JPS61280540A - Apparatus for detecting oil - Google Patents

Abstract

PURPOSE:To prevent the propagation of bacteria adhered to the outer periphery of an optical fiber, in a detection apparatus wherein an optical fiber is received in a protective film, by providing a string like material made of copper in almost parallel to the optical fiber. CONSTITUTION:The cross-section 12 of an optical fiber sensor is constituted by gathering a large number of optical fibers 2. Core materials 17 comprising a tension resistant material and wire materials 33 made of copper arranged in parallel to the core materials 17 are provided to both sides of the cross-section 12 and buffer materials 18 are mounted to the core materials 17 and the wire materials 33 in the longitudinal direction thereof at required intervals. A protective film 20 is adhered to each of the buffer materials 18. When thus constituted detection apparatus 21 is embedded in the side groove of an oil tank, a copper ion is dissolved in water from the wire materials 33 and the water having the copper ion dissolved therein enters the interior of the film 20 from gaps 34 to be contacted with fibers 2. Therefore, the copper ion prevents bacteria from adhering to and propagating on the outer peripheries of the fibers 2. Therefore, the detection capacity for oil of the fibers 2 in the apparatus 21 is held well over a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a detection device that is installed attached to equipment such as an oil storage tank and is capable of early detection of leaks of oil or the like.

[Prior Art] Detection of oil, etc. has been conventionally performed using optical fibers. Figure 16 shows an example of the conventional device, in which 1 is a light emitting element, 2 is an optical fiber consisting of a core 3 and a cladding 4, 5 is a light receiving element, 6 is a current voltage converter, and γ is a reference for comparison. 8 is an alarm driving device, 9 is a light indicator such as a lamp, and 10 is an audible indicator such as a buzzer.

As shown in FIG. 18, a plurality of optical fibers 2 are gathered together in an odd manner to form an optical fiber sensor cross section 12, and are bent into a U-shape as shown in FIG. A connector 13 is attached, and the U-shaped bent portion is covered with a stainless steel tube 14 and an acrylic plate 15, and a silicon mold 16 is filled inside. Further, on both sides of the optical fiber sensor cross section 12, there is a core material 17 such as stainless steel wire that can withstand tension, and a buffer material 18 such as polyethylene that softly protects the core material 17. A large number of optical fibers 2 are placed inside a protective film 20 that is bonded and has a large number of oil intrusion holes 19.
An optical fiber sensor cross section 12 consisting of the following is housed, and a detection device @21 is configured.

When in use, the detection device 21 is installed in a side gutter 2 at the confluence of a gutter 23 and a relief gutter 24, which are provided on the side of an oil tank 22 to collect and drain rainwater, as shown in FIGS. 19 and 20.
It is disposed on the 3 side and is about half immersed in water 25.

In the above configuration, when heavy oil, petroleum, etc. leak from the oil tank 22 and float on the water surface of the side gutter 23, the oil enters the inside of the protective film 20 through the oil intrusion hole 19 and adheres to the outer periphery of the optical fiber 2.

Then, oil 26 is applied to the optical fiber 2 as shown in FIG.
When the oil adheres, the oil seeps into the cladding 4, which increases the refractive index of the cladding 4, increases the amount of light 27 that leaks, and reduces the amount of light transmitted through the optical fiber 2. The rate of change over time of this decrease in permeation amount is large when oil is deposited, and becomes smaller as time passes. Therefore, by setting a standard for this rate of change using the setting signal 11 and comparing it with this standard, a warning can be issued.

[Problems to be Solved by the Invention] However, in the conventional device described above, when microorganisms adhere to the optical fiber 2 hanging down into the water 25 in the side gutter 23, the outer periphery of the optical fiber 2 becomes dirty accordingly. For example, add water to the sludge in the side gutter 23 shown in Figs. 19 and 20, insert a clean optical fiber 2 into it, and
When observed under a microscope after culturing for 0 days, a large number of attached microorganisms and microbial secretions 28 can be seen on the outer periphery of the optical fiber and fiber 2, as shown in FIG. If the optical fiber 2 becomes contaminated with microorganisms or the like, water will leak into the part where the microorganisms are attached, and the conventional device described above has a problem in that it loses its ability to detect oil.

The present invention was made in view of the above-mentioned circumstances, with the object of preventing microorganisms and their secretions from adhering to optical fibers.

[Means for Solving the Problems] The present invention provides an oil detection device in which a large number of optical fibers are housed within a protective film, and penetration portions are provided at required locations so that fluid can flow into the protective film. It has a structure in which a string-like material made of copper is provided approximately parallel to the optical fiber.

[Function] Therefore, in the present invention, since copper ions are precipitated from the copper string, the growth of microorganisms on the outer periphery of the optical fiber is inhibited.

[Example] Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

Figures 1 to 3 show an embodiment of the oil detection device of the present invention, in which a large number of optical fibers 2 are used, similar to the conventional example shown in Figure 18.
are gathered together to form an optical fiber sensor cross section 12. Although not shown, the central portion in the longitudinal direction is bent into a U-shape, and connectors 13 are attached to both ends of the U-shape via connector covers 35. There is a 17th mark on the letter-shaped bent part.
Similar to the conventional example shown in FIG. 1 and FIG. 18, it is covered with a stainless steel tube and an acrylic plate, and the inside thereof is filled with a silicon mold. In addition, on both sides of the optical fiber sensor cross section 12, a core material 1 made of a tension-resistant material such as stainless steel wire is provided.
7 and a copper wire 33 arranged side by side with the core material 17, and the core material 17 and the wire material 33 are provided with buffers such as polyethylene at required intervals in the longitudinal direction to protect the core material 17 and the wire material 33. material 18 is attached. The buffer material 18 has an intermittent structure in the longitudinal direction, and there is no material between the buffer materials 18 and 18, creating a gap 34 that allows water, oil, etc. to enter. A protective film 20 without holes is adhered to the cushioning material 18, and an optical fiber sensor cross section 12 made up of a large number of optical fibers 2 is housed inside the protective film 20 to constitute a detection device 21.

When the detection device 21 having such a configuration is immersed in the side gutter 23 shown in FIGS. Since it enters the protective film 20, it comes into contact with the optical fiber 2. Therefore, the copper ions prevent microorganisms from adhering to the outer periphery of the optical fiber 2 and multiplying. Therefore, the detection performance of the optical fiber 2 in the detection device 21 for detecting oil and the like is maintained soundly for a long period of time. For example, water and copper ions are added to the sludge in the side gutter 23 shown in FIGS. 19 and 20, and a clean optical fiber 2 is inserted into it.
When observed under a microscope after culturing at 25°C for 20 days, as shown in Fig. 4, the adhesion speed of microorganisms and microbial secretions 28 adhering to the outer periphery of the optical fiber 2 was slower than in the case shown in Fig. 21. It has become. Therefore, since the copper ions dissolved from the wire 33 can be used, the conventional problem of not being able to detect oil due to water that has climbed up due to contamination by microorganisms and secretions of microorganisms is improved. Detection is facilitated.

Oil or the like that enters the optical fiber 2 through the gap 34 causes light leakage within the core, as in the prior art.

In this embodiment, a case has been described in which the core material 17 is provided as a tensile strength material, but the core material 17 may be omitted and the copper wire 33 may also be used as the core material.

5 to 7 show other embodiments of the oil detection device of the present invention, in which soft polyethylene is coated on both sides of the protective film 20 of the conventional optical fiber sensor cross section 12 shown in FIGS. 17 and 18. A cushioning material 36 such as the above is adhered, a protective film 38 having oil intrusion holes 37 formed on the outer surface of the cushioning material 36 is adhered, and an optical fiber 2 is inserted between the protective films 20 and 38.
A copper wire rod 33 is attached in parallel with this.

In the oil detection device having such a configuration, the copper ions of the copper wire 33 are dissolved in the water that enters through the gap 34, and the copper ions delay the attachment of microorganisms to the optical fiber 2, and also prevent microorganisms from attaching to the optical fiber 2. The oil or the like that enters comes into contact with the optical fiber 2 and functions to absorb the light propagating internally as in the conventional case.

Note that it is possible to use the wire rod 33 as a tensile strength material and omit the core material 17, and it is desirable that the intervals between the oil inlet holes 19.degree. 37 be sufficiently small to be open or staggered. This is because when the holes 19.37 are in a row, when the water level is at a position where there are no holes, there will be a section of thin oil or the like that cannot reach the optical fiber 2 on the water surface.

Figures 8 to 11 show examples in which the oil intrusion holes 19.37 provided in the protective film 20.38 are arranged in a staggered manner. It is possible to detect the intrusion of oil, etc. When staggered holes are provided, the positions of the holes in the cross-sectional structure in this case are different from those shown in Fig. 6, and the protective film 20.38
If only this is illustrated, it will be as shown in FIGS. 9 to 11.

As the optical fiber 2 shown in FIGS. 1 to 3 and FIGS. 5 to 7, plastic fibers can be used in addition to various types of glass fibers. In the case of glass fiber, even if a core with a cladding is used, it is sufficiently sensitive to oil, etc.

FIG. 12 shows an example of a cross-sectional structure when the optical fiber 2 of the detection device is made of glass fiber, in which the outer periphery of the clad 4 fitted around the outer periphery of the core 3 is coated with a copper film 40 via an affinity material 39. The structure is such that the membrane 40 is not provided all over the outer periphery of the cladding 4, and a portion thereof is missing. With such a structure, when oil or the like adheres to the defective portion 41, the light that propagates internally is absorbed by the oil. In some cases, it may be possible to increase the strength of the outermost copper film 40 by using two or more layers of the compatibility material 39, but the number of layers may be selected in any manner. Furthermore, there are cases where the coating of only one layer of the film 40 becomes useless after being peeled off, so in order to withstand use even in such cases, the layer of the affinity material 39 and the layer of the film 40 are formed into a periodic multilayer structure. It is also free in terms of design.

FIG. 13 shows an example of a cross-sectional structure when the optical fiber 2 of the detection device is a plastic fiber, and the cladding 4 is omitted.

In the case of plastic fiber, unlike glass fiber, there is no risk of breakage, so the cladding 4 may be omitted.

Figure 14 is an example of the use of the oil detection device of the present invention.
Reference numeral 1 denotes a copper pipe having a number of holes 32 bored in its outer periphery, and a detection device 21 having the configuration shown in FIGS. 1 to 6 is housed inside the copper pipe 31. The pipe 31 may be cylindrical or rectangular as shown in FIG. 15, but the vertical spacing of the holes 32 must be such that the water level can reach the optical fiber 2 no matter what the water level is. It won't happen.

When a detection device having such a configuration is immersed in the side gutter 23 shown in FIGS. 19 and 20, copper ions are dissolved in the water from the copper pipe 31, and the water containing dissolved copper ions flows into the oil intrusion hole 19. The optical fiber 2 enters the protective film 20 from
Contact the outer periphery. Therefore, outside the wire 33, the pipe 3
Copper ions are also dissolved from the optical fiber 2, and these copper ions can further effectively delay the attachment of microorganisms to the optical fiber 2. Also, the protective film 2 passes through the hole 32 of the pipe 31 and the oil intrusion hole 19 of the protective film 20.
The oil or the like that has entered the core 3 comes into contact with the optical fiber 2, and acts to leak the light propagating inside the core 3, as in the case of FIG. 16.

It should be noted that the oil detection device of the present invention is not limited to the above-described embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

[Effect of the invention 1] Since the oil, etc. detection device of the present invention has the above-described configuration, the growth of microorganisms adhering to the optical fiber is prevented, and as a result, the oil, etc. detection performance is maintained well for a long period of time. This excellent effect can be achieved.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the oil etc. detection device of the present invention;
Figure 2 is a view from the ■-■ direction in Figure 1, Figure 3 is a view from the ■-■ direction in Figure 1, and Figure 4 shows microorganisms attached to the optical fiber of the detection device in Figure 1 using a microscope. FIG. 5 is an explanatory diagram of another embodiment of the oil detection device of the present invention, and FIG. 6 is a view taken in the VI-VIX direction of FIG. 5. Fig. 8 is an explanatory view of an example of the arrangement of oil intrusion holes provided in the protective film of the oil detection device of the present invention, and Fig. 9 is a view taken in the direction of IX-IX in Fig. 8. Fig. 10 is a view taken from the X-X direction in Fig. 8, Fig. 11 is a view taken from the FIG. 13 is an explanatory diagram of another example of the cross-sectional structure of the same optical fiber, and FIG. 14 is an explanatory diagram of an example of the cross-sectional structure of the optical fiber. 15 is an explanatory diagram of the pipe in Fig. 14, Fig. 16 is an explanatory diagram of an example of a conventional oil detection device, and Fig. 17 is an explanatory diagram of the sensor body used in the detection device of Fig. 16. Explanatory drawings, Fig. 18 is a view taken in the direction of the The plan view and FIG. 21 are explanatory views of microorganisms attached to the optical fiber of the detection device shown in FIG. 16, observed with a microscope. In the figure, 2 is an optical fiber, 3 is a core, 4 is a cladding, 12
17 is a cross section of an optical fiber sensor, 17 is a core material, 18 is a buffer material, 19 is an oil intrusion hole, 20 is a protective film, 21 is a detection device, 31 is a copper pipe, 32 is a hole, 33 is a wire rod, 3
4 is a gap, 36 is a buffer material, 37 is an oil intrusion hole, and 38 is a protective film. Figure 1 Figure 2 Figure 3 Figure 4 Figure 8 Figure 14 Figure 16■! 11.

Claims (1)

[Claims] 1) In a detection device for oil, etc., in which a large number of optical fibers are housed within a protective film and penetrations are provided at required locations to allow fluid to flow into the protective film, a string-like material made of copper is placed approximately parallel to the optical fibers. A position detection device for oil, etc., characterized in that: