KR101577822B1 - System and Method for Filtering - Google Patents

Abstract

The present invention can select a suction pump that is operated at a speed corresponding to the inflow amount of raw water flowing into the water tank and selectively connect the suction pump to the filtration membrane cassette so as to quickly cope with changes in the inflow amount of raw water, The present invention relates to a filtration system and a filtration system that can significantly reduce costs, and a filtration system of the present invention includes a water bath; A first filtration film cassette immersed in feed water in the water tank; A first pump for providing a first negative pressure to the first filter film cassette; A first valve for on / off connection between the first filter film cassette and the first pump; And a second pump for providing a second negative pressure to the first filter film cassette.

Filtration membrane, cassette, water tank

Description

≪ Desc / Clms Page number 1 > System and Method for Filtering &

More particularly, the present invention relates to a filtration system and a method thereof, and more particularly, to a filtration system and a filtration method thereof, The present invention relates to a filtration system and a method thereof capable of rapidly responding to a change in an inflow amount and drastically reducing the maintenance / repair cost of the facility.

Compared with the separation method using heating or phase change, the separation method using the filter membrane has many advantages. One of them is that a desired quality of water can be stably obtained by using a filtration membrane having an appropriate pore size, thereby improving the reliability of the process. Further, since the filtration membrane does not require any operation such as heating, it can be used in a separation process using a microorganism that can be influenced by heating or the like.

One of the separation methods using a filtration membrane is a method using a hollow fiber membrane module including a hollow fiber membrane bundle and a method using a flat membrane module. Traditionally, filtration membrane modules have been widely used in the field of microfiltration such as aseptic water, drinking water, and ultrapure water. In recent years, filtration membrane modules have been used for sewage treatment, solid-liquid separation in septic tanks, removal of suspended solid (SS) Filtration of industrial water, and filtration of water storage materials.

One of such filtration membrane modules is a submerged membrane membrane membrane membrane membrane membrane membrane membrane module which immerses a filtration membrane module directly in a tank of a fluid to be treated and separates solid components such as impurities or sludge by selectively applying a negative pressure to the inside of the filtration membrane, There is a filter membrane module. The submersible filter membrane module is mainly used as a cassette unit in which a plurality of modules are mounted on a frame.

More specifically, as shown in FIG. 1, raw water is supplied to the water tank 10 from a raw water tank 20 storing raw water to be processed. A plurality of filter film cassettes 11 are immersed in a water bath 10. When a constant negative pressure is applied to the plurality of filter film cassettes 11 by the suction pump 30, only the fluid excluding the solid component selectively passes through the filter film in the filter film cassettes 11. The fluid (hereinafter referred to as "filtered water") that has passed through the filtration membrane is sent to a filtrate tank (not shown).

On the other hand, another concentrating device 40 for recovering the water not collected by the filter film cassettes 11 in the water tank 10 is additionally provided. Since the concentrating device 40 mainly uses a rough filtration method such as a fabric filter or a sandblast method, the recovered water is used in the same manner as the filtered water obtained by the filter film cassettes 11 Can not handle. Thus, the water additionally obtained from the concentration apparatus 40 is supplied to the raw water tank 20.

An inverter 50 is connected to the suction pump 30 for providing negative pressure to the plurality of filter film cassettes 11. The inverter 50 adjusts the operation speed of the suction pump 30 according to the inflow amount of the raw water flowing into the water tank 10 so that filtered water is produced at a predetermined flux. That is, the flow rate of the filtered water produced by controlling the size of the negative pressure supplied from the suction pump 30 to the filter film cassettes 11 by the operation of the inverter 50 can be maintained.

However, in the case of the filtration system shown in FIG. 1, since the inverter 50 must be additionally installed, it is not only costly but also increases the durability of the suction pump 30 due to frequent shifting depending on the inflow amount of the raw water. There is a problem of deterioration. In addition, there is a disadvantage that the response speed to the change of the inflow amount of the raw water is slow.

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a filtration system and method that can avoid problems due to limitations and disadvantages of the related art.

The advantage of the present invention is that the suction pump, which is operated at a speed corresponding to the inflow amount of the raw water flowing into the water tank, is selected and selectively connected to the filter film cassette, And a filtration system and method which can remarkably reduce maintenance costs.

Further features and advantages of the invention will be described hereinafter, and will in part be obvious from the description. Alternatively, other features and advantages of the invention may be learned through practice of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The objects and other advantages of the present invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purpose of the present invention, a water bath; A first filtration film cassette immersed in feed water in the water tank;

A first pump for providing a first negative pressure to the first filter film cassette; A first valve for on / off connection between the first filter film cassette and the first pump; And a second pump for providing a second negative pressure to the first filter film cassette.

According to another aspect of the present invention, there is provided a method of controlling a water pump, comprising: selecting a first one of a plurality of pumps providing different sound pressures based on an inflow amount of raw water flowing into a water tank; Turning on the connection between the selected first pump and the first filtration membrane cassette immersed in raw water in the water tank; And turning off the connection state of the pump (s) except the first pump and the first filter cassette among the plurality of pumps.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the invention as claimed.

According to the filtration system and method of the present invention, an inverter for controlling the operation speed of the suction pump is not required, so that the initial installation cost of the filtration system can be reduced.

Further, from the viewpoint of the suction pump, since each suction pump is operated at a constant speed, the durability can be maintained for a long time, and the maintenance cost of the filtration system can be reduced as a result.

In addition, according to the filtration system and method of the present invention, it is possible to quickly cope with a change in the inflow amount of the raw water flowing into the water tank by appropriately selecting the sound pressure to be provided to each filter film cassette by simple valve operation.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Therefore, the present invention encompasses all changes and modifications that come within the scope of the invention as defined in the appended claims and equivalents thereof.

As used herein, the term 'filtration membrane' includes both immersion type membranes such as a flat sheet membrane and a hollow fiber membrane.

As used herein, the term 'filter cassette' refers to a unit structure in which one or more filtration membrane modules are mounted in one frame.

The term " impurity " as used herein includes all solid components contained in water.

As used herein, the term " concentration of impurities " refers to the concentration of impurities measured when the water treatment process reaches an equilibrium state, and is measured at least 24 hours after the start of the water treatment operation.

Hereinafter, one embodiment of the filtration system and method of the present invention will be described in detail with reference to the accompanying drawings.

2 is a schematic view of a filtration system according to a first embodiment of the present invention.

A plurality of filter film cassettes 110 are immersed in raw water in a water bath 100. The first pump 210 provides a first negative pressure to the filter cassettes 110 and the second pump 220 provides a second negative pressure to the filter film cassettes 110. The first and second negative pressures are different in size, for example, the first negative pressure is larger than the second negative pressure.

The connection between the first pump 210 and the filter film cassettes 110 is turned on and off through the first valve 310 and the connection between the second pump 220 and the filter film cassettes 110 The connection is turned on / off via the second valve 320. In this specification, the connection between the pump and the filter film cassette is turned on / off means that the pipe connecting the pump and the filter film cassette is opened and closed.

In the case of the filtration system according to the first embodiment of the present invention, first and second pumps 210 and 220 are connected in parallel to a pipe for delivering filtered water produced in each filter cassette 110. In this case, since the first and second pumps 210 and 220 are connected in parallel to the respective filter film cassettes 110, as compared with the case where these pumps are connected in series to the filter film cassettes 110, There is an additional benefit of lower installation costs.

Operation of the filtration system according to the first embodiment of the present invention shown in FIG. 2 will be described below.

First, an inflow amount of raw water flowing into the water tub 100 is sensed, and one of the first and second pumps 210 and 220 is selected based on the inflow amount. In the case where the inflow amount of the raw water is relatively large, the first pump 210 that provides a relatively larger first negative pressure is selected to increase the filtration rate, and when the inflow amount of the raw water is relatively small, A second pump 220 providing a negative pressure will be selected.

For example, assuming that the first pump 210 is selected, the first valve 310 is operated to turn on the connection state of the first pump 210 and the filter film cassettes 110. At the same time, the second valve 320 is operated to turn off the connection between the second pump 220 and the filter film cassettes 110.

Alternatively, when the inflow amount of the raw water flowing into the water tub 100 is very large, the first and second pumps 210 and 220 are simultaneously used to produce filtered water from the filter membrane cassettes 110, The first and second valves 310 and 320 can be controlled so that the connection state is all on.

A third pump for providing a third negative pressure different in magnitude from the first and second negative pressure and a third valve for on / off connection between the third pump and the filter cassettes 110 are connected to the filtration system . ≪ / RTI >

3 is a schematic view of a filtration system according to a second embodiment of the present invention.

As shown in FIG. 3, the filtration system according to the second embodiment of the present invention includes a water tank 100. The water tank 100 has an inlet 101 into which raw water to be treated is drawn and an outlet 102 through which concentrated raw water is discharged after processing.

A plurality of filter film cassettes 111 to 117 are immersed in the raw water in the water tank 100. The plurality of filter film cassettes 111 to 117 are arranged in a line from the inlet 101 side to the outlet 102 side. In addition, the plurality of filter film cassettes 111 to 117 are densely packed in the water tub 100. Therefore, the water flowing into the water tub 100 can not be uniformly dispersed in the respective filter film cassettes 111 to 117, but sequentially passes through the filter film cassettes 111 to 117 arranged in a row.

The raw water introduced through the inlet 101 is first processed by the filter cassette 111 located closest to the inlet 101 and the raw water which has been first treated is then transferred to the filter cassette 112 Moved and processed in a second order. The second treated raw water is finally treated by the filtration film cassettes 117 to be positioned closest to the discharge port 102 after being processed continuously through the filter film cassettes 113 to 116 in turn. Therefore, in the filtration system of the present invention, when the water treatment process is in an equilibrium state, a gradient of the impurity concentration depending on the position in the raw water in the water tank 100 is generated. As a result, The impurity concentration of the raw water treated by the filter cassette 111 located close to the filter medium cassette 117 located nearest to the discharge port 102 is smaller than the impurity concentration of the raw water to be treated.

As described above, in the filtration system according to the second embodiment of the present invention, since the impurity concentrations of the raw water to be treated by the filtration membrane cassettes 111 to 117 are different from each other, the same sound pressure is applied to each of the filtration membrane cassettes 111 to 117 The degree of fouling of the multi-faced filtration membrane will be different for each of the cassettes 111 to 117. That is, the fouling of the most severe filtration membrane will appear in the filtration membrane cassette 117 that needs to treat the raw water having the highest impurity concentration (the most concentrated), and if it is severe, breakage of the filtration membrane may occur. Therefore, it is necessary to minimize the fouling of the filtration membrane and thereby the membrane damage by applying a lower sound pressure to the filtration membrane cassette 117 on the discharge port 102 side where the raw water having the highest impurity concentration (most concentrated) has to be treated .

According to the second embodiment of the present invention, a filtration system is provided in which a suction pump, which provides different sound pressures depending on the positions of the filter film cassettes 111 to 117, can be connected. As shown in FIG. 3, a plurality of filter film cassettes 111 to 117 are immersed in raw water in the water tank 100. The first pump 210 provides a first negative pressure to the filter cassettes 110 and the second pump 220 provides a second negative pressure to the filter film cassettes 110. The first and second negative pressures are different in size, for example, the first negative pressure is larger than the second negative pressure.

The connection between the first pump 210 and the filter film cassettes 111 to 117 is turned on and off through the first valves 311 to 317 respectively and the second pump 220 and the filter film cassettes The connection between the first and second valves 111 to 117 is turned on / off via the second valves 321 to 321, respectively. That is, each of the filter cassettes 111 to 117 may be selectively connected to any one of the first pump 210 and the second pump 220 independently of each other.

Thus, according to the second embodiment of the present invention, when it is necessary to increase the filtration speed due to the relatively large amount of the raw water flowing into the water tub 100, the first valves 311 to 316 are adjusted to the water tub The connection between the first filter 210 and the filtration cassettes 111 to 116 positioned at the front part of the first pump 100 is turned on and the second valve 327 is adjusted to the back part The connection state between the filter film cassette 117 and the second pump 220 can be turned on. At the same time, the second valves 321 to 326 are adjusted to turn off the connection state between the filter cassettes 111 to 116 located at the front end and the second pump 220, and the first valve 317 is controlled Thereby turning off the connection state between the filtration membrane cassette 117 located at the downstream end and the first pump 210. [

4 schematically shows a filtration system according to a third embodiment of the present invention.

As shown in FIG. 4, the filtration system according to the third embodiment of the present invention has a configuration in which a third pump 230 is further added to the filtration system according to the second embodiment. The third pump 230 is provided to provide the filter membranes 111 to 1117 with third negative pressure different from the first and second negative pressure provided by the first and second pumps 210 and 220 . Third valves 331 to 337 for turning on / off the connection between the third pump 230 and the filter film cassettes 111 to 117 are provided.

According to the third embodiment of the present invention, by the operation of the first to third valves 311 to 317, 321 to 327, and 331 to 337, the filter film cassettes 111 to 117 are independently 3 pumps 210, 220, and 230, respectively.

Also in the second and third embodiments of the present invention, as in the first embodiment of the present invention, a plurality of pumps are connected in parallel to the respective filter film cassettes, thereby reducing the installation cost of the piping. It is of course also possible to simultaneously control the connection between the pumps and the filter cassette by controlling each of the valves so that a plurality of pumps can simultaneously contribute to the production of filtered water through the filter cassette.

5 is a block diagram schematically illustrating a control system according to an embodiment of the present invention.

5, the filtration system according to an embodiment of the present invention includes a control unit 500 for controlling the entire operation of the system, and a raw water inflow amount sensing unit for sensing inflow amount of raw water flowing into the water tub 100 400). The raw water inflow amount sensing unit 400 transmits the inflow amount data to the control unit 500. The control unit 500 controls valves for turning on / off the connection state between the filter film cassettes and the suction pumps based on the inflow amount data. The controller 500 may control the operation of each of the suction pumps.

The filtration system according to an embodiment of the present invention may further include a membrane contamination detecting unit 600 for detecting the degree of contamination of the filtration membrane and transmitting the contamination data to the controller 500. The degree of contamination of the filtration membrane can be determined, for example, by measuring Trans Membrane Pressure (TMP). The control unit 500 controls a blower 700 that provides air for the periodic cleaning on the basis of the contamination data transmitted from the membrane fouling sensing unit 600.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

Figure 1 is a schematic representation of a general filtration system,

2 to 4 are schematic views of a filtration system according to the first to third embodiments of the present invention,

5 is a block diagram schematically illustrating a control system according to an embodiment of the present invention.

DESCRIPTION OF REFERENCE NUMERALS

100: Water tank 110 to 117: Filter membrane cassette

210, 220, and 230: first to third pumps

310 to 317: first valve 320 to 327: second valve

331 to 337: Third valve

400: raw water inflow amount sensing unit

500:

600: membrane fouling detection unit

700: blower

Claims (12)

Water bath; First and second filter film cassettes immersed in feed water in the water tank; A first pump for providing a first negative pressure to the first and second filter film cassettes; First valves for on / off the connection between the first and second filter cassettes and the first pump, respectively; A second pump for providing a second negative pressure to the first and second filter cassettes; And And second valves for turning on and off the connection between the first and second filter cassettes and the second pump, respectively. delete delete The method according to claim 1, A third pump for providing a third negative pressure to the first and second filter film cassettes; And Further comprising third valves for on / off connection between the first and second filter cassettes and the third pump, respectively. 5. The method of claim 4, Wherein the third sound pressure is different from the first sound pressure and the second sound pressure. The method according to claim 1, Further comprising a control unit for controlling the first and second valves to provide either or both of the first and second negative pressure to the first filter film cassette based on an inflow amount of raw water flowing into the water tank And the filtration system. The method according to claim 6, Further comprising a raw water inflow amount sensing unit for sensing an inflow amount of the raw water flowing into the water tank and transmitting the inflow amount data to the control unit, Wherein the controller controls the first and second valves based on the inflow data received from the raw water inflow detecting unit. The method according to claim 1, Wherein the first and second negative pressure are of different sizes. The method according to claim 1, Wherein the first and second pumps are connected in parallel to the first filter cassette. Selecting a first one of the plurality of pumps providing different sound pressures based on the inflow amount of the raw water flowing into the water tank; Turning on the connection between the selected first pump and the first filtration membrane cassette immersed in raw water in the water tank; Turning off the connection state of the pump (s) except for the first pump and the first filtration film cassette among the plurality of pumps; Further selecting a second one of the plurality of pumps; Turning on a connection state of the second pump and a second filtration film cassette immersed in raw water in the water tank; And And turning off the connection state of the pump (s) except for the second pump and the second filtration film cassette among the plurality of pumps. 11. The method of claim 10, And detecting an inflow amount of the raw water flowing into the water tank. delete

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