Duratherm EXL series

Summary

Product identification

The Duratherm EXL Series comprises Reverse Osmosis (RO), Nanofiltration (NF), and Ultrafiltration (UF) membrane elements, designed as Industrial High Temperature Elements. These elements are specifically engineered for industries requiring chemical-free sanitization protocols, utilizing hot water exposure.

Features and Benefits:

• Prevent bio-fouling development
• No disposal costs
• 100% wet testing Quality Assurance
• Durable construction
• Sanitization on the permeate side

Markets:

• Food / Beverage
• BioPharm
• Electronics
• Chemical

Operating limits

The elements are suitable for separation systems operating at temperatures up to 70°C (158°F). The sanitization protocol involves periodic exposure to temperatures as high as 90°C (194°F) at minimum feed pressure.

• Maximum crossflow:
  • Do not exceed 20 GFD (33 LMH)
  • Do not exceed 2,000 Wagner units
• Typical Operating Pressure: Refer to Figures 9 & 10 in the official PDF.
• Maximum Operating Pressure:
  • 1,200 psi (8,273 kPa) for 32 – 77°F (0 – 25°C)
  • 600 psi (4,137 kPa) for 78 – 122°F (26 – 50°C)
  • 400 psi (2,758 kPa) for 123 – 158°F (51 – 70°C)
• Maximum Temperature:
  • Continuous Operation: 158°F (70°C)
  • Clean-In-Place (CIP): 122°F (50°C)
  • Hot Water Sanitizing: 194°F (90°C)
• pH range:
  • Continuous Operation: 3 – 9
  • Clean-In-Place (CIP): 2 – 10.5
• Chlorine Tolerance: 500 ppm hours, dechlorination recommended.

Feed water

• NTU < 1
• SDI < 5

Mechanical / hydraulic

All element constructions include polysulfone ATD & central tube and a patented Durasan* cage outer wrap. The elements are dried then bagged before shipping. The element diameter (dimension C) is designed for optimum performance in Veolia pressure vessels.

Maximum Pressure Drops:

Element Specifications:

Note: Salt rejection and recommended crossflow values refer to figures in the official PDF.

Dimensions and Weight:

¹ Internal diameter. ³ The element diameter (dimension C) is designed for optimum performance in Veolia pressure vessels.

Hot Water Sanitization Recommendations

• Pre-use flushing: New elements must be flushed with clean water (RO permeate preferred) for at least one hour at a transmembrane pressure of not more than 45 psi (3 bar) to remove residual chemicals.
• System operation before sanitization: The system must be started and in operation for a minimum of 24 hours prior to hot water sanitization. If new elements are to be hot water sanitized before first use, the system must be flushed at low transmembrane pressure (up to 45 psi / 3 bar) for a minimum of 24 hours prior to sanitization.
• Transmembrane pressure during sanitization: Maintain as low as possible, not exceeding 45 psi (3 bar), while ensuring some permeate flow.
• Cross flow monitoring: Adjust cross flow so that pressure drop is not more than 2 psi per element or 10 psi per housing.
• Sanitization procedure:
  1. Elements that have been in operation should be cleaned with an approved Clean-In-Place (CIP) procedure and thoroughly flushed for at least one hour before sanitization.
  2. Increase system temperature from room temperature to target sanitization temperature (up to 90°C/194°F) at a rate not higher than 5°C/9°F per minute. Maintain target temperature for 30 to 60 minutes.
  3. Cool the system to room temperature at a rate not higher than 5°C/9°F per minute.
• Permeate flow loss: After repeated 90°C (194°F) sanitization cycles, a loss of 30% to 50% of the original permeate flow rate may occur before the element performance stabilizes. Over 90% of this reduction typically occurs during the first heat treatment. Salt rejection tends to increase with permeate flow rate loss.
• Factors influencing flow loss: Rate of temperature increase/decrease, presence of other species (organics, ionic, metallic compounds), feed flow rate, heat transfer rate to membrane surface, thickness and geometry of the feed spacer.

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Disclaimer: This summary is based on text extracted from an OEM PDF datasheet. It may not include all figures, footnotes, or the latest revisions. For contractual data, always refer to the specific OEM PDF revision used on your project.

Official datasheet (PDF)

PDF datasheet