In this experimental work, the performance of hemispherical distiller has been enhanced via phosphate pellets. To investigate the best approach to the phosphate pellet utilization in a basin of hemispherical distiller to achieve the highest performance, the present study was carried out in two stages. In the first stage, 250 g of phosphate pellets was arranged in a layer of 5 mm thickness placed at the bottom of the basin. In the second stage, the phosphate pellets were distributed in a homogeneous manner in basin salt water with two concentrations 1% (10 g/L) and 2% (20 g/L) without aggregation on the basin. To achieve this idea, in the first test stage, two distillers were compared, the first is the conventional hemispherical distiller which represents the reference distiller (CHSS) and the second is the modified hemispherical distiller with a phosphate layer (MHSS-PL). In the second test stage, three distillers were compared, the first is the CHSS which represents the reference distiller, the second is the modified hemispherical distiller which contained 1% phosphate (MHSS-1), and the third is the modified hemispherical distiller which contained 2% phosphates (MHSS-2). The experimental results show that the cumulative yield was 4.6, 6.32, 6.15, and 6.85 L/m2·day for CHSS, MHSS-PL, MHSS-1, and MHSS-2, respectively. The results showed that the utilization of the phosphate pellets as a storage medium enhanced the performance of the hemispherical distiller. The enhancement in the distiller productivity was 37.4, 33.7, and 47.9% for MHSS-PL, MHSS-1, and MHSS-2, respectively, compared to conventional hemispherical solar still (CHSS). The peak enhancement in the productivity was achieved in the case of modified hemispherical solar still with 2% (20 g/L) phosphate pellets (MHSS-2).
Keywords: Hemispherical distiller; Phosphate pellets; Productivity; Solar energy.