Heat and mass transfer investigation in a single slope passive solar still using chemical additives

The heat and mass transfer in a solar still with a single cover angle located in Baghdad has been investigated experimentally in order to increase its efficiency and productivity. The experimental setup was fabricated using a galvanized iron sheet, with all of its sides are made from the same material and covered by a transparent glass of a 3 mm thickness. To reduce the vapor leakage to the surroundings, the solar still was sealed. The experimental tests were carried out for several months from January to June. The effect of concentrator, and the coal and chemical additives on the performance and productivity of the solar still were studied at the same time. Three depths (1, 2 and 3 cm) within the basin were tested to investigate the influence of water depth on the still productivity in close weather conditions. The experimental data indicated that the productivity and the efficiency of the still increased by 40% and 37%, respectively, in comparison with still without concentrator, and the productivity and the efficiency increased by 14% and 16%, respectively using Metilen blue. Through the study, it was noted that the reduction in the depth of the water in the basin distiller leads to an increase in the productivity and efficiency of the solar still.