Forced Circulation Evaporators

Climbing and falling film evaporators cannot be adapted to evaporation processes when the scaling tendency is high (the tubes have to be full of liquid, with no boiling in them). This is the only reason why Kestner developed forced circulation evaporators.

In these evaporators, the tube bundles simply serve to heat the processed liquor, which then flashes in the separator. In this case, the tubular heater can either be vertical or horizontal.

To circulate the liquor through the unit, Kestner use special pumps (axial or mixed flow pumps), which can either be installed horizontally with packed glands or mechanical seals, or vertically. In case of a vertical installation, the pump can be glandless, with a controlled leak piped back to the pumping sump, hence involving no rubbing parts.