstream. The invention uses electromagnetic energy from conventional plasma discharge lamps in the ultraviolet 200 nm to 400 nm wavelength range to generate hydroxyl radicals on the surface of certain semiconductor materials. Hydroxyl radicals are very potent one-electron oxidants that steal hydrogen molecules from passing organic material, as they seek to replace their missing covalent electron, leaving decayed carbon ions in the organic matter.
There are several types of nanocrystal based semiconductor formulations that will express hydroxyl radicals on their surface via the dissociation of H2O ambient humidity water molecules into OH hydroxyl radicals. The water vapor is consumed, but cycled back to natural elements including water vapor. The end result of this photochemical conversion and air purification is eventually water and decayed carbon based material so that the cleaning is truly a bio-friendly process.
The presence of hydroxyl radicals on nanocrystal semiconductor surfaces can be confirmed by the use of a clear, colorless chromophore, Nitroblue Tetrazolium (“NBT”). NBT is a chemical substrate used in medical research to measure the bacterial killing ability of human neutrophils, primarily whether they are producing phagocytic singlet oxygen 1O2, normally generated in such healthy white blood cells of the immune system. Singlet oxygen is a powerful, endogenous oxidant, second to hydroxyl radicals in its thermodynamic oxidation potential. Singlet oxygen and hydroxyl radicals will both reduce colorless NBT solution to an indigo dye-based chloride salt precipitate, thereafter displaying a deep blue visible color if either has been present to cause the reaction.
The invention eradicates suspended contaminants in the air of enclosures that may still be occupied by people, plants and livestock and to the reduction of industrial airborne pollutants currently being exported to the environment. More particularly, this invention separates suspended contaminants by migrating them to an activated surface, then structurally dissociates them to the molecular level in a device that is self-cleaning and causes no environmental harm. All of the powerful dismantling agents used in the eradication process return to the natural elements from which they were made once their job is done, never escaping the device and causing no environmental harm.
Accordingly, it is a primary object of the present invention to provide a new and improved method and apparatus for destroying contaminants thereby.
It is a further object of this invention to permit operation of the method and apparatus while people, pets, plants, or livestock may be present in the air being treated.
It is a further object of this invention to improve breathable air and in so doing, use no ingredients and leave no residue that could be harmful to the environment.
It is a further object of this invention to separate and migrate suspended contaminants to an eradication site that is self-cleaning.
It is a further object of this invention to eradicate all migrated contaminants by structural dissociation of their cellular or chemical makeup, converting them to non-threatening forms, down to the level of natural environmental molecules.
It is a further object of this invention to amplify the dismantling effect itself by migrating ambient water molecules to a dismantling site to enhance the proximate raw material needed to enhance total photocatalytic activity.
It is a further object of this invention to provide several apparata embodiments for carrying out methods that achieve the foregoing objects and which are relatively simple in construction and effective in operation.
It is a further object of this invention to provide such methods and apparata that can easily be used in either a portable configuration by one person, or permanently incorporated into the conventional air handling systems of industrial and residential buildings.
It is a further object of this invention to provide such methods and apparata that can be permanently incorporated into the air handling systems of transportation vehicles such as aircraft, trains, and busses.
It is a further object of this invention to provide a method and apparatus that can be permanently incorporated into the air waste stream of industrial facilities and health care facilities in order to minimize toxic industrial chemical pollution and hazardous pathogen emissions to the environment.
These and other objects will be made manifest when considering the following detailed specification when taken in conjunction with the appended drawing figures.
The present invention provides a purification method and apparatus wherein contaminating particles suspended in breathable air are strongly migrated to an eradication site where they are molecularly dismantled into harmless fragments. The powerful nano-chemical agents to carry out the purification are generated on site from available natural elements, and are returned to those natural elements after their dismantling job is done, causing no environmental harm.
Dismantling Agent Creation On Site When activated by ultraviolet radiation with wavelengths shorter than 387.5 nm certain semiconductor nanoparticles produce a powerful molecular dismantling mechanism, hydroxyl radicals from ambient water molecules The hydroxyl radicals rob target molecule electrons from hydrogen atoms in the organic matter to restore their own covalent electrons lost to the energizing radiation. A colloidal suspension coating provides a stable, yet porous dry carrier structure to permanently suspend the nanoparticles, while permitting target molecules to move freely in and out of the nanoparticle matrix. The dismantling process generally applies to both gaseous chemical molecules (organic and some inorganic) and to micro-organic particles.
Invention's Optimal Use of Illuminating Radiation The present invention conformally surrounds the illuminating radiation with a dismantling surface that eradicates suspended contaminants by decomposition, thereby maximizing the use of illuminating radiation from conventionally shaped cylindrical light sources. The strength of the decontaminating process can be amplified by enhancing the migration of contaminants and ambient water vapor to the dismantling sites by electrostatic attraction.
Our research shows that ultraviolet radiation in the 250-270 nm range is very suitable for producing the photocatalytic mechanism, and for gaining the added feature of pathogen DNA/RNA destruction during the electrostatic migration step.
Internally Activated, Pathogen Migrating, Dismantling Rods This invention uses durable hollow light guides, coated with an outer layer of photocatalytic, dismantling, nanoparticles, energizing from below. These light guide dismantling rods are illuminated from within by UV radiation from an inner lamp radiating through the light guide walls to activate the photocatalytic coating from beneath. The dismantling rod purifies the contaminated air stream moving across its outer coated surface.
The light guide rod may be composed of quartz, fused silica or several other proprietary polymers (3M) that will serve for UV transmission and as the physical foundation for an active porous coating. Light guides may also be comprised of tetrafluoroethylene, (trade name Teflon). The material's extreme inertness to chemicals, low coefficient of friction, and ability to resist adhesion to almost any material, render it generally ideal for applications involving treatment of corrosive or combustible air flows. Coatings and photocatalytic activity can be on either the inside wall or the outside wall of the light guide.
Our research shows that the latter material is an excellent transmitter of the energizing spectral range of this invention, even when modified to accept coating adhesion.
The present invention uses a process analogous to Free-Flow Electrophoeresis to help separate the contaminant particles from the moving air stream, migrating them to an activated dismantling rod. The natural negative charge of microorganisms is used and strengthened. The natural positive charge of larger particles and macromolecules is reversed to net electronegativity by charging them with electrons produced in a negative corona discharge. A negative corona is created via a negatively charged electrode in the contaminated airstream. The generation mechanism of the negative corona is different from a positive corona. With the negative electrode at high voltage potential, electrons formed by chance ionizing events gain energy from the electric field and produce ions and other electrons by collision. The positive ions are accelerated to the cathode where they bombard the electrode surface and, as a result, electrons are released from the surface. The electrons move into the weaker electric field away from the cathode where they collide with contaminant particles and chemical molecules, as well as with neutral gas molecules to form negative ions. The discharge is dependent on the surface of the electrode for electrons, so the discharge occurs in small regions, or tufts, instead of in a uniform bluish glow characteristic of a positive discharge. This negative discharge is more stable, and can achieve higher voltages and currents than a positive corona before sparkover.
The gasses N2, CO2, and H2 have a much higher ionization potential than O2 or ambient H2O. The first three gasses tend to form positive ions in a positive corona, and (in a pure state) will not form negative ions by electron attachment. Therefore, electrons produced in a negative corona are more likely to form negative ions from O2 and H2O and to be available for attachment to large, positively charged contaminant particles to create their net electronegativity. This abundance of electrons in the corona is also more likely to dissociate passing O2 molecule into its two atoms, generating higher transient ozone levels than would be created in a positive corona. Ozone production levels are dependent upon several variables, including the field strength used and the interelectrode distance. Water molecules are strongly polar with a heavy oxygen atom and two light hydrogen atoms that are constantly exchanged between water molecules. Ionization produces separate ions of H+ and OH− which quickly form hydronium ions H3O+ and hydroxyl ions OH−, an intermediate for hydroxyl radical •OH formation at the dismantling grid.2
2 “Reactive Oxygen Species (ROS)”. Mar. 5, 2004. http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/R/ROS.html.
Cartridge Type Consumer Virus Eradicator
Ambient water vapor is converted to a surface field of hydroxyl radicals by the internal UV energy source 6, whose illumination passes through both the attracting screen 7 and outer wall 8, and is absorbed by photocatalytic coating 9 on outer wall 8.
The migrated contaminants are structurally dissociated and destroyed on the photocatalytic surface 9 of outer wall 8 where free radicals are generated. While the contaminants are being held there, the constantly replenished surface free radicals on 9 structurally dissociate the migrated, impacting contaminants into smaller and smaller fragments, eventually to natural stable molecules and harmless protein fragments. Purified air 5, (
DC voltage in the lower end of the range −3000 to −30,000 volts applied at very low current to the two electrode groups is adequate for negative ionization at 2 without significant ozone production. Electrons “boil off” the wires and by diffusion collide with, or may attach to, the microorganism contaminants, further strengthening their natural net electronegativity. The larger, positively charged surfaces of inorganic particles attract and bind colliding electrons from the negative corona and negative ions created in the interelectrode space; those tend to neutralize and reverse their natural positive surface charge.
All the current in the interelectrode space is carried by the resulting negative ions. Ambient water ions, ozone ions, and charged contaminants are transported toward the oppositely charged attraction screen 7 by the influence of the electric field strength on the contaminants' natural electrostatic surface charges, or by the combined influence between 2 and 7 if the ion generation field if it is switched on. The interelectrode space is also filled with the high intensity UV field radiating through the dismantling rod's wall. Any ozone molecules present are subject to photolysis (wavelengths below 310 nm) that produces singlet oxygen, which in turn may react with a water molecule to yield more dismantling hydroxyl radicals •OH.3
3 “The Hydroxyl Radical; Sources and Measurement.” Apr. 4, 1998. http://www.chem.leeds.ac.uk/Atmospheric/Field/oh.html.
Although most of the negative ions in the particle charging field are either attached to passing contaminants or are consumed by the attracting screen's opposite polarity, those that do escape the apparatus with purified air generally freshen the escaping, breathable air conveying a beneficial psychological effect on people who inhale that air.
An alternative of this embodiment is the reversal of voltages on the ion generator wires 2 (
Module For Abatement and Corrosive Environments
Such a cartridge is suitable for large scale placement in the air waste stream of industrial manufacturing facilities that emit corrosive pollutants or combustible effluents to the atmosphere. In our research light guides illuminated from within by such diffused longitudinal ionizing radiation, afforded amplification benefits over flat grids because of their 360 degree outer surfaces being available for contaminant attraction-dissociation.
This application claims priority from provisional filing No. 60/751,547 “Airborne Virus Eradicator” filed Dec. 20, 2005, and provisional filing 60/751,546 “Consumer Virus Eradicator” filed Dec. 20, 2005.
Number | Date | Country | |
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60751547 | Dec 2005 | US | |
60751546 | Dec 2005 | US |