Patent Description:
Embodiments of the disclosure relate to an air management system used to provide air to one or more compartments within a vehicle, and more specifically, to a system for sterilizing a portion of the air management system and the air therein.

Pressurized aircraft have integrated air management systems to provide a pressurized environment, fresh air transfer, recycling, heating, and air conditioning to maintain a comfortable safe environment for occupants for extended periods. Air recycling and replacing stale air requires continuous scrubbing for cleanliness to minimize airborne dust, dirt, odors, viruses, spores, and bacteria. This cleaning or scrubbing of the air is typically performed via physical, electrostatic or chemical filtration, such as via a HEPA filter. However, bacteria and dirt can accumulate on the filter, requiring cleaning or replacement of the filters themselves. <CIT> according to its abstract describes a method for air conditioning of an aircraft including the steps of obtaining a fresh air for ventilation; exhausting an air from a cabin; obtaining a purified air for recirculation from a part of the air exhausted; obtaining an air for ventilation; supplying the air for ventilation to the cabin; and irradiating an ultraviolet ray emitted from a UV-LED to the purified air for recirculation. <CIT> describes an air purification system for operating theaters.

An air management system of a vehicle, wherein the vehicle is an aircraft, is defined in claim <NUM>.

With reference now to <FIG>, a schematic of an example of an air management system <NUM> to control the air of a vehicle, such as an aircraft <NUM> is illustrated. The aircraft <NUM> includes a pressurized area or cabin <NUM> that the air management system <NUM> controls. The cabin <NUM> may be configured to house people, cargo, and the like therein. The air management system <NUM> provides conditioned air to, and removes used or contaminated air from, the cabin <NUM>. The air management system <NUM> includes an environmental control system <NUM> having at least one air conditioning unit or pack <NUM>, and a cabin air recirculation sub-system <NUM>. While the air management system <NUM> is illustrated and described herein with reference to an aircraft <NUM>, it should be understood that, not according to the claims, the systems and techniques discussed herein may be used for a variety of air management systems <NUM>. For example, the cabin <NUM> may be replaced with any closed volume to be conditioned. As such, systems described herein may be used with ship air management systems, such as submarines and cruise liners for example, personnel carrier air management systems, bus, trolley, train, or subway air management systems, or any other air management system that requires a continual supply of conditioned air.

As shown in the <FIG>, air is provided from one or more sources <NUM> to the air management system <NUM>. Examples of suitable sources <NUM> include but are not limited to an engine of the aircraft <NUM> and an auxiliary power unit of the aircraft <NUM>. The medium output from these sources <NUM> is provided to the one or more air conditioning units <NUM> of the environmental control system <NUM>. Within these air conditioning units <NUM>, the medium is conditioned. This conditioning includes altering one or more of a pressure, temperature, humidity, or flow rate of the medium based on an operating condition of the aircraft. The medium output or discharged from the one or more air conditioning units <NUM> of the environmental control system <NUM> may be used maintain a target range of pressures, temperatures, and/or humidity within the cabin <NUM>.

The medium discharged from the air conditioning units <NUM> is provided to an air mixing unit or mixing manifold <NUM> via one or more outlet ducts <NUM>. Similarly, at least one duct <NUM> of the cabin air recirculation sub-system <NUM> extends from the cabin <NUM> to the air mixing unit <NUM> to deliver air exhausted from the cabin <NUM> to the air mixing unit <NUM>. Within the air mixing unit <NUM>, the cabin recirculating air is mixed with the medium output from the one or more air conditioning units <NUM> to achieve a mixed medium having one or more desired parameters, such as temperature, pressure, and humidity for example.

In an embodiment, the mixed medium is delivered to the cabin <NUM> from the air mixing unit <NUM> via an air distribution system <NUM> including one or more conduits <NUM>. As shown, the mixed medium may be delivered to the cabin <NUM> and cockpit via a ventilation system arranged near a ceiling of the cabin <NUM>. In some embodiments, the mixed medium typically circulates from the top of the cabin <NUM> toward the floor, and is distributed to a plurality of individual vents <NUM> of the ventilation system spaced laterally between the front and rear of the cabin <NUM>. It should be understood that the air management system <NUM> illustrated and described herein is intended as an example only, and that any suitable air management system is within the scope of the disclosure.

With reference now to <FIG>, an example of a portion of the cabin air recirculation sub-system within the air management system <NUM> is shown in more detail. In the illustrated, non-limiting embodiment, a portion of the duct <NUM> of the cabin air recirculation sub-system <NUM> and fluidly connects one or more outlets <NUM> (see <FIG>) of the cabin <NUM> to the air mixing unit <NUM>. Mounted within the duct is a filter <NUM> configured to remove bacteria, viruses and particulate matter from the cabin recirculation air provided from the outlets <NUM> in the cabin <NUM> as it flows through the filter <NUM>. Although the filter <NUM> is shown as being arranged adjacent a downstream end of the duct, such as directly upstream from an interface between the duct and the air mixing unit, a filter arranged at any location within the duct is contemplated herein. Further, although the filter <NUM> is illustrated as having a circular configuration in <FIG>, and a rectangular configuration in <FIG>, it should be understood that a filter <NUM> having any configuration is within the scope of the disclosure. In an embodiment, the filter <NUM> is a HEPA-type filter. However, any suitable filter, or combination of multiple filters is within the scope of the disclosure. Further, in an embodiment, the duct <NUM> includes a recirculation fan <NUM> to establish an overpressure that is used to drive the flow of the recirculating cabin air through the filter <NUM> and to the air mixing unit <NUM>. However, embodiments of a portion of a cabin air recirculation sub-system <NUM> that do not include a fan such that air flow through the duct <NUM> is driven by another source or by pressure for example, are also contemplated herein.

With reference now to <FIG>, in an embodiment, the air management system <NUM> additionally includes a sterilization system <NUM> for sterilizing at least a portion of the air therein. In addition to the removal of particulate matter, the sterilization described herein additionally includes killing or rendering harmless bacteria or airborne viruses within the air management system <NUM> and/or an air flow there through. Because dehumidified air is easier to sterilize, the air is dehumidified before passing through (upstream from) he sterilization system <NUM> and is then rehumidified downstream of the sterilization system <NUM>, such as in the air mixing unit <NUM> for example.

As shown, in an embodiment, the sterilization system <NUM> is used to sterilize a portion of the air provided to the cabin <NUM>, such as the cabin recirculation air discharged from outlets <NUM> of the cabin <NUM> and provided to the air mixing unit <NUM> and/or a portion of one or more ducts <NUM> extending between the cabin outlets <NUM> and the air mixing unit <NUM>. Further, it should be understood that although a duct <NUM> of the cabin air recirculation system <NUM> is illustrated and described herein with respect to the sterilization system <NUM>, any portion of the air management system <NUM>, and specifically any portion or duct that is used to move cabin discharge air or cabin recirculation air through the air management system <NUM>, including but not limited to the air mixing unit <NUM> and the conduits <NUM> of the air distribution system <NUM> for example, may be adapted for use with a sterilization system <NUM> as described herein.

The sterilization system <NUM> includes at least one light source <NUM> capable of emitting a light having a wavelength suitable to perform germicidal irradiation. In an embodiment, the light source <NUM> is operable to emit a germicidal ultraviolet light, such as having a wavelength between about <NUM> and about <NUM> nanometers, also known as "UV-C. " The wavelength of the light emitted by the light source <NUM> may further be between about <NUM> and about <NUM>, or about <NUM> and about <NUM>, about <NUM> to about <NUM>, or more specifically <NUM> to <NUM>.

It should be understood that ultraviolet light having another wavelength, such as between <NUM> and <NUM>, and more specifically between <NUM> and <NUM>, or other types of light may also be suitable for use in sterilization applications. Additionally, a light source <NUM> having any configuration, such as an individual bulb, a light strip having a plurality of bulbs or light emitting diodes, or another type of emitter, is within the scope of the disclosure. In embodiments of the sterilization system <NUM> including a multiple light sources <NUM>, a configuration of the light sources may be substantially identical, or alternatively, may vary based on a position of the light source <NUM> relative to the air management system.

The use of germicidal ultraviolet light, and specifically UV-C light, typically requires exposure for only a matter of seconds to kill any virus or bacteria present. However, the length of exposure may vary in response to one or more parameters, such as the wavelength of the light, the intensity or strength of the light, the volume flow rate of air, and the humidity of the air, for example. In an embodiment, the one or more light sources <NUM> and an intensity of each light source <NUM> is determined based on at least one of the volume flow rate and the humidity of the air. Because exposure for only a limited period of time is required for sterilization, the one or more light sources <NUM> may be disposed at one or more areas along the flow path defined by the duct <NUM>.

In an embodiment, the one or more light sources <NUM> are located at an area of the flow path where the flow of air provided from the cabin outlets <NUM> is slowest. For example, the flow rate of the cabin recirculation air through the portion of the duct <NUM> including the filter <NUM> is reduced relative to the flow rate of the air at an upstream portion of the duct <NUM> to maximize the efficacy of the filter <NUM>. Accordingly, in an embodiment, one or more light sources <NUM> are mounted such that the light emitted therefrom projects over substantially the entire surface <NUM> of the filter <NUM>. As a result, any viruses or bacteria present on the filter <NUM>, such as trapped in the filter material itself, are killed or neutralized. In such embodiments, the one or more light sources <NUM> may be integrated into the filter <NUM> (<FIG>) and/or may be mounted to a portion of the duct <NUM>, such as directly adjacent the filter <NUM> (<FIG>), or alternatively, at a location axially offset from the filter <NUM> (<FIG>) such that the light emitted from the light sources <NUM> overlaps the surface the filter <NUM>.

In other embodiments, the sterilization system <NUM> may additionally include one or more light sources <NUM> arranged at a location where the flow rate of the cabin circulation air is faster than at the filter <NUM>. As shown, one or more light sources <NUM> may be arranged within the air management system <NUM> to emit germicidal ultraviolet light over a portion of the flow path defined by the duct <NUM>, upstream from the filter <NUM>, as shown in <FIG> and <FIG>. Although the figures show a sterilization system <NUM> including a plurality of light sources <NUM> operable to illuminate substantially the entire length of the duct <NUM> extending between an upstream end thereof <NUM> and the filter <NUM>, embodiments where only a portion of the duct <NUM> is illuminated are also contemplated herein. In some embodiments including multiple light sources <NUM>, each of the plurality of light sources <NUM> may be positioned such that the light emitted therefrom overlaps with the light emitted from an adjacent light source <NUM>. As shown, the light sources may be mounted within the same plane, such as adjacent the same side of the duct <NUM>, or alternatively, at different sides of the duct <NUM>, such as opposite sides (<FIG>) or adjacent sides (<FIG>) for example. As a result, the region of the duct <NUM> illuminated by the light sources <NUM> will be free from shadows or non-illuminated areas where bacteria or viruses may accumulate.

Further yet, one or more interior surfaces <NUM> of the duct <NUM> within the region illuminated by the one or more light sources <NUM> may have a reflective or mirrored coating to facilitate increased distribution of the germicidal light throughout the duct <NUM>. A reflective or mirrored coating as described herein may include, but is not limited to, one or more of aluminum, gold, chrome, nickel, titanium, copper, silver, copper oxide, titanium dioxide, zinc oxide, or another suitable shiny material or polished surface. Further, such a coating may be applied via any suitable method, such as via a spray, dip, wipe, vapor deposition, plating, or other known method. In an embodiment, the coating material is applied via vapor deposition, such as via atomic layer deposition for example. Application of a coating material via atomic layer deposition permits non-line-of-sight coating because a molecular layer of various germicidal chemical compounds may be formed anywhere the vapor makes contact.

By mounting one or more light sources <NUM> capable of emitting a germicidal ultraviolet light along the flow path of the cabin recirculation air, the light sources <NUM> may be used to continuously disinfect the airflow and/or a portion of a duct <NUM>, without exposing aircraft occupants to any harmful effects from exposure to a high intensity ultra-violet light. Further, the sterilization system could continuously operate when the vehicle is both airborne and grounded without the need for any chemical means of rendering airborne viruses and bacteria harmless. Additionally, the one or more ultra-violet light sources <NUM> are small, use minimal power, and do not require high power, heat, or chemicals to kill viruses and bacteria.

Claim 1:
An air management system (<NUM>) of a vehicle, said vehicle being an aircraft comprising a cabin, the air management system comprising:
an air source;
an environmental control system (<NUM>) in fluid communication with the air source;
a cabin air recirculation system (<NUM>) configured to be fluidly connected to at least one outlet of the cabin;
an air mixing unit (<NUM>) fluidly connected to the environmental control system and to the cabin recirculation system;
an air distribution system (<NUM>) extending from the air mixing unit and configured to extend to one or more vents associated with the cabin;
at least one duct (<NUM>) defining a flow path for delivering air to the cabin
and extending between the at least one outlet of the cabin and the air mixing unit (<NUM>);
and
a sterilization system (<NUM>) associated with the at least one duct, the sterilization system including at least one light source operable to emit a germicidal ultraviolet light into the flow path defined by the at least one duct to sterilize the air to be provided to the cabin, said sterilization system (<NUM>) further including a filter, wherein the at least one light source is operable to emit said germicidal ultraviolet light and characterized in that the at least one light source is positioned such that the emitted light projects over substantially all of the surface of the filter, and wherein the filter is mounted within the at least one duct;
and further characterized in that the air is dehumidified upstream from the sterilization system, and further wherein the air is rehumidified downstream of the sterilization system.