Abstract

Drying is an important issue for all paddy-producing countries in the world. Paddy drying facts and figures in industrial LSU (Louisiana State University) dryer for the major rice processing areas in Bangladesh were investigated in this research. Performance of selected industrial LSU dryer was assessed in terms of drying characteristics, energy and exergy analysis, and drying efficiency. Quality evaluation in terms of head rice yield (HRY) of the milled product was also analyzed. Analyzed results revealed that 7.0–10.0 h drying time required for reducing parboiled moisture content to 14% (wet basis). Energy analysis indicated that specific electrical and thermal energy varied between 0.34–0.51 and 14.41–28.81 MJ/kg H₂O evaporated, respectively. Average drying efficiency of the dryers in the selected drying complexes ranged between 50.30% and 59.80%. Exergy inflow and exergy losses were found to be reduced during the last 2.0–3.0 h of drying the parboiled paddy while exergy outflow gradually increased throughout the drying period. Exergy efficiency of the dryers varied from 43.63% to 67.21% for parboiled paddy drying. HRY of dried products contrasted between 50% and 54%. Results of the present investigation suggest that there is a positive prospect of enhancing energetic as well as exergetic performance and quality of the dried product.

摘要

干燥是世界上所有稻谷生产国的重要问题。本研究调查了孟加拉主要稻米加工区工业 LSU（路易斯安那州立大学）干燥机的稻谷干燥事实和数据。对所选工业 LSU 干燥机的性能进行了评估，包括干燥特性、能量和火用分析以及干燥效率。还分析了根据碾磨产品的整粒稻产量 (HRY) 的质量评价。分析结果表明，将半熟水分含量降低到 14%（湿基）需要 7.0-10.0 小时的干燥时间。能量分析表明，特定电能和热能在 0.34–0.51 和 14.41–28.81 MJ/kg H _{2之间变化}O分别蒸发。所选干燥综合体中干燥机的平均干燥效率介于 50.30% 和 59.80% 之间。在烘干半熟稻谷的最后 2.0-3.0 小时内，火用流入和火用损失减少，而火用流出在整个烘干期间逐渐增加。烘干机的火用效率从 43.63% 到 67.21% 不等。干燥产品的 HRY 对比在 50% 和 54% 之间。目前的调查结果表明，提高干产品的能量和运动性能和质量具有积极的前景。