By Bill Christensen
06 June 2005
http://images.livescience.com/images/050606_breathe_01.jpg Alan Izhar-Bodner, an Israeli inventor, has developed a way for divers to breathe underwater without cumbersome oxygen tanks. His apparatus makes use of the air that is dissolved in water, just like fish do.
The system uses the “Henry Law” which states that the amount of gas that can be dissolved in a liquid is proportional to the pressure on the liquid. Raise the pressure - more gas can be dissolved in the liquid. Decrease the pressure - gas dissolved in the liquid releases the gas. This is exactly what happens when you open a can of soda; carbon dioxide gas is dissolved in the liquid and is under pressure in the can. Open the can, releasing the pressure, and the gas fizzes out.
Bodner’s system apparently uses a centrifuge to lower pressure in part of a small amount of seawater taken into the system; dissolved gas is extracted. . . .