WO2013133433A1 - Photocatalyst reactor - Google Patents

Abstract

[Problem] To provide a photocatalyst reaction unit and a photocatalyst reactor with high processing capacity on the basis of high light utilization efficiency. [Solution] A photocatalytic reaction unit is provided with a light guide body, which is provided with a light guide body substrate, which has a vertical axis line, a peripheral surface around the vertical axis line, and two end surfaces that cross the vertical axis line, and a photocatalyst layer affixed to the peripheral surface or an intermediate layer provided on the peripheral surface of the light guide body substrate, the photocatalytic reaction unit also being provided with a light source disposed such that the light there from is incident into the light guide body substrate from at least one end surface of the light guide body substrate and also having the light guide body inserted into a fluid to be processed. The light guide body has recessed parts formed continuously or partially centered on the vertical axis line such that at least part of the light incident from the end surface radiates to the photocatalyst layer side.

Description

Photocatalytic reactor

The present invention relates to a photocatalytic reaction apparatus that processes a fluid using a photocatalytic reaction.

For example, Patent Document 1 discloses an apparatus for performing deodorization, sterilization, virus inactivation, or the like on a fluid to be treated such as waste liquid using a photocatalytic reaction. The apparatus disclosed in Patent Document 1 includes a plurality of plate-like optical waveguides coated with a photocatalyst, a condensing lens provided on one end side of each optical waveguide, and a common one for the plurality of optical waveguides. A light source, and causes a photocatalytic reaction by light incident from one end of the optical waveguide and emitted from the outer peripheral surface. This apparatus can carry out a treatment utilizing a photocatalytic reaction even with a fluid to be treated having a low transparency by an optical waveguide that emits light and coated with a photocatalyst.

Japanese Patent Laid-Open No. 9-299937

However, according to the optical waveguide of the apparatus of Patent Document 1, light having an angle larger than the critical angle with respect to the outer peripheral surface out of the light incident from the end surface on the light source side is totally reflected and emitted from the end surface on the opposite side. Light rays that hardly contribute to the reaction and are smaller than the critical angle are emitted from the outer peripheral surface of the optical waveguide, but most of them are emitted from a section near the incident end. For this reason, according to the optical waveguide of the apparatus of Patent Document 1, it is considered that only a part of the light incident thereon can be used, and only the optical waveguide having a relatively short length can be used.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a photocatalytic reaction unit and a photocatalytic reaction apparatus having a high processing capability based on high light utilization efficiency.

In order to solve the above problems, a first aspect of the present invention includes a light guide body having a vertical axis, an outer peripheral surface around the vertical axis, and two end faces intersecting the vertical axis, A light guide comprising a photocatalyst layer fixed to an outer peripheral surface or an intermediate layer provided on the outer peripheral surface, and light incident on the light guide base from at least one end face of the light guide base. A photocatalytic reaction unit, wherein the light guide is inserted into a fluid to be processed, wherein the light guide transmits at least part of light incident from the end face to the photocatalyst layer side. The photocatalytic reaction unit is provided with a concave portion provided so as to radiate to the surface, and the concave portion is formed continuously or partially around the longitudinal axis.

According to this, among the light components incident from the end face of the light guide, the light component that has been totally reflected and emitted from the opposite end face and hardly contributed to the photocatalytic reaction has a vertical axis. Since the light is radiated from the outer peripheral surface of the light guide body by the concave portion formed continuously or partially as the center, the light intensity is increased and the distribution is improved as compared with the case where such a concave portion is not provided. As a result, a photocatalytic reaction unit having high light utilization efficiency and high processing capacity can be realized.

In the first aspect of the present invention, the intermediate layer is preferably a light transmissive tube.

In the first aspect of the present invention, the recess may be configured by a plurality of annular grooves, and the plurality of annular grooves may be arranged at a constant pitch or a varying pitch with respect to the longitudinal direction of the light guide. *

In the first aspect of the present invention, the light guide has a grooveless section without grooves from the end surface on the light source side, and the length of the grooveless section is larger than the pitch of the annular grooves. Is preferred.

In the first aspect of the present invention, the cross-sectional shape of the annular groove may be any of a U shape, a semicircular shape, an arc shape shallower than a semicircle, or a V shape.

In the first aspect of the present invention, the light source may be disposed close to the end face of the light guide. Thereby, it becomes possible to raise the coupling efficiency of the light between a light source and a light guide with a simple structure.

In the first aspect of the present invention, the photocatalytic reaction unit may further include at least one lens disposed between the light source and the light guide. As a result, it is possible to further increase the light coupling efficiency and to obtain a desired incident angle range of light with respect to the light guide, and as a result, to obtain a more desirable light intensity distribution on the outer peripheral surface of the light guide. It becomes possible.

According to a second aspect of the present invention, there is provided a photocatalytic reaction device comprising one or a plurality of photocatalytic reaction units of the first aspect and a casing forming a flow passage for a fluid to be treated. The photocatalytic reaction device in which the light guide of the photocatalytic reaction unit is disposed in the flow path is provided. In the photocatalytic reaction device in which one light guide is arranged in one casing, it is preferable that the distance between the catalyst layer on the light guide and the inner peripheral surface of the casing is 1.5 mm or less. Thereby, the processing effect (decomposition effect) by decomposition | disassembly of the organic substance in a fluid, oxidation reduction reaction, etc. can be improved significantly. In addition, in the photocatalytic reaction device in which a plurality of the photocatalytic reaction units of the first aspect are arranged in one casing, it is possible to mount the photocatalytic reaction units of the first aspect that can be formed elongated in high density. Thus, it is possible to realize a photocatalytic reaction device having a large surface area of a photocatalyst layer and a high processing capability.

In the second aspect of the present invention, each of the one or more photocatalytic reaction units includes at least one lens disposed between the light source and the light guide, and the lenses of the plurality of photocatalytic reaction units include: One or a plurality of photocatalytic reaction units may be integrally formed on a common substrate. This makes it possible to easily adjust the optical axis even when there are many light guides.

FIG. 1 is a partial sectional view of a photocatalytic reaction unit according to a first embodiment of the present invention. FIG. 2 is an enlarged longitudinal sectional view of the light guide showing the sectional shape of the annular groove of the photocatalytic reaction unit according to the present invention. FIG. 3 is an enlarged longitudinal sectional view of the light guide schematically showing the reflection of light in the annular groove of the photocatalytic reaction unit of the first embodiment. FIG. 4 is a partial cross-sectional view of the main part of the photocatalytic reaction unit according to the second embodiment of the present invention. FIG. 5 is a schematic longitudinal sectional view of a photocatalytic reaction device in which one light guide of a photocatalytic reaction unit according to the fourth embodiment of the present invention is arranged. FIG. 6 is a diagram showing the relationship between the decomposition effect of the photocatalytic reaction device of the fourth embodiment and the distance between the photocatalytic layer on the light guide and the inner peripheral surface of the casing. FIG. 7 is a schematic longitudinal sectional view of a photocatalytic reaction device in which a plurality of light guides of the photocatalytic reaction unit according to the fourth embodiment of the present invention are arranged. FIG. 8 is a plan view of the first collective lens of the photocatalytic reaction device of the fourth embodiment. FIG. 9 is a plan view of the second collective lens of the photocatalytic reaction device of the fourth embodiment. FIG. 10 is an enlarged longitudinal sectional view of a light guide showing a sectional shape of a modified example of the annular groove of the photocatalytic reaction unit according to the present invention.

A photocatalytic reaction unit 1 according to a first embodiment of the present invention will be described with reference to FIGS.
The photocatalytic reaction unit 1 according to the first embodiment includes an elongated cylindrical light guide base 9 having a longitudinal axis Ax, a light-transmitting tube 40 covered on the outer peripheral surface 11 of the light guide base 9, A light guide 10 including a photocatalyst layer (not shown) made of titanium oxide thinly and uniformly applied to the outer peripheral surface of the tube 40, and the light guide 10 is disposed above the upper end surface of FIG. A light source 20, and a lens group 30 and a tube which are disposed between the light source 20 and the upper end surface of the light guide 10 to increase the coupling efficiency of the light and obtain a desired incident angle range of light to the light guide. A columnar sealing member 50 provided on the front end side of 40 and a lens barrel 60 for connecting the light source 20 and the lens group 30 to the light guide 10 are provided. The tube 40 is an intermediate layer between the light guide base 9 and the photocatalyst layer.

The light source 20 includes a light emitting diode 21 that emits ultraviolet rays. The light source 20 is held by the lens barrel 60 so that the center of the LED chip 22 that is a light emitting portion of the light emitting diode 21 is positioned on the vertical axis Ax of the light guide 10. Yes. The light source 20 also includes a substrate 23 to which the light emitting diode 21 is fixed and a lead wire (not shown) connected to the substrate 23, and is supplied with power from a power source (not shown).

In this embodiment, the lens group 30 includes a first lens 31 that is a biconvex lens on the light source 20 side and a second lens 32 that is a hemispherical lens, and the optical axis thereof is the vertical axis Ax of the light guide 10. It is held by the lens barrel 60 so as to be positioned above.

The light transmissive tube 40 is a heat shrinkable type made of a fluororesin that transmits ultraviolet rays emitted from the light source 20. The tube 40 covers the outer peripheral surface 11 of the light guide substrate 9 from the base end portion to the distal end portion, and also covers the sealing member 50 disposed following the distal end portion of the light guide substrate base 9. Since the tube 40 is of a heat shrink type, it is heat shrunk and is in close contact with the light guide base 9 and the sealing member 50. The tube 40 and the sealing member 50 are welded to each other so that the liquid to be processed does not enter from the gap between the sealing member 50 and the inner peripheral surface of the tube 40. In addition, the tube 40 of the present embodiment is covered with the light guide base 9, and after being brought into close contact with the light guide base 9 and the sealing member 50 by thermal contraction, titanium oxide is applied thereto.

The sealing member 50 is made of a white fluororesin, and it is also intended to reflect light as much as possible at the inner end face 51. Therefore, in order to improve the light reflection efficiency, aluminum sealing may be performed on the sealing member 50 and / or the inner end face 51 of the sealing member 50 may be formed as a conical convex surface.

The light guide substrate 9 of the photocatalytic reaction unit 1 of the first embodiment is made of an elongated quartz glass having a diameter of about 6 mm and a total length of 1 m, and has a smooth outer peripheral surface 11, upper end surface 12 and lower end surface 13. On the outer peripheral surface 11, except for a certain section L from the upper end (hereinafter referred to as “groove-free section”), a large number of annular grooves 14 are formed at the tip portion at a pitch P of about 3 mm in the direction of the vertical axis Ax. Is formed. The grooveless section L is larger than the pitch P of the annular groove 14 and is provided with a length of about twice the diameter of the light guide substrate 9 in this embodiment. The material of the light guide base 9 may be synthetic quartz, borosilicate glass, fluororesin, or the like, which is UV transmissive.

The plurality of annular grooves 14 are formed and arranged to radiate light incident from the upper end surface 12 of the light guide base body 9 from the outer peripheral surface 11, and the cross-sectional shape thereof is shown in FIG. It is U-shaped as shown in a). The surface of the annular groove 14 is smoothed to the same extent as the outer peripheral surface 11 of the light guide base 9.

By the way, in the present embodiment, although the tube 40 is in close contact with the light guide base 9, it is considered that an air layer exists between the tube 40 and the light guide base 9, and then the light guide base is formed. 9 has a critical angle of about 43 ° at which total reflection occurs on the outer peripheral surface 11. On the other hand, even when it is assumed that there is no air layer between the tube 40 made of fluororesin and the surface of the light guide substrate 9, a critical angle exists because the refractive index of fluororesin is smaller than that of quartz glass. Therefore, in any case, in the photocatalytic reaction unit 1 of the present embodiment, the light having an angle smaller than the critical angle out of the light incident from the end surface 12 of the light guide substrate 9 is not totally reflected by the outer peripheral surface 11 and is mainly reflected. Most of the light rays radiated from the grooveless section L close to the incident end and having an angle larger than the critical angle are totally reflected by the outer peripheral surface 11 and travel through the light guide substrate 9, but the opposite end surface 13. Before reaching, most of the angle of light strikes one of the many annular grooves 14 and radiates out of the light guide substrate 9 from the surface of the annular groove 14. This is because, as schematically shown in FIG. 3, the light ray R that has traveled by being totally reflected by the outer peripheral surface 11 hits the side surface (the side surface on the right side of the drawing) closer to the light source 20 of the annular groove 14, This is because the incident angle with respect to the side surface is much smaller than the critical angle except when it hits the bottom of the U-shape of the annular groove 14.

The light beam R emitted from the side surface of the annular groove 14 closer to the light source 20 to the outside of the light guide substrate 9 is reflected directly or within the annular groove 14 one or more times to reach the tube 40. The photocatalyst layer (not shown) adhering to the surface of the tube 40 is irradiated. At this time, the light radiated from the annular groove 14 is incident on the tube 40 while repeating complicated reflections with the inner peripheral surface of the tube 40, thereby causing a light diffusion effect. By diffusing to the range shown, sufficient light intensity can be obtained not only directly above the annular groove 14 but also in an intermediate region between the grooves.

As for the macro distribution of the light intensity in the direction of the vertical axis Ax, as an example, a U-shaped groove having a groove width of 0.25 mm and a groove depth of 0.17 mm is formed on the above-described light guide body 9 having a diameter of 6 mm and a total length of 1 m. When arranged at a pitch P of 3 mm and covered with a fluororesin tube 40, the measured light intensity is 10 mW / cm ² at a position 20 mm from the incident end and a position of 500 mm when the LED of the light source 20 has an output of 400 mW. ^{13mW / cm 2, 2.7mW / cm} 2 at the position of 700mm at a position of 5.3mW / cm ^2, 900mm, was 1.7 mW / cm ² at the cutting edge portion. Since it is known that a light intensity of 1 mW / cm ² or more is sufficient for the photocatalytic reaction of titanium oxide, according to the photocatalytic reaction unit 1 of this embodiment, a very long light guide having a diameter of 6 mm and a total length of 1 m. Even when the substrate 9 was used, it was confirmed that necessary light intensity could be obtained from the base end portion to the tip end portion.

By the way, as a main function of the fluororesin tube 40 in this embodiment, the adhesion strength of titanium oxide is increased as compared with the case of direct application to the quartz glass light guide substrate 9, and the light guide substrate. The protection of the broken light guide when the light guide substrate 9 is broken in the processing liquid is facilitated, and the light guide substrate 9 with an annular groove is further mentioned. It has been confirmed by the inventors of the present invention that covering the tube 40 with the tube 40 increases the light intensity more than twice as compared with the case where the tube 40 is not covered.

In the photocatalytic reaction unit 1 configured as described above, the lens group 30 and the light source 20 are disposed outside the liquid (not shown) to be processed, and the light guide 10 is immersed in the liquid to place the light source 20 in the liquid. By emitting light, treatments such as decomposition of organic substances in liquid and oxidation-reduction reaction can be performed. Moreover, in order to prevent the elongate light guide 10 from being damaged, it may be supported by a support member (not shown) as necessary.

Next, the photocatalytic reaction unit 2 according to the second embodiment will be described below with reference to FIG. The photocatalytic reaction unit 2 of this embodiment is different from that of the first embodiment in that it does not have the lens group 30, but the other configurations are the same. The light emitting diode 21 of the light source 20 is coupled to the light guide 10 so that the LED chip 22 that is the light emitting portion is as close to the end face of the light guide 10 as possible. Further, a coupling sleeve 160 is used for coupling, and the coupling sleeve 160, the light guide body 10, and the light emitting diode 21 are bonded and fixed.

By not providing the lens group 30 in this way, the structure can be simplified and the manufacturing cost can be reduced, but the light between the light source 20 and the light guide 10 can be reduced as compared with the case of the first embodiment. As the coupling efficiency of the light guide body 10 decreases, the proportion of light emission on the base end side of the light guide body 10 increases, so the possible length of the light guide body 10 becomes shorter. However, since the light component that has been totally reflected and hardly contributed to the photocatalytic reaction is radiated from the outer peripheral surface 11 by the annular groove 14, the light intensity is increased as compared with the case where the annular groove 14 is not provided. And improved distribution.

Next, the photocatalytic reaction unit 3 according to the third embodiment will be described below. The photocatalytic reaction unit 3 of this embodiment does not have the fluororesin tube 40, and therefore differs from that of the first embodiment in that the photocatalyst layer is applied to the light guide substrate 9 instead of the tube 40. However, other configurations are the same. For this reason, the drawing of the third embodiment is omitted. The photocatalytic reaction unit 3 of this embodiment does not show the effect of the tube 40 described above, but the light component that has been totally reflected and hardly contributed to the photocatalytic reaction in the past is radiated from the outer peripheral surface 11 by the annular groove 14. Therefore, an increase in light intensity and an improvement in distribution are realized as compared with the case where the annular groove 14 is not provided.

By the way, since the refractive index of titanium oxide is about 2.5 and is larger than that of quartz glass, total reflection of light does not occur when titanium oxide is attached to the light guide body 9 made of quartz glass. However, the titanium oxide photocatalyst layer must be applied to the light guide substrate 9 via a binder to ensure its adhesion strength, and such a binder has a lower refractive index than the quartz glass material. Therefore, the critical angle of total reflection regarding the outer peripheral surface 11 of the light guide base 9 also exists in the present embodiment. Therefore, the annular groove 14 acts effectively also in the third embodiment.

Next, a photocatalytic reaction device 4 (a) according to a fourth embodiment of the present invention will be described with reference to FIG. This photocatalytic reaction device 4 (a) includes a photocatalytic reaction unit 101 having the same function as the photocatalytic reaction unit 1 of the first embodiment, and a casing 70 that forms a flow passage 71 of a fluid to be processed. Yes.

The casing 70 includes a cylindrical main body 72 in which a fluid flow passage 71 is formed, a cap 74 that defines a light source housing 73 in which the light source 120 and the lens 130 of the unit 101 are disposed, and the flow passage 71 and the light source. It has a disc-shaped separating plate 75 that separates the accommodating portion 73 from each other, and the cap 74 and the main body 72 are fixed at a flange portion (not shown). An electric cable 76 is led out from the cap 74.

The main body 72 is provided with a liquid inlet 77 on the upper left side in FIG. 5 and a fluid outlet 78 on the lower left side. The separator 75 also has a function of positioning and holding the light guide 110 of the photocatalytic reaction unit 101 at the top.

The photocatalytic reaction unit 101 includes a light source 120 and a lens 130. The lens 130 is composed of a biconvex lens, and is positioned and held by a spacer 79. The light source 120 is mounted on a substrate 123 to which the light emitting diode 121 is fixed, and has heat radiation fins 124.

In the photocatalytic reaction device 4 (a) of this embodiment, the distance between the photocatalytic layer of the photocatalytic reaction unit 101 forming the flow passage 71 and the inner peripheral surface of the casing 70 is preferably 1.5 mm or less. The casing in the photocatalytic reaction device 4 (a) of this embodiment is cylindrical, but the geometric shape of the cross section of the casing is not limited to a circle and can be any shape, for example, An elliptical shape and an arbitrary polygonal shape such as a triangle, a square, a rectangle, a pentagon, etc. are possible. It means the shortest distance from the distance to the inner peripheral surface. By configuring the reaction device in this way, it is possible to greatly improve the treatment effect (decomposition effect) due to decomposition of organic substances in the fluid, oxidation-reduction reaction, and the like.

A fluid containing fine particles such as organic substances to be processed passes through a flow passage 71 surrounded by the photocatalytic reaction unit 101 and the casing 70, but the particles in the fluid are efficiently decomposed. Requires more particles to contact the photocatalytic layer.
On the other hand, in order to increase the processing amount per unit time, it is desirable to increase the flow rate within a range in which the decomposition effect can be maintained. From this point of view, in order to obtain the relationship between the decomposition effect and the distance between the photocatalyst layer of the photocatalytic reaction unit 101 and the inner peripheral surface of the casing 70, the reactor 3 size in which the casing inner diameter was changed was examined by changing the flow rate. Went.
Here, the photocatalyst reaction unit 101 has an outer diameter of 6.6 mm and the distance between the photocatalyst reaction unit 101 and the inner peripheral surface of the casing 70 is 0.60 mm, 1.25 mm, and 1.65 mm. The photocatalytic reaction apparatus was manufactured, and the photocatalytic reaction apparatus was connected to a pump with a tube and the treatment fluid was circulated to confirm the decomposition effect. A methylene blue solution adjusted to a constant concentration is used as the treatment solution, and the decomposition effect is expressed as the rate of change in the concentration of methylene blue per pass (per pass) obtained by the following formula. Is shown in Table 1 and FIG.

Table 1
FIG. 6 shows the relationship of the results shown in Table 1 with the vertical axis representing the methylene blue concentration change rate and the horizontal axis representing the distance between the photocatalyst layer of the photocatalytic reaction unit 101 and the inner peripheral surface of the casing 70. FIG. It can be seen that the decomposition effect per pass is greatly improved when the distance between the layer and the inner peripheral surface of the casing is 1.5 mm or less. Looking at the influence of the flow velocity on the decomposition effect at this time, there is almost no difference in the decomposition effect due to the flow velocity. In this photocatalytic reaction device, the distance between the photocatalyst layer and the inner peripheral surface of the casing 70 is more effective than the fluid flow velocity. It can be confirmed that it has a great influence.

The photocatalytic reaction device 4 (a) according to the present embodiment can be arranged in parallel with the required number corresponding to the amount of fluid to be processed, and the fluid is circulated once through the flow passage 71. The processing capacity of the liquid at the time can be adjusted by changing the length of the light guide 110.

In the photocatalytic reaction device according to the fourth embodiment of the present invention, a plurality of photocatalytic reaction units 101 may be arranged in the casing 70. A photocatalytic reaction device 4 (b) in which a plurality of photocatalytic reaction units 101 are arranged in a casing 70 will be described with reference to FIGS. This photocatalytic reaction device 4 (b) includes a plurality of photocatalytic reaction units 101 having the same function as the photocatalytic reaction unit 1 of the first embodiment, specifically, 451 sets of fluids to be processed. And a casing 70 that forms a flow passage 71. In FIGS. 7 to 9, for ease of understanding, 13 sets of the photocatalytic reaction units 101 are housed in the casing 70, and the outer diameter of the light guide 110 is also schematically drawn.

The casing 70 includes a cylindrical main body 72 in which a fluid flow passage 71 is formed, a cap 74 that defines a light source housing portion 73 in which the light source 120 and the lens group 130 of the unit 101 are disposed, and the flow passage 71. It has a disc-shaped separating plate 75 that separates the light source housing 73 from each other, and the cap 74 and the main body 72 are bolted to a flange portion (not shown). The cap 74 has a lower half formed in a cylindrical shape, and an upper half formed in a hollow truncated cone shape, and an electric cable 76 is led out from a lower cylindrical portion.

The main body 72 is provided with a liquid inlet 77 on the upper left side in FIG. 7 and a fluid outlet 78 on the lower right side. The separator 75 also has a function of positioning and holding the light guide 110 of the photocatalytic reaction unit 101 at the top. In the flow path 71, ten substantially disc-shaped support plates 79 that support the light guide 110 between the inlet 77 and the outlet 78 are also provided. These support plates 79 not only support the light guide 110 but also have a function of causing the liquid from the inflow port 77 to the outflow port 78 to meander to increase the contact time with the photocatalyst layer.

Also in this embodiment, each of the plurality of photocatalytic reaction units 101 includes a light source 120 and a lens group 130, and the lens group 130 is a first lens 131 that is a biconvex lens and a second lens 132 that is a hemispherical lens. It is composed of However, a plurality of first lenses 131 are integrally formed as a first collective lens 131a on a common base material made of the same material as the lens, and the second lens 132 is similarly formed on a common base material. A plurality of lenses are integrally formed as the second collective lens 132a. A plurality of light emitting diodes 121 of the light source 120 are mounted on one common printed circuit board 123. The light source 120 also has one common heat radiating fin 124.

The first collective lens 131a has a disk-like outer shape as shown in FIG. 8, which is a plan view thereof. In FIG. 8, it can be seen that the first collective lens 131a includes thirteen first lenses 131. Further, a rim portion 131b for defining a distance between the light source 120 and the second lens 132 is provided on the outer peripheral portion of the disc, and a semicircular shape that facilitates positioning with respect to the cap 74 is provided. A notch 131c is also provided.

The second collective lens 132a has a disk-shaped outer shape as shown in FIG. 9 which is a plan view projected from the light guide 110 side, and includes 13 second lenses 132 in FIG. I understand that. Further, a semicircular cutout 132c is provided on the outer peripheral portion of the disk so as to facilitate positioning with respect to the cap 74.

By configuring the light source 120 and the lens group 130 in this manner, optical axis adjustment between the light source 120, the lens group 130, and the respective light guides 110 becomes almost unnecessary, and in particular, as many as 451 guides. Assembly in the case of this embodiment in which the light body 110 is mounted is facilitated.

According to the photocatalytic reaction device 4 (b) of this embodiment, since each of the large number of light guides 110 includes the light source 120 and the lens group 130, high light coupling efficiency between the light source 120 and the light guide 110 is achieved. In addition, a desirable incident angle range of light with respect to the light guides 110 is obtained, and each light guide 110 has a large number of annular grooves 14 so that most of the light incident from the end face is emitted to the photocatalyst layer and guided. The effective length of the body 110 can be increased. As a result, a large number of elongated photocatalytic reaction units 101 can be mounted with high density, and the surface area of the photocatalyst layer is increased to increase the processing capacity.

Other Embodiments Although the cross-sectional shape of the annular groove 14 of the light guide in each of the above-described embodiments is U-shaped as shown in FIG. 2A, the shape of the annular groove 14 can be arbitrarily changed. For example, a semicircular shape shown in FIG. 2B or a shallow arc shape equal to or less than the semicircular shape shown in FIG. 2C may be used. In addition, the cross-sectional shape may have one or a plurality of corners. For example, the deep V shape shown in FIG. 10A, the V shape shown in FIG. 10B, or FIG. (C) Shallow V-shape or the like is possible.

Moreover, the annular groove does not necessarily have to make a complete circle, and may be formed partially, such as a C-shape.

Although the arrangement interval of the plurality of annular grooves 14 of the light guide in each of the above-described embodiments, that is, the pitch P, is constant, the pitch P may be changed to obtain a desired light intensity distribution.

In each of the embodiments of the photoreaction apparatus 4 (b) according to the first, second, third, and fourth embodiments described above, a light source is provided only on one end (upper) side of the light guide. However, an embodiment in which a light source is provided at the other end of the light guide as in the photoreaction device 4 (a) is also possible. As a result, the total length of the light guide can be almost doubled, and the liquid processing capacity is also doubled.

The light guide substrate in each of the above-described embodiments has a cylindrical shape, but the geometric shape of the cross section of the light guide substrate is not limited to a circle, and can be any shape, for example, , Oval and any polygonal embodiments such as triangle, square, rectangle, pentagon, etc. are possible.

Although the light guide substrate in each of the above-described embodiments has a cylindrical shape, a pipe-shaped embodiment in which the light guide substrate has an inner peripheral surface is also possible. In that case, the annular groove may be formed on the inner peripheral surface of the light guide substrate. The annular groove formed on the inner peripheral surface can diffuse and radiate the light impinging on the groove toward the photocatalyst layer.

In each of the above-described embodiments, the light guide has a cylindrical shape and the thickness thereof is constant. In addition to forming a plurality of annular grooves, the light guide is further tapered toward the tip side. A shape embodiment is also possible. By tapering the light guide in this way, it becomes possible to radiate the parallel light from the outer peripheral surface even when there are many components of the parallel light in the incident light to the light guide. It becomes possible to make the intensity and distribution of light desirable.

In the above-described embodiment, the annular groove is formed in the light guide substrate, but an embodiment in which the annular groove is formed on an intermediate layer such as a tube is also possible. The annular groove may be formed on the photocatalyst layer after the photocatalyst layer is fixed on the tube or the light guide base.

An embodiment in which the light guide has at least one continuous spiral groove instead of the plurality of annular grooves is also possible. Further, the concave portion provided in the light guide body may suffice as long as it emits at least part of the light incident from the end face to the photocatalyst layer side. For example, in addition to intermittent spiral grooves, In addition, an embodiment in which a linear groove having a predetermined length is partially formed may be used. Furthermore, as described above, when the cross-sectional shape of the light guide base is a polygon, the recess may be a linear or curved groove. These recesses can also exhibit the same optical effect as the annular groove.

In the photocatalytic reaction device 4 (b) of the fourth embodiment, the first and second lenses of each photocatalytic reaction unit are integrally formed as a common first and second collective lens. Embodiments formed as separate lenses as in the embodiment are also possible.

DESCRIPTION OF SYMBOLS 1 Photocatalytic reaction unit 9 Light guide base | substrate 10 Light guide 11 Outer peripheral surface 12 End surface 14 Annular groove 20 Light source 21 Light emitting diode 30 Lens group 31 1st lens 32 2nd lens 40 Tube 50 Sealing member 60 Lens barrel

Claims (10)

1. A light guide base having a vertical axis, an outer peripheral surface around the vertical axis, and two end faces intersecting the vertical axis, and an intermediate layer provided on or on the outer peripheral surface of the light guide base A light guide having a photocatalyst layer fixed to the light source, and a light source disposed so that light enters the light guide base from at least one end face of the light guide base. A photocatalytic reaction unit in which the light guide is inserted into a fluid to be provided, the light guide being provided so as to radiate at least a part of light incident from the end face toward the photocatalyst layer. The photocatalytic reaction unit is characterized in that the concave portion is formed continuously or partially around the longitudinal axis.
2. The photocatalytic reaction unit according to claim 1, wherein the intermediate layer is a light-transmitting tube.
3. The recess is composed of a plurality of annular grooves or at least one spiral groove, and is arranged at a constant pitch or a changing pitch with respect to the longitudinal direction of the light guide, The photocatalytic reaction unit according to claim 1 or 2.
4. The light guide has a grooveless section without grooves from the end face, and the length of the grooveless section is larger than the pitch of the annular groove or at least one spiral groove. The photocatalytic reaction unit according to claim 3, wherein:
5. The photocatalyst according to any one of claims 1 to 4, wherein a cross-sectional shape of the concave portion is any one of a U shape, a semicircular shape, an arc shape shallower than the semicircle, or a V shape. Reaction unit.
6. The photocatalytic reaction unit according to any one of claims 1 to 5, wherein the light source is disposed in proximity to or in contact with an end face of the light guide.
7. The photocatalytic reaction unit according to any one of claims 1 to 5, further comprising at least one lens disposed between the light source and the light guide.
8. Comprising one or more photocatalytic reaction units according to any one of claims 1 to 7 and a casing forming a flow path for a fluid to be treated; A photocatalytic reaction device, wherein a light guide is disposed in the flow passage.
9. 9. The distance between the photocatalyst layer fixed to the outer peripheral surface of the light guide substrate or an intermediate layer provided on the outer peripheral surface and the inner peripheral surface of the casing is 1.5 mm or less. The photocatalytic reaction device described in
10. Each of the plurality of photocatalytic reaction units includes at least one lens disposed between the light source and the light guide, and the lenses of the plurality of photocatalytic reaction units are provided between the plurality of photocatalytic reaction units. The photocatalytic reaction device according to claim 9, wherein the photocatalytic reaction device is integrally formed on a common base material.

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