Abstract This work describes the thermal behavior and evaluation of kinetics drying of natural rubber sheets using two solar drying technologies: direct and indirect. The solar drying tests were carried out simultaneously in order to compare the behavior under same weather conditions. The moisture content of the rubber sheets was reduced from 45.8 to 0.59 % and from 49.7 to 0.33 % on a dry basis (d.b.) for direct solar drying and indirect solar drying, respectively. The direct drying mode was carried out for 12 days with average temperature and relative humidity inside the greenhouse, during sunny hours, of 37.04 °C and 14.1 %, respectively. Meanwhile, the indirect drying operation was carried out in 9 days (61.62 h intermittently) with 61 °C and 4.77 %, respectively. The average global energy efficiency of the field of SAH was 33.77 %. Thirteen thin layer models were used to evaluate the drying behavior of which the Henderson and Modified Pabis model was the best to describe the solar drying of rubber sheets for the direct and indirect system. As a conclusion, the direct greenhouse-type solar dryer is recommended for small producers and the indirect tunnel-type solar dryer for companies with high and continuous production.

中文翻译：

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两种太阳能热干燥系统下天然橡胶板的干燥动力学

摘要 这项工作描述了使用两种太阳能干燥技术（直接和间接）对天然橡胶板进行动力学干燥的热行为和评价。太阳能干燥测试同时进行，以比较相同天气条件下的行为。对于直接日光干燥和间接日光干燥，橡胶板的水分含量分别从干基 (db) 的 45.8% 减少到 0.59% 和从 49.7% 减少到 0.33%。直接干燥模式进行了 12 天，温室内的平均温度和相对湿度，在晴天，分别为 37.04 °C 和 14.1%。同时，间接干燥操作在 9 天（61.62 h 间断）下进行，温度分别为 61 °C 和 4.77%。SAH领域的全球平均能效为33.77%。使用 13 个薄层模型来评估干燥行为，其中 Henderson 和 Modified Pabis 模型最适合描述直接和间接系统橡胶板的太阳能干燥。综上所述，直接温室型太阳能干燥机推荐用于小型生产商，间接隧道式太阳能干燥机推荐用于高产量和连续生产的公司。