Screw and Spiral Presses



Dewatering and compacting of sieving residues play an important role in water, waste water and waste treatment not only regarding
reduction of costs for disposal and handling. Frequently, residues and recyclable fractions are dewatered and further compacted
within production inherent processes. Furthermore, dewatering systems have the additional effect to transport the material
from the source of origin to the place of disposal. PWL screw presses and PWL spiral presses meet these challenges to all
intents and purposes and allow for an optimal benefit at a small footprint. The way of dewatering and conveying as well as
the characteristics of the medium determine to a great extend the choice of the suitable equipment. Compared to the shaftless
spirals which reliably convey large and long-fibrous pieces and are robust towards clogging, screw presses achieve higher
dewatering results with the same size.


The material to be dewatered passes a hopper or an upstream conveyor and arrives at the receiving area of the press. The
spiral-shaped conveyor helix pushes the material carefully into the dewatering zone. This dewatering zone is equipped with
a sieve bottom or sieve box which allows for discharge of the extruded liquid. The press resistance is generated by an adjustable
flap/cone system or determined via a fixed friction pipe. The dewatered solids leave the press automatically and can be discharged
into a backstream conveyor unit or tank.

Your Benefit

  • many years of experience in operation
  • small footprint
  • low wear
  • dewatering of up to 50%
  • robust towards impact loads
  • robust towards clogging
  • spirals and screws made of special steel
  • custom-tailored choice of material
  • comprehensive know-how of applications from different industries
  • completed by or adapted with upstream sieving machines

Screw and Spiral Presses
PWL Screw and Spiral