WO2022153128A2

WO2022153128A2 - Intense upper air uvc projector combined with a uvc absorbing screen, an assisted convection operating coanda effect & a human presence detection.

Info

Publication number: WO2022153128A2
Application number: PCT/IB2022/000036
Authority: WO
Inventors: Jannick Jacques SIMERAY
Original assignee: Holt, Stuart
Priority date: 2021-01-15
Filing date: 2022-01-14
Publication date: 2022-07-21
Also published as: WO2022153128A3

Abstract

Wall mounted UVC Projector projecting an ultraviolet light germicidal under all the ceiling to all the walls of a occupied room, said walls being covered optionally by a UVC absorbing wall paper, As another option a Coanda effect assists the convection. As another option a focused infrared senses the human presence under the ceiling.

Description

Invention’s title: Intense UPPER AIR UVC projector combined with a UVC absorbing screen, an assisted convection operating Coanda effect & a human presence detection.

[1 ] Upper air sterilization using UVC was first demonstrated by Dr Wells in 1937 in the USA. It has been installed in high ceiling classrooms 11 fig 1 for stopping measles outbreaks by using a UVC light fixture. According to the definition of the 'ILLUMINATING ENGINEERING SOCIETY', IES, a UVC luminary combines a UVC tube 13 emitting 254 nm wavelength light secured above a diffuser 12 for distributing the light to the ceiling, where it deactivates the virus within the emission lobe 14. The process has demonstrated its effectiveness.

[2] Later, as direct exposure to UVC of occupants below has been confirmed harmful to the eyes over an average power of 0.2uW/cm², the said IES committee issued a recommendation, currently implemented by all manufacturers and installers:

[3] If the ceiling height is less than 3 meters the fixture must be installed at least 2.1 meter high and be covered by louvers 21 fig2 which pass only upward rays and absorbs all others.

[4] This reduces the direct and indirect exposition of the present occupants below, but also wastes most of the light emitted by the UVC source. It also illuminates the ceiling, which backscatters UVC onto the occupants.

[5] The louvers are generally plates separated by 1 cm and 5 cm long, allowing 1/5 + 1/5 = 0.4 rad = 23 ° emission angle to pass through & absorbing the remainder over 340 °. Such louvers are therefore not selective enough, 0.4 radians represents 2 m on a wall 5 m in front. It is then necessary to orient it upwards therefore to illuminate the ceiling to preserve the occupants. The energetic efficiency of this single lighting system is around 6 %, 94% of the power is absorbed and therefore lost.

[6] An open luminary or a louvered one is characterized in that a fraction of the light emitted by the UVC source illuminates directly said ceiling or wall in front, without having been neither reflected nor diffused by a surface, the louver 21 or the diffuser 12 for example.

[7] 80 years later, UPPER AIR UVC is still implemented by combining a wide light diffuser and louvers absorbing most of the UVC emission outside of a useful angle, which is ultimately not narrow enough.

[8] The strong irradiation zone is represented by a lobe 21 . It is thin near the luminary and diverges by 23°, it is thin far away from the luminary because of the horizontal divergence. It is thick in the middle.

[9] By limiting the range of the germicidal illumination to a distance shorter than the room, the installer ensures the safety of the occupants.

[10] So not only do the louvers absorb 94% of the source’s power, but they impose to reduce the Upper air luminary’s intensity because of the excessive vertical divergence causing reflections on the ceiling.

[11 ] Inventors or scientists pretend it is inefficient and costly to distribute widely the light to operate only a narrow angle and waste most of the solid angle. But those skilled in the art are satisfied, such luminaries have been selling (expensive) for 80 years. Why then question a conception that has become a tradition?

[12] Because for example :

[13] a. a powerful illumination causes a faster deactivation of viruses,

[14] b. a faster deactivation operates a complete sterilization of the air before it is recycled down by natural convection or faster by an assisted convection (The invention performs 99.99% kill in 2 minutes corresponding to 280 uW/cm² measured at 2 meters in front of said 28W electric projector).

[15] c. an illumination distributed on a wide horizontal sector (180°) ensures that all the upper air is sterilized before being re-circulated down.

[16] d. the installation does only require an electrician and no more an expert.

[17] The only remaining question regarding the occupants’ safety is the backscattering rate of the illuminated walls. This backscatter should remain under the limit of 0.2 uW / cm² for 8 hours continuous exposition, or 6 m J / cm² in the middle of the room. Some wall coatings materials exceed 50% lambertian backscattering rate.

[18] Can those skilled in the art arbitrarily increase the power of the source of a louvered luminary for increasing the illumination’s intensity under the ceiling?

[19] No, because by increasing the source’s power he inflates the lobe 22 becoming the lobe 23 exposing the occupants and the ceiling even more.

[20] Having a low vertical divergence and a large horizontal divergence helps focusing a powerful emission on the top of the 4 walls, on the largest possible perimeter, without illuminating the ceiling Fig 4.

[21] A prior art research has been made and enumerate several documents JP 2001061947, US2014084185, US6333509, FR8988299, CN111282012. Those documents expose inventions having no relation to the present application’s purpose which needs to be understood this way only: How to kill germs in the air fast with UVC in an occupied room, without exposing the occupants bellow even to limited levels.

[22] Of course the anterior art discloses UVC tube and mirror combinations, mainly for increasing the intensity on an object, by ignoring the residual level of illumination around (below) this object.

[23] The first application for a transistor playing music has not been rejected because anticipated by NPN transistors with 3 legs, their main components. The way those 3 legs components are assembled makes the invention.

[24] The examination will certainly to consider the purpose, sterilization of the air safely over the occupants; the background art, lighting, something that we can assimilate to blind artillery, then the invention, an accurate optical conjugation between a linear source and a perimeter, which we may assimilate to a sniper task.

[25] The invention’s purpose is therefore increasing the UVC intensity under the whole ceiling without exceeding the standard dose received by the occupants bellow. The probability that any UVC photon emitted by the source 13 hits a germ on its path represents the merit of the projector. This probability is proportional to the average free path length of all emitted UVC photons. The less photons absorbed by the projector, the more focused on the remote opposite wall, the higher is the projector’s merit. The invention is carried out by projecting a thin horizontal UVC stratum to the top of the wall, combined with the absorption of this UVC directly on the walls, so the walls do not backscatter down to the occupants.

[26] The invention achieves the first germicidal light projector on an absorbent screen. It projects the image 33 of a linear UVC light source 13 on the entire top of the four walls of a room 11 , without illuminating its occupants bellow.

[27] This projector-screen approach is new and is not disclosed by in any prior document because it relates to the cinema and no longer to the lighting field.

[28] A projector is according to IES a lighting device which, by means of mirrors is designed to concentrate the light within a limited angle to increase its intensity. A projector is also an optical device that projects intense light rays in a parallel beam or a device used to project images onto a screen.

[29] A projector is therefore exactly the opposite of a luminary which distributes the light or of a luminary combined with louvers which absorb most of it after. The projector orients the light in the useful direction for increasing its intensity without absorbing it.

[30] The divergent light source never illuminates the screen or the walls directly, but via a mirror only.

[31] The invention includes a linear source of UVC light 13, as non-exclusive example a mercury or amalgam vapor tube, or UVC Led Strip, both located at the focal line F of a half parabolic mirror 31. Said source 13 is and surrounded by a second mirror 32. Said parabolic half-mirror 31 is secured to the top of the supporting wall and its main direction of emission is arbitrarily horizontal.

[32] The second mirror 32 directs almost all the light 13 towards the main mirror 31 which projects it to the top of the other walls of the room 11 . The light which does not reach the mirror 31 reaches the supporting wall from both sides. Thus, the top of all the walls of the room 11 is illuminated by a horizontal line, under the entire ceiling and over a horizontal angular sector close to 180°.

[33] The optical object is for example a tube 13, its top is located just under the focal line F, and the mirror 31 conjugates its inverted image 33 on the walls 11 in front. The image of the top of the tube (or of UVC led Strip respectively) is sharp and free of any aberrations because the tube’s top coincides exactly with the focal line.

[34] Thanks to this perfect optical conjugation, the contrast between the illuminated zone and the spared zone just below is abrupt as illustrated by the intensity curve 34. This contrast is even steeper when the focal length of the mirror 31 is longer or the room is shorter.

[35] If for example the UVC tube is diameter 15 mm & the focal length of the mirror 31 also 15 cm, the light is concentrated in an angle of 0.1 radian, 6 ° only, representing only 50 cm at 5 m at the top of the wall, this without illuminating the ceiling nor the occupants.

[36] According to the invention, the mirrors 31 and 32 and the UVC light source 13 are profiles sharing a common axis.

[37] According to one embodiment of the invention, the UVC source 13 is mercury or amalgam vapor tube also contains a perfect C shaped backscattering material whose opening is facing the mirror 31 . The emitted light from by the tube 13 is then diffused several times by the backscattering material inside the tube before passing through the tube’s quartz envelope in the direction of the mirror 31 . According to another embodiment option, said source 13 is an alignment of UVC LED on a printed circuit.

[38] According to the invention :

[39] a. all the UVC light emitted by the source & located under the focal line F is concentrated in a stratum just above the horizontal plane of symmetry of the mirror 31 ,

[40] b. no UVC light

- is absorbed by the projector

- is emitted directly through this downward symmetry plane

- is emitted frontally without having been concentrated by the mirror 31 is emitted towards the ceiling. [41] According to the invention both mirrors 31 and 32 are made of commercial bended cold rolled aluminum mirrors, formed by a rolling mill. All bendable commercial aluminum mirrors sheets are made according to this process.

[42] All commercial cold rolled aluminum mirrors are subject to the same surface defects, parallel microscopic lines, resulting from the crystalline non homogeneity of its alloy when compressed by the rollers. Those lines are oriented along the rolling path, which is perpendicular to the roller’s shaft. Those lines diffract any normal light significantly in an axial direction especially for short waves lengths like UVC.

[43] According to the invention, the said mirrors 31 and 32 are made of cold rolled aluminum mirrors, which are bended around the same axis as when cold rolled. As a consequence, in the room, the diffractive microscopic line directions belong to a vertical plan and diffract the light only horizontally.

[44] Thanks to this accurate bending orientation not only do the mirrors avoid diffracting the UVC light down and up which is unsafe, but it contributes beneficially by diffracting it horizontally, which enlarges the horizontal angular distribution and coverage under the ceiling.

[45] With a projector illuminating 285 uW/cm² at 2m in front, a ratio of 3 between the down leakages has been measured 70 cm bellow the horizontal projector at 1 meter in front. A level of down leakage of 0,6 uW/cm² was measured when both the diffraction lines of mirrors 31 and 32 were in an horizontal plan. The level of 0,2 uW/cm² was measured only when the diffraction lines were exactly in a vertical plan and said rolling axis of said mirrors horizontal.

[46] (No anterior art and no academic exists on this matter, those rolling lines are not a problem for any luminary distributing visible or UVC light, it is also no problem when the purpose is illuminating a surface for disinfecting it with UVC. It becomes only a problem with UVC, a short wavelength, when the purpose is implementing an accurate optical conjugation, for strongly illuminating the virus and not even weakly the room’s occupants 50 cm below the emission’s peak.

[47] A discrimination rate 0.2/285 = 0.0007 does not belong to the technical field of lighting but to the field of optics, There is no previous art for this. [48] According to a first option, the invention comprises a fan assisting the natural convection by aspiring the air from the ceiling to recycle it down along the wall. This fan is preferably a tangential turbine sharing common axis with the mirrors 31 32 and the source 13.

[49] This re-circulates healthy air in the occupied zone and more quickly draws the exhaled air into the deactivation zone under the ceiling. This fan has preferably an air outlet tangent to the wall and operates a Coanda effect which confines the air flow into a virtual vertical tube along the wall to the floor.

[50] Because all the air sucked down from the top is confined along the wall directly to the floor, this air rises at mid-height of the room where the occupants breathe. This is exactly the solution for avoiding mutual contaminations of face to face interlocutors.

[51] According to a sub-option of this option, the invention also includes a heat exchanger and performs the function of air conditioning. This exchanger is also preferably a profiled component.

[52] According to an installation option of the invention, the invention is installed above the air inlet of a wall-mounted air conditioner.

[53] According to one embodiment of the invention a presence infrared pyroelectric detector switching off the UVC source when any one is detected in the emission field. It is also located on the focal line of the mirror. It interrupts the tube’s power supply by means of a relay controlled by a pyro-electric sensor when someone penetrates the upper room.

[54] The invention is optimized for its power. The UVC Intensity emitted over 360° is between 250 and 1000 uw I cm² at 2 meters in front of the projector, (approximately 10 times more than the state of the art). The UVC stratum is around 50 cm high at 5 m .

[55] A plastered or painted wall scatters about 60% UVC, which exceeds the acceptable standard by 5 for a continuous exposure of 8 hours in a room of 25-36 m² A powerful projector must be combined with a wall coating absorbing the UVC. This protects the occupants and the original colors of the painting or preexisting wall tapestry. (The windows glasses reflect horizontally but do not backscatter downwards). [56] The following table reports backscatter’s levels of UVC on several surfaces.

[57] 2mm micro-porous PTFE : 98%

[58] New plaster: 60%

[59] Old plaster 35%

[60] Wall paper 21 %

[61 ] Curtain velvet 4.5%

[62] White flocked polyethylene adhesive coating Only 3% .

[63] Aluminum, window or mirror (horizontal reflection only, not backscatter) negligible

[64] According to the invention the absorbent is a nonwoven fabric, velvet or a white felt for example. It is made of preferably nonflammable fiber such as PVC or polyester or polypropylene, coated with a removable adhesive. The best result is obtained with a white flocked vinyl covered by polyester flocked fibers..

[65] The incident UVC photons enter the flocked fabric with a direction substantially parallel with the direction of the fibers, they are trapped. After multiple reflections on said fibers they are absorbed at their roots. A flocked surface is trapping to light if the fiber’s material is not transparent. The polymers are not transparent to UVC. They absorb them or reflect them.

[66] Once combined with said powerful projector the flocked surface absorbs 20 times more the UVC light than a plaster wall. However, it scatters the light in the visible spectrum, and can be white. Thus, a UVC illumination 10 times stronger than the current art of Upper AIR UVC, once confined at the top of the walls covered with the said protective screen, exposes the occupants less than an illumination of nominal power directly on a plastered wall.

[67] Thus, an end user can install the said projector by himself and reduce the backscatter for its own sake and protect his walls from fading by applying the flocked liner.

[68] The invention therefore provides:

[69] An upper air germicidal light projector [70] characterized in that it projects a substantially horizontal thin layer of intense UVC light under the entire ceiling and on the top of all the walls of an occupied room 11 without leaking down to the occupants by means of:

[71] - a profiled concave parabolic mirror 31 , along an horizontal axis,

[72] - a profiled linear UVC light source 13 along said horizontal axis, located right bellow the focal line F of said mirror 31 ,

[73] - a profiled bended mirror 32 along said horizontal axis, surrounding said source 13 and orienting all said UVC light from said source 13 toward said mirror 31 ,

[74] - both said mirrors 31 and 32 being made of cold rolled aluminum sheets with their rolling and bending axis oriented along said horizontal axis,

[75] - a fixture securing the of the parabola of said parabolic mirror 31 , tangent to a wall, over the head’s level of the said occupants.

[76] characterized in that it illuminates a UVC absorbing screen 36 covering at least one of said walls.

[77] characterized in that said screen 36 is a flocked wall paper.

[78] characterized in that said source 13 is a mercury or amalgam vapor or excimer vapor tube

[79] characterized in that said source 13 is an array of UVC diodes and said means 32 is a mirror or an optical lens.

[80] characterized in that it comprises a tangential fan 35.

[81 ] characterized in that it provides an air conditioner by means of an integrated heat exchanger.

[82] characterized in that it comprises an infrared presence detector housed in the extension of the linear UVC light source, facing said mirror 31 , and whose reception angle is also confined by said mirror 32 .

Claims

[83] 1 ) An upper air germicidal light projector characterized in that it projects a substantially horizontal thin layer of intense UVC light under the entire ceiling and on the top of all the walls of an occupied room 11 without leaking down to the occupants by means of:

- a profiled concave parabolic mirror 31 , along an horizontal axis,

- a profiled linear UVC light source 13 along said horizontal axis, located right bellow the focal line F of said mirror 31 ,

- a profiled bended mirror 32 along said horizontal axis, surrounding said source 13 and orienting all said UVC light from said source 13 toward said mirror 31 ,

- both said mirrors 31 and 32 being made of cold rolled aluminum shits with their rolling and bending axis oriented along said horizontal axis,

- a fixture securing the top the parabola of said parabolic mirror 31 , tangent to a wall, over the head’s level of the said occupants.

[84] 2) An upper Air germicidal light projector according to claim 1 characterized in that it illuminates a UVC absorbing screen 36 covering at least one of said walls.

[85] 3) An upper Air germicidal light projector according to claim 2 characterized in that said screen 36 is a flocked wall paper.

[86] 4) An upper Air germicidal light projector according to claim 1 characterized in that said source 13 is a mercury or amalgam vapor or excimer vapor tube

[87] 5) An upper Air germicidal light projector according to claim 1 characterized in that said source 13 is an array of UVC diodes and said means 32 is a mirror or an optical lens.

[88] 6) An upper Air germicidal light projector according to claim 1 , characterized in that it comprises a tangential fan 35. [89] 7) An upper Air germicidal light projector according to claim 2 characterized in that it provides an air conditioner by means of an integrated heat exchanger.

[90] 8) An upper Air germicidal light projector according to claim 1 characterized in that it comprises an infrared presence detector housed in the extension of the linear UVC light source, facing said mirror 31 , and whose reception angle is also confined by said mirror 32 .