05-11-2012, 03:31 PM
Solar Still
SolarStill.pdf (Size: 39.64 KB / Downloads: 56)
Objective
To collect water wither in dry regions or as a means of purifying water where the only available
water is undrinkable.
Design
Consists of a 120cm square hole, about 60cm deep, covered by a 2m2 sheet of plastic, weighted in
the middle with a stone. Below this is a water container. A pipe can be used to facilitate emptying.
Theory
The solar still works best in hot weather over moist ground or with
foliage in the pit. The heat is trapped under the sheet and causes moisture to rise. The water condenses from this vapour and runs down the sheet and drips off the centre below the stone and into the container. Black plastic captures the most heat.
Advantages
Pure water where it is otherwise dirty or absent. Can also be used to
distill fresh water from salt water.
Disadvantages
The distilled water can taste unpleasant, but it’s safe and clean.