Air Purifier

Abstract

To provide an air purification device capable of reducing deleterious materials such as viruses and bacteria in a closed space such as indoor, and eliminating need of frequent ventilation.SOLUTION: An air purification device comprises: an action chamber 2 which has an applicator 20 and a microwave generator 3 installed in a vertically long hollow housing 1 open at both ends, and applies a microwave introduced from the microwave generator 3 to air introduced into the applicator 20 to reduce infectious structures and minute creatures included in the air; and a blower 5 which is installed in the vicinity of an end part of the hollow housing 1 and circulates air in a room through the action chamber 2. The blower 5 is controlled so that the air in an upper region of the room is sucked and circulated in a descending direction in the action chamber 2 upon a human presence detection of a human sensor 12. The blower 5 is also controlled so that air in a lower region of the room is sucked and circulated in an ascending direction in the action chamber 2 upon a human absence detection of the human sensor 12, thereby reducing infectious structures and minute creatures in the room air.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an air purification technology, and more particularly to an air purification device for eliminating infectious structures such as viruses and microorganisms such as bacteria present in indoor air to obtain a safe living environment. [Background technology]

[0002] As a means for removing harmful substances such as infectious structures such as viruses and various microorganisms such as bacteria present in the air, in addition to the use of disinfectants and germicides, a method using ions and radicals generated by streamer discharge (electrical streamer) is known (Patent Document 1). Also, a method for destroying bacteria and viruses by resonance absorption of high-energy electromagnetic waves has been proposed (Patent Document 2).

[0003] Furthermore, a method has been proposed in which electromagnetic waves (microwaves) are irradiated into the air in which pathogen-transmitting organisms (such as the Anopheles mosquito and the tsetse fly) are flying, and the proteins in the organisms are heated and destroyed, rendering them harmless (Patent Document 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-21319 A [Patent Document 2] JP 2000-245813 A [Patent Document 3] JP 2009-297008 A Summary of the Invention [Problem to be solved by the invention]

[0005] The air purifier described in Patent Document 1, which uses streamer discharge, is configured to generate high-speed electrons by high-voltage discharge to destroy and remove the DNA and RNA of bacteria, viruses, etc. suspended in the air. The electrode pair that generates the high-voltage discharge forms a discharge field that intersects with the air flow path, and when the airflow passes through this discharge area, bacteria, viruses, etc. contained in the air are destroyed.

[0006] In addition, the technology disclosed in Patent Document 2 involves irradiating bacteria or viruses with electromagnetic waves that are in tune with their natural vibrational frequency, causing them to resonantly absorb the waves and exceeding the resonance absorption capacity, thereby destroying and eliminating the tissues of the bacteria or viruses.

[0007] Patent Document 3 discloses a method and device for heating and killing Anopheles mosquitoes and Anopheles oryzae mosquitoes flying in the air by emitting electromagnetic waves (microwaves) of around 2 GHz to 10 GHz into the air at an output level that does not affect the human body.

[0008] None of the above-mentioned prior arts discloses any specific means for preventing the leakage of electromagnetic waves into the environment or the effects of electromagnetic waves on the human body, and the structures of these prior arts are complicated.

[0009] Furthermore, regarding the novel coronavirus (COVIT-19), which has recently become a major social issue, frequent ventilation is considered to be one of the measures that can be taken to prevent infection inside buildings and public transport vehicles (hereinafter referred to as indoors). However, frequent ventilation in cold seasons and in extremely hot environments must be considered an extremely passive response from the standpoints of keeping warm, avoiding heatstroke, and saving energy.

[0010] An object of the present invention is to provide an air purifying device that eliminates harmful substances such as viruses and bacteria in a closed space such as an indoor space, thereby eliminating the need for frequent ventilation. [Means for solving the problem]

[0011] In order to achieve the above object, the present invention has the following representative configurations. Note that, in order to clarify the present invention, the respective components are given the reference symbols used in the drawings of the embodiments described below, but the present invention is not limited to the configurations given these reference symbols.

[0012] The present invention provides an air purifying device for eliminating microorganisms such as viruses and bacteria, which are infectious structures, to obtain safe air by preventing infection, and has the following configuration:

[0013] The present invention is an air purification device for eliminating infectious structures and microorganisms present in indoor air, and comprises a vertically long hollow housing 1 with both ends open, and an action chamber 2 that is installed inside the hollow housing 1 and irradiates microwaves onto the air introduced into an applicator 20 equipped with a microwave generator 3, thereby eliminating the infectious structures and microorganisms contained in the air.

[0014] The device also has a blower 5 that is installed inside the hollow housing 1 near the end thereof to circulate indoor air through the working chamber 2, a human presence sensor 12 that detects the presence or absence of a person in the room, and a control circuit 4 that stores an operation control program for the device, including control for switching the direction of indoor air circulation by the blower 5 based on a detection signal from the human presence sensor 12. The control circuit also has a power supply circuit that generates the power required for the device.

[0015] The switching control program provided in the control circuit 4 is configured to control the operation of the blower 5 so that, based on the detection of the presence of a human being by the human presence sensor 12, it draws in air from the upper area of ​​the room (generally the area from halfway between the floor and the ceiling to the ceiling) and circulates it in a downward direction through the working chamber 2, and to control the operation of the blower 5 so that, based on the detection of the absence of a human being by the human presence sensor 12, it draws in air from the lower area of ​​the room (generally the area very close to the floor) and circulates it in an upward direction through the working chamber 2.

[0016] The peripheral wall of the hollow housing 1 has a microwave shielding function formed of a metal plate or the like that prevents microwaves from leaking to the outside. Metal plates 7 and 8 having a large number of fine holes are provided to cover the openings at the upper and lower ends of the hollow housing 1, respectively, to prevent microwaves from leaking from the action chamber 2 to the indoor space (external environment).

[0017] An operation panel 41 is provided on the outer wall of the hollow housing 1, and the control program and timer function stored in the control circuit 4 can be used to set the detection signal from the human sensor 12 and the switching of the indoor air flow direction by the blower 5 and the timing thereof.

[0018] The blower 5 may be a Coanda effect fan 50, a so-called propeller fan 60 including a turbofan, a sirocco fan 70, or any other suitable blower. Note that if the blower can reverse the direction of the airflow, a configuration in which only one blower is installed at the upper end or lower end of the hollow housing 1 may be adopted.

[0019] A base 10 is provided at the bottom of the hollow housing 1, and casters 11 are attached to the base 10 to make it movable, so that the installation location can be freely selected.

[0020] The applicator constituting the action chamber 2 is not limited to the empty box (oven) type described later in FIG. 2, but may be a type having a spiral path in which a wide metal plate is wound in one dimension as described later in FIG. 7, thereby ensuring a large contact time between the air flow and the microwaves.

[0021] The present invention is not limited to the above configurations and the configurations described in the embodiments below, and it goes without saying that various modifications are possible within the scope of the technical concept of the present invention. Effect of the Invention

[0022] The present invention provides an air purifying device that can be safely used in spaces with high air-conditioning volumes, such as office rooms, conference rooms, and residential rooms, as well as school classrooms, auditoriums, and gymnasiums. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic diagram illustrating the basic structure of an air purifying device according to the present invention. [Diagram 2] FIG. 2 is a schematic diagram illustrating an example of an applicator that constitutes the working chamber of FIG. [Diagram 3] FIG. 1 is a schematic diagram illustrating an embodiment 1 of an air purifying device according to the present invention. [Figure 4] FIG. 1 is a perspective view showing the appearance of an air purifying device according to a first embodiment of the present invention; [Diagram 5] FIG. 1 is a schematic diagram illustrating a second embodiment of an air purifying device according to the present invention. [Figure 6] FIG. 3 is a schematic diagram illustrating an air purifying device according to a third embodiment of the present invention. [Figure 7] FIG. 11 is a schematic diagram illustrating another example of an applicator that constitutes the working chamber of the air purifying device according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an air purifying device according to the present invention will be described in detail with reference to the accompanying drawings.

[0025] 1 is a schematic diagram illustrating the basic structure of an air purifier according to the present invention. This air purifier comprises a vertically long hollow housing 1 with both ends open, and an action chamber 2 that is installed inside the hollow housing 1 and that irradiates microwaves to the air introduced into an applicator 20 equipped with a microwave generator 3 to eliminate infectious structures and microorganisms contained in the air. Although the hollow housing 1 is shown as being cylindrical, it may be a tubular body with an elliptical or polygonal cross section.

[0026] The microwave generator 3 preferably uses a power semiconductor (Gunn diode, IMPATT diode, GaAs field effect transistor, etc.) oscillator, but may also be a conventional magnetron. The oscillation output of the microwave generator 3 is introduced to the applicator 20 through a transmission line (waveguide, etc.) 32. Reference numeral 31 denotes a cooling fin.

[0027] The device also includes a blower 5 that is installed inside and near the end of the hollow housing 1 to circulate the indoor air to be purified through the working chamber 2, and at least one human presence sensor 12 that detects the presence or absence of people in the room.The device also includes a control circuit 4 that stores an operation control program for the device, including control of switching the direction of indoor air circulation (direction A, direction B) by the blower 5 based on a detection signal from the human presence sensor 12 and operation timing.

[0028] The operation control program for switching the air flow direction provided in the control circuit 4 controls the blower 5 based on the presence of a human being detected by the human presence sensor 12 so as to suck in air from the upper region of the room (generally the region from about halfway between the floor and the ceiling to the ceiling) and circulate it in a downward direction (arrow A) within the working chamber 2. Also, based on the absence of a human being detected by the human presence sensor 12, the blower 5 is configured to control the blower 5 so as to suck in air from the lower region of the room (generally the knee-length region very close to the floor) and circulate it in an upward direction (arrow B) within the working chamber 2.

[0029] The peripheral wall of the hollow housing 1 has a microwave shielding ability to prevent microwaves from leaking to the outside. Specifically, metal plates such as aluminum (aluminum alloys) and iron plates (iron alloys including stainless steel) are used. Also, shielding plates 7 and 8 made of metal plates with many fine holes are provided to cover the openings at the upper and lower ends of the hollow housing 1, respectively, to prevent microwaves from leaking from the working chamber 2 to the indoor space (external environment). An opening 9 is provided at the bottom of the hollow housing 1 for air to flow in and out.

[0030] As mentioned above, the arrow A in the figure indicates the direction in which the fan blows air from the upper floor to the floor, and the arrow B indicates the direction in which the fan blows air from the floor to the upper floor. In the figure, the fan is installed above and below, but only one fan can be used as long as the blowing directions can be reversed.

[0031] The size of the pores in the shielding plates 7 and 8 is less than the wavelength of the microwaves and is sufficiently small (specifically, about half the microwave wavelength), allowing air to pass through while reducing the leakage of the injected microwaves to below a safe value.

[0032] An operation panel 41 is provided on the outer wall of the hollow housing 1. Using a control program and a timer function stored in the control circuit 4, the operation panel 41 sets the detection signal from the motion sensor 12 and the switching and timing of the indoor air flow direction by the blower 5. Standard initial settings are performed at the time of manufacture, but after the unit is installed by a user, the user can also change the settings.

[0033] FIG. 2 is a schematic diagram illustrating an example of an applicator constituting the working chamber in FIG. 1, in which (a) is a vertical cross-sectional view showing the internal configuration, and (b) is a schematic diagram showing the stirrer 21 inside with the upper and lower shields 22, 23 removed. The container of this applicator 20 is a hollow cylinder that matches the shape of the hollow housing, but it may be a box or other shape, and is formed from a metal plate such as an aluminum (or aluminum alloy) plate or an iron alloy plate (including stainless steel plate).

[0034] Shields 22, 23 are attached to the upper and lower open ends of the applicator 20. These shields have tiny holes formed therein, through which air flows. Since the air flow does not need to be fast, the holes are unlikely to cause significant resistance to the air flow. These holes are designed to keep the leakage of microwaves C injected from the microwave generator 3 through the transmission line 32 from the applicator 20 to the outside below the regulated value.

[0035] A stirrer 21 is installed in the applicator 20. This stirrer 21 has the function of evenly reflecting and scattering the microwaves C, which are injected from the microwave generator 3 through the transmission line 32 and the microwave inlet, inside the applicator 20, and increasing the chance of the microwaves coming into contact with the incoming air (probability of encountering viruses or bacteria). This improves the efficiency of depletion of infectious structures and microorganisms contained in the air. Note that the inner wall surface of the applicator 20 may also be formed with irregularities to diffusely reflect the microwaves.

[0036] By circulating indoor air through an air purifying device having this configuration, infectious structures and microorganisms contained in the air can be eliminated, providing a safe living space.

[0037] Next, a specific example of the air purifying device according to the present invention will be described with reference to the drawings of the embodiment. EXAMPLES

[0038] Fig. 3 is a schematic diagram for explaining a first embodiment of an air purifying device according to the present invention, and Fig. 4 is a perspective view showing the appearance of the air purifying device shown in Fig. 3. The same reference numerals as in Fig. 1 correspond to the same functional parts. Note that the hollow housing 1 is configured such that the metallic shield 1b is covered with a decorative exterior 1a, but the decorative exterior 1a can be omitted. A hopper 6 is attached to the top of the hollow housing 1, and an upper shield 7 having pores 71 formed therein is placed on top of the hopper 6. Note that the lower shield 8 (Fig. 3), which is not shown in Fig. 4, has the same structure as the upper shield 7.

[0039] In this embodiment, a blower device utilizing the Coanda effect (hereinafter, Coanda effect fan) 50 is used as the blower 5. This Coanda effect fan 50 utilizes the effect that a jet of viscous fluid is attracted to a nearby wall surface (i.e., the Coanda effect). A relatively large amount of air can be blown with a small initial air volume.

[0040] In the first mode, in which the human presence sensor 12 (two human presence sensors 12 are installed in this embodiment to widen the detection range) detects a human and sends air from the upper layer of the room to the device, the Coanda effect fan 50 installed on the upper side of the hollow housing 1 has a wind generator 52 provided in a part of the annular body that has a ring-shaped slit 51 formed along the inner edge near the downstream outlet of the air flow inside the hollow annular body, as shown in Figures 3 and 4. A small propeller fan or turbo fan is used as the wind generator.

[0041] The Coanda effect fan 50 is formed so that the slits 51 from which the air is ejected face the downstream side of the airflow. The air from the wind generator 52 is ejected from the slits 51 toward the axial downward side (toward the working chamber) in Fig. 3, thereby drawing in the air around the hollow annular body and blowing it toward the working chamber 2. Therefore, this Coanda effect fan cannot blow air in the opposite direction unless the direction of the slits is changed.

[0042] In this embodiment, in the first mode, air is taken in from above in Fig. 3 and introduced into the working chamber 2 through the duct 21. Air is ejected as a jet stream from the annular slit 51 formed at the downstream outlet of the air flow inside the hollow annular body. This jet stream entrains the air around the hollow annular body (including the inner region of the hollow annular body) to become a large amount of air flow, which is introduced into the working chamber 2 through the upper duct 21.

[0043] The airflow introduced into the working chamber 2 is depleted of infectious structures and microorganisms as it passes through the interior of the applicator 20 as shown in FIG. 2, and is then exhausted as purified air through the lower duct 21, through a similar Coanda effect fan 50 (which is not operational) installed on the underside of the hollow housing 1, and through the opening 9 to the floor area of ​​the room.

[0044] As described above, in the first mode, the other Coanda effect fan 50 installed on the lower side of the hollow housing 1 stops rotating, and the air exhausted from the working chamber 2 passes through the lower shield 8 and is discharged toward the floor from the opening 9. By repeating this circulation of the airflow, viruses, bacteria, etc. contained in the indoor air are eliminated.

[0045] As an option, a base 10 can be provided at the bottom of the hollow housing 1, and casters 11 can be attached to this base 10 to make it mobile, allowing the installation location to be easily moved. Also, a large-capacity battery 14 such as a lithium-ion battery can be stored in the base 10 so that the device can be operated without relying solely on commercial power.

[0046] The second mode should preferably start when the motion sensor 12 detects no human beings after a certain time has elapsed when the movement of air in the room has subsided and residual viruses, etc. (microscopic water vesicles and microscopic dust particles with viruses, etc. attached) have settled to the floor side. This timing can be set from the operation panel 41. For example, if the closing time for a work room such as an office is 6:00 p.m., the operating time of the second mode and the amount of circulating air can be set according to the size of the room (volume of non-treated space), such as 10 hours from 2 hours after that until 6:00 a.m.

[0047] With the configuration of this embodiment, when people are present in the room, the air that is mostly used for breathing and talking in the upper area of ​​the room is circulated so that the viruses and bacteria contained therein are preferentially reduced and purified, and then released to the floor side of the room. Most of the viruses and bacteria remaining in the air released to the floor side are reduced by repeated processing in the second mode. This reduces the risk of infection from infectious structures (viruses) and microorganisms (bacteria, etc.) contained in the air, providing a comfortable living space (office space). EXAMPLES

[0048] 5 is a schematic diagram for explaining a second embodiment of the air purifying device according to the present invention, in which the same reference numerals as those in the previous embodiment correspond to the same functional parts. In this embodiment, a so-called propeller fan 60 is used as the blower 5. The remaining configuration is the same as that of the first embodiment.

[0049] Since the propeller fan 60 can easily rotate in the reverse direction in both DC and AC drives, it is possible to use the propeller fan 60 as the upper blower and eliminate the need for a lower blower. It is also possible to do the reverse, and switch the rotation direction according to the air flow direction shown by the arrows A and B described in FIG. 1 above.

[0050] Even with the configuration of this embodiment, when people are present in the room, the intermediate air at the upper part of the room, i.e. the air volume in which people mainly breathe and talk is suspended, is depleted of viruses and bacteria contained in the intermediate air, and the purified air is circulated to be discharged to the floor side of the room, thereby reducing the risk of infection from infectious structures and microorganisms contained in the air, and providing a comfortable living space (work space). Furthermore, by using a single blower for this air circulation, the device can be made lighter and less expensive. EXAMPLES

[0051] 6 is a schematic diagram for explaining a third embodiment of an air purifying device according to the present invention. The same reference numerals as those in the above-mentioned embodiments correspond to the same functional parts. In this embodiment, a sirocco fan 70 is used as the blower 5. The remaining configuration is the same as that of the above-mentioned embodiments.

[0052] In this embodiment, the sirocco fan 70 is provided at the upper and lower ends of the hollow housing 1. The sirocco fan 70 cannot blow air in the reverse direction due to its structure, as with the Coanda effect fan 50 described in the first embodiment. Therefore, in the first mode, which starts when the motion sensor 12 detects a human being, the sirocco fan 70 installed at the upper end draws air from the upper shield 7 through the air hopper 6 to the rotating shaft side and discharges it as an air flow in the circumferential direction (horizontal direction) of the rotor blades. This horizontal discharged air flow is collected in the duct 21 and deflected in the axial direction (vertical direction of the device) and introduced into the working chamber 2.

[0053] At this time, the rotation of the sirocco fan 70 provided on the lower side of the hollow housing 1 is stopped. The air discharged from the working chamber 2 passes around the sirocco fan, between the blades, and is discharged from the rotating shaft through the lower shield 8 and from the opening 9 toward the floor.

[0054] In the second mode, which occurs when the motion sensor 12 detects no human presence, the sirocco fan 70 on the lower side of the hollow housing 1 operates to suck up air near the floor and send it to the working chamber 2. The air that has been purified in the working chamber 2 passes through the upper sirocco fan 70, which is stopped, and is released into the room from the upper shield 7.

[0055] This second mode is preferably started after a certain time has elapsed when the movement of air in the room has subsided and residual viruses and the like have settled on the floor side. This timing can be set from the operation panel 41. For example, if the closing time for a work room such as an office is 6:00 PM, the operating time for the second mode can be set according to the size of the room (volume of non-treated space), such as 10 hours from 2 hours after that until 6:00 AM. At this time, the amount of air circulated per unit time can also be set.

[0056] With the configuration of this embodiment, when people are present in the room, the air that is primarily used for breathing and talking is circulated so that it is purified and the viruses and bacteria contained therein are preferentially reduced, and then released to the floor side of the room.

[0057] This reduces the risk of infection from infectious structures (viruses) and microorganisms (bacteria, etc.) contained in the air, providing a comfortable living space (office space). The Sirocco fan 70 is characterized by its relatively quiet operation compared to various types of blowers, making it ideal for offices and other places where a quiet environment is required.

[0058] Above, embodiments having various representative blowers have been described. The blower 5 is not limited to the Coanda effect fan 50, the propeller fan 60, and the sirocco fan 70, but may be any other suitable blower such as a turbo fan depending on the processing capacity. Note that if the blower can reverse the direction of the airflow, only one blower may be installed at the top or bottom of the hollow housing 1.

[0059] As mentioned above, in addition to making the device of the present invention a stationary type, it is also possible to provide a base 10 at the bottom of the hollow housing 1 and attach a movable mechanism such as casters 11 to this base 10 so that the installation location can be freely selected.

[0060] Fig. 7 is a schematic diagram for explaining another configuration of the action chamber, in which the action chamber 2 is a spiral applicator body 20a with a spiral path formed by one-dimensionally spiraling a wide metal plate instead of the applicator 20 installed inside an empty box (oven) as shown in Fig. 2. The spiral path can increase the contact opportunity between the airflow (arrow A) flowing in from the upper duct 21 in the first mode and the microwave C generated by the microwave generator and entering from the inlet 33. As a result, the effect of attenuating viruses and bacteria mixed in the air is increased.

[0061] The same applies to the airflow (arrow B) that flows in from the lower duct 21 to the side and flows out from the upper duct to the upper side in the second mode when the motion sensor detects the absence of a human being. Reference numerals 20b, 20b denote side covers that suppress leakage of airflow from the spiral applicator body 20a. The blower may be of any of the above-mentioned embodiments or any other appropriate type.

[0062] The following will supplement the above-described embodiments and other descriptions. The holes in the shield plates 7, 8 installed near the upper and lower ends of the hollow housing 1 can be of any shape as long as they are large enough to prevent microwaves from passing through, but are usually circular. The diameter of the holes is about half the wavelength of the microwaves. If the microwave frequency is 2.45 GHz, the wavelength is 0.012 m, so the diameter is about half of that, specifically 0.005 to 0.006 m (5 mm to 6 mm). If a necessary air flow rate is ensured and other effective electromagnetic shielding means are used (for example, a wide metal band is provided around the upper shield plate 7), the diameter of the openings 21 can be larger than the above.

[0063] Although a magnetron oscillator may be used as the microwave generator 5, the use of a power semiconductor oscillator contributes to making the device smaller, lighter, and less power-consuming. Since the microwave power according to the present invention is effective even with a few watts, it is preferable to use a power semiconductor oscillator.

[0064] By giving the oven-type wall described in FIG. 2 or the inner wall of the spiral cylinder 1 shown in FIG. 7 a shape that diffuses microwaves or by providing a deflector plate 11 for slowing down the passing speed of the air sent in by the blower 3, the contact time between the microwaves and viruses and bacteria in the air can be increased, thereby improving efficiency. [Industrial Applicability]

[0065] The air purifying device of the present invention can be installed as a means of eradicating harmful bacteria and the like, including prevalent viruses, by introducing it into the interior of buildings, regardless of whether they are small or large, such as offices, school classrooms, living rooms in homes, medical facilities, closed spaces such as event venues, karaoke, restaurants, other entertainment facilities, and public transportation vehicles such as trains and buses. When installing it inside a train or bus, the hollow housing can be placed on the ceiling with its lengthwise direction horizontal. In addition, the device of the present invention can be built into the ceiling of the vehicle or incorporated into the ventilation system to avoid exposure to the interior of the vehicle. [Explanation of symbols]

[0066] 1. Hollow housing 2. Working chamber 3. Microwave generator 4. Control circuit 41 Operation panel 5. Blower 50···Coanda effect fan 60···Propeller fan 70···Sirocco fan 7. Upper shield 8. Lower shield 9...Aperture 10. Base 11. Caster 12. Motion sensor 14. Battery

Claims

1. An air purification device for eliminating infectious structures and microorganisms present in indoor air, comprising: A vertically long hollow housing with both ends open; a microwave action chamber configured to irradiate the air introduced into the applicator with microwaves introduced from the microwave generator, the microwave action chamber being configured to destroy the infectious structures and microorganisms contained in the air, the microwave action chamber being configured to be ... a blower disposed inside the hollow housing near an end thereof for circulating air in the room through the microwave action chamber; A human presence sensor that detects the presence or absence of a human in the room; a control circuit storing an operation control program for the device, the operation control program including switching control of the flow direction of the indoor air by the blower based on a detection signal of the human presence sensor; An air purifying device characterized in that the operational control program provided in the control circuit controls the blower to draw in air from the upper area of ​​the room and circulate it in a downward direction through the microwave action chamber based on the presence of a human being detected by the human presence sensor, and controls the blower to draw in air from the lower area of ​​the room and circulate it in an upward direction through the microwave action chamber based on the absence of a human being detected by the human presence sensor.

2. The air purifying device according to claim 1, characterized in that the peripheral wall of the hollow housing has a microwave shielding ability to prevent microwaves from leaking to the outside, and is constructed by covering each of the upper and lower ends thereof with a shield made of a metal plate having a large number of fine holes to prevent microwaves from leaking from the microwave action chamber into the indoor space.

3. The air purifying device according to claim 1 or 2, characterized in that it has an operation panel on the outer wall of the hollow housing, and uses a control program and a timer function stored in the control circuit to set the detection signal of the human sensor, the switching of the flow direction of the indoor air by the blower, and the start timing of operation.

4. 2. The air purifier according to claim 1, wherein the blower is a Coanda effect fan in which a jet of viscous fluid is attracted to an adjacent wall surface, and the blower is installed so that a slit from which air is ejected faces downstream of the air flow and ejects air toward the microwave action chamber.

5. 2. The air purifying device according to claim 1, wherein the blower is a propeller fan.

6. 2. The air purifying device according to claim 1, wherein the blower is a sirocco fan.

7. 2. The air purifying device according to claim 1, further comprising a base at a bottom of said hollow housing, said base being fitted with casters.

Images