Areas of application
The MicroPur® is a backflush filter for separating superfine impurities from oils. The ideal area of application is tool grinding of hard metal and HSS. In addition to standardised plants for single or several machines, KNOLL offers individual central plants for entire fields of production. Because of its ability to recover valuable raw materials without filter aids, its low power consumption and its low maintenance costs, the filter is particularly economical.

Properties
High filter fineness (1-3 µm)
Fast and effective regeneration cycle, low backflush volume
Energy-efficient backflush without air
Easy to maintain thanks to good accessibility and fast replacement of filter cartridges
Inexpensive, back-flushable filter cartridges
Energy-efficient, demand-controlled pump control
Flexible modular system requiring minimal space

Function

Filtering
The filter pump delivers the cooling lubricants tangentially into the filter bowls. Centrifugal force causes larger solids to accumulate already on the housing wall. Then the fluid flows through the filter cartridges from the outside inwards and reaches the filtered-coolant tank in the form of filtrate. A filter cake (concentrate) forms on the surface of the filter cartridge; this filter cake supports microfiltration like an additional deep-bed filter.

Regeneration
The growing filter cake causes a reduction in the volumetric flow or an increase in the pressure differential at the filter cartridge. The regeneration phase starts in response to pressure or time control: the feed valve closes and the drain valve opens. The flush pump conveys for a short time the filtered fluid from the inside outwards through the filter cartridge. This dissolves the filter cake and flushes the particles into the drain tank. The fluid is further concentrated by a downstream facility for sludge preparation.