Method and system for purifying oily water using a membrane filter device

Abstract

A method and system for purifying oily water using a membrane filter device are disclosed. The oily water purification system using the membrane filter device according to an embodiment of the present invention includes: a water treatment module for supplying raw water; a filtering module including one or more membrane filter devices that receive the supply of raw water from the water treatment module; a back-flushing module for supplying back-flushing water to the filtering module; a chemical in place (CIP) module for performing chemical cleaning on the one or more membrane filters. The filtering module: based on inputting the raw water supplied by the water treatment module into the one or more membrane filter devices to obtain filtered water and first condensate, discharging the filtered water through a first discharge port of the one or more membrane filter devices, and based on inputting the back-flushing water supplied from the back-flushing module into the first discharge port to obtain second condensate, discharging the first condensate and the second condensate through a second discharge port of the membrane filter device.

Description

Technical Field

[0001] The present invention relates to the purification technology of oily water, and more particularly, to a method and a system for purifying oily water using a membrane filter device for filtering oily water.

Background Art

[0002] A membrane means a filter medium that performs a filtration function by selectively passing only specific components in the input seawater, fresh water, and / or oily water. A membrane can not only filter dissolved substances dissolved in a liquid but also separate a mixed gas. Depending on the material and structure of the membrane, the types of substances that can be separated by the membrane change, and the permeation rate / recovery rate can also be changed.

[0003] Filters combined with membrane materials are used in various industrial fields. As an example, conventionally, a technology for filtering an emulsion has been devised by attaching a filter combined with a membrane material and a centrifugal separator for oil-water separation to a ship exhaust gas water treatment system.

[0004] However, in the case of existing technologies, there is a problem that it is difficult to filter small-sized emulsions, and a more effective oily water filtration technology is required.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention attempts to solve the above-described problems. Further, an object of the present invention is to provide a method and a system for purifying oily water using a membrane filter device for filtering oily water. The problems to be solved by the present invention are not limited to the problems described above, and there are still other problems, which will be clarified by the following description.

Means for Solving the Problems

[0006] A system according to an embodiment of the present invention includes a water treatment module for supplying raw water; a filtering module including one or more membrane filter devices receiving the supply of raw water from the water treatment module; a back-flushing module for supplying back-flushing water to the filtering module; a chemical in place (CIP) module for performing chemical cleaning on the one or more membrane filters. The filtering module: inputs the raw water supplied by the water treatment module into the one or more membrane filter devices, discharges the filtered water through a first discharge port of the one or more membrane filter devices based on obtaining the filtered water and first condensate, inputs the back-flushing water supplied from the back-flushing module into the first discharge port, and discharges the first condensate and the second condensate through a second discharge port of the membrane filter device based on obtaining the second condensate.

[0007] And an upper cap located at the upper end of the one or more membrane filter devices can include a storage space for collecting the first condensate.

[0008] During the filtering process, while the raw water is supplied from the water treatment module to the filtering module, the filtered water is discharged through the first discharge port. When the back-flushing process is performed before restarting after stopping the filtering process to reduce the contamination load due to membrane fouling during operation, the back-flushing water is supplied from the back-flushing module to the filtering module, and the first condensate and the second condensate can be discharged through the second discharge port.

[0009] And the particle size of the emulsion contained in at least one of the first condensed water and the second condensed water may be 0.2 or 8.0 μm.

[0010] And the flow rate of the backwashing water supplied by the backwashing module is 3 bar * 3 m 3 / h or 6 bar * 5 m 3 / h in some cases.

[0011] And the backwashing module can include a pipe for supplying bubbles to the backwashing water.

[0012] And after discharging the first condensed water and the second condensed water through the second discharge port of the membrane filter device, based on the pressure in the one or more membrane filter devices being within a critical range, the CIP module can perform chemical cleaning on the one or more membrane filter devices.

[0013] And the CIP module can perform chemical cleaning on the one or more membrane filter devices at predefined intervals.

[0014] And a control device for controlling the water treatment module, the filtering module, the backwashing module, and the CIP module is further included, and the control device can: when it is determined that the period for the CIP module to perform chemical cleaning is less than a critical period, provide a message requesting replacement of the membrane filter in the one or more membrane filter devices.

Advantages of the Invention

[0015] According to various embodiments of the present invention, a method and a system for purifying oily water using a membrane filter device for oily water filtration can be provided.

[0016] Also, according to various embodiments of the present invention, the membrane filter is detachably coupled to the housing, facilitating the filter replacement operation and allowing it to be easily detached as needed during the working process.

[0017] Also, according to various embodiments of the present invention, oil-component contaminants can be filtered more efficiently from the upper cap outlet of the membrane filter. The effects of the present invention are not limited to the effects mentioned above, and further effects not mentioned will be clearly understood by those skilled in the art from the following description.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11a

Figure 11b

Figure 11c

DETAILED DESCRIPTION OF THE INVENTION

[0019] The advantages, features, and methods for achieving them of the present invention will become clear by reference to the embodiments described in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and can be embodied in various different forms. The embodiments considered so far are merely provided to complete the disclosure of the present invention and to fully inform those of ordinary skill in the technical field to which the present invention pertains of the scope of the present invention. The present invention is only defined by the scope of the claims.

[0020] The terms used in this specification are for explaining the embodiments and do not limit the present invention. In this specification, the singular form includes the plural form as well, unless otherwise specifically mentioned in the text. The "comprises" and / or "comprising" used in the specification do not exclude the presence or addition of one or more other components in addition to the mentioned components.

[0021] Throughout the specification, the same reference numerals refer to the same components, and "and / or" includes each and all combinations of the mentioned components. Even if terms such as "first", "second", etc. are used to describe various components, these components are of course not limited by these terms. These terms are merely used to distinguish one component from another. Therefore, it is natural that the first component mentioned below may be the second component within the technical idea of the present invention in some cases.

[0022] Unless otherwise defined, all terms (including technical and scientific terms) used herein shall be construed in accordance with their ordinary and customary meaning to those of ordinary skill in the art to which this invention pertains. Also, terms defined in commonly used dictionaries shall not be interpreted ideally or overly unless specifically defined otherwise.

[0023] Spatially relative terms such as "below", "beneath", "lower", "above", "upper", etc. may be used to describe the correlation between one component and another as shown in the drawings. Spatially relative terms should be understood to include different directions of components relative to each other during use or operation in addition to the direction shown in the drawings.

[0024] For example, when flipping the components shown in the drawings, a component described as "below" or "beneath" each component can be placed "above" another component. Thus, the exemplary term "below" can include all directions of below and above. The components can also be oriented in other directions, and thereby, spatially relative terms can be interpreted according to the orientation.

[0025] The numerical ranges indicated by using the term 'to' herein indicate numerical ranges including the values described before and after the term as the lower limit value and the upper limit value respectively. When multiple values are disclosed for the upper and lower limits of any numerical range, the numerical ranges disclosed herein shall be understood as any numerical range having any one of the multiple lower limit values and any one of the multiple upper limit values as the lower limit value and the upper limit value respectively.

[0026] Hereinafter, a method and system for purifying oily water using a membrane filter device (i.e., a membrane filtration process and system) will be described.

[0027] The membrane filtration process means a process of generating filtered water suitable for ship emission regulation requirements by removing oil sludge and / or suspended solids on raw water (or treated water) produced by a water treatment module (or unit) through a membrane filter and / or a hollow fiber membrane filter. A continuous cleaning operation for the membrane filter device and related piping is required to efficiently perform the membrane filtration process.

[0028] Here, the raw water can include one or a mixture of two or more selected from the group consisting of seawater, fresh water, and oily water.

[0029] The membrane filtration process according to an embodiment of the present invention consists of i) normal operation of membrane filtration equipment and ii) chemical cleaning (Cleaning in place, CIP) for cleaning the membrane filter with chemicals.

[0030] Normal operation consists of a water supply process, a filtration process, a backwashing process, and a drainage process. Here, the backwashing process may be carried out after the filtration process stops and before restarting. Chemical cleaning consists of an operation of injecting chemicals into a cleaning cylinder, a chemical circulation process, a discharge process, a rinsing process, and a drainage process.

[0031] When the membrane filter device is newly provided as filtration process equipment, a normal operation cycle (i.e., a water supply process, a filtration process, a backwashing process, and a drainage process) is preferentially carried out for the stability of normal operation.

[0032] The operating time for each process can be adjusted according to the basic set time and / or design conditions. The operating time for each process is changed from the basic set time according to changes in the water quality of the raw water supplied from the water treatment module and various conditions.

[0033] Hereinafter, the processes constituting the membrane filtration system will be specifically described with reference to the drawings.

[0034] FIG. 1 is a drawing for explaining a method of performing a water supply (Filing) process according to an embodiment of the present invention.

[0035] The water supply process means a 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).

[0036] Specifically, the WTU raw water supply valve connected to the WTU 10 may be opened with the back-flushing pump (32) open. That is, the WTU (10) opens the valve connected to the tank 13 storing the raw water and operates the water supply pump (15) connected to the tank (13), so that raw water is supplied to one or more membrane filter devices (100, 200) included in the piping and the filtering module (20) connected to the WTU 10. At this time, the WTU (10) can operate the water supply pump (15) for a preset time (for example, 20 seconds).

[0037] In the water supply process, the valves at the outlets of the membrane filter devices and other valves may all be in a closed state.

[0038] FIG. 2 is a drawing for explaining a method of performing a filtration process according to an embodiment of the present invention.

[0039] The filtration process means a 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 in the raw water.

[0040] As described above, the WTU (10) opens the valve to which the tank (13) containing the raw water is connected, and operates the water supply pump (15) connected to the tank 13, so that the raw water is supplied to one or more membrane filter devices (100, 200) through the pipe (22) connected to the WTU (10).

[0041] Specifically, the filtering module (20) can input the raw water supplied from the WTU (10) into one or more membrane filter devices (100, 200) to obtain filtered water and first condensed water. The particle size of the emulsion contained in the first condensed water may be 0.2 to 8.0 μm. The device can discharge the filtered water through the pipe (or pipe) (24) connected to the first discharge port of one or more membrane filter devices (100, 200).

[0042] At this time, the upper cap located at the upper end of one or more membrane filter devices includes a storage space for collecting the first condensed water. The first condensed water obtained by one or more membrane filter devices (100, 200) can be stored on the storage space. The structure of the membrane filter device will be described with reference to FIGS. 10 and 11a to 11c.

[0043] FIG. 3 is a drawing for explaining a method of performing back-flushing according to an embodiment of the present invention.

[0044] The back-flushing process (or / and the air-drop washing process) is a process of removing contaminants attached to the surface and pores of the membrane filter by supplying fresh water (i.e., back-flushing water) from the secondary membrane to the primary membrane side during the membrane filtration process.

[0045] The backwashing module (30) can supply backwashing water to the filtering module (20) by operating the backwashing pump (32). At this time, the backwashing module (30) can supply bubbles to the backwashing water through the backwashing pump and / or the piping connected thereto.

[0046] In order to efficiently backwash the membrane filter, the backwashing pump (320) can supply backwashing water having a sufficient flow rate to the filtering module (20). The flow rate of the backwashing water supplied to the filtering module (20) by the backwashing module (30) is 3 bar * 3 m 3 / h to 6 bar * 5 m 3 / h in some cases.

[0047] That is, the backwashing water supplied from the backwashing module is input to the first discharge port, and based on the acquisition of the second condensate, one or more first condensates and the second condensate are discharged through the pipe (32) connected to the second discharge port of the membrane filter device (100, 200). The first condensate and the second condensate discharged through the pipe (32) connected to the second discharge port are stored in the EGR drain tank.

[0048] As an example of the present invention, while raw water is supplied from the water treatment module 10 to the filtering module (20), backwashing water is supplied from the backwashing module (30) to the filtering module (20), and while the filtered water is discharged through the first discharge port, the first condensate and the second condensate are discharged through the second discharge port. Here, the particle size of the emulsion contained in the second condensate may be 0.2 to 8.0 μm.

[0049] That is, the filtering process described with reference to FIG. 2 and the backwashing process described with reference to FIG. 3 are performed simultaneously.

[0050] FIG. 4 is a diagram for explaining a method of performing a drain process according to an embodiment of the present invention.

[0051] When the backwashing process described with reference to FIG. 3 is completed, the filtering module (20) drains the first condensate and the second condensate by opening a discharge valve connected to a vent and a second outlet.

[0052] FIG. 5 is a diagram for explaining a chemical cleaning process according to an embodiment of the present invention.

[0053] The chemical cleaning (CIP) process means a process of cleaning a membrane filter with chemical components when the differential pressure approaches the operating limit differential pressure (for example, 1.0 bar, 100 kPa) even after backwashing due to the long-term operation of the membrane filter device or the change in the quality of the WTU treated water.

[0054] Since the tendency of the differential pressure increase varies depending on the state of the membrane filter, the quality of the WTU treated water, etc., the chemical cleaning cycle may increase or decrease depending on the situation. However, the differential pressure should not operate above the operating limit differential pressure, and if the chemical cleaning cycle increases, it may be determined that the membrane is damaged.

[0055] The system according to the present invention includes a control device that controls the WTU (10), the filtering module (20), the backwashing module (30), and the CIP module (40). If it is determined that the period in which the CIP module performs chemical cleaning is less than the critical period, the control device can transmit a message requesting replacement of the membrane filter in one or more membrane filter devices (100, 200) to the terminal device used by the system administrator.

[0056] As an example of the present invention, after the first condensate (i.e., the condensate generated through the filtration process) and the second condensate (i.e., the condensate generated through the backwashing process) are discharged through the second outlet of the membrane filter device, based on the pressure in one or more membrane filter devices (100, 200) being within a critical range, the CIP module (40) can perform chemical cleaning on one or more membrane filter devices.

[0057] Additionally or alternatively, the CIP module (40) can perform chemical cleaning on one or more membrane filter devices (100, 200) at predefined intervals. Here, the oily water cleaning liquid composition for membrane filters used in chemical cleaning contains a chemical cleaning liquid and water.

[0058] The chemical cleaning liquid according to the present invention contains a wetting agent, a stabilizer, a surfactant, an emulsifying film remover, and purified water.

[0059] Wetting agent The wetting agent according to the present invention can not only realize the high detergency and emulsifying power of the cleaning liquid composition, but also contribute to the good mixing of contaminants attached to the surface of the membrane filter with water. The wetting agent according to another aspect of the present invention can effectively prevent the excessive generation of foam in the oily water cleaning liquid composition for membrane filters.

[0060] The content of the wetting agent according to the present invention may be 6 - 14 wt%, 7 - 13 wt%, 8 - 12 wt%, 9 - 11 wt%, or 10 - 11 wt% based on the total weight of the chemical cleaning liquid. Specifically, when the content of the wetting agent is less than the numerical range, the contaminants attached to the surface of the membrane filter may not mix well with water and the chemical cleaning function may not proceed effectively. When exceeding the numerical range, the fluidity of the cleaning liquid composition may be reduced and the cleaning efficiency may decrease.

[0061] The wetting agent according to the present invention can contain sulfonate. Specifically, compared with other types of wetting agents, the sulfonate can not only realize high detergency and emulsifying power, but also further realize the effect that contaminants attached to the surface of the membrane filter mix better with water.

[0062] For example, the sulfonate may be one or a mixture of two or more selected from the group consisting of Sodium xylenesulphonate, Sodium dodecylbenzenesulfonate, and Sodium perfluorooctane sulfonate. However, the technical idea of the present invention is not limited thereto, and any sulfonate that serves as a wetting agent is applicable.

[0063] Stabilizer The stabilizer according to the present invention contributes to the good dispersion of lipophilic contaminants attached to the membrane filter in water. Thereby, the stabilizer can effectively prevent the lipophilic contaminants from being separately separated by further dispersing the lipophilic contaminants in water, and can realize the stabilizing effect of the cleaning liquid composition.

[0064] The stabilizer according to the present invention may be 1 to 9 wt%, 2 to 8 wt%, 3 to 7 wt%, 4 to 6 wt%, or 5 to 6 wt% based on the total weight of the chemical cleaning liquid. Specifically, when the content of the stabilizer is less than the numerical range, there may be a problem that lipophilic contaminants cannot be well dispersed in water and are separated separately from water, and when it exceeds the numerical range, the fluidity of the cleaning liquid composition may decrease and the cleaning efficiency may decrease.

[0065] For example, the stabilizer may be one or a mixture of two or more selected from the group consisting of Sodium tripolyphosphate, Sodium hexametaphosphate, Sodium polymetaphosphate, Disodium pyrophosphate, and Sodium carboxymethylcellulose.

[0066] Surfactant The surfactant according to the present invention can relax the interface where the lipophilic contaminants attached to the membrane filter come into contact with water. As a result, the surface tension at the interface between the lipophilic contaminants and water becomes weaker, and the lipophilic contaminants attached to the membrane filter can be effectively removed.

[0067] The surfactant according to the present invention can include one or more selected from the group consisting of anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants. Specifically, it can include a nonionic surfactant. According to one embodiment of the present invention, by using a nonionic surfactant as the surfactant, not only is it excellent in the cleaning action even at low temperatures, but also the effect of generating less foam in the cleaning liquid composition can be realized.

[0068] For example, the anionic surfactant can include a hydrophilic functional group as a substance having the property that anions generated by dissociation in water are adsorbed on the surface of the aqueous solution to lower the surface tension. Here, the hydrophilic functional group can include any one or more of a carboxyl group, a phosphate group, and a sulfonate group. According to one example, the anionic surfactant may be one or a mixture of two or more selected from the group consisting of lauryl ammonium phosphate, cetyl ammonium phosphate, tetradecyl ammonium phosphate, lauryl ammonium sulfate, cetyl ammonium sulfate, dodecylbenzene ammonium sulfate, ammonium hexadecyl ether sulfate, tridecyl ammonium phosphate, tetradecyl ammonium phosphate, dilauryl ammonium phosphate, dicetyl ammonium phosphate, ditridecyl ammonium phosphate, tetradecyl ammonium sulfate, tridecylbenzene ammonium sulfate, dodecyl ammonium sulfate, hexadecyl ammonium sulfate, and lauryl ammonium carboxylate.

[0069] For example, a cationic surfactant is a substance that has the property of reducing the surface tension by adsorbing cations generated by dissociation in water onto the surface of an aqueous solution. According to one example, the cationic surfactant may be any one selected from the group consisting of stearyl ammonium chloride, stearyl trimonium chloride, distearyl-dimonium chloride, and mixtures thereof.

[0070] For example, the amphoteric surfactant is also a compound that can change to an anionic state, a cationic state, or a nonionic state in an aqueous solution depending on the pH of water. According to one example, the amphoteric surfactant may be one or a mixture of two or more selected from the group consisting of didecyl ethanolamine oxide, dodecyl dimethylamine oxide, tetradecyl dimethylamine oxide, hexadecyl dimethylamine oxide, octadecyl dimethylamine oxide, coco dimethylamine oxide, coco bis(2-hydroxyethyl)amine oxide, dicoco dimethylamine oxide, dicoco ethanolamine oxide, cocoamidopropyl dimethylamine oxide, tallow dimethylamine oxide, tallow diethanolamine oxide, ditallow dimethylamine oxide, ditallow dimethylamine oxide, ditallow diethanolamine oxide, di(hydrogenated tallow)methylamine oxide, tallowylamidopropyl dimethylamine oxide, 9-octadecenoyl dimethylamine oxide, N-coco morpholine N-oxide, coco dimethyl betaine, cocoamidopropyl dimethyl betaine, lauroylamidopropyl dimethyl betaine, cocamphocarboxyglycinate, and N-coco-3-amino-butyrate.

[0071] For example, the nonionic surfactant may be one or a mixture of two 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 alcohol amine, and aryl alcohol amine.

[0072] The content of the surfactant according to the present invention may be 6 to 14% by weight, 7 to 13% by weight, 8 to 12% by weight, 9 to 11% by weight, or 10 to 11% by weight based on the total weight of the chemical cleaning solution. When the content of the surfactant is less than the numerical range, the surface tension at the interface between the lipophilic contaminant and water does not decrease sufficiently, and problems may occur such as the lipophilic contaminants attached to the membrane filter not being effectively removed. When the content exceeds the numerical range, problems such as a decrease in cleaning efficiency may occur.

[0073] Emulsion film remover The emulsion film remover according to one aspect of the present invention can effectively prevent various impurities contained in oily water from being stabilized and forming an emulsion film in the cleaning solution composition, thereby enhancing the cleaning power. The emulsion film remover according to another aspect of the present invention can increase the pH of the cleaning solution composition and effectively separate lipophilic contaminants attached to the surface of the membrane filter together with water.

[0074] The content of the emulsified 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. When the content of the emulsified film remover is less than the numerical range, problems such as excessive increase of the emulsified film containing impurities in the oily water and decrease of the cleaning power may occur, and when it exceeds the numerical range, problems such as decrease of the cleaning effect may occur.

[0075] For example, the emulsified film remover may be any one selected from the group consisting of sodium metasilicate pentahydrate, sodium metasilicate nonahydrate, and mixtures thereof.

[0076] Purified water The purified water according to the present invention serves as a solvent for dissolving various components contained in the chemical cleaning solution and can dilute the substance to be cleaned.

[0077] The content of the purified water according to the present invention may be the remaining content excluding the above-described composition based on the total weight of the chemical cleaning solution. 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. When the content of the purified water is less than the numerical range, problems such as poor dissolution of various substances contained in the chemical cleaning solution may occur, and when it exceeds the numerical range, problems such as decrease of the cleaning power against the lipophilic contaminants attached to the surface of the membrane filter may occur.

[0078] Cleaning liquid 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 numerical range, the chemical cleaning solution can be effectively dispersed in the water to achieve an excellent cleaning effect. The chemical used for chemical cleaning is a 10% MCL-3000H solution, and a solution prepared by mixing with fresh water is used in the chemical circulation process.

[0079] The method for producing the mixed solution includes the steps of injecting fresh water (41) into the chemical cleaning solution storage tank (43), injecting chemicals (42) into the chemical cleaning solution storage tank (43), and operating the chemical cleaning pump (44) in the circulation mode in the tank to produce the mixed solution. At this time, the volume ratio of fresh water (41) to chemicals (42) in the mixed solution may be 9:1 (v / v).

[0080] Figure 6 is a diagram for explaining the chemical circulation process according to an embodiment of the present invention.

[0081] The chemical circulation process means the process of circulating the chemical cleaning solution (i.e., the mixed solution of fresh water and chemicals) through the membrane filter.

[0082] The CIP circulation valve and the chemical cleaning inflow valve may be in an open state. The CIP module (40) can operate the chemical cleaning solution supply pump (44) to inject the chemical cleaning solution into the filtering module (20). The membrane filter can be cleaned with the chemical cleaning solution for a certain period of time (e.g., 40 minutes).

[0083] As an example, when it is determined that bubbles have occurred in the CIP tank, the CIP module (40) may add a predetermined defoaming agent to the CIP tank.

[0084] Figure 7 is a diagram for explaining the chemical discharge process according to an embodiment of the present invention.

[0085] When the chemical circulation process is completed, the chemical cleaning solution may be recovered into the chemical cleaning solution tank (43) for reuse. If it is difficult to reuse because the contamination level of the chemical cleaning solution is equal to or higher than a predefined value, the CIP module can send the chemical cleaning solution to the chemical waste tank (45) by operating the chemical cleaning solution discharge valve.

[0086] FIG. 8 is a diagram for explaining the Rinse process according to an embodiment of the present invention.

[0087] The Rinse process means discharging contaminants and chemical cleaning chemicals separated on the surface of the membrane filter by chemical cleaning solution circulation and bubbles from the filtering module and the pipes connected thereto, and washing the filtering module and the pipes connected thereto with fresh water.

[0088] The cleaning valve connected to the backwashing module (30) is opened, and the backwashing module (30) can wash the filtering module and the pipes connected thereto for a certain period (e.g., 60 seconds) by injecting fresh water into the filtering module (20). The cleaning water discharged in the Rinse process can be transferred to the chemical waste tank (45).

[0089] Once the Rinse process is completed, the chemical cleaning procedure ends, and the normal operation process can proceed again. If the contamination level or differential pressure of the membrane filter is within the critical range even after the CIP process, a manual chemical cleaning process is performed.

[0090] FIG. 9 is a diagram for explaining the Drain process according to an embodiment of the present invention.

[0091] When the chemical discharge process is completed, the vent and drain valves are opened, and chemical residues can be discharged through the outlet of the membrane filter (e.g., the second outlet).

[0092] FIG. 10 is a diagram for explaining the structure of a unit membrane filter element according to an embodiment of the present invention.

[0093] The membrane filter device means a device combining one or more unit membrane filter elements. The unit membrane filter element means a structure in which another component is attached to a unit filter housing (110). For the convenience of explaining the present invention, in FIG. 1, it is assumed that there is one unit membrane filter element in the membrane filter device.

[0094] A membrane filter device (100) according to an embodiment of the present invention includes a filter housing, one or more membrane filters (120-1, 120-2), an upper cap (130), and a lower cap (140).

[0095] The filter housing (110) may include a stainless steel material. When the filter housing (110) is made of stainless steel, the weight of the filter housing (110) can be reduced. Also, it is possible to prevent the filter housing from bending or burning due to a fire or heat inside the ship. If the material of the filter housing is carbon steel, an increase in thickness considering the corrosion margin is required, and difficulties in installation work and separation work may occur due to an increase in the weight of the filter housing.

[0096] One or more membrane filters (120-1, 120-2) can be arranged inside the filter housing. As an example, one or more membrane filters (120-1, 120-2) are detachably coupled inside the filter housing.

[0097] Conventionally, in the case of a method of fixing a membrane filter to the upper end of a filter housing, contaminants of the membrane filter are concentrated on the upper part of the filter housing, and there is a problem that even if a discharge port is provided around the concentrated area (for example, the side surface), the discharge of contaminants is not effectively performed due to the aggregability of the contaminants.

[0098] According to one aspect of the present invention, by detachably coupling one or more membrane filters inside the filter housing, the discharge efficiency of contaminants can be further improved.

[0099] FIG. 1 illustrates a case where two membrane filters (120-1, 120-2) are provided / attached inside a filtering housing (110), but the present invention is not limited thereto, and one or more membrane filters may be provided / attached inside the filtering housing (110).

[0100] When the contamination of the membrane filters (120-1, 120-2) is serious or the differential pressure inside the membrane filters (120-1, 120-2) increases, the membrane filters (120-1, 120-2) can be easily detached from the filter housing and replaced.

[0101] According to one embodiment of the present invention, the pore size of the membrane inside the membrane filters (120-1, 120-2) may be 0.05 to 0.25 μm, 0.07 to 0.24 μm, 0.08 to 20 μm, or 0.10 to 0.20 μm. When the pore size of the membrane satisfies the above numerical range, the oil particles contained in the raw water can be effectively filtered by the internal pores of the membrane filter.

[0102] According to another embodiment of the present invention, the membrane filters (120-1, 120-2) include pressurized hollow fibers. According to one aspect of the present invention, by using hollow fibers with a relatively large surface area as the membrane filter, contaminants, oil, etc. contained in the raw water can be filtered more effectively.

[0103] At the lower end (or lower region) of the filter housing (110), a lower cap (130) is attached through a first housing coupling member. The lower cap (130) includes an inlet (140) into which raw water is injected and an air supply connection member (135).

[0104] Here, the raw water may contain one or more mixtures selected from the group consisting of sea water, fresh water, and oily water. That is, the user can inject raw water into the inlet (140) in order to filter various contaminants contained in the raw water through the membrane filter device 100.

[0105] At the upper end (or upper region) of the filter housing (110), an upper cap (150) is attached through a second housing coupling member. The upper cap (150) includes a first discharge port (160), a second discharge port (170), and / or a storage space (for example, a specific space (180) in the upper cap 150) for storing condensed water.

[0106] Specifically, the internal space of the upper cap (150) and the upper space of the filter housing (110) are defined as one 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 another substance on the upper space of the filter housing (110) can move into the internal space of the upper cap (150).

[0107] Thereby, the condensed water that has passed through one or more membrane filters (120-1, 120-2) in the filter housing can be accommodated in the storage space (180) for storing condensed water.

[0108] Additionally or alternatively, the upper cap (150) may include a first storage member for storing another condensed water, and the filtering housing 110 may also include a second storage member for storing another condensed water.

[0109] As shown in FIG. 10, for example, the first discharge port (160) and the second discharge port 170 may be arranged in the side region of the upper cap (180).

[0110] The lower cap (130) and the filter housing (110) can be detached by the first housing coupling member. And the upper cap (150) and the filter housing (110) can be detached by the second housing coupling member.

[0111] That is, the filtering housing (110) can be easily detached from the lower cap (130) and the lower cap (150). As a result, a technical effect is derived that the filtering housing (110) can be easily separated and replaced even in a narrow area and limited height inside the ship.

[0112] The process in which various filtered water and condensed water are discharged through the first discharge port (160), the second discharge port (170), and the storage member 180 will be specifically described with reference to FIG. 10.

[0113] For example, the length from the central region of the second discharge port (170) to the injection port (140) is 1816 mm, the length from the upper end of the upper cap (150) to the injection port (140) is 1879 mm, and the length from the upper end of the first discharge port (160) to the injection port (140) is 1886 mm.

[0114] However, this is only an example, and the length and width between the components of the membrane filter device (100) may vary.

[0115] FIGS. 11a to 11c are diagrams for explaining the structures of the upper cap and the lower cap according to an embodiment of the present invention.

[0116] As described with reference to FIG. 10, a first discharge port and a second discharge port can be coupled / attached to the upper cap, and an inlet port can be coupled / attached to the lower cap.

[0117] As shown in FIG. 11a, a first connecting member (180) is configured to couple / attach each of the first discharge port and the second discharge port to an external pipe, and a second connecting member (190) for coupling / attaching the inlet port to the external pipe is configured within the membrane filter device.

[0118] FIG. 11b shows the structure of the first connecting member (180) for coupling / attaching each of the first discharge port and the second discharge port to an external pipe.

[0119] A gasket can be coupled / attached to the first discharge port and / or the second discharge port. Through the gasket, the first discharge port and / or the second discharge port and the first connecting member (180) are connected. And the filtered water and / or condensed water discharged through the first discharge port and / or the second discharge port may be discharged through the pipe. The numerical values shown in FIG. 2(b) are only examples and may be determined as other values.

[0120] FIG. 11c shows the structure of the second connecting member (190) for coupling / attaching each of the inlet ports (i.e., the membrane modules) to an external pipe.

[0121] A gasket may be coupled / attached to the inlet port. Through the gasket, the inlet port and the second connecting member (190) are connected. And the raw water injected through the pipe can be transmitted into the membrane filter device through the inlet port. The numerical values shown in FIG. 2(c) are only examples and may be determined as other values.

[0122] 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. Also, 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).

[0123] According to yet another embodiment of the present invention, a ship exhaust gas water treatment system including the above system can be provided. Therefore, the claimed subject matter of the present invention can also be changed from a system to a ship exhaust gas water treatment system. According to one aspect of the present invention, when the above system is applied to a ship exhaust gas water treatment system, oil particles can be effectively filtered from raw water, and treated water meeting the discharge standards can be discharged.

[0124] As described above, the disclosed embodiments have been described with reference to the accompanying drawings. Those having ordinary knowledge in the technical field to which the present invention pertains will understand that the present invention can be implemented in the disclosed embodiments or in different forms without changing the technical idea or essential features of the present invention. The disclosed embodiments are illustrative and should not be construed as limiting.

Description of Reference Numerals

[0125] 10: Water treatment module 20: Filtering module 30: Backwashing module 40: CIP module 100: Membrane filter device 110: Filtering housing 120-1, 120-2: Membrane filter 130: Lower cap 135: Air supply connecting member 140: Inlet 150: Upper cap 160: First outlet 170: Second outlet 180: Storage space

Claims

1. In a system A water treatment module for supplying raw water; A filtering module including one or more membrane filter devices receiving the supply of raw water from the water treatment module; A back-flushing module for supplying back-flushing water to the filtering module; A chemical in place (CIP) module for performing chemical cleaning on the one or more membrane filters using a chemical cleaning solution contained in a chemical cleaning solution tank; and Including a control device for controlling the water treatment module, the filtering module, the back-flushing module, and the CIP module, The filtering module is: Based on inputting the raw water supplied from the water treatment module into the one or more membrane filter devices to obtain filtered water and first condensate, discharging the filtered water through a first discharge port of the one or more membrane filter devices, and storing the first condensate in a storage member included in an upper cap of the one or more membrane filters, Based on inputting the back-flushing water supplied from the back-flushing module into the first discharge port to back-flush the one or more membrane filters to obtain second condensate, discharging the first condensate stored in the storage member and the second condensate through a second discharge port of the membrane filter device, The control device is: When it is determined that the period during which the CIP module performs chemical cleaning on the one or more membrane filters is less than a critical period, transmitting a message requesting replacement of the membrane filters in the one or more membrane filter devices to a terminal device managing the system, The CIP module is: Based on the contamination degree of the chemical cleaning solution used in the chemical cleaning being less than a predefined value, recovering the chemical cleaning solution into the chemical cleaning solution tank, Based on the contamination degree of the chemical cleaning solution being equal to or greater than the predefined value, transferring the chemical cleaning solution to a chemical waste tank, The chemical cleaning solution is: A system including, based on the total weight of the chemical cleaning solution, 6 to 14% by weight of a wetting agent, 1 to 9% by weight of a stabilizer, 6 to 14% by weight of a surfactant, 0.5 to 1.5% by weight of an emulsifying film remover, and the remaining purified water.

2. The system according to claim 1, wherein the particle size of the emulsion contained in at least one of the first condensed water and the second condensed water is 0.2 to 8.0 μm.

3. The flow rate of the backwashing water supplied by the backwashing module is 3 bar * 3 m 3 / h to 6 bar * 5 m 3 / h. The system according to claim 1

4. The system according to claim 1, wherein the backwashing module includes a pipe for supplying bubbles to the backwashing water.

5. After discharging the first condensed water and the second condensed water through the second discharge port of the membrane filter device, based on the pressure in the one or more membrane filter devices being a value within a critical range, the CIP module performs chemical cleaning on the one or more membrane filter devices. The system according to claim 1.

6. The system according to any one of claims 1 to 5, wherein the CIP module performs chemical cleaning on the one or more membrane filter devices at predefined intervals.

Images