Under what circumstances does reverse osmosis need to be flushed?

Initial startup: Low-pressure flushing with pre-treated raw water is required, mainly to remove the air in the pressure vessel. The membrane element should be flushed for at least 6 hours when it is a dry membrane, and at least 30 minutes when it is a wet membrane.

Shutdown flushing: When the Reverse Osmosis is shut down, it must be flushed with produced water to replace the concentrated brine in the membrane system until the conductivity of the concentrated water outlet is close to the conductivity of the inlet water.

Shutdown flushing: When the reverse osmosis is shut down for more than 48 hours, it can be flushed once every 24 hours at most. If this cannot be done, it needs to be sealed.

Preventive flushing: In the wastewater reuse system, when the organic matter in the influent is relatively high, the program control is set to flush once every 12 hours to reduce the fouling rate.

Single-stage preventive flushing: For systems with a high recovery rate such as 85%, three stages are usually set (except for secondary RO), and the risk of fouling in the third stage is extremely high. The design considers that the third section can be isolated and flushed separately. The third section is isolated and flushed once every 12 hours without affecting the water production of sections 1 and 2.

Post-cleaning flushing: After chemical cleaning, flush with pre-treated qualified raw water to remove the cleaning liquid in the system. The flushing time is about 1 hour.