JP2771733B2 - Septic tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a sedimentation tank provided downstream of a contact aeration tank in communication with a lower part of a partition wall, and an aeration pipe for generating a circulation flow in the contact aeration tank.
The present invention relates to a septic tank provided with a return portion protruding toward the contact aeration tank at the lower end of the partition.

[0002]

2. Description of the Related Art Conventionally, in this type of septic tank, FIG.
As shown in FIG. 3, a diffuser D is provided at the bottom of the contact aeration tank E at the upstream side substantially at the center in the width direction, and the lower end of the partition wall W1 has the return portion R only at the left and right portions thereof. Was formed. More specifically, by diffusing air in the diffuser tube D, a swirling flow is generated in the contact aeration tank E at the diffuser tube D side in the width direction center at the diffuser tube D side, and descends at the partition wall W1 side, and descends at the partition wall W1 side. Is formed in the sedimentation tank P through a central portion of the lower end of the partition wall W1. The flow entering the sedimentation tank P is once divided into right and left parts, and each part is returned to the return part R and the bottom of the purification tank. And passed through the gap between them and returned to the contact aeration tank E.

[0003]

However, in such a structure, when the central flow entering the sedimentation tank is divided into right and left and returns to the contact aeration tank, the flow is weakened and the downflow The sludge tends to accumulate in the lower left and right corners of the settling tank. Therefore, when the flow rate of the raw water suddenly increases, there is a possibility that sludge accumulated in the lower left and right corners of the settling tank is discharged together with a large amount of the water to be treated. Therefore, an object of the present invention is to provide a septic tank having a structure in which sludge is hardly discharged even when a large amount of raw water suddenly flows.

[0004]

In order to achieve this object, a characteristic structure of the septic tank according to the present invention is that a sedimentation tank is provided downstream of the contact aeration tank so as to communicate below the partition wall, and the contact aeration tank is provided with the sedimentation tank. A diffuser tube for generating a circulating flow is dispersed and arranged at a distance to the left and right with respect to the direction of the flow, and at the lower end of the partition wall, at the center in the width direction, the contact aeration tank side than the left and right portions. Is provided with a greatly protruding return portion.

[0005]

When air is diffused by the diffuser tubes which are separated and arranged at right and left sides, as shown in FIG. 1, the water to be treated having a strong flow which rises on the diffuser tube D1 side and descends along the partition wall W1 on the left and right sides. A swirling flow occurs in the contact aeration tank E. And
Part of the strong flow descending along the partition W1 is
The sedimentation tank P passes under the left and right portions of the lower end of the sedimentation tank 1, and the left and right flows that have entered the sedimentation tank P are combined as blow-up flows, and a part thereof flows under the central return part R. Return to the contact aeration tank E. Since the left and right flows entering the sedimentation tank P are strong updrafts, sludge hardly accumulates in the lower left and right corners of the sedimentation tank P. Further, the above-mentioned left and right blow-up flows merge and pass under the central return portion R to return to the contact aeration tank E. Therefore, the return flow also becomes strong, and therefore, the vicinity of the central return portion R In this case, sludge hardly accumulates and is returned to the contact aeration tank E. In the contact aeration tank E, a circulating flow is also generated at the center in the width direction. The circulating flow is slower than the two swirling flows along each of the right and left side walls, and is gentle along the partition W1. The downward flow hits the upper surface of the return portion R formed at the center of the lower end of the partition wall W1, so that the weak flow that easily causes sludge to stay there is prevented from entering the settling tank side. As a result, since a large amount of sludge does not accumulate in the sedimentation tank P, it is possible to eliminate the danger that tends to occur in the conventional septic tank, in which the retained sludge is suddenly wound up and discharged with the rapid increase of the inflowing raw water. Further, since sludge does not accumulate in the lower part of the sedimentation tank P, generation of scum is suppressed, and maintenance is facilitated.

[0006]

Therefore, a relatively strong flow can be obtained in both the flow from the contact aeration tank to the sedimentation tank and the flow from the sedimentation tank to the contact aeration tank under the partition wall. Sludge hardly accumulates in the wastewater, and as a result, even when a large amount of raw water flows in, sludge is hardly discharged, and a septic tank with good treated water quality can be provided.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the septic tank according to the present invention will be described below. First, the outline of the entire septic tank will be described. As shown in FIG. 2, an anaerobic filter tank N comprising an anaerobic filter tank first chamber N1 and an anaerobic filter tank second chamber N2 from the upstream side,
The contact aeration tank E and the settling tank P are provided so that the liquid to be treated flows in this order by natural advection to form a purification tank.

[0008] The anaerobic filter bed tank N is provided with filter beds F1 and F2 for growing anaerobic microorganisms that anaerobically decompose organic substances in the water to be treated and fixing their biofilms. The contact aeration tank E is provided with a contact material C for fixing aerobic microorganisms that decompose the remaining organic substances in the water to be treated and perform a nitrification reaction of ammoniacal nitrogen. In the sedimentation tank P, the supernatant liquid overflows and is guided to the disinfection tank Q. At the inlet of the disinfecting tank Q, a medicine tube T containing a solid disinfectant is disposed, and the medicine tube T has a plurality of slit-shaped openings formed at a lower portion thereof for inflow and outflow of water to be treated.
The water to be treated, which has come into contact with the disinfectant in the cartridge T, passes under the baffle plate 4 provided in the middle of the disinfection tank Q and overflows and is discharged.

The structure of the main part from the contact aeration tank E to the sedimentation tank P, which shows the unique structure of the present invention, will be described in more detail. FIG. 1 shows the contact aeration tank E
FIG. 2 is a perspective view showing a state in which a partition wall W1 provided between the tank A and the sedimentation tank P is viewed from the contact aeration tank E side. As shown in FIGS. 1 and 2, the contact aeration tank E generates a circulating flow of the water to be treated in the tank, and the contact material C (omitted in FIG. 1).
A pair of diffuser tubes made of a plastic porous tube for supplying air that gives necessary oxygen to the aerobic microorganisms by bringing the treated water containing organic matter into good contact with the aerobic microorganisms fixed to D1 and D1 are in the anaerobic filter tank 2nd room N
Along the partition wall W2 on the two sides, they are horizontally distributed and arranged at the bottom of the tank, and these are connected to an air supply blower (not shown).

The contact aeration tank E and the settling tank P are separated from the partition W
It is provided to communicate below 1. The lower end of the partition wall W1 is connected to a horizontal plate portion 2 bent toward the contact aeration tank side via an inclined plate portion 1 protruding downward on the settling tank Q side, and the width of the purification tank in the horizontal plate portion 2 is provided. The central portion in the direction protrudes largely horizontally to the contact aeration tank E side than the left and right portions, and the protruding portion is formed in the return portion R. Settling tank P
In order to easily guide the return flow of the water to be treated toward the contact aeration tank E from above, the return portion R is provided with a guide plate portion 3 extending downward at the left and right edges thereof and formed in a U-shaped channel shape. I have. It should be noted that the horizontal plate portion 2 has only a central return portion,
The left and right horizontal plate portions 2 may be omitted.

[Alternative Embodiment] As shown in FIG. 3, the guide plate portion 3 extends vertically to the left and right edges of the return portion R,
The return portion R may be formed in the same shape as the H-shaped steel. or,
As shown in FIG. 4, a septic tank having a structure having a sludge withdrawal pipe 5 attached to the center of the partition wall W1 may be used.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the accompanying drawings.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a septic tank in an embodiment.

FIG. 2 is a schematic diagram of a septic tank in an embodiment.

FIG. 3 is a perspective view of a main part of a septic tank in another embodiment.

FIG. 4 is a perspective view of a main part of a septic tank according to another embodiment.

FIG. 5 is a perspective view of a main part of a conventional septic tank.

[Explanation of symbols]

 D1 diffuser E contact aeration tank P settling tank R return part W1 partition

──────────────────────────────────────────────────続 き Continuing from the front page (72) Katsumi Hamada, Inventor 2 at Takamatsu, Kosai-cho, Koga-gun, Shiga Prefecture Inside Kubota Shiga Plant (72) Inventor Dai Dai Harada 1-2-1, Takamatsu, Kosai-cho, Koga-gun, Shiga Prefecture Kubota Co., Ltd. Shiga Plant (56) References JP-A 63-63194 (JP, U) JP-A 4-131494 (JP, U) JP-A 59-93790 (JP, U) JP 1- 73397 (JP, U) Japanese Utility Model Showa 55-43544 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) C02F 3/00

Claims (1)

(57) [Claims] 1. A settling tank (P) is provided downstream of a contact aeration tank (E) in communication with a lower part of a partition (W1), and a dispersion for generating a circulation flow in the contact aeration tank (E). The trachea (D1) is dispersedly arranged left and right with respect to the direction of flow, and the contact aeration tank (E) is located at the lower end of the partition wall (W1) at the center in the width direction more than the left and right parts. A septic tank provided with a return portion (R) that protrudes greatly on the side.