Solar stills

Abstract

The specification discloses a solar still module (10) for use in a solar still arrangement for producing a desired condensate from a feed treatment liquid, the solar still module (10) having a treatment chamber (85) including a treatment member (18) positioned below an upper solar energy transmission wall (35) to receive, in use, solar energy there through, the solar still module (10) having a treatment liquid supply (27) supplying treatment liquid to an upper end (26) of a first region (25) of the treatment member (18) to flow in a liquid film flow gravitationally downwardly there over while a component of said treatment liquid is at least partially evaporated and condensed to form a condensate (53) on an inner surface (81) of the upper solar energy transmission wall (35), the condensate (53) flowing gravitationally downwardly on said inner surface (81) of the upper solar energy transmission wall (35) to be collected at a lower location by condensate collection and discharge means (54, 57), the upper solar energy transmission wall (35) being formed by a clear or highly translucent polymer material with the inner surface (81) being hydrophilic relative to said condensate, said treatment member (18) being formed by a thin metal material as a tray having a tray base (19) forming said first region (25), a perimeter wall (20) extending upwardly from the tray base along at least side edges and lower edges of said tray base (19), and an outwardly extending flange (21) extending from an upper region of said perimeter wall (20), said flange (21) being supported on a support frame (11).