How to properly use a new RO reverse osmosis membrane?

First, the technical points of using the new RO reverse osmosis membrane:
1, first of all, the quartz sand, coconut shell activated carbon rinse clean, the new installation of quartz sand, coconut shell activated carbon time rinse longer.
2, test whether there is residual chlorine, such as residual chlorine exceeds the standard, to solve the problem of residual chlorine and then carry out the next step of RO reverse osmosis membrane.
3, the new membrane installed after the water, soak the membrane 1 to 2 hours, because it is a dry membrane, soak the membrane is more moist, to prevent the pressure is too high to damage the membrane.
4, and then start the high-pressure pump, the pressure should be increased slowly, from 2 kg slowly increased to 8 ~ 10 kg, the desalination rate of the new membrane better.
5、Control the residual chlorine below 0.003.
6, start the high-pressure pump before opening the thick water valve, such as the high-pressure pump is turned on slowly adjust the thick water valve, control the single membrane recovery rate of about 15%.
7, the first half an hour of produced water must be drained, because the membrane inside the protective fluid, so as not to affect the taste of the water.
8, test the incoming water PH value, 6.5 or more.

Second, how to determine the reverse osmosis membrane needs to be cleaned?

Reverse osmosis membrane elements in general, can be used for about 2 ~ 3 years. If you want to extend the service life, reverse osmosis membrane elements can be cleaned, usually divided into physical flushing and chemical flushing in two ways, when the physical flushing has not been able to make the performance of reverse osmosis membrane recovery, you should need to carry out chemical cleaning. Reverse osmosis membrane element in general, can be used for about 2~3 years. If you want to extend the service life, reverse osmosis membrane elements can be cleaned, usually divided into physical flushing and chemical flushing in two ways, when the physical flushing has not been able to make the performance of reverse osmosis membrane recovery, it should be required to carry out chemical cleaning.

Reverse osmosis membrane cleaning
According to experience, if the reverse osmosis device every three months or longer cleaning. If it is cleaned once every 1-3 months, it is necessary to improve the operating conditions to improve the pretreatment effect.

1 Judgment of cleaning
(1) The standardized fresh water yield has decreased by more than 10%.
(2) The standardized salt permeability has increased by more than 10%.
(3) The differential pressure between feed water and concentrated water has increased by more than 10% after temperature calibration in order to maintain a normal fresh water flow rate. (4) The internal unit had serious contaminants and scaling materials.
(5) Before the RO unit was shut down for an extended period of time.
(6) Routine maintenance of the RO unit.

Judge whether the reverse osmosis system before the implementation of cleaning, should also be considered comprehensively some of the following may produce the above phenomenon of other reasons:

☆ operating pressure drop (pressure control device failure and high pressure pump abnormalities);
☆ Decrease in water temperature (heater failure, or seasonal changes in water temperature);
☆ Increase in the salt content of the feed water;
☆ Abnormal pretreatment;
☆ Concentrated water seeping into fresh water due to membrane damage, misalignment of the center tube of the tandem membrane element, or poor sealing of the O-ring of the pressure vessel.

2 Pollutants
Common pollutants in the reverse osmosis membrane element are mainly CaCO3, CaSO4, BaSO4, SrSO4, metal oxides, silicon deposits, organic matter and biological slime. When the scale inhibitor dosing system or acid addition system fails, CaCO3 may be deposited in the membrane element, and chemical cleaning methods should be taken to cycle cleaning or overnight immersion.


3 Formulation
Different pollutants cause different degrees of damage to the membrane, different pollutants apply different cleaning solutions.

4Cleaning equipment

(1) reverse osmosis cleaning system
Generally consists of cleaning pumps, pharmaceutical preparation box, 5-20um security filters, heaters, related piping valves and control instruments.
(2) operation Cleaning methods include static immersion and cyclic cleaning. Static immersion with a cleaning solution to soak the membrane, depending on the degree of contamination, roughly 1-15 h. The general steps of the cycle of cleaning is:
1. Pump fresh water from the chemical preparation tank into the pressure vessel and discharge it for a few minutes.
2. Prepare a cleaning solution with fresh water in the chemical preparation tank.
3, with the cleaning solution on the pressure vessel cycle cleaning 1h or up to a predetermined time. The cleaning flow rate can be determined according to the following table, and when the contamination is serious, the cleaning flow rate can be increased to 150% of the resin in the table. At this time, the cleaning pressure drop is large, generally control does not exceed (0.10-0.14MPa)/root membrane element or 0.4MPa/root membrane module. Just started into the drug cleaning, available in the table 50% of the flow value of the heated cleaning fluid into the pressure vessel, control pressure, in order to be able to overcome the pressure drop between the water inlet and outlet water and no fresh water outflow is appropriate. In order to avoid the cleaning solution is diluted, you can open the thick water discharge valve, first discharge the system water before cleaning. Reverse osmosis system can be divided into sections for cleaning. Cleaning direction is the same as the direction of operation, do not allow reverse cleaning, otherwise it may cause the membrane roll protrusion and damage to the membrane element.
4、After the cycle cleaning is completed, use fresh water to wash the pharmaceutical preparation box again.
5、Flush the above pressure vessel with fresh water.
6、After flushing, run the reverse osmosis system with the fresh water discharge valve open until the fresh water is clean, no foam or no cleaning fluid, which usually takes 15-30mins.

Replacement of Reverse Osmosis Membrane

After a period of normal operation of the reverse osmosis equipment, the reverse osmosis membrane element will be contaminated by suspended or insoluble salts that may be present in the feed water, and the following symptoms will occur:

1, the weight of the membrane element of the reverse osmosis equipment increases;
2, RO membrane removal rate increases or decreases significantly;
3, the standard pressure, reverse osmosis equipment water production decreased significantly;
4, in order to achieve the standard water production, need to improve the operating pressure;
5, reverse osmosis equipment, the pressure drop between the feed water and concentrated water increased;
6, remove the membrane element from the pressure vessel, pour water on the inlet side of the vertical membrane element, if the water can not flow through the membrane element, only overflow from the end surface, indicating that the inlet runner is blocked.

Whether it is necessary to replace the reverse osmosis membrane element, or according to the actual situation.