Method and device for reducing the pathogenicity of pathogens, in particular parasitic molecules, contained in ambient air

Abstract

Method for reducing the pathogenicity of pathogens, in particular parasitic molecules, contained in ambient air, in which ambient air containing pathogens is drawn in from the environment on the suction side by means of a compressor (1) and compressed to a pressure of at least 250 kPa and then the air, reduced in its pathogenicity and again reduced to ambient pressure, is released into the environment, wherein the ambient air containing pathogens is passed through a heat exchanger (2) by means of the compressor (1) and heated with a heat pump and the compressed air is kept at a pressure of at least 250 kPa and at a temperature of at least 80 °C and at most 150 °C for a residence time of at least 50 s and is then released back into the environment by flowing through the heat exchanger (2).

Description

[0001] The invention relates to a method and a device for reducing the pathogenicity of pathogens, in particular parasitic molecules, contained in ambient air.

[0002] In particular, viruses can be influenced in their pathogenicity or even rendered ineffective, so that they can no longer cause infections in living beings.

[0003] In principle, the invention can be used in a wide variety of enclosed spaces where high hygiene requirements exist or where large gatherings of people may occur. It is also suitable for scientific applications, for example, in testing the activity of germs.

[0004] In principle, it is known that the pathogenicity of living pathogens can be influenced by sufficient heating. To do this, the ambient air must be heated to a sufficiently high temperature. Various options are known for this. The problem, however, is that the heated air must be released back into the environment, which would lead to undesirable heating, for example of an interior space, if no countermeasures are taken. The treated air is usually subjected to additional external cooling. This increases the energy requirement if it has to be actively operated. In any case, however, a larger volume is required, since in addition to the components for heating the ambient air, a more or less large volume is required for cooling the previously heated and uncontaminated or significantly less contaminated air, which is then released back into the environment.If no active additional cooling is used, a larger volume is required, which means that a correspondingly large free space must be available or made available in order to allow sufficient cooling of the treated air before being returned to the respective enclosed space, without significantly increasing the temperature of this space.

[0005] For example, US 2021 / 0247080 A1 discloses a system and a method for treating contaminated air.

[0006] US 2010 / 0316535 A1 concerns a decontamination system and a corresponding method.

[0007] JP 2020-185265 A describes a compressed air circulation system.

[0008] It is therefore an object of the invention to provide possibilities for achieving a high degree of reduction in the pathogenicity of ambient air containing pathogens, while at the same time using energy economically and requiring a small volume, which is additionally required for carrying out the method according to the invention, as well as maintaining a maximum of a slight increase in the temperature in the respective closed space from which the respective ambient air is extracted and returned for carrying out the method.

[0009] According to the invention, this object is achieved by a method having the features of claim 1. Claim 10 defines an apparatus for carrying out the method. Advantageous further developments and embodiments can be realized with features defined in the dependent claims.

[0010] When carrying out the process, ambient air containing pathogens is sucked in from the environment on the suction side by means of a compressor and compressed to a pressure of at least 250 kPa, preferably at least 300 kPa, and then the air, reduced in pathogenicity and reduced to the ambient pressure, is released into the environment.

[0011] At least with an axial compressor, compressed air could only be released into the environment after a residence time of at least 50 seconds, during which the compressed air is maintained at a pressure of at least 250 kPa, preferably at least 300 kPa. For this purpose, the compressed air can be fed through a sufficiently long line or maintained at pressure in at least one chamber before the air is expanded and released into the environment.

[0012] If a piston compressor is used, the air can also be maintained at the specified pressure for the aforementioned residence time. However, this is not absolutely necessary, as the desired effect on pathogens can already be achieved during the compression strokes. For this purpose, the piston compressor should be operated at a speed of at least 10 rpm.

[0013] During compression, the ambient air containing pathogens is also forcibly heated so that pressure and temperature together can exert the desired effect on the pathogens.

[0014] For expansion, the compressed treated ambient air can be released into the environment via an expansion valve or first fed to a heat exchanger.

[0015] The ambient air containing pathogens sucked in by the compressor is sucked into a heating system and passed through a heat exchanger. The ambient air is then heated by a heat pump and released back into the environment by flowing through the first heat exchanger.

[0016] The ambient air within the heating system should be maintained at a temperature of at least 80 °C and a maximum of 150 °C with a residence time of at least 50 s before flowing through the heat exchanger and being returned to the environment with reduced pathogenicity. After the residence time, this air will then flow through the heat exchanger and be released back into the environment.

[0017] The ambient air treated in this way should be discharged into the environment at a maximum temperature of 50 °C, preferably a maximum of 35 °C, and most preferably a maximum of 25 °C.

[0018] After flowing through the heat exchanger, the pathogen-containing ambient air can be heated to a temperature of more than 50 °C and up to 85 °C through heat recovery before it enters the heat pump or compressor. The latter aspect applies if a heat pump is not used.

[0019] After flowing through the heat exchanger, the pathogen-containing ambient air can be guided through a condenser heat exchanger unit to the compressor and from there, via at least one line, returned to the heat exchanger, where the pathogen-containing ambient air drawn in from the environment has been preheated before entering the condenser heat exchanger unit, and the pathogen-reduced ambient air returned to the environment is cooled. In the condenser heat exchanger unit, the pathogen-containing air can be further heated by the refrigerant heated by the refrigerant compressor, whereby air temperatures in the range of 70°C to 105°C can be achieved.

[0020] In the heat pump, the refrigerant is fed to a condenser-heat exchanger unit via the refrigerant compressor. In the condenser-heat exchanger unit, the refrigerant is partially condensed and heat is released to the ambient air containing pathogens that is drawn in. The partially condensed refrigerant is fed to a condenser via a line and from the condenser, via an expansion valve and a second valve, either returned in the circuit directly via an evaporator to the refrigerant compressor or, by means of the second valve, via an evaporator-heat exchanger unit during the return to the refrigerant compressor into the refrigerant evaporator and can thus be returned in the circuit. The second valve can be designed as a three-way valve, which is preferably controllable depending on the temperature of the ambient air exiting the heat exchanger and released into the environment.

[0021] In the line in which the heated ambient air containing pathogens flows from the compressor towards the heat exchanger and / or at least one chamber connected to this line, the ambient air heated to a temperature of at least 80 °C and a maximum of 150 °C should be kept with a residence time of at least 50 s before being fed to the heat exchanger and then discharged to the environment.

[0022] The ambient air, heated to a temperature of at least 80 °C and a maximum of 150 °C, should advantageously be held for a period of at least 60 s, preferably at least 120 s, and particularly preferably at least 180 s, before being fed to the heat exchanger to achieve a sufficient reduction in pathogenicity. The residence time can also be selected or adjusted depending on the specific pathogens present in the ambient air.

[0023] The chamber(s) can also be referred to as a dwell chamber(s), whose internal volume is sufficiently large to ensure the required dwell time for rendering pathogens harmless. The dwell chamber must also be designed so that an internal pressure of up to 1 MPa can be set.

[0024] To regulate the temperature of the ambient air in the line and / or in the at least one chamber, the refrigerant can be supplied via a first valve of the condenser heat exchanger unit or directly to the condenser for the refrigerant. The first valve can also be a three-way valve, with which the volume flow of refrigerant flowing through the condenser heat exchanger unit can be regulated. This makes it possible to influence the temperature of the pathogen-containing ambient air, which is to be maintained over the residence time required to reduce pathogenicity. In this case, no or additional heating of this ambient air is possible.

[0025] In the connecting line through which the refrigerant is fed from the second valve to an evaporator heat exchanger unit, and a third valve is integrated in this way, the refrigerant and ambient air drawn from the environment can be fed to a second evaporator heat exchanger unit. Following this, in the direction of flow, the refrigerant is fed to the evaporator and the ambient air to the heat exchanger. The reduced-pathogenicity ambient air, which is also fed to the evaporator heat exchanger unit, can be additionally preheated by the evaporator heat exchanger unit.

[0026] The residence time can preferably be influenced by the power at which the ambient air compressor is operated, the internal volume of the line between the compressor and the heat exchanger or the line and the at least one chamber, and the internal chamber pressure. The lower the flow velocity or the larger the respective internal volume, the longer the residence time of the ambient air heated to reduce pathogenicity can be maintained.

[0027] The heat pump may operate intermittently and / or the heating of the ambient air may not be carried out continuously in any other way.

[0028] However, continuous operation is also possible when carrying out the process.

[0029] The heated ambient air flowing through the line with the compressor can be alternately fed to individual chambers so that the minimum residence time of the ambient air, which is preferably heated to at least 80 °C, can be maintained. At least the residence time should be maintained; the temperature and pressure increase achieved by the compressor and / or the heat pump can be sufficient, so that this temperature of 80 °C does not necessarily have to be maintained in the chamber(s). For this purpose, suitable valves can feed the heated ambient air to individual chambers one after the other until each chamber is sufficiently filled and the required residence time has been achieved. An inlet valve of the respective chamber is then closed and a valve at the outlet of the chamber is opened so that the ambient air, now with reduced pathogenicity, can be returned to the heat exchanger.At the same time, an inlet to another chamber is opened to allow the inflow of sufficiently heated ambient air containing active pathogens, and the respective outlet is closed. This can be achieved sequentially with at least two, preferably three, chambers.

[0030] The heating system for the ambient air in the device is formed by the heat exchanger, the compressor, the line and / or the line and at least one chamber.

[0031] The heat pump consists of the refrigerant compressor, the condenser-heat exchanger unit, the condenser, the expansion valve, and the evaporator. The ambient air and the pathogen-reduced ambient air are directed countercurrently through the heat exchanger, and the pathogen-containing ambient air and the refrigerant are directed separately through the condenser-heat exchanger unit. The expansion valve should also be controllable.

[0032] In the heat pump circuit, there may be an additional second evaporator heat exchanger unit controlled by a third valve, through which the ambient air containing pathogens flows directly from the environment into the heating unit.

[0033] A first valve may be present in the heat pump circuit, with which refrigerant can be supplied from the refrigerant compressor to the condenser heat exchanger unit and / or directly to the condenser.

[0034] The chemical compounds or mixtures commonly used in heat pumps can be used as refrigerants. Isobutane, for example, has proven suitable.

[0035] With the invention, it is achieved in particular by the combined use of heat exchangers for preheating the ambient air containing pathogens using waste heat from the process and the use of a heat pump, which is used for the necessary heating of the ambient air containing pathogens and also for the further cooling of the ambient air to be discharged to the environment, in which the pathogenicity has been reduced, so that an undesirably high heating of the environment, in particular the respective closed space from which the ambient air containing pathogens has been sucked out, can be avoided. In particular, very little energy is required for cooling the ambient air, the pathogenicity of which has been reduced by heat treatment, before it is returned to the environment, if at all.

[0036] The sole use of a compressor (e.g., based on the principle of a piston compressor) is possible and advantageous, as the moving air volume is briefly compressed, heated, briefly held, and expanded. This can inactivate pathogens. With an axial compressor, options should be provided to ensure a sufficiently long residence time for the ambient air compressed and heated by the compressor.

[0037] In addition, a heat pump advantageously offers several possibilities for suitable tempering of the ambient air during the implementation of the method according to the invention, with which the respectively required temperatures can be set or maintained.

[0038] Another advantage is that no CO 2 -formation takes place and therefore no accumulation of it can be observed in the respective room or the environment.

[0039] The invention will be explained in more detail below using examples. It shows: Fig. 1 shows in schematic form, using a block diagram, an example of a device for carrying out the method.

[0040] For the sake of clarity, the treatment of the ambient air passed through the heating system will first be explained, as it is designed in this example.

[0041] The ambient air containing pathogens is sucked into the heating system via the air inlet by means of a compressor 1 and initially passed through the heat exchanger 2 at ambient temperature and atmospheric pressure, where it is heated to a temperature of up to 50°C as a result of heat absorption. The ambient pressure is maintained. From the heat exchanger 2, the preheated ambient air, still containing pathogens, is sucked through a condenser heat exchanger unit 3 to the compressor 1. In this condenser heat exchanger unit 3, further heating can be achieved by heat exchange with the compressed refrigerant to a temperature in the range of 70°C to 105°C when the refrigerant flows through the condenser heat exchanger unit 3 via the first valve 6.Compressor 1 further heats the ambient air so that an air temperature of 85°C to 150°C and a pressure increase of between 300 kPa and 15,000 kPa can be achieved. The heated and compressed ambient air enters one of the chambers 12.1, 12.2, or 12.3 via line 4, as explained in the general part of the description. After the required residence time has been observed, the still compressed, at least largely depathogenized, ambient air leaves the respective chamber 12.1, 12.2, or 12.3 and is passed through heat exchanger 2 in countercurrent to the pathogen-containing ambient air that was sucked in, whereby the temperature of this ambient air is reduced to a temperature in the range of 10°C to 60°C. In this example, the pre-cooled air, which is at least largely free of active pathogens, is passed through the first evaporator heat exchanger unit 15.There, further cooling to a temperature below 50 °C down to the ambient temperature can be achieved if expanded and condensed refrigerant flows through the first evaporator heat exchanger unit 15 via the second valve 9 for its evaporation and the ambient air is further cooled before the air outlet.

[0042] In this way, air with reduced pathogenicity or even pathogen-free air, which does not contain any active or activatable pathogens, can be released into the environment through the air outlet at a suitable temperature.

[0043] The heat pump forms a refrigerant circuit in which refrigerant is pumped through lines in a valve-controlled closed circuit by means of the refrigerant compressor 5. The refrigerant is compressed by the refrigerant compressor 5 to a maximum pressure of 3000 kPa and reaches the first valve 6. There, it has reached a temperature in the range of 80 °C to 150 °C. With the first valve 6, which can preferably be regulated depending on the temperature of the pathogen-containing ambient air preheated by the heat exchanger 2, refrigerant can be guided at a corresponding volume flow through the condenser heat exchanger unit 3 and / or directly to the condenser 7. The temperature and pressure remain within the range specified above.

[0044] Following the condenser 7, the refrigerant flows through the expansion valve 8. The pressure of the refrigerant is reduced to less than 1000 kPa and the temperature to between 4 °C and 14 °C. The expansion valve 8 should advantageously be adjustable depending on the refrigerant temperature.

[0045] With the second valve 9, which is also preferably controllable, the volume flows of the refrigerant can be influenced depending on the temperature of the ambient air flowing through the heat exchanger 2 in the direction of the air outlet, which can be led there either directly in the direction of the refrigerant compressor 5 or via the first evaporator heat exchanger unit 15.

[0046] In the line between the second valve 9 and the refrigerant compressor 5 there is a further fourth valve 16, with which a backflow of refrigerant into the first evaporator heat exchanger unit 15 can be avoided.

[0047] In this example, a third valve 13 can optionally be arranged in the line between the second valve 9, upstream of the evaporator 10 for refrigerant. Cold refrigerant can flow via the third valve 13 to the second optional evaporator-heat exchanger unit 14 and through it towards the evaporator 10. There, the pathogen-containing ambient air flowing into the heating system through the air inlet can be tempered before entering the heat exchanger 2, if necessary. The refrigerant enters the second optional evaporator-heat exchanger unit 14 at a temperature between 4 °C and 14 °C and a pressure of less than 1 MPa.

[0048] All temperature and pressure data refer to isobutane as the refrigerant. Reference symbol 1 compressor 2 heat exchangers 3 Condenser heat exchanger unit 4 Line 5 refrigerant compressors 6 first valve 7 capacitor 8 expansion valve 9 second valve 10 evaporator 12.1 chamber 12.2 chamber 12.3 chamber 13 third valve 14 second evaporator heat exchanger unit 15 first evaporator heat exchanger unit 16 fourth valve

Claims

[1] Method for reducing the pathogenicity of pathogens, in particular parasitic molecules, which are contained in ambient air, in which ambient air containing pathogens is sucked in from the environment on the suction side by means of a compressor (1) and compressed to a pressure of at least 250 kPa and then the air, which has been reduced in its pathogenicity and is reduced again to the ambient pressure, is released into the environment, wherein the ambient air containing pathogens is passed through a heat exchanger (2) by means of the compressor (1) and heated with a heat pump and the compressed air is kept at a pressure of at least 250 kPa and at a temperature of at least 80 °C and a maximum of 150 °C with a residence time of at least 50 s and is then released again flowing through the heat exchanger (2) to the environment. [2] Method according to claim 1, characterized bythat the pathogen-containing ambient air, after flowing through the heat exchanger (2), is led through a condenser-heat exchanger unit (3) to the compressor (1) and from there via at least one line (4) into the heat exchanger (2), in which the pathogen-containing ambient air sucked in from the environment has been preheated before entering the condenser-heat exchanger unit (3) and the ambient air returned to the environment, reduced in its pathogenicity, is cooled, wherein refrigerant in the heat pump is supplied to a condenser-heat exchanger unit (3) by means of a refrigerant compressor (5) and in the condenser-heat exchanger unit (3) the refrigerant is partially condensed and releases heat to the sucked in pathogen-containing ambient air, wherein the partially condensed refrigerant is fed to a condenser (7) via a line and from the condenser (7) via an expansion valve (8) and a second valve (9) either returned in the circuit directly via an evaporator (10) to the refrigerant compressor (5) or by means of the second valve (9) via an evaporator heat exchanger unit (15) during the return to the refrigerant compressor (5) to the refrigerant evaporator (10) and thus in the circuit, whereby in the line (4) and / or at least one chamber (12.1, 12.2, 12.3) connected to the line (4), the ambient air heated to a maximum temperature of 150 °C is held with a residence time over a period of at least 50 s before being fed to the heat exchanger (2). [3] Method according to one of the preceding claims, characterized bythat in the line (4) and / or at least one chamber (12.1, 12.2, 12.3) connected to the line (4), the ambient air heated to a temperature of at least 80 °C and at most 150 °C is held for a period of at least 60 s, preferably at least 120 s and particularly preferably at least 180 s, before it is fed to the heat exchanger (2). [4] Method according to one of the preceding claims, characterized by that refrigerant for regulating the temperature of the ambient air in the line (4) and / or in the at least one chamber (12.1, 12.2, 12.3) is supplied via a first valve (6) of the condenser heat exchanger unit (3) or directly to the condenser (7) for the refrigerant. [5] Method according to one of the preceding claims, characterized bythat in the connecting line via which the refrigerant is led from the second valve (9) to a first evaporator-heat exchanger unit (15), and a third valve (13) is integrated in such a way that refrigerant and ambient air sucked in from the environment are fed to a second evaporator-heat exchanger unit (14) and subsequently in the direction of flow the refrigerant is fed to the evaporator (10) and the ambient air to the heat exchanger (2). [6] Method according to one of the preceding claims, characterized by that the residence time is influenced by means of the power with which the compressor (1) is operated for ambient air, the internal volume of the line (4) between the air compressor (1) and the heat exchanger (2) or the line (4) and the at least one chamber (12.1, 12.2, 12.3). [7] Method according to one of the preceding claims, characterized bythat the heat pump is operated intermittently and / or the heating of the ambient air is not carried out continuously. [8] Method according to one of claims 1 to 6, characterized by that the procedure is carried out continuously. [9] Method according to one of the preceding claims, characterized by that the heated ambient air flowing with the compressor (1) through the line (4) is alternately fed to individual chambers (12.1, 12.2, 12.3) so that the minimum residence time of the ambient air heated to at least 80 °C is maintained. [10] Device for carrying out the method according to one of the preceding claims, characterized bythat the device for treating pathogen-containing ambient air is formed with at least one compressor (1) and a heat pump for heating the pathogen-containing ambient air, and the pathogen-containing ambient air is guided through the heat exchanger (2), and the compressed and heated ambient air flows in countercurrent to the pathogen-containing ambient air through the heat exchanger (2) before it is discharged into the ambient air, wherein at least in the case of an axial compressor, compressed air is held in a sufficiently long line or at least one chamber within the residence time before this air is expanded and released into the environment. [11] Device according to the preceding claim, characterized bythat the heating system for the ambient air is formed by the heat exchanger (2), the compressor (1), the line (4) and / or the line (4) and at least one chamber (12.1, 12.2, 12.3) and the heat pump is formed by the refrigerant compressor (5), the condenser-heat exchanger unit (3), the condenser (7), the expansion valve (8) and the evaporator (10), wherein the ambient air and the ambient air reduced in pathogenicity are guided in countercurrent through the heat exchanger (2) and the ambient air containing pathogens and the refrigerant are guided separately from one another through the condenser-heat exchanger unit (3 and 15). [12] Device according to the preceding claim, characterized bythat in the heat pump circuit there is an additional second evaporator heat exchanger unit (14) through which refrigerant flows and which can be controlled via a third valve (13), through which the ambient air containing pathogens flows directly from the environment into the heating unit. [13] Device according to one of the two preceding claims, characterized by that a first valve (6) is present in the heat pump circuit, with which refrigerant can be fed from the refrigerant compressor (5) to the condenser heat exchanger unit (3) and / or directly to the condenser (7).

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