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RO reverse osmosis membrane |
| Publisher: Suzhou Huanke Pharmaceutical Equipment Technology Co., Ltd Time：2023-03-07 15:41:16 Number of clicks：290 Close |
| Why can the service life of RO reverse osmosis membrane of purified water equipment be shortened? RO reverse osmosis membrane aperture is as small as nanometer (1 nanometer =10*-9 meters), under a certain pressure, water molecules can pass through the RO membrane, and the inorganic salts, heavy metal ions, organic matter, colloids, bacteria, viruses and other impurities in the source water can not pass through the RO membrane, so that the pure water can be permeable and the concentrated water can not be strictly separated. RO reverse osmosis membrane civil aspect is used for pure water machine at most, as one of the filtration devices of pure water machine purification, plays the core role in the filtration of tap water to clean water. RO membrane can effectively remove calcium, magnesium, bacteria, organic matter, inorganic matter, metal ions and radioactive substances in the water, and the water purified by the device is crystal clear, sweet glycol. The device is suitable for drinking water purification at home, hotels, hospitals and other enterprises and institutions.
Reasons for shortening the service life of RO 1. Improper operation of reverse osmosis equipment causes damage to membrane performance Residual gas in reverse osmosis equipment operating under high pressure, forming a gas hammer will damage the reverse osmosis membrane. Two things often happen: A. After the equipment is emptied, when it is re-run, the gas is not exhausted and the pressure is increased rapidly. The remaining air should be drained out at a pressure of 2 ~ 4bar, and then gradually run with increased pressure. B. When the joint between the pretreatment equipment and the high pressure pump is not sealed well or leaked (especially when the microfilter and the pipeline leakage after it), when the pretreatment water supply is not enough, such as the blockage of the microfilter, the vacuum will suck some air into the place where the seal is not good. The microfilter should be cleaned or replaced to ensure that the pipeline does not leak. In a word, the pressure should be increased step by step in the flowmeter when there is no bubble in the operation, and the bubble should be gradually reduced to check the cause. 2. The method of shutting down reverse osmosis equipment is incorrect A. Rapid depressurization without thorough washing when shutting down. Because the concentration of inorganic salts on the membrane concentrated water side is higher than that of raw water, it is easy to scale and pollute the membrane. B. Rinse with pretreatment water with added chemical reagents. Water containing chemical reagents may cause membrane contamination during equipment outage. When the reverse osmosis equipment is ready to shut down, it should stop adding chemical reagents, gradually reduce the pressure to about 3bar, rinse with pre-treated water for 10min, until the TDS of the concentrated water is very close to that of the raw water. 3. Poor disinfection and maintenance of reverse osmosis equipment lead to microbial contamination This is a common problem in the use of composite polyamide membrane, because of the poor chlorine resistance of polyamide membrane, the correct addition of chlorine and other disinfectants in use, coupled with the user's insufficient attention to the prevention of microorganisms, easy to lead to microbial pollution. At present, the pure water produced by many manufacturers exceeds the standard of microorganisms, which is caused by poor disinfection and maintenance. The main performance is: when leaving the factory,RO equipment does not use disinfectant maintenance; Failure to disinfect the entire pipeline and pretreatment equipment after installation; Discontinuous operation without taking disinfection and maintenance measures; No regular disinfection of pretreatment equipment and reverse osmosis equipment; Maintenance solution failure or insufficient concentration. 4. Ineffective monitoring of residual chlorine in reverse osmosis equipment 1, such as adding the drug pump failure or liquid failure, or activated carbon saturated due to residual chlorine damage membrane. 2, cleaning and cleaning method is not correct resulting in damage to the film performance. In addition to the normal degradation of equipment performance during use, the degradation of equipment performance caused by pollution is more serious. The usual pollution mainly includes chemical scale, organic matter and colloid pollution, microbial pollution and so on. Different kinds of pollution show different symptoms. The symptoms of membrane contamination presented by different membrane companies are also different. In the project, we found that the duration of pollution is different, the symptoms are also different. Such as: calcium carbonate fouling film, pollution time for a week, the main performance is the rapid decline of desalting rate, pressure difference increases slowly, and the change of water production is not obvious, with citric acid cleaning can completely restore the performance. The pollution time was one year (a pure water machine), the salt flux increased from the initial 2mg/L to 37mg/L(raw water was 140mg/L ~ 160mg/L), and the water yield decreased from 230L/h to 50L/h. After cleaning with citric acid, the salt flux decreased to 7mg/L and the water yield increased to 210L/h. Moreover, pollution is often not a single, its symptoms also have a certain difference, making the identification of pollution more difficult. The identification of pollution types should be based on raw water quality, design parameters, pollution index, operation records, equipment performance changes and microbial indicators. (1) Colloidal pollution: When colloidal pollution occurs, it is usually accompanied by the following two characteristics: A. In the pre-treatment, the microfilter is plugged quickly, especially the pressure difference increases quickly. B, SDI value is usually above 2.5. (2) Microbial contamination: When microbial contamination occurs, the total number of bacteria in the permeating water and concentrated water of RO equipment is relatively high, so it must not be maintained and disinfected as required at ordinary times. (3) Calcium scale: can be judged according to the raw water quality and design parameters. For carbonate water, if the recovery rate is 75% and scale inhibitor is added during design, the LSI of the concentrated solution should be less than 1. When no scale inhibitor is added, the LSI of the concentrate should be less than zero, and calcium scale will not be produced in general. (4) 1/4 inch PVC plastic pipe can be inserted into the component to test the performance changes of different parts of the component to judge. (5) Determine the type of pollution according to the change of equipment performance. (6) Calcium scale can be determined by pickling (such as citric acid and dilute HNO3) according to the cleaning effect and cleaning solution, which can be further confirmed by the analysis of the composition of cleaning solution. (7) Chemical analysis of the cleaning solution: raw water, cleaning stock, cleaning liquid, three sample analysis. After determining the type of contamination, it can be cleaned according to the method in Table 1, and then disinfected for use. When the type of contamination cannot be determined, cleaning (3)+ disinfection +0.1%HCl(pH 3) is usually performed. |
Suzhou Huanke Pharmaceutical Equipment Technology Co., Ltd.
Suzhou Chenglang Cleaning Equipment Co., Ltd.
Contact: Zhang Gong
Tel：15150275957
Email：285145232@qq.com
Company website： http://www.szhuanke.com
Add：No. 366, Jinxian Road, Jinjiaba Town, Wujiang District, Suzhou City, Jiangsu Province
Su ICP No. 2022043966-1
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