Case Study : Re-Boiler For Energy-Efficient
Evaporator System

A steam-heated evaporation system recovers a volatile organic from a heavy organic solution laden with foulants. A hard, black scale that was forming in the upper 25% of the tubes was forcing the plant to switch two parallel once-through rising film evaporators with a clean pair every four to five days. When asked to increase throughput and simplify operations engineers considered installing a 2100-sq-ft falling film evaporator (FFE) to operate in series with the existing rising film evaporators (RFE). Although the combination system was expected to run approximately 10 weeks between cleanings, a better solution was needed.

A fluidized bed heat exchanger used as a re-boiler for an evaporator system to recover a volatile organic (82 m²)

More than 20 years in operation.
No cleanings per year required compared to the 70 cleanings per year with the conventional re-boiler (annual turnaround replaces cleaning every 4 to 5 days).
A significant cost saving results from the higher recovery of acetic acid and the more concentrated residue in the bottoms.
The re-boiler circulation rate has been constant, thus providing uniform tower operation and more total throughput.