Abstract

Following the successful drying experiments conducted with a domestic microwave oven, this study presents the results of laboratory scale drying of clay tiles. The drying process was realized as a combination of convective drying with microwave heating. In detail, the dependence of drying time and total energy consumption on process conditions were investigated. For this analysis, the microwave power was either intermittently supplied or continuously increased with a ramp profile during the microwave heating periods. Additionally, the impact of the drying air temperature was investigated. The scale-up from the basic experiments to the lab scale plant was realized by successive increase of the sample size. Process control was based on temperature measurement of the drying sample. The results suggest intermittent microwave heating as an alternative option for fast and sound drying of clay roof tiles. Increase of air temperature instead had a minor impact on drying indices. In comparison with continuous heating, the major advantages of intermittent heat supply are its energy efficiency and the better options for process control.

摘要

在使用家用微波炉成功进行干燥实验之后，本研究展示了粘土砖的实验室规模干燥结果。干燥过程实现为对流干燥与微波加热的组合。详细地，研究了干燥时间和总能耗对工艺条件的依赖性。对于该分析，在微波加热期间，微波功率要么间歇供应，要么以斜坡曲线连续增加。此外，还研究了干燥空气温度的影响。通过不断增加样本量，实现了从基础实验到实验室规模工厂的放大。过程控制基于干燥样品的温度测量。结果表明，间歇性微波加热可以作为粘土屋面瓦快速、可靠干燥的替代选择。相反，气温升高对干燥指数的影响较小。与连续加热相比，间歇供热的主要优势在于其能源效率和更好的过程控制选择。