Patent Application
20100111792
The present invention relates to improvements in methods and apparatus for purifying air, and more particularly to such methods and apparatus which are specifically capable of removing pollutants that may be either particulate or gaseous in nature.
The air comprising earth's atmosphere supplies vital life-sustaining requirements for virtually all forms of life. Plants utilize the carbon-dioxide in the atmosphere, through the process of photosynthesis, to produce sugar in the presence of sunlight, and expel oxygen as a waste product. The gills of a fish provide a means for extraction of oxygen from ocean water as well as excretion of carbon dioxide as waste—a natural filtering system—while certain aquatic animals absorb adequate amounts of oxygen through the surface of their bodies. It is well-known that oxygen levels in ocean waters are tied to the oxygen in the atmosphere, despite the prolific oxygen-production capability of the ocean's phytoplankton.
The need for clean air for human respiration became an important issue after World War II, with concerns regarding radioactive fallout, and because of the effects of London's “Great Smog” of 1952, which is generally regarded as the most significant early air pollution episode in history, where over 100,000 became ill and hundreds of thousands were reported to have died prematurely due to the release of sulphur dioxide from burning low-grade coal. The U.S. Congress thereafter passed the Air Pollution Control Act of 1955, followed by a series of other “Clean Air Acts,” and in 1970, President Nixon signed the law creating the Environmental Protection Agency, which was to safeguard the natural environment—air, water and land.
While progress has been made, the U.S. and other nations—particularly China and India—still rely heavily on the coal-fired generating plant. These coal-burning plants emit lead, mercury, arsenic, and millions of tons of carbon dioxide and soot annually, which are known to drift thousands of miles. Even where governmental regulation effectively controls the output of effluents into the environment, the possibility of accidental release remains a threat, and is starkly illustrated by the industrial disaster in Bhopal, India, where some 42 tons of toxic pesticide gas was accidentally released, resulting in 3,787 confirmed deaths.
Pollutants affecting the ordinary American household daily may include industrial pollutants just described, as well as dust; pet dander; mold; pollen; plant spores; bacteria from bird droppings; tobacco smoke; and auto emissions in the form of unburned hydrocarbons, nitrogen oxides (NO, NO2, N2O, N2O3, N2O4—NOx), carbon monoxide, and carbon dioxide. Where ozone in the upper atmosphere is necessary to block cancer causing high energy ultraviolet light from the sun, automobile hydrocarbons can react in the presence of NOx to produce ground-level ozone, which itself is carcinogenic.
The human body has some inherent tolerance to pollutants, and the hair in the anterior nasal passage plus cilia in the nasal cavity—which transports mucus—even serve to filter certain particulates from the air that enters a person's lungs. But many pollutants, including ozone, while possibly not concentrated enough to cause death or cancer, may cause respiratory disease, cardiovascular disease, throat inflammation, chest pain, congestion, and other ailments. So it is not surprising that there are many U.S. patents pertaining to air purification.
There is wide range of techniques that have resulted in the issuance of patents, such as U.S. Pat. No. 3,747,300 to Knudson. The Knudson approach uses three filters—“a mechanical filter element . . . , an activated charcoal filter element . . . , and an electrostatic air precipitator filter element.” The mechanical and charcoal filters provide conventional filtering, and the electrostatic air precipitator contains charging electrodes that electrically charge particles, which are then removed by electrostatic attraction to the collecting electrodes. Similarly, filtering according to U.S. Pat. No. 4,980,796 to Huggins occurs with an electric field generated by a charged screen that emits charged electrons, and “by ionizing the particulate which then flows to the floor under gravitational and/or electrostatic forces.”
Purification according to U.S. Pat. No. 4,337,071 to Yang occurs when an “apparatus that produces cryogenic temperatures is used to remove, by condensation, all pollutants in the air.” U.S. Pat. No. 4,210,429 to Goldstein provides a room air purifier in the form of “a high efficiency filter disposed in the housing for trapping small particles down to 0.3 microns” and “at least one ultraviolet lamp means disposed therein for killing viruses and bacteria flowing through the germicidal chamber.”
Many of these techniques serve to either filter particles, including the HEPA filter of U.S. Pat. No. 5,225,167, and/or provide ultraviolet germicidal lamps. Far less numerous are issued patents which address gaseous pollution instead of particulates.
Not surprisingly, some of the prior art has dealt with unwanted gaseous contaminants being removed by using the natural process whereby plants take up carbon dioxide and give off oxygen. U.S. Pat. No. 5,180,552 to Saseman provides for passing of room air up through potting soil, which contains carbon granules and sphagnum moss, and through the root system of living green plants, and claims to effectively remove “compositions from the class consisting of aliphatic and aromatic aldehydes and ketones, halogenated hydrocarbons, and cyclic hydrocarbons.”
In a more time-efficient process, U.S. Pat. No. 5,908,494 to Ross includes a spray purification apparatus to inject an “acid-neutralizing alkali aqueous solution” which is used “to wash the contaminants from the airstream, followed by a mechanical drying of the washed airstream.” The apparatus claims effectiveness in the removal of “nitrogen oxides, sulfur dioxide, hydrogen sulfide, hydrochloric acid, carbon dioxide, carbon monoxide and ozone.” This process, however, requires necessary supporting apparatus of a fluid flow system for the aqueous solution in order to accomplish the spraying, drainage, and recirculation, making the system relatively complex and not autonomous due to the professional servicing that would regularly be required.
The invention disclosed herein accomplishes cleansing of particulates and gaseous contaminants for a high volume of air in a robust, easily maintained system.
It is an object of the invention to provide a means for purifying air.
It is another object of the invention to provide a method for removal of particulates from room air.
It is a further object of the invention to provide a process to remove gaseous contaminants from room air.
It is another object of the invention to provide a robust method of air purification capable of purifying substantial volumes of room air.
It is also an object of the invention to provide a purification system that is and easy to maintain.
An apparatus for removing contaminants from air, including nitrogen oxides, carbon monoxide, carbon dioxide, and sulphur dioxide is disclosed. Polluted air may enter a first chamber through an inlet port. The first chamber, and all of the succeeding chambers, may contain sensors to measure certain properties of the incoming air flow, such as air flow rate in cubic feet per minute (CFM), inlet pressure, static pressure, pressure differentials, temperature, and relative humidity. The first chamber leads to a first activated charcoal filter which may filter particulate matter. The first activated charcoal filter also serves as the interconnection to a second chamber in which a plurality of first lamp sources is mounted. The air is therein exposed to light at wavelengths less than or equal to 242.3 nm to cause dissociation of contaminant molecules, creating ozone plus remaining atoms.
Dissociation is a process in which ionic compounds separate or split into smaller molecules, ions, or radicals. The process involves a disconnection of the bonds between atoms that hold a molecule together, and may occur only when the energy contained within a photon is released. But to achieve dissociation, the wavelength of light used must be selected to deliver photons that are compatible with the target contaminant molecules. A non compatible sized photon will not disassociate the bonds between the target molecules.
The flow of air, including the ozone plus remaining atoms resulting from dissociation, travel to the end of the second chamber and pass through a second activated charcoal filter. The remaining atoms are largely filtered by the second activated charcoal filter. The second activated charcoal filter is sized to have an appropriate thickness so as to achieve suitable dwell times of the air flow therein, to enable sufficient time for absorption of the remaining atoms. The second activated charcoal filter also serves as an oxygen rich medium, permitting the ozone generated in the second chamber to undergo atomic rearrangement through the process of molecular respiration. Atomic rearrangement of the ozone occurs with ozone molecules (O3) and atomic oxygen atoms (O) combining to form oxygen molecules (O2).
The second activated charcoal filter is also the interconnection to the third chamber, in which the air flow is then exposed to one or more second light sources. These second light sources emit light at wavelengths greater than about 242.3 nm but less than about 280 nm, which causes conversion of any remaining ozone into oxygen molecules. The air flow may pass through a third activated charcoal filter for system redundancy to further filter any remaining atoms and ensure that the pollution is eliminated. The third activated charcoal filter interconnects to a fourth chamber, which comprises an outlet port, as well as additional sensors. These sensors may also measure air flow rate, velocity, temperature, relative humidity, and pressure, but can also be used to measure any residual pollution in the purified air flow, which, when compared to pollution levels of the inlet air flow, would serve to identify system efficiency and provide notice for when maintenance of the apparatus may be needed, particularly for replacement of the activated charcoal filters and for the lamps. Sensors may be located in any or all of the chambers to provide data on pressure drops, as well as to provide data on lamp intensity.
The invention may be housed in a straight-line set of chambers in the form of a rectangular enclosure or a tubular duct. Alternatively, the invention could be configured to save space by having a bend after the second chamber, leading into the third and fourth chamber. Also, a blower may be incorporated to boost air flow, and additional lamps may be mounted to the interior of any enclosure to increase exposure of the air flow to the wavelength-specific light.
The apparatus 3 comprising a first embodiment may have a first chamber 10 that is formed by one or more walls 11. It should be pointed out that first chamber 10, as well as the entire apparatus 3 may be formed with various shaped walls to constitute a duct capable of containing a flow of air. The principles of this invention may be utilized regardless of the shape of the air-conducting enclosure, which may have, but is not limited to, a rectangular-shaped cross-section forming a box-like enclosure, or a circular-shaped cross-section that forms a tubular enclosure. The discussion for the first apparatus 3 will proceed with a description of the enclosure as a plurality of walls 11, which may be considered, to aid the reader when looking at
The plurality of walls 11 may include an inlet port 12 through which an inlet air flow 4 may be received into the apparatus 3. Inlet airflow 4 would constitute contaminated indoor/outdoor air being introduced into the apparatus 3 for purification. The plurality of walls 11 may include a solid baffle plate 14 that is without any openings so as to serve as a separation wall between first chamber 10 and other subsequent chambers, and thereby prevents intermingling of any of the discrete air flows herein described. The plurality of walls 11 forming chamber 10 should be sized and generally designed to ensure good air flow and air distribution for the particular service conditions. It should be pointed out that the principles of this invention may be incorporated for use in homes, industrial facilities, office buildings, automobiles, aircraft environmental control systems, and more generally into any heating/ventilating or air conditioning (HVAC) system. More particularly, apparatus 3, or any of the other embodiments offered herein, may be incorporated into a new building or added to an existing building to purify the outside air being drawn in for use by the occupants. In addition, the apparatus could be installed to the tops of buildings to purify air in major metropolitan areas that typically experience serious smog problems.
Chamber 10, as well as each of the other chambers discussed hereinafter that may follow chamber 10, may contain a plurality of sensors 16 to measure certain aspects of the incoming air flow 4, such as air flow rate in cubic feet per minute (CFM), inlet pressure, static pressure, pressure differentials, temperature, relative humidity, and lamp intensity. It would also be beneficial, in order to provide adjustments to the air flow rate and corresponding air dwell time per chamber, to have sensors measuring pollution levels in parts per million (ppm) for both the incoming air 4 and the purified air.
The plurality of walls 11 of chamber 10 may also include a first filter 15, positioned in the only air-permeable exit of first chamber 10 through which air flow 4 can pass. First filter 15 is optional. However, first filter 15, which may preferably be a carbon-based filter more preferably an activated charcoal filter, would serve to filter particulate matter at this stage, before the air flow undergoes purification. It is well known that a charcoal filter, being a form of carbon that has been processed to have high porosity, serves effectively to filter certain elements and particulates. Activated charcoal is charcoal that has been treated with oxygen to enhance its porosity. Filtration in the activated charcoal filter occurs by the high porosity providing bonding sites to attract and “absorb” chemicals. Once the filter has been in service for an extended period of time, all of the bonding sites may become full, and the filter will no longer attract and remove impurities from the air flow, at which time the filter should be replaced. Therefore, if apparatus 3 incorporates a first activated charcoal filter 15 and any other such filters, provisions must be made for its ease of installation and subsequent replacement into the plurality of walls 11 and solid baffle plate 14. Activated charcoal filter 15 is shown in
The first activated charcoal filter 15, as incorporated into apparatus 3, filters particulates from inlet air flow 4 to produce first filtered air flow 5. First activated charcoal filter 15, as incorporated into apparatus 3, interconnects the first chamber 10 to the second chamber 20, by providing the porous pathway. A different embodiment, which does not have first activated charcoal filter 15, would essentially have chamber 10 and second chamber 20 being merged into a single chamber. Chamber 20 may be considered to be formed of a plurality of walls 21, however, it may also be seen in
The second chamber 20 has one or more walls 21. A first activated charcoal filter 15 may be considered as forming one of a plurality of walls 21 of said second chamber 20. Additionally, solid baffle plate 14 may also extend beyond first chamber 10 to serve as one of the walls of second chamber 20, and thus continues to serve as an air-flow separation wall, separating second chamber 20 from the third chamber 30, which follows second chamber 20.
One of the key features of this invention is the light sources found in second chamber 20. Second chamber 20 incorporates one or more first light sources 22 that emit light only at specified wavelengths. Positioning one or several first light sources 22 that only emit a mid-range violet light, having wavelengths of less than or equal to 242.3 nm, will cause dissociation of targeted contaminant molecules.
Dissociation is a process in which ionic compounds—complexes (a “coordination compound” or “metal complex”), molecules, or salts—separate or split into smaller molecules, ions, or radicals. The process involves a dissociation of the bonds between atoms that hold a molecule together, and may occur only when the energy contained within a photon is released. To trigger this release, the photon must strike a molecule capable of absorbing the photon's energy.
To achieve dissociation, the wavelength of light used must be selected to deliver photons that are compatible with the target contaminant molecules. A non compatible sized photon will not disassociate the bonds between the target molecules. The appropriate wavelength of light that will cause dissociation is the size of the largest single photon the molecule could possibly carry, based on the energy it can absorb, to “excite” the atomic particles within the molecule. Too large of a photon can result in production of heat, radio waves, visual light, gamma rays, etc. The relationship between energy and frequency is referred to as Planck's Relation or the Planck-Einstein Equation: E=hv, where v is the frequency of the radiation, and h is Planck's constant whose units take the form of energy multiplied by time. Planck's constant is, in various different units, 6.62606896(33)×10−34 J·s (Joule-seconds), or 4.13566733(10)×10−15 eV·s (electron volt-seconds), or 6.62606896(33)×10−27 erg·s (erg-seconds). As an example, the energy of a 200 nm photon is thereby determined to be 10 to the minus 18th power (10−18). The light wavelengths selected to shine and produce dissociation of the chemical bonds of the contaminant molecules here will be 242.3 NM or smaller, which comprises only a fraction of the conventional UVC light (wavelengths of 280 nm-100 nm) that is often utilized for its germicidal effect (where UV long wave begins at 400 nm and generally runs down to 10 nm, and has energies from 3 eV to 124 eV).
In particular, in second chamber 2 of a first embodiment, there will be treatment of inorganic compounds, accomplished by dissociation of molecules that includes, but is not limited to, NOx, CO, CO2, and SO2, which will result in the formation of ozone (O3) and remaining atoms. In an alternate embodiment, the air may be treated to so as to only treat one or more specific chemicals from the group consisting of NOx, CO, CO2, and SO2.
Once the largest usable wave length of light that will produce the desired molecular respiration is known, which here will be 242.3 nm or smaller, lamp sources can be considered. First light source 22 could be a laser with compressed wavelengths, to shorten the spike and spreads its wavelength, and so have a wider range with a lesser intensity. The lamp source that today seems to be most efficient and economic is a mercury arc lamp, which may preferably be used in a preferred embodiment.
Exposure of first filtered air flow 5 to a plurality of first lamp sources 22 in the first embodiment produces the dissociated air flow 6, which includes both the formed ozone and the remaining atoms. It may be seen by looking at
Selection of the appropriate size activated charcoal filter is important for several reasons. The filter should be sized for a thickness that provides a minimal practical service life in terms of months or years of usage, and also provides the minimum thickness to produce suitable dwell times of the air to ensure that this process critical event reaches completion. Additionally, sizing of the filter must address the service conditions including, but not limited to, velocity and air flow rate. A benefit of a thicker filter is that it reduces the frequency of filter replacements needed and offers redundancy, lower maintenance costs, and less down time. Alternatively, a thinner filters benefits the draft inducer with a lower demand by placing a lower static pressure resistance or pressure differential across the filter for the same CFM and orifice size, than a filter of greater thickness. But a thinner filter will require more frequent replacements and or wash downs.
Another useful effect of second activated charcoal filter 23 is that the ozone that was generated during the second chamber 20 will exchange atoms within the filter, resulting in the atomic rearrangement of the ozone molecule (O3) and atomic oxygen atoms to form oxygen molecules (O2).
Second activated charcoal filter 23 serves to interconnect the second chamber 20 to a third chamber 30. The third chamber 30 may be formed of a plurality of walls 31, of which the second activated charcoal filter 23 comprises one of the walls, along with solid baffle plate 14. The third chamber 30 may incorporate one or more second light sources 32. The second light source 32 is selected to emit light at wavelengths greater than 242.3 nm but less than 280 nm. This range of light wavelength is selected as it will cause conversion of ozone into oxygen, so any ozone atoms not converted to oxygen molecules within the activated charcoal filter 23 will be acted upon. Should the wavelengths utilized approach a size greater than 280 nm, heat will also begin to develop proportionately as the increased size of the photons excite molecules being treated.
Looking at
As seen in
The third activated charcoal filter 33 also serves to interconnect third chamber 30 and a fourth chamber 40. Fourth chamber 40 serves as an outlet chamber and is comprised of a plurality of walls 41 of which the third activated charcoal filter 33 may serve as one of these walls. The plurality of walls 41 of the fourth “outlet” chamber 40 may also include an outlet port 42. Chamber 40 may also have sensors 47, which are comparable to sensors 16 in first chamber 10 as previously described. Sensors 47 may also measure air flow rate, velocity, temperature, relative humidity, and pressure. Furthermore, sensors 47 may be used to measure any residual pollution in the purified flow 9, which would serve to identify system efficiency, and provide notice for when maintenance of the apparatus 5 may be needed, particularly for replacement of the activated charcoal filters, but also for the lamps. The sensors providing measurements of both inlet and residual pollution levels may also be utilized to adjust the intensity of light being emitted from the lamps 22 and 32 to optimize treatment where there are higher pollution levels or greater flow rates of air due to higher demand.
In another alternate embodiment 3A, shown in
A second embodiment of the present invention is shown by apparatus 103 in
Apparatus 103 may be formed of ducting having a rectangular cross-section, but may also preferably be formed with a cylindrical exterior wall 111 having a first end cap 113 and a second end cap 114 (
With apparatus 103 so constructed, all of the processes—the dissociation of contaminant molecules of a first filtered air flow 105, the filtering of remaining atoms from the dissociated air flow 106 to produce scrubbed air flow 107, the conversion of ozone into oxygen molecules constituting converted air flow 108, and the final filtering to achieve purified air flow 109—are all comparable to those described for apparatus 3.
Apparatus 103 may additionally incorporate, into first chamber 110, a plurality of air dispersible baffles 150. The plurality of air dispersible baffles 150 may serve to direct the air flow into a more evenly distributed flow across the periphery of first activated charcoal filter 115, than might be otherwise obtained from the inlet air flow 104 of the small inlet port 112.
Also, in an alternate embodiment of apparatus 103, first chamber 120 and second chamber 130 may be combined so that both the first and second lamp sources are illuminating the air flow in a single enclosure.
A variation of the apparatus 103 may create a third embodiment of the invention (
Another variation of the apparatus 103 may create a fourth embodiment shown by apparatus 303 in
Finally, another variation of the apparatus 103 may create fifth embodiment in the form of apparatus 503, as shown in
The examples and descriptions provided merely illustrate a preferred embodiment of the present invention. Those skilled in the art and having the benefit of the present disclosure will appreciate that further embodiments may be implemented with various changes within the scope of the present invention. Other modifications, substitutions, omissions and changes may be made in the design, size, materials used or proportions, operating conditions, assembly sequence, or arrangement or positioning of elements and members of the preferred embodiment without departing from the spirit of this invention as described in the following claims.
This application claims priority on U.S. Provisional Application Ser. No. 61/192,599 filed on Sep. 19, 2008, the disclosures of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61192599 | Sep 2008 | US |
