Air treatment device and treatment method

Abstract

To provide an air treatment apparatus which easily collects gas, aerosols, flying granular matters and viral pathogens floating in the air and a processing method of the same.SOLUTION: An air treatment apparatus for collecting a collection object component when the air containing the collection object component passes therethrough comprises: a collection tank which stores conductive liquid and in which an upper surface thereof is opened; and an electrode plate in which a plurality of protrusion parts are fixed on a metal plate having a plurality of holes. The electrode plate is placed on an upper edge surface of the collection tank so that the tip of the protrusion part is opposed to the upper surface of the conductive liquid. When an electrostatic field is generated by supplying the electric charge to the protrusion parts, the conductive liquid stored in the collection tank is charged with the reverse electric charge to the electric charge supplied to the protrusion part by the electrostatic induction, ion wind occurs toward the upper surface of the conductive liquid from the tip of the protrusion part, and the collection object component is collected on the side of the conductive liquid.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an air treatment device and treatment method that applies the principle of an electrostatic field screen (electrostatic field curtain) formed by generating an electrostatic field to collect gases, aerosols, and flying particles floating in the air and eliminate droplet infection of viral pathogens. [Background technology]

[0002] In recent years, in response to the coronavirus disease (COVID-19) pandemic, the World Health Organization (WHO) has continually emphasized the paramount importance of environmental cleaning and disinfection, as well as the importance of hand hygiene, respiratory etiquette, physical distancing, and avoiding unprotected close contact with people with fever or respiratory symptoms. Respiratory infections are transmitted through droplets of various sizes. Droplets with a diameter of 5–10 μm or greater are called respiratory droplets, while droplets with a diameter of less than 5 μm are called aerosols (droplet nuclei). Recent studies have reported that the COVID-19 virus is not transmitted through the air, but is primarily transmitted between people through respiratory droplets and contact. Droplets are generated when people cough, sneeze, or talk, so capturing these respiratory droplets containing pathogens may prevent the spread of infection from person to person.

[0003] Generally, air purifiers use the mechanism of an electrostatic precipitator, and consist of a charging section that generates a corona discharge between electrodes to charge dust, and a dust collecting section that uses Coulomb force to attach the dust charged by this charging section to a dust collecting plate. For example, the electrostatic precipitator disclosed in Patent Document 1 includes a charging unit that generates a corona discharge between a discharge electrode and a counter electrode to charge dust particles in the air, and a dust collection unit consisting of a high-voltage electrode and a dust collection electrode that captures the charged dust. Multiple shared counter electrodes, each consisting of a counter electrode and a dust collection electrode, are arranged parallel to the airflow. A flat high-voltage electrode made of semi-insulating resin is placed between the shared counter electrodes. Multiple electrode support members made of semi-insulating resin are provided at predetermined intervals along the upstream end of the high-voltage electrode. A wire discharge electrode is supported by the electrode support members and positioned opposite the shared counter electrode. In this air purifier, airborne viruses are charged positively or negatively by corona discharge, and the charged viruses are then captured by a conductor charged with the opposite polarity. The captured viruses are then inactivated using ultraviolet light, ozone, or Cleverin.

[0004] Furthermore, Patent Documents 2 and 3 and Non-Patent Document 1 disclose the configuration of an air purifier manufactured by AirDog, Inc., a U.S. company. This air purifier is equipped with a special filter called a "TPA filter." The "TPA filter" consists of a pre-filter, an ionizing wire frame, a dust-collecting filter, and an ozone-removing filter. The "TPA filter" creates an electromagnetic field in the ionizing wire frame, charging harmful substances with positive ions, which attract and remove dirt onto the filter like a magnet. This mechanism is said to be capable of removing fine particles (0.0146 μm) smaller than viruses, which are 0.1 μm or less in size and difficult to remove with the paper filters (HEPA filters) used in general air purifiers. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 3702726 [Patent Document 2] US Patent 9868123B2 [Patent Document 3] US Patent 9735568B [Non-patent literature]

[0006] [Non-Patent Document 1] AirDog (Japanese corporation) website: https: / / airdogjapan.com / DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0007] However, conventional air purifiers and the electrostatic precipitator disclosed in Patent Document 1 require the troublesome task of cleaning clogged filters and the periodic replacement of the filters themselves. Furthermore, although the air purifiers manufactured by AirDog, Inc., a U.S. company, described in Patent Documents 2 and 3 and Non-Patent Document 1 are said to be less susceptible to filter clogging than conventional air purifiers, filter maintenance is required, and the device itself has a complex structure and is expensive.

[0008] In view of the above problems, the present invention aims to provide an air treatment device and a treatment method for easily capturing gases, aerosols, flying particles, and viral pathogens floating in the air. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the air treatment device of the present invention is a device that captures components to be captured when air containing the components passes through it, and is characterized in that it comprises a collection tank that contains a conductive liquid and has an open top, and an electrode plate with a metal plate with a plurality of holes and a plurality of protrusions fixed to it, the electrode plate being placed on the upper edge surface of the collection tank so that the tips of the protrusions face the top surface of the conductive liquid, and when an electric charge is supplied to the protrusions to generate an electrostatic field, the conductive liquid contained in the collection tank is charged with an electric charge opposite to the charge supplied to the protrusions due to electrostatic induction, and an ionic wind is generated from the tips of the protrusions toward the top surface of the conductive liquid, and the components to be captured are captured on the side of the conductive liquid.

[0010] When the conductive liquid is water, if the components to be captured are water-soluble, they will dissolve in the water and be captured; on the other hand, if the components to be captured are water-insoluble, they will be captured on the surface of the water. The conductive liquid may be held in a liquid holding material and stored in the collection tank, or may be stored in a gel state in the collection tank. Furthermore, when the conductive liquid is aqueous, similarly to the case of water described above, if the components to be captured are water-soluble, they will be captured within the conductive liquid, and if the components to be captured are water-insoluble, they will be captured on the upper surface of the conductive liquid. When the conductive liquid is oily, if the components to be captured are oil-soluble, they will dissolve in the conductive liquid and be captured, and if the components to be captured are oil-insoluble, they will be captured on the upper surface of the conductive liquid.

[0011] The electrode plate can be constructed by drilling holes in a metal plate using a punching die or laser processing, and then fixing multiple nail-like pointed metal rods. The protrusions preferably have sharp tips. The distance between the tips of the protrusions and the water surface should be adjusted so that it varies in proportion to the voltage applied to the tips. More specifically, the distance should be adjusted to about 5 to 15 mm.

[0012] The components captured include pathogens, pesticides, cigarette smoke, carbon dioxide, ammonia, formaldehyde, acetaldehyde, as well as gases, aerosols, and flying particles contained in the air.

[0013] The air treatment method of the present invention is a method for capturing components to be captured when air containing the components passes through, and is characterized in that the air treatment device comprises a collection tank containing a conductive liquid and having an open top, and an electrode plate having a metal plate with a plurality of holes and a plurality of protrusions fixed to it, the electrode plate is placed on the upper edge surface of the collection tank so that the tips of the protrusions face the top surface of the conductive liquid, and when an electric charge is supplied to the protrusions to generate an electrostatic field, the conductive liquid contained in the collection tank is charged with an electric charge opposite to the charge supplied to the protrusions due to electrostatic induction, and an ionic wind is generated from the tips of the protrusions toward the top surface of the conductive liquid, and the components to be captured are captured on the side of the conductive liquid.

[0014] The present invention is also characterized by a method for continuously monitoring the amount of components to be collected that have been recovered in a conductive solution using the air treatment method described above, by sampling the conductive solution to quantify the amount present in a certain amount of air. [Effects of the Invention]

[0015] The air treatment device and method of the present invention utilize the principles of an electrostatic screen and use a conductive liquid as an electrode to easily capture charged pathogens in water or other conductive liquids. It can also capture pesticides, cigarette smoke, carbon dioxide, ammonia, formaldehyde, acetaldehyde, and other airborne gases, aerosols, and particles. No filters are required, and maintenance requires only water changes, making it highly convenient. Furthermore, any inactivating agent, such as Cleverin, can be added to the water, allowing for the recovery of highly polar substances that dissolve in water, enabling the recycling of inactivated substances. Furthermore, the captured pathogens can be recovered alive, enabling monitoring. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a perspective view showing an air treatment device 1 according to the present invention. [Figure 2] 1 shows an electrode plate 10 of an air treatment device 1 according to the present invention. [Figure 3]1 is a diagram illustrating the basic principle of an air treatment device 1 according to the present invention. [Figure 4] FIG. 2 is a diagram showing a state in which an ionic wind is generated in the air treatment device 1 according to the present invention. [Figure 5] 1 is a conceptual diagram showing how a target component X is captured in a conductive liquid F by generating an ionic wind in an air treatment device 1 according to the present invention. [Figure 6] FIG. 2 is a diagram showing an air treatment device 2 according to a second embodiment of the present invention. [Figure 7] 10 is a graph showing the relationship between the voltage applied to the air treatment device 2 in the electric field and corona discharge (a), negative ion generation (b), and the volumetric flow rate of ionic wind (c). [Figure 8] (a) is a graph showing FITC captured in the ground water of the air treatment device 2 negatively charged at different voltages, and (b) is a graph showing the capture of FITC and the generation of negative ions in the electric field of the air treatment device 2. [Figure 9] This is a schematic diagram of the total system TS, which includes three interconnected air treatment units and an ozone generator (OG). [Figure 10] FIG. 10 is a schematic diagram of an ozone generator used in a total system according to a third embodiment. [Figure 11] 10A is a graph showing the positive correlation between ozone productivity and the voltage applied to the ozone generator used in the total system of Example 3, and FIG. 10B is a graph showing the time course of the lethality of phages exposed to microbubbles generated by the ozone generator. [Figure 12] 10(a) is a graph showing the capture of phages sprayed into the air using air treatment devices 1 to 3 of the air treatment devices used in the total system according to Example 3. FIG. [Figure 13] 1 is a diagram illustrating the formation of electrostatic and static electric fields in a prior art electrostatic field screen generator; BEST MODE FOR CARRYING OUT THE INVENTION

[0017] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each drawing, the same parts are given the same numbers, and duplicate explanations will be omitted. Please note that the drawings may be exaggerated to facilitate understanding of the present invention, and are not necessarily drawn to scale. The technical scope of the present invention is not limited to the specific applications, shapes, dimensions, etc. shown in the following embodiments. Hereinafter, embodiments of the air treatment device of the present invention will be described with reference to the drawings.

[0018] The present invention is the result of further improving upon the principles of an electrostatic field screen generator previously developed by the inventor, specifically the SD-screen (single-voltage, bipolar electrostatic field screen). Before describing the embodiments, the principles of the SD-screen shown in the prior art (Patent No. 5252449) will be explained with reference to Figure 13. The coating 01 is made by inserting an iron rod 01a into soft vinyl chloride 01b. On one side of this coating 1 is a stainless steel earth mesh (earth electrode) 02. The coating 01 and the earth mesh 02 (earth electrode) are spaced 3 mm apart, with the layers parallel to each other. When a voltage is applied to the coating 01, an electrostatic field is generated around each coating. The earth mesh 02 (earth electrode) is then inserted into this electrostatic field. Then, for example, when a negative voltage is applied to the coating 01, the side of the earth mesh 02 (earth electrode) facing the coating becomes positively polarized. That is, by inserting an earth mesh 02 (earth electrode) into the electrostatic field, a pair of positive and negative electrodes is created in the electrostatic field space, and an electric field (hereinafter referred to as a "static electric field") is formed inside the electrostatic field. This static electric field constantly exerts a force pushing mobile charges from the negative pole (covering 01) to the positive pole (earth mesh 02). When an insect or other insect enters, the charge it carries is pushed out, and the pushed-out charge is absorbed by the earth mesh 02 (earth electrode). When this happens, the insect or other insect that has lost its charge becomes positively charged, and is strongly attracted and captured by the negative pole (covering 01). This principle is also known as the "electric field generation method." The electric field generation method is a groundbreaking technology for controlling biotic and non-biological harmful substances in the air that cause public health problems. These include infectious particles such as viruses, bacteria, and mold spores, pollen grains that cause hay fever, small flying pests that pass through ordinary insect nets, some allergens, and cigarette smoke that causes passive smoking. Existing electric field generation methods all directly capture the components to be captured in the electric field. It will be understood that the present invention utilizes the above-mentioned principle, uses water as an electrode, and captures charged components to be captured in the conductive liquid such as water itself, and has been proposed with the aim of reducing costs. Example 1

[0019] In the first embodiment, the basic structure of the air treatment device 1 and the basic principle of capturing components to be captured will be described with reference to the drawings. First, the basic structure of the air treatment device 1 will be described. Fig. 1 is a perspective view showing the air treatment device 1 according to the present invention. Fig. 2 is a diagram showing the electrode plate 10 of the air treatment device 1 according to the present invention, where (a) is a plan view and (b) is a perspective view looking up obliquely from below. Fig. 3 is a diagram for explaining the basic principle of the air treatment device 1 according to the present invention.

[0020] Please refer to Figures 1 to 3. As shown in Figures 1 to 3, air treatment device 1 of the present invention comprises collection tank 11 which contains conductive liquid F and has an open top, and electrode plate 10 which has a plurality of protrusions 101 fixed to metal plate 100 which has a plurality of holes 102. When air containing components to be captured passes through collection tank 11, the components to be captured are captured, and the air A which has passed through is purified. Electrode plate 10 is placed on the upper edge of collection vessel 11 so that the tips of protrusions 101 face the top surface of conductive liquid F. An electric charge is applied to electrode plate 10 from voltage application device 12 via lead wire L. Furthermore, conductive liquid F contained in collection vessel 11 is grounded via lead wire L. Electrode plate 10 can be constructed by forming holes 102 in a metal plate using a punching die or laser processing to form substrate 100, and fastening multiple nail-like pointed metal rods as protrusions 101. It is preferable that protrusions 101 have pointed tips. It is also preferable that the distance between the tips of protrusions 101 and the surface of conductive liquid F varies in proportion to the voltage applied to the tips. More specifically, it is preferable that this distance be adjusted to approximately 5 to 15 mm to prevent excessive discharge.

[0021] Next, the basic principle of the capture of the target component X by the air treatment device 1 will be described with reference to the drawings. Fig. 4 is a diagram showing the state in which an ionic wind is generated in the air treatment device 1 according to the present invention, and Fig. 5 is a conceptual diagram showing the state in which the target component X is captured in the conductive liquid F by the generation of the ionic wind in the air treatment device 1 according to the present invention.

[0022] Please refer to FIG. 4. FIG. 4 is a diagram showing the state in which an ionic wind is generated in the air treatment device 1 according to the present invention. (a) shows the state before a charge is applied to the electrode plate 10, (b) shows the state after a charge is applied to the electrode plate 10, and (c) shows the state after an ionic wind I is generated. In Example 1, as shown in FIG. 4(b), a negative charge is supplied to the electrode plate 10 from the voltage application device 12, and an electrostatic field is generated between the protrusions 101 and the conductive liquid F. That is, the conductive liquid F contained in the collection tank 11 is charged by electrostatic induction with a charge opposite to the charge supplied to the protrusions 101, i.e., a positive charge. As a result, as shown in FIG. 4(c), an ionic wind I is generated from the tip of the protrusions 101 toward the upper surface of the conductive liquid F. Note that, here, the dielectric coating 11 is a negative electrode, and is a negative-electrode dielectric coating. However, it is also possible to reverse the polarity and configure it as a positive-electrode dielectric coating. The principle is the same except for the polarity being reversed, so a description of the configuration with reversed polarity will be omitted.

[0023] 5A and 5B are conceptual diagrams showing how an ionic wind is generated in air treatment device 1 according to the present invention to collect component X in conductive liquid F. FIG. 5A shows air A containing component X entering a collection tank, and FIG. 5B shows component X being collected in conductive liquid F. FIG. 5A shows the same state as FIG. 4C. In this state, when air A containing component X passes through multiple holes 102 in electrode plate 10 and enters the collection tank, ionic wind I is generated, causing component X to be collected near conductive liquid F. Then, component X is collected from air A, which is processed into air Ac. Air A then bounces off the surface of solution F due to the generation of ionic wind, and exits collection tank 11 as indicated by the arrow.

[0024] When the conductive liquid F is water and the component X to be captured is water-soluble, the component X will dissolve in the water and be captured; on the other hand, when the component X to be captured is water-insoluble, the component X will be captured on the top surface of the water. Furthermore, the conductive liquid F may be held in a liquid holding material such as a sponge and stored in the collection tank 11, or may be stored in the collection tank 11 in a gel form such as agar. Furthermore, when the conductive liquid F is aqueous, similarly to the case of water described above, if the component X to be captured is water-soluble, the component X will dissolve in the conductive liquid F and be captured, whereas if the component X is water-insoluble, the component X will be captured on the upper surface of the conductive liquid F. An example of an aqueous conductive liquid is aqueous alcohol. When the conductive liquid F is oily, if the component X to be captured is oil-soluble, the component X will dissolve in the conductive liquid F and be captured, and if the component X is oil-insoluble, the component X will be captured on the upper surface of the conductive liquid F. An example of an oily conductive liquid is oily alcohol.

[0025] The components to be captured include pathogens, pesticides, cigarette smoke, carbon dioxide, ammonia, formaldehyde, acetaldehyde, as well as gases, aerosols, and flying particles contained in the air. Example 2

[0026] Second Embodiment An air treatment device 2 shown in the second embodiment will be described as a pathogen trapping device for trapping pathogens contained in the air. Figure 6(a) is a schematic diagram of an air treatment device 2 consisting of a perforated stainless steel plate 20 with a pointed protrusion 201 and a water container 21, and (b) is a cross-sectional view of the electric field between the tip of the pointed protrusion 201 and the surface of grounded water F. The arrow in Figure 6(b) indicates the direction of ionic wind I generated in the electric field.

[0027] As shown in FIG. 6(a), the air treatment device 2 used in Example 2 was a stainless steel metal plate 200 (4×20 cm) with a plurality of round holes 202 at regular intervals. 2 , thickness 0.5 mm), and a container (bottom area 24 × 6 cm) for holding water as a collection tank 21. 2, and wall height 6 cm). More specifically, the electrode plate 20 was constructed by attaching 20 pins (pinhead diameter 5 mm, needle length 8 mm) to a metal plate 200 with conductive double-sided tape. As shown in FIG. 6(b), the electrode plate 20 is housed in a square housing 23 (4 × 20 cm) with four legs. 2 , 10cm high) at the open bottom edge. The housing 23 with the electrode plate 20 attached was placed over a collection tank 21 filled with water (100 mL) so that the tip of the pointed protrusion 201 was immersed in the water, and an earth wire was inserted into the water. In addition, the end of the adhesive tape on the electrode plate 20 was connected to a DC voltage application device 22 (current limit 10 mA) (AMA-20K10NKBX1, Max-Electronics, Tokyo, Japan) via a lead wire L, and the electrode plate was negatively charged with a different voltage. In Example 2, the negative surface charge on the tip of the pointed protrusion 201 of the electrode plate 20 causes electrostatic induction in the water, generating an opposite surface charge in the grounded water (positively charged water). An electric field (electrostatic field) is formed between these oppositely positive and negative charges. The movement of free electrons from the electrode plate 20 side to the ground on the water side was measured using two galvanometers G (PC7000; Sanwa Electric Instruments, Tokyo, Japan) built into the ground wire.

[0028] In Example 2, an experiment was carried out using the air treatment device 2 described above to prove the basic principle of the present invention, which will now be described in detail.

[0029] Fluid samples containing viruses and bacteria can be atomized using an appropriate nebulizer. In Example 2, the inventors atomized water and microbial samples using a nebulizer that generates mist particles with a mass median diameter (MMD) of 5 μm. They demonstrated that the atomized samples could be collected using the air treatment device 2 of the present invention. The size range of the generated mist particles was 1–10 μm, with over 50% of the generated particles having a diameter of approximately 5 μm. This size range corresponds to the size of respiratory droplets (5–10 μm) and aerosols (≦5 μm). In this experiment, a pathogenic bacteriophage (phage) φ6 of Pseudomonas syringae var. syringae was used as a model for the COVID-19 virus. This phage has a lipid envelope and spikes, and has a hexagonal icosahedral structure similar to the COVID-19 virus.

[0030] The viral phage φ6 (NBRC105899) and the host bacterium P. syringae var. syringae (MAFF810047) were purchased from the National Institute of Technology and Evaluation (NITE) in Tokyo, Japan. The phage was propagated by lytic infection in host bacterial cells, precipitated with polyethylene glycol, and purified by centrifugation as previously described. The resulting phage particle pellet was dissolved in sterile water and diluted to measure the plaque-forming units (PFU) per ml by double-layer agar assay. Specifically, the phage solution was mixed with an overnight culture of host bacterial cells. Next, this mixture was mixed with molten agarose (0.6% w / v) and finally poured onto SSE medium solidified with agar (1.2% w / v) in a Petri dish. After overnight incubation, plaques were counted. The phage solution was diluted to 10 6 , 10 7 , 10 8 The concentration was adjusted to PFU / mL and used for atomization as described below.

[0031] The corona discharge (continuous corona current) constantly generated from the tip of the pointed protrusion 201 of the electrode plate 20 was measured in the voltage range of -1 to -10 kV, and exerted an attractive force on the mist particles. The current due to the corona discharge was recorded with a built-in galvanometer, and the corona discharge beam was photographed with a long exposure in the dark field. In addition, the velocity of the airflow (ionic wind I) generated by the corona discharge from the tip of the pointed protrusion 201 of the electrode plate 20 to the water surface was measured at the upper outlet of the air treatment device 2 using a highly sensitive anemometer (Climomaster 6533; Kanomax, Tokyo, Japan), and Q (m 3 / min)=V(m 2 ) × A (m / s) × 60 (s) to calculate the volumetric flow rate (m 3 / min) was calculated. Furthermore, the number of negative ions contained in the airflow was estimated using a Geldien air ion counter (NKMH-103; Hokuto Denshi, Hyogo Prefecture) installed outside the air outlet.

[0032] In this experiment, a liquid sample containing fluorescein isothiocyanate (FITC) (Fujifilm Wako Pure Chemical Industries, Osaka, Japan) or phage particles was atomized using a compressor-type nebulizer (atomizer) (NE-C-28; Omron Corporation, Kyoto, Japan) (built-in water tank capacity: 7 mL; mist generation rate: 0.35 mL / min; MMD: 5 μm). The nebulizer nozzle was installed 20 cm above the air treatment device 2, and the mist was sprayed into the rectangular housing 23.

[0033] In the first experiment, FITC water (100 μg / mL) was continuously sprayed toward an uncharged air treatment device 2. Visual observation confirmed that mist particles bounced off the water surface and were repelled by the spray force. Next, the electrode plate 20 of the air treatment device 2 was negatively charged at different voltages (-1 to -10 kV), and FITC water was sprayed for 30 seconds. The amount of mist particles captured on the water surface (the amount of FITC transferred from the mist particles to the water surface) was measured at each voltage. The amount of FITC in the water was estimated from a previously prepared optical density-based calibration curve. The capture of the FITC mist was videotaped under illumination by a blue light-emitting diode (Asahi Electric, Osaka).

[0034] In the second experiment, phage samples (10 5 -10 7 PFU / mL) was injected into the air treatment device 2 charged with different voltages (-3 to -10 kV) for 1 minute. The amount of phage particles captured on the water surface was measured by the double-layer agar method described above.

[0035] Here, a discharge is defined as the generation of a current corresponding to the potential difference between opposing poles due to dielectric breakdown of a gas in an electric field. If one pole (the receiving pole) is grounded, this conductor receives unlimited electrical charge (in this experiment, the maximum current of the voltage application device was 10 mA), making discharges more likely. In an electric field, a corona discharge first occurs. As the applied voltage increases or the distance between the poles decreases, this changes from a glow discharge (or surface discharge) to a brush-like discharge, and then an arc discharge occurs between the poles, resulting in the discharge cessation. The focus of this experiment is the generation of glow and corona discharges in an electric field, where multiple negatively charged metal protrusions generate negative ions and ionic wind I toward the water surface according to previously reported principles.

[0036] As shown in Figure 6(b), in the electrostatic configuration of the air treatment device 2, the high voltage generated by the Cockcroft circuit of the voltage application device 22 picks up electricity from the ground and supplies it to the tip of the pointed protrusion 201 of the electrode plate 20, and the negative surface charge pushes the free electrons of the water toward the ground, creating the opposite pole, i.e., the positive pole. In the air treatment device 2 according to the present invention, when a discharge occurs at the negative pole (the tip of the pointed protrusion), electricity (free electrons) forms an electrical circuit moving from ground to ground. Corona discharge occurs when the strength of the electric field (potential gradient) around a pointed metal conductor is strong enough to form a conductive area, but not strong enough to cause electrical breakdown or arc discharge in nearby objects. In the air treatment device 2, which is an electrostatic device according to Example 2, the tip of the charged pointed protrusion 201 faces the water surface, generating an electric field. In this electric field, corona discharge constantly occurs from the tip of the pointed protrusion 201 of the electrode plate 20 toward the water surface.

[0037] Next, an experiment relating to the air treatment device 2 will be described. Test date: February 2021 Experiment location: Kinki University Pharmaceutical Research Institute All experiments were repeated five times, and data are presented as mean values ​​and standard deviations. Analysis was performed using EZR software version 1.54 (Jichi Medical University, Saitama, Japan) to clarify significant differences between conditions and correlations between factors. Figure 7 shows the relationship between the applied voltage in the electric field of the air treatment device and corona discharge (a), negative ion generation (b), and the volumetric flow rate of ionic wind (c). (d) shows the relationship between the volumetric flow rate of ionic wind and the amount of negative ions generated.

[0038] FIG. 7(a) shows the relationship between the applied voltage and the amount of corona discharge generated. In the air treatment device 2 according to Example 2, when the applied voltage is in the range of -6 to -10 kV, the corona discharge generation current increases in proportion to the applied voltage. As shown in Figure 7(b), measurements using an ion detector confirmed that the larger the voltage, the greater the amount of negative ions generated. Here, ionic wind I is defined as the airflow caused by electrostatic forces linked to corona discharges generated at the tip of a sharp conductor (such as a point or blade) that is applied with high voltage to the ground. As shown in Figure 7(c), there is a clear correlation between the applied voltage and the amount of ionic wind I generated, and it was found that the amount generated increases in proportion to the applied voltage. 7(d), there is a positive correlation between the volumetric flow rate of the ionic wind I and the number of negative ions contained in the ionic wind I. The ionic wind was blown toward the water surface from the sharp tip of the pointed protrusion 201 of the electrode plate 20. The ionic wind I generated by the air treatment device 2 was strong enough (1.5 to 2.0 m / s) to draw outside air into the electric field of the air treatment device 2.

[0039] In a corona discharge-generating electric field, a suitably charged non-insulated conductor electrode generates a corona discharge against an opposite electrode placed at an appropriate distance, secondary generating numerous charges in the surrounding air. These charges are imparted to the component X to be collected, thereby charging the component X. In this electric field, the charged component X to be collected is attracted to the opposite electrode. In the configuration of air treatment device 2, the water surface can be said to function as a positively charged collecting electrode.

[0040] The graph in Figure 8 will be explained. Figure 8(a) is a graph showing FITC captured in the ground water of the air treatment device 2 negatively charged at different voltages. A mist containing FITC was sprayed for 30 seconds. The average value and standard deviation were calculated from five repeated experiments. The letters (ac) in each column indicate significant differences (p<0.05) using Tukey's method. Figure 8(b) is a graph showing the capture of FITC and the generation of negative ions in the electric field of the air treatment device 2. There is a positive correlation between the capture of FITC in the electric field of the air treatment device 2 and the generation of negative ions.

[0041] In the first assay to capture phage-free mist particles, water containing FITC was sprayed from the atomizer. Mist particles from the atomizer were visible. Indeed, the mist particles reached the water surface and bounced off. This method allowed for a simple and effective determination of the optimal voltage to be applied to the air treatment device 2 to stop the mist from bouncing off. This method allowed for a simple and effective determination of the optimal voltage to be applied to the air treatment device 2 to stop the mist from bouncing off. In this example, it was found that the bouncing of mist particles was suppressed when the voltage applied to the air treatment device 2 was −8 kV. Furthermore, it was found that when the FITC mist was continuously injected into the air treatment device 2 at this voltage, the amount of FITC dissolved in the water continuously increased.

[0042] As shown in Figure 8(a), the change in the amount of FITC integrated on the water surface of the collection tank 21 in the air treatment device 2 negatively charged at different voltages is shown. These results strongly indicate that the water surface functions as a collection electrode for mist particles, and that the mist particle collection ability increases in direct proportion to the applied voltage. Furthermore, as shown in Figure 8(b), there is a positive correlation between the amount of negative ions generated and the amount of FITC mist captured in the voltage range of -6 to -10 kV. These results strongly suggest that negative ions are involved in the electrostatic attraction of particles in the electric field of the air treatment device 2. Thus, the results obtained are consistent with the prediction that negative ions can ionize mist particles, generating an attractive force toward the opposite charge on the water surface.

[0043] The following Table 1 illustrates the number of plaques produced by phage φ6 particles recovered from the groundwater of air treatment unit 2. In the second assay, sample solutions with different phage concentrations were injected into the air treatment device 2, which was charged between -3 and -10 kV. An aliquot (100 μL) of G-WT was taken and the concentration of phage captured on the water surface was measured. The results showed that the water surface captured phage-carrying mist particles, and the number of captured phages increased gradually with increasing applied voltage, reaching a plateau between -8 and -10 kV. From these results, we concluded that the air treatment device can sufficiently capture phage-containing mist particles if it is charged with a negative voltage of 8 kV or more. Furthermore, the results of this study revealed that the capture of mist particles by the air treatment device 2 occurs regardless of the concentration of phages contained in the mist particles. As described above, the capture of mist particles relies on the ionization of the surface of the mist particles with negative ions, followed by their attraction to the opposite pole. These results suggest that air treatment device 2 can be applied to various droplet-transmitted bacterial diseases (diphtheria, whooping cough, meningitis, plague, pneumonia), viral diseases (influenza, meningitis, mumps, rubella, pneumonia), and pathogens such as mycoplasma. [Table 1] Example 3

[0044] Example 3 will be described with reference to the drawings. A total system TS including an air treatment device shown in Example 3 will be described as a system for capturing pathogens contained in the air, similar to Example 2. Figure 9 is a schematic diagram of a total system including three interconnected air treatment devices 4 and an ozone generator OG. The symbols in Figure 9 that are not listed in the symbol column below are as follows: WST: water supply tank, PVG: positive voltage application device, WDT: water drain tank, P1: piping from the water supply tank to the water containers of each air treatment device, P2: piping from the water containers of the air treatment device to the water drain tank. Figure 10 is a schematic diagram of an ozone generator OG designed to sterilize phages captured in grounded water. The arrows indicate the direction of the airflow from the axial fan AF. The symbols shown in Figure 8 are as follows: PCC is a polyvinyl chloride cylinder, AF is an axial fan, PVG is a positive voltage application device, S-SP is an electrode plate with a pointed protrusion, G-SP is a grounded stainless steel plate, FSF is a funnel-shaped pipe joint, OET is an ozone release tube, CF is an activated carbon filter, AEP is an air exhaust port, WV is a water valve, WI is a water inlet, MB is a microbubbler, WDT is a wastewater tank, and WDP is a wastewater outlet.

[0045] Figure 9 shows a complete system consisting of three air treatment devices 3A, 3B, and 3C and one ozone generator OG. The three identical air treatment devices 3A, 3B, and 3C (1 m long, 50 protruding tips) are connected to each other and to a negative voltage application device 32. The water in the collection tank 31 is connected to a ground wire L. Each collection tank 31A, 31B, and 31C is connected to two pipes, one from the water supply tank and the other from the wastewater tank WDT. The ozone discharge pipe OET of the ozone generator OG is connected to a microbubbler MB and inserted into the wastewater tank WDT. The electrode plates 30A, 30B, and 30C of the air treatment devices 3A, 3B, and 3C are charged at -10 kV to capture mist particles containing atomized phage. The electrode plates S-SP of the ozone generator OG, each with protruding tips, are charged positively at +10 kV to generate ozone.

[0046] First, the structure of the ozone generator OG will be described. As shown in Figure 10, the ozone generator (OG) consisted of five identical stainless steel plates (10 × 20 cm²; 2 mm thick). Two of the plates served as electrode plates, with 50 metal pins attached to both sides with conductive adhesive tape to form pointed protrusions. These were connected to a DC positive voltage generator (current-limited, 10 mA) (AMF-10K1PNX2 / 100, Max-Electronics, Tokyo, Japan). The other three served as grounded dielectric plates. The two electrode plates and three dielectric plates were arranged horizontally, alternating with 17 mm spacing (double-layer method; the distance between the tips of the pointed protrusions and the surfaces of the dielectric plates was 9 mm). The stainless steel plates arranged as described above were fixed in a polypropylene frame and placed inside a transparent acrylic cylinder (10 cm diameter, 30 cm length). A vinyl chloride tube of the same size was connected to one side of the cylinder, an axial flow fan was attached to the other side, and a tube (diameter 2 cm, thickness 0.5 mm) with a funnel-shaped pipe joint was connected to the other side of the cylinder.

[0047] For the phage sterilization assay, the ozone generator OG was positively charged at the highest voltage (+10 kV) that did not cause mechanical discharge (arc discharge) between the S-SP and G-SP. A microbubbler (Japan Azu, Kanagawa Prefecture) generating fine bubbles (0.5-20 μm in diameter) was connected to the tip of the ozone jet tube and inserted into the phage-containing water (108 PFU / mL) in a draining tank. The exhaust from the tank was passed through an activated carbon adsorbent to capture ozone that leaked from the solution. Ozone bubbling was continued for different periods (5-40 min) to determine the optimal bubbling time for inactivating all phages in the water. After bubbling, aliquots of the ozone-bubbled water were collected and the phage viability was examined using the double-layer method described previously.

[0048] In addition, two experiments were conducted to evaluate the feasibility of practical application of this system. Test date: February 2021 Experiment location: Kinki University Pharmaceutical Research Institute In the first experiment, three air treatment units 3A, 3B, and 3C were installed in an unventilated cubic cabinet (2 m side length) and charged with a voltage of -10 kV. Five mL of phage sample (10 8 Air treatment devices 3A, 3B, and 3C were operated continuously (30 min) during and after spraying 1000 PFU / mL (1000 PFU / mL) into the air for 5 min. Successful phage trapping was confirmed by taking aliquots from the water discharged from air treatment devices 3A, 3B, and 3C after the 30 min trapping operation. In this experiment, the effectiveness of phage trapping was compared between a single air treatment device and a dual air treatment device operated in the same manner. In the second experiment, the phage sample (5 mL, 10 8 After a specific time (15 to 120 minutes) had elapsed, the triple air treatment devices 3A, 3B, and 3C (charged at -10 kV) were operated continuously for 30 minutes. The water in the collection tanks 31A, 31B, and 31C of the air treatment devices 3A, 3B, and 3C was transferred to a draining tank, and the number of phages obtained in each trapping operation was measured. The number of phages was measured using the method described above.

[0049] Sterilization of trapped pathogens is the final step in precipitating them in the air. For this purpose, various physical and physicochemical methods have been used, including the use of gamma rays, ultraviolet light, ozone, plasma, and the application of various antibacterial chemical reagents. In this invention, ozone was used as a simple and inexpensive method to kill trapped pathogens because the ozone generator (OG) could be easily constructed with simple modifications to the air treatment equipment structure. In fact, the simple structure of the ozone generator (OG) makes it practically easy to manufacture and economical. While most commercially available ozone generators are variations of the high-voltage discharge method, the ozone generator (OG) described in this application is based on the same physical principle. Ozone can be effectively generated between a positively charged pointed protrusion and an oppositely negatively charged grounded metal plate.

[0050] Ozone acts as an antibacterial agent and effectively kills viruses, bacteria, fungi, and other organisms in water. Sterilizing solutions infested with pathogens requires bubbling ozone air containing a certain concentration of ozone and an appropriate exposure time. In the system described in this study, a microbubbler was used to generate fine bubbles (approximately 20 μm in diameter) of ozone air from the ozone generator OG. Under the current conditions of continuous aeration, the bubbles persisted in the ozonated solution, only slightly decreasing during operation.

[0051] Please refer to Figure 11. Figure 11 shows the positive correlation between ozone productivity and the voltage applied to the ozone generator (a) and the time course of the lethality of phages exposed to microbubbles generated by the ozone generator (b). The average values ​​and standard deviations in Figure 11(b) were calculated from five repeated experiments. The letters (a-d) in each column indicate significant differences (p<0.05) by Tukey's method.

[0052] As shown in Figure 11(a), there is a clear correlation between the amount of ozone generated and the applied voltage in the voltage range (+7 to +10 kV) where no mechanical discharge occurs. In other words, the ozone productivity improves in direct proportion to the applied voltage in this voltage range. In addition, to inactivate phage particles in water, the ozone generator OG was charged at +10 kV, as shown in Figure 11(b). The optimal ozone bubbling time required to completely kill the phages is shown. The results indicate that 30 minutes of bubbling is sufficient to completely kill the phages for safe discharge.

[0053] The total air treatment system TS is a practical tool for capturing and inactivating phages in mist particles sprayed into the air. Respiratory droplets are formed when a person coughs, sneezes, or speaks, and typically settle after traveling a short distance (usually less than 1 m). These droplets are typically too large to remain airborne for long periods and quickly sink to the bottom. Demonstration results show that the COVID-19 virus is primarily transmitted through respiratory droplets and contact. In this example, the inventors' primary concern was determining whether airborne mist particles could be captured by the air treatment system 3.

[0054] Please refer to Figure 12. Figure 12(a) is a graph showing the capture of phage sprayed into the air using a single air treatment device, a dual-unit air treatment device, and a triple-unit air treatment device. As a negative control, an uncharged air treatment device was used alone. The capture time was 30 minutes. Figure 12(b) is a graph showing the time relationship of the capture of phage sprayed into the air using a triple-unit air treatment device.

[0055] Figure 12(a) shows data comparing the phage capture efficiency when using only one of the air treatment devices 3A, 3B, and 3C, when two devices are connected in series, and when three devices are connected in series. The electrically charged air treatment device effectively captured the phages sprayed into the air. This result is thought to be due to the air treatment device generating ionic wind I, which is effective in drawing outside air into the air treatment device. In fact, the two-device and three-device air treatment devices were effective in drawing in larger volumes of air, i.e., more phage particles. In both experiments, 5 mL of phage solution (10 8 The phage trapping efficiency was measured using a double-layer agar plate. The mean and standard deviation shown in Figure 12(b) were calculated from five replicate experiments. The letters (a-d) in the graph indicate significant differences (p<0.05) according to Tukey's method.

[0056] The objective of this experiment was to confirm how long phage mist of the current size (1-10 μm) could remain suspended in the air of a sealed, unventilated cabinet. To this end, a time-course trapping assay was performed using triplicate air treatment devices 3A, 3B, and 3C. As shown in Figure 12(b), the number of captured phages was highest in the first capture operation and then decreased over time. No phages were obtained by the capture operation 35 minutes or more after spraying. These results suggest that, at least in the unventilated cabinet, mist particles containing phages remained suspended in the air.

[0057] This example demonstrates that air treatment devices 3A, 3B, and 3C have a strong ability to capture phage particles sprayed into the air. However, the suspended droplets evaporate within a few seconds depending on the temperature and relative humidity. Therefore, it is believed that pathogens ejected from the atomizer lose their suspended mist water both before and after the mist particles enter the electric field of the air treatment devices 3A, 3B, and 3C. Furthermore, the present system (TS) successfully sterilized the water containing the captured phages by collecting it in a water drain tank. All phages were killed by 30 minutes of ozone bubbling treatment. Thus, the present air treatment system (TS) can be applied as a practical approach to precipitate infectious respiratory droplets containing viral pathogens.

[0058] In this way, it has been preliminarily confirmed that the air treatment device can capture not only membranous phages such as φ6, but also non-membranous phages such as E. coli T7 phage and λ phage, as well as cells of gram-negative bacteria (E. coli) and gram-positive bacteria (Bacillus subtilis). Judging from these results, it is believed that the air treatment device can generate an abundance of negative ions that exceed the original surface charge, regardless of the state of the surface charge of the components to be captured.

[0059] While the preferred embodiments of the air treatment system and method of the present invention have been described above, it will be understood that various modifications can be made without departing from the spirit and scope of the invention. [Industrial Applicability]

[0060] The present invention is particularly effective in capturing infectious droplets in crowded or poorly ventilated areas. Furthermore, the device itself can be easily constructed using readily available materials and can be combined with various methods as needed to disinfect water containing pathogens. In other words, because of its low manufacturing cost and low power consumption, the device has broad industrial applicability, particularly in developing countries, as it can be easily used to prevent infection by airborne pathogens. In the examples, the φ6 phage was used as a model for the COVID-19 virus due to its morphological similarity and experimental safety, but any type of microorganism can be used to capture airborne or droplet-transmitted pathogens. Furthermore, because it can be recovered in solution while retaining its activity, its presence in the air can be quantified and continuously monitored. [Explanation of symbols]

[0061] 1 2 3 Air Treatment Equipment 10 20 30 Electrode plate 100 200 Base 101 201 301 Projection 102 holes 11 21 31 Collection tank 12 22 32 Voltage application device F conductive liquid Fw water Ion Wind L Ground wire X Collected component A. Air Ac treated air TS Total system including air treatment equipment OG Ozone Generator CT conductive double-sided adhesive tape GM Galvanometer EF electric field QF Square Hood

Claims

1. An air treatment device that captures components to be captured when air containing the components to be captured passes through the device, a collecting tank containing a conductive liquid grounded to earth and having an open top; and an electrode plate having a metal plate with a plurality of holes and a plurality of protrusions fixed thereto, the electrode plate being placed on an upper edge surface of the collecting tank so that the tips of the protrusions face the upper surface of the conductive liquid; When an electric charge is supplied to the protrusions to generate an electrostatic field, the conductive liquid contained in the collection tank is charged with an electric charge opposite to the electric charge supplied to the protrusions due to electrostatic induction, and an ionic wind is generated from the tip of the protrusions toward the upper surface of the conductive liquid, causing the components to be captured to be captured on the side of the conductive liquid.

2. 2. The air treatment device according to claim 1, wherein the conductive liquid is water, and when the components to be captured are water-soluble, the components dissolve in the water and are captured, and when the components to be captured are water-insoluble, the components are captured on the surface of the water.

3. 2. The air treatment device according to claim 1, wherein the conductive liquid is held in a liquid holding material and contained in the collection tank.

4. 2. The air treatment device according to claim 1, wherein the conductive liquid is in a gel state and is contained in the collection tank.

5. 2. The air treatment device according to claim 1, wherein the conductive liquid is aqueous, and if the components to be captured are water-soluble, the components are captured within the conductive liquid, and if the components to be captured are water-insoluble, the components are captured on the top surface of the conductive liquid.

6. 2. The air treatment device according to claim 1, wherein the conductive liquid is oily, and if the components to be captured are oil-soluble, the components dissolve in the conductive liquid and are captured, and if the components to be captured are oil-insoluble, the components are captured on the top surface of the conductive liquid.

7. 7. The air treatment device according to claim 1, wherein the distance between the tip of the protrusion and the upper surface of the conductive liquid varies in proportion to the voltage applied to the tip.

8. 8. An air treatment device according to claim 1, wherein said protrusion is a pointed tip.

9. 9. An air treatment device according to claim 1, wherein the components to be captured are pathogens, pesticides, cigarette smoke, carbon dioxide, ammonia, formaldehyde, acetaldehyde, as well as gases, aerosols, and flying particles contained in the air.

10. An air treatment method for capturing components to be captured when air containing the components to be captured passes through the air treatment device, comprising: An air treatment device comprising a collection tank containing a conductive liquid and having an open top, and an electrode plate having a metal plate with a plurality of holes and a plurality of protrusions fixed thereto, wherein the electrode plate is placed on an upper edge surface of the collection tank so that the tips of the protrusions face the top surface of the conductive liquid, When an electric charge is supplied to the protrusions to generate an electrostatic field, the conductive liquid contained in the collection tank is charged with an electric charge opposite to the electric charge supplied to the protrusions due to electrostatic induction, and an ionic wind is generated from the tips of the protrusions toward the upper surface of the conductive liquid, causing the components to be captured to be captured on the side of the conductive liquid.

11. The air treatment method according to claim 10, characterized in that the conductive liquid is aqueous, and if the components to be captured are water-soluble, the components are captured within the conductive liquid, and if the components to be captured are water-insoluble, the components are captured on the top surface of the conductive liquid.

12. The air treatment method described in claim 10, characterized in that the conductive liquid is oily, and if the components to be captured are oil-soluble, the components dissolve in the conductive liquid and are captured, and if the components to be captured are oil-insoluble, the components to be captured are captured on the upper surface of the conductive liquid.

13. 13. The air treatment method according to claim 10, wherein the components to be captured are pathogens, pesticides, cigarette smoke, carbon dioxide, ammonia, formaldehyde, acetaldehyde, as well as gases, aerosols, and flying particles contained in the air.

14. A method for continuously monitoring the components to be collected that have been recovered in the conductive solution using the air treatment method described in any one of claims 10 to 13, by sampling the conductive solution to quantify the amount present in a certain amount of air.

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