KR101781496B1

KR101781496B1 - Multi-stage Filtering Apparatus and Filtering Method

Info

Publication number: KR101781496B1
Application number: KR1020150105789A
Authority: KR
Inventors: 이우녕; 박성원; 박용해
Original assignee: 두산중공업 주식회사
Priority date: 2015-07-27
Filing date: 2015-07-27
Publication date: 2017-09-25
Also published as: KR20170013000A

Abstract

The present invention relates to a multi-stage filtration apparatus and a filtration method, and more particularly, to a multi-stage filtration apparatus and filtration method which are formed in multiple stages to reduce the occupied space and improve the filtration performance by sequentially filtering the raw water by each stage of the filter medium. .

Description

TECHNICAL FIELD [0001] The present invention relates to a multi-stage filtering apparatus and a filtering method,

Suspended Solids (Suspended Solids) are usually used to refer to small particle components of 0.1μ or more contained in water. When they are contained in large amounts in water, they cause severe turbidity and cause increase of BOD and COD. These suspended solids are contained in most water, such as water washed by rainwater, plankton propagating in the reservoir, or municipal sewage or factory wastewater. Sewage containing a large amount of suspended solids is a contaminant that must be removed because it accumulates in the pipeline and interferes with the flow of water and organic matter deposited can deteriorate the water quality.

On the other hand, suspended matter exists in a state slightly larger than the colloid component when classified into particle size, and is floating in water contrary to the dissolved substance. The sedimentation rate is very late because the sedimentation rate is very low, although the sedimentation of the suspended material component occurs after a certain period of time. However, in order to remove the suspended matters contained in the water, the aggregation agent is used to aggregate the particles, , It is common to remove by sedimentation or flotation method or to remove a small amount of suspended matter component by using filter medium

Typically, during the filtration, the suspended material is filtered through the filter material, and the filtration process proceeds. However, when a certain period of time passes, the suspended material accumulates between the filter materials, resulting in the blocking of the filter material. In this case, it is necessary to remove the suspended matter trapped between the filter media by backwashing, as opposed to the filtration direction. However, frequent backwash results in the loss of filter media, and when general filter media such as sand are used, some of the filter media is broken by the backwash process. In severe cases, the filtration tank is closed or the frequency of filter media replacement becomes frequent Which causes deterioration of water quality and increase of maintenance cost. In addition, the general backwashing method using the treated water is not only difficult to efficiently backwash, but also has a disadvantage in that a large amount of backwashing is generated and a lot of processing cost is required to reprocess it.

The filtration system is a device that filters contaminated raw water through filtration material and supplies it as clean treated water. It is widely used not only for drinking water but also for treatment of water, sewage and factory water. Particularly, the filtration apparatus used for the treatment of river water or factory wastewater or the desalination plant of seawater is gradually becoming larger in order to increase the water quantity to be treated and to improve the water quality.

In order to improve the treatment speed and improve the water quality, a plurality of filters are disposed. In such a case, the occupied space or the installation space becomes very large, There is a problem.

On the other hand, in the past, sand or anthracite coal has been used as a filter medium in filtration apparatuses. However, due to problems such as confinement of floating substances in the vicinity of the surface layer, easy clogging, (Dual Media Filter) have been developed.

However, in the case of the multi-layer filter media, there is a problem that it is difficult to achieve the filtration effect according to the multi-layered structure, because the filter media are substantially densely packed and formed as a lump.

In general, there is a need to develop a filtration device capable of efficiently performing backwashing while effectively removing suspended solids, and economically and efficiently filtering while reducing the occupied space.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and its object is to provide a multi-stage filtration apparatus and a filtration method which are formed in multiple stages to reduce occupied space and raw water is sequentially filtered by each stage filter material, .

It is still another object of the present invention to provide a multi-stage filtration apparatus and filtration method using an apparatus for mixing and coagulating suspended solids with a flocculant in advance in order to improve filtration efficiency of the filtration apparatus.

It is still another object of the present invention to provide a multi-stage filtration apparatus and a filtration method capable of enhancing the efficiency of removing contaminants in the fiber ball filter media during backwashing.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a multi-stage filtration apparatus comprising: And a filter material formed at each end of the container, wherein the raw water introduced through the raw milk inlet pipe connected to the upper end side wall of the container passes through the filter layer at each end from the upper end to the lower end, Passes through the filtration layer at the last stage, and exits through the filtrate discharge pipe connected to the last stage.

At this time, it is preferable that a backwash inlet pipe through which the backwash water or the backwashing air is inputted is provided at each end except the uppermost end of the container, and a flange for inputting and discharging the filter medium is installed at each end of the container Do.

In addition, it is preferable that a filter upper space is provided at each end of the container and a height of the filter upper space is equal to or greater than a height of the filter layer.

A plurality of strainer nozzles are coupled to the lower surface of each of the stages and a circulating flow is supplied to the filter media during backwashing to mix the filter media together. It is preferable to further provide the above.

Meanwhile, a multi-stage filtration method according to an embodiment of the present invention is a multi-stage filtration method using a container composed of two or more stages and a filter material forming a filtration layer at each end of the container, An inflow step of inflow of raw water through infant feeding entrance; A filtration step of flowing the introduced raw water through the filtration layers at the respective stages from the uppermost stage to the lower stage to the lower stage; And a treated water discharge step of discharging the treated water having passed through the filtration layer at the last stage through a filtered water discharge pipe connected to the last stage.

At this time, it is preferable that a flange is provided at each end of the container, and the filtering material is injected through the flange to perform filtration. At each end of the container, there is a filter material upper space and a height of the filter material upper space is It is preferable to carry out filtration in a condition of being equal to or greater than the height.

In addition, it is preferable that before the introduction step, a pretreatment step of promoting miscibility agglomeration of a foreign substance by using an agglomerate agglutination device provided at an uppermost end of the container.

Meanwhile, the backwashing method using the multi-stage filtration apparatus of the present invention comprises the steps of: inputting backwash water through at least one of backwash oil inlet of each stage except the uppermost stage; A backwashing step of removing foreign matters in the filter media while passing the injected backwash water through the strainer nozzles and the filtration layers at the respective stages from the input end to the upper end direction; And a backwash water discharge step of discharging the backwash water containing the foreign matter through a raw water inlet connected to the uppermost stage.

In this case, it is preferable to further include a filter material pressing step of removing the water in the filter material after passing the backwash water through the filtration water discharge pipe connected to the last end, passing the backwash water from the upper end to the lower end.

According to the multistage filtration apparatus of the embodiment of the present invention, the raw water is primarily filtered by the filter material in the upper end, and sequentially filtered by the filter material in the lower end to elongate the filtration path, So that the filtration performance is improved.

Further, since each stage is constituted in one container, the occupied space is reduced. Further, a strainer nozzle is provided on the lower surface of each lower end, and a circulating flow is supplied to the filter material at the upper end during backwashing, so that the filter materials are mixed with each other, thereby effectively performing backwashing.

In addition, a device for promoting agglomeration of the filtration material at the uppermost end of the container can be installed to more effectively remove suspended matters in the raw water. Further, the filtration efficiency is improved by performing filtration in a state where the height of the filter medium upper space at each end is equal to or greater than the height of the filtration layer.

Also, there is an effect of increasing the filtration efficiency by introducing the backwash water through the inlet of each stage except for the uppermost stage, and removing the remaining foreign matter in the filtration media while passing the backwash water through the filtration layers at each stage.

There is also an effect of improving the filtration efficiency by discharging residual backwash water remaining in the container from which the foreign matter has been removed and pressing the filter material.

1 is a cross-sectional view of a multi-stage filtration apparatus according to an embodiment of the present invention.
2 is a cross-sectional view of a fiber ball filter material according to an embodiment of the present invention.
3 is a plan view of a lower surface of a lower end according to an embodiment of the present invention.
4 is an operation diagram of a filtration process of the multistage filtration apparatus according to an embodiment of the present invention.
FIG. 5 is a partial action diagram of back-flushing of a multi-stage filtration apparatus according to an embodiment of the present invention.
6 is an operation diagram of a compression process for a filter medium of a multi-stage filtration apparatus according to an embodiment of the present invention.
7 is a cross-sectional view of a multi-stage filtration apparatus including a non-powered agitation coagulation apparatus according to an embodiment of the present invention.
8 is a cross-sectional view schematically showing a cross section of AA 'of a filtration apparatus including a non-powered agitation coagulation apparatus according to an embodiment of the present invention.
9 is a cross-sectional view schematically showing a cross section of BB 'of a filtration apparatus including a non-powered agitation coagulation apparatus according to an embodiment of the present invention.
10 is a schematic view illustrating a multi-stage filtration process including a non-powered agitation coagulation apparatus according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, which are intended to illustrate the present invention in a manner that allows a person skilled in the art to easily carry out the invention. And does not mean that the technical idea and scope of the invention are limited.

In the description of the embodiment of the present invention, the raw water may be referred to as filtered water, treated water, discharged water, or the like depending on the movement path or state, and the backwash water may also be referred to as washing water or drain water or the like.

A multi-stage filtration apparatus according to an embodiment of the present invention comprises: a container composed of two or more stages; A filter medium to be introduced into each of the stages for filtration; A filtration layer formed by collecting the filter media; And a raw water inlet pipe through which raw water is introduced into the uppermost end of the vessel, and a filtered water discharge pipe through which the treated water is discharged to the lowermost end of the vessel.

1 is a cross-sectional view of a multi-stage filtration apparatus according to an embodiment of the present invention. Fig. 2 is a cross-sectional view of the fiber ball filter material, and Fig. 3 is a plan view of a bottom surface of the lower end. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

The container 10 of the multi-stage filtration apparatus of the present invention is preferably formed as a cylindrical body. The container 10 is formed in a multi-layered structure, and each end can be formed with the same diameter and communicate with each other.

A raw milk inflow inlet 20 through which raw water can flow is connected to one side of the top of the top of the vessel. A raw water inflow control valve is provided in a part of the raw milk inflow pipe 20 to control the inflow amount of the raw water.

A backwash inlet pipe 30 through which backwash water or backwashing air can flow is connected to one side of the upper end of each end except for the uppermost end. A portion of the backwash inlet pipe 30 is provided with a backwash water or backwash air inflow control valve to regulate the inflow amount of air. In the case of the uppermost stage, the backwash water is discharged through the raw milk inlet 20 and discharged through a separate pipe from the raw milk inlet 20.

A filtrate discharge pipe 40 through which filtrate water can flow is connected to a lower side of the lower end of the vessel. A portion of the filtered water discharge pipe 40 is provided with a filtrate flow control valve to control the flow rate of the filtered water. In addition, backwash water or backwashing air may be introduced into the filtered water discharge pipe 40. The filtered water discharge pipe (40) is provided with a backwash water or backwashing air inflow control valve to control the inflow amount of air.

A plurality of filter media are provided at each end to form a filtration layer. A fiber ball filter material 50 may be used for the filtration layer. The fiber filter material filter is a spherical porous filter made of cotton or the like, and functions to filter suspended materials at each end. As shown in FIG. 2, the fiber ball filter material 50 may include a core portion 51 formed to be hard and a tabular portion 52 connected to the core portion to form a thick fibrous layer. The fiber ball filter material 50 may be formed to have a diameter in the range of approximately 10 to 50 mm.

The lower surface 60 of each filtration stage is formed in a U-shape as a whole, and a plurality of strainer nozzles 70 are installed. The strainer nozzle 70 allows the filtered water having passed through the upper end to be uniformly dispersed in the lower end thereof, while spraying air or washing water upward to back up the fiber ball filter media 50 during backwashing. Preferably, the lower surface 60 of each end can be divided into a central portion 61 and an outer portion 62. The central portion 61 is formed as a flat plate and is provided with a strainer nozzle 70, and the outer frame portion 62 is formed to be inclined outwardly in a 'V' shape. Accordingly, when air or water is blown from the strainer nozzle 70, a circulation flow is formed upward in the central portion 61 and downward in the outer portion 62, so that the fiber ball filter media 50 is uniformly cleaned while being smoothly mixed, The position of the fiber ball material 50 is arbitrarily changed (see FIG. 5). That is, since the surface layer of the filtration layer is arbitrarily positioned with the plurality of fiber ball filter media 50 mixed, it is possible to maintain filtration performance for a long period of time without the need for frequent replacement as in the cartridge filter.

A plurality of slots 63 are formed in the outer frame 62. A slot 63 is formed to assist circulation of the circulation flow, and a part of the filtration water can flow downward through the slot 63 at the time of filtration. A screw groove 64 for screw connection may be formed in the outermost portion of the lower surface 13.

The operation of the multi-stage filtration apparatus according to one embodiment of the present invention will be described. The operation of the multi-stage filtration apparatus according to an embodiment of the present invention is roughly classified into three types. The first is the action of filtering raw water to produce treated water, the second is the backwashing action for the filter media, and the third is the squeezing action to remove residual water in the filter media after backwashing.

First, referring to FIG. 4, a description will be made of a process of filtering raw water into treated water.

The raw water inflow control valve is opened so that raw water flows into the uppermost end 11 of the vessel through the raw milk inflow inlet 20. The raw water is pressurized through a pump (not shown) formed outside the raw milk inflow pipe 20 and flows into the upper end 11 of the container. The raw water is filtered through a filtration layer 12 formed of a fiber ball filter material 50. The filtered treated water passes through a strainer nozzle 70 provided on each bottom surface and flows into a lower end of the strainer nozzle 70, And is evenly distributed to the surface layer of the filtration layer 12 made. The treated water having passed through each filtration layer in turn is discharged through the filtered water discharge pipe 40. At this time, the filter material upper space 13 is present at each end of the container and the height of the filter material upper space 13 is preferably equal to or greater than the height of the filtration layer 12, more preferably, Space ratio of 1: 1 to 2 is preferable.

The results of the comparison of the performance changes by the depth of the filter media are as follows.

Filter media depth (mm)
(Filter media / upper space ratio) Turbity (NTU) TSS (mg / L) enemy Treated water enemy Treated water 0 (0) 2.46 0.53 5.2 3.2 500 (1: 3) 1.96 0.29 6.0 1.6 1,000 (1: 1) 2.04 0.20 5.6 0.8 1,500 (3: 1) 2.01 0.25 6.0 4.3

Next, the backwashing operation of the filter media 50 will be described with reference to FIG.

The raw water inflow control valve is closed and the filtered water inflow / outflow control valve is opened. The treated water flowing through the filtered water discharge pipe (40) or the backwashing inlet pipe (30) is sprayed from the strainer nozzle (70) to clean the filter media. At this time, a circulation flow downward from the central portion 61 to the outer frame portion 62 is formed at the lower end by the water stream injected from the central portion 61 of the lower end bottom face. The filter material is mixed with each other by this circulation flow and the washing is evenly performed. The washing water, which has been washed in the lower end to the upper end in turn in the direction of the upper end in turn, is washed by the uppermost raw milk (50) And then discharged through the inlet 20.

Further, pressurized air is introduced into the upper end 11 through the filtered water discharge pipe 40 or the backwash inlet pipe 30, and this air is injected upward through the strainer nozzle 70. The air injected upward circulates the filter material stacked on the upper end to help the cleaning to occur more efficiently. As a result, the cleaning of the filter material is effectively performed to improve the filtration performance, and the effect of increasing the service life and longevity is brought about.

Next, referring to FIG. 6, the compression action after backwashing on the filter material will be described.

After removing the suspended matters and impurities in the filter media through backwashing, the filtrate flow control valve is opened. The remaining water in the container flows from the uppermost end to the lower end of the strainer nozzle 70 at the lower end of each end, passes through the last end, and is discharged through the filtered water discharge pipe 40. At this time, the filter material is squeezed to minimize the water content in the filter material and the container.

Hereinafter, a multistage filtration apparatus including a non-powered mixed flocculation tank according to an embodiment of the present invention will be described in detail.

FIG. 7 is a schematic view illustrating a filtration apparatus including a non-powered agitation coagulation tank according to an embodiment of the present invention. More specifically, FIG. 7 is a schematic view illustrating a filtration apparatus for agglomerating fine particles by injecting a coagulant into raw water to form a floc, A media filter comprising a flocculation tank (100) and a container (10) for filtering and removing flocs contained in raw water by using a filter material (50) filled in the mixing tank (100) A first mixed flocculation unit 111 for filling a first turbulent flow-inducing body 111 in the inner space and generating high-speed turbulence for forming a flock primarily in the raw water to replace the function of the conventional mechanical mixing flocculation tank 100 110 and the second turbulent flow-forming derivative 121 are filled in the inner space and compared with the first mixed flocculation portion 110 for secondarily growing the flocks on the raw water that has passed through the first mixed flocculation portion 110 Produces low velocity, slow turbulence The second mixed cohesion unit 120 is provided to circulate the fine particles contained in the raw water in a nonmoving state by a turbulent flow without any additional stirring power so as to be brought into contact with the coagulant and flocculate to a certain size. The mixed flocculation tank 100 is preferably provided in a supply channel 300 where raw water is transferred to the vessel 10.

The filtration apparatus including the non-powered agitation coagulation tank of the present invention can receive raw water from the outside through the supply channel 300. The supply channel 300 includes an inlet channel 310 through which raw water, And a dispensing channel (320) for feeding the introduced raw water to the container (10), respectively.

The first mixed cohesion unit 110 may be provided in the inlet channel 310 and the second mixed cohesion unit 120 may be provided in the distribution channel 320. The first mixed cohesion unit 110, The partition wall separating the inlet channel 310 and the distribution channel 320 is provided to maintain the different turbulence intensities between the first and second mixed flocculating portions 120. The raw water passing through the inlet channel 310 flows through the partition wall And is preferably supplied to the distribution channel 320 by a drop.

8 and 9, the inlet channel 310 is provided with a first partition 311 disposed at a position spaced from the bottom of the inlet channel 310 by a predetermined distance so as to divide the internal space, The first turbulent flow inducing elements 111a and 111b are filled in the respective inner spaces of the inlet channels 310 partitioned through the first partition 311 so that the introduced raw water flows through the first turbulent flow inducing elements 111a Through the first turbulent flow-inducing body 111b and then to the distribution channel 320. In this case,

The first mixed coagulation unit 100 is a watertight space in which fine particles contained in the raw water are circulated by the generated turbulence to form a floc by mutual coupling with the coagulant, The first turbulent flow forming unit 111 may be provided in the flow direction and the inflow pipe into which the raw water flows may be included in a region above the first mixed flocculating unit 110.

The raw water flowing in the form of a straight water stream through the inflow pipe passes through the first turbulent flow forming body 111 filled in the first mixed cohesive portion 110 to form a rapid turbulent flow, The flocs are formed while the fine particles and the flocculant contained in the slurry contact each other. The first turbulent flow-inducing element 111 may be a multilayer structure of a plurality of mesh-type materials or a plurality of bundles of fibers intertwined with each other. Preferably, the first turbulent- The holes may be stacked asymmetrically so that the holes do not coincide vertically. Since the holes between the materials of the mesh type are stacked asymmetrically in the vertical direction, it is possible to generate turbulence while the raw water passes through the mesh type material by gravity and control the turbulence speed generated according to the size of the holes .

When the treated water having passed through the first mixed flocculation unit 110 is transferred to the distribution channel 320 due to a drop, the water passes through the second mixed flocculation unit 120 formed in the distribution channel 320, Passes through the bypass channel 322 partitioned in parallel to the downstream side of the flocculating portion 120, and is transported to the vessel 10.

The distribution channel 320 includes a main flow path 321 having the second mixed flocculation unit 120 in the distribution channel 320 and a bypass flow path 322 provided in parallel to the main flow path 321. A second partition 323 partitioning the main passage 321 and the bypass passage 322; And at least one water gate 324 provided on the second partition 323 in order to transfer the treated water flowing into the main channel 321 to the bypass channel 322, The second mixed flocculation portion 120 is provided with the state of the raw water through the water gate 324 of the second partition wall 323 for partitioning the second mixed flocculation portion 120 and the bypass flow path 322 into the second mixed flocculation portion 120 Can control the flow of the charged poled type material through the filled stage.

The second agglomerated agglomerate 120 is formed by growing the flocculant contained in the treated water due to the slow turbulent flow generated when the treated water having passed through the first agglomerated agglomerator 110 passes through the second turbulent flow former 121 As a space, the downstream side region can communicate with the container 10 capable of filtering the treated water containing the flocs.

The speed of the rapid turbulence of the first mixed coagulation unit 110 and the slow turbulent flow of the second coagulated coagulation unit 120 are not particularly limited and the first mixed coagulation unit 110 and the second coagulated coagulation unit 120 Quot;) < / RTI >

The second turbulent flow inducing material 121 is filled with a plurality of materials of a pall ring type. Preferably, the plurality of pollen-type materials are filled in a plurality of stages .

The second agglomerated agglomerating unit 120 having the plurality of stages filled with the plurality of poling type materials may be used to control the number of the plurality of stages according to the state of the raw water, It is preferable that the packing density is made smaller as the fuel is separated toward the downstream region. This is because the lower the filling density, the lower the turbulence rate and the flocs can grow larger.

The filtration apparatus including the non-powered agitation coagulation bath of the present invention can control the number of the plurality of stages of the second agglomerated agglomerate 120 according to the state of the raw water requiring water treatment or control the flow through the bypass flow path 322 can do.

More specifically, when the size of the flocculated flakes contained in the treated water passing through the first mixed flocculation unit 110 grows to a sufficient size in the vessel 10, the plurality of stages of the second flocculated flocculating unit 120 A first flow toward the vessel 10 through the bypass passage 322 and a first flow through the first mixing cohesion section 110 and a plurality of ends of the second mixing cohesion section 120 are performed only through the second partition 323 The second flow directed toward the vessel 10 and the first mixed flocculation 110 and the second flocculated flocculent 120 are transferred to the bypass flow path 322 through the water gate 324 included in the vessel 10 The third flow directed to the second flow can be controlled.

Hereinafter, the operation of the mixing and agglomerating apparatus for filtering materials according to one embodiment of the present invention will be described.

FIG. 10 is a view illustrating a multi-stage filtration process including a non-powered agitation coagulation bath 100 according to an embodiment of the present invention. More specifically, the flocculation agent and raw water in the raw water are agglomerated to form a floc In the mixed coagulation tank for growth, a first turbulent flow inducing body 111 is filled in the inner space so as to replace the function of the conventional mechanical coagulation flocculation tank, and a high turbulent flow inducing agent 1 mixed flocculating portion 110 and the second turbulent flow forming portion 121 are filled in the inner space so that the flocculated flocculating portion has a lower rate than the first flocculated flocculating portion for secondarily floc growing on the raw water passing through the first flocculating flocculating portion, And the second mixed coagulation unit 120 for generating a slow turbulent flow in the raw water is provided so that the fine particles contained in the raw water can be circulated internally by turbulent flow without any additional stirring power There is shown a nonmoving agglomerated coagulating bath which is brought into contact with the flocculating agent and coagulated to a predetermined size.

The raw water that has passed through the non-powered mixed flocculation tank 100 is introduced into a multi-stage filtration apparatus 10 which is filled with filter media and forms a filtration layer, passes through each stage, and is discharged through a filtration water discharge pipe 40.

It is needless to say that, in all the above embodiments, the adjustment of each valve and the movement of the length adjusting means can be implemented by separately configuring the control unit so as to be controlled by the electric and electronic method.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the invention, It is obvious that the claims fall within the scope of the claims.

10: container 11: upper end
12: filtration layer 13: filter media upper space
20: raw milk inlet 30: backwash inlet pipe
40: Filtration water discharge pipe 50: Fiber ball filter media
51: deep portion 52:
60: Filtration stage bottom 61: Filter stage bottom center
62: Filter bottom surface outer part 63: Slot
64: screw groove 70: strainer nozzle
100: Adhering cohesive device 110: First cohesive cohesive part
111: first turbulent flow forming derivative 120: second mixed flocculating portion
121: second turbulent forming derivative 300: supply channel
310: Inlet channel 311: First partition
320: distribution channel 321: main flow path
322: bypass channel 323: second partition
324: The water gate

Claims

A non-motorized agglomerated flocculating tank for flocculating the fine particles by adding flocculant to raw water to form and grow flocs;
A container made of two or more stages and having a raw milk inlet and a filtered water outlet; And
And a filter material on each end of the container to form a filtration layer,
In the mixed coagulation bath,
A first agglomerated agglomerated portion having a first turbulent flow-forming derivative filled in the internal space to generate turbulence for forming flocs on the original raw water; And
A second agglomerated agglomerator for generating a turbulent flow at a lower rate than the first agglomerated agglomerator for secondarily floc agglomerating on the raw water passing through the first agglomerated agglomerator, Lt; / RTI >
The mixed flocculation tank is provided in a supply channel through which raw water is transferred to the vessel,
Wherein the supply channel comprises:
And a plurality of separate distribution channels for supplying the inlet channel into which the raw water, which is the object to be treated, flows from the outside, and the raw water that has been introduced, to the container.

The multi-stage filtration apparatus according to claim 1, further comprising a backwash inlet pipe through which the backwash water or the backwash air is introduced into each end of the vessel except the uppermost end thereof.

The multi-stage filtration apparatus according to claim 1, wherein a flange for introducing and discharging a filter medium is installed at each end of the vessel.

The multistage filtration apparatus according to claim 1, wherein a filter upper space is provided at each end of the container and a height of the filter upper space is equal to or greater than a height of the filter layer.

The multi-stage filtration apparatus according to claim 1, wherein a plurality of strainer nozzles are coupled to the lower surface of each stage, and a circulation flow is supplied to the filter media during backwashing to mix the filter media.

delete

A multistage filtration method comprising a non-powered agitation coagulation tank, a container having two or more stages and having a raw milk feed inlet and a filtrate outlet pipe, and a filter material forming a filtration layer at each end of the container,
A pretreatment step of adding flocculant to the raw water and supplying it to the admixture flocculating tank, and then coagulating the fine particles to form and grow flocs;
An inflow step of introducing raw water having passed through the mixed flocculation tank into the container;
A filtration step of dropping the introduced raw water through the filtration layers of the respective stages from the uppermost stage to the lower stage to the lower stage; And
And a treated water discharging step of discharging the treated water having passed through the filtration layer at the last stage through a filtered water discharge pipe connected to the last stage,
In the mixed coagulation bath,
A first agglomerated agglomerated portion having a first turbulent flow-forming derivative filled in the internal space to generate turbulence for forming flocs on the original raw water; And
A second agglomerated agglomerator for generating a turbulent flow at a lower rate than the first agglomerated agglomerator for secondarily floc agglomerating on the raw water passing through the first agglomerated agglomerator, Lt; / RTI >
The mixed flocculation tank is provided in a supply channel through which raw water is transferred to the vessel,
Wherein the supply channel comprises:
And a plurality of separate distribution channels for supplying an inlet channel into which the raw water, which is an object to be treated, from the outside, and the raw water, which have been introduced, are supplied to the container, respectively.

The multi-stage filtration method according to claim 7, wherein a flange is provided at each end of the container, and the filtering material is introduced through the flange to perform filtration.

The multi-stage filtration method according to claim 7, wherein filtration is performed in a state where a filter upper space exists at each end of the container and a height of the filter material upper space is equal to or greater than a height of the filter layer.

delete

A backwashing method using the multi-stage filtration apparatus according to any one of claims 1 to 5,
Applying backwash water to the vessel;
A backwashing step of removing foreign matter in the filter media while passing the input backwash water through the filtration layers at the respective stages from the inlet end to the upstream end; And
And discharging the backwash water containing the foreign matter through a raw water inlet connected to the uppermost stage.

12. The method of claim 11,
And a filter material pressing step of removing water in the filter material by passing the backwash water through the filtration water discharge pipe connected to the final stage after passing the backwash water through the top end from the bottom end direction after the backwashing water discharge step, Way.