JPH0537397U - Septic tank - Google Patents

Abstract

(57) [Summary] [Structure] An anaerobic filter bed tank N and a contact aeration tank E are installed in this order from the sewage inflow side, and the contact aeration tank E to the anaerobic filter bed tank N are installed.
A return path B for returning the treated water is provided in the back wall, a dam plate W is attached in the middle of the return path, and a flow rate limiting hole H for passing the returned treated water is formed in the dam plate W. [Effect] Although it is a simple improvement, the fluctuation of the flow rate due to the change of the water level in the return passage is made smaller than before, the flow rate of the return treated water is easily controlled, and a septic tank capable of stable water treatment is provided. I was able to.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a septic tank equipped with an anaerobic filter bed tank and a contact aeration tank in this order from the sewage inflow side, and a return passage for returning treated water from the contact aeration tank to the anaerobic filter bed tank.

[0002]

[Prior Art]

 Conventionally, in this type of septic tank, a V-notch is provided in the middle of the return passage in order to mitigate the fluctuation of the flow rate due to the change in the water level of the treated water returned from the contact aeration tank to the anaerobic filter bed tank. It was considered to provide the weir board which has.

[0003]

[Problems to be solved by the device]

 However, with this conventional configuration, although it is possible to alleviate the fluctuation to some extent, it is difficult to say that the fluctuation is sufficiently small, and therefore there is a drawback that stable water treatment is still difficult to perform. For example, when the amount of excess circulating water is set, the retained debris is transferred to the next tank due to the decrease in denitrification capacity due to aerobicization in the anaerobic filter bed tank, and the advected water volume to which the circulating water volume is added at the time of peak inflow. There were problems such as easy migration. Therefore, an object of the present invention is to provide a septic tank capable of performing stable water treatment by further reducing the fluctuation of the flow rate due to the change of the water level in the return passage, facilitating the flow rate control of the return treated water.

[0004]

[Means for Solving the Problems]

 To achieve this purpose, the septic tank according to the present invention is characterized in that a weir plate is attached in the middle of the return path for returning the treated water from the contact aeration tank to the anaerobic filter tank, and it is returned to the anaerobic filter tank. Since the flow restricting hole for passing the treated water is formed in the dam plate, the function and effect thereof are as follows.

[0005]

[Operation] With the structure of the present invention in which the flow restricting hole is formed in the weir plate, as long as the water level is above the flow restricting hole, the process of passing through the weir plate at any height The flux cross-sectional area of water is constant because it is the cross-sectional area of the flow restriction hole itself. Therefore, in the conventional configuration, the cross section area of the flux increases in proportion to the square of the water depth up to the lower end of the V notch as the water level rises because the V notch is formed in the dam plate. As compared with the case, the change in the flow rate due to the change in the water level can be suppressed to be smaller. By the way, in the case of the structure in which the V notch is formed on the weir plate, the flow rate changes greatly in proportion to the 2.5th power of the water depth to the lower end of the V notch, whereas the flow restricting hole is formed on the weir plate. According to the present invention, it is possible to suppress a small flow rate fluctuation proportional to the 0.5th power of the water depth up to the flow rate limiting hole.

[0006]

[Effect of the device]

 It is a simple improvement that only a flow restriction hole is formed in the weir plate without installing a new device, but the fluctuation of the flow rate due to the change of the water level in the return passage is made smaller than before and the return is performed. We were able to provide a septic tank that facilitates the management of the flow rate of treated water and enables stable water treatment by the circulating anaerobic / aerobic filter bed method.

[0007]

【Example】

 Hereinafter, the configuration of the embodiment of the present application will be described with reference to the drawings. As shown in FIG. 1, this septic tank 1 includes an anaerobic filter bed tank N composed of an anaerobic filter bed tank first chamber N1 and an anaerobic filter bed tank second chamber N2, a contact aeration tank E, and a sedimentation apparatus from the upstream side. The tank P is provided in this order. Hereinafter, each tank N, E, P will be described in more detail. The anaerobic filter bed tank first chamber N1 removes coarse suspended matter in the treated water flowing from the inflow port 2, and performs anaerobic decomposition treatment in the same manner as the anaerobic filter bed tank second chamber N2. Therefore, in the anaerobic filter bed first chamber N1 and the anaerobic filter bed second chamber N2, anaerobic microorganisms that anaerobically decompose organic substances in the treated water are made to live, and the biofilm thereof is fixed as First and second filter beds F1 and F2 are provided. Here, the first filter bed F1 of the first chamber N1 of the anaerobic filter bed is formed by a honeycomb tubular filter medium mesh with a coarse lattice spacing that is unlikely to be clogged, and the second filter bed of the second chamber N2 of the anaerobic filter bed tank is used. F2 is constructed more densely than the first filter bed F1 in the first chamber N1 of the anaerobic filter bed. 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 is for oxidatively decomposing organic substances, ammonia 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 organic matter is brought into good contact with the aerobic microorganisms fixed on the contact material C, and this aerobic microorganism is required. An air diffuser D for supplying air for giving oxygen is arranged in the contact aeration tank E. A manhole M is provided above the contact aeration tank E 1. Next, the settling tank P will be described. The settling tank P is provided with a disinfecting tank Q, and the wastewater from the contact aeration tank E is subjected to sedimentation and removal of its suspended suspension, and then disinfected and discharged from the discharge port 4.

The transfer pipe B, which is the return path of the septic tank 1 according to the present application, will be described below. As shown in FIG. 1, the septic tank 1 is provided with a transfer pipe B for returning the treated water containing the nitrifying solution from the contact aeration tank E to the first chamber N 1 of the anaerobic filter bed, and the contact pipe B is contacted with the transfer pipe B. An air lift pump A for pumping the treated water in the air tank E is provided. The air lift pump A has a simple structure in which a hollow pipe having a suction port for treated water and a receiving port for air for air lift is arranged vertically in the lower part. As shown in a vertical side view and a cross-sectional front view in FIG. 5, a T-shaped tube T ′ is connected to branch in the front and back, and one branch tube is connected toward the transfer tube B, and at the same time, the inside of the connecting tube is connected. A wave-prevention baffle 3 (baffle plate) is provided at the expected height of the surface of the water to suppress ripples on the surface of the treated water. The other branch pipe has a water level setting dam plate 5 at its end so that the water surface is kept at an appropriate height and excess pumped water returns to the contact aeration tank E, and an opening 6 is formed. There is. As shown in FIGS. 1 to 3, a T-shaped tube T is interposed in the middle of the transfer tube B with the air vent port 7 facing upward. In the T-shaped tube T, a weir plate W is installed in the vicinity of the center where it is easy to see from the air vent 7 at right angles to the direction of the flow of the treated return water. As shown in FIG. 3, a circular flow restricting hole H is formed in the dam W to allow the returned treated water to pass therethrough while restricting the flow rate thereof, and the water level corresponding to a predetermined flow rate is formed on the vertical center line. However, a water level setting indicator line S for confirming the water level is provided. The T-shaped tube T is provided at a position where it can be easily seen from the outside of the septic tank when the manhole M'is opened. With the above configuration, it was possible to obtain a septic tank in which the flow rate of the return-treated water from the contact aeration tank E to the anaerobic filter bed first chamber N1 can be easily controlled.

It should be noted that reference numerals are added to the claims of the utility model for convenience of comparison with the drawings, but the invention is not limited to the configuration of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a septic tank according to an embodiment of the present application.

[Fig. 2] Side view of a vertical section near the weir plate

[Fig. 3] Front view crossing the barrier plate

[Fig. 4] Side view of the vertical section near the wave prevention baffle

[Fig. 5] Front view of the vicinity of a wave prevention baffle

[Explanation of symbols]

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

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Dai Harada, 2 Takamatsu, Kosai-cho, Koga-gun, Shiga Prefecture, 1st in Kubota Shiga Plant, Inc. (72) Kazuyuki Honda, 1 2 Takamatsu, Kosai-cho, Koga-gun, Shiga Prefecture Kubota Shiga Factory Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A anaerobic filter bed tank (N) and a contact aeration tank (E) are installed in this order from the sewage inflow side, and the treated water is transferred from the contact aeration tank (E) to the anaerobic filter bed tank (N). A septic tank provided with a return passage (B) for returning the water, wherein a weir plate (W) is attached in the middle of the return passage to limit the flow rate of the return-treated water to the anaerobic filter bed tank (N). A septic tank having holes (H) formed in the barrier plate (W).