NF spiral
Les membranes de nanofiltration en spirale (NF) d'Alfa Laval sont des solutions éprouvées pour la concentration et la déminéralisation à haute efficacité de produits tels que les antibiotiques, le lactosérum et le perméat d'ultrafiltration. Ils retiennent les sels de bivalence supérieure à 1, tandis que les petits sels monovalents passent dans le perméat. Ils peuvent également être utilisés pour produire des boissons à faible teneur en alcool.
Réduire les coûts de production globaux et améliorer la qualité des produits
- Fonctionnement économique grâce à une faible consommation d'énergie
- Flexibles – disponibles dans différentes combinaisons de longueur, de diamètre et de taille d'entretoise
- Efficaces – permettent le dessalement et la concentration simultanés d'une gamme de produits dans différents processus
- Encombrement au sol minimal – conception compacte
- Extrêmement durables – excellentes stabilités chimique et thermique et durée de vie jusqu'à plusieurs années
A range of nanofiltration membranes
Our nanofiltration membranes feature pores down to 300 Daltons. Operating at pressures of up to 55 bar, the membranes allow small ions to pass through the membrane, while retaining larger ions and most organic components.
NF Membrane Series
Alfa Laval offers two types of spiral membranes for nanofiltration: NF and NF99HF. Both types are made of thin film composite membrane cast on polyester support. The rejection capacity for both is ≥99% (based upon magnesium sulfate).
All types are USDA approved and we can offer products with Halal certificates upon request.
Our nanofiltration spiral membrane materials are compliant with all major regulations
Our spiral wound membrane materials are compliant with all major regulations
All membrane materials used for both flat sheet and spiral wound membrane configurations meet EU Regulation (EC) 1935/2004, EU Regulation 10/2011, EU Regulation (EC) 2023/2006 and FDA regulations (CFR) Title 21, and are suitable for use in food and pharmaceutical processing applications. Compliance also extends to the related equipment and fittings, including items such as plate-and-frame units, element housings and pumps, supporting safe and efficient spiral membrane filtration in a wide range of industries.
Fonctionnement
The basic technology behind membrane filtration involves using a semi-permeable membrane to separate a liquid into two distinct streams.
Pumping this liquid across the surface of the membrane creates a positive trans-membrane pressure that allows any components smaller than the porosity of the membrane to pass through, forming the permeate.
Any components larger than the pore size simply cannot pass through, and remain behind in what is called the retentate. The surface of the spiral wound membrane is kept free of blockages by the force of the liquid flow moving parallel to the membrane surface.
Construction of the nanofiltration spiral membrane
Efficient spiral membrane filtration
A spiral membrane comprises of several membrane 'envelopes' with two membrane sheets separated by a permeate spacer mesh, each glued to a central permeate collection tube.
Between each pair of envelopes there is a spacer which creates the feed channel, allowing the feed to flow across the length of the spiral wound membrane, whilst the permeate passing through the membrane into the membrane envelope flows in a spiral pattern to the permeate collection tube.
Red = Feed/retentate.
Green = Permeate.
The flow pattern in a nanofiltration spiral membrane where red represents the feed/retentate and yellow the permeate.