High performance solar still

Claim 1

A high performance solar distillation apparatus for vaporization and condensation of pure water from saline and brackish waters, comprising: a. a generally flat double plate heat-exchanger base means having passage means therethrough for the flow of a heat transfer working fluid from one end of the apparatus base to the other; b. a twinwall cover means having passage means between the twin walls and being transparent to solar energy; said cover means mounted above said heat-exchanger base means so as to form a chamber between said transparent cover means and said base means; said chamber being completely enclosed by walls on all remaining sides thereof; and said twinwall transparent cover means being positioned at an incline to the horizontal when the apparatus is in operating position; c. said passage means in said heat-exchanger base means and in said transparent cover means being filled with a heat-exchanger working fluid; d. a first conduit means connecting one end of the passage means of said double plate heat-exchanger base means to one end of the passage means in said twinwall transparent cover means, and a second conduit means connecting the other end of said passage means in the twinwall transparent cover means to the other end of the passage means in said double plate heat-exchanger base means to allow complete flow of the working fluid through said heat-exchanger base means through said transparent cover means and return to the heat-exchanger base means; e. a pump means operable to continuously circulate said working fluid as desired through said heat-exchanger base means, said twinwall transparent cover means and said first and second conduit means; f. an inlet means at one end of said apparatus for introducing saline waters to flow into said chamber and across the upper surface of said heat-exchanger base means; an outlet means at the opposite end of said apparatus for withdrawing concentrated saline waters following evaporation and condensation as pure water on the inner surface of said transparent cover means of at least a portion of the introduced saline waters; g. means for activating said pump means when solar energy entering said apparatus chamber through said twinwall transparent cover means impinges upon and heats to a predetermined temperature the upper surface of said double plate heat-exchanger means and the saline waters flowing across the upper surface of the surface thereof causing certain vaporation of the water; h. said working fluid as it flows through said twinwall transparent cover operating to recapture the heat of condensation as water vapor condenses on the inner surface of said twinwall transparent cover means; i. means for collecting said pure water condensation and removing same from said chamber; j. said working fluid from said twinwall transparent cover means flowing though said double plate heat-exchanger base means in turn giving up its recaptured heat of condensation to enhance the vaporization of additional saline water flowing across the upper surface of said heat-exchanger base means.