Uv disinfection cartridge system

Abstract

A box-shaped UV disinfection system (100) comprising: a plurality of internal UV sources (121, 122, 131, 132, 141, 142) disposed on at least two walls of the box-shaped UV disinfection system (100) adjacent to each other, all internal wall surfaces having a reflectivity higher than 80% and preferably higher than 87% in the wavelength range between 250 nm and 350 nm; and a UV-transmissive support (101) having a UV transmissivity of at least 70% in said wavelength range and located at a suitable minimum distance from said base wall (110), the UV sources (131, 132, 141, 142) disposed on at least one wall of the walls (130, 140) of the box-shaped UV disinfection system (100) are inclined towards the base wall (110) at an angle comprised between 5° and 30°. This system has improved characteristics in terms of efficiency and, in a preferred embodiment, also better portability.

Description

[0001] The present invention relates to a UV sterilization box system that has improved efficiency and, in a preferred embodiment, improved portability.

[0002] The use of UV radiation to disinfect items in compact form, such as "boxes" containing items to be disinfected, is very common and has been known for a long time, as described in German application DE3044181 or US application US20070274879, both of which use lamps as UV sources.

[0003] These devices have undergone continuous improvements, for example regarding preferred UV sources that exhibit primary emission in the so-called UV-C region, such as those described in International Application WO2021101431. This application describes achieving enhanced sterilization by combining UV sources with different UV wavelength emission spectra, more specifically a first UV source having a first wavelength range and a second UV source having a second wavelength range, wherein the first wavelength range has an upper limit extending upwards to at least 270 nm, and the second wavelength range has a lower limit extending downwards to at least 270 nm and an upper limit extending upwards to at least 320 nm. The patent application also discloses a range of UV sources suitable for UV disinfection boxes, such as low-pressure mercury lamps, UV LEDs, or UV chips. UV chips are less common than the other two types of sources, but are preferred because they are cold sources and do not require thermal shielding or systems for thermal management of the generated heat. Further details of this type of source can be found in International Application WO2018106168.

[0004] One aspect to consider when using UV sterilization boxes is maximizing the killing effect of the source on pathogens, especially when the purpose is to sterilize 3D objects (such as keys, mobile phones, wallets, ceramics and tableware, glasses, containers, pacifiers, bottles, toys, etc.) in order to minimize the number of sources used and / or sterilization processing time for cost-related reasons and / or for process efficiency. More sources and / or longer processing times have a negative impact on power management, and this is a thermal management issue for “hot” UV sources, as addressed by heat sinks in US patent application US20210085812, while for cold sources, there are issues to consider for systems not powered via a mains line, such as battery-operated systems or solar panel-assisted systems.

[0005] In addition, it is necessary to maximize the efficiency of the box while considering the impact on the objects to be sterilized. In fact, it is well known that repeated exposure to UV, especially UV-C, which is the most effective sterilizing radiation, will lead to the degradation of plastics: see, for example, the article “Damage to Common Healthcare Polymer Surfaces from UV Exposure” by Peter Teska et al. published in Nano LIFE, Vol. 10, No. 3, 2020, or the paper “Ultraviolet light accelerates the degradation of polyethylene plastics” by Mustafa Dogan published in Microsc. Res. Tech., Nov. 2021; 84(11): 2774-2783.

[0006] The purpose of this invention is to provide a novel UV box system that offers improved performance compared to existing UV box systems, particularly in terms of the placement and effectiveness of the UV sources used. This invention relates to a UV sterilization box system having at least one movable wall, wherein all inner wall surfaces of the UV box have a reflectivity greater than 80%, and preferably greater than 87%, in the wavelength range between 250 nm and 350 nm. The UV sterilization box system includes a plurality of discrete UV sources disposed within the UV box on at least two adjacent walls, and absent on at least one UV box wall. The UV box also includes an internal UV transmission support having a UV transmittance of at least 70%, disposed at a minimum distance d1 from the base wall and a maximum distance d2 from the opposite upper wall, wherein 0.1 ≤ d1 / (d1+d2) < 0.5, preferably 0.15 ≤ d1 / (d1+d2) ≤ 0.4.

[0007] Examples of such a UV disinfection box system described in the preamble of claim 1 can be found in US 2013 / 078142 and US 2008 / 265179. The present invention differs from US 2013 / 078142 and US 2008 / 265179 in that discrete UV sources disposed on at least one wall of the wall are inclined toward the base wall at an angle including between 5° and 30°.

[0008] As will be apparent from the following description and illustrative representation of preferred embodiments, the term "adjacent wall" means and is interpreted as a wall having a shared boundary.

[0009] The preferred method for characterizing UV reflectance and UV transmittance is by means of integrating sphere measurement: as outlined by Shimadzu in his Talk letter, Volume 5, Summer 2010, this also allows for a proper assessment of the contribution of so-called diffuse reflectance.

[0010] The inventors have discovered that, utilizing the above-described solution, due to the synergistic effect of all the aforementioned components, even if one or more of the box walls lack discrete UV sources (in a preferred embodiment, one of the box walls without a UV source is its base), all surfaces of objects placed in the box can be irradiated with sufficiently high UV irradiance. This allows a single disinfection cycle to typically last from 30 seconds to 6 minutes, most typically from 40 seconds to 3 minutes, thereby achieving adequate disinfection with low electrical energy on all object surfaces exposed to the internal volume V, including surfaces not directly facing discrete UV sources, achieving a pathogen inactivation level of at least 99.9%.

[0011] Suitable UV sources are UV-C LEDs, UV chips, such as those described in the aforementioned international application WO2018106168, and other UV-C mercury-free lamps, such as UV excimer lamps. The use of UV chips is preferred because they provide strong inactivation against bacteria and viruses due to their specific spectrum of continuous emission between 250 nm and 320 nm, with a first peak in the range of 260 nm to 280 nm and a second peak in the region of 290 nm to 310 nm, wherein the dominant intensity peak is at approximately 265 nm. A single discrete UV source emitting UV radiation having the first and second spectral emission peaks can be used, or a first discrete UV source emitting radiation centered on the first peak and a second discrete UV source emitting radiation centered on the second peak can be used.

[0012] The present invention will be further illustrated by the following figures, in which:

[0013] ·· Figure 1 This is a schematic diagram of a first embodiment of a UV box according to the present invention;

[0014] ·· Figure 2 This is a schematic diagram of the second embodiment;

[0015] ·· Figure 3 It is in an "expanded" configuration. Figure 1 A top view of the first embodiment shown in the diagram;

[0016] ·· Figure 4 A to Figure 4E shows two schematic diagrams of the UV box configuration according to the present invention and three comparative examples tested and illustrated herein;

[0017] ·· Figure 5A A schematic diagram of the interior of the UV box is shown, while Figure 5B and Figure 5C It is an enlarged view of a detail within a detail; and

[0018] ·· Figure 6 Similar to the alternative implementation shown Figures 5A to 5C A schematic diagram of the interior of the UV box.

[0019] In the figures above, the dimensions and aspect ratios of the components are not always accurate. In some cases, they have been modified to improve their understanding, specifically and non-exclusively referring to the wall thickness and dimensions of the UV source relative to the box wall dimensions. Furthermore, components unnecessary for understanding the figures and to the common sense of those skilled in the art, such as electrical connections to the source, electronic components, and drive units, are not shown.

[0020] According to the schematic diagram of the UV box 100 in the first embodiment, Figure 1 The UV box is shown as having three pairs of discrete UV sources disposed on the inner surfaces of three walls: UV sources 131 and 132 disposed on side wall 130; UV sources 141 and 142 disposed on opposite side wall 140; and UV sources 121 and 122 disposed on upper wall 120. The other three UV box walls, namely front wall 150, base wall 110, and rear wall (not shown), do not have discrete UV sources mounted thereon, and the UV box is shown as "open," with front wall 150 connected only to base wall 110.

[0021] A UV transmission support 101 exists between the base wall 110 and the upper wall 120. The positioning of this UV transmission support 101 is crucial to ensuring effective irradiation from below the object to be disinfected. This positioning is defined by the aforementioned expression 0.1 ≤ d1 / (d1+d2) < 0.5, meaning it should be between 10% and 50% of the distance between the base wall 110 and the upper wall 120 (i.e., the UV box height). This condition indicates that the UV transmission support 101 needs to be at a certain and appropriate distance relative to the base wall 110. In this respect, d1 represents the minimum distance between the support 101 and the base wall 110 when the support 101 is inclined and / or does not have a flat shape, and d2 represents the maximum distance between the support 101 and the upper wall 120 when the support 101 and / or the upper wall 120 are inclined and / or do not have a flat shape.

[0022] like Figure 1As shown, the front wall 150 preferably does not contain a UV source because the front wall 150 needs to be shifted / moved to open / close the UV box 100, since the presence of a UV source would impose some limitations on its power supply. Discrete UV sources 121, 122 emit UV radiation, the principal components of which are orthogonal to the wall on which the discrete UV sources 121, 122 are mounted, and have an angular emission distribution of 100° for a standard UV chip and 120° to 130° for a standard UV LED.

[0023] UV sources 131 and 132 disposed on the first sidewall 130 and UV sources 141 and 142 disposed on the opposite sidewall 140 are mounted at a certain downward inclination—the downward inclination being between 5° and 30°—such that their main emission is not perpendicular to the mounting walls 130 and 140, but forms a smaller angle between 85° and 60°, i.e., oriented toward the base wall 110.

[0024] It should be noted that not all discrete UV sources need to have “tilted” emission toward the base wall 110, but at least all UV sources mounted on the wall, preferably the side wall, should meet this requirement. More preferably, except for those UV sources mounted on the upper wall 120, all discrete UV sources have tilted emission toward the base wall 110.

[0025] Alternative methods for achieving tilted UV emission in Figure 2 A second embodiment is shown, outlining the structure of the UV box 200. Due to the trapezoidal cross-sectional shape of the UV box, it has inwardly inclined sidewalls 230 and 240, and an upper wall 220 smaller than the base wall 210. Although all UV sources 221, 222, 223 and 241, 242, 243 are mounted parallel to walls 220 and 240 respectively (i.e., the main emission direction is perpendicular to their mounting walls), for UV sources 241, 242, 243, the main emission is inclined towards the base wall 210 due to the inclination of the sidewall 240. The inclination angle of the sidewalls carrying the UV sources relative to the base wall 210 includes between 60° and 85°.

[0026] Although the preferred configuration is Figure 2 The sidewall 230 shown is a mirror image of the sidewall 240 that carries the discrete UV source. However, the sidewall 230 can also be perpendicular to the base wall 210, as in the first embodiment, when the sidewall 240 meets the tilting requirements of the present invention. Alternatively, the sidewall 230 can even be tilted outward if this is useful for proper reflection of UV radiation (in which case the cross-section will be more similar to a parallelogram).

[0027] It is important to emphasize that the UV box of the present invention is not limited to a specific number of UV sources or a specific placement on the box walls, as long as they satisfy the more general requirements expressed in claim 1. Nevertheless, a preferred configuration envisions the use of six discrete UV sources, which in one case are evenly distributed on three walls, with two sources on each wall (e.g., Figure 1 In the implementation method as described above), or alternatively, evenly distributed on the two walls, with three sources on each wall (as described above). Figure 2 (as in the implementation). The second preferred configuration envisions using four discrete UV sources distributed on the three walls, most preferably two sources on the upper wall and one source on each side wall.

[0028] Regarding the power of this UV source, the most efficient and low-power systems have a power rating of 0.25 mW / cm². 3 With 0.60mW / cm 3 The ratio of the cumulative electrical power P of the discrete UV sources to the internal volume V.

[0029] All UV boxes according to the invention can be made of a rigid structure, and all UV boxes have only a movable panel for opening and closing the box; alternatively, all UV boxes can be made of foldable / connectable panels, such as... Figure 3 as exemplified in Figure 3 It shows Figure 1 The image shows a top view of the assembled UV box 100 in its unfolded state. As described above, UV sources 131 and 132 are mounted on box panel 130 (first sidewall), UV sources 141 and 142 are mounted on box panel 140 (second sidewall), and UV sources 121 and 122 are mounted on box panel 120 (upper wall). Panels 110 (base wall), 150 (front wall), and 160 (rear wall) do not have UV sources. Electrical connections between the UV sources and the electronic control components and electric drive unit can be arranged on the panels or embedded in the panels.

[0030] As shown in the exemplary embodiment of FIG5, electronic control components and power drive units (and any other electrical or logic elements) may be located in container 511, the upper surface of which is the base 510 of UV box 500, or container 511 may alternatively be attached to the base of UV box.

[0031] Figure 3The diagram shows panels already connected so that the box can be folded into an assembled state. However, the panels can be completely separated and connected together via suitable adhesive strips, hinges, or alternatively, the panels can have semi-permanent connections so that after the initial assembly, the box walls do not need to be completely separated, but the panels can be folded. When the panels are unfolded, a compact and small structure is obtained, making the system easy to store or transport and easy to reassemble for operation. Preferably, the ratio between its internal volume V and the volume of the unfolded box is in the range of 4 to 16. The UV discrete sources 131, 132, 141, 142, indicated by black circles, are inclined relative to the mounting walls 130, 140, while the UV discrete sources 121, 122, indicated by white circles, are mounted parallel to wall 120, because once assembled, wall 120 will be the upper wall of the UV box.

[0032] In the case of a UV box with separable walls, these walls can be stored in a suitable container that also houses the electronic modules and their components. In this regard, the preferred solution is the container 511 of Figure 5.

[0033] A common feature of all UV box embodiments according to the present invention is the high reflectivity of the inner surface of the UV box wall (i.e., the surface of the wall facing the internal volume V), more specifically, in the wavelength range between 250 nm and 350 nm, this reflectivity should be >80%, and preferably >87%.

[0034] Suitable materials for the inner surface of UV boxes are porous fluoropolymer layers, particularly expanded PTFE (e-PTFE) or porous PTFE, especially Porex Virtek. TM (Provided by Porex Corp.), the Porex Virtek TMThe average UV reflectance is 94% for a 0.75mm thick layer and 91% for a 0.5mm thick layer. Special UV-reflective aluminum layers also have suitable high UV reflectance (equal to or greater than 90%), such as Alanod's UV-C Miro aluminum reflector with a UV reflectance greater than 90%, or Almeco's Vega UV-C aluminum surface with a nano PVD layer with a UV reflectance greater than 91%. The above solutions allow for higher UV reflectivity, which is a crucial aspect of minimizing the number of UV sources. In this regard, it is important to emphasize that standard UV boxes typically use standard Al reflective layers, achieving UV reflectivity up to 75%, as illustrated in the historical reference "Ultra-violet reflecting power of Aluminum and several other metals" by William Weber Coblentz et al., Vol. 4, p. 189 of the Bureau of Standards Journal of Research, or the more recent paper "Laser-based Surface Modifications of Aluminum and its Alloys" by MMQuazi et al., Critical Reviews in Solid State and Materials Sciences, 2015, 0:1-26, pp. 1-26. (Specific references are not provided in the original text.) Figure 1 .

[0035] Disinfection devices based on external light emission, such as those described in US Application US20080253941, or lighting systems with disinfection as an additional feature, such as those described in US Application US20160215941 and International Application WO2011049859, rely on the opposite mechanism (light emission) to achieve disinfection. Another possibility, as described in Indian Application IN202011020635, is to achieve complete exposure of objects to UV radiation through the movement / rotation of a UV source.

[0036] Another common feature shared by all UV box embodiments according to the present invention is the UV transmission characteristics of the support for the object to be sterilized, which should be at least 70% in the range of 250 nm to 350 nm. As already outlined regarding the reflectivity of the UV box wall, the transmittance can also be characterized by means of an integrating sphere.

[0037] This effect can be achieved by using UV-transparent materials, such as thin fluoropolymer sheets (typically ranging from 120 μm to 300 μm in thickness) with good UV transmission properties, such as UV-transparent fluoropolymers like THV (a polymer of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride) or ETFE (ethylene tetrafluoroethylene). Using these exemplary materials, UV transmittance of the support element can be achieved above 70%; for example, a 0.18 mm thick THV support element has a UV transmittance above 75%.

[0038] Special UV-transmitting synthetic glass sheets can also be used effectively, but they are less preferred because they are generally more brittle and more sensitive to mechanical shock. An alternative solution is to use a mesh structure with a void fill ratio ranging from 3 to 200.

[0039] The support element can be a freestanding component supported by a suitable pillar of appropriate height, or it can be a flat component inserted into a suitable recess in the internal structure of the box; alternatively, the support element is hinged to the side wall so that it can be folded for use in a box made of foldable / separable panels. In this case, it is also conceivable to have two half-width support elements, each hinged to the wall, such that the assembly of the UV box results in the support element being formed by joining the two half-width support elements together.

[0040] Another preferred solution for the support is illustrated in Figure 5, which shows a perspective view of a UV box 500 with the front and right panels removed. The UV box 500 has a container 511 connected to or forming the base wall 510. UV sources 521, 522, 531, and 532 are respectively disposed on two adjacent walls, namely the top wall 520 and the side wall 53. The bottom container 511 includes UV box electronics, controls, and a power supply (not shown). In the UV box 500, the support is made of a series of liftable elongated transverse elements (bars) 501, 501', 501”, and 501”’ rotatably mounted on the base wall 510, each of which has a conventional system (not shown) for locking / unlocking them in place on the base wall 510.

[0041] Figure 5B The single liftable element 501 is shown in detail in its two positions: the "rest" position indicated by the dashed line and the lifted position indicated by the solid line.

[0042] It should be emphasized that this invention is not limited to any number of liftable elements, or a particular material or shape, or a lateral arrangement. Regarding the shape of the liftable rod, in... Figure 5CAn interesting variation is shown in the partial front view, in which the support 5010 has a recess 5011 that helps prevent the rolling of cylindrical objects with narrow dimensions, such as thermometers.

[0043] All liftable elements can be controlled individually or alternately, i.e., raised or lowered. The liftable elements can be connected such that raising or lowering just one liftable element, preferably the most easily accessible one, such as the one closer to the open wall, will cause the other liftable elements to also move to the raised or lowered position. For example, such as... Figure 6 As shown in the perspective view, the UV box 600 has four liftable rods 601, 601', 601”, 601”', which are connected together in any suitable manner by means of a connecting rod 6010 that is rotatably fixed to the rod.

[0044] Finally, it should be emphasized that, in this embodiment, the distance between the support and the base wall and upper wall of the UV box is measured from the lifted element portion, which defines the resting plane of one or more objects to be treated with UV radiation.

[0045] In a preferred embodiment, the UV box is powered by a rechargeable battery; in the most suitable variant, it is powered by one or more solar panels mounted on the outer surface of the UV box wall. Optionally, a charge controller can be used to optimize the charging and discharging cycles.

[0046] The battery and any drive or control electronics with switches and user interface panels can be components that can be separated from the UV box, or more preferably permanently connected to the UV box. In the case of foldable or assemblable UV boxes, permanent connection to the UV box is preferred.

[0047] An optional element advantageously present in the UV box according to the invention is a safety interlock switch for cutting off the UV source when the box is opened, thereby preventing power from being supplied to the box if it is not properly assembled or if it is accidentally opened during the sterilization process. Additionally, a UV sensor or exposure meter may also be present, even if they are not highly relevant.

[0048] The invention, its principles, and advantages will be further illustrated by the following non-limiting examples.

[0049] Example 1

[0050] Photometric measurements were performed to determine the UV irradiance generated inside a foldable UV system, which is cuboid in shape and has a disinfection volume of approximately 30cm × 15cm × 15cm (L × W × H). Figure 1 The configuration shown indicates that the system is equipped with a power supply of 3W cumulative electrical power P (P / V = 0.44mW / cm). 3 The device contains six UV sources. The walls are coated with a 0.75mm thick layer of highly UV-reflective porous PTFE (Porex Virtek). TM The UV source is a UV chip manufactured by LightLab Sweden AB, each chip having a UV output power of 10mW and producing radiation with an emission peak centered at 265nm and a second, lower peak centered at 305nm. The UV irradiance within the sterilization volume is measured using a UV sensor module UVM-30A connected to a suitable acquisition system, which is adapted to have good responsivity in the 200nm to 370nm range and is calibrated.

[0051] With the sensor pointing upwards towards the UV source, the UV irradiance measured in the central region of the system at a height of approximately 4 cm from the base exceeds 140 μW / cm². 2 The UV irradiance values ​​were also measured in the central region of the UV box by positioning the sensor on a 180 μm thick UV-transmitting THV support, with the sensor's sensitive area facing the box base, i.e., towards the surface where no active UV is generated. This arrangement reflects that the surface of the 3D object is not exposed to direct UV radiation, but only to UV radiation that impacts it via (multiple) reflections onto the highly reflective inner surface of the wall.

[0052] Table 1 below reports the average UV irradiance measured at different distances from the base to the support, and the same UV irradiance relative to the highest measured value (116 μW / cm). 2 Normalized relative values:

[0053]

[0054] Table 1

[0055] It can be observed that a relative UV irradiance higher than 70 can only be achieved within the distance range specified in this invention, i.e., within a distance range of 0.1 ≤ d1 / (d1+d2) < 0.5. This value is limited to the threshold of an effective UV box system, because a lower value would result in insufficient disinfection effect from reflected radiation. It can also be observed that the UV system according to the preferred embodiment, i.e., the UV system with 0.15 ≤ d1 / (d1+d2) ≤ 0.4, has improved efficiency; more specifically, the relative UV irradiance is much higher than 85.

[0056] Example 2

[0057] Photometric measurements were performed to determine the UV irradiance generated inside the same foldable UV system, which has the cuboid shape and dimensions described in Example 1, but with features as described in... Figure 4 The different UV source placements are shown in the UV system schematic diagrams C1, C2, S1, C3, and S2 in sections A to 4E.

[0058] •A) Comparative Example C1: Six UV sources are placed at equal distances from each other on a single wall, i.e. the upper wall of the UV system, and the main component of the emitted UV radiation is orthogonal to both the mounting wall surface and the base of the box.

[0059] •B) Comparison Example C2: Install three UV sources from two series on two adjacent walls, namely the side wall and the top wall, and achieve equidistant positioning of the UV sources with the wall edges in the middle region. In this case, the main UV radiation is also orthogonal to the mounting wall.

[0060] • C) Sample S1: The position of the UV source is the same as that of comparative example C2, but the UV source is mounted on the side wall at a 10° angle toward the base wall;

[0061] •D) Comparison Example C3: In this case, two UV sources from three series are mounted on three walls, namely the top wall and two adjacent side walls, and in each wall, the UV sources are equidistant from each other and mounted in the middle region of the wall, and the main emission of the UV sources is orthogonal to the mounting wall.

[0062] •E) Sample S2: The position of the UV source is the same as that of comparative example C3, but the UV source is mounted on the side wall at a 20° angle toward the base wall.

[0063] The UV irradiance inside the system is measured using the same UV sensor module UVM-30A in the same manner as in Example 1. UV irradiance is also measured by rotating the sensor 90° so that it faces the rear wall and then the side wall where no UV source is present, except in configurations D) and E), where the UV source is present on both side walls but not directly in front of the sensor. In configurations B) and C), additional UV measurements are performed by placing the UV sensor 3.5 cm from the side wall without a UV source, or 3.5 cm from any side wall in configurations D) and E).

[0064] The average relative UV irradiance measured under different configurations (normalized to the highest value) is reported in Table 2 below.

[0065]

[0066]

[0067] Table 2

[0068] As can be seen from the relative values ​​above, the configuration with sources on multiple walls is superior to the configuration with a single wall (comparison example C1), as the configuration with sources on multiple walls has a more uniform distribution of reflected radiation in all directions. Additionally, it must be noted that when the object to be disinfected is large, installing a UV source on a single wall will result in a large shadow effect caused by the object, which will significantly reduce reflected radiation.

[0069] Furthermore, configurations with sources distributed on more walls (such as the three walls in D and E) are superior to configurations with sources distributed on fewer walls (such as the two walls in B and C), and in any case, tilting the UV sources on the side walls to create an angle of 70° to 80° between their main emission directions and the main emission direction from the UV source mounted on the upper wall is suitable for increasing the intensity of reflected radiation. Indeed, as a direct comparison between results obtained with the same type of configuration shows, comparative example C2 is worse than sample S1, and comparative example C3 is worse than sample S2.

[0070] It has been found that for angles less than 60°, i.e., UV sources mounted on the sidewalls with a tilt greater than 30° toward the base, the additional advantage of reflected radiation is not significant.

[0071] Example 3

[0072] Additional photometric measurements were performed using the UV system configuration of sample S1 with different reflective coatings:

[0073] a) An aluminum reflective sheet with an average reflectivity of nearly 90% in the UV region;

[0074] b) A 0.75mm thick porous PTFE layer (Porex Virtek) TM (Thin film), in which the average reflectance in the UV region is 94%.

[0075] UV irradiance was measured as in Example 1, and the average relative UV irradiance of coating a) was 7% lower than that of coating b).

[0076] Therefore, the optimal coating is represented by a 0.75 mm thick highly reflective porous PTFE, and the preferred coating thickness includes the range of 0.20 mm to 1.50 mm.

[0077] It has been proven that high-purity (>99.9%) metal coatings with a thickness of up to 500 nm, for example, produced by sputtering, are suitable for improving the UV reflectivity of aluminum; Al and Ag are preferred metals for this purpose and effect.

[0078] Example 4

[0079] A system manufactured according to a second embodiment of the invention, specifically a sample S3 having a trapezoidal cross-section—the base wall dimensions of sample S3 being 22 cm × 30 cm, the upper wall dimensions being 15 cm × 30 cm, and the height being approximately 14 cm—has been evaluated. This system was compared with a commercially available system whose UV source is only on the upper wall and whose standard Al surface reflectance is <80%. The main characteristics of the S3 system and the commercially available system, as well as the comparative samples C4 to C6, are shown in Table 3 below, while their performance in terms of the time required to achieve a 99.9% disinfection level is reported in Table 4 below.

[0080]

[0081] Table 3

[0082] S3 <2min C4 3min C5 3min C6 8min

[0083] Table 4

[0084] It can be observed that the system according to the invention is not only the fastest system, but also requires less than half the cumulative power of a system of the same size (C5) even with the largest internal volume, thus making it the most efficient system with the lowest power per unit volume (P / V) ratio.

[0085] The above examples each studied the effects of specific features of the UV box of the present invention, and even their simultaneous existence and synergistic effect resulted in the UV disinfection box system having enhanced characteristics compared to the prior art UV disinfection box system.

Claims

1. A box-shaped UV disinfection system (100; 200; 500; 600), said box-shaped UV disinfection system (100; 200; 500; 600) having at least one movable wall (150) and comprising: Multiple discrete UV sources (121, 122, 131, 132, 141, 142; 221, 222, 223, 241, 242, 243; 521, 522, 531, 532) are provided in the box-shaped UV disinfection system, but are not present on at least one wall of the system. And internal UV transmission supports (101; 201; 501, 501', 501'', 501'''; 601, 601', 601”, 601”'), wherein all inner wall surfaces are at 250 nm and 350 nm. The discrete UV sources (121, 122, 131, 132, 141, 142; 221, 222, 223, 241, 242, 243; 521, 522, 531, 532) are disposed on at least two adjacent walls of the wall (110, 120, 130, 140, 150, 160; 210, 220, 230, 240; 510, 520, 530) of the box-shaped UV disinfection system, and the UV transmission support (101; 201; 501, 501', 501'', 501'''; 601, 601', 601" , 601''') has a reflectivity higher than 80% in the wavelength range between 250 nm and 350 nm. Having at least 70% UV transmittance in the wavelength range between nm, and positioned at a minimum distance d1 from the base wall (110; 210; 510) and a maximum distance d2 from the opposite upper wall (120; 220; 520) such that 0.1 ≤ d1 / (d1+d2) < 0.5, characterized in that the discrete UV sources (131, 132, 141, 142; 241, 242, 243; 531, 532) disposed on at least one of the walls (130, 140; 240; 530) are tilted toward the base wall (110; 210; 510) at an angle including between 5° and 30°.

2. The box-shaped UV disinfection system (100; 200; 500; 600) according to claim 1, wherein, The reflectivity is higher than 87%.

3. The box-shaped UV disinfection system (100; 200; 500; 600) according to claim 1, wherein, 0.15≤d1 / (d1+d2)≤0.

4.

4. The box-shaped UV disinfection system (100; 200; 500; 600) according to any one of claims 1 to 3, wherein, The at least one wall without a discrete UV source is either the base wall (110; 210; 510) or the displaceable wall (150).

5. The box-shaped UV disinfection system (100; 200) according to any one of claims 1 to 3, wherein, The UV transmission support (101; 201) is held on at least two different walls (130, 140; 230, 240) or by a support that contacts the base wall (110; 210).

6. The box-shaped UV disinfection system (100; 200) according to any one of claims 5, wherein, The UV transmission support (101; 201) is held on two opposing walls.

7. The box-shaped UV disinfection system (100; 200) according to any one of claims 1 to 3, wherein, The UV transmission support (101; 201) is a mesh structure having a void fill ratio between 3 and 200.

8. The box-shaped UV disinfection system (100; 200) according to any one of claims 1 to 3, wherein, The UV-transmitting support (101; 201) is made of UV-transparent material.

9. The box-shaped UV disinfection system (100; 200) according to claim 8, wherein, The UV transparent material is selected from the terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride, ethylene tetrafluoroethylene, and UV transmission synthetic glass.

10. The box-shaped UV disinfection system (500; 600) according to any one of claims 1 to 3, wherein, The UV transmission support includes a series of parallel liftable elements (501, 501', 501”, 501'''; 601, 601', 601”, 601'''), which are rotatably mounted on the base wall (510) and connected by a connecting element (6010) such that all of the parallel liftable elements (501, 501', 501”, 501'''; 601, 601', 601”, 601''') can be raised or lowered by acting on only one of the parallel liftable elements.

11. The box-shaped UV disinfection system (100; 200; 500; 600) according to any one of claims 1 to 3, wherein, The inner wall surface is made of porous PTFE or an aluminum layer with a metal nano-coating, or the inner wall surface is coated with porous PTFE or an aluminum layer with a metal nano-coating.

12. The box-shaped UV disinfection system (100; 200; 500; 600) according to claim 11, wherein, The metal is selected from high-purity Al or Ag.

13. The box-shaped UV disinfection system (100) according to any one of claims 1 to 3, wherein, The tilt angle of the discrete UV sources (131, 132, 141, 142) is obtained by tilting the discrete UV sources (131, 132, 141, 142) relative to the wall on which the discrete UV sources (131, 132, 141, 142) are mounted.

14. The box-shaped UV disinfection system (200) according to any one of claims 1 to 3, wherein, The tilt of the discrete UV sources (241, 242, 243) is obtained by tilting the sidewall (240) on which the discrete UV sources (241, 242, 243) are mounted.

15. The box-shaped UV disinfection system (200) according to claim 14, wherein, The box has a trapezoidal cross-sectional shape.

16. The box-shaped UV disinfection system (100; 200; 500; 600) according to any one of claims 1 to 3, wherein, The box-shaped UV disinfection system (100; 200; 500; 600) includes a 2000 cm 3 With 14000 cm 3 The internal volume V between the discrete UV sources (121, 122, 131, 132, 141, 142; 221, 222, 223, 241, 242, 243; 521, 522, 531, 532) is included in the ratio of the cumulative electrical power P to the internal volume V, which is 0.25 mW / cm². 3 With 0.60 mW / cm 3 between.

17. The box-shaped UV disinfection system (100; 200; 500; 600) according to claim 16, wherein, The internal volume V includes 4000 cm³ 3 With 9500 cm 3 between.

18. The box-shaped UV disinfection system (100; 200; 500; 600) according to any one of claims 1 to 3, wherein, The discrete UV sources (121, 122, 131, 132, 141, 142; 221, 222, 223, 241, 242, 243; 521, 522, 531, 532) are UV-C LEDs or chips with spectral emission having a first peak in the range of 260 nm to 280 nm and a second peak in the range of 290 nm to 310 nm.

19. The box-shaped UV disinfection system (100; 200; 500; 600) according to claim 18, wherein, The discrete UV sources (121, 122, 131, 132, 141, 142; 221, 222, 223, 241, 242, 243; 521, 522, 531, 532) emit UV radiation having both the first peak value and the second peak value, or UV radiation centered on the first peak value or UV radiation centered on the second peak value.

20. The box-shaped UV disinfection system (100; 200; 500; 600) according to any one of claims 1 to 3, wherein, The number of discrete UV sources (121, 122, 131, 132, 141, 142; 221, 222, 223, 241, 242, 243) is six, and they are evenly distributed on two or three walls.

21. The box-shaped UV disinfection system (100; 200; 500; 600) according to any one of claims 1 to 3, wherein, The walls are connected in such a way that the box can be unfolded, and the ratio between the internal volume V of the box and the volume of the unfolded box is in the range of 4 to 16.

22. The box-shaped UV disinfection system (100; 200; 500; 600) according to any one of claims 1 to 3, wherein, The box-shaped UV disinfection system (100; 200; 500; 600) also includes a solar panel on the outer surface of at least one of the walls, the solar panel being connected to an energy storage rechargeable battery, the energy storage rechargeable battery being combined with a charging controller.

23. The box-shaped UV disinfection system (100; 200; 500; 600) according to any one of claims 1 to 3, wherein, The box-shaped UV disinfection system (100; 200; 500; 600) also includes a separate power supply module adapted to be connected to the discrete UV sources (121, 122, 131, 132, 141, 142; 221, 222, 223, 241, 242, 243; 521, 522, 531, 532).

24. The box-shaped UV disinfection system (100; 200; 500; 600) according to any one of claims 1 to 3, wherein, The power modules and other electronic components for the discrete UV sources (121, 122, 131, 132, 141, 142; 221, 222, 223, 241, 242, 243; 521, 522, 531, 532) are embedded in a system with an internal volume V.

25. The box-shaped UV disinfection system (500) according to claim 24, wherein, The power module and other electronic components are housed in a container (511), which is connected to or forms the base wall (510).

26. The box-shaped UV disinfection system (100; 200; 500; 600) according to any one of claims 1 to 3, wherein, The box-shaped UV disinfection system (100; 200; 500; 600) further includes one or more safety interlock switches, which are adapted to cut off the power supply to the discrete UV sources (121, 122, 131, 132, 141, 142; 221, 222, 231, 232, 241, 242, 243; 521, 522, 531, 532) when the box is opened or to prevent power supply to the discrete UV sources (121, 122, 131, 132, 141, 142; 221, 222, 231, 232, 241, 242, 243; 521, 522, 531, 532) in the event that the box is not properly assembled.

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