JP2977182B2 - Luminescent carrier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a luminescent carrier used in a reaction apparatus which needs to send light into a liquid phase, and more particularly, a luminescent carrier suitably used in a bioreactor for photosynthesizing microalgae or the like. About.

[0002]

2. Description of the Related Art In recent years, the concentration of carbon dioxide (CO ₂ ) in the atmosphere has increased due to the massive consumption of fossil fuels and the deforestation of forests.
So-called global warming is becoming an international problem. One way to reduce CO ₂ emissions into the atmosphere is to use C 2
There has been proposed a method for immobilizing exhaust gas from a plant containing a large amount of O ₂ by photosynthesis. For example, exhaust gas and sunlight are introduced into a bioreactor containing a culture solution containing microalgae, and the microalgae are grown by photosynthesis.
It has been proposed to fix O ₂ as an organic substance.
As a method of guiding light to such a bioreactor, it has been proposed to collect sunlight and guide it with an optical fiber bundle or the like. Microalgae grown by this method can be used as biomass resources.

[0003]

However, in the conventional method of guiding light to a bioreactor using an optical fiber bundle or the like, light is attenuated because microorganisms and the like are innumerably suspended in a culture solution in the bioreactor. Because of its large size, the reach of light emitted from a small light source, such as the end face of an optical fiber, is very small. Therefore, the range in which photosynthesis is performed is also limited. In order to efficiently perform photosynthesis, a device that uniformly disperses and emits light from an optical fiber bundle or the like over a wide range in a culture solution is required. Hereinafter, such a device is referred to as a luminescent carrier.

Accordingly, the present invention provides a water-resistant and durable, long-time use in a culture solution suitable for culturing photosynthetic organisms in a bioreactor, and can increase the size of the light-emitting surface . It is an object of the present invention to provide a luminescent carrier with less loss of incident light . Further, the present invention provides
In addition, light is emitted while the scattered light intensity on the light emitting surface is almost uniform.
With the aim of providing a luminescent carrier that can emit
I do.

[0005]

In order to solve the problems mentioned above SUMMARY OF THE INVENTION, emission carrier of the present invention, (1) mating surfaces
Two sheets that can scatter incident light as a light scattering surface
Luminescent carrier of a sealed structure in which transparent plates are stacked,
(2) at least one end of the luminescent carrier is connected to a light source;
It is a light incident part for receiving light of
Luminescent carrier. Also, to solve the above problems
Another light-emitting carrier of the present invention is: (1) a light-emitting carrier having a closed structure in which two transparent plates are superimposed such that the superposed surface can scatter incident light as a light scattering surface,
(2) At least one end of the luminescent carrier is a light incident portion for receiving light from a light source. (3) The light scattering surface of the transparent plate has a small scattering ability near the light incident portion. The luminescent carrier is characterized in that the scattering ability increases as the distance from the light incident portion increases.

The light scattering surface of the transparent plate in the luminescent carrier of the present invention is represented by the following equation (1), where the ratio of the light scattering portion is P on the light incident side and Q is the surface farthest from the light incident portion. ,

[0007]

(Equation 2) It is necessary to satisfy the condition in order to emit light from the entire transparent plate with the scattered light intensity being substantially uniform.

In the luminescent carrier of the present invention, one end face is a light incident end face and the other end face is a light reflecting end face on which a light reflecting plate is provided, whereby light is uniformly scattered from the entire transparent plate. This is a preferred embodiment. However, it is also possible to use both end faces of the luminescent carrier as light incident end faces.

The luminescent carrier of the present invention may be composed of a connectable unit, and a plurality of the units can be connected to form a single luminescent carrier.

One example of the basic structure of the luminescent carrier of the present invention will be described with reference to a perspective view of the luminescent carrier of FIG. 1 and a sectional view of FIG. The luminescent carrier 3 of the present invention is formed such that two substantially rectangular transparent plates 1 are superimposed on each other to form a hermetically sealed structure. The periphery of the side surface of the joint portion between the two transparent plates 1 is bonded or welded with a sealing material, an adhesive, or the like for the purpose of waterproofing. One end face of the light emitting carrier 3 in FIG. 1 is a light incident end face 4 and the other end face is a light reflecting end face 5. When light from the light incident end face 4 reaches this light reflecting end face 5, the light reaches the light reflecting end face 5. The light is reflected and returned to the inside of the light emitting carrier 3, and the incident light can be used efficiently.
Note that the light reflection end face 5 may be omitted, and both end faces may be the light incidence end faces 4. Also, the part where light is incident
Not limited to the end face of the light emitting carrier 3, the light emitting carrier 3 may be formed all around the end portion.

In the luminous carrier of the present invention, the incident light incident from the transparent window propagates through the transparent plate 1 of the luminous carrier.
Here, since the overlapping surfaces of the two transparent plates 1 are both light scattering surfaces 2 such as sand-grinding surfaces, the incident light is scattered little by little so that the scattered light from both the front and back surfaces of the luminescent carrier 3 is reduced. Can radiate.

The luminous carrier of the present invention has a hermetically sealed structure in which the periphery of the joint between the two transparent plates 1 is bonded or welded with a sealing material or the like for the purpose of waterproofing. Even if the luminescent carrier 3 of the present invention is used in a liquid phase, the liquid does not enter the light scattering surface formed at the joint portion of the two transparent plates 1, so that the light scattering surface 2 of the transparent plate 1 is wet. Thus, it is possible to prevent a situation in which the light scattering function is reduced such that the light scattering function becomes translucent. Therefore, it is possible to uniformly scatter light even when used in a liquid phase.

As a material of the transparent plate 1 used for the luminescent carrier 3 of the present invention, an optical glass or an acrylic resin having a good light transmittance is suitable. In order to perform the light scattering process on the mating surface of the transparent plate 1, a method of forming a sand surface with abrasive sand or applying a white paint may be used. When a material having a limited material size (for example, optical glass) is used as the transparent plate 1, a small light emitting carrier 3 is manufactured as a unit, and then some units are connected to a transparent adhesive. It is also possible to form a large luminous carrier 3 by connecting them.

According to experiments by the present inventors, if the light scattering ability of the light scattering surface 2 of the transparent plate 1 of the luminescent carrier 3 is made uniform, the intensity of the scattered light varies exponentially with the distance from the light source as described later. It has been clarified that the non-uniformity of the scattered light becomes extremely large since it monotonically decreases. Therefore,
In order to make the scattered light intensity uniform, the light scattering ability of the light scattering surface 2 needs to be small near the light incident end face 4 and increased as the distance from the light incident end face 4 increases.

Here, a "scattering coefficient" is defined as a numerical value indicating the light scattering ability of the light scattering surface 2 as follows. FIG. 3 is a schematic diagram showing a case where a light source is installed on one end surface of the luminescent carrier 3 having a length L. The distance from the light source is z, and the incident light intensity is I
₀ , the light intensity of the light propagating inside the luminescent carrier 3 is defined as I (z). If light of I (z) · Δz · t is scattered while the light propagates the distance z to z + Δz, t is defined as a scattering coefficient. If the scattering coefficient t is a constant value irrespective of the distance z from the light source, the scattered light intensity distribution due to scattering is given by the following equation (2):

[0016]

(Equation 3) Is represented by Since the scattered light intensity decreases exponentially with the above equation (2), it is necessary to change the scattering coefficient t by z in order to improve the uniformity of the scattered light intensity.

The change of the scattering coefficient t due to z is represented by an appropriate formula, and the following constants: Length of the luminescent carrier: Lmm Light transmittance per 10 mm thickness inside the transparent plate: T _r (0 <T _r ≦ 1) Reflection efficiency of light reflecting end face: If R ₀ (0 <R ₀ ≦ 1) is determined, the scattered light intensity distribution of the luminescent carrier in the z direction can be calculated numerically. We consider the scattering coefficient t as z
Is a quadratic expression of the following equation (3).

[0018]

(Equation 4) (Where x = z / L, A, B and C are constants), and L =
The scattered light intensity distribution was calculated for the case of 1000 mm, Tr = 0.9985, _R0 = 1.0 and 0.8. The constants A, so that the scattered light intensity distribution is nearly uniform
Calculation results obtained by optimizing the values of B and C are shown in FIGS. 4 and 5, respectively. Equations representing the change of t are given by the following equations (4) and (5).

[0019]

(Equation 5)

[0020]

(Equation 6) It is. The value of the scattering coefficient t at the light incident end face 4 (x = 0) and the light reflecting end face 5 (x = 1) is t = 0.9053 / L at the light incident end face when R ₀ = 1.0, T =
3.639 / L, and when R ₀ = 0.8, t = 0.9068 / L at the light incident end face and t = 3.8 at the light reflective end face.
350 / L.

In the luminescent carrier of the present invention, the following method can be used to change the light scattering ability of the light scattering surface of the transparent plate.

The nature of the light scattering surface formed on the transparent plate is changed. For example, if the light scattering surface is a sand surface, the roughness is changed continuously or stepwise to change the scattering coefficient (light scattering ability).

The light-scattering surface formed on the transparent plate is in a state where light-scattering portions and smooth portions are mixed, and the ratio of the light-scattering portions is changed continuously or stepwise. For example, a method of spraying abrasive sand or applying a white paint on a surface of a transparent plate with a mask having holes formed thereon can easily form a desired light scattering portion pattern. This method has an advantage that it can be implemented relatively easily as compared with the above method.

FIGS. 6 and 7 show examples of the pattern of the light scattering portion in the method of changing the light scattering ability. FIG.
In this method, the stripe width of the light scattering portion 6 is gradually increased in accordance with the distance z from the light source, and at the same time, the stripe width of the smooth portion 7 is gradually reduced. FIG. 7 shows that the area of the circular pattern of the light scattering portion 6 is gradually increased in accordance with the distance z from the light source, while the area of the smooth portion 7 is gradually reduced.

The following method is used to realize the change equation of the scattering coefficient t obtained by the above calculation by the above method. First, the scattering coefficient when the ratio of the light scattering portion 6 is 100% is experimentally obtained, and the value is set to t ₀ . Considering the case where the striped pattern of FIG. 6 is formed at a pitch of 10 mm, it is considered that the width of the light scattering portion 6 is proportional to the scattering coefficient t. The width of the portion 6 is (t / t ₀ ) × 10 m
m. The ratio of the light scattering portion 6 is P,
Assuming that Q is the light reflection end face, when the value of Q / P is obtained, the following equations (6) and (7) are obtained.

[0026]

(Equation 7)

[0027]

(Equation 8) Becomes Therefore, Q / P is only required to be approximately four.

However, according to the study of the present inventors, it has been found that the value of the above-mentioned t ₀ (the scattering coefficient when the ratio of the light scattering portion is 100%) greatly changes depending on the distance z from the light source. . Light-emitting carrier made of optical glass (size 80 x 400 mm, thickness of one side of transparent plate is 5, 10, 1)
When actually producing three types of 5 mm and the light scattering surface was a sand surface and measuring the scattered light intensity distribution (the details of the measuring method are the same as in Example 1 described later, Is shown in FIG. 12), and the obtained numerical value is shown in FIG. 8 as a graph in which the horizontal axis represents the distance z from the light source and the vertical axis represents the scattering coefficient t. In FIG. 8, the mark ● represents a luminescent carrier composed of two transparent plates having a thickness of 5 mm on one side,
▲ indicates a luminescent carrier of 15 mm in the same manner.

As shown in FIG. 8, the _value of t ₀ (the scattering coefficient when the ratio of the light scattering portion is 100%) with respect to the distance z from the light source tends to decrease monotonously. Therefore,
In designing a striped pattern, it is necessary to correct t ₀ as a function of z. As shown in FIG. 8, the value of t ₀ near the light source is 1.5 times (when the thickness of the luminescent carrier is 15 × 2 mm) to 5.0 times (when the thickness of the luminescent carrier is larger than the range of 300 mm ≦ z). It is understood that it is necessary to estimate the value as large as (when the size is 5 × 2 mm). Therefore, it is necessary to further reduce the ratio P of the light scattering portion on the light incident end face, and Q
/ P needs to be 1.5 to 5 times the calculated value (about 4 times). This is called a first correction.

Further, according to experiments by the present inventors, the ratio of the light scattering portion and the scattering coefficient t are not proportional. That is, assuming that the scattering coefficient when the ratio of the light scattering portions of the striped pattern is s is t, t / t ₀ does not coincide with s, and always t / t ₀ >
s. A luminous carrier made of optical glass having a stripe pattern with a pitch of 10 mm (a size of 80 × 400 mm,
The thickness of one side is 5,10,15mm and the width of the pick is 0.3
FIG. 9 shows the result of measuring the scattered light intensity distribution by actually producing the scattered light intensity distribution. In FIG. 9, the symbols ●, □, and ▲ indicate the same luminescent carriers as described above.

FIG. 9 shows that the deviation from the proportional relationship between t / t ₀ and s increases as the thickness of the transparent body decreases and as the width of the pick-up portion decreases. Therefore, when the thickness of the transparent body is small, it is necessary to make a correction to further reduce the width of the pick-up in the vicinity of the light source (the area where the ratio of the pick-up portion is small). This correction also works in the direction of increasing the value of Q / P. The correction amount is 1.0 times (when the thickness of the luminescent carrier is 15 × 2 mm) to 2.
About 0 times (when the thickness of the luminescent carrier is 5 × 2 mm) is required. This is called a second correction.

Summarizing the above results, the Q / P value when the luminescent carrier is thick is the optimum value around Q / P = 4 calculated, but the Q / P value when the luminescent carrier is thin is: First correction: 1.5 to 5.0 times Second correction: 1.0 to 2.0 times The maximum Q / P needs to be about 40 to 50 in consideration of the following.

[0033]

【Example】

[Embodiment 1] FIG. 10 shows a plan view of the structure of the luminescent carrier of Embodiment 1, and FIG. 11 shows a cross-sectional view thereof. FIG. 12 shows an apparatus for immersing the entire luminescent carrier of the present invention in a transparent acrylic water tank, allowing light from a light source to enter the light incident end face, and measuring the scattered light intensity distribution on the light scattering surface of the transparent plate. .

In the luminous carrier shown in FIGS. 10 and 11, an optical glass plate of 10 × 80 × 400 mm is used as the transparent plate 1, and the light scattering surfaces 2 of the two optical glass plates are put together to bond the periphery. A luminescent carrier unit was produced. Next, three units are connected as shown in FIG.
m of the luminescent carrier 3. A side plate 8 made of aluminum and having a thickness of 2 mm was adhered to the side surface of the luminescent carrier 3 to reinforce it. Adhesion around the light scattering surface 2 of each unit, connection of units, and side plates 8
An epoxy adhesive (Cemedine 1565, manufactured by Cemedine Co., Ltd.) was used for bonding.

At the end of the third unit, a thin aluminum plate (thickness: 0.1 mm) was adhered as the reflection plate 9 with the above-mentioned adhesive to form the light reflection end face 5.

A stripe pattern shown in FIG. 6 was formed on the light scattering surface 2 of the optical glass plate. The stripe pitch was 10 mm, and a paper mask was placed on the glass plate, and then a pattern was formed by spraying abrasive sand (Carborundum # 400). The width of the pick-up portion in the striped pattern is shown in Table 1 below for the first unit, in Table 2 below for the second unit, and in Table 3 below for the third unit.
Are shown below. The value of Q / P is 9.38 / 0.38 =
24.68.

The light source 11 of the light emitting carrier 3 is a linear light source (a light emitting portion having a size of 0.8 ×
60 mm). The entire luminescent carrier was immersed in a transparent acrylic water tank 10, and the light from the light source 11 was incident on the light incident end face, and the scattered light intensity distribution was measured. In addition, the thickness of the water tank wall surface sandwiched between the linear light source and the luminescent carrier is 5 m.
m.

In the apparatus for measuring the scattered light intensity distribution on the light scattering surface shown in FIG. 12, the sensor 12 for measuring the scattered light intensity distribution of the luminous carrier 3 is TQ82014 type (trade name, light receiving part, manufactured by Advantest Corporation). Size φ8.
4 mm) was used. Light intensity is displayed in W (watts). FIG. 13 is a graph showing the scattered light intensity distribution when the sensor 12 is closely attached to the glass surface and measured in the length direction. According to FIG. 13, the uniformity of the light intensity of the luminescent carrier of Example 1 is almost ± 2 excluding the strong scattered light at the connection part.
It can be seen that it is within the range of 5%.

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

[Table 3] Example 2 The structure of the luminescent carrier used in Example 2 was
This is almost the same as that used in Example 1 (FIG. 7), but without the side plate. 15 × 8 as a transparent plate
Two transparent acrylic plates of 0 × 1200 mm are combined, and the periphery thereof is an acrylic adhesive Dyne B (trade name,
(Made of emerging plastic). One end face of 30 × 80 mm to which the two transparent acrylic plates are bonded is used as a light incident end face, and a thin aluminum sheet (0.1 mm thick) is attached to the other end face with the above adhesive to form a light reflecting end face. did.

The stripe pattern shown in FIG. 6 was formed on the light scattering surface of the transparent acrylic plate. The pattern of the stripes was set to 10 mm by placing a paper mask on a glass plate and then spraying abrasive sand (Carborundum # 100). Tables 4 to 6 below show the widths of the picks in the pattern. The value of Q / P is 9.83 / 1.15
= 8.55. The light source of the luminescent carrier and the method of measuring the scattered light intensity distribution were the same as in Example 1 above. FIG. 14 is a graph showing the scattered light intensity distribution when the sensor is closely attached to the glass surface and measured in the length direction. According to FIG. 14, it can be seen that the uniformity of the light intensity of the luminescent carrier of the second embodiment falls within a range of approximately ± 20%.

[0043]

[Table 4]

[0044]

[Table 5]

[0045]

[Table 6]

[0046]

As described above, according to the luminous carrier of the present invention, light from a relatively small light source can be released into water from the luminous surface, and the water- resistant material can withstand long-term use. It has durability and can increase the size of the light emitting surface,
A luminescent carrier with less loss of incident light can be provided. Further, another luminescent carrier of the present invention has
It can be emitted with almost uniform surface scattered light intensity.
it can.

Therefore, the luminescent carrier of the present invention can be used not only in a bioreactor suitable for culturing photosynthetic organisms that emit light by uniformly dispersing light in a wide range in a culture solution, but also emit light in a liquid phase. It can be widely applied to general reactors which need to be fed (for example, a reactor using a photocatalyst).

[Brief description of the drawings]

FIG. 1 is a perspective view of an example of a basic structure of a luminescent carrier of the present invention.

FIG. 2 is a cross-sectional view of one example of a basic structure of a luminescent carrier of the present invention.

FIG. 3 is a schematic diagram showing a case where a light source is installed on one end surface of a luminescent carrier having a length L.

FIG. 4 shows the change of the scattering coefficient t due to z by the above equation (3) (where x = z / L, A, B and C are constants), and L = 10
For the case of 00 mm, Tr = 0.9985, and R ₀ = 1.0, the scattered light intensity distribution was calculated, and the values of the constants A, B, and C were optimized so that the scattered light intensity distribution was nearly uniform. The calculation results are shown.

FIG. 5 shows the change of the scattering coefficient t due to z by the above equation (3) (where x = z / L, A, B and C are constants), and L = 10
For the case of 00 mm, Tr = 0.9985, and R ₀ = 0.8, the scattered light intensity distribution was calculated, and the values of the constants A, B, and C were optimized so that the scattered light intensity distribution was nearly uniform. The calculation results are shown.

FIG. 6 shows a method of changing the light scattering ability by gradually increasing the stripe width of the light scattering portion and the stripe width of the smooth portion in accordance with the distance z from the light source. An example of a striped pattern is shown.

FIG. 7 shows a method of changing the light scattering ability by gradually increasing the area of the circular pattern of the light scattering portion according to the distance z from the light source, and at the same time, increasing the area of the relatively smooth portion. An example of a circular pattern in which is gradually reduced is shown.

FIG. 8 shows a result of measuring a scattered light intensity distribution by a measuring device shown in FIG. 12 using a luminescent carrier made of optical glass;
It is a graph in which the horizontal axis represents the distance z from the light source and the vertical axis represents the scattering coefficient t.

FIG. 9 shows the results of measuring the scattered light intensity distribution of a light-emitting carrier made of optical glass having a stripe pattern with a pitch of 10 mm, with the vertical axis representing the ratio s of the light scattering portion of the stripe pattern and the horizontal axis representing t / t. It is a graph taking ₀ .

FIG. 10 is a plan view of the luminescent carrier of Example 1.

FIG. 11 is a cross-sectional view of the luminescent carrier of Example 1.

FIG. 12: The entire luminescent carrier of the present invention is immersed in a transparent acrylic water tank, and light from a light source is incident on the light incident end face.
3 shows an apparatus for measuring a scattered light intensity distribution on a light scattering surface of a transparent plate.

FIG. 13 is a graph showing a scattered light intensity distribution of Example 1 when a sensor is closely attached to a glass surface and measured in a length direction.

FIG. 14 is a graph showing a scattered light intensity distribution of Example 2 when a sensor is closely attached to a glass surface and measured in a length direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent plate 2 Light-scattering surface 3 Light-emitting carrier 4 Light-incident end surface 5 Light-reflecting end surface 6 Light-scattering part 7 Smooth part 8 Side plate 9 Reflector 10 Water tank 11 Light source 12 Sensor

────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kenji Yamamura 2-8-11 Nishi-Shimbashi, Minato-ku, Tokyo 7th Oriental Maritime Building 8th Floor Inside the Research Institute for Global Environmental Technology (56) References JP-A-7-120623 (JP, A) JP-A-3-114878 (JP, U) JP-A-1-143013 (JP, U) (58) Fields investigated (Int. Cl) . ^6, DB name) G02B 6/00 B01J 19/12 C12M 1/00 F21V 8/00 G09F 9/00

Claims (5)

(57) [Claims] (1) An overlapping surface is provided as a light scattering surface.
Laminated two transparent plates that can scatter light
(2) at least one end of the luminescent carrier is connected to a light source
It is a light incident part for receiving light of
Light-emitting device that can scatter light from both surfaces
body. 2. A light emitting carrier having a hermetically sealed structure in which two transparent plates are superimposed, wherein (1) the overlapping surface is capable of scattering incident light as a light scattering surface, and (2) the light emitting carrier is At least one end is a light incident portion for receiving light from a light source. (3) The light scattering surface of the transparent plate has a small scattering ability near the light incident portion and is separated from the light incident portion. Both sides are characterized by having a large scattering ability
A luminescent carrier that can scatter light from the surface . 3. When the ratio of the light scattering portion in the light scattering surface of the transparent plate is P on the light incident portion side and Q is on the surface farthest from the light incident portion, the following expression is obtained. 3. The front and back of claim 1 or 2,
A luminescent carrier that can scatter light from both surfaces . 4. The light-emitting carrier according to claim 1, wherein one end face is a light incident end face, and the other end face is a light reflecting end face on which a light reflecting plate is installed .
A luminescent carrier that can scatter light from both surfaces . 5. The light-scattering device according to claim 1 , wherein the light-emitting carrier is a connectable unit, and a plurality of the units are connected. Luminescent carrier capable of.