复合传热对薄层烟丝干燥强化传质作用的动力学分析  

Dynamics Analysis of Multiple Heat Transfer Impacts on Intensive Mass Transfer During Thin Layer Drying Processing of Cut Tobacco

作　　者：刘泽[1] 李斌[1] 于川芳[1] 

机构地区：[1]郑州烟草研究院烟草行业烟草工艺重点实验室

出　　处：《烟草科技》2009年第11期5-10,共6页Tobacco Science & Technology

基　　金：郑州烟草研究院科技项目"烟丝滚筒热湿处理质量变化特征基础研究"(2008CZ0320)

摘　　要：为研究复合传热过程对烟丝干燥的影响规律，选择了3种烟丝作为试验原料，利用固定床式薄层干燥装置，在风速一定的条件下，考察了热风温度（60～100oC）、薄板温度（50～90℃）对复合传热干燥过程的影响；采用菲克第二定律和有效扩散系数与热风温度的关系（Arrhenius公式），确定了恩施、宜宾和巴西3种烟丝的表观活化能为8．31、12．11、21．13kJ／mol；采用无因次分析的方法对烟丝有慈扩散系数与薄板温度关系进行建模分析，无因次关系中的指数项物理意义上可以解释为强化因子，反映了薄板温度对不同烟丝干燥过程的强化传质作用，薄板温度强化因子依次为10．08、12．21、10．82；试验结果表明：所建模型能够表征传导传热对烟丝干燥动力学参数的影响规律。In order to find out the influences of multiple heat transfer process on cut tobacco drying, the effects of hot air temperature （60 - 100℃ ） and thin plate temperature （50 -90℃ ） on the drying kinetics of three kinds of cut tobacco were investigated in a fixed bed at constant air velocity. The apparent activation energies （Ea ） of tobacco shreds from Enshi tobacco, Yibin tobacco and Brazil tobacco were obtained by Fick＇ s second law and Arrhenius formula. They were 8.31 kJ/mol, 12.11 kJ/mol and 21.13 kJ/mol, respectively. The model of the relationship between effective diffusion coefficient of tobacco shreds and thin plate temperature was established with dimensionless analysis method, and the exponential terms in the dimensionless relation might be explained physically as intensified factors of thin plate temperature, which reflected the intensified effect of thin plate temperature on mass transfer to tobacco shreds, and the intensified factors for the three tobacco shreds were： Enshi, 10.08; Yibin, 12.21; Brazil, 10.82. The results showed that the established model can characterize the effect of conductive heat transfer on drying kinetic parameters of tobacco shreds.

关 键 词：烟丝 薄层干燥 复合传热 强化传质 干燥动力学 

分 类 号：TS412[农业科学—烟草工业]