On Sat, 29 Sep 2007 14:42:17 -0000, "jim.isbell"
wrote:



Ah well, another great idea skuppered by dat old devil science :-)

Bruce in Bangkok
(brucepaigeATgmailDOTcom)


A 32' column of water is a continuous vacuum pump. As long as you put
water (salt water) into the column it will pull down and keep a vacuum
in the top of the column. The fresh water distills off the top of the
sal****er column then migrates as steam to the other side and distills
in the fresh water side....also creating a vacuum. You draw off the
fresh water on one side and pump salt water into the other side. The
salt water side is painted black to absorb sun heat and the fresh
water side is painted white to reflect the suns heat. You only need a
few degrees difference for distillation and the vacuum creates the
boiling at low temperatures...even ice will change state to steam in a
vacuum. The idea works.

In a practical sense, I would use soft tubing for the sides and a
solid "U" shaped piece of copper tubing for the top center with a ring
soldered to it so it could be hoisted up the mast of a sailboat. It
would take a 30 to 40 foot mast to do the job. The bottom end of the
salt water tube could go to a through hull for a continuous supply of
salt water and the bottom end of the fresh water tube could go to a
small pump to remove the water without breaking the vacuum.

What you describe is just a still, and a 32 ft inverted U will change
nothing. Solar stills are not new. A tall boiler connected to a very
tall cond