The D-Series family of proprietary thin-film nanofiltration membrane elements is characterized by an approximate molecular weight cut-off of 150- 300 Dalton for uncharged organic molecules. Divalent and multivalent anions are preferentially rejected by the membrane while monovalent ion rejection is dependent upon feed concentration and composition. Since monovalent ions pass through the membrane, they do not contribute to the osmotic pressure, thus enabling D-Series nanofiltration membrane systems to operate at feed pressures below those of RO systems.
The DK membrane has a minimum rejection of 98% on 2,000 ppm MgSO4 at 25°C (77°F) and 110psi operating pressure.
The Dairy Processing DK Elements are typically used in food related processes requiring stringent sanitary procedures. Applications include lactose desalting, deacidification and demineralization of whey or UF permeate.
These elements feature a Durasan* Cage patented outer wrap, a selection of feed spacers, and polysulfone parts.
The Dairy DK elements comply with:
• FDA Regulations relevant sections of 21CFR
• EU Framework 1935/2004/EC
• Halal and Kosher certifications
Typical Operating Pressure: 70-400psi (483-2,757kPa)
Typical Operating Flux: 5-20 GFD (8–34 LMH)
Clean Water Flux (CWF) (1): 14 GFD (24 LMH) @ 110psi
Maximum Operating Pressure: 600psi (4,137kPa)
Maximum Permeate Pressure (2): 60 psi (413 kPa)
Maximum Temperature: 122°F (50°C)
pH Range: 3.0-9.0
Recommended Pressure Drop:
Over an element: 12psi (83kPa)
Maximum Pressure Drop:
Over an element: 15psi (103kPa)
Per housing: 60psi (414kPa)
CIP Limits for Nanofiltration Membranes:
Temperature: 50°C (122°F)
pH Minimum: 2.0
pH Maximum: 11.0
Chlorine Tolerance: 500 ppm-hours dechlorination recommended