JPH10183734A - Sewage conveying pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently make oxygen get mixed in sewage by communicating an air injection pipe with the bottom of a sewage conveying pipe, and providing a baffle plate for causing a vortex in an air supply part on the upstream side of the air supply part of the air injection pipe. SOLUTION: An air injection pipe 2 is communicated with the bottom 1B of a sewage force-feed pipe 1, and a baffle plate 3 for causing a vortex in an air supply part from the air injection pipe 2 is provided on the upstream side of the air injection pipe 2. In the case of injection air into the sewage being conveyed from the air injection pipe 2, since a vortex W is caused by the baffle plate 3 in the air supply part from the air injection pipe 2, the air bubbles are sucked in the vortex to be crushed and fined, and also gas and liquid are strongly mixed by the vortex, so that the air dissolving degree to the sewage is heightened. Even when a current is fast, satisfactory gas-liquid mixing can be done to efficiently achieve rising of the dissolved oxygen quantity in the sewage. Accordingly, enough air can be mixed in the sewage so as to efficiently supply oxygen.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewage pressure pipe.
More specifically, the present invention relates to an improvement of an air injection type sewage pipe.

[0002]

2. Description of the Related Art In a sewerage line, microorganisms in sewage may reduce sulfates to generate hydrogen sulfide, and hydrogen sulfide causes malodor and concrete corrosion.

[0003] The generation of hydrogen sulfide is generally remarkable in a pressure-feeding pipeline to which oxygen is not supplied, and in some cases, problems relating to malodor and corrosion of concrete have also become apparent. Therefore, as a measure for preventing hydrogen sulfide generation, there has been proposed an air injection system in which an air pipe is provided in a sewage pressure feed pipe and air is discharged into the sewage from a vent provided in a side wall of the air pipe (for example, Japanese Patent Application Laid-Open No. Hei 7-1995). -150612).

[0004]

However, in the case of the above-mentioned air-injection type sewage pumping pipe, if the sewage flow in the pipe is relatively slow or stopped, but if the flow is relatively fast, the sewage is discharged from the air pipe. If only natural air blowing is used, the air bubbles are merely flowed downstream together with the sewage, so that aggressive gas-liquid mixing is not achieved and eventually the bubbles are discharged to the outside from the pipe outlet.

Therefore, the amount of oxygen taken into the sewage does not correspond to the amount of air supplied, and even if the generation of hydrogen sulfide can be prevented, the efficiency is not high.
SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has been made to increase the concentration of dissolved oxygen in sewage as much as possible.

[0006]

That is, in the sewage pumping pipe of the present invention, an air injection pipe is opened at the bottom of the sewage pumping pipe, and the air supply pipe is connected to the air supply section upstream of the air supply section of the air injection pipe. A baffle plate for generating a vortex is provided.

[0007]

Next, an embodiment of the present invention will be described.
FIG. 1 is a sectional view showing an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a sewage pressure feed pipe. An air injection pipe 2 is opened at a bottom 1B of the sewage pressure feed pipe 1, and an air supply from the air injection pipe 2 is provided upstream of the air injection pipe 2. The part is provided with a baffle plate 3 for generating a vortex.

In the above description, the baffle plate 3 is only required to generate a vortex in the sewage flow. Therefore, as shown in the drawing, one end 3A is obliquely cut inside the branch pipe 1A to which the air injection pipe 2 is attached. Connect the pipe 3B to the high pipe end 3C.
May be inserted and fixed as the upstream side of the sewage pressure feed pipe 1 and this may be used as the baffle plate 3.

[0010] However, as shown in FIG.
May be joined to the pipe wall of the sewage pressure feed pipe 1, and a weir-shaped baffle plate 3 may be separately provided upstream of the pipe. The height h of the baffle plate 3 is set to １ ／ to ３ of the inner diameter d of the sewage pressure feed pipe 1. If h> 1/2, the effective diameter in the sewage feed pipe 1 is narrowed, and the flow efficiency is adversely affected. If h <１ ／, vortices cannot be formed sufficiently, and the air mixing efficiency is not significantly improved. This is because the effect cannot be obtained.

The air injection pipe 2 can be installed at a position below the water level in the sewage pressure feed pipe 1, but it is desirable to open the pipe at the pipe bottom 1B which is always in contact with the sewage. Next, the operation will be described.

When air is injected from the air injection pipe 2 into the sewage being pumped, a vortex W due to the baffle plate 3 is generated in the air supply section from the air injection pipe 2.
Bubbles are entrained in this vortex, pulverized and refined, and vigorously gas-liquid mixed by the vortex, thereby increasing the air solubility in the sewage.

Therefore, even when the flow is very fast, sufficient gas-liquid mixing is achieved, and the amount of dissolved oxygen in the sewage is efficiently increased.

[0014]

As described above, according to the present invention, when air is injected into the sewage pressure feed pipe, a vortex is generated in the sewage flow by the baffle plate, and bubbles are supplied into the vortex flow. The gas is made finer by the vortex and the gas and liquid are mixed.

Therefore, even if there is a flow, sufficient air can be mixed into the sewage, and efficient oxygen supply can be achieved. When the sewage flow is slow or stopped, the air injection state is the same as before, so that the amount of dissolved oxygen in the sewage can be significantly increased as a whole, and the effect of preventing the generation of hydrogen sulfide is excellent. It is.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Sewage pressure feed pipe 1A ... Branch pipe 2 ... Air injection pipe 3 ... Baffle plate 3A ... One end 3B ... Pipe 3C ... High pipe end W ... Eddy flow

Claims (1)

[Claims] An air injection pipe is opened at the bottom of a sewage pressure feed pipe, and a baffle plate for generating a vortex in the air supply section is provided upstream of the air supply section of the air injection pipe. And sewage pressure pipe.