JP3303267B2 - Precipitation filtration method and apparatus therefor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for sedimentation filtration in which turbidity in raw water introduced into a sedimentation tank is settled on an inclined plate and filtered.

[0002]

2. Description of the Related Art Generally, methods for removing solids or turbid substances such as flocs contained in raw water include sedimentation and filtration. In a water purification facility, raw water such as river water or lake water is deposited. The water is introduced from a well into a filtration pond via a coagulation / sedimentation pond, and is subjected to sedimentation filtration. When advanced treatment is required, purification treatment is performed through an ozone treatment tank or an activated carbon treatment tank.

In order to promote gravitational settling of turbidity, the sedimentation basin is often provided with an inclined plate sedimentation facility in which a number of inclined plates are juxtaposed in the width direction of the sedimentation basin. Sand filtration using sand is generally used as a filtration pond. This filtration includes slow filtration and rapid filtration.

[0004]

However, according to the prior art, there are the following problems. After removing turbidity in the sedimentation basin, the raw water is filtered in the next step, the filtration pond. Therefore, the sedimentation basin and the filtration basin are separately installed, respectively. In particular, since these take up a lot of installation space among the water purification facilities, the ratio of the area occupied by both becomes considerably large. Thus, the processing capacity is determined by the installation area of the equipment, and the processing capacity cannot be increased in a small space. Further, since the filtration treatment is performed after the precipitation treatment, it takes a long processing time.

[0005] It is an object of the present invention to solve the above-mentioned problems of the prior art, and to provide a precipitation filtration method and apparatus capable of reducing the space and shortening the processing time.

[0006]

In order to achieve the above object, the present invention introduces raw water into a sedimentation tank, and converts turbidity contained in the raw water along the inclined upper surface of the inclined plate. While settling, filtration is performed by a flat membrane provided on the inclined lower surface of the inclined plate, and transmitted through a space formed inside the inclined plate and the flat membrane.
A precipitate filtered method for extracting water outside, the settling tank
A predetermined number of inclined plates are installed in a single stage in the horizontal direction, and air is continuously or intermittently blown from below onto the surface of the flat film of the inclined plate to remove turbidity adhered to the flat film. And a precipitation filtration method characterized by the following. In this case, it is effective to blow air continuously or intermittently from below onto the surface of the flat film of the inclined plate.

Further, according to the present invention, a predetermined number of inclined plates for accelerating sedimentation of a turbid substance are provided in a single stage in a lateral direction in a sedimentation tank.
A flat membrane is provided on the inclined lower surface of each inclined plate so as to form a space for taking in permeated water therein, and a water feeder for sending permeated water in each inclined plate to the outside of the sedimentation tank is provided, and A sedimentation filtration device was provided in which an air ejection pipe for supplying air for removing suspended matter adhered to the surface of the flat membrane of each inclined plate was provided in the tank. In this case, it is effective to provide an air ejection pipe for supplying air for removing suspended matter adhered to the surface of the flat film of the inclined plate in the settling tank.

[0008]

According to the embodiment of the present invention, the suspended matter in the raw water descends along the inclined upper surface of the inclined plate and settles at the bottom in the sedimentation tank. Also, the raw water is filtered by a flat membrane provided on the inclined lower surface of the inclined plate, and the filtered permeated water is sent to the outside of the settling tank by the water feeder. Further, the turbidity adhered to the flat film of the inclined plate is peeled off by the air blasted from the air blast pipe, and the turbidity thus separated is precipitated.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a schematic configuration of a sedimentation filtration apparatus embodying the present invention, FIG. 2 is a front sectional view of the same apparatus, FIG. 3 is a side sectional view of the same apparatus, and FIG. 4 is a sectional view of an inclined plate.

In FIG. 1 to FIG. 4, a predetermined number of inclined plates 1 are arranged in a sedimentation tank 2 in a lateral direction. A distribution tank 20 is provided on one side of the sedimentation tank 2, and the raw water 3 is introduced from the distribution tank 20 into the sedimentation tank 2 via the rectifying plate 9. The current plate 9 has a large number of holes 9a formed in the up, down, left, and right directions, so that the raw water 3 fed to the distribution tank 20 flows evenly into the settling tank 2.

As shown in FIG. 4, the inclined plate 1 has a plate 1a having a side edge and an opening on one side, and a flat plate 1a provided on the inclined lower surface, which is the opening, via a supporting member 4a. And a space 4 formed therein. Plate 1a
Is made of a material such as PVC and functions to promote the sedimentation of the turbid matter 6 in the raw water 3. The flat film 4 is composed of an MF film, U
It is made of an F film, an RO film, or a mesh material of an appropriate mesh. The raw water 3 is permeated, and the permeated water 7 is taken into the space 5.

Referring also to FIGS. 1 to 3, the flat membrane 4
The permeated water 7 that has passed through is collected by a pipe 11 such as a flexible tube that communicates with the space 5 of each inclined plate 1, a pipe 12 that collects these, and a water transmitter 8 that includes a pump 13 or a vacuum device, and is collected by a sedimentation tank. 2 is sent to the outside. It is preferable that the distance Y between the adjacent inclined plates 1 can be adjusted to an arbitrary length. In addition, if the inclined plate 1 can be adjusted to an arbitrary angle, an optimum sedimentation speed of a precipitate formed by a coagulant or the like can be selected.

An air jet pipe 10 is provided below the inclined plate 1 in the settling tank 2. Air jet tube 1
Air is supplied from the air supply device 15 such as a compressor to the lower surface, and air 10a is jetted from below onto the inclined lower surface of the inclined body 1, that is, the surface of the flat film 4, and the surface of the flat film 4 is cleaned by so-called air scrubbing. . Air 10
a may be ejected continuously, but may be ejected intermittently if there is no difference in cleaning efficiency. 10b is an air nozzle or a hole.

Next, the operation of this embodiment will be described.
The turbidity 6 in the raw water 3 is the plate 1 which is the inclined upper surface of the inclined plate 1.
descend the surface of a. When the settled turbidity 6 reaches a predetermined amount or a predetermined time, the valve body 17 is opened, sent to the sludge discharging section 18 side, and processed in the next and subsequent steps.

On the other hand, the raw water 3 is filtered by the flat membrane 4 formed on the inclined lower surface of the inclined plate 1. The inclined plate 1 penetrating the flat membrane 4
The permeated water 7 that has entered the space 5 of
Water is sent to the outside of the sedimentation tank 2 via 1 and 12. Also,
The suspended matter 6 ′ (FIG. 4) attached to the surface of the flat membrane 4 is separated and removed by the air 10 a rising from the air ejection pipe 10, descends and is discharged together with the settled suspended matter 6. The air ejection pipe 10 is connected to an air supply device 15 and ejects compressed air to the surface of the flat film 4 of each inclined plate 1.
By appropriately setting the direction of the jet port, the suspended matter 6 '
Is efficiently removed.

The air or water 10a is supplied from an air or water jet pipe 10 disposed immediately below each inclined plate 1, and rises between adjacent inclined plates 1 to be flattened by the air or water 10a. The suspended matter 6 adhering to the surface of the plate 4 is peeled off, but when the distance between the adjacent inclined plates 1 is large, it is effective to eject the suspended particles 6 from the whole area under each inclined plate 1. When water is jetted, a water flow may be generated horizontally or vertically from the lateral direction or the upper direction of the sedimentation tank 2.

The present invention is not limited to the above embodiment. For example, each inclined plate 1 may be fixedly supported by the side wall of the sedimentation tank 2, and in this case, the permeated water is contained in the side wall. What is necessary is just to provide a flow path.

[0018]

According to the present invention, as described above, raw water is introduced into a sedimentation tank, and turbidity contained in the raw water is settled along the inclined upper surface of the inclined plate. Since the filter is configured to be filtered by the flat membrane provided on the inclined lower surface, the muddy mud and the filtration can be performed simultaneously, so that the space can be saved and the processing time can be shortened.
By ejecting air from below onto the surface of the flat film of the inclined plate, turbidity adhered to the surface of the flat film can be efficiently removed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic configuration of a precipitation filtration device embodying the present invention.

FIG. 2 is a front sectional view showing a schematic configuration of a precipitation filtration device embodying the present invention.

FIG. 3 is a side sectional view showing a schematic configuration of a precipitation filtration device embodying the present invention.

FIG. 4 is a cross-sectional view of an inclined plate used in a precipitation filtration device embodying the present invention.

[Explanation of symbols]

1: inclined plate 2: sedimentation tank 3: raw water 4: flat membrane 5: space 6: turbidity 7: permeated water 8: water transmitter 9: rectifying plate 10: air ejection pipe 10 a: air or water 10 b: air nozzle or Hole 11: Piping 12: Piping 13: Pump 15: Air supply unit 17: Valve body 18: Drainage unit 20: Distribution tank

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B01D 21/00-21/34 B01D 61/00-71/82 C02F 1/44

Claims (2)

(57) [Claims] 1. Raw water is introduced into a sedimentation tank, and while suspended in the raw water is settled along the inclined upper surface of the inclined plate, filtration is performed by a flat membrane provided on the inclined lower surface of the inclined plate.
And permeate water from the space formed inside the inclined plate and the flat membrane.
A predetermined number of inclined plates are installed in a horizontal direction in a single stage in a sedimentation tank, and air is continuously or intermittently applied to the surface of the flat membrane of the inclined plate from below. A sedimentation filtration method, comprising removing turbid matter that has been ejected and adhered to the flat membrane. 2. A predetermined number which promotes sedimentation of suspended matter in a sedimentation tank.
The inclined plate is provided in a single stage in the horizontal direction, and a flat membrane is provided on the inclined lower surface of each inclined plate so that a space for taking in the permeated water is formed therein, and the permeated water in each inclined plate is settled. In addition to providing a water feeder for feeding water outside the tank, an air jet pipe for supplying air for removing suspended matter adhered to the surface of the flat membrane of each inclined plate is provided in the settling tank. Settling filtration device.