Plate falling film evaporator

Plate falling film evaporators

Plate falling film evaporators are one of our core competences and are characterized by excellent quality, best energy values, highest condensate quality and above-average operating times.

Years of design experience, automation of processes and welding know-how enable plate falling film evaporators to be globally competitive.

Advantages of Plate Falling Film Evaporators

  • Low to no soiling through self-cleaning effect and easy cleaning options
  • good separation of the liquid and vapor phase
  • integrated mist eliminator without separate device
  • Slow flow rates result in low pressure loss and low energy consumption
  • Low circulating pump power necessary
  • Possibility of condensate separation by secondary heating surfaces
  • Very high evaporation capacities possible (up to 500 t / h)
  • Worldwide assembly possible through optimized design of the plate bundles for standard containers
  • Efficient and fast construction

Applications of Plate Falling Film Evaporators

  • Concentration of sulphate  & sulphite lye
  • Concentration of pulp of pulp production for the regenerated fiber industry
  • Concentration of lignosulfonates
  • Concentration of bleaching water
  • Recovery of solvents from the regenerated fiber industry
  • Concentration of xylose

General application areas

  • Recovery of solvents & alcohols
  • Separation of water, solvents, alcohols and much more.
  • Recovery of recyclables
  • Volume reduction of liquid-liquid mixtures
  • Separation of multi component mixtures
  • and much more.

 

Model & Principle of the plate falling film evaporator

Falling film evaporators use gravity to convey the medium evenly over the heating surface from top to bottom and are therefore very energy efficient in operation. In the case of the plate falling film evaporator, the medium is passed over the heating surface of the plate bundle (1) heated from the inside in order to concentrate and evaporate it. Through the appropriation cup (2) guarantees uniform stacking of all heating elements. The circulation pump (3) and the re-circulation lines (4) convey the medium in a circle and is thus further evaporated. Evaporation of the more volatile liquid at the heating surface produces vapor vapor which escapes horizontally from the plate bundle and is conducted counter-currently upwards through the vapor outlet. Due to the available evaporator body, The resulting slow flow rate, the medium opposite Brüdendampfstroms a very good separation of the liquid and vapor phase is achieved, which is why this type of evaporator operate very efficiently and state of the art. Finally, the entrained droplets of the medium are separated in the Brüdendampf by a mist eliminator (5). The Brüdendampf can then be used to heat the plate bundle through the steam inlet (6) of the next evaporation stage at a Mehrstufeneindampfung or be used by mechanical vapor compression (MBV) or thermal vapor compression (TBV) in the same evaporator stage for heating the heating elements. The condensed Brüdendampf (condensate) inside the heating elements is finally collected and discharged by a condensate collector (7) at the lower end of the plate bundle. The concentrate (8), on the other hand, is drawn off at the lower end of the vaporizer body and directed to the next vaporizer stage or the next process stage.

 

Possibilities of obtaining two condensate qualities

If the vapor is not introduced at the top, but at the bottom in the plate bundle and Naschschaltheizflächen realized on the heating elements, so a condensate separation of foul condensate and pure condensate can be realized in the plate bundle.

As a result, volatile substances such as methanol can be separated in the heating element, as by the counter-current vapor flow upstream and the condensate down a stripping is achieved and accumulate the more volatile phases in the upper part of the Nachschaltheizfläche. The pure condensate can then continue to be used in the process and the contaminated digester condensate can be cleaned or incinerated.