Reverse osmosis membrane cleaning system

Abstract

The utility model provides a reverse osmosis membrane cleaning system which comprises at least one cleaning pipeline, the cleaning pipeline comprises a dosing box, a dosing pump and a membrane component which are connected end to end, the dosing box is configured to contain and mix a target solution, and the dosing pump is configured to obtain and convey the target solution from the dosing box; the membrane component comprises a membrane element and a membrane shell, and the membrane shell is used for accommodating the membrane element and a target solution; the cleaning system further comprises a valve assembly, and the valve assembly is opened when the membrane element is cleaned, so that a target solution circulates among the dosing tank, the dosing pump and the membrane assembly; the target solution comprises a cleaning agent and a cleaning solution, the cleaning agent is used for dissolving and removing pollutants on the membrane element, and the cleaning solution is used for washing the dosing box and the membrane element. According to the cleaning system, online cleaning can be carried out on stably-operated equipment of the reverse osmosis membrane system, the cleaning process is simple, the cleaning effect of offline cleaning can be achieved, labor consumption is reduced, and the online cleaning cost is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to water treatment technical field especially relates to a kind of reverse osmosis membrane cleaning systems. BACKGROUND

[0002] During the operation of reverse osmosis membrane, membrane element can be influenced by particulate matter, organic matter, microorganism and other substances that cannot permeate reverse osmosis membrane in the influent, and membrane pollution is formed. According to the types of substances in membrane pollution, pollutants can be divided into organic pollution (protein, humic substance, etc.), inorganic pollution (calcium carbonate, calcium sulfate and metal oxide precipitate, etc.), biological pollution (extracellular polymeric substance, etc.) and colloidal pollution (aluminum silicate, excess scale inhibitor, etc.). The formation process of reverse osmosis membrane pollution is usually gradual, and early control of membrane pollution can effectively prolong the service life of membrane element. Therefore, regular cleaning and maintenance during the operation of reverse osmosis membrane is crucial.

[0003] Reverse osmosis membrane cleaning includes online cleaning and offline cleaning. Online cleaning is cleaning without taking membrane element out of the pressure vessel, which is simple and convenient, but not thorough, and is usually used for daily maintenance with light pollution. Offline cleaning is cleaning by taking membrane element out of reverse osmosis equipment and putting it into a special cleaning equipment, which has obvious cleaning effect, but the process of taking out is complex and requires special operators. UTILITY MODEL CONTENT

[0004] The utility model aims to provide a kind of reverse osmosis membrane cleaning system, the cleaning system can be on-line cleaning on the equipment of the stable operation of reverse osmosis membrane system, and the cleaning process is simple, which can reduce the labor consumption when reverse osmosis membrane is offline cleaned, and reduce the cost of offline cleaning.

[0005] To achieve the above-mentioned purpose, the utility model provides a kind of reverse osmosis membrane cleaning system, including at least one cleaning pipeline, the cleaning pipeline includes the medicine adding tank, dosing pump and membrane assembly connected at the head and tail, the medicine adding tank is configured to contain and mix target solution, the dosing pump is configured to obtain and transport the target solution from the medicine adding tank;The membrane assembly includes membrane element and membrane shell, the membrane shell is used to contain the membrane element and the target solution;The cleaning system further includes valve assembly, at least part of the valve assembly is used to open when cleaning the membrane element, to make the target solution circulate between the medicine adding tank, the dosing pump and the membrane assembly.

[0006] The target solution includes cleaning agent and cleaning liquid, the cleaning agent is used to dissolve and remove pollutants on the membrane element, and the cleaning liquid is used to flush the medicine adding tank and the membrane element.

[0007] Optionally, each of the cleaning pipelines further comprises a filter and a cleaning pump connected in sequence, the filter and the cleaning pump are arranged between the dosing pump and the membrane assembly; wherein the filter is in communication with the dosing pump, and the cleaning pump is in communication with the membrane assembly; the filter is configured to remove particulate matters in the cleaning agent, and the cleaning pump is configured to obtain the target solution from the filter and deliver the target solution to the membrane assembly.

[0008] Optionally, the number of the cleaning pumps and the number of the membrane assemblies are both plural, and each of the cleaning pumps is connected with a corresponding one of the membrane assemblies and configured to provide the target solution to the corresponding one of the membrane assemblies.

[0009] Optionally, the number of the cleaning pipelines is at least two, and each of the cleaning pipelines comprises the dosing tank, the dosing pump, the filter, the cleaning pump and the membrane assembly connected in sequence.

[0010] Optionally, each of the cleaning pipelines comprises a plurality of the cleaning pumps and a plurality of the membrane assemblies, each of the membrane assemblies is in communication with a corresponding one of the cleaning pumps, and all of the cleaning pumps on two of the cleaning pipelines are respectively connected with the filter on each of the cleaning pipelines.

[0011] Optionally, the valve assembly comprises a first valve, and the first valve is arranged between the dosing tank and the dosing pump.

[0012] Optionally, the valve assembly further comprises a second valve, and the second valve is arranged between the cleaning pump and the filter.

[0013] Optionally, the number of the cleaning pumps and the number of the second valves are both plural, and each of the cleaning pumps is in communication with the filter through a corresponding one of the second valves.

[0014] Optionally, the valve assembly further comprises a third valve, and the third valve is arranged between the cleaning pump and the membrane assembly.

[0015] Optionally, the valve assembly further comprises a fourth valve and a fifth valve, the membrane assembly has a concentrated water outlet and a product water outlet, the fourth valve is arranged between the concentrated water outlet of the membrane assembly and the dosing tank, and the fifth valve is arranged between the product water outlet of the membrane assembly and the dosing tank.

[0016] Optionally, the reverse osmosis membrane cleaning system further comprises a concentrated water pool and a product water pool, the valve assembly further comprises a sixth valve and a seventh valve, the sixth valve is arranged between the concentrated water outlet of the membrane assembly and the concentrated water pool, and the seventh valve is arranged between the product water outlet of the membrane assembly and the product water pool.

[0017] Optionally, the valve assembly further comprises an eighth valve, which is arranged between the water production tank and the chemical adding tank, and is used to supply the cleaning liquid to the chemical adding tank.

[0018] Optionally, the cleaning pipeline is provided with a plurality of control points, which comprise one or more of a pressure control point, a temperature control point, a flow control point, a PH detection point and a conductivity detection point.

[0019] Optionally, the temperature control point and / or the PH detection point are arranged on the chemical adding tank,

[0020] and / or, the pressure control point is arranged on at least one side of the filter,

[0021] and / or, at least one of the flow control point, the pressure control point and the conductivity detection point is arranged between the cleaning pump and the membrane assembly,

[0022] and / or, at least one of the flow control point, the pressure control point, the PH detection point and the conductivity detection point is arranged at the concentrated water outlet and the water production outlet of the membrane assembly.

[0023] Optionally, the reverse osmosis membrane cleaning system further comprises a detection device and a control device, wherein the detection device comprises at least one of a pressure monitoring instrument, a PH detection instrument, a temperature monitoring instrument, a flow monitoring instrument and a conductivity detection instrument; and the pressure monitoring instrument, the PH detection instrument, the temperature monitoring instrument, the flow monitoring instrument or the conductivity detection instrument are connected with the control device.

[0024] The pressure monitoring instrument is used to monitor the pressure value at the pressure detection point, the PH detection instrument is used to detect the PH value at the PH detection point, the temperature monitoring instrument is used to monitor the temperature value at the temperature control point, the flow monitoring instrument is used to monitor the flow value at the flow control point, and the conductivity detection instrument is used to detect the conductivity at the conductivity detection point.

[0025] The reverse osmosis membrane cleaning system provided by the utility model can perform online cleaning on the equipment of the stable operation of the reverse osmosis membrane system, that is, the system can perform online cleaning on the membrane element without disassembling the membrane element, and can achieve the cleaning effect of offline cleaning. The cleaning process is simple, the disassembly process of offline cleaning of the membrane element is avoided, the consumption of labor during the cleaning of the reverse osmosis membrane is reduced, and the cost of online cleaning is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1The utility model discloses a preferred embodiment of reverse osmosis membrane cleaning system's process flow chart, wherein, the reverse osmosis membrane cleaning system includes valve subassembly.

[0027] Figure 2 The utility model discloses a preferred embodiment of reverse osmosis membrane cleaning system's process flow chart, wherein, the reverse osmosis membrane cleaning system includes control subassembly.

[0028] In the drawing,

[0029] Medicated tank 1;Medicated pump 2;Membrane subassembly 3;Concentrated water outlet 31;Water production outlet 32;Filtering piece 4;Cleaning pump 5;First valve 61;Second valve 62;Third valve 63;Fourth valve 64;Fifth valve 65;Sixth valve 66;Seventh valve 67;Eighth valve 68;Ninth valve 69;Concentrated water pool 7;Water production pool 8;Pretreatment water pool 9. DETAILED DESCRIPTION

[0030] The utility model will be explained further in detail below in combination with the drawings and specific embodiment. According to the following explanation, the advantages and characteristics of the utility model will be more clear. It is stated that, the drawings all adopt very simplified form and all use non-precise proportion, only to facilitate, clear and assist the purpose of explaining the embodiment of the utility model.

[0031] The orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated mechanisms or elements must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model.

[0032] In the utility model, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "fixing" and the like should be understood broadly, for example, can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection or communication with each other; can be directly connected, or connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise explicitly limited. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0033] As used in this specification, the terms "first", "second", or the like, are intended to

[0034] The utility model will be explained in detail below in combination with the drawings and preferred embodiments. In the case of no conflict, the following embodiments and features in the embodiments can be supplemented or combined with each other.

[0035] Referring to Figure 1 As shown in the drawings, the utility model provides a kind of reverse osmosis membrane cleaning system, including at least one cleaning pipeline, cleaning pipeline includes the dosing tank 1 of head and tail connection, dosing pump 2 and membrane assembly 3, namely the one end of dosing tank 1 and the one end of dosing pump 2 are communicated, the other end of dosing pump 2 and the one end of membrane assembly 2 are communicated, the other end of membrane assembly 3 and the other end of dosing tank 1 are communicated.Dosing tank 1 is configured to accommodate and mix target solution, dosing pump 2 is configured to obtain and transport target solution from dosing tank 1.Membrane assembly 3 includes membrane element and membrane shell (not shown), and the membrane shell is used to accommodate membrane element and target solution.The cleaning system further includes valve assembly, at least part of the valve assembly is used to open when cleaning membrane element, so that target solution circulates between dosing tank 1, dosing pump 2 and membrane assembly 3.

[0036] Further, the target solution includes cleaning agent and cleaning liquid, the cleaning agent is used to dissolve and remove the pollutants on the membrane element, and the cleaning liquid is used to flush the dosing tank 1 and the membrane element 3.

[0037] It should be noted that the membrane element is used to remove the pollutants such as dissolved salts, colloids or organic matters in the incoming water. Specifically, the pollutants in the membrane element include but are not limited to organic pollution (protein, humus, etc.), inorganic pollution (calcium carbonate, calcium sulfate and metal oxide precipitate, etc.), biological pollution (extracellular polymeric substance, etc.) and colloidal pollution (aluminum silicate, excess scale inhibitor, etc.).

[0038] It should be understood that the cleaning agent includes but is not limited to acidic, alkaline or non-oxidizing cleaning agent required during the cleaning process of the membrane element, and the cleaning liquid includes but is not limited to reverse osmosis product water or pure water. It should be understood that the dosing tank 1 is configured to provide the cleaning agent used in the online cleaning process for the membrane assembly 3, and to provide a place for the configuration of multiple cleaning agents. The membrane assembly 3 here is a reverse osmosis membrane stable operation device, and the membrane element is placed in the membrane shell, which is used to filter the incoming water. Generally, the membrane shell used by the membrane assembly 3 can be a reverse osmosis membrane shell commonly used in industrial wastewater treatment projects, and the size can be selected as 80 mm * 40 mm or 40 mm * 40 mm.

[0039] In actual work, one or more cleaning agents can be added into the dosing tank 1. When the cleaning agents are multiple, the dosing tank 1 can mix the cleaning agents. After the cleaning agents are added into the dosing tank 1, the dosing pump 2 can be opened, and the cleaning agents can flow in the membrane assembly 3, the dosing tank 1 and the dosing pump 2, so as to clean the membrane element.

[0040] The reverse osmosis membrane cleaning system provided by the utility model can perform online cleaning on the equipment of the stable operation of the reverse osmosis membrane system, that is, the system can perform online cleaning on the membrane element without disassembling the membrane element, and can achieve the cleaning effect of offline cleaning; the cleaning process is simple, the disassembling process of offline cleaning of the membrane element is avoided, the consumption of manpower during the cleaning of the reverse osmosis membrane is reduced, and the cost of online cleaning is reduced.

[0041] Continuing to refer to Figure 1 Each cleaning pipeline further comprises a filter 4 and a cleaning pump 5 connected in sequence, and the filter 4 and the cleaning pump 5 are arranged between the dosing pump 2 and the membrane assembly 3. The filter 4 is in communication with the dosing pump 2, and the cleaning pump 5 is in communication with the membrane assembly 3. The filter 4 is configured to remove particulate matters in the cleaning agent, and the cleaning pump 5 is configured to obtain the target solution from the filter 4 and used to deliver the target solution to the membrane assembly 3, that is, the cleaning pump 5 is used to deliver the target solution filtered by the filter 4 to the membrane assembly 3. The dosing pump 2 is configured to deliver the target solution in the dosing tank 1 to the filter 4.

[0042] Specifically, after the cleaning agent (or cleaning liquid) is added into the dosing tank 1, the dosing pump 2 and the cleaning pump 5 are opened, the cleaning agent (or cleaning liquid) is delivered into the filter 4 under the driving of the dosing pump 2, and the cleaning agent can remove large particulate pollutants in the filter 4. The filtered cleaning agent (or cleaning liquid) is delivered into the membrane assembly 3 under the driving of the cleaning pump 5, so as to clean (or flush) the membrane assembly 3. Subsequently, the cleaning agent (or cleaning liquid) can flow back from the membrane assembly 3 to the dosing tank 1, and the above process is repeated.

[0043] It should be understood that the cleaning agent (or cleaning liquid) flowing back from the membrane assembly 3 to the dosing tank 1 can further comprise one or more pollutants peeled from the membrane element.

[0044] In a preferred example, the dosing pump 2 and the cleaning pump 5 are centrifugal pumps. In another preferred example, the dosing pump 2 and the cleaning pump 5 can also be other types of pump devices.

[0045] Preferably, the dosing tank 1 is provided with a stirring device (not shown) to uniformly mix the cleaning agent.

[0046] The application does not limit the type of filter 4. In a specific example, the filter 4 can be provided as a security filter, which can be used to remove large-particle contaminants in the cleaning agent. In another specific example, the filter 4 can also be provided as other types of filters as needed.

[0047] The application does not limit the material of the security filter. The security filter is preferably made of high-temperature-resistant material, for example, the security filter can be made of polypropylene or polyester high-temperature-resistant material, but is not limited thereto. The pore size of the security filter can be selected as 5um.

[0048] In a preferred embodiment, in each cleaning pipeline, the number of cleaning pumps 5 and the number of membrane assemblies 3 are both multiple, and the number of cleaning pumps 5 is preferably the same as the number of membrane assemblies 3. The cleaning pump 5 is configured to be connected with a corresponding membrane assembly 3, at this time, the cleaning pump 5 corresponds to the membrane assembly 3 one by one, and the cleaning pump 5 is used to provide the target solution to the corresponding membrane assembly 3. In this way, the reverse osmosis membrane cleaning system can clean different membrane elements respectively, so as to improve the cleaning efficiency of the membrane assembly 3.

[0049] In this scheme, each cleaning pipeline includes a filter 4, the number of cleaning pumps 5 and the number of membrane assemblies 3 are both multiple, and all cleaning pumps 5 are in communication with the filter 4, at this time, the dosing tank 1 can provide the target solution to the multiple membrane assemblies 3 through the filter 4.

[0050] Referring to Figure 1 In a preferred embodiment, the reverse osmosis membrane cleaning system includes at least two cleaning pipelines, each cleaning pipeline includes a dosing tank 1, a dosing pump 2, a filter 4, a cleaning pump 5 and a membrane assembly 3 connected in series. In this way, multiple membrane elements can be synchronously and independently cleaned through multiple cleaning pipelines, so as to improve the cleaning efficiency and meet the different cleaning requirements of multiple membrane elements. For example, when the membrane elements are multiple, different membrane elements can be synchronously cleaned for daily online cleaning and deep online cleaning, so as to meet the diversified cleaning requirements of the membrane elements.

[0051] It should be noted that the reverse osmosis membrane cleaning system can not only clean the membrane elements for daily online cleaning, but also can clean the reverse osmosis membrane for deep online cleaning. The difference between daily online cleaning and deep online cleaning lies in the cleaning time, cleaning agent or cleaning steps.

[0052] It should be further noted that the number of cleaning pipelines in the reverse osmosis membrane cleaning system can be set and adjusted according to the number of membrane elements to be cleaned. The application does not limit the number of cleaning pipelines in the cleaning system, and the number of cleaning pipelines can be set as 1, 2, 3 or more as needed.

[0053] Referring to Figure 1As shown, in the preferred example, the number of cleaning pipelines is two, each cleaning pipeline includes a plurality of cleaning pumps 5 and a plurality of membrane assemblies 3, each membrane assembly 3 is communicated with a corresponding cleaning pump 5. All cleaning pumps 5 on the two cleaning pipelines are respectively connected with the filter 4 on each cleaning pipeline, that is, all cleaning pumps 5 on each cleaning pipeline are respectively communicated with the filter 4 on the first cleaning pipeline and the filter 4 on the second cleaning pipeline.

[0054] In this way, the filter 4 on the two cleaning pipelines can be communicated with all the membrane assemblies 3. When multiple membrane assemblies 3 need to be cleaned, two membrane assemblies 3 can be respectively communicated with different filters 4, and the two cleaning pipelines are opened at the same time, at this time, the two cleaning pipelines can work independently and realize the synchronous cleaning of the two groups of membrane assemblies 3.

[0055] In the preferred embodiment, the reverse osmosis membrane cleaning system has a daily online cleaning pipeline and a deep online cleaning pipeline, different membrane assemblies 3 can be synchronously subjected to daily online cleaning and deep online cleaning through the two cleaning pipelines, for example, one membrane element can be subjected to deep online cleaning soaking while another membrane element is synchronously subjected to online cleaning operation in the daily operation process. Continue to refer to Figure 1 The valve assembly includes a first valve 61, which is arranged between the dosing tank 1 and the dosing pump 2 to control the on-off between the dosing tank 1 and the dosing pump 2.

[0056] Further, the valve assembly further includes a second valve 62, which is arranged between the cleaning pump 5 and the filter 4 to control the on-off between the filter 4 and the cleaning pump 5.

[0057] In the optional example, in each cleaning pipeline, the second valve 62 is a throttle valve, the number of cleaning pumps 5 and the number of second valves 62 are both multiple, and the number of second valves 62 is preferably the same as the number of cleaning pumps 5, each cleaning pump 5 is communicated with the filter 4 through a corresponding second valve 62. In this way, the communication of multiple membrane assemblies 3 and one filter 4 can be realized. In actual use, the second valve 62 between the target cleaning pump 5 and the filter 4 can be opened, and the second valve 62 between the other cleaning pump 5 and the filter 4 can be closed, thereby realizing the communication of the cleaning pump 5 and the predetermined membrane assembly 3.

[0058] Of course, in other optional examples, in each cleaning pipeline, the number of cleaning pumps 5 and the number of second valves 62 are both one, and the cleaning pump 5 is communicated with the filter 4 through the second valve 62.

[0059] In addition, the valve assembly preferably further comprises a third valve 63, which is arranged between each of the cleaning pumps 5 and the membrane assembly 3, i.e. between each of the cleaning pumps 5 and the corresponding membrane assembly 3, to control the on-off connection between the corresponding cleaning pump 5 and the membrane assembly 3.

[0060] Preferably, the valve assembly further comprises a fourth valve 64 and a fifth valve 65, the membrane assembly 3 has a concentrated water outlet 31 and a product water outlet 32, the fourth valve 64 is arranged between the concentrated water outlet 31 of the membrane assembly 3 and the chemical tank 1, and the fifth valve 65 is arranged between the product water outlet 32 of the membrane assembly 3 and the chemical tank 1. In this way, the membrane assembly 3 can be connected to the chemical tank 1, so that the liquid in the membrane assembly 3 can flow back to the chemical tank 1 through the concentrated water outlet 31 and / or the product water outlet 32.

[0061] It should be noted that the concentrated water outlet 31 of the membrane assembly 3 is located at one end of the water inlet pipe of the membrane shell, and the liquid flowing out of the concentrated water outlet 31 is the reverse osmosis concentrated water which has not been filtered by the membrane element. The product water outlet 32 of the membrane assembly 3 is located at one end of the water outlet pipe of the membrane shell, and the liquid flowing out of the product water outlet 32 is the reverse osmosis product water which has been filtered by the membrane element.

[0062] Referring to Figure 1 As shown in the figure, the reverse osmosis membrane cleaning system further comprises a concentrated water tank 7 and a product water tank 8, and the valve assembly further comprises a sixth valve 66 and a seventh valve 67 (i.e. a backflow valve), the sixth valve 66 is arranged between the concentrated water outlet 31 of the membrane assembly 3 and the concentrated water tank 7, and the seventh valve 67 is arranged between the product water outlet 32 of the membrane assembly 3 and the product water tank 8. The concentrated water tank 7 is used to collect the reverse osmosis concentrated water discharged from the concentrated water outlet 31 of the membrane assembly 3, and the product water tank 8 is used to collect the reverse osmosis product water discharged from the product water outlet 32 of the membrane assembly 3.

[0063] When actually cleaning the membrane element, the sixth valve 66 and the seventh valve 67 can be opened before adding the cleaning agent to the chemical tank 1, so that the reverse osmosis concentrated water in the membrane assembly 3 is discharged into the concentrated water tank 7, and the reverse osmosis product water in the membrane assembly 3 is discharged into the product water tank 8.

[0064] More preferably, the valve assembly further comprises an eighth valve 68, which is arranged between the product water tank 8 and the chemical tank 1, and the product water tank 8 is used to provide cleaning liquid (i.e. reverse osmosis product water) to the chemical tank 1.

[0065] Specifically, when flushing the membrane assembly 3, the eighth valve 68 can be opened to allow the reverse osmosis product water in the product water tank 8 to enter the chemical tank 1, and then enter the membrane assembly 3 through the chemical tank 1, so as to flush the membrane element.

[0066] As another preferred example, when the membrane assembly 3 is being cleaned, the dosing tank 1 can also be connected to other water supply devices to add cleaning liquid into the dosing tank 1 through the water supply devices.

[0067] In addition, when the cleaning agent is configured, the eighth valve 68 can be opened to add the reverse osmosis water in the water tank 8 into the dosing tank 1 to configure cleaning agents with different concentrations.

[0068] In addition, the reverse osmosis membrane cleaning system further comprises a pretreatment water tank 9, and the valve assembly further comprises a ninth valve 69 (refer to Figure 1 ), which is arranged between the pretreatment water tank 9 and the membrane assembly 3. The pretreatment water tank 9 is used to provide water to be filtered to the membrane assembly 3 when the membrane assembly is in stable operation.

[0069] During the membrane element cleaning process, the third valve 63 and the ninth valve 69 can be opened to make the target solution flow into the membrane assembly 3 through the cleaning pump 5. After the membrane element cleaning is completed, the sixth valve 66, the seventh valve 67 and the ninth valve 69 can be opened to make the membrane assembly 3 in stable operation to filter the water and to respectively transport the reverse osmosis concentrated water and the reverse osmosis water (i.e. filtered water) in the membrane assembly 3 to the concentrated water tank 7 and the water tank 8.

[0070] Refer to Figure 2 It is shown that the cleaning pipeline is provided with a plurality of control nodes, which include one or more of a pressure control node PIC, a temperature control node TIC, a flow control node LIC, a PH detection node YI and a conductivity detection node CI. During actual cleaning, the pressure value, the temperature value, the PH value, the conductivity and the flow value of the dosing tank 1 or the cleaning pipeline can be detected through the above control nodes.

[0071] Continuously refer to Figure 2 The dosing tank 1 is preferably provided with the temperature control node TIC and / or the PH detection node YI for detecting the temperature value and the PH value in the dosing tank 1, respectively. At least one side of the filter 4 is preferably provided with the pressure control node PIC for detecting the liquid pressure flowing into and / or out of the filter 4. At least one of the flow control node LIC, the pressure control node PIC and the conductivity detection node CI is preferably arranged between the cleaning pump 5 and the membrane assembly 3 for measuring the liquid flow, the pressure and the conductivity flowing into the membrane assembly 3. At least one of the flow control node LIC, the pressure control node PIC, the PH detection node YI and the conductivity detection node CI is preferably arranged at the concentrated water outlet 31 and the water outlet 32 of the membrane assembly 3 for detecting the liquid flow, the pressure, the PH value and the conductivity at the concentrated water outlet 31 and the water outlet 32 of the membrane assembly.

[0072] Further, the reverse osmosis membrane cleaning system further comprises a detection device and a control device, the detection device comprising at least one of a pressure monitoring instrument, a temperature monitoring instrument, a flow meter monitoring instrument, a PH detection instrument and a conductivity detection instrument.

[0073] The pressure monitoring instrument is used for monitoring the pressure value at the pressure detection node PIC, the PH detection instrument is used for detecting the PH value at the PH detection node YI, the temperature monitoring instrument is used for monitoring the temperature value at the temperature control node TIC, the flow monitoring instrument is used for monitoring the flow value at the flow control node LIC, and the conductivity detection instrument is used for detecting the conductivity at the conductivity detection node CI, so as to realize the monitoring of the continuous operation state of the membrane module.

[0074] More specifically, the pressure monitoring instrument can be arranged at the pressure control node PIC, the temperature monitoring instrument can be arranged at the temperature control node TIC, the flow monitoring instrument can be arranged at the flow control node LIC, the PH detection instrument can be arranged at the PH detection node YI, and the conductivity detection instrument can be arranged at the conductivity detection node CI.

[0075] The pressure control instrument, the PH detection instrument, the temperature monitoring instrument, the flow monitoring instrument or the conductivity detection instrument are respectively connected with the control device and are used for transmitting the pressure signal, the temperature signal, the flow signal, the PH signal and the conductivity signal to the control device.

[0076] Preferably, the valve assembly is an electric valve and is controlled by the control device.

[0077] Further, the whole control process of the cleaning system is based on the control nodes, and in the preferred case, when the pressure value at the outlet of the membrane module 3 detected by the pressure control node PIC is increased by 0.1-0.3 MPa compared with the pressure value in the stable operation process, or when the flow value of the water outlet of the membrane module 3 detected by the flow control node LIC is decreased by more than 15% compared with the flow value in the stable operation process, the cleaning system will remind the operator to clean the membrane element.

[0078] The pressure monitoring instrument, the temperature monitoring instrument, the flow monitoring instrument, the PH detection instrument and the conductivity detection instrument in the application can be controlled by conventional instruments, which will not be described here.

[0079] Further, the reverse osmosis membrane cleaning system further comprises a drain pipeline, which is communicated with the membrane module 3 or the dosing tank 1 and is used for discharging the target solution in the cleaning pipeline.

[0080] In a specific example, the liquid discharge pipeline is arranged as an external discharge port (not shown) at the bottom of the dosing tank 1, and the external discharge port is used to discharge the liquid in the dosing tank 1 or the cleaning pipeline. In other examples, the liquid discharge pipeline can also be arranged on the membrane shell.

[0081] The cleaning method of the reverse osmosis membrane cleaning system includes:

[0082] S01, adding cleaning agent to the dosing tank 1.

[0083] S02, opening the dosing pump 2 and at least part of the valve assembly, and conveying the cleaning agent to the membrane assembly 3 through the dosing pump 2, so that the membrane element is placed in the membrane shell containing the cleaning agent.

[0084] S03, circulating the cleaning agent between the dosing tank 1, the dosing pump 2 and the membrane assembly 3 for a first predetermined time.

[0085] S04, closing the dosing pump 2 and at least part of the valve assembly, and soaking the membrane element in the membrane shell containing the cleaning agent for a second predetermined time.

[0086] S05, discharging the cleaning agent in the cleaning pipeline.

[0087] S06, adding cleaning liquid to the dosing tank 1.

[0088] S07, opening the dosing pump 2 and at least part of the valve assembly, and circulating the cleaning liquid between the dosing tank 1, the dosing pump 2 and the membrane assembly 3 until the PH value of the liquid in the membrane assembly 3 reaches a preset range.

[0089] S08, closing the dosing pump 2 and at least part of the valve assembly, and discharging the cleaning liquid in the cleaning pipeline to complete the cleaning of the membrane element.

[0090] The reverse osmosis membrane cleaning method can be used for online cleaning on a reverse osmosis membrane system stable running device, that is, the membrane element can be cleaned online without disassembly, and the cleaning effect of offline cleaning can be achieved. At the same time, the cleaning, soaking and flushing steps of the membrane element can be realized in sequence, which can improve the cleaning efficiency and meet the different cleaning requirements of the membrane element.

[0091] Further, the cleaning agent includes alkaline cleaning agent and acidic cleaning agent. The daily online cleaning and deep online cleaning steps of the membrane assembly each include three steps of alkaline cleaning, acid cleaning and flushing, and the type of cleaning agent used for cleaning the membrane element can be determined according to the type of pollutants in the membrane element.

[0092] In step S01, the step of adding cleaning agent to the dosing tank 1 includes:

[0093] S011. First, add alkaline cleaning agent to the dosing tank 1 and execute steps S02 to S07. Then, add acidic cleaning agent to the dosing tank 1 and execute steps S02 to S07. After that, execute steps S06 to S08 to complete the cleaning of the membrane element. In this way, all steps of alkaline washing, acid washing, and rinsing of the membrane element can be carried out in sequence, ensuring the removal of predetermined contaminants on the membrane element, and rinsing can thoroughly clean the alkaline and acidic cleaning agents in the dosing tank 1, membrane module 3, and the entire cleaning pipeline.

[0094] Preferably, each cleaning pipeline also includes a filter element 4 and a cleaning pump 5 connected to each other. The filter element 4 is connected to the dosing pump 2, and the cleaning pump 5 is connected to the membrane module 3.

[0095] In steps S02 and S07, the steps before turning on the dosing pump 2 include: turning on the cleaning pump 5.

[0096] In steps S04 and S08, the steps prior to shutting down the dosing pump 2 include: shutting down the cleaning pump 5.

[0097] Specifically, the dosing pump 2 and the cleaning pump 5 can be turned on when rinsing the membrane elements after cleaning to achieve the circulation of cleaning agents and cleaning solutions in the cleaning pipeline.

[0098] In steps S02 and S07, the step of opening at least a portion of the valve assembly includes:

[0099] Open the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, and the fifth valve 65 respectively.

[0100] In steps S04 and S08, the step of closing at least a portion of the valve assembly includes:

[0101] Close the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, and the fifth valve 65 respectively.

[0102] Furthermore, the reverse osmosis membrane cleaning system also includes a concentrate tank 7 and a product water tank 8. The valve assembly also includes a sixth valve 66 and a seventh valve 67, with the sixth valve 66 located between the concentrate outlet 31 of the membrane module 3 and the concentrate tank 7, and the seventh valve 67 located between the product water outlet 31 of the membrane module 3 and the product water tank 8.

[0103] Further, in step S01, the steps prior to adding the cleaning agent to the dosing tank 1 include:

[0104] Open the sixth valve 66 and the seventh valve 67 respectively to discharge the liquid in the membrane module 3 into the concentrate tank 7 and the product water tank 8.

[0105] Step S02 also includes: closing the sixth valve 66 and the seventh valve 67 respectively.

[0106] Further, the reverse osmosis membrane cleaning system further comprises a drain pipeline, which is in communication with the membrane module 3 or the chemical feeding tank 1 and is used for draining the target solution in the cleaning pipeline.

[0107] In step S05 and step S08, the step of draining the cleaning agent or cleaning solution in the cleaning pipeline comprises: draining the cleaning agent or cleaning solution in the cleaning pipeline through the drain pipeline.

[0108] In addition, the reverse osmosis membrane cleaning system further comprises a PH detection instrument, which is connected with the membrane module 3.

[0109] Step S03 further comprises: detecting the PH value of the liquid at the outlet of the membrane module 3 by the PH detection instrument; and adding the cleaning agent into the chemical feeding tank 1 if the PH value of the liquid at the outlet of the membrane module 3 is less than the preset value, so that the PH value of the cleaning agent in the chemical feeding tank 1 is always within the preset range during the cleaning process of the membrane element.

[0110] Step S07 further comprises: detecting the PH value of the liquid at the outlet of the membrane module 3 by the PH detection instrument until the PH value of the liquid in the membrane module 3 reaches the preset range when the membrane element is flushed, and then executing step S08.

[0111] In a non-limiting embodiment, the entire cleaning process of the membrane element comprises the following steps:

[0112] Firstly, before starting the cleaning of the membrane module 3, the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the chemical feeding pump 2 and the cleaning pump 5 are closed, and the sixth valve 66 and the seventh valve 67 are opened, so that the liquid in the membrane module 3 is drained into the concentrated water tank 8 and the product water tank 9, respectively.

[0113] Then, the membrane element is sequentially subjected to alkaline cleaning, acid cleaning and flushing.

[0114] Generally, the alkaline cleaning process of the membrane element comprises: firstly, circulating the alkaline cleaning agent in the cleaning pipeline to preliminarily dissolve the alkaline soluble pollutants on the membrane element.

[0115] In a non-limiting embodiment, the specific operation steps comprise: selecting the alkaline cleaning agent according to the type of the pollutants on the membrane element to be cleaned.

[0116] First, the sixth valve 66 and the seventh valve 67 are closed, and the alkaline cleaning agent is configured in the chemical feeding tank 1, which includes surfactant, lye and other components, and the PH of the alkaline cleaning agent is controlled between 10 and 12. Then, the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the chemical feeding pump 2 and the cleaning pump 5 are opened, the alkaline cleaning agent in the chemical feeding tank 1 is extracted by the chemical feeding pump 2 and is delivered to the security filter to remove impurities in the alkaline cleaning agent. Then, the alkaline cleaning agent is delivered to the membrane module 3 by the cleaning pump 5, and the alkaline cleaning agent is circulated in the membrane module 3 for a first predetermined time (for example, 0.5h~2h).

[0117] During the circulation of the alkaline cleaning agent, the PH of the alkaline cleaning agent at the concentrated water outlet 31 of the membrane module 3 can be detected by the PH detection instrument connected to the membrane module 3. When the PH of the alkaline cleaning agent decreases to 10 or less, the alkaline cleaning agent needs to be added in the chemical feeding tank 1 to maintain the PH between 10 and 12.

[0118] Secondly, the membrane element is soaked in the alkaline cleaning agent to further dissolve part of the pollutants on the membrane element.

[0119] In a non-limiting embodiment, the specific operation steps include: closing the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the chemical feeding pump 2 and the cleaning pump 5, and soaking the membrane element in the alkaline cleaning agent for a second predetermined time (for example, 0.5h~2h) to further dissolve the pollutants on the surface of the membrane element. After the soaking for the predetermined time, the liquid in the membrane module 3 (i.e., the mixture of the pollutants on the membrane element and the alkaline cleaning agent) can be discharged through the liquid discharge pipeline or the concentrated water tank 7.

[0120] Then, the membrane element is rinsed to remove the pollutants on the surface of the membrane element and the alkaline cleaning agent.

[0121] In a non-limiting embodiment, the specific operation steps include: opening the eighth valve 68 to add the reverse osmosis product water to the chemical feeding tank 1, rinsing the chemical feeding tank 1 by the reverse osmosis product water, and discharging the rinsed liquid through the discharge port of the chemical feeding tank 1. After the rinsing of the chemical feeding tank 1 is completed, the reverse osmosis product water is added to the chemical feeding tank 1 again, and the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the chemical feeding pump 2 and the cleaning pump 5 are opened, so that the reverse osmosis product water in the chemical feeding tank 1 is circulated in the cleaning pipeline to rinse the membrane element, and the rinsing time is expected to be 15min~60min.

[0122] After the predetermined time of flushing, the PH value of the reverse osmosis water at the concentrated water outlet 31 of the membrane module 3 can be detected by the PH detecting instrument connected to the membrane module 3. If the PH value of the reverse osmosis water at the concentrated water outlet 31 of the membrane module 3 is consistent with the PH value of the reverse osmosis water in the dosing tank 1, the flushing is stopped. Then the reverse osmosis water in the membrane module 3 can be discharged through the liquid discharge pipeline or the concentrated water pool 8 to end the whole alkaline cleaning process of the membrane element.

[0123] Then the acid cleaning step of the membrane element is entered. Generally, the acid cleaning process of the membrane element includes: first, circulating the acid cleaning agent in the cleaning pipeline to preliminarily dissolve the acid-soluble contaminants on the membrane element.

[0124] In a non-limiting embodiment, the specific operation steps include: selecting the acid cleaning agent according to the type of the contaminants on the membrane element to be cleaned. Then the acid cleaning agent is configured in the dosing tank 1. The acid cleaning agent can be composed of HCL, H3PO4, citric acid, etc. according to the contamination of the membrane element, and the PH value of the acid cleaning agent is controlled between 2 and 4. Then the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the dosing pump 2 and the cleaning pump 5 are opened. The acid cleaning agent in the dosing tank 1 is extracted by the dosing pump 2 and delivered to the safety filter to remove impurities in the acid cleaning agent. The acid cleaning agent is delivered to the membrane module 3 by the cleaning pump 5, and the acid cleaning agent is circulated in the membrane module 3 for a first predetermined time (for example, 0.5h~2h).

[0125] The PH change of the acid cleaning agent at the concentrated water outlet 31 of the membrane module 3 can be detected by the PH detecting instrument connected to the membrane module 3 during the circulation of the acid cleaning agent. When the PH of the acid cleaning agent is increased to above 4, the acid cleaning agent needs to be added in the dosing tank 1 to keep the PH between 2 and 4.

[0126] Secondly, the membrane element is soaked in the acid cleaning agent to further dissolve the contaminants on the membrane element.

[0127] In a non-limiting embodiment, the specific operation steps include: closing the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the dosing pump 2 and the cleaning pump 5, so that the membrane element is soaked in the acid cleaning agent for a second predetermined time (for example, 0.5h~2h) to make the acid cleaning agent further dissolve the contaminants on the surface of the membrane element. After the soaking, the liquid (i.e. the mixture of the contaminants on the membrane element and the acid cleaning agent) in the membrane module 3 can be discharged through the liquid discharge pipeline or the concentrated water pool 8.

[0128] Then the membrane element is flushed to remove the contaminants on the surface of the membrane element and the acid cleaning agent.

[0129] In a non-limiting embodiment, the specific operation steps include: opening the eighth valve 68 to add the reverse osmosis product water into the dosing tank 1, flushing the dosing tank 1 by the reverse osmosis product water, and discharging the flushing liquid through the discharge port of the dosing tank 1. After the flushing of the dosing tank 1 is completed, the reverse osmosis product water is added into the dosing tank 1 again, the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the dosing pump 2 and the cleaning pump 5 are opened, and the reverse osmosis product water in the dosing tank 1 is circulated in the cleaning pipeline to flush the membrane element, and the flushing time is expected to be 15 min to 60 min.

[0130] After the flushing for the predetermined time, the PH value of the reverse osmosis product water at the concentrated water outlet 31 of the membrane assembly 3 can be detected by the PH detection instrument connected with the membrane assembly 3. If the PH value of the reverse osmosis product water at the concentrated water outlet 31 of the membrane assembly 3 is consistent with the PH value of the reverse osmosis product water in the dosing tank 1, the flushing is stopped. Then the reverse osmosis product water in the membrane assembly 3 can be discharged through the liquid discharge pipeline or the concentrated water tank 8 to end the whole pickling process of the membrane element.

[0131] Subsequently, the flushing step of the membrane element is entered. Generally, the flushing process of the membrane element includes: first, all valve assemblies are closed. Then the reverse osmosis product water is added into the dosing tank 1, the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the dosing pump 2 and the cleaning pump 5 are opened. When the reverse osmosis product water reaches a predetermined flow rate, the reverse osmosis product water in the dosing tank 1 is circulated in the cleaning pipeline to flush the membrane element for a predetermined time (for example, 1 h to 2 h) to completely discharge the residual acidic cleaning agent, alkaline cleaning agent and pollutants in the dosing tank 1, the filter 4 and the membrane assembly 3.

[0132] After the flushing for the predetermined time, the PH value of the reverse osmosis product water at the concentrated water outlet 31 of the membrane assembly 3 can be detected by the PH detection instrument connected with the membrane assembly 3. If the PH value of the reverse osmosis product water at the concentrated water outlet 31 of the membrane assembly 3 is consistent with the PH value of the reverse osmosis product water in the dosing tank 1, the flushing is stopped. Then the reverse osmosis product water in the membrane assembly 3 can be discharged through the liquid discharge pipeline or the concentrated water tank 8 to end the whole pickling process of the membrane element.

[0133] The utility model will be explained in detail below in combination with the drawings and preferred embodiments.

[0134] <Embodiment 1>

[0135] In this embodiment, the reverse osmosis membrane cleaning system is used for the daily online cleaning of the membrane assembly.

[0136] The total pressure of the reverse osmosis membrane system is increased by 0.15 MPa compared with the initial operation, so the reverse osmosis membrane cleaning system needs to be cleaned online daily.

[0137] The reverse osmosis membrane cleaning system includes two cleaning pipelines, each of which includes two groups of membrane components. In the reverse osmosis membrane system, the pollutants on the membrane elements are mainly organic matter and inorganic salt scale, which need to be removed by online chemical cleaning.

[0138] Before online chemical cleaning, the conductivity, flow rate and pressure data of the water inlet, product water outlet and concentrated water outlet of the reverse osmosis membrane system are obtained by the control device.

[0139] The daily online cleaning of the membrane components includes three steps of alkaline cleaning, acid cleaning and rinsing.

[0140] The alkaline cleaning process of the membrane component 3 includes:

[0141] According to the type of pollutants on the membrane elements, a 3% NaOH solution and a 0.5% EDTA solution are selected as the alkaline cleaning agent, and the temperature in the dosing tank 1 is controlled at about 25°C. The pH value of the alkaline cleaning agent in the dosing tank 1 is controlled at 10-12.

[0142] First, add the alkaline cleaning agent to the dosing tank 1, open the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the dosing pump 2 and the cleaning pump 5, remove the impurities in the alkaline cleaning agent through the security filter, and make the alkaline cleaning agent circulate in the membrane component 3 for 30 min. The pH change of the alkaline cleaning agent at the concentrated water outlet 31 of the membrane component 3 is detected by the pH detector connected to the membrane component 3, and the pH value of the alkaline cleaning agent in the dosing tank 1 is controlled at 9.5-10.5 by adding the alkaline cleaning agent in the dosing tank 1.

[0143] Then, close the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the dosing pump 2 and the cleaning pump 5, and soak the membrane elements in the alkaline cleaning agent for 30 min to further dissolve the pollutants on the surface of the membrane elements.

[0144] Afterwards, the eighth valve 68 is opened to add the reverse osmosis product water to the dosing tank 1, the dosing tank 1 is flushed by the reverse osmosis product water, and the flushing liquid is discharged through the discharge port of the dosing tank 1. After the flushing of the dosing tank 1 is completed, the reverse osmosis product water is again added to the dosing tank 1, the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the dosing pump 2 and the cleaning pump 5 are opened, the membrane element is flushed by circulating the reverse osmosis product water in the cleaning pipeline, and the flushing time is expected to be 15 min until the PH value of the reverse osmosis product water at the concentrated water outlet 31 of the membrane assembly 3 is consistent with the PH value of the reverse osmosis product water in the dosing tank 1. After the flushing, the reverse osmosis product water in the membrane assembly 3 can be discharged through the liquid discharge pipeline to end the entire alkali washing process of the membrane element.

[0145] The acid washing process of the membrane assembly 3 includes:

[0146] According to the type of the pollutants on the membrane element, a citric acid solution with a composition of 1.5% is selected as the acid cleaning agent, the temperature in the dosing tank 1 is controlled at about 25°C, and the PH value of the acid cleaning agent in the dosing tank 1 is controlled at 2.5-3.5.

[0147] Firstly, the acid cleaning agent is added to the dosing tank 1, the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the dosing pump 2 and the cleaning pump 5 are opened, the impurities in the acid cleaning agent are removed through the security filter, and the acid cleaning agent is circulated in the membrane assembly 3 for 30 min. The PH change of the acid cleaning agent at the concentrated water outlet 31 of the membrane assembly 3 is detected by the PH detector connected to the membrane assembly 3, and the PH of the acid cleaning agent in the dosing tank 1 is controlled at 2.5-3.5 by adding the acid cleaning agent in the dosing tank 1.

[0148] Then, the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the dosing pump 2 and the cleaning pump 5 are closed, the membrane element is soaked in the acid cleaning agent for 30 min, and the pollutants on the surface of the membrane element are further dissolved.

[0149] Afterwards, the eighth valve 68 is opened to add the reverse osmosis product water into the dosing tank 1, the dosing tank 1 is flushed by the reverse osmosis product water, and the flushing liquid is discharged through the discharge port of the dosing tank 1. After the flushing of the dosing tank 1 is completed, the reverse osmosis product water is added into the dosing tank 1 again, the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the dosing pump 2 and the cleaning pump 5 are opened, the membrane element is flushed by circulating the reverse osmosis product water in the cleaning pipeline, and the flushing time is expected to be 15 min until the PH value of the reverse osmosis product water at the concentrated water outlet 31 of the membrane assembly 3 is consistent with the PH value of the reverse osmosis product water in the dosing tank 1. After the flushing, the reverse osmosis product water in the membrane assembly 3 can be discharged through the discharge pipeline to end the entire pickling process of the membrane element.

[0150] The flushing process of the membrane assembly 3 includes that all the valve assemblies are first closed. Then the reverse osmosis product water is added into the dosing tank 1, the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the dosing pump 2 and the cleaning pump 5 are opened, the reverse osmosis product water in the dosing tank 1 is circulated and flushed in the cleaning pipeline for 2 h to flush the membrane element at low pressure until the PH value of the reverse osmosis product water at the concentrated water outlet 31 of the membrane assembly 3 is consistent with the PH value of the reverse osmosis product water in the dosing tank 1, and the online chemical cleaning of the membrane element is completed. During the flushing process of the membrane assembly 3, the residual acidic cleaning agent, alkaline cleaning agent and pollutants in the dosing tank 1, the filter 4 and the membrane assembly 3 can be completely discharged.

[0151] Subsequently, the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the dosing pump 2 and the cleaning pump 5 are closed, and the sixth valve 66, the seventh valve 67 and the ninth valve 69 are opened to make the reverse osmosis membrane system run again.

[0152] The conductivity, flow rate and pressure data of the water inlet, product water outlet and concentrated water outlet of the reverse osmosis membrane system after the cleaning of the membrane element are obtained by the control device. By comparing with the data before the cleaning of the membrane element, it can be known that after the online chemical cleaning of the membrane assembly 3, under the condition that the water inlet temperature is 25℃, the water inlet pressure of the reverse osmosis membrane system is 1.33 MPa, the water inlet conductivity is 1550 μS / cm, the product water conductivity is 12.9 μS / cm, the desalination rate reaches 99.17%, and the water inlet pressure and the desalination rate of the reverse osmosis membrane system are restored to the conventional operation values.

[0153] <Example 2>

[0154] In this embodiment, the reverse osmosis membrane cleaning system is used for deep online cleaning of the membrane assembly.

[0155] The total water inlet pressure of the reverse osmosis membrane system is increased by 0.25 MPa compared with the initial operation, and the desalination rate is significantly reduced (for example, the desalination rate is reduced to 96.5%), which requires deep online cleaning by the reverse osmosis membrane cleaning system.

[0156] The reverse osmosis membrane cleaning system includes two cleaning pipelines, each of which includes two groups of membrane components. In the reverse osmosis membrane system, the pollutants on the membrane elements are mainly microorganisms, organic matter and inorganic salt scale, which need to be removed by online chemical deep cleaning.

[0157] Before online chemical cleaning, the conductivity, flow rate and pressure data of the water inlet, product water outlet and concentrated water outlet of the reverse osmosis membrane system are obtained by the control device.

[0158] The deep online cleaning of the membrane components includes three steps of alkaline cleaning, acid cleaning and rinsing.

[0159] The alkaline cleaning process of the membrane component 3 includes:

[0160] According to the type of pollutants on the membrane element, a 3% NaOH solution is selected as the alkaline cleaning agent, and the temperature in the dosing tank 1 is controlled at about 30°C. The PH value of the alkaline cleaning agent in the dosing tank 1 is controlled at about 11.

[0161] First, add alkaline cleaning agent to the dosing tank 1, open the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the dosing pump 2 and the cleaning pump 5, remove impurities in the alkaline cleaning agent through the security filter, and deliver the alkaline cleaning agent to the membrane component 3 through the cleaning pump 5, so that the alkaline cleaning agent circulates in the membrane component 3 for 2h. During the circulation process, the PH change of the alkaline cleaning agent at the concentrated water outlet 31 of the membrane component 3 is detected by the PH detector connected to the membrane component 3, and the PH of the alkaline cleaning agent in the dosing tank 1 is controlled between 10.5 and 11.5 by adding alkaline cleaning agent in the dosing tank 1.

[0162] Then, close the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the dosing pump 2 and the cleaning pump 5, and immerse the membrane element in the alkaline cleaning agent for 20h to further dissolve the pollutants on the surface of the membrane element.

[0163] Afterwards, the eighth valve 68 is opened to add the reverse osmosis product water into the dosing tank 1, the dosing tank 1 is flushed by the reverse osmosis product water, and the flushing liquid is discharged through the discharge port of the dosing tank 1. After the flushing of the dosing tank 1 is completed, the reverse osmosis product water is added into the dosing tank 1 again, the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the dosing pump 2 and the cleaning pump 5 are opened, the membrane element is flushed by circulating the reverse osmosis product water in the cleaning pipeline, until the PH value of the reverse osmosis product water at the concentrated water outlet 31 of the membrane assembly 3 is consistent with the PH value of the reverse osmosis product water in the dosing tank 1, and the flushing time is expected to be 1 h. After the flushing, the reverse osmosis product water in the membrane assembly 3 can be discharged through the liquid discharge pipeline to end the entire alkali washing process of the membrane element.

[0164] The acid washing process of the membrane assembly 3 includes:

[0165] According to the type of the pollutants on the membrane element, a citric acid solution with a concentration of 2% is selected as the acidic cleaning agent, the temperature in the dosing tank 1 is controlled at about 30°C, and the PH value of the acidic cleaning agent in the dosing tank 1 is controlled at about 2.

[0166] Firstly, the acidic cleaning agent is added into the dosing tank 1, the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the dosing pump 2 and the cleaning pump 5 are opened, the impurities in the acidic cleaning agent are removed through the security filter, and the acidic cleaning agent is circulated in the membrane assembly 3 for 2 h. The PH change of the acidic cleaning agent at the concentrated water outlet 31 of the membrane assembly 3 is detected by the PH detector connected with the membrane assembly 3, and the PH of the acidic cleaning agent in the dosing tank 1 is controlled between 2 and 3 by adding the acidic cleaning agent in the dosing tank 1.

[0167] Then, the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the dosing pump 2 and the cleaning pump 5 are closed, the membrane element is soaked in the acidic cleaning agent for 20 h, and the pollutants on the surface of the membrane element are further dissolved.

[0168] Afterwards, the eighth valve 68 is opened to add the reverse osmosis product water to the dosing tank 1, the dosing tank 1 is flushed by the reverse osmosis product water, and the flushing liquid is discharged through the discharge port of the dosing tank 1. After the flushing of the dosing tank 1 is completed, the reverse osmosis product water is again added to the dosing tank 1, the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the dosing pump 2 and the cleaning pump 5 are opened, the membrane element is flushed by circulating the reverse osmosis product water in the cleaning pipeline, and the flushing time is expected to be 1 h until the PH value of the reverse osmosis product water at the concentrated water outlet 31 of the membrane assembly 3 is consistent with the PH value of the reverse osmosis product water in the dosing tank 1. After the flushing, the reverse osmosis product water in the membrane assembly 3 can be discharged through the discharge pipeline to end the entire pickling process of the membrane element.

[0169] The flushing process of the membrane assembly 3 includes: first, all valve assemblies are closed. Then, the reverse osmosis product water is added to the dosing tank 1, the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the ninth valve 69, the dosing pump 2 and the cleaning pump 5 are opened, the reverse osmosis product water in the dosing tank 1 is circulated and flushed in the cleaning pipeline for 2 h to flush the membrane element at low pressure, and the online chemical cleaning of the membrane element is ended until the PH value of the reverse osmosis product water at the concentrated water outlet 31 of the membrane assembly 3 is consistent with the PH value of the reverse osmosis product water in the dosing tank 1. During the flushing process of the membrane assembly 3, the acid cleaning agent, the alkaline cleaning agent and the pollutants remaining in the dosing tank 1, the filter 4 and the membrane assembly 3 can be completely discharged.

[0170] Subsequently, the first valve 61, the second valve 62, the third valve 63, the fourth valve 64, the fifth valve 65, the dosing pump 2 and the cleaning pump 5 are closed, and the sixth valve 66, the seventh valve 67 and the ninth valve 69 are opened to make the reverse osmosis membrane system run again.

[0171] The conductivity, flow rate and pressure data of the water inlet, product water outlet and concentrated water outlet of the reverse osmosis membrane system after the cleaning of the membrane element are obtained by the control device. By comparing with the data before the cleaning of the membrane element, it can be known that after the online chemical cleaning of the membrane assembly 3, under the condition that the water inlet temperature is 30℃, the water inlet pressure of the reverse osmosis membrane system is reduced to 1.4 MPa, the water inlet conductivity is 2200 μS / cm, the product water conductivity is 22.7 μS / cm, and the desalination rate reaches 98.96%, that is, the water inlet pressure and the desalination rate of the reverse osmosis membrane system are restored to the conventional operation values.

[0172] In conclusion, the reverse osmosis membrane cleaning system can be used for online cleaning on the equipment with stable operation of the reverse osmosis membrane system, that is, the system can clean the membrane element online without disassembling the membrane element, and the cleaning effect of offline cleaning can be achieved.

[0173] The above description is only a description of the preferred embodiments of the utility model, and does not limit the scope of the utility model in any way, and any modification or modification of the above disclosure by a person skilled in the art belongs to the protection scope of the utility model.

Claims

1. A reverse osmosis membrane cleaning system, characterized by, The cleaning system comprises at least one cleaning pipeline, the cleaning pipeline comprises a dosing tank, a dosing pump and a membrane assembly connected in sequence, the dosing tank is configured to contain and mix a target solution, the dosing pump is configured to obtain and deliver the target solution from the dosing tank; the membrane assembly comprises a membrane element and a membrane shell, the membrane shell is used to contain the membrane element and the target solution; the cleaning system further comprises a valve assembly, at least part of the valve assembly is used to open when cleaning the membrane element, so that the target solution circulates between the dosing tank, the dosing pump and the membrane assembly; The target solution comprises a cleaning agent and a cleaning liquid, the cleaning agent is used to dissolve and remove contaminants on the membrane element, and the cleaning liquid is used to flush the dosing tank and the membrane element.

2. The reverse osmosis membrane cleaning system of claim 1, wherein, Each of the cleaning pipelines further comprises a filter and a cleaning pump connected in sequence, the filter and the cleaning pump are arranged between the dosing pump and the membrane assembly; wherein the filter is in communication with the dosing pump, and the cleaning pump is in communication with the membrane assembly; the filter is configured to remove particulate matter in the cleaning agent, and the cleaning pump is configured to obtain the target solution from the filter and deliver the target solution to the membrane assembly.

3. The reverse osmosis membrane cleaning system of claim 2, wherein, The number of the cleaning pumps and the number of the membrane assemblies are both plural, the cleaning pump is configured to be connected with a corresponding membrane assembly and provide the target solution to the corresponding membrane assembly.

4. The reverse osmosis membrane cleaning system of claim 2, wherein, The number of the cleaning pipelines is at least two, each of the cleaning pipelines comprises the dosing tank, the dosing pump, the filter, the cleaning pump and the membrane assembly connected in sequence.

5. The reverse osmosis membrane cleaning system of claim 4, wherein, Each of the cleaning pipelines comprises a plurality of cleaning pumps and a plurality of membrane assemblies, each of the membrane assemblies is in communication with a corresponding cleaning pump; all of the cleaning pumps on the two cleaning pipelines are respectively connected with the filter on each of the cleaning pipelines.

6. The reverse osmosis membrane cleaning system of any one of claims 1-5, wherein, The valve assembly comprises a first valve, the first valve is arranged between the dosing tank and the dosing pump.

7. The reverse osmosis membrane cleaning system of any one of claims 2-5, wherein, The valve assembly further comprises a second valve, the second valve is arranged between the cleaning pump and the filter.

8. The reverse osmosis membrane cleaning system of claim 7, wherein, The number of the cleaning pumps and the number of the second valves are both plural, each of the cleaning pumps is in communication with the filter through a corresponding second valve.

9. The reverse osmosis membrane cleaning system of any one of claims 2-5, wherein, The valve assembly further comprises a third valve, the third valve is arranged between the cleaning pump and the membrane assembly.

10. The reverse osmosis membrane cleaning system of any one of claims 1-5, wherein, The valve assembly further comprises a fourth valve and a fifth valve; the membrane assembly has a concentrated water outlet and a product water outlet, the fourth valve is arranged between the concentrated water outlet of the membrane assembly and the dosing tank, and the fifth valve is arranged between the product water outlet of the membrane assembly and the dosing tank.

11. The reverse osmosis membrane cleaning system of claim 10, wherein, Further comprising a concentrated water pool and a product water pool, the valve assembly further comprises a sixth valve and a seventh valve, the sixth valve is arranged between the concentrated water outlet of the membrane assembly and the concentrated water pool, and the seventh valve is arranged between the product water outlet of the membrane assembly and the product water pool.

12. The reverse osmosis membrane cleaning system of claim 11, wherein, The valve assembly further comprises an eighth valve, which is arranged between the water production tank and the dosing tank, and is used to supply the cleaning liquid to the dosing tank.

13. The reverse osmosis membrane cleaning system of any one of claims 2-5, wherein, The cleaning pipeline is provided with a plurality of control nodes, which include one or more of a pressure control node, a temperature control node, a flow control node, a PH detection node and a conductivity detection node.

14. The reverse osmosis membrane cleaning system of claim 13, wherein, The dosing tank is provided with the temperature control node and / or the PH detection node, And / or, at least one side of the filter is provided with the pressure control node, And / or, at least one of the flow control node, the pressure control node and the conductivity detection node is arranged between the cleaning pump and the membrane assembly, And / or, at least one of the flow control node, the pressure control node, the PH detection node and the conductivity detection node is arranged at the concentrated water outlet and the water production outlet of the membrane assembly.

15. The reverse osmosis membrane cleaning system of claim 13, wherein the cleaning solution is a mixture of water and a cleaning agent. Further comprising a detection device and a control device, the detection device includes at least one of a pressure monitoring instrument, a PH detection instrument, a temperature monitoring instrument, a flow monitoring instrument and a conductivity detection instrument; The pressure control instrument, the PH detection instrument, the temperature monitoring instrument, the flow monitoring instrument or the conductivity detection instrument are respectively connected with the control device; The pressure monitoring instrument is used to monitor the pressure value at the pressure detection node, the PH detection instrument is used to detect the PH value at the PH detection node, the temperature monitoring instrument is used to monitor the temperature value at the temperature control node, the flow monitoring instrument is used to monitor the flow value at the flow control node, and the conductivity detection instrument is used to detect the conductivity at the conductivity detection node.

Images