WO2005042132A1

WO2005042132A1 - Fine filtering apparatus using flexible fiber filter module

Info

Publication number: WO2005042132A1
Application number: PCT/KR2003/002380
Authority: WO
Inventors: Ki-Baek Han; Myung-Gyoo Roh; Chul-Hee Cho; Sung-Ho Park; Sang-Woong Yoo; Sung-Hoon Lee; Sung-Kyu Hong
Original assignee: Nanoentech Co., Ltd.
Priority date: 2003-10-31
Filing date: 2003-11-07
Publication date: 2005-05-12
Also published as: KR100425907B1; AU2003277707A1; KR20030094150A

Abstract

A fine filtering apparatus using a flexible fiber filter module for treating sewage, foul water, wastewater, and drinking water is provided. In the filtering apparatus, the flexible fibers having proper surface roughness, flexibility, and elasticity as filter media are installed in the longitudinal direction of the apparatus, i.e., in the direction that filtering and backwashing are performed, and lower ends of the flexible fibers are fixed to a filter media fixing plate, and upper ends are not fixed so as to freely move according to flow of water and air. The apparatus and an efflux pipeline should always be fully filled, and filtering by the flexible fibers filled and a capillary phenomenon and a siphon phenomenon can be accomplished. Accordingly, the filtering apparatus tremendously improves filtration efficiency, the amount of clarified water, and backwashing efficiency, and reduces power consumption compared to a conventional filtering apparatus.

Description

FINE FILTERING APPARATUS USING FLEXIBLE FIBER FILTER MODULE

Technical Field The present invention relates to a filtering apparatus for treating sewage, foul water, wastewater, and drinking water. More particularly, the present invention relates to a fine filtering apparatus using a flexible fiber filter module, which tremendously improves filtration efficiency, the amount of clarified water, and backwashing efficiency, and reduces the power consumption compared to a conventional filtering apparatus. In the filtering apparatus, flexible fibers having proper surface roughness, flexibility, and elasticity are installed as filter media in the longitudinal direction of the apparatus, i.e., in the direction that filtering and backwashing are performed. Lower ends of the flexible fibers, to which clarified water, backwash source water, and backwash air are supplied, are fixed to a filter media fixing plate including source water and/or air supply holes. Upper ends of the flexible fibers are not fixed so as to freely move according to flow of water and air. The apparatus and an efflux pipeline should always be fully filled, and filtering by the flexible fibers tightly filled and a capillary phenomenon and a siphon phenomenon can be accomplished.

Background Art In general, wastewater, foul water, and sewage that contaminate the environment are first purified with first treated water, and then discharged into a river or sea. The first treated water and industrial water contain various suspended solids. The suspended solids are solid matters including particles (organics and inorganics) having the size of 0.1 micron or more and are also called suspended matters since they are held in suspension in water. Water containing suspended solids (suspended matters), i.e., first treated water and industrial water, are not proper for use as drinkable water for home or industrial use. Thus, filtering apparatuses for treating water which can save drinkable water and water resources and reduce energy by secondarily treating pretreated water have been developed. A conventional filtering apparatus having enhanced performance is disclosed in Korean Patent Registration No. 10-0354836 (Application No. 10-2001 -0013448 filed on March 15, 2001 , titled "Apparatus for filtering suspended solid in water). This apparatus uses fibers as filter media, fixed to one side end of the filtering apparatus so as to supply filter source water to the side of the apparatus, and air and backwash water are used for backwashing. However, the apparatus for filtering suspended solid in water is disadvantageous in that, since the filter source water is supplied from the side of the apparatus, a filtration resistance increases and turbulence by the backwash air does not occur smoothly, as well as some concentrated filtrate (or concentrated water) to be discharged when backwashing remains in the filtering apparatus and accumulates on the bottom of the apparatus. Another conventional fine filtering apparatus is disclosed in Korean Patent Registration No. 10-0367811 (Korean Patent application No. 10-2002-0044476 filed on July 27, 2002), in which flexible fibers having a specific flexibility and elasticity are installed in the longitudinal direction of the apparatus. However, a filter source water supply pipeline and a backwash water supply pipeline are separately installed so that the piping structure is complicated. Also, since separate equipment for replacing the filter media is not provided in the filtering apparatus, an operation for replacing the filter media is difficult.

Disclosure of the Invention To resolve the above and other problems, the present invention provides a fine filtering apparatus using a flexible fiber filter module, which can efficiently filter suspended solids contained in supplied water regardless of their kind, size, and state, backwash contaminants in the supplied water, and filter a large amount of water with low filtration resistance. The present invention also provides a fine filtering apparatus using a flexible fiber filter module, wherein flexible fibers as filter media are installed in the longitudinal direction of the filtering apparatus, and a filter media fixing plate in the form of a porous plate having source water and/or air supply holes for supplying source water and/or air is installed below the filter media so as to cause source water and air to wholly uniformly flow through the supply holes, thereby reducing access flow rate and utilizing a whole filter media layer as a space for water contaminants so as to reduce a filtration resistance and increase a filtration duration. The present invention also provides a fine filtering apparatus using a flexible fiber filter module, wherein a clarified water efflux unit (discharge unit) and a concentrated filtrate discharge unit have a dual jacket shape and the clarified water efflux unit is constructed such that the clarified water is discharged in different directions from side of a main body of the filtering apparatus, thereby reducing a resistance of the efflux unit to improve a filtration flux and smoothly discharge suspended solids entrapped by filter media during backwashing. The present invention also provides a fine filtering apparatus using a flexible fiber filter module, wherein flexible fibers are installed in the longitudinal direction of the filtering apparatus to filter and backwash such that lower ends of flexible fibers are fixed to a filter media fixing plate, which is installed below the main body of the filtering apparatus and has source water and/or air supply holes, and upper ends of flexible fibers are not fixed so as to maintain their flexibility, thereby increasing backwash efficiency and minimizing backwashing duration and the amount of backwash water. The present invention also provides a fine filtering apparatus using a flexible fiber filter module, which is constructed such that filter source water and/or backwash water supply pipeline and backwash air supply pipeline have the same supply direction so as to have a dual piping shape, thereby preventing backwash water from not being supplied due to air pressure when supplying backwash air during backwashing and preventing air from flowing backward to other filtration module. The present invention also provides a fine filtering apparatus using a flexible fiber filter module, the apparatus having simple and compact valves and pipings and using filter source water as backwash water so as to eliminate a treatment tank for backwash. The present invention also provides a fine filtering apparatus using a flexible fiber filter module, wherein flexible fibers made of polyamide, polyester, polypropylene, etc., having proper surface roughness, flexibility, and elasticity are used as filter media in the filtering apparatus, the thickness of the flexible fibers is adjustable according to the size of suspended solids in water to be removed, and the filter media are formed by coating and/or applying surfaces of the flexible fibers with absorbent materials so as to filter out particular contaminants (dissolved matters less than colloid, heavy metals, etc.) in water or by optochemically modifying the surfaces of the flexible fibers. The present invention also provides a fine filtering apparatus using a flexible fiber filter module, wherein a number of filtering devices are combined in parallel so as to treat a large amount of source water, thereby increasing throughput capacity. According to one aspect of the present invention, there is provided a fine filtering apparatus using a flexible fiber filter module, which is constructed such that a variety of suspended solids contained in supplied water are filtered through filter media formed of flexible fibers and suspended solids entrapped by the filter media are separated to be washed, the filtering apparatus including: a main body which is a main supply pathway of water and has the flexible fibers filled therein in the longitudinal direction of the filtering apparatus to perform filtration and backwash; supply pipelines in the form of a dual piping, which are installed at the end below the main body so as to supply water (filter source water and/or backwash source water) and backwash air; a filter media fixing plate which is installed below the main body, having a plurality of fixing holes capable of fixing the flexible fiber filter media and source water/air supply holes for uniformly supplying source water and/or backwash source water and backwash air arranged in the form of a regular triangle; a clarified water discharge jacket having a porous cylindrical member for discharging clarified water by the filter media to the outside of the main body at the side thereof and a closed outer cylindrical member covering the porous cylindrical member at the outside thereof for discharging clarified water from the porous cylindrical member to the outside of the main body through a predetermined efflux pipeline; and a concentrated filtrate discharge jacket formed of a closed outer cylindrical member having a jacket shape for discharging concentrated filtrate backwashed when backwashing to the outside of the apparatus through a predetermined efflux pipeline over the main body and covering the top of the main body at the outside thereof so as to discharge the concentrated filtrate backwashed to the outside of the main body, wherein lower ends of the flexible fibers are fixed to the filter media fixing plate whereas upper ends of the flexible fibers are freely left without being fixed to anywhere. The predetermined efflux pipeline related to the clarified water discharge jacket may include a connection pipeline connected to the lower portion of the clarified water discharge jacket and a clarified water efflux pipeline coupled with the connection pipeline by a lap joint. The predetermined efflux pipeline related to the concentrated filtrate discharge jacket may include a connection pipeline downwardly connected to the lower portion of the side of the concentrated filtrate discharge jacket and a concentrated filtrate efflux pipeline coupled with the connection pipeline by a lap joint. The filter source water and backwash water may be supplied through the supply pipeline such that filtration and backwash are performed in the same direction. During backwashing, the filter source water continuously supplied may be used as backwash water and backwash air intermittently supplied may produce a turbulence within the main body, wherein shearing stress generated by the turbulence facilitates separation of suspended solids (contaminants) entrapped by the filter media. During backwashing, air may be supplied through a plurality of air nozzles installed at a portion of the side of the main body as well as through backwash air supply holes in the lower portion of the filtering apparatus so as to facilitate separation of particles deposited to the filter media. The backwash air is generated by an air compressor, and stored as high pressure air in a storage tank, and then supplied during backwashing.

Brief Description of the Drawings FIG.1 shows a front structure of a fine filtering apparatus using a flexible fiber filter module according to the present invention; FIG. 2 shows a side structure of a fine filtering apparatus using a flexible fiber filter module according to the present invention; FIG. 3 shows a plan structure of a fine filtering apparatus using a flexible fiber filter module according to the present invention; FIG. 4 shows a structure of a filter media fixing plate having source water and/or air supply holes of a fine filtering apparatus using a flexible fiber filter module according to the present invention; FIG. 5 is an unfolded view of a porous cylindrical member for discharging clarified water of a fine filtering apparatus using a flexible fiber filter module according to the present invention; FIG. 6 shows a structure of a concentrated filtrate discharge jacket of a fine filtering apparatus using a flexible fiber filter module according to the present invention; FIG. 7 shows a structure of an air/backwash source water/filter source water supply unit at the lower portion of a fine filtering apparatus using a flexible fiber filter module according to the present invention; FIG. 8 shows a structure of a support table for a fine filtering apparatus using a flexible fiber filter module according to the present invention; FIG. 9 is a conceptional view for explaining the operation of a fine filtering apparatus using a flexible fiber filter module according to the present invention during filtration; FIG. 10 is a conceptional view for explaining the operation of a fine filtering apparatus using a flexible fiber filter module according to the present invention during backwashing; FIGS. 1 1 through 14 are graphs of results obtained using a fine filtering apparatus using a flexible fiber filter module according to the present invention, and more particularly, FIG. 1 1 is a graph showing a removal efficiency with respect to particle size of suspended solids in water, FIG. 12 is a graph showing a removal efficiency with respect to influx/efflux concentration of suspended solids with respect to an operating duration, FIG. 13 is a graph showing variations of pressure and filter flux with respect to an operating duration, and FIG. 14 is a graph showing a removal efficiency with respect to influx/efflux concentration of BOD with respect to an operating duration.

Best Mode for Carrying out the Invention The present invention will now be described more fully with reference to the accompanying drawings, in which embodiments of the present invention are shown. Referring to FIGS. 1 through 8, a fine filtering apparatus 100 using a flexible fiber filter module according to the present invention is constructed such that a variety of suspended solids contained in water are filtered out and the suspended solids entrapped by filter media formed of flexible fibers 9 are separated to be backwashed. The filtering apparatus includes: a main body 1 which is main supply pathway of supplied water (filter source water or backwash water) and has the flexible fibers 9 filled therein; a supply pipeline 2 of the filter source water and/or backwash source water, which is installed below the main body 1 so as to supply water (filter source water and/or backwash source water) from the outside to the main body 1 ; an air supply pipeline 3 in the form of dual piping, which is disposed within the filter source water and/or backwash source water supply pipeline 2 at the end below of the main body 1 so as to supply backwash air to the main body 1 when backwashing; a filter media fixing plate 8 which is installed below the main body 1 and having a plurality of filter media fixing holes 8b (see FIG. 4) capable of fixing the flexible fibers 9 as filter media and have source water/air supply holes 8a (see FIG. 4) for uniformly supplying source water and/or backwash air arranged in the form of a regular triangle; a clarified water discharge jacket 6 including a porous cylindrical member 6a for discharging clarified water by the flexible fibers 9 as filter media to the outside of the side of the main body 1 and a closed outer cylindrical member 6b covering the porous cylindrical member 6a at the outside thereof for discharging clarified water through the porous cylindrical member 6a outside through a predetermined efflux pipeline; and a concentrated filtrate discharge jacket 7 formed of a closed outer cylindrical member having a jacket shape and covering the main body 1 at the outside thereof for discharging concentrated filtrate backwashed to the outside of the apparatus through a predetermined efflux pipeline. The predetermined efflux pipeline related to the clarified water discharge jacket 6 may include a connection pipeline 4a in the form of arc, for discharging clarified water, which is connected to the lower portion of the clarified water efflux jacket 6 and a clarified water efflux pipeline 4b coupled with the connection pipeline 4a for discharging clarified water by using a lap joint as shown in FIGS. 1 through 3. Also, the porous cylindrical member 6a for discharging clarified water of the clarified water discharge jacket 6 may be formed in a portion of the main body 1 of the filtering apparatus. Similarly, the predetermined efflux pipeline related to the concentrated filtrate discharge jacket 7 may include a connection pipeline 5a for discharging concentrated filtrate, which is downwardly connected to the side of the concentrated filtrate discharge jacket 7, and a concentrated filtrate efflux pipeline 5b coupled with the connection pipeline 5a for discharging concentrated filtrate by a lap joint as shown in FIGS. 1 through 3. The concentrated filtrate may be discharged from the concentrated filtrate discharge jacket 7, which is formed of a closed outer cylindrical member having a jacket shape, over the main body 1 of the filtering apparatus. The concentrated filtrate discharge jacket 7 may be installed over the main body 1 and the clarified water discharge jacket 6 may be installed at the lower portion of the main body 1 than the concentrated filtrate discharge jacket 7 as shown in FIGS. 1 and 2. The clarified water is discharged in different directions from the main body 1 through the porous cylindrical member 6a for the clarified water discharge of the filtered discharge jacket 6, thereby minimizing an efflux resistance of clarified water and obtaining the highest amount of water treated. Lower ends of the flexible fibers 9 filled are fixed to the filter media fixing plate 8 which has the source water and/or air supply holes 8a and is fitted to lower flange 1 a of the main body 1 whereas upper ends are not fixed so as to maintain their flexibility. The upper flange corresponding to the lower flange 1 a is represented as reference numeral 1 b. Meanwhile, as shown in FIG. 8, the present invention provides a support table 1 1 for fixing the filtering apparatus 100; a bracket 13 for hanging the filtering apparatus and a U-bolt 12 which are disposed on the support table 1 1 and rotate the filtering apparatus 100 at an angle of 45° forward and backward when replacing the flexible fibers 9 to easily replace the flexible fibers 9. On the bracket 13 for hanging the filtering apparatus, the clarified water efflux pipeline 4b and the concentrated filtrate efflux pipeline 5b are coupled using a lap joint. Operation of the fine filtering apparatus using a flexible fiber filter module according to the present invention will now be described with reference to FIGS. 1 through 14. First, referring to FIGS. 1 through 3, in the fine filtering apparatus 100 using a flexible fiber filter module according to the present invention, the filter source water and/or backwash source water supply pipeline 2 through which source water including sewage, foul water, wastewater and drinking water is supplied, and the backwash air supply pipeline 3 are installed at the end below the main body 1 in the form of a dual piping, i.e., in the form that the backwash air supply pipeline 3 is disposed within the source water supply pipeline 2. The lower ends of the flexible fibers formed of polyamide, polyester, polypropylene, etc., are fixed to the filter media fixing holes 8b formed in the fixing plate 8, which is installed below the main body 1 and also includes the source water and /or air supply holes 8a. Meanwhile, the upper ends of the flexible fibers 9 are not fixed so as to maintain their flexibility. Referring to FIG. 4, in the filter media fixing plate 8, the filter media fixing holes 8b for fixing one end of the flexible fibers 9 and the source water and/or air supply holes 8a for uniformly supplying source water and backwash source water and backwash air are preferably arranged in the form of a regular triangle. As described above, the clarified water discharge jacket 6 and the concentrated filtrate discharge jacket 7 are disposed at the upper portion of the filtering apparatus 100. These jackets 6 and 7 are in the form of dual jacket, respectively. The clarified water discharge jacket 6 includes a porous inner cylindrical member 6a for discharging the clarified water and a closed outer cylindrical member 6b for discharging the clarified water. The concentrated filtrate discharge jacket 7 has a closed outer cylindrical structure such that the concentrated filtrate generated during backwashing is discharged while being overflowed over the main body 1. The porous cylindrical member 6a for discharging clarified water has a plurality of clarified water discharge holes 6c. Due to the clarified water discharge holes 6c, the clarified water is discharged in different directions from the main body 1. As a result, the efflux rate of the clarified water is reduced and the filtration pressure is minimized. The concentrated filtrate discharge jacket 7 is disposed over the clarified water discharge jacket 6, i.e., on the top of the filtering apparatus 100. In order to enhance a separation effect (backwash effect) of the particles deposited in the filter media during backwashing, the backwash air supply pipeline 3 for supplying air is installed below the main body 1 and a plurality of air supply nozzles 10 may be formed at the side of the main body 1 to supply air. Meanwhile, the fine filtering apparatus 100 using a flexible fiber filter module according to the present invention is placed on the support table 1 1 as shown in FIG. 8. The support table 1 1 can fix the filtering apparatus 100 and provide maintenance convenience, for example, when replacing the flexible fiber filter media 9. The bracket

13 for hanging the filtering apparatus is installed on the support table 1 1 in order to replace the flexible fiber filter media 9. The clarified water efflux pipeline 4b and the concentrated filtrate efflux pipeline 5b are mounted on the bracket 13 for hanging the filtering apparatus so that the filtering apparatus 100 has the center of gravity on the support table 1 1 . In a general operation, the filtering apparatus100 is fixed with the U-bolt 12 for fixing the filtering apparatus and during maintenance the U-bolt 12 for fixing the filtering apparatus is separated, so that the filtering apparatus 100 can be moved freely forward and backward. FIG. 9 shows the operation of the filtering apparatus of the present invention during filtration and FIG. 10 shows the operation of the filtering apparatus of the present invention during backwashing. Referring to FIG. 9, during filtration the filter source water is supplied by a pump

P and the clarified water discharge valve V1 connected to the clarified water efflux pipeline 4b is opened. As a result, the filter source water of filter source water tank 52 is supplied to the filtering apparatus 100 and upstream filtration is performed. The clarified water which is clarified by the filtering apparatus 100 is flowed to the clarified water storage tank 54 via the clarified water discharge jacket 6 and the clarified water discharge valve V1. During a filtration process, the backwash air valve V2 and the concentrated filtrate discharge valve V3 are kept in closed state. More specifically, the suspended solids in the filter source water (suppy water) are entrapped by the filter media while passing through the filter media formed of flexible fibers 9 by various mechanisms of sieve filtration, physiochemical adsorption, isolation, precipitation and the like. The clarified water in which the suspended solids are removed is flowed to a clarified water storage tank 54 via the clarified water discharge jacket 6 and the discharge valve V1. As the filtration process is continuously performed, the amount of the suspended solids entrapped by the filter media 9 increases, so that the filtration resistance is increased and the filtration flux is lowered. Accordingly, the amount of the clarified water is decreased. When the amount of clarified water is decreased less than the desired amount of water or the filtration pressure is higher than the set value or previously set filtration duration is completed, backwashing is initiated. Referring to FIG. 9, during backwashing, the clarified water discharge valve V1 is closed and the backwash air valve V2 and the concentrated filtrate discharge valve V3 are opened. Meanwhile, since the filter source water contained in the filter source water tank 52 is used as backwash water, the filter source water and/or backwash source water supply pump P is continuously operated. During backwashing, the filter media 9 in the filtering apparatus 100 swells horizontally and vertically and is spontaneously strongly shaken due to high pressure air supplied to the filtering apparatus 100 through an air compressor 62 and an air storage tank 64 and the backwash water supplied to the filtering apparatus 100 through the filter source water and/or the backwash water supply pump P. Due to the swelling and shaking of the filter media 9, turbulence occurs,^" which induces shearing stress. As a result, the particulates (suspended solids) entrapped by the filter media 9 are separated within a short period of time. The suspended solids separated from the filter media 9 are mixed in the backwash water to form backwash concentrated filtrate. The backwashed concentrated filtrate is flowed to the concentrated filtrate storage tank 56 via the concentrated filtrate discharge jacket 7 and the concentrated filtrate discharge valve V3. During backwashing, the high pressure air generated by the air compressor 62 is preferably stored in the air storage tank 64, and then the stored high pressure air is periodically supplied into the filtering apparatus 100. As a result, the backwash process can be efficiently performed. During backwashing, the filter source water contained in the filter source water tank 52 as described above is preferably used as backwash water, but backwash water stored in a separate tank may also be used. When the filter source water stored in the filter source water tank 52 is used as backwash water, a separate backwash water tank, a valve, and other piping for supplying the backwash water are not required. Thus, the constitution of the filtering apparatus becomes simpler. Meanwhile, the source water supply pipeline 2 and the air supply pipeline 3 are shown as one pipeline in FIGS. 9 and 10 in order to simplify the figures. Hereinafter, the filtering apparatus of the present invention will further be described with reference to the following Experimental Example.

Experimental Example - Sewage treatment The filtering apparatus according to present invention having a diameter 1500 mm and a length 3000 mm was installed in a sewage disposal plant and operated for six months. As a result, the average concentration of the solid substance (SS) in water was 8.4 ppm and the average concentration of SS in efflux water was 0.7 ppm and was maintained at 1 ppm or less. Also, the output efficiency was 91 % on average. As a result of investigating a distribution of the particle size of the suspended solids in the efflux water and the influx water, removal efficiencies of 68%, 78%, 81 % and 90% were obtained for particle sizes of 1-3 μm, 3-5 μm, 5-8 μm and 8 μm, respectively. In the sewage or foul water biologically treated, 70% or more of BOD in the efflux water was solid BOD, indicating that when removing the suspended solids in water, BOD was removed too. Accordingly, an average influx BOD of 8.2 ppm, an average efflux BOD of 3.2 ppm and an average removal rate of 61 % were obtained. FIGS. 1 1 through 14 illustrate the results of the Experimental Example. FIG. 1 1 is a graph showing the removal efficiency with respect to the particle size of the suspended solid, FIG. 12 is a graph showing the removal efficiency with respect to influx/efflux concentration of the suspended solid in water with respect to the operating duration, FIG. 13 is a graph showing variations of pressure and filtration flux with respect to the operating duration, and FIG. 14 is a graph showing removal efficiency with respect to influx/efflux concentration of BOD with respect to the operating duration.

Industrial Applicability As described above, a fine filtering apparatus using a flexible fiber filter module according to the present invention tremendously improves filtration efficiency, the amount of clarified water, and backwashing efficiency, and reduces power consumption compared to a conventional filtering apparatus. In the filtering apparatus, flexible fibers having proper surface roughness, flexibility, and elasticity are installed in the longitudinal direction of the apparatus and lower ends of the flexible fibers are fixed to a filter media fixing plate having source water and/or air supply holes, and upper ends are not fixed so as to maintain the fibers' flexibility according to flow of water and air. The apparatus and a supply pipeline should always be fully filled, and filtering by the flexible fibers filled and a capillary phenomenon and a siphon phenomenon can be accomplished.

Claims

What is claimed is: 1. A fine filtering apparatus using a flexible fiber filter module, which is constructed such that a variety of suspended solids contained in supplied water are filtered through filter media formed of flexible fibers and suspended solids entrapped by the filter media are separated to be washed, the filtering apparatus comprising: a main body which is a main supply pathway of water and has the flexible fibers filled therein in the longitudinal direction of the filtering apparatus to perform filtration and backwash; supply pipelines in the form of dual piping, which are installed at the end below the main body so as to supply water including filter source water and/or backwash source water and backwash air from the outside to the main body; a filter media fixing plate which is installed below the main body, has a plurality of fixing holes capable of fixing flexible fiber filter media and source water/air supply holes for uniformly supplying source water and/or backwash source water and backwash air arranged in the form of a regular triangle; a clarified water discharge jacket including a porous cylindrical member for discharging clarified water by the filter media to the outside of the main body and a closed outer cylindrical member covering the porous cylindrical member at the outside thereof for discharging clarified water from the porous cylindrical member to the outside through a predetermined efflux pipeline; and a concentrated filtrate discharge jacket formed of a closed outer cylindrical member having jacket shape for discharging concentrated filtrate backwashed when backwashing to the outside of the apparatus through a predetermined efflux pipeline over the main body and covering the top of the main body at the outside thereof so as to discharge of the concentrated filtrate backwashed to the outside of the main body, wherein lower ends of the flexible fibers are fixed to the filter media fixing plate and upper ends of the flexible fibers are free.

2. The filtering apparatus of claim 1 , wherein the predetermined efflux pipeline related to the clarified water discharge jacket includes a connection pipeline which is connected to the lower portion of the clarified water discharge jacket and a clarified water efflux pipeline coupled with the connection pipeline by a lap joint, and the porous cylindrical member of the clarified water discharge jacket is formed in the main body.

3. The filtering apparatus of claim 1 , wherein the predetermined efflux pipeline related to the concentrated filtrate discharge jacket includes a connection pipeline which is downwardly connected to the side of the concentrated filtrate discharge jacket and a concentrated filtrate efflux pipeline coupled with the connection pipeline by a lap joint and the inner cylindrical member of the concentrated filtrate discharge jacket is formed on the top of the main body and the closed outer cylindrical member is formed over the inner cylindrical member in the form of a jacket.

4. The filtering apparatus of claim 1 , wherein the concentrated filtrate discharge jacket is installed over the main body and the clarified water discharge jacket is installed below the concentrated filtrate discharge jacket.

5. The filtering apparatus of claim 1 , wherein the filter source water and backwash water or backwash air are supplied through supply pipelines and filtration and backwash are performed in the same direction upwardly in the main body.

6. The filtering apparatus of claim 1 , wherein during backwashing the filter source water continuously supplied is used as backwash water and the backwash air intermittently supplied creates a turbulence in the main body, and shearing stress generated by the turbulence facilitates separation of the suspended solids entrapped by the filter media.

7. The filtering apparatus of claim 1 , wherein the quality of the clarified water is controllable according to a filtration density of the flexible fibers, filtration flux, and thickness of the flexible fiber.

8. The filtering apparatus of claim 1 , wherein air is supplied through a plurality of air nozzles at the side of the main body as well as from the lower portion of the main body to facilitate separation of the suspended solids entrapped by filter media.

9. The filtering apparatus of claim 1 , further comprising a support table for fixing the filtering apparatus, on which a bracket for hanging the filtering apparatus is installed, and the clarified water efflux pipeline and the concentration efflux pipeline are coupled by a lap joint on the bracket.