JPH0647107B2 - Flow control device for sewage treatment tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a flow control device for a sewage treatment tank, which is suitable for use in a relatively small-scale private house septic tank or the like.

[Prior art and problems]

Conventionally, septic tanks for exclusive use of houses are settling separation tanks that perform pretreatment (first treatment tank section), biological oxidation tanks that perform this treatment (second treatment tank section), further sedimentation tanks (third treatment tank section), and disinfection tanks. It had a total of four tanks (fourth treatment tank section), and by supplying human waste and gray water (dirty water) discharged from the house to each tank in sequence, it was purified and discharged to rivers. The sedimentation separation tank separates sediments and suspended solids from wastewater, and sends the treated water from which they have been removed to the next-stage biological oxidation tank. It has a function of storing pollutants (at least 5 hours or more, depending on the treatment method and ambient temperature) and decomposing pollutants (organic substances) by microorganisms.

By the way, the discharge time of sewage in a house is intermittent, and as is clear from the bar graph in FIG. 9, the discharge amounts of sewage a, b, c ... Fluctuate greatly with time.
By the way, in the time zone from 7:00 am to 10:00 am, about 40 to 45% of the total amount of emissions per day is emitted.

For this reason, the water increases temporarily during such a time period, and in particular, the biological oxidation tank is sent to the next settling tank (third processing tank section) without sufficient treatment time, and the purification function deteriorates significantly. There was a problem that it would end up.

In order to solve this problem, the capacity of the septic tank should be increased, but in the case of a dedicated house, the enlargement of the septic tank cannot be adopted because the installation location is limited.

An object of the present invention is to provide a flow rate adjusting device for a wastewater treatment tank, which solves the problems existing in the conventional art.

[Means for Solving the Problems]

The sewage treatment tank flow rate adjusting device 1 according to the present invention is a sewage treatment tank A that treats sewage via at least a first treatment tank portion 2 and a second treatment tank portion 3 which are arranged in a horizontal direction. 2 and the second treatment tank portion 3 between the adjusting tank portion 4 whose depth is set to half or less of the depth of the wastewater treatment tank A and the treated water W of the first treatment tank portion 2 up to a certain height. A suction pipe in which the upper end is connected to the bottom surface of the adjusting tank 4 and the lower end is extended to the vicinity of the lower end of the wastewater treatment tank A, and the water supply pipe 14 that causes the treated water W to flow out to the adjusting tank unit 4 when rising. A pipe 16 and a pumping pipe 17 whose lower portion communicates with the lower portion of the suction pipe 16 and which supplies the treated water W flowing from the suction pipe 16 to the second treatment tank portion 3 are provided, and an air jet is provided at the lower end of the pumping pipe 17. It is characterized in that the air lift pump 5 facing the outlet 21 is provided.

[Action]

According to the sewage treatment tank flow rate adjusting device 1 of the present invention, if the treated water W in the first treatment tank unit 2 rises to a certain height,
The overflowed treated water W flows out through the water supply pipe 14. Then, the treated water W that has flowed out flows into the adjustment tank unit 4 without flowing into the second processing tank unit 3.

Further, the treated water W that has flowed into the adjustment tank unit 4 flows into the pumping pipe 17 through the suction pipe 16 and is quantitatively transferred to the second processing tank unit 3 by the action of the air lift pump 5. in this case,
The adjusting tank portion 4 is configured to have a relatively small capacity, and the bottom portion of the adjusting tank portion 4 and the pumping pipe 17 of the air lift pump 5 are connected via the suction pipe 16 having a small diameter. The water W does not collect in the adjusting tank unit 4 and passes through as it is to the second processing tank unit 3.

On the other hand, the discharge amount of sewage increases temporarily and the first treatment tank unit 2
When the amount of the treated water W flowing out from the tank increases, a predetermined increase amount is temporarily stored in the adjusting tank unit 4, so that the temporary increase of the treated water W in the second treating tank unit 3 is buffered. To be done.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

First, in order to clarify the present invention, an outline of a wastewater treatment tank will be described with reference to FIG.

The sewage treatment tank A illustrated is a septic tank for exclusive use, and is buried in the ground E near the house H. The sewage treatment tank A includes a first treatment tank section (precipitation separation tank) 2, a second treatment tank section (biological oxidation tank) 3, a third treatment tank section (precipitation tank) 11, a fourth treatment tank section (disinfection tank) 12 And the flow rate adjusting device 1 is installed between the first processing tank section 2 and the second processing tank section 3 according to the present invention. Therefore, the sewage discharged from the house H flows into the first processing tank section 2 and is sent to the second processing tank section 3 via the flow rate adjusting device 1, and the third and fourth processing tank sections 11 and 12 are also discharged. It is released to rivers and the like.

Next, a specific configuration of the flow rate adjusting device 1 will be described with reference to FIG.

First, between the first processing tank section 2 and the second processing tank section 3,
An adjusting tank portion 4 having a relatively small volume is installed on the upper side thereof. Further, the adjusting tank section 4 and the first processing tank section 2 are connected by a water supply pipe 14. The water supply pipe 14 is formed in a horizontal T shape, and the vertical pipe portion 14p is arranged in the first treatment tank portion 2, and the inflow port 14q at the lower end is arranged at a substantially intermediate position in the vertical direction of the treatment tank portion 2.

On the other hand, the bottom part of the adjusting tank part 4 and the upper part of the second processing tank part 3 are connected via an air lift pump 5. Air lift pump 5
Is provided with a vertical suction pipe 16 and a pumping pipe 17, and the vicinity of the lower ends of the suction pipe 16 and the pumping pipe 17 are connected by a connecting pipe 18 inclined with the pumping pipe side slightly upward to form an N type. Then, the upper end opening of the suction pipe 16 is connected to the adjustment tank part 4, and the upper end opening of the pumping pipe 17 is exposed to the inside of the second processing tank part 3. Further, an air diffuser pipe 22 is arranged inside the pumping pipe 17, and an air ejection port 21 provided at the tip thereof is located near the lower end of the pumping pipe 17. On the other hand, the other end of the air diffuser 22 is connected to an air pump 24 via an opening / closing valve 23. The amount of air supplied by the air pump 24 can be adjusted. Note that reference numeral 25 is a bypass pipe that allows the treated water W overflowing in the adjustment tank unit 4 to flow into the second processing tank unit 3.

Next, the function of the flow rate adjusting device 1 according to the present invention will be described.

First, when the air pump 24 is operated, air is ejected from the air ejection port 21 and bubbles rise along the pumping pipe 17.

Now, if sewage is discharged from the house, it will be stored in the first treatment tank unit 2, and if sewage rises to a certain height, sewage from which suspended solids and sediments have been separated, that is, treated water W will be sent to the water pipe. It flows through 14 into the adjustment tank part 4.

When the treated water W is accumulated in the suction pipe 16 and the pumping pipe 17, the pumping action of the air lift pump 5, that is, the pumping pipe 17
The apparent specific gravity of the treated water in the pipe 17 decreases due to the bubbles ejected into the pipe 17, and a portion corresponding to the original difference in the specific gravity of the treated water is pumped and sent to the second treatment tank section 3. The treated water W sent to the second treatment tank unit 3 is quantitatively transferred,
It is determined by the capacity of the air lift pump 5 and the like. As a result, if the amount of water flowing from the first treatment tank unit 2 into the adjusting tank unit 4 is larger than the amount of water sent from the air lift pump 5, the increased amount will be stored in the adjusting tank unit 4. The amount of the treated water W transferred by the air lift pump 5 sharply decreases when the treated water W in the adjusting tank unit 4 disappears, and the pumping stops when the amount of the treated water W drops to a predetermined level in the pumping pipe 17.

Therefore, as shown in FIG.
If b, c, ... Are larger than the amount S of water quantitatively transferred from the air lift pump 5 to the second treatment tank portion 3, the increased amount M shown by the diagonal lines in the figure is stored in the adjustment tank portion 4 and the second treatment is performed. Tank part 3
The amount of water flowing into is adjusted so that it is always constant.

2 to 7 show another embodiment.

FIG. 2 shows a flow rate adjusting device 1a in which the entire space between the first processing tank section 2 and the second processing tank section 3 is configured as an adjusting tank section 4a. In this example, the water pipe 14 connected to the first treatment tank unit 2
The outlet 14r in the adjusting tank portion 4a of a is the adjusting tank portion 4
It is placed near the bottom of a so that sewage does not decay due to retention. Further, the air lift pump 5a is arranged inside the adjusting tank portion 4a, and the upper end opening of the suction pipe 16a is arranged near the upper portion of the adjusting tank portion 4a. Further, the lower end of the air lift pump 5a is formed in a U shape. The overall function is the first
It is the same as the flow rate adjusting device 1 shown in the figure.

Also, FIGS. 3 and 4 show a modified embodiment of the air lift pump. Both have different shapes.
The air lift pump 5b shown in the drawing has an H shape, and the air lift pump 5c shown in FIG. 4 has a Y shape. The shape of the air lift pump is not limited to these examples, and can be arbitrarily changed within a range that does not impair the function. In this case, in any of the air lift pumps 5, 5a, 5b, and 5c, air bubbles do not blow up into the suction pipes 16 and 16a.
It is necessary to consider that the fine solid matter deposited on the bottoms of 6, 16a can be easily removed.

Furthermore, FIG. 5 and FIG. 6 show an air lift pump 5s according to another embodiment. The pump 5s uses a suction pipe 16s having a relatively large cross-sectional area, and a pumping pipe 17s is provided inside the suction pipe 16s. In this case, suction pipe 1
The reason why the cross-sectional area of 6s is large is to facilitate the removal of the deposits deposited on the bottom of the tube. Even if it is carried out in such a form, basically the same effect as the embodiment shown in FIG. 1 is obtained. In FIGS. 5 and 6, the same parts as those in FIG. 1 are designated by the same reference numerals.

On the other hand, FIG. 7 shows an embodiment in which a flow rate fine adjustment unit 30 is provided. In this embodiment, two machines, that is, an original flow rate adjusting device serving as a master machine is arranged in the first stage, and a flow rate fine-adjusting section 30 configured as a slave machine and having a relatively small scale is used in the second stage. The sewage sucked up from the first treatment tub 2 by the air lift pump 5 is temporarily stored in the small capacity fine adjustment tub 31 installed inside the adjustment tub 4, and the sewage in the fine adjustment tub 31 is stored in the fine adjustment tub 31. Was sent to the second processing tank section 3 by the air lift pump 32. In this case, a constant water surface that is constant from the beginning is obtained in the fine adjustment tank portion 31, and the overflowed dirty water is returned to the adjustment tank portion 4. Therefore, it is possible to finely adjust the amount of pumped water for the second treatment tank section 3. In addition, 33 is an air diffuser, 3
4 shows the suction pipe of the same form as FIG.

Although various embodiments have been described in detail above, the present invention is not limited to such embodiments.
The adjusting tank part may be provided inside the first processing tank part or the second processing tank part. Further, the amount of pumped water can be adjusted by moving up and down the diffuser pipe in the pumping pipe. In addition, the detailed configuration can be arbitrarily changed without departing from the scope of the present invention.

〔The invention's effect〕

Thus, the flow rate adjusting device for a sewage treatment tank according to the present invention is, between the first treatment tank portion and the second treatment tank portion, the adjusting tank having a depth set to half or less of the depth of the sewage treatment tank. Section and the treated water in the first treatment tank portion rises to a certain height, a water pipe for flowing the treated water to the adjustment tank portion, and the bottom end of the adjustment tank portion communicates with the upper end, and the lower end is the waste water. The suction pipe extends to near the lower end of the treatment tank, the lower portion communicates with the lower portion of the suction pipe, and there is a pumping pipe that supplies the treated water flowing from the suction pipe to the second treatment tank part. Since the air lift pump having the air ejection port facing the lower end is provided, the following remarkable effects are achieved.

Since the temporary increase in water can be stored in the adjusting tank, it is possible to solve the problem that the treatment time becomes insufficient and the purification function deteriorates when increasing water. In particular, by applying it to a septic tank for exclusive housing, etc., it is possible to maintain a stable purification function at all times.
The prevention of river pollution can be achieved reliably.

Since it is sufficient for the adjustment tank part to store only the temporarily increased amount, the adjustment tank part can be downsized, and in particular, it can be applied to a dedicated house septic tank, etc. to achieve downsizing and cost reduction, and to improve the air lift pump It enables efficient and economical use.

[Brief description of drawings]

1 is a configuration diagram of a flow rate adjusting device according to the present invention, FIG. 2 is a configuration diagram of the same flow rate adjusting device according to another embodiment of the present invention, and FIGS. 3 and 4 are air lifts in the same flow rate adjusting device. Fig. 5 is a schematic view showing a modified embodiment of the pump, Fig. 5: a configuration diagram of the same flow rate adjusting device according to another embodiment of the present invention, Fig. 6: an enlarged sectional view taken along the line AA in Fig. 3, and Fig. 7. : Configuration diagram of the same flow rate adjusting device according to another embodiment of the present invention, FIG. 8: Overall schematic configuration diagram of a sewage treatment tank equipped with the same flow rate adjusting device, FIG. 9: Time-to-sewage discharge amount relationship The graph that shows. In the drawings, 1, 1a: flow rate adjusting device, 2: first processing tank part 3: second processing tank part, 4, 4a: adjusting tank part 5, 5a, 5b, 5c, 5s: air lift pump 14: water pipe , 16: suction pipe 17: pumping pipe, 21: air jet A: wastewater treatment tank, W: treated water

Claims (1)

[Claims] 1. A sewage treatment tank (A) for treating sewage through at least a first treatment tank portion (2) and a second treatment tank portion (3) which are arranged side by side in the horizontal direction. Between the second treatment tank portion (3) and the second treatment tank portion (3), the depth of the adjustment tank portion (4) is set to half or less of the depth of the wastewater treatment tank (A), and the first treatment tank portion (2). When the treated water (W) rises to a certain height, the water supply pipe (14) for letting the treated water (W) flow out to the adjustment tank part (4) and the bottom end of the adjustment tank part (4) communicate with each other. ,
In addition, the suction pipe (16) whose lower end extends to near the lower end of the wastewater treatment tank (A), and the treated water flowing from the suction pipe (16) with the lower part communicating with the lower part of the suction pipe (16) ( W)
Having a pumping pipe (17) for supplying the water to the second treatment tank part (3), and at the lower end of the pumping pipe (17) an air jet (2)
A flow control device for a sewage treatment tank, comprising an air lift pump (5) facing 1).