An Experimental Study on Solar Still with Sponge Liner

The conventional desalination technologies like multi stage flash, multiple effect, vapor compression, iron exchange, reverse osmosis, electro dialysis are expensive for the production of small amount of fresh water, also use of conventional energy sources has a negative impact on the environment. Solar distillation represents a most attractive and simple technique among other distillation processes, and it is especially suited to small-scale units at locations where solar energy is considerable. An experimental study was conducted on a single slope basin solar still at the campus of Adhiyamaan College of Engineering, Hosur, Tamilnadu, India. The inner dimension of the still is 1m x 0.5m (effective area is 0.5 m²). The glass cover was tilted at 10° with respect to the horizontal. Twelve numbers copper-constantan thermocouples were installed in the still to measure the glass cover temperature, the chamber temperature, the water temperature and the ambient-air temperature, inner and outer wall temperatures etc. The hourly amount of extracted distilled water, the various temperatures and the insolation were monitored for a three month period (March-April 2008). Two types of measurements were performed on the solar still during the period in the same climatic conditions; one is sponge sheet placed on the inner wall surfaces (Back wall and side wall) and other is without sponge sheet. After placed a sponge sheet on the inner wall surfaces, it was found that, (i) the productivity of the solar still is 15% higher than the conventional still, (ii) Saline water temperature in the still with sponge sheet is raised about 65.9°C which appreciable reduces the heat losses from the still compared with conventional still water temperature of about 72.6°C. The performance characteristics of both operations show that the productivity of the still can be increased with decreasing water depth.