Alkali-resistant film treatment system

Abstract

The application relates to an alkali-resistant film treatment system, which comprises a raw material tank, a purified liquid tank, a concentrated liquid tank, a first alkali-resistant film element, a second alkali-resistant film element and a third alkali-resistant film element; the discharge port of the raw material tank is connected with the feed end of the first alkali-resistant film element, the permeate outlet of the first alkali-resistant film element is connected with the feed port of the purified liquid tank, and the concentrated liquid outlet of the first alkali-resistant film element is connected with the feed end of the second alkali-resistant film element; the permeate outlet of the second alkali-resistant film element is connected with the feed port of the raw material tank, the concentrated liquid outlet of the second alkali-resistant film element is connected with the feed end of the third alkali-resistant film element, and the concentrated liquid outlet of the second alkali-resistant film element is connected with the feed end of second alkali-resistant film element through a first reflux pipeline; the permeate outlet of the third alkali-resistant film element is connected with the feed port of the raw material tank, the concentrated outlet of the third alkali-resistant film element is connected with the feed end of the concentrated liquid tank, and the concentrated liquid outlet of the third alkali-resistant film element is connected with the feed end of the third alkali-resistant film element through a second reflux pipeline.

Description

Technical Field

[0001] This application relates to the field of waste alkali liquid recycling and treatment technology, and in particular to an alkali-resistant membrane treatment system. Background Technology

[0002] Driven by environmental protection and energy conservation policies, waste alkali solution has become a resource with significant recycling value in the industrial sector. For major alkali consumers such as the semi-fiber industry, steel industry, and dyeing and printing industry, recycling waste alkali solution can not only significantly reduce operating costs in alkali solution procurement but also promote the circular use of alkali solution in the production process, aligning with the concept of green development. Existing alkali-resistant membrane purification methods are widely used in industrial practice due to their relatively simple operation and strong adaptability to the properties of waste alkali solution. However, in actual operation, existing alkali-resistant membrane treatment devices only process the waste alkali solution once before discharging the separated waste alkali solution. Because the alkali in the waste alkali solution does not have sufficient time to be separated within the alkali-resistant membrane treatment device before flowing out, a large amount of recyclable alkali solution is wasted, resulting in a generally low alkali solution recovery rate.

[0003] Therefore, how to improve the recovery rate of alkali solution has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, this application proposes an alkali-resistant membrane treatment system, comprising: a raw material tank, a purified liquid tank, a concentration tank, a first-stage alkali-resistant membrane element, a second-stage alkali-resistant membrane element, and a third-stage alkali-resistant membrane element; The outlet of the raw material tank is connected to the feed end of the first alkali-resistant membrane element, the permeate outlet of the first alkali-resistant membrane element is connected to the feed inlet of the clean liquid tank, and the concentrate outlet of the first alkali-resistant membrane element is connected to the feed end of the second alkali-resistant membrane element. The permeate outlet of the second-stage alkali-resistant membrane element is connected to the feed inlet of the raw material tank, the concentrate outlet of the second-stage alkali-resistant membrane element is connected to the feed end of the third-stage alkali-resistant membrane element, and the concentrate outlet of the second-stage alkali-resistant membrane element is connected to the feed end of the second-stage alkali-resistant membrane element through the first reflux pipeline. The permeate outlet of the three-stage alkali-resistant membrane element is connected to the feed inlet of the raw material tank, the concentrate outlet of the three-stage alkali-resistant membrane element is connected to the feed end of the concentration tank, and the concentrate outlet of the three-stage alkali-resistant membrane element is connected to the feed end of the three-stage alkali-resistant membrane element through the second reflux pipeline.

[0005] In one possible implementation, a pre-processing conveying unit is also included; The raw material tank is connected to the feed end of an alkali-resistant membrane element via a pretreatment conveying unit.

[0006] In one possible implementation, the pretreatment conveying unit includes: a feed pump, a security filter, and a high-pressure pump; The input end of the feed pump is connected to the outlet of the raw material tank, the output end of the feed pump is connected to the input end of the security filter, the output end of the security filter is connected to the input end of the high-pressure pump, and the output end of the high-pressure pump is connected to the feed end of a section of alkali-resistant membrane element.

[0007] One possible implementation method also includes: a single-stage circulation pump, a two-stage circulation pump, and a three-stage circulation pump; The input end of a circulating pump is connected to the output end of a high-pressure pump, and the output end of a circulating pump is connected to the feed end of an alkali-resistant membrane element. The input end of the second-stage circulating pump is connected to the concentrate outlet of the first-stage alkali-resistant membrane element, and the output end of the second-stage circulating pump is connected to the feed end of the second-stage alkali-resistant membrane element. The input end of the three-stage circulating pump is connected to the concentrate outlet of the two-stage alkali-resistant membrane element, and the output end of the three-stage circulating pump is connected to the feed end of the three-stage alkali-resistant membrane element.

[0008] In one possible implementation, an alkali-resistant membrane element has two or more components; Two or more alkali-resistant membrane elements are connected in series along the direction of waste alkali liquid transportation, and the permeate outlets of the two or more alkali-resistant membrane elements are all connected to the feed inlet of the clean liquid tank.

[0009] In one possible implementation, an alkali-resistant membrane element is provided with three [elements].

[0010] One possible implementation method also includes: a cleaning tank and a waste liquid tank; The conveying end of the cleaning tank is connected to the feed end of the first alkali-resistant membrane element, the feed end of the second alkali-resistant membrane element, and the feed end of the third alkali-resistant membrane element, respectively. The permeate cleaning return outlet of the first alkali-resistant membrane element, the permeate cleaning return outlet of the second alkali-resistant membrane element, and the permeate cleaning return outlet of the third alkali-resistant membrane element are all connected to the first inlet of the cleaning tank. The concentrated cleaning reflux outlets of the first-stage alkali-resistant membrane element, the second-stage alkali-resistant membrane element, and the third-stage alkali-resistant membrane element are all connected to the inlet of the waste liquid tank.

[0011] One possible implementation method also includes: a cleaning pump and a cleaning filter; The conveying end of the cleaning tank is connected to the input end of the cleaning pump, the output end of the cleaning pump is connected to the input end of the cleaning filter, and the output end of the cleaning filter is connected to the feed ends of the first, second, and third alkali-resistant membrane elements, respectively.

[0012] One possible implementation method is a loop pipeline; The inlet of the circulation pipeline is connected to the permeate outlets of the first, second, and third alkali-resistant membrane elements, respectively, and the outlet of the circulation pipeline is connected to the second inlet of the cleaning tank.

[0013] Beneficial effects of this application This application establishes a multi-stage concentration and recovery system using a first-stage, second-stage, and third-stage alkali-resistant membrane element. Waste alkali solution from the raw material tank first enters the first-stage alkali-resistant membrane element, where the permeate, as a relatively pure alkali solution, is recycled and reused in the clean liquid tank. The concentrated solution then enters the second-stage alkali-resistant membrane element for further treatment. The permeate from the second-stage membrane element is returned to the raw material tank for further treatment. The second-stage concentrated solution then re-enters the third-stage alkali-resistant membrane element for advanced treatment. This cyclical treatment method ensures thorough separation and recovery of alkali solution from the waste alkali solution, improving efficiency. The improved alkali recovery rate reduces the company's alkali procurement, lowers operating costs, and enhances economic efficiency. Furthermore, by installing first and second reflux pipelines, the second-stage concentrate from the second-stage alkali-resistant membrane element and the waste liquid from the third-stage alkali-resistant membrane element are partially returned to their respective feed ends for further treatment. This allows for more thorough separation of alkali in the waste alkali solution. Simultaneously, the permeate from the second and third-stage alkali-resistant membrane elements is returned to the raw material tank for recycling, further improving the alkali recovery efficiency.

[0014] The processing device of this application can realize segmented cleaning and segmented operation; the operation mode can be adjusted in real time according to the operation.

[0015] Other features and aspects of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0016] The accompanying drawings, which are included in and form part of this specification, illustrate exemplary embodiments, features, and aspects of this application together with the specification and serve to explain the principles of this application.

[0017] Figure 1 The main structural diagram of the alkali-resistant membrane treatment system of this application is shown.

[0018] Raw material tank 110; purified liquid tank 120; concentration tank 130; first-stage alkali-resistant membrane element 210; first-stage circulation pump 211; second-stage alkali-resistant membrane element 220; second-stage circulation pump 221; first reflux pipeline 222; third-stage alkali-resistant membrane element 230; third-stage circulation pump 231; second reflux pipeline 223; feed pump 310; security filter 320; high-pressure pump 330; cleaning tank 410; waste liquid tank 440; cleaning pump 420; cleaning filter 430; circulation pipeline 500; third control valve 510; first control valve 610; second control valve 620. Detailed Implementation Various exemplary embodiments, features, and aspects of this application will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0019] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model or simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0021] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0022] Furthermore, to better illustrate this application, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this application can be implemented without certain specific details. In some instances, methods, means, components, and circuits well-known to those skilled in the art have not been described in detail in order to highlight the main points of this application.

[0023] This application discloses an alkali-resistant membrane treatment system, comprising: a raw material tank 110, a purified liquid tank 120, a concentration tank 130, a first-stage alkali-resistant membrane element 210, a second-stage alkali-resistant membrane element 220, and a third-stage alkali-resistant membrane element 230; the outlet of the raw material tank 110 is connected to the inlet of the first-stage alkali-resistant membrane element 210, the permeate outlet of the first-stage alkali-resistant membrane element 210 is connected to the inlet of the purified liquid tank 120, and the concentrate outlet of the first-stage alkali-resistant membrane element 210 is connected to the inlet of the second-stage alkali-resistant membrane element 220; the permeate outlet of the second-stage alkali-resistant membrane element 220 is connected to the inlet of the raw material tank 110. The feed inlet is connected as follows: the concentrated liquid outlet of the second-stage alkali-resistant membrane element 220 is connected to the feed end of the third-stage alkali-resistant membrane element 230, and the concentrated liquid outlet of the second-stage alkali-resistant membrane element 220 is connected to the feed end of the second-stage alkali-resistant membrane element 220 through the first reflux pipe 222; the permeate outlet of the third-stage alkali-resistant membrane element 230 is connected to the feed inlet of the raw material tank 110, the concentrated liquid outlet of the third-stage alkali-resistant membrane element 230 is connected to the feed end of the concentration tank 130, and the concentrated liquid outlet of the third-stage alkali-resistant membrane element 230 is connected to the feed end of the third-stage alkali-resistant membrane element 230 through the second reflux pipe 223.

[0024] It should be noted that the raw material tank 110 is used to store the waste alkali solution to be treated, and simultaneously receives the permeate from the second-stage alkali-resistant membrane element 220 and the third-stage alkali-resistant membrane element 230, thereby realizing the recycling of the insufficiently purified waste alkali solution; the purified liquid tank 120 is suitable for collecting the permeate (i.e., reusable alkali solution) produced by the first-stage alkali-resistant membrane element 210, facilitating the direct reuse of the alkali solution in subsequent production; the first-stage alkali-resistant membrane element 210 is used to filter and separate the waste alkali solution transported by the raw material tank 110, and the permeate (i.e., reusable alkali solution) produced is transported to the purified liquid tank 120 through the permeate outlet of the first-stage alkali-resistant membrane element 210, and the treated product... The concentrated solution is conveyed from the concentrated solution outlet of the first-stage alkali-resistant membrane element 210 to the second-stage alkali-resistant membrane element 220. The design of the first-stage alkali-resistant membrane element 210 reduces the filtration load on the subsequent second-stage and third-stage alkali-resistant membrane elements 220 and 230, while rapidly producing reusable alkali solution and increasing the overall qualified alkali solution yield of the system. The second-stage alkali-resistant membrane element 220 is used to perform secondary treatment on the concentrated solution conveyed by the first-stage alkali-resistant membrane element 210. The permeate produced by the treatment flows back to the raw material tank 110 through the permeate outlet of the second-stage alkali-resistant membrane element 220, and the concentrated solution produced by the treatment is conveyed to the third-stage alkali-resistant membrane element 220 through the concentrated solution outlet of the second-stage alkali-resistant membrane element 220. 230. Simultaneously, a portion of the second-stage concentrate is returned to the feed end of the second-stage alkali-resistant membrane element 220 via the first return pipeline 222, thereby maximizing the recovery of alkali in the second-stage concentrate. A portion of the second-stage concentrate mixes with the concentrate conveyed by the first-stage alkali-resistant membrane element 210 and then enters the second-stage alkali-resistant membrane element 220 for further treatment. The design of the first return pipeline 222 increases the number of times the second-stage alkali-resistant membrane element 220 filters the concentrate, improving the alkali recovery rate. The third-stage alkali-resistant membrane element 230 is suitable for deep treatment of the second-stage concentrate conveyed by the second-stage alkali-resistant membrane element 220. The permeate produced after treatment is returned through the permeate outlet of the third-stage alkali-resistant membrane element 230. The waste liquid generated from the deep treatment is transported to the concentrate tank 130 through the concentrate outlet of the three-stage alkali-resistant membrane element 230 in the raw material tank 110. The design of the concentrate tank 130 facilitates centralized treatment of the waste liquid and avoids pollution caused by direct discharge. At the same time, a portion of the waste liquid is returned to the feed end of the three-stage alkali-resistant membrane element 230 through the second return pipeline 223, thereby maximizing the recovery of alkali in the waste liquid. A portion of the waste liquid is mixed with the second-stage concentrate transported by the second-stage alkali-resistant membrane element 220 and then enters the three-stage alkali-resistant membrane element 230 for further treatment. The design of the second return pipeline 223 ensures that the alkali in the waste liquid is separated to the maximum extent, thereby improving the alkali recovery rate.

[0025] When the alkali-resistant membrane treatment system is working, the waste alkali solution in the raw material tank 110 enters the first-stage alkali-resistant membrane element 210. The first-stage alkali-resistant membrane element 210 filters and separates the waste alkali solution. The high-purity permeate produced by the treatment directly enters the clean liquid tank 120 as a recycled product for production. The resulting concentrated liquid is then transported to the second-stage alkali-resistant membrane element 220, where it undergoes secondary treatment. The permeate produced by this secondary treatment (which, although not pure enough to enter the clean liquid tank 120, still has recycling value) flows back to the raw material tank 110 for recycling. Part of the second-stage concentrate is returned to the feed end of the second-stage alkali-resistant membrane element 220 through the first return pipeline 222 for recycling. The other part of the second-stage concentrate enters the third-stage alkali-resistant membrane element 230, which performs deep treatment on the second-stage concentrate. The permeate generated from the treatment is returned to the raw material tank 110 for recycling. Part of the waste liquid generated from the treatment is returned to the feed end of the third-stage alkali-resistant membrane element 230 through the second return pipeline 223 for recycling. The other part of the waste liquid is transported to the concentration tank 130 for centralized treatment.

[0026] It should be noted that the permeate produced by the first-stage alkali-resistant membrane element 210 can directly enter the purified liquid tank 120. When the waste alkali solution enters the first-stage alkali-resistant membrane element 210, it is in a relatively clean state, and the operating pressure and membrane surface flow rate are within the optimal range. This results in a high impurity separation rate of the waste alkali solution by the first-stage alkali-resistant membrane element 210. Therefore, the impurity content of the permeate from the first-stage alkali-resistant membrane element 210 is low, meeting the reuse standards of the production process, and thus it is directly sent to the purified liquid tank 120. The second-stage alkali-resistant membrane element 220 processes the concentrated solution separated by the first-stage alkali-resistant membrane element 210. The third-stage alkali-resistant membrane element... Unit 230 processes the concentrate separated by the two-stage alkali-resistant membrane element 220. The higher impurity concentration of the concentrate leads to an increase in osmotic pressure. Under high pressure, more small molecule impurities are forced to pass through the membrane pores of the two-stage or three-stage alkali-resistant membrane element 220. Therefore, the impurity content of the permeate produced by the two-stage or three-stage alkali-resistant membrane element 220 is higher than that of the permeate from the one-stage alkali-resistant membrane element 210, which cannot meet the standard for reuse in production. However, these permeates still contain a large amount of alkali, so they are returned to the raw material tank 110 for recycling, thereby improving the alkali recovery efficiency.

[0027] The alkali-resistant membrane element 210, 220, and 230 configured in this application form a multi-stage concentration and recovery system. The waste alkali solution in the raw material tank 110 first enters the first-stage alkali-resistant membrane element 210, and its permeate, as a relatively pure alkali solution, enters the purified liquid tank 120 for recycling. The concentrated solution enters the second-stage alkali-resistant membrane element 220 for further treatment. The permeate from the second-stage alkali-resistant membrane element 220 is returned to the raw material tank 110 for further treatment. The second-stage concentrated solution then enters the third-stage alkali-resistant membrane element 230 for further processing. This cyclical treatment method ensures that the alkali solution in the waste alkali solution is fully separated and recovered. This system improves the recovery rate of alkali solution, reduces the company's alkali solution procurement, lowers operating costs, and enhances the company's economic efficiency. Furthermore, by setting up the first reflux pipeline 222 and the second reflux pipeline 223, the second-stage concentrate generated by the second-stage alkali-resistant membrane element 220 and the waste liquid generated by the third-stage alkali-resistant membrane element 230 are returned to their respective feed ends for further processing. This allows for more complete separation of alkali solution in the waste alkali solution. Simultaneously, the permeate generated by the second-stage and third-stage alkali-resistant membrane elements 220 and 230 is returned to the raw material tank 110 for recycling, further improving the alkali solution recovery efficiency.

[0028] In one possible implementation, a pretreatment conveying unit is also included; the raw material tank 110 is connected to the feed end of an alkali-resistant membrane element 210 via the pretreatment conveying unit.

[0029] It should be noted that the feed end of the pretreatment unit is connected to the discharge port of the raw material tank 110, and the discharge end of the pretreatment unit is connected to the feed end of the first alkali-resistant membrane element 210. The pretreatment conveying unit is suitable for pretreating the waste alkali solution in the raw material tank 110 and then conveying it to the first alkali-resistant membrane element 210, thereby providing a relatively stable waste alkali solution to the first alkali-resistant membrane element 210 and ensuring the stability of the system operation.

[0030] In one possible implementation, the pretreatment conveying unit includes: a feed pump 310, a security filter 320, and a high-pressure pump 330; the input end of the feed pump 310 is connected to the outlet of the raw material tank 110, the output end of the feed pump 310 is connected to the input end of the security filter 320, the output end of the security filter 320 is connected to the input end of the high-pressure pump 330, and the output end of the high-pressure pump 330 is connected to the feed end of an alkali-resistant membrane element 210.

[0031] It should be noted that the feed pump 310 is suitable for continuously and stably transporting the static waste alkali liquid in the raw material tank 110 to the subsequent security filter 320, ensuring the continuity of the treatment process of the first-stage alkali-resistant membrane element 210. The security filter 320 intercepts large particulate suspended matter, colloids and other impurities in the waste alkali liquid through its built-in filter element, reducing the damage to the first-stage alkali-resistant membrane element 210 caused by such impurities. The high-pressure pump 330 is suitable for pressurizing the waste alkali liquid after filtration by the security filter 320 to the working pressure required by the first-stage alkali-resistant membrane element, ensuring that the waste alkali liquid can effectively permeate the membrane layer of the first-stage alkali-resistant membrane element 210, and avoiding low alkali liquid permeation efficiency due to insufficient pressure.

[0032] In one possible implementation, a circulation pump is also included; the circulation pump comprises a first-stage circulation pump 211, a second-stage circulation pump 221, and a third-stage circulation pump 231. The input end of the first-stage circulation pump 211 is connected to the output end of the high-pressure pump 330, and the output end of the first-stage circulation pump 211 is connected to the feed end of the first-stage alkali-resistant membrane element 210. The first-stage circulation pump 211 is suitable for receiving waste alkali solution that has been initially pressurized by the high-pressure pump 330. The first-stage circulation pump 211 provides a stable flow rate and pressure for the waste alkali solution flowing through the first-stage alkali-resistant membrane element 210 through circulation regulation. The input end of the second-stage circulation pump 221 is connected to the concentrate outlet of the first-stage alkali-resistant membrane element 210, and the output end of the second-stage circulation pump 221 is connected to the feed end of the second-stage alkali-resistant membrane element 220. The second-stage circulation pump 221 is suitable for receiving the concentrate discharged from the first-stage alkali-resistant membrane element 210. The second-stage circulation pump 221 performs pressurization compensation on the concentrate to ensure that the pressure of the concentrate delivered to the second-stage alkali-resistant membrane device meets the requirements of the second-stage alkali-resistant membrane element. The second-stage circulation pump 221 provides power for the second-stage concentrate returned through the first return pipeline 222, allowing this portion of the second-stage concentrate to re-enter the second-stage alkali-resistant membrane element 220 for secondary filtration, reducing the loss of effective alkali. The input end of the third-stage circulation pump 231 is connected to the concentrate outlet of the second-stage alkali-resistant membrane element 220, and the output end of the third-stage circulation pump 231 is connected to the feed end of the third-stage alkali-resistant membrane element 230. The third-stage circulation pump 231 is suitable for receiving the second-stage concentrate discharged from the second-stage alkali-resistant membrane. The third-stage circulation pump 231 pressurizes the second-stage concentrate to ensure that the pressure of the second-stage concentrate delivered to the third-stage alkali-resistant membrane device meets the filtration requirements of the third-stage alkali-resistant membrane element 230. At the same time, the third-stage circulation pump 231 provides power for the deep concentrate returned through the second return pipeline 223, allowing this portion of the concentrate to re-enter the third-stage alkali-resistant membrane element 230 for deep filtration, maximizing the recovery of residual effective alkali.

[0033] In one possible implementation, there are two or more alkali-resistant membrane elements 210; the two or more alkali-resistant membrane elements 210 are connected in series along the waste alkali liquid conveying direction, and the permeate outlets of the two or more alkali-resistant membrane elements 210 are all connected to the feed inlet of the clean liquid tank 120.

[0034] It should be noted that among the two or more alkali-resistant membrane elements 210 connected in series: the first alkali-resistant membrane element 210 located at the start of the series connection has its feed end connected to the output end of the high-pressure pump 330 via a circulating pump 211, which is used to receive the waste alkali liquid after being pressurized by the high-pressure pump 330 and the flow rate and pressure regulated by the first circulating pump, thus starting the first filtration stage; between each two adjacent alkali-resistant membrane elements 210, the concentrate outlet of the previous alkali-resistant membrane element 210 is connected to the feed end of the next alkali-resistant membrane element 210, so that the concentrate that has not permeated after filtration by the previous alkali-resistant membrane element 210 can be successively transported to the next alkali-resistant membrane element 210 for multiple retention and purification; the permeate outlets of the two or more alkali-resistant membrane elements 210 are all connected to the feed inlet of the clean liquid tank 120, ensuring that the permeate generated by filtration by the two or more alkali-resistant membrane elements 210 is uniformly collected in the clean liquid tank 120 for subsequent production reuse, thus avoiding the loss of permeate.

[0035] Preferably, one section of alkali-resistant film element 210 has three components.

[0036] In one possible implementation, the first alkali-resistant membrane element 210, the second alkali-resistant membrane element 220, and the third alkali-resistant membrane element 230 can be any of the existing models of alkali-resistant membrane JRTNF8040A, JRTNF8040B, and JRTNF8040C, or they can be used in combination according to actual needs.

[0037] In one possible implementation, two or more first control valves 610 are also included, which are respectively located at the permeate outlet, the concentrate outlet, and the input end of the first circulation pump 211 of the first alkali-resistant membrane element 210. Specifically, the output end of the high-pressure pump 330 is connected to the input end of the first control valve 610, the output end of the first control valve 610 is connected to the input end of the first circulation pump 211, the permeate outlet of the first alkali-resistant membrane element 210 is connected to the input end of the first control valve 610, the output end of the first control valve 610 is connected to the inlet of the purified liquid tank 120, the concentrate outlet of the first alkali-resistant membrane element 210 is connected to the input end of the first control valve 610, and the output end of the first control valve 610 is connected to the inlet of the second alkali-resistant membrane element 220.

[0038] Furthermore, two or more first control valves 610 are respectively installed at the permeate outlet, concentrate outlet, and input end of the second-stage alkali-resistant membrane element 220; the second alkali-resistant membrane element is equipped with the first control valve 610 in the same way and with the same function as the first alkali-resistant membrane element, as described in detail above, and will not be repeated here.

[0039] Furthermore, two or more first control valves 610 are respectively installed at the permeate outlet, concentrate outlet, and input end of the three-stage alkali-resistant membrane element 230; the third alkali-resistant membrane element is equipped with the first control valve 610 in the same way and with the same function as the first alkali-resistant membrane element. The above-described description will not be repeated here.

[0040] In one possible implementation, both the first reflux line 222 and the second reflux line 223 are equipped with flow control valves, and the feed end of the concentration tank 130 is equipped with a first control valve 610.

[0041] In one possible implementation, the system further includes a cleaning tank 410 and a waste liquid tank 440; the conveying end of the cleaning tank 410 is connected to the feed end of the first alkali-resistant membrane element 210, the feed end of the second alkali-resistant membrane element 220, and the feed end of the third alkali-resistant membrane element 230, respectively; the permeate cleaning return outlet of the first alkali-resistant membrane element 210, the permeate cleaning return outlet of the second alkali-resistant membrane element 220, and the permeate cleaning return outlet of the third alkali-resistant membrane element 230 are all connected to the first inlet of the cleaning tank 410; the concentrate cleaning return outlet of the first alkali-resistant membrane element 210, the concentrate cleaning return outlet of the second alkali-resistant membrane element 220, and the concentrate cleaning return outlet of the third alkali-resistant membrane element 230 are all connected to the inlet of the waste liquid tank 440.

[0042] It should be noted that the cleaning tank 410 is suitable for conveying the cleaning solution required for top washing, alkaline washing or chemical cleaning to the first-stage alkali-resistant membrane element 210, the second-stage alkali-resistant membrane element 220 and the third-stage alkali-resistant membrane element 230. When cleaning is required, the corresponding first control valve 610 should be closed. During the cleaning process, the cleaning solution flowing through the first-stage alkali-resistant membrane element 210, the second-stage alkali-resistant membrane element 220 and the third-stage alkali-resistant membrane element 230 flows back to the cleaning tank 410 through the permeate outlet and can be reused for cleaning, reducing cleaning solution waste and lowering cleaning costs. The wastewater generated after rinsing is discharged into the waste liquid tank 440 for centralized treatment through the concentrate outlet.

[0043] Furthermore, it also includes two or more second control valves 620, which are respectively installed at the permeate cleaning return outlet, the concentrate cleaning return outlet, and the input end of the first-stage circulating pump 211 of the first-stage alkali-resistant membrane element 210. Specifically, the permeate cleaning return outlet of the first-stage alkali-resistant membrane element 210 is connected to the input end of the second control valve 620, the output end of the second control valve 620 is connected to the first inlet of the cleaning tank 410, the concentrate cleaning return outlet of the first-stage alkali-resistant membrane element 210 is connected to the input end of the second control valve 620, the output end of the second control valve 620 is connected to the inlet of the waste liquid tank 440, the input end of the second control valve 620 is connected to the conveying end of the cleaning tank 410, and the output end of the second control valve 620 is connected to the input end of the first-stage circulating pump 211.

[0044] Furthermore, two or more second control valves 620 are respectively installed at the permeate cleaning return outlet, the concentrate cleaning return outlet, and the input end of the second-stage alkali-resistant membrane element 220; specifically, the input end of the second control valve 620 is connected to the conveying end of the cleaning tank 410, the output end of the second control valve 620 is connected to the input end of the second-stage circulating pump 221, the permeate cleaning return outlet of the second-stage alkali-resistant membrane element 220 is connected to the input end of the second control valve 620, the output end of the second control valve 620 is connected to the first inlet of the cleaning tank 410, the concentrate cleaning return outlet of the second-stage alkali-resistant membrane element 220 is connected to the input end of the second control valve 620, and the output end of the second control valve 620 is connected to the inlet of the waste liquid tank 440.

[0045] Furthermore, two or more second control valves 620 are respectively installed at the permeate cleaning return outlet, the concentrate cleaning return outlet, and the input end of the three-stage alkali-resistant membrane element 230; a second control valve 620 is installed at the inlet of the waste liquid tank 440. Specifically, the input end of the second control valve 620 is connected to the conveying end of the cleaning tank 410, the output end of the second control valve 620 is connected to the input end of the three-stage circulating pump 231, the permeate cleaning return outlet of the three-stage alkali-resistant membrane element 230 is connected to the input end of the second control valve 620, the output end of the second control valve 620 is connected to the first inlet of the cleaning tank 410, the concentrate cleaning return outlet of the three-stage alkali-resistant membrane element 230 is connected to the input end of the second control valve 620, and the output end of the second control valve 620 is connected to the inlet of the waste liquid tank 440.

[0046] This application can deliver cleaning fluid to a single section or multiple sections simultaneously by controlling the opening or closing of the corresponding second control valve 620 according to the different contamination levels of the alkali-resistant membrane elements, thereby achieving segmented cleaning of the alkali-resistant membrane elements and avoiding system shutdown due to contamination of a single section. It can also adjust the operation in real time according to the actual operating conditions.

[0047] In one possible implementation, the system further includes a cleaning pump 420 and a cleaning filter 430. The delivery end of the cleaning tank 410 is connected to the input end of the cleaning pump 420, the output end of the cleaning pump 420 is connected to the input end of the cleaning filter 430, and the output end of the cleaning filter 430 is connected to the inlet ends of the first-stage alkali-resistant membrane element 210, the second-stage alkali-resistant membrane element 220, and the third-stage alkali-resistant membrane element 230, respectively. It should be noted that the cleaning pump 420 is used to provide power for the delivery of the cleaning solution. The cleaning pump 420 draws and pressurizes the cleaning solution from the cleaning tank 410, ensuring that the cleaning solution can overcome pipeline resistance and be stably delivered to the inlet ends of each alkali-resistant membrane element. This avoids insufficient power causing the cleaning solution to fail to reach the inlet or to flow too slowly, resulting in incomplete cleaning. The cleaning filter 430 is used to trap impurities in the cleaning solution, preventing secondary contamination of the alkali-resistant membrane elements due to impurities carried by the cleaning solution.

[0048] In one possible implementation, a circulation pipeline 500 is provided; the inlet of the circulation pipeline 500 is connected to the permeate outlet of a first-stage alkali-resistant membrane element 210, the permeate outlet of a second-stage alkali-resistant membrane element 220, and the permeate outlet of a third-stage alkali-resistant membrane element 230, respectively, and the outlet of the circulation pipeline 500 is connected to the second inlet of the cleaning tank 410.

[0049] It should be noted that a third control valve 510 is provided on the circulation pipeline 500. The circulation pipeline 500 is designed for chemical cleaning. Chemical cleaning requires the chemical agent to fully react within the alkali-resistant membrane element to remove stubborn impurities. This application sets up the circulation pipeline 500 and the third control valve 510 so that when chemical cleaning of the alkali-resistant membrane treatment system of this application is required, the third control valve 510 is opened and the first control valve 610 and the second control valve 620 at the inlet of the waste liquid tank 440 are closed, so that a circulation system is formed between the cleaning tank 410, the first alkali-resistant membrane element 210, the second alkali-resistant membrane element 220, the third alkali-resistant membrane element 230, and the circulation pipeline 500. This allows the chemical cleaning solution output from the cleaning tank 410 to repeatedly rinse and soak the first alkali-resistant membrane element 210, the second alkali-resistant membrane element 220, and the third alkali-resistant membrane element 230. After cleaning is completed, the chemical agent in the cleaning tank 410 can be replaced with a conventional cleaning solution.

[0050] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. An alkali-resistant membrane treatment system, characterized in that, include: Raw material tank, purified liquid tank, concentration tank, first-stage alkali-resistant membrane element, second-stage alkali-resistant membrane element and third-stage alkali-resistant membrane element; The outlet of the raw material tank is connected to the inlet of the first-stage alkali-resistant membrane element, the permeate outlet of the first-stage alkali-resistant membrane element is connected to the inlet of the purified liquid tank, and the concentrate outlet of the first-stage alkali-resistant membrane element is connected to the inlet of the second-stage alkali-resistant membrane element. The permeate outlet of the second-stage alkali-resistant membrane element is connected to the feed inlet of the raw material tank, the concentrate outlet of the second-stage alkali-resistant membrane element is connected to the feed end of the third-stage alkali-resistant membrane element, and the concentrate outlet of the second-stage alkali-resistant membrane element is connected to the feed end of the second-stage alkali-resistant membrane element through the first reflux pipeline. The permeate outlet of the three-section alkali-resistant membrane element is connected to the feed inlet of the raw material tank, the concentrate outlet of the three-section alkali-resistant membrane element is connected to the feed inlet of the concentration tank, and the concentrate outlet of the three-section alkali-resistant membrane element is connected to the feed inlet of the three-section alkali-resistant membrane element through a second reflux pipeline.

2. The alkali-resistant membrane treatment system according to claim 1, characterized in that, It also includes a pre-processing conveying unit; The raw material tank is connected to the feed end of the alkali-resistant membrane element through the pretreatment conveying unit.

3. The alkali-resistant membrane treatment system according to claim 2, characterized in that, The pretreatment conveying unit includes: a feed pump, a security filter, and a high-pressure pump; The input end of the feed pump is connected to the outlet of the raw material tank, the output end of the feed pump is connected to the input end of the security filter, the output end of the security filter is connected to the input end of the high-pressure pump, and the output end of the high-pressure pump is connected to the feed end of the alkali-resistant membrane element.

4. The alkali-resistant membrane treatment system according to claim 3, characterized in that, Also includes: Single-stage circulating pump, two-stage circulating pump and three-stage circulating pump; The input end of the circulating pump is connected to the output end of the high-pressure pump, and the output end of the circulating pump is connected to the feed end of the alkali-resistant membrane element. The input end of the second-stage circulation pump is connected to the concentrated liquid outlet of the first-stage alkali-resistant membrane element, and the output end of the second-stage circulation pump is connected to the feed end of the second-stage alkali-resistant membrane element. The input end of the three-stage circulating pump is connected to the concentrate outlet of the two-stage alkali-resistant membrane element, and the output end of the three-stage circulating pump is connected to the feed end of the three-stage alkali-resistant membrane element.

5. The alkali-resistant membrane treatment system according to claim 1, characterized in that, The alkali-resistant membrane element is provided in two or more parts; Two or more of the aforementioned alkali-resistant membrane elements are connected in series along the waste alkali liquid conveying direction, and the permeate outlets of the two or more of the aforementioned alkali-resistant membrane elements are all connected to the feed inlet of the purified liquid tank.

6. The alkali-resistant film treatment system according to claim 5, characterized in that, The alkali-resistant membrane element has three components.

7. The alkali-resistant membrane treatment system according to claim 1, characterized in that, Also includes: Cleaning tanks and waste liquid tanks; The conveying end of the cleaning tank is connected to the feed end of the first alkali-resistant membrane element, the feed end of the second alkali-resistant membrane element, and the feed end of the third alkali-resistant membrane element, respectively. The permeate cleaning return outlet of the first alkali-resistant membrane element, the permeate cleaning return outlet of the second alkali-resistant membrane element, and the permeate cleaning return outlet of the third alkali-resistant membrane element are all connected to the first inlet of the cleaning tank. The concentrated cleaning reflux outlets of the first-stage alkali-resistant membrane element, the second-stage alkali-resistant membrane element, and the third-stage alkali-resistant membrane element are all connected to the inlet of the waste liquid tank.

8. The alkali-resistant membrane treatment system according to claim 7, characterized in that, Also includes: Cleaning pump and cleaning filter; The conveying end of the cleaning tank is connected to the input end of the cleaning pump, the output end of the cleaning pump is connected to the input end of the cleaning filter, and the output end of the cleaning filter is connected to the feed end of the first alkali-resistant membrane element, the feed end of the second alkali-resistant membrane element, and the feed end of the third alkali-resistant membrane element, respectively.

9. The alkali-resistant film treatment system according to claim 7, characterized in that, Also includes: Circulation piping; The inlet of the circulation pipeline is connected to the permeate outlet of the first alkali-resistant membrane element, the permeate outlet of the second alkali-resistant membrane element, and the permeate outlet of the third alkali-resistant membrane element, respectively. The outlet of the circulation pipeline is connected to the second inlet of the cleaning tank.

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