JPS6221354Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an improvement of a septic tank that can adjust the sludge concentration in the contact aeration chamber.

Conventionally, in sewage purification treatment equipment using the contact aeration method, in order to perform effective treatment, when the sludge concentration in the aeration chamber becomes high, the mixed liquid in the aeration chamber is pumped up using a pump, etc., and sent to the previous stage, such as a sedimentation separation chamber. It was sent back and the concentration was adjusted. If the above operations are neglected, the concentration of the mixed liquid in the aeration chamber will increase, the supernatant water will contain a large amount of solid matter, and the quality of the effluent will deteriorate. It has also been proposed to automatically return sludge using the stirring force in the aeration chamber, but in this case it has been difficult to adjust the amount of return.

This invention solves the above-mentioned drawbacks by utilizing the flow of the mixed liquid from the discharge port of the aeration device above the guide cylinder installed in the contact aeration chamber, without requiring means such as a pump. The sludge in the contact aeration chamber is returned to the separation chamber or an independent sludge storage chamber, and the amount of sludge returned can be adjusted by rotating the direction of the discharge port, creating a septic tank that can perform stable treatment. The purpose is to provide.

An embodiment of this invention will be described below with reference to the drawings.

As shown in FIG. 1, the inside of a septic tank main body 1 made of, for example, FRP is divided by two partition walls 2 and 3 into a separation chamber 4, a contact aeration chamber 5, and a precipitation chamber 6. And the septic tank main body 1
An inflow pipe 7 for sewage that communicates with the separation chamber 4 and an outflow pipe 8 that communicates with the settling chamber 6 are provided on the side wall of the tank.
The separation chamber 4 and the contact aeration chamber 5 are communicated by an advection pipe 9 which also serves as a sludge return port, and the contact aeration chamber 5 and the settling chamber 6 are connected between the lower end of the partition wall 3 and the bottom of the tank. They are communicated through the remaining opening 10.

The upper cover plate of the contact aeration chamber 5 is shown in FIG.
As shown in FIG. 2, an electric motor 11 is installed, and its rotating shaft 12 extends toward the liquid level of the contact aeration chamber 5. An impeller 13 is attached to its tip and rotated below the liquid level. A guide cylinder 14 is provided below the rotating shaft 12 and coaxially therewith. A draft pipe 15 rotatably inserted into the guide tube 14 is fixed to the frame of the electric motor 11, and is arranged to surround the impeller to form an aeration device. This guide cylinder 14 is supported by a member 16 installed between the partition walls 2 and 3, and the impeller 13
By the rotation of the guide tube 14, liquid is lifted up from the lower end opening of the guide tube 14.

Further, as shown in FIGS. 2 to 4, the draft pipe 15 has a plurality of discharge ports 17 on its upper end peripheral wall.
is provided and is rotatably installed with respect to the guide tube 14, so the direction of the discharge port 17 with respect to the advection tube 9 can be adjusted by rotation, and the contact aeration chamber 5
The amount of SS returned to the separation chamber 4 via the advection pipe 9 can be adjusted.

Next, the operation of this invention will be explained.

The wastewater to be treated flows into the separation chamber 4 from the inflow pipe 7, undergoes precipitation and separation, and then flows into the contact aeration chamber 5 from the advection pipe 9. In this contact aeration chamber 5,
Due to the rotation of the impeller 13, an upward flow is formed in the guide tube 14, and the liquid in the tank is forcibly circulated through the guide tube 14, the discharge port 17 of the draft pipe 15, the material 16, and the guide tube 14, and is also subjected to aeration treatment. The mixed liquid is sequentially transferred from the opening 10 to the settling chamber 6, where the sludge undergoes sedimentation treatment and is returned to the contact aeration chamber 5 by gravity, while the supernatant liquid is discharged from the outflow pipe. be done.

At this time, the direction of the discharge port 17 of the draft pipe 15 is rotationally adjusted with respect to the advection port 9a of the advection pipe 9, and as shown in FIGS. It is possible to return the mixed liquid containing SS and the like therein to the separation chamber 4 or to stop it, and furthermore to shift the direction of the discharge port 17 with respect to the advection port 9a to adjust the amount of return. Note that the aeration device may be replaced with an impeller and may be configured to diffuse air within the guide cylinder.

As described above, according to this invention, by rotating and adjusting the discharge port of the aeration device to a position opposite to the advection port of the separation chamber, the mixed liquid containing solids in the contact aeration chamber is returned to the preceding separation chamber. As a result, only the liquid that does not contain solids that has flowed into the separation chamber and has been precipitated and separated can flow into the contact aeration chamber, and by repeating this,
Suspended solids in the contact aeration chamber can be significantly reduced, allowing stable and efficient wastewater treatment. Further, by adjusting the rotation of the discharge port of the aeration device, the amount of mixed liquid transferred and the sludge concentration in the contact aeration chamber can be easily adjusted.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view of one embodiment of this invention;
The figure shows an enlarged vertical sectional view of the main part of this invention, and FIGS. 3 and 4 show front views of the main part. 1... Septic tank body, 4... Separation chamber, 5... Contact aeration chamber, 7... Inflow pipe, 8... Outflow pipe, 9... Advection pipe, 14... Guide tube, 15... Draft pipe, 1
7...Discharge port.

Claims (1)

[Scope of utility model registration request] A pre-separation chamber provided in the septic tank main body for sedimentation and separation of inflow sewage, a contact aeration chamber connected to this separation chamber via an advection port, a guide tube provided in the contact aeration chamber, and an aeration device that circulates the liquid in the tank by lifting up the liquid in the guide tube and discharging it in a radial direction, and rotating the discharge port of the aeration device above the guide tube at a position corresponding to the advection port. The septic tank is configured such that the liquid mixture containing solids in the contact aeration chamber can be returned to the separation chamber.