JPH11104664A - Septic tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a septic tank capable of easily adjusting the amt. of circulating water without using a distributing and metering device. SOLUTION: A septic tank is partitioned by a partition wall so that an anaerobic filter bed tank, an aerobic filter bed tank, a treated water tank or a sedimentation tank and a disinfection tank are arranged in this order from an upstream side and constituted so as to circulate a part of water in the aerobic filter bed tank and the treated water tank or the sedimentation tank to the anaerobic filter bed tank. In this case, a transfer device circulating the water in the aerobic filter bed tank and the treated water tank or the sedimentation tank to the anaerobic filter bed tank is an air lift pump system and an adjusting valve 31 for adjusting a water pumping-up amt. and the transfer pipe 21 communicating with an air lift pump 11 to transfer the pumped-up water in the tanks to the anaerobic filter bed tank are arranged to the air lift pump 11 and a standard line 22 of a circulating amt. of water is provided to the outflow opening part of the transfer pipe 21 and the air lift pump 11 is operated to transfer pumped-up circulating water to the anaerobic filter bed tank.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewage treatment tank for treating domestic wastewater and night soil, and more particularly to a device for transferring water in the tank.

[0002]

2. Description of the Related Art A conventional sewage purifying tank will be described with reference to FIG. 4. A sewage purifying tank 1 is divided by partition walls 2, 3, 4, and 5, and a first anaerobic filter tank is provided from an upstream side. A chamber 6, an anaerobic filter bed second chamber 7, an aerobic filter bed tank 8, a treatment water tank 9 (sometimes a sedimentation tank), and a disinfection tank 10 are arranged in this order. Then, in order to stabilize the quality of the treated water and remove nitrogen, the water in the treated water tank 9 is sucked up by an air lift pump 11 and circulated (returned) to the first chamber 6 of the anaerobic filter bed tank. It is to be noted that the circulation is performed in the treatment water tank 9 as shown in FIG.
The water in the tank is not limited to the aerobic filter tank 8
Alternatively, the water in the sedimentation tank may be used.

[0003] Since the amount of water circulated from the treatment water tank 9 to the first anaerobic filter bed tank 6 is extremely small (several liters / minute), a commercially available submersible pump cannot be used, and as shown in FIG. Water is pumped and circulated using an air riff pump 11 that uses air as a driving force.

As shown in FIG. 5, a distribution metering device 12 for adjusting the amount of circulating water is installed on the upper part of the air lift pump 11. The water pumping mechanism of the air lift pump 11 discharges the air 14 blown from the inner pipe 13 from the bottom thereof and raises the air 14 between the outer pipe 15 and the inner pipe 13. Suction and dispensing and weighing device 12
So that the water is pumped.

[0005] The distribution metering device 12 is formed of a triangular weir 18 for measuring circulating water 17 and a return weir 19 for adjusting the amount of circulating water. The in-tank water 16 is pumped excessively by the air lift pump 11, and only the required amount of circulating water overflows from the triangular weir 18. The adjustment of the amount of circulating water is performed by changing the height of the return weir 19, and the surplus water 20 is caused to overflow from the return weir 19 and return to the original tank that has been pumped.

[0006]

In the prior art, the purpose of excessively pumping the water 16 in the tank is to change the gap width between the outer pipe 15 and the inner pipe 13 when pumping only the required amount of water.
That is, it is necessary to adjust the pumping amount by changing the resistance. However, at a small level such as several liters / minute, the gap width becomes extremely small, so that the gap is partially closed by sludge or the like. This is to avoid the phenomenon that pumping is not possible.

[0007] Therefore, the dispensing and weighing device 1 as described above.
2 is installed in the air lift pump 11 to cope with it. However, the setting of the amount of circulating water is a very complicated operation because the setting of the height of the return weir 19 and the measurement of the circulating water 17 flowing from the triangular weir 18 using a container are performed. Further, even if the height of the return weir 19 can be finely adjusted, sludge easily adheres to the triangular weir 18 and the return weir 19, and the height of each weir changes depending on the amount of sludge attached. As a result, there is a problem that the circulating water amount is different from the initial setting, and a stable shift cannot be performed.

In view of the above-mentioned problems, the present invention eliminates the need for the conventional dispensing and measuring device 12 and makes it possible to easily adjust the flow rate of the circulating water as low as several liters / minute. It is an object of the present invention to provide a sewage septic tank incorporating the same.

[0009]

According to the present invention, as shown in FIG. 3, the inside of the tank is partitioned by partition walls 2, 3, 4, and 5, and an anaerobic filter tank, an aerobic filter tank 8, Treated water tank 9 or sedimentation tank,
In the purification tank which is arranged in the order of the disinfecting tank 10 and circulates a part of the water in the aerobic filter bed tank 8, the treatment water tank 9 or the sedimentation tank to the anaerobic filter bed tank, The transfer device that circulates the water in the treatment water tank 9 or the sedimentation tank to the anaerobic filter bed tank is an air lift pump system. Specifically, as shown in FIG. 1 and FIG. And a transfer pipe 21 that communicates with the air lift pump 11 and transfers the pumped water 16 from the tank to the anaerobic filter bed tank. It is characterized in that a reference line 22 is provided.

That is, the amount of water pumped by the air lift pump 11 is adjusted by adjusting the amount of air used as a driving force of the pump.
The measurement of the amount of circulating water to be transferred is performed by the reference line 22 provided at the outlet side opening of the transfer pipe 21, and the pumped circulating water 17 is transferred to the anaerobic filter bed tank.

The circulating water 17 is circulated to the anaerobic filter bed tank. If a plurality of anaerobic filter bed tanks are provided as shown in FIG. It is preferable to circulate to the anaerobic filter bed first chamber 6 closest to the inlet 26.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The amount of water pumped by the air lift pump 11 is determined by the immersion depth between the water surface and the lower end of the air lift pump 11,
It is determined by the pipe diameter, the head, and the amount of air, but the present invention is directed to an extremely low level of about several liters / minute of pumped water.

In view of this, an adjustment valve 31 is provided in the air pipe line to which sludge does not adhere in the pipe line of the air lift pump so that an air amount corresponding to a required pumping amount can be inserted, so that the entire amount of pumped circulating water is transferred. ing. Furthermore, the measurement of the amount of circulating water that is pumped is performed using a reference line 22 (see FIG. 2) provided at the outlet side opening of the transition pipe 21 that communicates with the air lift pump 11.

In particular, as shown in FIG. 2, by providing a plurality of reference lines 22 corresponding to the required amount of circulating water, as shown in FIG. Makes adjustment easier.

The outlet side opening of the transition pipe 21 communicating with the air lift pump 11 has a tubular shape in which the horizontal pipe diameter is shorter than the vertical pipe diameter. Appears to be easy to read.
Therefore, the outflow-side opening of the above-mentioned transition pipe 21 has a vertically long elliptical shape in a vertical cross section, but as shown in FIG. Alternatively, the lower side of the elliptical surface may be a triangular shape having the tube bottom as the vertex, or a shape similar thereto.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. In the sewage purification tank 1 shown in FIG. 3, the inside of the tank is partitioned by partition walls 2, 3, 4, and 5, and an anaerobic filter bed tank 1 is provided from the upstream side.
A chamber 6, an anaerobic filter bed second chamber 7, an aerobic filter bed tank 8, a treatment water tank 9, and a disinfection tank 10 are arranged in this order. The anaerobic filter tank first chamber 6 and the anaerobic filter tank second chamber 7 are provided with filter media 23 and 24, and the aerobic filter tank 8 is provided with a microorganism adherent 25.

The sewage 27 flowing into the first anaerobic filter tank 6 from the inlet 26 is treated through the second anaerobic filter tank 7 and the aerobic filter tank 8, and further through the treated water tank 9 to the disinfecting tank. It is sterilized at 10 and discharged from the outlet 28 as treated water 29 outside the system. Part of the water in the treatment water tank 9 is pumped by an air lift pump 11 for stabilization of treatment water quality and denitrification,
The transfer pipe 21 circulates (returns) the anaerobic filter bed tank 1 to the first chamber 6.

The air lift pump 11 and the transfer pipe 21 will be described in detail with reference to FIG. 1. Air 14 inserted into the air lift pump 11 from the blower 30 via the regulating valve 31 is discharged from the lower end of the inner pipe 13. It rises between the outer tube 15 and the inner tube 13. The propulsion force by which the air 14 rises causes the tank water 16 to be pumped, and the pumping water reaches the anaerobic filter bed tank 1 chamber 6 as the circulating water 17 from the transition pipe 21.

The measurement and adjustment of the amount of circulating water will be described in detail with reference to FIG. 2. The circulating water 17 flows out of the outlet side opening of the transition pipe 21. (See FIG. 1, FIG. 1). That is, if the relationship between the water amount and the water level height is measured in advance and the height is set as the circulating water reference line 22, the circulating water amount can be determined. Adjustment of the amount of circulating water can be set by changing the amount of air using the above-described adjusting valve 31 so that the required circulating water reference line 22 is obtained.

As shown in FIG. 2 (b), the amount of circulating water at the outflow opening (portion a) of the transition pipe 21 is cylindrical, that is, the pipe diameter in the horizontal direction is shorter than the pipe diameter in the vertical direction. It has a vertically long elliptical shape in the cross section in the direction, and a change in the amount of water appears largely as a change in water level, so that measurement and adjustment can be easily performed. Further, as shown in FIG. 2 (c), if the lower side of the elliptical surface is a triangular shape having the tube bottom as the apex, measurement and adjustment can be performed with higher accuracy.

[0021]

As described above, according to the present invention,
Conventionally, it was difficult to adjust the amount of circulating water due to the use of a dispensing and metering device.However, by providing a regulating valve for changing the amount of air and a circulating water guide line at the outlet side opening of the transition pipe,
The flow rate can be easily adjusted without using a distributing and weighing device. In addition, the flow rate can be adjusted more accurately by using a shape of the outlet side opening of the transition pipe whose horizontal diameter is shorter than vertical diameter.

[Brief description of the drawings]

FIG. 1 shows a perspective view of an air lift pump and a transition pipe which are main parts of the present invention.

FIGS. 2A and 2B are diagrams showing an outlet side opening of a transition pipe used in the present invention, wherein FIG. 2A is an enlarged view of a portion a in FIG. 1 and FIG.
(C) shows an AA sectional view of (a).

FIG. 3 is a sewage purification tank showing an embodiment of the present invention,
(A) shows a horizontal cross-sectional view, and (b) shows A in (a).
FIG.

FIG. 4 is a sewage purification tank showing a conventional example, in which (a) shows a horizontal sectional view, and (b) shows an AA sectional view of (a).

FIG. 5 is a perspective view of a conventional dispensing and weighing device.

[Explanation of symbols]

1. Sewage septic tank 2. Partition wall 3. Partition wall 4. Partition wall 5. Partition wall 6. Anaerobic filter tank 1st room 7. 7. Anaerobic filter tank 2nd room Aerobic filter bed tank 9. Treatment water tank 10. Disinfection tank 11. Air lift pump 12. Dispensing and weighing device 1
3. Inner pipe 14. Air 15. Outer tube 16. Water in tank 1
7. Circulating water 18. Triangular weir 19. Return weir 20. Surplus water 21. Transition pipe 22. Circulating water guide line 2
3. Filter medium 24. Filter medium 25. Microbial adherent 26. Inlet 27. Sewage 2
8. Outlet 29. Treated water 30. Blower 31. tuning valve

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yuji Koizumi 1250 Shimoedori, Shimodate-shi, Ibaraki Pref.Hitachi Chemical Industry Co., Ltd.

Claims (2)

[Claims] A tank is partitioned by a partition wall, and an anaerobic filter bed tank, an aerobic filter bed tank, a treatment water tank or a sedimentation tank, and a disinfection tank are arranged in this order from the upstream side, and an aerobic filter bed tank and a treatment water tank are arranged. Alternatively, in a purification tank that circulates a part of the water in the sedimentation tank to the anaerobic filter bed tank, a transfer device that circulates the water in the aerobic filter bed tank, the treatment water tank or the sedimentation tank to the anaerobic filter bed tank is provided. An air lift pump system, comprising: an adjusting valve for adjusting the pumping amount of the air lift pump; and a transfer pipe communicating with the air lift pump and transferring the pumped water in the tank to an anaerobic filter bed tank. A sewage treatment tank characterized in that a guide line for the amount of circulating water is provided at the outlet of the pipe. 2. A transfer pipe which communicates with an air lift pump and has a guide line for the amount of circulating water at an outlet side opening, wherein a tubular pipe having a horizontal pipe diameter shorter than a vertical pipe diameter at the outlet side opening. The sewage purification tank according to claim 1, comprising: