Evaporator Upgrades

The need for evaporator upgrade may result from demand for higher pulp production or better energy efficiency, tighter emission limits or changes in the pulping process.

Rinheat supplies upgrades for

  • Black liquor evaporators
  • BCTMP evaporators
  • NSSC evaporators

We have developed new technology for upgrades of black liquor evaporation plants.

black liquor evaporator upgrades

Rinheat has long experience on the reboilers for Thermo Mechanical Pulping (TMP) Process and evaporators for the liquor from Chemi Thermo Mechanical Pulping (CTMP) plants. On the basis of this knowhow we have developed better main constructions for the black liquor evaporation:

  • OT Concentrator    with liquor flow on the outside of the vertical tubes
  • CS Evaporator       with condensate stripping
  • CC Condenser       with counter-current flow

The patent for OT Concentrator and CS Evaporator has been awarded and the patent for CC Condenser is pending. Rinheat evaporators have the following common benefits and features:


  • Good quality secondary condensates
  • Low steam consumption
  • High dry solids
  • Small foot print

key technology features

  • Non-plugging tubular OT Concentrator
  • Good secondary condensate segregation in CS Evaporator
  • Efficient falling film CC Condenser
  • Integrated foul condensate stripper


  • More capasity and steam saving through additional effect on the existing evaporation train
  • Retrofitting new heat transfer surface into an existing body