Process for the purification of water

A process for the purification of water comprising:

• a. feeding water onto a solar heat absorbing surface so as to form a sheet of water thereon,
• b. feeding a liquid which has a density and vapor pressure less than said water, onto said sheet, so as to form a layer of said liquid on said sheet, which functions at least to transmit solar radiation to said water,
• c. preheating said water by direct solar radiation,
• d. further preheating said water by reflected solar radiation and forming a still air blanket over said layer with reflection and still air blanket producing means,
• e. conducting step (c) and (d) simultaneously, so as to produce preheated water,
• f. feeding said preheated water from said sheet to an evaporator means,
• g. evaporating at least a portion of said preheated water within said evaporator means, to form water vapor,
• h. feeding said water vapor to a condenser means,
• i. condensing water vapor so as to recover a purified water product therefrom.