CN110960986A - Environment-friendly reverse osmosis cleaning device and method - Google Patents
Environment-friendly reverse osmosis cleaning device and method Download PDFInfo
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- CN110960986A CN110960986A CN201911240142.4A CN201911240142A CN110960986A CN 110960986 A CN110960986 A CN 110960986A CN 201911240142 A CN201911240142 A CN 201911240142A CN 110960986 A CN110960986 A CN 110960986A
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- reverse osmosis
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
- B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
- B01D61/025—Reverse osmosis; Hyperfiltration
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
- B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
- B01D61/08—Apparatus therefor
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D65/00—Accessories or auxiliary operations, in general, for separation processes or apparatus using semi-permeable membranes
- B01D65/02—Membrane cleaning or sterilisation ; Membrane regeneration
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2321/00—Details relating to membrane cleaning, regeneration, sterilization or to the prevention of fouling
- B01D2321/04—Backflushing
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- Water Supply & Treatment (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Nanotechnology (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
Abstract
The invention discloses an environment-friendly reverse osmosis cleaning device and method, which are characterized in that the reverse osmosis membrane element cleaning device comprises a piston type hydraulic cylinder, the hydraulic cylinder is in a hollow thin-wall cylinder shape, a slidable piston is arranged in the hydraulic cylinder, and the hydraulic cylinder is divided into a salt water chamber and a fresh water chamber by two sides of the piston. The reverse osmosis membrane element cleaning device is simultaneously provided with 4 automatic valves which are respectively a water supply valve at the saline side of a hydraulic cylinder, a water supply valve at the fresh water side of the hydraulic cylinder, a reverse osmosis water production isolating valve and an external discharge valve at the saline side of the hydraulic cylinder. The water pressure cylinder salt water chamber is connected to a water inlet pipeline of the reverse osmosis membrane group through a stainless steel connecting pipe and is isolated or communicated through a water supply valve at the water pressure cylinder salt water side; meanwhile, the brine on the brine side of the hydraulic cylinder can be discharged outwards through the brine discharge valve of the hydraulic cylinder. The fresh water chamber of the hydraulic cylinder is connected to a water production pipeline of the reverse osmosis system through a stainless steel connecting pipe and is isolated or communicated through a fresh water side water replenishing valve of the hydraulic cylinder. And a reverse osmosis water production isolating valve is arranged on a pipeline from the reverse osmosis membrane group water production to the water production collecting unit. When in cleaning, the piston of the hydraulic cylinder is used for transferring pressure and the principle of osmotic pressure is used for leading fresh water to permeate from the water producing side to the water inlet side of the reverse osmosis membrane, and the automatic valve is used for leading the reverse osmosis system to have the function of regular reverse osmosis cleaning, thus leading the polluted reverse osmosis membrane to recover the performance.
Description
Technical Field
The invention relates to an environment-friendly reverse osmosis cleaning device and method, and belongs to the technical field of reverse osmosis cleaning.
Background
At present, the seawater and brackish water desalination technology which is most widely applied all over the world is mainly a membrane reverse osmosis desalination technology, core equipment adopted is a spiral wound reverse osmosis membrane, seawater or brackish water to be treated flows through the surface of the reverse osmosis membrane after being pressurized to a certain pressure by a high pressure pump, water molecules can permeate through the reverse osmosis membrane, components such as organic matters, bacteria, viruses and most inorganic salts can be intercepted by the reverse osmosis membrane, the desalination and purification of feed water are realized, and fresh water permeating through the reverse osmosis membrane can meet the production and living requirements of human beings.
When the reverse osmosis system operates, suspended substances, dissolved substances, microorganisms and the like contained in inlet water can cause pollution of membrane elements, and the pollution mainly comprises forms of insoluble salt scaling, colloid and particle fouling, biological fouling and the like. After the membrane element is polluted, the water yield of the system is reduced, the transmembrane pressure difference of the system is increased, the energy consumption is increased, and the normal operation of the system is influenced, and at the moment, measures are required to prevent or relieve the membrane pollution of the system. For conventional membrane products (microfiltration membranes and ultrafiltration membranes), the most important mode for recovering the performance of the conventional membrane products is backwashing, but the backwashing can cause irreversible damage to membrane elements due to the special rolling structure of the spiral-wound reverse osmosis membrane. At present, the cleaning technology is that chemical agents are added, membrane elements are cleaned on the water inlet side of a reverse osmosis membrane, and the cleaning technology comprises the following steps:
1) adding acid into the inlet water to relieve carbonate scaling;
2) adding a scale inhibitor into the inlet water to control the carbonate scaling, the sulfate scaling and the calcium fluoride scaling;
3) washing the surface of the membrane: when the system is stopped for a long time, the surface of the membrane element is washed by adopting low-pressure large-flow inlet water, and pollutants attached to the surface of the membrane are washed away;
4) chemical cleaning: the reverse osmosis membrane is periodically cleaned by chemical solution (mainly acid, alkali, chelating agent and the like) to remove scales and dirt and blockage.
In some remote islands, villages, construction sites and the like, because of the lack of drinkable fresh water resources, a container type small seawater or brackish water desalination system is required to be adopted to purify and desalt local seawater or brackish water so as to meet the daily life needs of people. However, as the membrane element is easy to be polluted, a plurality of chemical agents must be added into the system, and the problems caused by the addition of the chemical agents are as follows: firstly, part of chemical agents are discharged along with concentrated water and cleaning liquid, and adverse effects are generated on the local environment ecology; secondly, chemical agents must be transported to the use site, the transportation cost is extremely high, and the transportation is very inconvenient.
Disclosure of Invention
The invention aims to solve the technical problem of how to clean a membrane element of a reverse osmosis system under the condition of not adding a chemical agent.
In order to solve the technical problems, the technical scheme of the invention is to provide an environment-friendly reverse osmosis cleaning device which is characterized by comprising a reverse osmosis cleaning unit, wherein the reverse osmosis cleaning unit comprises a hydraulic cylinder, the hydraulic cylinder is a piston type hydraulic cylinder, a slidable piston is arranged in the hydraulic cylinder, the hydraulic cylinder is divided into two independent chambers, namely a saline water chamber and a fresh water chamber, two sides of the piston are provided with the hydraulic cylinder, the reverse osmosis cleaning unit also comprises 4 automatic valves, the saline water chamber is communicated with a water inlet pipeline of a reverse osmosis membrane system, and a saline water side water replenishing valve is arranged on a communication passage; the brine chamber is provided with a brine side discharge valve for controlling the discharge of brine; the fresh water chamber is communicated with a water production pipeline of the reverse osmosis membrane system, and a fresh water side water replenishing valve is arranged on the communicated pipeline; and a reverse osmosis water production isolating valve is arranged on the pipeline from the water production of the reverse osmosis membrane system to the water production collecting unit.
Preferably, the hydraulic cylinder and the piston are made of corrosion-resistant stainless steel.
Preferably, the contact part of the piston and the inner wall of the hydraulic cylinder is provided with a slidable rubber sealing ring.
Preferably, the hydraulic cylinder structure is a hollow thin-wall cylinder, the outer diameter is 250mm, and the length is 7.4m for a conventional seawater desalination system; for a conventional brackish water desalination system, the length is 6.4 m.
The technical scheme of the invention also provides an environment-friendly reverse osmosis cleaning method which is characterized in that the environment-friendly reverse osmosis cleaning device is adopted, and the reverse osmosis produced water reversely permeates a reverse osmosis membrane by utilizing the naturally existing osmotic pressure of media at two sides of the reverse osmosis membrane so as to clean the dirt on the surface of the reverse osmosis membrane.
The invention has the beneficial effects that:
1. the adverse effect of the external drainage of the reverse osmosis system on the external environment is reduced;
2. the system operation cost (mainly the medicament purchase and transportation cost in remote areas) is reduced;
3. the system investment cost (mainly including cleaning a water pump, a water tank, a security filter and the like) is reduced;
4. the reverse osmosis system can realize automatic cleaning without stopping, and the start-stop operation of the system is reduced.
Drawings
Fig. 1 is a schematic diagram illustrating the operation of the environmentally friendly reverse osmosis cleaning apparatus and method provided in this embodiment.
Detailed Description
In order to make the invention more comprehensible, preferred embodiments are described in detail below with reference to the accompanying drawings.
Examples
The invention relates to an environment-friendly reverse osmosis cleaning device and method, which comprises a reverse osmosis cleaning unit 140, can realize that a system is added without chemical agents, saves the logistics transportation cost of the chemical agents, can also reduce the influence of the system discharge on the environment to the maximum extent, and is particularly suitable for reverse osmosis systems in remote areas. The structure of the invention is expressed as follows, the reverse osmosis cleaning unit 140 comprises a piston type hydraulic cylinder 141, and corresponding corrosion-resistant stainless steel is selected as the material of the hydraulic cylinder and the piston according to different salinity of the treated water. The hydraulic cylinder 141 is designed in a hollow thin-wall cylindrical shape, a slidable piston 143 is arranged in the hydraulic cylinder 141, and two sides of the piston 143 divide the hydraulic cylinder 141 into two independent chambers, namely a salt water chamber 142 and a fresh water chamber 144. The contact part of the piston 143 and the inner wall of the hydraulic cylinder 141 is provided with a slidable rubber sealing ring to ensure that chamber water systems on both sides of the piston 143 are separated. According to the length and the outer diameter of the reverse osmosis membrane pressure container, the appearance of the hydraulic cylinder 141 is designed to be similar in size, and for a seawater desalination system, the length is preferably 7.4 m; for a brackish water desalination system, the length is preferably 6.4 m; the outer diameter is preferably 250 mm; the hydraulic cylinder 141 and the reverse osmosis membrane system 130 may be disposed on the frame as a unit. The reverse osmosis cleaning unit 140 is also equipped with 4 automatic valves, which are a brine side water replenishing valve 145, a fresh water side water replenishing valve 146, a reverse osmosis water production blocking valve 147 and a brine side drain valve 148, respectively. The brine chamber 142 is connected to the water inlet line 120 of the reverse osmosis membrane system 130 through a stainless steel adapter tube, and is isolated or communicated through a brine side water replenishing valve 145; meanwhile, the brine chamber 142 discharges the brine of the brine chamber 142 outwards through the brine discharge valve 148, and the discharge is designed to be a non-back pressure design. The fresh water chamber 144 is connected to the water production line of the reverse osmosis membrane system 130 through a stainless steel adapter tube, and is isolated or communicated through a fresh water side water replenishing valve 146. The pipeline from the reverse osmosis membrane system 130 to the produced water collecting unit 149 is provided with an automatic valve reverse osmosis produced water isolating valve 147.
As shown in fig. 1, the reverse osmosis membrane system 130 is operated in an initial stage without salt water and fresh water in the hydraulic cylinder 141. The brine side water replenishing valve 145 is closed, and the fresh water side water replenishing valve 146, the reverse osmosis water production blocking valve 147 and the brine side drain valve 148 are opened. After the reverse osmosis membrane system 130 enters the initial water preparation stage, the fresh water enters the fresh water chamber 144 through the valve fresh water side water replenishing valve 146, the piston 143 is pushed to slide until the saline water chamber 142 is compressed to the minimum, the fresh water chamber 144 is full of the fresh water, the fresh water side water replenishing valve 146 and the saline water side external drain valve 148 are closed at this time, and the reverse osmosis membrane system 130 enters the normal water preparation stage.
When the transmembrane pressure difference of the reverse osmosis membrane system 130 reaches a set cleaning value, or the operation time of the reverse osmosis membrane system 130 reaches a set value, the reverse osmosis cleaning unit 140 starts to operate. The reverse osmosis produced water blocking valve 147 is closed while the brine side water replenishing valve 145 and the fresh water side water replenishing valve 146 are slowly opened. The high pressure inlet water of the inlet line 120 of the reverse osmosis membrane system 130 enters the brine chamber 142 through the brine side water replenishing valve 145, the pressure is transferred to the piston 143, and the piston 143 transfers the pressure to the fresh water in the fresh water chamber 144, so that the pressure of the fresh water is increased until the pressure is slightly lower than the inlet water of the reverse osmosis membrane system 130. Because the sliding friction coefficient between the piston 143 and the inner wall of the hydraulic cylinder 141 is very small, the pressures of the water inlet side and the water outlet side of the reverse osmosis membrane are almost equal, and the salt content of the water inlet side of the reverse osmosis membrane is much higher than that of the water outlet side, according to the basic principle of osmotic pressure, the osmotic pressure of the fresh water in the fresh water chamber 144 is higher than that of the salt water at the water inlet side of the reverse osmosis membrane, the fresh water spontaneously flows to the concentrated water side from the fresh water side through the reverse osmosis membrane, the crystallized salt, the granular dirt and the biological dirt on the surface of the reverse osmosis membrane element are washed away, and the washed dirt is discharged out of the. In the process, the piston 143 slides to the right. When the saline chamber 142 is filled with high pressure saline and the fresh water chamber 144 is fully compressed, the saline side make-up valve 145 is closed and the reverse osmosis cleaning process is complete. And (3) opening the reverse osmosis produced water blocking valve 147 and the brine side external discharge valve 148, restarting the system to initially produce water, enabling the produced water to enter the fresh water chamber 144 through the fresh water side water replenishing valve 146, pushing the piston 143 to move leftwards, and discharging the brine in the brine chamber 142 on the left side of the piston 143 out of the hydraulic cylinder 141. When the fresh water chamber 144 is again filled with fresh water, the fresh water side make-up valve 146 and the brine side drain valve 148 are closed, and the reverse osmosis cleaning unit 140 enters a normal water production state until the next cleaning cycle begins.
The reverse osmosis cleaning unit 140 is used to periodically reverse osmosis clean the membrane elements to wash away the foulants accumulated on the membrane surface. According to the differences of the water quality of inlet water, reverse osmosis pressure, reverse osmosis flux, reverse osmosis duration and the like, the operation periods of reverse cleaning systems are also different and need to be formulated according to actual project conditions.
The reverse osmosis cleaning technology is initiatively adopted, no chemical agent is required to be added into the system, the membrane element is not cleaned on the water inlet side of the reverse osmosis membrane, but fresh water produced by the system is periodically utilized to reversely permeate the reverse osmosis membrane to wash away dirt accumulated on the surface of the membrane element, so that the dirt is discharged along with concentrated solution of the system, the traditional agent cleaning mode can be effectively replaced, the reverse osmosis membrane element can be stably operated for a long time, the agent transportation cost is saved, and the reverse osmosis cleaning technology is friendly to the external environment and has no adverse effect.
The technology is suitable for the field of reverse osmosis desalination of seawater and brackish water, is particularly suitable for maintainable cleaning of a container type reverse osmosis desalination system, ensures that dirt accumulated on a membrane element of the reverse osmosis system is removed periodically, is beneficial to long-time stable operation of the reverse osmosis membrane system, and greatly reduces adverse effects of the system on the external environment.
Claims (5)
1. An environment-friendly reverse osmosis cleaning device and method are characterized by comprising a reverse osmosis cleaning unit (140), wherein the reverse osmosis cleaning unit (140) comprises a hydraulic cylinder (141), the hydraulic cylinder (141) is a piston type hydraulic cylinder, a slidable piston (143) is arranged in the hydraulic cylinder, the hydraulic cylinder (141) is divided into two independent chamber salt water chambers (142) and a fresh water chamber (144) by two sides of the piston (143), the reverse osmosis cleaning unit (140) further comprises 4 automatic valves, the salt water chambers (142) are communicated with a water inlet pipeline (120) of a reverse osmosis membrane system (130), and a salt water side water replenishing valve (145) is arranged on a communicating passage; the brine chamber (142) is provided with a brine side discharge valve (148) for controlling the discharge of brine; the fresh water chamber (144) is communicated with a water production pipeline of the reverse osmosis membrane system (130), and a fresh water side water replenishing valve (146) is arranged on the communication pipeline; a reverse osmosis water production isolating valve (147) is arranged on a pipeline from the reverse osmosis membrane system (130) to the water production collecting unit (149).
2. The environmentally friendly reverse osmosis cleaning apparatus and method of claim 1, wherein the hydraulic cylinder (141) and the piston (143) are made of corrosion resistant stainless steel.
3. The environmentally friendly reverse osmosis cleaning apparatus and method of claim 1, wherein the piston (143) is provided with a slidable rubber sealing ring at the contact portion with the inner wall of the hydraulic cylinder (141).
4. The environment-friendly reverse osmosis cleaning device and method as claimed in claim 1, wherein the hydraulic cylinder (141) has a hollow thin-walled cylinder shape, an outer diameter of 250mm, and a length of 7.4m for a conventional seawater desalination system; for a conventional brackish water desalination system, the length is 6.4 m.
5. An environment-friendly reverse osmosis cleaning method, characterized in that the cleaning of the dirt on the surface of the reverse osmosis membrane is realized by using the environment-friendly reverse osmosis cleaning device and method of claim 1 and making reverse osmosis produced water reversely permeate through the reverse osmosis membrane by utilizing the naturally existing osmotic pressure of media at two sides of the reverse osmosis membrane.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911240142.4A CN110960986A (en) | 2019-12-06 | 2019-12-06 | Environment-friendly reverse osmosis cleaning device and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911240142.4A CN110960986A (en) | 2019-12-06 | 2019-12-06 | Environment-friendly reverse osmosis cleaning device and method |
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| Publication Number | Publication Date |
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| CN110960986A true CN110960986A (en) | 2020-04-07 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911240142.4A Withdrawn CN110960986A (en) | 2019-12-06 | 2019-12-06 | Environment-friendly reverse osmosis cleaning device and method |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112473374A (en) * | 2020-11-06 | 2021-03-12 | 张梅 | Semipermeable membrane desalination device and method with bidirectional forward osmosis online cleaning function |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1142902B (en) * | 1980-10-20 | 1986-10-15 | Stanford Res Inst Int | PROCEDURE AND PUMP-MOTOR EQUIPMENT FOR FLUIDS WITH ENERGY RECOVERY |
| CN1686848A (en) * | 2005-04-29 | 2005-10-26 | 国家海洋局天津海水淡化与综合利用研究所 | Reverse osmosis desalinization system capable of on-line back washing |
| CN2780743Y (en) * | 2005-04-29 | 2006-05-17 | 国家海洋局天津海水淡化与综合利用研究所 | Reverse osmosis desalting device capable of on-line back-flashing |
| US9233340B1 (en) * | 2015-01-13 | 2016-01-12 | Renergy Technologies Ltd. | Cylinder arrangement and method of use for energy recovery with seawater desalination |
-
2019
- 2019-12-06 CN CN201911240142.4A patent/CN110960986A/en not_active Withdrawn
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1142902B (en) * | 1980-10-20 | 1986-10-15 | Stanford Res Inst Int | PROCEDURE AND PUMP-MOTOR EQUIPMENT FOR FLUIDS WITH ENERGY RECOVERY |
| CN1686848A (en) * | 2005-04-29 | 2005-10-26 | 国家海洋局天津海水淡化与综合利用研究所 | Reverse osmosis desalinization system capable of on-line back washing |
| CN2780743Y (en) * | 2005-04-29 | 2006-05-17 | 国家海洋局天津海水淡化与综合利用研究所 | Reverse osmosis desalting device capable of on-line back-flashing |
| US9233340B1 (en) * | 2015-01-13 | 2016-01-12 | Renergy Technologies Ltd. | Cylinder arrangement and method of use for energy recovery with seawater desalination |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112473374A (en) * | 2020-11-06 | 2021-03-12 | 张梅 | Semipermeable membrane desalination device and method with bidirectional forward osmosis online cleaning function |
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