EDI is placed after RO system, which is the replacement of ion exchange resin and has the stable water quality, low run cost, convenient operation management, small covering area.
The essence of high pure water equipment
EDI uses anion and cation membrane, symmetrical stacking, anion and cation resins are between anion and cation membrane, by means of volts direct current, anion and cation exchange is done. Meanwhile, under the action of voltage gradient, the water will be electrolyzed into a large number of hydrion and hydroxide ion, these ions will have the regeneration to anion and cation continually. Due to the constant EDI exchange—regeneration, the purity of water will become higher and higher, then we can get the high pure water with high purity.
I. Working principle
1. When the water enters into EDI system, one part of water will flow into the internal resin/membrane, the other part flows by the external membrane, in order to wash away the ions in the outside of membrane.
2. Resin will intercept the dissolved ions.
3. The intercepted ions are under the action of electrodes, anion will move to the direction of anode, cation will move to the direction of cathode.
4. Cation permeates cation membrane, which is discharged to the external resin/membrane.
5. Anion permeates anion membrane, which is discharged to the external resin/membrane.
6. The concentrated ions will be discharged through the waste streams.
7. Deionized water will flow out by the internal resin/membrane.
I. Performance advantages of EDI high pure water equipment
1. Produce pure water with high quality continuously and stably, no need for stop on account of resin regeneration;
2. No wastes discharge, green and saving cost of investment;
3. The equipment structure is compact, which has many advantages, such as small covering area, saving-energy and so on.
4. The equipment will be debugged in the factory, field work is light, work training is simple.
5. It just needs daily maintenance, simple operation, low labor intense.