JP3530826B2 - Simple rainwater pumping station - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a simple rainwater pumping station.

[0002]

2. Description of the Related Art Rainwater pumping stations are important facilities for removing inundation in urbanized areas. It is usually a large-scale facility equipped with a large-capacity pumping pump and a large settling ground. Although the rainwater pumping station is an indispensable facility, there are many obstacles to its installation due to its vast installation site, large construction cost, and long construction period. In addition, in rainwater pumping stations, the capacity of pump wells is large and the capacity of pump wells in which pumps are installed is generally required to be large in order to secure an interval between starting and stopping pumps.

[0003]

SUMMARY OF THE INVENTION The present invention is simplified by a large submersible pump and a vertical shaft by an underwater excavation method, securing a pumping capacity by connecting a plurality of vertical shafts, and positively utilizing a return pipe to compensate for a lack of pump well capacity. It enables a rainwater pumping station. As a result, the construction cost of the rainwater pumping station facility can be significantly reduced, the required land space can be reduced, and the construction period can be shortened.

Furthermore, it is possible to promptly remove rainwater from areas with high urgency, and the scale of not only rainwater pump stations but also rainwater pipe maintenance itself can be reduced. It is a system that makes it possible to make the entire rainwater removal system cheaper, faster and more tailored to the needs of residents.

[0005]

SUMMARY OF THE INVENTION In order to reasonably reduce the capacity of a pump well, the present invention provides a pump discharge pipe with a return pipe to the pump well and an electric valve that works in conjunction with the water level. The return pipe returns some or all of the pumped water to the pump well to prevent the pump from stopping due to a drop in the water level, and to eliminate the problem of pump start / stop intervals. The positive use of this return pipe can significantly reduce the capacity of the pump well.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail with reference to the embodiments shown in the drawings. A simple rainwater pumping station according to an embodiment of the present invention is shown in FIGS. Figure 1
1 is a plan view of a simple rainwater pumping station according to this embodiment, and FIG.
Medium AA line sectional view, FIG. 3 is a BB line sectional view in FIG. 1, FIG. 4 is a CC line sectional view in FIG. 1, and FIG. 5 is an operation of the simple rainwater pumping station according to the present embodiment. FIG.

As shown in FIG. 1, within the site boundary indicated by the chain double-dashed line, three pump wells 10 and one inflow hole 20 are provided underground, and each pump well 10 has a submersible pump 30. Is installed. The pump well 10 is a shaft by an underwater excavation method using a casing made of steel or concrete represented by the Kecom method and the art method, and a shaft bottom plate 12 is provided on the bottom surface thereof.

The vertical shaft referred to here is constructed by a non-cutting technique represented by a propulsion method instead of the conventionally used open-cutting method. As a vertical shaft construction, the copper sheet pile construction method and the liner plate construction method were used, but due to the improvement of the busy construction conditions and construction environment,
In recent years, the Kecom method, the PIT method, the art method, etc. have been developed. These construction methods, for example, while press-fitting a cylindrical concrete or steel casing while swinging into the ground, while excavating the ground in a hemispherical bucket while pouring water into the casing, The cylindrical casing may be pressed into the ground while rotating in a horizontal plane.

Therefore, by constructing the pump well 10 as a vertical shaft by an underwater excavation method, it is possible to construct the well in a narrow and limited space on the road in a short time. The reason for excavating the vertical shaft while pouring water is to excavate while maintaining balance with the groundwater pressure. Also, after excavating the shaft,
By pouring concrete, a vertical shaft bottom plate 12 is provided, and a pump upper foundation and a lid are provided on the upper part of the pump well 10.

The lower portions of these pump wells 10 are connected to each other by a communication pipe 11, and the lower portions of one pump well 10 and an inflow hole 20 are connected by a water conduit 21.
A sand pool (sand settling ground) 22 and a screen 24 are provided at the bottom of the inflow person hole 20, and an inflow pipe 23 is connected to the upper portion thereof. The submersible pump 30 is provided in the sand pool 22 by precipitating sand and mud in rainwater flowing from the inflow pipe 23.
It prevents the wear of. The screen 24 removes dust and the like other than sand and mud.

Therefore, the inlet hole 20 is introduced through the inlet pipe 23.
After the sand and dust of the rainwater that has flowed into the water are removed by the sand pool 22 and the screen 24, the water conduit 21 and the communication pipe 1
1 and flow into each pump well 10. Incidentally, the sand, mud and dust accumulated in the sand pool 22 and the screen 24 are regularly discharged by vacuum or the like for maintenance. Submersible pump 30 installed in each pump well 10
Is for pumping rainwater that has flowed into the pump well 10 and guiding it through a discharge pipe 40 to a water discharge destination such as a river, and has a built-in electric motor or engine.

As the submersible pump 30, well-known submersible pumps can be widely used. There are various types of impellers that use a mixed flow / axial flow type, ones in which an electric motor and an impeller are directly connected, and ones in which a speed reducer is provided. A column pump can be used, and a column pump is particularly preferable. Since the submersible pump 30 does not require a shed for installing the pump, there is an advantage that the installation area can be small. In order to control the electric motor or engine of the submersible pump 30, as shown in FIG. 1, an operation panel installation stage 100 is provided on the ground within the site boundary, and an operation panel 110 is provided thereon. On the operation panel 110,
An electric panel for receiving and transforming / distributing the submersible pump 30 is provided.

The submersible pump 30 must be stopped when the water level in the pump well 10 falls below a certain level because the electric motor or the engine becomes insufficiently cooled when the water level falls below a certain level, and in order to protect the pump, There is a problem with the start / stop interval that it takes a certain time to restart after being stopped. In the present invention, in order to solve the problem of the start / stop interval, part or all of the rainwater to be discharged from the discharge pipe 40 is returned to the return pipe 5.
It returns to the pump well 10 at 0, and the water level of the pump well 10 is always kept above a certain level.

That is, a return pipe 50 is arranged between the discharge pipe 40 and one pump well 10, and an electric butterfly valve 51 is interposed in the return pipe 50. On the other hand, the pump well 10 is provided with an input water level gauge 60 for detecting the water level, and the water level detected by the input water level gauge 60 is transmitted to the controller 70 incorporated in the operation panel 110 described above. It is like this. The controller 70 controls the electric butterfly valve 51 so that the problem of insufficient cooling of the submersible pump 30 does not occur when the water level in the pump well 10 falls below a certain level based on the water level detected by the input water level gauge 60. And the rainwater to be discharged from the discharge pipe 40 is temporarily returned to the pump well 10 by the return pipe 50.

On the other hand, if the water level in the pump well 10 is above a certain level, the electric butterfly valve 51 is closed to prevent rainwater from returning to the pump well 10 from the return pipe 50. Therefore, since the water level in the pump well 10 is maintained above a certain level, the problem of insufficient cooling of the submersible pump 30 does not occur, and the above-mentioned start / stop problem does not occur. A check valve 41 and a manual butterfly valve 42 are provided in each discharge pipe 40.
1, a valve bit and a lid 43 for accommodating the manual butterfly valve 42
Is provided. Further, the discharge pipe 40 is provided with a flexible pipe 80 in order to prevent shear fracture due to temperature change,
An expansion tube 90 is provided to prevent backflow.

The facility plan of the above-mentioned simple rainwater pumping station is as follows. (1) A precast concrete ring is used alone or in series for the temporary steel shaft for the construction of the pump station structure manhole. The advantage is that the construction speed is increased by using the structure that is normally used as a temporary structure as a main structure, and that a manhole with a larger diameter than the normal manhole structure can be built,
Since it is possible to perform underwater excavation + underwater concrete placement, it is possible to minimize the adverse effects on the surrounding area during excavation. The construction time is extremely short, and it takes about half a year to build the pumping station frame in-situ, including the construction of the parts that would take two years, including the construction of the attached valve pit.

Therefore, it is possible to complete the process in a single year, including the pump equipment. In the case of the normal cast-in-place type, the standard is 3 years including the equipment, so the construction period is 1/3 in the present invention. Currently, in the shaft by the excavation method, it is possible to construct a shaft with a diameter of 3000 mm and a depth of 16 m. With this size, the maximum diameter per shaft is 1200.
Submersible pumps up to mm can be installed. In this case, with a lifting height of 5 m, 200 m ³ / min per vertical shaft (drainage area of about 30
equivalent to ha). Also, if the pump diameter is reduced to 900 mm, the pumping capacity will drop to 100 m ³ / min (equivalent to a drainage area of about 15 ha), but the pump head will be 20 m.
Can be secured.

The pumping capacity can be dealt with by connecting vertical shafts in series. With the PC well construction method, it is possible to construct up to a diameter of 6000 mm and a depth of about 30 m. However, due to the balance with the pump capacity, it can be said that a normal pump station is desirable in this series. Therefore, it is appropriate to select the vertical shaft by the excavation method as the target method. As described above, the pump shaft can increase pumping capacity by connecting the shafts in series.

In the same manner, a pretreatment tank can be secured when pretreatment such as sedimentation and rustiness is required. The pump well as the body of the pump well does not project to the ground, and can be an almost complete underground structure. For the check valve / valve of the submersible pump, a small concrete pit is used separately.
If necessary, install a screen and a pretreatment shaft for sand traps. Sand removal is done with a vacuum car.

(2) Pump facility As the submersible pump, for example, a column pump is used. It can be said that the column pump is more suitable because of its installation space. Since the pump well is small, there is a problem with the start / stop interval of the pump. Therefore, a return pipe with an electric valve linked with the water level will be installed. It is necessary for the return pipe to have a diameter that can secure the amount of return based on the operation plan of the pump facility. For loading / unloading / maintenance of pumps, it is recommended to use mobile cranes for relatively small diameter pumps and stationary gate type cranes for large diameter pumps.

(3) Electric equipment The electric panel for receiving and transforming / distributing electricity is installed outdoors for the purpose of reducing the construction cost and simplifying the facility. Private power generation facilities will be installed as necessary. As for the private power generation facility, a portable type can be used with a small capacity.
It is recommended to install a simple building when installing private power generation equipment at all times. It is desirable to establish bases and centralize monitoring and control. This is because, in the present invention, it is considered that a plurality of rainwater pump stations will be built because the drainage area is subdivided. In order to prevent flooding of equipment, the height of flood protection should be set reasonably and a concrete frame should be installed.

(4) Arrangement Planning The vertical shafts have a structure in which they are connected in series by communication pipes. The projecting part above the ground will be the electric panel, private power generation equipment, gate operation console, etc. The upper part of the pump well will be covered with a lid, and work will be performed from the ground during maintenance. With such a plan, the site of the pumping station will be significantly reduced, and at a scale of 60 m ³ / min, it will be about 1
It can be built in the required area of / 10. Due to the peculiarity of the installation method, it is possible to build it even in the vicinity of the house. The possible depth is influenced by the possible depth of the construction method and the pump head, and is defined as approximately 12 to 13 m to the upper end of the pump well bottom plate. The pretreatment tank needs to be kept at about 7 m in consideration of sand lifting by a standard vacuum car, and from this point, the height of the bottom of the inflow conduit is regulated at about 6 m below the ground.

(5) Outlet plan River consultation is required. If it is necessary to cross over the existing body,
It is possible to use a plurality of small-section pressure-feeding pipes as the discharge pipe, and to carry over without breaking the section of the feeder ruler.

[0024]

[Table 1]

The effectiveness of the simple rainwater pumping station of the present invention is shown in Table 1 when designed at a scale of 60 m ³ / min.
Is the street. The scale of this scale is about 10-2
It corresponds to 0 ha. The controls were: -A standard rainwater pumping station of similar scale. As shown in the results of Table-1, it can be seen that significant effectiveness is recognized.

The applicability of the simple rainwater pumping station of the present invention is as follows. Efficient rainwater removal Due to the above economic efficiency, land saving, and short construction period, it is possible to deal with drainage countermeasures in areas where inundation problems have become apparent but facilities could not be dealt with.

Reconstruction of rainwater removal Although it is a well-developed area, it is possible to cope with the reconstruction of an area where the frequency of inundation is increasing due to an increase in runoff coefficient due to urbanization, insufficient capacity of existing pipes, and lack of land (relief pump Place).

Review of rainwater removal plan Although the rainwater plan was drafted, the regions that are postponed due to their economic efficiency and pumping station site are divided into regions and developed in order of importance. I do.
There is a possibility that the scale (pipe diameter / installation depth) of the drainage plan can be significantly reduced.

Review of existing rainwater pumping station facility When increasing the capacity of an existing rainwater pumping station, it is possible that the capacity can be increased while the site space is limited.

[0030]

As described above in detail with reference to the embodiments, according to the simple rainwater pumping station of the present invention, a large submersible pump, a vertical shaft by an underwater excavation method, and a pumping capacity by connecting a plurality of vertical shafts. A simple rainwater pumping station will be enabled by securing and securing the capacity of the pump well and using the return pipe positively. As a result, the construction cost of the rainwater pumping station facility can be significantly reduced, the required land space can be reduced, and the construction period can be shortened. In addition, it will be possible to promptly remove rainwater from areas with high urgency, and the scale of not only rainwater pump stations but also rainwater pipe maintenance itself can be reduced. In other words, the present invention is a system that makes it possible to make the entire rainwater removal system cheaper, faster, and more suited to the needs of residents.

[Brief description of drawings]

FIG. 1 is a plan view of a simple rainwater pumping station according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a sectional view taken along line BB in FIG.

FIG. 4 is a sectional view taken along the line CC in FIG.

FIG. 5 is an operation explanatory view of the simple rainwater pumping station according to the present embodiment.

[Explanation of symbols]

10 pump wells 20 Inflow hole 30 submersible pumps 40 discharge pipe 50 Return pipe 60 Water level meter 70 controller 80 Flexible tube 90 Expansion tube 100 Operation panel installation stage 110 Operation panel

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenichi Yoshimura 3-31-7 Negishi, Urawa-shi, Saitama Littleheim 102 (56) Reference JP-A-7-324375 (JP, A) JP-A-8-41973 ( JP, A) Actual Kaihei 4-76998 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) E03F 5/10 E03F 5/22 F04D 15/00

Claims (2)

(57) [Claims] 1. An underwater pump is connected to a plurality of shafts by an underwater excavation method, and an underwater pump is installed in each shaft, and an inflow pipe is connected to at least one of the shafts via a sand trap, When each discharge pipe is guided to a discharge destination, and further, a return pipe is provided between the discharge pipe and the inside of the shaft and an electric valve is provided in the return pipe, and the water level in the shaft falls below a certain level. A simple rainwater pumping station, wherein part of the rainwater to be discharged from the discharge pipe is returned to the vertical shaft by opening the electric valve. 2. The simple rainwater according to claim 1, wherein the vertical shaft is formed by an underwater excavation method in which a cylindrical casing is press-fitted into the ground and water is poured into the casing for excavation. Pumping station.