JPS588392Y2 - Sewage septic tank - Google Patents

Description

[Detailed description of the invention] This invention relates to an advection port structure of a partition plate between a sedimentation separation chamber and a flash chamber in a sewage septic tank 4.

In a septic tank where sewage that has flowed into the tank body of the septic tank is subjected to sedimentation separation, aeration, and sedimentation treatment, the position of the advection port that advects the supernatant liquid from the sedimentation separation chamber to the aeration chamber is as shown in Figure 1. There are known devices that are configured in the position , those that are configured in the ■-mouth position, and those that are configured in the ■-C position, etc.

That is, in the configuration of (1)-(a), since the partition plate 8 is formed with an advection flow above the water surface, the sewage flows from the sedimentation separation chamber 2 to the aeration chamber 3 as the water level rises, but the structure is such that it does not flow back. ing.

Therefore, if the difference in water level between the sewage scale discharge is large, the water pressure on the partition plate becomes large, or the sludge in the aeration chamber is not drawn out, cleaning may not be done frequently, and the sludge will be easily discharged, resulting in a good condition. In addition, the composition of the mouth cannot maintain a good water quality.
Since the advection port is formed near the water surface of the partition plate 8 mentioned above, when there is no flow rate of sewage, there is an air lift effect, etc. Due to the influence of the stirring operation in the air chamber 3, a part of the sewage in the air chamber is sedimented and separated. The sludge flows back into the chamber 2, and the sludge can be returned to the sedimentation separation chamber 2 accordingly.

However, the amount of sludge drawn out is only a small amount, but with this configuration, too much sludge is drawn out, and there is no sludge floating in the aeration chamber 3, and the value of MLSS (mixed liquid suspended solids concentration) decreases, maintaining a good treatment function. I can't.

Furthermore, in the configuration of ■-C, since an advection donkey is formed below the water surface with the first partition plate I described above, the flow between the aeration chamber 3 and the sedimentation separation chamber 2 is always maintained due to the influence of the stirring operation in the aeration chamber 3. The sewage is replaced and the sludge is drained too much.

As described above, in this sewage purification tank, the amount of sludge drawn out is not appropriate, and the concentration of activated sludge in the aeration chamber 3 cannot be maintained appropriately for a long period of time, resulting in a decrease in purification efficiency.

This idea eliminates the above-mentioned drawbacks and maintains the concentration of activated sludge in the aeration chamber at an appropriate level.The purpose of this idea is to eliminate the above-mentioned drawbacks and maintain an appropriate concentration of activated sludge in the aeration chamber. It is intended to provide a plate structure.

This invention will be explained below based on the embodiments shown in FIGS. 2 and 3.

Figures 2 and 3 show a sewage septic tank in which the interior of the tank body 1 is divided into a sedimentation separation chamber 2, an aeration chamber 3, a sedimentation chamber 4 and a disinfection chamber 5.The aeration chamber 3 and the sedimentation chamber 4 are separated by a separator 6 The sedimentation chamber 4 and the disinfection chamber 5 are divided by a disinfection tank 1, and the sedimentation separation chamber 2 and the aeration chamber 3 are divided by a partition plate 8.

The partition plate 8 is provided with a communication port 8a in the central part below the water surface, which can be freely adjusted in opening size, and has a cross-sectional co-portion projecting above the center into the sedimentation separation chamber 2gIIj to prevent scum from flowing into the sedimentation separation chamber. The first partition plate 8 has a penetrating protrusion 8b formed thereon, and the protrusion 8b protrudes from the lower end of the communication port 8a and extends to the water surface position at the upper end (slightly above the normal water level). and a second partition plate 9 having a U-shaped cross section.

The wastewater that has flowed into the inflow pipe 10 is separated from solid matter in the sedimentation separation chamber 2, and the supernatant liquid flows from the upper end of the second partition plate 9 to the communication port which is the advection port of the first partition plate 8. It is transferred to the air chamber through the port 8a.

Since the inside of the aeration chamber 3 is aerated with air from the aeration pipe 12, the air lift effect of air bubbles mixed in the wastewater and the influence of stirring cause the liquid in the aeration chamber to be dispersed little by little, backflowing to the sedimentation separation chamber and being replaced. arise.

Furthermore, when wastewater flows into the sedimentation separation chamber 2, a strong flow is generated from the sedimentation separation chamber 2 toward the aeration chamber 3, so that no clogging or the like occurs.

Therefore, since the sludge is not returned by directly utilizing agitation in the aeration chamber as in the conventional case, the optimum amount of sludge can be drawn out minute by minute.

The liquid is advected into the settling chamber 4 via the aeration chamber 3 and further below the separator 6, and the sludge is returned by gravity and returned to the aeration chamber 3 again.
After entering the disinfection chamber 5 and being disinfected, the outflow pipe 13 is discharged outside the tank body 1.
more released.

As shown in FIG. 4, the second partition plate 9 has a V-shaped notch 9a extending slightly above the water level at the upper end and downward from the water surface to separate the sedimentation separation chamber 2 and the aeration chamber 3. The amount of liquid exchange can be optimally adjusted, making it even more effective, and if an adjustable adjustment plate is pivotally mounted at the upper end of the plate to adjust the flow rate of wastewater, the above-mentioned adjustment of the communication port 8a can be achieved. Together with this, the 4N replacement amount of wastewater, that is, the MLSS (mixed liquid suspended solids concentration) in the aeration chamber 3 can be adjusted.

Alternatively, this aeration chamber may be a contact aeration chamber filled with furnace material 11 as shown by dotted lines in FIGS. 2 and 3.

As described above, according to this invention, the partition plate constituting the advection port for sewage flowing from the sedimentation separation chamber to the aeration chamber includes a first partition plate in which a communication port is formed and a partition plate that protrudes from the first partition plate. Because the second partition plate was placed extending above the water level,
A sewage septic tank that can easily adjust the concentration of suspended solids in the mixed liquid in the aeration chamber and is suitable for long-term operation can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a schematic partial sectional view of a conventional sewage septic tank, Fig. 2 is a sectional view of a main part of a septic tank showing an embodiment of this invention, and Fig. 3 is a cross section taken along line A-A in Fig. 2 showing the inside of the tank body. 4 are perspective views showing other embodiments of the partition plate. 1... Tank body, 2... Sedimentation separation chamber, 3.
...Air chamber, 4...Sedimentation chamber, 6...
...Separator, 8...First partition plate, 8a
...Communication port, 8b...Protrusion, 9...
...Second partition plate, 11...P material, 12.
・・・・・・Diffuser pipe.

Claims (1)

[Scope of utility model registration request] A sewage septic tank in which the sedimentation separation chamber and the sedimentation chamber are separated by a partition plate, and the aeration chamber and the sedimentation chamber are separated by a separator, and the partition plate has a communication port in the central part below the water surface. A sewage septic tank comprising: a first partition plate that projects from below the communication port toward the sedimentation separation chamber and has a U-shaped cross section with an upper end extending to near the water surface.