AIR PURIFICATION SYSTEM

Air purification apparatus is provided that removes undesirable substances, such as particulate materials, malodors, viruses, bacteria, fungi, and toxins, from the air present within an enclosed environment. The apparatus is switchable between a mode in which air immediately adjacent the apparatus housing is drawn in and purified, and a mode in which air remote from the apparatus housing is drawn in from a specific point within the enclosed environment through use of an elongate duct.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention generally pertains to air purification apparatus that removes undesirable substances, such as particulate materials, malodors, viruses, bacteria, fungi, and toxins, from the air present within an enclosed environment. The apparatus has the capability to draw in and process air from the enclosed environment generally as well as to draw in air from a specific localized space within the enclosed environment.

Description of the Prior Art

Aerosols comprising pathogenic and/or toxic materials can be generated by many kinds of processes. Certain medical and dental procedures are well known for generating aerosols that may contain harmful pathogens. In the particular context of dental procedures, the combination of compressed air and water can result in the generation of aerosols from the patient's oral cavity that contain bacteria and viruses. These bacteria and viruses, once liberated from the patient's body, can linger in the procedure room for hours or days and create hazards for office staff and other patients.

Extraoral dental suction systems have been proposed to capture these aerosols and remove the dangerous contaminants. In particular, these devices are bulky and occupy quite a bit of space in an operatory that is already filled with equipment. Many of these systems also do not have the functionality of being a “whole room” air purification system. Thus, when not being used during a procedure, these systems are switched off and do not provide ongoing air purification within the operatory. In order to address this, a second whole-room air purifier is required in addition to the extraoral suction system. This solution only exacerbates the problem of limited space within a standard dental operatory.

Similar problems exist in other medical environments, such as operating rooms, veterinary clinics, and other point-of-care facilities. Outside of the medical field, other industries could also benefit from point-source and whole-room air purification systems, including laboratory and manufacturing settings in which toxic materials are being handled.

Thus, a need exists in the art for an integrated solution to whole-room and point-of-procedure air purification in which both demands are addressed by a single device.

SUMMARY OF THE INVENTION

According to one embodiment of the present invention there is provided air purifying apparatus comprising a housing, a blower and filter media contained within the housing. The housing comprises at least first and second air inlets and at least one air outlet. The blower is operable to induce a flow of air within the housing. The flow of air is selectively directed along either a first flow path located between the first air inlet and the at least one air outlet or a second flow path located between the second air inlet and the at least one air outlet. The filter media is contained within the housing and positioned across the flow paths, such that the flow of air within the housing passes through the filter media. The filter media comprises an adsorbent, absorbent, and/or neutralizing material capable of removing one or more undesirable substances from the flow of air.

According to another embodiment of the present invention there is provided air purifying apparatus comprising a housing having first and second air inlets and at least one air outlet, a blower operable to induce a flow of air within the housing, an air diverter assembly, and filter media. The first air inlet is configured to generally draw air into the housing from an enclosed space in which the apparatus is located. The second air inlet is coupled with an elongate duct having a duct inlet and a duct outlet. The duct inlet is configured to be selectively positioned adjacent a localized region within the enclosed space and draw air into the duct from the localized region. The duct outlet is connected to the second air inlet. The blower is operable to induce a flow of air within the housing between either a first flow path located between the first air inlet and the at least one air outlet or a second flow path located between the second air inlet and the at least one air outlet. The air flow diverter assembly is configured to be switchable between a first configuration in which the first flow path is blocked and the second flow path is opened, and a second configuration in which the second flow path is blocked and the first flow path is opened. The filter media is contained within the housing and positioned between the first and second air inlets and the at least one air outlet such that air flowing through either the first or second flow path passes through the filter media. The filter media comprises a first filter section that includes metal oxide or metal hydroxide nanocrystalline particles capable of removing one or more undesirable substances from the flow of air, and a second filter section that includes a high efficiency particulate air (HEPA) filter.

According to still another embodiment of the present invention there is provided a method of removing contaminants from air. The method comprises inducing a flow of air within a housing of an air purification apparatus using a blower installed within the housing. The flow of air is selectively caused to enter the housing through either of a first or second air inlet and exit the housing through at least one air outlet. The flow of air, as it flows through the housing, is directed along either a first flow path located between the first air inlet and the at least one air outlet or a second flow path located between the second air inlet and the at least one air outlet. The flow of air is caused to pass through filter media contained within the housing and positioned across the first and second flow paths. The filter media comprises an adsorbent, absorbent, and/or neutralizing material capable of removing one or more undesirable substances from the flow of air.

While the drawings do not necessarily provide exact dimensions or tolerances for the illustrated components or structures, the drawings are to scale with respect to the relationships between the components of the structures illustrated in the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Turning toFIG. 1, an air purification apparatus10in accordance with an embodiment of the present invention is illustrated. Apparatus10generally comprises a housing12inside of which is contained filter media14,16and a blower18(see,FIG. 7) that is operable to induce a flow of air within the housing.

In one or more embodiments, the housing10comprises a top wall20, a bottom wall22, and sidewall structure24. Note, sidewall structure24may be comprised of a plurality of individual panels, some of which (e.g., panel26) may be detachable to expose an interior space28within housing12within which filter media14,16are located. The housing12comprises at least first and second air inlets30,32, which may be formed in top wall20, although this need not always be the case. Note, housing12can be configured with a plurality of air inlets (e.g., three, four, five, or more) depending upon the application for apparatus10. The housing12further comprises at least one air outlet34. In certain embodiments, the housing comprises at least one air outlet34formed in each of two, three, or more panels making up the sidewall structure24. In one or more embodiments, the at least one air outlet34may comprise a plurality of louvered openings36in the sidewall structure24, although this need not always be the case.

The first air inlet30and the at least one air outlet34define a first flow path along which air may flow through the housing. The second air inlet32and the at least one air outlet34define a second flow path along which air may flow through the housing12. The filter media14,16is positioned within housing12such that it intersects the flow paths and the flow of air within the housing12passes through the filter media14,16.

As shown inFIGS. 1 and 2second air inlet32is coupled with an elongate duct38having a duct outlet40(see,FIG. 7) and a duct inlet42. In this embodiment, duct38comprises a plurality of articulating segments that permit duct inlet42to be positioned adjacent a localized region (e.g., a specific point) away from housing12within an enclosed space in which apparatus10is located. For example, the enclosed space can be a dental operatory in which a dental procedure is occurring on a patient. During such procedures, aerosols are often generated and can spread throughout the entire operator in which a dentist, hygienist, and/or any assisting personnel are working on the patient. The articulating structure of duct38permits duct inlet42to be placed in close proximity to the patient's mouth so that any generated aerosols can be drawn into duct38and ultimately into the interior space28of housing12where it will pass through the filter media14,16. Although not illustrated, the elongate duct38may be provided with a separate damper or air flow control structure at or near duct inlet42to provide enhanced user control at the collection point.

In contrast, first air inlet30is configured to draw air into the housing12from the enclosed space in a much more general sense to provide whole-room or whole-enclosed space air purification. The position of first air inlet30with regard to housing12is usually fixed and not adjustable like duct inlet42. The operation of apparatus10and the function of each inlet is explained in further detail below.

FIGS. 3 and 4illustrate another embodiment of elongate duct38a.Duct38acomprises a plurality of corrugated segments44which renders the duct flexible along the majority of its length. The corrugated segments44permit the duct38ato assume almost any configuration so that duct inlet42can be placed and maintained in the desired location within the enclosed space. Regardless of the configuration of the duct, the elongate duct38may be secured to the second air inlet32by a flange46that is attached to top wall20, and may also comprise an outlet section48that extends into the interior space28.

As shown inFIGS. 5 and 7-9, apparatus10may comprise an air flow diverter assembly50that is configured to be switchable between a first configuration in which the first flow path is blocked and the second flow path is opened, and a second configuration in which the second flow path is blocked and the first flow path is opened. As illustrated, the air flow diverter assembly50comprises a shiftable gate member52attached to a control lever54. However, other configurations and structures can comprise assembly50, including electronically or mechanically controlled sliding louvers or plates, interchangeable housing top walls, caps for inlets30,32, or any other suitable means for selectively blocking and unblocking the first and second air inlets30,32thereby preventing or permitting air from being drawn therethrough. In one exemplary embodiment, the assembly50may comprise a top that drops in and covers at least one of the air inlets30,32. It is noted that such may require that the elongate duct38be detached from top wall20first. While in certain embodiments it may be preferred for air to be drawn into housing12through only one air inlet at a time, it is within the scope of the present invention for air to be drawn into housing12through both the first and second air inlets30,32simultaneously. Thus, the air flow diverter assembly50may also be configured to be switchable to a third configuration in which both the first and second flow paths are open simultaneously.

In one embodiment of the present invention, and as depicted inFIGS. 4 and 5, for example, the filter media comprises a first filter section or cartridge14that comprises an adsorbent, absorbent, and/or other neutralizing material. In preferred embodiments, the adsorbent or absorbent material comprises metal oxide or metal hydroxide nanocrystalline particles capable of removing one or more undesirable substances from the flow of air. The nanocrystalline materials may comprise, consist of, or consist essentially of nanocrystalline metal oxides and hydroxides, coated metal oxides/hydroxides (i.e., halogen coatings), doped metal oxides/hydroxides, surfactant coated nanocrystalline metal oxides and combinations thereof. The terms “metal oxides” and “metal hydroxides” as used herein collectively refer to all such materials that comprise, preferably as the principal constituent, a metal oxide or metal hydroxide material. Preferred nanocrystalline materials for use in connection with the present invention include the metal oxides and metal hydroxides of Mg, Sr, Ba, Ca, Ti, Zr, Fe, V, Mn, Ni, Cu, Al, Si, Zn, Ag, Mo, Sb, Cr, Co and mixtures thereof. Additional preferred nanocrystalline materials include coated nanocrystalline materials such as those disclosed in U.S. Pat. Nos. 6,093,236, and 5,759,939 (metal oxide coated with another metal oxide), halogenated particles such as those disclosed in U.S. Pat. Nos. 6,653,519, 6,087,294 and 6,057,488 (nanocrystalline materials having reactive atoms stabilized on the surfaces thereof, the reactive atoms including oxygen ion moieties, ozone, halogens, and group I metals), doped metal oxides and hydroxides such as silver doped alumina, intimately mixed metal oxides such as combinations of Mg, Al, and Ti, carbon coated metal oxides, and air stable nanocrystalline materials such as those described in U.S. Pat. Nos. 6,887,302 and 6,860,924 (nanocrystalline materials coated with a surfactant, wax, oil, silyl, synthetic or natural polymer, or resin), all of which are incorporated by reference herein. The nanocrystalline materials preferably present crystallite sizes of less than about 25 nm, more preferably less than 20 nm, and most preferably less than 10 nm. The nanocrystalline particles preferably exhibit a Brunauer-Emmett-Teller (BET) multipoint surface area of at least about 15 m2/g, more preferably at least about 70 m2/g, and most preferably from about 100-850 m2/g. It is noted that the nanocrystalline materials need not comprise single crystals, and hence have particle sizes that correspond with the indicated crystallite sizes. Rather, the nanocrystalline materials may comprise aggregates of pluralities of crystallites and have actual particle sizes (as measured across the largest dimension of the particle) that are larger, such as on the order of about 0.5 microns to about 5 mm, about 1 micron to about 2.5 mm, or about 10 microns to about 1 mm.

Generally, filter cartridge14comprises a first filter material that contains the adsorbent or absorbent materials, and optionally, a second filter material that is capable of removing particulate matter from the air flowing through apparatus10. The second filter material can be inter-dispersed with the first filter material or can be located entirely upstream or downstream therefrom. In certain embodiments, it is desirable to locate the second filter material upstream from the first filter material so that particulate matter dispersed within the air can be removed prior to coming into contact with the first filter material containing the nanocrystalline particles, so as to avoid clogging or blocking air flow to the particles.

The first filter material may comprise a porous woven or non-woven material in which the nanocrystalline particles are entrapped. The woven or non-woven material may comprise a synthetic resin foam or film containing the nanocrystalline particles. Exemplary woven or non-woven materials include natural fibers (e.g., cellulose, cotton, wool, etc.) and synthetic fibers (e.g., acrylic aromatic polyaramide, polyethylene, polypropylene, polyester, polyimide, glass, polyphenylene sulfide, bi-component fibers, etc.). The second filter material may comprise the same or similar material as used in the first filter material. The second filter material may also contain nanocrystalline particles or it may not. Exemplary materials for use as the second filter material include natural fibers (e.g., cellulose, cotton, wool, etc.) and synthetic fibers (e.g., acrylic aromatic polyaramide, polyethylene, polypropylene, polyester, polyimide, glass, polyphenylene sulfide, bi-component fibers, etc.).

FIGS. 6aand 6billustrate exemplary filter cartridges that may comprise the nanocrystalline particles. Turning first toFIG. 6a, cartridge14acomprises a pleated sheet56of non-woven material into which the nanocrystalline particles are substantially uniformly distributed. Preferably, the nanocrystalline particles are entrapped evenly throughout the non-woven material thereby maximizing the available surface area to come into contact with the air flow and also to avoid problems associated with uneven settling of particles post-manufacture of the cartridge14a.The ability to keep the nanocrystalline particles evenly distributed throughout the filter media indicates that the nanocrystalline particles are not simply applied as a loose powder to the filter. Rather, the particles and first filter material are formed in such a manner that the particles are entrapped and maintain a relatively constant local position within the filter material. In other embodiments, the first filter material comprises granules upon which the nanocrystalline particles are deposited as a coating. The granules may be nanocrystalline metal oxide/hydroxide particles themselves or may be another type of inert porous substrate such as activated carbon. The nanocrystalline particles may be applied to the granules as a plurality of coating layers in order to give a “time-release” odor-absorbance effect wherein subsequent inner layers would gradually gain exposure to the air being circulated through the filter by the air handling apparatus.

FIG. 6billustrates an alternate embodiment of a filter cartridge made in accordance with the present invention. Cartridge14bcomprises a honeycomb-like structure58that includes a plurality of discrete cells60with each cell containing a quantity of granular nanocrystalline metal oxide or metal hydroxide material62. The granules62are contained in the cells60by first and second sheets64,66of finely porous material. Sheets64,66may comprise woven or non-woven materials that are sufficiently permeable to permit air to freely pass therethrough, but do not permit the granules62to escape cells60. Thus, granules62are entrapped within cells60and remain substantially uniformly distributed throughout cartridge14b.Sheets64,66may also be made of material similar to the above-described first and second filter materials and be capable of filtering particulate matter from the air prior to passage through the honeycomb section58.

In certain embodiments according to the present invention, the nanocrystalline particles are present in the filter cartridge14at a loading of between about 50 g to about 1 kg per square foot (about 538 g to about 10.74 kg per square meter).

Other filter media that may be used with the present invention is described in U.S. Pat. No. 8,496,735, which is incorporated by reference herein in its entirety.

In embodiments of the present invention, the filter media may also comprise second filter section or cartridge16. Filter cartridge16is selected based on the target application for apparatus10. In one or more embodiments, the target application for apparatus10requires particulate removal. Therefore, filter cartridge16may comprise a high-efficiency particulate air (HEPA) filter section or cartridge. As used herein, a “HEPA” filter is any type of filter that meets the requirements stated in U.S. Department of Energy Standard 3020-2015. Generally, this this type of air filter can theoretically remove at least 99.97% of dust, pollen, mold, bacteria, and any airborne particles with a size of 0.3 microns (μm). In alternate embodiments, the target application for apparatus10may be chemical compound removal, rather than particulate matter removal. In such embodiments, a HEPA filter need not be employed. Instead, a filter material capable of adsorbing or absorbing the target chemical compound, such as a filter comprising activated carbon or a packed bed of nanocrystalline metal oxides or metal hydroxides, may be used.

Thus, in one or more embodiments, the filter media is capable of removing particles (i.e., dust, pet hair, lint, etc.) dispersed within the air, but also, due to the presence of the nanocrystalline particles, can remove and neutralize undesirable chemical and biological substances present in the air, such as odors, bacteria, viruses, fungi, and toxins. Common odors that may be removed by the inventive filter cartridges include those caused by a member selected from the group consisting of urine, feces, sweat, decaying biological material, pesticides, organic solvents, volatile organic compounds, and combinations thereof. U.S. Patent Application Publication 2009/0098016, incorporated by reference above, discloses further exemplary odor-causing substances that may be removed by the nanocrystalline particles used with the present filter cartridge. Additionally, the nanocrystalline particles have the ability to remove harmful non-odorous materials and substances from air within the enclosed space. Exemplary materials and substances include HCN, CO, and biological species like viruses, bacteria, toxins, and fungi.

One of skill in the art would recognize that the geometry of the filter cartridges14,16could be altered to suit the required application, such as, for example, a canister-type filter, round filter, etc.

As illustrated in the Figures, in one or more embodiments of the present invention, filter cartridge14is located above filter cartridge16, or, because the air flows within housing in a generally vertical direction from top to bottom, filter cartridge14is located upstream from filter cartridge16. Thus, air entering through either of the first or second air inlets30,32travels vertically downward within housing12, through filter cartridge14, and then continues in a vertically downward direction through filter cartridge16. Once the air has passed through filter cartridge16, the air flow direction may change so that it is discharged through openings36. However, in one or more embodiments, it is preferred that the air flow within interior space28, and particularly in that portion of interior space28that is bounded by filter cartridges14and16, the air flows in a vertically downward direction only.

As illustrated inFIG. 7, the bottom margin of interior space28can be defined by plate68. Plate68generally comprises a central opening so that air flowing through the housing can pass into blower18, but blower18is preferably positioned beneath and outside of interior space28. Therefore, the air flow direction within the interior space between the first and second air inlets30,32and the central opening of plate68is in a vertically downward direction.

In an alternate embodiment, separate filter cartridges14,16can be replaced by a single filter cartridge70as illustrated inFIG. 10. In certain embodiments, this combined filter cartridge can be located similarly within housing12as filter cartridge14, proximate blower18, although certainly other arrangements may be possible without departing from the scope of the present invention.

Filter cartridge70comprises a top sheet72of filter material, such as any woven or non-woven filter material described previously herein. Next to that is located a filter layer74comprising the nanocrystalline particles, according to any embodiment previously described herein. The pleated filter material ofFIG. 6ais shown merely for illustrative purposes. Next to filter layer74is a HEPA filter layer76, also constructed according to any embodiment previously described herein. By placing all of the filter layers72,74,76in a single filter cartridge70, the burden on the end user to service and maintain apparatus10is significantly reduced. It is noted, that the filter layer76need not always comprise a HEPA filter, but as described above, the filter layer can be selected to specifically address the target application for apparatus10, such as chemical adsorption or absorption.

In one or more embodiments, and as can be seen inFIG. 9, for example, apparatus10optionally comprises a UV-light assembly78operable to deliver UVC radiation onto the filter media. Generally, UVC radiation is ultraviolet light having a wavelength within the range of 100-280 nm. This short-wave radiation has germicidal characteristics, which makes it well suited for destroying or deactivating harmful biological substances, such as viruses, bacteria, and fungi.

In one or more embodiments, the UV-light assembly comprises a least one UV-light source80and at least one shield82positioned over the at least one UV-light source80and configured to shield the first and second air inlets30,32from exposure to the UVC radiation, namely so that the UVC light produced by light source80does not escape housing12. In certain embodiments, the amount of UVC light that escapes housing12is less than 100 μW/cm2. The light source80can be any device capable of emitting UVC radiation such as shortwave ultraviolet lamps, UVC LEDs, and ultraviolet lasers. Shield82is preferably a bent metallic sheet that is positioned immediately above the light source80, although other materials capable of absorbing or deflecting UVC radiation may also be used.

In one or more embodiments, it is preferable for the UV-light assembly80to be operable to deliver UVC radiation onto the HEPA filter. It is contemplated that the bulk of all particulate materials captured by the filter media will be captured and retained within the HEPA filter16. Therefore, UVC radiation emitted from assembly80can be used to prevent, inhibit, or otherwise reduce pathogen levels on the HEPA filter thereby keeping them from being reintroduced into the enclosed space as the air flow exits housing12via outlet34.

In certain embodiments, therefore, filter cartridge14is positioned between the air inlets30,32and the at least one shield82. In this embodiment, little or no UVC radiation is directed onto filter cartridge14. In certain embodiments, filter cartridge16is positioned between the UV-light source80and the blower18.

In embodiments in which the combined filter cartridge70is employed, the UV light source80directs UVC radiation onto sheet72and into filter layer74. Preferably, filter layer74is constructed so that at least a portion the UVC radiation penetrates filter layer74to reach HEPA filter layer76.

A control panel84may be provided on the front of housing12to provide for a power switch86, a blower speed control dial88, and a power port90. Power port90may comprise standard electrical receptacles and/or USB charging ports so that other devices also in use in the space in which apparatus10is located can be conveniently plugged in. Also, as can be seen inFIG. 2, a power supply port92is provided on the back side of housing12to provide power to apparatus10.

Apparatus10may also be provided with a set of casters94to permit the apparatus to be readily movable between enclosed spaces or different locations within the same enclosed space. Casters94may also have the ability to be locked to prevent apparatus10from being moved once in the desired location.

Apparatus10can be used in a variety of settings to provide contaminant removal from the air within a space. Apparatus10is highly useful in applications in which potentially hazardous aerosols are created, such as dental operatories, operating rooms, laboratories, and certain kinds of manufacturing facilities.

Methods according to one or more embodiments of the present invention comprise inducing an air flow within housing12using blower18that is installed within the housing. The air flow is then selectively caused to enter housing12through either (or both) of first and second air inlets30,32and then exit housing through at least one air outlet34. The air flow, as it flows through housing12, is directed along either a first flow path located between the first air inlet30and the at least one air outlet34, or a second flow path located between the second air inlet32and the at least one air outlet34. As the air flows through housing12, it is caused to pass through filter media14,16, which is positioned across both the first and second flow paths. As the air passes through filter media14, undesirable materials, such as pathogens, solid particles, liquid droplets, and odors, are removed. Thus, the air flow exiting through outlet34is of a greater purity than the air drawn in through inlets30,32.

The step of selectively causing the air flow to enter the housing12comprises shifting the air flow diverter assembly50between a first configuration in which the first flow path is blocked and the second flow path is opened, and a second configuration in which the second flow path is blocked and the first flow path is opened. As noted above, assembly50may also be configured to permit air to be simultaneously drawn into housing12via both inlets30,32. In certain embodiments, the air flows vertically through the apparatus10between the first and second inlets30,32and the one or more outlets34. In certain embodiments, blower18is capable of drawing at least 100, at least 150, or at least 200 cubic feet per minute of air through apparatus10. Thus, in the context of a small operatory as one may customarily find in a dental office, the air within the operatory can be circulated through apparatus10every minute or two or less.

In embodiments of the present invention in which a UV light assembly78is present, the UV-light assembly delivers UVC radiation onto least a portion of the filter media, and preferably onto at least onto HEPA filter16. In addition, UV light assembly78may also be configured to deliver disinfecting UVC radiation onto any exposed internal surfaces of housing12onto which particulate matter and pathogens may accumulate during operation of apparatus10.

Apparatus10is operable to both draw in air from the enclosed space generally (i.e., the air located proximate housing12) and from a specific point within the enclosed space that is remote from the housing12through use of the elongate duct38. When apparatus10is operating to draw in air through the second air inlet32, and hence, through duct inlet42, the duct inlet42is positioned adjacent to the point within the enclosed space. In the context of a dental operatory, the duct inlet42can be positioned adjacent the patient's mouth so that aerosols or other materials generated during the dental procedure can be drawn into duct inlet42and processed by apparatus10. When a dental procedure is not taking place that requires point specific air purification, apparatus10can be operated such that air is drawn in through first air inlet30so as to process and remove impurities that might generally be present within air of the enclosed space.

This methodology translates to other fields such as general medical and surgical procedures in which duct inlet42can be positioned adjacent the portion of the patient's body that is undergoing the procedure to draw in aerosols or particles from the patient's body that are generated by the procedure. In the context of laboratory usage, apparatus10can be used when working with noxious chemicals or biological agents to remove and sequester odors, fumes, solid particulates, or liquid droplets that may be generated during laboratory work by positioning duct inlet42adjacent the work site. When the lab work is completed, diverter assembly50can be switched so that air adjacent apparatus10is drawn in through first air inlet30.

Apparatus and methods according to the present invention can also be used in other industrial and service industry settings. For example, apparatus10can be used within enclosed spaces in which welding is occurring as duct inlet42can be positioned adjacent the welding site to draw in particulate matter and/or gases produced from the welding operation. Apparatus10can also be used in personal services settings such as nail salons, beauty salons, and spas to remove volatilized organic compounds and other chemicals, or other noxious odors or fumes that may be produced in the rendering of certain services. In addition, apparatus10can be used in kitchens and restaurants to eliminate odors produced during food preparation.

Note, these examples are provided by way of illustration, and there are many other applications that are contemplated by the present invention. Thus, these examples should not be viewed as limiting upon the scope of the present invention in any way.