JPH0213120Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a sewage treatment equipment that processes sewage while circulating and cleaning granular media with biofilm attached.In particular, it prevents clogging of the air lift pipe when the circulation is stopped, and when restarting. This invention relates to sewage treatment equipment that can smoothly circulate media.

Recently, for example, as shown in FIG. 1, the granular media 2 filled in the processing tank 1 is brought from the lower part of the processing tank 1 to the upper part, and is circulated and moved by an air lift pipe 4 with an air nozzle 3 installed at the lower part. A sewage treatment device that cleans and treats sewage a is attracting attention. However, in this type of device, when the circulation of the medium 2 is stopped, much of the medium remains in the air lift pipe 4, and the granular medium 2 accumulates in the pipe 4, and the air lift pipe 4 is blocked, and when restarted, the medium 2 remains in the air lift pipe 4. The drawback was that the circulation of 2 became impossible.

This invention was made in order to eliminate the above-mentioned drawbacks.In addition to providing an air nozzle at the lower end of the air lift pipe, the tip of the water supply nozzle is inserted into the lower end of the air lift pipe, and after stopping the air supply, water is supplied for a predetermined period of time. It is an object of the present invention to provide a sewage treatment device that can prevent clogging of an air lift pipe when circulation is stopped by supplying water from a supply nozzle, and can smoothly and reliably circulate a medium when restarting.

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

As shown in FIG. 2, this invention has a lower hopper-shaped processing tank 1 filled with a medium 2, an air lift pipe 4 for circulating and moving this medium 2,
The air lift pipe 4 has an air nozzle 3 and a water supply nozzle 5 arranged at the lower part thereof.

The medium 2 is preferably a substantially spherical granular material such as coarse sand, anthracite, glass spheres, etc., and is formed so that a biofilm adheres thereto within the treatment tank 1.

Further, the air nozzle 3 is arranged below the air lift pipe 4, and the water supply nozzle 5 is located below the air lift pipe 4.
In particular, the nozzle tip is arranged at the lower end of the air lift pipe 4.

Next, the operation and effects of this invention will be explained.

First, when circulating the medium, the air from air nozzle 3 is
Only air b, or both air b from the air nozzle 3 and circulating water c from the water supply nozzle 5 are supplied simultaneously. As a result, the medium 2 at the bottom of the processing tank 1 is pulled out from the air lift pipe 4 and lifted and moved to the upper liquid section above the medium 2 layer. At this time, the excess biofilm adhering to the surface of the medium 2 is peeled off and removed, and the medium 2 moves downward on the outside of the air lift pipe 4 due to its own weight and is circulated. Then, the wastewater a supplied to the upper part of the treatment tank 1 through the supply pipe 6 flows into the second layer of media, flows down while removing BOD, SS, etc., and is then discharged from the drain pipe 7 as the treatment liquid d.

Furthermore, when the circulation is stopped, air b is first stopped, and the water supply is stopped after operating with only water c for, for example, several tens of seconds. The biological film attached to the surface of the medium 2 in the air lift pipe 4 is peeled off by the water c, and the medium 2 is discharged from the upper end of the pipe 4. At this time, especially since the tip nozzle of the water supply nozzle 5 is disposed within the air lift pipe 4, the medium 2 does not newly flow into the pipe 4. Therefore, clogging by the medium 2 in the air lift pipe 4 can be effectively prevented, and the medium 2 can be circulated smoothly and reliably at the time of restart.

Note that a part of the normal treatment liquid d is used as the water c supplied to the water supply nozzle 5.

As described above, according to this invention, the amount of media remaining in the air lift can be extremely reduced (in extreme cases, it is all exhausted), so when the amount remaining is small, it is possible to prevent the media from clogging the air lift pipe. At the time of restart, the settled residual medium can be easily brought into a floating state, and the granular medium can be circulated smoothly and reliably.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a conventional device, and FIG. 2 is a vertical cross-sectional view of an embodiment of this invention. 1... Processing tank, 2... Medium, 3... Air nozzle, 4... Air lift pipe, 5... Water supply nozzle.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A treatment tank that is provided with a supply pipe for raw water at the top and a drainage pipe for treated water at the bottom, and a medium filled in this treatment tank. an air lift pipe disposed within the medium layer for circulating the medium; an air nozzle disposed below the air lift pipe for ejecting air to circulate and clean the medium; a water supply nozzle disposed at the bottom of the pipe, the water supply nozzle raising the medium remaining in the air lift pipe when the circulation of the medium is stopped, and spouting water to be discharged from the air lift pipe. , A sewage treatment device characterized in that the air lift pipe is prevented from clogging. (2) The sewage treatment device according to claim 1, wherein the tip nozzle of the water supply nozzle is disposed within the air lift pipe.