Volume 4 Issue 6

Authors: Muhammad Aamir Khan; Wasiullah Malik; Muhammad Israr; Shamsher Ali; M. Rahman; M. Ibrahim; M. Hanif; Syed Fahad Shah

Abstract: Parabolic Trough Solar (PTS) air heater was developed locally to solve the drying of persimmon with a parabolic trough and a drying box which contains a reflected steel sheet, an absorber tube, an angle iron and a fully insulated home script refrigerator. Solar irradiance results were noted for the months of Oct- Dec, 2012. Four air mass flow rates were conducted with one natural flow rate of 0.53 kg minute-1 (M-1) and three convective air mass flow rates of 1.35 kg M-1, 1.87 kg M-1 and 1.97 kg M-1 respectively. The range of temperature for the drying of persimmon was 40-60oC and less than 15% humidity was accomplished through dehydrating time. It was found that air mass flow rates and months of the year would both significantly affect the efficiency of parabolic trough solar air heater for the drying of persimmon. Persimmon slices were dried with a high temperature 55oC and high air flow rate (1.97 kg M-1). It was also noted that during the month of November, the PTS air heater efficiency reached the maximum for the drying of persimmon due to the high air mass flow rate. The study as a whole concludes that PTS plays an important role in the drying of different agricultural products including persimmon in this energy crisis world. The study recommends more researches on the design and efficiency of the PTS air heater, which will help the farmers from losses at the field level and also will utilize the perishable commodity of agriculture during the peak season of the crop matures, and thus the farmers’ overall well-being will be increased.

Keywords: Solar Air Heater; Collector Efficiency; Drying Persimmon


Authors: Mavis Nyarko

Abstract: In this study, an effective approach for calculating the size of a gas pipeline is presented. The method is simple and does not need any complicated calculations. The proposed approach uses a simple flow formula to derive the diameter, length, flow rate, inlet and outlet pressures. In general, the method tends to give better results of pipe size prediction. The subject of this paper is to present mathematical relationships, based on which Gas pipe size is calculated.

Keywords: Flow Rate; Gas Flow Equation; Pipe Diameter; Sizing of Pipeline; Gas Pipeline