Dow Filmtec NF-400 40 inch × 8 inch Nanofiltration Membrane
- Dow Filmtec NF-400 element is a durable polypiperazine amide membrane designed to reject organics with a molecular weight above 200 while passing monovalent salts.
- FILMTEC NF-400 membrane elements are used in a variety of applications such as desalting organic compounds, acid processing, metal recovery and antifreeze recovery.
- FILMTEC NF-400 membrane elements replace discontinued NF45 elements.
- Part number: 151544
- Active area - ft2 (m2): 400 (37.2)
- rate, gpm (m3/h): 70 (16)
- rate (%): 15
- Maximum operating temperaturea: 113°F (45°C)
- Maximum operating pressure: 600 psig (41 bar)
- Maximum pressure drop: 15 psig (1.0 bar)
- pH range, continuous operation: 3 - 10
- pH range, short-term cleaninga: 1 - 12
- Hydrogen peroxide: < 0.1 ppm, 20 ppm
- Continuous operation: (@ 77°F/25°C max.)
Permeate flow and salt rejection based on the following test conditions: 2,000 ppm MgSO4, 130 psig (8.9 bar), 77°F (25°C), pH 8 and 15% recovery.
Target water flow rates for new elements are: NF-2540 - 920 gpd (3.5 m3/d), NF-4040 - 3,050 gpd (11.5 m3/d), NF-400 - 13,700 gpd (51.9 m3/d).
Minimum MgSO4 rejection is 98.0%. Stabilized rejection is >99%.
Product specifications may vary slightly as improvements are implemented.
Depending on the application requiremnts, new NF spiral elements may be cleaned prior to initial use. The cleaning procedure should be based on the application for which the elements are to be used. If cleaning with formulated agents is not available, an alkaline wash with wetting agent is recommended prior to initial use.
An appropriate alkaline wash consists of the following:
- Flushing with water (ensure water quality meets guidelines found in bulletin 609-00077).
- Heating water to 113°F (45°C) in recirculation made.
- Adding 0.2% Na-EDTA and NaOH to pH 11 and recirculating for 30 minutes.
- Flushing with water until neutral pH is obtained.
Avoid any abrupt pressure or cross-flow variations on the spiral elements during start-up, shutdown, cleaning or other sequences to prevent possible membrane damage. During start-up, a gradual change from a standstill to operating state is recommended as follows:
- Feed pressure should be increased gradually over a 30-60 second time frame.
- Before initiating cross-flow at high permeate flux conditions (e.g., start-up with high-temperature water), the set operating pressure should be maintained for 5-10 minutes.
- Cross-flow velocity at set operating point should be achieved gradually over 15-20 seconds.
- Keep elements moist at all times after initial wetting.
- If operating specifications given in this Product Information bulletin are not strictly followed, the limited warranty will be null and void.
- To prevent biological growth during system shutdowns, it is recommended that membrane elements be immersed in a preservative solution.
- The customer is fully responsible for the effects of incompatible chemicals and lubricants on elements.
- Maximum pressure drop across an entire pressure vessel (housing) is 50 psi (3.4 bar).
- Avoid permeate-side backpressure at all times.