JP3527314B2 - Vacuum sewer water pipe bridge - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum sewer water pipe bridge.

[0002]

2. Description of the Related Art Conventionally, natural drainage sewers have been used for collecting sewage, but recently, in some areas, from the viewpoint of cost, etc., vacuum sewers in which a sewer pipe is evacuated (depressurized state) has attracted attention. Is becoming more common.

In the vacuum sewer system, when there is an obstacle A such as a river between the source of sewage and the source of vacuum, for example, as shown in FIG. Is possible. That is, FIG.
Vacuum upstream sewer pipe 21 and downstream vacuum sewer pipe 2 of obstacle A
2 is connected with a siphon pipe 23 and a ventilation pipe 24, and an air pipe 26 having an open valve 25 communicating with the outside air is connected to the upstream vacuum sewer pipe 21.
An opening / closing valve 27 is provided in the above (Japanese Patent Laid-Open No. 4-2584).
24).

In this vacuum sewer system, when the siphon pipe 23 is started up, the on-off valve 27 is closed to fill the inside of the siphon pipe 23 with dirty water, and then the on-off valve 27 is opened. This allows
The vacuum pressure of the downstream vacuum sewer pipe 22 is transmitted to the upstream vacuum sewer pipe 21 via the ventilation pipe 24, and the head loss in the siphon pipe 23 can be almost eliminated. When sewage flows from the upstream vacuum sewer pipe 21, it is made to flow down to the downstream vacuum sewer pipe 22 via the siphon pipe 23 according to the siphon principle. Also, if dirt accumulates in the siphon pipe 23,
By closing the on-off valve 27 and opening the open valve 25, outside air is taken into the siphon pipe 23 via the air pipe 26, and sewage is made to be in a turbulent state to increase kinetic energy, thereby causing filth to flow down.

However, since the siphon pipe 23 is arranged in the ground, there is a problem that the construction is troublesome and costly. For this reason, for example, the water pipe bridge is arranged in the space above the obstacle A such as a river.
Alternatively, the one shown in FIG. 5 has been developed.

That is, FIG. 4 shows the upstream vacuum sewer pipe 21.
And the downstream side vacuum sewer pipe 22 are connected by a siphon pipe 23 via an inflow tank 28 and an outflow tank 29.
The upper space of 8, 29 is shown to be communicated with a ventilation pipe 24, and the siphon pipe 23 and the ventilation pipe 24 are communicated with each other by a connecting pipe 31 having a gas vent valve 30 (Japanese Patent Laid-Open No. 5- No. 202556). 5 shows the upstream vacuum sewer pipe 21 and the downstream vacuum sewer pipe 22 that are connected to each other by a siphon pipe 23 and a ventilation pipe 24. An air reservoir part is provided in the middle of the siphon pipe 23. 31 is formed, and a vacuum pump 32 and a level meter 33 are provided therein (see Japanese Patent Laid-Open No. 6-229001).

In any of the vacuum sewers, as in the above case, the sewage flowing from the upstream side vacuum sewer pipe 21 is caused to flow down to the downstream side vacuum sewer pipe 22 via the siphon pipe 23 according to the siphon principle, and the ventilation pipe 24 is used. The vacuum pressure of the downstream vacuum sewer pipe 22 can be transmitted to the upstream vacuum sewer pipe 21.

[0008] Further, the siphon pipe 2 is caused by the fact that the sewage flows in a state in which it contains air bubbles, or the filth accumulates due to long-term use and gas is generated therefrom.
If the gas stays in 3, the siphon may be destroyed in some cases. Therefore, in the case shown in FIG. 4, the stayed gas is discharged by opening the gas vent valve 30, and the accumulated dirt is collected in the vacuum car. And so on. On the other hand, in the one shown in FIG. 5, the generated gas collects in the air reservoir 31, so by detecting the water level with the level meter 33, if the water level drops to a certain position, the vacuum pump 32 is automatically driven. I try to discharge it.

[0009]

However, in the structure shown in FIG. 4, since the tanks 28 and 29 are maintained in a vacuum, if dirt is deposited on the bottom of the tank, it should be discharged by a vacuum car or the like. It's not easy. Although the gas vent valve 30 is used to remove the gas in the siphon tube 23, the gas cannot be removed even if the gas vent valve 30 is opened. That is, the pressure acting on the siphon pipe 23 side and the vent pipe 24 side across the gas vent valve 30 is different, and since the siphon pipe 23 side is smaller by the weight of the sewage in the substantially vertical portion, it is the reverse rather than the gas being removed. In addition, the dirty water in the siphon pipe 23 flows down to the tanks 28, 29 side.

The vacuum pump 32 shown in FIG.
It is needless to say that not only equipment for supplying electric power for driving the above is required, but also the siphon tube 23 is not only required to have a special shape having the air reservoir portion 31 but also a level meter 33 needs to be provided, resulting in an increase in cost. To do. Moreover, although dirt is difficult to be deposited, it cannot be easily removed when it is deposited.

Therefore, in view of the above problems, the present invention provides a vacuum sewer water pipe bridge capable of effectively removing gas in the siphon pipe and dirt in the tank and promptly recovering the destruction of the siphon. The purpose is to

[0012]

In order to achieve the above-mentioned object, in the present invention, an upstream vacuum sewer pipe and a downstream vacuum sewer pipe, which are arranged with an obstacle in between, are provided via an inflow tank and an outflow tank. And a ventilation pipe having a vacuum opening / closing valve for transmitting the vacuum pressure of the downstream vacuum sewer pipe to the upstream vacuum sewer pipe, the siphon pipe being arranged so as to communicate with the obstacle above the obstacle. In the vacuum sewer water pipe bridge, the siphon pipe and the downstream vacuum sewer pipe are connected by an intake pipe having an intake opening / closing valve, and the connecting portion between the ventilation pipe and the downstream vacuum sewer pipe, and the intake pipe. A downstream side flow passage opening / closing valve is provided between the downstream side vacuum sewer pipe and the connecting portion.

The upstream vacuum sewage pipe is connected to the outside air, and an air pipe having an air introducing on-off valve is connected to the upstream vacuum sewer pipe, while an upstream flow passage on-off valve is provided on the upstream side of the connecting portion of both pipes. Preferably.

Of the two tanks, at least the bottom shape of the inflow tank is a mortar shape whose cross-sectional area gradually decreases downward, and an opening end of a pipe communicating with the mortar-shaped portion of the tank on the downstream side. More preferably, it is positioned.

[0015]

In the invention of the above-mentioned structure, by opening the downstream flow passage opening / closing valve and the vacuum opening / closing valve with the intake opening / closing valve closed, the sewage flows down according to the siphon principle. The vacuum pressure of the downstream vacuum sewer pipe is also transmitted to the upstream vacuum sewer pipe through the ventilation pipe. When the gas stays in the siphon pipe, the downstream side passage opening / closing valve and the vacuum opening / closing valve are closed and the intake opening / closing valve is opened. The siphon pipe is directly connected to the downstream vacuum sewer pipe via the intake pipe, and the gas in the siphon pipe is removed to the downstream vacuum sewer pipe side.

In the invention having the structure including the air pipe, when dirt is accumulated, the open / close valve for introducing air is opened and the open / close valve on the upstream side flow passage is closed, so that the outside air is released into the inflow tank in a depressurized state. Introduce and push down the sewage water surface by air pressure. Thus, the filth accumulated on the bottom of the tank is discharged to the downstream side through the siphon pipe by the sewage flowing at a high speed.

In the invention in which the bottom of the tank is shaped like a mortar, the velocity of the wastewater flowing in the tank increases at the portion where the cross-sectional area is narrowed, and the waste is discharged downstream.

[0018]

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

FIG. 1 shows a vacuum sewer water pipe bridge according to the first embodiment, in which an upstream vacuum sewer pipe 1 and a downstream vacuum sewer pipe 2 are buried in the ground with a river A as an obstacle interposed therebetween. The two are connected by a substantially U-shaped siphon pipe 3 which is bridged above the river A. One end of the upstream vacuum sewer pipe 1 is connected to a sewage generation source (not shown), and the other end is integrally provided with an inflow tank 4. One end of a siphon pipe 3 that bends downward is disposed below the inside of the inflow tank 4, and an outflow tank 5 is integrated at the other end of the siphon pipe 3, and a downstream that bends downward below the inside thereof. One end of the side vacuum sewer pipe 2 is arranged. Downstream vacuum sewer pipe 2
A downstream side passage opening / closing valve 6 is provided at one end of the above, and a vacuum source (not shown) is connected to the other end.

The upper part of the inflow tank 4, the outflow tank 5 of the downstream vacuum sewer pipe 2 and the downstream flow passage opening / closing valve 6 are bridged above the river A, and a vacuum opening / closing valve 8 is provided on the way. It is connected by a ventilation pipe 7.

The horizontal portion of the siphon pipe 3 in the vicinity of the upstream bent portion and the downstream flow passage opening / closing valve 6 of the downstream vacuum sewer pipe 2
As in the case of the ventilation pipe 7, the downstream side of the intake pipe 9 is provided above the river A and has an intake opening / closing valve 10 in the middle thereof.
Is communicated with.

In the vacuum sewer water pipe bridge having the above-mentioned structure, the downstream side passage opening / closing valve 6 and the vacuum opening / closing valve 8 are opened, and the intake opening / closing valve 10 is closed, so that the siphon is operated in the same manner as the conventional water pipe bridge. By the principle, sewage can be made to flow down without causing head loss. That is, the sewage flowing through the upstream vacuum sewer pipe 1 in a gas-liquid two-phase flow state is
In the inflow tank 4, the gas and the liquid are once separated, the gas flows through the ventilation pipe 7, the liquid flows through the siphon pipe 3 and the outflow tank 5, respectively, and both are joined by the downstream vacuum sewer pipe 2 to form a vacuum source. Run down. In this case, the vacuum pressure of the downstream side vacuum sewer pipe 2 is increased by the vacuum pressure of the upstream side vacuum sewer pipe 1 via the ventilation pipe 7.
No head loss will occur.

In the water pipe bridge, gas and liquid are separated by the inflow tank 4, so in principle, no gas enters the siphon pipe 3. However, air bubbles in the wastewater flow into the siphon pipe 3 without being separated, and due to long-term use, gas is generated from the waste accumulated on the bottoms of both tanks 4 and 5 (in particular, the inflow tank 4). If the gas flows into the siphon tube 3, gas may accumulate in the siphon tube 3 and, in some cases, the siphon may be destroyed.

Therefore, before the siphon breaks down, the downstream side passage opening / closing valve 6 and the vacuum opening / closing valve 8 are closed, and the intake opening / closing valve 1 is closed.
By opening 0, only the intake pipe 9 is evacuated and the gas in the siphon pipe 3 is discharged to the downstream vacuum sewer pipe 2 side. In this case, if the discharging work is performed for a long time,
Since the dirty water in the siphon pipe 3 flows into the intake pipe 9, the discharge of gas from the siphon pipe 3 is limited to a certain time,
It is preferable to provide a fluid detecting means such as a transparent pipe in the middle of the intake pipe 9. Then, when the removal of the gas in the siphon pipe 3 is completed, the intake opening / closing valve 10 is closed, and the downstream flow passage opening / closing valve 6 and the vacuum opening / closing valve 8 are opened to restore the normal state.

As described above, according to the first embodiment, the inside of the siphon pipe 3 can be inexpensively constructed by simply providing the intake pipe 9 having the intake opening / closing valve 10 without any special equipment. An aqueduct that can discharge gas can be provided.

FIG. 2 shows a water pipe bridge of a vacuum type sewer pipe according to a second embodiment. In the second embodiment, the point that an air pipe 11 is provided, that the bottom shapes of both tanks 4 and 5 and the end shape of the siphon tube 3 are changed, and that the air tube 11 of the upstream side vacuum sewer pipe 1 is provided. This is different from the first embodiment in that an upstream side flow path opening / closing valve 13 is provided near the upstream side of the connecting portion.

That is, the air pipe 11 is provided in the vicinity of the inflow tank 4 of the upstream side vacuum sewer pipe 1, and the air introducing on-off valve 12 is provided.
Is connected so as to communicate with the outside air.

The bottom shapes of both tanks 4 and 5 are mortar-shaped (reverse frustoconical) whose cross-sectional area gradually decreases downward, and the upstream end of siphon tube 3 has a trumpet shape. The caliber is slightly widened. This makes it possible to increase the flow velocity on the bottom side when dirty water flows in both tanks 4 and 5.

In the water pipe bridge according to the second embodiment having the above-mentioned structure, in the normal state, the downstream side flow passage opening / closing valve 6 and the vacuum opening / closing valve 8 are provided.
Also, the upstream side flow path opening / closing valve 13 is opened and the intake opening / closing valve 10 and the air introducing opening / closing valve 12 are closed. in this case,
Since the bottoms of the tanks 4 and 5 are formed in the shape of a mortar, the flow path area of the wastewater is narrowed, so that the flow of the wastewater at that position becomes faster and the wastes contained in the wastewater are less likely to be deposited. .

When the gas inside the siphon pipe 3 is removed, the downstream flow passage opening / closing valve 6 and the vacuum opening / closing valve 8 are closed and the intake opening / closing valve 10 is opened. Thereby, the gas in the siphon tube 3 can be removed in the same manner as in the first embodiment.

By the way, in the second embodiment, when the specific gravity of the waste is large and the waste is deposited on the bottoms of the tanks 4 and 5, it can be removed as follows. That is, by closing the upstream-side flow passage opening / closing valve 13 and opening the air-introducing opening / closing valve 12, the outside air is exposed to the upstream-side vacuum sewer pipe 1.
It is introduced into the inflow tank 4 while being prevented from flowing into the side. Since the inside of the inflow tank 4 is in a decompressed state by being evacuated, the open air 12 for air introduction is opened so that the outside air rapidly flows into the inflow tank 4, and the air pressure thereof pushes down the surface of the dirty water. Can be As a result, the flow velocity of the sewage flowing into the siphon pipe 3 becomes very fast, the bottom shape of the inflow tank 4 is a mortar shape, and the filth is collected in the center (just below the siphon pipe 3). Since the diameter of the end portion of the pipe 3 is widened, the accumulated filth smoothly flows into the siphon pipe 3. On the other hand, in the outflow tank 5, the sewage whose flow velocity has been increased in the inflow tank 4 flows out at high speed through the siphon pipe 3, so that no filth is accumulated on the bottom and the accumulated filth is removed. It flows down to the downstream vacuum sewer pipe 2 side.

The filth accumulated on the bottom of the tank 4 or 5 is removed as described above, but if the gravitational gravity of the filth is still too large and the removal is insufficient, a compressor or the like (not shown) may be attached to the air pipe 11. It suffices to connect them and supply compressed air into the inflow tank 4.

Not only the dirty water in the inflow tank 4,
If the introduced outside air flows into the siphon pipe 3, the siphon will be destroyed. Therefore, when the water level in the inflow tank 4 drops to a certain extent, the air introducing on-off valve 1
Block 2 The on-off valve 12 for introducing air is the inflow tank 4
It may be blocked at the time when the sewage water surface falls to a certain level by detecting the sewage water surface inside, or may be blocked based on the time or the amount of introduced air predicted to be lowered to a certain level.

By the way, in the second embodiment, when the siphon is destroyed, it can be restored as follows. That is, the downstream flow passage opening / closing valve 6 and the upstream flow passage opening / closing valve 13 are closed, the vacuum opening / closing valve 8 and the intake opening / closing valve 10 are opened, and then the air introduction opening / closing valve 12 is slightly opened. By opening the intake opening / closing valve 10, the gas in the siphon pipe 3 is removed via the intake pipe 9, and the dirty water in each tank 4, 5 flows so as to fill the siphon pipe 3. Further, by opening the air introducing on-off valve 12, the outside air introduced through the air pipe 11 forcibly lowers the sewage water surface in each of the tanks 4 and 5, and helps to fill the sewage pipe 3 with sewage. .

As described above, according to the second embodiment, the intake pipe 9, the air pipe 11 and the open / close valves 6, 8, 10, 12, 1 are provided.
It is possible to restore the siphon state in a very short time with a simple configuration in which only 3 is provided.

In the second embodiment, both tanks 4,
Although the bottom shape of 5 has the same mortar shape, only the inflow tank 4 in which dirt is likely to be deposited may be formed in this way.
A spiral groove may be provided on the inner surface of the mortar-shaped portion of the inflow tank 4 to further increase the flow rate of the dirty water flowing from the inflow tank 4 into the siphon pipe 3.
Further, it is needless to say that if all or part of these valves are electrically operated to automatically open and close the valves 6, 8 and 10, the siphon restoration and the cleaning of the tanks 4 and 5 can be easily performed by their program control. Yes.

[0037]

As is apparent from the above description, according to the present invention, when gas is accumulated in the siphon pipe, it can be discharged through the intake pipe. Therefore, an expensive member such as a vacuum pump can be used. It is possible to avoid siphon destruction in advance without providing.

Further, in the invention in which the upstream vacuum sewage pipe is provided with the air pipe communicating with the outside air, the air pressure in the tank can be drastically increased and the dirty water in the tank can be made to rapidly flow into the siphon pipe. Therefore, the dirt accumulated on the bottom of the tank can be effectively removed and allowed to flow down.

Particularly, in the invention in which the bottom shape of the tank is formed so that the cross-sectional area gradually decreases downward, it is possible to more effectively remove the accumulated dirt.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a water pipe bridge of a vacuum sewer pipe according to a first embodiment.

FIG. 2 is a sectional view showing a water pipe bridge of a vacuum sewer pipe according to a second embodiment.

FIG. 3 is a cross-sectional view showing a water pipe bridge of a vacuum sewer pipe according to a conventional example.

FIG. 4 is a sectional view showing a water pipe bridge of a vacuum sewer pipe according to another conventional example.

FIG. 5 is a cross-sectional view showing a water pipe bridge of a vacuum sewer pipe according to still another conventional example.

[Explanation of symbols]

1 Upstream vacuum sewer 2 Downstream vacuum sewer 3 siphon tube 4 inflow tank 5 spill tank 6 Downstream flow path opening / closing valve 7 Ventilation pipe 8 Vacuum on-off valve 9 Intake pipe 10 Intake valve

Claims (3)

(57) [Claims] 1. An upstream-side vacuum sewer pipe and a downstream-side vacuum sewer pipe, which are arranged with an obstacle sandwiched therebetween, communicate with each other through an inflow tank and an outflow tank, and are arranged so as to straddle above the obstacle. In the water pipe bridge of the vacuum sewer equipped with a siphon pipe and a vacuum pipe for transmitting the vacuum pressure of the downstream side vacuum sewer pipe to the upstream side vacuum sewer pipe, and a vent pipe having a vacuum opening / closing valve, the siphon pipe and the downstream side A vacuum sewage pipe is communicated with an intake pipe having an intake on-off valve, and a downstream side is provided between a connection part between the ventilation pipe and the downstream side vacuum sewage pipe and a connection part between the intake pipe and the downstream side vacuum sewage pipe. A water sewer bridge for vacuum sewers, which is equipped with a flow path opening / closing valve. 2. The upstream side vacuum sewer pipe is connected to the outside air and is connected to an air pipe equipped with an air introduction on-off valve, while an upstream side flow path on-off valve is provided on the upstream side of the connecting portion of both pipes. The water pipe bridge for the vacuum sewer according to claim 1, characterized in that. 3. The bottom shape of at least the inflow tank of the two tanks is a mortar shape whose cross-sectional area gradually decreases downward, and the mortar-shaped portion of the tank has an opening of a pipe communicating with the downstream side. The water sewer bridge for a vacuum sewer according to claim 1 or 2, wherein the ends are positioned.