JP2565652Y2 - Septic tank - Google Patents

Description

[Detailed description of the invention]

[0001]

In the present invention, an anaerobic filter tank and a contact aeration tank are provided in this order from the sewage inflow side, and a return path for returning treated water from the contact aeration tank to the anaerobic filter tank is provided. It relates to a septic tank provided.

[0002]

2. Description of the Related Art Conventionally, in a septic tank of this type, the middle of the return path is used to reduce fluctuations in the flow rate caused by a change in the level of treated water returned from the contact aeration tank to the anaerobic filter bed tank. It has been considered to provide a weir plate having a V notch.

[0003]

However, in the conventional structure, although the above-mentioned fluctuation can be alleviated to some extent, it is difficult to say that the fluctuation is sufficiently small, and therefore, there is a disadvantage that it is still difficult to perform a stable water treatment. For example, if the amount of excess circulating water is set, the denitrification capacity decreases due to aerobicization in the anaerobic filter bed tank, and at the time of peak inflow, the suspended suspended matter is transferred to the next tank due to the added circulating water amount. There was a problem that it was easy to do. Therefore, an object of the present invention is to provide a purification tank capable of reducing the fluctuation of the flow rate due to the change of the water level in the return path, facilitating the flow rate control of the return treated water, and performing stable water treatment.

[0004]

An anaerobic filter tank and a contact aeration tank are provided in this order from the sewage inflow side, and a return path for returning treated water from the contact aeration tank to the anaerobic filter tank is provided. In a certain septic tank, a wave preventing bag is provided in the middle of the return path.
Mounting a full and weir plate, the weir plate, the anaerobic filter bed flow restricting hole for passing the return process water to the tank, the flow
The upper end of the quantity restriction hole is higher than the steady water level on the upstream side of the weir plate.
Is also provided so as to be at a low position, and its operation and effect are as follows.

[0005]

[Function] First, a wave prevention baffle is provided in the middle of the return path.
If present, the anti-wave baffle flows into the return path
Even if the water level fluctuates due to the flow of the return treated water,
The fluctuation of the water level is transmitted to the downstream side of the wave prevention baffle.
Hard to do. Also, with the configuration of the present invention in which the flow restricting hole is formed in the weir plate, the treated water passing through the weir plate at any height as long as the water level is above the flow restricting hole. Is the same as the cross-sectional area of the flow restricting hole. Therefore, the water level on the upstream side of the weir plate
Of the treated water passing through the weir plate even if
Is kept almost constant, and the cross-sectional area of the flux increases in proportion to the square of the water depth to the bottom of the V-notch as the water level rises because the V-notch is formed in the weir plate Thus, the change in the flow rate due to the change in the water level can be suppressed smaller than in the conventional configuration. Because of that,
Water level fluctuation on the upstream side is prevented by the wave prevention baffle
And to minimize fluctuations in the amount of water passing through the weir plate.
Can be synergistically returned from the return path
It was possible to stabilize the amount of treated water to be processed. By the way, in the case of the configuration in which the V notch is formed in the weir plate, the flow rate restriction hole is formed in the weir plate in comparison with the fact that the flow rate largely fluctuates in proportion to the 2.5th power of the water depth to the lower end of the V notch. In the case of the present invention, it is possible to suppress a small flow rate fluctuation in proportion to the 0.5 power of the water depth to the flow rate limiting hole.

[0006]

[Effects of the Invention] In spite of a simple improvement in which a flow restricting hole is formed in a weir plate without providing a new device, fluctuations in the flow rate due to a change in the water level in the return path are further improved than before. Make it easier to control the flow rate of return water,
It was possible to provide a septic tank capable of performing stable water treatment by a circulating anaerobic / aerobic filter bed method.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of an embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the septic tank 1 includes, from the upstream side, an anaerobic filter tank N composed of an anaerobic filter tank first chamber N1 and an anaerobic filter tank second chamber N2, a contact aeration tank E, and a sedimentation tank. P
Are provided in this order. Hereinafter, each tank N,
E and P will be described in more detail. Anaerobic filter bed tank 1
The chamber N1 removes large suspended matters in the treatment water flowing from the inflow port 2 and performs anaerobic decomposition treatment in the same manner as the anaerobic filter bed second chamber N2. Therefore, this anaerobic filter tank 1st chamber N
First and second filter beds F1 and F2 are provided in the first and second anaerobic filter bed tanks N2 in order to inhabit anaerobic microorganisms that anaerobically decompose organic substances in the treated water and to fix the biofilm as the biofilm. Have been. Here, the first filter bed F1 of the first anaerobic filter bed tank N1 is formed of a honeycomb tube-shaped filter medium mesh with a coarse lattice spacing that is difficult to clog, and the second anaerobic filter bed tank N2.
Is the first filter bed F1 of the first chamber N1 of the anaerobic filter tank.
It is more densely structured. A manhole M ′ is provided above the anaerobic filter bed tank N. Next, the contact aeration tank E will be described. The contact aeration tank E oxidizes and decomposes organic matter, ammoniacal nitrogen and the like in the treated water, and is provided with a contact material C for fixing aerobic microorganisms for this purpose. Further, a circulating flow of the treated water is generated in the contact aeration tank E, so that the treated water containing the organic matter is brought into good contact with the aerobic microorganisms fixed on the contact material C, and oxygen required for the aerobic microorganisms is removed. An air diffuser D for supplying air to be supplied is provided in the contact aeration tank E. A manhole M is provided above the contact aeration tank E. Next, the sedimentation tank P will be described. This settling tank P has a disinfecting tank Q
The suspended suspension is settled and removed from the wastewater from the contact aeration tank E, then disinfected and discharged from the discharge port 4.

Hereinafter, the transfer pipe B which is a return path of the septic tank 1 according to the present invention will be described. As shown in FIG. 1, this septic tank 1 includes a contact aeration tank E and an anaerobic filter tank first chamber N1.
Is provided with a transfer pipe B for returning treated water containing a nitrifying solution, and an air lift pump A for pumping up the treated water in the contact aeration tank E to the transfer pipe B. The air lift pump A has a simple structure in which a hollow pipe provided with a suction port for treated water and a receiving port for air for air lift is provided vertically at a lower portion, and the upper end thereof is shown in FIGS. As shown in the longitudinal side view and the cross-sectional front view, a T-shaped pipe T 'is connected to branch forward and backward, and one branch pipe is connected toward the transfer pipe B, and a connection portion of the pipe is expected to be in the pipe. A wave preventing baffle 3 (baffle plate) for suppressing waving on the surface of the treated water is provided at a height near the water surface. The other branch pipe is provided with a water level setting dam plate 5 at its end to form an opening 6 so that the water surface is kept at an appropriate height and excess pumping water returns to the contact aeration tank E. is there. In the middle of the transfer pipe B, FIG.
As shown in FIG. 3, a T-tube T is interposed with the air vent 7 facing upward. In the T-shaped pipe T, a weir plate W is mounted in the vicinity of the center which is easy to see from the air vent 7 and perpendicular to the flow direction of the return treated water. In this weir plate W, as shown in FIG. 3, a circular flow rate limiting hole H through which return treated water passes while limiting its flow rate is formed on a vertical center line, and a water level corresponding to a predetermined flow rate is formed. However, a water level setting instruction line S for confirming the water level is provided. The T-shaped tube T is provided at a position where the manhole M 'can be easily viewed from the outside of the septic tank when the manhole M' is opened.
With the above configuration, the contact aeration tank E to the anaerobic filter bed tank 1
It was possible to obtain a septic tank in which the flow rate of the treated water returned to the chamber N1 was easily controlled.

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 vertical sectional side view of a septic tank according to an embodiment of the present invention.

FIG. 2 is a side view of a longitudinal section near a weir plate.

FIG. 3 is a cross-sectional front view near a weir plate.

FIG. 4 is a longitudinal side view of the vicinity of a wave prevention baffle.

FIG. 5 is a cross-sectional front view of the vicinity of a wave prevention baffle.

[Explanation of symbols]

 N Anaerobic filter bed tank E Contact aeration tank B Return path W Weir plate H Flow restriction hole

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Daisuke Harada 2 at Takamatsu, Kosai-cho, Koga-gun, Shiga Prefecture Inside the Kubota Shiga Plant (72) Inventor Kazuyuki Honda, Takamatsu, Kosai-cho, Koga-gun, Shiga Prefecture 1 Kubota Corporation Shiga Plant (56) References Japanese Patent Laid-Open No. 2-227991 (JP, A)

Claims (1)

(57) [Scope of request for utility model registration] 1. An anaerobic filter bed tank (N) and a contact aeration tank (E) are provided in this order from the sewage inflow side, and treated water is supplied from the contact aeration tank (E) to the anaerobic filter bed tank (N). A septic tank provided with a return path (B) for returning water, wherein a wave prevention baffle (3) and a weir plate (W) are attached in the middle of the return path, and the anaerobic filter is provided on the weir plate (W). A flow restricting hole (H) through which the water to be returned to the floor tank (N) passes is provided, and an upper end of the flow restricting hole (H) is provided with the dam plate.
(W) is set to be lower than the steady water level on the upstream side.
A septic tank that has been turned off.