JPH08333794A - Leakage place searching method for vacuum sewer pipeline and structure thereof - Google Patents

Abstract

PURPOSE: To search a leakage place easily in a short time. CONSTITUTION: A vacuum sewer pipe 1 is divided into a plurarity of blocks by block valves, and inspection parts are provided in at least two places in each block. A pipeline is blocked in order from the block valve 2 in an upper reaches position most away from a vacuum source so as to detect leakage in the block, adjacent to the upper reaches side, in the lowest reaches position out of the closed block valves 2 when vacuum pressure changes. The block valve 2 on the upper reaches of the leakage block where a leakage place is detected is placed in the blocking state, and all the block valves on the lower reaches side of this block valve are opened. The inspection parts in two places to which sound in the leakage block is transmitted are thereby selected to detect the leakage sound from the leakage place. The leakage place is therefore specified from the arrival time difference of the leakage sound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for searching a leak location of a vacuum sewer pipe and its structure, and more particularly to a method for searching a leak location of a vacuum sewer pipe buried underground and its structure.

[0002]

2. Description of the Related Art In a vacuum sewer pipe buried in the ground, when repairing a leak location, it is preferable to identify the location in consideration of workability and cost, and to perform excavation work. Various methods and structures have been proposed in the past so as to search for.

For example, Japanese Laid-Open Patent Publication No. 7-3864 discloses the following leak location search method. That is, in this leakage location search method, first, the vacuum sewer pipe can be divided into a plurality of sections by a section valve, and the section valve at the upstream position farthest from the vacuum source is sequentially closed to reduce the vacuum pressure. From the change, identify the section where the leak location is located. Next, the specified section is partitioned by a section valve, a vacuum pump is connected to the inspection pipeline on one end side, and a plug is inserted from the inspection pipeline on the other end side. The plug moves forward and backward in the vacuum pipe line and elastically expands and contracts in the radial direction.By advancing this plug into the vacuum pipe line, changes in vacuum pressure in a specified section are detected and leaked. Identify the location.

[0004]

However, in the conventional method for searching the leakage location of the vacuum sewer pipe, the above-mentioned method is used in order to identify the leakage section and to identify the position of the leakage. Uses a structural plug. Since this plug has a structure to be inflated by air pressure or the like, it may be damaged and is inconvenient to handle. Further, if the leakage location is located away from the inspection tube into which the plug is inserted, the plug must be allowed to enter that location, and it takes time to identify the leakage location. In this case, it goes without saying that it takes time to clean up. Furthermore, in order to insert the plug into the vacuum sewer pipe, it is necessary to completely remove the dirty water in the pipe, which causes a long working time. Furthermore, the inspection pipe must not only allow the plug to be inserted, but also must be taken out surely, and it is impossible to have a simple structure. Therefore, the vacuum sewer pipe is arranged at a position close to the surface of the earth. It is not possible.

In view of the above problems, it is an object of the present invention to provide a method for searching for a leak location of a vacuum sewer pipe and a structure thereof, which enables a leak location to be searched easily in a short time.

[0006]

In order to achieve the above object, in the present invention, a vacuum sewer pipe is divided into a plurality of sections by section valves, and inspection sections are provided at least at two positions in each section, and When the vacuum pressure changed, the leak was detected in the section adjacent to the upstream side of the most downstream position of the closed section valve by closing the pipeline in order from the section valve at the farthest upstream position. After that, the upstream section valve of the leakage section in which the leakage point is detected is closed, and all the section valves on the downstream side of the section valve are opened, so that the leakage sound in the leakage section is transmitted. By selecting the inspection unit and detecting the leak sound from the leak place, the leak place is specified from the difference in the arrival time of the leak sound.

As a concrete structure, the vacuum sewer pipe is divided into a plurality of sections by a section valve, and at least two sections are provided in each section.
An inspection member for locating the inspection unit is provided near the surface of the ground.

The inspection member may be made of a material different from the vacuum sewer pipe and having a small sound wave loss coefficient.

In the vacuum sewer pipe, a downward sloping portion that gradually inclines vertically downward and an upward sloping portion that vertically inclines upward are alternately arranged as it goes toward the downstream side where the vacuum source is located. It is preferable that the liquid has a lift structure in which the inspection members are disposed near the upper and lower stream sides of the lower bent portion.

It is preferable to connect a vacuum transfer pipe for transferring vacuum by bypassing the portion of the lower bent portion where the liquid stays, and to provide a sluice valve to the vacuum transfer pipe.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) The vacuum sewer pipe shown in FIG. 1 has a structure in which the vacuum sewer pipe 1 is divided into a plurality of sections by a section valve 2 provided at predetermined intervals. Four inspection tubes 3 are connected (in FIG. 1, one of the inspection tubes 3 in the section is omitted). The upstream side of the vacuum sewage pipe 1 is branched at a plurality of locations and connected to a sewage generation source (not shown) of each household or the like, while the downstream side is connected to a vacuum source 4.

The vacuum sewer pipe 1, as shown in FIG.
A lift structure is formed by connecting a downward sloping portion 1a, which gradually inclines vertically downward toward the downstream side, and an upward sloping portion 1b, which inclines vertically upward, alternately.
Then, the sewage from the sewage generation source stays at each of the lower bent portions 1c of the vacuum sewage pipe 1, and is sequentially flown down to the vacuum source 4 side. The vacuum sewer pipe 1 can be made of flexible vinyl chloride or polyethylene in addition to stainless steel. However, in consideration of damage to the pipeline due to ground subsidence or the like, it is preferable to use a highly flexible material such as polyethylene from the viewpoint of reliability.

The section valve 2 is used for specifying a leak section of the vacuum sewer pipe 1 and for preventing sewage from flowing at the time of repairing the leak point. It is preferable to provide them at intervals of 400 m.

The inspection pipe 3 is connected to the vacuum sewer pipe 1 by a saddle type branch saddle 9 shown in FIGS. 4 (a) and 4 (b). As will be described later, the connection interval is dimensioned so that the leak sound of the vacuum sewer pipe 1 can be transmitted to at least two locations. The saddle type branch saddle 9 is a pair of upper and lower mounting members 10 and 11 which are mounted on the vacuum sewer pipe 1 with bolts and nuts.
The upper mounting member 10 has a mounting hole 10a communicating with the opening formed in the vacuum sewer pipe 1, and the inspection pipe 3 is connected thereto. Also,
The inspection pipe 3 has an inspection portion 5 positioned on the upper portion near the surface of the earth. As shown in FIG. 3, the inspection unit 5 has a structure in which the upper opening 3a of the inspection pipe 3 is closed by a flange 7 formed by screwing a cap 6 into the central portion, and a leakage sound detector 8 described below is used. It is used to detect the leak sound of the vacuum sewer pipe 1.

The leak sound detector 8 is a detector body 8a.
And a transmitter 8c for transmitting the leak sound detected by the sensor 8b to the detector main body 8a. When detecting the gas propagation sound transmitted through the gas in the vacuum sewer pipe 1, the cap 6 is removed from the flange 7 and the sensor 8b is screwed into the cap 6. Further, when detecting the solid-borne sound transmitted through the vacuum sewer pipe 1, the sensor 8b is brought into direct contact with the flange 7 and the cap 6. And each transmitter 8
The leak location is searched from the detection time difference (phase difference) of the leak sound transmitted from c to the detector body 8a. The leak noise detector 8 that can be used is, for example, a leak noise collector LC3000 manufactured by Fujitecom.

In the vacuum sewer pipe having the above construction, there is a risk that cracks may occur in the vacuum sewer pipe 1 due to deterioration with time during installation or after that, or a connection failure or the like may occur in the connection part between the vacuum sewer pipes 1. There is. In this case, gas may flow into the pipe and a desired vacuum pressure may not be obtained, or sewage may leak. Therefore, in the present embodiment, the presence / absence of leakage is determined and the location of leakage is searched for as follows.

The presence or absence of leakage is judged from the change in the operating time of the vacuum source 4. That is, the vacuum source 4 evacuates the vacuum sewer pipe 1 at regular intervals, but if there is a leak location in the vacuum sewer pipe 1, the vacuum source 4 cannot be smoothly evacuated, and the vacuum source 4 is frequently evacuated. The pull will be repeated.
Therefore, if the vacuum source 4 is evacuated more frequently and the operation time interval is shortened, it is determined that leakage has occurred. If it is determined that the leak has occurred, then the leak location is searched for. In the search for the leak location, first, the most upstream section valve 2 in the region where the leak location is to be searched is closed, and all the downstream section valves 2 are opened. Then, the section valve 2 on the upstream side is sequentially closed, and the leakage section is specified by the change in the vacuum pressure in the same manner as in the conventional case. That is, when the closing section valve 2 is located on the upstream side of the leak location, the vacuum degree in the vacuum sewer pipe 1 continues to decrease, but the section valve located on the downstream side of the leak location. Since the degree of vacuum does not change when 2 is closed, the leak section can be specified.

When the leak section is specified, only the upstream section valve 2 that partitions the leak section is closed, and the section valve 2 on the downstream side is all opened to maintain the vacuum state.
The vacuum pressure at this time is set by the vacuum source 4 to be, for example, −5 mH ₂ O. Then, the leakage sound detector 8 detects the leakage sound at two inspection parts 5 of the inspection pipe 3 provided in the leakage section. In this case, the sewage in the vacuum sewage pipe 1 is left as it is, the leak sound is detected by the solid propagation sound transmitted in the vacuum sewage pipe 1, or the gas propagation sound transmitted in the gas in the vacuum sewage pipe 1 by removing the sewage is detected. You can do it. However, in the case of detecting the gas propagation sound, the atmosphere is introduced into the vacuum sewer pipe 1 by opening the check pipe 3 and the valve of the vacuum valve unit at the closest position on the downstream side of the closed section valve 2, thereby introducing the dirty water. Need to be completely drained. Of course, compared to solid propagating sound, gas propagating sound is less attenuated, so sensitivity and accuracy are higher,
Therefore, since it is possible to search for leaks over a wide range,
There is an advantage that the arrangement interval of the inspection pipe 3 can be widened. If no leak sound is detected from both of the selected two inspection units 5, the other inspection unit 5 is used.

In this way, if the leak sound can be detected by the two inspection units 5, the leak location is specified from the arrival time difference of the leak sound (or the phase difference of the arriving sound waves). For example, in FIG. 1, when the position A is a leakage place, if the arrival times of the leak sound signals transmitted to the detector body 8a are T1 and T2, and the interval between the inspection tubes 3 is L, each inspection tube 3 Location A leaked from
The distances L1 and L2 to L1 = [T2 / (T1 + T2)] × L L2 = [T1 / (T1 + T2)] × L Therefore, the ground in a predetermined range including the identified leak location is excavated to repair the leak location. In this case, since the leak location can be accurately specified, the excavation range can be narrowed, and efficient repair can be performed in a short time.

(Experimental Example 1) In the case of detecting a gas propagation sound as a leakage sound by the inspection pipe 3, a search test of a leakage place was conducted as follows, and an arrangement interval of the inspection pipe 3 was determined. That is, a polyethylene inspection pipe 3 having a diameter of 50 mm is connected to a vacuum sewer pipe 1 made of polyethylene having a diameter of 150 mm using a saddle type branch saddle made of polyethylene by electric welding, and the inspection portion 5 is located at a position 150 mm below the surface of the earth. Set Then, the interval for providing the inspection pipe 3 is 20
Three types of 0 m, 300 m, and 400 m were prepared, and a rectangular hole of 1 mm × 18 mm was bored in the middle portion of each inspection tube 3 as a leakage place. Moreover, the vacuum pressure in the vacuum source 4 is set to -5 mH.
₂ O and the distance to the block valve 2 is about 1000 m
And As a result, the leakage sound could be detected if the inspection tube 3 was arranged at an interval of 200 m, but it could be detected at 300 m or not, and could not be detected at 400 m. Therefore, when the leak sound is detected based on the gas propagation sound, the interval between the inspection pipes 3 is 2
It was judged that it is preferable that the length is 00 m or less.

(Second Embodiment) In the above embodiment, the inspection pipe 3 is used.
It is configured to be integrally connected to the vacuum sewer pipe 1.
In the embodiment, as shown in FIG. 5, a rod-shaped inspection member 12 made of another member is brought into contact with the vacuum sewer pipe 1. In this case, only the solid propagating sound transmitted through the vacuum sewer pipe 1 itself is detected, and the search range is narrower than that of the gas propagating sound. However, the inspection member 12 is placed at a desired position when the vacuum sewer pipe 1 is buried. There is an advantage that it can be easily installed only by bringing them into contact with each other, and that the installation location can be easily changed thereafter. As the inspection member 12, it is preferable to use a material having a small sound wave loss coefficient (for example, stainless steel).
It is possible to widen the arrangement interval.

(Experimental Example 2) In the case of detecting solid propagating sound as leakage sound by the stainless inspection member 12, a leak location search test was conducted as follows, and the arrangement interval of the inspection members 12 was determined. . In this experiment, the experimental example 1 is that vinyl chloride is used in the vacuum sewer pipe 1, the inspection member 12 is used in place of each inspection pipe 3, and three types of intervals of 90 m, 110 m, 140 m are prepared. The only difference is that the other conditions are the same. As a result, the leak sound could be detected when the inspection members 12 were arranged at intervals of 90 m and 110 m, but not at 140 m. Therefore, when the inspection member 12 is provided separately from the vacuum sewer pipe 1 and the leak location is searched for based on the solid-borne sound, the arrangement interval of the inspection members 12 is 100 m.
It was determined that the following was preferable.

(Third Embodiment) In addition to the structure of the first embodiment, the third embodiment is a vacuum transfer pipe so as to bypass the lower bent portion 1c of the vacuum sewer pipe 1 as shown in FIG. 13 are connected. A gate valve 13 is provided in the middle of the vacuum transfer pipe 13.
a is provided. This sluice valve 13a is used by closing it in a state where normal wastewater is flowing down and opening it when searching for a leak location. If the sluice valve 13a is opened, the vacuum pressure can be transmitted to the upstream side without lowering the vacuum pressure regardless of the presence of the liquid stored in the downward bending portion 1c. Therefore, the downward bent portion 1c of the vacuum sewer pipe 1
The leakage sound can be transmitted to the inspection unit 5 as the gas propagation sound without removing the dirty water accumulated in the inspection pipe 3, and the interval at which the inspection pipe 3 is provided can be widened.

(Experimental Example 3) The vacuum transfer tube 13 is provided,
In the case of detecting a gas propagation sound as a leak sound, a search test of a leak place was performed as follows, and an arrangement interval of the inspection pipe 3 was determined. This experiment differs from Experimental Example 1 in that a vacuum transmission pipe 13 is connected to the vacuum sewer pipe 1 so as to bypass the lower bent portion 1c. As a result, the leak sound could be detected when the inspection tubes 3 were arranged at intervals of 200 m and 300 m, but could not be detected at 400 m. Therefore, when the vacuum transmission pipe 13 is provided in the vacuum sewer pipe 1, it was determined that it is preferable that the inspection pipes 3 are arranged at intervals of 300 m or less. It should be noted that in Experimental Examples 1 and 3, the inspection gas 3 is arranged at different intervals while detecting the same gas propagation sound because the actual vacuum sewer pipe 1 is connected with sewage generation sources at a plurality of points. It was judged that it was impossible to avoid the inflow of sewage from any sewage source. That is, in Experimental Example 1, the liquid in the vacuum sewer pipe 1 is not completely removed, and therefore the transmission distance of the gas propagation sound is short.

[0026]

As is apparent from the above description, according to the present invention, the leak location is specified based on the leak sound of the vacuum sewer pipe, so that the leak location can be searched easily and quickly. You can In addition, because it only detects the leak sound, the connection structure between the vacuum sewer pipe and the inspection pipe can be simplified, and the vacuum sewer pipe can be buried near the surface of the earth, Compared to, it is possible to increase the number of inspection points freely.

Further, when the leak sound is detected through the inspection member which is a member different from the vacuum sewer pipe, the connecting portion of the vacuum sewer pipe can be reduced to reduce the risk of leakage.
It is possible to simplify the installation work and increase the degree of freedom of the installation site. In particular, when the inspection member is made of a material having a small sound wave loss coefficient, the detection range of the leak sound can be widened, and the arrangement interval of the inspection members can be widened to reduce the number thereof.

Further, when the vacuum transmission pipe is connected so as to bypass the downward bent portion of the vacuum sewer pipe, the leak sound can be detected based on the air propagation sound without removing the liquid in the vacuum sewer pipe. It becomes possible to widen the detection range. As a result, the interval at which the inspection unit is provided can be widened, and the time for searching for a leak location can be shortened.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a leak location search structure of a vacuum sewer pipe according to a first embodiment.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a cross-sectional view showing an inspection pipe portion of FIG.

FIG. 4 is a sectional view (a) and a plan view (b) of a saddle-type branch saddle.

FIG. 5 is a schematic diagram showing a leak location search structure of a vacuum sewer pipe according to a second embodiment.

FIG. 6 is a schematic diagram showing a leak location search structure of a vacuum sewer pipe according to a third embodiment.

[Explanation of symbols]

 1 Vacuum sewer pipe 2 Section valve 3 Inspection pipe 5 Inspection department

Claims (5)

[Claims] 1. A vacuum sewer pipe is divided into a plurality of sections by section valves, at least two inspection sections are provided in each section, and the pipeline is closed in order from the section valve at the upstream position farthest from the vacuum source. When the vacuum pressure changes by detecting the leakage, after detecting a leak in the section adjacent to the upstream side of the most downstream position of the closed section valve, the section valve on the upstream side of the leakage section where the leakage point is detected Is closed, and all the section valves on the downstream side of the section valve are opened to select two inspection parts through which the leakage sound in the leakage section is transmitted, and the leakage sound from the leakage point is detected. Accordingly, the leak location is identified from the difference in the arrival time of the leak sound, and the leak location search method of the vacuum sewer pipe is characterized. 2. A vacuum sewer pipe, characterized in that the vacuum sewer pipe is divided into a plurality of sections by a section valve, and each section is provided with at least two inspection members for positioning an inspection unit near the surface of the earth. Leakage location search structure. 3. The structure for searching a leak location of a vacuum sewer pipe according to claim 2, wherein the inspection member is made of a material different from the vacuum sewer pipe and having a small sound wave loss coefficient. . 4. The vacuum sewage pipe is provided with a downward sloping portion that gradually inclines vertically downward and an upward sloping portion that vertically inclines upward alternately toward the downstream side where the vacuum source is located. 4. The vacuum structure according to claim 2, wherein the lift structure has a structure in which the liquid is retained at the bent portion, and the inspection members are arranged near the upstream and downstream sides of the lower bent portion. Leakage location search structure for water pipelines. 5. A vacuum transfer pipe for bypassing a portion of the lower bent portion where the liquid stays is bypassed to connect a vacuum transfer pipe, and the vacuum transfer pipe is provided with a gate valve. The structure for searching the leakage location of the vacuum sewer line described in.