Falling in the range between nanofiltration and microfiltration, ultrafiltration (UF) membrane pore size creates a barrier to bacteria and viruses whilst still allowing passage of ions. As such the mineral content of water passing through a UF membrane does not appreciably change.
UF membranes operate at much lower pressures than RO membranes and require a higher degree of cross-flow to prevent plug fouling. A more recent development in membrane technology, the cost of ultrafiltration membranes has reduced considerably in recent years, making it a much more effective cost option for a number of applications, including river extraction. UF is often used as a very effective pre-treatment to reverse osmosis.
Typically employed in hollow fibre construction, operation of UF membranes can be from outside-to-in (i.e. fed from outside the fibre with permeate collected from within) or inside-to-out, dependent upon the specific manufacturer and application. The robust construction of the fibres generally enables periodic backflushing of membranes to reduce plug fouling. Often cleaning of membranes is also enhanced by introduction of chemicals such as sodium hypochlorite or sodium hydroxide.
UF membranes are often used for the segregation of emulsified oils from chemical cleaning baths and coolants, extending operational life.
AllWater Technologies Ltd offer a wide range of ultrafiltration plants & replacement UF membranes, and have a fleet of engineers able to cater to your service and refurbishment requirements