JP2575571Y2 - Septic tank - Google Patents

Description

[Detailed description of the invention]

[0001]

In the present invention, a contact aeration tank is provided downstream of an anaerobic filter bed tank, and a return path for returning the liquid in the tank from the contact aeration tank to the anaerobic filter bed tank is provided by an air lift. The present invention relates to a purification tank comprising a pipe and a return pipe which is connected to the upper part of the air lift pipe and guides the liquid in the tank to the anaerobic filter bed tank.

[0002]

2. Description of the Related Art Conventionally, in the above-mentioned septic tank, a gas-liquid separation forming a large space above the return pipe at the upper end of the air lift pipe in order to remove bubbles from the pumped water raised by the air lift action. There was only a part.

[0003]

However, in the above configuration, the water level in the air lift tube fluctuates due to the rise of bubbles blown into the air lift tube, and when the water level fluctuates, the water pressure at the air supply pipe connection position is reduced. Fluid fluctuates due to the influence, and a vicious circulation occurs in which air bubbles are blown out into the air lift pipe unevenly, so that the liquid to be treated returned to the anaerobic filter bed tank and the liquid returned from the return pipe to the contact aeration tank by overflow. Fluctuations in the flow rate of the processing liquid and the like are large, and the flow rate of the liquid to be processed returned to the anaerobic filter bed tank is not easily stabilized.

However, when the flow rate of the liquid to be treated returned to the anaerobic filter bed tank decreases, the amount of nitrifying liquid and the amount of separated sludge returned to the anaerobic filter bed tank decrease. While the amount becomes insufficient, the concentration of the separated sludge in the contact aeration tank tends to increase. Further, if the flow rate of the liquid to be treated returned to the anaerobic filter bed tank is too large, the amount of oxygen returned to the anaerobic filter bed tank also increases, and the anaerobic treatment and the denitrification treatment itself do not easily proceed. That is, there is a disadvantage that the above-mentioned stable biological treatment is difficult to perform.

Further, in order to suppress the blowing of air bubbles in the air lift pipe to stabilize the water level and to perform effective gas-liquid separation for stabilizing the amount of water to be returned and the amount of oxygen contained therein, A gas-liquid separation chamber is required, and in some cases, the septic tank main body must be enlarged, and in a situation where overall treatment in a limited space is necessary, providing the large gas-liquid separation chamber occupies the inside of the septic tank. There was also a drawback that the space became large and hindered the inspection of the inside of the tank.

Therefore, in view of the above-mentioned drawbacks, the object of the present invention is to stabilize the flow rate of the liquid to be treated returned to the anaerobic filter bed tank through the return path, and to achieve stable biological treatment with a relatively small size. An object of the present invention is to provide a septic tank that can be performed in a space.

[0007]

SUMMARY OF THE INVENTION To achieve this object, the present invention is characterized in that an abnormal condition that rapidly rises with air bubbles at the upper part of the air lift pipe in the return path and above the steady water level in the return pipe. The abnormal pumping mitigation body that receives the pumping is provided so as to be able to move up and down freely upon receiving the abnormal pumping , and the operation and effect obtained therefrom are as follows.

[0008]

[Function] In other words, as the air is supplied from the lower part of the air lift pipe, the liquid to be treated is pumped up in the air lift pipe together with the air bubbles, and the inside of the air lift pipe is processed from the opening at the lower end toward the arrangement part of the abnormal pump relief body. The liquid flows. At this time, the liquid to be treated, which has been pumped to a higher level than the steady water level by the blowing of non-uniform bubbles, collides with the abnormal pumping mitigation body. At this time, the abnormal pumping mitigation body is pushed up by the liquid to be treated, the pumping power is absorbed, and the bubbles in the liquid to be treated are easily separated from the liquid to be treated by collision with the abnormal pumping mitigation body. The gas-liquid separation chamber becomes unnecessary.

Further, since abnormal pumping can be suppressed with a simple device, the space inside the septic tank can be small.

[0010]

[Effects of the Invention] Therefore, even if the liquid to be treated rises sharply together with bubbles, the abnormal pumping suppressor suppresses the abnormal pumping, and the liquid to be treated returned to the anaerobic filter bed tank undergoes gas-liquid separation. Therefore, the amount of the liquid to be treated returned to the anaerobic filter tank is stabilized, and the amount of oxygen supplied to the anaerobic filter tank is also stabilized, so that the anaerobic filter tank can be prevented from becoming excessive in oxygen, Good sewage treatment can be maintained.

Further, since the space occupied by the return path provided with the abnormal pumping mitigation body occupies a small space, the entire septic tank can be formed compactly without obstructing the inspection of the inside of the septic tank.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, from the upstream side, the first anaerobic filter tank
An anaerobic filter tank N consisting of a chamber N1 and an anaerobic filter tank 2nd chamber N2, a contact aeration tank E, a settling tank P, and a disinfecting layer Q are provided so that the liquid to be treated flows in this order by natural advection. It is composed.

In the anaerobic filter bed tank N, an anaerobic microorganism for anaerobically decomposing organic substances in the liquid to be treated and denitrifying nitrate nitrogen grows, and a filter bed F for fixing the biofilm.
1 and F2, the first anaerobic filter tank N1 and the second anaerobic filter tank
Each is provided separately in the chamber N2.

The contact aeration tank E is provided with a contact material C for fixing aerobic microorganisms for decomposing the remaining organic substances in the liquid to be treated and nitrifying ammoniacal nitrogen. A diffuser tube D for producing a circulating flow of air, bringing the aerobic microorganisms fixed on the contact material C into good contact with the water to be treated containing organic matter, and supplying air for supplying oxygen required to the aerobic microorganisms D Is provided.

Further, in order to prevent clogging due to excessive attachment of a biofilm or the like to the contact material C, air bubbles are released and collided with the contact material C, and excess biofilm or the like is converted into exfoliated sludge. A backwash pipe R for peeling is provided below the contact material C, and the suspended sludge in the contact aeration tank E is increased by the peeled sludge, so that the BOD is not excessively increased, and the nitrification liquid is denitrified. The return path A for returning the separated sludge and the water to be treated containing the nitrification liquid to the first anaerobic filter bed tank N1 is connected to the air lift pipe Aa and the upper part of the air lift pipe Aa to perform the treatment. A return pipe A for guiding the liquid to the anaerobic filter bed tank N
and p.

As shown in FIG. 1 and FIG.
Raises the air lift pipe Aa vertically from the lower part of the contact aeration tank E, forms an opening Ai at the lower end of the air lift pipe Aa for taking in the liquid to be treated, and supplies air near the lower end. An air supply pipe S for supplying air from the device is connected and connected to the air supply pipe S, and a relaxing body accommodating portion A1 is formed above the air lift pipe Aa.
The return liquid rectification section A2 is also formed, and the return liquid rectification section A
2 is communicatively connected to the relaxing body accommodating portion A1.

A cover 3 having an air hole 2 formed in the upper part thereof is provided in the buffer housing A1, and the cover 3 is provided with a buffer 1 for suppressing abnormal pumping.

As shown in FIG. 3, the relaxing body 1 has a rod-shaped support 4 attached to the lid 3 and a movable plate 5
Is inserted and supported. The support 4 has first and second retaining portions 4a and 4b at both ends thereof. The upper first retaining portion 4a is fixed to the lid portion 3 and the lower second retaining portion 4a. 4b is located near the steady water level La, and moves the movable plate 5 during the normal operation to the steady water level La.
When the movable plate 5 is pushed upward to Lb under abnormal pumping due to the pumping force of the liquid to be treated at the time of abnormal pumping, the movable plate slides in the vertical direction to reduce the pumping power, thereby ensuring the pumping force. It has a structure that can suppress abnormal pumping.

A cutout 6 for returning excess water to the contact aeration tank E is formed in the upper part of the return liquid straightening section A2, and only the liquid to be treated having a small amount of bubbles is formed upstream of the cutout 6. And a baffle plate 7 for reducing the fluctuation of the liquid to be transferred is provided near the cutout 6.

The baffle plates 7 and 8 have openings at the lower part of the liquid layer portion, and even if there is a large ripple in the relaxing body housing section A1, a static current flows from the relaxing body housing section A1 to the return pipe Ap.
It is configured to flow to.

The treated liquid which has been treated in the contact aeration tank E is transferred from the bottom of the contact aeration tank to the settling tank P, and the supernatant of the settling tank P overflows and is guided to the disinfection tank Q, Here, the respective tanks are formed so that they are disinfected by contact with the solid disinfectant and then discharged to the outside from the discharge port Z.

With the above configuration, the flow rate of the liquid to be returned to the anaerobic filter bed tank N1 can be easily adjusted, the flow rate of the liquid to be treated and the oxygen content can be stabilized, and stable biological treatment can be achieved only by providing a small return path. You can do it.

Another Embodiment Another embodiment will be described below. In this embodiment, the anaerobic filter bed tank N is divided into two tanks.
It does not need to be divided into tanks, and may be adopted for one tank.

The structure of the relaxing body 1 does not necessarily have to be the above-described structure in which the movable plate 5 is hung on the support member 4. For example, the relaxing body 1 is slightly raised above the steady water level La in the relaxing body accommodating portion A1. It is also possible to attach the movable plate 5 freely to the inner wall of the relaxing body accommodating portion A1. Moreover, it is also possible to substitute a floating body for the movable plate 5.

The shape of the baffles 7 and 8 is not limited as long as they have the same function. In the present embodiment, the opening is formed at the lower part of the liquid layer portion. However, a stitch-shaped defoaming device may be provided. Further, the baffle plates 7 and 8 are not necessarily required. However, when the baffle plates 7 and 8 are provided, the flow rate of the liquid to be treated is further stabilized, and the amount of oxygen returned to the anaerobic filter bed tank N is increased. Therefore, the biological treatment can be performed more stably.

Incidentally, in the claims of the utility model registration, reference numerals are written for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a septic tank according to the present invention.

FIG. 2 is a longitudinal sectional view of a main part of a return path.

[Explanation of symbols]

 N Anaerobic filter bed tank E Contact aeration tank A Return path Aa Air lift pipe Ap Return pipe La Steady water level 1 Moderator

──────────────────────────────────────────────────続 き Continuing on the front page (72) Kazuyuki Honda 1 at 2 Takamatsu, Kosai-cho, Koga-gun, Shiga Prefecture Inside the Kubota Shiga Plant (72) Katsumi Hamada 2nd Takamatsu, Kosai-cho, Koga-gun, Shiga 1 Kubota Corporation Shiga Plant (56) References JP-U 4-78993 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) C02F 3/00

Claims (1)

(57) [Scope of request for utility model registration] 1. A contact aeration tank (E) is provided downstream of an anaerobic filter tank (N), and a liquid in the tank is returned from the contact aeration tank (E) to the anaerobic filter tank (N). And a return pipe (Ap) communicating with the air lift pipe (Aa) and the upper part of the air lift pipe (Aa) to guide the liquid in the tank to the anaerobic filter bed tank (N). A septic tank which rises above the air lift pipe (Aa) in the return path (A) and rises above the steady water level (La) in the return pipe (Ap) with bubbles. abnormal pumping relaxation member for receiving the abnormal pumping the (1), on receiving the abnormality pumping
Oh Ru septic tank provided freely under conjunction.