Data-sheet

Summary

General Description

Electrodeionization (EDI) is a continuous, chemical-free process designed to remove ionized and ionizable species from feed water using DC power. It is typically employed to polish reverse osmosis (RO) permeate, serving as an alternative to conventional mixed bed ion exchange. This eliminates the need to store and handle hazardous chemicals for resin regeneration and associated waste neutralization.

The patented OMEXELL™ EDI module features a unique, leak-free, low-maintenance spiral wound design. It contains membrane and ion exchange resins, sealed within a high-strength FRP (Fiber Reinforced Polymer) pressure vessel. OMEXELL EDI modules are designed to optimize performance, maintain continuous product quality, and can produce up to 18 MΩ-cm high-purity water with high silica and boron rejection. These modules are presented as a cost-effective alternative for post-RO deionization applications.

Advantages/Features

• No Leakage: Reliably sealed with high pressure top and bottom end caps, eliminating common leakage problems.
• Quality Control: Each module is performance and pressure tested prior to leaving the factory.
• Low Maintenance: Does not require tightening of nuts and bolts at installation or retorquing on an ongoing basis.
• Light Weight Modules, Modular, Easy Access Designs: Results in modular systems with easy access. Light weight modules are easy to handle without special lifting devices. Each module includes an individual permeate sample port.
• Cost Effective: Allows for building systems with lower capital and operating costs compared to plate and frame EDI devices, and is a cost-effective replacement for conventional mixed bed ion-exchange.

How it Works

OMEXELL™ EDI modules use electrical current to continuously force contaminant ions out of the feed water and into a reject stream. This process simultaneously regenerates the resin bed with H⁺ (hydrogen) and OH⁻ (hydroxyl) ions derived from water splitting.

Feed water (dilute stream) enters from the bottom of the module and is diverted into vertically spiraled "D" (dilute) chambers. This stream flows vertically through ion-exchange resins located between an anion membrane (allowing only anions) and a cation membrane (allowing only cations).

Concentrate enters the bottom of the module through a center pipe and is diverted into spirally flowing "C" (concentrate) chambers. DC current applied across the cells splits a small percentage of water molecules into H⁺ and OH⁻ ions, which then attach to the resin sites, continuously regenerating them. Contaminant ions in the feed water attach to their respective ion-exchange resin, displacing H⁺ and OH⁻ ions. Once within the resin bed, these contaminant ions migrate through the membranes into the "C" chambers, where they are trapped, recirculated, and bled out of the system. The purified water continues through the dilute chamber and exits the OMEXELL EDI module.

Product identification

The product referenced is the OMEXELL™ EDI-210 module.

Product water

The OMEXELL™ EDI-210 module offers the following performance specifications:

• Product Water Resistivity: ≥ 15 MΩ-cm (based on standard test solution); ≥ 5 MΩ-cm (general)
• Total Exchangeable Anions (TEA): ≤ 8 ppm (CaCO₃) (based on standard test solution); ≤ 25 ppm (CaCO₃) (general)

Actual module performance is based on specific feed water conditions.

Feed water

The OMEXELL™ EDI-210 module requires RO permeate feed water meeting the following specifications:

• pH: 5.0-9.0
• Hardness: ≤ 0.5 ppm (CaCO₃)
• Dissolved Silica: ≤ 0.5 ppm
• TOC: ≤ 0.5 ppm
• Free Cl₂: ≤ 0.05 ppm
• Fe, Mn: ≤ 0.01 ppm
• Turbidity, NTU: ≤ 0.1
• Oxidizer, mg/L: None

Operating limits

• Dilute Product Flow Rate: 6.6 to 10 gpm (1.5 to 2.2 m³/h)
• Recovery Rate: up to 95%
• Inlet Temperature: 50° to 100°F (10° to 38°C)
• Inlet Pressure (continuous operation): 36 to 80 psi (2.5 to 5.5 Bar)
• Dilute Pressure Drop: 22 to 36 psi (1.5 to 2.5 Bar)
• Concentrate Inlet Flow: 2.2 to 4.5 gpm (0.5 to 1.0 m³/h)
• Concentrate Pressure: 7 to 10 psi (0.5 to 0.7 Bar)
• Electrolyte Flush: less than dilute pressure
• Concentrate Conductivity: 250 to 600 µs/cm

Electrical

• Maximum Electrical Current: 9A
• Maximum Working Voltage: 160V DC

Mechanical / hydraulic

The modules feature a modular design, allowing for the combination of multiple OMEXELL™ EDI modules (e.g., EDI 20, EDI 30, EDI 100, EDI 140, EDI 320) to build systems of varying sizes.

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Disclaimer: This summary is based on the provided text extract and may not include all figures, footnotes, or the latest revisions of the OEM datasheet. For contractual data and complete specifications, refer to the official PDF revision used on your project.

Official datasheet (PDF)

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