JP7773455B2 - septic tank - Google Patents

Description

The present invention relates to a septic tank equipped with a water treatment unit that treats water to be treated, an inlet through which the water to be treated flows into the water treatment unit, and a baffle connected to the inlet.

Conventional septic tanks are equipped with baffles to prevent the scum (lumps of sludge) floating on the water surface from being crushed by the force of the water being treated when the water flowing from the inlet flows into the water treatment section of the septic tank.

Furthermore, if the water to be treated passes through the baffle member and heads toward the bottom of the water treatment unit with force, it will stir up and stir up the sludge that has accumulated at the bottom. For this reason, a receiving section is provided on the wall of the baffle member opposite the inlet section to receive the water to be treated. By reducing the force of the water to be treated in this receiving section, the sludge that has accumulated there is prevented from being stirred up.

Japanese Patent Application Laid-Open No. 2004-136187

In conventional septic tanks, there is a relatively large distance between the inlet and the wall of the baffle member facing it. Therefore, when the inflow rate of water to be treated is relatively high, the receiving portion of the baffle member functions properly, but when the inflow rate of water to be treated is low, the water to be treated has difficulty passing through the receiving portion, making it difficult to prevent sludge from being stirred up.

The present invention was made in consideration of the above-mentioned circumstances, and its purpose is to provide a septic tank equipped with a baffle that can reduce the momentum of the water being treated regardless of the amount of water flowing into it.

The feature of the septic tank according to the present invention is that the septic tank includes a water treatment unit that treats water to be treated, an inlet through which the water to be treated flows into the water treatment unit, and a baffle connected to the inlet.
a lateral receiving surface extending laterally for receiving the water to be treated is formed on a front wall of the baffle located in front of the inlet portion,
A pipe capable of transporting the water to be treated extends from the inlet toward the front wall of the baffle, and the water to be treated discharged from the opening of the pipe is received by the lateral receiving surface and then discharged from the outlet of the baffle.

In the septic tank of the present invention, it is preferable that the front wall of the baffle has a vertical surface rising from the bottom of the baffle, a horizontal support surface connected to the vertical surface, and a vertical support surface connected to the horizontal support surface and extending vertically.

In the septic tank of the present invention, it is preferable that the lateral receiving surface is inclined toward the inlet.

In the septic tank of the present invention, it is preferable that the inclination angle of the lateral receiving surface relative to the horizontal plane be between 20° and 35°.

In the septic tank of the present invention, it is preferable that the opening of the piping be located approximately directly above the lower end of the front wall of the baffle or above the lateral support surface.

In the septic tank of the present invention, it is preferable that the horizontal distance between the end of the lateral support surface on the inlet side and the opening of the piping is 10 mm to 20 mm.

A pipe capable of transporting untreated water extends from the inlet toward the front wall of the baffle. As a result, untreated water discharged from the opening of the pipe is received by the lateral receiving surface of the baffle before being discharged from the baffle's outlet. This allows the momentum of the untreated water to be reduced even when the inflow rate of the untreated water is small. Therefore, the baffle of the present invention makes it possible to reduce the momentum of the untreated water regardless of the inflow rate of the untreated water. As a result, the sludge accumulated at the bottom of the solid-liquid separation tank is prevented from being stirred up and stirred up, thereby reducing the outflow of sludge to subsequent tanks. Furthermore, because the sludge remains stationary, it becomes more compacted and thickened, increasing the amount of space other than sludge, further reducing the outflow of sludge to subsequent tanks.

FIG. 1 is a vertical cross-sectional side view showing the schematic configuration of a septic tank. FIG. 1 is a cross-sectional plan view showing a schematic configuration of a septic tank. FIG. 2 is a vertical cross-sectional side view showing a schematic configuration of a baffle. FIG. 4 is an explanatory diagram showing the flow of water to be treated in a baffle. FIG. 10 is a vertical cross-sectional side view showing a schematic configuration of a baffle according to another embodiment. FIG. 10 is an explanatory diagram showing the flow of water to be treated in a baffle according to another embodiment.

Hereinafter, an embodiment of a septic tank according to the present invention will be described with reference to the drawings.
[Septic tank]
1 and 2, the main body of the septic tank 1 according to this embodiment is equipped with a solid-liquid separation tank 2 (an example of a water treatment unit), an anaerobic filter bed tank 3, a carrier fluidized bed tank 4, a treated water tank 5, and a disinfection tank 6. In this embodiment, the longitudinal direction of the septic tank 1 refers to the direction in which the solid-liquid separation tank 2, anaerobic filter bed tank 3, and carrier fluidized bed tank 4 are aligned in the septic tank 1, and the width direction of the septic tank 1 refers to the direction perpendicular to the longitudinal direction in a plan view.

The raw water to be treated (W) flows into the solid-liquid separation tank 2 through the inlet 7, and is then transported through the anaerobic filter bed tank 3, the carrier fluidized bed tank 4, the treated water tank 5, and the disinfection tank 6 in that order. After being treated in each tank, the water is discharged from the discharge port 8.

The solid-liquid separation tank 2 is configured to receive and temporarily store the water to be treated W that flows in from the inlet 7. The solid-liquid separation tank 2 separates relatively large impurities, solids, etc. contained in the water to be treated W by gravitational settling, and floating suspended matter such as scum is stored in the upper part of the tank, while sludge is stored in the bottom of the tank.

The anaerobic filter bed tank 3 is equipped with anaerobic filter material 30. As the water to be treated W passes through the anaerobic filter material 30, suspended solids are separated, organic matter is decomposed by anaerobic microorganisms, and nitrate and nitrite nitrogen are denitrified.

In this embodiment, the carrier fluidization tank 4 is equipped with a fluidized carrier and an aeration tube (not shown).

The carrier fluidization tank 4 contains and holds multiple fluidized carriers that carry microorganisms and can flow with the water to be treated W. One example of a fluidized carrier is a square sponge-like carrier with a specific gravity of approximately 1.01 and dimensions of 20 mm x 20 mm. The material of the fluidized carrier is, for example, polyurethane (PU). The shape, size, and material of the fluidized carrier are not limited to the above configurations, and any configuration may be used as long as it is deemed to have equivalent or better durability and treatment performance.

The air diffuser is located near the bottom of the carrier fluidized bed 4, and is configured so that air bubbles are released from the air diffuser by air supply from a blower (not shown) installed outside the bed.

When bubbles are released from the aeration pipe, they are supplied to the carrier fluidized bed 4. This causes the fluidized bed to swirl within the carrier fluidized bed 4, where the microorganisms attached to the fluidized bed carry out aerobic decomposition of organic matter and nitrification of ammonia nitrogen.

The water to be treated W treated in the carrier fluidization tank 4 flows into the treatment tank 5 via a convection section located at the bottom of the partition separating the carrier fluidization tank 4 and the treatment tank 5.

In addition, a circulation air lift pump AP is installed in the carrier fluidization tank 4 adjacent to the treated water tank 5, and is configured so that the exfoliated sludge and a portion of the water to be treated W are constantly transferred as circulating water to the baffle 9 in the solid-liquid separation tank 2 via the circulation return pipe. Air is supplied to the air lift pump AP from a blower (not shown) installed outside the tank.

The treated water tank 5 temporarily stores the water W treated in the carrier fluidization tank 4, and separates any exfoliated sludge that could not be captured in the carrier fluidization tank 4, preventing the sludge from leaking out.

The water to be treated W treated in the treatment tank 5 flows through a convection section installed at the top of the partition separating the treatment tank 5 and the disinfection tank 6 and overflows into the disinfection device (not shown) in the disinfection tank 6. The water to be treated W disinfected by coming into contact with a disinfectant in the disinfection device is then discharged outside the tank from the discharge port 8.

[Baffle]
In this embodiment, the baffle 9 is a member with an approximately rectangular cross section, having a front wall 90 located in front of the inlet section 7, a rear wall 91 located opposite the front wall 90, a right side wall 92 and a left side wall 93 arranged opposite each other in the width direction, and a bottom 94.

The baffle 9 is connected to the inlet section 7 via the rear wall 91. A pipe 70 capable of transporting the water to be treated W is fitted into the inlet section 7. Note that the pipe 70 may be configured integrally with the inlet section 7.

A lateral receiving surface 902 extending laterally is formed on the front wall 90 of the baffle 9 to receive the water to be treated W. The lateral receiving surface 902 is located at a position that is always below the water level WL of the water to be treated W.

In this embodiment, the outlet 95 through which the treated water W flows out is formed in the bottom 94 of the baffle 9.

A pipe 70 capable of transporting the water to be treated W extends from the inlet 7 toward the front wall 90 of the baffle 9. As a result, the water to be treated W discharged from the opening 71 of the pipe 70 is received by the lateral receiving surface 902 of the baffle 9 and then discharged from the outlet 95 of the baffle 9.

As a result, even if the inflow volume of the water to be treated W is small, the momentum of the water to be treated W can be reduced. Therefore, the baffle 9 in this embodiment makes it possible to reduce the momentum of the water to be treated W regardless of the inflow volume of the water to be treated W. As a result, the sludge accumulated at the bottom of the solid-liquid separation tank 2 is prevented from being stirred up and stirred up, thereby reducing the outflow of sludge to the next tank (anaerobic filter bed tank 3 in this embodiment) and beyond. Furthermore, because the sludge continues to remain stationary, the sludge becomes more compacted and thickened, and the space other than the sludge increases, further reducing the outflow of sludge to the next tank and beyond.

In this embodiment, the front wall 90 of the baffle 9 is formed with a vertical surface 901 rising from the bottom 94 of the baffle 9, a horizontal receiving surface 902 connected to the vertical surface 901, and a vertical receiving surface 903 connected to the horizontal receiving surface 902 and extending vertically.

In this embodiment, the opening 71 of the piping 70 is located approximately directly above the lower end of the front wall 90 of the baffle 9. However, the position of the opening 71 of the piping 70 is not limited to this, and it may also be located above the lateral receiving surface 902.

As shown in this embodiment, the lateral receiving surface 902 is preferably inclined toward the inlet 7. In this case, the inclination angle θ of the lateral receiving surface 902 relative to the horizontal plane is preferably between 20° and 35°.

As a result, as shown in FIG. 4, the untreated water W discharged from the opening 71 of the pipe 70 is received by the lateral receiving surface 902 of the baffle 9. Because the lateral receiving surface 902 is inclined toward the inlet section 7, the untreated water W flows toward the rear wall 91, which is in the opposite direction to the inflow direction, and then descends and is discharged from the outlet 95. Furthermore, the inclination angle θ of the lateral receiving surface 902 relative to the horizontal plane is neither too steep nor too flat, but is a moderate inclination of 20° to 35°. This allows the flow rate of the untreated water W to be slowed down, and solids contained in the untreated water W do not accumulate on the horizontal surface of the lateral receiving surface 902, allowing the water to flow smoothly downward. In other words, the space within the baffle 9 is utilized more effectively, and the momentum of the untreated water W can be more reliably reduced.

Furthermore, if the opening 71 of the pipe 70 is not located above the lateral receiving surface 902, it is desirable that the horizontal distance T between the end of the lateral receiving surface 902 on the inlet section 7 side and the opening 71 of the pipe 70 be 10 mm to 20 mm.

Other Embodiments
In the above-described embodiment, the outlet 95 through which the water to be treated W is extracted is formed in the bottom 94 of the baffle 9, but the present invention is not limited to this configuration. For example, as shown in Figures 5 and 6, the outlet 95 through which the water to be treated W flows may be formed in the lower part near the bottom 94 of each of the right side wall 92 and the left side wall 93 of the baffle 9. Furthermore, when the outlet 95 is provided in a side wall of the baffle 9, it may be provided on any of the front, rear, left and right sides of the side wall. That is, in this embodiment, it may be provided on any of the front wall 90, the rear wall 91 (if there is a gap between the septic tank body), the right side wall 92, and the left side wall 93, and may be provided in one location or in multiple locations.

Although the present invention has been described above with reference to the drawings, it goes without saying that the present invention is not limited to the configuration shown in the drawings, and can be embodied in various forms without departing from the spirit and scope of the present invention.

The septic tank of the present invention can be applied not only to small septic tanks, but also to medium-sized and large septic tanks.

1 Purification tank 2 Solid-liquid separation tank (an example of a water treatment unit)
3 Anaerobic filter bed tank 30 Anaerobic filter material 4 Carrier fluidized bed tank 5 Treated water tank 6 Disinfection tank 7 Inlet 70 Pipe 71 Opening 8 Discharge port 9 Baffle 90 Front wall 901 Vertical surface 902 Horizontal receiving surface 903 Vertical receiving surface 91 Back wall 92 Right side wall 93 Left side wall 94 Bottom 95 Outlet W Treated water WL Water level AP Air lift pump T Distance θ Tilt angle

Claims (4)

A septic tank comprising a water treatment unit that treats water to be treated, an inlet through which the water to be treated flows into the water treatment unit, and a baffle connected to the inlet,
a lateral receiving surface extending laterally for receiving the water to be treated is formed on a front wall of the baffle located in front of the inlet portion,
A pipe capable of transporting the water to be treated extends from the inlet portion toward the front wall side of the baffle, and the water to be treated discharged from the opening of the pipe is received by the lateral receiving surface and then discharged from the outlet of the baffle ,
a front wall of the baffle including a vertical surface rising from a bottom of the baffle, a horizontal receiving surface connected to the vertical surface, and a vertical receiving surface connected to the horizontal receiving surface and extending in the vertical direction;
A septic tank in which the opening of the piping is located approximately directly above the lower end of the front wall of the baffle or above the lateral support surface . A septic tank comprising a water treatment unit that treats water to be treated, an inlet through which the water to be treated flows into the water treatment unit, and a baffle connected to the inlet,
a lateral receiving surface extending laterally for receiving the water to be treated is formed on a front wall of the baffle located in front of the inlet portion,
A pipe capable of transporting the water to be treated extends from the inlet portion toward the front wall side of the baffle, and the water to be treated discharged from the opening of the pipe is received by the lateral receiving surface and then discharged from the outlet of the baffle,
a front wall of the baffle including a vertical surface rising from a bottom of the baffle, a horizontal receiving surface connected to the vertical surface, and a vertical receiving surface connected to the horizontal receiving surface and extending in the vertical direction;
A septic tank in which the horizontal distance between the end of the lateral receiving surface on the side of the inlet portion and the opening of the piping is 10 mm to 20 mm . 3. The septic tank according to claim 1 , wherein the lateral receiving surface is inclined toward the inlet portion. The septic tank according to claim 3, wherein the inclination angle of the lateral receiving surface relative to the horizontal plane is between 20° and 35°.