Overview

Municipal water tank → raw water tank → original water pump → quartz sand filter → activated carbon filter → security filter → filter tank → a booster pump → a RO reverse osmosis → middle tank → secondary booster pump → secondary RO Infiltration → pure water tank → pure water pump → 0.45μ precision filter → TOC removal device → EDI device → polished mixed bed → 0.22μ precision filter → water point

EDI working principle

EDI is removed by exchanging residual salts of RO water with hydrogen ions or hydroxide ions and sending them to the concentrated water stream. The exchange reaction is carried out in the purification chamber of the membrane, where the anion exchange resin uses their hydroxide ions (OH-) to exchange the anions (such as chloride ion Cl-) in the dissolved salt. Correspondingly, the cation exchange resin uses their hydrogen ions (H +) to exchange the cations (such as Na +) in the dissolved salt. A direct current field is applied between the anode (+) and the cathode (-) located at both ends of the membrane block. The potential causes the ions exchanged on the resin to migrate along the surface of the resin particles and enter the concentrated water chamber through the membrane. The anodes attract negative ions (such as Cl-, OH-), which pass through the anion selective membrane into the adjacent concentrated water stream and are blocked by the cation selective membrane, leaving the concentrated water stream. The cathode attracts the cations in the concentrated water stream (eg Na +, H +). These ions pass through the cation selective membrane into the adjacent concentrated water stream and are blocked by the anion selective membrane, leaving the concentrated water stream. When water flows through these two parallel chambers, the ions are removed in the pure water chamber and gathered in the adjacent concentrated water stream, which is then removed from the membrane by the concentrated water stream.


The use of ion exchange resins in pure water and concentrated water is the key to EDI technology. An important phenomenon occurs in the ion exchange resin of a pure water chamber. In the local area where the potential difference is high, the electrochemical reaction decomposes the water to produce a large amount of H and OH. The production of local H and OH in the self-exchange resin of the mixed bed allows the resin and membrane to be continuously regenerated without the addition of chemicals.


Quality assurance and technical services

We have the spirit of the user responsible for the purpose of the implementation of quality assurance service. Since the equipment installation, commissioning, acceptance of delivery after delivery of a year, to give quality assurance, free service, that is caused by non-human factors, but because the product Quality caused by the system failure.

Provide a complete unit of equipment operation, maintenance instructions, free of water treatment operations management personnel for theoretical training and on-site training.