Purification device, purification system

Abstract

To provide a purification device and purification system that can achieve an extremely high purification effect compared to conventional methods. [Solution] The device comprises a flow path having an intake port and an outlet, through which a fluid taken in from the intake port flows, a first photocatalytic material containing zirconia nanoparticles arranged in the flow path, and a light source that irradiates the first photocatalytic material with ultraviolet light belonging to the wavelength band of 190 nm to less than 240 nm.

Description

[Technical Field]

[0001] This invention relates to a purification device and a purification system. [Background technology]

[0002] Conventionally, techniques for inactivating bacteria and viruses (hereinafter collectively referred to as "bacteria, etc.") by irradiating them with ultraviolet light have been known. In recent years, ultraviolet light with a wavelength of less than 240 nm has been particularly attracting attention because it is easily absorbed by the surface of human skin (e.g., the stratum corneum) and does not easily penetrate into the skin. Therefore, methods and devices for inactivating bacteria and viruses in a space using ultraviolet light in this wavelength range have attracted particular attention.

[0003] Furthermore, there is a known technique for decomposing and removing organic compounds in gases using a photocatalyst that is activated by irradiation with ultraviolet light (see Patent Document 1 below). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Special Publication No. 2021-511161 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] In light of the recent COVID-19 pandemic, the inventors have been diligently researching inactivation technology for bacteria and other microorganisms by irradiation with ultraviolet light, as well as purification technology using photocatalysts that are activated by irradiation with ultraviolet light. In this specification, "purification" is used to mean the sterilization / inactivation of bacteria and viruses, and the decomposition and removal of organic matter in general, as well as substances that are harmful to the human body or that cause unpleasant odors (hereinafter, the substances to be treated are collectively referred to as "specific substances").

[0006] In air purification, there is a demand for equipment and systems that can rapidly process specific substances and sufficiently reduce bacteria and other specific substances present in the air. Therefore, there is a constant need for purification devices and systems with superior characteristics.

[0007] In view of the above problems, the present invention aims to provide a purification device and a purification system that can achieve an extremely high purification effect compared to conventional devices. [Means for solving the problem]

[0008] The present invention's purification device is It has an inlet and an outlet, and a flow path through which fluid taken in from the inlet flows, A first photocatalytic material containing zirconia nanoparticles is placed in the aforementioned channel, The invention is characterized by comprising a light source that irradiates the first photocatalytic material with ultraviolet light belonging to a wavelength band of 190 nm or more and less than 240 nm.

[0009] In this specification, "zirconia nanoparticles" refers to particles made of zirconia (ZrO2) with a primary particle size on the order of nanometers (less than 1 μm). Here, the method for measuring the particle size is based on the "transmission electron microscopy" method described in JIS Z 8901:2006, Annex (Normative), Method for Measuring the Average Particle Diameter of Test Particles 1.

[0010] Furthermore, in this specification, the term "fluid" is used collectively to refer to both gases and liquids. More specifically, as mentioned above, the phrase "a flow path through which a fluid flows" is intended to include both flow paths through which gases and flow paths through which liquids.

[0011] The inventors, through various experiments related to purification treatment, discovered that irradiating a photocatalytic material containing zirconia nanoparticles with ultraviolet light belonging to the wavelength range of 190 nm to less than 240 nm exhibits a high reaction with organic compounds. Details of this will be described later in the section on "Modes for Carrying Out the Invention," along with the contents of the verification experiments.

[0012] Furthermore, as mentioned above, the above-mentioned purification device can also be used when the "fluid" is a liquid. For example, by connecting the intake and outlet ports to a pipe through which the liquid to be treated flows, the liquid can be purified.

[0013] The first photocatalytic material, placed within the flow channel and activated by ultraviolet light irradiation, can purify not only the gas flowing into the channel but also the liquid flowing into the channel. This is because, similar to how the activated first photocatalytic material decomposes and removes specific substances contained in gases upon contact, it can also decompose and remove specific substances contained in liquids upon contact.

[0014] In recent years, attention has been focused on perfluoroalkyl and polyfluoroalkyl compounds (PFAS: perfluoroalkyl compounds and polyfluoroalkyl compounds) as harmful substances contained in tap water that are heat-resistant and difficult to remove. The water purification device of the present invention is intended to be applied to remove such harmful substances contained in tap water, and is also expected to have a high purification capacity.

[0015] In the above-mentioned purification device, The device may be equipped with a support, and the first photocatalytic material may be fixed to the support by being fixed with a fixing material.

[0016] Furthermore, in the above-mentioned purification device, The aforementioned adhesive may have an inorganic main component.

[0017] The fixing material can be any material as long as it can fix the first photocatalyst material as a binder. For example, the main component may be an organic material (organic binder) such as a sulfonic acid group-containing fluorine-based ion exchange resin or other resins, or the main component may be an inorganic material (inorganic binder) such as silicate. The inorganic material is a material that is relatively resistant to ultraviolet light with a wavelength of 190 nm or more and 240 nm or less, and is a material that is relatively difficult to absorb the ultraviolet light. And the inorganic material is a material that can fix the zirconia nanoparticles to the member by being cured after coating, and can be said to be a very excellent material as the fixing material employed in the purification device. In this specification, the "main component" is used with the intention of referring to the material with the highest content rate.

[0018] Also, in the above purification device, The purification device according to claim 2, wherein the support is mainly composed of an inorganic material.

[0019] Furthermore, in the above purification device, The first photocatalyst material may be supported on the support composed of glass fibers, and thus may be supported by the support.

[0020] Furthermore, the above purification device In the flow path, a filter may be provided to prevent the first photocatalyst material disposed on the discharge port side as viewed from the support from being discharged to the outside of the flow path.

[0021] Also, by disposing a filter on the discharge port side as viewed from the support to prevent the first photocatalyst material from being discharged to the outside of the flow path, the first photocatalyst material is prevented from being separated from the support and discharged to the outside of the flow path. The filter is mainly provided to suppress the discharge of the first photocatalyst material to the outside of the flow path, but it is also expected to have a function of capturing substances and objects other than the first photocatalyst material such as specific substances that could not be completely processed.

[0022] Also, in the above purification device, The support has a specific surface area of ​​1 m². 2 It is acceptable if it is greater than or equal to / g.

[0023] The specific surface area of ​​the support is 1 m² 2 A value of 1 / g or higher increases the amount of specific substances that the support can adsorb, and also facilitates close proximity and contact between the specific substance and the first photocatalytic material on the surface of the support. In other words, with the above configuration, the purification device obtains both the decomposition effect of the first photocatalytic material alone and the adsorption effect of the support, thus further increasing the efficiency of purification.

[0024] The above-mentioned purification device is The system is configured to take gas into the flow path from the intake port, and may also include an ozone filter positioned on the outlet side of the region in the flow path that is irradiated with ultraviolet light.

[0025] In the above-mentioned purification device, The ultraviolet light emitted from the light source may be light belonging to the wavelength band of 200 nm or more and less than 240 nm.

[0026] According to the above configuration, the generation of ozone caused by ultraviolet light irradiating oxygen present in the flow path or between the flow path and the light source can be suppressed.

[0027] Furthermore, ozone is produced when oxygen molecules are irradiated with ultraviolet light, and it is known that ultraviolet light with a wavelength of less than 200 nm produces more ozone than ultraviolet light with a wavelength of 200 nm or more. Therefore, by making the ultraviolet light emitted from the light source fall within the above wavelength range, the generation of ozone in the flow channel can be suppressed.

[0028] The above-mentioned purification device is The flow path may also be equipped with an adsorbent that adsorbs specific substances contained in the fluid.

[0029] Furthermore, the above-mentioned purification device is The second photocatalytic material may be positioned on the outlet side of the adsorbent material within the flow path.

[0030] The second photocatalytic material is primarily installed to decompose specific substances that have detached from the adsorbent. The second photocatalytic material is envisioned to be made of a different material than the first photocatalytic material, and the light used to activate it may differ from the light used to activate the first photocatalytic material. Specifically, as an example, the first photocatalytic material may contain zirconia nanoparticles, while the second photocatalytic material may contain titania (TiO2). Furthermore, the first photocatalytic material may be irradiated with ultraviolet light emitted from the aforementioned light source, while the second photocatalytic material may be irradiated with light emitted from a different light source. Alternatively, instead of providing a second photocatalytic material, the first photocatalytic material may be installed at multiple locations within the flow path to achieve the same effect as the second photocatalytic material.

[0031] The present invention's purification system is It is a system for purifying space, An object to be irradiated, to which a first photocatalytic material containing zirconia nanoparticles is attached, is placed within the aforementioned space. The system is characterized by comprising a light source that irradiates the object to be irradiated with ultraviolet light belonging to the wavelength band of 190 nm to less than 240 nm.

[0032] The above purification system is The light source and the object to be illuminated may be arranged within a partitioned space.

[0033] In the above purification system, The device may be equipped with a support, and the first photocatalytic material may be fixed to the support by being fixed with a fixing material.

[0034] Furthermore, in the above purification system, The aforementioned binder may be an inorganic binder.

[0035] Furthermore, in the above purification system, The support may be a member exhibiting any of the following shapes: sheet-like, plate-like, mesh-like, or uneven.

[0036] Furthermore, in the above purification system, The support may be a component installed on the ceiling, wall, or floor of a partitioned space.

[0037] In the above purification system, The ultraviolet light emitted from the light source may be light belonging to the wavelength band of 200 nm or more and less than 240 nm.

[0038] The above purification system is An adsorbent that adsorbs specific substances contained in the air within the space may be placed within the space.

[0039] Furthermore, in the above purification system, The support has a specific surface area of ​​1 m². 2 It is acceptable if it is greater than or equal to / g.

[0040] Furthermore, the products covered by this invention do not cause erythema or keratitis on the skin or eyes of humans or animals, and can provide the inherent germicidal and virus inactivation capabilities of ultraviolet light. In particular, unlike conventional light source devices, it can be used in occupied environments, and by installing it in occupied indoor or outdoor environments, the entire environment can be irradiated, providing virus suppression and sterilization of the air and the surfaces of installed components within the environment.

[0041] This aligns with Goal 3 of the United Nations-led Sustainable Development Goals (SDGs), "Ensure healthy lives and promote well-being for all at all ages," and makes a significant contribution to Target 3.3, "By 2030, eradicate AIDS, tuberculosis, malaria and neglected tropical diseases, and combat hepatitis, waterborne diseases and other infectious diseases." [Effects of the Invention]

[0042] According to the above configuration, a purification device and purification system can be realized that can achieve an extremely high purification effect compared to conventional methods. [Brief explanation of the drawing]

[0043] [Figure 1] This is a schematic diagram illustrating the configuration of one embodiment of a purification system. [Figure 2] This is a schematic perspective view showing the configuration of the light source device. [Figure 3] Figure 2 is a diagram showing the light source device as viewed from the light emission section. [Figure 4A] This graph shows the time-dependent change in formaldehyde concentration for samples using zirconia nanoparticles and TiO2 as the primary photocatalytic material in the verification experiment. [Figure 4B] This bar graph shows the reaction rate multiplier for each sample in the verification experiment. [Figure 5] This is a schematic diagram showing the configuration of one embodiment of a purification device. [Figure 6] Figure 5 is a cross-sectional view of the purification device as seen from the discharge side. [Figure 7] This is a schematic diagram showing the configuration of one embodiment of a purification device. [Figure 8] This is a schematic diagram showing the configuration of one embodiment of a purification device. [Modes for carrying out the invention]

[0044] The purification device and purification system of the present invention will be described below with reference to the drawings. Note that the following drawings are schematic illustrations, and the dimensional ratios and numbers shown in the drawings do not necessarily correspond to the actual dimensional ratios and numbers.

[0045] [Purification System] First, one embodiment of the purification system of the present invention will be described.

[0046] Figure 1 is a schematic diagram showing the configuration of one embodiment of the purification system 1. As shown in Figure 1, the purification system 1 is configured such that ultraviolet light L1 emitted from a light source device 10 is directly irradiated onto a sheet material 3, which is the object to be irradiated, and an adsorption sheet 4, within a space 2 where human traffic is expected, with the sheet material 3 being the object to be irradiated and an adsorption sheet 4 installed on the wall surface 2b.

[0047] As shown in Figure 1, the purification system 1 is a system that irradiates ultraviolet light L1 emitted from a light source device 10 into a space 2 where human traffic is expected, on which a sheet material 3 is installed on the wall surface 2b. Note that the sheet material 3 may be installed on the ceiling 2a, floor surface 2c, or on an item (e.g., a table) installed within space 2, rather than on the wall surface 2b of space 2. Also, the light source device 10 may be installed on the wall surface 2b, floor surface 2c, or on an item (e.g., a table) installed within space 2, rather than on the ceiling 2a of space 2.

[0048] Figure 2 is a schematic perspective view showing the configuration of the light source device 10, and Figure 3 is a view of the light source device 10 of Figure 2 as seen toward the light emission unit 12. As shown in Figure 2, the light source device 10 comprises a housing 11 and a light emission unit 12 provided on any one side of the housing 11. As shown in Figure 3, the light source device 10 has an excimer lamp 13 that emits ultraviolet light with a peak wavelength of 222 nm mounted inside the housing 11.

[0049] The light emission section 12 is a window section mounted on the main surface of a quartz glass plate, which maintains the light intensity of any ultraviolet light belonging to the wavelength band of 200 nm to 235 nm among the ultraviolet light emitted from the ultraviolet light source at 40% or more, and suppresses the integral value of the light intensity of ultraviolet light belonging to the UV-C band with a wavelength of 240 nm or more to 3% or less compared to the integral value of the light intensity of ultraviolet light belonging to the wavelength band of 200 nm to 235 nm. The optical filter may also be an optical filter that suppresses the integral value of the light intensity of ultraviolet light belonging to the UV-C band with a wavelength of 235 nm or more to 3% or less compared to the integral value of the light intensity of ultraviolet light belonging to the wavelength band of 200 nm to 235 nm. Here, "UV-C band with a wavelength of 240 nm or more" refers to the wavelength band of 240 nm to 280 nm. The rate of change in light intensity here is determined using ultraviolet light incident at an incident angle of 0° to the incident surface of the optical filter as a reference.

[0050] From the light emission unit 12, the light emitted from the excimer lamp 13 that has passed through the optical filter is radiated outwards from the housing 11 as ultraviolet light L1.

[0051] As shown in Figure 3, the excimer lamp 13 is an ultraviolet light source comprising a discharge tube 13a extending in one direction, and a pair of electrodes (13b, 13b) spaced apart in the direction of the discharge tube 13a, on which the discharge tube 13a is mounted and which supplies power to the discharge tube 13a. In the first embodiment, the excimer lamp 13 is provided with multiple discharge tubes 13a as shown in Figure 3, but the number of discharge tubes 13a may be just one.

[0052] The discharge tube 13a is sealed with krypton (Kr) gas and chlorine (Cl) gas as light-emitting gases inside, and is configured to emit ultraviolet light with a peak wavelength of 222 nm when an AC voltage or pulse voltage is applied between a pair of electrodes (13b, 13b).

[0053] The ultraviolet light source mounted on the light source device 10 may be an excimer lamp in which krypton (Kr) gas and bromine (Br) gas are sealed inside the discharge tube 13a, and when an AC voltage or pulse voltage is applied between a pair of electrodes (13b, 13b), it emits ultraviolet light with a peak wavelength of 207 nm. Alternatively, the ultraviolet light source may be any light source capable of emitting ultraviolet light with a peak wavelength in the range of 200 nm to 235 nm, and is not limited to an excimer lamp; it may also be an LED, a laser light source, or a light source equipped with a UVC phosphor or wavelength conversion element.

[0054] A first photocatalytic material containing zirconia nanoparticles is fixed to the surface of sheet material 3.

[0055] The sheet material 3 can be any material to which the first photocatalytic material can be fixed, such as cardboard, paintings, cloth, wallpaper, or mats. Furthermore, it does not have to be a sheet-like material, but can be a plate-like, mesh-like, or uneven material. However, if the sheet material 3 is made of an organic material, it is desirable to increase its resistance to ultraviolet light by coating the surface with an inorganic material. In addition, the sheet material 3 has a specific surface area of ​​1 m². 2 It is preferable to use a component with a concentration of 1 / g or more. Specifically, by fixing the first photocatalytic material to the adsorption sheet 4 described later, in addition to the cleaning effect of the first photocatalytic material, an auxiliary effect of promoting cleaning can be obtained by adsorbing the specific substance to be treated. Furthermore, the fixing material for fixing the first photocatalytic material may be any material to which the first photocatalytic material can be fixed, but it is preferable that the main component is an inorganic material with relatively high resistance to ultraviolet light.

[0056] Here, a suitable specific material for the sheet material 3 is, for example, coated paper.

[0057] Furthermore, the arrangement method of the sheet material 3 is arbitrary; for example, it may be attached to the inner wall surface of space 2, or it may be suspended at any position within space 2 by a dedicated gripping member provided on the ceiling 2a. Moreover, the sheet material 3 does not have to be in the form of a sheet and may be of any shape, however, considering the ease of installation within space 2, it is preferable that it be in the form of a sheet or a plate.

[0058] In this embodiment, the suction sheet 4 is attached to the wall surface 2b of space 2 and has a specific surface area of ​​2m². 2 It is a sheet-like component with a density of / g. The adsorption sheet 4 is an adsorbent that is installed as an auxiliary material to promote purification by adsorbing specific substances to be treated, in addition to the purification effect of the first photocatalytic material.

[0059] The form and size of the adsorption sheet 4 are not particularly limited and may be wallpaper attached to the wall surface 2b or a mat laid on the floor surface 2c. However, in order to enhance the cleaning effect of the adsorption sheet 4, it is important that it can sufficiently adsorb specific substances, and the specific surface area is 1 m². 2 It is preferable that the amount is 1 / g or more. However, if the space 2 can be sufficiently purified by the purification effect of the first photocatalytic material alone, the adsorption sheet 4 does not need to be installed.

[0060] [Verification experiment] Here, we will explain in detail the verification experiment conducted to confirm the effectiveness of the purification treatment in this embodiment.

[0061] In an experimental box containing formaldehyde, a light source was turned on to a sheet material to which a photocatalytic material was fixed under various conditions. The change in formaldehyde concentration in the experimental box over time was then measured. The comparison method involved measuring the rate of change in formaldehyde concentration in the experimental box after lighting (reaction rate constant [min]). -1 The following were compared. A container with a volume of 45L was used as the experimental box.

[0062] (Examples) As the support, a member was adopted in which zirconia nanoparticles with a primary particle size of 10 nm or less (using the zirconia dispersion liquid "Zirconeo-Cw" manufactured by Aitec Co., Ltd.) as a photocatalyst material were fixed on a glass plate with a length of 260 mm and a width of 150 mm. The light irradiated on the irradiation object is the light emitted from an excimer lamp in which krypton (Kr) gas and chlorine (Cl) gas are enclosed in the light-emitting gas, and is obtained by passing through an optical filter that does not substantially transmit ultraviolet light belonging to the longer wavelength side than 240 nm, and has a peak wavelength of 222 nm and an illuminance of 21 μW / cm 2 of ultraviolet light.

[0063] (Comparative Example 1) The light irradiated on the sheet material is the same as in the example except that it is ultraviolet light with a peak wavelength of 254 nm and an illuminance of 41 μW / cm 2 emitted from a mercury lamp.

[0064] (Comparative Example 2) The light irradiated on the sheet material is the same as in the example except that it is ultraviolet light with a peak wavelength of 450 nm and an illuminance of 2370 Lx emitted from an LED.

[0065] (Comparative Example 3) It is the same as in the example except that the sheet material is not irradiated with ultraviolet light.

[0066] (Comparative Example 4) It is the same as in the example except that the photocatalyst material is not arranged.

[0067] (Comparative Example 5) It is the same as in the example except that the photocatalyst material is zirconia particles with a primary particle size of about 1 μm to 10 μm.

[0068] (Comparative Example 6) It is the same as in the example except that the photocatalyst material is titania nanoparticles with a primary particle size of about 3 nm to 5 nm.

[0069] The reaction rate constant was calculated by drawing an approximate straight line on a plot of the change in formaldehyde concentration every minute from the time of ignition until the decrease in formaldehyde concentration slowed down, and then measuring the slope of that line. Immediately after ignition, a steep decrease in concentration was observed due to the adsorption of formaldehyde onto some material inside the experimental box, combined with the normal cleaning process. However, the effect of adsorption disappeared very quickly. Therefore, as described above, the reaction rate constant was calculated from the time of the steep decrease in concentration until the decrease in formaldehyde concentration slowed down.

[0070] [result] Figure 4A is a graph showing the time change in formaldehyde concentration for samples using zirconia nanoparticles and titania nanoparticles as the primary photocatalyst in the verification experiment, and Figure 4B is a bar graph showing the reaction rate multiplier for each sample in the verification experiment. First, as shown in Figure 4A, it can be seen that the decrease in formaldehyde concentration is more significant in the sample using zirconia nanoparticles as the primary photocatalyst than in the sample using titania particles as the primary photocatalyst.

[0071] As shown in Figure 4B, the reaction rate constant of the example was more than 10 times higher than that of each comparative example. In other words, it was confirmed that an extremely high purification effect can be obtained by using zirconia nanoparticles as a photocatalyst and irradiating them with short-wavelength ultraviolet light with a wavelength band of 190 nm to less than 240 nm as the ultraviolet light to activate the zirconia nanoparticles.

[0072] The inventors had expected that irradiating the zirconia nanoparticles used as a photocatalytic material with ultraviolet light having an energy greater than the band gap energy of zirconia would yield some degree of purification effect. However, the fact that the effect was more than 10 times greater than when other photocatalytic materials were used or when longer wavelength ultraviolet light was utilized far exceeded their expectations.

[0073] Based on the above, this verification experiment confirmed that by using zirconia nanoparticles as a photocatalytic material and irradiating them with ultraviolet light having an energy greater than the band gap energy of zirconia, an extremely high purification effect can be obtained.

[0074] Furthermore, according to the Arrhenius plot, which shows the ease of reaction with respect to thermal energy, it is generally known that the reaction rate increases exponentially as the input thermal energy increases. It is presumed that a similar trend will occur with light energy. Therefore, it is thought that the reaction rate will increase exponentially with light of wavelengths of 190-240 nm, where the photon energy is 5.17 eV or higher, compared with light of wavelength 370 nm, where the photon energy is 3.36 eV.

[0075] Furthermore, it is thought that the difference in oxidizing power due to the respective band gap energies (zirconia 5.0 eV, titania 3.2 eV) also affects the reaction rate. Moreover, zirconia, with its relatively large band gap energy, can cleave C-Cl bonds with a bond energy of about 3.5 eV, and can even cleave CF bonds with bond energies of about 3.6 eV to 5.5 eV, which conventional photocatalysts cannot cleave.

[0076] Furthermore, with photocatalysts, the smaller the particle size, the larger the specific surface area of ​​the particle, which in turn speeds up the reaction rate of chemical reactions and adsorption with specific substances.

[0077] Therefore, it is presumed that the above results are due to the synergistic effect of differences in photon energy and oxidizing power, as well as the ability to cleave CF bonds that conventional photocatalysts could not, and the fact that the photocatalytic material is made of nanoparticles. In other words, in this verification experiment, an extremely high purification effect was confirmed in the example using ultraviolet light with a peak wavelength of 222 nm, but it can be inferred that if the ultraviolet light is 248 nm or less, results almost equivalent to those in the above example can be expected.

[0078] Conversely, if ultraviolet light with an extremely short wavelength is used, it is easily absorbed by oxygen molecules and does not easily travel through the air, which presents a challenge. In particular, ultraviolet light with a wavelength of less than 190 nm can only travel a few centimeters through the air, which may make it difficult to irradiate the photocatalytic material at all.

[0079] Furthermore, short-wavelength ultraviolet light is absorbed by oxygen molecules, generating oxygen radicals. These oxygen radicals then react with oxygen molecules in the air to produce ozone. While ultraviolet light at the intensity used for air purification is unlikely to generate high concentrations of ozone, if there is concern about the generation of even small amounts of ozone, the wavelength of ultraviolet light L1 may be set to 200 nm or higher, which relatively suppresses ozone generation. Additionally, ozone filters or adsorbents may be installed around the light source device 10 to adsorb ozone.

[0080] Based on the above, it can be said that the purification system 1 exhibits a particularly remarkable effect compared to conventional purification systems that combine ultraviolet light and photocatalytic materials, and can demonstrate a high level of purification. Furthermore, the purification system 1, which can demonstrate such an extremely high level of purification, can be applied and used in living spaces, corridors, factories and other facilities where people are expected to come and go, as well as inside vehicles. However, it can also be fully utilized to purify designated spaces not only in partitioned spaces like space 2, but also in outdoor spaces such as roads adjacent to factories, public restrooms, and train station platforms. Naturally, the purification system 1 can also be applied to spaces where people are not expected to come and go.

[0081] [Purification device] Next, embodiments of the purification device of the present invention will be described.

[0082] Figure 5 is a schematic diagram showing the configuration of one embodiment of the purification device 20, and Figure 6 is a cross-sectional view of the purification device of Figure 5 as seen from the outlet side. As shown in Figures 5 and 6, the purification device 20 comprises a housing 21, a light source 22, a support 23, a blower fan 24, a filter 25, and an adsorbent 26. Figure 5 schematically shows the housing 21 with one side removed so that the internal structure can be seen. In Figure 6, the blower fan 24 is shown with a dashed line so that the position of the blower fan 24 located beyond the air filter 23a can be seen.

[0083] As shown in Figure 5, the housing 21 has an intake port 21a and an outlet port 21b, and a flow path is formed inside through which the fluid W1 taken in from the intake port 21a flows toward the outlet port 21b. Inside the flow path formed inside the housing 21, a light source 22, a support 23, a blower fan 24, a filter 25, and an adsorbent 26 are arranged. In this embodiment, the fluid W1 is the air in the space in which the purification device 20 is installed.

[0084] The light source 22 of this embodiment, although differing in external shape and size, is a device with the same configuration as the light source device 10 described above, and is configured to emit ultraviolet light L1 with a peak wavelength of 222 nm, with an excimer lamp (not shown) mounted inside. The light source 22 is fixed to the side of the housing 21 such that the light emitting part 22a faces the support 23, so that the ultraviolet light L1 is irradiated onto the support 23, which is supported by the support 23. The light source 22 may employ an excimer lamp that emits ultraviolet light with a different peak wavelength, similar to the light source device 10 of the purification system 1, or it may employ other light sources such as LEDs.

[0085] Furthermore, for the same reasons as explained in the purification system 1, it is preferable that the ultraviolet light L1 emitted by the light source 22 of this embodiment is light belonging to a wavelength band of 200 nm or more and less than 240 nm.

[0086] Furthermore, the light-emitting section 22a of the light source 22 may be equipped with an optical filter that, similar to the light source device 10 described above, maintains the light intensity of ultraviolet light belonging to the wavelength band of 200 nm to 235 nm among the ultraviolet light emitted from the ultraviolet light source at 40% or more, and suppresses the integrated value of the light intensity of ultraviolet light belonging to the UV-C band with a wavelength of 240 nm or more to 3% or less of the integrated value of the light intensity of ultraviolet light belonging to the wavelength band of 200 nm to 235 nm. However, whether or not to equip the optical filter is optional.

[0087] The support 23 of this embodiment is a mesh-like member made of glass fibers that are relatively resistant to ultraviolet light L1, fixed by a frame made of stainless steel, and supports a photocatalytic material containing zirconia nanoparticles. The photocatalytic material of this embodiment is activated by irradiation with ultraviolet light L1, similar to the purification system 1, and serves both as a first photocatalytic material for processing specific substances and as a second photocatalytic material for processing specific substances that detach from the adsorbent and head toward the discharge port 21b.

[0088] Furthermore, the first photocatalytic material and the second photocatalytic material referred to here may be provided individually. Also, if no adsorbent is provided, or if the amount of a specific substance detached from the adsorbent is extremely small, it is not necessary to provide a photocatalytic material that functions as a second photocatalytic material. Moreover, by providing the first photocatalytic material in multiple locations, a portion may be used to function as a second photocatalytic material, and the light source that emits light to activate the second photocatalytic material may be a light source other than light source 22. And the light source other than light source 22 is not limited to an ultraviolet light source, but may also be a visible light source, and the type of light source is not limited to lamps or solid light sources.

[0089] The shape and material of the support 23 are arbitrary, but it is preferable that it be a metal, ceramic, fluororesin, or cellulose, which have relatively high resistance to ultraviolet light. The first photocatalytic material may also be fixed to the support 23 using an adhesive. The adhesive can be any material to which the first photocatalytic material can be fixed, but it is preferable that it be a silicate or fluororesin, which have relatively high resistance to ultraviolet light.

[0090] The blower fan 24 is a device that takes in the fluid W1 from the intake port 21a and guides it toward the exhaust port 21b. However, if the cleaning device 20 is configured so that the fluid W1 flows through the housing in a desired direction by natural convection or the like, the blower fan 24 may not be installed.

[0091] Furthermore, the blower fan 24 in this embodiment is a fan equipped with rotating blades as shown in Figure 5, but the configuration is not limited to this. In this embodiment, the support 23 is a member formed in a mesh shape from glass fibers. For this reason, although the blower fan 24 is shown with a dashed line in Figure 6, the cleaning device 20 can be seen even with the blower fan 24 visible through the support 23.

[0092] The filter 25 is positioned within the flow path inside the housing 21 on the side of the outlet 21b of the support 23, preventing the first photocatalytic material detached from the support 23 from being discharged to the outside of the housing 21. The filter 25 only needs to be configured to capture clumps containing the first photocatalytic material that have aggregated to a size of μm or larger by an adsorbent or the like; for example, a urethane filter may be used.

[0093] The adsorbent 26, like the adsorbent sheet 4 of the purification system 1, is an adsorbent that is installed as an auxiliary material to promote purification by adsorbing specific substances to be treated, in addition to the purification effect of the first photocatalytic material. In this embodiment, the adsorbent 26 is attached to the inner wall surface of the housing 21 and has a specific surface area of ​​1 m². 2 It is a plate-shaped member with a weight of / g.

[0094] The form and size of the adsorbent 26 are not particularly limited. However, in order to enhance the cleaning effect of the adsorbent 26, it is important that it can sufficiently adsorb specific substances, and that its specific surface area is 1 m². 2 It is preferable that the amount is 1 / g or more. However, if sufficient purification effect can be obtained with the first photocatalytic material alone, the adsorbent 26 does not need to be installed.

[0095] The purification device 20 with the above configuration is similar to the purification system 1 described above in that it purifies the fluid W1 to be treated by bringing it into contact with a first photocatalytic material containing activated zirconia nanoparticles, which is activated by irradiation with ultraviolet light L1. In other words, it can be seen that the purification device 20 is expected to have the same effect as the purification system 1.

[0096] Based on the above, it can be said that the purification device 20 exhibits a particularly remarkable purification effect compared to conventional purification devices. Furthermore, the purification device 20, which can exhibit such an extremely high purification effect, can be fully utilized not only for purifying partitioned spaces, but also for purifying outdoor spaces such as train station platforms, and designated spaces such as freight containers where human traffic is not expected.

[0097] As mentioned above in the explanation of the verification experiment for the purification system 1, short-wavelength ultraviolet light is absorbed by oxygen molecules, generating oxygen radicals. These oxygen radicals then react with oxygen molecules in the air to produce ozone. Therefore, if ozone generation is a concern, the wavelength of ultraviolet light L1 may be set to 200 nm or more, which relatively suppresses ozone generation, and an ozone filter or adsorbent may be installed inside the housing 21 to adsorb ozone.

[0098] Figures 7 and 8 are schematic diagrams showing the configuration of one embodiment of a purification device different from that shown in Figure 5. In both the purification devices (30, 40) shown in Figures 7 and 8, the fluid to be treated W1 is configured to flow through the inside of a channel (31, 41) made of a material that substantially transmits ultraviolet light L1 emitted from a light source (32, 42).

[0099] A first photocatalytic material (not shown) is placed within the flow channels (31, 41), which is activated by irradiation with ultraviolet light L1, and purifies the fluid W1 that flows into the flow channels (31, 41) from the intake ports (31a, 41a). The purified fluid W1 is then discharged from the outlet ports (31b, 41b). The fluid W1 treated by the purification devices (30, 40) shown in Figures 7 and 8 is a liquid.

[0100] The first photocatalytic material placed within the channels (31, 41) may be a material containing zirconia nanoparticles coated on the inner wall surface of the channels (31, 41), or it may be fixed to a support made of stainless steel material that is cylindrical and has multiple through holes, and then placed within the channels (31, 41).

[0101] In this embodiment, the light sources (32, 42) are assumed to be excimer lamps that emit ultraviolet light L1 including light belonging to the wavelength band of 190 nm to 240 nm, with a configuration similar to that of the excimer lamp described above, but solid light sources such as LEDs can also be used. In this embodiment as well, optical filters as described above may be installed. In this embodiment, the optical filters do not necessarily have to be installed on the light source (32, 42) side, and may, for example, be provided on the wall surface of the flow path (31, 41).

[0102] Furthermore, a filter (not shown) for suppressing the discharge of the first photocatalytic material, as described above, may be installed inside the flow path (31, 41) on the outlet (31b, 41b) side of the position where the first photocatalytic material is placed.

[0103] The configurations of the purification system 1 and purification device 20 described above are merely examples, and the present invention is not limited to the illustrated configurations.

[0104] Furthermore, the purification system 1 may be constructed using the purification device 20. In other words, the purification device of the present invention can also constitute a part of the purification system of the present invention. [Explanation of Symbols]

[0105] 1: Purification System 2 : Space 2a : Ceiling 2b: Wall surface 2c: Floor surface 3: Sheet material 4: Adhesive sheet 10: Light source device 11: Cabinet 12: Light-emitting section 13: Excimer Lamp 13a: Discharge tube 13b : Electrode 20: Purification device 21: Cabinet 21a: Inlet 21b: Outlet 22 : Light source 23: Mounting hardware 23a: Support 24: Fan for ventilation 25: Shatterproof filter 26: Adsorbent 30: Purification device 31: Flow path 31a: Inlet 31b: Outlet 32 : Light source 40: Purification device 41: Flow path 41a: Inlet 41b: Outlet 42 : Light source L1: Ultraviolet light W1: Fluid

Claims

1. It has an inlet and an outlet, and a flow path through which fluid taken in from the inlet flows, A first photocatalytic material containing zirconia nanoparticles is placed in the aforementioned channel, A purification device characterized by comprising a light source that irradiates the first photocatalytic material with ultraviolet light belonging to a wavelength band of 190 nm or more and less than 240 nm.

2. The cleaning device according to claim 1, comprising a support, wherein the first photocatalytic material is fixed to the support by a fixing material.

3. The cleaning device according to claim 2, characterized in that the fixing material has an inorganic material as its main component.

4. The cleaning device according to claim 2, characterized in that the support is mainly composed of an inorganic material.

5. The purification device according to claim 3, characterized in that the first photocatalytic material is supported on the support made of glass fibers.

6. The purification device according to claim 5, further comprising a filter located within the flow path on the outlet side as viewed from the support, for preventing the first photocatalytic material from being discharged to the outside of the flow path.

7. The support has a specific surface area of ​​1 m². 2 The purification device according to claim 2, characterized in that it is 1 / g or more.

8. The purification device according to claim 1, characterized in that it is configured to take gas into the flow path from the intake port and comprises an ozone filter positioned on the outlet side of the region in the flow path that is irradiated with ultraviolet light.

9. The cleaning device according to claim 1, characterized in that the ultraviolet light emitted from the light source belongs to a wavelength band of 200 nm or more and less than 240 nm.

10. The purification device according to claim 1, characterized in that the flow path is provided with an adsorbent that adsorbs a specific substance contained in the fluid.

11. The purification device according to claim 10, characterized in that a second photocatalytic material is arranged on the discharge side of the adsorbent material in the flow path.

12. It is a system for purifying space, An object to be irradiated, to which a first photocatalytic material containing zirconia nanoparticles is attached, is placed within the aforementioned space. A cleaning system characterized by comprising a light source that irradiates the object to be irradiated with ultraviolet light belonging to a wavelength band of 190 nm or more and less than 240 nm.

13. The cleaning system according to claim 12, characterized in that the light source and the object to be irradiated are arranged in a partitioned space.

14. The cleaning system according to claim 12, characterized in that it comprises a support, and the first photocatalytic material is fixed to the support by being fixed with a fixing material.

15. The cleaning system according to claim 14, characterized in that the fixing material has an inorganic material as its main component.

16. The cleaning system according to claim 14, characterized in that the support is a member exhibiting one of the shapes of a sheet, a plate, a mesh, or an uneven surface.

17. The cleaning system according to claim 16, characterized in that the support is installed on the ceiling, wall, or floor of a partitioned space.

18. The purification system according to claim 12, characterized in that the ultraviolet light emitted from the light source belongs to a wavelength band of 200 nm or more and less than 240 nm.

19. The purification system according to claim 13, characterized in that an adsorbent that adsorbs specific substances contained in the air within the space is arranged within the space.

20. The support has a specific surface area of ​​1 m². 2 The purification system according to claim 14, characterized in that it is 1g or more.

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