Inverted trickle solar still: effect of heat recovery

The inverted trickle solar still, which has been recently developed, is imp roved mainly by adding a heat exchanger inside the condenser. The exchanger recovers part of the heat released in the condensation process and utilize s it in heating the saline water Feed. This improvement, in addition to ins ulating the sides of the still and increasing the flow rate of the saline w ater Feed, resulted in increasing the productivity from about 2.5 l/d to 2. 8 l/d during the month of May. This improvement, which amounts to about 12% , is related mainly to the condensate production. This productivity was als o increased by about 42% for a flow rate increase of 50%. A mixture of cond ensate and intermediate product at a rate of 8.2 l/d and a salinity of 7130 ppm may be obtained, which is suitable in some types of agriculture.