Pyramid type solar still coupled with evacuated tubes

Solar distillation is the rising method for converting saline water in to pure or clean water for drinking purpose. In this work, a new pyramid type solar still has been designed and fabricated with the still basin area of 1m2. To increase the productivity of the solar still Evacuated tubes are directly coupled with the lower side of the basin and black stones are sited inside the basin. The experimental setup is fabricated considering the geographical location of Bangalore (Latitude: 12.97°N and Longitude: 77.59°E), and the performance analysis of the solar still are conducted under the following conditions (i) Still alone, (ii) Still coupled with evacuated tubes. We obtained daily maximum distilled water of 2.1 liters for still alone, 4 liters for still coupled with evacuated tubes. It has been found that the coupled system increase the production rate by 90.47%. It has been observed that the thermal efficiency, for still alone is 21.93% and still coupled with evacuated tubes is 28.89%. The water quality analysis is also been carried out, the salt (CaCo3) content is reduced from 391.93 ppm to 5.11 ppm.