KR101739439B1

KR101739439B1 - Small Membrane Filtration System

Info

Publication number: KR101739439B1
Application number: KR1020150103132A
Authority: KR
Inventors: 손동민; 이상훈
Original assignee: 주식회사 크로시스엔텍
Priority date: 2015-07-21
Filing date: 2015-07-21
Publication date: 2017-05-26
Also published as: KR20170011127A

Abstract

The present invention relates to a small membrane filtration system, wherein a small membrane filtration system according to the present invention uses a non-mixed space occupying vessel between raw water and membrane filtration produced water (reverse water wash) Supply and backwash. The small membrane filtration system according to the present invention can be operated with natural energy such as sunlight or wind power, and is also suitable for use in a book area or a developing country.

Description

{Small Membrane Filtration System}

The present invention relates to a small membrane filtration system, and more particularly, to a small membrane filtration system capable of performing raw water supply and backwashing using only a raw water supply pump without a backwash pump.

The general water treatment process consists of flocculation, floc formation, sedimentation, filtration and disinfection by removing particulates through physical and chemical mechanisms by drug aggregation. This conventional water treatment method is capable of stable water treatment, but it does not remove all pathogenic microorganisms. Especially, it is difficult to remove pathogenic microorganisms such as cryptosporidium.

In recent years, water quality standards including disinfection byproducts have been strengthened. In order to meet these water quality standards, membrane filtration water treatment process is being studied as a new alternative technology in the water industry.

Advantages of this membrane filtration process include less use of chemicals, a smaller footprint, and automation. In addition, it can be combined with various water treatment processes, and sludge, which is a byproduct of treatment, is generated less.

In the case of micro filtration and ultrafiltration during the membrane filtration process, since there are many manufacturers of related membrane modules, they are not only stable in price but also do not require a lot of driving energy. Therefore, It is suitable for the filtration system as the energy source.

Filtration systems with solar or wind power as the primary energy source are suitable for the construction of small portable equipment because of the low energy consumption and these compact systems are difficult to install large scale water treatment plants, It is particularly economical and effective in remote areas such as the island or in developing countries where transportation is difficult.

FIG. 1 shows a conventional membrane filtration system.

The membrane filtration module 100 includes a feed water inlet port 100a, a production water outlet port 100b, a drain port 100c, and a concentrated water outlet port 100d. The feed water (raw water) A feed water line 102 for connecting the membrane filtration module 100 to the feed water tank 101, a raw water feed pump 103, a feed water line valve 104, a feed water flow meter 105 and a feed water pressure gauge 106.

The production water line passing through the membrane filtration includes a reverse water tank 110 for storing production water, a production water line 111 for connecting the reverse water tank 110 to the production water outlet port 100b of the membrane filtration module, a production water line valve 112, a production water flow meter 113 A production water pressure meter 114, and a drinking water line 115 connected to the reverse osmosis water tank 110 to supply drinking water when necessary.

The reverse water line 120 is connected to the production water line 111 and is located in front of the production water line valve 112. The backwash side is composed of a backwash pump 121, a medicine tank 122, a medicine infusion pump 123, a medicine infusion control valve 124, a reverse osmosis line valve 125, an air infusion line 126, an air compressor 127 and an air infusion line valve 128.

The drain line 131 connected to the drain port 100c of the membrane filtration module 100, the drain valve 132, the concentrated water line 133 connected to the concentrated water outlet port 100d, the concentrated water line valve 134, the concentrated water drain line 135 bypassing the concentrated water line 133 A concentrated water drain valve 136, and a concentrated water drain line 135. The wastewater tank 130 collects wastewater discharged through the concentrated water drain line 136,

Low-pressure membrane filtration processes, such as microfiltration and ultrafiltration, are considered to be techniques specific to turbidity-inducing substances (turbid). The particle size of the tablet to be treated varies slightly from manufacturer to manufacturer, but is usually known to be more than 0.05 μm. Therefore, when raw water having high turbidity is treated, it may cause a rapid fouling of the membrane filtration. Therefore, it is necessary to provide a pretreatment device capable of removing coarse contaminants before the membrane filtration process depending on the characteristics of the source.

A media filter, a screen filter, a disk filter, and the like are widely used as the preprocessing device, and are not directly related to the present invention, and a detailed description thereof will be omitted.

The raw water to be treated by the membrane filtration can be primarily stored in the feed water tank and supplied to the membrane filtration module, but the tank can be omitted if access to the lake water or surface water is easy. However, a large membrane filtration system is generally provided with a feed water tank (or reservoir) to protect the pump.

The operation state of the membrane filtration process is largely classified into a normal operation, a backwash operation, and a drain.

The raw water flows into the supply water inlet port 100a of the membrane filtration module 100 through the raw water supply pump 103, at which time the supply water line valve 104 is opened and the flow rate and pressure of the supply water are measured by the flow meter 105 and the pressure gauge 106, respectively.

Since the constant pressure (not more than 3 bar) of the raw water supply pump 103 is higher than the pressure generated in the production water line 111 of the membrane filtration module 100, the fluid is supplied to the membrane at a low pressure portion &Lt; / RTI >

The transferred fluid is referred to as separate filtrate production (Product or Permeate), which is transferred to the retro-seawater tank 110 through the production water line 111. At this time, the flow rate and pressure of the produced water are measured by the flow meter 113 and the pressure gauge 114, respectively, and such a process is called normal operation.

Particles having a size larger than that of the membrane as the particulate contaminant contained in the raw water supplied to the membrane filtration module 100 are fouled by closing the air gap formed on the membrane or accumulating on the surface, Which causes the pressure difference between the pressure and the production water to increase.

As the inter-membrane pressure difference increases, the flow rate of the product water decreases and backwashing is required to restore the air gap of the closed membrane.

The backwash process is a process to remove membrane contaminants that have been closed through the filtration process with reverse water after applying pressure water from the inside of the filtration membrane, contrary to the filtration process, after completion of the filtration process (normal operation).

The quality of the fluid used in backwashing is generally clean to prevent internal contamination of the membrane, so membrane filtration production water is generally used.

The time of backwashing can be set by observing the flow rate of the production water or by using intermembrane pressure difference. The duration of the backwash process is set to 15 to 60 seconds and is greatly influenced by the specifications of the membrane filtration module and the operating conditions at the site.

The backwash operation is performed in the following order.

The supply of the raw water supply pump 103 is stopped and the supply water line valve 104 and the production water line valve 112 opened in the normal operation are closed and the air injection line valve 128, the reverse water line valve 125 and the concentrated water drain valve 136 are opened.

The backwash pump 121 is operated, the backwashing proceeds together with the air cleaning, and the compressed air injected by the air compressor 127 serves to remove contaminants adhering to the surface of the filtration membrane. The air cleaning may be carried out simultaneously with the backwash process and may be omitted or the duration may be shorter than the backwash duration.

The backwash water used in the backwash is discharged to the waste water tank 130 through the concentrated water drain line 135. The air infusion line valve 128, the reverse water line 120, and the concentrated water drain valve 136, which were opened during backwashing, are closed and the drain valve 132 attached to the drain line 131 is opened to discharge the contaminated water existing in the membrane filtration module 100 So that all the contaminated water in the membrane filtration module 100 is discharged to the waste water tank 130.

After the drain is completed, the drain valve 132 is closed for normal operation and the raw water supply line valve 104 and the production water line valve 112 are opened, and then the raw water supply pump 103 is operated and normal operation, backwash operation and drain are repeated according to the schedule .

If the degree of contamination of the membrane is difficult to recover by general physical backwashing, the membrane can be cleaned using chemicals and operated using the chemical tank 122, the chemical injection pump 123 and the chemical control valve 124 during backwash operation.

Chemical cleansing is required if the pores of the membrane are closed by metals such as iron, or if the membrane surface is contaminated by microbial activity.

The operation of the conventional membrane filtration process is as described above. By adopting a generator or a solar energy as a power source for the membrane filtration process, it is desired to reduce the accommodation space of the process, The conventional membrane filtration process has a problem in that it is highly limited in terms of space and resources in accommodating all equipment used in its own process.

In order to solve these spatial problems, it is necessary to simplify the components especially for the backwash. However, the conventional membrane filtration process requires a backwash tank because the membrane filtration production water is used as reverse water wash water, and since the backwash pump can not be mixed with other pumps, it is necessary to separate the raw water supply pump and backwash pump Considering piping and fittings accordingly, these backwash tanks and backwash pumps constitute a compact microfiltration device.

In order to solve such a problem, some overseas companies are performing backwash by applying a sealed expansion tank. FIGS. 2 and 3 are conceptual diagrams of a conventional expansion membrane of a membrane filtration system.

In the closed expansion tank 400 of the conventional membrane filtration system, as shown in FIG. 2, the expansion water 402 is replaced with membrane filtration production water to backwash, and the air cushion 403 sags downward when the production water flows in. As shown in FIG. 3, when the backwash is started, air such as compressed air or nitrogen having pressure is injected into the air cushion 403, so that the air cushion 403 expands rapidly and the produced water present in the closed expansion tank moves backward do.

The backwashing method of this concept is capable of easily discharging foreign substances in the filtration membrane pores at a high flow rate in a short time and has an advantage of increasing the production amount of production time to time due to a short backwash time.

FIG. 4 shows General Electric's ultrafiltration membrane to which this concept is applied. The closed expansion tank 400 is disposed at the lower part of the membrane filtration module and is arranged in a space-intensive manner.

However, this method complicates the structure of the membrane filtration module and makes it difficult to apply existing low-cost commercial components as it is, and additionally requires facilities such as a compressor or a nitrogen tank to supply compressed air or compressed nitrogen.
BACKGROUND OF THE INVENTION [0002] The art of the present invention is disclosed in Japanese Patent Application Laid-Open No. 2000-210543 (Aug. 2, 2000).

It is an object of the present invention to provide a membrane filtration system capable of supplying raw water and backwashing with only a raw water supply pump without a conventional backwash pump and an air compressor, Which can be operated with natural energy such as sunlight or wind power, and which is suitable for use in a remote area such as a book area or a developing country.

Another object of the present invention is to provide a small-sized membrane filtration system that not only reduces the frequency of faults by simplifying components and simplifying operations, but also facilitates maintenance such as replacement of components even in a harsh environment where a small-sized filtration membrane facility is to be used.

In order to achieve the above object, the present invention provides a membrane filtration system configured to perform the supply and backwash of raw water only with a raw water supply pump without a backwash pump in the membrane filtration system.

The present invention also provides a small-sized membrane filtration system configured to be able to supply raw water and backwash with only a raw water supply pump without a backwash pump by using a non-mixed space occupying vessel between raw water and membrane filtration production water (reverse water wash) .

Here, the inter-fluid non-mixed space occupying vessel is composed of a space occupied vessel # 1 and a space occupied vessel # 2 in a symmetrical structure.

In addition, the inter-fluid mixed space occupying vessel is provided with a fluid inlet and an outlet at the upper and lower sides thereof, respectively, and mixing the raw water with the fluid of the membrane filtration produced water (reverse septic water) is prevented inside the membrane filtration module And a fluid mixing prevention bag for pushing out the reverse water.

Wherein the fluid mixing prevention cloth is fixed to a point where the space occupied vessel No. 1 and the space occupied vessel No. 2 are coupled symmetrically in the upper and lower sides within the fluid non-mixed space occupying vessel, Type fluid-mixing-resistant foam in which the inflow fluid occupies all the spaces in the non-mixed space occupying vessel by flowing the fluid into one of the fluid inlet and outlet of the container and filling the fluid-mixing preventing cloth.

Wherein the fluid mixing prevention cloth is fixed to either one of the space occupied vessel 1 and the space occupied vessel 2 at one of the fluid inlet and outlet of the non-mixed space occupying vessel, Type fluid-mixing-resistant foam in which the inflow fluid is occupied in all the spaces in the non-mixed space occupying vessel by flowing the fluid into one fluid inlet and filling the fluid-mixing-preventing can.

In addition, in the non-mixed space occupying vessel, the fluid mixing preventing cap is separated from the upper and lower fluid access openings of the non-mixed space occupying vessel to form upper and lower fluid access openings of the non- The fluid mixing prevention bouncing prevention plate is further provided at the upper and lower fluid inlet and outlet of the non-mixed space occupying vessel.

The small membrane filtration system according to the present invention can be operated with natural energy such as sunlight or wind power by making the system compact so that raw water can be supplied and backwashed by only the raw water supply pump without the conventional backwash pump and air compressor And is suitable for use in a book area or a developing country.

In addition, the small membrane filtration system according to the present invention has a simple effect that the component parts are simplified, the operation is simple, the frequency of failure is small, and maintenance and repair such as replacement of parts are easy even in a harsh environment where a small filtration membrane facility is used.

1 is a conceptual diagram of a conventional membrane filtration system.
FIGS. 2 and 3 are conceptual views of a conventional membrane filtration system for a closed tank.
4 is a conceptual diagram of an ultrafiltration membrane system of General Electric Company having a conventional sealed tank.
FIG. 5 is a view for explaining an inter-fluid non-mixed space occupying vessel of a small-sized membrane filtration system according to an embodiment of the present invention.
6 is a view for explaining a fluid mixing prevention cloth of an inter-fluid non-mixed space occupied vessel according to an embodiment of the present invention.
FIG. 7 is a diagram of a fluid flow diagram during normal operation of a small membrane filtration system in accordance with an embodiment of the present invention. FIG.
FIG. 8 is a flow chart of the backwash operation of the small membrane filtration system according to one embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may obscure the subject matter of the present invention.

FIG. 5 is a perspective view, (b) side view, and (c) cross-sectional view for explaining a non-intermix space confinement vessel of a small membrane filtration system according to an embodiment of the present invention.

In FIG. 5, the space-occupied vessel 301 of the non-mixed space occupied vessel 300 is completely and vertically symmetrical with the vessel 302 of the space occupied space 302, which reduces the production cost and facilitates easy maintenance .

The space occupied vessel No. 1 and the space occupied vessel No. 2 respectively have fluid outlets 303 and 304. Reference numerals 305 and 306 in the sectional view (c) denote the mixing of raw water and membrane filtration produced water (Not shown) to the fluid outlets 303 and 304 to prevent the respective fluid outlets from being closed.

As can be seen from the sectional view (c), when the space occupied container No. 1 and the space occupied container No. 2 are combined, the interior forms an elliptical space. The shape of the space varies depending on the type of the fluid mixture- .

6 is a view for explaining a fluid mixing prevention cloth of a non-intermixed space occupying vessel according to an embodiment of the present invention, wherein the diaphragm type fluid mixing prevention cloth 307 of FIG. 6A includes two space occupying receptacles 301, 302, and the fluid is introduced into one of the fluid outlets of the non-mixed space holding vessel 300 to be filled in the fluid mixing preventing vial 307, 300 has a mechanism in which the inflow fluid occupies all the space within the chamber.

In addition, the balloon-type fluid mixing prevention bubble 308 of (b) is fixed to the fluid entrance of one of the two space occupied containers 301 and 302, and is also connected to one of the fluid entrances The fluid is introduced into the fluid mixing prevention vial 308 and filled in the fluid mixing prevention vial 308, so that the inflow fluid occupies all the spaces in the non-mixing space occupying vessel 300.

As described in FIG. 7, the two fluids to be used are raw water (feed water) to be subjected to membrane filtration and membrane filtration production water to be used as counter-wash water.

Figures 7 and 8 are fluid flow diagrams of a mini membrane filtration system in accordance with an embodiment of the present invention. Like the conventional membrane filtration system, the small membrane filtration system according to an embodiment of the present invention can be divided into a normal operation and a backwash operation.

FIG. 7 shows the flow of the fluid during normal operation of the small membrane filtration system according to an embodiment of the present invention. The normal operation is a series of processes in which the raw water introduced through the raw water supply pump 103 moves through the filtration membrane module 100. The 3-way valve 104 '(the pump discharge portion and the filtration membrane module inflow side portion) The production water line valve 112 of the water line 111 is opened, and the operation of the raw water supply pump 103 is started after the concentrated water drain valve 136 and the drain valve 132 are closed.

The fluid introduced through the raw water supply pump 103 flows into the filtration membrane module 100 through the supply water line 102 and the supply water (raw water) flowing into the filtration membrane module 100 is supplied to the filtration membrane .

The filtered water passes through the production water line 111, where a portion of the filtered water

Mixed-space holding vessel 200 through the back-flow-side flow passage 201 of the non-mixed-space holding vessel 200.

The fluid mixing prevention cloth 204 for separating the reverse water wash chamber 202 and the raw water chamber 203 of the fluid non-mixed space holding vessel 200 by the inflow filtered water is brought into close contact with the lower end portion of the raw water chamber 203.

The raw water remaining in the raw water chamber 203 flows out to the wastewater tank 130 mostly in the drain stage before the normal operation but in the normal operation stage the raw water side drain valve 206 of the non-mixed space holding vessel 200 is always open, All of the raw water is discharged.

When the filtered water in the fluid non-mixed space occupying vessel 200 is completely filled, the filtered water naturally flows out through the open production water line valve 112 to the product quantity.

If the contaminants contaminate the surface and voids of the filtration membrane as the normal operation progresses, a difference between the pressures of the feed water pressure gauge 106 and the production water pressure gauge 114 begins to increase. This differential pressure increases as the filtration membrane becomes contaminated, and when the filtration membrane manufacturer reaches a specified differential pressure, backwash operation is started to recover this pressure difference.

A fluid flow chart of the backwash operation is shown in Fig.

The production water line valve 112 that was opened during normal operation and the raw water side drain valve 206 of the non-mixed space occupied vessel are closed.

When the backwash water is supplied to the inside of the membrane filtration module 100, the backwash water used for washing is discharged to the outside of the membrane filtration module 100 together with the raw water existing inside the existing membrane filtration module 100 (outside the membrane where the raw water of the filtration membrane is in contact) The concentrated water drain valve 136 to be discharged is opened.

The supply water line 3-way valve 104 'is closed in the direction of connection to the membrane filtration module 100 and the raw water supply pump 103 and the raw water side flow path of the non-fluid mixing space occupying vessel 200 are opened.

The valves are simultaneously opened and closed, and the raw water supplied from the raw water supply pump 103 is changed to flow into the raw water chamber 203 of the non-mixed space holding vessel 200. The introduced raw water has the same pressure as that of the raw water supply pump 103,

As the concentrated water drain valve 136 is opened, the backwash-side flow path is lowered to about atmospheric pressure, so that the fluid-mixing preventing vat 204 is pushed toward the reverse osmosis chamber 202 of the non-mixed space occupied vessel and occupies the volume in the non- .

As the time passes, the fluid mixing prevention cloth 204 is completely brought into close contact with the upper part of the reverse osmosis chamber 202 of the fluid non-mixing space occupying vessel 200, and the membrane filtration water (backwash water) remaining in the reverse osmosis chamber 202 is completely filtered The inside of the module (the production water of the filtration membrane is pushed into the contacted membrane). At this time, the pressure loss due to the fluid movement is ignored so that the filtered water has a pressure substantially equal to the discharge pressure of the raw water supply pump 103.

The backwash ends when the filtered water in the fluid non-mixed space occupying vessel 200 is completely exhausted. The end point of the backwash is a logic operation control device (PLC, Programmable) based on the flow rate of the raw water supply pump 103 and the volume of the non- (Not shown) in the flow meter 113 or the fluid non-mixed space occupied vessel 200, or the like.

After the backwashing is completed, the raw water supply pump 103 is temporarily stopped to discharge the contaminated water existing in the membrane filtration module 100 (raw water contact portion), and the drain valve 132 is opened to discharge all the contaminated water remaining in the module. Thereafter, the normal operation is restarted.

The filtration membrane can cause irreparable contamination only by the physical backwash described above. In this case, it is necessary to clean the filtration membrane using the chemical agent.

However, if a drug storage container for drug injection and a drug injection pump are installed on the membrane filtration system, it is difficult to simplify the system. Therefore, in one embodiment of the present invention, a portable drug injection kit is connected to the system, A chemical injection valve 210 is provided in the system.

It should be understood that the scope of protection of the present invention is not limited to the description and the expression of the embodiments explicitly described above, and the scope of protection of the present invention can not be limited by obvious alterations or permutations of the present invention.

100: membrane filtration module
100a: supply water inlet port 100b: production water outlet port
100c: drain port 100d: concentrated water outlet port
101: feed water tank 102: feed water line 103: raw water feed pump
104: feed water line valve 104 ': feed water line 3-way valve
105: Feed water flow meter 106: Feed water pressure gauge
110: Reverse osmosis water tank
111: Produced water line 112: Produced water line valve 113: Produced water flow meter
114: Production water pressure gauge 115: Drinking water line
120: Reverse water line
121: backwash pump 122: drug tank 123: drug injection pump
124: chemical control valve 125: reverse water line valve 126: air injection line
127: air compressor 128: air injection line valve
130: waste water tank
131: drain line 132: drain valve 133: concentrated water line
134: concentrated water line valve 135: concentrated water drain line
136: Condensate drain valve
200: Fluid non-mixed space occupied vessel
201: Reverse flow side passage of the non-fluid mixing space occupied vessel
202: reverse osmosis chamber of the fluid non-mixed space occupied vessel
203: raw fluid chamber of the fluid non-mixed space occupied vessel
204: fluid mixing prevention cloth
205: The raw water side flow path of the non-fluid mixing space occupying vessel
206: The raw water side drain valve of the fluid non-mixed space occupied vessel
210: drug injection valve
300: fluid non-mixed space occupied vessel
301: space occupation number 1 container 302: space occupation number 2 container
303: Fluid outlet of container 1 304: Fluid outlet of container 2
305: Fluid mixing prevention bounce prevention plate
306: Fluid mixing prevention bounce prevention plate in container 2
307: diaphragm type fluid mixing prevention cloth
308: Balloon type fluid mixing prevention cloth
400: Enclosed expansion tank
401: Diaphragm 402: Expansion water 403: Air cushion

Claims

A small membrane filtration system capable of supplying raw water and backwashing with only a raw water supply pump without a backwash pump,
Wherein the raw water and backwash water are supplied to the raw water and membrane filtration production water using only the raw water supply pump without the backwash pump by using the non-mixed space occupying vessel of the fluid.

delete

The method according to claim 1,
Wherein the inter-fluid non-mixed space occupying vessel is composed of a space occupied vessel No. 1 and a space occupied vessel No. 2 in a symmetrical structure.

The method of claim 3,
The non-mixed space occupied container has a fluid inlet and a fluid inlet on the upper and lower sides thereof, and a fluid for preventing mixing of raw water and membrane filtration produced water between the raw water and the membrane filtration module, And a mixing prevention cloth.

5. The method of claim 4,
Wherein the fluid mixing prevention cloth is fixed to a point where the space occupied vessel No. 1 and the space occupied vessel No. 2 are coupled symmetrically in the up-and-down direction within the fluid-to-fluid non-mixing space occupying vessel, Wherein the inflow fluid occupies all the spaces in the non-mixed space occupying vessel by flowing the fluid into one of the fluid inlet and outlet of the fluid mixing preventing vat, thereby filling the fluid mixing preventing vat. system.

5. The method of claim 4,
The fluid mixing prevention cloth is fixed to either one of the space occupied container 1 and the space occupied container 2 at one of the fluid outlets at the inside of the non-mixed space occupying container, Wherein the inflow fluid occupies all the spaces in the non-mixed space occupied vessel by flowing fluid into the entrance and being filled in the fluid mixture preventing vat.

5. The method of claim 4,
In the non-mixed space occupying vessel, the fluid mixing preventing cap is separated toward the upper and lower fluid access openings of the non-mixed space occupying vessel and closes the upper and lower fluid access openings of the non-mixed space occupying vessel Further comprising a fluid mixing preventing and releasing prevention plate at upper and lower fluid inlet and outlet of the non-mixed space occupying vessel.