JP3976605B2 - Flow control method in combined sewer system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flow rate control method in a combined sewer where sewage such as domestic wastewater and rainwater flow together.
[0002]
[Prior art]
Conventionally, the main line of the combined sewer system forms a flow path where the sewage flowing from the branch line flows to the sewage treatment plant, and mainly sewage such as domestic wastewater flows as sewage in fine weather, Drainage and rainwater merge and flow as sewage. At this time, the sediments of the branch line and the main line flow as a first flush, so if the sewage increased by the rainwater flowing in from the branch line is directly sent from the main line to the sewage treatment plant, the sewage treatment plant Since the treatment capacity was exceeded and the processing capacity was exceeded, excess sewage was discharged into public water areas (rivers, seas, etc.) without being treated.
[0003]
[Problems to be solved by the invention]
By the way, if the sewage is discharged into the public water area without being treated, the water quality of the public water area may be deteriorated due to contamination of the untreated sewage. As a countermeasure to this problem, a reservoir and storage pipe are provided separately from the main pipeline, and the sewage increased due to rainfall is temporarily stored in the reservoir and storage pipe, and then gradually from the reservoir and storage pipe. Water is sent to the sewage treatment plant. However, in recent years, the construction of special facilities for temporary storage, such as stagnation ponds and storage pipes, has a problem that it is difficult to secure a construction site, especially in urban areas, and that a huge amount of cost is required for the construction. There is.
[0004]
The present invention solves the above-mentioned problem, and without providing a special storage facility such as a reservoir or a storage pipe, an increase in sewage that increases during rainfall stays in the main pipeline and can be processed. It aims at providing the flow control method in the combined sewer which can be supplied to a sewage treatment plant.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the flow rate control method in the combined sewer system of the present invention according to claim 1 is an indicator of either the rainfall amount or the flow rate or the water level of the sewage flowing through the main pipeline during rainfall in the combined sewer system. as it der controls the opening of the flow control means provided in the middle of the trunk line, with at least rainfall placing the door body of the flow control means in the closed position, through a small opening provided in the door body A small amount of water is passed through the main line on the downstream side, and when it rains, the main line upstream of the door body when the flow rate of sewage flowing through the main line is less than the set flow rate or less than the set flow rate While storing the sewage flowing into the main line using the pipeline as a storage area, a small amount of water is passed through the small opening to the main line on the downstream side, and the flow rate of sewage flowing through the main line exceeds the set flow rate. If the water level is higher than the set water level Or the total amount through water disposed in the fully open position the door body when, rainfall, flow rate, and increases the opening degree gradually following the increase of the water level.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, a main pipe 1 of a combined sewer formed in the ground forms a flow path for sewage flowing from a branch pipe to a sewage treatment plant. Sewage flows, and when it rains, domestic wastewater and rainwater merge to flow as sewage.
[0008]
Vertical shafts of special human holes 2 are formed in the middle of the main line 1 at appropriate intervals. Each special human hole 2 has a gate 3 for controlling the flow rate of sewage flowing through the main line 1, a water level detector ( A water level meter) 4 and a flow rate detector (flow meter) 5 are provided, and the gate 3 can be provided with a small opening that is normally open in the door body. The rainfall measuring device 6 is provided outside the special human hole 2, and the water level detector (water level meter) 4, the flow rate detector (flow meter) 5, and the rainfall measuring device 6 may be provided with any of them. .
[0009]
The control device 7 controls the opening degree of the gate 3, and the opening degree is set using one of the measured values of the water level detector (water level meter) 4, the flow rate detector (flow meter) 5, and the rainfall measuring device 6 as an index. Take control. Each control device 7 transmits and receives data and control signals to and from the central management center 8 through a communication line.
[0010]
With the above configuration, the sewage flowing through the main line 1 during non-rainfall or low rainfall mainly flows sewage such as domestic wastewater at a low flow rate, and includes a water level detector (water level meter) 4 and a flow rate detector (flow meter). 5. All the measured values of the rainfall measuring device 6 are below the set value.
[0011]
For this reason, the control apparatus 7 arrange | positions a door body in the small opening position in the gate 3 which does not have a small opening, and passes a small amount of the sewage which flows from the upstream to the downstream main line 1, and opens a small opening. In the gate 3 having the door, the door body is disposed at the fully closed position, and a small amount of sewage flowing from the upstream is passed through the small opening to the downstream main line 1.
[0012]
The sewage flowing through the main line 1 during rainy rain increases when rainwater joins the domestic wastewater. For this reason, in the state where the measured values of the rainfall measuring device 6, the flow rate detector (flow meter) 5, and the water level detector (water level meter) 4 are not more than the set values, the control device 7 is in the gate 3 having no small opening. Holds the door body in a small opening position, holds the door body in the fully closed position in the gate 3 having a small opening, and collects sewage flowing from the branch line into the main line 1 or sewage flowing from the upstream. The main line 1 upstream of the gate body of the gate 3 is stored as a storage area, and in the gate 3 having no small opening, a small amount of sewage is passed from the small opening to the main line 1 downstream. In the gate 3 having a small opening, a small amount of water is passed through the small opening to the downstream main line 1.
[0013]
This prevents the branch line flowing as the first flush at the beginning of the rain, the sediment of the main line 1 and the increased amount of sewage from flowing to the sewage treatment plant at a time.
[0014]
The control device 7 is a gate 3 when any of the measured values of the rainfall amount measuring device 6, the flow rate detector (flow meter) 5, and the water level detector (water level meter) 4 is greater than the set rainfall, greater than the set flow rate, and greater than the set water level. The door body is placed in the fully open position to allow all water to flow, or the opening is gradually increased following the measured value.
[0015]
The operation described above has been described for the case where each control device 7 performs autonomously, but it is also possible to perform the operation remotely from the central management center 8 based on each measurement value.
[0016]
Below, the more concrete Example of this invention is shown. As shown in FIGS. 2 to 4, the main pipeline 1 of the merging sewer formed in the ground has a shaft type special human hole 2 in the middle, and the special human hole 2 is a concrete underground structure. 13 and is provided with a human hole 14 (manhole) for entering and exiting on the top.
[0017]
The underground structure 13 has an inflow port 15 formed in the upstream wall 13a and a discharge port 16 formed in the downstream wall 13b. The main pipeline 1 downstream from the discharge port 16 is connected to a sewage treatment plant (not shown). ).
[0018]
A flap gate 3 having an openable / closable door body 17 is installed inside the special person hole 2. The door body 17 is rotatably supported by a support shaft 19 provided in the left-right direction (width direction) of the special person hole 2.
[0019]
The door body 17 has a rectangular small opening 20 formed at the lower edge of the central portion, and supports a small door body 21 that adjusts the flow rate of the sewage W flowing through the small opening 20 by a plurality of bolts 22 so as to be vertically movable. .
[0020]
The hydraulic cylinder device 23 is attached to the wall 13 a on the upstream side of the underground structure 13. The tip of the piston rod 24 of the hydraulic cylinder device 23 is connected to a crank arm 25 provided at one end of the support shaft 19. As shown in FIG. 5, by projecting the piston rod 24, the door body 17 rotates to the closed position S together with the support shaft 19 to be in a substantially downward posture, and as shown in FIG. 6, the piston rod 24 is retracted. By doing so, the door body 17 is rotated to the fully open position O together with the support shaft 19 to be in a substantially horizontal posture. A counterweight 26 that urges the door body 17 in the opening direction is attached to the support shaft 19 via a link mechanism 27.
[0021]
Hereinafter, the operation of the above configuration will be described. During normal non-rainfall, the piston rod 24 of the hydraulic cylinder device 23 protrudes and the door body 17 rotates to the closed position S. In this state, sewage flows through the small opening 20.
[0022]
When the amount of sewage W increases during rainfall, the door body 17 serves as a weir to form a storage area A in the main pipeline 1 on the upstream side of the door body 17, and temporarily stores the sewage W in the storage area A. The water is passed through the small opening 20 to the downstream outlet 16.
[0023]
A flap gate when any of the measured values of the rainfall measuring device 6, the flow detector (flow meter) 5, or the water level detector (water level meter) 4 exceeds the set rainfall, the set flow, or the set water level due to heavy rain. No. 3 door body 17 is placed in the fully open position to allow all the water to flow, or the opening is gradually increased following the measured value.
[0024]
When the hydraulic cylinder device 23 becomes inoperable due to a power failure, failure or the like with the door body 17 closed, the door body 17 is attached to the counterweight 16 by making the hydraulic cylinder device 23 free. It is urgently opened by the force, and comes into contact with the stopper 28 and is restricted to the fully open position O.
[0025]
Therefore, even if an abnormal situation occurs when the flow rate of the sewage W increases due to heavy rain or the like, it is possible to prevent the living facility upstream of the door body 17 from being flooded.
[0026]
【The invention's effect】
As described above, according to the present invention, it is possible to control the opening degree of the flow rate control means provided in the middle of the main line using as an index either the amount of rainfall or the flow rate or level of sewage flowing through the main line at the time of rainfall. In normal times, a small amount of water will flow to the downstream main line, and during rain, a small amount of water will flow to the downstream main line while storing sewage using the main line upstream of the door as a storage area. It is possible to cope with an increase in sewage during rainfall without providing a special storage facility such as a reservoir or a storage pipe.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a flow rate control method in a combined sewer system according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a special human hole in the combined sewer system.
FIG. 3 is a front view of the special person hole.
FIG. 4 is a plan view of the special human hole.
FIG. 5 is an enlarged view showing a state in which the door of the flap gate of the special person hole is closed.
FIG. 6 is an enlarged view showing a state in which the door of the flap gate of the special person hole is fully opened.
[Explanation of symbols]
1 Main line 2 Special human hole 3 Gate 4 Water level detector (water level meter)
5 Flow rate detector (flow meter)
6 Rainfall Measurement Device 7 Control Device 8 Central Management Center 13 Underground Structure 14 Human Hole 15 Inlet 16 Outlet 17 Door 19 Supporting Shaft 20 Small Opening 21 Small Door 22 Bolt 23 Hydraulic Cylinder 24 Piston Rod 25 Crank Arm 26 Counterweight 27 Link mechanism 28 Stopper

Claims (1)

In the combined sewer system, the amount of rainfall, the flow rate of sewage flowing through the main line at the time of rainfall, or the water level is used as an index to control the opening of the flow control means provided in the middle of the main line , At the time, the door of the flow control means is placed in the closed position, and a small amount of water is passed through the small opening provided in the door to the downstream main line. When the flow rate of water is below the set flow rate or the water level is below the set water level, the main line on the upstream side of the door body is used as a storage area and the sewage flowing into the main line is stored, and the main pipe on the downstream side through the small opening Whether the door is placed in the fully open position and the entire amount of water is passed when the flow rate is greater than the set rainfall and the flow rate of sewage flowing through the main pipeline is greater than the set flow rate or the water level is greater than or equal to the set water level. Gradually following the increase in rainfall, flow, and water level Flow rate control method in the combined sewer system, characterized in that to increase the degree of opening.

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