JPS6017205Y2 - Sedimentation tank - Google Patents

Description

[Detailed description of the invention] The present invention relates to a sedimentation tank equipped with an inclined plate that can accurately sediment and remove suspended solids contained in a liquid, especially suspended solids with small particles, and improve the sedimentation processing capacity. It is something.

Conventionally, overflow water from an aerobic biological treatment tank such as activated sludge treatment flows into a final settling tank, where most of the flocs are settled and removed, but fine suspended solids are Since it is light and difficult to settle, it overflows from the settling tank along with the outflow water from the settling tank, which is a cause of poor transparency of the final precipitation treated water.

This invention effectively captures and precipitates even minute suspended substances,
The purpose is to provide a device for obtaining clear and high quality treated water.

In the present invention, a movable endless belt is provided below the liquid surface in a sedimentation tank in which a water collection mechanism is installed, and a plurality of inclined plates are arranged and equipped on the endless belt to form an inclined plate device. This sedimentation tank is characterized in that the inclined plate settling surface moves and runs in reverse, and the inclined plate promotes settling of suspended solids and the sludge that has settled and accumulated on the inclined plate can be easily transferred to the bottom of the tank. This is a new and useful sedimentation tank that is effectively equipped with an inclined plate device that also has the function of causing shedding.

An embodiment of the present invention will be described with reference to FIGS. 1 to 3. A sedimentation tank 1 has a raw water inlet 2 at one end of the upper part, and a water collection gutter 3-1 as a water collection mechanism for treated water on the other side. 3-2.3-3.
3-4.3-5.3-6, and a sludge collection pit 5 connected to the sludge pipe 4 is provided at the bottom of the raw water inlet 2 side, and an endless pipe that can be moved under the water surface. An inclined plate device 11 having a large number of inclined plates 7 fixed to a belt 6 (a driving device for the endless belt 6 is not shown) is arranged.

The inclined plate device 11 includes at least the water collection gutters 3-1 to 3-6.
It is necessary to arrange it under the water surface of the overflow area where the settling tank 1 is installed, but it may be arranged over the entire horizontal direction of the settling tank 1.

Regarding the arrangement of the inclined plate device 11 in the depth direction below the water surface, the tip of the upward inclined plate 7 is located 250 mm to 1.5 mm below the water surface.
It is preferable to position it at 000 yen.

The running direction of the endless belt 6 may be either the inclined side of the inclined plate 7 or the opposite side, and the same effect can be obtained.

The shape of the inclined plate 7 is as shown in FIG.
That is, a wide rectangle is preferable, and it is more preferable that the inclined plate 7 is arranged over the entire inner diameter of the settling tank 1 by arranging a plurality of inclined plate devices 11 or the like.

The inclination angle θ of the inclined plate 7 with respect to the endless belt 6 is such that the angle θ (not shown) of the inclined plate 7 with respect to the horizontal plane is 20 degrees to 6 degrees.
It is preferable to set the angle to 0 degrees, particularly 40 degrees to 50 degrees.

Therefore, when the inclined plate device 11 is arranged so that the endless belt 6 runs along a horizontal plane as shown in FIGS. 3a and 3b, the angle .theta.' coincides with the inclination angle .theta..

Note that the opening direction of the inclination angle θ may be the same as or opposite to the running direction of the endless belt 6, and the same effect can be obtained.

Further, a fixed point 8 of the inclined plate 7 adjacent to the tip 9 of the inclined plate 7
It is preferable that the inclined plates 7 are arranged on the endless belt 6 so that they overlap in the vertical projection view, and the effect of the present invention does not change even if the inclined plates 7 are somewhat similar to each other in projection (in the same sense as above).

In this case, each inclined plate 7 does not necessarily have to have the same inclination angle θ (that is, be parallel to each other), and may have some difference.

The type of endless belt 6 is, for example, as shown in Fig. 2, a narrow one such as a chain belt is adopted, and two or more endless belts 6-1, 6-2 are connected to the inclined plate 7 at three or more locations. It is preferable to use a type that is fixed at a fixed speed and runs at a very slow speed.

In the first illustrated example, the inclined plate device 11 is arranged so that the running direction of the endless belt 6 and the flowing direction of water in the sedimentation tank 1 are parallel to each other, but they may be arranged so that they are perpendicular to each other.

Therefore, most of the suspended solids in the raw water flowing in from the inlet 2 settle to the bottom of the sedimentation tank 1, and the sediment collector (not shown)
The sludge is collected in the sludge collecting pit 5 and drained through the sludge pipe 4.

On the other hand, suspended solids that are difficult to settle rise together with the upward flow in the overflow area, but while flowing between the sloped plates 7 of the sloped plate device 11, they come into contact with the sloped plates 7 or the suspended solids interact with each other. Upon contact, the flocs form into large flocs, which settle and accumulate on the inclined plate 7.

Generally, suspended solids such as sticky activated sludge settle on the inclined plate 7, but they are difficult to fall to the bottom of the tank, and usually accumulate on the inclined plate 7 and rot, deteriorating the quality of the treated water. However, according to the present invention, the sludge that has settled and accumulated on the inclined plate 7 is automatically and efficiently dropped to the bottom of the tank, and is discharged to the outside of the settling tank 1 together with the sludge that has already settled, thereby producing high-quality treated water. Obtainable.

That is, the sludge accumulated on the upper and lower inclined plates 7 easily falls off the plate at the vertically inverted position 10 of the endless belt 6, and since this sludge is formed into large flocs, it can efficiently settle to the bottom of the tank. Therefore, the sludge is discharged to the outside of the settling tank 1 along with the settled sludge.

Next, regarding the operating procedure of the inclined plate device 11, the endless belt 6 may be run when removing and cleaning sludge that has adhered to and accumulated on the inclined plate 7.

That is, it is desirable that the running cycle, running speed, and operating time of the endless belt 6 be set in consideration of the amount of sludge deposited, the deposition speed, and the peeling/shedding properties and sedimentation properties of the deposited sludge.

Alternatively, an automatic control device may be connected to the driving device for the endless belt 6, which sets the traveling speed to a constant value and periodically operates the endless belt 6 for a certain period of time using a timer.

Depending on the situation, the endless belt 6 may be operated at all times.

Normally, this operation cycle is set to one time, and the endless belt 6 only needs to be operated one revolution each time, and very slow operation is sufficient.

(Traveling speed varies depending on the situation).

In the first illustrated example, both the upper and lower running surfaces of the endless belt 6 are along a horizontal plane, but even if at least one of these two is along a somewhat inclined surface, This does not reduce the effectiveness of the present invention.

As described above, the present invention provides a sedimentation tank in which an inclined plate device, which has a group of inclined plates fixed to an endless belt that can run in a horizontal plane or in a direction along a substantially horizontal plane, is immersed in water in the tank. This system efficiently captures and settles suspended solids that are difficult to settle and deteriorate the treated water with conventional equipment, and can easily settle to the bottom of the tank.
The accumulated sludge can be removed and washed very easily without interrupting the sedimentation separation process, and it has practical effects such as easy maintenance and economical operation costs.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show an embodiment of the present invention, in which Fig. 1 is an overall vertical sectional view of a settling tank, Fig. 2 is a perspective view showing an example of an inclined plate device, and Fig. 3 a , b is a vertical cross-sectional view showing an example of mounting the inclined plate. 1...Sedimentation tank, 2...Inlet, 3-1
to 3-6...water collection gutter, 4...sludge removal pipe, 5...mud collection pit, 6...endless belt, 7... ... Inclined plate, 8 ... Fixed point, 9
...Top of inclined plate, 10...Reversed position,
11... Inclined plate device, θ... Inclination angle.

Claims (1)

[Claims for Utility Model Registration] 1. An inclined plate device in which a movable endless belt is provided below the liquid surface in a sedimentation tank in which a water collection mechanism is installed, and a plurality of inclined plates are arranged and arranged on the endless belt. A sedimentation tank characterized in that the sedimentation tank is configured such that the inclined plate settling surface in the tank moves and runs in reverse. 2. The endless belt is arranged to run along a horizontal plane, and the inclined plate has an inclination angle of 20 degrees to 60 degrees with respect to the endless belt in the horizontal running portion of the endless belt. The settling tank according to claim 1, which is arranged and fixed in parallel with each other. 3. The endless belt is disposed so as to run along a horizontal plane at least below the liquid level in the overflow area where the water collecting mechanism is installed, and the tip of the upwardly facing inclined plate is below the liquid level. The settling tank according to claim 1 or 2, which is disposed at a distance of 250 rIvIL to 1000 mm below. 4. Utility model registration according to claim 1, 2, or 3, wherein the inclined plate overlaps an adjacent inclined plate in at least a part of the projected view perpendicular to the endless belt. Sedimentation tank.