摘要
分析了脉动流化床中气—固传热特性及干燥特性.研究表明脉动流化床中物料的运动状态,可以看作是其平动、振动和旋转运动的叠加.在一定的气流速度下,处于旋转运动物料的传热效果要比振动物料的传热效果好.将Ranz-Marshall公式应用到在脉动流化床气—固传热系数的计算中,有其局限性.气流温度是影响干燥过程降水幅度的重要参数,床层静止高度及脉动频率对干燥过程的影响很小.当气流速度等于或高于最小脉动流化速度时,床层内的温度分布均匀一致,脉动频率对温度分布的影响很小.
The heat tansfer and drying characteristics between gas and solid gas in pulsed-fluidized bed were studied.The results show that motion states of particles in pulsed-fluidized bed were composed of movement,vibration and rotation. Effect of rotational motion of particle on heat transfer is greater than that of the vibration under certain rate of airflow. The equation of Ranz-Marshall have some disadvantages when it is used to compute the heat transfer coefficient between gas and solid in pulsed-fluidized bed.The air temperature is the most important parameter in the relationship of current humidity vs drying time. Static bed height as well as pulsation frequency has some influence on the drying process.The temperature distribution in the bed is uniform when the airflow rate is geater than the minimum pulsed-fluidized rate, and pulsation frequency has little influence on the temperature distribution in the bed.
出处
《山东理工大学学报（自然科学版）》
CAS
2005年第3期5-9,共5页
Journal of Shandong University of Technology:Natural Science Edition
基金
山东省优秀中青年科学家科研奖励基金资助项目
关键词
脉动流化床
传热
干燥
<Keyword>pulsed-fluidized bed
heat tansfer
drying
