JPH07275610A - Precipitation filtration method and apparatus therefor - Google Patents

Abstract

PURPOSE:To save the space and shorten the treatment time by carrying out discharge and filtration of muddy sludge simultaneously. CONSTITUTION:This recipitation and filtration method involves introducing raw water 3 into a precipitation tank 2 and precipitating muddy substances contained in the raw water along tilting upper faces of tilting plates 1 while filtering them by a flat membrane 4 set in the lower faces of the tilting plates, and the recipitation and filtration apparatus is composed by installing the tilting plates 1 to accelerate the precipitation of the muddy substances in the precipitation tank 2 and installing the flat membrane 4 in the tilting lower faces of the tilting plates in the way a space to take in the permeating water is formed and installing a water sending apparatus 8 to send the permeating water in the tilting plates to the outside of the precipitation tank 2. Also, an air jetting pipe 10 to supply air to remove muddy substances adhering to the surface of the flat membrane 4 of the tilting plates 1 is installed in the precipitation tank and air is continuously or intermittently jetted from the lower side to the surface of the flat membrane of the tilting plates.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sedimentation filtration method and apparatus for precipitating suspended matter in raw water introduced into a sedimentation tank by an inclined plate and filtering the sedimentation.

[0002]

2. Description of the Related Art Generally, as a method for removing solid matters or turbidity such as flocs contained in raw water, there are precipitation and filtration, and in water purification facilities, raw water such as river water and lake water is deposited. The water is introduced from the water well to the filtration basin through the coagulation / sedimentation basin to perform sedimentation filtration, and when advanced treatment is required, purification treatment is carried out via an ozone treatment tank or an activated carbon treatment tank.

In order to promote gravity settling of suspended solids, most of the sedimentation tanks are equipped with inclined plate sedimentation equipment in which a large number of inclined plates are arranged side by side in the width direction of the sedimentation tank. Further, as the filter basin, sand filtration using sand is generally used, and this filtration includes slow filtration and rapid filtration.

[0004]

However, this conventional technique has the following problems. After removing suspended solids from the raw water in the settling tank, the raw water is filtered in the next step, the filter tank. Therefore, the sedimentation basin and the filtration basin are installed separately, and in particular, since these occupy a large amount of installation space in each water purification facility, the ratio of the area occupied by both is 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 process is performed after the precipitation process, it takes a long processing time.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art, 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-mentioned object, the present invention introduces raw water into a settling tank and removes suspended matter contained in the raw water along the inclined upper surface of a sloping plate. A settling filtration method is characterized in that a settling filtration is carried out by a flat membrane provided on the inclined lower surface of the slanting plate while settling. In this case, it is effective to jet air continuously or intermittently from below onto the surface of the flat film of the inclined plate. Further, according to the present invention, an inclined plate that promotes sedimentation of suspended matter is provided in the settling tank, and a flat membrane is provided on the inclined lower surface of the inclined plate so that a space portion for taking in permeated water is formed inside. A settling filter is provided, which is provided with a water feeder for sending permeated water in the inclined plate to the outside of the settling tank. In this case, it is effective to provide an air jet pipe for supplying air for removing suspended matter adhering to the surface of the flat plate of the inclined plate in the settling tank.

On the other hand, according to the present invention, raw water is introduced into a settling tank, and suspended solids contained in the raw water are allowed to settle along the inclined plate while being filtered by flat membranes provided on both sides of the inclined plate. A precipitation filtration method characterized in that In this case, it is effective to jet air or water continuously or intermittently onto the flat film of the inclined plate. Further, the present invention is
A slanting plate that promotes sedimentation of suspended solids is provided in the settling tank, and a flat membrane is provided on both sides of this slanting plate so that a space for taking in permeated water is formed inside the slanting plate. A settling filter was constructed, which was provided with a water feeder for sending water to the outside of the settling tank. In this case, it is effective to provide an air jet pipe or a water jet pipe for supplying air or water for removing suspended matter adhering to the surface of the flat plate 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 is deposited on the bottom of the settling tank. Further, the raw water is filtered by the 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 air jetted from the air jet pipe separates the suspended matter adhered to the flat film of the inclined plate, and the separated suspended matter precipitates.

On the other hand, according to another embodiment of the present invention, suspended solids in the raw water descend along the flat membrane on the upper surface side of the inclined plate and settle on the bottom of the settling tank. Further, the raw water is filtered by flat membranes provided on both sides of the inclined plate, and the filtered permeated water is sent to the outside of the settling tank by the water feeder. Further, air or water ejected from the air ejection pipe or the water ejection pipe separates the suspended matter attached to the flat film of the inclined plate, and the separated suspended matter precipitates.

[0010]

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 precipitation filtration apparatus embodying the present invention, FIG. 2 is a front sectional view of the apparatus, FIG. 3 is a side sectional view of the apparatus, and FIG. 4 is a sectional view of an inclined plate.

In FIGS. 1 to 4, a predetermined number of inclined plates 1 are laterally arranged in a settling tank 2. A distribution tank 20 is provided on one side of the precipitation tank 2, and the raw water 3 is introduced into the precipitation tank 2 from the distribution tank 20 via a straightening plate 9. The straightening vane 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 in the settling tank 2.

As shown in FIG. 4, the inclined plate 1 has a plate body 1a having a side edge and having an opening on one side, and a flat plate provided on the inclined lower surface which is the opening via a support member 4a. It is composed of the film 4 and forms a space 5 therein. Plate 1a
Is made of a material such as PVC and has the function of promoting the sedimentation of the suspended matter 6 in the raw water 3. Further, the flat membrane 4 is an MF membrane, U
An F membrane, an RO membrane, or a mesh-like body having an appropriate mesh is used to allow the raw water 3 to permeate therethrough, 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 permeated the water 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 puts these together, and a water feeder 8 that includes a pump 13 or a vacuum device, etc. Water is sent to the outside of 2. It is preferable that the distance Y between the adjacent inclined plates 1 can be adjusted to an arbitrary length. Further, if the inclined plate 1 can be adjusted to an arbitrary angle, the optimum settling speed of the precipitate formed by the coagulant or the like can be selected.

An air jet pipe 10 is arranged below the inclined plates 1 in the settling tank 2. Air jet pipe 1
0 is supplied with air from an air supply device 15 such as a compressor, 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 washed by so-called air scrubbing. . Air 10
It is preferable that a is ejected continuously, but it 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 body 1 that is the inclined upper surface of the inclined plate 1.
descend the surface of a. The settled suspended matter 6 opens the valve body 17 when a predetermined amount or a predetermined time is reached, and is sent to the side of the sludge discharge unit 18 where it is processed in the 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. Slanted plate 1 through flat film 4
The permeated water 7 that has entered the space 5 of the
Water is sent to the outside of the settling tank 2 via 1, 12. Also,
The suspended matter 6 '(FIG. 4) adhering to the surface of the flat membrane 4 is separated and removed by the air 10a rising from the air ejection tube 10, and descends to be discharged together with the sedimented suspended matter 6. The air ejection pipe 10 is connected to the air supply device 15 and ejects compressed air onto the surface of the flat film 4 of each inclined plate 1,
By appropriately setting the direction of the jet, the suspended matter 6 '
Efficiently removed.

Next, another embodiment of the present invention will be described. The basic configuration of the precipitation filtration apparatus shown in FIGS. 1 to 3 is the same as that of the above-mentioned embodiment, and therefore, the same parts are designated by the same reference numerals and the description thereof will be omitted.

FIG. 5 is a sectional view of an inclined plate used in the precipitation filtration device of this embodiment. The inclined plate 1 ′ has flat films 4 and 4 formed on both sides of the support materials 4 a and 4 a with a space 5 provided therein. The flat film 4 is an MF film, a UF film,
The raw water 3 is made to pass through both sides of the inclined plate 1 and is made of an RO membrane or a mesh of an appropriate mesh, and the permeated water 7 is taken into the space 5.

An air jet pipe or a water jet pipe 10 'is disposed below each inclined plate 1'in the settling tank 2 shown in FIGS. Air jet pipe or water jet pipe 1
0'is supplied with air or water from an air or water supply unit 15 ', and air or water 10a' is jetted from below between adjacent inclined plates 1 ', and is provided on both sides of the inclined plate 1'. The surfaces of the flat membranes 4 and 4 are washed. The air or water 10a 'may be jetted continuously, but may be jetted intermittently if there is no difference in cleaning efficiency. 10b '
Is an air or water nozzle or hole.

Next, the operation of this embodiment will be described.
The turbidity 6 in the raw water 3 is the flat film 4 on the inclined upper surface side of the inclined plate 1 '.
Down the surface of. The settled suspended matter 6 opens the valve body 17 when a predetermined amount or a predetermined time is reached, and is sent to the side of the sludge discharge unit 18 where it is processed in the subsequent steps.

On the other hand, the raw water 3 is filtered by the flat membranes 4 and 4 provided on both sides of the inclined plate 1 '. The permeated water 7 that has passed through the flat membranes 4 and 4 and has entered the space 5 of the inclined plate 1 ′ is sent to the outside of the settling tank 2 by the water feeder 8 via the pipes 11 and 12.
In addition, suspended matter 6'attached to the surfaces of the flat membranes 4 and 4 (Fig. 5)
Is separated and removed by the air or water 10a 'rising from the jet pipe 10' of air or water between the adjacent inclined plates 1 ', and is descended and discharged together with the sedimented suspended matter 6. The air or water jet pipe 10 'is connected to an air or water supplier 15' to jet air or water onto the surfaces of the flat membranes 4 and 4 of each inclined plate 1 ', and to direct the jet port direction. By properly setting, the suspended matter 6'can be efficiently removed.

The air or water 10a 'is supplied to each inclined plate 1'.
Suspended matter supplied from an air or water jet pipe 10 'disposed immediately below the ridge and rising between adjacent inclined plates 1'and adhered to the surfaces of the flat membranes 4 and 4 by the air or water 10a'. 6'is removed by peeling, but when the distance between adjacent inclined plates 1'is large, it is effective to eject from the entire area below each inclined plate 1 '. When jetting water, a water flow may be generated horizontally or vertically from the lateral direction or the upward direction of the settling tank 2.

The present invention is not limited to the above embodiment, and for example, each inclined plate 1 (1 ') may be fixedly supported by the side wall of the settling tank 2, and in this case, inside the side wall. A permeated water channel may be provided in the.

[0024]

As described above, the present invention introduces raw water into the settling tank and causes the suspended matter contained in the raw water to settle along the inclined upper surface of the inclined plate while Since the flat membrane provided on the inclined lower surface is used for filtration, it is possible to simultaneously perform the sludge discharge and the filtration, so that the space can be saved and the processing time can be shortened.
Further, by blowing air from below onto the surface of the flat plate of the inclined plate, the suspended matter attached to the surface of the flat plate can be efficiently removed.

Further, the raw water is introduced into the settling tank, and the suspended matter contained in the raw water is allowed to settle along the inclined plate while being filtered by the flat membranes provided on both sides of the inclined plate. In the case of the above, even if turbidity is attached to the upper surface side of the slope and it tends to be more difficult to filter, the turbidity will be removed by the water flow by stirring with air. Therefore, both sides of the inclined plate can be filtered, and as a result, the membrane area can be increased, that is, the throughput can be increased.

[Brief description of 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 cross-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 the precipitation filtration device embodying the present invention.

FIG. 5 is a cross-sectional view of another example of the inclined plate used in the precipitation filtration device embodying the present invention.

[Explanation of symbols]

 1, 1 ': Inclined plate 2: Settling tank 3: Raw water 4: Flat membrane 5: Space part 6: Suspended water 7: Permeate water 8: Water transmitter 9: Rectifier plate 10: Air jet pipe 10': Air or water Jet pipe 10a: Air 10a ': Air or water 10b: Air nozzle or hole 10b': Air or water nozzle or hole 11: Piping 12: Piping 13: Pump 15: Air supplier 15 ': Air or water supplier 17: Valve body 18: Sludge removal part 20: Distribution tank

Claims (8)

[Claims] 1. Raw water is introduced into a settling tank, and suspended solids contained in the raw water are settled along an upper surface of an inclined plate and filtered by a flat membrane provided on an inclined lower surface of the inclined plate. A precipitation filtration method comprising: 2. The turbidity attached to the flat film is removed by continuously or intermittently ejecting air onto the surface of the flat film of the inclined plate from below. Precipitation filtration method. 3. A slanting plate that promotes sedimentation of suspended matter is provided in the settling tank, and a flat membrane is provided on the slanted lower surface of this slanting plate so that a space portion for taking in permeated water is formed inside, A precipitation filtration device comprising a water supply device for supplying permeated water in the inclined plate to the outside of the precipitation tank. 4. The settling apparatus according to claim 3, wherein the settling tank is provided with an air jetting pipe for supplying air for removing suspended matter adhering to the surface of the flat plate of the inclined plate. Filtration device. 5. Raw water is introduced into a settling tank, and suspended solids contained in the raw water are allowed to settle along the inclined plate while being filtered by flat membranes provided on both sides of the inclined plate. And a precipitation filtration method. 6. The settling filtration according to claim 5, wherein air or water is continuously or intermittently jetted to the flat plate of the inclined plate to remove suspended matter adhering to the flat plate. Method. 7. A slanting plate for promoting sedimentation of suspended matter is provided in the settling tank, and a flat membrane is provided on both sides of this slanting plate so that a space portion for taking in permeated water is formed inside.
A precipitation filtration device comprising a water supply device for supplying permeated water in the inclined plate to the outside of the precipitation tank. 8. An air jet pipe or a water jet pipe for supplying air or water for removing suspended matter adhering to the surface of the flat plate of the inclined plate is provided in the settling tank. Item 7. The precipitation filtration device according to item 7.