KR102049944B1 - Perforated drain pipe for back-washing wastewater, and dissolved air flotation type water treatment apparatus - Google Patents

Abstract

An object of the present invention is to improve the backwashing efficiency by facilitating the discharge of the backwashing water and minimizing the loss of the filter medium in the water treatment apparatus utilizing the filter medium requiring the backwashing process, while at the same time without the additional power The present invention relates to a porous drain pipe that can easily transport backwash water through a method and a dissolved air flotation type water treatment device including the same. The porous drain pipe including a slit-shaped porous area prevents the loss of the filter medium while simultaneously Ease of discharge can be facilitated, and backwashing at a sufficient speed has the effect of performing efficient backwashing.

Description

Drain pipe for easy backwashing and dissolved air flotation type water treatment device including same {PERFORATED DRAIN PIPE FOR BACK-WASHING WASTEWATER, AND DISSOLVED AIR FLOTATION TYPE WATER TREATMENT APPARATUS}

The present invention relates to a drainage pipe that can easily drain the backwash water and a dissolved air flotation type water treatment device including the same, and more specifically, backwashing which is essentially performed in a filtration process using a media. The porous structure of the porous drain pipe is formed in the form of a slot to minimize the loss of the filter medium while effectively collecting and discharging the backwash water generated by back-washing, and can be applied to various filter media. The present invention relates to a dissolved air flotation type water treatment device having an advantage of minimizing washing water clogging or loss of filter medium, and a drain pipe included therein.

In the filtration process using a media, backwashing through air or water is essential, and a technique for collecting and transporting backwashing wastewater generated in the backwashing process is required.

Conventional Republic of Korea Patent Publication No. 1156125 (2012.06.20., 'Dissolved air floating pre-treatment device'), etc. generated by forming a concrete trough (tray) or tray on the top of the area filled with the lower filter medium of the water tank The backwash wastewater was collected and directed to the backwash gate formed on the outer wall of the tank.

However, these troughs or trays cannot completely prevent the loss of filter media, and the economic burden on the cost of replenishing the filter media and the deterioration of the filtration function due to the loss of the filter media can lead to the leakage of contaminants (turbidity) contained in the backwash wastewater. There is a possibility.

On the other hand, the Republic of Korea Patent Publication No. 1271089 (2013.06.12. Announcement, 'porous plate device of the automatic backwash filter'), etc. separately provided with a hood with a drive motor without forming a trough or tray at the bottom of the tank Therefore, a method of removing suction by a separate device installed at the outside of the tank has also been suggested.

However, when a separate backwash wastewater suction device is provided and collects and transports the backwash wastewater, additional installation costs and power supply costs are required, and thus there is a problem that the capex or the OPEX of the entire facility increases.

Patent Registration No. 10-1156125 Patent Registration No. 10-1271089

The present invention is to solve the above-mentioned problems, an object of the present invention in the water treatment apparatus using a filter medium that requires a backwashing process, while backwashing by facilitating the discharge of the backwashing water and at the same time minimize the loss of the filter medium backwashing While improving the efficiency, it is to provide a porous drainage pipe and a dissolved air flotation type water treatment device including the same that can be easily transported backwash water through a natural flow method without a separate power.

The porous drainage pipe 20 according to an embodiment of the present invention for achieving the above object is provided with a filtration unit 10 is filled with a plurality of filter media (11) inside the raw water of A drain pipe located inside the filtration tank 1 capable of filtering contaminants, which is located above the filtration unit 10 in the filtration tank 1, and has a plurality of slit-shaped intake ports 21 formed on the surface thereof. It is connected to pass through one side of the inner wall of the filtration tank 1, characterized in that for collecting and draining the back washing water generated during the back-washing process of the filter medium (11).

The porous drain pipe 20 may be made of glass fiber reinforced plastic (GRP), and the inlet 21 of the slit type is based on the center of the longitudinal cross section of the circumferential drain pipe having a circular cross section. As a result, it is preferable that the slits are formed only on the outer circumferential surface of -60 ° to 60 ° on both sides.

Based on the center of the longitudinal cross section of the circumferential drain pipe having a circular cross section, a support region 24 in which no slit-shaped water inlet 21 is present is formed at the top or bottom thereof, thereby providing structural stability and durability of the porous drain pipe. Can be given.

As the filter medium used in the present invention, it is preferable that a ball filter filter medium 11 is used. For example, a metal such as an aluminum alloy or a synthetic polymer material such as PP, PE, PVDF, or the like may be used. Preferably, it is also possible to use a core-shell structured ball filter in which the metal core member and the polymer plastic shell member are combined. More preferably, a core-shell ball filter in which the core is a metal alloy and the shell is polypropylene (PP), polyethylene (PE) or polyvinylidene fluoride (PVDF) is used. Can be used.

The ratio D / l of the diameter D of the filter medium 11 and the width l of the slit formed in the intake port 21 according to the present invention is about 3 to 5, and the slit formed in the intake port 21. The distance (w) between them is preferably about 20 ~ 30mm, in the case of a porous drain pipe including a slit form of the above range, it is possible to minimize the loss of the filter medium while minimizing the deposition of the filter medium (11).

For example, when the diameter of the ball media which is a filter agent is 40 mm, it is preferable that the width | variety of the intake port of a slit form is small in the range of 8-13.3 mm.

The drain pipe 20 is preferably fixed to the upper surface of the concrete slab 22 is provided on the upper portion of the filtration unit 10, the transfer pipe 20a is connected to penetrate through the inner wall of the filtration tank 1, At least one intake pipe 20b communicating with the transfer pipe 20a and provided in a normal direction of the transfer pipe 20a may further include a region 1a connected to penetrate one inner wall of the filtration tank 1. The area 1a side is preferably set lower than the opposite side so that the backwash wastewater collected in the) direction naturally flows.

Another embodiment of the present invention includes a dissolved air floatation (DAF) water treatment apparatus (A) including a floatation tank (1) for removing contaminants contained in raw water. A filtration unit (10) provided at a lower portion of the tank (1) and filled with a plurality of filter media (11) for filtering the contaminants remaining in the treated water from which the pollutants are first removed from the raw water; And a porous drain pipe 20 provided in the flotation tank 1 and installed on the filtration unit 10 to collect and drain backwash water generated during a back-washing process of the filter medium 11. It includes, the surface of the porous drain pipe 20 is formed with a plurality of slit-shaped intake port 21, the porous drain pipe 20 is connected to be collected so as to penetrate through one side of the inner wall of the floating tank (1) The wash water is characterized in that it is guided to the waste water collection tank (30).

In this case, the porous drain pipe 20 and the slit structure used are the same as the porous drain pipe 20 described above, and the filter material 11 is formed of a porous plate to prevent the filter material 11 from being separated out through the upper part of the filter part 10. It may further include a filter medium loss prevention portion 12 is provided.

As described above, the porous drain pipe for drainage of the backwashing water of the present invention and the dissolved air flotation type water treatment device including the same can facilitate the discharge of the backwashing wastewater while preventing the loss of the filter medium. It is possible to perform efficient backwashing, and there is an effect that the backwashing wastewater collected without a separate power can be transferred to the rear collecting tank through the natural flow method.

In the case of the dissolved air flotation type water treatment device including the porous drain pipe according to the present invention, the backwashing efficiency of the filter medium is high, so that the water quality (eg turbidity, solid content, etc.) of the final treated water may be lowered to a certain level or lower even after long use. There is an advantage that can be maintained.

1 is a plan view showing a state in which the porous drain pipe 20 of the present invention is installed.
FIG. 2 is a cross-sectional view taken along line AA ′ of FIG. 1.
3 is a side view showing a state of the filtration tank 1 in which the porous drain pipe 20 of the present invention is installed.
4 is a process schematic diagram of the dissolved air flotation type water treatment device A having the porous drain pipe 20 of the present invention disposed below the floating tank 1.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms or words used in the present specification and claims should not be construed as being limited to ordinary or dictionary meanings, but should be construed as meanings and concepts consistent with the technical spirit of the present invention.

Throughout this specification, when a member is located "on" another member, this includes not only when one member is in contact with another member but also when another member exists between the two members.

Throughout this specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless otherwise stated.

Terms such as "first" and "second" are intended to distinguish one component from another component, and the scope of rights should not be limited by these terms. For example, the first component may be named the second component, and similarly, the second component may also be named the first component.

Suspended Solids (Suspended Solids) is a term that generally refers to a small particle content of 0.1 μm or more contained in water, and when it is contained in water, it causes severe turbidity and increases BOD and COD. Sewage that contains a lot of suspended solids is a contaminant that must be removed because it can accumulate in the pipeline, obstruct the flow of water, and decompose organic matter and deteriorate the water quality.

On the other hand, the suspended solids are classified as a particle size is slightly larger than the colloidal components and, in contrast to the dissolved substances, are suspended in water. The suspended solids are precipitated to some extent after a certain period of time, but the particle size tends to be very slow. Thus, flocculants are formed by agglomerating particles to remove suspended solids in water. It is common to remove the traces of suspended solids by means of sedimentation or flotation, or by using filter media.

Generally, the suspended solids are filtered while the suspended solids are filtered out of the filter medium, but after a certain time, suspended solids accumulate between the filter mediums, resulting in a blockage of the filter medium, resulting in a decrease in the flow rate and overall decrease in the filtration efficiency. In this case, it is necessary to remove the suspended matter caught between the filter media by backwashing in the opposite direction of the filtration direction. However, frequent backwashing results in loss of filter media, and in the case of using general media such as sand, some of the filter media is crushed by the backwashing process. In severe cases, the filter tank is closed or the frequency of replacement of the filter media is frequently increased. It has the disadvantage of causing deterioration of water quality and increase of maintenance costs. 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 water is generated and a large processing cost is required to reprocess it.

The filtering device is a device that supplies contaminated raw water through a filter medium to make clean treated water, and is widely used not only for drinking water but also for treatment of water and sewage or factory water. In particular, the filtration apparatus used for the treatment of river water or plant wastewater or desalination facilities of seawater is gradually becoming larger in order to increase the amount of treated water and improve water quality.

On the other hand, in the past, sand or anthracite coal was used as the filter medium, but problems such as the trapping space of suspended solids in the vicinity of the surface layer, the easy clogging, the difficulty in cleaning, etc. Dual media filters have been developed.

However, even in the case of the multi-layer filter, the media filters are substantially dense and aggregated in a filtration process, and in the back washing process, the media filters are formed in the drain pipe in the form of a plurality of pores. There is still a problem that it is difficult to achieve an effective filtration effect by blocking the intake part to reduce the backwashing efficiency and to be lost through the pores during the backwashing process.

First, according to a preferred embodiment of the present invention, in the filtration tank 1 for filtering contaminants of raw water, the filtration unit 10 filled with a plurality of filter media 11 is provided therein. It provides a drain pipe 20 for collecting and draining backwash wastewater generated by back-washing. A plan view of a drain pipe 20 according to an embodiment of the present invention is shown in FIG. 1, and the AA ′ cross-sectional view of FIG. 1 is shown in FIG. 2.

The present invention can be applied to an apparatus in which water treatment is performed through a filtration unit 10 in which a plurality of filter media 11 is filled, and preferably, a dissolved air floating type (hereinafter referred to as 'DAF') described below. It can be applied to a DABF (Dissolved Air Flotation with Ball Filter) system having a filtration unit 10 filled with a ball filter filter material 11 below the floating tank 1 of the water treatment apparatus A.

The drain pipe 20 includes a filtration tank 1 (or a floating tank 1 of the DAF water treatment apparatus A, a filtration tank 1 for performing a filtration process using a filter medium hereinafter, and a floating tank 1 of the DAF water treatment apparatus A). ) Is provided in the upper part of the filter unit 10, which is a region in which the filter medium 11 is filled, and is formed through pressurized water or air bubbles applied upward from the bottom for back washing. It serves to collect and transport the backwash waste water to be filtered from the upper portion (10).

The drain pipe 20 of the present invention is preferably a perforated drain pipe (Perforated Drain Pipe) in which a plurality of slit-shaped intake ports 21 are formed on a surface thereof. The backwash wastewater is collected and collected through the intake port 21 formed on the surface, but the filter medium 11 suspended in the upper portion due to the backwashing should not be drawn in, thereby preventing the loss of the filter medium 11. As a result, the backwashing intensity can be adjusted within a wide range, enabling high efficiency backwashing.

Slit (slit) of the intake port 21 is preferably formed in the outer peripheral portion of -60 ° to +60 ° only on both left and right sides with respect to the center of the longitudinal cross section of the circumferential drainage pipe having a circular cross section, the circular cross section It is preferable that there is a support region in which the slit-shaped water intake port 21 does not exist on the uppermost or lowermost side with respect to the center of the longitudinal cross section of the circumferential drainage pipe having a.

Since the slit is not formed in the area of -60 ° to -90 ° and the outer circumference area of + 60 ° to + 90 ° based on the center of the longitudinal circular cross section of the drain pipe, a certain amount of washing water can be drawn in. The structural form can be physically maintained.

The width (l) of the slit can be changed according to the diameter of the filter medium, the ratio (D / l) to the diameter (D) of the filter medium is preferably in the range of about 3 to 5.

The width of the slit formed in the drain pipe should be appropriately selected according to the diameter of the filter medium. In the process of discharging the wash water, the ball media, which is a polymer filter material, may be contracted by the wash water to block the slit or escape through the slit. Because.

As shown in FIG. 1, the drain pipe 20 of the present invention is connected to penetrate the region 1a of one side of the inner wall of the filtration tank 1 so that the backwash wastewater collected through the intake port 21 is disposed outside the filtration tank 1. It can be guided to the collection tank (30). In addition, the material of the drain pipe 20 of the present invention is easy to form the intake port 21 on the surface of the drain pipe 20, to be composed of glass fiber reinforced plastic (GRP) for easy installation and maintenance Can be.

Looking at the slit-shaped intake port 21 formed on the surface of the drain pipe 20 with reference to Figure 2, based on the center of the longitudinal cross-section of the circumferential drain pipe having a circular cross section -60 ° to +60 only on both sides The outer periphery of ° is formed in the form of a slit, that is, the support area 24 is not formed in the slit on both sides of the lower side -60 ~ -90 ° region of the pipe and both sides +60 ~ +90 °.

Such slits are preferably formed in the drainage pipe 20 at intervals of about 20 to 30 mm. If the slits are formed too densely, the flow rate of the washing water becomes too large, and if the slits are disposed too tightly, the effect of sufficient drainage pipes may be achieved. You won't get it.

As a result, when the backwash wastewater is filled in the region in which the drain pipe 20 is formed at a predetermined level or more through the backwashing process, the backwash wastewater is collected through the intake port 21 and at the same time, the backwash wastewater is below a predetermined level. When the collection is completed, the collected backwash wastewater may be transported to the wastewater collection tank 30 without again flowing out.

In addition, the waste pipe 20 of the present invention has the region 1a side more than the opposite side so that the waste water collected in the direction of the region 1a connected so that the drain pipe 20 penetrates the inner wall side of the filtration tank 1 naturally flows. It is desirable to ensure low installation. 3 to 4, it can be seen that the drain pipe 20 is installed to have a predetermined slope. As a result, the backwash wastewater collected without additional power can be naturally discharged to the wastewater collection tank 30 at the rear end, so that the OPEX of the water treatment process is reduced and economical.

Drain pipe 20 of the present invention is preferably fixed to the upper surface of the concrete slab 22 is provided in the upper portion of the filter unit as shown in Figs. At this time, the concrete slab 22 is not provided in the upper front of the filter unit 10, is provided to be limited to the area necessary for fixing the drainage pipe 20, as shown in Figure 1, through the remaining empty space The washing waste water is filled to the top.

The drain pipe 20 is fixedly installed on the upper surface of the concrete slab 22, and fixed to the anchor 23 on the concrete slab 22 with respect to the joint portion formed in the process of assembling and installing the drain pipe 20 of the GRP type. It is preferable to make it.

On the other hand, the drain pipe 20 of the present invention is at least one intake pipe (20a) connected to pass through one side of the inner wall of the filtration tank 1, and connected to communicate therewith provided in the normal direction of the transfer pipe (20a) ( Preferably 20b). As shown in Figure 1 may be configured in a '+' form. Intake pipes 21 are preferably formed in both the transport pipe 20a and the water intake pipe 20b, and the backwash wastewater collected through the water intake pipe 20b gathers in the center and collectively goes to the wastewater collection tank 30. Since it should be drained, it is preferable that the diameter of the central feed pipe 20a is larger than the diameter of the intake pipe 20b.

Next, the present invention is a DAF water treatment device (A) comprising a flotation tank (1) to remove contaminants such as suspended matter, turbidity or algae foreign matter contained in the raw water according to another preferred embodiment, A filtration unit 10 provided below the floating tank 1 and filled with a plurality of filter media 11 for filtering contaminants remaining in the treated water from which the pollutants are first removed from raw water, and the floating tank 1 ) Is provided in the filter unit 10 is provided on the filter unit 10 to provide a DAF water treatment device (A) comprising a drain pipe 20 for collecting and draining backwash wastewater generated during the backwashing process of the filter medium (11). The schematic diagram of the DAF water treatment apparatus A of this invention is shown in FIG.

By introducing the filtration unit 10 filled with the ball filter filter material 11 in the general DAF facility to the lower portion of the floating tank 1, it is possible to reduce the installation space and facilitate maintenance, to reduce the capex and opex, seawater, It is possible to more effectively and thoroughly remove contaminants such as suspended substances, turbidity, and algae contained in raw water, such as sewage or wastewater, and there is an advantage in that backwashing can be conveniently performed.

In addition, by effectively collecting and discharging the backwash wastewater generated while performing the backwash through the drain pipe 20 provided above the filtration unit 10, the filtration efficiency can be maximized.

The ball filter filter material 11 used in the Dissolved Air Flotation with Ball Filter (DABF) system is, for example, a core member made of a metal alloy and coated on the outside of the core member with a plastic material coated on the outside thereof. It may be made of a fiber yarn such as polypropylene (PP), polyethylene (PE) or polyvinylidene fluoride (PVDF), more preferably the core is aluminum alloy, the shell is polypropylene (PP), polyethylene (PE) Or a spherical ball filter in the form of a core-shell, which is polyvinylidene fluoride (PVDF), and preferably has a diameter of about 20 to 45 mm.

The treated water that has passed through the pretreatment chambers of the flocculation tank, the settling tank, and the mixing tank (2, 3) comes into contact with the microbubbles supplied from the contact basin of the flotation tank 1, causing contaminants to float and primarily contaminated. The treated water from which the material is removed passes through the filtration unit 10 under the floating tank 1 filled with the filter material 11, and further removes contaminants and moves to the treated water dressing tank 4 at the rear end.

A lower support 13, such as a hole block portion or a strainer portion, is provided at the lower portion of the filter portion 10 so as to support the filter medium 11 while preventing the ball filter filter material 11 from escaping to the outside through the lower portion. An upper portion of the filter unit 10 may be provided with an additional filter medium loss prevention unit 12 such as a porous panel in order to prevent the filter medium 11 from being separated and lost due to backwashing. When the filter medium loss prevention unit 12 is separately provided between the filter unit 10 and the drain pipe 20, the loss of the filter medium 11 may be prevented to some extent, so that the water intake port 21 may be further increased. The size of can be made even larger.

On the other hand, when the concentration of pollutants in the raw water is within an acceptable range by the DAF system alone, or when the use of the drain pipe 20 is unnecessary for a certain period of time, such as when backwashing of the filter medium 11 is not necessary for a while. By blocking the intake port 21 formed on the surface of the drain pipe 20, water may be prevented from flowing into the drain pipe 20.

Hereinafter, an embodiment of a porous drain pipe for drainage of backwash wastewater and a dissolved air flotation type water treatment device including the same will be described. However, this is only one of the most preferred embodiment of the present invention and does not represent all of the technical idea of the present invention, it is understood that there may be various equivalents and modifications that can replace them at the time of filing the present invention. shall.

Example 1

An embodiment of the backwashing process performed in the flotation tank 1 provided with the drain pipe 20 of the present invention will be described.

First, close the inflow gate and the circulating water injection valve of the floating tank 1 in the DAF water treatment device A to be backwashed, and drain the water in the floating tank 1. At this time, the drainage level in the floating tank 1 is up to the upper part of the filtration unit 10 (the lower portion of the drain pipe 20 of the present invention) and drains in conjunction with the water level gauge installed in the floating tank 1.

When the drainage in the flotation tank 1 is completed, the backwashing to the filter medium 11 is performed. Specifically, the sludge discharge valve connected to the outside of the drain pipe 20 is closed, the air backwash is first performed by opening the backwash air valve, and then the backwash air valve is closed and the backwash valve is opened to perform water backwash. Conduct. Thereafter, the sludge discharge valve connected to the drain pipe 20 is opened to discharge the backwash wastewater. The above backwashing sequence is roughly performed in the order of 2 minutes 30 seconds of offensive, 5 minutes of offensive, 2 minutes 30 seconds of offensive, and 5 minutes of washing of water.

The backwash wastewater collected and transported through the drainage pipe 20 naturally falls into the wastewater collection tank 30 together with the scum sludge collected in the upper part of the flotation tank 1, and then intermittently through the sludge transfer pump. Transferred to and processed.

Example 2

The turbidity of the treated water discharged and the loss rate of the filter medium were measured while changing the slit width formed in the porous drain pipe by changing the slit width formed in Example 1 above. At this time, the slit was constantly formed to be formed only in the range of -60 ° to 60 ° only on both left and right sides based on the center of the longitudinal cross section of the columnar drain pipe having a circular cross section.

The flow rate of the filtration process was kept constant in the range of 30 ~ 40m / hr, backwashing was carried out at a flow rate of 35m / hr. The turbidity of the incoming water was 1.5 ~ 5 NTU, and the solid concentration was 7 ~ 8 mg / L. As the filter medium, a ball media filter made of polypropylene (PP) was used. The average diameter was about 40 mm and the density was 75 ~. 80 kg / m 3, porosity was 96%, and the average pore size was measured to be about 25 μm.

Width of slit (l) 16 cm 10 cm 7.3 cm 6.5 cm Slit to filter media ratio (D / l) 2.5 4 5.5 6.1 Turbidity [NTU] 1.1 0.3 1.3 - Solids content [mg / L] 3 2.1 3.9 - Slit clogging Not blocked Not blocked Not blocked Slit Blockage Missing filter media Filter media loss No filter media loss No filter media loss No filter media loss

As confirmed in the above table, when the width of the slit is too wide, loss of the filter medium occurs, and when the width of the slit is too small, the loss of the filter medium does not occur, but it was confirmed that the slit clogging occurs.

Considering that the turbidity of the raw water introduced is in the range of 1.5 to 5 NTU, when the ratio of the slit to the filter medium (D / l) is 2.5, loss of the filter medium occurs, and the turbidity and the solid content are not sufficiently reduced. there was. In particular, when the width of the slit D / l = 5.5, the turbidity and solids content was increased, which suggests that the backwash is not sufficiently performed, which may reduce the size of the slit. In view of the fact that the blockage of the slit is visually confirmed, even when D / l = 5.5, it may be predicted that the blockage phenomenon occurs in some slit areas, and thus the backwashing process is not performed smoothly.

Therefore, the slits are not clogged without loss of filter media, and in order to maintain the lowest turbidity and solid content, the diameter of the filter media and the width of the slits should be at least greater than 2.5 and less than 5.5.

The present invention is not limited to the above-described specific embodiments and descriptions, and various modifications can be made by those skilled in the art without departing from the gist of the invention as claimed in the claims. Such variations are within the protection scope of the present invention.

A: dissolved air flotation type water treatment device 1: filtration tank, floating tank
1a: An area connected to the drain pipe 20 through one side of the inner wall of the filtration tank (floating tank)
2: flocculation tank 3: precipitation tank
4: treated water storage tank 10: filtration unit
11 filter medium 12 filter medium loss prevention unit
13: lower support 20: drain pipe
20a: transfer pipe 20b: intake pipe
21: intake 22: concrete slab
23 anchor 24 support area
30: wastewater collection tank

Claims (21)

In the drain pipe which is provided inside the filtration tank (1) capable of filtering the contaminants of the raw water is provided inside the filtration unit 10 is filled with a plurality of filter media (11),
In the filtration tank 1, located above the filtration unit 10,
A plurality of slit-shaped intake port 21 is formed on the surface,
Is connected to penetrate one side of the inner wall of the filtration tank (1),
Collect and drain backwash water generated during the back-washing process of the filter medium (11),
The slit-shaped intake port 21 is formed in a slit form only on the outer peripheral surface of -60 ° to 60 ° on both left and right sides with respect to the center of the longitudinal cross section of the circumferential drainage pipe having a circular cross section,
A support region in which a slit-shaped intake port 21 does not exist is formed at the uppermost or lowermost side with respect to the center of the longitudinal cross section of the circumferential drainage pipe having the circular cross section,
The filter medium 11 is a spherical ball filter having a core-shell structure in which the core is a metal alloy and the shell is polypropylene (PP), polyethylene (PE), or polyvinylidene fluoride (PVDF). ball filter)
The ratio D / l of the diameter D of the filter medium 11 and the width l of the slit formed in the intake port 21 is 3 to 5,
Perforated drain pipe 20, characterized in that the interval between the slits formed in the inlet 21 is 20 ~ 30mm. The method of claim 1,
The porous drain pipe 20 is a porous drain pipe 20, characterized in that made of glass fiber reinforced plastic (GRP). delete delete delete delete delete The method of claim 1,
The drain pipe 20 is a porous drain pipe 20, characterized in that fixed to the upper surface of the concrete slab 22 is provided on the upper portion of the filtration unit (10). The method of claim 1,
The drain pipe 20 is at least one water intake provided in the normal direction of the transfer pipe 20a and the transfer pipe 20a connected to one side of the inner wall of the filtration tank 1 and the transfer pipe 20a Porous drain pipe 20, characterized in that it comprises a pipe (20b). The method of claim 1,
The drainage pipe 20 is characterized in that the region (1a) side is installed lower than the opposite side so that the backwash waste water collected in the direction of the region (1a) connected to penetrate one side of the inner wall of the filtration tank 1 to flow naturally. Perforated drainage pipe 20. In the dissolved air floatation (DAF) water treatment apparatus (A) comprising a floating tank (1) for removing contaminants contained in raw water,
A filtration unit 10 provided below the floating tank 1 and filled with a plurality of filter media 11 for filtering contaminants remaining in the treated water from which the pollutants are first removed from the raw water; And
A porous drain pipe 20 provided in the floating tank 1 and installed on the filtration unit 10 to collect and drain backwash water generated during a back-washing process of the filter medium 11; Include,
The surface of the porous drain pipe 20 is formed with a plurality of slit-shaped intake port 21,
The porous drain pipe 20 is connected to be penetrated to one side of the inner wall of the floating tank 1, and the collected backwash water is guided to the wastewater collection tank 30,
The slit-shaped intake port 21 is formed in a slit form only on the outer peripheral surface of -60 ° to 60 ° on both left and right sides with respect to the center of the longitudinal cross section of the circumferential drainage pipe having a circular cross section,
A support region in which a slit-shaped intake port 21 does not exist is formed at the uppermost or lowermost side with respect to the center of the longitudinal cross section of the circumferential drainage pipe having the circular cross section,
The filter medium 11 is a spherical ball filter having a core-shell structure in which the core is a metal alloy and the shell is polypropylene (PP), polyethylene (PE), or polyvinylidene fluoride (PVDF). ball filter)
The ratio D / l of the diameter D of the filter medium 11 and the width l of the slit formed in the intake port 21 is 3 to 5,
The spacing between the slits formed in the intake port 21 is characterized in that 20 ~ 30mm, dissolved air floating water treatment device. The method of claim 11,
The porous drain pipe 20 is a dissolved air flotation type water treatment device, characterized in that made of glass fiber reinforced plastic (GRP). delete delete delete delete delete The method of claim 11,
The drain pipe 20 is fixed to the concrete slab 22 provided on the upper portion of the filter unit 10, characterized in that the dissolved air floating type water treatment device. The method of claim 11,
The drainage pipe 20 is at least one transfer pipe 20a connected to penetrate one side of the inner wall 1 of the floating tank 1 and communicated with the transfer pipe 20a and provided in a normal direction of the transfer pipe 20a. Dissolved air floating water treatment device comprising a water intake pipe (20b). The method of claim 11,
The drainage pipe 20 is characterized in that the region (1a) side is installed lower than the opposite side so that the backwash waste water collected in the direction of the region (1a) connected to penetrate one side of the inner wall of the flotation tank (1). Dissolved air floating water treatment device. The method of claim 11,
Dissolved air floating water treatment device further comprises a filter medium loss prevention part 12 is provided with a porous plate to prevent the filter medium 11 is separated from the outside through the upper portion of the filter unit 10. .

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