摘要
气流干燥器在工农业生产中有广泛的应用。目前,有关气流干燥器设计的方法有多种。本文在夏诚意法的基础上,利用气-固两相流动及传热的理论,建立了直管型气流干燥管设计的通用数学模型。模型针对干燥过程中物料恒速干燥与气力输送过程中颗粒加速运动之间的不同关系,将气流干燥过程分为四段:颗粒第一加速段(预热段)、颗粒第二加速段、颗粒第三运动段(分两种情况讨论)以及颗粒匀速段。模型综合考虑气固相对雷诺数Rer在过渡区、湍流区的情况,对一般气流干燥过程具有一定的普适性。利用本文数学模型编程设计,计算结果与实际吻合较好。
Pneumatic dryer is widely applied in industrial and agricultural production.At present,there are several efficient methods of designing a pneumatic dryer.On the basis of Xia Chen yi＇s method,we built a universal mathematical model to design a straight pipe dryer according to gas-solid two-phase flow and heat transfer theory.Based on the differences between moisture content of material during constant drying rate and acceleration of particles,the model divided the pneumatic drying process into four sections,named as the first accelerating section of particles（the preheating section）,the second accelerating section of particles,the third movement section of particles（two cases discussed） and the uniform motion of particles.In addition,the model took the relative reynolds number of gas-solid two-phase in both transition flow and turbulent flow into consideration,mading itself universal to a general pneumatic drying.Programming calculation based on this model,the results were coincided well with practical.
关键词
气流干燥器
分段设计
通用模型
设计计算
pneumatic dryer
segmentation design
universal model
design calculation
