In the state that the raw water does not flow into the reverse osmosis membrane system, it should firstly completely remove all the abnormal substances that still exist in the pretreatment equipment and may flow out along with the feed water before carrying out the trial operation of the equipment.

1、Check whether all the valves in the equipment (system) are in the correct state, especially confirm whether the raw water pressure adjustment and thick water adjustment valve is completely open. In the large reverse osmosis system, you should first check whether the electric slow-opening valve configured in the equipment can automatically open and close according to the program.

2, when the system has raw water supply pump for reverse osmosis system water supply, should be the first low pressure, low flow rate of reverse osmosis equipment for exhaust and flushing. If the system does not have a separate water supply pump, then the raw water supplied by the system can be used to flush the membrane with low-pressure material containing chemicals and air, and the flushing time is controlled to be between 10 and 30 minutes. This operation of the system's operating pressure is best controlled at about 30 to 60 psi, flow control should be able to achieve the best chemical cleaning of the recommended operating flow value. At this time the output water and concentrated water should be drained off, the concentrated water system of the concentrated water regulating valve and the discharge valve connected to the concentrated water outlet should be in a fully open state. In this process, attention should be paid to check the equipment piping connection status and the valve for leakage.

3, for the small reverse osmosis system without the use of water inlet electric slow opening valve, should enter the pressure vessel part of the raw water pressure regulator valve slightly open state to start the high-pressure pump. And large reverse osmosis device of raw water inlet electric slow opening valve should be in reverse osmosis high pressure pump start at the same time automatically according to the program start.

4, reverse osmosis high-pressure pump start, and then slowly open the raw water pressure regulating valve (i.e., large-scale equipment set the electric slow-opening valve) so that the raw water pressure rises slowly, reverse osmosis system pressure increase control speed (or electric slow-opening valve opening speed control) should be controlled in the incremental range of 4.0 to 6.0kgf/cm2 per minute, and make the product water flow rate basically reaches the value of the design, and then slowly Adjust the thick water adjustment 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 design value. It should be noted that in the adjustment process can not make the reverse osmosis system water recovery rate and operating pressure and membrane element pressure drop exceeds the design limit value.

5, in the system after the end of the initial adjustment, should recalculate the system running water recovery rate and compare with the design value of the system, if it is lower than the design value, then find out why.

6, reconfirm the reverse osmosis system in a variety of drugs injected into the right amount.

7, the determination of raw water, water production and total water conductivity, water pH, hardness, alkalinity, etc., calculate the operating conditions of the reverse osmosis concentrated water system flow value, so as to determine the given system water recovery rate of reverse osmosis system with or without the formation of fouling.

8, running about 1 ~ 2 hours after the start of recording all the operating data, and again to confirm whether the system has other problems.

Reverse osmosis system shutdown stop notes

Typical system shutdown sequence is:

1, slowly close the influent control valve; slowly open the thick water control valve to maintain the design thick water flow;

2, stop the high-pressure pump when the high-pressure pump discharge flow drops to the lowest flow rate;

3, adjust the pretreatment dosing device status;

4, with pretreatment qualified feed water or produced water products (preferably with produced water products) on the system for low-pressure flushing, to ensure that the concentrated brine completely removed from the pressure vessel (at this time, the concentrated water conductivity = rinse water conductivity);

5、When the flushing is completed, close the concentrated water valve and water production valve;

6, shut down the water side of the back pressure must not exceed 0.07Mpa. reverse osmosis system should be completely filled with water, it is recommended that in the concentrated water and produced water pipeline to install check valves, check valves are higher than the highest pressure vessel, automatic exhaust valve is installed above the check valve, which will eliminate the siphon phenomenon.

7、Ensure that the membrane element has been kept wet and has been properly sterilized and protected from freezing throughout the shutdown period;

8. Ensure that the temperature and pH value of the preservation fluid are fully in compliance with the specifications during the shutdown period.