Refiner system - Type PR

The PALLMANN refiner system produces high quality fibers from chips, saw dust, shavings, and annual plants for MDF, HDF, and insulation board production. PALLMANN supplies complete plants consisting of perfectly coordinated components to ensure the highest fiber quality with minimal energy input.

Chip bin for pre-steaming of chips:

• The closed design of the bin with downward tapering base is equipped with vibrating motors to ensure a continuous discharge. Circular steam injection results in perfect pre-tempering of the chips.

• Integrated load cells allow the online presentation of the filling level of the chips inside the bin.

• The extremely heavy and robust plug screw feeds the chips reliably into the digester and squeezes out excess water by doing so.

• The position compensation, caused by the thermal expansion of the digester, can be safely implemented by the special design of the robust base frame.

• Due to the extended high-compression zone, a very even moisture adjustment can be ensured. 

• The blow-back safety valve is located across from the plug screw. In the case of a production stop or a scarce supply with chips, this valve seals off digester and plug screw from each other.

• This action is implemented by means of an extremely robust, pneumatically controlled steel cylinder.

• The digester, made of stainless steel, is designed according to the pressure equipment directive.

• The effective volume of up to 20 m³ allows a gentle and safe moistening of the chips.

• Due to its tapered shape and large base diameter, maximum protection against plugging can be guaranteed.

• The flexibly adjustable level measurement controls fully-automatically the fill level and dwell time of the chips.

• Via the frequency-controlled agitator and the refiner feed screw, chips are fed into the pressurized refiner in a precisely defined amount.  

• The Pallmann pressurized refiner is a single-disc refiner with one stationary and one adjustable rotating disc. To achieve consistent grinding conditions, the grinding segments are attached by screws from the rear and therefore generate no disruptions of the grinding segment structure. The grinding gap is controlled via a highly precise hydraulic servo system. The very narrow tolerances resulting from this allow for perfectly homogenous fiber quality.  

• For a quick change of the grinding segments, the housing is horizontally divided. Thus, the feed screw does not have to be removed when changing out the grinding segments.

• The quality and service life of the refiner bearing is unique in the industry. The hydrodynamic axial bearing can handle up to 12 MW of drive power without any problems.  

• Oil flow and pressure are constantly controlled during operation.

• The fiber discharge to the dryer can be controlled by the flexibly adjustable and high-strength discharge valve. The unsurpassed resistance to wear and the absolutely reliable adjustment via a hydraulic cylinder are the special features of this valve.

• The very robust fiber valve allows the automatic material flow changeover between production line / dryer and a startup cyclone and is completely maintenance-free.