Patent ID: 8580085

Claim:
A process for distillation to recover potable water, comprising: providing a solar distillation still having a light-transmitting roof top with an inside surface, a water transport tube with an outside surface, an inlet and an outlet, a potable water collection device positioned below and aligned with the tube such that potable water condensing on the outside surface of the tube will drip into the collection device, and an inclined heating surface positioned underneath the roof top and adapted for receiving a flow of non-potable water therealong, the heating surface having an upper end and a lower end; operating the solar distillation still through a cycled arrangement alternating between a day cycle and a night cycle; wherein the day cycle includes: drawing non-potable water from a cold water environment at a first temperature; directing the non-potable water from the cold water environment into the inlet of the tube and passing the non-potable water through the tube; releasing a first portion of the non-potable water exiting the tube onto the heating surface at the upper end so that the first portion of non-potable water flows down the heating surface toward the lower end, whereby the non-potable water flowing down the heating surface is solar heated to a second temperature, higher than the first temperature, and a portion of the non-potable water evaporates, condenses as potable water on the outside of the tube, and drips into the potable water collection device; and continually recycling the remaining non-potable water along the heating surface; wherein the night cycle includes: drawing non-potable water from a hot water environment at a third temperature higher than at least the first temperature; releasing the non-potable water from the hot water environment onto the heating surface at the upper end so that the non-potable water flows down the heating surface toward the lower end, whereby a portion of the non-potable water evaporates, condenses on one or both of the outside surface of the tube and the inside surface of the roof top to be collected as potable water; and directing the remaining non-potable water at the lower end of the heating surface to the cold water environment.