RO reverse osmosis membrane cleaning plan

RO reverse osmosis membrane is the core of industrial water purifiers and is currently the world's most advanced technology for filtering and purifying water. At present, domestic manufacturers of Water filter water purifiers mainly rely on imports, and domestic technology is still unable to produce. Domestic RO reverse osmosis membranes are only purchased from overseas. The service life of RO membranes with rolled membranes is generally 2-3 years. In the north, the TDS value is relatively high, affecting the service life. And the cost of RO membrane is high, and user replacement costs are high and troublesome. Shenzhen Hongjie Water will analyze the RO cleaning plan for you:

Introduction to Cleaning: The pre-treatment process design of the reverse osmosis system of a pure water machine has greatly removed the pollutants brought by the raw water, but not all of them can be removed, so the pollution phenomenon of the reverse osmosis system is very common. Fortunately, most pollutants can be removed through regular chemical cleaning. As long as the pretreatment work is normal and there are no uncontrollable reasons, such as changes in raw water quality or unavoidable microbial contamination, the cleaning frequency can be as low as possible. Sometimes operational errors can cause membrane fouling, such as high recovery rates or abnormal dosing systems. If the membrane is contaminated, the water yield will decrease, the desalination rate will decrease, and the pressure difference between the inlet and the concentrated water will increase. Membrane cleaning can increase the temperature of membrane cleaning solution by 45 ℃ for some acid-base agents (under pH2-pH12 conditions). Many pollutants, especially sticky mud, accumulate over time and are compressed and thickened, which increases the difficulty of cleaning and greatly prolongs the cleaning time. If the symptoms meet the following characteristics, immediately clean the membrane components: the standardized water production decreases by 10-15%, the desalination rate decreases by 0.5%, and the pressure difference △ P increases by 15% (compared to the initial pressure difference of 24-48 hours)

Prescriptions and other equipment need to be cleaned

1. Cleaning kit: Chemical cleaning kits are usually made of PE or FRP material and can withstand a pH range of 1-12.

2. Cleaning and heating device: The cleaning temperature should be as high as possible, such as 20-40 ℃. Chemical cleaning should not be carried out below 10 ℃, as the cleaning efficiency is very low, and therefore a heating device is also required for cleaning.

3. Cleaning agent: strong acids and bases are selected for cleaning (such as phosphoric acid, citric acid, sodium hydroxide, etc.), so it is very important to select chemicals. Sometimes, improper selection of agents may cause membrane pollution or even damage.

4. Cleaning pump: The pump is acid and alkaline resistant, with a flow rate of 12-15m3/h and a lift of 20-30 meters.

5. Corresponding pipelines, valves, and pressure gauges must be installed during cleaning. Connect the outlet of the pump to the inlet of the membrane, connect the concentrated water pipe to the medicine box, and install a ball valve before connecting it to the raw water tank to connect the medicine box and pump.

Cleaning program

1. The cleaning procedure is a cyclic cleaning, where the concentrated water outlet pipe is connected to the cleaning kit.

2. Inject pure water machine into the cleaning water tank to produce pure water, and the cleaning solution should meet the volume requirements of the pressure vessel and pipeline. Add 1% -2% of the reagent amount to the cleaning water tank, with an acidic pH value greater than 1 and an alkaline pH value not higher than 13.

3. Heating the cleaning solution to improve cleaning efficiency during better cleaning.

4. Inject the heated solution into the RO membrane of the pure water machine through a pump, with a flow rate of 10-15m3/h and a lift of 20-30 meters, which should meet the requirements and not be too high. When cleaning, do not circulate a bucket of liquid medicine into the medicine box. It should be discharged directly as it contains a large amount of pollutants, which can directly affect the effectiveness of the medicine and lead to poor cleaning. When there is no significant pollution afterwards, the liquid medicine will directly return to the original medicine box for cyclic cleaning. When cleaning, it is necessary to fully open the concentrated water discharge valve to reduce the pressure as much as possible, and close the production water valve to prevent the liquid from flowing into the pure water tank.

5. The general cleaning procedure is to cycle for 1-2 hours and soak for half an hour. Sometimes soaking for 1 hour or more can be very effective. Recirculation cleaning for 1-2 hours. It takes more than 4 hours to complete this cleaning program.

6. After cleaning, use a pure water machine for reverse osmosis to produce water or clean water (filtered and SDI ＜ 3, and free of residual chlorine and microorganisms, with a conductivity value of ＜ 10000) μ S/cm, rinse the membrane for at least half an hour.

7. After cleaning, the household water purifier system restarts, but the initial water may need to be discharged until the conductivity and pH value of the produced water are normal. Note that if the machine stops for more than 24 hours after cleaning, soak it in protective solution (1% sodium hydrogen solution). 

8. When the system is running again, scale inhibitor must be added to it, as the conductivity of the pre-treatment before the system is very high, exceeding 1000 μ S/cm, this water quality can easily cause membrane fouling, leading to an increase in conductivity, a decrease in water production, and a high pressure rise.

The above is the "RO reverse osmosis membrane cleaning plan" that Hongjie Water brings to everyone. We hope it can help you!