WO2022033722A1

WO2022033722A1 - Apparatus for sterilizing aerosol-containing air

Info

Publication number: WO2022033722A1
Application number: PCT/EP2021/025308
Authority: WO
Inventors: Horst Hahn; Thomas Blank; Jochen KRIEGSEIS
Original assignee: Karlsruher Institut für Technologie
Priority date: 2020-08-11
Filing date: 2021-08-09
Publication date: 2022-02-17
Also published as: DE202021103664U1; DE102020121130A1

Abstract

Apparatus (1) for sterilizing aerosol-containing air, comprising at least one through-flow channel (13) with one or more through-flow cross sections, comprising at least one fan (7) for generating an air stream in the through-flow channel, comprising means for sterilizing (10) at least one aerosol in the air stream, comprising at least one intake opening (4) for taking the aerosol-containing air into the through-flow channel, and comprising at least one outgoing-air opening (6) for discharging a sterilized air stream from the through-flow channel, wherein the at least one intake opening opens out into at least one intake volume (14), and wherein each of the at least one intake volumes is respectively adjacent to an aerosol source.

Description

Device for sterilizing air containing aerosols

The invention relates to a device for the sterilization of aerosol-containing air, preferably with an aerosol contaminated with a pathogen such as corona virus SARS-CoV-2, cold and flu viruses and other contagious viral pathogens according to the first claim.

Indoors, where people are in high densities in a certain spatial order, there is an increased risk of infection due to the transmission possibilities of viruses, in particular Corona Virus SARS-CoV-2, through aerosol particles contaminated with viruses that are exhaled by the people present there or expelled when you sneeze or cough. Due to their small size (mass), aerosols are airborne and can remain airborne indoors for up to several hours, depending on the ambient conditions. Such interiors include u . a. Restaurants, seminar and training rooms, classrooms in schools, lecture halls, doctor's offices, doctor's meeting rooms, gyms, etc. , but also clean rooms or other rooms with a controlled atmosphere .

Due to the transmission paths via aerosols, minimum distances are therefore necessary, e.g. B. Against the background of the current requirements for the corona virus SARS-CoV-2, larger table distances in restaurants, which in turn lead to high economic losses due to the lower occupancy rate. Similarly, these requirements for distance rules in schools mean that lessons can only take place in smaller groups for shorter lesson times, which leads to massive cancellations of lessons. In these environments however, there are usually individuals or small groups of people at a fixed place in the interior (e.g. four family members at a table in the restaurant, or a group of three students at a work table, or a single person at a fitness device in the studio , or a patient at the dentist ) . The aim is therefore to facilitate the exchange of aerosols from one person or from one group of people to another group of people, e.g. B. from one table in the restaurant to the next or the table after that, to prevent or reduce.

In addition, the transmission of viruses by aerosols is influenced by external environmental influences such as temperature and humidity, which have an impact on the lifespan of the aerosols and thus the viruses in the air. The aerosol particles can dry out more quickly in dry air and thus render the virus harmless more quickly than is possible in humid air. This can be observed particularly drastically, e.g. B. in slaughterhouses, where low temperatures and high humidity favor the transmission of the virus.

For example, suction devices are known, in particular for commercial applications, in which a suction opening such as a suction bell is positioned at an emission source and the emissions are sucked up and passed on to a waste air duct system. For reasons of noise protection alone, extraction usually takes place at the end of the exhaust air duct system. Sterilization - if planned at all - usually takes place centrally for all connected suction devices, away from the exhaust air duct system. However, such suction devices are exhaust air systems, i. H . In closed rooms, the extracted air will flow back into the room through other openings, which in turn does not allow use in security areas or clean rooms in particular. Furthermore, exhaust air systems for rooms are known in which the air is usually extracted at only a few points in the room, often on the ceiling. The extraction takes place integrally and not separately for each emission source, which is particularly unsatisfactory for the extraction and destruction of air containing pathogens.

Furthermore, recirculation systems are known in which the air in a room is sucked in, treated, ie. H . cleaned , filtered and / or brought back into the room at a different point . They are primarily used for air conditioning in closed rooms, vehicles and buildings.

As circulating air cleaning systems, circulating air systems are preferably air conditioning and cleaning systems in clean rooms, in which the extracted air is conducted centrally or decentrally at sources of contamination, usually via a circulating air duct system, out of the room, where it is cleaned, filtered and/or brought back into the room at a controlled temperature. Similar circulating air systems are also used, for example, for vehicle air conditioning or for air conditioning of mainframe systems.

An example of circulating air cleaning systems, in which the air drawn in for treatment is not routed out of the room, are circulating air extractor hoods for kitchen and laboratory applications.

However, approaches are also known in which circulating air cleaning systems are also used additionally or exclusively for the disinfection of air flowing through.

From EP 2 455 678 A2, such a circulating air cleaning system for the disinfection of flowing air, in particular for the cli- nical area known . For this purpose, the air flow, preferably in a volume flow of up to 250 m ³ /h, is exposed by means of a UVC emitter with a radiation output of at least 30 mW/cm ² and is thus sterilized. Light with a wavelength above 200 nm is preferably used here. Furthermore, it is proposed to combine the cleaning with an additional ionization and/or for particle separation with a filter cleaning. Local exhaust ventilation directed at a contamination source is not disclosed. A combination of a HEPA filter and a downstream UV sterilization for use in a ventilation and air conditioning system in general is also known from DD 1576 26.

DE 10 2015 013 630 A1 also discloses a device for producing germ-reduced room air, in particular for technical storage systems. Germs are also killed by UVC radiation. This system also does not have local exhaust ventilation directed at a source of contamination.

DE 20 2016 004 286 U1 discloses a ventilation arrangement with an extractor hood intended for extracting vapor for the kitchen area, in which UV light emitters are arranged downstream of a separator and cause ozone formation there in such a way that, in addition to the antibacterial effect, particles contained in the filtered exhaust air are also removed be crushed and reach the vent via a suction device. The system is designed in such a way that mixed air can be formed from external fresh air and/or kitchen vapors.

However, all the circulating air cleaning systems mentioned are often characterized by a pronounced noise development, since the sucked-in air is passed through a pressure-reducing cleaning stage, usually a filter element, must be promoted. However , this severely limits the usability .

Based on this, one object of the invention is to design a device of the type mentioned at the outset in such a way that it is suitable for the sterilization of air containing aerosols, preferably with a pathogen such as corona virus SARS-CoV-2, cold and flu viruses and other infectious viral ones Pathogens, on the one hand and conceptually suitable for use in noise-sensitive environments.

The object is achieved with a device having the features of claim 1 . Subclaims referring back to this reflect advantageous embodiments and refinements.

A solution to the task is based on the basic idea of a combination of local capture of the aerosols in one place with one person, with several people belonging together (e.g. at a restaurant table) or another aerosol source, combined with local deactivation of the virus (rendering harmless) with simultaneously low flow resistance.

Consequently, a device is proposed that sucks in aerosol-containing air from at least one suction volume in an immediate and locally definable surrounding area via at least one suction opening, sterilizes it in the device and releases it back into this surrounding area via at least one exhaust air opening. The surrounding areas preferably extend in the range between 1 and 4 m, more preferably in the form of columns or spheres around the device. The distance between the suction opening and the exhaust air opening is preferably a maximum of 1.5 m, more preferably a maximum of 1.0 m. A cleaning of the air from the aerosol and/or particles is not in the foreground, but rather the most effective possible sterilization of the aerosol-containing air sucked in. Separation stages, which would cause additional flow resistance in the device, are not required. Nevertheless, within the scope of individual embodiments, separating means or means for separating flow components within the scope of the means for sterilization are also proposed below, which, however, only assume their function in the overall context of sterilization. The aim of the treatment running at the same time as the separation is to render the viruses harmless so that there is no longer any infectivity.

To achieve the object, a device for the sterilization of air containing aerosols is therefore proposed, comprising the following components: a) at least one flow channel with one or more flow cross sections, preferably one flow channel with a flow cross section, b) at least one fan for generating an air flow in the flow channel, c) means for sterilizing at least one aerosol in the air flow, d) at least one suction opening for the aerosol-containing air into the flow channel and e) at least one exhaust opening for a sterilized air flow from the flow channel, wherein f) the at least one suction opening in at least one intake volume opens out, each of the at least one intake volume adjoining an aerosol source. In this context, local means a close proximity to the equipment, preferably combining the intake and discharge of the aerosol-containing air with the sterilization of this air, preferably in circulating air mode. Local also means in particular the close proximity of the device to the intake volume and to the at least one aerosol source adjacent to it as a local demarcation to neighboring devices/intake volumes/aerosol sources with other, preferably non-overlapping intake volumes in the same room. In a restaurant z. B. the individual tables with people sitting at them (aerosol sources) as well as a device arranged on, above or below the table with an intake volume arranged in between (preferably above the table top) a local system that is locally delimited from neighboring systems of the same type.

It is essential that the air is sucked in from the volume with the local aerosol source. The intake volume mentioned is consequently the volume directly in front of the intake opening (distance preferably up to 1 meter between intake opening and aerosol source) and is located in the inflow area of the device. An intake volume also includes at least one of the aerosol sources that release an aerosol into the intake volume. In the inflow area, a dominating flow directed in the direction of the intake opening forms.

The intake volume mentioned is consequently defined as the limited volume directly in front of the intake opening with a free distance from the intake opening of 0.6 m, preferably 1.0 m, more preferably 1.5 m. It preferably includes the volume area between the suction opening and the aerosol source. It is in fluid contact with an aerosol source, e.g. B. an exhaling human, and the intake opening as an aerosol sink . More preferably, an intake volume comprises at least the smallest sphere volume between an intake opening and an aerosol source, with both the intake opening and the aerosol source touching the spherical surface of the sphere volume.

The at least one flow channel connects, preferably outgoing or incoming branch, the at least one intake opening with the at least one exhaust air opening. The at least one flow channel has a flow cross section at each point (in total) which does not necessarily have to be uniformly constant. The flow channel is completely or for the most part, i. H . preferably aligned vertically in at least one section. In favor of a low flow resistance, a preferably rectilinear configuration is proposed, but also has flow deflection areas depending on the embodiment described below and the configuration of the means for sterilization. Flow deflection areas at the bottom can also be configured as collection areas, preferably collection containers, for separated aerosol components and/or particles.

A fanning out or subdivision into several flow channels (partial channels) and/or a combination of several flow channels (partial channels) between the at least one intake opening and the at least one exhaust air opening fall within the scope of the invention. In principle and apart from aerosol components temporarily separated in the through-flow channel and/or the aerosols and/or particles rendered harmless by the device, the sucked-in quantity of air then preferably leaves the device again only via the at least one exhaust air opening. In principle, the invention comprises the following basic forms of execution of the means for sterilization:

- Means for sterilization, which act on the air flow to be sterilized directly and on deposited aerosol components, one or more stages. The means also include means for separating the at least one aerosol or parts thereof from the air flow. These means for separation are preferably used for the selective and temporary fixation of aerosol components for subsequent sterilization. They are not intended for the separation of dust particles or other solid components.

- Means for sterilization, which act directly on the air flow to be sterilized, in one or more stages, but without the aforementioned means for separating the at least one aerosol or parts thereof from the air flow.

Depending on the embodiment, the means for sterilization have an effective area in the flow channel and/or over the separation surfaces. They can also be designed as follows and therefore include at least one of the following means:

- heating medium with effective range in the flow channel,

- UV light source, preferably a UVC light source, with an effective area in the flow channel,

- Means for a plasma discharge with an effective area in the flow channel, and/or

- At least one microwave source with effective range in the flow channel.

The invention is explained in more detail by means of implementation forms and examples, the following figures and descriptions. All of the features shown and their combinations are not limited to these exemplary embodiments and their configurations. Rather, these should be viewed as representative of further possible configurations that are not explicitly shown as exemplary embodiments and can be combined. Show it

Fig. la and b schematically show an exemplary arrangement of an embodiment of the device in a side view (a) and top view (b),

Fig. 2a to c schematic cross-sectional views of preferred configurations for an arrangement according to FIG. la and b,

Fig. 3 shows a schematic cross-sectional view of a preferred embodiment for an arrangement on a tabletop,

Fig. 4a and b schematic example underfloor arrangements of embodiments of the device in a side view,

Fig. 5 schematically shows an exemplary further embodiment in which the at least one exhaust air opening opens directly into the at least one intake volume,

Fig. 6a and b schematically further embodiment according to FIG. la and b, however, comprising at least one means for deflecting the air flow from the exhaust air opening in the direction of the at least one suction opening,

Fig. 7a and b schematic exemplary means for sterilization, comprising an electrostatic separation for the aerosol, Fig. 8a and b schematically exemplary means for sterilization, comprising a separation for the aerosol by means of an inertial force separator and/or a filter surface spanning the flow cross section,

Fig. 9a to d in schematic sectional top views over the flow cross section of the flow channel, exemplary means for sterilization, comprising elements around which flow can take place, and

Fig. 10a and b a particularly preferred embodiment with an embodiment of the means for sterilization by means of UVC LEDs and waste heat conducting plates.

As part of a through Fig. In the preferred first embodiment represented, the device 1 is arranged above a table or worktop 2 or a walk-in room. People 3 (or other sources of germs) as aerosol sources usually sit around the table or are in the room, with the at least one suction opening 4 preferably being arranged at the level of or above the aerosol sources (e.g. breathing openings of the people) and preferably downwards point .

Fig. 2a to c show simple preferred configurations for this in schematic cross-sectional views. They each comprise a vertically aligned tubular housing 5 open on both sides, the lower opening forming the intake opening 4 and the upper opening forming the exhaust air opening 6 . The fan 7 is preferably switched on or off in or on the exhaust air opening. put on . It preferably spans the entire flow cross section. The means for sterilization 10 are located in the housing between the fan and the suction opening. The suction opening preferably points downwards. The tubular housing preferably has a constant cross-section (Fig. 2a). With a flow cross section of the housing that widens downwards in a trumpet shape towards the outlet (FIG. 2b), the aerosol-containing air is sucked in in a more streamlined manner from the suction volume 14 via the table. It advantageously promotes a laminar flow into the device. A suction that can be customized for each person separately is shown in FIG. 2c, in which the suction openings 4 flow radially into the housing 5 at the bottom side. The orientation of these suction openings can preferably be adjusted.

Also located in the housings in the through-flow channel 13 are the means for sterilizing 10 the aerosol-containing air flowing through, which are in turn arranged with arrows. The means for sterilization are single or multi-stage.

A preferred embodiment of this includes a shown in FIG. 3 is an example of a vessel 11 open at the top, into which part of the device 1 including the suction opening 4 is inserted, forming an annular gap volume 12 . The device with the vessel is preferably a table-top device, the vessel lying at least partially in the at least one suction volume and serving as a means for deflecting the aerosol-containing air that is sucked in.

As part of a preferred further embodiment according to FIG. 4a, the device 1 is arranged underneath a floor, table or worktop 2, with the suction opening pointing upwards through the floor, table or worktop. The advantage is that this configuration represents an underfloor design and is therefore better shielded by the floor, table or worktop with its structural volume and its operating noise. Advantageously, it is no longer felt to be so annoying. A particularly advantageous embodiment in this regard provides for the suction opening 4, which is open at the top, to be covered with a cover element at a distance from the floor, table or worktop 2, forming a circumferential suction gap 21. In the case of a table, this cover element is preferably a cover plate 8 which can be used as a storage space, e.g. B. can be used for food (Fig. 4b). In this case, the gap opens out in a particularly advantageous manner at the point in the extraction volume at which people sitting around the table preferably exhale.

Fig. 4b also shows optional passage openings 22 through the floor, table or worktop 2 arranged below the intake volume 14. FIG. They are used to return the air flow from the exhaust air opening 6 into the suction volume 14 , with an optional deflection trough 23 as an additional means for deflection 19 improving the return of an increased proportion of the sterilized air flow. As shown, the edge of this deflection trough 23 is arranged at a distance from the underside of the tabletop to avoid back pressures (e.g. through covered passage openings), which allows the sterilized air flow to escape around the edge of the tabletop (preferably between the tabletop and the people sitting at the table) back to the suction volume 14 allows .

In principle, the exhaust air opening can also be connected to an exhaust air duct system, with the fan being part of the exhaust air duct system.

In general, the at least one fan 7 is preferably arranged in the flow channel 13 between the means for sterilization 10 and the exhaust air opening 6 and/or at the exhaust air opening 6 . At this point in the device, the noise of the fan can best be shielded. Advantageously, only the sterilized air stream flows against the ventilator. However, this also pursues a general objective of the invention, namely that the sucked-in non-sterilized air flow is fed directly to the means for sterilization without coming into contact with other elements, such as e.g. B. Filter elements or flow control elements of the fan. This also reduces the required disinfection intervals of the device.

In principle, the fan can also be designed as a sheath flow fan, which is preferably used centrally in the flow channel and does not take up the entire flow cross section. It is consequently not only penetrated by the air flow, but also flows around it and generates a central air flow, which then takes the surrounding air flow areas through the flow channel, preferably out of the exhaust air opening. The flow profile is therefore maximum in the flow cross-section in the area of the ducted flow fan and then decreases towards the walls of the flow channel and thus the exhaust air opening, which means not only quieter operation, but also fundamentally lower turbulence when the sterilized aerosol-containing air exits. This serves in particular for the comfort of the people in the vicinity of the device.

A preferred further embodiment is represented by FIG. 5 . It provides that the at least one exhaust air opening 6 opens directly into the at least one intake volume 14 . In this way, the sterilized air flow leaving the exhaust air opening is fed back from the flow channel directly into the at least one intake volume and thus advantageously dilutes the concentration of germs in the aerosol-containing air in the intake volume. The exemplary embodiment shown in FIG. 5 includes, for example, a device that can be placed on a tabletop 2, ie between, and preferably in the center of, the people sitting at the table. Here, for example, a suction opening 4 or row of suction openings oriented radially outwards towards the people and an exhaust air opening 6 or row of exhaust openings also oriented outwards are provided, the air then being directed radially inwards into at least one vertical through-flow channel section 15, in which the means for Sterilization 10 and preferably also the fan 7 are arranged. The suction opening 4 is preferably located below the persons' breathing openings (mouth and nose) and aligned with them. The suction opening and exhaust air opening are preferably not only close to one another, but also directed parallel to one another towards the suction volume. In the example, these are horizontally separated from one another by a partition plate 16, with a lower vessel-shaped housing half 17 delimiting the intake opening 4 at the bottom and an upper vessel-shaped housing half 18 delimiting the exhaust air opening 6 at the top.

Basically, the embodiment shown in Figure 5 also corresponds to a previously mentioned embodiment, as shown for example Figure 2a and b, supplemented by the upper and lower housing halves 17 and 18 and the partition plate 16 as a means for deflecting the air flow in and out Contraption .

A preferred further embodiment is represented by FIGS. 6a and b. They comprise at least one means for deflecting 19 the sterilized air flow from an exhaust air opening 6 as return air flow in the direction of the at least one suction opening 4 or of the at least one suction volume 14 at the at least one suction opening. This means that the exhaust vent The sterilized air flow leaving is not introduced directly into the intake volume, but is only deflected in the direction there by the deflection means 19 .

The means for deflection comprise at least one deflection plate 20 or at least one deflection duct (eg deflection hoses, preferably adjustable in direction) preferably immediately downstream of the exhaust air opening 6 in the direction of flow. This means that the sterilized air flow leaves the cleaning system with the exhaust air opening and thus has the possibility of mixing with the prevailing ambient air before it reaches the intake volume 14 despite the deflection means.

A special embodiment provides that the means for deflection 19 open out or are directed directly into the at least one intake volume 14, more preferably into the intake volume from which the deflected sterilized air flow originally comes. Here, the air flow is directed away from the aerosol source directly to the at least one intake volume. In the case of a table with a device arranged centrally above it (cf. also Fig. la and b), this means that the deflected sterilized air flow is directed downwards in the direction of the table surface, specifically in front of the heads of the people sitting at the table (cf. Fig 6a) .

An alternative embodiment provides that the aerosol sources are positioned between the deflection means 19 and the at least one suction opening 4 . In the case of a table with a device arranged centrally above it, this means that the deflected sterilized air flow is directed downwards but behind the heads of the people sitting at the table 3 is directed (cf. Fig. 6b). Due to the suction from the suction volume in front of the heads of the people sitting at the table, the sterilized air flow also moves up past the heads into the suction volume 14 .

Configurations of the means for sterilizing the at least one aerosol or portions thereof in the air flow are explained in more detail below.

First configurations of the means for sterilization also include means for separating the at least one aerosol or portions thereof in the air flow. These means for separation are preferably used for the selective and temporary fixation of aerosol components for subsequent sterilization. They are not intended for the separation of dust particles or other solid components.

An embodiment of these means for sterilization, represented by FIG. 7a and b, comprises at least one separation surface 24 for the aerosol as a means for separation. The aerosol can preferably be fixed on the separation surfaces for sterilization. The provision of an electrostatic field 25 between two electrodes 26 is preferably additionally proposed. The electrostatic field extends at least over part of the at least one separation area. More preferably, this field extends at least at one point in the flow channel 13 over the entire flow cross section. An aerosol guided past the separating surfaces (throughflow marked with arrows) thus automatically passes through the electrostatic field, with aerosol components 27 , in particular already ionized components, preferably being deflected towards the separating surfaces 24 . Optionally, a (not shown presented) upstream ionization stage for the aerosol components before entry into the electrostatic field. It is also proposed that one of the electrodes as shown in FIG. 7a and b is formed by at least part of the at least one separating surface, arranged between the at least one suction opening and the electrostatic field in such a way that it captures the air flow in the entire flow cross section.

Fig. 7a shows an exemplary configuration without built-in components, i. H . Flow obstacles in the flow channel. The electrodes face each other flat; the deposition surface 24 can be irradiated, for example, by the other electrode, for example by a UV radiation source arranged on the inner wall of the housing 5 .

In contrast, FIG. 7b shows an embodiment in which the separation surface 24 is formed by the peripheral inner wall of the housing 5 and spans a peripheral electrostatic field 25 with a central electrode 26.

The constellations shown are particularly suitable for sterilization by means of an electrostatic plasma field over the separating surfaces or the separating areas, alternatively also for thermal sterilization by heating the separating surfaces z. B. using a microwave.

In addition or as an alternative to this, it is proposed that at least part of the at least one aforementioned separation surface has coolant (preferably fluidly via coolant circuits or electrically via Peltier elements) for a surface temperature. This cools down the surface temperature of the separation surfaces, preferred wise below 10 °C, more preferably below 0 °C. Depending on the set temperature, cooling accelerates the formation of condensation or frost and thus the binding of aerosol components when they hit a separation surface, and a redetachment of these by evaporation or sublimation is advantageously delayed.

Provision is preferably made for the aerosol components fixed on the at least one separating surface 24 to also be sterilized there, with these evaporating or sublimating after, but preferably during, the sterilization and thus leaving the separating surface sterilized.

A further configuration of the means for separation is represented in FIG. 8a and b. They comprise at least one inertial force separator and/or a filter surface spanning the flow cross section.

Fig. 8a shows, by way of example, means for separation in the form of an inertial force separator 29, preferably with at least one flow deflection 28 and subsequent separation areas 30 after each flow deflection, ie. H . at least one separate separation surface for the at least one aerosol. Inertial mass separators preferably use the inertial mass differences of air and aerosol components in the case of a flow deflection and/or flow velocity change for material separation. As a result, there is local accumulation of the aerosol components in the air, for example in the aforementioned separation areas. The separating surfaces of the separating areas can preferably be heated during sterilization, d. H . the sterilization (and immediately following vaporization) preferably takes place with the impact of aerosol components on the separation surfaces. In one in Fig. 8b as an example, a filter surface 31 spanning the flow cross section of the flow channel 13 is proposed as an alternative or in addition, which can be used as separation surfaces or separation areas for a temporary fixation of aerosol components for the subsequent sterilization. The preferably sloping arrangement of the filter surface shown advantageously causes an increase in the filter surface available as a separation surface and enables a preferred arrangement of at least one UV radiation source 32 for sterilizing the aerosol components separated on the filter surface on the inner wall of the tubular housing 5 .

To shield the environment from UV radiation escaping from the flow channel 13, additional light-tight, open-pored foam elements 33, preferably designed as metal foam elements, are arranged on both sides of the UV radiation sources 32.

In a further preferred embodiment, the aforementioned open-pore foam elements through which flow can take place can be heated, preferably designed as metal foam elements by means of resistance heating or with a microwave source. They therefore serve as an alternative or additional sterilization stage, whereby the pore surfaces can also be used as temporary separation stages for aerosol components.

The separation areas or additional separation areas are preferably positioned in the areas of local accumulation of the aerosol components. The mass force separators and/or the filter surfaces serve as separation surfaces, in contrast to the prior art not for permanent fixation and removal , but the temporary fixation of aerosol components for subsequent sterilization .

Furthermore, it is preferably proposed here that the at least one mass force separator and/or the filter surface form or have at least one separate separation surface for the at least one aerosol.

The aforementioned separation means, in particular the preferred separation surfaces or separation areas, are part of the sterilization means. This follows the idea of first separating and/or fixing the aerosol in order to then sterilize it using the following means. The means for sterilization that can be combined with these are preferably: a) an electrostatic plasma field over the separation surfaces or the separation areas (cf. in particular FIG. 7a and b), and/or b) a heating means for heating the medium flowing through, d. H . the air and the aerosol, preferably in the separation area, preferably also heating the at least one separation surface to a temperature of over 40° C., preferably over 70° C., and/or c) at least one UV radiation source (preferably UVC radiation source), preferably UV or comprising UVC LEDs or a gas discharge lamp (preferably a mercury gas discharge lamp) with a wavelength between 180 and 410 nm, preferably between 220 and 280 nm, preferably aimed at the separation surfaces or separation areas (cf . in particular . Fig. 8a and b) , and or d) a microwave source for heating the at least one separating surface or the separating area.

In the operating state, the means mentioned are preferably activated with a constant load or setting, alternatively in pulses, cyclically or at intervals.

The means for sterilization mentioned under b) and d) are distinguished from the means mentioned a) and c) by an increased temperature emission, which is why they are proposed in particular for environments that are not sensitive to heat. As an alternative to this, it is proposed to combine these agents with other agents, preferably the UV sterilization mentioned under c). Here, the means mentioned under b) and d) serve to lower the temperature z. B. adjusted between 30 and 50 °C, only the pre-damage through the onset of drying of the aerosols contaminated with germs and thus to increase the efficiency of a subsequent UV sterilization.

Furthermore, means for sterilization without the above-mentioned means for separating the at least one aerosol or parts thereof in the air flow are also proposed. The effective range of these means preferably spans the flow cross section at least at one point or, in the case of a fanning out, the flow cross sections completely. These means for sterilization, which are proposed alone or in combination with one another, are the following: a) At least one heating means with an effective area in the flow channel:

The aim here is the most complete possible convective heating of the entire air flow over the entire flow cross section in direct contact with the heating elements or additional heat transfer elements. Compared to well-known hot air blowers (heaters, hair dryers, etc.), this heating medium is characterized by a maximum temperature of the heating elements or additional heat transfer elements below 100 °C, preferably below 70 or 50 °C. In order to ensure complete heating, at least one fanning of the air flow into sub-channels is advantageous in the through-flow channel to realize shorter heat transfer paths in the air flow. This requires at least elements 34 that can be flown onto or around in the through-flow channel, some of which are shown as examples in the plan views of the through-flow cross-section in FIG. 9a to d are shown schematically. Fig. 9a represents a foam element 33, preferably a metal foam element (cf. FIG. 8b), while exemplary FIG. 9b to d show profile inserts which preferably do not change in the axial direction of the tubular housing 5 or only change with a helical twist. The at least one heating means preferably comprises at least one resistance heating element with or without heat transfer elements, which is arranged as at least one element 34 of the aforementioned type that can be flowed against or around it in the through-flow channel, more preferably so that the air flow can flow against or around it. Heat is preferably transferred via heat dissipation ribs or an open-pored metal foam (foam element 33, Fig. 9a) or a sieve or sieve fabric in the flow channel (example the profile inserts shown in Fig. 9b to d) as components of these heating means, these either by direct Current flow or attached heating elements are designed to be heatable. The aforementioned heat dissipation ribs preferably extend in the direction of the air flow and/or are preferably designed as flow guide elements. An optional embodiment provides, for example, the flow guide elements with Flow breakaway elements or edges to generate local turbulence, which preferably does not extend to the entire flow cross-section, in an otherwise preferably laminar basic flow. In the case of an open-pored metal foam or a screen fabric, stall elements are given solely by their complex structure. Turbulence serves in particular to break down the thermally insulating flow boundary surfaces on a surface in which the flow occurs and thus increase the heat transfer that can be achieved. On the other hand, large-volume turbulence, which extends to the entire flow cross-section or an entire partial cross-section and/or dominates the otherwise prevailing laminar flow, also increases the risk of reflux effects and thus unwanted mixing of sterilized and non-sterilized aerosol components and/or uneven heat transfer on the aerosol components. b) UV light sources with an effective range in the flow channel: The aim is to capture the entire air flow conducted through the flow channel using the UV light source, preferably a UVC light source, with the aerosol-containing air being irradiated directly. For this purpose, at least one UV light source is preferably arranged in the flow channel. The effective area of these UV light sources is located in the flow channel and covers preferably the whole, more preferably a complete and preferably also a separate flow cross section for each of these UV sources, which emphasizes a serial arrangement of the sources in the flow direction as a particularly preferred embodiment. In order to avoid unacceptably high exposure to UV radiation in the immediate vicinity, the UV light sources and/or the effective areas of these are preferably optically separated from the suction opening and preferably shielded from the exhaust vent. c) at least one means for a plasma discharge with an effective area in the flow channel:

The aim is to capture the entire air flow conducted through the flow channel by the plasma discharge, with the aerosol-containing air being irradiated directly, as is the case with UV radiation. For this purpose, at least one plasma discharge is preferably arranged between at least two electrodes, which can optionally also be configured as electrically insulated or preferably electrically conductive flow guide surfaces, in the flow channel. Optionally, several plasma discharges in the through-flow channel are also proposed, preferably in series, with a fanning out into sub-channels also in parallel. Their effective areas are located in the flow channel and preferably cover a complete and preferably separate flow cross-section for each of these plasma discharges, which emphasizes a serial arrangement of the plasma discharge sources in the flow direction as a particularly preferred embodiment. d) at least one microwave source with an effective range in the flow channel:

The aim is to use the microwave source to record the entire air flow passed through the flow channel, with the aerosol-containing air being irradiated and heated by the microwaves. The microwaves either heat the aerosol in the air directly or indirectly via radiated heat-conducting elements, which are adapted in terms of their design, in particular their choice of material, to the radiated microwave length with regard to their coupling properties. A particularly advantageous embodiment is shown in FIG. 10a and b with an embodiment of the means for sterilization by means of UVC LEDs and waste heat conducting plates. It provides a device which, as means for sterilization, provides at least one UV light source (UV radiation source, generally also including UVC light source or UVC radiation source), in the example a UVC LED 37, as well as additional heating means.

The at least one UV light source and the heating means preferably have active areas arranged in series. More preferably, several UV light sources and then at least one heating means are arranged in series in the flow channel, with each of these effective areas more preferably spanning the entire flow cross section.

Fig. 10a shows a schematic side sectional view with a flow channel 13 guided in a U-shape around a circuit carrier 36. In this embodiment, it is particularly advantageous to combine the at least one UV light source (UVC-LED 37) and the heating means in terms of apparatus, with the Hei zmittel comprise means for heat dissipation (cooling fins 38) of waste heat from the at least one UV light source. UVC LED and cooling ribs are each arranged on one side of the circuit carrier 36, the cooling ribs being arranged parallel to the flow in the flow direction and in the flow channel preferably up to just before the arrangement of the UVC LED, d. H . also extend in the area of the flow deflection 28 . They preferably also thermally detect the outer walls in the flow deflections, on or via which aerosol components preferably accumulate. An open-pore foam element 33 prevents light from escaping from the exhaust air opening; the fan 7 ensures the flow. It is optionally proposed to additionally arrange at least one Peltier element as an electrothermal converter on circuit board 36 between foam element 33 and cooling fins 38 in such a way that the heat-absorbing pole of the Peltier element is coupled to the foam element and the heat-emitting pole of the Peltier element is coupled to the cooling fins is coupled . Heat is thus withdrawn from the air flow from the foam element and thus from the sterilized air flow leaving the exhaust opening, which is then added as additional heating of the non-sterilized air flow drawn in via the suction opening via the cooling fins.

Fig. 10b shows a specific embodiment of a module with circuit carrier 36 without housing, fan and foam element, but with six UVC LEDs 37 arranged in series and three cooling fins 38 arranged parallel to one another under the circuit carrier and electronic control components 39.

The waste heat from the UV light sources can thus be used in a particularly advantageous manner for further sterilization of the air flow. A particularly preferred embodiment provides in the context of which at least one UV light source and the heat dissipation structure on at least one circuit board such. B. to be arranged on a circuit board in or on the flow cross-section, more preferably the at least one UV light source being arranged on one side and the heat dissipation structure on the other side of the at least one circuit carrier and the flow channel adjoining both sides of the circuit carrier.

The configuration of the in Fig. 10b illustrated circuit carrier is preferably suitable as a module for a parallel connection order with additional circuit carriers . It is also proposed that the flow cross section should be made rectangular and not round.

This embodiment is therefore particularly well suited for integration into a device that can be used as a mobile tabletop device. The suction opening 4 is preferably located below the people's breathing openings (mouth and nose). Here, too, the suction opening and exhaust air opening 6 are preferably not only close to one another, but also directed parallel to one another onto the suction volume 14 . In the exemplary embodiment, the housing 5 also has parallel upper and lower sides, with which the device can be used in a particularly advantageous manner as a support for objects such as B. can also be used as part of a warming plate for food.

Alternatively, this embodiment or just the aforementioned arrangement of the Peltier elements can be integrated into a flow deflection arrangement according to FIG. 8a, with preferably a separate module for each flow deflection in accordance with FIG. 10b can be provided (serial arrangement).

List of references:

1 device

2 table or worktop

3 persons

4 suction opening

5 vertically oriented tubular housing

6 exhaust vent

7 fan

8 cover plate

9 Intake opening with trumpet-shaped widening flow cross-section

10 means of sterilization

11 Open vessel

12 annular gap volume

13 flow channel

14 suction volume

15 vertical flow channel section

16 partition plate

17 Lower case half

18 Upper case half

19 means of redirection

20 baffle

21 intake gap

22 passage opening

23 deflection trough

24 separation surface

25 Electrostatic field

26 electrodes

27 Aerosol Components

28 flow deflection

29 mass force separator

30 separation areas

31 filter surface 32 UV radiation source

33 foam element

34 flowable or flowable elements

35 heat dissipation fin 36 circuit board

37 UVC LEDs

38 cooling fin

39 control components

Claims

Device (1) for the local sterilization of aerosol-containing air, comprising a) at least one flow channel (13) with one or more flow cross sections, b) at least one fan (7) for generating an air flow in the flow channel, c) means for Sterilization (10) of at least one aerosol in the air flow, d) at least one suction opening (4) for the aerosol-containing air into the flow channel and e) at least one exhaust air opening (6) for a sterilized air flow out of the flow channel, f) the at least one suction opening opens into at least one suction volume (14), each of the at least one suction volume adjoining an aerosol source. Device according to one of Claims 1, characterized in that the at least one exhaust air opening (6) opens directly into the at least one suction volume (14). Device according to Claim 1, further comprising at least means for deflecting (19) the air flow as return air flow in the direction of the at least one suction opening (4) or the at least one suction volume (14) at the at least one suction opening (4). Device according to Claim 3, characterized in that the deflection means (19) comprises at least one deflection plate (20) or a deflection channel. Device according to Claim 3 or 4, characterized in that the deflection means (19) open out or are directed directly into the at least one suction volume (14). Device according to Claim 3 or 4, characterized in that the aerosol sources are positioned between the deflection means (19) and the at least one suction opening (4). Device according to one of the preceding claims, characterized in that the device (1) is arranged above a table or worktop (2) or a walk-in room and the suction opening (4) points downwards. Device according to claim 7, comprising a vessel (11) which is open at the top and into which part of the device (1) including the suction opening (4) is inserted to form an annular gap volume (12). Device according to one of the preceding claims, characterized in that the device (1) is arranged underneath a floor, table or worktop (2) and the suction opening (4) points upwards through the floor, table or worktop , Device according to claim 9, characterized in that above the suction opening (4) spaced to form a circumferential suction gap (21) a cover element, preferably a cover plate (8) is arranged. Device according to Claim 9 or 10, characterized in that passage openings (22) through the bottom, Table or worktop (2) arranged under the suction volume (14) and preferably a deflection trough (23) under the floor, table or worktop, the exhaust air opening (6) and the passage openings are provided. Device according to one of the preceding claims, characterized in that the exhaust air opening (6) is connected to an exhaust air duct system, the fan (7) being part of the exhaust air duct system. Device according to one of the preceding claims, characterized in that the at least one fan (7) is arranged in the flow channel (13) preferably between the sterilization means (10) and the exhaust air opening (6) and/or in front of the sterilization means and the exhaust air opening . Device according to one of the preceding claims, characterized in that the means for sterilization (10) comprise means for separating the at least one aerosol in the air flow. Device according to Claim 14, characterized in that the means for separating comprise at least one separating surface (24) for the aerosol. Device according to Claim 15, characterized in that an electrostatic field (25) extends between two electrodes (26) over at least part of the at least one separating surface (24), the electrostatic field extending at at least one point in the flow channel (13 ) extends over the entire flow cross-section. 17. Device according to claim 16, characterized in that one of the electrodes (26) is formed by at least part of the at least one separating surface (24).

18. Device according to one of claims 15 to 17, characterized in that between the at least one intake opening (4) and the electrostatic field (25) at least one lonisierungsstuf e is arranged, which detects the air flow in the entire flow cross section.

19. Device according to one of claims 15 to 18, characterized in that at least part of the at least one separating surface (24) has coolant for a surface temperature of less than 10°C.

20. Device according to one of claims 14 to 19, characterized in that the means for separation comprise at least one inertial force separator and/or a filter surface (31) spanning the flow cross section.

21. Device according to claim 20, characterized in that the at least one mass force separator and/or the filter surface (31) forms or has at least one separate separation surface for the at least one aerosol.

22. Device according to one of claims 15 to 21, characterized in that the means for sterilization (10) a) an electrostatic plasma field over the separation surfaces and/or b) a heating means for heating the medium flowing through to a temperature of over 40 °C , preferably greater than 70°C and/or c) at least one UV radiation source (32), preferably UV LEDs or a gas discharge lamp, preferably a mercury gas discharge lamp, comprising, with a wavelength between 180 and 410 nm, preferably between 220 and 280 nm, and/or d) a microwave source for Heating the include at least one deposition surface.

23. Device according to one of the preceding claims, characterized in that means for sterilization (10) comprise at least one heating means with an effective area in the flow channel (13).

24. The device according to claim 23, characterized in that the heating means comprises heat dissipation ribs (35) or an open-pored foam element (33), preferably made of metal, or a screen or screen fabric in the flow channel.

25. The device according to claim 24, characterized in that the heat dissipation ribs (35) are formed by flow line elements.

26. Device according to one of claims 23 to 25, characterized in that the heating means comprises at least one resistance heating element.

27. Device according to one of the preceding claims, characterized in that means for sterilization (10) comprise at least one UV light source (32, 37), preferably a UVC LED (37), with an effective range in the flow channel (13). 28. Device according to claim 27, characterized in that the at least one UV light source additionally comprises heating means.

29. Device according to claim 28, characterized in that the at least one UV light source and the heating means have active areas arranged in series.

30. Device according to claim 28 or 29, characterized in that the heating means comprise means for heat dissipation (35, 38) of waste heat from the at least one UV light source (32, 37).

31. Device according to claim 30, characterized in that the at least one UV light source (32, 37) and the heat dissipation structure (38) are arranged on at least one circuit carrier (36) in or on the flow cross section (13).

32. The device according to claim 31, characterized in that the at least one UV light source (37) is arranged on one side and the heat dissipation structure (35, 38) on the other side of the at least one circuit carrier (36) and the flow channel (13) on both sides of the circuit board is adjacent.

33. Device according to one of the preceding claims, characterized in that means for sterilization (10) comprise at least one means for a plasma discharge with an effective area in the flow channel (13).

34. Device according to one of the preceding claims, characterized in that means for sterilization (10) at least one microwave source with effective range in Flow channel (13) include. Device according to one of Claims 23 to 34, characterized in that the effective area completely spans the flow cross-section at at least one point.