Photocatalyst air purification unit and device

Abstract

The shape and structure of a photocatalyst air purification filter are mainly optimized to improve space efficiency and air purification capacity. In a photocatalyst air purification unit (11), a photocatalyst air purification filter (3a-3c) in which a metal porous body (12) carries a photocatalyst (2) is formed in a cylindrical shape. The cylindrical photocatalyst air purification filter (3a-3c) is arranged in one or multiple layers, and both ends are blocked by end plates (13). A space (15) inside the innermost cylindrical photocatalyst air purification filter (3a) is communicated with the outside by a first communication part (16) formed in one end plate (13).

Description

Photocatalytic air purification unit and device Technical Field

[0001] This invention relates to a photocatalytic air purification unit and device. Background Technology

[0002] Odor removal devices using photocatalysis have been put into practical use. These devices include a photocatalytic filter and a light source. The photocatalytic filter carries a photocatalyst, and the light source activates the photocatalyst. In these devices, the light source is turned on, activating the photocatalyst. The treated gas then passes through the photocatalytic filter, whereby the photocatalyst on the filter decomposes the odor components in the treated gas (see, for example, Patent Document 1).

[0003] In existing photocatalytic filters, the filter body uses a flat porous body (such as a ceramic porous body).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-050979 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] Therefore, in odor removal devices using photocatalysis, performance can be considered primarily dependent on the type of photocatalyst and light source used. Consequently, the photocatalyst filter itself has not received sufficient attention; for example, there has been no research on how the shape or structure of the photocatalyst filter affects the performance of the odor removal device. Therefore, there is still room for research and improvement regarding the shape and structure of photocatalyst filters.

[0009] Therefore, in view of the above circumstances, this application has studied the shape and structure of photocatalytic filters. Furthermore, an odor removal device using photocatalysis is described as an example to illustrate a flat-plate photocatalytic filter; however, the air purification device of this application is not limited to odor removal devices.

[0010] means for solving problems

[0011] Regarding the aforementioned issues, the photocatalytic air purification unit of this application is characterized in that the photocatalytic air purification filter carrying the photocatalyst in the metal porous body is formed into a cylindrical shape, the cylindrical photocatalytic air purification filter is configured as one or more layers, both ends are blocked by end plates, and the inner space of the innermost cylindrical photocatalytic air purification filter is connected to the outside through a first connecting portion formed in one of the end plates.

[0012] Invention Effects

[0013] According to this application, by optimizing the shape and structure of the photocatalytic air purifier filter through the above structure, space efficiency and air purification capacity can be improved. Attached Figure Description

[0014] Figure 1 is a diagram showing the installation state of the photocatalytic air purification device with the photocatalytic air purification unit in this embodiment relative to the building's ductwork.

[0015] Figure 2 is a perspective view showing the basic structure or principle of an air purifier using photocatalysis (in the case of using a flat-plate photocatalytic air purifier filter).

[0016] Figure 3 is a perspective view showing the individual shape of the photocatalytic air purification unit used in the photocatalytic air purification device.

[0017] Figure 4 is a longitudinal sectional view showing the internal structure of the photocatalytic air purification unit in Figure 3.

[0018] Figure 5 is a longitudinal sectional view of the upper part of the photocatalytic air purification unit as seen from the side, showing the airflow of the processed gas with the first connecting part serving as the inlet of the processed gas.

[0019] Figure 6 is a longitudinal sectional view of the upper part of the photocatalytic air purification unit as seen from the side, showing the airflow of the processed gas with the first connecting part serving as the outlet of the processed gas.

[0020] Figure 7A is a diagram showing the end face shape of a cylindrical photocatalytic air purification unit.

[0021] Figure 7B is a diagram showing the end face shape of a triangular photocatalytic air purification unit.

[0022] Figure 7C shows a configuration in which multiple hexagonal photocatalytic air purification units are bundled together and inserted into a duct.

[0023] Figure 8(a) is a diagram showing the shape and structure of the light source, and Figure 8(b) is a perspective view showing the setting state of the light source relative to the cylindrical photocatalytic air purification filter.

[0024] Figure 9 is a longitudinal sectional view of a horizontally positioned photocatalytic air purification device viewed from the side.

[0025] Figure 10 is a longitudinal sectional view of a vertically arranged photocatalytic air purification device viewed from the side.

[0026] Figure 11 is a longitudinal sectional view of a large-scale, vertically arranged photocatalytic air purification device viewed from the side.

[0027] Figure 12 is an exploded perspective view of the photocatalytic air purification unit used in the vertically arranged photocatalytic air purification device of Figure 11, cut in half.

[0028] Figure 13 is a part drawing of the end plate in Figure 12. Figure 13(a) is a bottom view, Figure 13(b) is a top view, and Figure 13(c) is a longitudinal sectional view.

[0029] Figure 14 is a top view of the light source used in the vertically oriented photocatalytic air purification device shown in Figure 11.

[0030] Figure 15A is a side view of the longitudinally arranged photocatalytic air purifier in a variation of the longitudinally arranged photocatalytic air purifier in Figure 11.

[0031] Figure 15B is a top view of Figure 15A.

[0032] Figure 16 is a longitudinal sectional view of the photocatalytic air purification unit located inside Figure 15A.

[0033] Figure 17 shows the upper end plate of the upper layer of Figure 16. Figure 17(a) is a top view and Figure 17(b) is a longitudinal sectional view.

[0034] Figure 18 shows the upper end plate of the lower layer of Figure 16. Figure 18(a) is a top view and Figure 18(b) is a longitudinal sectional view.

[0035] Figure 19 shows a split filter retaining member installed on the lower surface of the upper end plate. Figure 19(a) is a top view and Figure 19(b) is a longitudinal sectional view.

[0036] Figure 20 shows the lower end plate, which is common to both the upper and lower layers. Figure 20(a) is a top view, Figure 20(b) is a radial longitudinal sectional view of part A in Figure 20(a), Figure 20(c) is a radial longitudinal sectional view of part B in Figure 20(a), Figure 20(d) is a radial longitudinal sectional view of part C in Figure 20(a), and Figure 20(e) is a radial longitudinal sectional view of part D in Figure 20(a). Detailed Implementation

[0037] Hereinafter, this embodiment will be described in detail with reference to the accompanying drawings.

[0038] Figures 1 to 20 are used to illustrate this embodiment.

[0039]

Example 1

[0040] <Structure>

[0041] The structure of this embodiment will be described below.

[0042] As shown in Figure 2, the photocatalytic air purification device 1 shown in Figure 1 has a filter (photocatalytic air purification filter 3) carrying photocatalyst 2 and a light source 4 for activating photocatalyst 2.

[0043] The photocatalytic air purification device 1 is a device that uses a photocatalyst 2 to purify air or exhaust gas (treated gas 5). Treated gas 5 is the exhaust gas purified by the photocatalytic air purification device 1. Treated gas 5 can be any gas, if it contains odor components. Treated gas 5 can contain components other than odor components. Treated gas 5 passes through the photocatalytic air purification device 1 and is purified inside the device through a photocatalytic reaction, transforming from untreated gas into treated gas. The photocatalytic air purification device 1 includes an odor removal device. However, the photocatalytic air purification device 1 is not limited to an odor removal device.

[0044] Photocatalyst 2 is activated by light absorption, acting as a catalyst to induce chemical reactions in other substances (photocatalytic reactions). Photocatalytic reactions utilize the redox reaction between photocatalyst 2 and light. Through photocatalytic reactions, odor-causing components or other substances are decomposed into water, carbon dioxide, etc.

[0045] The photocatalytic air purifier filter 3 is a filter that carries a photocatalyst 2. The substrate 6 of the photocatalytic air purifier filter 3 uses a breathable refractory material. In the photocatalytic air purifier filter 3, when gas passes through (or through) the filter or moves along its surface, odor components or other substances come into contact with the photocatalyst 2, whereby they are decomposed through a photocatalytic reaction, thus purifying the air and removing odors. In the photocatalytic air purifier filter 3, adhering oil and other substances are also decomposed through a photocatalytic reaction. Therefore, the photocatalytic air purifier filter 3 also has a self-cleaning function. Compared to other types of air purifiers, the photocatalytic air purifier 1 has higher purification capacity, lower operating costs, and is easier to maintain and service.

[0046] Light source 4 generates light that activates photocatalyst 2. Light source 4 uses an ultraviolet lamp that generates UV-A (ultraviolet A waves with a wavelength range of 300-400 nm). Alternatively, for example, light source 4 can use an ultraviolet LED lamp that generates UV-A. Alternatively, light source 4 can also use a visible light LED lamp that generates visible light containing UV-A. Any one of ultraviolet lamps, ultraviolet LEDs, and visible light LEDs can be selected. Furthermore, at least two or more of ultraviolet lamps, ultraviolet LEDs, and visible light LEDs can be used in combination. The bactericidal effect produced by UV-A from these light sources 4 can be expected. The light intensity of light source 4 can be kept constant. Furthermore, light source 4 can be configured to allow adjustment of the light intensity. In this case, by increasing the light intensity, photocatalyst 2 can be further activated. Conversely, by decreasing the light intensity, the activation of photocatalyst 2 is suppressed. The light intensity is adjusted to the optimal value based on factors such as the flow rate of the processing gas 5.

[0047] For the basic structure described above, in this embodiment, it can have the following structure.

[0048] (1) First, Figure 3 shows the photocatalytic air purification unit 11.

[0049] As shown in the cross-sectional view of Figure 4, in this photocatalytic air purification unit 11,

[0050] The photocatalytic air purification filters 3a-3c, which carry the photocatalyst 2 on the metal porous body 12, are formed into a cylindrical shape.

[0051] The cylindrical photocatalytic air purifier filters 3a to 3c are configured as single or multiple (including double) filters, with both ends blocked by end plates 13.

[0052] The inner space 15 of the innermost cylindrical photocatalytic air purifier filter 3a is connected to the outside via a first connecting portion 16 formed on an end plate 13.

[0053] The cylindrical photocatalytic air purifier filters 3a-3c can be configured as a single-layer filter. Alternatively, they can be configured as a double or more layer filter. Preferably, the photocatalytic air purifier filters 3a-3c are configured as a double or more layer filter. When the cylindrical photocatalytic air purifier filters 3a-3c are configured as a double filter, most of the odor components in the treated gas 5 can be purified. When the cylindrical photocatalytic air purifier filters 3a-3c are configured as a triple or more filter, the treated gas 5 can be purified to a higher level. In practical use, a double to five-layer filter is preferred. In this embodiment, the cylindrical photocatalytic air purifier filters 3a-3c are configured as a triple filter. In this case, the cylindrical photocatalytic air purifier filters 3a-3c, whether single-layer or multiple-layer, can remain exposed. However, it is preferable that the photocatalytic air purifier filters 3a-3c are housed inside the housing 17. When the housing 17 is provided, as described later, the housing 17 can have an outer peripheral surface 17a and a pair of end surfaces 17b, 17c. The outer peripheral surface 17a surrounds the outer periphery of the cylindrical photocatalytic air purifier filters 3a-3c with a gap. The gap can be very small. The end faces 17b and 17c block the ends of the outer peripheral surface 17a, sealing the housing 17. Additionally, the end faces 17b and 17c can also block the ends of the cylindrical photocatalytic air purifier filters 3a-3c. Furthermore, a second connecting portion 19 is formed in the housing 17, communicating between the outside and the inside. The second connecting portion 19 communicates with the space 18 outside the outermost cylindrical photocatalytic air purifier filter 3b inside the housing 17. The second connecting portion 19 can be formed on the outer peripheral surface 17a of the housing 17. In this case, the second connecting portion 19 can be formed on a portion of the outer peripheral surface 17a of the housing 17. The second connecting portion 19 can be formed on the entire outer peripheral surface 17a of the housing 17. Alternatively, the second connecting portion 19 can also be formed on the end face 17c of the housing 17 (located on the opposite side of the first connecting portion 16). Alternatively, the second connecting portion 19 can be formed on the end plate 13. Furthermore, without the housing 17, the outermost cylindrical photocatalytic air purifier filter 3b performs the same function as the second connecting portion 19.

[0054] The photocatalytic air purification unit 11 is a modular structure that integrates the minimum required structure for air purification. The photocatalytic air purification unit 11 has at least one photocatalytic air purification filter 3 and a light source 4. The light source 4 illuminates the photocatalytic air purification filter 3, and the housing 17 can also be included within the photocatalytic air purification unit 11. In this embodiment, the photocatalytic air purification filter 3 has three photocatalytic air purification filters 3a to 3c. The photocatalytic air purification device 1 can be composed of one photocatalytic air purification unit 11. Alternatively, the photocatalytic air purification device 1 can be composed of multiple photocatalytic air purification units 11.

[0055] The porous metal 12 is a porous metal material used in various fields such as industrial filters and food processing filters. The porous metal 12 is a porous metal with countless tiny pores inside. The porous metal 12 has irregular and fine three-dimensional continuous pores on its front, back, and interior surfaces. The porous metal 12 has a three-dimensional mesh structure similar to a sponge. Therefore, the material itself is breathable. Thus, the porous metal 12 is a material with qualities completely different from porous plates, such as perforated plates, which are formed into a dense metal structure with regular pores through processing. The porous metal 12 preferably uses a material with a porosity of approximately 90% to 95%.

[0056] Furthermore, no examples have been found of using the porous metal body 12 as a substrate 6 of the photocatalytic air purifier filter 3 using the photocatalyst 2 instead of a filter, and applying it at a practical level. However, the porous metal body 12 is a permeable material that has a large surface area due to its fine, three-dimensional continuous pores, allowing the processed gas 5 to pass through (permeate). Therefore, by supporting the photocatalyst 2 on the continuous pores on the surface, back, and interior of the porous metal body 12, it is expected to be used as a photocatalytic air purifier filter 3.

[0057] Furthermore, compared to porous metal materials formed by sintering metal fibers or metal powders (sintered materials, sintered metals), the metal porous body 12 has a very high porosity (void ratio) and a different internal structure. Therefore, the metal porous body 12, as the object of this embodiment, is a material different from the sintered material, and is expected to be more suitable as a substrate 6 for the photocatalytic air purifier filter 3 than the sintered material. Moreover, the photocatalytic air purifier filter 3 was prototyped using the metal porous body 12, and various experiments and simulations were conducted. As a result, it was actually confirmed that the metal porous body 12 can serve as a good substrate 6 for the photocatalytic air purifier filter 3.

[0058] Plate-shaped (thick plate-shaped) porous metal bodies 12 are commercially available and can therefore be used. Preferably, the porous metal body 12 is made of a material formed from at least one of nickel, silver, copper, aluminum, nickel-chromium, nickel-tin, and nickel-iron. In particular, it is preferred that the material of the porous metal body 12 contains nickel.

[0059] Furthermore, the internal structure of the porous portion of the metal porous body 12 differs from that of the porous ceramic bodies used as photocatalytic filters to date. Therefore, the performance of the metal porous body 12 may differ from existing photocatalytic filters. Therefore, experiments were conducted using the metal porous body 12. The results showed that conditions exist for obtaining performance approximately the same as or better than that of ceramic porous bodies. These conditions are that the product of the thickness t and the average number of pores per inch (t×C) of the metal porous body 12 is between 100 and 400. The thickness t of the metal porous body 12 is an indicator related to the pressure loss of the processed gas 5. The average number of pores C is an indicator related to the contact opportunities between odor components and the photocatalyst 2. By satisfying the above conditions, the pressure loss and contact opportunities are optimized when using the metal porous body 12. For example, it was found that the thickness t and the average pore number C (ppi) are good when they are 15mm × 9ppi = 135, 10mm × 15ppi = 150, 10mm × 25ppi = 250, 15mm × 15ppi = 225, and 15mm × 25ppi = 375. That is, it was found that it is good to use metal porous bodies 12 with a thickness t of 10mm to 15mm and an average pore number C of 9ppi to 25ppi in combination such that the product (t × C) is 100 to 400. In addition, it was found that it is preferable to use metal porous bodies 12 with an ultraviolet transmittance of 8% or less. Ultraviolet transmittance is an indicator related to light utilization efficiency. By making the transmittance 8% or less and greater than 0%, the light utilization efficiency is maximized when using metal porous bodies 12, and the photocatalyst 2 on the surface, back side and inside of the metal porous body 12 is activated to the maximum extent.

[0060] Preferably, the photocatalyst 2 uses titanium dioxide. Alternatively, the photocatalyst 2 preferably uses a substance containing titanium dioxide. Preferably, the photocatalyst 2 is supported on the porous metal body 12 in a uniformly dispersed state without clogging continuous pores.

[0061] Regarding the cylindrical photocatalytic air purifier filter 3 (cylindrical metal porous filter), the photocatalytic air purifier filter 3 is formed in a cylindrical shape. By forming it in a cylindrical shape, the photocatalytic air purifier filter 3 directly becomes the passage for the treated gas 5. For a space of the same size, the cylindrical photocatalytic air purifier filter 3 can ensure a larger installation area compared to a flat plate filter. The cylindrical photocatalytic air purifier filter 3 can be formed by bending a flat plate metal porous body 12.

[0062] The cylindrical photocatalytic air purifier filter 3 can be formed into various shapes such as conical or pyramidal. Preferably, the cylindrical photocatalytic air purifier filter 3 has a substantially uniform thickness and a substantially uniform cross-sectional shape, and is a cylinder with a diameter that is substantially constant along its length. The cylindrical photocatalytic air purifier filter 3 can be formed into a cylindrical shape. Alternatively, the cylindrical photocatalytic air purifier filter 3 can be formed into a prismatic shape. Preferably, the cylindrical photocatalytic air purifier filter 3 is formed into a cylindrical shape. In this embodiment, as described above, multiple cylindrical photocatalytic air purifier filters 3a to 3c of the same length but different diameters are arranged concentrically. Therefore, the photocatalytic air purification unit 11 can simultaneously achieve structural simplification, centralization, and increased installation area of ​​the photocatalytic air purifier filters 3a to 3c. In this embodiment, as shown in Figures 5 and 6, by arranging the photocatalytic air purifier filters 3a to 3c in triplicate, the structure and scale of the photocatalytic air purification unit 11 are simplified and optimized. However, the number of cylindrical photocatalytic air purifier filters 3a to 3c does not have to be limited to three. For example, the number can also be two, four, or five or more.

[0063] The preferred multi-sized cylindrical photocatalytic air purifier filters 3a-3c are configured with gaps that are substantially uniform in the circumferential direction and extend along their entire length. When the cross-section of the cylindrical photocatalytic air purifier filters 3a-3c is circular, the gaps are uniform in the circumferential direction. When the cross-section of the cylindrical photocatalytic air purifier filters 3a-3c is angular, the gaps are uniform at the edges and non-uniform at the corners. Furthermore, the size of the circumferential gaps (radial dimensions) can vary in each layer. However, it is preferable that the sizes of the circumferential gaps are aligned equally in each layer.

[0064] In the cylindrical photocatalytic air purifier filters 3a to 3c, two passages for the processed gas 5 are formed on the inner and outer sides of the cylinder by abutting and blocking the two ends with the end plate 13. Moreover, in the cylindrical photocatalytic air purifier filters 3a to 3c, multiple passages for the processed gas 5 are formed in a layered manner (number of pipes + 1) by configuring them in multiple layers and blocking the two ends with the same end plate 13.

[0065] Furthermore, the cylindrical photocatalytic air purifier filters 3a-3c are clamped by a pair of end plates 13, thereby maintaining the gap between the cylinders and defining the passage for the treated gas 5. In each of the cylindrical photocatalytic air purifier filters 3a-3c, at least one end is mounted on the end plate 13, thereby fixing its position.

[0066] Alternatively, the housing 17 may not be provided. With the housing 17 provided, the cylindrical photocatalytic air purifier filters 3a-3c can be accommodated internally with gaps. The housing 17 can be of any size or shape. Preferably, the housing 17 is the same cylindrical shape as the cylindrical photocatalytic air purifier filters 3a-3c, and has a uniform cross-section along its entire length.

[0067] Therefore, the cylindrical housing 17 mainly has a cylindrical outer peripheral surface 17a (cylindrical portion) extending along the cylindrical photocatalytic air purifier filters 3a to 3c. Compared to the outermost cylindrical photocatalytic air purifier filter 3b, the cross-section of the outer peripheral surface 17a is larger, and its length is approximately the same or slightly longer. For example, the outer peripheral surface 17a can be thicker than the end plate 13 or end faces 17b, 17c of the photocatalytic air purifier filter 3b. Preferably, the cylindrical photocatalytic air purifier filters 3a to 3c are arranged in the housing 17 with their centers aligned with or near the center of the outer peripheral surface 17a, and with a substantially uniform circumferential spacing (outer space 18) between them and the outer peripheral surface 17a.

[0068] A pair of end faces 17b and 17c of the housing 17 are formed to block the two ends of the outer peripheral surface 17a. At least one of the end faces 17b and 17c can be formed to have a cross-section substantially the same size and shape as the outer peripheral surface 17a, and is disposed on the inner side so as to fit into the two ends of the outer peripheral surface 17a. Alternatively, at least one of the end faces 17b and 17c can also be formed to the size and shape required to abut the two ends of the outer peripheral surface 17a, and is disposed on the outer side of the outer peripheral surface 17a. In this embodiment, both end faces 17b and 17c are disposed on the inner side of the outer peripheral surface 17a.

[0069] The cylindrical outer peripheral surface 17a can have any cross-sectional shape. For example, the outer peripheral surface 17a can be formed with a circular cross-section. The circular cross-section can be formed as a perfect circle (Fig. 7A). The circular cross-section can be any circle such as an oblong or elliptical. Alternatively, for example, the outer peripheral surface 17a can be formed with a angular cross-section. Preferably, the angular cross-section is a polygonal cross-section, and more preferably a regular polygonal cross-section. The angular cross-section can be formed as a triangle (Fig. 7B). The angular cross-section can be formed as a quadrilateral. The angular cross-section can be formed as any shape such as a pentagon or heptagon. In this embodiment, the housing 17 is formed with a (regular) hexagonal cross-section (Fig. 7C). Thus, the housing 17 can easily accommodate the cylindrical photocatalytic air purifier filters 3a-3c inside, and when accommodated, it is easy to form a uniform and close circumferential gap between the housing 17 and the cylindrical photocatalytic air purifier filters 3a-3c. Furthermore, for the (regular) hexagonal cross-section of the housing 17, it is easier to ensure strength by allowing the housings 17 to fit tightly against each other and combining a larger number of housings 17. Additionally, the same advantages as the hexagonal cross-section can be obtained when the housing 17 is formed with a triangular or quadrilateral cross-section. The angular cross-section housing 17 can also be arranged by combining housings with different cross-sectional shapes. Preferably, the cylindrical photocatalytic air purifier filters 3a-3c housed within the housing 17 are formed in a cylindrical shape. However, the photocatalytic air purifier filters 3a-3c can be formed with an angular cross-section greater than a triangle. For example, the photocatalytic air purifier filters 3a-3c can also be formed with a triangular cross-section, etc. In this case, it is preferable that the cylindrical photocatalytic air purifier filters 3a-3c are formed as prismatic tubes with the same cross-sectional shape as the housing 17, and are arranged concentrically at the positions of the aligned surfaces and corners in the circumferential direction. Thus, for example, the installation area of ​​the photocatalytic air purifier filters 3a to 3c with triangular cross-section (angular cross-section) relative to the housing 17 with triangular cross-section (angular cross-section) can be increased.

[0070] The outer peripheral surface 17a of the housing 17 can be formed of any material. Preferably, the outer peripheral surface 17a is formed of metal. Alternatively, the outer peripheral surface 17a can also be formed of resin or other materials. Preferably, the housing 17 uses a thin-walled material with shape retention. For example, as shown in FIG3, the outer peripheral surface 17a can be made solely of a flat plate material (non-porous material 21) of a general material without permeability. Alternatively, for example, the outer peripheral surface 17a can be made of a porous material 22. Alternatively, non-porous material 21 and porous material 22 can be used in combination. Non-porous material 21 is a material that has no pores of its own. Porous material 22 includes a perforated plate 22a obtained by sheet metal processing of a flat plate material. For example, perforated plate 22a includes a perforated metal plate with multiple through holes formed on the flat plate material. Perforated plate 22a also includes expanded metal mesh, which is formed by processing multiple through cuts in the flat plate material and stretching it in the planar direction. In addition, the porous plate 22a also includes a stamped material having multiple through holes formed by cutting on a flat plate material. The porous plate 22a also includes a stamped material having multiple bridges formed by cutting and bending. In addition, the porous material 22 includes porous material 22b made of materials other than flat plate materials. Porous material 22b includes, for example, a metal mesh. Porous material 22b includes metal filter material that integrates metal fibers such as aluminum into a breathable form and is processed into a plate shape. When the porous material 22b has poor shape retention, it can be installed in a frame or the like. The outer peripheral surface 17a of the housing 17 can also use the above-mentioned metal porous body 12. Furthermore, when the porous material 22 is used as the outer peripheral surface 17a of the housing 17, the outer space 18 of the photocatalytic air purifier filter 3b can be basically eliminated.

[0071] Furthermore, in the accompanying drawings, for the purpose of illustration, non-porous material 21 and porous material 22 (porous plate 22a, porous material 22b) are respectively disposed on each surface of the outer peripheral surface 17a of the housing 17. However, in practice, the entire circumference of the outer peripheral surface 17a of the housing 17 is formed of the same material. Moreover, if necessary, a portion of the outer peripheral surface 17a can be appropriately combined with other materials for use.

[0072] At or near the ends of the outer peripheral surface 17a, a pair of end faces 17b and 17c of the housing 17 are arranged spaced apart from each other and substantially parallel. End faces 17b and 17c can be formed of any material. Preferably, end faces 17b and 17c are formed of metal. End faces 17b and 17c can also be formed of resin or other materials. End faces 17b and 17c use a flat, non-porous material (non-porous material 21) of a general material that is not breathable. Through subsequent processing, a first connecting portion 16 and a second connecting portion 19 are appropriately formed through such end faces 17b and 17c. End faces 17b and 17c can be integrally formed with the outer peripheral surface 17a of the housing 17. End faces 17b and 17c can also be formed from components separate from the outer peripheral surface 17a. Moreover, end faces 17b and 17c formed from separate components can be configured to be detachable (or disassembled) relative to the outer peripheral surface 17a. Therefore, internal maintenance can be performed by removing end faces 17b and 17c from the outer peripheral surface 17a. End faces 17b and 17c can be used as end plates 13 to block both ends of the cylindrical photocatalytic air purification filters 3a to 3c. However, end plates 13 can also be formed from components separate from end faces 17b and 17c.

[0073] The inner space 15 is the passageway for the processing gas 5 at the innermost part of the photocatalytic air purification unit 11, forming the innermost cylindrical photocatalytic air purification filter 3a internal space (first space).

[0074] The first connecting portion 16 is an opening that connects the inner space 15 to the outside. When the end face 17b and the end plate 13 are identical components, the first connecting portion 16 is a through hole that penetrates approximately the center of the end face 17b (end plate 13). The approximately center position corresponds to or matches the position of the inner space 15. In this embodiment, the first connecting portion 16 is formed with a diameter approximately the same as or slightly smaller than the inner diameter of the innermost cylindrical photocatalytic air purifying filter 3a, and with the same (cross-sectional) shape. Therefore, the first connecting portion 16 can ensure a larger opening area. Alternatively, the first connecting portion 16 is a connecting port that directly connects the outside of the housing 17 to the inner space 15. For example, when the end face 17b and the end plate 13 are separate components, the first connecting portion 16 is formed as a cylindrical component that penetrates both the end face 17b and the end plate 13 from the outside. As described later, when the photocatalytic air purifying units 11 are connected in series, the first connecting portion 16 can also be used to connect adjacent inner spaces 15 to each other.

[0075] The outer space 18 is formed inside the outer peripheral surface 17a of the housing 17 and serves as the passage for the outermost processed gas 5. Alternatively, the outer space 18 is formed as the outer space (second space) of the outermost cylindrical photocatalytic air purifier filter 3b. The outer space 18 is formed as an annular passage extending along the circumferential and longitudinal directions of the outermost cylindrical photocatalytic air purifier filter 3b.

[0076] When the housing 17 is provided, the second connecting portion 19 is configured as a hole connecting the outer space 18 to the outside, or a connecting hole connecting the outside of the housing 17 to the outer space 18, etc. The second connecting portion 19 is formed as a through hole that penetrates the outer peripheral portion of the end face 17c (or end plate 13) on the opposite side of the first connecting portion 16. Alternatively, the second connecting portion 19 is formed as a through hole that penetrates the outer peripheral surface 17a of the housing 17.

[0077] The second connecting portion 19, provided on end face 17c, is formed at a position on the outer peripheral side corresponding to (matching) the outer space 18. The second connecting portion 19 provided on the outer peripheral surface 17a can be provided at any position on the outer peripheral surface 17a. For example, when the outer peripheral surface 17a is made of non-porous material 21, it is preferable that the second connecting portion 19 is provided near the other end face 17c, which is furthest from the first connecting portion 16. In this case, one or more second connecting portions 19 can be provided on either end face 17c or outer peripheral surface 17a. Alternatively, one or more second connecting portions 19 can be provided on both end face 17c and outer peripheral surface 17a. Moreover, it is preferable that a plurality of second connecting portions 19 are formed at equal intervals in the circumferential direction. The size and number of the second connecting portions 19 can be adjusted to form the same opening area as the first connecting portion 16. However, the opening area of ​​the second connecting portion 19 can also be made larger than that of the first connecting portion 16. Conversely, the opening area of ​​the second connecting portion 19 can also be made smaller than that of the first connecting portion 16.

[0078] Furthermore, when the outer peripheral surface 17a is entirely or partially made of porous material 22, multiple second connecting portions 19 are formed in the portion of porous material 22. In this case, it is preferable that the second connecting portions 19 are provided over the entire area of ​​the outer peripheral surface 17a. The use of porous material 22 on the outer peripheral surface 17a allows it to function as a grease filter, trapping oil contained in the processed gas 5. To trap oil, the grease filter is positioned upstream of the airflow of the processed gas 5, as needed.

[0079] Furthermore, when the cylindrical photocatalytic air purifier filters 3a to 3c are formed as a multi-layered structure, in addition to the inner space 15 and the outer space 18, intermediate spaces 23 and 24 (Fig. 4) (third space) are also formed inside the housing 17. The intermediate spaces 23 and 24 form one or more (number of pieces - 1) gaps between the cylindrical photocatalytic air purifier filters 3a to 3c of different sizes (or inner and outer dimensions). The intermediate spaces 23 and 24 form annular passages extending along the circumferential and longitudinal directions of the cylindrical photocatalytic air purifier filters 3a to 3c. For example, when the cylindrical photocatalytic air purifier filters 3a to 3c are formed as a triple-layered structure, two intermediate spaces 23 and 24 are formed between the three cylindrical photocatalytic air purifier filters 3a to 3c. Moreover, the inner space 15, the intermediate spaces 23 and 24 (each space), and the outer space 18 are each formed as independent spaces, connected only by continuous air vents in the photocatalytic air purifier filters 3a to 3c.

[0080] As shown in Figure 8, it is preferable to arrange the light source 4 (Figure 8(a)) in the intermediate spaces 23 and 24 (Figure 8(b)). Preferably, the light source 4 is configured to illuminate the entire area of ​​the cylindrical photocatalytic air purifier filters 3a-3c approximately equally along both the length and circumference. One light source 4 can be arranged in the intermediate spaces 23 and 24. Multiple light sources 4 can be arranged in the intermediate spaces 23 and 24. The light source 4 is configured to illuminate both the cylindrical photocatalytic air purifier filters 3a-3c, both inside and outside the intermediate spaces 23 and 24.

[0081] When there are multiple intermediate spaces 23 and 24, it is preferable that the light source 4 is disposed in all of the intermediate spaces 23 and 24. For example, the light source 4 can be formed as a linear illumination unit consisting of multiple light-emitting elements 4a connected together to form a line, with a length and width approximately the same as the intermediate spaces 23 and 24. This linear illumination unit is integrated back-to-back to emit light from both sides. Alternatively, the light source 4 can be a component consisting of multiple light-emitting elements 4a mounted on one side of a slender support plate 4b having a width approximately the same as the intermediate spaces 23 and 24, and attached back-to-back or mounted on two sides, thereby enabling light emission from both sides. The support plate 4b is formed as a whole with a length approximately the same as the intermediate spaces 23 and 24. One or more support plates 4b can also be connected to form the aforementioned length. In the accompanying drawings, two support plates 4b are connected. One support plate 4b can also be used. Three or more support plates 4b can also be connected. For example, it is preferable to process an anti-fouling coating on the surface of the light source 4. The anti-fouling coating can be made using coating agents such as silicone or fluorine. Furthermore, the elongated light source 4 described above is configured to be inserted into the intermediate spaces 23 and 24 in a radial manner along the length of the cylindrical photocatalytic air purification filters 3a to 3c. However, the structure of the light source 4 is not limited to the above-described structure.

[0082] In the intermediate spaces 23 and 24, multiple elongated light sources 4 extending in the longitudinal direction are arranged circumferentially at intervals required to illuminate the light approximately evenly. In this embodiment, six elongated light sources 4 are arranged at equal intervals in the circumferential direction. However, the number of elongated light sources 4 is not limited to six. By installing elongated light sources 4 at multiple locations in the circumferential direction, the intermediate spaces 23 and 24 of each layer are divided into multiple arc-shaped sections. In the intermediate spaces 23 and 24, since the processing gas 5 does not need to flow around in such a circumferential direction, it is not affected even if they are separated by elongated light sources 4. Furthermore, by narrowing the width dimension of the linear illumination, it is possible not to separate the intermediate spaces 23 and 24. When there are multiple intermediate spaces 23 and 24, as shown in FIG8(b), elongated light sources 4 can be arranged at the same position in the circumferential direction between the inner and outer layers. When the intermediate spaces 23 and 24 are divided into multiple circumferential parts by using a slender light source 4, it is preferable that another end face 17c or a second connecting portion 19 formed by a non-porous material 21 on the outer circumferential surface 17a is provided separately in each of the divided parts.

[0083] The elongated light source 4 has at least one end mounted on an end plate 13 (or end face 17b, 17c), and its position is fixed. In this case, the cylindrical photocatalytic air purifier filters 3a-3c can also use the elongated light source 4 fixed on the end plate 13 as a retaining member to maintain its radial position. Alternatively, the cylindrical photocatalytic air purifier filters 3a-3c can also maintain their radial position using other retaining members besides the light source 4 fixed on the end plate 13.

[0084] By arranging the light source 4 in the intermediate spaces 23 and 24, regardless of whether either the first connecting portion 16 or the second connecting portion 19 is used as the inlet portion 31, it is possible to prevent untreated gas entering the housing 17 from the inlet portion 31 from directly contacting the light source 4. Therefore, oil and other contaminants contained in the untreated gas can be prevented from directly adhering to the light source 4. Furthermore, if the adhering of oil and other contaminants becomes a problem by providing an grease filter, the light source 4 can also be placed in the inner space 15 or the outer space 18.

[0085] (2) As shown in Figure 5, the first connecting part 16 can also serve as the inlet part 31 of the processed gas 5. Therefore, the second connecting part 19 serves as the outlet part 32 of the processed gas 5.

[0086] In the photocatalytic air purification unit 11, the inlet 31 and outlet 32 ​​can be freely configured according to the orientation of the airflow relative to the processed gas 5. The inlet 31 is an opening on the upstream side where the processed gas 5 enters the housing 17. The first connecting portion 16 serves as the inlet 31 by being positioned on the upstream side of the airflow of the processed gas 5. The outlet 32 ​​is an opening on the downstream side where the processed gas 5 flows out of the housing 17. The second connecting portion 19 serves as the outlet 32 ​​on the downstream side of the airflow of the processed gas 5. Thus, for example, in the photocatalytic air purification unit 11, the processed gas 5 enters from the center and exits from the outer periphery. When the first connecting portion 16 serves as the inlet 31 of the processed gas 5, the aforementioned grease filter can also be provided. Alternatively, a grease filter may not be provided. When a grease filter is provided, it is preferable that the grease filter is positioned around the periphery of the first connecting portion 16 in the end plate 13, covering the first connecting portion 16. The periphery of the first connecting portion 16 can be the inlet side of the first connecting portion 16. The periphery of the first connecting portion 16 can also be the interior of the first connecting portion 16. The periphery of the first connecting portion 16 can also be the outflow side of the first connecting portion 16. The grease filter can use a breathable member with a mesh size capable of capturing oil contained in untreated gas. For example, the breathable member can be formed as a mesh. For example, the breathable member can be a non-woven fabric. In this case, by installing the breathable member around the first connecting portion 16, the photocatalytic air purification unit 11 becomes a unit with a grease filter (grease filter built-in type unit). The breathable member can be installed in a detachable manner. Alternatively, the breathable member can also be installed in a non-detachable manner.

[0087] (3) Alternatively, as shown in FIG6, the first connecting portion 16 can serve as the outlet portion 32 of the processed gas 5. Thus, the second connecting portion 19 serves as the inlet portion 31 of the processed gas 5.

[0088] The outlet 32 ​​is an open portion on the downstream side where the processed gas 5 flows out of the housing 17. The first connecting portion 16 is provided on the downstream side of the airflow of the processed gas 5, thus becoming the outlet 32. The inlet 31 is an open portion on the upstream side where the processed gas 5 flows into the housing 17. The second connecting portion 19 is provided on the upstream side of the airflow of the processed gas 5, thus becoming the inlet 31. Therefore, for example, in the photocatalytic air purification unit 11, the processed gas 5 enters from the outer periphery and flows out from the center. When the second connecting portion 19 is used as the inlet 31 of the processed gas 5, the aforementioned grease filter can be provided. Alternatively, the grease filter may not be provided. When a grease filter is provided, it is preferable to provide the grease filter around the second connecting portion 19 in a manner that covers the second connecting portion 19. The periphery of the second connecting portion 19 can be the inlet side of the second connecting portion 19. The periphery of the second connecting portion 19 can also be the interior of the second connecting portion 19. The periphery of the second connecting portion 19 can also be the outlet side of the second connecting portion 19. The grease filter uses the same permeable member as described above. In this case, by installing the breathable member around the second connecting portion 19, the photocatalytic air purification unit 11 becomes a unit with a grease filter (grease filter built-in type unit). The breathable member can be installed in a detachable manner. Alternatively, the breathable member can also be installed in a non-detachable manner. In particular, as described above, when the porous material 22 is used as the second connecting portion 19, the porous material 22 functions as a grease filter, and in this case, the breathable member serving as a grease filter can also be provided separately from the porous material 22.

[0089] The following describes the photocatalytic air purification device 1 having the above-described photocatalytic air purification unit 11.

[0090] (4) Regarding the photocatalytic air purification device 1, one of the above-mentioned photocatalytic air purification units 11 or multiple of the above-mentioned photocatalytic air purification units 11 as shown in FIG7C can be combined and placed in the pipe 41 through which the processed gas 5 passes in such a way that the entire passage cross section of the pipe 41 is blocked (FIG1).

[0091] The duct 41 is a conduit through which the processed gas 5 passes. For example, as shown in Figure 1, such a duct 41 is installed inside a building 42, such as a commercial facility, as an intake duct or an exhaust duct. The photocatalytic air purification device 1 can be installed in the intake duct. The photocatalytic air purification device 1 can be installed in the exhaust duct. The photocatalytic air purification device 1 can be installed in other ducts 41 through which the processed gas 5 flows. Thus, the interior space of the duct 41 becomes the exterior of the photocatalytic air purification unit 11. In the building 42, the duct 41 has at least an independent duct 43 (or a floor-to-floor duct) that extends laterally on each floor. The duct 41 may have a converging duct 44 that merges the independent ducts 43 and crosses between floors and extends vertically. The independent ducts 43 are arranged laterally along the ceiling portion of each floor of the building 42. The converging duct 44 is arranged substantially vertically in the duct space that runs vertically through the interior of the building 42. Alternatively, the converging duct 44 may also be arranged substantially vertically along the exterior wall of the building 42. The confluence duct 44 can extend to the roof of the building 42. The duct 41 can have a circular cross-section. The duct 41 can also have an angular cross-section. The duct 41 can also have other cross-sectional shapes. As needed, at least one of the photocatalytic air purification device 1 and the duct 41 can be appropriately provided with a fan 45 (Fig. 10) for flowing the processed gas 5 into the duct 41. The fan 45 can make the processed gas 5 flow into the duct 41 at a specified flow rate (air volume). In addition, the fan 45 can adjust the flow rate of the processed gas 5 flowing in the duct 41. In this case, by increasing the rotation speed of the fan 45, the flow rate of the processed gas 5 increases. Conversely, by slowing down the rotation speed of the fan 45, the flow rate of the processed gas 5 decreases. Furthermore, for example, the rotation speed of the fan 45 can be controlled in conjunction with the light intensity of the light source 4. In the case where a grease filter is separately provided from the photocatalytic air purification unit 11 (split-type grease filter), the grease filter is provided in the duct 41 in a manner located upstream of the overall photocatalytic air purification device 1. Alternatively, multiple grease filters can be installed in the duct 41 in such a way that they are located upstream of each photocatalytic air purification unit 11.

[0092] The photocatalytic air purification device 1 is mainly composed of a photocatalytic air purification unit 11, which has a cylindrical photocatalytic air purification filter 3 made of a metal porous body 12 as the substrate. The photocatalytic air purification unit 11 is installed in the pipe 41 to block the entire passage cross-section of the pipe 41, thereby allowing all the treated gas 5 flowing in the pipe 41 to pass through the interior of the photocatalytic air purification unit 11. The photocatalytic air purification unit 11 is installed in at least one of an independent pipe 43 and a converging pipe 44.

[0093] In this case, it is preferable that the photocatalytic air purification unit 11 is installed in the pipe 41 with the length direction of the cylindrical photocatalytic air purification filter 3 parallel to the flow direction (especially the inflow direction) of the processed gas 5. However, depending on the situation, as will be described later, the photocatalytic air purification unit 11 can also be installed in a direction that intersects the flow direction of the processed gas 5 along the length of the cylindrical photocatalytic air purification filters 3a to 3c. In particular, when the second connecting portion 19 is formed on the outer peripheral surface 17a of the housing 17, or when the outer peripheral surface 17a is formed of porous material 22, the inflow and outflow directions of the processed gas 5 are different through the first connecting portion 16 and the second connecting portion 19. Thus, in this case, the photocatalytic air purification unit 11 is configured to be easily installed with the length direction of the cylindrical photocatalytic air purification filters 3a to 3c orthogonal to the flow direction of the processed gas 5.

[0094] For example, by providing a partition member 46 (Fig. 9) inside the pipe 41 to block the entire cross-section of the pipe 41, a photocatalytic air purification unit 11 can be installed on this partition member 46. Alternatively, multiple partition members 46 can be installed in the photocatalytic air purification unit 11. Moreover, the photocatalytic air purification unit 11 can be installed on the partition member 46 in a state where the inlet portion 31 or the outlet portion 32 is aligned (or connected) with one or more through portions provided on the partition member 46. In addition, if the outer peripheral surface 17a is entirely formed of a non-porous material 21, the photocatalytic air purification unit 11 can be configured as a through portion of the partition member 46 such that the inlet portion 31 and the outlet portion 32 are separated on both sides of the partition member 46. In this case, a grease filter can be provided on the upstream side of the partition member 46. Alternatively, a grease filter can be provided on the upstream side of the inlet portion 31 of each photocatalytic air purification unit 11.

[0095] Alternatively, as shown in Figure 7C, multiple photocatalytic air purification units 11 are arranged side-by-side and bundled together, and directly inserted into the pipe 41, thereby substantially blocking the entire cross-section of the pipe 41. In this case, partitions 46 are provided to separate the gaps between the photocatalytic air purification units 11 and between the bundled photocatalytic air purification units 11 and the pipe 41, dividing the gaps into an inlet portion 31 and an outlet portion 32. Furthermore, the entire cross-section is appropriately blocked by the partitions 46. Additionally, the shape of the photocatalytic air purification unit 11 can be adjusted or changed to match the cross-sectional shape of the pipe 41, thus eliminating the need for the partitions 46. The overall shape of the photocatalytic air purification unit 11 can also be adjusted or changed according to the cross-sectional shape of the pipe 41. A portion of the shape of the photocatalytic air purification unit 11 can also be adjusted or deformed to match the cross-sectional shape of the pipe 41, for example, the shape of the outer portion. In this case, the grease filter can be placed upstream of the inlet 31 of the bundled photocatalytic air purification unit 11.

[0096] Additionally, a cavity 47 (Fig. 9) larger than the cross-sectional area of ​​the pipe 41 is provided midway through the pipe 41, and the photocatalytic air purification unit 11 is disposed within the cavity 47. The cavity 47 can be disposed at the end of the pipe 41. Similar to any of the above structures, the photocatalytic air purification unit 11 can be disposed within this cavity 47 (indirectly disposed within the pipe 41). For example, a partition member 46 is provided in the cavity 47, and the photocatalytic air purification unit 11 is mounted on the partition member 46. The photocatalytic air purification unit 11 is bundled and disposed within the cavity 47. The partition member 46 and the photocatalytic air purification unit 11 are combined and disposed within the cavity 47. In this case, the partition member 46 is configured to divide the interior of the cavity 47 into an upstream space 47a and a downstream space 47b. Furthermore, in addition to being disposed within the pipe 41 as described above, a grease filter can also be disposed at the inlet of the cavity 47. In addition, the grease filter can be installed on the upstream side of the partition member 46 inside the cavity 47 or on the upstream side of the photocatalytic air purification unit 11.

[0097] For maintenance purposes, the photocatalytic air purification unit 11 is preferably installed in the duct 41 or cavity 47 in a detachable manner. Therefore, in the photocatalytic air purification device 1, the duct 41 or cavity 47 has an opening for the photocatalytic air purification unit 11 to enter and exit. The opening can be opened and closed.

[0098] Furthermore, multiple layers of the aforementioned photocatalytic air purification device 1 can be arranged in series along the flow direction of the processed gas 5 within the pipe 41 or cavity 47. Each layer of the photocatalytic air purification device 1 may have one photocatalytic air purification unit 11. Alternatively, each layer of the photocatalytic air purification device 1 may be a component formed by bundling multiple photocatalytic air purification units 11 side by side. Each layer of the photocatalytic air purification device 1 may be configured such that the photocatalytic air purification unit 11 is installed on a partition member 46 that blocks the passage cross-section of the pipe 41 or cavity 47. The photocatalytic air purification device 1 can be different for each layer. As a result, the purification capacity of the processed gas 5 is further improved.

[0099] (5) As shown in Figure 1, the photocatalytic air purification unit 11 can be installed at at least one of the inlet section 51, the middle section 52, and the outlet section 53 of the pipe 41.

[0100] In this configuration, the photocatalytic air purification unit 11 can be installed at at least one of the following locations on the duct 41: the inlet section 51, the intermediate section 52, and the outlet section 53. Alternatively, the photocatalytic air purification unit 11 can be installed at two or more of these locations. For example, the photocatalytic air purification unit 11 can be installed at both the inlet section 51 and the intermediate section 52 of the duct 41. The photocatalytic air purification unit 11 can also be installed at both the inlet section 51 and the outlet section 53 of the duct 41. The photocatalytic air purification unit 11 can also be installed at both the intermediate section 52 and the outlet section 53 of the duct 41.

[0101] For example, a photocatalytic air purification unit 11 is installed at the inlet portion 51 of the duct 41 as a photocatalytic air purification device 1. In this case, the inlet portion 51 of the duct 41 is formed at or near the upstream end of the independent duct 43 (the upstream side portion), etc. One or more inlet portions 51 are formed in the duct 41. The duct 41 branches into multiple parts, which can form multiple inlet portions 51. For example, in the case of exhaust ducts in commercial facilities, the inlet portion 51 of the independent duct 43 is mostly located at a position that matches one or more kitchen facilities 54 installed on each floor of the building 42. Each inlet portion 51 of the independent duct 43 in each kitchen facility 54 is equipped with a range hood 55. Moreover, for example, a photocatalytic air purification device 1 (individually distributed photocatalytic air purification device 1a) is separately installed (built-in) for each range hood 55 of all kitchen facilities 54 on each floor. In this case, the treated gas 5 is cooking gas generated from the kitchen facility 54. The cooking gas mainly contains odor components such as toluene or acetaldehyde. In addition to cooking gases, cooking gases also contain oil, microparticles, polycyclic aromatic hydrocarbons (PAHs), and other substances. The photocatalytic air purification device 1 decomposes these substances through a photocatalytic reaction. However, the treated gas 5 is not limited to cooking gases. For example, the treated gas 5 could be exhaust gases from factories, etc. In this case, a grease filter can be installed at the inlet of the range hood 55.

[0102] For example, a photocatalytic air purification unit 11 can be installed in the middle portion 52 of a duct 41 as a photocatalytic air purification device 1. In this case, the middle portion 52 of the duct 41 can be any location within a large range between the inlet portion 51 and the outlet portion 53. For example, it is preferable that the middle portion 52 is the merging portion of an independent duct 43 with a confluence duct 44 or its vicinity (the downstream portion of the independent duct 43). In this case, at least for each of the independent ducts 43, there is a total number of photocatalytic air purification devices 1 (medium-scale decentralized photocatalytic air purification device 1b) with independent ducts 43 installed. For example, it is preferable that the photocatalytic air purification device 1 is installed upstream of a fire damper 56, which is installed in the independent ducts 43 on each floor and cuts off the independent ducts 43 and the confluence duct 44. In this case, one or more grease filters can be installed between the inlet portion of the range hood 55 and the inlet side of the medium-scale decentralized photocatalytic air purification device 1b.

[0103] For example, a photocatalytic air purification unit 11 is installed at the outlet portion 53 of the duct 41 as a photocatalytic air purification device 1. In this case, the outlet portion 53 of the duct 41 is located at or near the downstream end of the confluence duct 44. The downstream end of the confluence duct 44 becomes the upper part of or near the confluence duct 44 leading to the roof of the building 42, etc. Thus, the photocatalytic air purification device 1 is centrally installed on the roof of the building 42, etc., and connected to the outlet portion 53 of the duct 41 (centralized photocatalytic air purification device 1c). The air or treated gas 5 (treated gas) purified by the photocatalytic air purification device 1 on the roof of the building 42 is directly discharged into the atmosphere. In this case, one or more grease filters can be installed between the inlet portion of the range hood 55 and the inlet side of the centralized photocatalytic air purification device 1c.

[0104] Figure 9 shows an embodiment of the structure of a more specific photocatalytic air purifier 1. This photocatalytic air purifier 1 is a horizontally oriented type (horizontal photocatalytic air purifier). Hereinafter, an example of a centralized photocatalytic air purifier 1c will be described, but the horizontally oriented photocatalytic air purifier is not limited to this; for example, it could also be a medium-scale decentralized photocatalytic air purifier 1b, etc.

[0105] In this photocatalytic air purification device 1, there is an air inlet 47c connected to a duct 41 on one side (left side in the figure) along the length direction, and an elongated cavity 47 on the other side (right side in the figure) on which an exhaust duct 47d is installed. The outlet portion 53 of the duct 41 is installed in the air inlet 47c. An exhaust louver 57 is installed in the exhaust duct 47d. The interior of the cavity 47 is divided into an upstream (left side in the figure) space 47a and a downstream (right side in the figure) space 47b by a substantially vertical partition member 46. In the upstream space 47a within the cavity 47, the photocatalytic air purification unit 11 is arranged separately from the connection portion of the duct 41's outlet portion 53 and the inner surface of the cavity 47 with a required interval. In this case, a grease filter is provided around the periphery of the connection portion of the cavity 47 to the outlet portion 53 of the duct 41.

[0106] Regarding the photocatalytic air purification unit 11, the cylindrical photocatalytic air purification filters 3a-3c can be positioned with their length direction oriented laterally (approximately horizontal), and a structure can be formed by creating a second connecting portion 19 around the entire circumference of the outer peripheral surface 17a of the housing 17 made of porous material 22. In this embodiment, multiple photocatalytic air purification units 11 are connected in series along their length. As a result, the purification capacity of the photocatalytic air purification device 1 for purifying the gas 5 is improved. Adjacent photocatalytic air purification units 11 are arranged continuously and integrated with one end plate 13 having the first connecting portion 16 facing the exhaust louver 57 side. The end plates 13 between adjacent photocatalytic air purification units 11 can share one end plate 13 having the first connecting portion 16 as an intermediate plate 14. By using a universal intermediate plate 14, multiple photocatalytic air purification units 11 can be compactly connected. The intermediate plate 14 is ring-shaped and has an inner diameter that is approximately equal to the inner diameter of the innermost cylindrical photocatalytic air purifier filter 3a and an outer diameter that is approximately equal to the outermost cylindrical photocatalytic air purifier filter 3b or the outer peripheral surface 17a of the housing 17. Furthermore, the intermediate plate 14 connects adjacent inner spaces 15 to each other and blocks adjacent intermediate spaces 23, 24 from each other or adjacent outer spaces 18 from each other. Moreover, when multiple photocatalytic air purifier units 11 are connected in series along the length direction, only one closed end plate 13 without the first connecting portion 16 is required.

[0107] Furthermore, the photocatalytic air purification unit 11 is installed in the cavity 47 (upstream space 47a) with the first connecting portion 16 of one end plate 13 (end face 17b) closest to the exhaust louver 57 connected to the through portion of the partition member 46. Thus, the other end plate 13 (end face 17c) without an opening faces the outlet portion 53 of the duct 41 (left side in the figure).

[0108] Thus, the second connecting portion 19 on the outer peripheral surface 17a of the housing 17 becomes the inlet portion 31, through which the treated gas 5, which enters the upstream space 47a of the cavity 47 from the pipe 41, is drawn into the photocatalytic air purification unit 11. Furthermore, the first connecting portion 16 becomes the outlet portion 32 for the treated gas 5, which allows the purified treated gas 5 to pass through the center of the photocatalytic air purification unit 11 and into the downstream space 47b of the cavity 47, and is released to the atmosphere via the exhaust louvers 57. Additionally, the cavity 47 can support the various parts of the photocatalytic air purification unit 11.

[0109] Figure 10 shows a modified example of the photocatalytic air purifier 1 of Figure 9, which is configured in a way that allows for a small installation area (vertical type photocatalytic air purifier). In this vertical type photocatalytic air purifier, the air purification unit 11 is arranged in a longitudinally long cavity 47 with the length direction of the cylindrical photocatalytic air purifier filters 3a to 3c oriented longitudinally (approximately vertically). The cavity 47 is located midway through the outlet portion 53 of the pipe 41. In the photocatalytic air purifier unit 11, the second connecting portion 19 of the outer peripheral surface 17a of the housing 17 serves as the inlet portion 31. For example, the partition member 46 is formed as a cylinder with a size and shape approximately the same as the outer shape of the cylindrical photocatalytic air purifier filters 3a to 3c. The partition member 46 is configured to support the photocatalytic air purifier filters 3a to 3c on the lower side of the cavity 47, separating the photocatalytic air purifier filters 3a to 3c from the bottom surface of the cavity 47. Thus, the partition member 46 supports the lower part of the photocatalytic air purifier unit 11 with the bottom surface of the cavity 47. The downstream space 47b is formed inside the partition member 46. The rest of the structure is basically the same as the horizontally oriented photocatalytic air purification device in Figure 9. The photocatalytic air purification unit 11 can be configured as a single layer. Alternatively, the photocatalytic air purification unit 11 can be configured as multiple layers. In the accompanying drawings, the photocatalytic air purification unit 11 is formed as two layers.

[0110] The cavity 47 is located midway through the duct 41. The upstream portion of the duct 41 is laterally connected to an air inlet 47c located on the side of the cavity 47. A fan 45 is provided at the connection point in the duct 41 that connects to the air inlet 47c on the side of the cavity 47. The downstream portion of the duct 41 is connected to an exhaust portion 47d inside a partition member 46 on the bottom surface of the cavity 47. Furthermore, after the downstream portion of the duct 41 protrudes downward from the exhaust portion 47d on the bottom surface of the cavity 47, it temporarily winds upward along the cavity 47, making it higher than the middle portion of the photocatalytic air purifier 1. The outlet portion 53 at the end of the duct 41 is located at the upper part of the cavity 47, facing laterally (opposite to the photocatalytic air purifier 1). In this case, a grease filter is preferably provided at the connection point in the side of the cavity 47 that connects to the duct 41. For example, the grease filter may also be provided on the inlet side of the fan 45. The grease filter may also be provided on the outlet side of the fan 45.

[0111] Furthermore, in the accompanying drawings, the photocatalytic air purification unit 11 is positioned with the first connecting portion 16 facing downwards. However, it can also be configured with the entire unit reversed vertically so that the first connecting portion 16 faces upwards. In this case, the exhaust louvers 57 can be directly provided on the upper surface of the cavity 47. Alternatively, the downstream portion of the pipe 41 can be connected to the upper surface of the cavity 47, so that the outlet portion 53 faces laterally. Other detailed structures can be substantially the same as those in FIG. 9. In addition, the structure of this embodiment can be applied in a substantially similar manner to the structure in FIG. 9.

[0112] Figures 11 to 14 show modified examples of the structure that facilitate large-scale production of the photocatalytic air purifier 1 (vertical type photocatalytic air purifier) ​​of Figure 10. In this photocatalytic air purifier 1, an air inlet 47c is provided on one side of a large, architecturally shaped cavity 47, which is connected to or near the outlet portion 53 of the pipe 41. An exhaust portion 47d is located at a low position on the lower part of the other side of the cavity 47. An exhaust louver 57 is installed on the exhaust portion 47d.

[0113] Regarding the treated gas 5, the untreated gas before treatment enters the cavity 47 laterally from the side inlet 47c on one side, and the purified treated gas is released directly to the atmosphere from the exhaust outlet 47d at the lower part of the other side. However, as shown in Figure 10, the cavity 47 can also be located in the middle of the pipe 41.

[0114] Inside the cavity 47, a partition member 46 is provided between the air inlet 47c and the exhaust 47d, separating the air inlet 47c and the exhaust 47d vertically. The air inlet 47c and the exhaust 47d are arranged to be staggered in the vertical direction. That is, the interior of the cavity 47 is divided into upper and lower spaces 47a and 47b by a generally horizontal and flat plate-shaped partition member 46, which is located at the same or lower position as the lower part of the air inlet 47c and at the same or higher position as the upper part of the exhaust 47d. Moreover, the photocatalytic air purification unit 11 is arranged vertically in the upper (upstream) space 47a. The planar arrangement of the photocatalytic air purification unit 11 relative to the plate-shaped partition member 46 can be random. In this embodiment, in the upper (upstream) space 47a, a plurality of photocatalytic air purification units 11 are arranged laterally at intervals from the air inlet 47c side to the exhaust 47d side in a vertical configuration. Therefore, with respect to the photocatalytic air purification device 1, more photocatalytic air purification units 11 can be arranged more efficiently, and the purification capacity of the treated gas 5 is improved. Each photocatalytic air purification unit 11 can be a single layer in the vertical direction. Alternatively, each photocatalytic air purification unit 11 can also be connected in multiple layers in series vertically. In this embodiment, the photocatalytic air purification units 11 are arranged in a row of three in the horizontal direction with two overlapping layers. Furthermore, for example, four or more photocatalytic air purification units 11 with a structure of two or more overlapping layers can be arranged in the horizontal direction. According to this modified example of the photocatalytic air purification device 1, the partition member 46 is configured as a plate. Therefore, multiple photocatalytic air purification units 11 can be arranged on the plate surface. Thus, the photocatalytic air purification device 1 can be easily scaled up.

[0115] As described above, the upper and lower photocatalytic air purification units 11 can be integrally connected using a shared intermediate plate 14. Alternatively, they can be connected without using the shared intermediate plate 14. In this embodiment, the upper and lower photocatalytic air purification units 11 are arranged in a slightly separated state and connected to each other via a short cylindrical member 63. In this case, an end plate 13 having an opening as a first connecting portion 16 and another end plate 13 having an opening communicating with the first connecting portion are respectively provided between adjacent photocatalytic air purification units 11. Moreover, the openings of adjacent end plates 13 are connected by the short cylindrical member 63, so that the inner spaces 15 are interconnected. Furthermore, the cavity 47 can support each part of the photocatalytic air purification unit 11.

[0116] At this time, the photocatalytic air purification unit 11 can use the same structure as the embodiments described above, or it can be as shown in the modified example of FIG. 12. That is, in the photocatalytic air purification unit 11, a pair of mutually facing filter holding portions 13a to 13c are formed on the facing surfaces of a pair of (upper and lower) end plates 13 (FIG. 13). For example, the filter holding portions 13a to 13c can be formed as grooves. Moreover, the two ends of the cylindrical photocatalytic air purification filters 3a to 3c are respectively inserted between the pair of filter holding portions 13a to 13c, so that the photocatalytic air purification filters 3a to 3c can be clamped and held by the end plates 13. The shape and size of the filter holding portions 13a to 13c are formed to be the same as the ends of each photocatalytic air purification filter 3a to 3c, and the number of filter holding portions 13a to 13c is the same as that of the photocatalytic air purification filters 3a to 3c arranged concentrically. In this embodiment, the grooves of the filter holding portions 13a to 13c are circumferential grooves that extend continuously in the circumferential direction. Due to the formation of the circumferential grooves, the end plate 13 is formed as a plate-shaped body with a wall thickness greater than the depth of the circumferential grooves.

[0117] Furthermore, a dual chemical adsorption filter, such as a grease filter 61 and an activated carbon filter 62, can be provided on the outer side of the photocatalytic air purification unit 11. The outermost grease filter 61 removes oil from the treated gas 5, while the inner activated carbon filter 62 adsorbs and removes air pollutants from the treated gas 5. The grease filter 61 and activated carbon filter 62 can also function as the outer peripheral surface 17a of the housing 17 that surrounds the outer side of the photocatalytic air purification unit 11. The grease filter 61 and activated carbon filter 62 can also be configured, similar to the photocatalytic air purification filters 3a-3c, to be sandwiched between a pair of upper and lower end plates 13. However, as in this modified example, the grease filter 61 and activated carbon filter 62 can also be configured to only cover the outer side of the photocatalytic air purification unit 11, making it easy to install, remove, and replace relative to the photocatalytic air purification unit 11. Additionally, a frame member can be provided to hold the grease filter 61 and activated carbon filter 62. For example, the grease filter 61 and activated carbon filter 62 can be made of a porous material with continuous internal pores. In addition, the grease filter 61 and the activated carbon filter 62 can also be formed from other materials.

[0118] Furthermore, as shown in Figure 14, the elongated light source 4, formed by connecting multiple light-emitting elements 4a such as LEDs in a linear fashion as shown in Figure 8(a), can be housed in a transparent cylindrical member 4c such as a glass tube or heat-resistant glass tube, thereby forming a fluorescent lamp type (LED lamp). This allows for the standardization of the specifications and shape of the light source 4, forming a structure capable of using any type of fluorescent lamp, such as an ultraviolet lamp, an ultraviolet LED lamp, or a visible light LED lamp. Therefore, in the photocatalytic air purification unit 11, retaining holes 13d and 13e for embedding and retaining the fluorescent lamp type light source 4 are appropriately formed at the position where the light source 4 is located on the end plate 13. Depending on the situation, the retaining holes 13d and 13e can be formed as through holes, or at least one or both can be formed as bottom holes or recessed holes. When the retaining holes 13d and 13e are formed as bottom holes or recessed holes, the depth of the retaining holes 13d and 13e is within the thickness range of the end plate 13. For example, the aforementioned anti-fouling coating can be processed on the outer peripheral surface of a transparent cylindrical member 4c, which is a fluorescent lamp type light source 4.

[0119] At this time, regarding the support plate 4b on which the light-emitting elements 4a are mounted, both ends of the support plate 4b are supported and fixed by lamp holders 4d mounted at both ends of the cylindrical member 4c. Preferably, the fluorescent lamp type light source 4 has a rectifier substrate 4e at one end so that it can be powered from one side. The pins of the lamp holder 4d at one end of the cylindrical member 4c, the rectifier substrate 4e, and each light-emitting element 4a mounted on the support plate 4b are electrically connected to each other. For example, the pins on the power supply side are configured to be the upper end side relative to the vertically arranged photocatalytic air purification unit 11. In addition, contrary to the above, the pins on the power supply side of the light source 4 can also be arranged facing the lower end side. Regarding other detailed structures, they can be substantially the same as the structures of FIG9 and FIG10. In addition, the structure of this embodiment can be substantially similarly applied to the structures of FIG9 and FIG10.

[0120] Figures 15A to 20 show a larger-scale variation of the photocatalytic air purification device 1 (vertical type photocatalytic air purification device) shown in Figures 11 to 14. In this photocatalytic air purification device 1, as described above, a large, architectural cavity 47 contains rows of photocatalytic air purification units 11 arranged laterally from the air inlet 47c to the exhaust 47d. Furthermore, multiple rows of these laterally arranged units are spaced apart and arranged side-by-side in the depth direction (or width direction) of the cavity 47. For example, two rows of photocatalytic air purification units 11 may be arranged in the depth direction. Alternatively, three or more rows of photocatalytic air purification units 11 may be arranged in the depth direction. The number of rows is set according to the inflow or throughput of the processed gas 5. Thus, the purification capacity of the photocatalytic air purification device 1 for the processed gas 5 is improved by increasing the number of rows in the depth direction.

[0121] Viewed from above, the transverse rows of photocatalytic air purification units 11 in the depth direction can be arranged parallel to each other. In this case, the center-to-center spacing between adjacent photocatalytic air purification units 11 in the depth direction is equal. Alternatively, viewed from above, the transverse rows of photocatalytic air purification units 11 in the depth direction can also be arranged non-parallel to each other. In this embodiment, as shown in Figures 15A and 15B, viewed from above, the transverse rows of photocatalytic air purification units 11 arranged in two columns in the depth direction are inclined and arranged in a V-shape with a narrower inner side. In this case, the center-to-center spacing between adjacent photocatalytic air purification units 11 in the depth direction gradually narrows from the air inlet 47c side towards the exhaust 47d side. As a result, the processed gas 5 entering the cavity 47 from the air inlet 47c can directly contact the photocatalytic air purification unit 11 located on the inner side. Therefore, the photocatalytic air purification unit 11 located on the inner side can be used more effectively.

[0122] Furthermore, the architectural cavity 47 has an air inlet 47c and an exhaust 47d arranged at approximately the same position on both end faces, with their height and size roughly aligned. For this purpose, the horizontal plate-like partition member 46, where the photocatalytic air purification unit 11 is located, remains mostly plate-like, while a portion of the exhaust 47d side is formed as a vertically upward-facing longitudinal wall 46a reaching the upper surface of the cavity 47. This allows the downstream space 47b to connect with the exhaust 47d inside the cavity 47. Additionally, a work opening is provided on the side of the cavity 47. This work opening is used for the entry, exit, and maintenance of the photocatalytic air purification unit 11. An opening / closing door 47e is provided in the work opening. The cavity 47 is sealed by closing the opening / closing door 47e.

[0123] Furthermore, in this embodiment, the end plate 13 of the photocatalytic air purification unit 11 is formed with the following structure: The end plate 13 is made of a metal plate that is thinner than the end plates in Figures 12 and 13. Moreover, one (upper) end plate 13(A) of the upper layer (H) photocatalytic air purification unit 11 shown in Figure 17 and one (upper) end plate 13(B) of the lower layer (L) photocatalytic air purification unit 11 shown in Figure 18 are formed with slightly different shapes. Additionally, the other (lower) end plate 13(C) of the photocatalytic air purification unit 11 shown in Figure 20 is shared by both the upper layer (H) and the lower layer (L). That is, one end plate 13(A) of the upper layer (H) is formed in a disk shape. One end plate 13(B) of the lower layer (L) is formed in an annular shape. The other (lower) end plate 13(C) of the lower layer (L) is formed in an annular shape. Furthermore, in the case of photocatalytic air purification units 11 with three or more layers arranged vertically, a photocatalytic air purification unit 11 is added using one end plate 13 (B) of the lower layer (L) and another (lower side) end plate 13 (C) of the lower layer (L).

[0124] Furthermore, the filter holding portions 13a to 13c can be formed as protrusions (locking protrusions) projecting from the opposing surfaces of a pair of end plates 13, rather than grooves. The protrusions lock and hold the inner periphery of the ends of the photocatalytic air purifier filters 3a to 3c from the inside. Alternatively, the protrusions lock and hold the outer periphery of the ends of the photocatalytic air purifier filters 3a to 3c from the outside. The protrusions can be formed as annular protrusions extending continuously in the circumferential direction. Alternatively, the protrusions can be formed as discontinuous protrusions that are discontinuous in the circumferential direction. In this embodiment, the protrusions are discontinuous protrusions. At least three discontinuous protrusions are provided in the circumferential direction. Preferably, three or more discontinuous protrusions are provided at approximately equal positions in the circumferential direction. The number of discontinuous protrusions in the circumferential direction can be arbitrarily set according to the size of the photocatalytic air purifier filters 3a to 3c. Therefore, each photocatalytic air purifier filter 3a to 3c can be stably held in both the circumferential and radial directions.

[0125] At this time, the protrusion of the upper end plate 13(A) of the photocatalytic air purification unit 11 located on the upper side, which serves as the filter holding part 13a to 13c, is composed of a filter holding member 71 (Fig. 19) that is separate from the end plate 13. Similarly, the protrusion of the upper end plate 13(B) of the photocatalytic air purification unit 11 located on the lower side, which serves as the filter holding part 13a to 13c, is composed of a filter holding member 71 (Fig. 19) that is separate from the end plate 13. Moreover, the filter holding member 71 is fixed to the lower surface of the end plates 13(A) and 13(B) by fasteners such as bolts and nuts.

[0126] The filter holding member 71 is made of the same thin metal plate as the end plate 13. The filter holding member 71 has a ring portion 71a and a plurality of arms 71b. The ring portion 71a has an opening whose shape and size are substantially consistent with the opening that forms the first connecting portion 16. The plurality of arms 71b extend radially from the ring portion 71a. The ring portion 71a has a cutout portion 71c in the portion that interferes with the light source 4 located on the inner circumferential side. The cutout portion 71c functions to receive and retain the light source 4.

[0127] The number of arms 71b can be arbitrary, but preferably the same as the number of arms 71b arranged circumferentially with respect to the light source 4. In this embodiment, there are six arms 71b. Filter holding portions 13a to 13c are formed in the arms 71b. The filter holding members 71 are bent in the side-facing direction to form the filter holding portions 13a to 13c. Alternatively, the filter holding portions 13a to 13c are formed by mounting L-shaped metal parts onto the filter holding members 71.

[0128] Furthermore, without the filter holding member 71, the protrusions serving as filter holding parts 13a to 13c are directly mounted on the lower surfaces of end plates 13(A) and 13(B). Alternatively, for the other end plate 13(C) located on the lower side, the protrusions serving as filter holding parts 13a to 13c are directly mounted on its upper surface. However, for the other end plate 13(C), the protrusions serving as filter holding parts 13a to 13c can also be formed as separate filter holding members as described above, and the filter holding members are fixed to the upper surface of the other end plate 13(C) by bolts, nuts, or other fasteners.

[0129] Furthermore, the holding holes 13d and 13e of the light source 4 on one end plate 13(A) and 13(B) are through holes. The holding holes 13d and 13e of the light source 4 on the other end plate 13(C) are either bottomed holes or recessed holes. The bottomed holes or recessed holes can be formed by mounting a separately manufactured cup-shaped component 72 to the through hole portion. Alternatively, the bottomed holes or recessed holes can be integrally formed by stamping or other processes on the other end plate 13. Therefore, by simply inserting the fluorescent lamp-type light source 4 downwards through the upper through hole and fitting the lower end of the light source 4 into the lower bottomed hole or recessed hole, the light source 4 can be easily installed and removed from the photocatalytic air purification unit 11. Moreover, the photocatalytic air purification unit 11 does not need to be disassembled when installing or removing the light source 4.

[0130] Furthermore, in this embodiment, the distance between one end plate 13(A), 13(B) and the other end plate 13(C) is set to be shorter than that of the fluorescent lamp type light source 4. Moreover, at least the lamp holder 4d of the light source 4, having an upward-facing power supply side pin, protrudes upward from the holding holes 13d, 13e of the through-hole in the upper end plate 13. Therefore, the wiring 73 can be easily connected to the power supply side pin from outside the photocatalytic air purification unit 11.

[0131] At this time, fluorescent lamp-type or elongated light sources 4 can be positioned at different circumferential locations in the multiple intermediate spaces 23, 24, between the inner and outer layers. In this case, for example, the circumferential phases can be staggered by positioning the outer elongated light sources 4 in the middle of the circumferential direction between the inner elongated light sources 4. Thus, the light sources 4 are distributed at multiple circumferential locations, thereby achieving uniformity of light intensity in the circumferential direction.

[0132] Furthermore, the cylindrical member 63 connecting the upper (H) and lower (L) photocatalytic air purification units 11 can be separately arranged in the following manner. In this embodiment, a cylindrical plate 63a constituting the cylindrical member 63 is installed at the opening of the other end plate 13(C) located in the upper layer (H). Additionally, a cylindrical plate 63b constituting the cylindrical member 63 is installed at a communication opening provided in one end plate 13(B) located in the lower layer (L). Moreover, the cylindrical member 63 is formed by fitting the cylindrical plates 63a and 63b together in a circumferentially gapless manner. In this embodiment, the inner sides of the cylindrical plates 63a and 63b are fitted together. Conversely, the outer sides of the cylindrical plates 63a and 63b can also be fitted together.

[0133] Additionally, a spacer retaining member 74 can be provided between the upper and lower end plates 13. Multiple spacer retaining members 74 are provided circumferentially. In this embodiment, three spacer retaining members 74 are provided circumferentially. The spacer retaining member 74 can be a connecting member consisting of long bolts and nuts, etc. The length of the spacer retaining member 74 is approximately the same as that of the cylindrical photocatalytic air purifier filters 3a-3c. Bolt holes are provided on the end plates 13 at positions where the spacer retaining member 74 passes. Thus, the spacer retaining member 74 can maintain a constant spacing between the pair of end plates 13. Furthermore, the pair of end plates 13 can be connected and fixed using the connecting member. Therefore, it is not necessary to use the upper and lower end plates 13 to fasten the photocatalytic air purifier filters 3a-3c, preventing excessive load on the photocatalytic air purifier filters 3a-3c.

[0134] Furthermore, support and fixing members 75 to 77 can be provided in various parts of the photocatalytic air purification unit 11 to support and fix the photocatalytic air purification unit 11. Support and fixing members 75 to 77 can be provided between the cavity 47 and the photocatalytic air purification unit 11, or between the photocatalytic air purification units 11. For example, support and fixing member 75 can be provided between the upper layer (H) photocatalytic air purification unit 11 and the upper surface of the cavity 47. Support and fixing member 75 can be integrally provided with one end plate 13 (A) of the upper layer (H). Support and fixing member 75 can also be separately provided with one end plate 13 (A). In this embodiment, support and fixing member 75 is installed at the center of one end plate 13 (A). For example, support and fixing member 75 is a generally C-shaped member viewed from the side. Multiple support and fixing members 75 can be installed according to the height of the upper surface of the cavity 47. Additionally, although not shown, support and fixing members can be provided between the side of the photocatalytic air purification unit 11 and the side of the cavity 47.

[0135] A support and fixing member 76 can be disposed between the upper (H) photocatalytic air purification unit 11 and the lower (L) photocatalytic air purification unit 11. The length of the support and fixing member 76 is approximately equal to the vertical distance between one end plate 13 (B) of the lower (L) and the other end plate 13 (C) of the upper (H). The support and fixing member 76 can be integrally disposed with one end plate 13 (B) of the lower (L). The support and fixing member 75 can be separately disposed with one end plate 13 (B). The support and fixing member 76 is installed at the outer periphery of one end plate 13 (B). Multiple support and fixing members 76 are disposed approximately evenly in the circumferential direction. In this embodiment, three support and fixing members 76 are disposed. For example, the support and fixing member 76 is a member that is approximately C-shaped when viewed from the side.

[0136] A support and fixing member 77 can be disposed between the lower photocatalytic air purification unit 11 and the partition member 46 of the cavity 47. The length of the support and fixing member 77 is approximately equal to the vertical distance between the other end plate 13(C) of the lower layer (L) and the partition member 46. The support and fixing member 77 can be integrally disposed with the other end plate 13(C) of the lower layer (L). The support and fixing member 77 can also be separately disposed from the other end plate 13(C) of the lower layer (L). The support and fixing member 77 is installed at the outer periphery of the other end plate 13(C) of the lower layer (L). Multiple support and fixing members 77 are provided approximately evenly in the circumferential direction. In this embodiment, three support and fixing members 77 are provided. For example, the support and fixing member 77 is a member having a portion that is approximately L-shaped in side view. For example, the support and fixing member 77 can be integrally formed with the filter holding part 13b.

[0137] Furthermore, the same supporting and fixing components can be provided in the cases shown in Figures 9 to 14. Other detailed structures can be substantially the same as those in Figures 9 to 14. Additionally, the structure of this embodiment can be applied in a substantially similar manner to the structures shown in Figures 9 to 14. Moreover, all of the above-described photocatalytic air purification devices 1 have an airflow adjustment function that allows for arbitrary adjustment of the airflow of the processed gas 5. Furthermore, all of the above-described photocatalytic air purification devices 1 have a light intensity adjustment function that allows for arbitrary adjustment of the light intensity of the light source 4.

[0138] <Function>

[0139] The function of this embodiment will be explained below.

[0140] In the photocatalytic air purification device 1 using photocatalyst 2, the light source 4 is turned on, creating a state where the photocatalyst 2 is activated by light from the light source 4, and the treated gas 5 is passed through the photocatalytic air purification filters 3a to 3c. Thus, the photocatalytic air purification device 1, using the activated photocatalyst 2 carried by the photocatalytic air purification filters 3a to 3c, decomposes odor components and other components contained in the treated gas 5, purifying both the treated gas 5 and the air.

[0141] In the existing odor removal device using photocatalyst 2, a flat photocatalyst filter with a ceramic porous body as the substrate 6 is set in a way that blocks the flow of the treatment gas 5, so that the treatment gas 5 impacting the flat photocatalyst filter passes through in the vertical surface direction.

[0142] However, in this case, a dedicated passageway is required outside the photocatalyst filter to guide the process gas 5 to the flat-plate photocatalyst filter. Furthermore, the process gas 5 can only contact the photocatalyst 2 when passing through the flat-plate photocatalyst filter in the vertical direction. Therefore, during the process gas 5's journey from the process gas 5 through the passage to the photocatalyst filter, it is difficult for the process gas 5 to come into contact with the photocatalyst 2 (i.e., the opportunity for contact with the photocatalyst 2 is minimal).

[0143] Therefore, the photocatalytic air purifying filters 3a to 3c used in the photocatalytic air purifying device 1 of the embodiment are formed in a cylindrical shape. This allows the cylindrical photocatalytic air purifying filters 3a to 3c to serve as a passage for the processed gas 5. Since the photocatalyst 2 is present in the passage portion, the opportunity for the processed gas 5 to come into contact with the photocatalyst 2 is increased. Furthermore, a porous metal body 12 serves as the substrate 6 of the photocatalytic air purifying filters 3a to 3c. Therefore, the photocatalytic air purifying filters 3a to 3c using the porous metal body 12 can be more easily formed into a cylindrical shape.

[0144] <Effect>

[0145] According to this embodiment, the following effects can be obtained.

[0146] (Effect 1)

[0147] The photocatalytic air purifier filters 3a-3c, on which the photocatalyst 2 is supported, are formed into a cylindrical shape by using a metal porous body 12 on the substrate 6. Therefore, by using a metal porous body 1 on the substrate 6, the photocatalytic air purifier filters 3a-3c are less prone to breakage, lighter in weight, and easier to handle (compared to existing photocatalytic filters using a ceramic porous body as the substrate 6). Furthermore, the metal porous body 12 is easier to obtain and process, thus reducing costs.

[0148] By forming the photocatalytic air purifier filters 3a to 3c into a cylindrical shape, a novel shape for photocatalytic air purifier filters 3a to 3c, previously unseen, can be obtained. The cylindrical photocatalytic air purifier filters 3a to 3c possess multiple functions, including serving as a passageway for the processed gas 5 and as a permeable wall through which the processed gas 5 passes. Compared to flat-plate photocatalytic air purifier filters, the cylindrical photocatalytic air purifier filters 3a to 3c allow for a larger installation area within the same space. Furthermore, the cylindrical photocatalytic air purifier filters 3a to 3c can easily and arbitrarily increase their installation area simply by lengthening them as needed or connecting them in series.

[0149] The cylindrical photocatalytic air purifier filters 3a-3c can be formed as a single unit, with both ends blocked by end plates 13. Thus, by blocking only the two ends of the cylindrical photocatalytic air purifier filters 3a-3c, two passageways for the treated gas 5 (inner and outer) and a permeable wall can be simultaneously formed. Furthermore, multiple cylindrical photocatalytic air purifier filters 3a-3c can be configured. This increases the gas passageways and permeable wall, and allows for efficient arrangement of multiple cylindrical photocatalytic air purifier filters 3a-3c, effectively doubling the installation area of ​​the photocatalytic air purifier filters 3a-3c. Consequently, the contact opportunity between the treated gas 5 and the photocatalyst 2 is increased, correspondingly improving the air purification capacity, and enabling the simple manufacture of a small photocatalytic air purifier unit 11 with high air purification capabilities.

[0150] Furthermore, the inner space 15 of the innermost cylindrical photocatalytic air purifier filter 3a can be connected to the outside via a first connecting portion 16 formed on an end plate 13. Thus, a path can be formed between the inner space 15 and the outer space 18 of the outermost cylindrical photocatalytic air purifier filter 3b, through which the treated gas 5 sequentially passes through one or more photocatalytic air purifier filters 3a-3c.

[0151] At this time, one or more cylindrical photocatalytic air purification filters 3a-3c can be housed inside the housing 17. Preferably, a pair of end faces 17b and 17c are provided at both ends of the outer peripheral surface 17a of the housing 17. Moreover, one end face 17b may have a first connecting portion 16, and the other end face 17c or the outer peripheral surface 17a may have a second connecting portion 19. Thus, the photocatalytic air purification unit 11 is compactly integrated and easy to operate.

[0152] The second connecting portion 19 connects the exterior of the housing 17 to the space 18 outside the outermost cylindrical photocatalytic air purifier filter 3b. Preferably, the second connecting portion 19 is formed on the outer peripheral surface 17a of the housing 17, or on the end face 17b opposite to the first connecting portion 16 of the housing 17. This allows a path for the processed gas 5 to pass through the outer peripheral surface 17a or the end face 17b of the housing 17, connecting the exterior to the outer space 18.

[0153] (Effect 2)

[0154] The first connecting portion 16 can serve as the inlet 31 of the processed gas 5. The second connecting portion 19 becomes the outlet 32 ​​of the processed gas 5. Thus, the external processed gas 5 first enters the inner space 15 of the innermost cylindrical photocatalytic air purifier filter 3a from the first connecting portion 16 (inlet 31). The processed gas 5 passes sequentially through the cylindrical photocatalytic air purifier filters 3a to 3c, which are arranged in one or more layers, from the inner peripheral side to the outer peripheral side. Then, the processed gas 5 reaches the outside of the outermost cylindrical photocatalytic air purifier filter 3b (outer space 18). In the case of a housing 17, the processed gas reaches the outer space 18 between the outermost cylindrical photocatalytic air purifier filter 3b and the housing 17, passes through the outer space 18, and flows out of the housing 17 from the second connecting portion 19 (outlet 32). In the case of a housing 17 made of porous material 22, the processed gas 5 flows out to the outside in a state of diffused diffusion throughout the housing 17.

[0155] At this time, in the inner space 15, the processing gas 5 flows rapidly and straight from one end face 17b to the opposite end face 17c with minimal diffusion, impacting the other end face 17c and thus reducing its flow velocity. At this time, the portion of the processing gas 5 that comes into contact with the innermost cylindrical photocatalytic air purification filter 3a is purified by contact with the photocatalyst 2.

[0156] In the intermediate spaces 23 and 24, the processing gas 5, at a low flow rate, diffuses (returns) appropriately towards one end face 17b towards the outer periphery while sequentially passing through one or more cylindrical photocatalytic air purification filters 3a to 3c. When the processing gas 5 diffuses (returns) along the cylindrical photocatalytic air purification filters 3a to 3c, or when the processing gas 5 passes through the cylindrical photocatalytic air purification filters 3a to 3c, the processing gas 5 comes into contact with the photocatalyst 2 and is purified.

[0157] In the outer space 18, the processing gas 5 is guided to the second connecting part 19 at a low flow rate. At this time, the portion of the processing gas 5 that is in contact with the outermost cylindrical photocatalytic air purification filter 3b is purified by contact with the photocatalyst 2.

[0158] Therefore, the treated gas 5 as a whole comes into contact with the photocatalyst 2 carried on the cylindrical photocatalytic air purification filters 3a to 3c over a relatively large area, and is thus effectively purified.

[0159] Furthermore, as the processed gas 5 flows, the flow path cross-sectional area of ​​the inner space 15, the middle spaces 23 and 24, and the outer space 18 successively increases, thus minimizing the pressure loss of the processed gas 5. Moreover, the photocatalytic air purification unit 11 is configured with processing speed as the priority.

[0160] (Effect 3)

[0161] The second connecting portion 19 can serve as the inlet 31 of the processed gas 5. The first connecting portion 16 becomes the outlet 32 ​​of the processed gas 5. Thus, in the case of the housing 17, the external processed gas 5, which is introduced into the housing 17 from the second connecting portion 19 (inlet 31), enters the outer space 18 between the outermost cylindrical photocatalytic air purifier filter 3b and the housing 17. In the case of the housing 17 being made of porous material 22, the processed gas 5 enters from the entire circumference of the housing 17. The processed gas 5 in the outer space 18 passes sequentially from the outer periphery to the inner periphery through one or more cylindrical photocatalytic air purifier filters 3a to 3c, reaching the inner space 15 of the innermost cylindrical photocatalytic air purifier filter 3a. Furthermore, the processed gas 5 passes through the inner space 15 in the longitudinal direction and flows out to the outside (of the housing 17) in a concentrated state at the first connecting portion 16 (outlet 32).

[0162] At this time, in the outer space 18, for example in the case of Figure 6, the processing gas 5 diffuses circumferentially or in a circumferentially diffused state, flowing from the other end face 17c towards the opposite end face 17b at a low flow rate. Then, most of the processing gas 5 passes through the outermost cylindrical photocatalytic air purifying filter 3b approximately evenly throughout the entire area from the initial stage, with the remaining portion impacting the other end face 17c. Thus, the processing gas 5 can come into large-area contact with the photocatalyst 2 of the outermost cylindrical photocatalytic air purifying filter 3b and be purified efficiently.

[0163] In the intermediate spaces 23 and 24, the processing gas 5, in a state of diffusion covering almost the entire area and at a low flow rate, passes sequentially through one or more cylindrical photocatalytic air purification filters 3a to 3c toward the inner periphery. Thus, the processing gas 5 comes into large-area contact with the photocatalyst 2 in the cylindrical photocatalytic air purification filters 3a to 3c, and is effectively purified.

[0164] In the inner space 15, the processing gas 5 is guided towards the first connecting portion 16 at a low flow rate, and the flow rate increases slightly near the first connecting portion 16. At this time, the portion of the processing gas 5 that comes into contact with the innermost cylindrical photocatalytic air purifier filter 3a comes into contact with the photocatalyst 2 and is purified.

[0165] Therefore, the treated gas 5 spends time in relatively equal contact with the photocatalyst 2 carried in the cylindrical photocatalytic air purification filters 3a-3c at a low flow rate over approximately the entire area. Consequently, the effective usable area of ​​each photocatalytic air purification filter 3a-3c becomes larger, resulting in more efficient purification of the treated gas 5. Furthermore, the photocatalytic air purification unit 11 is configured with processing efficiency as a priority.

[0166] (Effect 4)

[0167] The photocatalytic air purification unit 11 is configured by combining one or more units to block the entire cross-section of the pipe 41 through which the treated gas 5 passes, thereby constituting the photocatalytic air purification device 1.

[0168] At this time, for example, the photocatalytic air purification device 1 can be configured such that one or more photocatalytic air purification units 11 are mounted on a partition member 46, which (directly) blocks the entire passage cross-section of the pipe 41. Alternatively, the photocatalytic air purification device 1 can be configured such that one or more photocatalytic air purification units 11 are arranged side-by-side and bundled together, (directly) inserted into the pipe 41 and blocking the entire passage cross-section. Furthermore, the photocatalytic air purification device 1 can be installed in a cavity 47 midway through the pipe 41 in the same manner as described above. Thus, the entire passage cross-section of the pipe 41 can be easily blocked, and all the treated gas 5 can be guided to the photocatalytic air purification device 1. In particular, by bundling the photocatalytic air purification units 11, more photocatalytic air purification units 11 can be efficiently installed in the pipe 41.

[0169] Therefore, even a single type of photocatalytic air purification unit 11 can accommodate pipes 41 of various sizes. As long as the passage section of the pipe 41 can be blocked, multiple types of photocatalytic air purification units 11 of different sizes and shapes can be appropriately combined and arranged side by side.

[0170] Furthermore, multiple photocatalytic air purification units 11 arranged in parallel and bundled together can be connected in series to form multiple layers. This increases the air purification capacity due to the increased number of layers.

[0171] (Effect 5)

[0172] The photocatalytic air purification unit 11 can be installed at least at any one of the inlet portion 51, intermediate portion 52, or outlet portion 53 of the duct 41. Therefore, by installing the photocatalytic air purification unit 11 at the inlet portion 51 of the duct 41 (individually distributed photocatalytic air purification device 1a), the photocatalytic air purification device 1 can be miniaturized, with multiple photocatalytic air purification devices 1 distributed and individually installed at each inlet portion 51 of the duct 41. This reduces the cost of each photocatalytic air purification unit 11, and simplifies maintenance and upkeep.

[0173] When the photocatalytic air purification unit 11 is placed in the middle section 52 of the duct 41 (medium-scale distributed photocatalytic air purification device 1b), the photocatalytic air purification device 1 can be miniaturized, for example, disposed in each system (or layer) of the duct 41. Therefore, it is possible to maintain and service the photocatalytic air purification unit 11 in each system of the duct 41.

[0174] When the photocatalytic air purification unit 11 is installed at the outlet portion 53 of the duct 41 (centralized photocatalytic air purification device 1c), the photocatalytic air purification device 1 can be enlarged and centrally located at the outlet portion 53 of the duct 41. Therefore, maintenance and upkeep of the photocatalytic air purification unit 11 can be performed all at once.

[0175] Explanation of reference numerals in the attached figures

[0176] 1: Photocatalytic air purification device; 2: Photocatalyst; 3: Photocatalytic air purification filter; 3a: Photocatalytic air purification filter; 3b: Photocatalytic air purification filter; 3c: Photocatalytic air purification filter; 5: Processed gas; 11: Photocatalytic air purification unit; 12: Porous metal body; 13: End plate; 15: Inner space; 16: First connecting part; 17: Shell; 17a: Outer peripheral surface; 17b: End face; 17c: End face; 18: Outer space; 19: Second connecting part; 31: Inlet; 32: Outlet; 41: Pipe; 51: Inlet section; 52: Middle section; 53: Outlet section.

[0177] Cross-referencing of related applications

[0178] This application claims priority based on Japan Patent Application No. 2022-008107 filed with the Japan Patent Office on January 21, 2022, the entire disclosure of which is incorporated herein by reference.

Claims

1. A photocatalytic air purification unit, characterized in that, A photocatalytic air purifier filter, formed in a cylindrical shape, is a porous metal body with irregular, three-dimensional continuous pores inside, carrying a photocatalyst. Multiple cylindrical photocatalytic air purifier filters are arranged in a multi-layered configuration, with circumferentially extending intermediate spaces between adjacent filters. Both ends are blocked by end plates. The innermost cylindrical photocatalytic air purifier filter has its innermost space connected to the outside by a first connecting portion formed in one of the end plates. The intermediate space is connected, and light sources are arranged at multiple points in the circumferential direction. The light sources irradiate light onto both the inner and outer cylindrical photocatalytic air purifier filters forming the intermediate space. The ultraviolet transmittance of the metal porous body is greater than 0% and less than 8%. The photocatalyst is uniformly dispersed in continuous pores on the surface, back, and interior of the metal porous body. The light sources activate the photocatalyst on the surface, back, and interior of the two cylindrical photocatalytic air purifier filters forming the intermediate space.

2. The photocatalytic air purification unit according to claim 1, characterized in that, The first connecting part is the inlet for processing gas.

3. The photocatalytic air purification unit according to claim 1, characterized in that, The first connecting part is the outlet part for the processed gas.

4. A photocatalytic air purification device, characterized in that, One or more photocatalytic air purification units as described in claim 1 are combined to block the entire cross-section of the pipe through which the treated gas flows.

5. The photocatalytic air purification device according to claim 4, characterized in that, The photocatalytic air purification unit is installed at least at any one of the inlet, middle, and outlet sections of the duct.

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