Reverse osmosis membrane cleaning and repairing coupling system

Abstract

The utility model provides a reverse osmosis membrane cleaning and repairing coupling system which comprises a water tank, a chemical tank A, a chemical tank B, a membrane component, a water inlet pump, a security filter, a high-pressure pump, a bypass pipe A, a bypass pipe B, a concentrated water pipe and a water production pipe, water outlets of the water tank, the chemical tank A and the chemical tank B are connected to the water inlet pump; an outlet of the water inlet pump is respectively connected with the security filter and a bypass pipe A; the bypass pipe A is connected back to the medicament box A and the medicament box B; an outlet of the security filter is respectively connected with a high-pressure pump and a bypass pipe B; the bypass pipe B is connected with the membrane component; an outlet of the high-pressure pump is connected with the membrane component; one branch of the outlet of the membrane module is connected with the medicament box A and the medicament box B through a concentrated water pipe, and the other branch is connected with a water producing pipe. The utility model relates to a coupling system with membrane cleaning and membrane repairing functions, which can fully meet the requirements of on-line membrane cleaning and repairing, and solves the problems of poor effect and lower efficiency of the conventional off-line membrane cleaning and repairing at present.

Description

TECHNICAL FIELD

[0001] The utility model relates to reverse osmosis membrane water treatment field, especially a kind of reverse osmosis membrane cleaning and repair coupling system. BACKGROUND

[0002] Reverse osmosis membrane separation technology is a kind of pressure-driven and hydrophilic membrane is used to separate ions in water to extract pure water technical means.Currently, reverse osmosis membrane has been widely used in seawater desalination, wastewater advanced treatment, brackish water reuse, large boiler makeup water, drinking water, industrial pure water and other fields.However, the service life of membrane depends on the operation of pretreatment device and the operation, maintenance and cleaning mode of membrane.In relatively harsh industrial environment, the service life of reverse osmosis membrane is often only a few months, and in strong acid, strong alkali environment, the solvent / volatility of soluble reverse osmosis membrane layer, high concentration of organic matter or oxidant will further shorten the service life of membrane.

[0003] The demand for reverse osmosis membrane drives the recycling of waste membranes to achieve the goal of resource recycling and sustainable development.Currently, waste reverse osmosis membranes are treated as solid waste, compared with which, repairing and recycling waste reverse osmosis membranes and extending their service life is undoubtedly a more scientific and necessary treatment method.However, current reverse osmosis membrane repair devices generally need offline repair and generally have the problems of relatively complex process repair steps, poor effect and low efficiency. SUMMARY

[0004] In view of the above problems, the utility model provides a kind of reverse osmosis membrane cleaning and repair coupling system to solve the problems of offline cleaning and repair membrane low efficiency, poor effect.

[0005] The technical scheme of the utility model is as follows:

[0006] A kind of reverse osmosis membrane cleaning and repair coupling system, characterized by comprising: water tank for containing reverse osmosis water, medicament tank A for containing pickling agent or polyanion electrolyte agent, medicament tank B for containing alkali washing agent or polycation electrolyte agent, membrane assembly for cleaning and repairing membrane, and water inlet pump, security filter, high-pressure pump, side pipe A, side pipe B, concentrated water pipe and water production pipe;

[0007] The water outlet of the water tank, medicament tank A and medicament tank B is connected to the water inlet pump;One branch of the outlet of the water inlet pump is connected to the security filter, and the other branch is connected back to medicament tank A and medicament tank B through side pipe A;

[0008] One branch of the outlet of the security filter is connected to the high-pressure pump, and the other branch is connected to the membrane module through bypass pipe B; the outlet of the high-pressure pump is connected to the membrane module; one branch of the outlet of the membrane module is connected back to the reagent tank A and the reagent tank B through the concentrated water pipe, and the other branch is connected to the product water pipe as a product water outlet.

[0009] Further, a pressure gauge, a flow meter and an electric conductivity gauge are arranged on the connecting pipe between the high-pressure pump and the membrane module; a pressure gauge, a flow meter and an electric conductivity gauge are arranged on the pipe of the product water pipe; a flow meter and an electric conductivity gauge are arranged on the pipe of the concentrated water pipe.

[0010] Further, a valve is arranged at the inlet and outlet of the water tank; a valve is arranged at the outlet of the reagent tank A and the reagent tank B, and at the inlet of the reagent tank A and the reagent tank B connected to the concentrated water pipe.

[0011] Further, a valve is arranged at the branch outlet of the membrane module connected to the concentrated water pipe, and at the branch outlet of the membrane module connected to the product water pipe.

[0012] Further, a stirrer is arranged inside the reagent tank A and the reagent tank B.

[0013] When the membrane is cleaned, the acid cleaning reagent and the alkali cleaning reagent for cleaning the membrane are respectively prepared and stored in the reagent tank A and the reagent tank B, and the reverse osmosis product water is stored in the water tank.

[0014] The old membrane cleaning process is divided into acid cleaning and alkali cleaning which are performed in sequence. In the acid cleaning process, the acid cleaning reagent in the reagent tank A is adjusted to a suitable pH, then the water inlet pump is started, the reagent passes through the security filter and the bypass pipe B to enter the membrane module, and the concentrated water generated after the cleaning of the membrane module is circulated back to the reagent tank A through the concentrated water pipe; after a certain period of circulation, the membrane module and the reagent tank A are emptied after soaking, and finally the membrane module and the reagent tank A are cleaned with reverse osmosis product water and then emptied. In addition, during the above-mentioned acid cleaning process, part of the product water of the membrane module is discharged to the sewage collection tank through the product water outlet and the product water pipe; the cleaning reagent that does not enter the security filter can be returned to the tank A through the bypass pipe A.

[0015] After the acid cleaning, the membrane is cleaned with alkaline solution. The alkaline cleaning process is as follows: the alkaline cleaning solution in tank B is adjusted to a suitable pH, then the water pump is turned on, the cleaning solution is fed into the membrane module through the security filter and the bypass pipe B, the concentrated solution produced by the membrane module is recycled back to tank B through the concentrated solution pipe, and after a certain period of time, the membrane module and the alkaline cleaning solution in tank B are drained, and then the membrane module is cleaned with RO water and drained. During the above-mentioned alkaline cleaning process, part of the water produced by the membrane module is discharged into the sewage collection tank through the water outlet and the water pipe; the cleaning solution that does not enter the security filter can be returned to tank B through the bypass pipe A.

[0016] After cleaning, the desalination rate and water production of the old membrane are tested. After testing, the polyanion electrolyte solution and the polycation electrolyte solution can be prepared in tanks A and B respectively for subsequent membrane repair.

[0017] The membrane repair method includes high-pressure repair and low-pressure repair. In the high-pressure repair process, the electrolyte solution in tank A or tank B is fed into the membrane module through the water pump, the security filter and the high-pressure pump, and the concentrated solution produced by the membrane module is recycled back to the corresponding tank (A or B) through the concentrated solution pipe; in the low-pressure repair process, the electrolyte solution in tank A or tank B is fed into the membrane module through the water pump, the security filter and the bypass pipe B, and the concentrated solution produced by the membrane module is recycled back to the corresponding tank (A or B) through the concentrated solution pipe. During the above-mentioned high-pressure or low-pressure repair process, part of the water produced by the membrane module is discharged into the sewage collection tank through the water outlet and the water pipe; the electrolyte solution that does not enter the security filter can be returned to the corresponding tank (A or B) through the bypass pipe A.

[0018] The membrane repair process includes polycation electrolyte solution circulation repair and polyanion electrolyte solution circulation repair, which are performed in sequence. Specifically:

[0019] 1) First, the water pump is turned on, and the polycation electrolyte solution in tank B is fed into the membrane module to perform the above-mentioned high-pressure or low-pressure repair circulation, and after a certain period of time of circulation treatment under a certain repair pressure, the polycation electrolyte solution is drained, and the membrane surface is cleaned with RO water to remove excess electrolyte.

[0020] 2) The polyanion electrolyte in tank A is fed into the membrane module to continue the circulation soaking process to modify the membrane surface, and after a certain period of time of circulation treatment under a certain repair pressure, the polyanion electrolyte solution is drained, and the membrane surface is cleaned with RO water to remove excess electrolyte.

[0021] The above-mentioned steps 1) and 2) can be repeated multiple times to achieve the required rejection rate of the reverse osmosis membrane.

[0022] The utility model discloses a kind of coupling systems with membrane cleaning and membrane repair function, can fully meet the demand of online membrane cleaning and repair, solve the problem of poor effect, lower efficiency of current conventional offline cleaning, repair membrane.In addition, the utility model also has the characteristics of simple structure, easy to operate and maintain and low operating cost. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is the overall structure schematic diagram of the utility model.

[0024] Figure 2 It is the comparison of the interception rate of the old reverse osmosis membrane before and after repair of the utility model. DETAILED DESCRIPTION

[0025] As Figure 1 Indicated, the utility model discloses a reverse osmosis membrane cleaning and repair coupling system, comprising: for containing reverse osmosis water tank 1 for containing pickling reagent or polyanion electrolyte reagent reagent tank A2 for containing caustic reagent or polycation electrolyte reagent reagent tank B3 for cleaning and repairing membrane membrane module 9 and water inlet pump 4, security filter 5, high-pressure pump 7, side pipe A 6, side pipe B 8, concentrated water pipe 10 and water production pipe 11;

[0026] The water outlet of water tank 1, reagent tank A2 and reagent tank B3 is connected to water inlet pump 4;One branch of the outlet of water inlet pump 4 is connected to security filter 5, and the other branch of water inlet pump 4 is connected back to reagent tank A2 and reagent tank B3 through side pipe A 6;

[0027] One branch of the outlet of security filter 5 is connected to high-pressure pump 7, and the other branch enters membrane module 9 through side pipe B 8;The outlet of high-pressure pump 7 is connected to membrane module 9;One branch of the outlet of membrane module 9 is connected back to reagent tank A2 and reagent tank B3 through concentrated water pipe 10, and the other branch is connected to water production pipe 11 as water outlet.

[0028] Pressure gauge 12, flow meter 13 and conductivity meter 14 are arranged on the connecting pipeline of high-pressure pump 7 and membrane module 9;Pressure gauge 12, flow meter 13 and conductivity meter 14 are arranged on the pipeline of water production pipe 11;Flow meter 13 and conductivity meter 14 are arranged on the pipeline of concentrated water pipe 10.The determination of pressure gauge 12 on system pipeline can monitor online pressure in real time during membrane cleaning and repair, flow meter 13 can be used for auxiliary control reagent flow of pipeline, and conductivity meter 14 can reflect membrane cleaning and repair condition in real time.

[0029] The water tank 1 is provided with a valve 15 at the water inlet and the water outlet; the medicament tank A2 and the medicament tank B3 are provided with a valve 15 at the water outlet, and the medicament tank A2 and the medicament tank B3 connected with the concentrated water pipe 10 are provided with a valve 15 at the water inlet. The valves at the water inlets and outlets of the water tank and the medicament tank are designed to facilitate the control of the independent circulation process of acid washing, alkali washing, electrolyte repairing and reverse osmosis water cleaning in the membrane repairing process.

[0030] The membrane assembly 9 is provided with a valve 15 at the branch outlet connected with the concentrated water pipe 10, and the membrane assembly 9 is provided with a valve 15 at the branch outlet connected with the water pipe 11. The valve 15 facilitates the control of the fluid flow in the concentrated water pipe 10 and the water pipe 11.

[0031] The medicament tank A2 and the medicament tank B3 are internally provided with a stirrer, so that the stirring and mixing of the medicament in the tank are facilitated.

[0032] The old membrane is cleaned and repaired by using the utility model, and the specific process is as follows:

[0033] 1. Membrane cleaning: the acid washing medicament and the alkali washing medicament used for membrane cleaning are respectively prepared and stored in the medicament tank A2 and the medicament tank B3, and the reverse osmosis water is stored in the water tank 1.

[0034] The membrane cleaning step is divided into acid washing medicament cleaning and alkali washing medicament cleaning. The acid washing step is to first adjust the pH of the acid washing medicament in the medicament tank A2 to 2.0-4.0, then start the water pump 4, and make the medicament enter the membrane assembly 9 through the security filter 5 and the bypass pipe B8, and the concentrated water generated after the membrane assembly 9 is cleaned is circulated back to the medicament tank A2 through the concentrated water pipe 10; after 2-12 hours of circulation, the system is kept still for 2-12 hours of soaking, then the acid washing medicament in the membrane assembly 9 and the medicament tank A2 is emptied, and finally the membrane assembly 9 and the medicament tank A2 are cleaned with reverse osmosis water and then emptied. In addition, in the above-mentioned acid washing process, part of the water produced by the membrane assembly is discharged to the sewage collection tank through the membrane assembly 9 water outlet and the water pipe 11; the acid washing medicament not entering the security filter 5 can be returned to the tank A2 through the bypass pipe A6.

[0035] After the acid cleaning, the membrane is cleaned with alkaline solution. The pH of the alkaline solution in tank B3 is adjusted to 10.0-12.0, and the feed pump 4 is turned on to feed the solution through the security filter 5 and the bypass pipe B8 into the membrane module 9. The concentrated solution produced by the membrane module 9 is recycled back to the tank B3 through the concentrated solution pipe 10. After 2-12 hours of circulation, the solution is allowed to stand for 2-12 hours. Then, the alkaline solution in the membrane module 9 and the tank B3 is drained, and the membrane module 9 is cleaned with the product water produced by the reverse osmosis device. During the alkaline cleaning, part of the product water produced by the membrane module 9 is drained through the product water pipe 11, and the alkaline solution not passing through the security filter 5 is recycled back to the tank B3 through the bypass pipe A6.

[0036] After the cleaning, the desalination rate and the product water production of the old membrane are tested. Then, the polyanion electrolyte solution and the polycation electrolyte solution are prepared in the tanks A2 and B3, respectively, for the subsequent membrane repair.

[0037] 2. Membrane repair: The membrane repair is divided into high-pressure repair and low-pressure repair. In the high-pressure repair, the electrolyte solution in the tank A2 or B3 is fed into the membrane module 9 through the feed pump 4, the security filter 5, and the high-pressure pump 7. The concentrated solution produced by the membrane module 9 is recycled back to the corresponding tank (A or B) through the concentrated solution pipe 10. In the low-pressure repair, the electrolyte solution in the tank A2 or B3 is fed into the membrane module 9 through the feed pump 4, the security filter 5, and the bypass pipe B8. The concentrated solution produced by the membrane module 9 is recycled back to the corresponding tank (A or B) through the concentrated solution pipe 10. During the high-pressure or low-pressure repair, part of the product water produced by the membrane module 9 is drained through the product water pipe 11, and the electrolyte solution not passing through the security filter 5 is recycled back to the corresponding tank (A or B) through the bypass pipe A6.

[0038] The membrane repair is divided into polycation electrolyte solution circulation repair and polyanion electrolyte solution circulation repair, which are performed sequentially. Specifically,

[0039] 1) The polycation electrolyte solution in the tank B3 is fed into the membrane module 9 through the feed pump 4 to perform the high-pressure or low-pressure repair circulation. The repair pressure is controlled to be 1-5 bar, and the circulation treatment time is 5-120 minutes. After the circulation, the polycation electrolyte solution is drained, and the membrane surface is cleaned with the product water produced by the reverse osmosis device.

[0040] 2) continue to circulate the polyanion electrolyte in the medicament tank A2 into the membrane module 9 to carry out the surface modification of the membrane, and the pressure, the circulation treatment time and the standing soaking treatment time are the same as the foregoing step 1), and finally drain the polyanion electrolyte, and wash the excess electrolyte on the membrane surface with the reverse osmosis water.

[0041] Repeat the step 1) and the step 2) at least twice to achieve the required rejection rate of the reverse osmosis membrane.

[0042] The above-mentioned membrane cleaning and repair treatment is used to treat six old membrane samples (A-F) of the industrial water treatment reverse osmosis membrane. The treatment results are shown in Table 1. Figure 2 As shown in Table 1, the rejection rates of the six old membrane samples after the repair are obviously higher than those before the repair, which indicates that the online membrane cleaning and repair of the membrane cleaning / repair coupling system of the utility model can achieve a good repair effect while improving the efficiency.

Claims

1. A reverse osmosis membrane cleaning and repair coupling system, characterized by It comprises: a water tank for containing reverse osmosis water, a reagent tank A for containing acid washing reagent or polyanion electrolyte reagent, a reagent tank B for containing alkali washing reagent or polycation electrolyte reagent, a membrane module for cleaning and repairing the membrane, and a water inlet pump, a security filter, a high-pressure pump, a bypass pipe A, a bypass pipe B, a concentrated water pipe and a water production pipe; the water outlet of the water tank, the reagent tank A and the reagent tank B is connected to the water inlet pump; one branch of the outlet of the water inlet pump is connected to the security filter, and the other branch is connected back to the reagent tank A and the reagent tank B through the bypass pipe A; one branch of the outlet of the security filter is connected to the high-pressure pump, and the other branch is connected to the membrane module through the bypass pipe B; the outlet of the high-pressure pump is connected to the membrane module; one branch of the outlet of the membrane module is connected back to the reagent tank A and the reagent tank B through the concentrated water pipe, and the other branch is connected to the water production pipe as a water outlet.

2. The reverse osmosis membrane cleaning and repair coupling system of claim 1, wherein: A pressure gauge, a flow meter and an electric conductivity meter are arranged on the connecting pipeline between the high-pressure pump and the membrane module; a pressure gauge, a flow meter and an electric conductivity meter are arranged on the pipeline of the water production pipe; a flow meter and an electric conductivity meter are arranged on the pipeline of the concentrated water pipe.

3. The reverse osmosis membrane cleaning and repair coupling system of claim 1 or 2, wherein: Valves are arranged at the water inlet and the water outlet of the water tank; valves are arranged at the water outlet of the reagent tank A and the reagent tank B, and at the water inlet of the reagent tank A and the reagent tank B connected to the concentrated water pipe.

4. The reverse osmosis membrane cleaning and repair coupling system of claim 3, wherein: Valves are arranged at the branch outlet of the membrane module connected to the concentrated water pipe, and at the branch outlet of the membrane module connected to the water production pipe.

5. The reverse osmosis membrane cleaning and repair coupling system of claim 4, wherein: Stirrers are arranged inside the reagent tank A and the reagent tank B.

Images