JP2523980B2 - Leak detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention is a leak detecting leak in a power plant or the like using a detector whose electrical characteristics change due to adhesion of leaked liquid. Regarding a detection device.

(Prior Art) A large number of liquids such as water supply / drainage, lubricating oil, hydraulic oil, and chemicals constantly circulate in chemical plants and power plants. Even a slight leak of these liquids may cause physical or personal damage. Above all, if oils and fats such as lubricating oil and hydraulic oil and chemicals leak, there is a risk of causing a major accident such as a fire or a blunt stop. In addition, if these liquids flow out, they may cause environmental pollution. Therefore, early detection of liquid leakage is very effective in preventing these accidents.

Conventionally, as a means for detecting a leak, a method has been mainly adopted in which an observer regularly makes a patrol inspection to detect a leak.

Further, recently, as disclosed in Japanese Patent Publication No. 59-47256, a detector is laid in the vicinity of an object to be monitored, and liquid is attached to the detector to change the resistance value or the electrostatic capacity. A leak detection device has been developed that automatically detects a leak of a liquid by using a mechanical means.

The conventional leak detection device has a piping section 12 as shown in FIG.
In order to collect liquid droplets from the liquid leaked from the device, a cover 27 or a tray 26 is installed, and a spot-shaped detector 1 or a line-shaped detector that is fitted to each leak monitoring range is provided. 32
To detect droplets.

On the other hand, the leak from the oil tank 29 is detected by the dot-shaped detector 1 installed in the discharge pit 30. The change in the detection value obtained by the point-shaped detector 1 or the line-shaped detector 32 is grasped by the judgment unit 31 through the signal line to judge the occurrence of leakage, and the leakage is detected.

In addition, the Japanese Patent Application No. 46-61213 (No. 48-20437) is
Disclosed is a water detection device in which a through hole is provided in a flexible sheet-like insulating material such as a mylar film, meandering electrodes are formed on the surface of the insulating material, and a hygroscopic material is sandwiched between the insulating materials. .

Further, Japanese Patent Laid-Open No. 50-139785 discloses a leak detection device in which a detection device provided with a small hole is installed on the entire lower surface of a device to be leak-detected.

In addition, Japanese Utility Model Sho 61-126462 (Japanese Utility Model Sho 63-33439)
In order to detect the leakage of the welded part of the inner pipe of the double pipe, install a perforated cylinder between the inner pipe and the outer pipe, install a detector inside it, and perform replacement and inspection. Discloses a leak detection device provided with a bottom plate.

(Problems to be Solved by the Invention) The conventional patrol inspection of a surveillance staff member is regularly carried out at regular intervals. Therefore, there is a problem that leak detection by patrol inspection lacks real-time property. For example, it is difficult to detect a sudden leak that occurs between one patrol inspection and the next patrol inspection and expands in a short time in real time. In addition, it is difficult to visually inspect complicated parts such as piping, and their reliability varies from person to person. In addition, the patrol inspection must be performed early in the morning and late at night, which imposes a heavy burden on the observer. Moreover, a fire may be caused by leakage of oil or the like, or a high-pressure fluid may be blown out, which may endanger the surveillance staff.

Although such a problem can be solved by using a leak detection device as shown in FIG. 11, there is a drawback that the detector is weak against external force.

In general, leakage often occurs in a place where pipes and equipment are complicated or in a dark place, and there is a high possibility that an observer may accidentally step or kick during patrol inspection. Also during maintenance and inspection,
Tools may fall. Tray as shown in Fig. 11
When the detector 26 and the cover 27 are installed and the detector 1 is mounted therein, the monitoring point is covered, which hinders visual monitoring.

Further, once the leaked liquid adheres to the detector, it is difficult to recover the state before the leaked liquid adheres. Therefore, if the leaked liquid adheres to the detector, it is necessary to replace the detector. However, when the tray 26 and the cover 27 are used as shown in FIG. 11, there is a problem that the detector 1 cannot be easily replaced.

Also, the device of Japanese Utility Model Application No. 46-61213 (Japanese Utility Model Application No. 48-20437) is used in a place where there is a risk of being stepped on by a supervisor, such as a plant, and no consideration is given to replacement of the detector. Not done.

Further, since the device disclosed in Japanese Patent Laid-Open No. 50-139785 is installed on the entire lower surface of the device or the like, it is almost impossible to replace the detector, and the detector cannot be additionally installed later. .

In addition, Japanese Utility Model Sho 61-126462 (Japanese Utility Model Sho 63-33439)
Since it is supposed to be used in the special situation of a pipeline, it was not a structure that could be easily installed on the floor of the plant. In addition, a configuration in which a protective box is provided to cover the detector is also conceivable, but it has a drawback that the detection capability is poor, and if it is so, maintainability is also poor.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a leak detection device that is strong against external force, can perform reliable detection with high sensitivity, and can be replaced quickly and easily. To provide.

[Structure of Invention]

(Means for Solving the Problems) In order to achieve the above-mentioned object, in the present invention, a detector for detecting a change in electrical characteristics caused by the adhesion of leaked liquid, and a liquid leaked by embedding the detector And a bottom plate installed on the object to be detected, and a box and a perforated plate that are provided on the top of the bottom plate and that constitute the side surface and the top surface and that are removable from the bottom plate. The depth and the height are shorter than the width, the detector and the liquid leakage transmitting material are stored, and the liquid leakage transmitting material is detected in the upper part and the perforated plate that allows the leaked liquid to pass therethrough. It has a protective box having a mechanism for closely contacting, a spring member provided in the protective box for closely contacting the detector and the liquid leakage transmitting material, and a terminal block for connecting a signal line to the detector. Providing leak detection device To do.

(Operation) According to the leak detection device of the present invention, the leaked liquid that has fallen on the protective box adheres to the detector through the holes of the perforated plate, and the leaked liquid that has fallen around the protective box is monitored. It reaches the detector through the leak transmission material that is in close contact with the target. That is, it is possible to quickly detect the leaked liquid that has directly dropped onto the protective box and the leaked liquid that has dropped around the protective box.

In addition, by making the detector and the liquid leakage transmitting material come into close contact with each other by the load of the spring attached to the protective box, good detection can always be performed. Moreover, since the detector and the liquid leakage transmitting material are housed in the protective box, it is possible to prevent the detector from being damaged by an external force or a falling object.

Further, since the protective box can be disassembled and the terminal block is provided, the liquid leakage transmitting material and the detector can be easily inspected and replaced.

(Example) The Example of this invention is described with reference to drawings.

FIG. 1 is a perspective view of a first embodiment of the present invention, and FIGS. 2 and 3 are sectional views taken along lines II-II and III-III of FIG.

In FIGS. 1 to 3, the detection unit includes a detector 1 and a liquid leakage transmission material 2 including the detector 1. The protection box 3 comprises a bottom plate 4, a box 5 and a lid 6, the bottom plate 4 and the box 5 are fixed by stud bolts 16 and nuts 15, and the lid 6 and the box 5 are fixed by screws 20. In addition, the bottom plate 4 has bolts 25 attached to the monitored object 7.
Fixed at. A plate-shaped spring 8 having a relatively small spring constant is fixed to the lid 6 with a screw 20 and a nut 15, and when the lid 6 is attached, a leak is caused between the spring 8 and the bottom plate 4. The liquid transfer material 2 is sandwiched. The end 2a of the liquid leakage transmission material 2 is pressed against the edge of the box 5 and is brought into close contact with the monitored object 7. A lead wire 11 from the detector 1 is connected to a terminal block 9 in a terminal box 10 attached to the protective box 3 and connected to a signal processing unit (not shown).

By the way, when a leak occurs and the leaked liquid falls on the surface on which the protective box 3 is attached, the leaked liquid is leaked onto the surface on which the protective box 3 is attached by the edge of the box 5 and the leak transmission material 2 is pressed. Is absorbed by and is guided to the detector 1. Further, when the leaked liquid directly drops into the protective box 3, the leaked liquid passes through the holes of the lid 6 of the perforated plate. Further, the leaked liquid enters the protective box 3, is absorbed by the liquid leakage transmitting material 2, and is guided to the detector 1.
Therefore, both the liquid that has fallen around the protective box 3 and has been transferred and the liquid that has directly dropped into the protective box 3 can be immediately introduced into the detector 1, and quick detection is possible. Further, the load of the spring 8 attached to the lid 6 causes the leak transmission of the detector 1 and the leak transmission of the detector 1 even if the leakage transmitting material 2 is expanded or contracted or the protective box 3 is slightly deformed due to the temperature change in the daytime, the seasonal temperature change, the humidity change or the secular change. There is no gap between the materials 2, and reliable detection is possible.

Further, since the detector 1 and the liquid leakage transmitting material 2 are housed in the protective box 3, even if the observer mistakenly steps, kicks, or drops tools or the like during maintenance and inspection, the box 5 and the lid are closed. The detector 6 and the liquid leakage transmitting material 2 can be protected by 6.

By the way, the detector 1 and the liquid leakage transmitting material 2 need to be replaced once the liquid leakage is attached, because it is difficult to recover before the attachment. Further, it is desirable that the detector 1 and the liquid leakage transmitting material 2 are regularly replaced in consideration of deterioration over time. When replacing the detection unit consisting of the detector 1 and the liquid leakage transmitting material 2, first remove the lid 6, then remove the lead wire 11 from the terminal block 9, and remove the box 5 from the detector 1 and the liquid leakage transmitting material 2. The detector can be easily removed. When installing a new detector, it can be easily installed by reversing the removal procedure.

As described above, in the present embodiment, the detector 1 and the liquid leakage transmitting material 2 are protected from the external force, and the detector 1 and the liquid leakage transmitting material 2 are brought into close contact with each other for reliable detection. Since the base 9 is integrated, the detector 1 and the liquid leakage transmission material 2
Can be replaced quickly and easily.

Next, a method of monitoring a pipe joint using the leak detection device of the present invention will be described with reference to FIG.

As shown in FIG. 4, the protective box 3 is fixed to the upstream and downstream pipes 12 of the pipe joint 12 by U bolts 13, and the protective box 3 is attached so as to be located below the pipe joint 12. Protective box 3
Although the structure of the detection unit 25 is the same as that of the above-described embodiment, only the leaked liquid that falls directly into the protective box 3 from the pipe joint 12 is detected, so in this embodiment, the liquid leakage transmission material 2 is provided outside the protective box 3.
You don't have to stick out the end of.

According to the present embodiment, it is not necessary to attach a large-scale tray, so that it is easy to attach and detach, and since the entire pipe joint is not covered, it does not obstruct the patrol inspection by the observer.

FIG. 5 is a perspective view of the second embodiment of the present invention, and FIG.
It is sectional drawing which follows the VI-VI line of a figure.

The present embodiment is a case where it is installed in a place where the external force is relatively small. The difference from the first embodiment is that the lid 6 and the box 5 are eliminated,
Instead, use mesh plate 17 for stud bolts.
The point is that it is fixed to the bottom plate 4 with 16 and nuts 15. Since the other structure is the same as that of the first embodiment,
The description is omitted. The same applies to the following examples.

The mesh-shaped plate 17 is slightly larger than the bottom plate 4, and the edge portion of the mesh-shaped plate 17 is bent downward so that the end of the liquid leakage transmitting material 2 can be brought into close contact with the detection target 7 (floor surface or the like). In addition, the shape of the mesh plate 17 above the detector 1 is changed to the detector 1
The same effect as that of the spring 8 of the above-described embodiment can be obtained by molding so that the liquid leakage transmitting material 2 and the liquid leakage transmitting material 2 are closely attached.

According to the present embodiment, since the structure is simple, it is inexpensive, and it is possible to detect the leaked liquid quickly and reliably in a place where the external force is relatively small and there are few falling objects.

FIG. 7 is a side sectional view of a third embodiment of the present invention, in which the drain reservoir 21 is assumed to have a veil shape or a trough shape, and only the outer peripheral upper portion thereof is illustrated.

As shown in the figure, the detection unit includes a detector 1 and a liquid leakage transmission material 2 that covers the detector 1. The detector is sandwiched between a hanging plate 18 and a protective plate 19 and fixed by a stud bolt 16 and a nut 15. Further, the hanging plate 18 is hung on the edge of the drain reservoir 21 so that the detecting portion is on the inside of the drain reservoir 21, and the outside of the drain reservoir is pressed and fixed by the fixing bolt 25. 10 is a terminal box.

Assuming that the height of the drain reservoir 21 is H and the length of the hanging plate 18 is l, the level when the high level alarm is output is h = H-1.

According to the present embodiment, it does not have a large-scale structure like a float type level meter generally used. Also, terminal box
Since 10 is provided, the device can be easily attached / detached and the detector can be easily replaced. Therefore, this embodiment is suitable for use as a temporary level height alarm device.

FIG. 8 is a perspective view of a fourth embodiment of the present invention, and FIG. 9 is a side sectional view of FIG.

As shown in the figure, the leak detection device of the present embodiment is a detector 1
A liquid leakage transmission material 2 covering the detector 1, a plate 22 to which the fluid leakage transmission material 2 is fixed and which is provided with a mounting base for the spring 8, and a spring 8 for closely contacting the detector 1 and the fluid leakage transmission material 2. , A plate 22 to which the detector 1 is attached is attached to one end, and an installation jig 23 for installing in a narrow space, and a terminal box 10 attached to the other end of the installation jig 23 (the tenth embodiment (See the figure).

According to this embodiment, the shape and size of the plate 22 and the liquid leakage transmitting material 2 can be fitted to a narrow place by matching the shape and size to the installation place. For example, the installation jig 23 as shown in FIG. 10 enables the installation at a place 24 where the installation work is difficult and difficult to perform.

〔The invention's effect〕

As described above, according to the leakage detection device of the present invention, by protecting the detector and the detector composed of the liquid leakage transmitting material with the protective box, it is possible to prevent the detector from being damaged due to an external force. In addition, the liquid leaked in the vicinity of the leak detection device is guided to the detector early by the end of the leak transmission material that is in close contact with the upper porous plate and the detection target, and the load of the spring installed in the protective box By closely contacting the detector with the liquid leakage transmission material, it becomes possible to detect quickly and surely without becoming undetectable. Further, the terminal block attached to the protective box makes it possible to easily replace the detection unit.

Therefore, it is strong against external force, highly accurate, and easy to maintain,
The constant monitoring of the leakage of plant equipment can be effectively realized.

[Brief description of drawings]

FIG. 1 is a perspective view of a first embodiment of the present invention, FIG. 2 and FIG.
1 is a sectional view taken along line II-II and line III-III in FIG. 1, FIG. 4 is a perspective view for explaining one example of use of the first embodiment of the present invention, and FIG. FIG. 6 is a perspective view of the second embodiment, FIG. 6 is a sectional view taken along line VI-VI of FIG. 5, FIG. 7 is a side sectional view of a third embodiment of the present invention, and FIG. 8 is a fourth sectional view of the present invention. Fig. 9 is a perspective view of an embodiment, Fig. 9 is a side sectional view of Fig. 8, Fig. 10 is a view for explaining an example of use of a fourth embodiment of the present invention, and Fig. 11 is a conventional leak detection device. It is a schematic block diagram which shows a usage example. 1 ... Detector, 2 ... Leakage transmission material, 3 ... Protective box, 4 ... Bottom plate, 5 ... Box, 6 ... Lid, 7 ... Monitored object, 8 ... Spring, 9 ... Terminal Base, 10 ... Terminal box, 11 ... Conductor, 12 ... Piping joint, 13 ... U bolt, 14 ... Plate, 15 ... Nut, 16 ... Stud bolt, 17 ... Mesh plate, 18 ... … Hanging plate, 19 …… Protection plate, 20 …… Screw, 21 …… Drain reservoir, 22 …… Plate, 23 …… Installation jig, 24 …… Narrow spot 25 …… Bolt.

Claims (1)

(57) [Claims] 1. A detector for detecting a change in electrical characteristics caused by adhesion of a leaked liquid, a leak transmitting material for embedding the detector and guiding the leaked liquid to the detector, and a detector installed on an object to be detected. A bottom plate, and a box and a perforated plate that are provided on the top of the bottom plate and that configure the side surface and the top surface and are detachable from the bottom plate, and have a height shorter than the depth and width, and the detector. A protective box that accommodates the liquid leakage transmission material and has a mechanism for closely contacting the liquid leakage transmission material with a detection target at the lower part and the perforated plate that transmits the leaked liquid, and is provided in the protective box. A leak detection device, comprising: a spring member for closely contacting the detector with the liquid leakage transmission material; and a terminal block for connecting a signal line to the detector.