KR102820526B1 - Filtration system and filtration method thereof - Google Patents

Abstract

The filtration system according to the disclosed present invention is for primary (pretreatment) filtering of raw water, and includes a pretreatment filter (200) having a drum filter structure, a filter medium tank (400) for generating a filter medium mixture by mixing primary treated water passing through the pretreatment filter (200) and powdered filter medium, and a main filter (500) for receiving the filter medium mixture water passing through the filter medium tank (400) through a main supply pipe (610) and coating a vertically arranged fiber filter (550), and after the coating process is completed, for secondary filtering the primary treated water passing through the pretreatment filter using the fiber filter (550) coated with the filter medium.

Description

Filtration system and filtration method thereof {Filtration system and filtration method thereof}

The present invention relates to a filtration system for filtering foreign substances contained in raw water and a filtration method using the same.

In general, water treatment methods for filtering out foreign substances contained in raw water are divided into biological treatment that removes organic substances through microorganisms, chemical treatment that removes heavy metals through chemicals, and physical treatment that removes contaminants and solids through machines such as screens, depending on the treatment principle.

Here, the filtration process, which is one of the physical treatments, is a process in which raw water containing foreign substances including pollutants is introduced into a filtration device, and the foreign substances are filtered out by a separate filter medium or filter member to discharge clean treated water.

Pre-coating filters, which are one of the physical filtration processes, have a problem in that filtration is performed by a number of filters, filtration is performed by a filter medium coated on the outside of the filter, and filtration performance deteriorates as the pores of the filter medium become blocked due to continuous filtration, increasing filtration resistance.

Accordingly, taking this into consideration, Patent Registration No. 10-2143508 discloses a technology for detaching filter media and foreign substances attached to the outside of a pre-coating filter by high-pressure backwashing water and the shaking of a filter rotation device, and further, the prior art discloses a technology for detaching filter media and foreign substances that have not been detached and remained on the outside of the filter cloth of the pre-coating filter by installing a high-pressure injection unit that is arranged to surround the outside of the pre-coating filter in the filter and injects high-pressure backwashing water or air into the inside of the pre-coating filter.

However, in the above prior art, the filter rotation device has a complex configuration and has the problem of increased cost, and in addition, in the case of the high-pressure injection unit, the pre-coating filters are arranged in tens to hundreds of layers. The pre-coating filters arranged close to the high-pressure injection unit have a certain degree of detachment effect, but the pre-coating filters arranged farther away, that is, inwardly, have a problem in that the detachment effect is minimal or almost nonexistent because the air does not reach them.

Meanwhile, in the above prior art, a reverse-washing water supply device is provided to supply reverse-washing water to the reverse-washing water inside the pre-coating filter. However, since the tube for supplying reverse-washing water to the inside of the body (filtration tank) is installed in the center, there is a problem in that reverse-washing water is not supplied well to the pre-coating filter arranged toward the inner wall of the body (filtration tank).

Patent Registration No. 10-2143508 (Published on August 11, 2020) Patent Registration No. 10-1009439 (Publicly Announced on January 19, 2011)

The present invention has been made in consideration of the above points, and its purpose is to provide a filtration system and a filtration method using the same, which has a simple configuration and enables even and thorough cleaning of the filter.

In addition, another purpose of the present invention is to provide a filtration system and a filtration method using the same, which enable a filter material to be well coated on a filter and also extend the filtration life of the filter.

According to the present invention for achieving the above object, a filtration system for primary (pretreatment) filtering of raw water comprises: a pretreatment filter having a drum filter structure; a filter tank for generating a filter medium mixture by mixing primary treated water passing through the pretreatment filter and powdered filter medium; and a main filter for receiving the filter medium mixture water passing through the filter tank through a main supply pipe and coating it on a vertically arranged fiber filter, and after the coating process is completed, for secondary filtering the primary treated water passing through the pretreatment filter using the fiber filter coated with the filter medium.

The above main filter comprises: a body having an inlet for introducing the primary treated water and the filter material mixture on one side, and a drainage port on the bottom; an upper cover coupled to the upper part of the body and having a through hole formed in the center; a filter coupling plate positioned inside the body to be coupled to the body and the upper cover, and having a plurality of coupling holes formed therethrough to allow the fiber filters to be coupled respectively; a raw water distributor positioned inside the body to be connected to the inlet and to evenly supply the primary treated water and the filter material mixture into the interior of the body; an air bubble generator arranged above the raw water distributor, having a spiral tube structure and having micro-holes formed at regular intervals to generate air bubbles in the primary treated water and the filter material mixture by ejecting air supplied from an air supply device outside the body into the micro-holes; a branch pipe connected to the upper part of the through hole; A filtration system characterized by comprising: a purified water discharge pipe connected to one side of the branch pipe and through which purified water that has escaped from the body through the through hole has been discharged; a backwash water supply pipe connected to the other side of the branch pipe and the main supply pipe and supplying primary treated water supplied from the pretreatment filter as backwash water into the interior of the body through the through hole; and a filter mixed water circulation pipe connected to the purified water discharge pipe and the filter tank and through which filter mixed water that has escaped from the body through the through hole has been introduced into the filter tank and circulated back into the body.

In addition, the filtration system according to the present invention further includes a backwash water equalization supply device, which is connected to the lower portion of the through hole of the upper cover and includes a central branch pipe for supplying backwash water to the central portion of the body and a plurality of outer branch pipes installed at regular intervals for supplying backwash water in the circumferential direction of the inner wall of the body so as to uniformly supply backwash water into the interior of the body.

Meanwhile, a filtration method according to the present invention for achieving the above object relates to a filtration method using the filtration system, comprising: a) a pre-treatment filtration step of primarily filtering raw water by the pre-treatment filter; b) a filter material coating step of mixing primary treated water passing through the pre-treatment filter and a certain amount of powdered filter material in a filter material tank to generate a filter material mixture, and then supplying the filter material mixture to the main filter to coat the filter material included in the filter material mixture on the fiber filter; c) a main filtration step of supplying the primary treated water passing through the pre-treatment filter to the main filter and allowing it to pass through the fiber filter after the filter material coating step is completed, thereby filtering; d) a detachment process of stopping the operation of supplying the primary treated water to the main filter when a set pressure value and flow rate value are reached, and detaching contaminants attached to the fiber filter multiple times; And, e) a backwashing process including, after the detachment step, a backwashing process for removing contaminants attached to the fiber filter by supplying backwashing water in the reverse direction of the main filtration step; characterized in that it includes;

The step b) above is to repeat the process of supplying the filter media mixture to the main filter, then sending the discharged water from the main filter to the filter media tank, and then supplying it again to the main filter for a certain period of time.

In addition, during the process of circulating the filter media mixture through the main filter, air bubbles are generated through the air bubble generator to cause the filter media to float and evenly coat the fiber filter.

Meanwhile, in the step e), air bubbles are generated through the air bubble generator during reverse oscillation, but the air bubbles are generated at a greater value than in the step b).

According to the present invention, by generating air bubbles during filter material coating and reverse washing, the filter material can be well coated on the fiber filter, and the fiber filter can be well washed.

In addition, according to the present invention, when supplying backwash water, the backwash water is evenly supplied to the filter, especially the outer filter located on the inner wall of the body, so that the backwash water can be uniformly supplied into the interior of the body, thereby achieving uniform backwashing.

In addition, since the present invention installs a pre-treatment filter before the main filter to perform a primary filtering of raw water, it has the effect of protecting the fiber filter of the main filter and extending the time until the backwashing process.

Figure 1 is a diagram showing the overall configuration of a filtration system according to an embodiment of the present invention.
Figure 2 is an enlarged view of the main filter of Figure 1.
Figure 3 is an internal cross-sectional view of the main filter of Figure 2.
Figure 4 is an enlarged view of the treatment water distributor installed inside the main filter of Figure 3.
Figure 5 is an enlarged view of the air bubble generator installed inside the main filter of Figure 3.
Figure 6 is a flow chart of a filtration method according to an embodiment of the present invention.

The above objects, features and other advantages of the present invention will become more apparent by describing in detail a preferred embodiment of the present invention with reference to the accompanying drawings. Hereinafter, a filtration system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1, a filtration system according to an embodiment of the present invention includes a pretreatment filter (200), a filter tank (400), and a main filter (500).

The pretreatment filter (200) is for primary (pretreatment) filtering of raw water requiring filtration, and the raw water supplied by the first pump (100) undergoes primary filtration through the pretreatment filter (200). The pretreatment filter (200) has a conventional drum filter structure. The drum filter structure filters foreign substances contained in the raw water through a cylindrical dream filter driven by a motor, as disclosed in, for example, Korean Patent Publication No. 10-1009439. According to an embodiment of the present invention, the drum filter can apply a screen mesh having a size of approximately 30 μm.

Since the pretreatment filter (200) of this type primarily filters out relatively large foreign substances contained in the raw water, it is possible to protect and extend the life of the fiber filter installed in the main filter (500) described later, thereby significantly reducing maintenance costs. In addition, by installing the pretreatment filter (200), the removal and backwashing arrival time (cycle) of the main filter (500) is lengthened, so that situations where the supply of treated water to a place where the pretreatment filter (200) is installed, for example, a fish farm, is interrupted can be significantly reduced.

The pretreatment filter (200) and the main filter (500) are connected through the main supply pipe (610), so the primary treated water that has passed through the pretreatment filter (200) is supplied to the main filter (500) through the main supply pipe (610) by the second pump (300) and undergoes secondary filtration.

The filter tank (400) is installed on the path of the main supply pipe (610) to generate a filter material mixture by mixing the primary treated water that has passed through the pretreatment filter (200) and the filter material, and supply the filter material to the main filter (500). That is, in order for the main filter (500) to perform a filtration process, a work of coating the fiber filter (550, see FIG. 3) that is installed in the main filter (500) and performs filtration with the filter material must be performed first. To this end, the filter material tank (400) supplies the filter material mixture before performing the filtration process with the main filter (500) so that the filter material can be coated on the fiber filter (550). The filter material tank (400) is connected to the main supply pipe (610) by a connecting pipe (not shown), and thus, the filter material mixture mixed in the filter material tank (400) flows into the main filter (500) through the main supply pipe (610).

According to an embodiment of the present invention, diatomaceous earth having a particle size of approximately 200 mesh (0.074 mm) may be used as the filter medium, and thus, in the filter medium tank (400), the primary treated water that has passed through the pretreatment filter (200) and the powdered filter medium are sufficiently mixed to generate a filter medium mixed water. In order for the primary treated water and the filter medium to be well mixed, air bubbles may be generated.

According to this embodiment, the primary treated water that has passed through the pretreatment filter (200) and the filter material are mixed in the filter material tank (400) to produce a filter material mixed water. However, this is not limited to this, and it is also possible to produce a filter material mixed water by mixing separate water and filter material. However, in this case, since separate pipes and pumps are required, the structure of the system becomes complicated, and therefore, it is preferable to mix the primary treated water that has passed through the pretreatment filter (200) and the filter material as in this embodiment.

The main filter (500) filters the primary treated water that has passed through the pretreatment filter (200) after the coating process is completed for a second time using the fiber filter (550).

Referring to FIGS. 1 to 5, the main filter (500) specifically includes a body (510), an upper cover (520), a reverse-washing water equalization supply (530), a filter combination plate (540) to which a fiber filter (550) is combined, a treated water distributor (560), and an air bubble generator (570).

The body (510) has a cylindrical shape with an open top, and an inlet (512) is provided on one lower side to allow primary treated water that has passed through a pretreatment filter (200) and filter material mixed water that has passed through a filter material tank (400) to flow in, and a drain (514) is provided on the lower side to discharge water and foreign substances inside the body (510).

And, the treated water distributor (560) is arranged inside the body (510) so as to be connected to the inlet (512), so as to evenly distribute and introduce the primary treated water and filtered water mixed water flowing in through the inlet (512) into the body (510). To this end, as illustrated in FIG. 4, the treated water distributor (560) is composed of a circular distribution pipe (562) and a cross distribution pipe (564) positioned inside the circular distribution pipe (562), and the circular distribution pipe (562) and the cross distribution pipe (564) have cut grooves (566) formed at regular intervals, through which the primary treated water and filtered water mixed water are discharged and distributed into the body (510).

The upper cover (520) is attached to the upper part of the body (510), and a through hole (522) is formed in the central portion. During the filtration process, filtered water from the body (510) is discharged through the through hole (522), and during the backwash process, backwash water is supplied through the through hole (522) and flows into the inside of the body (510).

To this end, a T-shaped branch pipe (650) is connected to the upper portion of the through hole (522) outside the body (510), and a purified water discharge pipe (640) for discharging purified water filtered from the body (510) and a reverse-wash water supply pipe (630) for supplying reverse-wash water into the body (510) are connected to the branch pipe (650). Meanwhile, a filter mixture water circulation pipe (620) connected to a filter tank (400) is connected along the path of the purified water discharge pipe (640). Therefore, during the filter mixture coating process, the filter mixture water introduced into the body (510) through the inlet (512) passes through the filter mixture water circulation pipe (620) and flows into the filter tank (400) and then flows back into the body (510), repeating the circulation process.

Meanwhile, a backwash water equalization supply device (530) is installed at the bottom of the through hole (522) of the upper cover inside the body (510). The backwash water equalization supply device (530) has multiple branch pipes arranged to supply backwash water evenly into the body (510) when supplying backwash water. Specifically, it includes one central branch pipe (532) for supplying to the central portion of the body (510), and multiple outer branch pipes (534) installed at regular intervals for supplying to the circumferential direction of the inner wall of the body (510).

In the case of the prior art disclosed in the aforementioned registered patent publication No. 10-2143508, the backwash water is supplied into the body through a single inlet pipe (purified water discharge pipe) installed in the center. In this case, there was a problem that the backwash water was not supplied evenly to the filter, especially the outer filter located on the inner wall of the body. However, according to the backwash water equalization supply device (530) of the present invention, the backwash water can be supplied evenly to the fiber filter, thereby achieving uniform backwashing.

The filter coupling plate (540) is positioned inside the body so as to be placed between the body (510) and the upper cover (520) when they are coupled, and a number of coupling holes for coupling the fiber filter (550) are formed through the body.

The fiber filter (550) is respectively connected to the above-described plurality of joining holes and positioned in a state of extending in the height direction inside the body (510). The fiber filter (550) is provided with a cylindrical filter cloth having a hollow interior, and an elastic body may be connected to the interior of the filter cloth. The structure of the filter joining plate (540) and the fiber filter (550) is similar to the filter joining plate and filter disclosed in the above-described prior art, so a detailed description thereof will be omitted.

The air bubble generator (570) is placed above the treated water distributor (560), and as shown in Fig. 5, has a spiral tube structure and micro-holes (572) are formed at regular intervals so that air supplied from an external air supply (600) is ejected through the micro-holes. The air generated from the air bubble generator (570) combines with water to generate air bubbles, thereby playing a certain role.

Specifically, it performs the function of washing the contaminated filter medium coated on the fiber filter (550) by generating air bubbles during the reverse washing process. In addition, since the filter medium has a characteristic of settling under the body during the filter medium coating process, an appropriate amount of fine air bubbles is generated to facilitate the floatation of the filter medium, thereby performing a uniform coating on the fiber filter (550) vertically arranged inside the body (510). The amount of air generated is different during the reverse washing process and the filter medium coating process, and for this purpose, an inverter is installed in the air supply device (600) to control the amount of air supplied.

Hereinafter, a filtration method using a filtration system according to an embodiment of the present invention having the above configuration will be described with reference to FIGS. 1 to 6.

A filtration method according to an embodiment of the present invention includes a pretreatment filtration step (S10), a filter coating step (S20), a main filtration step (S30), a desorption step (S40), and a backwashing step (S50).

The pretreatment filtration step (S10) first filters the raw water by the pretreatment filter (200), and most of the floating substances in the raw water can be filtered by this process. The pretreatment filtration process has the advantage of protecting the fiber filter of the main filter (500) and extending the time until the backwashing process.

In the filter material coating step (S20), the primary treated water that has passed through the pretreatment filter (200) and a certain amount of powdered filter material are mixed in a filter material tank (400) to generate a filter material mixture, and then the filter material mixture is supplied to the main filter (500) to coat the filter material contained in the filter material mixture on the fiber filter. That is, the filter material mixture mixed in the filter material tank (400) flows into the inlet (512) of the main filter (50) through the treated water distributor (560) and into the body (510) of the main filter (500) to fill the body (510). In the process of filling the body (510), the filter material contained in the filter material mixture is attached to the outside of the fiber filter (550) to form a coating.

The filter media mixture filled in the body (510) passes through the through hole (522) and the backwash water equalization supply (530) by the pressure of the second pump (300), flows through the filter media mixture circulation pipe (620), enters the filter media tank (400), and circulates back into the body (510). This process is repeated for a certain period of time (approximately 30 minutes) to coat the fiber filter. In the filter media coating step (S20), the valves (642, 632) installed in the purified water discharge pipe (640) and the backwash water supply pipe (630) are closed, respectively.

Meanwhile, in the process of coating by circulating the filter material mixture, the air bubble generator (570) is operated to generate an appropriate amount of fine air bubbles so that the settling filter material floats up, thereby allowing the filter material to be evenly coated on the fiber filter (550). At the point when the coating process is finished, the operation of the air supply device (620) and the air bubble generator (570) is stopped, and the filter material mixture is circulated for a certain period of time to finish.

The main filtration step (S30) is a process in which, after the filter coating step (S20) is completed, the primary treated water that has passed through the pretreatment filter (200) is supplied to the main filter (500) and passed through the fiber filter (550) to be filtered. Therefore, in the main filtration step (S30), the primary treated water that has passed through the pretreatment filter (200) is directly fed into the main filter (500) without passing through the filter tank (400).

After the filter material coating step (S20) is completed, the filter material is attached to the fiber filter inside the body (510) of the main filter (500), so the filter material mixing water is filled with primary treatment water with little or no filter material, and thus the normal main filtration process in which the raw water is automatically processed through the pretreatment filter (200) and then passes through the main filter (500) is performed.

At this time, as the primary treated water passes through the inlet (512) and the treated water distributor (560), the water pressure is significantly lowered, so that the primary treated water maintains only a constant pressure without a water flow and passes through the fiber filter (550) to filter out fine foreign substances, and the purified water from which foreign substances are separated through the filtration process is collected on the upper side of the filter combination plate (540) through the inside of the fiber filter (550), and passes through the through hole (522) and the backwash water equalization supply device (530) to exit the body (510) and is discharged into the purified water discharge pipe (640). In the main filtration stage (S30), the valves (622, 632) installed in the filter material mixed water circulation pipe (620) and the backwash water supply pipe (630) are closed, respectively.

Meanwhile, if the main filtration process proceeds for a certain period of time or longer, the amount of foreign substances filtered by the filter medium coated on the fiber filter (550) increases and the filtration performance gradually deteriorates. In this case, the main filtration process is stopped and a reverse washing process is performed.

The detachment step (S40) detaches foreign substances from the fiber filter in a very short time prior to the reverse washing process.

When a foreign substance is attached to the filter medium coated on the fiber filter (550) and the fiber filter is blocked, the spring inside the fiber filter contracts due to the pressure of the pump, causing the pressure to increase and the flow rate to decrease. At this time, when the preset pressure and flow rate values are reached, the operation of the second pump (300) is stopped to stop the operation of supplying the primary treated water to the main filter (500). As the spring that was contracted inside the fiber filter (550) is restored to its original state due to the pressure change, the filter cloth of the fiber filter (550) is shocked, causing the filter medium on the surface attached to the filter cloth together with the foreign substance to be detached for a short time (approximately 1 minute). After the detachment for approximately 1 minute, the drain valve at the bottom of the main filter (500) is immediately opened for a moment to discharge the foreign substance accumulated on the floor through the drain (514).

The reverse osmosis step (S50) is a process performed to initialize the fiber filter (550) of the main filter (500) after going through several removal processes.

In this step, the air bubble generator (570) is first operated at maximum to detach the filter material coated on the fiber filter (550).

Thereafter, for perfect reverse filtration, the primary treated water that has passed through the pretreatment filter (200) is supplied into the body (510) through the reverse filtration process, that is, the reverse wash water supply pipe (630), by using the pressure of the second pump (300). The reverse wash water supplied into the body (510) is evenly supplied to the upper part of the filter combination plate (540) through the reverse wash water equalization supply device (530), flows into the filter cloth of the fiber filter (550), expands the filter cloth, and is discharged to the outside of the filter cloth. At this time, foreign substances and filtering agent attached to the filter cloth are detached, so that the fiber filter (550) is initialized. In this reverse wash process, the valves (612, 622, 642) installed in the main supply pipe (610), the filter material mixed water circulation pipe (620), and the purified water discharge pipe (640) are closed, respectively.

When the reverse filtration step (S50) is completed, it immediately switches to the aforementioned filter coating step (S20) to enable continuous filtration.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments described above. That is, those skilled in the art to which the present invention pertains may make numerous changes and modifications to the present invention without departing from the spirit and scope of the appended claims, and equivalents of all such appropriate changes and modifications should also be considered to fall within the scope of the present invention.

100. 1st pump 200. Pretreatment filter
300. Second pump 400. Filter tank
500. Main filter 510, body
520. Top cover 530. Backwash water equalizer
540. Filter combination plate 550. Fiber filter
560. Treatment water distributor 570. Air bubble generator
610. Main supply pipe 620. Filter media mixed water circulation pipe
630. Backwash water supply pipe 640. Purified water discharge pipe
600. Air supply

Claims (7)

A pretreatment filter having a drum filter structure for primary (pretreatment) filtering of raw water;
A filter tank for producing a filter material mixture by mixing primary treated water that has passed through the above pretreatment filter and powdered filter material; and,
A main filter is provided, which receives filter media mixed water that has passed through the filter media tank through a main supply pipe and coats the filter media on a vertically arranged fiber filter, and after the coating process is completed, filters the primary treated water that has passed through the pretreatment filter through the fiber filter coated with the filter media for a second time;
The above main filter is,
A body having an inlet on one side for introducing the primary treatment water and filter media mixture, and a drain on the bottom;
An upper cover which is joined to the upper part of the above body and has a through hole formed in the central part;
A filter joining plate positioned inside the body to be joined to the body and upper cover, having a plurality of joining holes formed therethrough to allow each of the fiber filters to be joined;
A treated water distributor positioned inside the body so as to be connected to the inlet port and to evenly supply the primary treated water and filtered water mixture into the body;
An air bubble generator, which is arranged on the above-mentioned treatment water distributor and has a spiral tube structure and micro-holes formed at regular intervals, and which ejects air supplied from an air supply device outside the body into the micro-holes to generate air bubbles in the primary treatment water and filter media mixture;
A branch pipe connected to the upper part of the above through hole;
A purified water discharge pipe connected to one side of the above branch pipe and through which purified water that escapes from the body through the above through-hole is discharged;
A backwash water supply pipe connected to the other side of the branch pipe and the main supply pipe to supply the primary treated water supplied from the pretreatment filter as backwash water into the inside of the body through the through hole;
A filter mixture water circulation pipe connected to the above-mentioned water discharge pipe and the above-mentioned filter material tank, which allows the filter mixture water that comes out of the body through the above-mentioned through-hole to flow into the filter material tank and circulate it back into the body; and,
A filtration system characterized by comprising: a backwash water equalization supply device, which is connected to the lower portion of the through hole of the upper cover and includes a central branch pipe for supplying backwash water supplied from the backwash water supply pipe to the central portion of the body and a plurality of outer branch pipes installed at regular intervals for supplying backwash water in the circumferential direction of the inner wall of the body so as to uniformly supply backwash water into the interior of the body.
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