JPH10230106A - Method and device for washing fibrous filter medium in filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfactorily and efficiently perform washing of fibrous filter media in a filter in which a filtration layer is constituted of the fibrous filter media. SOLUTION: The inside of a filter tank 11 is partitioned into a middle part region 13 in which a filtration layer is formed and into the upper and lower regions 14, 15 by both a perforated plate 41 supporting the filtration layer consisting of fibrous media 3a and a perforated plate 8 arranged in its upper part. A part 17b of washing water 17 is circulated and supplied from the upper region 14 to the lower region 15 through a circulation path 18 and a booster pump 19 while forming a horizontal spiral flow along the inner peripheral face of the filter tank 11 . Simultaneously, cleaning air 22 is convergently spouted from the partition part 15a of the lower region 15 to the region part 13a of the middle part in the just above direction. In the region 13 of the middle part, a strong ascending current 17e is formed in the region part 13a of the middle part by air lift effect and thereby the filtration layer is rapidly disentangled and also circulation currents 17f due to difference in density are formed in the intervals of the region parts 13b of other middle parts. The fibrous filter media 3a are mixed and agitated uniformly and sufficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter device preferably used in swimming pools, scenic ponds, hot springs, etc., and in particular, a block-like fibrous filter medium laminated on a porous filter medium support plate. By supporting, in a filtration device that forms a filtration layer through which water to be treated descends in the filtration tank, when the filtration operation time reaches a certain time or when the filtration loss head reaches a certain value, The present invention relates to a method for cleaning a fibrous filter medium to recover and maintain a filtration function, and an apparatus for performing the method.

[0002]

2. Description of the Related Art Conventionally, as a filtration apparatus, a sand layer is formed in a filtration tank and the water to be treated is allowed to pass downward so that pollutants, that is, fine solid substances, in the water to be treated are removed from the surface layer of the sand layer. There is a known sand filtration device that is configured to trap and remove the pollutants at the surface, but since the pollutants are trapped only at the surface layer of the sand layer as the filtration layer, the disadvantage is that the filtration tank is necessarily enlarged. There is a problem that a large amount of clean water is required for washing (backwashing) for recovering the filtration function. That is, in order to loosen and remove the sand and the trapped substance in the surface layer of the sand layer, about 5% of the filtered water is required for the washing water, and the washing water penetrates into the sand layer. It was necessary to use clean water that did not contain it.

[0003] In recent years, there has been proposed a filtering apparatus in which a massive fibrous filter medium is laminated and supported on a porous filter medium support plate to form a filtration layer through which water to be treated passes downward in a filtration tank. Proposed. That is, such a filtration device can achieve a reduction in size of the filtration tank because the filtration function is exerted on the entire surface of the filtration layer, and can realize high-speed filtration due to low filtration resistance, thereby improving filtration efficiency. And so on, which exhibit an extremely excellent filtration function. Also, since the fibrous filter medium is of a very low specific gravity,
Mixing and stirring are easily performed by aeration in the washing water, so that simple and effective washing of the filter medium can be performed. Furthermore, even if slightly polluted water is used, as long as the fibrous filter medium is uniformly mixed and stirred, there is no problem in terms of the cleaning effect, so that the water to be treated can be used as the cleaning water. .

[0004]

By the way, in the sand filtration device, the filter medium needs to be intensively washed only on the surface layer of the sand layer, and it is not necessary to mix the filter material constituting the sand layer over the entire surface. Although filtration can be performed only by expansion, in a filtration device using a fibrous filter medium, pollutants are trapped on the entire surface from the surface layer to the bottom layer of the filter layer. It is necessary to mix and stir uniformly and sufficiently in water. However, when the entire surface of the filtration layer area is blown with cleaning air, the apparent specific gravity of the cleaning water decreases if bubbles are filled in the cleaning water. Nevertheless, instead of rising in the washing water, it will sink down. Therefore, the mixing and stirring of the fibrous filter media are not sufficiently performed, and the amount of washing water cannot be reduced.

[0005] Therefore, when washing the fibrous filter medium, it is preferable to concentrate and aerate a part of the filter layer region. In other words, when such local aeration is performed, a density difference occurs between the aerated area portion and the non-aerated area portion, and as a result, the circulation flow of the washing water rising in the aerated area portion and descending in the non-aerated area portion. Is formed, and the fibrous filter medium can be forcedly circulated between the two regions.
Therefore, the mixing and stirring of the fibrous filter medium is sufficiently performed, the trapped pollutants are easily peeled off, and the amount of washing water can be reduced. The present inventors have confirmed that the amount of washing water can be reduced to about 1% of the amount of filtered water.

However, since the fibrous filter medium is rich in elasticity, the degree of compression increases in proportion to the filtration speed. That is, as the filtration rate increases, the degree of consolidation of the filtration layer also increases, and is particularly remarkable in the bottom part of the filtration layer. Such consolidation by the velocity head of the filtration layer
Specifically, it becomes remarkable when the filtration speed exceeds 30 m / h, and when the filtration speed is about 100 m / h to 120 m / h, the volume of the filtration layer is firmly consolidated to about 1/3.

[0007] Therefore, in the state where the filtration layer is compacted in this way, the above is combined with the fact that the bottom layer portion is further compacted and that the filter media are adhered to each other by trapped pollutants. It is not easy to loosen the filter layer by local aeration or the formation of a circulating flow thereby, and it is not possible to carry out efficient filter medium washing. In other words, depending on the local aeration, good cleaning can be performed after the filtration layer is loosened, but it takes a considerable time to loosen the filtration layer. The present inventor has confirmed that it takes at least about 5 minutes for the compacted filter layer to be loosened not only in the case of full aeration but also in the case of local aeration.

[0008] In view of the above, the present invention provides high-speed filtration conditions (30 m / m) in which the filtration layer is extremely compacted.
h), the filter layer can be quickly loosened, and the mixing and stirring of the fibrous filter medium can be performed uniformly and sufficiently, and the fibrous filter medium can be washed well and efficiently. It is an object of the present invention to provide a cleaning device for suitably performing the above.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a filter layer is formed on a filter medium support plate made of a porous material by laminating and supporting a massive fibrous filter medium, through which water to be treated passes downward in a filtration tank. In order to achieve the above-mentioned object, it is proposed that a filter device for cleaning a fibrous filter medium be configured as follows, in order to achieve the above object.

That is, in the cleaning method of the present invention,
A partition plate made of the same porous material as the filter medium support plate is arranged in a predetermined amount in the upward direction of the filter layer, and the partition plate and the filter medium support plate allow the filter tank to pass through the filter tank in an intermediate region and the intermediate region. It is divided into upper and lower areas, and a part of the washing water filled in the filtration tank is taken out of the tank from the upper area, pressurized, and forms a horizontal swirling flow along the inner peripheral surface of the filtration tank. The cleaning air is circulated and supplied to the lower region, and the cleaning air is concentrated and jetted from a part of the lower region to the intermediate region in a direction directly above the lower region.

Further, the washing apparatus of the present invention for carrying out such a method is made of a porous material similar to the filter medium support plate, is disposed in a predetermined amount upward of the filter layer, and supports the filter medium support in the filter tank. Along with the plate, a partition plate that partitions the intermediate region where the filtration layer exists and the upper and lower regions, and a part of the washing water filled in the filtration tank is taken out of the upper region out of the tank, pressurized, and filtered. A washing water circulation mechanism that circulates and supplies a horizontal swirling flow along the inner peripheral surface of the tank to the lower area, and a cleaning air jet that concentrates and jets cleaning air from a part of the lower area to the intermediate area part just above it And a mechanism.

According to this configuration, a part of the washing water filled in the filtration tank is circulated and supplied from the upper region to the lower region in a horizontal swirling flow, and a part of the lower region is circulated to the intermediate region. When the local and intensive air ejection is performed in the region, the lower region where the air ejection is performed is locally depressurized in the lower region, which is combined with the fact that the washing water is horizontally swirled. Then, the washing water flows into the lower region portion in a concentrated manner, and rises together with the blast air to the intermediate region portion immediately above the lower region portion. That is, the horizontal swirling flow in the lower region and the local and intensive air ejection exert a kind of air lift effect, and a strong upward flow due to the gas-liquid mixed fluid is generated in the intermediate region. The upward flow is further strengthened by the forced circulation of a part of the washing water from the upper region to the lower region, and is continuously generated. Therefore, even when the fibrous filter medium constituting the filter layer is in a compacted state by high-speed filtration or in an intimate state due to trapped contaminants, the filter layer is loosened in an extremely short time, and the fibrous filter medium easily floats. . Further, in the intermediate region, the entire surface is not aerated, and the aeration is performed only in the intermediate region, which is a part of the intermediate region. A large density difference occurs between the region and the region. Therefore, in combination with the fact that the air lift effect described above is exhibited, in the intermediate region,
A circulating flow is generated which rises in the middle region as the aeration region and descends in the middle region as the non-aeration region, whereby the fibrous filter medium loosened as described above is uniformly mixed and stirred. From these facts, in the intermediate region, the fibrous filter medium is uniformly mixed and agitated in the washing water, and is strongly rubbed and washed, and the pollutants trapped by the fibrous filter medium are easily peeled off. Different.

[0013]

FIG. 1 is a block diagram showing an embodiment of the present invention.
5 to FIG. 5 and FIG. 6 to FIG.

FIGS. 1 to 5 show a first embodiment, and this embodiment relates to an example in which the present invention is applied to a pressure-type filtration device. That is, the filtering device, as shown in FIG. 1, the cleaning apparatus 2 ₁ annexed to the filtration tank 1 ₁ of the pressure type
Consists of

[0015] Filtration tank 1 _1, as shown in FIGS. 1 and 5,
The filter layer 3 has a cylindrical closed container structure, in which a filter layer 3 having a predetermined thickness formed by laminating a massive fibrous filter medium 3a is formed. As the fibrous filter material 3a, a material having a specific gravity lower than that of the water 7 to be treated and having a large specific surface area having elasticity and having a spherical shape or a mass similar thereto is used. Specifically, for example, a synthetic fiber having an appropriate length (for example, polyvinylidene chloride fiber having a diameter of 80 μm)
A crimped yarn made into a bundle, a central portion thereof is bound, and a spherical shape (for example, a diameter of 33 mm) is used.

As shown in FIG. 1, the filtration layer 3 comprises a filtration tank _11.
It is supported by disposed filter media supporting plate 4 ₁ to the bottom of. The filter medium support plate 4 ₁ has been configured with punching metal, porous metal net like member, a disk-shaped central portion 4a positioned horizontally in the center of the filtration tank 1 _1, inclined from the center 4a upward And an outer peripheral portion 4b in the shape of a truncated cone. As the constituting material serving porous material of the filter medium support plate 4 _1, on condition that the fibrous filter medium 3a is not transmitted, it is preferable that the opening ratio (pore size) to use a much as possible greater. In addition, the inclination angle of the outer peripheral portion 4b (the filtration tank ₁₁₎
Is preferably set to 30 ° or more.

[0017] peripheral wall upper and the bottom wall central portion of the filtration tank 1 _1, as shown in FIG. 1, the outlet 6 of the inlet 5 and the treated water 7a of the water to be treated 7 is provided. The inlet 5 is connected to a water supply channel led from the water source to be treated via an on-off valve 5a, and the outlet 6 is led to the treated water using section via an on-off valve 6a. The waterway is connected.

The pressure-type filtration tank 1 constructed as described above.₁
According to FIG. 1, the on-off valves 5a and 6a are opened as shown in FIG.
In a state where the water to be treated 7 is₁Within
When supplied continuously, the water 7 to be treated can cause the filtration layer 3 to flow at a high speed (eg,
For example, it passes at 120 m / h).
The pollutants contained in the water 7
Captured and removed. And it is polluted by the fibrous filter medium 3a.
The treated water 7a from which the substance has been removed is supported from the filtration layer 3 by the filter medium.
Board 4₁Through the outlet 6 and continuously from the tank 1 ₁Out
Taken out.

The cleaning apparatus 2 ₁ according to the present invention, FIGS. 1 to 6
As shown in, provided with a partition plate 8 and the cleaning water supply and discharge port 9 in the filtration tank 1 _1, the washing water circulation mechanism 11, formed by attaching a flushing air ejection mechanism 12 and an exhaust mechanism.

The partition plate 8 is a disk made of filter material support plate 4 ₁ and the same porous material, lower than the water supply port 5 from the surface of the filtration layer 3 (top) a predetermined amount a location spaced upwardly It is stretched horizontally. The filtration tank 1 _1, the filter medium support plate 4 ₁ and the partition plate 8, and is divided into a middle region 13 in which the filtration layer 3 is present and the upper and lower regions 14, 15.

The washing water supply port 9 is provided in the peripheral wall lower portion of the filtration tank 1 _1, by opening the on-off valve 9a, becomes the washing water 17 from the lower area 15 is supplied to the filtration tank 1 ₁ ing. The cleaning water 17 is not limited to clean water, but may be somewhat polluted water. In this example, the supply port 9 is branched and connected to the water supply path via an on-off valve 9a, so that the water to be treated 7
I'm trying to use The cleaning water outlet 10 is provided in the bottom wall central portion of the filtration tank 1 _1, the on-off valve 10
By opening a, it is adapted to stretch discharging washing water 17 of the filtration tank 1 _1. A drainage channel led to an appropriate secondary treatment facility is connected to the washing water discharge port 10 so that washing wastewater 17a, which is washing water after the washing treatment, is returned from the filtration tank ₁₁ to the secondary treatment facility. It has become.

The washing water circulation mechanism 11 is composed of a filtration tank 1 ₁ wash water circulation passage disposed outside 18 and booster pump 19 which is interposed thereto. The washing water circulation path 18 has an upper end 18 a communicating with the upper region 14 and a lower end 18 b communicating with the lower region 15. The lower end 18b of the washing water circulation path 18, as shown in FIG. 5 (A) (B), state (B view projecting from the inner peripheral surface flush with (A panel) or the inner peripheral surface of the filtration tank 1 ₁ ), The opening is open in the tangential direction to the circular inner peripheral surface and in the horizontal direction. Booster pump 19 via the washing water circulation path 18, a portion 17b of the washing water 17 bath 1 ₁ taken out to the outside from the upper region 14, in which circulates supplied to the lower region 15 on pressurized to a predetermined pressure is there. That is, the pressurized washing water 17b, by supplying tangentially (press-fit) with the inner circumference of the filter tank 1 ₁ from the lower end 18b of the washing water circulating path 18, as shown in FIG. 5, the lower region 15 A horizontal swirling flow 17c along the inner peripheral surface is generated. In addition, since the booster pump 19 is a publicly known thing, the explanation about the structure is omitted.

The cleaning air jetting mechanism 12 includes a filter medium support plate 4 _1.
And a nozzle body 21 disposed in a lower region portion 15a partitioned by the cylindrical partition plate 20. The partition plate 20 is obtained by fixing the upper edge portion at the boundary between the central portion 4a and the outer peripheral portion 4b formed on the bottom surface portion of the filter medium support plate 4 _1, its lower edge filtration tank 1
It is positioned in a predetermined amount higher than the _first bottom wall. Nozzle body 2
Numeral 1 is provided with a large number of air ejection holes directed upward, and the cleaning air 22 is supplied to a lower region portion 1 partitioned by a partition plate 20.
It is configured to blow in a concentrated manner from 5a to the intermediate region 13a in the direction directly above it.

The pumping mechanism, exhaust from the suction port side portion of the filtration tank 1 ₁ of the upper wall central portion and the exhaust port 23a to the upstream portion of the washing water circulation path 18, will be provided 23b, upper region 14 and the booster pump 19 Or degas. Both exhaust ports 2
3a and 23b merge and are opened and closed by a common exhaust valve 23c.

[0025] In Thus, the cleaning method according to the present invention uses the cleaning apparatus 2 ₁ described above is performed as follows.

First, a water filling step is performed. That is, the on-off valves 5a, 6a, and 10a are closed and the exhaust valve 23c is opened, and the washing water 17 is supplied from the washing water supply port 9 to the filtration tank 1.
₁ to fill the wash water 17 up to the upper region 14,
By closing the on-off valve 9a, the filtration tank 1 _1, as shown in FIG. 2, the water level upper portion 18a of the washing water circulation path 18
And keep it over water.

Then, as shown in FIG. 3, the cleaning air 22 is blown out from the nozzle body 21, and the cleaning air 22 is intensively blown from the lower region portion 15a to the intermediate region portion 13a directly above the lower region portion 15a. By operating 19, a part 17 b of the washing water 17 is pumped from the upper region 14 to the lower region 15 via the washing water circulation path 18 to start the washing process of the fibrous filter medium 3 a.

When the washing step is started, a part 17 b of the washing water 17 is pressurized by the booster pump 19 in the lower region 15 and then the lower end 18 b
Horizontal swirling flow along from being pumped supplied tangentially to the inner peripheral surface of the filtration tank 1 ₁ with respect to the inner peripheral surface of the filter tank 1 ₁ 1
7c will be formed. In the lower region 15, the cleaning air 22 is ejected from the nozzle body 21.
Causes a local pressure drop in the lower region portion 15a where the gas is jetted. As a result, FIGS. 3 and 5
As shown in FIG.
17d, the washing water 17 flows from below the partition plate 20 into the lower region portion 15a, and rises to the intermediate region portion 13a by the air jetted from the nozzle body 21.
That is, the horizontal swirling flow 17b in the lower region 15 and the local and concentrated air ejection by the nozzle body 21 exhibit a kind of air lift effect, and the intermediate region portion 13
A strong upward flow 17e due to the gas-liquid mixed fluid is generated in a. The upward flow 17e becomes stronger due to the forced circulation of the cleaning water 17b by the booster pump 19, and is continuously generated. Therefore, even when the fibrous filter medium 3a constituting the filtration layer 3 is in a compacted state by pressure type high-speed filtration or in a tightly adhered state by trapped contaminants, the filtration layer 3 is loosened in a very short time,
The fibrous filter medium 3a floats easily.

In the intermediate portion 13, a large density difference exists between the intermediate portion 13 a where air is blown from the nozzle body 21 and the intermediate portion 13 b where air is not blown. Will occur. Accordingly, in combination with the above-described effect of the air lift, in the intermediate region 13, as shown in FIG. 3, the former intermediate region portion 13 a is raised and the latter intermediate region region 13 b is lowered. A strong circulating flow 17f is generated. As a result, the fibrous filter medium 3a loosened as described above is uniformly mixed and stirred in the intermediate region 13 by the circulating flow 17f.

As described above, when the washing step is started, the fibrous filter medium 3a constituting the filter layer 3 is loosened in a short time,
Thereafter, the loosened fibrous filter medium 3a is mixed and stirred in the washing water 17, and is strongly rubbed and washed, so that the pollutants trapped in the fibrous filter medium 3a are easily peeled off. .

After a certain period of time, a drainage step is performed. That is, after having stopped the booster pump 19 temporarily opens the on-off valve 10a, at once washing waste liquid 17a containing pollutants peeled from the wash water, i.e. fibrous filter media 3a of the filtration tank 1 ₁ from the discharge port 10 Discharge (FIG. 4).
Thereafter, by repeating a series of steps from the water filling step to the draining step several times (normally, two to three times) in a batch, the fibrous filter medium 3a can be completely washed.

By the way, using the filtration device shown in FIG. 1, a filtration operation is performed at a filtration speed of 120 m / h until the filtration head reaches a fixed value, and then the fibrous filter medium 3a is completely washed by the above-described method. did. In addition, after performing a filtration operation under the same conditions using the filtration device, the fibrous filter medium 3a was completely washed by the same method except that the booster pump 19 was not operated. As a result, in the former case, the compacted filter layer 3 was loosened quickly, but in the latter case, it took more than 5 minutes to loosen the filter layer.
The amount of washing water required until the fibrous filter medium 3a was completely washed was about 1% of the amount of filtered water in the latter case, but was about 0.5% in the former case. Was. For these reasons, forcibly circulating a portion 17b of the cleaning water 17 in a state where the horizontal swirling flow 17c is formed in the lower region 15 significantly reduces the cleaning time and the amount of cleaning water and improves the cleaning efficiency. It was confirmed to be extremely effective and important.

FIGS. 6 to 11 show a second embodiment, which relates to an example in which the present invention is applied to a pressure-type filtration device as in the first embodiment.

In this embodiment, the filtering device comprises:
Filtration tank configurations pressure equation as follows: 1 ₂ and the cleaning device 2
_{Consists of two} .

[0035] That is, the filtration tank 1 _2, as shown in FIGS. 6 to 11, except that is stretched horizontally in a bath under the filter medium support plate 4 ₂ as a disc shape, the filter tank 1 ₁ And has the same filtering function. Note that the components of the filtration tank 1 _2, except for the filter medium support plate 4 _2, by subjecting the same sign and the filter tank 1 ₁ of the constituent members corresponding thereto in FIGS. 6 to 11, their description Is omitted.

The cleaning apparatus 2 _2, as shown in FIGS. 6 to 11, those having a partition plate 8 and the cleaning water supply and discharge port 9 and the cleaning water circulation mechanism 11 and the cleaning air ejection mechanism 12 and an exhaust mechanism There, with the exception of cleaning air jetting mechanism 12 to be described below, in which form the cleaning apparatus 2 ₁ and the same configuration. For example, the lower end portion 18b of the washing water circulation path 18, the as in the cleaning apparatus 2 _1, as shown in FIG. 10 (A) (B), flush with the inner peripheral surface of the filtration tank 1 ₂ (A panel) Alternatively, in a state of protruding from the inner peripheral surface (FIG. B), the circular swirling flow is opened in the tangential direction to the inner peripheral surface and in the horizontal direction, and the washing water 17b flows along the inner peripheral surface. 17c
To be supplied to the lower region 15. Incidentally, the respective components of the cleaning apparatus 2 ₂ except cleaning air jetting mechanism 12, the cleaning apparatus 2 corresponding thereto
6 to 11 are given the same reference numerals as those of the _first constituent member, and the description thereof will be omitted.

The cleaning air jetting mechanism 12, as shown in FIGS. 6 to 11, the lower surface of the filter medium support plate 4 _2, and vertically a rectangular partition plate 20a by disposing on its diameter line, the filter media support The first and second lower area portions 15b,
15c and the first and second lower region portions 1
The first and second nozzle bodies 21a and 21b are separately arranged on 5b and 15c. Each nozzle body 21a, 21b, similar to the cleaning device 2 _first nozzle member 21, which has a plurality of air ejection holes for ejecting the cleaned air 22 upward, the lower region portion 15b, a 15c The cleaning air 22 is spouted in a concentrated manner at the respective intermediate region portions 13c and 13d in the azimuthal direction.

[0038] In Thus, in the second embodiment, the cleaning method according to the present invention uses the cleaning apparatus 2 ₂ described above is carried out as follows.

[0039] That is, as in the first embodiment, satisfy the washing water 17 in the filtration tank 1 _1, the water is held in the water Zhang state exceeding an upper end 18a of the washing water circulation path 18.

Thereafter, as shown in FIG. 6, the cleaning air 22 is jetted from the first nozzle body 21a, and the cleaning air 22 is concentrated from the first lower region portion 15b to the intermediate region portion 13c in a direction immediately above the first lower region portion 15b. At the same time, the booster pump 19 is operated to pump a part 17b of the cleaning water 17 from the upper region 14 to the lower region 15 via the cleaning water circulation path 18 to start the first cleaning step.

In the first cleaning step, as shown in FIGS. 6 and 10, the flow 17 to the first lower region portion 15b in the lower region 15 is performed as in the first embodiment.
'D occurs and the horizontal swirling flow 17b in the lower region 15
A kind of air lift effect is exerted by local and intensive air ejection by the first nozzle body 21a, and a strong ascending flow 1 by the gas-liquid mixed fluid flows into the first intermediate region portion 13c.
7′e occurs. The upward flow 17'e becomes stronger due to the forced circulation of the cleaning water 17b by the booster pump 19, and is continuously generated. Therefore, even when the fibrous filter medium 3a constituting the filtration layer 3 is in a compacted state by pressure-type high-speed filtration or in a close contact state by trapped contaminants, the filtration layer 3 is loosened in a very short time, The filter medium 3a floats easily. Further, in the intermediate region 13, the density between the first intermediate region portion 13 c where air is blown from the first nozzle body 21 a and the second intermediate region portion 13 b where air is not blown is formed. As a result, as shown in FIG. 6, a strong circulating flow 17'f is generated which rises in the first intermediate region 13c and descends in the second intermediate region 13d. As a result, the fibrous filter medium 3a loosened as described above is uniformly mixed and stirred in the intermediate region 13 by the circulation flow 17'f.

After the first cleaning step is continued for a predetermined time, the aeration function is changed from the first nozzle body 21a to the second nozzle body 2.
Switching to 1b, the process proceeds to the second cleaning step. In other words, the cleaning air 22 is jetted from the second nozzle 21b at the same time as the air jetting from the first nozzle 21a is stopped. In this way, the flow 17''d to the second lower region portion 15c occurs in the lower region 15, as shown in FIGS.
Ascending flow 1 due to the gas-liquid mixed fluid in the second intermediate region portion 13d
7 ″ e occurs and the second region 13
The first intermediate region portion 1 is raised by moving up the intermediate region portion 13d.
A circulating flow 17''f descending from 3c is generated, and the fibrous filter medium 3a is mixed and stirred while circulating in the reverse direction.

Accordingly, the fibrous filter medium 3a constituting the filtration layer 3 is loosened immediately after the start of the first washing step, and the circulating flow 1 in the first washing step and the subsequent second washing step.
By changing the directions of 7′e and 17 ″ e, the mixing and stirring of the fibrous filter medium 3a can be performed more effectively, and the fibrous filter medium 3a can be cleaned extremely well.

After a certain period of time has elapsed after the start of the second cleaning step, as shown in FIGS.
The draining step is performed in a state where the cleaning air 22 is jetted from the nozzles 21a and 21b. That is, the intermediate region 13 is completely aerated by the two nozzles 21a and 21b, and the fibrous filter medium 3
a is uniformly dispersed (FIG. 8), and the washing wastewater 17a is discharged from the discharge port 10 at a stroke, and the filtration layer 3 having a uniform thickness is discharged.
Is formed (FIG. 9).

By the way, in this embodiment, similarly to the first embodiment, a series of steps from the water filling step to the draining step described above is performed several times in a batch (usually,
2 to 3 times), but usually both nozzles 21a, 21b
Will be performed only in the final drainage process. Also, by performing the entire surface aeration after the final drainage step is completed, the layer thickness can be made uniform.

It should be noted that the present invention is not limited to the above-described embodiments, and can be appropriately improved and changed without departing from the basic principle of the present invention.
For example, the present invention is particularly suitable when the filtration layer 3 is extremely compacted by performing high-speed filtration at a speed exceeding 30 m / h (for example, when a pressure-type filtration device is used). However, the present invention can be applied to cases other than such cases, and the same effective cleaning as described above can be performed.

[0047]

As will be easily understood from the above description, according to the present invention, a high-speed filtration device (for example, a filtration speed exceeding 30 m / h) in which the filtration layer is extremely compacted by the velocity head. In such a filtration device, the filtration layer can be quickly loosened, and the amount of washing water and the washing time can be significantly reduced, and the fibrous filter medium can be effectively washed, thereby greatly improving the filtration efficiency. be able to.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view showing a first embodiment of a cleaning apparatus according to the present invention.

FIG. 2 is a view corresponding to FIG. 1 showing a water filling process.

FIG. 3 is a view corresponding to FIG. 1 showing a cleaning step.

FIG. 4 is a view corresponding to FIG. 1 showing a drainage step.

FIG. 5 is a cross-sectional bottom view of a main part along the line VV in FIG. 3;

FIG. 6 is a vertical sectional front view showing a second embodiment of the cleaning apparatus according to the present invention, showing a cleaning step.

FIG. 7 is a diagram corresponding to FIG. 6, showing a cleaning process in a state different from FIG. 6;

FIG. 8 is a diagram corresponding to FIG. 6, showing a drainage process.

FIG. 9 is a diagram corresponding to FIG. 6, showing a cleaning completed state.

FIG. 10 is a cross-sectional bottom view of a main part taken along line XX of FIG. 6;

11 is a cross-sectional bottom view of a main part taken along line XI-XI in FIG. 7;

[Explanation of symbols]

1 _1, 1 ₂ ... filtration tank, 2 _1, 2 ₂ ... cleaning device, 3 ... filtration layer, 3a ... fiber filter medium, 4 _1, 4 ₂ ... medium support plate 7 ...
Water to be treated, 7a: treated water, 8: partition plate, 11: washing water circulation mechanism, 12: washing air jetting mechanism, 13: middle area,
14 ... upper area, 15 ... lower area, 17 ... washing water, 17
b: a part of washing water, 17c: horizontal swirling flow, 21, 21
a, 21b: nozzle body, 22: cleaning air.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshio Koshida 5-17-22 Noda, Fukushima-ku, Osaka-shi, Osaka

Claims (2)

[Claims] 1. A filter device comprising: a filter material support plate made of porous material; and a mass of fibrous filter media laminated and supported on the filter media support plate to form a filter layer through which water to be treated passes downward in a filtration tank. A partition plate made of the same porous material as the filter medium support plate is disposed in a predetermined amount in the upward direction, and the partition plate and the filter medium support plate allow the inside of the filtration tank to have an intermediate region where a filter layer is present and upper and lower portions thereof. A part of the washing water filled in the filtration tank is taken out of the tank from the upper area, pressurized, and then formed into a horizontal swirling flow along the inner peripheral surface of the filtration tank. Washing the fibrous filter medium in the filtration device, wherein the washing air is circulated and supplied, and the washing air is intensively jetted from a part of the lower area to an intermediate area part just above the lower area. 2. A filter device comprising a filter medium support plate made of a porous material and a massive fibrous filter medium laminated and supported thereon to form a filtration layer through which water to be treated passes downward in a filtration tank. A partition made of the same porous material as the plate and arranged in a predetermined direction upward of the filter layer, and partitions the inside of the filter tank, together with the filter medium support plate, into an intermediate region where the filter layer is present and upper and lower regions thereof. A plate and a part of the washing water filled in the filter tank are taken out of the tank from the upper region, pressurized, and then circulated and supplied to the lower region in a horizontal swirling flow along the inner peripheral surface of the filter tank. A cleaning device for a fibrous filter medium in a filtration device, comprising: a mechanism; and a cleaning air jetting mechanism for concentrating and jetting cleaning air from a part of a lower region to an intermediate region in a direction directly above the lower region.