JP2012517862A - Ultraviolet light air treatment method and ultraviolet light air treatment apparatus - Google Patents

Abstract

The present invention relates to a method and apparatus for microbial control and / or sterilization / improvement of the environment. Typically, the above method involves, for example, hydration (in the form of water in solution or water molecules bound by covalent valence, van der Waals forces, or London dispersion forces), ozone, plasma species, and / or organic species. To produce purified hydrogen peroxide gas (PHPG) that is substantially free from microbial control and / or sterilization / improvement in the environment, more preferably both on the surface and in the air. In order to work, it is to release a gas consisting mainly of PHPG into the environment.

Description

Related applications

  This application is filed in US provisional patent application 61 / 152,581 filed February 13, 2009 and US provisional patent application 61 / 258,005 filed November 4, 2009. Claiming the benefit of the day, both of these applications are incorporated herein by reference in their entirety.

  The present invention generally relates to infection control and microbial control methodologies and related devices.

  Pathogenic fungi, mold, mildew, spores, and organic and inorganic contaminants are usually found in the environment. Microbial control and sterilization in the environmental space is desirable for health promotion. Many methods have been used in the past in attempts to purify air and sterilize surfaces. For example, it is already known that reactive oxygen species (ROS) generated by photocatalytic oxidation treatment can oxidize organic pollutants and kill microorganisms. More specifically, the end products of photocatalytic reactions such as hydroxyl radical, hydroperoxyl radical, chlorine and ozone are known to oxidize organic compounds and kill microorganisms. . However, known methods and devices have limitations due to safety issues as well as limited effectiveness.

  ROS is a term used to describe highly activated air that is obtained by exposing humid air in the environment to ultraviolet light. Light in the ultraviolet region emits a photon at a certain frequency, and when absorbed, this photon has sufficient energy to break chemical bonds. Ultraviolet light having a wavelength of 250 to 255 nm is usually used as a disinfectant. Ultraviolet light having a wavelength of approximately 181 nm or less to 182 to 187 nm is comparable to corona discharge in the ability to generate ozone. Both ozone treatment and ultraviolet light irradiation are used for sterilization in local water systems. Ozone is currently used to treat industrial wastewater and cooling towers.

  Hydrogen peroxide is generally known to have antibacterial properties and is used in aqueous solutions for sterilization and microbial control. However, attempts to use hydrogen peroxide in the gas phase have been hampered to date by technical hurdles for the production of purified hydrogen peroxide gas (PHPG). When the aqueous solution of hydrogen peroxide is evaporated, an aerosol of fine droplets composed of the aqueous hydrogen peroxide solution is generated. Various treatments to “dry” the evaporated aqueous hydrogen peroxide only produce hydrated forms of hydrogen peroxide at best. This hydrated hydrogen peroxide is surrounded by water molecules bonded by electrostatic attraction and London dispersion. Thus, the ability of hydrogen peroxide to interact directly with the environment by electrostatic means is significantly weakened by the bound water molecules, which effectively reduces the basic electrostatic structure of the encapsulated hydrogen peroxide molecules. Change it. In addition, the minimum concentration that can be achieved with evaporated hydrogen peroxide is usually well above the workplace safety limit of 1.0 ppm by the Occupational Safety and Health Administration (OSHA), so use this treatment in areas where people are present. Is inappropriate.

Photocatalyst was demonstrated to be suitable for the decomposition of organic contaminants in the _{fluid, TiO 2, ZnO, SnO 2} , WO 3, CdS, including _{ZrO 2, SB 2 O 4,} Fe 2 O 3, but are not limited to . Titanium dioxide (TiO ₂ ) is chemically stable, has a band gap suitable for activation by ultraviolet light or visible light, and is relatively inexpensive. Thus, the photocatalytic chemistry of titanium dioxide has been extensively studied over the last 30 years to remove organic and inorganic compounds from contaminated air and water.

  Photocatalysts can generate hydroxyl radicals from adsorbed water when activated with sufficient energy ultraviolet light, so when applied in the gaseous state, they can generate PHPG for release into the environment. There is a possibility that it can be used. However, existing applications of photocatalysts are focused on creating a plasma containing many different active species. Furthermore, most chemical species in the photocatalytic plasma react with hydrogen peroxide and suppress the generation of hydrogen peroxide gas by a reaction that decomposes hydrogen peroxide. Also, any organic gas introduced into the plasma suppresses the production of hydrogen peroxide by both the direct reaction with hydrogen peroxide and the oxidation products resulting from the reaction with hydrogen peroxide.

The photocatalytic plasma reactor itself also limits the production of PHPG for release into the environment. Hydrogen peroxide (reduction potential 0.71 eV) has a greater chemical potential than oxygen to be reduced as a sacrificial oxidant (reduction potential -0.13 eV), so it is as fast as it is produced by water oxidation. , It is reduced preferentially as it moves downstream in the photocatalytic plasma reactor.
Oxidation
Two-photon _{+ 2H 2 O → 2OH * +} 2H + + 2e -
2OH * → H ₂ O ₂
reduction
^{_{H 2 O 2 + 2H + +}} 2e - → 2H 2 O
In addition, some side reactions generate various species that become part of the photocatalytic plasma, which inhibits the generation of PHPG for release into the environment as described above.

The wavelength of light used to activate the photocatalyst is also energetic enough to photodecompose peroxide bonds in the hydrogen peroxide molecule, and also suppresses the generation of PHPG for release into the environment It is also an agent. Furthermore, implementations using light of a wavelength that generates ozone introduces another species into the photocatalytic plasma that decomposes hydrogen peroxide.
O ₃ + H ₂ O ₂ → H ₂ O + 2O ₂

  In practice, the application of photocatalysts is focused on generating a plasma and often includes ozone used to oxidize organic pollutants and microorganisms. Such plasmas are primarily effective primarily within the plasma reactor itself, with inherently limited chemical stability outside the plasma reactor itself, and the limited amount of hydrogen peroxide gas that the plasma can contain is active. Disassembled into Furthermore, since the plasma is primarily effective within the plasma reactor itself, many designs maximize residence time to promote more complete oxidation of organic contaminants and microorganisms as they pass through the plasma reactor. Since hydrogen peroxide has a high potential to be reduced as described above, the maximized residence time will minimize the amount of hydrogen peroxide produced.

  Also, most of the applications of photocatalysis produce chemical species that are environmentally undesirable. The first of these species is ozone itself, an intentional product of many systems. In addition, organic contaminants that pass through the plasma reactor are hardly oxidized in a single exposure, and multiple air exchanges are required to fully oxidize to carbon dioxide and water. When incomplete oxidation occurs in the plasma reactor, a mixture of aldehydes, alcohols, carboxylic acids, ketones and other partially oxidized organic species is produced. Often, photocatalytic plasma reactors can actually increase the total concentration of organic pollutants in the air by breaking large organic molecules into multiple small organic molecules such as formaldehyde.

  In summary, the production of PHPG for release into the environment has not been achieved with the prior art. The method of evaporating the hydrogen peroxide solution, at best, produces only a hydrated form of hydrogen peroxide. Photocatalytic systems can also produce hydrogen peroxide, but they have multiple limitations that severely suppress the production of PHPG for release into the environment.

  In one aspect of the present invention, a method for microbial control and / or sterilization / improvement of the environment is disclosed. Typically, this method involves (a) providing a photocatalytic sail that preferentially produces hydrogen peroxide gas, ie, an air permeable form such as sail, and (b) hydration (eg, water in solution). Or purified hydrogen peroxide gas (PHPG) that is substantially free of ozone, plasma species, and / or organic species), or the form of water molecules bound by covalent valence, van der Waals forces, or London dispersion forces). And (c) a gas consisting mainly of PHPG so that the PHPG acts in the environment, more preferably both on the surface and in the air, for microbial control and / or sterilization / improvement. To release into the environment.

  In certain embodiments, the method comprises (a) hydration (in the form of water in solution or water molecules bound by covalent valence, van der Waals forces, or London dispersion forces), ozone, plasma Under conditions to produce purified hydrogen peroxide gas (PHPG) that is substantially free of species and / or organic species, a catalyst comprising a metal or metal oxide is exposed to ultraviolet light in the presence of moist and clean ambient air. Exposing the PHPG to the environment so that the hydrogen peroxide gas acts in the environment, and more preferably on the surface and in the air both for microbial control and / or sterilization / improvement. To release into.

  Another aspect of the invention is, for example, hydration (in the form of water in water or water molecules bound by covalent valence, van der Waals forces, or London dispersion forces), ozone, plasma species, and / or Or relates to a diffuser device for producing PHPG substantially free of organic species. The diffuser device generally includes (a) an ultraviolet light source, (b) a catalyst substrate structure made of a metal oxide, and (c) an air distribution mechanism.

  Another aspect of the invention relates to a method for controlling the production of PHPG. In some embodiments, the yield of PHPG is achieved by balancing the feed air between fresh air without any PHPG and recirculating air with a desired level of PHPG, and combinations thereof. In order to improve the generation, the generation of PHPG is controlled by wavelength selection in the photocatalytic device.

  Another aspect of the present invention relates to the oxidation / removal of volatile organic hydrocarbons (VOC) in ambient air with PHPG released to the environment.

  Another aspect of the present invention relates to the removal of ozone from ambient air by PHPG released to the environment.

  These and other aspects of the invention will be apparent to those of ordinary skill in the art upon reading the present disclosure.

It is sectional drawing about one Embodiment of the diffuser apparatus which concerns on this invention. It is the figure which cut off one part of one Embodiment of the diffuser apparatus which concerns on this invention. It is sectional drawing about one Embodiment of a 360 degree pedestal installation type diffuser apparatus. 1 is a cross-sectional view of one embodiment of a wing-shaped diffuser device intended for use, for example, in a building air duct. FIG. It is sectional drawing about one Embodiment of the diffuser apparatus integrated in the fluorescent lamp fixture of a ceiling, for example. It is sectional drawing about one Embodiment of a humidification type diffuser apparatus. It is sectional drawing about one Embodiment of a diffuser apparatus containing a humidity sensor. FIG. 2 is a cross-sectional view of one embodiment of a diffuser device for use in, for example, a small area. FIG. 2 is a cross-sectional view of an embodiment equipped with a diffuser device for use in, for example, aircraft, ground vehicles, and mass transit air supply systems. It is a figure which shows the front surface of suitable one Embodiment of the said diffuser apparatus based on this invention. It is the figure which cut off a part of suitable one Embodiment of the said diffuser apparatus based on this invention. It is a figure which shows the side surface of suitable one Embodiment of the said diffuser apparatus based on this invention.

  The present invention relates generally to microbial control and / or sterilization / improvement methods and related devices. In some embodiments, photocatalytic treatment may be used in the methods and apparatus.

  The basic property of photocatalytic treatment is to produce an active intermediate product by absorption of light in a chemical reaction. This occurs when a photon with the appropriate wavelength hits the photocatalyst. Photon energy is applied to electrons in the valence band, which are excited to the conduction band, leaving a “hole” in the valence band. In the absence of adsorbed species, the excited electrons decay and recombine with holes in the valence band. Recombination is prevented when electrons are trapped from species that can oxidize holes in the valence band-preferentially water molecules adsorbed on the active surface sites of the photocatalyst. At the same time, the reducible species adsorbed on the surface of the photocatalyst—preferentially oxygen molecules—may trap the electrons in the conduction band.

The following reaction takes place at the start of the photocatalytic treatment or at the entry point of the photocatalytic plasma reactor.
Oxidation
Two-photon _{+ 2H 2 O → 2OH * +} 2H + + 2e -
2OH * → H ₂ O ₂
reduction
^{_{O 2 + 2H + + 2e -}} → H 2 O 2
However, once hydrogen peroxide is generated, the photocatalyst reduces hydrogen peroxide (reduction potential 0.71 eV) preferentially instead of oxygen molecules (reduction potential −0.13 eV), and the reaction is performed by a plasma reactor. To the following equilibrium, which takes place in most volumes.
Oxidation
Two-photon _{+ 2H 2 O → 2OH * +} 2H + + 2e -
2OH * → H ₂ O ₂
reduction
^{_{H 2 O 2 + 2H + +}} 2e - → 2H 2 O

In the context of the present invention, purified hydrogen peroxide gas (PHPG) is a form designed for the purpose of removing hydrogen peroxide from the PHPG reactor before it is forced to undergo subsequent reduction by a photocatalyst. May be produced using a photocatalytic treatment with If the adsorbed hydrogen peroxide gas cannot be used, the photocatalyst is forced to reduce oxygen preferentially rather than hydrogen peroxide. Then, hydrogen peroxide gas may generally be generated simultaneously by both water oxidation and dioxygen reduction in the photocatalytic treatment. While not intending to be limiting, in a processing operation, the amount of hydrogen peroxide produced is doubled and most of it is removed from the system before it can be reduced. As a result, the amount of PHPG produced is thousands of times the amount of unpurified hydrogen peroxide produced accidentally produced from an equal number of active catalyst sites under the same conditions in the photocatalytic plasma reactor. . In addition, the form designed for this purpose enables the generation of PHPG at a humidity sufficiently lower than the absolute humidity at which the photocatalytic plasma reactor can operate effectively. For example, production of PHPG greater than 0.2 ppm has been achieved at 2.5 milligrams absolute humidity per liter. The dominant reaction in a form designed for this purpose is as follows.
Oxidation
Two-photon _{+ 2H 2 O → 2OH * +} 2H + + 2e -
2OH * → H ₂ O ₂
reduction
^{_{O 2 + 2H + + 2e -}} → H 2 O 2
However, without being limited by theory, the microbial control and / or sterilization / improving method and apparatus of the present invention is achieved by the action of PHPG released into the environment, not as a result of photocatalytic treatment. It should be noted.

  Using a form that allows the hydrogen peroxide gas to be removed immediately before it can be reduced, PHPG may be produced by any suitable process known in the prior art. This treatment includes, but is not intended to be limited to, a treatment that oxidizes water to a gas state and simultaneously reduces oxygen gas, for example, doped with titanium dioxide, zirconia, a catalyst (such as copper, rhodium, silver, platinum, gold). Gas phase photocatalytic method using a catalyst made of a metal such as titanium dioxide or a photocatalyst made of other suitable metal oxide. PHPG may be produced by electrolysis using any suitable metal or cathode and anode consisting of a metal oxide ceramic with a structure that allows hydrogen peroxide gas to be removed immediately before it can be reduced. Alternatively, PHPG is produced by exciting gaseous water and oxygen molecules at high frequency on a suitable support substrate using a structure that can be removed immediately before hydrogen peroxide gas can be reduced. Also good.

  In one aspect of the present invention, a method for microbial control and / or sterilization / improvement of the environment is disclosed. This method involves (a) eg hydration (in the form of water in solution or water molecules bound by covalent valence, van der Waals forces, or London dispersion forces), ozone, plasma species, and / or presence. To produce purified hydrogen peroxide gas (PHPG), which is substantially free of equipment, and (b) to perform microbial control and / or sterilization / improvement in the environment, more preferably both on the surface and in the air In other words, the PHPG gas is released into the environment so that the PHPG acts on the environment.

  As used herein, the term “purified hydrogen peroxide gas” or PHPG is bound by at least hydration (water in solution, or covalent valence, van der Waals force, or London dispersion force). It usually means a gaseous form of hydrogen peroxide that is substantially free of water molecules and substantially free of ozone.

  In some embodiments, the method comprises (a) eg hydration (in the form of water in solution or water molecules bound by covalent valence, van der Waals forces, or London dispersion forces), ozone, plasma UV light in the presence of moist and clean ambient air under conditions to produce purified hydrogen peroxide gas (PHPG) that is substantially free of species and / or organic species And (b) bringing the PHPG into the environment so that the PHPG acts in the environment, more preferably both on the surface and in the air, for microbial control and / or sterilization / improvement. To release and remove ozone and VOC from the ambient air.

  In one embodiment, the ultraviolet light is about 181 nm or more, about 185 nm or more, about 187 nm or more, about 182 nm to about 254 nm, about 187 nm to about 250 nm, about 188 nm to about 249 nm, about 255 nm to about 380 nm, etc. Generate a wavelength in at least one of the ranges. In some embodiments, wavelengths in the range of about 255 nm to about 380 nm are preferred to improve the yield of PHPG.

  Another aspect of the present invention is, for example, hydration (the form of water in solution or water molecules bound by covalent valence, van der Waals forces, or London dispersion forces), ozone, plasma species, and The present invention relates to a diffuser device for generating a gas composed of purified hydrogen peroxide gas (PHPG) substantially free of organic species. For example, referring to FIGS. 1 and 2, the diffuser apparatus generally includes (a) an ultraviolet light source 4, (b) a metal or metal oxide catalyst substrate structure 3, and (c) air distribution mechanisms 5, 6 and / or 7. And.

  In some embodiments, the air distribution mechanism may be a fan 5 or other mechanism suitable for moving a fluid, such as air, through a diffuser device. According to certain aspects of the present invention, the selection, design, sizing, and operation of the air distribution mechanism should be such that the fluid flowing through the diffuser device, such as air, is generally the fastest in practice. . Without intending to be bound by theory, it is believed that optimal PHPG levels are being generated to exit the diffuser device under rapid fluid flow conditions.

  The ultraviolet light source 4 typically emits light in at least one wavelength range sufficient to cause a photocatalytic reaction in moist ambient air, but does not photodegrade oxygen to initiate ozone production. In one embodiment, the ultraviolet light is at least about 181 nm or more, about 185 nm or more, about 187 nm or more, about 182 nm to about 254 nm, about 187 nm to about 250 nm, about 188 nm to about 249 nm, about 255 nm to about 380 nm, etc. Generate a range of wavelengths. In some embodiments, wavelengths in the range of about 255 nm to about 380 nm are preferred to improve the yield of PHPG comprising non-hydrated hydrogen peroxide that is substantially free of ozone.

  In the present invention, the expression “substantially free of ozone” generally means an amount of ozone that is approximately 0.015 ppm or less and has dropped to a level that is less than or equal to the ozone level of detection (LOD). Such a level is below the general tolerance for human health. In this connection, the US Food and Drug Administration (FDA) has set indoor medical devices to emit less than 0.05 ppm of ozone. The US Occupational Safety and Health Administration (OSHA) states that workers should not be exposed to ozone with an average concentration of 0.10 ppm or higher for 8 hours. The National Institute for Occupational Safety and Health (NIOSH) recommends that the ozone limit of 0.1 ppm should not always be exceeded. The US Environmental Protection Agency (EPA) environmental air quality standards set a maximum outdoor concentration of 0.08 ppm for ozone and a maximum of 8 hours. The diffuser device described in this document has always demonstrated that it does not produce a level of ozone detectable by the drager tube.

However, in some embodiments, PHPG may be used to remove ozone from the surrounding environment by the following reaction:
O ₃ + H ₂ O ₂ → H ₂ O + 2O ₂

  In some embodiments, PHPG may be used to remove VOCs from the surrounding environment by direct oxidation of VOCs by PHPG.

  In some embodiments, PHPG is used for microbial control including, but not limited to, bactericides for indoor air treatment, mold and / or fungal removal devices, bacteria removal devices, and / or virus removal devices. Also good. The PHPG method may produce a sufficient amount of hydrogen peroxide gas to perform the desired microbial control and / or sterilization / remediation process. Sufficient amounts are usually known to those skilled in the art and can vary depending on the particular sterilization / remediation nature, depending on the solid, liquid, or gas to be purified.

  In certain embodiments, with respect to microbial control and / or sterilization / improvement of air and related environments (including surfaces therein), the amount of PHPG is from about 0.005 ppm to about 0.10 ppm in the environment to be sterilized, particularly It varies from about 0.02ppm to about 0.05ppm. Such amounts include, for example, feline calicivirus (EPA is recognized as an alternative to norovirus), methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococcus facaris (VRE), Clostridium difficile (C-Diff), It has been proven effective against Geobacillus stearothermophilus and Aspergillus niger. Such amounts of PHPG can be used safely in human areas (including but not limited to schools, hospitals, offices, homes, other common areas), sterilizing microorganisms that contaminate the surface, Provide microbial control, such as sterilizing airborne pathogens, preventing the spread of influenza pandemics, controlling nosocomial infections, and reducing the transmission of common diseases.

  In certain embodiments, with respect to microbial control and / or sterilization / improvement of air and associated environments (including surfaces therein), the amount of PHPG varies from approximately 0.005 ppm to approximately 0.40 ppm in the environment to be sterilized. . A 0.2 ppm PHPG level using a feed of untreated air with an absolute humidity of 3.5 mg / L can always be achieved. In particular, PHPG levels from about 0.09 ppm to about 0.13 ppm using moist recirculated air can be produced in the environment to be sterilized. Such an amount has proved effective against eg H1N1 virus. Also, this amount of PHPG can be used safely in areas where people (including but not limited to schools, hospitals, offices, homes, other common areas) and sterilizes microorganisms that contaminate the surface. And sterilizing pathogens in the air, preventing the spread of influenza pandemics, controlling nosocomial infections, and reducing the transmission of common diseases.

  In one aspect of the present invention, the humidity of the ambient air is preferably about 1% or higher relative humidity (RH), about 5% or higher RH, about 10% or higher RH, and the like. In some embodiments, the ambient air humidity may be from approximately 10% RH to approximately 99% RH. In some embodiments, the method of the present invention adjusts the humidity of the ambient air within a range of approximately 5% RH to approximately 99% RH, or approximately 10% RH to approximately 99% RH. Contains.

  The catalyst comprising a metal or metal oxide is selected from titanium dioxide, copper, copper oxide, zinc, zinc oxide, iron, iron oxide, or a mixture thereof, more preferably titanium dioxide. In particular, titanium dioxide is a semiconductor that absorbs light in the near ultraviolet part of the electromagnetic spectrum. Titanium dioxide is synthesized in two forms, anatase and rutile, both of which are actually different faces of the same parent crystal structure. The shape to be formed depends on the preparation method and the starting material used. Anatase absorbs photons with a wavelength of 380 nm or less, whereas rutile absorbs photons with a wavelength of 405 nm or less.

The titanium dioxide layer about 4 μm thick absorbs 100% of incident short wavelength light. Titanium dioxide is known to have about 9-14 × 10 ¹⁴ active surface sites per square centimeter. Active surface sites are coordinately unsaturated sites on the surface and can bind to hydroxyl ions or other basic species. The photocatalytic activity of titanium dioxide is affected by its structure (anatase or rutile), surface area, dimensions, porosity, and density of hydroxyl groups on the surface. Anatase is generally considered to be a more active photocatalyst than rutile. Anatase is known to adsorb dioxygen more strongly than rutile and maintains photoconductivity longer than rutile after flash emission. Anatase and rutile have band gap energies of 3.2 eV (electron volts) and 3.0 eV, respectively.

  Many chemicals have been identified that affect photocatalysis. Such chemicals may be added to the reaction environment to affect photocatalytic processing. As recognized by those skilled in the art, certain chemicals facilitate processing and other chemicals reduce processing. In addition, other chemical substances act to promote certain reactions and suppress other reactions.

  From acid-base chemistry it is known that basic substances bind to the active sites of the catalyst. Without being limited by theory, a reducing substance that adsorbs more strongly than dioxygen on the catalyst may be substituted for the electron acceptor. Small molecule chemicals, metals, and ions all have this ability. In such cases, the effect on the production of PHPG is determined by the electron accepting efficiency of the chemical for dioxygen and hydrogen peroxide.

  Some additional chemicals contain radical species in side reactions or in the production of more inert radicals that cannot perform the desired reaction. Other chemicals also physically change the photocatalyst and change its ability. In accordance with the present invention, additional chemicals may be chosen to optimize the production of PHPG (and additionally minimize or eliminate the production of ozone, plasma species, or organic species).

  In one embodiment, as described above, the additional chemical may include a cocatalyst. The cocatalyst may be a metal or coating deposited on the surface of the catalyst to improve the efficiency of the selected PHPG reaction. Cocatalysts may change the physical properties of the catalyst in two ways. First, the cocatalyst may provide a new energy level occupied by electrons in the conduction band. Second, the cocatalyst may have different adsorption characteristics than the photocatalyst carrying the cocatalyst. This makes the order of reactions occurring on the cocatalyst differ from the order of reactions occurring on the catalyst. Cocatalysts are generally most effective at surface coverage of 5% or less. Typical cocatalysts may be selected from platinum, silver, nickel, palladium, and many other metal compounds. Phthalocyanine also has a proven cocatalytic ability.

  The diffuser device according to the present invention may have any suitable shape and dimensions including spherical, hemispherical, cubic, cuboid and the like. Instead of a non-limiting example, the diffuser device is a sailboat-shaped, 360 ° -mounted, wing-shaped (e.g. for air ducts in buildings), e.g. a design that may be incorporated into a ceiling fluorescent light fixture, It may be configured as a clearly configured design for use in a small area (e.g., for use in aircraft, ground vehicles, and mass transit air supply systems). Further, the diffuser device may have any fantasy shape such as a teddy bear, a pig money box, or a mock radio.

  The core of the diffuser device may be composed of an ultraviolet light source. The ultraviolet light source 4 located in the center or inside of the diffuser device may have various intensities depending on the size of the device and the intended application.

  For example, in one embodiment shown in FIGS. 1 and 2, the diffuser device may be generally wedge-shaped. For example, the tubular ultraviolet light source 4 may be accommodated in an elongated wedge-shaped or tubular diffuser shell 2. In some structures, the reflector 1 may serve to focus light in a specific direction within the device as required by the specific shape of the device.

  The diffuser device shell 2 may be formed from any suitable substrate material including ceramic, porcelain, polymer, and the like. For example, the polymer is a hydrophobic porous or breathable polymer that is not degraded by ultraviolet light having a wavelength of 380 nm to 182 nm. Polymers that are resistant to light of a certain wavelength, but not all within the above range, are used with an ultraviolet lamp that emits only light of a wavelength in the resistant range. The diffuser shell may be molded to any desired size and shape and any desired color. In some embodiments, the shell material may incorporate a phosphorescent material that absorbs ultraviolet light and emits visible light.

  In general, the diffuser device includes a fluid distribution mechanism. In general, the fluid distribution mechanism serves to move fluid, such as air, through the diffuser device. In particular, the air distribution mechanism pumps fluid into the diffuser device, which then diffuses through the diffuser substrate.

  In one embodiment, with reference to FIG. 2, the fluid distribution mechanism directs fluid through the vent inlet 7 to a small fan (not shown) that is fitted into the opening 5 of the diffuser device. The fan also includes a replaceable hydrophobic gas and / or dust filter 6 on the upstream side to prevent organic gas and / or dust from entering the diffuser device, ensuring that the PHPG is substantially free of organic species. I keep it. In some embodiments, if necessary, the fluid distribution mechanism is the minimum power required to provide a gentle overpressure in the diffuser, and in other embodiments, a fast fan speed is more preferred.

  In another embodiment shown in FIG. 3, a cross-sectional view of an embodiment in which a 360 ° pedestal is attached is shown in the diffuser device. This is a modification of the diffuser device similar to the diffuser device of FIGS. 1 and 2, which can be arranged at the center of a wide area, for example.

  In another embodiment shown in FIG. 4, a cross-sectional view of one embodiment of a wing-shaped diffuser device intended for use, for example, in a building air duct is shown. As can be seen, the device is configured to provide a flow of air that flows to an orthogonal vent surface at the leading edge of the device and is adapted to force air into the device. A light emitting diode mass and a photocatalytic sail are placed parallel to the trailing edge of the wing shape to reduce the low air pressure generated by the trailing edge of the wing shape to draw the PHPG from the device when the PHPG is generated. I use it well. In some embodiments, the diffuser device of FIG. 4 turns off the device when there is no auxiliary internal fan (not shown) to generate more airflow and air flowing through the air duct. An air flow sensor (not shown) may be additionally provided for resuming the device when both resume, or both.

  In addition, in another embodiment shown in FIG. 5, a cross-sectional view of an embodiment of a diffuser device that can be incorporated into a ceiling fluorescent lamp fixture is illustrated. As can be seen, the fluorescent lamp bulb of the original instrument has been removed, and the instrument is provided with a hermetic seal and wiring to turn on the fan. Thereafter, a fluorescent lamp bulb suitable for the generation of PHPG is installed, and the bottom of the instrument incorporates an assembly that includes an intake fan and a filter, such as a rectangular photocatalytic sail, and a rectangular vent diffuser, for example.

  Further, in another embodiment shown in FIG. 6, a cross-sectional view of one embodiment of a humidifying diffuser device is illustrated. As can be seen from the figure, the core is disposed downstream of the filter with its lower portion immersed in a water tray. The tray can be supplied manually or by automatic water supply adjusted by a water level sensor (not shown).

  Further, in another embodiment shown in FIG. 7, a cross-sectional view of an embodiment of a diffuser device including a humidity sensor is shown. In one embodiment, the humidity sensor is used to turn off the device if an operating humidity is detected that exceeds, for example, predetermined operating parameters (eg, 95%, 98%, 99%, etc.). May be.

  Also, in another embodiment shown in FIG. 8, a cross-sectional view of one embodiment for a diffuser device for a small area is shown. This small device is designed to plug directly into the power output of a small room. The intake fan and the filter at the end of the device supply air to a small photocatalyst sail activated by small light emitting diodes lined up to generate PHPG.

  In addition, in another embodiment shown in FIG. 9, a cross-sectional view is illustrated for an embodiment in which a diffuser device for use in, for example, an aircraft, a ground vehicle, and a mass transport air supply system is mounted. . The mounted device may be placed directly in the flow of supply air, or an internal fan may be provided to offset the pressure drop that occurs when air passes through the device. In certain embodiments, the apparatus may be configured to have an outer cross section that is the same size as the inner cross section of the airflow duct for each particular application of the embodiment.

  Also, in another embodiment shown in FIG. 10, a front view of a preferred embodiment of the diffuser device is shown. This device is symmetrical in all dimensions, length, width and height, and is installed in a pedestal shaped bottom sleeve to stand upright as shown, or mounted horizontally from a wall or ceiling by a bracket. sell.

  In another embodiment shown in FIG. 11, a cross-sectional view of a preferred embodiment of the diffuser device is shown. This device employs arc-shaped dust and VOC filters to improve the filtering action and to supply filtered air to the inlet plenum. The arc-shaped filter distributes the air flow more evenly through a larger surface area while suppressing pressure loss due to the passage of the filter. The intake plenum supplies a row of three fans that send out air so as to be orthogonal to an arc-shaped photocatalyst sail arranged just inside the ventilation outlet. In this embodiment, air flows directly from the rear of the device to the front. The two ultraviolet light bulbs are offset out of the air flow to illuminate the photocatalytic sail evenly. This embodiment provides better performance: 7.66 times filtration performance, 7.5 times airflow, and 2 times photon flux. This supplies moist air to the photocatalytic sail at a greatly improved rate (increases the production of PHPG) and ensures that more PHPG remains to leave the system, once produced photocatalytic surface The residence time of the upper PHPG is greatly reduced.

  FIG. 12 shows a side view of the embodiment of the diffuser device of FIG.

  In one embodiment, the inner surface of the diffuser shell may be generally used as a substrate by being coated with a photocatalyst comprising titanium dioxide doped with one or more metals in some embodiments. For example, the photocatalyst may be applied as a paint to the inner surface of the diffuser substrate. This application is generally performed so as not to block the pores in the diffuser substrate. In one embodiment, air may be supplied to the diffuser substrate and forced through the pores of the substrate after photocatalyst application to dry the paint and force the pores to penetrate through the forced air. A combination of a photocatalytic coating and a diffuser substrate that is sufficiently opaque so that UV light does not leak from the assembled diffuser device is preferred.

  In other embodiments, the diffuser shell and the catalyst substrate are separate components with the substrate layer positioned very close to the inside of the inner surface of the diffuser shell.

  In some embodiments, the diffuser device may be designed to operate at a predetermined range of wavelengths to improve especially the yield of PHPG, as described herein. . Further, in some embodiments, the diffuser device may be humidified (see FIG. 6) and may be designed to operate at a specific operating humidity, with operating parameters adjusted accordingly. Also good. In this regard, the diffuser device may include a humidity sensor (see FIG. 7). In some embodiments, the diffuser apparatus may additionally include a control system that optimizes the PHPG yield based on the humidity of the operating environment and / or shuts down if humidity conditions are undesirable. Good.

  The diffuser design is orthogonal to the air flow rather than downsizing the diffuser to a volume optimized configuration designed to maximize residence time in the plasma reactor. The production of PHPG is optimized by thinning the surface of the air permeable photocatalytic PHPG reactor over a large area (eg, on a sail-like area in some embodiments). By constructing the above PHPG reaction form as a thin, sail-like air-permeable structure just inside the inner shell of the diffuser, the length of the outlet passage of hydrogen peroxide molecules generated on the catalyst gradually increases. The residence time in the PHPG reactor structure is reduced only momentarily, preventing most of the hydrogen peroxide molecules from subsequently adsorbing on the catalyst and being reduced to water. In addition, by placing the catalyst substrate just inside the inner surface of the diffuser shell, not only the surface area of the PHPG reactor is maximized, but also the generated PHPG immediately escapes from the diffuser and is exposed to an ultraviolet light source for a long time. The photolysis of PHPG by is avoided. The concentration of PHPG produced by this form reached a high concentration of 0.4 ppm.

  In a preferred embodiment, the concentration of PHPG may be self-adjusted by electrostatic attraction between PHPG molecules that decompose into water and oxygen upon reaction with each other. PHPG self-regulation occurs whenever the concentration of PHPG reaches a concentration such that the distance between PHPG molecules approaches each other within the electrostatic attraction of PHPG molecules. When this self-regulation occurs, the PHPG molecules are attracted to each other and decompose until the concentration is sufficiently reduced to extend the distance between the PHPG molecules and out of the electrostatic attractive force of the PHPG molecules. Thereby, the concentration of PHPG is maintained at a level sufficiently lower than 1.0 ppm, which is the OSHA workplace safety limit.

In some embodiments, active control of the PHPG power level is desirable and PHPG production can be coordinated by the PHPG reactor itself. The PHPG production level can be set to any level from 0.01 ppm to 0.40 ppm by recirculating slightly conditioned treated air containing PHPG returning through the PHPG reactor. When this setting is made, the PHPG output level is controlled by the following series of reactions.
Oxidation
Two-photon _{+ 2H 2 O → 2OH * +} 2H + + 2e -
2OH * → H ₂ O ₂
reduction
(100% - x%) O 2 + 2 (100% - x%) H + + 2 (100% - x%) e - → (100% - x%) H 2 O 2
_{x% H 2 O 2 + 2x} % H + + 2x% e - → 2x% H 2 O

  The reduction potential of PHPG peroxide bonds (+0.71 eV) is much higher than the reduction potential of double bonds between oxygen atoms in oxygen molecules (-0.13 eV), so PHPG is preferential over oxygen. Only a small amount of recycled PHPG is required to reduce the net production level. Due to this regulated slight recirculation, a PHPG reactor that is otherwise designed for the highest output will simply return it through the PHPG reactor, and some of the air that has already been processed. By changing the direction of air, it can be set to a lower level.

  It should also be noted that this PHPG optimized form minimizes the residence time of any organic contaminants entering and through the system, dramatically reducing the likelihood of organic contaminants being oxidized. The photocatalyst system optimized for the generation of PHPG is designed to effectively oxidize organic pollutants when passing through the catalyst structure, and the photocatalyst system optimized to oxidize organic pollutants is designed Prevents the production of hydrogen peroxide gas.

  In one aspect of the present invention, PHPG is produced by the oxidation of adsorbed water molecules by a photocatalyst in the absence of ozone, plasma species, and organic species, for example, when activated with ultraviolet light in the stated range. May be. In one embodiment, a diffuser substrate coated with a photocatalyst on the inside (or a diffuser shell covered with a thin sail-like breathable photocatalytic structure on the inside) may be placed on and around the ultraviolet light lamp. The opening in the diffuser may serve as a frame into which the ultraviolet light source and the structural support are fitted. When assembled, the diffuser device may operate as follows. That is, (a) the fluid distribution mechanism sends air through the organic vapor and dust filter into the diffuser to create overpressure, and (b) the air passes through the pores or vents in the substrate and / or diffuser shell. (C) Moisture contained in the air is adsorbed on the surface of the photocatalyst, and (d) UV light generated by the lamp is activated by irradiating the photocatalyst. (E) The PHPG generated in the diffuser device exits the diffuser through the diffuser pores or vents and rapidly moves to the surrounding environment. To do.

  In some embodiments, PHPG is generated by a medium pressure mercury arc (MPMA) lamp. An MPMA lamp emits not only ultraviolet light but also visible light having a wavelength in the infrared region. When choosing a lamp, it is important to examine the UV output in detail. The spectral output in the ultraviolet region is represented by a graph and may show output proportional to the important ultraviolet wavelength. The broad spectrum of MPMA lamps is chosen because of its functionality.

  In other embodiments, PHPG is emitted by an ultraviolet light emitting diode (UV LED). UV LEDs are smaller and groups of UV LEDs are lined up in various sizes and methods, allowing for smaller and more robust products.

  In other embodiments, the output of the PHPG may be adjusted by a control system that manages the devices singly or in groups. Such a control system consists of (a) turning the device on and off, (b) adjusting light intensity and fan speed, and (c) automatic colorimetric analyzer, automatic dregger indicator, PHPG accumulated in water traps. Measures heat released by exothermic flash evaporation, measurement of change in conductivity of substrate to detect hydrogen peroxide accumulation, or exothermic reaction between PHPG and a stable reactant to which PHPG is attracted by electrostatic attraction The operation may be adjusted by directly monitoring the environmental PHPG level by thermal means, and (d) indirectly monitoring the environmental PHPG level by relative humidity.

Although not intended to limit the invention to the following examples, in one embodiment of the invention, (a) the device is a quarter cylinder with a length of 50.8 cm and a radius of 21.6 cm; The 1/4 cylinder is designed to fit the 90 ° angle where the wall meets the ceiling, the straight sides of the 1/4 cylinder are in close contact with the ceiling and the wall, and the 1/4 cylindrical curved surface is Facing the chamber outward and downward, (c) the right end, seen from the bottom of the 1/4 cylinder, is a hydrophobic high-efficiency air intake consisting of a variable speed fan and activated carbon with a maximum output of 6.79 m ^{3 /} min (D) The left end of the 1/4 cylinder is located at the center of the power connector for the fan and 1/4 cylinder, and the medium-pressure mercury arc (35.6 cm) extends in the longitudinal direction of the 1/4 cylinder ( MPMA) lamp is housed, and (e) a metal reflector with a vent that reflects light toward the inside of the curved surface of the 1/4 cylinder is the back of the MPMA lamp. Arranged later, (f) the curved surface of the 1/4 cylinder has a structure in which air flows outside the apparatus but does not leak light.

  The curved sail-like photocatalyst structure is placed parallel to the inside of the curved surface of the 1/4 cylinder. (A) The photocatalyst substrate is placed in a frame of 45.7 cm in length and 27.9 cm in height, from the top to the bottom. (B) consisted of glass fibers coated with crystalline titanium dioxide powder, and (c) titanium dioxide was applied in five layers so as to completely cover the entire surface of the glass fibers Thereafter, the photocatalyst crystals are sintered in a furnace to bond them to each other and to the glass fibers.

  During operation, the fan and the MPMA lamp are turned on. (A) The intake air is sucked into the device through a hydrophobic high-efficiency inlet filter made of activated carbon, and the inlet filter removes moisture from the intake air. Without adsorbing and removing volatile organic hydrocarbons (VOC), (b) Intake air is sent to the back of the device, and the photocatalytic structure and the curved surface of the quarter cylinder by a metal reflector with a vent (C) Moisture and oxygen in the intake air are adsorbed onto the photocatalyst activated with light from the wavelength 255 nm to 380 nm from the MPMA lamp, and (d) activated. The photocatalyst oxidizes water to hydroxyl radicals, which combine to form hydrogen peroxide, while dioxygen is simultaneously reduced on the photocatalyst to hydrogen peroxide, and (e) Hydrogen oxide gas ( HPG) is carried away immediately by the flow of air away from the photocatalyst, light passes through the ventilation surface of the device impervious, is released into the room.

  The PHPG thus produced is (a) produced by catalytic means rather than by evaporation of the aqueous solution, so there is virtually no bound water, and (b) light of a wavelength that allows the MPMA lamp to photolyze dioxygen. Since PHPG is substantially free of ozone and (c) the structure of the photocatalyst allows hydrogen peroxide to rapidly desorb from the surface of the photocatalyst before it is subsequently reduced with the photocatalyst, There is virtually no plasma species, and (d) as soon as PHPG leaves the surface of the photocatalyst, it escapes from the device through the non-light-transmitting and air-permeable surface of the 1/4 cylinder. (E) Since VOC is adsorbed by a hydrophobic high efficiency inlet filter made of activated carbon, PHPG was essentially free of organic species.

  The device of the present invention was subjected to the following tests designed and conducted by two accredited laboratories. (A) measure the output of PHPG, (b) confirm that the product (PHPG) is substantially free of ozone, (c) confirm that the product is substantially free of VOC, ) Feline calicivirus (recognized by the US Environmental Protection Agency as a norovirus substitute), methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococcus facaris (VRE), Clostridium difficile (C-Diff), Geobacillus stearothermophilus (Stable bacteria used by the insurance industry to demonstrate whether or not the improvement to microorganisms was successful), measured the effectiveness of PHPG against Aspergillus niger, (e) 70-72 degrees Fahrenheit, 35% -40% relative humidity %, 81 to 85 degrees Fahrenheit, 56% to 59% relative humidity, 78 degrees Fahrenheit, and 98% relative humidity.

Measurements of ozone, VOC, temperature, and humidity were all performed using standard equipment. Since a device for measuring hydrogen peroxide gas at a level of 0.10 ppm or less is not yet readily available, three new means have been devised. That is, (a) hydrogen peroxide test strips commonly used for measuring approximate concentrations in aqueous solutions were found to detect the presence of PHPG after time, and (b) usually read after 20 seconds of exposure. It was found that the hydrogen peroxide test specimens designed in 1 were able to read the approximate concentration of PHPG with an accuracy of 0.01 ppm when accumulated with PHPG and normalized with an exposure time of less than 1 hour. For example, a specimen that has accumulated 0.5 ppm of PHPG over 5 minutes is exposed for 15 × 20 seconds, exhibits an approximate concentration of 0.5 ppm / 15 or 0.033 ppm, and (c) 0.10 after aspiration of 2000 cm ³ of air. Drager tubes (indicators) designed to detect low concentrations of hydrogen peroxide in ppm can read low PHPG concentrations with an accuracy of 0.005 ppm when a large amount of air is inhaled by a calibrated pump. I understood. For example, Dre jar tube showing the 0.10ppm concentration after aspiration of 4000 cm ³ is a PHPG concentration approximately 0.05ppm was measured, Dre jar tube showing the 0.10ppm concentration after aspiration of 6000 cm ³ is measured PHPG concentration substantially 0.033ppm (D) The measurements using the hydrogen peroxide test piece and the drager tube were found to be in good agreement with each other.

In a test that measured the level of hydrogen peroxide at varying humidity, the following data was obtained:

  The PHPG measurement data indicates that the concentration of generated PHPG is highly dependent on relative humidity. This can be predicted because the production of PHPG is directly dependent on the water molecules available in the air. It should be noted that the US Department of Health and Human Services requires that the relative humidity of the hospital operating room be maintained between 30% and 60%.

  Further, the PHPG measurement data is kept constant for a long time, and shows an equilibrium upper limit value of approximately 0.08 ppm. This can also be predicted from the electrostatic attractive force between the PHPG molecules that always works when the distance between the PHPG molecules falls within the electrostatic attractive force range between the molecules. Under this condition, excess PHPG reacts itself to oxygen molecules and water molecules. The upper limit of 0.08 ppm is lower than the US Occupational Safety and Health Administration's workplace safety limit of 1.0 ppm, so you can breathe safely, so that the PHPG system can be used safely and sustainably in the human area. Show.

  All tests also show that the gas released from the device is completely free of ozone.

In the VOC test, the approximate concentration of 2-propanol in a 70.8 m ³ room was set to 7 ppm. The device has been found to rapidly reduce indoor VOC levels.

  In qualitative testing of microorganisms, chips inoculated with Geobacillus Stearothermophilus were placed in several test environments, and in all cases there was a significant reduction in bacteria within a few hours.

Quantitative testing of microorganisms at the ATS (American Thoracic Society) Laboratory in Eagan, Minnesota yielded the following data: It should be noted that remarkable sterilization rates were achieved with a PHPG concentration of only 0.005 ppm to 0.01 ppm produced at 35% to 40% relative humidity.

  Higher humidity produces a higher concentration of PHPG and increases the rate of microbial reduction. Data was collected since this test using the improved prototype achieved a PHPG concentration as high as 0.40 ppm, 40 times higher than that used for this quantitative test.

  Also, the comparative test shows that the PHPG test apparatus is thousands of times the equilibrium of unpurified hydrogen peroxide, which was generated accidentally from an equal number of active catalyst sites under the same conditions in a photocatalytic plasma reactor. It was shown to produce a concentration of PHPG.

  Although the present invention has been described in terms of particular embodiments with some degree of particularity, this specification is merely an example and provides details of construction, manufacture, and use, including combinations and arrangements of members. It should be understood that many variations are possible within the spirit and scope of the invention as shown in the illustrated embodiments.

Claims (17)

(A) water in solution, or water, ozone, plasma species, and / or organic species bound in the form of water molecules bound by covalent valence, van der Waals forces, or London dispersion forces Producing no purified hydrogen peroxide gas (PHPG);
(B) releasing the PHPG into the environment so that the hydrogen peroxide gas acts to control and / or sterilize / improve microorganisms both on the surface and in the air in the environment. A method for microbial control and / or sterilization / improvement of a characteristic environment. The method of claim 1, wherein
The generated PHPG is electrostatically attracted to positively and negatively charged structures and / or sites on the microorganism, so that when compared to either hydrated hydrogen peroxide or ozone, the microorganism A method characterized by improving the effectiveness of the PHPG in control and / or sterilization / improvement. The method of claim 1, wherein
The method wherein the supplied PHPG is at a concentration between 0.005 ppm and 0.40 ppm. The method of claim 1, wherein
The supplied PHPG can be actively adjusted to the desired concentration by balancing the supply air between the untreated air and the slightly circulating air already treated with the PHPG. Feature method. The method of claim 1, wherein
Said microbial control and / or sterilization / improvement of the environment comprising indoor air treatment, water purifier, mold remover, bacteria remover, and virus remover. The method of claim 1, wherein
The method according to claim 1, wherein the relative humidity of the air is within a range of 5 to 99% or adjusted within the range. (A) water in solution, or water, ozone, plasma species, and / or organic species bound in the form of water molecules bound by covalent valence, van der Waals forces, or London dispersion forces Exposing the catalyst comprising a metal or metal oxide to ultraviolet light in the presence of moist, clean ambient air under conditions to produce no purified hydrogen peroxide gas (PHPG);
(B) In the environment, the PHPG is discharged into the environment so that the hydrogen peroxide gas acts to control and / or sterilize / improve microorganisms on the surface and in the air. To control and / or sterilize / improve the environment. The method of claim 7, wherein
Said microbial control and / or sterilization / improvement of the environment comprising indoor air treatment, water purifier, mold remover, bacteria remover, and virus remover. The method of claim 7, wherein
The method according to claim 1, wherein the relative humidity of the air is within a range of 5 to 99% or adjusted within the range. The method of claim 7, wherein
The catalyst comprising the metal or metal oxide is titanium dioxide. The method of claim 7, wherein
The PHPG product also removes both ozone and VOC from the ambient air by direct chemical reaction of ozone and VOC species with PHPG, this removal (a) produces oxygen and water. Reacting with ozone for the purpose, and (b) reacting with VOC to produce carbon dioxide and water. The method of claim 7, wherein
The catalyst comprising the metal or metal oxide is exposed to ultraviolet light having a wavelength in the range of at least about 255 nm to about 380 nm.   A diffuser device for generating PHPH, comprising: (a) an ultraviolet light source; (b) a metal or metal oxide catalyst substrate structure; and (c) an air distribution mechanism. The apparatus of claim 13.
The form of the catalyst on the catalyst substrate is a thin, sail-like air-permeable structure, and is arranged to be orthogonal to the air flow through the diffuser device,
The form changes the reaction equilibrium of the catalyst to produce hydrogen peroxide from both oxidation of water and reduction of oxygen, and the form is suitable for the peroxidation before the hydrogen peroxide can be reduced. An apparatus characterized by substantially preventing hydrogen peroxide reduction on the catalyst by flowing hydrogen away from the catalyst and rapidly away from the catalyst. The apparatus of claim 13.
The air distribution mechanism is a fan. The apparatus of claim 13.
The ultraviolet light source generates at least one range of wavelengths. The apparatus of claim 13.
The ultraviolet light source generates a wavelength in a range of more than one.

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