Detailed chemical cleaning of reverse osmosis system
Chemical cleaning of osmotic equipment is mainly to use scale inhibitor to prevent scaling, and cleaning agent is used to carry out chemical cleaning after scaling.
A reverse osmosis membrane is designed in the reverse osmosis purification equipment. The pressure on both sides of the membrane is different. The pressure on both sides is the driving force to press the raw water through the reverse osmosis membrane. The low salt concentration will permeate to the high salt concentration direction. The reverse osmosis process occurs when the pressure on one side of the containing brine is opposite to the osmotic pressure on the other.
Reverse osmosis technology has been widely used because of its special advantages. The cleaning problem of reverse osmosis water purification equipment may cause many users with weak technical strength to suffer losses, so it is necessary to do a good job in the management of reverse osmosis equipment to avoid serious problems.
Reverse osmosis equipment for low pressure flushing
Regular flushing of the reverse osmosis equipment with large flow, low pressure and low pH value is conducive to stripping the dirt attached to the membrane surface and maintaining the membrane performance. Or when the inlet water SDI of the reverse osmosis equipment suddenly rises over 5.5, low pressure flushing should be carried out and the machine should be started up after the SDI value is adjusted to qualified.
Reverse osmosis equipment outage protection
Due to the fluctuation of production, the reverse osmosis equipment will inevitably be out of service frequently. Protective measures must be taken when the equipment is out of service for a short or long time. Improper treatment will lead to the deterioration of membrane performance and non-recovery.
Short-term storage is suitable for systems with outage of less than 15d. The reverse osmosis equipment can be protected by low-pressure flushing every 1 to 3 days. Practice has found that when the water temperature is above 20℃, the water in the reverse osmosis equipment will stink and deteriorate for 3 days, and a large number of bacteria will multiply. Therefore, it is recommended that when the water temperature is higher than 20℃, low-pressure flushing should be done every 2D or 1D; when the water temperature is lower than 20℃, low-pressure flushing should be done every 3D. After each flushing, all inlet and outlet valves on the reverse osmosis device of the water purification equipment should be closed.
Long-term outage protection is applicable to the outage of more than 15d system, when the protection solution (fungicide) must be filled into the water purification equipment reverse osmosis device for protection. Commonly used fungicide formula (composite membrane) is formaldehyde 10 (mass fraction), isothiazolinone 20mgL, sodium bisulfite 1 (mass fraction).
Chemical cleaning of reverse osmosis membrane
Under the condition of normal operation, reverse osmosis membrane may also be inorganic scale, colloid, microorganism, metal oxides, such as pollution, these substances deposited on the membrane surface to cause water purification equipment, reverse osmosis device output descent or desalination rate, differential pressure increases, even cause unrecoverable damage to membrane, therefore, in order to restore good waterproof and desalination performance, need for chemical cleaning membrane.
Generally, cleaning is done once every 3 to 12 months. If cleaning has to be done once every month, it indicates that the pretreatment system should be improved and the operating parameters adjusted. If cleaning is needed once every 1 to 3 months, the operating level of the equipment needs to be improved, and it is difficult to judge whether the pretreatment system needs to be improved.
