Performances of pyramid-shaped solar still with different glass cover angles: Experimental study

In this study, the effects of glass cover angle on the performance of a square pyramid solar still is investigated experimentally under ambient conditions of Tanta City - Egypt (Latitude 30.47 degrees N and longitude 31 degrees E). In this work, the three type of a square pyramids solar still (system-A, system-B and system-C) with inclined angles of the condensation surface are 30.47 degrees, 40 degrees and 50 degrees respectively. The three type of a square pyramids solar still with the same absorber area of 0.64 m(2) and a glass cover in the form of a pyramid has been designed and constructed. From the present study, it is concluded that the temperature difference between the basin water and glass cover and the glass cover angles are important for designing square pyramid solar still. This exprimental results shows that the accumulated distillate water productivity up to almost 4.13 L/m(2) day in the system-A, 3.5 L/m(2) day in the system-B and 2.93 L/m(2) day in the system-C. The increase in accumulated distillate water for system-A is 41 % compared to the system-C and 18 % compared to system-B. It was found that, the accumulated distillate water productivity from the square pyramid solar stills decrease with increase the glass cover angle above the Latitude angle. The maximum accumulated distillate water productivity from the square pyramid solar stills occurs when the glass cover angle equal to the Latitude angle.