JP2562935Y2 - Pressure regulating type flow regulator in sewage treatment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure regulating type flow control device for controlling a flow rate from an activated sludge reaction tank in sewage treatment.

[0002]

2. Description of the Related Art In a sewage treatment plant, for example, treated water and the like are circulated from an activated sludge reactor to a sedimentation basin. By the way, the amount of inflow of sewage and the like into these sewage treatment facilities has a large temporal fluctuation during the day, and the tendency is particularly large in small-scale sewage, and adjustment of the fluctuation is a major issue. For this reason, conventionally, a flow control tank is provided, but the construction cost is high. If a flow control tank is not provided, the treatment function of the activated sludge will be affected, and the treatment function of the sedimentation basin will be directly affected by fluctuations in the flow rate.

[0003]

In order to improve the above problem, it is desirable to equalize the amount of water flowing into the sedimentation basin. For that purpose, for example, a flow control device as described in Japanese Utility Model Laid-Open No. 1-90824 is effective. According to this device, even if the water level on the upstream side changes, the overflowing flow rate does not change, and a constant flow rate of liquid can always be supplied from the upstream side to the downstream side, and the structure is extremely simple. .
However, this apparatus has a problem in that it is difficult to discharge scum from a reaction tank for sludge treatment, and is not suitable for an actual activated sludge method.

The present invention is intended to solve the above-mentioned drawbacks of the conventional flow control device, and to provide a device capable of discharging scum, which can be used in an activated sludge treatment facility for sewage. Things.

[0005]

The structure of the present invention for achieving the above object will be described with reference to the drawings corresponding to the embodiments.
An outlet 3 for the treated water is opened in the tank wall 2 of the reactor 1 below the standard water level of the reactor 1, and the outlet 3 is enclosed outside the tank wall 2 by surrounding the outlet 3. Box 5
In the upper part of the box 5, a compressed air inlet pipe 6 and an air purge pipe 7 whose tip is opened at a height near the upper end of the outlet 3 of the reaction vessel 1 are connected. In addition, a drain pipe for discharging the treated water flowing into the box 5 to the outside of the box 5 is provided below the box 5 with an opening 9 at a position below the lower end of the outflow hole.
A weir plate 10 is provided between the drain pipe 8 and the tank wall 2 in the inside.

A pressure regulating type flow regulating device according to a second aspect of the present invention comprises:
An outlet 3 for treated water is provided in the tank wall 2 of the reaction tank 1 below the standard water level of the reaction tank 1, and the outlet 3 is enclosed outside the tank wall 2 so as to surround the outlet 3. Box 5
In the upper part of the box 5, a compressed air inlet pipe 6 and an air purge pipe 7 whose tip is opened at a height near the upper end of the outlet 3 of the reaction vessel 1 are connected. In addition, a drain pipe 8 for discharging the treated water flowing into the box 5 to the outside of the box 5 is provided below the box 5 at the outlet 3.
The opening 9 is provided below the lower end of the opening.

[0007]

Since the flow rate adjusting device of the present invention is constructed as described above, if the compressed air is sent from the inlet pipe 6, the water level in the reaction tank 1 will be higher than the lower end of the air purge pipe 7. When the water level is set to, the pressure in the space inside the closed box 5 is equal to the water pressure of the water immersion depth h of the air purge pipe 7. Therefore, when the water level of the reaction tank 1 fluctuates, the water immersion depth h of the air purge pipe 7 is changed. And the air pressure in the box 5 also fluctuates accordingly.
The overflow water level from the lower end is always constant, and the overflow water amount is always kept constant even if the water level in the reaction tank 1 fluctuates. By adjusting the depth of submersion of the air purge pipe 7, the amount of overflowing water can be adjusted.

When the water level in the reaction tank 1 becomes lower than the lower end of the outflow hole 3, the compressed air sent into the box 5 is discharged from the air purge pipe 7 and further through the space of the outflow hole 3 to the atmosphere. Since the water is discharged into the inside, the water level in the reaction tank 1 becomes the overflow water level as it is, flows into the box 5, and the scum in the processing tank 1 is discharged by multiplying the overflow water.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a reaction tank for performing activated sludge treatment of sewage, and an outlet of treated water in the reaction tank 1 is provided on a tank wall 2 at a position slightly below a standard water level L set in the reaction tank 1. 3 have been established.

The outflow hole 3 is provided outside the tank wall 2.
Is enclosed, and a box 5 formed in a sealed shape is attached in communication with the outflow hole 3. That is, box 5
Is formed by connecting three wall plates 5a, 5a and a top plate 5b in a continuous manner, and is hermetically sealed with a shelf 4 and a tank wall 2 projecting below the outflow hole 3 outside the tank wall 2. Installed in contact.

An air supply pipe 6 communicating with a compressed air source (not shown) is provided above the box 5, for example, a top plate 4.
b, and also opened to the top plate, and the tip extended to a height near the upper end of the outflow hole 3 in the reaction tank 1, for example, to a position slightly above the upper end of the outflow hole 3. An air purge pipe 7 is provided. Box 5
A discharge pipe 8 that communicates with a sedimentation basin (not shown) protrudes into a lower part of the inside, and is provided at an end thereof as an inlet 9 so as to be opened at a position below the lower end of the outflow hole 3. . Further, a lower part of the box 5 is provided with a weir plate 10 erected at an intermediate portion between the drain pipe 8 and the tank wall 2.
The upper end of 10 extends to the lower end of the outflow hole 3 or slightly above it.

Although not shown, the box 5 may be provided with a bottom plate. In such a case, the box 5 can be attached to a portion of the tank wall 2 where the shelf 4 is not provided. In this case, the weir plate 10 is erected on the bottom plate.

FIG. 2 shows another embodiment of the device of the present invention. The difference from the previous embodiment is that the weir plate 10 is erected along the outer surface of the tank wall 2. is there. Providing the weir plate 10 as in each of the above-described embodiments is effective when the overflow water needs to be higher than the lower end of the outflow hole 3 formed in the tank wall 2. It can be easily adjusted by different heights.

FIG. 3 shows still another embodiment of the device of the present invention. In this embodiment, the tank wall 2 provided with the outflow hole 3 is also used as an overflow weir similar to the weir plate 10 without providing the weir plate 10 in each of the above embodiments. Therefore, in this case, the height of the lower end of the outflow hole 3 needs to be the same as the upper end of the weir plate 10 in the above embodiment.

The apparatus of the present invention is configured as described above, and the standard water level L in the reaction tank 1 is set at a position higher than the outflow hole 3, and the actual water level in the reaction tank 1 is determined by the amount of inflowed sewage. Fluctuates up and down with the standard water level L in the middle in accordance with the increase or decrease of. The tip of the air purge pipe 7 opens near the upper end of the outflow hole 3 which is a position near the low water level in the reaction tank 1. Then, compressed air is sent into the box 5 from the air supply pipe 6, and the water level in the box 5 is pushed down from the water level in the reaction tank 1, and excess air is discharged as bubbles from the tip of the air purge pipe 7. Become so.

Accordingly, the pressure P in the box 5 becomes equal to the water pressure at the water immersion depth h of the air purge pipe 7, and
The substantial overflow water level hw which overflows at the lower end of the outlet hole 3 (the embodiment of FIGS. 1 and 2) or the lower end of the outlet hole 3 (the embodiment of FIG. A predetermined water level is obtained by subtracting the submerged depth h of the air purge pipe 7 from H. And
The treated water that has flowed over the lower end of the weir plate or the outflow hole 3 flows into the drain pipe 8 from the intake port 9 and is sent to the sedimentation basin.

Therefore, when the water level in the reaction tank 1 fluctuates by Δh, the submergence depth h of the air purge pipe 7 also increases by Δh.
h, and the air pressure P in the box 5 also changes by the water pressure corresponding to Δh. Therefore, the overflow water level hw is always constant, and the flow rate flowing into and out of the box 5 depends on the water level fluctuation in the reaction vessel 1 as long as the water level in the reaction vessel 1 is higher than the upper end of the outflow hole 3. Will always be kept constant.

When the amount of sewage flowing into the reaction tank 1 decreases and the water level in the reaction tank 1 becomes a low water level 1 lower than the lower end of the outflow hole 3 such as at night, the air purge pipe 7 The tip is also higher than the water surface, and the air sent into the box 5 also escapes from the tip of the air purge pipe 7 and the outflow hole 3, and the air pressure in the box 5 becomes equal to the atmospheric pressure. Therefore, the height between the water level in the reaction tank 1 and the upper end of the weir plate 10 or the lower end of the outflow hole 3 becomes hw as it is, and overflows and is discharged. In such a state, the scum on the water surface of the reaction tank 1 flows out together with the overflow water, is sent to the sedimentation basin, and is collected by the scum recovery device provided in the sedimentation basin.

The above-mentioned air purge pipe 11 may have a structure in which the length in the height direction is expandable and contractable, for example, so that the depth of submersion at the lower end opening can be adjusted. This makes it possible to adjust the flow rate flowing from the overflow weir plate and to adjust the amount of effluent water.

[0020]

As described above, the pressure regulating type flow control device of the present invention is located below the standard water level of the reaction tank on the tank wall of the reaction tank, and establishes an outlet for treated water. On the outside of the tank wall, a closed box surrounding the outflow hole is provided in communication with the outflow hole, and at the top of the box, a compressed air inlet pipe and a tip near the upper end of the outflow hole of the reaction tank. A drain pipe for discharging the treated water flowing into the box to the outside of the box is provided at the lower part of the box while being connected to an air purge pipe opened at the height of the outlet opening below the lower end of the outlet hole. Therefore, even when the water level at the high water level at which the tip of the air purge pipe is submerged fluctuates during the time when the amount of inflow into the reaction tank increases, it is possible to send only a certain amount of treated water to the sedimentation basin, The load on the sedimentation basin can be reduced. Therefore, the water level of the reaction tank can be raised at the time of a large inflow to provide an adjusting tank function, and a sufficient biological treatment time can be given to improve the treatment effect.

When the water level falls below the upper end of the outflow hole at the time when the amount of inflow into the reaction tank decreases,
The scum flows into the box from the outlet and is discharged. Therefore, the reaction tank does not need to be provided with a special device for removing scum as in the related art.

In the apparatus according to the first aspect of the present invention, the provision of the weir plate makes it necessary to raise the overflow line from the lower end of the outflow hole provided in the reaction tank to adjust the height of the weir plate. There is an advantage that it can be easily performed simply by changing the size. Further, the apparatus according to claim 2 has an advantage that the weir plate can be eliminated when the overflow line does not need to be adjusted, and the apparatus can be simplified.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing another embodiment.

FIG. 3 is a longitudinal sectional view showing still another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reaction tank 2 Tank wall 3 Outflow hole 4 Shelf 5 Box 6 Compressed air supply pipe 7 Air purge pipe 8 Drain pipe 9 Intake 10 Dam plate

Claims (2)

(57) [Scope of request for utility model registration] Claims: 1. An outlet for treated water is provided in a tank wall of a reaction tank below a standard water level of the reaction tank, and the outlet of the treated water is hermetically sealed around the outlet. A box is provided in communication with the outflow hole, and a supply pipe for compressed air and an air purge pipe whose tip is opened at a height near the upper end of the outflow hole of the reaction tank are connected to the upper part of the box. A drain pipe for discharging the treated water flowing into the box to the outside of the box is provided at an opening below the lower end of the outlet hole, and a weir plate is provided between the drain pipe in the box and the tank wall. A pressure regulating type flow regulator in sewage treatment, characterized by being erected. 2. An outlet for treated water is provided on the tank wall of the reaction tank below the standard water level of the reaction tank, and the outlet of the treated water is enclosed outside the tank wall so as to surround the outlet. A box is provided in communication with the outflow hole, and a supply pipe for compressed air and an air purge pipe whose tip is opened at a height near the upper end of the outflow hole of the reaction tank are connected to the upper part of the box. And a drainage pipe for discharging treated water flowing into the box to the outside of the box. The drainage pipe is provided below the lower end of the outflow hole, and is provided.