Photoreactor module

Abstract

To provide a photoreactor module that promotes photoreaction.SOLUTION: A photoreactor module according to one embodiment of the present invention includes: a photoreactor including a light-transmissive pipe and granules, which are stored inside the pipe and include a light guide material, where fluid circulates inside the pipe; an outer cylinder surrounding the photoreactor from the outside in the radial direction of the pipe; and a light source that is disposed on the inner surface of the outer cylinder and directs light toward the granules. The inner surface of the outer cylinder reflects light from the light source.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a photoreactor module.

Background Art

[0002] Conventionally, there is known a photoreactor that irradiates a photocatalyst-coated photocatalyst body with light and passes a treatment object such as a gas or a liquid through it to decompose organic substances contained in the treatment object by a photocatalytic reaction.

[0003] For example, Patent Document 1 discloses a photocatalyst purification device including an excitation light incident portion for incident excitation light, a plurality of hollow tubes provided in the longitudinal direction of the device, being transparent to the excitation light and having the same inner diameter, and a photocatalyst layer formed on at least the inner peripheral surface of each hollow tube and excited by the excitation light. Further, sunlight is irradiated from above the device as the excitation light, and a reflector is provided on the lower side of the device to enhance the purification ability (photocatalytic reaction) of the entire device.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when irradiating excitation light from the outside of the device like the above-described photocatalyst purification device of Patent Document 1, the excitation light is attenuated by scattering during propagation in the air. Further, in the above-described photocatalyst purification device of Patent Document 1, since a reflector is provided only on the lower side of the device, the light reflected by the reflector may leak to the outside, and there is a possibility that a sufficient photocatalytic reaction cannot be obtained.

[0006] In view of the above points, an aspect of the present invention aims to provide a photoreactor module that promotes a photoreaction such as a photocatalytic reaction. [Means for solving the problem]

[0007] A photoreactor module according to one aspect of the present invention comprises a light-transmitting tube, a plurality of granular bodies containing a light-guiding material housed inside the tube, a photoreactor through which a fluid flows inside the tube, an outer cylinder surrounding the photoreactor from the radially outer side of the tube, and a light source disposed on the inner circumferential surface of the outer cylinder for irradiating light toward the granular bodies, wherein the inner circumferential surface of the outer cylinder reflects the light from the light source. [Effects of the Invention]

[0008] According to one aspect of the present invention, a photoreactor module that promotes photoreactions can be provided. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view of a photoreactor module according to one embodiment. [Figure 2] This is a cross-sectional view II in Figure 1. [Figure 3] This is an enlarged cross-sectional view of a key part of a photoreactor module according to one embodiment. [Figure 4] This is a schematic diagram illustrating the relationship between the inner surface of the outer cylinder and the light emitted from the light source. [Figure 5] This figure shows the relationship between the shortest distance between the outer surface of the pipe and the inner surface of the outer cylinder, and the amount of oil and grease decomposition with respect to the pipe thickness. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. For the sake of easier understanding of the description, the same reference numerals are used for identical components in each drawing, and redundant explanations may be omitted.

[0011] This document describes a photoreactor module based on one embodiment of the present invention.

[0012] Figure 1 is a perspective view of a photoreactor module 100 according to one embodiment, and Figure 2 is a cross-sectional view of Figure 1 II. As shown in Figures 1 and 2, a photoreactor module 100 according to one embodiment of the present invention comprises a photoreactor 1, a cylindrical outer tube 4, and a light source 5. The photoreactor module 100 also has an inlet at one end through which a fluid F flows in and an outlet at the other end through which the fluid F flows out, and processes the flowing fluid F by a photoreaction (photochemical reaction) such as a photocatalytic reaction. The photoreactor module 100 may further include a cooling mechanism 30 on the outside of the tube 2 for cooling the light source 5. The cooling mechanism 30 may be air-cooled or water-cooled. If the cooling mechanism 30 is air-cooled, it may have, for example, an air-cooled heat sink 6 and a cooling fan 7. The cooling fan 7 can be attached, for example, to one end of the photoreactor 1 via a base 11. In the case of a water-cooled system, the cooling mechanism 30 may include a water-cooled heatsink and a radiator.

[0013] The inlet end of the photoreactor 1 is provided with a flange 9 and a cap 8 that engages with the flange 9 and closes the opening. The cap 8 has a connection port 81 that penetrates the side of the cap 8. A pipe for circulating fluid F is connected to the connection port 81, allowing fluid F to flow into the photoreactor 1 from the connection port 81. Similarly, by providing a flange 9 and a cap 8 at the outlet end of the photoreactor 1, fluid F can be discharged to the outside of the photoreactor 1 from the connection port 81 that penetrates the side of the cap 8.

[0014] Figure 3 is an enlarged cross-sectional view of a key part of a photoreactor module 100 according to one embodiment. As shown in Figure 3, the photoreactor 1 has a light-transmitting tube 2 and a plurality of granular bodies 3 containing a light-guiding material housed inside the tube 2, and a fluid F containing, for example, harmful substances, organic matter, etc., as the material to be processed flows through the tube 2. There are no particular restrictions on the fluid F flowing inside the tube 2, and it may be a liquid or a gas. Examples of liquids include groundwater, tap water, wastewater, drinking water, reactants (substances before photoreaction), etc.

[0015] The cross-sectional shape perpendicular to the central axis 10 of the pipe 2 (more specifically, the cross-sectional shape of the inner surface of the pipe 2) is circular in the examples shown in Figures 1 to 3, but is not limited to this; for example, it can be elliptical or polygonal (hexagon, pentagon, quadrilateral, triangle, etc.). The cross-sectional shape perpendicular to the central axis 10 of the pipe 2 may also be hexagonal. If the cross-sectional shape perpendicular to the central axis 10 of the pipe 2 is hexagonal, the granular material 3 contained inside the pipe 2 will have a hexagonal close-packed structure. Therefore, the contact areas between the inner surface of the pipe 2 and the granular material 3 can be formed regularly, and the fusion surface 15 between the inner surface of the pipe 2 and the granular material 3, which will be described later, can be formed regularly. Thus, the optical axis 53 of the light source 5 can be easily aligned with the position of the fusion surface 15, and the illuminance across the entire fusion surface 15 can be improved.

[0016] The material constituting the tube 2 can be any light-guiding material that transmits light irradiated from the light source 5. For example, heat-resistant glass such as borosilicate glass or soda glass can be used. For example, when titanium dioxide (TiO2) is used as the photocatalyst, since titanium dioxide shows good absorption for wavelengths of 400 nm or less, the light source 5 is preferably a UV-A (A-region ultraviolet, or long-wavelength ultraviolet) LED (Light Emitting Diode) with an excitation wavelength of 365 nm. Therefore, when titanium dioxide is used as the photocatalyst, the material constituting the tube 2 is preferably borosilicate glass that shows good transmittance for light with a wavelength of 365 nm.

[0017] The inner diameter L2 of tube 2 is not particularly limited, and any inner diameter can be selected to minimize the overall pressure loss of the photoreactor module 100. For example, the inner diameter L2 of tube 2 can be 6 mm to 400 mm. An inner diameter L2 of 6 mm or more is suitable for accommodating and fusing general-purpose granular materials 3 with particle sizes of 2 mm to 20 mm. An inner diameter L2 of 400 mm or less is suitable for limiting the number of granular materials 3 to be fused and connected to a range that suppresses light attenuation. Note that the inner diameter of tube 2 refers to the maximum inner diameter passing through the center of the cross-sectional shape perpendicular to the central axis 10 of tube 2 if the cross-sectional shape perpendicular to the central axis 10 of tube 2 is not circular, and refers to the distance between opposite sides (distance between opposite sides) if the cross-sectional shape perpendicular to the central axis 10 of tube 2 is hexagonal.

[0018] The thickness L3 of the tube 2 is not particularly limited, but for example, it can be 15 mm or less. By setting the thickness L3 of the tube 2 to 15 mm or less, a light transmittance sufficient for the photoreaction can be obtained, and the photoreaction can be promoted.

[0019] The shape of the granule 3 is not particularly limited, but it is preferably spherical, and it is preferable that the particle diameters of the plurality of granules 3 are the same. Thereby, the photoreactor module 100 can exhibit high homogeneity and stable processing ability.

[0020] The particle diameter of the granule 3 is not particularly limited, but is preferably 2 mm to 20 mm, and more preferably 3 mm to 10 mm. By setting the particle diameter of the granule 3 to 2 mm to 20 mm, the attenuation of light within the granule 3 can be suppressed, and the photoreaction can be further promoted. Further, by setting the particle diameter of the granule 3 to 3 mm to 10 mm, the surface area can be increased to further promote the photoreaction, and the heat transfer property during fusion is improved, and the fusion surface 15 can be easily formed.

[0021] The material constituting the granule 3 may be a light guide material that transmits the light irradiated from the light source 5, and the same material as that of the tube 2 can be used. For example, when titanium dioxide is used as the photocatalyst, since titanium dioxide exhibits good absorption for wavelengths of 400 nm or less, the light source 5 is preferably a UV-A LED with an excitation wavelength of 365 nm. Therefore, when titanium dioxide is used as the photocatalyst, the material constituting the granule 3 is preferably borosilicate glass that exhibits good transmittance for light with a wavelength of 365 nm.

[0022] As shown in Figure 3, the photoreactor 1 has fused surfaces 15 where the granules 3 are fused together at the point of contact between the granules 3. The photoreactor 1 also has fused surfaces 15 where the inner surface of the tube 2 is fused to the granules 3 at the point of contact between the inner surface of the tube 2 and the granules 3. These fused surfaces 15 can be formed by heating the tube 2, which contains multiple granules 3, at a temperature above the melting point of the material constituting the granules 3. The portion of the tube 2 where the inner surface and the granules 3 are not in contact is referred to as a non-fused surface 16 where the inner surface of the tube 2 and the granules 3 are not fused together. In other words, the photoreactor 1 has fused surfaces 15 where the inner surface of the tube 2 and the granules 3 are fused together, and non-fused surfaces 16 where the inner surface of the tube 2 and the granules 3 are not fused together.

[0023] The photoreactor 1, having a fusion surface 15, can guide light irradiated from the light source 5 into the interior of the photoreactor 1 via the fusion surface 15 between the inner surface of the tube 2 and the granules 3, and the fusion surfaces 15 between the granules 3 themselves. In other words, the fusion surface 15 between the inner surface of the tube 2 and the granules 3, and the fusion surfaces 15 between the granules 3 themselves, constitute a light guide path C for the light irradiated from the light source 5.

[0024] Preferably, the fusion surface 15 between the inner circumferential surface of the tube 2 and the granular material 3 is formed in a direction parallel to the central axis 10 of the tube 2, with 10 or fewer layers. This suppresses the attenuation of light within the granular material 3 and further promotes the photoreaction. The particle size of the granular material 3 can be selected such that the fusion surface 15 between the inner circumferential surface of the tube 2 and the granular material 3 has 10 or fewer layers in a direction parallel to the central axis 10 of the tube 2.

[0025] From the viewpoint of forming the fused surface 15, it is preferable that the melting point of the material constituting the tube 2 is higher than the melting point of the material constituting the granules 3. Specifically, for example, heat-resistant glass such as borosilicate glass can be used for the material constituting the tube 2, and soda glass can be used for the material constituting the granules 3. This makes it possible to form the fused surface 15 without deforming the tube 2 by heat when heated to a temperature above the melting point of the material constituting the granules 3. The heating temperature when forming the fused surface 15 is preferably above the melting point of the material constituting the granules 3 and below the melting point of the material constituting the tube 2. However, if the melting points of the material constituting the granules 3 and the material constituting the tube 2 are equal, the granules 3 and the inner surface of the tube 2 may be appropriately fused by a sequential local heating method.

[0026] It is preferable that a photocatalytic layer 31 is provided on the surface of the granules 3. The photocatalyst constituting the photocatalytic layer 31 can be selected according to the material to be treated, and examples include titanium dioxide, zinc oxide, bismuth vanadate (BiVO4), etc. When the photocatalyst constituting the photocatalytic layer 31 is titanium dioxide, effects such as air purification, water purification, deodorization, sterilization, and antifouling can be obtained through oxidation and decomposition reactions. By providing the photocatalytic layer 31 on the surface of the granules 3, the contact area between the fluid F, which is the material to be treated, and the photocatalyst can be increased, and at the same time, the area of ​​light irradiation on the photocatalyst can be increased, thereby promoting the photocatalytic reaction. The photocatalytic layer 31 may be provided on the surface of the granules 3 and on the inner circumferential surface of the pipe 2.

[0027] The light source 5 is positioned on the outside of the tube 2, specifically on the inner surface of the outer cylinder 4, and irradiates light toward the granules 3. The light irradiated from the light source 5 enters the outer surface of the tube 2 and is transmitted to the inner surface of the tube 2. Any light source can be selected as the light source 5 depending on the photocatalyst, such as a UV light (black light), xenon lamp, or excimer lamp. Specifically, a UV-A LED can be used as a UV light. For example, when titanium dioxide is used as the photocatalyst, since titanium dioxide shows good absorption for wavelengths of 400 nm or less, a UV-A LED with an excitation wavelength of 365 nm is preferred as the light source 5.

[0028] The number of light sources 5 is not particularly limited and can be determined from the total power consumption of the photoreactor module 100 and the amount of heat dissipated by the light sources 5. The light sources 5, for example, consist of multiple light-emitting elements 51 (e.g., LED elements) provided on the surface of a substrate 52 that is directly or indirectly attached to the inner circumferential surface of the outer cylinder 4. The light sources 5 may also include multiple light-emitting elements 51 arranged so that their optical axes 53 are aligned in a direction perpendicular to the surface of the substrate 52.

[0029] The light sources 5 may be arranged in a row on the surface of the outer cylinder 4 facing the tube 2 (the inner circumferential surface of the outer cylinder 4) in a direction parallel to or perpendicular to the central axis 10 of the tube 2. The light sources 5 may also be light-emitting units arranged in a line at predetermined intervals on the substrate 52. For example, six light-emitting units, each having multiple light-emitting elements 51 arranged parallel to the central axis 10 of the tube 2, may be arranged at equal intervals in the circumferential direction on the inner circumferential surface of the outer cylinder 4. Alternatively, six light-emitting units, each having multiple light-emitting elements 51 arranged perpendicular to the central axis 10 of the tube 2, may be arranged at equal intervals in the circumferential direction on the inner circumferential surface of the outer cylinder 4. When the cross-sectional shape perpendicular to the central axis 10 of the tube 2 is hexagonal, as described above, the fusion surface 15 between the inner circumferential surface of the tube 2 and the granules 3 is formed in a straight line along the circumferential direction of the tube 2 (the direction perpendicular to the central axis 10 of the tube 2). Therefore, it is preferable that multiple light sources 5 are arranged in a line on the surface of the outer cylinder 4 facing the tube 2 (the inner circumferential surface of the outer cylinder 4) in a direction perpendicular to the central axis 10 of the tube 2.

[0030] Preferably, the optical axis 53 of the light source 5 is positioned perpendicular to the fusion surface 15 between the inner circumferential surface of the tube 2 and the granular material 3. In other words, it is preferable that the optical axis 53 of the light source 5 is perpendicular to the fusion surface 15. By having the optical axis 53 of the light source 5 perpendicular to the fusion surface 15, the illuminance at the fusion surface 15 can be made greater than the illuminance at the non-fusion surface 16. Therefore, the light irradiated from the light source 5 can be guided from the fusion surface 15 between the inner circumferential surface of the tube 2 and the granular material 3 along the light guide path C to the interior of the photoreactor 1. Furthermore, if a photocatalytic layer 31 is provided on the surface of the granular material 3, the amount of light received by the photocatalytic layer 31 on the surface of the granular material 3 can be increased. As a result, the photoreactor module 100 of this embodiment can promote photoreactions such as photocatalytic reactions.

[0031] The outer cylinder 4 surrounds the photoreactor 1 from the radial outside of the tube 2. In other words, the photoreactor 1 is located inside the outer cylinder 4. Preferably, the outer cylinder 4 is located coaxially with the central axis 10 of the tube 2. In this case, the central axis 10 can also be said to be the central axis of the outer cylinder 4. Hereafter, the central axis 10 of the tube 2 will also be used as the central axis of the outer cylinder 4.

[0032] The inner surface of the outer cylinder 4 reflects the light from the light source 5. Figure 4 is a schematic diagram illustrating the relationship between the inner surface of the outer cylinder 4 and the light emitted from the light source 5. In Figure 4, the photocatalytic layer 31 is omitted. The light emitted from the light source 5 consists of light that directly enters the photoreactor 1 and light that travels in a straight line outside the photoreactor 1. The light that travels in a straight line outside the photoreactor 1 is reflected by the inner surface of the outer cylinder 4 and enters the photoreactor 1. In addition, light scattered outside the photoreactor 1 is also reflected by the inner surface of the outer cylinder 4 and enters the photoreactor 1. Therefore, by the inner surface of the outer cylinder 4 reflecting the light from the light source 5, more light from outside the photoreactor 1 can be guided into the photoreactor 1, thereby promoting photoreactions such as photocatalytic reactions.

[0033] In Figure 3, it is preferable to set the shortest distance L1 between the outer surface of the tube 2 of the photoreactor 1 and the inner surface of the outer cylinder 4 to be 40 mm or less when the outer diameter of the tube 2 is 80 mm to 400 mm. By setting the shortest distance L1 to 40 mm or less, scattering and attenuation in the air between the light source 5 and the photoreactor 1 can be suppressed, thereby promoting photoreactions such as photocatalytic reactions.

[0034] The inner surface of the outer cylinder 4 may be made of a reflective material or may be coated with a reflective material. The reflective material is not particularly limited, but examples include metals such as aluminum and polytetrafluoroethylene. Among these, the reflective material is preferably a metal. Because the reflective material is a metal, degradation can be suppressed even when the light irradiated from the light source 5 has a short wavelength (for example, 280 nm or less).

[0035] The inner surface of the outer cylinder 4 preferably has a reflectivity of 80% or more to light from the light source 5, and the higher the reflectivity, the better. A reflectivity of 80% or more to light from the light source 5 of the inner surface of the outer cylinder 4 allows more light from outside the photoreactor 1 to be reflected and guided into the photoreactor 1, thereby promoting photoreactions such as photocatalytic reactions. The inner surface of the outer cylinder 4 may be a mirror surface or a scattering surface.

[0036] The cross-sectional shape perpendicular to the central axis 10 of the outer cylinder 4 (more specifically, the cross-sectional shape of the inner surface of the outer cylinder 4) can be circular, elliptical, or polygonal (hexagon, pentagon, quadrilateral, triangle, etc.). Preferably, the cross-sectional shape perpendicular to the central axis 10 of the outer cylinder 4 is the same as the cross-sectional shape perpendicular to the central axis 10 of the tube 2. This ensures that the distance between the tube 2 and the outer cylinder 4 is uniform in the circumferential direction, allowing the light from the light source 5, positioned on the inner surface of the tube 2, to be uniformly irradiated onto the photoreactor 1. Therefore, the photoreactor module 100 can exhibit highly homogeneous and stable processing capabilities. Furthermore, it is preferable that the cross-sectional shape perpendicular to the central axis 10 of the outer cylinder 4 be a polygon such as a hexagon, pentagon, quadrilateral, or triangle. This allows the mounting plane of the light source 5 (for example, the back surface of the substrate 52) to be placed in close contact with the inner surface of the outer cylinder 4, enabling the heat from the light source 5 to be conducted to the outer cylinder 4 and dissipated from the outer cylinder 4. Therefore, it is possible to suppress the temperature of the photoreactor 1 from rising excessively due to the heat of the light source 5, and also to suppress damage or deterioration of the light source 5 due to heat.

[0037] There are no particular restrictions on the inner diameter of the outer cylinder 4, and any size can be selected depending on the material constituting the tube 2, the outer diameter of the tube 2, and the excitation wavelength of the light source 5. The inner diameter of the outer cylinder 4 refers to the maximum inner diameter passing through the center of the cross-sectional shape perpendicular to the central axis 10 of the outer cylinder 4 if the cross-sectional shape perpendicular to the central axis 10 of the outer cylinder 4 is not circular, and refers to the distance between opposite sides if the cross-sectional shape perpendicular to the central axis 10 of the outer cylinder 4 is hexagonal.

[0038] Next, a method for manufacturing the photoreactor module 100 will be described.

[0039] First, a tube 2 and numerous granules 3 are prepared, along with a photocatalytic solution for forming the photocatalytic layer 31. The photocatalytic solution may, for example, mainly consist of titanium dioxide and may contain necessary binders. Next, the tube 2 is erected on a substrate jig, and the granules 3 are poured into the tube 2 through the opening at its upper end to fill it. Then, the tube 2 filled with granules 3 is placed inside a heating furnace heated by a heater, and heated for a predetermined heating time Z under a heating temperature T [°C]. As a result, the surfaces of the tube 2 and granules 3 melt at the heating temperature T [°C], and the contact points between the tube 2 and granules 3, and the contact points between the granules 3 themselves, are welded together, creating a fused surface 15 with a predetermined area. In this case, if the heating temperature T [°C] is too low, insufficient melting occurs, and a sufficient and good fused surface 15 cannot be obtained. Also, if the heating temperature T [°C] is too high, excessive melting occurs, resulting in an unsatisfactory internal shape and a narrowed flow path. Therefore, it is desirable to set the optimal values ​​for the heating temperature T [°C] and heating time Z through experiments or other means. Preferably, the heating temperature T [°C] is above the melting point of the material constituting the granules 3 and below the melting point of the material constituting the tube 2. For example, the heating temperature T [°C] can be 600 to 700 [°C]. This provides a continuous light guide path C between the tube 2 and the granules 3 via the fusion surface 15. After the heating time Z has elapsed, the tube 2 is removed from the heating furnace and cooled to room temperature by natural cooling.

[0040] Next, the photocatalytic solution is injected from the upper opening of the tube 2, filling the inside of the tube 2 with the photocatalytic solution (step a). At this time, vibration or other means may be applied as needed to allow the photocatalytic solution to penetrate into the gaps between the granules 3. After a predetermined time has elapsed, the photocatalytic solution is discharged from the tube 2 (step b). Then, the tube 2 containing the granules 3 after the photocatalytic solution has been discharged is dried or calcined (step c). This allows a photocatalytic layer 31 made of titanium dioxide to be formed on the surface of the granules 3, excluding the fused surface 15, and on the inner circumferential surface of the tube 2. By this method, a uniform photocatalytic layer 31 can be easily formed on the surface of the granules 3 and on the inner circumferential surface of the tube 2. If necessary, the film thickness (layer thickness) of the photocatalytic layer 31 can be adjusted by repeating steps a to c. After this, the substrate jig is removed, and finishing work such as removing any unnecessary photocatalytic layer 31 adhering to the end face and outer surface of the tube 2 is performed, and further inspections such as light guidance are carried out to obtain the photoreactor 1. If the photocatalytic layer 31 is not provided on the surface of the granules 3 or on the inner circumference of the tube 2, steps a to c are unnecessary.

[0041] The resulting photoreactor 1 can be configured as a photoreactor module 100 by attaching flanges 9 and caps 8 to the openings at both ends. Then, a pipe for circulating fluid F is connected to the connection port 81 of the cap 8. This results in a photoreactor module 100 in which one end of the pipe 2 becomes the inlet for fluid F and the other end becomes the outlet for fluid F. [Examples]

[0042] The embodiments will be described in more detail below with reference to examples and comparative examples, but the embodiments are not limited to these examples.

[0043] (Example 1) A photoreactor was obtained in which multiple granules of the same material with a particle size of 8 mm were placed inside a cylindrical tube made of borosilicate glass, with an inner diameter of 80 mm and a height of 40 mm, and fused together. By coating and baking anatase-type TiO2, a TiO2 photocatalytic layer was formed on the inner surface of the tube and on the surface of the granules.

[0044] A 40mm high aluminum cylinder (85% reflectivity) was installed as an outer casing on the radially outer side of the photoreactor. Four UV-A LEDs (365nm, 540mW) were fixed at a height of 20mm on the inner surface of the aluminum cylinder at 90° intervals to obtain the photoreactor module of Example 1. Each reactor module was obtained by varying the dimensional conditions of the shortest distance L1 between the outer surface of the borosilicate glass tube and the inner surface of the aluminum cylinder, and the thickness L3 of the tube.

[0045] (Comparative Example 1) A photoreactor module for Comparative Example 1 was obtained in the same manner as in Example 1, except that the outer cylinder of Example 1 was not used.

[0046] [Evaluation of oil and fat decomposition performance] As the water-soluble oil-containing fluid to be processed in the photoreactor module, milk prepared with water to a solid content of 10% was used. With the milk sealed in each photoreactor in Example 1 and Comparative Example 1, the photoreactors were irradiated with LEDs to conduct a photocatalytic oil decomposition test. The amount of oil in the milk after 4.0 hours of UV-A LED irradiation was quantified by TOC (Total Organic Carbon Dioxide), and the oil decomposition performance was evaluated. A higher oil decomposition performance indicates that the photocatalytic reaction is more accelerated.

[0047] The amount of oil and fat decomposition and the amount of light received by the photoreactor modules in Example 1 and Comparative Example 1 are shown below (thickness L3 of the borosilicate glass tube = 5 mm (Example 1 and Comparative Example 1). The shortest distance L1 = 20 mm between the outer surface of the borosilicate glass tube and the inner surface of the aluminum cylinder (Example 1)). Note that the amount of light received is a calculated value obtained by illuminance analysis. Example 1: Fat and oil decomposition amount 28.3 mg / L (light received amount 5.57 kJ) Comparative example 1: Oil decomposition amount 23.6 mg / L (light received amount 4.65 kJ)

[0048] The amount of oil and fat decomposition in the photoreactor module of Example 1 was 19.9% ​​higher than that of the photoreactor module of Comparative Example 1. Furthermore, the amount of light received by the photoreactor of Example 1 was greater than that received by the photoreactor of Comparative Example 1. Therefore, it was confirmed that the photoreactor module of Example 1 has higher oil and fat decomposition performance than Comparative Example 1. In other words, it was confirmed that the photoreactor module of Example 1 promotes the photocatalytic reaction.

[0049] Furthermore, the amount of grease decomposition for each photoreactor module in Example 1, with varying dimensional conditions for the shortest distance L1 and thickness L3, was plotted and a graph was created. Figure 5 shows the relationship between the amount of grease decomposition and the shortest distance between the outer surface of the tube and the inner surface of the outer cylinder, and the thickness of the tube. As shown in Figure 5, it was confirmed that the amount of grease decomposition decreased significantly when L1 > 40 mm. In addition, the amount of light received by the photoreactor was greater at the shortest distance L1 = 20 mm (amount of light received 5.57 kJ) than at the shortest distance L1 = 60 mm (amount of light received 4.09 kJ) when the tube thickness L3 = 5 mm, and greater at the shortest distance L1 = 20 mm (amount of light received 4.25 kJ) than at the shortest distance L1 = 60 mm (amount of light received 3.53 kJ) when the tube thickness L3 = 20 mm. This is thought to be because the attenuation of light due to scattering in the air increased as the shortest distance L1 increased. Another possible cause is the increase in light that does not directly enter the tube but is reflected once by the outer tube before entering it. Therefore, it is desirable to arrange the tubes so that L1 ≤ 40 mm.

[0050] As described above, embodiments have been explained, but these embodiments are presented as examples only, and the present invention is not limited by these embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, and modifications are possible without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of symbols]

[0051] 1. Photoreactor 2 tubes 3 grains 31 Photocatalyst layer 4. Outer cylinder 5 light source 51 Light-emitting element 52 circuit boards 53 Optical axis 6. Air-cooled heatsink 7 Cooling fan 8 caps 81 connection ports 9 flanges 10 Center axis 11 Pedestal 15 Fusion surface 16 Non-fused surface 30 Cooling mechanism 100 Photoreactor Modules

Claims

1. A photoreactor comprising a light-transmitting tube and a plurality of granular bodies containing a light-guiding material housed inside the tube, through which a fluid flows inside the tube, The photoreactor is surrounded by an outer cylinder from the radially outer side of the tube, The outer cylinder is provided with a light source that is positioned on the inner circumferential surface and irradiates light toward the granules, The inner circumferential surface of the outer cylinder reflects the light from the light source, The photoreactor has a fused surface where the inner surface of the tube and the granular material are fused together, and a non-fused surface where the inner surface of the tube and the granular material are not fused together. The cross-sectional shape perpendicular to the central axis of the aforementioned pipe is hexagonal. The fusion surfaces are formed in a straight line along a direction perpendicular to the central axis of the pipe, The aforementioned light source is a photoreactor module in which multiple light sources are arranged in a line perpendicular to the central axis of the tube.

2. The photoreactor module according to claim 1, wherein a photocatalytic layer is provided on the surface of the granules.

3. The photoreactor module according to claim 1 or 2, wherein the shortest distance between the outer surface of the tube and the inner surface of the outer cylinder is 40 mm or less when the outer diameter of the tube is 8 mm to 400 mm.

4. The photoreactor module according to any one of claims 1 to 3, wherein the inner circumferential surface of the outer cylinder has a reflectance of 80% or more to light from the light source.

5. The photoreactor module according to any one of claims 1 to 4, wherein the cross-sectional shape perpendicular to the central axis of the tube is the same as the cross-sectional shape perpendicular to the central axis of the outer cylinder.

6. The photoreactor module according to claim 5, wherein the central axis of the tube is the same as the central axis of the outer cylinder.

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