The EDI system is a new desalination process that combines electrodialysis and ion exchange technology. This process takes advantage of the strengths of electrodialysis and ion exchange to compensate for their weaknesses. It uses ion exchange energy to deeply desalinate to overcome electrodialysis polarization and incomplete desalination, and uses electrodialysis polarization to ionize water and produce hydrogen ions and ozone ions to achieve resin regeneration, overcoming the defect of resin regeneration through chemical agents after resin failure. This technology is used in the pharmaceutical and chemical industries for high-purity water, the electronics and power industries for ultrapure water, and other industries for ultrapure water.

Ultra pure water equipment typically consists of ultrafiltration devices, reverse osmosis devices, and ion exchange devices,Composed of EDI devices and other components to meet the water quality requirements of the electroplating industry.

The process of ultrapure water equipment can be roughly divided into the following categories

1. The process of using ion exchange is as follows:

Raw water→ Raw water booster pump → Multi medium filter → Activated carbon filter → Softener → Precision filter → Cationic resin filter bed → Anionic resin filter bed → Cationic resin mixed bed → Microporous filter → Water point

2. Adopting a two-stage reverse osmosis method, the process is as follows:

Raw water→ Raw water booster pump → multi-media filter → activated carbon filter → water softener → precision filter → first stage reverse osmosis → pH adjustment → intermediate water tank → second stage reverse osmosis (with positive charge on the surface of the reverse osmosis membrane) → purified water tank → pure water pump → microporous filter → water point

3. The process of using EDI is as follows:

Raw water→ Raw water booster pump → Multi medium filter → Activated carbon filter → Softener → Precision filter → Primary reverse osmosis machine → Intermediate water tank → Intermediate water pump → EDI system → Microporous filter → Water point

The preparation process of ultrapure water equipment usually uses ion exchange resin for production, but the use of ion exchange resin usually requires frequent resin regeneration, which consumes both material resources and labor. After years of practice and combined with new membrane separation technology, our company often adopts reverse osmosis and ion exchange systemThe combination of (or EDI) is used to prepare ultrapure water, which has the advantage of low operating costs compared to traditional processes (greatly extending the regeneration cycle of ion exchangers) and reliable operation. Compared with new processes, it has the advantages of low cost and easy availability of consumables,Advanced technology and reliability.

Equipment water inlet requirements

reverse osmosisRO produces water with a conductivity of less than 20 μ s/cm.

pHValue:7.5—9

Temperature:15℃--35℃

Inlet pressure（DIN）：0.15—0.4MPa

Inlet hardness:＜1.0ppm (calculated as CaCO3) (recommended below 0.5ppm)

Inlet organic matter:TOC＜0.5ppm

Inlet silicon:SiO2＜0.5ppm

Total inflowCO2：＜3ppm

Inlet particle size:＜1μm