JP2023128560A - photoreactor system - Google Patents

Abstract

To provide a photoreactor module that can control the internal temperature of a photoreactor.SOLUTION: A photoreactor system 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; a light source that is disposed outside the pipe and directs light toward the granules; a cooling mechanism that is disposed outside the pipe to cool the light source; and a controller that adjusts the output of the cooling mechanism to control the internal temperature of the photoreactor.SELECTED DRAWING: Figure 4

Description

The present invention relates to photoreactor systems.

Conventionally, photoreactors have been known in which a photocatalyst body coated with a photocatalyst is irradiated with light and a substance to be treated such as a gas or liquid is passed through the photocatalyst to decompose organic substances contained in the substance to be treated through a photocatalytic reaction. ing.

For example, in Patent Document 1, a plurality of hollow tubes having the same inner diameter are arranged in the longitudinal direction between an inner tube and an outer tube formed of a light guide, and at least the inner peripheral surface of each hollow tube is discloses a photocatalytic purification device in which a photocatalyst layer that is excited by excitation light is formed. Furthermore, it is described that an excitation light source for exciting the photocatalyst layer is provided at the center of the inner tube or on the outer peripheral side of the outer tube.

Japanese Patent Application Publication No. 2015-123397

However, in the photocatalytic purification device of Patent Document 1, when the amount of heat dissipated from the excitation light source increases, the temperature inside the photocatalytic purification device increases more than necessary, which may affect processes other than the photocatalytic reaction, such as decomposition and boiling of reactants. There is sex. LEDs are often used as excitation light sources from the viewpoint of light source life and miniaturization of devices, but especially when the excitation light source is an LED, a large amount of heat is released from the light source, and reactions other than the photocatalytic reactions mentioned above and the LED itself Heat deterioration is likely to occur. In the photocatalytic purification device of Patent Document 1, no study has been made on heat management that takes into account the influence of temperature on such chemical reactions.

In view of the above points, one aspect of the present invention aims to provide a photoreactor module that can control the temperature within the photoreactor.

A photoreactor system according to one aspect of the present invention includes a light-transmitting tube and a plurality of particles that are housed inside the tube and include a light guiding material, and a fluid flows through the inside of the tube. a light reactor disposed outside the tube and irradiating light toward the granules; a cooling mechanism disposed outside the tube cooling the light source; and an output of the cooling mechanism. and a control unit that controls the temperature inside the photoreactor by adjusting the temperature.

According to one aspect of the present invention, a photoreactor module that can control the temperature within the photoreactor can be provided.

FIG. 2 is a perspective view of a photoreactor module according to one embodiment. 2 is a sectional view taken along line II in FIG. 1. FIG. FIG. 2 is an enlarged view of a main part of a cross section of a photoreactor module according to an embodiment. FIG. 1 is a schematic diagram illustrating a photoreactor system according to one embodiment. 3 is a flowchart illustrating an example of processing by a control unit. FIG. 3 is a schematic configuration diagram illustrating another example of a photoreactor system according to an embodiment. It is a figure showing a change in temperature within a photoreactor over time. FIG. 3 is a diagram showing a change in temperature of a light source over time.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. Note that, in order to facilitate understanding of the explanation, the same components in each drawing may be denoted by the same reference numerals, and redundant explanations may be omitted.

A photoreactor module according to an embodiment of the present invention will be described.

FIG. 1 is a perspective view of a photoreactor module according to one embodiment, and FIG. 2 is a cross-sectional view taken along II in FIG. As shown in FIGS. 1 and 2, a photoreactor module 100 according to an embodiment of the present invention includes a photoreactor 1 and a light source 5 disposed outside the photoreactor 1. As shown in FIGS. The photoreactor module 100 may further include a support member 4 that supports the light source 5. Further, the photoreactor module 100 includes an inlet at one end through which the fluid F flows in, and an outlet through which the fluid F flows out at the other end, and processes the flowing fluid F by a photoreaction (photochemical reaction) such as a photocatalytic reaction. Process.

The photoreactor module 100 further includes a cooling mechanism 30 outside the tube 2 that cools 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 include, for example, an air-cooled heat sink 6 and a cooling fan 7. The cooling fan 7 can be attached to one end of the photoreactor 1 via a pedestal 11, for example. If the cooling mechanism 30 is water-cooled, it may include a water-cooled heat sink 6A and a radiator 18, which will be described later.

The end of the photoreactor 1 on the inlet side 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 passes through the side surface of the cap 8. A pipe through which the fluid F flows is connected to the connection port 81, and the fluid F can flow into the photoreactor 1 from the connection port 81. Similarly, a flange 9 and a cap 8 are provided at the end of the photoreactor 1 on the outflow side, so that the fluid F can be supplied to the outside of the photoreactor 1 from the connection port 81 penetrating the side surface of the cap 8. It can be made to flow out.

FIG. 3 is an enlarged view of a main part of a cross section of a photoreactor module according to one embodiment. As shown in FIG. 3, the photoreactor 1 includes a light-transmitting tube 2 and a plurality of particles 3 that are housed inside the tube 2 and contain a light guiding material. Alternatively, a photocatalyst layer 31 may be provided. A fluid F containing, for example, harmful substances, organic substances, etc., flows through the pipe 2 as a substance to be treated. The fluid F flowing inside the tube 2 is not particularly limited, and may be a liquid or a gas. Examples of the liquid include ground water, tap water, sewage, beverages, and reactants (substances before photoreaction).

The cross-sectional shape perpendicular to the central axis 10 of the tube 2 (more specifically, the cross-sectional shape of the inner peripheral surface of the tube 2) is circular in the examples shown in FIGS. 1 to 3, but is not limited to this, for example, It can be oval or polygonal (hexagonal, pentagonal, quadrilateral, triangular, etc.). The cross-sectional shape of the tube 2 perpendicular to the central axis 10 may be hexagonal. When the cross-sectional shape perpendicular to the central axis 10 of the tube 2 is hexagonal, the particles 3 accommodated inside the tube 2 have a hexagonal close-packed structure. Therefore, the contact portion between the granules 3 and the inner circumferential surface of the tube 2 can be formed regularly, and the fused surface 15 between the granules 3 and the tube 2, which will be described later, can be formed regularly. Therefore, the optical axis 53 of the light source 5 can be easily aligned with the position of the fusion surface 15, and the illuminance on the entire fusion surface 15 can be improved.

The material constituting the tube 2 may be any light guide material that transmits the light emitted from the light source 5, and for example, heat-resistant glass such as borosilicate glass, soda glass, etc. can be used. For example, when titanium dioxide (TiO ₂ ) is used as a photocatalyst, since titanium dioxide exhibits good absorption for wavelengths of 400 nm or less, the light source 5 uses UV-A (A-region ultraviolet rays or (long wavelength ultraviolet rays)) LEDs (Light Emitting Diodes) are preferred. Therefore, when using titanium dioxide as a photocatalyst, the material constituting the tube 2 is preferably borosilicate glass, which exhibits good transmittance for light with a wavelength of 365 nm.

The inner diameter L2 of the tube 2 is not particularly limited, and any inner diameter can be selected so as to reduce the pressure loss of the entire photoreactor module 100. For example, the inner diameter L2 of the tube 2 can be 6 mm to 400 mm. The inner diameter L2 of 6 mm or more is suitable for accommodating and fusing general-purpose particles 3 with a particle size of 2 mm to 20 mm. The inner diameter L2 of 400 mm or less is suitable for keeping the number of particles 3 fused and connected within a range that can suppress light attenuation. In addition, the inner diameter of the tube 2 means the maximum value of the inner diameter passing through the center of the cross-sectional shape when the cross-sectional shape perpendicular to the central axis 10 of the tube 2 is not circular; When the cross-sectional shape is hexagonal, it means the distance between opposite sides (distance between opposite sides).

The thickness L3 of the tube 2 is not particularly limited, but may be, for example, 15 mm or less. When the thickness L3 of the tube 2 is 15 mm or less, sufficient light transmittance for the photoreaction can be obtained and the photoreaction can be promoted.

Although the shape of the particles 3 is not particularly limited, it is preferably spherical, and it is preferable that the plurality of particles 3 have the same particle size. Thereby, the photoreactor module 100 can exhibit highly homogeneous and stable processing capacity.

The particle diameter of the particles 3 is not particularly limited, but is preferably 2 mm to 20 mm, more preferably 3 mm to 10 mm. By setting the particle diameter of the particles 3 to 2 mm to 20 mm, it is possible to suppress attenuation of light within the particles 3 and to further promote the photoreaction. In addition, by setting the particle size of the particles 3 to 3 mm to 10 mm, the surface area can be increased to further promote the photoreaction, and the heat conductivity during fusion is improved, so that the fusion surface can be easily 15 can be formed.

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

As shown in FIG. 3, the photoreactor 1 has a fusion surface 15 where the particles 3 are fused together at the contact portion between the particles 3. Furthermore, the photoreactor 1 has a welding surface 15 where the particles 3 and the inner circumferential surface of the tube 2 are fused together at a contact portion between the particles 3 and the inner circumferential surface of the tube 2 . These fused surfaces 15 can be formed by heating the tube 2 containing the plurality of particles 3 at a temperature equal to or higher than the melting point of the material constituting the particles 3. Note that the portion where the inner circumferential surface of the tube 2 and the granules 3 are not in contact is defined as a non-fused surface 16 where the inner circumferential surface of the tube 2 and the granules 3 are not fused. That is, the photoreactor 1 has a fused surface 15 where the granules 3 and the inner peripheral surface of the tube 2 are fused together, and a non-fused surface 15 where the inner periphery of the tube 2 and the granules 3 are not fused. 16.

By having a fusion surface 15, the photoreactor 1 directs the light irradiated from the light source 5 to the fusion surface 15 between the inner peripheral surface of the tube 2 and the grains 3, and the fusion surface between the grains 3. The light can be guided to the inside of the photoreactor 1 via the photoreactor 15 . In other words, the inner circumferential surface of the tube 2 and the fused surface 15 of the granules 3 and the fused surfaces 15 of the granules 3 constitute a light guide path C for the light irradiated from the light source 5.

The fused surface 15 between the inner circumferential surface of the tube 2 and the grains 3 is preferably formed in ten or less stages in a direction parallel to the central axis 10 of the tube 2. Thereby, attenuation of light within the grains 3 can be suppressed, and the photoreaction can be further promoted. The particle diameter of the granules 3 mentioned above is selected so that the fusion surface 15 between the inner circumferential surface of the tube 2 and the granules 3 is 10 steps or less in the direction parallel to the central axis 10 of the tube 2. can do.

From the viewpoint of forming the welding 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 as the material constituting the tube 2, and soda glass can be used as the material constituting the granules 3. Thereby, when heated at a temperature equal to or higher than the melting point of the material constituting the granules 3, the fused surface 15 can be formed without deforming the tube 2 due to heat. Note that the heating temperature when forming the fused surface 15 is preferably higher than the melting point of the material forming the particles 3 and lower than the melting point of the material forming the tube 2. However, it is essential that the welding surface 15 is properly formed, and if the melting points of the material constituting the granules 3 and the material constituting the tube 2 are equal, the granules can be heated by successive local heating methods. The body 3 and the granules 3 and the granules 3 and the inner circumferential surface of the tube 2 may be appropriately fused.

A photocatalyst layer 31 may be provided on the surface of the particles 3. The photocatalyst constituting the photocatalyst layer 31 can be selected depending on the object to be treated, and examples thereof include titanium dioxide, zinc oxide, bismuth vanadate (BiVO ₄ ), and the like. When the photocatalyst constituting the photocatalyst layer 31 is titanium dioxide, the oxidation reaction and decomposition reaction provide effects such as air cleaning, water purification, deodorization, sterilization, and antifouling. By providing the photocatalyst layer 31 on the surface of the granules 3, it is possible to increase the contact area between the fluid F, which is the object to be treated, and the photocatalyst, and at the same time, increase the irradiation area of the photocatalyst with light. Because of this, the photocatalytic reaction can be promoted. The photocatalyst layer 31 may be provided on the surface of the particles 3 and the inner peripheral surface of the tube 2.

The light source 5 is arranged on the outside of the tube 2, specifically, on the inner peripheral surface of the support member 4, and irradiates light toward the particles 3. The light emitted from the light source 5 enters the outer peripheral surface of the tube 2 and is transmitted to the inner peripheral surface of the tube 2. As the light source 5, any light source can be selected depending on the photocatalyst, and specific examples include a UV light (black light), a xenon lamp, an excimer lamp, and the like. A specific example of the UV light is a UV-A LED. For example, when titanium dioxide is used as a photocatalyst, a UV-A LED with an excitation wavelength of 365 nm is preferable as the light source 5 because it exhibits good absorption for wavelengths of 400 nm or less.

The number of light sources 5 is not particularly limited and can be determined from the power consumption of the entire photoreactor module 100 and the amount of heat dissipated by the light sources 5. The light source 5 includes, for example, a plurality of light emitting elements 51 (for example, LED elements) provided on the surface of a substrate 52 that is directly or indirectly attached to the inner peripheral surface of the support member 4. The light source 5 may include a plurality of light emitting elements 51 arranged with optical axes 53 aligned in a direction perpendicular to the surface of the substrate 52.

A plurality of light sources 5 may be arranged in parallel to or perpendicular to the central axis 10 of the tube 2 on the surface of the support member 4 facing the tube 2 (the inner peripheral surface of the support member 4). . The light sources 5 may be light emitting units arranged in a row on the substrate 52 at predetermined intervals. For example, six light emitting units each including a plurality of light emitting elements 51 arranged parallel to the central axis 10 of the tube 2 may be arranged on the inner peripheral surface of the support member 4 at equal intervals in the circumferential direction. Alternatively, six light emitting units each including a plurality of light emitting elements 51 arranged orthogonally to the central axis 10 of the tube 2 may be arranged on the inner peripheral surface of the support member 4 at equal intervals in the circumferential direction. 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 grains 3 is in the circumferential direction of the tube 2 (the center of the tube 2 They are arranged in a straight line along a direction (perpendicular to the axis 10). Therefore, it is preferable that a plurality of light sources 5 are arranged side by side in a direction orthogonal to the central axis 10 of the tube 2 on the surface of the support member 4 facing the tube 2 (the inner circumferential surface of the support member 4).

It is preferable that the light source 5 is arranged such that the optical axis 53 of the light source 5 is perpendicular to the fusion surface 15 of the granules 3 and the inner circumferential surface of the tube 2 . In other words, the optical axis 53 of the light source 5 is preferably perpendicular to the fusion surface 15. Since the optical axis 53 of the light source 5 is perpendicular to the fusion surface 15, the illuminance on the fusion surface 15 can be made greater than the illumination intensity on the non-fusion surface 16. Therefore, the light irradiated from the light source 5 can be guided from the fusion surface 15 between the particles 3 and the inner peripheral surface of the tube 2 along the light guide path C to the inside of the photoreactor 1. Furthermore, when the photocatalyst layer 31 is provided on the surface of the granules 3, the amount of light received by the photocatalyst layer 31 on the surface of the granules 3 can be increased. As described above, the photoreactor module 100 of this embodiment can promote photoreactions such as photocatalytic reactions.

The support member 4 may be plate-shaped or may be an outer cylinder having a cylindrical shape. When the support member 4 is an outer cylinder, the support member 4 is arranged to surround the photoreactor 1 from the outside in the radial direction of the tube 2 . In other words, the photoreactor 1 is arranged inside the support member 4. The support member 4 is preferably arranged 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 support member 4. Hereinafter, the central axis 10 of the tube 2 will also be used as the central axis of the support member 4.

It is preferable that the inner peripheral surface of the support member 4 reflects the light from the light source 5. The light emitted from the light source 5 includes light that directly enters the photoreactor 1 and light that travels straight through the outside of the photoreactor 1. It is reflected by the inner peripheral surface and enters the photoreactor 1. Furthermore, light scattered outside the photoreactor 1 is also reflected by the inner peripheral surface of the support member 4 and enters the photoreactor 1 . Therefore, by reflecting the light from the light source 5, the inner circumferential surface of the support member 4 can guide more light from the outside of the photoreactor 1 into the inside of the photoreactor 1, so that photocatalytic reactions, etc. Can promote photoreactions.

In FIG. 3, the shortest distance L1 between the outer peripheral surface of the tube 2 of the photoreactor 1 and the inner peripheral surface of the support member 4 is set to be 40 mm or less when the outer diameter of the tube 2 is 80 mm to 400 mm. It is preferable. By setting the shortest distance L1 to 40 mm or less, it is possible to suppress the light emitted from the light source 5 from being scattered and attenuated in the air before reaching the photoreactor 1, thereby preventing the photocatalytic reaction. It is possible to promote photoreactions such as

The inner peripheral surface of the support member 4 may be made of a reflective material or may be coated with a reflective material. Examples of the reflective material include, but are not limited to, metals such as aluminum, polytetrafluoroethylene, and the like. Among these, the reflective material is preferably metal. Since the reflective material is metal, deterioration can be suppressed even when the light emitted from the light source 5 has a short wavelength (for example, 280 nm or less).

The inner circumferential surface of the support member 4 preferably has a reflectance of 80% or more for the light from the light source 5, and the higher the reflectance, the more preferable. By setting the reflectance of the inner circumferential surface of the support member 4 to the light from the light source 5 to be 80% or more, more light from outside the photoreactor 1 can be reflected and guided into the inside of the photoreactor 1. Therefore, photoreactions such as photocatalytic reactions can be promoted. The inner peripheral surface of the support member 4 may be a mirror surface or a scattering surface.

The cross-sectional shape of the supporting member 4 perpendicular to the central axis 10 (more specifically, the cross-sectional shape of the inner circumferential surface of the supporting member 4) is circular, oval, or polygonal (hexagonal, pentagonal, quadrilateral, triangular, etc.). It can be done. The cross-sectional shape of the support member 4 perpendicular to the central axis 10 may be the same as the cross-sectional shape of the tube 2 perpendicular to the central axis 10 . As a result, the distance between the tube 2 and the support member 4 becomes uniform in the circumferential direction, and the light from the light source 5 arranged on the inner peripheral surface of the tube 2 can be uniformly irradiated onto the photoreactor 1. . Therefore, the photoreactor module 100 can exhibit highly homogeneous and stable processing capacity. Further, the cross-sectional shape of the support member 4 perpendicular to the central axis 10 is preferably a polygon such as a hexagon, a pentagon, a quadrangle, or a triangle. As a result, the mounting plane of the light source 5 (for example, the back surface of the substrate 52) can be placed in close contact with the inner circumferential surface of the support member 4, and the heat of the light source 5 can be conducted to the support member 4, allowing the heat to be transferred from the support member 4. It can dissipate heat. Therefore, it is possible to suppress the temperature inside the photoreactor 1 from increasing more than necessary due to the heat of the light source 5, and also to suppress damage or deterioration of the light source 5 due to heat.

The inner diameter of the support member 4 is not particularly limited, and can be arbitrarily selected depending on the material constituting the tube 2, the outer diameter of the tube 2, the excitation wavelength of the light source 5, and the like. For example, when using a tube 2 made of borosilicate glass with a diameter of 80 mm and a light source 5 with an excitation wavelength of 365 nm, the inner diameter of the support member 4 is equal to the outer peripheral surface of the photoreactor 1 or tube 2 and the diameter of the support member 4. It is preferable to set the shortest distance L1 to the inner peripheral surface to be 40 mm or less. Note that the inner diameter of the supporting member 4 means the maximum value of the inner diameter passing through the center of the cross-sectional shape when the cross-sectional shape perpendicular to the central axis 10 of the supporting member 4 is not circular; When the cross-sectional shape perpendicular to 10 is hexagonal, it means the distance across opposite sides.

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

First, the tube 2 and a large number of particles 3 are prepared, and a photocatalyst solution for providing the photocatalyst layer 31 is also prepared. The photocatalyst solution may have titanium dioxide as a main component, for example, and may contain a necessary binder and the like. Next, the tube 2 is erected on the substrate jig, and the inside of the tube 2 is filled by introducing the granules 3 from the upper end opening of the tube 2. Then, the tube 2 filled with the granules 3 is housed in a heating furnace heated by a heater, and heat-treated for a preset heating time Z under a temperature environment of a heating temperature T [° C.]. As a result, the surfaces of the tube 2 and the granules 3 are melted by the heating temperature T [°C], and the contact areas between the tube 2 and the granules 3 and the abutments between the granules 3 are welded, respectively. , a fused surface 15 having a predetermined area is generated. In this case, if the heating temperature T [° C.] is too low, insufficient melting will occur and a sufficient and good fused surface 15 will not be obtained. Furthermore, if the heating temperature T [° C.] is too high, excessive melting will occur, making it impossible to obtain a good internal shape, and the flow path will also become narrow. Therefore, it is desirable that the heating temperature T [° C.] and the heating time Z be set to optimal values through experiments or the like. Note that the heating temperature T [° C.] is preferably higher than the melting point of the material constituting the granules 3 and lower than the melting point of the material constituting the tube 2. For example, the heating temperature T [°C] can be set to 600 to 700 [°C]. As a result, a continuous light guide path C is provided in the tube 2 and the granules 3 via the fusion surface 15. After the heating time Z has elapsed, the tube 2 is taken out from the heating furnace and cooled down to room temperature by natural cooling.

Next, the photocatalyst solution is injected from the upper end opening of the tube 2 to fill the interior of the tube 2 with the photocatalyst solution (step a). At this time, if necessary, vibration or the like can be applied to allow the photocatalyst solution to penetrate into the gaps between the particles 3. After a predetermined time has elapsed, the photocatalyst solution is discharged from the tube 2 (step b). Then, the tube 2 containing the granules 3 after the photocatalyst solution has been discharged is dried or fired (step c). As a result, the photocatalyst layer 31 using titanium dioxide is provided on the surface of the granules 3 excluding the fused surface 15 and on the inner peripheral surface of the tube 2. By such a method, a uniform photocatalyst layer 31 can be easily provided on the surface of the particles 3 and the inner peripheral surface of the tube 2. Note that, if necessary, the film thickness (layer thickness) of the photocatalyst layer 31 can be adjusted by repeating steps a to c. After that, the substrate jig is removed, finishing is performed such as removing unnecessary photocatalyst layer 31 attached to the end face and outer peripheral surface of the tube 2, and the photoreactor 1 is further inspected for light guiding properties. Obtainable. Note that if the photocatalyst layer 31 is not provided on the surface of the granules 3 or the inner peripheral surface of the tube 2, steps a to c are unnecessary.

By attaching flanges 9 and caps 8 to the openings at both ends of the obtained photoreactor 1, a photoreactor module 100 can be constructed. Then, a pipe through which the fluid F flows is connected to the connection port 81 of the cap 8. Thereby, a photoreactor module 100 is obtained in which one end of the tube 2 serves as an inlet for fluid F and the other end serves as an outlet for fluid F.

Next, the photoreactor system 200 will be explained.

FIG. 4 is a schematic diagram illustrating a photoreactor system according to one embodiment. As shown in FIG. 4, a photoreactor system 200 according to an embodiment of the present invention includes a light-transmitting tube 2 and a plurality of particles 3 housed inside the tube 2 and containing a light guide material. a photoreactor 1 in which a fluid F flows inside the tube 2; a light source 5 placed outside the tube 2 to irradiate light toward the particles 3; 5. A cooling mechanism 30 is provided. The photoreactor system 200 also includes a control unit 220 that controls the temperature inside the photoreactor 1 by adjusting the output of the cooling mechanism 30.

In the example shown in FIG. 4, the cooling mechanism 30 includes an air-cooled heat sink 6 and a cooling fan 7, and is air-cooled, but may be water-cooled. In addition, in the example shown in FIG. 4, an example will be described in which the cooling fan 7 is disposed on the inlet side of the photoreactor module 100; however, the cooling fan 7 is not limited to this, and for example, It may be placed on the exit side.

A fluid supply line 241 for supplying fluid F into the photoreactor 1 is connected to the inlet side end of the photoreactor 1, and a 1 is connected to a fluid outflow line 242 through which a fluid F treated by photoreaction flows.

The cooling air (cooling medium) A1 taken in by the cooling fan 7 flows between the tube 2 of the photoreactor 1 and the support member 4, and after cooling the light source 5 and the tube 2 supported by the support member 4, It is discharged from an exhaust line 243 connected to the outlet side of the photoreactor module 100. When the cooling air (cooling medium) A1 flows between the tube 2 and the support member 4 of the photoreactor 1, the light source 5 and the tube 2 are directly hit by the cooling air A1 and are cooled. 1 and the temperature of the light source 5 can be lowered. The control unit 220 can control the temperature inside the photoreactor 1 by adjusting the output of the cooling mechanism 30, and can maintain the temperature inside the photoreactor 1 at a temperature appropriate for the photoreaction. I can do it.

The cooling air (cooling medium) A2 taken in by the cooling fan 7 flows outside the support member 4, cools the air-cooled heat sink 6 provided on the outer peripheral surface of the support member 4, and then flows through the photoreactor module 100. It may be exhausted from an exhaust line 243 connected to the outlet side. The cooling air A2 taken in by the cooling fan 7 flows outside the support member 4, and the air-cooled heat sink 6 is cooled by coming into contact with the cooling air A2. The heat transmitted to the heat sink 6 is radiated. Therefore, the temperature inside the photoreactor 1 and the light source 5 can be lowered. The control unit 220 can control the temperature inside the photoreactor 1 by adjusting the output of the cooling mechanism 30, and can maintain the temperature inside the photoreactor 1 at a temperature appropriate for the photoreaction. I can do it.

In the photoreactor module 100 or the photoreactor system 200, when the cooling air (cooling medium) taken in by the cooling fan 7 flows between the tube 2 of the photoreactor 1 and the support member 4, the photoreactor module 100 or the photoreactor system 200 It has an air passage switching mechanism that can switch the air passage to three patterns: when the air flows outside, and when it flows between the tube 2 of the photoreactor 1 and the support member 4 and outside the support member 4. It's okay. The air path switching mechanism is not particularly limited, but for example, a damper that opens and closes an opening between the tube 2 and the support member 4 at one end of the photoreactor 1 may be provided, or a damper may be provided downstream of the cooling fan 7. A damper may be provided on the side line.

The photoreactor system 200 may include a first temperature measurement section 211 that measures the temperature inside the photoreactor 1 and a second temperature measurement section 212 that measures the temperature of the light source 5. The control unit 220 may control (adjust) the output of the cooling mechanism 30 based on the measured temperatures of the first temperature measurement unit 211 and the second temperature measurement unit 212. In the example shown in FIG. 4, the first temperature measuring section 211 is provided on the outlet side of the photoreactor 1, but it can be provided at any position of the photoreactor 1. The second temperature measuring section 212 can be provided, for example, on the substrate 52 of the light source 5 or the light emitting element 51.

The control unit 220 may control the output of the cooling mechanism 30 based on the temperatures measured by the first temperature measurement unit 211 and the second temperature measurement unit 212. When the cooling mechanism 30 is an air-cooling type, the control unit 220 controls the output of the cooling fan 7, and when the cooling mechanism 30 is a water-cooling type, the control unit 220 controls the flow of a cooling medium flowing into the radiator 18, which will be described later. As a control method by which the control unit 220 controls the motor that rotates the cooling fan 7, variable voltage variable frequency (VVVF) control can be used, for example.

It is preferable that the control unit 220 controls the output of the cooling mechanism 30 so that the temperature measured by the first temperature measurement unit 211 that measures the temperature inside the photoreactor 1 is constant. By controlling in this way, the temperature inside the photoreactor 1 can be maintained constant, and photoreactions such as photocatalytic reactions can be stably maintained. Further, it is preferable that the control unit 220 controls the output of the cooling mechanism 30 so that the temperature measured by the first temperature measurement unit 211 is equal to or higher than the reaction temperature of the organic matter contained in the fluid F. By controlling in this way, it is possible to prevent the temperature inside the photoreactor 1 from becoming lower than the reaction temperature of the organic substance by the cooling mechanism 30, thereby preventing the reaction rate from decreasing, and to further promote the photoreaction.

The control unit 220 may further control the output of the cooling mechanism 30 so that the temperature measured by the first temperature measurement unit 211 is equal to or lower than the decomposition temperature of the organic matter contained in the fluid F. By controlling in this way, it is possible to suppress the temperature inside the photoreactor 1 from increasing more than necessary, and to suppress the organic substances contained in the fluid F from decomposing. Further, the control unit 220 may control the output of the cooling mechanism 30 so that the temperature measured by the first temperature measurement unit 211 is equal to or lower than the boiling point of the fluid F. By controlling in this way, it is possible to suppress the temperature inside the photoreactor 1 from increasing more than necessary and to suppress the fluid F from boiling.

It is preferable that the control unit 220 controls the output of the cooling mechanism 30 so that the temperature measured by the second temperature measurement unit 212 is equal to or lower than the allowable temperature of the light source 5. The allowable temperature includes the damage temperature at which the light source 5 is damaged due to dielectric breakdown, etc., the allowable temperature limit of the light source 5, and the like. By controlling in this way, it is possible to prevent the temperature of the light source 5 from rising due to heat generation of the light source 5 and damage to the light source 5. Therefore, the life of the photoreactor module 100 and the photoreactor system 200 can be extended.

The control unit 220 controls the output of the cooling mechanism 30 so that the temperature measured by the first temperature measurement unit 211 is within a predetermined temperature range, and the temperature measured by the second temperature measurement unit 212 is below a predetermined temperature. It is preferable to do so. By controlling in this way, the temperature inside the photoreactor 1 can be maintained at an appropriate temperature for photoreactions such as photocatalytic reactions, the photoreaction can be stably maintained at a high reaction rate, and the photoreaction can be carried out with high efficiency. can be converted into At the same time, it is possible to prevent the temperature of the light source 5 from rising due to the heat generated by the light source 5 and damage to the light source 5, and the life of the photoreactor module 100 and the photoreactor system 200 can be extended.

The control unit 220 may control the above-mentioned air path switching mechanism. When a damper that opens and closes the opening between the pipe 2 and the support member 4 is provided as the air path switching mechanism, the control unit 220 may control the opening and closing of the damper. For example, when increasing the cooling capacity of the cooling mechanism 30, the control unit 220 opens the damper and directs the cooling air taken in by the cooling fan 7 between the tube 2 of the photoreactor 1 and the support member 4 and outside the support member 4. When lowering the cooling capacity of the cooling mechanism 30, the damper may be closed and the flow may be controlled to flow only to the outside of the support member 4.

The control unit 220 is realized as a hardware processing circuit including, for example, a CPU and a memory. In this case, the functions of the control unit 220 are realized by the CPU executing a program stored in the memory.

Next, the processing procedure of the control unit 220 will be explained.

FIG. 5 is a flowchart illustrating an example of processing by the control unit 220. As shown in FIG. 5, the control unit 220 first turns on the cooling fan 7 (step S201), and then turns on the light source 5 (step S202). Next, it is determined whether the temperature measured by the first temperature measuring section 211 is 60° C. or lower (step S203). If the temperature measured by the first temperature measurement unit 211 is 60°C or lower (step S203, YES), it is determined whether the temperature measured by the second temperature measurement unit 212 is 80°C or lower (step S204).

On the other hand, if the temperature measured by the first temperature measurement unit 211 is not 60° C. or lower (step S203, NO), the output of the cooling fan 7 is increased by +n% (step S206). n% means a percentage of the maximum output of the cooling fan 7, and can be any value. Then, it is determined again whether the temperature measured by the first temperature measuring section 211 is 60° C. or lower (step S203). This process is repeated until the temperature measured by the first temperature measurement unit 211 exceeds 60°C.

In step S204, if the temperature measured by the second temperature measurement unit 212 is 80°C or lower (step S204, YES), it is determined whether the temperature measured by the first temperature measurement unit 211 is 40°C or lower (step S205).

On the other hand, if the temperature measured by the second temperature measurement unit 212 is not 80° C. or lower (step S204, NO), the output of the cooling fan 7 is increased by +n% (step S206). Then, the processes of step S203, step S204, and step S206 are repeated.

In step S205, if the temperature measured by the first temperature measurement unit 211 is 40°C or higher (step S205, YES), return to step S203 and determine whether the temperature measured by the first temperature measurement unit 211 is 60°C or lower. Determine.

On the other hand, if the temperature measured by the first temperature measurement unit 211 is not 40° C. or higher (step S205, NO), the output of the cooling fan 7 is lowered by n% (step S207). By lowering the output by n%, the temperature measured by the first temperature measuring section 211, that is, the temperature inside the photoreactor 1 can be increased. Then, the process returns to step S203, and it is determined whether the temperature measured by the first temperature measuring section 211 is 60° C. or lower.

By performing the processing by the control unit 220 as described above, the temperature inside the photoreactor 1 can be controlled to the optimal temperature range for photoreaction, which is 40°C or more and 60°C or less, and the temperature of the light source 5 can be controlled to The temperature can be controlled to below 80° C., which is the allowable temperature of the light source 5. Note that the optimum temperature range for the photoreaction can be selected from any temperature range depending on the reaction temperature or decomposition temperature of the organic matter contained in the fluid F, or the boiling point of the fluid F, and the allowable temperature of the light source 5 is , any temperature can be selected depending on the material of the light source 5, etc.

In the photoreactor system 200 according to the present embodiment, the control unit 220 controls the output of the cooling mechanism 30 based on the measured temperatures of the first temperature measurement unit 211 and the second temperature measurement unit 212, thereby controlling the photoreactor. Based on the temperature inside the photoreactor 1 and the temperature of the light source 5, the temperature inside the photoreactor 1 can be controlled to a more appropriate temperature. At the same time, it is possible to prevent the temperature of the light source 5 from rising due to the heat generated by the light source 5 and damage to the light source 5, and the life of the photoreactor module 100 and the photoreactor system 200 can be extended.

Next, a description will be given of the photoreactor system 200 in which the cooling mechanism 30 is water-cooled.

FIG. 6 is a schematic diagram illustrating another example of a photoreactor system according to an embodiment. In the example shown in FIG. 6, the photoreactor system 200 includes a water-cooled heat sink 6A instead of the air-cooled heat sink 6 in the example shown in FIG. 4, and a radiator 18 in place of the cooling fan 7 in the example shown in FIG. ing. The photoreactor system 200 includes a cooling water circulation pump 17 that circulates cooling water (cooling medium) between the water-cooled heat sink 6A and the radiator 18. The water-cooled heat sink 6A recovers the heat radiated by the light source 5. An exhaust heat recovery circulation line 250 through which cooling water for recovering exhaust heat is circulated is connected to the water-cooled heat sink 6A. The exhaust heat recovery circulation line 250 includes a cooling water discharge line 251 through which water after exhaust heat recovery flows, and a cooling water supply line 252 through which water after being cooled by the radiator 18 flows. The control unit 220 controls the flow rate of the cooling water flowing into the radiator 18 and the like by the cooling water circulation pump 17 based on the temperatures measured by the first temperature measurement unit 211 and the second temperature measurement unit 212. As a control method by which the control unit 220 controls the motor that rotates the coolant circulation pump 17, for example, variable voltage variable frequency (VVVF) control can be used. A configuration similar to the photoreactor system 200 shown in FIG. 4 can be used, except for the configuration described above. With the above configuration, the photoreactor system 200 shown in FIG. 6 also has the same effects as the photoreactor system 200 shown in FIG. 4.

Hereinafter, the embodiments will be described in more detail with reference to Examples and Comparative Examples, but the embodiments are not limited to these Examples.

(Example 1)
In a borosilicate glass tube with an inner diameter (distance across sides) of 30 mm, a height of 50 mm, a thickness of 4 mm, and a regular hexagonal cross section perpendicular to the central axis, multiple particles of the same material with a particle size of 2 mm are housed and fused and connected. did. By applying and baking anatase type TiO ₂ , a photoreactor was obtained in which a TiO ₂ photocatalyst layer was formed on the inner peripheral surface of the tube and on the surface of the particles.

An aluminum cylinder (reflectance: 85%) with an inner diameter (distance across opposite sides) of 60 mm, a height of 40 mm, and a regular hexagonal cross-section perpendicular to the central axis was installed as a support member outside the photoreactor. Two UV-A LED tape lights (365 nm, 60 pieces/m, 360 μW/cm ² ) were attached to the inner peripheral surface of the aluminum cylinder as a light source. Example 1 was carried out by fixing an aluminum heat sink with a thickness of 2 mm, pitch of 2 mm, and height of 20 mm to the outer peripheral surface of an aluminum tube, and installing a DC fan (FAN-100) with a diameter of 90 mm for cooling at the bottom of the photoreactor. A photoreactor module was obtained. The inlet and outlet of the photoreactor are connected with 1/4-inch polytetrafluoroethylene joints, and a thermocouple (TC-110) is installed at the outlet to measure the temperature at the reactor outlet. The photoreactor system of Example 1 was obtained by providing a thermocouple (TC-200) for measuring the surface temperature of the LED substrate.

[Evaluation of fat and oil decomposition performance]
As the fluid containing water-soluble fats and oils to be treated in the photoreactor module, milk prepared with water to a solid content of 1% was used, and was circulated within the photoreactor at a rate of 90 mL/min using a tube pump. An oil and fat decomposition test by photocatalytic reaction was conducted by irradiating the photoreactor with an LED and controlling the fan output so that TC-110 = 60°C and TC-200 < 80°C. The oil and fat decomposition performance was evaluated by quantifying the amount of oil and fat in milk after 10 hours of LED irradiation using TOC (total organic carbon measurement). It means that the higher the fat and oil decomposition performance is, the more the photocatalytic reaction is promoted.

(Comparative example 1)
The same photoreactor system as in Example 1 was used, except that the fan output was operated at 100%, and the temperature inside the photoreactor, the LED temperature, and the oil and fat were measured in the same manner as in Example 1. The decomposition performance was evaluated.

(Example 2)
The same photoreactor system as in Example 1 was used, except that the fan output was operated at 5%, and the temperature inside the photoreactor was measured, the temperature of the LED was measured, and oil and fat were measured in the same manner as in Example 1. The decomposition performance was evaluated.

FIG. 7 shows the temperature change over time in the photoreactors of Example 1, Comparative Example 1, and Comparative Example 2, and FIG. 8 shows the change over time in the temperature of the light source. The temperature inside the reactor of Example 1 was maintained at 60°C. The temperature of the LED of Example 1 was maintained at a temperature not exceeding 80° C., and as a result of measuring the illuminance of the LED with a luminometer after the test, there was no decrease in the illuminance of the LED. Further, the amount of fat and oil decomposed in Example 1 was 40 mg/L. The amount of fat and oil decomposed in Comparative Example 1 was only 3 mg/L, and the temperature inside the reactor at this time was 32°C. In Comparative Example 2, the temperature inside the reactor and the temperature of the LED rose with the operation of the photoreactor system, and when the temperature inside the reactor reached 100°C, the reaction liquid boiled and was seen scattering outside the system. The LED was damaged (insulated) when the temperature exceeded 140°C. As described above, the photoreactor module and photoreactor system of Example 1 can be operated for a long time without impairing the performance of the LED while controlling the temperature inside the photoreactor and maximizing the reaction rate in the photoreactor. I confirmed that it can be done.

Although the embodiments have been described as above, the embodiments are presented as examples, and the present invention is not limited to the embodiments described above. The embodiments described above can be implemented in various other forms, and various combinations, omissions, substitutions, changes, etc. can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention, as well as within the scope of the invention described in the claims and its equivalents.

1 Photoreactor 2 Tube 3 Particles 31 Photocatalyst layer 4 Support member 5 Light source 51 Light emitting element 52 Substrate 53 Optical axis 6 Air-cooled heat sink 6A Water-cooled heat sink 7 Cooling fan 8 Cap 81 Connection port 9 Flange 10 Central axis 11 Pedestal 15 Fusion Bonding surface 16 Non-fusion surface 17 Cooling water circulation pump 18 Radiator 20 Straight line 30 Cooling mechanism 100 Photoreactor module 200 Photoreactor system 211 First temperature measurement section 212 Second temperature measurement section 220 Control section 241 Fluid supply line 242 Fluid outflow Line 243 Exhaust line 250 Exhaust heat recovery circulation line 251 Cooling water discharge line 252 Cooling water supply line

Claims (10)

A photoreactor comprising a translucent tube and a plurality of particles containing a light guide material housed inside the tube, and in which a fluid flows inside the tube;
a light source disposed outside the tube and irradiating light toward the granules;
a cooling mechanism disposed outside the tube and cooling the light source;
A control unit that controls the temperature inside the photoreactor by adjusting the output of the cooling mechanism. The photoreactor system according to claim 1, wherein a photocatalyst layer is provided on the surface of the granules. comprising a support member that holds the light source,
3. The photoreactor system of claim 1 or 2, wherein a cooling medium flows between the tube and the support member. The photoreactor system according to any one of claims 1 to 3, wherein the cooling mechanism includes an air-cooled heat sink and a cooling fan. The photoreactor system according to any one of claims 1 to 3, wherein the cooling mechanism includes a water-cooled heat sink and a radiator. a first temperature measurement unit that measures the temperature inside the photoreactor;
and a second temperature measurement unit that measures the temperature of the light source,
The photoreactor according to any one of claims 1 to 5, wherein the control unit controls the output of the cooling mechanism based on the measured temperatures of the first temperature measurement unit and the second temperature measurement unit. system. The photoreactor system according to claim 6, wherein the control unit controls the output of the cooling mechanism so that the temperature measured by the first temperature measurement unit is constant. The photoreactor system according to claim 6 or 7, wherein the control unit controls the output of the cooling mechanism so that the temperature measured by the first temperature measurement unit is equal to or higher than the reaction temperature of an organic substance contained in the fluid. . The photoreactor according to any one of claims 6 to 8, wherein the control unit controls the output of the cooling mechanism so that the temperature measured by the second temperature measurement unit is equal to or lower than the allowable temperature of the light source. system. The control unit controls the output of the cooling mechanism so that the temperature measured by the first temperature measurement unit is within a predetermined temperature range, and the temperature measured by the second temperature measurement unit is below a predetermined temperature. 10. A photoreactor system according to any one of claims 6 to 9.

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