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Two conventional solar distillers and a thermal storage system with flat plate collector are designed and fabricated at Shebin El-kom city, Egypt at Latitude of 30.58 o N and Longitude of 31.01 o E. The thermal storage system is used to collect the solar energy during daytime and store it in a thermally insulated water tank. Two types of experiments are conducted. Firstly, the productivity of conventional solar distiller through a daytime and night without heat recovery is measured. The second type prescribes measuring the productivity using both the direct solar energy during daytime and recovered the energy during night. The heat is recovered with the aid of a pumping system and through a heat exchanger immersed inside the salt water accumelated within the distiller basin. The results of two solar distillers with and without heat recovery are investigated. The daily productivity of solar distiller with heat recovery is almost twice of the conventional one. Present measurements show that the productivity of modified distiller is increased by 75, 94, 121 and 109 percentage for August, September, November and December respectively.

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Single-phase (air-air) and two-phase (air-solid) flows throngh ejector are numerically and experimentally studied in this paper. The numerical model is performed using continuity equation for the gas phase and the solid phase separately, and the momentum equation for a homogenous mixture of gas-solid flow. The model takes into account the gas and solid friction with the wall and the drag force exerted on a particle by the gas. Three different geometries of the ejector are studied numerically and experimentally. The effects of the mixing chamber and tail pipeldiffuser, geometries on the ejector performance are studied. In addition, the effects of fluid motive pressure and the solid particle mass flow rate on the static pressure distribution are also studied. Comparisons are carried out between theoretical results and the present and published experimental data for the axial wall static pressure distribution. These comparisons show good agreements. The obtained results show that, geometry of convergent-constant-divergent of the mixing duct gives high vacuum pressure and preferable performance ofthe ejector.