Air purification system and protective clothing

Abstract

An air purification system (1) comprises: a wire electrode (20) with which electromagnetic resonance is generated; an electric field probe (40) that measures the strength of an electric field; and a control unit (70) that controls power supplied to the wire electrode (20). The control unit (70) manipulates the frequency of the power supplied to the wire electrode (20) and the position in which the power is supplied to the wire electrode (20), and performs control to maximize the output value of a signal indicating the electric field strength. Feedback is controlled so that the amount of ozone is always constant, by monitoring the amount of ozone generated and manipulating the amplitude and the modulation of the supplied power, so that ozone for breaking down a virus is generated but harmful nitrogen oxide is not generated as a result of supplying, to gas molecules contained in influent gas, energy that is at least the dissociation energy of oxygen molecules and no greater than the dissociation energy of nitrogen molecules.

Description

Air purification systems and protective clothing

[0001] The present disclosure relates to an air purification system and protective clothing using the air purification system.

[0002] Conventionally, a treatment apparatus has been proposed that utilizes high-voltage plasma at atmospheric pressure to oxidize NO contained in exhaust gas emitted from an internal combustion engine such as an internal combustion engine.

[0003] When using a voltage conversion transformer that is commonly used in the low frequency band of 10 MHz or less to generate high-voltage plasma, it is necessary to reduce the inductance (reactance) at high frequencies of 100 MHz or more. This requires reducing the number of turns and the size of the coil, which in turn requires a smaller diameter of the coil used as an electric wire, resulting in the problem that a large amount of power cannot be input.

[0004] On the other hand, if the voltage is increased without the voltage conversion, while the characteristic impedance is kept low, for example, at 50 Ω, then, for example, 10 kW (=1000 V) is required for a voltage of 1000 V. ２ In practice, it is difficult to provide a power supply device that can supply such a large amount of power.

[0005] Therefore, Non-Patent Document 1 below proposes a plasma reactor that generates plasma between electrodes by applying a high voltage pulse with a peak voltage of 5000 to 10000 V at a frequency of several kHz to the electrodes in order to oxidize NO in exhaust gas emitted from an internal combustion engine such as an internal combustion engine.

[0006] Complete removal technology of nitrogen oxides using non-equilibrium plasma and chemical reaction process (performance comparison of conventional and barrier type plasma reactors)," Transactions of the Japan Society of Mechanical Engineers, Vol. 66-646B, pp. 1501-1506 (2000)

[0007] However, conventional air purification systems using plasma reactors have problems such as insufficient power supply to the electrodes due to impedance mismatch of the applied pulse voltage signal. Furthermore, with high-voltage pulses of several kHz, the time between high-voltage pulses is longer than the discharge time of the high-voltage pulse. At this time, electrons ionized from the gas recombine, requiring a large amount of energy to ionize the electrons each time a high-voltage pulse is applied, resulting in a device with low power efficiency. Therefore, even if plasma is generated, the amount of bacteria, viruses, etc. in the air that can be decomposed by the plasma is low compared to the input power.

[0008] Furthermore, in conventional air purification systems, it is difficult to reduce not only the dissociation of oxygen molecules caused by the strong electric field corresponding to the peak value of the pulse, but also the dissociation of nitrogen molecules, and the nitrogen oxides generated by the dissociation of nitrogen molecules. Furthermore, although ozone is generated, it is also difficult with conventional technology to prevent the generation of nitrogen oxides.

[0009] Therefore, in order to solve the above problems, the present disclosure aims to provide an air purification system and protective clothing that can decompose bacteria, viruses, etc. in the air by efficiently generating plasma while reducing input power compared to conventional systems.

[0010] In order to achieve the above object, an air purification system according to one aspect of the present disclosure is an air purification system that generates plasma using voltage, and includes: a first electrode that generates electromagnetic resonance when power is supplied; a second electrode that is spaced apart from the first electrode and is arranged to surround the first electrode; a power supply unit that supplies power to the first electrode; an electric field probe that measures the strength of the electric field between the first electrode and the second electrode; and a control unit that controls the power supplied to the first electrode, wherein the control unit operates the frequency of the power supplied to the first electrode and the position at which power is supplied to the first electrode, and controls the output value of a signal indicating the strength of the electric field measured by the electric field probe to be maximized.

[0011] Furthermore, the air purification system incorporates a detector that monitors the amount of ozone and nitrogen oxides generated. Although oxygen molecules are dissociated by the plasma to generate ozone, this air purification system can control the electric field applied to the plasma by changing the AC power, frequency, and power supply point, with the amount of ozone and nitrogen oxides generated set as target values, so that energy is input to the gas molecules that minimizes the generation of nitrogen oxides without dissociating nitrogen molecules.

[0012] In addition, in order to achieve the above-mentioned object, protective clothing according to one embodiment of the present disclosure comprises an air purification system and a covering body that is equipped with the air purification system and covers the surface of a person's body, and the air purification system purifies air inhaled from the outside and supplies the purified air into the covering body.

[0013] These comprehensive or specific aspects may be realized in an unmanned aerial vehicle, a storage device, one or more thruster devices, a system, a method, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM, or in any combination thereof.

[0014] According to the present disclosure, by efficiently generating plasma while reducing input power compared to conventional techniques, bacteria, viruses, and the like in the air can be decomposed.

[0015] FIG. 1 is a schematic diagram showing an air purification system according to a first embodiment. FIG. 2 is a schematic diagram showing the flow of air taken into the air purification system according to the first embodiment and changes in the feed point at which the power supply unit supplies power to the linear electrode. FIG. 3 is a schematic diagram showing changes in the length of a resonator in the air purification system according to the first embodiment. FIG. 4 is a schematic diagram showing how viruses are decomposed in a plasma generation region of the air purification system according to the first embodiment. FIG. 5 is a schematic diagram showing the flow of air taken into an air purification system according to a modified example of the first embodiment and changes in the feed point at which the power supply unit supplies power to the linear electrode. FIG. 6 is a block diagram showing an air purification system according to a second embodiment, which includes a flow control valve with a flow meter, etc. FIG. 7 is a schematic diagram showing a main body of the air purification system according to the second embodiment. FIG. 8 is a block diagram showing an air purification system according to a first modified example of the second embodiment, which includes a second filter unit, a heater unit, a second detector, a first filter unit, a first detector, piping, etc. FIG. 9 is a block diagram showing an air purification system according to a second modification of the second embodiment, the air purification system including a second filter unit, a heater unit, a second detector, piping, a first filter unit, and a first detector, and the second detector is provided on the piping. FIG. 10 is a block diagram showing an air purification system according to a third modification of the second embodiment, the air purification system including a second filter unit, a heater unit, and a first detector, and using a main body 1a having a control unit and the like. FIG. 11 is a block diagram showing an air purification system according to a fourth modification of the second embodiment, the air purification system including a second filter unit, a heater unit, and a first detector. FIG. 12 is a block diagram showing an air purification system according to a fifth modification of the second embodiment, the air purification system including a second filter unit and a first detector. FIG. 13 is a block diagram showing an air purification system according to a sixth modification of the second embodiment, the air purification system including a first detector. FIG. 14 is a front view of a protective suit according to the third embodiment, and a schematic diagram showing a display unit of the protective suit. FIG. 15 is a side view showing the protective suit according to the third embodiment, as viewed from the side. FIG. 16 is a front view showing how the air purification system mounted on the protective clothing according to the third embodiment sucks in viruses and the like along with the air.FIG. 17 is a cross-sectional view taken along line XVI-XVI in FIG. 16, showing the air purification system installed in the protective clothing according to the third embodiment.

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Each of the embodiments described below shows a specific example of the present invention. Therefore, the numerical values, shapes, materials, components, component arrangements, connection forms, steps, and step sequences shown in the following embodiments are merely examples and are not intended to limit the present invention. Therefore, among the components in the following embodiments, components not recited in the independent claims will be described as optional components.

[0017] It should be noted that each drawing is a schematic diagram and is not necessarily an exact illustration. In each drawing, the same reference numerals are used to denote substantially the same components, and redundant explanations may be omitted or simplified.

[0018] Furthermore, in the following embodiments, expressions such as "approximately **" are used. For example, "approximately central" does not only mean that the part is exactly central, but also means that the part is substantially central, i.e., includes an error of, for example, a few percent. Furthermore, "approximately central" means that the part is central within the range in which the effects of the present disclosure can be achieved. The same applies to other expressions using "approximately."

[0019] An air purification system and protective clothing according to an embodiment of the present disclosure will be described below.

[0020] (Embodiment 1) <Configuration: Air Purification System 1> The configuration of an air purification system 1 in this embodiment will be described.

[0021] Fig. 1 is a schematic diagram showing an air purification system 1 according to embodiment 1. Fig. 2 is a schematic diagram showing the flow of air drawn into the air purification system 1 according to embodiment 1 and changes in the power supply point F at which the power supply unit 30 supplies power to the linear electrode 20.

[0022] As shown in Figures 1 and 2, the air purification system 1 is an air purifier that uses a high-voltage plasma generator that can generate high-frequency plasma (hereinafter simply referred to as plasma) using a high voltage in a high-frequency band to decompose, i.e., kill and remove, bacteria, viruses, and the like in the air. In this embodiment, the air purification system 1 generates plasma using a high voltage modulated from a carrier wave of 100 MHz to 10 GHz. Note that the high voltage is, for example, a voltage of about 100 V or more. The high voltage in this embodiment is 10 ２ ~10 ５ It may also be V.

[0023] The high-frequency band is a frequency of approximately 100 MHz or higher. The high-frequency band in this embodiment may be 100 MHz or higher and 10 GHz. The plasma in this embodiment is atmospheric pressure plasma generated in atmospheric air at normal pressure. The air purification system 1 can also decompose and remove fine particles such as dust, pollen, mites, and smoke floating in the air.

[0024] The air purification system 1 comprises a first housing 10, a linear electrode 20, a power supply unit 30, an electric field probe 40, a second amplifier 41, a detector 42, a voltage converter 35, an actuator 36, a control unit 70, a duct 17, a second housing 50, a filter 60, and a fan 51.

[0025] The first housing 10 forms (defines) a long space 10a that accommodates the linear electrode 20 while being spaced apart from the linear electrode 20. The first housing 10 is grounded and therefore functions as a ground electrode. The first housing 10 is arranged to surround the linear electrode 20 to accommodate the linear electrode 20. A support 16a for connecting the linear electrode 20 is arranged and fixed in the space 10a inside the first housing 10. The support 16a is a support member that separates the inner wall surface of the first housing 10 from the linear electrode 20 and supports the linear electrode 20 in a predetermined position. The support 16a is made of a material such as polytetrafluoroethylene.

[0026] The first housing 10 is made of a highly conductive conductor material, such as silver, copper, aluminum, etc. The first housing 10 is an example of a second electrode.

[0027] The first housing 10 accommodates the linear electrode 20 and is elongated in the same direction as the length of the linear electrode 20. In the present embodiment, the first housing 10 has a shape corresponding to the shape of the linear electrode 20, for example, a cylindrical shape, but the shape of the first housing 10 is not particularly limited.

[0028] The first housing 10 is also formed with an inlet 12a for drawing in air and an air vent 12b for discharging the air drawn in from the inlet 12a to a duct 17. The inlet 12a is formed at one end of the first housing 10 in the longitudinal direction, and the air vent 12b is formed at the other end of the first housing 10 in the longitudinal direction. Air and the like present outside the first housing 10 is drawn in through the inlet 12a and passes through the air vent 12b. The duct 17 is connected to the air vent 12b, and the air that has passed through the inlet 12a and flowed through the space 10a of the first housing 10 passes through the air vent 12b and flows into the duct 17.

[0029] The first housing 10 also has a mesh-like frame 13. The frame 13 is provided at the suction port 12a and covers the opening of the suction port 12a.

[0030] The linear electrode 20 is an elongated electrode that is long in a predetermined direction. The linear electrode 20 is housed in the first housing 10 and is provided in a state spaced apart from the first housing 10. Specifically, the linear electrode 20 is connected to the support 16a so as to be spaced apart from the inner wall surface of the first housing 10, and is arranged in a predetermined orientation along the length direction of the first housing 10 and fixed to the first housing 10 via the support 16a.

[0031] The linear electrode 20 is made of a highly conductive conductive material, such as silver, copper, or aluminum. The linear electrode 20 is an example of a first electrode. The first electrode may be a plate-shaped electrode and is not limited to the linear electrode 20.

[0032] As shown in Fig. 2, modulated or unmodulated AC power supplied from the power supply unit 30 is applied to a feed point F of the linear electrode 20. The feed point F is located approximately in the center of the linear electrode 20 in the longitudinal direction, and is the point to which the modulated or unmodulated AC power supplied from the power supply unit 30 is applied. The feed point F is displaced a predetermined distance along the longitudinal direction of the linear electrode 20 from a position approximately halfway along the longitudinal direction of the linear electrode 20, depending on the output value (e.g., output voltage) of a signal indicating the electric field strength measured by the electric field probe 40. The length of the linear electrode 20 is the sum of the length of the linear electrode 20 itself and the lengths of the first dielectric 22 and the second dielectric 23 along the longitudinal direction of the linear electrode 20.

[0033] A first dielectric 22 and a second dielectric 23 are provided at one end of the linear electrode 20 (the end on the inlet 12a side). The first dielectric 22 and the second dielectric 23 are provided on the linear electrode 20 so that the one end of the linear electrode 20 is not exposed. The first dielectric 22 is a highly heat-resistant dielectric material that is arranged around the linear electrode 20 at one end of the linear electrode 20. The second dielectric 23 is a highly heat-resistant dielectric material that is arranged on the end surface of the one end of the linear electrode 20. Each of the first dielectric 22 and the second dielectric 23 is, for example, a ceramic such as quartz glass or alumina. In this embodiment, the first dielectric 22 is synthetic quartz, and the second dielectric 23 is alumina.

[0034] The linear electrode 20 generates resonance within the first housing 10 when AC power is supplied from the power supply unit 30. The linear electrode 20 receives AC power so as to generate resonance with maximum efficiency.

[0035] 3 is a schematic diagram showing the change in half wavelength during resonance in the air purification system 1 according to embodiment 1. The half wavelength during resonance within the space 10a of the first housing 10 represents the sum of the length of the linear electrode 20 in the longitudinal direction and the length of plasma generated in the plasma generation region P between one end of the linear electrode 20 and the inlet 12a of the first housing 10 (the length parallel to the longitudinal direction of the linear electrode 20). FIG. 3a shows a state in which no plasma is generated in the plasma generation region P. When the electromagnetic wave resonates on the linear electrode 20, the half wavelength of the electromagnetic wave is the length of the linear electrode 20 in the longitudinal direction, as shown by the dashed line. In other words, when the electromagnetic wave resonates on the linear electrode 20, the length of the half wavelength of the electromagnetic wave is λ / 2, and the length of the linear electrode 20 is L, then λ / 2 = L. Next, Fig. 3b shows the state where plasma begins to be generated in the plasma generation region P, and as shown by the dashed line, the half wavelength of the electromagnetic wave when resonance occurs is the sum of the length of the linear electrode 20 in the longitudinal direction and the length of the plasma. In other words, when the length of the plasma is d (variable), λ / 2 = L + d. Next, Fig. 3c shows the state where the size of the plasma in the plasma generation region P has reached its maximum, and as shown by the dashed line, the half wavelength of the electromagnetic wave when resonance occurs.

[0036] In this embodiment, the length of the linear electrode 20 is set so that plasma is effectively generated in the plasma generation region P in the frequency band of 100 MHz to 10 GHz.

[0037] The plasma generation region P is the region between one end of the linear electrode 20 and the opening surface of the inlet 12a, and is the region of the space 10a of the first housing 10 for generating plasma. In the plasma generation region P, a first shortest distance between one end of the linear electrode 20 and the opening surface of the inlet 12a is shorter than a second shortest distance between the other end of the linear electrode 20 and the opening surface of the vent 12b. By making the first shortest distance shorter than the second shortest distance, plasma is effectively generated in the plasma generation region P. When viewed along the length of the first housing 10, the plasma generation region P overlaps with and covers the opening surface of the inlet 12a. In the plasma generation region P, the size of the generated plasma and the projected area facing the opening surface change depending on the AC power supplied to the linear electrode 20.

[0038] 1 and 2 , under the control of the control unit 70, the power supply unit 30 receives a modulated or unmodulated AC current output from a variable frequency oscillator+modulator 31 via a first amplifier 32, thereby supplying the modulated or unmodulated AC current to a feed point F of the linear electrode 20. The power supply unit 30 includes the variable frequency oscillator+modulator 31, a first amplifier 32, a feed terminal 33, and a feed line 34.

[0039] The variable frequency oscillator+modulator 31 functions as both a voltage-controlled oscillator and a modulator, supplying modulated AC power or unmodulated AC current to the feed point F of the linear electrode 20 via the first amplifier 32. Specifically, the variable frequency oscillator+modulator 31 is controlled by the control unit 70 so that the output value of the signal measured by the electric field probe 40 is maximized (or local maximum), thereby controlling the frequency of the AC power supplied to the linear electrode 20. In other words, the variable frequency oscillator+modulator 31 is controlled by the control unit 70 so that the phase of the current (or voltage) when the AC power amplified by the first amplifier 32 is supplied to the feed point F becomes the same phase (synchronized) as the phase of the current during resonance occurring in the space 10a of the first housing 10. The variable frequency oscillator+modulator outputs an AC current to the first amplifier 32, the phases of which are controlled to be synchronized with each other.

[0040] The first amplifier 32 amplifies the AC power output by the variable frequency oscillator+modulator 31 and supplies the amplified AC power to a feeding point F via a feeding line 34. The first amplifier 32 amplifies the AC power by a predetermined factor, but the amount of amplification may be set appropriately.

[0041] The power supply terminal 33 is a connection terminal for supplying the AC power amplified by the first amplifier 32 to the power supply point F of the linear electrode 20. The power supply terminal 33 is fixed to the first housing 10 so that the power supply line 34 is electrically connected to the power supply point F of the linear electrode 20. The power supply terminal 33 is a holder that holds the power supply line 34 relative to the first housing 10.

[0042] The power feed line 34 is a power line for supplying the AC power amplified by the first amplifier 32 to a power feed point F of the linear electrode 20. The power feed line 34 is held by a power feed terminal 33 and can be moved in the length direction of the linear electrode 20 together with the power feed terminal 33 by an actuator 36. Alternatively, only the power feed line 34 may be moved in the length direction of the linear electrode 20 by the actuator 36.

[0043] The electric field probe 40 is a sensor that measures the strength of the electric field between the linear electrode 20 and the first housing 10 when amplified AC power is supplied to the linear electrode 20. The electric field probe 40 measures the strength of the electric field within the space 10a of the first housing 10, and outputs a measurement signal (measured signal) proportional to the strength of the electric field to the detector 42 via the second amplifier 41. As will be described later, the control unit 70 controls the power supply unit 30 and the voltage converter 35, so that the electric field probe 40 outputs a measurement signal whose output value is maximized (or local maximum).

[0044] The electric field probe 40 is fixed to the first housing 10. The electric field probe 40 is disposed on the vent hole 12b side of the first housing 10, at a position on the first housing 10 opposite the other end side of the linear electrode 20.

[0045] The second amplifier 41 amplifies the measurement signal output by the electric field probe 40 and outputs the amplified measurement signal to the detector 42. The second amplifier 41 amplifies the measurement signal by a predetermined factor, but the amount of amplification may be set appropriately.

[0046] The detector 42 acquires the measurement signal amplified by the second amplifier 41 and detects the acquired measurement signal. For example, the detector 42 detects the measurement signal using a Schottky barrier diode. The detector 42 outputs a signal indicating the detection result based on the detected measurement signal to the control unit 70. The signal indicating the detection result is a signal indicating the result of monitoring the electric field strength inside the first housing 10.

[0047] The voltage converter 35 is controlled by the control unit 70 to adjust the voltage supplied to the actuator 36 based on a variable power supply such as an external power supply. The voltage converter 35 is controlled by the control unit 70 in accordance with the detection result based on the measurement signal detected by the detector 42, to adjust the voltage supplied to the actuator 36. In other words, the voltage converter 35 drives the actuator 36 by adjusting the voltage applied to the actuator 36.

[0048] The actuator 36 is connected to the power supply terminal 33 of the power supply unit 30 and is driven by application of a voltage from the voltage converter 35. The actuator 36 is, for example, a piezoelectric element that expands and contracts when a voltage is applied. The actuator 36 is driven by application of a voltage from the voltage converter 35, and moves the power supply line 34 along the length of the linear electrode 20. In other words, the actuator 36 is driven to move the power supply line 34, thereby displacing the position of a power supply point F that supplies AC power to the linear electrode 20. Specifically, as shown in FIG. 2 , the actuator 36 adjusts the position of the power supply point F relative to the linear electrode 20 by moving the position of the power supply point F by a distance Δx along the length of the linear electrode 20. The distance Δx is the amount of displacement from a reference position when an arbitrary reference position is set, and is the voltage V supplied from the voltage converter 35. ｉｎ The reference position is, for example, an initial position in a state where AC power is not supplied to the linear electrode 20, or a position halfway along the length of the linear electrode 20.

[0049] In the linear electrode 20, the average conductivity changes depending on the density of the generated plasma, and therefore the equivalent electrode length also changes. As a result, the position of the matching feed point moves slightly. The higher the resonant Q value, the more efficient the plasma generation and virus decomposition relative to the input power. However, the higher the Q value, the more important it becomes to control the feed point F and the resonant frequency in accordance with this slight movement w. This disclosure provides a solution to this problem.

[0050] The control unit 70 is, for example, a microcontroller, etc. The control unit 70 controls the power supply unit 30 and the voltage converter 35.

[0051] The control unit 70 controls the power supply unit 30 to control the AC power supplied to the linear electrode 20. That is, the control unit 70 controls the frequency of the AC power supplied to the linear electrode 20 so that the output value of the signal measured by the field probe 40 is maximized. Specifically, the control unit 70 controls the variable frequency oscillator+modulator 31 in accordance with the detection result based on the measurement signal detected by the detector 42, thereby controlling the frequency of the AC power supplied to the linear electrode 20. At this time, the control unit 70 controls the variable frequency oscillator+modulator 31 so that the phase of the current (or voltage) supplied to the feed point F and the phase of the current (or voltage) generated during resonance in the space 10a of the first housing 10 are in phase.

[0052] The control unit 70 also controls the voltage converter 35 to control the voltage applied to the actuator 36. That is, the control unit 70 also controls the supply position with respect to the linear electrode 20 so that the output value of the signal measured by the electric field probe 40 is maximized. In other words, the control unit 70 adjusts the position of the feeding point F by controlling the actuator 36 in accordance with the detection result based on the measurement signal detected by the detector 42.

[0053] In the automatic control for maintaining this resonant state, the detection result based on the measurement signal detected by the detector 42 (which shows a maximum in the resonant state) is the controlled variable, and the frequency of the power output from the variable frequency oscillator + modulator 31 and the position of the power supply point F corresponding to the output of the voltage converter 35 correspond to the manipulated variable in this automatic control.

[0054] The control unit 70 manipulates the frequency of the AC power supplied to the linear electrode 20 and the voltage applied to the actuator 36 for adjusting the position of the power supply point F, and performs feedback control so that the measurement signal measured by the electric field probe 40, which senses the strength of the electric field within the first housing 10, is maximized.

[0055] The duct 17 is a pipe that connects the space 10a of the first housing 10 and the space 50a of the second housing 50, and passes air drawn in from the intake port 12a of the first housing 10. One end of the duct 17 is connected to the ventilation port 12b of the first housing 10, and the other end of the duct 17 is connected to the ventilation port 50b of the second housing 50. In other words, the duct 17 guides the air flowing through the space 10a of the first housing 10 to the space 50a of the second housing 50.

[0056] The second housing 50 forms (defines) a space 50a that houses the filter 60 and the fan 51. The filter 60 and the fan 51 are disposed and fixed in the space 50a inside the second housing 50. The second housing 50 is made of a highly conductive conductor material, such as silver, copper, or aluminum. The second housing 50 may be an example that constitutes a part of the second electrode.

[0057] In this embodiment, the second housing 50 has, for example, a long cylindrical shape, but the shape of the second housing 50 is not particularly limited.

[0058] The second housing 50 is also formed with an air vent 50b through which air guided by the duct 17 passes, and an exhaust port 52 for discharging air that has entered through the air vent 50b to the outside of the second housing 50. The air vent 50b is formed at one end of the second housing 50 in the length direction, and the exhaust port 52 is formed at the other end of the second housing 50 in the length direction. The duct 17 is connected to the air vent 50b, through which air that has passed through the first housing 10 and the duct 17 passes. The exhaust port 52 also discharges air that has passed through the air vent 50b and the filter 60 in the space 50a of the second housing 50 to the outside.

[0059] The filter 60 can remove ozone contained in the air generated by the generation of plasma when air (air drawn in through the intake port 12a of the first housing 10) flows from the ventilation port 50b side of the second housing 50 to the exhaust port 52 side. In order to remove ozone, the filter 60 is disposed in the space 50a of the second housing 50 and near the exhaust port 52. Such a filter 60 contains activated carbon.

[0060] The filter 60 can also adsorb debris of bacteria, viruses, etc. The filter 60 adsorbs debris of bacteria, viruses, etc. contained in the air that has passed through the first housing 10 and the duct 17.

[0061] The fan 51 is a blower that generates an airflow inside the first housing 10, the duct 17, and the second housing 50 to draw air through the intake port 12a of the first housing 10 and discharge the drawn air from the exhaust port 52 of the second housing 50. The fan 51 is disposed within the space 50a of the second housing 50, and in this embodiment, is disposed closer to the exhaust port 52 of the second housing 50 than the filter 60. When the electric motor of the fan 51 is driven to rotate the propeller of the fan 51 (the fan 51 is driven), air is drawn in through the intake port 12a of the first housing 10, passes through the space 10a of the first housing 10 and the inside of the duct 17 in that order, reaches the space 50a of the second housing 50, passes through the filter 60, and is discharged from the exhaust port 52 of the second housing 50.

[0062] The driving of the fan 51 may be controlled by the control unit 70. That is, the control unit 70 may control the driving of the fan 51 when controlling the power supply unit 30 and the voltage converter 35.

[0063] <Frequency of AC Power and Position of Feeding Point F> The relationship between the frequency of AC power supplied to the feeding point F, at which the output value of the signal measured by the electric field probe 40 is maximized, and the position of the feeding point F to which AC power is supplied will be described. ｉｎ 1, and the voltage V ｉｎ The variable that depends on 1 is ν １ The control voltage of the variable frequency oscillator of the variable frequency oscillator+modulator 31, which corresponds to the frequency of the power supplied to the power supply point F, is V ｉｎ 2, and the voltage V ｉｎ The variable that depends on 2 is ν ２ The voltage of the detector output signal, which indicates the detection result output by the detector 42 to the control unit 70 and corresponds to the electric field at the electrode end, is V ０ Then, it is expressed by the following equations (1) to (3).

[0064]

[0065]

[0066]

[0067] Using the above formulas (1) to (3), the function g(ν １ , ν ２ ) is calculated. １ , ν ２ ) to find the maximum value.

[0068] The electric field is maximized when the following (Equation 4) and (Equation 5) are satisfied: １ , ν ２ ), new functions are defined as shown in (Equation 6) and (Equation 7).

[0069]

[0070]

[0071]

[0072]

[0073] Using (Equation 6) and (Equation 7), g １ (ν １ , ν ２ ) and g ２ (ν １ , ν ２ ) are zero (ν １ , ν ２ ) is expressed by the following (Equation 8) and (Equation 9).

[0074]

[0075]

[0076] In (Equation 8) and (Equation 9), , year, Ignore the above. Then, and are expressed by the following (Equation 10) and (Equation 11) using

[0077]

[0078]

[0079] Then, when equations (10) and (11) are solved, equations (12) and (13) are obtained.

[0080]

[0081]

[0082] <Operation> The operation of the air purification system 1 in this embodiment will be described.

[0083] 1 and 2 , when the air purification system 1 is operated, the control unit 70 controls the operation of the power supply unit 30 and the voltage converter 35. At this time, the control unit 70 may drive the fan 51 together with the operation of the power supply unit 30 and the voltage converter 35.

[0084] The control unit 70 controls the power supply unit 30 to generate plasma in the plasma generation region P. When air containing, for example, bacteria and viruses, is drawn in through the intake port 12 a of the first housing 10 by the rotation of the fan 51, the air passes through the plasma generation region P formed between the intake port 12 a and the linear electrode 20.

[0085] As shown in Fig. 4, bacteria, viruses, and the like contained in the air are decomposed and sterilized by the plasma as they pass through the plasma generation region P. For example, molecules, atoms, ions, electrons, and the like dissociated by the generation of plasma, as well as ozone and ultraviolet rays generated by the plasma, collide with the bacteria, viruses, and the like, decomposing them. Furthermore, fine particles contained in the air, such as dust, pollen, mites, and smoke, are also decomposed. Fig. 4 is a schematic diagram showing how viruses are decomposed in the plasma generation region P of the air purification system 1 according to embodiment 1.

[0086] 2, dust such as remains of decomposed bacteria and viruses passes through the space 10a of the first housing 10 together with the air, flows through the duct 17 to the second housing 50, and is absorbed by the filter 60 of the second housing 50 and removed from the air. As a result, the air that passes through the filter 60 is purified and is discharged from the outlet 52 of the second housing 50. In this way, the air purification system 1 can remove bacteria, viruses, and the like from the air and supply clean air.

[0087] <Modification> As a modification of the first embodiment, when the above-described filter 60 is the first filter 60 , the air purification system 1 may include a second filter 61 separate from the first filter 60 .

[0088] FIG. 5 is a schematic diagram showing the flow of air drawn into the air purification system 1 according to a modified example of embodiment 1, and changes in the power supply point F at which the power supply unit 30 supplies power to the linear electrode 20.

[0089] 5, the second filter 61 is disposed between the first filter 60 and the ventilation opening 50b of the second housing 50. In other words, the second filter 61 is disposed upstream of the first filter 60 in the air flow. The second filter 61 is configured to filter, for example, NO ２ It is a filter.

[0090] <Operational Effects> The operational effects of the air purification system 1 in this embodiment will be described.

[0091] As described above, the air purification system 1 according to the present embodiment is an air purification system 1 that generates plasma using voltage, and includes: linear electrode 20 that generates electromagnetic resonance when supplied with AC power; first housing 10 that is disposed to surround linear electrode 20 while being spaced apart from linear electrode 20; power supply unit 30 that supplies AC power to linear electrode 20; electric field probe 40 that measures the strength of the electric field between linear electrode 20 and first housing 10; and control unit 70 that controls the AC power supplied to linear electrode 20. The control unit 70 controls the frequency of the power supplied to linear electrode 20 and the position at which power is supplied to linear electrode 20, and controls the output value of a signal indicating the strength of the electric field measured by electric field probe 40 to be maximized.

[0092] According to this, by supplying AC power to the linear electrode 20, plasma can be generated between the linear electrode 20 and the first housing 10. Furthermore, the control unit 70 controls the frequency of the AC power and the position at which the AC power is supplied to the linear electrode 20. Therefore, the phase of the current when the AC power is supplied to the linear electrode 20 can be synchronized (tracked) with changes in the resonant frequency caused by the generation of plasma so that the phase of the current when the AC power is supplied to the linear electrode 20 is the same as the phase of the current generated in the linear electrode 20 during resonance. In this case, because AC power synchronized with changes in the resonant frequency can be supplied to the linear electrode 20, an electromagnetic resonant state can be constantly maintained, and the output value of the signal measured by the electric field probe 40 can be controlled to always be maximized.

[0093] Therefore, in this air purification system 1, by efficiently generating plasma while reducing input power compared to conventional systems, bacteria, viruses, and the like in the air can be decomposed.

[0094] In particular, since the input power of this air purification system 1 can be reduced, it is not difficult to create a high-voltage circuit, a step-up transformer, etc., and the power supply unit 30 that constitutes the power source of the air purification system 1 does not become large. Furthermore, this air purification system 1 can also suppress heat generation in the power supply unit 30 due to an increase in the current value and damage to the electrodes due to heat generation. Therefore, the manufacturing cost of this air purification system 1 does not increase.

[0095] The air purification system 1 may be designed to increase the Q value of resonance, in which case the AC power input to the linear electrode 20 can be reduced.

[0096] There are also methods for removing bacteria, viruses, etc. using chemical means such as peracetic acid, hydrogen peroxide, ethylene oxide gas, ozone, etc., but these methods have concerns about their effects on the human body. There are also methods for removing bacteria, viruses, etc. using physical means such as high-pressure steam, radiation, and ultraviolet rays, but these methods are not practical in terms of their effects on the human body, restrictions on usage conditions, low energy efficiency, etc. However, the air purification system 1 of the present embodiment can remove bacteria, viruses, etc. more cheaply and effectively than conventional methods.

[0097] The air purification system 1 according to this embodiment also includes an actuator 36 that displaces the position of a feeding point F at which the power feeding unit 30 supplies AC power to the linear electrode 20. The control unit 70 controls the actuator 36 to adjust the position of the feeding point F.

[0098] This allows the control unit 70 to displace the position of the feeding point F so as to maximize the output value of the signal measured by the electric field probe 40. Therefore, the air purification system 1 can easily follow the change in the resonant frequency in the electromagnetic resonance caused by the generation of plasma.

[0099] Furthermore, in the air purification system 1 according to the present embodiment, the control unit 70 controls two parameters, namely, the frequency and the position of the feed point F on the linear electrode 20, to control the actuator 36 and the power supply unit 30 so that the output voltage of the field probe 40 is maximized. In other words, the control unit 70 performs feedback control by manipulating the frequency and the position of the feed point F on the linear electrode 20 so that the output voltage of the field probe 40 is maximized.

[0100] This allows resonance to be maintained, so that plasma can be generated efficiently while more reliably suppressing input power.

[0101] In the air purification system 1 according to this embodiment, the first housing 10 is a housing in which the inlet 12a for drawing in air is formed. The first housing 10 is provided with a filter 60, which is disposed near the outlet 52 for discharging the air drawn in through the inlet 12a, and which removes nitrogen oxides and ozone generated by the plasma reactor having the wire electrode 20 and the first housing 10 when the air drawn in through the inlet 12a passes through.

[0102] This makes it possible to supply purified air from which dust such as remains of bacteria and viruses that have been decomposed by the plasma has been removed.

[0103] In the air purification system 1 according to the present embodiment, the linear electrode 20 is an elongated electrode. The first housing 10 defines an elongated space 10a that accommodates the linear electrode 20 along the longitudinal direction of the linear electrode 20. A plasma generation region P for generating plasma is defined in the space 10a between the linear electrode 20 and the intake port 12a of the first housing 10.

[0104] According to this, a plasma generation region P is formed near the intake port 12a, so that the air passing through the intake port 12a can reliably pass through the plasma generation region P. As a result, bacteria, viruses, and the like contained in the air can be reliably decomposed.

[0105] Second Embodiment An air purification system 2a according to the present embodiment will be described.

[0106] In this embodiment, the air purification system 2a differs from embodiment 1 in that it further includes a second filter unit 101, a heater unit 102, a third filter unit 103, and a first detector 105a. The configuration of the main body unit 1a in the air purification system 2a of this embodiment is similar to the configuration of the air purification system of embodiment 1, and the same components are assigned the same reference numerals, and detailed description of the configuration will be omitted. In this embodiment, the air purification system 2a of embodiment 1 will be referred to as the main body unit 1a.

[0107] Fig. 6 is a block diagram showing an air purification system 2a according to embodiment 2, further including a flow control valve 115 with a flow meter, etc. Fig. 7 is a schematic diagram showing a main body 1a of the air purification system 2a according to embodiment 2.

[0108] As shown in FIGS. 6 and 7, the air purification system 2a includes a main body 1a, a second filter unit 101, a heater unit 102, a third filter unit 103, and a first detector 105a.

[0109] The main body 1a includes a plasma reactor 3a and a first filter unit 60a.

[0110] The plasma reactor 3a has a first housing 10, a linear electrode 20, an electric field probe 40, an actuator 36, a power supply terminal 33, and a power supply line 34, as well as a spectrometer 111 and a third dielectric 112. The plasma reactor 3a may selectively have at least one of a variable frequency oscillator+modulator 31, a first amplifier 113, a second amplifier 114, a second amplifier 41, a detector 42, a voltage converter 35, a control unit 70, and a duct 17.

[0111] In the present embodiment, the air purification system 2a is provided with a first amplifier 113 and a second amplifier 114 instead of the first amplifier of the first embodiment. The first amplifier 113 is, for example, an operational amplifier that converts impedance, and the second amplifier 114 is, for example, a power amplifier. The first amplifier 113 and the second amplifier 114 are included in the configuration of the power supply unit 30.

[0112] The spectroscope 111 is disposed on the intake port 12a side of the first housing 10. Specifically, the spectroscope 111 is on the intake port 12a side of the first housing 10 and is fixed to the outer peripheral surface of the first housing 10. The spectroscope 111 detects the emission intensity of the plasma in the plasma generation region P. The spectroscope 111 may output the detection result to the control unit 70, and the control unit 70 may operate the frequency (variable frequency oscillator+modulator 31) and the position of the feeding point (output voltage of the voltage converter) in accordance with the detection result.

[0113] The third dielectric 112 is disposed within the space 10a of the first housing 10. Specifically, the third dielectric 112 is disposed near the intake port 12a of the first housing 10 so as to surround or sandwich the intake port 12a. The third dielectric 112 is also located near the second dielectric 23 at one end of the linear electrode 20. The third dielectric 112 is a highly heat-resistant dielectric material. The third dielectric 112 is, for example, quartz glass or a ceramic such as alumina.

[0114] The first filter unit 60a includes a second housing 50, a first filter 60, a second filter 61, a fan 51, and a flow control valve with a flow meter 115. The first filter unit 60a may also include a duct 17. In the present embodiment, activated carbon is used for the first filter 60, but instead of activated carbon, nitrogen oxides may be decomposed by a catalyst by combining ammonia with the first filter.

[0115] The flow control valve 115 with a flow meter is disposed between the fan 51 and the first filter 60. In other words, the flow control valve 115 with a flow meter measures and controls the flow rate of the air that flows from the first filter 60 to the fan 51 and has passed through the first filter 60.

[0116] The second filter unit 101 filters the air before it is drawn in as outside air through the inlet 12a of the first housing 10 of the plasma reactor 3a. In other words, the second filter unit 101 is an air filter located upstream of the plasma reactor 3a. The second filter unit 101 removes airborne particles contained in the air before it is drawn into the plasma reactor 3a. Airborne particles include not only bacteria and viruses, but also fine particles such as dust, pollen, mites, and smoke. The second filter unit 101 is, for example, activated carbon, a photocatalyst, a HEPA (High Efficiency Particulate Air Filter) filter, a ULPA (Ultra Low Penetration Air Filter) filter, a MEPA (Medium Efficiency Particulate Air Filter) filter, etc. The air that has passed through the second filter unit 101 and from which suspended particles have been removed flows to the heater unit 102.

[0117] The heater unit 102 adjusts the amount of moisture contained in the air that has passed through the second filter unit 101, thereby adjusting the amount of moisture (humidity) of the air that flows into the plasma reactor 3a of the main body unit 1a. The heater unit 102 has a humidity control heater for adjusting the humidity of the air that passes through it, and a mist separator for separating the moisture contained in the air from the air. The air that has passed through the heater unit 102 and has had its humidity adjusted flows into the plasma reactor 3a.

[0118] The plasma reactor 3a decomposes bacteria, viruses, and the like contained in the air that flows into the plasma reactor 3a from the heater unit 102. The plasma reactor 3a is supplied with AC power controlled by the control unit 70 so that the plasma imparts energy to the gas molecules that is intermediate between the dissociation energy of oxygen molecules (approximately 5 eV) and the dissociation energy of nitrogen molecules (approximately 9 eV) contained in the air, causing only the oxygen molecules to dissociate. The air that has passed through the plasma reactor 3a is filtered by the first filter unit 60a and flows to the third filter unit 103.

[0119] The third filter unit 103 further filters the air that has passed through the plasma reactor 3a and the first filter unit 60a. That is, the third filter unit 103 is an air filter disposed downstream of the plasma reactor 3a. The third filter unit 103 removes dust contained in the air that has passed through the plasma reactor 3a. The third filter unit 103 is, for example, an activated carbon filter, a photocatalyst filter, a HEPA filter, a ULPA filter, a MEPA filter, or the like. The air that has passed through the third filter unit 103 and from which dust has been removed (purified air) flows to the first detector 105a.

[0120] The first detector 105a detects and measures the amounts of ozone and nitrogen oxides contained in the purified air generated by the plasma generation. The first detector 105a outputs the measurement results of the amounts of ozone and nitrogen oxides contained in the purified air to the control unit 70. The first detector 105a is an example of a detector.

[0121] Based on the measurement results of the ozone and nitrogen oxide contents in the air measured by the first detector 105a, the control unit 70 controls the power supplied to the wire electrode 20 by operating the variable frequency oscillator+modulator 31 and the amplifier 32 to control the plasma so that the amount of ozone is always constant and the dissociation energy between oxygen molecules and nitrogen molecules is an intermediate value at which nitrogen oxides are substantially not generated. This control may be a feedback control using this operation. Furthermore, if the control unit 70 measures ozone and nitrogen oxides exceeding specified amounts, it controls the air purification system 2a to temporarily suspend the system so that purified air is not discharged from the system.

[0122] Furthermore, to maintain a constant amount of ozone, the control unit 70 controls the amplitude of the AC power supplied to the linear electrode 20 via the variable frequency oscillator / modulator 31 based on the measurement results from the first detector 105a, etc., performs amplitude modulation on the AC power, or controls the amplitude modulation so that it intermittently alternates between a constant value and zero. This control may be feedback control. For example, the control unit 70 controls the amount of plasma generated by controlling the duty ratio of the AC power through amplitude modulation. This allows the amount of ozone and nitrogen oxides contained in the purified air to be controlled.

[0123] Furthermore, when the control unit 70 performs amplitude modulation via the variable frequency oscillator+modulator 31, the waveform of the AC power supplied to the linear electrode 20 becomes a waveform in which the carrier wave is amplitude-modulated. At this time, the control unit 70 manipulates the power supplied to the linear electrode 20 via the variable frequency oscillator+modulator 31 to control the ozone concentration to, for example, the amount of ozone originally contained in the Earth's atmosphere or less, preferably to 0.1 ppm or less. This control may be feedback control.

[0124] <Operational Effects> The operational effects of the air purification system 1 in this embodiment will be described.

[0125] For example, conventional air purification systems have difficulty controlling the dissociation of nitrogen molecules and the resulting generation of nitrogen oxides caused by the correspondingly strong electric field at the peak of the pulse.

[0126] Therefore, the air purification system 2a of this embodiment is provided with a first detector 105a that monitors the amounts of ozone and nitrogen oxides generated. While ozone is generated by dissociating oxygen molecules with plasma, this air purification system 2a inputs energy to gas molecules so that nitrogen molecules do not dissociate and the generation of nitrogen oxides is minimized. The amounts of ozone and nitrogen oxides generated are set as target values ​​to be controlled, and the waveform of the input power, amplitude modulation, and the electric field applied to the plasma are manipulated while maintaining an electromagnetic resonance state, thereby preventing the emission of harmful gases and enabling safe and highly efficient air purification. The control corresponding to these operations may be feedback control.

[0127] As described above, in the air purification system 1 according to the present embodiment, the control unit 70 acquires from the first detector 105a the measurement result of the ozone content contained in the air that has passed between the linear electrode 20 and the first housing 10 (or through the plasma generation region P), and, based on the acquired measurement result, controls the supplied power to control the air passing between the linear electrode 20 and the first housing 10 so that the amount of ozone always generated by plasma generation is constant and the dissociation energy between oxygen molecules and nitrogen molecules is an intermediate value that does not substantially generate nitrogen oxides. This operation may be a feedback control.

[0128] This allows the plasma reactor 3a to efficiently generate the minimum amount of ozone necessary to decompose viruses, and the concentration of ozone contained in the purified air to a level that is not harmful to humans, etc., while also killing bacteria and viruses contained in the air and allowing the generated ozone to be easily removed by the filter 60.

[0129] In the air purification system 1 according to this embodiment, the power supplied to the linear electrode 20 is AC power. The control unit 70 controls the amount of ozone generated to be constant. For example, the amplitude of the supplied AC power is manipulated to control the amount of ozone generated to be equal to or less than the amount of ozone originally contained in the Earth's atmosphere. This control may be feedback control.

[0130] Even in this case, the concentration of ozone contained in the purified air can be made to be a concentration that is less harmful to humans, for example, less than the amount of ozone originally contained in the Earth's atmosphere, and bacteria and viruses contained in the air can be killed, while the generated ozone can be easily removed by the filter 60.

[0131] In the air purification system 1 according to this embodiment, the waveform of the AC power supplied to the linear electrode 20 is a waveform in which a carrier wave is amplitude-modulated. The control unit 70 controls the amplitude modulation to keep the amount of ozone generated constant, for example, so that the amount is equal to or less than the amount of ozone originally contained in the Earth's atmosphere. This control may be feedback control.

[0132] Even in this case, the concentration of ozone contained in the purified air can be made less harmful to humans, for example, less than the amount of ozone originally contained in the Earth's atmosphere, and bacteria and viruses contained in the air can be killed, while the generated ozone can be easily removed by the filter 60.

[0133] In the air purification system 1 according to this embodiment, the waveform of the AC power supplied to the linear electrode 20 is a waveform in which a carrier wave is amplitude-modulated. The control unit 70 controls the amount of ozone generated to be constant. For example, to control the amount of ozone generated to be equal to or less than the amount originally contained in the Earth's atmosphere, the time interval between the amplitude modulation is manipulated so that it intermittently alternates between a constant value and zero. This control may be feedback control.

[0134] Even in this case, the concentration of ozone contained in the purified air can be made to be a concentration that is less harmful to humans, for example, less than the amount of ozone originally contained in the Earth's atmosphere, and bacteria and viruses contained in the air can be killed, while the generated ozone can be easily removed by the filter 60.

[0135] In the air purification system 1 according to the present embodiment, the control unit 70 controls the supplied power to control the ozone concentration to 0.1 ppm or less. This control may be feedback control.

[0136] Even in this case, the concentration of ozone contained in the purified air can be made less harmful to humans, for example, to a level lower than the amount of ozone originally contained in the Earth's atmosphere, and bacteria and viruses contained in the air can be killed, while the generated ozone can be easily removed by the filter 60.

[0137] Furthermore, in the air purification system 1 according to this embodiment, plasma is generated using a high voltage of a continuous wave that is frequency modulated at 100 MHz to 10 GHz.

[0138] In this air purification system 1, the Q value is 1000 or more, so the input high-frequency voltage can be accurately boosted by 1000 times or more. In this case, the power supplied from the first amplifier 32 to the linear electrode 20 of the air purification system 1 is at an efficiency of 99% or more, so the power efficiency is essentially 100%. When a high-frequency voltage of 100 MHz to 10 GHz is supplied to the linear electrode 20, the oscillation amplitude of electrons in the first housing 10 is not very large and the electron speed is limited to a certain range, making it possible to generate high-density plasma.

[0139] For example, the dissociation energy of nitrogen molecules is approximately 9 eV, the dissociation energy of oxygen molecules is approximately 5 eV, and the envelope destruction energy of viruses contained in the air is approximately 5 eV or less. The air purification system 1 applies energy of approximately 5 eV or more to gas molecules to efficiently generate ozone by dissociating oxygen molecules while suppressing the generation of nitrogen oxides. This not only allows ionized ions, electrons, and radicals to directly attack viruses (i.e., inelastic collisions), but also efficiently generates ozone through the dissociation of oxygen molecules, thereby decomposing viruses and suppressing the generation of harmful nitrogen oxides. Furthermore, in the present invention, changes in the resonance state due to changes in the type and amount of inflowing gas molecules and changes in the plasma state can be controlled by adjusting and manipulating the frequency of the input power and the position of the power supply point, thereby performing feedback control to always maintain an electromagnetic resonance state and maintaining a high "power-virus" decomposition efficiency. Furthermore, by manipulating the strength of the input power (which can be the average strength) and, for example, the waveform and amplitude of the input power in the resonance state, it is possible to efficiently generate the minimum amount of ozone necessary to decompose viruses, while controlling the ozone concentration contained in the air ultimately discharged from the air purifier for human breathing to 0.1 ppm or less, or to a level similar to the amount originally contained in the Earth's atmosphere. The control corresponding to this series of operations may be feedback control.

[0140] Furthermore, if the ozone concentration is 0.1 ppm or less, it can be removed by a filter 60 or the like. In order to provide the gas molecules input into the plasma reactor 3a with energy equal to or greater than the dissociation energy of oxygen and equal to or less than the dissociation energy of nitrogen, or energy equivalent to the dissociation energy of oxygen, the detection result of the first detector 105 is fed back to the control unit 70. As a result, while generating the minimum amount of ozone necessary for decomposing bacteria, viruses, etc., purified air in which the generation of nitrogen oxides is suppressed can be supplied as purified air necessary for breathing to humans.

[0141] If a high-frequency high voltage is supplied to the linear electrode 20, and energy exceeding the dissociation energy of nitrogen molecules contained in the gas input to the plasma reactor 3a is applied, nitrogen oxides will be generated by the nitrogen molecules contained in the air, and excessive ozone will be generated when the purpose is to decompose viruses. By controlling the generation of plasma (the control unit 70 controls the high-frequency AC power supplied to the linear electrode 20) so that nitrogen oxides are not generated and the concentration of ozone contained in the purified air is a concentration that is harmless to humans (e.g., 0.1 ppm), bacteria and viruses contained in the air can be killed with the minimum amount of ozone necessary, and excess ozone can be easily removed by the filter 60.

[0142] <Modification 1> Figure 8 is a block diagram showing an air purification system 2b according to Modification 1 of Embodiment 2, which includes a second filter unit 101, a heater unit 102, a second detector 105b, a first filter unit 60a, a first detector 105a, and a pipe 17a. In Figure 8, the flow of outside air is indicated by solid arrows, and the flow of signals such as measurement results is indicated by dashed arrows.

[0143] The air purification system 2b of this modified example differs from the second embodiment in that the main body 1b includes a control unit 70, etc.

[0144] As a first modification of the second embodiment, the air purification system 2b includes a main body 1b, a second filter 101, a heater 102, a second detector 105b, a first filter 60a, and a first detector 105a. In this modification, the air purification system 2b does not include the third filter of the second embodiment. In this modification, the first filter 60a is used instead of the third filter of the second embodiment.

[0145] The main body 1b includes a plasma reactor 3b and a control unit 70. In this embodiment, the main body 1b does not include a first filter unit 60a. The first filter unit 60a is disposed downstream of the plasma reactor 3b, because air that has passed through the plasma reactor 3b flows into the first filter unit 60a. The main body 1b includes the variable frequency oscillator+modulator 31, first amplifier 113, second amplifier 114, second amplifier 41, detector 42, voltage converter 35, duct 17, second housing 50, filter 60, fan 51, and the like shown in FIG. 7, but the configuration is simplified in FIG. 8.

[0146] The plasma reactor 3b has a first housing 10, a linear electrode 20, a power supply unit 30, an electric field probe 40, an actuator 36, a spectrometer 111, a third dielectric 112, a first amplifier 113, a second amplifier 114, a second amplifier 41, a detector 42, and a voltage converter 35.

[0147] The second detector 105b is disposed between the plasma reactor 3b and the first filter unit 60a, and the air that has passed through the plasma reactor 3b passes through it. The second detector 105b detects and measures the amount of ozone and nitrogen oxides contained in the gas that has been purified by the plasma and in which bacteria, viruses, etc. have been decomposed. Like the first detector 105a, the second detector 105b also outputs the measurement results of the amount of ozone and nitrogen oxides contained in the purified air to the control unit 70. The second detector 105b may also be an example of a detector.

[0148] The control unit 70 controls the AC power supplied to the power supply unit 30 and the linear electrode 20 of the plasma reactor 3b, using the measurement result of the second detector 105b as a control target. This control may be feedback control. When ozone and nitrogen oxides exceeding a specified amount are measured, the control unit 70 controls the AC power supplied to the linear electrode 20 to suppress the generation of ozone and nitrogen oxides. This control may be feedback control.

[0149] Furthermore, the air purification system 2b of this modified example is provided with a pipe 17a that returns the air that has passed through the second detector 105b to the plasma reactor 3b. For example, the pipe 17a connects the exhaust port side of the first housing 10 of the plasma reactor 3b to the intake port 12a side. In this embodiment, the pipe 17a connects the duct that connects the second detector 105b and the first filter unit 60a to the duct that connects the heater unit 102 and the plasma reactor 3b. The pipe 17a returns a portion of the air that has passed through the first housing 10 to the intake port 12a side of the first housing 10 so as to circulate the air. Note that the pipe 17a may be provided with a fan or the like for returning air to the plasma reactor 3b.

[0150] The first detector 105a is passed by the gas that has passed through the first filter portion 60a and has been purified.

[0151] The air purification system 2b according to this modified example has a pipe 17a that returns a portion of the air that is drawn in through the intake port 12a and passes through the inside of the first housing 10 (plasma reactor 3b) to the intake port 12a side.

[0152] In this way, by returning a portion of the air that has passed through the first housing 10 to the inlet 12a side, it is possible to reliably decompose suspended matter such as bacteria and viruses again. In this way, by circulating a portion of the air that has passed through the first housing 10, it is possible to achieve further purification of the air.

[0153] <Modification 2> Fig. 9 is a block diagram showing an air purification system 2c according to Modification 2 of Embodiment 2, which includes a second filter unit 101, a heater unit 102, a second detector 105b, a pipe 17a, a first filter unit 60a, and a first detector 105a, and in which the second detector 105b is provided on the pipe 17a.

[0154] The air purification system 2c of this modification differs from the first modification of the second embodiment in that a second detector 105b is provided on a pipe 17a.

[0155] As shown in Fig. 9, the pipe 17a connects the duct connecting the plasma reactor 3b and the first filter unit 60a to the duct connecting the heater unit 102 and the plasma reactor 3b. A second detector 105b is disposed on the pipe 17a. Note that the main body 1b includes the variable frequency oscillator+modulator 31, first amplifier 113, second amplifier 114, second amplifier 41, detector 42, voltage converter 35, duct 17, second housing 50, filter 60, fan 51, and the like shown in Fig. 7, but the configuration is simplified in Fig. 9.

[0156] The first filter unit 60a is connected to the plasma reactor 3b and filters the air that has passed through the plasma reactor 3b.

[0157] In the air purification system 2c, in order to prevent the generation of nitrogen oxides that are harmful to the human body, N ２ At a dissociation energy (for example, about 9 eV) or less, O ２ The energy near the dissociation energy (for example, about 5 eV) of the molecules (O ２ , N ２ The control unit 70 controls the intensity or waveform (average intensity) of the power input to the plasma reactor 3b so that the power is supplied to the plasma reactor 3b. This control may be a feedback control. The control unit 70 controls the output of the second detector 105b inside or outside the plasma reactor 3b so that the ozone generation amount is, for example, 1 ppm or less.

[0158] In this way, in this modification, the control unit 70 controls the input power to the plasma reactor 3b so that the gas input to the plasma reactor 3b is supplied with energy that is equal to or greater than the dissociation energy of oxygen molecules and less than the dissociation energy of nitrogen molecules contained in the air drawn in through the intake port 12a. This control may be feedback control.

[0159] <Variation 3> FIG. 10 is a block diagram showing an air purification system 2e according to Variation 3 of Embodiment 2, which has a second filter section 101, a heater section 102, and a first detector 105a, and uses a main body section 1a having a control section 70 and the like.

[0160] The air purification system 2e of this modification differs from the modification 2 of the second embodiment in that the second detector and piping are not provided, and the main body 1c has a first filter unit 60a.

[0161] 10, the main body 1c of this modification includes a plasma reactor 3b, a first filter unit 60a, and a control unit 70. Note that the main body 1c also includes the variable frequency oscillator+modulator 31, first amplifier 113, second amplifier 114, second amplifier 41, detector 42, voltage converter 35, duct 17, second housing 50, filter 60, fan 51, and the like shown in FIG. 7, but the configuration is simplified in FIG.

[0162] <Modification 4> FIG. 11 is a block diagram showing an air purification system 2f according to Modification 4 of Embodiment 2, which includes a second filter unit 101, a heater unit 102, and a first detector 105a.

[0163] The air purification system 2f of this modification differs from the third modification of the second embodiment in that the main body 1a of FIG. 6 is used.

[0164] 11, the main body 1a includes a plasma reactor 3a and a first filter unit 60a. The plasma reactor 3a includes the first housing 10, the linear electrode 20, the power supply unit 30, the actuator 36, the spectrometer 111, the third dielectric 112, the electric field probe 40, the second amplifier 41, the detector 42, the voltage converter 35, and the control unit 70 shown in FIG.

[0165] <Fifth Modification> FIG. 12 is a block diagram showing an air purification system 2g according to a fifth modification of the second embodiment, which includes a second filter unit 101 and a first detector 105a.

[0166] The air purification system 2g of this modification differs from the fourth modification of the second embodiment in that it does not include a heater unit.

[0167] As shown in FIG. 12, the second filter section 101 is connected to the main body section 1a, and the air that has passed through the second filter section 101 is drawn into the plasma reactor 3a of the main body section 1a.

[0168] <Sixth Modification> FIG. 13 is a block diagram showing an air purification system 2h according to a sixth modification of the second embodiment, which includes a first detector 105a.

[0169] The air purification system 2h of this modification differs from the fifth modification of the second embodiment in that the second filter unit is not provided.

[0170] As shown in FIG. 13, the plasma reactor 3a of the main body 1a directly draws in the ambient air.

[0171] Third Embodiment A protective suit 200 according to this embodiment will be described.

[0172] The present embodiment differs from the first embodiment in that protective clothing 200 is equipped with an air purification system 100. The configuration of air purification system 100 of the present embodiment is similar to the configuration of the air purification system of the first embodiment, and the same components are designated by the same reference numerals, and detailed description of the configurations will be omitted.

[0173] Fig. 14 is a front view of protective clothing 200 according to embodiment 3 and a schematic diagram showing display unit 201d of protective clothing 200. Fig. 15 is a side view showing protective clothing 200 according to embodiment 3 as viewed from the side.

[0174] As shown in FIGS. 14 and 15, the protective clothing 200 includes the air purification system 100, a cover 201, and a display unit 201d.

[0175] The air purification system 100 purifies air drawn in from the outside and supplies the purified air into the covering 201. In other words, the air purification system 100 purifies the air by decomposing and removing bacteria, viruses, and the like contained in the air, and supplies the purified air into the covering 201.

[0176] The covering 201 is protective clothing 200 equipped with the air purification system 100 and covering the surface of a person's body. The covering 201 can cover the entire body of a person and keep the interior sealed. The covering 201 includes an outer shell 201x that covers the head, upper limbs, trunk, and lower limbs of the wearer, a helmet 201a that protects the head from above the outer shell 201x, gloves 201b that protect both hands, and boots 201c that protect both feet. The outer shell 201x and the helmet 201a are joined by a joining member such as a joint, the outer shell 201x and the gloves 201b are joined by another joining member, and the outer shell 201x and the boots 201c are joined by yet another joining member.

[0177] A housing 90 that houses the air purification system 100 is attached to the back side of the covering 201. The housing 90 constitutes an exterior cover for the air purification system 100. The housing 90 may be included in the configuration of the protective suit 200, or may be included in the configuration of the air purification system 100.

[0178] Fig. 16 is a front view showing how the air purification system 100 mounted on the protective clothing 200 according to embodiment 3 sucks in viruses and the like along with air. Fig. 17 is a cross-sectional view showing the air purification system 100 mounted on the protective clothing 200 according to embodiment 3, taken along line XVI-XVI in Fig. 16. The arrows in Fig. 17 indicate the intake and exhaust of air.

[0179] As shown in FIGS. 16 and 17 , the air purification system 100 draws in ambient air through a plurality of intake ports 12a formed on the rear side of the housing 90 (the side opposite the covering 201). The drawn-in air is purified by the air purification system 100 and supplied into the protective suit 200 through a supply pipe 91. The air purification system 100 also exhausts the air drawn into the covering 201 through a plurality of exhaust ports 52 formed on the rear side of the housing 90. The exhausted air is the air inside the protective suit 200 that is exhausted to the outside of the protective suit 200 through the supply pipe 92. The protective suit 200 supplies air purified through the air purification system 100 to the inside of the protective suit 200, and exhausts air breathed by a person inside the protective suit 200 from the inside of the protective suit 200 to the outside. The purified air supplied to the inside of the protective suit 200 and the exhausted air are supplied by a micropump unit or the like. That is, purified air is supplied and exhausted so that a person can breathe inside the protective suit 200. The housing 90 may be equipped with a carbon dioxide absorbent material capable of treating carbon dioxide exhausted by a person through breathing.

[0180] In this embodiment, the plurality of intake ports 12a and the plurality of exhaust ports 52 formed on the rear side of the housing body 90 are arranged alternately one by one. Note that the arrangement of the intake ports 12a and the exhaust ports 52 is not limited to this embodiment, and for example, they may be arranged alternately in groups of multiples.

[0181] The display unit 201d is a monitor attached to the front side of the enclosure 201. The display unit 201d displays, for example, information about the inside of the enclosure 201. The information displayed may include, for example, the level of purified air inside the enclosure 201, the temperature and humidity inside the enclosure 201, and the remaining battery level. The display unit 201d displays the information under the control of the control unit 70 of the air purification system 100.

[0182] <Operations and Effects> Operations and effects of the protective suit 200 according to this embodiment will be described.

[0183] As described above, protective clothing 200 according to this embodiment includes air purification system 100 and covering body 201 that is equipped with air purification system 100 and covers the surface of a person's body. Air purification system 100 purifies air taken in from the outside and supplies the purified air into covering body 201.

[0184] This allows people to act safely even in an environment where bacteria, viruses, etc. are floating in the air.

[0185] Furthermore, this protective suit 200 also provides the same effects as those of the first embodiment and the like.

[0186] (Other Modifications) Although the present disclosure has been described above based on the first to third embodiments, the present disclosure is not limited to the first to third embodiments.

[0187] For example, the air purification systems and protective clothing using the air purification systems according to the first to third embodiments are designed to increase the Q value of the linear electrodes and the resonators in the first housing. The Q value of the resonance is determined by the ratio of the resistance of the linear electrodes to the resistance of the power supply line (input power loss).

[0188] For example, the air purification system of the second embodiment may be configured with a plasma reactor and a first filter unit, as shown in FIG.

[0189] In addition, the present disclosure also includes forms obtained by applying various modifications to embodiments 1 to 3 that a person skilled in the art would conceive, and forms realized by arbitrarily combining the components and functions of embodiments 1 to 3 within the scope of the present invention.

[0190] The air purification system and protective clothing using the air purification system of the present disclosure can be used in devices such as air purifiers, or when active in areas where bacteria, viruses, etc. are prevalent.

[0191] REFERENCE SIGNS LIST 1, 100 Air purification system 3a, 3b Plasma reactor 10 First housing (second electrode) 10a Space 12a Inlet 20 Linear electrode (first electrode) 30 Power supply unit 36 ​​Actuator 40 Electric field probe 52 Outlet 60 Filter 70 Control unit 105a First detector 200 Protective clothing 201 Covering body P Plasma generation region

Claims

1. An air purification system that generates plasma using voltage, comprising: a first electrode that generates electromagnetic resonance when power is supplied; a second electrode that is disposed so as to surround the first electrode while being separated from the first electrode; a power supply unit that supplies power to the first electrode; an electric field probe that measures the strength of the electric field between the first electrode and the second electrode; and a control unit that controls the power supplied to the first electrode. The control unit operates the frequency of the power supplied to the first electrode and the position at which power is supplied to the first electrode, and controls so that the output value of the signal indicating the strength of the electric field measured by the electric field probe becomes maximum. An air purification system.

2. The control unit obtains, from a detector, a measurement result of measuring the content of ozone contained in the air that has passed between the first electrode and the second electrode, and based on the obtained measurement result, operates the power to be supplied, and controls so that the amount of ozone always generated by the generation of plasma becomes a value intermediate between the dissociation energies of oxygen molecules and nitrogen molecules at which the amount of ozone is constant and substantially no nitrogen oxides are generated. The air purification system according to claim 1.

3. The power supplied to the first electrode is alternating current power, and the control unit operates the amplitude of the supplied alternating current power and controls so that the amount of ozone always generated becomes constant. The air purification system according to claim 2.

4. The waveform of the alternating current power supplied to the first electrode is a waveform in which a carrier wave is amplitude-modulated, and the control unit operates the amplitude modulation and controls so that the amount of ozone generated becomes constant. The air purification system according to claim 3.

5. The waveform of the alternating current power supplied to the first electrode is a waveform in which a carrier wave is amplitude-modulated, and the control unit operates so that the amplitude modulation intermittently repeats a constant value and zero, and controls so that the amount of ozone generated becomes constant. The air purification system according to claim 4.

6. The control unit operates the power to be supplied and controls so that the concentration of ozone generated becomes 0.1 ppm or less. The air purification system according to any one of claims 1 to 5.

7. The air purification system according to any one of claims 1 to 6, further comprising an actuator that displaces the position of the power supply point at which the power supply unit supplies power to the first electrode, and the control unit adjusts the position of the power supply point by operating the actuator.

8. The air purification system according to claim 7, wherein the control unit controls the output voltage of the electric field probe to be maximized by operating two parameters, namely, the frequency and the position of the power supply point on the first electrode.

9. The air purification system according to any one of claims 1 to 8, wherein the second electrode is a housing in which an air inlet for sucking air is formed, and is disposed near an air outlet for discharging the air sucked from the air inlet. When the air sucked from the air inlet passes through, it is provided with a filter for removing nitrogen oxides and ozone generated by the plasma reactor having the first electrode and the second electrode.

10. The air purification system according to any one of claims 1 to 9, wherein the first electrode is a long electrode, the second electrode forms a long space for accommodating the first electrode along the length direction of the first electrode, and a plasma generation region for generating plasma is formed in the space between the first electrode and the air inlet of the second electrode.

11. The air purification system according to claim 9 or 10, wherein the control unit operates the input power to the plasma reactor so that the dissociation energy of oxygen molecules contained in the air sucked from the air inlet is applied.

12. The air purification system according to any one of claims 1 to 11, wherein plasma is generated using a waveform power obtained by amplitude-modulating a carrier wave of 100 MHz to 10 GHz so that the ozone generation amount is constant.

13. A protective clothing comprising the air purification system according to any one of claims 1 to 12 and a covering body that mounts the air purification system and covers the surface of a human body, wherein the air purification system purifies the air sucked from the outside and supplies the purified air into the covering body.

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