Some engineering factors affecting the performance of in-bin drying system for soybean grain [electronic resource].

Includes references.

The aim of this study was to investigate some engineering factors affecting the performance of in-bin drying systems for high-moisture grain. An ambient-air and solar heated-air drying systems with two airflow rates are used for drying soybean grain during 2002-harvest season. The change of grain moisture content and their effect on some physical properties of soybean grain and the static pressure drop during drying process was determined Also, the effect of drying system, airflow rate and bin depth on the change of soybean moisture content, 'drying rate and energy consumption as well as final quality of dried grain were evaluated The results showed that the solar collector increased the air temperature by 7.2oC and decreased the air relative humidity by 22% inside the greenhouse compared with ambient-air during drying process. The results also indicated that, linear dimensions and thousand grain mass of soybean are linearly related to its moisture content and increased with increasing moisture content within the range 11.9 to 29.2% (d b.). While, bulk density, particle density and porosity of soybean decreased with the increase in grain moisture content. Also; increasing airflow from 1.2 to 2.4 m3/min.t tends to decrease drying time by 33.33% and increasing energy consumption from 19.62 to 30.92MJlt with ambient-air drying while. with solar heated-air drying, the drying time decrease by 28.57% and energy consumption increased from 12.49 to 21.4 M/lt. Moreover, the electrical energy consumption of the fan increased with natural-air drying due to the extension of drying time. Furthermore, decreasing soybean grain moisture content by 1% during drying process tends to increase the static pressure drop by 3.34%. On the other hand. using natural-air drying system with 2.4 m3/min. t was found nearly equivalent solar heated-air drying and gave the best quality of dried grain. While. using solar heated-air drying speeded up drying rate but increase energy required for drying and caused further over-drying of dried grain.

Summary in Arabic.

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