CN111320230A - Device for sterilizing fluids - Google Patents

Abstract

The present invention relates to a device (1, 1', 1", 1"', 1"") for sterilizing a fluid and a method for its manufacture, the device comprising: a container (2, 2', 2") for containing the fluid , 2"', 2"") having an outer wall (12) surrounding the inner cavity (24); and a light source (8) having at least one LED (8a-8k, 8n) arranged to convert wavelengths in the UV Light in the radiation range is emitted via the outer wall ( 12 ) of the container or from a corresponding position in the vicinity of the outer wall with a radiation characteristic into the inner cavity of the container in order to illuminate the fluid contained in the inner cavity. The surface (14) of the outer wall (12) facing the inner cavity (24) has a shape in at least one subsection (18, 20, 32, 48) that substantially matches the radiation characteristics of the light emitted into the inner cavity (24) . The shape of the surface (14) preferably substantially matches the iso-intensity surface (I1, I2, I3, I4) or envelope (44) of the beam of light emitted by the light source (8) into the lumen.

Description

Device for sterilizing fluids

technical field

The present invention relates to a device for sterilizing fluids, comprising: a container for containing the fluid, the container having an outer wall surrounding an inner cavity; and a light source comprising at least one LED (Light Emitting Diode), which is provided for, Light with a wavelength in the UV (ultraviolet) radiation range, preferably in the UV-C (short-wave ultraviolet) radiation range, is emitted into the inner cavity of the container via the outer wall of the container or from a corresponding position in the vicinity of the outer wall, so that the radiation is contained in the container. fluid in the lumen. Such devices are also known as UV reactors.

Background technique

It is known that UV reactors are used for preparing drinking water or for sterilizing or disinfecting wash water in dishwashers or the like. Microorganisms, in particular viruses, bacteria or fungi, contained therein can be inactivated by UV radiation acting on the fluid. In this case, the corresponding germs are directly killed by UV radiation or at least damage their DNA and thus prevent their replication. Particularly effective here is radiation in the wavelength range from 200 nm to 280 nm, which is also referred to as far-ultraviolet (FUV) radiation according to standard DIN 5031-7. Also obtained is associated therewith the radiation in the range of 100 nm to 200 nm, the radiation of which is correspondingly referred to as vacuum ultraviolet (VUV) radiation.

Furthermore, UV radiation in the range of 249 nm to 338 nm acts against bacteria on the biofilm, with a particularly high effectiveness in the wavelength range between 292 nm and 306 nm, which has the greatest effect at 296 nm. Biofilms within the scope of this application include non-liquid fluids. Radiation with this wavelength is absorbed in the atmosphere, so that most microorganisms are not resistant to it. DNA in particular absorbs radiation at most between about 260 nm and 270 nm.

Radiation in the wavelength range up to 280 nm explained above is summarized in this application as UV-C radiation, radiation in the range from 280 nm to 315 nm is summarized as UV-B radiation, and radiation in the range from 315 nm to 380 nm is summarized as UV-B radiation It is UV-A radiation, and most of these radiations are used in UV reactors. For the purposes of this application, the concept UV-C radiation as applied here also includes the range from 10 nm to 121 nm (extreme ultraviolet).

Radiation-emitting LEDs can also be used in the UV-C wavelength range to disinfect or sterilize fluids. Here, LEDs are made of materials whose band gap (transmission in wavelength) falls within the range of UV-C radiation, such as aluminum gallium nitride (AlGaN; including AlN: 6.1 eV and GaN: 3.45 eV, i.e. from From about 210nm), or hexagonal boron nitride (hBN; 5.8eV, that is, about 215nm), etc. However, the efficiency of the LEDs in the UV-C range (radiation emitted per energy use) is still lower than that of conventional mercury low-pressure lamps during the duration of operation, which can exceed 10,000 hours. In addition, the efficiency is also dramatically reduced with respect to shorter and shorter wavelengths, yet another improvement is achieved here.

Therefore, when sterilizing with LEDs, it is just necessary to irradiate as efficiently as possible the lumen in the reactor through which the fluid to be sterilized flows (or contains the fluid). In general, the aforementioned states are only achieved with high overhead when using a plurality of intensely illuminating LEDs arranged on different sides of the respective container. For example, flow reactor geometries typically have simple circular cross-sections or regular polygonal cross-sections (eg, squares). Therefore, taking into account additional light refraction in the light that is usually incident from the outside, a small amount of microenvironments can be created in the inner cavity, which are ultimately not irradiated by UV radiation or are only weakly and thus insufficiently affected by UV radiation. UV radiation exposure. Thus, germs or biofilms can exist just there.

As a measure to prevent the formation of niches, optical elements can be used which distribute the radiation in the interior of the container in a suitable manner. For example, a lens can expand incident radiation. Alternatively, a mirror, usually formed by a reflective wall opposite the LED, can be applied, eg coated with a suitable material. The internal reflector surface can then reflect incident radiation or generally backscatter light just also in the direction of the niche.

However, on the one hand this measure can be very expensive and on the other hand a complex radiation field can be formed, which also depends on the transmittance of the relevant fluid. Therefore, the production of germs or the production of biofilm niches cannot be prevented at all times, thereby mixing sterilized and unsterilized fluids.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a device for sterilizing fluids in which the formation of unirradiated niches is avoided and, instead, adequate irradiation through a complete cross-section of the lumen is ensured. Another object is to provide a corresponding method.

This object is achieved by a device for sterilizing fluids and a corresponding method.

A device for sterilizing a fluid is first proposed, comprising a container for containing the fluid, wherein the container has an outer wall surrounding an inner cavity. The vessel can here be a flow reactor as a UV reactor or a refillable tank. In the case of a refillable tank, fluid can be first filled and then drained during sterilization in the container.

Furthermore, a light source comprising at least one LED is provided. The light source is designed to emit light with a wavelength in the UV radiation range via the outer wall of the container or from a corresponding position in the vicinity of the outer wall with a radiation characteristic into the interior of the container in order to illuminate the material contained in the interior. fluid. Preferably, the LED emits light of UV-C radiation in the wavelength range of 10 nm to 280 nm. Embodiments determined according to the invention can also comprise UV-B radiation (280 nm to 315 nm, "medium UV" according to standard DIN 5031-7) or UV-A radiation (315 nm to 380 nm). For the production of biofilms, it covers the wavelength range up to 338 nm.

Accordingly, the outer wall of the container or the actual reactor is essentially transparent for this purpose, in particular for UV-C or UV-B and/or if necessary UV-A radiation. Depending on the wall material and wall thickness and the reflection on the outer wall when light is incident obliquely, the wavelength-dependent transmission is for example greater than 50%, preferably greater than 80%, or even greater than 90%. Furthermore, when the wavelength of the light irradiated by the UV light-emitting diode is below 300 nm, for example crystal glass or borosilicate glass with high boron, fluorspar, sapphire or sodium potassium silicate, etc. are transparent and therefore suitable as containers material of the outer wall.

According to the invention, it is now provided in the device or in the UV reactor that the surface of the outer wall facing the interior has a particularly adapted shape in at least one subsection. The shape substantially matches the radiation field of the light emitted into the cavity by the light source. The radiation field feeds back the distribution of radiation intensity to various locations in the lumen. Here, intensity is understood to be the radiation intensity of the UV source per unit area. In the UV range, the radiation intensity corresponds as a physical parameter to the light intensity in the visible range. In addition to determining the radiation properties of the actual light source (distribution of the intensity in the spatial direction, for example by means of LEDs with optical components, if possible), the properties of the container in relation to the transparent coupling-in window also determine the radiation field or radiation. The distribution of intensity through various locations in the lumen of the container. These properties can interfere with incident UV light (absorption, transmission, reflection or specular reflection, interference, diffraction, scattering, etc.).

Furthermore, it is also possible to preset the transmission through the opaque portion of the fluid, on the basis of which the radiation field in the lumen can be determined. The opposing backscattering or reflective coating on the inner surface of the outer wall of the vessel or reactor is considered part of the light source.

According to one aspect of the invention, it is possible to match only sub-segments of the inner surface of the outer wall as described in terms of the shape of the sub-segments, for example only all such sub-segments lying within a preset spacing of the light sources, For example within a range of 10 mm (millimeters) or more and/or within a range of 20 cm or less. The sub-sections can also be respectively defined in closed geometries that together form the inner surface of the container (eg cylindrical or spherical outer surfaces, spherical segment outer surfaces, etc.).

According to another aspect of the invention, the inner surface of the outer wall is capable of matching the radiation field in its shape in all possible subsections, ie in the complete inner surface.

The principle of the invention consists in that instead of presetting a container with a defined shape of the inner surface and then adapting it to the light source in the best possible way in terms of positioning, radiation direction, etc., the light source is used instead to display the starting point of the superposition, and then Match the shape of the container to the radiation field formed. This design of the device can also be an iterative process because the shape matching of the container itself reacts to the radiation field.

Ultimately this can be achieved by presetting a minimum intensity for the radiation field and by adapting the shape of the container to the radiation field so that there are no points in the lumen below the minimum intensity. That is to say, by excluding the corresponding subspace of the radiation field by the inner cavity of the container, a small ecological environment with a smaller intensity or with an intensity lower than the minimum intensity is avoided. The specification of the minimum intensity sought is preferably less than 10% of the overall radiation falling on the inner surface of the outer wall, also preferably less than 5%, still preferably less than 2%. Finally, the minimum intensity should be above the threshold necessary for adequate disinfection, which results in, for example, a reduction in colony-forming units (KBE) by a factor of more than 10 ⁻⁴ .

A particular advantage is that the total volume or at least the respective total cross-sections of the inner cavity are detected by the radiation emitted by the UV light source, while the inner surface of the outer wall, for example directly due to biofilms, calcium precipitation or other contaminants, is not affected by the radiation field. cause effects that can no longer be controlled. In particular, the formation of biofilms at or on the inner surface is avoided by the minimum strength ensured directly at the inner surface. Otherwise, this may also cause changes in the radiation field itself. The formation of biofilms or the production of other contaminants or deposits thus no longer has a significant effect on the optical properties of the device.

Another advantage is that complex light sources or corresponding optics for illuminating the container can be dispensed with. As a result, outlays and costs can be saved.

Furthermore, it is possible to use, in addition to the coupling-in window, an opaque material for the outer wall, which also exhibits low reflectivity and little backscatter, in particular in the UV range, for example brass or stainless steel. It allows application in drinking water, so that the device can be used advantageously there.

换句话说，射入的UV光在内表面的部位处的强度至少在所观察的子部段的范围之中基本上是恒定的。因此，内表面(至少在该子范围中)造成恒定的强度的面。由此有利地实现了所有有关的表面范围的均匀和受控的照射。生物薄膜或病菌聚集物的形成被有效地抑制。此外得出用于流体的可能的最大容积，因为表面的形状与仅对应刚好必要的最小强度的这种等强度面“相关”，以便消灭UV反应器中的病菌。According to a development of the invention, the shape of at least a subsection of the surface facing the interior is substantially matched to the iso-intensity surface of the light emitted by the light source into the interior

In other words, the intensity of the incident UV light at the location of the inner surface is substantially constant, at least over the range of the subsections observed. Thus, the inner surface (at least in this sub-range) results in a face of constant strength. A uniform and controlled irradiation of all relevant surface areas is thereby advantageously achieved. The formation of biofilms or bacterial aggregates is effectively inhibited. In addition, the maximum possible volume for the fluid is obtained, since the shape of the surface is "correlated" with such an iso-intensity surface, which corresponds only to the minimum intensity just necessary in order to destroy germs in the UV reactor.

Furthermore, the materials for the containers that can be used according to this refinement are generally only subjected to small UV doses in terms of stability, integrity and durability. To this end it is ensured that only this minimum strength is present at the location of the inner surface of the outer wall. According to a corresponding development of the invention, the iso-intensity surface corresponds to a value of the intensity greater than zero.

Alternatively or additionally, the maximum distance between the iso-intensity surface and the LED is greater than or equal to 10 mm, and/or less than or equal to 20 cm. With these spacings of the fluid to be sterilized and a general opacity with a transmittance of 0.1 to 0.98 over a fluid thickness of 10 mm, a sufficient minimum strength can be guaranteed.

According to another development of the invention, the light source comprises two or more LEDs, which are designed to emit light from different positions to the container with a radiation characteristic via the outer wall of the container, respectively, or from corresponding positions in the vicinity of the outer wall. , wherein at least a subsection of the surface of the outer wall facing the inner cavity is substantially shaped to match the iso-intensity surface of the light superimposed by the LEDs. The superimposed radiation field caused by the plurality of LEDs allows for better and above all more uniform illumination of the inner cavity in the UV reactor. As a result, the geometrical requirements for a matching shape of the inner surface are simply met.

According to another refinement of the invention, the light source comprises two, three or more LEDs designed to direct light from different positions along a straight line or curve, respectively, via the outer wall of the container, or from corresponding positions near the outer wall. Starting from the position, it emits a radiation characteristic into the interior of the container, wherein, viewed in a cross-section of the container perpendicular to the line or curve, the shape of the surface of the outer wall facing the interior is adapted to the shape of the surface emitted into the interior by the at least one LED. The iso-intensity surface of the light in the cavity. This aspect relates in particular to flow reactors in which the vessel is designed in the form of tubes and the LEDs can be placed on the lines along the longitudinal axis of these tubes. In this case, only adjacent LEDs overlap with respect to the radiation fields generated by them, if possible. This aspect also proposes that each LED illuminates, as optimally as possible for itself, the cross-section that is exactly assigned to this LED at a certain longitudinal distance (eg the distance to the closest LED on the line). For this purpose, according to this refinement, the cross-section (considered as the space removed via the longitudinal distance) is adapted to the radiation field in terms of the shape of its inner surface.

The two last-described aspects (superposition of radiation fields of multiple LEDs, sequential arrangement of LEDs along the tube in the flow reactor) can be advantageously combined.

According to another development of the invention, the shape of the surface of the container facing the inner cavity corresponds to the shape of a truncated cone with a flat top surface or a top surface that is curved into the inner cavity or outwards from the inner cavity, An outer cover surface and a flat or curved bottom surface from the inner cavity, wherein the light source or at least one LED is arranged on or near the top surface of the frustoconical shaped surface of the container. This shape has proven to be particularly advantageous when, with only one LED or a few LEDs placed next to each other, the radiation fields of the LEDs generated by the UV light are superimposed on each other. When an LED or LEDs are placed outside the in-coupling window near the top surface as an in-coupling window, a flat or curved top surface into the cavity enables a cone-shaped incidence of UV light into the cavity.

The outer cover surface is adapted to the radiation cone in terms of shape and fixation, wherein the inner surface is preferably arranged on an iso-intensity surface corresponding to the minimum intensity as described above, ie as far as possible not directly in the shadow outside the cone. The outer cover surface is allowed to have a small curved dome, since the deviation of the iso-intensity surface towards the optical axis (truncated cone axis) from the ideal cone shape increases as the distance from the light source increases.

Here, too, the bottom surface can be adapted to the radiation field in terms of shape and fixation. Depending on the radiation properties of the LED, the bottom surface can be bent outwards from the inner space in order, for example, to comply with a predetermined iso-intensity surface. The surface point with the greatest distance to the light source can lie on the optical or frustum axis.

The truncated cone-shaped vessel can be a refillable tank with only one inlet/outlet, or have an inlet and a further outlet and thus operate as a flow reactor.

A particular advantage of this aspect or this refinement is that the complete inner surface of the container can lie substantially on the iso-intensity surface, with the exception of course the transparent coupling-in window, ie the top surface and the optical inlet and/or outlet. The formation of germs and/or the production of biofilms is particularly effectively avoided here. At the same time, a good ratio of the outer wall material used and the enclosed volume is achieved here, while at the same time generating only a small outlay in terms of the structure of the LED arrangement.

According to a refinement of the aforementioned aspect of the invention (ie the frustum shape), the outer cover has a half-span angle θ, wherein the half-span angle θ corresponds substantially to the total reflection applicable to the boundary surface between air and fluid Angle. This property ensures that the inner surface of the outer wall of the outer shroud of the frustum falls exactly on the shadow boundary of the incident light.

The half-opening angle θ can for example be between 40° and 55°, preferably between 45° and 50°, also preferably between 48° and 49°, most preferably between 48.5° and 49° in the special case of water and air between 48.8°. The exact value of total reflection at the boundary between air (standard conditions) and liquid pure water is about 48.75°.

According to another refinement of the aforementioned aspect with regard to the shape of the truncated cone, the base of the surface of the truncated cone shape has the shape of a spherical surface with a spherical radius r that is curved outwards from the inner cavity. This results in a simple geometry of the container together with the outer cover, which also has a relatively large volume. It is further characterized in that the spherical segment formed accordingly and mounted at the distal end of the outer shroud surface is connected to the corresponding iso-intensity surface of the radiation field in the lumen. This can correspond to a preset minimum intensity, as described above.

According to a further development of the aforementioned aspect with the outer cover surface and the spherical section, the container has a height H measured from the midpoint of the top surface along the axis of symmetry of the container to the point of intersection with the spherical surface. In this embodiment, the ratio between the height H of the container and the spherical radius r of the outwardly curved spherical surface is between 1.25 and 2.01, preferably between 1.35 and 1.91, also preferably between 1.35 and 1.85. Assuming water as the fluid, for this value range a particularly good match of the geometry to the iso-intensity surfaces formed therein is found.

According to a particular embodiment of this aspect, the device for sterilizing the fluid (in particular water-based) is set such that the fluid has a transmittance T measured through 10 mm of the fluid or normalized to the fluid, Therein, the ratio H/r between the height H of the container and the radius r of the sphere is approximately 0.62·T+1.29. In other words, especially for special fluids, particularly optimized geometries with regard to the shape of the truncated cone are obtained.

According to a further development of the aforementioned aspect with the cover surface and the spherical section, one or more sensors are provided on the spherical surface opposite the at least one LED. The sensor detects light that is emitted into the cavity and exits through the spherical surface. This makes it possible on the one hand to determine the function of the LED and on the other hand to measure the transmittance of the fluid currently flowing through or present in the container. With the aid of a sensor, it can then be determined in light of the above-mentioned optimized ratio between the height H of the container and the radius r of the spherical segment surface whether this approximation is currently valid for the iso-intensity surface for the measured transmittance. If, for example, this is the negative case after a longer period of time, measures can be taken to prevent possible germ formation or biofilm formation, in the simplest case increasing the radiant power of the LED.

According to another refinement of the previous aspect with the outer cover surface and the spherical section, the top surface is flat and circular, and the top surface has a radius ρ which is at most R+14mm, preferably R+1.6mm, where R is the radius of the circular (light) source face of the respective application in the light source (ie for example half the diameter of the light source).

According to an embodiment, the radius ρ can derive a maximum value from this:

ρ=R+l·tan(α)+d·tan(arcsin(n ₁ /n ₃ ·sin(α))) (1)

where a is the maximum angle (relative to the optical or symmetry axis) until the ray can enter the glass of the top surface and transmit into the lumen (and is not reflected). The maximum angle can be greater than or equal to 75°, preferably greater than or equal to 80°, also preferably greater than or equal to 85°. R is the radius of the circular (light) source face of the respective application in the light source, l is the distance from the light source to the window (to the top face) and can be purely exemplary between 0.2 mm and 1 mm, and d is the transparent glass The thickness of the material can for example be between 1 mm and 3 mm. Correspondingly, n ₁ is the refractive index of air (eg n ₁ =1.0) and n ₃ is the refractive index of glass (eg n ₃ =1.46 in the case of crystal glass).

According to a completely different development of the invention, the radiation field of the light emitted into the interior cavity by the light source with at least one LED is generated by the optical components of the light source. Here, the optical component concentrates the light towards the axis of symmetry of the container and thus delimits the light to a spatial extent with an envelope. In this case, the shape of at least a subsection of the surface of the outer wall of the container facing the interior substantially corresponds to the envelope. The optical components can comprise mirrors and lens elements, which in a preferred embodiment are TIR (Total Internal Reflection) lenses (TIR: Total Internal Reflection). The combination of lens and reflector is involved here. In any case, the aim is to generate collimated or discrete or focused, in any case concentrated, light rays from one or more point light sources. Concentration at the edge of the radiation field with the beam results in a very steep intensity slope transverse to (ie substantially perpendicular to) the optical axis. The radiation field is clearly delimited. An edge with a very steep slope is an envelope.

In this radiation field, the inner surface matches the envelope exactly so that it achieves a minimum intensity of radiation, preventing the formation of germs and the creation of microfilms. In this case, the radiation field is used optimally and the formation of undesired niches is prevented.

According to a development of this aspect, the shape of at least a subsection of the surface of the outer wall facing the lumen corresponds to a tube extending along the axis of symmetry. A light source with at least one LED and optics can be fixed at the end of the tube. Subsequently, the beam of rays is oriented along the axis of symmetry or tube axis, ie the optical axis and the flow direction coincide. The fluid here flows onto the light source or away from the light source through the tube. This embodiment is particularly advantageous in terms of uniform irradiation and thus sterilization as well as high flow rates and thus mechanical film removal.

Additional optical components are also contemplated, such as lenses, reflectors, diffractive optics (gratings, optical slits, etc.), holograms, and the like.

According to a refinement of this aspect, the tube has an inner diameter that decreases as the distance from the optical component to the constriction increases along the axis of symmetry. The light emitted convergingly by the optics of the light source is focused at the location of the constriction. The device is particularly advantageous in that, by focusing, also a simpler intensity profile is maintained at a greater distance from the light source, so that co-flowing germs are also exposed to approximately the same UV over a longer distance as the inner surface of the outer wall at the strength level. Furthermore, the constriction locally increases the flow velocity, further making the formation of biofilms in this central region more difficult. The re-widened area behind the constriction (viewed from the light source) can be cleaned, for example, by means of special inlet nozzles for the fluid. Or alternatively, a second light source with corresponding optics is provided on a corresponding further side of the first light source, eg in a mirror-symmetric arrangement.

According to another refinement of this aspect, the device is designed as a flow reactor with an inlet and an outlet for the fluid, respectively, provided in the vessel, wherein the inlets are respectively provided at the ends of the tubes. In a particularly preferred embodiment, the light source with optics can be flushed around by a flowing fluid, which provides a linear rectilinear arrangement.

According to the invention there is also provided a method for manufacturing a device as described above. The method includes the following steps:

A light source comprising at least one LED is preset, wherein the light source is provided to transmit light with a wavelength in the UV-C radiation range via the outer wall of the container for holding the fluid or from a corresponding position in the vicinity of the outer wall with a a radiation characteristic is emitted into the interior cavity of the container to irradiate the fluid contained in the interior cavity, wherein the container has an outer wall surrounding the interior cavity;

determining a shape in at least one subsection for the surface of the outer wall facing the inner cavity, the shape substantially matching the radiation properties of the light emitted into the inner cavity;

A container is produced having an outer wall whose surface facing the inner cavity has this shape, and the light source and the container are combined together.

This method yields the same advantages as the reference device and its refinements.

Description of drawings

Further advantages, features and details of the invention emerge from the following description of preferred embodiments and from the accompanying drawings. In the drawings, the same reference numbers refer to the same features and functions.

Shown here:

Figure 1 shows a schematic cross-sectional view of a UV flow reactor according to a first embodiment of the present invention;

FIG. 2 shows a graph of the height H of the flow reactor according to the first embodiment on the one hand with the radius r of the spherical section of the truncated cone shape used and on the other hand with the ratio of the transmittance T of the fluid flowing through it ;

Figure 3 shows a schematic cross-sectional view of a UV flow reactor according to the second embodiment (with LEDs 8a, 8b, 8c) or according to the third embodiment (with one LED);

Figure 4 shows a schematic translucent perspective view of a flow reactor with a now tubular vessel according to a fourth embodiment;

5 shows a schematic cross-sectional view of a tubular UV flow reactor with a TIR lens and a beam waist according to a fifth embodiment of the present invention;

6 shows a schematic cross-sectional view of a tubular UV flow reactor with a TIR lens and a beam waist according to a sixth embodiment of the present invention.

Detailed ways

Figure 1 shows a schematic cross-sectional view of a first embodiment of a device 1 for sterilizing fluids. This is a flow reactor with an inlet 4 and a separate outlet 6 . The fluid to be sterilized here can be, as mentioned at the outset, for example, rinse water or wash water or the like. The device 1 comprises a container 2 , ie the actual UV reactor, and a light source 8 , which in this case is designed as an LED emitting UV-C radiation. The present invention is not limited to certain technologies, but can relate to LEDs mounted in the form of SMD (surface mounted device) or COB (chip-on-board). One or more control devices (not shown) can likewise be provided in this and the following embodiments, which control the operation of the light source and possibly the pump for the flow, eg the sensor 10 shown in FIG. 1 . (not shown). With the sensor 10 it is possible to determine the transmittance of the fluid currently flowing and to check the function or state of the LEDs, for example the degree of ageing.

The container 2 is designed in the shape of a truncated cone in this particular implementation. The container includes an outer wall 12 having an inner surface 14, a frustoconical shape having a top surface 16, an outer cover surface 18 and a (here strongly) outwardly curved bottom surface 20. The top surface 16 or the top wall is circular and designed to be flat and is designed as a coupling-in window. The light sources 8 or UV light-emitting diodes have source surfaces (light-emitting substrate surfaces) which are arranged at a distance l from the top surface 16 or the outer surface of the coupling-in window. In this example, the light source is arranged outside the container 2 . The spacing l is chosen to be as small as possible in order to be able to use as much UV light power as possible. The spacing should be less than or equal to 0.5 mm, preferably less than or equal to 0.2 mm. The spacing l can also preferably be chosen to be between 0.2 mm and 0.5 mm.

In this example, crystal glass is used purely by way of example as material for the coupling-in window. It can be achieved that the coupling-in window, ie the top surface 16 , is designed as an actual window in the container 2 , ie the outer wall 12 in the region of the outer cover surface 18 and the bottom surface 20 can be made of other opaque materials, for example steel or brass. to make. It is also possible, however, for the entire outer wall 12 to be made of a material that is transparent to the corresponding UV radiation (UV-A, UV-B or UV-C) and is also in each case stable, and is independent of the relative relative light source 8 The position obtains the function of the coupled input window.

Another portion of the inner surface 14 is configured as a spherical cover surface 18 which extends from the top surface 16 and spreads with a constant opening angle along the axis of symmetry 22 at increasing distances from the light source 8 and the top surface 16 . The expansion need not be constant, it can also be slightly bell-shaped (expanding with increasing spacing), or slightly parabolic (expansion slightly decreasing), etc. The half-opening angle θ of the cover surface (ie the angle of the cover surface with respect to the axis of symmetry 22 ) is here 47.5°. This angle corresponds approximately to the total reflection angle for radiation from the interior of the container to the boundary between water and air (critical angle in the UV-C range: about 48°, where the transparent material of the container is ignored in this design, because It has essentially no effect in the transition of radiation from water into the container and from the container into the surrounding air). The angle is calculated from this:

θ _crit = arcsin(n ₁ /n ₂ ) (2)

where n ₁ is the index of refraction of the source environment and n ₂ is the index of refraction of the fluid (eg water) at the respective wavelengths of the incident light. The value chosen for the opening angle is approximately less than the critical angle for total reflection, so that the inner surface 14 of the outer wall 12 applies a certain radiation in the region of the outer cover surface 18 .

In the inner cavity 24 of the container 2, the UV-C light emitted from the light source 8 via the coupling-in window (top surface 16) depends on the radiation characteristics of the light source (radiation intensity in various spatial directions), the optical characteristics of the coupling-in window and The reflection and/or backscattering of the inner surface 14 of the outer wall 12 forms the radiation field. FIG. 1 shows schematically (in dashed or dotted lines in cross section) so-called iso-intensity surfaces I1 , I2 , I3 , I4 , which are represented in space with the respectively predetermined and identical constant intensities. Because the intensity decreases with increasing distance from the light source, the iso-intensity surfaces I1 to I4 roughly form a replicated sphere in the inner cavity 24 . The following applies here: Intensity of the iso-intensity surface I1>Intensity of the iso-intensity surface I2>Intensity of the iso-intensity surface I3>Intensity of the iso-intensity surface I4.

However, it can be at least implicitly recognized in FIG. 1 that, due to the approach to the critical angle θ _crit , a steep intensity slope is formed towards the lateral edge of the inner cavity 24 , ie towards the outer wall 12 , because relative to the optical or symmetry axis 22 , a steep intensity slope is formed. Larger angles prevent radiation from exiting the light source 8 into the fluid contained in the lumen 24 . The transition is relatively abrupt. In this schematic illustration, there are also iso-intensity planes I1 to I4 in the cavity. Here, however, the half-opening angle θ is chosen as described so that there is always a minimum intensity on the inner surface, but only so much that at most 10% of the radiation power falls on the inner surface 14 of the outer wall 12 .

In this way, however, there is still always sufficient UV-C radiation power to reach the outer wall 12 so that no germs or biofilms can form on the inner surface 14 of the outer wall. At the same time the majority of the radiant power is used for extensive transmission.

As shown in FIG. 1 , the edge 26 of the outer cover surface 18 is connected with a bottom surface 20 in the shape of a truncated cone, which is curved outward from the inner cavity. The inner surface can be coated in this area (but also in the area of the outer cover for reflection or backscattering) with a corresponding material, for example by aluminum, PTFE (polytetrafluoroethylene) or TiO2-filled material or Dielectric coating systems, etc.

As already mentioned, an iso-intensity surface in water can be approximately formed in the lateral outer wall 12 and at a distance from the outer wall through a spherical surface in the range of a transmittance of 0.1 to 1.0 at a depth of 10 mm. In this embodiment, the bottom surface is substantially spherical segment-shaped. The shape of the bottom surface is roughly approximated by the equal-intensity surface I4 of the intensity. The bottom surface is therefore also curved outwards here. This strength level is also approximated by the inner surface 14 in the extent of the outer cover surface 18 in the same manner. A value slightly below this strength level represents in this embodiment the minimum strength present in each subsection of the inner surface 14 of the outer wall 12 , except the inner surface of the top surface 16 and the inlet 4 or outlet 6 . This avoids weak points in the surface of the container, where germs or biofilms first form.

FIG. 2 shows the height H of the flow reactor or vessel 2 (only in terms of the height of the inner chamber) on the one hand with the radius r of the spherical section used for the truncated cone-shaped bottom surface 20 and on the other hand with the current flow through A plot of the ratio of the transmittance T of the fluid. FIG. 1 shows schematically the radius r from the spherical base 20 to the midpoint M. The reduced transmittance affects the degree of backscattering and reflection from the inner surface, and thus indirectly the radiation field, so that the spherical segment shape is also matched to its radius r when striving for an optimal approximation of the iso-intensity surface. The lines marked in the diagram of FIG. 2 therefore represent, for the corresponding transmittance T, the ratio (H/r) for the container 2 which is optimized in this respect, respectively. A simulation is performed on the basis of this chart. The equation is given approximately for the line in Figure 2:

H/r=0.62·T+1.29 (3)

Furthermore, the top surface 16 of the frustum shape can be calculated. Its maximum radius ρ can be calculated from this as described above:

ρ=R+l·tan(α)+d·tan(arcsin(n ₁ /n ₃ ·sin(α))) (4)

where a is the maximum angle (relative to the optical or symmetry axis) until the ray can enter the glass and be transmitted into the lumen and not be reflected by the glass. R is the radius of the respectively applied circular (light) source face, l is the distance from the light source to the window (top face), and d is the thickness of the transparent glass material. Correspondingly, n ₁ is the refractive index of air (eg n ₁ =1.0), and n ₃ the refractive index of glass (eg n ₃ =1.46 in the case of crystal glass being used here). The three terms on the right-hand side of the equation, in terms of plane geometry, result from the extension of the source surface itself, the expansion optical path up to the window, and the optical path that continues to expand through the window material in this order. Preferred values for the spacing l between the source surface and the window are given above (less than or equal to 0.5 mm or less than or equal to 0.2 mm). The crystal glass window of the top surface 16 can have a thickness d of 1 mm. It can also require 3-5 mm (in the range of 1 to 5 mm overall) in terms of greater pressure stability in the container 2 . These particular values which limit this embodiment are however not considered, and other values are possible, especially when other materials are used or other geometries or at least variations thereof are used, or when the device is to be used to sterilize other fluids .

It is to be noted that the inlet and outlet shown in Figure 1 are optional, and in other words an integral inlet and outlet (not shown) can be employed. In this case, the container 2 is a refillable tank and the fluid is located in the container during sterilization. In the last case, a stirrer or agitator (not shown) can also be provided, which operates continuously or only at intervals, in order to achieve a uniform dose of radiation through the fluid. Optionally, the device can be arranged such that it moves the container 2 so as to cause eddy currents, eg vibratory motions, in the cavity.

Figure 3 shows a schematic cross-section of a second or third embodiment of a device 1' according to the invention. Details of Figure 1 such as sensors or inlets and outlets are omitted here. The example of FIG. 1 is here modified so that, according to the second embodiment, the light source 8 is composed of 3 or more LEDs 8a, 8b, 8c, wherein the UV light of the light sources emitted into the inner cavity 24 is superimposed into a common radiation field . Here, the LEDs 8a to 8c can have different optical axes or axes of symmetry 22a, 22b, 22c in order to illuminate the inner cavity 24 better and more efficiently. The radiation field obtained is fanned out more widely, so that the enclosing conical shape caused by the critical angle of the now more complex top surface 16' has an additional opening angle. The spherical base surface 20 thus takes advantage.

As an alternative to the LEDs 8a to 8c, the third embodiment involves only one LED, however it is now placed in the cavity 24 instead of outside. Since there is no coupling-in window, the axis now determines the radiation field in the cavity 24 by the radiation properties of the light source 8 itself, which can emit light from its source surface into the cavity 24 at other angles. Here, the inner surface 14 of the outer wall 12 of the container 2' is matched to the equal strength surface in a shape very similar to that in the second embodiment.

FIG. 4 shows a fourth embodiment. In the translucent perspective view, the LEDs 8e, 8f, 8g, 8h, 8i of the light source 8 are arranged in a line. The device 1 ″ shown is a flow reactor, wherein the container 2 , which is shown in a rotationally symmetrical cross-section in FIG. 1 , is here converted into a tubular container 2 ″, by which the fluid is moved in the longitudinal direction 28 . The UV light of the LEDs 8e to 8i is also at least partially superimposed here. The basic idea here, however, is that each of the LEDs 8e to 8i of the light source 8 illuminates through its corresponding length or distance 30 for at least one cross-section 34 (shaded surface in FIG. 4 ) of the use of the tubular container, The LEDs of the light source 8 are implemented for the entire container as they were in the first exemplary embodiment. The shape of the inner surface 14 is then adapted to the radiation field in the inner cavity 24 in a corresponding subsection 32 , eg for the UV light emitted by the LEDs 8i . The arrangement of the LEDs relative to the top surface 16 is similar to that in the first embodiment (FIG. 1). In principle, containers corresponding to a plurality of LEDs are arranged side by side according to FIG. 1 , wherein the shapes of the LEDs are opened and connected by stacking them into tubes.

FIG. 5 shows a fifth embodiment. Recognized in the cross-sectional view of the device by the tube shape of the associated vessel 2"', it relates to a flow reactor. At one end of the vessel 2"' (left side in Figure 5), outside the coupling-in window The LEDs 8k of the light source 8 are provided, which emit UV light into the inner cavity via mirrors 81, 8m of the TIR lens arranged in the inner cavity 24 . As mentioned above, UV-C, UV-B or UV-A can be involved. The TIR lens affects a collimated or slightly focused or slightly dispersed beam 36, which is directed along the longitudinal and symmetry axis 42 of the tubular container 2"'. As identified (outer rays are indicated only schematically), The beam 36 has an envelope 44 whose diameter decreases with increasing distance from the light source 8 to the constriction 46 with a certain distance from the light source 8 .

According to this embodiment, the shape of the subsection 48 from the TIR lens (mirrors 81, 8m) of the light source 8 to the outer wall of the corresponding tube of the constriction 46 is adapted to this envelope. In other words, the container 2"' is itself waisted and has the same narrowing 46 at a predetermined distance from the light source 8. The envelope, as in the first embodiment, exhibits a steep intensity slope, at Therein, the inner surface 14 of the subsection 48 is "placed" by matching the shape of the container 2"' so that there is still a minimum strength on this inner surface.

Furthermore, through the focusing action of the TIR lens, the intensity level is maintained higher via further regions along the optical or longitudinal symmetry axis 42 . Depending on the application, the focal point, ie the spacing of the constrictions 46, can be selected differently. Preferably, it should be in the range of the penetration depth, in which the radiation in the fluid falls on approximately half of the output power in the orientation of the light source 8 . Particularly preferably, the narrowings 46 should be in a spacing in which the radiated power drops by a factor of 1/e ² , ie about 0.135 (ie about 13.5% of the radiated power).

According to an alternative embodiment, the generated beam of rays can be slightly dispersed by the light source 8 (optical component with TIR lens) in a similar manner as in FIG. 5 also by a half angle of 10° or less.

In these embodiments (also as follows), the reactor has a length according to the transmittance of the fluid to be sterilized, the effective transmittance at the end of the tubular container 2"' being only 0.1 compared to the output power or less, preferably 0.05 or less.

In the fifth embodiment, the flow direction 38 in the reactor is opposite to the direction of the beam 36, ie towards the light source. However, the flow direction can also be directed away from the light source in reverse. Furthermore, in the fifth embodiment, the outlet 6 is provided laterally bifurcated at the level of the TIR lenses (mirrors 81, 8m). In the case of a flow direction opposite to that of FIG. 5 , nozzles (not shown) can be provided which, by means of strong rays, prevent the formation of germs or the like in the inlet region (at the position of the outlet 6 in FIG. 5 ).

Figure 6 shows a cross-section through a device 1"" for sterilizing fluids of a sixth embodiment. The structure is similar to FIG. 5, so that only the differences are explained in the following description. The light source 8 has LEDs 8n, which are now arranged therein instead of being arranged outside the tubular container 2"". In an arrangement similar to the fourth embodiment, the optics are provided in the form of TIR lenses with mirrors 81, 8m, which as described above generate a collimated or focused (or slightly divergent) beam of rays with an envelope . The shape of the envelope of the matching waist of the inner surface 14 of the outer wall in the subsection 48 up to the narrowing 46 is similar to that of FIG. 5 .

By means of the arrangement of the LEDs in the tubular container 2"", it is possible to surround the flushing light source 8 with a fluid, as indicated by the arrows 39a, 39b in Fig. 6 . As a result, the light source 8, in particular its LEDs 8n, can be effectively cooled. Furthermore, a linear linear arrangement is achieved by this structure. In the embodiment shown, the opposite flow direction 39 to the fifth embodiment is chosen, ie the fluid surrounds the irrigating light source and then exits therefrom through the narrowed tubular container to the outlet 6 .

According to a particular refinement of this embodiment, the outlet 6 on the right side of the container 2"" in Fig. 6 is made of transparent glass, such as a crystal tube. In this case, the light-guiding effect of the crystal glass can lead to radiation transmission up to the outlet of the tube, wherein the tube can also be bent in the region of the outlet 6 . This achieves a sterilization action up to the outlet 6 and up to its outlet.

However, a reversal of the flow direction 39 is also possible in the embodiment shown in FIG. 6 . Such a configuration is reasonable when the device is implemented to avoid radiation exit at the outlet, in which case the outlet is located behind the light source 8 on the left side of FIG. 6 . Therefore, the safety specification can support the calculation.

The improvements of the fifth and sixth embodiments, including their variants, etc., are provided in the tap (kitchen or bathroom fitting) or in a similar water supply pipe or inlet to realize the device having the tubular container 2"', 2"" .

It should be noted that the above embodiments represent special implementations and do not limit the protection scope of the present invention. In particular, the individual features of the individual embodiments can also be combined in other embodiments, respectively. Therefore, the materials described for the first three embodiments for the outer wall 12 are also used in the fifth and sixth embodiments and their variants, namely in particular crystal glass or crystal or borosilicate glass with high boron, Fluorspar, sapphire or sodium potassium silicate glass. Furthermore, the advantages of said steel or brass including the selection of all corresponding alloys etc. can be used in all embodiments, the alloys have only a small reflection in the UV-C wavelength range.

In the first three embodiments ( FIGS. 1 to 4 ), the light source 8 and the corresponding coupling-in window are shown below. However, the corresponding device or container can also be turned by 180 degrees, so that the coupling-in window is positioned above the container. In this case, it is possible to remove the coupling-in window or top surface 16 . This has the advantage that the fluid no longer comes into contact with the window and disrupts biofilm formation. In addition, optics have been eliminated. The light source can be protected by air pressure, air flow or air valve.

Likewise, a mechanical brush can also be provided in the presence of a window (which applies to all embodiments), which removes biofilms or germs in the container, for example at certain time intervals.

Furthermore, only the first 3 examples are described for reflective or backscattered coatings (eg aluminum or PTFE, etc.). It will be immediately appreciated, however, that this coating can be used in the same manner on the inner surface 14 of the outer wall 12 in a similar manner also in the fourth or fifth embodiment and its variants.

In the preceding embodiments, LEDs emitting UV-C radiation were described in terms of light sources 8 . Depending on the application, however, it is thus also possible to use LEDs emitting UV-A or UV-B radiation, or in particular combinations of LEDs with various radiations in one arrangement.

The present invention is not limited to the fluid in the form of wash water or rinse water used in the particular embodiment. Other fluids than water, such as blood, milk or diesel microbial contamination can also be sterilized by the UV reactor according to the invention. This also includes non-liquid fluids such as air or smoke.

List of reference signs

1, 1’, 1”, 1”” device

2, 2', 2", 2"', 2"" Vessel (Reactor)

4 entrances

6 exit

8 Light source

8a-8k, 8n LEDs

Mirror for 8l, 8m TIR lens

10 Sensors

12 outer wall

14 inner surface

16 top

16’ top surface with more complex construction

18 outer cover

20 Bottom surface (spherical surface)

22, 22a Axis of symmetry

22b, 22c Additional axis of symmetry

24 lumen

26 Edge of the outer face

28 Portrait orientation

30 distance (segment assigned to LED)

32 Subsections

34 Cross-section (of the container) perpendicular to the LED arrangement

36 beams

38 Flow direction

39 Flow direction (reverse)

42 Axis of symmetry

44 Envelopes of ray beams

46 Stenosis

H height

Intensity surfaces such as I1, I2, I3, I4

l Spacing from LED to top surface or crystal glass window

The midpoint of the M sphere

r the radius of the sphere

θ half-opening angle.

Claims (24)

1. An apparatus for disinfecting a fluid, comprising:

a container (2, 2 ', 2 "', 2" ") for containing the fluid, wherein the container has an outer wall (12) enclosing an inner cavity (24);

a light source (8) comprising at least one LED (8a-8k, 8n), wherein the light source is configured to emit light having a wavelength in the UV radiation range into an inner cavity of the container via the outer wall (12) of the container or from a corresponding position near the outer wall with a radiation characteristic in order to irradiate the fluid contained in the inner cavity;

wherein a surface (14) of the outer wall (12) facing the inner cavity (24) has a shape in at least one subsection that is matched to the radiation characteristic of the light emitted into the inner cavity (24).

2. The device of claim 1, wherein the shape of at least the sub-sections of the surface (14) facing the lumen (24) matches a uniform intensity plane (I1, I2, I3, I4) of the light emitted into the lumen by the light source (8).

3. The device according to claim 2, wherein the equal intensity face (I1, I2, I3, I4) corresponds to a value of intensity greater than zero and/or the maximum spacing of the equal intensity face from at least one of the LEDs is greater than or equal to 10mm and less than or equal to 20 cm.

4. The device according to any one of claims 1 to 3, wherein the light source (8) comprises two or more of the LEDs designed to emit light into the inner cavity (24) of the container with one radiation characteristic, starting from different positions via the outer wall (12) of the container or from corresponding positions in the vicinity of the outer wall (12), respectively, wherein the shape of at least the sub-sections of the surface of the outer wall facing the inner cavity is matched to a plane of constant intensity of the light superimposed by the LEDs.

5. The device according to any one of claims 1 to 3, wherein the light source (8) comprises two, three or more LEDs designed to emit light into the inner cavity of the container with one radiation characteristic from different positions along a line or curve via the outer wall (12) of the container or from respective positions in the vicinity of the outer wall, respectively, wherein the shape of the surface (14) of the outer wall facing the inner cavity (24), viewed in a cross section (34) of the container perpendicular to the line or curve, respectively, matches the plane of equal intensity of the light emitted into the inner cavity by the respective LED.

6. Device according to any one of claims 1 to 5, wherein the shape of the surface (14) of the container facing the inner cavity (24) corresponds to a truncated cone shape with a top surface (16) which is flat or curved into or out of the inner cavity, an outer cover surface (18) and a bottom surface (20) which is flat or curved out of the inner cavity, wherein the light source (8) or at least one of the LEDs is arranged at or near the top surface (16) of the surface of the truncated cone shape of the container.

7. The device according to claim 6, wherein the outer cover (18) has a half opening angle (θ), and

the half opening angle (theta) corresponds to an angle of total reflection applicable to a boundary surface between air and the fluid, or

The half opening angle (θ) is between 40 ° and 55 °.

8. The device according to claim 7, wherein the half opening angle (θ) is between 45 ° and 50 °.

9. The device according to claim 8, wherein the half opening angle (Θ) is between 48 ° and 49 °.

10. The device according to claim 9, wherein the half opening angle (Θ) is between 48.5 ° and 48.6 °.

11. The device according to any one of claims 6 to 10, wherein the bottom face (20) of the surface (14) of truncated cone shape has the shape of a spherical surface with a spherical radius (r) curved outwards from the inner cavity (24).

12. The device according to claim 11, wherein the container has a height (H) measured from the midpoint of the top surface (16) along the axis of symmetry (22, 22a) of the container to the point of intersection with the spherical surface, and

the ratio between the height (H) of the container and the spherical radius (r) is between 1.25 and 2.01, or

The means for disinfecting the fluid are set such that the fluid has a transmittance T measured through or normalized with a liquid of 10mm, and the ratio (H/r) between the height (H) of the container and the sphere radius (r) is 0.62-T + 1.29.

13. The device according to claim 12, wherein the ratio between the height (H) of the container and the spherical radius (r) is between 1.35 and 1.91.

14. The device according to claim 13, wherein the ratio between the height (H) of the container and the spherical radius (r) is between 1.35 and 1.85.

15. The device according to any one of claims 11 to 14, wherein one or more sensors (10) are provided at the spherical surface opposite at least one of the LEDs, said sensors detecting the light emitted into the lumen (24) and exiting via the spherical surface.

16. The device according to any one of claims 6 to 15, wherein the top surface (16) is flat and circular and the top surface is

Having a radius ρ up to R +14 mm; or

Having a radius p, the value of which is at most R + l tan (α) + d tan (arcsin (n)₁/n₃Sin (α))), wherein α is the maximum angle relative to the axis of symmetry until rays can enter the glass of the top face and are transmitted into the interior cavity and are not reflected by the glass, R is the radius of the source face of the LED, l is the spacing between the source face and the top face (16), and d is the thickness of the top face (16), and n is₁Is the refractive index of air, and n₃Is the refractive index of the transparent material of the top surface.

17. The apparatus of claim 16, wherein the top surface has a radius p, the radius R +1.6 mm.

18. The device according to any one of claims 1 to 4, wherein the radiation characteristic of the light emitted into the inner cavity by the light source (8) with at least one LED is produced by optics (8l, 8m) of the light source (8), wherein the optics concentrate the light towards the axis of symmetry of the container and thus bound it to a spatial extent with an envelope (44), and the shape of at least the sub-section of the surface (14) of the outer wall (12) of the container facing the inner cavity (24) coincides with the envelope (44).

19. The device according to claim 18, wherein the shape of at least the sub-section of the surface (14) of the outer wall (12) facing the inner cavity (24) corresponds to a tube extending along the axis of symmetry, the light source (8) with the at least one LED and the optical component being located at an end of the tube.

20. The device according to claim 19, wherein the tube has an inner diameter which decreases with increasing distance along the symmetry axis from the optical component to a narrow portion (46) at a focal position of the light emitted convergently by the optical component of the light source (8).

21. The device according to any one of claims 18 to 20, wherein the optical component (8 i, 8m) comprises a total internal reflection lens.

22. The device according to any of claims 19 to 21, wherein the device is designed as a flow reactor with an inlet (4) and an outlet (6) for the fluid, respectively, provided in the vessel, wherein the inlets are provided at the ends of the tubes, respectively.

23. The device according to any one of claims 1 to 17, wherein the container of the device is designed as a refillable tank or alternatively as a flow reactor with an inlet and an outlet for the fluid, respectively, provided in the container.

24. A method for manufacturing the device of any one of claims 1 to 23, the method comprising:

presetting a light source (8) comprising at least one LED, wherein the light source is configured to emit light having a wavelength in the UV-C radiation range into an inner cavity of a container (2, 2 ', 2 "', 2" ") for containing the fluid via an outer wall (12) of the container or from a corresponding position in the vicinity of the outer wall with a radiation characteristic in order to irradiate the fluid contained in the inner cavity, wherein the container has an outer wall (12) surrounding the inner cavity (24);

determining a shape of a surface (14) of the outer wall (12) facing the inner cavity (24) in at least one subsection, which shape matches the radiation characteristic of the light emitted into the inner cavity (24);

-manufacturing the container (2, 2 ', 2 "', 2" ") with the outer wall (12) whose surface (14) facing the inner cavity (24) has the shape, and combining the light source (8) and the container (2, 2 ', 2"', 2 "").

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