The DTNF plate tube module stacks octagonal NF membrane cushions between plastic spacer plates. The plates support the cushions but leave a fully open, radial flow channel; the flow reverses by 180° over each cushion, and the resulting turbulence prevents concentration polarization, scaling and fouling. The open channel also reduces the need for pre-treatment.
Key features
- High-strength design, up to 75 bar with high salt rejection
- Open channel feed path reduces pre-treatment and fouling
- Very short flow path, about 3 inches, between reversals
- Minimal contact between the plates and the membrane surface
- Supplied with membranes, discs, stainless steel center rod, high-pressure vessel, inlet/outlet pipes and accessories
How the disc tube module works
Feed water enters the pressure vessel and reaches the first disc after a very short distance. It flows across one side of the membrane cushion, turns 180° and flows back over the other side, then passes to the next disc. The flow path between reversals is only about 3 inches, and the raised points on the hydraulic discs create strong turbulence. This self-cleaning effect reduces scaling and fouling and extends membrane life.
Each membrane cushion consists of two membrane discs with a polyester spacer, joined by ultrasonic welding so that the liquid never touches glue or other materials. Cushions are available in round or octagonal shape, for seawater (SW) or brackish water (BW).
