JP6199367B2 - Non-contact alarm - Google Patents

Description

  The present invention relates to a non-contact alarm device that detects an alarm by detecting leakage in a double pipe.

  Piping facilities are required to transport chemical solutions and various processing waste liquids between devices. According to the recently introduced Water Pollution Control Law, installers of facilities that store hazardous substances should be made of materials and structures that can prevent leakage of water containing hazardous substances, or installed so that leakage can be easily monitored visually. However, double pipes are used in facilities that handle hazardous substances in order to comply with such laws and regulations.

  In general, in such a double tube structure, since the outer tube encapsulates the inner tube, it is difficult to accurately detect leakage. In order to detect, it is conceivable to install a detection member such as an electrode in the pipe and measure a change in electrical resistance due to leakage as described in Patent Document 1, but such a detection member The installation in the pipe is complicated. Furthermore, when installing a detection member in piping, the liquid used as object is limited. For example, when a specific chemical solution that is corrosive to metals is used as a target, there are cases where the detection member cannot be used because it corrodes when coming into contact with these solutions.

Japanese Patent No. 2558334

  This invention makes it a subject to provide the non-contact alarm device which can be installed easily and detects the liquid leakage in a double pipe rapidly, and alarms.

The non-contact alarm device of the present invention is an electrode pair disposed so as to at least partially face the outer peripheral surface of the detected portion provided on the outside of the outer tube of the double tube consisting of an inner tube and an outer tube, And an alarm unit that is electrically connected to the electrode pair, and that issues an alarm by detecting leakage of the liquid from the inner tube based on a change in capacitance between the electrode pair.

  According to this configuration, the liquid leakage can be detected and notified based on the change in capacitance when the liquid leakage occurs in the pipe by the opposing electrode pair installed outside the detected part of the double pipe. . In addition, since the electrode pair is disposed outside the detected portion of the double tube, construction is also easy. Furthermore, since the electrode pair does not come into contact with the liquid in the tube, corrosion or the like does not occur. Therefore, various liquid leaks can be detected and notified regardless of the type of liquid.

The detected portion is a non-metallic detection tube communicating with a T-shaped drain tube that fluidly connects the double tubes, and the detection tube prevents liquid from flowing out of the detection tube. A cock may be provided, and the electrode pair may be disposed immediately above the cock.

  Since the detection pipe is fluidly connected to the drain pipe, the leakage from the double pipe is collected in the detection pipe through the drain pipe, and the leakage can be reliably detected by this detection pipe. Moreover, since a leak can be stored by providing the cock which stops the outflow of a liquid at the other end of a detection tube, the big change of an electrostatic capacitance by storing a liquid can be caught. Furthermore, the liquid can be recovered safely even when the liquid leak to be detected is of a type for which leakage to the outside is prohibited from the viewpoint of the Water Pollution Control Law.

  The drain pipe may be formed to be inclined in a Y shape so that liquid leaking from the inner pipe is collected in the detection pipe.

  Since the leak in the double pipe is collected in the detection tube by inclining the drain pipe in a Y shape, the leak can be reliably detected and notified.

The detected part is a non-metallic detection pipe fluidly connected to the outer pipe of the double pipe, and the detection pipe has an introduction part fluidly connected to the outer pipe at one end. The cock may be provided at the other end to prevent the liquid from flowing out from the detection tube, and the electrode pair may be disposed immediately above the cock.

  Since the detection pipe is directly fluidly connected to the outer pipe, the leakage in the double pipe can be detected and notified without requiring a member such as a joint such as a drain pipe.

The detected portion is made of a non-metal, is a part of the outer tube of the double tube, and the electrode pair may be disposed so as to face each other with a lowermost part of the double tube interposed therebetween. Good.

  Since the electrode pair is arranged directly on the outer peripheral surface of the outer tube using the outer tube as a detection tube, the leakage can be detected and notified with a simple configuration without newly providing a detection tube.

  The electrode pair may be attached to a sheet member.

  By attaching the electrode pair to the sheet member, the construction of the electrode pair becomes easy. In addition, since the electrode pairs can be arranged in a certain manner, it is possible to prevent displacement of the electrode pairs during construction.

  According to the present invention, in the non-contact alarm device for detecting and notifying the leakage in the double pipe, a leak has occurred in the pipe by the opposing electrode pair arranged outside the detected part of the double pipe. The liquid leakage can be detected and notified based on the change in capacitance at the time. In addition, since the electrode pair is disposed outside the detected part of the double tube, the construction is easy.

The installation figure of the non-contact alarm device concerning a 1st embodiment of the present invention. The enlarged view of a drain pipe and a detection pipe. The partial sectional view of a drain pipe, a double pipe, and a detection pipe. The perspective view which shows a part of detector tube which has a protection structure of an electrode pair. The circuit diagram of the non-contact alarm device in the case of detecting a leak at one place. The graph which shows the change of the electric current input into a comparator by the presence or absence of liquid leakage. The circuit diagram of the non-contact alarm device in case of detecting liquid leakage at multiple locations. The graph which shows switching of the output signal of the comparator in the circuit diagram of FIG. Sectional drawing of the drain pipe of the non-contact alarm device which concerns on 2nd Embodiment of this invention. The perspective view of the double tube and detection tube of the non-contact alarm which concern on 3rd Embodiment of this invention. The perspective view of the double tube and electrode pair of the non-contact alarm device which concerns on 4th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(First embodiment)
The non-contact alarm device 1 of this embodiment shown in FIG. 1 detects a leak from the double pipe 4 collected in the drain pipe 2 and issues an alarm.

  The two double tubes 4 and 4 are fluidly connected linearly in the left-right direction by a T-shaped drain tube 2. The double tube 4 includes an inner tube 4a and an outer tube 4b surrounding the inner tube 4a. The inner tube 4a and the outer tube 4b are both circular in cross section and are arranged concentrically. A liquid such as water flows in the inner tube 4a, and the liquid is transported between devices (not shown). The double tubes 4 and 4 are made of a transparent resin material, and the internal liquid can be visually recognized.

  Referring also to FIG. 2, the drain pipe 2 has three openings 2 a to 2 c having a circular cross section. Double tubes 4 and 4 are fluidly connected to the openings 2a and 2b in the left-right direction, and a detection tube (detected portion) 12 having a circular cross section is fluidly connected to the opening 2c in the lower direction. . The drain pipe 2 is formed of a transparent resin material similarly to the double pipe 4, and the internal liquid can be visually recognized.

  With reference to FIG. 3, the connection structure in the drain pipe 2 is demonstrated. The left and right openings 2a and 2b of the drain pipe 2 have a double tube structure consisting of an inner tube 2d and an outer tube 2e for connection to the double tubes 4 and 4, while the lower opening 2c is It consists only of the outer tube 2e. Therefore, the inner tube 2d and the detection tube 12 are not in fluid communication, and the liquid in the inner tube 4a does not normally flow into the detection tube 12. However, if there is leakage from the inner tube 4a to the outer tube 4b, the leakage flows into the detection tube 12 through the outer tube 4b.

  Connection in the drain pipe 2 is made by inserting the double pipes 4, 4 and the detection pipe 12 into the openings 2 a to 2 c of the drain pipe 2. The inner pipe 2d and the outer pipe 2e extending in the left-right direction of the drain pipe 2 are formed slightly larger than the diameters of the inner pipe 4a and the outer pipe 4b of the double pipes 4 and 4, respectively. The tube 2 can be inserted. Similarly, the outer pipe 2 e extending downward from the drain pipe 2 is formed slightly larger than the diameter of the detection pipe 12, and the detection pipe 12 can be inserted into the drain pipe 2. The inner pipes 4a and 4a of the double pipes 4 and 4 protrude from the outer pipes 4b and 4b, respectively, in order to facilitate connection with the drain pipe 2. Correspondingly, both ends of the inner pipe 2d of the drain pipe 2 are accommodated in the outer pipe 2e. The connection by insertion is completed in a state where the end surfaces of the tubes 4 a, 4 a, 12, 4 b and 4 b are in contact with the contact surfaces 2 f to 2 j formed over the inner periphery of the drain tube 2.

  The detection tube 12 has a circular cross section and is formed of a transparent resin material so that the liquid inside can be visually recognized. One end of the detection tube 12 is fluidly connected to the drain tube 2, and a cock 14 for preventing the liquid from flowing out of the detection tube 12 is provided at the other end. The cock 14 is provided with a handle 14a. By turning the handle 14a to open and close the cock 14, the outflow of liquid from the other end of the detection tube 12 can be allowed or blocked. A copper foil electrode pair 16 is disposed (attached) immediately above the cock 14 so as to face the outer peripheral surface of the detection tube 12. However, the material of the electrode pair 16 is not particularly limited as long as it is made of a conductive metal. Changes in capacitance can be detected by the electrode pair 16 attached to the outer peripheral surface of the detection tube 12. Further, by arranging the electrode pair 16 immediately above the cock 14, it is possible to quickly detect a change in capacitance due to the accumulated liquid. The arrangement of the electrode pair 16 shown in FIG. 1 and FIG. 2 is illustrated with a protective structure for noise reduction described later omitted for clarity of explanation.

  As shown in FIG. 4, a protection structure for reducing noise is actually provided on the electrode pair 16. That is, the insulating tape 17a is wound on the electrode pair 16, the metal shield electrode 17b is disposed on the insulating tape 17a, and the resin protective tape 17c is wound on the shield electrode 17b. By doing in this way, it is suppressed that a noise mixes into the electric current which flows into the electrode pair 16 according to the change of an electrostatic capacitance, and the detection accuracy is improved.

  The electrode pair 16 is electrically connected to an alarm device body (alarm unit) 20 through a cable 18 (see FIG. 1). The cable 18 employs a shield structure having an electric wire covered with a copper tape or a resin tape and a shield wire connected to the shield electrode 17b. By adopting a shield structure, the influence of noise can be reduced, and equipment can be connected if it is about 10 m to 20 m.

  As shown in FIG. 1, the alarm device main body 20 includes an electronic device that constitutes an electronic circuit described later, and an alarm lamp 20a on the outer surface. The alarm device body 20 determines whether or not to issue an alarm based on the measurement signal.

  According to this configuration, the leaked liquid in the double pipe 4 is collected via the drain pipe 2 by the opposing electrode pair 16 disposed outside the detection pipe 12 that is the detected portion of the double pipe 4. Based on the change in the capacitance in the detection tube 12 caused by this, a leak can be detected and an alarm can be issued. Further, since the electrode pair 16 is disposed outside the detection tube 12, the construction is also easy. Furthermore, since the electrode pair 16 does not come into contact with the liquid in the detection tube 12, corrosion or the like does not occur. Therefore, it is possible to detect various liquid leaks and issue an alarm regardless of the type of liquid.

  Since the detection tube 12 is fluidly connected to the drain tube 2, the leakage collected in the detection tube 12 through the drain tube 2 can be reliably detected. Moreover, since the leak can be stored by providing the cock 14 which prevents the outflow of the liquid at the other end of the detection tube 12, it is possible to capture a large change in capacitance due to the storage of the liquid. Furthermore, the liquid can be recovered safely even when the liquid leak to be detected is of a type for which leakage to the outside is prohibited from the viewpoint of the Water Pollution Control Law.

  FIG. 5 shows a circuit diagram including the alarm main body 20 of the present embodiment. One electrode of the electrode pair 16 is electrically connected to the AC power supply 22 via the amplifier 24, and the other electrode of the electrode pair 16 is electrically connected to the output device 26 via the amplifier 25. When a signal (current) is sent from the AC power supply 22 via the amplifier 24 to the electrode pair 16 and the capacitance between the electrode pairs changes due to leakage, the electrode pair 16 passes through the amplifier 25 to the output device 26. A signal (current) corresponding to the change in capacitance is sent. The output device 26 includes a noise filter, a comparator, and the like, and performs an output operation when the current input to the comparator exceeds a certain level. The electric elements such as the AC power source 22, the amplifiers 24 and 25, and the output device 26 that constitute the circuit are provided in the alarm device body 20 (refer to FIG. 1 together).

  FIG. 6 is a solid line graph showing the change over time of the current input to the output device 26 when no leakage at normal time occurs, and the input to the output device 26 when leakage at the time of abnormality occurs. The broken line graph which shows the time change of the electric current which shows is shown. As shown in the figure, when leakage occurs, the current increases, so an alarm is issued by detecting this. For example, in this embodiment, when the value of the current input to the output device 26 is equal to or greater than a certain value, the lamp 20a is turned on to generate an alarm and an alarm sound is output from a speaker (not shown). The notification method is not limited to the light emitted from the lamp 20a or the alarm sound from the speaker, but may be another perceptible method.

  As shown in FIG. 7, as a modification of the present embodiment, a plurality (three in the figure, A to C) of electrode pairs 16 for detecting leakage may be installed at predetermined positions on the pipe. One electrode of the electrode pair 16 of A, B, C is electrically connected to the AC power source 22 via the amplifier 24, and the other electrode of the electrode pair 16 is connected to each terminal of the switch 28. The common terminal is electrically connected to the output device 26 via the amplifier 25. In this case, a single alarm device body 20 can detect leakage at a plurality of locations. Specifically, signals (currents) are sent in parallel from the AC power supply 22 via the amplifier 24 to the plurality of electrode pairs 16 (A to C), and the capacitance changes from the electrode pairs 16 (A to C). In response, a signal (current) is sent to the output device 26 via the switch 28 and the amplifier 25. The operation of the switch 28 is controlled by the control device 30 and switches the signals from the electrode pairs 16 (A to C) in order at regular intervals.

  FIG. 8 shows the output signal of the comparator in the output device 26. If there is a leak, a signal is output from the comparator, and if there is no leak, it is not output. The switch 28 switches the output signals from A to C at regular intervals such as t1, t2, t3, t4,. Therefore, it is possible to specify which electrode pair 16 has detected leakage by measuring the time. The figure shows a state in which a signal is output from the B electrode pair 16 at regular intervals, and the time is measured to identify that the signal is output at t2, t5,. Thus, the signal from the B electrode pair 16 can be specified. The information indicating the location of the liquid leakage thus specified may be an alarm by changing the color of the lamp 20a to be output or the sound emitted from the speaker, or the location of the liquid leakage directly to the user by installing a separate monitor. May be indicated. Since the pipes 2, 4, and 12 used are transparent, the location of leakage can be identified visually even if only the presence of leakage is shown to the user.

(Second Embodiment)
FIG. 9 is a cross-sectional view of the drain pipe 2 of the non-contact alarm device 1 according to the second embodiment. The drain pipe 2 of the present embodiment has the same configuration as that of the first embodiment shown in FIGS. 1 to 3 except that the left and right openings 2a and 2b connected to the double pipe 4 (see FIG. 1) are inclined upward. This is substantially the same as the embodiment. Therefore, description of the same parts as those shown in FIGS. 1 to 3 is omitted.

  In the drain pipe 2 of the second embodiment, the openings 2a and 2b connected to the double pipe 4 are inclined upward. That is, the drain pipe 2 is formed in a Y-shaped inclination so that the liquid leaked from the inner pipe 4a is collected by the gravity at the detection pipe 12 (see FIG. 1) as indicated by the arrow in the figure. Therefore, the detection tube 12 can reliably detect and notify the leakage.

(Third embodiment)
FIG. 10 is a perspective view of the detection tube 12 of the non-contact alarm device 1 according to the third embodiment. The detection tube 12 of this embodiment is directly fluidly connected to the double tube 4 without going through the drain tube 2. Except for this, the configuration is substantially the same as that of the first embodiment shown in FIGS. Therefore, description of the same parts as those shown in FIGS. 1 to 3 is omitted.

  In the third embodiment, a lead-out portion 4 c that is a hole for leading out a leak is provided in the outer pipe 4 b of the double pipe 4. On the other hand, the detection tube 12 is provided with an introduction portion 12a at the upper end. The introduction part 12a has a small mouth part 12b into which a liquid flows and a flange part 12c that extends in a curved shape around the small mouth part 12b. The fore edge portion 12b protrudes upward from the flange portion 12c, and the curved surface of the flange portion 12c is formed along the outer peripheral surface of the outer tube 4b. Therefore, the detection tube 12 and the outer tube 4b are connected by the small end portion 12b of the detection tube 12 being inserted into the lead-out portion 4c of the outer tube 4b and the flange portion 12c being in contact with the outer peripheral surface of the outer tube 4b.

  As described above, since the detection tube 12 is directly fluidly connected to the outer tube 4b, the leakage in the double tube 4 can be detected and an alarm can be issued without requiring a member such as a joint.

(Fourth embodiment)
FIG. 11 is a perspective view of the electrode pair 16 of the non-contact alarm device 1 according to the fourth embodiment. The electrode pair 16 of the present embodiment is attached to the sheet member 32. Except for this, the configuration is substantially the same as that of the first embodiment shown in FIGS. Therefore, description of the same parts as those shown in FIGS. 1 to 3 is omitted.

  The electrode pair 16 of the fourth embodiment is attached to the sheet member 32. Thus, by sticking the electrode pair 16 to the sheet member 32, the construction of the electrode pair 16 on the double tube 4 becomes easy. The electrode pair 16 is disposed so as to oppose the lowermost part of the double tube 4. Since the electrode pair 16 can be arranged in a certain manner, it is possible to prevent displacement of the electrode pair 16 during construction.

  In the present embodiment, the electrode pair 16 is disposed directly on the outer peripheral surface of the outer tube 4 b of the double tube 4. Therefore, in this embodiment, the outer tube 4b of the double tube 4 and the detection tube 12 in the present invention are configured as the same part. As described above, since the outer tube 4b is used as the detection tube 12 and the electrode pair 16 is disposed directly on the outer peripheral surface of the outer tube 4b, the leakage can be detected and notified with a simple configuration without newly providing the detection tube 12. In the present embodiment, the detected portion of the present invention is a part of the outer tube 4 b of the double tube 4.

  Through the above embodiments, the target liquid for detecting leakage is not particularly limited, and may be various liquids such as a chemical solution and various treatment waste liquids. Moreover, the shape and material of the double tube 4 and the detection tube 12 are not particularly limited. Specifically, the material may be any material that does not affect the capacitance to be measured, and may be substantially non-metallic.

DESCRIPTION OF SYMBOLS 1 Non-contact alarm device 2 Drain pipe 2a, 2b, 2c Opening part 2d Inner pipe 2e Outer pipe 2f, 2g, 2h, 2i, 2j Contact surface 4 Double pipe 4a Inner pipe 4b Outer pipe (detected part)
4c Deriving part 12 Detector tube (detected part)
12a Introduction part 12b Small mouth part 12c Flange part 14 Cock 14a Handle 16 Electrode pair 17a Insulating tape 17b Shield electrode 17c Protective tape 18 Cable 20 Alarm body (alarm part)
20a lamp 22 AC power supply 24, 25 amplifier 26 output device 28 switch 30 control device 32 sheet member

Claims (5)

An electrode pair disposed so as to at least partially face the outer peripheral surface of the detected portion provided on the outside of the outer tube of a double tube comprising an inner tube and an outer tube;
An alarm unit that is electrically connected to the electrode pair, and that detects a liquid leak from the inner tube based on a change in capacitance between the electrode pair and issues an alarm;
The detected portion is a non-metallic detection tube communicating with a T-shaped drain tube that fluidly connects the double tubes.
The detection tube is provided with a cock for preventing outflow of liquid from the detection tube,
The electrode pair is a non-contact alarm device disposed immediately above the cock.   2. The non-contact alarm device according to claim 1, wherein the drain pipe is formed to be inclined in a Y shape so that liquid leaked from the inner pipe gathers in the detection pipe. An electrode pair disposed so as to at least partially face the outer peripheral surface of the detected portion provided on the outside of the outer tube of a double tube comprising an inner tube and an outer tube;
An alarm unit that is electrically connected to the electrode pair, and that detects a liquid leak from the inner tube based on a change in capacitance between the electrode pair and issues an alarm;
The detected part is a non-metallic detection pipe fluidly connected to the outer pipe of the double pipe,
The detection tube is provided at one end with an introduction portion fluidly connected to the outer tube, and at the other end is provided with a cock for preventing outflow of liquid from the detection tube,
The electrode pair is a non-contact alarm device disposed immediately above the cock. An electrode pair disposed so as to at least partially face the outer peripheral surface of the detected portion provided on the outside of the outer tube of a double tube comprising an inner tube and an outer tube;
An alarm unit that is electrically connected to the electrode pair, and that detects a liquid leak from the inner tube based on a change in capacitance between the electrode pair and issues an alarm;
The detected part is made of non-metal, and is a part of the outer pipe of the double pipe,
The said electrode pair is a non-contact alarm device arrange | positioned so that it may oppose on both sides of the lowest part of the said double tube.   The non-contact alarm device according to claim 1, wherein the electrode pair is attached to a sheet member.

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