JP2779684B2 - Scum removal device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a scum removal device for efficiently removing scum floating on the water surface at the end of biological treatment in a circulating water channel type aeration tank. .

[Conventional technology]

In the circulation channel type aeration tank, mixing and stirring are performed by a water flow circulating in the channel in the aeration step.

After a lapse of a predetermined time, the aeration apparatus is stopped at the end of the aeration step, and the process proceeds to the precipitation step. After the water flow is stopped, the water is drained as a supernatant.

[Problems to be solved by the invention]

Therefore, in the above method, even if the process proceeds from the aeration process to the precipitation process, it takes about 30 to 60 minutes for the water in the water channel to completely stop the water flow due to its inertia, and the supernatant water cannot be drained until the water flow stops.

There is also a drawback that the scum floating on the water surface is discharged together with the treated water even at the time of waste water of the supernatant water.

In order to prevent this, a method of installing a baffle plate in the supernatant water discharge section has been considered, but there is a disadvantage that scum accumulates in the treatment tank with this baffle plate.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a scum removing device capable of collecting scum floating in a sedimentation step by using inertia of a water stream, discharging and removing the scum, and discharging the scum separately from the supernatant water.

[Means for solving the problem]

The present invention has been made to achieve the above object, and a plate-like body is disposed at an upper position of a circulating water channel-type aeration tank so as to cross the circulating water channel at an angle to a water flow circulating in the circulating water channel. In addition, a scum discharging portion for discharging scum collected in a plate-like body to the outside of the processing tank is formed on an outer wall of the processing tank.

(Operation)

Even if the process is shifted from the aeration process to the precipitation process, it takes about 30 to 60 minutes for the water flow to stop in the circulation channel due to inertia.

Utilizing this inertial force, the scum floating on the water surface due to the water flow is collected on a plate-shaped body arranged diagonally to the water flow circulating in the circulation channel and across the circulation channel, and formed on the outer wall of the treatment tank. The scum is discharged from the scum discharge section to the outside of the processing tank.

Therefore, without waiting for the water flow to stop completely,
Drain the supernatant water.

〔Example〕

 Hereinafter, the present invention will be described based on illustrated embodiments.

In FIG. 1, reference numeral 1 denotes a circulating channel aeration tank having an oval, circular or other shape and having a circulating channel 2 formed therein. The processing tank 1 has a required depth and size. .

3 is an aeration device provided in the circulation channel 2 in this treatment tank,
One or a plurality of the aeration devices 3 are installed according to the size of the processing tank 1, thereby generating a water flow while stirring and aerating the treated water in the water channel, and providing a circulating water flow having a required speed. I am trying to do it.

The treatment tank 1 can be supplied with treated water up to a predetermined high water level.

Further, the plate-like body 4 is disposed at a high water level position, that is, at an upper position of the treatment tank 1 so as to cross the circulation water channel 2 obliquely to a water flow circulating in the circulation water channel 2.

The plate-like body 4 may be a simple elongated flat plate, or may have an L-shaped or gutter-shaped cross section.

Further, the scum collected by the plate-like body 4 is placed on the outer wall of the processing tank 1 on the upstream side near the position where the plate-like body 4 is disposed.
A scum discharging portion 5 such as a valve, a movable weir, and a gate for discharging to the outside is formed. The scum discharge unit 5 such as a valve, a movable weir, and a gate is configured so that scum can be selectively discharged to the outside of the processing tank 1 together with the processing water.

In this scum removal device, treated water flows into the treatment tank 1 from a low water level to a high water level, and the aeration device 3 is operated during or after the inflow to perform aerobic stirring to perform aerobic biological treatment.

By the operation of the aeration device, a circulating flow is generated in the treatment tank 1. However, even after the aeration device 3 is stopped and the sedimentation process is started,
The circulating flow lasts 30 minutes to 1 hour due to inertia.

By the way, when the aeration device 3 is stopped, the scum floats on the water surface and flows to the plate-shaped body 4 by the circulating flow. Because it is arranged across 2
It moves toward the outer wall of the circulation channel 2.

When the scum discharge unit 5 is opened when the scum is collected on the outer wall, the scum is discharged out of the treatment tank 1 together with a small amount of water.

When a gutter-shaped member having a cross section as shown in FIG. 4 is used as the plate-shaped member 4, the scum is stored in the gutter-shaped plate-shaped member 4, so that the scum can be efficiently used with a very small amount of water. Scum can be discharged.

〔The invention's effect〕

According to the scum removal device of the present invention, the scum floating on the water surface, without using equipment that requires a drive source such as a scum scraper, utilizing the flow of the treated water circulating in the circulating water channel, the circulating water channel With a plate-shaped body arranged diagonally to the circulating water flow and across the circulation water channel, it efficiently collects on the outer wall of the processing tank, and goes out of the processing tank from the scum discharge part formed on the outer wall of the processing tank. Can be discharged, thereby reducing the construction cost and running cost of the equipment,
Without mixing scum into the treated water discharged as supernatant water, clear treated water can be obtained,
It is possible to prevent scum from accumulating in the treatment tank and prevent the biological treatment efficiency from decreasing.

[Brief description of the drawings]

FIG. 1 is a plan view of an embodiment of a scum removing apparatus in which a processing tank has an oval shape, FIG. 2 is a plan view of an embodiment of a scum removing apparatus in which a processing tank has a circular shape, and FIG. 3 is a line A in FIG. FIG. 4 is a sectional view taken along line BB of FIG. 1 is a treatment tank, 2 is a circulation channel, 3 is an aerator, 4 is a plate-like body, 5 is a scum discharge part.

Claims (1)

(57) [Claims] 1. A plate-like body is disposed at an upper position of a circulating water channel type aeration treatment tank obliquely with respect to a water flow circulating through the circulating water channel so as to cross the circulating water channel, and on an outer wall of the processing tank, A scum removing device for forming a scum discharge section for discharging scum collected in a plate-like body out of a processing tank.