The Electro-Deionization process is the latest technology to achieve ultrapure water. EDI uses ion exchange resins in the presence of a DC voltage potential to remove cation and anion contaminants from the feed water supply. Ion selective membranes are then used within the modules to continuously remove these contaminants and carry them out in a small concentrate stream. The voltage applied across the cell allows for the electrochemical “splitting” of water into hydrogen (H+) and hydroxide (OH-) ions within the ion exchange resins resulting in constant regeneration without the addition of chemicals, wastewater neutralization/disposal, and shutdown time. This results in a major advantage over the operation of traditional, regenerable Mixed-Bed Deionization and Service Exchange DI Systems.
The following are just a few of the industrial applications that can benefit from purified water produced by EDI systems:
Power Generation
Industrial Process Water
Chemical Manufacturing
Boiler Feed
Electronics / Semiconductor
Research Lab Facilities
Operating Parameters
Nominal Recovery: 90–95%
Operating Temperature: 50–100° F
Expected Pressure Drop: 30–40 psig
EDI Water Quality: 15–18 meg-ohm
Maximum Inlet Pressure: 100 psig
Electrical Requirement: 460 VAC, 3-phase, 60 Hz. 120 VAC, 1-phase, 60 Hz.
Feedwater Requirements: See table on reverse side
Minimum Inlet Pressure: 60 psig
Materials Of Construction
Skid Frame: Epoxy-coated carbon steel
EDI cell tubing: Polyethylene
EDI Housings: FRP
System piping: Sch 80 PVC
Standard Features
Allen Bradley MicroLogix Series PLC system
NEMA-4 electrical enclosures
Product water resistivity monitor
Allen Bradley PanelView operator terminal
Electric-actuated inlet water valve
Flowmeters for product, reject, and electrolyte streams