Known for delivering advanced and reliable desalination plants, Doosan is one of the few companies in the world that offers proprietary technologies for all three main desalination processes: Multi-Stage Flash (MSF), Multi-Effect Distillation (MED), and Reverse Osmosis (RO).
With the MSF (Multi-Stage Flash) method, sea water flows through a multi-level heat exchange system, is heated with steam from the power generating plant until evaporation, and is then condensed on the outside of pipes through which cold seawater flows.
The MSF method generates fresh water from seawater using flashing which is a phenomenon of instantaneously discharging water vapor. MSF is a facility designed to use energy more effectively by continuously generating flashing of seawater at low steam pressure from each stage without the addition of heat source.
MED (Multi-Effect Distillation) is similar to MSF, but only makes use of devices called Effect instead of “Stage” from MSF. The MED method has the advantage of reducing energy consumption if applied with dump heat, and is mostly used for medium-capacity desalination plants.
Its principle is to spray seawater on the outside of metal tubes to condense the vapor flowing inside. The seawater outside the tube boils to generate steam which flows into the tubes to condense in the next cycle. The process is then repeated. Since the outside of the tubes is maintained in a vacuum, the seawater boils even when it is sprayed at a low temperature. The big difference from MSF is that it is relatively smaller in size as it is operated at low temperatures (60 ~ 70 ℃) but is more efficient and consumes less electricity per unit production.