WO2023170541A9 - Régénération de dispositif de filtration et de décontamination d'air - Google Patents

Régénération de dispositif de filtration et de décontamination d'air Download PDF

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Publication number
WO2023170541A9
WO2023170541A9 PCT/IB2023/052066 IB2023052066W WO2023170541A9 WO 2023170541 A9 WO2023170541 A9 WO 2023170541A9 IB 2023052066 W IB2023052066 W IB 2023052066W WO 2023170541 A9 WO2023170541 A9 WO 2023170541A9
Authority
WO
WIPO (PCT)
Prior art keywords
filter
filtration device
pack assembly
filtration
air
Prior art date
Application number
PCT/IB2023/052066
Other languages
English (en)
Other versions
WO2023170541A1 (fr
Inventor
Ezio Giovanni BOLZACCHINI
Luca Ferrero
Chiara ROSTAGNO
Giulio CEPPI
Moreno ARRIGONI
Marco Pozzi
Original Assignee
Università Degli Studi Di Milano - Bicocca
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Università Degli Studi Di Milano - Bicocca filed Critical Università Degli Studi Di Milano - Bicocca
Publication of WO2023170541A1 publication Critical patent/WO2023170541A1/fr
Publication of WO2023170541A9 publication Critical patent/WO2023170541A9/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D39/00—Filtering material for liquid or gaseous fluids
    • B01D39/10—Filter screens essentially made of metal
    • B01D39/12—Filter screens essentially made of metal of wire gauze; of knitted wire; of expanded metal
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D39/00—Filtering material for liquid or gaseous fluids
    • B01D39/14—Other self-supporting filtering material ; Other filtering material
    • B01D39/20—Other self-supporting filtering material ; Other filtering material of inorganic material, e.g. asbestos paper, metallic filtering material of non-woven wires
    • B01D39/2003—Glass or glassy material
    • B01D39/2017—Glass or glassy material the material being filamentary or fibrous
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D39/00—Filtering material for liquid or gaseous fluids
    • B01D39/14—Other self-supporting filtering material ; Other filtering material
    • B01D39/20—Other self-supporting filtering material ; Other filtering material of inorganic material, e.g. asbestos paper, metallic filtering material of non-woven wires
    • B01D39/2068—Other inorganic materials, e.g. ceramics
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D41/00—Regeneration of the filtering material or filter elements outside the filter for liquid or gaseous fluids
    • B01D41/04—Regeneration of the filtering material or filter elements outside the filter for liquid or gaseous fluids of rigid self-supporting filtering material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
    • B01D2239/065—More than one layer present in the filtering material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
    • B01D2239/065—More than one layer present in the filtering material
    • B01D2239/0654—Support layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/12—Special parameters characterising the filtering material
    • B01D2239/1208—Porosity
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/12—Special parameters characterising the filtering material
    • B01D2239/1216—Pore size
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2273/00—Operation of filters specially adapted for separating dispersed particles from gases or vapours
    • B01D2273/30—Means for generating a circulation of a fluid in a filtration system, e.g. using a pump or a fan
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2279/00—Filters adapted for separating dispersed particles from gases or vapours specially modified for specific uses
    • B01D2279/65—Filters adapted for separating dispersed particles from gases or vapours specially modified for specific uses for the sterilisation of air
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours

Definitions

  • the present invention lies in the technical field of air filtration devices based on multilayer filtration systems for indoor environments.
  • the present invention relates to a filtration device based on a multi-layer filtration system for filtering particulate pollutants made of inorganic, organic and/or biological material having a size (diameter) greater than 4 nm.
  • the present invention relates further to a method of decontaminating and regenerating the aforementioned filtration device.
  • Indoor environments represent a mix of outdoor pollutants, mainly associated to vehicular traffic and industrial activities, which may enter through infiltrations and/or natural and/or mechanical ventilation systems, as well as indoor contaminants originating from inside the building, from combustion sources, emissions from materials and furnishings, centralized heating and cooling plants, humidification systems, electronic equipment, cleaning products, house pets, and from the occupants’ behaviour (smoking, painting), etc.
  • Controlling the concentrations of respiratory aerosols in indoor environments, in order to reduce the transmission of infectious agents, is essential and may be achieved by controlling the source (face mask use, physical distancing) and by technical controls (ventilation and filtration).
  • SARS-CoV-2 may be transmitted via aerosols at a distance of more than two meters between people.
  • SARS-CoV-2 Apart from SARS-CoV-2, other airborne respiratory viruses can spread similarly to SARS-CoV-2 via main transmission routes, namely direct contact, respiratory droplets, and airborne transmission.
  • the third route that is the airborne route
  • respiratory viruses are ubiquitous in the environment, with virus particles constantly circulating in the air.
  • Airborne transmission of other respiratory viruses, such as influenza or rhinovirus has already been studied in hospitals, since aerosol transmission has been demonstrated as the most probable mode of transmission for adults.
  • US11105522 B2 discloses an air treating system, characterized by an air motor forcing air through the system itself, a pre-treating stage with a particulate filter for removing larger contaminants from the air, and an antimicrobial (e.g., copper and silver) filter for killing or damaging microorganisms, a UV chamber including an ultraviolet lamp and a catalytic (e.g., TiCh-coated) device, and a reflective (e.g., mirror-finish anodized aluminum) coating amplifying the UV radiation, so as to kill microorganisms, a post- UV step including a Volatile Organic Compounds (VOCs) reducing filter for removing odours and VOCs from the air.
  • VOCs Volatile Organic Compounds
  • US20210010692 Al discloses a system designed to withstand all chemical and biological contaminants in the air. Specifically, this system has been designed for killing the anthrax spore, the most difficult biological to kill. The system exists since more than 4 years, protecting and supporting the growth of the human embryo, the most sensitive cell.
  • the aim is to provide a transformational air purification technology (in-duct or in-room), in order to remove infectious pathogens.
  • the system envisages the purification, including filtering of the air through oxidizing and VOC adsorbing pre-filtration, secondary filtering of the air through UV filtration inside the system and final filtering of the air through the final particulate filtration downstream of the UV filtration.
  • the disclosure provides a method further comprising the stage of filtering the air through the particulate pre-filtration inside the housing, upstream of the VOC pre-filtration.
  • the system comprises further one or more filters containing carbon, KMnO4 and combinations thereof.
  • WO2019194890 A9 discloses a biological air purifier based on electrically filtering and removing contaminants by bio-oxidation.
  • the filtration concept is electrically based and does not have filtering barriers.
  • CN204478340U discloses a regenerative air purification system, applying to air- conditioning systems and ventilating systems.
  • the purification process and the regenerative process may be accomplished simultaneously, comprising: pre-filtration filters, a gas adsorbing filtration device, photocatalyst material (a mix of nano-titanium or titanium dioxide and active carbon absorbing material) for gases, a heating system for gases.
  • the filtration concept is based on filtering barriers and, subsequently, on gas traps.
  • W02010008336 Al discloses a method for capturing airborne agents or products of agents, such as microorganisms, including viruses and microbial antigens, toxins and allergens, comprising forming at least one trap for electrically charged aerosol (in emulsion, suspension form).
  • EP2466085 A2 refers to a centrifugal, wet-type air cleaner, with a centrifugal fan for generating a vortex flow, whereby pollutants may be eliminated centrifugally by creating a depressurized room on the basis of by simultaneous water atomization.
  • the document aims to provide the purification of indoor/outdoor air in different fields, using a centrifugal filtration concept with water atomization without filtering barriers.
  • US6872241 B2 refers to an anti-pathogenic air filtration medium comprising a fibrous substrate, the fibers thereof having featuring a coating comprising a polymer.
  • the coating provides a destructive environment for airborne pathogens.
  • the filter medium may be used in an indoor air treating system capable of both filtering the air and eliminating pathogens.
  • the filter medium may also be used to create a new bio-protective gas mask not only offering protection against chemical warfare agents, but also providing protection against biological pathogens.
  • the fibrous substrate is any natural or synthetic porous material made of a plurality of intermingled fibers.
  • the polymer is any polymer capable of withstanding acidic, basic, oxidizing or strongly solubilizing substances without decomposing.
  • air decontamination systems known from the state of the art are generally based on chemical or biological (e.g., bio-oxidation) and not thermal systems, or on the simple contaminants collection.
  • the technical task underlying the present invention is to provide a filtration device for filtering particulate pollutants made of inorganic, organic and/or biological material, which is free from the aforementioned drawbacks.
  • an indoor filtration device for filtering particulate pollutants made of inorganic, organic and/or biological material with a size (diameter) greater than 4 nm, having a filtration efficiency of 99.999 ⁇ 0.001%, and comprising: A) a three-layer filter pack assembly, the outer layers whereof comprise a silicon carbide (SiC) ceramic filter and the intermediate layer comprises a quartz fiber filter (QFF), and
  • NWF non-woven fabric
  • the aforementioned filtration device is of regenerating type and also has a SARS-CoV-2 inactivating action through a decontamination and regeneration method comprising a first stage of heating the aforementioned pack assembly, followed by SARS-CoV-2 inactivation, and/or a second stage of combustion of the collected particulate material, resulting in a biocidal action.
  • the inventive filtration system may be used for HVAC (“Heating, Ventilation and Air Conditioning”) applications, according to the size of the space to be treated, from applications in buildings/edifices (hospital, university/school, museum, cinema/theatre settings, etc.), down to smaller sizes, such as a single room (e.g., in food serving settings), to portable applications in household settings.
  • HVAC Heating, Ventilation and Air Conditioning
  • the filtration device of the invention is not based on induced filtration systems, based in turn on combinations of UV-A light and TiCh activated silicon carbide filters (photochemical mechanism), electrostatic deposition on honeycomb cells, biodegrading action.
  • the filtration device of the invention is responsible for an abrupt decrease of organic, inorganic and/or biological particulate matter concentrations, having a filtration efficiency of 99.999 ⁇ 0.001%.
  • FIG. 1 shows the operation diagram of a preferred embodiment of the filtration system of the invention, in terms of air intake and purification and heat treatment stages (100 °C and/or 600 °C, for SARS-CoV-2 inactivation and regeneration of the filtration system, respectively).
  • phrase according to which an item “ consists of or is made of or composed of one or more components means that the presence in the item of any additional component apart from the one/ones explicitly listed is excluded.
  • pack assembly is meant a multi-layer packing made of a plurality of overlapping filters.
  • each ceramic filter of the outer layers of said pack assembly A) has a porosity ranging from 25 to 70 ppi, preferably ranging from 30 to 65 ppi, more preferably equal to 60 ppi, and a thickness ranging from 0.8 to 1.2 cm, still more preferably equal to 1.0 cm.
  • nominal diameter is meant the one measured by the so-called particle retention liquid.
  • the principle underlying such a measuring technique is based on the premise that, in a filtration process, the particle retention efficiency of a depth filter is often expressed in terms of particle size (in pm) at which a certain retention efficiency level (e.g., 98%) is obtained.
  • the filtration efficiency is, in turn, determined by analysis of particle removal from a fluid, using particle counters: the original fluid, with a known suspended particle concentration, and the filtrate (fluid passing through the filter) are measured with an in-liquid particle counter.
  • the quartz fiber filter included in the intermediate layer of said pack assembly A has a nominal pore diameter ranging from 1.0 to 2.5 pm, preferably equal to 2.0 pm, and a thickness ranging from 0.35 mm to 0.40 mm, preferably equal to 0.38 mm.
  • the quartz fiber filter included in the intermediate layer of said pack assembly A) is heat resistant to a temperature of 900 °C and chemically resistant to SO 2 , HC1, SO 3 , SO 4 2 ', NO, and NO 3 ‘.
  • the final filter B) has a nominal pore diameter ranging from 1.0 to 2.5 pm, preferably equal to 2.0 pm, and a thickness ranging from 0.35 nm to 0.40 nm, preferably equal to 0.38 nm.
  • the final filter B) is heat resistant to a temperature of 900 °C and chemically resistant to SO2, HC1, SO3, SC 2 ', NO, and NO?’.
  • each ceramic filter of the outer layers of the pack assembly A) is configured to mechanically support and transfer heat to the quartz fiber filter (QFF) of the intermediate layer of the pack assembly A).
  • the pack assembly A may be possibly contained in a steel casing, depending on the application context.
  • the outer layers of the pack assembly A) contain means, preferably electric resistors, capable of heating the entire pack assembly A).
  • a further object of the present invention is the method of decontaminating and regenerating the filtration device 1 comprising the following steps: b-1) heating the pack assembly A) to 100 °C to inactivate the SARS-CoV-2 trapped in the intermediate layer of the assembly A) comprising the quartz fiber filter; and/or b-2) heating said quartz fiber filter contained in the assembly to 600 °C for combustion of all the collected particulate material resulting in a completely biocidal and regenerating action.
  • step bl may be repeatedly performed at regular time intervals ti, preferably ranging from 12 to 24 hours, followed by subsequent step b2), alternatively step b2) may be performed repeatedly at the aforementioned regular time intervals ti or at regular time intervals t2, preferably ranging from 24 hours to 30 days, depending on the treated air flow and on the environmental contamination level, wherein ti ⁇ t2.
  • FIG. 1 A preferred embodiment of the filtration device of the invention is schematically illustrated in FIG. 1, where the operation method of such a device in the filtrating stage indicated by a) in the Figure and in the bacterial/viral particle inactivating and regenerating stage (stage b) is also depicted.
  • the device is provided with a housing 2 having an inlet 3 suitable for receiving the pack assembly A), through which the air to be filtered in the environment enters said housing, and has at least one outlet 4, preferably two outlets, suitable for receiving the final filter B) made of quartz fiber on non-woven fabric supported on a steel mesh, through which the filtered air passes exiting from the housing 2.
  • the filtration device when used for indoor applications, it further comprises at least one active carbon odour filter to be located upstream of each outlet 4 and downstream of the inlet system 3.
  • the filtration device is provided with a fan 5, preferably located between the aforementioned inlet 3 and said at least one outlet 4, associated to the inlet 3, to facilitate the inflow of air to be filtered and the outflow of filtered air.
  • step a) of actually filtering polluted air enters the device 1 via the inlet 3 passing through the pack assembly A). By means of the fan 5, the filtered air is forced out from the at least one outlet 4.
  • stage b) of inactivating/regenerating the device is closed such that only the air inside the device circulates and the device is heated by resistors located inside the outer filters of the pack assembly A) until reaching the target inactivation (100 °C)/regeneration (600 °C) temperature.
  • the inactivation/regeneration of the filtration device 1 is facilitated, apart from the electric heating, by the air forced by the fan 5 to circulate and pass several times through the assembly A).
  • the developed system is based on a base laboratory prototype consisting of a three- layer pack assembly consisting of: a silicon carbide (SiC) ceramic filter having a porosity equal to 60 ppi, thickness equal to 1 cm; a quartz fiber filter (QFF, SiCh, thickness of 0.38 mm, 99.998% retention of particles having a diameter of 0.3 pm), heat resistant to a temperature of 900 °C and chemically resistant to SO2, HC1, SO3, SC 2 ', NO, NO?’, except for HF; a silicon carbide (SiC) ceramic filter having a porosity equal to 60 ppi, thickness equal to 1 cm; a final QFF filter applied on non-woven fabric (NWF) and steel mesh, located downstream of the three-layer pack assembly, defining a final security barrier for air purification and avoiding the release of fibrous material from the system.
  • SiC silicon carbide
  • NWF non-woven fabric
  • FIG. 1 The operation diagram of the system, in terms of air intake and purification and heat treatment stages (100 °C and 600 °C, for SARS-CoV-2 inactivation and regeneration of the filtration system, respectively) is shown in FIG. 1.
  • SiC silicon carbide
  • SiC silicon carbide
  • the filtration matrices were subjected to filtration test by determining the numerical concentration of particles upstream (outdoor air) and downstream (filtered air) of the same, using a total particle counter (particle diameter > 4 nm), having a measurement frequency equal to 1 Hz, and an optical particle counter (0.3 pm ⁇ particle diameter ⁇ 10 pm), having a flow rate equal to 2.7 cm/s.
  • the air subjected to the filtration treatment was the air from the urban atmosphere of Milan, taken in outdoor environment, which was representative of the most significant environmental and biological contaminations.
  • QFF filter mass was determined with a microanalytical balance having a sensitivity equal to 1 pg.
  • the silicon carbide (SiC) filter does not perform any significant filtering function, however it proves to be essential in providing the QFF filter with mechanical stability and as thermal conductor for regenerating the same at high temperatures.
  • the QFF filter shows a filtration efficiency > 99.99%.
  • the three-layer pack system (Packed test 1, SiC-QFF-SiC) shows an apparent filtration efficiency drop (94.736 ⁇ 1.581) due to the SiC particles released from the ceramic filters.
  • a final backup QFF filter laid out on a steel mesh grid downstream of the three-layer pack system (SiC-QFF-SiC) forms the final four-layer system (Packed test 2, SiC-QFF-SiC-QFF), ensuring the same performance in terms of filtration efficiency of the QFF filter and the biocidal and regenerating action.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Textile Engineering (AREA)
  • Ceramic Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Filtering Materials (AREA)

Abstract

Dispositif de filtration intérieur permettant de filtrer des polluants particulaires constitués de matériaux inorganiques, organiques et/ou biologiques présentant une taille (diamètre) supérieure à 4 nm, le dispositif présentant une efficacité de filtration de 99,999 ± 0,001 %. Ledit dispositif de filtration, du type à régénération et pouvant inactiver des particules de SARS-CoV-2, comprend : A) un ensemble filtre à trois couches, dont les couches externes comprennent un filtre en céramique à carbure de silicium (SiC) et la couche intermédiaire comprend un filtre en fibres de quartz (QFF); b) un filtre QFF final appliqué sur un tissu non tissé (NWF) et une maille d'acier.
PCT/IB2023/052066 2022-03-07 2023-03-06 Régénération de dispositif de filtration et de décontamination d'air WO2023170541A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT102022000004259A IT202200004259A1 (it) 2022-03-07 2022-03-07 Dispositivo di filtrazione e decontaminazione di aria rigenerante
IT102022000004259 2022-03-07

Publications (2)

Publication Number Publication Date
WO2023170541A1 WO2023170541A1 (fr) 2023-09-14
WO2023170541A9 true WO2023170541A9 (fr) 2023-12-07

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IT (1) IT202200004259A1 (fr)
WO (1) WO2023170541A1 (fr)

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04131109A (ja) * 1990-09-25 1992-05-01 Eagle Ind Co Ltd ２層構造ＳｉＣセラミックスフィルタおよびその製造方法
US6872241B2 (en) 2001-10-19 2005-03-29 Innovative Construction And Building Materials, Llc Anti-pathogenic air filtration media and air handling devices having protective capabilities against infectious airborne mircoorganisms
EP2300168B1 (fr) 2008-07-15 2019-10-02 3 Nine AB Procede et filtre pour la capture d'agents en suspension dans l'air
KR20110017800A (ko) 2009-08-14 2011-02-22 윤장식 원심분리 형식의 세정식 수평형 공기 조화기
US9597627B2 (en) 2014-10-19 2017-03-21 Wei Zhang (William) Regenerative air purification system and method
EP3775706A4 (fr) 2018-04-02 2021-12-29 LifeAire Systems, LLC Utilisations médicales résidentielles et en laboratoire d'air purifié
CA3093782A1 (fr) 2018-04-06 2019-10-10 U-Earth Biotech Ltd Systemes biologiques et procedes pour la purification de l'air
CN209481388U (zh) * 2018-12-04 2019-10-11 河南豫科玻璃技术股份有限公司 一种蒙砂生产废水处理装置

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IT202200004259A1 (it) 2023-09-07
WO2023170541A1 (fr) 2023-09-14

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