Storage of membrane elements
Store the components in a cool, dry warehouse, or package them for storage. The minimum temperature should be higher than 5°C, and it is best to keep it at 10-20°C.
Preservation of membrane systems
1.Short-term storage
No flushing is required within 2 hours of shutdown; If the machine is shut down for more than 2 hours, perform RO product water flushing for 20 minutes;
2. Medium-term storage If the machine is shut down for 3 days or more and within 30 days, follow the steps below to save: (1) Cleaning-in-line (CIP) RO Membrane Element; (2) Use RO produced water to rinse for more than 30 minutes; (3) When the flushing is completed, keep the membrane in the flushing water (RO product water) and close the valve to keep the solution in the RO section; (4) Perform steps 2 and 3 once a week. (5) This method needs to ensure that the flushing water source is always clean, and be careful to prevent the growth of microorganisms in the pipelines and water tanks to avoid secondary pollution of the membrane elements.
Long-term storage
If the machine is shut down for more than 30 days, use bisulfite to preserve the Ro Membrane and follow the following steps: (1) Cleaning-in-line (CIP) RO Membrane Element; (2) Use RO produced water to rinse for more than 30 minutes; (3) Use 1.0% sodium bisulfite solution configured in RO produced water to flush the RO section; (4) When the RO section is filled with the solution (it is required to ensure that it is completely filled), close the valve to retain the solution in the RO section; (5) When the temperature is lower than 27°C, repeat steps 1, 2, and 3 with fresh cleaning solution every 30 days. When the temperature is higher than 27°C, repeat steps 1, 2, and 3 with fresh cleaning solution every 15 days; 6) The pH value of the solution should be controlled between 3.5-9.5 and should be tested regularly. If the pH value is not within the above range, the protective solution should be replaced, as long-term exposure to acidic or alkaline environments will cause damage to the membrane. Regularly monitor the concentration of acid sulfite. If the solution concentration is lower than 0.1%, a new solution should be used, and the temperature should be kept below 25°C; (7) When the ambient temperature is likely to be lower than 5°C, the system must be filled with antifreeze, and the pipelines must be protected against frost cracking. Usually 30% glycerin or 20% ethylene glycol (freezing point is about -10°C) can be used as antifreeze. The operation steps are the same as the long-term preservation method of the membrane above. The membrane is first chemically cleaned and rinsed with pure water, and then replaced with antifreeze and sealed; (8) When the Ro System is ready to be restarted, open the water outlet valve, flush the system with low-pressure water until it is flushed, and discharge the produced water. Before resuming operation of the RO system, it is necessary to check the residual disinfectant in the produced water.
