Single-effect Evaporators: Summary

The answers to the ConcepTests are given below and will open in a separate window. 
Key points from this module:
  • For a single effect evaporator, approximately 1 kg of steam is needed to evaporate 1 kg of water from an aqueous solution, but this depends on the liquid feed temperature and the evaporator pressure.
  • Steam economy depends on the steam temperature and the liquid feed temperature.
  • As pressure increases, the boiling point increases.
From studying this module, you should now be able to:
  • Solve mass balances for a single-effect evaporator.
  • Solve energy balances for a single-effect evaporator to determine flow rates of steam, flow rate of liquid feed that can be processed, flow rate of concentrated liquid leaving evaporator, and/or heat transfer area needed for desired evaporation rate.
  • Calculate steam economy.
Prepared by John L. Falconer, Department of Chemical and Biological Engineering, University of Colorado Boulder