TY - JOUR
TI - Performance of solar dryer chamber used for convective drying of sponge-cotton
AU - Aissa Walid
AU - El-sallak Mostafa
AU - Elhakem Ahmed
JN - Thermal Science
PY - 2014
VL - 18
IS - 12
SP - 451
EP - 462
PT - Article
AB - Solar dryer chamber is designed and operated for five days of July 2008.  Drying experiments are conducted for sponge-cotton; as a reference drying  material in the ranges between 35.0 to 49.5°C of ambient air temperature,  35.2 to 69.8 °C drying air temperature, 30 to 1258 W/m2 solar radiation and  0.016 to 0.08 kg/s drying air flow rate. For each experiment, the mass flow  rate of the air remained constant throughout the day. The variation of  moisture ratio, drying rate, overall dryer efficiency, and temperature  distribution along the dryer chamber for various drying air temperatures and  air flow rates are discussed. The results indicated that drying air  temperature is the main factor in controlling the drying process and that  air mass flow rate has remarkable influence on overall drying performance.  For the period of operation, the dryer attained an average temperature of  53.68°C with a standard deviation of 8.49°C within a 12-h period from 7:00 h  to 19:00 h. The results of this study indicated that the present drying  system has overall efficiency between 1.85 and 18.6 % during drying  experiments. Empirical correlations of temperature lapse and moisture ratio  in the dryer chamber are found to satisfactorily describe the drying curves  of sponge-cotton material which may form the basis for the development of  solar dryer design charts.