Operating modes
Membrane filtration (RO, NF, UF) - Installation and performance

Membrane separation operations in the liquid phase, where the acting force is a pressure difference, can be carried out in two main ways:

• by imposing a setpoint on the filtration flow ;

• by imposing an average pressure difference across the system.

Generally speaking, controlled flow operation is considered to prevent the application of a medium set pressure, chosen for the remainder of a production cycle, at the start of the test, when the membrane is still clean and therefore of high permeability, from causing a very high flow rate and thus material accumulation and compression on the filter, leading to irreversible clogging, which conditions the plant's performance throughout the remainder of the cycle. Constant-flow...