JP2009186238A - Method for determining leakage point in air pipe arrangement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for determining a leakage point of an air pipe 10 in an air piping network 1, which has no risk of causing equipment to malfunction and produces no offensive odor. <P>SOLUTION: The method which determines the leakage point of the air pipe 10 in the air piping network 1 being filled up with compressed air, includes: a step of injecting a leakage detection-use gas other than air (e.g., inert gas) into the air pipe 10; and a step of specifying an area including the leakage point by detecting the leakage detection-use gas leaking from the leakage point of the air pipe 10. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for determining an air leakage portion of an air pipe for supplying high-pressure air to each facility in a factory or the like.

  In industrial facilities and the like, compressed air is used for operation of equipment, but air leakage may occur due to deterioration over time of valves and joints of air piping. The occurrence of air leakage is revealed by a decrease in the pressure in the air pipe, an increase in the operating time of the air compressor that sends compressed air to the air pipe, and the like. Conventionally, as a method for identifying a leak location, soap water is applied to a valve or a joint portion of an air pipe, and the presence or absence of bubbles generated by the leak and soap water has been confirmed.

  However, in a large-scale industrial facility or the like, the total length of the air pipe is very long, and it takes much time to apply soapy water over the entire air pipe. In addition, air pipes are often housed in a pipe groove with a lid, and in that case, it is very hard to open the lids one by one and apply soapy water to check for bubbles. Furthermore, there is a risk that a portion that is difficult to visually recognize may be overlooked because the presence or absence of bubbles cannot be sufficiently confirmed.

On the other hand, Patent Document 1 discloses a technique for injecting a gas having odor into a pipe and determining a leak location in the pipe by sensing the odor. However, when a gas having an odor is used in an air pipe of an industrial facility or the like, the odor component may adversely affect the device, and the odor gas may deteriorate the surrounding environment.
JP 2004-53567 A

  An object of this invention is to provide the method of determining the leak location of an air piping, without having a bad influence on an apparatus with respect to such a subject.

1st invention is a method of judging the leak location of air piping,
Injecting a predetermined gas other than air into the air pipe;
Identifying the area to which the leak location belongs by detecting the predetermined gas leaking from the leak location of the air pipe;
The air leak location determination method of the air piping characterized by including.

  2nd invention uses the inert gas as said predetermined | prescribed gas, The leak location determination method of the air piping of Claim 1 characterized by the above-mentioned.

  According to a third aspect of the present invention, the time at which the predetermined gas arrives at each location is estimated based on the time when the predetermined gas is injected and the moving speed of the air in the air pipe. 3. A method for determining a leak location in an air pipe according to claim 1, wherein the predetermined gas is detected at a predetermined time.

  ADVANTAGE OF THE INVENTION According to this invention, there is no danger of a malfunction of an apparatus and the method of determining the leak location of an air piping can be provided, without generating an odor.

  FIG. 1 is an example of an application target of the method for determining an air leakage location according to the present invention. As shown in the figure, the air piping network 1 includes an air piping 10, an air compressor 20, an air tank 30, a pressure reducing valve 40, and the like.

  The air pipe 10 supplies compressed air of several atmospheres to several tens of atmospheres to the devices 61 to 64, and the devices 61 to 64 operate using the compressed air supplied from the air piping network 1. . The air compressor 20 takes in air from the atmosphere and injects compressed air into the air tank 30. The air tank 30 stores the compressed air injected from the air compressor 20. The air compressor 20 is set to operate when the pressure of the air tank 30 drops below a predetermined pressure, whereby the pressure of the air stored in the air tank 30 is maintained above the predetermined pressure. The pressure reducing valve 40 lowers the compressed air stored in the air tank 30 to an appropriate pressure and supplies the compressed air to each device 61 to 64 via the air pipe 10. Each of the devices 61 to 64 performs an air ring (an operation for constantly releasing a part of the supplied compressed air).

  A gas injection pipe 31 is connected to a portion of the air pipe 10 between the air tank 30 and the pressure reducing valve 40. The gas injection pipe 31 is provided with a gas injection valve 32.

  Hereinafter, a method for determining the location of air leakage when air leakage occurs in the air piping 10 of the air piping network 1 will be described.

  First, a predetermined gas other than air (hereinafter referred to as “leak detection gas”) is injected into the air tank 30. The gas for detecting leakage is a gas that does not cause malfunction of the device, etc., and is a harmless gas that can be detected even at a low concentration. For example, an inert gas such as carbon dioxide It is. The gas leakage detection gas is injected into the air tank 30 in the following procedure. First, a gas tank that stores gas for detecting leakage is connected to the gas injection pipe 31 with the gas injection valve 32 closed. Next, after slightly releasing the compressed air in the air tank 30, the gas injection valve 32 is opened. Thereby, the gas for leak detection is injected into the air tank from the gas tank through the gas injection pipe 31. In addition, discharge | release of the compressed air from the air tank 30 shall be performed in the range in which the pressure in the air tank 30 does not fall below the said predetermined pressure (the air compressor 20 does not operate | move).

  In addition, as shown in FIG. 2, a spare tank 35 and valves 36 and 37 may be provided to store compressed air in the spare tank 35. Thus, by opening the valve 37 with the valve 36 closed, the air tank 30 is filled with the gas for detecting leakage while maintaining the pressure of the air pipe 10 with the compressed air stored in the spare tank 35. be able to.

  Next, air mixed with a gas for detecting leakage is sent from the air tank 30 to the air pipe 10. The compressed air in the air pipe 10 is gradually released from the devices 61 to 64 arranged at the end of the air pipe network 1, and the air leakage detection gas moves in the air pipe 10 accordingly. The moving speed of the predetermined gas can be calculated from the thickness of the air pipe 10, the air pressure in the air pipe 10, and the amount of air released by the air rings in the devices 61 to 64. For example, when the inner diameter of the air pipe 10 is 19 mm, the pressure in the air pipe 10 is 15 atm, and the discharge amount by the air ring of the device 61 is 200 ml / min, the air ring location is 5 cm / min. In the case where two devices 61 and 62 are installed at the tip of the air pipe, the amount of air released by the air ring is 400 ml / min, so the moving speed is 10 cm / min.

  Now, the person in charge of determining the leak location searches for the predetermined gas leaking from the air pipe 10 with the gas detector 70 capable of detecting the leak detection gas. The search for the predetermined gas is basically performed from the upstream side to the downstream side of the air pipe 10. At this time, as described above, the time at which the predetermined gas arrives is calculated based on the moving speed of the predetermined gas. It is good to do.

  When the person in charge of air leakage location determination detects a predetermined gas leaking from the air pipe 10 with the gas detector 70, the air pipe in the area near the detected point (for example, within a radius of 1 to 2 m from the detection point) It can be determined that there is an air leak location at 10.

  If the area to which the leak location belongs can be specified by the leak location determination method, soap water or the like is applied to the air pipe 10 in the area, and the location where bubbles are generated by the soap water or the like is searched. If bubbles are found, this is where the air leaks.

  As described above, the area to which the air leak location of the air pipe 10 belongs can be specified by the air leak location determination method. Conventionally, the air pipe 10 of the air pipe network 1 had to be inspected, for example, by applying soapy water until an air leak location was found. However, according to the air leak location determination method, the area where the air leak location of the air pipe 10 exists can be narrowed down, so that the work efficiency of the air leak location determination can be increased.

  The air pipe 10 is often protected by being stored in a pipe groove with a lid. With the conventional method for determining the location of air leaks with soapy water, it has been difficult to open the lid and bend over and reach into the piping groove. In addition, depending on the location, there are also locations where it is difficult to visually recognize the generation of bubbles even when soapy water is applied, and there is a problem that accuracy may be lacking. However, according to this air leak location determination method, it is not necessary to open the lid one by one, it is not necessary to bend, and even a location that is difficult to visually recognize can be determined.

  Furthermore, if an inert gas is used as the predetermined gas, the device will not malfunction due to the reaction of the odor component, and it is harmless and odorless, so the surrounding environment is not deteriorated.

  In addition, the description of the above embodiment is for facilitating understanding of the present invention, and does not limit the present invention. It goes without saying that the present invention can be changed and improved without departing from the gist thereof, and that the present invention includes equivalents thereof.

It is a whole lineblock diagram of air piping network 1 which is an example of a to-be-inspected object which judges a leak location using a leak location judging method of the present invention. It is a whole block diagram of the air piping network 2 which is another example of the to-be-inspected object which determines a leak location using the leak location determination method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air piping network 10 Air piping 20 Air compressor 30 Air tank 32 Gas inlet 40 Pressure reducing valve 70 Gas detector

Claims (3)

A method for determining a leak location of an air pipe,
Injecting a predetermined gas other than air into the air pipe;
Identifying the area to which the leak location belongs by detecting the predetermined gas leaking from the leak location of the air pipe;
A method for determining an air leakage portion of an air pipe, comprising:   The method for determining a leak location in an air pipe according to claim 1, wherein an inert gas is used as the predetermined gas.   Based on the time when the predetermined gas is injected and the moving speed of the air in the air pipe, the time at which the predetermined gas reaches each location is estimated, and the predetermined time is estimated at the estimated time. The method for determining an air leak location in an air pipe according to claim 1 or 2, wherein gas is detected.

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