Air treating device

Abstract

To provide an air treating device that efficiently performs sterilization with ultraviolet ray in a treatment space.SOLUTION: According to an embodiment, an air treating device includes a housing, a fan and an ultraviolet light source. In the housing, a treatment space is formed in the air path from an inlet to a discharge port, and in the treatment space, a cross-sectional area perpendicular to the air flow direction is uniform. The fan forms a flow of air from the inlet to the outlet at a flow rate of 1 m3 / min or more in the treatment space. The ultraviolet light source emits ultraviolet rays into the treatment space in a state where a radiant flux per 1 m2 in a cross-section perpendicular to the direction of air flow is 6000 mW / m2 or more.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE Embodiments of the present invention relate to an air treatment device. [Background technology]

[0002] There is known an air treatment device that sterilizes air by using ultraviolet light. In this type of air treatment device, a treatment space is formed inside a housing, and outside air is introduced into the housing through an inlet. Then, the introduced air is irradiated with ultraviolet light from an ultraviolet light source in the treatment space, for example, to sterilize the introduced air. Then, the air that has been sterilized by the ultraviolet light is discharged to the outside of the housing through an outlet.

[0003] In the air treatment device as described above, it is required to treat the air efficiently by, for example, minimizing the amount of ultraviolet radiation or heat generated from the ultraviolet light source as much as possible while maintaining sterilization performance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-51268 A Summary of the Invention [Problem to be solved by the invention]

[0005] The problem to be solved by the present invention is to provide an air treatment device that efficiently sterilizes a treatment space by using ultraviolet light. [Means for solving the problem]

[0006] According to an embodiment, the air treatment device comprises a housing, a fan, and an ultraviolet light source. The housing is formed with an inlet for introducing air into the inside and an outlet for discharging the air to the outside, 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 air flow direction is uniform. When the fan is operated, the treatment space is heated to a temperature of 1 m. 3 An air flow is formed from the inlet to the outlet at a flow rate of at least 1 / min. The ultraviolet light source is operated to form an air flow of 1 m 2 The radiant flux per unit is 6000mW / m 2 In this state, ultraviolet rays are radiated into the processing space. Effect of the Invention

[0007] According to the present invention, it is possible to provide an air treatment device that efficiently performs sterilization in a treatment space using ultraviolet light. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of an air treatment device according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing, in a table, the measurement results of the air flow rate and the time required to achieve 99% sterilization for each of the five test conditions in the first verification. [Diagram 3] FIG. 3 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. [Figure 4] FIG. 4 is a schematic diagram showing, in a table, the measurement results of the ultraviolet radiant flux per unit area and the time required to achieve 99% sterilization for each of the six test conditions in the second verification. [Diagram 5] FIG. 5 is a schematic graph showing the relationship between the ultraviolet radiant flux per unit area and the measurement results of the time required for 99% sterilization in the second verification. [Figure 6] FIG. 6 is a schematic diagram showing, in the form of a table, an example of the relationship between the peak wavelength of ultraviolet light and the inactivation sensitivity. [Figure 7] FIG. 7 is a schematic diagram showing in a graph the relationship between the peak wavelength of ultraviolet light and the inactivation sensitivity of the example of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The air treatment device (1) of the embodiment includes a housing (2), a fan (6), and an ultraviolet light source (13). The housing (2) is formed with an inlet (3) for introducing air into the inside and an outlet (5) for discharging the air to the outside, and a treatment space (15) is formed in the air path from the inlet (3) to the outlet (5). In the treatment space (15), the cross-sectional area perpendicular to the air flow direction is uniform. The fan (6) is operated to increase the air flow rate by 1 m in the treatment space (15). 3 The ultraviolet light source (13) forms an air flow from the inlet (3) to the outlet (5) at a flow rate of at least 1 m3 / min. 2 The radiant flux per unit is 6000mW / m 2 In the above-mentioned state, ultraviolet rays are radiated into the treatment space (15). As a result, sterilization is appropriately performed in the treatment space (15) using ultraviolet rays, and heat generation in the ultraviolet light source (13) can be effectively suppressed, enabling efficient air treatment.

[0010] In the embodiment of the air treatment device (1), the ultraviolet light source (13) is operated to 2 The radiant flux per unit is 20,000 mW / m 2 Ultraviolet rays are radiated into the treatment space (15) under the following conditions: An excessive increase in the amount of heat generated by the ultraviolet light source (13) is effectively prevented, so long as it does not contribute to improving the performance of the air treatment, thereby enabling efficient air treatment.

[0011] In the embodiment of the air treatment device (1), the ultraviolet light source (13) is operated to radiate ultraviolet light with a peak wavelength of 280 nm into the treatment space (15). This reduces the air flow rate by 1 m 3 / min or more, and the ultraviolet radiation flux per unit area in the cross section perpendicular to the flow direction is 6000mW / m 2 By doing the above, air treatment including air sterilization can be performed appropriately with high performance.

[0012] Hereinafter, embodiments will be described with reference to the drawings.

[0013] Fig. 1 shows an example of an air treatment device 1 according to an embodiment. In the example of the air treatment device 1 in Fig. 1, a height direction (direction indicated by arrow X), a width direction (direction indicated by arrow Y) intersecting (perpendicular or approximately perpendicular) with the height direction, and a depth direction (direction perpendicular or approximately perpendicular to the paper surface of Fig. 1) intersecting (perpendicular or approximately perpendicular) with both the height direction and the width direction are defined. Fig. 1 shows a cross section perpendicular or approximately perpendicular to the depth direction.

[0014] As shown in Fig. 1, the air treatment device 1 includes a housing 2, and an internal cavity is formed inside the housing 2. Therefore, in the air treatment device 1, the housing 2 forms an exterior. The housing 2 is formed with an inlet 3 and an outlet 5. The internal cavity of the housing 2 opens to the outside of the housing 2 at the inlet 3 and the outlet 5, respectively. In the example of Fig. 1, the housing 2 has the inlet 3 formed in one end face in the height direction. And the housing 2 has the outlet 5 formed in the end face opposite the inlet 3 in the height direction.

[0015] A fan 6 is disposed in the internal cavity of the housing 2. In the example of FIG. 1, the fan 6 is disposed facing the exhaust port 5 from the inside, and an exhaust fan is used as the fan 6. When the air processing device 1 is used, the fan 6 is operated. By operating the fan 6, external air is introduced from the inlet port 3 into the internal cavity inside the housing 2. Then, an air flow is formed inside the housing 2 from the inlet port 3 toward the exhaust port 5. Then, air is exhausted from the internal cavity to the outside of the housing 2 through the exhaust port 5.

[0016] When an air flow is formed as described above, the direction from the inlet 3 to the outlet 5 in the internal cavity of the housing 2 is the air flow direction (direction indicated by arrow F). In the example of FIG. 1, the air flow direction in the internal cavity is along the height direction of the air processing device 1. In addition, in the internal cavity of the housing 2, the side of the air flow direction, i.e., the side toward the outlet 5, is defined as the downstream side. In addition, in the internal cavity of the housing 2, the opposite direction to the air flow direction, i.e., the side toward the inlet 3, is defined as the upstream side. Hereinafter, the expressions upstream (side) and downstream (side) refer to the upstream (side) and downstream (side) with respect to the air flow.

[0017] In one example of FIG. 1, in the internal cavity of the housing 2, the light shielding grill 11, the pre-filter 12, the ultraviolet light source 13, and the fan 6 are arranged in this order from the upstream side. In one example, in the internal cavity, the fan 6 is arranged on the upstream side of the light shielding grill 11. In this case, the fan 6 is arranged facing the inlet 3 from the inside, and an intake fan is used as the fan 6. Even in a configuration in which an intake fan is used as the fan 6, an air flow from the inlet 3 to the exhaust port 5 is formed in the internal cavity of the housing 2 by operating the fan 6. Note that the air flow direction F shown in FIG. 1 is an example, and the air flow direction may be the opposite direction to F. In this case, the opening of the inlet 3 in FIG. 1 functions as the exhaust port, and the opening of the exhaust port 5 in FIG. 1 functions as the inlet.

[0018] 1, a treatment space 15 is formed in the internal cavity of the housing 2 between the ultraviolet light source 13 and the prefilter 12 in the height direction. The treatment space 15 is formed on the air path from the inlet 3 to the outlet 5. When the air treatment device 1 is in use, air treatment is performed on the air introduced into the housing 2 using ultraviolet light in the treatment space 15. In the example of FIG. 1, the ultraviolet light source 13 is adjacent to the treatment space 15 from the downstream side, and the prefilter 12 is adjacent to the treatment space 15 from the upstream side.

[0019] In one example, the dimension of the treatment space 15 along the height direction, i.e., the distance between the ultraviolet light source 13 and the pre-filter 12 in the height direction, is 50 mm or more and 1000 mm or less. In the air treatment device 1, a virtual center plane that is the center position of the housing 2 in the height direction is located in the treatment space 15, and is located between the ultraviolet light source 13 and the pre-filter 12. In other words, the treatment space 15 is arranged so as to overlap with the center of the height direction of the air treatment device 1. In addition, in the treatment space 15, the cross-sectional area perpendicular to the air flow direction is uniform. In other words, in the treatment space 15, the cross-sectional area perpendicular to the height direction of the air treatment device 1 is constant or approximately constant from the upstream end to the downstream end. The treatment space 15 may be, for example, a rectangular parallelepiped cylinder or a cylindrical cylinder.

[0020] The ultraviolet light source 13 includes a substrate 16 and a light-emitting element 17, and one or more light-emitting elements 17 are installed on the substrate 16. In one example of FIG. 1, a plurality of light-emitting elements 17 are installed on the substrate 16. The substrate 16 is a plate-shaped member in which the area of ​​the surface on which the light-emitting element 17 is installed is smaller than the cross-sectional area perpendicular to the height direction of the air treatment device 1 of the treatment space 15, and pattern wiring is provided on the surface. The light-emitting element 17 is, for example, an ultraviolet LED. In addition, as the ultraviolet light source 13, lamps other than LEDs, such as mercury lamps, metal halide lamps, fluorescent ultraviolet lamps, and excimer lamps, may be used instead of the light-emitting element 17. In this case, the ultraviolet light source 13 does not need to include the substrate 16. A gap may be formed between the ultraviolet light source 13 and the inner surface of the housing 2. In this case, in the internal cavity of the housing 2, air flows downstream beyond the ultraviolet light source 13 through the gap between the ultraviolet light source 13 and the inner surface of the housing 2.

[0021] When the ultraviolet light source 13 is operated, it radiates ultraviolet light emitted by the light emitting element 17 into the processing space 15. In one example of FIG. 1, ultraviolet light is 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 light from the ultraviolet light source 13, and the like, to sterilize the introduced air. Therefore, in the processing space 15, air treatment including sterilization of the introduced air is performed using ultraviolet light from the ultraviolet light source 13. The ultraviolet light source 13 radiates ultraviolet light having a peak wavelength of, for example, any one of 230 nm or more and 315 nm or less. However, it is preferable that the ultraviolet light source 13 mainly radiates deep ultraviolet light and radiates ultraviolet light having a peak wavelength of any one of 250 nm or more and 290 nm or less. In one example, when the ultraviolet light source 13 is operated, it radiates ultraviolet light into the processing space 15 with a peak wavelength of 280 nm.

[0022] Here, "sterilization" means inactivating viruses and bacteria (bacteria) present in the air, and terms such as "disinfection", "sterilization" and "sterilization" can be used instead of "sterilization". Therefore, although the term "sterilization" is used in the embodiment, the term "sterilization" can be replaced with "sterilization", "sterilization" and "sterilization".

[0023] In addition, it is preferable that at least the inner surface of the housing 2 is made of a material having a high ultraviolet reflectance. In this case, examples of materials for forming the inner surface of the housing 2 include aluminum alloys and stainless steel alloys. By forming the inner surface of the housing 2 from a material having a high ultraviolet reflectance, ultraviolet rays are effectively prevented from being emitted to the outside of the housing 2.

[0024] In the air treatment device 1, the prefilter 12 prevents dust and the like from flowing into the treatment space 15 together with the introduced air. In other words, the dust and the like is prevented from flowing downstream beyond the prefilter 12. The shading grill 11 is capable of blocking ultraviolet rays. In the air treatment device 1, the shading grill 11 blocks ultraviolet rays emitted from the ultraviolet light source 13 and ultraviolet rays reflected on the inner surface of the housing 2 after being emitted from the ultraviolet light source 13. By blocking the ultraviolet rays with the shading grill 11, the ultraviolet rays are effectively prevented from being emitted to the outside of the housing 2 through the inlet 3 or the like.

[0025] In one example, in addition to the light-shielding grille 11, a light-shielding grille is disposed downstream of the ultraviolet light source 13. In this case, the light-shielding grille is disposed between the ultraviolet light source 13 and the exhaust port 5 in the internal cavity of the housing 2. By disposing the light-shielding grille downstream of the ultraviolet light source 13, ultraviolet rays reflected on the inner surface of the housing 2 are effectively prevented from being emitted to the outside of the housing 2 through the exhaust port 5 or the like.

[0026] In one example, a photocatalyst module is disposed adjacent to the prefilter 12 on the downstream side. In this case, the ultraviolet light source 13 emits deep ultraviolet light and also emits light (for example, near ultraviolet light) that excites the photocatalyst supported on the photocatalyst module. In this example, air introduced from the inlet 3 in the treatment space 15 is irradiated with deep ultraviolet light from the ultraviolet light source 13 to sterilize the introduced air. In this example, active oxygen and OH radicals are generated in the photocatalyst module by the near ultraviolet light from the ultraviolet light source 13 being incident on the photocatalyst module. Then, the generated active oxygen and OH radicals decompose viruses, bacteria (bacteria), odorous substances, and the like contained in the introduced air. This allows sterilization and deodorization of the air to be performed.

[0027] In addition, in one example, the ultraviolet light source 13 may be adjacent to the upstream side of the processing space 15. In this case, the ultraviolet light source 13 is disposed adjacent to the downstream side of the prefilter 12, and radiates ultraviolet light toward the downstream side. In this example, the ultraviolet light source 13 also irradiates ultraviolet light into the processing space 15. In this example, a light-shielding grill is disposed 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 filter in the height direction. In this example, the light-shielding grill effectively prevents the ultraviolet light from being emitted to the outside of the housing 2 through the exhaust port 5 or the like.

[0028] In this embodiment, the fan 6 is operated to increase the air flow rate by 1 m 3 An air flow is formed from the inlet 3 to the outlet 5 at a flow rate of 1 m3 / min or more. 3 Air flows in the treatment space 15 at a flow rate of 1 / min or more.

[0029] Furthermore, in the air treatment device 1, the radiant flux of ultraviolet light from the ultraviolet light source 13 is defined as a characteristic of the ultraviolet light source 13. The radiant flux is expressed in units of, for example, mW. In one example, the radiant flux of the ultraviolet light source 13 varies in response to the number of light-emitting elements provided in the ultraviolet light source 13 and the output of the light-emitting elements provided in the ultraviolet light source 13. Furthermore, the radiant flux of ultraviolet light per unit area in a cross section perpendicular to the air flow direction (height direction of the air treatment device 1) is defined as a characteristic of the ultraviolet light source 13. The radiant flux of ultraviolet light per unit area is, for example, the radiant flux per unit area per 1 m in a cross section perpendicular to the air flow direction. 2 The radiant flux per m is shown. 2 The radiant flux per unit is mW / m 2 The ultraviolet radiant flux per unit area is a parameter corresponding to the radiation intensity of the ultraviolet light from the ultraviolet light source 13.

[0030] In the embodiment, the ultraviolet light source 13 is 1 m 2 The radiant flux per unit is 6000mW / m 2 In a preferred example, the ultraviolet rays are irradiated into the processing space 15 so that the distance between the ultraviolet rays and the processing space 15 is 1 m or more.2 The radiant flux per unit is 20,000 mW / m 2 The ultraviolet light is emitted from the ultraviolet light source 13 into the processing space 15 so that the ultraviolet light is in the range of 6000 mW / m2 or less. Therefore, in the embodiment, the appropriate range of the radiant flux per unit area in a cross section perpendicular to the flow direction for the ultraviolet light from the ultraviolet light source 13 is 6000 mW / m2 or less. 2 or more and 20,000mW / m 2 The following ranges are specified: 6000mW / m 2 or more and 20,000mW / m 2 The following ranges are suitable ranges for radiant flux per unit area when ultraviolet light is emitted from the ultraviolet light source 13 at a peak wavelength of 280 nm.

[0031] Here, a first verification was carried out as a verification related to the embodiment. In the first verification, air sterilization was carried out as air treatment in the same manner as in the air treatment device 1. That is, air introduced into the treatment space 15 inside the housing 2 was irradiated with ultraviolet light from the ultraviolet light source 13 to sterilize the introduced air, and the sterilized air was discharged to the outside of the housing 2. The air treatment device 1 was a device having a cross-sectional area of ​​0.0416 m2 in the treatment space 15 perpendicular to the air flow direction. 2 An air treatment device was used to achieve uniformity.

[0032] When performing air treatment, ultraviolet light was radiated from the ultraviolet light source 13 to the treatment space 15 with a peak wavelength of 280 nm. The ultraviolet light was radiated from the ultraviolet light source 13 to the treatment space 15 with a radiant flux of about 1150 mW. 2 The radiant flux per unit area is approximately 27,700 mW / m 2 Ultraviolet rays were irradiated into the treatment space 15 so as to obtain the following:

[0033] In the first test, 1m 2 The UV radiation flux per unit is about 27,700 mW / m 2The air was treated by changing the air flow rate in the treatment space 15 while keeping the temperature at 100° C. The air flow rate in the treatment space 15 was actually changed between five test conditions A1 to A5. Then, the time required for the environment (environmental space) in which the air treatment device 1 was used to be 99% sterilized was measured for each of the five test conditions A1 to A5. In the air treatment under each of the test conditions A1 to A5, the time required for the amount of Staphylococcus aureus in the environment in which the air treatment device 1 was used to be 1% of the amount at the start of the air treatment was measured as the time required for 99% sterilization. The amount of Staphylococcus aureus in the environment in which the air treatment device 1 was used was measured using a measuring device that measures the amount of bacteria.

[0034] Fig. 2 shows in a table the measurement results of the air flow rate and the time to reach 99% sterilization for each of the five test conditions A1 to A5 in the first verification. Fig. 3 shows in a graph the relationship between the air flow rate and the measurement results of the time to reach 99% sterilization in the first verification. In Figs. 2 and 3, the time to reach 99% sterilization increases when the air flow rate is 1 m 3 / min, that is, when the air flow rate is 1m 3 The time to reach 99% sterilization is shown as a ratio to the time to reach 99% sterilization under test condition A3, where the value is 1 / min. That is, in Figures 2 and 3, the value for test condition A3 is set to 1, and the ratio of the time to reach 99% sterilization is shown for each of test conditions A1 to A5. In the graph of Figure 3, the horizontal axis indicates the air flow rate, and the vertical axis indicates the ratio of the time to reach 99% sterilization.

[0035] As shown in Figures 2 and 3, in the first verification, the test conditions A1, A2, A3, A4, and A5 were 1.9 m 3 / min,1.9m 3 / min,1m 3 / min,0.9m 3 / min,0.3m 3An air flow was formed in the treatment space 15 at a flow rate of 1 / min. The time to reach 99% sterilization was 42 min, 44 min, 69 min, 91 min, and 254 min under test conditions A1, A2, A3, A4, and A5, respectively. Therefore, the ratio of the time to reach 99% sterilization was 0.61, 0.64, 1, 1.32, and 3.68 under test conditions A1, A2, A3, A4, and A5, respectively. In FIG. 3, data points D1, D2, D3, D4, and D5 are shown as data points corresponding to test conditions A1, A2, A3, A4, and A5, respectively. In FIG. 3, an approximation curve α of the data points D1 to D5 is also shown.

[0036] From the data points D1 to D5 and the approximation curve α shown as the verification results in the first verification, 2 The UV radiation flux per unit is about 27,700 mW / m 2 If the air flow rate is 1m 3 It was confirmed that in the range of less than 1 m / min, the air sterilization performance (air treatment performance) tends to improve significantly with an increase in air flow rate. 2 The UV radiation flux per unit is about 27,700 mW / m 2 If the air flow rate is 1m 3 It was confirmed that within the range of 100 / min or more, even if the air flow rate is increased, the degree of improvement in the sterilization performance of the air tends to be small.

[0037] In addition, the slope of the approximation curve α shown in FIG. 3 is specified. 3 / min or more and 1.9m 3In the range of 1 / min or less, the slope of the approximation curve α becomes a negative value, and the absolute value of the slope of the approximation curve α decreases with an increase in the air flow rate. In the first verification, the point on the approximation curve α where the absolute value of the slope becomes a reference value is defined as the boundary point. Then, based on the defined boundary point, it was determined whether the air treatment performance is significantly improved with an increase in the air flow rate. For example, it was determined that in the region on the side of the boundary point where the air flow rate is small, the air sterilization performance (air treatment performance) is significantly improved with an increase in the air flow rate. On the other hand, in the region on the side of the boundary point where the air flow rate is large, it was determined that the degree of improvement in the air sterilization performance is small even if the air flow rate is increased.

[0038] In one example, the reference value for the absolute value of the slope of the approximation curve α was set to 1. In another example, the absolute value of the slope between data points D5 and D4, the absolute value of the slope between data points D4 and D3, the absolute value of the slope between data points D3 and D2, and the absolute value of the slope between data points D3 and D1 were calculated. Then, the absolute value of the slope between data points D5 and D4, which is the largest of the four calculated absolute values, 3.93, was used to set the above-mentioned reference value for the absolute value of the slope of the approximation curve α. In this case, for example, the reference value is set to 0.787, which corresponds to 20% of the absolute value of the slope between data points D5 and D4, and more preferably, the reference value is set to 0.393, which corresponds to 10% of the absolute value of the slope between data points D5 and D4.

[0039] In the first verification, the boundary point on the approximation curve α was defined as described above based on the set reference value, and the degree of improvement in the sterilization performance of the air with an increase in the air flow rate was determined as described above based on the defined boundary point. 2 The UV radiation flux per unit is about 27,700 mW / m 2 If the air flow rate is 1m 3 / min or more, even if the air flow rate is increased, the degree of improvement in the sterilization performance of the air tends to be small.

[0040] In the first verification, 2 The UV radiation flux per unit is about 27,700 mW / m2 However, the case of 1m 2 The UV radiation flux per unit is 27,700 mW / m 2 Even if the radiant flux is kept constant at a value different from that of the airflow rate, if the maintained radiant flux value is greater than a specified level, the degree of improvement in the sterilization performance of the air with an increase in the airflow rate is about 1 m. 2 The UV radiation flux per unit is 27,700 mW / m 2 The trend was similar to that of the 1m 2 If the UV radiation flux per unit area is kept constant, the air flow rate is 1 m 3 It was confirmed that within the range of 100 / min or more, even if the air flow rate is increased, the degree of improvement in the sterilization performance of the air tends to be small.

[0041] As a verification related to the embodiment, a second verification separate from the first verification was performed. In the second verification, the air introduced into the processing space 15 inside the housing 2 was irradiated with ultraviolet light from the ultraviolet light source 13 to sterilize the introduced air, and the sterilized air was discharged to the outside of the housing 2. As in the first verification, in the processing space 15, a cross-sectional area perpendicular to the air flow direction was 0.0416 m 2 In addition, when performing the air treatment, ultraviolet light was irradiated from the ultraviolet light source 13 into the treatment space 15 with a peak wavelength of 280 nm.

[0042] However, in the second verification, the air flow rate in the processing space 15 was not changed, and the flow rate was set to about 2.3 m 3 The air flow rate was kept constant at 2.3 m / min. 3 / min, 1m at a cross section perpendicular to the air flow direction 2 Air treatment was carried out by changing the radiant flux of ultraviolet light per unit area. In fact, the radiant flux of ultraviolet light radiated from the ultraviolet light source 13 to the treatment space 15 was changed between each of the six test conditions B1 to B6, and the measurement was performed at a distance of 1 m 2The radiant flux of ultraviolet light per unit area was changed. Then, for each of the six test conditions B1 to B6, the time required for the environment (environmental space) in which the air treatment device 1 is used to be 99% sterilized was measured. The time required for 99% sterilization was specified and measured in the same manner as in the first verification.

[0043] FIG. 4 shows, in a table, the measurement results of the ultraviolet ray irradiance per unit area and the time required to reach 99% sterilization for each of the six test conditions B1 to B6 in the second verification. FIG. 5 shows, in a graph, the relationship between the ultraviolet ray irradiance per unit area and the time required to reach 99% sterilization in the second verification. In FIG. 4 and FIG. 5, the time required to reach 99% sterilization is shown as a ratio to the time required to reach 99% sterilization in the case of test condition B1. That is, in FIG. 4 and FIG. 5, the value in the case of test condition B1 is set to 1, and the ratio of the time required to reach 99% sterilization is shown for each of test conditions B1 to B6. In the graph of FIG. 5, the horizontal axis shows the ultraviolet ray irradiance per unit area, and the vertical axis shows the ratio of the time required to reach 99% sterilization.

[0044] 4 and 5, in the second verification, ultraviolet light was irradiated from the ultraviolet light source 13 to the processing space 15 with radiant fluxes of about 1020 mW, about 770 mW, about 640 mW, about 510 mW, about 260 mW, and about 130 mW under test conditions B1, B2, B3, B4, B5, and B6, respectively. Therefore, the irradiated flux of ultraviolet light per unit area was 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 It became.

[0045] The time to reach 99% sterilization 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 time to reach 99% sterilization was 1, 1, 0.95, 1.11, 1.16, and 1.54 under test conditions B1, B2, B3, B4, B5, and B6, respectively. In FIG. 5, 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. In FIG. 5, the approximation curve β of data points E1 to E5 is also shown.

[0046] From the data points E1 to E6 and the approximation curve β shown as the verification results in the second verification, it is found that the peak wavelength of the ultraviolet light is about 280 nm and the air flow rate in the processing space 15 is about 2.3 m 3 / min, 1m 2 The UV radiation flux per unit is 6000mW / m 2 It was confirmed that in a smaller range, the air sterilization performance (air treatment performance) tends to improve significantly with an increase in the ultraviolet radiation flux per unit area. On the other hand, when the air flow rate in the treatment space 15 is about 2.3 m 3 / min, 1m 2 The UV radiation flux per unit is 6000mW / m 2 It was confirmed that, within the above range, even if the ultraviolet radiation flux per unit area is increased, the degree of improvement in the sterilization performance of the air tends to be small. In addition, when the air flow rate in the treatment space 15 is about 2.3 m 3 / min, 1m 2 The UV radiation flux per unit is 20,000 mW / m 2 It was confirmed that over a larger range, even if the ultraviolet radiant flux per unit area is changed, the air sterilization performance tends to not change, or to change very little.

[0047] The slope of the approximation curve β shown in FIG. 5 is specified. The ultraviolet ray radiant flux per unit area is 3080 mW / m 2 or more and 24600mW / m 2In the following range, the slope of the approximation curve β becomes a negative value, and the absolute value of the slope of the approximation curve β decreases with an increase in the ultraviolet radiation flux per unit area. In the second verification, the point where the absolute value of the slope of the approximation curve β becomes a reference value is defined as a boundary point. Then, based on the defined boundary point, it was determined whether the air treatment performance is significantly improved with an increase in the ultraviolet radiation flux per unit area. For example, it was determined that in the region on the side of the boundary point where the radiation flux per unit area is small, the air sterilization performance (air treatment performance) is significantly improved with an increase in the ultraviolet radiation flux per unit area. On the other hand, in the region on the side of the boundary point where the radiation flux per unit area is large, it was determined that the degree of improvement in the air sterilization performance is small even if the ultraviolet radiation flux per unit area is increased.

[0048] In one example, the absolute value of the slope between data points E6 and E5, the absolute value of the slope between data points E5 and E4, the absolute value of the slope between data points E4 and E3, the absolute value of the slope between data points E3 and E2, and the absolute value of the slope between data points E2 and E1 were calculated. Then, the absolute value of the slope between data points E6 and E5, which is the largest of the five calculated absolute values, was 1.14×10 -4 The above-mentioned reference value was set for the absolute value of the slope of the approximation curve β using the above formula. In this case, for example, 2.86×0 -5 In this example, the reference value is set to 2.29×0, which corresponds to 20% of the absolute value of the slope between the data points E6 and E5. -5 It is preferable to set the reference value to 1.14×0, which corresponds to 10% of the absolute value of the slope between the data points E6 and E5. -5 It is more preferable that the reference value be set to

[0049] In the second verification, the boundary point was defined as described above on the approximation curve β based on the set reference value, and the degree of improvement in the sterilization performance of the air with an increase in the radiant flux of ultraviolet light per unit area was determined as described above based on the defined boundary point. 3 / min, 1m 2The UV radiation flux per unit is 6000mW / m 2 In the above range, it was determined that the degree of improvement in the sterilization performance of the air tends to be small even if the ultraviolet radiation flux per unit area is increased. In addition, in the second verification, based on the fact that the slope between data points E2 and E1 is zero, 2 The UV radiation flux per unit is 20,000 mW / m 2 It was determined that, over a larger range, even if the ultraviolet radiant flux per unit area is changed, the air sterilization performance tends not to change, or to change very little.

[0050] In the second verification, the flow rate of air in the processing space 15 was 2.3 m 3 / min. However, the air flow rate in the treatment space 15 is 2.3 m 3 Even if the flow rate is kept constant at a value other than 1 / min, if the flow rate is greater than the specified level, the flow rate is increased by 1 m 2 When the ultraviolet radiation flux per unit area is changed, the degree of improvement in the air sterilization performance with an increase in the radiation flux per unit area is 3 / min. Therefore, when the flow rate of air in the treatment space 15 is kept constant, the flow rate of air per square meter in the cross section perpendicular to the flow direction is 2 The UV radiation flux per unit is 6000mW / m 2 It was confirmed that within the above range, even if the ultraviolet radiation flux per unit area is increased, the degree of improvement in the sterilization performance of the air tends to be small. And, when the air flow rate in the treatment space 15 is kept constant, 2 The UV radiation flux per unit is 20,000 mW / m 2 It was confirmed that over a larger range, even if the ultraviolet radiant flux per unit area is changed, the air sterilization performance tends to not change, or to change very little.

[0051] In this embodiment, the fan 6 is operated to increase the airflow in the processing space 15 by 1 m 3An air flow is formed from the inlet 3 to the outlet 5 at a flow rate of 1 m 3 / min or more. Then, by operating the ultraviolet light source 13, the air flow is reduced by 1 m 3 / min. 2 The radiant flux per unit is 6000mW / m 2 In this state, ultraviolet rays are radiated into the treatment space 15. When performing air treatment using the air treatment device 1, the first verification and the like show that the flow rate of air in the treatment space 15 is set to 1 m 3 / min or more, the improvement in the sterilization performance of the air tends to be small even if the air flow rate is increased. 2 The radiant flux per unit is 6000mW / m 2 Within the above range, even if the ultraviolet radiant flux per unit area is increased, the degree of improvement in the sterilization performance of the air tends to be small.

[0052] For this reason, the flow rate of air in the processing space 15 is set to 1 m 3 / min or more, and the ultraviolet radiation flux per unit area is 6000mW / m 2 By setting the air flow rate to 1 m or more, air treatment including sterilization can be performed with a relatively high level of performance within the feasible range. 3 / min or more, and the ultraviolet radiation flux per unit area is 6000mW / m 2 By carrying out the above steps, sterilization is appropriately carried out in the treatment space 15 using ultraviolet rays.

[0053] In addition, the air flow rate is 1m 3 / min or more, and the ultraviolet radiation flux per unit area is 6000mW / m 2 By setting the ultraviolet ray flux per unit area at 20,000 mW / m or more, sterilization can be appropriately performed using ultraviolet rays without excessively increasing the ultraviolet ray flux per unit area. For example, 2 Sterilization is appropriately performed using ultraviolet light while keeping the ultraviolet radiation flux per unit area below 100 nm. By not making the ultraviolet radiation flux per unit area excessively large, heat generation at the ultraviolet light source 13 is effectively suppressed. As a result, temperature rise and the like in the vicinity of the ultraviolet light source 13 in the air treatment device 1 is effectively suppressed.

[0054] In addition, since there is no need to excessively increase the radiant flux of ultraviolet light per unit area, it is possible to reduce, for example, the number of light-emitting elements provided in the ultraviolet light source 13. This makes it possible to reduce the effort and cost required for manufacturing the ultraviolet light source 13.

[0055] In one embodiment, 2 The radiant flux per unit is 20,000 mW / m 2 In the state where the ultraviolet light source 13 is irradiated into the processing space 15, the ultraviolet light is irradiated from the ultraviolet light source 13 to the processing space 15. 2 The UV radiation flux per unit is 20,000 mW / m 2 In a larger range, even if the ultraviolet radiation flux per unit area in a cross section perpendicular to the air flow direction is changed, the air sterilization performance tends to not change or to change very little. Therefore, an increase in the ultraviolet radiation flux to a degree that does not contribute to improving the air treatment performance is effectively prevented. This effectively prevents an excessive increase in the amount of heat generated by the ultraviolet light source 13 to a degree that does not contribute to improving the air treatment performance.

[0056] In one embodiment, the ultraviolet light source 13 radiates ultraviolet light into the processing space 15 with a peak wavelength of 280 nm. When ultraviolet light is radiated 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 6000mW / m 2 By doing the above, air treatment including sterilization of the air can be performed appropriately with high performance as described above.

[0057] In one embodiment, at least the inner surface of the housing 2 is made of a material having a high ultraviolet reflectance. This effectively prevents the ultraviolet rays from being emitted to the outside of the housing 2, and more efficiently sterilizes the treatment space 15 using the ultraviolet rays.

[0058] In addition, 6000mW / m 2 More than 20,000mW / m2 The following ranges are appropriate ranges for the radiant flux per unit area when ultraviolet light is emitted from the ultraviolet light source 13 at a peak wavelength of 280 nm. In the embodiment, an appropriate range is adjusted and corrected for the ultraviolet radiant flux per unit area in a cross section perpendicular to the flow direction, corresponding to the peak wavelength of the ultraviolet light. At this time, the appropriate range for the ultraviolet radiant flux per unit area is corrected based on the relationship between the peak wavelength of the ultraviolet light and the inactivation sensitivity of bacteria (DNA of bacteria, etc.).

[0059] 6 and 7 show an example of the relationship between the peak wavelength of ultraviolet light and the inactivation sensitivity. In FIG. 6, the relationship between the peak wavelength of ultraviolet light and the inactivation sensitivity is shown in a table. In FIG. 7, the relationship between the peak wavelength of ultraviolet light and the inactivation sensitivity is shown in a graph with the horizontal axis representing the peak wavelength and the vertical axis representing the inactivation sensitivity. In FIG. 6 and FIG. 7, the peak wavelength is shown in nm, and the inactivation sensitivity is shown as a ratio to the inactivation sensitivity when the peak wavelength is 263 nm. That is, the inactivation sensitivity is shown with the value of the inactivation sensitivity when the peak wavelength is 263 nm set to 1. In FIG. 6, the value of the inactivation sensitivity for the peak wavelength of ultraviolet light is shown at 5 nm intervals in the range of 230 nm or more and 315 nm or less. In FIG. 7, the data points corresponding to the peak wavelengths shown in FIG. 6 and the curve γ connecting the data points are shown.

[0060] In one example, such as in Figures 6 and 7, when the peak wavelength of the ultraviolet light is 263 nm, the inactivation sensitivity is the highest, which is the peak value. The peak wavelength is the variable λ, and the inactivation sensitivity is the variable ε. In one example, such as in Figures 2 and 3, when the peak wavelength is in the range of 230 nm or more and 263 nm or less (230 nm ≦ λ ≦ 263 nm), the relationship of formula (1) is established. When the peak wavelength is in the range of 263 nm or more and 315 nm or less (263 nm ≦ λ ≦ 315 nm), the relationship of formula (2) is established. Therefore, it is possible to calculate the inactivation sensitivity ε from the peak wavelength λ using the relationships such as formulas (1) and (2).

[0061]

number

[0062] Here, for the ultraviolet radiation flux per unit area, the appropriate range when the peak wavelength λ is 280 nm is corrected to the appropriate range when the peak wavelength λ is the value λa. In this case, the value εa of the inactivation sensitivity ε when the peak wavelength λ is the value λa is calculated using formula (1) or formula (2). Then, the inactivation sensitivity ratio ηa is calculated, which is the ratio of the value εa to 0.7, which is the inactivation sensitivity ε when the peak wavelength λ is 280 nm. That is, the inactivation sensitivity ratio ηa is calculated using formula (3).

[0063] In addition, the lower limit Iamin and upper limit Iamax of the appropriate range for the ultraviolet radiant flux per unit area in a cross section perpendicular to the air flow direction are specified when the ultraviolet peak wavelength λ is λa. The lower limit Iamin is 6000 mW / m2, which is the lower limit of the appropriate range when the peak wavelength λ is 280 nm. 2 , and the calculated inactivation sensitivity ratio ηa are used to calculate the upper limit Imax as shown in formula (4). The upper limit Imax is 20000 mW / m 2 Using the calculated inactivation sensitivity ratio ηa, it is calculated as shown in formula (5). This allows the calculation of an appropriate range for the ultraviolet radiant flux per unit area in a cross section perpendicular to the air flow direction, where the peak wavelength λ is the value λa.

[0064]

number

[0065] For example, in calculating the appropriate range for the ultraviolet radiant flux per unit area when the peak wavelength λ is 265 nm, the inactivation sensitivity ε is calculated to be 0.99, and the inactivation sensitivity ratio ηa is calculated to be 1.41 using equation (3). Then, using equations (4) and (5), the lower limit Iamin of the appropriate range for the ultraviolet radiant flux per unit area is calculated to be 4255 mW / m 2However, the upper limit of the appropriate range, Iamax, is 14184mW / m 2 As a result, the appropriate range for the radiant flux per unit area when the peak wavelength is 280 nm is 4255 mW / m 2 or more and 14184mW / m 2 The correction is made to the following range:

[0066] When the peak wavelength λ of the ultraviolet light from the ultraviolet light source 13 becomes λa, the flow rate of air in the processing space 15 is set to 1 m 3 / min or more, and the radiant flux of ultraviolet light per unit area is set to the aforementioned lower limit value Iamin or more. When the peak wavelength λ of ultraviolet light from the ultraviolet light source 13 becomes the value λa, in a preferred example, the radiant flux of ultraviolet light per unit area is set to the aforementioned upper limit value Iamax or less. By carrying out air treatment including sterilization of the air under such conditions, the same actions and effects as those of the above-mentioned embodiment in which the peak wavelength λ of ultraviolet light from the ultraviolet light source 13 becomes 280 nm can be achieved.

[0067] According to at least one of these embodiments, the fan is adapted to rotate at a rate of 1 m 3 An air flow is formed from the inlet to the outlet with a flow rate of 1 / min or more. The ultraviolet light source is placed within a 1m 2 The radiant flux per unit is 6000mW / m 2 In this state, ultraviolet light is emitted into the treatment space. This makes it possible to provide an air treatment device that appropriately sterilizes the treatment space using ultraviolet light while suppressing heat generation in the ultraviolet light source.

[0068] Although some embodiments of the present invention have been described, these embodiments are presented 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 modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0069] 1...air treatment device, 2...housing, 3...inlet, 5...exhaust, 6...fan, 13...ultraviolet light source, 15...treatment space.

Claims

1. a housing having an inlet for introducing air into an interior thereof and an outlet for discharging the air to an exterior thereof, a processing space being formed in a path of the air from the inlet to the outlet, and a cross-sectional area of ​​the processing space perpendicular to a flow direction of the air being uniform; By operating the device, the processing space is expanded by 1 m ３ a fan that forms the air flow from the inlet to the outlet at a flow rate of at least 100 / min; By operating the airflow, the airflow ２ The radiant flux per unit is 6000mW / m ２ an ultraviolet light source that radiates ultraviolet light into the processing space in the above state; An air treatment device comprising:

2. The ultraviolet light source is operated to ２ The radiant flux per unit is 20,000 mW / m ２ 2. The air treatment system of claim 1, wherein the system irradiates the treatment space with ultraviolet light such that:

3. 3. The air treatment device of claim 1, wherein the ultraviolet light source is activated to emit ultraviolet light into the treatment space at a peak wavelength of 280 nm.

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