Knoll Maschinenbau GmbH – Lager und Produkte

Neither too much nor too little

KNOLL HydroPur for custom-tailored cooling lubricant filtration

Neither too much nor too little

If you want to configure a filter system precisely according to your needs, you will be love the newly developed KNOLL HydroPur. The basic model of this modularly structured hydrostatic filter system consists of a tank and a filter upper part. Depending on your requirements with regard to pumps, coolers, pre-separators, etc., you can select standardized function modules – for easy outfitting up to the full version, which can fulfill even the most demanding requirements.

The KNOLL HydroPur is a system with hydrostatic filters for machine tools that produce chips. It handles the cleaning and tempering of the cooling lubricant and supplies the machine with clean cooling medium. Due to its great filter fineness, it is especially well-suited for use for grinding processes.

A filter fleece, which combined with the hydrostatic principle separates liquid and chips, ensures effective filtration with many benefits as compared to simple filters. The KNOLL HydroPur easily removes chips of any type – even of light alloys. Its strengths include low residual moisture in the fleece and dirt removal, minimal disposal costs, and very low cooling lubricant loss.

The highlight of the KNOLL HydroPur is its modular structure. It is designed as a standard product, which allows the configuration of different variants with no additional effort. Customers can configure a complete product tailored to their needs using function modules with regard to pumps, coolers, pre-separators, winding unit, etc. – without superfluous functions. Thanks to the use of standardized modules, KNOLL is in a position to deliver the HydroPur quickly and at especially attractive conditions. In addition, the filter can be put into service easily and quickly, almost plug & play.

Operation of the HydroPur is also easy and very intuitive,for KNOLL has deployed its new SmartConnect operating concept here. This means that a small industrial PC is connected to the system PLC via a 7" touch display. SmartConnect also has app connectivity, so that the operator can also access the filter system, visualize states, and check and change parameters using mobile end user devices such as smartphone or tablet.


The plus points of the HydroPur

  • Easy configuration from function modules
  • Quick installation and start-up
  • Flexible use with different chip sizes and materials
  • High filter fineness
  • Easy, intuitive operation
  • Short amortization period


Here's how the KNOLL HydroPur filter system works:

The machine tool's lifting pump or a lifting station conveys the contaminated cooling lubricant to the HydroPur's feed box and it moves from there to the filter fleece. Due to the hydraulic pressure, the fleece allows the cooling lubricant to pass through, but it holds back chips and foreign bodies. These form a filter cake, which as it becomes thicker reduces the flow volume due to the filter surface. The level of contaminated fluid increases up to a defined height, then the belt drive switches on and conveys the filter fleece a little further. This allows clean filter fleece to reach the filter surface, the flow volume increases and the level of contaminated fluid is reduced again.

After moving out of the contaminated liquid, the fleece moves with the accumulated filter cake over a drying line before reaching the collection container. Optionally, KNOLL offers a winding unit for the used fleece combined with a scraper that separates the filter cake in the container. The clean cooling lubricant flows into the clean tank. From there, up to three pumps supply the machine tool with clean cooling lubricant as needed.