JPH10204967A - Vacuum sewerage system and manhole pump unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce pressure losses at ascending stepped piping, when a multistage lift or a large lift is employed, by providing a sewage holding tank in the middle of a vacuum sewerage system, and force-feeding sewage to a downstream portion using a force feed pump. SOLUTION: A manhole pump unit 10 is provided between the upstream pipeline 11 of a vacuum sewerage pipe 103 and the downstream side pipeline 12 attached to a large bridge spanning over a river, and a force feed pump 14 is intermittently operated by means of upper and lower sewage level detecting switches 17A, 17B provided at a completely airtight sewage holding tank 13, to force-feed the held sewage into the downstream pipeline 12 via a sewage force-feed pump 15. Air flowing in from the upstream pipeline 11 while in an air-gas mixed flow state is separated in the upper space 13A of the tank 13 and fed to the downstream pipeline 12 through a vacuum transmission pipe 16, with the vacuum pressure of the downstream pipe 12 transmitted to the upstream pipeline 11 through the vacuum transmission pipe 16. Therefore, pressure losses are reduced at ascending stepped piping, and the tank 13 is unitized with the force feed pump 14 for ease of system construction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vacuum sewer system and a manhole pump unit.

[0002]

2. Description of the Related Art A vacuum type sewer system is provided with a vacuum station (a vacuum pump and a pressure pump). The vacuum pump applies vacuum pressure toward the end to collect sewage, and the collected sewage is treated by a pressure pump to a treatment plant or the like. (To be sent to a public sewer), a vacuum sewer pipe is connected, and the vacuum pressure applied to the vacuum sewer pipe sucks sewage and air in order at the terminal sewage tank, and the vacuum pressure in front of the sewage and the suction air pressure behind the sewage This system uses the pressure difference between the wastewater and the wastewater as a gas-liquid mixed flow.

[0003] In a vacuum type sewer system, a sewage conveyance mode is different from that of a conventional natural flow type, and a strong pumping force of expansion pumping based on the above-mentioned pressure difference of suction air at the rear of sewage flowing down by gravity according to a natural gradient is obtained. , For conveying sewage at high speed. In addition, in the vacuum type sewer system, a rising step pipe (lift) can be adopted, and the sewage collected at the bottom of the lift is lifted up against the gravity by the force of the passing air, and thereafter, the pumping is performed under gravity flow. Conveyed by force.

[0004] Therefore, in the vacuum type sewer system, the lift is adopted to make the vacuum sewer pipe a shallow buried serrated pipe substantially along the terrain, thereby facilitating civil engineering work. On the other hand, in the vacuum type sewer system, since the vacuum force is used as the transfer force, the system has a limit in the sewage transfer distance due to the limit of the vacuum force and the pressure loss in the step pipe on the ascending lift.

[0005]

The prior art has the following problems. If a multi-stage lift or large lift is used, such as by attaching a vacuum sewer pipe to a large bridge or avoiding it around a huge buried object, the pressure loss of the climbing step pipe will be large,
In some cases, the length of the pipeline of the system becomes short, or the vacuum type design itself becomes impossible.

When a plurality of vacuum stations cannot be installed in terms of equipment cost, a single vacuum station must be provided only in front of a bridge or the like, and the point from the bridge to the treatment plant must be of a natural flow type. In this case, the shallow burial of the vacuum sewer cannot be carried out from the bridge to the treatment plant, and a large power supply for the vacuum pump and the pressure pump and the water sealing water for reaching the vacuum must be provided at a place remote from the treatment plant. It is necessary to prepare.

[0007] Japanese Patent Application Laid-Open No. H5-156693 proposes a system in which a switching valve capable of air blow is provided in order to eliminate accumulation of dirt when a vacuum sewer pipe is moved over, thereby reducing the pressure loss due to the movement. However, large bridges are inefficient in terms of construction costs.

[0008] An object of the present invention is to reduce the pressure loss of an ascending step pipe when a multistage lift or a large lift is employed in a vacuum sewer system.

[0009]

According to a first aspect of the present invention, there is provided a vacuum type sewer system in which a vacuum drain is connected to a vacuum source, wherein a waste water storage tank is provided at an intermediate portion of the vacuum drain. It is provided with a pump for pumping the sewage stored in the storage tank to a downstream portion of the vacuum sewer pipe.

According to a second aspect of the present invention, in the first aspect of the present invention, further, a pump is provided between the sewage storage tank and a downstream portion of the vacuum sewer pipe from the pressure pump to a downstream portion of the vacuum sewer pipe. An extended sewage pressure feed pipe and a vacuum transmission pipe extending from an upper space of the sewage storage tank to a downstream portion of the vacuum sewer pipe are provided side by side.

According to a third aspect of the present invention, in the first or second aspect of the present invention, sewage level detection switches are provided above and below the sewage storage tank, and the upper sewage level detection switch is turned on. The pump is turned on, and the pump is turned off by turning off the wastewater level detection switch.

According to a fourth aspect of the present invention, in addition to the second or third aspect of the present invention, an auxiliary vacuum pump communicating with an upper space of the sewage storage tank is provided.
The vacuum transmission pipe is provided with an on-off valve, and when the internal pressure of the sewage storage tank drops below a certain value, the on-off valve is closed and the auxiliary vacuum pump is turned on. When the internal pressure of the sewage storage tank reaches a certain value, the auxiliary vacuum is turned on. The pump is turned off, and the on-off valve is opened when the internal pressure of the sewage storage tank becomes equal to the pressure downstream of the on-off valve of the vacuum transmission pipe.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the exhaust pipe of the auxiliary vacuum pump is further connected to a downstream side of an on-off valve of a vacuum transmission pipe. Things.

The present invention according to claim 6 provides the invention according to claims 1 to 5
A manhole pump unit in which the sewage storage tank and the pressure pump according to any one of the above are unitized.

[0015]

According to the first aspect of the present invention, the following operations are provided. Install a sewage storage tank and a pump at a location where a large pressure loss occurs in a multistage lift or a large lift climbing step pipe, lift the sewage collected in the storage tank below the lift to the lift ascending by the pumping force of the pump, Convey to the downstream side of the water pipe. As a result, the pressure loss in the stepped pipe can be reduced, and shallow burial, which is the greatest merit of the vacuum type sewer system, can be performed throughout the system. In addition, the sewage transfer distance of the vacuum sewer system can be extended. In addition, the vacuum station can be installed in the treatment plant instead of the middle part of the vacuum sewer pipe, the vacuum force of the vacuum station can be exerted on the entire system, and a large power supply by providing a single vacuum station in the middle part of the vacuum sewer pipe It is not necessary to prepare water for sealing the vacuum.

According to the second aspect of the present invention, the following operations are provided. The sewage flowing into the sewage storage tank from the upstream side is stored in a lower part of the tank, and is conveyed to the downstream side through a sewage pressure pipe by a pressure pump. On the other hand, the air flowing in with the sewage is separated into gas and liquid in the upper space of the tank, and is conveyed downstream by a vacuum transmission pipe. That is, the stepped pipe of the multi-stage lift or the large lift becomes a double pipe of the sewage pumping pipe and the vacuum transmission pipe. As a result, the vacuum pressure on the downstream side of the vacuum sewer pipe is smoothly transmitted to the upstream side by the vacuum transmission pipe through which the wastewater does not pass, and the pressure loss due to the wastewater does not occur.

According to the third aspect of the present invention, the following operations are provided. The pump turns on / off the upper and lower sewage level detection switches.
Turns on / off in conjunction with turning off and intermittent operation. As a result, the pump will intermittently discharge the sewage stored in the sewage storage tank by a fixed amount, and the sewage discharged downstream will be smoothly mixed with gas and liquid by the subsequent air in a relatively small lump. Make it possible. This makes it possible to avoid the occurrence of a water block (water seal) that makes it impossible to supply vacuum pressure to the upstream side due to stagnation of sewage lumps on the downstream side of the vacuum sewer pipe.

According to the present invention, the following effects are obtained. When the vacuum pressure on the terminal side cannot be obtained from the sewage storage tank, the vacuum pressure can be supplied by the auxiliary vacuum pump without adding a vacuum station. The auxiliary vacuum pump can be simply reduced in size, for example, with a small power supply, and can easily implement measures against terminal vacuum. In addition, it is possible to cope with the expansion of the end pipe in the future.

According to the fifth aspect of the present invention, the following operations are provided. The exhaust of the auxiliary vacuum pump may be released to the atmosphere after deodorization, but by sending it to the downstream side of the vacuum transmission pipe, the wastewater pumped to the wastewater pumping pipe functions as an air source for mixing gas and liquid, and the wastewater is discharged. Air blowing makes it possible to avoid the generation of water blocks, and eliminates the need for air release after deodorization.

According to the present invention, there is provided the following operation. By integrating the sewage storage tank and the pressure pump with the manhole pump unit, a vacuum type sewer system can be easily constructed.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram showing a first embodiment, FIG. 2 is a schematic diagram showing a second embodiment, FIG. 3 is a schematic diagram showing a third embodiment, and FIG. FIG. 5 is a schematic view showing a vacuum valve unit.

As shown in FIG. 4 and FIG.
Sewage discharged from homes, factories, etc. is sent from a sewage inflow pipe 100 of a natural flow type to a sewage tank 10
The sewage collected in the sewage tank 102 is collected in a water collecting tank 105 of a vacuum station 104 by a vacuum sewage pipe 103 and then sent to a sewage treatment plant or the like by a pressure pump 106.

A vacuum valve 107 is installed in the vacuum valve unit 101, and is disposed between a sewage suction pipe 108 rising from the bottom of the sewage tank 102 and a vacuum sewage pipe 103 connected to a vacuum pump 109 of a vacuum station 104. Is opened and closed by the vacuum valve 107. The opening and closing of the vacuum valve 107 is selectively performed by a vacuum valve controller 110 via a vacuum pressure hose 111.
3 is carried out by introducing the vacuum pressure into the vacuum valve 107 or introducing atmospheric pressure into the vacuum valve 107 via the atmospheric pressure hose 112.

That is, the pressure in the water level detecting tube 113 rises due to the rise of the sewage in the sewage tank 102, and this rise in pressure is sent through the detection hose 114 to the vacuum valve controller 11.
0, an internal switch (not shown) in the vacuum valve controller 110 operates to operate the vacuum drain 103
The internal vacuum pressure is guided to the vacuum valve 107 via the vacuum valve controller 110 via the vacuum pressure hose 111. Then
The vacuum valve 107 moves a valve body (not shown) against a spring force of a spring (not shown) and opens the valve.

On the other hand, when the water level in the sewage tank 102 drops, the pressure in the water level detection pipe 113 drops, so that the internal switch in the vacuum valve controller 110 stops, and the vacuum drain pipe 103 moves from the vacuum drain pipe 103 to the vacuum valve controller 110. The vacuum pressure does not act, and the breather pipe 115
Via the vacuum valve controller 110 via the vacuum valve 107
Atmospheric pressure is introduced. Then, this vacuum valve 107 is
The valve element is moved backward by the spring force to close the valve.

The reference numeral 116 in FIG.
A check valve that applies a vacuum pressure only from 03 to the vacuum valve controller 110, and reference numeral 117 denotes a vent pipe.

That is, in the case of the vacuum type sewer, when the communication part 110 between the sewage suction pipe 108 of the sewage tank 102 and the vacuum sewage pipe 103 is opened by the vacuum valve 107 as described above, the vacuum sewage pipe The vacuum pressure applied to 103 reaches the sewage suction pipe 108, and the sewage and air in the sewage tank 102 are sucked into the vacuum sewer 103 in order, and the pressure difference between the vacuum pressure in front of the sewage and the suction air pressure behind the sewage is reduced. The resulting pumping force enables the wastewater to be transported as a gas-liquid mixed flow. Hereinafter, the manhole pump unit 10 provided at an intermediate portion of the vacuum sewer 103 will be described.

(First Embodiment) (FIG. 1) The manhole pump unit 10 is provided at an intermediate portion between the upstream pipeline 11 and the downstream pipeline 12 of the vacuum drain 103. The upstream pipeline 11 and the downstream pipeline 12 are formed by arranging shallow buried saw-toothed pipelines adopting uphill pipes (lifts) almost along the terrain. In particular, the downstream pipeline 12 is a large-scale crossing a river. It was attached to a bridge.

The manhole pump unit 10 has a sewage storage tank 13 at an intermediate portion between an upstream pipe 11 and a downstream pipe 12. The sewage storage tank 13 is kept completely airtight. Since the level of the upstream pipeline 11 is high, the sewage storage tank 13 needs only to be buried shallowly.

The sewage storage tank 13 is provided with a pressure pump 14. The pressure pump 14 pumps the sewage stored in the tank 13 to the downstream pipe 12. The pump 14 may be a submersible pump type or a type installed outside a tank.

Between the sewage storage tank 13 and the downstream pipe 12, a sewage feed pipe 15 extending from the pressure pump 14 to the downstream pipe 12, and an upper space of the sewage storage tank 13 (gas-liquid separation layer 13 A) And a vacuum transmission pipe 16 extending from the first pipe to the downstream pipe 12 so as to form a double pipe.

The air flowing from the upstream pipe 11 into the wastewater storage tank 13 in a gas-liquid mixed flow state is separated in the upper space 13A of the tank 13 and sent to the downstream pipe 12 through the vacuum transmission pipe 16. Can be The vacuum pressure in the downstream pipe 12 is transmitted to the upstream pipe 11 through the vacuum transmission pipe 16.

Upper and lower sewage level detection switches 17A and 17B are provided above and below the sewage storage tank 13. The control panel 18 (a) turns on the pump 14 by turning on the upper sewage level detection switch 17A, and (b) turns on the pump 1 by turning off the lower sewage level detection switch 17B.
Turn 4 off. Upper and lower sewage level detection switches 17A,
As the level difference of 17B is small, the pressure pump 14 is operated intermittently, and the sewage discharged from the sewage storage tank 13 is made small to prevent the generation of a water block. Sewage storage tank 1
3 upper space 13A is provided with an upper sewage level detection switch 17
A is divided by the installation level of A.

In order to maintain the manhole pump unit 10, the sewage pumping pipe 15 and the vacuum transmission pipe 16 are provided with gate valves 15A and 16A. At the time of any maintenance of the manhole pump unit 10, the gate valve 16A is closed to keep the downstream pipe 12 of the vacuum drain 103 normal. At this time, the gate valve 15A is also closed to prevent the occurrence of pressure loss such that the vacuum pressure in the downstream pipe 12 sucks sewage through the pressure feed pump 14.

At the upper part of the manhole pump unit 10, a cleaning port 19 for maintaining the tank is provided. It is desirable that the number of the pressure pumps 14 be two including the spare.

The manhole pump unit 10 operates as follows. (1) The sewage conveyed by the upstream pipeline 11 is temporarily stored in the sewage storage tank 13.

(2) When the sewage level in the sewage storage tank 13 rises and the upper sewage level detection switch 17A is turned on, the pressure pump 14 is turned on, and the sewage in the tank 13 passes through the sewage pressure feed pipe 15 to the downstream pipe 12. Pumped. The sewage pumped into the downstream pipe 12 naturally flows down, for example, a 0.2% gradient of the downstream pipe 12 to the front lift section, and the air pressure reaching the rear of the sewage from the vacuum transmission pipe 16 and the vacuum sewage pipe By means of a pumping force based on a pressure difference from a vacuum pressure applied in front of the sewage by the sewage 103, the sewage is conveyed so as to rise upward from below.

(3) When the sewage level in the sewage storage tank 13 decreases and the lower sewage level detection switch 17B is turned off, the pump 14 is turned off. As a result, the vacuum pressure in the downstream pipe 12 is reduced by the vacuum transmission pipe 16 and the sewage storage tank 1.
3 to the upstream pipe 11 and the upstream pipe 11
The sewage is transported from the tank to the sewage storage tank 13.

Therefore, according to the present embodiment, the following operations are provided. A sewage storage tank 13 and a pump 1
4 is provided, the sewage collected in the storage tank 13 below the lift is lifted up to the lift by the pumping force of the pump 14, and is conveyed to the downstream side of the vacuum sewer 103. As a result, the pressure loss in the stepped pipe can be reduced, and shallow burial, which is the greatest merit of the vacuum type sewer system, can be performed throughout the system. In addition, the sewage transfer distance of the vacuum sewer system can be extended. Further, the vacuum station can be installed in the treatment plant instead of the intermediate portion of the vacuum sewer pipe 103, and the vacuum force of the vacuum station can be exerted on the entire system.
By providing a single vacuum station in the middle part of 03, it is not necessary to prepare a large power supply or water sealing water for reaching vacuum.

The sewage flowing into the sewage storage tank 13 from the upstream side is stored in a lower portion of the tank 13 and is supplied to the pressure pump 1.
4 transports downstream through the sewage pumping pipe 15.
On the other hand, the air flowing in with the sewage is separated into gas and liquid in the upper space 13A of the tank 13 and is conveyed downstream by the vacuum transmission pipe 16. That is, the ascending pipe of the multi-stage lift or the large lift becomes a double pipe of the sewage pumping pipe 15 and the vacuum transmission pipe 16. As a result, the vacuum pressure on the downstream side of the vacuum sewer 103 is smoothly transmitted to the upstream side by the vacuum transmission pipe 16 through which the wastewater does not pass, thereby causing a pressure loss due to the wastewater.

The pressure feed pump 14 is turned on / off in conjunction with the on / off of the sewage level detection switches 17A and 17B, and intermittently operates. As a result, the pumping pump 14 intermittently discharges the sewage stored in the sewage storage tank 13 by a fixed amount, and the sewage discharged to the downstream side is smoothly gas-liquid discharged by the subsequent air in a relatively small lump. Can be mixed. This makes it possible to avoid the occurrence of a water block (water seal) that makes the stagnation of sewage stagnant on the downstream side of the vacuum sewer 103 and makes it impossible to supply vacuum pressure to the upstream side.

Since the sewage storage tank 13 and the pressure pump 14 are unitized in the manhole pump unit 10, a vacuum type sewer system can be easily constructed.

(Second Embodiment) (FIG. 2) In the second embodiment, the manhole pump unit 10 of the first embodiment further includes an auxiliary vacuum pump 21 communicating with the upper space 13A of the sewage storage tank 13, and The electric on-off valve 2 is located downstream of the gate valve 16A of the vacuum transmission pipe 16.
2 was provided. In addition, the upper space 13 of the sewage storage tank 13
A pressure sensor 23 for detecting the pressure of A
Pressure sensor 24 for detecting the pressure downstream of the on-off valve 22
With.

The manhole pump unit 10 operates in the following manner in addition to the operation of the first embodiment. (1) The internal pressure of the sewage storage tank 13 detected by the pressure sensor 23 (due to the occurrence of a water block in the vacuum sewage pipe 103, the inflow of sewage above a predetermined amount, etc.) a constant value (the end of the vacuum type sewage system is normal). When the pressure drops below the vacuum pressure level at which the auxiliary vacuum pump can operate, the on-off valve 22 is closed and the auxiliary vacuum pump 21 is turned on. Thereby, the sewage storage tank 1
When the internal pressure of the pump 3 is restored to a constant value, the auxiliary vacuum pump 2
Turn 1 off.

(2) The vacuum pressure generated in the sewage storage tank 13 in (1) above causes the sewage storage tank 1
When the internal pressure of the tank 13 becomes equal to the downstream pressure (vacuum pressure of the downstream pipe 12) by the on-off valve 20 of the vacuum transmission pipe 16 detected by the pressure sensor 24, The on-off valve 22 is opened. In this way, the vacuum pressure of the sewage storage tank 13, the degree of vacuum of which has been increased by the auxiliary vacuum pump 21, reaches the downstream pipe 12, and the backflow of the sewage already conveyed to the downstream pipe 12 can be prevented.

Therefore, according to the present embodiment, the following operations are provided. When the vacuum pressure on the terminal side cannot be obtained from the sewage storage tank 13, the vacuum pressure can be supplied by the auxiliary vacuum pump 21 without adding a vacuum station. The auxiliary vacuum pump 21 can be simplified and reduced in size, for example, with a small power supply, and can easily implement a countermeasure against terminal vacuum. In addition, it is possible to cope with the expansion of the end pipe in the future.

(Third Embodiment) (FIG. 3) In the third embodiment, the exhaust pipe 2 of the auxiliary vacuum pump 21 is further provided in the manhole pump unit 10 of the second embodiment.
5 was connected to the downstream side by the on-off valve 20 of the vacuum transmission pipe 16.

When the auxiliary vacuum pump 21 is operated, the vacuum pressure in the upstream pipe 11 rises, the sewage conveying capacity in the upstream pipe 11 is improved, and the auxiliary vacuum pump 21 The exhaust pressure (air pressure) is
It acts as a pumping force for air-blowing the sewage inside. Here, the exhaust gas supplied from the auxiliary vacuum pump 21 to the downstream pipe 12 is originally supplied to the sewage tank 102.
From the air supplied to the vacuum sewer 103 from
This exhaust pumping does not increase the overall gas-liquid ratio in the vacuum sewer 103.

Therefore, according to the present embodiment, the following operations are provided. The exhaust of the auxiliary vacuum pump 21 is
6, the sewage pumped to the sewage pumping pipe 15 is made to function as an air source for mixing gas and liquid, and the sewage is blown by air so that the generation of a water block can be avoided. After deodorization, air release is unnecessary.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and the design may be changed without departing from the scope of the present invention. The present invention is also included in the present invention. For example, the pump 14 and the auxiliary vacuum pump 21 are connected to the sewage storage tank 1.
3 may be provided inside or outside.

[0051]

As described above, according to the present invention, when a multi-stage lift or a large lift is employed in a vacuum type sewer system, the pressure loss of a stepped pipe can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a first embodiment.

FIG. 2 is a schematic diagram showing a second embodiment.

FIG. 3 is a schematic diagram showing a third embodiment.

FIG. 4 is a schematic diagram showing a vacuum type sewer system.

FIG. 5 is a schematic view showing a vacuum valve unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Manhole pump unit 13 Sewage storage tank 14 Pumping pump 15 Sewage pumping pipe 16 Vacuum transmission pipe 17A, 17B Sewage level detection switch 21 Auxiliary vacuum pump 22 On-off valve 25 Exhaust pipe 103 Vacuum sewer pipe

Claims (6)

[Claims] 1. A vacuum sewer system in which a vacuum sewer pipe is connected to a vacuum source, wherein a sewage storage tank is provided at an intermediate portion of the vacuum sewage pipe, and sewage stored in the sewage storage tank is downstream of the vacuum sewage pipe. A vacuum type sewer system comprising a pressure pump for pressure feeding. 2. A sewage pumping pipe extending from the pump to a downstream section of the vacuum sewer pipe between the sewage storage tank and a downstream section of the vacuum sewage pipe, and a downstream section of the vacuum sewage pipe from an upper space of the sewage storage tank. 2. A vacuum sewer system according to claim 1, wherein a vacuum transmission pipe extending in parallel is provided. 3. A sewage level detection switch is provided above and below the sewage storage tank, a pump is turned on by turning on an upper sewage level detection switch, and is turned off by turning off a lower sewage level detection switch. 3. The vacuum sewer system according to 1 or 2. 4. An auxiliary vacuum pump communicating with an upper space of the sewage storage tank is provided, and an on-off valve is provided on the vacuum transmission pipe, and the on-off valve is closed when an internal pressure of the sewage storage tank falls below a predetermined value. Turn on the auxiliary vacuum pump, turn off the auxiliary vacuum pump when the internal pressure of the sewage storage tank reaches a certain value,
The on-off valve is opened when the internal pressure of the sewage storage tank becomes equal to the pressure downstream of the on-off valve of the vacuum transmission pipe.
The described vacuum sewer system. 5. The vacuum sewer system according to claim 4, wherein an exhaust pipe of the auxiliary vacuum pump is connected to a downstream side of an on-off valve of a vacuum transmission pipe. 6. A manhole pump unit comprising the sewage storage tank according to claim 1 and a pressure pump.