JPH076599B2 - Gas pipe communication confirmation device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a device for confirming a connection state of a gas conduit buried in the ground.

[Prior Art and Its Problems] When the gas conduit buried in the ground is congested, it may not be possible to know whether the gas conduit at a certain point is in communication with the gas conduit at another point. is there.

In such a case, an electromagnetic induction method is known as a method for confirming communication between gas conduits. In this method, an alternating current is passed through an electromagnetic coil installed on the ground to induce an electric current in a buried gas conduit to capture the induced current.
As shown in the figure, the exposed part 02 of the gas conduit 01 and the ground or 2
There is a method in which an alternating current 03 is directly applied between exposed parts of the points and a magnetic field 04 generated around the gas conduit 01 is captured from the ground surface by a receiving coil 05, or a method of increasing the applied points to three or more points and measuring . However, in the above-mentioned known method, if a water pipe or a cable is buried adjacent to the gas conduit 01, an electric current may flow through these other objects or an induced current may be generated, so that the gas conduit cannot be identified. Or may lead to misunderstanding. Also, if there is an insulating part in the gas conduit, the confirmation act itself becomes impossible.

Therefore, as shown in FIG. 3, an open riser pipe 06 (often using a test port of a gas meter attachment pipe etc.) is provided in a part of the gas conduit 01, and the open riser pipe 06 is rapidly opened to produce raw gas. Gas is released momentarily and the other purge gas pipe 07
A method has been proposed to check how the pressure fluctuation propagates to the underwater gauge 08.

However, with this confirmation method, in the case of a gas conduit with many branches, it is necessary to release a considerably large amount of gas and the underwater gauge.
The pressure fluctuation does not propagate to the purging gas pipe 07 to which 08 is attached, and even if it propagates, the pressure in the gas conduit is constantly fluctuating, and to distinguish the difference from this normal pressure fluctuation. Come to difficulties. Also, it is not preferable to release raw gas.

[Object of the present invention] The object of the present invention is to propose a communication confirmation device for a gas conduit that does not have such drawbacks.

[Configuration of the Present Invention] In order to achieve the above-mentioned object, the present invention proposes a gas conduit communication confirmation device having the following configuration.

A sound wave transmitter capable of selectively emitting a sound wave composed of low frequency and high frequency; a microphone for transmitting the sound wave generated by the sound wave transmitter in a gas conduit from a transmission port opened in a part of the gas conduit; A sound wave receiver that receives a sound wave that has propagated through the gas conduit from a reception port that is opened in a part of the conduit, and a frequency that is the same as the frequency that is transmitted by the sound wave transmitter from the sound waves that are received by the sound wave receiver. A gas conduit communication confirmation device comprising: a bandpass filter that selects only the frequencies centered around the frequency of the above, and a sound wave receiver that widens the frequencies that have passed through this bandpass filter and that can be heard by earphones.

In the above device, when there are many bends in the gas conduit, a low frequency sound wave (382.5Hz) is selected, transmitted from the microphone into the gas conduit, received by the receiver, and heard through the earphone. Then, for example, an intermittent sound at 1 second intervals is emitted so that the emitted sound can be distinguished from noise in other gas conduits, and this is received and only the frequency component equal to the emitted sound is amplified. Also, if there are few straight pipes or bent portions, or if there is a risk of sound waves propagating through another route, a high frequency (607.5Hz) is used.

[Embodiment] In FIG. 1, 1 is a gas conduit, 2 is a sound wave transmission tube raised to the ground, 3 is a sound wave transmitter capable of selecting low frequency and high frequency sound waves, and 4 is a transmitted sound wave. Is a speaker attached to the entrance of the sound wave transmitter 2.

6 is a sound wave receiving tube which is raised from the gas conduit 1 to the ground, 7 is a microphone attached to the inlet of this sound wave receiving tube 6, and 8 is a sound wave received by the microphone 7, which has the same frequency as the transmitted sound wave. Is a sound wave receiver for filtering and amplifying the sound wave with a bypass filter, and reference numeral 9 is an earphone for listening to the sound wave thus filtered.

Next, the usage of the above device will be described.

First, in the conduit of the gas conduit 1, if there are many bends, select the low frequency (382.5Hz) in consideration of its transmissibility,
This is transmitted from the speaker 5 into the gas conduit 1 via the sound wave transmission tube 2. The transmitted sound wave propagates in the gas conduit 1, and this sound wave is received by the microphone 7 from the sound wave receiving tube 6, and the received sound wave is the same as the transmission frequency by the bypass filter in the sound wave receiver 8. It is filtered and widened. Then, the amplified sound wave is heard by the earphone 9. In order to prevent misidentification with other noises and to facilitate confirmation of sound waves, work is performed with intermittent sounds at 1 second intervals.

Next, if the gas conduit 1 is a straight pipe or there are few curved pipes, or if a sound wave is easily transmitted by bypassing another pipe, a high frequency (607.5Hz) is taken into consideration in consideration of straightness. To use.

[Effect of the present invention] As described above, the present invention transmits low-frequency and high-frequency sound waves into the gas conduit while selecting them according to the condition of the conduit, and receives the sound waves at other positions. Since the contact status of is confirmed, the following effects can be expected.

a. The transmitted sound wave propagates only through the gas conduit, so there is no effect even if there is an adjacent pipe.

b. Can work while flowing gas.

c. Low frequency and high frequency sound waves are used depending on the condition of the pipeline, so it may be difficult to check depending on the pipeline condition.
There is no risk of misidentification.

d. By using the bypass filter, only the sound wave of the frequency equal to the frequency of the transmitted sound wave is amplified and heard, so it is not affected by noise.

e. It can also be applied to gas pipes or resin pipes that have electrically insulating parts.

f. It is safe to work because it does not emit raw gas.

[Brief description of drawings]

FIG. 1 is an embodiment diagram of the present invention, FIG. 2 is an explanatory diagram of an electromagnetic induction system, and FIG. 3 is an explanatory diagram of a gas pressure detection system. 1 ... Gas conduit 2 ... Sound wave transmission tube 3 ... Sound wave transmitter 4 ... Amplifier 5 ... Speaker 6 ... Sound wave reception tube 7 ... Microphone 8 ... Sound wave receiver 9 ... Earphone

Claims (1)

[Claims] 1. A sound wave transmitter capable of selectively transmitting a sound wave having a low frequency and a high frequency wave, and a sound wave generated from the sound wave transmitter into a gas conduit from a transmission port opened in a part of the gas conduit. A microphone for transmitting, a sound wave receiver for receiving sound waves propagating through the gas conduit from a receiving opening opened in a part of the gas conduit, and a sound wave transmitter for selecting sound waves from the sound waves received by the sound wave receiver. A gas consisting of a bandpass filter that selects only frequencies centered on the same frequency as the transmitted frequency and a sound wave receiver that widens the frequencies that have passed through this bandpass filter and that can be heard by earphones. Conduit contact confirmation device.