Nanofiltration System (NF) with SW – Spiral Wound Membrane
NF is relatively new in membrane techniques and is more suitable especially for demineralization. In NF, lactose and colloidal ions are retracted as much as possible in the retentate, and ionic salts pass to the permeate. Purification of fluids such as whey, permeate or skimmed milk, especially from their ionic salts is called “desalination”.
Sodium content of the (non-fat) milk that is the material for production of low-sodium yoghurt can be reduced by NF. NF is also used to minimize salt and lactose when obtaining whey concentrate to be used in products such as baby formulas.
Nanofiltration offers a wide range of possibilities for demineralization and concentration of different dairy products.
Features
Distinguishing properties of spiral wound (SW) system are as below:
- Low plant investment
- Less space required
- Easy membrane replacement
- Hygienic design
SW membrane has a unique design where the large membrane area can be wound to a compact element.
SW elements:
- Variable diameter (3.8,-8 inches)
- Variable lengths (38,-40 inches)
- Variable feed spacer (20-50 mil)
- Special design for high pH/high temperature CIP.
- Variable salt extraction (RO/NF) and lactose extraction (NF)
Membrane elements are fixed inside a structure made of stainless steel in order to create a module and to create certain number of modules installed in a plant.
On the basis of modular and proven components, each plant is organized to fit each application. Furthermore, plant design provides access to maintenance of all vital parts while providing effective costs in organization.
RO and NF plants with SW membrane elements can be provided with a process automation type ranging from a simple and manual process automation to a fully automated system integrated with the whole factory control system.
The most suitable membranes should be selected for each application.