In this configuration the hot solution (feed) is in direct
contact with the hot membrane side surface. Therefore, evaporation
takes place at the feed-membrane surface. The vapour is moved by
the pressure difference across the membrane to the permeate side
and condenses inside the membrane module. Because of the hydrophobic
characteristic, the feed cannot penetrate the membrane
(only the gas phase exists inside the membrane pores). DCMD is the
simplest MD configuration, and is widely employed in desalination
processes and concentration of aqueous solutions in food industries,
or acids manufacturing . The main drawback of this design
is the heat lost by conduction