Author: Site Editor Publish Time: 2022-05-31 Origin: Site
When the raw water is not flowing into the reverse osmosis membrane system, all remaining abnormal substances in the pre-treatment equipment that may accompany the flow of water should first be thoroughly removed before commissioning the equipment.
1. Check that all valves in the equipment (system) are in the correct condition, in particular to confirm that the raw water pressure adjustment and thick water adjustment valves are fully open. In large reverse osmosis systems, the electric slow-opening valves in the equipment should be checked first to see if they can be opened and closed automatically according to the program.
2. When the system has a raw water supply pump for the reverse osmosis system, it should first exhaust and flush the reverse osmosis equipment at low pressure and low flow rate. If the system does not have a separate feed pump, the raw water supplied by the system can be used to flush the membrane with chemicals and air at low pressure, with the flushing time controlled between 10-30 minutes. The operating pressure of the system is best controlled at around 30-60psi and the flow control should ideally meet the recommended operating flow rate for chemical cleaning. At this time the output water and concentrated water should be drained, and the concentrated water regulating valve of the concentrated water system and the discharge valve connected to the concentrated water outlet should be in a fully open state. During this process, attention should be paid to checking the equipment piping connection status and valves for water leakage.
3. For small reverse osmosis systems that do not use an electric slow-opening inlet valve, the high pressure pump should be started with the raw water pressure regulator valve into the pressure vessel section slightly open. For large reverse osmosis units the raw water inlet electric slow opening valve should be automatically programmed to start at the same time as the reverse osmosis high pressure pump.
4. After the reverse osmosis high-pressure pump is started, then slowly open the raw water pressure regulating valve (i.e. the electric slow opening valve set for large equipment) so that the raw water pressure rises slowly, the control speed of the pressure increase of the reverse osmosis system (or the control of the opening speed of the electric slow opening valve) should be controlled within the incremental range of 4.0~6.0kgf/cm2 per minute, and make the product water flow basically reach the designed value, then slowly adjust the concentrated water Control valve, so that the system water recovery rate to reach the design value. This adjustment is repeated until the product water flow and the system recovery rate reaches the designed value. It should be noted that during the adjustment process the water recovery rate and operating pressure of the reverse osmosis system and the pressure drop of the membrane element should not exceed the design limit.
5. At the end of the initial adjustment of the system, the system should be re-calculated and compared with the design value of the system, if it is lower than the design value, then find out the reason.
6. Re-confirm whether the injection quantity of various drugs in the reverse osmosis system is appropriate.
7. Determine the conductivity, inlet pH, hardness and alkalinity of the raw water, each section of produced water and the total output water, and calculate the flow rate of the reverse osmosis concentrated water system under the operating conditions, so as to determine whether there is dirt formation in the reverse osmosis system under the given system water recovery rate.
8. Start recording all operating data after approximately 1 to 2 hours of operation and reconfirm if there are any other problems with the system.