IT202100018020A1 - Environment sanitizer - Google Patents

Description

Environment sanitizer

Description

The present invention relates to an air sanitizer, in particular for sanitizing closed environments (indoors) such as homes, offices, schools, shops, doctors' surgeries, pharmacies, etc.

In general, a sanitizer comprises an air suction pump from the environment, an air purification mechanism and an outlet duct, for the emission of purified air from the sanitizer and the simultaneous introduction into the closed environment .

In recent decades, the sanitization of the air in closed or indoor environments? become a topic of health interest.

Indeed, in our society? you spend up to 90% of your time indoors and the quality? of the air we breathe inside our homes, offices and schools becomes a factor of fundamental importance for health. The WHO estimates leave little room for objection: 4.3 million deaths a year worldwide are attributable to poor quality food. of the air we breathe inside confined spaces. WHO data declare indoor air up to 10 times more? polluted than outdoor (?Impact of indoor pollution on population health?. www.salute.gov.it).

The indoor pollutants more? potentially harmful to human health are radon, which? carcinogen, some Volatile Organic Compounds (VOC - Volatile Organic Compounds) and fine particulate matter, with an aerodynamic diameter between 0 and 2.5 ?m and 0 and 10 ?m, whose concentrations in the air are expressed in ?g/m<3 >, and are indicated as PM2.5 and PM10, respectively. The term VOC indicates all those organic compounds having a vapor pressure higher than? high of 0.13 kPa, equal to 0.97 mmHg. There are over 650 types of VOCs measurable in air and they belong to various chemical classes.

In indoor environments, VOCs can be released from various sources, including:

? some materials such as paints, glues, solvents, wooden products and fabrics;

? combustion processes such as tobacco smoke and cooking food;

? some body cleansing products such as cosmetics, deodorants and cleansers for the body and hair; ? household cleaning products, such as dishwashing and furniture cleaners.

Some VOCs, such as formaldehyde and benzene, can be highly toxic as they are carcinogenic above a certain concentration in the air, while others, such as mercaptans, although not toxic, have such a strong odor-producing power as to produce headaches, nausea and even vomiting, even in low concentrations. The PM2.5 and PM10 particles also include some potentially toxic biological contaminants for human health, such as pathogenic bacteria such as Legionella pneumophila or Escherichia coli, plant spores and moulds, as they are all biological particles with an aerodynamic diameter greater than 0.3 ?m.

Viruses also fall into PM2.5 and PM10. Even if in the isolated form they fall within the ultrafine nanometric fraction of the particulate (from 1 to 0.01 ?m) many of them, such as the cold virus and SARS-CoV-2, are present in the air in the form of droplets with aerodynamic diameter greater than 1 ?m and therefore compatible with the above particulate dimensions.

All these chemical, physical and biological species will be defined below for simplicity? as indoor contaminants.

In this context, the sanitation term will be? therefore used to indicate the removal of indoor contaminants up to the achievement of concentrations in the air (in ?g/m<3>) close to those present in an outdoor air free of pollution according to Legislative Decree 13 August 2010, n.155 " Implementation of directive 2008/50/EC relating to ambient air quality and cleaner air in Europe" published in the Official Gazette no. 216 of 15 September 2010 - Suppl. Ordinary no. 217.

Furthermore, with the term sanitation, in this context, we will also mean the capacity? of inertization of the major biological contaminants possibly retained on solid matrices, such as for example the mechanical filters to break down the particulate.

The reduction of contaminants and/or their inerting in indoor environments, ? necessary whenever their concentrations exceed the warning or alert levels defined for air pollutants. In these cases, sanitization has the function of preventing the onset of diseases associated with closed buildings (BRI - Building Related Illness. See, for example, the results of the European project EnVIE "European Coordination Action for Indoor Air Quality and Health Effects" which evaluated the effects of indoor air quality on the health of the European population), as human exposure to these agents present in high concentrations is drastically reduced.

If prolonged over time, this exposure can give rise to very serious acute or chronic pathologies, such as asthma, fever from humidifiers, allergic alveolitis and legionellosis, as well as the transmission of bacterial and viral infections. The reduction of the concentrations of the aforementioned indoor contaminants? also effective in reducing the onset of a sensitivity syndrome? Multiple Chemistry (MCS ? see for example Rossi S, Pitidis A. Multiple Chemical Sensitivity: Review of the State of the Art in Epidemiology, Diagnosis, and Future Perspectives. J Occup Environ Med. 2018;60(2):138-146) associated with the negative reactions of? the organism, which can? occur even at generally tolerable concentrations.

The consequences of indoor pollution not only have an impact on health, but also on an economic level. In fact, as reported in the ISTISAN reports (Istituto Superiore di Sanit? www.iss.it), the economic damage due to air pollution inside confined spaces? as high as the social one. The disease most frequently encountered? bronchial asthma, with a health impact of 160,000 cases per year in Italy alone and a direct cost of more? of 80 million euros.

To deal with the critical above, two main types of devices have been used up to now.

The first type includes sanitizers which use lamps emitting ultraviolet radiation (UV, in particular UV-C) and/or ozone (O3), such as for example the devices described in US patent No. 3,576,593 A and in the application for US patent No.

2013/0309140 A1.

These devices cannot be used to sanitize indoor environments where people or animals are present, as they are direct and prolonged exposure to some radiation that falls within the UV-C wavelength range, such as that of a wavelength equal to or less than 254 nm can induce skin cancer, damage the retina, and produce ozone in concentrations high enough to cause harm if inhaled. Even if only exposure to concentrations of O3 higher than 10 ppmv (10,000 ppbv) ? considered fatal, even exposure to values between 1 and 2 ppmv (equivalent to 1,000-2,000 ppbv) can? cause serious respiratory diseases.

As well illustrated in the US patent 6,893,610 B1, a 24h exposure to O3 ? tolerable for? man only below 100 ppbv, while in the workplace? prolonged exposure at levels of 50 ppbv or less is tolerated.

Given the possible repercussions on human health, this type of sanitizer can only be used in empty rooms and during the night. Also in this case, however, adequate protective measures must be taken to safeguard the health of the operators. This type of sanitizers? mainly used in healthcare facilities, as it allows effective inerting of biological contaminants also present in large environments, in a relatively short time (a few hours). They are not for? equally effective in eliminating VOCs and fine particles. In fact, O3 at concentrations higher than 100-200 ppbv (0.1-0.2 ppmv) can? already oxidize some unsaturated VOCs (olefins, including alkenes, and polyolefins such as monoterpenes) producing formaldehyde, and secondary organic ultrafine particulate matter (secondary organic aerosol). See for example Finlayson-Pitts B.J. and Pitts J.N. Jr (2000) Chemistry of the Upper and Lower Atmosphere, Theory, Experiments, and Applications, Academic Press, New York, 2000).

The use of O3 at high concentrations (1-2 ppmv) also damages many polymeric materials with double bonds, such as rubber and polyethylene. In addition to imposing a substantial air exchange after sanitization, the prolonged use of this sanitization technology can have significant additional costs in terms of damage to materials.

Therefore, these devices are not suitable for domestic use or in work environments, even accessible to the public.

The second type concerns domestic sanitizers such as the one described in US patent No. 6,053,968 A, which provides for the use of UV-C lamps in order to eliminate some VOCs and filters to remove particulate matter.

The capacity? The VOC removal rate of this type of sanitizer strongly depends on the wavelength of the UV-C radiation used. If you use UV-C lamps whose wavelengths extend between 320 and 200 nm, there is a partial generation of O3 by photolysis of molecular oxygen (O2), while if you use lamps with a length between 254 and 320 nm there is no production of O3. The use of UV-C lamps which give a partial production of O3 are more? effective in removing VOCs and bacteria, while those that do not produce O3 can be more? effective in removing biological contaminants.

However, a critical aspect deriving from the sole use of UV-C radiation in sanitizing indoor environments lies in the exposure time of the contaminants to UV-C radiation. If it ? too short, right? always sufficient to inertize the biological contaminants that may eventually pass through the filter. If instead the exposure time is lengthened by reducing the flow of air through the filter, the removal of the particulate matter? so low as to require parity? of volume to be sanitized purification times much more? long compared to sanitizers that use an O3 generator as the primary source to generate more oxidizing species? reactive, such as hydroxyl ions (OH radicals), which have a more oxidative power? high dell?O3 compared to the VOC and inertize much more? biological contaminants quickly.

Not only the OH radicals are able to oxidize, even if at different times, almost? all the VOCs present in indoor air but, above all, the concentrations required to oxidize them to CO2 are three orders of magnitude higher? (20 pptv = 0.02 ppbv) than needed using O3 alone (100-200 ppbv. See for example Finlayson-Pitts B.J. and Pitts J.N. Jr (2000) Chemistry of the Upper and Lower Atmosphere, Theory, Experiments, and Applications, Academic Press, New York, 2000, https://doi.org/10.1016/B978-0-12-257060-5.X5000-X). Another very useful characteristic of OH radicals, ? that their atmospheric half-life ? what? short which are consumed in a few minutes if the O3 source is switched off.

The pandemic caused by the SARS-CoV-2 virus has further widened the application spectrum of indoor sanitizers, as the elimination and inertisation, in domestic and work environments, of the vehicles that cause the transmission of the virus (droplets - of aerodynamic diameter between 1 and 2,000 ?m), could give a formidable contribution in reducing the transmissibility? of this virus, as well as all other similar viruses. Does this imply for? the creation of a sanitizer with technical specifications such as to effectively eliminate particles in this aerodynamic diameter range, and ? this is the objective achieved with the present invention.

The technical problem that ? at the basis of the present invention ? that of creating a sanitizer for domestic and work-type indoor environments capable of actively removing the main contaminants (VOC, PM2.5 and PM10, bacteria, molds and droplets with a high viral load) until reaching and maintaining the same levels present in free air of high quality? environment, without incurring the limitations and drawbacks mentioned with reference to known techniques.

This problem is solved by a sanitizer for indoor environments as specified below and as defined in the annexed claim 1.

Said sanitizer for indoor environments comprises a casing containing different sections (in turn comprising one or more devices) communicating with each other, which, acting in synergy with each other, contribute to overcoming the limitations of the various sanitizers subject to patents previous.

To understand the role and importance that the sequence of devices included in the sanitizer plays in the device object of the invention and the innovation that this solution represents from a conceptual point of view, the specific functions they perform in the sanitizer are illustrated below, the main characteristics and the general chemical-physical principles on which they are based.

The sanitizer? consisting of a first suction section comprising an aspirator, for example a delivery fan (consisting of a blower or a pump) which has the task of withdrawing the indoor air to be sanitized by introducing it into the subsequent sections of the sanitizer, from which it is expelled placing it back into the environment after having purified it from the various contaminants originally present in the indoor environment.

Such contaminants can be, among others:

? produced in the environment by indoor sources (cigarette smoke, bacteria associated with the presence of people, animals, plants, saliva droplets generated by sneezing or excited talking, mold and fungi generated by humidity condensation phenomena, substances released from furnishings and cleaning products, etc.);

? formats for chemical and physical transformations of contaminants produced by indoor sources;

? coming from outside by diffusion, especially if the indoor environment is in urban areas and/or areas with a high emission of chemical contaminants from intense vehicular traffic and/or industrial emissions.

Immediately downstream of the aspirator ? the second filtration section was placed for the abatement of indoor contaminants consisting of a passive filtration system for some VOCs and fine particles. It includes a series of layers of progressive abatement consisting of:

i) an impactor for coarse particles with an aerodynamic diameter greater than 10 µm, which operates in complementary or alternative synergy with a metal sponge covered with TiO2, for the selective removal of formaldehyde and part of PM10.

ii) a permeable activated carbon filter covered with cotton wool, for the partial removal of PM2.5, PM10 and some high-boiling VOCs (such as oils, plasticizers, resins, biomass, metals, etc.). iii) a diffusion filter (also called denuder) that can? be ceramic-based covered with a layer of activated carbon, but also of other types, for the removal of some VOCs.

After the passive type filtration section, the air is introduced into the subsequent active type removal sections, which include a third section, called plasma section, comprising at least one plasma lamp, preferably corona discharge which produces low levels of O3, which chemically pre-treats the filtered airflow from the previous passive stage.

In the fourth section downstream of the plasma one, along the direction of the air flow, the sanitizer includes a double ultraviolet (UV) radiation subsection which is ? made up of two types of lamps at different wavelengths, the number of which can? be varied according to the type and radiant energy of the lamps used to generate the radiation.

The first type of lamp, in the first subsection, ? consisting of at least one UV-B lamp (which can be narrowband or broadband that borders on UV-A), preferably with a maximum centered around 311-312 nm, for a total value of about 19 W.

The second type of lamp, in the second subsection, ? consisting of at least one UV-C lamp, preferably of a number of UV-C lamps such as to obtain a variable power between 60 and 120 W, preferably with a wavelength range between 240 and 260 nm, even more ? preferably with a maximum at 254 nm.

Both types of lamps can be gas discharge or LED.

The internal walls of the fourth section containing the UV lamps can be covered with a TiO2 treated metal sponge or with a layer of TiO2 deposited directly on the internal metal surfaces.

The double section containing the UV-C and UV-B lamps? fully shielded so it doesn't affect people using the sanitizer.

The set of these lamps has the task of photolysing the O3 produced by the cold plasma lamp, converting it into OH and HO2 radicals (in particular with UV-C) but also of photolysing formaldehyde into CO (in particular with UV -B, see for example Finlayson-Pitts B.J. and Pitts J.N. Jr (2000) Chemistry of the Upper and Lower Atmosphere, Theory, Experiments, and Applications, Academic Press, New York, 2000). The UV-C also has the task of activating the TiO2 treated metal sponge, or the TiO2 deposited layer, to further remove formaldehyde and VOCs. In particular, the hydroperoxide radical HO2 ? quite reactive and acts as an air cleaner by degrading some organic pollutants.

The sanitizer comprises a fifth section, preferably placed in the casing laterally and transversally with respect to the first four passive and active sections and not communicating with these with respect to the air flow to be treated. In it ? installed a control unit comprising a hardware board with microprocessor equipped with a control firmware; a set of sensors are also connected to the hardware card, which can also be solid state, for the measurement of PM2.5, PM10, total VOC, formaldehyde, ozone, etc. The fifth section? equipped with an opening with a grill towards the outside and a fan that draws in the air from the indoor environment to be able to send it to the sensors; in this way the sensors measure the parameters of quality? of the indoor air to be treated.

Based on this measurement, the software ? capable of activating both the plasma lamps present in the system and the UV-C and UV-B ones in order to maximize the effect of removing contaminants, keeping the concentration of O3 in the indoor environment below 50 ppbv, and modulating suitably the concentrations of other oxidizing species such as OH and HO2 radicals in the air flow.

There? ? obtained as together with the lamps, the unit? control of the system also manages the flow of air that passes through the device, acting on the fan with the PWM technique ? Pulse-width modulation.

The main advantage of this device does not consist only in the fact that the air in an indoor environment can be sanitized in the presence of people, but that it is modulated according to the concentrations of contaminants present in the environment itself.

The various sections of the indoor contaminant abatement system are in fact activated automatically when the set of sensors present in the sanitizer register an increase in the levels of VOC or PM2.5 and PM10 or formaldehyde such as to exceed a safety threshold set in the management of the device, and manage the various stages of abatement until the levels measured by the set of sensors return within the safety levels.

Thanks to the synergy implemented between the different blast chilling sections, the device object of the present invention has an effective capacity air sanitization, quickly reducing the content of PM2.5 and PM10 and therefore of biological contaminants such as moulds, bacteria and viruses. Having been designed and validated to reduce fine particles with an aerodynamic diameter greater than or equal to 0.3 ?m, it ? able to quickly remove droplets of saliva containing viruses. The viruses they contain are progressively destroyed by the oxidative plasma which passes through the passive filtering layer.

As far as VOCs are concerned, the sanitizer efficiently exploits the process known as Advanced Oxidation Process, which consists in the progressive conversion of VOCs into CO and CO2 through their reactions with OH radicals and partially with O3 (See for example Finlayson-Pitts B.J. and Pitts J.N. Jr (2000) Chemistry of the Upper and Lower Atmosphere, Theory, Experiments, and Applications, Academic Press, New York, 2000).

By containing the maximum levels of O3 within 50 ppbv for less than an hour, said sanitizer generates a quantity of OH radicals sufficient for the removal of VOCs and biological contaminants, and by exploiting the synergies of the various compartments, it keeps the levels well within the tolerability? Human.

The formation of hydroxyl radicals (OH) in the active stage of the sanitizer occurs mainly through the photolysis of O3. Choosing a narrow band of wavelengths centered around 254 nm, isn't it? in fact random, as it corresponds to the radiation in which maximum ? the decomposition of O3 by photolysis. The photolytic decomposition of an O3 molecule leads to the formation of an O2 molecule and an excited singlet oxygen atom (powerful oxidant, the lowest of the excited states of molecular oxygen, indicated with <1>O2) which if irradiated by UV radiation with a wavelength lower than 310 nm, it reacts with a water molecule to form OH radicals. However, the photocatalysis of H2O on the metal sponge treated with TiO2, which is also activated by UV-C radiation, also contributes to the production of radicals.

Through the catalytic and photocatalytic production of OH radicals, the progressive oxidation of VOC is carried out up to CO and CO2 as final products, but also the inertization of biological contaminants both in the gaseous phase and in the adsorbed phase, in the case in which these contaminants are retained in the passive stage of the sanitizer.

The life time of the radical OH ? very short, but ? sufficient to exert its oxidizing power and promote chain reactions that produce other OH radicals.

Even if the main role of UV-C radiation is to produce OH radicals by photolyzing l? O3 generated by plasma lamps, the wavelength used (maximum around 254 nm) ? known to have a powerful germicidal action being also capable of destroying biological material, RNA, DNA, etc., both of bacteria and viruses. The main action of UV-B rays on a specific frequency, in synergy with passive filtering, is that of reducing any formaldehyde produced in the first stage of oxidation of some VOCs.

The presence of a lamp which generates an oxidative plasma in the air which passes through the sanitizer therefore plays a key role in the present invention. The original principle through which a plasma is generated? that of corona discharge in air. The application of a potential difference of a few kV between two electrodes separated by air induces an electric discharge similar to a small lightning bolt, which triggers a series of physical and chemical effects. The principal neutral product formed in the oxidative plasma produced by the discharge in air ? O3, which constitutes its main component, together with electrically charged oxygenated and nitrogenous molecules. The production of O3 in the presence of UV radiation and water also leads to a small formation of OH and HO2 radicals.

The use of air as a dielectric generates shock waves and electro-hydraulic cavitation, together with UV light emission.

? for this reason that in the present invention there is choice of another route, as illustrated below. Many of the physical and chemical effects can in fact be greatly attenuated and controlled if a material with a high dielectric constant is placed between the electrodes through which the discharge takes place, this is done with the DBD (Dielectric Barrier Discharge) lamps with barrier discharge dielectric. The difference between corona discharge in air and that which occurs through a material with a higher dielectric constant? remarkable, since in DBD lamps only the external part of the electrode produces an oxidizing plasma, being the other electrode immersed in the vacuum. There? made possible the construction of DBD lamps in which ? maximum production of oxidants in the plasma and the production of O3 can? be limited to certain pre-set levels. There? it is obtained by selecting the type of dielectric used, its thickness and the electric potential applied between the electrodes.

According to some preferred embodiments of the invention, the generation of plasma is carried out with particular DBD lamps suitably selected and very small (10 cm long and 2.5 cm wide) among which ? interposed a dielectric with a high dielectric constant in such a way as to limit the production of O3 by about three orders of magnitude compared to a corona discharge in air.

Although DBD type lamps are also used for sanitizing indoor environments, the levels of O3 they produce are still too high and can easily exceed 50 ppbv.

Furthermore, without the presence of a filter upstream, as indicated in the device object of the present invention, these lamps easily become contaminated, losing part of their effectiveness in generating the oxidative plasma. There? happens why? the particles in the air become electrically charged when they reach the electrode and some of them discharge onto the electrode itself, forming a film of material over time which is placed between the external electrode and the air.

According to some preferred embodiments of the present invention, the choice of the type of DBD lamps used for generating the plasma and their positioning downstream of the passive removal systems therefore plays a fundamental role for correct operation of the sanitiser. In fact, only a regular production of O3 allows effective control and safe modulation of the levels of O3 at the sanitizer outlet by means of UV-C radiation and photocatalysis on metal surfaces treated with suitable oxides. Therefore, the number and the dimensions of the lamps to be used for the generation of the plasma must be determined after an accurate measurement of the capacitance? of O3 production of the DBD lamps to be included in the system. In the sanitizer described in this patent, validated by a rigorous process both in the laboratory and in the real field, two very small lamps have been used, in order to modulate more? effectively the production of O3.

This invention will come described hereinafter according to a preferred embodiment thereof, provided by way of non-limiting example with reference to the attached drawings in which:

? figure 1 shows an isometric view of the sanitizer according to the invention;

? figure 2 shows another isometric view of the sanitizer according to the invention;

? Figure 3 shows a vertical sectional view of a schematic representation of the sanitizer according to the invention;

? figure 4 shows a schematic representation of the sanitizer according to the invention;

? figure 5 shows a block diagram of the method according to the invention;

In a first aspect, with reference to figures 1 to 4, the present invention refers to a sanitizer for environments which is indicated as a whole with 1.

The embodiment of said sanitizer 1 shown in the figures comprises an aspirator 10 which introduces, with pressure greater than atmospheric pressure, the air to be purified into the sanitizer 1, favoring the circulation of the air flow between the surrounding environment and the sanitizer 1; said sanitizer 1 also comprises a casing 25 containing five sections communicating with each other.

Following the direction of the air flow, the first section, called suction section 11, includes the aspirator 10, for example a centrifugal fan with a maximum flow rate of 720 m<3>/h which sucks in the air by introducing it into the sanitizer 1. The maximum range can? be increased in particular operating conditions and size of the indoor environment.

The second section, called filtration section 12, comprises three objects: an impactor 22 and/or a metal sponge, a first filter 7 with activated carbon surface treatment, in contact with a second hydrophilic filter 8.

Preferably, said impactor 22, which operates in complementary or alternative synergy with a metal sponge covered by TiO2, operates in a selective way for the removal of the formaldehyde and part of the PM 10. If the metal sponge is synergistic with the impactor 22, it will be? placed downstream of the impactor 22 itself. How described? a selective system for dimensional cutting of airborne particles, with the aim of removing the smallest particles? coarse and characterize the sampling of the air in relation to a certain dimensional cut.

Said filtration section 12 also makes it possible to create a homogeneous flow of air in the subsequent sections 13, 14, 15 of the sanitizer 1.

Said impactor 22 preferably comprises holes with a diameter of between 5 mm and 10 mm, in particular according to some embodiments they have a diameter of 8 mm.

Advantageously said diameter ? optimized to carry out an initial filtering of the particulate without excessively increasing the resistance to air transfer, ensuring a good compromise between filtering, sanitation times and energy consumption.

Advantageously, the filters 7, 8, unlike the carbon filters supported in polyurethane foam, are not subject to oxidative degradation, which implies the generation of further VOCs.

Said first filter 7 has, for example , an average pore diameter of between 0.3 mm and 0.6 mm.

Preferably, said second hydrophilic filter 8 ? made of cotton wool.

The addition of a cellulose-based cotton wool fabric downstream of the first filter 7 ? was made taking into account the different polarities? of the two adsorbent materials. Advantageously, given the greater presence in cellulose of molecules containing hydroxyl end groups (?OH), cotton ? able to better retain small and large molecules having polar groups (such as hydroxyl groups, -OH, or carboxyl groups, -COOH) capable of forming hydrogen bonds with the hydroxyl end groups of cellulose.

A layer of this material also allows you to retain sufficient quantities? of water on the filter 7 and to keep the?humidity? relative to the air, since? this parameter negatively affects the production of oxidants by at least one plasma lamp 2 included in the sanitizer 1. The presence of water in the cotton fiber also allows the strong acids (nitric and sulfuric) formed in the air to be retained in the filter during photochemical smog events, and the nucleation of ultrafine particles on the filter itself, allowing for better retention.

Still in section 12, downstream of filters 7 and 8 ? including at least one denuder 6, made of ceramic with a honeycomb structure covered with activated carbon.

The third section? the plasma section 13, comprising at least one plasma lamp 2.

Preferably said plasma lamp 2 ? of the type with dielectric barrier discharge (DBD).

Preferably, the sanitizer 1 comprises two plasma lamps 2. Said lamps 2 are suitable for the subsequent formation of OH, HO2 and O3 ions: all these chemical species participate in the oxidation and neutralization of VOCs, viruses and bacteria present in the air making it possible the circulation and purification of a maximum flow rate of 720 m<3>/h or greater.

Advantageously, according to the present embodiment of the invention, the sanitizer 1 comprises two plasma lamps 2 in order to be able to optimize the control of the production of hydroxyl ions and ozone. In fact, based on the concentrations of unwanted substances measured with a set of sensors 4 located in the sanitiser 1, including at least one O3 sensor, which measure the concentrations of substances present in the indoor environment, both lamps 2 are selectively activated or only one, in order to maximize the neutralizing effect in a small time interval and to cope with the initial pollutant peak. If during the operating phase of the sanitizer 1, the O3 sensor detects values higher than 50 ppbv, one of the two lamps 2 or both lamps 2 go out, so? to reduce the production of O3 as a by-product of the production of OH.

Advantageously, the second lamp 2 also goes out if a value of unwanted substances is detected which is now below an alert threshold, whereby ? enough the production of oxidants by a single plasma lamp 2 cos? to minimize energy consumption.

The fourth section downstream of the plasma one 13, according to the direction of the air flow, comprises two UV subsections, the first 14 equipped with at least one UV-B lamp 5a and the second 15 equipped with at least one UV-C lamp 5 The UV-B 5a UV-C 5 lamps can also consist of LEDs, respectively, UV-B and U-VC. The internal walls of the UV-C subsection 15 can be covered with a layer 5b of titanium dioxide TiO2 or possibly covered with a metal sponge covered with TiO2.

In order to guarantee the basic performance of the sanitizer 1 ? necessary to use a UV-C radiation which guarantees a combined effect on the bacterial and viral loads (as resulting from innumerable studies and experiments) and a bed of titanium dioxide as a catalyst, and a UV-B radiation which is specifically used for the abatement of formaldehyde. The two types of lamps 5, 5a are functional for the intended use, in the sense that while the UV-C 5 ? substantially always active, the UV-B 5a? active only when it is deemed necessary to further break down formaldehyde.

The activity control lamps 2, 5a, 5 ? carried out automatically thanks to a? unit? control system 17 comprising a CPU 3 and a software which presides over the operation of the sanitizer 1.

The fourth section? also the outlet section, comprising an outlet duct 16 of the sucked air in correspondence with which, on the casing 25, is reported a window 26 which allows the emission of sanitized air.

The fifth and final section 17a ? the section that houses the? unit? control 17 which presides over the modalities? operation of the sanitizer 1. Preferably ? a cross section, arranged vertically with respect to the other sections 11, 12, 13, 14, 15. In this section ? present a hardware card with microprocessor equipped with a control firmware; to the hardware card? also connected a set of sensors 4, also in solid state, for the measurement of particulate matter, VOC, formaldehyde, ozone. Section 17a ? equipped with an opening with a grill towards the outside with a fan that draws in the air from the environment to be able to send it to the set of sensors 4; in this way the sensors measure the parameters of quality? of the air by taking it directly from the indoor environment to be treated. On the basis of this measurement, the action of both the plasma lamps 2 and the UV lamps 5, 5a is adjusted in order to maximize their effect and/or to switch the individual devices on and off in such a way as to determine an O3 concentration in the indoor air below 50 ppbv and promoting the presence of oxidants such as OH and HO2 in the air stream.

Advantageously, said section 17a ? included in the sanitizer 1 in order to minimize the overall dimensions in line with the type of application envisaged for the sanitizer 1. In fact, the sanitizer 1 ? designed for use in an indoor environment, therefore it must meet compactness and design requirements.

Said casing 25, containing the sections described above, preferably has the shape of a parallelepiped 18 comprising a perforated side wall 19 at which the aspirator 10 operates and a perforated upper wall 20 at which the outlet duct 16 emits the air sucked by the aspirator 10.

According to other embodiments, the fenestration 26 for the outlet conduit 16 is located on one of the side walls.

According to some embodiments, the sanitizer 1 comprises a display 21 which functions as an interface for selecting pre-set operating programs.

The execution of these programs ? chaired by? unit? control 17 connected to the set of sensors 4, to the lamps 2, 5a, 5 and to the aspirator 10.

Said sanitizer 1, thanks to the presence of the unit? of control 17, ? suitable for carrying out an active and controlled sanitization of the air by aspirating and purifying it from organic and inorganic molecules, bacteria, molds and droplets containing viruses, thanks to the interaction with strongly oxidizing species, such as hydroxyl ions, but not toxic to living beings.

Advantageously said sanitizer 1 ? suitable for air purification with total PM2.5, PM10 and VOC levels of 2000-3000 ?g/m<3>

In particular, from the tests carried out in the laboratory yes ? found the ability to break down over 90% of total VOCs in about an hour. In particular, highly toxic compounds such as BTX (Benzene, Toluene, Xylene), methacrolein (MAC), methyl vinyl ketone (MVK) and methyl ethyl ketone (MEK) are quickly eliminated. At the same time the monoterpenes, methanethiol, isoprene and H2S are removed. While the first two belong to the category of strongly odorous and high-capacity substances. to produce O3, the last? both highly toxic and strongly odorous.

In the same time interval, the 50% reduction of acetonitrile, acetone and acetic acid was also detected. ? the removal of NO2 and formaldehyde was also detected.

Laboratory experiments have also highlighted that the sanitizer 1 prevents the birth and proliferation of molds within the treated environment. Furthermore, laboratory experiments have certified the reduction of the bacterial and viral load in the treated environment.

Laboratory measurements have highlighted how the removal of pollutants involves a reduction of more? of? 85% of the toxicity? measured through the use of the Microtox assay based on the use of bioluminescent bacteria Allivibrio fischeri (A. fischeri strain NRRL B?11177), never performed before to verify the removal of toxic substances in indoor abatement systems.

In a second aspect thereof, the present invention, with reference to figure 5, refers to a method of sanitizing the air indicated as a whole with 100, which uses a sanitizer 1 as previously described.

Said method 100 envisages entering the information relating to the environment to be sanitized via the display 21.

Once you have entered the necessary information, you can select one of the air purification programs proposed by the sanitizer 1.

Once a purification program has been started, the sanitizer 1 sucks in the air containing unwanted compounds, such as: VOCs, bacteria, viruses, etc. and filters it in the filtration section 12, blocking the compounds with larger dimensions or with greater polarity.

In the subsequent plasma section 13, through the unit? control 17 activates the at least one plasma lamp 2 which allows the generation of OH, HO2, O3 which combine with the unwanted compounds contained in the air. Excess O3 is dissociated into further highly oxidizing hydroxyl ions which react with undesirable compounds present in the air, neutralizing them.

In the operating phase, sensor set 4 monitors the O3 concentration: if the concentration ? greater than 50 ppbv for pi? of 60 minutes, at least one plasma lamp 2 contained in the plasma section 13 is switched off.

In the subsequent UV section 14, 15, the purification of the air from undesirable compounds which also includes the excess O3 is carried out by means of catalysis produced by at least one UV lamp 5, 5a.

Finally, through the outlet duct 16 the air is reintroduced into the surrounding environment free of unwanted compounds.

To the above described sanitizer for environments and the method for using said sanitizer, a technician in the field, in order to satisfy further and contingent needs, will be able to make numerous further modifications and variations, all however included in the scope of protection of the present invention, as defined by the attached claims.

Claims (16)

1. Sanitizer (1) for environments, including: ? a casing (25) containing a plurality? of sections communicating with each other; ? an aspirator (10) which introduces into the sanitizer (1) a flow of air to be sanitized under pressure, comprising unwanted substances; ? at least one DBD plasma lamp (2) contained in a plasma section (13) of said casing (25) which receives said air flow from said aspirator (10); ? at least one sensor for measuring the O3 contained in the air of the environment to be treated; ? at least one UV-B (5a) and UV-C (5) lamp arranged in a UV section downstream of the plasma section (13) in accordance with the direction of the air flow; ? a?unit? controller (17) comprising a CPU (3) and software which controls the operation of the at least one plasma lamp (2), of the at least one UV-B (5a) and UV-C lamp (5) and which receives a feedback from a set of sensors (4), in particular from the one for measuring O3 on the basis of which it turns on or off at least one plasma lamp (2) and at least one UV-B lamp (5a) and UV-C (5) in such a way as to determine an O3 concentration in the air leaving the sanitizer (1) lower than 50 ppbv, promoting the presence of oxidants such as OH and H2O2 in the air flow. 2. Sanitizer (1) for environments according to claim 1, comprising an impactor (22) placed downstream of the aspirator (10) in accordance with the direction of the air flow, for dimensional cutting of the airborne particles; said impactor (22) pu? operate in complementary or alternative synergy with a metal sponge covered with TiO2. 3. Sanitizer (1) for environments according to any one of the preceding claims, which comprises, downstream of the impactor (22), in accordance with the direction of the air flow, a first filter (7) in contact with a second filter ( 8) hydrophilic. 4. Room sanitizer (1) according to claim 3, wherein the second hydrophilic filter (8) is made of cotton wool. 5. Sanitizer (1) for environments according to any one of the preceding claims, which comprises, downstream of the first (7) and second filter (8) in accordance with the direction of the air flow, at least one ceramic denuder (6) with honeycomb and modular structure covered with activated carbon. 6. Sanitizer (1) for rooms according to claim 5, wherein said ceramic denuder (6) has a modular honeycomb structure with surfaces treated with activated carbon. 7. Sanitizer (1) for environments according to any one of the preceding claims, which comprises, downstream of the denuder (6) in accordance with the direction of the air flow, one or more? DBD plasma lamps (2) which allow the subsequent dissociation of O3 into electrically charged ionic compounds such as OH and HO2 radicals. 8. Sanitizer (1) for environments according to claim 7, wherein said catalyzing element (9) is a TiO2 coating partially activated by UV-B (5a) and UV-C (5) lamps. 9. Sanitizer (1) for environments according to any one of the preceding claims, wherein said aspirator (10) is a fan that can be of the tangential, centrifugal or axial type. 10. Sanitizer (1) for rooms according to claim 9, wherein said fan can have a flow rate between 300 and 720 m3/h or higher; according to the size, the speed? and therefore the flow can? be adjusted by the CPU (3) on the basis of the results of the quality? of the air detected by the set of sensors (4). 11. Sanitizer (1) for environments according to claim 1, comprising in succession, following the direction of the air flow: ? an aspiration section (11) comprising the aspirator (10); ? a filtration section (12) comprising an impactor (22), a first filter (7) in contact with a second hydrophilic filter (8); ? a plasma section (13), comprising at least one plasma lamp (2); ? a UV section comprising two subsections: UV-B (14) and UV-C (15), which in turn comprise at least one UV-B (5a) and/or UV-C (5) lamp; ? an outlet duct (16) for the aspirated air; ? a section dedicated to the control unit (17), arranged transversely vertically to the previous sections, to minimize the overall dimensions, also containing the set of sensors (4) for measuring the concentrations of the elements in the ambient air. 12. Sanitizer (1) for environments according to any preceding claim, comprising in the section dedicated to the unit of control (17) the set of sensors (4), also in solid state, from which the unit? controller (17) receives feedback relating to the concentration of unwanted substances in the air, on the basis of which it controls the operation of at least one plasma lamp (2) and at least one UV lamp (5, 5a). 13. Sanitizer (1) for environments according to any preceding claim, comprising a casing (25) in the shape of a parallelepiped (18) which has a perforated side wall (19) in correspondence with which the aspirator (10) operates, and a perforated upper wall (20) in correspondence with which the outlet duct (16) emits the air sucked in by the aspirator (10). 14. Sanitizer (1) for environments according to any one of the preceding claims comprising a display (21) which functions as an interface with said unit? control (17), for selecting the pre-set operating programs. 15. Method for sanitizing the air using a sanitizer (1) for rooms according to one of claims 1 to 14, characterized in that it comprises the following steps: ? enter the information relating to the environment to be sanitized via a display (21); ? select one of the air purification programs proposed by the sanitizer (1) which starts the following phases: ? suction of air containing indoor contaminants such as: VOCs, fine particles, bacteria, spores, fungi and viral droplets; ? filtering of the air in a filtration section (12), blocking the compounds with larger dimensions or with greater polarity; ? In a subsequent plasma section (13), through the unit? control (17) activates the at least one plasma lamp (2) which allows the generation of OH, HO2, O3 which combine with the unwanted compounds contained in the air; the O3 in excess is dissociated into further hydroxyl ions, highly oxidizing which react with the unwanted compounds present in the air, neutralizing them. ? measurement of the concentration of O3 with the set of sensors (4), also in solid state: if the concentration ? greater than 50 ppbv for pi? of 60 minutes, at least one plasma lamp (2) contained in the plasma section (13) is switched off; ? in a subsequent UV section, purification of the air from unwanted compounds which also includes the excess O3 by catalysis produced by at least one UV-C lamp (5) at a wavelength of 254 nm. ? measurement of the concentration of unwanted substances in which if the set of sensors (4), even in solid state, detect a concentration of unwanted substances, the plasma lamps (2), the UV lamps (5, 5a) and the value of the air flow; 16. Air sanitization method using a room sanitizer (1) according to one of claims 1 to 15, characterized in that it replaces the UV-B lamps (5a) and/or the UV-C lamps (5) or with LED lamps or with integrated plates of LEDs emitting radiation of the same wavelength as the lamps described.