"Pure water" equipment has been rotating continuously for many years, and the membrane components will be in a bad condition sooner or later, but "out of condition" and "out of condition" are completely different-some dirty things are stuck on the surface, and they can continue to work after washing; some of the diaphragm itself is scrapped from the inside out, no matter how much the potion is soaked, it will be useless, and holding it hard will only make the water get worse and the electricity bill get higher and higher.However, many colleagues in water treatment positions in factories can't tell the difference between these two situations. When they see that the output has fallen, they pour acid-base agents. After spending a lot of money, the membrane hurts faster.Xi'an DIEN Water Treatment has been on the scene for more than ten years, sorting out the distinguishing doorways, life estimation logic, and film replacement judgment criteria into actionable dry goods, and then taking a real project to explain the ins and outs, and help the company to understand the membrane operation and maintenance account.
Reverse osmosis membrane
1. Is it blocked or abandoned?A few tricks of judgment logic visible to the naked eye
Look at the trend of differential pressure
If the pressure difference between the import and export of the first or second stage jumps sharply in a short period of time, and the water output can be seen falling down with the naked eye, but the desalination rate has not deviated much, nine out of ten impurities are pasted on the membrane surface-in this case, after a round of acid-base cleaning, the flux and pressure difference can usually return to 70% or 80%.Conversely, the pressure difference is slowly climbing up, and after the complete washing, the water production and desalination rate are still lying low and motionless. Then it can basically be concluded that the desalination layer of the diaphragm has been irreversible damage, which belongs to the end of life.
Look at the water quality change curve
The fluctuations in water quality caused by blockage are often mild: the conductivity is slightly upturned (click to learn: How much is the standard conductivity of the effluent quality of reverse osmosis equipment normal?), The concentration of impurities at the concentrated water end is high, but it will not continue to deteriorate.Aging is not the case. The conductivity falls in a straight line like a slide, and a series of water channels appear inside the membrane element. No matter how you clean it, you can't pull the indicator back.
2. How long can a film last?DIEN's life accounting logic
The industry usually labels brand new membrane components with a design life of 2 to 3 years, but this is only a number under ideal laboratory conditions.DIEN pushed back based on the project ledger for more than ten years and broke down the variables that affect the life span into three pieces.：
The water source end-municipal tap water and pretreatment is in place, and the diaphragm is safe and dry for three years. The problem is not big; well water and mining areas are high-turbidity and high-mineralization water sources, and the membrane burden is heavy, and the actual cycle is reduced to one and a half to two years; the operating end-frequent switching of machines, the addition of scale inhibitors is increasing and decreasing, and the life span is directly cut by more than 40%.The technical personnel can retrieve the equipment operation log and the monthly water quality report, so that the replacement time window can be delineated in advance, and the sudden membrane change can be turned into planned maintenance.
Reverse osmosis equipment
3. Practical restoration: the truth about the membrane failure of lithium battery supporting factories around Xi'an
In a lithium battery material processing plant on the outskirts of Xi'an, the two-stage reverse osmosis equipment was in operation until the 28th month. The workshop reported that the water output became less and the conductivity became higher. The operation and maintenance team did two rounds of chemical cleaning without improvement. It was determined that it was severely polluted, and continued to increase the concentration of the agent and rinse repeatedly.
After Engineer DIEN arrived at the scene, he first checked the operation records and then measured the differential pressure curve-there was no abnormal surge in the concentrated water pressure difference for a period of time, and the desalination rate increased by less than 5 percentage points before and after cleaning. According to this, it was determined that it was not a blockage, but the overall aging of the diaphragm. Incapacitated.Immediately match the corresponding model membrane element as a whole according to the factory's water volume requirements, and recalibrate the front-end softening parameters at the same time.After the membrane change, the measured water production rose by nearly 30%, and the conductivity steadily fell back to within the process line, saving 120 degrees of electricity in a single day, completely saying goodbye to the previous vicious circle of "washing more and more waste".
4. When do I have to change the film?Four hard red lines
1.Standardized cleaning is done three times, and the water output is still less than 80% of the rated value; 2.The desalination rate decreased by more than 10 percentage points compared to the new film and could not be recovered; 3.Physical damage such as cracks in the membrane shell, bursting of the membrane, and water seepage of the end cap; 4.The diaphragm has suffered from iron ion poisoning or strong oxidant erosion, and the structure has been destroyed; if you touch any one, don't hesitate to replace it directly.
Distinguishing clogging and aging is the first step in controlling the operation and maintenance costs of water treatment.Xi'an DIEN Water Treatment provides a full chain of services from on-site diagnosis, life estimation, cleaning plan formulation to membrane element replacement. At the same time, it helps enterprises suppress the source of membrane pollution from the pretreatment end, so that every membrane element is used on the blade to ensure the long-term stable operation of industrial pure water systems.
