JP3560463B2 - Air injection method for sewage line of manhole pump - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for injecting air into a sewage pipeline in a sewage pressure pipeline using a manhole pump.
[0002]
[Prior art]
In sewer pipes, sulfates may be reduced by microorganisms in the sewage to generate hydrogen sulfide, and hydrogen sulfide causes a bad smell and corrosion of concrete.
[0003]
In general, the generation of hydrogen sulfide is remarkable in a pressure-feeding pipeline to which oxygen is not supplied, and in some cases, problems related to bad smell and corrosion of concrete have also become apparent.
For this reason, as a measure for preventing or removing hydrogen sulfide, a method of injecting air into a pressure feed line is generally used.
[0004]
[Problems to be solved by the invention]
By the way, in order to inject air into the pressure feeding pipeline, a compressor is required together with the sewage pressure pump, and a place for installing the compressor near the sewage pressure pump is required.
[0005]
Therefore, in the case of the standard pump installed in the pumping station, the installation location of the compressor can be easily secured and the maintenance during the operation of the compressor can be easily performed. Is installed in the manhole, there is no suitable place to install the compressor, and even if an airtight room is installed in the manhole and the compressor is installed, there is a problem that maintenance becomes practically impossible. In the case of a sewage pumping line using a pump, there was a problem that it was difficult to take measures against hydrogen sulfide by the air injection method.
[0006]
SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a method capable of sufficiently injecting air even in the case of a sewage pumping pipe using a manhole pump.
[0007]
[Means for Solving the Problems]
In order to achieve this object, in the present invention, a bypass path is provided in an upright portion of a sewage pumping line to which sewage is supplied from a manhole pump, and a lower communication portion and an upper communication portion of the sewage pumping line of the bypass path are provided. First and second on-off valves are provided, respectively, while third and fourth on-off valves that open into the manhole at the upper and lower ends of the bypass path are provided separately, and the third and fourth on-off valves are provided in the bypass path during operation of the manhole pump. When the sewage is not filled, the first and second on-off valves are opened, the third and fourth on-off valves are closed, and when the sewage is filled in the bypass path, the first and second on-off valves are closed. By closing the second on-off valve and opening the third and fourth on-off valves, the air is forcibly injected into the sewage pipeline when the first and second on-off valves are open. did.
[0008]
According to the present invention, the air remaining in the bypass passage is forcibly injected into the sewage pressure feed pipe as the level of sewage flowing into the bypass rises, so that the air is forced into the sewage pressure feed pipe without using a compressor or the like. It becomes possible to inject air.
[0009]
Also, since no mechanical device such as a compressor is used, no maintenance is required.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of a method for injecting air into a sewage line of a manhole pump according to the present invention will be described.
[0011]
FIG. 1 is a sectional view of an embodiment of an apparatus for carrying out the method of the present invention. In FIG. 1, a manhole pump 2 is provided at a start end of a sewage pumping line 1, and sewage is pumped from a manhole 3 to a next manhole or a final treatment plant (not shown) via an upright portion 1A.
[0012]
A bypass pipe 4 is provided in the upright portion 1A of the sewage pipe 1 and a first and a second communication section 4A and an upper communication section 4B of the bypass pipe 4 with the sewage pipe 1 respectively. On-off valves 5A and 5B are provided.
[0013]
On the other hand, the upper and lower ends of the bypass pipe 4 are provided with third and fourth on-off valves 6A and 6B, respectively, which open into the manhole 3.
In the bypass pipe 4, water level sensors 7A and 7B are provided above and below, and a control device 8 for controlling the opening and closing of the on-off valves 5A, 5B, 6A and 6B based on information from these sensors is provided.
[0014]
Next, the air injection method in the above-mentioned pipe system will be described.
2 to 5 are explanatory sectional views of the process of the present invention. In FIGS. 2 to 5, among the symbols indicating the valves, the valve symbols that are drawn white are open, and the valve symbols that are blackened are closed.
[0015]
FIG. 2 shows a state in which the bypass pipe 4 is not filled with sewage, and the on-off valves 5A, 5B, 6A, and 6B are all closed.
When the manhole pump 2 is driven in this state, the sewage W is pumped to the outside via the upright portion 1A.
[0016]
In this state, the control device 8 opens the first and second on-off valves 5A and 5B of the bypass pipe 4 and closes the third and fourth on-off valves 6A and 6B by the sensor 7A that detects the water level drop. .
[0017]
As shown in FIG. 3, at the same time as the sewage W flows in from the first on-off valve 5A, air is pushed out according to the amount of sewage flowing into the bypass pipe 4 from the second on-off valve 5B, and flows into the sewage to be pumped. Go out.
[0018]
As shown in FIG. 4, when the water level in the bypass pipe 4 rises and reaches the upper sensor 7B, the control device 8 closes the first and second on-off valves 5A and 5B of the bypass pipe 4, and the third and fourth valves. The on-off valves 6A and 6B are opened.
[0019]
As a result, as shown in FIG. 5, the sewage W in the bypass pipe 4 flows down from the third on-off valve 6A into the manhole 3, and the air from the fourth on-off valve 6B enters the bypass pipe 4 to reach the state shown in FIG. Return.
[0020]
Therefore, by repeating the states of FIGS. 2 to 5, air is injected into the sewage pressure feed pipe 1 from the state shown in FIG. 3 to the state shown in FIG.
In the above embodiment, the case where one bypass pipe 4 is provided and air is intermittently injected is shown. However, as shown in FIG. 6, the bypass pipes 4 and 4 are provided on both sides of the upright portion 1A of the sewage pressure feed pipe 1. If the opening and closing timing of the on-off valves 5A to 6B is controlled in opposite phases between these bypass pipes, air can be continuously injected into the sewage pressure feeding pipe.
[0021]
【The invention's effect】
As described above, according to the method of the present invention, the bypass pipe is provided in parallel with the sewage pressure feed pipe, and air can be injected into the sewage pressure feed pipe only by operating the on-off valve provided therein, and a device such as a compressor is required. Can be injected into the sewage pumping line without performing
[0022]
Further, since air injection uses a water pressure difference and does not use any power for air injection, no maintenance or the like is required.
Therefore, air injection can be performed even in a sewage pressure pipe of a manhole pump, and generation of hydrogen sulfide can be effectively prevented.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an embodiment of an apparatus for performing the method of the present invention.
FIG. 2 is a process explanatory view of the method of the present invention.
FIG. 3 is a process explanatory view of the method of the present invention.
FIG. 4 is a process explanatory diagram of the method of the present invention.
FIG. 5 is a process explanatory diagram of the method of the present invention.
FIG. 6 is a cross-sectional view of another embodiment of an apparatus for performing the method of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sewage pressure feed line 1A Upright part 2 Manhole pump 3 Manhole 4 Bypass pipe 4A Lower communication part 4B Upper communication part 5A First on-off valve 5B Second on-off valve 6A Third on-off valve 6B Fourth on-off valve 7A Lower part Water level sensor 7B Upper water level sensor 8 Control device W Sewage

Claims (1)

A bypass path is provided in an upright portion of a sewage pressure feed line to which sewage is supplied from a manhole pump, and first and second on-off valves are respectively provided in a lower communication portion and an upper communication portion of the sewage pressure feed line in the bypass route. On the other hand, third and fourth on-off valves that open into the manhole at the upper and lower ends of the bypass path are separately provided, and the sewage is not filled in the bypass path during the operation of the manhole pump when the manhole pump is not filled with sewage. Opening the first and second on-off valves, closing the third and fourth on-off valves, and closing the first and second on-off valves when the bypass path is filled with sewage, By opening the third and fourth on-off valves, the forcible injection of air into the sewage pressure-feeding line when the first and second on-off valves are opened. Air injection method.

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