JPS58102904A - Underwater natural lighting device - Google Patents

Abstract

PURPOSE:To introduce effectively the sunbeams into the sea, by floating a hollow pipe body which is covered with light transmitting materials at its both ends and a high light reflection factor secured on its inner wall surface along with the specific gravity set generally at approximately 1 and its heat part above the surface of the sea. CONSTITUTION:The inner wall surface 2 of a hollow light guide pipe body is formed with a plastic film vapor-deposited with aluminum or a thin mirror, etc. in order to secure a high light reflection factor. Both ends of the pipe body 1 are covered watertight with light transmitting covers 3A and 3B, and a wiper 14 is attached to the lower edge 3A. The pipe body 1 contains an inner pipe 10 and an outer pipe 11. The ballast 13 for weight controll, etc. is filled between both pipes 10 and 11 to set the apparent specific gravity approximately at 1, and a float 4 is provided at the place near the top of the pipe body 1. An anchor 5 is attached to the lower end of the pipe body 1 with a chain. Then the pipe body 1 is floated in the sea with its head part above the surface of the sea. As a result, the sunbeams are led effectively into the sea and then applied suitably to an ocean ranch.

Description

[Detailed description of the invention] The present invention relates to an underwater lighting device suitable for marine farms and the like.

It is known that introducing sunlight into seawater or lake water significantly promotes the growth of fish and seaweed, but the transparency of seawater and lake water is decreasing year by year due to pollution. The depth reached is gradually becoming shallower.

On the other hand, for the purpose of securing a stable supply of food resources, it has been proposed to build artificial marine life breeding facilities, so-called ocean farms, on the seabed at depths of io-cooom, where fish and seaweeds can most easily grow. When building a seabed, it is essential to artificially guide sunlight to the ocean floor.

As a means of guiding sunlight to the ocean floor, a light guide cable made up of a large number of optical fibers has been proposed, but since the amount of light guided by each optical fiber is negligible, it is not practical for marine farms. This equipment requires a huge number of optical fibers, and in order to obtain a sufficient amount of light on the seabed, it is necessary to use highly transparent optical fibers with extremely low light absorption loss, which makes the equipment extremely expensive. There is a problem with becoming.

The present invention solves the above-mentioned problems and provides an underwater daylighting device that can efficiently guide sunlight to a deep position with inexpensive equipment.

In the device of the present invention, the inner wall surface of the hollow tube is made into a reflective surface with a high tip, and both ends thereof are closed with translucent covers. is configured by holding it in place.

According to the above device, sunlight that enters from the end of the tube that protrudes above the water surface is repeatedly reflected on the inner wall of the tube, reaches the bottom end, and is emitted from there to illuminate a predetermined location such as the ocean or the seabed.

According to the above device, unlike an optical fiber, the introduced light passes through the gas inside the hollow tube, so the transmission loss of the light is extremely small compared to when passing through a solid such as glass, and the inner diameter of the optical path is very large. Since the number of reflections can be reduced, the reflection loss is correspondingly small.

Furthermore, the structure of the above-mentioned pipe is extremely simple, and a single pipe can irradiate a very wide range of sunlight.As a result, equipment costs are low, making it a practical and large-scale facility for growing aquatic organisms. It is useful as an underwater lighting device in large-scale applications.

In the present invention, specific means for making the inner surface of the tube a highly reflective surface include a method of attaching a highly reflective film material such as a plastic film coated with aluminum to the inner wall surface of the tube, and a method of attaching a highly reflective film material such as a plastic film deposited with aluminum to the inner wall surface of the tube, a method of attaching a metal such as silver or aluminum to the inner wall surface of the tube. Various methods can be used, such as forming a thin film by plating, vapor deposition, etc., or attaching a thin mirror to the inside of a glass substrate with a thickness of 1/2 mm or less. This varies depending on the application and conditions such as the depth of illumination water, but it cannot be absolutely specified, but if the tube is too thin, there will be a lot of reflection loss and a very large number of tubes will be required to obtain the desired illuminance, which is an advantage of the present invention. In general, it is desirable to have a pipe diameter of 10 (3 m or more) because the pipe diameter is low, and for large-scale facilities such as marine farms, it is practical to have a pipe inner diameter of 30 am or more.

According to the research of the present inventor, the value obtained by dividing the length of the light guide tube by its inner diameter (in the case of a square pipe, the short side length) is taken on the horizontal axis, and the number of people []
The graph in Figure 1 shows the relationship between the two using the reflectance of the inner surface of the tube as a parameter, with the solar radiation heat amount at the end being 100 and the ratio of the solar radiation heat amount (K cal/- h) at the outlet end being the vertical axis. become that way.

In the same graph, curve a shows the measurement results for a pipe line lined with commercially available m/m thick glass stirrup (reflectance of about 7j%), and the short side is so that the graph can be drawn! When the pipe is made into a rectangular pipe shape of OCm, and the length of the pipe is 10 m or more, the amount of sunlight at the outlet end will be approximately 20% of that at the inlet end.

b is a commercially available aluminum vapor deposited film (reflectance is approximately 1%)
In this case, the ratio of the length of one arm to the inner diameter of the pipe is
In this case, the light emission ratio becomes about -0%, and the solar light transmission efficiency becomes better than in case a above.

C shows the case where a thin plate mirror with a glass substrate thickness of Jm7m or less is attached inside.In this case, the reflectance is 13 or more, and when the ratio of pipe length to pipe inner diameter is 30, the emission rate is as high as 30%. becomes. That is, when a square pipe with a square cross section of 1/2 m square is used as the light guide tube of the device of the present invention, even if the pipe length is JOm, more than 30% of the sunlight received on the water surface can be irradiated into the water. If the pipe length is 20 m, sunlight can be irradiated with a high efficiency of 45% or more.

The cross-sectional shape of the light guide used in the present invention can be any shape other than a circle, such as an ellipse, a regular polygon, or a flat polygon.

In addition to being a straight pipe over the entire length, the pipe may also be a curved pipe.

As for the installation method, the upper end is placed above the water surface and the F end is placed at a predetermined position in the water, and generally it is fixed in a posture with the tube axis almost vertical, or it is floated in a fixed position. The daylighting device according to the present invention may be fixed to a rigid support member firmly erected on the bottom of a lake or the like, or the apparent specific gravity of the entire device may be made to be close to 1, as in the embodiments described below. It is also possible to make the lower end relatively heavier and float it in a substantially vertical position.

In the latter case, the structure is much simpler than the former, as the wave force does not add much load, and equipment costs are low, and it also has the advantage of being easily movable when necessary.

The F1 invention will now be described in detail with reference to embodiments shown in the drawings.

FIG. 1 is a longitudinal cross-sectional view of the daylighting device of the present invention, in which the inner surface is a straight, elongated tube with a reflective surface at the tip, and the lower end opening is covered with a transparent cover made of glass or plastic that can sufficiently withstand water pressure. 3A and close the upper end opening with a translucent cover 3B whose surface has been treated with low reflection.To install a 70-tq near the upper end of this pipe body, connect an anchor J to the lower end. With the upper end /B protruding above the water surface 6, it is floated almost vertically in sea water 7 widths, and the sunlight taken in from the top @ leap day through the transparent cover 3B is reflected downward by repeated reflections on the inner surface of the tube. The light is emitted from the lower end/A through the transparent cover 3A to illuminate the seabed.

More specifically, the tube l has an inner surface 2 as shown in FIG.
As an example, an inner tube 10 made of iron pipe with a wall thickness of 3 m 1 m and an outer diameter JjCm is arranged concentrically on the outside of this inner tube 10. It has a double tube structure with an outer tube made of iron pipe with a wall thickness of Sm/m and an inner diameter of 1100C.

A gap @/2 of a constant width is formed between the outer circumferential surface of the inner tube 10 and the inner circumferential surface of the outer tube 10. Lever gap l-2
It is filled with a granular or lump-like filler 13, such as sand, crushed stone, or powdered iron, which has a large specific gravity, is relatively inexpensive, and is easy to adjust in quantity.

In other words, the weight of the filler /3 cancels out the buoyant force of water acting on the tube l, adjusting the apparent specific gravity of the entire tube l to around 1, and by attaching a float barb near the upper end, the relative The weight on the lower end side is increased to stabilize the vertical posture, and the anchor S prevents it from being washed away.

There are no particular restrictions on the material of the outer tube l/ as long as it can withstand water pressure sufficiently and is resistant to corrosion; for example, it may be made of glass fiber reinforced plastic (FRP), metal, glass fiber reinforced concrete (CRc), etc. .

Further, the inner pipe IO can also be constructed of the same material.

A wiper'/4/ is installed on the outer surface of the translucent cover 3A at the F end to prevent contamination due to adhesion of marine organisms, etc., so that the surface of the translucent cover can be periodically cleaned by remote control from the sea. It has become.

FIG. 3 shows another example of the structure of the tubular body l.

In this example, the inner tube 10 is a square cross-section pipe, and a thin glass mirror /j with a thickness of Q, for example, 7 m/m is attached to the inner circumferential wall of the inner tube 10 to form a high-tipped reflective surface. .

For example, the inner tube 10 is made of an iron plate with a thickness of 3 m/m and has a side of 70 cm.
It is constructed with a substantially square cross section, and the wall thickness is jm/m as the outer tube l/.
Then, using a circular iron tube with an inner diameter of 10 ocm, the gap between the two was filled with powdered iron as the next filler/3.

When installing the above-mentioned double-tube structure lighting device in a deep water location, it is efficient to work according to the procedure shown in FIGS. 5(a) to 5(b).

That is, the space between the inner and outer walls of a double/double pipe unit lt, which is a combination of a relatively short inner pipe 10 and an outer pipe // having a length of about 2 m, is filled with the filler 13 so that the upper end slightly protrudes above the water surface 6. Submerge to a certain extent. Next, fill in the other inner tube 10 and the outer tube.
The upper and lower tubes are connected at the flange part /7, and the gap between the inner and outer walls of the upper tube unit is filled with filler 13 such as sand to adjust the weight to offset the buoyancy. The unit lt is completely submerged in water, and the pipe units are successively connected thereafter, so that light can be brought in even deep underwater.

FIG. 6 shows another embodiment of the invention.

In this example, instead of adjusting the apparent specific gravity of the tube body / with the filler /3 filled between the double walls as in the previous example, a weight 19 is placed near the lower end of the tube body /, for example, at the lower end of the tube body /. 7 lunge part-
For installation, a ring-shaped weight is placed on top of the circle, and a float barb is attached near the top to adjust the overall apparent specific gravity to close to 1, while also improving stability.

FIG. 7 shows still another embodiment of the present invention.

In this example, as described above, a large number of light guide tubes L each having an inner surface with a high reflective surface are placed in a supporting frame J in a vertical position at intervals from each other.
The whole body is suspended by two floats fixed to the side ends of the frame body, and an anchor J is connected near one end of the pipe body L to prevent it from being washed away. This structure is suitable for irradiating sunlight.

In addition, a condensing optical system 3 such as a convex lens, a point focus 7-Resnel lens, a linear focus Fresnel lens, and a parabolic mirror is arranged on the upper end of each light guide tube, and the condensed light is transferred to each light guide tube. I'm trying to lead it inside.

The condensing optical system 23 is driven to change its angle according to time by a sun tracking mechanism (not shown) to an angle that can most efficiently condense sunlight.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of the present invention, FIG. 2 is a cross-sectional view of the tube body of the device shown in FIG. 1, FIG. FIG. 4 is a graph showing a comparison of the performance of light guide tubes according to their reflection phases, and FIGS. FIG. 6 is a longitudinal sectional view showing still another embodiment of the present invention, and FIG. 7 is a side view showing an embodiment in which a large number of light guide tubes are installed. ／・・・・・・・・・Light guiding tube body ・・・・・・・High reflective surface, ? A, 3B...Translucent cover 44
········float! ...Anchor t...Water surface! ......Sunlight io...Inner tube l/...Outer tube 13...Filling for apparent specific gravity adjustment 2nd Chart 1 Figure 3 Cause 4 0 10 20 30 40 501
(i) The sixth cause (

Claims (1)

[Claims] ■) The inner wall surface of the hollow tube is made into a highly reflective surface, and both ends thereof are closed with transparent covers, and the upper end of the hollow tube protrudes above the water surface and the lower end is closed. An underwater daylighting device that is configured to be held in a predetermined position underwater. 2) Adjust the apparent specific gravity of the entire hollow tube body to/nearly 1
1. The underwater lighting device according to claim 1, wherein the weight at the lower end is relatively increased so that the device floats in the water in a substantially vertical position. 3) Claim 1 or 3, wherein the side wall of the hollow tube body is a hollow double wall, and the hollow portion is filled with a heavy substance such as sand to adjust the overall apparent specific gravity. Second
Underwater daylighting device as described in section.