Air purification device and air purification method

Abstract

To enable efficient purification of a greater volume of air at a low cost.SOLUTION: An air purification device comprises: a housing; a blower that generates a swirling flow; a light source that irradiates inflow air with vacuum ultraviolet rays, thereby generating ozone; a dividing wall that divides, into a first mixing chamber and a second mixing chamber, a space in which a mixed gas is generated as a result of mixing the generated ozone and the inflow air by means of the swirling flow; and an ozone decomposition catalyst that decomposes the ozone to generate active oxygen and purifies the air contained in the mixed gas, using the generated active oxygen.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an air purification device and a method for purifying air. [Background technology]

[0002] Air purifiers that take in air and purify it are known (see, for example, Patent Documents 1 to 3). Such air purifiers utilize the sterilization and deodorization effects of HEPA filters, ultraviolet rays, ozone, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-101748 A [Patent Document 2] JP 2013-153897 A [Patent Document 3] JP 2019-111268 A Summary of the Invention [Problem to be solved by the invention]

[0004] In such air purifiers, a combination of multiple technologies has generally been used to remove various particles to be sterilized and deodorized, such as odor molecules, viruses, pollen, etc. Vacuum ultraviolet rays react with oxygen in the air to generate ozone and active oxygen, so sterilization and deodorization effects can be expected from the active oxygen. However, bacteria, mold, pollen, etc., which are larger than viruses, may take time to be sterilized and deodorized by ozone, and it has been difficult to quickly purify the air in the entire room, for example. On the other hand, sterilizing rays including UVC have a sterilizing effect of breaking down the nucleic acids of viruses, bacteria, etc., but it has been difficult to quickly sterilize the air in the entire room, as with ozone, etc.

[0005] The present invention has been made in consideration of these points, and has an object to make it possible to purify a larger amount of air efficiently at low cost. [Means for solving the problem]

[0006] In a first aspect of the present invention, there is provided a housing having an intake port and an exhaust port, a blower that generates a swirling flow that causes air to be purified to flow into the housing from the intake port and exhaust the purified air from the exhaust port, a light source that irradiates the flowing-in air with vacuum ultraviolet light to generate ozone inside the housing, a partition wall that divides a space between the light source and the exhaust port into a first mixing chamber and a second mixing chamber, where the generated ozone and the flowing-in air are mixed by the swirling flow to generate a mixed gas, and a partition wall that divides the space into a first mixing chamber and a second mixing chamber, where the generated mixed gas flows in by the swirling flow and the ozone is mixed with the flowing-in air. and an ozone decomposition catalyst that decomposes ozone to generate active oxygen and purifies the air contained in the mixed gas with the generated active oxygen, the dividing wall is provided so as to divide a space in which the mixed gas is generated into two regions and to make a longitudinal movement speed of the mixed gas moving from the second mixing chamber to the ozone decomposition catalyst smaller than a longitudinal movement speed of the mixed gas moving from the first mixing chamber to the ozone decomposition catalyst, and has a through hole for allowing a part of the swirling flow to flow from the first mixing chamber to the second mixing chamber.

[0007] The housing may have a cylindrical shape with a longitudinal direction extending from the intake port to the exhaust port, and the second mixing chamber may be located farther from the longitudinal central axis of the housing than the first mixing chamber.

[0008] The air purification device may further include a humidifier for humidifying the second mixing chamber. The light source may irradiate the air with the vacuum ultraviolet light containing light with a wavelength of 185 nm and the deep ultraviolet light containing light with a wavelength of 254 nm.

[0009] The air purifying device may further include a light shielding plate that blocks and reduces light emitted by the light source that leaks from the air intake port to the outside of the housing, while reflecting light directed toward the blower into the space in which the first mixing chamber or the second mixing chamber is located.

[0010] The air purification device may further include an ozone sensor disposed between the ozone decomposition catalyst and the exhaust port, the ozone sensor detecting a concentration of the ozone.

[0011] The air purifier may further include a control unit that adjusts at least one of the flow rate of the swirling flow of the blower, the timing of turning the light source on and off, and the light intensity of the light source based on the detection result of the ozone concentration by the ozone sensor, so that the detection result of the ozone concentration is below a predetermined value.

[0012] In a second aspect of the present invention, there is provided a method for purifying air using a housing having an intake port and an exhaust port facing the intake port, the method including the steps of generating a swirling flow for causing the air to be purified to flow from the intake port into the inside of the housing, irradiating the flowing-in air with vacuum ultraviolet light inside the housing to generate ozone, mixing the generated ozone and the flowing-in air by the swirling flow in a first mixing chamber and a second mixing chamber inside the housing to generate a mixed gas, a dividing wall dividing the first mixing chamber and the second mixing chamber having a through hole, causing a portion of the swirling flow to flow from the first mixing chamber to the second mixing chamber, and causing the mixed gas generated in the first mixing chamber to flow into an ozone decomposition catalyst by the swirling flow to generate active oxygen that decomposes the ozone, and the mixed gas generated in the second mixing chamber and the mixed gas flowing from the first mixing chamber through the through hole into the second mixing chamber by the swirling flow to generate active oxygen that decomposes the ozone, and purifying the air contained in the mixed gas by the generated active oxygen; and exhausting the purified air from the exhaust port by the swirling flow, wherein the dividing wall divides a space in which the mixed gas is generated into two regions, and is provided so that a longitudinal movement speed of the mixed gas moving from the second mixing chamber to the ozone decomposition catalyst is smaller than a longitudinal movement speed of the mixed gas moving from the first mixing chamber to the ozone decomposition catalyst. Effect of the Invention

[0013] The present invention has the effect of being able to purify a larger amount of air efficiently at low cost. [Brief description of the drawings]

[0014] [Figure 1] 1 shows an example of the configuration of an air purifying device 10 according to this embodiment. [Diagram 2] 1 shows an example of a cross-sectional configuration of an air purifying device 10 according to this embodiment. [Diagram 3] An example of an operation flow of the air purifying device 10 according to this embodiment will be shown. [Figure 4] 1 shows a modified example of the air purifying device 10 according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] <Configuration Example of Air Purifier 10> FIG. 1 shows an example of the configuration of an air purifier 10 according to this embodiment. In this embodiment, three mutually orthogonal axes are designated as an X-axis, a Y-axis, and a Z-axis. The air purifier 10 takes in and purifies indoor air using ozone, germicidal rays, and active oxygen. The air purifier 10 has a plurality of spaces with different purification speeds, and efficiently purifies the air by dividing the air to be purified into appropriate spaces and purifying the air.

[0016] The air purifier 10 includes a housing 13 having an intake port 11 and an exhaust port 12. Fig. 1 shows an example in which the exhaust port 12 is provided to face the intake port 11. Fig. 1 also shows an example in which the housing 13 has a cylindrical shape with the direction from the intake port 11 toward the exhaust port 12 as the longitudinal direction (the direction of the Z axis). The air purifier 10 further includes a blower 110, a light source 120, a light shielding plate 130, a partition wall 140, a first mixing chamber 150, a second mixing chamber 160, an ozone decomposition catalyst 170, an activated carbon filter 180, an ozone sensor 190, and a control unit 200.

[0017] Air to be purified flows in through the air intake 11. The air intake 11 desirably has a filter 14 for preventing dust and the like from entering the inside of the housing 13. The filter 14 is, for example, an air filter known as a medium-performance filter. The filter 14 may also be an electrically charged filter, an antibacterial agent-coated filter, or the like. The air taken in through the air intake 11 is purified by the air purifier 10, and the purified air is exhausted from the exhaust port 12.

[0018] The blower 110 generates a swirling flow that causes the air to be purified to flow from the intake port 11 into the inside of the housing 13 and exhausts the purified air from the exhaust port 12. The blower 110 is, for example, a blower fan that generates a swirling flow by rotating a propeller-shaped member. For example, the blower 110 is installed so that the back surface of the blower 110, which is the side that takes in air, faces the intake port 11, and the front surface of the blower 110, which is the side that releases the swirling flow, faces the exhaust port 12. As a result, when the blower 110 operates, a wind is generated inside the housing 13 that swirls and flows from the intake port 11 to the exhaust port 12.

[0019] Inside the housing 13, the light source 120 irradiates the incoming air with vacuum ultraviolet rays (VUV: Vacuum Ultra Violet) to generate ozone. Vacuum ultraviolet rays are light with a wavelength of approximately 10 nm to approximately 200 nm. The light source 120 is, for example, an excimer lamp, a mercury lamp, or the like. When such vacuum ultraviolet rays are irradiated onto the air, ozone is generated. Ozone has a sterilizing and deodorizing effect, and can purify the air.

[0020] The light source 120 is preferably a dual-wavelength light source that irradiates the air to be purified with vacuum ultraviolet light including light with a wavelength of 185 nm and deep ultraviolet light including light with a wavelength of 254 nm. Deep ultraviolet light can cleave nucleic acids such as DNA and RNA that constitute the genes of viruses, bacteria, etc. contained in the air, and sterilize the air by deactivating the viruses, bacteria, etc. An example of such a dual-wavelength light source is a constant-pressure mercury lamp. Constant-pressure mercury lamps emit light stably, have a long life, and are inexpensive, so the cost of the air purification device 10 can be reduced.

[0021] It is desirable that the light source 120 is disposed near the outlet from which the blower 110 discharges the swirling flow. For example, the blower 110 is provided between the intake port 11 and the light source 120, and the light source 120 irradiates the swirling flow generated by the blower 110 with ultraviolet light. In other words, the light source 120 and the blower 110 are disposed so that the air to be purified is irradiated with ultraviolet light in the space behind the blower 110 to generate ozone, and the generated ozone is mixed with the air in the space in front of the blower 110.

[0022] For example, by arranging the blower 110 immediately before the light source 120, a mixed gas of ozone and air can be effectively generated. If ozone remains around the light source 120, oxygen, which is the raw material of ozone, will be insufficient. Therefore, by arranging the blower 110 immediately before the light source 120, the generated ozone can be blown away and air, which is the raw material of ozone, can be appropriately supplied, and ozone can be efficiently generated. The light source 120 may have an optical filter that reduces light of wavelengths different from vacuum ultraviolet light and deep ultraviolet light.

[0023] The light shielding plate 130 shields and reduces light that leaks from the air intake 11 to the outside of the housing 13, among the light emitted by the light source 120. The light shielding plate 130 may also reflect light toward the blower 110 into a space in which the first mixing chamber or the second mixing chamber is present. The light shielding plate 130 is provided, for example, between the blower 110 and the light source 120.

[0024] In this case, the light shielding plate 130 has a reflective surface whose longitudinal section is in the shape of a parabola, an ellipse, a circular arc, or the like. The light shielding plate 130 may also hinder the direction of the air discharged by the blower 110 to generate turbulence, thereby making it easier to mix the ozone and the air. It is desirable that the light shielding plate 130 be made of an aluminum alloy or the like that has a high ultraviolet light reflecting ability.

[0025] The dividing wall 140 divides the space between the light source 120 and the exhaust port 12, where the generated ozone and the inflowing air are mixed by a swirling flow to generate a mixed gas, into a first mixing chamber 150 and a second mixing chamber 160. The dividing wall 140 divides the space where the mixed gas is generated into two regions with different longitudinal velocity components of the swirling flow. In this embodiment, an example will be described in which the dividing wall 140 is provided so that the longitudinal velocity component of the swirling flow in the first mixing chamber 150 is faster than the longitudinal velocity component of the swirling flow in the second mixing chamber 160.

[0026] For example, when the rotation axis of the propeller-shaped member of blower 110 is approximately aligned with or close to the central axis of the longitudinal direction of housing 13, the longitudinal velocity component of the swirling flow is faster in the region including the central axis of the longitudinal direction of housing 13 than in the region on the wall side of housing 13. Therefore, dividing wall 140 is provided so as to divide the space inside housing 13 into a region (first mixing chamber 150) including the central axis of the longitudinal direction of housing 13 and a region (second mixing chamber 160) not including the central axis. In FIG. 1, the central axis of housing 13 in the longitudinal direction is indicated by a dashed line.

[0027] The dividing wall 140 is, for example, a cylindrical partition plate extending in the longitudinal direction of the housing 13. The dividing wall 140 may be provided in the longitudinal direction of the housing 13 so as to move away from the central axis of the longitudinal direction as it approaches the exhaust port 12. In other words, the dividing wall 140 expands in a divergent manner toward the downstream direction of the air flow. Here, the upstream direction is the direction toward the intake port 11, and the downstream direction is the direction toward the exhaust port 12. The dividing wall 140 has, for example, a part of a pyramid shape such as a cone or a polygonal pyramid. In other words, in the longitudinal direction of the housing 13, the volume of the first mixing chamber 150 increases and the volume of the second mixing chamber 160 decreases toward the exhaust port 12.

[0028] In this way, dividing wall 140 is formed so that the air resistance to the longitudinal velocity component of the swirling flow in second mixing chamber 160 is larger than the air resistance to the swirling flow in first mixing chamber 150. This makes it possible to increase the difference between the longitudinal velocity component of the swirling flow in first mixing chamber 150 and the longitudinal velocity component of the swirling flow in second mixing chamber 160. It is preferable that dividing wall 140 is provided so that light from light source 120 reaches first mixing chamber 150 and second mixing chamber 160.

[0029] Furthermore, the dividing wall 140 has through holes 141 for allowing a portion of the swirling flow to flow from the first mixing chamber 150 to the second mixing chamber 160. The through holes 141 allow particles to pass through that are larger than viruses, such as bacteria, mold, and pollen, and are to be sterilized and deodorized. The through holes 141 also allow the light from the light source 120 reflected by the dividing wall 140 in the first mixing chamber 150 to pass through to the second mixing chamber 160.

[0030] Here, the velocity component perpendicular to the longitudinal direction of the swirling flow is a flow that rotates at a nearly constant angular velocity ω from the center to the circumference at a velocity v. In this case, the centrifugal force acting on a particle of mass m located at a distance r from the center is mrω 2 Therefore, the velocity component perpendicular to the longitudinal direction of the swirling flow moves particles with a larger mass from the center of the swirling flow to the outside.

[0031] Therefore, when blower 110 generates a swirling flow, bacteria, mold, pollen, and the like contained in the air in first mixing chamber 150 pass through through-hole 141 and move to second mixing chamber 160 located outside first mixing chamber 150. It is desirable that dividing wall 140 be formed of an aluminum alloy or the like that has a high ultraviolet reflective ability.

[0032] <Example of Cross-Sectional Configuration of Air Purifier 10> Fig. 2 shows an example of the cross-sectional configuration of the air purifying device 10 according to this embodiment. Fig. 2 shows a cross-sectional view taken along line A-A' of the air purifying device 10 shown in Fig. 1. The example in Fig. 2 shows an example in which a dividing wall 140 divides the internal space of the housing 13 into a circular shape.

[0033] The first mixing chamber 150 is provided at a position including the central axis in the longitudinal direction of the housing 13. The second mixing chamber 160 is provided at a position farther away from the central axis in the longitudinal direction of the housing 13 than the first mixing chamber 150. The second mixing chamber 160 is provided so as to surround the periphery of the first mixing chamber 150.

[0034] A part of the inner wall of the housing 13 becomes a part of the wall constituting the second mixing chamber 160. It is desirable that at least a part of the inner wall of the housing 13 is formed of stainless steel or the like that is highly resistant to ozone and ultraviolet light. At least a part of the inner wall of the housing 13 and the surface of the dividing wall 140 facing the second mixing chamber 160 may be further provided with a material that serves as a decomposition catalyst, such as copper oxide or nickel oxide.

[0035] 2, when the cross-sectional shape of the housing 13 is a rectangle, it is desirable that the light source 120 is disposed on a diagonal of the rectangle. This allows the light from the light source 120 to reach the first mixing chamber 150 and the second mixing chamber 160 while keeping the size of the housing 13 compact.

[0036] The swirling flow generated by blower 110 becomes a vortex air flow centered on the central axis in the longitudinal direction, for example, on the XY plane. The vortex air flow has an outward flow component from the central axis in the longitudinal direction toward the periphery of the central axis, so bacteria, mold, pollen, etc. contained in the air can easily move through through-holes 141 to second mixing chamber 160.

[0037] As an example, if the diameter of the fan of blower 110 is about 12 cm and the fan is rotated at about 3000 revolutions per minute, the centrifugal force generated at the tip of the fan is about 600 G. Since the rotation speed of the swirling flow generated by the fan is estimated to be about 1 / 6 the rotation speed of the fan, the centrifugal force of the swirling flow is considered to be about 100 G.

[0038] Since the mass of particles such as bacteria, mold, and pollen is about 10,000 times that of air molecules, a centrifugal force of about 100 G can separate bacteria, mold, pollen, and viruses and odor molecules that are lighter than air molecules by centrifugation. In other words, most of the particles such as bacteria, mold, and pollen can be moved to the second mixing chamber 160. Furthermore, the viruses and odor molecules are distributed to the first mixing chamber 150 and the second mixing chamber 160 in a roughly volumetric ratio.

[0039] As described above, the first mixing chamber 150 has a higher swirling flow velocity than the second mixing chamber 160, and serves as a space in which a mixture of ozone and air to be purified, which contains viruses, odor-causing molecules, etc., swirls. The second mixing chamber 160 has a lower swirling flow velocity than the first mixing chamber 150, and serves as a space in which a mixture of ozone and air, which contains bacteria, mold, pollen, etc., in addition to viruses and odor-causing molecules, swirls.

[0040] In the first mixing chamber 150 and the second mixing chamber 160, the mixed gas swirls, so that the air to be purified and the ozone are mixed almost uniformly. As a result, at least a part of the air to be purified is purified by the ozone. In addition, when the light source 120 is a two-wavelength light source, the deep ultraviolet light can destroy the activity of viruses, bacteria, etc. in the first mixing chamber 150 and the second mixing chamber 160, thereby sterilizing them.

[0041] In addition, the dividing wall 140 is formed with a through hole 141 that passes the light of the light source 120 from the first mixing chamber 150 to the second mixing chamber 160. As a result, even if the second mixing chamber 160 is a narrower space than the first mixing chamber 150 and the opening of the second mixing chamber 160 facing the light source 120 is smaller than the opening of the first mixing chamber 150 facing the light source 120, it is possible to obtain an amount of light sufficient to sterilize viruses, bacteria, and the like.

[0042] Furthermore, deep ultraviolet rays decompose ozone to generate active oxygen (OH radicals) that have a high sterilizing effect. In other words, deep ultraviolet rays can sterilize and deodorize the air while reducing the concentration of ozone. As described above, the air purifier 10 can purify at least a portion of the air contained in the mixed gas in the first mixing chamber 150 and the second mixing chamber 160 by ozone, sterilizing rays, and active oxygen.

[0043] The mixed gas generated inside the housing 13 flows into the ozone decomposition catalyst 170 from the first mixing chamber 150 and the second mixing chamber 160 due to the swirling flow. The ozone decomposition catalyst 170 decomposes ozone to generate active oxygen, and the generated active oxygen purifies the air contained in the mixed gas. The active oxygen can sterilize and deodorize the air more quickly than ozone, etc. In addition, the active oxygen disappears more quickly than ozone, etc., so it hardly flows out to the outside of the air purifier 10.

[0044] In other words, the ozone decomposition catalyst 170 reduces the concentration of ozone contained in the mixed gas and generates active oxygen with a high sterilizing effect. Mold, bacteria, etc. have DNA, and viruses, etc. have RNA. Active oxygen has the ability to cleave such DNA and RNA, so it can sterilize mold, bacteria, viruses, etc. The ozone decomposition catalyst 170 decomposes ozone on the surface that comes into contact with ozone, so it is desirable for the catalyst to have a structure with a large surface area. The ozone decomposition catalyst 170 is configured to have, for example, a plurality of through holes and decompose ozone when the mixed gas passes through each of the through holes.

[0045] The cross section of the through hole is desirably a circle, an ellipse, a polygon, or the like. When the cross section of the through hole is circular, it is desirably formed so that the diameter of the circle is about 1 mm. When the cross section of the through hole is other than circular, it is desirably formed so that the cross section area is about the area of ​​a circle with a diameter of 1 mm. A catalyst such as manganese dioxide or nickel oxide is fixed to the inner wall of the through hole.

[0046] Ozone is decomposed on the inner wall of the through hole to generate active oxygen, which oxidizes and decomposes organic matter and then returns to oxygen. The particles to be sterilized and deodorized that flow into the through hole are reflected off the inner wall of the through hole many times due to the swirling flow, increasing the chance of contacting the generated active oxygen and efficiently purifying the particles in the through hole. In other words, the concentration of active oxygen is high near the inner wall of the through hole, and the air is purified near the inner wall of the through hole. The lifespan of active oxygen is about 1 / 10,000 seconds, and the distance that active oxygen travels is estimated to be about 20 μm.

[0047] As an example, the ozone decomposition catalyst 170 has a honeycomb structure in which the cross section of the through holes is a regular hexagon. This allows the ozone decomposition catalyst 170 to maintain the breathability that allows the purified air to pass through to the exhaust port 12 while increasing the contact area between the ozone and the catalyst, and thus allows the ozone to be efficiently decomposed.

[0048] The mixed gas in the first mixing chamber 150 reaches the ozone decomposition catalyst 170 faster than the mixed gas in the second mixing chamber 160. For example, if the longitudinal moving speed of the mixed gas in the first mixing chamber 150 is about 1 m / s and the rotation speed of the swirling flow is about 300 rpm (= 50 rpm), the horizontal velocity component perpendicular to the longitudinal direction is about 18 m / s.

[0049] In other words, it can be seen that the mixed gas in the first mixing chamber 150 can enter the wall surface of the through hole of the ozone decomposition catalyst 170 at an angle close to perpendicular, effectively generating active oxygen. As a result, the ozone concentration in the mixed gas decreases, and the air in the mixed gas is purified by the active oxygen, while the horizontal kinetic energy is converted into linear energy proceeding along the through hole toward the exhaust port 12, and the swirling flow that has flowed into the ozone decomposition catalyst 170 becomes a straight flow and proceeds toward the exhaust port 12.

[0050] As described above, the air purifier 10 can efficiently enhance the reaction between ozone and the ozone decomposition catalyst 170 by generating a swirling flow with the blower 110, and can also improve the ventilation capacity for exhausting the air that has passed through the ozone decomposition catalyst 170 from the exhaust port 12. Meanwhile, the mixed gas in the second mixing chamber 160 moves slower in the longitudinal direction toward the ozone decomposition catalyst 170 than the mixed gas in the first mixing chamber 150, and therefore passes through the ozone decomposition catalyst 170 at a slower speed. This lengthens the time that the air contained in the mixed gas in the second mixing chamber 160 passes through the ozone decomposition catalyst 170, and the active oxygen can effectively sterilize the air over time.

[0051] The activated carbon filter 180 is provided between the ozone decomposition catalyst 170 and the exhaust port 12, and the air purified by the ozone decomposition catalyst 170 flows in by a swirling flow, and decomposes the ozone remaining in the air. The exhaust port 12 exhausts the air purified by passing through the activated carbon filter 180 by a swirling flow. Note that while the ozone decomposition catalyst 170 can reduce ozone to a sufficiently low concentration, the activated carbon filter 180 removes the remaining ozone when a trace amount of ozone remains in the air that flows in, and reliably reduces the concentration of ozone leaking outside the air purifier 10.

[0052] The ozone decomposition capacity of the activated carbon filter 180 is determined approximately by the amount of activated carbon and the flow rate of the inflowing air. As an example, the activated carbon filter 180 can be designed to reduce the residual ozone concentration by about 95% or more using activated carbon, so that the concentration of ozone exhausted from the exhaust port 12 is about 0.05 ppm or less. In other words, the air purifier 10 according to this embodiment can purify the air by using the ozone decomposition catalyst 170 and the activated carbon filter 180 to reduce the residual ozone concentration to about 0.05 ppm or less, which is safe for the human body.

[0053] The ozone sensor 190 is provided between the ozone decomposition catalyst 170 and the activated carbon filter 180, and detects the concentration of ozone. It is desirable for the air purifier 10 to be able to monitor that safe air is being exhausted, and for example, it is desirable to be able to detect the concentration of ozone exhausted from the exhaust port 12. However, an ozone detector that detects an ozone concentration of less than about 0.03 ppm is expensive, and the device size is large.

[0054] Therefore, in the air purifying device 10 according to this embodiment, the ozone sensor 190 is disposed between the ozone decomposition catalyst 170 and the activated carbon filter 180. The ozone sensor 190 detects whether or not the concentration of ozone flowing in from the ozone decomposition catalyst 170 has been sufficiently reduced. For example, the ozone sensor 190 detects whether or not the concentration of ozone is about 0.3 ppm or less.

[0055] The ozone sensor 190 is, for example, an element using indium-tin composite oxide. Such an ozone sensor 190 has high sensitivity to ozone in the concentration range of about 0.02 ppm to about 0.5 ppm, and can detect ozone at a concentration of 0.06 ppm or less as stipulated in the Basic Law for the Environment.

[0056] The control unit 200 calculates the ozone concentration upon receiving the detection result of the ozone sensor 190. The control unit 200 may output the calculated ozone concentration to a display unit or the like, or may transmit information on the ozone concentration to a server or a user's terminal or the like via a network or the like.

[0057] The control unit 200 estimates the residual ozone concentration contained in the air exhausted from the exhaust port 12, for example, by subtracting a predetermined value from the detection result of the ozone sensor 190 or by multiplying the detection result by a predetermined coefficient. Here, the predetermined value or the predetermined coefficient is a value based on at least one of the ozone decomposition capabilities of the ozone decomposition catalyst 170 and the activated carbon filter 180.

[0058] For example, the predetermined value or the predetermined coefficient is the amount of ozone that is reduced by decomposition in the activated carbon filter 180. In addition, when the ozone decomposition ability of the ozone decomposition catalyst 170 is sufficiently high and the ozone concentration can be reduced to below the detection limit of the ozone sensor 190, the detection result of the ozone sensor 190 becomes larger than the actual ozone concentration. Therefore, the predetermined value or the predetermined coefficient can be determined by measuring the ozone decomposition ability of the ozone decomposition catalyst 170 in advance and measuring the tendency of the error between the detection result of the ozone sensor 190 and the actual ozone concentration.

[0059] This allows the minimum sensitivity of ozone sensor 190 to be greater than the allowable residual ozone concentration contained in the air exhausted from exhaust port 12. For example, the air purifier 10 can use, as ozone sensor 190, an inexpensive ozone detector with an ozone concentration detection sensitivity of approximately 0.03 ppm to 0.5 ppm.

[0060] Furthermore, the control unit 200 may control each component of the air purifying device 10, such as the blower 110 and the light source 120. For example, based on the result of detection of the ozone concentration by the ozone sensor 190, the control unit 200 adjusts the flow rate of the swirling flow of the blower 110 so that the detection result of the ozone concentration becomes equal to or less than a predetermined value.

[0061] For example, the control unit 200 reduces the rotation speed of the motor of the blower 110 when the concentration of ozone is higher than a first threshold. The control unit 200 may increase the rotation speed of the motor when the concentration of ozone is lower than a second threshold. The second threshold is a value smaller than the first threshold. Furthermore, the control unit 200 may return the rotation speed of the motor to an initial value when the concentration of ozone returns to a value between the first and second thresholds.

[0062] Alternatively, the control unit 200 may adjust the timing of turning on and off the light source 120 or the amount of light based on the ozone concentration detection result by the ozone sensor 190 so that the ozone concentration detection result is equal to or lower than a predetermined value. For example, when the ozone concentration is higher than a first threshold and the light source 120 is on, the control unit 200 turns off the light source 120 to reduce the amount of ozone generated. The control unit 200 adjusts the on and off times of the light source 120, and may shorten the time that the light source 120 is on when the ozone concentration is higher than the first threshold.

[0063] When the ozone concentration is lower than the second threshold, the control unit 200 may turn on the light source 120, or may alternatively extend the time for which the light source 120 is turned on. Furthermore, when the ozone concentration returns to a value between the first and second thresholds, the control unit 200 may return the control method for the light source 120 to the initial value.

[0064] Alternatively, the control unit 200 may control the blower 110 and the light source 120 based on the detection result of the ozone concentration. For example, when the ozone concentration is higher than a first threshold and the light source 120 is turned on, the control unit 200 turns off the light source 120 while reducing the rotation speed of the motor of the blower 110. Here, the control unit 200 may extend the time for which the light source 120 is turned off. When the ozone concentration is lower than a second threshold, the control unit 200 turns on the light source 120 without changing the rotation speed of the motor of the blower 110.

[0065] The control unit 200 may reduce the rotation speed of the motor of the blower 110 when the concentration of ozone is lower than a third threshold value. Here, the third threshold value is a value smaller than the second threshold value. Furthermore, the control unit 200 may reset the control method of the blower 110 and the light source 120 to the initial value when the concentration of ozone returns to a value between the first threshold value and the second threshold value.

[0066] Alternatively or in addition, the control unit 200 may decrease the amount of light from the light source 120 when the concentration of ozone is higher than a first threshold. The control unit 200 may, for example, supply to the light source 120 a control signal for increasing or decreasing the value of the current driving the light source 120. The control unit 200 may increase the amount of light from the light source 120 when the concentration of ozone is lower than a second threshold. Furthermore, the control unit 200 may return the amount of light from the light source 120 to the initial value when the concentration of ozone returns to a value between the first and second thresholds.

[0067] The control unit 200 may be configured with a CPU, a storage unit, and the like. For example, when a computer functions as the control unit 200, the storage unit stores information such as an OS (Operating System) that causes the computer to function, and programs. The storage unit may also store various information including a database that is referenced when the program is executed. For example, the computer functions as the control unit 200 by executing the program stored in the storage unit.

[0068] The storage unit includes at least one of, for example, a Read Only Memory (ROM) that stores various programs, data, various tables, etc. executed by a computer, an Erasable Programmable Read Only Memory (EPROM) such as an Electrically Erasable Programmable Read Only Memory (EEPROM), a Random Access Memory (RAM) that serves as a working area, etc. The storage unit may also include a large-capacity storage device such as a Hard Disk Drive (HDD) and / or a Solid State Drive (SSD).

[0069] As described above, the air purifying device 10 according to this embodiment generates a swirling flow inside the housing 13, and purifies the air in each of the two mixing chambers where the flow speed of the swirling flow is different. The longitudinal flow speed of the swirling flow is faster in the first mixing chamber 150 than in the second mixing chamber 160. As a result, the longitudinal movement speed of the mixed gas moving from the first mixing chamber 150 to the ozone decomposition catalyst 170 is faster than the longitudinal movement speed of the mixed gas moving from the second mixing chamber 160 to the ozone decomposition catalyst 170.

[0070] As described above, bacteria, mold, pollen, etc. move from the first mixing chamber 150 to the second mixing chamber 160, so the air to be purified in the first mixing chamber 150 contains relatively small particles to be sterilized and deodorized, such as viruses, molecules that are the source of odors, etc. Such particles to be sterilized and deodorized can be sterilized and deodorized in a short time compared to bacteria, mold, pollen, etc. Therefore, the air purifier 10 swiftly purifies at least a portion of the viruses, molecules that are the source of odors, etc., in the first mixing chamber 150, where the longitudinal movement speed of the mixed gas is high, using ozone, deep ultraviolet light, etc., and supplies them to the ozone decomposition catalyst.

[0071] On the other hand, the air to be purified in the second mixing chamber 160 contains bacteria, mold, pollen, etc., and therefore contains relatively large particles to be sterilized and deodorized. Such particles to be sterilized and deodorized take time to sterilize and deodorize compared to viruses, etc. Therefore, the air purifier 10 purifies at least a portion of the bacteria, mold, pollen, etc. over time in the second mixing chamber 160, where the longitudinal movement speed of the mixed gas is slow, using ozone, deep ultraviolet light, etc., and supplies them to the ozone decomposition catalyst.

[0072] As described above, the air purifier 10 separates the particles to be sterilized and deodorized, which take a relatively long time to purify, from the particles to be sterilized and deodorized, which can be purified relatively quickly, by using a swirling flow, and collects them in the second mixing chamber 160. This allows the air purifier 10 to purify and exhaust the particles to be sterilized and deodorized in a time period corresponding to the size of the particles. Furthermore, the air purifier 10 can purify the air by effectively generating active oxygen in the ozone decomposition catalyst 170. Therefore, the air purifier 10 can purify more air efficiently at low cost.

[0073] <An example of an operation flow of the air purifier 10> 3 shows an example of the operation flow of the air purifying device 10 according to this embodiment. For example, the air purifying device 10 is installed in a room filled with air to be purified. In addition, the operations of the ozone sensor 190 and the control unit 200 have already been described, so a description thereof will be omitted here.

[0074] First, the control unit 200 operates the blower 110 and turns on the light source 120. The control unit 200 rotates the blower fan at a predetermined rotation speed, for example. This causes the blower 110 to generate a swirling flow that causes the air to be purified to flow from the intake port 11 into the inside of the housing 13 (S51). Furthermore, the light source 120 irradiates the air that has flowed in with vacuum ultraviolet light inside the housing 13 to generate ozone (S52).

[0075] Next, in the first mixing chamber 150 and the second mixing chamber 160 inside the housing 13, the generated ozone and the inflowing air are mixed by a swirling flow to generate a mixed gas (S53). Then, a part of the swirling flow flows from the first mixing chamber 150 to the second mixing chamber 160 through the through-hole 141 of the dividing wall 140, and particles such as bacteria, mold, and pollen are moved to the second mixing chamber 160 (S54).

[0076] Then, in the first mixing chamber 150, the air contained in the mixed gas generated in the first mixing chamber 150 is sterilized by the ozone and deep ultraviolet light, and the mixed gas is caused to flow into the ozone decomposition catalyst 170 by the swirling flow (S55). This generates active oxygen that decomposes ozone, and the air contained in the mixed gas is purified by the generated active oxygen.

[0077] In addition, in the second mixing chamber 160, the mixed gas generated in the first mixing chamber 150 by the ozone and deep ultraviolet light and the mixed gas flowing from the first mixing chamber 150 through the through hole 141 into the second mixing chamber 160 are sterilized, while the mixed gas is caused to flow into the ozone decomposition catalyst 170 by the swirling flow (S56). This generates active oxygen that decomposes ozone, and the air contained in the mixed gas is purified by the generated active oxygen.

[0078] As a result, in the space between the ozone decomposition catalyst 170 and the activated carbon filter 180, the air purified through the ozone decomposition catalyst 170 from the first mixing chamber 150 and the air purified through the ozone decomposition catalyst 170 from the second mixing chamber 160 join together.

[0079] Here, the dividing wall 140 is provided so that the longitudinal movement speed of the mixed gas moving from the second mixing chamber 160 to the ozone decomposition catalyst 170 is smaller than the longitudinal movement speed of the mixed gas moving from the first mixing chamber 150 to the ozone decomposition catalyst 170. Therefore, of the joined air, most of the air that joined from the second mixing chamber 160 is air that flowed into the second mixing chamber 160 at an earlier time than the air that joined from the first mixing chamber 150.

[0080] Next, the air purified by the ozone decomposition catalyst 170 is caused to flow into the activated carbon filter 180 by the swirling flow, and the ozone remaining in the air is decomposed (S57). The purified air is then exhausted from the exhaust port 12 by the swirling flow (S58). The air purifier 10 continues the above operations to purify the air filling the room.

[0081] <Other Configuration Examples of the Air Purifier 10> The air purifying device 10 according to the present embodiment has been described above as an example in which the air is purified by ozone, deep ultraviolet light, or the like in the second mixing chamber 160, but is not limited thereto. For example, the second mixing chamber 160 may further include a humidifier for humidifying the second mixing chamber 160.

[0082] It is known that moisture is involved in the decomposition of ozone. In particular, it is known that water vapor with the same amount of ozone can efficiently generate hydroxyl radicals, which have strong oxidizing power. Therefore, the humidifier can efficiently purify bacteria, mold, pollen, etc. by increasing the humidity of the mixed gas in the second mixing chamber 160 and supplying it to the ozone decomposition catalyst 170.

[0083] Here, the molecular weight of ozone is 48, and that of water is 18. For example, a 4W constant pressure mercury lamp generates about 5mg of ozone per hour, so if a humidifier outputs about 40mg of water per hour, which is equivalent to one drop of water, it can supply about 50 times the amount of water molecules as ozone. It is desirable for the humidifier to be able to output water in the form of droplets with a small surface area to suppress evaporation.

[0084] Here, if the humidifier is operated according to the above calculation, the amount of water supplied by the humidifier is only about 180cc in six months. In this case, the water in the tank of the humidifier may become spoiled. Therefore, it is preferable that the humidifier is configured so that the air in the tank can be replaced with ozone. The humidifier may also use hydrogen peroxide instead of water.

[0085] If the air purifying device 10 includes a humidifier, the control unit 200 may control the humidifier. For example, the control unit 200 may adjust the operation of the humidifier based on the result of detection of the ozone concentration by the ozone sensor 190 so that the detection result of the ozone concentration becomes equal to or less than a predetermined value.

[0086] For example, the control unit 200 may increase the amount of water supplied by the humidifier when the concentration of ozone is higher than a first threshold. The control unit 200 may reduce the amount of water supplied by the humidifier when the concentration of ozone is lower than a second threshold. Furthermore, the control unit 200 may return the amount of water supplied by the humidifier to an initial value when the concentration of ozone is between the first threshold and the second threshold.

[0087] In the air purifying device 10 according to the present embodiment, an example has been described in which the dividing wall 140 has a partial cone shape, but the present invention is not limited to this. For example, the cross-sectional shape perpendicular to the longitudinal direction of the dividing wall 140 may be an ellipse, or alternatively, a polygonal shape with rounded corners. Here, when the cross-sectional shape is a polygon, it is preferable that the number of vertices is an odd number of three or more, such as a pentagon.

[0088] Also, the center position of the light source 120 may be shifted by a predetermined distance from the central axis of the housing 13 in the longitudinal direction. Alternatively, the central axis of the dividing wall 140 may be shifted by a predetermined distance from the central axis of the housing 13 in the longitudinal direction. With these configurations, it is possible to reduce uneven distribution of ultraviolet light caused by multiple reflections of light inside the first mixing chamber 150, etc.

[0089] Furthermore, the surface of the dividing wall 140 facing the first mixing chamber 150 may be provided with recesses and / or protrusions that do not impede the swirling flow (to the extent that air resistance is hardly increased). Such recesses, protrusions, etc. generate vortices smaller than the swirling flow, and capture and convect fine particles, etc. This allows for the purification of such fine particles over time, even if fine particles larger than viruses remain in the first mixing chamber 150.

[0090] On the other hand, a concave portion and / or a convex portion may be provided on the surface of dividing wall 140 facing second mixing chamber 160 so as to increase the air resistance of the swirling flow. Also, a concave portion and / or a convex portion may be provided on the surface constituting second mixing chamber 160 of housing 13 (the surface of housing 13 facing second mixing chamber 160).

[0091] Alternatively or in addition, plate-like members for increasing the air resistance of the swirling flow may be provided on the partition wall 140 and the surface of the housing 13 facing the second mixing chamber 160. FIG. 4 shows a modified example of the air purifying device 10 according to this embodiment. The modified air purifying device 10 shows an example in which plate-like members 142 are provided on the partition wall 140 and the surface of the housing 13 facing the second mixing chamber 160. In this way, by increasing the air resistance of the second mixing chamber 160, it is possible to reduce the longitudinal velocity component of the swirling flow or adjust the longitudinal velocity component of the swirling flow to an appropriate value.

[0092] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. For example, all or part of the device can be configured by distributing or integrating functionally or physically in any unit. In addition, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effect of the new embodiment resulting from the combination combines the effect of the original embodiment. [Explanation of symbols]

[0093] 10. Air Purifier 11 Air Intake 12 Exhaust port 13. Cabinet 14 Filters 110 Blower 120 light source 130 Shade 140 dividing wall 141 Through hole 142 Plate-shaped members 150 1st mixing room 160 2nd mixing room 170 Ozone decomposition catalyst 180 Activated Charcoal Filter 190 Ozone Sensor 200 Control section

Claims

1. a housing having an intake port and an exhaust port; a blower that generates a swirling flow that causes the air to be purified to flow into the housing through the intake port and exhausts the purified air through the exhaust port; a light source configured to irradiate the air that has flowed in inside the housing with vacuum ultraviolet light to generate ozone; a partition wall that partitions a space between the light source and the exhaust port, in which the generated ozone and the inflowing air are mixed by the swirling flow to generate a mixed gas, into a first mixing chamber and a second mixing chamber; an ozone decomposition catalyst into which the generated mixed gas flows due to the swirling flow, which decomposes the ozone to generate active oxygen, and which purifies the air contained in the mixed gas with the generated active oxygen; Equipped with The dividing wall is a space in which the mixed gas is generated is divided into two regions, and a longitudinal moving speed of the mixed gas moving from the second mixing chamber to the ozone decomposition catalyst is set to be smaller than a longitudinal moving speed of the mixed gas moving from the first mixing chamber to the ozone decomposition catalyst, A through hole for allowing a portion of the swirling flow to flow from the first mixing chamber to the second mixing chamber. Air purifier.

2. The housing has a cylindrical shape with a longitudinal direction extending from the intake port to the exhaust port, The second mixing chamber is provided at a position farther from the central axis of the housing in the longitudinal direction than the first mixing chamber.

2. The air purifying device according to claim 1.

3. 10. The air purification device of claim 1, further comprising a humidifier for humidifying the second mixing chamber.

4. 2. The air purifying device according to claim 1, wherein the light source irradiates the air with the vacuum ultraviolet light containing light having a wavelength of 185 nm and the deep ultraviolet light containing light having a wavelength of 254 nm.

5. 2. The air purifying device of claim 1, further comprising a light shielding plate that blocks and reduces light emitted by the light source that leaks from the air intake port to the outside of the housing, while reflecting light directed toward the blower into a space in which the first mixing chamber or the second mixing chamber is located.

6. 6. The air purifying device according to claim 1, further comprising an ozone sensor disposed between the ozone decomposition catalyst and the exhaust port, the ozone sensor detecting a concentration of the ozone.

7. 7. The air purifying device of claim 6, further comprising a control unit that adjusts at least one of a flow rate of the swirling flow of the blower, a timing of turning on and off the light source, and an amount of light of the light source, based on a detection result of the ozone concentration by the ozone sensor, so that the detection result of the ozone concentration becomes equal to or less than a predetermined value.

8. A method for purifying air using a housing having an air intake and an exhaust port facing the air intake, comprising: generating a swirling flow that causes the air to be purified to flow from the air intake into the housing; generating ozone by irradiating the air that has flowed in inside the housing with vacuum ultraviolet light; A step of mixing the generated ozone and the air that has flowed in by the swirling flow in a first mixing chamber and a second mixing chamber inside the housing to generate a mixed gas; a partition wall dividing the first mixing chamber and the second mixing chamber, the partition wall having a through hole, allowing a portion of the swirling flow to flow from the first mixing chamber to the second mixing chamber; a step of causing the mixed gas generated in the first mixing chamber to flow into an ozone decomposition catalyst by the swirling flow to generate active oxygen that decomposes the ozone, and purifying the air contained in the mixed gas with the generated active oxygen; a step of causing the mixed gas generated in the second mixing chamber and the mixed gas flowing from the first mixing chamber through the through hole to flow into the ozone decomposition catalyst by the swirling flow to generate active oxygen that decomposes the ozone, and purifying the air contained in the mixed gas with the generated active oxygen; discharging the purified air from the exhaust port by the swirling flow; having the partition wall divides the space in which the mixed gas is generated into two regions, and is provided so that a longitudinal moving speed of the mixed gas moving from the second mixing chamber to the ozone decomposition catalyst is smaller than a longitudinal moving speed of the mixed gas moving from the first mixing chamber to the ozone decomposition catalyst. The air purification method.

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