Rotating disk filter for low energy wastewater treatment

Scientists at the Fraunhofer IGB have developed a rotating disk filter, which efficiently controls the thickness of the particle layer formed during filtration by rotation of its filter disks. Hereby, the filter opens up new applications for membrane filtration such as industrial and municipal wastewater treatment.

The membrane disks of the rotating disk filter are preferably made of ceramic material. Ceramic material is characterized by high specific filtrate fluxes and good cleanability.

Running rotating disk filter, Fraunhofer IGB.

Scientists at the Fraunhofer IGB have developed a rotating disk filter, which efficiently controls the thickness of the particle layer formed during filtration by rotation of its filter disks. Hereby, the filter opens up new applications for membrane filtration such as industrial and municipal wastewater treatment.

The membrane disks of the rotating disk filter are preferably made of ceramic material. Ceramic material is characterized by high specific filtrate fluxes and good cleanability.

Principle of operation

The rotating disk filter is a dynamic membrane filter consisting of a cylindrical housing, in which a stack of membrane disks is attached to a rotating hollow shaft. By applying a slight overpressure of 0.2 to 1.5 bar the filtrate passes through the separation layer on the membrane disk outside in and is drawn off via or along the hollow shaft.

The particle layer on the membranes is controlled by means of the centrifugal force field created. This enables the laminar particle layer – adhering on the filter disk and thereby rotating together with the disks – to flow off. Thus, the particle layer is continuously renewed. By avoiding of turbulences, energy consumption of the rotating disk filter is low.

Advantages

  • High specific filtrate fluxes
  • Robust against blockages and clogging
  • Low energy consumption
  • Long operating times, easy to clean

Applications

The rotating disk filter proofed successfully in:

  • Filtration in sludge digestion
  • Filtration of activated sludge
  • Filtration of raw wastewater
  • Filtration of blackwater (wastewater from toilets)

Further applications are:

  • Emulsion splitting
  • Pre-filtration for sampling systems