Performance of solar dryer chamber used for convective drying of sponge-cotton

Abstract

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/m 2 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.

Energy Analysis of a Hybrid Solar Dryer for Drying Coffee Beans

“…The coffee beans' initial moisture content can be evaluated on a wet and dry basis which is stated in percent for every 60 minutes according to the following equations by Aissa, et al (2014) and Yassen et al (2016):…”

“…The drying factor must be determined to achieve the desired water content. Both Aissa et al (2014) and Dong et al (2019) have the same understanding of drying; it is a complex process that involves the transfer of heat and mass between the product and the surrounding media.…”

Design, Fabrication and Testing of Solar Air Dryer

“…Solar drying is one possible solution but its acceptance has been limited partially due to some difficulties. A great deal of experimental work over the last few decades has already shown that agricultural products can be dehydrated using solar energy A.G.M.B.Mustayen, S.Mekhilef, R.Saidur [8] presented a paper on the study on the design, performance, and application of different types of solar dryers. The types examined are the direct, indirect, mixed-mode, active, and passive solar dryers.…”

Computational fluid dynamics analysis for improving temperature distribution in a chili dryer

“…Tzempelikos et al [42] presented an analysis of air velocity distribution in a laboratory batch-type-tray dryer. Other similar types of dryers were proposed in [43,44]. In these studies, CFD has proven to be an important simulation tool for the analysis and improvement of such dryers.…”