Paper and cellulose industry

Rührwerks-know-how für Papier- und Zellstoffindustrie

From the chest to bleaching tower

System solutions by STELZER Rührtechnik for chests and stacking towers, recycling towers, fibre recycling, machine tanks, mixing tanks, bleaching towers, refiner supply tanks, screen pits, pigment dispersers, causticizing filler preparation and slurry storage

  • Blending
  • Suspending
  • De-agglomerating
  • Agitation of media with non-Newtonian flow behaviour

In paper production chests with a solids content of TS 6%, STELZER Rührtechnik recommends side-entry agitators. Central agitators installed from the top or bottom with scraper systems are used for solid contents up to TS 20%. We do not just use standard solutions but consequently apply individual adaptations and further developments that put our agitators ahead of competing products.

Highly efficient axial flow and counter-flow impellers with optimised, low shear rates ensure maximum product protection. The agitators are available as top or side-entry agitators. We calculate the size of caverns according to the characteristics of the agitated material (for example hard or soft wood) using updated rheological flow models. This allows us to provide process-optimised designs. Central agitators installed from the top can be equipped with free overhung shafts or with bottom bearings. STELZER Rührtechnik will design top agitators with fast change device for bearings on request. Side-entry agitators have reliable drive and sealing systems and fast change device to replace seals on a full chest. STELZER Rührtechnik calculates the agitators and their axial forces, bending and torque already in the design phase, unlike conventional systems that are more prone to faults. The harmonic resonance frequencies (critical rotation speeds) are eliminated from the working range of the agitator by design.

Agitation processes require individual adaptations

STELZER Rührtechnik relies on verification, prevention and further development through computer simulations and tests in the in-house laboratory to ensure optimal results. Individual solutions in close cooperation with our customers are safely based on detailed analyses (also in the field of rheology). System solutions often allow the replacement of old methods by more economical methods.

Product wetted parts for agitator shafts or agitator systems used in the paper industry are always made of stainless steel.