滚筒复合传热过程烤烟叶丝干燥与收缩特性研究

【目的】研究滚筒复合传热过程烤烟叶丝干燥及收缩特性,为烟叶原料的滚筒干燥工艺优化提供科学参考。【方法】以B2F烤烟上部烟叶为原料,采用滚筒复合传热方式,考察不同筒壁温度下烤烟叶丝的含水率和温度变化特征,以及叶丝颗粒体积收缩特性。【结果】不同筒壁温度下烤烟叶丝的含水率变化均可采用二元Weibull分布模型描述,模型拟合精度在0.9700以上;筒壁温度对恒速干燥脱水阶段和快速升温阶段影响较大,筒壁温度越高,叶丝干燥速率越快,叶丝温度升高也越快;不同筒壁温度下叶丝干燥终点体积收缩率为20%-25%,且收缩率与含水率之间的变化关系近似线性相关。【结论】筒壁温度是影响烤烟叶丝干燥效果的关键因素,应作为烤烟实际干燥加工中的首选调控参数。

Investigation on the drying and shrinkage characteristics of flue-cured cut tobacco during drum processing with combined heat transfer

【Objective】The drying and shrinkage characteristics of cut tobacco during drum drying with combined heat transfer were investigated to provide references for drying process optimization. 【Method】 A kind of B2 F cut tobacco was dried under the different drum temperatures, and the moisture content, temperature and shrinkage of cut tobacco were investigated during drying. 【Result 】Drying kinetics of cut tobacco could be described by the Weibull model, which had a fitting accuracy higher than 0.9700. The drum temperature had a significant effect on the constant drying stage and rapid heating stage of cut tobacco. Higher drum temperature resulted in higher dehydration rate as well as rapider heating rate. The volume shrinkage rate of cut tobacco showed a linear relationship with moisture content. At the drying end, the shrinkage rate of cut tobacco was up to 20%-25%. 【Conclusion】The drum temperature proves to be an key element influencing the drying effects, hence it should be regarded as the first parameter for drying process of cut tobacco.