WO2024031198A1

WO2024031198A1 - Methods and systems for using ultraviolet light-emitting diodes for air disinfection

Info

Publication number: WO2024031198A1
Application number: PCT/CA2023/051075
Authority: WO
Inventors: Babak Adeli Koudehi; Ehsan ESPID; Shahriar Rouhani ANARAKI; Majid KESHAVARZFATHY; Milad Raeiszadeh OSKOUEI
Original assignee: Acuva Technologies Inc.
Priority date: 2022-08-12
Filing date: 2023-08-11
Publication date: 2024-02-15

Abstract

A fluid (e.g. air) disinfection apparatus. The fluid disinfection apparatus may be a flow-through fluid (e.g. air) disinfection apparatus for disinfecting fluid (e.g. air) that flows through the apparatus. An ultraviolet light emitting diode (UV-LED) may be supported within a housing of the optical head to emit radiation to thereby irradiate the air. In some embodiments, a reactor body is attached to the optical head and the UV-LED directs radiation into a conduit defined by the reactor body to thereby disinfect air within the reactor body.

Description

METHODS AND SYSTEMS FOR USING ULTRAVIOLET LIGHT-EMITTING DIODES FOR AIR DISINFECTION

Related Applications

[0001] This application claims priority from US application No. 63/397,387 filed on 12 August 2022. For the purposes of the United States, this application claims the benefit under 35 USC 119 in relation to US application No. 63/397,387 filed on 12 August 2022 which is hereby incorporated herein by reference.

Field

[0002] This application is directed to fluid disinfection devices, and in particular to flow-through disinfection devices comprising one or more ultraviolet (UV) radiation emitters configured to disinfect air.

Background

[0003] There is a general desire to disinfect fluids using UV radiation. Various products exist for disinfecting water with UV radiation.

[0004] Another particular fluid for which is disinfection is desirable is air. Air has a number of properties that are different than water. There is a general desire to use ultraviolet light emitting diodes (UV-LEDs) to disinfect air in a manner which takes advantage of some of the properties of air which may be different than those of water.

[0005] The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.

Summary

[0006] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the abovedescribed problems have been reduced or eliminated, while other embodiments are directed to other improvements.

[0007] One aspect of the invention provides an apparatus for treating air with ultraviolet radiation comprising an optical head. The optical head may comprise a housing defining an inlet through which the air can enter the optical head in a first direction and an outlet through which the air can exit the optical head and an ultraviolet light emitting diode (UV-LED) supported within the housing to emit radiation to thereby irradiate the air.

[0008] In some embodiments, at least some of the air is routed to pass around the UV-LED as the air passes through the housing to thereby assist in cooling the UV- LED. In some embodiments, at least some of the air is routed to come into thermal contact with the UV-LED as the air passes through the housing to thereby assist in cooling the UV-LED.

[0009] In some embodiments, the UV-LED is supported within the housing by a backing and the backing defines one or more backing apertures wherein at least some of the air is routed to pass through the one or more backing apertures into thermal contact with the UV-LED as the air passes through the housing to thereby assist in cooling the UV-LED. In some embodiments, wherein the backing comprises a circuit board with components for directing current to the UV-LED.

[0010] In some embodiments, the optical head defines a first path for a portion of the air to travel from the inlet to the outlet, the first path travelling through the one or more backing apertures and into thermal contact with the UV-LED and a second path for another portion of the air to travel around the backing.

[0011] In some embodiments, the optical head comprises a lens assembly for shaping the radiation emitted by the UV-LED and wherein the lens assembly is supported by a scaffold within the housing. In some embodiments, the scaffold defines one or more scaffold apertures such that at least some of the air is routed to pass through the scaffold apertures after the air passes the UV-LED.

[0012] In some embodiments, the lens assembly comprises one or more lenses configured such that 50% of the power of the radiation output from the one or more lenses is within a solid angle of 10 degrees from a principal radiation direction of the UV-LED. In some embodiments, the lens assembly comprises one or more lenses configured such that 50% of the power of the radiation output from the one or more lenses is within a solid angle of 8 degrees from a principal radiation direction of the UV-LED. In some embodiments, the lens assembly comprises one or more lenses configured such that 60% of the power of the radiation output from the one or more lenses is within a solid angle of 10 degrees from a principal radiation direction of the UV-LED. In some embodiments, the lens assembly comprises one or more lenses configured such that 60% of the power of the radiation output from the one or more lenses is within a solid angle of 8 degrees from a principal radiation direction of the UV-LED. In some embodiments, the lens assembly comprises one or more lenses configured such that 70% of the power of the radiation output from the one or more lenses is within a solid angle of 10 degrees from a principal radiation direction of the UV-LED. In some embodiments, the lens assembly comprises one or more lenses configured such that 70% of the power of the radiation output from the one or more lenses is within a solid angle of 8 degrees from a principal radiation direction of the UV-LED.

[0013] In some embodiments, the optical head comprises a heat sink in thermal contact with the backing. In some embodiments, the optical head comprises a heat sink in thermal contact with the UV-LED. In some embodiments, at least some of the air is routed into contact with the heat sink as the air passes through the housing, thereby cooling the heat sink. In some embodiments, the heat sink defines one or more heat sink apertures and at least some of the air is routed through the one or more heat sink apertures as the air passes through the housing.

[0014] In some embodiments, the optical head comprises a diffuser to distribute air, the diffuser located between the UV-LED and the outlet. In some embodiments, the diffuser promotes a uniform distribution of air as it exits through the outlet of the optical head. In some embodiments, the diffuser promotes a distribution of air wherein a velocity of the air is higher near a cross-sectional center of the optical head as the air exits through the outlet of the optical head. In some embodiments, the diffuser promotes a distribution of air velocity as the air exits through the outlet of the optical head wherein the distribution of air velocity of at least a portion of the air is substantially correlated with a distribution of radiation intensity that is emitted from the UV-LED. In some embodiments, the diffuser promotes a distribution of air velocity as the air exits through the outlet of the optical head wherein the distribution of air velocity of at least a portion of the air is substantially correlated with a distribution of radiation intensity that is refracted by a lens assembly.

[0015] In some embodiments, the diffuser defines one or more diffuser apertures. In some embodiments, the one or more diffuser apertures open in a second direction, non-parallel to the first direction. In some embodiments, the one or more diffuser apertures open in a second direction, orthogonal to the first direction. In some embodiments, the diffuser substantially blocks the air from reaching the outlet unless the air passes through the one or more diffuser apertures.

[0016] In some embodiments, the apparatus for treating air comprises a reactor body in fluid connection with the outlet such that the air flows out the outlet and into a conduit defined by the reactor body and wherein the UV-LED irradiates the air inside the conduit. In some embodiments, a longitudinally extending inner surface of the conduit has a lower degree of specular reflectivity than a surface of an end wall of the conduit, the end wall located opposite to the outlet of the optical head. In some embodiments, a longitudinally extending inner surface of the conduit has a higher degree of diffuse reflectivity than a surface of an end wall of the conduit, the end wall located opposite to the outlet of the optical head. In some embodiments, the longitudinally extending inner surface of the conduit comprises polytetrafluoroethylene (PTFE). In some embodiments, the surface of the end wall comprises aluminum. In some embodiments, a longitudinally extending inner surface of the conduit comprises a photocatalyst material. In some embodiments, a longitudinally extending inner surface of the conduit comprises a semi-conductive photocatalyst material. In some embodiments, the semi-conductive photocatalyst material comprises TiOa.

[0017] In some embodiments, the apparatus for treating air comprises a second optical head in fluid communication with an outlet of the reactor body and configured to direct second radiation into the conduit of the reactor body, wherein the second optical head comprises substantially the same features and components as other optical heads described herein.

[0018] In some embodiments, the conduit comprises a plurality of conduit segments in fluid communication with one another.

[0019] In some embodiments, the apparatus for treating air comprises at least one additional optical head located in each conduit segment wherein each of the at least one additional optical heads comprises substantially the same features and components as other optical heads described herein. In some embodiments, the at least one additional optical head comprises a plurality of additional optical heads and the plurality of additional optical heads comprises a pair of optical heads opposite one another in a first conduit segment of the plurality of conduit segments.

[0020] In some embodiments, the apparatus for treating air comprises one or more reflective surfaces to reflect radiation emitted by the UV-LED into a first conduit segment of the plurality of conduit segments from the first conduit segment into a second conduit segment of the plurality of conduit segments.

[0021] In some embodiments, the apparatus for treating air comprises a housing containing the optical head and a second optical head wherein the housing comprises a housing inlet to direct the air into the inlet and the second inlet and a housing outlet through which the air can exit the housing and the second optical head comprises the features and components of as other optical heads described herein. In some embodiments, the apparatus for treating air comprises a reactor body connected to the housing outlet wherein the UV-LED and the second UV-LED irradiate the air inside the reactor body.

[0022] In some embodiments, the inlet opens in the first direction and the outlet opens in a third direction, the third direction non-parallel to the first direction. In some embodiments, the inlet opens in the first direction and the outlet opens in a third direction, the third direction orthogonal to the first direction.

[0023] In some embodiments, the UV-LED is supported to emit radiation with a principal axis of emission aligned in a first direction. In some embodiments, the UV- LED is supported to emit radiation with a principal axis of emission aligned in a fourth direction, the fourth direction non-parallel to the first direction. In some embodiments, the UV-LED is supported to emit radiation with a principal axis of emission aligned in a fourth direction, the fourth direction orthogonal to the first direction. In some embodiments, the UV-LED is supported to emit radiation with a principal axis of emission aligned in a fourth direction, the fourth direction non-parallel to a direction of flow of air through the optical head. In some embodiments, the UV-LED is supported to emit radiation with a principal axis of emission aligned in a fourth direction, the fourth direction orthogonal to a direction of flow of air through the optical head. [0024] In some embodiments, the optical head comprises a fan for drawing the air in through the inlet and pushing the air out through the outlet.

[0025] In some embodiments, the apparatus for filtering air comprises an air filter located upstream of the optical head such that the air passes through the filter before passing through the optical head. In some embodiments, the optical head comprises an air filter.

[0026] In some embodiments, the optical head comprises a second ultraviolet light emitting diode (UV-LED) supported within the housing to emit the radiation to thereby irradiate the air. In some embodiments, the optical head comprises a plurality of ultraviolet light emitting diodes (UV-LEDs) supported within the housing to emit the radiation to thereby irradiate the air.

[0027] Another aspect of the invention provides a method for treating air. In some embodiments, the method comprises flowing air through an apparatus for treating air as described herein and causing the UV-LED to emit radiation to thereby disinfect the air. In some embodiments, the method comprises installing the apparatus for treating air in an air duct of an HVAC system.

[0028] Other aspects of the invention provide apparatus comprising any new and inventive feature, combination of features, or sub-combination of features described herein.

[0029] Other aspects of the invention provide methods comprising any new and inventive feature, combination of features or sub-combination of features described herein.

[0030] It is emphasized that the invention relates to all combinations of the above features, even if these are recited in different claims.

[0031] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following detailed descriptions.

Brief Description of the Drawings

[0032] Exemplary embodiments are illustrated in referenced figures of the drawings.

It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.

[0033] Figures 1 A to 1 D (collectively, Figure 1 ) depict a flow-through air disinfection apparatus according to an embodiment of the invention. Figure 1 A is a perspective view thereof. Figure 1 B is a cross-sectional view thereof. Figure 1 C is a partial cutaway perspective view thereof. Figure 1 D is an exploded view thereof.

[0034] Figures 2A to 2D (collectively, Figure 2) depict a flow-through air disinfection apparatus according to another embodiment of the invention. Figure 2A is a perspective view thereof. Figure 2B is a cross-sectional view thereof. Figure 2C is a partial cut-away perspective view thereof. Figure 2D is an exploded view thereof.

[0035] Figure 3 is a schematic cross-sectional illustration of a flow-through air disinfection apparatus according to another embodiment of the invention.

[0036] Figure 4 is a schematic cross-sectional illustration of a flow-through air disinfection apparatus according to another embodiment of the invention.

[0037] Figure 5 is a schematic cross-sectional illustration of a flow-through air disinfection apparatus according to another embodiment of the invention.

[0038] Figure 6 is a schematic cross-sectional illustration of a flow-through air disinfection apparatus according to another embodiment of the invention.

[0039] Figure 7 is a schematic cross-sectional illustration of a flow-through air disinfection apparatus according to another embodiment of the invention.

[0040] Figure 8 is a schematic cross-sectional illustration of a flow-through air disinfection apparatus according to another embodiment of the invention.

[0041] Figure 9 is a schematic cross-sectional illustration of a flow-through air disinfection apparatus according to another embodiment of the invention.

[0042] Figure 10 is a schematic cross-sectional illustration of a flow-through fluid (e.g. air) disinfection apparatus according to an embodiment of the invention.

Detailed Description

[0043] Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive sense.

[0044] One aspect of the invention provides a fluid (e.g. air) disinfection apparatus. The fluid disinfection apparatus may be a flow-through fluid (e.g. air) disinfection apparatus for disinfecting fluid (e.g. air) that flows through the apparatus. The fluid may comprise air. The apparatus may comprise an optical head. The optical head may comprise a housing or be located within a housing defining an inlet through which the air can enter the optical head in a first direction and an outlet through which the air can exit the optical head. An ultraviolet light emitting diode (UV-LED) may be supported within the housing to emit radiation to thereby irradiate the air. In some embodiments, a reactor body is attached to the optical head and the UV-LED directs radiation into a conduit defined by the reactor body to thereby disinfect air within the reactor body. In some embodiments, the apparatus may be a standalone apparatus (e.g. it may include a fan for drawing air in through the inlet and pushing air out through the outlet). In other embodiments, the apparatus may be attachable to a heating, ventilation and/or air condition (HVAC) system (e.g. by replacing a section of ducting with the apparatus or by installing the apparatus at one end of the ducting) either at the time of installing the HVAC system or by retrofitting it to the HVAC system.

[0045] Figure 1 (collectively Figures 1 A to 1 D) depicts an exemplary flow-through fluid (e.g. air) disinfection apparatus 10 (also referred to herein as apparatus 10 or disinfection apparatus 10) according to an embodiment of the invention. Apparatus 10 may comprise a flow-through air disinfection apparatus 10. Apparatus 10 comprises an optical head 16. In some embodiments, disinfection apparatus 10 comprises a reactor body 18 in fluid communication with optical head 16. In some embodiments, reactor body 18 is integrally formed with optical head 16 but this is not mandatory. Instead, reactor body 18 may be attached to optical head 16 using suitable techniques (e.g. adhesive, press fit, interference fit, etc.) or connectors (e.g. fasteners, etc.).

[0046] Air flows into apparatus 10 via inlet 12 in direction 36. Air may flow out of apparatus 10 via outlet 14 in direction 36 (or another direction non-parallel or orthogonal to direction 36). More precisely, air flows into an inlet 16A of optical head 16 and out of an outlet 16B of optical head 16. In some embodiments, air then flows into an inlet 18A of reactor body 18 and out of an outlet 18B of reactor body 18. Inlet 12 of apparatus 10 may comprise inlet 16A of optical head 16. Outlet 14 of apparatus 10 may comprise outlet 18B of reactor body 18.

[0047] As explained in more detail herein, air may be disinfected as it travels through at least a portion of apparatus 10 (e.g. between inlet 16A and outlet 16B and/or between inlet 18A and outlet 18B) and, as such, apparatus 10 may be referred to as a flow-through disinfection apparatus 10. Inlet 12 may be operatively connected to a source of air (e.g. an input air conduit) and outlet 14 may be operatively connected to (or located within) a suitable conduit for conducting air away from apparatus 10.

[0048] Optical head 16 comprises one or more UV-LEDs 20. For example, in the illustrated embodiment, optical head 16 comprises a plurality of UV-LEDs 20. UV- LEDs 20 may be mounted on a backing 22 to support UV-LEDs 20 within a housing 16C of optical head 16. Backing 22 may also support suitable electronic components (e.g. drive circuits, control circuits and/or the like) which may cause UV-LEDs 20 to emit UV radiation having radiation parameters suitable for disinfecting air as the air passes through apparatus 10. In some embodiments, backing 22 comprises one or more circuit boards (e.g. printed circuit boards (PCBAs)).

[0049] Backing 22 may define one or more apertures 22A. Apertures 22A may allow air to flow through backing 22. Air flowing through apertures 22A of backing 22 may be directed or routed to flow around one or more of UV-LEDs 20 thereby assisting in cooling UV-LEDs 20. For example, air flowing through apertures 22A may be routed or directed into thermal contact with UV-LEDs 20 (e.g. such that the air may assist in cooling of UV-LEDs 20). In contrast to liquid UV purification devices where the liquid could damage UV lights if the liquid came into contact with the PCBA and/or UV LEDs, air is unlikely to damage the PCBA or the UV-LEDs and may therefore assist in cooling UV-LEDs 20. Apertures 22A may have any suitable size, shape and/or locations on backing 22. In some embodiments, apertures 22A are sized, shaped, and/or located on backing 22 to direct air at or toward UV-LEDs 20 to increase the cooling effect of the air on UV-LEDs 20.

[0050] Optical head 16 may comprise one or more lens assemblies 24 for shaping radiation emitted by UV-LEDs 20. In the illustrated embodiment, optical head 16 comprises a lens assembly 24 for each UV-LED 20. This is not mandatory, a single lens assembly 24 may be provided for multiple UV-LEDS 20. Lens assemblies 24 may each comprise one or more lenses for shaping radiation emitted from their corresponding UV-LEDs 20. In the illustrated embodiments, lens assemblies 24 each comprise one or more lenses configured to (a) collimate radiation from their corresponding UV-LED 20; and (b) direct the collimated radiation out of outlet 16B (and into conduit 19 of reactor body 18).

[0051] In some embodiments, lens assemblies 24 each comprise one or more lenses configured such that 50% of the power of the radiation output or refracted by the one or more lenses is within a solid angle of 10 degrees from a principal radiation direction of the UV-LED. In some embodiments, lens assemblies 24 each comprise one or more lenses configured such that 50% of the power of the radiation output or refracted by the one or more lenses is within a solid angle of 8 degrees from a principal radiation direction of the UV-LED. In some embodiments, lens assemblies 24 each comprise one or more lenses configured such that 60% of the power of the radiation output or refracted by the one or more lenses is within a solid angle of 10 degrees from a principal radiation direction of the UV-LED. In some embodiments, lens assemblies 24 each comprise one or more lenses configured such that 60% of the power of the radiation output or refracted by the one or more lenses is within a solid angle of 8 degrees from a principal radiation direction of the UV-LED. In some embodiments, lens assemblies 24 each comprise one or more lenses configured such that 70% of the power of the radiation output or refracted by the one or more lenses is within a solid angle of 10 degrees from a principal radiation direction of the UV-LED. In some embodiments, lens assemblies 24 each comprise one or more lenses configured such that 70% of the power of the radiation output or refracted by the one or more lenses is within a solid angle of 8 degrees from a principal radiation direction of the UV-LED.

[0052] Lens assemblies 24 may be housed in and/or supported by a lens-supporting scaffold 26 within housing 16C of optical head 16. Scaffold 26 may be permeable to air flowing through apparatus 10. For example, scaffold 26 may define one or more apertures 26A through which air can flow. Unlike water, air flowing through scaffold 26 will not have a deleterious impact on the performance of UV-LEDs 20 or lens assemblies 24. By allowing air to flow in the space between UV-LEDs 20 and lens assemblies 24, air can be disinfected in optical head 16 (e.g. in addition or alternative to being disinfected within reactor body 18). Further, as discussed elsewhere herein, air may have a cooling effect as it passes around and/or into thermal contact with UV- LEDs 20.

[0053] Optical head 16 may comprise a heat sink 30. Heat sink 30 may comprise any suitable type of heat sink. Heat sink 30 may comprise a passive heat sink or an active heat sink. Heat sink 30 may be in thermal contact with backing 22 and/or UV-LEDs 20 for conducting heat away from backing 22 (and corresponding electronics supported thereon) and/or UV-LEDs 20. Air may travel around and/or through heat sink 30 as it travels through apparatus 10 to help carry heat away from heat sink 30. Like scaffold 26 and unlike heat sinks connected to PCBAs and UV-LEDs in water treatment apparatus, heat sink 30 may be permeable to air flowing through apparatus 10 to permit contact between air and backing 22 and/or to allow air to directly contact UV- LEDs 20 to increase the ability of optical head 16, backing 22 and UV-LEDs 20 to stay cool. For example, in some embodiments, heat sink 30 comprises one or more apertures or channels 30A to allow air to flow through heat sink 30 toward backing 22 where air may flow through apertures 22A.

[0054] By allowing air to flow through backing 22 and scaffold 26, a greater volume of air may be able to flow through optical head 16, thereby increasing the throughput of apparatus without increasing the size of optical head 16.

[0055] Optical head 16 may comprise a diffuser 32. Diffuser 32 may be located between inlet 16A and outlet 16B of optical head 16 or between outlet 16B of optical head 16 and inlet 18A of reactor body 18. Diffuser 32 may be shaped to define one or more diffusing apertures 34. In some embodiments, some (e.g. a majority) of the air flowing through optical head 16 to reactor body 18 will pass through diffusing apertures 34. The configuration of diffusing apertures 34 may promote mixing and/or uniform distribution of air as it travels through reactor body 18. In some embodiments, apertures 34 open in the same direction as inlet 16A of optical head 16 (e.g. both apertures 35 and inlet 16A open in direction 36). In some embodiments, apertures 34 open in a direction that is non-parallel to the direction in which inlet 16A opens. In some embodiments, apertures 34 open in a direction that is orthogonal to the direction in which inlet 16A opens, as shown in Figure 1.

[0056] In some embodiments, diffuser 32 is shaped and/or located to create an air velocity distribution within the apparatus (e.g. within reactor body 18) that correlates with a radiation intensity distribution of radiation emitted by UV-LED 20 (and refracted by lens assembly 24). By correlating the air velocity distribution to the radiation intensity distribution, the efficiency and efficacy of apparatus 10 may be increased as

(a) less radiation will be wasted on areas of low flow velocity within apparatus 10; and

(b) more radiation will be provided to areas of high velocity within apparatus 10 thereby ensuring sufficient disinfection of air in the high velocity areas.

[0057] Optical head 16 may comprise an air filter (not shown). The air filter may comprise any suitable type of air filter. The air filter may be provided to catch particulate matter. In some embodiments, the air filter is provide upstream of one or more of heat sink 30, backing 22, UV-LEDs 20 and lens assemblies 24 (e.g. in order to protect such components from particles that would be caught and trapped by the air filter). In some embodiments, the air filter comprises, for example, any air filter having a minimum efficiency reporting value of 8 or higher.

[0058] In practice, air flows out of outlet 16B from optical head 16 and through inlet 18A into a conduit 19 defined by reactor body 18. Air may be irradiated within conduit 19 of reactor body 18 by radiation from UV-LEDs 20 that is refracted (e.g. collimated or at least partially collimated) by lens assemblies 24.

[0059] Reactor body 18 (and conduit 19) may be elongated in a longitudinal direction 36. Reactor body 18 and/or conduit 19 may have a length L in longitudinal direction 36 and a maximum internal cross-sectional dimension D in a direction and cross- sectional plane orthogonal to longitudinal direction 36. In the illustrated embodiment, reactor body 18 is shaped such that conduit 19 has a generally circular cross-section, but this is not necessary and conduit 19 may have any desired shape in cross-section (e.g. polygonal, ellipsoidal, semi-circular and/or the like).

[0060] When compared to devices for irradiating water, apparatus 10 may have a longitudinal dimension L that is relatively long (e.g. 50cm or longer in some embodiments, 100cm or longer in some embodiments or 200cm or longer in some embodiments), because the attenuation of UV radiation in air is significantly less than the attenuation of UV radiation in water (e.g. transmittance of UV in water is about 95%/cm (e.g. a 5% loss in intensity per cm), whereas transmittance of UV is air is greater than 99%/cm). Advantageously, when compared to devices for irradiating water, apparatus 10 may have an aspect ration L/D that is relatively large, because the attenuation of UV radiation in air is significantly less than the attenuation of UV radiation in water.

[0061] An inner surface 19C of conduit 19 may be coated in a reflective material. In some embodiments, an inner surface 19C of reactor body is coated in a material exhibiting a high degree of diffuse reflectivity such as, for example, polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE) .

[0062] An inner surface 19C of conduit 19 may be coated in a photocatalyst material. The photo-catalyst material may comprise a semi-conductive photocatalyst material. The semi-conductive photocatalyst material may comprise titanium dioxide (TiOa).

[0063] In some embodiments, outlet 18B of reactor body 18 is open. In some embodiments, an endwall or end cap 38 is provided at outlet 19C of reactor body 18. End cap 38 may at least partially block outlet 19C thereby forcing air exiting through outlet 18B to exit via apertures 38A of end cap 38. Apertures 38 may be defined by the broad side of end cap 38 such that apertures 18E open in longitudinal direction 36. Alternatively or additionally, apertures 18E may be defined by the sidewalls of end cap 38 such that apertures 18E open in a direction non-parallel or orthogonal to longitudinal direction 36.

[0064] An inner surface 38B of end cap 38 may be coated in a reflective material. In some embodiments, an inner surface 38B of end cap 38 is coated in a material exhibiting a high degree of specular reflectivity such as, for example, aluminum.

[0065] In some embodiments, a second optical head substantially similar to optical head 16 is in fluid communication with conduit 19 of reactor body 18. For example, the second optical head may be provided at or near the outlet 19C of reactor body 18. The second optical head may be oriented to direct radiation from its one or more UV- LEDs into conduit 19 such that air within conduit 19 may be irradiated by both optical head 16 and the second optical head. Air travelling through conduit 19 may travel through the second optical head in a similar way to how air travels through optical head 16 such that the second optical head does not substantially interrupt the flow of air through conduit 19.

[0066] In some embodiments, reactor body 18 is not required. For example, optical head 16 on its own may be installed into (e.g. retrofit or newly installed) or mounted in-line in an air duct or air conduit. In such embodiments, air flows into inlet 16A, through optical head, out of outlet 16C and into the duct or conduit, where the air is irradiated by radiation from UV-LEDs 20 that is collimated by lens assemblies 24.

[0067] When compared to devices for irradiating water, the air may flow through optical head 16 (e.g. through heat sink 30 and/or through backing 22 and into the region between UV-LEDs 20 and lens assemblies 24 and then through scaffolding 26). This may facilitate cooling of UV-LEDs 20 and associated components. This may also provide additional opportunities for disinfection of air as it flows through apparatus 10 (e.g. disinfection can occur within optical head 16 rather than only in reactor tube 18). Further, the ability of air to flow through optical head 16 may make it easier to provide optical head 16 with suitable mounting surfaces and/or mechanisms to facilitate installation into an air duct or air conduit.

[0068] Figure 2 (collectively Figures 2A to 2D) depicts an exemplary flow-through fluid (e.g. air) disinfection apparatus 110 according to an embodiment of the invention. Apparatus 110 may comprise a flow-through air disinfection apparatus 110 substantially similar to apparatus 10. For example, apparatus 110 comprises an optical head 116. In some embodiments, disinfection apparatus 110 comprises a reactor body 118 in fluid communication with optical head 116. As with apparatus 10, the presence of reactor body 118 is not mandatory. For convenience, components of apparatus 1 10 of the Figure 2 embodiment that are similar to components of apparatus 10 of the Figure 1 embodiment use similar reference numerals (e.g. wherein the digits and trailing letters of the reference numerals of like components are the same except for the first digit which is specific to the embodiment). This practice is continued herein such that components of the various apparatus that are similar to one another are described with similar reference numerals (e.g. wherein the digits and trailing letters of the reference numerals of like components are the same except for the first digit which is specific to the embodiment). Unless the context or description dictates otherwise, it should be understood that when referring to features and/or characteristics of components with similar reference numerals, the corresponding description should be understood to apply to any of the particular components with such similar reference numerals.

[0069] Air flows into apparatus 110 via inlet 112 in direction 136. Air may flow out of apparatus 1 10 via outlet 114 in direction 136 (or another direction non-parallel or orthogonal to direction 36). More precisely, air flows into an inlet 116A of optical head 116 and out of an outlet 116B of optical head 116. In some embodiments, air then flows into an inlet 118A of reactor body 1 18, through conduit 119 and out of an outlet 118B of reactor body 118. As with apparatus 10, air may be disinfected as it travels through at least a portion of apparatus 110 (e.g. between inlet 116A and outlet 116B and/or between inlet 118A and outlet 118B) and, as such, apparatus 110 may be referred to as a flow-through disinfection apparatus 110.

[0070] Optical head 116 differs, however, from optical head 16 (as illustrated) in that optical head 116 comprises a plurality of UV-LEDs 120 each having its own backing 122 (substantially similar to backing 22). Each UV-LED 120 of optical head 116 may be substantially similar to UV-LED 20. Each UV-LED 120 may direct radiation through a corresponding lens assembly 124 (substantially similar to lens assembly 24). Like optical head 16, optical head 116 may comprise an air filter (not shown) and/or a fan (not shown).

[0071] Each lens assembly 124 may in turn be supported individually or together by a scaffold 126 (substantially similar to scaffold 26). Like scaffold 26, scaffold 126 may be permeable to air flowing through apparatus 110. For example, scaffold 126 may define one or more apertures 126A through which air can flow. By allowing air to flow in the space between UV-LEDs 120 and in the space between UV-LEDs and lens assemblies 124, air can be disinfected in optical head 116 (e.g. in the space between UV-LEDs 120 and in the space between UV-LEDs and lens assemblies 124 in addition or alternative to being disinfected within reactor body 118).

[0072] Optical head 116 may comprise one or more heat sinks 130 (substantially similar to heat sink 30). In some embodiments, a single heat sink 130 is provided for all UV-LEDs 120 of apparatus 110. In some embodiments, an individual heat sink 130 is provided for each UV-LED 120 of apparatus (e.g. as illustrated in Figure 2).

[0073] In some embodiments, optical head 116 comprises one or more diffusers (not shown) substantially similar to diffuser 32. Alternatively (or additionally), apertures 126A of scaffold 126 may provide a similar effect to diffuser 32 such that scaffold 126 promotes mixing and/or uniform distribution of air as it travels through reactor body 118 and provision of a separate diffuser 32 may be avoided.

[0074] While Figures 1 and 2 illustrate flow-through fluid (e.g. air) disinfection apparatuses wherein UV-LEDs irradiate a conduit having a single conduit segment (e.g. conduit 19, 119), this is not mandatory. Similarly, while Figures 1 and 2 illustrate flow-through fluid (e.g. air) disinfection apparatuses wherein UV-LEDs irradiate a conduit from a single side, this is not mandatory. Fluid disinfection apparatuses, according to embodiments of the invention, may comprise multiple conduit segments in fluid communication with one another wherein each conduit segment is irradiated by one or more UV-LEDs. Moreover, each conduit segment may be irradiated from a plurality of sides (e.g. opposing sides) to promote better disinfecting of the fluid (e.g. air) flowing through the apparatus.

[0075] Figure 3 shows a flow-through fluid (e.g. air) disinfection apparatus 210 according to an embodiment of the invention. Apparatus 210 may be substantially similar to apparatus 10 except as follows.

[0076] Apparatus 210 comprises a reactor body 218 defining a conduit 219 having an inlet 212 and an outlet 214. Conduit 219 comprises a plurality of conduit segments 219A, 219B, 219C connected to one another in series by passages 221. Passages 221 may be located at or near the longitudinal ends of the conduit segments. More specifically, conduit segment 219A is connected to conduit segment 219B by passage 221 A and conduit segment 219C is connected to conduit segment 219C by passage 221 B. While conduit 219 is shown as comprising three segments, it should be understood that conduit 219 could comprise any number of segments greater than two connected by a suitable number of passages 221 .

[0077] In some embodiments, conduit segments 219A, 219B, 219C each extend in the same direction (e.g. direction 236) but this is not mandatory. For example, in some embodiments, adjacent segments of conduit 219 may be non-parallel. In the illustrated embodiments, 219A, 219B, 219C each extend in the direction 236 and passages 221 each open in a direction orthogonal to direction 236.

[0078] Each conduit segment 219A, 219B, 219C may be substantially similar to conduit 19 of apparatus 10. For example, an inner surface of each conduit segment may be coated in a photo-catalyst material, a reflective material and/or a semi- conductive material.

[0079] Fluid (e.g. air) may enter inlet 212 and travel through conduit 219 as follows before exiting through outlet 214. The fluid (e.g. air) may flow through conduit segment 218A, then through passage 221 A into conduit segment 219B, then through conduit segment 219B, then through passage 221 B into conduit segment 219C, then through conduit segment 219C and finally out of outlet 214. As the fluid travels through conduit 219, it may pass through and/or be irradiated by a plurality of optical heads 216 of apparatus 210.

[0080] Optical heads 216 of apparatus 210 may each be substantially similar to optical head 10 or optical head 1 10. For example, each optical head may comprise a UV-LED 220 (substantially similar to UV-LEDs 20, 120) supported by a backing (substantially similar to backings 22, 122). Each UV-LED 220 may direct radiation through a lens assembly 224 (substantially similar to lens assemblies 24, 124) supported by a scaffold (substantially similar to scaffolds 26, 126). Fluid (e.g. air) may be able to flow through optical heads 216 in a similar manner to how fluid (e.g. air) may flow through optical heads 16, 116 (e.g. so as to directly cool UV-LED 220). In some embodiments, optical heads 216 may differ from optical heads 10, 110 in that optical heads 216 may be housed directly within conduit 219 (e.g. without their own separate housing like housing 16C). Without housing 16C, fluid (e.g. air) may flow in and out of optical heads 216 in any direction. As such, where an optical head 216 is located in a corner (e.g. such as optical heads 216C, 216C, 216D, 216E), fluid may flow into the optical head 216 in direction 236 and out of the optical head 216 in a direction non-parallel (e.g. orthogonal) to direction 236. Similarly, where an optical head 216 is located away from a corner (e.g. such as optical heads 216A and 216F), fluid may flow in and out of the optical head 216 in the same direction (e.g. direction 236).

[0081] Apparatus 210 may comprise any suitable number of optical heads 216. For example, in the illustrated embodiments, apparatus 210 comprises six optical heads 216 (e.g. optical heads 216A, 216B, 216C, 216D, 216E, 216F) - one at each end of conduit segments 219A, 219B, 219C. In some embodiments, the number of optical heads 216 of apparatus 210 is dependent on the number of conduit segments of apparatus 210. For example, in the illustrated embodiment, two optical heads 216 are provided for each conduit segment 219A, 219B, 219C.

[0082] Optical heads 216 may be spaced apart within conduit 219 in any suitable manner. For example, in some embodiments, an optical head 216 is located at or near each end of a conduit segment. In the illustrated embodiment, optical head 216A is located at a first end of conduit segment 219A, optical head 216B is located at a second end (opposite the first end) of conduit segment 219A, optical head 216C is located at a first end of conduit segment 219B, optical head 216D is located at a second end (opposite the first end) of conduit segment 219B, optical head 216E is located at a first end of conduit segment 219C, and optical head 216F is located at a second end (opposite the first end) of conduit segment 219C. In other embodiments, one or more optical heads 216 may be provided away from an end of a conduit segment. Because fluid (e.g. air) can flow through optical head 216, it may be provide at any location with conduit 219 without substantially disrupting the flow of fluid through conduit 219.

[0083] In some embodiments, each optical head 216 may be arranged such that a principal emission axis of its UV-LED 220 (i.e. an axis along which the intensity of emitted radiation of UV-LED 220 is maximal) is parallel to the direction of elongation of the conduit segment in which it is located. This is not mandatory. In some embodiments, one or more optical heads 216 may be arranged such that a principal emission axis of its UV-LED 220 is non-parallel (e.g. orthogonal) to the direction of elongation of the conduit segment in which it is located.

[0084] In some embodiments, each optical head 216 within a conduit segment is arranged such that a principal emission axis of its UV-LED 220 is aligned in the same direction (e.g. in the direction of flow of fluid through that conduit segment). This is not mandatory. For example, optical heads 216 may be arranged in opposing pairs such that fluid located between optical heads 216 of a pair may be irradiated by both optical heads 216 of the pair. In the illustrated embodiment, two optical heads 216 are provided opposing one another in each conduit segment such that fluid (e.g. air) located between opposing optical heads 216 may be irradiated by both optical heads 216 concurrently. In other embodiments, one or more optical heads 216 within a conduit segment are arranged such that a principal emission axis of their respective UV-LEDs 220 is non-parallel (e.g. orthogonal) to the direction of flow of fluid through that conduit segment.

[0085] As compared to apparatus 10 and 110 where a relatively long conduit (e.g. conduit 18, 118) may be desirable to achieve sufficient disinfection of fluid (e.g. air), apparatus 210 may have a relatively shorter longitudinal length which may be desirable where space is limited.

[0086] Figure 4 shows a flow-through fluid (e.g. air) disinfection apparatus 310 according to an embodiment of the invention. Disinfection apparatus 310 is substantially similar to disinfection apparatus 210. For example, disinfection apparatus comprises a reactor body 318 which defines a conduit 319. A plurality of optical heads 316 (e.g. optical heads 316A, 316B) are located within conduit 319. Disinfection apparatus 310 differs from disinfection apparatus 210 as follows.

[0087] In contrast to optical heads 16, 116 and 216 which are arranged such that a principal emission axis of each of UV-LEDs 20, 120, 220 is parallel to the direction of flow in their respective apparatuses, optical heads 316 may be arranged within conduit 319 such that a principal emission axis of UV-LEDs 320 of each optical head 316 is non-parallel to the direction of flow of fluid through conduit 319. For example, in the illustrated embodiment, fluid (e.g. air) travels into reactor body 318 through inlet 312 in direction 336, through conduit 319 in direction 336 and out outlet 314 in direction 336 while the principal emission axis of each of UV-LEDs 320 of optical heads 316 is oriented in direction 325 wherein direction 325 is orthogonal to direction 336.

[0088] Optical heads 316A, 316B may be arranged opposite one another within conduit 319. However, unlike apparatus 210 where optical heads 216 are arranged opposite each other in direction 36 (which corresponds to the direction of flow of fluid in apparatus 10), optical heads 316A, 316B may be arranged opposite one another in direction 325 wherein direction 325 is orthogonal to direction 326 and/or orthogonal to the flow of fluid through conduit 319. Since optical heads 316A, 316B oppose one another, the principal emission axis of each of UV-LEDs 320 is oriented opposite the direction of principal emission of UV-LEDs 320 of optical head 316A in direction 325.

[0089] While each optical head 316 is depicted as comprising a plurality of UV-LEDs 320, it should be understood that this is not mandatory and, instead, each optical head 316 could comprise a single UV-LED 320. Further, while the illustrated embodiment only depicts two optical heads 316, it should be understood that one optical head 316 or more than two optical heads 316 could be provided. Further still, while the illustrated embodiment depicts a conduit 319 having only a single conduit segment, it should be understood that multiple conduit segments could be provided.

[0090] With this configuration, the cross-sectional dimension D may be large relative to the length L in the longitudinal (flow) direction 36 when compared to apparatus 10, 110, although this is not necessary. [0091] In other embodiments, optical heads 316 may be located at other additional or alternative locations within reactor body 318.

[0092] Figure 5 shows a flow-through fluid (e.g. air) disinfection apparatus 410 according to an embodiment of the invention. Disinfection apparatus 410 is substantially similar to disinfection apparatus 310. For example, disinfection apparatus comprises a reactor body 418 which defines a conduit 419. A plurality of optical heads 416 (e.g. optical heads 416A, 416B) are located within conduit 419. Disinfection apparatus 410 differs from disinfection apparatus 310 as follows.

[0093] In contrast to apparatus 310 where inlet 312 is located on an opposite end of reactor body 318 to outlet 314, inlet 412 of apparatus 410 is located on a same side of reactor body 418 as outlet 414. In this way, fluid (e.g. air) enters conduit 419 defined by reactor body 418 in a first direction 436A and leaves conduit 419 in a second direction 436B, wherein first direction 436A is parallel and opposite second direction 436B.

[0094] Like optical heads 316A, 316B, optical heads 416A, 416B may be arranged opposite one another within conduit 419 in direction 425 wherein direction 425 is orthogonal to directions 436A, 436B. As such, while the principal emission axis of each of UV-LEDs 420 is oriented in direction 425, the direction of principal emission of UV-LEDs 420 of optical head 416A is opposite the direction of principal emission of UV-LEDs 420 of optical head 416B. This is not mandatory. One or more optical heads 416 could be arranged with a principal emission axis oriented in first direction 436A or second direction 436B or non-parallel to first direction 436A and direction 425.

[0095] While each optical head 416 is depicted as comprising a plurality of UV-LEDs 420, it should be understood that this is not mandatory and, instead, each optical head 416 could comprise a single UV-LED 420. Further, while the illustrated embodiment only depicts two optical heads 416, it should be understood that one or more than two optical heads 416 could be provided. Further still, while the illustrated embodiment depicts a conduit 419 having only a single conduit segment, it should be understood that multiple conduit segments could be provided.

[0096] In other embodiments, optical heads 416 may be located at other additional or alternative locations within reactor body 418.

[0097] Figure 6 shows a flow-through fluid (e.g. air) disinfection apparatus 510 according to an embodiment of the invention. Disinfection apparatus 510 is substantially similar to disinfection apparatus 10. For example, apparatus 510 comprises an optical head 516 substantially similar to optical head 16 and a reactor body 518 substantially similar to reactor body 18.

[0098] In the Figure 6 embodiment, diffuser 532 is shaped to cause the fluid (e.g. air) flowing within reactor body 518 to have a velocity profile which is generally higher velocity at locations relatively close to the cross-sectional center of conduit 519 and generally lower velocity at locations relatively far from the cross-sectional center of conduit 519. This velocity profile may be achieved by diffusing apertures 534 of diffuser 532. In some embodiments, diffuser 532 is shaped to substantially block fluid from flowing through apparatus 10 except through apertures 534. In some embodiments, apertures 534 open in a direction orthogonal to the direction of the flow of fluid through apparatus 510. For example, in the illustrated embodiment, fluid generally flows into and out of apparatus 510 in direction 536 while apertures 534 open in direction 525, wherein direction 525 is orthogonal to direction 536. In some embodiments, apertures 534 are relatively closer to inner walls of apparatus 510 than to a cross-sectional center of apparatus 510.

[0099] This velocity profile (wherein the velocity is relatively higher closer to a cross- sectional center of reactor body 518) may be correlated with an intensity profile of radiation emitted from optical head 516, which may exhibit higher radiation at locations relatively close to the cross-sectional center of conduit 519 and generally less radiation at locations relatively far from the cross-sectional center of conduit 519. By matching the velocity profile to the radiation profile, radiation generated by optical head 516 may more effectively disinfect fluid travelling through apparatus 510 (e.g. by focusing radiation on the volume where the fluid velocity is highest and by not wasting radiation in the volumes where fluid velocity is lowest).

[0100] In other embodiments, optical heads 516 may be located at other additional or alternative locations within reactor body 518.

[0101] Figure 7 shows a flow-through fluid (e.g. air) disinfection apparatus 610 according to an embodiment of the invention. Disinfection apparatus 610 is substantially similar to disinfection apparatus 510. For example, apparatus 610 comprises an optical head 616 substantially similar to optical head 516 and a reactor body 618 substantially similar to reactor body 518. Optical head 616 comprises a diffuser 632 (and corresponding apertures 634) substantially similar to diffuser 532 (and corresponding apertures 534).

[0102] Apparatus 610 differs from apparatus 510 in that the number of UV-LEDs 620 and corresponding lens assemblies 624 in optical head 616 is greater than the number of UV-LEDs 520 and corresponding lens assemblies 524 in optical head 516. Specifically, optical head 616 comprises three UV-LEDs 620 and three corresponding lens assemblies 624 although it should be understood that optical head 616 (like all optical heads described herein) could comprise any suitable number of UV-LEDs 620 and corresponding lens assemblies 624.

[0103] In other embodiments, optical heads 616 may be located at other additional or alternative locations within reactor body 618.

[0104] Figure 8 shows a flow-through fluid (e.g. air) disinfection apparatus 710 according to an embodiment of the invention. Disinfection apparatus 710 is substantially similar to disinfection apparatus 610. For example, apparatus 710 comprises an optical head 716 substantially similar to optical head 616 and a reactor body 718 substantially similar to reactor body 618.

[0105] Apparatus 710 differs from apparatus 610 in that apertures 734 of diffuser 732 are arranged differently from apertures 634 of diffuser 632. In particular, apertures 734 open in direction 736 parallel to the flow of fluid through apparatus 710. Further, apertures are spaced apart evenly across diffuser 632 to cause air flow within reactor body 718 to mix as it travels through conduit 719 between inlet 712 and outlet 714.

[0106] In other embodiments, optical heads 716 may be located at other additional or alternative locations within reactor body 718.

[0107] Figure 9 shows a flow-through fluid (e.g. air) disinfection apparatus 810 according to an embodiment of the invention. Disinfection apparatus 810 is substantially similar to disinfection apparatus 610. For example, apparatus 810 comprises an optical head 816 substantially similar to optical head 616 and a reactor body 818 substantially similar to reactor body 618.

[0108] Optical head 816 may comprise a plurality of UV-LEDs 820A, 820B, 820C (collectively UV-LEDs 820), a plurality of lens assemblies 824A, 824B, 824C (collectively lens assemblies 824) and a diffuser 832. Diffuser 832 may be substantially similar to diffuser 632. [0109] Since diffuser 832 of apparatus 810 is substantially similar to diffuser 632, the velocity of fluid travelling through apparatus 810 may be relatively higher closer to a cross-sectional center of reactor body 818 and relatively lower closer to the inner walls of reactor body 818. As discussed herein, it may be desirable to match a radiation intensity profile output by UV-LEDs 820 (and lens assemblies 824) to the profile of the velocity of fluid travelling through reactor body 818. More specifically, if velocity is higher near the center of reactor body 818, it may be desirable that radiation intensity output by UV-LEDs 820 (and lens assemblies 824) is higher near the center of reactor body 818 and conversely, if velocity is lower away from the center of reactor body 818, it may be desirable that radiation intensity output by UV- LEDs 820 (and lens assemblies 824) is lower away from the center of reactor body 818. This matching may be achieved by shaping diffuser 832 to achieve a desired velocity profile and/or by configuring UV-LEDs 820 and/or lens assemblies 820 to achieve a desired radiation profile.

[0110] For example, to achieve a desired radiation profile within conduit 819, one or more of the following could be adjusted:

• the shape of the lens (or lenses) of one or more lens assemblies 824 (e.g. an asymmetric lens could be employed);

• the location of the lens (or lenses) of one or more lens assemblies 824 relative to their corresponding UV-LEDs;

• the angular orientation of the lens (or lenses) of one or more lens assemblies 824 relative to their corresponding UV-LEDs;

• the location of one or more UV-LEDs relative to fluid conduit 819;

• the angular orientation of one or more UV-LEDs relative to fluid conduit 819;

• etc.

[0111] In the illustrated embodiment, lens assemblies 824A, 824C are shifted relatively toward the cross-sectional center of the optical head as compared to their corresponding UV-LEDs thereby creating a radiation profile in which radiation intensity output by UV-LEDs (and lens assemblies 824) is relatively higher toward a center of reactor body 818 and relatively lower away from a center of reactor body 818.

[0112] In other embodiments, optical heads 816 may be located at other additional or alternative locations within reactor body 818. [0113] Figure 10 shows a flow-through fluid (e.g. air) disinfection apparatus 910 according to an embodiment of the invention. Disinfection apparatus 910 is substantially similar to disinfection apparatus 210. For example, apparatus 910 comprises a reactor body 918 that defines a conduit 919 having a plurality of conduit segments 919A, 919B, 919C, 919D, 919E connected in series by passages 921 . However, unlike apparatus 210, only a single optical head is provided within conduit 919 to irradiate fluid within conduit segments 919A, 919B, 919C, 919D, 919E. One or more reflective surfaces 937 (e.g. mirrors) may be provided within conduit 919 to achieve sufficient irradiation within conduit segments 919B, 919C, 919D, 919E which are not directly irradiated by optical head 916.

[0114] Reflective surfaces 937 may be provided opposite optical head 916 within conduit segment 919A and at or near the longitudinal ends of each other conduit segment 919B, 919C, 919D, 919E. For example, a first reflective surface 937 located opposite optical head 916 may reflect radiation in conduit segment 919A from optical head 916 through a first passage 921 and into conduit segment 919B while a second reflective surface 937 may in turn direct radiation reflected from the first reflective surface 937 along conduit segment 919B. This arrangement may be repeated for subsequent pairs of reflective surfaces 937 until the radiation is in turn directed into conduit segment 919E.

[0115] Apparatus 910 may only include a single optical head 916 since UV radiation is not appreciably attenuated as it travels through air. However it should be understood that apparatus 910 could comprise one or more additional optical heads 916 within conduit 919 (e.g. located at similar locations to optical heads 216 of apparatus 210).

[0116] In other embodiments, optical heads 916 may be located at other additional or alternative locations within reactor body 918 or conduit segments 919.

Interpretation of Terms

[0117] Unless the context clearly requires otherwise, throughout the description and the claims:

“comprise”, “comprising”, and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”;

• “connected”, “coupled”, or any variant thereof, means any connection or coupling, either direct or indirect, between two or more elements; the coupling or connection between the elements can be physical, logical, or a combination thereof;

• “herein”, “above”, “below”, and words of similar import, when used to describe this specification, shall refer to this specification as a whole, and not to any particular portions of this specification;

• “or”, in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list;

• the singular forms “a”, “an”, and “the” also include the meaning of any appropriate plural forms.

[0118] Words that indicate directions such as “vertical”, “transverse”, “horizontal”, “upward”, “downward”, “forward”, “backward”, “inward”, “outward”, “vertical”, “transverse”, “left”, “right”, “front”, “back”, “top”, “bottom”, “below”, “above”, “under”, and the like, used in this description and any accompanying claims (where present), depend on the specific orientation of the apparatus described and illustrated. The subject matter described herein may assume various alternative orientations. Accordingly, these directional terms are not strictly defined and should not be interpreted narrowly.

[0119] Where a component (e.g. a software module, processor, assembly, device, circuit, etc.) is referred to above, unless otherwise indicated, reference to that component (including a reference to a “means”) should be interpreted as including as equivalents of that component any component which performs the function of the described component (i.e. , that is functionally equivalent), including components which are not structurally equivalent to the disclosed structure which performs the function in the illustrated exemplary embodiments of the invention.

[0120] Specific examples of systems, methods and apparatus have been described herein for purposes of illustration. These are only examples. The technology provided herein can be applied to systems other than the example systems described above. Many alterations, modifications, additions, omissions, and permutations are possible within the practice of this invention. This invention includes variations on described embodiments that would be apparent to the skilled addressee, including variations obtained by: replacing features, elements and/or acts with equivalent features, elements and/or acts; mixing and matching of features, elements and/or acts from different embodiments; combining features, elements and/or acts from embodiments as described herein with features, elements and/or acts of other technology; and/or omitting combining features, elements and/or acts from described embodiments.

[0121] Various features are described herein as being present in “some embodiments”. Such features are not mandatory and may not be present in all embodiments. Embodiments of the invention may include zero, any one or any combination of two or more of such features. This is limited only to the extent that certain ones of such features are incompatible with other ones of such features in the sense that it would be impossible for a person of ordinary skill in the art to construct a practical embodiment that combines such incompatible features. Consequently, the description that “some embodiments” possess feature A and “some embodiments” possess feature B should be interpreted as an express indication that the inventors also contemplate embodiments which combine features A and B (unless the description states otherwise or features A and B are fundamentally incompatible).

[0122] It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions, omissions, and sub-combinations as may reasonably be inferred. The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.

Claims

WHAT IS CLAIMED IS:

1 . An apparatus for treating air with ultraviolet radiation, the apparatus comprising: an optical head comprising: a housing defining an inlet through which the air can enter the optical head in a first direction and an outlet through which the air can exit the optical head; an ultraviolet light emitting diode (UV-LED) supported within the housing to emit radiation to thereby irradiate the air.

2. An apparatus for treating air according to claim 1 or any other claim herein wherein at least some of the air is routed to pass around the UV-LED as the air passes through the housing to thereby assist in cooling the UV-LED.

3. An apparatus for treating air according to claim 1 or any other claim herein wherein at least some of the air is routed to come into thermal contact with the UV-LED as the air passes through the housing to thereby assist in cooling the UV-LED.

4. An apparatus for treating air according to claim 1 or any other claim herein wherein the UV-LED is supported within the housing by a backing and the backing defines one or more backing apertures wherein at least some of the air is routed to pass through the one or more backing apertures into thermal contact with the UV-LED as the air passes through the housing to thereby assist in cooling the UV-LED.

5. An apparatus for treating air according to any one of claims 3 and 4 or any other claim herein wherein the backing comprises a circuit board with components for directing current to the UV-LED.

6. An apparatus for treating air according to any one of claims 3 to 5 or any other claim herein wherein the optical head defines: a first path for a portion of the air to travel from the inlet to the outlet, the first path travelling through the one or more backing apertures and into thermal contact with the UV-LED; and a second path for another portion of the air to travel around the backing. An apparatus for treating air according to any one of claims 1 to 6 or any other claim herein wherein the optical head comprises a lens assembly for shaping the radiation emitted by the UV-LED and wherein the lens assembly is supported by a scaffold within the housing. An apparatus for treating air according to claim 7 or any other claim herein wherein the scaffold defines one or more scaffold apertures such that at least some of the air is routed to pass through the scaffold apertures after the air passes the UV-LED. An apparatus for treating air according to any one of claims 7 and 8 or any other claim herein wherein the lens assembly comprises one or more lenses configured such that 50% of the power of the radiation output from the one or more lenses is within a solid angle of 10 degrees from a principal radiation direction of the UV-LED. An apparatus for treating air according to any one of claims 7 and 8 or any other claim herein wherein the lens assembly comprises one or more lenses configured such that 50% of the power of the radiation output from the one or more lenses is within a solid angle of 8 degrees from a principal radiation direction of the UV-LED. An apparatus for treating air according to any one of claims 7 and 8 or any other claim herein wherein the lens assembly comprises one or more lenses configured such that 60% of the power of the radiation output from the one or more lenses is within a solid angle of 10 degrees from a principal radiation direction of the UV-LED. An apparatus for treating air according to any one of claims 7 and 8 or any other claim herein wherein the lens assembly comprises one or more lenses configured such that 60% of the power of the radiation output from the one or more lenses is within a solid angle of 8 degrees from a principal radiation direction of the UV-LED. An apparatus for treating air according to any one of claims 7 and 8 or any other claim herein wherein the lens assembly comprises one or more lenses configured such that 70% of the power of the radiation output from the one or more lenses is within a solid angle of 10 degrees from a principal radiation direction of the UV-LED. An apparatus for treating air according to any one of claims 7 and 8 or any other claim herein wherein the lens assembly comprises one or more lenses configured such that 70% of the power of the radiation output from the one or more lenses is within a solid angle of 8 degrees from a principal radiation direction of the UV-LED. An apparatus for treating air according to any one of claims 1 to 14 or any other claim herein wherein the optical head comprises a heat sink in thermal contact with the backing. An apparatus for treating air according to any one of claims 1 to 14 or any other claim herein wherein the optical head comprises a heat sink in thermal contact with the UV-LED. An apparatus for treating air according to any one of claims 15 and 16 or any other claim herein wherein at least some of the air is routed into contact with the heat sink as the air passes through the housing, thereby cooling the heat sink. An apparatus for treating air according to any one of claims 15 and 16 or any other claim herein wherein the heat sink defines one or more heat sink apertures and at least some of the air is routed through the one or more heat sink apertures as the air passes through the housing. An apparatus for treating air according to any one of claims 1 to 18 or any other claim herein wherein the optical head comprises a diffuser to distribute air, the diffuser located between the UV-LED and the outlet. An apparatus for treating air according to claim 19 or any other claim herein wherein the diffuser promotes a uniform distribution of air as it exits through the outlet of the optical head. An apparatus for treating air according to claim 19 or any other claim herein wherein the diffuser promotes a distribution of air wherein a velocity of the air is higher near a cross-sectional center of the optical head as the air exits through the outlet of the optical head. An apparatus for treating air according to claim 19 or any other claim herein wherein the diffuser promotes a distribution of air velocity as the air exits through the outlet of the optical head wherein the distribution of air velocity of at least a portion of the air is substantially correlated with a distribution of radiation intensity that is emitted from the UV-LED. An apparatus for treating air according to claim 19 or any other claim herein wherein the diffuser promotes a distribution of air velocity as the air exits through the outlet of the optical head wherein the distribution of air velocity of at least a portion of the air is substantially correlated with a distribution of radiation intensity that is refracted by a lens assembly. An apparatus for treating air according to any one of claims 19 to 23 or any other claim herein wherein the diffuser defines one or more diffuser apertures. An apparatus for treating air according to claim 24 or any other claim herein wherein the one or more diffuser apertures open in a second direction, nonparallel to the first direction. An apparatus for treating air according to claim 24 or any other claim herein wherein the one or more diffuser apertures open in a second direction, orthogonal to the first direction. An apparatus for treating air according to any one of claims 24 to 26 or any other claim herein wherein the diffuser substantially blocks the air from reaching the outlet unless the air passes through the one or more diffuser apertures. An apparatus for treating air according to any one of claims 1 to 27 or any other claim herein comprising a reactor body in fluid connection with the outlet such that the air flows out the outlet and into a conduit defined by the reactor body and wherein the UV-LED irradiates the air inside the conduit. An apparatus for treating air according to claim 28 or any other claim herein wherein a longitudinally extending inner surface of the conduit has a lower degree of specular reflectivity than a surface of an end wall of the conduit, the end wall located opposite to the outlet of the optical head. An apparatus for treating air according to claim 28 or any other claim herein wherein a longitudinally extending inner surface of the conduit has a higher degree of diffuse reflectivity than a surface of an end wall of the conduit, the end wall located opposite to the outlet of the optical head. An apparatus for treating air according to any one of claims 29 and 30 or any other claim herein wherein the longitudinally extending inner surface of the conduit comprises polytetrafluoroethylene (PTFE). An apparatus for treating air according to any one of claims 29 to 31 or any other claim herein wherein the surface of the end wall comprises aluminum. An apparatus for treating air according to claim 22 or any other claim herein wherein a longitudinally extending inner surface of the conduit comprises a photocatalyst material. An apparatus for treating air according to claim 33 or any other claim herein wherein a longitudinally extending inner surface of the conduit comprises a semi-conductive photocatalyst material. An apparatus for treating air according to claim 34 or any other claim herein wherein the semi-conductive photocatalyst material comprises TiC An apparatus for treating air according to claim 28 or any other claim herein comprising a second optical head in fluid communication with an outlet of the reactor body and configured to direct second radiation into the conduit of the reactor body, wherein the second optical head comprises substantially the same features and components as the optical head according to any one of claims 1 to 30 or any other claim herein. An apparatus for treating air according to any one of claims 28 to 36 or any other claim herein wherein the conduit comprises a plurality of conduit segments in fluid communication with one another. An apparatus for treating air according to claim 37 or any other claim herein comprising at least one additional optical head located in each conduit segment wherein each of the at least one additional optical heads comprises substantially the same features and components as the optical head according to any one of claims 1 to 30 or any other claim herein. An apparatus for treating air according to claim 37 or any other claim herein wherein the at least one additional optical head comprises a plurality of additional optical heads and the plurality of additional optical heads comprises a pair of optical heads opposite one another in a first conduit segment of the plurality of conduit segments. An apparatus for treating air according to claim 37 or any other claim herein comprising one or more reflective surfaces to reflect radiation emitted by the UV-LED into a first conduit segment of the plurality of conduit segments from the first conduit segment into a second conduit segment of the plurality of conduit segments. An apparatus for treating air according to any one of claims 1 to 40 or any other claim herein comprising: a housing containing the optical head and a second optical head wherein the housing comprises a housing inlet to direct the air into the inlet and the second inlet and a housing outlet through which the air can exit the housing and the second optical head comprises the features and components of any one of claims 1 to 40 or any other claim herein. An apparatus for treating air according to claim 42 or any other claim herein comprising a reactor body connected to the housing outlet wherein the UV- LED and the second UV-LED irradiate the air inside the reactor body. An apparatus for treating air according to any one of claims 1 to 42 or any other claim herein wherein the inlet opens in the first direction and the outlet opens in a third direction, the third direction non-parallel to the first direction. An apparatus for treating air according to any one of claims 1 to 42 or any other claim herein wherein the inlet opens in the first direction and the outlet opens in a third direction, the third direction orthogonal to the first direction. An apparatus for treating air according to any one of claims 1 to 44 or any other claim herein wherein the UV-LED is supported to emit radiation with a principal axis of emission aligned in a first direction. An apparatus for treating air according to any one of claims 1 to 44 or any other claim herein wherein the UV-LED is supported to emit radiation with a principal axis of emission aligned in a fourth direction, the fourth direction nonparallel to the first direction. An apparatus for treating air according to any one of claims 1 to 44 or any other claim herein wherein the UV-LED is supported to emit radiation with a principal axis of emission aligned in a fourth direction, the fourth direction orthogonal to the first direction. An apparatus for treating air according to any one of claims 1 to 44 or any other claim herein wherein the UV-LED is supported to emit radiation with a principal axis of emission aligned in a fourth direction, the fourth direction nonparallel to a direction of flow of air through the optical head. An apparatus for treating air according to any one of claims 1 to 44 or any other claim herein wherein the UV-LED is supported to emit radiation with a principal axis of emission aligned in a fourth direction, the fourth direction orthogonal to a direction of flow of air through the optical head. An apparatus for treating air according to any one of claims 1 to 49 or any other claim herein wherein the optical head comprises a fan for drawing the air in through the inlet and pushing the air out through the outlet. An apparatus for treating air according to any one of claims 1 to 50 or any other claim herein comprising an air filter located upstream of the optical head such that the air passes through the filter before passing through the optical head. An apparatus for treating air according to any one of claims 1 to 50 or any other claim wherein the optical head comprises an air filter. An apparatus for treating air according to any one of claims 1 to 52 or any other claim herein wherein the optical head comprises: a second ultraviolet light emitting diode (UV-LED) supported within the housing to emit the radiation to thereby irradiate the air. An apparatus for treating air according to any one of claims 1 to 53 or any other claim herein wherein the optical head comprises: a plurality of ultraviolet light emitting diodes (UV-LEDs) supported within the housing to emit the radiation to thereby irradiate the air. A method for treating air, the method comprising: flowing air through an apparatus for treating air according to any one of claims 1 to 54 or any other claim herein; and causing the UV-LED to emit radiation to thereby disinfect the air. A method according to claim 55 or any other claim herein comprising: installing the apparatus for treating air in an air duct of an HVAC system. Apparatus comprising any features, combinations of features and/or subcombinations of features described in this disclosure including the description and/or drawings. Methods comprising any features, combinations of features and/or subcombinations of features described in this disclosure including the description and/or drawings.