KR20210152841A - Filtering apparatus - Google Patents

Abstract

The present invention relates to a filtering device. The filtering device according to an embodiment of the present invention includes: a housing having a space of a set volume therein; a filter unit which is rotationally provided inside the housing, and in which a lower end is positioned upwardly spaced apart by a set distance from the lower end of the housing; a filtered water discharge line connected to the housing to discharge filtered water from the filter unit; and a circulation line providing a path through which the filtered water discharged from the housing is re-introduced into the housing.

Description

Filtering apparatus

The present invention relates to a filtering device, and more particularly, to a filtering device capable of effectively performing filtering and performing both a cleaning process of a filter and a filtering process.

Various types of tanks are used in nuclear power plants. At the bottom of the tank of the radioactive waste treatment system, sludge composed of various organic and inorganic oxides contaminated with radioactive materials may be accumulated, and on the inner wall of the tank, the material and Depending on the application and degree of oxidation, layers of free and adherent oxide contaminants accumulate. Such contaminated sludge is the main cause of exposure to workers when dismantling tanks in nuclear power plants.

In addition, the waste filter generated by the filtration of contaminated sludge is treated as secondary radioactive waste, and this radioactive waste not only occupies a lot of space for disposal, but also the disposal cost is continuously increasing. there is Therefore, for the safe dismantling of the contaminated tank, a device capable of recovering and treating radioactive sludge in advance and minimizing the amount of waste filter generation should be developed due to the contamination characteristics of the sludge existing on the bottom and inner wall of the tank.

There are reverse osmosis, ultrafiltration, microfiltration, etc. as a filtration membrane separation process for removing solid particles in a fluid. Among them, microfiltration is mainly used as a pre-treatment process for finer filtration such as ultrafiltration or a post-treatment process for coarse particle filtration such as granular medium filtration. Microfiltration is a filtration membrane separation process that separates solutes with a solute size of about 0.1 to 10 μm, and the pore diameter of the membrane is about 0.01 to 10 μm. In addition, microfiltration has the advantage that it can be used at a pressure lower than 50 psig (3 bar) because there is no need to overcome the osmotic pressure. However, such a filtration membrane has too small pores to remove sludge, so fouling occurs quickly, and because the durability of the filter material is low, it is easily damaged due to an increase in differential pressure or the filtration function is deteriorated. There is a problem that can be

Although the filtration performance using a filter cloth differs depending on the type of filter cloth, recently, filter cloths capable of removing particles of several μm have been developed. Filter cloths are mainly used in the process of filtering clay particles and sludge from water purification facilities, which are relatively large compared to the size that can be filtered with a filtration membrane, or in filter presses. Filter cloth can be made of various materials such as natural fiber, glass fiber, and synthetic fiber, and can be used in various forms depending on the size and thickness of pores, and it can withstand high pressure, so its durability and safety are higher than other filtration processes.

The types of filters developed to remove sludge from wastewater vary depending on the shape, material, and thickness, and typical examples include cartridge filters and bag filters.

The cartridge filter has a cylindrical structure with a cloth-like string attached, a large filtration area, high collection efficiency, and convenient filter replacement, maintenance, and inspection, and features a small installation area. In general, since it is manufactured for one-time use in order to minimize cleaning of the filter, there is a disadvantage in that the amount of waste filter generated after use is large.

A bag filter is a filter bag made in the form of a bag using materials such as glass fiber, cotton, wool, or synthetic fiber, and is mainly used for pretreatment in the water treatment process. As with cartridge filters, it is difficult to clean the filter, and as the sludge collection and filtration performance deteriorates, a large amount of waste filters are generated due to periodic filter replacement.

Centrifugal filters are used in many industries. Centrifugal filters are used to purify waste oil, wastewater from the grinding of glass and ceramics, or to remove small metal particles from liquids. The liquid remaining after centrifugal filtration can be purified again and reused. This can reduce the amount of waste generated and reduce costs.

As a conventional filter purification technology, techniques such as sludge cake removal through vortex formation, desorption process using spring elasticity, and backwashing are used. It may not be lost, and the process is interrupted as a single filter is used, and even if a double filter is used, temporary interruption of the process is unavoidable.

An object of the present invention is to provide a filtering device capable of effectively separating the introduced raw water into filtered water and sludge.

Another object of the present invention is to provide a filtering device in which washing can be performed while the filter unit is installed in the device, and thus the service life of the filter unit is increased.

Another object of the present invention is to provide a filtering device capable of filtering raw water even in the process of washing the filter unit.

According to an aspect of the present invention, the housing forming a space of a set volume therein; a filter unit rotatably provided inside the housing, the lower end of which is positioned to be spaced apart by a set distance upward from the lower end of the housing; a filtered water discharge line connected to the housing to discharge the filtered water filtered by the filter unit; and a circulation line providing a path through which the filtered water discharged from the housing is re-introduced into the housing may be provided.

In addition, the filter unit, a first filter unit provided in a cylindrical shape having a set length; a second filter unit provided in a cylindrical shape having a set length; and a third filter unit provided in a cylindrical shape having a set length.

In addition, in the housing, a first connection line for connecting the filtered water discharge line and an area vertically aligned with a space in which the first filter unit is located; a second connection line connecting the filtered water discharge line to an area in the housing that is vertically aligned with a space in which the second filter unit is located; and a third connection line connecting the filtered water discharge line and an area vertically aligned with the space in which the third filter unit is located in the housing, wherein both ends of the circulation line are the first connection line and the first connection line, respectively. It can be connected to 3 connecting lines.

In addition, it may further include a circulation auxiliary line connecting the circulation line and the housing.

In addition, the circulation auxiliary line may be connected to a region in the housing that is vertically aligned with a space in which the second filter unit is located.

According to an embodiment of the present invention, a filtering device capable of effectively separating the introduced raw water into filtered water and sludge may be provided.

In addition, according to an embodiment of the present invention, washing can be performed while the filter unit is installed in the device, and accordingly, a filtering device in which the service life of the filter unit is increased can be provided.

In addition, according to an embodiment of the present invention, a filtering device capable of filtering raw water even in the process of washing the filter unit may be provided.

1 is a diagram illustrating a filtering device according to an embodiment of the present invention.
FIG. 2 is a top plan view of the filtering device of FIG. 1 ;
FIG. 3 is a bottom view of a filter unit of the filtering device of FIG. 1 .
FIG. 4 is a view showing an upper portion of the filtering device of FIG. 1 .
5 is a view showing a state in which the third filter unit is washed while circulation is made between the second filter unit and the third filter unit.
6 is a view illustrating a state in which the first filter unit is washed while circulation is made between the first filter unit and the third filter unit.
7 is a view illustrating a state in which the second filter unit is washed while circulation is made between the first filter unit and the second filter unit.
8 is a diagram illustrating a filtering apparatus according to another exemplary embodiment.

Hereinafter, an embodiment of the present invention will be described in more detail with reference to the accompanying drawings. Embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited to the following embodiments. This embodiment is provided to more completely explain the present invention to those of ordinary skill in the art. Accordingly, the shapes of elements in the drawings are exaggerated to emphasize a clearer description.

1 is a view showing a filtering device according to an embodiment of the present invention, FIG. 2 is a plan view of an upper portion of the filtering device of FIG. 1 , FIG. 3 is a bottom view of a filter unit of the filtering device of FIG. 1 , and FIG. 4 is It is a view showing the upper part of the filtering device of FIG.

For convenience of illustration, a portion of the piping and valve configuration in FIG. 2 is omitted.

1 to 4 , the filtering device 1 includes a body part 2 and a pipe part 3 .

The filtering device (1) filters the incoming raw water, and separates it into filtered water and sludge and discharges it. The raw water subject to inflow may be wastewater generated during the operation of facilities such as nuclear power plants.

The main body 2 performs a filtration process on the raw water introduced into it, and separates the raw water into filtered water and sludge. The body part includes a housing 10 and a filter part 20 .

The housing 10 is provided to define a space of a set volume therein. The cross-section of the inner space of the housing 10 may be provided in a circular shape. The cross-sectional area of the inner space of the housing 10 is formed to be smaller in the lower part than the upper part. For example, the inner space of the housing 10 may be provided as a whole or a part of the lower portion in a conical shape. An inlet line 15 is connected to the upper portion of the housing 10 . An inlet valve (not shown) may be located in the inlet line 15 . Raw water to be filtered is introduced into the housing 10 through the inlet line 15 .

The filter unit 20 is rotatably provided inside the housing 10 . The filter unit 20 is spaced apart from the inner wall of the housing 10 by a set distance, and a gap of a set size is formed between the outer surface of the filter unit 20 and the inner wall of the housing 10 .

The filter unit 20 is positioned to be spaced apart from the lower end of the inner space of the housing 10 by a set distance upward. The filter unit 20 is connected to the upper wall of the housing 10 and may be provided to have a set length vertically. Cylindrical partition walls 11a, 11b, and 11c are provided around the outer periphery of the filter unit 20, and the filter unit 20 may be provided in a form accommodated in the inner space of the partition walls 11a, 11b, 11c. . The upper ends of the partition walls 11a, 11b, and 11c are fixed to the housing 10, and the lower ends of the partition walls 11a, 11b, 11c are provided to be spaced apart from the bottom surface of the housing 10 by a set distance upward. At this time, the inner space of the partition walls 11a, 11b, and 11c is provided to have a larger area than the outer circumference of the filter unit 20, and between the inner surfaces of the partition walls 11a, 11b, and 11c and the filter unit 20, A gap of a set size is formed. In addition, the outer surfaces of the partition walls 11a, 11b, and 11c are positioned to be spaced apart from the inner surface of the housing 10 by a set distance. Support rods 25a, 25b, and 25c are provided between the lower ends of the inner surfaces of the partition walls 11a, 11b, and 11c and the lower end of the filter unit 20 to support the lower end of the filter unit 20 . A plurality of support rods 25a, 25b, and 25c may be provided in the circumferential direction of the filter unit 20 . 3 shows a case in which four support rods 25a, 25b, and 25c are provided.

The filter unit 20 includes a first filter unit 21 , a second filter unit 22 , and a third filter unit 23 .

The first filter unit 21 may be provided in a cylindrical shape having a set length in the vertical direction. The first filter unit 21 is rotatably provided by the first rotation shaft 211 provided in the vertical direction. The upper end of the first rotating shaft 211 penetrates the upper wall of the housing 10 and extends into the outer space of the housing 10 , and the lower end of the first rotating shaft 211 is supported by the first support rod 25a. . An upper end and a lower end of the first rotation shaft 211 may be connected by a bearing 26 . An upper end of the first rotation shaft 211 is connected to the first driving member 210 outside the housing 10 . The first driving member 210 provides power to rotate the first rotation shaft 211 . For example, the first driving member 210 may be provided as a motor or the like. The first driving member 210 is detachably connected to the housing 10 by a first flange 27a. Accordingly, when the first flange 27a is separated, the first driving member 210 and the first filter unit 21 may be separated from the housing 10 and drawn out, so that the first driving member 210 ) and the first filter unit 21 can be easily replaced. A first filtered water collection tank 12a is formed in the upper portion of the housing 10, which is arranged vertically in the inner space of the first partition wall 11a.

The second filter unit 22 may be provided in a cylindrical shape having a set length in the vertical direction. The second filter unit 22 is rotatably provided by a second rotation shaft 221 provided in the vertical direction. The upper end of the second rotation shaft 221 passes through the upper wall of the housing 10 and extends into the outer space of the housing 10 , and the lower end of the second rotation shaft 221 is supported by the second support rod 25b. . An upper end and a lower end of the second rotation shaft 221 may be connected by a bearing 26 . The upper end of the second rotation shaft 221 is connected to the second driving member 220 outside the housing 10 . The second driving member 220 provides power to rotate the second rotation shaft 221 . For example, the second driving member 220 may be provided as a motor or the like. The second driving member 220 is detachably connected to the housing 10 by a second flange 27b. Accordingly, when the second flange 27b is separated, the second driving member 220 and the second filter unit 22 may be separated from the housing 10 and drawn out, so that the second driving member 220 ) and the second filter unit 22 can be easily replaced. A second filtered water collection tank 12b is formed on the upper portion of the housing 10, which is arranged vertically in the inner space of the second partition wall 11b.

The third filter unit 23 may be provided in a cylindrical shape having a set length in the vertical direction. The third filter unit 23 is rotatably provided by a third rotation shaft 231 provided in the vertical direction. The upper end of the third rotating shaft 231 penetrates the upper wall of the housing 10 and extends into the outer space of the housing 10 , and the lower end of the third rotating shaft 231 is supported by the third support rod 25c. . An upper end and a lower end of the third rotation shaft 231 may be connected by a bearing 26 . The upper end of the third rotation shaft 231 is connected to the third driving member 230 from the outside of the housing 10 . The third driving member 230 provides power to rotate the third rotation shaft 231 . For example, the third driving member 230 may be provided as a motor or the like. The third driving member 230 is detachably connected to the housing 10 by a third flange 27c. Accordingly, when the third flange 27c is separated, the third driving member 230 and the third filter unit 23 may be separated from the housing 10 and drawn out, so that the third driving member 230 may be drawn out. ) and the third filter unit 23 can be easily replaced. A third filtered water collection tank 12c is formed in the upper portion of the housing 10, which is arranged vertically in the inner space of the third partition wall 11c.

A drain line 30 is connected to the lower end of the housing 10 . The drain line 30 discharges the sludge separated from the raw water introduced into the housing 10 . A sludge valve 300 may be located in the drain line 30 .

The pipe part 3 is connected to the body part 2 to provide a path through which the filtered water discharged from the body part 2 flows. The pipe part 3 includes a filtered water discharge line 50 and a circulation line 60 .

The filtered water discharge line 50 is connected to the housing 10 to discharge the filtered water filtered by the filter unit 20 .

The filtered water discharge line 50 is connected to the upper part of the housing 10 by a first connection line 51 , a second connection line 52 , and a third connection line 53 . The first connection line 51 may be connected to an area (ie, the first filtered water collection tank 12a) that is vertically aligned with the space where the first filter unit 21 is located. A first valve 510 is positioned on the first connection line 51 .

The second connection line 52 may be connected to an area (ie, the second filtered water collection tank 12b) that is vertically aligned with the space where the second filter unit 22 is located. A second valve 520 is positioned on the second connection line 52 .

The third connection line 53 may be connected to an area (ie, the third filtered water collection tank 12c) that is vertically aligned with the space in which the third filter unit 23 is located. A third valve 530 is positioned on the third connection line 53 .

The circulation line 60 provides a path through which the filtered water discharged from the housing 10 is re-introduced into the housing 10 . Both ends of the circulation line 60 are respectively connected to the first connection line 51 and the third line. The circulation line 60 has one end connected to the first connection line 51 in the upstream region of the first valve 510 . The other end of the circulation line 60 is connected to the third connection line 53 in the upstream region of the third valve 530 . The circulation line 60 is connected to the upper part of the housing 10 by a circulation auxiliary line 62 . The circulation auxiliary line 62 may be connected to an area (ie, the second filtered water collection tank 12b) that is vertically aligned with the space where the second filter unit 22 is located. A first circulation valve 601 and a third circulation valve 603 are located in the circulation line 60 . The first circulation valve 601 is located in the direction of the first connection line 51 based on the area connected to the circulation auxiliary line 62 . The third circulation valve 603 is positioned in the direction of the third connection line 53 with respect to the area connected to the circulation auxiliary line 62 . A second circulation valve 622 is located in the circulation auxiliary line 62 .

Hereinafter, an operation process of the filtering device 1 will be described. Raw water to be filtered is introduced through the inlet line 15 . The raw water may be introduced in a steady state flow state.

In a normal state, filtration may be performed while all of the first filter unit 21 , the second filter unit 22 , and the third filter unit 23 operate. Accordingly, by the first driving member 210 , the second driving member 220 , and the third driving member 230 , the first filter unit 21 , the second filter unit 22 and the third filter unit ( 23) is rotated. At this time, the first valve 510 , the second valve 520 , and the third valve 530 are opened, and the first circulation valve 601 , the second circulation valve 622 and the third circulation valve 603 are opened. is provided closed.

In the raw water introduced into the housing 10 , some sludge is settling by gravity and discharged to the drain line 30 . In addition, a vortex and centrifugal force are formed by the rotation of the first filter unit 21, the second filter unit 22, and the third filter unit 23, and the sludge contained in the raw water is transferred to the housing 10 and the partition wall 11a. , 11b, 11c) and coagulation between the sludges and gravitational sedimentation can occur.

In addition, the sludge contained in the raw water may be physically captured and removed by the filter cloth filters of the first filter unit 21 , the second filter unit 22 , and the third filter unit 23 . Then, the raw water passes through the filter cloth filters of the first filter unit 21 , the second filter unit 22 and the third filter unit 23 , and then the first connection line 51 , the second connection line 52 . and a third connection line 53 . The sludge dropped by the above complex mechanism may be discharged through the drain line 30 .

In addition, as the partition walls 11a, 11b, and 11c are provided, the raw water has an inertial collision in the space between the partition walls 11a, 11b, 11c and the housing 10, and the effect of primary filtration through sludge coagulation increases. Then, after the raw water is introduced into the inside of the partition walls 11a, 11b, and 11c in the lower region of the housing 10, filtration by the filter unit 20 may be performed.

5 is a view illustrating a state in which the third filter unit is washed while circulation is made between the second filter unit and the third filter unit.

The valve in the closed state is shown in FIG. 5, and the valve in the open state is omitted.

Referring to FIG. 5 , the first valve 510 , the second circulation valve 622 , and the third circulation valve 603 are opened, and the second valve 520 , the third valve 530 and the first circulation valve are opened. 601 is provided in a closed state. In addition, the first driving member 210 and the third driving member 230 operate, and the second driving member 220 is provided in a stationary state. According to the operation of the third driving member 230 , the third filter unit 23 is rotated. With the centrifugal force caused by the rotation of the third filter unit 23 , a flow of fluid from the inside to the outside is generated in the third filter unit 23 , and the resulting water pressure is used to filter the filter in the filter cloth filter of the third filter unit 23 . Washing is performed as the cake is detached. In addition, according to the pressure drop on the inside of the third filter unit 23 , the flow of the fluid is formed in the direction from the circulation auxiliary line 62 to the third connection line 53 . In addition, in response to the amount of raw water supplied through the inlet line 15 , the filtered water is driven to be discharged through the first connection line 51 , so that even in the process of washing the filter unit 20 , the filtering device 1 ) of raw water filtration process can be performed.

Also, in the open/closed state of the valve as shown in FIG. 5 , the first driving member 210 and the second driving member 220 may operate, and the third driving member 230 may operate in a stopped state. Accordingly, in a manner similar to the above-described process, a flow of fluid from the third connection line 53 toward the circulation auxiliary line 62 occurs, and the cleaning of the second filter unit 22 is performed.

6 is a view illustrating a state in which the first filter unit is washed while circulation is made between the first filter unit and the third filter unit.

The valve in the closed state is shown in FIG. 6, and the valve in the open state is omitted.

Referring to FIG. 6 , the second valve 520 , the first circulation valve 601 and the third circulation valve 603 are opened, and the first valve 510 , the third valve 530 and the second circulation valve are opened. 622 is provided in a closed state. In addition, the first driving member 210 and the second driving member 220 are operated, and the third driving member 230 is provided in a stationary state. According to the operation of the first driving member 210 , the first filter unit 21 is rotated. By the centrifugal force caused by the rotation of the first filter unit 21 , a flow of fluid from the inside to the outside is generated in the first filter unit 21 , and the water pressure by this creates a filter in the filter cloth filter of the first filter unit 21 . Washing is performed as the cake is detached.

In addition, according to the pressure drop inside the first filter unit 21 , the flow of the fluid is formed in the direction from the third connection line 53 to the first connection line 51 through the circulation line 60 .

In addition, in response to the amount of raw water supplied through the inlet line 15 , the filtered water is driven to be discharged through the second connection line 52 , so that even in the process of washing the filter unit 20 , the filtering device 1 ) of raw water filtration process can be performed.

Also, in the open/closed state of the valve as shown in FIG. 6 , the second driving member 220 and the third driving member 230 may operate, and the first driving member 210 may operate in a stopped state. Accordingly, in a manner similar to the above-described process, a flow of fluid from the first connection line 51 through the circulation line 60 toward the third connection line 53 occurs, and the third filter unit 23 . washing is performed.

7 is a view illustrating a state in which the second filter unit is washed while circulation is made between the first filter unit and the second filter unit.

The valve in the closed state is shown in FIG. 7, and the valve in the open state is omitted.

Referring to FIG. 7 , the third valve 530 , the first circulation valve 601 and the second circulation valve 622 are opened, and the first valve 510 , the second valve 520 and the third circulation valve are opened. 603 is provided in a closed state. In addition, the second driving member 220 and the third driving member 230 operate, and the first driving member 210 is provided in a stationary state. According to the operation of the second driving member 220 , the second filter unit 22 is rotated. With the centrifugal force generated by the rotation of the second filter unit 22 , a fluid flow from the inside to the outside is generated in the second filter unit 22 , and the resulting water pressure is used to filter the filter in the filter cloth filter of the second filter unit 22 . Washing is performed as the cake is detached.

In addition, according to the pressure drop inside the second filter unit 22 , the flow of the fluid is formed in the direction from the first connection line 51 to the circulation line 60 through the circulation auxiliary line 62 .

In addition, in response to the amount of raw water supplied through the inlet line 15 , the filtered water is driven to be discharged through the third connection line 53 , so that even in the process of washing the filter unit 20 , the filtering device 1 ) of raw water filtration process can be performed.

Also, in the open/closed state of the valve as shown in FIG. 7 , the first driving member 210 and the third driving member 230 may operate, and the second driving member 220 may operate in a stopped state. Accordingly, in a manner similar to the above-described process, a flow of fluid from the circulation auxiliary line 62 to the first connection line 51 through the circulation line 60 occurs, and the first filter unit 21 Washing is performed.

8 is a diagram illustrating a filtering apparatus according to another exemplary embodiment.

Referring to FIG. 8 , the filtering device 1a includes a body portion 2a and a pipe portion 3a.

The body portion 2a includes housings 10a, 10b, and 10c and a filter portion 20a.

The housings 10a, 10b, and 10c include a first housing portion 10a, a second housing portion 10b, and a third housing portion 10c.

The first housing portion 10a is provided to form a space of a set volume therein. A cross-section of the inner space of the first housing part 10a may be provided in a circular shape. The cross-sectional area of the inner space of the first housing part 10a is formed to be smaller in the lower part than the upper part. For example, the inner space of the first housing portion 10a may be provided in a conical shape in whole or in part of the lower portion. A first inlet line 15a is connected to an upper portion of the first housing portion 10a.

The second housing portion 10b is provided to form a space of a set volume therein. A cross-section of the inner space of the second housing part 10b may be provided in a circular shape. The cross-sectional area of the inner space of the second housing part 10b is formed to be smaller in the lower part than the upper part. For example, the inner space of the second housing portion 10b may be provided in a conical shape in whole or in part of the lower portion. A second inlet line 15b is connected to an upper portion of the second housing portion 10b.

The third housing portion 10c is provided to form a space of a set volume therein. A cross-section of the inner space of the third housing portion 10c may be provided in a circular shape. The cross-sectional area of the inner space of the third housing part 10c is formed to be smaller in the lower part than the upper part. For example, the entire or part of the inner space of the third housing part 10c may be provided in a conical shape. A third inlet line 15c is connected to the upper portion of the third housing portion 10c.

The filter unit 20a includes a first filter unit 21a, a second filter unit 22a, and a third filter unit 23a.

The first filter part 21a is located inside the first housing part 10a.

The second filter part 21b is located inside the second housing part 10b.

The third filter part 21c is located inside the third housing part 10c.

Others The configuration of the body portion 2a and the pipe portion 3a, which are not described in this embodiment, are the same as or similar to those of the filtering device 1 of FIG. 1 , so a repeated description will be omitted.

The above detailed description is illustrative of the present invention. In addition, the above description shows and describes preferred embodiments of the present invention, and the present invention can be used in various other combinations, modifications, and environments. That is, changes or modifications are possible within the scope of the concept of the invention disclosed herein, the scope equivalent to the written disclosure, and/or within the scope of skill or knowledge in the art. The written embodiment describes the best state for implementing the technical idea of the present invention, and various changes required in specific application fields and uses of the present invention are possible. Accordingly, the detailed description of the present invention is not intended to limit the present invention to the disclosed embodiments. Also, the appended claims should be construed to include other embodiments.

2: body part 3: piping part
10: housing 20: filter unit
21: first filter unit 22: second filter unit
23: third filter unit 30: drain line
50: discharge line 51: first connection line
52: second connecting line 53: third connecting line
60: circulation line

Claims (5)

a housing defining a space of a set volume therein;
a filter unit rotatably provided inside the housing, the lower end of which is positioned to be spaced apart from the lower end of the housing by a set distance upward;
a filtered water discharge line connected to the housing to discharge the filtered water filtered by the filter unit; and
and a circulation line providing a path through which the filtered water discharged from the housing is re-introduced into the housing. According to claim 1,
The filter unit,
a first filter unit provided in a cylindrical shape having a set length;
a second filter unit provided in a cylindrical shape having a set length; and
A filtering device including a third filter unit provided in a cylindrical shape having a set length. 3. The method of claim 2,
a first connection line connecting the filtered water discharge line to an area in the housing that is vertically aligned with a space in which the first filter unit is located;
a second connection line connecting the filtered water discharge line to an area in the housing that is vertically aligned with a space in which the second filter unit is located; and
Further comprising a third connection line connecting the area in which the third filter unit is located in the housing and the area aligned vertically with the filtered water discharge line,
A filtering device in which both ends of the circulation line are connected to the first connection line and the third connection line, respectively. 4. The method of claim 3,
Filtering device further comprising a circulation auxiliary line connecting the circulation line and the housing. 5. The method of claim 4,
The circulation auxiliary line is connected to a region in the housing that is vertically aligned with a space in which the second filter unit is located.

Images