JP2002346310A - Filter element and filter module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter element suitable for the pretreatment of a membrane module and also excellent in terms of cost, and a filter module. SOLUTION: The filter element is constituted by spirally winding a filter layer, which is formed by alternately laminating filter cloths formed into an envelope shape to house spacers and separate spacers, around a center pipe having a water gathering hole of filtered water and the opening parts of the filter cloths formed into the envelope shape are opposed to the water gathering hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a liquid having excellent durability and production cost, which can be suitably used as a pretreatment means for a water treatment apparatus for treating industrial effluent or river water, particularly high turbidity water. The present invention relates to a filtration element and a filtration module provided with the filtration element.

[0002]

2. Description of the Related Art In recent years, interest in the quality of various types of water, including industrial water and clean water, has been increasing more than ever before. In addition to sand filtration for filtering large suspended substances in water,
Reverse osmosis membranes, nanofiltration membranes, ultrafiltration membranes, microfiltration membranes, etc. are made into flat membrane modules, hollow fiber membrane modules, etc., and various membrane filtrations that remove bacteria, viruses, etc. that could not be sufficiently removed by sand filtration have been developed. Have been.

[0003] However, in the case of membrane filtration, if clogging speed is increased when water containing high-turbidity water or various kinds of industrial wastewater or water containing suspended matter such as coarse trash is treated, chemical cleaning or membrane module replacement is required. Is frequently required, and the running cost increases. On the other hand, it has been proposed to provide a wind cartridge filter in which a bundle of fibers is wound up in front of the membrane module in order to suppress an increase in running cost. 10 μm, at most about 150
Due to its fineness of about μm, when high turbidity water or industrial wastewater is treated, it is immediately clogged and the differential pressure increases. Even if the differential pressure increases, the backwashing is not sufficiently performed because the thickness of the filter layer with respect to the water flow is large because the bundle of fibers is wound around the cartridge filter many times. Therefore, the frequency of replacement and cleaning increases, and the running cost increases. Sand filtration can be provided in front of the membrane module instead of the cartridge filter. However, in the case of sand filtration, the equipment itself is expensive and large-scale.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a filtration element and a filtration module which are suitable for pretreatment of a membrane module and which are excellent in cost.

[0005]

According to the present invention, a filter layer formed by alternately laminating filter cloths and spacers is provided around a central pipe having a hole for collecting filtered water. It features a filtration element wound in a shape. The present invention also provides a filter layer formed by alternately laminating an envelope-like filter cloth containing a spacer therein and another spacer, and forming a filter layer around a central pipe having a hole for collecting filtered water. , Characterized in that the opening of a filter cloth formed in an envelope shape is opposed to the water collecting hole.
Here, in the filter element of the present invention, the filter cloth is preferably a woven or knitted fabric.

[0006] Further, any one of the above filtration elements is
A filtration module housed in a cylindrical body having detachable end plates at both ends is also preferable. In this case, one end plate has a raw water supply port, and the other end plate has a filtrate water outlet and a backwash water supply port / air. More preferably, an outlet is provided.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A filtration module according to the present invention is provided, for example, in a module case (tubular body) 1 having end plates 2 at both ends as shown in FIG. 14 are housed.

The module case 1 can be made of metal, plastic, or the like. By providing detachable end plates 2 at both ends, it is possible to seal liquid-tightly and load and unload elements. become. The end plate 2 and the module case 1 have a flange structure via an elastic O-ring or packing, and are fixed with split rings, screws, bolts and nuts. Of the two end plates 2 provided at both ends, one end plate 2 is provided with a raw water supply port 3, and the other end plate 2 is provided with a filtered water outlet 4 and a backwash water supply port / air outlet 5.
Is provided. The filtered water outlet 4 may also serve as a backwash water supply port and an air outlet.

As shown in FIG. 2, the filter element 14 is formed by alternately stacking a filter cloth 7 and a supply liquid flow path material (spacer) 9 around a central pipe 6 having a filtered water collecting hole. The formed filtration layer is spirally wound and formed.

At both ends of the filter element 14 in the axial direction of the center pipe, as shown in FIG. 1, a telescope for preventing a spirally wound filter layer from being deformed into a telescopic shape by water pressure. The prevention plate 10 is adhered. In addition, an elastic body such as a U-seal 13 is provided on the telescope prevention plate 10 provided downstream of the filtration element 14 so that raw water does not enter the filtered water side. Further, the filament 11 impregnated with the adhesive is wound around the outer periphery of the filtration element 14 to ensure form stability.

The central pipe 6 prevents the form of the filter element from being deformed when the differential pressure between the filtration side pressure and the supply pressure increases, and has a plurality of water collecting holes for collecting filtered water. Having. The size and number of the water collecting holes are determined depending on the amount of water to be treated, although they vary depending on the raw water and the use conditions. Generally, it is preferable to provide a required number of holes having a diameter of about 1 mm to 10 mm so that the flow velocity is 0.1 m / s to 1.5 m / s.

The filtration layer is formed in an envelope shape by sealing three sides of two filtration cloths 7 with an adhesive or the like, and contains a filtrate flow path material (spacer) 8 therein. And it is surrounded by the center pipe 6 so that the opening part which is not sealed with an adhesive etc. may open (to oppose) toward a water collection hole. At this time, the envelope-shaped filter cloth formed of the two filter cloths is aligned so that the end faces are aligned when spirally wound.
For example, 10 to 30 filter cloths arranged outside at the time of winding
mm.

From the viewpoint of workability, the filter cloth 7 preferably has a circumferential length of the element of about 50 cm to 150 cm.
m (4 inches) when loaded into a module case
When loaded into a module having a diameter of about 20 cm (8 inches), 1 to 50 sheets are laminated to form a filtration layer. The number of filter cloths 7 may be appropriately changed according to the size of the module case and the thickness of the filter cloth itself to be used.

As the filter cloth 7, a woven fabric such as taffeta or tweed having a coarseness of about 10 to 5000 μm, a knitted fabric such as tricot or Russell, or a nonwoven fabric or a net can be used. These can be used properly depending on the purpose, but when removing relatively coarse dust of about 100 to 500 μm, it is preferable to use a tricot or nonwoven fabric which is commercially available as an industrial material and is suitable for workability. The filter cloth 7 is made of synthetic fibers such as polypropylene, polyethylene, polyethylene terephthalate, polyvinyl acetate, and ethylene-vinyl acetate copolymers, which are suitable for chemical liquid wastewater treatment and chemical liquid washing. Is also preferable.

As the filtrate flow channel material 8 and the supply liquid flow channel material 9, for example, polyethylene net, polypropylene net, polyvinyl acetate net, polyester tricot and the like can be used, but cost and slippage with the filter cloth can be used. Considering wrinkles generated due to the nature, it is preferable to use the same material and the same shape.

In the present invention, as shown in FIG. 3, the filter layer is formed of the filter cloth 7 and the spacer 40 (the above-described filtrate flow path material and supply liquid flow path material) without forming the filter cloth in an envelope shape. ) May be alternately stacked to form a filtration layer, and the filtration layer may be simply spirally wound. In this case, since it is not necessary to use an adhesive, there is no need to worry about eluted substances from the adhesive, and the element has a low elution as the element. Further, when the life of the element has expired, the filter cloth and the spacers of the flow path material can be easily reused by disassembling, so that the burden on the environment can be reduced.

These filter elements are provided with spacers between a required number of filter cloths cut to a predetermined length, and, if necessary, are sealed on three sides so that the filter cloths are formed in an envelope shape, and are wound around a central pipe. Formed. A temporary fixing tape for stopping the loosening is attached to the outer periphery of the filtration layer surrounded by the center pipe, and the center pipe is cut so as to have a specified length. Then, an end plate is provided and filament winding is performed.

The filtration module configured as described above is provided, for example, in a water treatment apparatus as shown in FIG. This water treatment apparatus includes a raw water tank 15, a raw water supply pump 16, and a filtration module 17 having the above-described configuration.
, A filtered water tank 18, a filtered water supply pump 20, and a membrane module 21. Raw water is raw water tank 1
From 5, the raw water is supplied to the filtration module 17 by the raw water supply pump 16, and coarse dust is removed by passing through the filtration layer of the filtration module. The filtered water from which coarse dust has been removed is temporarily stored in a filtered water tank 18, and further sent to a membrane module 21 by a filtered water supply pump 20, where bacteria and dissolved ions are removed by the membrane module 21,
It becomes purified water. This purified water is sent from the purified water line 22 to a use point.

In the filtration module 17, in the case of the filtration element shown in FIG. 2, raw water flows into the module case 1 from the raw water supply port 3 and flows to the filtered water outlet side, and at the same time, flows from the element outer circumference to the inner circumference. It passes through the filter cloth 7. The filtered water from which suspended and suspended substances have been removed by passing through the filter cloth is passed through the filtrate passage material 8.
To the central pipe 6 and is collected in the central pipe 6 through the water collecting hole. The filtered water is then sent from the end face of the center pipe 6 through the filtered water chamber 31 formed by the cylindrical spacer 30 and the filtered water outlet 4 to the next step. The center pipe 6 is directly connected to the filtered water outlet 4 and the filtered water outlet 4 is connected to the backwash water supply port and air outlet 5.
And the filtered water may flow directly from the center pipe 6 to the filtered water outlet 4.

On the other hand, in the case of the filtration element shown in FIG. 3, raw water flows into the module case 1 from the raw water supply port 3 as shown by the arrow in FIG. Flowing removes suspended and suspended solids. Initially, the raw water flows through the flow path formed by the spacers 40 with low resistance, but also passes through the filter cloth 7 when dirt is clogged or when a high flow rate of treated water is supplied.
The filtered water then collects from the end face of the filtering element into a filtered water chamber 31 formed by the cylindrical spacer 30;
It is sent to the next step through the filtered water outlet 4.

Then, when dirt accumulates on the filter cloth of the filter module 17 of FIG. 4 and the pressure difference between the supply pressure and the filter side pressure rises above a set value, the washing is performed. The washing is performed by opening the air pressure valve 23 to pressurize the filtered water stored in the filtered water tank 18 or sucking the filtered water using the backwash pump 19 and supplying the filtered water to the filtration module 17. . At this time, the water purification line valve 32 is closed so that the backwash water does not flow through the water purification line 22. The supplied filtered water flows into the module case 1 from the backwash water supply port / air outlet 5, and in the case of the filtration element of FIG. , To the filter cloth 7 and the supply liquid flow path material 9 in the direction opposite to that at the time of filtration. In this way, the clogged dirt and dust are pushed out of the system from the raw water supply port 3 through the drain valve 26. Also, in the case of the filtration element of FIG. 3, water is caused to flow in the direction opposite to the direction at the time of filtration, and dirt and dust are pushed out of the system via the raw water supply port 3 through the drain valve 26.

At this time, air is taken in from an air blowing valve 24 provided near the outlet of the backwash pump 19,
When cleaning is performed by supplying filtered water containing air to the filtration module 17, the flow rate of the cleaning water increases and the flow of the cleaning water becomes turbulent, so that cleaning can be performed effectively. Also,
From the viewpoint of cleanability, the cleaning pressure should be equal to or higher than the pressure difference between the supply pressure and the filtration side pressure, and the cleaning time should be within a range of 10 seconds to 3 minutes in order to reduce time loss and increase the cleaning effect. preferable. The frequency of backwashing depends on the raw water to be treated,
Once / one to 24 hours is common.

Since the filtration element and the filtration module of the present invention use a filter cloth, suspended substances and suspended substances can be prevented from clogging, and can be used as a front stage of a membrane module for treating highly turbid water or industrial waste water. Can be sufficiently removed. In addition, even if clogging occurs and pressure loss increases, backwashing can be performed, so that long-term repeated use is possible and running costs can be reduced. Also, in this backwashing, since the spacers are provided between the filter cloths, the backwash water is supplied to each of the filter cloths, so that the suspended and suspended substances that have been captured can be washed away. The performance as a filtration element can be fully recovered.

At the time of backwashing, it is preferable to supply backwashing water at a pressure equal to or higher than the pressure difference between the supply pressure during the filtration operation and the pressure on the filtrate side, but the outer periphery of the element is filled with an adhesive impregnated filament. By fixing the filament wind, form stability can be achieved and the element can be prevented from being damaged during filtration.

Further, since special production equipment such as a separation membrane is not required, the production can be performed with generally mass-produced industrial materials, so that the production cost can be reduced, and the fine delicate material such as a membrane can be obtained. Because it is not a structure, it has better durability than a membrane module.

[0026]

<Example 1> 34 filter cloths and 34 polyethylene spacers, respectively, and a perforated center pipe made of vinyl chloride were prepared.

The filter cloth is a standard tricot manufactured by Toray Industries, Inc., and has a length (width) of 970 m in the axial direction when the element is wound.
m, the thickness is 0.28 mm, the circumferential length (length) around the element is 679 mm and 693 mm, respectively, and 17 polyethylene spacers are used. The polyethylene spacer is TSX-313N manufactured by Mitsui Petrochemical Co., Ltd. 970m wide
m, thickness was 0.9 mm, and length was 686 mm and 701 mm, respectively.

The center pipe has an outer diameter of 32 mm, and
It had 200 φ4 holes.

First, one end of one 686 mm long polyethylene spacer is attached to the center pipe with a tape, and another 686 mm long polyethylene spacer is shifted on the polyethylene spacer so that the interval between the ends becomes 20 mm. And pasted with tape. Subsequently, a polyethylene spacer having another length of 686 mm was further stacked thereon and taped while being shifted so that the interval between the polyethylene spacer and the polyethylene spacer previously arranged was 20 mm. A total of 17 686 mm long polyethylene spacers
This was repeated until the sheets were stacked (A).

On the other hand, one end of a filter cloth having a length of 693 mm and one end of a filter cloth having a length of 679 mm are stuck together with a tape, and a gap between the two filter cloths stuck together and a length of 693 m is provided.
Then, a 701 mm long polyethylene spacer was attached to the filter cloth side of m (B). 16 sets of these were created.

Then, between the polyethylene spacers (A) attached to the center pipe, one set of the polyethylene spacers (B) attached between the tricots is arranged one by one, and the polyethylene spacers ( It fixed in the valley of A).

Around the center pipe, a length 693
mm filter cloth is spirally wound so as to be disposed on the outer peripheral side of the filter cloth having a length of 679 mm, and has an outer diameter of about 19 mm.
A 0 mm filtration element was produced.

Then, the filter cloth is temporarily fixed with tape so that the filter cloth does not come apart, and the center pipe is cut with a rotary blade so that the length becomes 936 mm, and the acrylonitrile / butadiene / styrene copolymer is cut. Coalescing (ABS)
A telescope prevention plate made of an adhesive (for example, Nagase & Co., Ltd. “Araldite” AW106 / Hardner HV95)
3U), glued to the center pipe, and further, a telescope prevention plate is fixed to the surrounding body with tape. Thereafter, a polyester filament assembly yarn impregnated with an adhesive (for example, Toray Industries, Inc., "Tetron" 1000-192-702)
In C), filament winding was performed so that the opening ratio became 90%, and the adhesive was cured.

One filter element thus manufactured was loaded in a special module case and installed as a pretreatment for a microfiltration membrane module of a lake water treatment apparatus (for example, “Trecube” manufactured by Toray Industries, Inc.). When the permeation flow rate of the microfiltration membrane module was operated at 1 (m / day), it took about 24
It took time.

At this stage, the differential pressure of the filtration module is 25
kPa, 200 L / min, 1
After performing backwashing for 1 minute, the differential pressure of the filtration module at the time of restarting was 20 kPa and returned to the initial value. Comparative Example 1 A microfiltration membrane module was operated at a permeation flow rate of 1 (m / day) in the same manner as in Example 1 except that the filtration module of the present invention was not used. Was about 8 hours to increase by 10 kPa. <Comparative Example 2> Cartridge filter (TCW-150 by Advantech Toyo Co., Ltd.) instead of the filtration module
-N-PPT) with 6 dedicated housings (6TK-3S-
NS) except that the microfiltration module was operated at a permeation flow rate of 1 (m / day) in the same manner as in Example 1 except that the differential pressure of the microfiltration membrane module was increased by 10 kPa. It was about 24 hours, which was almost the same as in the example.

However, at this stage, since the differential pressure of the cartridge filter was 106 kPa,
Backwashing was performed for 1 minute at L / min, but the differential pressure of the cartridge filter at the time of restart was 104 kPa, which was only 2 kPa lower than before the backwash. The initial pressure difference of the cartridge filter was 100 kPa.

[0037]

According to the present invention, a filter cloth is used, and the filter cloth and spacers are alternately laminated to form a filter layer. Suspended and suspended substances can be sufficiently removed before the membrane module that treats wastewater. Further, even if clogging occurs and pressure loss increases, backwashing can be performed and the performance as a filtration element can be sufficiently recovered, so that long-term repeated use is possible and running costs can be reduced. it can. In addition, since mainly mass-produced industrial materials are used, they can be manufactured at low cost, and the durability can be improved by filament winding.

[Brief description of the drawings]

FIG. 1 is a schematic partial cross-sectional view of a filtration module showing one embodiment of the present invention.

FIG. 2 is a schematic cross-sectional exploded view of a filtration element showing one embodiment of the present invention.

FIG. 3 is a schematic cross-sectional exploded view of a filtration element showing another embodiment of the present invention.

FIG. 4 is a schematic flow chart of a water treatment apparatus provided with the filtration module of the present invention.

[Explanation of symbols]

 1: Module case (cylindrical body) 2: End plate (for module case) 3: Raw water supply port 4: Filtration water outlet 5: Backwash water supply port and air outlet 6: Central pipe 7: Filter cloth 8: Filtrate Flow path material (spacer) 9: Supply liquid flow path material (spacer) 10: Telescope prevention plate 11: Filament 12: Plug 13: U seal 14: Filtration element 15: Raw water tank 16: Raw water supply pump 17: Filtration module 18 : Filtration water tank 19: Backwash pump 20: Filtration water supply pump 21: Membrane module 22: Water purification line 23: Air pressurization valve 24: Air blowing valve 25: Backwash line 26: Drain valve 30: Cylindrical spacer 31: Filtration water chamber 32: Water purification line valve

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01D 29/06 520E 520F 29/38 520A 510A 540 F term (Reference) 4D019 AA03 BA13 BB02 BB03 CA03 CB02 CB03 CB06 CB09

Claims (6)

[Claims] 1. A filter element, wherein a filter layer formed by alternately laminating filter cloths and spacers is spirally wound around a central pipe having a hole for collecting filtered water. 2. A filter layer formed by alternately laminating an envelope-shaped filter cloth containing a spacer therein and another spacer is spirally formed around a central pipe having a hole for collecting filtered water. A wound filtration element, wherein an opening of a filter cloth formed in an envelope shape faces a water collecting hole. 3. The filter fabric according to claim 1, wherein the filter fabric is a woven or knitted fabric.
Or the filtration element of 2. 4. The filter element according to claim 1, wherein the filter cloth is made of synthetic fibers. 5. A filtration module in which the filtration element according to claim 1 is housed in a cylindrical body having detachable end plates at both ends. 6. The filtration module according to claim 5, wherein one end plate is provided with a raw water supply port, and the other end plate is provided with a filtered water outlet and a backwash water supply port and an air outlet. .