| WO2009002294A1 | 2008-12-31 | |||
| WO2001052910A1 | 2001-07-26 |
| IT201800009790A1 | 2020-04-25 | |||
| KR102138300B1 | 2020-07-27 | |||
| US20180361009A1 | 2018-12-20 |
| CLAIMS 1. Air sterilization system for confined spaces, said system being of a dry cold plasma type at room temperature, and being characterized in that it includes : • at least one HVAC module (10) with internal piping • at least one sensor module (70) • a plurality, preferably three, of modules (110) for generating the cold plasma • a plurality, preferably three, of modules (80), each equipped with a plurality, preferably six, of plasma discharge cards • at least one control module (90) containing commands and controls from power and control PLC (100), graphic interface (130) and Internet connection. 2. Air sterilization system for confined spaces according to claim 1, characterized in that it further comprises a controlled mechanical ventilation system comprising an air inlet duct (20) which carries the external air to a treatment unit air (10), wherein said air handling unit (10) comprises an inlet filtering module (16a), a sensor module (70) for analyzing the air inside the environment (120), and said control module (90), said system also comprising at least three valves (Ml, M2, M3) that can be controlled by the control module (90), two valves (Ml and M2 ) to close at the start of the sterilization cycle, and at the same time a valve (M3) to open and recirculate the air at 100% for the necessary time, while at the end of the cycle the valves (Ml and M2 ) open, and the valve (M3) closes, to make enter air from the inlet channel (20 ) , pass through the environment (120 ) , and exit from the exit (30 ) . 3 . Air sterilization system for confined spaces according to claim 1 or 2, characterized in that the graphic interface (130 ) allows generating n types of presets to adapt the system to the environment to be sterilized by programming the type of cycle to be applied, called graphic interface (130 ) also allowing to program high voltage pulse trains or "bursts" of sinusoidal shape, through dialogue with the power supply and control PLCs (100 ) . 4 . Air sterilization system for confined environments according to any one of the preceding claims, characterized in that the sensor module (70 ) is designed to detect in real time all entered parameters, the main one being that of ozone measured in ppm. 5. Air sterilization system for confined spaces according to any one of the preceding claims, characterized in that the graphic interface (130 ) is also designed to display the trends of each single parameter for a single hour or for 24 hours, scrolling with data in local memory for 7 consecutive days . 6. Air sterilization system for confined spaces according to any one of the preceding claims, characterized in that all systems are connected in the cloud to a remote site, in a virtual network, from which it is possible to detect any anomalies or failures, perform remote interventions, and update the software when necessary. 7 . Automatic process of sterilization of confined environments, in particular dedicated to aseptic isolators, said process being carried out with a system according to any one of the preceding claims, in which in said process the asepsis is obtained with cold plasma gas technology of air at room temperature . 8 . Process according to claim 7, comprising the steps of : - presetting data, i . e . : room volume, preferably set for 1 m3; flow rate, preferably set around 45 m3/h; air 3 exchange, preferably set to 1 in 0 .7 minutes so that the air can stagnate and have a slow exchange; delivery air speed, preferably set at 1 .3 m/sec; air speed in recovery, preferably set at 2 .4 m/sec; primary Ton plasma, preferably set at 100msec, the rest at zero in order to have a continuous discharge; ozone, preferably set with the minimum limits of 82 ppm and maximum of 84 ppm; alarm, preferably set at 130 ppm; NO2, preferably set from 0 to 20 ppm with alarm at 30 ppm; - saving the preset data with a name or code; switching on the sterilization system for confined spaces; - with the preset data selected, accessing the time slot and setting the system to on which will start immediately; - starting the fans, in which the first fan (12 ) pushes towards the heat recovery unit and the second fan ( 14 ) sucks the air towards the plasma boards, which in the meantime will discharge continuously, the air at speed crossing the set of cards and entering the environment (120 ) , and exiting slowly, reciprocating the environment (120 ) for 0 .7 times per minute; closing the shutter valves (Ml and M2 ) , while the shutter valve (M3) is open, in this way there is no exchange of air both inwards and outwards, the flow thus being forced to pass through channel (25) , enter PL1 and return to the same path until the valves (Ml, M2 ) open; the generated plasma continues to flow in the environment (120 ) and returns to pass through the high voltage boards; - at the same time, the sensors continue to measure all the parameters, the main indicator being ozone, which in about 6 minutes will rise to the maximum set value of 84 ppm, at which point the plasma generation will stop and start again only when the value will drop below the minimum value of 82 ppm, creating the sinusoidal curve that defines the sterilization cycle; - at the end of the cycle, the damper valves (Ml and M2 ) will open, the damper (M3) will close and the external air will flow into the sterilization chamber through the HEPA filter (130 ) cooling with filtered air; subsequently, the damper valves (Ml, M2, M3) will be able to return to their previous positions, safeguarding the internal air from external contaminants . |
The present invention relates to an air sterilization system dedicated to all aseptic isolators, in which total asepsis is required, defined as a series of procedures designed to prevent the access of microorganisms, pathogenic or not, to a sterile substrate of nature or artificially sterilized.
In particular, a pharmaceutical isolator is also defined as an equipment dedicated to both the handling of toxic/harmful powders and sterile products, divided into two separate compartments, one for work and one for the inlet and outlet of the product . Each compartment is equipped with a turbulent flow or vertical unidirectional ventilation device in class ISO 5 (ISO 14644/1 ) .
More specifically, the invention allows :
1 . the total elimination of the microbiological component suspended in the air, including spores, through a "dry" process using the plasma gas generated by the air,
2. the elimination of the suspended particle component,
3. the reduction in the number of air recirculations compared to the state of the art, 4 . the consequent reduction of the energy required to control the asepsis process .
In general, the invention refers to an internal air sterilization system for environments that require complete sterility, obtained with low temperature plasma, and which uses SDBD cold plasma generators for this purpose . The process is controlled using as indicators a controlled quantity of Ozone (03) and the relative quantity of Nitrogen
Dioxide (N02 ) .
The inlet and outlet air flows are controlled by a VMC system, with a series of sensors that ensure a repeatable and safe sterilization process according to the requirements defined by European standards, in particular ISO16644/1 .
Currently, controlled mechanical ventilation (VMC) is inserted in the isolators or in environments where complete sterilization is required, which exploits the presence of air ducts to allow the exchange/recycling of air within confined spaces . In this specific case, the VMC introduces air filtered by HEPA filters into an isolator that contains a manual or automatic handling/production line, and in which any human intervention is kept outside the same isolator, to avoid any contamination .
It is known that the main purpose of ventilation is 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 - ISO 8 ) .
It should be noted that the expression "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 in the percentage chosen according to the case remains, while on the inside the task of cont r ibut ing to the removal of microbial agents after filtering .
The ducts are used to carry out the air exchange : the system uses a fan to extract the contaminated air from the environment and a supply fan to bring inside the room air taken from the outside and filtered. During the sterilization cycle, the delivery and expulsion ducts are closed, with a closed cycle the air is recycled at 100%, while at the end of the cycle it is expelled at 30% and recycled at 70% .
The filters at the H14 inlet are used to stop up to
99. 995% any possible polluting particle in suspension and which can deposit on surfaces . Contaminated can be considered under two aspects :
1 . number of suspended particles starting from 0 .1 m but more generally measurable from 0 .5 m and defined as Particle
Matters (PM1 -2 .5-5-10 etc . ) .
2 . living microbes, such as viruses, bacteria, spores, molds and fungi which, in order to move in the air, need a support to anchor and feed on, generally dust and water droplets . These, being dimensionally larger than their transported hosts, are easily captured with adequate filtration .
But the major source of biological pollutants is man with its metabolic activity, the scales of the skin, nose, throat, hands, clothes, hair, shoes, etc . 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 . In the case of insulators, human personnel are kept outside, and pollutants can only penetrate inside through the ventilation ducts . The materials are introduced through the special compartment that underlies the same rules and then passed into the work compartment .
It is known that high efficiency filters (HEP A High
Efficiency Particulate Air filter) , type Hl 4, retain 99. 995% of the particles present in the air passing through them.
It is known that most particles and dusts are produced in the environment , therefore by passing all the air in an environment over and over again through suitable HEPA filters, the level of microbiological contamination should remain under control; provided that the maintenance of the filters has been adequate . As for the dilution of the environmental concentration of microbial agents, it 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 for dilution and maintenance within the correct limits of the environmental concentrations of gas and other gaseous pollutants, even in the case of anomalous emissions .
It is known that there are two main categories of controlled contamination or sterilization environments, such as pharmaceutical isolators for sterilization and clean rooms for decontamination .
The invention concerns aseptic isolators, the main use of which are drug production lines, and in general all manipulations that require complete asepsis, in class A.
Sterilization is usually controlled through absolute filters combined with systems that use steam, so-called VHP, which with hydrogen peroxide (H2O2 ) decontaminat e the internal environment of the isolator . The staff can only act from the outside using gloves . Sterilization by VHP is a validated and accepted method which, through nebulization or evaporation of 35% hydrogen peroxide, reduces the microbiological load up to the pre- established requirement, usually indicated as the achievement of a SAL (Sterility Assurance Level) of 4/ 61og hydrogen peroxide has an evident and proven sporicidal effect on a broad spectrum of microbial agents already at a low concentration and degrades into non-toxic by-products .
The verification of sterilization is carried out in the vast majority with biological indicators with controlled contamination of spores with a concentration of 106, of which growth must be stopped in 30 - 40 minutes .
Current methods of sterilization of confined spaces .
Limitations and drawbacks of the state of the art .
The types of processes used for hydrogen peroxide are related to the method of use of the same, i . e . in the form of dry vapor, wet vapor or ionized vapor . Each method uses a different application to transform peroxide into steam and/or micro-drops .
Dry method
Description : The dry vapor of hydrogen peroxide is obtained by injecting the liquid onto a heated plate, hit by a flow of hot air that acts as a conveyor to the chamber . In