Membrane filter device for oily water filtration

Abstract

The membrane filter apparatus according to the present invention includes one or more filter housings; one or more membrane filters disposed within the one or more filter housings; one or more lower caps attached to the lower end of each of the one or more filter housings via a first housing coupling member and containing a raw water inlet; one or more upper caps attached to the upper end of each of the one or more filter housings via a second housing coupling member and containing a first outlet and a second outlet; and an air supply port for supplying air to the internal space of the upper caps. The first filtered water, obtained by filtering raw water injected through the inlet through one or more membrane filters, is discharged through the first outlet. Here, backwashing is performed so that the water injected through the first outlet comes into contact with air.

Description

Technical Field

[0001] The present invention relates to a membrane filter for filtering oily water, and more particularly, to the structure and function of a membrane filter device for producing treated water that meets the oily water discharge standards.

Background Art

[0002] A membrane refers to a filtering material that performs a filtration function by selectively allowing only specific components in the input seawater, fresh water, or oily water to pass through. A membrane can not only filter dissolved substances dissolved in a liquid, but also separate a mixed gas.

Summary of the Invention

Problems to be Solved by the Invention

[0003] The present invention has been devised to solve the above-mentioned problems, and an object of the present invention is to provide the structure and function of a membrane filter device for producing treated water that meets the oily water discharge standards.

[0004] The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those of ordinary skill in the art from the following description.

Means for Solving the Problems

[0005] <000002A membrane filter device according to one embodiment of the present invention comprises one or more filter housings; one or more membrane filters disposed within the one or more filter housings; one or more lower caps attached to the lower end of each of the one or more filter housings via a first housing coupling member and containing a raw water inlet; one or more upper caps attached to the upper end of each of the one or more filter housings via a second housing coupling member and containing a first outlet and a second outlet; and an air supply port for supplying air to the internal space of the upper cap. The first filtered water and condensed water, filtered through the one or more membrane filters using raw water injected through the inlet, can be discharged through the second outlet. Furthermore, as backwashing is performed, the water injected through the first outlet comes into contact with the air.

[0006] Furthermore, the pore size of the membrane is 0.05 to 0.25 μm.

[0007] The condensed water generated when the raw water injected through the inlet is filtered through one or more membrane filters, and the condensed water generated when the backwashing is performed, are stored in i) a first storage space contained in one or more upper caps or a second storage space located in at least one of the one or more filter housings, or ii) an external storage container connected to the membrane filter device.

[0008] The first outlet and the second outlet may be located in the side region of one or more upper caps.

[0009] Furthermore, each of the one or more filter housings includes stainless steel material.

[0010] The first housing coupling member allows the one or more lower caps to be attached to and detached from the one or more filter housings, and the second housing coupling member allows the one or more upper caps to be attached to and detached from the one or more filter housings.

[0011] Furthermore, one or more membrane filters can be attached to or detached from one or more filter housings.

[0012] Furthermore, the internal space of the upper cap and the upper space of the filter housing are defined as a single space.

[0013] Furthermore, the particle size of the emulsion present in either the second filtered water or the condensed water may be between 0.2 and 8.0 μm.

[0014] The one or more membrane filters may then be cleaned with an oily water cleaning solution composition. Here, the oily water cleaning solution composition may be some of the embodiments described herein.

[0015] Furthermore, the concentration of one or more oils contained in either the second filtered water or the condensed water may be 0 ppm.

[0016] Furthermore, the pore size of the membrane may be between 0.10 and 0.20 μm. [Effects of the Invention]

[0017] Various embodiments of the present invention provide the structure and function of an oil-based water filtration membrane filter device for producing treated water that conforms to oil-based water discharge standards.

[0018] Furthermore, with various embodiments of the present invention, as the membrane filter is detachably coupled to the housing, filter replacement becomes easier, and it can be easily attached and detached as needed during the work process.

[0019] Moreover, according to various embodiments of the present invention, contaminants of oil components can be filtered more efficiently at the upper cap outlet of the membrane filter.

[0020] The present invention is not limited to the effects mentioned above, and there are additional effects not mentioned, which will be clearly understood by those skilled in the art from the following description.

Brief Description of Drawings

[0021] [Figure 1] It is a diagram for explaining the structure of a unit membrane filter element according to an embodiment of the present invention. [Figure 2a] It is a diagram for explaining the structures of an upper cap and a lower cap according to an embodiment of the present invention. [Figure 2b] It is a diagram for explaining the structures of an upper cap and a lower cap according to an embodiment of the present invention. [Figure 2c] It is a diagram for explaining the structures of an upper cap and a lower cap according to an embodiment of the present invention. [Figure 3] It is a drawing for explaining the structure of a membrane filter device in which a plurality of membrane filter elements are combined according to an embodiment of the present invention. [Figure 4A] The process of discharging filtered water and condensed water through a membrane filter device according to an embodiment of the present invention is described. [Figure 4B] The process of discharging filtered water and condensed water through a membrane filter device according to an embodiment of the present invention is described. [Figure 5] It is a drawing for explaining a method of performing a water supply (Filing) process according to an embodiment of the present invention. [Figure 6] It is a drawing for explaining a method of performing a filtration process according to an embodiment of the present invention. [Figure 7] It is a drawing for explaining a method of performing backwashing according to an embodiment of the present invention. [Figure 8] This is a diagram illustrating a method for performing a drainage process according to one embodiment of the present invention. [Figure 9] This is a diagram illustrating a chemical cleaning process according to one embodiment of the present invention. [Figure 10] This is a diagram illustrating a chemical recycling process according to one embodiment of the present invention. [Figure 11] This is a diagram illustrating a chemical discharge process according to one embodiment of the present invention. [Figure 12] This is a diagram illustrating the rinsing process according to one embodiment of the present invention. [Figure 13] This is a diagram illustrating a drainage process according to one embodiment of the present invention. [Modes for carrying out the invention]

[0022] The advantages and features of the present invention, and methods for achieving them, will become clearer with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments described below and can be embodied in a variety of different forms, and these embodiments are provided merely to complete the invention and to fully inform those ordinary people skilled in the art to which the invention belongs of the scope of the invention, and the invention is defined only by the scope of the claims.

[0023] The terms used herein are for illustrative purposes only and are not intended to limit the invention. In this specification, singular terms include plural terms unless otherwise specified in the text. The terms “comprises” and / or “comprising” as used in this specification do not preclude the presence or addition of one or more other components in addition to those mentioned.

[0024] Throughout the specification, the same reference numerals refer to the same component, and "and / or" includes each of the components mentioned and all combinations of one or more of them. Even if terms such as "first," "second," etc., are used to describe a variety of components, these components are not limited by these terms. These terms are simply used to distinguish one component from another. Therefore, the first component mentioned below may, of course, be the second component within the technical concept of the present invention.

[0025] Unless otherwise defined, all terms used herein (including technical and scientific terms) should be used in a way that is commonly understood by a person of ordinary skill in the art to which this invention pertains. Furthermore, terms defined in commonly used dictionaries should not be interpreted ideally or excessively unless explicitly defined otherwise.

[0026] Spatially relative terms such as "below," "beneath," "lower," "above," and "upper" can be used to easily describe the correlation between one component and another, as shown in the drawings. Spatially relative terms should be understood as terms that include the different directions of components in use or operation, in addition to the directions shown in the drawings.

[0027] For example, when reversing a component shown in a drawing, a component described as "below" or "beneath" another component can be placed "above" it. Therefore, the exemplary term "below" can encompass both downward and upward directions. Components can also be oriented in other directions, thus allowing spatially relative terms to be interpreted by orientation.

[0028] In this specification, the range of numbers indicated using the term 'to' refers to a range of numbers that includes the values ​​listed before and after the term as the lower and upper limits, respectively. If multiple numerical values ​​are invented for the upper and lower limits of any given range of numbers, the range of numbers invented in this specification can be understood as any range of numbers whose lower limit is any one of the multiple lower limits and whose upper limit is any one of the multiple upper limits, respectively.

[0029] Figure 1 is a diagram illustrating the structure of a unit membrane filter element according to one embodiment of the present invention.

[0030] A membrane filter device can mean a device that combines one or more unit membrane filter elements. A unit membrane filter element means a structure in which other components are attached to a unit filter housing 110. For the sake of explaining the present invention, Figure 1 assumes that the membrane filter device has one unit membrane filter element.

[0031] A membrane filter device (100) according to one embodiment of the present invention may include a filter housing, one or more membrane filters (120-1, 120-2), an upper cap (130), and a lower cap (140).

[0032] The filter housing 110 may be made of stainless steel. If the filter housing 110 is made of stainless steel, its weight can be reduced. It can also prevent warping or burning of the filter housing due to fire or heat inside the ship. If the filter housing is made of carbon steel, an increase in thickness is required to account for the corrosion margin, and the increased weight of the filter housing may make installation and removal operations difficult.

[0033] One or more membrane filters (120-1, 120-2) can be placed within the filter housing. For example, one or more membrane filters 120-1, 120-2 can be attached to the filter housing in a detachable manner.

[0034] Conventionally, in a system where the membrane filter is fixed to the upper end of the filter housing, contaminants on the membrane filter accumulate densely at the top of the filter housing. Even if an outlet is provided around the area where the contaminants are concentrated (for example, on the side), the aggregation of the contaminants prevents effective discharge.

[0035] According to one aspect of the present invention, the efficiency of pollutant discharge can be further enhanced by detachably connecting one or more membrane filters within the filter housing.

[0036] Figure 1 illustrates a case in which two membrane filters 120-1 and 120-2 are provided / attached inside the filter housing 110, but is not limited to this. One or more membrane filters may be provided / attached inside the filter housing 110.

[0037] If the membrane filters (120-1, 120-2) become severely contaminated or if the differential pressure within the membrane filters (120-1, 120-2) increases, they can be easily removed from the filter housing and replaced.

[0038] According to one embodiment of the present invention, the pore size of the membrane in the membrane filters 120-1 and 120-2 may be 0.05 to 0.25 μm, 0.07 to 0.24 μm, 0.08 to 0.20 μm, or 0.10 to 0.20 μm. When the pore size of the membrane satisfies the above numerical range, oil particles contained in the raw water can be effectively filtered by the internal pores of the membrane filter.

[0039] According to yet another embodiment of the present invention, the membrane filters 120-1 and 120-2 may include pressurized hollow fiber. According to one aspect of the present invention, by using hollow fiber with a relatively large surface area as the membrane filter, contaminants, oil, etc. contained in the raw water can be filtered more effectively.

[0040] A lower cap (130) is attached to the lower end (or lower region) of the filter housing (110) via a first housing coupling member. The lower cap (130) includes an inlet (140) into which raw water is injected and an air supply port (135).

[0041] The air supply port (135) according to the present invention supplies air to the water injected through the first outlet 160 when backwashing is performed. In some examples, the air supply port (135) may be located at the lower end of the lower cap (130), specifically, it may be located opposite the inlet (140). According to some embodiments of the present invention, the air supply port (135) is located at the lower end of the lower cap (130), and the area in which the water injected through the first outlet comes into contact with the air during backwashing increases over time, and the cyclone can be made more strongly. This can lead to higher backwashing efficiency. If the air supply port is located at the upper end of the filter housing (110), the cyclone cannot be made sufficiently strongly, and the backwashing efficiency cannot be made more efficient.

[0042] Furthermore, according to another embodiment of the present invention, the air supply port (135) can supply air bubbles in addition to the air. Here, air bubbles refer to air surrounded by a liquid (e.g., water), unlike air which is composed of pure gas. In other words, the air supply port (135) plays the role of supplying both air and air bubbles.

[0043] Furthermore, according to another embodiment of the present invention, the membrane filter device may include more air bubble supply units (not shown) connected to the air supply port (135). Unlike the embodiment described above, an additional air bubble supply unit is provided to supply air bubbles to the air supply port (135).

[0044] In yet another embodiment of the present invention, air bubbles are additionally included in addition to the air, and even higher backwashing efficiency can be expected. For example, the volume ratio of the air to the air bubbles may be 9:1 to 5:5, or 8:2 to 7:3.

[0045] Here, the raw water may include one or more mixtures selected from the group consisting of seawater, freshwater, and oily water. That is, the user can inject the raw water into the inlet 140 to filter out various contaminants contained in the raw water through the membrane filter device 100.

[0046] An upper cap 150 is attached to the upper end (or upper region) of the filter housing 110 via a second housing coupling member. The upper cap 150 may include a first outlet 160, a second outlet 170, and / or a storage space (e.g., a specific space in the upper cap 150) 180 for storing condensate.

[0047] In yet another embodiment of the present invention, filtered water is discharged through the first outlet 160, and residues accumulate in the upper cap (150) of the wastewater tank function. During backflushing, the wastewater flowing in through the first outlet (160) combines with air supplied through the air supply port (135) to create a powerful cyclone. This is then discharged through the second outlet (170) located in the upper cap (150), preventing membrane contamination and maintaining performance over time. In contrast, in existing systems, after the membrane filters and allows dissolved substances in the liquid to pass through, the remaining residue continuously accumulates in the upper part of the filter housing connected to the lower part of the upper cap. This contaminates the membrane, degrading its performance and gradually leading to the loss of membrane function. Furthermore, during backflushing, the wastewater flowing in through the first outlet (160) combines with air supplied through the air supply port (135) and is discharged to the second outlet on the side of the filter housing, but it becomes impossible to remove the residue accumulated in the upper part of the filter housing. The present invention is mounted on an upper cap (150) that functions as a wastewater tank and completely processes the residue through backflushing that takes place approximately every 20 minutes, maintaining a state in which the membrane can continuously process flowing water at an operating pressure of 3 BAR or more. Considering that the membrane is composed of fine pores, existing methods may have limitations in operating pressure, and there is a possibility that the performance of the membrane will continuously deteriorate during operation.

[0048] Specifically, the internal space of the upper cap 150 and the upper space of the filter housing 110 can be defined as a single space. That is, the internal space of the upper cap 150 and the upper space of the filter housing 110 can be directly connected. Air or other substances in the upper space of the filter housing 110 can move into the internal space of the upper cap 150.

[0049] As a result, the condensed water that has passed through one or more membrane filters (120-1, 120-2) in the filter housing can be stored in a storage space (180) for storing the condensed water.

[0050] Additionally or alternatively, the upper cap 150 may include a first storage member for storing additional condensed water, and the filter housing 110 may include a second storage member for storing additional condensed water.

[0051] As shown in Figure 1, for example, the first outlet 160 and the second outlet 170 can be located in the side region of the upper cap 180.

[0052] The lower cap 130 and the filter housing 110 can be attached and detached by the first housing coupling member. The upper cap 150 and the filter housing 110 can be attached and detached by the second housing coupling member.

[0053] In other words, the filter housing 110 can be easily detached from the lower caps 130 and 150. This can lead to the technical advantage of being able to easily separate and replace the filter housing 110 even in narrow areas and at limited heights within a ship.

[0054] The process by which various filtered waters and condensed waters are discharged through the first outlet 160, the second outlet 170, and the storage member 180 will be explained in detail with reference to Figures 4A and 4B.

[0055] For example, the length from the central region of the second outlet 170 to the inlet 140 is 1816 mm, the length from the upper end of the upper cap 150 to the inlet 140 is 1879 mm, and the length from the upper end of the first outlet 160 to the inlet 140 is 1886 mm.

[0056] However, this is only one embodiment, and the lengths and widths between the components of the membrane filter device 100 may vary.

[0057] Figures 2a to 2c are diagrams illustrating the structure of the upper cap and lower cap according to one embodiment of the present invention.

[0058] As explained with reference to Figure 1, the upper cap can be fitted with a first outlet and a second outlet, and the lower cap can be fitted with an inlet.

[0059] As shown in Figure 2a, a first connecting member 180 is configured to connect / attach the first and second outlets to the external pipe, and a second connecting member 190 is configured within the membrane filter device to connect / attach the inlet to the external pipe.

[0060] Figure 2b shows the structure of the first connecting member 180 for connecting / attaching the first and second outlets to the external pipe, respectively.

[0061] A gasket is connected to / attached to the first outlet and / or the second outlet. The first outlet and / or the second outlet can be connected to the first connecting member 180 through the gasket. The filtered water and / or condensed water discharged through the first outlet and / or the second outlet can then be discharged through a pipe. The values ​​shown in Figure 2b are merely examples and may be determined to be other values.

[0062] Figure 2c shows the structure of the second connecting member 190 for connecting / attaching each of the inlets (i.e., membrane modules) to the outer pipe.

[0063] A gasket may be connected to / attached to the inlet. The inlet and the second connecting member 190 can be connected through the gasket. The raw water injected through the pipe can then be transmitted through the inlet into the membrane filter device. The values ​​shown in Figure 2c are merely examples and may be determined to be other values.

[0064] For example, the separation distance between the gasket and the first connecting member 180 may be 1.0 to 2.0 mm, 1.2 to 1.8 mm, 1.5 to 1.7 mm, or 1.6 mm. Furthermore, the separation distance between the gasket and the second connecting member 190 may be the same as or different from the separation distance between the gasket and the first connecting member 180.

[0065] Figure 3 is a diagram illustrating the structure of a membrane filter device in which multiple membrane filter elements are coupled together, according to one embodiment of the present invention. Although Figure 3 illustrates a membrane filter device composed of two membrane filter elements, the number of membrane filter elements can be determined to a variety of values.

[0066] As shown in Figure 3, the membrane filter device (1000) is composed of a first membrane filter element and a second membrane filter element (200). The structure of the first membrane filter element and the second membrane filter element (200) can be configured as shown in Figure 1, and the membrane filter device (1000) is formed when the first membrane filter element and the second membrane filter element (200) are connected to each other.

[0067] One or more pipes are connected to the first outlet, the second outlet, and the inlet, which are contained in the first membrane filter element and the second membrane filter element (200), respectively.

[0068] Figures 4A and 4B illustrate the process by which filtered water and condensed water are discharged through a membrane filter device according to one embodiment of the present invention. For the convenience of explaining the present invention, Figures 4A and 4B assume that there is one unit membrane filter element in the membrane filter device.

[0069] Figure 4A is a diagram illustrating the filtering procedure using a membrane filter device.

[0070] Based on the injection of raw water through the inlet, the raw water passes through one or more membrane filters attached to the filter housing. This allows various oil residues and suspended solids to be filtered out. The first filtered water, from which the various oil residues and suspended solids have been filtered out, is discharged through the first outlet 160.

[0071] In this case, the valve of the second outlet may be locked, and the condensed water containing various oil residues and suspended solids is stored in a storage member / storage space contained in the upper cap and / or filter housing (110).

[0072] Additionally or alternatively, condensed water containing various oil residues and suspended solids may be stored in a separate external storage container connected to the membrane filter device.

[0073] Figure 4B is a diagram illustrating the back-flushing procedure using a membrane filter device.

[0074] Based on the injection of fresh water through the first outlet 160, a backwashing procedure can be performed to remove contaminants adhering to one or more membrane filter surfaces contained in the filter housing (110). The second filtered water and condensed water generated by the backwashing are discharged through the second outlet (170). The particle size of the emulsion contained in at least one of the second filtered water and condensed water may be 0.2 to 0.8 μm. The concentration of oil contained in at least one of the second filtered water and condensed water is 0 ppm.

[0075] In this case, the condensed water includes not only the condensed water generated by backwashing, but also the condensed water that was stored in the storage component / space.

[0076] As described above, the positioning of the first outlet (160) and the second outlet (170) at the top of the filter housing can increase the lifespan of the membrane filter.

[0077] Specifically, by positioning the second outlet (170) in the upper cap and connecting the upper cap and the upper space of the filter housing (110) as a single space, the internal space of the upper cap (i.e., the space within the storage member) can be utilized as a space for collecting oil components that contaminate the membrane filter.

[0078] Oil components and other substances present in the internal space of the upper cap (i.e., the space within the storage member) are discharged through the second outlet 150 during the backwashing procedure, thereby minimizing contamination of the membrane filter and increasing its lifespan.

[0079] In yet another embodiment of the present invention, the filtering operation shown in Figure 4A and the backwashing operation shown in Figure 4B are performed simultaneously. Specifically, while the raw water introduced through the inlet passes through one or more membrane filters, the backwashing procedure can also be performed using water introduced through the first outlet.

[0080] According to yet another embodiment of the present invention, a ship exhaust gas water treatment device including the membrane filter device can be provided. Therefore, the claims of the present invention can be changed from a membrane filter device to a ship exhaust gas water treatment device. According to one aspect of the present invention, when the membrane filter device is applied to a ship exhaust gas water treatment device, treated water that conforms to discharge standards can be discharged by effectively filtering oil particles from the raw water.

[0081] The membrane filtration process refers to the process of producing filtered water that meets ship discharge regulations by removing oil sludge and / or suspended solids from raw water (or treated water) produced by a water treatment module (or unit) through a membrane filter and / or hollow fiber membrane filter. Continuous cleaning of the membrane filter equipment and associated piping is necessary to efficiently carry out the membrane filtration process.

[0082] Here, the raw water may include one or more types selected from the group consisting of seawater, freshwater, and oily water.

[0083] A membrane filtration process according to one embodiment of the present invention may consist of i) normal operation of the membrane filtration equipment and ii) chemical cleaning (Cleaning in place, CIP) of the membrane filter with chemicals.

[0084] Normal operation may consist of a water supply process, a filtration process, a backwashing process, and a drainage process. Here, the backwashing process may be performed after the filtration process has stopped and before it restarts. Chemical cleaning may consist of an operation to inject chemicals into the cleaning cylinder, a chemical circulation process, a discharge process, a rinsing process, and a drainage process.

[0085] When a membrane filter system is newly installed as part of the filtration process equipment, the normal operating cycle (i.e., the water supply process, filtration process, backwashing process, and wastewater discharge process) can be carried out in advance to ensure the stability of normal operation.

[0086] The operating time for each process can be adjusted according to the basic setting time and / or design conditions. The operating time for each process can be changed from the basic setting time depending on changes in the water quality of the raw water supplied from the water treatment module and other conditions.

[0087] The following section will specifically describe the process of constructing the membrane filtration system with reference to the diagrams.

[0088] Figure 5 is a diagram illustrating a method for carrying out the water supply (firing) process according to one embodiment of the present invention.

[0089] The water supply process refers to the process of filling one or more membrane filter devices 100, 200 with raw water through a water supply module (i.e., a water treatment unit, WTU) 10.

[0090] Specifically, the WTU raw water supply valve connected to the WTU 10 can be opened while the back-flushing pump 32 is open. That is, the WTU 10 can supply raw water to the piping connected to the WTU 10 and to one or more membrane filter devices 100, 200 included in the filtering module 20 by opening the valve connected to the tank 13 containing raw water and operating the water supply pump 15 connected to the tank 13. In this case, the WTU 10 can operate the water supply pump 15 for a preset time (for example, 20 seconds).

[0091] During the water supply process, the valve at the outlet of the membrane filter device and all other valves may be kept closed.

[0092] Figure 6 is a diagram illustrating a method for carrying out a filtration process according to one embodiment of the present invention.

[0093] The filtration process refers to the process of passing the raw water supplied from the WTU 10 through one or more membrane filter devices 100, 200 to remove oil sludge and suspended solids from the raw water.

[0094] As described above, the WTU 10 can supply raw water to one or more membrane filter devices 100, 200 through piping 22 connected to the WTU 10 by opening a valve connected to a tank 13 containing raw water and operating a water supply pump 15 connected to the tank 13.

[0095] Specifically, the filtering module (20) can input raw water supplied from the WTU into one or more membrane filter devices (100, 200) to obtain filtered water and first condensate. The particle size of the emulsion contained in the first condensate may be 0.2 to 8.0 μm. The device can discharge the filtered water through piping (or pipes) 24 connected to the first outlets of one or more membrane filter devices 100, 200.

[0096] At this time, the upper caps located at the upper end of one or more membrane filter devices may include a storage space for collecting the first condensate. The first condensate obtained by one or more membrane filter devices 100, 200 may be stored in the storage space.

[0097] Figure 7 is a diagram illustrating a method for performing back-flushing according to one embodiment of the present invention.

[0098] The backwashing process (or / and air droplet washing process) is a process in which contaminants adhering to the surface and pores of the membrane filter are removed by supplying fresh water (i.e., backwash water) from the secondary membrane to the primary membrane side during the membrane filtration process.

[0099] The backwash module 30 can operate the backwash pump 32 to supply backwash water to the filtering module 20. At this time, the backwash module (30) can supply bubbles to the backwash water through the backwash pump and / or the piping connected thereto.

[0100] To efficiently backwash the membrane filter, the backwash pump 320 can supply backwash water with a sufficient flow rate to the filtering module 20. The flow rate of the backwash water supplied to the filtering module 20 by the backwash module 30 may be 3 bar * 3 m³ / h to 6 bar * 5 m³ / h.

[0101] In other words, based on the fact that backwash water supplied from the backwash module is input to the first outlet to obtain second condensate, one or more first and second condensates can be discharged through piping (32) connected to the second outlet of the membrane filter device (100, 200). The first and second condensates discharged through piping 32 connected to the second outlet are stored in an EGR drain tank.

[0102] As an example of the present invention, while raw water is supplied from the water treatment module 10 to the filtering module 20, backwash water is supplied from the backwash module 30 to the filtering module 20, and while filtered water is discharged through the first outlet, first condensed water and second condensed water can be discharged through the second outlet. Here, the particle size of the emulsion contained in the second condensed water may be 0.2 to 8.0 μm. That is, the filtration process and the backwash process can be performed simultaneously.

[0103] Figure 8 is a diagram illustrating a method for performing a drainage process according to one embodiment of the present invention.

[0104] Once the backwashing process, as described with reference to Figure 8, is complete, the filtering module 20 opens the discharge valve connected to the vent and the second outlet, thereby draining the first and second condensates.

[0105] Figure 9 is a diagram illustrating a chemical cleaning process according to one embodiment of the present invention.

[0106] The chemical cleaning (CIP) process refers to the process of cleaning the membrane filter with chemical components when the differential pressure approaches the operating limit differential pressure (e.g., 1.0 bar, 100 kPa) after backwashing due to prolonged operation of the membrane filter device or changes in the quality of the WTU treated water.

[0107] The chemical cleaning cycle can be increased or decreased depending on the situation, as the trend of differential pressure increase varies depending on the condition of the membrane filter, the water quality of the WTU treated water, etc. However, the differential pressure must not exceed the operating limit differential pressure, and if the chemical cleaning cycle increases, it may be judged that the membrane is damaged.

[0108] The system according to the present invention may include a control device that controls the WTU, filtering module, backwash module, and CIP module (40). If it is determined that the cycle in which the CIP module performs chemical cleaning is less than the critical period, the control device can transmit a message to a terminal device used by the system administrator requesting the replacement of a membrane filter in one or more membrane filter devices 100, 200.

[0109] As an example of the present invention, after the first condensate (i.e., condensate produced through the filtration process) and the second condensate (i.e., condensate produced through the backwashing process) are discharged through the second outlet of the membrane filter device, the CIP module 40 can perform chemical cleaning on one or more membrane filter devices 100, 200 based on the fact that the pressure inside one or more membrane filter devices 100, 200 is within a critical range.

[0110] Additionally or alternatively, the CIP module 40 can perform chemical cleaning on one or more membrane filter devices 100, 200 at predetermined intervals. The oily water cleaning solution composition for membrane filters used in the chemical cleaning comprises a chemical cleaning solution and water.

[0111] The oily water cleaning solution composition for membrane filters according to the present invention comprises a chemical cleaning solution and water.

[0112] The chemical cleaning solution according to the present invention comprises a wetting agent, a stabilizer, a surfactant, an emulsifying film remover, and purified water.

[0113] Humectant The wetting agent according to the present invention not only embodies high cleaning and emulsifying power in the cleaning solution composition, but also contributes to the good mixing of contaminants adhering to the surface of the membrane filter with water. Furthermore, the wetting agent according to another aspect of the present invention can effectively prevent excessive foaming in the oily water cleaning solution composition for membrane filters.

[0114] The content of the wetting agent according to the present invention may be 6-14% by weight, 7-13% by weight, 8-12% by weight, 9-11% by weight, or 10-11% by weight, based on the total weight of the chemical cleaning solution. Specifically, if the content of the wetting agent is less than the above numerical range, contaminants adhering to the surface of the membrane filter may not mix well with the water, and the chemical cleaning function may not proceed effectively. If it exceeds the above numerical range, the flowability of the cleaning solution composition may decrease, and the cleaning efficiency may decrease.

[0115] The wetting agent according to the present invention may include a sulfonate. Specifically, the sulfonate can not only achieve higher cleaning and emulsifying power compared to other types of wetting agents, but can also better contribute to the mixing of contaminants and other substances adhering to the surface of the membrane filter with water.

[0116] For example, the sulfonate may be one or more selected from the group consisting of sodium xylenesulfonate, sodium dodecylbenzenesulfonate, and sodium perfluorooctane sulfonate. However, the technical concept of the present invention is not limited thereto, and any sulfonate that acts as a wetting agent is applicable.

[0117] Stabilizer The stabilizer according to the present invention can contribute to the good dispersion of lipophilic contaminants attached to the membrane filter in water. As a result, the stabilizer can effectively prevent the lipophilic contaminants from separating separately by ensuring good dispersion of the lipophilic contaminants in water, thereby realizing a stabilizing effect on the cleaning solution composition.

[0118] The stabilizer according to the present invention may be 1-9% by weight, 2-8% by weight, 3-7% by weight, 4-6% by weight, or 5-6% by weight based on the total weight of the chemical cleaning solution. Specifically, if the content of the stabilizer is less than the above numerical range, lipophilic contaminants may not disperse well in water and may separate from the water, and if it exceeds the above numerical range, the flowability of the cleaning solution composition may decrease, resulting in a decrease in cleaning efficiency.

[0119] For example, the stabilizer may be one or more selected from the group consisting of sodium tripolyphosphate, sodium hexametaphosphate, sodium polymetaphosphate, disodium pyrophosphate, and sodium carboxymethylcellulose.

[0120] surfactants The surfactant according to the present invention can mitigate the interface between lipophilic contaminants adhering to the membrane filter and water. As a result, the surface tension at the interface between the lipophilic contaminants and water is weakened, allowing the lipophilic contaminants adhering to the membrane filter to be effectively removed.

[0121] The surfactant according to the present invention may include one or more selected from the group consisting of anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants, and specifically may include a nonionic surfactant. According to one embodiment of the present invention, by using a nonionic surfactant as the surfactant, it is possible to achieve not only excellent cleaning action even at low temperatures, but also the effect of producing less foam in the cleaning solution composition.

[0122] For example, the anionic surfactant may contain a hydrophilic functional group as a substance that has the property of reducing surface tension by having the anions generated when it dissociates in water adsorbed onto the surface of the aqueous solution. Here, the hydrophilic functional group may include one or more of a carboxyl group, a phosphate group, and a sulfonate group. To illustrate, the anionic surfactant may be one or more selected from the group consisting of lauryl ammonium phosphate, cetyl ammonium phosphate, tetradecyl ammonium phosphate, lauryl ammonium sulfate, cetyl ammonium sulfate, dodecylbenzeneammonium sulfate, ammonium hexadecyl ether sulfate, tridecyl ammonium phosphate, tetradecyl ammonium phosphate, dilauryl ammonium phosphate, dicetyl ammonium phosphate, ditridecyl ammonium phosphate, tetradecyl ammonium sulfate, tridecylbenzeneammonium sulfate, dodecyl ammonium sulfate, hexadecyl ammonium sulfate, and lauryl ammonium carboxylate.

[0123] For example, a cationic surfactant is a substance that has the property of reducing surface tension by having the cations produced when it dissociates in water adsorb to the surface of the aqueous solution. To give one example, the cationic surfactant may be any one selected from the group consisting of stearyl alkonium chloride, stearyltrimonium chloride, distearyl-dimonium chloride, and mixtures thereof.

[0124] For example, the aforementioned amphoteric surfactant is a compound that can change between an anionic, cationic, or nonionic state in an aqueous solution depending on the pH of the water. For example, the amphoteric surfactant may be one or more selected from the group consisting of didecylethanolamine oxide, dodecyldimethylamine oxide, tetradecyldimethylamine oxide, hexadecyldimethylamine oxide, octadecyldimethylamine oxide, cocodimethylamine oxide, cocobis(2-hydroxyethyl)amine oxide, dicocodimethylamine oxide, dicocoethanolamine oxide, cocoylamidopropyldimethylamine oxide, talodimethylamine oxide, talodiethanolamine oxide, ditalomethylamine oxide, ditalomethylamine oxide, ditaloethanolamine oxide, di(hydrogenated talo)methylamine oxide, taloylamidopropyldimethylamine oxide, 9-octadecenoyldimethylamine oxide, N-cocomorpholine N-oxide, cocodimethylbetaine, cocoylamidopropyldimethylbetaine, lauroylamidopropyldimethylbetaine, coamphocarboxyglycinate, and N-coco-3-aminobutyric acid.

[0125] For example, the nonionic surfactant may be one or more selected from the group consisting of alkyl polyglucoside, polyoxyethylene polyoxypropylene condensate, polyoxyethylene polyoxybutylene condensate, glycerin-added polyoxyethylene polyoxypropylene condensate, ethylenediamine-added polyoxyethylene polyoxypropylene condensate, polyoxyalkylene alkyl ether, polyoxyalkylene alkylphenol ether, polyoxyalkylene arylphenol ether, polyoxyalkylene fatty acid ester, polyoxyalkylene sorbitan fatty acid ester, polyoxyalkylene alkylamine, sorbitan fatty acid ester, alkyl alcoholamine, and aryl alcoholamine.

[0126] The surfactant content according to the present invention may be 6-14% by weight, 7-13% by weight, 8-12% by weight, 9-11% by weight, or 10-11% by weight, based on the total weight of the chemical cleaning solution. If the surfactant content is below the above numerical range, the surface tension at the interface between the lipophilic contaminant and water may become too weak, resulting in a problem where the lipophilic contaminant adhering to the membrane filter is not effectively removed. If it exceeds the above numerical range, a problem may occur where the cleaning efficiency decreases.

[0127] Emulsifying film remover One aspect of the present invention provides an emulsifying film remover that can stabilize various impurities contained in oily water, effectively preventing the formation of emulsifying films in the cleaning solution composition and thereby enhancing cleaning power. Another aspect of the present invention provides an emulsifying film remover that can raise the pH of the cleaning solution composition, effectively separating lipophilic contaminants that adhere to the surface of the membrane filter along with the water.

[0128] The content of the emulsifying film remover according to the present invention may be 0.5 to 1.5% by weight, 0.6 to 1.4% by weight, 0.7 to 1.3% by weight, 0.8 to 1.2% by weight, or 0.9 to 1.1% by weight, based on the total weight of the chemical cleaning solution. If the content of the emulsifying film remover is below the above numerical range, impurities contained in the oily water may cause an excessive increase in the emulsifying film, resulting in a decrease in cleaning power. If the content exceeds the above numerical range, a problem may occur in which the cleaning effect is reduced.

[0129] For example, the emulsifying film remover may be any one selected from the group consisting of sodium metasilicate pentahydrate, sodium metasilicate nonahydrate, and mixtures thereof.

[0130] purified water The purified water according to the present invention can act as a solvent that dissolves various components contained in the chemical cleaning solution, thereby diluting the substance to be cleaned.

[0131] The content of purified water according to the present invention may be the remaining content after removing the above-mentioned composition based on the total weight of the chemical cleaning solution.

[0132] For example, the content of the purified water may be 70 to 78% by weight, 71 to 77% by weight, 72 to 76% by weight, 73 to 75% by weight, or 74 to 75% by weight, based on the total weight of the chemical cleaning solution. If the content of the purified water is below the above numerical range, a problem may occur in which various substances contained in the chemical cleaning solution are not well dissolved, and if it exceeds the above numerical range, a problem may occur in which the cleaning power against lipophilic contaminants adhering to the surface of the membrane filter is reduced.

[0133] Cleaning solution composition According to yet another embodiment of the present invention, the volume ratio of the chemical cleaning solution to the water may be 1:9 to 2:8. When the volume ratio of the chemical cleaning solution to the water satisfies the above numerical range, the chemical cleaning solution can be effectively dispersed in the water, and an excellent cleaning effect can be achieved.

[0134] According to a preferred embodiment of the present invention, the water mixed with the chemical cleaning solution is replaced with a C6-C8 ester compound having a halogen atom at its terminal. According to this embodiment of the present invention, the mixing of the chemical cleaning solution with the C6-C8 ester compound having a halogen atom at its terminal produces an effect that further reduces the differential pressure of the membrane filter. For example, the C6-C8 ester compound having a halogen atom at its terminal is 6-bromohexyl acetate.

[0135] Figure 10 is a diagram illustrating a chemical recycling process according to one embodiment of the present invention.

[0136] The chemical circulation process refers to the process of circulating a chemical cleaning solution (i.e., a mixture of fresh water and chemicals) through a membrane filter.

[0137] The CIP circulation valve and the chemical cleaning inlet valve may be in the open state. The CIP module 40 can operate the chemical cleaning fluid supply pump 44 to inject the chemical cleaning fluid into the filtering module 20. The membrane filter can be cleaned with the chemical cleaning fluid for a certain period of time (e.g., 40 minutes).

[0138] For example, if it is determined that foam has been generated in the CIP tank, the CIP module (40) can add a predetermined defoaming agent to the CIP tank.

[0139] Figure 11 is a diagram illustrating a chemical discharge process according to one embodiment of the present invention.

[0140] Once the chemical recycling process is complete, the chemical cleaning solution can be recovered into the chemical cleaning solution tank 43 for reuse. If the degree of contamination of the chemical cleaning solution is above a predetermined value and therefore cannot be reused, the CIP module can activate the chemical cleaning solution discharge valve to send the chemical cleaning solution to the chemical waste tank 45.

[0141] Figure 12 is a diagram illustrating the rinsing process according to one embodiment of the present invention.

[0142] The rinsing process involves discharging contaminants and chemical cleaning agents separated from the membrane filter surface by the circulation of chemical cleaning solution and bubbles from the filtering module and the piping connected thereto, and then washing the filtering module and the piping connected thereto with fresh water. The cleaning valve connected to the backwash module (30) can be opened, allowing the backwash module (30) to clean the filtering module and the piping connected thereto for a set period of time (e.g., 60 seconds) by injecting fresh water into the filtering module (20). The cleaning water discharged during the rinsing process can be transferred to the chemical waste tank 45.

[0143] Once the rinsing process is complete, the chemical cleaning procedure is finished and the normal operation process can resume. If the degree of contamination or differential pressure of the membrane filter remains within the critical range after the CIP process, a manual chemical cleaning process may be performed.

[0144] Figure 13 is a diagram illustrating the drainage process according to one embodiment of the present invention.

[0145] Once the chemical discharge process is complete, the vents and drain valves may be opened, and chemical residues may be discharged through the membrane filter outlet (e.g., second outlet).

[0146] The following describes embodiments of the present invention in detail, so that those with ordinary skill in the art to which the present invention pertains can easily implement it. However, these are merely examples, and the scope of the rights of the present invention is not limited to the following.

[0147] [Example of manufacturing preparation: Manufacturing of chemical cleaning solution] A chemical cleaning solution was prepared according to the following preparation example 1. [Table 1]

[0148] [Example 1: Production of an oily water cleaning solution composition for membrane filters] Oil-based water cleaning solution compositions were prepared with the contents listed in Table 2 below. Meanwhile, the total capacity of the CIP tank was set to 200 L. [Table 2]

[0149] [Experimental Example 1: Results of the CIP process using a contaminated filter] Using the oily water cleaning solution composition described in Example 1, a CIP (Chemical in Place) process was performed for 41 minutes. As a result, the differential pressure of the membrane filter was measured using the following formula 1. [Formula 1] Differential pressure (△P) = P upstream -P downstream

[0150] In Equation 1 above, P upstream is the pressure upstream, and P downstream is the pressure downstream.

[0151] In Table 3 below, if the differential pressure is 0.1 bar or less, it means that the oily water, impurities, etc. contained in the membrane filter have been removed by the oily water cleaning solution composition of Example 1, and the function of the membrane filter has been restored to its original state. [Table 3]

[0152] [Experimental Example 2: Evaluation of differential pressure based on the type of sodium metasilicate hydrate] A cleaning solution composition was prepared in the same manner as in Example 1, and the type of hydrated sodium metasilicate was changed to produce cleaning solution compositions according to Comparative Examples 1 and 2, respectively. After 30 minutes of the CIP test, the differential pressure of the membrane filter was measured using the same method as in Experimental Example 1. [Table 4]

[0153] In Table 4 above, comparing Example 1, Comparative Examples 1 and 2 in terms of the differential pressure of the membrane filter depending on the type of hydrate, it was confirmed that Example 1, which contains metasilicate pentahydrate, Comparative Example 1, which contains metasilicate(9) hydrate, Comparative Example 2, which contains anhydrous metasilicate, and the comparative membrane filter differential pressure reached an appropriate level.

[0154] [Experimental Example 3: Case where the type of diluent is different from Example 1] The cleaning solution composition of Example 2 was prepared using the same method as in Example 1, but with a dilution consisting of 145 L of water and 5 L of standardized solvent instead of 150 L of water. [Table 5]

[0155] Referring to Table 5 above, it was confirmed that using a diluent composed of a mixture of water and a Stodard solvent resulted in an even lower differential pressure on the membrane filter. In this case, the Stodard solvent includes ester compounds with 6 to 8 carbon atoms having a halogen atom at the end. The ester compound may also be a saturated ester compound that does not contain carbon-carbon multiple bonds. Furthermore, the Stodard solvent may also be 6-bromohexyl acetate.

[0156] Additionally, various experiments have confirmed that satisfying a volume ratio of 29:1 between water and Stodard solvent further reduces the differential pressure of the membrane filter.

[0157] As described above, embodiments of the invention have been explained with reference to the attached drawings. Persons with ordinary skill in the art to which the present invention pertains will understand that the present invention may be carried out in examples different from those of the embodiments described without altering the technical idea or essential features of the invention. The embodiments described are illustrative only and should not be interpreted as limiting. [Explanation of symbols]

[0158] 100: Membrane filter device 110: Filter Housing 120-1, 120-2: Membrane filters 130: Lower cap 135: Air supply connecting member 140: Inlet 150: Top cap 160: 1st outlet 170:Second outlet 180: Storage space

Claims

1. One or more filter housings; One or more membrane filters disposed within the one or more filter housings; One or more lower caps are attached to the lower end of each of the one or more filter housings via a first housing coupling member, and each cap includes a raw water inlet. One or more upper caps attached to the upper end of each of the one or more filter housings via a second housing coupling member, and including a first outlet and a second outlet; An air supply port that supplies air to the internal space of the upper cap; Includes an air bubble supply unit connected to the air supply porter and supplying air bubbles to the air supply porter, The first filtered water, obtained by filtering the raw water injected through the inlet through one or more membrane filters, is discharged through the first outlet. The second filtered water and condensed water generated by backwashing the one or more membrane filters through the water injected through the first outlet are discharged through the second outlet. As a result of the backwashing, the water injected through the first outlet comes into contact with the air. The one or more membrane filters are washed with an oily water cleaning solution composition. The aforementioned oily water cleaning solution composition is Chemical cleaning solution Water, and It contains ester compounds with 6 to 8 carbon atoms having a halogen atom at the terminal, The aforementioned chemical cleaning solution is Sodium xylenesulfonate 10% by weight; 5% by weight of sodium tripolyphosphate; 10% by weight of alkyl polyglucoside; Metasilicate: Sodium pentahydrate: 1% by weight, Contains 74% by weight of purified water. The volume ratio of water to the ester compound is 29:

1. The volume ratio of the air and the air bubble is 9:1 to 5:

5. Membrane filter device.

2. The pore size of the membrane filter is 0.05 to 0.25 μm. The membrane filter apparatus according to claim 1.

3. The condensed water generated by filtering the raw water injected through the inlet through one or more membrane filters and the condensed water generated by the backwashing are stored in i) a second storage member located in at least one of the first storage spaces contained in one or more upper caps and one or more filter housings, or ii) an external storage container connected to the membrane filter device. The membrane filter apparatus according to claim 2.

4. The first outlet and the second outlet are located in the side region of the one or more upper caps. The membrane filter apparatus according to claim 3.

5. Each of the one or more filter housings includes a stainless steel material. The membrane filter apparatus according to claim 4.

6. The first housing coupling member allows the one or more lower caps and the one or more filter housings to be attached to and detached from each other. The one or more upper caps and the one or more filter housings are attached to and detached by the second housing coupling member. The membrane filter apparatus according to claim 5.

7. The one or more membrane filters are detachably attached to the one or more filter housings. The membrane filter apparatus according to claim 6.

8. The internal space of the upper cap and the upper space of the filter housing are defined as one space. The membrane filter apparatus according to any one of claims 1 to 7.

9. The concentration of oil contained in at least one of the second filtered water and the condensed water is 0 ppm. The membrane filter apparatus according to any one of claims 1 to 7.

10. The pore size of the membrane filter is 0.10 to 0.20 μm. The membrane filter apparatus according to any one of claims 1 to 7.

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