JPS588387Y2 - Sedimentation tank sludge extraction equipment - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a sludge extraction device for a settling tank.

For sewage treatment equipment, sewage that has been treated with organic matter using activated sludge in an aeration tank is sent to a final settling tank, where it is separated into sludge and clear water, and the sludge settles at the bottom of the settling tank.

This settled sludge is extracted from the settling tank, and most of it is returned to the aeration tank for reuse.

In Fig. 1, 1 is a sedimentation tank, 2 is a sludge pool provided at one end of the bottom of the sedimentation tank 1, and the sludge settled on the bottom surface 1a of the sedimentation tank is collected by a sludge scraper (not shown). 2
are collected in.

A sludge tank 3 is provided adjacent to the settling tank 1 via a partition wall 8, and the sludge stored in the sludge reservoir 2 is taken out to the sludge tank 3 by a sludge extraction device 5.

4 is a pump that sends the sludge in the sludge tank 3 to the aeration tank, and there is also a pump (not shown) that sends excess sludge to the sludge thickener.

By the way, the conventional sludge drawing device 5 has one end opened into the sludge tank 2, the other end of the drawing pipe 6 guided into the sludge tank 3 and extended upward, and a telescope valve T provided at the other end. The upper end of the movable tube body 7a is connected to the liquid level 9 of the settling tank 1.
The sludge in the sludge tank 2 is drawn into the sludge tank 3 by the difference in water level created by locating it further down.

However, the amount of sludge sent by the pump 4 needs to be changed in response to the constantly changing amount of sewage, and accordingly, the amount of sludge extracted by the sludge extraction device 5 also needs to follow the change in the amount of sludge sent. Some telescope valves 7 cannot be adjusted manually, and therefore the amount of mud fed by the pump 4 may not be able to correspond to the amount of sewage.

The present invention solves these conventional drawbacks and provides a sludge extraction device that can automatically pull out an amount of sludge equal to the amount of sludge sent by the pump from the settling tank into the sludge tank, and also allows easy cleaning of the device. For the purpose of providing.

The embodiment will be described below with reference to FIGS. 2 and 3.

In FIG. 2, 11 is a drawn pipe, one end of which 11
A opens into the sludge sump 2 at the bottom of the settling tank 1, passes through the partition wall 8, is guided into the sludge tank 3, and extends upward in the vertical direction, and the other end 11b opens into the sludge tank 2 at the liquid level 28 of the sludge tank 3. It protrudes upward and has an opening.

12 is a space 26 above the other end of the drawn pipe 11 and the outer periphery of the other end.
A cylindrical body with a closed top end that covers the body in an open and sealed state,
Its cross-sectional shape is square.

In FIG. 3, the cylindrical body 12 has an opposite side wall 15.16 extending from the opposite side piece 13.14, and an inclined bottom plate 11 connected to the lower edge of the side wall 15.16 and the lower edge of the cylindrical body 12. The bottom plate 1 is provided along the vertical edge of the side wall 15.16.
A side plate 18 reaching 7 is provided and an overflow passage 19 is formed.

This passage 19 communicates with an opening 20 provided between side walls 15916 at the lower end of the cylindrical body 12.

The side plate 18 is loosely fitted between the guide rails 21 and 22 and can be pulled out upward, and is configured as a so-called corner-drop weir plate.

One end of a tube 25 passes through the upper end plate 24 of the cylindrical body 12 and communicates with the space 26 inside the cylindrical body 12, and one end of the tube 21 is immersed in the liquid level 28 for a predetermined length, so that both of these are connected. tube 25.27
The other end is connected to a pipe 29 connected to a pneumatic supply source (not shown).

Next, the effect will be explained.

It is now assumed that the other end 11b of the drawn pipe is below the liquid level 9 of the settling tank 1 and that the difference in height is rated as Ho.

It happens that the difference in height between one end of the pipe 27 and the liquid level 28 of the sludge tank 3 is H1, Hl is smaller than H8 by h, and
9 is supplied with air at a pressure p suitably higher than the head pressure of H1, then the pressure inside the pipe 21 is the pressure p corresponding to the head H1.

The pressure in the space 26 inside the cylindrical body 12, which communicates with this pipe 27 via the pipe 25, is also Pl.

Thus, the sludge in the sludge pool 2 is P corresponding to the head H8.

The pressure difference between the pressure P1 and the pressure P1 causes the liquid to be discharged from the other end 11b of the drawn pipe.

Since the lower end of the cylindrical body 12 is closed, the sludge discharged into the cylindrical body 12 once accumulates inside the cylindrical body 12 and is then removed from the cylindrical body 1.
Due to the pressure P1 in the space 26 in the sludge tank 2, the sludge flows from the lower end opening 20 through the overflow passage 19 and overflows from the upper end opening 30 thereof and enters the sludge tank 3.

Here, if there is no overflow passage 19, the sludge will be discharged directly downward into the sludge tank 3 from the lower end opening 20 of the cylindrical body 12 below the liquid level 28.

If this is done, the state of the discharged sludge cannot be visually observed at all, resulting in inconveniences such as the inability to observe the color of the sludge to determine the properties of the sludge9 or the amount of sludge discharged.

Therefore, the overflow passage 19 solves this problem.

By the way, the head of the discharged sludge, that is, the other end of the drawing pipe 11b
The difference in height between and the discharge liquid level can be given by H8-Hl and is proportional to the amount of sludge drawn from the sludge reservoir 2.

Next, from this state, the amount of mud fed by the pump 4 increases and the liquid level 2
If 8 falls, Hl becomes smaller, so H6-Hl
, that is, as h increases, the amount of sludge extracted increases, but when the amount of sludge sent by the pump 4 partially decreases and the liquid level 28 rises, Hl increases, so h decreases, and the amount of sludge extracted decreases. However, when Hl reaches H8, the extraction stops.

In this way, even if the amount of sludge fed by the pump 4 changes, the liquid level 28 is maintained substantially constant until the sludge is drawn into the sludge tank 3 according to the amount of sludge fed.

If the overflow passage 19 or the cylindrical body 12 is clogged with cased sludge and you want to clean it, you can easily clean it by pulling up the side plate 18 and removing it.

Furthermore, when the side plate 18 is removed, the valve 31 is closed and the pipe 2 is closed.
By opening the tip valve 34 of the branch pipe 25a of No. 5 and releasing the inside of the cylindrical body 12 to atmospheric pressure, the sludge is discharged vigorously with a large pressure difference Po. The cylindrical body 12 can be cleaned together with cleaning.

According to the present invention, as is clear from the above description, the sludge in the settling tank is always drawn out so as to keep the liquid level in the sludge tank constant regardless of changes in the amount of sludge fed by the pump.

That is, an amount of sludge equal to the amount of sludge sent can be automatically drawn from the silt tank to the sludge tank.

Furthermore, at least a part of the side wall of the overflow passage of the sludge extraction device is constructed with a removable side plate, and when cleaning the sludge extraction device, this side plate can be removed. It can be done effectively.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing the overall configuration of a settling tank together with a conventional sludge extraction device, Fig. 2 is a sectional view showing an embodiment of the present invention, and Fig. 3 is a plan view of the cylindrical body in Fig. 2. . 1...Sedimentation tank, 2...Sludge tank, 3...
...Sludge tank, 4...Pump, 11...
...drawn pipe, 12...tubular body, 15.16...
...Side wall, 18...Side plate, 19...
・Overflow passage, 20...Opening, 21.22...
...Guide, 25.27.29...Tube, 30
...Opening, 31-34...Valve.

Claims (1)

[Scope of utility model registration request] A cylindrical shape whose top end is closed, with one end opening at the bottom of the sedimentation tank, the other end of the drawn pipe being guided into the sludge tank, the other end extending upward, and covering the upper and outer periphery of the other end of the drawn pipe with a space left. an overflow passage having an upper end opening communicating with the lower end opening of the cylindrical body and extending upward; and at least a part of the wall forming the passage being removable from the upper end to the lower end. The other end of a pipe formed of a side plate, one end of which communicates with the space inside the cylindrical body, and the other end of a pipe whose one end is immersed in the liquid level of the sludge tank are communicated with each other and connected to a common fluid supply source. A sludge extraction device for a settling tank characterized by: