JPH0247539Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a liquid leakage detection line for detecting liquid leakage.

Water, chemicals such as sulfuric acid, hydrochloric acid, crude oil, petroleum,
When storing or transporting various liquids such as gasoline and other oils, leakage can cause losses and accidents, so leaks can be detected early to prevent losses and accidents. There is a need to. Liquid leakage is generally detected using a detection line whose electrical characteristics change depending on the infiltration of liquid. Known detection wires include one in which a braided body is interposed between two conductors, and one in which two electrode wires are woven in parallel within a fiber tape with an insulator interposed therebetween.

By the way, in liquid leakage detection, there are cases where it is desired to detect the area where a liquid leak has occurred (hereinafter referred to as the liquid leakage area) at the same time as the leak detection itself, but in such cases, it is necessary to use multiple detection lines. I was getting used to it. In other words, the detection target section is divided into several sections, one leakage detection line is installed in each section, and the measuring device installed in the monitoring center and the starting end of each detection line do not detect liquid leakage. The leakage point was discovered by connecting the lines with lead wires and finding lines where the electrical characteristics had changed.

In this way, according to the conventional method, there is a problem in that multiple leakage detection wires must be installed and each leakage detection wire must be connected to the measuring device installed in the monitoring center using a separate lead wire. It was hot.

This invention aims to solve the above problem.

In order to solve this problem, in this invention, two or more electrode wires are arranged in parallel in an insulated state, and at least one of the electrode wires is divided into the number of leakage detection areas. A number of insulated wires, the number of which is equal to the number n, which is one less than the number of divisions, multiplied by the number of the divided electrode wires, are arranged over the entire length from one end of the electrode wire to the other end, and each division of the divided electrode wire is At the point, one of the insulated wires is cut to connect one end of the divided electrode wire and the other end of the insulated wire, and connect the other end of the divided electrode wire to the other end of the insulated wire. One end side is connected to each other, and all the electrode wires and insulated wires are covered with a braided body.

For example, the number of the electrode wires can be two, and one of the electrode wires can be divided into the number of leakage detection areas, so that the number of the insulated wires can be n.
It is also possible to divide both electrode wires into the number of leakage detection areas, so that the number of the insulated wires is 2×n.

The liquid leakage detection wire according to this invention configured in this way is laid at the leakage detection location, and at one end, the resistance value between the undivided electrode wire and each insulated wire or the resistance value between each insulated wire is measured. When measuring the resistance value, if a leak occurs in any of the leakage detection areas, the resistance value between the electrode wires in that leakage area will decrease, and the resistance will decrease between the electrode wire and the insulated wire or between the insulated wire. The resistance value between them decreases, and by measuring this, leakage is detected.

Hereinafter, embodiments of this invention will be described based on the accompanying drawings.

A first embodiment is shown in FIGS. 1 and 2, and as shown in FIG. 1, the detection wire ₁ consists of an electrode wire 3,
The electrode wires 3, 3' and the four wires 2 ₂ , 2 ₃ , 2 ₄ , 2 ₅ each having an insulating coating are twisted together so that the electrode wires 3' are in opposite positions, and the inner braided body 4 and the outer braided body 4 are twisted together. A braided body 5 is provided. For example, the electrode wires 3 and 3' are made of a flexible conductor made by twisting 21 annealed copper wires with a diameter of 0.18 mm, and the internal braid 4 is made of a 200-denier monofilament polyethylene thread (6 wires, 12 threads). The outer braided body 5 is formed by
It is formed by braiding (6 threads, 16 threads) with 200 denier multifilament Tetoron thread.

Moreover, this detection line 1 is 6 as shown in FIG.
It is divided into areas A ₁ , A _{2 . .} . , and the end of the electrode wire 3 and each end of the electrode wire ₃ ′ and the strands 2 ₁ , _{2 2} . ...is connected.
This resistance R ₀ becomes a dummy resistor 8, which will be described later, and when the electrode wires 3, 3' and the strands 2 ₁ ... are disconnected, the resistance between their starting ends becomes even greater, so that the disconnection can be detected. Therefore, if disconnection is not detected, it is unnecessary unless stability of measurement, which will be described later, is taken into consideration.

For the above area A ₁ ..., nth area An (n = 1 ~
5) and the boundary Pn (P ₁ , P ₂ ... of the n+1 area An+1)
...P ₅ ), the strand 2n and the electrode wire 3' are cut, and the strand 2n of the n-th area An and the electrode wire 3' of the n+1 area An+1 are cut, and the electrode wire 3' of the n-th area An is cut. The strands 2n of the (n+1)th area An+1 are connected to each other. That is, at each boundary (each dividing point) Pn, one of the strands 2 is cut, and one divided end 3a' of the electrode wire 3' and the other divided end 2b of the strand 2 are connected, respectively. , the other divided end 3'b of the electrode wire 3' and one end 2a of the strand 2 are connected, so that the so-called electrode wire 3' and the strand 2 are crossed and connected.

The liquid leakage detection line 1 of this embodiment is constructed as described above, and its function will be explained next. First, the starting end of the electrode wire 3, the electrode wire 3', the strands 2 ₁ , 2 ₂ . . . A measuring means for measuring the resistance value between them is connected to each starting end of..., and an alarm device is activated when the measuring means measures a resistance value below a predetermined value.

An example of the measuring means will be explained based on the circuit diagram shown in FIG. 3. The AC voltage from the AC power supply 6 is converted into an AC trapezoidal wave voltage by the AC constant voltage circuit 7. A dummy resistor 8 is provided at the end of the electrode wires 3, 3' to stabilize the measurement.
A trapezoidal wave voltage from the constant voltage circuit 7 is applied to the dummy resistor 8 and the reference resistor 9 connected in series. The AC voltage generated across the reference resistor 9 is converted to a DC voltage proportional to the AC voltage via a rectifier 10 and a waveform shaping circuit 11, and this DC voltage is compared with a reference voltage by an abnormality detection circuit 12. That is, if there is no leakage, the resistance value between the electrode wires 3 and 3' is approximately equal to the resistance value of the resistor 8, the DC voltage is smaller than the reference voltage, and no abnormality is detected. However, when leakage occurs, the resistance value between the electrode wires 3 and 3' decreases, and the DC voltage input to the abnormality detection circuit 12 increases and becomes higher than the reference voltage, and an abnormality is detected and the abnormality detection circuit An alarm is issued by an alarm installed at 12 or by a separate alarm means.

Note that measuring means as shown in FIG. 3 is also provided between the electrode wire 3 and the wires 2 ₁ , 2 ₂ .

In FIG. 2, when liquid leakage occurs in the first area _A1 , only the resistance value between the electrode wires 3 and 3' decreases, and it is detected that an abnormality has occurred in the first area _A1 .
Also, if leakage occurs in the second area _A2 , the electrode wire 3
Only the resistance value between the wire ₂₁ and the wire 21 decreases, and leakage in the second area _A2 is detected. Furthermore, the third and fourth areas A ₃ ,
When liquid leakage occurs at the same time in A ₄ , the resistance value between the electrode wire 3 and the wires 2 ₃ and 2 ₄ decreases at the same time, and both liquid leaks can be detected at the same time.

In the embodiment shown in FIG. 2, all the wires 2 ₁ , 2 ₂ . , the strands 2 may be left over and used as communication lines.

Next, a second embodiment of this invention will be explained based on FIGS. 4 and 5. The difference between this and the first embodiment is the structure of the strands, so there are differences due to this. Explain only.

As shown in FIG. 4, the strand 13 ₁ is formed by twisting two insulated conducting wires 13 ₁ ′, 13 ₁ ″ in pairs, and the other strands 13 ₂ , 13 ₃ . . . is formed.

As shown in FIG. 5, the detection line has six areas B ₁ ,
B ₂ ... between electrode wires 3 and 3' and each strand 1
3 ₁ , 13 ₂ , 13 ₃ , 13 ₄ , and 13 ₅ conductors are connected at their ends with resistors R′, R 1 ′, and R ₁ ′, each having almost the same resistance value.
...is connected. Also, the nth area Bn (n=1
~5) and the n+1 area Bn+1, the strand 13n and the electrode wires 3, 3' are cut, and the n-th area Bn
conductor wires 13n', 13n'' and electrode wires 3, 3' of the n+1 area Bn+1, and
3' and the conductor wires 13n' and 13 of the n+1 area Bn+1
In other words, at each boundary (each dividing point) P'n, one of the conducting wires 13', 13'' is cut, and one end of the divided electrode wires 3, 3' 3a, 3a' and the other divided end sides 13'b, 13''b of the conductor wires 13', 13'' are connected, respectively, and the other divided end sides 3b, 3'b of the electrode wires 3, 3' are connected to the conductive wire 13', 13″ split one end side 13′a, 13″a
are connected to each other.

The resistance measuring means is provided so as to be able to measure between the electrode wires 3 and 3' and between the conducting wires of each element wire 13 ₁ , 13 ₂ . Therefore, when liquid leakage occurs in the third area _B3 , only the resistance value between the conducting wires ₁₃₂ ' and ₁₃₂ '' of the strand ₁₃₂ decreases, indicating that liquid leakage has occurred in the third area _B3. Recognize.

FIG. 6 shows a third embodiment of this invention, in which four electrode wires 14... and 15 insulated wires 15... are twisted together, and a braided body 4 is attached around the outer periphery. An external braided body 5 is provided. The three electrode wires 14 are each divided into six areas,
As in the first embodiment, each of the divided electrode wires 14 is connected to the five wires 15 at respective dividing points, as shown in FIG.

In this embodiment, a leakage area is detected between the divided electrode wire 14 and the undivided electrode wire 14 in the same manner as in the first embodiment, and between the divided electrode wires 14 in the same manner as in the second embodiment. do.

Therefore, as the number of insulators increases, the distance between the electrode wires usually increases, which reduces the detection sensitivity in the event of liquid leakage, but in this embodiment, the number of electrode wires is 2 to 4. By increasing the distance between the electrode lines and arranging them evenly, the distance between the electrode lines becomes narrower, thereby preventing the decrease in the distance between the electrode lines.

In the above embodiments, the threads constituting the internal braided body 4 are not limited to polyethylene threads, but may be made of non-hygroscopic synthetic fibers such as polyethylene, polypropylene, Tetron, nylon, etc.
Moreover, a monofilament type is preferable.

Further, the yarn constituting the external braided body 5 is preferably one having a liquid-absorbing structure such as a multifilament yarn or a spun yarn that easily conducts liquids such as water through capillary action, and the material thereof is not particularly limited. Further, it is preferable to use an annealed copper stranded wire as the conducting wire in the strand, but it goes without saying that the conductive wire is not limited to this.

In addition, the braided body is shown as having two layers of an internal braided body and an external braided body, but it is also possible to omit either the internal braided body or the external braided body, but it is possible to omit either the internal braided body or the external braided body. Therefore, it is desirable to be able to detect liquid leakage reliably without malfunctioning even in high humidity conditions. The number of electrode wires and insulated wires may be appropriately selected depending on the number of required leakage detection areas and the number of communication circuits, and the size and shape are not limited. Furthermore, the insulating coating material may be any commonly used material such as rubber or plastic, but it must have the ability to insulate between the electrodes when it is interposed between the electrode wires, so it has electrical properties such as insulation resistance. It is desirable to have excellent physical properties such as non-hygroscopicity, heat resistance, etc.

Furthermore, in addition to the insulating coated strands, an insulating string may be disposed within the braided body as necessary.

Furthermore, the above-mentioned measuring means may have one AC power source 6 and one constant voltage circuit 7, and the same number of detection circuits after the resistor 9 as the number of detection areas, or may have one measuring means and one detection area to be measured. Alternatively, the detection may be performed by sequentially switching between the two.

This invention is constructed as described above, and the detection area is divided by the liquid leakage detection line itself, so there is an advantage that the liquid leakage area can be easily detected simply by laying the detection line.

[Brief explanation of drawings]

Figure 1 is a sectional view showing an example of this invention, Figure 2 is a wiring diagram showing an example of how Figure 1 is used, Figure 3 is a circuit diagram showing an example of resistance measurement, Figures 4 and 6 are FIG. 5 is a sectional view showing another example of the invention, and FIG. 5 is a wiring diagram showing an example of use of FIG. 4. 1...Detection wire, 2 ₁ , 2 ₂ ... Element wire, 3, 3'...
... Electrode wire, 4 ... Internal braided body, 5 ... External braided body, 6 ... AC mains source, 7 ... Constant voltage circuit, 8, 9
... Resistor, 10 ... Rectifier, 11 ... Waveform shaping circuit, 12 ... Abnormality detection circuit, 13 ₁ , 13 ₂ ... Wire, 13 ₁ ′, 13 ₁ ″, 13 ₂ ′, 13 ₂ ″ ... Conductor, 1
4...Electrode wire, 15...Element wire.

Claims (1)

[Claims for Utility Model Registration] (1) Two or more electrode wires 3, 3' are arranged in parallel and insulated, and at least one of the electrode wires 3, 3' is connected to the leakage detection area A, The number of insulated electric wires 2, 1 is divided into the number B, and the number n is one less than the number of divisions multiplied by the number of the divided electrode wires 3, 3'.
3', 13'' are arranged over the entire length of the electrode wires 3, 3' from one end to the other end, and at each dividing point pn, p'n of the divided electrode wires 3, 3',
One of each of the insulated wires 2, 13', 13'' is cut to separate the divided one end sides 3a, 3a' of the electrode wires 3, 3' and the insulated wires 2, 13', 1.
3'' divided other end sides 2b, 13'b, 13''b are connected respectively, and the divided other end sides 3b, 3'b of the electrode wires 3, 3' are connected to the insulated covered electric wires 2, 1.
3', 13'' one end sides 2a, 13'a, 13''a are connected respectively, and all the electrode wires 3, 3' and insulated wires 2, 13', 13'' are connected to the braided body 4,
5. A leakage detection wire coated with 5. (2) In addition to using two electrode wires 3 and 3',
Liquid leakage detection according to claim (1) of claim 1, characterized in that one of the electrode wires 3' is divided into the number of liquid leakage detection areas, so that the number of the insulated wires 2 is n. line. (3) In addition to using two electrode wires 3, 3',
The two electrode wires 3, 3' are divided into the number of leakage detection areas, and the insulated wires 13', 13'' are divided into 2×n
A liquid leakage detection line as set forth in claim (1) of the utility model registration claim, characterized in that the line is made into a book.