无抄板间热式滚筒干燥机传热研究

Modeling of heat transfer in indirect rotary dryer that without flights

对流传热系数α是间接加热式滚筒干燥机设计中的重要参数。通过因次分析建立了无抄板间热式滚筒干燥机对流传热系数α与干燥机操作条件间关系的模型,并进一步分析了模型中各个影响因素对对流传热系数α影响。结果表明:无抄板间接加热式滚筒干燥机的对流传热系数α随干燥机内物料流动速度(D.n)、湿分组成x1、物料振实密度ρbt和有效黏度η的增大而增大,随干燥机特征尺寸δ和物料比热λ的增大而减小。

The convective heat-transfer coefficient α is one of the important parameters in the design of an indirect rotary dryer.A model that correlates α with several process parameters for an indirect rotary dryer without flights has been developed through dimensional analysis.According to the model,α increases with the product of the drum diameter D and rotation speed n,the moisture content x1,the tap density of the mixture ρbt and the virtual viscosity η;α decreases with the qualitative length of the dryer δ and the specific heat of the mixture λ.