Summary of reasons for damage to the EDI in ultra-pure water equipment
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1. When the EDI membrane module operates for extended periods under high current levels with a flow rate below the rated value, the heat generated on the plate side cannot be dissipated effectively. As a result, the membranes and separators near the poles of the EDI unit become heated and deformed first. This leads to an increase in the pressure difference in the concentrated water stream, a decline in water quality and quantity, and in severe cases, carbonization and leakage may occur. 2. If the EDI membrane module is not cleaned and maintained for an extended period, scaling occurs on the membranes and channels of the EDI system, the pressure difference between the inlet and outlet water increases, which leads to a decline in the quality of the produced water. The current cannot be adjusted, and the voltage rises. 3. Improper control of oxidants such as residual chlorine in the ultrafiltration system results in an excess of oxidants reaching the EDI unit, causing the EDI resin to break down and blocking the water output channels, thereby reducing the water flow rate. 4. Improper cleaning and disinfection directly cause the EDI resin to break down, increasing the pressure difference between the inlet and outlet water, which results in a decline in both the quality and quantity of the produced water. 5. When the EDI system is operated manually and powered on in a condition of water shortage, it causes the membrane and resin to heat up and carbonize; cleaning is ineffective and the system becomes unusable. 6. There is no safety filter before the water enters the EDI system, or the pipes and tanks were not thoroughly cleaned during installation; as a result, foreign objects block the EDI channels, increasing the pressure difference between the inlet and outlet waters, which leads to a significant reduction in the amount of water produced, and cleaning efforts prove ineffective. 7. The product was defective at the time of manufacture, and it started leaking for no apparent reason after being used for some time. 8. The current and voltage exceed the rated values, or there is human error in operation. 9. The system’s process design is inadequate, failing to meet the requirements for using EDI. 10. Improper system maintenance and management, with failure to comply with the usage conditions of EDI.
I recently came into contact with EDI and there are some things I don’t quite understand. Please give me some guidance. I saw some information stating that EDI exports also involve the discharge of extreme water; I checked ours but didn’t find any such discharge, and I’m not clear about the principle behind extreme water discharge I think I still don’t fully understand the overall principle of EDI. From the information I’ve read, there are a concentrated water chamber and a fresh water chamber, as well as anion and cation resins and electrodes. Is the EDI feed water in the advanced concentration chamber or in the fresh water chamber? The concentrated chamber releases weak acids such as CO2 and SiO2, while the fresh water chamber removes ions like Ca2+ and Mg2+ Does the EDI effluent come from fresh water? Is there some concentrated water circulation in the concentrated chamber? Overall, the information available isn’t complete, so my understanding is rather vague or incorrect. I would appreciate it if the original poster could give some guidance. Water supply here has been inadequate recently; it seems that the system hasn’t been properly maintained or cleaned for some time. I hope to be able to contact you on QQ at your convenience to ask for your advice. My QQ number is 1817581817