A FLOATING-WICK TYPE SOLAR-STILL

Based on the good capillarity of a jute wick, a new type of solar still has been proposed. This type is simply a conventional solar still provided with a blackened jute wick floated with a polystyrene sheet. The floating unit was arranged not to appear more than 1/2 cm above the water level in the still. This ensures sufficient water flux, due to water suction by the capillary action of the jute fibres. To control the expected salt accumulation on the wick surface, the jute cloth was prepared in a corrugated shape. Thus salt accumulation will be restricted to the upper parts. Both azimuth and altitude tracking were used to receive maximum solar radiation incident on the still. For azimuth tracking, the still was designed to rotate by means of small casters. Altitude tracking was performed by pivoting a flat mirror about a horizontal axis. Results of this study showed that the floating-wick type solar still gives higher productivity than the common tilted-wick type and the conventional basin-type solar stills, with fewer problems in operation and maintenance. The maximum daily output of this proposed new still is 10.5 1 m(-2). Recommendations have been made to utilize this type of still as split units to meet the drinking water requirements for families living in remote or isolated regions.