How to maintain reverse osmosis water treatment equipment in winter and precautions
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Update time : 2023-03-15 17:57:22
Winter reverse osmosis water treatment equipment how to maintain and precautions
If conditions permit, when the water temperature drops below 15℃, the raw water heating device should be added in time. Ensure that the inlet water temperature of the reverse osmosis system is between 18-30℃, and the optimal temperature is 22.5℃.
Unconditional site, when the water temperature drops below 15℃, strengthen the backwashing frequency and strength of reverse osmosis water treatment equipment pretreatment device, ensure that the filter element should be replaced in time, reverse osmosis system water quality qualified.
Note: The continuous operating environment of reverse osmosis device shall not be lower than 0℃.
For the devices installed outdoors or indoors without heating and insulation facilities, if conditions permit, the equipment can be temporarily shut down, all the water in the equipment and pipes can be emptied, and the membrane elements can be removed from the equipment and stored.
If it must be run, it is necessary to add anti-freezing and insulation measures on the equipment and pipelines. Generally, electric tracing belts are wrapped around the equipment and pipelines, and then heat preservation, and electric heating boxes are placed around the equipment.
Winter operation and maintenance of reverse osmosis water treatment equipment
Short - term protection measures for reverse osmosis water treatment equipment
There are two short-term protection measures for the reverse osmosis water treatment equipment. The premise is that the ambient temperature of the reverse osmosis system is higher than 0 ° C. The short-term protection measures are applicable to the reverse osmosis system that is out of service for more than 2 days but less than 30 days.
Note: If contamination of the RO system is known or suspected, the system must be effectively chemically cleaned (non-oxidizing sterilization, alkaline, acidic and finally alkaline cleaning) before being discontinued or protected. The following protective measures must be implemented within 10 hours after cleaning.
The specific steps are as follows:
The first: short - term winter shutdown maintenance of reverse osmosis water treatment equipment
①Wash the reverse osmosis system with reverse osmosis product water, while paying attention to the complete elimination of gas from the system;
② After the pressure vessel and related pipelines are filled with water, close the relevant valves to prevent gas from entering the system;
③ Rinse the reverse osmosis system every 5 days according to the above method.
The second: short - term winter shutdown maintenance of reverse osmosis water treatment equipment
Rinse the water supply pump of the RO system for 15-30 minutes every day at a low pressure (0.2-0.3Mpa, as far as possible to ensure that no obvious permeable water will be produced on the water-producing side), during which no pretreatment agent shall be added. The washing water temperature is recommended to be 20-25℃ or run every 48 hours at a low recovery rate (about 50% of the rated recovery rate) for 2-4 hours.
Note: The above two short-term protection measures, if the site conditions, it is recommended to use the second short-term protection measures.
Discontinue use of reverse osmosis systems for more than 30 days.
For known membrane contamination or suspected membrane element contamination of the system must be first carried out effective chemical cleaning (first non-oxidation sterilization, then alkaline, acid and finally alkaline cleaning). Within 10 hours after cleaning, protective measures must be implemented as soon as possible to reduce maintenance during outage.
The specific steps are as follows:
①Fill the cleaning tank with RO water or debrine.
② Add 1wt% sodium bisulfite and 20wt% glycerin into the cleaning tank and mix.
③ Recycle the solution in the RO system for 20-30 minutes by cleaning the water pump to drive away the air from the pressure vessel. It is recommended to use the overflow mode and recycle the protection solution to make the residual air in the RO system as little as possible.
④ Close all valves in the RO system to prevent air contact with the protective liquid, so that the protective liquid is retained in the system.
⑤ If the ambient temperature is lower than 20℃, replace the protective liquid every 30 days; If the ambient temperature is higher than 20 ° C, replace the protective solution every 15 days and check the pH value of the protective solution once a week. When the pH value is lower than 3, replace the protective solution in time.
⑥ During the outage, it is necessary to prevent the icing of the membrane system, and the lowest temperature cannot be lower than 0℃. When the above conditions are met, the lower the storage environment temperature is, the better, so as to ensure that the membrane components are stored in the membrane shell for one year and the film performance is basically not affected, but it is still recommended that the long-term outage time of the RO system be controlled within one year.
⑦ Before the reverse osmosis system is put back into use, use low pressure feed water flushing system for at least 1 hour, and then use high pressure feed water flushing system for 15 minutes. No matter low pressure flushing or high pressure flushing, the water discharge valve of the system should be fully opened. Before restoring the normal operation of the system, check and confirm that the residual chlorine of reverse osmosis inlet water is less than 0.1ppm. If the water production decreases significantly after operation, chemical cycle cleaning with 0.1% NaOH solution should be carried out in time.
⑧ For long-term storage RO system, also can be used to disassemble the membrane element preservation, specific operation methods see industrial reverse osmosis membrane element storage protection introduction.
Matters to be considered when reverse osmosis water treatment equipment is shut down for maintenance and preservation in winter
(1) After shutdown, use treated reverse osmosis supply water, softening water or product water to wash the system;
(2) In order to maintain the performance of the system, the membrane element must always be kept moist;
(3) In order to prevent the growth of bacteria in the pressure vessel, disinfection should be carried out;
(4) If the membrane element is contaminated, there may be a system failure, so before storage to chemical cleaning, so that the dirt can be removed from the membrane element, the growth of bacteria is limited to a small possibility;
(5) The allowable temperature and pH value range when stored in the pressure vessel are as follows: Temperature range: 0~35℃, pH range: 3-7.
(6) Acidic sodium bisulfite (SBS) solution was used for preservation. The water in which the preservation solution is prepared must be free of residual free chlorine or other oxidants.
The use of reverse osmosis water treatment equipment daily outage
0-48 hours of shutdown of reverse osmosis water treatment equipment: refer to the normal shutdown procedure. In order to prevent the breeding of microorganisms, low-pressure flushing is conducted every 24 hours
Reverse osmosis water treatment equipment short - term outage 2-25 days
①After shutdown, ensure that the pressure vessel is filled with R0 pure water, and close all inlet, concentrate, and water producing valves to prevent membrane components from drying out and microorganism breeding.
②When the temperature is above 20℃, repeat washing should be done every 12 hours. When the temperature is less than 20℃, repeat washing every 24 hours;
③Surface water or water sources with high microbial contamination should be rinsed with R0 solution containing 1.0% sodium bisulfite. If membrane elements are soaked with this solution at the same time, the effect will be better and the repeat washing cycle will be extended accordingly.
④During the shutdown of the system, keep the temperature between 5℃ and 45℃. Low temperature is good for preserving membrane components, but should prevent the system from freezing.
· Long-term outage without insulation conditions
Reverse osmosis water treatment equipment for more than 25 days
①Proceed according to the normal shutdown procedure. Rinse the system with product water at low pressure. At the same time, chemical cleaning and sterilization are carried out.
②Using reverse osmosis purified water, a protective liquid containing 1.0 percent sodium bisulfite was used to flush the membrane components using a chemical cleaning system to expel air from the pressure vessel. The membrane components were completely immersed in the protective liquid to prevent them from drying out. All water inlet, concentration and production valves were closed to prevent air from entering and making the protective liquid ineffective.
③Checking the pH value of protective fluids once a week. If the pH value is less than 3, replace the protective fluids promptly.
④During system shutdown, keep the temperature between 5°C and 45°C. Low temperature is good for preserving membrane components but should prevent the system from freezing.
The use of reverse osmosis water treatment equipment daily outage
Dry film components must be stored in a cold, dry place without direct sunlight, and the ambient temperature should be lower than 45 ° C.
If it is a wet membrane element, it needs to pay attention to the storage environment temperature should be greater than 5℃, below 45℃.
If the membrane element has been transported or stored below 0℃, in the presence of icing conditions, the diaphragm should not be put into operation immediately in order to prevent scratches. Should be at room temperature slowly "melt ice", to be completely ice-free before pressure operation
The membrane element must always be kept in a wet state after water flow. Even if it needs to be opened temporarily in order to confirm the quantity of the same package, it must be done in a state that does not damage the plastic bag, and this state should be kept until the time of use;
Membrane element is better stored in 5~10℃ low temperature. When storing in an environment where the temperature exceeds 10℃, choose a well-ventilated place and avoid direct sunlight. The storage temperature should not exceed 35℃.
If the membrane element freezes, physical damage will occur, so insulation measures should be taken, do not make it freeze;
When stacking membrane components, do not pack more than 5 layers of boxes and ensure that the boxes are kept dry.
Other precautions for reverse osmosis water treatment equipment
1. When the water inlet pipe breaks or stops water
When the temperature is too low in winter, the water inlet pipe of the reverse osmosis water treatment equipment is also easy to break. When the water inlet pipe breaks or the water supply stops, try not to use the equipment. You can close the inlet ball valve and open the tap after the water is brought in, so that the reverse osmosis equipment can work 2, when the indoor temperature is low
In the indoor reverse osmosis water treatment equipment, the room temperature in the equipment operation workshop shall not be less than 0 degrees, and the equipment and pipes installed in the outdoor shall have anti-freezing measures. When the temperature drops below zero degrees, the anti-freezing work of the equipment must be done. 3. When water production drops
Because the winter temperature is too low, water treatment equipment will appear the phenomenon of water production decline, strengthen the pretreatment device backwash times, washing time increase, fine filter element frequently change, reduce pressure, can make reverse osmosis water treatment equipment can operate normally. 4. When the equipment is not in use or out of service for a long time
In winter, if the equipment is not used for a long time or the equipment is out of service, it is necessary to close the inlet ball valve, discharge the water in the pressure bucket, check whether the appearance of the machine is normal before use again, and start again after confirmation.
