Air treatment device

Abstract

The invention provides an air treatment device which uses ultraviolet rays in a treatment space to efficiently carry out sterilization. According to an embodiment, an air treatment device includes a housing, a fan, and an ultraviolet light source. In the housing, a processing space is formed in an air path from the introduction port to the discharge port, and in the processing space, the cross-sectional area orthogonal to the air flow direction is uniform. The fan forms an air flow from the introduction port to the discharge port at a flow rate of 1 m3 / min or more in the processing space. The ultraviolet light source emits ultraviolet light into the processing space in a state in which the radiation flow per 1 m2 in a cross-section orthogonal to the flow direction of the air is 6000 mW / m2 or more.

Description

Technical Field

[0001] An embodiment of the present invention relates to an air treatment device. Background Art

[0002] Air treatment devices that use ultraviolet rays to sterilize air are known. In such air treatment devices, a treatment space is formed inside a frame, and external air is introduced into the frame from an inlet. In addition, ultraviolet rays from an ultraviolet light source are irradiated in the treatment space to sterilize the introduced air. In addition, the air sterilized by ultraviolet rays is discharged from an outlet to the outside of the frame.

[0003] In the air treatment device as described above, it is required to reduce the radiation amount of ultraviolet rays from the ultraviolet light source or the amount of heat generated as much as possible within the range of maintaining sterilization performance so as to perform air treatment efficiently.

[0004] [Prior art literature]

[0005] [Patent Document]

[0006] Patent Document 1: Japanese Patent Application Publication No. 2015-51268 Summary of the invention

[0007] [Problems to be solved by the invention]

[0008] An object of the present invention is to provide an air treatment device that efficiently sterilizes a treatment space using ultraviolet rays.

[0009] [Technical means to solve the problem]

[0010] According to an embodiment, an air treatment device includes a frame, a fan, and an ultraviolet light source. The frame is provided with an inlet for introducing air into the interior and an outlet for exhausting air to the exterior, and a treatment space is formed in the air path from the inlet to the outlet. In the treatment space, the cross-sectional area perpendicular to the flow direction of the air is uniform. The fan is operated to generate a uniform cross-sectional area of ​​1 m2 in the treatment space. 3 The air flow from the inlet to the outlet is formed at a flow rate of more than / min. The ultraviolet light source is operated so that every 1m 2 The radiation flux is 6000mW / m 2 In the above state, ultraviolet rays are radiated to the processing space.

[0011] [Effects of the Invention]

[0012] According to the present invention, it is possible to provide an air treatment device that efficiently sterilizes a treatment space using ultraviolet rays. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram showing an example of an air treatment device according to an embodiment.

[0014] Figure 2 This is a schematic diagram showing the measurement results of the air flow rate and the time until 99% sterilization is achieved for each of the five test conditions of the first verification in a table.

[0015] Figure 3 This is a schematic diagram showing in a graph the relationship between the air flow rate and the measurement results of the time required to achieve 99% sterilization in the first verification.

[0016] Figure 4 This is a schematic diagram showing, in a table, the measurement results of the ultraviolet radiation flux per unit area and the time required to achieve 99% sterilization for each of the six test conditions of the second verification.

[0017] Figure 5 This is a schematic diagram showing in a graph the relationship between the radiation flux of ultraviolet rays per unit area and the measurement results of the arrival time until 99% sterilization in the second verification.

[0018] Figure 6 This is a schematic diagram showing an example of a relationship between the peak wavelength of ultraviolet rays and the inactivation sensitivity in a table.

[0019] Figure 7 It is represented by a graph Figure 6 A schematic diagram showing an example of the relationship between the peak wavelength of ultraviolet light and the inactivation sensitivity.

[0020] [Explanation of Symbols]

[0021] 1: Air handling unit

[0022] 2: Frame

[0023] 3: Import port

[0024] 5: Exhaust port

[0025] 6: Fan

[0026] 13: UV light source

[0027] 15: Processing Space DETAILED DESCRIPTION

[0028] The air treatment device 1 of the embodiment includes a frame 2, a fan 6 and an ultraviolet light source 13. The frame 2 is provided with an inlet 3 for introducing air into the interior and an outlet 5 for exhausting air to the exterior, and a processing space 15 is formed in the air path from the inlet 3 to the outlet 5. In the processing space 15, the cross-sectional area perpendicular to the flow direction of the air is uniform. The fan 6 is operated to generate a uniform cross-sectional area of ​​1 m2 in the processing space 15. 3 The air flow from the inlet 3 to the outlet 5 is formed at a flow rate of more than 1 / min. The ultraviolet light source 13 is operated so that the air flow is 1 m / s on a cross section perpendicular to the air flow direction. 2 The radiation flux is 6000mW / m 2 In the above state, ultraviolet rays are irradiated to the processing space 15. Thus, the processing space 15 can be sterilized appropriately using ultraviolet rays, and the heat generation in the ultraviolet light source 13 can be effectively suppressed, thereby realizing efficient air processing.

[0029] In the air treatment device 1 of the embodiment, the ultraviolet light source 13 is operated to generate a light beam every 1 m. 2 The radiation flux is 20000mW / m 2 In the following state, ultraviolet rays are radiated to the processing space 15. It is possible to effectively prevent the ultraviolet light source 13 from generating excessive heat in a range that does not contribute to the improvement of air processing performance, thereby achieving efficient air processing.

[0030] In the air treatment device 1 of the embodiment, the ultraviolet light source 13 is operated to radiate ultraviolet light with a peak wavelength of 280 nm to the treatment space 15. 3 / min or more and the ultraviolet radiation flux per unit area on the cross section perpendicular to the flow direction is set to 6000mW / m 2 As described above, air treatment including air sterilization can be appropriately performed with high performance.

[0031] Hereinafter, embodiments and the like will be described with reference to the drawings.

[0032] Figure 1 An example of the air treatment device 1 according to the embodiment is shown. Figure 1 In an example of an air treatment device 1, a height direction (direction indicated by arrow X), a width direction (direction indicated by arrow Y) intersecting (orthogonal or substantially orthogonal) the height direction, and a depth direction (direction indicated by arrow Y) intersecting (orthogonal or substantially orthogonal) both the height direction and the width direction are defined. Figure 1 in a direction perpendicular or approximately perpendicular to the plane of the paper). Figure 1 It shows a cross section which is perpendicular or substantially perpendicular to the depth direction.

[0033] like Figure 1 As shown, the air treatment device 1 includes a frame 2, and an internal cavity is formed inside the frame 2. Therefore, in the air treatment device 1, the frame 2 forms an exterior. An inlet 3 and an outlet 5 are formed in the frame 2. The internal cavity of the frame 2 opens to the outside of the frame 2 at the inlet 3 and the outlet 5, respectively. Figure 1 In one example, the inlet port 3 is formed on one end surface of the frame 2 in the height direction. In addition, the outlet port 5 is formed on the end surface of the frame 2 on the opposite side to the inlet port 3 in the height direction.

[0034] A fan 6 is disposed in the hollow interior of the housing 2 . Figure 1 In one example, the fan 6 is arranged in a state facing the exhaust port 5 from the inside, and an exhaust fan is used as the fan 6. When the air treatment device 1 is used, the fan 6 is operated. By operating the fan 6, external air is introduced from the inlet 3 to the internal cavity inside the frame 2. In addition, inside the frame 2, an air flow from the inlet 3 toward the exhaust port 5 is formed. In addition, air is exhausted from the internal cavity to the outside of the frame 2 through the exhaust port 5.

[0035] In the state where the air flow is formed as described above, the direction from the inlet 3 toward the outlet 5 in the internal cavity of the frame 2 is the flow direction of the air (the direction indicated by the arrow F). Figure 1 In one example, the flow direction of the air in the internal cavity is along the height direction of the air treatment device 1. Moreover, in the internal cavity of the frame 2, the flow direction of the air, that is, the side toward the exhaust port 5, is defined as the downstream side. Moreover, in the internal cavity of the frame 2, the direction opposite to the flow direction of the air, that is, the side toward the inlet 3, is defined as the upstream side. Hereinafter, expressions such as upstream (side) and downstream (side) mean the upstream (side) and downstream (side) relative to the air flow.

[0036] Figure 1 In one example, in the internal cavity of the frame 2, a shading grille 11, a pre-filter 12, an ultraviolet light source 13 and a fan 6 are arranged in order from the upstream side. In another example, in the internal cavity, the fan 6 is arranged on the upstream side relative to the shading grille 11. At this time, the fan 6 is arranged in a state facing the inlet 3 from the inside, and an intake fan is used as the fan 6. In the structure using the intake fan as the fan 6, in the internal cavity of the frame 2, an air flow from the inlet 3 toward the outlet 5 is also formed by the operation of the fan 6. In addition, Figure 1 The air flow direction F shown is an example, and the air flow direction may be the opposite direction to F. In this case, Figure 1 The opening of the inlet 3 in the tube functions as a discharge port. Figure 1 The opening of the discharge port 5 in the chamber functions as an introduction port.

[0037] and, Figure 1 In one example, in the internal cavity of the frame 2, a processing space 15 is formed between the ultraviolet light source 13 and the pre-filter 12 in the height direction. The processing space 15 is formed on the air path from the inlet 3 to the outlet 5. When the air treatment device 1 is used, the air introduced into the frame 2 is treated in the processing space 15 using ultraviolet rays. Figure 1 In one example, the ultraviolet light source 13 is adjacent to the processing space 15 from the downstream side, and the prefilter 12 is adjacent to the processing space 15 from the upstream side.

[0038] In one example, the size of the processing space 15 along the height direction, that is, the distance between the ultraviolet light source 13 and the pre-filter 12 with respect to the height direction is greater than 50 mm and less than 1000 mm. In the air treatment device 1, the imaginary central plane, which is the central position of the frame 2 with respect to the height direction, is located in the processing space 15 and is located between the ultraviolet light source 13 and the pre-filter 12. That is, the processing space 15 is configured in a manner that overlaps with the center of the height direction of the air treatment device 1. Moreover, in the processing space 15, the cross-sectional area perpendicular to the flow direction of the air is uniform. That is, in the processing space 15, the cross-sectional area perpendicular to the height direction of the air treatment device 1 is fixed or approximately fixed from the upstream end to the downstream end. The processing space 15 is, for example, a rectangular tube or a cylindrical tube.

[0039] The ultraviolet light source 13 includes a substrate 16 and a light emitting element 17 . One or more light emitting elements 17 are disposed on the substrate 16 . Figure 1 In one example, a plurality of light emitting elements 17 are provided on a substrate 16. The substrate 16 is a plate-shaped member having a surface area on which the light emitting elements 17 are provided that is smaller than the cross-sectional area of ​​the processing space 15 that is orthogonal to the height direction of the air treatment device 1, and pattern wiring is provided on the surface. The light emitting element 17 is, for example, an ultraviolet light emitting diode (LED). Moreover, as the ultraviolet light source 13, a lamp other than LED, such as a mercury lamp, a metal halide lamp, a fluorescent ultraviolet lamp, and an excimer lamp, may also be used instead of the light emitting element 17. At this time, the ultraviolet light source 13 may also not include the substrate 16. In addition, a gap may also be formed between the ultraviolet light source 13 and the inner surface of the frame 2. At this time, in the internal cavity of the frame 2, the air passes through the gap between the ultraviolet light source 13 and the inner surface of the frame 2 and flows to the downstream side over the ultraviolet light source 13.

[0040] The ultraviolet light source 13 radiates ultraviolet light emitted from the light emitting element 17 to the processing space 15 by operating. Figure 1In one example, ultraviolet rays are emitted from the ultraviolet light source 13 toward the upstream side. In the processing space 15, the air introduced from the inlet 3 is irradiated with ultraviolet rays from the ultraviolet light source 13, and the introduced air is sterilized. Therefore, in the processing space 15, air treatment including sterilization of the introduced air is performed using ultraviolet rays from the ultraviolet light source 13. The ultraviolet light source 13, for example, radiates ultraviolet rays with a peak wavelength set at any wavelength of 230 nm to 315 nm. Among them, the ultraviolet light source 13 mainly radiates deep ultraviolet rays, and preferably radiates ultraviolet rays with a peak wavelength set at any wavelength of 250 nm to 290 nm. In one example, the ultraviolet light source 13 radiates ultraviolet rays to the processing space 15 at a peak wavelength of 280 nm by operation.

[0041] Here, the term "sterilization" means inactivating viruses and bacteria (bacteria) in the air, and the term "sterilization", "sterilization" and "disinfection" may be used instead of "sterilization". Therefore, although the term "sterilization" is used in the embodiment, the term "sterilization" may be replaced by "sterilization", "sterilization" and "disinfection".

[0042] Furthermore, it is preferred that at least the inner surface of the frame 2 is formed of a material having a high reflectivity of ultraviolet rays. At this time, as the material forming the inner surface of the frame 2, for example, aluminum alloys and stainless steel alloys can be cited. By forming the inner surface of the frame 2 of a material having a high reflectivity of ultraviolet rays, ultraviolet rays can be effectively prevented from being emitted to the outside of the frame 2.

[0043] In the air treatment device 1, the pre-filter 12 is used to prevent dust and the like from flowing into the treatment space 15 together with the introduced air. That is, dust and the like are prevented from flowing to the downstream side over the pre-filter 12. The light shielding grille 11 can block ultraviolet rays. In the air treatment device 1, the ultraviolet rays emitted from the ultraviolet light source 13 and the ultraviolet rays reflected by the inner surface of the frame 2 after being emitted from the ultraviolet light source 13 are blocked by the light shielding grille 11. By using the light shielding grille 11 to block ultraviolet rays, it is effectively prevented that the ultraviolet rays are emitted to the outside of the frame 2 through the inlet 3 and the like.

[0044] In one example, in addition to the light shielding grating 11, a light shielding grating is further arranged on the downstream side relative to the ultraviolet light source 13. In this case, the light shielding grating is arranged between the ultraviolet light source 13 and the discharge port 5 in the internal cavity of the frame 2. By arranging the light shielding grating on the downstream side relative to the ultraviolet light source 13, it is effectively prevented that the ultraviolet rays reflected by the inner surface of the frame 2 are emitted to the outside of the frame 2 through the discharge port 5 and the like.

[0045] Moreover, in one example, a photocatalyst module is arranged at a position adjacent to the pre-filter 12 on the downstream side. At this time, the ultraviolet light source 13 radiates deep ultraviolet rays, and also radiates light (such as near ultraviolet rays) that excites the photocatalyst carried by the photocatalyst module. In this example, in the processing space 15, the air introduced from the inlet 3 is also irradiated with deep ultraviolet rays from the ultraviolet light source 13, thereby sterilizing the introduced air. Moreover, in this example, near ultraviolet rays from the ultraviolet light source 13 are incident on the photocatalyst module, thereby generating active oxygen and OH radicals in the photocatalyst module. Furthermore, viruses, bacteria (bacteria), and smelly substances contained in the introduced air are decomposed by the generated active oxygen and OH radicals. Thus, sterilization and deodorization of the air are performed.

[0046] Moreover, in a certain example, the ultraviolet light source 13 may also be adjacent to the processing space 15 on the upstream side. In this case, the ultraviolet light source 13 is arranged adjacent to the downstream side of the pre-filter 12, and radiates ultraviolet light toward the downstream side. In this example, the ultraviolet light source 13 also irradiates ultraviolet light to the processing space 15. In this example, the light shielding grille is arranged adjacent to the downstream side of the processing space 15, and the processing space 15 is formed between the ultraviolet light source 13 and the light shielding grille in the height direction. Moreover, in this example, the light shielding grille effectively prevents ultraviolet light from being emitted to the outside of the frame 2 through the discharge port 5 and the like.

[0047] In this embodiment, the fan 6 is operated to generate a 1 m 3 / min or more forms an air flow from the inlet 3 to the outlet 5. That is, by the operation of the fan 6, the air 3 Air is caused to flow in the processing space 15 at a flow rate of more than 100 rpm.

[0048] Furthermore, in the air treatment device 1, as a characteristic of the ultraviolet light source 13, a radiation flow of ultraviolet rays from the ultraviolet light source 13 is specified. The radiation flow is, for example, expressed in units of mW or the like. In a certain example, the radiation flow of the ultraviolet light source 13 changes in accordance with the number of light-emitting elements provided in the ultraviolet light source 13 or the output of the light-emitting elements provided in the ultraviolet light source 13. Furthermore, as a characteristic of the ultraviolet light source 13, a radiation flow of ultraviolet rays per unit area on a cross section perpendicular to the flow direction of the air (the height direction of the air treatment device 1) is specified. As the radiation flow of ultraviolet rays per unit area, for example, the radiation flow per 1m on a cross section perpendicular to the flow direction is expressed. 2 Radiation flow, every 1m 2 The radiation flux is in mW / m 2 The ultraviolet radiation flux per unit area is a parameter corresponding to the radiation intensity of the ultraviolet rays from the ultraviolet light source 13 .

[0049] In the embodiment, the ultraviolet light source 13 is arranged at a distance of 1 m per 1 m on a cross section perpendicular to the flow direction of the air. 2 The radiation flux is 6000mW / m 2 The above method irradiates the processing space 15 with ultraviolet rays. In a preferred example, ultraviolet rays are irradiated at a rate of 1 m 2 The radiation flux is 20000mW / m 2 The ultraviolet rays are radiated from the ultraviolet light source 13 to the processing space 15 in the following manner. Therefore, in the embodiment, the appropriate range of the radiation flux per unit area on the cross section perpendicular to the flow direction of the ultraviolet rays from the ultraviolet light source 13 is set to 6000 mW / m 2 Above and 20000mW / m 2 In addition, 6000mW / m 2 Above and 20000mW / m 2 The following range is an appropriate range of the radiation flux per unit area when ultraviolet rays are radiated from the ultraviolet light source 13 at a peak wavelength of 280 nm.

[0050] Here, as a verification related to the embodiment, a first verification is performed. In the first verification, air sterilization is performed as air treatment in the same manner as in the air treatment device 1. That is, the air introduced into the treatment space 15 inside the frame 2 is irradiated with ultraviolet rays from the ultraviolet light source 13, thereby sterilizing the introduced air, and the sterilized air is discharged to the outside of the frame 2. As the air treatment device 1, a cross-sectional area perpendicular to the flow direction of the air in the treatment space 15 is uniform and is 0.0416m 2 Air handling unit.

[0051] Furthermore, when air treatment is performed, ultraviolet light is radiated from the ultraviolet light source 13 to the treatment space 15 at a peak wavelength of 280 nm. Furthermore, ultraviolet light is radiated from the ultraviolet light source 13 to the treatment space 15 at a radiation flux of about 1150 mW. Therefore, every 1 m on a cross section perpendicular to the flow direction of the air 2 The radiation flux (per unit area) is about 27700 mW / m 2 The ultraviolet rays are radiated to the processing space 15 in a manner.

[0052] In the first verification, every 1m 2 The ultraviolet radiation flux is maintained at about 27700mW / m 2In the state of , the air flow rate in the processing space 15 is changed to perform air treatment. In fact, the air flow rate in the processing space 15 is changed between each of the five test conditions A1 to A5. And, in the case of performing air treatment under each of the five test conditions A1 to A5, the arrival time until 99% sterilization of the environment (environmental space) using the air treatment device 1 is measured. In the air treatment under each of the test conditions A1 to A5, the arrival time until the amount of Staphylococcus aureus in the environment using the air treatment device 1 becomes 1% relative to the start of the air treatment is measured as the arrival time until 99% sterilization. The amount of Staphylococcus aureus in the environment using the air treatment device 1 is measured using a measuring instrument that measures the amount of bacteria.

[0053] Figure 2 The table shows the measurement results of air flow rate and time until 99% sterilization is achieved for each of the five test conditions A1 to A5 of the first verification. Figure 3 The relationship between the air flow rate in the first verification and the measurement result of the time until 99% sterilization is achieved is shown in a graph. Figure 2 and Figure 3 The time required to achieve 99% sterilization is to set the air flow rate to 1m 3 / min is taken as the reference, that is, relative to the air flow rate of 1m 3 / min test condition A3. Figure 2 and Figure 3 In the example, the value in the case of test condition A3 is set to 1, and the ratio of the time required to achieve 99% sterilization for each of test conditions A1 to A5 is shown. Figure 3 In the graph of , the horizontal axis represents the air flow rate, and the vertical axis represents the ratio of the time required to achieve 99% sterilization.

[0054] like Figure 2 and Figure 3 As shown, in the first verification, under test conditions A1, A2, A3, A4, and A5, the 3 / min、1.9m 3 / min、1m 3 / min、0.9m 3 / min、0.3m 3 / min flow rate forms air flow in the processing space 15. Moreover, the arrival time until 99% sterilization is 42min, 44min, 69min, 91min, and 254min under test conditions A1, A2, A3, A4, and A5, respectively. Therefore, the ratio of the arrival time to the arrival time under test condition A3 is 0.61, 0.64, 1, 1.32, and 3.68 under test conditions A1, A2, A3, A4, and A5, respectively. In addition, Figure 3 In FIG. 1 , data points D1 , D2 , D3 , D4 , and D5 are shown as data points corresponding to test conditions A1 , A2 , A3 , A4 , and A5 , respectively. Figure 3 In FIG. 1 , an approximate curve α of data point D1 to data point D5 is shown.

[0055] It has been confirmed from the data points D1 to D5 and the approximate curve α shown as the verification results in the first verification that 2 The ultraviolet radiation flux is about 27700mW / m 2 In the case of air flow less than 1m 3 / min, there is a tendency that the air sterilization performance (air treatment performance) is greatly improved with the increase of air flow rate. On the other hand, it is confirmed that 2 The ultraviolet radiation flux is about 27700mW / m 2 In the case of air flow rate of 1m 3 In the range of 100 rpm or more, even if the air flow rate is increased, there is a tendency that the degree of improvement in air sterilization performance is small.

[0056] Moreover, in Figure 3 The slope is specified in the approximate curve α shown. When the air flow rate is 0.3m 3 / min or more and 1.9m 3 / min or less, the slope of the approximate curve α becomes a negative value, and the absolute value of the slope of the approximate curve α decreases with the increase of the air flow rate. In the first verification, in the approximate curve α, the point where the absolute value of the slope becomes a reference value is specified as a boundary point. And, based on the specified boundary point, it is determined whether the air treatment performance is greatly improved with the increase of the air flow rate. For example, in the area on the side where the air flow rate is small and the boundary point is used as the boundary, it is judged that the sterilization performance of the air (the performance of air treatment) is greatly improved with the increase of the air flow rate. On the other hand, in the area on the side where the air flow rate is large and the boundary point is used as the boundary, it is judged that even if the air flow rate is increased, the degree of improvement in the sterilization performance of the air is small.

[0057] In one example, the reference value is set to 1 for the absolute value of the slope of the approximate curve α. In another example, the absolute value of the slope between the data point D5 and the data point D4, the absolute value of the slope between the data point D4 and the data point D3, the absolute value of the slope between the data point D3 and the data point D2, and the absolute value of the slope between the data point D3 and the data point D1 are calculated. And, the absolute value of the slope between the data point D5 and the data point D4, which is the largest among the four calculated absolute values, is used to set the aforementioned reference value for the absolute value of the slope of the approximate curve α. In this case, for example, the reference value is set to 0.787, which is equivalent to 20% of the absolute value of the slope between the data point D5 and the data point D4. More preferably, the reference value is set to 0.393, which is equivalent to 10% of the absolute value of the slope between the data point D5 and the data point D4.

[0058] In the first verification, based on the set reference value, the boundary points are specified in the approximate curve α as described above, and based on the specified boundary points, the degree of improvement in the air sterilization performance caused by the increase in air flow rate is determined as described above. 2 The ultraviolet radiation flux is about 27700mW / m 2 In the case of air flow rate of 1m 3 In the range of 100 rpm or more, it is judged that even if the air flow rate is increased, the degree of improvement in the air sterilization performance tends to be small.

[0059] In addition, in the first verification, for every 1m 2 The ultraviolet radiation flux is about 27700mW / m 2 However, in every 1m 2 The ultraviolet radiation flux is maintained at a fixed level of 27700mW / m 2 In the case of different values, as long as the value of the radiation flow is maintained at a value greater than the specified level, when the air flow rate is changed, the degree of improvement in the air sterilization performance brought about by the increase in the air flow rate also shows the same as the increase in the air flow rate per 1m 2 The ultraviolet radiation flux is 27700mW / m 2 Therefore, it has been confirmed that 2 When the ultraviolet radiation flux is maintained at a fixed value, the air flow rate is 1m 3 In the range of 100 rpm or more, even if the air flow rate is increased, the degree of improvement in air sterilization performance tends to be small.

[0060] Furthermore, as a verification related to the embodiment, a second verification different from the first verification was performed. In the second verification, the air introduced into the processing space 15 inside the frame 2 was sterilized by irradiating the air with ultraviolet light from the ultraviolet light source 13, and the sterilized air was discharged to the outside of the frame 2. Also, as in the first verification, a uniform cross-sectional area of ​​0.0416 m2 orthogonal to the flow direction of the air in the processing space 15 was used. 2 Furthermore, when air treatment is performed, ultraviolet rays are radiated from the ultraviolet light source 13 to the treatment space 15 at a peak wavelength of 280 nm.

[0061] However, in the second verification, the air flow rate in the processing space 15 was not changed, but was kept constant at about 2.3 m 3 / min. And, the air flow rate is maintained at about 2.3m 3 / min, the cross section perpendicular to the air flow direction is made 2 In fact, between the six test conditions B1 to B6, the radiation flow of ultraviolet rays radiated from the ultraviolet light source 13 to the treatment space 15 is changed so that the radiation flow of ultraviolet rays per 1m 2 The radiation flow of ultraviolet rays changes. In addition, for the case where air treatment is performed under each of the six test conditions B1 to B6, the time until the environment (environmental space) using the air treatment device 1 is 99% sterilized is measured. The time until 99% sterilization is determined and measured in the same manner as the first verification.

[0062] Figure 4 The table shows the measurement results of the ultraviolet radiation flux per unit area and the time until 99% sterilization for each of the six test conditions B1 to B6 of the second verification. Figure 5 The relationship between the radiation flux of ultraviolet rays per unit area and the measurement results of the time required to achieve 99% sterilization in the second verification is shown in a graph. Figure 4 and Figure 5 In the above table, the time until 99% sterilization is achieved is expressed as a ratio to the time achieved under test condition B1. Figure 4 and Figure 5 In the example, the value in the case of test condition B1 is set to 1, and the ratio of the time required to achieve 99% sterilization is shown for each of test conditions B1 to test condition B6. Figure 5 In the graph, the horizontal axis represents the radiation flux of ultraviolet rays per unit area, and the vertical axis represents the ratio of the time required to achieve 99% sterilization.

[0063] like Figure 4 and Figure 5 As shown, in the second verification, under test conditions B1, B2, B3, B4, B5, and B6, the ultraviolet light source 13 irradiates the processing space 15 with a radiation flux of about 1020 mW, about 770 mW, about 640 mW, about 510 mW, about 260 mW, and about 130 mW, respectively. Therefore, the radiation flux of ultraviolet light per unit area is about 24600 mW / m under test conditions B1, B2, B3, B4, B5, and B6, respectively. 2 , about 18500mW / m 2 , about 15400mW / m 2 , about 12300mW / m 2 , about 6150mW / m 2 , about 3080mW / m 2 .

[0064] Furthermore, the time until 99% sterilization was achieved was 37 min, 37 min, 35 min, 41 min, 43 min, and 56 min under test conditions B1, B2, B3, B4, B5, and B6, respectively. Therefore, the ratio of the arrival time to the arrival time under test condition B1 was 1, 1, 0.95, 1.11, 1.16, and 1.54 under test conditions B1, B2, B3, B4, B5, and B6, respectively. In addition, Figure 5 In FIG. 1 , data points E1, E2, E3, E4, E5, and E6 are shown as data points corresponding to test conditions B1, B2, B3, B4, B5, and B6, respectively. Furthermore, Figure 5 In FIG. 8 , an approximate curve β of data points E1 to E5 is shown.

[0065] Based on the data points E1 to E6 and the approximate curve β shown as the verification results in the second verification, it was confirmed that the peak wavelength of ultraviolet rays was about 280nm and the air flow rate in the processing space 15 was about 2.3m 3 / min, every 1m 2 The ultraviolet radiation flux is less than 6000mW / m 2 In the range of , there is a tendency that the sterilization performance of air (performance of air treatment) is greatly improved with the increase of the radiation flow of ultraviolet rays per unit area. On the other hand, it is confirmed that the air flow rate in the treatment space 15 is about 2.3m 3 / min, every 1m2 The ultraviolet radiation flux is 6000mW / m 2 In the above range, even if the ultraviolet radiation flux per unit area is increased, the degree of improvement in air sterilization performance tends to be small. 3 / min, every 1m 2 The ultraviolet radiation flux is greater than 20000mW / m 2 In the range of , there is a tendency that the air sterilization performance does not change or hardly changes even if the ultraviolet radiation flow per unit area is changed.

[0066] Moreover, in Figure 5 The slope is specified in the approximate curve β shown. The radiation flux of ultraviolet rays per unit area is 3080 mW / m 2 Above and 24600mW / m 2 In the following range, the slope of the approximate curve β becomes a negative value, and the absolute value of the slope of the approximate curve β decreases with the increase of the ultraviolet radiation flow per unit area. In the second verification, in the approximate curve β, the point where the absolute value of the slope becomes the reference value is specified as a boundary point. And, based on the specified boundary point, it is determined whether the air treatment performance is greatly improved with the increase of the ultraviolet radiation flow per unit area. For example, in the area on the side where the radiation flow per unit area is small and the boundary point is used as the boundary, it is determined that the sterilization performance of the air (the performance of air treatment) is greatly improved with the increase of the ultraviolet radiation flow per unit area. On the other hand, in the area on the side where the radiation flow per unit area is large and the boundary point is used as the boundary, it is determined that even if the ultraviolet radiation flow per unit area is increased, the degree of improvement in the sterilization performance of the air is small.

[0067] In one example, the absolute value of the slope between data point E6 and data point E5, the absolute value of the slope between data point E5 and data point E4, the absolute value of the slope between data point E4 and data point E3, the absolute value of the slope between data point E3 and data point E2, and the absolute value of the slope between data point E2 and data point E1 are calculated. The absolute value of the slope between data point E6 and data point E5, which is the largest among the five calculated absolute values, is used. -4 , the above-mentioned reference value is set for the absolute value of the slope of the approximate curve β. In this case, for example, the reference value is set to 2.86×0, which is equivalent to 25% of the absolute value of the slope between the data point E6 and the data point E5. -5 In this example, the reference value is preferably set to 2.29×0, which is equivalent to 20% of the absolute value of the slope between the data point E6 and the data point E5. -5It is more preferable to set the reference value to 1.14×0 which is equivalent to 10% of the absolute value of the slope between data point E6 and data point E5. -5 .

[0068] In the second verification, based on the set reference value, the boundary points are specified in the approximate curve β as described above, and based on the specified boundary points, the degree of improvement in the air sterilization performance caused by the increase in the ultraviolet radiation flow per unit area is judged as described above. 3 / min, every 1m 2 The ultraviolet radiation flux is 6000mW / m 2 In the above range, it is judged that even if the ultraviolet radiation flux per unit area is increased, the degree of improvement in air sterilization performance tends to be small. In the second verification, based on the fact that the slope between data point E2 and data point E1 is zero, the air sterilization performance is improved by 1m 2 The ultraviolet radiation flux is greater than 20000mW / m 2 Within the range of , it is judged that even if the radiation flow of ultraviolet rays per unit area is changed, the air sterilization performance tends to remain unchanged or hardly change.

[0069] In the second verification, the air flow rate in the processing space 15 was 2.3 m 3 However, the air flow rate in the processing space 15 is maintained at a constant rate of 2.3 m / min. 3 / min, if the flow rate is greater than the specified level, the flow rate per 1m 2 When the ultraviolet radiation flow changes, the degree of improvement in air sterilization performance caused by the increase in radiation flow per unit area also shows the same trend as the air flow rate of 2.3m 3 Therefore, it was confirmed that when the air flow rate in the processing space 15 is maintained constant, the air flow rate per 1m in the cross section perpendicular to the flow direction is 2 The ultraviolet radiation flux is 6000mW / m 2 In the above range, even if the ultraviolet radiation flow per unit area is increased, the degree of improvement in air sterilization performance tends to be small. In addition, it has been confirmed that when the air flow rate in the treatment space 15 is maintained constant, the air sterilization performance is improved by increasing the ultraviolet radiation flow per unit area. 2 The ultraviolet radiation flux is greater than 20000mW / m 2 In the range of , there is a tendency that the air sterilization performance does not change or hardly changes even if the ultraviolet radiation flow per unit area is changed.

[0070] In this embodiment, the fan 6 is operated to generate a 1 m 3 The air flow from the inlet 3 to the outlet 5 is formed at a flow rate of more than 1 / min. In addition, the ultraviolet light source 13 is operated to form a cross section perpendicular to the air flow direction. 2 The radiation flux is 6000mW / m 2 In the above state, ultraviolet rays are irradiated to the processing space 15. When the air treatment device 1 is used to treat air, according to the first verification, the air flow rate in the processing space 15 is set to 1 m 3 / min or more, even if the air flow rate is increased, the improvement of the air sterilization performance tends to be small. Moreover, according to the second verification, for every 1m 2 The radiation flux is 6000mW / m 2 In the above range, even if the ultraviolet radiation flux per unit area is increased, the degree of improvement in air sterilization performance tends to be small.

[0071] Therefore, by setting the air flow rate in the processing space 15 to 1 m 3 / min or more and the ultraviolet radiation flux per unit area is set to 6000mW / m 2 The above can be achieved by performing air treatment including sterilization of air with a certain degree of performance within the achievable range. 3 / min or more and the ultraviolet radiation flux per unit area is set to 6000mW / m 2 As described above, sterilization is appropriately performed in the processing space 15 using ultraviolet rays.

[0072] Furthermore, by setting the air flow rate to 1m 3 / min or more and the ultraviolet radiation flux per unit area is set to 6000mW / m 2 For example, when the ultraviolet radiation flux per unit area is suppressed to 20000 mW / m 2 At the same time, ultraviolet rays are used to appropriately sterilize. By not excessively increasing the radiation flux of ultraviolet rays per unit area, heat generation in the ultraviolet light source 13 is effectively suppressed. As a result, in the air treatment device 1, temperature rise near the ultraviolet light source 13 is effectively suppressed.

[0073] Furthermore, since the ultraviolet radiation flux per unit area does not need to be excessively increased, for example, the number of light emitting elements provided in the ultraviolet light source 13 can be reduced. Thus, the man-hours and costs of manufacturing the ultraviolet light source 13 can be reduced.

[0074] Furthermore, in one example of the embodiment, at every 1m 2 The radiation flux is 20000mW / m 2 In the following state, ultraviolet rays are radiated from the ultraviolet light source 13 to the processing space 15. According to the second verification, etc., at every 1m 2 The ultraviolet radiation flux is greater than 20000mW / m 2 In the range of , there is a tendency that the air sterilization performance does not change or hardly changes even if the ultraviolet radiation flow per unit area on the cross section perpendicular to the air flow direction is changed. Therefore, it is effectively prevented that the ultraviolet radiation flow is increased in a range that does not help improve the air treatment performance. Thus, it is effectively prevented that the heat generated in the ultraviolet light source 13 is increased excessively in a range that does not help improve the air treatment performance.

[0075] In one embodiment, the ultraviolet light source 13 radiates ultraviolet light with a peak wavelength of 280 nm to the processing space 15. When radiating ultraviolet light with a peak wavelength of 280 nm, the air flow rate is set to 1 m 3 / min or more and the ultraviolet radiation flux per unit area is set to 6000mW / m 2 As described above, air treatment including air sterilization is appropriately performed with high performance.

[0076] In one embodiment, at least the inner surface of the frame 2 is formed of a material with high ultraviolet reflectivity. This effectively prevents ultraviolet rays from being emitted to the outside of the frame 2, and sterilizes the processing space 15 more efficiently using ultraviolet rays.

[0077] In addition, 6000mW / m 2 Above and 20000mW / m 2 The following range is an appropriate range of the radiation flow per unit area when ultraviolet rays are radiated from the ultraviolet light source 13 at a peak wavelength of 280 nm. In the embodiment, the radiation flow of ultraviolet rays per unit area on a cross section perpendicular to the flow direction is adjusted and corrected in accordance with the peak wavelength of ultraviolet rays. At this time, the appropriate range of the radiation flow of ultraviolet rays per unit area is corrected based on the relationship between the peak wavelength of ultraviolet rays and the inactivation sensitivity of bacteria (deoxyribonucleic acid (DNA) of bacteria, etc.).

[0078] Figure 6 and Figure 7 This figure shows an example of the relationship between the peak wavelength of ultraviolet rays and the inactivation sensitivity. Figure 6 In the table, the relationship between the peak wavelength of ultraviolet light and the inactivation sensitivity is shown. Figure 7, the relationship between the peak wavelength of ultraviolet rays and the inactivation sensitivity is shown in a graph in which the horizontal axis is the peak wavelength and the vertical axis is the inactivation sensitivity. Figure 6 and Figure 7 In the figure, the peak wavelength is expressed in nm, and the inactivation sensitivity is expressed as a ratio to the inactivation sensitivity when the peak wavelength is 263 nm. That is, the inactivation sensitivity is expressed as 1 when the peak wavelength is 263 nm. Figure 6 In the figure, the inactivation sensitivity value relative to the ultraviolet peak wavelength is shown every 5 nm within the range of 230 nm to 315 nm. Figure 7 In Figure 6 The data points corresponding to the peak wavelength and the curve γ connecting the data points are shown.

[0079] exist Figure 6 and Figure 7 In one example, when the peak wavelength of ultraviolet light is 263 nm, the inactivation sensitivity reaches the highest peak. The peak wavelength is set as a variable λ and the inactivation sensitivity is set as a variable ε. Figure 2 and Figure 3 In one example, the relationship of formula (1) holds true when the peak wavelength is between 230 nm and 263 nm (230 nm≦λ≦263 nm). Furthermore, the relationship of formula (2) holds true when the peak wavelength is between 263 nm and 315 nm (263 nm≦λ≦315 nm). Therefore, using the relationship of formula (1) and formula (2), the inactivation sensitivity ε can be calculated from the peak wavelength λ.

[0080] [Number 1]

[0081] ε=-3×10 -5 λ 3 +0.0249λ 2 -6.0825λ+493.37(230≤λ≤263) (1)

[0082] ε=1×10 -5 λ 3 -0.0092λ 2 +2.6049λ+243.48(263≤λ≤315) (2)

[0083] Here, it is assumed that the appropriate range for the ultraviolet radiation flux per unit area when the peak wavelength λ is 280nm is corrected to the appropriate range when the peak wavelength λ is λa. At this time, the value εa of the inactivation sensitivity ε when the peak wavelength λ is λa is calculated using formula (1) or formula (2). In addition, the ratio of the value εa to the inactivation sensitivity ε when the peak wavelength λ is 280nm, that is, 0.7, is calculated, that is, the inactivation sensitivity ratio ηa. That is, the inactivation sensitivity ratio ηa is calculated using formula (3).

[0084] Furthermore, for the radiation flow of ultraviolet rays per unit area on a cross section perpendicular to the air flow direction, the lower limit Iamin and upper limit Iamax of the appropriate range when the peak wavelength λ of ultraviolet rays is λa are specified. The lower limit Iamin is the lower limit of the appropriate range when the peak wavelength λ is 280nm, that is, 6000mW / m 2 The upper limit value Iamax is the upper limit value of the appropriate range when the peak wavelength λ is 280 nm, that is, 20000 mW / m 2 and the calculated inactivation sensitivity ratio ηa, and is calculated as in equation (5). Thus, for the radiation flux of ultraviolet rays per unit area on a cross section perpendicular to the air flow direction, the appropriate range when the peak wavelength λ is the value λa is calculated.

[0085] [Number 2]

[0086]

[0087]

[0088]

[0089] For example, when calculating the appropriate range of the ultraviolet radiation flux per unit area when the peak wavelength λ is 265nm, 0.99 is calculated as the inactivation sensitivity ε, and the value of the inactivation sensitivity ratio ηa is calculated as 1.41 by formula (3). And, by formula (4) and formula (5), the ultraviolet radiation flux per unit area is calculated as 4255mW / m 2 As the lower limit value Iamin of the appropriate range, 14184 mW / m 2 As a result, the appropriate range for the radiation flux per unit area when the peak wavelength is 280nm is corrected to the appropriate range when the peak wavelength is 265nm, that is, 4255mW / m 2 Above 14184mW / m 2 The following range.

[0090] When the peak wavelength λ of the ultraviolet light from the ultraviolet light source 13 is λa, the air flow rate in the processing space 15 is set to 1 m 3 / min or more and the radiation flux of ultraviolet rays per unit area is set to be above the aforementioned lower limit Iamin or more. Furthermore, when the peak wavelength λ of ultraviolet rays from the ultraviolet light source 13 is λa, in a preferred example, the radiation flux of ultraviolet rays per unit area is set to be below the aforementioned upper limit Iamax. By performing air treatment including sterilization of air under such conditions, the same action and effect as the aforementioned embodiment in which the peak wavelength λ of ultraviolet rays from the ultraviolet light source 13 is 280nm is achieved.

[0091] According to at least one of these embodiments, the fan is located in the process space at 1 m 3 The air flow from the inlet to the outlet is formed by a flow rate of more than / min. The ultraviolet light source is placed on a cross section perpendicular to the air flow direction for every 1m 2 The radiation flux is 6000mW / m 2 In the above state, ultraviolet rays are radiated to the processing space. Thus, it is possible to provide an air treatment device that appropriately sterilizes the processing space using ultraviolet rays while suppressing heat generation in the ultraviolet light source.

[0092] Several embodiments of the present invention have been described, but these embodiments are provided as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. These embodiments or their variations are included in the scope or spirit of the invention, and are included in the invention described in the claims and their equivalents.

Claims

1. An air treatment device, comprising: A frame body having an inlet for introducing air into the interior and an outlet for discharging the air to the outside, and a processing space is formed in the path of the air from the inlet to the outlet, wherein the cross-sectional area perpendicular to the flow direction of the air in the processing space is uniform; The fan, by operation, moves a 1m 3 / min or more to form a flow of the air from the inlet toward the outlet; as well as The ultraviolet light source is operated so that every 1m on a cross section perpendicular to the flow direction of the air 2 The radiation flux is 6000mW / m 2 In the above state, ultraviolet rays are irradiated to the processing space.

2. The air treatment device according to claim 1, wherein the ultraviolet light source is operated to 2 The radiation flux is 20000mW / m 2 Ultraviolet rays are irradiated to the processing space in the following state. 3 . The air treatment device according to claim 1 , wherein the ultraviolet light source radiates the ultraviolet light to the treatment space at a peak wavelength of 280 nm by operation.

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