Views: 0 Author: Guangzhou YALIAN Machinery Publish Time: 2023-04-10 Origin: Guangzhou YALIAN Machinery
How to choose reverse osmosis water filter system?
And 10 common problems and solutions of reverse osmosis membrane treatment technology in water filter
Introduction of reverse osmosis water filter system
Reverse osmosis pure water equipment takes out the water resistivity through the reverse osmosis membrane method: the water quality is between 0.5-18MΩ cm. The reverse osmosis membrane in the equipment can use the polymer membrane to separate substances, and can remove more than 90% of the water containing More than 99% of the dissolved salts are colloids.
The following introduces the functions of the reverse osmosis pure water system adopted by the reverse osmosis pure water equipment:
The reverse osmosis water filter system adopted by the reverse osmosis pure water equipment has advanced water treatment technology, can carry out two-stage reverse osmosis advanced treatment technology, has automatic flushing function, and can realize PLC programmable intelligent control system.
Reverse osmosis water filter system technology: reverse osmosis pure water equipment can directly convert tap water into pure water and ultrapure water, which is used in industrial production water, food processing water and various laboratory water, the water quality of the effluent and the water used per hour The quantity can be customized according to the requirements of the enterprise.
The reverse osmosis pure water system can adopt advanced pretreatment of source water, EDI technology, reverse osmosis, conventional mixed bed, ultrafiltration, microfiltration and other processes.
Two-stage reverse osmosis: The hardness of raw water in different regions is different. The use of two-stage reverse osmosis system can make the desalination rate higher and the service life of its equipment longer. The pure water produced is used as the influent of the EDI system , will help EDI equipment to run in the best state, effectively reduce operating costs and prolong the service life of EDI.
Automatic flushing function: equipment flushing is divided into automatic and manual, automatic form: the system will flush the primary reverse osmosis membrane every time the equipment runs for one hour, and then flush the secondary reverse osmosis membrane once after flushing.
PLC programmable intelligent control system: LCD liquid crystal display Chinese display, man-machine interface operating system, man-machine dialogue function, clock and language setting function, automatic detection of electric control system after starting up, fully automatic Make water.
During the operation of the equipment, the water storage bucket will store water. Even if the water is cut off or the water pressure is not enough, the pure water system itself will perform a power-off shutdown protection function.
How to choose reverse osmosis water filter system?
With the continuous innovation of technology, the equipment on the market is becoming more and more diverse. Without experience, consumers cannot distinguish the quality of their own equipment. Faced with so many choices, how should we choose a suitable set? What about reverse osmosis water treatment equipment?
According to YALIAN MACHINERY's understanding of the water treatment process, the pure water produced by a good set of reverse osmosis water treatment equipment can meet the industrial water standards. Of course, not all industries need to use reverse osmosis equipment, and water treatment equipment It's not that the more expensive the better, the so-called one that suits you is the most important thing.
Buyers can consider water treatment from the following aspects:
1. Raw water quality: The raw water quality of the water treatment equipment should be understood first. It is best to do a good job in the detection of the raw water first to understand the conductivity, turbidity, calcium ions, magnesium ions, iron ions, manganese ions, and hardness of the raw water. wait. the
2. Pure water volume: Pure water equipment is customized according to the water output per hour (the conductivity of treated pure water such as water that has not been used for a long time will be affected to a certain extent), so you must clearly understand your own water production , according to their own production to determine the amount of water. the
3. The place where the equipment is placed: because the greater the water output requirement of the equipment, the larger the area occupied by the equipment, so it needs to be customized according to the actual situation. the
4. Operating costs: The required effluent quality requirements are different, and the water treatment processes used are different, so the water treatment chemicals used during operation are different. the
5. After-sales service: Many manufacturers do not provide after-sales service for the equipment, but once there is a problem with the equipment, there is no one to deal with it, so after-sales service is very important. the
The above are some suggestions on how to choose a suitable reverse osmosis water filter system listed by the editor. If you have any questions, go directly to YALIAN MACHINERY
amanda@yalianmachine.com
10 common problems and solutions of reverse osmosis membrane treatment technology in water filter
In general, when the standardized flux decreases by 10-15%, or the system desalination rate decreases by 10-15%, or the operating pressure and inter-stage pressure difference increase by 10-15%, the RO system should be cleaned. The cleaning frequency is directly related to the degree of system pretreatment. When SDI15<3, the cleaning frequency may be 4 times a year; when SDI15 is around 5, the cleaning frequency may be doubled, but the cleaning frequency depends on each item actual situation on site.
1. How often should the reverse osmosis system be cleaned?
In general, when the standardized flux decreases by 10-15%, or the system desalination rate decreases by 10-15%, or the operating pressure and inter-stage pressure difference increase by 10-15%, the RO system should be cleaned. The cleaning frequency is directly related to the degree of system pretreatment. When SDI15<3, the cleaning frequency may be 4 times a year; when SDI15 is around 5, the cleaning frequency may be doubled, but the cleaning frequency depends on each item actual situation on site.
2. What is SDI?
At present, the best possible technique for evaluating colloidal pollution in RO/NF system feed water is to measure the sediment density index (SDI, also known as fouling index) of feed water, which is an important parameter that must be determined before RO design. During the operation of RO/NF, measurements must be made periodically (2 to 3 times a day for surface water), and ASTM D4189-82 specifies the standard for this test. The water inlet regulation of the membrane system is that the SDI15 value must be ≤5. Effective technologies for reducing SDI pretreatment include multi-media filter, ultrafiltration, microfiltration, etc. Adding polydielectrics prior to filtration can sometimes enhance the physical filtration described above, reducing the SDI value.
3. Generally, should reverse osmosis process or ion exchange process be used for water inflow?
Under many influent conditions, it is technically feasible to use ion exchange resin or reverse osmosis, and the choice of process should be determined by economic comparison. Generally speaking, the higher the salt content, the more economical reverse osmosis is. The lower the amount, the more economical is the ion exchange. Due to the popularization of reverse osmosis technology, the combined process of reverse osmosis + ion exchange process or multi-stage reverse osmosis or reverse osmosis + other deep desalination technology has become a recognized technical and economical water treatment solution. Yes, please consult your water treatment engineering company representative. 4. How many years can reverse osmosis membrane elements generally be used for? The service life of the membrane depends on the chemical stability of the membrane, the physical stability of the element, cleanability, influent water source, pretreatment, cleaning frequency, operation and management level, etc. According to economic analysis, it is usually more than 5 years.
4. How many years can reverse osmosis membrane elements generally be used for?
The service life of the membrane depends on the chemical stability of the membrane, the physical stability of the components, the cleanability, the water source, pretreatment, cleaning frequency, operation management level, etc. According to economic analysis, it is usually more than 5 years.
5. What is the difference between reverse osmosis and nanofiltration?
Nanofiltration is a membrane liquid separation technology between reverse osmosis and ultrafiltration. Reverse osmosis can remove the smallest solute with a molecular weight of less than 0.0001 micron, and nanofiltration can remove solutes with a molecular weight of about 0.001 micron. Nanofiltration is essentially a low-pressure reverse osmosis, which is used in occasions where the purity of the water produced after treatment is not particularly strict. Nanofiltration is suitable for treating well water and surface water. Nanofiltration is suitable for water treatment systems that do not need a high desalination rate like reverse osmosis, but has a high ability to remove hardness components, sometimes called "softening membrane". The operating pressure of the nanofiltration system is low and the energy consumption is lower than Corresponding reverse osmosis system.
6. What is the separation capability of membrane technology?
Reverse osmosis is currently the most sophisticated liquid filtration technology. The reverse osmosis membrane intercepts inorganic molecules such as soluble salts and organic substances with a molecular weight greater than 100. On the other hand, water molecules can freely pass through the reverse osmosis membrane. Typical soluble The removal rate of salt is >95-99%. The operating pressure ranges from 7bar (100psi) when the feed water is brackish to 69bar (1,000psi) when the water is seawater. Nanofiltration can remove impurities with a particle size of 1nm (10 angstroms) and organic matter with a molecular weight greater than 200-400. The removal rate of dissolved solids is 20-98%, and the removal rate of salts containing monovalent anions (such as NaCl or CaCl2) is 20-80%, while the removal rate of salt containing divalent anions (such as MgSO4) is higher, which is 90-98%. Ultrafiltration has a separation effect on macromolecules larger than 100-1,000 Angstroms (0.01-0.1 microns). All soluble salts and small molecules can pass through the ultrafiltration membrane, and the substances that can be removed include colloids, proteins, microorganisms and macromolecular organic substances. Most ultrafiltration membranes have a molecular weight cut-off of 1,000 to 100,000. Microfiltration removes particles in the range of about 0.1 to 1 micron. Usually, suspended solids and large particle colloids can be retained while macromolecules and soluble salts are retained.
7. Who sells membrane cleaners or provides cleaning services?
Water treatment companies can provide special membrane cleaning agents and cleaning services, and users can purchase cleaning agents for membrane cleaning according to the recommendations of membrane companies or equipment suppliers.
8. What is the maximum allowable silica concentration in the feed water of the reverse osmosis membrane?
The maximum allowable concentration of silica depends on temperature, pH value and scale inhibitor. Usually, the maximum allowable concentration at the concentrated water end is 100ppm when no scale inhibitor is added. Some scale inhibitors can allow the highest concentration of silica in concentrated water 240ppm, please consult the antiscalant supplier.
9. How does chromium affect RO membranes?
Some heavy metals such as chromium will catalyze the oxidation of chlorine, which will cause the irreversible performance degradation of the diaphragm. This is because Cr6+ is less stable than Cr3+ in water. It seems that metal ions with high oxidation valence have stronger destructive effect. Therefore, the concentration of chromium should be reduced or at least Cr6+ should be reduced to Cr3+ in the pretreatment part.
10. What kind of pretreatment is generally required for RO systems?
The usual pretreatment system consists of the following, coarse filtration (~80 microns) to remove large particles, adding oxidizing agents such as sodium hypochlorite, then performing precision filtration through a multimedia filter or clarification tank, adding sodium bisulfite to reduce residual chlorine and other oxidizing agents, Finally, install a security filter before the high pressure pump inlet. As the name suggests, the function of the security filter is as the final insurance measure to prevent accidental large particles from damaging the impeller and membrane of the high-pressure pump.
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