WO2022113134A1 - Système de purification et de décontamination d'air microbiologique et procédé automatique de purification et de décontamination d'air microbiologique pour environnements confinés - Google Patents

Système de purification et de décontamination d'air microbiologique et procédé automatique de purification et de décontamination d'air microbiologique pour environnements confinés Download PDF

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Publication number
WO2022113134A1
WO2022113134A1 PCT/IT2021/050314 IT2021050314W WO2022113134A1 WO 2022113134 A1 WO2022113134 A1 WO 2022113134A1 IT 2021050314 W IT2021050314 W IT 2021050314W WO 2022113134 A1 WO2022113134 A1 WO 2022113134A1
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air
decontamination
plasma
purification
microbiological
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PCT/IT2021/050314
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English (en)
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Adriano SIVIERI
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Poloplasma S.R.L.
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Publication of WO2022113134A1 publication Critical patent/WO2022113134A1/fr

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F8/00—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying
    • F24F8/20—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying by sterilisation
    • F24F8/24—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying by sterilisation using sterilising media
    • F24F8/26—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying by sterilisation using sterilising media using ozone
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/0001—Control or safety arrangements for ventilation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/30—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/50—Control or safety arrangements characterised by user interfaces or communication
    • F24F11/52—Indication arrangements, e.g. displays
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/50—Control or safety arrangements characterised by user interfaces or communication
    • F24F11/56—Remote control
    • F24F11/57—Remote control using telephone networks
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/50—Control or safety arrangements characterised by user interfaces or communication
    • F24F11/56—Remote control
    • F24F11/58—Remote control using Internet communication
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/62—Control or safety arrangements characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
    • F24F11/63—Electronic processing
    • F24F11/64—Electronic processing using pre-stored data
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F3/00—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems
    • F24F3/12—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling
    • F24F3/16—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling by purification, e.g. by filtering; by sterilisation; by ozonisation
    • F24F3/167—Clean rooms, i.e. enclosed spaces in which a uniform flow of filtered air is distributed
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F7/00—Ventilation
    • F24F7/003—Ventilation in combination with air cleaning
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F7/00—Ventilation
    • F24F7/04—Ventilation with ducting systems, e.g. by double walls; with natural circulation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F8/00—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying
    • F24F8/10—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying by separation, e.g. by filtering
    • F24F8/192—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying by separation, e.g. by filtering by electrical means, e.g. by applying electrostatic fields or high voltages
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F8/00—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying
    • F24F8/30—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying by ionisation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F7/00—Ventilation
    • F24F2007/005—Cyclic ventilation, e.g. alternating air supply volume or reversing flow direction
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/0001—Control or safety arrangements for ventilation
    • F24F2011/0002—Control or safety arrangements for ventilation for admittance of outside air
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F2110/00—Control inputs relating to air properties
    • F24F2110/50—Air quality properties
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F2110/00—Control inputs relating to air properties
    • F24F2110/50—Air quality properties
    • F24F2110/65—Concentration of specific substances or contaminants
    • F24F2110/74—Ozone
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F8/00—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying
    • F24F8/10—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying by separation, e.g. by filtering
    • F24F8/108—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying by separation, e.g. by filtering using dry filter elements

Definitions

  • the present invention relates to an automatic system created for the decontamination of indoor air, dedicated to clean rooms and all indoor environments for civil use, in which a decontamination of pathogenic and non-pathogenic microorganisms is required, and a decrease in the particles in suspension with the objective to allow 24 hours a day, continuously : 1. the total elimination of the microbiological component suspended in the air and on surfaces;
  • the process referred to in the invention represented here was designed for classified environments, both ISO and non, which require purified and decontaminated air, and industrially declined according to the type of application. It was created to be installed in all indoor civil and industrial environments in which the use of always decontaminated and controlled air is required, such as, for example, those of the pharmaceutical industry in primis, food or cosmetics.
  • HVAC Heating Ventilation and Air Conditioning
  • UTA Air Handling Unit
  • the decontamination level defines the indoor air quality which, in turn, is defined by two main parameters summarized as follows:
  • microparticles which include microorganisms
  • ISO tables reduction of microparticles (which include microorganisms), according to ISO tables; the environments are then classified according to the number of particles detected.
  • Living microbes such as viruses, bacteria, spores, molds and fungi in order to move in the air need a support to which they can anchor and feed on, generally dust and water droplets in suspension.
  • the main source of biological pollutants is man himself with his metabolic activity, the scales of the skin, nose, throat, hands, clothes, hair, shoes, etc.; and the most effective way of contagion is made up of direct contact, and from humans the pathogens spread in the air and then settle on furniture, walls, floors, etc.; in addition, speaking, sneezing, coughing, exudation spread moist particles (droplets) containing infectious agents.
  • These are deposited or evaporated or remain in suspension in the air for a long time, forming the so-called nuclei of droplets which in the presence of humidity can condense water vapor and constitute microbial aerosols.
  • reference 10 designates the GMP (Good Manufacturing Practices) classes and the related corresponding ISOs
  • reference 20 designates the limit values of cfu for each class, using sedimentation plates for 4 hours that collect by gravity as much as exists suspended in the air; then for 7 days it will be counted how many and which colonies of microorganisms will grow.
  • the dilution of the environmental concentration of microbial agents depends more on the geometry of the intake and return of the air, on the measurement of the return air, and on the paths that the air makes in the room in question rather than on its quantity.
  • Ambient air filtration is used to keep the concentration of biological agents and particulates below the correct limits set by the purification class. While the introduction of external air serves to dilute and maintain the environmental concentrations of gas and other gaseous pollutants within the correct limits, even in the case of anomalous emissions.
  • the main purpose of ventilation is not only to ensure acceptable thermo-hygrometric conditions for users, a noble and important purpose, but also to ensure the absence of microbiological contaminants and to keep the environment within concentration limits, of the particles according to the class of environmental characteristics required, defined in degrees of cleanliness, from A to D (ISO 5 ⁇ 8).
  • filters of an adequate level retain most of the particles present in the air that passes through them and are classified according to the degree of filtration: with HEPA filters (High Efficiency Particulate Air filter) a particular high efficiency filtration system is indicated, of fluids (liquids or gases).
  • HEPA filters belong to the category of so-called “absolute filters", which also includes ULPA filters. More specifically, the H14 filters at the entrance to the environment are used to stop up to 99.995% any possible polluting particle in suspension and which can deposit on surfaces.
  • Air recirculation Air recirculation.
  • air recirculation does not mean that the external ventilation air is totally eliminated, but rather the number of changes/hour of a certain environment using the two airs (external-internal). On the outside, the task of replacement and dilution remains, while on the inside the task of contributing to the removal of microbial agents after filtering.
  • the dilution of the environmental concentration of microbial agents depends more on the geometry of the intake and return of the air, on the measurement of the return air, and on the paths that the air makes in the room in question rather than on its quantity.
  • Ambient air filtration serves to keep the concentration of biological agents and particulates below the correct limits set by the purification class.
  • the introduction of external air helps the dilution and maintenance within the correct limits of the environmental concentrations of gas and other gaseous pollutants, even in the case of anomalous emissions.
  • the introduction of external air serves above all to cope with the metabolic needs of the people present in the room, or to create an indoor air quality with high purity standards and maintain them over time regardless of the variation of internal polluting loads.
  • air recirculation does not mean that the external ventilation air is totally eliminated, but rather that the number of changes/hour of a certain environment is dosed using the two airs (external-internal). On the outside, the task of replacement and dilution remains in the percentage chosen according to the case, while on the inside the task of contributing to the removal of microbial agents after filtering.
  • HVAC Heating Ventilation Air Conditioning
  • AHU Air Handling Unit
  • the air is allowed to enter the environment from above after being filtered with absolute filters (HEPA) with reference 10, and is taken from below (references 20a and 20b). In this way the suspended particles are pushed towards the ground and sucked towards the HVAC.
  • HEPA absolute filters
  • an HVAC sized according to the environment to be decontaminated is installed, with reference (10), connected to the white room (80) chamber via delivery and (60) return (40) channels, using HEPA filters with reference (50).
  • the air enters from the outside from channel (30), passes through the medium filter F7/9 (70b) and is sent to the clean room by passing through the absolute filters in an adequate number for the environment (50); it is then taken up from below and filtered with coarse G4 filters to protect the heat recovery unit (70a). From this point, usually 75% of the volume returns to the environment (80) and
  • HVAC Heating Ventilation Air Conditioning
  • AHU Air
  • HVAC Heating Ventilation Air Conditioning
  • AHU Air Handling Unit
  • clean rooms are environments that control the number of suspended particles in the ambient air through filtration, and in which the staff work, who contaminate the same environment with their presence.
  • degrees of air purity required according to the type of processing they are associated with. They are found both in pharmaceuticals and in cosmetics, in medical research, but also in the food industry, meat processing, etc.
  • the limit of this classification method is the fact that it is concentrated on the number of suspended particles, both in “at rest” conditions, that is, in the absence of personnel, and “in operation”, with the internal personnel carrying out work in controlled environment. Since the particle measurements are performed once every 6 months, and the measurements of microbiological decontamination equally, if all goes well, it is obvious to think that it is difficult to guarantee compliance with the conditions detected on the day of the checks.
  • HEPA filters which are replaced when the pressure switches connected to them reach a predetermined value of filter arrest, or rather of wear, with the suspicion that in the meantime it will have already been abundantly contaminated by bacteria, viruses, molds and spores to varying degrees.
  • VMC Controlled Mechanical Ventilation
  • the object of this solution is to find an automatic decontamination process for controlled environments, such as clean rooms and environments for civil use, with the relative pipes and filters, through the control of the gas plasma of the air itself, produced by a set consisting of 1 or more cold plasma generators with SDBD technology, according to the needs of the environment to be decontaminated.
  • the generators produce a strong ionization of the air which is dynamically transformed into plasma, and the system uses as the main indicator of the process the controlled quantity of Ozone present during the decontamination cycle, which is necessary for the decontamination of bacteria, viruses, molds, fungi. and different types of spores.
  • the flow, recycling and subsequent exchange of indoor air is controlled by an HVAC system during the entire process. In this way, a safe and repeatable decontamination will be obtained over time.
  • the main application of the present invention are clean rooms used above all in the pharmaceutical, hospital, electronic and more generally in all applications in which the materials handled require a purified and decontaminated environment in order not to pollute them.
  • the goal is a 24-hour continuous decontamination cycle of the environment, implemented through different degrees of plasma gas diluted in the air circulating in the system, at room temperature. Dry air plasma gas, at ambient temperature.
  • ROS reactive oxygen species
  • the essence of the project and the heart of the system is the SDBD (Surface Dielectric Barrier Discharge) cold plasma reactor, created with studies for aeronautical fluid dynamics, but used here above all for the shape suitable for the flow of air, for the resistance to high speeds of the itself, and for the modularity and scalability of the system.
  • the cold plasma generated is a type of plasma of the air itself, that is, a collection of positive, negative and electron ions in an overall neutral gas, characterized by a high density of electrons and a low energy of the same.
  • the gas turns into plasma when it is in an environment subjected to a high electric field.
  • the plasma gas that is generated at atmospheric pressure is nothing more than an electrostatic discharge that has particular characteristics.
  • the genesis of the discharges referred to in reference 50a and 50b is induced by a system composed of a glass-ceramic dielectric with reference 10, two aluminum electrodes with reference 20a and 20b, and is induced by an electric field with reference 60a and 60b, of sufficient intensity to ionize the gas, in this case air with reference 40 flowing into the channels via the HVAC.
  • the high electric field with alternating power supply accelerates the electrons that collide with the molecules and which, due to their mass, are practically stationary with respect to the electrons, and give them a rather high energy.
  • the most important reactions for the system are those related to Ozone because they are more easily detectable by sensors on the market, and allow a fine adjustment of the action and dilution of the plasma, with consequent good control of the ionization process of the air and the related decontamination cycle.
  • the solution described herein provides for the generation of air plasma at room temperature and dry, ie without the production or addition of disinfectants or steam.
  • Plasma decontamination is due to the generation of a mix of oxidizing products such as ozone, and other oxygen derivatives (more particularly ROS), and the small amount of H202 contained in the residual humidity of the air.
  • ROS oxygen derivatives
  • amino acids most sensitive to the action of free radicals are proline, histidine, those containing thiol groups (cysteine and methionine) and aromatic groups (phenylalanine, tyrosine, tryptophan) (Menzel et al., 1971).
  • the spores are characterized by a high resistance to disinfectant agents, and can be understood as two different living products: in the kingdom of plants and fungi, these are reproductive cells which, by germinating, produce a new individual. But among bacteria, on the other hand, it is a vital phase that serves for extreme survival. In both cases they are able to disperse in the environment to resist adverse conditions and, subsequently, generate (or regenerate) a viable individual, in habitats more or less suitable for their living conditions (optimal temperature, presence of water and nitrient substances).
  • Plasma-induced reduction of microparticles in addition to microbiological decontamination, there is also a second mechanism induced by plasma, namely the aggregation of micro- dust molecules and suspended spores, which grow larger and become macromolecules, which fall to the ground by gravity.
  • this characteristic was tested for 8 months in a large environment used as a clean room, operating 8 hours a day, classified IS08 and with reference (30) defined by a range of 352.00 ⁇ 3.520.000 particles with a diameter equal to or greater than 0.5 pm referred to in reference (20), therefore very light and suspended in the ambient air.
  • the chamber with an environmental volume of 386 m is equipped with very powerful HVAC with a flow rate of 21,000 m 3 /h of supply air, of which 16,000 from recirculation and 5,000 from outside air.
  • the measurements, carried out by an external qualified person, and in 3 different points with different processes referred to in reference (10), with PMS Lasair 300 particle counter equipment, show that before the use of the system in the air there were from 1,600,000 to 1,800.000 particles of 0.5 pm, while after 7 days of use of the gas plasma system, the same particles have been reduced to 857,000 on average, referred to in the reference (40), with an average reduction of 50%.
  • This mechanism is valid for any confined environment whose number of suspended particles is to be controlled for the ISO classification .
  • Ozone was chosen as the main indicator for the control of the decontamination process; because, despite being very unstable in itself, it instead has a rather stable conversion process into oxygen. In fact at room temperature between 20 and 30 degrees centigrade, the ozone decays and turns back into molecular oxygen with a constant half-life. Measured in PPM (Parts Per Million), or in PPB (Parts per Billion) according to the type of application (in the case of a ppb clean room), the amount of
  • Ozone present in the air is halved in a time that can be constantly detected between 8 and 10 minutes. Furthermore, ozone control is more easily detectable with sensors currently on the market. These characteristics have allowed us to develop plasma generators that could support a certain amount of Ozone over time, able to replace the progressive decay after the first 10 minutes of work, with the necessary quantity of plasma suitable for maintaining a certain value, of Ozone suitable for decontamination and air purification.
  • the table represents on the left (10), the 6 positions of the plates with the dates before and after the plasma, with the reference (20) the results before the plasma and with (30) after the plasma for 7 days. With the reference (40) the limit for an ISO 8 clean room. With the reference (50) we see the average of the cfu before and after, with an average of lufc/4h (decrease of
  • the air will be taken from the environment, constantly measured by the sensors, which measure 02, 03, N02, temperature, humidity, flow rate, VOC (IDA), flow rate in m3/h, while the PM ⁇ 0.5pm, from 1, 5pm, 5pm and 10 pm are measured in situ with only dedicated equipment such as particle counters, to validate the type of process implemented.
  • the control unit will automatically control both the external and internal air opening and closing shutters, in order to reuse the air by checking the parameters set, and letting it enter again according to the settings.
  • the plasma control values will be used to maintain the reference Ozone value around a range of 40 ⁇ 50 ppb.
  • the plasma function will be increased to generate higher Ozone levels, from 300ppb to lppm and beyond up to lOppm, the maximum control limit of the sensor, for several hours according to the volume to be treated, and a simultaneous certain amount of nitrogen dioxide (N02).
  • N02 nitrogen dioxide
  • the combination of the two gases plus the hydrogen peroxide (H202) in small quantities due to the humidity of the air, will serve to reinforce the decontaminated action: the exchange of air volumes will be determined experimentally using both the air flow of the general HVAC system (when already installed) in combination with the internal HVAC of the system, the continuous measurements of the internal sensors.
  • the Ozone value will be lowered back to the basic one, within a constant range of 40 ⁇ 50 ppb/h.
  • the Ozone trend programmed from 12.00 the day before, until 06.30 the next morning.
  • the constantly monitored parameters while below we can see the date, time and the relative value measured and stored in memory.
  • the diagram represented with reference (20) represents the ozone trend from 12 to 6.30 the following day.
  • the sinusoidal shape is given by the inertia due to the delayed reading depending on the volume of the environment and the mix of air that is blown, so it must always be considered an average value.
  • the reference (50) indicates the type of impulse that is given to obtain the desired average value and for example 25/100 - 1516 means a primary impulse with 25 Ton and 100 Toff and limits 150/160 to obtain an average value of 150 ppb and so on up to 40/100-1718 to obtain an average value of 225 ppb/h.
  • the hardware and software system has been set and adapted to manage the air flow so that it can be recycled at 100% “at rest” and then automatically expelled at 25-30% and recycled 70-75% "in operation” at the end of the cycle; once the necessary mix has been identified, the plasma generators automatically manage the necessary amount of ozone during the process of rising, maintaining and decaying with the transformation into air.
  • the invention consists of five distinct modules:
  • HVAC module with internal piping referred to in reference
  • Control module 90 containing commands and controls from PLC, graphic interface, Internet connection, power supply (100) and plasma generators (110).
  • a monitoring device including a mobile radio terminal (for example: a mobile phone, a tablet or a PC) designed for remote process management
  • a server to acquire data from sensors through a data acquisition platform i.e. a data archive server (for example a hard disk or SSD), i.e. a local storage and archiving system
  • a data acquisition platform i.e. a data archive server (for example a hard disk or SSD), i.e. a local storage and archiving system
  • a data transmission module via GPRS or UMTS or later preferably with TCP/IP network protocol
  • a telemetry gateway for example the A850 Telemetry
  • HVAC module (10) suitable for processing data by means of a wireless technology on a public network (for example 3G/4G/5G, or later) or private (public or private hot-spots, e.g. Wi-Fi or Li-Fi).
  • HVAC module (10) suitable for processing data by means of a wireless technology on a public network (for example 3G/4G/5G, or later) or private (public or private hot-spots, e.g. Wi-Fi or Li-Fi).
  • HVAC Air Handling Unit
  • the HVAC is used to circulate the air within the environment to be decontaminated and purified (with reference 120), to set the desired flow rate and the speed of the air itself.
  • the flow rate must be around 250 m 3 /h, equivalent to 0.60 air recirculations per minute, obtained with an inlet channel with the reference (40), with a diameter of 160. mm and at the outlet with the channel (50), with 0 160 mm, in order to recycle the cold plasma up to a maximum of 100% within the volume to be purified.
  • the HVAC air handling unit in Figure 1, communicates with a 0160 mm supply air inlet duct or duct, indicated with the reference (20), which intercepts air from outside or from the HVAC ducts (if existing), and with an exhaust air duct to the outside or into the HVAC duct, and indicated with the reference (30). These channels have a maximum flow rate of 300 - 600 m 3 /h.
  • the flow of air arriving from the outside enters through the supply air inlet channel with the reference (20) and reaches the HVAC with the reference (10); between the duct/duct (20) and the HVAC unit (10) there is a butterfly valve/damper with the reference Ml which allows you to "dose" the inlet air flow.
  • Ml damper when the Ml damper is closed, the air coming from the supply air inlet duct (20) does not enter the air handling unit (10). Then it passes through the heat recovery unit (16) attracted by the fan (14), and through the discharge boards of the plasma generator; subsequently the flow rate is measured through a flow switch (60) and enters the environment to be purified (120).
  • a butterfly valve / damper M2 is interposed between the air handling unit (10) and the duct (30) which allows you to "dose" the outgoing air flow.
  • the exhausted air coming from the air handling unit (10) cannot enter the air expulsion channel (30).
  • Downstream of the valve or damper Ml i.e. in the portion of the duct between the damper Ml and the air handling unit (10) it is possible to provide a diverter module indicated with PL1, while upstream of the valve/damper M2 (i.e.
  • the diverter modules PL1 and PL2 are modules with one input and a plurality of outputs designed to receive and distribute the air in different directions These modules allow to increase the flexibility of the system by being able to redirect the air in different directions in the eventuality to serve different contiguous environments, and being able to achieve a pressure control.
  • the HVAC air handling unit (10) includes two fans with references (12) and (14), one for supply/intake of air (indicated with reference 12) and the other for intake and exhaust exhaust air (indicated with reference 14). More specifically, the fan (12) is called the suction fan, which draws air from the outside, conveys it to the supply air inlet channel (20) and sends it inside the HVAC air handling unit (10).
  • the second fan (14) is an emission fan that draws air from inside the HVAC air handling unit (10) and sends it to the outside through the expulsion channel (30).
  • the HVAC air handling unit (10) can also include a heat recovery module (16).
  • This module (16) allows the exchange of heat between the inlet and expulsion air flows to recover heat and reduce the temperature difference between the two flows.
  • the heat recovery unit (16) is a hexagonal solid of synthetic material, drilled in a honeycomb, in which separate flows flow the supply and output air, of which a flow transfers the heat energy to the other, from the hottest to the coldest gas, in accordance with the second law of thermodynamics. In this way, the temperature of the incoming air will be very similar to that outgoing from the environment, whether it is warmer or cooled.
  • the HVAC air handling unit (10) can comprise two mechanical air purification filters: the first, with the reference (16a) is placed at the inlet of the recuperator (16) and one, with the reference (16b), leaving the recuperator (16). These filters (16a) and (16b) are used to stop all the particles contained in the air, down to smaller and smaller sizes, according to a precise classification governed by the EN779 standards, giving the air a first mechanical filtration, subsequently increased also from any recirculation.
  • a high efficiency filter 16a in class F7 or F9 is usually placed at the inlet, which stops substances up to the size of 0.4 pm.
  • This filter (16a) also has a second function, namely that of preserving the heat exchanger (16) from any dust, which would greatly limit its efficiency over time; in this regard, dynamic pressure switches are connected to the filters (16a) and (16b) which indicate when the filters are clogged and need to be replaced.
  • the outlet filter (16b) of the G4 type, slightly coarser, which protects the heat recovery unit (16) from any micro-dust contained in the outgoing internal air.
  • the HVAC air handling unit (10) is in communication with two further channels with references (40) and (50).
  • the channel (40) is the air delivery channel in the controlled environment with the reference (120), either directly or through the existing HVAC channel, while the channel (50) is the room air intake channel (120 ) or through the existing HVAC recovery channel.
  • the return air that enters the channel (50) is sent back to the HVAC (10) through the channel (25).
  • the ducts (20), (30), (40) and (50) for transporting the air that enter and exit the HVAC unit (10) are equipped with electrically controlled dampers indicated in the figure with the references Ml, M2, and M3.
  • dampers allow to open completely, close completely or regulate the passage of the air flow in the air transport ducts (20), (30), (40) and (50) and have different possible positions: valve in position 90° indicates open valve and maximum air passage, 0° damper indicates the valve completely closed and the absence of air passage, while a different indication, for example 45° indicates an intermediate position of the valve, with a flow of 50% controlled air.
  • the damper indicated by Ml controls the amount of external air required, or its opening and/or closing allows more or less air to reach the air handling unit (10).
  • the damper indicated with M2 controls the amount of air expelled from the air handling unit (10). 100% air recirculation
  • the air For the construction of the purification cycle it is essential that the air can be recirculated at 100% throughout the decontamination cycle, and it is vital that the action of the shutters is coordinated; to create 100% complete air recirculation, the shutters must be positioned as follows:
  • the system described here comprises a sensor module (70) of Figure 1, containing the various sensors for detecting the main parameters of the air.
  • the sensor module (70) is placed at the first air intake from the environment to be decontaminated with reference (120), through the channel with reference (50).
  • the sensor board is placed before the filter (16b) and the M3 damper and the duct (25); in this way the return air will be continuously checked regardless of how it is used.
  • the sensors detect the set values every 30 seconds, and supply the data to the control unit in Figure 1 with reference (100), which stores all the data in local memory for up to a week and then loses them or stores them in the cloud.
  • the data is displayed in various forms on the monitor inserted in the control system, or directly on any PC connected via the Internet to the system itself.
  • the data can also be downloaded in XLM format (Microsoft Excel) and reconstructed and analyzed as needed.
  • XLM format Microsoft Excel
  • the architecture of the high voltage generators has been designed to be modular, in order to comply with various possible application needs and for safety reasons.
  • the plasma generators are composed of 1 or more separate modules, with separate power supplies and connected to 1 or more sets of 6 or more SDBD discharge cards separated from each other with reference (80) in figure 1.
  • the generators are positioned in Figure 1 with reference (110), inside the control module (90), and connected to the boards (80) by means of cables of predetermined length since the whole generation system works with precise resonant frequencies.
  • the generated signal is sinusoidal, in high voltage at 3.5 KV and frequency 30KHz, of which the power supply is 12 Volts, the current draw is around 10 Amps, and a power of about 120 Watts each.
  • the packet sinusoidal pulse method for plasma generation In order to obtain the control of discharges and therefore the relative control of indicators such as Ozone and NO2, it was necessary to modulate the amount of discharges over time and to dose the amount of energy useful for the predetermined result.
  • the sequence of high voltage and frequency pulses can be modulated in packets or "bursts" defined in a "Duty Cycle", which is defined Ton with the reference (10) the time in which for a certain number of msec is transmitted, and subsequently a Toff with reference (20), in which the generator is switched off.
  • the discharge modules that generate the plasma are composed of 1 or more sets, each of which has 6 or more boards arranged in a comb and in line with the air flow exiting the HVAC module, so that the air passes between the elements generating the electrical micro-discharges.
  • the boards are positioned downstream of the fan with reference (14), of delivery, before the channel (40) entering the room (120).
  • each element of the set is composed of a ceramic glass card with reference (10), 140 mm long and 100 mm wide; each side of the card is covered with an aluminum tape with reference 20 and 30.
  • the tape is 0.2mm thick and 40mm high.
  • the choice of aluminum is due to its conductive properties but also to the fact that it is non magnetic.
  • the discharges, with reference (40), according to the pulse pattern will be intermittent to continuous, a few millimeters high and blue in color.
  • a pulsed sinusoidal voltage was used; also an innovative concept, already validated both in theoretical simulations of the chemical kinetics of plasma and in prototype testing.
  • command module (90) controls all parts of the system:
  • the two high voltage generation modules necessary for the production of cold plasma with reference (110), 6.
  • the two sets of discharge boards necessary for the generation of the plasma with reference (80) 7.
  • PLC Programmable Logic Controller
  • the touch screen monitor (130) When the whole system is on, it communicates through the touch screen monitor (130) in figure 1 and as described in the image in Figure 20, in which we can see on the left the scheme of the system and the state of the dampers with reference (10), the state of the primary and secondary Ton and Toff, the plasma status if on or off with reference (20), and on the right 5 columns with reference (30), of which the first on the left indicates the real-time status of the controlled gas values, and the following the minimum, maximum and alarm values set.
  • the plasma is turned on when it falls below the minimum level, and is turned off when the maximum level is exceeded, in order to keep the values within a set range. If the alarm level was exceeded, all the shutters would be opened and external air would be allowed to enter in the maximum capacity of 330 m3/h, which would immediately cool the environment.
  • Figure 24 relates to the presets with the daily and/or weekly programming times, and with the reference (10) the hours of the day are indicated, and of which the type of preset can be chosen for each hour; pressing the button (20) the preset menu will appear and you can choose one.
  • the two main configura ions are the two main configura ions .
  • the proposed decontamination system must be adaptable to the environment in which it is installed, since it is presumed that the existing clean rooms have their own HVAC system already in operation and the proposed system has the task of improving the existing performance, with one study of the characteristics before installation, with an adaptation of the functionalities to the intended purpose, and a verification and testing relating to the purification and decontamination performance after installation.
  • the system can be declined in two solutions, depending on whether or not there is already a controlled ventilation with HVAC: 1.
  • the installation will take place by flanking the cold plasma system with reference (80), in which a portion of the air will be taken from the main return duct (40) through the channel (70); the air will pass through the sensors that will analyze all the parameters already described above, and the percentage in ppb of the ozone present in the environment will be used as a reference; the air will be forced through the cold plasma generators (110) experimentally adjusted for the purpose, and reintroduced through the channel (100).
  • the two channels (130) for the intake of external air, and (120) for the expulsion, will be used in the event of an alarm by letting in fresh air at maximum capacity, or in the absence of CO2 sensors in the existing HVAC system, when the C02 for various reasons was too high. System without internal HVAC.
  • the external air is drawn in through the channel (40) of the HVAC (30), with a percentage of 25% of the total flow enters and mixes with that of 75% of recirculation ( 60) coming from the environment, passes first through the F9 filters (90), then through the sensor module (20), and lastly into the cold plasma discharge module (30) also described in Figure 3D 26, and enters the environment. It is then taken up by the channel (70), 25% expelled from the channel (50) and
  • the purification and decontamination process involves the following implementation time schedule, with the aim of creating the standard curve of the chosen indicator, referred to in Figure (14), namely Ozone; for example, for an environment with volume of 400m3 and 21,000 m3/h, the presets "in operation” will be set with personnel inside with a Ton 12msec and 100msec Toff and minimum limits 40ppb and maximum 50ppb, from 7.00 to 19.00, and we will keep the concentration of Ozone within the legal and safety limits; while "at rest” that is from 19.00 to 23.00 at night we can choose a decontamination preset around 170-200ppb, and then go up to 600ppb for two hours with Ton 50msec and Toff 100msec, minimum limit 580ppb and maximum 600ppb and 700 ppb alarm.
  • Ton 50msec and Toff 100msec, minimum limit 580ppb and maximum 600ppb and 700 ppb alarm We will obtain a diagram similar to the one in the figure in which during the day we will have very low values of Ozone but
  • the first operation is the preset of the data shown in figure 23.
  • the first operation is the preset of the data shown in figure 23.
  • the preset of the data shown in figure 23 is the preset of the data shown in figure 23.
  • the primary HVAC will have to be reprogrammed to decrease the total volume to the minimum possible “at rest”, so that the plasma concentration is higher in order to increase the effectiveness of the decontamination. While “in operation” it will return to the total programmed volume.
  • the results obtained will be checked with the particle counter to determine the ISO classification. It is known that clean rooms are usually oversized in order to better stay within the desired classification.
  • the total volume of air will be decreased because it will be possible to accurately determine the purification and decontamination process. For example, if the results were closer to the minimum than that ISO class, the total volumes of air needed could be reduced while remaining within the limits of the same, thus reducing the energy used for the same purpose.
  • the proposed system since it is a new design and first installation, the proposed system does not include internal HVAC and will only use the main one, which will be adjusted according to the results due to cold plasma and day and night cycles or fast decontamination.
  • the process will include the same decontamination cycle described above, in which the goal of creating the standard curve of the chosen indicator, referred to in Figure (14), namely Ozone.
  • the plasma "in operation” will be activated such as to have an Ozone concentration of 40 ⁇ 50 ppb and at night or "at rest” at different levels up to at about 600 ppb for at least two hours.
  • the HVAC will be adjusted as follows:
  • the HVAC will have to be regulated with 100% recirculation, and the total volume decreased to 800 m3/h, so that the plasma gas can stagnate, exchanging the air due times an hour and can better decontaminate the environment and filters.
  • the control system (70) will include the PLCs, power supplies and Internet connection, the sensor module (30) and the two sets of plasma discharge boards (40); while the two reference plasma generators (60) will be external and close to the plenum.
  • the pipes will have a diameter in a range of 200 ⁇ 300 mm reference (50), and the plenum that will contain the sensor module (30) and the two sets of discharge boards (40) will have dimensions 400x400 mm (reference 10) x 1300 mm long (ref 20.
  • the HVAC HVAC
  • the innovation .
  • SDBD Surface Dielectric Barrier Discharge
  • HVAC it is related only to the exchange of air, and at most, but not always, to the C02 value present in the environments, to increase the quantity of air coming from outside to dilute its concentration.
  • the innovation in this case lies in the fact of being able to consistently reduce the bacterial load present in the environments during the day (in operation), and being able to decontaminate during the night or in the absence of personnel (at rest).

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Human Computer Interaction (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • Fuzzy Systems (AREA)
  • Mathematical Physics (AREA)
  • Disinfection, Sterilisation Or Deodorisation Of Air (AREA)
  • Apparatus For Disinfection Or Sterilisation (AREA)

Abstract

L'invention concerne un procédé automatique de purification et de décontamination microbiologique d'environnements confinés, dans lesquels la purification et la décontamination microbiologique est obtenue par une technologie de gaz plasma froid de l'air à température ambiante. Le système de purification et de décontamination d'air microbiologique pour espaces confinés est constitué d'un système de CVC qui génère un flux d'air qui est amené à s'écouler dans 1 ou plusieurs ensembles de cartes à décharge électrique, avec une géométrie plane SDBD, et remis en circulation avec un processus automatique dans l'environnement à purifier et décontaminer. Un plasma froid est généré à température ambiante, dont l'ozone est contrôlé en tant qu'indicateur et qui, conjointement avec la forme réactive de l'oxygène et le dioxyde d'azote généré, notamment par peroxydation, réduit drastiquement la charge bactérienne et réduit le nombre de particules en suspension de 50 %.
PCT/IT2021/050314 2020-11-24 2021-10-06 Système de purification et de décontamination d'air microbiologique et procédé automatique de purification et de décontamination d'air microbiologique pour environnements confinés WO2022113134A1 (fr)

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060257299A1 (en) * 2005-05-14 2006-11-16 Lanz Douglas P Apparatus and method for destroying volatile organic compounds and/or halogenic volatile organic compounds that may be odorous and/or organic particulate contaminants in commercial and industrial air and/or gas emissions
WO2009002294A1 (fr) * 2007-06-22 2008-12-31 Carrier Corporation Procédé et système pour utiliser un dispositif de génération d'ozone pour la purification de l'air
US20110274600A1 (en) * 2010-05-06 2011-11-10 Mineral Right, Inc. Ozone oxidation filtration and neutralization air cleaning system, apparatus & method
EP2653172A2 (fr) * 2012-04-20 2013-10-23 Laboratori Archa S.r.l. Apparail de traitement d`air avec generateur d`ions
US20190201564A1 (en) * 2017-12-29 2019-07-04 Tomi Environmental Solutions, Inc. Decontamination device and method using ultrasonic cavitation
IT201800009790A1 (it) * 2018-10-25 2020-04-25 Poloplasma Srl Sistema di purificazione aria in un impianto di ventilazione con uscita controllata
US10767879B1 (en) * 2014-02-13 2020-09-08 Gregg W Burnett Controlling and monitoring indoor air quality (IAQ) devices

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060257299A1 (en) * 2005-05-14 2006-11-16 Lanz Douglas P Apparatus and method for destroying volatile organic compounds and/or halogenic volatile organic compounds that may be odorous and/or organic particulate contaminants in commercial and industrial air and/or gas emissions
WO2009002294A1 (fr) * 2007-06-22 2008-12-31 Carrier Corporation Procédé et système pour utiliser un dispositif de génération d'ozone pour la purification de l'air
US20110274600A1 (en) * 2010-05-06 2011-11-10 Mineral Right, Inc. Ozone oxidation filtration and neutralization air cleaning system, apparatus & method
EP2653172A2 (fr) * 2012-04-20 2013-10-23 Laboratori Archa S.r.l. Apparail de traitement d`air avec generateur d`ions
US10767879B1 (en) * 2014-02-13 2020-09-08 Gregg W Burnett Controlling and monitoring indoor air quality (IAQ) devices
US20190201564A1 (en) * 2017-12-29 2019-07-04 Tomi Environmental Solutions, Inc. Decontamination device and method using ultrasonic cavitation
IT201800009790A1 (it) * 2018-10-25 2020-04-25 Poloplasma Srl Sistema di purificazione aria in un impianto di ventilazione con uscita controllata

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