JPH11235503A - Support structure for filter using planar filter medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enlarge the flow velocity of a water stream at the time of a filter treatment capable of coping with the treatment of high load raw water and exhibiting a straightening effect without the uneven distribution of flow passages, to hardly cause clogging and to make the washing possible. SOLUTION: In a supporting structure for a water treatment filter using a planar filter medium 2, the planar filter medium 2 is supported by a perforated holding body 1 formed into a honeycomb shape by alternately joining planar metal foils and corrugated metal foils. The perforated holding body 1 is arranged on one side of downstream of the planar filter medium 2 such as a nonwoven fabric or on the both sides of the upstream and the downstream hereof. In this way, since the planar filter medium of small physical strength (the nonwoven fabric or a flat membrane) can be supported by the supporting structure of the perforated holding body of large porosity, a pressure loss due to the supporting structure at the time of the filter treatment is hardly caused. Therefore, the permeated quantity per unit area by two or more times than that of the conventional one can be obtained under the low pressure of about several kg/cm<2> and the treatment of high load raw water can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter support structure using a planar filter such as a nonwoven fabric or a flat membrane.

[0002]

2. Description of the Related Art Conventionally, a filtration process has been used as a solid-liquid separation method in water treatment. In recent years, a non-woven fabric, a microfiltration membrane which is a flat membrane,
The use of flat ultrafiltration membranes is increasing. But,
Nonwoven fabrics, microfiltration membranes, and the like have low physical strength, and when pressure is directly applied to these planar shapes and filtration is performed, the nonwoven fabrics and flat membranes are easily damaged at a pressure of about several kg / cm ² . For this reason, the membrane is reinforced so as not to be damaged by a relatively high pressure. This reinforcing method uses, for example, an aligned perforated plate 8 having holes arranged in a resin plate or a metal plate (punched metal) as shown in FIG. For example, a random perforated plate 9 composed of randomly arranged water-permeable holes made of a resin plate or a foam concrete plate may be used.

[0003]

Since the perforated plate 8 (FIG. 8) has a small porosity of 30 to 50% and a large hole diameter, the filter (non-woven fabric 7) as shown in FIG. The flow of the treated water that permeates through the pores is biased toward the holes, so that a uniform flow (rectification) cannot be obtained, and the filtration performance of the filtration material cannot be sufficiently exhibited. Further, in the case of the random perforated plate 9 (FIG. 9), since the aperture ratio is smaller than the former and the flow path is formed by foaming, as shown in FIG. The pressure loss due to the flow resistance increases and the processing capacity is low. In addition, clogging is likely to occur due to the flow path, and it is also difficult to remove clogged impurities.

[0004] The present invention has been made in view of the above-mentioned problems of the prior art, and reduces the pressure loss at the time of filtration processing.
An object of the present invention is to provide a filter support structure using a planar filter, which increases the throughput per unit time and makes it difficult to cause drift, clogging, and the like.

[0005]

In order to achieve the above object, a support structure for a filter using a planar filter according to the present invention is a support structure for a water treatment filter using a planar filter. The plate-like metal foil and the corrugated metal foil are alternately joined to each other, and the sheet-like filter material is supported by a porous holder formed in a honeycomb shape. The porous holding member is disposed on one side of the downstream in contact with the sheet filter material or on both the upstream and the downstream sides. A nonwoven fabric or a flat membrane can be used as the planar filter. Here, the flat membrane is a flat membrane of a microfiltration membrane or an ultrafiltration membrane used for water treatment.

The support structure of the filter of the present invention is a structure in which a metal foil is supported by a porous holder formed in a honeycomb shape. The porous holder has an opening having a linear shape in a direction (water flow direction) perpendicular to the surface supporting the planar filter material, that is, the same cross-sectional shape along the water flow direction. The porosity can be increased. Therefore, in the porous holding body of the present invention, pressure loss is small, the flow path is not locally localized, and rectification is not hindered. Also, clogging hardly occurs, and even if clogging occurs,
It can be easily eliminated by injection of relatively low pressure water or air. Here, the porous holder has a thickness of 20 to 1
Using a stainless metal foil of 00 μm, a plate-shaped metal foil and a corrugated metal foil made of such a metal foil are alternately joined to form a honeycomb shape. The opening ratio (= opening area / total cross-sectional area) of the honeycomb structure of the porous holder used in the present invention is 70 to 95.
% Is preferred. The value of 70% or more is for generating and maintaining rectification, and the value of 95% or less is for securing strength as a support structure. Incidentally, in the case of a conventional punching metal, the porosity is about 30 to 50%, and in the case of a foamed resin plate or foamed concrete, the porosity is even smaller. The size of the opening of the honeycomb structure of the present invention is:
The diameter (D) of the circle inscribed in the opening shown in FIG. 7B is preferably in the range of 0.4 to 3.0 mm. 0.4mm
Is determined from the manufacturing point of forming the metal foil into the honeycomb structure, and the value of 3.0 mm is for securing the supporting strength. The thickness (length in the water flow direction) of the honeycomb structure is determined based on the relationship with the flow path area (diameter), and is usually preferably about 10 to 50 mm.
If the diameter is smaller than 10 mm, the supporting strength for supporting the filter becomes weak, and if the diameter is 50 mm, the rectifying effect is sufficient.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. In FIG. 1, the porous holder 1
Thus, the planar filter medium 2 such as a nonwoven fabric or a flat membrane is supported from one side downstream of the water flow. Raw water flows continuously from the left to the right inside the container 3, and is filtered by the planar filter 2. In FIG. 2, a nonwoven fabric,
A planar filter medium 2 such as a flat membrane is supported from one side of the upstream and downstream of the water flow. Raw water flows continuously from the left to the right inside the container 3, and is filtered by the planar filter 2. The porous holder 1 can support the planar filter medium 2 from both sides without impairing rectification. With the two-sided support, the filter can be reliably supported even when the water flow is in the opposite direction. In FIG. 3, a planar filter material 2 such as a nonwoven fabric or a flat membrane is continuously adhered to the outside of the porous holder 1. The raw water continuously passes through the porous holder 1 from the outer surface of the sheet filter medium 2, and is discharged from the pressure vessel 4 after impurities are removed. A pipe (not shown) having an air discharge hole is provided below the planar filter medium 2, and impurities adhered to the surface of the planar filter medium 2 can be removed by bubbling by blowing air. .

FIG. 4 shows an example in which the installation portion of the porous holder 1 is expanded as a method for reducing the pressure difference caused by the porous holder 1. In FIG. 5, as a method for reducing the pressure difference caused by the porous holder 1, the installation portion of the porous holder 1 is a branch pipe. In FIG. 6, raw water continuously flows in from an inlet 5 of a pressure vessel 4, passes through two planar filter media 2 and a porous holder 1 in parallel, and flows out of an outlet 6.

FIG. 7 shows the structure of the porous holder 1 of the present invention. The honeycomb-shaped porous holding body 1 is formed by alternately joining a plate-shaped metal foil 1a made of a corrosion-resistant metal such as stainless steel and a corrugated metal foil 1b into a honeycomb shape. The plate-shaped metal foil 1a and the corrugated metal foil 1b are overlapped, joined by brazing, spot welding and the like, and laminated. The entire shape of the honeycomb-shaped porous holding body 1 can be rectangular, circular, polygonal, or the like in accordance with the shape of the pipe 2 through which the raw water passes.

[0010]

An embodiment of the present invention will be described. (Example 1) A planar filter medium 2 was prepared using the porous holder 1 shown in FIG.
This is an example in which a nonwoven fabric is supported, and was carried out under the following conditions. The inner diameter of the container 3 is 194 mm, and the honeycomb-shaped porous holding body 1 installed for supporting the planar filter medium 2 in the water flow path in the container 3 has a diameter of 193 mm, a porosity of 94%,
The hole diameter (diameter of a circle inscribed in the opening) is 1.0 mm, and the thickness (length of the porous holder 1 in the water flow direction) is 17 mm. Raw water containing impurities was treated by the planar filter medium 2 supported by the porous holder 1, and impurities having a size of 10 μm or more were effectively removed, and water treatment was possible. According to this example, the unit area (1 cm ² ) of the planar filter medium 2 (nonwoven fabric) and the unit pressure (1 kg / cm) of the pressure difference (differential pressure) between the entrance side of the planar filter medium 2 and the exit side of the porous holder 1 ² ) Conversion amount 2.5 × 10 ^-6
Raw water treatment at m ³ / sec was possible, and there was no clogging. When this result is compared with the case of the punching metal, the throughput is 1.7 × 1 according to the punching metal.
0 ^-6 m ³ / sec. According to the present invention, it was possible to significantly reduce the pressure loss and increase the throughput.

(Embodiment 2) The porous holder 1 shown in FIG.
This is an example in which a flat membrane is supported before and after as the planar filter medium 2, and was carried out under the following conditions. The inner diameter of the container 3 is 194 mm, and the honeycomb-shaped porous holder 1 installed to support the planar filter medium 2 in the water flow path in the container 3 has a diameter of 193 m.
m, opening ratio 94%, hole diameter (diameter of circle inscribed in opening)
1.6 mm, thickness (length of porous holder 1 in water flow direction) 1
7 mm. Raw water containing impurities was treated by the planar filter medium 2 supported by the porous holder 1, and impurities having a size of 10 μm or more could be effectively removed and water treatment was performed. According to this example, the unit area (1 cm
^2), unit pressure of the ingress and the porous carrier a pressure difference of the outgoing side of the first planar filter medium 2 (differential pressure) (1 kg / cm ² in terms of) the processing amount 1.9 × 10 ^-6 m ³ / The raw water treatment could be performed for sec, and there was no clogging. When this result is compared with a conventional perforated plate, the throughput is 1.2 × 10 ⁻⁶ according to the perforated plate.
m ³ / sec, and the present invention was able to significantly reduce the pressure loss and increase the throughput.

[0012]

(1) According to the present invention, a planar filter medium (nonwoven fabric or flat membrane) having a small physical strength can be supported by a support structure of a porous holding member having a large porosity. Since almost no pressure loss occurs due to this support structure during treatment, the permeation amount per unit area more than twice that of the conventional method can be obtained with a pressure as low as several kg / cm ² , enabling the treatment of high-load raw water. And (2) Since the planar filter medium is supported by a porous structure having a honeycomb structure with a large porosity, the flow path of water is not locally localized at the time of the filtration process, thereby preventing unrectification. Clogging can be suppressed in the filter medium. Even if clogging occurs, the degree of the clogging is lighter than in the related art, so that the contaminants adhering to the planar filter can be easily removed by washing the planar filter. In addition, clogging hardly occurs in the support structure itself of the porous holder having a honeycomb structure, and contaminants adhered to the porous holder can be easily removed. In the case where the planar filter medium is supported by arranging a porous holder on both the upstream and downstream sides, the porous holder on the upstream side does not hinder rectification of water and does not cause clogging, Excellent as a support structure for planar filter media. Further, the present invention can easily be applied to a case where a filtering process is performed on a water flow in a direction opposite to the normal direction. (3) From this, the long-term operation of the surface filter media
Not only the reliability of the filtration is increased, but also the area of the required planar filter material can be reduced. In addition, maintenance becomes easier.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an embodiment of the present invention.

FIG. 2 is a view for explaining an embodiment in which a porous holding body is installed in front and behind in the present invention.

FIG. 3 is a diagram for explaining another embodiment of the present invention.
(B) is a sectional view taken along line AA of (A).

FIG. 4 is a diagram illustrating an embodiment in which a widened portion is provided in the present invention.

FIG. 5 is a diagram illustrating an embodiment in which a branch pipe is provided in the present invention.

FIG. 6 is a diagram illustrating another embodiment of the present invention.

FIG. 7 is a diagram illustrating a honeycomb structure of the porous holding body of the present invention. (B) is a partially enlarged view of the honeycomb structure of (A).

FIG. 8 is a diagram illustrating a conventional technique (aligned perforated plate). (A) is a perspective view of the aligned perforated plate, and (B) is a cross-sectional view of a support structure using the aligned perforated plate.

FIG. 9 is a diagram illustrating another conventional technique (random perforated plate). (A) is a perspective view of a random porous plate, and (B) is a cross-sectional view of a support structure using the random porous plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Porous holder 2 Planar filter material 3 Container 4 Pressure vessel 5 Inlet 6 Outlet 7 Nonwoven fabric 8 Aligned perforated plate 9 Random perforated plate

Claims (3)

[Claims] 1. A support structure for a water treatment filter using a sheet filtration material, wherein a sheet-like metal foil and a wave-like metal foil are alternately joined to form a honeycomb-like porous holder. A filter support structure using a planar filter material, wherein the filter material is supported. 2. The support structure for a filter using a planar filter according to claim 1, wherein a porous holding member is disposed on one side of the downstream side or on both the upstream side and the downstream side adjacent to the planar filter. 3. The support structure for a filter using a planar filter according to claim 1, wherein the planar filter is a non-woven fabric or a flat membrane.