Mitarbeiter der KNOLL Maschinenbau GmbH montiert
Hydrostatfilter HL – KNOLL Maschinenbau GmbH

Areas of application

The hydrostatic filter HL is a fleece filter for cleaning cooling lubricants from machining processes. It is used as an individual cleaning unit (e.g. for grinding), or as supplement to chipconveying systems. The combination of vacuum technology and filter fleece reduces operating costs through low fleece consumption and reduced loss of cooling lubricant.


  • Minimum residual moisture in fleece and waste discharge, resulting in less cooling lubricant loss and reduction of disposal costs
  • Low fleece consumption
  • High filter fineness
  • Trouble-free removal of chips, including light alloy
  • All-purpose filter for different machining procedures, materials and coolant lubricants


The contaminated liquid flows through the inlet box into the filter. It then runs through the filter fleece into the filter chamber. From there the filtered medium gets to the clean tank. The vacuum pump generates a vacuum in the filter chamber. The high pressure differential at the filtering surface creates a thick filter cake (concentrate) on the filter fleece. This filter cake also acts as a filter medium and separates smallest dirt particles. As the filter cake increases, the volumetric flow through the filter surface decreases and the level of contaminated liquid rises. At a pre-defined level, the belt drive switches on and conveys the carrier belt together with the filter fleece a little further. Thereby, clean filter fleece reaches the filter surface, the volumetric flow increases and the level of contaminated liquid is reduced again. Once it has emerged from the contaminated liquid, the filter fleece runs over the drying section. The air flow absorbs most of the moisture from the fleece and dirt before they reach the sludge container. A scraper is also available as an option. It scrapes most of the dirt into the sludge container together with a winding unit for the used fleece.


Filter systems

Hydrostatic filter HL

Filter systems

Hydrostatic filter HL

User report Maegerle
User report Maegerle
pdf (1 MB)

Overview of our filter range: