Mitarbeiter der KNOLL Maschinenbau GmbH montiert Vakuumfilter VLO
Filteranlage Vakuumfilter VLO - KNOLL Maschinenbau GmbH

Areas of application

The vacuum filter VLO is suited for cleaning cooling lubricants (CL) for grinding processes. A typical application is profile and gear grinding with processing oil. Due to its easy scalability the filtration unit can be used locally for individual machines or centrally for machine groups. In any case the result is clean oil as well as pure, dry concentrate. And all this without using filter aids.


  • Pure concentrate with low residual moisture
  • Continuous filter process without reverse flushing interruption
  • Scaling of filter capacities from 300 to 900 l/min (oil) with the same floor space possible
  • Subsequent extension of the unit possible
  • Redundant design of the filter modules possible
  • Different filter qualities per filter module possible


Filtration process

A lifting pump conveys the contaminated liquid into the inlet box. After having been cleaned, it flows from there through the endless belt into the filter chamber and afterwards into the clean tank. The filter pump creates a vacuum inside the filter chamber. Due to the high pressure difference on the surface of the filter, a thick filter cake (concentrate) forms on the endless belt. This filter cake acts as a filter medium and separates smallest dirt particles. 

Filter belt regeneration

The growing filter cake increases the flow resistance through the filter surface, causing the vacuum inside the filter chamber to rise. When the level reaches a selected threshold value, the belt drive switches on and conveys the endless belt a little further. Thereby, permeable endless belt reaches the filter surface and the volumetric flow increases again. 

The endless filter belt passes through the following stations:

  1. Filtration section (separation of dirt particles)
  2. Drying section (extraction of liquid from the concentrate)
  3. Brush-off device (removal of coarse particles)
  4. Backflushing device (removal of superfine particles)


Filter systems

Vacuum filter VLO

Overview of our filter range: