Inactivation sterilization device

Abstract

To provide an inactivation sterilization device with a large air flow that is preferably suited for inactivating and / or sterilizing objects contained in intake air.SOLUTION: An inactivation sterilization device 1 comprises a filter 6 that filters intake air with feasible ventilation resistance, an ultraviolet irradiation light source 13 that irradiates the intake air filtered by the filter 6 with ultraviolet light, a blower fan 11 that discharges the intake air W after the ultraviolet irradiation at a maximum airflow rate of at least 9 m3 / min, and a housing 2 that stores the ultraviolet irradiation light source 13 and the blower fan 11.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to an inactivation sterilization device. [Background technology]

[0002] In recent years, as a measure against the spread of respiratory diseases, there has been an increasing need to inactivate and disinfect viruses in spaces such as public facilities and offices. A known sterilization technique for inactivating and disinfecting viruses is to take air into a device and irradiate it with ultraviolet light. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-27412 Summary of the Invention [Problem to be solved by the invention]

[0004] When air is drawn into the device, filtering it with a HEPA (High Efficiency Particulate Air) filter is effective in removing dust, but it can result in a decrease in airflow. A decrease in airflow reduces the device's overall ability to inactivate and sterilize viruses and other microorganisms in a closed space, and there is a risk that sufficient performance will not be achieved. The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide an inactivation and sterilization device that has a large air volume and is suitable for inactivating and / or sterilizing objects contained in the intake air. [Means for solving the problem]

[0005] In order to achieve the above object, an inactivation and sterilization device is provided which irradiates ultraviolet light onto intake air drawn into the device to inactivate and / or sterilize objects contained in the intake air, the device comprising: a filter which filters the intake air with a ventilation resistance that can realize the intake air; an ultraviolet light irradiation light source which irradiates the ultraviolet light onto the intake air filtered by the filter; and a maximum air volume of 9.0 m3 of the intake air after ultraviolet light irradiation. 3 The inactivation sterilization device includes a blower fan that exhausts air at a rate of 1 / min or more, and a housing that houses the ultraviolet irradiation light source and the blower fan. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide an inactivation and sterilization device that has a large air volume and is suitable for inactivating and / or sterilizing targets contained in intake air. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram showing the appearance of an inactivation sterilization apparatus according to an embodiment. FIG. [Figure 2] FIG. 10 is a view showing the state in which the filter is removed from the housing of the inactivation sterilization device. [Figure 3] FIG. 2 is a top view of the inactivation sterilization device. [Figure 4] FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. [Figure 5] FIG. 4 is a diagram showing a VV cross section of FIG. 3. [Figure 6] FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. 4. [Figure 7] FIG. 2 is a diagram showing the reflection characteristics of an ultraviolet reflecting material. [Figure 8] FIG. 4 is a diagram illustrating a limit switch and a control unit. [Figure 9] FIG. 10 is a diagram showing the fixation prohibition structure together with the surrounding configuration from a diagonal view from below. [Figure 10] FIG. 10 is a view showing the locking prohibition structure from below. [Figure 11] 10A and 10B are diagrams illustrating the effect of an ultraviolet reflecting material, which is a reflecting material. [Figure 12]10A and 10B are diagrams illustrating the effect of an ultraviolet reflecting material, which is a reflecting material. [Figure 13] FIG. 1 is a diagram illustrating the logarithmic reduction rate excluding natural attenuation due to relative humidity. [Figure 14] FIG. 14 is a diagram illustrating the reduction in residual infectivity titer after 15 minutes in FIG. 13. [Figure 15] FIG. 1 is a diagram illustrating the inactivation effect on human coronaviruses. [Figure 16] FIG. 1 is a diagram illustrating the inactivation effect on influenza viruses. [Figure 17] FIG. 17 is a diagram showing the respective numerical values ​​of FIG. 16. [Figure 18] FIG. 1 is a diagram showing test results of a removal performance evaluation test. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [1. Overall configuration of the inactivation sterilization device] FIG. 1 is a diagram showing the appearance of an inactivation sterilization apparatus 1 according to an embodiment. The inactivation sterilization apparatus 1 shown in Figure 1 comprises a housing 2 that is placed on the floor, with an air intake port 3 on the side of the housing 2 that draws in ambient air, and an air outlet 4 on the top of the housing 2 that blows out the drawn-in air. In this explanation, the directions described are those when the inactivation sterilization apparatus 1 is installed. The housing 2 has a cylindrical shape that extends in the vertical direction (the Z-axis direction in FIG. 1), and more specifically, has a rectangular cylindrical shape with four side surfaces. Of the four side surfaces, three side surfaces (the side surfaces located in the X-direction, Y-direction, and -X-direction in FIG. 1) are provided with air intake ports 3. The side surfaces opposite the air intake ports 3 are provided with grip portions 5 that can be held by users (including installation workers and maintenance workers). The shape of the housing 2 may be modified as appropriate.

[0009] Each air intake 3 is formed in a rectangular shape. The height H of each air intake 3 is set to 100 mm or more, more preferably 150 mm or more, from the bottom of the inactivation sterilization apparatus 1 (corresponding to the height from the floor on which the inactivation sterilization apparatus 1 is installed). This gives priority to suctioning air at a higher position than the air around the bottom of the inactivation sterilization apparatus 1, making it easier to efficiently circulate air in the space where the inactivation sterilization apparatus 1 is installed. It also makes it possible to prevent a decrease in device performance due to suctioning dust and other particles accumulated on the floor. The number and shape of the air intake 3 may be changed as appropriate.

[0010] Each air intake 3 is provided with a filter 6 for filtering out dust. FIG. 2 shows the state in which the filters 6 have been removed from the housing 2. Each filter 6 is attached to a fixing frame 7A, 7B, 7C, and can be attached to and detached from the housing 2 via the fixing frames 7A, 7B, 7C. The fixing frames 7A, 7C are made of filter frames that hold the filters 6 and have multiple claws 8, and are fixed to each side of the housing 2 via these claws 8. Fixed frame 7B includes a filter frame 7B1 having the same structure as fixed frames 7A and 7C, and a cover 7B2 to which filter frame 7B1 is fixed. Filter frame 7B1 is fixed to cover 7B2 via a plurality of claws 8, and cover 7B2 is removably fixed to the side of housing 2. Filter frame 7B1 cannot be disengaged from the engagement state of claws 8 unless accessed from the back side of cover 7B2. Therefore, when removing filter 6 from housing 2, filter 6 must be removed together with cover 7B2 from housing 2. In the following description, when there is no need to distinguish between fixed frames 7A, 7B, and 7C, they will be referred to as fixed frame 7.

[0011] The filter 6 is a type of electrostatic filter, a charged filter, that functions as a dust filter that captures dust in the air using electrostatic force. The filter 6 is formed from a filter material composed of an electrically charged nonwoven fabric in which microfibers are electrostatically charged. This filter can effectively capture dust in the air, achieving high collection efficiency with low airflow resistance. The filter 6 is, for example, the ELITOLON (registered trademark) dust filter manufactured by Toyobo MC Co., Ltd., and can remove particulate matter with a particle size of 0.1 μm or greater. This allows it to capture at least a portion of particulate matter, such as airborne viruses such as coronaviruses and influenza viruses, as well as microorganisms with a particle size of several μm, and pollen.

[0012] The filter 6 has an initial pressure loss of 1.5 Pa or less, and more preferably an initial pressure loss of 1.0 Pa or less, when the air volume is at a wind speed of 5.3 cm / sec. The filter 6 is not limited to a filter medium made of an electrically charged nonwoven fabric in which static electricity is maintained in microfibers. The filter 6 may be a "9.0 m" filter according to the present invention. 3 It is equivalent to a "filter that filters intake air with ventilation resistance that can achieve a maximum airflow of 1 / min or more."

[0013] Fig. 3 is a top view of the inactivation and sterilization apparatus 1. Fig. 4 is a view showing a cross section taken along line IV-IV in Fig. 3, and Fig. 5 is a view showing a cross section taken along line VV in Fig. 3. In each figure, the symbol CT denotes a central axis passing through the center of the inactivation and sterilization apparatus 1 in the front-rear and left-right directions. As shown in Figures 3 and 4, the inactivation sterilization device 1 is equipped with a blower fan 11, an internal light body 12, an ultraviolet irradiation light source 13 housed in the internal light body 12, and a duct 14 connecting the blower fan 11 and the internal light body 12 inside the housing 2.

[0014] The blower fan 11 is disposed directly below the air outlet 4 and blows air below the blower fan 11 upward toward the air outlet 4. The rotation axis 11A of the blower fan 11 (see FIG. 5) coincides with the central axis CT, but may not coincide with the central axis CT. As shown in FIG. 3, the air outlet 4 has slits 4A spaced apart in the X direction and slits 4B spaced apart in the Y direction. The area corresponding to the central axis CT is blocked, and an operation panel is installed in this area. These slits 4A and 4B restrict access to the blower fan 11 from the outside while blowing out air. The ventilation control plates 4A1 and 4B1 that form the slits 4A and 4B are inclined, for example, at approximately 60 degrees relative to the positive direction of the Z axis, and have the effect of adjusting the direction of the airflow and rectifying the airflow. The shape and structure of the air outlet 4 may be modified as appropriate.

[0015] As shown in Fig. 4, the internal light body 12 that irradiates ultraviolet light is disposed below the blower fan 11 and is formed in a cylindrical hollow box that extends in the vertical direction. By operating the blower fan 11, negative pressure is created inside the internal light body 12, and air flows from below the internal light body 12 to above it. A recess 2T is provided in the lower part of the housing 2 located below the internal light body 12, recessed downward at intervals in the circumferential direction based on the central axis CT. Furthermore, gaps 2S are provided between the internal light body 12 and the housing 2, opening in the front, rear, left and right directions. These gaps 2S communicate with the recess 2T and the intake port 3.

[0016] By operating the blower fan 11, intake air W consisting of the air around the housing 2 is sucked in through each intake port 3, and dust is removed from the intake air W by the filter 6 provided at each intake port 3. The flow of the intake air W is indicated by arrows in Figure 4. The intake air W from which dust has been removed flows downward through an intake passage extending in the vertical direction consisting of the gap 2S, flows into the circulation flow path consisting of the recess 2T, changes the direction of the air flow from downward to upward along the circulation flow path, and flows into the internal light body 12.

[0017] As shown in Fig. 4, the recess 2T is formed in a concave shape along a circular arc. Therefore, the intake air W from the intake port 3 can be smoothly guided toward the inside of the internal light body 12, which is advantageous for reducing air resistance and increasing the air volume. The shape of the recess 2T may be changed. Further, recess 2T is formed in a concave shape such that even if light from ultraviolet irradiation light source 13 is incident and reflected, the reflected light does not reach intake port 3 at a height H or more.

[0018] Two ultraviolet irradiation light sources 13 are housed in the inner light body 12 and aligned in the vertical direction. The ultraviolet irradiation light sources 13 are light sources that irradiate ultraviolet light onto the air passing through the internal light body 12, and in this embodiment, are provided around the central axis CT of the internal light body 12. More specifically, the ultraviolet irradiation light sources 13 are provided at intervals in the X direction and are provided at positions that overlap with the central axis CT when viewed from the Y direction. The ultraviolet irradiation light source 13 is, for example, a mercury lamp, an excimer lamp, a solid-state excitation light emitting element, or a deep ultraviolet LED. The wavelength of the irradiated light is in the range of 100 nm to 400 nm. It is particularly desirable to irradiate light in the deep ultraviolet region, which has a high virus inactivation and sterilization effect and generates little ozone, that is, light with a wavelength in the range of 200 nm to 300 nm. The ultraviolet irradiation dose of the ultraviolet irradiation light source 13 is 4 mJ / cm. 2 That's all.

[0019] Because the ultraviolet irradiation light sources 13 are shaped to extend vertically and there are multiple sources, it is possible to reduce air resistance while increasing the amount of ultraviolet light irradiated onto the intake air W. Furthermore, the internal light bodies 12 extend vertically and form an air passage that flows the intake air W in the vertical direction, allowing the intake air W to flow smoothly upward. As a result, an air passage that flows smoothly through the intake air W while irradiating it with light from the ultraviolet irradiation light sources 13 is formed, which is advantageous for inactivating and / or sterilizing viruses contained in the intake air W and for increasing the air volume. The internal light body 12 constitutes one component of a housing structure that houses the ultraviolet irradiation light source 13. This housing structure makes it possible to prevent light from the ultraviolet irradiation light source 13 from leaking.

[0020] Duct 14 forms an air passage connecting the upper part of internal light body 12 and the lower part of blower fan 11. This duct 14 prevents light from ultraviolet irradiation light source 13 from leaking to the outside from between internal light body 12 and blower fan 11, and allows air to flow smoothly from internal light body 12 toward blower fan 11.

[0021] 4, in this configuration, the height H of each air intake 3 is set higher than the bottom surface of the internal light body 12, so even if the light from the ultraviolet irradiation light source 13 is reflected by the recess 2T, it is difficult for the light to reach the air intake 3. In other words, in this configuration, the height H of each air intake 3 and the shape of the recess 2T are set to prevent the light from the ultraviolet irradiation light source 1340 from reaching the air intake 3, thereby preventing deterioration of the filter 6, leakage of ultraviolet light, etc.

[0022] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. As shown in Fig. 6, the internal light body 12 has a circular cross section and can be divided into two parts horizontally (corresponding to the X direction) based on a dividing line L1 extending in the Y direction shown in Fig. 6. A pair of ears 21m, 22m that protrude radially outward are provided at the butt joint 23 of each divided piece 21, 22 across the top and bottom of the internal light body 12. 6, the ear 21m has a first portion 21a extending along the Y direction and a second portion 21b extending along the −X direction perpendicular to the radially outer end of the first portion 21a. The other ear 22m has a first portion 22a extending along the Y direction. When the segments 21, 22 are butted together, the first portions 21a, 22a overlap each other in the X direction, thereby positioning the segments 21, 22 in the X direction, and the end of the first portion 22a abuts against the second portion 21b, thereby positioning the segment 22 relative to the segment 21 in the Y direction.

[0023] The housing 2 is provided with a clamping portion 2k that clamps the ears 21m, 22m of each of the divided pieces 21, 22. The clamping portion 2k clamps the first portions 21a, 22a of the ears 21m, 22m using bolts 2v. Since the first portions 21a, 22a of the ears 21m, 22m are kept overlapping, light from the ultraviolet irradiation light source 13 is less likely to leak to the outside from the butt joints 23 of the divided pieces 21, 22. Furthermore, the second portion 21b of the ear portion 21m covers the gap between the first portions 21a, 22a from the radially outer end, making it more difficult for light from the ultraviolet irradiation light source 13 to leak to the outside. This prevents the light from the ultraviolet irradiation light source 13 from leaking to the outside from the butt joint 23 of the divided pieces 21, 22 of the internal light body 12. The internal light body 12 is also positioned relative to the housing 2 by the above structure. In addition, the upper end PU and lower end PL of the internal light body 12 have protrusions 12T that protrude in the vertical direction and in the inner circumferential direction (horizontal direction), and these protrusions 12T also make it difficult for light from the ultraviolet irradiation light source 13 to leak to the outside.

[0024] An ultraviolet reflector 31 is fixed to the inner surface of each of the divided pieces 21, 22 that make up the internal light body 12 via an adhesive layer or by fixing parts such as screws or rivets. The ultraviolet reflector 31 reflects the light from the ultraviolet irradiation light source 13 inside the internal light body 12, thereby increasing the sterilization efficiency of the intake air W within a limited space. Furthermore, because the ultraviolet reflector 31 is attached or fixed by a fixing part, it is easy to replace the ultraviolet reflector 31. Furthermore, because the internal light body 12 has a two-part structure, it is easy to access the ultraviolet irradiation light source 13 and the ultraviolet reflector 31, making maintenance such as part replacement easy.

[0025] The UV reflector 31 is a highly reflective material (also referred to as highly reflective aluminum material) made of aluminum foil, and is a highly smooth aluminum foil with a surface roughness of 10 μm or less, a specular gloss of 83% or more, and a deep UV reflectance of 83% or more. The specular gloss is measured (at 60°) using a specular glossmeter. The UV reflector 31 is, for example, LUXAL (registered trademark) from Toyo Aluminum K.K.

[0026] FIG. 7 is a diagram showing the reflection characteristics of the ultraviolet reflective material 31. As shown in FIG. 7, symbol f1 indicates the reflection characteristic of ultraviolet reflecting material 31, symbol f2 indicates the reflection characteristic of the first reflecting material made of stainless steel alloy foil, and symbol f3 indicates the reflection characteristic of the second reflecting material made of copper foil. The reflectances shown in Fig. 7 are integrating sphere total reflectances. As shown in Figure 7, the reflectance of the ultraviolet reflector 31 is a total reflectance of 80% or more for deep ultraviolet light, which is higher than the first and second reflectors. Because the reflectance of ultraviolet light is high, the amount of ultraviolet light irradiated inside increases, which is advantageous for improving the sterilization and inactivation effects in a single pass. Note that Figure 7 shows a case where the reflectance of the ultraviolet reflector 31 is 80% or more for ultraviolet light of 250 to 380 nm, but is not limited to this reflection characteristic, and it is preferable that the total reflectance be 80% or more for deep ultraviolet light of 200 to 300 nm.

[0027] In addition, an ultraviolet-responsive photocatalyst may be supported on the surface of the ultraviolet reflecting material 31, and the oxidizing action of this photocatalyst may improve the virus inactivation effect, sterilization effect, etc., or may impart anti-fogging, anti-fouling, and self-cleaning properties. The blower fan 11 draws in intake air W into the housing 2 at a maximum air volume of 9.0 m 3 / min or more.

[0028] If a HEPA filter were used as the filter 6, the particle capture rate would be high, but the initial pressure loss would be large, resulting in a decrease in airflow. To avoid this decrease in airflow, a large, powerful blower fan 11 would need to be used, which would be disadvantageous to downsizing and energy conservation. Although the particle capture rate is lower than that of a HEPA filter, the use of a filter 6 with a small initial pressure loss, as in the inactivation and sterilization device 1 according to this embodiment, allows for a smaller, more energy-efficient, and quieter blower fan 11. Furthermore, since the maximum airflow volume can be increased, a large amount of indoor air can be drawn in and sterilized, enabling the capture of viruses and the like in indoor air in a shorter time than devices equipped with HEPA filters with a smaller airflow volume. Furthermore, combining this with ultraviolet irradiation is advantageous for the inactivation and / or sterilization of coronaviruses and influenza viruses.

[0029] [2. Configuration for fixing filter 6] Next, the structure for fixing the filter 6 will be described. As shown in Fig. 2, of the fixed frames 7A, 7B, and 7C, the fixed frame 7B is a fixed frame that is fixed to the side surface corresponding to the rear surface of the housing 2. As shown in Fig. 8, the housing 2 is provided with a plurality of limit switches 41 that function as sensors for detecting fixation of the fixed frame 7B. The switch states of these limit switches 41 are switched by inserting protrusions 42 provided on the fixing frame 7B. These switch states are detected by the control unit 43. The control unit 43 is a device that controls the operation of each part of the inactivation sterilization apparatus 1, and controls at least the on / off (on / off) of the ultraviolet irradiation light source 13.

[0030] When the control unit 43 detects via the limit switch 41 that the fixed frame 7B is not fixed, it controls the ultraviolet irradiation light source 13 to be turned off (turned off), thereby preventing the ultraviolet irradiation light source 13 from being turned on when the fixed frame 7B is not fixed.

[0031] Furthermore, the inactivation sterilization apparatus 1 has a fixing prohibition structure 51 that prohibits fixing of the fixing frame 7B to the housing 2 when the fixing frames 7A and 7C among the multiple fixing frames 7A, 7B, and 7C are not fixed to the housing 2. The fixing frames 7A and 7C correspond to the "predetermined fixing frames" of the present invention, and the fixing frame 7B corresponds to the "other fixing frames" of the present invention.

[0032] Fig. 9 is a diagram showing the locking prohibition structure 51 of fixed frame 7A together with the surrounding configuration from diagonally below. Fig. 10 is a diagram showing the locking prohibition structure 51 from below. Note that the locking prohibition structure 51 of fixed frame 7C is the same as the locking prohibition structure 51 of fixed frame 7A, so a description of the locking prohibition structure 51 of fixed frame 7A will be omitted. 9 and 10, the locking-inhibiting structure 51 is disposed in the space between the fixed frames 7A and 7B inside the housing 2. The locking-inhibiting structure 51 has a swinging member 52 that comes into contact with the fixed frame 7A immediately before it is fixed. The swinging member 52 is supported by a swinging shaft 53 so that one end 52a of the swinging member 52 can swing freely up to a position where it comes into contact with a first protrusion 7t that is part of the fixed frame 7A. The locking-inhibiting structure 51 has a biasing member 54 that biases the swinging member 52 toward the position where it comes into contact with the first protrusion 7t (the -α side in FIG. 10).

[0033] In FIG. 10, the swinging member 52 when the fixed frame 7A is not fixed to the housing 2 is shown by a two-dot chain line, and the swinging member 52 when the fixed frame 7A is fixed to the housing 2 is shown by a solid line. 10, the other end 52b of the swinging member 52 is formed in a bent shape that is bent so as to restrict movement of the second protrusion 7v, which is part of the fixed frame 7B, in the γ direction when the fixed frame 7A is not fixed to the housing 2. As a result, when the fixed frame 7A is not fixed to the housing 2, the other end 52b of the swinging member 52 prevents the fixed frame 7B from being fixed to the housing 2.

[0034] In contrast, when the fixed frame 7A is fixed to the housing 2, one end 52a of the swinging member 52 moves to the α side against the biasing force of the biasing member 54, so the other end 52b of the swinging member 52 moves in the β direction, allowing the second protrusion 7v, which is part of the fixed frame 7B, to move in the γ direction. This makes it possible to fix the fixed frame 7B to the housing 2.

[0035] In this way, a fixation prohibition structure 51 is realized that prevents fixation of fixation frame 7B to housing 2 when a pair of fixation frames 7A, 7C provided on opposing side surfaces are not fixed to housing 2. As described above, the inactivation sterilization apparatus 1 cannot be operated unless fixation frame 7B is fixed, and therefore the inactivation sterilization apparatus 1 cannot be operated unless all of fixation frames 7A, B, C are fixed. This prevents a situation in which the blower fan 11 or ultraviolet irradiation light source 13 is operated when any of fixation frames 7A, B, C is removed.

[0036] After removing the fixed frame 7B, the fixed frames 7A and 7C can be removed from the housing 2 by disengaging the claws 8 of the fixed frames 7A and 7C from inside the housing 2. However, the fixing structure of the filter 6, including the fixing structure of the fixed frames 7A to 7C, may be changed as appropriate.

[0037] [3. Test Results] Next, the test results of the inactivation sterilization device 1 will be explained. The test measurement procedure is 24m 2 After cleaning the environmental test chamber to Class 10 level with six HEPA fan filter units, approximately 3cc of a specified virus liquid was sprayed into the environmental test chamber, and 120 liters of air was sucked in at a specified position in the environmental test chamber at 0, 15, 30, and 60 minutes to capture the suspended viruses on a gelatin filter. The captured gelatin filter was immediately dissolved in a medium liquid and the infectivity titer (TCID50) was measured. The specified virus liquid was a liquid containing human coronavirus, influenza virus, or viruses that can be considered to be these viruses.

[0038] 11 and 12 show test results showing the effect of the ultraviolet reflective material 31, which is a highly reflective material. 11, the inactivation sterilization apparatus 1 of Example 1 is configured to use EFR15L, a dustproof filter made by Toyobo MC Co., Ltd., as the filter 6. The EFR15L has an initial pressure loss of 0.8 Pa under conditions of an air velocity of 5.3 cm / sec. 11, the inactivation sterilization apparatus 1 of Comparative Example 1 is configured to use EFR80L, a dustproof filter manufactured by Toyobo MC Co., Ltd., as the filter 6. The EFR80L has an initial pressure loss of 4.0 Pa under conditions of an air velocity of 5.3 cm / sec.

[0039] 11 shows the logarithmic reduction rate (D / min) and efficacy ratio of TCID50 (Tissue Culture Infectious Dose 50) depending on the presence or absence of the UV reflecting material 31 for Example 1 and Comparative Example 1. TCID50 indicates the 50% tissue culture cell infectivity rate and is one of the measurement methods used to measure the infectivity titer of a target virus. 11, the logarithmic reduction rate of Example 1, which uses Filter 6 with low initial pressure loss, is 0.193 (D / min) without a highly reflective material and 0.220 (D / min) with a highly reflective material. The effectiveness ratio (0.220 / 0.193×100) is 114.0%. In contrast, the logarithmic reduction rate of Comparative Example 1, which used Filter 6 with a high initial pressure loss, was 0.146 (D / min) without a highly reflective material and 0.174 (D / min) with a highly reflective material. The effectiveness ratio (0.174 / 0.146×100) was 118.6%.

[0040] In Example 1, the air volume of the blower fan 11 is 9.15 m 3 In contrast, in Comparative Example 1, the airflow resistance of the filter 6 was large, so the airflow rate of the blower fan 11 was 7.99 m 3 Theoretically, the factor that influences the effect of reducing the airborne particle concentration in a space based on filter filtration is the product of the filtered air volume per hour Q and the collection efficiency η. 3 By ensuring a high air volume of at least / min, it is possible to obtain a higher reduction effect in the airborne particle concentration in the space than in Comparative Example 1, and a high reduction effect can be obtained without using a HEPA filter or the like with a high collection efficiency η.

[0041] FIG. 12 shows the change over time in the net logarithmic reduction value D (log value) in Example 1. The net logarithmic reduction value D (log value) is (logarithmic reduction value during test sample operation) - (control value (logarithmic reduction value of natural attenuation)). The logarithmic reduction value during test sample operation is log 10 (initial virus infectivity / virus infectivity at each elapsed time). As shown in FIG. 12, it is clear that higher performance can be obtained by using ultraviolet reflective material 31 made of a highly reflective material.

[0042] FIG. 13 shows the change over time in the logarithmic reduction rate (D / min) excluding natural attenuation due to relative humidity in the configuration of Example 1 with a highly reflective material, and FIG. 14 shows the reduction value of the residual infectivity titer (hereinafter referred to as infectivity titer) 15 minutes after the time of FIG. 13 . At relative humidity levels of 20%, 50%, and 70%, the "infectivity titer (Control)" after 15 minutes decreased to 82.1%, 31.7%, and 42.9% compared to the level at 0 minutes. Like influenza viruses, human coronaviruses are "enveloped RNA viruses" that tend to lose activity (also known as inactivation) over time in high-humidity environments, but are more difficult to inactivate in low-humidity environments than high-humidity environments, meaning that the risk of infection is relatively higher.

[0043] When UV irradiation was added, the infectivity titer due to relative humidity was significantly reduced to 2.2%, 0.7%, and 1.0%, as shown by the infectivity titer (Test in Figure 14). This indicates that the infectivity titer was reduced to 2.7%, 2.2%, and 2.3% of the control value under relative humidity conditions of 20%, 50%, and 70%, respectively. These results suggest that there was not much difference in the rate of reduction in infectivity titer caused by UV irradiation, regardless of dry or wet conditions, and that the inactivation effect of UV is independent of relative humidity. That is, the inactivation sterilization apparatus 1 of Example 1 is little affected by humidity and has a high sterilization ability for the space even in a low humidity environment such as 20%. Generally, the lower the humidity environment, the more difficult it is to inactivate human coronaviruses and influenza viruses, and the defense mechanisms of the human throat and nose are weakened, so the inactivation and sterilization device 1 of Example 1 is effective in reducing the risk of infection.

[0044] FIG. 15 shows the test results showing the inactivation effect on the protein concentration of human coronavirus. Figure 15 shows the logarithmic reduction values ​​for human coronavirus OC43 with a protein concentration of 1.0 wt% and human coronavirus OC43 with a protein concentration of 0.1 wt% in the configuration of Example 1 with a highly reflective material. Figure 15 also shows the logarithmic reduction value for the control (natural decay) of human coronavirus OC43. In FIG. 15, the measurement results for human coronaviruses with protein concentrations of 1.0 wt % and 0.1 wt % are values ​​obtained by subtracting the reduction value of the control.

[0045] 15, at both protein concentrations of 1.0 wt% and 0.1 wt%, the logarithmic reduction of human coronavirus was greater than the control value by more than one order of magnitude. For example, after 20 minutes, the logarithmic reduction of 1.0 wt% human coronavirus was 2.3D or more (=99.5% or more), and the logarithmic reduction of 0.1 wt% human coronavirus was 3D or more (=99.9% or more). Therefore, it is clear that the inactivation and sterilization apparatus 1 of Example 1 is effective for inactivating and / or sterilizing coronaviruses with protein concentrations of 0.1 wt% to 1.0 wt%.

[0046] Figures 16 and 17 show test results showing the airborne influenza virus inactivation effect. Figures 16 and 17 show the logarithmic reduction value of influenza virus at a protein concentration of 1.0 wt% and the logarithmic reduction value of control influenza virus (natural attenuation). In each figure, the measurement results for influenza virus with a protein concentration of 1.0 wt% are values ​​obtained by subtracting the reduction value of the control.

[0047] 16 and 17, the logarithmic reduction value of influenza viruses with a protein concentration of 1.0 wt% is 0.081 (D / min), which is more than an order of magnitude larger than the control value of 0.006 (D / min). For example, the logarithmic reduction value after 20 minutes is 1.6 D or more (97.6% or more), and after 30 minutes is 2.4 D or more (99.6% or more). Therefore, it is clear that the inactivation and sterilization apparatus 1 of Example 1 is effective in inactivating and / or sterilizing influenza viruses with a protein concentration of 1.0 wt%. Experimental results on human coronavirus protein concentration also clearly show that even a low concentration of 0.1 wt% is effective in inactivating and / or killing influenza viruses.

[0048] Furthermore, because of differences in susceptibility to inactivation by UV light depending on the type of virus, it is clear that the human coronavirus, which has high sensitivity and a high inactivation rate, has a larger log reduction in inactivation than the influenza virus. In any case, it is clear that the inactivation and sterilization apparatus 1 of Example 1 is effective in inactivating and / or sterilizing various viruses.

[0049] [4. Single-pass UV irradiation amount] For the inactivation sterilization device 1 of Example 1, a test to evaluate the removal performance of airborne bacterial spores was conducted using Bacillus subtilis spores as an indicator bacterium, for which the relationship between the amount of ultraviolet light and the sterilization rate is clear.Based on the test results, the amount of irradiation light (accumulated amount of ultraviolet light) when passing through the device was calculated as the single-pass ultraviolet irradiation amount DL. The conditions and details of the removal performance evaluation test are as follows: Inactivation sterilization device 1 air volume: 9.1 m 3 / min Environmental test chamber dimensions: 30m 2 Test microorganism: Bacillus subtilis spores (ultraviolet wavelength 254 nm, ultraviolet irradiation dose 11.1 mJ / cm 2 (90% (1D) sterilization) Test method: Bacillus subtilis spores were sprayed into the chamber, and the chamber was thoroughly agitated with a fan. The change in the number of bacteria over time was measured with and without the ultraviolet light source 13 operating.

[0050] Figure 18 shows the test results of the removal performance evaluation test. Figure 18 shows the logarithmic reduction of airborne bacteria when the inactivation sterilization device 1 is not in operation (air blower fan ON, ultraviolet irradiation light source OFF) and its approximate straight line as the reduction characteristics of airborne bacteria with the filter 6 alone. Figure 18 also shows the logarithmic reduction of airborne bacteria when the inactivation sterilization device 1 is in operation (air blower fan ON, ultraviolet irradiation light source ON) and its approximate straight line as the reduction characteristics of airborne bacteria with the filter 6 and UV. Figure 18 also shows the logarithmic reduction of airborne bacteria calculated from the difference in the number of bacteria when the inactivation sterilization device 1 is in operation (air blower fan ON, ultraviolet irradiation light source ON) and when the inactivation sterilization device 1 is not in operation (air blower fan ON, ultraviolet irradiation light source OFF) as the reduction characteristics of airborne bacteria with UV alone.

[0051] 18, the approximate curve for filter 6 and UV is y=0.1158x. The approximate curve for filter 6 alone is y=0.0376x. From the difference between these change characteristics, the approximate curve for UV alone can be calculated as y=0.07822x.

[0052] When using the air circulation type inactivation sterilization device 1, the virus concentration and the single-pass ultraviolet irradiation dose DL, which is the amount of light irradiated when passing through the device, have the relationship shown in equation (1). Equation (1) is a formula used when a substance changes into another substance with a certain probability, and is also commonly used in the field of chemistry. In this case, this formula can be applied because it is assumed that bacteria and viruses change into inactivated bacteria and viruses.

[0053]

number

[0054] The UV-only approximation curve (y = 0.07822x) shown in Figure 18 can be substituted into equation (2). By substituting equation (1) into equation (2), the single-pass ultraviolet irradiance DL is 4.34 mJ / cm 2 It can be seen that A=9.1m 3 / min, V=30m 3 , n=11.1mJ / cm 2 is.

[0055]

number

[0056] Generally, the amount of UV light required to inactivate and / or kill the new coronavirus by 99.9% or more is 2.97 mJ / cm 2 or 3.0 mJ / cm 2 It is known that the effectiveness of UV lamps in inactivating novel coronaviruses is confirmed (see, for example, Hiroki Ohge, Department of Infectious Diseases, Hiroshima University Hospital, "Virus Inactivation Test by Ultraviolet Irradiation," 2020; or, Iwasaki Electric Co., Ltd., December 24, 2020, "Effectiveness of our ultraviolet (UV) lamps in inactivating novel coronaviruses confirmed,"<URL:https: / / www.iwasaki.co.jp / NEWS / release / 2020 / CoV-2.html> ). The single-pass ultraviolet irradiation dose DL of the inactivation sterilization device 1 is 3.0 mJ / cm 2 As a result, the inactivation (sterilization) performance of the new coronavirus when passing through this device 1 once (equivalent to one-pass performance or single-pass performance) is 99.9% or more.

[0057] The amount of UV light required to inactivate and / or kill 99.9% or more of influenza viruses is 6.6 mJ / cm 2 It is known that the UV irradiation dose DL of the single pass of the inactivation sterilization device 1 is 4.0 mJ / cm (see, for example, Kaufma, JE, IES Lighting Handbook 5th Ed., 197). 2As described above, the inactivation (sterilization) performance of influenza viruses when passing through the device 1 once (corresponding to one-pass performance or single-pass performance) is 99% or more. From these findings, it is clear that the inactivation and sterilization device 1 is effective in reducing the risk of infection with the new coronavirus and influenza virus.

[0058] The maximum air volume of the intake air W after ultraviolet irradiation of the blower fan 11 is 9.1 m 3 / min or more, the maximum air volume is 9.0 m 3 / min or more, the single-pass UV exposure dose DL is 4.0 mJ / cm 2 The above can be ensured, and sufficient performance can be achieved to effectively reduce the risk of infection with the new coronavirus and influenza viruses.

[0059] As described above, the inactivation sterilization apparatus 1 of this embodiment is configured with the filter 6 that filters the intake air W with a ventilation resistance that can realize the intake air W, the ultraviolet irradiation light source 13 that irradiates the intake air W filtered by the filter 6 with ultraviolet rays, and the intake air W after ultraviolet irradiation has a maximum air volume of 9 m 3 The device is equipped with a blower fan 11 that exhausts air at a rate of 1 / min or more, and a housing 2 that houses an ultraviolet irradiation light source 13 and the blower fan 11, so that it has a large air volume and provides performance that is suitable for inactivating and / or sterilizing objects contained in the intake air W. It should be noted that coronaviruses and influenza viruses are examples of objects that can be inactivated and / or sterilized by the inactivation and sterilization apparatus 1, and it goes without saying that the objects may be other viruses or objects other than viruses.

[0060] Furthermore, the inactivation and sterilization device 1 is disposed inside the housing 2 and has a storage structure for storing the ultraviolet irradiation light source 13, so that leakage of ultraviolet light to the surroundings of the inactivation and sterilization device 1 can be suppressed. In addition, the amount of ultraviolet radiation inside the storage structure is 4.0 mJ / cm 2As described above, the target object can be inactivated and / or sterilized even in a humidity environment with a relative humidity of 20% or more and 70% or less, so high performance can be obtained even in a low humidity environment where inactivation is more difficult than in a high humidity environment, and effective performance can be obtained over a wide humidity range in reducing the risk of infection with the new coronavirus and influenza virus.

[0061] Furthermore, since an ultraviolet reflecting material 31 that reflects ultraviolet rays is detachably fixed to the inner surface of the storage structure, maintenance such as replacement of the ultraviolet reflecting material 31 is easy. Furthermore, the reflectivity of the ultraviolet reflecting material 31 is 80% or more for deep ultraviolet rays with a wavelength of 200 to 300 nm, which can increase the sterilization efficiency in a limited space and is advantageous for increasing the ultraviolet irradiation dose DL in a single pass.

[0062] Furthermore, since the filter 6 has an initial pressure loss of 1.0 Pa or less when the air volume is at a wind speed of 5.3 cm / sec, the output of the blower fan 11 can be small, which is advantageous for reducing the size of the blower fan 11 and, ultimately, the size of the inactivation sterilization apparatus 1. Furthermore, the filter 6 is a filtering material made of electrostatically charged nonwoven fabric in which microfibers are made to hold static electricity, and therefore can achieve high collection efficiency with low airflow resistance.

[0063] Furthermore, the device is provided with a fixing frame 7 for fixing the filter 6 to the side of the housing 2, and a control unit 43 for turning off the ultraviolet irradiation light source 13 when the fixing frame 7 is removed from the housing 2, thereby preventing the ultraviolet irradiation light source 13 from turning on when the filter is removed. The filter 6 is also provided with a plurality of fixing frames 7A, 7B, and 7C that respectively fix the filter 6 to a plurality of side surfaces of the housing 2, and includes a fixing prohibition structure 51 that prohibits fixing of other fixing frames 7B to the housing 2 when a predetermined fixing frame 7A, 7C among the plurality of fixing frames 7A, 7B, and 7C is not fixed to the housing 2. With this configuration, fixing frame 7B cannot be fixed unless fixing frames 7A and 7C are fixed, and the fixing order of fixing frames 7A, 7B, and 7C can be regulated. In this embodiment, when fixing frame 7B, which is fixed last, is detached, control unit 43 turns off ultraviolet irradiation light source 13, so that ultraviolet irradiation light source 13 can be prevented from being turned on unless all of fixing frames 7A, 7B, and 7C are fixed.

[0064] Furthermore, the air intake 3 that draws air into the housing 2 is positioned at a height of 150 mm or more from the bottom of the housing 2, which prioritizes the intake of air at a higher position than the air around the bottom of the inactivation sterilization device 1, making it easier to efficiently circulate air in the space where the inactivation sterilization device 1 is installed. It also makes it possible to prevent a decrease in device performance due to the intake of dust and other particles that have accumulated on the floor. This is advantageous in reducing the risk of infection with viruses such as the new coronavirus and influenza.

[0065] Furthermore, since the objects that can be inactivated and / or sterilized contain coronaviruses with a protein concentration of 0.1 wt% to 1.0 wt%, it is effective in reducing the risk of coronavirus infection. Furthermore, since the objects that can be inactivated and / or sterilized contain influenza viruses with a protein concentration of 0.1 wt% to 1.0 wt%, it is effective in reducing the risk of influenza virus infection.

[0066] The above embodiment is merely an example of one aspect of the present invention, and can be modified and applied as desired without departing from the spirit of the present invention. For example, the shape and structure of each part of the inactivation and sterilization apparatus 1 may be modified as appropriate, and the inactivation and sterilization apparatus 1 may be modified to a configuration that allows it to be installed on a wall or ceiling.

[0067] The above embodiment supports the following configurations.

[0068] (Configuration 1) An inactivation and sterilization device that irradiates ultraviolet light onto intake air drawn into the device to inactivate and / or sterilize objects contained in the intake air, the device comprising: a filter that filters the intake air with a ventilation resistance that can realize the intake air; an ultraviolet light irradiation light source that irradiates the ultraviolet light onto the intake air filtered by the filter; and a maximum air volume of 9.0 m3 of the intake air after ultraviolet light irradiation. 3 An inactivation sterilization device comprising a blower fan that exhausts air at a rate of 1 / min or more, and a housing that houses the ultraviolet irradiation light source and the blower fan. This configuration provides an inactivation and sterilization device that has a large air volume and is suitable for inactivating and / or sterilizing objects contained in intake air.

[0069] (Configuration 2) The inactivation sterilization device according to Configuration 1, further comprising a housing structure disposed inside the housing and housing the ultraviolet irradiation light source. This configuration can prevent ultraviolet light from leaking into the surroundings of the inactivation sterilization device.

[0070] (Configuration 3) The ultraviolet irradiation dose inside the storage structure is 4.0 mJ / cm 2 The inactivation and sterilization device according to configuration 2, which inactivates and / or sterilizes the object in an environment with a relative humidity of 20% or more and 70% or less. This configuration allows for effective inactivation and / or sterilization of objects over a wide humidity range.

[0071] (Configuration 4) The inactivation sterilization device according to Configuration 2 or 3, wherein an ultraviolet reflective material that reflects the ultraviolet rays is detachably fixed to the inner surface of the storage structure. This configuration makes it easy to perform maintenance such as replacing the ultraviolet reflective material.

[0072] (Configuration 5) The inactivation sterilization apparatus according to Configuration 4, wherein the reflectance of the ultraviolet reflective material is a total reflectance of 80% or more for deep ultraviolet light having a wavelength of 200 to 300 nm. This configuration can increase the sterilization efficiency in a limited space, and is advantageous for increasing the amount of ultraviolet radiation irradiated in a single pass.

[0073] (Configuration 6) The inactivation sterilization apparatus according to any one of Configurations 1 to 5, wherein the filter has an initial pressure loss of 1.0 Pa or less under the condition of an air velocity of 5.3 cm / sec. This configuration requires a small output from the blower fan, which is advantageous for reducing the size of the blower fan and, in turn, the size of the inactivation sterilization device.

[0074] (Configuration 7) The inactivation sterilization apparatus according to Configuration 6, wherein the filter is a filtering medium made of an electrically charged nonwoven fabric in which static electricity is maintained in microfibers. This configuration makes it possible to achieve high collection efficiency with low airflow resistance.

[0075] (Configuration 8) An inactivation sterilization device according to any one of configurations 1 to 7, comprising a fixing frame that fixes the filter to the side of the housing, and a control unit that turns off the ultraviolet irradiation light source when the fixing frame is removed from the housing. This configuration can prevent the ultraviolet light source from turning on when the filter is removed.

[0076] (Configuration 9) An inactivation sterilization device according to any one of configurations 1 to 8, which is provided with a plurality of fixing frames for fixing the filter to each of a plurality of side surfaces of the housing, and which has a fixing prohibition structure that prohibits fixing of other fixing frames to the housing when a predetermined fixing frame among the plurality of fixing frames is not fixed to the housing. According to this configuration, it is not possible to fix other fixed frames unless a predetermined fixed frame is fixed, and the order in which fixed frames are fixed can be regulated.

[0077] (Configuration 10) The inactivation sterilization apparatus according to any one of Configurations 1 to 9, wherein the intake port for drawing air into the housing is located at a height of 150 mm or more from the bottom surface of the housing. This configuration prioritizes the intake of air at a higher position than the air around the bottom of the inactivation sterilization device, making it easier to efficiently circulate air in the space where the inactivation sterilization device is installed, and also makes it possible to prevent a decrease in device performance due to the intake of dust and other particles that have accumulated on the floor, which is advantageous in reducing the risk of viral infection.

[0078] (Configuration 11) The inactivation and sterilization apparatus according to any one of Configurations 1 to 10, wherein the object to be inactivated and / or sterilized contains coronavirus with a protein concentration of 0.1 wt% to 1.0 wt%. This configuration is effective in reducing the risk of coronavirus infection.

[0079] (Configuration 12) The inactivation and sterilization apparatus according to any one of claims 1 to 10, wherein the object to be inactivated and / or sterilized contains influenza viruses having a protein concentration of 0.1 wt% to 1.0 wt%. This configuration is effective in reducing the risk of influenza virus infection. [Explanation of symbols]

[0080] 1 Inactivation sterilizer 2. Case 2S gap 2T recess 2k Positioning part 2m groove 3 Air intake 4 Air outlet 5 Gripping part 6 Filters 7,7A~7C Fixed frame 11 Blower fan 12 Internal light body 12S Gap 13 Ultraviolet irradiation light source 14 Duct 31 UV reflective material 41 Limit Switch 42 Protrusion 43 Control Unit 51 Fixed prohibition structure CT center axis DL UV irradiation amount H Height W intake

Claims

1. An inactivation and sterilization device that irradiates ultraviolet light onto intake air drawn into the device to inactivate and / or sterilize objects contained in the intake air, a filter that filters the intake air with a ventilation resistance that can realize the intake air; an ultraviolet irradiation light source that irradiates the ultraviolet light onto the intake air filtered by the filter; The maximum intake air volume after UV irradiation is 9.0 m ３ a blower fan that exhausts air at a rate of 1 / min or more; a housing that houses the ultraviolet irradiation light source and the blower fan; An inactivation sterilization device comprising:

2. a housing structure for housing the ultraviolet irradiation light source, the housing being disposed inside the housing; The inactivation sterilization apparatus according to claim 1.

3. The ultraviolet irradiation dose inside the storage structure is 4.0 mJ / cm ２ or more, and the object is inactivated and / or sterilized in a humidity environment of 20% or more and 70% or less relative humidity. The inactivation sterilization apparatus according to claim 2.

4. An ultraviolet reflective material that reflects the ultraviolet rays is detachably fixed to the inner surface of the storage structure. The inactivation sterilization apparatus according to claim 2.

5. The reflectance of the ultraviolet reflector is 80% or more for deep ultraviolet rays with a wavelength of 200 to 300 nm. The inactivation sterilization apparatus according to claim 4.

6. The filter has an initial pressure loss of 1.0 Pa or less under the condition of an air velocity of 5.3 cm / sec. The inactivation sterilization apparatus according to any one of claims 1 to 5.

7. The filter is a filtering material made of electrostatically charged nonwoven fabric made of microfibers. The inactivation sterilization apparatus according to claim 6.

8. a fixing frame for fixing the filter to a side surface of the housing; a control unit that turns off the ultraviolet irradiation light source when the fixing frame is removed from the housing; The inactivation sterilization apparatus according to any one of claims 1 to 5.

9. a plurality of fixing frames for fixing the filter to a plurality of side surfaces of the housing, A fixing prohibition structure is provided that prohibits fixing of other fixing frames to the housing when a predetermined fixing frame among the plurality of fixing frames is not fixed to the housing. The inactivation sterilization apparatus according to any one of claims 1 to 5.

10. The air intake port for drawing air into the housing is located at a height of 150 mm or more from the bottom surface of the housing. The inactivation sterilization apparatus according to any one of claims 1 to 5.

11. 6. The inactivation and sterilization apparatus according to claim 1, wherein the object to be inactivated and / or sterilized contains coronavirus having a protein concentration of 0.1 wt % to 1.0 wt %.

12. 6. The inactivation and sterilization apparatus according to claim 1, wherein the object to be inactivated and / or sterilized contains influenza viruses having a protein concentration of 0.1 wt % to 1.0 wt %.

Images