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MASS TRANSFER AND HEAT TRANSFER IN CONTINUOUS PLATE DRYER

LIU Xiaolong;JIANG Jialing;LIU Baoqing   

  • Online:2004-07-25 Published:2004-07-25

盘式连续干燥器的传质传热模型

刘小龙;蒋家羚;刘宝庆   

  1. 浙江大学化工机械研究所,浙江 杭州 310027

Abstract: A mathematical model for the heat-mass transfer in a continuous plate dryer was proposed. The calculation of several important parameters, such as height, volume of ringy granule piles on the heating pan and drying time, were made.By using the penetration model of particle heat transfer, exit temperature(Te), humidity of material exit(Xe) of ringy granular piles and average drying rate(m•) were calculated by iterative equations.The only empirical parameter Nmix, called the mixing number, could be predicted by the method, provided that the experimental data with various input humidity(Xi) were known.The model and equations were used for a published experimental plant.The theoretical predictions were in satisfactory agreement with experimental data, and the error between measured data and calculated values was less than 20%.

摘要: 建立了盘式连续干燥器内加热盘面物料的传质模型,给出了干燥器内料环高度、盘面积料量及干燥时间的计算方法.应用颗粒传热理论和扩散理论,导出了每道料环的传热计算公式,由该迭代公式可逐步计算出每道料环的出料温度、出料湿含量及干燥速率.扩散理论中的惟一经验参数——搅拌参数Nmix,在本模型中可由不同进料工况下的多组实验数据加以确定.最后给出了应用该模型进行计算的实例,结果表明,理论计算值与实测值吻合较好,误差一般在20%以内.