JP3239920B2 - Combined filtration device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filtration device for pond water, river or sewage secondary treatment water, industrial wastewater, domestic wastewater, etc., and more particularly to a composite filtration device combining a hollow fiber membrane module and a granular filter medium. .

[0002]

2. Description of the Related Art Conventionally, a device in which solid-liquid separation is performed by a sand filtration device or the like is introduced into a device in which a large number of external pressure type hollow fiber membrane modules are suspended, and the filtrate is further introduced into the hollow fiber membrane filtration device to further perform solid-liquid separation. Are well known, for example, as described in JP-B-60-43162. When the hollow fiber membrane is clogged, backwash water or backwash air is supplied into the filter membrane, or wash water or air flows on the filter membrane surface to regenerate the membrane surface.

[0003]

However, in the conventional membrane filtration apparatus, when the solid content of raw water increases, clogging of the filtration membrane occurs, the filtration pressure increases, and the amount of treated water decreases. In order to prevent this, a solid-liquid separation device such as a sand filtration device was required before and after that. When the filtration membrane was clogged, backwashing or surface washing was performed, but complete washing was difficult. The present invention provides a composite filtration device that enables membrane filtration without providing a filtration device for pretreatment and that can easily be regenerated when the hollow fiber membrane is clogged.

[0004]

According to the structure of the present invention, a filtration tank is filled with a floating filter medium, a plurality of hollow fiber membrane modules are suspended in a filter medium layer formed by the floating filter medium, and a hollow fiber membrane is formed. The filtrate is taken out of the filter tank, and a filter device provided with a stirrer for the filter layer is provided below the filter layer.
Te, the hollow fiber membrane module, it is possible to house the multiple hollow fiber membranes reticulated tube is no less the tower mounting space to the filtrate take-out portion filtration tank be used that focuses the. If the hollow fiber membrane module is configured in a spiral or arc shape when performing mechanical stirring, the hollow fiber membrane module is easy to clean, and in particular, a spiral hollow fiber membrane module is provided at the center of the filtration tank. If an arc-shaped hollow fiber membrane module is arranged on the outer periphery, the effect of stirring and washing can be obtained.

[0005]

The composite filtration apparatus according to the present invention is configured as described above. The raw water supplied to the filtration tank is firstly filtered after the impurities are trapped and removed by the filter medium layer formed by the floating filter medium, and then the hollow water is removed. Fine solids are captured by the thread membrane module,
The separated liquid is taken out of the tank through the hollow portion of the hollow fiber membrane. When the filter medium layer and the hollow fiber membrane module are clogged, the raw water below the filter medium layer is stirred by the stirring device, and the filter medium layer is loosened by flowing the raw water,
The contaminants clogged between the particles are separated, and the stirred floating filter medium and the flowing undiluted solution come into contact with the membrane surface of the hollow fiber membrane, peeling off the solid matter adhering to the hollow fiber membrane module. Can be played at the same time. Then, the floating filter material enters between the hollow fiber membranes of the hollow fiber membrane module, a gap between the hollow fiber membranes is secured, and the filtration area of the hollow fiber membrane can be effectively used. If the hollow fiber membrane module is configured in a spiral or arc shape, the hollow fiber membrane can be arranged along the stirring water flow, and the floating filter medium can be brought into contact with the membrane surface of each hollow fiber membrane It is. The separated contaminants and solids are separated from the floating medium by a discharge means provided in the filtration tank and discharged outside the tank.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to an embodiment. First, in FIG. 1, reference numeral 1 denotes a filtration tank, and a filtration chamber 2 of the filtration tank 1 accommodates a floating filter medium 3 and a filter medium layer. 4
Is formed. This floating filter material 3 has a specific gravity of 0.01 to
1. Spherical, elliptical, cylindrical, disk-shaped filter media and fiber lumps having a filter media diameter of 0.5 to 20 mm can be used. A water collecting chamber 5 is provided at an upper portion of the filtration chamber 2, and a plurality of hollow fiber membrane modules 7 are suspended from a filter plate 4 of the filtration chamber 2 by being supported by a partition plate 6 of the water collecting chamber 5. In this hollow fiber membrane module 7, a large number of external pressure type hollow fiber membranes 9 are stored in a mesh tube 8, and the filtrate taking-out portion of the hollow fiber membrane 9 is bundled and supported by the partition plate 6. And the filtrate separated by the hollow fiber membrane 9 is collected in the collecting chamber 5
I have to collect it. The hollow fiber membrane module 7 will be described in detail. The hollow fiber membrane module 7 may contain an external pressure type hollow fiber membrane 9 in a cylindrical mesh tube 8, but as shown in FIG. Helical hollow fiber membrane module 7a with fiber membranes 9.
And the spiral mesh tube 8a may be vertically arranged in the filtration tank 1 shown in FIG.
As shown in FIG. 3, houses a number of external pressure type hollow fiber membrane 9 reticulated tube 8b formed in an arc shape, the arc-shaped hollow fiber membranes
The module 7b may be arranged in the filter tank 1 shown in FIG. 4 in the circumferential direction.

[0007] A stirring device 10 is provided at the bottom of the filtration chamber 2 to stir the floating filter medium 3 when the filter medium layer 4 is clogged. This stirring device 10 is shown in FIGS.
In this embodiment, a stirring blade 10a is provided . When the mechanical stirring is performed by the stirring blade 10a, the flow of the stirred water flow and the flow of the floating filter medium 3 are provided by disposing the hollow fiber membranes 9 in the spiral or arcuate mesh tubes 8a and 8b. Since the hollow fiber membranes 9 are arranged along the direction, the regeneration of the membrane surface becomes easy. Further, as shown in FIG. 5, an arc-shaped hollow fiber membrane module 7b is arranged on the outer periphery where a swirling upward flow occurs due to mechanical stirring, and a spiral hollow is disposed in the center where the raised raw water flows downward. If the yarn membrane module 7a is provided, the cleaning effect is improved. Further, the mesh tubes 8, 8a, 8b in which the hollow fiber membranes 9 are housed prevent the hollow fiber membranes 9 from being broken, and can reduce the space for mounting the tower in the filtration tank 1. Since the lower end of the hollow fiber membrane 9 is freely movable in the mesh tube 8, the agitated floating filter medium 3 enters between the hollow fiber membranes 9.9, and the gap between the front and rear membrane surfaces is reduced. Thus, the filtration area of the hollow fiber membrane 9 can be used effectively.

A separation tank 11 is provided at the bottom of the filtration tank 1, and a raw water supply pipe 12 is connected to the separation tank 11. A raw water pump 14 is connected to the raw water supply pipe 12 via an inflow valve 13. In the raw water supplied from the raw water supply pipe 12 to the filtration chamber 2, a relatively large solid content is captured by the filter medium layer 4, the solid content is reduced, and only the raw water containing fine particles is supplied to the hollow fiber membrane module 7. It can be supplied to. Therefore, since the raw water can flow between the hollow fiber membranes 9.9, the filtration surface of the hollow fiber membrane 9 on the inner surface side is not wasted. A drain pipe 16 provided with a drain valve 15 is branched and connected to the raw water supply pipe 12, and when the raw water in the filtration chamber 2 is concentrated to a high concentration, the raw water pump 14 is stopped, The drain valve 15 is opened to discharge the raw water.

A treated water pipe 18 provided with a treated water valve 17 is connected to an upper portion of the filtration tank 1 so as to take out separated water from the water collecting chamber 5. The air pipe 1 is connected to the treated water pipe 18.
The compressor 9 is connected to the air pipe 19 via an air injection valve 21. When the hollow fiber membrane 9 is clogged, the treated water valve 17 is closed, the discharge valve 23 provided on the discharge pipe 22 is opened, and if the compressor 20 is operated, the treated water in the water collecting chamber 5 is compressed by compressed air. The hollow fiber membrane 9 is pressed down and pressed into the inside of the hollow fiber membrane 9 to backwash the membrane surface of the hollow fiber membrane 9, and then air-washed with compressed air. At the same time, the stirring blade 10
a, the raw water is mechanically stirred , the contaminants trapped in the filter medium layer 4 are decomposed to eliminate the clogging of the filter medium layer 4, and the flow of the raw water due to the stirring and the turbulent flow of the floating filter medium 3 cause the hollow fiber membrane 9 The surface of the film is cleaned. Then, the raw water supply pump 14 is operated continuously during the washing, and the contaminants separated by the washing are washed out from the discharge pipe 22, and the backwash water or the backwash air is simultaneously discharged from the discharge pipe 22. If the open end of the discharge pipe 22 is disposed above and in the vicinity of the hollow fiber membrane modules 7a and 7b, the concentration of the hollow fiber membrane 9 around the hollow fiber membrane 9 is replaced by raw water during washing and regeneration, and the hollow fiber membrane module 7a, The SS concentration around 7b is unlikely to increase. Reference numeral 24 denotes the stirring blade 10a.
Drive motor 25 is an arc-shaped hollow fiber membrane module 7
b is a supporting bracket.

[0010]

The present invention is configured as described above,
Even if the supplied raw water has a high concentration, after the solid matter having a large particle diameter contained in the raw water is captured by the filtration layer, a low-concentration raw water containing only fine particles is supplied to the hollow fiber membrane. Therefore, composite filtration can be performed. That is, in the conventional apparatus, in the case of high-concentration raw water, solids are deposited on the outer peripheral surface of the hollow fiber membrane module, and there is a possibility that the inner side filtration membrane is wasted. Since the raw water is supplied to the hollow fiber membrane module after the solid content is captured by the filter medium layer, the raw water can flow into the space between the hollow fiber membranes at the center. Then, the granular filter medium enters between the hollow fibers of the hollow fiber membrane, and a gap between the hollow fiber membranes is secured, so that the filtration area of the hollow fiber membrane can be effectively used. Moreover, when clogging occurs in the filter medium layer and the hollow fiber membrane module, the filter medium layer is agitated by the stirring device to eliminate the clogging, and the flow of the stirred raw water and the turbulent flow of the granular filter medium cause the hollow fiber membrane to be clogged. It can clean the film surface, remove clogs, and regenerate the film surface. Further, if the hollow fiber membrane is housed in a mesh tube to constitute a hollow fiber membrane module, breakage of the hollow fiber membrane during stirring can be prevented. If the hollow fiber membrane is housed in a spiral tube or an arc tube to constitute a hollow fiber membrane module, the surface of the hollow fiber membrane can be arranged along the stirring water flow.

[Brief description of the drawings]

FIG. 1 is a side view of a composite filtration device according to the present invention.

FIG. 2 is a partially cutaway side view of a spirally formed hollow fiber membrane module according to the present invention.

FIG. 3 is a partially cutaway side view of a hollow fiber membrane module similarly formed in an arc shape.

FIG. 4 is a side view of a composite filtration device of another embodiment in which an arc-shaped hollow fiber membrane module is provided in a filtration tank.

FIG. 5 is a side view of a composite filtration device according to another embodiment in which spiral and arc-shaped hollow fiber membrane modules are provided in a filtration tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Filtration tank 3 Floating filter medium 4 Filter medium layer 7 Hollow fiber membrane module 7a Spiral hollow fiber membrane module 7b Arc-shaped hollow fiber membrane module 8 Net tube 8a Spiral net tube 8b Arc net tube 9 Hollow fiber membrane 10 Stirrer 10a Stirrer

──────────────────────────────────────────────────の Continued on front page (51) Int.Cl. ⁷ Identification code FI B01D 29/08 540A

Claims (3)

(57) [Claims] 1. A filtration tank 1 is filled with a floating filter medium 3, and a plurality of hollow fiber membrane modules 7 are suspended in a filter medium layer 4 formed by the floating filter medium 3 to filter the hollow fiber membrane 9 from the inside. The liquid is taken out of the filtration tank 1, and below the filter medium layer 4,
In the filtration device provided with the stirring device 10 for the filter medium layer 4 ,
The hollow fiber membrane 9 is a number stored in the mesh tube 8, as well as constituting a hollow fiber membrane module 7, a large number of hollow fiber membranes housed 9 &
..Concentrating the filtrate taking-out part and using the stirring device 10 with a stirring blade
A composite filtration device characterized by mechanical stirring according to 10a . 2. A hollow fiber membrane module 7 of the spiral 7
claim a feature by being configured to a or arcuate 7b 1
The composite filtration device according to item 1. 3. A hollow fiber membrane module 7 was suspended in the filter tank 1 above, the heart of the filtration tank 1 is disposed a spiral hollow fiber membrane module 7a, arcuate hollow peripherally thereof claim the feature that it has provided a fiber membrane module 7b 1
Or the composite filtration device according to claim 2 .