WO2022106162A1

WO2022106162A1 - Sterilization device

Info

Publication number: WO2022106162A1
Application number: PCT/EP2021/079757
Authority: WO
Inventors: Ralf Wnuk; Markus Olschok; Martin Kampmann; Michael Berwanger
Original assignee: Hydac Process Technology Gmbh
Priority date: 2020-11-19
Filing date: 2021-10-27
Publication date: 2022-05-27
Also published as: EP4164703A1; DE102020007052A1

Abstract

The invention relates to a sterilization device, in particular for the treatment of gaseous media, such as ambient air, for rendering harmless and removing microorganisms from a media flow, at least comprising a separating device (10), through which the media flow is guided, and a killing device (12) located downstream thereof, as viewed in the direction of the media flow, along which the media flow is at least partially extending.

Description

sterilization device

The invention relates to a sterilization device, in particular for the treatment of gaseous media, such as room air, for the purpose of removing microorganisms and rendering them harmless. The microorganisms for the purposes of this invention include bacteria, for example lactic acid bacteria, various types of fungi, for example baker's yeast, microscopic algae such as chlorella and protozoa, including paramecium but also the malaria pathogen Plasmodium. It is controversial in the professional world whether viruses can also be counted among the microorganisms, since they are not regarded as living beings due to their lack of metabolism; Nevertheless, virus research, i.e. virology, is regarded as a sub-area of microbiology and accordingly viruses, such as the SARS corona virus, should belong to the microorganisms in the sense of the definition of the term.

The claimed sterilization device is intended to sterilize, sterilize or sterilize room air in order to free it from microorganisms, including viruses, in order to such To protect people who are in rooms with appropriate room air from illness. The state achieved by means of the sterilization device for the room air is referred to as sterile and the term germ-free used in this respect in the application should take the place of sterile, even if this is fundamentally incorrect, because sterilization is not just about The removal or killing of certain stages of development of microorganisms, namely germs, but the removal or killing of all microorganisms at every stage of development, which by definition also includes viruses such as the SARS coronavirus.

Filter-based cleaning devices have already been proposed in practice to combat viruses in the room air, such as the corona virus, with even so-called HEPA filters being too coarse and the virus itself too small to be reliably caught. Standard HEPA filters can trap particles up to 0.3 fjm, although the diameter of SARS-CoV-2 is only around 0.1 fjm and therefore cannot be filtered out of the room air with HEPA filters. Instead of HEPA filters, other, different room air filters are used

(EP 0 687 195 B1), in particular in the form of a multi-layer filter material made of synthetic fiber non-woven fabric with at least two layers having different properties, of which the first layer is designed as a coarse filter layer and at least one further layer is designed as a fine filter layer; the degree of separation achieved in this way alone is not suitable for small-sized microorganisms such as viruses.

Furthermore, it has already been suggested that destroying coronavirus by ultraviolet light emitted from a light source as a killing means, due to its photonic action, should destroy the DNA bonds of the virus; alone the problem is that to eliminate many viruses, a comprehensive, high-energy irradiation over many minutes is necessary to enable effective disinfection, which is not guaranteed in larger building complexes, which also include driver cabins of buses in the local transport system or trains. The systems used in Shanghai for cleaning buses in the local transport system have not proven themselves (The Star [https://www. thestar.com.my/tech/tech-news/2020/03/17/on-mission -to- e rad i cate-v iru s-germ sc hin af i rm s-see-t h e-u v- 1 ight] ) .

Proceeding from this state of the art, the invention is based on the object of creating a sterilization device which is improved in comparison thereto and which makes it possible to remove microorganisms, including viruses, from the ambient air to a large extent. A pertinent task is solved by a sterilization device with the features of patent claim 1 in its entirety.

Because the room air is fed as a media flow to a separating device and to a subsequent killing device, viewed in the direction of the media flow, along which the media flow runs at least partially, volumetrically small parts of the room air come into direct contact with both the separating device and with the media flow that is formed the killing facility. A further advantage of the media flow guidance both via the separating device and subsequently via the killing device can be seen in the fact that coarser impurities including fine dust pollution, such as aerosols, are separated from the room air by means of the separating device and the room air cleaned in this way protects the subsequent killing device from contamination, so that the biological material remaining in the media flow, in particular in the form of microorganisms, can be killed better through direct contact. Aerosols are a heterogeneous mixture (dispersion) of solid or liquid suspended particles in a gas and, as a dynamic system, are subject to constant changes through condensation of vapors on existing particles, evaporation of liquid components of the particles and coagulation of small particles into large particles or separation of particles on surrounding objects, such as the separator here.

Various ways of killing biological material can be used as a means of killing the microorganisms, including viruses and germs, such as microwave radiation, ionized radiation, electron beam-based sterilization and the use of corresponding killing gases such as ozone. Gravity separators such as centrifugal separators or membrane systems with an osmosis effect can be used as the separating device. Killing within the meaning of the invention is to be equated with sterilization or sterilization.

However, it has proven particularly advantageous, functionally reliable and cost-effective to form the separating device from at least one filter element and the killing device from at least one UV radiation device, preferably from a UV-C radiation device. It is particularly advantageous to select the filter element with its filter medium with a filter class F7 to F9, particularly preferably F9 according to EN779 and EN 1822, so that the minimum requirements of the hygiene regulation VDI 6022 are met and such filters in such classes are regularly used as pre-filters for clean room systems , with a filter possibility for particles in the order of 1 to 10 fjm. In terms of filter performance, a HEPA filter would also be an advantage here; due to its high retention capacity, such a filter alone is not very permeable for a media flow that is to be guided, ie the HEPA filter leads to high pressure losses as part of the transport of the room air, what this more difficult and would significantly reduce the air flow through the sterilization device. In contrast, the air filter of filter class F9 that is preferably used here has a minimal pressure loss; nevertheless reliably separates aerosols including fine dust and coarser particulate contaminants from the media flow, so that the room air media flow cleaned in this way is exposed to the best possible irradiation by the UV reactor in order to be able to eliminate the microorganisms as a killing device as completely as possible. In this respect, the radiation device is also not clogged with dirt during operation, so that the full radiation power is always available for killing.

Depending on the required filter surface, the filter element can be designed with a correspondingly large volume and, in particular, the filter element can be easily adapted to the circumstances via its element length. It is also possible to switch several elements in parallel or one behind the other, seen in the direction of media flow.

A filter element with an activated carbon layer, for example, could help to remove unpleasant odors from the room air at the same time. It is interesting to know in this context that viruses, including the SARS corona virus, need water or moisture to survive, and the filter element can accordingly be modified in such a way that moisture in the media flow is retained in the separating device. For this purpose, the filter element can be provided, for example, with a hydrophilic coating as part of a plasma application process, or it is supported on its inner peripheral side on a molecular sieve, which serves as a coalescence element for separating water in the media flow. It is particularly advantageous to arrange the UV radiation device downstream of the respective filter element in the media flow, so that the filter element on its clean side experiences a further germ-killing effect by means of the UV radiation when there is a flow from the outside to the inside. In this regard, it can be advantageous that the filter element radially comprises a rod-shaped UV radiation device, preferably in a coaxial arrangement.

If the filter element is contaminated, in particular by biological material such as microorganisms, it must be disposed of, for example incinerated and exchanged for a new element. Since UV radiation can damage the skin and eyes of a person operating the device and has been proven to be carcinogenic, it must be ensured that the UV radiation device is switched off when changing the filter element. For this purpose, when removing or replacing the filter element from the sterilization device, a switch can be actuated, which stops the flow of current to the UV radiation device. If the sterilization device according to the invention advantageously works with short-wave UV-C radiation in the range of around 222 nanometers, this entails fewer risks for the operator than the UV devices currently on the market with wavelengths of around 254 nanometers. This is due to the lower penetration depth of the 222 nanometer wavelength in the eye and skin, whereby the radiation input is still sufficient to reliably kill microorganisms including viruses. If necessary, the sterilization device according to the invention can also be operated with a wavelength of 254 nanometers.

In a further preferred embodiment of the sterilization device according to the invention, it is provided that it is designed as a stand-alone device with a vertical orientation and has a jacket that encompasses the UV radiation device and that a filter element on the side assigned to the media flow turned side is arranged in extension of the coat. The stand-alone device according to the invention with a vertical orientation can be set up in rooms of any size to save space and can also be easily taken to other rooms due to its low weight, for example when a meeting is taking place elsewhere. It is also possible to use the device as a built-in device in all types of driving cabins, including on passenger ships.

The interior of the jacket on the outer circumference specifies the flow direction for the room air medium flow and in this way enables a largely laminar flow past the UV radiation device. If necessary, turbulators can also be attached inside the jacket, which lead to turbulence in the air flow and thus to a longer dwell time of the media flow in the housing jacket of the device formed in this respect.

In a further preferred embodiment of the sterilization device according to the invention, it is provided that the casing is accommodated within a carrier device which extends from a base plate to an end cap receptacle for the filter element. Since essentially the support device bears the installation load for the device, the casing can be designed to be extremely thin-walled and therefore light. It is preferably also provided that between the base plate and a central outlet opening of the casing for the media flow, between individual rods of the carrier device, a passage space is created, which opens into the environment. In this way, the sterilization device can be designed as a stand-alone device in such a way that at eye level (approx. 1.6 m) the suction of the space formation in the form of the media flow takes place and the Euft cleaned of microorganisms is released near the floor, so that with the thermally induced re-ascent of the Room air outside of the device for multiple cleaning creates a circulation flow, In any case, in a partial flow, cleaned air gets back into the room as a whole and combines with the rest of the room air accordingly through gas exchange.

In a further particularly preferred embodiment of the sterilization device according to the invention, it is provided that a fan device is used to generate the flow of media. It is preferably provided that the fan device is arranged in a receptacle in the lower third of the jacket, which is adjacent to the outlet opening. The fan device is accordingly designed as a suction fan, which draws the room air from the environment into the interior of the filter element and from there past the UV radiation device until it is released again to the environment via the lower central outlet opening of the jacket or the sterilization device. Depending on the fan output, very high throughput rates of air to be treated can be achieved by means of the sterilization device and by the chambers of the fan device, in particular via the jacket and the filter element, which also has a dampening effect, unpleasant operating noises in the installation room are avoided. Depending on the fan output and the associated noise level, it is also planned to attach an additional damping jacket around the sterilization device as a whole. Furthermore, there is the possibility of meeting increased design requirements by attaching such an additional insulating jacket or by putting a type of foam stocking on the sterilization device and adapting the sterilization device tastefully to its respective operational environment through design design.

In the following, the sterilization device according to the invention is explained in more detail using an exemplary embodiment.

Here, in principle and not to scale representation show the 1 and 2 show a side view and a plan view of the sterilization device;

3 and 4 show a section along the line A-A in FIG. 1 and a perspective longitudinal section of the device according to FIG. 1; and

5 and 6, in an enlarged representation, an element receptacle of the casing for the filter element or the casing receptacle in a carrier device with longitudinal rods.

FIGS. 1 to 4 show the sterilization device as a whole in the form of a device that can be placed on a floor. The sterilization device shown is used in particular for the treatment of gaseous media such as room air, ie the air used in a room such as a building room. The sterilization device is used to remove and render harmless microorganisms from a media flow that flows through the sterilization device. In particular, the sterilization device has a separating device 10 through which the media flow is routed and there is also a killing device 12 which, seen in the direction of the media stream, follows the separating device 10 and along which the media stream is at least partially routed.

The separating device 10 consists of a filter element 14 whose element material 16 is shaped as a hollow cylinder and extends between two end caps 18 and 20 . The upper end cap 18 forms a kind of closed cover part, which is designed circular according to the plan view in FIG. The lower end cap 20, on the other hand, accommodates the element material 16, forming a kind of receiving ring and, with its hollow-cylindrical design, forms a circular through-opening 22 in the middle. At least that is the task of the separating device 10 or the filter element 14 to partially remove microorganisms including viruses from the media flow along with particulate contamination including aerosols. Any microorganisms still remaining in the media flow are then predominantly impaired in their biological effectiveness by the killing device 12, preferably completely killed, in that the killing device 12 destroys the bond within the DNA strands of the respective microorganism.

As shown in particular in FIGS. 3 and 4, the killing device 12 is formed from at least one UV radiation device 24, preferably from a UV-C radiation device. The sterilization device, which is designed as a stand-alone device with a vertical orientation, has a cylindrical casing 26 which encompasses the UV radiation device 24, with the respective filter element 14 being arranged on the side facing the media flow at the inlet, as an extension of the casing 26 when viewed in the direction of the figures . As shown in particular in FIG. 1, the jacket 26 is accommodated within a carrier device, designated as a whole by 28 , which extends from a base plate 30 to an end cap receptacle 32 for the lower end cap 20 of the filter element 14 . In the present case, the carrier device 28 consists of three individual rods 34 which run parallel to one another and at equal radial distances from one another in the longitudinal direction of the sterilization device. As can also be seen, the jacket 26 is formed from a band-shaped jacket track and is wound up to form a helix 36 . The respective rod 34 is accommodated with its upper end in the end cap receptacle 32 as shown in FIG. The lower end of the respective rod 34 opens out on the front side under contact with the base plate 30 (see FIG. 3).

Between the base plate 30 and a central outlet opening 38 of the shell 26 for the outlet of the media flow between the individual rods 34 of the carrier device 28, a passage space 40 is created, the out into the environment. According to the illustration according to FIGS. 3 and 4, the UV-C radiation device 24 is formed from a UV tube 42 which is accommodated in holders 44 at the end and preferably extends in the longitudinal axis of the cylindrical casing 26 .

A fan device 46, which is arranged in a receptacle 48 in the lower end area of the jacket 26 and adjoins the outlet opening 38, serves to generate the media flow. The fan device 46 is driven electrically by an electric motor and sucks the room air from the outside in through the filter element 14. The medium flow, which is then partially cleaned in this way, is guided in a laminar manner on the inside of the jacket 26 and thus along the UV tube 42. To supply the electric fan device 26 and to supply the UV tube 42 is a power supply 50, which is inserted into the hollow-chamber-like base plate 30, weighs it down and to this extent stabilizes the sterilization device as a stand-alone device in its set-up position.

The filter element 14 with its element material 16 forms a kind of hollow cylinder, in which case the element material 16 can also be pleated, ie provided with individual folds. The element material 16 has a molecular sieve (not shown in detail) on its inside for support, which is used for water separation in order in this way to remove the basis of life for the microorganisms. An electrical connection, not shown in detail, with a supply voltage of 230 V, for example, which is fed in via the power pack 50, is sufficient for the electrical power supply. The air is preferably sucked in via the filter element 14 at eye level (approx. 1.60 m) and the filtered air is released near the floor by being released via the lower passage space 40. The air is heated during operation of the UV-C Radiation device 24. This heating also leads to air circulation in the room and improved distribution of the cleaned air in the room environment. The UV-C tube 42 or emitter preferably has an output of approx. 120 watts at an operating temperature of 40-55°C.

As can be seen from FIG. 5, the end cap receptacle 32 is formed from a ring with an inner peripheral part 52 and an outer peripheral part 54. The rod 34 or longitudinal rod shown is designed as a hollow rod and lies at least partially on the inside on the outer peripheral side in the upper end area of the outside peripheral part 54 . Also, the upper end of the rod 34 abuts a flat end surface 56 on the underside of the end cap receptacle 32 . The pertinent contact area is pierced by a countersunk screw 58 which is screwed with its thread length into a threaded sleeve 60 which is introduced into the upper free end of the rod 34 . In this way, the rod 34 can be fixed in a defined manner on the end cap receptacle 32 by means of the countersunk screw 58 .

5 also partially shows the lower end of the filter element 14 together with the associated lower end cap 20. The end cap 20 in question is placed on the end cap receptacle 32 from above and runs there along a flat outer peripheral surface of the inner peripheral part 52, which is located in this Area has a circumferential sealing ring 62 in a recess. The pertinent sealing ring 62 presses with its prestressing force on the inner peripheral side of the lower end cap 20 and in this way holds the filter element 14 in its receiving position shown in the figures. In this respect, the end cap receptacle 32 with the sealing ring 62 as a whole forms a holding device 64, for holding the filter element 14 in its operating position on the jacket 26 and in the event of an exchange for a new element, the filter element 14, as viewed in the direction of the figures, only has to be be pulled off at the top, against the holding force of the sealing ring 62 and the new element is then pressed again against the elastic effect of the sealing ring 62 into its receiving position or functional position. In this way, the filter element 14 can be easily replaced if necessary. The shell 26 also ends with its upper free end at the planar end surface 56 of the end cap receptacle 32 and is fixed to it, for example, by gluing or by means of a welded connection. A conventional cable bushing 66 extends through the upper area of the relevant casing 26, with the cable bushing 66 opening out into the interior of the adjacent hollow rod 34 and in this way a cable routing from the power supply unit 50 via the rod 34 and the cable bushing 66 to a plug part 68 of the UV -Tube 42 allows. For the sake of simplicity, the electrical connecting cable has not been shown. The connector part 68, together with the UV tube 42, is, as already explained, received by a holder 44, which is supported on the inner circumference of the casing 26 and is connected to it in a fixed position.

Seen in the direction of Figure 4, two such cable bushings 66 can be provided in the lower part of the jacket 26; once for the electric fan device 46 and once for the connection to the lower end of the UV tube 42 in the area of the lower holder 44 pertinent cable guides in turn emanate from the power supply 50, which is integrated in the base plate 30.

The illustration according to FIG. 6 shows a lower receiving ring 70 through which the individual rods 34 are inserted axially, these being held in place by elastomer rings 72 which are pushed into the receiving ring 70 from the underside. Furthermore, the ring-shaped receptacle 48 is held on the inner peripheral side of the receiving ring 70 for fixing the fan device 46 in the jacket 26. In this area, a cable bushing 66 is additionally or alternatively available for the purpose of supplying electronic components with power from the power supply unit 50. In this respect, the jacket 26 with the rods 34, the receiving ring 70 and the base plate 30 forms a type of plug-in construction kit, in which the components can be easily separated from each other, for example, to be able to replace the UV tube 42 if necessary.

In order to prevent an operator from being unintentionally exposed to the radiation of the UV tube 42 when the filter element 14 is removed during operation, a switch actuation device (not shown in detail) is preferably provided, which ensures that when the filter element 14 is removed, the electrical supply to the UV tube is switched off 42 on the part of the power pack 50 is omitted, so that no harmful radiation can occur.

In this respect, the sterilization device according to the invention is modular and can be used with few components, which helps to save costs and weight.

Claims

Patent claims Sterilization device, in particular for the treatment of gaseous media, such as room air, for the purpose of removing microorganisms from a media flow and rendering them harmless, at least consisting of a separating device (10) through which the media flow is guided and a subsequent killing device, viewed in the direction of the media flow (12) along which the media flow runs at least partially. Sterilization device according to Claim 1, characterized in that the separating device (10) at least partially removes the microorganisms from the media flow and any microorganisms remaining in the media flow are predominantly impaired in their biological effectiveness by the killing device (12), preferably completely killed. Sterilization device according to Claim 1 or 2, characterized in that the separating device (10) is formed from at least one filter element (14) and the killing device (12) destroys the bond within the DNA strands of the respective microorganism. Sterilization device according to one of the preceding claims, characterized in that the killing device (12) is formed from at least one UV radiation device (24), preferably from a UV-C radiation device. Sterilization device according to one of the preceding claims, characterized in that it is designed as a stand-alone device with a vertical orientation has a jacket (26) that the UV radiation device device (24) and which comprises a filter element (14) on the side facing the medium flow on the inlet side as an extension of the casing (26).

6. Sterilization device according to one of the preceding claims, characterized in that the jacket (26) is accommodated within a carrier device (28) which extends from a base plate (30) to an end cap receptacle (32) for the filter element (14).

7. Sterilization device according to one of the preceding claims, characterized in that between the base plate (30) and a central outlet opening (38) of the jacket (26) for the outlet of the media flow between individual rods (34) of the carrier device (28) a passage space ( 40) is created, which flows into the environment.

8. Sterilization device according to one of the preceding claims, characterized in that a fan device (46) is used to generate the media flow.

9. Sterilization device according to one of the preceding claims, characterized in that the fan device (46) is arranged in a receptacle (48) in the lower third of the casing (26) which is adjacent to the outlet opening (38).

10. Sterilization device according to one of the preceding claims, characterized in that the filter element (14) forms a kind of hollow cylinder which is placed in an exchangeable manner via a holding device (64) on the upper end of the jacket in the operating position.