JP2001225089A - Septic tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a septic tank constituted so that wastewater is necessarily passed through first and second cleaning treatment chambers from a discharge port, even if a large quantity of wastewater flows in the septic tank suddenly, to be discharged as cleaned water. SOLUTION: The septic tank 1 is demarcated into a receiving chamber 10, a first cleaning treatment chamber 11, a second cleaning treatment chamber 12 and a treated water chamber 13 by partition walls 2, 3, 4. Wastewater is treated in a filter bed 23 and a biological membrane filter bed 26 to be discharged through the treated water chamber 13. When a large quantity of wastewater flows in the receiving chamber 10 suddenly and the water levels of the first and second cleaning treatment chambers 11, 12 are raised suddenly, the water in the second cleaning treatment chamber 12 flows out to the treated water chamber through a backwashing water supply pipe 31. Since the level of the upper end of the partition wall 3b separating the first cleaning treatment chamber 11 and the treated water chamber 13 is higher than the level of the upper end of the backwashing water supply pipe 31, the water in the first cleaning treatment chamber 11 is prevented from overflowing the partition wall 3b to flow in the treated water chamber 13 in a short-circuited manner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a septic tank such as a small-sized combined septic tank for treating wastewater.

[0002]

2. Description of the Related Art The structure of a conventional septic tank will be described with reference to FIGS. FIG. 3 is a perspective view showing a state in which the upper part of the septic tank is removed, FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3, and FIG. 5 is a sectional view taken along the line VV in FIG. FIG. 6 is a perspective view showing a configuration near the advection port 24, and FIG. 7 is a schematic longitudinal sectional view showing a processing system in the septic tank.

[0003] In the septic tank 1, a receiving chamber 10, a first purification chamber 11, and a second purification chamber 1 are separated by partitions 2, 3, 4.
2 and a treated water chamber 13. Drainage flows into the receiving chamber 10 via the inlet 20. The coarse solids settle in the receiving chamber 10.

[0004] An advection tube 21 and an advection port 22 are provided above the partition wall 2 separating the receiving chamber 10 and the first purification processing chamber 11, and water in the receiving chamber 10 is supplied to the advection tube 21 and the advection port. The gas flows into the lower part of the first purification processing chamber 11 through 22. In the first purification processing chamber 11, a filter bed 23 made of a ceramic particulate filter material, a plastic mesh filter material, or the like is provided so as to separate a lower portion and an upper portion thereof. When the wastewater passes through the filter bed 23 from below to above, the wastewater is anaerobically purified by anaerobic microorganisms attached to the filter medium.

[0005] The water flowing out of the filter bed 23 flows into the upper part of the second purification processing chamber 12 through the advection port 25 provided in the partition wall 3. The advection port 25 is provided with a check valve 25a for preventing backflow of water from the second purification processing chamber 12 to the first purification processing chamber 11. In FIG. 5, the check valve 25a is omitted for clarity. A biofilm filtration layer 26 is provided in the second purification processing chamber 12 so as to separate the upper part and the lower part. The water that has flowed into the upper part of the second purification treatment chamber 12 from the advection port 25 is subjected to a filtration treatment by passing through the biofilm filtration layer 26 from above to below, and air is blown from the air diffuser 24. It is purified by aerobic microorganisms attached to the filter medium.

[0006] The water that has passed below the biofilm filtration layer 26 is transferred to the treated water chamber 13 via an air lift 30 from an opening 27 provided below the partition wall 4. When the air lift 30 is not operated, the water in the second purification processing chamber 12 does not flow to the treated water chamber 13.

As shown in FIG. 7, the water in the treated water chamber 13 overflows into a disinfecting tank 35 having a disinfecting cylinder 34, and after being disinfected, is discharged through a discharge tank 36 and a discharge port 37 to a sewer pipe or the like. Released.

To backwash the biofilm filtration layer 26, one end of a backwash water supply pipe 31 is connected to an opening 28 provided at the lower part of the partition wall 4. The backwash water supply pipe 31 is raised upward in the treated water chamber 13 so that the middle part thereof is at the highest position, and the other end is lowered to the lower part in the treated water chamber 13. A non-self-priming backwash pump 32 is connected to the other end of the backwash water supply pipe 31.

The backwash water supply pipe 31 is formed by connecting two (or two or more) pipes by a flange 31f. In this conventional example, flanges 31f are respectively arranged at the highest positions of the backwash water supply pipes 31, and these flanges 31f are connected to each other by bolts and nuts. The flange 31f connecting the pipes in this way
Is disposed at the highest position of the backwash water supply pipe 31 in order to facilitate the work of connecting or disconnecting the flanges 31f.

The partition wall 3 and the partition wall 4 have a T shape in plan view.
They intersect to form a letter. The partition wall 3 not only separates the first purification processing chamber 11 and the second purification processing chamber 12,
The first purification treatment chamber 11 and the treated water chamber 13 are also separated. The partition wall 4 extends so as to connect a middle part of the partition wall 3 in the width direction and the inner surface of the purification tank 1, and the partition wall 4 separates the second purification processing chamber 12 and the treated water chamber 13. . In each of the figures, the partition 4 and the partition 3
The reference numeral 3a is attached to the second purification treatment chamber 12 side and the reference numeral 3b is attached to the treated water chamber 13 side from the connection portion with.

The advection port 25 is provided in the partition wall 3a.

[0012] A backwash drainage return pipe 39 is disposed so as to straddle the upper part of the partition wall 3a and the upper part of the partition wall 2. When the backwash pump 32 is operated, the treated water in the treated water chamber 13 flows into the lower part of the second purification treatment chamber 12 through the backwash water supply pipe 31 and moves the biofilm filtration layer 26 from bottom to top. By backflow, the biofilm filtration layer 26 is backwashed.

Although the water level in the second purification chamber 12 rises with this backwashing, the water in the second purification chamber 12 is transferred to the first purification chamber 11 because the check valve 25a is provided. Does not flow backward, and the water level in the second purification processing chamber 12 gradually rises. The water level in the second purification processing chamber 12 is equal to the backwash wastewater return pipe 39.
When the level reaches the second level, the second
It flows into the receiving room 10 from the purification processing room 12. By operating the air lift 30 after stopping the backwash pump 32, the water level in the second purification processing chamber 12 drops to a level lower than the advection port 25.

A small hole 33 for communicating with the atmosphere is provided above the backwash water supply pipe 31. By providing the small holes 33, the backwash water supply pipe 31 does not function as a siphon pipe, but has only a function of supplying backwash water.

[0015]

In the above-mentioned conventional septic tank, the level at the upper end of the partition 3b is lower than the level at the upper end of the partition 3a, as shown in FIGS. This is because when a large amount of wastewater suddenly flows into the receiving chamber 10 and the water level in the first purification processing chamber 11 rises sharply with this, the upper end of the partition wall 3b overflows and the processing is performed. Water room 1
3 to prevent water from overflowing from the septic tank 1.

However, since the water in the upper part of the first purification treatment chamber 11 has not been subjected to the purification treatment yet, when the water overflows from the partition wall 3b into the treatment water chamber 13, the discharge port is temporarily provided. The quality of the water discharged from 37 will be degraded.

The present invention has been made to solve the above problems, and to provide a septic tank configured so that even after a large amount of wastewater temporarily flows into the septic tank, the purified water is discharged. With the goal.

[0018]

The septic tank according to the present invention is constructed such that the inside of the tank is divided into an inflow chamber, a first purification chamber, a second purification chamber, and a treated water chamber by a partition wall from the upstream side. One end is communicated with the lower part of the purification treatment chamber, the middle part is raised upward, and the other end is provided with a backwash water supply pipe connected to a backwash pump in the treatment water chamber. The upper end level of the partition partitioning the treated water chamber and the first purification treatment chamber is higher than the upper end level of the backwash water supply pipe.

In such a septic tank, the wastewater treatment at normal time is performed in the same manner as in a conventional septic tank. When a large amount of wastewater suddenly flows into the receiving chamber and the water level in the first purification processing chamber rises rapidly, the water level in the second purification processing chamber also rises accordingly.

In the present invention, when the water level in the second purification processing chamber rises, water in the second purification processing chamber flows out to the treatment water chamber through the backwash water supply pipe. Since the level of the upper end of the partition wall separating the first purification processing chamber and the treated water chamber is higher than the level of the upper end of the backwash water supply pipe, water in the first purification processing chamber overflows the partition wall and is short-circuited. It does not flow into the treated water chamber.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below with reference to FIGS. 1 and 2 are cross-sectional perspective views of a septic tank according to the embodiment. FIG. 1 is a cross-sectional view of a portion corresponding to FIG. 3, and FIG.
It is sectional drawing of the part corresponding to a figure.

In this embodiment, the level of the upper end of the partition 3b is made higher than that of the prior art, and is equal to that of the partition 3a. Further, the upper end level of the backwash water supply pipe 31 is lower than the conventional one, and lower than the upper end level of the partition wall 3b.
Note that the upper end level of the backwash water supply pipe 31 is
Level of flooding. Other configurations are the same as those of the conventional example, and the same portions are denoted by the same reference numerals.

In the thus configured septic tank,
Normal wastewater treatment is performed in the same manner as in a conventional septic tank. The air lift 30 is activated when the water level in the second purification processing chamber 12 is equal to or higher than a specified water level, and is stopped when the water level in the processing chamber 12 is equal to or lower than the specified water level.

When a large amount of wastewater suddenly flows into the receiving chamber 10 and the water level in the first purification chamber 11 rises rapidly, the water level in the second purification chamber 12 also rises.

In the present invention, the second purification chamber 1
When the water level of the second purification treatment chamber 2 becomes high, the water in the purification treatment chamber 12 is transferred to the treatment water chamber 13 by the air lift 30, and the water in the second purification treatment chamber 12 also passes through the backwash water supply pipe 31. Leaks to In this case, the water level difference between the inside of the second purification treatment chamber 12 and the treated water chamber 13 is used as a driving force as the driving water supply pipe 3.
1 flows out from the purification treatment chamber 12 to the treated water chamber 13. The water flowing from the purification treatment chamber 12 to the treated water chamber 13 through the backwash water supply pipe 31 is supplied to the non-self-priming pump 3.
2 and flows into the treated water chamber 13.

As described above, the water in the second purification processing chamber 12 is promptly transferred to the treated water chamber 13 by both the air lift 30 and the backwash water supply pipe 30, and the first purification processing chamber 11 is Since the level of the upper end of the partition wall 3 b separating the water chamber 13 is higher than the level of the upper end of the backwash water supply pipe 31, the water in the first purification treatment chamber 11 is not filled.
b does not overflow and flow into the treated water chamber 13 in a short-circuit manner.

Therefore, even when a large amount of wastewater suddenly flows into the septic tank, the purified water is always discharged from the discharge port 37 through the first and second purification chambers 11 and 12. become.

[0028]

As described above, according to the present invention, even if a large amount of wastewater suddenly flows into the septic tank, the water that has been purified through the first and second purification chambers must be discharged from the discharge port. Will be released. Thereby, the quality of the discharged water is always good.

[Brief description of the drawings]

FIG. 1 is a sectional perspective view of a septic tank according to an embodiment.

FIG. 2 is a sectional perspective view of a septic tank according to the embodiment.

FIG. 3 is a perspective view of a conventional septic tank with an upper part removed.

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3;

FIG. 5 is a sectional view taken along the line VV in FIG. 4;

FIG. 6 is a perspective view showing a configuration near a convection port 24 of a conventional septic tank.

FIG. 7 is a schematic longitudinal sectional view showing a processing system in a conventional septic tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Septic tank 2, 3 (3a, 3b), 4 Partition wall 10 Receiving room 11 First purification chamber 12 Second purification chamber 13 Treated water chamber 23 Filter bed 24 Air diffuser 26 Biofilm filtration layer 30 Air lift 31 Backwash water supply Pipe 32 Backwash pump 39 Backwash drain return pipe

Claims (1)

[Claims] 1. An inside of a tank is partitioned by a partition wall from an upstream side into an inflow chamber, a first purification processing chamber, a second purification processing chamber, and a treated water chamber, and one end communicates with a lower part of the second purification processing chamber. , A backwashing water supply pipe connected to a backwashing pump at the other end thereof is connected to a backwashing pump, and the backwater pump is connected to the backwater pump. A septic tank, wherein the upper end level of the partition wall for partitioning the backwash water is higher than the upper end level of the backwash water supply pipe.