Preliminary results from the testing of an advanced passive solar still incorporating a shielded condenser

Madhlopa, Amos and Johnstone, Cameron (2008) Preliminary results from the testing of an advanced passive solar still incorporating a shielded condenser. In: 10th World Renewable Energy Congress, 2008-07-19 - 2008-07-25.

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Abstract

An advanced passive solar still with separate condenser has been studied theoretically and experimentally. The system has one basin in the evaporation chamber and two basins (middle and upper) in the condenser chamber, with a glass cover over the evaporator basin and an opaque condensing cover over the upper basin. The evaporator, middle and upper basins form the primary, secondary and tertiary effects respectively. The top part of the condensing cover is shielded from solar radiation and heat. Water vapor from the primary effect condenses under the glass cover while the remainder of it flows into the condenser, by purging and diffusion, and condenses under the liner of the middle basin. Outdoor tests of the present solar still and a conventional system were conducted at the University of Strathclyde. The two systems are also simulated under the same meteorological conditions. It is found that the solar shield effectively keeps the condenser cover relatively cool. Under favorable weather conditions the present solar still produced up to 34% more distillate than the conventional type. Experimental and estimated results are in close conformity. It appears that the new solar still can be exploited within and outside the tropical region.