DE102010047318A1 - Ultraviolet semiconductor light source irradiation device useful for e.g. sterilization and physical excitation of molecules into higher physical excitation state, comprises ultraviolet semiconductor light source and irradiation chamber - Google Patents

Abstract

Ultraviolet semiconductor light source-irradiation device comprises at least one ultraviolet semiconductor light source (1), and an irradiation chamber (2), by which a medium to be irradiated is conducted along a main flow direction. The primary radiation emitted by the ultraviolet semiconductor light source in the operating state passes at an angle of greater than 60[deg] to the main flow direction through the medium to be irradiated. The inner wall (3) of the irradiation chamber for the emitted radiation of the ultraviolet semiconductor light source exhibits a reflection degree of at least 95%. Ultraviolet semiconductor light source irradiation device comprises at least one ultraviolet semiconductor light source (1) and an irradiation chamber (2), by which a medium to be irradiated is conducted along a main flow direction. The primary radiation emitted by the ultraviolet semiconductor light source in the operating state passes in an average angle (alpha ) of greater than 60[deg] to the main flow direction through the medium to be irradiated. The inner wall (3) of the irradiation chamber for the emitted radiation of the ultraviolet semiconductor light source exhibits a reflection degree of at least 95%, so that the radiation emitted by the ultraviolet semiconductor light source is reflected several times within the irradiation chamber. An independent claim is also included for irradiating the medium conducted along the main flow direction with ultraviolet radiation through the irradiation chamber.

Description

The invention relates to a UV semiconductor light source irradiation device in which a medium conducted through an irradiation chamber efficiently interacts with the emitted UV radiation and thus can be changed, and a method which efficiently enables said irradiation. The UV semiconductor light source irradiation device according to the invention can be used, for example, for the sterilization of flowing media, but also as a reactor for chemical and / or biochemical reactions and / or for generating physically excited states of molecules and / or atoms.

It has long been known to use ultraviolet (UV) radiation to kill germs. This principle is used for example in water treatment plants. Usually a special burner produces short-wave UV radiation that kills germs in the water. The principle of action is based on the fact that the short-wave UV radiation penetrates the cell nuclei of bacteria and destroys their genetic material, so that they can not multiply. The use of UV radiation especially for sterilizing drinking water is considered to be particularly environmentally friendly and health-friendly, because in the water treatment process no chemicals such as chlorine are necessary, which can pollute the drinking water and / or wastewater.

However, mercury vapor low pressure, medium pressure, high pressure and maximum pressure lamps are usually used as burners for generating the UV radiation. Even the use of highly toxic mercury makes the environmental friendliness of this technology seem at least relatively, and the power consumption of these lamps is very high, if the required power density of UV radiation is to be generated. Likewise, the known mercury vapor lamps act approximately as Lambertian radiators, d. H. They radiate the emitted radiation approximately equally into the entire space without having a specific preferred direction. For this reason, systems with UV lamps in water treatment plants are constructed such that the UV radiation source is arranged in a quartz tube coaxially housed in a conduit, so that the water to be treated flows as evenly along the outer circumferential surface of the quartz tube in its longitudinal direction. The quartz tube itself is required because it must be transparent to the emitted UV radiation. But it is very expensive to manufacture and to buy.

With the increasing availability of UV LEDs, efforts have been made to replace the known UV lamps and burners with these LEDs. So revealed the US 2005/0242013 A1 Sterilization chambers with a plurality of UV LEDs, which are mounted in an irradiation chamber and where the medium to be irradiated flows past. The radiation emitted by the UV LEDs passes through the medium to be irradiated perpendicular to its flow direction, so that the residence time of a located in the medium and to be sterilized by the interaction with the UV radiation element in the beam region of a UV-LED is low. In order to achieve a sufficient interaction probability and thus efficiency of the proposed sterilization chambers, a plurality of UV LEDs are mounted in the chamber. However, the flow of the medium in the chamber is accelerated by the reduction of the available cross-section, which further reduces the interaction probability.

The US 7,520,978 B2 describes another UV LED irradiation device. A plurality of UV LEDs are mounted on one side on support elements, which have small passage openings for the medium to be conducted through the chamber. The support elements are mounted within the irradiation chamber so that the UV LEDs irradiate each other and so the radiation intensity in the irradiation chamber is as high as possible. Compared with the supply lines, the cross-sectional area of the irradiation chamber is very large, the flow velocity of the medium conducted through the chamber is reduced.

These constructions have several disadvantages. On the one hand, energy consumption increases with the number of UV LEDs used. Furthermore, UV LEDs are simply expensive, so that the proposed solutions are also very expensive to manufacture. And on the other hand, the change of the flow cross-section in the chamber in addition to an increase in the required space to a reduced throughput can lead to unwanted side effects such as unpleasant noise developments. However, many new applications call for a high efficiency of such irradiation devices with a simultaneously compact design. Also disturbing noise developments, for example, in the sterilization of the air supply of vehicles such as automobiles, passenger aircraft and / or trains are intolerable.

The object of the invention is therefore to provide an irradiation device based on UV semiconductor light sources, which has a small installation space and high energy efficiency, as well as an efficient method for irradiating flowing media with UV radiation.

The object is achieved by the UV semiconductor light source irradiation device according to the main claims. Preferred embodiments will be apparent from the dependent claims.

A UV semiconductor light source irradiation device according to the invention contains at least one UV semiconductor light source and an irradiation chamber which has a reflectance of at least 95%. For the purposes of the invention, UV semiconductor light source means any semiconductor light source which emits electromagnetic radiation in the ultraviolet (abbreviated UV) spectral range. The ultraviolet spectral range includes wavelengths of about 400 nm to about 3 nm. The preferred range, which has proven to be particularly advantageous for the cell inactivation, is about 200 nm to 280 nm. UV semiconductor light sources according to the invention are in particular Light-emitting diodes (Light Emitting Diode, abbreviated LED or UV-LED, if they emit UV radiation) understood. However, it is also possible to use UV semiconductor lasers, in particular UV diode lasers.

The irradiation chamber defines a volume through which a medium to be irradiated can be passed. Preferably, it is tubular. The tube may have, for example, a circular, an oval, a rectangular or a polygonal diameter geometry.

The flow of the medium to be irradiated in the irradiation chamber takes place along a main flow direction R. The main flow direction R represents the averaged path of the individual elements of the flowing medium to be irradiated through the irradiation chamber and thus represents an idealized direction which is not necessarily of all the elements of the flowing one irradiated medium is observed. The main flow direction R adjusts itself during operation of the UV semiconductor light source irradiation device according to the invention when the medium to be irradiated is passed through the irradiation chamber.

The at least one UV semiconductor light source according to the invention is mounted so that in the operating state, d. H. when a medium to be irradiated flows through the irradiation chamber and when the UV semiconductor light source is turned on and emits radiation, the primary radiation of the UV semiconductor light source at an average angle α greater than 60 °, and preferably less than 90 °, hereinafter called angle condition the medium to be irradiated passes. α is measured from the main flow direction R and at that beam of the beam path, which first intersects the vector of the main flow direction R.

UV semiconductor light sources usually emit light not only in one direction, but the emission takes place in an angular distribution. Therefore, in the present specification, the term of the primary radiation and the averaged angle α is used. Primary radiation is the radiation flow of the UV semiconductor light source integrated within the irradiation chamber over all solid angles of the emission, so that the direction of the primary radiation in simplified terms corresponds to the direction of the light flux averaged in the irradiation chamber, the radiation emission of the UV semiconductor light source. For reasons of clarity, therefore, α is also spoken of the averaged angle.

The definition of the primary radiation applies to every partial beam that is effective in the operating state in the irradiation chamber. If the radiation of the UV semiconductor light source is split, for example, by a beam splitter or another suitable optical element into two sub-beams, the primary radiation of each of these sub-beams passes through the main flow direction R under the aforementioned angle condition for the averaged angle α.

The mode of operation of the irradiation device according to the invention is based on the fact that the radiation of the UV semiconductor light source, if it is irradiated into the irradiation chamber under the aforementioned angle conditions, can be reflected several times in the irradiation chamber, so that even with a low absorption of the medium to be irradiated by the multiple reflection a sufficiently large optical path length is provided within the irradiation chamber, so that a sufficiently large interaction probability of the UV quantum emitted by the semiconductor light source with the corresponding. Element of the medium to be irradiated is achieved. For this reason, the degree of reflection of the inner wall of the irradiation chamber according to the invention is at least 95%. The degree of reflection indicates how much of the intensity of the emitted primary radiation after the first reflection on the inner wall of the irradiation chamber is still present, with no to be irradiated in this measurement Medium is in the irradiation chamber or such a medium is used, which does not substantially absorb the radiation emitted by the UV semiconductor light source radiation.

To achieve the degree of reflection, the inner wall may preferably be mirrored. Methods for mirroring, for example by metal evaporation, are well known. The irradiation chamber itself may preferably consist of metals, plastics or glass, or of combinations of these materials.

In contrast to the UV-LED irradiation devices known from the prior art, which in principle simulate the beam paths and action mechanisms known from mercury vapor lamps, the irradiation device according to the invention uses the emission characteristic of semiconductor light sources and the optical beam paths possible therewith in order to achieve the object. In operation, semiconductor light sources emit radiation at narrow angles of radiation, that is, in a small solid angle range, because optical elements are mounted near LEDs in close proximity to the emission surface, and semiconductor lasers emit highly forwardly directed radiation with little divergence. By contrast, LEDs without optical elements mounted directly in front of them have the behavior of a Lambertian emitter, which emits in large solid angle ranges. Nevertheless, the light emitted by LEDs can be well collimated.

The radiation directed to the front increases the power density per unit area of an irradiated measuring surface. The comparison to UV low-pressure mercury lamps shows that already widespread blue LEDs with an emission at 450 nm have a higher power density. Thus, the power density of UV low-pressure mercury lamps is about 1 mW per square millimeter, while that of blue LEDs with an emission at 450 nm is about 1000 mW per square millimeter. Even today's UV LEDs achieve much higher power densities than UV mercury lamps. However, the higher power densities of available semiconductor light sources are not exploited by the prior art UV LED irradiators.

Likewise, in the UV-LED irradiation devices known from the prior art, it is possible for the radiation emitted by an LED to hit this LED again by reflection, or even other LEDs are irradiated directly. This can on the one hand reduce the overall efficiency of the system, but also lead to damage and / or reduction of the life of the LEDs. In a preferred embodiment of a UV semiconductor light source irradiation device according to the invention, the at least one UV semiconductor light source is therefore arranged such that in the operating state less than 5% of the radiation emitted by the at least one UV semiconductor light source from the inner wall of the irradiation chamber is returned to this UV radiation. Semiconductor light source hits. The emitted radiation is therefore reflected, as it were, forward into the irradiation chamber, wherein the radiation chamber is designed so that a multiple reflection of the emitted radiation on the inner wall of the irradiation chamber is possible.

The at least one UV semiconductor light source may be mounted within the irradiation chamber. Suitable current feedthroughs can be guided through the wall of the irradiation chamber. For example, glass-metal bushings have proven particularly suitable in which current conductors made of metal are melted in an insulating material made of glass and / or sintered.

However, the at least one UV semiconductor light source is particularly preferably located outside the irradiation chamber and the radiation emitted by the at least one UV semiconductor light source can be coupled into the irradiation chamber by at least one window that is largely transparent to this radiation. For the purposes of the invention, largely permeable means that the window is designed with regard to its material and its shape so that the emitted UV radiation is not or at most absorbed only slightly by the window, so that a large part of the radiation power passes through the window into the irradiation chamber can. Suitable materials are, for example, UV-transparent glasses and / or quartz. The arrangement of the at least one UV semiconductor light source outside the irradiation chamber has the advantage that it can be exchanged and / or maintained more easily. In addition, it is the direct influences such as pressure, temperature and / or aggressive components of the medium to be irradiated, which is passed through the irradiation chamber, extracted. The arranged outside the irradiation chamber UV semiconductor light source may be mounted to achieve the aforementioned angle of the primary radiation by appropriate measures already at the appropriate angle.

The entrance window can be most easily formed in this case, for example in the form of a plane-parallel disk or plate. If the irradiation chamber is made of a metal, the entrance window can be connected to the irradiation chamber, for example by glass solders. This is a Pressling comprising the ground glass solder, if necessary. is mixed with an organic binder, placed in the form of a frame on the entrance window or around the opening in the irradiation chamber and / or applied to this in the form of a paste. By heating the components irradiation chamber, entrance window and glass solder a bond between these components can be achieved, which may even be hermetic. Hermetically means that virtually no medium can pass through the joint. Glass solder joints can even pass helium leak tests and are also characterized by extremely high durability, because they are not prone to high temperatures, UV radiation, disposition against chemically aggressive media, etc. If lower requirements are placed on the hermeticity of the connection and / or its durability, it is also possible in the sense of the invention, however, that the entrance window can be fixed with the aid of gluing methods, e.g. B. is connected to the irradiation chamber with organic adhesives.

An alternative embodiment provides that the radiation emitted by the UV semiconductor light source radiation is split by an optical element, so that the aforementioned angle condition of the passage of the primary radiation to the main flow direction R can be met. In this case, the UV semiconductor light source may be mounted substantially colinear or perpendicular to the longitudinal axis of the irradiation chamber and preferably mounted outside the irradiation chamber. In this case, the described optical element can simultaneously act as an entrance window, but it is also possible to design it as a separate element or as an element connected to the entrance window. It is likewise possible to realize the colinear or vertical arrangement with a UV semiconductor light source located within the irradiation chamber.

It is likewise possible to use more than one UV semiconductor light source in the irradiation device according to the invention. The UV semiconductor light sources used may preferably have their spectral emission maxima at different wavelengths. This may have advantages for eliminating a variety of different bacteria present in the medium conducted through the irradiation chamber and / or for inducing chemical reactions stepwise.

Due to the targeted beam guidance, the UV semiconductor light source irradiation device according to the invention is characterized by an efficient utilization of the radiation emitted by the semiconductor light sources. To characterize the efficiency of an irradiation device, the figure of merit FOM ₁ can be used. FOM ₁ can be calculated by FOM ₁ = dose · current / power

Dose stands for the total dose in J m ^-2 , which corresponds to the amount of radiation introduced over time. The total dose required for effective UV sterilization is 400 J m ^-2 , according to the US National Science Foundation and US Environmental Protection Agency, respectively. This dose is preferably at least achieved by the irradiation devices according to the invention.

Current stands for the quantity of medium which can be conducted through the irradiation chamber and thus represents the volume flow in m ^-3 s ^-1 .

Power stands for the radiation power emitted by the UV semiconductor light sources in W.

The unit of FOM ₁ is meters. The figure of merit FOM ₁ is high when, with the radiation power of the semiconductor light sources emitted small, a high dose is achieved in a large current of the medium conducted through the irradiation chamber. If a constant dose is used for the dose of the previously mentioned recommended value of 400 J m ^-2 , high values of FOM _{1 result} if a high volume flow with low radiation power can be realized in order to achieve the said total dose. This is achieved as described by a large path length of the photons in the irradiation chamber.

In terms of this figure of merit FOM ₁ , however, a good system can be realized very easily, namely by means of a very large irradiation chamber. Even at low flow velocities, the volume flow of the medium conducted through the irradiation chamber can be very large. However, such a large-volume embodiment is not a preferred embodiment of the invention. A preferred embodiment, however, can be used under limited spatial conditions. In such a case, the volume of the irradiation chamber must also be limited and in a decisive for this case figure of merit FOM ₂ this is also to be considered. FOM ₂ is therefore calculated by FOM ₂ = dose · current / power · volume

Volume represents the volume of the irradiation chamber. The unit of FOM ₂ is m ^-2 . A reduced volume of the irradiation chamber thus improves FOM ₂ . The aim is to achieve the highest possible values for FOM ₂ . In a preferred embodiment, the UV semiconductor light source irradiation device according to the invention has values for FOM ₂ which are greater than 1000 m ^-2 , particularly preferably greater than 5000 m ^-2 , very particularly preferably greater than 10000 m ^-2 and particularly particularly preferably greater as 15000 m ^-2 .

Table 1 compares the FOM ₂ values known and achievable according to the prior art with those achievable by the invention. Table 1 system cross-section length power FOM ₂ conventional 9 cm (round) 0,94 m 11.7 W 3 m ^-2 LED p. D. T. 2 × 2 cm 0.25 m 10.0 W 200 m ^-2 LED variant 1 1 × 1.4 cm 0.38 m 0.67 W 5700 m ^-2 LED variant 2 1 × 1.4 cm 0.38 m 0.2 W 19000 m ^-2

In the overall comparison and the calculation of FOM ₂ is assumed by a flow rate or short flow of the medium to be irradiated of 0.5 l / s. The total dose required for effective UV sterilization is 400 J m ^-2 as described.

Cross section is in Table 1 for the geometry of the cross-sectional area. From this the value of the cross-sectional area can be calculated and the product of this value can be used to calculate the chamber volume or, in short, the volume.

The required power of UV radiation is in principle dependent on the free path length of the UV quanta in the irradiation device. Power = (dose · current) / (free path) applies. Preference is given to using radiation in the UV-C spectral range which covers a wavelength range of 100 nm to 280 nm according to customary diction.

The first column lists the compared irradiation systems. "Conventional" here stands for a UV disinfection system in which a low-pressure lamp is used. The diameter of the tubular irradiation chamber is 9 cm, its length 0.94 m. Coaxially inside the low pressure lamp is attached. The free path length for a UV quantum is about 0.2 m in such a system, the required power of UV radiation is 11.7 W. Thus, the value for FOM ₂ for such a system is calculated to be 3 m ^-2 , This means that the conventional system is very inefficient.

The second line shows the performance data of an LED disinfection system known from the prior art ("LED S. d. T."). It is similar to the one in 1 shown system, except that the medium to be irradiated is guided in a channel past the LEDs. The studied system LED S. d. T consists of a square tube with a cross-sectional area of 0.02 m to 0.02 m and a length of 0.25 m. An inside of the tube, ie a rectangular area, is filled with UV LEDs. Reflections on the inside are not used. The free path for a UV quantum is 0.02 m in such a system. The residence time of an element of the medium to be irradiated in the chamber is calculated from the quotient of chamber volume and volume flow and is therefore 0.2 s with the values indicated. The power density in this chamber is calculated from the quotient of the required dose and the residence time to 2000 W m ^-2 . The required power to be used as power in the formula of FOM ₂ is the product of power density and luminous area, ie 2000 W m ^-2 .0.02 m Value for FOM ₂ of 200 m ^-2 .

The embodiment of the invention "LED variant 1" is based on a degree of reflection of the inner wall of the irradiation chamber of 95%. The irradiation chamber has a circular cross-sectional area with a diameter of 1.4 cm and a length of 0.38 m, so it has approximately the shape of a thin tube. The free path of UV quanta due to the reflectivity on the inner wall 0.3 m. The radiation power required in this irradiation device according to the invention is only 0.67 W, thus achieving a value of FOM ₂ of 5700 m ^-2 .

Another variant "LED variant 2" is based on a reflectance of 99% and the same chamber geometries as in variant 1 and a free path of the UV quanta of 1 m. The required radiant power in this system is only 0.2 W, and FOM ₂ has a value of 19000 m ^-2 .

This proves that in the UV semiconductor light source irradiation device according to the invention, thanks to the targeted beam guidance, the emitted UV radiation can interact much more efficiently with the medium to be irradiated than can the irradiation devices proposed in the prior art.

Particularly preferably, it is provided that two UV LEDs with emission maxima at 268 nm and 282 nm are arranged in the vicinity of the inlet opening of the irradiation chamber. By using UV LEDs with different spectral layers of the emission maxima, an increased effect can be achieved, in particular with different germs present in the medium to be conducted through the irradiation chamber. At most four UV LEDs are preferably installed in a UV semiconductor light source irradiation device according to the invention.

In a further preferred embodiment of the UV semiconductor light source irradiation device according to the invention, the cross-sectional area of the irradiation chamber has a value which substantially corresponds to the value of the cross-sectional area of the inlet opening in the irradiation chamber and substantially to the value of the outlet opening of the irradiation chamber. This means that preferably no substantial cross-section reduction of the lines of the system in which it is integrated by the irradiation chamber occurs. It can thereby be achieved that the medium which can be conducted through the irradiation chamber can be conducted through the irradiation chamber at a substantially same flow rate as in the supply and discharge regions. As a result, a good flow of the medium to be irradiated is ensured by the irradiation chamber and disturbing side effects, such as a noise and or vibration, largely avoided.

The UV semiconductor light source irradiation device according to the invention is preferably designed such that air and / or water can be conducted through it as a medium to be irradiated. Mixtures of both media are also possible, for example in the form of water vapor. Of course, however, it is likewise encompassed by the invention that other gaseous or liquid media can likewise be conducted through the irradiation chamber and can be irradiated by the at least one UV semiconductor light source. Also solutions of solids in liquids and / or aerosols are included.

Particularly preferably, the radiation emitted by the at least one UV semiconductor light source can be monitored by means of a sensor after a plurality of reflections on the inner wall of the irradiation chamber, i. H. be detected, which is associated with the at least one UV semiconductor light source. In this way, information about the degree of reflection of the irradiation chamber and / or the absorption of the medium located in the irradiation chamber can be made obtainable during operation of the irradiation device according to the invention, but also about the operability of the at least one UV semiconductor light source itself and / or the degree of contamination of the irradiation chamber. This can indicate the maintenance status of the irradiation device and in this way the use in particularly vulnerable means of transport such. As aircraft, but also in mass transit such as automobiles or trains easier.

Even better monitoring of the operating state is possible if more than one sensor is used for monitoring. If the three parameters of power of the UV semiconductor light source, turbidity of the medium to be irradiated and reflectivity of the inner wall irradiation chamber are to be detected, a preferred embodiment of the UV semiconductor light source irradiation device according to the invention provides that a sensor is located at the UV semiconductor light source and there Detected by her radiated power detected, another sensor at the first reflection point on the inner wall measures the turbidity of the medium through the chamber and another sensor at the end of the reflection chain makes the reflectivity and thus pollution and / or damage to the inner wall of the irradiation chamber noticeable.

An inventive method is based on the principles of action of the described irradiation device according to the invention. It provides that the medium to be irradiated along the main flow direction R is passed through an irradiation chamber and irradiated with UV radiation emitted by at least one UV semiconductor light source. The pre-defined primary radiation of the at least one UV semiconductor light source occurs at an angle α of greater than 60 ° and preferably less than 90 ° measured The main flow direction R through the medium to be irradiated and the inner wall of the irradiation chamber has for the emitted radiation of the UV semiconductor light source also a defined degree of reflection of at least 95%, so that the radiation emitted by the UV semiconductor light source is reflected multiple times within the irradiation chamber. All embodiments which are preferred with respect to the irradiation device also apply to the method according to the invention.

The irradiation device according to the invention is preferably used for the sterilization and / or disinfection of media conducted through the irradiation chamber. The mode of action of sterilization and / or disinfection has been described previously. Because of its compactness and efficiency, the disinfection and / or sterilization irradiation device according to the invention can preferably be used in vehicles, for example in aircraft, automobiles (buses, cars and trucks), ships, submarines or trains, for the treatment of the air in the passenger cabin and / or in cab.

Another preferred application is the use of the irradiation device according to the invention as a reactor. In such a chemical and / or biochemical reactions are induced by the emitted UV radiation. Such reactions are in particular photoinduced reactions such as, for example, the crosslinking of plastics or the breaking down of chemical bonds.

Another field of application is the physical excitation of molecules and / or atoms into a higher state of physical excitation. This can be used, for example, to efficiently generate singlet oxygen, also known as "active oxygen". Because direct excitation by absorption of triplet ground state oxygen to electronically excited singlet oxygen can only be extremely inefficient due to quantum mechanical selection rules, sensitizers are used. These are usually singlet ground state molecules, which are brought by absorption into an electronically excited singlet and / or triplet state. By collisions with ground state oxygen, an energy transfer to the oxygen can occur, so that electronically excited singlet oxygen ( ¹ Δ _g and ¹ Σ _g ⁺ ) can arise. The most efficient sensitizers achieve quantum efficiencies of nearly 1, such as phenalenone, phenazine and benzanthrone.

One of the best known sensitizers is tetraphenylporphyrin (and its derivatives). It is used for photodynamic cancer therapy, in which the property of singlet oxygen is exploited as a potent cytotoxin, destroying the tissue of the cancer. The suitable sensitizers usually have a strong absorption in the UV spectral range, so that the irradiation device according to the invention can advantageously be used for the production of singlet oxygen. Domestic applications can also be realized in this way, for example, cleaning baths for proteses and hygiene articles such as toothbrushes and razors.

The invention will be explained in more detail with reference to the figures. Show it

1 : A UV-LED irradiation device according to the prior art.

2 : Another UV-LED irradiation device according to the prior art.

3 A UV semiconductor light source irradiation device according to the invention.

4 An alternative embodiment of a UV semiconductor light source irradiation device according to the invention.

5 : A further alternative embodiment of a UV semiconductor light source irradiation device according to the invention.

6 : A further alternative embodiment of a UV semiconductor light source irradiation device according to the invention.

7 : A further alternative embodiment of a UV semiconductor light source irradiation device according to the invention.

8th : A further alternative embodiment of a UV semiconductor light source irradiation device according to the invention.

All figures are schematic and serve to illustrate. The dimensions and / or proportions of the drawings need not be the same as the actual devices.

1 represents one of the US 2005/0242013 A1 known sterilization chamber with a plurality of UV LEDs ( 1 As described above, the medium to be irradiated flows in the main flow direction R at the UV LEDs ( 1 ), whereby the UV LEDs ( 1 ) radiation passes through the medium to be irradiated perpendicular to its main flow direction (R). The flow of the medium in the chamber ( 2 ) available cross-section is in the chamber ( 2 ), so that the flow velocity in the two branches increases in comparison to the supply line. This reduces the likelihood of interaction and requires a higher number of expensive UV LEDs ( 1 ) are compensated. Multiple reflections in the chamber are not intended to prevent the UV LEDs ( 1 ) are beaming at each other. Furthermore, noise generation is to be expected from the increase in the flow velocity, which is likewise undesirable.

2 shows the in the US 7,520,978 B2 proposed UV LED irradiation device. A variety of UV LEDs ( 1 ) are on one side on support elements ( 20 ), which passage openings for the through the chamber ( 2 ) have to be conducted medium. The support elements are within the irradiation chamber ( 2 ) so that the UV LEDs ( 1 ) irradiate each other and so the radiation intensity in the irradiation chamber ( 2 ) is as high as possible. Compared with the supply lines, the cross-section of the irradiation chamber ( 2 ) very large, the flow velocity through the chamber ( 2 ) conducted medium is reduced. It is an open question whether on average the main flow direction (R) sets or mainly a turbulence takes place. Despite the reduced flow rate, this chamber ( 2 ) come to unwanted noise because that in the chamber ( 2 ) entering medium can expand and / or by the passage through the narrow passage openings, the support elements and / or the wall ( 3 ) can get into vibration. In any case, the illustrated chamber has a large volume, so that the proposed UV-LED irradiation device can not have a compact design.

Of the US 7,520,978 B2 it can also be seen that the inner wall ( 3 ) reflective to that of the UV LEDs ( 1 ) emitted radiation can be. Due to the carrier elements ( 20 ) and the radiation characteristic of the UV LEDs ( 1 ) it can not lead to multiple reflections in the chamber ( 2 ) because the emitted radiation is emitted very rapidly by the carrier elements ( 20 ) and / or the UV LEDs ( 1 ) is absorbed. Also by this is the interaction probability of the emitted UV radiation with that through the chamber ( 2 ) medium, so that a large number of UV LEDs ( 1 ) is provided.

In 3 a UV semiconductor light source irradiation device according to the invention is shown schematically. In this embodiment, the at least one UV semiconductor light source ( 1 ), preferably a UV LED ( 1 ), outside the irradiation chamber ( 2 ) appropriate. That of the UV semiconductor light source ( 1 ) emissive radiation is in the operating state by an optical element ( 4 ) through the largely transparent to the radiation window ( 5 ) into the irradiation chamber ( 2 ) coupled. The window ( 5 ) can be applied to the wall using the methods described above ( 3 ) of the irradiation chamber.

The beam path of the UV semiconductor light source ( 1 ) is schematically symbolized in all figures by the arrows shown. In 1 is that of the UV semiconductor light source ( 1 ) emits radiation as divergent. The optical element ( 4 ) preferably parallelizes the radiation. The optical element ( 4 ) can be directly on the UV semiconductor light source ( 1 ) or separately. It is also possible that the optical element ( 4 ) is another element which, in combination with directly on the UV semiconductor light source ( 1 ) attached further or other optical elements acts. Its task is to provide at least one suitable, preferably largely collimated, beam of primary radiation ( 10 ) into the irradiation chamber ( 2 ).

The irradiation chamber has a nearly same cross-section as the inlets and outlets ( 30 ). In the present case, the irradiation chamber ( 2 ) the shape of a tube and the medium to be irradiated is in the operating state along the main flow direction R also shown as arrow through the irradiation chamber ( 2 ). Preferably, the flow is laminar. The inlets and outlets ( 30 ) can be provided with a sleeve as shown, to the irradiation chamber ( 2 ) with the inlets and outlets ( 30 ) to make connectable. It is also possible to use the irradiation chamber ( 2 ) with a sleeve. The sleeve can be made in one or more parts. Of course, any other suitable embodiment of the connection is equally possible and encompassed by the invention.

According to the illustrated embodiment, the UV semiconductor light source ( 1 ) at such an angle outside the irradiation chamber ( 2 ) that the emitted primary radiation ( 10 ) of the UV semiconductor light source ( 1 ) in the operating state through the chamber ( 2 ) flowing medium at an angle α of greater than 60 ° passes. α is measured from the main flow direction R from. According to the angle convention, the smaller angle is called α, so the minor angle is less than 120 °. In the present case, that of the UV semiconductor light source ( 1 ) emissable primary radiation ( 10 ) as a radiation beam, which according to the 3 in the direction of the main flow direction R in the irradiation chamber ( 2 ) is reflected back and forth. But it is also possible that the main flow direction R runs in the opposite direction or that the at least one UV semiconductor light source ( 1 ) at the other end of the irradiation chamber ( 2 ) is mounted so that in the operating state, the emitted radiation runs against the main flow direction.

The multiple reflection is an essential element of the UV semiconductor light source irradiation device according to the invention. To reach them, the inner wall ( 3 ) of the irradiation chamber ( 2 ) have been designed by suitable measures previously described so that the radiation can be reflected. The reflectance of the inner wall ( 3 ) of the irradiation chamber ( 2 ) is at least 95% according to the invention as already described. The multiple reflection capability is determined according to the method described in 3 embodiment achieved by the fact that the at least one UV semiconductor light source ( 1 ) outside the irradiation chamber ( 2 ) and the emitted radiation from the window ( 5 ) runs away. In order to further increase the overall reflectance of the chamber and thus the ability to multiple reflection, it may also be provided to use the permeable window (FIG. 5 ) semi-permeable, so that although the emissive radiation from the UV semiconductor light source ( 1 ) in the direction of the irradiation chamber ( 2 ) but not from the interior of the chamber ( 2 ) can emerge again. At this point it should be emphasized again that in the measurement of the total reflectance no medium to be irradiated in the chamber ( 2 ), so the reflectance is the ability of the inner wall ( 3 ) indicating that the at least one UV semiconductor light source ( 1 ) Emitted light inside the chamber ( 2 ) to reflect.

In 4 is a variation of in 3 illustrated embodiment shown. The optical element ( 4 ) is in the wall ( 3 ) of the irradiation chamber ( 2 ) used. As a result, the optical element ( 4 ), so to speak, a functionalized entrance window ( 5 ). Again, it is possible that the optical element ( 4 ) is used together with optical elements not shown. According to the in 4 illustrated embodiment, the optical element ( 4 ) a special shape, which makes it possible, that of the UV semiconductor light source ( 1 ) emitted radiation not only in principle to parallelize, but also split into two partial beams. Each of these partial beams passes in the operating state that along the main flow direction R through the irradiation chamber ( 2 ) conductive medium to be irradiated at an angle α greater than 60 °. The primary radiation ( 10 . 11 ) is to be regarded individually for each of the partial beams as described with respect to their definition, and for each of the partial beams the condition α> 60 ° and preferably α ≦ 90 ° is satisfied.

Thus, it is possible to use the optical element ( 4 ) in the middle of the irradiation chamber ( 2 ) and the at least one UV semiconductor light source ( 1 ) perpendicular to the axis of the irradiation chamber ( 2 ). The angle condition for irradiation is determined by the shape of the optical element (FIG. 4 ) reached. That of the UV semiconductor light source ( 1 ) emitted primary radiation ( 10 . 11 ) runs in two partial beams, once against the main flow direction R, once with the main flow direction R. In this way, results in a particularly compact and easy to install UV semiconductor light source irradiation device.

In the in 5 embodiment shown again in terms of. 4 described specially shaped optical element ( 4 ) Use. This time, however, it is colinear to the axis of the irradiation chamber ( 2 ) attached to this. The shape of the irradiation chamber ( 2 ) is reminiscent of an angular offset piece. That through the chamber ( 2 ) conductive medium to be irradiated passes through the irradiation chamber ( 2 ) now not colinear, so that the main flow direction R opposite the wall ( 3 ) of the irradiation chamber ( 2 ) is inclined. The cross-sectional area of the irradiation chamber ( 2 ) is nevertheless essentially the same size as the cross-sectional area of the inlet and outlet ( 30 ).

The optical element ( 4 ) in this embodiment, in principle, again parallelizes that of the UV semiconductor light source ( 1 ) emitted radiation and splits it into 2 partial beams, which two branches of primary radiation ( 10 . 11 ) form. Each of these branches passes through the main flow direction R at the angle α for which the said angle condition applies according to the invention.

6 again shows a variation of in 4 featured embodiment in which the UV semiconductor light source ( 1 ) a sensor ( 6 ) assigned. The sensor is according to this figure outside the Irradiation chamber ( 2 ) appropriate. So that the emitted radiation after a few reflections on the inner wall ( 3 ) the chamber can hit the sensor is in the wall ( 3 ) and in front of the sensor ( 6 ) another radiation permeable window ( 5 ) appropriate. The sensor can preferably measurable the intensity of the reflected radiation and thus conclusions about the total reflectance of the irradiation chamber ( 2 ) and thus also on their degree of pollution made recoverable. Therefore, an evaluation electronics is usually associated with the sensor in the specific component, which preferably also influences the intensity of the light emitted by the UV semiconductor light source ( 1 ) can take emitted radiation. This embodiment is particularly suitable when passing through the chamber ( 2 ) to be conducted medium is particularly aggressive and / or has high temperatures.

7 represents a variation of in 6 described embodiment in which the sensor ( 6 ) in the wall ( 3 ) of the irradiation chamber ( 2 ) is attached. In this way, on the window ( 5 ) are waived.

In 8th again is a variation of the embodiment of FIG 6 and 7 represented by the sensor ( 6 ) inside the irradiation chamber ( 2 ) is located. An implementing element ( 61 ) is in the wall ( 3 ) the chamber ( 2 ) and closes them. In the implementing element ( 61 ) are the line elements ( 62 ) are inserted or lead through this, in order to supply the sensor with electric current and / or to make the measurement signals of him available. The line elements ( 62 ) are preferably connected to the evaluation electronics associated with the sensor as described. As also already described, the bushing element ( 61 ) preferably a glass-metal passage, which is particularly suitable when the wall ( 3 ) of the irradiation chamber ( 2 ) is made of a metal.

In addition to the mentioned UV LEDs ( 1 ) can in all described embodiments, esp. In accordance with the 3 to 8th , also UV diode laser ( 1 ) are used.

The described UV semiconductor light source irradiation device according to the invention is due to the targeted beam guidance and the multiple reflection in the irradiation chamber ( 2 ) with a few UV semiconductor light sources ( 1 ) out. This makes them cost effective both in manufacturing and in operation. Due to the exploitation of the appropriate beam guidance, it is also compact and the size of the cross-sectional areas of the irradiation chamber ( 2 ) can be essentially that of the inlets and outlets ( 30 ), so that by the Chamber ( 2 ) guided medium in the operating state does not cause any significant noise. All this makes the UV semiconductor light source irradiation device according to the invention user-friendly and usable also in many non-industrial applications, in particular in means of transport and in the vicinity of passengers.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2005/0242013 A1 [0004, 0061]
• US 7520978 B2 [0005, 0062, 0063]

Claims (10)

UV semiconductor light source irradiation device comprising at least one UV semiconductor light source ( 1 ) and an irradiation chamber ( 2 ), through which a medium to be irradiated can be conducted along the main flow direction R, wherein the light emitted by the UV semiconductor light source ( 1 ) emitted primary radiation ( 10 . 11 ) in the operating state at an averaged angle α of greater than 60 ° to the main flow direction R passes through the medium to be irradiated and the inner wall ( 3 ) of the irradiation chamber ( 2 ) has a reflectance of at least 95% for the emitted radiation of the UV semiconductor light source, so that the radiation emitted by the UV semiconductor light source ( 1 ) emitted radiation several times within the irradiation chamber ( 2 ) can be reflected. UV semiconductor light source irradiation device according to claim 1, wherein in the operating state less than 5% of that of the UV semiconductor light source ( 1 ) emitted radiation from the inner wall ( 3 ) of the irradiation chamber is reflected back to the UV semiconductor light source. UV semiconductor light source irradiation device according to at least one of the preceding claims, wherein the UV semiconductor light source ( 1 ) is a UV LED or a UV semiconductor laser. UV semiconductor light source irradiation device according to at least one of the preceding claims, wherein the UV semiconductor light source ( 1 ) is arranged outside the irradiation chamber and that of the UV semiconductor light source ( 1 ) emitted radiation through a largely transparent for this radiation entrance window ( 5 ) and / or an optical element ( 4 ) into the irradiation chamber ( 2 ) can be coupled. UV semiconductor light source irradiation device according to at least one of the preceding claims, wherein the irradiation device has a figure of merit FOM ₂ which is greater than 1000 m ^-2 , preferably greater than 5000 m ^-2 , particularly preferably greater than 10000 m ^-2 , very particularly preferably greater than 15,000 m ^-2 , where FOM _{2 is} calculated by FOM ₂ = (dose · current) / (power · volume). UV semiconductor light source irradiation device according to at least one of the preceding claims, wherein the cross-sectional area of the irradiation chamber ( 2 ) has a value which substantially corresponds to the value of the cross-sectional area of the inlet opening in the irradiation chamber and substantially the value of the outlet opening of the irradiation chamber, so that through the irradiation chamber ( 2 ) is conductible medium at a substantially same flow rate as in the supply and discharge areas through the irradiation chamber. UV semiconductor light source irradiation device according to at least one of the preceding claims, wherein the light emitted by the irradiation chamber ( 2 ) is conductive medium substantially air and / or water. UV semiconductor light source irradiation device according to at least one of the preceding claims, wherein the at least one UV semiconductor light source ( 1 ) at least one sensor ( 6 ), which in the operating state, the intensity of the of the UV semiconductor light source ( 1 ) emitted radiation after a plurality of reflections on the inner wall ( 3 ) of the irradiation chamber ( 2 ) and thus preferably information about the degree of reflection of the irradiation chamber ( 3 ) and / or the absorption of the in the irradiation chamber ( 3 ) is made recoverable medium. Method for irradiating through an irradiation chamber ( 2 ) guided along the main flow direction R media with UV radiation, wherein the UV radiation from at least one UV semiconductor light source ( 1 ) is emitted whose primary radiation ( 10 . 11 ) passes through the medium to be irradiated at an angle α greater than 60 ° to the main flow direction R, and the inner wall ( 3 ) of the irradiation chamber ( 2 ) for the emitted radiation of the UV semiconductor light source ( 1 ) has a reflectance of at least 95%, so that that of the UV semiconductor light source ( 1 ) emitted radiation during irradiation multiple times within the irradiation chamber ( 2 ) is reflected. Use of a UV semiconductor light source irradiation device according to at least one of claims 1 to 8 for the sterilization and / or disinfection and / or induction of chemical and / or biochemical reactions and / or physical excitation of molecules and / or atoms in a higher physical excited state ,

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