DE102018125596A1 - Device and method for sterilizing a gas or gas mixture with UVC radiation - Google Patents

Abstract

In a first aspect, the invention relates to a device for sterilizing a gas or gas mixture with UVC radiation, the device having a housing which is set up for irradiating the gas or gas mixture and has at least one inlet opening and at least one outlet opening. At least one UVC emitter is arranged in the housing and at least the part of the housing which is exposed to UVC radiation is made of aluminum or is coated with aluminum. In a second aspect, a method for disinfecting a gas or gas mixture with UVC radiation is provided in that the gas or gas mixture is passed through the housing in the longitudinal direction to at least one UVC emitter arranged in the housing.

Description

In a first aspect, the invention relates to a device for sterilizing a gas or gas mixture with UVC radiation, the device having a housing which is set up for irradiating the gas or gas mixture and has at least one inlet opening and at least one outlet opening. At least one UVC emitter is arranged in the housing and at least the part of the housing which is exposed to UVC radiation is made of aluminum or is coated with aluminum. In a second aspect, a method for disinfecting a gas or gas mixture with UVC radiation is provided in that the gas or gas mixture is passed through the housing in the longitudinal direction to at least one UVC emitter arranged in the housing.

State of the art

In public places, in hospitals and facilities where a large number of people come together, but also in private areas, the air can be so contaminated with germs such as bacteria and viruses that it should be continuously disinfected.

It is known that some bacteria and viruses can be killed with UVC radiation. There are studies on the relationship between radiation duration or intensity and effectiveness. It is believed that the effect of UVC radiation is based on the fact that nucleic acids of the microorganisms are damaged, so that they cannot replicate further and die or are completely destroyed.

For every technical disinfection it is necessary that the germicidal effect is reproducible, that is reliable, and that it extends with great certainty to all types of bacteria and viruses.

From the DE 10 2005 003 923 A1 a device and a method for disinfecting room air is known. This device is used in the breakdown of gaseous hydrocarbon emissions for the disinfection of room air conducted in an air duct. In the case of such a device, a UV unit for irradiating the ambient air with UV radiation is in a first section of the air guide duct, a catalyst for decomposing the ozone produced by the UV unit in a subsequent second section and one in a subsequent third section Ionization unit provided for ionization of the room air. In addition, a filter for microorganisms is provided in a device for the disinfection of room air conducted in an air duct between the first section and the second section. The UV unit described can have reflecting surfaces, in particular surfaces with a coating to achieve a photocatalytic effect, which are located between the UV tubes and on the side walls of the housing and increase the effect of the UV radiation.

In addition, in the US 2013/0323128 A1 described a photoreactor with two light sources. This can be used to free air, water or other fluids from toxic organisms. A light source activates the catalytic function of a semiconductor material and a second light source sterilizes the medium. LED light sources in a wavelength range of 265-285 nm and 370-385 nm are preferably used. Alternatively, mercury lamps with an emission at approximately 254 nm and / or 365 nm can be used individually or in combination with LED light sources.

Another air recirculation stand unit is from the US 5,616,172 A known. The air is drawn into the tower-like device from below and discharged upwards. The UV lamps are arranged perpendicular to the direction of flow. Upstream of this there is a pre-filter, which, among other things, prevents solid particles from getting into the device, for example through smoke, which can settle on the radiators and reduce their performance. Due to the laminar flow through the UV treatment room, different areas of the air flow are detected at different intensities. A similar device is also in the US 4,210,429 disclosed.

In the EP 2455 678 A2 describes a process for the disinfection of air, in which the air potentially contaminated with pathogenic germs is irradiated with UV light. For this purpose, the air flow within a treatment chamber of a device is passed transversely to the longitudinal axis of a rod-shaped UVC lamp through a gap formed adjacent to the surface of the lamp. Furthermore, a device is disclosed which, in addition to a UVC emitter, includes, among other things, means for conveying the air to be sterilized through the treatment room. Such a means can be a fan or a fan.

A decisive disadvantage of current devices for disinfecting gases or gas mixtures, in particular air, is that the surfaces of the device which are exposed to UV radiation are permanently exposed to this UV radiation. One consequence of this is, for example, partial corrosion of the surface, which reduces the reflective properties of the surface and significantly reduces the effect of UV radiation. This process occurs in particular on stainless steel surfaces, as a result of which the operating time of the device is significantly reduced and the effectiveness of the disinfection is impaired.

Description of the invention

The invention is therefore based on the object of sterilizing a gas or gas mixture which has potentially pathogenic germs, such as viruses and bacteria, in a simple and safe manner using a compact and low-maintenance device by means of UVC radiation.

In the present case, sterilization means that the microorganisms, including pathogenic germs, in the gas or gas mixture are damaged by the UVC radiation to such an extent that they cannot replicate further and die or are completely destroyed. The terms "sterilize" and "remove" are understood in the same way in the present case.

This object is achieved with a device according to the invention for sterilizing a gas or gas mixture with UVC radiation, the device having a housing, the housing being set up for irradiating the gas or gas mixture and having at least one inlet opening and at least one outlet opening. The device is characterized in that at least one UVC emitter is arranged in the housing and at least the part of the housing which is exposed to the UVC radiation consists of aluminum or is coated with aluminum.

The operating time of the device is advantageously significantly extended if at least the part of the housing which is exposed to UVC radiation is made of aluminum or is coated with aluminum. It has been shown that aluminum leads to a significantly longer service life than other materials, especially stainless steel. It is advantageous that the radiation intensity is even optimized with the use of aluminum due to the existing reflection properties.

In the present case, the expression “consists of aluminum” or “coated with aluminum” means that the surfaces exposed to UVC radiation have aluminum, in particular aluminum. A corresponding sub-area can be made of pure aluminum or an aluminum alloy with an aluminum content of over 50%. It is sufficient if the surface consists of aluminum or essentially aluminum so as not to attenuate the UVC radiation. It is also not excluded that a passivation layer made of aluminum oxide forms on the surface of the aluminum. Advantageously, the reflection properties in the housing are not impaired by the formation of an aluminum oxide layer, so that the operating life of the device is significantly extended.

In the present case, aluminum is understood to mean that this material is essentially pure aluminum, such as AL99, or aluminum alloys which contain at least 50% by mass of aluminum.

The device according to the invention, in which at least the part of the housing which is exposed to UVC radiation consists of aluminum or has (coated) aluminum only on the surface, is set up for simple and easy detection of pathogenic germs, in particular viruses and bacteria safe way to remove from a gas or gas mixture using UVC radiation.

UVC radiation is generally understood to be radiation less than or equal to approximately 300 nm and in the narrower sense less than or equal to approximately 280 nm. The mercury radiation line at 253 nm is known to have a strong germicidal effect, since the radiation into living matter at this wavelength leads to dimerization of certain DNA building blocks and the germs die off. Very short-wave UVC radiation should not be used because it forms ozone from the atmospheric oxygen, which ought to be removed from the air. This effort can be avoided by UVC radiation being carried out practically exclusively with light above a wavelength of 200 nm - more preferably with mercury light with a broad wavelength maximum of around 250 to 300 nm, in particular up to 280 nm - by using wavelengths below 200 nm filtered out or not emitted. Because ozone itself has a germicidal effect it is surprising that the invention achieves such a complete germicidal effect with relatively short-term, intensive radiation even without the presence of ozone.

In a preferred embodiment, the device is designed in such a way that the UVC emitter is arranged in the housing in such a way that the gas or gas mixture flow mostly runs longitudinally to at least one UVC emitter, in particular at least one rod-shaped UVC emitter. The UVC lamp can be tubular with a circular or polygonal cross-sectional area. In any case, however, this is arranged such that the gas or gas mixture flow mostly runs longitudinally to at least one UVC lamp. In this case, the gas or gas mixture stream can partly cross through at least one UVC emitter by swirling. This arrangement advantageously irradiates the gas or gas mixture with UVC radiation for as long as possible, so that the pathogenic germs, such as viruses and bacteria, in the gas or gas mixture are removed.

In a further embodiment, the device is designed such that at least one guide plate made of aluminum or a guide plate coated with aluminum is arranged in the housing, which guides the gas or gas mixture flow in the direction of at least one UVC emitter. The gas or gas mixture can first meet at least one UVC emitter transversely through the inlet opening and then can be guided along at least one guide plate made of aluminum or which has aluminum on the surface in the direction of a UVC emitter. Alternatively, the gas or gas mixture can first run in the longitudinal direction to at least one UVC radiator and shortly before it emerges from at least one outlet opening by means of at least one baffle made of aluminum or coated with aluminum, and can be directed across to a UVC radiator. This is particularly advantageous if the outlet opening is located transversely to the direction of extension of the UVC emitter. The gas or gas mixture is advantageously coated through the at least one aluminum or aluminum baffle so that it is exposed to UVC radiation for as long as possible, as a result of which the pathogenic germs, such as viruses and bacteria, are removed from the gas or gas mixture. In addition, the reflection properties in the housing are advantageously optimized by at least one baffle made of aluminum or coated with aluminum, so that the operating time of the device is significantly extended.

In any embodiment, the at least one baffle can be coated with aluminum only or have aluminum only on the surfaces that are permanently exposed to UVC radiation. Furthermore, the guide plate can be designed such that it can be connected to the housing. It can also have additional elements that are suitable for attaching UVC lamps. In addition, the baffle can have at least one opening that allows the gas or gas mixture to pass through it in order to expose it to UVC radiation. The device according to the invention can comprise a plurality of baffles which consist of aluminum or are coated with aluminum. The reflection properties in the housing are advantageously optimized by at least one guide plate coated with aluminum, so that the operating time of the device is considerably extended. It is also not excluded that a passivation layer made of aluminum oxide forms on the surface of the aluminum in a guide plate. Advantageously, the reflection properties of the baffle are not deteriorated by the formation of an aluminum oxide layer, so that the operating time of the device is significantly extended.

In one embodiment it is further provided that the device is designed in such a way that at least one UVC emitter emits at least a radiation power of 15 mW / cm ² watts. The radiation power of 30 mW / cm ² , such as 50 mW / cm ² watt, of at least one UVC emitter is advantageously sufficient to remove pathogenic germs, such as viruses and bacteria, in a gas or gas mixture.

In a further embodiment, the device is designed such that the at least one UVC emitter emits radiation with a wavelength above 200 nanometers. The radiation advantageously has a wavelength above 200 nanometers, in particular 200 nanometers to 300 nanometers, in order to remove pathogenic germs, such as viruses and bacteria, from a gas or gas mixture. When using radiation above 200 nanometers, there is the advantage that the formation of ozone is immediately avoided, which makes the process uncomplicated and reliable. The ozone therefore no longer has to be removed. Costs that would be necessary for the subsequent removal of the ozone, for example for a catalyst, can thereby be eliminated. Nevertheless, the overall treatment effect is not reduced if the additional germicidal ozone is dispensed with.

In a further embodiment it is provided that the device is designed such that at least one UVC lamp is a mercury or excimer lamp. The at least one UVC lamp can be a mercury lamp (for example mercury vapor lamp, amalgam lamp) or an excimer lamp exhibit. Low-pressure mercury or medium-pressure mercury lamps, as are commercially available, are particularly suitable. The values in Table 1 were determined using a series of low-pressure, low-pressure mercury lamps.

The desired radiation density can be achieved with various commercially available emitters. Table 1 provides an overview: Table 1 UV lamp output * (low-pressure mercury-free lamp) mW / cm ² Distance to the sensor (cm) Lamp power 6W 18 W. 36 W. 58 W. 5 39.10 57.00 53.00 76.90 7 27.30 40.10 38.20 55.60 9 20.70 32.30 31.00 45.40 11 15.80 27.60 27.30 38.00 13 12.70 24.30 25.00 34.60 * Measuring device DR. Gröbel RM11, measured wavelength 254 nm

In a preferred embodiment, UVC radiation sources with wavelength exclusion below 200 nanometers are used (so-called non-ozone-forming UVC emitters).

The wavelength exclusion below 200 nanometers is preferably effected with the aid of a wall which is partially transparent to the radiation. The wall may be an outer wall of the radiator, preferably surrounding the radiator in each radiation direction, or an additional wall or shield arranged around the radiator.

The UVC radiation source is preferably surrounded by a protective glass body which is not transparent to light with wavelengths below 200 nanometers. As described above, this can be the outer wall of the radiator or an additional protective tube. In a preferred embodiment, the partially transparent wall consists of a silicate glass which is impermeable for wavelengths below 200 nanometers. Such glasses, often synthetic quartz glasses, are known to the person skilled in the art.

If a tubular UVC lamp is used, an additional outer tube from the shield, for example a glass body made of the silicate glass mentioned, can be pulled over the lamp. Such a tube serves at the same time to filter out short wavelengths and to protect the radiator from dirt, since the protective and shielding tube can be easily replaced and cleaned. However, the additional outer tube also leads to a loss of light intensity (loss of performance). It is therefore considered to be more advantageous if the outer wall of the radiator itself, that is to say the glass body of the radiator itself, consists of a transparent material which effects the wavelength exclusion below 200 nanometers.

A rod-shaped emitter can also be represented using several short emitter elements or composed of point light sources of a suitable wavelength.

Furthermore, the invention relates to a method for sterilizing a gas or gas mixture with UVC radiation, the gas or gas mixture in the device according to the invention being passed through the housing at least partially in the longitudinal direction to at least one UVC radiator arranged in the housing. The gas or gas mixture is advantageously guided in the longitudinal direction to at least one UVC emitter arranged in the housing, since the gas or gas mixture is thus exposed to UVC radiation for as long as possible, as a result of which the pathogenic germs, namely viruses and bacteria, in the gas or gas mixture be removed.

In one embodiment, in the method, each partial volume of the gas or gas mixture stream is exposed to a radiation power of at least 15 mW / cm ² , such as at least 30 milliwatts per square centimeter. The radiation power of at least 15 mW / cm ² , such as at least 30 milliwatts per square centimeter, is advantageously sufficient to remove pathogenic germs, such as viruses and bacteria, from the gas or gas mixture.

In one embodiment it is further provided that in the method the UVC irradiation with radiation with a wavelength above 200 nanometers takes place. It is advantageous that when using radiation with wavelengths above 200 nanometers, ozone formation is immediately avoided, which makes the process uncomplicated and safe to use, since the ozone no longer has to be removed subsequently. Costs that would be necessary for the subsequent removal of the ozone, for example for a catalyst, can thereby be eliminated. Nevertheless, the overall treatment effect is not reduced if the additional germicidal ozone is dispensed with.

The volume flow of air that is led past the UVC lamp should be selected so that the pathogenic germs, such as viruses and bacteria, are removed from the gas or gas mixture, since the gas or gas mixture of the UVC radiation over a certain time must be suspended.

In a particularly preferred embodiment, the direction of the gas or gas mixture stream is changed in the method according to the invention by at least one guide plate made of aluminum or a guide plate coated with aluminum in the housing, in particular in the longitudinal direction to at least one UVC lamp. It is advantageous here that the gas or gas mixture, after entering the housing through the inlet opening, initially runs transversely to at least one UVC emitter and is then directed in the longitudinal direction to at least one UVC emitter by at least one aluminum baffle or an aluminum-coated baffle can. As an alternative or in addition, the gas or gas mixture stream can be directed transversely to at least one UVC emitter immediately before the outlet by a guide plate made of aluminum or a guide plate coated with aluminum changing the direction of the gas or gas mixture stream. The gas or gas mixture is advantageously passed through the housing in such a way that it is irradiated with UVC radiation for a sufficient time to remove the pathogenic germs, such as viruses and bacteria, from the gas or gas mixture.

• 1: Ausführungsbeispiel einer Vorrichtung zur Entkeimung eines Gases oder Gasgemisches mit UVC-Strahlung, umfassend ein Gehäuse mit einer Eintrittsöffnung, einer Austrittsöffnung und zwei stabförmigen UVC-Strahlern.

In the following, the invention is based on a 1 shown embodiment explained in more detail. The drawing shows:

• 1 Embodiment of a device for disinfecting a gas or gas mixture with UVC radiation, comprising a housing with an inlet opening, an outlet opening and two rod-shaped UVC emitters.

1 shows an embodiment of a device according to the invention for sterilizing a gas or gas mixture with UVC radiation. The device comprises a housing 1 with an entry opening 2nd and an outlet opening 3rd . The gas or gas mixture is in a gas or gas mixture stream 4th through the entrance opening 2nd led into the housing by placing it transversely on a first UVC lamp 5 and then on a second UVC lamp 6 meets. Through a baffle 7 aluminum becomes the gas or gas mixture stream 4th in the longitudinal direction of the first UVC lamp 5 and the second UVC lamp 6 directed. While the gas or gas mixture is irradiated with UVC radiation, the pathogenic germs, such as viruses and bacteria, are removed from the gas or gas mixture. The sterilized gas or gas mixture then emerges from the outlet opening 3rd out of the case 1 out.

In the 1 are the surfaces of the case 1 and the baffle 7 made of aluminum, which are exposed to UVC radiation. This advantageously ensures that the radiation intensity is optimized on the basis of the existing reflection properties. It is not excluded that a passivation layer made of aluminum oxide has formed on the surface of the aluminum. In any case, the advantages according to the invention mentioned could be achieved.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included 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.

Patent literature cited

• DE 102005003923 A1 [0005]
• US 2013/0323128 A1 [0006]
• US 5616172 A [0007]
• US 4210429 [0007]
• EP 2455678 A2 [0008]

Claims (10)

Device for sterilizing a gas or gas mixture with UVC radiation, the device having a housing (1), the housing (1) being set up for irradiating the gas or gas mixture and at least one inlet opening (2) and at least one outlet opening (3) characterized in that at least one UVC emitter (5, 6) is arranged in the housing and at least that part of the housing (1) which is exposed to UVC radiation is made of aluminum or is coated with aluminum. Device after Claim 1 , characterized in that the UVC lamp (5, 6) is arranged in the housing (1) in such a way that the gas or gas mixture stream (4) largely along at least one UVC lamp (5, 6), in particular a rod-shaped UVC lamp (5, 6). Device according to one of the preceding claims, characterized in that at least one baffle (7) made of aluminum or an aluminum-coated baffle (7) is arranged in the housing (1), which the gas or gas mixture flow (4) in the longitudinal direction conducts at least one UVC lamp (5, 6). Device according to one of the preceding claims, characterized in that at least one UVC emitter (5, 6) applies at least a radiation power of 15 mW / cm ² . Device according to one of the preceding claims, characterized in that the at least one UVC emitter (5, 6) emits radiation with a wavelength above 200 nm. Device according to one of the preceding claims, characterized in that at least one UVC lamp (5, 6) is a mercury or excimer lamp. Method for disinfecting a gas or gas mixture with UVC radiation, characterized in that the gas or gas mixture is passed through a device according to one of the preceding claims, the gas or gas mixture being arranged at least partially in the longitudinal direction through the housing to at least one in the housing UVC lamp (5, 6) is passed. Procedure according to Claim 7 , characterized in that each partial volume of the gas or gas mixture stream (4) is exposed to a radiation power of at least 15 mW / cm ² , such as at least 30 mW / cm2. Procedure according to one of the Claims 7 or 8th , characterized in that the UVC radiation is carried out with radiation having a wavelength above 200 nm. Procedure according to one of the Claims 7 to 9 , characterized in that the direction of the gas or gas mixture flow (4) through at least one guide plate (7) made of aluminum or an aluminum-coated guide plate (7) in the housing (1), in particular in the longitudinal direction to at least one UVC lamp ( 5, 6) is changed.

Images