Pulp industry

Innovative evaporation plants from SCHRADER

SCHRADER evaporation plants with innovative technology for the concentration of pulp waste liquors.

In order to recover usable ingredients from the waste liquor of your pulp production (predominantly sulphate black liquor and sulphite white liquor), an evaporation plant is used to reduce the volume of water in the waste liquor. SCHRADER provides expertise based on 50 years of experience in the design of evaporation plants for the pulp industry.

The optimisation of existing evaporation plants is increasingly important in order to reduce production costs:

  • Energy savings
  • Increase in water evaporation capacity
  • Ease of operation and maintenance
  • Highest possible degree of liquor concentration
  • Optimum separation of water and liquor

SCHRADER evaporation plants – as well as all necessary spare and extension components – offer maximum economy, operational reliability and service life. Significant improvements can, in particular, be achieved by using mechanical or thermal vapour recompression or by optimising heat exchanger surfaces.


SCHRADER turnkey plants for pulp production



waste liquor analysis,



Basic engineering
Detail engineering






test run,

Customer service

Customer service

Operational support,
spare parts,

The heating system optimisation of each evaporation plant depends on the amount of liquor produced and the available heating energy. This means that new evaporation plants can be designed with up to seven stages connected in series while existing plants can often be extended by a pre-evaporator with mechanical or thermal vapour recompression.

Plate falling film evaporators with pillow-like extended plate elements tend to be used in preliminary and main stages, depending on the amount of liquor to be evaporated and its viscosity. The flat tube heat exchanger with forced circulation specially developed by SCHRADER is suitable for concentrating the liquor in the final stage. A surface condenser is used to condense the vapours produced by vacuum evaporation in the final stage.

Evaporator types

Forced circulation evaporator

Falling film evaporator

Falling film evaporator with pillow-like extended plates

Interior view of a forced circulation stage with flat tubes

Extension of a sulphite liquor evaporation plant with 2 plate falling film stages

Heat exchanger panels

Paper pre-evaporation stage


Our global network of experienced engineers is available to you by phone or e-mail. Don’t hesitate to get in touch.